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Biomedical subjects

Christopher Womack

Publications and source records attributed to Christopher Womack.

10 recordsLinked to original sources
PubMed2007

Effects of a maximal exercise test on neurocognitive function.

OBJECTIVE: To examine the effects of a maximal exercise test on cognitive function in recreational athletes. DESIGN: A repeated-measures design was used to compare baseline with post-cognitive function and fatigue symptoms after a maximal exercise test. SETTING: Division 1 American Midwestern University, (Michigan State University, Michigan, USA). PARTICIPANTS: 102 male and female recreational athletes. INTERVENTION: Participants in the experimental group (n = 54) were asked to perform a maximal treadmill exercise test to maximal oxygen uptake (VO2 max). Participants in the control group were asked to rest for 15 min. MAIN OUTCOME MEASUREMENTS: All participants were administered a neuropsychological test battery called Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) before and after exercise to measure neurocognitive function and fatigue symptoms. RESULTS: Results revealed a significant group (control, experimental) x time (baseline, post-test 1, post-test 2) interaction for verbal memory composite scores (p = 0.025). Specifically, verbal memory composite scores decreased in the experimental group from baseline to post-test 1 (p = 0.00). These values returned to baseline 3 days after the VO2 max test (p = 0.00). Further analysis on verbal memory composite scores demonstrated significant differences on immediate recall memory (p = 0.00) and delayed recall memory (p = 0.00). No significant differences were observed for visual memory (p = 0.54), motor processing speed (p = 0.68) and reaction time (p = 0.44) composite scores between the experimental and control groups. CONCLUSION: The results of this study suggest that a maximal exercise test attenuated a limiting effect on cognitive function. When utilising a neuropsychological test battery to evaluate a patient who has sustained a head injury, the test should not be administered immediately after a practice or a game session.

Cognition↗
PubMed2006

Supply and use of human tissue for research purposes: survey of BATB affiliated tissue banks.

This paper describes a survey undertaken to identify the extent of supply and use of human tissue in research by BATB affiliated tissue banks. Approximately one third of tissue banks registered with the BATB are currently supplying samples that are found to be unsuitable for clinical use, for research. These banks all obtain consent for research and all supply tissue for in-house research. Some tissue is transferred to other public and commercial institutions. A harmonised network approach is proposed as the way forward to meet the increasing demand for human tissue in research.

Biomedical Research↗
PubMed2006

Cadaveric tissue retrieval service for research: one-year review and options for the future.

The Tissue Acquisition Unit at Peterborough has an established service for collecting cadaveric human tissue for research. A one-year, on-going, in-house review was undertaken to evaluate the cost- and time-effectiveness of the service. The review identified referrals that failed to result in post mortem tissue retrieval. Only 28.6% of potential donors referred to the Unit led to successful tissue retrieval and the main reason for failure was post mortem time delay in some cases related to distance of location of the body from the Unit. The evolving novel role of the Pathology Liaison Nurses in the Unit is expected to increase the proportion of tissue acquisition from the local population and provide a more efficient service for donors and their families and researchers who use human tissue.

Biomedical Research↗
PubMed2005

Challenges in the testing of non-heart-beating cadavers for viral markers: implications for the safety of tissue donors.

Natural changes that occur in blood and tissue after death may result in false positive results in antigen and antibody detection tests performed to identify markers of viral infection in potential tissue donors. Such tissue, which might otherwise be acceptable for therapeutic purposes, would not meet current standards for safe tissue banking. This is especially important in the context of insufficiency in the tissue supply. In this study, a series of blood samples collected during routine post-mortem examination was assayed using a range of commercially available kits for the detection of HBsAg, anti-HCV and anti-HIV 1 + 2 antibody/antigen. Results of tests on 104 samples collected from 97 individuals indicate that some kits result in a higher number of initial reactive samples than others. Approximately 40% of samples were reactive in one or more HBsAg assay, less than 10% in at least one anti-HIV kit and only 1 sample at low level on an anti-HCV kit. Liver or lymph node samples from individuals whose serum sample gave reactive results in antigen/antibody assays were tested for viral nucleic acid in the corresponding nucleic acid amplification test. Only one individual's sample was confirmed to test positive for HBsAg in a confirmatory neutralisation test and by nucleic acid amplification technology, and a second individual whose serum was scored reactive for anti-HCV, but negative for HBsAg, had a liver sample which was HBV DNA positive and HCV RNA negative. The results of the study indicate that antibody/antigen assays are not as specific as NAT using state of the art DNA extraction techniques. Both types of assay complement each other and used together will help assure the safety of tissues for transplantation.

Biomarkers↗
PubMed2002

The research potential of tissue from a cadaveric donor.

The purpose of this case report is to illustrate the research potential of the tissue obtained from a single donor referred to the Peterborough Hospitals NHS Trust (PHNHST) Research Tissue Bank. Tissue retrieval was done 19 hours after death and 453 tissue units processed on site were despatched to 20 mainly commercial client research organisations.

Journal Article↗
PubMed2002

Ethical issues relating to supply of human tissue to the commercial biomedical sector.

Demand for an ethical supply of human tissue for research in the commercial biomedical sector is increasing substantially. This article sets out to review ethical issues specifically relating to acquisition of tissue from patients in a publicly funded national health service (NHS), for research use in a commercial setting. Some of the background to recent high profile Inquiries in England is discussed and is used to illustrate legal and ethical differences between living and dead people. Issues relating to patient consent are investigated and the case is made for a clear distinction between tissue acquisition and tissue processing. Future possibilities for regulation are discussed.

Journal Article↗
PubMed2002

Metabolic acidosis in rats increases intestinal NHE2 and NHE3 expression and function.

Chronic metabolic acidosis increases intestinal Na absorption, although through undefined mechanisms. Whether this occurs through enhanced expression and/or function of the brush-border Na+/H+ exchangers (NHE)2 and NHE3 is unknown. Metabolic acidosis was induced in rats by feeding ammonium chloride through their drinking water. Intestinal NHE activities were measured using brush-border 22Na+ uptake. Western and Northern blots measured changes in protein and mRNA expression, respectively. Acidosis occurred within 2 days of ammonium chloride feedings but increased after 6 days. NHE2 and NHE3 activities, protein expression, and mRNA levels increased in acidotic rats compared with controls. In contrast, basolateral NHE1 expression was not affected. Brush-border alkaline phosphatase showed no effect of metabolic acidosis on cellular differentiation. This study demonstrated a direct effect of metabolic acidosis on NHE2 and NHE3 activity, expression, and gene transcription. Metabolic acidosis is one of the few circumstances shown to affect NHE2 function and expression, thus providing insights into the role of NHE2 on intestinal physiology.

Acidosis↗