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Biomedical subjects

A B Anderson

Publications and source records attributed to A B Anderson.

At least 55 records · Page 3Linked to original sources

Reduction by naproxen of excessive menstrual bleeding in women using intrauterine devices.

Thirty-four patients using intrauterine contraceptive devices and experiencing excessive menstrual bleeding (more than 80 ml average loss for 2 cycles) were treated with the prostaglandin synthetase inhibitor naproxen. The trial was conducted according to a double-blind placebo-controlled crossover design. Each patient received 2 of 3 treatments: naproxen in high dose (1250 mg/day for 5 days), naproxen in low dose (500-mg loading dose, than 750 mg/day for 5 days), or placebo. Each treatment was taken during 2 consecutive menstruations. When all data were pooled, statistically significant reduction in menstrual bleeding was found with both high- and low-dose naproxen treatment compared with placebo therapy (P < .002). Low- and high-dose naproxen reduced menstrual blood loss by 22% and 32%, respectively, whereas the change with placebo was minimal. Although the dose had no significant effect on mean menstrual loss, the number of treatment cycles in which menstrual blood loss was reduced by 50% as compared with pretreatment cycles strongly suggested a dose response. In almost 60% of naproxen-treated cycles, mean menstrual blood loss was less than 80 ml, whereas during placebo-treated cycles the distribution of menstrual loss was similar to that of control cycles.

Clinical Trials as Topic↗

Evidence that fetal membranes are not involved in cortisol metabolism: study of dichorionic twin pregnancies.

11 beta-Hydroxysteroid dehydrogenase (11 beta-HSD, E.C.1.1.1.146) activity has been measured in samples of decidua, choriodecidua, and chorion obtained from five sets of dichorionic twins, with radiolabeled cortisol and cortisone used as substrates. 11 beta-HSD activity was significantly higher in the decidua than in the choriodecidua, in both the oxidative (cortisol to cortisone) are reductive (cortisone to cortisol) directions (activity expressed as percentage conversion): 53.4% +/- 6.7% versus 38.5% +/- 7.4% (p < 0.05) and 21.3% +/- 2.2% versus 15.3% +/- 3.2% (p < 0.025) (mean +/- SEM, n = 10). No measurable activity in either direction was found in the chorion obtained from the wall separating the two amniotic sacs (decidua-free chorion). In both decidua and choriodecidua oxidative activity was higher than reductive activity (p < 0.005 for both). These results demonstrate that 11 beta-HSD activity attributed to the chorion is due to decidual contamination.

11-beta-Hydroxysteroid Dehydrogenases↗

Specific changes in the in vitro production of prostanoids by the ovine cervix at parturition.

A method of tissue superfusion has been used to measure in vitro prostanoid production by the ovine cervix during late pregnancy and at parturition. In late pregnancy (105-135 days of gestation) cervical tissue produced relatively large amounts of prostaglandin E (PGE); in comparison, the production rates of prostaglandin F (PGF), 13, 14-dihydro-15-oxo-prostaglandin F (PGFM) and 6-oxo-prostaglandin F1 alpha were generally low. Thromboxane B2 (TXB2) production was minimal and often unmeasurable. There were significant increases in the production rates of PGE and 6-oxo-PGF1 alpha by cervical tissue taken immediately after delivery, when compared to late pregnancy. Mean production rates of PGE increased from 19.8 +/- 4.1 to 43.8 +/- 7.4 ng/g. dry wt./min; 6-oxo-PGF1 alpha production rates increased more than three-fold from 10.0 +/- 2.7 to 34.6 +/- 9.8 ng/g. dry wt./min (means +/- S.E.M.). There were no significant differences in the rates of production of PGF, PGFM and TXB2 by the two groups.

Animals↗

Release of prostaglandins after amniotomy is not mediated by oxytocin.

The rise in peripheral plasma levels of 13,14-dihydro-15-keto-prostaglandin F (PGFM) following amniotomy has now been shown to be maximal within five minutes of the procedure, and levels remain elevated for at least 30 minutes. There was no change in plasma oxytocin levels with amniotomy and therefore a local mechanism for prostaglandin release has been postulated.

Female↗

Reduction of menstrual blood loss by danazol in unexplained menorrhagia: lack of effect of placebo.

In women with menorrhagia of unknown cause, the efficacy of the drug danazol in reducing heavy menstrual blood loss was investigated making objective measurements of menstrual blood loss. Drug regimens tested were daily administration of 200 or 100 mg danazol for 12 weeks and daily danazol given in the luteal phase or during menstruation. The results suggest that 200 mg danazol daily is the most acceptable regimen clinically since it significantly reduced menstrual blood loss and was associated with a relatively low incidence of side effects. In 16 women on this dose menstrual blood loss was suppressed from a mean pre-treatment loss of 183 +/- 25 ml to 38 +/- 11 ml (p < 0.01) in the second, and 26 +/- 9 ml (p < 0.01) in the third treatment months. The majority of women had regular episodes of bleeding with no alteration in cycle length and a reduction in the number of days of bleeding. Although 100 mg daily suppressed menstrual blood loss, particularly by the third month of treatment, it increased the number of episodes of bleeding in some women which they found unacceptable. Both 200 mg and 100 mg relieved dysmenorrhoea in the majority of women presenting with the symptoms. Danazol taken daily in the early follicular or luteal phase of the menstrual cycle did not significantly alter menstrual blood loss. There was no effect of placebo therapy on measured menstrual blood loss in a single blind trial in eight women with menorrhagia.

Adult↗

The in vitro production of prostanoids by the human cervix during pregnancy: preliminary observations.

The ability of the pregnant human cervix to produce prostanoids has been studied using an in vitro superfusion technique. Tissues obtained from four patients during the first trimester of pregnancy produced prostaglandin E (PGE), prostaglandin F (PGF), 13,14-dihydro-15-oxo-prostaglandin F (PGFM) and 6-oxo-prostaglandin F1 alpha (6-oxo-PGF1 alpha). Production of thromboxane B2 (TXB2) was minimal. Preliminary studies using tissue taken at Caesarean hysterectomy during the last trimester of pregnancy indicate that the cervix may show increased prostanoid production during active dilatation. The implications of these observations for an involvement of prostanoids in cervical softening during human parturition are discussed.

Cervix Uteri↗

Effect of danazol on serum gonadotrophins and steroid hormone concentrations in women with menorrhagia.

In 13 ovulatory women with objective evidence of menorrhagia (menstrual blood loss greater than 80 ml), danazol 400 mg given daily for 12 weeks suppressed ovulation as shown by absence of gonadotrophin peaks, low serum progesterone levels and flat basal body temperature recordings. Serum concentrations of luteinising hormone and follicle stimulating hormone were within the range found during the normal menstrual cycle but oestradiol concentrations tended to fall, reaching levels less than 100 pmol/l in some patients. Danazol treatment had no effect on levels of androstenedione or dehydroepiandrosterone and its sulphate. The presence or absence of cyclical bleeding on treatment, and the measured blood loss was unrelated to circulating oestradiol levels.

Adult↗

Relation between measured menstrual blood loss and patient's subjective assessment of loss, duration of bleeding, number of sanitary towels used, uterine weight and endometrial surface area.

In 92 women complaining of heavy but regular periods for which no cause was found, the relation was studied between measured menstrual blood loss during two consecutive periods and the patient's subjective assessment of blood loss, the number of days of bleeding, and the number of sanitary pads and tampons used. There was no correlation between menstrual blood loss and these parameters. In many women these parameters are not a reliable indicator of the volume of menstrual blood loss. In 40 of the 92 women, who subsequently had a hysterectomy because of their complaint of menorrhagia, the uterus was weighed and the endometrial surface area measured. The view that menorrhagia is associated with a large uterus or a large endometrial surface area could not be confirmed.

Blood Volume↗

Concentrations of the prostacyclin metabolite, 6-keto-prostaglandin F1 alpha, in amniotic fluid during late pregnancy and labour.

Concentrations of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha, the stable metabolite of prostacyclin, PGI2) have been measured in amniotic fluid obtained during late pregnancy and labour. Samples taken at amniotomy during spontaneous labour contained a significantly greater concentration of 6-keto-PGF1 alpha than samples taken at amniotomy before the onset of labour (p less than 0.01). There was no correlation between the level of 6 keto-PGF1 alpha in amniotic fluid before labour and gestational age (p greater than 0.1). It is suggested that prostacyclin may have a functional role in the mechanism of parturition in man.

Amniotic Fluid↗

The effect of cervical encerclage on plasma prostaglandin concentrations during early human pregnancy.

In women having either cervical encerclage under general anaesthesia or a vaginal examination in the early second trimester of pregnancy, peripheral plasma levels of 13,14-dihydro-15-keto prostaglandin F (PGFM) were measured before and after each procedure. A significant rise in circulating levels of PGFM was found within minutes of completing cervical encerclage but not after vaginal examination or induction of general anaesthesia.

Anesthesia, General↗

Melatonin in the maternal and umbilical circulations during human parturition.

The concentration of melatonin in maternal peripheral plasma was measured during late pregnancy, term and pre-term labour. There was a small increase in the mean concentration of melatonin during labour which was significant in term labour. Umbilical arterial and venous plasma, whether obtained at term, after spontaneous vaginal delivery or at Caesarean section, contained significantly greater concentrations of melatonin than maternal plasma. A significant arterio-venous difference was demonstrated for both groups of umbilical samples with raised venous levels after spontaneous vaginal delivery but higher arterial levels at Caesarean section.

Cesarean Section↗

The effect of danazol on menorrhagia, coagulation mechanisms, haematological indices and body weight.

Eighteen patients with objective evidence of menorrhagia (more than 80 ml menstrual blood loss) were treated with danazol for twelve weeks. Danazol significantly reduced the menstrual blood loss from 231 +/- 39 ml (mean +/- SEM) to 135 +/- 33 ml in the first treatment month and the mean loss thereafter was only 21 ml and 3 ml for the second and third months respectively. A rapid increase in haemoglobin level and a reduction in the number of days of bleeding were also observed on danazol treatment. No important effect on the coagulation profile was observed during the period of study. Three months after stopping danazol, menstrual blood loss (103 +/- 27 ml) was still significantly less than the pre-treatment loss.

Adult↗

Changes in coagulation factors in postmenopausal women on ethinyl oestradiol.

Coagulation factors II, VII, X, VII + X complex and anti-thrombin III were measured in 10 postmenopausal women before, during and after a four-month course of 20 microgram daily of ethinyl oestradiol, taken three weeks in four. Factors VII, X and VII + X complex rose significantly during treatment but only factor X levels were significantly elevated at the end of the four-month treatment period. There was no change in factor II or anti-thrombin III levels. These effects on coagulation factors during ethinyl oestradiol therapy are, in general, similar to those found during treatment with conjugated equine oestrogens and oestradiol valerate in a previous study from the same laboratory. It seems likely that equipotent doses of ethinyl oestradiol and 'natural' oestrogens have similar effects on these coagulation factors.

Antithrombin III↗

A retrospective study of induction of labour.

The labour, delivery and state of the newborn were compared retrospectively in a group of women who had labour induced and a group who started labour spontaneously. There were 200 women at term in each group, individually matched for age, parity and social class and with no medical or obstetric complications prior to labour. The induced group showed a higher incidence of epidural anaesthesia, fetal monitoring and operative delivery. Sixty had forceps deliveries and five had Caesarean sections compared with two forceps deliveries and no Caesarean sections in the 'spontaneous onset' group. The higher incidence of operative deliveries in the induced group was not fully explained by the excess of epidurals and fetal monitoring received. More of the babies born after an induced labour had endotracheal intubation during resuscitation.

Adult↗