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Biomedical subjects

A Klopper

Publications and source records attributed to A Klopper.

At least 55 records · Page 3Linked to original sources
PubMed1981

Concentration of pregnancy-associated plasma protein A (PAPP-A) in patients with pre-eclamptic toxaemia.

The plasma concentration of PAPP-A has been measured in 84 patients with pre-eclamptic toxaemia within 24 hours of their first admission to hospital. There were 51 patients who suffered from mild pre-eclampsia (late pregnancy hypertension without albuminuria). The PAPP-A values in these patients did not differ significantly from the normal value for the corresponding stage of gestation. On the other hand, the PAPP-A levels in albuminuric (severe) pre-eclampsia were significantly higher than normal; a finding which was more pronounced in those patients who presented with severe pre-eclampsia relatively early in pregnancy. It is unusual for a placental product to be raised in the presence of putative placental damage and it is suggested that PAPP-A might be involved with causal mechanisms in pre-eclampsia.

Female↗
PubMed1980

Relationship of obstetric parameters to the concentration of pregnancy-associated plasma protein A.

Pregnancy-associated plasma protein A (PAPP-A) was measured by rocket immunoelectrophoresis in 272 patients at 34 weeks of pregnancy and within 48 hours before delivery. The values obtained have been compared to maternal parameters (age, weight, weight gain, blood group, rhesus factor, and parity) and to fetal parameters (sex, weight, Apgar score, rhesus factor, blood group, and placental weight). Maternal age, increased parity, and increased body weight are related to decreased PAPP-A levels. On the other hand, mothers carrying male fetuses, rhesus-negative children, and babies with Apgar scores higher than 7 at 1 minute have increased PAPP-A concentrations. These findings are discussed in relation to PAPP-A's involvement in the maternal immunologic system.

Adult↗
PubMed1980

Assay of a placental protein to determine fetal risk.

Plasma concentrations and total amounts of pregnancy associated plasma protein A were determined in 272 patients at 34 weeks' gestation by immunoelectrophoretic assay. The mean plasma concentration and mean total amount of this protein were closely related (r = 0.9643) and were significantly raised in patients who subsequently developed pre-eclampsia (28 patients), went into premature labour (12), or suffered from antepartum haemorrhage (10). Mean values in all patients delivering growth-retarded babies were also raised, but when the results for such patients who also had other complications were excluded there were no differences between the sets of means. The assays were easily performed, and they may be a useful technique for screening pregnant women to detect those at risk of developing pre-eclamptic toxaemia, although the full potential of these assays cannot be realised until the protein's function is known.

Female↗
PubMed1980

Separation of two pregnancy-associated proteins with SP1 determinants and the conversion of SP1 beta to SP1 alpha.

The alpha and beta forms of the pregnancy-associated protein, SP1 which have been previously identified in late pregnancy serum were found to be also present in the placenta. The alpha form was somewhat more difficult to extract, requiring the use of detergents in the extracting buffer. The two variants can be separated by ion exchange chromatography or by gel filtration and distinguished by the different shapes of the precipitation rockets on immunoelectrophoresis. The alpha variant appears to be the larger molecule on gel filtration. When solutions of SP1 are acidified to pH 2.5 the beta form is rapidly converted to the alpha form and the latter is slowly destroyed. It is suggested that SP1 alpha represents the combination of SP1 beta with some other protein present in the placenta and in the serum.

Chromatography, Gel↗
PubMed1980

Tests of fetal wellbeing in the third trimester of pregnancy.

Five different products secreted by the fetoplacental unit into the maternal circulation were measured in 272 patients when they were 34 weeks pregnant. The most useful indicator of present pathology or future complications of pregnancy was a placental protein, pregnancy associated plasma protein. A which was raised in pre-eclamptic toxaemia, antepartum haemorrhage and premature labour. The highest values were recorded in pre-eclampsia before any signs of the disease were evident. Schwangerschafts protein 1 was also raised in pre-eclampsia and antepartum haemorrhage but only after the disease had presented. Placental lactogen was also raised in pre-eclampsia and its measurement may have some predictive value. Total oestriol was lowered in fetal growth retardation and the unconjugated steroid raised in pre-eclampsia and lowered in retarded fetal growth.

Estriol↗
PubMed1980

The risk of endometrial carcinoma from oestrogen therapy of the menopause.

Although there is no doubt that increasing numbers of women are presenting with carcinoma of the endometrium, this could be due only to the fact that many more women live to an age when they are liable to get this cancer. Even when age specific incidence rates are considered, the apparent increase could be due to risk factors other than oestrogens. Recent developments in hormone replacement therapy have placed increasing emphasis on the natural oestrogens, oestradiol and oestrone, but they present problems of their own. Nor has the induction of periodic bleeding by cyclical administration of oestrogens, with or without a progestogen, proved an unqualified success. A special case might yet be made for the weaker physiological oestrogen, oestriol.

Adolescent↗
PubMed1979

Measurement of pregnancy associated plasma protein A (PAPP-A).

A method is described for measuring pregnancy associated plasma protein A (PAPP-A) in the maternal circulation during the 3rd trimester of pregnancy. The method used is a modification of Laurell's electroimmunodiffusion technique.

Antibody Specificity↗
PubMed1979

Studies on pregnancy-associated plasma protein A in the third trimester of pregnancy.

The plasma concentration of pregnancy-associated plasma protein A (PAPP-A) was measured in 34 women during the last 10 weeks of pregnancy. From 30 to 36 weeks the concentration of this protein increased steadily. Thereafter the concentration of PAPP-A rose more steeply, the highest amounts being found in early labour. The concentration of PAPP-A in peripheral venous blood and in the uterine vein was much the same. It was less in the retroplacental blood and a great deal less in the peritoneal fluid. The day-to-day variation was small; the coefficient of variation at 38 weeks was only 7.3 per cent. After delivery, the concentration of PAPP-A fell more slowly than other placental proteins and steroids, the average half-life being 51 hours. Although there is no doubt that PAPP-A is a product of the syncytiotrophoblast, our findings suggest that it is not simply secreted by the chorionic villi directly into the intervillous space but makes its way into the maternal circulation by a more circuitous route.

Ascitic Fluid↗
PubMed1979

Enterohepatic circulation of oestriol: a study of the effects of ampicillin on plasma oestriol levels.

Plasma total oestriol was measured daily before and during ampicillin therapy in five pregnancy patients and in eight patients, four of whom were receiving ampicillin, for four days following delivery. Ampicillin caused a fall in plasma oestriol of 25 per cent during the first three days of treatment, thereafter the level remained stable with a lower day-to-day variability than in untreated patients. Ampicillin reduced the plasma half life of total oestriol by 60 per cent. This study illustrates how the re-entry of oestriol from the gut leads to irregular fluctuations in plasma oestriol levels and helps to keep up the plasma concentration of the steroid when inflow from the fetoplacental unit is cut off.

Ampicillin↗
PubMed1978

Placental secretion of oestrogens and protein hormones.

In order to trace the passage of steroids and proteins from the placenta to the maternal peripheral blood, samples of retroplacental blood, uterine vein blood and peripheral blood were taken from women undergoing Caesarean section at term. The concentration of unconjugated oestriol, total oestriol, human placental lactogen and pregnancy specific beta1 glycoprotein was measured. The oestrogen concentration in the uterine vein was higher than the peripheral blood, the placental lactogen was slightly higher and the pregnancy specific beta1 glycoprotein was the same in the uterine vein and the peripheral veins. In keeping with this, the retroplacental blood had a high concentration of oestrogen, moderately raised placental lactogen and a low pregnancy specific glycoprotein concentration. It is concluded that there is a rapid secretion of oestriol from placenta to the mother; a slower secretion of placental lactogen and no clear evidence of a flow of pregnancy specific glycoprotein from the placenta.

Cesarean Section↗
PubMed1978

The plasma half-life of placental hormones.

Blood was collected from 12 women following Caesarean section or normal delivery at term. The decline in plasma concentration of total oestriol, oestriol sulphate, oestriol glucosiduronate, unconjugated oestriol, human placental lactogen and pregnancy specific beta1 glycoprotein following delivery of the placenta was studied for 120 hours. The steroids and human placental lactogen fell very rapidly but pregnancy specific beta1 glycoprotein declined much more slowly. Analysis of the curves of puerperal decline suggests that the oestriol moieties are distributed in many compartments of the mother but that the proteins penetrate only to the plasma and the interstitial fluid.

Estriol↗
PubMed1977

Plasma oestriol and placental proteins: a cross-sectional study at 38 weeks gestation.

Blood was collected from 53 normal women in the 38th week of pregnancy. The plasma concentration of unconjugated oestriol, total oestriol and oestriol sulphate was measured and also human placental lactogen and pregnancy specific beta1 glycoprotein. The normal spread of the two proteins was found to be slightly smaller than that of the oestrogens. The concentrations of unconjugated and of total oestriol were related; otherwise these substances varied independently of one another. The concentration of these substances was not related to other obstetric parameters.

Estriol↗