Biomedical subjects
D Yates
Publications and source records attributed to D Yates.
A fourteenth-century Latin poem on the art of the physician.
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The involvement of noradrenergic nerves in the cardiovascular reflex responses to lower body negative pressure in the anaesthetised rabbit.
1. Resting cardiovascular status and the reflex responses to lower body negative pressure (LBNP) were examined in control rabbits and in rabbits sympathectomised with 6-hydroxydopamine (6-OHDA). 2. Resting systemic arterial pressure and total peripheral resistance were significantly higher in control than in 6-OHDA treated animals. 3. Control animals responded to LBNP at -25 mm Hg with a peripheral vasoconstriction and tachycardia. These responses were absent in 6-OHDA-treated animals. 4. Control animals responded to LBNP at -70 mm Hg with a peripheral vasoconstriction and a bradycardia followed by a tachycardia. There was no significant change in heart rate in response to this stimulus in 6-OHDA-treated animals, although a slight vasoconstriction was seen. 5. Bethanidine blocked the tachycardia and vasoconstriction seen in response to LBNP in control and 6-OHDA-treated rabbits. Under these conditions there was no significant difference between the total peripheral resistance of the control and treated animals. 6. The results indicated that neither the maintenance of the resting systemic arterial pressure nor the reflexes elicited by LBNP in control or in chronically sympathectomised rabbits involved hormonal mechanisms, but LBNP was maintained for 1 min only. These findings are discussed in the context of previous observations.
Quenching of protein fluorescence by transient intermediates in the liver alcohol dehydrogenase reaction.
The addition of saturating concentrations of NAD-+ and alcohol to liver alcohol dehydrogenase in a stopped flow fluorimeter results in a triphasic quenching of enzyme fluorescence. A rapid quenching occurs with a rate constant of 300 to 500 s-minus 1, followed by a slower reaction at 50 to 100 s-minus 1, and ultimately followed by a very slow reaction. The addition of NAD-+ to enzyme in the absence of substrate causes a rapid quenching of enzyme fluorescence at 300 to 500 s-minus 1, with the same amplitude as the rapid phase in the presence of substrate. These studies demonstrate that NAD-+ binding to liver alcohol dehydrogenase causes a conformational change at a rate compatible with the previously reported rate constant for proton release, indicating that proton release is probably coupled to the conformational change.
Proceedings: Cardiovascular responses of the anaesthetized cat to lower body negative pressure.
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Use of imitation in the treatment of dental phobia in early childhood: a preliminary report.
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Syncope and visual hallucinations, apparently from timolol.
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Seroprevalence of human immunodeficiency virus among family practice outpatients.
BACKGROUND: Because the human immunodeficiency virus (HIV) is extremely heterogeneous in its impact on various subpopulations, it is important to carry out HIV seroprevalence studies in different subpopulations using standardized techniques. The present study is the first to report seroprevalence rates of HIV in family medicine outpatient populations. METHODS: To estimate the prevalence and demographic distribution of HIV, 3874 sera samples were collected anonymously at six family medicine clinics in San Bernardino County during a 1-year period. RESULTS: Fifty-nine (1.52 percent) of the sera samples were confirmed HIV-positive. Of the 59 HIV-positive patients, 43 were visiting the clinic for HIV-related reasons. Excluding these 43 cases, and adjusting for age and race using the county population as a standard, the overall rate of HIV infection was 0.45 percent. The 16 HIV-positive patients who visited the clinics for reasons unrelated to HIV were between the ages of 20 and 59 years, with the 30- to 39-year-old age group having the highest prevalence (1.4 percent). Seroprevalence was eight times higher for men than women (chi 2 = 14.3, P = 0.0002), and rates for African-Americans (0.85 percent) were two to three times higher than for Hispanics (0.40 percent) and whites (0.25 percent). CONCLUSIONS: Results of this study are consistent with and support findings from previous surveys of more general populations in the western United States. There are approximately 7800 HIV-infected persons residing in San Bernardino County, and an estimated $796 million will be required to treat these individuals.