Differential Response of Delta13C and Water Use Efficiency to Arbuscular Mycorrhizal Infection in Two Aridland Woody Plant Species

Oecologia. May, 2003  |  Pubmed ID: 16228249

During a revegetation field experiment in Southeast Spain, we measured foliar carbon isotope ratios (delta13C) and gas exchange parameters in order to evaluate the influence of arbuscular mycorrhizal (AM) infection on the water use efficiency (WUE) of two semiarid woodland species. WUE during drought was significantly enhanced by inoculation with Glomus intraradices in Olea europaea ssp sylvestris, but not in Rhamnus lycioides. While Olea is a long-lived, slow-growing evergreen tree with a conservative water use strategy, Rhamnus is a drought-deciduous shrub with a shorter lifespan; these differences may explain their dissimilar patterns of physiological response to inoculation with the same AM fungus. Differences in delta13C and WUE between Olea and Rhamnus were larger when comparing AM inoculated than non-inoculated seedlings. This result suggests that some of the interspecific variability in delta13C observed for aridland plant communities may be due to different physiological responses to mycorrhization.

Spin Dynamics for the Lebwohl-Lasher Model

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Sep, 2005  |  Pubmed ID: 16241610

A spin dynamics algorithm, combining checkerboard updating and a rotation algorithm based on the local second-rank ordering field, is developed for the Lebwohl-Lasher model of liquid crystals. The method is shown to conserve energy well and to generate simulation averages that are consistent with those obtained by Monte Carlo simulation. However, care must be taken to avoid the undesirable effects of director rotation, and a method for doing this is proposed.

Best Clinical Practice with Ziprasidone IM: Update After 2 Years of Experience

CNS Spectrums. Sep, 2005  |  Pubmed ID: 16247923

Acute agitation is a common psychiatric emergency often treated with intramuscular (i.m.) medication when rapid control is necessary or the patient refuses to take an oral agent. Conventional i.m. antipsychotics are associated with side effects, particularly movement disorders, that may alarm patients and render them unreceptive to taking these medications again. Ziprasidone (Geodon) is the first second-generation, or atypical, antipsychotic to become available in an i.m. formulation. Ziprasidone IM was approved by the Food and Drug Administration in 2002 for the treatment of agitation in patients with schizophrenia. In October 2004, a roundtable panel of physicians with extensive experience in the management of acutely agitated patients met to review the first 2 years of experience with this agent. This monograph, a product of that meeting, discusses clinical experience to date with ziprasidone IM and offers recommendations on its use in various settings. In clinical trials, patients treated with ziprasidone IM demonstrated significant and rapid (within 15-30 minutes) reduction in agitation and improvement in psychotic symptoms, agitation, and hostility to an extent greater than or equal to that attained with haloperidol i.m. Tolerability of ziprasidone IM was superior to that of haloperidol IM, with a lower burden of movement disorders. Clinical trials have also shown that ziprasidone IM can be administered with benzodiazepines without adverse consequences. Transition from i.m. to oral ziprasidone has been well tolerated, with maintenance of symptom control. The most common adverse events associated with ziprasidone IM were insomnia, headache, and dizziness in fixed-dose trials and insomnia and hypertension in flexible-dose trials. No consistent pattern of escalating incidence of adverse events with escalating ziprasidone doses has been observed. Changes in QTc interval associated with ziprasidone at peak serum concentrations are modest and comparable to those seen with haloperidol IM. Results of randomized clinical trials of ziprasidone IM have been corroborated in studies in real-world treatment settings involving patients with extreme agitation or a recent history of alcohol or substance abuse. In these circumstances, clinically significant improvement was seen within 30 minutes of ziprasidone IM administration, without regard to the suspected underlying etiology of agitation. Agents with a good safety/tolerability profile, such as ziprasidone IM, may be more cost effective long term than older agents, due to reduced incidence of acute adverse effects (eg, acute dystonia) that often require extended periods of observation. Additional trials of ziprasidone IM in agitated patients in a variety of clinical setting are warranted to generate comparative risk/benefit data with conventional agents and other second-generation antipsychotics.

2,5-diketopiperazines As Potent, Selective, and Orally Bioavailable Oxytocin Antagonists. 2. Synthesis, Chirality, and Pharmacokinetics

Journal of Medicinal Chemistry. Nov, 2005  |  Pubmed ID: 16250654

A short stereoselective synthesis of a series of chiral 7-aryl-2,5-diketopiperazines oxytocin antagonists is described. Varying the functionality and substitution pattern of substituents in the 7-aryl ring and varying the chirality of this exocyclic ring have produced potent oxytocin antagonists (pK(i) > 8.5). SAR and pharmacokinetic profiling of this series of (3R,6R,7R)-2,5-diketopiperazines together with the introduction of an ortho F group in the 7-aryl ring to improve rat pK has culminated in the 2',4'-difluorophenyldiketopiperazine derivative 37, a highly potent oxytocin antagonist against the human oxytocin receptor (pK(i) = 8.9) that has >1000-fold selectivity over all three vasopressin receptors V1a, V2, and V1b. It has good bioavailability (46%) in the rat and moderate bioavailability (13-31%) in the dog and is more active in vivo in the rat than atosiban (rat DR(10) = 0.44 mg/kg iv).

The Expert Consensus Guideline Series. Treatment of Behavioral Emergencies 2005

Journal of Psychiatric Practice. Nov, 2005  |  Pubmed ID: 16319571

Due to inherent dangers and barriers to research in emergency settings, few data are available to guide clinicians about how best to manage behavioral emergencies. Key constructs such as agitation are poorly defined. This lack of empirical data led us to undertake a survey of expert opinion, results of which were published in the 2001 Expert Consensus Guidelines on the Treatment of Behavioral Emergencies. Several second-generation (atypical) antipsychotics (SGAs) are now available in new formulations for treating behavioral emergencies (e.g., intramuscular [i.m.] olanzapine and ziprasidone; rapidly dissolving tablets of olanzapine and risperidone). Critical questions face the field. The SGAs are significantly different from the FGAs and from each other and have not been studied in unselected patients as were the FGAs. Can the SGAs can be thought of as a class, do all antipsychotics have similar anti-agitation effects in different conditions, and, if equally effective, what limits might their safety profiles impose? Should antipsychotics be used more specifically to treat psychotic conditions, while benzodiazepines (BNZs) alone are used nonspecifically? Few data are available concerning combinations of SGAs and BNZs, and findings concerning the traditional combination of haloperidol plus a BNZ may not be relevant to combinations with SGAs. The culture is also evolving with more emphasis on patient involvement in treatment decisions. An international consensus has been developing that calming rather than sedation is the appropriate endpoint of behavioral emergency interventions. We undertook a new survey of expert opinion to update recommendations from the earlier survey.

Serotonin Gene Polymorphisms and Bipolar I Disorder: Focus on the Serotonin Transporter

Annals of Medicine. 2005  |  Pubmed ID: 16338761

The pathogenesis of bipolar disorder may involve, at least in part, aberrations in serotonergic neurotransmission. Hence, serotonergic genes are attractive targets for association studies of bipolar disorder. We have reviewed the literature in this field. It is difficult to synthesize results as only one polymorphism per gene was typically investigated in relatively small samples. Nevertheless, suggestive associations are available for the 5HT2A receptor and the serotonin transporter genes. With the availability of extensive polymorphism data and high throughput genotyping techniques, comprehensive evaluation of these genes using adequately powered samples is warranted. We also report on our investigations of the serotonin transporter, SLC6A4 (17q11.1-q12). An insertion/deletion polymorphism (5HTTLPR) in the promoter region of this gene has been investigated intensively. However, the results have been inconsistent. We reasoned that other polymorphism/s may contribute to the associations and the inconsistencies may be due to variations in linkage disequilibrium (LD) patterns between samples. Therefore, we conducted LD analyses, as well as association and linkage using 12 polymorphisms, including 5HTTLPR. We evaluated two samples. The first sample consisted of 135 US Caucasian nuclear families having a proband with bipolar I disorder (BDI, DSM IV criteria) and available parents. For case-control analyses, the patients from these families were compared with cord blood samples from local Caucasian live births (n = 182). Our second, independent sample was recruited through the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD, 545 cases, 548 controls). No significant associations were detected at the individual polymorphism or haplotype level using the case-control or family-based analyses. Our analyses do not support association between SLC6A4 and BDI families. Further studies using sub-groups of BDI are worthwhile.

Suicidal Ideation and Pharmacotherapy Among STEP-BD Patients

Psychiatric Services (Washington, D.C.). Dec, 2005  |  Pubmed ID: 16339615

Little is known about the effects of lithium on suicidal ideation or about the possible antisuicidal effects of divalproex, second-generation antipsychotics, or antidepressants among persons with bipolar disorder.

Prevalence and Correlates of Tobacco Use in Bipolar Disorder: Data from the First 2000 Participants in the Systematic Treatment Enhancement Program

General Hospital Psychiatry. Sep-Oct, 2005  |  Pubmed ID: 16168792

Only a few small descriptive studies have examined the prevalence and correlates of tobacco use among bipolar patients. We predicted that poorly controlled manic, depressed and mixed states, and the presence of psychotic symptoms, would be associated with a greater prevalence of smoking among patients with bipolar disorder.

Molecular Characterization of Autoinduction of Bioluminescence in the Microtox Indicator Strain Vibrio Fischeri ATCC 49387

Canadian Journal of Microbiology. Jul, 2005  |  Pubmed ID: 16175203

Repeated attempts to clone the luxI from Vibrio fischeri ATCC 49387 failed to produce a clone carrying a functional LuxI. Sequence data from the clones revealed the presence of a polymorphism when compared with previously published luxI sequences, prompting further characterization of bioluminescence regulation in V. fischeri ATCC 49387. Further investigation of V. fischeri ATCC 49387 revealed that its LuxI protein lacks detectable LuxI activity due to the presence of a glutamine residue at position 125 in the deduced amino acid sequence. Specific bioluminescence in V. fischeri ATCC 49387 increases with increasing cell density, indicative of a typical autoinduction response. However, conditioned medium from this strain does not induce bioluminescence in an ATCC 49387 luxR-plux-based acyl homoserine lactone reporter strain, but does induce bioluminescence in ATCC 49387. It has been previously shown that a V. fischeri MJ-1 luxI mutant exhibits autoinduction of bioluminescence through N-octanoyl-L-homoserine lactone, the product of the AinS autoinducer synthase. However, a bioreporter based on luxR-plux from V. fischeri ATCC 49387 responded poorly to conditioned medium from V. fischeri ATCC 49387 and also responded poorly to authentic N-octanoyl-DL-homoserine lactone. A similar MJ-1-based bioreporter showed significant induction under the same conditions. A putative ainS gene cloned from ATCC 49387, unlike luxI from ATCC 49387, expresses V. fischeri autoinducer synthase activity in Escherichia coli. This study suggests that a regulatory mechanism independent of LuxR and LuxI but possibly involving AinS is responsible for the control of autoinduction of bioluminescence in V. fischeri ATCC 49387.

Epidermolysis Bullosa in Cattle in the UK

The Veterinary Record. Oct, 2005  |  Pubmed ID: 16215257

Coxibs and Cardiovascular Risk

CMAJ : Canadian Medical Association Journal = Journal De L'Association Medicale Canadienne. Oct, 2005  |  Pubmed ID: 16217098

Complete Genome Sequence and Lytic Phase Transcription Profile of a Coccolithovirus

Science (New York, N.Y.). Aug, 2005  |  Pubmed ID: 16099989

The genus Coccolithovirus is a recently discovered group of viruses that infect the globally important marine calcifying microalga Emiliania huxleyi. Among the 472 predicted genes of the 407,339-base pair genome are a variety of unexpected genes, most notably those involved in biosynthesis of ceramide, a sphingolipid known to induce apoptosis. Uniquely for algal viruses, it also contains six RNA polymerase subunits and a novel promoter, suggesting this virus encodes its own transcription machinery. Microarray transcriptomic analysis reveals that 65% of the predicted virus-encoded genes are expressed during lytic infection of E. huxleyi.

Phlorizin Administration Increases Hepatic Gluconeogenic Enzyme MRNA Abundance but Not Feed Intake in Late-lactation Dairy Cows

The Journal of Nutrition. Sep, 2005  |  Pubmed ID: 16140899

Gluconeogenic capacity may be an important factor regulating dry matter intake (DMI) in lactating dairy cows. To determine whether increased glucose demand affects feed intake and hepatic gene expression, lactating Holstein cows were treated with phlorizin or vehicle (propylene glycol) for 7 d. Multiparous cows (n = 12; 269 +/- 65 d in milk, mean +/- SD) were randomly assigned to treatment sequence in a crossover design and were adapted to a common diet for 7 d before the beginning of the experiment. Phlorizin injected s.c. at 4 g/d caused glucose excretion in urine at the rate of 474 g/d. Although phlorizin decreased lactose synthesis and milk production (both P < 0.01), DMI and 3.5% fat-corrected milk production were not altered by treatment. A net deficit of 383 g glucose/d in milk and urine for phlorizin (relative to control) was likely replaced partially through increased gluconeogenesis. The molar insulin:glucagon ratio was decreased 17% by phlorizin (P < 0.001) and hepatic phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and pyruvate carboxylase mRNA abundance increased (all P < 0.05). Late-lactation dairy cows adapted quickly to an increase in peripheral glucose demand; adaptation mechanisms likely included enhanced gluconeogenic capacity, whereas DMI was not altered.

Hyperbaric Oxygen in the Treatment of Patients with Cerebral Stroke, Brain Trauma, and Neurologic Disease

Advances in Therapy. Nov-Dec, 2005  |  Pubmed ID: 16510383

Hyperbaric oxygen (HBO) therapy has been used to treat patients with numerous disorders, including stroke. This treatment has been shown to decrease cerebral edema, normalize water content in the brain, decrease the severity of brain infarction, and maintain blood-brain barrier integrity. In addition, HBO therapy attenuates motor deficits, decreases the risks of sequelae, and prevents recurrent cerebral circulatory disorders, thereby leading to improved outcomes and survival. Hyperbaric oxygen also accelerates the regression of atherosclerotic lesions, promotes antioxidant defenses, and suppresses the proliferation of macrophages and foam cells in atherosclerotic lesions. Although no medical treatment is available for patients with cerebral palsy, in some studies, HBO therapy has improved the function of damaged cells, attenuated the effects of hypoxia on the neonatal brain, enhanced gross motor function and fine motor control, and alleviated spasticity. In the treatment of patients with migraine, HBO therapy has been shown to reduce intracranial pressure significantly and abort acute attacks of migraine, reduce migraine headache pain, and prevent cluster headache. In studies that investigated the effects of HBO therapy on the damaged brain, the treatment was found to inhibit neuronal death, arrest the progression of radiation-induced neurologic necrosis, improve blood flow in regions affected by chronic neurologic disease as well as aerobic metabolism in brain injury, and accelerate the resolution of clinical symptoms. Hyperbaric oxygen has also been reported to accelerate neurologic recovery after spinal cord injury by ameliorating mitochondrial dysfunction in the motor cortex and spinal cord, arresting the spread of hemorrhage, reversing hypoxia, and reducing edema. HBO has enhanced wound healing in patients with chronic osteomyelitis. The results of HBO therapy in the treatment of patients with stroke, atherosclerosis, cerebral palsy, intracranial pressure, headache, and brain and spinal cord injury are promising and warrant further investigation.

Contributors to Suicidal Ideation Among Bipolar Patients with and Without a History of Suicide Attempts

Suicide & Life-threatening Behavior. Dec, 2005  |  Pubmed ID: 16552982

This study was designed to develop models for vulnerability to suicidal ideation in bipolar patients. Logistic regression models examined correlates of suicidal ideation in patients who had versus had not attempted suicide previously. Of 477 patients assessed, complete data on demographic, illness history, and personality variables were available on 243. The regression models achieved positive predictive values of 55% and 59% for the attempter (N = 92) and nonattempter groups (N = 151), respectively. Depression was cross-sectionally associated with suicidal ideation in both the attempter and nonattempter groups but made a smaller contribution among attempters. Poor psychosocial adaptation and the personality factor "openness" were stronger contributors to suicidal ideation among prior attempters while anxiety and extraversion appeared protective against ideation. Among nonattempters, depression, anxiety, and neuroticism were the predominant influences on suicidal ideation. Bipolar patients with suicidal ideation may benefit from different treatment strategies depending on their prior attempt status.

Terri's Law and Democracy

Stetson Law Review. 2005  |  Pubmed ID: 17099999

Reading Dynamic Kinase Activity in Living Cells for High-throughput Screening

ACS Chemical Biology. Jul, 2006  |  Pubmed ID: 17163774

Protein kinases, as crucial signaling molecules, represent an emerging class of drug targets, and the ability to assay their activities in living cells with high-throughput screening should provide exciting opportunities for drug discovery and chemical and functional genomics. Here, we describe a general method for high-throughput reading of dynamic kinase activities using ratiometric fluorescent sensors, and showcase an example of reading intracellular activities of protein kinase A (PKA) and the cyclic adenosine monophosphate (cAMP)/PKA pathway downstream of many G-protein coupled receptors (GPCRs). We further demonstrate the first compound screen based on the ability of compounds to modulate dynamic kinase activities in living cells and show that such screening of a collection of clinical compounds has successfully identified modulators of the GPCR/cAMP/PKA pathway.

Structure of a Liquid Crystalline Fluid Around a Macroparticle: Density Functional Theory

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Aug, 2006  |  Pubmed ID: 17025446

The structure of a molecular liquid, in both the nematic liquid crystalline and isotropic phases, around a cylindrical macroparticle, is studied using density functional theory. In the nematic phase the structure of the fluid is highly anisotropic with respect to the director, in agreement with results from simulation and phenomenological theories. On going into the isotropic phase the structure becomes rotationally invariant around the macroparticle with an oriented layer at the surface.

The Coccolithovirus Microarray: an Array of Uses

Briefings in Functional Genomics & Proteomics. Dec, 2006  |  Pubmed ID: 17035357

The Coccolithoviridae is a recently discovered family of giant algal viruses. Here, we review the genomic and transcriptomic characterization of this family based on the results generated from a coccolithovirus microarray. The microarray has been used to aid the annotation of the genome, to investigate the infection process at the transcriptional level and to assess the diversity in genomic content within the family.

Prospective Predictors of Suicide and Suicide Attempts in 1,556 Patients with Bipolar Disorders Followed for Up to 2 Years

Bipolar Disorders. Oct, 2006  |  Pubmed ID: 17042830

Bipolar disorders are associated with high rates of suicide attempts (SAs) and completions. Several factors have been reported to be associated with suicide in persons with bipolar disorder, but most studies to date have been retrospective and have not utilized multivariate statistics to account for the redundant prediction among variables submitted for analysis.

Influences of Hyperbaric Oxygen on Blood Pressure, Heart Rate and Blood Glucose Levels in Patients with Diabetes Mellitus and Hypertension

Archives of Medical Research. Nov, 2006  |  Pubmed ID: 17045116

We investigated the influences of hyperbaric oxygen (HBO(2)) on systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and blood glucose level (BGL).

Spiral Wave Dynamics Under Feedback Via an Equilateral Triangular Sensory Domain

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Dec, 2006  |  Pubmed ID: 17280141

We perform a numerical study of the trajectories of spiral wave cores in excitable systems whose excitability is modulated in proportion to the integral of the activity in a sensory domain in the shape of an equilateral triangle. As a result of this domain shape having vertices opposite sides, unusual forms of lobed limit cycles occur, which are destroyed and then re-form as the domain size is varied. Some key results are also demonstrated experimentally using the light-sensitive Belousov-Zhabotinsky reaction. To characterize the observed behavior, we introduce the concept of express and stagnation zones, which are regions where the trajectory moves particularly rapidly or slowly. The location and strength of the zones far from the domain are accounted for by approximating the parts of the spiral wave crossing the domain by a series of plane waves.

Genome Comparison of Two Coccolithoviruses

Virology Journal. 2006  |  Pubmed ID: 16553948

The Coccolithoviridae is a recently discovered family of viruses that infect the marine coccolithophorid Emiliania huxleyi. Following on from the sequencing of the type strain EhV-86, we have sequenced a second strain, EhV-163.

Statins in Primary Prevention: Uncertainty in Women, Elderly

American Family Physician. Mar, 2006  |  Pubmed ID: 16570733

Validity of the Distinction Between Primary and Secondary Substance Use Disorder in Patients with Bipolar Disorder: Data from the First 1000 STEP-BD Participants

The American Journal on Addictions / American Academy of Psychiatrists in Alcoholism and Addictions. Mar-Apr, 2006  |  Pubmed ID: 16595351

The validity of a primary/secondary substance use disorder (SUD) distinction was evaluated in the first 1000 patients enrolled in the Systematic Treatment Enhancement Program for Bipolar Disorder. Patients with primary SUD (n = 116) were compared with those with secondary SUD (n = 275) on clinical course variables. Patients with secondary SUD had fewer days of euthymia, more episodes of mania and depression, and a greater history of suicide attempts. These findings were fully explained by variations in age of onset of bipolar disorder. The order of onset of SUDs was not linked to bipolar outcomes when age of onset of bipolar disorder was statistically controlled. The primary/secondary distinction for SUD is not valid when variations in the age of onset of the non-SUD are linked to course characteristics.

Differing Effects of Antipsychotic Medications on Substance Abuse Treatment Patients with Co-occurring Psychotic and Substance Abuse Disorders

The American Journal on Addictions / American Academy of Psychiatrists in Alcoholism and Addictions. Mar-Apr, 2006  |  Pubmed ID: 16595355

This retrospective study of patients treated in a ninety-day, inpatient, dual-diagnosis treatment program examined antipsychotic effectiveness in this population using length of stay in treatment and successful program completion as outcome measures. All patients with co-occurring substance dependence and schizophrenia or schizoaffective disorder treated with olanzapine, risperidone, ziprasidone, and typical depot neuroleptics from January 2001 to December 2003 (N = 55) are the subjects of this study. Patients stayed longer in treatment when taking risperidone (82 +/- 19 days) or ziprasidone (74 +/- 21 days) compared with olanzapine (44 +/- 30 days) or typicals (47 +/- 36 days). Eighty-eight percent of risperidone patients and 64% of ziprasidone patients successfully completed the program, while only 33% of olanzapine patients and 40% of patients on typicals successfully completed the program. Risperidone and ziprasidone were associated with significantly better program performance than olanzapine or depot typicals in this population. Possible reasons for this difference are discussed.

Oxytocin Antagonists As Potential Therapeutic Agents for the Treatment of Preterm Labour

Progress in Medicinal Chemistry. 2006  |  Pubmed ID: 16697900

Effects of Gender on Peak Oxygen Consumption and the Timing of Cardiac Transplantation

Journal of the American College of Cardiology. Jun, 2006  |  Pubmed ID: 16750689

This study examines the gender effects on peak exercise oxygen consumption (VO2) and survival in heart failure (HF) patients and their implications for cardiac transplantation.

Between a Rock and a Hard Place: Trace Element Nutrition in Chlamydomonas

Biochimica Et Biophysica Acta. Jul, 2006  |  Pubmed ID: 16766055

Photosynthetic organisms are among the earliest life forms on earth and their biochemistry is strictly dependent on a wide range of inorganic nutrients owing to the use of metal cofactor-dependent enzymes in photosynthesis, respiration, inorganic nitrogen and sulfur assimilation. Chlamydomonas reinhardtii is a photosynthetic eukaryotic model organism for the study of trace metal homeostasis. Chlamydomonas spp. are widely distributed and can be found in soil, glaciers, acid mines and sewage ponds, suggesting that the genus has significant capacity for acclimation to micronutrient availability. Analysis of the draft genome indicates that metal homeostasis mechanisms in Chlamydomonas represent a blend of mechanisms operating in animals, plants and microbes. A combination of classical genetics, differential expression and genomic analysis has led to the identification of homologues of components known to operate in fungi and animals (e.g., Fox1, Ftr1, Fre1, Fer1, Ctr1/2) as well as novel molecules involved in copper and iron nutrition (Crr1, Fea1/2). Besides activating iron assimilation pathways, iron-deficient Chlamydomonas cells re-adjust metabolism by reducing light delivery to photosystem I (to avoid photo-oxidative damage resulting from compromised FeS clusters) and by modifying the ferredoxin profile (perhaps to accommodate preferential allocation of reducing equivalents). Up-regulation of a MnSOD isoform may compensate for loss of FeSOD. Ferritin could function to buffer the iron released from programmed degradation of iron-containing enzymes in the chloroplast. Some metabolic adjustments are made in anticipation of deficiency while others occur only with sustained or severe deficiency. Copper-deficient Chlamydomonas cells induce a copper assimilation pathway consisting of a cell surface reductase and a Cu(+) transporter (presumed CTR homologue). There are metabolic adaptations in addition: the synthesis of "back-up" enzymes for plastocyanin in photosynthesis and the ferroxidase in iron assimilation plus activation of alternative oxidase to handle the electron "overflow" resulting from reduced cytochrome oxidase function. Oxygen-dependent enzymes in the tetrapyrrole pathway (coproporphyrinogen oxidase and aerobic oxidative cyclase) are also increased in expression and activity by as much as 10-fold but the connection between copper nutrition and tetrapyrroles is not understood. The copper-deficiency responses are mediated by copper response elements that are defined by a GTAC core sequence and a novel metalloregulator, Crr1, which uses a zinc-dependent SBP domain to bind to the CuRE. The Chlamydomonas model is ideal for future investigation of nutritional manganese deficiency and selenoenzyme function. It is also suited for studies of trace nutrient interactions, nutrition-dependent metabolic changes, the relationship between photo-oxidative stress and metal homeostasis, and the important questions of differential allocation of limiting metal nutrients (e.g., to respiration vs. photosynthesis).

Propionate Challenge Tests Have Limited Value for Investigating Bovine Metabolism

The Journal of Nutrition. Jul, 2006  |  Pubmed ID: 16772459

Two experiments were designed to assess the potential utility of the propionate challenge test (PCT) as an index of gluconeogenic capacity. In Expt. 1, the dose-response to jugular propionate infusion was assessed in a duplicated 4 x 4 Latin square experiment with 8 lactating dairy cows. Sodium propionate (4.5 mol/L, pH 7.4) was infused in an intrajugular bolus at 0 (saline), 0.52, 1.04, or 1.56 mmol/kg body weight (BW), and jugular blood was sampled over the following 2 h. Peak propionate concentration in plasma and area under the curve for plasma glucose both increased linearly with increasing propionate dose (P < 0.01). Plasma free fatty acid (FFA) concentration was elevated by all propionate treatments at 20 min postinfusion (P = 0.03), and plasma cortisol concentration tended to increase (P < 0.10) after propionate infusions. Experiment 2 was designed to study the effect of short-term differences in fed state on responses to propionate infusion. Lactating dairy cows (n = 8) were included in a duplicated 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Sodium propionate (1.04 mmol/kg BW) or saline was infused either before feeding (0900) or 2 h after feeding (1300). Fed cows consumed 4.4 +/- 1.4 kg dry matter before the PCT. Although fed cows had a significantly higher preinfusion plasma propionate concentration, fed state did not influence postinfusion changes in plasma propionate, glucose, insulin, glucagon, or FFA concentrations. Liver glycogen concentration decreased significantly after propionate, but not saline infusion (P < 0.05). Short-term differences in fed state do not affect the physiological responses to PCT. However, glucagon release after jugular administration of propionate is likely supraphysiologic, and postinfusion lipolysis and glycogenolysis suggest that stress responses may alter PCT measurements. Although the PCT may help to diagnose liver dysfunction, it is not a useful index with which to assess differences in gluconeogenic capacity.

Evaluation of Pressure Tensor in Constant-volume Simulations of Hard and Soft Convex Bodies

The Journal of Chemical Physics. Jun, 2006  |  Pubmed ID: 16774394

A method for calculating the pressure tensor in constant-volume Monte Carlo simulations of convex bodies is presented. In contrast to other approaches, the method requires only an isotropic scaling of the simulation box and the counting of simple geometric quantities characterizing overlapping pairs. Nonsphericity presents no special difficulties. The result is expressed as a sum of pairwise contributions and can therefore be used to compute pressure tensor profiles in a conventional way.

Facilitating Interpersonal Interaction and Learning Online: Linking Theory and Practice

The Journal of Continuing Education in the Health Professions. 2006  |  Pubmed ID: 16802307

An earlier study of physicians' perceptions of interactive online learning showed that these were shaped both by program design and quality and the quality and quantity of interpersonal interaction. We explore instructor roles in enhancing online learning through interpersonal interaction and the learning theories that inform these.

2,5-diketopiperazines As Potent, Selective, and Orally Bioavailable Oxytocin Antagonists. 3. Synthesis, Pharmacokinetics, and in Vivo Potency

Journal of Medicinal Chemistry. Jul, 2006  |  Pubmed ID: 16821776

A short, efficient, and highly stereoselective synthesis of a series of (3R,6R,7R)-2,5-diketopiperazine oxytocin antagonists and their pharmacokinetics in rat and dog is described. Prediction of the estimated human oral absorption (EHOA) using measured lipophilicity (CHI log D) and calculated size (cMR) has allowed us to rank various 2,5-diketopiperazine templates and enabled us to focus effort on those templates with the greatest chance of high bioavailability in humans. This rapidly led to the 2',4'-difluorophenyl-dimethylamide 25 and the benzofuran 4 with high levels of potency (pK(i)) and good bioavailability in the rat and dog. Dimethylamide 25 is more potent (>20-fold) than 4 in vivo and has a high degree of selectivity toward the vasopressin receptors, >10,000 for hV1a/hV1b and approximately 500 for hV2. It has a good Cyp450 profile with no time dependent inhibition and was negative in the genotoxicity screens with a satisfactory oral safety profile in rats.

Frequency Domain Analysis of Noise in Simple Gene Circuits

Chaos (Woodbury, N.Y.). Jun, 2006  |  Pubmed ID: 16822034

Recent advances in single cell methods have spurred progress in quantifying and analyzing stochastic fluctuations, or noise, in genetic networks. Many of these studies have focused on identifying the sources of noise and quantifying its magnitude, and at the same time, paying less attention to the frequency content of the noise. We have developed a frequency domain approach to extract the information contained in the frequency content of the noise. In this article we review our work in this area and extend it to explicitly consider sources of extrinsic and intrinsic noise. First we review applications of the frequency domain approach to several simple circuits, including a constitutively expressed gene, a gene regulated by transitions in its operator state, and a negatively autoregulated gene. We then review our recent experimental study, in which time-lapse microscopy was used to measure noise in the expression of green fluorescent protein in individual cells. The results demonstrate how changes in rate constants within the gene circuit are reflected in the spectral content of the noise in a manner consistent with the predictions derived through frequency domain analysis. The experimental results confirm our earlier theoretical prediction that negative autoregulation not only reduces the magnitude of the noise but shifts its content out to higher frequency. Finally, we develop a frequency domain model of gene expression that explicitly accounts for extrinsic noise at the transcriptional and translational levels. We apply the model to interpret a shift in the autocorrelation function of green fluorescent protein induced by perturbations of the translational process as a shift in the frequency spectrum of extrinsic noise and a decrease in its weighting relative to intrinsic noise.

Locus-specific Gene Expression Pattern Suggests a Unique Propagation Strategy for a Giant Algal Virus

Journal of Virology. Aug, 2006  |  Pubmed ID: 16840348

Emiliania huxleyi virus strain 86 is the largest algal virus sequenced to date and is unique among the Phycodnaviridae since its genome is predicted to contain six RNA polymerase subunit genes. We have used a virus microarray to profile the temporal transcription strategy of this unusual virus during infection. There are two distinct transcription phases to the infection process. The primary phase is dominated by a group of coding sequences (CDSs) expressed by 1 h postinfection that are localized to a subregion of the genome. The CDS of the primary group have no database homologues, and each is associated with a unique promoter element. The remainder of the CDSs are expressed in a secondary phase between 2 and 4 hours postinfection. Compartmentalized transcription of the two distinctive phases is discussed. We hypothesize that immediately after infection the nucleic acid of the virus targets the host nucleus, where primary-phase genes are transcribed by host RNA polymerase which recognizes the viral promoter. Secondary-phase transcription may then be conducted in the cytoplasm.

Subcellular Dynamics of Protein Kinase A Activity Visualized by FRET-based Reporters

Biochemical and Biophysical Research Communications. Sep, 2006  |  Pubmed ID: 16895723

cAMP-dependent protein kinase (PKA) mediates key cellular processes via compartmentalized activity, and the ability to track its activity in living cells should help increase our understanding of this precise regulation. Here, through systematic testing of new fluorescent proteins, we developed a new FRET-based A-kinase activity reporter (AKAR), AKAR3, with a dynamic range of 31-41%, twice that of predecessors. Visualization of PKA activity at plasma membrane, cytoplasm, nucleus, and mitochondria was achieved. Targeting AKAR3 to outer mitochondrial membrane revealed that basal PKA activity at mitochondria differs from that in the cytoplasm, indicating differential regulation of PKA activity at different subcellular locations.

Annotation of Environmental OMICS Data: Application to the Transcriptomics Domain

Omics : a Journal of Integrative Biology. 2006  |  Pubmed ID: 16901223

Researchers working on environmentally relevant organisms, populations, and communities are increasingly turning to the application of OMICS technologies to answer fundamental questions about the natural world, how it changes over time, and how it is influenced by anthropogenic factors. In doing so, the need to capture meta-data that accurately describes the biological "source" material used in such experiments is growing in importance. Here, we provide an overview of the formation of the "Env" community of environmental OMICS researchers and its efforts at considering the meta-data capture needs of those working in environmental OMICS. Specifically, we discuss the development to date of the Env specification, an informal specification including descriptors related to geographic location, environment, organism relationship, and phenotype. We then describe its application to the description of environmental transcriptomic experiments and how we have used it to extend the Minimum Information About a Microarray Experiment (MIAME) data standard to create a domain-specific extension that we have termed MIAME/Env. Finally, we make an open call to the community for participation in the Env Community and its future activities.

Structure of Molecular Liquids: Cavity and Bridge Functions of the Hard Spheroid Fluid

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Jun, 2006  |  Pubmed ID: 16906815

We present methodologies for calculating the direct correlation function c(1,2), the cavity function y(1,2), and the bridge function b(1,2), for molecular liquids, from Monte Carlo simulations. As an example we present results for the isotropic hard spheroid fluid with elongation e = 3. The simulation data are compared with the results from integral equation theory. In particular, we solve the Percus-Yevick and hypernetted chain equations. In addition, we calculate the first two terms in the virial expansion of the bridge function and incorporate this into the closure. At low densities, the bridge functions calculated by theory and from simulation are in good agreement, lending support to the correctness of our numerical procedures. At higher densities, the hypernetted chain results are brought into closer agreement with simulation by incorporating the approximate bridge function, but significant discrepancies remain.

The Response of Escherichia Coli to Exposure to the Biocide Polyhexamethylene Biguanide

Microbiology (Reading, England). Apr, 2006  |  Pubmed ID: 16549663

The global response of Escherichia coli to the broad-spectrum biocide polyhexamethylene biguanide (PHMB) was investigated using transcriptional profiling. The transcriptional analyses were validated by direct determination of the PHMB-tolerance phenotypes of derivatives of E. coli MG1655 carrying either insertionally inactivated genes and/or plasmids expressing the cognate open reading frames from a heterologous promoter in the corresponding chromosomally inactivated strains. The results showed that a wide range of genes was altered in transcriptional activity and that all of the corresponding knockout strains subsequently challenged with biocide were altered in tolerance. Of particular interest was the induction of the rhs genes and the implication of enzymes involved in the repair/binding of nucleic acids in the generation of tolerance, suggesting a novel dimension in the mechanism of action of PHMB based on its interaction with nucleic acids.

Evolutionary History of the Coccolithoviridae

Molecular Biology and Evolution. Jan, 2006  |  Pubmed ID: 16151186

We recently determined the genome sequence of the Coccolithoviridae strain Emiliania huxleyi virus 86 (EhV-86), a giant double-stranded DNA (dsDNA) algal virus from the family Phycodnaviridae that infects the marine coccolithophorid E. huxleyi. Here, we determine the phylogenetic relationship between EhV-86 and other large dsDNA viruses. Twenty-five core genes common to nuclear-cytoplasmic large dsDNA virus genomes were identified in the EhV-86 genome; sequence from eight of these genes were used to create a phylogenetic tree in which EhV-86 was placed firmly with the two other members of the Phycodnaviridae. We have also identified a 100-kb region of the EhV-86 genome which appears to have transferred into this genome from an unknown source. Furthermore, the presence of six RNA polymerase subunits (unique among the Phycodnaviridae) suggests both a unique evolutionary history and a unique lifestyle for this intriguing virus.

Clinical Policy: Critical Issues in the Diagnosis and Management of the Adult Psychiatric Patient in the Emergency Department

Annals of Emergency Medicine. Jan, 2006  |  Pubmed ID: 16387222

Are Antidepressants Associated with New-onset Suicidality in Bipolar Disorder? A Prospective Study of Participants in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD)

The Journal of Clinical Psychiatry. Jan, 2006  |  Pubmed ID: 16426088

Depressive episodes are common in bipolar disorder, and the disorder is characterized by high suicide rates. Recent analyses indicate a possible association of antidepressant treatment and suicidality in children and adults with depressive or anxiety disorders. However, few data are available to inform the suicidality risk assessment of antidepressant use specifically in bipolar disorder.

Linear Relationship of Valproate Serum Concentration to Response and Optimal Serum Levels for Acute Mania

The American Journal of Psychiatry. Feb, 2006  |  Pubmed ID: 16449481

Several studies have shown that achieving adequate serum valproate levels is critical to rapid stabilization of acute mania, but estimates of the target therapeutic level have been imprecise. A post hoc analysis of pooled intent-to-treat data from three randomized, placebo-controlled studies of divalproex treatment for acute mania was performed to test a hypothesized linear relationship between serum concentration and response and to determine optimal blood levels for treatment of acute mania.

Fat Supplements Affect Fractional Rates of Ruminal Fatty Acid Biohydrogenation and Passage in Dairy Cows

The Journal of Nutrition. Mar, 2006  |  Pubmed ID: 16484542

Rates of fatty acid biohydrogenation and passage were determined for fat supplements varying in saturation using lactating dairy cows. First-order fractional passage rates were determined by dividing the duodenal flux of fatty acids by their respective ruminal pool sizes. The determination of rates of biohydrogenation required the development of a model to account for the transfer of fatty acids among pools. Ruminally and duodenally cannulated multiparous Holstein cows (n = 8) were used in a replicated 4 x 4 Latin square design with 21-d periods. Treatments were control and a linear substitution of 25 g/kg supplemented fatty acids varying in saturation as follows: saturated (prilled hydrogenated free fatty acids), intermediate mix of saturated and unsaturated (calcium soaps of long-chain fatty acids), and partially unsaturated fatty acids. Passage rates of 16:0, 18:0, and total 18-carbon fatty acids were linearly decreased with increasing unsaturated fatty acids and the trans-18:1 fractional passage rate was quadratically affected with a maximum for the intermediate treatment. Increasing unsaturated fatty acids increased the extent of 18:2 and 18:3 biohydrogenation and decreased the extent of 18:1 and trans-18:1 biohydrogenation. Calcium salts did not protect PUFA from ruminal biohydrogenation despite a mean ruminal pH of 6.0, and unsaturated fatty acids decreased ruminal biohydrogenation of trans-18:1, resulting in increased duodenal flow of these fatty acids. The model allows a mechanistic description of ruminal biohydrogenation and determination of the extent of 18:1 biohydrogenation.

Configurational Temperature in Membrane Simulations Using Dissipative Particle Dynamics

The Journal of Physical Chemistry. B. Mar, 2006  |  Pubmed ID: 16494442

The use of excessively long time steps in dissipative particle dynamics simulations may produce simulation artifacts due to the generation of configurations which are not representative of the desired canonical ensemble. The configurational temperature, among other quantities, may be used to assess the extent of the deviation from equilibrium. This paper presents results for simulations of models of water and lipid bilayer membranes to illustrate the nature of the problems.

Heisenberg in the ER: Observation Appears to Reduce Involuntary Intramuscular Injections in a Psychiatric Emergency Service

General Hospital Psychiatry. Sep-Oct, 2006  |  Pubmed ID: 16950380

Chemical restraint is controversial. Appropriate use is ill-defined and chemical restraint may be overutilized. During the period of an unrelated observational study for patients with acute psychomotor agitation in a psychiatric emergency service, we noticed a significant reduction in the number of involuntary intramuscular injections administered.

Expression of a Novel Marine Viral Single-chain Serine Palmitoyltransferase and Construction of Yeast and Mammalian Single-chain Chimera

The Journal of Biological Chemistry. Dec, 2006  |  Pubmed ID: 17090526

The genus Coccolithovirus is a recently discovered group of viruses that infect the globally important marine calcifying microalga Emiliania huxleyi. Surprisingly, the viral genome contains a cluster of putative sphingolipid biosynthetic genes not found in other viral genus. To address the role of these genes in viral pathogenesis, the ehv050 gene predicted to encode a serine palmitoyltransferase (SPT), the first and rate-limiting enzyme of sphingolipid biosynthesis, was expressed and characterized in Saccharomyces cerevisiae. We show that the encoded protein is indeed a fully functional, endoplasmic reticulum-localized, single-chain SPT. In eukaryotes SPT is a heterodimer comprised of long chain base 1 (LCB1) and LCB2 subunits. Sequence alignment and mutational analysis showed that the N-terminal domain of the viral protein most closely resembled the LCB2 subunit and the C-terminal domain most closely resembled the LCB1 subunit. Regardless of whether the viral protein was expressed as a single polypeptide or as two independent domains, it exhibited an unusual preference for myristoyl-CoA rather than palmitoyl-CoA. This preference was reflected by the increased presence of C16-sphingoid bases in yeast cells expressing the viral protein. The occurrence of a single-chain SPT suggested to us that it might be possible to create other fusion SPTs with unique properties. Remarkably, when the two subunits of the yeast SPT were thus expressed, the single-chain chimera was functional and displayed a novel substrate preference. This suggests that expression of other multisubunit membrane proteins as single-chain chimera could provide a powerful approach to the characterization of integral membrane proteins.

Null Mutations in the Filaggrin Gene (FLG) Determine Major Susceptibility to Early-onset Atopic Dermatitis That Persists into Adulthood

The Journal of Investigative Dermatology. Mar, 2007  |  Pubmed ID: 16990802

Atopic dermatitis (AD) is a common disease with a complex etiology in childhood and adult life. A significant proportion of childhood AD is transient, but in many cases it persists into adulthood. We have recently shown that null mutations in the filaggrin gene (FLG) are an important predisposing factor for childhood eczema and eczema-associated asthma, but persistence to adulthood has not been analyzed. Here we studied a cohort of adult patients with persistent AD, which had been present since early childhood. In this cohort, the combined allele frequency of the two common FLG null variants was 0.270 (cf. population frequency 0.046). This represents an odds ratio of 7.7 with 95% confidence interval of 5.3-10.9 and a chi2 P-value of 1.7 x 10(-53). Our data conclusively demonstrate that identification of FLG null alleles is an indicator of a poor prognosis in AD, predisposing to a form of eczema that starts in early infancy and persists into adulthood. This study helps to further define the nature of the AD phenotype associated with FLG null alleles.

Advances in Hemoglobin A1c Point of Care Technology

Journal of Diabetes Science and Technology. May, 2007  |  Pubmed ID: 19885097

Measurement of hemoglobin A1c (A1C) has long been accepted as the best indicator of glucose control over time. Assays for A1C use technologies based on either charge differences (high-pressure liquid chromatography) or structure (boronate affinity or immunoassay combined with general chemistry). These technologies are generally employed in expensive laboratory instruments. More recently, A1C technology has been incorporated into point of care (POC) devices, allowing for immediate availability of A1C measurements, greatly facilitating diabetes care in both specialist and general practices. POC A1C tests should have acceptable performance, standardization to national reference, National Glycohemoglobin Standardization Program (NGSP) certification, simple operation without need for costly instrumentation, and Clinical Laboratory Improvement Amendments (CLIA) waiver. CLIA-waived POC technology includes Bio-Rad MicroMat II (distributed by Cholestech as GDX) and the Axis-Shield Afinion, both of which utilize boronate affinity. The DCA 2000(R)+ utilizes combined immunoassay and general chemistry. These instruments cost $1000 to $3000 and require regular maintenance, making them appropriate only for high-volume physician offices. The newly improved A1CNow+ also utilizes combined immunoassay and general chemistry, but the small, inexpensive, disposable monitor can be used by patients as well as by health care professionals. The new version of A1CNow+ has improved performance through recent introduction of automated solid state chemistry manufacturing, improved fluidics and automated assembly of the test cartridge, error-correcting software, and unitary meter calibration with factory calibration directly to the NGSP reference standard.

Direct Quantification of N-(3-oxo-hexanoyl)-L-homoserine Lactone in Culture Supernatant Using a Whole-cell Bioreporter

Journal of Microbiological Methods. Jan, 2007  |  Pubmed ID: 16916554

The autoinducer N-(3-oxo-hexanoyl)-L-homoserine lactone (3-oxo-C6-HSL) plays a significant role in the quorum-sensing system of the marine bacterium Vibrio fischeri. Upon forming a transcriptional activation complex with LuxR, 3-oxo-C6-HSL induces transcription of the luxICDABEG operon, leading to the increased production of both the 3-oxo-C6-HSL synthase (LuxI) and the bioluminescent proteins. In order to quantitatively analyze this regulatory mechanism, a novel approach was developed to measure 3-oxo-C6-HSL concentrations in V. fischeri cell culture supernatant. A bioluminescent strain of Escherichia coli that responds to 3-oxo-C6-HSL was used as a bioreporter. Although a linear response of the bioreporter to exogenously added synthetic 3-oxo-C6-HSL was found over several orders of magnitude, we show that bioreporter performance was dramatically impacted by variations in the supernatants using samples from a V. fischeri LuxI- strain. However, when maintained in the same supernatant background, the normalized peak bioluminescence maintained a linear response to 3-oxo-C6-HSL concentrations. Therefore, a standard additions technique was developed in which a known concentration of 3-oxo-C6-HSL was added to supernatant samples from wild-type V. fischeri cultures, and the incremental increase of the normalized peak bioluminescence relative to the untreated sample was determined. The concentration of 3-oxo-C6-HSL in the supernatant of the unknown sample was then quantified from the slope of the response between the normalized bioluminescent peaks with and without the addition of 3-oxo-C6-HSL. Advantages of this method are that it is rapid, does not require concentration or extraction, uses a small sample volume (ca. 2 ml), and accounts for effects caused by the composition of the supernatant. Furthermore, the findings can be broadly applicable to other bioreporter systems involving variable background conditions.

Common Mycorrhizal Networks Provide a Potential Pathway for the Transfer of Hydraulically Lifted Water Between Plants

Journal of Experimental Botany. 2007  |  Pubmed ID: 17350936

Plant roots may be linked by shared or common mycorrhizal networks (CMNs) that constitute pathways for the transfer of resources among plants. The potential for water transfer by such networks was examined by manipulating CMNs independently of plant roots in order to isolate the role(s) of ectomycorrhizal (EM) and arbuscular mycorrhizal fungal (AMF) networks in the plant water balance during drought (soil water potential -5.9 MPa). Fluorescent tracer dyes and deuterium-enriched water were used to follow the pathways of water transfer from coastal live oak seedlings (Quercus agrifolia Nee; colonized by EM and AMF) conducting hydraulic lift (HL) into the roots of water-stressed seedlings connected only by EM (Q. agrifolia) or AMF networks (Q. agrifolia, Eriogonum fasciculatum Benth., Salvia mellifera Greene, Keckiella antirrhinoides Benth). When connected to donor plants by hyphal linkages, deuterium was detected in the transpiration flux of receiver oak plants, and dye-labelled extraradical hyphae, rhizomorphs, mantles, and Hartig nets were observed in receiver EM oak roots, and in AMF hyphae of Salvia. Hyphal labelling was scarce in Eriogonum and Keckiella since these species are less dependent on AMF. The observed patterns of dye distribution also indicated that only a small percentage of mycorrhizal roots and extraradical hyphae were involved with water transfer among plants. Our results suggest that the movement of water by CMNs is potentially important to plant survival during drought, and that the functional ecophysiological traits of individual mycorrhizal fungi may be a component of this mechanism.

Use of Microarrays to Assess Viral Diversity: from Genotype to Phenotype

Environmental Microbiology. Apr, 2007  |  Pubmed ID: 17359269

The diversity among the coccolithovirus strains held in the Plymouth Virus Collection (PVC) was assessed using three complementary techniques: phylogeny based on DNA polymerase and major capsid protein gene sequence; host range; and a new, microarray-based genome-wide approach. The PVC is composed of three groups of strains that are geographically and temporally distinct. Virus strains clustered according to these groups in all three diversity assessments. Furthermore, the microarray approach based on genomic content showed that two strains, previously considered as identical to others in the PVC, are actually distinct. These results show the importance of genome-wide surveys for assessing strain diversity. Not only has the microarray provided an alternative to the phylogeny-derived pattern for virus evolution, it has also begun to provide some clues to the genes that may be responsible for the different phenotypes displayed by these viruses.

Measuring and Modeling Dispersal of Adult Zooplankton

Oecologia. Aug, 2007  |  Pubmed ID: 17375330

Habitat fragmentation poses an inherent problem for metacommunity dynamics, as dispersal among communities is hindered by increasing isolation and the loss of patches. Wetlands are one such system that have undergone excessive destruction and fragmentation in recent years. Zooplankton within these communities have historically been considered frequent and widespread dispersers, but direct, quantitative measures of zooplankton dispersal are rare. In this study, I performed two experiments to quantify zooplankton dispersal and to identify the primary dispersal vectors. I first set up an array of traps at 10, 30, 60, 120 and 180 m around an isolated pond to collect dispersing individuals. Nearly 1,500 adult zooplankton were captured in traps up to 180 m from the pond, with approximately 60% of dispersers being captured in traps at 10 m from the pond. A second experiment using open and animal-excluded traps suggested that large animals were the primary dispersal vector for these zooplankton. Using a subset of these data, I fit four models to describe the shape and magnitude of adult cladoceran dispersal at this site. All models showed the majority of cladocerans were deposited very close to the source pond, with three models suggesting that the trapping area encompassed 67% or more of the dispersal distances. These results suggest that adult zooplankton movement among ponds may be significant in areas where aquatic habitats are plentiful. Yet, in recent years climate change and anthropogenic disturbances have reduced the number and size of aquatic habitats in many regions of the world, likely curtailing effective transport of individuals in many cases. As a result, fragmented zooplankton metacommunities may experience increased dispersal limitation, stronger priority effects, higher levels of inbreeding and selection against traits engendering high dispersability.

Maritime Provinces Symposium on Health Technology Assessment

The Journal of Continuing Education in the Health Professions. 2007  |  Pubmed ID: 17385733

Effectiveness of Adjunctive Antidepressant Treatment for Bipolar Depression

The New England Journal of Medicine. Apr, 2007  |  Pubmed ID: 17392295

Episodes of depression are the most frequent cause of disability among patients with bipolar disorder. The effectiveness and safety of standard antidepressant agents for depressive episodes associated with bipolar disorder (bipolar depression) have not been well studied. Our study was designed to determine whether adjunctive antidepressant therapy reduces symptoms of bipolar depression without increasing the risk of mania.

Use of a Novel and Highly Selective Oxytocin Receptor Antagonist to Characterize Uterine Contractions in the Rat

American Journal of Physiology. Regulatory, Integrative and Comparative Physiology. Jul, 2007  |  Pubmed ID: 17395790

Spontaneous and induced uterine contractions in the rat were found to be inhibited by a novel and selective oxytocin receptor antagonist GSK221149A (3R,6R)-3-Indan-2-yl-1-[(1R)-1-(2-methyl-1,3-oxazol-4-yl)-2-morpholin-4-yl-2-oxoethyl]-6-[(1S)-1-methylpropyl]-2,5-piperazinedione. GSK221149A displayed nanomolar affinity (K(i) = 0.65 nM) for human recombinant oxytocin receptors with >1,400-fold selectivity over human V1a, V1b, and V2 receptors. GSK221149A had similar affinity (K(i) = 4.1 nM) and selectivity for native oxytocin receptors from rat and produced a functional, competitive block of oxytocin-induced contractions in isolated rat myometrial strips with a pA(2) value of 8.18. Intravenous administration of GSK221149A produced a dose-dependent decrease in oxytocin-induced uterine contractions in anesthetized rats with an ID(50) = 0.27 +/- 0.60 mg/kg (corresponding plasma concentrations were 88 ng/ml). Oral administration of GSK221149A (5 mg/kg) was effective in inhibiting oxytocin-induced uterine contractions after single and multiple (4-day) dosing. Spontaneous uterine contractions in late-term pregnant rats (19-21 days gestation) were significantly reduced by intravenous administration of 0.3 mg/kg of GSK221149A. These results provide further evidence that selective oxytocin receptor antagonism may offer an effective treatment for preterm labor.

Filaggrin Null Alleles Are Not Associated with Psoriasis

The Journal of Investigative Dermatology. Aug, 2007  |  Pubmed ID: 17410197

Psoriasis is a common skin disease with an etiology consistent with a multifactorial trait. Several psoriasis susceptibility loci are known, a number of which are also implicated in a predisposition to atopic dermatitis (AD), including the epidermal differentiation complex on chromosome 1q21. It has recently been shown in several replicate studies that prevalent null alleles for the filaggrin gene (FLG) on 1q21 are an important genetic factor in AD. Here, we examined the role of these FLG variants in psoriasis using case:control association studies comparing Irish and UK psoriasis cohorts (combined n=691) to ethnically matched populations (combined n=2117). No association was present for the two common European FLG mutations R501X and 2282del4 (combined chi2 P=0.989). In addition, the 3' end of the FLG open-reading frame was sequenced in a number of patients with differing types of psoriasis (plaque, guttate, palmoplantar, and late-onset), which excluded the possibility of a gain-of-function frameshift mutation such as those found in loricrin or certain keratin genes. These data suggest that FLG mutations are unlikely to be involved in genetic susceptibility to psoriasis and implies that there may be within-locus heterogeneity in chromosomal regions involved in both AD and psoriasis.

Manganese Deficiency in Chlamydomonas Results in Loss of Photosystem II and MnSOD Function, Sensitivity to Peroxides, and Secondary Phosphorus and Iron Deficiency

Plant Physiology. Jan, 2007  |  Pubmed ID: 17085511

For photoheterotrophic growth, a Chlamydomonas reinhardtii cell requires at least 1.7 x 10(7) manganese ions in the medium. At lower manganese ion concentrations (typically <0.5 microm), cells divide more slowly, accumulate less chlorophyll, and the culture reaches stationary phase at lower cell density. Below 0.1 microm supplemental manganese ion in the medium, the cells are photosynthetically defective. This is accompanied by decreased abundance of D1, which binds the Mn(4)Ca cluster, and release of the OEE proteins from the membrane. Assay of Mn superoxide dismutase (MnSOD) indicates loss of activity of two isozymes in proportion to the Mn deficiency. The expression of MSD3 through MSD5, encoding various isoforms of the MnSODs, is up-regulated severalfold in Mn-deficient cells, but neither expression nor activity of the plastid Fe-containing superoxide dismutase is changed, which contrasts with the dramatically increased MSD3 expression and plastid MnSOD activity in Fe-deficient cells. Mn-deficient cells are selectively sensitive to peroxide but not methyl viologen or Rose Bengal, and GPXs, APX, and MSRA2 genes (encoding glutathione peroxidase, ascorbate peroxidase, and methionine sulfoxide reductase 2) are slightly up-regulated. Elemental analysis indicates that the Mn, Fe, and P contents of cells in the Mn-deficient cultures were reduced in proportion to the deficiency. A natural resistance-associated macrophage protein homolog and one of five metal tolerance proteins were induced in Mn-deficient cells but not in Fe-deficient cells, suggesting that the corresponding gene products may be components of a Mn(2+)-selective assimilation pathway.

Violent Behavior of Patients Admitted in Emergency Following Drug Suicidal Attempt: a Specific Staff Educational Crisis Intervention

General Hospital Psychiatry. Jan-Feb, 2007  |  Pubmed ID: 17189744

In spite of much effort to create guidelines on the management of violent behavior (VB) in emergency departments, little is known about the impact of such guidelines on a real-life emergency environment. The aim of this study is to investigate the impact of a staff educational crisis intervention (SECI) on the reduction of VB in patients admitted to emergency departments following drug suicidal attempt.

Intramuscular Olanzapine in Patients with Borderline Personality Disorder: an Observational Study in an Emergency Room

General Hospital Psychiatry. Jan-Feb, 2007  |  Pubmed ID: 17189746

Despite the frequency of borderline personality disorder (BPD) in patients with acute agitation in emergency departments (EDs), there are few data about the use of intramuscular (IM) psychotropics in those patients. This is the first open-label study with olanzapine in this setting.

Water Source Partitioning Among Trees Growing on Shallow Karst Soils in a Seasonally Dry Tropical Climate

Oecologia. May, 2007  |  Pubmed ID: 17216213

The sources of water used by woody vegetation growing on karst soils in seasonally dry tropical regions are little known. In northern Yucatan (Mexico), trees withstand 4-6 months of annual drought in spite of the small water storage capacity of the shallow karst soil. We hypothesized that adult evergreen trees in Yucatan tap the aquifer for a reliable supply of water during the prolonged dry season. The naturally occurring concentration gradients in oxygen and hydrogen stable isotopes in soil, bedrock, groundwater and plant stem water were used to determine the sources of water used by native evergreen and drought-deciduous tree species. While the trees studied grew over a permanent water table (9-20 m depth), pit excavation showed that roots were largely restricted to the upper 2 m of the soil/bedrock profile. At the peak of the dry season, the delta(18)O signatures of potential water sources for the vegetation ranged from 4.1 +/- 1.1 per thousand in topsoil to -4.3 +/- 0.1 per thousand in groundwater. The delta(18)O values of tree stem water ranged from -2.8 +/- 0.3 per thousand in Talisia olivaeformis to 0.8 +/- 1 per thousand in Ficus cotinifolia, demonstrating vertical partitioning of soil/bedrock water among tree species. Stem water delta(18)O values were significantly different from that of groundwater for all the tree species investigated. Stem water samples plotted to the right of the meteoric water line, indicating utilization of water sources subject to evaporative isotopic enrichment. Foliar delta(13)C in adult trees varied widely among species, ranging from -25.3 +/- 0.3 per thousand in Enterolobium cyclocarpum to -28.7 +/- 0.4 per thousand in T. olivaeformis. Contrary to initial expectations, data indicate that native trees growing on shallow karst soils in northern Yucatan use little or no groundwater and depend mostly on water stored within the upper 2-3 m of the soil/bedrock profile. Water storage in subsurface soil-filled cavities and in the porous limestone bedrock is apparently sufficient to sustain adult evergreen trees throughout the pronounced dry season.

Viewing Videotape of Themselves While Experiencing Delirium Tremens Could Reduce the Relapse Rate in Alcohol-dependent Patients

Addiction (Abingdon, England). Feb, 2007  |  Pubmed ID: 17222276

The aim of this prospective randomized controlled study was to determine whether viewing videotape of themselves while experiencing delirium tremens (DT) reduces the relapse rate in alcohol-dependent patients. Our hypothesis about the efficacy of videotapes exposure to DT is consistent with a cognitive behavior model.

Phlorizin Administration Does Not Attenuate Hypophagia Induced by Intraruminal Propionate Infusion in Lactating Dairy Cattle

The Journal of Nutrition. Feb, 2007  |  Pubmed ID: 17237306

Infusion data from ruminants has shown that propionate stimulates satiety and decreases meal size, possibly because of increased propionate oxidation in the liver. In this experiment, phlorizin was used to increase glucose demand, which was expected to decrease propionate oxidation and attenuate the decrease in dry matter intake (DMI) caused by propionate infusion. Twelve multiparous, ruminally-cannulated Holstein cows (49+/-33 d in milk, 40+/-7 kg/d milk; mean+/-SD) were randomly assigned to square and treatment sequence in a replicated 4x4 Latin square experiment with a 2x2 factorial arrangement of treatments. Treatments were subcutaneous injection of phlorizin or propylene glycol in combination with intraruminal infusion of either Na acetate or Na propionate. Following a 7-d adaptation period, phlorizin (4 g/d) and control injections were administered every 6 h for 7 d. During the final 2 d of injections, Na acetate or Na propionate solutions (1 mol/L, pH 6.0) were infused continuously at the rate of 0.80 L/h. Feeding behavior data were collected during the final 2 d of treatment. Phlorizin caused urinary excretion of 400+/-40 g glucose/d across infusion treatments. Phlorizin tended to increase plasma free fatty acid and beta-hydroxybutyrate concentrations to a greater extent with Na acetate compared to Na propionate infusion (both interactions P<0.15). Phlorizin decreased and Na propionate increased plasma insulin and glucose concentrations. Infusion of Na propionate decreased DMI (18.4 vs. 21.1+/-1.4 kg/d, P<0.001) through an increase in intermeal interval (89.2 vs. 77.3+/-6.6 min, P=0.03), resulting in fewer meals per day (11.6 vs. 13.7+/-0.7, P<0.001). Phlorizin did not alter DMI (P=0.39) or measures of feeding behavior, nor were there interactions with infusion type. Increasing glucose demand does not limit the extent to which propionate decreases DMI in lactating dairy cows.

Comparative Analysis of Endodontic Pathfinders

Journal of Endodontics. Jun, 2007  |  Pubmed ID: 17509414

Because no scientific literature exists regarding endodontic pathfinders, the aim of this study was to compare such instruments. Ten different pathfinder-type files were analyzed with respect to dimensional characteristics, pitch, and rigidity; efficiency, wear, and distortion were assessed by using an in vitro simulation exercise. SEM cross-sections and tip images were obtained and analyzed. To assess efficacy and distortion, 10 operators attempted to achieve patency with the files in small, S-shaped canals in acrylic blocks. Trends in canal negotiation efficiency and file distortion were recorded. Results showed that the Hi-5 (Miltex, York, PA) and C+ files (Dentsply/Maillefer, Johnson City, TN) were the least flexible, whereas the Pathfinder CS (SybronEndo, Glendora, CA) and Pathfinder SS (SybronEndo) files were the most. Pathfinder SS, S finder (JSDental/Sendoline, Ridgefield, CT), and D finder (Mani, Tochigi-ken, Japan) were the most efficient during the simulation exercise. Within the parameters of this study, pitch, taper, cross-section, heat tempering, metal type, tip geometry, and operator skills all influenced pathfinder efficiency.

Cardiology Grand Rounds: Effect of Videoconferencing on Educational Value

Journal of Telemedicine and Telecare. 2007  |  Pubmed ID: 17519055

We studied four cardiology grand rounds transmitted by videoconference from a tertiary care centre to four other hospitals in eastern Canada. We collected data with evaluation questionnaires and by video recording participants at the receiving-site and the presentation they received from the presenting site. Receiving-site participants (n=20) rated their satisfaction with all domains significantly lower than did presenting-site participants (n=49). The greatest difference in ratings was in the ability to see slides (receiving sites 2.6/5, presenting site 4.6/5). Review of video recordings revealed that slides showing material copied from print sources was difficult to read at receiving sites. While 56% of discussion time was devoted to questions from receiving sites, participants there rated their ability to participate in discussion lower than those at the presenting site (3.9/5 vs 4.4/5). This may be because some parts of the discussion from the presenting site were not transmitted. Receiving-site participants rated the educational value of the rounds lower than their presenting-site colleagues (3.9/5 vs 4.4/5) but answered a similar percentage of knowledge questions correctly (85 vs 89%).

Efficacy and Safety of Oral Aripiprazole Compared with Haloperidol in Patients Transitioning from Acute Treatment with Intramuscular Formulations

Journal of Psychiatric Practice. May, 2007  |  Pubmed ID: 17522560

To report efficacy and safety of transitioning patients receiving intramuscular (IM) formulations of aripiprazole or haloperidol to their respective oral formulations.

Wide Geographical and Ecological Distribution of Nitrogen and Carbon Gains from Fungi in Pyroloids and Monotropoids (Ericaceae) and in Orchids

The New Phytologist. 2007  |  Pubmed ID: 17547676

* Stable isotope abundance analyses recently revealed that some European green orchids and pyroloids (Ericaceae) are partially myco-heterotrophic, exploiting mycorrhizal fungi for organic carbon and nitrogen. Here we investigate related species to assess their nutritional mode across various forest and climate types in Germany and California. * C- and N-isotope signatures of five green pyroloids, three green orchids and several obligate myco-heterotrophic species (including the putatively fully myco-heterotrophic Pyrola aphylla) were analysed to quantify the green plants' nutrient gain from their fungal partners and to investigate the constancy of enrichment in (13)C and (15)N of fully myco-heterotrophic plants from diverse taxa and locations relative to neighbouring autotrophic plants. * All green pyroloid and one orchid species showed significant (15)N enrichment, confirming incorporation of fungi-derived N compounds while heterotrophic C gain was detected only under low irradiance in Orthilia secunda. Pyrola aphylla had an isotope signature equivalent to those of fully myco-heterotrophic plants. * It is demonstrated that primarily N gain from mycorrhizal fungi occurred in all taxonomic groups investigated across a wide range of geographical and ecological contexts. The (13)C and (15)N enrichment of obligate myco-heterotrophic plants relative to accompanying autotrophic plants turned out as a fairly constant parameter.

Water Soluble Metallo-phthalocyanines: the Role of the Functional Groups on the Spectral and Photophysical Properties

Journal of Fluorescence. Sep, 2007  |  Pubmed ID: 17574523

Strategies are reported that produce symmetrical metal-free and metallo-phthalocyanine dyes, Pc and MPc, respectively, containing various numbers of water solubilizing carboxylic acid groups on their periphery that provide a dual role by also serving as functional groups to covalently link primary amine-containing targets to these dyes. In order to induce water compatibility and to minimize the degree of aggregation, the periphery of the macrocycle was decorated with various numbers of water-solubilizing groups and/or altering the identity of the metal center. The influence of the number of solubilizing groups and metal center on the spectral and photophysical properties were evaluated. MPc dyes containing 4, 8, or 16 carboxylic acid groups exhibited similar absorption and emission maxima (677 and 686 nm, respectively) with the molar absorptivity of the Q-band approximately 10(5) M(-1) cm(-1). Results indicated that the fluorescence lifetimes and quantum yields varied as a function of the metal center; the degree of carboxylation did not significantly alter these properties in DMSO, but did mediate the solubility and aggregation states when placed in aqueous solvents. The water solubilizing groups could also serve as labeling moieties for targets bearing primary amines. Results showed that the conjugate, produced by covalently linking an MPc to streptavidin through one of its carboxylate groups, generated a red-shift in the emission maximum with a fluorescence lifetime shorter than that of the native MPc dye.

FEA1, FEA2, and FRE1, Encoding Two Homologous Secreted Proteins and a Candidate Ferrireductase, Are Expressed Coordinately with FOX1 and FTR1 in Iron-deficient Chlamydomonas Reinhardtii

Eukaryotic Cell. Oct, 2007  |  Pubmed ID: 17660359

Previously, we had identified FOX1 and FTR1 as iron deficiency-inducible components of a high-affinity copper-dependent iron uptake pathway in Chlamydomonas. In this work, we survey the version 3.0 draft genome to identify a ferrireductase, FRE1, and two ZIP family proteins, IRT1 and IRT2, as candidate ferrous transporters based on their increased expression in iron-deficient versus iron-replete cells. In a parallel proteomic approach, we identified FEA1 and FEA2 as the major proteins secreted by iron-deficient Chlamydomonas reinhardtii. The recovery of FEA1 and FEA2 from the medium of Chlamydomonas strain CC425 cultures is strictly correlated with iron nutrition status, and the accumulation of the corresponding mRNAs parallels that of the Chlamydomonas FOX1 and FTR1 mRNAs, although the magnitude of regulation is more dramatic for the FEA genes. Like the FOX1 and FTR1 genes, the FEA genes do not respond to copper, zinc, or manganese deficiency. The 5' flanking untranscribed sequences from the FEA1, FTR1, and FOX1 genes confer iron deficiency-dependent expression of ARS2, suggesting that the iron assimilation pathway is under transcriptional control by iron nutrition. Genetic analysis suggests that the secreted proteins FEA1 and FEA2 facilitate high-affinity iron uptake, perhaps by concentrating iron in the vicinity of the cell. Homologues of FEA1 and FRE1 were identified previously as high-CO(2)-responsive genes, HCR1 and HCR2, in Chlorococcum littorale, suggesting that components of the iron assimilation pathway are responsive to carbon nutrition. These iron response components are placed in a proposed iron assimilation pathway for Chlamydomonas.

Current Suicide Ideation and Prior Suicide Attempts of Bipolar Patients As Influences on Caregiver Burden

Suicide & Life-threatening Behavior. Aug, 2007  |  Pubmed ID: 17896888

We examined whether caregivers of bipolar patients reporting current suicidal ideation and/or a history of a suicide attempt reported higher levels of burden and/or poorer health compared to caregivers of patients without these suicidality indices. In a cross-sectional design, caregivers (N = 480) associated with (a) patients with current suicidal ideation or (b) patients with a positive lifetime history of at least one suicide attempt, reported lower general health scores than caregivers associated with patients with neither of these indices. Parents of patients with at least one lifetime attempt reported more burden secondary to role dysfunction than spouses. Levels of depression in caregivers varied with whether the caregiver was a spouse or a parent, and whether patients had a history of suicide attempts, current suicidal ideation, or both.

Managing the Acutely Agitated and Psychotic Patient

CNS Spectrums. Oct, 2007  |  Pubmed ID: 17934384

Agitation can present as an emergency in the course of numerous psychiatric conditions including intoxication, schizophrenia, bipolar disorder, and delirium. This article reviews relevant literature regarding the definition, etiology, measurement, and management of episodic agitation and pays particular attention to intramuscular treatments. The impact of changes in methodology between the era of first- and second-generation antipsychotics, the implications of those changes for external validity of studies of second-generation studies, and the recent evolution of expert consensus are discussed.

Family Physicians' Perceptions of Academic Detailing: a Quantitative and Qualitative Study

BMC Medical Education. 2007  |  Pubmed ID: 17935614

The efficacy of academic detailing in changing physicians' knowledge and practice has been the subject of many primary research publications and systematic reviews. However, there is little written about the features of academic detailing that physicians find valuable or that affect their use of it. The goal of our project was to explore family physicians' (FPs) perceptions of academic detailing and the factors that affect their use of it.

FRET-based Biosensors for Protein Kinases: Illuminating the Kinome

Molecular BioSystems. Nov, 2007  |  Pubmed ID: 17940658

Protein kinases are crucial components of intracellular signaling pathways which transmit signals by phosphorylation of downstream targets, altering their function. Efficient signal transduction requires precise kinase regulation within specific biological contexts, making tools that allow study of their dynamics in situ critical for understanding kinase function. Highlighted in this article is the design of genetically-encodable, FRET-based kinase biosensors with examples of their implementation to study kinase regulation in live biological contexts with high spatial and temporal resolution.

Quality of Care in Emergency Psychiatry: Developing an International Network

European Psychiatry : the Journal of the Association of European Psychiatrists. Sep, 2007  |  Pubmed ID: 17948351

Concurrent Tracking of Alcohol Use and Bipolar Disorder Symptoms

Bipolar Disorders. Nov, 2007  |  Pubmed ID: 17988372

Structure of Molecular Liquids: Closure Relations for Hard Spheroids

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Oct, 2007  |  Pubmed ID: 17994971

We present the results of Monte Carlo simulations of hard spheroids of revolution of different elongations. Both prolate and oblate shapes are examined. A systematic study of the bridge function b(1,2), and direct comparison with the indirect correlation function gamma(1,2)=h(1,2)-c(1,2) at densities spanning the isotropic fluid range, allow us to evaluate the accuracy of various proposed closure relations for integral equations.

Liquid-crystal-mediated Force Between a Cylindrical Nanoparticle and Substrate

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Oct, 2007  |  Pubmed ID: 17995012

Using classical density functional theory, the structure of a molecular fluid around a cylindrical nanoparticle near a solid substrate is studied. The solvent-mediated force between the nanoparticle and the substrate is calculated in both the nematic and isotropic phases of the solvent. In the nematic phase, the force is short ranged and arises due to interaction between high-density regions near the substrate and nanoparticle. In the isotropic phase, the formation of a nematic bridge between the substrate and nanoparticle gives rise to an attractive force between them. The potential between the nanoparticle and substrate as a function of separation calculated numerically is compared to that calculated from the Derjaguin approximation. In the isotropic phase these are found to be in reasonable agreement at low separations, while the agreement is poorer in the nematic phase.

The Organization of Psychiatric Emergency Services and Related Differences in Restraint Practices

General Hospital Psychiatry. Nov-Dec, 2007  |  Pubmed ID: 18022037

Metallo-phthalocyanine Near-IR Fluorophores: Oligonucleotide Conjugates and Their Applications in PCR Assays

Bioconjugate Chemistry. Nov-Dec, 2007  |  Pubmed ID: 18030995

Water soluble, metallo-pthalocyanine (MPc) near-IR fluorophores were designed, synthesized, and evaluated as highly stable and sensitive reporters for fluorescence assays. Their conjugation to oligonucleotides was achieved via succinimidyl ester-amino coupling chemistry with the conditions for conjugation extensively examined and optimized. In addition, various conjugate purification and isolation techniques were evaluated as well. Results showed that under proper conditions and following purification using reverse-phase ion-pair chromatography, labeling efficiencies near 80% could be achieved using ZnPc (Zn phthalocyanine) as the labeling fluorophore. Absorption and fluorescence spectra accumulated for the conjugates indicated that the intrinsic fluorescence properties of the MPc's were not significantly altered by covalent attachment to oligonucleotides. As an example of the utility of MPc reporters, we used the MPc-oligonucleotide conjugates as primers for PCR (polymerase chain reaction) amplifications with the products sorted via electrophoresis and detected using near-IR fluorescence (lambda ex = 680 nm). The MPc dyes were found to be more chemically stable under typical thermal cycling conditions used for PCR compared to the carbocyanine-based near-IR reporter systems typically used and produced single and narrow bands in the electrophoretic traces, indicative of producing a single PCR product during amplification.

Pilot Study of an EST Approach of the Coccolithophorid Emiliania Huxleyi During a Virus Infection

Gene. Dec, 2007  |  Pubmed ID: 18035506

Blooms of the coccolithophorid Emiliania huxleyi can be infected by viruses, which can lead to bloom-termination. This pilot study used an expressed sequence tag (EST) approach to get a first view of gene-expression changes that occur during viral infection of E. huxleyi. cDNA libraries were constructed from uninfected cultures and 6, 12, and 24 h after infection with E. huxleyi-specific virus 86 (EhV-86). From each library 60-90 ESTs were randomly selected and annotated manually with PhyloGena. Viral genes were identified using BLAST-Search of the known viral genome. The data of this study show, that 6 h after viral infection the algal transcriptome changed significantly although few viral transcripts were present. At this point, changes mainly concerned transcripts related to photosynthesis and protein metabolism. However, after 24 h viral transcripts were most abundant. Viral transcripts found at this stage of viral infection encode proteins involved in protein degradation, nucleic acid degradation, transcription and replication.

A Destabilized Bacterial Luciferase for Dynamic Gene Expression Studies

Systems and Synthetic Biology. Mar, 2007  |  Pubmed ID: 19003433

Fusions of genetic regulatory elements with reporter genes have long been used as tools for monitoring gene expression and have become a major component in synthetic gene circuit implementation. A major limitation of many of these systems is the relatively long half-life of the reporter protein(s), which prevents monitoring both the initiation and the termination of transcription in real-time. Furthermore, when used as components in synthetic gene circuits, the long time constants associated with reporter protein decay may significantly degrade circuit performance. In this study, short half-life variants of LuxA and LuxB from Photorhabdus luminescens were constructed in Escherichia coli by inclusion of an 11-amino acid carboxy-terminal tag that is recognized by endogenous tail-specific proteases. Results indicated that the addition of the C-terminal tag affected the functional half-life of the holoenzyme when the tag was added to luxA or to both luxA and luxB, but modification of luxB alone did not have a significant effect. In addition, it was also found that alteration of the terminal three amino acid residues of the carboxy-terminal tag fused to LuxA generated variants with half-lives of intermediate length in a manner similar to that reported for GFP. This report is the first instance of the C-terminal tagging approach for the regulation of protein half-life to be applied to an enzyme or monomer of a multi-subunit enzyme complex and will extend the utility of the bacterial luciferase reporter genes for the monitoring of dynamic changes in gene expression.

Effect of Substrate Geometry on Liquid-crystal-mediated Nanocylinder-substrate Interactions

The Journal of Chemical Physics. Sep, 2008  |  Pubmed ID: 19044979

Using classical density functional theory, the liquid crystal (LC)-mediated interaction between a cylindrical nanoparticle and a structured substrate is studied. The surface is structured by cutting a rectangular groove into the surface. In the absence of the nanoparticle, a range of defect structures is formed in the vicinity of the groove. By varying the groove width and depth, the LC-mediated interaction changes from repulsive to attractive. This interaction is strongest when the groove is of comparable size to the nanoparticle. For narrow grooves the nanoparticle is attracted to the center of the groove, while for wider grooves there is a free energy minimum near the sidewalls.

Regulation and Localization of Isoforms of the Aerobic Oxidative Cyclase in Chlamydomonas Reinhardtii

Photochemistry and Photobiology. Nov-Dec, 2008  |  Pubmed ID: 19067954

Tetrapyrrole synthesis is complex and is regulated at several points. The aerobic oxidative cyclase catalyzes the oxidative closure of the fifth ring characteristic of all chlorophylls. Chlamydomonas reinhardtii encodes two paralogous protein components of the cyclase, which are differentially accumulated based on copper nutrition and oxygen supply. CRD1 is accumulated in copper-deficient conditions, whereas CTH1 is present in copper replete conditions. Here, we show that CRD1 expression is regulated through a copper-responsive element located upstream of the transcription start site. The differential production of CRD1 transcript accounts for the differential accumulation of the corresponding polypeptide. The CTH1 locus produces two transcripts: a 2.1 kb one under copper-replete conditions and a 3.1 kb one under copper-deficient conditions. We show that the 2.1 kb transcript can be translated into protein in vitro whereas the 3.1 kb transcript cannot. Differential accumulation of the 2.1 vs the 3.1 kb transcript therefore accounts for the copper-responsive accumulation of CTH1. Biochemical fractionation reveals that both CRD1 and CTH1 are localized to chloroplast envelope as well as thylakoid membranes.

Environmental Controls and the Influence of Vegetation Type, Fine Roots and Rhizomorphs on Diel and Seasonal Variation in Soil Respiration

The New Phytologist. Jul, 2008  |  Pubmed ID: 19086292

Characterization of spatial and temporal variation of soil respiration coupled with fine root and rhizomorph dynamics is necessary to understand the mechanisms that regulate soil respiration. A dense wireless network array of soil CO2 sensors in combination with minirhizotron tubes was used to continuously measure soil respiration over 1 yr in a mixed conifer forest in California, USA, in two adjacent areas with different vegetation types: an area with woody vegetation (Wv) and an area with scattered herbaceous vegetation (Hv). Annual soil respiration rates and the lengths of fine roots and rhizomorphs were greater at Wv than at Hv. Soil respiration was positively correlated with fine roots and rhizomorphs at Wv but only with fine roots at Hv. Diel and seasonal soil respiration patterns were decoupled with soil temperature at Wv but not at Hv. When decoupled, higher soil respiration rates were observed at increasing temperatures, demonstrating a hysteresis effect. The diel hysteresis at Wv was explained by including the temperature-dependent component of soil respiration and the variation dependent on photosynthetically active radiation. The results show that vegetation type and fine root and rhizomorph dynamics influence soil respiration in addition to changes in light, temperature and moisture.

Elastic Constants of Hard Thin Platelets by Monte Carlo Simulation and Virial Expansion

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Nov, 2008  |  Pubmed ID: 19113141

In this paper we present an investigation into the calculation of the Frank elastic constants of hard platelets via molecular simulation and virial expansion beyond second order. Monte Carlo simulations were carried out and director fluctuations measured as a function of wave vector k, giving the elastic constants through a fit in the low-k limit. Additionally, the virial expansion coefficients of the elastic constants up to sixth order were calculated, and the validity of the theory determined by comparison with the simulation results. The simulation results are also compared with experimental measurements on colloidal suspensions of platelike particles.

The Relationship of Sex and Risk Behaviours to Students' Use of School-based Health Centres in Cape Breton, Nova Scotia

Paediatrics & Child Health. Sep, 2008  |  Pubmed ID: 19436499

Among other benefits, school-based health centres (SBHCs) are thought to provide opportunities to identify and help adolescents with risk-taking behaviours. The present study examined the use of SBHCs at three high schools in Cape Breton, Nova Scotia, to determine the extent to which SBHCs reach students at risk, and whether there are sex differences with respect to this reach.

A Tunable FRET Circuit for Engineering Fluorescent Biosensors

Angewandte Chemie (International Ed. in English). 2008  |  Pubmed ID: 18058965

Forces Between Cylindrical Nanoparticles in a Liquid Crystal

Langmuir : the ACS Journal of Surfaces and Colloids. Feb, 2008  |  Pubmed ID: 18179263

Using classical density functional theory, the forces between two cylindrical nanoparticles in a liquid crystal solvent are calculated. Both the nematic and isotropic phases of the solvent are considered. In the nematic phase, the interaction is highly anisotropic. At short range, changes in the defect structure around the cylinders leads to a complex interaction between them. In the isotropic phase, an attractive interaction arises due to overlap between halos of ordered fluid adsorbed on the surfaces of the cylinders.

The Prospective Course of Rapid-cycling Bipolar Disorder: Findings from the STEP-BD

The American Journal of Psychiatry. Mar, 2008  |  Pubmed ID: 18198271

In a naturalistic follow-up of adult bipolar patients, the authors examined the contributions of demographic, phenomenological, and clinical variables, including antidepressant use, to prospectively observed mood episode frequency.

Proteomic Analysis of the EhV-86 Virion

Proteome Science. 2008  |  Pubmed ID: 18346272

Emiliania huxleyi virus 86 (EhV-86) is the type species of the genus Coccolithovirus within the family Phycodnaviridae. The fully sequenced 407,339 bp genome is predicted to encode 473 protein coding sequences (CDSs) and is the largest Phycodnaviridae sequenced to date. The majority of EhV-86 CDSs exhibit no similarity to proteins in the public databases.

Structure of Molecular Liquids: Hard Rod-disk Mixtures

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Jan, 2008  |  Pubmed ID: 18351843

The structure of hard rod-disk mixtures is studied using Monte Carlo simulations and integral equation theory, for a range of densities in the isotropic phase. By extension of methods used in single component fluids, the pair correlation functions of the molecules are calculated and comparisons between simulation and integral equation theory, using a number of different closure relations, are made. Comparison is also made for thermodynamic data and phase behavior.

Identification of ZNF313/RNF114 As a Novel Psoriasis Susceptibility Gene

Human Molecular Genetics. Jul, 2008  |  Pubmed ID: 18364390

Psoriasis is an immune-mediated skin disorder that is inherited as a multifactorial trait. Linkage studies have clearly identified a primary disease susceptibility locus lying within the major histocompatibility complex (MHC), but have generated conflicting results for other genomic regions. To overcome this difficulty, we have carried out a genome-wide association scan, where we analyzed more than 408,000 SNPs in an initial sample of 318 cases and 288 controls. Outside of the MHC, we observed a single cluster of disease-associated markers, spanning 47 kb on chromosome 20q13. The analysis of two replication data sets confirmed this association, with SNP rs495337 yielding a combined P-value of 1.4 x 10(-8) in an overall sample of 2679 cases and 2215 controls. Rs495337 maps to the SPATA2 transcript and is in absolute linkage disequilibrium with five SNPs lying in the adjacent ZNF313 gene (also known as RNF114). Real-time PCR experiments showed that, unlike SPATA2, ZNF313 is abundantly expressed in skin, T-lymphocytes and dendritic cells. Furthermore, an analysis of the expression data available from the Genevar database indicated that rs495337 is associated with increased ZNF313 transcripts levels (P = 0.003), suggesting that the disease susceptibility allele may be a ZNF313 regulatory variant tagged by rs495337. Homology searches indicated that ZNF313 is a paralogue of TRAC-1, an ubiquitin ligase regulating T-cell activation. We performed cell-free assays and confirmed that like TRAC-1, ZNF313 binds ubiquitin via an ubiquitin-interaction motif (UIM). These findings collectively identify a novel psoriasis susceptibility gene, with a putative role in the regulation of immune responses.

A Naturalistic Study of Consecutive Agitated Emergency Department Patients Treated with Intramuscular Olanzapine Prior to Consent

The American Journal of Psychiatry. Apr, 2008  |  Pubmed ID: 18381919

Case-control Analyses of the Impact of Pharmacotherapy on Prospectively Observed Suicide Attempts and Completed Suicides in Bipolar Disorder: Findings from STEP-BD

The Journal of Clinical Psychiatry. Jun, 2008  |  Pubmed ID: 18399724

Given high rates of suicide and suicide attempts in bipolar disorder and the data suggesting a suicide-protective effect of lithium, we evaluated the impact of pharmacotherapy on prospectively observed suicides and suicide attempts in subjects in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD).

Factors Associated with the Use of Physical Restraints for Agitated Patients in Psychiatric Emergency Rooms

General Hospital Psychiatry. May-Jun, 2008  |  Pubmed ID: 18433659

To examine factors associated with physical restraint in psychiatric emergency rooms.

The Minimum Information About a Genome Sequence (MIGS) Specification

Nature Biotechnology. May, 2008  |  Pubmed ID: 18464787

With the quantity of genomic data increasing at an exponential rate, it is imperative that these data be captured electronically, in a standard format. Standardization activities must proceed within the auspices of open-access and international working bodies. To tackle the issues surrounding the development of better descriptions of genomic investigations, we have formed the Genomic Standards Consortium (GSC). Here, we introduce the minimum information about a genome sequence (MIGS) specification with the intent of promoting participation in its development and discussing the resources that will be required to develop improved mechanisms of metadata capture and exchange. As part of its wider goals, the GSC also supports improving the 'transparency' of the information contained in existing genomic databases.

FER1 and FER2 Encoding Two Ferritin Complexes in Chlamydomonas Reinhardtii Chloroplasts Are Regulated by Iron

Genetics. May, 2008  |  Pubmed ID: 18493046

Two unlinked genes FER1 and FER2 encoding ferritin subunits were identified in the Chlamydomonas genome. An improved FER2 gene model, built on the basis of manual sequencing and incorporation of unplaced reads, indicated 49% identity between the ferritin subunits. Both FER1 and FER2 transcripts are increased in abundance as iron nutrition is decreased but the pattern for each gene is distinct. Using subunit-specific antibodies, we monitored expression at the protein level. In response to low iron, ferritin1 subunits and the ferritin1 complex are increased in parallel to the increase in FER1 mRNA. Nevertheless, the iron content of the ferritin1 complex is decreased. This suggests that increased expression results in increased capacity for iron binding in the chloroplast of iron-limited cells, which supports a role for ferritin1 as an iron buffer. On the other hand, ferritin2 abundance is decreased in iron-deprived cells, indicative of the operation of iron-nutrition-responsive regulation at the translational or post-translational level for FER2. Both ferritin subunits are plastid localized but ferritin1 is quantitatively recovered in soluble extracts of cells while ferritin2 is found in the particulate fraction. Partial purification of the ferritin1 complex indicates that the two ferritins are associated in distinct complexes and do not coassemble. The ratio of ferritin1 to ferritin2 is 70:1 in iron-replete cells, suggestive of a more dominant role of ferritin1 in iron homeostasis. The Volvox genome contains orthologs of each FER gene, indicating that the duplication of FER genes and potential diversification of function occurred prior to the divergence of species in the Volvocales.

Evaluation of Injury Databases As a Preliminary Step to Developing a Triage Decision Rule

Journal of Nursing Scholarship : an Official Publication of Sigma Theta Tau International Honor Society of Nursing / Sigma Theta Tau. 2008  |  Pubmed ID: 18507569

To evaluate accessibility and appropriateness of the Crash Outcomes Data Evaluation Systems (CODES) databases for prehospital trauma triage decision-rule development for people age 65 years and older.

Funding for Continuing Medical Education

CMAJ : Canadian Medical Association Journal = Journal De L'Association Medicale Canadienne. Jun, 2008  |  Pubmed ID: 18519914

Aquatic Virus Diversity Accessed Through Omic Techniques: a Route Map to Function

Current Opinion in Microbiology. Jun, 2008  |  Pubmed ID: 18554975

Viruses are arguably the simplest form of life yet they play a crucial role in regulating planetary processes. From shuttling genes to 'lubricating' microbial loop dynamics, viruses are integral in shaping microbial ecology. In every environment on Earth the role of viruses goes far beyond the simple infect-replicate-kill cycle. Their enormous abundance and seemingly infinite diversity provide the vital clues to the true function of viruses. New 'omic' approaches are now allowing researchers to gain extraordinary insights into virus diversity and inferred function, particularly within aquatic environments. The development of molecular markers and application of techniques including microarrays, metagenomic sequencing and proteomic analysis are now being applied to virus communities. Despite this shift towards culture-independent approaches it has proved difficult to derive useful information about infection strategies since so much of the sequence information has no database matches. Future advances will involve tools such as microarrays to help determine the functionality of unknown genes. Sequence information should be considered as a starting point for asking questions and developing hypotheses about the role of viruses. It is an exciting new era for virus ecology and when used in combination with more traditional approaches, virus genomics will give us access to their ecological function on an unprecedented scale.

Intramuscular Olanzapine in Patients with Schizophrenia: an Observational Study in an Emergency Room

Bulletin De La Société Des Sciences Médicales Du Grand-Duché De Luxembourg. 2008  |  Pubmed ID: 18561597

Between 2001 and 2005 important changes were observed in expert opinion about the clinical management of patients with schizophrenia (SCZ) and agitation requiring an IM psychotropic, with a growing interest for IM atypical antipsychotics.

Using Noise to Probe and Characterize Gene Circuits

Proceedings of the National Academy of Sciences of the United States of America. Aug, 2008  |  Pubmed ID: 18669661

Stochastic fluctuations (or "noise") in the single-cell populations of molecular species are shaped by the structure and biokinetic rates of the underlying gene circuit. The structure of the noise is summarized by its autocorrelation function. In this article, we introduce the noise regulatory vector as a generalized framework for making inferences concerning the structure and biokinetic rates of a gene circuit from its noise autocorrelation function. Although most previous studies have focused primarily on the magnitude component of the noise (given by the zero-lag autocorrelation function), our approach also considers the correlation component, which encodes additional information concerning the circuit. Theoretical analyses and simulations of various gene circuits show that the noise regulatory vector is characteristic of the composition of the circuit. Although a particular noise regulatory vector does not map uniquely to a single underlying circuit, it does suggest possible candidate circuits, while excluding others, thereby demonstrating the probative value of noise in gene circuit analysis.

Analysis of the Individual and Aggregate Genetic Contributions of Previously Identified Serine Peptidase Inhibitor Kazal Type 5 (SPINK5), Kallikrein-related Peptidase 7 (KLK7), and Filaggrin (FLG) Polymorphisms to Eczema Risk

The Journal of Allergy and Clinical Immunology. Sep, 2008  |  Pubmed ID: 18774391

Polymorphisms in the serine protease inhibitor gene serine peptidase inhibitor Kazal type 5 (SPINK5) and the serine protease kallikrein-related peptidase 7 gene (KLK7) appear to confer risk to eczema in some cohorts, but these findings have not been widely replicated. These genes encode proteins thought to be involved in the regulation of posttranslation processing of filaggrin (FLG), the strongest identified genetic risk factor for eczema to date.

Integrin-mediated Protein Kinase A Activation at the Leading Edge of Migrating Cells

Molecular Biology of the Cell. Nov, 2008  |  Pubmed ID: 18784251

cAMP-dependent protein kinase A (PKA) is important in processes requiring localized cell protrusion, such as cell migration and axonal path finding. Here, we used a membrane-targeted PKA biosensor to reveal activation of PKA at the leading edge of migrating cells. Previous studies show that PKA activity promotes protrusion and efficient cell migration. In live migrating cells, membrane-associated PKA activity was highest at the leading edge and required ligation of integrins such as alpha4beta1 or alpha5beta1 and an intact actin cytoskeleton. alpha4 integrins are type I PKA-specific A-kinase anchoring proteins, and we now find that type I PKA is important for localization of alpha4beta1 integrin-mediated PKA activation at the leading edge. Accumulation of 3' phosphorylated phosphoinositides [PtdIns(3,4,5)P(3)] products of phosphatidylinositol 3-kinase (PI3-kinase) is an early event in establishing the directionality of migration; however, polarized PKA activation did not require PI3-kinase activity. Conversely, inhibition of PKA blocked accumulation of a PtdIns(3,4,5)P(3)-binding protein, the AKT-pleckstrin homology (PH) domain, at the leading edge; hence, PKA is involved in maintaining cell polarity during migration. In sum, we have visualized compartment-specific PKA activation in migrating cells and used it to reveal that adhesion-mediated localized activation of PKA is an early step in directional cell migration.

Dynamic Visualization of Signaling Activities in Living Cells

Science Signaling. 2008  |  Pubmed ID: 18799423

The complexity and specificity of many forms of signal transduction are widely suspected to require spatial microcompartmentation and dynamic modulation of the activities of protein kinases, phosphatases, and second messengers. However, traditional methodologies for detecting signaling events, such as activation of kinases and second-messenger production and degradation, are limited in their spatiotemporal resolution and do not allow one to follow these events within the live-cell context. To achieve dynamic tracking of signaling activities in living cells, we have engineered genetically encoded fluorescent reporters for protein kinases and second messengers, such as cyclic adenosine monophosphate (cAMP) and phosphoinositides. Their development and specific examples of their application are discussed. In addition, a live-cell, high-throughput screening method has been developed for identification of new modulators that affect the dynamic activity of kinases and second messengers. Together, these reporters have the potential to provide important spatiotemporal information about the circuitry governing specific signaling events in living cells.

The "Cheshire Cat" Escape Strategy of the Coccolithophore Emiliania Huxleyi in Response to Viral Infection

Proceedings of the National Academy of Sciences of the United States of America. Oct, 2008  |  Pubmed ID: 18824682

The coccolithophore Emiliania huxleyi is one of the most successful eukaryotes in modern oceans. The two phases in its haplodiploid life cycle exhibit radically different phenotypes. The diploid calcified phase forms extensive blooms, which profoundly impact global biogeochemical equilibria. By contrast, the ecological role of the noncalcified haploid phase has been completely overlooked. Giant phycodnaviruses (Emiliania huxleyi viruses, EhVs) have been shown to infect and lyse diploid-phase cells and to be heavily implicated in the regulation of populations and the termination of blooms. Here, we demonstrate that the haploid phase of E. huxleyi is unrecognizable and therefore resistant to EhVs that kill the diploid phase. We further show that exposure of diploid E. huxleyi to EhVs induces transition to the haploid phase. Thus we have clearly demonstrated a drastic difference in viral susceptibility between life cycle stages with different ploidy levels in a unicellular eukaryote. Resistance of the haploid phase of E. huxleyi provides an escape mechanism that involves separation of meiosis from sexual fusion in time, thus ensuring that genes of dominant diploid clones are passed on to the next generation in a virus-free environment. These "Cheshire Cat" ecological dynamics release host evolution from pathogen pressure and thus can be seen as an opposite force to a classic "Red Queen" coevolutionary arms race. In E. huxleyi, this phenomenon can account for the fact that the selective balance is tilted toward the boom-and-bust scenario of optimization of both growth rates of calcifying E. huxleyi cells and infectivity of EhVs.

Structure and Stability of Isotropic States of Hard Platelet Fluids

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Oct, 2008  |  Pubmed ID: 18999406

We study the thermodynamics and the pair structure of hard, infinitely thin, circular platelets in the isotropic phase. Monte Carlo simulation results indicate a rich spatial structure of the spherical expansion components of the direct correlation function, including nonmonotonical variation of some of the components with density. Integral equation theory is shown to reproduce the main features observed in simulations. The hypernetted chain closure, as well as its extended versions that include the bridge function up to second and third order in density, perform better than both the Percus-Yevick closure and Verlet bridge function approximation. Using a recent fundamental measure density functional theory, an analytic expression for the direct correlation function is obtained as the sum of the Mayer bond and a term proportional to the density and the intersection length of two platelets. This is shown to give a reasonable estimate of the structure found in simulations, but to fail to capture the nonmonotonic variation with density. We also carry out a density functional stability analysis of the isotropic phase with respect to nematic ordering and show that the limiting density is consistent with that where the Kerr coefficient vanishes. As a reference system, we compare to simulation results for hard oblate spheroids with small, but nonzero elongations, demonstrating that the case of vanishingly thin platelets is approached smoothly.

The Discovery of GSK221149A: a Potent and Selective Oxytocin Antagonist

Bioorganic & Medicinal Chemistry Letters. Jan, 2008  |  Pubmed ID: 18032036

Optimisation of a series of oxazole diketopiperazines has led to the discovery of a very potent and selective oxytocin antagonist GSK221149A. GSK221149A has been shown to inhibit oxytocin-induced uterine contractions in the anaesthetised rat.

Negative Energy Balance Increases Periprandial Ghrelin and Growth Hormone Concentrations in Lactating Dairy Cows

Domestic Animal Endocrinology. Feb, 2008  |  Pubmed ID: 17467225

The reported effects of feeding on growth hormone (GH) secretion in ruminants have been inconsistent, and are likely influenced by energy status of animals. High-producing dairy cows in early lactation and late lactation were used to assess the effects of energy balance on temporal variation of plasma metabolites and hormones. Cows were fed a single diet once daily, and feed was withdrawn for 90 min prior to feeding. Beginning at the time of feed withdrawal, plasma samples were collected via jugular catheters hourly for 24h. Concentrations of non-esterified fatty acids and GH were measured for all samples, while insulin, glucose, and acylated (active) ghrelin were quantified for four sample times around feeding. As expected, calculated energy balance was significantly lower in early lactation than late lactation cows (-43.5 MJ retained/day versus 7.2 MJ retained/day). Following the primary meal of the day, a GH surge was observed in early lactation but not in late lactation cows. This difference was not explained by temporal patterns in non-esterified fatty acid, insulin, or glucose concentrations. However, a preprandial ghrelin surge was observed in early lactation only, suggesting that ghrelin was responsible for the prandial GH surge in this group. Results of a stepwise regression statistical analysis showed that both preprandial ghrelin concentration and energy balance were significant predictors of prandial GH increase over baseline. Adaptations to negative energy balance in lactating dairy cattle likely include enhanced ghrelin secretion and greater GH response to ghrelin.

Efflux of Hydraulically Lifted Water from Mycorrhizal Fungal Hyphae During Imposed Drought

Plant Signaling & Behavior. Jan, 2008  |  Pubmed ID: 19704776

Apart from improving plant and soil water status during drought, it has been suggested that hydraulic lift (HL) could enhance plant nutrient capture through the flow of mineral nutrients directly from the soil to plant roots, or by maintaining the functioning of mycorrhizal fungi. We evaluated the extent to which the diel cycle of water availability created by HL covaries with the efflux of HL water from the tips of extramatrical (external) mycorrhizal hyphae, and the possible effects on biogeochemical processes. Phenotypic mycorrhizal fungal variables, such as total and live hyphal lengths, were positively correlated with HL efflux from hyphae, soil water potential (dawn), and plant response variables (foliar (15)N). The efflux of HL water from hyphae was also correlated with bacterial abundance and soil enzyme activity (P), and the moistening of soil organic matter. Such findings indicate that the efflux of HL water from the external mycorrhizal mycelia may be a complementary explanation for plant nutrient acquisition and survival during drought.

Therapeutic Effect of Hyperbaric Oxygen in Psoriasis Vulgaris: Two Case Reports and a Review of the Literature

Journal of Medical Case Reports. 2009  |  Pubmed ID: 19830133

Psoriasis is an inflammatory and immunological cutaneous disease. The high morbidity in patients with psoriasis results from severe clinical manifestations and/or adverse effects of treatment. The Undersea and Hyperbaric Medical Society and Federal Medicare and Medicaid Services have approved the use of hyperbaric oxygen (HBO(2)) for more than 15 indications, including wound healing, infections and late effects of radiation, which are largely unresponsive to conventional treatments. Accumulated data show that HBO(2) has anti-inflammatory effects and other positive influences on the immune system, making it a rational treatment in the management of psoriasis plaques and arthritis.

Association Study of 21 Circadian Genes with Bipolar I Disorder, Schizoaffective Disorder, and Schizophrenia

Bipolar Disorders. Nov, 2009  |  Pubmed ID: 19839995

Published studies suggest associations between circadian gene polymorphisms and bipolar I disorder (BPI), as well as schizoaffective disorder (SZA) and schizophrenia (SZ). The results are plausible, based on prior studies of circadian abnormalities. As replications have not been attempted uniformly, we evaluated representative, common polymorphisms in all three disorders.

The Psychiatric Emergency Research Collaboration-01: Methods and Results

General Hospital Psychiatry. Nov-Dec, 2009  |  Pubmed ID: 19892209

To describe the Psychiatric Emergency Research Collaboration (PERC), the methods used to create a structured chart review tool and the results of our multicenter study.

Suicidal Ideation and Depressive Symptoms Among Bipolar Patients As Predictors of the Health and Well-being of Caregivers

Bipolar Disorders. Dec, 2009  |  Pubmed ID: 19922556

Few studies have addressed the physical and mental health effects of caring for a family member with bipolar disorder. This study examined whether caregivers' health is associated with changes in suicidal ideation and depressive symptoms among bipolar patients observed over one year.

Elongated Polyproline Motifs Facilitate Enamel Evolution Through Matrix Subunit Compaction

PLoS Biology. Dec, 2009  |  Pubmed ID: 20027208

Vertebrate body designs rely on hydroxyapatite as the principal mineral component of relatively light-weight, articulated endoskeletons and sophisticated tooth-bearing jaws, facilitating rapid movement and efficient predation. Biological mineralization and skeletal growth are frequently accomplished through proteins containing polyproline repeat elements. Through their well-defined yet mobile and flexible structure polyproline-rich proteins control mineral shape and contribute many other biological functions including Alzheimer's amyloid aggregation and prolamine plant storage. In the present study we have hypothesized that polyproline repeat proteins exert their control over biological events such as mineral growth, plaque aggregation, or viscous adhesion by altering the length of their central repeat domain, resulting in dramatic changes in supramolecular assembly dimensions. In order to test our hypothesis, we have used the vertebrate mineralization protein amelogenin as an exemplar and determined the biological effect of the four-fold increased polyproline tandem repeat length in the amphibian/mammalian transition. To study the effect of polyproline repeat length on matrix assembly, protein structure, and apatite crystal growth, we have measured supramolecular assembly dimensions in various vertebrates using atomic force microscopy, tested the effect of protein assemblies on crystal growth by electron microscopy, generated a transgenic mouse model to examine the effect of an abbreviated polyproline sequence on crystal growth, and determined the structure of polyproline repeat elements using 3D NMR. Our study shows that an increase in PXX/PXQ tandem repeat motif length results (i) in a compaction of protein matrix subunit dimensions, (ii) reduced conformational variability, (iii) an increase in polyproline II helices, and (iv) promotion of apatite crystal length. Together, these findings establish a direct relationship between polyproline tandem repeat fragment assemblies and the evolution and the design of vertebrate mineralized tissue microstructures. Our findings reveal that in the greater context of chordate evolution, the biological control of apatite growth by polyproline-based matrix assemblies provides a molecular basis for the evolution of the vertebrate body plan.

Noise in Biological Circuits

Wiley Interdisciplinary Reviews. Nanomedicine and Nanobiotechnology. Mar-Apr, 2009  |  Pubmed ID: 20049792

Noise biology focuses on the sources, processing, and biological consequences of the inherent stochastic fluctuations in molecular transitions or interactions that control cellular behavior. These fluctuations are especially pronounced in small systems where the magnitudes of the fluctuations approach or exceed the mean value of the molecular population. Noise biology is an essential component of nanomedicine where the communication of information is across a boundary that separates small synthetic and biological systems that are bound by their size to reside in environments of large fluctuations. Here we review the fundamentals of the computational, analytical, and experimental approaches to noise biology. We review results that show that the competition between the benefits of low noise and those of low population has resulted in the evolution of genetic system architectures that produce an uneven distribution of stochasticity across the molecular components of cells and, in some cases, use noise to drive biological function. We review the exact and approximate approaches to gene circuit noise analysis and simulation, and review many of the key experimental results obtained using flow cytometry and time-lapse fluorescent microscopy. In addition, we consider the probative value of noise with a discussion of using measured noise properties to elucidate the structure and function of the underlying gene circuit. We conclude with a discussion of the frontiers of and significant future challenges for noise biology.

Acute Nonpsychotic Mania: First Episode

CNS Spectrums. Nov, 2009  |  Pubmed ID: 20173693

Increasing Demands on Limited Water Resources: Consequences for Two Endangered Plants in Amargosa Valley, USA

American Journal of Botany. Mar, 2009  |  Pubmed ID: 21628218

Recent population expansion throughout the Southwest United States has created an unprecedented demand for already limited water resources, which may have severe consequences on the persistence of some species. Two such species are the federally protected Nitrophila mohavensis (Chenopodiaceae) and Grindelia fraxino-pratensis (Asteraceae) found in Amargosa Valley, one valley east of Death Valley, California. Because both species are federally protected, no plant material could be harvested for analysis. We therefore used a chamber system to collect transpired water for isotopic analysis. After a correction for isotopic enrichment during transpiration, δ(18)O values of plant xylem water were significantly different between N. mohavensis and G. fraxino-pratensis throughout the study. Using a multisource mixing model, we found that both N. mohavensis and G. fraxino-pratensis used soil moisture near the soil surface in early spring when surface water was present. However, during the dry summer months, G. fraxino-pratensis tracked soil moisture to deeper depths, whereas N. mohavensis continued to use soil moisture near the soil surface. These results indicate that pumping groundwater and subsequently lowering the water table may directly prevent G. fraxino-pratensis from accessing water, whereas these same conditions may indirectly affect N. mohavensis by reducing surface soil moisture and thus its ability to access water.

The Functional Impact of Subsyndromal Depressive Symptoms in Bipolar Disorder: Data from STEP-BD

Journal of Affective Disorders. Apr, 2009  |  Pubmed ID: 18708263

This report describes baseline characteristics and functional outcomes of subjects who have prospectively observed subsyndromal symptoms after a major depressive episode (MDE).

Horizontal Gene Transfer of an Entire Metabolic Pathway Between a Eukaryotic Alga and Its DNA Virus

Genome Research. Aug, 2009  |  Pubmed ID: 19451591

Interactions between viruses and phytoplankton, the main primary producers in the oceans, affect global biogeochemical cycles and climate. Recent studies are increasingly revealing possible cases of gene transfers between cyanobacteria and phages, which might have played significant roles in the evolution of cyanobacteria/phage systems. However, little has been documented about the occurrence of horizontal gene transfer in eukaryotic phytoplankton/virus systems. Here we report phylogenetic evidence for the transfer of seven genes involved in the sphingolipid biosynthesis pathway between the cosmopolitan eukaryotic microalga Emiliania huxleyi and its large DNA virus EhV. PCR assays indicate that these genes are prevalent in E. huxleyi and EhV strains isolated from different geographic locations. Patterns of protein and gene sequence conservation support that these genes are functional in both E. huxleyi and EhV. This is the first clear case of horizontal gene transfer of multiple functionally linked enzymes in a eukaryotic phytoplankton-virus system. We examine arguments for the possible direction of the gene transfer. The virus-to-host direction suggests the existence of ancient viruses that controlled the complex metabolic pathway in order to infect primitive eukaryotic cells. In contrast, the host-to-virus direction suggests that the serial acquisition of genes involved in the same metabolic pathway might have been a strategy for the ancestor of EhVs to stay ahead of their closest relatives in the great evolutionary race for survival.

The CAMP-dependent Protein Kinase Inhibitor H-89 Attenuates the Bioluminescence Signal Produced by Renilla Luciferase

PloS One. 2009  |  Pubmed ID: 19461967

Investigations into the regulation and functional roles of kinases such as cAMP-dependent protein kinase (PKA) increasingly rely on cellular assays. Currently, there are a number of bioluminescence-based assays, for example reporter gene assays, that allow the study of the regulation, activity, and functional effects of PKA in the cellular context. Additionally there are continuing efforts to engineer improved biosensors that are capable of detecting real-time PKA signaling dynamics in cells. These cell-based assays are often utilized to test the involvement of PKA-dependent processes by using H-89, a reversible competitive inhibitor of PKA.

The Relationships of Impulsivity and Cardiovascular Responses: the Role of Gender and Task Type

International Journal of Psychophysiology : Official Journal of the International Organization of Psychophysiology. Sep, 2009  |  Pubmed ID: 19486914

The present study was conducted to assess the relationships of impulsivity with both baseline cardiovascular levels and reactivity during two laboratory stressors in both female and male young adults. Heart rate (HR), blood pressure (BP), and heart rate variability (HRV) were measured at rest and during a reaction time and speech task in one hundred and one undergraduate students. Impulsivity was measured using the Barratt Impulsiveness Scale-11 and Block's Ego-Undercontrol Scale. Males and females responded similarly to both laboratory tasks and also did not differ on the impulsivity scales. For males, higher scores on impulsivity were associated with higher systolic BP levels at rest but decreased systolic BP and HR reactivity during the preparation of the speech task; females showed no relationships of resting cardiovascular levels with impulsivity, but more impulsive females did show decreased HR response during speech preparation. No significant relationships were found between impulsivity and either HRV levels or reactivity. It is speculated that tasks involving a degree of planning may be important to find relationships between impulsivity and cardiovascular reactivity, especially in males.

Interaction Between Clopidogrel and Proton Pump Inhibitors

CMAJ : Canadian Medical Association Journal = Journal De L'Association Medicale Canadienne. Jun, 2009  |  Pubmed ID: 19506284

Control of Eating by Hepatic Oxidation of Fatty Acids. A Note of Caution

Appetite. Oct, 2009  |  Pubmed ID: 19540287

Langhans [Langhans, W. (2008). Fatty acid oxidation in the energostatic control of eating-a new idea. Appetite, 51, 446-451] suggested that the liver might not be involved in the control of eating by fatty acid oxidation (FAO). However, the evidence presented against the role of the liver is weak at best, and may be incorrect. Inhibition of FAO by metabolic inhibitors generally stimulates eating, but in recent experiments from the author's laboratory, inhibition of beta-oxidation failed to stimulate eating when FAO was elevated by fasting or adrenoceptor agonists. The author used these experiments as evidence that the liver is not involved in the control of eating by FAO, but this conclusion is open to question because mercaptoacetate, the agent used to inhibit FAO, stimulates anorexia through adrenergic mechanisms. The evidence supporting a role for hepatic FAO in metabolic regulation of food intake remains strong.

Hypertensive Crisis During Radiofrequency Ablation of the Adrenal Gland

Journal of Vascular and Interventional Radiology : JVIR. Jul, 2009  |  Pubmed ID: 19555894

Haloperidol Plus Promethazine for Psychosis-induced Aggression

Cochrane Database of Systematic Reviews (Online). 2009  |  Pubmed ID: 19588366

Health services often manage agitated or violent people, and for emergency psychiatric services such behaviour is particularly prevalent (10%). The drugs used in this situation should ensure that the person swiftly and safely regains composure.

Host-virus Shift of the Sphingolipid Pathway Along an Emiliania Huxleyi Bloom: Survival of the Fattest

Environmental Microbiology. Nov, 2009  |  Pubmed ID: 19638172

The interactions between viruses and phytoplankton play a key role in shaping the ecological and evolutionary dynamics of oceanic ecosystems. One of the most fascinating examples of horizontal gene transfer between a eukaryotic host and its virus is a de novo sphingolipid biosynthesis pathway (SBP) found in the genomes of both Emiliania huxleyi and its coccolithovirus EhV-86. Here, we focus on a natural E. huxleyi/coccolithovirus system off the coast of Norway and investigate the dynamics of host and virus homologous gene expression for two of the most important sphingolipid biosynthesis enzymes, serine palmitoyl transferase (SPT) and dihydroceramide desaturase (DCD). Transcriptional dynamics display three defined stages along E. huxleyi bloom formation and decline, with the coccolithovirus transcripts taking over and controlling the SBP in stages 2 and 3. The observed patterns fit the hypothesis according to which viral sphingolipids are involved in the timing and physical processes of virion release from the host cells. This study provides a unique insight into the transcriptional interplay of homologous metabolic pathways between virus and host during temporal progression of oceanic E. huxleyi blooms.

From Small Hosts Come Big Viruses: the Complete Genome of a Second Ostreococcus Tauri Virus, OtV-1

Environmental Microbiology. Nov, 2009  |  Pubmed ID: 19650882

Ostreococcus tauri virus (OtV-1) is a large double-stranded DNA virus and a prospective member of the family Phycodnaviridae, genus Prasinovirus. OtV-1 infects the unicellular marine green alga O. tauri, the smallest known free-living eukaryote. Here we present the 191 761 base pair genome sequence of OtV-1, which has 232 putative protein-encoding and 4 tRNA-encoding genes. Approximately 31% of the viral gene products exhibit a similarity to proteins of known functions in public databases. These include a variety of unexpected genes, for example, a PhoH-like protein, a N-myristoyltransferase, a 3-dehydroquinate synthase, a number of glycosyltransferases and methyltransferases, a prolyl 4-hydroxylase, 6-phosphofructokinase and a total of 8 capsid proteins. A total of 11 predicted genes share homology with genes found in the Ostreococcus host genome. In addition, an intein was identified in the DNA polymerase gene of OtV-1. This is the first report of an intein in the genome of a virus that infects O. tauri. Fifteen core genes common to nuclear-cytoplasmic large dsDNA virus (NCLDV) genomes were identified in the OtV-1 genome. This new sequence data may help to redefine the classification of the core genes of these viruses and shed new light on their evolutionary history.

Are Female Psychiatry Residents Better to Propose in Emergency a Voluntary Hospitalization?

The Psychiatric Quarterly. Dec, 2009  |  Pubmed ID: 19680811

This study analyses assessment, intervention and admission decisions made by emergency psychiatry residents, to determine whether these differ depending on the gender of the resident. Data from all patients presenting to a psychiatric emergency room were collected prospectively for a 3 months period as part of a local quality check project. A questionnaire was used to collect patient demographic data, diagnosis, treatment decisions and the personal and professional characteristics of the residents who performed the assessments. During the 3 months of the study period we obtained data on all 251 emergency assessments carried out by all six residents working in the service. These were 3 female and 3 male 3rd year residents in psychiatry. There was no difference between male and female residents concerning ICD-10 diagnostic assessment, adherence to local hospitalization criteria guidelines, psychotherapeutical and pharmacological treatments administered. A similar distribution between male and female residents was found for diagnoses. No difference was found in the rate of hospitalization decisions between male and female residents. However, surprisingly, there were more voluntary hospitalizations by the women residents (P = 0.035; χ2 = 4.443) and more involuntary admissions by the men residents (P = 0.005; χ2 = 7.643). There was no correlation between the gender of the patient and the assessment or hospitalization decision of either male or female residents. Although this study has methodological limitations, it suggests that female emergency psychiatry residents are more likely to propose voluntary hospitalizations.

Bidirectional Water Flows Through the Soil-fungal-plant Mycorrhizal Continuum

The New Phytologist. 2009  |  Pubmed ID: 19338631

Topographic Position Modulates the Mycorrhizal Response of Oak Trees to Interannual Rainfall Variability

Ecology. Mar, 2009  |  Pubmed ID: 19341136

California coast live oak (Quercus agrifolia) forms tripartite symbiotic associations with arbuscular (AMF) and ectomycorrhizal (EMF) fungi. We selected oak individuals differing in topographic position and depth to groundwater (mesic valley vs. xeric hill sites) to investigate changes of tree mycorrhizal status in response to interannual rainfall variability. EMF root colonization, as well as hyphal abundance and viability in upper rhizosphere soil (0-30 cm), were negatively affected by severe multi-year drought, although not to the same extent in each topographic location. Oak trees growing in hill sites showed EMF colonization levels <1% in upper roots during drought. By contrast, oaks in valley sites maintained much higher EMF colonization (>19%) in upper roots during drought. EMF root colonization increased sharply at both topographic positions during the ensuing wet year (78% in valley, 49% in hill), which indicates that the mycorrhizal status of roots in upper rhizosphere soil is highly responsive to interannual rainfall variability. Across sites and years, percentage EMF colonization and soil hyphal density and viability were strongly positively correlated with soil moisture potential, but percentage AMF root colonization was not. Interestingly, changes in percentage EMF root colonization and density of viable hyphae between a wet and a dry year were proportionally much greater in xeric hill sites than in mesic valley sites. The mycorrhizal status of oak trees was particularly responsive to changes in soil moisture at the hill sites, where roots in upper rhizosphere soil shifted from almost exclusively AMF during severe drought to predominantly EMF during the ensuing wet year. By contrast, the mycorrhizal status of oaks in the valley sites was less strongly coupled to current meteorological conditions, as roots in upper soil layers remained predominantly EMF during both a dry and a wet year. Canopy shading and hydraulic lift by oaks in valley sites likely contributed to maintain the integrity and viability of EMF roots and extraradical hyphae in upper rhizosphere soil during extended drought. Our results suggest that oak woodlands in water-limited ecosystems may become increasingly reliant on the AMF symbiosis under future climate change scenarios for the U.S. southwest and other world regions.

The Activation-induced Cytidine Deaminase (AID) Efficiently Targets DNA in Nucleosomes but Only During Transcription

The Journal of Experimental Medicine. May, 2009  |  Pubmed ID: 19380635

The activation-induced cytidine deaminase (AID) initiates somatic hypermutation, class-switch recombination, and gene conversion of immunoglobulin genes. In vitro, AID has been shown to target single-stranded DNA, relaxed double-stranded DNA, when transcribed, or supercoiled DNA. To simulate the in vivo situation more closely, we have introduced two copies of a nucleosome positioning sequence, MP2, into a supercoiled AID target plasmid to determine where around the positioned nucleosomes (in the vicinity of an ampicillin resistance gene) cytidine deaminations occur in the absence or presence of transcription. We found that without transcription nucleosomes prevented cytidine deamination by AID. However, with transcription AID readily accessed DNA in nucleosomes on both DNA strands. The experiments also showed that AID targeting any DNA molecule was the limiting step, and they support the conclusion that once targeted to DNA, AID acts processively in naked DNA and DNA organized within transcribed nucleosomes.

Tumour-associated Tenascin-C Isoforms Promote Breast Cancer Cell Invasion and Growth by Matrix Metalloproteinase-dependent and Independent Mechanisms

Breast Cancer Research : BCR. 2009  |  Pubmed ID: 19405959

The stromal microenvironment has a profound influence on tumour cell behaviour. In tumours, the extracellular matrix (ECM) composition differs from normal tissue and allows novel interactions to influence tumour cell function. The ECM protein tenascin-C (TNC) is frequently up-regulated in breast cancer and we have previously identified two novel isoforms - one containing exon 16 (TNC-16) and one containing exons 14 plus 16 (TNC-14/16).

Environmental Sensor Networks in Ecological Research

The New Phytologist. 2009  |  Pubmed ID: 19422546

Environmental sensor networks offer a powerful combination of distributed sensing capacity, real-time data visualization and analysis, and integration with adjacent networks and remote sensing data streams. These advances have become a reality as a combined result of the continuing miniaturization of electronics, the availability of large data storage and computational capacity, and the pervasive connectivity of the Internet. Environmental sensor networks have been established and large new networks are planned for monitoring multiple habitats at many different scales. Projects range in spatial scale from continental systems designed to measure global change and environmental stability to those involved with the monitoring of only a few meters of forest edge in fragmented landscapes. Temporal measurements have ranged from the evaluation of sunfleck dynamics at scales of seconds, to daily CO2 fluxes, to decadal shifts in temperatures. Above-ground sensor systems are partnered with subsurface soil measurement networks for physical and biological activity, together with aquatic and riparian sensor networks to measure groundwater fluxes and nutrient dynamics. More recently, complex sensors, such as networked digital cameras and microphones, as well as newly emerging sensors, are being integrated into sensor networks for hierarchical methods of sensing that promise a further understanding of our ecological systems by revealing previously unobservable phenomena.

Evidence of Old Carbon Used to Grow New Fine Roots in a Tropical Forest

The New Phytologist. 2009  |  Pubmed ID: 19434807

In this study, we explore how a hurricane disturbance influenced carbon allocation for the production of new fine roots. Before and after a hurricane, we measured the age of carbon (time since fixation from the atmosphere) in fine root structural tissues using natural abundance radiocarbon (14C) measured by accelerator mass spectrometry. Roots were sampled from five seasonally dry tropical forests ranging in age from 6 yr to a mature forest. Structural carbon in combined live + dead roots picked from soil cores sampled 1 month before the hurricane had mean ages ranging from 4 to 11 yr, whereas live roots alone had ages of 1-2 yr. Structural carbon in new live fine roots produced over a period lasting from 3 wk before the hurricane to 2 months after the event had mean ages of between 2 and 10 yr. Contrary to expectations, our results showed that plants allocate long-lived storage carbon pools to the production of new fine roots after canopy defoliation and root mortality. The age of the carbon allocated for new roots increased with forest age and forest above-ground biomass, suggesting an adaptation of plants to survive and recover from severe disturbances.

In Vivo Saturation Binding of GABA-A Receptor Ligands to Estimate Receptor Occupancy Using Liquid Chromatography/tandem Mass Spectrometry

Biopharmaceutics & Drug Disposition. Jan, 2009  |  Pubmed ID: 19152227

Typically, the dose-occupancy curves for GABA-A receptor ligands are determined using in vivo binding of [3H]flumazenil. This study describes in vivo binding experiments without the use of tracer ligands. Bound and free fractions were measured directly using a highly sensitive LC/MS/MS detection method after in vivo administration of the GABA-A ligands zolpidem, (RS)-zopiclone, L-838417 and flumazenil, to demonstrate affinity and saturation of the filter-retained, membrane-bound fraction. The in vivo binding of flumazenil and L-838417 both saturated around 200 nM, at a similar level to the specific binding of (S)-zopiclone after doses of the racemic zopiclone, using (R)-zopiclone to estimate non-specific binding. This saturable component represented an estimate of benzodiazepine binding sites available on GABA-A receptors in vivo (200 nM). Dose-occupancy curves were constructed to estimate the dose required to achieve 50% occupancy and matched estimates obtained with tracer methods. In contrast to tracer methods, this method is uniquely suitable to the demonstration of stereoselective binding of the (S)-isomer in vivo after doses of racemic zopiclone. These results demonstrate that the LC/MS/MS measurements of total drug concentrations typically used in early drug development can be adapted to provide information about receptor occupancy in vivo.

Microvolume Spectrophotometric and Fluorometric Determination of Protein Concentration

Current Protocols in Protein Science / Editorial Board, John E. Coligan ... [et Al.]. Feb, 2009  |  Pubmed ID: 19235138

Methods for determining protein concentration that use progressively smaller amounts of material are continually being developed. A new way of minimizing the amount of sample used for spectroscopic analysis is providing more opportunities for greater quality control. Traditional spectrophotometric and fluorometric methods for determination of protein concentrations have long required placing samples into containment devices such as cuvettes or capillaries. A microsample retention system is changing that paradigm by using natural surface tension properties to capture and hold microvolume samples in place during measurement without traditional containment devices. The advantage of such a system is to dramatically reduce the amount of sample required (1 to 2 microl) while greatly increasing the dynamic range of protein concentrations that can be measured. Modifications to classic protein concentration determination protocols are presented to provide a microvolume alternative to traditional cuvette-based methods.

Improved Simulations of Lattice Peptide Adsorption

Physical Chemistry Chemical Physics : PCCP. Mar, 2009  |  Pubmed ID: 19280015

We propose several improvements to the Monte Carlo simulation techniques for lattice peptide adsorption on surfaces. Firstly, we examine the implementation of "pull" moves and discuss the most efficient way of selecting them. Secondly, we explicitly show how Wang-Landau sampling may be used to calculate the appropriate density of states for a peptide chain in contact with a single surface, and how the information from such a simulation may be used to calculate results for slit geometry with a range of wall separations. Lastly, we consider further possible modifications of the simulation method and its application to adsorption on structured and patterned surfaces.

Linkage Disequilibrium Mapping of the Chromosome 6q21-22.31 Bipolar I Disorder Susceptibility Locus

American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics : the Official Publication of the International Society of Psychiatric Genetics. Jan, 2010  |  Pubmed ID: 19308960

We previously reported genome-wide significant evidence for linkage between chromosome 6q and bipolar I disorder (BPI) by performing a meta-analysis of original genotype data from 11 genome scan linkage studies. We now present follow-up linkage disequilibrium mapping of the linked region utilizing 3,047 single nucleotide polymorphism (SNP) markers in a case-control sample (N = 530 cases, 534 controls) and family-based sample (N = 256 nuclear families, 1,301 individuals). The strongest single SNP result (rs6938431, P = 6.72 x 10(-5)) was observed in the case-control sample, near the solute carrier family 22, member 16 gene (SLC22A16). In a replication study, we genotyped 151 SNPs in an independent sample (N = 622 cases, 1,181 controls) and observed further evidence of association between variants at SLC22A16 and BPI. Although consistent evidence of association with any single variant was not seen across samples, SNP-wise and gene-based test results in the three samples provided convergent evidence for association with SLC22A16, a carnitine transporter, implicating this gene as a novel candidate for BPI risk. Further studies in larger samples are warranted to clarify which, if any, genes in the 6q region confer risk for bipolar disorder.

Looking Deeper into the Soil: Biophysical Controls and Seasonal Lags of Soil CO2 Production and Efflux

Ecological Applications : a Publication of the Ecological Society of America. Sep, 2010  |  Pubmed ID: 20945760

We seek to understand how biophysical factors such as soil temperature (Ts), soil moisture (theta), and gross primary production (GPP) influence CO2 fluxes across terrestrial ecosystems. Recent advancements in automated measurements and remote-sensing approaches have provided time series in which lags and relationships among variables can be explored. The purpose of this study is to present new applications of continuous measurements of soil CO2 efflux (F0) and soil CO2 concentrations measurements. Here we explore how variation in Ts, theta, and GPP (derived from NASA's moderate-resolution imaging spectroradiometer [MODIS]) influence F0 and soil CO2 production (Ps). We focused on seasonal variation and used continuous measurements at a daily timescale across four vegetation types at 13 study sites to quantify: (1) differences in seasonal lags between soil CO2 fluxes and Ts, theta, and GPP and (2) interactions and relationships between CO2 fluxes with Ts, theta, and GPP. Mean annual Ts did not explain annual F0 and Ps among vegetation types, but GPP explained 73% and 30% of the variation, respectively. We found evidence that lags between soil CO2 fluxes and Ts or GPP provide insights into the role of plant phenology and information relevant about possible timing of controls of autotrophic and heterotrophic processes. The influences of biophysical factors that regulate daily F0 and Ps are different among vegetation types, but GPP is a dominant variable for explaining soil CO2 fluxes. The emergence of long-term automated soil CO2 flux measurement networks provides a unique opportunity for extended investigations into F0 and Ps processes in the near future.

A Genome-wide Association Study Identifies New Psoriasis Susceptibility Loci and an Interaction Between HLA-C and ERAP1

Nature Genetics. Nov, 2010  |  Pubmed ID: 20953190

To identify new susceptibility loci for psoriasis, we undertook a genome-wide association study of 594,224 SNPs in 2,622 individuals with psoriasis and 5,667 controls. We identified associations at eight previously unreported genomic loci. Seven loci harbored genes with recognized immune functions (IL28RA, REL, IFIH1, ERAP1, TRAF3IP2, NFKBIA and TYK2). These associations were replicated in 9,079 European samples (six loci with a combined P < 5 × 10⁻⁸ and two loci with a combined P < 5 × 10⁻⁷). We also report compelling evidence for an interaction between the HLA-C and ERAP1 loci (combined P = 6.95 × 10⁻⁶). ERAP1 plays an important role in MHC class I peptide processing. ERAP1 variants only influenced psoriasis susceptibility in individuals carrying the HLA-C risk allele. Our findings implicate pathways that integrate epidermal barrier dysfunction with innate and adaptive immune dysregulation in psoriasis pathogenesis.

Giant Virus with a Remarkable Complement of Genes Infects Marine Zooplankton

Proceedings of the National Academy of Sciences of the United States of America. Nov, 2010  |  Pubmed ID: 20974979

As major consumers of heterotrophic bacteria and phytoplankton, microzooplankton are a critical link in aquatic foodwebs. Here, we show that a major marine microflagellate grazer is infected by a giant virus, Cafeteria roenbergensis virus (CroV), which has the largest genome of any described marine virus (≈730 kb of double-stranded DNA). The central 618-kb coding part of this AT-rich genome contains 544 predicted protein-coding genes; putative early and late promoter motifs have been detected and assigned to 191 and 72 of them, respectively, and at least 274 genes were expressed during infection. The diverse coding potential of CroV includes predicted translation factors, DNA repair enzymes such as DNA mismatch repair protein MutS and two photolyases, multiple ubiquitin pathway components, four intein elements, and 22 tRNAs. Many genes including isoleucyl-tRNA synthetase, eIF-2γ, and an Elp3-like histone acetyltransferase are usually not found in viruses. We also discovered a 38-kb genomic region of putative bacterial origin, which encodes several predicted carbohydrate metabolizing enzymes, including an entire pathway for the biosynthesis of 3-deoxy-d-manno-octulosonate, a key component of the outer membrane in Gram-negative bacteria. Phylogenetic analysis indicates that CroV is a nucleocytoplasmic large DNA virus, with Acanthamoeba polyphaga mimivirus as its closest relative, although less than one-third of the genes of CroV have homologs in Mimivirus. CroV is a highly complex marine virus and the only virus studied in genetic detail that infects one of the major groups of predators in the oceans.

NIH Roundtable on Opportunities to Advance Research on Neurologic and Psychiatric Emergencies

Annals of Emergency Medicine. Nov, 2010  |  Pubmed ID: 21036295

The Institute of Medicine Committee on the Future of Emergency Care in the United States Health System (2003) identified a need to enhance the research base for emergency care. As a result, a National Institutes of Health (NIH) Task Force on Research in Emergency Medicine was formed to enhance NIH support for emergency care research. Members of the NIH Task Force and academic leaders in emergency care participated in 3 Roundtable discussions to prioritize current opportunities for enhancing and conducting emergency care research. We identify key research questions essential to advancing the science of emergency care and discuss the barriers and strategies to advance research by exploring the collaboration between NIH and the emergency care community.

Jekyll and Hyde: the Role of the Microenvironment on the Progression of Cancer

The Journal of Pathology. Oct, 2010  |  Pubmed ID: 21038318

It is now recognized that the host microenvironment undergoes extensive change during the evolution and progression of cancer. This involves the generation of cancer-associated fibroblasts (CAFs), which, through release of growth factors and cytokines, lead to enhanced angiogenesis, increased tumour growth and invasion. It has also been demonstrated that CAFs may modulate the cancer stem cell (CSC) phenotype, which has therapeutic implications. The altered fibroblast phenotype also contributes to the development of an altered extracellular matrix (ECM), with synthesis of ECM isoforms rarely found in normal tissues, including tenascin-C isoforms and the fibronectin EDA isoform. There is also emerging evidence of how the tensile strength of the tumour-associated ECM may be modified and lead to altered signalling in tumour cells. The hypoxic environment of the tumour stimulates angiogenesis and also impacts on other aspects of cell signalling, including the c-met pathway and lysyl oxidase-mediated signalling, which can directly promote tumour cell invasion. The inflammatory infiltrate associated with many solid tumours also modulates tumour function, having both anti- and pro-tumour effects. All of these components of the microenvironment provide potential targets for therapeutic attack, with a number of molecules already in clinical trials. It is also becoming evident that characterizing the tumour microenvironment can provide important prognostic and predictive information about tumours, independent of the tumour cell phenotype. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The Effects of Race on Peak Oxygen Consumption and Survival in Patients with Systolic Dysfunction

Journal of Cardiac Failure. Apr, 2010  |  Pubmed ID: 20350701

The relationship of peak exercise oxygen consumption (VO(2)) to survival in black heart failure (HF) patients is not well established. We examined the effects of race on peak VO(2) values and survival in HF patients with systolic dysfunction.

Heat-health Warning Systems: a Comparison of the Predictive Capacity of Different Approaches to Identifying Dangerously Hot Days

American Journal of Public Health. Jun, 2010  |  Pubmed ID: 20395585

We compared the ability of several heat-health warning systems to predict days of heat-associated mortality using common data sets.

Associations of Sexual Risk-taking with Having Intercourse Before 15 Years in Adolescent Females in Cape Breton, Nova Scotia, Canada

Sexual Health. Jun, 2010  |  Pubmed ID: 20465987

This study was carried out to determine whether having first vaginal intercourse before 15 years of age is independently associated with sexual risk behaviours in Canadian female adolescents aged from 15 to 19 years.

Characterizing Urbanization, and Agricultural and Conservation Land-use Change in Riverside County, California, USA

Annals of the New York Academy of Sciences. May, 2010  |  Pubmed ID: 20586769

Monitoring trends in urbanization and land use related to population growth and changing social and economic conditions is an important tool for developing in land use and habitat conservation policy. We analyzed urbanization and agricultural land-use change in Riverside County, California from 1984 to 2002, comparing maps every two years on the basis of aerial photographs. Matrix analysis combined with information theory was applied to study land type conversion. Results showed that the total area of "Urban and Built-Up Land" increased the most whereas total area of "Prime Farmland" decreased most. Land-use characterized as "Grazing Land,"Farmland of Local Importance," and "Farmland of Statewide Importance" also decreased. Mean patch size also decreased for "Grazing Land,"Water Area,"Other Land," and "Prime Farmland." The diversity of land types decreased dramatically after 1992. Urbanization patterns were different among three city groups (Riverside City, Coachella Valley, and Blythe), indicating the different times for "leapfrog" development in the three areas. Furthermore, the unpredictability and change in composition of land use increased after 1996 due to intensified urbanization. If the current driving forces continue, our model projects that in 2020 the area of "Urban and Built-Up Land" may increase between 25% and 39% in comparison with 2002. Percentages of most agricultural land types are projected to decrease, especially "Farmland of Local Importance,"Prime Farmland," and "Farmland of Statewide Importance." If the county's goal is to preserve agricultural lands and natural biodiversity, while maintaining sustainable development, current land-use policies and practices should be changed. This study demonstrates new useful methods for monitoring and detection of change of land-use processes.

Does Local Adaptation to Resources Explain Genetic Differentiation Among Daphnia Populations?

Molecular Ecology. Aug, 2010  |  Pubmed ID: 20609079

Substantial genetic differentiation is frequently observed among populations of cyclically parthenogenetic zooplankton despite their high dispersal capabilities and potential for gene flow. Local adaptation has been invoked to explain population genetic differentiation despite high dispersal, but several neutral models that account for basic life history features also predict high genetic differentiation. Here, we study genetic differentiation among four populations of Daphnia pulex in east central Illinois. As with other studies of Daphnia, we demonstrate substantial population genetic differentiation despite close geographic proximity (<50 km; mean theta = 0.22). However, we explicitly tested and failed to find evidence for, the hypothesis that local adaptation to food resources occurs in these populations. Recognizing that local adaptation can occur in traits unrelated to resources, we estimated contemporary migration rates (m) and tested for admixture to evaluate the hypothesis that observed genetic differentiation is consistent with local adaptation to other untested ecological factors. Using Bayesian assignment methods, we detected migrants in three of the four study populations including substantial evidence for successful reproduction by immigrants in one pond, allowing us to reject the hypothesis that local adaptation limits gene flow for at least this population. Thus, we suggest that local adaptation does not explain genetic differentiation among these Daphnia populations and that other factors related to extinction/colonization dynamics, a long approach to equilibrium F(ST) or substantial genetic drift due to a low number of individuals hatching from the egg bank each season may explain genetic differentiation.

Water Relations of Evergreen and Drought-deciduous Trees Along a Seasonally Dry Tropical Forest Chronosequence

Oecologia. Dec, 2010  |  Pubmed ID: 20658152

Seasonally dry tropical forests (SDTF) are characterized by pronounced seasonality in rainfall, and as a result trees in these forests must endure seasonal variation in soil water availability. Furthermore, SDTF on the northern Yucatan Peninsula, Mexico, have a legacy of disturbances, thereby creating a patchy mosaic of different seral stages undergoing secondary succession. We examined the water status of six canopy tree species, representing contrasting leaf phenology (evergreen vs. drought-deciduous) at three seral stages along a fire chronosequence in order to better understand strategies that trees use to overcome seasonal water limitations. The early-seral forest was characterized by high soil water evaporation and low soil moisture, and consequently early-seral trees exhibited lower midday bulk leaf water potentials (Ψ(L)) relative to late-seral trees (-1.01 ± 0.14 and -0.54 ± 0.07 MPa, respectively). Although Ψ(L) did not differ between evergreen and drought-deciduous trees, results from stable isotope analyses indicated different strategies to overcome seasonal water limitations. Differences were especially pronounced in the early-seral stage where evergreen trees had significantly lower xylem water δ(18)O values relative to drought-deciduous trees (-2.6 ± 0.5 and 0.3 ± 0.6‰, respectively), indicating evergreen species used deeper sources of water. In contrast, drought-deciduous trees showed greater enrichment of foliar (18)O (∆(18)O(l)) and (13)C, suggesting lower stomatal conductance and greater water-use efficiency. Thus, the rapid development of deep roots appears to be an important strategy enabling evergreen species to overcome seasonal water limitation, whereas, in addition to losing a portion of their leaves, drought-deciduous trees minimize water loss from remaining leaves during the dry season.

Time-dependent Measure of a Nanoscale Force-pulse Driven by the Axonemal Dynein Motors in Individual Live Sperm Cells

Nanomedicine : Nanotechnology, Biology, and Medicine. Aug, 2010  |  Pubmed ID: 20060073

Nanoscale mechanical forces generated by motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces is important to developing motile biomimetic nanodevices powered by biological motors for nanomedicine. Axonemal dynein motors positioned inside the sperm flagellum drive microtubule sliding and give rise to rhythmic beating. This force-generating action pushes the sperm cell through viscous media. Here we report new nanoscale information on how the propulsive force is generated by the sperm flagellum and how this force varies over time. Using a modified atomic force microscope, single-cell recordings reveal discrete approximately 50-ms pulses oscillating with amplitude 9.8 +/- 2.6 nN independent of pulse frequency (3.5-19.5 Hz). The average work carried out by each cell is 4.6 x 10(-16) J per pulse, equivalent to the hydrolysis of approximately 5500 molecules of adenosine triphosphate. The mechanochemical coupling at each active dynein head is approximately 2.2 pN per adenosine triphosphate molecule and approximately 3.9 pN per dynein arm. From the clinical editor: In this paper, nanoscale mechanical forces generated by axonemal dynein motors derived from sperm flagellum are examined and reported. These motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces is important to developing motile biomimetic nanodevices powered by biological motors for nanomedicine.

Medical Education Needs to Teach Health Technology Assessment

Medical Teacher. Jan, 2010  |  Pubmed ID: 20095776

Health technology assessment evaluates the effects of drugs, devices, procedures and policies on patients and the healthcare system. Because of its potential to optimize healthcare resources and patient care, health technology assessment is becoming increasingly important in healthcare systems at national and local levels. This article provides an explanation of health technology assessment and an example of its application in residency education.

Videoconferencing of a National Program for Residents on Evidence-based Practice: Early Performance Evaluation

Journal of the American College of Radiology : JACR. 2010  |  Pubmed ID: 20142089

The aim of this study was to evaluate the effectiveness of the medium of videoconferencing for the delivery of a course for radiology residents in practice-based learning (PBL), including evidence-based practice, at centers geographically separated from the principal teaching site.

Carbon Stable Isotopic Composition of Soluble Sugars in Tillandsia Epiphytes Varies in Response to Shifts in Habitat

Oecologia. Jul, 2010  |  Pubmed ID: 20155286

We studied C stable isotopic composition (delta(13)C) of bulk leaf tissue and extracted sugars of four epiphytic Tillandsia species to investigate flexibility in the use of crassulacean acid metabolism (CAM) and C(3) photosynthetic pathways. Plants growing in two seasonally dry tropical forest reserves in Mexico that differ in annual precipitation were measured during wet and dry seasons, and among secondary, mature, and wetland forest types within each site. Dry season sugars were more enriched in (13)C than wet season sugars, but there was no seasonal difference in bulk tissues. Bulk tissue delta(13)C differed by species and by forest type, with values from open-canopied wetlands more enriched in (13)C than mature or secondary forest types. The shifts within forest habitat were related to temporal and spatial changes in vapor pressure deficits (VPD). Modeling results estimate a possible 4% increase in the proportional contribution of the C(3) pathway during the wet season, emphasizing that any seasonal or habitat-mediated variation in photosynthetic pathway appears to be quite moderate and within the range of isotopic effects caused by variation in stomatal conductance during assimilation through the C(3) pathway and environmental variation in VPD. C isotopic analysis of sugars together with bulk leaf tissue offers a useful approach for incorporating short- and long-term measurements of C isotope discrimination during photosynthesis.

Secondary Stroke Prevention Best Practice Recommendations: Exploring Barriers for Rural Family Physicians

Canadian Journal of Rural Medicine : the Official Journal of the Society of Rural Physicians of Canada = Journal Canadien De La Médecine Rurale : Le Journal Officiel De La Société De Médecine Rurale Du Canada. 2010  |  Pubmed ID: 20875313

Patients' risk of having a second stroke can be substantially reduced by implementing best practice recommendations for secondary stroke prevention. However, evidence indicates that rural practitioners may face barriers to implementing these recommendations into their practices. This research project developed a workshop to increase practitioner awareness of the recommendations, and to identify barriers to the application of recommendations for secondary prevention of stroke in rural practices.

Ecosystem CO2 Fluxes of Arbuscular and Ectomycorrhizal Dominated Vegetation Types Are Differentially Influenced by Precipitation and Temperature

The New Phytologist. Jan, 2010  |  Pubmed ID: 19825017

Here, we explore how interannual variations in environmental factors (i.e. temperature, precipitation and light) influence CO(2) fluxes (gross primary production and ecosystem respiration) in terrestrial ecosystems classified by vegetation type and the mycorrhizal type of dominant plants (arbuscular mycorrhizal (AM) or ectomycorrhizal (EM)). We combined 236 site-year measurements of terrestrial ecosystem CO(2) fluxes and environmental factors from 50 eddy-covariance flux tower sites with information about climate, vegetation type and dominant plant species. Across large geographical distances, interannual variations in ecosystem CO(2) fluxes for EM-dominated sites were primarily controlled by interannual variations in mean annual temperature. By contrast, interannual variations in ecosystem CO(2) fluxes at AM-dominated sites were primarily controlled by interannual variations in precipitation. This study represents the first large-scale assessment of terrestrial CO(2) fluxes in multiple vegetation types classified according to dominant mycorrhizal association. Our results support and complement the hypothesis that bioclimatic conditions influence the distribution of AM and EM systems across large geographical distances, which leads to important differences in the major climatic factors controlling ecosystem CO(2) fluxes.

Presentation of Evidence in Continuing Medical Education Programs: a Mixed Methods Study

The Journal of Continuing Education in the Health Professions. 2010  |  Pubmed ID: 21171027

Clinical trial data can be presented in ways that exaggerate treatment effectiveness. Physicians consider therapy more effective, and may be more likely to make inappropriate practice changes, when data are presented in relative terms such as relative risk reduction rather than in absolute terms such as absolute risk reduction and number needed to treat. Our purpose was to determine (1) how frequently continuing medical education (CME) speakers present research data in relative terms compared to absolute terms; (2) how knowledgeable CME speakers and learners are about these terms; and (3) how CME learners want these terms presented.

First Report of the Ectomycorrhizal Status of Boletes on the Northern Yucatan Peninsula, Mexico Determined Using Isotopic Methods

Mycorrhiza. Aug, 2011  |  Pubmed ID: 21210158

Despite their prominent role for tree growth, few studies have examined the occurrence of ectomycorrhizal fungi in lowland, seasonally dry tropical forests (SDTF). Although fruiting bodies of boletes have been observed in a dry tropical forest on the Northern Yucatan Peninsula, Mexico, their occurrence is rare and their mycorrhizal status is uncertain. To determine the trophic status (mycorrhizal vs. saprotrophic) of these boletes, fruiting bodies were collected and isotopically compared to known saprotrophic fungi, foliage, and soil from the same site. Mean δ(15)N and δ(13)C values differed significantly between boletes and saprotrophic fungi, with boletes 8.0‰ enriched and 2.5‰ depleted in (15)N and (13)C, respectively relative to saprotrophic fungi. Foliage was depleted in (13)C relative to both boletes and saprotrophic fungi. Foliar δ(15)N values, on the other hand, were similar to saprotrophic fungi, yet were considerably lower relative to bolete fruiting bodies. Results from this study provide the first isotopic evidence of ectomycorrhizal fungi in lowland SDTF and emphasize the need for further research to better understand the diversity and ecological importance of ectomycorrhizal fungi in these forested ecosystems.

Effect of Nicotine Replacement Therapy on Agitation in Smokers with Schizophrenia: a Double-blind, Randomized, Placebo-controlled Study

The American Journal of Psychiatry. Apr, 2011  |  Pubmed ID: 21245085

The authors conducted a randomized, placebo-controlled study of nicotine replacement therapy for the reduction of agitation and aggression in smokers with schizophrenia.

Genome Sequence of Ostreococcus Tauri Virus OtV-2 Throws Light on the Role of Picoeukaryote Niche Separation in the Ocean

Journal of Virology. May, 2011  |  Pubmed ID: 21289127

Ostreococcus tauri, a unicellular marine green alga, is the smallest known free-living eukaryote and is ubiquitous in the surface oceans. The ecological success of this organism has been attributed to distinct low- and high-light-adapted ecotypes existing in different niches at a range of depths in the ocean. Viruses have already been characterized that infect the high-light-adapted strains. Ostreococcus tauri virus (OtV) isolate OtV-2 is a large double-stranded DNA algal virus that infects a low-light-adapted strain of O. tauri and was assigned to the algal virus family Phycodnaviridae, genus Prasinovirus. Our working hypothesis for this study was that different viruses infecting high- versus low-light-adapted O. tauri strains would provide clues to propagation strategies that would give them selective advantages within their particular light niche. Sequence analysis of the 184,409-bp linear OtV-2 genome revealed a range of core functional genes exclusive to this low-light genotype and included a variety of unexpected genes, such as those encoding an RNA polymerase sigma factor, at least four DNA methyltransferases, a cytochrome b(5), and a high-affinity phosphate transporter. It is clear that OtV-2 has acquired a range of potentially functional genes from its host, other eukaryotes, and even bacteria over evolutionary time. Such piecemeal accretion of genes is a trademark of large double-stranded DNA viruses that has allowed them to adapt their propagation strategies to keep up with host niche separation in the sunlit layers of the oceanic environment.

Efficacy and Safety of Loxapine for Inhalation in the Treatment of Agitation in Patients with Schizophrenia: a Randomized, Double-blind, Placebo-controlled Trial

The Journal of Clinical Psychiatry. Oct, 2011  |  Pubmed ID: 21294997

The objective of this study was to assess the efficacy and safety of inhaled loxapine in the treatment of agitation in patients with psychotic disorders.

Adaptive Style and Physiological Reactivity During a Laboratory Stress Paradigm in Children with Cancer and Healthy Controls

Journal of Behavioral Medicine. Oct, 2011  |  Pubmed ID: 21305350

Repressive adaptation has been conceptualized as one pathway to psychological resilience in children with cancer, but the physiological costs of maintaining a repressive adaptive style are currently unknown. The goal of this study was to examine physiological functioning as a function of adaptive style in children with cancer (N = 120) and healthy controls (N = 120). Children completed self-report measures of state anxiety and defensiveness prior to participating in three verbal stress tasks while monitoring blood pressure, electrocardiogram, and electrodermal response, and rated their anxiety following each task. Findings indicated no consistent differences in baseline indices and physiological reactivity as a function of adaptive style or health status (cancer vs. control). In addition, children identified as having a repressive adaptive style did not exhibit greater verbal-autonomic discrepancy than low-anxious children. In contrast to findings with adults, children with a repressive adaptive style do not appear to experience adverse effects of this coping style in terms of physiological reactivity.

Identification and Functional Characterisation of Genes Encoding the Omega-3 Polyunsaturated Fatty Acid Biosynthetic Pathway from the Coccolithophore Emiliania Huxleyi

Phytochemistry. May, 2011  |  Pubmed ID: 21316718

The Prymnesiophyceae coccolithophore Emiliania huxleyi is one of the most abundant alga in our oceans and therefore plays a central role in marine foodwebs. E. huxleyi is notable for the synthesis and accumulation of the omega-3 long chain polyunsaturated fatty acid docosahexaenoic acid (DHA; 22:6Δ(4,7,10,13,16,19), n-3) which is accumulated in fish oils and known to have health-beneficial properties to humans, preventing cardiovascular disease and related pathologies. Here we describe the identification and functional characterisation of the five E. huxleyi genes which direct the synthesis of docosahexaenoic acid in this alga. Surprisingly, E. huxleyi does not use the conventional Δ6-pathway, instead using the alternative Δ8-desaturation route which has previously only been observed in a few unrelated microorganisms. Given that E. huxleyi accumulates significant levels of the Δ6-desaturated fatty acid stearidonic acid (18:4Δ(6,9,12,15), n-3), we infer that the biosynthesis of DHA is likely to be metabolically compartmentalised from the synthesis of stearidonic acid.

Clinical and Functional Significance of α9β1 Integrin Expression in Breast Cancer: a Novel Cell-surface Marker of the Basal Phenotype That Promotes Tumour Cell Invasion

The Journal of Pathology. Apr, 2011  |  Pubmed ID: 21341269

Integrin α9β1 is a receptor for ECM proteins, including Tenascin-C and the EDA domain of fibronectin, and has been shown to transduce TGFβ signalling. This study has examined the expression pattern of α9β1 in 141 frozen breast carcinoma samples and related expression to prognostic indices, molecular subtype and patient outcome. Effects of α9β1 on tumour cell migration and invasion were assessed using blocking antibody and gene transduction approaches. Integrin α9β1 localized to myoepithelial cells in normal ducts and acini, a pattern maintained in DCIS. A subset (17%) of invasive carcinomas exhibited tumour cell expression of α9β1, which related significantly to the basal-like phenotype, as defined by either CK5/6 or CK14 expression. Tumour expression of α9β1 showed a significant association with reduced overall patient survival (p < 0.0001; HR 5.94, 95%CI 3.26-10.82) and with reduced distant-metastasis-free survival (p < 0.0001; HR 6.37, CI 3.51-11.58). A series of breast cancer cell lines was screened for α9β1 with the highly invasive basal-like GI-101 cell line expressing significant levels. Both migration and invasion of this line were reduced significantly in the presence of α9-blocking antibody and following α9-knockdown with siRNA. Conversely, migratory and invasive behaviour of α9-negative MCF7 cells and α9-low MDA MB468 cells was enhanced significantly by over-expression of α9. Thus, α9β1 acts as a novel marker of the basal-like breast cancer subtype and expression is associated with reduced survival, while its ability to promote breast cancer cell migration and invasion suggests that it contributes to the aggressive clinical behaviour of this tumour subtype.

Characterisation of the Coccolithovirus Intein

Marine Genomics. Mar, 2011  |  Pubmed ID: 21429459

The identification of inteins in viral genomes is becoming increasingly common. Inteins are selfish DNA elements found within coding regions of host proteins. Following translation, they catalyse their own excision and the formation of a peptide bond between the flanking protein regions. Many inteins also display homing endonuclease function. Here, the newly identified coccolithovirus intein is described and is predicted to have both self-splicing and homing endonuclease activity. The biochemical mechanism of its protein splicing activity is hypothesised, and the prevalence of the intein among natural coccolithovirus isolates is tested.

Luminescent Kinase Activity Biosensors Based on a Versatile Bimolecular Switch

Journal of the American Chemical Society. Apr, 2011  |  Pubmed ID: 21438554

Real-time tracking of kinase activity in living systems has revealed new modes of encoding signaling information into spatiotemporal activity patterns and opened new avenues for screening kinase modulators. However, the sensitivity of kinase activity detection, which is commonly coupled to a fluorescence resonance energy transfer (FRET)-based readout, has often been a limiting factor. Here we show that a kinase-inducible bimolecular switch consisting of a substrate for the kinase of interest and a phosphoamino acid binding domain can be designed to sense different kinase activities and coupled to various readouts, thereby allowing for examination of dynamic kinase activity with increased sensitivity and versatility. Specifically, we demonstrate that bimolecular switches designed to sense protein kinase A (PKA) or protein kinase C (PKC) activities can turn on FRET as well as bioluminescence signals. Notably, the FRET-based sensors gain larger dynamic ranges in comparison with their unimolecular counterparts; the novel bioluminescence-based reporters for PKA and PKC show high sensitivity and a unique capability to detect basal kinase activities and should enable new applications in in vivo imaging of kinase activity and high-throughput compound screening. Thus, this generalizable design advances the molecular toolkit of kinase activity detection and provides a means for versatile and sensitive detection of kinase activity in various biological systems.

Thyrotropin Receptor Stimulates Internalization-independent Persistent Phosphoinositide Signaling

Molecular Pharmacology. Aug, 2011  |  Pubmed ID: 21525174

The thyrotropin [thyroid-stimulating hormone (TSH)] receptor (TSHR) is known to acutely and persistently stimulate cAMP signaling and at higher TSH concentrations to acutely stimulate phosphoinositide signaling. We measured persistent signaling by stimulating TSHR-expressing human embryonic kidney-EM293 cells with TSH and measuring cAMP or inositol monophosphate (IP1) production, a measure of phosphoinositide signaling, 60 min or longer after TSH removal. In contrast to persistent cAMP production, persistent IP1 production increased progressively when TSH exposure was increased from 1 to 30 min, whereas the rates of decay of persistent signaling were similar. A small-molecule agonist and a thyroid-stimulating antibody also caused persistent IP1 and cAMP signaling. A small-molecule inverse agonist and a neutral antagonist inhibited TSH-stimulated persistent IP1 production, whereas the inverse agonist but not the neutral antagonist inhibited persistent cAMP production. As with persistent cAMP production, persistent IP1 production was not affected when TSHR internalization was inhibited or enhanced. Moreover, Alexa546-TSH-activated TSHR internalization was not accompanied by Gα(q) coupling protein internalization. Thus, transient exposure to high concentrations of TSH causes persistent phosphoinositide and cAMP signaling that is not dependent on internalization. To our knowledge, this is the first demonstration of persistent activation by any G protein-coupled receptor (GPCR) via the Gα(q) pathway and of two G protein-mediated pathways by any GPCR.

Atomic Force Microscopy of Connexin40 Gap Junction Hemichannels Reveals Calcium-dependent Three-dimensional Molecular Topography and Open-closed Conformations of Both the Extracellular and Cytoplasmic Faces

The Journal of Biological Chemistry. Jun, 2011  |  Pubmed ID: 21543330

Atomic force microscopy was used to study the three-dimensional molecular topography and calcium-sensitive conformational changes of Connexin40 hemichannels (connexons) reconstituted in 1,2-dioeloyl-sn-glycero-3-phosphatidylcholine lipid bilayers. Two classes of objects were observed that differed in their protrusion heights above the bilayer (2.6 versus 4.2 nm). Comparison to reconstituted connexons containing Connexin40 truncated to eliminate most of its C-terminal cytoplasmic domain showed that the two height classes corresponded to the shorter extracellular and taller cytoplasmic aspects of the hemichannels and that the C-terminal tail of Connexin40 contributes ∼1.6 nm in thickness. Hemichannels imaged in solutions containing < 10 μm Ca(2+) showed 3.1-3.2 nm depressions (openings) in 30% of the cytoplasmic faces and 65% of the extracellular faces, and high-resolution three-dimensional topography of extracellular or cytoplasmic aspects of some connexons was observed. After addition of 3.6 mm Ca(2+), > 75% of the connexons in either orientation adopted closed conformations. In contrast, hemichannels imaged in the presence of 0.1 mm EDTA showed large (5.6- to 5.8-nm diameter) openings in nearly all hemichannels regardless of orientation, and detailed topography was visible in many connexons. Real-time imaging following the addition of 3.6 mm Ca(2+) showed transitions of both extracellular and cytoplasmic orientations from "open" into "closed" conformations within several minutes. These studies provide the first high-resolution topographic information regarding a connexin with a large cytoplasmic domain and suggest that the extramembranous portions of Connexin40 contribute to a channel entrance that is relaxed by chelation of residual divalent cations.

Tailoring Charge Density and Hydrogen Bonding of Imidazolium Copolymers for Efficient Gene Delivery

Biomacromolecules. Jun, 2011  |  Pubmed ID: 21557603

Conventional free radical polymerization with subsequent postpolymerization modification afforded imidazolium copolymers with controlled charge density and side chain hydroxyl number. Novel imidazolium-containing copolymers where each permanent cation contained one or two adjacent hydroxyls allowed precise structure-transfection efficiency studies. The degree of polymerization was identical for all copolymers to eliminate the influence of molecular weight on transfection efficiency. DNA binding, cytotoxicity, and in vitro gene transfection in African green monkey COS-7 cells revealed structure-property-transfection relationships for the copolymers. DNA gel shift assays indicated that higher charge densities and hydroxyl concentrations increased DNA binding. As the charge density of the copolymers increased, toxicity of the copolymers also increased; however, as hydroxyl concentration increased, cytotoxicity remained constant. Changing both charge density and hydroxyl levels in a systematic fashion revealed a dramatic influence on transfection efficiency. Dynamic light scattering of the polyplexes, which were composed of copolymer concentrations required for the highest luciferase expression, showed an intermediate DNA-copolymer binding affinity. Our studies supported the conclusion that cationic copolymer binding affinity significantly impacts overall transfection efficiency of DNA delivery vehicles, and the incorporation of hydroxyl sites offers a less toxic and effective alternative to more conventional highly charged copolymers.

Evaluating the Potential Efficacy of Invasive Lionfish (Pterois Volitans) Removals

PloS One. 2011  |  Pubmed ID: 21572951

The lionfish, Pterois volitans (Linnaeus) and Pterois miles (Bennett), invasion of the Western Atlantic Ocean, Caribbean Sea and Gulf of Mexico has the potential to alter aquatic communities and represents a legitimate ecological concern. Several local removal programs have been initiated to control this invasion, but it is not known whether removal efforts can substantially reduce lionfish numbers to ameliorate these concerns. We used an age-structured population model to evaluate the potential efficacy of lionfish removal programs and identified critical data gaps for future studies. We used high and low estimates for uncertain parameters including: length at 50% vulnerability to harvest (L(vul)), instantaneous natural mortality (M), and the Goodyear compensation ratio (CR). The model predicted an annual exploitation rate between 35 and 65% would be required to cause recruitment overfishing on lionfish populations for our baseline parameter estimates for M and CR (0.5 and 15). Lionfish quickly recovered from high removal rates, reaching 90% of unfished biomass six years after a 50-year simulated removal program. Quantifying lionfish natural mortality and the size-selective vulnerability to harvest are the most important knowledge gaps for future research. We suggest complete eradication of lionfish through fishing is unlikely, and substantial reduction of adult abundance will require a long-term commitment and may be feasible only in small, localized areas where annual exploitation can be intense over multiple consecutive years.

Improving the Wang-Landau Algorithm for Polymers and Proteins

Journal of Computational Chemistry. Apr, 2011  |  Pubmed ID: 20941735

The 1/t Wang-Landau algorithm is tested on simple models of polymers and proteins. It is found that this method resolves the problem of the saturation of the error present in the original algorithm for lattice polymers. However, for lattice proteins, which have a rough energy landscape with an unknown energy minimum, it is found that the density of states does not converge in all runs. A new variant of the Wang-Landau algorithm that appears to solve this problem is described and tested. In the new variant, the optimum modification factor is calculated in the same straightforward way throughout the simulation. There is only one free parameter for which a value of unity appears to give near optimal convergence for all run lengths for lattice homopolymers when pull moves are used. For lattice proteins, a much smaller value of the parameter is needed to ensure rapid convergence of the density of states for energies discovered late in the simulation, which unfortunately results in poor convergence early on in the run.

Controlled Evaluation of the Effects of Hyperbaric Oxygen Therapy on the Behavior of 16 Children with Autism Spectrum Disorders

Journal of Autism and Developmental Disorders. May, 2011  |  Pubmed ID: 20680427

Hyperbaric oxygen therapy (HBOT) has been used to treat individuals with autism. However, few studies of its effectiveness have been completed. The current study examined the effects of 40 HBOT sessions at 24% oxygen at 1.3 ATA on 11 topographies of directly observed behavior. Five replications of multiple baselines were completed across a total of 16 participants with autism spectrum disorders. No consistent effects were observed across any group or within any individual participant, demonstrating that HBOT was not an effective treatment for the participants in this study. This study represents the first relatively large-scale controlled study evaluating the effects of HBOT at the level of the individual participant, on a wide array of behaviors.

Ventilatory Inefficiency Reflects Right Ventricular Dysfunction in Systolic Heart Failure

Chest. Mar, 2011  |  Pubmed ID: 20688926

An increased minute ventilation (VE)/carbon dioxide production (VCO2) relationship, an expression of ventilatory inefficiency (VI), is associated with increased morbidity and mortality in patients with left ventricular systolic dysfunction (LVSD). A direct link between VI and a specific cardiac abnormality has not been established.

Visualization of PKA Activity in Plasma Membrane Microdomains

Molecular BioSystems. Jan, 2011  |  Pubmed ID: 20838685

Membrane rafts are sphingolipid- and cholesterol-rich microdomains that contain dynamic arrangements of signaling proteins. Notably, various components of the ubiquitous cAMP/Protein Kinase A (PKA) pathway, including β-adrenergic receptors (β-ARs), G proteins, and adenylyl cyclases (ACs), have been shown to localize differentially between membrane rafts and non-raft regions of the plasma membrane. As PKA participates in regulating diverse fundamental cellular functions, a number of which require membrane rafts, it is important to understand how PKA activity is specifically regulated in these membrane microdomains. To this end, we developed an improved FRET-based PKA activity biosensor, and targeted it to both membrane raft and non-raft regions of the plasma membrane to examine PKA activity dynamics in different plasma membrane microdomains. Disruption of membrane rafts via cholesterol depletion was shown to enhance β-AR stimulated PKA activity at the plasma membrane, suggesting that membrane rafts play a negative role in β-AR stimulated PKA activation. Furthermore, we found that membrane rafts possess higher basal PKA activity in the resting state compared to non-raft regions, which depends on the integrity of membrane rafts and proper localization of PKA. This study shows that membrane rafts play an important role in regulating the activity of PKA at the plasma membrane, and demonstrates the ability of live-cell FRET-based assays to reveal dynamic differences amongst plasma membrane microdomains, laying a foundation for further dissection of membrane regulated signal transduction.

Signaling Diversity of PKA Achieved Via a Ca2+-cAMP-PKA Oscillatory Circuit

Nature Chemical Biology. Jan, 2011  |  Pubmed ID: 21102470

Many protein kinases are key nodal signaling molecules that regulate a wide range of cellular functions. These functions may require complex spatiotemporal regulation of kinase activities. Here, we show that protein kinase A (PKA), Ca(2+) and cyclic AMP (cAMP) oscillate in sync in insulin-secreting MIN6 beta cells, forming a highly integrated oscillatory circuit. We found that PKA activity was essential for this oscillatory circuit and was capable of not only initiating the signaling oscillations but also modulating their frequency, thereby diversifying the spatiotemporal control of downstream signaling. Our findings suggest that exquisite temporal control of kinase activity, mediated via signaling circuits resulting from cross-regulation of signaling pathways, can encode diverse inputs into temporal parameters such as oscillation frequency, which in turn contribute to proper regulation of complex cellular functions in a context-dependent manner.

Jekyll and Hyde: the Role of the Microenvironment on the Progression of Cancer

The Journal of Pathology. Jan, 2011  |  Pubmed ID: 21125673

It is now recognized that the host microenvironment undergoes extensive change during the evolution and progression of cancer. This involves the generation of cancer-associated fibroblasts (CAFs), which, through release of growth factors and cytokines, lead to enhanced angiogenesis, increased tumour growth and invasion. It has also been demonstrated that CAFs may modulate the cancer stem cell (CSC) phenotype, which has therapeutic implications. The altered fibroblast phenotype also contributes to the development of an altered extracellular matrix (ECM), with synthesis of ECM isoforms rarely found in normal tissues, including tenascin-C isoforms and the fibronectin EDA isoform. There is also emerging evidence of how the tensile strength of the tumour-associated ECM may be modified and lead to altered signalling in tumour cells. The hypoxic environment of the tumour stimulates angiogenesis and also impacts on other aspects of cell signalling, including the c-met pathway and lysyl oxidase-mediated signalling, which can directly promote tumour cell invasion. The inflammatory infiltrate associated with many solid tumours also modulates tumour function, having both anti- and pro-tumour effects. All of these components of the microenvironment provide potential targets for therapeutic attack, with a number of molecules already in clinical trials. It is also becoming evident that characterizing the tumour microenvironment can provide important prognostic and predictive information about tumours, independent of the tumour cell phenotype.

Draft Genome Sequence of the Coccolithovirus EhV-84

Standards in Genomic Sciences. Oct, 2011  |  Pubmed ID: 22180805

The Coccolithoviridae is a recently discovered group of viruses that infect the marine coccolithophorid Emiliania huxleyi. Emiliania huxleyi virus 84 (EhV-84) has a 160 -180 nm diameter icosahedral structure and a genome of approximately 400 kbp. Here we describe the structural and genomic features of this virus, together with a near complete draft genome sequence (~99%) and its annotation. This is the fourth genome sequence of a member of the coccolithovirus family.

Above- and Belowground Responses to Nitrogen Addition in a Chihuahuan Desert Grassland

Oecologia. Nov, 2011  |  Pubmed ID: 22042525

Increased available soil nitrogen can increase biomass, lower species richness, alter soil chemistry and modify community structure in herbaceous ecosystems worldwide. Although increased nitrogen availability typically increases aboveground production and decreases species richness in mesic systems, the impacts of nitrogen additions on semiarid ecosystems remain unclear. To determine how a semiarid grassland responds to increased nitrogen availability, we examined plant community structure and above- and belowground net primary production in response to long-term nitrogen addition in a desert grassland in central New Mexico, USA. Plots were fertilized annually (10 g N m(-2)) since 1995 and NPP measured from 2004 to 2009. Differences in aboveground NPP between fertilized and control treatments occurred in 2004 following a prescribed fire and in 2006 when precipitation was double the long-term average during the summer monsoon. Presumably, nitrogen only became limiting once drought stress was alleviated. Belowground NPP was also related to precipitation, and greatest root growth occurred the year following the wettest summer, decreasing gradually thereafter. Belowground production was unrelated to aboveground production within years and unrelated to nitrogen enrichment. Species richness changed between years in response to seasonal precipitation variability, but was not altered by nitrogen addition. Community structure did respond to nitrogen fertilization primarily through increased abundance of two dominant perennial grasses. These results were contrary to most nitrogen addition studies that find increased biomass and decreased species richness with nitrogen fertilization. Therefore, factors other than nitrogen deposition, such as fire or drought, may play a stronger role in shaping semiarid grassland communities than soil fertility.

Unveiling the Transcriptional Features Associated with Coccolithovirus Infection of Natural Emiliania Huxleyi Blooms

FEMS Microbiology Ecology. Dec, 2011  |  Pubmed ID: 22066669

Lytic viruses have been implicated in the massive cellular lysis observed during algal blooms, through which they assume a prominent role in oceanic carbon and nutrient flows. Despite their impact on biogeochemical cycling, the transcriptional dynamics of these important oceanic events is still poorly understood. Here, we employ an oligonucleotide microarray to monitor host (Emiliania huxleyi) and virus (coccolithovirus) transcriptomic features during the course of E. huxleyi blooms induced in seawater-based mesocosm enclosures. Host bloom development and subsequent coccolithovirus infection was associated with a major shift in transcriptional profile. In addition to the expected metabolic requirements typically associated with viral infection (amino acid and nucleotide metabolism, as well as transcription- and replication-associated functions), the results strongly suggest that the manipulation of lipid metabolism plays a fundamental role during host-virus interaction. The results herein reveal the scale, so far massively underestimated, of the transcriptional domination that occurs during coccolithovirus infection in the natural environment.

Draft Genome Sequence of the Coccolithovirus Emiliania Huxleyi Virus 203

Journal of Virology. Dec, 2011  |  Pubmed ID: 22106382

The Coccolithoviridae are a recently discovered group of viruses that infect the marine coccolithophorid Emiliania huxleyi. Emiliania huxleyi virus 203 (EhV-203) has a 160- to 180-nm-diameter icosahedral structure and a genome of approximately 400 kbp, consisting of 464 coding sequences (CDSs). Here we describe the genomic features of EhV-203 together with a draft genome sequence and its annotation, highlighting the homology and heterogeneity of this genome in comparison with the EhV-86 reference genome.

Rapid Acute Treatment of Agitation in Individuals with Schizophrenia: Multicentre, Randomised, Placebo-controlled Study of Inhaled Loxapine

The British Journal of Psychiatry : the Journal of Mental Science. Jan, 2011  |  Pubmed ID: 21200077

There is a need for a rapid-acting, non-injection, acute treatment for agitation.

Interprofessional Education in Chronic Non-cancer Pain

Journal of Interprofessional Care. May, 2011  |  Pubmed ID: 21425918

Suicide and Suicide Attempts in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD)

Journal of Affective Disorders. Oct, 2011  |  Pubmed ID: 21601286

The current report describes individuals with bipolar disorder who attempted or completed suicide while participating in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) study.

Metacommunity Assembly and Sorting in Newly Formed Lake Communities

Ecology. Feb, 2011  |  Pubmed ID: 21618905

new habitats are created, community assembly may follow independent trajectories, since the relative importance of dispersal limitation, priority effects, species interactions, and environmental gradients can vary as assembly proceeds. Unfortunately, tracking community colonization and composition across decades is challenging. We compiled a multiyear community composition data set and reconstructed past communities with remains from sediment cores to investigate cladoceran assembly dynamics in six older (1920s) and two more recently formed (1950s) lakes. We found that current communities cluster along a gradient of thermal stratification that is known to influence predation intensity. Assembling communities showed evidence for a greater influence of species sorting and a reduced influence of spatial structure since the first colonizations. However, lake community trajectories varied considerably, reflecting different colonization sequences among lakes. In the older lakes, small-bodied cladocerans often arrived much earlier than large-bodied cladocerans, while the two younger lakes were colonized much more rapidly, and one was quickly dominated by a large-bodied species. Thus, by combining contemporary community data with paleoecological records, we show that assembly history influences natural community structure for decades while patterns of ecological sorting develop.

Occupancy of Both Sites on the Thyrotropin (TSH) Receptor Dimer is Necessary for Phosphoinositide Signaling

FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology. Oct, 2011  |  Pubmed ID: 21705666

The thyroid-stimulating hormone (TSH) receptor signals via G(s) to produce cAMP and via G(q/11) to produce inositol-1,4,5-trisphosphate, which is degraded to inositol monophosphate (IP1; phosphoinositide signaling). The potency of TSH for cAMP signaling is higher than for phosphoinositide signaling, and it was suggested that there are "spare receptors" for cAMP signaling. In a human embryonic kidney macrophage scavenger receptor-expressing (HEK-EM) 293 model system, there are no spare receptors, but the cells still exhibited 100-fold differences in potencies. Dose responses for TSH-stimulated dissociation of prebound (125)I-TSH (negative cooperativity; EC(50)=70 mU/ml), which requires TSH binding to both sites of the TSH receptor (TSHR) homodimer, and TSH-stimulated IP1 production (EC(50)=50 mU/ml) were indistinguishable. Fluorescence resonance energy transfer (FRET) using tagged receptors showed that TSHR formed homodimers and heterodimers with two binding-deficient mutant TSHRs, L252P and C41S. When L252P or C41S was expressed with TSHR, that is, when TSHR/L252P or TSHR/C41S heterodimers could only bind one TSH, TSH-stimulated IP1 production was decreased relative to cAMP production. The slopes of linear regression analyses comparing fold stimulation by TSH of IP1 vs. cAMP production were 0.044 ± 0.0047, 0.0043 ± 0.0041, and 0.0059 ± 0.0014 for cells expressing TSHR alone, TSHR and L252P, or TSHR and C41S, respectively. We suggest that TSHR coupling to phosphoinositide signaling is dependent on binding 2 molecules of TSH to TSHR homodimer, causing a conformational change allowing coupling to G(q/11).

Gender Differences and the Relationships of Perceived Background Stress and Psychological Distress with Cardiovascular Responses to Laboratory Stressors

International Journal of Psychophysiology : Official Journal of the International Organization of Psychophysiology. Sep, 2011  |  Pubmed ID: 21729723

The primary aim of this study was to evaluate the relationships of perceived background stress and self-reported psychological distress on cardiovascular reactivity during acute laboratory stressors. The Perceived Stress Scale (PSS) was used as the measure of perceived background stress, and the General Health Questionnaire (GHQ) was used as the measure of psychological distress. A secondary aim was to examine whether background stress and psychological distress affected the susceptibility to induction of a negative mood using music. Heart rate (HR) and blood pressure (BP) were measured in 149 female and male college students at rest and during a stressful mental arithmetic (MA) task and a mood induction procedure. Higher scores on the GHQ were associated with lower systolic BP reactivity during the MA task by all participants. Higher scores on the PSS and GHQ were also associated with lower diastolic BP and HR reactivity, but only in females. Thus, higher self-reports of background stress and psychological distress tended to result in blunted reactivity to an acute laboratory challenge. Higher levels of background stress and psychological distress were not associated with greater susceptibility to a negative mood induction. This study adds to the growing literature indicating that potentially negative health outcomes may be associated with diminished cardiovascular reactivity under certain conditions.

Coccolithophores: Functional Biodiversity, Enzymes and Bioprospecting

Marine Drugs. 2011  |  Pubmed ID: 21731551

Emiliania huxleyi is a single celled, marine phytoplankton with global distribution. As a key species for global biogeochemical cycling, a variety of strains have been amassed in various culture collections. Using a library consisting of 52 strains of E. huxleyi and an 'in house' enzyme screening program, we have assessed the functional biodiversity within this species of fundamental importance to global biogeochemical cycling, whilst at the same time determining their potential for exploitation in biocatalytic applications. Here, we describe the screening of E. huxleyi strains, as well as a coccolithovirus infected strain, for commercially relevant biocatalytic enzymes such as acid/alkali phosphodiesterase, acid/alkali phosphomonoesterase, EC1.1.1-type dehydrogenase, EC1.3.1-type dehydrogenase and carboxylesterase.

Small-molecule Thyrotropin Receptor Agonist Activates Naturally Occurring Thyrotropin-insensitive Mutants and Reveals Their Distinct Cyclic Adenosine Monophosphate Signal Persistence

Thyroid : Official Journal of the American Thyroid Association. Aug, 2011  |  Pubmed ID: 21745101

Subclinical hypothyroidism (SHT), characterized by normal thyroid hormone levels maintained by elevated thyrotropin (TSH), predisposes patients to health problems as they age. Some cases arise from mutations of the TSH receptor (TSHR) that confer TSH resistance. This resistance might be circumvented by TSHR agonists with different modes of binding compared with TSH. We hypothesized that the recently discovered small-molecule TSHR agonist C2, with its unique mode of receptor binding, would activate mutant TSHRs associated with SHT, facilitating their study.

Spatiotemporally Regulated Protein Kinase A Activity is a Critical Regulator of Growth Factor-stimulated Extracellular Signal-regulated Kinase Signaling in PC12 Cells

Molecular and Cellular Biology. Oct, 2011  |  Pubmed ID: 21807900

PC12 cells exhibit precise temporal control of growth factor signaling in which stimulation with epidermal growth factor (EGF) leads to transient extracellular signal-regulated kinase (ERK) activity and cell proliferation, whereas nerve growth factor (NGF) stimulation leads to sustained ERK activity and differentiation. While cyclic AMP (cAMP)-mediated signaling has been shown to be important in conferring the sustained ERK activity achieved by NGF, little is known about the regulation of cAMP and cAMP-dependent protein kinase (PKA) in these cells. Using fluorescence resonance energy transfer (FRET)-based biosensors localized to discrete subcellular locations, we showed that both NGF and EGF potently activate PKA at the plasma membrane, although they generate temporally distinct activity patterns. We further show that both stimuli fail to induce cytosolic PKA activity and identify phosphodiesterase 3 (PDE3) as a critical regulator in maintaining this spatial compartmentalization. Importantly, inhibition of PDE3, and thus perturbation of the spatiotemporal regulation of PKA activity, dramatically increases the duration of EGF-stimulated nuclear ERK activity in a PKA-dependent manner. Together, these findings identify EGF and NGF as potent activators of PKA activity specifically at the plasma membrane and reveal a novel regulatory mechanism contributing to the growth factor signaling specificity achieved by NGF and EGF in PC12 cells.

Current Practices for Mental Health Follow-up After Psychiatric Emergency Department/psychiatric Emergency Service Visits: a National Survey of Academic Emergency Departments

General Hospital Psychiatry. Nov, 2011  |  Pubmed ID: 21872940

The objective was to describe continuity of care approaches for psychiatric emergencies in the emergency department.

Mutant SOD1 Forms Ion Channel: Implications for ALS Pathophysiology

Neurobiology of Disease. Mar, 2012  |  Pubmed ID: 21930207

Point mutations in the gene encoding copper-zinc superoxide dismutase (SOD1) impart a gain-of-function to this protein that underlies 20-25% of all familial amyotrophic lateral sclerosis (FALS) cases. However, the specific mechanism of mutant SOD1 toxicity has remained elusive. Using the complementary techniques of atomic force microscopy (AFM), electrophysiology, and cell and molecular biology, here we examine the structure and activity of A4VSOD1, a mutant SOD1. AFM of A4VSOD1 reconstituted in lipid membrane shows discrete tetrameric pore-like structure with outer and inner diameters 12.2 and 3.0nm respectively. Electrophysiological recordings show distinct ionic conductances across bilayer for A4VSOD1 and none for wildtype SOD1. Mouse neuroblastoma cells exposed to A4VSOD1 undergo membrane depolarization and increases in intracellular calcium. These results provide compelling new evidence that a mutant SOD1 is capable of disrupting cellular homeostasis via an unregulated ion channel mechanism. Such a "toxic channel" mechanism presents a new therapeutic direction for ALS research.

Phosphonium-containing Polyelectrolytes for Nonviral Gene Delivery

Biomacromolecules. Jan, 2012  |  Pubmed ID: 22136386

Nonviral gene therapy focuses intensely on nitrogen-containing macromolecules and lipids to condense and deliver DNA as a therapeutic for genetic human diseases. For the first time, DNA binding and gene transfection experiments compared phosphonium-containing macromolecules with their respective ammonium analogs. Conventional free radical polymerization of quaternized 4-vinylbenzyl chloride monomers afforded phosphonium- and ammonium-containing homopolymers for gene transfection experiments of HeLa cells. Aqueous size exclusion chromatography confirmed similar absolute molecular weights for all polyelectrolytes. DNA gel shift assays and luciferase expression assays revealed phosphonium-containing polymers bound DNA at lower charge ratios and displayed improved luciferase expression relative to the ammonium analogs. The triethyl-based vectors for both cations failed to transfect HeLa cells, whereas tributyl-based vectors successfully transfected HeLa cells similar to Superfect demonstrating the influence of the alkyl substituent lengths on the efficacy of the gene delivery vehicle. Cellular uptake of Cy5-labeled DNA highlighted successful cellular uptake of triethyl-based polyplexes, showing that intracellular mechanisms presumably prevented luciferase expression. Endocytic inhibition studies using genistein, methyl β-cyclodextrin, or amantadine demonstrated the caveolae-mediated pathway as the preferred cellular uptake mechanism for the delivery vehicles examined. Our studies demonstrated that changing the polymeric cation from ammonium to phosphonium enables an unexplored array of synthetic vectors for enhanced DNA binding and transfection that may transform the field of nonviral gene delivery.

Meta-analysis Supports ACCORD Blood Pressure but Effect of Excessive DBP Lowering Uncertain

Journal of Hypertension. Feb, 2012  |  Pubmed ID: 22236978

Pyridyl-2,5-diketopiperazines As Potent, Selective, and Orally Bioavailable Oxytocin Antagonists: Synthesis, Pharmacokinetics, and in Vivo Potency

Journal of Medicinal Chemistry. Jan, 2012  |  Pubmed ID: 22239250

A six-stage stereoselective synthesis of indanyl-7-(3'-pyridyl)-(3R,6R,7R)-2,5-diketopiperazines oxytocin antagonists from indene is described. SAR studies involving mono- and disubstitution in the 3'-pyridyl ring and variation of the 3-isobutyl group gave potent compounds (pK(i) > 9.0) with good aqueous solubility. Evaluation of the pharmacokinetic profile in the rat, dog, and cynomolgus monkey of those derivatives with low cynomolgus monkey and human intrinsic clearance gave 2',6'-dimethyl-3'-pyridyl R-sec-butyl morpholine amide Epelsiban (69), a highly potent oxytocin antagonist (pK(i) = 9.9) with >31000-fold selectivity over all three human vasopressin receptors hV1aR, hV2R, and hV1bR, with no significant P450 inhibition. Epelsiban has low levels of intrinsic clearance against the microsomes of four species, good bioavailability (55%) and comparable potency to atosiban in the rat, but is 100-fold more potent than the latter in vitro and was negative in the genotoxicity screens with a satisfactory oral safety profile in female rats.

Draft Genome Sequence of the Coccolithovirus Emiliania Huxleyi Virus 202

Journal of Virology. Feb, 2012  |  Pubmed ID: 22282334

Emiliania huxleyi virus 202 (EhV-202) is a member of the Coccolithoviridae, a group of viruses that infect the marine coccolithophorid Emiliania huxleyi. EhV-202 has a 160- to 180-nm-diameter icosahedral structure and a genome of approximately 407 kbp, consisting of 485 coding sequences (CDSs). Here we describe the genomic features of EhV-202, together with a draft genome sequence and its annotation, highlighting the homology and heterogeneity of this genome in comparison with the EhV-86 reference genome.

Multicenter Study of Predictors of Suicide Screening in Emergency Departments

Academic Emergency Medicine : Official Journal of the Society for Academic Emergency Medicine. Feb, 2012  |  Pubmed ID: 22288721

Objectives:  The objective was to provide estimates and predictors of screening for suicide in emergency departments (EDs). Methods:  Eight geographically diverse U.S. EDs each performed chart reviews of 100 randomly selected patients, ages 18 years or older, with visits in October 2009. Trained chart abstractors collected information on patient demographics, presentation, discharge diagnosis, suicide screening, and other mental health indicators. Univariate logistic regression was used to determine factors associated with suicide screening. Results:  The cohort of 800 patients had a median age of 41 years (interquartile range = 27 to 53 years) with 57% female, 16% Hispanic, 58% white, 23% black or African American, and 10% other race. Suicide screenings were documented for 39 patients (4.9%; 95% confidence interval [CI] = 3.4% to 6.4%). Of those screened, 23 (2.9% of total sample; 95% CI = 1.7% to 4.0%) were positive for suicidal ideation or behavior. Approximately 90% of those screened had documented complaints of a psychiatric nature at triage. About one-third had either documentation of alcohol abuse (33%) or intentional illegal or prescription drug misuse (36%). Conclusions:  The presence of known psychiatric problems and substance use had the strongest associations with suicide screening, yet even patients presenting with these indicators were not screened for suicide. Understanding factors that currently influence suicide screening in the ED will guide the design and implementation of improved suicide screening protocols and related interventions. ACADEMIC EMERGENCY MEDICINE 2012; 1-5 © 2012 by the Society for Academic Emergency Medicine.

Disassembly and Reassembly Improves Morphology and Thermal Stability of Human Papillomavirus Type 16 Virus-like Particles

Nanomedicine : Nanotechnology, Biology, and Medicine. Jan, 2012  |  Pubmed ID: 22306156

Recombinant human papillomavirus (HPV) 16 L1 protein self-assembles into virus-like particles (VLPs) with diameters of 40 to 60 nm, which are key components in prophylactic HPV vaccines. Marked improvement in morphology and thermal stability upon VLP disassembly and reassembly was demonstrated at production scale. Differential scanning calorimetry showed enhanced conformational stability as indicated by the unfolding temperatures and peak heights/areas. Cloud point studies indicated (1) a much lower propensity for post-reassembly VLPs to aggregate during a time course study and (2) much higher cloud point temperatures. In-solution atomic force microscopy showed more uniform size distribution and fully closed particles, with evidence of virion-like assembly revealed by the structural details from a single particle image. Similar approaches for the reassembly of other recombinant VLPs with intrinsic conformational switches would be expected to improve the particle properties and render nanoparticles more suitable for use as vaccines or therapeutics.

Draft Genome Sequence of Four Coccolithoviruses: Emiliania Huxleyi Virus EhV-88, EhV-201, EhV-207, and EhV-208

Journal of Virology. Mar, 2012  |  Pubmed ID: 22328700

The Coccolithoviridae are a group of viruses which infect the marine coccolithophorid microalga Emiliania huxleyi. The Emiliania huxleyi viruses (known as EhVs) described herein have 160- to 180-nm diameter icosahedral structures, have genomes of approximately 400 kbp, and consist of more than 450 predicted coding sequences (CDSs). Here, we describe the genomic features of four newly sequenced coccolithoviruses (EhV-88, EhV-201, EhV-207, and EhV-208) together with their draft genome sequences and their annotations, highlighting the homology and heterogeneity of these genomes to the EhV-86 model reference genome.

Rapid Acute Treatment of Agitation in Patients with Bipolar I Disorder: a Multicenter, Randomized, Placebo-controlled Clinical Trial with Inhaled Loxapine

Bipolar Disorders. Feb, 2012  |  Pubmed ID: 22329470

Kwentus J, Riesenberg RA, Marandi M, Manning RA, Allen MH, Fishman RS, Spyker DA, Kehne JH, Cassella JV. Rapid acute treatment of agitation in patients with bipolar I disorder: a multicenter, randomized, placebo-controlled clinical trial with inhaled loxapine. Bipolar Disord 2012: 14: 31-40. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S. Objective:  The present study evaluated inhaled loxapine for the acute treatment of agitation in patients with bipolar I disorder. Methods:  A Phase 3, randomized, double blind, placebo-controlled, parallel group inpatient study was performed at 17 psychiatric research facilities. Agitated patients (N = 314) with bipolar I disorder (manic or mixed episodes) were randomized (1:1:1) to inhaled loxapine 5 mg or 10 mg, or inhaled placebo using the Staccato(®) system. Following baseline assessments, patients received Dose 1 and were evaluated for 24 hours. If required, up to two additional doses of study drug and/or lorazepam rescue medication were given. The primary efficacy endpoint was change from baseline in the Positive and Negative Syndrome Scale-Excited Component (PANSS-EC) score two hours after Dose 1. The key secondary endpoint was the Clinical Global Impression-Improvement score at two hours after Dose 1. Additional endpoints included the changes from baseline in the PANSS-EC from 10 min through 24 hours after Dose 1. Safety was assessed by adverse events, vital signs, physical examinations, and laboratory tests. Results:  For the primary and key secondary endpoints, both doses of inhaled loxapine significantly reduced agitation compared with placebo. Reduced agitation, as reflected in PANSS-EC score, was evident 10 min after Dose 1 with both doses. Inhaled loxapine was well tolerated, and the most common adverse events were known effects of loxapine or minor oral effects common with inhaled medications (dysgeusia was reported in 17% of patients receiving active drug versus 6% receiving placebo). Conclusions:  Inhaled loxapine provided a rapid, non-injection, well-tolerated acute treatment for agitation in patients with bipolar I disorder.