1,969 research outputs found

    Impact of Polymorphisms in PTK2 on Intrinsic Muscle Strength

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    Abstract Title: Impact of Polymorphisms in PTK2 on Intrinsic Muscle Strength Primary Presenter Full Name: Zachary Zeller Co-presenter Full Name(s): Click here to enter text. Co-author Full Name(s): Mohamed Al-Amoodi, Whitney Jones, Danny Lee, Steven Mckenzie, Helen Miller, Seth Stubblefied, Susan Knoblach, Heather Gordish-Dressman, Dustin Hittel, Laura L. Tosi Abstract Text (should not exceed 400 words): Recent studies have begun to search for correlations between genetic variations and muscle strength. One such study by Stebbings et al.1 examined two single nucleotide polymorphisms (SNPs)—rs7843014 and rs7460—on the PTK2 gene. The study found that genetic variation in the PTK2 gene impacts muscle-specific force, which is the force generated per unit of cross-sectional area of muscle. Muscle-specific force ultimately represents the intrinsic strength of a muscle and is a key determinant of functional capacity and mobility. This study sought to expand on prior research by looking for associations between genetic variants of PTK2 and measures of grip strength, as well as general anthropomorphic measures, in a cohort of healthy young adults. Our study assessed phenotypes for height, weight, VO2 max, max grip strength, and body mass index (BMI) using the Assessing Inherited Markers of Metabolic Syndrome in the Young (AIMMY) University of Calgary subset of 190 healthy, primarily Caucasian, individuals between the ages of 18 and 35. DNA samples were genotyped using ThermoFisher Taqman SNP genotype assays, and underwent the Applied Biosystems 7900HT real-time polymerase chain reaction (PCR) process. Analysis of covariance (ANCOVA) models were used to perform statistical analysis to look for genotype-phenotype associations. Unlike the findings by Stebbings et al.1 an association between the PTK2 genotypes and grip strength was not found. This could be due to the lower statistical power in the grip strength test, thus potentially indicating that grip strength and muscle-specific force do not measure similar parameters of muscle strength. Genetic variation in PTK2 has also been previously associated with VO2 max, but no association was found in the current study. Positive associations were found between genetic variants rs7843014 and rs7460 in PTK2 and BMI, and between genetic variant rs7843014 and height. High levels of functioning PTK2 have been found to have increased strength due to increased costamere density, resulting in more muscle myofibrils, and therein larger, presumably heavier muscles. However, this finding was only observed in males, and could be attributed to differential acquisition and maintenance of muscle mass based on sex. We identified a potentially novel association between genetic variants in PTK2 and anthropomorphic phenotypes. However, we were unable to confirm the effects of genetic variants on measures of intrinsic muscle strength, namely max grip strength or VO2 max in terms of functional capacity. Further research is needed to confirm this newly identified role for PTK2

    The association of polymorphism rs3736228 within the LRP5 gene with Bone Mineral Density in a Cohort of Caucasian Young Adults

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    INTRODUCTION: Osteoporosis is a significant burden for our aging population. Developing a better understanding of the genetic underpinnings of poor bone quality may assist in the future development of prevention strategies. Correa-Rodriguez et al. have identified a group of single nucleotide polymorphisms (SNPs) that were associated with bone mineral density (BMD) in a population of Spanish Caucasians. In particular, they found that SNP rs3736228 in the low-density lipoprotein receptor related protein 5 (LRP5) gene had an influence on BMD. While the role of LRP5 in the Wnt canonical pathway has been fairly well characterized, its association with phenotypic BMD and osteoporosis has only been explored in a limited fashion. The aim of this study is to expand on this, and to replicate the findings of previous studies in a cohort of healthy young adults. METHODS: Cohort: The University of Calgary cohort from the Assessing Inherited Metabolic Syndrome Markers in the Young (UC AIMMY) study. Participants included consist of 168 healthy, predominantly Caucasian young adults. Phenotypes: height, weight, BMI, and total BMD. Genotyping: Allelic discrimination was determined. Statistical Analysis: After being tested for Hardy-Weinberg equilibrium (HWE), the data was run through analysis of covariance (ANCOVA). RESULTS: Using a dominant model, we found that females with one or more copies of the risk T allele of SNP rs3736228 had a significant negative association with total BMD (p = 0.0347). However, a similar association was not seen in males in this cohort. We did not find a significant association for this polymorphism and height, weight, or BMI. DISCUSSION: Polymorphisms in rs3736228 alter the codon in position 1330, downregulating the LRP5 cell surface receptor function. The LRP5 gene has now been shown in multiple studies to be associated with bone quality measures like calcaneal Qualitative Ultrasound (QUS) and BMD. Our study suggests that SNP rs3736228 also influences BMD in healthy young females. This supports the work of Correa-Rodriguez et al that found that when stratifying by sex, females only showed a trend towards significance (p = 0.092) in QUS measures. SIGNIFICANCE: This study expands our understanding of the importance of LRP5 rs3736228 polymorphisms in BMD by extending its relationship to a cohort of predominantly Caucasian college students. While the development of BMD is polygenic, this work broadened the role of SNP rs3736228 across the age span, and the sexual dimorphism seen in musculoskeletal traits

    Cisplatin +/− rucaparib after preoperative chemotherapy in patients with triple-negative or BRCA mutated breast cancer

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    Patients with triple-negative breast cancer (TNBC) who have residual disease after neoadjuvant therapy have a high risk of recurrence. We tested the impact of DNA-damaging chemotherapy alone or with PARP inhibition in this high-risk population. Patients with TNBC or deleterious BRCA mutation (TNBC/BRCAmut) who had >2 cm of invasive disease in the breast or persistent lymph node (LN) involvement after neoadjuvant therapy were assigned 1:1 to cisplatin alone or with rucaparib. Germline mutations were identified with BROCA analysis. The primary endpoint was 2-year disease-free survival (DFS) with 80% power to detect an HR 0.5. From Feb 2010 to May 2013, 128 patients were enrolled. Median tumor size at surgery was 1.9 cm (0-11.5 cm) with 1 (0-38) involved LN; median Residual Cancer Burden (RCB) score was 2.6. Six patients had known deleterious BRCA1 or BRCA2 mutations at study entry, but BROCA identified deleterious mutations in 22% of patients with available samples. Toxicity was similar in both arms. Despite frequent dose reductions (21% of patients) and delays (43.8% of patients), 73% of patients completed planned cisplatin. Rucaparib exposure was limited with median concentration 275 (82-4694) ng/mL post-infusion on day 3. The addition of rucaparib to cisplatin did not increase 2-year DFS (54.2% cisplatin vs. 64.1% cisplatin + rucaparib; P = 0.29). In the high-risk post preoperative TNBC/BRCAmut setting, the addition of low-dose rucaparib did not improve 2-year DFS or increase the toxicity of cisplatin. Genetic testing was underutilized in this high-risk population

    Using stylized agent-based models for population–environment research: a case study from the Galápagos Islands

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    Agent Based Models (ABMs) are powerful tools for population-environment research but are subject to trade-offs between model complexity and abstraction. This study strikes a compromise between abstract and highly specified ABMs by designing a spatially explicit, stylized ABM and using it to explore policy scenarios in a setting that is facing substantial conservation and development challenges. Specifically, we present an ABM that reflects key Land Use / Land Cover (LULC) dynamics and livelihood decisions on Isabela Island in the Galápagos Archipelago of Ecuador. We implement the model using the NetLogo software platform, a free program that requires relatively little programming experience. The landscape is composed of a satellite-derived distribution of a problematic invasive species (common guava) and a stylized representation of the Galápagos National Park, the community of Puerto Villamil, the agricultural zone, and the marine area. The agent module is based on publicly available data and household interviews, and represents the primary livelihoods of the population in the Galápagos Islands – tourism, fisheries, and agriculture. We use the model to enact hypothetical agricultural subsidy scenarios aimed at controlling invasive guava and assess the resulting population and land cover dynamics. Findings suggest that spatially explicit, stylized ABMs have considerable utility, particularly during preliminary stages of research, as platforms for (1) sharpening conceptualizations of population-environment systems, (2) testing alternative scenarios, and (3) uncovering critical data gaps

    Expressions 1978

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    Expressions contains selected work from some of the Creative Writing Contest winners and honorable mentions along with Commercial Art students at Des Moines Area Community College. Design, topography, and layout was accomplished by Journalism students.https://openspace.dmacc.edu/expressions/1000/thumbnail.jp

    Refining associations between TAS2R38 diplotypes and the 6-n-propylthiouracil (PROP) taste test: findings from the Avon Longitudinal Study of Parents and Children

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    <p>Abstract</p> <p>Background</p> <p>Previous investigations have highlighted the importance of genetic variation in the determination of bitter tasting ability, however have left unaddressed questions as to within group variation in tasting ability or the possibility of genetic prescription of intermediate tasting ability. Our aim was to examine the relationships between bitter tasting ability and variation at the <it>TAS2R38 </it>locus and to assess the role of psychosocial factors in explaining residual, within group, variation in tasting ability.</p> <p>Results</p> <p>In a large sample of children from the Avon Longitudinal Study of Parents and Children, we confirmed an association between bitter compound tasting ability and <it>TAS2R38 </it>variation and found evidence of a genetic association with intermediate tasting ability. Antisocial behaviour, social class and depression showed no consistent relationship with the distribution of taste test scores.</p> <p>Conclusion</p> <p>Factors which could influence a child's chosen taste score, extra to taste receptor variation, appeared not to show relationships with test score. Observed spread in the distribution of the taste test scores <it>within </it>hypothesised taster groups, is likely to be, or at least in part, due to physiological differentiation regulated by other genetic contributors. Results confirm relationships between genetic variation and bitter compound tasting ability in a large sample, and suggest that <it>TAS2R38 </it>variation may also be associated with intermediate tasting ability.</p
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