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Biomedical subjects

T Chard

Publications and source records attributed to T Chard.

At least 361 records · Page 20Linked to original sources
PubMed1977

Plasma human placental lactogen profiles over 24 hours in normal and diabetic pregnancy.

Plasma human placental lactogen (HPL) concentrations have been measured at frequent intervals over 24 hours in 24 normal women, 13 chemical and 13 insulin dependent diabetic patients during the third trimester of pregnancy. Most of the women studied displayed variation in HPL levels during the day, but there was no evidence of a diurnal rhythm, nor significant changes following meals or during the nocturnal fast. The mean plasma HPL concentrations over 24 hours in the chemical and insulin dependent diabetic patients (5-9+/-SD 1-3 and 5-9+/-1-7 microng/ml respectively) were greater than those in normal women (5-1+/-1-2 microng/ml) but this difference was not significant. No significant change in plasma HPL concentrations was observed during a five-hour oral glucose tolerance test in either the normal or chemical diabetic group. It is suggested that in normal pregnant women HPL does not itself contribute to glucose homeostasis but acts as a 'regulator' which alters the actions of certain maternal hormones to achieve a favourable environment for fetal growth.

Adult↗
PubMed1977

alpha-Fetoprotein levels in pregnancies complicated by gastrointestinal abnormalities of the fetus.

alpha-Fetoprotein (AFP) levels have been measured in maternal serum and amniotic fluid in a variety of gastrointestinal abnormalities of the fetus. Maternal serum AFP levels were consistently elevated in abdominal wall defects of the fetus after 15 weeks gestation and the amniotic fluid levels were raised in 3 of the 4 patients measured. In atresia of the gastrointestinal tract and diaphragmatic hernia, serum AFP levels were usually normal unless there was an associated neural tube defect or multiple pregnancy, although the majority were not measured between 15 and 26 weeks gestation. If elevated amniotic fluid levels of AFP are used in the decision to terminate pregnancy on the assumption of a probable neural tube defect of the fetus, a proportion of terminations will be performed because of abdominal wall defects of the fetus.

Abdominal Muscles↗
PubMed1977

A comparative study of plasma 17beta-oestradiol, progesterone, placental lactogen and chorionic gonadotrophin in abortion induced with intra-amniotic prostaglandin F2alpha.

Serial estimations were made in plasma of 17beta-oestradiol (E2), progesterone and human placental lactogen (HPL) in 43 patients and of human chorionic gonadotrophin (HCG) in 34 patients during mid-trimester abortions induced with intra-amniotic prostaglandin F2alpha (PGF2alpha. Mean plasma concentrations of all the hormones showed a progressive fall after PGF2alpha. There was no relationship between the fall in levels of progesterone, HPL and HCG and the induction-abortion interval, signs of fetal distress or of intrauterine fetal death. Both the control level and the rate of fall of E2 were related to the induction-abortion interval and a rapid decline preceded intrauterine fetal death. The relationships of the progesterone/E2 ratio and the amniotic fluid volume/progesterone ratio to the induction-abortion interval were examined. The variation in the time at which significant falls in the concentration of individual hormones occurred was probably related to their respective half-lives in plasma.

Abortifacient Agents↗
PubMed1977

Screening for fetal neural tube defects by maternal plasma alpha-fetoprotein determination.

A total of 5539 consecutive pregnant patients at three maternity units in the City and Hackney District of London were screened for fetal neural tube defect by measurement of maternal plasma alpha-fetoprotein (AFP) levels. Only 25-7% of women booked at 16 to 22 weeks, the optimum time for this screening test; 54-1% booked before 16 weeks and 20-2% after 22 weeks. Of the women tested before 23 weeks, 300 had elevated levels of AFP in plasma and 14 of them had fetuses with abnormalities known to cause a rise in AFP levels (12 fetuses had a neural tube defect and 2 had alimentary tract abnormalities). Of women examined before 23 weeks, half of those with twin pregnancies had elevated levels of plasma AFP as did 16-7% of those who ultimately had a spontaneous abortion.

Abortion, Spontaneous↗
PubMed1976

Observations on maternal oxytocin release during human labor and the effect of intravenous alcohol administration.

Serial blood samples were obtained from 97 women in spontaneous labor, and oxytocin levels were determined by a sensitive and highly specific radioimmunoassay. The following observations were made: (1) The hormone is released in a series of "spurts"; (2) the peak levels achieved are usually 2 to 5 muU per milliliter and never exceed 12.5 muU per milliliter; (3) the frequency of spurt release increases as labor progresses, reaching a maximum in the second stage; (4) the frequency of spurt release is reduced during intravenous infusion of alcohol at levels which produce no obvious effect on uterine activity.

Ethanol↗
PubMed1976

A new method for estimation of fetal weight in late pregnancy by ultrasonic scanning.

The biparietal diameter and are of the fetal skull, and the area of the fetal thorax, were measured by ultrasonic scanning in 68 patients in the seven days prior to delivery. These parameters and various expressions based on the skull and thoracic areas were related to birth weight. It was concluded that the skull and thoracic areas multiple (STAM) index was a more efficient predictor of birth weight than the biparietal diameter.

Anthropometry↗
PubMed1976

Amniotic fluid levels of fibrin(ogen) degradation fragment E and alpha-fetoprotein in normal pregnancy and with fetal neural tube defect.

Amniotic fluid levels of alpha-fetoprotein (AFP) and fibrin(ogen) degradation fragment E (FgE) were measured in 214 normal subjects and 27 pregnancies associated with an abnormal fetus (open neural tube defect or exomphalos). AFP levels showed no overlap between the normal and abnormal groups, thus confirming the reliability of the AFP assay in the detection of these abnormalities. FgE levels however showed considerable overlap and could not be used as a diagnostic parameter. Agarose gel chromatography of the amniotic fluid revealed the presence of large molecular weight FgE related antigen in open neural tube defect suggesting that leakage of proteins from exposed capillaries is responsible for the elevation of amniotic fluid protein levels.

Amniotic Fluid↗
PubMed1976

Location of the protein hormones of the placenta by the immunoperoxidase technique.

An attempt has been made to locate human placental lactogen (HPL) and human chorionic gonadotrophin (HCG) in cells within the human term placenta. Using immunoperoxidase techniques on frozen sections of tissue, no difference could be found between specific antisera and control sera. A theory is put forward that it may not be possible to visualize these hormones in the placenta using present immunoperoxidase techniques.

Chorionic Gonadotropin↗
PubMed1976

Circulating levels of fibrin/fibrinogen degradation fragment E measured by radioimmunoassay in pre-eclampsia.

Levels of fibrin/fibrinogen degradation products have been measured by a sensitive and specific radioimmunoassay in pregnancies associated with pre-eclampsia or essential hypertension. The incidence of elevated levels was low (2-4%) in mild and moderate cases, and rather higher (30%) in severe cases. In no patients were the levels consistently elevated prior to the onset of clinical signs.

Female↗
PubMed1976

Alpha-fetoprotein levels in maternal plasma and amniotic fluid during prostaglandin-induced mid-trimester abortions: the relation to fetal distress and death.

Alpha-fetoprotein (AFP) levels were measured in both plasma and amniotic fluid during 43 abortions induced with prostaglandin F2alpha (PGF2alpha) and their relationship to the induction-abortion interval and signs of fetal distress or intrauterine death examined. The mean plasma AFP levels showed a progressive rise after PGF2alpha administration but abnormally high levels were found infrequently until the time of delivery. Feto-maternal bleeding could explain the abnormally high plasma AFP levels which occurred early in a few cases. A shorter induction-abortion interval was found in patients with normal plasma AFP levels. Neither fetal distress nor intrauterine death were associated with abnormally high plasma AFP levels. No change in AFP levels in amniotic fluid was found.

Abortion, Induced↗
PubMed1976

Conditions for collection of serum samples for the measurement of fibrin(ogen) degradation products by radioimmunoassay of fragment E.

A number of conditions have been assessed for the collection of serum samples for the measurement of fibrin(ogen) degradation products using a radioimmunoassay for degradation fragment E, which permits precise quantitation of differences. Blood should be collected using minimal venous occlusion into glass tubes containing 10 mg/ml of epsilon amino caproic acid and allowed to clot at 4 to 20 degrees C for at least 4 hours before centrifugation. The serum may be stored at 4 or -20 degrees C. Samples from patients receiving anticoagulant therapy should be treated with 10 IU of thrombin per ml.

Aminocaproates↗