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Biomedical subjects

C Blacker

Publications and source records attributed to C Blacker.

34 records · Page 2Linked to original sources
PubMed1986

Steroid profiles during cycles with HCG stimulation of luteal function during in-vitro fertilization cycles.

178 in-vitro fertilization cycles have been explored for luteal function. Clomiphene and human menopausal gonadotrophins were used for ovarian stimulation and some patients were supplemented with human chorionic gonadotrophin (HCG) (5000 IU) on the day of laparoscopy, and also 2 and 4 days later. An imbalance of luteal function was observed in non-supplemented stimulated cycles, with hyperoestrogenicity and a relatively low production of progesterone. The administration of HCG reduced this imbalance by improving the production of progesterone without affecting the production of oestradiol-17 beta.

Adult↗
PubMed1984

Estrogen 2-, 4-, 6- or 16-hydroxylation by human follicles shown by gas chromatography-mass spectrometry associated with stable isotope dilution.

Follicular fluid, obtained by aspiration of human Graafian follicles in cycles stimulated by clomiphene and hMG + hCG, was analyzed for estrogen content. Carefully controlled extraction and efficient preliminary chromatographic separations were set up. Deuterium labelled analogues were used as internal standards for the quantitative determination by gas chromatography-mass spectrometry and some new derivatives were included in the identification procedure. The identified estrogens and their mean concentrations (ng/ml) are: 2-hydroxy-estrone (0.14), 4-hydroxy-estrone (0.12), 2-hydroxy-estradiol (0.36), 4-hydroxy-estradiol (0.34), 6 alpha-hydroxy-estradiol (13.2), 6 beta-hydroxy-estradiol (6.40), 2-methoxy-estrone (0.83), 2-methoxy-estradiol (10.5), 16-oxo-estradiol (0.41), estriol (10.2), estradiol-17 beta (1365), estradiol-17 alpha (1.91), estrone (211). Metabolism of estradiol by 6-hydroxylation seems to be predominant in the human ovary. The other data suggest that 2-hydroxylation, with subsequent O-methylation, and 16-hydroxylation may be by equivalent pathways, since the sum of the 2-methoxy-estrone and 2-methoxy estradiol concentrations is rather similar to the estriol concentration. Hence, the latter three compounds and the 6-hydroxy-estradiols may be end-products of follicular estrogen metabolism. Catechol estrogen formation by 2-hydroxylation and 4-hydroxylation is shown to be of equal importance in the ovary. These results confirm the presence in the human follicle of various competing estrogen hydroxylases and catechol-O-methyltransferase.

Estrogens↗
PubMed1984

[Evaluation of plasma tumor markers in germinal tumors of the testis].

Pregnancy specific beta 1 glycoprotein (PS beta 1G), human choriogonadotropin (hCG), alpha-foetoprotein (AFP) and carcinoembryonic antigen (CEA) were measured simultaneously in 58 patients with a progressive germinal testicular tumour, and in 20 patients in complete remission. All markers were negative in all the cases in remission, and in 1 case of progressive teratoma. The specificity of the association of these 4 markers was 76 p. 100, higher than any of them measured alone. There was no correlation between individual markers with respect to histological classification. The highest diagnostic specificity was obtained with hCG in all types of tumours. PS beta 1G was associated with hCG but with a lower specificity. AFP is mainly related to embryonic carcinoma but may be raised in all forms of tumour, except seminomas. CEA was positive less often, irrespective of the type of tumour, and never alone. The value of measuring these tumour markers is double: on the one hand it allows better characterisation of the tumour, and on the other, the clinical course and efficacy of treatment can be followed-up more closely and tumour recurrence may be diagnosed at an early stage.

Carcinoembryonic Antigen↗
PubMed1984

[Tumors secreting choriogonadotropin in children].

Fourteen cases of sexual precocity due to choriogonadotropin (hCG) secreting tumors are reported. One pineal and 4 gonadal tumors were observed in 5 girls, whilst 2 supra-sellar, 4 mediastinal, 1 gonadal and 2 hepatic tumors were observed in 9 boys. In all children, immunoreactive plasma LH was high (4 to 30 mIU/ml) but non-responsive to LH-RH, due to the presence of hCG (15 to 6,000 mIU/ml). In the 4 boys with mediastinal tumors the karyotype was 47,XXY. In girls, hCG secreting tumors are a uncommon cause of sexual precocity (less than 1 p. 100). In boys their incidence seems to be the same as the incidence of idiopathic precocious puberty, that is 21 p. 100 of sexual precocities due to androgenic secretion of testicular origin.

Adolescent↗
PubMed1979

Serum and seminal gonadotropins in normal and infertile men: correlations with sperm count, prolactinemia, and seminal prolactin.

Serum and seminal gonadotropins were evaluated in 30 normozoospermic and 30 oligozoospermic patients. Mean values of basal serum gonadotropins were higher in the oligozoospermic group than in the normozoospermic group: 3.8 versus 1.8 ng/ml and 3.3 versus 2.2 ng/ml for FSH and LH, respectively. Seminal FSH levels were comparable in the normozoospermic and oligozoospermic groups (0.8 versus 0.8 ng/ml, respectively) and were constantly lower than serum FSH levels in both groups. Seminal LH values were constantly higher than serum LH values in the normozoospermic group, whereas in the oligozoospermic group seminal LH values were higher, similar, or lower than serum LH values. However, no significant difference was noted between the two groups for seminal LH values: 3.6 (normozoospermic group) versus 4.1 ng/ml (oligozoospermic group).

Adult↗
PubMed1979

[Orthostatic hypotension in complicated diabetes mellitus: study of the renin-angiotensin-aldosterone system (author's transl)].

Plasma renin activity (P.R.A.) and plasma aldosterone (P.A.) were studied basally and after various stimuli in eight diabetic subjects with orthostatic hypotension and autonomic neuropathy. Five of them had chronic renal failure and proteinuria. On a diet containing 100 mEq Na/24 H, mean P.R.A. was 0,80 +/- 0,32 ng/ml/h in the supine position and 0,95 +/- 0,43 ng/ml/h in the upright position (N.S.); mean P.A. was 111 +/- 77 pg/ml in the supine position and 234 pg/ml in the upright position (p less than 0,01). On a diet containing 10 mEq Na/24 H, mean P.R.A. was 1,54 +/- 0,76 ng/ml/h in the supine position and 2,44 +/- 1,53 ng/ml/h in the upright position (N.S.). There was little stimulation of P. R. A. by low sodium intakes. After furosemide (n = 6), epinephrine + norepinephrine (n = 4) or diazoxide (n = 2), there was no stimulation of P.R.A. and P.A. Thus in diabetic patients with orthostatic hypotension and autonomic neuropathy basal values of P.R.A. and P.A. are in the normal range but there is dysregulation of renin-angiotensin-aldosterone system.

Adult↗
PubMed1978

Changes in pituitary gonadotropins during the amenorrhoea-galactorrhoea syndrome due to sulpiride.

Sulpiride, a dopamine receptor blocker which raises prolactin, was given to six women with idiopathic amenorrhoea for 10 days and to eleven women with regular cycles for 3 to 6 months. The latter group developed galactorrhoea and amenorrhoea during treatment. Basal LH AND FSH concentrations showed no significant changes. At 3 months but not at 10 days (amenorrhoea group) or 6 months (regular menses group) the area-under-the-curve of LH response to LHRH was increased. FSH responses to LHRH was not altered. The significance of these results to the hyperprolactinaemia-amenorrhoea syndromes are discussed.

Amenorrhea↗
PubMedDate not supplied

Evaluation of PS beta 1G and other tumor markers in germ cell tumors of the testis.

Pregnancy Specific beta 1 Glycoprotein (PS beta 1G), human choriogonadotropin (hCG), alpha foeto protein (AFP) and Carcino Embryonic Antigen (CEA) were assayed in 58 patients with active germ cell tumors and 20 patients in complete clinical and radiological remission. The markers were negative in all the cases in remission as well as in one case of pure teratoma. The positivity rate of the four markers together is 75%, which is better than for any marker alone. All the markers except AFP seem ubiquitous with respect to the histological classification. The highest positivity rate is obtained for hCG in all the histological types. PS beta 1G is related to hCG but its positivity rate is quite lower. AFP is mainly related to embryonal carcinoma but can be associated with any type of tumor except seminoma. CEA is less frequently positive, always associated with other markers and seems therefore useless for the diagnosis of germ cell tumors.

Carcinoembryonic Antigen↗
PubMedDate not supplied

[Therapeutical effects of bromocriptine (CB 154) in 10 acromegalic subjects. Study of somatotrophic function and clinical survey (author's transl)].

Plasma GH levels were studied following acute administration of 2.5 mg of bromocriptine (CB 154) in 12 acromegalic patients. In 9 responders, reduction of GH levels was obvious 2 to 4 hours after bromocriptine administration and the lowest values were achieved between 5 and 8 hours following drug absorption. This pattern suggested the use of bromocriptine at a dose of 2.5 mg six-hourly in chronic treatment of acromegaly. Chronic administration of CB-154 in 10 acromegalic patients was followed by a stable reduction of plasma GH levels in seven subjects. No appreciable variation in GH levels were observed in one patient who was unresponsive to acute administration of CB-154 and in two other subjects treated with 2.5 mg 12-hourly. In three patients who had high plasma GH levels inspite of an anterior treatment by hypophyseal surgery and/or physiotherapy, plasma GH values were normalised under bromocriptine therapy. (9 to 24 months). In the four other subjects, high basal plasma GH levels were reduced with at least 50% reduction rate from baseline. Nevertheless, in two subjects from the latter group bromocriptine daily dose was increased to 20 mg divided in four fractions, because of an escape phenomenon to initial dose regimen. Normalisation or reduction of plasma GH levels was associated with considerable clinical improvement. Tolerance of the drug was excellent in all patients but four who experienced nausea and vomiting; these side effects disappeared when treatment was reduced and then increased gradually.

Acromegaly↗