Search PubMed⌕ Search

Biomedical subjects

S R Plymate

Publications and source records attributed to S R Plymate.

At least 73 records · Page 4Linked to original sources
PubMed1987

Laboratory evaluation for Cushing's syndrome in psychiatric patients with cortisol nonsuppression following the overnight dexamethasone suppression test.

Laboratory tests used for the differential diagnosis of Cushing's syndrome have infrequently been employed in investigations of psychiatric patients who demonstrate hypothalamic-pituitary-adrenal (HPA) overactivity, and these laboratory procedures have not previously been applied for the specific purpose of further evaluating the endocrine function of psychiatric patients with serum cortisol nonsuppression following the standard 1-mg overnight Dexamethasone Suppression Test (DST). Low-dose (4 mg/48 hr) and high-dose (16 mg/48 hr) DSTs were administered to 10 psychiatric patients who exhibited cortisol nonsuppression after the overnight DST. Patients all had normal suppression to both the low-dose and high-dose tests. HPA overactivity in these patients was thus not sufficient to meet laboratory criteria for the diagnosis of Cushing's syndrome. Study results suggest that psychiatric patients with abnormal cortisol suppression following the 1-mg overnight DST are likely to have normal responses when assessed by standard laboratory protocols used for the diagnosis of Cushing's syndrome.

Adrenocortical Hyperfunction↗
PubMed1987

The use of sperm penetration assay in evaluation of men with varicocele.

In order to study the ability of the sperm penetration assay (SPA) to correctly classify the fertility status of men, we prospectively examined the results of the SPA performed on the semen of three groups of men of known fertility status. The groups included 67 normal men without varicoceles whose wives were pregnant (VARN), 51 men with a palpable varicocele whose wives were pregnant (VARF), and 30 infertile men with varicoceles (VARI). Two SPAs were done on each subject. Ninety-seven percent of the VARIs showed less than 15% penetration on a single test, and 91% showed less than 15% on both tests. On a single test 61% of the VARNs and 68% of the VARFs were less than 15%. If 0 penetration were used as the criteria of infertility, then 40% of the VARIs, 27% of the VARFs, and 12% of the VARNs would be classified as being infertile. These data suggest that the SPA cannot independently define male fertility status and should be used in conjunction with the standard semen analysis and clinical evaluation of the couple to assess male fertility potential.

Female↗
PubMed1987

Central hypogonadism in burned men.

Serum samples were obtained from 30 burned men at different times up to the fourth month after injury. Mean concentrations of estradiol (E2) were elevated above those for healthy control subjects. Mean serum total testosterone (T), sex hormone-binding globulin (SHBG), bioassayable luteinizing hormone (LH), thyroxine (T4), triiodothyronine (T3) and their free indices (FT4I and FT3I) were depressed below those of controls during the first postburn week. Mean values for T and LH were progressively higher in samples taken from later time periods but remained depressed. Mean SHBG and thyroid hormones rose and were not significantly different from control values during later periods of the study. Calculated non-SHBG-bound T (NSBT) was below normal in each time period. The close correlation of SHBG values with those of T3 and FT3I in the patients suggests that SHBG responds to the altered thyroid hormone milieu of burn injury. It is postulated that elevated serum E2 perhaps from adrenal precursors promotes an alteration of hypothalamic function resulting in a markedly reduced secretion of bioactive LH and diminished Leydig cell function.

Adolescent↗
PubMed1987

The effects of aging in normal men on bioavailable testosterone and luteinizing hormone secretion: response to clomiphene citrate.

Serum testosterone (T) levels in men decline with age while serum LH levels, as measured by RIA, increase. To assess if the decline in serum T levels in healthy aging men is paralleled by an age-related decline in the bioavailable non-sex hormone-binding globulin (SHBG)-bound fraction of T and to determine whether there are age-related changes in LH secretion or LH control of T production, we studied 29 young (aged 22-35 yr) and 26 elderly (aged 65-84 yr) healthy men. All men had single random blood samples drawn, and 14 men in each age group underwent frequent blood sampling for 24 h, both before and after 7 days of clomiphene citrate (CC) administration. Both mean 24-h serum total T levels and non-SHBG-bound T were reduced in elderly men compared to those in young men (P less than 0.05), while estradiol and SHBG levels were similar in the 2 age groups. Serum FSH determined by RIA and LH by RIA and bioassay were higher in the elderly men compared to those in young men (P less than 0.05), but the ratios of LH bioactivity to immunoreactivity and the LH pulse frequency and amplitude were similar. After CC administration, mean serum total T and non-SHBG-bound levels in young men increased by 100% and 304%, respectively, while in older men these values increased by only 32% and 8%, respectively. However, CC-stimulated LH pulse characteristics and serum levels of estradiol, SHBG, FSH, and bioactive and immunoreactive LH were similar in the 2 groups. Thus, both at baseline and after CC stimulation, elderly men had significantly lower serum total T and non-SHBG-bound (bioavailable) T levels than did young men, despite similar or increased levels of bioactive LH and similar bioactive to immunoreactive LH ratios and LH pulse characteristics. These results suggest that major age-related changes in the hypothalamic-pituitary-testicular axis occur at the level of the testes and are manifested by decreased responsiveness to bioactive LH. Administration of CC to young and elderly men resulted in similar changes in LH pulse characteristics and LH bioactivity and immunoreactivity, suggesting preserved hypothalamic-pituitary responsiveness in the elderly.

Adult↗
PubMed1986

Comparison of gonadal function between fertile and infertile men with varicoceles.

The high prevalence of men with varicoceles who by history are fertile has led some to question the suggested causal relationship between a varicocele and male infertility. However, testicular function in these fertile men has not previously been studied in detail. Fifty-five normal fertile men, 42 fertile men with varicoceles, and 24 infertile men with varicoceles and normal female partners were studied. Semen analyses were done, baseline serum testosterone and gonadotropin levels tested and the gonadotropin response to luteinizing hormone-releasing hormone (LH-RH) measured. The infertile men with varicoceles exhibited lower sperm counts, abnormal sperm morphologic features, increased baseline serum gonadotropins, and increased gonadotropin responses to LH-RH, compared with the normal fertile men. The fertile men with varicoceles showed similar abnormalities, although this was not statistically significant in all cases. That semen and hormone abnormalities were observed in both the fertile and infertile men with varicoceles suggests that the presence of a varicocele is associated with some degree of primary testicular dysfunction, regardless of present fertility status.

Adult↗
PubMed1985

Transient reduction in serum HDL-cholesterol following medroxyprogesterone acetate and testosterone cypionate administration to healthy men.

Serum lipids were examined in thirty normal male volunteers who had received depo-medroxyprogesterone acetate (DMPA) and testosterone cypionate (TC) in a male contraceptive trial. Progestagens have been implicated in the changes in serum lipids observed in women using oral contraceptives and this has led to concern about cardiovascular health risks associated with the long-term use of some of these preparations. The following study was done to determine if similar effects occur in men. The men in this study were divided into three DMPA dose groups (50, 100, 200 mg/month) and received intramuscular injections for six months; all men received 250 mg/month TC. There was no significant change in serum high density lipoprotein-cholesterol (HDL-C) levels during the six months of drug administration when compared to levels in the control period. However, there was a marked decrease in HDL-C during the first three months after discontinuation of the drugs (p less than 0.02). This observed change was consistent in each of the three DMPA dose groups but no dose relationship was observed. There was no statistically significant change in serum concentrations of total cholesterol, low density lipoprotein-cholesterol, triglycerides or insulin in any period of the experiment. Serum testosterone (T), estradiol, and sex hormone binding globulin (SHBG), luteinizing hormone (LH), and follicle stimulating hormone (FSH) concentrations were all significantly depressed during the drug administration period. A progestagen dose relationship was observed only for the decrease in serum testosterone and LH concentrations. Serum T and SHBG levels were still significantly reduced at 4-6 months after cessation of the drug administration. These findings demonstrate that DMPA can cause a reduction in serum HDL-C levels. It is suggested that HDL-C concentrations fell only following DMPA withdrawal as a consequence of steroid hormone changes specific to this period.

17-alpha-Hydroxyprogesterone↗
PubMed1985

Sex hormone-binding globulin changes during the menstrual cycle.

Although sex hormone-binding globulin (SHBG) production is stimulated by estrogen, no change in SHBG has been demonstrated during the menstrual cycle. To further study possible cyclic changes in serum SHBG, 12 women with a normal menstrual and fertility history had daily SHBG measurements during a menstrual cycle. SHBG was measured by dextran-coated charcoal saturation analysis and RIA. Serum LH was measured by mouse Leydig cell bioassay and RIA, and FSH, estradiol (E2), and progesterone were determined by RIA. In 10 women, a significant increase in mean SHBG by both methods occurred during the luteal phase of the cycle, immediately after the preovulatory increase in serum E2 (P less than 0.001). Two women had no SHBG increase; although each had a significant rise in serum E2 before the LH surge, luteal phase E2 levels were similar to those in the early follicular phase. In one of these women, a rise in SHBG was demonstrated by RIA. This study demonstrates that SHBG changes during the menstrual cycle in association with E2 changes, and it appears to be a marker for the endogenous estrogen changes that occur in normal ovulating women.

Adult↗
PubMed1984

Relationship between sex hormone binding globulin and estrogen receptors in breast cancer.

It has been suggested that the level of sex hormone binding globulin (SHBG) is a better predictor of response of breast cancer to hormone treatment than the measurement of estrogen receptor (ER). However, no correlation of SHBG with ER status has been shown. To define the relationship between SHBG and the ER, the following study was undertaken. Fifty women with breast cancer and known ER status had SHBG measured by dextran-coated charcoal saturation analysis. The mean SHBG in all ER-positive patients was 20.7 +/- 2.4 (ng DHT bound/mL) and in all ER-negative patients was 11.5 +/- 2.0 (p less than 0.01). The mean premenopausal level of SHBG was 22.2 +/- 3.8 ng/mL and postmenopausal level was 20.0 +/- 5.7 ng/mL. There was no significant difference between these groups. ER-positive patients on tamoxifen had a SHBG of 29.8 +/- 9 ng/mL and ER-negative subjects on tamoxifen had a mean SHBG level of 8.3 +/- 3.4 ng/mL, p less than 0.01. ER-positive patients have a higher SHBG level than ER-negative patients; furthermore, this difference between ER-positive and ER-negative subjects was further demarcated by changes in SHBG after the subjects had been placed on tamoxifen.

Adult↗
PubMed1983

Sex hormone-binding globulin changes with androgen replacement.

Since sex hormone-binding globulin (SHBG) levels are often elevated in sera of patients with testicular insufficiency, it is important to determine whether SHBG declines into the normal range and the extent of change in free testosterone (free T) after androgen administration. Five normal men and five patients with Klinefelter's syndrome were studied before and after the administration of testosterone enanthate (200 mg, im every 2 weeks). An additional five normal men and five patients with hypogonadotropic hypogonadism (HH) were treated with hCG (2000 U, three times a week). Three months after the administration of T or hCG, serum total and free T increased in both normal men and patients. Free T increased significantly in the Klinefelter's and HH patients from 94 +/- 20 and 14 +/- 5 pg/ml, respectively, to 271 +/- 50 and 276 +/- 41 pg/ml (P less than 0.01; P less than 0.001). The increase in the normal men treated with T or hCG was also significant (from 211 +/- 52 and 220 +/- 37 pg/ml to 390 +/- 83 and 330 +/- 90 pg/ml). SHBG fell in both the T-treated normal men (from 6.5 +/- 1.2 ng dihydrotestosterone bound/ml to 4.3 +/- 0.4; P less than 0.02) and the T-treated Klinefelter's patients (from 16.4 +/- 2 to 4.3 +/- 0.5; P less than 0.01). However, it was unchanged in the hCG-treated HH patients and rose in the hCG-treated normal men (from 6.6 +/- 0.7 to 8.6 +/- 1.0; P less than 0.05). This study demonstrates that treatment of hypogonadal men with T and hCG in the doses used increased free T levels above the basal levels for normal men. However, the effects of the increase in free T, as determined by a change in SHBG, were different depending upon the type of treatment.

Adult↗
PubMed1981

Seminal characteristics in the presence of a varicocele as compared with those of expectant fathers and prevasectomy men.

One hundred and thirty-one semen analyses were performed on men found to have a varicocele on a routine physical examination. The seminal characteristics of these men were contrasted with those of 87 men who were desirous of having a vasectomy and with those of 25 expectant fathers. No significant differences were found in the mean sperm density in these three groups of men. However, it was noted that a greater percentage of men with a varicocele had a sperm count of 20 million or less as compared with the control groups. It was also found that a greater percentage of the men with either a large or medium-sized varicocele had a sperm count of 20 million or less than those with a small varicocele. There was no significant difference in the percentage of oval forms, motility, or tapered forms in the three groups of men with a varicocele as compared with expectant fathers and men desirous of a vasectomy.

Adolescent↗
PubMed1981

Obesity and its role in polycystic ovary syndrome.

To examine the mechanism by which obesity influences ovulation, 55 patients with oligo- or anovulation were studied. Parameters measured in serum were sex steroid-binding globulin (SSBG), testosterone (T), PRL, LH, FSH, and estradiol (E2). The women were divided into 2 groups: an obese group (group 1), greater than 145% of ideal body weight, and a normal weight group, less than 120% ideal body weight. SSBG was measured by saturation analysis T, LH, FSH, PRL, and E2 were measured by RIA. SSBG group 1 levels were 7.14 ng dihydrotestosterone bound/ml compared to 14.7 ng dihydrotestosterone bound/ml in group 2 (P less than 0.05). There were no significant differences in FSH, T, or E2. The correlation of body weight vs. SSBG in all patients was r = -0.62. In these 2 groups, the SSBG was significantly lower in the obese patients compared to that in the normal weight patients, independent of T or E2 levels. SSBG correlated negatively with body weight, suggesting that obesity has an influence on SSBG levels independent of hormonal status. When SSBG is lowered, there may be an increase in free T which, by inhibiting follicular maturation, may begin the sequence of events seen in polycystic ovary syndrome.

Female↗
PubMed1981

Sperm penetration assay: useful test in evaluation of male fertility.

The recently developed sperm penetration assay (SPA) tests the functional capacity of sperm. It is based upon the ability of in vitro capacitated human spermatozoa to penetrate zona-free hamster eggs in vitro. The SPA was superior to seminal fluid analysis in predicting both fertility and infertility; in the prediction of infertility, the difference was highly significant. Data further indicated that fertility in the male may not remain constant with the passage of time. The SPA would appear to have wide application both clinically and experimentally.

Animals↗
PubMed1980

Leydig cell dysfunction and gynaecomastia in adult males treated with alkylating agents.

Three adult males presented with gynaecomastia, small testes and clinical features of androgen deficiency after treatment with alkylating agents. Laboratory evaluation revealed elevated serum follicle stimulating hormone and luteinizing hormone. Serum testosterone oenanthate relieved the symptoms of androgen deficiency in addition to reducing the size and tenderness of the gynaecomasia. It is postulated that in addition to the well documented effects of alkylating agents on the seminiferous tubules, a state of 'compensated Leydig cell dysfunction' in induced. The relative decrease in serum testosterone and concomitant lowering of the testosterone to oestrogen ratio may act as a stimulus for breast development. Therefore, treatment with exogenous testosterone would be expected to be effective.

Aged↗
PubMed1980

Thyroid uptake of 123I in a normal population.

Iodine 131 for thyroidal uptake and scan exposes the thyroid to potentially carcinogenic doses of radiation. Iodine 123, on the other hand, compares equally with 131I for uptake studies yet reduces thyroid radiation exposure substantially. Reported fluctuations in normal thyroidal iodine uptake over the past decade, as well as possible radiation injury with 131I, prompted examination of uptake values in a normal population using 123I. The normal range defined in 100 euthyroid subjects was 1% to 8.8% at two hours, and 4% to 27% for the 24-hour uptake. These results are significantly lower than observed eight years ago in this area. No relationship was noted between uptake values and thyroid indices, age, sex, ponderal index, estrogen ingestion, or urinary iodine excretion. Purified 123I appeared to provide clinically reliable results with a substantial reduction in potential radiation injury.

Female↗