Endothelin stimulates ACTH secretion in the ovine fetus.

The endothelins are a series of peptides with potent vasoconstrictor effects in vascular tissue; however, they may also have a role as neuroendocrine secretagogues because endothelin and endothelin receptors have been found in hypothalamic and pituitary tissues. Since activation of the fetal hypothalamo-pituitary-adrenal axis is crucial to the process of parturition, the aim of this study was to determine whether endothelin could activate the hypothalamo-pituitary-adrenal axis in the ovine fetus. Catheters were inserted into the carotid artery, jugular vein and lateral cerebral ventricle of six fetal lambs at 118-122 days' gestation.

Increased concentrations of cytokines interleukin-6 and interleukin-1 receptor antagonist in plasma of women with preeclampsia: a mechanism for endothelial dysfunction?

Objective: To determine if plasma concentrations of defined cytokines are increased in women with preeclampsia, and to correlate any increases with the elevated concentrations of the vascular cell adhesion molecule (VCAM)-1.

Methods: Twenty primigravidas with preeclampsia were compared to 20 healthy primigravidas. Plasma levels of cytokines, tumor necrosis factor-alpha (TNF alpha), interleukin (IL)-6, IL-8, IL-1 beta, IL-1 receptor antagonist (IL-1ra), granulocyte macrophage-colony-stimulating factor (GM-CSF), and VCAM-1, were measured by enzyme-linked immunosorbent assay.

Corticotrophin-releasing factor immunostaining is present in placenta and fetal membranes from the first trimester onwards and is not affected by labour or administration of mifepristone.

Background And Objectives: Corticotrophin releasing factor (CRF) is present in the human placenta and fetal membranes. Placental CRF content and plasma CRF concentrations rise throughout gestation and fall rapidly after delivery. The regulation of CRF production from the placenta is poorly understood.

Mechanical stretch increases proto-oncogene expression and phosphoinositide turnover in vascular smooth muscle cells.

Objective: To determine whether changes in haemodynamic load, simulated in vitro by mechanically stretching cultured vascular smooth muscle cells, could be transduced into biochemical signals similar to those produced by growth factors.

Design: A system was developed which was capable of stretching cultured vascular smooth muscle cells from 0 to 20%. The effect of stretching quiescent vascular smooth muscle cells on both c-fos messenger RNA (mRNA) expression and release of total inositol phosphates was determined over a time interval of 0-360 min.

Familial thrombophilia and activated protein C resistance: thrombotic risk in pregnancy?

An abnormal anticoagulant response in vitro to activated protein C (aPC) has been proposed as an aetiological factor in familial thrombophilia. It is postulated that this phenomenon is due to an inherited molecular defect of factor V resulting in poor inactivation by aPC. We conducted a family study when the proband presented in her second pregnancy with superficial phlebitis, a history of deep venous thrombosis and a family history of venous thromboembolic disease.

The cell adhesion molecule, VCAM-1, is selectively elevated in serum in pre-eclampsia: does this indicate the mechanism of leucocyte activation?

Objective: To determine whether circulating levels of cell adhesion molecules, markers of endothelial damage and leucocyte activation, were increased in pre-eclampsia.

Design: Serum was prepared from peripheral venous blood and stored at -70 degrees C. The cell adhesion molecules, VCAM-1, E-Selectin and ICAM-1, were measured by ELISA.

Causes and clinical consequences of Rhesus (D) haemolytic disease of the newborn: a study of a Scottish population, 1985-1990.

Objective: To identify the reasons behind failures to prevent the development of Rhesus (D) haemolytic disease of the newborn.

Design: Retrospective analysis of the case records of all pregnancies that resulted in the birth of an infant with a positive direct antiglobulin test on the cord red cells born to Rh(D) negative women between 1 April 1985 and 31 March 1990.

Setting: Obstetric units in the South East Scotland region and the South East Scotland Regional Blood Transfusion Service Antenatal Laboratory.

Lack of association between maternal phosphoglucomutase-1 phenotype and fetal macrosomia in diabetic pregnancy.

Objective: To assess the reports that maternal phosphoglucomutase-1 (PGM1) phenotype is highly related to macrosomia in diabetic pregnancy. This could be either a direct metabolic phenomenon, or the PGM1 locus could be a marker for a tightly linked gene involved in the maternal control of fetal growth.

Design: A comparative biochemical genetic study.

Fetal growth, gestation length and phosphoglucomutase-1 phenotype.

This study investigates reports that phosphoglucomutase-1 (PGM1) phenotype is associated with fetal growth and gestation length. A total of 350 women were studied, 234 having uncomplicated pregnancies and 114 with a baby weighing greater than 90th centile, corrected for parity, gestation and fetal sex. All women had gestation confirmed by early ultrasound.

The effect of introduction of umbilical Doppler recordings to obstetric practice.

Objective: To assess the effect on obstetric practice of clinician access to umbilical artery Doppler ultrasound results.

Design: Randomised controlled trial.

Setting: A large teaching hospital.

Plasma prostaglandin metabolite concentrations in normal and dysfunctional labour.

Objective: To determine the concentrations of the metabolites of prostaglandin E2 (PGEM) and of prostaglandin F2 alpha (PGFM) prior to the onset of labour and during spontaneous labour, and to correlate the changes in concentrations of these metabolites with labour outcome.

Design: Longitudinal study throughout labour.

Setting: Labour ward of a large maternity unit.

Prostaglandins and the cervix.

The dramatic capabilities of prostaglandins to modify the condition of the uterine cervix have been exploited to the considerable benefit of patients who require therapeutic interventions for labour induction and termination of pregnancy. This will continue to be an important facet of clinical obstetric and gynaecologic practice, although further refinements and improvements in techniques seem certain to continue.

The effect of pH on release of PGE2 from vaginal and endocervical preparations for induction of labour: an in-vitro study.

Objective: To study the effect of pH and precoating with obstetric cream on the release of prostaglandin E2 (PGE2) from commercially available triacetin and starch based gels, lactose based vaginal tablets and sustained release hydrogel polymer pessaries in-vitro.

Design: A prospective observational study.

Methods: PGE2 preparations held in dialysis bags were placed in Ringers lactate buffer and release of PGE2 into the buffer was measured over 8-12 h by radioimmunoassay.

Gemeprost-induced cervical ripening: histological and biophysical effects.

The mechanism of prostaglandin-induced cervical ripening is not clear. The aim of this study was to measure the biophysical and histological effects of gemeprost on the cervix. Thirty-four women admitted for surgical termination of pregnancy in the first trimester were randomised in a double-blind manner to receive either gemeprost or placebo prior to surgery.

Doppler umbilical artery flow velocity waveforms in diabetic pregnancy.

Objective: To assess the effect of uncomplicated diabetes on umbilical artery flow velocity waveforms (FVWs); to investigate the relation between glycaemic control and FVWs and the predictive value of umbilical artery FVWs for antenatal fetal compromise.

Design: Prospective descriptive study.

Setting: A large diabetic pregnancy clinic in a teaching hospital.

Dexamethasone inhibits basal and stimulated prostaglandin E2 output from human placental cells by inhibition of prostaglandin H synthase.

In view of the temporal relation between elevated concentrations of glucocorticoids and prostaglandins (PG) at the time of parturition, we have examined the effects of dexamethasone on PGE2 output by mixed cell preparations from human placentae at term maintained in short-term (48 or 96 h) culture. Dexamethasone inhibited placental PGE2 output in a dose-dependent fashion. The effect on placental cells was more marked than on short-term cultures of amnion cells and was not influenced by the presence of progesterone.