Search PubMed⌕ Search

Biomedical subjects

E M Symonds

Publications and source records attributed to E M Symonds.

At least 127 records · Page 7Linked to original sources
PubMed1982

Effect on low implantation of the placenta on maternal blood pressure and placental function.

Low implantation of the placenta may protect against the development of pregnancy-induced hypertension (PIH) and is associated with improved values in tests of placental function. PIH occurred in six of 201 (3%) consecutive patients with placenta praevia managed at the City Hospital, Nottingham, from 1 April 1973 to 30 June 1981. None of the six patients developed associated proteinuria. Of the total number of 24,549 patients delivered in the same hospital for the years 1974-1978, 3744 (15%) developed PIH. Of the patients with placenta praevia, 52% had serum levels of human placental lactogen above the 95th centile and 25% had 24-h urinary oestriol levels above the 95th centile. The birthweight distribution was not different from that of the total live births at the City Hospital, Nottingham (based on 1975-1976 deliveries).

Adolescent↗
PubMed1982

The effect of captopril (SQ14,225) upon mother and fetus in the chronically cannulated ewe and in the pregnant rabbit.

1. An inhibitor of angiotensin-I-converting enzyme activity (D-3-mercapto-2-methylpropanoyl-L-proline, Captopril) was given to five chronically cannulated pregnant ewes and eleven rabbits in late pregnancy. 2. Within 2 min of administration to the sheep, Captopril had blocked the maternal conversion of angiotensin I to II, as assessed by the pressor response evoked by the i.v. administration of angiotensin I. Maternal and fetal basal systemic blood pressures had fallen within 10 min of administration. Although maternal systemic blood pressure returned to basal levels within 2 hr, fetal pressures remained low for up to 2 days. 3. All ewes went into spontaneous labour at or near term. One lamb was live-born but very weak and failed to establish suckling. The remaining seven lambs were fresh still-births. 4. Gestation length was significantly prolonged in the treated rabbits by comparison with ten controls. The still-birth rate was 37% in the treated animals and 6% in the controls (P less than 0.001). 5. It is concluded that the administration of Captopril to the two species studied is harmful to the fetus. The observations suggest that the drug rapidly crosses the placenta, and may cross the blood-brain barrier to exert a central effect. It may also interfere with the normal initiation of parturition.

Aldosterone↗
PubMed1982

Angiotensin-converting enzyme and the renin-angiotensin system in normotensive primigravid pregnancy.

In a prospective study the interactions between ACE and the renin-angiotensin system in 18 primigravid normotensive women were investigated throughout pregnancy. ACE activity was found to be depressed throughout pregnancy, rising in the last trimester and returning to non-pregnant values by 6 weeks post partum. No significant differences were found between cord arterial or venous and maternal venous ACE levels at delivery. ACE was inversely related to systolic and mean arterial blood pressures, inversely to serum sodium and urinary potassium and directly to serum potassium levels. Within the system, ACE was correlated only to aldosterone levels. In company with other components of the system ACE activity appears to be altered in pregnancy and to be influenced by similar control mechanisms. It is possible that ACE plays a modulating role on aldosterone secretion via the (des-asp1), Angiotensin I pathway.

Birth Weight↗
PubMed1981

A study of angiotensin II binding sites in human placenta, chorion, and amnion.

The binding of tritiated angiotensin II to 20,000 x g particulate tractions of human placenta, chorion, and amnion was investigated. Binding to particles from the three tissues reached equilibrium within 10 minutes at 29 degrees C and was displaced by the addition of 1,000-fold excess of unlabeled angiotensin II. Scatchard analysis of the data showed that two classes of binding sites were present in the placental preparation. For the high-affinity site, values of 9 x 10(-9) M and 300 fmoles/mg of protein were obtained for the dissociation constant and the binding capacity, respectively. There was little specific binding in chorion and amnion.

Amnion↗
PubMed1981

A prospective study of plasma angiotensin-converting enzyme in normotensive primigravidae and their infants.

Plasma angiotensin-converting enzyme (ACE) has been measured prospectively throughout pregnancy, at delivery and in the puerperium in 18 normotensive primigravidae and their infants. Plasma ACE was consistently lower during pregnancy than in comparable, non-pregnant controls, but rose progressively from about 30 weeks to term. At vaginal delivery maternal and fetal ACE levels did not differ significantly. There was a steady increase in maternal ACE activity up to 6 weeks post partum, when the levels were not significantly different from non-pregnant controls. No correlation could be found between plasma ACE and plasma renin activity or concentration, or plasma AII. Plasma aldosterone increased in parallel with ACE during the last ten weeks of pregnancy.

Adult↗
PubMed1981

The titanium/silicone rubber clip for female sterilization.

A composite titanium/silicone rubber clip has been developed for female sterilization. The 12.7 mm long metal clip is lined with silicone rubber and is bent round the Fallopian tube by means of an applicator that can be used laparoscopically. As tubal necorsis occurs, the rubber expands to keep the lumen blocked. The tube eventually divides and the stumps heal closed. Since the Mark 3 version of the clip was introduced, over 5700 women in several countries have been sterilized. The first 540 British women who were followed-up for five to 17 months experienced one method failure (ectopic) and tow operator failures, to total failure rate of 5.5/1000. Clip-related complications were minimal and long-term sequelae were comparable to tubal ligation. The clip causes minimal destruction but still seems effective for tubal occlusion and it can accommodate thick tubes.

Adolescent↗
PubMed1981

Active and inactive renin in human seminal plasma.

The occurrence of renin and renin substrate has been described in human seminal plasma. Mean levels of active and total renin were higher in seminal plasma than in normal male plasma (7.1 compared to 3.8 and 38.5 compared to 24.6 ng/ml/hr, respectively). The differences were not statistically significant. Renin substrate concentrations were very low compared to male plasma levels, which suggests that renin may function either in tissues of the male genital tract prior to secretion into the seminal plasma or may be important following ejaculation in the female genital tract.

Angiotensin I↗
PubMed1980

Progesterone, fluid, and electrolytes in premenstrual syndrome.

Changes in mood, plasma progesterone concentration, urinary volume, sodium excretion, sodium:potassium ratio, and body weight during the menstrual cycle were determined in 18 women with premenstrual syndrome and 10 symptomless (control group) women. Plasma progesterone concentration was higher in the women with symptoms during the postovulatory phase of the cycle, and the peak progesterone concentration appeared earlier. The changes in progesterone concentration were accompanied by a natriuresis and diuresis that fell towards preovulatory values in the premenstrual phase. Sodium retention was not confined to any definite period. Mood symptoms occurred after the changes in progesterone and electrolyte concentrations. Progesterone deficiency is probably not the cause of premenstrual syndrome. Thus treatment with progesterone is probably illogical unless a deficiency is detected. Treatment should be aimed at preventing the natriuretic effect of progesterone in the postovulatory phase and the sodium-retaining and water-retaining effects of aldosterone in the premenstrual phase.

Affect↗
PubMed1980

Tumour markers with unknown functions in gynaecological neoplasia.

Pre- and post-operative ovarian cancer patients' sera were examined for the presence or circulating immune complexes using a variety of assay procedures. In contrast to findings with breast cancer patients' sera, sera from patients with other gynaecological tumours or with preclinical disease diagnosed by cytology, no evidence was obtained to indicate that circulating immune complexes were associated with ovarian cancer.

Antigen-Antibody Complex↗
PubMed1980

Umbilical cord plasma progesterone at term in relation to mode of delivery.

The progesterone concentration in the umbilical venous and arterial plasma has been measured by radioimmunoassay. In 35 normal spontaneous vaginal deliveries the concentration in the umbilical venous plasma was highly correlated with the difference between venous and arterial plasma concentrations. There was no correlation of progesterone levels with infant birth weight or placental weight, but slightly higher amounts were found in samples taken from women with female fetuses than those with male fetuses. There was also a significant correlation of venous progesterone concentration with duration of labour. In 14 subjects where forceps were used to assist delivery because of prolonged second stage labour, progesterone levels were found to be elevated, whereas in nine cases of elective Caesarean section they were reduced. It is suggested that the fetus may stimulate progesterone secretion by the placenta in response to stress and that there may also be a fetal sex-related response.

Birth Weight↗
PubMed1980

Factors affecting plasma angiotensin II concentration in labour.

Concentrations of plasma angiotensin II (AII) have been measured in the second stage of labour or before delivery by elective Caesarean section in 134 women and some factors influencing the levels have been assessed. Plasma AII concentrations in the second stage of labour were higher than levels previously observed before the onset of labour in both primigravid and multiparous women. Markedly lower levels were found following delivery by elective Caesarean section than following vaginal delivery. Multiparae had higher AII concentrations than primigravidae both before the onset of labour and at delivery. Epidural analgesia was associated with significantly lower AII concentrations; in primigravidae receiving such analgesia a statistically significant relation was found between AII concentration and diastolic blood pressure at delivery. A similar relation was found in the nonproteinuric patients delivered by Caesarean section. The estimated duration of the second stage of labour was the major factor affecting AII concentration in normal multiparae. In both primigravid and multiparous women, AII concentrations were markedly raised in association with proteinuria.

Adult↗
PubMed1980

The normal condition of the fetal electrocardiogram during labour.

A real-time computer system was employed to monitor continuously the fetal electrocardiogram (ECG) during labour. Signals from a scalp electrode were amplified, filtered and passed through an interface system to a digital computer. From 110 patients studied, 37 were selected by rigid criteria which fulfilled a strict definition of normal fetal condition in labour and delivery. The mean values and the range of the various parameters of the fetal ECG complex were defined. As a large amount of data was generated by the system, a method was developed to display the short and long-term dynamic behaviour of the fetal ECG during labour in the form of labour profiles. By further averaging of these labour profiles, the pattern of normal behaviour was established. Certain changes in the fetal ECG, previously thought to be characteristic of fetal distress, occurred in normal patients. The P-R interval was up to 10 per cent shorter during contractions towards the end of labour and there was a long-term trend towards the end of labour for the P-R interval to fall by 7 per cent. The P wave amplitude fell by 30 per cent over the last hour. These trends were statistically significant. The QRS complex was found to lengthen slightly towards the end of labour, but the R-T interval and ST segment displacement displayed no significant changes.

Computers↗