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Biomedical subjects

R J Chang

Publications and source records attributed to R J Chang.

At least 91 records · Page 5Linked to original sources
PubMed1982

Enhanced disparity of gonadotropin secretion by estrone in women with polycystic ovarian disease.

The disassociation between serum LH and FSH levels in polycystic ovarian disease (PCO) has been attributed to chronic acyclic estrogen production characterized by a predominance of circulating estrone (E1). This study was designed to determine whether the administration of estrone benzoate (E1B) modulates gonadotropin release in PCO. In five normal women studied during the early follicular phase of a control and subsequent treatment cycle, daily LH and FSH levels were unaltered by E1B administered from days 2 to 6. Gonadotropin responses to LRF given on day 7 were similar during control and treatment cycles. In seven patients with PCO, the mean LH concentration (25.7 +/- 0.7 mIU/ml) and the daily pattern of release were unchanged by E1B administered for 14 days. In contrast, a progressive decline in FSH occurred in each subject. Mean FSH levels decreased significantly from a pretreatment value of 11.3 +/- 0.2 to 9.3 +/- 0.9 mIU/ml by day 2 (P less than 0.05) and 7.2 +/- 1.2 mIU/ml by day 14 (P less than 0.005) of E1B administration. The LH response to LRF in PCO was significantly greater than that observed in the normal subjects, whereas responses before, during, and after E1B administration were similar. The FSH responses to LRF in PCO subjects were comparable to those of the normal subjects. These data indicate that the administration of E1B to PCO subjects reduces FSH levels without altering LH release, thereby enhancing the disparity of gonadotropin secretion encountered in this syndrome. This finding is consistent with the hypothesis that impairment of FSH release by chronic acyclic estrogen production derived from nonglandular aromatization of circulating androgen could in large part be responsible for anovulation in PCO.

Estradiol↗
PubMed1982

"Medical oophorectomy" using a long-acting GNRH agonist--a possible new approach to the treatment of endometriosis.

Five women with endometriosis were given a daily dose of a potent long-acting GnRH agonist, D-Trp6-Pro9-Net-LHRH (GnRH-A) for 28 days in an attempt to suppress ovarian estrogen secretion. The mean level of estradiol (E2) during sampling over 24 hours decreased (P less than 0.01) from 62 +/- 11 to 10 +/- 1 pg/ml at the end of treatment. Mean concentrations of androstenedione, testosterone, estrone and E2 on day 28 of therapy were similar to those measured in oophorectomized women. The level of FSH was decreased (P less than 0.001) during GnRH-a, whereas that of LH was significantly (P less than 0.001) increased, suggesting differing intracellular control mechanisms for release of the two gonadotropins. Desensitization of the pituitary was demonstrated at the end of treatment by a complete lack of acute response of FSH or LH to the daily dose of GnRH-a. "Medical oophorectomy" provides a new approach to the treatment of endometriosis.

Endometriosis↗
PubMed1982

Circulating levels of plasma adrenocorticotropin in polycystic ovary disease.

Excessive adrenal androgen production contributes to hyperandrogenism in polycystic ovarian disease (PCO). This study was performed to determine the concentration of basal plasma ACTH in PCO patients and normal women and correlate its level with that of circulating adrenal androgen. In PCO patients, significant increases in serum testosterone, androstenedione, and dehydroepiandrosterone sulfate were noted compared to levels in normal women. The mean circulating plasma ACTH in PCO patients (22 +/- 2 pg/ml) was not different from that in normal controls (20 +/- 2 pg/ml). The mean ratio of dehydroepiandrosterone sulfate to ACTH in individual PCO patients was significantly greater than that in normal subjects, whereas the cortisol to ACTH ratio was similar in both groups. These results suggest that increased adrenal androgen production in PCO patients is not due to abnormal ACTH secretion but arises from either altered adrenal responsiveness to ACTH or abnormal adrenal stimulation by a factor(s) other than ACTH.

Adrenocorticotropic Hormone↗
PubMed1981

Effect of cimetidine on serum prolactin in normal women and patients with hyperprolactinaemia.

In normal women, intravenous injection of the H2-antihistamine, cimetidine, provoked a 3-4 fold rise in serum prolactin, without changes in serum growth hormone, thyrotrophin, or gonadotrophins. Hyperprolactinaemic patients with pituitary tumours, idiopathic hyperprolactinaemia or hypothalamic lesions demonstrated little or no rise in serum prolactin (expressed as a percentage increment) in response to cimetidine; these responses were significantly more blunted than the prolactin responses to intravenous TRH in the same subjects. Post-partum women also demonstrated blunted percentage prolactin responses to cimetidine, although responses to TRH were, in most patients, normal. Dynamic testing of prolactin secretion with cimetidine is no more useful than TRH in distinguishing tumourous from non-tumourous hyperprolactinaemia.

Adolescent↗
PubMed1981

Anorexia nervosa.

The clinical and physiologic features of anorexia nervosa seem to be consequences of a complex interaction among psychologic abnormalities, endocrine disturbances, and malnutrition. Although a spectrum of psychologic disorders has been observed, distortion of body image, weight phobia, disordered perception of hunger and satiety, and a sense of ineffectiveness are encountered most frequently. The impaired secretion of luteinizing hormone-releasing factor, release of gonadotropins, and production of estrogens reflect a defect in the hypothalamic-anterior pituitary-gonadal axis. Because most of the endocrine abnormalities are reversible with improved nutrition, they are probably secondary to malnutrition rather than to hypothalamic dysfunction. Hypercarotenemia observed in 16 of 21 patients studied recently seems useful in differentiating anorexia nervosa from other forms of malnutrition and weight loss. A combined medical and psychiatric approach has been successful in drastically reducing the mortality of this disorder.

Adolescent↗
PubMed1980

Prolactin-secreting pituitary adenomas. III. Frequency and diagnosis in amenorrhea-galactorrhea.

Hypocycloidal tomograms of the sella turcica and serum prolactin concentrations were obtained in 146 women with amenorrhea, galactorrhea, or both to diagnose prolactin-secreting pituitary adenomas. Findings suggesting an adenoma, ie, abnormal tomogram and elevated serum prolactin concentration, were found in 24.6% (16/65) of previously unscreened patients and 59.2% (48/81) of prescreened patients. The combination of an abnormal tomogram and elevated prolactin level was relatively specific for an adenoma, as 91% (42/46) of women with these findings who underwent surgery had histologically confirmed tumors. Tumors occurred in women from 15 to 45 years of age, with amenorrhea or galactorrhea ranging from less than six months to more than 20 years in duration. Some women in this series also had obesity, rapid weight loss, polycystic ovarian syndrome, amenorrhea following discontinuance of oral contraceptive use, or emotional stress.

Adenoma↗
PubMed1980

Studies on the role of histamine in human pituitary function.

To elucidate further the role of histamine in pituitary regulation, TRH and L-DOPA stimulation tests were performed with and without diphenhydramine, cimetidine, or betazole pre-treatment. Betazole blunted the GH response to L-DOPA and slightly enhanced the T3 response to TRH without altering the TSH or PRL increments. Neither diphenhydramine nor cimetidine had any acute effect on the hormonal responses examined. Histamine apears to play only a limited role in these aspects of human pituitary regulation.

Adult↗
PubMed1979

Elevations in skin temperature of the finger as an objective index of postmenopausal hot flashes: standardization of the technique.

The present study was designed to validate and standardize a technique of continuous recording of skin temperature of the finger as an objective index of hot flashes. Significant skin temperature rises (greater than 1 degree C) were recorded in close temporal relationship to 69% of subjective hot flashes experienced by seven postmenopausal women. The temperature elevations occurred at an interval of 54 +/- 10 minutes (mean +/- standard error) and lasted an average of 31 minutes. The mean increase was 2.7 degrees +/- 0.2 degrees C. The extent of the temperature elevations found in the postmenopausal subjects was significantly greater than in premenopausal control subjects (P less than 0.05) and was reduced by estrogen treatment (P less than 0.02). This study substantiates that the recording of skin temperature changes of the finger provides an objective index of hot flashes. This should assist in the investigation of the underlying disturbance and provide more accurate evaluation of modes of therapy.

Adult↗
PubMed1979

Prolactin-secreting pituitary adenomas in women. II. Menstrual function, pituitary reserves, and prolactin production following microsurgical removal.

A prospective study of 46 women with prolactin-secreting pituitary adenomas and amenorrhea and/or galactorrhea was performed to determine the influence of the selective transsphenoidal removal of these tumors on pituitary and reproductive function. This procedure was effective in restoring menstrual function in 34 of 41 women and in eliminating lactation in 30 of 40 women. Tumor size and preoperative serum prolactin concentrations were the most important factors in predicting the postoperative disappearance of symptoms. Normal menstrual function returned in 33 of 34 women with tumors less than 2 cm in diameter but in only one of seven women with tumors greater than 2 cm. Similarly, galactorrhea disappeared in 29 of 34 women with tumors less than 2 cm but in only one of six women with larger tumors. Menses returned in 31 of 32 women and galactorrhea disappeared in 25 of 31 women with preoperative serum prolactin levels below 200 ng/ml; conversely, menses returned in only three of nine women and lactation ceased in one of six women with preoperative serum prolactin concentrations above 200 ng/ml. Prolactin concentrations decreased in 42 of 43 patients following the removal of pituitary adenomas and returned to normal in 30. Postoperative pituitary reserves of adrenocorticotropic hormone, growth hormone, luteinizing hormone, and follicle-stimulating hormone were normal in most patients. These data indicate that the removal of prolactin-secreting pituitary adenomas by a neurosurgeon accomplished in this surgical technique is effective in restoring menstrual function and eliminating lactation in most women, especially if the tumor is less than 2 cm in diameter and the preoperative serum prolactin concentration is less than 200 ng/ml.

Adenoma↗
PubMed1979

Interrelationships of circulating maternal steroid concentrations in third trimester pregnancies. II. C18 and C19 steroids: estradiol, estriol, dehydroepiandrosterone, dehydroepiandrosterone sulfate, delta 5-androstenediol, delta 4-androstenedione, testosterone, and dihydrotestosterone.

This report describes aggregate time trend effects of advancing gestational age on circulating maternal concentrations of 17beta-estradiol (E2), estriol (E3), dehydroepiandrosterone (D), dehydroepiandrosterone sulfate (D-S), delta 5-androstenediol (delta 5 diol), delta 4-androstenedione (delta 4 A), testosterone (T), and dihydrotestosterone (DHT) in a sequential series of 155 blood samples obtained from 19 normal pregnant women ranging from 26-40 weeks gestational age. Only E2, E3, and D-S show aggregate time trend effects. Log (E2) plots as a linear positive sloping curve from 26-40 weeks. Log (E3) plots as a positive sloping curve that is significantly steeper than log (E2) (P less than 0.05). Log (D-S) plots into a negative sloping curve which mirrors the pattern for log (E2) but cannot be statistically associated with log (E2) except for the opposite sign of their slopes, which are both significantly different from a zero slope (P less than 0.05). delta 4 A, T, DHT, delta 5 diol, and D show no aggregate time trends; however wide, comoving undulations for delta 4 A, T, DHT, and delta 5 diol between 26-28 and 38-40 weeks are confirmed in time by comparison of log mean plots and in magnitude by regressing the C19 steroids on one another. D shows virtually no association with the other C19 steroids. All C19 steroids, except for T, circulate at nonpregnant concentrations, implying that there is little placental secretion of these steroids into the maternal circulation.

Androgens↗