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Biomedical subjects

G D Carter

Publications and source records attributed to G D Carter.

36 records · Page 2Linked to original sources
PubMed1989

The diagnosis of polycystic ovaries in subfertile women.

Laparoscopy was used to identify the polycystic ovary (PCO) in a group of subfertile women. A third were found to have PCO. These patients had higher levels of luteinizing hormone (LH), testosterone (T) and a higher free androgen index (FAI) than those with normal ovaries. Only 15% of patients with laparoscopic evidence of PCO were obese, hirsute and oligomenorrhoeic. Within the PCO group, hirsutism was strongly associated with obesity and a high FAI. A group of subfertile women with PCO and regular cycles was found who had no other identifiable cause for their infertility. These women had higher follicular phase concentrations of LH and higher FAI than ovulatory women with normal ovaries.

Adult↗
PubMed1989

Insulin-like growth factor 1 as an intra-ovarian hormone--an integrated hypothesis and review.

Fourteen ovulatory patients undergoing diagnostic laparoscopy had at least 2 samples of clear follicular fluid (FF) collected in the late follicular phase. Dominant follicles contained significantly higher concentrations of insulin-like growth factor-1 (IGF1), oestradiol (E2), progesterone (P) and lower androstenedione (AD) than their matched cohorts. After the luteinizing hormone (LH) surge, a significant increase in dominant FF-IGF1 and FF-P occurred. Log FF-E2 and log FF-P were correlated with both FF-IGF1 and FF volume. Log FF-AD was negatively correlated with FF-volume, FF-E2 and FF-P (but not FF-IGF1). The cohort concentration of FF-IGF1 was correlated with serum IGF1. These results support the hypothesis that IGF1 has a central role in the selection of the dominant follicle.

Adult↗
PubMed1989

The effect of clomiphene citrate on follicular phase increase in endometrial thickness and uterine volume.

Fifteen ovulating women had serial ultrasound scans to measure follicular, endometrial, and uterine growth, as well as biochemical indices including estradiol (E2) and the free androgen index, throughout a natural and a clomiphene-citrate-induced cycle. Despite higher E2 levels in the 5 days preceding ovulation, the clomiphene cycles were characterized by absence of the normal increase in uterine volume and an inhibition of endometrial thickening. It is proposed that the anti-estrogen effect of clomiphene inhibits the normal cyclical growth of the uterus and endometrium.

Adult↗
PubMed1988

A comparison of follicular fluid levels of insulin-like growth factor-1 in normal dominant and cohort follicles, polycystic and multicystic ovaries.

Fourteen ovulatory patients undergoing diagnostic laparoscopy had at least two samples of clear follicular fluid (FF) collected in the late follicular phase. The cohort concentrations of Insulin-like Growth Factor-1 (IGF1) were significantly correlated with serum IGF1 and dominant follicles contained significantly higher concentrations of IGF1 and oestradiol (E2) than their cohorts. After the LH surge, a further significant increase in dominant FF-IGF1 occurred. FF-(log)E2 was significantly correlated with both FF-IGF1 and FF volume. Nine women with the polycystic ovary syndrome (PCOS) and one patient with multicystic ovaries (MCO) associated with weight-loss related amenorrhoea also had follicular aspiration performed. The mean (SD) FF-IGF1 in the PCOS group, 0.42 (0.15) U/ml, was not significantly different from that of the cohorts in the control group, 0.39 (0.13) U/ml. The patient with MCO had both serum and FF-IGF1 concentrations less than 10th centile. These results support the hypothesis that IGF1 has a paracrine (and possibly endocrine) role in the regulation of ovarian function in the human female.

Adult↗
PubMed1988

What are the ultrasound and biochemical features of impending ovulation?

Thirty-two ovulatory women had serial ultrasound measurements of uterine volume, endometrial thickness and leading follicular diameter compared with serum oestradiol, testosterone and sex-hormone binding globulin. Follicular diameter, endometrial thickness and uterine volume were significantly correlated with serum oestradiol. The day before ovulation was characterized by maximal values for oestradiol, testosterone, luteinizing hormone, endometrial thickness, uterine volume and leading follicular diameter. Leading follicular diameter and endometrial thickness in particular, appear to be useful parameters to indicate impending ovulation.

Endometrium↗
PubMed1988

Elevated free androgen index as an indicator of polycystic ovaries in oligomenorrhoea without obesity or hirsuties.

A group of oligomenorrhoeic women without obesity or hirsuties was investigated with high-resolution ultrasound, laparoscopy and biochemical parameters. In this series, polycystic ovaries (PCO), as defined by ultrasound and laparoscopy, are a common cause of oligomenorrhoea in women without the classic symptoms, and were strongly associated with an elevated free androgen index (FAI). Despite an elevated FAI, these women were not hirsute, It would seem reasonable to include a FAI in the investigation of the oligomenorrhoeic woman, along with the more 'standard' tests, such as thyroid function and a prolactin level.

Adult↗
PubMed1988

Factors influencing the free androgen index in a group of subfertile women with normal ovaries.

Eighty-five regularly cycling women with normal ovaries at laparoscopy, were studied to determine the factors that influence the free androgen index (FAI). It was found that body mass index (BMI), age of the patient and the phase of the menstrual cycle that the blood was collected can all affect the FAI. It is recommended that where possible, specimens should be collected in the early follicular phase to avoid misinterpretation of the result.

Age Factors↗
PubMed1988

Oestradiol assays: applications and guidelines for the provision of a clinical biochemistry service.

This paper reports on the provision of a clinical biochemistry service for serum oestradiol. The pathophysiology and recognised applications of oestradiol assays are discussed and the current availability of assay reagents and methodologies reviewed. Data are presented on the analytical performance of assays for serum oestradiol in the UK External Quality Assessment Scheme (UKEQAS) and general guidance is offered to laboratories providing a diagnostic service for this analyte.

Adult↗
PubMed1987

Hereditary angioedema and thyroid autoimmunity.

Sera from 91 patients with hereditary angioedema were screened for thyroid antibodies. The results for the 77 patients more than 17 years old were compared with previously published data for the prevalence of thyroid disease in a large community (Whickham). Of the female patients with hereditary angioedema, the prevalence of thyroglobulin antibodies (TGA) was 14.0%, higher than the expected 3% (p less than 0.001). The prevalence of thyroid microsomal antibodies (TMA) was 20%, also higher than the expected 7.6% (p less than 0.01). The age distributions of the females in both groups differed: in the group with hereditary angioedema there was a greater proportion of younger patients which should have resulted in a lower prevalence of thyroid antibodies. Adjusting for related patients with hereditary angioedema, there was still an increased prevalence of TGA (p less than 0.01) and TMA (p less than 0.01).

Adolescent↗
PubMed1986

Oral spironolactone: an effective treatment for acne vulgaris in women.

The effect of oral spironolactone (200 mg daily) on acne vulgaris has been studied in 21 women in a randomized, placebo-controlled, double-blind crossover study using 3 month treatment periods. Compared with placebo, spironolactone produced significant improvement as assessed by subjective benefit (P less than 0. 001), number of inflamed lesions (P less than 0 . 001) and by an independently evaluated photographic method (P less than 0 .02). There was a fall in sex hormone binding globulin but no significant changes in plasma testosterone and derived free testosterone. Initial plasma androgen levels were no higher in responders than in non-responders, nor did oral contraceptive use appear to affect clinical response. Spironolactone is a useful alternative therapy for women with acne vulgaris.

Acne Vulgaris↗
PubMed1985

Association of secondary hyperparathyroidism with red cell survival in chronic haemodialysis patients.

51Cr red cell mass (RCM), 51Cr red cell survival (RCS) and plasma parathyroid hormone (PTH) levels were measured in 27 stable chronic haemodialysis patients with a variable degree of clinical secondary hyperparathyroidism. Included were five patients who had had total parathyroidectomy. The results showed a strong negative correlation between PTH and RCS (r = -0.67, P less than 0.001) and a positive correlation between RCS and RCM (r = +0.53, P less than 0.005). However, the negative correlation between PTH and RCM was weak (r = -0.45, P less than 0.02). When the 13 patients with normal PTH levels (mean 0.18 +/- 0.12 microgram/l) were compared with the 14 patients with raised levels (mean 1.35 +/- 0.71 micrograms/l), there was a marked difference in RCS (P less than 0.005) but no difference in RCM.

Adult↗
PubMed1983

The interaction of canrenone with oestrogen and progesterone receptors in human uterine cytosol.

1 Canrenone, the major active metabolite of spironolactone, decreased [3H]-progesterone binding to isolated uterine cytosolic progesterone receptors. The inhibition was concentration-dependent. 2 Canrenone did not alter [3H]-oestradiol binding to isolated uterine cytosolic oestrogen receptors. 3 Canrenone inhibition of progesterone binding to isolated cytosolic receptors was strictly competitive: Kd (apparent dissociation constant for progesterone binding) was increased in a concentration-dependent manner by canrenone, whereas Bmax (maximal number of progesterone binding sites/mg cytosolic protein) was unaltered. There was marked cooperativity in progesterone binding at high canrenone and low progesterone concentrations. The implication is that canrenone alters the subunit interaction of the receptor protein. 4 Kd for progesterone was 3.2 X 10(-9)M. Ki (the inhibition constant for canrenone with respect to progesterone binding) was 300 X 10(-9)M. Reports in the literature suggest that, following spironolactone administration, canrenone may rise to concentrations sufficiently high to inhibit progesterone binding. This action may contribute to the effect of spironolactone in inducing menstrual disturbances in female patients.

Canrenone↗
PubMed1983

Investigation of hirsutism: testosterone is not enough.

In a consecutive series of 41 hirsute women clinically classified as benign androgen excess, only 34% were found to have elevated plasma 'total' testosterone (T), 22% having subnormal sex hormone binding globulin (SHBG). When expressed as the ratio T/SHBG ('free androgen index'), 85% of the patients had values above the normal range. It is concluded that this index is more reliable than total testosterone in assessing androgen status in female patients.

Adult↗
PubMed1981

Double-blind trial of oral 1,25-dihydroxy vitamin D3 versus placebo in asymptomatic hyperparathyroidism in patients receiving maintenance haemodialysis.

Fifty-seven patients who had been receiving maintenance haemodialysis for a mean of 4.6 years were given 0.25-0.5 microgram oral 1,25-dihydroxy (1,25-(OH)2) vitamin D3 or a placebo in a double-blind manner for one to two years. In patients with normal radiographs (mean plasma parathyroid hormone concentration 205 microliterEq/ml) 1,25-(OH)2 vitamin D3 prevented the development of the radiological appearances of hyperparathyroidism. In patients with abnormal radiographs (mean plasma parathyroid concentration 709 microliterEq/ml) 1,25-(OH)2 vitamin D3 arrested or reversed the radiological changes of hyperparathyroidism. Nevertheless, the response was slow and the concentration of the hormone remained considerably raised (mean 445 microliterEq/ml). It is concluded from these results that giving 1,25-(OH)2 vitamin D3 to patients receiving maintenance haemodialysis who have normal hand radiographs or minimal erosions is beneficial. In patients with more advanced hyperparathyroidism parathyroidectomy should be considered unless there is a rapid response.

Adult↗
PubMed1981

Interference by polar metabolites in a direct radioimmunoassay for plasma aldosterone.

The CIS Aldoctk-125 kit, a direct radioimmunoassay for plasma aldosterone, has been compared with a conventional technique involving solvent extraction. Results given by these two methods were poorly correlated (r = 0.445, n = 103), the direct assay giving higher values, particularly in patients being dialysed for renal failure. When the kit was modified to include an extraction step, results correlated well with those of the standard method (r = 0.952, n = 60). These observations suggested interference form polar metabolites. The possibility that glucuronides were responsible was investigated by measuring plasma aldosterone before and after hydrolysis with beta-glucuronidase. Higher post-hydrolysis values confirmed the presence of glucuronides in plasma from normal subjects and patients with renal failure. Preliminary chromatographic studies on plasma form nine dialysis patients indicated the presence of tetrahydroaldosterone 3-glucuronide, and it is thought that this metabolite might contribute to the high values obtained with the direct assay.

Aldosterone↗
PubMed1979

Plasma 25-hydroxy-vitamin D in normal subjects and patients with terminal renal failure, on maintenance haemodialysis and after transplantation.

1. Plasma 25-hydroxy-vitamin D concentration was measured in 40 normal subjects, 19 patients with terminal renal failure, 137 patients who had been on dialysis up to 11 years and in 17 renal transplant patients. 2. The mean plasma concentration of 25-hydroxy-vitamin D was below normal in patients with terminal renal failure and in patients who had been on maintenance haemodialysis for less than 1 year. The mean concentration in patients who had been on dialysis for more than 1 year and in renal transplant patients was normal. 3. The seasonal variation of plasma 25-hydroxy-vitamin D concentration found in the 58 patients on maintenance haemodialysis for more than 2 years is similar to that reported in normal subjects.

Adolescent↗
PubMed1977

Association between exaggerated responsiveness to thyrotrophin-releasing hormone and hypercholesterolaemia.

Thyroid-function tests were performed on one hundred patients with suspected premyxoedema and the results compared with those in twenty age and sex matched controls. The increase in thyroid-stimulating hormone (T.S.H.) in response to thyrotrophin-releasing hormone (T.R.H.) was exaggerated in eighty-eight of the hundred patients with suspected premyxoedema. These included twenty-five with normal basal T.S.H. and sixty-three with a raised basal T.S.H. Serum-cholesterol concentration was significantly higher in those in whom premyxoedema was suspected than in the controls, even when patients presenting with degenerative arterial disease were excluded.

Adult↗