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Biomedical subjects

J Bonnar

Publications and source records attributed to J Bonnar.

At least 109 records · Page 6Linked to original sources
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↗
PubMed1976

The ultrastructure of the arterial supply of the human placenta in pregnancy complicated by fetal growth retardation.

The ultrastructure of the arterial supply of the human placenta was studied in 15 pregnancies with severe fetal growth retardation. There were five patients with essential hypertension and superimposed pre-eclampsia, five patients with pre-eclampsia, and five patients with no hypertension. The patients were delivered by elective Caesarean section and biopsies of the placental bed were taken under direct vision. Extensive placental infarction was invariably present and the degree of infarction reflected the extent of pathological changes in the spiral arteries. In both hypertensive and normotensive patients the spiral arteries and basal arteries of the decidua showed occlusive atheromatous lesions with considerable fibrin deposition and accumulation of lipid-laden cells in both the intima and media of the vessel walls.

Adult↗
PubMed1976

Fibrinolytic activity in utero and bleeding complications with intrauterine contraceptive devices.

Increased menstrual loss and irregular uterine bleeding are major drawbacks to acceptibility of intrauterine contraceptive devices (IUCDs). Fibrinolytic activity around IUCDs removed from 80 women was measured by embedding the device immediately after removal in a plasminogen-rich fibrin plate. In fifteen of the women an endometrial biopsy was also taken at the time of removal of the IUCD. In women who had the IUCDs removed because of bleeding a much higher fibrinolytic activity was found than in women not complaining of excessive bleeding. The fibrinolytic activity was shown to be due to plasminogen activator and not plasmin. The findings suggest that the excessive menstrual bleeding which occurs with the IUCD may be due to enhancement of fibrinolytic activity in the endometrium which can be modified by fibrinolytic inhibitors such as epsilon aminocaproic acid.

Aminocaproic Acid↗
PubMed1976

Maternal serum alpha-fetoprotein and previous neural tube defects.

A case-control study involving 63 pregnancies showed that women who had previously had an infant with anencephaly or spina bifida did not have raised serum alpha-fetroprotein (AFP) levels in subsequent unaffected pregnancies. The value of a serum AFP determination in such women is discussed. If the serum AFP level is normal and if ultrasonography excludes anencephaly the risk of spina bifida might be low enough (about 1 per cent) to make diagnostic amniocentesis difficult to justify. Conversely, a high serum AFP value in such women should not be acted on without confirmation of an abnormality by ultrasonography and, if that is negative, by diagnostic amniocentesis.

Amniocentesis↗
PubMed1976

An evaluation of the luteinizing hormone releasing hormone (LH-RH) test in patients with secondary amenorrhoea.

An analysis of the gonadotrophin response to an intravenous injection of LH-RH (50 mug) has been undertaken in 41 patients with secondary amenorrhoea. Thirty-five of the patients were free of any recognizable pathology to account for their amenorrhoea and apparently had a dysfunction of the hypothalamic-pituitary axis. In these patients, the gonadotrophin response to LH-RH was highly variable. There was in general a correlation between baseline plasma LH or FSH levels and their respective increments. There was no correlation, however, between basal oestrogen levels and gonadotrophin increments except in the case of those patients whose basal levels of plasma FSH were higher than those of LH and in those patients whose body weight was less than the ideal for the population. It appears that the gonadotrophin response to a single injection of LH-RH in the majority of patients with secondary amenorrhoea of unknown origin is too variable to be of use either as a diagnostic or prognostic tool.

Adult↗
PubMed1976

Plasminogen activators in the endometrium of women using intrauterine contraceptive devices.

Plasminogen activators in the endometrium before and after the insertion of an intrauterine contraceptive device (IUCD) were studied; an increase in the concentration was found following IUCD insertion in 16 of the 20 women. This change will enhance endometrial fibrinolysis and may explain the increased menstrual bleeding which usually follows insertion of an IUCD.

Adult↗
PubMed1976

Effect of sterilization on menstrual blood loss.

Menstrual blood loss was measured objectively in 25 women for up to three months before and for six to twelve months after tubal ligation. The operation made no significant difference to menstrual blood loss.

Adult↗
PubMed1976

The persistence of dextran 70 in blood plasma following its infusion, during surgery, for prophylaxis against thromboembolism.

An infusion of dextran (mean molecular weight 70000) in normal saline (either 1 litre or 500 ml) was given to patients undergoing hysterectomy. The infusion was started at induction of anaesthesia and continued throughout the operation and for up to 5 h thereafter. The rate of elimination of dextran was independent of the dose given. The time to eliminate half the dose was nearly two days and up to 10% was still present in the circulation after one week. The persistence of dextran in the plasma in these amounts and for this length of time may have considerable implications in the prophylaxis of postoperative deep venous thrombosis.

Blood Glucose↗
PubMed1976

The role of coagulation and fibrinolysis in preeclampsia.

The coagulation and fibrinolytic systems play a key role in maintaining the integrity and patency of the vascular compartment. Pregnancy induces extensive physiological changes in these systems, thus creating an enhanced capacity to produce fibrin and a diminished ability to remove it. Fibrin deposition localized to the uteroplacental circulation is a feature of normal pregnancy. In women with fatal eclampsia, disseminated intravascular coagulation with fibrin deposition in the renal glomeruli is well documented. The condition of preeclampsia is not well defined. Nonetheless, evidence of intravascular coagulation, as shown by elevated levels of fibrin degradation products and reduced platelet counts, has been found in many women with preeclampsia. Serial studies showed that thrombin generation, as indicated by the ratio of factor VIII-related antigen to factor VIII coagulant activity, is considerably in excess of that which occurs in normal pregnancy, and its appearance coincides with the development of the clinical features of preeclampsia. Heparin therapy has bot been proven of value in established preeclampsia, but this fact does not disprove that role that intravascular coagulation may play in the pathogenesis of the disease. A controlled trial ina high-risk group of low-dose he;arin and an antiplatelet agent from the 16th to the 18th weeks of pregnancy onwards is required to elucidate the role of intravascular coagulation in preeclapmsia and its effect on the fetus.

Blood Cell Count↗
PubMed1976

Variability of blood pressure in normal and abnormal pregnancy.

Using an automatic indirect method of measurement, diurnal blood pressure patterns have been studied in normal and hypertensive pregnancies. In the last trimester, normotensive and hypertensive pregnant subjects show small but significant increases of blood pressure that develop especially during the evening and night. This change is more clear-cut for the systolic than the diastolic pressure. The tendency to a relatively greater increased pressure at night is exaggerated in preeclampsia. This fact explains earlier observations of a dimunution of the nocturnal fall of blood pressure in preeclampsia. In very severe preeclampsia, the nocturnal increase of blood pressure may be so exaggerated as to reverse the normal diurnal blood pressure pattern. These changes have been documented sequentially, and their implications are discussed briefly.

Blood Pressure↗
PubMed1975

Coagulation changes during second-trimester abortion induced by intra-amniotic prostaglandin E2 and hypertonic solutions.

The coagulation system was studied in twenty-seven patients undergoing second-trimester abortion induced by intra-amniotic prostaglandin (P.G.) E2 alone and in combination with a hypertonic solution of urea or glucose. Changes consistent with intravascular coagulation, namely a rise in fibrin degradation products and a fall in plasma-fibrinogen and platelet-count, were observed in those patients treated using P.G.E2 with hypertonic urea. Similar but less pronounced changes were found in the group treated using P.G.E2 with hypertonic glucose. In patients treated with P.G.E2 alone no changes suggestive of intravascular coagulation were detected. One patient treated using P.G.E2 with hypertonic urea who did not abort for 26 hours demonstrated changes indicative of a pronounced degree of disseminated intravascular coagulation. These findings show that when abortion is induced using P.G.E2 and a hypertonic solution, particularly hypertonic urea, disseminated intravascular coagulation can occur as a result of a hypertonic agent being used.

Abortion, Induced↗
PubMed1975

Effect of breast-feeding on pituitary-ovarian function after childbirth.

Pituitary and ovarian function at the end of pregnancy and during the first six weeks after delivery was investigated serially in women who fully breast-fed their infants and in women who did not. In the women who did not breast-feed the plasma prolactin level decreased rapidly and from the third day after delivery was significantly lower than in the breast-feeding mothers, reaching the normal range of the menstrual cycle by the third week of the puerperium. In the breast-feeding mothers the plasma prolactin was still raised six weeks after delivery. The levels of FSH in both groups were identical and increased over the third week of the puerperium. Plasma oestrogen fell steeply in both groups during the first two weeks after delivery. In the breast-feeding mothers plasma oestrogen remained depressed but increased in the non-lactating women, reflecting follicular development in the ovary in response to FSH; the plasma oestrogen levels were significantly higher in the non-lactating women from the 17th day of the puerperium onwards. These findings support the concept that in breast-feeding women prolactin delays the return of ovulation by inhibiting the ovarian response to FSH stimulation.

Breast Feeding↗