Contribution of Amino Acid Region 334−335 from Factor Va Heavy Chain to the Catalytic Efficiency of Prothrombinase†

ABSTRACT: We have demonstrated that amino acids E323, Y324, E330, and V331 from the factor Va heavy chain are required for the interaction of the cofactor with factor Xa and optimum rates of prothrombin cleavage. We have also shown that amino acid region 332-336 contains residues that are important for cofactor function. Using overlapping peptides, we identified amino acids D334 and Y335 as contributors to cofactor activity. We constructed recombinant factor V molecules with the mutations D334 f K and Y335 f F (factor VKF) and D334 f A and Y335 f A (factor VAA). Kinetic studies showed that while factor VaKF and factor VaAA had a KD for factor Xa similar to the KD observed for wild-type factor Va (factor VaWT), the clotting activities of the mutant molecules were impaired and the kcat of prothrombinase assembled with factor VaKF and factor VaAA was reduced. The second-order rate constant of prothrombinase assembled with factor VaKF or factor VaAA for prothrombin activation was ∼10-fold lower than the second-order rate constant for the same reaction catalyzed by prothrombinase assembled with factor VaWT. We also created quadruple mutants combining mutations in the amino acid region 334–335 with mutations at the previously identified amino acids that are important for factor Xa binding (i.e., E323Y324 and E330V331). Prothrombinase assembled with the quadruple mutant molecules displayed a second-order rate constant up to 400-fold lower than the values obtained with prothrombinase assembled with factor VaWT. The dat

Where’s the risk? Landscape epidemiology of gastrointestinal parasitism in Alberta beef cattle

Sherpa Romeo green journal; open accessBackground: Gastrointenstinal nematodes (GIN) present a serious challenge to the health and productivity of grazing stock around the globe. However, the epidemiology of GIN transmission remains poorly understood in northern climates. Combining use of serological diagnostics, GIS mapping technology, and geospatial statistics, we evaluated ecological covariates of spatial and temporal variability in GIN transmission among bovine calves pastured in Alberta, Canada. Methods: Sera were collected from 1000 beef calves across Alberta, Canada over three consecutive years (2008–2010) and analyzed for presence of anti-GIN antibodies using the SVANOVIR Ostertagia osteragi-Ab ELISA kit. Using a GIS and Bayesian multivariate spatial statistics, we evaluated the degree to which variation in specific environmental covariates (e.g. moisture, humidity, temperature) was associated with variation in spatial and temporal heterogeneity in exposure to GIN (Nematodirus and other trichostrongyles, primarily Ostertagia and Cooperia). Results: Variation in growing degree days above a base temperature of 5 °C, humidity, air temperature, and accumulated precipitation were found to be significant predictors of broad–scale spatial and temporal variation in serum antibody concentrations. Risk model projections identified that while transmission in cattle from southeastern and northwestern Alberta was relatively low in all years, rate of GIN transmission was generally higher in the central region of Alberta. Conclusions: The spatial variability in risk is attributed to higher average humidity, precipitation and moderate temperatures in the central region of Alberta in comparison with the hot, dry southeastern corner of the province and the cool, dry northwestern corner. Although more targeted sampling is needed to improve model accuracy, our projections represent an important step towards tying treatment recommendations to actual risk of infection.Ye

GMO vs. Non-GMO: Comparing the Addictiveness of Corn in Rats

Genetically modified organisms (GMOs) refer to organisms whose DNA has been altered to produce a certain characteristic. GMOs account for a significant proportion of the crops produced in the United States. Specifically, GMO corn accounted for approximately 88% of all corn grown for human and animal consumption in the year 2012. Previously conducted studies have not uniformly demonstrated the safe use of GMO corn, and no studies have been conducted to analyze the addictiveness of GMO corn. The idea of addiction refers to more than just a physical dependence, but to a psychological dependence on something as well. Addiction is sometimes accompanied by compulsive, uncontrollable behaviors that can interfere with other activities and which increase in intensity as there is an increase in access to the substance. Because food addiction is implicated in the prevalence of obesity and its associated pathologies, identifying addictiveness in GMO products may lead to changes in crop production, food production, and use. This study will compare the addictive behaviors of rats who are fed GMO corn. The rats will be randomly divided into three groups. Each group will be fed a diet containing a portion of corn consisting of 0%, 50%, or 100% GMO corn, respectively, for 28 days. After the 28 day treatment period, the rats will be fed a corn-free diet for 10 days. The assessments will include both cage food consumption and body weight measurements taken during both the treatment and withdrawal periods, and behavioral symptoms observed in an open field test during the withdrawal period. The presence of withdrawal indicators will be scored for each rat. The scores will then be compared between the groups using a repeated measures ANOVA test

GMO vs. Non-GMO: Comparing the Addictiveness of Corn in Rats

Genetically modified organisms (GMOs) refer to organisms whose DNA has been altered to produce a certain characteristic. GMOs account for a significant proportion of the crops produced in the United States. Specifically, GMO corn accounted for approximately 88% of all corn grown for human and animal consumption in the year 2012. Previously conducted studies have not uniformly demonstrated the safe use of GMO corn, and no studies have been conducted analyzing the addictiveness of GMO corn. The idea of addiction refers to more than just a physical dependence, but to a psychological dependence on something as well. It is sometimes accompanied by compulsive, uncontrollable behaviors that can interfere with other activities and which increase in intensity as there is an increase in access to the substance. Because food addiction is implicated in the prevalence of obesity and its associated pathologies, identifying addictiveness in GMO products may lead to changes in crop production, food production, and use. This study will compare the addictive behaviors of rats who are fed GMO corn. The rats will be randomly divided into three groups. Each group will be fed a diet containing a portion of corn consisting of 0%, 50%, or 100% GMO corn, respectively, for 28 days. After the 28 day treatment period, the rats will be fed a corn-free diet for 10 days. The assessments will include both cage food consumption and body weight measurements taken during both the treatment and withdrawal periods, and behavioral symptoms observed in an open field test during the withdrawal period. The presence of withdrawal indicators will be scored for each rat, and the scores will be compared between the groups using a repeated measures ANOVA test

Ecological epidemiology of an invasive host generalist parasite, Dicrocoelium dendriticum, in Cypress Hills Interprovincial Park, Alberta

Innate variability in parasite transmission is one of the hallmarks of the phenomenon of parasitism. Empirical research aimed at quantifying these differences is limited, particularly for generalist parasites that utilize a broad range of sympatric hosts. Using an ecological epidemiological approach, I characterized variability in transmission of an emerging host generalist parasite, Dicrocoelium dendriticum, in Cypress Hills Interprovincial Park, Alberta. ‘Hotspots’ for ant-to-ungulate transmission were characterized by the presence of aspen (Populus tremuloides) trees on moderately graded, south, or east facing slopes at elevation > 1300m. Individual fluke performance and per capita fecundity were approximately equal among naturally-infected elk and experimentally-infected sheep and cattle. However, when these data were combined with host population size and host residency time in CHP, the sub-population of roughly 4000 cow/calves that are pastured in CHP contribute approximately 80% of the estimated 300 billion eggs that contaminate pasture each year.Beef Cattle Research Council: Grant no. 2008F064; Feedlot Health Management Services: Grant no. FHMS-1039; Alberta Livestock and Meat Agency Ltd.: Grant no. 2011R041R; the Agriculture Funding Consortium: Grant no. AB-0450; Agriculture and Agri-food Canada: Grant no. RBP-842; National Sciences and Engineering Research Council of Canada; Grant no. 40130; The Alberta Conservation Association Grant in Biodiversity; Zoeti

“After a finding of Noncompliance, What?!”

Treaties have long been the cornerstones of international relations. They can be seen as one of the sole mechanisms to formalize agreements between sovereign states. In principle, these agreements are legally binding. In practice, the result is less certain. Issues ranging from the how the country views itself on the international stage to the specific treaty terms and enforcement mechanisms can all effect prospects for compliance. What is certain is the disruption and uncertainty that noncompliance causes. If not addressed, a treaty’s utility will eventually erode to the point where the agreement has no force. Other countries would also perceive little value in treaty ratification if compliance cannot be sufficiently verified. This report focuses on current issues of noncompliance with Russia, Syria, Iran, and North. Korea. Key themes arise across these cases and point to specific factors that impact treaty compliance. The report distills these key themes into general and case-specific recommendations for bringing a country back from noncompliance

Pharmacokinetic, neurochemical, stereological and neuropathological studies on the potential effects of paraquat in the substantia nigra pars compacta and striatum of male C57BL/6J mice

AbstractThe pharmacokinetics and neurotoxicity of paraquat dichloride (PQ) were assessed following once weekly administration to C57BL/6J male mice by intraperitoneal injection for 1, 2 or 3 weeks at doses of 10, 15 or 25mg/kg/week. Approximately 0.3% of the administered dose was taken up by the brain and was slowly eliminated, with a half-life of approximately 3 weeks. PQ did not alter the concentration of dopamine (DA), homovanillic acid (HVA) or 3,4-dihydroxyphenylacetic acid (DOPAC), or increase dopamine turnover in the striatum. There was inconsistent stereological evidence of a loss of DA neurons, as identified by chromogenic or fluorescent-tagged antibodies to tyrosine hydroxylase in the substantia nigra pars compacta (SNpc). There was no evidence that PQ induced neuronal degeneration in the SNpc or degenerating neuronal processes in the striatum, as indicated by the absence of uptake of silver stain or reduced immunolabeling of tyrosine-hydroxylase-positive (TH+) neurons. There was no evidence of apoptotic cell death, which was evaluated using TUNEL or caspase 3 assays. Microglia (IBA-1 immunoreactivity) and astrocytes (GFAP immunoreactivity) were not activated in PQ-treated mice 4, 8, 16, 24, 48, 96 or 168h after 1, 2 or 3 doses of PQ.In contrast, mice dosed with the positive control substance, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 10mg/kg/dose×4 doses, 2h apart), displayed significantly reduced DA and DOPAC concentrations and increased DA turnover in the striatum 7 days after dosing. The number of TH+ neurons in the SNpc was reduced, and there were increased numbers of degenerating neurons and neuronal processes in the SNpc and striatum. MPTP-mediated cell death was not attributed to apoptosis. MPTP activated microglia and astrocytes within 4h of the last dose, reaching a peak within 48h. The microglial response ended by 96h in the SNpc, but the astrocytic response continued through 168h in the striatum.These results bring into question previous published stereological studies that report loss of TH+ neurons in the SNpc of PQ-treated mice. This study also suggests that even if the reduction in TH+ neurons reported by others occurs in PQ-treated mice, this apparent phenotypic change is unaccompanied by neuronal cell death or by modification of dopamine levels in the striatum

The Prevalence of Sexual and Gender Minority Youth in the Justice System: A Systematic Review and Meta-Analysis

Theoretical models, such as the minority stress model, suggest that sexual and gender minority (SGM) youth may be overrepresented in the justice system. However, few studies have examined rates of SGM youth in the system, and even fewer have compared them with rates of these youth in the broader community. To obtain a more accurate estimate, we conducted a systematic review and meta-analysis of 31,258 youths and compared rates of SGM youth in the justice system with those in the community. Contrary to claims that SGM youth are overrepresented generally, this review suggests that sexual minority girls, specifically, are disproportionally involved in the justice system. Rates of involvement appeared to differ across ethnic subgroups of sexual minority youth, and evidence is inconclusive regarding the prevalence of gender minority youth in the system. Implications of these findings for researchers and justice system professionals are discussed

Effects of High-Volume Versus High-Load Resistance Training on Skeletal Muscle Growth and Molecular Adaptations

We evaluated the effects of higher-load (HL) versus (lower-load) higher-volume (HV) resistance training on skeletal muscle hypertrophy, strength, and muscle-level molecular adaptations. Trained men (n = 15, age: 23 ± 3 years; training experience: 7 ± 3 years) performed unilateral lower-body training for 6 weeks (3× weekly), where single legs were randomly assigned to HV and HL paradigms. Vastus lateralis (VL) biopsies were obtained prior to study initiation (PRE) as well as 3 days (POST) and 10 days following the last training bout (POSTPR). Body composition and strength tests were performed at each testing session, and biochemical assays were performed on muscle tissue after study completion. Two-way within-subject repeated measures ANOVAs were performed on most dependent variables, and tracer data were compared using dependent samples t-tests. A significant interaction existed for VL muscle cross-sectional area (assessed via magnetic resonance imaging; interaction p = 0.046), where HV increased this metric from PRE to POST (+3.2%, p = 0.018) whereas HL training did not (−0.1%, p = 0.475). Additionally, HL increased leg extensor strength more so than HV training (interaction p = 0.032; HV \u3c HL at POST and POSTPR, p \u3c 0.025 for each). Six-week integrated non-myofibrillar protein synthesis (iNon-MyoPS) rates were also higher in the HV versus HL condition, while no difference between conditions existed for iMyoPS rates. No interactions existed for other strength, VL morphology variables, or the relative abundances of major muscle proteins. Compared to HL training, 6 weeks of HV training in previously trained men optimizes VL hypertrophy in lieu of enhanced iNon-MyoPS rates, and this warrants future research