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Biomedical subjects

C W Redman

Publications and source records attributed to C W Redman.

At least 235 records · Page 13Linked to original sources

HLA-DR positive cells in the human placenta.

A population of heterogeneous HLA-DR positive cells has been identified in the human placenta and decidua using immunochemical and histochemical methods. These cells are found in three areas: the subepithelial layer of the amnion, the decidua, and more sparsely within the chorionic villous stroma. In addition to HLA-A, -B and -C antigens, they also express the leucocyte-common antigen, indicating their origin from bone marrow precursors. The majority have a characteristic stellate shape with many cytoplasmic processes. In the villous stroma these stellate cells can be distinguished from the Hofbauer cells (placental macrophages) by their morphology, stronger expression of HLA-DR and lack of lysosomal enzyme activity. In the amnion and decidua they cannot be clearly distinguished from tissue macrophages. By using monoclonal antibodies specific for foetal or maternal HLA-A or -B allotypes, the HLA-DR positive cells in the chorionic villi and the amnion have been shown to be foetal in origin. In contrast, most of the HLA-DR positive cells in the decidua are maternal; a few adjacent to the basal plate are foetal. The preponderance of these cells in those areas of the placenta where foetal and maternal tissues are in close proximity is striking. The possibility that some of the cells are equivalent to the dendritic cells that have been described in other tissues is discussed.

Acid Phosphatase↗

Maternal cell-mediated immunity in pregnancy--lymphocyte responses of mothers and their non-pregnant HLA identical sisters to paternal HLA.

The mixed lymphocyte reactions (MLR) of normal pregnant women and their non-pregnant HLA identical sisters have been compared, using paternal and unrelated lymphocytes as stimulator cells. Primary and secondary responses were differentiated by studying 7 day MLR time courses. All responses were of a primary nature, with neither stimulation nor suppression of the maternal MLR. These data clearly demonstrate the absence of maternal cellular sensitization to fetal (paternal) HLA.

Fathers↗

Final report of study on hypertension during pregnancy: the effects of specific treatment on the growth and development of the children.

195 (97.5%) children born to hypertensive women participating in a trial of methyldopa treatment during pregnancy were followed from birth and were extensively examined at the age of 7 1/2 years. The frequency of problems with health, physical or mental handicap, sight, hearing, and behaviour was the same in children of treated and untreated women. Sons of the untreated women were heavier and taller than those of treated women, as were their mothers. Among children of women who entered the trial between 16 and 20 weeks' gestation, sons of untreated women had larger heads than sons of treated women, but there was no difference in mean intelligence quotients. There were no significant differences between the children in the treated and untreated groups in standing and supine blood pressures, or fourteen tests of ability. Methyldopa therefore seems safe to use in pregnancy and is probably preferable to other drugs from the point of view of the neonate and child.

Antihypertensive Agents↗

Baseline in human fetal heart-rate records.

Large variations in the pattern of normal fetal heart-rate traces near term are described. The presence of flat or bimodal frequency distributions of pulse intervals in these traces complicates the derivation of a baseline by statistical methods. A system is described for deriving an appropriate baseline from which accelerations or decelerations may be measured.

Electrocardiography↗

Pattern of the normal human fetal heart rate.

With an improved method for fitting baselines to human fetal heart-rate traces, the patterns of episodic variations, accelerations and decelerations were similar in 215 64-min records from normal pregnancies and in 95 with mild hypertension and normal outcome. The change in signal loss with gestational age, by Doppler ultrasound for recording heart rate, was entirely due to the greater loss in episodes of high heart-rate variation. The changes in the numbers and sizes of accelerations and decelerations with gestational age were described. There were many records which had only one or no acceleration at 28-33 weeks gestation (16.2%) or 34-41 weeks (7.3%). However, only two (0.7%) had episodes of high heart-rate variation lasting less than 10 min from 28 weeks onwards. The presence of these episodes, with clusters of fetal movements, is therefore likely to be a better numerical index of normality.

Female↗

Maternal cell-mediated immunity in normal and pre-eclamptic pregnancy.

Maternal cell-mediated immunity (CMI) to fetal (paternal) HLA was studied in both normal and pre-eclamptic pregnancies. Maternal-paternal mixed lymphocyte reactivity (MLR) was assessed using macrophage migration inhibitory factor (MIF), leucocyte migration inhibitory factor (LIF) and blast transformation assays. Primary and secondary responses were differentiated by studying 6 day MLR time courses. Maternal lymphocytes (normal pregnancies) did not show an early, (i.e. secondary), proliferative response, nor did the pattern of LIF release suggest maternal CMI to fetal (paternal) HLA. However, the lymphocyte responses between pre-eclamptic couples, in terms of both proliferation and LIF release, were consistently and significantly different from those of normal couples; a finding which may reflect an abnormal immune response.

Female↗

Numerical analysis of the human fetal heart rate: the quality of ultrasound records.

A method is described for the computerized numerical analysis of fetal heart periods (pulse intervals). It uses a digital filter to separate the record into its high- and low-frequency components and, after removal of baseline variation, identifies accelerations and decelerations of all sizes. It provides an objective method for separating episodes of high heart period variation, normally associated with fetal movements, from episodes of low variation. When Doppler ultrasound is used in the last 10 weeks of gestation, failure time averages 40%. Signal loss is not randomly distributed; it is on average 75% greater during episodes of high heart period variation, although it is not particularly associated with fetal movements as identified by nurse or patient. Nevertheless a comparison of simultaneous direct ECG and ultrasound records shows that the latter provide reasonable statistical measures of heart period variation, and also of accelerations and decelerations provided that signal loss is taken into account. The system thus provides a particularly useful adjunct to the analysis of antenatal human fetal heart rate records.

Abdomen↗

Somatomedin-like activity in cord blood from infants of hypertensive mothers.

Somatomedin-like activity (SLA) was measured by bioassay in cord serum from infants of hypertensive mothers. Levels of SLA were lowest in "light for date' infants with birth weights below the 3rd centile, but did not correlate with birth weight, placental weight or maturity at delivery. Cord serum from female infants had significantly (P less than 0.001) higher levels of SLA than male infants. No differences in SLA were found between infants born after spontaneous labor or following induction.

Birth Weight↗

The expression of major histocompatibility antigens by human chorionic villi.

Frozen sections of human placentae taken at selected stages throughout gestation were stained with monoclonal antibodies to HLA-A, B, C and DR antigens, using an indirect immunoperoxidase technique. No staining of villous trophoblastic tissue was detected. Antibody to HLA-A, B, and C antigens clearly stained membranous elements of the villous stroma. Antibody to HLA-DR antigens stained rare, elongated cells of the villous stroma in the term placenta. Monoclonal antibodies to syncytiotrophoblast membrane were used as a control. This antigen distribution was confirmed by absorption of these monoclonal antibodies in an indirect radioimmunoassay. Adult spleen homogenate gave much stronger absorption than a trophoblast membrane preparation with antibodies to HLA-A, B, C or DR antigens. The opposite absorption pattern was observed with the anti-trophoblast monoclonal antibodies. Detergent solubilisation did not affect the absorption capacity of trophoblast membrane for HLA-A, B, C or DR antigens. Maternal antibody could be eluted from trophoblastic areas of term placental sections by washing at physiological pH, but this did not effect the binding of monoclonal antibodies. Thus the HLA antigens were not masked by preformed maternal alloantibody. These observations confirm that chorionic villous trophoblast does not express detectable HLA antigen. This may be the principal reason for the lack of rejection of the fetal allograft.

Absorption↗

Prediction of small-for-dates infants by measurement of symphysial-fundal-height.

A standard chart of symphysial-fundal height from 20 to 40 weeks of pregnancy was derived from measurements in 103 women who were delivered of infants weighing between the 25th and 90th centile for gestation. The chart was used to predict birth weight in a group of 138 high-risk patients. Thirty (73.1 per cent) of 41 infants with birth weight for gestation less than 10th centile could be detected by this one clinical measurement. A single measurement was most accurate for detecting low birth weight for gestation at 32 to 33 weeks. It is suggested that symphysial-fundal height measurements should be made routinely on all antenatal patients and that each obstetric unit should derive its own standard curves.

Anthropometry↗