248 research outputs found

    Association Between Sedentary Behaviors and BMI in US Adolescents: Analysis of the 2015 Youth Risk Behavior Survey

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    ABSTRACT ASSOCIATION BETWEEN SEDENTARY BEHAVIORS AND BMI IN US ADOLESCENTS: ANALYSIS OF THE 2015 YOUTH RISK BEHAVIOR SURVEY By SARAH SADRUDDIN KABANI April 27, 2017 INTRODUCTION: Research has shown a strong link between sedentary behaviors and obesity among adolescents. AIM: This study aims: 1) To determine sedentary behaviors in US high school adolescent nationally 2) To determine the association between sedentary behaviors and BMI after controlling for demographics, recreational behaviors, diet, and physical activity 3) To examine the association between engaging in more than one sedentary behavior and BMI after controlling for demographics, recreational behaviors, diet, and physical activity METHODS: The Youth Risk Behavioral Survey (YRBS) 2015 data was utilized in this study by using weighted percentages to determine the association between sedentary behaviors and BMI while controlling for demographics such as age, sex, race, and grade, recreational behaviors such as smoking and alcohol consumption, diet such as fruit, vegetable, and soda consumption, and physical activity. Univariate logistic regressions and multivariate logistic regressions were conducted to determine the association between sedentary behaviors and BMI. Adjusted and unadjusted odds ratio, 95% confidence intervals, and p-values were calculated. RESULTS: 81.6% of adolescents watched TV during a school day, while 18.4% did not watch TV during a school day. For video games/computer usage/social media (PG) usage, 82.6% engaged in PG usage during a school day, while 17.4% did not engage in PG usage during a school day. When stratifying by BMI, overweight adolescents and obese adolescents have significantly different sex distribution (p=\u3c0.0001), race/ethnicity distribution (p=0.047), TV usage during a school day (p=0.04), PG usage during a school day (p=0.047), and TV & PG usage during a school day (p=\u3c0.02). For TV & PG usage during the school days, adolescents who watch TV and PG, were at higher odds of being obese [AOR =1.3 (1.04, 1.6), p = 0.02] when comparing to adolescents who did not watch TV and PG. DISCUSSION: This study concludes that there is an association between obesity and adolescents who watch TV and use video games/computer/social media during a school day. Sociodemographic factors such as some races, age, and gender are also responsible for obesity among adolescents

    Increased retention of functional fusions to toxic genes in new two-hybrid libraries of the E. coli strain MG1655 and B. subtilis strain 168 genomes, prepared without passaging through E. coli

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    BACKGROUND: Cloning of genes in expression libraries, such as the yeast two-hybrid system (Y2H), is based on the assumption that the loss of target genes is minimal, or at worst, managable. However, the expression of genes or gene fragments that are capable of interacting with E. coli or yeast gene products in these systems has been shown to be growth inhibitory, and therefore these clones are underrepresented (or completely lost) in the amplified library. RESULTS: Analysis of candidate genes as Y2H fusion constructs has shown that, while stable in E. coli and yeast for genetic studies, they are rapidly lost in growth conditions for genomic libraries. This includes the rapid loss of a fragment of the E. coli cell division gene ftsZ which encodes the binding site for ZipA and FtsA. Expression of this clone causes slower growth in E. coli. This clone is also rapidly lost in yeast, when expressed from a GAL1 promoter, relative to a vector control, but is stable when the promoter is repressed. We have demonstrated in this report that the construction of libraries for the E. coli and B. subtilis genomes without passaging through E. coli is practical, but the number of transformants is less than for libraries cloned using E. coli as a host. Analysis of several clones in the libraries that are strongly growth inhibitory in E. coli include genes for many essential cellular processes, such as transcription, translation, cell division, and transport. CONCLUSION: Expression of Y2H clones capable of interacting with E. coli and yeast targets are rapidly lost, causing a loss of complexity. The strategy for preparing Y2H libraries described here allows the retention of genes that are toxic when inappropriately expressed in E. coli, or yeast, including many genes that represent potential antibacterial targets. While these methods are generally applicable to the generation of Y2H libraries from any source, including mammalian and plant genomes, the potential of functional clones interacting with host proteins to inhibit growth would make this approach most relevant for the study of prokaryotic genomes

    Function of SSA Subfamily of Hsp70 Within and Across Species Varies Widely in Complementing Saccharomyces cerevisiae Cell Growth and Prion Propagation

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    BACKGROUND:The cytosol of most eukaryotic cells contains multiple highly conserved Hsp70 orthologs that differ mainly by their spatio-temporal expression patterns. Hsp70s play essential roles in protein folding, transport or degradation, and are major players of cellular quality control processes. However, while several reports suggest that specialized functions of Hsp70 orthologs were selected through evolution, few studies addressed systematically this issue. METHODOLOGY/PRINCIPAL FINDINGS:We compared the ability of Ssa1p-Ssa4p from Saccharomyces cerevisiae and Ssa5p-Ssa8p from the evolutionary distant yeast Yarrowia lipolytica to perform Hsp70-dependent tasks when expressed as the sole Hsp70 for S. cerevisiae in vivo. We show that Hsp70 isoforms (i) supported yeast viability yet with markedly different growth rates, (ii) influenced the propagation and stability of the [PSI(+)] and [URE3] prions, but iii) did not significantly affect the proteasomal degradation rate of CFTR. Additionally, we show that individual Hsp70 orthologs did not induce the formation of different prion strains, but rather influenced the aggregation properties of Sup35 in vivo. Finally, we show that [URE3] curing by the overexpression of Ydj1p is Hsp70-isoform dependent. CONCLUSION/SIGNIFICANCE:Despite very high homology and overlapping functions, the different Hsp70 orthologs have evolved to possess distinct activities that are required to cope with different types of substrates or stress situations. Yeast prions provide a very sensitive model to uncover this functional specialization and to explore the intricate network of chaperone/co-chaperone/substrates interactions

    Spatial and Functional Distribution of MYBPC3 Pathogenic Variants and Clinical Outcomes in Patients with Hypertrophic Cardiomyopathy

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    Background - Pathogenic variants in MYBPC3, encoding cardiac MyBP-C, are the most common cause of familial hypertrophic cardiomyopathy. A large number of unique MYBPC3 variants and relatively small genotyped HCM cohorts have precluded detailed genotype-phenotype correlations. Methods - Patients with HCM and MYBPC3 variants were identified from the Sarcomeric Human Cardiomyopathy Registry (SHaRe). Variant types and locations were analyzed, morphologic severity was assessed, and time-event analysis was performed (composite clinical outcome of sudden death, class III/IV heart failure, LVAD/transplant, atrial fibrillation). For selected missense variants falling in enriched domains, myofilament localization and degradation rates were measured in vitro. Results - Among 4,756 genotyped HCM patients in SHaRe, 1,316 patients were identified with adjudicated pathogenic truncating (N=234 unique variants, 1047 patients) or non-truncating (N=22 unique variants, 191 patients) variants in MYBPC3. Truncating variants were evenly dispersed throughout the gene, and hypertrophy severity and outcomes were not associated with variant location (grouped by 5' - 3' quartiles or by founder variant subgroup). Non-truncating pathogenic variants clustered in the C3, C6, and C10 domains (18 of 22, 82%, p<0.001 vs. gnomAD common variants) and were associated with similar hypertrophy severity and adverse event rates as observed with truncating variants. MyBP-C with variants in the C3, C6, and C10 domains was expressed in rat ventricular myocytes. C10 mutant MyBP-C failed to incorporate into myofilaments and degradation rates were accelerated by ~90%, while C3 and C6 mutant MyBP-C incorporated normally with degradation rate similar to wild-type. Conclusions - Truncating variants account for 91% of MYBPC3 pathogenic variants and cause similar clinical severity and outcomes regardless of location, consistent with locus-independent loss-of-function. Non-truncating MYBPC3 pathogenic variants are regionally clustered, and a subset also cause loss-of-function through failure of myofilament incorporation and rapid degradation. Cardiac morphology and clinical outcomes are similar in patients with truncating vs. non-truncating variants

    Conventional and molecular epidemiology of Tuberculosis in Manitoba

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    BACKGROUND: To describe the demographic and geographic distribution of tuberculosis (TB) in Manitoba, thus determining risk factors associated with clustering and higher incidence rates in distinct subpopulations. METHODS: Data from the Manitoba TB Registry was compiled to generate a database on 855 patients with tuberculosis and their contacts from 1992–1999. Recovered isolates of M. tuberculosis were typed by IS6110 restriction fragment length polymorphisms. Bivariate and multivariate logistic regression models were used to identify risk factors involved in clustering. RESULTS: A trend to clustering was observed among the Canadian-born treaty Aboriginal subgroup in contrast to the foreign-born. The dominant type, designated fingerprint type 1, accounts for 25.8% of total cases and 75.3% of treaty Aboriginal cases. Among type 1 patients residing in urban areas, 98.9% lived in Winnipeg. In rural areas, 92.8% lived on Aboriginal reserves. Statistical models revealed that significant risk factors for acquiring clustered tuberculosis are gender, age, ethnic origin and residence. Those at increased risk are: males (p < 0.05); those under age 65 (p < 0.01 for each age subgroup); treaty Aboriginals (p < 0.001), and those living on reserve land (p < 0.001). CONCLUSION: Molecular typing of isolates in conjunction with contact tracing data supports the notion of the largest ongoing transmission of a single strain of TB within the treaty-status population of Canada recorded to date. This data demonstrates the necessity of continued surveillance of countries with low prevalence of the disease in order to determine and target high-risk populations for concentrated prevention and control measures

    Intergenerational Transmission of Glucose Intolerance and Obesity by In Utero Undernutrition in Mice

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    OBJECTIVE—Low birth weight (LBW) is associated with increased risk of obesity, diabetes, and cardiovascular disease during adult life. Moreover, this programmed disease risk can progress to subsequent generations. We previously described a mouse model of LBW, produced by maternal caloric undernutrition (UN) during late gestation. LBW offspring (F1-UN generation) develop progressive obesity and impaired glucose tolerance (IGT) with aging. We aimed to determine whether such metabolic phenotypes can be transmitted to subsequent generations in an experimental model, even in the absence of altered nutrition during the second pregnancy

    Hsp70 chaperones: Cellular functions and molecular mechanism

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    Hsp70 proteins are central components of the cellular network of molecular chaperones and folding catalysts. They assist a large variety of protein folding processes in the cell by transient association of their substrate binding domain with short hydrophobic peptide segments within their substrate proteins. The substrate binding and release cycle is driven by the switching of Hsp70 between the low-affinity ATP bound state and the high-affinity ADP bound state. Thus, ATP binding and hydrolysis are essential in vitro and in vivo for the chaperone activity of Hsp70 proteins. This ATPase cycle is controlled by co-chaperones of the family of J-domain proteins, which target Hsp70s to their substrates, and by nucleotide exchange factors, which determine the lifetime of the Hsp70-substrate complex. Additional co-chaperones fine-tune this chaperone cycle. For specific tasks the Hsp70 cycle is coupled to the action of other chaperones, such as Hsp90 and Hsp100

    Hierarchical Anatomical Brain Networks for MCI Prediction: Revisiting Volumetric Measures

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    Owning to its clinical accessibility, T1-weighted MRI (Magnetic Resonance Imaging) has been extensively studied in the past decades for prediction of Alzheimer's disease (AD) and mild cognitive impairment (MCI). The volumes of gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF) are the most commonly used measurements, resulting in many successful applications. It has been widely observed that disease-induced structural changes may not occur at isolated spots, but in several inter-related regions. Therefore, for better characterization of brain pathology, we propose in this paper a means to extract inter-regional correlation based features from local volumetric measurements. Specifically, our approach involves constructing an anatomical brain network for each subject, with each node representing a Region of Interest (ROI) and each edge representing Pearson correlation of tissue volumetric measurements between ROI pairs. As second order volumetric measurements, network features are more descriptive but also more sensitive to noise. To overcome this limitation, a hierarchy of ROIs is used to suppress noise at different scales. Pairwise interactions are considered not only for ROIs with the same scale in the same layer of the hierarchy, but also for ROIs across different scales in different layers. To address the high dimensionality problem resulting from the large number of network features, a supervised dimensionality reduction method is further employed to embed a selected subset of features into a low dimensional feature space, while at the same time preserving discriminative information. We demonstrate with experimental results the efficacy of this embedding strategy in comparison with some other commonly used approaches. In addition, although the proposed method can be easily generalized to incorporate other metrics of regional similarities, the benefits of using Pearson correlation in our application are reinforced by the experimental results. Without requiring new sources of information, our proposed approach improves the accuracy of MCI prediction from (of conventional volumetric features) to (of hierarchical network features), evaluated using data sets randomly drawn from the ADNI (Alzheimer's Disease Neuroimaging Initiative) dataset

    Dia2 Controls Transcription by Mediating Assembly of the RSC Complex

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    Background: Dia2 is an F-box protein found in the budding yeast, S. cerevisiae. Together with Skp1 and Cul1, Dia2 forms the substrate-determining part of an E3 ubiquitin ligase complex, otherwise known as the SCF. Dia2 has previously been implicated in the control of replication and genome stability via its interaction with the replisome progression complex. Principal Findings: We identified components of the RSC chromatin remodelling complex as genetic interactors with Dia2, suggesting an additional role for Dia2 in the regulation of transcription. We show that Dia2 is involved in controlling assembly of the RSC complex. RSC belongs to a group of ATP-dependent nucleosome-remodelling complexes that controls the repositioning of nucleosomes. The RSC complex is expressed abundantly and its 17 subunits are recruited to chromatin in response to both transcription activation and repression. In the absence of Dia2, RSC-mediated transcription regulation was impaired, with concomitant abnormalities in nucleosome positioning. Conclusions: Our findings imply that Dia2 is required for the correct assembly and function of the RSC complex. Dia2, by controlling the RSC chromatin remodeller, fine-tunes transcription by controlling nucleosome positioning during transcriptional activation and repression

    Transcriptomes of <i>Trypanosoma brucei</i> rhodesiense from sleeping sickness patients, rodents and culture:Effects of strain, growth conditions and RNA preparation methods

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    All of our current knowledge of African trypanosome metabolism is based on results from trypanosomes grown in culture or in rodents. Drugs against sleeping sickness must however treat trypanosomes in humans. We here compare the transcriptomes of Trypanosoma brucei rhodesiense from the blood and cerebrospinal fluid of human patients with those of trypanosomes from culture and rodents. The data were aligned and analysed using new user-friendly applications designed for Kinetoplastid RNA-Seq data. The transcriptomes of trypanosomes from human blood and cerebrospinal fluid did not predict major metabolic differences that might affect drug susceptibility. Usefully, there were relatively few differences between the transcriptomes of trypanosomes from patients and those of similar trypanosomes grown in rats. Transcriptomes of monomorphic laboratory-adapted parasites grown in in vitro culture closely resembled those of the human parasites, but some differences were seen. In poly(A)-selected mRNA transcriptomes, mRNAs encoding some protein kinases and RNA-binding proteins were under-represented relative to mRNA that had not been poly(A) selected; further investigation revealed that the selection tends to result in loss of longer mRNAs
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