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Find video protocols related to scientific articles indexed in Pubmed.
Attenuated Listeria monocytogenes Vectors Overcome Suppressive Plasma Factors during HIV Infection to Stimulate Myeloid Dendritic Cells to Promote Adaptive Immunity and Reactivation of Latent Virus.
AIDS Res. Hum. Retroviruses
PUBLISHED: 11-07-2014
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HIV-1 infection is characterized by myeloid dendritic cell (DC) dysfunction which blunts their responsiveness to vaccine adjuvants. We previously showed that non-viral factors in HIV-seropositive plasma are partially responsible for mediating this immune suppression. In this study we investigated recombinant Listeria monocytogenes (Lm) vectors, which naturally infect and potently activate DCs from seronegative donors, as a means to overcome DC dysfunction associated with HIV infection. Monocyte-derived DCs were cocultured with plasma from HIV-infected donors (HIV-moDCs) to induce a dysregulated state and infected with an attenuated, non-replicative vaccine strain of Lm expressing full length clade B consensus gag (KBMA Lm-gag). Lm infection stimulated cytokine secretion (IL-12p70, TNF?, IL-6) and Th-1 skewing of allogeneic naïve CD4 T cells by HIV-moDCs, in contrast to the suppressive effects observed by HIV plasma on moDCs upon toll-like receptor ligand stimulation. Upon coculture of KBMA Lm-gag-infected moDCs from HIV-infected donors with autologous cells, expansion of polyfunctional, gag-specific CD8+ T cells was observed. Reactivation of latent proviruses by moDCs following Lm infection was also observed in models of HIV latency in a TNF?-dependent manner. These findings reveal the unique ability of Lm vectors to contend with dysregulation of HIV-moDCs , while simultaneously possessing the capacity to activate latent virus. Concurrent stimulation of innate and adaptive immunity and disruption of latency may be an approach to reduce the pool of latently infected cells during HIV infection. Further study of Lm vectors as part of therapeutic vaccination and eradication strategies may advance this evolving field.
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Inferring viral dynamics in chronically HCV infected patients from the spatial distribution of infected hepatocytes.
PLoS Comput. Biol.
PUBLISHED: 11-01-2014
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Chronic liver infection by hepatitis C virus (HCV) is a major public health concern. Despite partly successful treatment options, several aspects of intrahepatic HCV infection dynamics are still poorly understood, including the preferred mode of viral propagation, as well as the proportion of infected hepatocytes. Answers to these questions have important implications for the development of therapeutic interventions. In this study, we present methods to analyze the spatial distribution of infected hepatocytes obtained by single cell laser capture microdissection from liver biopsy samples of patients chronically infected with HCV. By characterizing the internal structure of clusters of infected cells, we are able to evaluate hypotheses about intrahepatic infection dynamics. We found that individual clusters on biopsy samples range in size from [Formula: see text] infected cells. In addition, the HCV RNA content in a cluster declines from the cell that presumably founded the cluster to cells at the maximal cluster extension. These observations support the idea that HCV infection in the liver is seeded randomly (e.g. from the blood) and then spreads locally. Assuming that the amount of intracellular HCV RNA is a proxy for how long a cell has been infected, we estimate based on models of intracellular HCV RNA replication and accumulation that cells in clusters have been infected on average for less than a week. Further, we do not find a relationship between the cluster size and the estimated cluster expansion time. Our method represents a novel approach to make inferences about infection dynamics in solid tissues from static spatial data.
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Dextrin-Colistin Conjugates as a Model Bioresponsive Treatment for Multidrug Resistant Bacterial Infections.
Mol. Pharm.
PUBLISHED: 11-01-2014
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Polymer therapeutics offer potential benefits in the treatment of multidrug resistant (MDR) infections; affording targeted delivery of biologically active agents to the site of inflammation, potential decreases in systemic toxicity, and the retention of antimicrobial activity at the target site. As a prototype model, these studies developed and characterized a library of dextrin-colistin conjugates (dextrin molecular weight: 7500-48?000 g/mol) as a means of targeting the delivery of colistin. Optimum colistin release kinetics (following dextrin degradation by physiological concentrations of amylase (100 IU/L)) were observed in conjugates containing low molecular weight (?7500 g/mol) dextrin with ?1 mol % succinoylation (?80% drug release within 48 h, compared to ?33% from sodium colistin methanesulfonate (CMS, Colomycin)). These conjugates exhibited comparable antimicrobial activity to CMS in conventional MIC assays against a range of Gram-negative pathogens, but with significantly reduced in vitro toxicity toward kidney (IC50 = CMS, 15.4 ?g/mL; dextrin-colistin, 63.9 ?g/mL) and macrophage (IC50 = CMS, 111.3 ?g/mL; dextrin-colistin, 303.9 ?g/mL) cells. In vivo dose-escalation studies in rats demonstrated improved pharmacokinetics of the conjugates, with prolonged plasma levels of colistin (t1/2 135-1271 min vs 53 min) and decreased toxicity, compared to colistin sulfate. These studies highlight the potential utility of "nanoantibiotic" polymer therapeutics to aid the safe, effective, and targeted delivery of colistin in the management of MDR infections.
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Clearance of hepatitis C infection is associated with the early appearance of broad neutralizing antibody responses.
Hepatology
PUBLISHED: 09-30-2014
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The contribution of humoral immune responses to spontaneous control of hepatitis C virus (HCV) infection remains unclear. We assessed neutralizing antibody (nAb) responses during acute HCV infection to determine whether infection outcome is associated with the nAb response, specifically, its timing or breadth (neutralization of multiple genotype-matched variants). A representative genotype 1 HCV pseudoparticle (HCVpp) library, consisting of 19 genetically distinct genotype 1 HCVpp that comprise the natural variability of genotype 1 E1E2 sequences, was used to assess anti-genotype 1 nAb responses during acute infection in at-risk persons followed prospectively. Neutralization of individual library HCVpp by the last viremic plasma sample obtained before clearance was compared to either 1-year post-initial viremia or clearance time-matched specimens obtained from subjects developing persistent infection. In persistently infected persons nAb responses were delayed then progressively broadened, whereas in persons who controlled viremia broader responses were detected early and contracted after clearance of viremia. Surprisingly, the breadth of anti-genotype 1 nAb responses was not dependent on subjects' infection genotype. Also, individual library HCVpp neutralization sensitivity was not associated with any known E2 sequence determinants. Interestingly, two single nucleotide polymorphisms in the HLA-DQ locus were associated with nAb breadth.
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Gender differences and age-specific associations between body mass index and other cardiovascular risk factors in CMV infected and uninfected people.
Immunol. Lett.
PUBLISHED: 09-07-2014
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Body mass index (BMI) is a known risk factor for cardiovascular disease and cancer. It is also related to white blood count (WBC) and inflammation. The effects of age and gender on these associations have not been explored. Here we have examined the relationships between BMI and inflammatory parameters/cardiovascular risk factors including WBC/neutrophil count (NC), CRP and mean arterial blood pressure (MAP), in young (20-35 years) and older (60-85 years) healthy donors with respect to gender and CMV IgG serology. In young but not older people significant associations between BMI and WBC were observed, however, with opposite directions in the two genders. Only in CMV+ older women a positive trend was preserved. Across the population, there was no significant association between NC and MAP; however, among older men we saw a positive correlation between the two parameters. Linear regression confirmed that across the whole population, age group (young versus older) and also the interaction between gender and age group but not gender alone had significant effects on this association. When analysing CMV+ older people separately we established that both NC and its interaction with gender had a significant effect on MAP. This study reveals that the correlations between common inflammatory markers/cardiovascular risk factors depend on age, gender, and CMV status in a complex fashion. Our findings support the need to evaluate risk factors independently in men and women and to take into account CMV infection status. More focused studies will be required to shed light on these novel findings.
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Effect of a Family-Centered, Secondhand Smoke Intervention to Reduce Respiratory Illness in Indigenous Infants in Australia and New Zealand: A Randomized Controlled Trial.
Nicotine Tob. Res.
PUBLISHED: 08-25-2014
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Secondhand smoke (SHS) is a significant cause of acute respiratory illness (ARI) and 5 times more common in indigenous children. A single-blind randomized trial was undertaken to determine the efficacy of a family centered SHS intervention to reduce ARI in indigenous infants in Australia and New Zealand.
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Nodular sclerosing Hodgkin's lymphoma with breast involvement: Case report and review of the literature.
J Nat Sci Biol Med
PUBLISHED: 08-07-2014
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Extranodal disease in Hodgkin's lymphoma (HL) is very rare and it occurs in 15-30% of all cases. The intrathoracic area is the most common extranodal presentation. There are very few cases in the medical literature of breast involvement with HL. We report a 25-year-old woman who had been managed and treated for nodular sclerosing HL for 6 months, but she was noncompliant with chemotherapy. She presented 1 year later with a palpable left breast mass and B symptoms. The fluorine-18 fluorodeoxyglucose-positron emission tomography images revealed disseminated disease with a left breast mass demonstrating fluorodeoxyglucose uptake. Histopathology of the ultrasound-guided biopsy specimen of the breast mass was consistent with recurrence. This case highlights the need for an awareness of HL presenting in this way because the diagnosis has therapeutic and prognostic implications.
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Antiretroviral treatment of adult HIV infection: 2014 recommendations of the International Antiviral Society-USA Panel.
JAMA
PUBLISHED: 07-20-2014
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New data and antiretroviral regimens expand treatment choices in resource-rich settings and warrant an update of recommendations to treat adults infected with human immunodeficiency virus (HIV).
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0347?Possible pro-carcinogenic effect of endotoxin on lung cancer in an extended follow-up of Shanghai women textile workers.
Occup Environ Med
PUBLISHED: 07-15-2014
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To examine further the association between endotoxin and risk of lung cancer among Shanghai women textile workers in an extended follow-up of the cohort. The initial follow-up indicated an inverse exposure-response relation.
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Gender differences and age-specific associations between Body Mass Index and other cardiovascular risk factors in CMV infected and uninfected people.
Immunol. Lett.
PUBLISHED: 06-10-2014
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The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.imlet.2014.09.010. The duplicate article has therefore been withdrawn.
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Dementia diagnostic criteria in Down syndrome.
Int J Geriatr Psychiatry
PUBLISHED: 05-25-2014
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Dementia is a common clinical presentation among older adults with Down syndrome. The presentation of dementia in Down syndrome differs compared with typical Alzheimer's disease. The performance of manualised dementia criteria in the International Classification of Diseases (ICD)-10 and Diagnostic and Statistical Manual of Mental Disorders-IV-Text Revision (DSM-IV-TR) is uncertain in this population.We aimed to determine the concurrent validity and reliability of clinicians' diagnoses of dementia against ICD-10 and DSM-IV-TR diagnoses. Validity of clinical diagnoses were also explored by establishing the stability of diagnoses over time.
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A systematic review of barriers and facilitators to participation in randomized controlled trials by Indigenous people from New Zealand, Australia, Canada and the United States.
Glob Health Promot
PUBLISHED: 05-19-2014
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Many randomized controlled trials (RCTs) are conducted each year but only a small proportion is specifically designed for Indigenous people. In this review we consider the challenges of participation in RCTs for Indigenous peoples from New Zealand, Australia, Canada and the United States and the opportunities for increasing participation.
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Modeling and incorporating cardiac-induced lung tissue motion in a breathing motion model.
Med Phys
PUBLISHED: 04-04-2014
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The purpose of this work is to develop a cardiac-induced lung motion model to be integrated into an existing breathing motion model.
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Antiretroviral therapy, interferon sensitivity, and virologic setpoint in human immunodeficiency virus/hepatitis C virus coinfected patients.
Hepatology
PUBLISHED: 03-14-2014
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Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) cause substantial mortality, especially in persons chronically infected with both viruses. HIV infection raises plasma HCV RNA levels and diminishes the response to exogenous alpha interferon (IFN). The degree to which antiretroviral therapy (ART) control of infection overcomes these HIV effects is unknown. Participants with HIV-HCV coinfection were enrolled in a trial to measure HCV viral kinetics after IFN administration (?HCVIFN ) twice: initially before (pre-ART) and then after (post-ART) HIV RNA suppression. Liver tissue was obtained 2-4 hours before each IFN injection to measure interferon stimulated genes (ISGs). Following ART, the ?HCVIFN at 72 hours (?HCVIFN,72 ) increased in 15/19 (78.9%) participants by a median (interquartile range [IQR]) of 0.11 log10 IU/mL (0.00-0.40; P?
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Identification of a transcriptional signature for the wound healing continuum.
Wound Repair Regen
PUBLISHED: 02-19-2014
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There is a spectrum/continuum of adult human wound healing outcomes ranging from the enhanced (nearly scarless) healing observed in oral mucosa to scarring within skin and the nonhealing of chronic skin wounds. Central to these outcomes is the role of the fibroblast. Global gene expression profiling utilizing microarrays is starting to give insight into the role of such cells during the healing process, but no studies to date have produced a gene signature for this wound healing continuum. Microarray analysis of adult oral mucosal fibroblast (OMF), normal skin fibroblast (NF), and chronic wound fibroblast (CWF) at 0 and 6 hours post-serum stimulation was performed. Genes whose expression increases following serum exposure in the order OMF?
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Cure of hepatitis C virus infection without interferon alfa: scientific basis and current clinical evidence.
Top Antivir Med
PUBLISHED: 02-18-2014
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Cure of hepatitis C virus (HCV) infection is achievable without interferon alfa through the use of new direct-acting antiviral (DAA) drugs. In this era of interferon alfa-sparing therapy, however, interferon alfa sensitivity still matters, even as it turns out, if interferon alfa is not used. Inclusion of ribavirin in the treatment regimen remains a factor in treatment response, as does duration of treatment. HCV genotype and subtype remain relevant considerations in choosing a treatment regimen, and viral resistance may emerge when treatment fails. The potency and barrier to resistance of new DAAs and the use of appropriately designed interferon alfa-sparing combinations can overcome obstacles to cure posed by HCV resistance, interferon alfa resistance, and differences in response based on HCV genotype and subtype. Studies demonstrating the use of new DAAs to overcome these obstacles are discussed. This article summarizes a presentation by David L. Thomas, MD, MPH, at the IAS-USA continuing education program held in New York, New York, in June 2013.
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Comparison of ASL and DCE MRI for the non-invasive measurement of renal blood flow: quantification and reproducibility.
Eur Radiol
PUBLISHED: 02-13-2014
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To investigate the reproducibility of arterial spin labelling (ASL) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and quantitatively compare these techniques for the measurement of renal blood flow (RBF).
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Evaluation of segmented 3D acquisition schemes for whole-brain high-resolution arterial spin labeling at 3?T.
NMR Biomed
PUBLISHED: 02-06-2014
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Recent technical developments have significantly increased the signal-to-noise ratio (SNR) of arterial spin labeled (ASL) perfusion MRI. Despite this, typical ASL acquisitions still employ large voxel sizes. The purpose of this work was to implement and evaluate two ASL sequences optimized for whole-brain high-resolution perfusion imaging, combining pseudo-continuous ASL (pCASL), background suppression (BS) and 3D segmented readouts, with different in-plane k-space trajectories. Identical labeling and BS pulses were implemented for both sequences. Two segmented 3D readout schemes with different in-plane trajectories were compared: Cartesian (3D GRASE) and spiral (3D RARE Stack-Of-Spirals). High-resolution perfusion images (2?×?2?×?4?mm(3) ) were acquired in 15 young healthy volunteers with the two ASL sequences at 3?T. The quality of the perfusion maps was evaluated in terms of SNR and gray-to-white matter contrast. Point-spread-function simulations were carried out to assess the impact of readout differences on the effective resolution. The combination of pCASL, in-plane segmented 3D readouts and BS provided high-SNR high-resolution ASL perfusion images of the whole brain. Although both sequences produced excellent image quality, the 3D RARE Stack-Of-Spirals readout yielded higher temporal and spatial SNR than 3D GRASE (spatial SNR?=?8.5?±?2.8 and 3.7?±?1.4; temporal SNR?=?27.4?±?12.5 and 15.6?±?7.6, respectively) and decreased through-plane blurring due to its inherent oversampling of the central k-space region, its reduced effective TE and shorter total readout time, at the expense of a slight increase in the effective in-plane voxel size. Copyright © 2014 John Wiley & Sons, Ltd.
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Fibrosis progression in human immunodeficiency virus/hepatitis C virus coinfected adults: prospective analysis of 435 liver biopsy pairs.
Hepatology
PUBLISHED: 01-16-2014
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Human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection is associated with progressive liver disease. However, the rate of progression is variable and the ability to differentiate patients with stable versus progressive HCV disease is limited. The objective of this study was to assess the incidence of and risk factors for fibrosis progression in a prospective cohort of coinfected patients. Overall, 435 liver biopsy pairs from 282 patients without cirrhosis were analyzed. Biopsies were scored according to the METAVIR system by a single pathologist blind to biopsy sequence. Fibrosis progression was defined as an increase of at least one METAVIR fibrosis stage between paired biopsies. The majority of patients were African American (84.8%), male (67.7%), and infected with HCV genotype 1 (93.4%). On initial biopsy, no or minimal fibrosis was identified in 243 patients (86%). The median interval between biopsies was 2.5 years. Fibrosis progression was observed in 97 of 282 (34%) patients and 149 of 435 (34%) biopsy pairs. After adjustment, greater body mass index (adjusted odds ratio [aOR]: 1.04 per 1 unit increase), diabetes (aOR: 1.56), and hepatic steatosis (aOR: 1.78) at the time of initial biopsy were marginally associated with subsequent fibrosis progression. Between biopsies, elevated serum aspartate and alanine aminotransferase (AST, ALT) (aOR AST: 3.34, ALT: 2.18 for >25% values >100 U/L versus <25% values >100 U/L) were strongly associated with fibrosis progression.
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Memory in multiple sclerosis is linked to glutamate concentration in grey matter regions.
J. Neurol. Neurosurg. Psychiatr.
PUBLISHED: 01-15-2014
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Glutamate is the principal excitatory neurotransmitter and is involved in normal brain function. Cognitive impairment is common in multiple sclerosis (MS), and understanding its mechanisms is crucial for developing effective treatments. We used structural and metabolic brain imaging to test two hypotheses: (i) glutamate levels in grey matter regions are abnormal in MS, and (ii) patients show a relationship between glutamate concentration and memory performance.
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A novel fast helical 4D-CT acquisition technique to generate low-noise sorting artifact-free images at user-selected breathing phases.
Int. J. Radiat. Oncol. Biol. Phys.
PUBLISHED: 01-13-2014
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To develop a novel 4-dimensional computed tomography (4D-CT) technique that exploits standard fast helical acquisition, a simultaneous breathing surrogate measurement, deformable image registration, and a breathing motion model to remove sorting artifacts.
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Alginate Oligosaccharides Inhibit Fungal Cell Growth and Potentiate the Activity of Antifungals against Candida and Aspergillus spp.
PLoS ONE
PUBLISHED: 01-01-2014
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The oligosaccharide OligoG, an alginate derived from seaweed, has been shown to have anti-bacterial and anti-biofilm properties and potentiates the activity of selected antibiotics against multi-drug resistant bacteria. The ability of OligoG to perturb fungal growth and potentiate conventional antifungal agents was evaluated using a range of pathogenic fungal strains. Candida (n?=?11) and Aspergillus (n?=?3) spp. were tested using germ tube assays, LIVE/DEAD staining, scanning electron microscopy (SEM), atomic force microscopy (AFM) and high-throughput minimum inhibition concentration assays (MICs). In general, the strains tested showed a significant dose-dependent reduction in cell growth at ?6% OligoG as measured by optical density (OD600; P<0.05). OligoG (>0.5%) also showed a significant inhibitory effect on hyphal growth in germ tube assays, although strain-dependent variations in efficacy were observed (P<0.05). SEM and AFM both showed that OligoG (?2%) markedly disrupted fungal biofilm formation, both alone, and in combination with fluconazole. Cell surface roughness was also significantly increased by the combination treatment (P<0.001). High-throughput robotic MIC screening demonstrated the potentiating effects of OligoG (2, 6, 10%) with nystatin, amphotericin B, fluconazole, miconazole, voriconazole or terbinafine with the test strains. Potentiating effects were observed for the Aspergillus strains with all six antifungal agents, with an up to 16-fold (nystatin) reduction in MIC. Similarly, all the Candida spp. showed potentiation with nystatin (up to 16-fold) and fluconazole (up to 8-fold). These findings demonstrate the antifungal properties of OligoG and suggest a potential role in the management of fungal infections and possible reduction of antifungal toxicity.
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Faecal Microbiota of Forage-Fed Horses in New Zealand and the Population Dynamics of Microbial Communities following Dietary Change.
PLoS ONE
PUBLISHED: 01-01-2014
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The effects of abrupt dietary transition on the faecal microbiota of forage-fed horses over a 3-week period were investigated. Yearling Thoroughbred fillies reared as a cohort were exclusively fed on either an ensiled conserved forage-grain diet ("Group A"; n?=?6) or pasture ("Group B"; n?=?6) for three weeks prior to the study. After the Day 0 faecal samples were collected, horses of Group A were abruptly transitioned to pasture. Both groups continued to graze similar pasture for three weeks, with faecal samples collected at 4-day intervals. DNA was isolated from the faeces and microbial 16S and 18S rRNA gene amplicons were generated and analysed by pyrosequencing. The faecal bacterial communities of both groups of horses were highly diverse (Simpson's index of diversity >0.8), with differences between the two groups on Day 0 (P<0.017 adjusted for multiple comparisons). There were differences between Groups A and B in the relative abundances of four genera, BF311 (family Bacteroidaceae; P?=?0.003), CF231 (family Paraprevotellaceae; P?=?0.004), and currently unclassified members within the order Clostridiales (P?=?0.003) and within the family Lachnospiraceae (P?=?0.006). The bacterial community of Group A horses became similar to Group B within four days of feeding on pasture, whereas the structure of the archaeal community remained constant pre- and post-dietary change. The community structure of the faecal microbiota (bacteria, archaea and ciliate protozoa) of pasture-fed horses was also identified. The initial differences observed appeared to be linked to recent dietary history, with the bacterial community of the forage-fed horses responding rapidly to abrupt dietary change.
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Energy requirements of adult dogs: a meta-analysis.
PLoS ONE
PUBLISHED: 01-01-2014
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A meta-analysis was conducted to determine the maintenance energy requirements of adult dogs. Suitable publications were first identified, and then used to generate relationships amongst energy requirements, husbandry, activity level, methodology, sex, neuter status, dog size, and age in healthy adult dogs. Allometric equations for maintenance energy requirements were determined using log-log linear regression. So that the resulting equations could readily be compared with equations reported by the National Research Council, maintenance energy requirements in the current study were determined in kcal/kg0.75 body weight (BW). Ultimately, the data of 70 treatment groups from 29 publications were used, and mean (± standard deviation) maintenance energy requirements were 142.8±55.3 kcal.kgBW-0.75.day-1. The corresponding allometric equation was 81.5 kcal.kgBW-0.93.day-1 (adjusted R2?=?0.64; 70 treatment groups). Type of husbandry had a significant effect on maintenance energy requirements (P<0.001): requirements were greatest in racing dogs, followed by working dogs and hunting dogs, whilst the energy requirements of pet dogs and kennel dogs were least. Maintenance energy requirements were less in neutered compared with sexually intact dogs (P<0.001), but there was no effect of sex. Further, reported activity level tended to effect the maintenance energy requirement of the dog (P?=?0.09). This review suggests that estimating maintenance energy requirements based on BW alone may not be accurate, but that predictions that factor in husbandry, neuter status and, possibly, activity level might be superior. Additionally, more information on the nutrient requirements of older dogs, and those at the extremes of body size (i.e. giant and toy breeds) is needed.
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Dairy sheep production research at the University of Wisconsin-Madison, USA - a review.
J Anim Sci Biotechnol
PUBLISHED: 01-01-2014
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Commercial milking of sheep is a new agricultural industry in the United States starting approximately 30 yr ago. The industry is still small, but it is growing. The majority of the sheep milk is used in the production of specialty cheeses. The United States is the major importer of sheep milk cheeses with 50 to 60% of annual world exports coming to the United States during the past 20 yr. Therefore, there is considerable growth potential for the industry in the United States. The only dairy sheep research flock in North America is located at the Spooner Agricultural Research Station of the University of Wisconsin-Madison. The research program started in 1993 and has been multifaceted; dealing with several areas important to commercial dairy sheep farmers. The East Friesian and Lacaune dairy breeds were compared and introduced to the industry through the research program. Both dairy breeds produced significantly more milk than traditional meat-wool breeds found in the U.S., but the two breeds differed in their production traits. East Friesian-cross ewes produced more lambs and slightly more milk than Lacaune-cross ewes whereas Lacaune-cross ewes produced milk with a higher percentage of fat and protein than East Friesian-cross ewes. Lactation physiology studies have shown that ewes with active corpora lutea have increased milk yields, oxytocin release during milking is required to obtain normal fat percentages in the milk, large udder cisterns of dairy ewes can allow for increased milking intervals, and short daylengths during late pregnancy results in increased milk yield. In the nutrition area, legume-grass pastures and forages with a higher percentage of legume will result in increased milk production. Grazing ewes respond to additional supplementation with increased milk yield, but it is important to match the supplement to the quality of the grazing. Ewes on high quality legume-grass pastures that are high in rumen degradable protein respond with increased milk production to supplements high in energy and/or high in rumen undegraded protein.
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A Novel Cytomegalovirus-Induced Regulatory-Type T-Cell Subset Increases in Size During Older Life and Links Virus-Specific Immunity to Vascular Pathology.
J. Infect. Dis.
PUBLISHED: 11-07-2013
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Background.?Cytomegalovirus (CMV) infection directly targets vascular endothelium and smooth muscle and at older ages is associated with accelerated vascular pathology and mortality. CMV-specific cellular immunity might directly contribute to this process.Methods.?Conventional ex vivo activation-induced T-cell responses to 19 dominant CMV antigens, along with CMV-specific inducible regulatory-type CD4(+) T cells (iTregs), were measured in healthy older people, using a novel protocol that included classic Treg markers alongside the activation marker CD134. Measurements were correlated with diastolic, systolic, and mean arterial blood pressure, a surrogate marker for arterial stiffness.Results.?CMV-specific iTregs recognized the same antigens as conventional CD4(+) T cells and were significantly more frequent at older ages. They suppressed antigen-specific and nonspecific proliferation and in large part expressed Foxp3. Frequencies of CMV-specific iTregs and CD8(+) T cells (summated response) were significantly associated with diastolic and mean arterial pressures. Confounders, including age, body mass index, smoking, antihypertensive medication use, or C-reactive protein levels, did not explain these observations.Conclusions.?A novel CMV-induced regulatory-type CD4(+) T-cell subset is readily detectable in CMV-infected people and, like the aggregate CD8(+) T-cell response to the most dominant CMV antigens, is quantitatively associated with arterial stiffness in older life. Whereas CD8(+) effector T cells might directly cause vascular injury, iTregs may attenuate this response.
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Management of sarcoma in the Asia-Pacific region: resource-stratified guidelines.
Lancet Oncol.
PUBLISHED: 11-02-2013
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Sarcomas are a rare and diverse set of cancers that disproportionately affect young people. The best possible outcome depends on access to highly specialised, multidisciplinary care. Although advances have been made in therapeutic techniques, access to some treatments might be limited by cost implications. This Review proposes an evidence-based, consensus recommendation for optimum management of bone and soft-tissue sarcoma across the Asia-Pacific region, taking into account variation in health-care resources, stratified according to the Breast Health Global Initiative resource levels. A web-based survey of 89 clinicians involved in the care of patients with sarcoma from 18 Asia-Pacific countries generated the recommendations for diagnosis, staging, and management, including supportive and palliative care, and research.
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Cytomegalovirus infection modulates the phenotype and functional profile of the T-cell immune response to mycobacterial antigens in older life.
Exp. Gerontol.
PUBLISHED: 10-29-2013
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Infection with Cytomegalovirus is associated with accelerated immunosenescence. Expansions of CMV-specific T cell responses have previously been demonstrated to affect the ability of T cells to respond to other infections. Most people above 60years of age display M. tuberculosis-specific immunity because of vaccination, exposure, or both. T-cell responses can be assessed by measuring intracellular IFN-? in vitro after tuberculin stimulation. Here we investigated tuberculin-specific CD4 T-cell responses in independently living healthy older people in the South of England using flow-cytometry. Individuals were investigated for tuberculin and CMV-specific T-cell immunity using in vitro antigen stimulation followed by intracellular staining for IFN-?, TNF-?, IL2, as well as degranulation and CD154 upregulation. We also examined a control group of younger individuals (20-35years of age). There was no significant difference between older and young people in regards to tuberculin responsiveness of CD4 T-cells; however, older people seemed to show more outliers. Increased responsiveness to tuberculin was significantly correlated to CMV responsiveness but not age. In older donors, the memory phenotype of tuberculin-induced T-cells was significantly skewed towards a more terminal differentiation phenotype in CMV-infected compared to uninfected individuals and the degree of skewing correlated quantitatively with the size of the CMV-specific CD4 T-cell response. This is a fundamental advance over previous reports of changes of the tuberculin-specific CD4 T-cell response with CMV serostatus. Our results show that how the immune system responds to CMV has a fundamental impact on the phenotype and function of the immune response to mycobacterial antigens in older life.
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High frequency of false-positive hepatitis C virus enzyme-linked immunosorbent assay in rakai, Uganda.
Clin. Infect. Dis.
PUBLISHED: 09-18-2013
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The prevalence of hepatitis C virus (HCV) infection in sub-Saharan Africa remains unclear. We tested 1000 individuals from Rakai, Uganda, with the Ortho version 3.0 HCV enzyme-linked immunosorbent assay. All serologically positive samples were tested for HCV RNA. Seventy-six of the 1000 (7.6%) participants were HCV antibody positive; none were confirmed by detection of HCV RNA.
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Variants in HAVCR1 Gene Region Contribute to Hepatitis C Persistence in African Americans.
J. Infect. Dis.
PUBLISHED: 08-20-2013
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To confirm previously identified polymorphisms in HAVCR1 that were associated with persistent hepatitis C virus (HCV) infection in individuals of African and of European descent, we studied 165 subjects of African descent and 635 subjects of European descent. Because the association was only confirmed in subjects of African descent (rs6880859; odds ratio, 2.42; P = .01), we then used 379 subjects of African descent (142 with spontaneous HCV clearance) to fine-map HAVCR1. rs111511318 was strongly associated with HCV persistence after adjusting for IL28B and HLA (adjusted P = 8.8 × 10(-4)), as was one 81-kb haplotype (adjusted P = .0006). The HAVCR1 genomic region is an independent genetic determinant of HCV persistence in individuals of African descent.
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Association of the IFNL4-?G Allele With Impaired Spontaneous Clearance of Hepatitis C Virus.
J. Infect. Dis.
PUBLISHED: 08-15-2013
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Interferon lambda 4 protein can be generated in IFNL4-?G carriers but not IFNL4-TT homozygotes. We studied 890 anti-hepatitis C virus (HCV)-positive participants in the Womens Interagency HIV Study. Among blacks (n = 555), HCV was more often cleared for those with genotype IFNL4-TT/TT (32.6%; odds ratio [OR], 3.59; P = 3.3 × 10(-5)) than IFNL4-TT/?G (11.3%; OR, 0.95; P = .86) or IFNL4-?G/?G (11.9%; referent). Pooling these data with published results in blacks (n = 1678), ORs were 3.84 (P = 8.6 × 10(-14)) for IFNL4-TT/TT and 1.44 (P = .03) IFNL4-TT/?G, and the area under the curve was 0.64 for IFNL4-?G genotype and 0.61 for rs12979860 (IL28B). IFNL4-?G is strongly associated with impaired spontaneous HCV clearance.
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E-health systems for management of MDR-TB in resource-poor environments: a decade of experience and recommendations for future work.
Stud Health Technol Inform
PUBLISHED: 08-08-2013
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Multi-drug resistant TB (MDR-TB) is a complex infectious disease that is a growing threat to global health. It requires lengthy treatment with multiple drugs and specialized laboratory testing. To effectively scale up treatment to thousands of patients requires good information systems to support clinical care, reporting, drug forecasting, supply chain management and monitoring.
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Massively-parallel sequencing assists the diagnosis and guided treatment of cancers of unknown primary.
J. Pathol.
PUBLISHED: 07-30-2013
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The clinical management of patients with cancer of unknown primary (CUP) is hampered by the absence of a definitive site of origin. We explored the utility of massively-parallel (next-generation) sequencing for the diagnosis of a primary site of origin and for the identification of novel treatment options. DNA enrichment by hybridisation capture of 701 genes of clinical and/or biological importance, followed by massively-parallel sequencing, was performed on 16 CUP patients who had defied attempts to identify a likely site of origin. We obtained high quality data from both fresh-frozen and formalin-fixed paraffin-embedded samples, demonstrating accessibility to routine diagnostic material. DNA copy number obtained by massively-parallel sequencing was comparable to that obtained using oligonucleotide microarrays or quantitatively hybridized fluorescently tagged oligonucleotides. Sequencing to an average depth of 458-fold enabled detection of somatically acquired single nucleotide mutations, insertions, deletions and copy number changes, and measurement of allelic frequency. Common cancer causing mutations were found in all cancers. Mutation profiling revealed therapeutic gene targets and pathways in 12/16 cases, providing novel treatment options. The presence of driver mutations that are enriched in certain known tumour types, together with mutational signatures indicative of exposure to sunlight or smoking, added to clinical, pathological, and molecular indicators of likely tissue of origin. Massively-parallel DNA sequencing can therefore provide comprehensive mutation, DNA copy number and mutational signature data that is of significant clinical value for a majority of CUP patients, providing both cumulative evidence for the diagnosis of primary site and options for future treatment.
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Hepatitis C virus vaccines among people who inject drugs.
Clin. Infect. Dis.
PUBLISHED: 07-26-2013
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Most people who inject drugs (PWID) are infected with hepatitis C virus (HCV), and PWID have the highest risk of HCV infection of any risk group. The incidence of HCV infection is 5%-25% per year, demonstrating continued need for HCV infection prevention in PWID. Existing data in chimpanzees and PWID suggest that protective immunity against persistent HCV infection is achievable. Due to the high incidence of infection, PWID are both the most likely to benefit from a vaccine and a population in which vaccine efficacy could be tested. Challenges to testing a vaccine in PWID are significant. However, the first HCV vaccine trial in at-risk HCV-uninfected PWID was initiated in 2012. The results will likely guide future vaccine development and strategies for vaccination of this and other high-risk populations.
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Hepatitis C Virus Infection Is Not An Independent Risk Factor For Obstructive Lung Disease.
COPD
PUBLISHED: 07-17-2013
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Abstract Several epidemiological studies have suggested that hepatitis C virus (HCV) infection is associated with the presence of obstructive lung disease (OLD). However, there is a strong link between HCV infection and tobacco abuse, a major risk factor for the development of OLD. In this study we analyzed clinical, laboratory and spirometric data from 1068 study participants to assess whether HCV infection, viremia, or HCV-associated end organ damage were associated with OLD. Demographics, risk behavior, serologic status for HCV and HIV, and spirometric measurements were collected from a cross-sectional analysis of the Acquired Immunodeficiency Syndrome (AIDS) Linked to the IntraVenous Experience (ALIVE) study, an observational cohort of IDUs followed in Baltimore, MD since 1988. Of 1,068 participants, 890 (83%) were HCV positive and 174 (16%) met spirometric criteria for OLD. Factors independently associated with OLD were age and BMI. HCV infection, viral load and HCV-associated end organ damage were similar in participants with and without OLD. In summary, there was no independent association between markers of HCV exposure, chronicity, viremia, or HCV-associated end-organ damage with OLD. Our findings support the strong correlation between HCV status, injection drug use, and smoking. These data suggest that HCV may not be a sole contributor to the increased prevalence of OLD described in previous studies of HCV-infected individuals.
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Safety and efficacy of denosumab for adults and skeletally mature adolescents with giant cell tumour of bone: interim analysis of an open-label, parallel-group, phase 2 study.
Lancet Oncol.
PUBLISHED: 07-16-2013
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Giant cell tumour of bone (GCTB) is a very rare, aggressive, and progressive osteolytic tumour for which no standard medicinal treatment or chemotherapy exists. We report interim safety and efficacy results from a phase 2 study of denosumab in patients with GCTB.
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Modelling blood flow and metabolism in the piglet brain during hypoxia-ischaemia: simulating brain energetics.
Adv. Exp. Med. Biol.
PUBLISHED: 07-16-2013
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We have developed a computational model to simulate hypoxia-ischaemia (HI) in the neonatal piglet brain. It has been extended from a previous model by adding the simulation of carotid artery occlusion and including pH changes in the cytoplasm. Here, simulations from the model are compared with near-infrared spectroscopy (NIRS) and phosphorus magnetic resonance spectroscopy (MRS) measurements from two piglets during HI and short-term recovery. One of these piglets showed incomplete recovery after HI, and this is modelled by considering some of the cells to be dead. This is consistent with the results from MRS and the redox state of cytochrome-c-oxidase as measured by NIRS. However, the simulations do not match the NIRS haemoglobin measurements. The model therefore predicts that further physiological changes must also be taking place if the hypothesis of dead cells is correct.
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Modelling blood flow and metabolism in the piglet brain during hypoxia-ischaemia: simulating pH changes.
Adv. Exp. Med. Biol.
PUBLISHED: 07-16-2013
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We describe the extension of a computational model of blood flow and metabolism in the piglet brain to investigate changes in neonatal intracellular brain pH during hypoxia-ischemia (HI). The model is able to simulate near-infrared spectroscopy (NIRS) and magnetic resonance spectroscopy (MRS) measurements obtained from HI experiments conducted in piglets. We adopt a method of using (31)P-MRS data to estimate of intracellular pH and compare measured pH and oxygenation with their modelled counterparts. We show that both NIRS and MRS measurements are predicted well in the new version of the model.
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In vivo imaging of glucose uptake and metabolism in tumors.
Nat. Med.
PUBLISHED: 07-07-2013
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Tumors have a greater reliance on anaerobic glycolysis for energy production than normal tissues. We developed a noninvasive method for imaging glucose uptake in vivo that is based on magnetic resonance imaging and allows the uptake of unlabeled glucose to be measured through the chemical exchange of protons between hydroxyl groups and water. This method differs from existing molecular imaging methods because it permits detection of the delivery and uptake of a metabolically active compound in physiological quantities. We show that our technique, named glucose chemical exchange saturation transfer (glucoCEST), is sensitive to tumor glucose accumulation in colorectal tumor models and can distinguish tumor types with differing metabolic characteristics and pathophysiologies. The results of this study suggest that glucoCEST has potential as a useful and cost-effective method for characterizing disease and assessing response to therapy in the clinic.
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Human immunodeficiency virus and liver disease forum 2012.
Hepatology
PUBLISHED: 05-02-2013
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In the United States, more than 1.1 million individuals are infected with the human immunodeficiency virus (HIV). These patients exhibit a high frequency of coinfections with other hepatotropic viruses and ongoing fibrosis, leading to cirrhosis and liver-related mortality. Etiologies of liver disease include viral hepatitis coinfections, drug-related hepatotoxicity, fatty liver disease, and direct and indirect effects from HIV infection, including increased bacterial translocation, immune activation, and presence of soluble proteins, that modulate the hepatic cytokine environment. New treatments for hepatitis C virus (HCV) using direct-acting agents appear viable, though issues related to intrinsic toxicities and drug-drug interactions remain. Recent research suggests that acute HCV infection, unrecognized hepatitis D infection, and hepatitis E may all represent emergent areas of concern. Antiretroviral agents, including those used in recent years, may represent risk factors for hepatic injury and portal hypertension. Key issues in the future include systematic implementation of liver disease management and new treatment in HIV-infected populations with concomitant injection drug use, alcohol use, and low socioeconomic status. (Hepatology 2014;58:307-317).
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Identification of small molecules for human hepatocyte expansion and iPS differentiation.
Nat. Chem. Biol.
PUBLISHED: 05-01-2013
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Cell-based therapies hold the potential to alleviate the growing burden of liver diseases. Such therapies require human hepatocytes, which, within the stromal context of the liver, are capable of many rounds of replication. However, this ability is lost ex vivo, and human hepatocyte sourcing has limited many fields of research for decades. Here we developed a high-throughput screening platform for primary human hepatocytes to identify small molecules in two different classes that can be used to generate renewable sources of functional human hepatocytes. The first class induced functional proliferation of primary human hepatocytes in vitro. The second class enhanced hepatocyte functions and promoted the differentiation of induced pluripotent stem cell-derived hepatocytes toward a more mature phenotype than what was previously obtainable. The identification of these small molecules can help address a major challenge affecting many facets of liver research and may lead to the development of new therapeutics for liver diseases.
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The effect of alginate oligosaccharides on the mechanical properties of Gram-negative biofilms.
Biofouling
PUBLISHED: 04-12-2013
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The influence of a novel, safe antibiofilm therapy on the mechanical properties of Pseudomonas aeruginosa and Acinetobacter baumannii biofilms in vitro was characterized. A multiscale approach employing atomic force microscopy (AFM) and rheometry was used to quantify the mechanical disruption of the biofilms by a therapeutic polymer based on a low-molecular weight alginate oligosaccharide (OligoG). AFM demonstrated structural alterations in the biofilms exposed to OligoG, with significantly lower Youngs moduli than the untreated biofilms, (149 MPa vs 242 MPa; p < 0.05), a decreased resistance to hydrodynamic shear and an increased surface irregularity (Ra) in the untreated controls (35.2 nm ± 7.6 vs 12.1 nm ± 5.4; p < 0.05). Rheology demonstrated that increasing clinically relevant concentrations of OligoG (<10%) were associated with an increasing phase angle (?) over a wide range of frequencies (0.1-10 Hz). These results highlight the utility of these techniques for the study of three-dimensional biofilms and for quantifying novel disruption therapies in vitro.
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Global control of hepatitis C: where challenge meets opportunity.
Nat. Med.
PUBLISHED: 04-05-2013
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We are entering an important new chapter in the story of hepatitis C virus (HCV) infection. There are clear challenges and opportunities. On the one hand, new HCV infections are still occurring, and an estimated 185 million people are or have previously been infected worldwide. Most HCV-infected persons are unaware of their status yet are at risk for life-threatening diseases such as cirrhosis and hepatocellular carcinoma (HCC), whose incidences are predicted to rise in the coming decade. On the other hand, new HCV infections can be prevented, and those that have already occurred can be detected and treated--viral eradication is even possible. How the story ends will largely be determined by the extent to which these rapidly advancing opportunities overcome the growing challenges and by the vigor of the public health response.
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Comparison of inferred fractions of n-3 and n-6 polyunsaturated fatty acids in feral domestic cat diets with those in commercial feline extruded diets.
Am. J. Vet. Res.
PUBLISHED: 03-28-2013
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To compare presumed fatty acid content in natural diets of feral domestic cats (inferred from body fat polyunsatrated fatty acids content) with polyunsaturated fatty acid content of commercial feline extruded diets.
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Direct-Acting Antiviral Agents and the Path to Interferon Independence.
Clin. Gastroenterol. Hepatol.
PUBLISHED: 03-27-2013
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Chronic infection with hepatitis C virus (HCV) is a major global health problem; there are approximately 120 to 130 million chronic infections worldwide. Since the discovery of HCV 24 years ago, there has been a relentless effort to develop successful antiviral therapies. Studies of interferon-?-based therapies have helped define treatment parameters, and these treatment strategies have cured a substantial percentage of patients. However, interferon-? must be injected; there are problems with tolerability, adherence, and incomplete response in a large percentage of patients. New drug candidates designed to target the virus or the host have recently been introduced at an unprecedented pace. In phase I-III studies, these agents have exceeded expectations and achieved rates of response previously not thought possible. We are, therefore, entering a new era of therapy for HCV infection and interferon independence.
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Low Myo-inositol indicating astrocytic damage in a case series of neuromyelitis optica.
Ann. Neurol.
PUBLISHED: 03-22-2013
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Astrocytic necrosis is a prominent pathological feature of neuromyelitis optica (NMO) lesions and is clinically relevant. We report 5 NMO-related cases, all with longitudinally extensive lesions in the upper cervical cord, who underwent cervical cord (1) H-magnetic resonance spectroscopy. Lower myo-inositol/creatine values, suggesting astrocytic damage, were consistently found within the NMO lesions when compared with healthy controls and patients with multiple sclerosis (MS), who showed at least 1 demyelinating lesion at the same cord level. Therefore, the in vivo quantification of myo-inositol may distinguish NMO from MS. This is an important step toward developing imaging markers for clinical trials in NMO. Ann Neurol 2013.
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Contrasting host immuno-inflammatory responses to bacterial challenge within venous and diabetic ulcers.
Wound Repair Regen
PUBLISHED: 03-18-2013
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Within chronic wounds, the relationship between the clinical diagnosis of infection and bacterial/immuno-inflammatory responses is imprecise. This study prospectively examined the interrelationship between clinical, microbiological, and proinflammatory biomarker levels between chronic venous leg ulcers (CVLUs) and diabetic foot ulcers (DFUs). Wound swabs and fluids were collected from CVLUs (n?=?18) and DFUs (n?=?15) and diagnosed clinically as noninfected or infected; and qualitative/quantitative microbiology was performed. CVLU and DFU fluids were also analyzed for cytokine, growth factor, receptor, proteinase/proteinase inhibitor; and oxidative stress biomarker (protein carbonyl, malondialdehyde, and antioxidant capacity) levels. While no correlations existed between clinical diagnosis, microbiology, or biomarker profiles, increasing bacterial bioburden (?10(7) colony-forming unit/mL) was associated with significant alterations in cytokine, growth factor, and receptor levels. These responses contrasted between ulcer type, with elevated and decreased cytokine, growth factor, and receptor levels in CVLUs and DFUs with increasing bioburden, respectively. Despite proteinase biomarkers exhibiting few differences between CVLUs and DFUs, significant elevations in antioxidant capacities correlated with increased bioburden in CVLU fluids, but not in DFUs. Furthermore, oxidative stress biomarker levels were significantly elevated in all DFU fluids compared with CVLUs. This study provides further insight into the contrasting disease-specific host responses to bacterial challenge within infected CVLUs and DFUs.
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HIV, age, and the severity of hepatitis C virus-related liver disease: a cohort study.
Ann. Intern. Med.
PUBLISHED: 02-27-2013
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Persons with HIV infection have been reported to develop age-related diseases at younger ages than those without HIV. Whether this finding is related to HIV infection or failure to control for other risk factors is unknown.
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Diffusion tensor parameters and principal eigenvector coherence: relation to b-value intervals and field strength.
Magn Reson Imaging
PUBLISHED: 01-30-2013
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Diffusion-weighted MRI images acquired at b-value greater than 1000 s mm(-2) measure the diffusion of a restricted pool of water molecules. High b-value images are accompanied by a reduction in signal-to-noise ratio (SNR) due to the application of large diffusion gradients. By fitting the diffusion tensor model to data acquired at incremental b-value intervals, we determined the effect of SNR on tensor parameters in normal human brains, in vivo. In addition, we also investigated the impact of field strength on the diffusion tensor model. Data were acquired at 1.5 and 3T, at b-values 0, 1000, 2000 and 3000 s mm(-2) in twenty diffusion-sensitised directions. Fractional anisotropy (FA), mean diffusivity (MD) and principal eigenvector coherence (?) were calculated from diffusion tensors fitted between datasets with b-values 0-1000, 0-2000, 0-3000, 1000-2000 and 2000-3000 s mm(-2). Field strength and b-value effects on diffusion parameters were analysed in white and grey matter regions of interest. Decreases in FA, ? and MD were found with increasing b-value in white matter. Univariate analysis showed a significant increase in FA with increasing field strength in highly organised white matter. These results suggest there are significant differences in diffusion parameters at 1.5 and 3T and that the optimal results, in terms of the highest values of FA in white matter, are obtained at 3T with a maximum b=1000 s mm(-2).
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Chemical Genetics of Rapamycin-Insensitive TORC2 in S. cerevisiae.
Cell Rep
PUBLISHED: 01-24-2013
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Current approaches for identifying synergistic targets use cell culture models to see if the combined effect of clinically available drugs is better than predicted by their individual efficacy. New techniques are needed to systematically and rationally identify targets and pathways that may be synergistic targets. Here, we created a tool to screen and identify molecular targets that may synergize with new inhibitors of target of rapamycin (TOR), a conserved protein that is a major integrator of cell proliferation signals in the nutrient-signaling pathway. Although clinical results from TOR complex 1 (TORC1)-specific inhibition using rapamycin analogs have been disappointing, trials using inhibitors that also target TORC2 have been promising. To understand this increased therapeutic efficacy and to discover secondary targets for combination therapy, we engineered Tor2 in S. cerevisiae to accept an orthogonal inhibitor. We used this tool to create a chemical epistasis miniarray profile (ChE-MAP) by measuring interactions between the chemically inhibited Tor2 kinase and a diverse library of deletion mutants. The ChE-MAP identified known TOR components and distinguished between TORC1- and TORC2-dependent functions. The results showed a TORC2-specific interaction with the pentose phosphate pathway, a previously unappreciated TORC2 function that suggests a role for the complex in balancing the high energy demand required for ribosome biogenesis.
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A microscale human liver platform that supports the hepatic stages of Plasmodium falciparum and vivax.
Cell Host Microbe
PUBLISHED: 01-15-2013
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The Plasmodium liver stage is an attractive target for the development of antimalarial drugs and vaccines, as it provides an opportunity to interrupt the life cycle of the parasite at a critical early stage. However, targeting the liver stage has been difficult. Undoubtedly, a major barrier has been the lack of robust, reliable, and reproducible in vitro liver-stage cultures. Here, we establish the liver stages for both Plasmodium falciparum and Plasmodium vivax in a microscale human liver platform composed of cryopreserved, micropatterned human primary hepatocytes surrounded by supportive stromal cells. Using this system, we have successfully recapitulated the full liver stage of P. falciparum, including the release of infected merozoites and infection of overlaid erythrocytes, as well as the establishment of small forms in late liver stages of P. vivax. Finally, we validate the potential of this platform as a tool for medium-throughput antimalarial drug screening and vaccine development.
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Orthogonalizing crusher and diffusion-encoding gradients to suppress undesired echo pathways in the twice-refocused spin echo diffusion sequence.
Magn Reson Med
PUBLISHED: 01-10-2013
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PURPOSE: The twice-refocused spin echo sequence is widely used in diffusion imaging due to its excellent performance in reducing eddy currents. The three radio frequency pulses give rise to eight separate signal pathways. Because there is no general solution for the size and arrangement for crusher gradients, with constant size and orientation, that is effective for all arbitrary diffusion-sensitizing b-values and directions, this article introduces and validates a solution whereby the crusher and diffusion-encoding gradients are always kept orthogonal, thus ensuring their independence. METHODS: The cancellation of the crusher and diffusion gradients was demonstrated. Subsequently, crusher gradients were implemented in such a way that they were always orthogonal to the diffusion gradient. Phantom and in-vivo experiments were performed to ascertain that orthogonally implemented crusher gradients alleviate the problem without lowering image quality. RESULTS: In all experiments, when the crusher gradients action was cancelled by the diffusion-encoding gradients artifactual signal modulation was observed. When orthogonal gradients were implemented the artifacts were eliminated without detrimental effects on image quality. CONCLUSIONS: Orthogonal crushers are easy to implement and can be used for any variant of diffusion imaging sequences (e.g., DTI, fiber diameter mapping) where the twice-refocused scheme is used. Magn Reson Med, 2013. © 2013 Wiley Periodicals, Inc.
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Dietary format alters fecal bacterial populations in the domestic cat (Felis catus).
Microbiologyopen
PUBLISHED: 01-07-2013
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The effects of short-term (5-week) exposure to wet or dry diets on fecal bacterial populations in the cat were investigated. Sixteen mixed-sex, neutered, domestic short-haired cats (mean age = 6 years; mean bodyweight = 3.4 kg) were randomly allocated to wet or dry diets in a crossover design. Fecal bacterial DNA was isolated and bacterial 16S rRNA gene amplicons generated and analyzed by 454 Titanium pyrosequencing. Cats fed dry diets had higher abundances (P < 0.05) of Actinobacteria (16.5% vs. 0.1%) and lower abundances of Fusobacteria (0.3% vs. 23.1%) and Proteobacteria (0.4% vs. 1.1%) compared with cats fed the wet diet. Of the 46 genera identified, 30 were affected (P < 0.05) by diet, with higher abundances of Lactobacillus (31.8% vs. 0.1%), Megasphaera (23.0% vs. 0.0%), and Olsenella (16.4% vs. 0.0%), and lower abundances of Bacteroides (0.6% vs. 5.7%) and Blautia (0.3% vs. 2.3%) in cats fed the dry diet compared with cats fed the wet diet. These results demonstrate that short-term dietary exposure to diet leads to large shifts in fecal bacterial populations that have the potential to affect the ability of the cat to process macronutrients in the diet.
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A variant upstream of IFNL3 (IL28B) creating a new interferon gene IFNL4 is associated with impaired clearance of hepatitis C virus.
Nat. Genet.
PUBLISHED: 01-06-2013
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Chronic infection with hepatitis C virus (HCV) is a common cause of liver cirrhosis and cancer. We performed RNA sequencing in primary human hepatocytes activated with synthetic double-stranded RNA to mimic HCV infection. Upstream of IFNL3 (IL28B) on chromosome 19q13.13, we discovered a new transiently induced region that harbors a dinucleotide variant ss469415590 (TT or ?G), which is in high linkage disequilibrium with rs12979860, a genetic marker strongly associated with HCV clearance. ss469415590[?G] is a frameshift variant that creates a novel gene, designated IFNL4, encoding the interferon-?4 protein (IFNL4), which is moderately similar to IFNL3. Compared to rs12979860, ss469415590 is more strongly associated with HCV clearance in individuals of African ancestry, although it provides comparable information in Europeans and Asians. Transient overexpression of IFNL4 in a hepatoma cell line induced STAT1 and STAT2 phosphorylation and the expression of interferon-stimulated genes. Our findings provide new insights into the genetic regulation of HCV clearance and its clinical management.
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Use of laser capture microdissection to map hepatitis C virus-positive hepatocytes in human liver.
Gastroenterology
PUBLISHED: 01-04-2013
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Hepatitis C virus (HCV) predominantly infects hepatocytes, but many hepatocytes are not infected; studies have shown that HCV antigens cluster within the liver. We investigated spatial distribution and determinants of HCV replication in human liver samples.
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Post-Weaning Diet Affects Faecal Microbial Composition but Not Selected Adipose Gene Expression in the Cat (Felis catus).
PLoS ONE
PUBLISHED: 01-01-2013
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The effects of pre- (i.e., gestation and during lactation) and post-weaning diet on the composition of faecal bacterial communities and adipose expression of key genes in the glucose and insulin pathways were investigated in the cat. Queens were maintained on a moderate protein:fat:carbohydrate kibbled ("Diet A"; 35:20:28% DM; n ?=? 4) or high protein:fat:carbohydrate canned ("Diet B"; 45:37:2% DM; n?=?3) diet throughout pregnancy and lactation. Offspring were weaned onto these diets in a nested design (n ?=? 5 per treatment). Faecal samples were collected at wk 8 and 17 of age. DNA was isolated from faeces and bacterial 16S rRNA gene amplicons were analysed by pyrosequencing. RNA was extracted from blood (wk 18) and adipose tissue and ovarian/testicular tissues (wk 24) and gene expression levels determined using RT-qPCR. Differences (P<0.05) in composition of faecal bacteria were observed between pregnant queens fed Diet A or B. However, pre-weaning diet had little effect on faecal bacterial composition in weaned kittens. In contrast, post-weaning diet altered bacterial population profiles in the kittens. Increased (P<0.05) abundance of Firmicutes (77% vs 52% of total reads) and Actinobacteria (0.8% vs 0.2% of total reads), and decreased (P<0.05) abundance of Fusobacteria (1.6% vs 18.4% of total reads) were observed for kittens fed the Diet A compared to those fed Diet B post-weaning. Feeding Diet B pre-weaning increased (P<0.05) the expression levels of INRS, LEPT, PAI-1 and tended to increase GLUT1, while the expression levels of IRS-1 in blood increased in kittens fed Diet A pre-weaning. Post-weaning diet had no effect on expression levels of target genes. Correlations between the expression levels of genes involved in glucose and insulin pathways and faecal Bacteriodetes and Firmicutes phyla were identified. The reasons for why post-weaning diet affects microbial populations and not gene expression levels are of interest.
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Using high angular resolution diffusion imaging data to discriminate cortical regions.
PLoS ONE
PUBLISHED: 01-01-2013
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Brodmanns 100-year-old summary map has been widely used for cortical localization in neuroscience. There is a pressing need to update this map using non-invasive, high-resolution and reproducible data, in a way that captures individual variability. We demonstrate here that standard HARDI data has sufficiently diverse directional variation among grey matter regions to inform parcellation into distinct functional regions, and that this variation is reproducible across scans. This characterization of the signal variation as non-random and reproducible is the critical condition for successful cortical parcellation using HARDI data. This paper is a first step towards an individual cortex-wide map of grey matter microstructure, The gray/white matter and pial boundaries were identified on the high-resolution structural MRI images. Two HARDI data sets were collected from each individual and aligned with the corresponding structural image. At each vertex point on the surface tessellation, the diffusion-weighted signal was extracted from each image in the HARDI data set at a point, half way between gray/white matter and pial boundaries. We then derived several features of the HARDI profile with respect to the local cortical normal direction, as well as several fully orientationally invariant features. These features were taken as a fingerprint of the underlying grey matter tissue, and used to distinguish separate cortical areas. A support-vector machine classifier, trained on three distinct areas in repeat 1 achieved 80-82% correct classification of the same three areas in the unseen data from repeat 2 in three volunteers. Though gray matter anisotropy has been mostly overlooked hitherto, this approach may eventually form the foundation of a new cortical parcellation method in living humans. Our approach allows for further studies on the consistency of HARDI based parcellation across subjects and comparison with independent microstructural measures such as ex-vivo histology.
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Dietary isoflavone absorption, excretion, and metabolism in captive cheetahs (Acinonyx jubatus).
J. Zoo Wildl. Med.
PUBLISHED: 12-30-2011
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Dietary isoflavones, capable of influencing reproductive parameters in domestic cats (Felis catus), have been detected in commercial diets fed to captive cheetahs (Acinonyx jubatus). However, the absorptive and metabolic capacity of cheetahs towards isoflavones has not yet been studied. Experiments were designed to describe the plasma concentration-time curve, metabolite profile, and urinary and fecal excretion of genistein and daidzein in cheetahs following consumption of isoflavones. Four adult cheetahs were administered a single oral bolus of genistein and daidzein, and five juvenile cheetahs consuming a milk replacer formula found to contain isoflavones were also included. Urine was collected from all animals, and blood and feces were also collected from adult cheetahs following isoflavone exposure. Samples were analyzed for isoflavone metabolite concentration by liquid chromatography-electrospray ionization-multiple reaction ion monitoring mass spectrometry and high-performance liquid chromatography. Sulfate conjugates were the primary metabolites detected of both genistein and daidzein (60-80% of total isoflavones present) in the plasma and urine of cheetahs. A smaller proportion of daidzein was detected as conjugates in the urine of juvenile cheetahs, compared to adult cheetahs. Other metabolites included unconjugated genistein and daidzein, O-desmethylangolensin, and dihydrodaidzein, but not equol. Only 33% of the ingested genistein dose, and 9% of daidzein, was detected in plasma from adult cheetahs. However, of the ingested dose, 67% of genistein and 45% of daidzein were detected in the feces of adults. This study revealed that cheetahs appear efficient in their conjugation of absorbed dietary isoflavones and only a small fraction of ingested dose is absorbed. However, the capacity of the cheetah to conjugate genistein and daidzein with sulfate moieties appears lower than reported in the domestic cat. This may confer greater opportunity for biologic activity of isoflavones in the cheetah than would be predicted from findings in the domestic cat. However, further investigation is required.
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Five-week dietary exposure to dry diets alters the faecal bacterial populations in the domestic cat (Felis catus).
Br. J. Nutr.
PUBLISHED: 10-19-2011
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The effects of wet (canned) or dry (kibbled) diets on faecal bacterial populations in the cat were investigated in eight domestic short-haired cats (four males and four females; averaging 6 years of age and 3.4 kg) in a nested design. The cats were fed ad libitum a commercially available wet diet (moisture 82.0 %, crude protein 51.7 %, fat 28.9 %, carbohydrate (CHO) 8.9 % and ash 10.6 % DM) for 5 weeks. On the fifth week, individual feed intakes and faecal outputs were determined. Fresh faecal samples were collected twice daily, mixed for homogeneity, subsampled and stored at - 85 °C until analysis. The cats were then switched to a commercially available dry diet (moisture 8.5 %, crude protein 33.0 %, fat 11.0 %, CHO 49.4 % and ash 6.6 % DM) for 5 weeks, and fresh faeces were sampled as described previously. Energy intake tended to be higher in cats fed dry diets (P < 0.10), but body weight was similar between the two feeding periods (P>0.05). Denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA genes amplified from DNA extracted from faeces was performed. The unweighted pair group method with arithmetic mean cluster analysis of bacterial community profiles using Pearsons correlation revealed diet-specific clustering when the same cats were fed on either a dry or a wet diet (dissimilarity between the groups, 88.6 %; P < 0.001). Subsequent cloning and sequencing of five selected distinct DGGE bands indicated that members of the Pelomonas and Fusobacteriaceae were influenced by a short-term change in diet format. This suggests that 5-week dietary exposure is sufficient to alter gastrointestinal microflora.
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High plasma interleukin-18 levels mark the acute phase of hepatitis C virus infection.
J. Infect. Dis.
PUBLISHED: 10-07-2011
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Proinflammatory cytokines play a critical role in antiviral immune responses. Large-scale genome studies have found correlations between single-nucleotide polymorphisms (SNPs) in the interleukin (IL) 18 promoter and spontaneous control of hepatitis C virus (HCV), suggesting a role in clearance.
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Genetic polymorphism in IL28B is associated with spontaneous clearance of hepatitis C virus genotype 4 infection in an Egyptian cohort.
J. Infect. Dis.
PUBLISHED: 09-20-2011
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Single-nucleotide polymorphisms (SNPs) around IL28B are associated with spontaneous hepatitis C virus (HCV) clearance of genotypes 1 and 3 in white and African-American populations. This study investigated whether the IL28B SNP (rs12979860) is associated with spontaneous clearance of HCV, principally genotype 4, in 162 Egyptians (80 with clearance). The protective C allele was more common in those with spontaneous clearance (76.3% vs 57.9%; P = .0006). Individuals with clearance were 3.4 (95% confidence interval, 1.8-6.5) times more likely to have C/C genotype. Thus, IL28B plays a role in spontaneous clearance of HCV genotype 4 in North Africa.
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Human immunodeficiency virus and liver disease forum 2010: conference proceedings.
Hepatology
PUBLISHED: 09-08-2011
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Liver disease continues to represent a critical mediator of morbidity and mortality in those with human immunodeficiency virus (HIV) infection. The frequent presence and overlap of concomitant injurious processes, including hepatitis C virus and hepatitis B virus infections, hepatoxicity associated with antiretroviral therapeutic agents, alcohol, and other toxins, in the setting of immunosuppression lead to rapid fibrotic progression and early development of end-stage liver disease. This conference summary describes the proceedings of a state-of-the-art gathering of international experts designed to highlight the status of current research in epidemiology, natural history, pathogenesis, and treatment of HIV and liver disease.
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No formalin please, it could be TB!
J Perioper Pract
PUBLISHED: 08-31-2011
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Historically, tuberculosis (TB) in the UK was primarily associated with pulmonary infection. However, as the rates of TB in the UK have risen, so has the proportion of extra pulmonary disease. In 1987, the total number of new TB cases was 5,085 and 21% of these were extra pulmonary. By 2009, the annualnumber of TB cases had risen to 9,040 with 46% being extra pulmonary (HPA 2010).
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CXCL9 and CXCL10 chemokines as predictors of liver fibrosis in a cohort of primarily African-American injection drug users with chronic hepatitis C.
J. Infect. Dis.
PUBLISHED: 08-19-2011
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CXCL9 (monokine induced by IFN ? [Mig]) and CXCL10 (interferon [IFN] ?-inducible protein 10 [IP-10]) have been associated with hepatic fibrosis in predominantly white hepatitis C virus (HCV)-infected patients. We investigated their potential as noninvasive markers of hepatic fibrosis and fibrosis progression in African-American patients. Peripheral chemokine levels were measured in 115 HCV-infected patients within 4 months of liver biopsy; patients underwent a second biopsy after 3-5 years. CXCL10 levels appeared to be higher in patients with advanced fibrosis on the contemporaneous biopsy and were significantly higher in patients with advanced fibrosis compared with those with minimal fibrosis on the later biopsy (P = .0045). Therefore, CXCL10 has potential as a marker of fibrosis progression in African-American HCV-infected patients.
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Nutritional status and cognitive performance of mother-child pairs in Sidama, Southern Ethiopia.
Matern Child Nutr
PUBLISHED: 08-02-2011
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The purpose of this study was to assess the nutritional status and cognitive performance of women and their 5-year-old children using a cross-sectional design. Cognitive performance of mothers and children was assessed with Ravens Colored Progressive Matrices (CPM) and Kaufman Assessment Battery for Children-II (KABC-II). Demographic characteristics, food consumption patterns and anthropometry were also measured. Four rural districts in Sidama, southern Ethiopia served as the setting for this study. Subjects were one hundred women and their 5-year-old children. Mean?±?standard deviation age of the mothers was 29?±?6 years and family size was 7.0?±?2.6. Maternal body mass index (BMI) ranged from 15.3 to 29.0 with 14% of the mothers having BMI?
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Magnetisation transfer effects of Q2TIPS pulses in ASL.
MAGMA
PUBLISHED: 07-19-2011
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In pulsed arterial spin labelling (ASL), Q2TIPS saturation pulses are used to actively control the temporal width of the labelled bolus. However, these Q2TIPS pulses also induce magnetisation transfer (MT) effects in the adjacent tissue. In this work, we investigated how Q2TIPS-related MT alters tissue signal in pulsed ASL and, consequently, CBF quantification.
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Epigenetic control of viral life-cycle by a DNA-methylation dependent transcription factor.
PLoS ONE
PUBLISHED: 06-27-2011
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Epstein-Barr virus (EBV) encoded transcription factor Zta (BZLF1, ZEBRA, EB1) is the prototype of a class of transcription factor (including C/EBPalpha) that interact with CpG-containing DNA response elements in a methylation-dependent manner. The EBV genome undergoes a biphasic methylation cycle; it is extensively methylated during viral latency but is reset to an unmethylated state following viral lytic replication. Zta is expressed transiently following infection and again during the switch between latency and lytic replication. The requirement for CpG-methylation at critical Zta response elements (ZREs) has been proposed to regulate EBV replication, specifically it could aid the activation of viral lytic gene expression from silenced promoters on the methylated genome during latency in addition to preventing full lytic reactivation from the non-methylated EBV genome immediately following infection. We developed a computational approach to predict the location of ZREs which we experimentally assessed using in vitro and in vivo DNA association assays. A remarkably different binding motif is apparent for the CpG and non-CpG ZREs. Computational prediction of the location of these binding motifs in EBV revealed that the majority of lytic cycle genes have at least one and many have multiple copies of methylation-dependent CpG ZREs within their promoters. This suggests that the abundance of Zta protein coupled with the methylation status of the EBV genome act together to co-ordinate the expression of lytic cycle genes at the majority of EBV promoters.
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Evaluation of the physical and biological properties of hyaluronan and hyaluronan fragments.
Int J Pharm
PUBLISHED: 06-15-2011
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Hyaluronan (HA) has been extensively used for various medical applications, including osteoarthritis, tissue augmentation and ocular surgery. More recently, it has been investigated for use in polymer therapeutics as a carrier for drugs and biologically active proteins, thanks to its biodegradability, biocompatibility and inherent biological properties. Such biological functions are strongly dependent on HAs chain length, yet the molecular weight of HAs used in polymer conjugates varies widely and is inconsistent with its intended application. Therefore, this study aimed to determine the ideal chain length of HA to be used in polymer conjugates for enhanced tissue repair. HA fragments (M(w) 45,000-900,000g/mol) were prepared by acid hydrolysis of rooster comb HA and their physicochemical and biological properties were characterized. Such HA fragments had a highly extended, almost rod-like solution conformation and demonstrated chain length- and concentration-dependent viscosity, while exposure to HAase caused a rapid reduction in HA viscosity, which was most significant for the native HA. Initial HA hydrolysis rate by HAase varied strongly with HA chain length and was dependent on the formation of a stable enzyme-substrate complex. When normal human dermal fibroblasts were exposed to the different HA fragments for 72h, only native (900,000g/mol) HA reduced proliferation at 1000?g/mL. Conversely, only the smallest HA fragment (70,000g/mol) reduced the proliferation of chronic wound fibroblasts, at 1000?g/mL. The 70,000g/mol HA fragment also promoted the greatest cell attachment. These observations demonstrate that low molecular weight (70,000-120,000g/mol) HA fragments would be best suited for the delivery of proteins and peptides with applications in chronic wound healing and paves the way for the rationalized development of novel HA conjugates.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.