Biomedical subjects

L Davidson

Publications and source records attributed to L Davidson.

At least 199 records · Page 11Linked to original sources

PubMedDate not supplied

Circadian rhythms of blood pressure and pressor hormones in normal and hypertensive pregnancy.

1. Circadian patterns of blood pressure and pressor hormones were studied in late pregnancy in ten normotensive women and twenty-one hypertensives. 2. Plasma renin activity, angiotensin II and free adrenaline and noradrenaline leves were highest at 0900 h in normotensives and uncomplicated hypertensives. Catecholamine sulphate levels were lowest at 0900 h. 3. In eight pre-eclamptic hypertensives, plasma renin activity, and angiotensin II were suppressed. 4. Adrenaline sulphate levels were raised in hypertensives. 5. Four pre-eclamptics with noctural hypertension had the highest blood pressures; their diurnal rhythm for noradrenaline sulphate was reversed but they showed no consistent pattern of pressor hormones. However failure of angiotensin II, adrenaline or noradrenaline to fall at night in subjects with increased vascular reactivity could contribute to their nocturnal hypertension.

Adult↗

PubMedDate not supplied

Pressor effect of moderate alcohol consumption in man: a proposed mechanism.

Ingestion of alcohol was associated with a highly significant increase in systolic blood pressure and heart rate which occurred before the blood alcohol reached its peak concentration of 16.9 (s.e.m. = 1.1) mol/1. Drinking non-alcoholic cold liquids caused a marked but transient fall in adrenaline and a rise in noradrenaline concentration. Alcohol prevented this fall in adrenaline and led to a sustained increase in noradrenaline concentration. These changes may be implicated in the elevation of blood pressure associated with alcohol consumption.

Adult↗

PubMedDate not supplied

Plasma noradrenaline and its relationship to plasma oestradiol in normal women during the menstrual cycle.

In order to investigate a possible relationship between sympatho-adrenal neuronal activity and the endocrine changes during the menstrual cycle, free and sulphate-conjugated plasma catecholamines and oestradiol were measured under carefully controlled conditions in 26 normal menstruating women. Plasma oestradiol levels were generally higher during the luteal compared with the follicular phase which corresponded to the self-reported day of the cycle. Free plasma noradrenaline concentration was higher during the luteal phase (P = 0.02) and was positively correlated with plasma oestradiol concentration (r = 0.40, P = 0.023). These relationships were not present for plasma adrenaline. It is conceivable that the higher luteal phase noradrenaline is causally related to the higher oestradiol levels, leading to incomplete inactivation by reducing tissue uptake or competitive inhibition of catechol-O-methyl transferase. As sulphated noradrenaline was not significantly different between the follicular and luteal phases, competitive inhibition of phenolsulphotransferase by oestradiol was considered unlikely.

Adult↗

PubMedDate not supplied

Saccomanno smear slides and Megafunnel slides for sputum specimens. A comparison.

OBJECTIVE: To compare Megafunnel slides to standard Saccomanno smear slides of sputum specimens and evaluate the use of Megafunnel slides for retrospective studies. STUDY DESIGN: Papanicolaou-stained Saccomanno smear and Megafunnel slides (Shandon Lipshaw, Inc., Shandon Inc., Pittsburgh, Pennsylvania, U.S.A.) of 65 clinical sputum specimens from 51 patients were compared for cellular morphology, staining, background and cytologic diagnosis. Recovery of diagnostic cells was quantitated using 10 of these specimens. Megafunnel slides prepared from the clinical sputum samples were immunocytochemically stained. Diagnostic cells were quantitated both before removal from 64 archived Saccomanno smear slides and after placement of these cells onto 238 Megafunnel slides. RESULTS: Saccomanno smear slides and Megafunnel slides of clinical specimens were similar in morphology, background, staining, diagnosis and cell recovery. Megafunnel slides were superior for multiple immunocytochemical stains. The production of multiple Megafunnel slides from archival smear slides provided a method of performing numerous retrospective studies. CONCLUSION: Megafunnel slides compared favorably to Saccomanno smear slides in the quality of specimens but are more expensive and labor intensive to prepare. However, the reduction in screening time by cytotechnologists may be advantageous. Additionally, their potential use for immunocytochemistry, fluorescence in situ hybridization, or other special clinical and research analyses is very promising.

Antibodies↗

PubMedDate not supplied