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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Cardiomyocyte-Specific Deficiency of HSPB1 Worsens Cardiac Dysfunction by Activating NFκB-Mediated Leucocyte Recruitment After Myocardial Infarction

Wang, Yana, Liu, Jiali, Kong, Qiuyue, Cheng, Hao, Tu, Fei, Yu, Peng, Liu, Ying, Zhang, Xiaojin, Li, Chuanfu, Li, Yuehua, Min, Xinxu, Du, Shuya, Ding, Zhengnian, Liu, Li 01 January 2019 (has links)
Aims Inadequate healing after myocardial infarction (MI) leads to heart failure and fatal ventricular rupture, while optimal healing requires timely induction and resolution of inflammation. This study tested the hypothesis that heat shock protein B1 (HSPB1), which limits myocardial inflammation during endotoxemia, modulates wound healing after MI. Methods and results To test this hypothesis, cardiomyocyte-specific HSPB1 knockout (Hspb1-/-) mice were generated using the Cre-LoxP recombination system. MI was induced by ligation of the left anterior descending coronary artery in Hspb1-/- and wild-type (WT) littermates. HSPB1 was up-regulated in cardiomyocytes of WT animals in response to MI, and deficiency of cardiomyocyte HSPB1 increased MI-induced cardiac rupture and mortality within 21 days after MI. Serial echocardiography showed more aggravated remodelling and cardiac dysfunction in Hspb1-/- mice than in WT mice at 1, 3, and 7 days after MI. Decreased collagen deposition and angiogenesis, as well as increased MMP2 and MMP9 activity, were also observed in Hspb1-/- mice compared with WT controls after MI, using immunofluorescence, polarized light microscopy, and zymographic analyses. Notably, Hspb1-/- hearts exhibited enhanced and prolonged leucocyte infiltration, enhanced expression of inflammatory cytokines, and enhanced TLR4/MyD88/NFκB activation compared with WT controls after MI. In-depth molecular analyses in both mice and primary cardiomyocytes demonstrated that cardiomyocyte-specific knockout of HSPB1 increased nuclear factor-κB (NFκB) activation, which promoted the expression of proinflammatory mediators. This led to increased leucocyte recruitment, thereby to excessive inflammation, ultimately resulting in adverse remodelling, cardiac dysfunction, and cardiac rupture following MI. Conclusion These data suggest that HSPB1 acts as a negative regulator of NFκB-mediated leucocyte recruitment and the subsequent inflammation in cardiomyocytes. Cardiomyocyte HSPB1 is required for wound healing after MI and could be a target for myocardial repair in MI patients.
302

Polymorphisms Within RYR3 Gene Are Associated with Risk and Age at Onset of Hypertension, Diabetes, and Alzheimer's Disease

Gong, Shaoqing, Su, Brenda Bin, Tovar, Hugo, Mao, Chunxiang, Gonzalez, Valeria, Liu, Ying, Lu, Yongke, Wang, Ke Sheng, Xu, Chun 11 June 2018 (has links)
Background: Hypertension affects 33% of Americans while type 2 diabetes and Alzheimer's disease (AD) affect 10% of Americans, respectively. Ryanodine receptor 3 gene (RYR3) codes for the RYR which functions to release stored endoplasmic reticulum calcium ions (Ca2+) to increase intracellular Ca2+ concentration. Increasing studies demonstrate that altered levels of intracellular Ca2+ affect cardiac contraction, insulin secretion, and neurodegeneration. In this study, we investigated associations of the RYR3 genetic variants with hypertension, AD, and diabetes. Methods: Family data sets were used to explore association of RYR3 polymorphisms with risk and age at onset (AAO) of hypertension, diabetes, and AD. Results: Family-based association tests using generalized estimating equations (FBAT-GEE) showed several unique or shared disease-1 associated variants in the RYR3 gene. Three single nuclear polymorphisms (SNPs; rs2033610, rs2596164, and rs2278317) are significantly associated with risk for hypertension, diabetes, and AD. Two SNPs (rs4780174 and rs7498093) are significantly associated with AAO of the 3 diseases. Conclusions: RYR3 variants are associated with hypertension, diabetes, and AD. Replication of these results of this gene in these 3 complex traits may help to better understand the genetic basis of calcium-signaling gene, RYR3 in association with risk and AAO of these diseases.
303

ApOE-Independent cis-eSNP on Chromosome 19q13.32 Influences Tau Levels and Late-Onset Alzheimer's Disease Risk

Rao, Shuquan, Ghani, Mahdi, Guo, Zhiyun, Deming, Yuetiva, Wang, Kesheng, Sims, Rebecca, Mao, Canquan, Yao, Yao, Cruchaga, Carlos, Stephan, Dietrich A., Rogaeva, Ekaterina 01 June 2018 (has links)
Although multiple susceptibility loci for late-onset Alzheimer's disease (LOAD) have been identified, a large portion of the genetic risk for this disease remains unexplained. LOAD risk may be associated with single-nucleotide polymorphisms responsible for changes in gene expression (eSNPs). To detect eSNPs associated with LOAD, we integrated data from LOAD genome-wide association studies and expression quantitative trait loci using Sherlock (a Bayesian statistical method). We identified a cis-regulatory eSNP (rs2927438) located on chromosome 19q13.32, for which subsequent analyses confirmed the association with both LOAD risk and the expression level of several nearby genes. Importantly, rs2927438 may represent an APOE-independent LOAD eSNP according to the weak linkage disequilibrium of rs2927438 with the 2 polymorphisms (rs7412 and rs429358) defining the APOE-ε2, -ε3, and -ε4 alleles. Furthermore, rs2927438 does not influence chromatin interaction events at the APOE locus or cis-regulation of APOE expression. Further exploratory analysis revealed that rs2927438 is significantly associated with tau levels in the cerebrospinal fluid. Our findings suggest that rs2927438 may confer APOE-independent risk for LOAD.
304

Principal Component Analysis of Early Alcohol, Drug and Tobacco Use With Major Depressive Disorder in Us Adults

Wang, Kesheng, Liu, Ying, Ouedraogo, Youssoufou, Wang, Nianyang, Xie, Xin, Xu, Chun, Luo, Xingguang 01 May 2018 (has links)
Early alcohol, tobacco and drug use prior to 18 years old are comorbid and correlated. This study included 6239 adults with major depressive disorder (MDD) in the past year and 72,010 controls from the combined data of 2013 and 2014 National Survey on Drug Use and Health (NSDUH). To deal with multicollinearity existing among 17 variables related to early alcohol, tobacco and drug use prior to 18 years old, we used principal component analysis (PCA) to infer PC scores and then use weighted multiple logistic regression analyses to estimate the associations of potential factors and PC scores with MDD. The odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. The overall prevalence of MDD was 6.7%. The first four PCs could explain 57% of the total variance. Weighted multiple logistic regression showed that PC1 (a measure of psychotherapeutic drugs and illicit drugs other than marijuana use), PC2 (a measure of cocaine and hallucinogens), PC3 (a measure of early alcohol, cigarettes, and marijuana use), and PC4 (a measure of cigar, smokeless tobacco use and illicit drugs use) revealed significant associations with MDD (OR = 1.12, 95% CI = 1.08–1.16, OR = 1.08, 95% CI = 1.04–1.12, OR = 1.13, 95% CI = 1.07–1.18, and OR = 1.15, 95% CI = 1.09–1.21, respectively). In conclusion, PCA can be used to reduce the indicators in complex survey data. Early alcohol, tobacco and drug use prior to 18 years old were found to be associated with increased odds of adult MDD.
305

In Silico Preliminary Association of Ammonia Metabolism Genes GLS, CPS1, and GLUL with Risk of Alzheimer’s Disease, Major Depressive Disorder, and Type 2 Diabetes

Griffin, Jeddidiah W.D., Liu, Ying, Bradshaw, Patrick C., Wang, Kesheng 01 March 2018 (has links)
Ammonia is a toxic by-product of protein catabolism and is involved in changes in glutamate metabolism. Therefore, ammonia metabolism genes may link a range of diseases involving glutamate signaling such as Alzheimer’s disease (AD), major depressive disorder (MDD), and type 2 diabetes (T2D). We analyzed data from a National Institute on Aging study with a family-based design to determine if 45 single nucleotide polymorphisms (SNPs) in glutaminase (GLS), carbamoyl phosphate synthetase 1 (CPS1), or glutamate-ammonia ligase (GLUL) genes were associated with AD, MDD, or T2D using PLINK software. HAPLOVIEW software was used to calculate linkage disequilibrium measures for the SNPs. Next, we analyzed the associated variations for potential effects on transcriptional control sites to identify possible functional effects of the SNPs. Of the SNPs that passed the quality control tests, four SNPs in the GLS gene were significantly associated with AD, two SNPs in the GLS gene were associated with T2D, and one SNP in the GLUL gene and three SNPs in the CPS1 gene were associated with MDD before Bonferroni correction. The in silico bioinformatic analysis suggested probable functional roles for six associated SNPs. Glutamate signaling pathways have been implicated in all these diseases, and other studies have detected similar brain pathologies such as cortical thinning in AD, MDD, and T2D. Taken together, these data potentially link GLS with AD, GLS with T2D, and CPS1 and GLUL with MDD and stimulate the generation of testable hypotheses that may help explain the molecular basis of pathologies shared by these disorders.
306

Analysis of Ptprk Polymorphisms in Association With Risk and Age at Onset of Alzheimer's Disease, Cancer Risk, and Cholesterol

Chen, Yang, Xu, Chun, Harirforoosh, Sam, Luo, Xingguang, Wang, Ke Sheng 01 January 2018 (has links)
The human receptor-type protein-tyrosine phosphatase kappa (PTPRK) gene is highly expressed in human brain and was previously associated with an increased risk of neuropsychiatric disorders and cancer. This study investigated the association of 52 single nucleotide polymorphisms (SNPs) in PTPRK with the risk and age at onset (AAO) of Alzheimer's disease (AD) in 791 AD patients and 782 controls. Our data analysis showed that five SNPs (top SNP rs4895829 with p = 0.0125) were associated with the risk of AD based on a multiple logistic regression (p < 0.05); while six SNPs (top SNP rs1891150 with p = 8.02 × 10−6) were associated with AAO by using a multiple linear regression analysis. Interestingly, rs2326681 was associated with both the risk and AAO of AD (p = 4.65 × 10−2 and 5.18 × 10−3, respectively). In a replication study, the results from family-based association test - generalized estimating equation (GEE) statistics and Wilcoxon test showed that seven SNPs were associated with the risk of AD (top SNP rs11756545 with p = 1.02 × 10−2) and 12 SNPs were associated with the AAO (top SNP rs11966128 with p = 1.39 × 10−4), respectively. One additional sample showed that four SNPs were associated with risk of cancer (top SNP rs1339197 with p = 4.1 × 10−3), 12 SNPs associated with LDL-cholesterol (top SNP rs4544930 with p = 3.47 × 10−3), and eight SNPs associated with total cholesterol (top SNP rs1012049 with p = 6.09 × 10−3). In addition, the AD associated rs4895829 was associated with the gene expression level in the cerebellum (p = 7.3 × 10−5). The present study is the first study providing evidence of several genetic variants within the PTPRK gene associated with the risk and AAO of AD, risk of cancer, LDL and total cholesterol levels.
307

Independent Influences of Excessive Body Weight and Elevated Blood Pressure From Childhood on Left Ventricular Geometric Remodeling in Adulthood

Yan, Yinkun, Liu, Junting, Wang, Liang, Hou, Dongqing, Zhao, Xiaoyuan, Cheng, Hong, Mi, Jie 15 September 2017 (has links)
Background Obesity and hypertension are two risk factors of left ventricular hypertrophy (LVH) in adults. We aimed to examine the impacts of body weight and blood pressure (BP) from childhood on adult LV geometric remodeling. Methods The study cohort consisted of 1256 adults aged 27–42 years who had 2–10 measurements of body mass index (BMI) and BP from childhood in 1987 to adulthood in 2010. We calculated the cumulative and incremental values of BMI and BP from childhood to adulthood. In adulthood, four LV geometric patterns were defined based on the values of left ventricular mass index (g/m2.7) and relative wall thickness: normal geometry, concentric remodeling (CR), eccentric hypertrophy (EH) and concentric hypertrophy (CH). Results The prevalence of abnormal LV geometric patterns in adults was 26.4% for CR, 2.0% for EH and 2.5% for CH. For childhood values, systolic BP (Odds Ratio [OR] = 1.26, 95% confidence interval [CI] = 1.08–1.47) but not BMI (OR = 1.06, 95%CI = 0.93-1.18) was associated with adult CR, whereas BMI (OR = 3.53, 95%CI = 2.09–5.98) but not systolic BP (OR = 1.04, 95%CI = 0.65–1.66) was associated with adult EH. Both childhood BMI (OR = 2.69, 95%CI = 1.77–4.09) and systolic BP (OR = 1.64, 95%CI = 1.07–2.51) were independently associated with adult CH. For adulthood, cumulative and incremental values, BMI and systolic BP were independently associated with adult CR, EH and CH. Conclusion Excessive body weight and elevated BP from childhood have independent influences on the development of adult LV geometric remodeling.
308

Family-Based Association Analysis of NAV2 Gene With the Risk and Age at Onset of Alzheimer's Disease

Wang, Ke Sheng, Liu, Ying, Xu, Chun, Liu, Xuefeng, Luo, Xingguang 15 September 2017 (has links)
The neuron navigator 2 (NAV2) gene is highly expressed in brain and involved in the nervous system development and may play a role in Alzheimer's disease (AD). We aimed to investigate the associations of 317 single-nucleotide polymorphisms (SNPs) in the NAV2 gene with the risk and age at onset (AAO) of AD using a family-based sample (1266 AD cases and 1279 healthy relatives). Association with the risk of AD was assessed using family-based association test -generalized estimating equations (FBAT- GEE) statistics while the association with AAO as a quantitative trait was evaluated using the FBAT-Wilcoxon statistic. Single marker analysis showed that 20 SNPs were significantly associated with the risk of AD (top SNP rs7112354 with p = 8.46 × 10− 4) and 11 SNPs were associated with AAO (top SNP rs1354269 with p = 2.87 × 10− 3). Interestingly, two SNPs rs17614100 and rs12364788 were associated with both the risk (p = 1.7 × 10− 2 and 2.71 × 10− 2; respectively) and AAO (p = 1.85 × 10− 3 and 6.06 × 10− 3; respectively). Haplotype analyses further supported the results of single marker analyses. In addition, functional analysis showed that NAV2 mRNA had significant expression across ten human brain regions examined and significantly correlated with APOE expression in four of ten regions. The present study is the first study providing evidence of several genetic variants within the NAV2 gene influencing the risk and AAO of AD.
309

Generalized Linear Mixed Model Analysis of Urban-Rural Differences in Social and Behavioral Factors for Colorectal Cancer Screening

Wang, Ke Sheng, Liu, Xuefeng, Ategbole, Muyiwa, Xie, Xin, Liu, Ying, Xu, Chun, Xie, Changchun, Sha, Zhanxin 01 September 2017 (has links)
Objective: Screening for colorectal cancer (CRC) can reduce disease incidence, morbidity, and mortality. However, few studies have investigated the urban-rural differences in social and behavioral factors influencing CRC screening. The objective of the study was to investigate the potential factors across urban-rural groups on the usage of CRC screening. Methods: A total of 38,505 adults (aged ≥40 years) were selected from the 2009 California Health Interview Survey (CHIS) data - the latest CHIS data on CRC screening. The weighted generalized linear mixed-model (WGLIMM) was used to deal with this hierarchical structure data. Weighted simple and multiple mixed logistic regression analyses in SAS ver. 9.4 were used to obtain the odds ratios (ORs) and their 95% confidence intervals (CIs). Results: The overall prevalence of CRC screening was 48.1% while the prevalence in four residence groups - urban, second city, suburban, and town/rural, were 45.8%, 46.9%, 53.7% and 50.1%, respectively. The results of WGLIMM analysis showed that there was residence effect (p < 0.0001) and residence groups had significant interactions with gender, age group, education level, and employment status (p < 0.05). Multiple logistic regression analysis revealed that age, race, marital status, education level, employment stats, binge drinking, and smoking status were associated with CRC screening (p < 0.05). Stratified by residence regions, age and poverty level showed associations with CRC screening in all four residence groups. Education level was positively associated with CRC screening in second city and suburban. Infrequent binge drinking was associated with CRC screening in urban and suburban; while current smoking was a protective factor in urban and town/rural groups. Conclusions: Mixed models are useful to deal with the clustered survey data. Social factors and behavioral factors (binge drinking and smoking) were associated with CRC screening and the associations were affected by living areas such as urban and rural regions.
310

Mechanobehavioral Scores in Women With and Without TMJ Disc Displacement

Iwasaki, L. R., Gonzalez, Y. M., Liu, Y., Liu, H., Markova, M., Gallo, L. M., Nickel, J. C. 01 July 2017 (has links)
Cartilage fatigue may be a factor in the precocious development of degenerative changes in the temporomandibular joint (TMJ). This cross-sectional study estimated potential for cartilage fatigue via TMJ energy densities (ED) and jaw muscle duty factors (DF), which were combined to calculate mechanobehavioral scores (MBS) in women with (+) and without (-) bilateral TMJ disc displacement (DD). All subjects gave informed consent to participate and were examined using Diagnostic Criteria (DC) for Temporomandibular Disorders (TMD) and magnetic resonance (MR) and computed tomography (CT) images. Forty-seven subjects were categorized into +DD (n = 29) and -DD (n = 18) groups. Dynamic stereometry (MR images combined with jaw-tracking data) characterized individual-specific data of TMJ stress-field mechanics to determine ED (ED = W/Q mJ/mm3, where W = work done, Q = volume of cartilage) during 10 symmetrical jaw-closing cycles with a 20-N mandibular right canine load. Subjects were trained to record masseter and temporalis electromyography over 3 days and 3 nights. Root mean square electromyography/bite-force calibrations determined subject-specific masseter and temporalis muscle activities per 20-N bite-force (T20 N, μV), which defined thresholds. Muscle DF (DF = % duration of muscle activity/total recording time) were determined for a range of thresholds, and MBS (ED2 × DF) were calculated. Intergroup differences in ED, DF, and MBS were assessed via analyses of variance with Bonferroni and Tukey honest significant difference post hoc tests. Average ED for contralateral TMJs was significantly larger (P = 0.012) by 1.4-fold in +DD compared to -DD subjects. Average DF were significantly larger (all P < 0.01) for +DD compared to -DD subjects by 1.7-, 2.5-, and 1.9-fold for day, night, and overall, respectively. Daytime MBS were significantly larger (all P < 0.04) by up to 8.5-fold in +DD compared to -DD subjects. Significantly larger ED, DF, and MBS were shown in women with compared to women without bilateral TMJ DD.

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