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Biomedical subjects

W J Jaspers

Publications and source records attributed to W J Jaspers.

3 recordsLinked to original sources

Autonomic heart-rate control in response to standing in toxemic and normotensive primigravid pregnancies.

Heart-rate changes after transition from a supine to a standing posture were measured in 12 hypertensive and 12 normotensive primigravid women, in their last trimester of gestation. The subjects beat-to-beat heart-rate (HR) changes were recorded on both an ordinary cardiotocograph and on magnetic tape. The hypertensive patient group (1) reached an HR-maximum after standing up in a significantly shorter period of time and (2) had a significantly lower HR during 1 min erect posture. A population threatened by pregnancy-induced hypertension might be detected by using the non-invasive method of recording the maternal beat-to-beat heart-rate changes after transition to the standing posture, even before the onset of hypertension.

Adult

Decrease of angiotensin sensitivity after bed rest and strongly sodium-restricted diet in pregnancy.

Angiotensin II (A-II) sensitivity was determined in 23 nonmedicated nulliparas in the third trimester of pregnancy, before and after a 7- to 10-day period of bed rest and a strongly sodium-restricted diet (maximal 20 mmol Na+/24 hr). Seventeen nulliparous women had pregnancy-induced hypertension (PIH). The effective pressor dose (EPD), that is the minimal amount of A-II necessary for a 20 mm Hg elevation of the diastolic blood pressure, rose from a mean of 11.0 +/- 5.0 to 17.9 +/- 5.7 ng/kg/min. This is an increase of the mean of 63%. Six women were normotensive during the course of the pregnancy. They showed an increase of EPD from 12.6 +/- 4.9 to 28.3 +/- 10.9 ng/kg/min after sodium restriction and bed rest. This is a mean increase of 124%. It is concluded from this study that sodium not only is important in volume regulation but also seems to play a role in vessel wall reactivity. This effect of sodium on vascular reactivity could be the explanation for the favorable effect of a strongly sodium-restricted diet in lowering the incidence of eclampsia in women with PIH.

Adult

Angiotensin-II sensitivity and prostaglandin-synthetase inhibition in pregnancy.

Angiotensin-II sensitivity was measured with a standardized test in 8 healthy nonpregnant females and in 14 healthy primigravid women. In the primigravid women the effective pressor dose (EPD), i.e. the minimal dose of angiotensin-II (A-II) necessary for a rise in diastolic blood pressure of 20 mm Hg, was 17.1 +/- 5.7. This is significantly higher than the EPD in the control group (5.2 +/- 1.2). The pregnant patients were also tested 75 min after a 50 mg indomethacine suppository, which produced a decrease of the EPD of 9.5 +/- 3.0, a fall of 44%. None of the 7 patients tested between 28 and 32 wk of gestation developed pregnancy-induced hypertension. They all had a normal EPD. It may be concluded that (1) A-II sensitivity is decreased in pregnancy, and (2) vascular reactivity in pregnancy is at least in part mediated by prostaglandins.

Adolescent