240 research outputs found
SEASONAL INCIDENCE OF CAPTURE AND REPRODUCTION OF FIVE FOSSORIAL SNAKE SPECIES IN WEST VIRGINIA
Museum specimens of five species of fossorial snakes collected in West Virginia during 1930–2000 were examined to determine monthly incidence of capture, adult body sizes, reproductive cycle, and clutch characteristics. Captures occurred over the shortest time in the year in the Eastern Earthsnake (Virginia valeriae valeriae) and Northern Red-bellied Snake (Storeria occipitomaculata occipitomaculata) and were longest in the Northern Brownsnake (S. dekayi dekayi). Male gonadal cycle conformed to the temperate pattern, whereas that of females tended towards a tropical pattern. Incidence of females nearing oviposition or parturition was highest during June–July for all species, and length of their reproductive seasons were generally in keeping with those of northerly populations of the respective species. Mean clutch sizes were largest in the Northern Brownsnake (mean = 20.5) and smallest in the single oviparous snake, the Eastern Wormsnake (mean = 2.8). Adult body sizes were similar to respective populations elsewhere within their ranges. The Mountain Earth Snake (V. pulchra) was the least represented species in this study. A meaningful degree of predictability existed in the life history traits examined in our study as they related to geographic trends of this Allegheny snake assemblage
Ocean currents help explain population genetic structure
Management and conservation can be greatly informed by considering explicitly how environmental factors influence population genetic structure. Using simulated larval dispersal estimates based on ocean current observations, we demonstrate how explicit consideration of frequency of exchange of larvae among sites via ocean advection can fundamentally change the interpretation of empirical population genetic structuring as compared with conventional spatial genetic analyses. Both frequency of larval exchange and empirical genetic difference were uncorrelated with Euclidean distance between sites. When transformed into relative oceanographic distances and integrated into a genetic isolation-by-distance framework, however, the frequency of larval exchange explained nearly 50 per cent of the variance in empirical genetic differences among sites over scales of tens of kilometres. Explanatory power was strongest when we considered effects of multiple generations of larval dispersal via intermediary locations on the long-term probability of exchange between sites. Our results uncover meaningful spatial patterning to population genetic structuring that corresponds with ocean circulation. This study advances our ability to interpret population structure from complex genetic data characteristic of high gene flow species, validates recent advances in oceanographic approaches for assessing larval dispersal and represents a novel approach to characterize population connectivity at small spatial scales germane to conservation and fisheries management
Effect of Hypoglycemia on Inflammatory Responses and the Response to Low Dose Endotoxemia in Humans
Context: Hypoglycemia is emerging as a risk for cardiovascular events in diabetes. We hypothesized that hypoglycemia activates the innate immune system, which is known to increase cardiovascular risk. Objective: To determine whether hypoglycemia modifies subsequent innate immune system responses. Design and Setting: Single-blinded, prospective study of three independent parallel groups. Participants and Interventions: Twenty-four healthy participants underwent either a hyperinsulinemic-hypoglycemic (2.5 mmol/l), euglycemic (6.0 mmol/l) or sham-saline clamp (n=8 for each group). Forty-eight hours later, all participants received low-dose (0.3 ng/kg) intravenous endotoxin. Main outcome measures: We studied in-vivo monocyte mobilization and monocyte-platelet interactions. Results: Hypoglycemia increased total leucocytes (9.98±1.14 x109/l vs euglycemia: 4.38±0.53 x109/l; P<0.001 vs sham-saline: 4.76±0.36 x109/l; P<0.001) (mean±SEM), mobilized proinflammatory intermediate monocytes (42.20±7.52/μl vs euglycemia: 20.66±3.43/μl; P<0.01 vs sham-saline: 26.20±3.86/μl; P<0.05) and non-classical monocytes (36.16±4.66/μl vs euglycemia: 12.72±2.42/μl; P<0.001 vs sham-saline: 19.05±3.81/μl; P<0.001). Following hypoglycemia vs euglycemia, platelet aggregation to agonist (AUC) increased (73.87±7.30 vs 52.50±4.04; P<0.05) and formation of monocyte-platelet aggregates increased (96.05±14.51/μl vs 49.32±6.41/μl; P<0.05). Within monocyte subsets, hypoglycemia increased aggregation of intermediate monocytes (10.51±1.42/μl vs euglycemia: 4.19±1.08/μl; P<0.05 vs sham-saline: 3.81±1.42/μl; P<0.05) and non-classical monocytes (9.53±1.08/μl vs euglycemia: 2.86±0.72/μl; P<0.01 vs sham-saline: 3.08±1.01/μl; P<0.05) with platelets compared to controls. Hypoglycemia led to greater leucocyte mobilization in response to subsequent low-dose endotoxin challenge (10.96±0.97 vs euglycemia: 8.21±0.85 x109/l; P<0.05). Conclusions: Hypoglycemia mobilizes monocytes, increases platelet reactivity, promotes interaction between platelets and proinflammatory monocytes, and potentiates the subsequent immune response to endotoxin. These changes may contribute towards increased cardiovascular risk observed in people with diabetes
Citrobacter rodentium Subverts ATP Flux and Cholesterol Homeostasis in Intestinal Epithelial Cells In Vivo.
The intestinal epithelial cells (IECs) that line the gut form a robust line of defense against ingested pathogens. We investigated the impact of infection with the enteric pathogen Citrobacter rodentium on mouse IEC metabolism using global proteomic and targeted metabolomics and lipidomics. The major signatures of the infection were upregulation of the sugar transporter Sglt4, aerobic glycolysis, and production of phosphocreatine, which mobilizes cytosolic energy. In contrast, biogenesis of mitochondrial cardiolipins, essential for ATP production, was inhibited, which coincided with increased levels of mucosal O2 and a reduction in colon-associated anaerobic commensals. In addition, IECs responded to infection by activating Srebp2 and the cholesterol biosynthetic pathway. Unexpectedly, infected IECs also upregulated the cholesterol efflux proteins AbcA1, AbcG8, and ApoA1, resulting in higher levels of fecal cholesterol and a bloom of Proteobacteria. These results suggest that C. rodentium manipulates host metabolism to evade innate immune responses and establish a favorable gut ecosystem
R2Play development: Fostering user-driven technology that supports return-to-play decision-making following pediatric concussion
ObjectiveTo design a multi-domain return-to-play assessment system (R2Play) for youth athletes with concussion.MethodsThe R2Play system was developed using an overarching user-centered approach, the Design Thinking Framework, and research activities included: 1) structured brainstorming within our research team, 2) interviews with clinician and youth sports coaches, 3) building a testable prototype, and 4) interface testing through cognitive walkthroughs with clinician partners.ResultsClinician and coach participants provided feedback on the R2Play concept, which was integrated into the design process and provided future directions for research. Examples of feedback-driven design choices included reducing assessment time, increasing ecological validity by adding in background noise, and developing youth-friendly graphical results screens. Following refinement based on stakeholder feedback, the R2Play system was outlined in detail and a testable prototype was developed. It is made up of two parts: a clinician tablet, and a series of tablet “buttons” that display numbers and letters. Youth athletes run between the buttons to connect a “trail” in ascending alphanumeric order, 1-A-2-B, etc. Their performance across a series of levels of increasing difficulty is logged on the clinician tablet. Initial testing with five clinicians showed the system's interface to have excellent usability with a score of 81% (SD = 8.02) on the System Usability Scale.ConclusionThrough this research, a prototype of the R2Play system was innovated and evaluated by clinician and coach stakeholders. Initial usability was excellent and directions for future iterations were highlighted. Outcomes suggest the potential benefits of using technologies to assist in complex clinical assessment, as well as utilizing a user-centered approach to design
The perception of quinine taste intensity is associated with common genetic variants in a bitter receptor cluster on chromosome 12
The perceived taste intensities of quinine HCl, caffeine, sucrose octaacetate (SOA) and propylthiouracil (PROP) solutions were examined in 1457 twins and their siblings. Previous heritability modeling of these bitter stimuli indicated a common genetic factor for quinine, caffeine and SOA (22–28%), as well as separate specific genetic factors for PROP (72%) and quinine (15%). To identify the genes involved, we performed a genome-wide association study with the same sample as the modeling analysis, genotyped for approximately 610 000 single-nucleotide polymorphisms (SNPs). For caffeine and SOA, no SNP association reached a genome-wide statistical criterion. For PROP, the peak association was within TAS2R38 (rs713598, A49P, P = 1.6 × 10−104), which accounted for 45.9% of the trait variance. For quinine, the peak association was centered in a region that contains bitter receptor as well as salivary protein genes and explained 5.8% of the trait variance (TAS2R19, rs10772420, R299C, P = 1.8 × 10−15). We confirmed this association in a replication sample of twins of similar ancestry (P = 0.00001). The specific genetic factor for the perceived intensity of PROP was identified as the gene previously implicated in this trait (TAS2R38). For quinine, one or more bitter receptor or salivary proline-rich protein genes on chromosome 12 have alleles which affect its perception but tight linkage among very similar genes precludes the identification of a single causal genetic variant
New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.
Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes
Varespladib and cardiovascular events in patients with an acute coronary syndrome: the VISTA-16 randomized clinical trial
IMPORTANCE: Secretory phospholipase A2(sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE: To determine the effects of sPLA2inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS: Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES: The primary efficacy measurewas a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS: At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95%CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95%CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE: In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01130246. Copyright 2014 American Medical Association. All rights reserved
Acute appendicitis: transcript profiling of blood identifies promising biomarkers and potential underlying processes
Background The diagnosis of acute appendicitis can be surprisingly difficult without computed tomography, which carries significant radiation exposure. Circulating blood cells may carry informative changes in their RNA expression profile that would signal internal infection or inflammation of the appendix. Methods Genome-wide expression profiling was applied to whole blood RNA of acute appendicitis patients versus patients with other abdominal disorders, in order to identify biomarkers of appendicitis. From a large cohort of emergency patients, a discovery set of patients with surgically confirmed appendicitis, or abdominal pain from other causes, was identified. RNA from whole blood was profiled by microarrays, and RNA levels were filtered by a combined fold-change (\u3e2) and p value (\u3c0.05). A separate set of patients, including patients with respiratory infections, was used to validate a partial least squares discriminant (PLSD) prediction model. Results Transcript profiling identified 37 differentially expressed genes (DEG) in appendicitis versus abdominal pain patients. The DEG list contained 3 major ontologies: infection-related, inflammation-related, and ribosomal processing. Appendicitis patients had lower level of neutrophil defensin mRNA (DEFA1,3), but higher levels of alkaline phosphatase (ALPL) and interleukin-8 receptor-ß (CXCR2/IL8RB), which was confirmed in a larger cohort of 60 patients using droplet digital PCR (ddPCR). Conclusions Patients with acute appendicitis have detectable changes in the mRNA expression levels of factors related to neutrophil innate defense systems. The low defensin mRNA levels suggest that appendicitis patient’s immune cells are not directly activated by pathogens, but are primed by diffusible factors in the microenvironment of the infection. The detected biomarkers are consistent with prior evidence that biofilm-forming bacteria in the appendix may be an important factor in appendicitis
The Human Phenotype Ontology project:linking molecular biology and disease through phenotype data
The Human Phenotype Ontology (HPO) project, available at http://www.human-phenotype-ontology.org, provides a structured, comprehensive and well-defined set of 10,088 classes (terms) describing human phenotypic abnormalities and 13,326 subclass relations between the HPO classes. In addition we have developed logical definitions for 46% of all HPO classes using terms from ontologies for anatomy, cell types, function, embryology, pathology and other domains. This allows interoperability with several resources, especially those containing phenotype information on model organisms such as mouse and zebrafish. Here we describe the updated HPO database, which provides annotations of 7,278 human hereditary syndromes listed in OMIM, Orphanet and DECIPHER to classes of the HPO. Various meta-attributes such as frequency, references and negations are associated with each annotation. Several large-scale projects worldwide utilize the HPO for describing phenotype information in their datasets. We have therefore generated equivalence mappings to other phenotype vocabularies such as LDDB, Orphanet, MedDRA, UMLS and phenoDB, allowing integration of existing datasets and interoperability with multiple biomedical resources. We have created various ways to access the HPO database content using flat files, a MySQL database, and Web-based tools. All data and documentation on the HPO project can be found online
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