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Biomedical subjects

J Bonnar

Publications and source records attributed to J Bonnar.

At least 37 records · Page 2Linked to original sources
PubMed1978

HLA antigens in severe pre-eclampsia.

When the HLA types of 80 pre-eclamptic women and their husbands and 83 control couples were compared significantly more pre-eclamptic women had only one identifiable HLA B antigen, and were presumed to be homozygous at this locus. Those who were homozygous for HLA B were more likely to be homozygous for HLA A as well, and more likely to be homozygous for HLA A as well, and to have more severe pre-eclampsia. There was neither increased HLA incompatibility nor greater antigen-sharing between pre-eclamptic women and their husbands, but maternal HLA A and B homozygosity reduced the number of antigenic disparities between pre-eclamptic women and their husbands. The data are consistent with the hypothesis that maternal recessive immune-response genes may contribute to the development of pre-eclampsia. Alternatively maternal HLA homozygosity may predispose to fetal changes comparable to runting.

Epitopes↗
PubMed1978

Fibrinolysis in decidual spiral arteries in late pregnancy.

The fibrinolytic activity of the intimal cells of decidual spiral arteries and the syncytium of placental villi was studied by electron microscopy in ten normal full-term human pregnancies using a modification of the fibrin slide technique. Endothelial cells lining the intima of the decidual spiral arteries showed a considerably greater fibrinolytic activity than intimal cytotrophoblast and the syncytiotrophoblast showed no activity. The replacement of endothelial cells by an intimal lining of cytotrophoblast, and the presence of cytotrophoblast in the media, appears to play an important role in the reduction of the fibrinolytic activity of the vessel. This inhibition of fibrinolytic activity in the utero-placental arteries may be the physiological mechanism which controls fibrin deposition in these vessels and on the placental villi.

Arteries↗
PubMed1978

Early platelet consumption in pre-eclampsia.

One hundred and thirty-one women with chronic hypertension were studied serially during pregnancy to determine the sequence of events in the development of superimposed pre-eclampsia and to discover the time of onset. Twenty-seven women developed a sustained rise in plasma urate concentrations, which began at about 28 weeks' gestation and which is characteristic of pre-eclampsia. The mean platelet count was already significantly reduced and continued to fall until delivery, which was on average at 36 weeks' gestation. A comparable but smaller decrease in platelet count was seen in 55 women who had borderline but consistent increases in plasma urate concentrations. In 49 women whose plasma urate concentrations remained steady the platelet count did not change significantly before delivery. The reduced platelet count in women who develop pre-eclampsia suggests that increased platelet consumption is an early feature of the disorder.

Adult↗
PubMed1978

Longer though lighter menstrual and intermenstural bleeding with copper as compared to inert intrauterine devices.

A randomized serial study of uterine blood loss was made of 281 women fitted with one of three intrauterine contraceptive devices (IUCDs): a Lippes loop D, a Dalkon shield or a Copper 7. The increase in the amount of blood loss was greatest with Lippes loop D users and least with Copper 7 users. However, the duration of menstrual and intermenstrual bleeding and of spotting was significantly greater among Copper 7 users than with the two inert devices. Thus the mechanisms whereby IUCDs increase the duration as opposed to the volume of uterine bleeding may be different. Previous users of oral contraceptives were found to have significantly less bleeding before IUCD insertion, but showed a similar pattern of increase of uterine bleeding after IUCD insertion to those who had not used oral contraceptives. For all three IUCDs, the increment in amount and duration of uterine bleeding after insertion decreased between the first and the sixth period, on average by about 15 ml and one to two days. No subsequent improvement was found and after 12 cycles the Copper 7 users had longer but less heavy uterine blood loss than users of the Lippes loop D.

Contraceptives, Oral↗
PubMed1977

Factor VIII-related antigen and factor VIII coagulant activity in normal and pre-eclamptic pregnancy.

The changes in the ratio between factor VIII-related antigen and factor VIII activity were compared in ten patients with normal pregnancies and in ten patients with severe pre-eclampsia. In the patients with pre-eclampsia, a highly significant increase in the ratio was observed during the third trimester. No difference in the ratio between the two groups was found on day 7 of the puerperium. In the pre-eclamptic patients, the highest ratios for factor VIII-related antigen to factor VIII activity were associated with either a perinatal death or with the delivery of a severely growth retarded infant. These findings are in keeping with an increased rate of thrombin production in women with pre-eclampsia, and suggest that the ratio of factor VIII-related antigen to factor VIII activity may reflect the severity of the effect of the disease process on the fetus.

Antigens↗
PubMed1977

Treatment of hypertension in pregnancy with methyldopa: blood pressure control and side effects.

A total of 242 women with moderate hypertension in pregnancy completed a controlled trial of methyldopa (Aldomet). The hypotensive effect of methyldopa was similar to its action in non-pregnant individuals and greatly reduced the frequency of severe hypertension occurring antenatally and in labour. As pregnancy advanced, an increasing daily dose of methyldopa was needed and there was a greater use of additional hypotensive therapy. Seventeen (14-5 per cent) women assigned to methyldopa had to be transferred to another drug or had to stop treatment completely because of minor side effects, of which the commonest were lack of energy and dizziness. No serious side effects were encountered. Nine per cent of the untreated women developed severe hypertension which required treatment later in their pregnancies. Six weeks after delivery, nearly all the patients were able to stop treatment.

Blood Pressure↗
PubMed1976

Plasma-urate measurements in predicting fetal death in hypertensive pregnancy.

The relation of perinatal mortality to plasma-urate concentrations and blood-pressure was studied in 332 pregnant patients with hypertension. Perinatal mortality was markedly increased when maternal plasma-urate concentrations were raised, generally in association with severe pre-eclampsia of early onset. Plasma-urate was a better indicator than blood-pressure of prognosis for the fetus. Maternal hypertension, even severe, without hyperuricaemia, was associated with an excellent prognosis for the fetus. Conversely, when maternal hypertension was mild and hyperuricaemia was severe, the prognosis for the fetus was poor. These findings suggest that, in terms of fetal health, changes in renal handling of urate may be a more important feature of pre-eclampsia than the hypertension.

Blood Pressure↗
PubMed1976

Menstrual blood-loss with intrauterine devices.

The effect of three intrauterine contraceptive devices (I.U.D.)-Lippes D, Dalkon Shield, and Copper 7-on menstrual blood-loss has been studied serially by objective methods in 279 women. All the women had a minimum of two cycles following delivery, abortion, cessation of lactation, or previous pill or I.U.D. use. All pads and tampons used for two further menstrual cycles before and for 12 cycles after I.U.D. insertion were collected, and the blood-loss was measured by extracting the haemoglobin by conversion to alkaline haematin. Mean menstrual blood-loss increased with all three devices. The amount of loss, the percentage of women losing more than 80 ml, the decline in haemoglobin concentration, and the incidence of anaemia during the 12 cycles following insertion were all greater among users of the Lippes Loop than of the Copper 7 with generally intermediate values for Dalkon Shield users. The mean increases in blood-loss were: for parous women fitted with the Lippes Loop, 48 ml, with the Dalkon Shield, 34 ml, and with the Copper 7, 18 ml; for nulliparae fitted with the small size of Dalkon Shield, 27 ml, and, with the Copper 7, 19 ml.

Blood Specimen Collection↗
PubMed1976

Luteinizing hormone-releasing hormone for induction of follicular maturation and ovulation in women with infertility and amenorrhea.

Five patients with primary infertility and secondary amenorrhea who did not respond to clomiphene with a gonadotropin or estrogen surge were treated with 500 mug of luteinizing hormone, follicle-stimulating hormone-releasing hormone (LH-RH), self-administered subcutaneously every 8 hours for 14 days. Of four patients who responded to this treatment, three showed follicular maturation, ovulation, and menses, although the luteal phase was deficient; in the fourth patient, follicular maturation and menses occurred without evidence of ovulation. For their second course of treatment these four patients were given LH-RH with the addition of human chorionic gonadotropin when the urinary estrogen levels indicated follicular maturation. All four patients responded with ovulation, an adequate luteal phase, and menses, without clinical indication of ovarian hyperstimulation. These results suggest that LH-RH may be a better alternative to human menopausal gonadotropin in the treatment of anovulatory infertility.

Adult↗
PubMed1976

Reversed diurnal blood pressure rhythm in hypertensive pregnancies.

1. Reversal of the normal diurnal blood pressure pattern has been demonstrated in women with severe hypertension and renal impairment in pregnancy (pre-eclampsia). 2. Maximum arterial pressure occurred at night in these women. The phenomenon was not due to hypotensive drug therapy or posture. Patients with uncomplicated essential hypertension in pregnancy retained a normal diurnal blood pressure pattern. 3. Nocturnal hypertension in pre-eclampsia is of theoretical interest and practical importance.

Blood Pressure↗