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Biomedical subjects

D Turner

Publications and source records attributed to D Turner.

At least 163 records · Page 9Linked to original sources
PubMed1976

Pituitary and testicular response to hypothalamic LH-releasing hormone (LH-RH) in normal and oligospermic men.

A comparative study was done of the basal and post-LH-RH stimulation levels of LH, FSH and Testosterone (T) in 10 healthy, male volunteers, aged 24-35 years, and in 25 normogonadotropic oligospermic men aged 23-43 years in whom other endocrine, urologic and/or vascular diseases had been rules out. Seventeen of the latter group underwent bilateral testicular biopsy. Each subject received rapid i.v. injection of 50 mug synthetic LH-RH at 8:00 A.M. Serum levels of LH, FSH and T were determined by radioimmunoassay on samples obtained immediately before and 30 and 45 minutes after injection. As compared to normals, oligospermic men had a lower average LH response, although the basal values did not differ significantly from normal. FSH levels did not differ significantly between groups, although some individual patients showed higher and some lower than normal values. The possibility of stimulating T secretion with LH-RH was confirmed. Average serum T levels rose more slowly and reached lower levels in the oligospermic men than in normal men. There was no correlation between LH and FSH rises. It is postulated that some patients with normogonadotropic oligospermia may have latent insufficiency of pituitary gonadotropic functional reserve for one or both hormones and/or of the Leydig cell function. The need for individual analysis of results and their correlation with testicular biopsy findings is commented.

Adult↗
PubMed1975

Use of synthetic luteinizing hormone-releasing hormone in treatment of oligospermic men: a preliminary report.

Synthetic luteinizing hormone-releasing hormone (LH-RH) was administered to four normogonadotropic, oligospermic men (24 to 39 years of age) who had no endocrinologic, urologic, or associated vascular disease, to assess its possible therapeutic value in male infertility. Previous testicular biopsies of these subjects indicated alteration of spermiogenesis only. LH-RH (mean dose, 500 mug/day) was administered intramuscularly for 100 to 135 days. Each patient had at least two sperm count before starting therapy and had one every 20 to 30 days during and for two to five months after treatment. The sperm count, semen volume, sperm motility and morphology, and seminal plasma concentrations of fructose and citric acid were studied in each semen sample. In three of the four patients, urinary LH and FSH excretion and plasma testosterone levels were also measured. The sperm count increased clearly in two subjects 30 to 80 days after therapy started; the response was small in the third subject and negative in the fourth. The remaining parameters followed variable courses. Libido increased in all subjects. In the post-treatment period, the two patients who had shown the best response during treatment experienced a new and abrupt increase in the sperm count which remained well above initial values at the end of follow-up. LH-RH appears to be of value in the treatment of certain types of oligospermia, but several issues remain unsettled.

Adult↗
PubMed1975

Response of luteinizing hormone and follicle-stimulating hormone to different doses of synthetic luteinizing hormone-releasing hormone by intramuscular administration in normal and oligospermic men: preliminary report.

The response of LH and FSH levels to intramuscularly administered synthetic LH-RH was studied in two healthy volunteers and three oligospermic patients. Four tests with 50, 100, 250, and 500 mug of LH-RH, respectively, were carried out on each subject at 8 am; the interval between tests was one week. The serum levels of LH and FSH were determined by radioimmunoassay (double-antibody method) before each injection, and 60, 120, 180, and 240 minutes after each injection. No differences in the basal values of either hormone were observed. In both oligospermic and normal men, maximal responses were obtained with doses between 100 and 250 mug. With 500 mug, levels decreased rather than increased. Maximal peaks occurred between 60 and 180 minutes after injection. In the two normal subjects, the responses of LH and FSH were similar. Two of the three oligospermic patients showed discordant responses. From the results, we can assume that LH-RH doses between 100 and 250 mug should be used as a basis for chronic treatment.

Adult↗
PubMed1975

Daily variations of FSH, LH and testosterone response to intravenous luteinizing hormone-releasing factor (LRF) in normal men.

The responses of FSH, LH and testosterone to acute stimulation with synthetic LRF were studied in 6 healthy, fertile men aged 33.4 plus or minus 1.6 yr (X plus or minus SE). Fifty mug of LRF were given, iv at 0600 h, 1200 h, 1800 h and 0000 h, at 1-week intervals, to all 6 volunteers simultaneously. Blood samples were collected by venipuncture before (-5 and 0 min) and 8, 16, 32, 64 and 128 min after LRF injection. Plasma levels of FSH, LH and testosterone were determined by double antibody radioimmunoassay techniques. The responses of FSH and LH to LRF injection showed a clear difference at the times studied. Maximal values were obtained at 0600 h and 1800 h while the response at noon was not significant for LH and absent for FSH. Testosterone secretion showed a clear-cut response to LRF in all the subjects. At three of the four studied times (0600 h, 1800 h, 000 h) plasma testosterone was already increased at 8 min reaching its maximum at 16 min and persisted high until the end of the study. The noon response reached its maximum at the end of the test period. The daily variations of FSH and LH responses to acute LRF stimulation should be taken into consideration in clinical practive and the increment in testosterone secretion makes this test a useful indicator for androgenic testicular reserve.

Adult↗
PubMed1975

Pituitary-gonadal response to acute I.M. stimulation with clomiphene citrate in normal men.

In order to asses the effect of acute i.m. injection of clomiphene citrate (CC) on LH, FSH, and testosterone (T) secretion, five normal, fertile men received 5 mg of the drug dissolved in 2 ml 0.9% saline, while a further five were injected 10 mg of the same preparation. All tests were performed at 8 a.m. Blood samples were drawn at 0, 30, 60, 120 and 180 minutes of the injection. Serum LH, FSH, and T values were determined by the double antibody radioimmunoassay technique. A significant rise of the LH, FSH, and T levels was obtained in both groups. Peak LH values were obtained at 30 minutes (average), whereas FSH and T peaks occurred at 60 minutes. The 180-minute values were similar to basal. The results seem to indicate that intramsucularly administered CC could be useful, as a rapid test, in evaluating the function of the hypothalamic-pituitary-gonadal axis.

Adult↗
PubMed1969

Pathophysiology of post-gastrectomy hypoglycaemia.

The blood glucose and plasma insulin response to oral glucose and slow intravenous infusion of glucose was determined in seven patients who had undergone partial gastrectomy or gastroenterostomy. Similar studies were conducted in normal subjects; in these experiments oral glucose administration was replaced by infusion of glucose direct into the jejunum in order to simulate the rapid gastric emptying which occurs after gastric surgery.Peak insulin levels were much higher after oral or intrajejunal glucose, though peak blood glucose levels were higher after intravenous glucose. Despite the high insulin levels occurring with oral administration the late fall in blood glucose below fasting levels was not significantly greater after oral or intrajejunal glucose than after intravenous administration of the sugar. This does not support the concept that hyperinsulinaemia alone is responsible for reactive hypoglycaemia.

Blood Glucose↗
PubMedDate not supplied

Methodological issues in the development of the Canadian Cancer Incidence Atlas.

The Canadian Cancer Incidence Atlas is among recent national atlases using incidence rather than mortality data. Methods used to assess the significance and spatial correlation of the age-standardized rates (ASIRs) for the 290 census divisions are described. The expected number of cases by area was used to determine cancer sites with sufficient cases to be mapped. ASIR significance was assessed using a simulation based on a Poisson distribution. The consistency of the observed case distributions with the Poisson distribution was examined. The bootstrap confidence interval (CI) for the ASIR developed by Swift was used in the atlas. Spatial correlation was assessed with Moran's I/I(max) and the significance determined by a simulation in order to allow for area population variation. Data quality indicators typically used for cancer registries were presented, supplemented by a registry questionnaire.

Atlases as Topic↗
PubMedDate not supplied

Ophthalmic bioequivalence of steroid/antibiotic combination formulations.

This study compared the relative ocular bioavailability in rabbits of the antibiotic/steroid combination of 0.3 per cent tobramycin and 0.1 per cent fluorometholone acetate to each of the two single-entity products. Two separate studies were conducted, one measuring fluorometholone acetate in cornea and aqueous humour through 240 min and the other measuring tobramycin in the cornea through 120 min. The results for fluorometholone acetate show that the combination product is 15 per cent higher in AUC for the cornea than the single-entity product (0.05 less than p less than 0.1). However, the combination product is only 4.4 per cent higher in AUC when aqueous humour levels are compared (N.S.). The single-entity fluorometholone acetate ointment yielded cornea and aqueous humour levels which were 20 per cent (p less than 0.01) and 6 per cent (N.S.) higher in AUC than the same tissues measured after topical instillation of the suspension. Statistical treatment of the data indicated that the suspension and ointment products, were bioequivalent with respect to fluorometholone acetate in aqueous humour, but not with respect to corneal concentrations. Tobramycin was measured in the cornea following instillation of either the single-entity solution or the combination suspension. Per cent bound (tobramycin to rabbit antibodies determined in vitro from the radioimmunoassay results) was used for statistical analyses of all group means and standard errors. The results indicated that the products were bioinequivalent.

Animals↗