Texas Medical Center

About: Texas Medical Center is a healthcare organization based out in Houston, Texas, United States. It is known for research contribution in the topics: Population & Cancer. The organization has 2845 authors who have published 2394 publications receiving 79426 citations.

Factors Associated With Left Atrial Remodeling in the General Population.

Abstract: Background— Although contributors to remodeling of the left ventricle (LV) have been well studied in general population cohorts, few data are available describing factors influencing changes in left atrial (LA) structure. Methods and Results— Maximum LA volume was determined by cardiac magnetic resonance imaging among 748 participants in the Dallas Heart Study at 2 visits a mean of 8 years apart. Associations of changes in LA volume (ΔLAV) with traditional risk factors, biomarkers, LV geometry, and remodeling by cardiac magnetic resonance imaging and detailed measurements of global and regional adiposity (by magnetic resonance imaging and dual-energy x ray absorptiometry) were assessed using multivariable linear regression. Greater ΔLAV was independently associated with black and Hispanic race/ethnicity, change in systolic blood pressure, LV mass and ΔLV mass, N-terminal probrain natriuretic peptide and change in N-terminal probrain natriuretic peptide, and body mass index ( P P P =0.21). Associations of ΔLAV with body mass index were explained exclusively by associations with visceral fat mass ( P =0.002), with no association seen between ΔLAV and subcutaneous abdominal fat ( P =0.47) or lower body fat ( P =0.30). Conclusions— Left atrial dilatation in the population is more common in black and Hispanic than in white individuals and is associated with parallel changes in the LV. LA dilatation may be mediated by blood pressure control and the development of visceral adiposity.

Development of mercury hypersensitivity among dental students

Abstract: A study of the rate of mercury hypersensitivity from the prefreshman to the senior class of the University of Texas Dental Branch at Houston is presented. Dental students were patch tested with mercuric chloride and silver amalgam to determine if the rate of hypersensitivity to mercury increased as they were exposed to silver amalgam during their dental training. A statistically significant increase was found in the rate of mercury hypersensitivity from the prefreshman to the senior class. The potential for development of this hypersensitivity presents an added hazard from exposure to mercury in the preparation of silver amalgam.

Dietary Nutrients Involved in One-Carbon Metabolism and Colonic Mucosa-Associated Gut Microbiome in Individuals with an Endoscopically Normal Colon

Abstract: One carbon (1C) metabolism nutrients influence epigenetic regulation and they are supplied by diet and synthesized by gut microbiota. We examined the association between dietary consumption of methyl donors (methionine, betaine and choline) and B vitamins (folate, B2, B6, and B12) and the community composition and structure of the colonic mucosa-associated gut microbiota determined by 16S rRNA gene sequencing in 97 colonic biopsies of 35 men. We used the food frequency questionnaire to assess daily consumption of nutrients, and the UPARSE and SILVA databases for operational taxonomic unit classification. The difference in bacterial diversity and taxonomic relative abundance were compared between low versus high consumption of these nutrients. False discover rate (FDR) adjusted p value < 0.05 indicated statistical significance. The bacterial richness and composition differed significantly by the consumption of folate and B vitamins (p < 0.001). Compared with higher consumption, a lower consumption of these nutrients was associated with a lower abundance of Akkermansia (folate), Roseburia (vitamin B2), and Faecalibacterium (vitamins B2, B6, and B12) but a higher abundance of Erysipelatoclostridium (vitamin B2) (FDR p values < 0.05). The community composition and structure of the colonic bacteria differed significantly by dietary consumption of folate and B vitamins.

Molecular Mechanisms for Transposition of Drug-Resistance Genes and Other Movable Genetic Elements

Abstract: Transposition is proposed to be responsible for the rapid evolution of multiply drug-resistant bacterial strains. Transposons, which carry the genes encoding drug resistance, are linear pieces of DNA that range in size from 2.5 to 23 kilobase pairs and always contain at their ends nucleotide sequences repeated in inverse order. In some transposons the terminal inverted repeat sequences are capable of independent movement and are called insertion sequences. Transposons carry a gene that encodes transposase(s), the enzyme(s) responsible for recombination of the transposon into another DNA molecule. Studies on transposable genetic elements in bacteria have not only given insight into the spread of antibiotic resistance but also into the process of DNA movement.