Biomedical subjects

Bryant A Stamford

Publications and source records attributed to Bryant A Stamford.

3 recordsLinked to original sources

PubMed2006

Cold exposure and exercise metabolism.

Research regarding the effect of cold exposure on metabolism and substrate utilisation during exercise has produced inconsistent results. Intensity of exercise and training status of subjects are known to impact metabolism and substrate utilisation regardless of environmental conditions. Duration and intensity of cold exposure during exercise also may exert impact. Thus, systematic manipulation of these variables (fitness, intensity of exercise, cold conditions) should provide a means to determine metabolic and substrate utilisation patterns when exercising in the cold. However, a number of variables have been introduced into research methodologies that may confound results. Duration and intensity of cold exposure prior to exercise, and acclimation and clothing status of subjects may confound or override the influence of other variables. Future research addressing the impact of cold exposure on metabolism and substrate utilisation during exercise must attempt to isolate and control each influential factor (prior to and during exercise), and must be alert to the interactive effects that can occur.

Adaptation, Physiological↗

PubMed2004

Acute exposure to environmental tobacco smoke reduces HDL-C and HDL2-C.

BACKGROUND: Chronic environmental tobacco smoke (ETS) exposure increases individuals risk of coronary artery disease by reducing high-density lipoprotein cholesterol (HDL-C). Currently, there is limited research on the acute effects of ETS on HDL-C. This study examined the acute influence of ETS on HDL-C and its subfractions. METHODS: Twelve male subjects (25.7 +/- 3.0 years) were examined to determine the influence of an acute 6-h exposure to ETS on lipid and lipoprotein levels. Baseline blood samples were drawn before ETS exposure from an antecubital vein at 6 am, 2 pm, and 10 pm. The following day, subjects were exposed to 6 h of ETS, approximately 4-10 pm. Blood was again collected at 8, 16 and 24 h following ETS exposure. Blood was assayed for total cholesterol (TC), HDL-C and its subfractions HDL(2)-C and HDL(3)-C. RESULTS: As a result of ETS exposure, HDL-C and HDL(2)-C levels were significantly reduced by 18% and 37%, respectively. This effect was sustained, with a decrease in HDL-C of 13% and HDL2-C of 28% still evident at 24-h post-exposure. TC was unchanged (pre- 187.3 +/- 41.6 and post- 187.0 +/- 46.3); however, there were significant decreases in the TC/HDL-C and HDL2-C/HDL3-C ratios by 16% and 29%, respectively, which were sustained for 24 h. CONCLUSIONS: The findings of this study demonstrate that a 6-h exposure has a negative impact on lipid and lipoprotein profiles and that these levels remained depressed for at least 24 h.

Adult↗

PubMed2004

Anabolic steroid usage in athletics: facts, fiction, and public relations.

Anecdotal evidence suggests the widespread usage of anabolic steroids among athletes (20-90%), particularly at the professional and elite amateur levels. In contrast, scientific studies indicate that usage is rare and no higher than 6%. Conclusions from scientific studies suggest that anabolic steroid usage declines progressively from high school to college and beyond; however, anecdotal evidence claims the opposite trend. In this clash between "hard" scientific data vs. "soft" anecdotal information, it is natural that professionals would gravitate toward scientifically based conclusions. However, in the case of anabolic steroids (a stigmatized and illegal substance), should word-of-mouth testimony from individuals closest to the issues--those who have participated in and coached sports, those who have served as drug-testing overseers, and journalists who relentlessly track leads and verify sources--be set aside as irrelevant? Not if a complete picture is to emerge. In this review, hard scientific evidence is placed on the table side-by-side with soft anecdotal evidence, without weighting or bias. The purpose is to allow the opportunity for each to illuminate the other and, in so doing, potentially bring us a step closer to determining the true extent of anabolic steroid usage in athletics.

Anabolic Agents↗