Methylthioadenosine Phosphorylase, a Gene Frequently Codeleted with P16(cdkN2a/ARF), Acts As a Tumor Suppressor in a Breast Cancer Cell Line

Cancer Research. Nov, 2002  |  Pubmed ID: 12438261

The human methylthioadenosine phosphorylase (MTAP) gene is located on 9p21 and is frequently homozygously deleted, along with p16(cdkN2a/ARF), in a wide variety of human tumors and human tumor-derived cell lines. The function of MTAP is to salvage methylthioadenosine, which is produced as a byproduct of polyamine metabolism. We have reintroduced MTAP into MCF-7 breast adenocarcinoma cells and have examined its effect on the tumorigenic properties of these cells. MTAP expression does not affect the growth rate of cells in standard tissue culture conditions but severely inhibits their ability to form colonies in soft agar or collagen. In addition, MTAP-expressing cells are suppressed for tumor formation when implanted into SCID mice. This suppression of anchorage-independent growth appears to be because of the enzymatic activity of MTAP, as a protein with a missense mutation in the active site does not exhibit this phenotype. MTAP expression causes a significant decrease in intracellular polyamine levels and alters the ratio of putrescine to total polyamines. Consistent with this observation, the polyamine biosynthesis inhibitor alpha-difluoromethylornithine inhibits the ability of MTAP-deficient cells to form colonies in soft agar, whereas addition of the polyamine putrescine stimulates colony formation in MTAP-expressing cells. These results indicate that MTAP has tumor suppressor activity and suggest that its effects may be mediated by altering intracellular polyamine pools.

Outcomes After Aortic Valve Replacement in Patients with Severe Aortic Regurgitation and Markedly Reduced Left Ventricular Function

Circulation. Nov, 2002  |  Pubmed ID: 12438294

Left ventricular dysfunction is an indication for aortic valve replacement (AVR) in patients with severe aortic regurgitation (AR). However, the postoperative outcome of patients with severe AR and a markedly low ejection fraction (EF) is not known.

Selective Regulation of Glutamic Decarboxylase Isoform 65, but Not Isoform 67, in the Bed Nucleus of the Stria Terminalis and the Preoptic Area of the Ewe Brain Across the Estrous Cycle

Endocrinology. Feb, 2002  |  Pubmed ID: 11796509

gamma-Aminobutyric acid neurons in the preoptic area (POA) of the brain may regulate GnRH neurons. The level of expression of two isoforms (65 and 67) of glutamic acid decarboxylase (GAD) in the ewe brain was determined across the estrous cycle by in situ hybridization. GAD mRNA expression (cell number and silver grains/cell) was examined in the subdivisions of the bed nucleus of stria terminalis (BnST), in the diagonal band of Broca, and the POA. The number of cells expressing GAD(65) and GAD(67) mRNA did not change across the cycle. Within the rostro-dorsal BnST, the number of silver grains/cell for GAD(65) mRNA was lower in the follicular phase than the luteal phase or at estrus. In the rostro-lateral division, expression was lower in the follicular phase. In the POA, the number of silver grains/cell for GAD(65) mRNA was lower at estrus than during the luteal phase. The number of silver grains/cell for GAD(67) mRNA did not change across the estrous cycle. GAD(65) is thought to be the active enzyme during periods of high demand of GABA and our results are consistent with the GABA neurons of BnST being most active during the luteal phase of the estrous cycle.

S-adenosylhomocysteine, but Not Homocysteine, is Toxic to Yeast Lacking Cystathionine Beta-synthase

Molecular Genetics and Metabolism. Apr, 2002  |  Pubmed ID: 12051965

Elevated plasma homocysteine is associated with a variety of diseases in humans including coronary heart disease, stroke, peripheral vascular disease, and birth defects. However, the mechanism by which plasma homocysteine affects cells is unknown. We have examined the growth of isogenic wild-type and cystathionine beta-synthase (CBS) deficient yeast in response to homocysteine and its immediate metabolic precursor, S-adenosylhomocysteine (SAH). CBS deficient yeast export significantly more homocysteine into the media than wild-type yeast and have elevated internal pools of homocysteine and SAH. We found that 5 mM homocysteine added to the media had very little effect on the growth of wild-type or CBS deficient yeast, although intracellular homocysteine concentrations increased five- to tenfold. In contrast, as little as 25 microM S-adenosylhomocysteine inhibited the growth of CBS deficient yeast, but had no effect on wild-type yeast. Measurements of the intracellular S-adenosylmethionine (SAM) and SAH indicate that CBS deficient yeast contain reduced SAM/SAH ratios relative to wild-type, and this ratio is further reduced by adding SAH to the media. Growth inhibition by SAH in CBS deficient yeast can be totally reversed by addition of SAM to the media, indicating that the ratio and not absolute level is critical for cell growth. These results suggest that CBS plays a key role in the regulation of the SAM/SAH ratio inside cells and that excessive perturbations of this ratio can inhibit growth. We hypothesize that elevated extracellular homocysteine present in humans may reflect an altered intracellular SAM/SAH ratio and that this may be related to disease pathogenesis.

Irreversible Inhibition of the Bacterial Cysteine Protease-transpeptidase Sortase (SrtA) by Substrate-derived Affinity Labels

The Biochemical Journal. Sep, 2002  |  Pubmed ID: 12069686

We report on the first synthesis, kinetic evaluation and application of novel substrate-derived inhibitors against the Staphylococcus aureus cysteine protease-transpeptidase, sortase (staphylococcal surface protein sorting A, SrtA). The peptidyl-diazomethane and peptidyl-chloromethane analogues, Cbz (benzyloxycarbonyl)-Leu-Pro-Ala-Thr-CHN(2) (I) and Cbz-Leu-Pro-Ala-Thr-CH(2)Cl (II) respectively were found to act as time-dependent irreversible inhibitors of recombinant sortase (SrtA(DeltaN)). The peptidyl-chloromethane analogue (II) was the most powerful with an inhibitor specificity constant (k(i)/K(i)) of 5.3x10(4) M(-1).min(-1), approx. 2-fold greater than that determined for the peptidyl-diazomethane (I). Additionally, using Western-blot analysis, we have been able to demonstrate that a biotinylated version of the peptidyl-diazomethane analogue, biotin-Ahx (aminohexanoyl)-Leu-Pro-Ala-Thr-CHN(2) (III), can be used as an affinity label to detect the presence of wild-type SrtA in crude cell lysates prepared from S. aureus.

Atrial Fibrillation Complicating the Course of Degenerative Mitral Regurgitation: Determinants and Long-term Outcome

Journal of the American College of Cardiology. Jul, 2002  |  Pubmed ID: 12103260

The study was done to define the incidence, determinants and prognostic implications of onset of atrial fibrillation (AF) during follow-up of mitral regurgitation (MR) initially in sinus rhythm.

A Randomized Trial of Three Diabetes Registry Implementation Strategies in a Community Internal Medicine Practice

The Joint Commission Journal on Quality Improvement. Aug, 2002  |  Pubmed ID: 12174408

Disease registries are powerful tools with the potential to transform the way chronic diseases are managed. To date, however, little work has been done to determine how to optimize the implementation of a chronic disease registry in practice.

Long-term Prognosis of Patients with Clinical Unstable Angina Pectoris Without Elevation of Creatine Kinase but with Elevation of Cardiac Troponin I Levels

The American Journal of Cardiology. Oct, 2002  |  Pubmed ID: 12372578

Determinants of Patient Satisfaction in Chronic Illness

Arthritis and Rheumatism. Oct, 2002  |  Pubmed ID: 12382297

To determine whether primary care provided by generalists versus subspecialists resulted in different levels of patient satisfaction among persons with chronic illness.

Effect of Choice of Surgical Gloves on Dough Time Measurements of Acrylic Bone Cement

Biomaterials. Jan, 2003  |  Pubmed ID: 12419623

In this study we investigated the effect of the brand of surgical gloves on the dough time determination for acrylic bone cements. Four different brands of powder-free latex surgical gloves were tested. Two commercial bone cements, Surgical Simplex P and Palacos R, were used for dough time measurement following standard test methods for acrylic bone cements (ASTM F-451 and ISO 5833). The results show that the measured dough time depended largely on the brand of gloves used, and could vary by nearly 250%. The surface morphological structures of gloves, determined by SEM, probably contribute to the differences in the measured dough time. This study provides experimental evidence that supports the need to describe the type of gloves used, in detail, when dough time is reported. It also illustrates the importance of the glove brand, when bone cement is to be handled as a dough in the clinical setting.

Antibiotic Bone Cement for the Treatment of Pseudomonas Aeruginosa in Joint Arthroplasty: Comparison of Tobramycin and Gentamicin-loaded Cements

Journal of Biomedical Materials Research. Part B, Applied Biomaterials. Feb, 2003  |  Pubmed ID: 12516083

One hundred clinical isolates of Pseudomonas aeruginosa were collected from 22 medical centers throughout Europe and were challenged with two aminoglycoside-loaded bone cements, employing a modified in vitro Kirby-Bauer susceptibility model. The results of this study show that Simplex P with tobramycin exhibits antibacterial activity against 98% of the strains tested, compared to 93% for Palacos with gentamicin. Additionally, for strains that were susceptible to the antibiotic bone cement formulations, the average zone of inhibition produced around the tobramycin-loaded cement disks was approximately 25% greater than that seen around the gentamicin-loaded cement disks. This difference was statistically significant (p < 0.01). Tobramycin-loaded bone cement is therefore the preferred formulation when addressing Pseudomonas aeruginosa in septic joint arthroplasty.

Unloading-induced Remodeling in the Normal and Hypertrophic Left Ventricle

American Journal of Physiology. Heart and Circulatory Physiology. Jun, 2003  |  Pubmed ID: 12573997

To date, no study has assessed the degree of similarity between left ventricular (LV) reverse remodeling and atrophic remodeling. Stable LV hypertrophy was induced by creation of an arteriovenous fistula (AVF) in Lewis rats (32 days). LV unloading was induced by heterotopic transplantation of normal (NL-HT) and/or hypertrophic (AVF-HT) hearts (7 days). We compared indexes of remodeling in AVF, NL-HT, and AVF-HT groups with those of normal controls. LV unloading induced decreases in cardiomyocyte size in NL-HT and AVF-HT hearts. NL-HT and AVF-HT LV were both characterized by relative increases in collagen concentration that were largely a reflection of decreases in myocyte volume. NL-HT and AVF-HT LV were associated with similar increases in matrix metalloproteinase (MMP-2 and -9) zymographic activity, without change in the abundance of the tissue inhibitors of the MMPs. In contrast, AVF-HT, but not NL-HT, was associated with a dramatic increase in collagen cross-linking. Our findings suggest an overall similarity in the response of the normal and hypertrophic LV to surgical unloading. However, the dramatic increase in collagen cross-linking after just 1 wk of unloading suggests a potential difference in the dynamics of collagen metabolism between the two models. Further studies will be required to determine the precise molecular mechanisms responsible for these differences in extracellular matrix regulation. However, with respect to these and related issues, heterotopic transplantation of hypertrophied hearts will be a useful small animal model for defining mechanisms of myocyte-matrix interactions during decreased loading conditions.

Neuronal Inputs from the Hypothalamus and Brain Stem to the Medial Preoptic Area of the Ram: Neurochemical Correlates and Comparison to the Ewe

Biology of Reproduction. Apr, 2003  |  Pubmed ID: 12606458

The retrograde tracer, FluoroGold, was used to trace the neuronal inputs from the septum, hypothalamus, and brain stem to the region of the GnRH neurons in the rostral preoptic area of the ram and to compare these imputs with those in the ewe. Sex differences were found in the number of retrogradely labeled cells in the dorsomedial and ventromedial nuclei. Retrogradely labeled cells were also observed in the lateral septum, preoptic area, organum vasculosum of the lamina terminalis, bed nucleus of the stria terminalis, stria terminalis, subfornical organ, periventricular nucleus, anterior hypothalamic area, lateral hypothalamus, arcuate nucleus, and posterior hypothalamus. These sex differences may partially explain sex differences in how GnRH secretion is regulated. Fluorescence immunohistochemistry was used to determine the neurochemical identity of some of these cells in the ram. Very few tyrosine hydroxylase-containing neurons in the A14 group (<1%), ACTH-containing neurons (<1%), and neuropeptide Y-containing neurons (1-5%) in the arcuate nucleus contained FluoroGold. The ventrolateral medulla and parabrachial nucleus contained the main populations of FluoroGold-containing neurons in the brain stem. Retrogradely labeled neurons were also observed in the nucleus of the solitary tract, dorsal raphe nucleus, and periaqueductal gray matter. Virtually all FluoroGold-containing cells in the ventrolateral medulla and about half of these cells in the nucleus of the solitary tract also stained for dopamine beta-hydroxylase. No other retrogradely labeled cells in the brain stem were noradrenergic. Although dopamine, beta-endorphin, and neuropeptide Y have been implicated in the regulation of GnRH secretion in males, it is unlikely that these neurotransmitters regulate GnRH secretion via direct inputs to GnRH neurons.

Cerebral Ischemic Events After Diagnosis of Mitral Valve Prolapse: a Community-based Study of Incidence and Predictive Factors

Stroke; a Journal of Cerebral Circulation. Jun, 2003  |  Pubmed ID: 12738894

Association of mitral valve prolapse (MVP) with ischemic neurological events (INEs) is uncertain.

Left Ventricular Remodeling After Valve Replacement in Patients with Isolated Aortic Regurgitation

Circulation. Jun, 2003  |  Pubmed ID: 12796419

Sequential Assessment of Mitral Valve Area During Diastole Using Colour M-mode Flow Convergence Analysis: New Insights into Mitral Stenosis Physiology

European Heart Journal. Jul, 2003  |  Pubmed ID: 12831819

In mitral stenosis (MS) transvalvular flow and velocity continually change throughout diastole but for mitral valve area (MVA), flow-dependent variations (valve reserve) are unknown. These physiologic changes can be studied by the proximal isovelocity surface area (PISA) method, using the high temporal resolution of colour M-mode, essential for simultaneous measurements of flow and velocity. Hence, we aimed to validate the colour M-mode PISA method for measurement of MVA in MS and to define using this method the physiologic flow-dependent changes of MVA during diastole.

Comparison of Frequency of Recurrent Syncope After Beta-blocker Therapy Versus Conservative Management for Patients with Vasovagal Syncope

The American Journal of Cardiology. Jul, 2003  |  Pubmed ID: 12842256

Evidence for Estrogenic Regulation of Gonadotropin-releasing Hormone Neurons by Glutamatergic Neurons in the Ewe Brain: An Immunohistochemical Study Using an Antibody Against Vesicular Glutamate Transporter-2

The Journal of Comparative Neurology. Oct, 2003  |  Pubmed ID: 12926021

Gonadotropin-releasing hormone (GnRH) secretion is controlled by various factors, including the excitatory neurotransmitter glutamate. Estrogen (E) regulates GnRH secretion by means of E-responsive cells in the brain that relay the feedback effects to the preoptic area (POA). We used an antibody to vesicular glutamate transporter 2 (VGluT2) to label glutamatergic neurons in the areas of the ewe brain that control GnRH secretion. VGluT2-immunoreactive cells were observed in the arcuate nucleus (ARC)/ventromedial hypothalamic nucleus (VMH) complex, POA, bed nucleus of stria terminalis (BnST), and A1 and A2 cell groups in the brainstem. In three ewes, E receptor-alpha was detected in 52-61% of glutamatergic neurons in ARC/VMH, 37-52% of neurons in the POA, and 37-58% of neurons in the BnST. E injection (i.m. or i.v.) increased the percentage of glutamatergic cells that expressed Fos protein in the ARC (P < 0.01 and P < 0.001, respectively). In six ewes, injection of the retrograde tracer Fluoro-Gold into the POA labeled cells in the ARC and 6-29% of these were also VGluT2-immunoreactive. Double-labeling of varicosities in the POA showed colocalization of VGluT2 in 12.5 +/- 3% of dopamine beta-hydroxylase-immunoreactive terminals, indicating that a subset of glutamatergic inputs could arise from brainstem noradrenergic neurons cells. In the POA, 60% of GnRH neurons had close appositions that were VGluT2-immunoreactive. We conclude that E-responsive glutamatergic neurons arising from the brainstem, the BnST, and ARC/VMH provide input to the POA and may be involved in the regulation of GnRH secretion.

Effect of Testosterone and Season on Proenkephalin Messenger RNA Expression in the Preoptic Area of the Hypothalamus in the Ram

Biology of Reproduction. Dec, 2003  |  Pubmed ID: 12930728

Enkephalin appears to exert an inhibitory action on LH secretion, but whether testosterone regulates enkephalin gene expression is unknown. This study tested the hypothesis that testosterone and/or season modulate preproenkephalin mRNA expression in specific areas of the hypothalamus. Romney Marsh rams were castrated (wethers) either during the breeding season or nonbreeding season and received intramuscular injections of either oil or testosterone propionate (five/group). Blood samples were taken for the assay of plasma LH and testosterone. Preproenkephalin mRNA expression was quantified in hypothalamic sections by in situ hybridization. Mean plasma LH concentrations were reduced and the interpulse interval for LH pulses was greater in testosterone propionate-treated wethers compared with oil-treated wethers, with no change in LH pulse amplitude. Testosterone propionate treatment reduced proenkephalin expression in the diagonal band of Broca, the caudal preoptic area, and the bed nucleus of the stria terminalis. Seasonal differences in proenkephalin expression were observed in the bed nucleus of the stria terminalis, lateral septum, periventricular nucleus, and paraventricular nucleus. No differences were observed between treatments in seven other regions examined. We conclude that testosterone and season regulate proenkephalin mRNA levels in the preoptic area/hypothalamus in the ram in a region-specific manner.

Preventive Medical Services Among Patients with Rheumatoid Arthritis

The Journal of Rheumatology. Sep, 2003  |  Pubmed ID: 12966594

To assess the degree to which patients with rheumatoid arthritis (RA) receive health maintenance and preventive care procedures recommended by the United States Preventive Services Task Force (USPSTF), a government appointed independent expert panel whose recommendations are based on a systematic review of the evidence of effectiveness of clinical preventive services.

Mixing of Acrylic Bone Cement: Effect of Oxygen on Setting Properties

Biomaterials. Dec, 2003  |  Pubmed ID: 14559018

The present study investigates the effect of different mixing methods on the setting properties of bone cement. It was found that vacuum mixing decreased the setting time of the bone cement by nearly 2 min (10%), compared to mixing in air. Two additional experiments, in which the bone cement powders were purged with argon or oxygen, and mixed with the methyl methacrylate monomer, revealed that oxygen concentrations in the bone cement had a great effect on the setting time. The setting time increases significantly as the oxygen concentration increases, which suggests that the decrease in the setting time by vacuum mixing may be attributed to the lower oxygen levels present in the mixer. No significant effect was observed on dough time or maximum exothermic temperature by varying oxygen concentrations in the bone cement mixer.

The Strength of Acrylic Bone Cement Cured Under Thumb Pressure

Biomaterials. Feb, 2004  |  Pubmed ID: 14609683

In this investigation, the static tensile strength of bone cement was quantified after mixing it in an open bowl or in a commercially available vacuum mixer and molding it under pressures consistent with values obtained by finger/digital application, as it is used in surgery. Pressure, held for a brief time span on cement in its lower viscosity state, has been demonstrated to increase penetration of the cement into bone. Clinically, bone cement is pressurized by digital pressure, specialized instruments, or by implant design. Specimens were cured under constant pressures of up to 100kPa, which is in the range reported for thumb pressurization of plugged proximal femurs and instrumented pressurization of acetabular sockets. The results showed that application of constant pressure during the polymerization of open bowl mixed bone cement significantly improved its mechanical properties. Application of 100kPa constant pressure to the open bowl mixed bone cement while it cured increased its ultimate strength to a value similar to vacuum mixed cement. Curing under pressure showed no significant effect on the tensile properties of vacuum mixed cement. Curing under pressure did not significantly reduce the size of the largest pores in the tensile specimens.

Do Complication Screening Programs Detect Complications Present at Admission?

Joint Commission Journal on Quality and Safety. Mar, 2004  |  Pubmed ID: 15032070

A study was undertaken to verify the accuracy of computer algorithms on administrative data to identify hospital complications. The assessment was based on a medical records indicator that differentiated hospital-acquired conditions from preexisting comorbidities.

Kaposi's Sarcoma-associated Herpesvirus K7 Protein Targets a Ubiquitin-like/ubiquitin-associated Domain-containing Protein to Promote Protein Degradation

Molecular and Cellular Biology. May, 2004  |  Pubmed ID: 15082787

Pathogens exploit host machinery to establish an environment that favors their propagation. Because of their pivotal roles in cellular physiology, protein degradation pathways are common targets for viral proteins. Protein-linking integrin-associated protein and cytoskeleton 1 (PLIC1), also called ubiquilin, contains an amino-terminal ubiquitin-like (UBL) domain and a carboxy-terminal ubiquitin-associated (UBA) domain. PLIC1 is proposed to function as a regulator of the ubiquitination complex and proteasome machinery. Kaposi's sarcoma-associated herpesvirus (KSHV) contains a small membrane protein, K7, that protects cells from apoptosis induced by various stimuli. We report here that cellular PLIC1 is a K7-interacting protein and that the central hydrophobic region of K7 and the carboxy-terminal UBA domain of PLIC1 are responsible for their interaction. Cellular PLIC1 formed a dimer and bound efficiently to polyubiquitinated proteins through its carboxy-terminal UBA domain, and this activity correlated with its ability to stabilize cellular I kappa B protein. In contrast, K7 interaction prevented PLIC1 from forming a dimer and binding to polyubiquitinated proteins, leading to the rapid degradation of I kappa B. Furthermore, K7 expression promoted efficient degradation of the p53 tumor suppressor, resulting in inhibition of p53-mediated apoptosis. These results indicate that KSHV K7 targets a regulator of the ubiquitin- and proteasome-mediated degradation machinery to deregulate cellular protein turnover, which potentially provides a favorable environment for viral reproduction.

Evaluation and Clinical Implications of Aortic Valve Calcification Measured by Electron-beam Computed Tomography

Circulation. Jul, 2004  |  Pubmed ID: 15249504

Electron-beam computed tomography (EBCT) is used to measure coronary calcification but not for aortic valve calcification (AVC). Its accuracy, association with aortic stenosis (AS) severity, and diagnostic and prognostic value with respect to AVC are unknown.

Medical and Surgical Outcome of Tricuspid Regurgitation Caused by Flail Leaflets

The Journal of Thoracic and Cardiovascular Surgery. Aug, 2004  |  Pubmed ID: 15282468

We sought to evaluate the medical and surgical outcome of tricuspid regurgitation caused by flail leaflets.

Methylene Blue Enhancement of Resuscitation After Refractory Hemorrhagic Shock

The Journal of Trauma. Sep, 2004  |  Pubmed ID: 15454796

Methylene blue has been used to treat hypovolemic states. This study evaluated prehospital resuscitation after refractory hemorrhagic shock with a combination of methylene blue and limited-volume lactated Ringer's solution.

Atrial Fibrillation After Surgical Correction of Mitral Regurgitation in Sinus Rhythm: Incidence, Outcome, and Determinants

Circulation. Oct, 2004  |  Pubmed ID: 15477410

The incidence, determinants, and outcome of postoperative atrial fibrillation (AF) after surgery for mitral regurgitation (MR) are poorly defined but may have important implications for timing of mitral valve surgery.

Addition of Hand-blended Generic Tobramycin in Bone Cement: Effect on Mechanical Strength

Orthopedics. Dec, 2004  |  Pubmed ID: 15633960

This study compared the mechanical strength of commercially prepared antibiotic bone cement (Simplex With Tobramycin; Stryker, Mahwah, NJ), cement with generic tobramycin (Pharma-Tek, Huntington, NY) blended in by the orthopedic nursing staff, and standard nonantibiotic bone cement. The results showed an approximate 36% decrease in the strength of the cement with hand-mixed generic tobramycin, while the commercial antibiotic cement remained unchanged relative to the nonantibiotic control. These results indicate the mechanical properties of bone cement can be severely compromised by hand-mixing antibiotics into bone cement at the time of surgery.

Contribution of Ischemic Mitral Regurgitation to Congestive Heart Failure After Myocardial Infarction

Journal of the American College of Cardiology. Jan, 2005  |  Pubmed ID: 15653025

The purpose of this study was to define the contribution of ischemic mitral regurgitation (IMR) to the occurrence of congestive heart failure (CHF) after myocardial infarction (MI).

The Structural Organization of Aurein Precursor CDNAs from the Skin Secretion of the Australian Green and Golden Bell Frog, Litoria Aurea

Regulatory Peptides. May, 2005  |  Pubmed ID: 15721491

Aureins are a family of peptides (13-25 residues), some of which possess potent antimicrobial and anti-cancer properties, which have been classified into 5 subgroups based upon primary structural similarities. They were originally isolated from the defensive skin secretions of the closely related Australian bell frogs, Litoria aurea and Litoria raniformis, and of the 23 aurein peptides identified, 10 are common to both species. Using a recently developed technique, we have constructed a cDNA library from the defensive secretion of the green and golden bell frog, L. aurea, and successfully cloned a range of aurein precursor transcripts containing entire open-reading frames. All open-reading frames consisted of a putative signal peptide and an acidic pro-region followed by a single copy of aurein. The deduced precursor structures for the most active aureins (2.2 and 3.1) confirmed the presence of a C-terminal amidation motif whereas that of aurein 5.3 did not. Processed peptides corresponding in molecular mass to aureins 2.2, 2.3, 2.5, 3.1 and 5.3 were identified in the same secretion sample using LC/MS. The application of this technique thus permits parallel peptidomic and transcriptomic analyses on the same lyophilized skin secretion sample circumventing sacrifice of specimens of endangered herpetofauna.

Quantitative Determinants of the Outcome of Asymptomatic Mitral Regurgitation

The New England Journal of Medicine. Mar, 2005  |  Pubmed ID: 15745978

The clinical outcome of asymptomatic mitral regurgitation is poorly defined, and the treatment is uncertain. We studied the effect on the outcome of quantifying mitral regurgitation according to recent guidelines.

Direct and Indirect Calorimetry of Lactate Oxidation: Implications for Whole-body Energy Expenditure

Journal of Sports Sciences. Jan, 2005  |  Pubmed ID: 15841591

Whole-body energy expenditure for heavy/severe exercise is currently accounted for by either: (1) anaerobic and oxygen uptake measures during exercise where recovery energy expenditure is omitted; or (2) oxygen uptake during, and an EPOC (excess post-exercise oxygen consumption), measure following exercise where substrate level phosphorylation during exercise is considered part of EPOC. Simultaneous direct/indirect calorimetry enabled us to determine if a thermodynamic reversal (i.e. heat consumption) takes place as the highly exothermic pyruvate to lactate reaction proceeds in the opposite direction. Reversibility implies that oxygen uptake (e.g. EPOC) can indeed account for rapid glycolytic ATP production regardless if lactate is formed or not (e.g. 1.2 g glucose catabolism = 20.9 kJ x l O2(-1)). Cultured hybrid cells and mouse cardiac muscle fibres were utilized in simultaneous calorimetry and respirometry experiments where pyruvate or lactate was predominantly oxidized. The calorimetric to respiratory ratio was determined using heat flux (pW x cell(-1)) and oxygen flux (pmol x s(-1) cell(-1)) measures. Ten cell experiments gave calorimetric to respiratory ratios that showed no statistical difference (P= 0.97) whether cells respired predominantly on lactate (-516+/-53 kJ x mol O2(-1)) or pyruvate (- 517+/-89 kJ x mol O2(-1)). In three cardiac preparations, the calorimetric to respiratory ratio was -502+/-15 kJ x mol O2(-1) for lactate and -506+/-47 kJ x mol O2(-1) for pyruvate, again a non-significant difference (P= 0.91). Heat consumption did not occur during lactate oxidation. These results suggest that rapid glycolytic ATP and lactate production, and lactate oxidation, are both independently associated with heat production and thus represent separate and additive components to the measurement of total energy expenditure for exercise and recovery.

The Angiotensin II Type 2 Receptor and Improved Adjacent Region Function Post-MI

Journal of Cardiovascular Magnetic Resonance : Official Journal of the Society for Cardiovascular Magnetic Resonance. 2005  |  Pubmed ID: 15881529

Angiotensin II type 2 receptor (AT2-R) overexpression in the mouse heart preserves left ventricular (LV) size and global LV function during post-MI remodeling. We hypothesized that CMR tagging would localize regional improvements in myocardial function during post-MI remodeling in AT2-R cardiac overexpressed transgenic mice (TG), which could explain the preservation of global LV function post-MI. Six male wild-type (WT) C57BL/6 mice and 10 TG mice were studied by CMR at baseline (day 0) and days 1, 7, and 28 post-MI. MI was induced by 1 hour occlusion of the LAD followed by reperfusion. On day 1 post-MI, gadolinium-DTPA was injected to assess infarct size. LV size and function was assessed by cine CMR. Mean % circumferential shortening (%CS) was calculated within infarcted, adjacent, and remote regions at each time point in WT and TG mice. Quantitative interstitial collagen and mean myocyte cross-sectional area was measured postmortem at day 28 post-MI. LV end-systolic volume was lower and ejection fraction higher at baseline in the TG group and these differences were maintained post-MI. Within infarcted and remote zones, although %CS was higher in TG mice at day 0, there was no difference by day 28 between groups. Within adjacent regions, while there was no difference at day 0 or 1 in TG vs. WT, %CS was significantly higher in TG mice by day 7, and these changes persisted out to day 28 post-MI. Regional interstitial collagen and myocyte size were similar between groups. Thus, myocardial tagging can detect regional differences in contractile function post-MI in TG mice, and AT2-R overexpression is associated with improved contractile function in adjacent noninfarcted myocardium.

B-type Natriuretic Peptide in Organic Mitral Regurgitation: Determinants and Impact on Outcome

Circulation. May, 2005  |  Pubmed ID: 15883225

B-type natriuretic peptide (BNP) activation observed in cardiac diseases is a predictor of poor outcome; however, in organic mitral regurgitation (MR), BNP determinants and prognostic value are unknown.

Irregular Cycles and Steroid Hormones in Polycystic Ovary Syndrome

Human Reproduction (Oxford, England). Sep, 2005  |  Pubmed ID: 15932911

This cross-sectional study was undertaken to evaluate the factors that relate to menstrual status (oligo-amenorrhoea versus eumenorrhoea) in polycystic ovary syndrome (PCOS).

Outcome of 622 Adults with Asymptomatic, Hemodynamically Significant Aortic Stenosis During Prolonged Follow-up

Circulation. Jun, 2005  |  Pubmed ID: 15956131

This study assessed the long-term outcome of a large, asymptomatic population with hemodynamically significant aortic stenosis (AS).

Contribution of Anaerobic Energy Expenditure to Whole Body Thermogenesis

Nutrition & Metabolism. Jun, 2005  |  Pubmed ID: 15958171

Heat production serves as the standard measurement for the determination of energy expenditure and efficiency in animals. Estimations of metabolic heat production have traditionally focused on gas exchange (oxygen uptake and carbon dioxide production) although direct heat measurements may include an anaerobic component particularly when carbohydrate is oxidized. Stoichiometric interpretations of the ratio of carbon dioxide production to oxygen uptake suggest that both anaerobic and aerobic heat production and, by inference, all energy expenditure--can be accounted for with a measurement of oxygen uptake as 21.1 kJ per liter of oxygen. This manuscript incorporates contemporary bioenergetic interpretations of anaerobic and aerobic ATP turnover to promote the independence of these disparate types of metabolic energy transfer: each has different reactants and products, uses dissimilar enzymes, involves different types of biochemical reactions, takes place in separate cellular compartments, exploits different types of gradients and ultimately each operates with distinct efficiency. The 21.1 kJ per liter of oxygen for carbohydrate oxidation includes a small anaerobic heat component as part of anaerobic energy transfer. Faster rates of ATP turnover that exceed mitochondrial respiration and that are supported by rapid glycolytic phosphorylation with lactate production result in heat production that is independent of oxygen uptake. Simultaneous direct and indirect calorimetry has revealed that this anaerobic heat does not disappear when lactate is later oxidized and so oxygen uptake does not adequately measure anaerobic efficiency or energy expenditure (as was suggested by the "oxygen debt" hypothesis). An estimate of anaerobic energy transfer supplements the measurement of oxygen uptake and may improve the interpretation of whole-body energy expenditure.

Chasing a Cellular Fountain of Youth

Nature Biotechnology. Jul, 2005  |  Pubmed ID: 16003362

Eyelid Schwannoma in a Male Adult

Clinical & Experimental Ophthalmology. Aug, 2005  |  Pubmed ID: 16033357

Schwannomas (neurilemmomas) are benign tumours of peripheral nerves arising from Schwann cells. These tumours along with neurofibromas form the two most common primary peripheral nerve tumours. Solitary lesions can occur sporadically in the general population but multiple neurofibromas are distinctive feature of neurofibromatosis type 1 and bilateral acoustic schwannomas are a feature of neurofibromatosis type 2. Schwannomas of ophthalmic interest are rare although they have been reported in relation to the orbit, and infrequently uveal tract and conjunctiva. Isolated eyelid schwannomas appear infrequent; only four cases in adults and one in a child in the published literature have been found. Herein, a case of eyelid schwannoma in a 53-year-old man is described.

The Zinc Finger Nuclease Monopoly

Nature Biotechnology. Aug, 2005  |  Pubmed ID: 16082353

PCOS: an Ovarian Disorder That Leads to Dysregulation in the Hypothalamic-pituitary-adrenal Axis?

European Journal of Obstetrics, Gynecology, and Reproductive Biology. Jan, 2005  |  Pubmed ID: 15596265

This review focuses on the role of the ovaries in the pathogenesis of the polycystic ovarian syndrome. In particular, the failure of follicular development, hypothalamo-pituitary dysregulation, alterations in adrenal steroid output and derangement of intermediary metabolism are discussed in the context of the ovaries. It is concluded that the central and adrenal alterations associated with PCOS are unlikely to be primary but rather are secondary to the events within the ovary.

Antibody Conjugates and Therapeutic Strategies

Molecular Interventions. Dec, 2005  |  Pubmed ID: 16394252

Immunotherapeutics represent the largest group of molecules currently in development as new drug entities. These versatile molecules are being investigated for the treatment of a range of pathological conditions including cancer, infectious and inflammatory diseases. Antibodies can be used to exert biological effects themselves or as delivery agents of conjugated drug molecules. Site-specific delivery of therapeutic agents has been an ultimate goal of the pharmaceutical industry in order to maximize drug action and minimize side effects. Antibodies have the potential to realize this objective and in this review we will examine some of the main strategies currently being employed for the development of these diverse therapeutic molecules.

Misconceptions About Aerobic and Anaerobic Energy Expenditure

Journal of the International Society of Sports Nutrition. 2005  |  Pubmed ID: 18500953

The measurement of gas exchange has played an invaluable role in metabolic interpretation. The uptake of 1 liter of oxygen is often converted into an energy expenditure estimate of 21.1 kilojoules (e.g., 1 L O2 = 21.1 kJ or ~5 kcal). This article demonstrates both the importance of such a conversion and the potential for misinterpretation. Oxygen uptake during heavy and severe exercise will also be discussed.

The Problem with Potency

Nature Biotechnology. Sep, 2005  |  Pubmed ID: 16151384

Effects of Osteogenic Inducers on Cultures of Canine Mesenchymal Stem Cells

American Journal of Veterinary Research. Oct, 2005  |  Pubmed ID: 16273904

To examine age-related efficacy of bone morphogenetic protein (BMP)-2, ascorbate, and dexamethasone as osteogenic inducers in canine marrow-derived stromal cells (MSCs).

Early Puberty and Adolescent Pregnancy: the Influence of Alcohol Use

Pediatrics. Dec, 2005  |  Pubmed ID: 16322170

Early pubertal timing predicts deleterious outcomes for young girls, including substance use, risky sexual behavior, and pregnancy. In turn, adolescent pregnancy predicts long-term negative consequences such as reduced educational attainment and income-earning potential. Despite evidence of the direct links between early puberty and negative outcomes, this study is the first to examine the role that alcohol plays in the timing of sexual intercourse and pregnancy among early-maturing females.

Differences in Oxygen Uptake but Equivalent Energy Expenditure Between a Brief Bout of Cycling and Running

Nutrition & Metabolism. 2006  |  Pubmed ID: 16390548

We examined aerobic and anaerobic exercise energy expenditure and excess post-exercise oxygen consumption (EPOC) between a 250 Watt, 1-minute bout of cycling and uphill treadmill running.

Skin Problems Related to the Occupation of Commercial Fishing in North Carolina

North Carolina Medical Journal. Jul-Aug, 2006  |  Pubmed ID: 17066654

Commercial fishing is one of the most dangerous professions with many of the occupational health problems related to the skin. This study elucidates the types of occupational skin disorders that occur in commercial fishermen in North Carolina. STUDY DESIGN/SETTINGS: Booths were set up offering free skin cancer screenings at various seafood festivals, a "blessing of the fleet" event and commercial fishing shows, which were located throughout eastern North Carolina from 2002-2004. When commercial fishermen were screened, they were asked about significant skin problems that they had experienced and were related to their occupation. They were specifically asked about their history of (1) cancerous and precancerous skin lesions, (2) eczemas, (3) superficial fungal infections, (4) bacterial infections of the skin, (5) traumatic injuries related to the skin, (6) bites and stings, (7) shocks from fish, and (8) skin problems related to environmental extremes.

The Idd4 Locus Displays Sex-specific Epistatic Effects on Type 1 Diabetes Susceptibility in Nonobese Diabetic Mice

Diabetes. Dec, 2006  |  Pubmed ID: 17130511

The nonobese diabetic (NOD) mouse recapitulates many aspects of the pathogenesis of type 1 diabetes in humans, including inheritance as a complex trait. More than 20 Idd loci have been linked to type 1 diabetes susceptibility in NOD mice. Previously, we used linkage analysis of NOD crossed to the nonobese diabetes-resistant (NOR) strain and NOD congenic strains to map susceptibility to both spontaneous and cyclophosphamide-accelerated type 1 diabetes to the Idd4 locus on chromosome 11 that displayed a sex-specific effect on diabetes susceptibility. Here, we elucidate the complex genetic architecture of Idd4 by analysis of congenic strains on the NOD and NOR backgrounds. We previously refined Idd4.1 to 1.4 Mb and demonstrated an impact of this interval on type 1 interferon pathways in antigen-presenting cells. Here, we identify a second subregion, the 0.92 Mb Idd4.2 locus located telomeric to Idd4.1. Strikingly, Idd4.2 displayed a sex-specific, epistatic interaction with Idd4.1 in NOR.NOD congenic females that was not observed in syngenic males. Idd4.2 contains 29 genes, and promising candidates for the Idd4.2 effect on type 1 diabetes are described. These data demonstrate sex-dependent interaction effects on type 1 diabetes susceptibility and provide a framework for functional analysis of Idd4.2 candidate genes.

Molecular Genetic Analysis of the Idd4 Locus Implicates the IFN Response in Type 1 Diabetes Susceptibility in Nonobese Diabetic Mice

Journal of Immunology (Baltimore, Md. : 1950). Mar, 2006  |  Pubmed ID: 16493056

High-resolution mapping and identification of the genes responsible for type 1 diabetes (T1D) has proved difficult because of the multigenic etiology and low penetrance of the disease phenotype in linkage studies. Mouse congenic strains have been useful in refining Idd susceptibility loci in the NOD mouse model and providing a framework for identification of genes underlying complex autoimmune syndromes. Previously, we used NOD and a nonobese diabetes-resistant strain to map the susceptibility to T1D to the Idd4 locus on chromosome 11. Here, we report high-resolution mapping of this locus to 1.4 megabases. The NOD Idd4 locus was fully sequenced, permitting a detailed comparison with C57BL/6 and DBA/2J strains, the progenitors of T1D resistance alleles found in the nonobese diabetes-resistant strain. Gene expression arrays and quantitative real-time PCR were used to prioritize Idd4 candidate genes by comparing macrophages/dendritic cells from congenic strains where allelic variation was confined to the Idd4 interval. The differentially expressed genes either were mapped to Idd4 or were components of the IFN response pathway regulated in trans by Idd4. Reflecting central roles of Idd4 genes in Ag presentation, arachidonic acid metabolism and inflammation, phagocytosis, and lymphocyte trafficking, our combined analyses identified Alox15, Alox12e, Psmb6, Pld2, and Cxcl16 as excellent candidate genes for the effects of the Idd4 locus.

Cathepsin S Expression: An Independent Prognostic Factor in Glioblastoma Tumours--A Pilot Study

International Journal of Cancer. Journal International Du Cancer. Aug, 2006  |  Pubmed ID: 16550604

Cysteine proteinases have been implicated in astrocytoma invasion. We recently demonstrated that cathepsin S (CatS) expression is up-regulated in astrocytomas and provided evidence for a potential role in astrocytoma invasion (Flannery et al., Am J Path 2003;163(1):175-82). We aimed to evaluate the significance of CatS in human astrocytoma progression and as a prognostic marker. Frozen tissue homogenates from 71 patients with astrocytomas and 3 normal brain specimens were subjected to ELISA analyses. Immunohistochemical analysis of CatS expression was performed on 126 paraffin-embedded tumour samples. Fifty-one astrocytoma cases were suitable for both frozen tissue and paraffin tissue analysis. ELISA revealed minimal expression of CatS in normal brain homogenates. CatS expression was increased in grade IV tumours whereas astrocytoma grades I-III exhibited lower values. Immunohistochemical analysis revealed a similar pattern of expression. Moreover, high-CatS immunohistochemical scores in glioblastomas were associated with significantly shorter survival (10 vs. 5 months, p = 0.014). With forced inclusion of patient age, radiation dose and Karnofsky score in the Cox multivariate model, CatS score was found to be an independent predictor of survival. CatS expression in astrocytomas is associated with tumour progression and poor outcome in glioblastomas. CatS may serve as a useful prognostic indicator and potential target for anti-invasive therapy.

Association of B-type Natriuretic Peptide Activation to Left Ventricular End-systolic Remodeling in Organic and Functional Mitral Regurgitation

The American Journal of Cardiology. Apr, 2006  |  Pubmed ID: 16563910

B-type natriuretic peptide (BNP) is activated with mitral regurgitation (MR), but it is unclear whether BNP activation is uniform in organic and functional MR and whether it merely reflects symptoms or is a biomarker of left ventricular (LV) geometric and functional alterations. Comprehensive Doppler echocardiography and hormonal measurements were performed prospectively in 99 patients, 50 with organic MR, 28 with functional MR (with similar LV enlargement 130 +/- 21 vs 141 +/- 40, p = 0.18, and age 64 +/- 13 vs 66 +/- 12 years, p = 0.56) and 21 controls subjects of similar age. Compared with the controls, the patients with MR displayed LV remodeling and BNP activation. In those with functional MR compared with those with organic MR, despite a lower regurgitant volume (25 +/- 25 vs 96 +/- 29 ml), higher BNP levels were noted (385 +/- 388 vs 70 +/- 97 pg/ml, p <0.0001), even after stratification by functional class (class I 120 +/- 122 vs 33 +/- 40, class II 318 +/- 470 vs 74 +/- 69, class III to IV 487 +/- 383 vs 268 +/- 165 pg/ml, p = 0.006). The major determinant of BNP activation was the LV end-systolic volume index (p <0.0001), independent of MR etiology, symptoms, other hormonal activation, and hemodynamic characteristics. The BNP level is a biomarker of LV alteration in patients with MR, independent of MR etiology. With BNP >90 pg/ml, the odds ratio of an end-systolic volume index value of >/=60 ml/m(2) was 16 (95% confidence interval 5.5 to 45). In conclusion, BNP activation with MR is more pronounced in those with functional than those with organic MR, even after stratification for functional class, and independently reflects the severity of the LV alteration. Pronounced BNP activation is linked to a higher end-systolic volume index, for which it is a biomarker, irrespective of MR etiology and symptoms.

The Paths Around Stem Cell Intellectual Property

Nature Biotechnology. Apr, 2006  |  Pubmed ID: 16601720

Can new approaches for deriving human stem cells circumnavigate existing patents that dominate embryonic stem cell intellectual property?

Estimating Energy Expenditure for Brief Bouts of Exercise with Acute Recovery

Applied Physiology, Nutrition, and Metabolism = Physiologie Appliquée, Nutrition Et Métabolisme. Apr, 2006  |  Pubmed ID: 16604132

Four indirect estimations of energy expenditure were examined, (i) O(2) debt, (ii) O(2) deficit, (iii) blood lactate concentration, and (iv) excess CO(2) production during and after 6 exercise durations (2, 4, 10, 15, 30, and 75 s) performed at 3 different intensities (50%, 100%, and 200% of VO(2) max). Analysis of variance (ANOVA) was used to determine if significant differences existed among these 4 estimations of anaerobic energy expenditure and among 4 estimations of total energy expenditure (that included exercise O(2) uptake and excess post-exercise oxygen consumption, or EPOC, measurements). The data indicate that estimations of anaerobic energy expenditure often differed for brief (2, 4, and 10 s) bouts of exercise, but this did not extend to total energy expenditure. At the higher exercise intensities with the longest durations O(2) deficit, blood lactate concentration, and excess CO(2) estimates of anaerobic and total energy expenditure revealed high variability; however, they were not statistically different. Moreover, they all differed significantly from the O(2) debt interpretation (p < 0.05). It is concluded that as the contribution of rapid substrate-level ATP turnover with lactate production becomes larger, the greatest error in quantifying total energy expenditure is suggested to occur not with the method of estimation, but with the omission of a reasonable estimate of anaerobic energy expenditure.

Chimeras in the Crosshairs

Nature Biotechnology. May, 2006  |  Pubmed ID: 16680119

Contribution of Blood Lactate to the Energy Expenditure of Weight Training

Journal of Strength and Conditioning Research / National Strength & Conditioning Association. May, 2006  |  Pubmed ID: 16686572

Bioenergetic interpretations of energy transfer specify that rapid anaerobic, substrate-level adenosine triphosphate (ATP) turnover with lactate production is not appropriately represented by an oxygen uptake measurement. Two types of weight training, 60% of 1 repetition maximum (1RM) with repetitions to exhaustion and 80% of 1RM with limited repetitions, were compared to determine if blood lactate measurements, as an estimate of rapid substrate-level ATP turnover, provide a significant contribution to the interpretation of total energy expenditure as compared with oxygen uptake methods alone. The measurement of total energy expenditure consisted of blood lactate, exercise oxygen uptake, and a modified excess postexercise oxygen consumption (EPOC); oxygen uptake-only measurements consisted of exercise oxygen uptake and EPOC. When data from male and female subjects were pooled, total energy expenditure was significantly higher for reps to exhaustion (arm curl, +27 kJ; bench press, +27 kJ; leg press, +38 kJ; p < 0.03) and limited reps (arm curl, +12 kJ; bench press, +23 kJ; leg press, + 24 kJ; p < 0.05) when a separate measure of blood lactate was part of the interpretation. When the data from men and women were analyzed separately, blood lactate often made a significant contribution to total energy expenditure for reps to exhaustion (endurance-type training), but this trend was not always statistically evident for the limited reps (strength-type training) protocol. It is suggested that the estimation of total energy expenditure for weight training is improved with the inclusion, rather than the omission, of an estimate of rapid anaerobic substrate-level ATP turnover.

A Comparison of Serum Creatinine-based Methods for Identifying Chronic Kidney Disease in Hypertensive Individuals and Their Siblings

American Journal of Hypertension. Jun, 2006  |  Pubmed ID: 16733233

The Modification of Diet in Renal Disease (MDRD) equation is often used to determine an estimated glomerular filtration rate (eGFR) from serum creatinine. This study compared kidney disease as defined by reduced eGFR, elevated serum creatinine, or elevated urinary albumin-to-creatinine ratio (ACR).

Dipeptide Proline Diphenyl Phosphonates Are Potent, Irreversible Inhibitors of Seprase (FAPalpha)

Biochemical and Biophysical Research Communications. Jul, 2006  |  Pubmed ID: 16769036

Dipeptidyl peptidase IV (DPP-IV) and seprase belong to a small group of membrane-bound, proline-specific serine proteases, the serine integral membrane proteases (SIMPs). Whilst DPP-IV is the most exhaustively studied peptidase in this class, relatively less is known about the inhibitor/substrate specificity of its close homolog seprase. Additionally, whereas, DPP-IV expression is largely ubiquitous, seprase expression is restricted to tumour and tissue remodelling sites in vivo. Consequently, the highly restricted expression and distribution of seprase potentially make it an excellent therapeutic target for the modulation of neoplastic invasion and metastasis. Against this background, we now wish to report on the design, synthesis, and kinetic testing of a series of dipeptide proline diphenyl phosphonates, against DPP-IV and seprase. The most potent inhibitor of DPP-IV and seprase was found to be Gly-ProP(OPh)2, which exhibited overall second-order rate constants of inactivation of 5.24 x 105 M-1 min-1 and 1.06 x 104 M-1 min-1 against DPP-IV and seprase, respectively. Both proteases displayed differing profiles of susceptibility towards the other members of the series of inhibitors synthesised. In addition, Gly-ProP(OPh)2 and Tyr-ProP(OPh)2 were found to exert a considerable, dose-dependent anti-invasive effect on the LOX melanoma cell line, in vitro.

Cardiopulmonary Exercise Testing Determination of Functional Capacity in Mitral Regurgitation: Physiologic and Outcome Implications

Journal of the American College of Cardiology. Jun, 2006  |  Pubmed ID: 16781383

This study was designed to evaluate prevalence, determinants, and clinical outcome implications of reduced functional capacity (FC) in patients with organic mitral regurgitation (MR).

Steroidogenic Alterations and Adrenal Androgen Excess in PCOS

Steroids. Sep, 2006  |  Pubmed ID: 16781743

This cross-sectional study was undertaken to improve our understanding of the steroidogenic alterations leading to adrenal hyperandrogenism in polycystic ovarian syndrome (PCOS).

Surgical Correction of Mitral Regurgitation in the Elderly: Outcomes and Recent Improvements

Circulation. Jul, 2006  |  Pubmed ID: 16847151

In the elderly, mitral regurgitation (MR) is frequent, but surgery risks are considered high. Benefits and indications of MR surgery are uncertain in the elderly.

Frequency and Determinants of Early Rapid Filling Abnormality

Journal of Nuclear Cardiology : Official Publication of the American Society of Nuclear Cardiology. Jul, 2006  |  Pubmed ID: 16919577

The frequency and determinants of early rapid diastolic filling abnormalities in the community and in cardiac patients are poorly understood.

Burden of Valvular Heart Diseases: a Population-based Study

Lancet. Sep, 2006  |  Pubmed ID: 16980116

Valvular heart diseases are not usually regarded as a major public-health problem. Our aim was to assess their prevalence and effect on overall survival in the general population.

The Role of Noradrenaline in the Generation of the Preovulatory LH Surge in the Ewe

Domestic Animal Endocrinology. May, 2006  |  Pubmed ID: 16139986

Increasing plasma estrogen (E) levels during the follicular phase of the estrous cycle trigger the pre-ovulatory surge of gonadotropin-releasing hormone (GnRH)/LH. Noradrenaline (NA)-producing cells of the brain stem are involved in regulating GnRH cells and project to the preoptic area (POA) and bed nucleus of stria terminalis (BnST). Input to GnRH cells may be direct or indirect, via relay neurons in the POA/BnST. To investigate this, we ascertained whether an alpha(1)-adrenergic antagonist would block/delay the LH surge in ovariectomised (OVX), E-treated ewes. E benzoate (EB) (50microg) was injected (i.m.) and Doxazosin (100nmol/h) or vehicle was infused into the third ventricle 2-26h after EB injection. Doxazosin reduced the magnitude of the LH surge, but did not affect timing. To determine if NA is released in the POA/BnST of cyclic ewes, we immunostained dopamine-beta-hydroxylase (DBH) in terminal fields. Reduced numbers of varicosities staining for DBH indicates release of NA. The number of varicosities immunostained for DBH was reduced in the dorsal and lateral BnST during the follicular phase and during the preovulatory LH surge compared to the luteal phase. These data suggest that noradrenergic mechanisms are involved in generation of the GnRH/LH surge via projections to the BnST and relay to GnRH cells. Since Doxasozin reduced the magnitude of the LH surge in the E-treated OVX ewe, and release of NA in cyclic ewes occurred during the follicular phase of the estrous cycle, we speculate that NA is a permissive factor in surge generation. Thus, increased noradrenergic activity is not a trigger mechanism for initiation of the surge.

CD33 Responses Are Blocked by SOCS3 Through Accelerated Proteasomal-mediated Turnover

Blood. Feb, 2007  |  Pubmed ID: 17008544

CD33 is a member of the sialic acid-binding immunoglobulin-like lectin (Siglec) family of inhibitory receptors and a therapeutic target for acute myeloid leukemia (AML). CD33 contains a cytoplasmic immunoreceptor tyrosine-based inhibitory motif (ITIM), which can recruit SHP-1 and SHP-2. How CD33 expression is regulated is unclear. Suppressor of cytokine signaling 3 (SOCS3) is expressed in response to cytokines, LPS, and other PAMPs, and competes with SHP-1/2 binding to ITIMs of cytokine receptors, thereby inhibiting signaling. In this study, using peptide pull-down experiments, we found that SOCS3 can specifically bind to the phosphorylated ITIM of CD33. Additionally, following cross-linking SOCS3 can recruit the ECS E3 ligase resulting in accelerated proteasomal degradation of both CD33 and SOCS3. Our data suggest that the tyrosine motifs in CD33 are not important for internalization, while they are required for degradation. Moreover, SOCS3 inhibited the CD33-induced block on cytokine-induced proliferation. This is the first receptor shown to be degraded by SOCS3 and where SOCS3 and its target protein are degraded concomitantly. Our findings clearly suggest that during an inflammatory response, the inhibitory receptor CD33 is lost by this mechanism. Moreover, this has important clinical implications as tumors expressing SOCS3 may be refractory to alpha-CD33 therapy.

What is Your Diagnosis? Cutaneous Larva Migrans

Cutis; Cutaneous Medicine for the Practitioner. Jun, 2007  |  Pubmed ID: 17713144

A Systematic Review of Population-based Studies of Infective Endocarditis

Chest. Sep, 2007  |  Pubmed ID: 17873196

We sought to summarize and critically appraise the literature on the epidemiology of infective endocarditis (IE) in the general population.

Mice with a Human Touch

Nature Biotechnology. Oct, 2007  |  Pubmed ID: 17921981

Onset of the Thermic Effect of Feeding (TEF): a Randomized Cross-over Trial

Journal of the International Society of Sports Nutrition. 2007  |  Pubmed ID: 18053263

ABSTRACT:

Aortic Valve Calcification: Determinants and Progression in the Population

Arteriosclerosis, Thrombosis, and Vascular Biology. Mar, 2007  |  Pubmed ID: 17185617

Aortic valve calcification (AVC) is considered degenerative. Recent data suggested links to atherosclerosis or coronary disease (CAD).

Mammographic Breast Density As a General Marker of Breast Cancer Risk

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. Jan, 2007  |  Pubmed ID: 17220330

Mammographic breast density is a strong risk factor for breast cancer but whether breast density is a general marker of susceptibility or is specific to the location of the eventual cancer is unknown. A study of 372 incident breast cancer cases and 713 matched controls was conducted within the Mayo Clinic mammography screening practice. Mammograms on average 7 years before breast cancer were digitized, and quantitative measures of percentage density and dense area from each side and view were estimated. A regional density estimate accounting for overall percentage density was calculated from both mammogram views. Location of breast cancer and potential confounders were abstracted from medical records. Conditional logistic regression was used to estimate associations, and C-statistics were used to evaluate the strength of risk prediction. There were increasing trends in breast cancer risk with increasing quartiles of percentage density and dense area, irrespective of the side of the breast with cancer (P(trends) < 0.001). Percentage density from the ipsilateral side [craniocaudal (CC): odds ratios (ORs), 1.0 (ref), 1.7, 3.1, and 3.1; mediolateral oblique (MLO): ORs, 1.0 (ref), 1.5, 2.2, and 2.8] and the contralateral side [CC: ORs, 1.0 (ref), 1.8, 2.2, and 3.7; MLO: ORs, 1.0 (ref), 1.6, 1.9, and 2.5] similarly predicted case-control status (C-statistics, 0.64-65). Accounting for overall percentage density, density in the region where the cancer subsequently developed was not a significant risk factor [CC: 1.0 (ref), 1.3, 1.0, and 1.2; MLO: 1.0 (ref), 1.1, 1.0, and 1.1 for increasing quartiles]. Results did not change when examining mammograms 3 years on average before the cancer. Overall mammographic density seems to represent a general marker of breast cancer risk that is not specific to breast side or location of the eventual cancer.

Overhauling Clinical Trials

Nature Biotechnology. Mar, 2007  |  Pubmed ID: 17344876

Longitudinal Trends in Mammographic Percent Density and Breast Cancer Risk

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. May, 2007  |  Pubmed ID: 17507617

Mammographic density is a strong risk factor for breast cancer. However, whether changes in mammographic density are associated with risk remains unclear.

Inhibition of Cathepsin L-like Proteases by Cathepsin V Propeptide

Biological Chemistry. May, 2007  |  Pubmed ID: 17516850

The N-terminal propeptide domains of several cathepsin L-like cysteine proteases have been shown to possess potent inhibitory activity. Here we report the first kinetic characterisation of the inhibition properties of the cathepsin V propeptide (CatV PP). Using a facile recombinant approach we demonstrate expression, purification and evaluation of the CatV PP. This propeptide was found to behave as a tight-binding inhibitor against CatV (K (i) 10.2 nm). It also functions as an inhibitor against other members of the CatL-like subclass (CatL, 9.8 nm; CatS, 10.7 nm; and CatK, 149 nm) and had no discernible effects upon the more distantly related CatB.

Left Atrial Remodelling in Mitral Regurgitation--methodologic Approach, Physiological Determinants, and Outcome Implications: a Prospective Quantitative Doppler-echocardiographic and Electron Beam-computed Tomographic Study

European Heart Journal. Jul, 2007  |  Pubmed ID: 17562673

To define accurate and normal range of echocardiographic left atrial (LA) volume measurement and to assess the prevalence, determinants, and outcome implications of LA enlargement in mitral regurgitation (MR).

Surveillance of Vision and Ocular Disorders in Children with Down Syndrome

Developmental Medicine and Child Neurology. Jul, 2007  |  Pubmed ID: 17593123

Children with Down syndrome have a high prevalence of ocular disorders. The UK Down's Syndrome Medical Interest Group (DSMIG) guidelines for ophthalmic screening were locally implemented into a protocol that included neonatal eye examination by an ophthalmologist and a comprehensive ophthalmological examination (cycloplegic refraction, ophthalmoscopy, and orthoptic assessment) by at least the age of 3 years, followed by preschool follow-up as indicated. We audited retrospectively surveillance for ocular disorders before and after the DSMIG-based guidelines were locally adopted in 1995. Results were compared for children born before and after the implementation of screening guidelines. A total of 81 children (43 females, 38 males) with Down syndrome were identified. After the DSMIG protocol, 34/36 children received a full ophthalmological examination in the neonatal period, compared with 9/27 children before 1995 (p<0.001). Neonatal screening resulted in the detection of cataracts in three infants. Mean age of first comprehensive ophthalmic screening outside the neonatal period was similar in the two groups (1y 6mo before guidelines vs 1y 9mo after), as were the proportion of children receiving preschool eye checks (27/30 before; 17/18 after). Overall, 65.7% children were screened in accordance with the guidelines, improving to 100% in recent years. At school age, 43% of the study population had significant refractive errors, with 27% having hypermetropia and astigmatism. Earlier prescription of glasses for refractive errors was seen (mean age 5y 6mo before guidelines; 3y 6mo after; p<0.001). Prevalence of other ocular disorders included strabismus (34/72, 47%), nasolacrimal duct obstruction (26/73, 35.6%), cataracts (5/64, 7.8%), and nystagmus (12/72, 16%). Establishment of the DSMIG-based local protocol has streamlined ocular surveillance. It is anticipated that this will improve developmental and functional outcomes in Down syndrome.

The Renaissance of Fixed Dose Combinations: Combivir

Therapeutics and Clinical Risk Management. Aug, 2007  |  Pubmed ID: 18472979

Combivir is a fixed dose combination tablet of two antiretroviral drugs; zidovudine and lamivudine, used in the treatment of HIV-1 infection. AZT was the first antiretroviral used in clinical trials and the addition of lamivudine improved its effectiveness. With the introduction of highly active antiretroviral therapy in the form of a combination of three drugs including two nucleoside analogues, Combivir became the gold standard nucleoside 'backbone' until very recently. Combivir was the first combination agent and simplified HIV therapy greatly. The introduction of newer fixed dose combinations with the advantage of once daily dosing and improved tolerability and toxicity profiles has made Combivir a less popular choice in treatment naïve individuals needing to start therapy.

Immunocolloidal Targeting of the Endocytotic Siglec-7 Receptor Using Peripheral Attachment of Siglec-7 Antibodies to Poly(lactide-co-glycolide) Nanoparticles

Pharmaceutical Research. Jan, 2008  |  Pubmed ID: 17674157

To prepare a nanoparticulate formulation expressing variable peripheral carboxyl density using non-endcapped and endcapped poly(lactide-co-glycolide), conjugated to antibodies recognising the siglec-7 receptor, which is expressed on most acute myeloid leukaemias. The aim is to exploit this receptor as a therapeutic target by constructing an internalising drug-loaded nanoparticle able to translocate into cytoplasm by siglec receptor-mediated internalisation.

A Cruel Twist: Post-operative Cecal Volvulus

Ulusal Travma Ve Acil Cerrahi Dergisi = Turkish Journal of Trauma & Emergency Surgery : TJTES. Apr, 2008  |  Pubmed ID: 18523909

Cecal volvulus is an uncommon cause of intestinal obstruction, accounting for less than 1% of cases in Western countries. In the literature, it has been described as a complication following numerous common surgeries as well as a number of minimally invasive procedures. Presumably, it is more likely to occur following any surgical procedure which might require some degree of medial visceral rotation or disruption of the fusion plane between the cecum or ascending colon with the lateral peritoneum, providing sufficient mobility to allow for cecal volvulization to occur. In addition, cadaver and autopsy studies have also suggested that 10-20% of the population may have sufficient mobility of the colon to allow for volvulization. We present a review of the literature pertaining to the diagnosis and management of cecal volvulus as well as the case of J.R., a 78-year-old male with cecal volvulus six days following a right radical nephrectomy for renal cell carcinoma.

Acne Vulgaris and Acne Rosacea As Part of Immune Reconstitution Disease in HIV-1 Infected Patients Starting Antiretroviral Therapy

International Journal of STD & AIDS. Jul, 2008  |  Pubmed ID: 18574128

Immune reconstitution disease (IRD) has been widely reported following the commencement of antiretrovirals. We report a case series from a cohort of HIV-1-infected patients of whom four developed acne vulgaris and one developed acne rosacea after the initiation of antiretroviral therapy. Acne vulgaris, as part of IRD, has been reported only once in the literature, whereas acne rosacea has not, to our knowledge, previously been described. This serves as a reminder not to overlook dermatological manifestations of disease in patients with HIV infection after starting antiretrovirals.

Antibody Targeting of Camptothecin-loaded PLGA Nanoparticles to Tumor Cells

Bioconjugate Chemistry. Aug, 2008  |  Pubmed ID: 18627195

Antibody targeting of drug substances can improve the efficacy of the active molecule, improving distribution and concentration of the drug at the site of injury/disease. Encapsulation of drug substances into polymeric nanoparticles can also improve the therapeutic effects of such compounds by protecting the molecule until its action is required. In this current study, we have brought together these two rationales to develop a novel immuno-nanoparticle with improved therapeutic effect against colorectal tumor cells. This nanoparticle comprised a layer of peripheral antibodies (Ab) directed toward the Fas receptor (CD95/Apo-1) covalently attached to poly(lactide-co-glycolide) nanoparticles (NP) loaded with camptothecin. Variations in surface carboxyl density permitted up to 48.5 microg coupled Ab per mg of NP and analysis of nanoparticulate cores showed efficient camptothecin loading. Fluorescence visualization studies confirmed internalization of nanoconstructs into endocytic compartments of HCT116 cells, an effect not evident in NP without superficial Ab. Cytotoxicity studies were then carried out against HCT116 cells. After 72 h, camptothecin solution resulted in an IC 50 of 21.8 ng mL (-1). Ab-directed delivery of NP-encapsulated camptothecin was shown to be considerably more effective with an IC 50 of 0.37 ng mL (-1). Calculation of synergistic ratios for these nanoconstructs demonstrated synergy of pharmacological relevance. Indeed, the results in this paper suggest that the attachment of anti-Fas antibodies to camptothecin-loaded nanoparticles may result in a therapeutic strategy that could have potential in the treatment of tumors expressing death receptors.

The Road to Pluripotence: the Research Response to the Embryonic Stem Cell Debate

Human Molecular Genetics. Apr, 2008  |  Pubmed ID: 18632694

The controversies surrounding embryonic stem cell research have prompted scientists to invent beyond restrictive national policy and moral concerns. The impetus behind these reports comes from different sources, including individually held moral beliefs, societal pressures and resource constraints, both biological and financial. Along with other contributions to public policy such as advocacy or public testimony, experimentation and scientific curiosity are perhaps more natural responses scientists use to surmount impediments to research. In a research context, we review the history of the first stem cell discoveries, and describe scientific efforts leading up to recent reports of pluripotent lines made without the use of human embryos and eggs. We argue that despite the promise of these new lines, we must not lose sight of fundamental questions remaining at the frontiers of embryology and early human development. The answers to these questions will impact studies of genetics, cell biology and diseases such as cancer, autoimmunity and disorders of development. Human embryonic stem cell research is barely a decade old. The recent pace of discovery--in spite of federal restrictions--is testament to the potential of these cells to uncover some of biology's most intractable mysteries.

A Novel FK506-like Binding Protein Interacts with the Glucocorticoid Receptor and Regulates Steroid Receptor Signaling

Endocrinology. Nov, 2008  |  Pubmed ID: 18669603

FKBP-like (FKBPL) protein is a novel immunophilin-like protein that plays a role in the cellular stress response. Its three tetratricopeptide repeat motifs are homologous to the heat shock protein 90 interaction sites of other immunophilins that have roles in steroid hormone receptor signaling. In this study, using biomolecular complementation and coimmunoprecipitation techniques, we show that FKBPL also colocalizes and interacts with the components of the heat shock protein 90-glucocorticoid receptor (GR) complex and demonstrate that the PPIase domain of FKBPL is important for the interaction between this complex and the dynein motor protein, dynamitin. Treatment of DU145 cells with the GR ligand, dexamethasone, induced a rapid and coordinated translocation of both GR and FKBPL to the nucleus; this response was perturbed when FKBPL was knocked down with a targeted small interfering RNA. Furthermore, overexpression of FKBPL increased GR protein levels and transactivation of a luciferase reporter gene in response to dexamethasone in DU145 cells. However, these responses were cell line dependent. In summary, these data suggest that FKBPL can be classed as a new member of the FKBP protein family with a role in steroid receptor complexes and signaling.

An Automated Approach for Estimation of Breast Density

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. Nov, 2008  |  Pubmed ID: 18990749

Breast density is a strong risk factor for breast cancer; however, no standard assessment method exists. An automated breast density method was modified and compared with a semi-automated, user-assisted thresholding method (Cumulus method) and the Breast Imaging Reporting and Data System four-category tissue composition measure for their ability to predict future breast cancer risk. The three estimation methods were evaluated in a matched breast cancer case-control (n = 372 and n = 713, respectively) study at the Mayo Clinic using digitized film mammograms. Mammograms from the craniocaudal view of the noncancerous breast were acquired on average 7 years before diagnosis. Two controls with no previous history of breast cancer from the screening practice were matched to each case on age, number of previous screening mammograms, final screening exam date, menopausal status at this date, interval between earliest and latest available mammograms, and residence. Both Pearson linear correlation (R) and Spearman rank correlation (r) coefficients were used for comparing the three methods as appropriate. Conditional logistic regression was used to estimate the risk for breast cancer (odds ratios and 95% confidence intervals) associated with the quartiles of percent breast density (automated breast density method, Cumulus method) or Breast Imaging Reporting and Data System categories. The area under the receiver operator characteristic curve was estimated and used to compare the discriminatory capabilities of each approach. The continuous measures (automated breast density method and Cumulus method) were highly correlated with each other (R = 0.70) but less with Breast Imaging Reporting and Data System (r = 0.49 for automated breast density method and r = 0.57 for Cumulus method). Risk estimates associated with the lowest to highest quartiles of automated breast density method were greater in magnitude [odds ratios: 1.0 (reference), 2.3, 3.0, 5.2; P trend < 0.001] than the corresponding quartiles for the Cumulus method [odds ratios: 1.0 (reference), 1.7, 2.1, and 3.8; P trend < 0.001] and Breast Imaging Reporting and Data System [odds ratios: 1.0 (reference), 1.6, 1.5, 2.6; P trend < 0.001] method. However, all methods similarly discriminated between case and control status; areas under the receiver operator characteristic curve were 0.64, 0.63, and 0.61 for automated breast density method, Cumulus method, and Breast Imaging Reporting and Data System, respectively. The automated breast density method is a viable option for quantitatively assessing breast density from digitized film mammograms.

Genetic Variation in Stromal Proteins Decorin and Lumican with Breast Cancer: Investigations in Two Case-control Studies

Breast Cancer Research : BCR. 2008  |  Pubmed ID: 19036156

The stroma is the supportive framework of biologic tissue in the breast, consisting of various proteins such as the proteoglycans, decorin and lumican. Altered expression of decorin and lumican is associated with breast tumors. We hypothesized that genetic variation in the decorin (DCN) and lumican (LUM) genes may contribute to breast cancer.

Exercise Oscillatory Ventilation: Instability of Breathing Control Associated with Advanced Heart Failure

Chest. Feb, 2008  |  Pubmed ID: 18071013

Instability of breathing control due to heart failure (HF) manifests as exercise oscillatory ventilation (EOV). Prior descriptions of patients with EOV have not been controlled and have been limited to subjects with left ventricular ejection fraction (LVEF) of

Role of Hepatic Resection for Patients with Carcinoid Heart Disease

Mayo Clinic Proceedings. Mayo Clinic. Feb, 2008  |  Pubmed ID: 18241623

To evaluate the effects of resection of hepatic carcinoid metastases on progression and prognosis of carcinoid heart disease.

The Benefits of Early Valve Replacement in Asymptomatic Patients with Severe Aortic Stenosis

The Journal of Thoracic and Cardiovascular Surgery. Feb, 2008  |  Pubmed ID: 18242258

The prevalence of aortic valve stenosis increases with age, and often the diagnosis is made by echocardiography before symptoms develop. To address the controversies in management of asymptomatic patients with severe aortic stenosis, we assessed the early and late outcomes of aortic valve replacement in these patients.

The Effect of Testosterone and Season on Prodynorphin Messenger RNA Expression in the Preoptic Area-hypothalamus of the Ram

Domestic Animal Endocrinology. May, 2008  |  Pubmed ID: 18308503

Testosterone and season influence mRNA expression for the opioid, enkephalin, in the preoptic area and hypothalamus of rams. Dynorphin is another opioid which has been shown to play a role in the control of reproductive function in females. We now report effects of season and testosterone on the expression of prodynorphin mRNA in the hypothalamus of the ram. Castrated adult Romney Marsh rams (5/group) received vehicle or testosterone propionate (i.m.) during either the 'breeding' season or 'non-breeding' season. Prodynorphin mRNA expression was quantified in the hypothalami by in situ hybridisation. Testosterone treatment increased prodynorphin mRNA expression in the supraoptic nucleus and the bed nucleus of the stria terminalis in the breeding season but not during the non-breeding season. Prodynorphin mRNA expression was also higher in the breeding season than in the non-breeding season in the caudal preoptic area, paraventricular nucleus and accessory supraoptic nucleus, irrespective of treatment. No effects of treatment were observed in any other regions of the hypothalamus. We conclude that testosterone and season regulate prodynorphin mRNA expression in a region-specific manner, which may influence seasonal changes in reproductive function.

Evaluation of a Dedicated Short-stay Unit for Acute Medical Admissions

Clinical Medicine (London, England). Feb, 2008  |  Pubmed ID: 18335661

The number of acute medical admissions to hospital continues to rise although not all need a prolonged stay. At the Queen Elizabeth Hospital, Gateshead, a short-stay unit (SSU) was developed specifically for such patients. Admissions to SSU over the first three weeks of 2006 were assessed. A total of 209 patients were admitted to SSU (10 patients a day). This accounted for 35% of all admissions through the medical assessment unit (MAU). Of these, 149 (71%) went home within 48 hours and a further 14 (7%) went home from SSU within 72 hours. The mean length of stay was 33 hours and the overall length of stay across the MAU (4.6 days) was significantly lower than the corresponding period a year earlier (5.5 days) (p = 0.02). The mean daily number of medical patients staying on non-medical wards was also lower during the study period than in 2005 (11 v 38; p = 0.015). Readmission rates and percentage bed occupancy did not change. This paper shows that the introduction of an SSU helps to identify and treat those patients with more minor illness who can often be discharged home at an earlier stage.

Stem Cells: New Frontiers of Ethics, Law, and Policy

Neurosurgical Focus. 2008  |  Pubmed ID: 18341401

After the successful isolation of human embryonic stem cells in 1998, ethics and policy debates centered on the moral status of the embryo-whether the 2- to 4-day-old blastocyst is a person, and whether we should protect it at all costs. As the research has moved quickly forward, however, new questions have emerged for the study of stem cell ethics, law, and policy. Powerful new lines made without eggs or embryos have recently been reported, the intellectual property and regulatory environment is uncertain, and clinical trials using adult stem cells and cells derived from embryonic stem cells are about to commence. The new landscape of ethics, law, and policy is discussed in the context of these developments, with an emphasis on the evaluation of risks and benefits for first-in-human clinical studies.

Activity-based Selection of a Proteolytic Species Using Ribosome Display

Biochemical and Biophysical Research Communications. May, 2008  |  Pubmed ID: 18343221

We have examined the potential of displaying a protease species in vitro using ribosome display and demonstrate specific capture on the basis of its catalytic activity. Using a model bacterial cysteine protease, sortase A (SrtA), we show that this enzyme can be functionally expressed in vitro. By overlap PCR we constructed ribosome display templates with the SrtA open reading frame fused to a C terminal glycine-serine rich flexible linker and a tether derived from eGFP. Using the broad range cysteine protease irreversible inhibitor E-64 linked to acrylic beads, we show that we can isolate SrtA ribosome display ternary complexes, and recover their encoding mRNA by RT-PCR. This recovery was lost when applied to a SrtA catalytically inactive mutant, or could be alleviated by competition with free inhibitor. This sensitive technique could be further developed to allow the screening of proteases against putative inhibitors and/or the identification of novel proteolytic species.

Recombinant Cathepsin S Propeptide Attenuates Cell Invasion by Inhibition of Cathepsin L-like Proteases in Tumor Microenvironment

Molecular Cancer Therapeutics. Mar, 2008  |  Pubmed ID: 18347141

Human cathepsin L along with cathepsin S, K, and V are collectively known as cathepsin L-like proteases due to their high homology. The overexpression and aberrant activity of each of these proteases has been implicated in tumorigenesis. These proteases contain propeptide domains that can potently inhibit both their cognate protease and other proteases within the cathepsin L-like subfamily. In this investigation, we have produced the cathepsin S propeptide recombinantly and have shown that it is a potent inhibitor of the peptidolytic, elastinolytic, and gelatinolytic activities of the cathepsin L-like proteases. In addition, we show that this peptide is capable of significantly attenuating tumor cell invasion in a panel of human cancer cell lines. Furthermore, fusion of an IgG Fc-domain to the COOH terminus of the propeptide resulted in a chimeric protein with significantly enhanced ability to block tumor cell invasion. This Fc fusion protein exhibited enhanced stability in cell-based assays in comparison with the unmodified propeptide species. This approach for the combined inhibition of the cathepsin L-like proteases may prove useful for the further study in cancer and other conditions where their aberrant activity has been implicated. Furthermore, this strategy for simultaneous inhibition of multiple cysteine cathepsins may represent the basis for novel therapeutics to attenuate tumorigenesis.

Challenges to Human Embryonic Stem Cell Patents

Cell Stem Cell. Jan, 2008  |  Pubmed ID: 18371416

The patenting of human embryonic stem (hES) cells has produced one of the most unusual and fraught situations in the history of science, ethics, and law. This Commentary examines legal and moral challenges to three foundational patents held by the Wisconsin Alumni Research Foundation (WARF). We conclude that, in the United States, technical challenges may, paradoxically, produce a stronger patent position for WARF. In the European Union, moral challenges mean confusion for member states. We demonstrate that hES cell intellectual property will be guided and bound by a welter of moral, technical, and legal inputs, with discrete national and jurisdictional dimensions.

Patenting Pluripotence: the Next Battle for Stem Cell Intellectual Property

Nature Biotechnology. Apr, 2008  |  Pubmed ID: 18392018

What will be the impact of induced pluripotent stem cell discoveries on the current stem cell patent landscape?

Association of Mammographic Density with the Pathology of Subsequent Breast Cancer Among Postmenopausal Women

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. Apr, 2008  |  Pubmed ID: 18398028

Limited studies have examined the associations between mammographic density and subsequent breast tumor characteristics.

Timing of Stroke After Cardiopulmonary Bypass Determines Mortality

The Annals of Thoracic Surgery. May, 2008  |  Pubmed ID: 18442537

Stroke is an important complication of cardiopulmonary bypass (CPB). This study determined if the timing of stroke events after CPB predicted stroke-related mortality or rehabilitation needs at hospital discharge.

Stem Cell Transplants: the Power of Peer-to-peer

Nature Biotechnology. Jan, 2009  |  Pubmed ID: 19131988

USP17 Regulates Ras Activation and Cell Proliferation by Blocking RCE1 Activity

The Journal of Biological Chemistry. Apr, 2009  |  Pubmed ID: 19188362

The proto-oncogene Ras undergoes a series of post-translational modifications at its carboxyl-terminal CAAX motif that are essential for its proper membrane localization and function. One step in this process is the cleavage of the CAAX motif by the enzyme Ras-converting enzyme 1 (RCE1). Here we show that the deubiquitinating enzyme USP17 negatively regulates the activity of RCE1. We demonstrate that USP17 expression blocks Ras membrane localization and activation, thereby inhibiting phosphorylation of the downstream kinases MEK and ERK. Furthermore, we show that this effect is caused by the loss of RCE1 catalytic activity as a result of its deubiquitination by USP17. We also show that USP17 and RCE1 co-localize at the endoplasmic reticulum and that USP17 cannot block proliferation or Ras membrane localization in RCE1 null cells. These studies demonstrate that USP17 modulates Ras processing and activation, at least in part, by regulating RCE1 activity.

Energy Expenditure Before, During, and After the Bench Press

Journal of Strength and Conditioning Research / National Strength & Conditioning Association. Mar, 2009  |  Pubmed ID: 19197214

We examined the reliability and validity of non-steady-state aerobic and anaerobic estimations of energy expenditure during and after bouts of the bench press exercise. A Smith machine, not free weights, was used. On different days, 8 subjects (28.4 +/- 9.0 years; 170.4 +/- 11.9 cm; 68.4 +/- 14.0 kg) were randomly assigned to 3 lifting sessions of 7, 14, and 21 reps at 50% of the 1-repetition maximum (9 total sessions). No differences were found in any of the triplicate measures within 7, 14, and 21 reps. Coefficients of variation for 7, 14, and 21 reps were, respectively, for resting blood lactate, 20.3, 24.3, and 26.7%; for anaerobic exercise energy expenditure, 47.9, 29.1, and 14.2%; for aerobic exercise energy expenditure, 47.4, 28.3, and 18.4%; for excess postexercise O2 consumption, 33.0, 26.5, and 29.2%; for total energy expenditure, 21.0, 15.4, and 15.1%; and, for work, 4.5, 5.0, and 5.4%. Anaerobic energy expenditure made a significant contribution to exercise energy expenditure for all lifts (p < 0.05). Changes (Delta) in work were related to changes in energy expenditure (Delta aerobic exercise energy expenditure, r = 0.54; Delta anaerobic exercise energy expenditure, r = 0.88; Delta total energy expenditure, r = 0.88; p < 0.001). Although variability is evident and often considerable during exercise and recovery in this heterogonous sample, we suggest that non-steady-state estimates of aerobic and anaerobic exercise energy expenditure with excess postexercise O2 consumption provide a reasonable estimate of the energy cost of a single bout of weight lifting. Our results agree with those of others, without the need for multiple steady-state measurements or for the assumption of proportional increases between work and O2 uptake.

Distribution of Human Embryonic Stem Cell Lines: Who, When, and Where

Cell Stem Cell. Feb, 2009  |  Pubmed ID: 19200799

Evidence of Systemic Th2-driven Chronic Inflammation in Patients with Metastatic Melanoma

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Mar, 2009  |  Pubmed ID: 19240164

Immunotherapeutic modalities are commonly used for treatment of patients with melanoma. The therapeutic success in preclinical models has not yielded the expected clinical results. To understand this discrepancy, we attempted to define immune homeostasis of 209 patients with melanoma across stages of disease relative to normal controls.

Texture Features from Mammographic Images and Risk of Breast Cancer

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. Mar, 2009  |  Pubmed ID: 19258482

Mammographic percent density (PD) is a strong risk factor for breast cancer, but there has been relatively little systematic evaluation of other features in mammographic images that might additionally predict breast cancer risk. We evaluated the association of a large number of image texture features with risk of breast cancer using a clinic-based case-control study of digitized film mammograms, all with screening mammograms before breast cancer diagnosis. The sample was split into training (123 cases and 258 controls) and validation (123 cases and 264 controls) data sets. Age-adjusted and body mass index (BMI)-adjusted odds ratios (OR) per SD change in the feature, 95% confidence intervals, and the area under the receiver operator characteristic curve (AUC) were obtained using logistic regression. A bootstrap approach was used to identify the strongest features in the training data set, and results for features that validated in the second half of the sample were reported using the full data set. The mean age at mammography was 64.0+/-10.2 years, and the mean time from mammography to breast cancer was 3.7+/-1.0 (range, 2.0-5.9 years). PD was associated with breast cancer risk (OR, 1.49; 95% confidence interval, 1.25-1.78). The strongest features that validated from each of several classes (Markovian, run length, Laws, wavelet, and Fourier) showed similar ORs as PD and predicted breast cancer at a similar magnitude (AUC=0.58-0.60) as PD (AUC=0.58). All of these features were automatically calculated (unlike PD) and measure texture at a coarse scale. These features were moderately correlated with PD (r=0.39-0.76), and after adjustment for PD, each of the features attenuated only slightly and retained statistical significance. However, simultaneous inclusion of these features in a model with PD did not significantly improve the ability to predict breast cancer.

The Stem-cell Century a New Epoch and Fresh Challenges

Perspectives in Biology and Medicine. 2009  |  Pubmed ID: 19271348

Stem-cell research is still a prominent part of the political, scientific, and public discourse. Scientific advances are being made at a rapid rate, while debates on the moral status of the embryo continue. In the United States, President George W. Bush has twice vetoed legislation that some maintain would be an improvement over the current funding environment; others argue the solution is not optimal for thoroughly exploiting the potential of this exciting new area of research. In addition, we face a number of additional policy and legal challenges, including such issues as intellectual property, oocyte procurement, and informed consent of egg donors. We review Russell Korobkin's Stem Cell Century in the context of recent additions to the literature on stem-cell research and policy.

Changes in Diastolic Dysfunction in Diabetes Mellitus over Time

The American Journal of Cardiology. May, 2009  |  Pubmed ID: 19427447

Several studies have demonstrated evidence for preclinical left ventricular (LV) diastolic dysfunction in patients with diabetes mellitus (DM) independent of coronary disease or hypertension. The objectives of our study were to determine if LV diastolic dysfunction determined by tissue Doppler indexes worsens with duration of DM and to quantify severity of dysfunction as a function of DM duration. From 1996 to 2007, all Olmsted County, Minnesota, residents with DM free of heart failure who had a subsequent measurement of diastolic function using tissue Doppler echocardiography were identified. We identified a validated group of 486 patients with incident DM with a subsequent tissue Doppler echocardiographic assessment of diastolic function. There was a significant association between the ratio of early mitral velocity (E) to medial mitral annulus velocity (e') and time from diabetes diagnosis to echocardiogram using simple linear regression; for every 1 year after the onset of diabetes, E/e' increased by 0.23 (95% confidence interval [CI] 0.16 to 0.30, p = 0.007) after adjustment for age, gender, body mass index, previous coronary disease, previous hypertension, and ejection fraction. A duration of diabetes >/=4 years was independently associated with LV diastolic dysfunction (E/e' >15) in multivariable logistic regression modeling after adjustment for age, gender, body mass index, previous coronary disease, previous hypertension, and ejection fraction (odds ratio 1.91, 95% CI 1.19 to 3.07, p = 0.007). There were 48 deaths in the validated cohort (6 cardiac deaths). In multivariable proportional hazard modeling, E/e' ratio was predictive of all-cause mortality after adjustment for age, gender, coronary disease, hypertension, ejection fraction, left atrial volume, and time from DM to echocardiogram (risk ratio 1.11, 95% CI 1.03 to 1.20, p = 0.005). In conclusion, duration of DM of > or =4 years is correlated with significant LV diastolic dysfunction. LV diastolic dysfunction is predictive of all-cause mortality in patients with DM independent of hypertension and coronary disease.

Gilead's Deal of a Lifetime

Nature Biotechnology. May, 2009  |  Pubmed ID: 19430443

Gilead Sciences' ascent to the upper echelon of biotech centered around one very savvy acquisition that launched an HIV franchise.

Ethics Report on Interspecies Somatic Cell Nuclear Transfer Research

Cell Stem Cell. Jul, 2009  |  Pubmed ID: 19570511

This report considers whether research involving the creation of human-animal interspecies somatic cell nuclear transfer (iSCNT) embryos raises new ethical issues, and if so, whether it requires additional or special criteria and oversight distinct from research on human-animal chimeras.

Relation of Dyspnea in Patients Unable to Perform Exercise Stress Testing to Outcome and Myocardial Ischemia

The American Journal of Cardiology. Jul, 2009  |  Pubmed ID: 19576358

Limited information exists regarding the significance of dyspnea in patients who are unable to exercise and the contribution of myocardial ischemia to this symptom. To assess this, we evaluated results of dobutamine stress echocardiography (DSE) and long-term outcome of patients with dyspnea referred for DSE. We studied 6,376 consecutive patients who were unable to perform an exercise test and were referred for DSE. Patients were classified according to presenting symptoms and followed for 5.5 +/- 2.8 years. End points were cardiac ischemic events (myocardial infarction or revascularization), hospitalization for heart failure (HF), and death. Dobutamine stress echocardiogram was positive for ischemia in 19% of patients with dyspnea versus 24% (p = 0.002) of those with typical angina and 17% (p = 0.2) of asymptomatic patients. In multivariate analysis, risk of death was increased in dyspneic patients versus asymptomatic patients (hazard ratio [HR] 1.14, p = 0.02) and patients with chest pain (HR 1.20, p <0.001). Hospitalization for HF occurred more often in patients with dyspnea (HR 1.26, p = 0.05 vs asymptomatic; HR 1.24, p = 0.06 vs chest pain), especially in the subset without previous HF (HR 1.45, p = 0.006 vs chest pain). Risk of cardiac ischemic events in patients with dyspnea was similar versus asymptomatic patients (HR 0.92, p = 0.39) and decreased versus patients with chest pain (HR 0.70, p <0.001). In conclusion, in patients referred for DSE, dyspnea was associated with a poor outcome. This increased hazard seems not to be linked to myocardial ischemia, but instead to HF and death.

And then There Were Two: Use of HESC Lines

Nature Biotechnology. Aug, 2009  |  Pubmed ID: 19668169

Safety of Contrast Agent Use During Stress Echocardiography: a 4-year Experience from a Single-center Cohort Study of 26,774 Patients

JACC. Cardiovascular Imaging. Sep, 2009  |  Pubmed ID: 19761981

We evaluated the short- and long-term safety of contrast agents during stress echocardiography (SE).

Antibody-mediated Inhibition of Cathepsin S Blocks Colorectal Tumor Invasion and Angiogenesis

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Oct, 2009  |  Pubmed ID: 19789302

Cathepsin S is a cysteine protease that promotes the invasion of tumor and endothelial cells during cancer progression. Here we investigated the potential to target cathepsin S using an antagonistic antibody, Fsn0503, to block these tumorigenic effects.

Expedited Solid-phase Synthesis of Fluorescently Labeled and Biotinylated Aminoalkane Diphenyl Phosphonate Affinity Probes for Chymotrypsin- and Elastase-like Serine Proteases

Bioconjugate Chemistry. Nov, 2009  |  Pubmed ID: 19810697

In this study, we report on a novel, expedited solid-phase approach for the synthesis of biotinylated and fluorescently tagged irreversible affinity based probes for the chymotrypsin and elastase-like serine proteases. The novel solid-phase biotinylation or fluorescent labeling of the aminoalkane diphenyl phosphonate warhead using commercially available Biotin-PEG-NovaTag or EDANS NovaTag resin permits rapid, facile synthesis of these reagents. We demonstrate the kinetic evaluation and utilization of a number of these irreversible inactivators for chymotrypsin-like (chymotrypsin/human cathepsin G) and elastase-like serine proteases. Encouragingly, these compounds display comparable potency against their target proteases as their N-benzyloxycarbonyl (Cbz)-protected parent compounds, from which they were derived, and function as efficient active site-directed inactivators of their target proteases. We subsequently applied the biotinylated reagents for the sensitive detection of protease species via Western blot, showing that the inactivation of the protease was specifically mediated through the active site serine. Furthermore, we also demonstrate the successful detection of serine protease species with the fluorescently labeled derivatives "in-gel", thus avoiding the need for downstream Western blotting. Finally, we also show the utility of biotinylated and pegylated affinity probes for the isolation/enrichment of serine protease species, via capture with immobilized streptavidin, and their subsequent identification via de novo sequencing. Given their selectivity of action against the serine proteases, we believe that these reagents can be exploited for the direct, rapid, and selective identification of these enzymes from biological milieu containing multiple protease subclasses.

IPS Cells: Mapping the Policy Issues

Cell. Dec, 2009  |  Pubmed ID: 20005794

Given the explosion of research on induced pluripotent stem (iPS) cells, it is timely to consider the various ethical, legal, and social issues engaged by this fast-moving field. Here, we review issues associated with the procurement, basic research, and clinical translation of iPS cells.

The Practical Consequences of a National Human Embryonic Stem Cell Registry

Stem Cell Reviews. Dec, 2009  |  Pubmed ID: 20058195

The executive order and issuance of federal guidelines for human embryonic stem cell research are positive developments and will produce long-term benefits by creating a new registry for hESC lines. But there may be short-term costs caused by regulatory uncertainty, procedural delay, and knock-on effects as national policies are adopted at state and local jurisdictions. Policymakers must ensure that national mechanisms of oversight for a new hESC registry are adequately funded, properly organized, transparent, and free of bureaucratic detail.

Expression and Purification of Diagnostically Sensitive Mycobacterial (Mycobacterium Bovis) Antigens and Profiling of Their Humoral Immune Response in a Rabbit Model

Research in Veterinary Science. Aug, 2010  |  Pubmed ID: 20096429

The incidence of bovine tuberculosis (bTB) is increasingly giving rise to large economic losses in the agricultural industry. The current methods used for detection and control of bTB (skin test and interferon-gamma) lack desired sensitivity and specificity. Therefore, the development of a rapid and reliable bTB serological based assay is urgently required. An antibody assay using combinations of strain-specific mycobacterial antigens could resolve both specificity and sensitivity issues. We analyzed the ability of a series of selected mycobacterial antigens to outline a humoral immune response in a rabbit model experimentally challenged with different mycobacterium. Antibodies specific for three antigens, MTB40, ESAT6 and CFP10, were present in serum 2 weeks post-challenge (early indicator), while two other antigens, Rv3870 and Rv1580c, could be detected from 8 to 11 weeks post-challenge. These selected mycobacterial antigens did not exhibit any cross-reactivity with avian PPD and only a very low positivity with bovine PPD. This data suggests that this panel of strain-specific mycobacterial antigens could be used for identification of Mycobacteriumbovis infection in serum samples. The combinatorial application of these antigens could form part of a serum field test which may assist the future diagnosis of TB.

Does Left Atrial Size Predict Mortality in Asymptomatic Patients with Severe Aortic Stenosis?

Echocardiography (Mount Kisco, N.Y.). Feb, 2010  |  Pubmed ID: 20113330

We assessed the hypothesis that diastolic function represented by left atrial size determines the rate of development of symptoms and the risk of all-cause mortality in asymptomatic patients with severe aortic stenosis (AS).

The Development of Heart Failure in Patients with Diabetes Mellitus and Pre-clinical Diastolic Dysfunction a Population-based Study

Journal of the American College of Cardiology. Jan, 2010  |  Pubmed ID: 20117433

The purpose of this study was to evaluate the outcomes of pre-clinical diastolic dysfunction in diabetic patients.

Never Again

Nature Biotechnology. Feb, 2010  |  Pubmed ID: 20139946

The Deubiquitinating Enzyme USP17 Blocks N-Ras Membrane Trafficking and Activation but Leaves K-Ras Unaffected

The Journal of Biological Chemistry. Apr, 2010  |  Pubmed ID: 20147298

The proto-oncogenic Ras isoforms (H, N, and K) have a C-terminal CAAX motif and undergo the same post-translational processing steps, although they traffic to the plasma membrane through different routes. Previously, we have shown that overexpression of the deubiquitinating enzyme USP17 inhibits H-Ras localization to the plasma membrane. Now we report that whereas H-Ras and N-Ras were unable to localize to the plasma membrane in the presence of USP17, K-Ras4b localization was unaffected. EGF stimulation was unable to induce N-Ras membrane localization in USP17-expressing cells. In addition, N-Ras activity and downstream signaling through the MAPK MEK/ERK and PI3K/JNK pathways were blunted. However, we still detected abundant N-Ras localization at the ER and Golgi in USP17-expressing cells. Collectively, our data showed that the deubiquitinating enzyme USP17 blocks EGF-induced N-Ras membrane trafficking and activation, but left K-Ras unaffected.

Characteristics and Outcomes of Patients with Abnormal Stress Echocardiograms and Angiographically Mild Coronary Artery Disease (<50% Stenoses) or Normal Coronary Arteries

Journal of the American Society of Echocardiography : Official Publication of the American Society of Echocardiography. Feb, 2010  |  Pubmed ID: 20152703

Abnormal cardiac stress imaging findings are not always associated with angiographically significant coronary artery disease. The outcomes of patients with such false-positive findings have not been extensively examined. The aim of this retrospective study was to describe the characteristics and outcomes of patients with abnormal stress echocardiographic findings who had false-positive results compared with those who had true-positive results.

Unselected Hepatitis C Screening of Men Who Have Sex with Men Attending Sexual Health Clinics

The Journal of Infection. May, 2010  |  Pubmed ID: 20153770

Sexual transmission of hepatitis C (HCV) between HIV positive men who have sex with men (MSM) is increasingly being reported. There is limited and conflicting data as to whether HIV negative MSM are at increased risk of infection. Local directorate guidelines recommended HCV testing only in MSM having a sexual transmitted infection (STI) screen who disclosed risk factors. In 2007 we introduced unselected screening into routine practice within our sexual health clinics. This report reviews the results of this change in our practice. Over 6 months, 3365 MSM attended for STI screening. Of 2309 MSM who agreed to be screened for HCV (69%) the prevalence of HCV was 0.65% (95% CI 0.36-1.1). This is similar to the prevalence of HCV in the general population within England. We conclude that unselected screening of MSM for HCV within our sexual health services is not currently justified.

Gene Delivery Using Dimethyldidodecylammonium Bromide-coated PLGA Nanoparticles

Biomaterials. May, 2010  |  Pubmed ID: 20185174

In this present work we describe a poly(lactic-co-glycolic acid) (PLGA) nanoparticle formulation for intracellular delivery of plasmid DNA. This formulation was developed to encapsulate DNA within PLGA nanoparticles that combined salting out and emulsion-evaporation processes. This process reduced the requirement for sonication which can induce degradation of the DNA. A monodispersed nanoparticle population with a mean diameter of approximately 240 nm was produced, entrapping a model plasmid DNA in both supercoiled and open circular structures. To induce endosomal escape of the nanoparticles, a superficial cationic charge was introduced using positively charged surfactants cetyl trimethylammonium bromide (CTAB) and dimethyldidodecylammonium bromide (DMAB), which resulted in elevated zeta potentials. As expected, both cationic coatings reduced cell viability, but at equivalent positive zeta potentials, the DMAB coated nanoparticles induced significantly less cytotoxicity than those coated with CTAB. Fluorescence and transmission electron microscopy demonstrated that the DMAB coated cationic nanoparticles were able to evade the endosomal lumen and localise in the cytosol of treated cells. Consequently, DMAB coated PLGA nanoparticles loaded with a GFP reporter plasmid exhibited significant improvements in transfection efficiencies with comparison to non-modified particles, highlighting their functional usefulness. These nanoparticles may be useful in delivery of gene therapies to targeted cells.

Genetic Variation in the Estrogen Metabolic Pathway and Mammographic Density As an Intermediate Phenotype of Breast Cancer

Breast Cancer Research : BCR. 2010  |  Pubmed ID: 20214802

Several studies have examined the effect of genetic variants in genes involved in the estrogen metabolic pathway on mammographic density, but the number of loci studied and the sample sizes evaluated have been small and pathways have not been evaluated comprehensively. In this study, we evaluate the association between mammographic density and genetic variants of the estrogen metabolic pathway.

Safety of Contrast Agent Use During Stress Echocardiography in Patients with Elevated Right Ventricular Systolic Pressure: a Cohort Study

Circulation. Cardiovascular Imaging. May, 2010  |  Pubmed ID: 20233859

Microbubble safety concerns led to changes in product recommendations for patients with pulmonary hypertension. Noninvasive estimation of right ventricular systolic pressure (RVSP) is equivalent to pulmonary artery systolic pressure in the absence of pulmonary outflow obstruction. We analyzed the short- and long-term outcomes of patients who received microbubble contrast and those who did not during stress echocardiography (SE) according to resting RVSP.

Advanced Heart Failure and Nocturnal Hypoxaemia Due to Central Sleep Apnoea Are Associated with Increased Serum Erythropoietin

European Journal of Heart Failure. Apr, 2010  |  Pubmed ID: 20335353

Central sleep apnoea (CSA) and increased serum erythropoietin (EPO) concentration have each been associated with adverse prognosis in heart failure (HF) patients. The aim of this study was to examine the relationship between nocturnal hypoxaemia due to CSA and the serum EPO concentration in patients with HF.

Biologic Protease Inhibitors As Novel Therapeutic Agents

Biochimie. Nov, 2010  |  Pubmed ID: 20346385

Deregulated proteolytic activities frequently have causative or exacerbative functions in pathological conditions such as cancer and inflammatory disease. Many proteases therefore represent therapeutic targets, but the generation of successful small molecule drugs is often limited by the ability to achieve sufficient specificity of action. Consequently, several proteases have been deemed as unsuitable drug targets due to the inability to target them successfully. In an effort to circumvent these issues, much interest has recently focused on the development and application of biologic inhibitors. In this review, the latest research in the development of biologic protease inhibitors is examined. This includes a review of engineered kunitz and other inhibitory domains as well as the application of antibodies as therapeutically viable inhibitors.

Association Between Mammographic Density and Age-related Lobular Involution of the Breast

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. May, 2010  |  Pubmed ID: 20351335

Mammographic density and lobular involution are both significant risk factors for breast cancer, but whether these reflect the same biology is unknown. We examined the involution and density association in a large benign breast disease (BBD) cohort.

The Deubiquitinating Enzyme USP17 is Highly Expressed in Tumor Biopsies, is Cell Cycle Regulated, and is Required for G1-S Progression

Cancer Research. Apr, 2010  |  Pubmed ID: 20388806

Ubiquitination is a reversible posttranslational modification that is essential for cell cycle control, and it is becoming increasingly clear that the removal of ubiquitin from proteins by deubiquitinating enzymes (DUB) is equally important. In this study, we have identified high levels of the DUB USP17 in several tumor-derived cell lines and primary lung, colon, esophagus, and cervix tumor biopsies. We also report that USP17 is tightly regulated during the cell cycle in all the cells examined, being abundantly evident in G(1) and absent in S phase. Moreover, regulated USP17 expression was necessary for cell cycle progression because its depletion significantly impaired G(1)-S transition and blocked cell proliferation. Previously, we have shown that USP17 regulates the intracellular translocation and activation of the GTPase Ras by controlling Ras-converting enzyme 1 (RCE1) activation. RCE1 also regulates the processing of other proteins with a CAAX motif, including Rho family GTPases. We now show that USP17 depletion blocks Ras and RhoA localization and activation. Moreover, our results confirm that USP17-depleted cells have constitutively elevated levels of the cyclin-dependent kinase inhibitors p21(cip1) and p27(kip1), known downstream targets of Ras and RhoA signaling. These observations clearly show that USP17 is tightly regulated during cell division and that its expression is necessary to coordinate cell cycle progression, and thus, it may be considered a promising novel cancer therapeutic target.

The DUB/USP17 Deubiquitinating Enzymes: a Gene Family Within a Tandemly Repeated Sequence, is Also Embedded Within the Copy Number Variable Beta-defensin Cluster

BMC Genomics. 2010  |  Pubmed ID: 20403174

The DUB/USP17 subfamily of deubiquitinating enzymes were originally identified as immediate early genes induced in response to cytokine stimulation in mice (DUB-1, DUB-1A, DUB-2, DUB-2A). Subsequently we have identified a number of human family members and shown that one of these (DUB-3) is also cytokine inducible. We originally showed that constitutive expression of DUB-3 can block cell proliferation and more recently we have demonstrated that this is due to its regulation of the ubiquitination and activity of the 'CAAX' box protease RCE1.

Independent Predictors of Survival in Primary Systemic (Al) Amyloidosis, Including Cardiac Biomarkers and Left Ventricular Strain Imaging: an Observational Cohort Study

Journal of the American Society of Echocardiography : Official Publication of the American Society of Echocardiography. Jun, 2010  |  Pubmed ID: 20434879

The prognostic value of Doppler myocardial imaging, including myocardial velocity imaging, strain, and strain rate imaging, in patients with primary (AL) amyloidosis is uncertain. The aim of this longitudinal study was to identify independent predictors of survival, comparing clinical data, hematologic and cardiac biomarkers, and standard echocardiographic and Doppler myocardial imaging measures in a cohort of patients with AL amyloidosis.

Hypoxia-inducible Factor-1alpha Regulates Beta Cell Function in Mouse and Human Islets

The Journal of Clinical Investigation. Jun, 2010  |  Pubmed ID: 20440072

Hypoxia-inducible factor-1alpha (HIF-1alpha) is a transcription factor that regulates cellular stress responses. While the levels of HIF-1alpha protein are tightly regulated, recent studies suggest that it can be active under normoxic conditions. We hypothesized that HIF-1alpha is required for normal beta cell function and reserve and that dysregulation may contribute to the pathogenesis of type 2 diabetes (T2D). Here we show that HIF-1alpha protein is present at low levels in mouse and human normoxic beta cells and islets. Decreased levels of HIF-1alpha impaired glucose-stimulated ATP generation and beta cell function. C57BL/6 mice with beta cell-specific Hif1a disruption (referred to herein as beta-Hif1a-null mice) exhibited glucose intolerance, beta cell dysfunction, and developed severe glucose intolerance on a high-fat diet. Increasing HIF-1alpha levels by inhibiting its degradation through iron chelation markedly improved insulin secretion and glucose tolerance in control mice fed a high-fat diet but not in beta-Hif1a-null mice. Increasing HIF-1alpha levels markedly increased expression of ARNT and other genes in human T2D islets and improved their function. Further analysis indicated that HIF-1alpha was bound to the Arnt promoter in a mouse beta cell line, suggesting direct regulation. Taken together, these findings suggest an important role for HIF-1alpha in beta cell reserve and regulation of ARNT expression and demonstrate that HIF-1alpha is a potential therapeutic target for the beta cell dysfunction of T2D.

Response to Open Peer Commentaries on "Stem Cell Tourism and the Power of Hope"

The American Journal of Bioethics : AJOB. May, 2010  |  Pubmed ID: 20461635

Stem Cell Tourism and the Power of Hope

The American Journal of Bioethics : AJOB. May, 2010  |  Pubmed ID: 20461637

This paper explores the notions of hope and how individual patient autonomy can trump carefully reasoned ethical concerns and policies intended to regulate stem cell transplants. We argue that the same limits of knowledge that inform arguments to restrain and regulate unproven treatments might also undermine our ability to comprehensively dismiss or condemn them. Incautiously or indiscriminately reasoned policies and attitudes may drive critical information and data underground, impel patients away from working with clinical researchers, and tread needlessly on hope, the essential motivator of patients, advocates and researchers alike. We offer recommendations to clinicians and health care providers to help balance the discourse with individuals seeking treatment while guarding against fraud, misconception, and patient harm.

Stem Cell Research Policy and IPS Cells

Nature Methods. Jan, 2010  |  Pubmed ID: 20038953

Pluripotent Patents Make Prime Time: an Analysis of the Emerging Landscape

Nature Biotechnology. Jun, 2010  |  Pubmed ID: 20531331

Federal Policy and the Use of Pluripotent Stem Cells

Nature Methods. Nov, 2010  |  Pubmed ID: 21030961

Tetralogy of Fallot Repair in Patients 40 Years or Older

Mayo Clinic Proceedings. Mayo Clinic. Dec, 2010  |  Pubmed ID: 21123635

To report the outcomes of patients with tetralogy of Fallot (TOF) undergoing surgical repair at age 40 years or older.

Inhibition of Secretion of Interleukin (IL)-12/IL-23 Family Cytokines by 4-trifluoromethyl-celecoxib is Coupled to Degradation Via the Endoplasmic Reticulum Stress Protein HERP

The Journal of Biological Chemistry. Mar, 2010  |  Pubmed ID: 20054003

Interleukin-12 (IL-12), p80, and IL-23 are structurally related cytokines sharing a p40 subunit. We have recently demonstrated that celecoxib and its COX-2-independent analogue 4-trifluoromethyl-celecoxib (TFM-C) inhibit secretion but not transcription of IL-12 (p35/p40) and p80 (p40/p40). This is associated with a mechanism involving altered cytokine-chaperone interaction in the endoplasmic reticulum (ER). In the present study, we found that celecoxib and TFM-C also block secretion of IL-23 (p40/p19 heterodimers). Given the putative ER-centric mode of these compounds, we performed a comprehensive RT-PCR analysis of 23 ER-resident chaperones/foldases and associated co-factors. This revealed that TFM-C induced 1.5-3-fold transcriptional up-regulation of calreticulin, GRP78, GRP94, GRP170, ERp72, ERp57, ERdj4, and ERp29. However, more significantly, a 7-fold up-regulation of homocysteine-inducible ER protein (HERP) was observed. HERP is part of a high molecular mass protein complex involved in ER-associated protein degradation (ERAD). Using co-immunoprecipitation assays, we show that TFM-C induces protein interaction of p80 and IL-23 with HERP. Both HERP siRNA knockdown and HERP overexpression coupled to cycloheximide chase assays revealed that HERP is necessary for degradation of intracellularly retained p80 by TFM-C. Thus, our data suggest that targeting cytokine folding in the ER by small molecule drugs could be therapeutically exploited to alleviate inappropriate inflammation in autoimmune conditions.

Regulation of Circulating Progenitor Cells in Left Ventricular Dysfunction

Circulation. Heart Failure. Sep, 2010  |  Pubmed ID: 20573992

Reductions in numbers of circulating progenitor cells (CD34+ cell subsets) have been demonstrated in patients at risk for, or in the presence of, cardiovascular disease. The mediators of these reductions remain undefined. To determine whether neurohumoral factors might regulate circulating CD34+ cell subsets in vivo, we studied complementary canine models of left ventricular (LV) dysfunction.

Gandhi and the 'struck-off' Doctor, Thomas Richard Allinson (1858-1918)

Journal of Medical Biography. Aug, 2010  |  Pubmed ID: 20798411

Gandhi visited London on several occasions. During two of these visits, when he was a law student from 1888 and again in 1914, he met Thomas Richard Allinson, a controversial doctor whose name was erased from the Medical Register in 1892. While in London studying for the bar, Gandhi was influenced in his search for a suitable vegetarian diet by the writings and personal support of Allinson. Although disagreeing profoundly with Allinson's views on birth control, he spoke up in defence of his right to hold them--probably the first time Gandhi challenged authority and an occasion which shows him as a tongue-tied young man but even then having a personal moral code that gives insight into the character of the future Mahatma. On Gandhi's further visit to England in 1914 Allinson, although no longer on the Medical Register, treated Gandhi for pleurisy, apparently partially successfully when orthodox medicine had failed.

Antibody Targeting of Cathepsin S Inhibits Angiogenesis and Synergistically Enhances Anti-VEGF

PloS One. 2010  |  Pubmed ID: 20824056

Angiogenesis is a key hallmark of tumourigenesis and its inhibition is a proven strategy for the development of novel anti-cancer therapeutics. An important aspect of early angiogenesis is the co-ordinated migration and invasion of endothelial cells through the hypoxic tumour tissue. Cathepsin S has been shown to play an important role in angiogenesis as has vascular endothelial growth factor (VEGF). We sought to assess the anti-angiogenic effect of Fsn0503, a novel cathepsin S inhibitory antibody, when combined with anti-VEGF on vascular development.

Acute Thrombus Formation As a Complication of Right Ventricular Biopsy

Journal of the American Society of Echocardiography : Official Publication of the American Society of Echocardiography. Oct, 2010  |  Pubmed ID: 20868954

While using echocardiography to guide endomyocardial biopsy (EMB), the authors have identified acute intracardiac thrombus formation related to the procedure, a hitherto unreported complication. The aims of this study were to identify the procedural details and characteristics of patients who developed this complication between June 2008 and April 2009 and to describe their outcomes and management.

Production of Recombinant Proteins in Escherichia Coli Using an N-terminal Tag Derived from Sortase

Protein Expression and Purification. Apr, 2010  |  Pubmed ID: 19883766

The use of Escherichia coli protein expression systems has many benefits, including the ease of propagation, amounts of protein that can be generated and cost. However, this host has some drawbacks due to difficulties in the production of soluble foreign proteins with their alternate codon usage bias, reductive cytoplasmic environment and lack of complex post-translational modifications. We have designed a novel fusion protein tag derived from the sequence of sortase (SrtA) which we have named Solubility 'eNhancing'Ubiquitous Tag (SNUT). Here we demonstrate its application and effectiveness as an N-terminal fusion tag for the expression and purification of proteins that could not be effectively produced with other tags. We show this tag can be utilized for the purification of proteins through both native and refolding immobilized metal ion chromatography and in combination with an anti-SNUT monoclonal antibody, can also be used as a detection tag. This tag may prove useful in circumventing expression and purification issues with the production of proteins in bacterial expression hosts.

Autofluorescence Imaging - a Useful Adjunct in Imaging Macular Trauma

Clinical Ophthalmology (Auckland, N.Z.). 2010  |  Pubmed ID: 21191446

Autofluorescence imaging is a rapid, noninvasive technique, with several applications becoming slowly integrated into ophthalmic clinical practice. We describe its use as a valuable tool for predicting the function of the retinal pigment epithelium following damage from blunt ocular trauma.

Diffusion Tensor Imaging Abnormalities in Cognitively Impaired Multiple Sclerosis Patients

The Canadian Journal of Neurological Sciences. Le Journal Canadien Des Sciences Neurologiques. Sep, 2010  |  Pubmed ID: 21059506

Cognitive impairment can add to the burden of disease in patients with multiple sclerosis (MS). The aim of this study was to assess the relative importance of diffusion tensor imaging (DTI) indices derived from normal appearing white matter (NAWM) and grey matter (NAGM) in determining cognitive dysfunction in MS patients.

Microneedle-mediated Intradermal Nanoparticle Delivery: Potential for Enhanced Local Administration of Hydrophobic Pre-formed Photosensitisers

Photodiagnosis and Photodynamic Therapy. Dec, 2010  |  Pubmed ID: 21112544

To date, 5-aminolevulinic acid (ALA) has been the most widely used agent in topical photodynamic therapy (PDT). However, owing to the poor penetration of ALA into skin, ALA-PDT is inappropriate for difficult-to-treat deep skin neoplasias, such as nodular basal cell carcinoma. An alternative strategy to ALA-PDT is to use pre-formed photosensitisers, which can be activated at longer wavelengths, facilitating enhanced light penetration into skin. Owing to their relatively high molecular weights and often high lipophilicities, these compounds cannot be effectively administered topically. This study aimed to deliver a model hydrophobic dye, Nile red, into the skin using novel microneedle (MN) technology.

Occurrence of Atrial Fibrillation During Dobutamine Stress Echocardiography: Incidence, Risk Factors, and Outcomes

Journal of the American Society of Echocardiography : Official Publication of the American Society of Echocardiography. Jan, 2011  |  Pubmed ID: 21172598

The reported incidence of atrial fibrillation (AF) occurring during dobutamine stress echocardiography (DSE) ranges from 0.5% to 4%. The aim of this study was to characterize the incidence, risk factors, and outcomes of AF precipitated during DSE.

Is the Standard Weight-based Dosing of Dobutamine for Stress Testing Appropriate for Patients of Widely Varying Body Mass Index?

Journal of Cardiovascular Pharmacology and Therapeutics. Jun, 2011  |  Pubmed ID: 21183730

Although a gradual increase in heart rate (HR) during dobutamine stress testing (DST) is desired, few data exists regarding whether this is similarly achieved in patients of widely varying body mass index (BMI). Whether difference in BMI contributes to variation in the hemodynamic and symptomatic response to dobutamine is also unknown.

Cysteine Cathepsins S and L Modulate Anti-angiogenic Activities of Human Endostatin

The Journal of Biological Chemistry. Oct, 2011  |  Pubmed ID: 21896479

Human endostatin, a potent anti-angiogenic protein, is generated by release of the C terminus of collagen XVIII. Here, we propose that cysteine cathepsins are involved in both the liberation and activation of bioactive endostatin fragments, thus regulating their anti-angiogenic properties. Cathepsins B, S, and L efficiently cleaved in vitro FRET peptides that encompass the hinge region corresponding to the N terminus of endostatin. However, in human umbilical vein endothelial cell-based assays, silencing of cathepsins S and L, but not cathepsin B, impaired the generation of the ∼22-kDa endostatin species. Moreover, cathepsins L and S released two peptides from endostatin with increased angiostatic properties and both encompassing the NGR sequence, a vasculature homing motif. The G10T peptide (residues 1455-1464: collagen XVIII numbering) displayed compelling anti-proliferative (EC(50) = 0.23 nm) and proapoptotic properties. G10T inhibited aminopeptidase N (APN/CD13) and reduced tube formation of endothelial cells in a manner similar to bestatin. Combination of G10T with bestatin resulted in no further increase in anti-angiogenic activity. Taken together, these data suggest that endostatin-derived peptides may represent novel molecular links between cathepsins and APN/CD13 in the regulation of angiogenesis.

Neuropsychiatric Symptoms During 24 Hours After Dobutamine-atropine Stress Testing: a Prospective Study in 1,006 Patients

Journal of the American Society of Echocardiography : Official Publication of the American Society of Echocardiography. Apr, 2011  |  Pubmed ID: 21227649

The aim of this study was to investigate the incidence and predictors of neuropsychiatric (NP) symptoms during 24 hours after dobutamine-atropine stress testing (DST).

Common Variants in ZNF365 Are Associated with Both Mammographic Density and Breast Cancer Risk

Nature Genetics. Mar, 2011  |  Pubmed ID: 21278746

High-percent mammographic density adjusted for age and body mass index is one of the strongest risk factors for breast cancer. We conducted a meta analysis of five genome-wide association studies of percent mammographic density and report an association with rs10995190 in ZNF365 (combined P = 9.6 × 10(-10)). Common variants in ZNF365 have also recently been associated with susceptibility to breast cancer.

Mothers, Fathers, Peers, and Mexican-Origin Adolescents' Sexual Intentions

Journal of Marriage and the Family. Feb, 2011  |  Pubmed ID: 21278903

Drawing on a symbolic-interaction perspective and a compensation model, the processes linking mother-and father-adolescent relationship qualities, deviant peer affiliations, and adolescents' sexual intentions were investigated for 246 Mexican-origin youths born in the United States and in Mexico using multiple-group structural equation models. Deviant peer affiliations significantly mediated the relations between paternal acceptance and sexual intentions and between disclosure to mothers and sexual intentions for U.S.-born youths but not for Mexico-born youths. Findings highlight the importance of examining variability as a function of youth nativity.

Energy Expenditure Characteristics of Weight Lifting: 2 Sets to Fatigue

Applied Physiology, Nutrition, and Metabolism = Physiologie Appliquée, Nutrition Et Métabolisme. Feb, 2011  |  Pubmed ID: 21326385

We investigated the work performed and energy expenditure characteristics within and among 2 sets of the bench press at 70%, 80%, and 90% of 1 repetition maximum (1RM). For both sets fatigue was the end point. We asked: do multiple sets affect subsequent work output along with aerobic, anaerobic, and excess postexercise oxygen consumption (EPOC) contributions? Ten males participated. Work was significantly less for the 2nd set within the 70% and 80% protocols, but not the 90% protocol. Anaerobic (glycolytic) energy expenditure was less for the 2nd set within all protocols. However, within all protocols, the work / energy expenditure ratio was not different between sets. Overall work was significantly different among protocols, becoming less as the weight lifted was increased: 70%, 637.1 ± 122.4 J; 80%, 512.4 ± 93.4 J; 90%, 324.7 ± 92.6 J (p < 0.001). EPOC was not different among protocols after the 1st set, 2nd set, or combined overall. Moreover, the overall EPOC did not correlate with overall work performed (r = 0.31, p = 0.11). EPOC overall did correlate with aerobic (r = 0.68, p < 0.001) and anaerobic (r = 0.65, p < 0.001) energy expenditures. In terms of a work / energy expenditure ratio, the least amount of completed work at 90% 1RM required greater energy expenditure as compared with 70% and 80% because of an EPOC that is similar for all. As more work is completed (i.e., lower weight, more repetitions), aerobic and anaerobic exercise energy expenditures appear to increase accordingly, yet absolute EPOC remains essentially unchanged, contributing less to the overall energy expenditure.

Antibody-targeted Nanoparticles for Cancer Therapy

Immunotherapy. Mar, 2011  |  Pubmed ID: 21395380

In recent years, nanoparticulate-mediated drug delivery research has examined a full spectrum of nanoparticles that can be used in diagnostic and therapeutic cancer applications. A key aspect of this technology is in the potential to specifically target the nanoparticles to diseased cells using a range of molecules, in particular antibodies. Antibody-nanoparticle conjugates have the potential to elicit effective targeting and release of therapeutic targets at the disease site, while minimizing off-target side effects caused by dosing of normal tissues. This article provides an overview of various antibody-conjugated nanoparticle strategies, focusing on the rationale of cell-surface receptors targeted and their potential clinical application.

The Deubiquitinating Enzyme USP17 is Essential for GTPase Subcellular Localization and Cell Motility

Nature Communications. 2011  |  Pubmed ID: 21448158

Deubiquitinating enzymes are now emerging as potential therapeutic targets that control many cellular processes, but few have been demonstrated to control cell motility. Here, we show that ubiquitin-specific protease 17 (USP17) is rapidly and transiently induced in response to chemokines SDF-1/CXCL12 and IL-8/CXCL8 in both primary cells and cell lines, and that its depletion completely blocks chemokine-induced cell migration and cytoskeletal rearrangements. Using live cell imaging, we demonstrate that USP17 is required for both elongated and amoeboid motility, in addition to chemotaxis. USP17 has previously been reported to disrupt Ras localization and we now find that USP17 depletion blocks chemokine-induced subcellular relocalization of GTPases Cdc42, Rac and RhoA, which are GTPases essential for cell motility. Collectively, these results demonstrate that USP17 has a critical role in cell migration and may be a useful drug target for both inflammatory and metastatic disease.

Does the Prognostic Value of Dobutamine Stress Echocardiography Differ Among Different Age Groups?

American Heart Journal. Apr, 2011  |  Pubmed ID: 21473974

Age is associated with reduced exercise capacity and greater prevalence of coronary artery disease. Whether the prognostic information obtained from dobutamine stress echocardiography (DSE), a stress test commonly used for patients unable to perform an exercise test, provides differential information based on age is not well known.

Donation of Embryos for Human Development and Stem Cell Research

Cell Stem Cell. Apr, 2011  |  Pubmed ID: 21474099

Using donated human embryos for scientific research raises ethical questions about the donation process. We describe a two-stage consent process designed to help couples make informed decisions about embryo disposition. This consent methodology minimizes conflict of interest, respects patient choice, and provides a much-needed resource to patients and the research community.

Genetic Engineering of Murine CD8+ and CD4+ T Cells for Preclinical Adoptive Immunotherapy Studies

Journal of Immunotherapy (Hagerstown, Md. : 1997). May, 2011  |  Pubmed ID: 21499127

T-cell receptor (TCR) gene therapy enables for the rapid creation of antigen-specific T cells from mice of any strain and represents a valuable tool for preclinical immunotherapy studies. Here, we describe the superiority of γ-retroviral vectors compared with lentiviral vectors for transduction of murine T cells and surprisingly illustrate robust gene-transfer into phenotypically naive/memory-stem cell like (TN/TSCM; CD62L(hi)/CD44(low)) and central memory (TCM; CD62L(hi)/CD44(hi)) CD8+ T cells using murine stem cell-based γ-retroviral vectors (MSGV1). We created MSGV1 vectors for a major histocompatibility complex-class I-restricted TCR specific for the melanocyte-differentiation antigen, glycoprotein 100 (MSGV1-pmel-1), and a major histocompatibility complex-class II-restricted TCR specific for tyrosinase-related protein-1 (MSGV1-TRP-1), and found that robust gene expression required codon optimization of TCR sequences for the pmel-1 TCR. To test for functionality, we adoptively transferred TCR-engineered T cells into mice bearing B16 melanomas and observed delayed growth of established tumors with pmel-1 TCR engineered CD8+ T cells and significant tumor regression with TRP-1 TCR transduced CD4 T cells. We simultaneously created lentiviral vectors encoding the pmel-1 TCR, but found that these vectors mediated low TCR expression in murine T cells, but robust gene expression in other murine and human cell lines. These results indicate that preclinical murine models of adoptive immunotherapies are more practical using γ-retroviral rather than lentiviral vectors.

Apical Hypertrophic Cardiomyopathy: Prevalence and Correlates of Apical Outpouching

Journal of the American Society of Echocardiography : Official Publication of the American Society of Echocardiography. Jul, 2011  |  Pubmed ID: 21511435

Apical outpouching, including wall motion abnormalities and aneurysms, has been described in apical hypertrophic cardiomyopathy (ApHCM).

Relation of Natriuretic Peptide Concentrations to Central Sleep Apnea in Patients with Heart Failure

Chest. Dec, 2011  |  Pubmed ID: 21636668

Central sleep apnea (CSA) is frequent among patients with heart failure (HF) and associated with increased morbidity and mortality. Elevated cardiac filling pressures promote CSA and atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) secretion. We hypothesized that circulating natriuretic peptide concentrations predict CSA.

Democracy Derived? New Trajectories in Pluripotent Stem Cell Research

Cell. Jun, 2011  |  Pubmed ID: 21663787

How has the development of human induced pluripotent stem cells (hiPSCs) modified the trajectory of stem cell research? Here, coauthorship networks of stem cell research articles and analysis of cell lines used in stem cell research indicate that hiPSCs are not replacing human embryonic stem cells, but instead, the two cell types are complementary, interdependent research tools. Thus, we conclude that a ban on funding for embryonic stem cell research could have unexpected negative ramifications on the nascent field of hiPSCs.

Determinants of Successful CD8+ T-cell Adoptive Immunotherapy for Large Established Tumors in Mice

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Aug, 2011  |  Pubmed ID: 21737507

Adoptive cell transfer (ACT) of tumor infiltrating or genetically engineered T cells can cause durable responses in patients with metastatic cancer. Multiple clinically modifiable parameters can comprise this therapy, including cell dose and phenotype, in vivo antigen restimulation, and common gamma-chain (γ(c)) cytokine support. However, the relative contributions of each these individual components to the magnitude of the antitumor response have yet to be quantified.

Comprehensive Inhibitor Profiling of the Proteus Mirabilis Metalloprotease Virulence Factor ZapA (mirabilysin)

Biochimie. Oct, 2011  |  Pubmed ID: 21762758

In this study we report for the first time the comprehensive inhibitor profiling of the Proteus mirabilis metalloprotease virulence factor ZapA (mirabilysin) using a 160 compound focused library of N-alpha mercaptoamide dipeptides, in order to map the S(1)(') and S(2)(') binding site preferences of this important enzyme. This study has revealed a preference for the aromatic residues tyrosine and tryptophan in P(1)(') and aliphatic residues in P(2)('). From this library, six compounds were identified which exhibited sub- to low-micromolar K(i) values. The most potent inactivator, SH-CO(2)-Y-V-NH(2) was capable of preventing ZapA-mediated hydrolysis of heat-denatured IgA, indicating that these inhibitors may be capable of protecting host proteins against ZapA during colonisation and infection.

Stable Expression and Purification of a Functional Processed Fab' Fragment from a Single Nascent Polypeptide in CHO Cells Expressing the MCAT-1 Retroviral Receptor

Journal of Immunological Methods. Sep, 2011  |  Pubmed ID: 21782818

Monoclonal antibodies and derivative formats such as Fab' fragments are used in a broad range of therapeutic, diagnostic and research applications. New systems and methodologies that can improve the production of these proteins are consequently of much interest. Here we present a novel approach for the rapid production of processed Fab' fragments in a CHO cell line that has been engineered to express the mouse cationic amino acid transporter receptor 1 (mCAT-1). This facilitated the introduction of the target antibody gene through retroviral transfection, rapidly producing stable expression. Using this system, we designed a single retroviral vector construct for the expression of a target Fab' fragment as a single polypeptide with a furin cleavage site and a FMDV 2A self-cleaving peptide introduced to bridge the light and truncated heavy chain regions. The introduction of these cleavage motifs ensured equimolar expression and processing of the heavy and light domains as exemplified by the production of an active chimeric Fab' fragment against the Fas receptor, routinely expressed in 1-2mg/L yield in spinner-flask cell cultures. These results demonstrate that this method could have application in the facile production of bioactive Fab' fragments.

Prospective Comparison of Echocardiography Versus Cardiac Magnetic Resonance Imaging in Patients with Ebstein's Anomaly

The International Journal of Cardiovascular Imaging. Aug, 2011  |  Pubmed ID: 21822629

Ebstein's anomaly (EA) is primarily diagnosed by echocardiography. The purpose of this study was to compare echocardiography and magnetic resonance imaging (MRI) in EA. Data from cardiac MRI and echocardiography were prospectively collected from 16 patients with EA. Imaging data also were compared with intraoperative findings. Information provided by MRI and echocardiography were comparable for left ventricular size and function, tricuspid valve repairability, qualitative assessment of right-sided cavities, and visibility of septal and anterior tricuspid valve leaflets. The posterior tricuspid valve leaflet and tricuspid valve fenestrations were better visualized with MRI; associated heart defects were equally recognized, apart from small shunts that tended to be more readily diagnosed with echocardiography. Quantification of right-cavity size and right ventricular ejection fraction was possible only with cardiac MRI. The degree of tricuspid valve regurgitation was underestimated by echocardiography (2 patients) and by MRI (4 patients) when compared with intraoperative assessment. When evaluating EA, echocardiography and MRI provide complementary data. For visualization of the posterior tricuspid valve leaflet and quantitative assessment of right ventricular size and function, MRI is preferable. For appropriate risk stratification in EA, both MRI and echocardiography should be performed before cardiac surgery.

Conatumumab (AMG 655) Coated Nanoparticles for Targeted Pro-apoptotic Drug Delivery

Biomaterials. Nov, 2011  |  Pubmed ID: 21875750

Colloidal nanoparticle drug delivery systems have attracted much interest for their ability to enable effective formulation and delivery of therapeutic agents. The selective delivery of these nanoparticles to the disease site can be enhanced by coating the surface of the nanoparticles with targeting moieties, such as antibodies. In this current work, we demonstrate that antibodies on the surface of the particles can also elicit key biological effects. Specifically, we demonstrate the induction of apoptosis in colorectal HCT116 cancer cells using PLGA nanoparticles coated with Conatumumab (AMG 655) death receptor 5-specific antibodies (DR5-NP). We show that DR5-NP preferentially target DR5-expressing cells and present a sufficient density of antibody paratopes to induce apoptosis via DR5, unlike free AMG 655 or non-targeted control nanoparticles. We also demonstrate that DR5-targeted nanoparticles encapsulating the cytotoxic drug camptothecin are effectively targeted to the tumour cells, thereby producing enhanced cytotoxic effects through simultaneous drug delivery and apoptosis induction. These results demonstrate that antibodies on nanoparticulate surfaces can be exploited for dual modes of action to enhance the therapeutic utility of the modality.

Caustic Injury Due to Unintentional Ingestion of a Cooking Adjunct

The Journal of Emergency Medicine. Jun, 2011  |  Pubmed ID: 19596178

Human Effector CD8+ T Cells Derived from Naive Rather Than Memory Subsets Possess Superior Traits for Adoptive Immunotherapy

Blood. Jan, 2011  |  Pubmed ID: 20971955

Cluster of differentiation (CD)8(+) T cells exist as naive, central memory, and effector memory subsets, and any of these populations can be genetically engineered into tumor-reactive effector cells for adoptive immunotherapy. However, the optimal subset from which to derive effector CD8(+) T cells for patient treatments is controversial and understudied. We investigated human CD8(+) T cells and found that naive cells were not only the most abundant subset but also the population most capable of in vitro expansion and T-cell receptor transgene expression. Despite increased expansion, naive-derived cells displayed minimal effector differentiation, a quality associated with greater efficacy after cell infusion. Similarly, the markers of terminal differentiation, killer cell lectin-like receptor G1 and CD57, were expressed at lower levels in cells of naive origin. Finally, naive-derived effector cells expressed higher CD27 and retained longer telomeres, characteristics that suggest greater proliferative potential and that have been linked to greater efficacy in clinical trials. Thus, these data suggest that naive cells resist terminal differentiation, or "exhaustion," maintain high replicative potential, and therefore may be the superior subset for use in adoptive immunotherapy.

Family and Cultural Correlates of Mexican-origin Youths' Sexual Intentions

Journal of Youth and Adolescence. Jun, 2011  |  Pubmed ID: 20835919

Understanding how culture and familial relationships are related to Mexican-origin youths' normative sexual development is important. Using cultural-ecological, sexual scripting, and risk and resilience perspectives, the associations between parent-adolescent relationship characteristics, adolescents' cultural orientations and familism values, and sexual intentions among 246 Mexican-origin adolescents (50% female) were investigated. Regression analyses were conducted to examine the connections between youths' cultural orientations and familism values and their intentions to engage in sexual intercourse and to test the moderating role of parent-adolescent relationship characteristics and adolescent sex. For boys, under conditions of high maternal acceptance, higher Anglo orientations and higher Mexican orientations were related to greater sexual intentions. For girls, familism values played a protective role and were related to fewer sexual intentions when girls spent less time with their parents. The findings highlight the complex nature of relationships between culture, family relationships, and youths' sexual intentions and different patterns for girls versus boys.

Aerobic, Anaerobic, and Excess Postexercise Oxygen Consumption Energy Expenditure of Muscular Endurance and Strength: 1-set of Bench Press to Muscular Fatigue

Journal of Strength and Conditioning Research / National Strength & Conditioning Association. Apr, 2011  |  Pubmed ID: 20703175

We use a new approach to the estimation of energy expenditure for resistance training involving nonsteady state measures of work (weight × displacement), exercise O2 uptake, blood lactate, and recovery O2 uptake; all lifts were performed to muscular failure. Our intent was to estimate and compare absolute and relative aerobic and anaerobic exercise energy expenditure and recovery energy expenditure. Single-set bench press lifts of ∼ 37, ∼ 46, and ∼ 56% (muscular endurance-type exercise) along with 70, 80, and 90% (strength-type exercise) of a 1 repetition maximum were performed. Collectively, the muscular endurance lifts resulted in larger total energy expenditure (60.2 ± 14.5 kJ) as compared with the strength lifts (43.2 ± 12.5 kJ) (p = 0.001). Overall work also was greater for muscular endurance (462 ± 131 J) as opposed to strength (253 ± 93 J) (p = 0.001); overall work and energy expenditure were related (r = 0.87, p = 0.001). Anaerobic exercise and recovery energy expenditure were significantly larger for all strength lifts as compared with aerobic exercise energy expenditure (p < 0.001). For the muscular endurance lifts, anaerobic energy expenditure was larger than recovery energy expenditure (p < 0.001) that in turn was larger than aerobic exercise energy expenditure (p < 0.001). We conclude that for a single set of resistance training to fatigue, the anaerobic and recovery energy expenditure contributions can be significantly larger than aerobic energy expenditure during the exercise. To our surprise, recovery energy expenditure was similar both within strength and muscular-endurance protocols and between protocols; moreover, recovery energy expenditure had little to no relationship with aerobic and anaerobic exercise energy expenditure or work.

Quantifying the Immediate Recovery Energy Expenditure of Resistance Training

Journal of Strength and Conditioning Research / National Strength & Conditioning Association. Apr, 2011  |  Pubmed ID: 20733523

As opposed to steady state aerobic-type exercise involving long duration, continuous, rhythmic, large muscle group activities that consume large volumes of oxygen, a resistance training set is brief, intermittent, uses multiple and isolated muscles, and is considered anaerobic in description. Because differences are evident between aerobic- and anaerobic-type exercise, it is proposed that the methods used for estimating resistance training energy expenditure should be different as compared with walking, jogging, cycling, etc. After a single set of weight lifting, for example, oxygen uptake is greater in the recovery from lifting as opposed to during the actual exercise; likewise, the anaerobic energy expenditure contribution to lifting may exceed exercise oxygen uptake. Recovery energy expenditure also does not appear well related to the anaerobic energy expenditure of the previous exercise. Based on this evidence, it is suggested that anaerobic-type exercise should not be based on aerobic-type models. In terms of excess postexercise oxygen consumption, a hypothesis is presented in regard to how non-steady-state energy expenditure in the immediate recovery from intense exercise should be properly quantified (e.g., in-between resistance training sets). The proposed concept is based on possible substrate or fuel use differences during intense exercise and aerobic recovery and the biochemistry and bioenergetics of glucose, lactate, and fat oxidation. It is proposed that immediately after a single weight lifting bout or in-between resistance training sets, as O2 uptake plummets rapidly back toward pre-exercise levels, a separate energy expenditure conversion is required for recovery that differs from non-steady-state exercise, that is, 1 L of recovery oxygen uptake = 19.6 kJ (4.7 kcal) (not the standard exercise conversion of 1 L of oxygen uptake = 21.1 kJ) (5.0 kcal).

Unsettled Expectations: How Recent Patent Decisions Affect Biotech

Nature Biotechnology. Mar, 2011  |  Pubmed ID: 21390025

What is Your Diagnosis? Craniodorsal Luxation

Journal of the American Veterinary Medical Association. Aug, 2011  |  Pubmed ID: 21801040

Going Viral

Nature Biotechnology. Nov, 2011  |  Pubmed ID: 22068529

The European Court of Justice Ruling in Brüstle V. Greenpeace: the Impacts on Patenting of Human Induced Pluripotent Stem Cells in Europe

Cell Stem Cell. Dec, 2011  |  Pubmed ID: 22136925

The First Cryoprobe - Some Recollections

Journal of Magnetic Resonance (San Diego, Calif. : 1997). Dec, 2011  |  Pubmed ID: 22152354

Antibody Targeting of Cathepsin S Induces Antibody-dependent Cellular Cytotoxicity

Molecular Cancer. 2011  |  Pubmed ID: 22168338

ABSTRACT:

Design, Optimization and Characterisation of Polymeric Microneedle Arrays Prepared by a Novel Laser-based Micromoulding Technique

Pharmaceutical Research. Jan, 2011  |  Pubmed ID: 20490627

Design and evaluation of a novel laser-based method for micromoulding of microneedle arrays from polymeric materials under ambient conditions. The aim of this study was to optimise polymeric composition and assess the performance of microneedle devices that possess different geometries.

Aromatase Immunoreactivity is Increased in Mammographically Dense Regions of the Breast

Breast Cancer Research and Treatment. Jan, 2011  |  Pubmed ID: 20526739

Mammographic breast density (MBD) is one of the strongest risk factors for breast cancer. Unfortunately, the biologic basis underlying this association is unknown. This study compared aromatase expression or immunoreactivity (IR) in core biopsies from mammographically dense versus non-dense regions of the breast to examine whether estrogen synthesis in the breast is associated with MBD and one possible mechanism through which MBD may influence breast cancer. Eligible participants were 40+ years, had a screening mammogram with visible MBD and no prior cancer or current endocrine therapy. Mammograms were used to identify dense and non-dense regions and ultrasound-guided core biopsies were performed to obtain tissue from these regions. Immunostaining for aromatase employed the streptavidin-biotin amplification method and #677 mouse monoclonal antibody. Aromatase IR was scored in terms of extent and intensity of staining for each cell type (stroma, epithelium, adipocytes) on histologic sections. A modified histological H-score provided quantitation of aromatase IR in each cell type and overall. Repeated measure analyses evaluated average differences (β(H)) in H-score in dense versus non-dense tissue within and across cell types. Forty-nine women with mean age 50 years (range: 40-82), participated. Aromatase IR was increased in dense (vs. non-dense) tissue in both the stroma (β(H) = 0.58) and epithelium (β(H) = 0.12) (P < 0.01). Adipocytes from non-dense tissue, however, had a greater IR compared to those from dense tissue (β(H) = -0.24, P < 0.01). An overall H-score which integrated results from all cell types demonstrated that aromatase IR was twice as great for dense (mean H-score = 0.90, SD = 0.53) versus non-dense (mean H-score = 0.45, SD = 0.39) breast tissue (β(H) = 0.45; P < 0.001). Overall, aromatase IR was greater for mammographically dense versus non-dense tissue and may partly explain how MBD influences breast cancer.

Tissue Composition of Mammographically Dense and Non-dense Breast Tissue

Breast Cancer Research and Treatment. Jan, 2012  |  Pubmed ID: 21877142

Mammographic density is a strong risk factor for breast cancer but its underlying biology in healthy women is not well-defined. Using a novel collection of core biopsies from mammographically dense versus non-dense regions of the breasts of healthy women, we examined histologic and molecular differences between these two tissue types. Eligible participants were 40 + years, had a screening mammogram and no prior breast cancer or current endocrine therapy. Mammograms were used to identify dense and non-dense regions and ultrasound-guided core biopsies were performed to obtain tissue from these regions. Quantitative assessment of epithelium, stroma, and fat was performed on dense and non-dense cores. Molecular markers including Ki-67, estrogen receptor (ER) and progesterone receptor (PR) were also assessed for participants who had >0% epithelial area in both dense and non-dense tissue. Signed rank test was used to assess within woman differences in epithelium, stroma and fat between dense and non-dense tissue. Differences in molecular markers (Ki-67, ER, and PR) were analyzed using generalized linear models, adjusting for total epithelial area. Fifty-nine women, mean age 51 years (range: 40-82), were eligible for analyses. Dense tissue was comprised of greater mean areas of epithelium and stroma (1.1 and 9.2 mm(2) more, respectively) but less fat (6.0 mm(2) less) than non-dense tissue. There were no statistically significant differences in relative expression of Ki-67 (P = 0.82), ER (P = 0.09), or PR (P = 0.96) between dense and non-dense tissue. Consistent with prior reports, we found that mammographically dense areas of the breast differ histologically from non-dense areas, reflected in greater proportions of epithelium and stroma and lesser proportions of fat in the dense compared to non-dense breast tissue. Studies of both epithelial and stromal components are important in understanding the association between mammographic density and breast cancer risk.

Inhibition of Cathepsin S by Fsn0503 Enhances the Efficacy of Chemotherapy in Colorectal Carcinomas

Biochimie. Feb, 2012  |  Pubmed ID: 21896304

Cathepsin S is a lysosomal cysteine protease implicated in tumourigenesis with key roles in invasion and angiogenesis. We have previously shown that the specific inhibition of Cathepsin S using a monoclonal antibody (Fsn0503) blocks colorectal carcinoma tumour growth and angiogenesis in vivo. We investigated whether Cathepsin S expression levels were affected by chemotherapy in human cancer cell lines by RT-PCR. Using colorectal xenograft models, we examined the therapeutic benefit of Cathepsin S inhibition using Fsn0503 in combination with a metronomic dosing regimen of CPT-11. We analysed the effects of the combination therapy on tumour progression and on tumour vascularisation by immunohistochemical staining of tumours. Cathepsin S expression levels are upregulated in HCT116, LoVo, Colo205 cell lines and HUVECs after exposure to CPT-11 in vitro. The administration of Fsn0503 in combination with CPT-11 significantly attenuated tumour growth in comparison to CPT-11 alone in colorectal HCT116 xenograft models. Furthermore, analysis of tumour vascularisation revealed that this was also significantly disrupted by the combination treatment. These results show that the combination of Cathepsin S inhibition with CPT-11 enhances the therapeutic effect of the chemotherapy. This rationale may have clinical application in the treatment of colorectal cancer upon further evaluation.

Recent Advances in the Application of Antibodies As Therapeutics

Future Medicinal Chemistry. Jan, 2012  |  Pubmed ID: 22168165

The application of antibodies as therapeutic agents in the treatment of cancer now represents a significant proportion of the oncology drug arena. Despite this success, the ability to engineer and exploit antibodies in many different formats is ensuring that new avenues for their therapeutic application are constantly being examined. This review examines a selection of novel antibody-based therapeutic strategies that are currently in late preclinical and clinical evaluation.

Relationship Between Diastolic Function and Heart Rate Recovery After Symptom-limited Exercise

Journal of Cardiac Failure. Jan, 2012  |  Pubmed ID: 22196839

Autonomic abnormalities have been implicated in both diastolic dysfunction and abnormal heart rate (HR) recovery; however, few studies have assessed whether diastolic dysfunction is associated with abnormal HR recovery and whether both modify exercise capacity.

No Evidence for Association of Inherited Variation in Genes Involved in Mitosis and Percent Mammographic Density

Breast Cancer Research : BCR. Jan, 2012  |  Pubmed ID: 22226020

ABSTRACT: INTRODUCTION: Increased mammographic breast density is one of the strongest risk factors for breast cancer. While two-thirds of the variation in mammographic density appears to be genetically influenced, few variants have been identified. We examined the association of inherited variation in genes from pathways that mediate cell division with percent mammographic density (PMD) adjusted for age, body mass index (BMI) and postmenopausal hormones, in two studies of healthy postmenopausal women. METHODS: We investigated 2,058 single nucleotide polymorphisms (SNPs) in 378 genes involved in regulation of mitosis for associations with adjusted PMD among 484 unaffected postmenopausal controls (without breast cancer) from the Mayo Clinic Breast Cancer Study (MCBCS) and replicated the findings in postmenopausal controls (n = 726) from the Singapore and Sweden Breast Cancer Study (SASBAC) study. PMD was assessed in both studies by a computer-thresholding method (Cumulus) and linear regression approaches were used to assess the association of SNPs and PMD, adjusted for age, BMI and postmenopausal hormones. A P-value threshold of 4.2 × 10-5 based on a Bonferroni correction of effective number of independent tests was used for statistical significance. Further, a pathway-level analysis was conducted of all 378 genes using the self-contained gene-set analysis method GLOSSI. RESULTS: A variant in PRPF4, rs10733604, was significantly associated with adjusted PMD in the MCBCS (P = 2.7 × 10-7), otherwise, no single SNP was associated with PMD. Additionally, the pathway analysis provided no evidence of enrichment in the number of associations observed between SNPs in the mitotic genes and PMD (P = 0.60). We evaluated rs10733604 (PRPF4), and 73 other SNPs at P < 0.05 from 51 genes in the SASBAC study. There was no evidence of an association of rs10733604 (PRPF4) with adjusted PMD in SASBAC (P = 0.23). There were, however, consistent associations (P < 0.05) of variants at the putative locus, LOC375190, Aurora B kinase (AURKB), and Mini-chromosome maintenance complex component 3 (MCM3) with adjusted PMD, although these were not statistically significant. CONCLUSIONS: Our findings do not support a role of inherited variation in genes involved in regulation of cell division and adjusted percent mammographic density in postmenopausal women.

Mammographic Breast Density and Breast Cancer: Evidence of a Shared Genetic Basis

Cancer Research. Jan, 2012  |  Pubmed ID: 22266113

Percent mammographic breast density (PMD) is a strong heritable risk factor for breast cancer. However, the pathways through which this risk is mediated are still unclear. To explore whether PMD and breast cancer have a shared genetic basis, we identified genetic variants most strongly associated with PMD in a published meta-analysis of five genome-wide association studies (GWAS) and used these to construct risk scores for 3628 breast cancer cases and 5190 controls from the UK2 GWAS of breast cancer. The signed per-allele effect estimates of SNPs were multiplied with the respective allele counts in the individual and summed over all SNPs to derive the risk score for an individual. These scores were included as the exposure variable in a logistic regression model with breast cancer case-control status as the outcome. This analysis was repeated using ten different cut-offs for the most significant density SNPs (1-10% representing 5,222-50,899 SNPs). Permutation analysis was also performed across all 10 cut-offs. The association between risk score and breast cancer was significant for all cut-offs from 3-10% of top density SNPs, being most significant for the 6% (2-sided P=0.002) to 10% (P=0.001) cut-offs (overall permutation P=0.003). Women in the top 10% of the risk score distribution had a 31% increased risk of breast cancer [OR= 1.31 (95%CI 1.08-1.59)] compared to women in the bottom 10%. Together, our results demonstrate that PMD and breast cancer have a shared genetic basis that is mediated through a large number of common variants.

Comparison of Right Ventricular Longitudinal Strain Imaging, Tricuspid Annular Plane Systolic Excursion, and Cardiac Biomarkers for Early Diagnosis of Cardiac Involvement and Risk Stratification in Primary Systematic (AL) Amyloidosis: a 5-year Cohort Study

European Heart Journal Cardiovascular Imaging. Feb, 2012  |  Pubmed ID: 22307866

AIMS: To determine the role of assessing right ventricular (RV) function, using standard echocardiography and Doppler myocardial imaging (DMI), in the early diagnosis of cardiac amyloidosis and in the prediction of mortality. METHODS AND RESULTS: Patients with primary systemic (AL) amyloidosis seen at our institution from 1 February 2004 through 31 October 2005 (N = 249) were categorized by left ventricular thickness and E' velocity and compared with 38 age- and sex-matched controls. Standard echocardiographic and DMI examination were used to measure echocardiographic parameters of RV function: systolic tissue velocity, strain rate, and strain were determined for basal and middle RV free wall segments. Patients were followed up for the endpoint of mortality. RV tricuspid annular plane systolic excursion (TAPSE) and all DMI measurements were lower in patients with AL amyloidosis and normal echocardiography results (AL-normal-echo group) than controls. A bivariate model including strain of the basal segment of the RV free wall and TAPSE was the best for distinguishing AL-normal-echo patients from controls. Male sex [hazard ratio (HR), 2.2; P= 0.005], brain natriuretic peptide levels (HR 1.4; P= 0.003), troponin T levels (HR 1.6; P= 0.01), pleural effusion (HR 3.6; P< 0.001), E/A ratio (HR 1.3; P= 0.006), RV systolic pressure (HR 1.02; P= 0.01), and RV strain rate of the middle segment (HR 1.3; P= 0.02) were independent predictors of death. CONCLUSION: DMI measures of the RV can identify early impairment of cardiac function or stratify risk of death in patients with AL amyloidosis. Further studies with longer follow-up are warranted to confirm these results.

Personal Medicine-the New Banking Crisis

Nature Biotechnology. 2012  |  Pubmed ID: 22318029

As the healthcare industry moves from a twentieth century approach of providing treatments of last resort to a future of individualized medicine, biobanks will play a pivotal role in this transition. Yet at the cutting edge of biobanking research are new ethical, social and policy challenges beyond those familiar to basic biomedical research.

Aortic Valve Stenosis in Community Medical Practice: Determinants of Outcome and Implications for Aortic Valve Replacement

The Journal of Thoracic and Cardiovascular Surgery. Feb, 2012  |  Pubmed ID: 22336754

OBJECTIVE: To define the objective and subjective measures of aortic stenosis (AS) severity linked to survival after diagnosis in community practice. METHODS: All 360 Olmsted County, Minnesota residents (74 ± 14 years; 44% men) with AS diagnosed from 1988 to 1997 by echocardiography and without life-threatening comorbid conditions were enrolled. The presentation at first diagnosis, outcomes (mortality, heart failure, cardiac surgery), and coherence of guideline-based criteria for severe AS were analyzed. RESULTS: The presentation was challenging. Cardiac symptoms were frequent (59%) and unassociated with the AS severity (all P > .13). Of the patients with severe AS, as determined by a valve area less than 1.0 cm(2), 67% had low gradient AS (≤40 mm Hg). An aortic valve area less than 1.0 cm(2) was the only objective measure independently determining survival (adjusted risk ratio, 1.81; 95% confidence interval [CI], 1.19-2.70; P < .01) and heart failure (adjusted risk ratio, 2.3; 95% CI, 1.3-4.0; P < .01), even in patients with low-gradient AS and/or an ejection fraction of 50% or greater. Excess mortality (vs expected mortality) occurred with an aortic valve area of less than 1.0 cm(2) (risk ratio, 1.78; 95% CI, 1.33-2.35; P < .001) even without symptoms (risk ratio, 1.65; 95% CI, 1.05-2.47; P = .02). Aortic valve replacement, ultimately performed in only 45% of those with an aortic valve area less than 1.0 cm(2), reduced mortality (risk ratio, 0.61; 95% CI, 0.39-0.94; P = .02) and heart failure (risk ratio, 0.29; 95% CI, 0.13-0.64; P < .01). CONCLUSIONS: In community practice, AS affects elderly patients, and its presentation is challenging owing to the high frequency of low-gradient severe AS despite a normal ejection fraction and because symptoms are frequently not specific to AS. Consequently, aortic valve replacement is seldom performed despite its considerable benefit. Physicians should be aware that an aortic valve area of less than 1.0 cm(2) predicts for unfavorable outcomes, irrespective of symptoms or gradient. Thus, such patients should undergo a thorough evaluation to detect those who could benefit from aortic valve replacement, despite their challenging presentation.