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Biomedical subjects

M G Forest

Publications and source records attributed to M G Forest.

At least 109 records · Page 6Linked to original sources
PubMed1980

Immunological interference of the synthetic aromatase inhibitor 1,4,6-androstatriene-3,17-dione (ATD) and its metabolite(s) in the radioimmunoassay for testosterone.

Radioimmunoassay (RIA) for testosterone (T) in unchromatographed plasma extracts from ATD-treated rats gave spuriously high values for T. Cross-reaction and chromatographic studies subsequently showed that ATD and, to a much greater extent, its metabolite(s) were responsible for this overestimation. Celite column chromatography proved to be an effective way of separating T from ATD and its product(s) of metabolism.

Androstatrienes↗
PubMed1980

Perinatal activity of the hypothalamic-pituitary-gonadal axis in the lamb. II. In vitro testicular response to human chorionic gonadotropin and choleratoxin in the first 2 months of life.

Testicular response to human chorionic gonadotropin (hCG) was studied in male lambs. Adenosine 3':5'-cyclic monophosphate (cAMP), testosterone (T), delta 4-androstenedione and 17 alpha-hydroxyprogesterone content and cAMP and T production by dispersed interstitial cells were assessed in control and hCG-pretreated animals. Plasma T levels increased after hCG at 1, 4 and 8 weeks. Increments in the testicular content of cAMP, delta 4-androstenedione, and T were greater at 8 weeks and that of 17 alpha-hydroxyprogesterone and 125I-hCG binding to dispersed interstitial cells were identical at all ages. cAMP and T production by dispersed interstitial cells from nonstimulated animals and the response to hCG and choleratoxin were similar in all lambs. In contrast, cAMP and T production were higher at 1 week only in animals pretreated with hCG in vivo. These data are compatible with hCG-induced desensitization at 4 and 8 weeks.

Androstenedione↗
PubMed1980

Kinetics of the HCG-induced steroidogenic response of the human testis. III. Studies in children of the plasma levels of testosterone and HCG: rationale for testicular stimulation test.

Little information is available regarding the time, rhythm, number, and appropriate dosage of human chorionic gonadotropin (HCG) for adequate testing of testicular function in human. The time course of the effect of two, three, or seven HCG injections at intervals of one, five, and two days, respectively, on the plasma levels of testosterone was studied in 11 boys. The first injection induced a progressive and modest rise of T. The second given one day later had little additive effect, maximal values being seen 72 to 120 hr later. In the prepubertal boys to whom several HCG injections were given, testosterone levels reached comparable levels after four injections every five days or seven injections every other day. Although the number of subjects studied was relatively small, these results give some rational basis for the following HCG test: two or four injections at four-day intervals.

Child↗
PubMed1980

Familial male pseudohermaphroditism due to 17-20-desmolase deficiency. I. In vivo endocrine studies.

In two siblings with male pseudohermaphroditism (ambiguous external genitalia, XY karyotype) and apparently normal glucocorticoid function, plasma concentrations of 10 progestagens or androgens measured by specific RIAs were found to be abnormal under either basal or dynamic conditions. Basal levels of delta 4-androstenedione, dehydroepiandrosterone, and dehydroepiandrosterone sulfate were subnormal and failed to rise after ACTH stimulation both before and after castration. Meanwhile, levels of pregnenolone, pregnenolone sulfate, 17 alpha-hydroxyprogesterone, and 17 alpha-hydroxypregnenolone were extremely high under basal conditions and rose further after ACTH. All of the progestagens and cortisol were suppressed by dexamethasone. After hCG stimulation, either before treatment or during dexamethasone therapy, the rise in testosterone was less than 100 ng/dl, while the progestagens showed an abnormally high rise. The latter were markedly reduced after castration. These findings are consistent with steroid 17--20-desmolase deficiency in both the testes and adrenal glands. In the third brother, who had only slight abnormalities of his genitalia, a mild form of the same defect was suspected. Low androgens, high 17 alpha-hydroxypregnenolone, and 17 alpha-hydroxyprogesterone levels were found in the amniotic fluid and umbilical cord and peripheral blood at birth. The parents, who were not consanguine, had normal baseline levels of all hormones. The familial occurrence of the disease is suggestive of autosomal recessive inheritance.

17-alpha-Hydroxypregnenolone↗
PubMed1980

Concentration of 14 steroid hormones in human amniotic fluid of midpregnancy.

Amniotic fluid (AF) levels of all steroids leading from pregnenolone (delta 5Preg) to androgens and estrogens of both the delta 5 and the delta 4 pathways and those of cortisol and cortisone have been determined in 63 normal pregnancies (12-19 weeks gestation). The 12 unconjugated steroids [delta 5Preg, 17 alpha-hydroxypregnenolone, progesterone, 17 alpha-hydroxyprogesterone, dehydroepiandrosterone (DHA), delta 4-androstenedione, delta 5-androstene-3 beta,17 beta-diol (delta 5Adiol), testosterone (T), estrone, 17 beta-estradiol (E2), cortisol, and cortisone] were measured by specific RIAs after appropriate purification by Celite or LH-20 column chromatography, while the sulfates of DHA and delta 5Preg were assayed directly on diluted samples. There were distinct sex differences; T and delta 4-androstenedione levels were higher (P < 0.001) in males than in females, while AF levels of delta 5Preg, 17 alpha-hydroxypregnenolone, 17-hydroxyprogesterone, DHA, and delta 5Adiol were higher (P < 0.05) in females than in males. AF levels of E2 were significantly higher in females only between 15 and 19 weeks gestation. There was no difference between sexes in AF levels of progesterone, estrone, cortisone, and cortisol. AF levels of T, delta 4-androstenedione, and E2 decreased with age in males, and AF levels of DHA increased in females during the period examined. These observed sex differences suggest that T and delta 4-androstenedione may reflect fetal testicular activity, while E2 and 17-hydroxyprogesterone might reflect fetal ovarian activity. Determination of AF levels of T would appear to be a valuable screening test for antenatal diagnosis of sex (predictive error, less than or equal to 15%), but not in the presence of steroidogenic enzyme defects. Elevated levels of 17-hydroxyprogesterone were found in the AF of two fetuses with either a 17-20 desmolase defect or 21-hydroxylase deficiency; AF levels of androgens were low in the former and high in the latter.

Amniotic Fluid↗
PubMed1980

[Plasma dehydroepiandrosterone sulfate (DHAS) in paediatric endocrinology (author's transl)].

The normal values of plasma DHAS were determined by measuring the levels in 637 normal subjects whose ages ranged from birth to adulthood. The changes induced by adrenal stimulation and suppression, and by testicular stimulation tests were studied. Knowledge of the normal values and the changes with age is essential for the interpretation of the results in children with endocrine disorders. Normal DHAS levels were found in cases of precocious puberty. High levels were found in pseudo-precocious puberty and in premature pubarche. Low levels were detected in primary or secondary adrenal insufficiency and in delayed adrenal puberty.

Adolescent↗
PubMed1979

[Tissue specificity of testosterone fixation: demonstrated by ultrastructural immunocytochemistry after cryoultramicrotomy].

Testosterone can be detected by immunocytochemistry on ultrathin slices obtained by cryoultramicrotomy. Testosterone detected by this method is likely bound on a binding site having a high affinity. In order to study the tissue specificity of this binding, testosterone was tested in Rat pituitary gland, liver and adrenal glands. Immunoreactive testosterone was detected in the gonadotropic cells of the pituitary gland, in the hepatocytes. Testosterone was not detected by immunocytochemistry in the pituitary cells other than the gonadotropic cells and in the cells of the medulla of adrenal glands. These data testify in favour of tissue specificity of the testosterone binding.

Adrenal Glands↗
PubMed1979

3 beta-hydroxysteroid dehydrogenase deficiency. Follow-up study in a girl with pubertal bone age.

Follow-up data on a girl with 3 beta-hydroxysteroid dehydrogenase deficiency at a pubertal bone age are presented. On examination at age 14.7 years (bone age 12 years), there was no spontaneous breast development. On treatment with hydrocortisone and fludrocortisone, most steroids with the exception of increased 17OH-pregnenolone in plasma and delta 5-pregnenetriol and pregnanetriol in urine, were normal. After 1 week off hydrocortisone, plasma 17OH-pregnenolone, DHA and delta5-androstenediol and urinary delta 5-pregnenetriol and pregnanetriol increased markedly, while plasma 17OH-progesterone increased only slightly. On increased hydrocortisone medication, there was no response of plasma estradiol to HMG. This first observation of a pubertal girl with 3 beta-hydroxysteroid dehydrogenase deficiency indicates that in this patient, the defect persists at a pubertal bone age and that it is not limited to the adrenals, but also affects the ovaries. Girls with this type of defect thus require estrogen replacement at a bone age of about 12 years. The large quantities of pregnanetriol in the urine are not due to an incomplete defect or an additional 21-hydroxylase deficiency, but most likely to the peripheral or hepatic conversion of 17OH-pregnenolone or delta 5-pregnenetriol.

3-Hydroxysteroid Dehydrogenases↗
PubMed1979

Pattern of the response of testosterone and its precursors to human chorionic gonadotropin stimulation in relation to age in infants and children.

The pattern of response to 14-day hCG stimulation was studied in 100 apparently normal infants and children and in 2 boys with total adrenal insufficiency. Response was estimated on the levels (nanograms per dl) of testosterone (T), delta4-androstenedione (delta4), and 17-hydroxyprogesterone (17OHP) before and after hCG. Basal levels of T, delta4, and 17OHP increased significantly after 9--10 yr of age and before the onset of puberty. It would thus appear that the changes of adrenarche are also expressed by the secretion of delta4 androgens. After hCG, levels of T (629 +/- 218) did not vary with age in infants or prepubertal children but increased significantly at the onset of puberty (1265 +/- 253). Post-hCG levels of delta4 and 17OHP increased with age, but their increments (respectively, 31.1 +/- 14.6 and 108.6 +/- 42.2) did not vary between 2--12 yr of age. On the other hand, the rise of delta4 after hCG tended to be higher in infancy and early pubescence. These data suggest that 1) testicular unresponsiveness to gonadotropins does not seem to be responsible for the postnatal decline of testicular activity; 2) during the prepubertal period there are no age-related changes in the absolute rises of T, delta4, or 17OHP levels after hCG stimulation; and 3) increasing sensitivity of the testis to gonadotropic stimulation appears to be one of the very first changes occurring at the onset of puberty.

Adolescent↗
PubMed1979

[Familial case of male pseudohermaphroditism due to 17-ketoreductase defect: late diagnosis in the "aunt" of a patient with the same defect (author's transl)].

A 42 year old (46 XY) subject with 17-ketosteroid reductase deficiency was investigated. The patient reared as female, has developed masculine features (facial hair, male distribution of body hair, male body habitus, acne and clitoridomegaly) at about 15 years of age but never consulted. She married at 22 years and for 20 years thought to have a "normal" female sex life. Only when her 14 year old "niece" was investigated (1) and treated for similar problems she realized hers. She had a small phallus with perineal urethra, vaginal pouch absence of labia minora and undescended testis, no breast development. Baseline peripheral studies showed plasma testosterone (T) in the range of Tanner II stade of puberty (150 ng/dl), elevated delta 4-androstenedione (delta 4) (930 ng/dl) and estrone (E1) (33,5 NG/DL) LEVELS 6--8 times above normal, but subnormal estradiol levels. Increased basal gonadotropins showed an hyper-response to LHRH stimulation. Dynamic tests (ACTH test, Dexamethasone suppression, and hCG stimulation) showed that abnormal delta 4 and E1 were not of adrenal origin. In the spermatic veins delta 4 levels were extremely high (239 micrograms/dl) but T levels low (11.4 micrograms/dl). delta 4/T ratio in the spermatic vein was much higher than in the peripheral blood suggesting intact peripheral conversion of delta 4 to T. After castration all hormone levels returned to the range usually seen in agonadic male or female adults.

17-Hydroxysteroid Dehydrogenases↗
PubMed1979

[Study of a new case of male pseudohermaphroditism due to 17-ketosteroid reductase deficiency (author's transl)].

We studied a 17 year old patient with primary amenorrhea, hirsutixm, clitoral enlargment, poor breast development and 46, XY karyotype. The results shown in table clearly indicate a 17-ketosteroid reductase deficiency. In the view of previously described patients we can conclude that: 1) intensity of virilisation depends on both plasma testosterone and androstenedione levels; 2) importance of gynecomastia depends on plasma E2 but not E1 levels; 3) FSH levels are not correlated with circulating androgens or estrogens but presumably depends on importance of seminiferous tubules' lesions.

17-Hydroxysteroid Dehydrogenases↗
PubMed1978

Approach to the mechanism of androgen overproduction in a case of Krukenbery tumor responsible for virilization during pregnancy.

Virilization may occur during pregnancy as the result of an ovarian Krukenberg tumor. mechanism of the androgen overproduction in this exceptional condition is still poorly understood. A new case is reported in which only in the postpartum clinical, endocrine, and endoscopic studies led to the diagnosis of an ovarian Krukenberg tumor secondary to a gastric carcinoma. In the mother, basal hormonal studies were done 1 and 4 weeks after delivery, then after gastric and ovarian surgery. Three months after delivery, ovarian steroid response to hCG (priming dose, 5000 IU; then 1500 IU every other day for 12 days) and a study of progesterone (P) metabolism at a steady state after a constant infusion of [3H]P and cold P (92 micrograms/min leads to blood production rate (BPR) of 152 mg/day designed to reproduce the BPR of P usually seen in pregnancy) were successively performed. Hormones were measured by specific RIAs after chromatographical purification. Basal hormonal levels were normal in the child. In the mother, on the 5th day postpartum, mean hormone levels (in nanograms per dl) were: testosterone (T), 4181; androstenedione (delta 4), 8876; 17 alpha-hydroxyprogesterone (17-OHP), 9746; P 1075; estrone (E1), 195; and estradiol (E2), 151. One month later, levels were normal for the follicular phase; T, 40; delta 4, 146; P, 52; E2, 9; and E2, 4.5. At both times, dehydroepiandrosterone was normal (703-750). Hormone levels increased progressively during hCG stimulation but their time course was different between hormones. At the end of the test, T. 144; delta 4, 746;' 17-OHP, 789; P, 723; E1, 37; and E2, 20. The MCR of P was decreased, 1450 liters/day (normal, 2020). Conversion ratios between products and precursor during constant infusion were normal. From these data, obtained in four different conditions (postpartum period, hCG stimulation, progesterone infusion, and after oophorectomy), the following can be concluded: adrenal production of dehydroepiandrosterone was normal; the ovarian overproduction of androgens likely resulted from the excessive reductive metabolism of both placental and ovarian P along the delta 4 steroid biosynthetic pathway by an hypertrophic stromal compartment; and HCG stimulation seems to be the necessary stimulus for this condition. The enhancement by T on its own peripheral production is also discussed.

Androgens↗