University of Texas Medical Branch

About: University of Texas Medical Branch is a education organization based out in Galveston, Texas, United States. It is known for research contribution in the topics: Population & Virus. The organization has 22033 authors who have published 38268 publications receiving 1517502 citations. The organization is also known as: The University of Texas Medical Branch at Galveston & UTMB.

Regulation of mitochondrial bioenergetic function by hydrogen sulfide. Part I. Biochemical and physiological mechanisms

Abstract: Until recently, hydrogen sulfide (H2S) was exclusively viewed a toxic gas and an environmental hazard, with its toxicity primarily attributed to the inhibition of mitochondrial Complex IV, resulting in a shutdown of mitochondrial electron transport and cellular ATP generation. Work over the last decade established multiple biological regulatory roles of H2S, as an endogenous gaseous transmitter. H2S is produced by cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). In striking contrast to its inhibitory effect on Complex IV, recent studies showed that at lower concentrations, H2S serves as a stimulator of electron transport in mammalian cells, by acting as a mitochondrial electron donor. Endogenous H2S, produced by mitochondrially localized 3-MST, supports basal, physiological cellular bioenergetic functions; the activity of this metabolic support declines with physiological aging. In specialized conditions (calcium overload in vascular smooth muscle, colon cancer cells), CSE and CBS can also associate with the mitochondria; H2S produced by these enzymes, serves as an endogenous stimulator of cellular bioenergetics. The current article overviews the biochemical mechanisms underlying the stimulatory and inhibitory effects of H2S on mitochondrial function and cellular bioenergetics and discusses the implication of these processes for normal cellular physiology. The relevance of H2S biology is also discussed in the context of colonic epithelial cell physiology: colonocytes are exposed to high levels of sulfide produced by enteric bacteria, and serve as a metabolic barrier to limit their entry into the mammalian host, while, at the same time, utilizing it as a metabolic ‘fuel’. Linked Articles This article is part of a themed issue on Mitochondrial Pharmacology: Energy, Injury & Beyond. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2014.171.issue-8

A trial of 17 alpha-hydroxyprogesterone caproate to prevent prematurity in twins.

Abstract: Background In singleton gestations, 17 alpha-hydroxyprogesterone caproate (17P) has been shown to reduce the rate of recurrent preterm birth. This study was undertaken to evaluate whether 17P would reduce the rate of preterm birth in twin gestations. Methods We performed a randomized, double-blind, placebo-controlled trial in 14 centers. Healthy women with twin gestations were assigned to weekly intramuscular injections of 250 mg of 17P or matching placebo, starting at 16 to 20 weeks of gestation and ending at 35 weeks. The primary study outcome was delivery or fetal death before 35 weeks of gestation. Results Six hundred sixty-one women were randomly assigned to treatment. Baseline demographic data were similar in the two study groups. Six women were lost to follow-up; data from 655 were analyzed (325 in the 17P group and 330 in the placebo group). Delivery or fetal death before 35 weeks occurred in 41.5% of pregnancies in the 17P group and 37.3% of those in the placebo group (relative risk, 1.1; 95% con...

Health-related quality of life in chronic disorders: a comparison across studies using the MOS SF-36.

Abstract: The purpose of this report is to examine health-related quality of life (HRQoL) as measured by the Medical Outcomes Study Short Form-36, across patient populations with chronic disorders and to compare quality of life (QoL) in these subjects with normative data on healthy persons. Six studies, within the Center for Research in Chronic Disorders at the University of Pittsburgh School of Nursing, in patients with urinary incontinence, prostate cancer, chronic obstructive pulmonary disease (COPD), acquired immune deficiency syndrome (AIDS), fibromyalgia and hyperlipidaemia provided the data for analysis. The results demonstrated that not only did the prostate cancer and hyperlipidaemia patients have the highest QoL across the chronic disorders, but their QoL was comparable to normative data on healthy persons. Homebound, elderly, incontinent patients had the lowest QoL for physical functioning, whereas patients hospitalized with AIDS had the lowest QoL in general health and social functioning. Patients with COPD had the lowest QoL in role-physical, role-emotional and mental health. Patients with fibromyalgia had the lowest QoL in bodily pain and vitality. Compared to normative data, patients with urinary incontinence, COPD, AIDS and fibromyalgia generally had lower QoL. Prostate cancer and hyperlipidaemia patients had QoL comparable to normative data. Compared to normative data, patients with urinary incontinence, COPD, AIDS and fibromyalgia had more variability for role-emotional. AIDS patients had more variability on physical functioning, bodily pain and social functioning compared to the normative data. These data suggest that patients with various chronic disorders may have QoL that is lower in most domains compared to a healthy population. However, there may be differences in the domains affected as well as the extent of variation across specific chronic disorders.

A Mechanism for the Amelioration by Hyperbaric Oxygen of Experimental Staphylococcal Osteomyelitis in Rabbits

Abstract: Although hyperbaric oxygen (HBO) is as effective as cephalothin against osteomyelitis due to Staphylococcus aureus in the rabbit, the effect is not by directing killing. To investigate the mechanism, argon washouts (perfusion) and oxygen tensions were measured by intramedullary probes placed in the metaphyses of infected and uninfected tibias. In vitro phagocytic killing activity for S. aureus was determined at oxygen tensions found in these bones under ambient and HBO conditions. Mean tibial oxygen tensions (mm Hg) under ambient conditions were 21 (infected) and 45 (uninfected); under HBO conditions, 104 (infected) and 321 (uninfected). Perfusion was decreased in osteomyelitic bone and was not acutely increased by HBO in either normal or infected bone. Phagocytic killing of S. aureus was markedly decreased at 23 mm Hg of O2, significantly improved at 45 and 109 mm Hg, and most effective at 150 mm Hg. Thus, in osteomyelitic bone, HBO increased intramedullary oxygen to tensions consistent with normal phagocytic function.