472 research outputs found

    Serum-Free Serial Culture of Adult Human Keratinocytes From Suction-Blister Roof Epidermis

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    Coating cell culture flasks with natural extracellular matrix (ECM) enhanced the culture of adult human keratinocytes from suction-blister roof epidermis in an environment without fetal calf serum (FCS), bovine pituitary extracts or cellular feeder layers. A higher incidence of cell attachment on natural ECM was observed than on collagen and human fibronectins(HFN)-coated plastic dishes, and natural ECM was necessary for growth and proliferation of attached cells under the culture conditions used. Cells in primary culture grew to confluency on natural ECM-coated surfaces within about 14 days, and subsequent serial passage could be made up to fourth passage in collagen- and HFN-coated plastic flasks. Cultured keratinocytes in this serum-free environment formed colonies of small cuboidal, healthy cells with little keratinization or stratification and demonstrated antigenic characteristics of human basal cells

    Lipoprotein(a) is associated differentially with carotid stenosis, occlusion, and total plaque area

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    Background - Lipoprotein(a) [Lp(a)] is a putative risk factor for myocardial infarction and stroke and is related to thrombosis and impaired fibrinolysis. We studied relationships of Lp(a) with carotid stenosis, occlusion, and total plaque area, distinct phenotypes of atherosclerosis that may be differentially affected by cardiovascular risk factors. Methods and Results - Multivariable linear regression analysis was used to study relationships of Lp(a) to phenotypes of carotid atherosclerosis among 876 consecutive patients from an atherosclerosis prevention clinic with complete data for all variables used in the model. Occlusion of an internal carotid artery was present in 22 (2.5%) patients (one with bilateral occlusions). Risk factors predicted carotid plaque area, stenosis, and occlusion differently. Lp(a) was a significant independent predictor of baseline stenosis (P\u3c0.0001) but not of plaque area (P=0.13); in logistic regression, Lp(a) significantly predicted occlusion (P=0.001). Patients with occlusion had significantly higher levels of Lp(a): 0.27±0.25 g/L versus 0.17±0.18 g/L without occlusion; P=0.007. Conclusion - Lp(a) was a significant independent predictor of carotid stenosis and occlusion, but not of carotid plaque area, supporting the hypothesis that the effect of Lp(a) on atherogenesis and cardiovascular risk is largely related to thrombosis and impaired fibrinolysis. Stenosis and occlusion may not be attributable to plaque progression, but to plaque rupture and thrombosis; this relationship may also apply to other arterial beds. © 2008 American Heart Association, Inc

    Climate vulnerability assessment for Pacific salmon and steelhead in the California Current Large Marine Ecosystem.

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    Major ecological realignments are already occurring in response to climate change. To be successful, conservation strategies now need to account for geographical patterns in traits sensitive to climate change, as well as climate threats to species-level diversity. As part of an effort to provide such information, we conducted a climate vulnerability assessment that included all anadromous Pacific salmon and steelhead (Oncorhynchus spp.) population units listed under the U.S. Endangered Species Act. Using an expert-based scoring system, we ranked 20 attributes for the 28 listed units and 5 additional units. Attributes captured biological sensitivity, or the strength of linkages between each listing unit and the present climate; climate exposure, or the magnitude of projected change in local environmental conditions; and adaptive capacity, or the ability to modify phenotypes to cope with new climatic conditions. Each listing unit was then assigned one of four vulnerability categories. Units ranked most vulnerable overall were Chinook (O. tshawytscha) in the California Central Valley, coho (O. kisutch) in California and southern Oregon, sockeye (O. nerka) in the Snake River Basin, and spring-run Chinook in the interior Columbia and Willamette River Basins. We identified units with similar vulnerability profiles using a hierarchical cluster analysis. Life history characteristics, especially freshwater and estuary residence times, interplayed with gradations in exposure from south to north and from coastal to interior regions to generate landscape-level patterns within each species. Nearly all listing units faced high exposures to projected increases in stream temperature, sea surface temperature, and ocean acidification, but other aspects of exposure peaked in particular regions. Anthropogenic factors, especially migration barriers, habitat degradation, and hatchery influence, have reduced the adaptive capacity of most steelhead and salmon populations. Enhancing adaptive capacity is essential to mitigate for the increasing threat of climate change. Collectively, these results provide a framework to support recovery planning that considers climate impacts on the majority of West Coast anadromous salmonids

    Early Ocean Distribution of Juvenile Chinook Salmon in an Upwelling Ecosystem

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    Extreme variability in abundance of California salmon populations is often ascribed to ocean conditions, yet relatively little is known about their marine life-history. To investigate which ocean conditions influence their distribution and abundance, we surveyed juvenile Chinook salmon (Oncorhynchus tshawytscha) within the California Current (central California (37o 30’ N) to Newport, Oregon (44o 00’ N)) for a two-week period over three summers (2010-2012). At each station, we measured chlorophyll a as an indicator of primary productivity, acoustic-based metrics of zooplankton density as an indicator of potential prey availability, and physical characteristics such as bottom depth, temperature, and salinity. We also measured fork lengths and collected genetic samples from each salmon that was caught. Genetic stock identification revealed that the majority of juvenile salmon were from the Central Valley and the Klamath Basin (91-98%). We constructed generalized logistic-linear negative binomial hurdle models and chose the best model(s) using AIC to determine which covariates influenced salmon presence and, at locations where salmon were present, determined the variables that influenced their abundance. The probability of salmon presence was highest in shallower waters with high chlorophyll a concentration and close to an individual’s natal river. Catch abundance was primarily influenced by year, mean fork length, and proximity to natal rivers. At the scale of sampling stations, presence and abundance was not related to acoustic indices of zooplankton density. In the weeks to months following ocean entry, California’s juvenile Chinook salmon population appears to be primarily constrained to coastal waters near natal river outlets

    Detection of Distant Relatedness in Biobanks To Identify Undiagnosed Cases of Mendelian Disease As Applied to Long Qt Syndrome

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    Rare genetic diseases are typically studied in referral populations, resulting in underdiagnosis and biased assessment of penetrance and phenotype. To address this, we develop a generalizable method of genotype inference based on distant relatedness and deploy this to identify undiagnosed Type 5 Long QT Syndrome (LQT5) rare variant carriers in a non-referral population. We identify 9 LQT5 families referred to a single specialty clinic, each carrying p.Asp76Asn, the most common LQT5 variant. We uncover recent common ancestry and a single shared haplotype among probands. Application to a non-referral population of 69,819 BioVU biobank subjects identifies 22 additional subjects sharing this haplotype, which we confirm to carry p.Asp76Asn. Referral and non-referral carriers have prolonged QT interval corrected for heart rate (QTc) compared to controls, and, among carriers, the QTc polygenic score is independently associated with QTc prolongation. Thus, our innovative analysis of shared chromosomal segments identifies undiagnosed cases of genetic disease and refines the understanding of LQT5 penetrance and phenotype

    Germline Genetic Variants and Pediatric Rhabdomyosarcoma Outcomes: A Report From the Children’s Oncology Group

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    BACKGROUND: Relative to other pediatric cancers, survival for rhabdomyosarcoma (RMS) has not improved in recent decades, suggesting the need to enhance risk stratification. Therefore, we conducted a genome-wide association study for event-free survival (EFS) and overall survival (OS) to identify genetic variants associated with outcomes in individuals with RMS. METHODS: The study included 920 individuals with newly diagnosed RMS who were enrolled in Children\u27s Oncology Group protocols. To assess the association of each single nucleotide polymorphism (SNP) with EFS and OS, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using multivariable Cox proportional hazards models, adjusted for clinical covariates. All statistical tests were two sided. We also performed stratified analyses by histological subtype (alveolar and embryonal RMS) and carried out sensitivity analyses of statistically significant SNPs by PAX3/7-FOXO1 fusion status and genetic ancestry group. RESULTS: We identified that rs17321084 was associated with worse EFS (HR = 2.01, 95% CI = 1.59 to 2.53, P = 5.39 × 10-9) and rs10094840 was associated with worse OS (HR = 1.84, 95% CI = 1.48 to 2.27, P = 2.13 × 10-8). Using publicly available data, we found that rs17321084 lies in a binding region for transcription factors GATA2 and GATA3, and rs10094840 is associated with SPAG1 and RNF19A expression. We also identified that CTNNA3 rs2135732 (HR = 3.75, 95% CI = 2.34 to 5.99, P = 3.54 × 10-8) and MED31 rs74504320 (HR = 3.21, 95% CI = 2.12 to 4.86, P = 3.60 × 10-8) were associated with worse OS among individuals with alveolar RMS. CONCLUSIONS: We demonstrated that common germline variants are associated with EFS and OS among individuals with RMS. Additional replication and investigation of these SNP effects may further support their consideration in risk stratification protocols

    Phenotypic Plasticity of Leaf Shape along a Temperature Gradient in Acer rubrum

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    Both phenotypic plasticity and genetic determination can be important for understanding how plants respond to environmental change. However, little is known about the plastic response of leaf teeth and leaf dissection to temperature. This gap is critical because these leaf traits are commonly used to reconstruct paleoclimate from fossils, and such studies tacitly assume that traits measured from fossils reflect the environment at the time of their deposition, even during periods of rapid climate change. We measured leaf size and shape in Acer rubrum derived from four seed sources with a broad temperature range and grown for two years in two gardens with contrasting climates (Rhode Island and Florida). Leaves in the Rhode Island garden have more teeth and are more highly dissected than leaves in Florida from the same seed source. Plasticity in these variables accounts for at least 6–19 % of the total variance, while genetic differences among ecotypes probably account for at most 69–87 %. This study highlights the role of phenotypic plasticity in leaf-climate relationships. We suggest that variables related to tooth count and leaf dissection in A. rubrum can respond quickly to climate change, which increases confidence in paleoclimate methods that use these variables
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