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Biomedical subjects

D L Vesley

Publications and source records attributed to D L Vesley.

2 recordsLinked to original sources

Respiratory protection devices.

OSHA authority and responsibility have led to the requirement that health care workers potentially exposed to patients with active tuberculosis in situations where engineering controls are not feasible for protection must utilize personal protective equipment at least equivalent to HEPA respirators. ICPs generally believe that this approach is unnecessarily conservative and imposes undue burdens on patient care. The arguments on both sides of this controversy have some merit. Reported cases of tuberculosis and skin-test conversions among health care workers since 1988 and the absence of a demonstrated safe level of exposure have led many to the conclusion that HEPA respirators are justified. On the other side, tuberculosis currently is not a major problem in some areas of the country, and many believe that less stringent personal protective devices (e.g., DM respirators) may provide protection equivalent to HEPA filters--at least in terms of preventing infection if not in terms of filtration efficiency. They believe that the lesser discomfort and lower cost associated with DM respirators justify the argument for a more flexible standard. Perhaps additional research can help to resolve the remaining controversy. Definitive answers are unlikely to surface quickly, however, and it is likely that the controversy and confusion will continue for at least awhile longer.

Health Personnel↗

Atrial natriuretic peptide fragments in dogs with experimental heart failure.

1. This study in the canine arteriovenous (AV) fistula model of high-output heart failure (HOHF) evaluated the chronic temporal changes in plasma ANF and pro ANF 31-67 and their relationship to body-fluid balance and the renin-aldosterone axis. In addition, the haemodynamic, hormonal and renal excretory effects of synthetic pro ANF 31-67 infusions were examined in normal and AV fistula dogs with compensated HOHF. 2. Following the construction of the AV fistula, the dogs exhibited chronic parallel elevations in right atrial pressure and the plasma concentrations of ANF and pro ANF 31-67. The gradual increases in the two peptides were associated with a gradual decrease in plasma renin activity and the re-establishment of sodium balance. 3. In normal and compensated AV fistula dogs, synthetic pro ANF 31-67 produced similar significant reductions in arterial blood pressure, right atrial pressure and elevations in urinary sodium excretion. These effects were not associated with increases in plasma or urinary cyclic GMP (cGMP). 4. These results suggest that the elevation in the endogenous circulating levels of pro ANF 31-67 in the AV fistula dogs may represent one chronic adaptive mechanism to achieve body fluid homeostasis. Furthermore, via potentially different mechanisms of action, ANF and pro ANF 31-67 may coordinate and contribute to the regulation of haemodynamic and renal function during physiological and pathophysiological situations.

Animals↗