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Biomedical subjects

B Claustrat

Publications and source records attributed to B Claustrat.

At least 127 records · Page 7Linked to original sources
PubMed1982

Spontaneous pituitary tumors in the Wistar/Furth/Ico rat strain. An animal model of human prolactin adenoma.

Twenty-three spontaneous pituitary tumors in 58 rats of Wistar/Furth/Ico strain were studied. The incidence is 38% in rats older than 10 months; it rises with age, with a maximum at 28-32 months (68.7%) and is higher in females (71.4%) than in males (35%) over 17 months. Light-microscopic and immunocytochemical studies revealed 20 prolactinomas in 19 rats (19/58, 32.7%) and 3 spongiocytic nonimmunostaining adenomas (3/58, 5.2%). The prolactinoma is often hemorrhagic. The cells, often arranged in sheets and agranular, are mostly positive with anti-rat prolactin (rPRL) serum. They have few polymorph granules and a well-developed rough endoplasmic reticulum. In the spongiocytic adenoma, the cells are arranged in cords. Their cytoplasm is slightly vacuolated. In prolactinoma-bearing rats, the mean plasma PRL value was 213 +/- 72.5 microgram/1 (SEM) (N = 15 +/- 1.8 microgram/1 [SEM]). A linear correlation was found between the logarithm of the tumoral pituitary weight or of the tumor size and the logarithm of the prolactinemia. Because of the analogies between these rat prolactinomas and 57 human prolactinomas, the Wistar/Furth/Ico rat strain is considered as a good animal model.

Adenoma↗
PubMed1981

Human pituitary gonadotropic adenoma; histological, immunocytochemical, and ultrastructural and hormonal studies in eight cases.

Among 230 surgically removed pituitary adenomas, eight tumours showing immunostaining gonadotropic cells and elevated intratumours gonadotropin concentrations have been detected (frequency: 3.5 per cent.). By light microscopy the tumours were composed of agranular cells and generally PAS negative cytoplasm. The immunofluorescence technique revealed the presence of immunoreactive FSH (beta-subunit) alone in two cases, of both FSH and LH in six cases with immunoreactive beta endorphin in two of them. By electron microscopy, the cells contained an often dilated moderately or well developed rough endoplasmic reticulum, secretory granules measuring 150 nm to 200 nm which varied in electron density, and numerous microtubules. Basal plasma FSH and LH levels were simultaneously elevated in two cases; FSH levels alone were elevated in two cases; in three cases, both FSH and LH plasma values were normal. FSH and LH intratumour concentrations were simultaneously elevated in five cases; FSH alone was elevated in two cases. In all cases, the concentrations of the other hormones were negligible, except in two cases where beta endorphin concentration was elevated. The comparison of the immunocytochemical findings, the hormonal plasma levels and intratumour concentrations showed a good relationship between the immunoreactivity of the tumour and the intratumour RIA. The gonadotropic adenoma is uncommon but not rare. Its diagnosis is possible if immunocytochemical techniques are applied.

Adenoma↗
PubMed1981

[Klinefelter's syndrome associated with precocious puberty due to tumoral secretion of chorionic gonadotropins].

A 8 and a half year-old boy presented with precocious puberty related to a malignant thoracic teratoma. He was also shown to have a Klinefelter syndrome. Precocious puberty related mainly to the liver, intracranial or thoracic tumors is rare. It seems to be exclusively observed in boys. The slight testicular enlargement is the main clinical sign. The contrast between high LH and low FSH levels is the most striking biological data. The diagnosis is proved by plasma HCG, beta-HCG and alpha-foetoprotein determination. Our patient is the third one with Klinefelter syndrome; this this association is certainly not fortuitous.

Child↗
PubMed1980

Evidence for the presence of melatonin in the human brain.

Melatonin was measured by radioimmunoassay in human brain and pineal gland. Levels were 50 times lower in brain than in pineal. The distribution appeared uneven between the various areas studied. No measurable hydroxyindol-O-methyltransferase activity could be shown. These findings suggest that what appears to be melatonin in the human brain is unlikely to be synthesized in situ.

Acetylserotonin O-Methyltransferase↗
PubMed1980

Morphological and biochemical relationships in 31 human pituitary adenomas with acromegaly.

In 22 pure GH cell adenomas and 9 mixed GH cell-prolactin cell adenomas with acromegaly, we compare the morphological and functional data (secretory activity and granular appearance) with GH levels (radioimmunoassays) in the blood and in the tumor. According to morphological criteria, the secretory activity is marked in 13 cases (Group I), mild in 9 cases (Group II), and weak in 9 others (Group III). The mean values of the plasma GH levels in the 3 groups (80 ng/ml plus or minus 22; 26.5 ng/ml plus or minus 2; and 16.89 ng/ml plus or minus 2 respectively) are significantly different. In 17 densely granulated adenomas and 14 sparsely granulated adenomas, the plasma GH values were very variable. The mean levels of these 2 groups (49.76 ng/ml plus or minus 22 and 41.8 ng/ml plus or minus 7.8 respectively) are not significantly different. The GH concentrations in the tumor were also very variable (358 to 78,900 ng/mg). Their highly significant relationship with the granular appearance is an indirect proof of the granular localisation of GH. We distinguish between 4 functional aspects of the GH cell adenoma which define the different levels of synthesis, storage, and excretion. The secretory activity of the GH adenomatous cell varies with the adenomas and differs from that of the normal cell.

Acromegaly↗
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

Normal pregnancies after treatment of hyperprolactinemia with bromoergocryptine, despite suspected pituitary tumors.

Bromocryptine treatment was administered to 15 patients with amenorrhea and galactorrhea (AG) and to 1 patient with amenorrhea. All of them had increased plasma PRL levels. Of these 16 patients, 4 had a normal sella turcica (ST; group STO), 4 had a slight enlargement (group ST+), and 7 had a clear enlargement of ST (ST++) but no evidence of suprasellar extension. Ovulation was restored in 15 patients by bromocryptine treatment only. In one patient, ovulation resumed only after human pituitary gonadotropin treatment in combination with bromocryptine. There was no correlation between basal prolactinemia, PRL stimulability or suppressibility, the size of ST, or the efficiency of bromocryptine treatment. Every patient with normal LH response to either LRH or clomiphene or both resumed ovulation. Ovulation resumed in 3 patients among the 4 with abnormal LH response to either LRH or clomiphene or both. Among the 14 who desired pregnancy, 13 became pregnant. To date, 12 patients (ST++, 5; ST+, 3; STO, 4) have delivered normal babies. The courses of pregnancy were normal. During pregnancy, no change of ST was noted on lateral and frontal skull x-ray performed in every patient at trimonthly intervals. There was no change in the sellar index in 10 patients after pregnancy, as compared to the pretreatment status. In the presence of a pituitary adenoma or in patients with hyperprolactinemia and amenorrhea and galactorrhea, bromocryptine treatment may cure sterility without pituitary complication during pregnancy.

Adult↗
PubMed1978

[Plasma prolactin, progestrone and oestradiol during labour and postpartum (author's transl)].

The changes in the levels of plasma prolactin, progesterone and oestradiol were studied in 20 women during labour and immediately after delivery. The study of these levels shows that there is a mechanism for inhibiting the galactopoietic action of prolactin. Lifting this inhibition allows the milk to come in. This inhibition is probably due to circulating steroids, but this study does not allow us to differentiate clearly between the respective roles of oestradiol and progesterone, chiefly because of their short half-life.

Estradiol↗
PubMed1977

Familial idiopathic hypogonadotrophic hypogonadism.

A new case of familial idiopathic hypogonadotrophic hypogonadism is presented: 3 males and 2 females among 9 siblings are affected. Very low to non-detectable levels of plasma LH and FSH levels were found in each patient. LH-RH stimulation test gave in one male a slight increase in plasma LH levels while no change was observed in the others. Prolonged treatment with gonadotrophins or testosterone gave poor results in the males while evidence of ovulation was obtained in the two females during a unique induced artificial cycle with combined HMG and HCG treatment; rapid feminization was also obtained in the females with oestrogen therapy. The striking difference in the results of the substitution treatments between males and females suggest that some degree of acquired insensitivity of the testes to gonadotrophins and of peripheral tissues to male sex hormones are present in male hypogonadotrophic hypogonadism. This may be the consequence of a lack of hormonal stimulation or impregnation during infancy and childhood

Adult↗
PubMed1977

[Human fetal antehypophysis in vitro. II. Immunocytological study and radioimmunoassay of LH and FSH (author's transl)].

Human fetal antehypophysis (16 males, 16 females and 4 unknown sex) were cultivated during several weeks. By immunocytochemistry LH gonadotroph cells were determined with anti-hTSH and anti-pLH serum. The release in vitro of LH and FSH was studied by radioimmunoassay. At the first medium change, the quantity of LH and FSH release was related to the gestational age and sex. A rapid decline of both LH and FSH occured over the 10 first days. There after, a basal release of LH was maintained during several months; the release of FSH was generally maintained at the lower limit of the assay. After 1 month in vitro, the level of LH could not be related to the sex. Release of LH was stimulated by synthetic LRF. A significant increase was observed independently of the sex and age of the fetuses studied.

Culture Techniques↗