[Malignant schwannoma of the neck]. / Schwannoma maligno de cuello.

Malignant schwannoma (MS) is a tumor of the peripheral nervous system, extremely rare when settled in head and neck. Conversely these two are preferable locations for benign schwannomata. We report a feminine patient, 74-year-old, with a right laterocervical massa, evolving in 3 months, surgically removed and postoperative radiotherapeutic treatment, which remains asymptomatic since one year and a half.

[Measurement of biological activity of hLH. Multicenter study]. / Measure de l'activité biologique de la hLH. Etude multicentrique.

This report describes the results of a multicentric study of biological methods for luteinizing hormone (hLH). The production of testosterone by animal Leydig cells is used by five laboratories with different methodologies including rat, mouse and pig cells. Dose-response curves of testosterone production, quality criteria and results on a physiological population of men and women, are reported and discussed. It is concluded that the bioactive determination of hLH must be considered as a reference method used in discordances between clinic and immunological methods.

Early modifications of biochemical markers of bone metabolism in spinal cord injury patients. A preliminary study.

Spinal cord injury is associated with the development of a rapid and severe osteoporosis which might reflect uncoupling between bone formation and resorption. A prospective study was made in 6 spinal cord injury patients followed up to 2-3 months after onset with various markers of a) bone formation: osteocalcin and C-terminal peptide of type I procollagen, b) bone resorption: pyridinolines and C-terminal telopeptide of type I collagen, c) connective tissue metabolism: amino-terminal propeptide of type III collagen (PIIINP). Preliminary results show that early after onset, bone formation was depressed as compared to dramatically increased bone resorption. Low bone formation rate lasted two weeks before it began to raise, while bone resorption showed a continuous tendency to increase. The dramatic increase in PIIINP levels might represent some attempt of bone to repair. This paper describes the evolution of various biochemical markers of bone and connective tissue metabolism after onset of paralysis and critically reviews the use of those markers in patients with spinal cord injury.

[Immunoassay and measurement of the biological activity of serum hLH: results obtained of a multicenter study]. / Immunodosages et mesure de l'activité biologique de l'hLH sérique: résultats obtenus lors d'une étude multicentrique.

The discrepancy between results obtained using different anti-hLH antibodies available on the market led us (in the context of a contract with the CNAMTS) to compare the results of hLH immunoassays (eight different reagents) with those of hLH bioassays based on the measurement of the steroidal activity of this hormone on mouse, rat or pig testicular preparations (five methodologies). Twenty-nine samples of serum or human serum pools were tested. The values resulting from these tests reveal differences linked to the nature of the antibodies or to the methodological conditions used for the testicular preparations. Some antibodies seem unable to identify some hLH forms which, however, can be detected by biological methods.

[Thyroglossal duct cysts]. / Quistes del conducto tirogloso.

Perusal of records concerning 14 patients diagnosed and operated for Cysts of the thyrolingual duct, in the last 5 years (1984-1989). In this term the AA. have had at their disposal the newly diagnostic methods introduced at their Hospital. Among the clinic features considered in the paper, for instance, the age, they point out the differences verified between the own series and that of other authors. In the first decade only 28.57%; 35.71% in the second decade; and beyond 30 years again 35.71% of cases. Sixty-seven was de elder one. As well is emphasized the sexes distribution: 72% account for men and 28% for women, in the AA's statistics. None of the operated showed malignancies and postoperative recurrences were null.

Sex differences in serum luteinizing hormone and testosterone in the human neonate during the first few hours after birth.

Blood was obtained from human male and female neonates within a few minutes after birth, and at intervals thereafter for up to 21 h. Serum LH was substantially higher at birth for boys than girls. For most boys, serum LH fell precipitously during the next hour; serum LH remained low for the remainder of the period sampled in both boys and girls. In girls, serum testosterone was low at birth and remained low for at least 21 h. At birth, serum testosterone in boys was higher than for girls, increased dramatically during the first 3 h after birth, and remained elevated (2 to 3 times higher than for girls) between 3 and 12 h after birth. In newborn human males, a sudden discharge of hypophyseal LH appears to stimulate neonatal secretion of testosterone by the testes. The functional significance of this phenomenon remains to be determined.

[The time factor in hypoacusis caused by acoustic trauma]. / El factor tiempo en la hipoacusia por traumatismo sonoro.

This article relates the results of a research made about 26 persons who are working in a noisy environment and whose sense of hearing was damaged although the noise did not exceed the authorized limits (90 dB.) the group of persons was examined every year during 5 years and the average hearing loss was computed every year as well. Average and total losses are computed and it appears that the loss during the last year is much higher than during the previous years.

[Assay of plasma progesterone and testosterone. Comparison of enzyme immunoassays and radio-immunoassays]. / Dosage de la progestérone et de la testostérone plasmatiques. Comparaison entre enzymo-immunoessais et radio-immunoessais.

Plasma progesterone (P) and testosterone (T) were determined by enzyme immunology with commercially available kits. Two kits (Serono and BioMérieux) were studied for P determination and one kit (Serono) for that of the T. The results obtained by either enzyme immunoassay were compared reliable and specific radioimmunoassays. The BioMérieux kit was shown to be more appropriate than the Serono kit for plasma P assay except in patients after oral administration of micronized progesterone because of the interference of the high levels of P metabolites. Concerning T, the Serono kit appears to yield generally adequate results in male adults but neither in men treated with dihydrotestosterone nor in females.

Experimental control of the differentiation of Leydig cells in the rat fetal testis.

In the developing fetal testis, in vitro as well as in vivo, two kinds of endocrine cells differentiate successively: Sertoli cells, which produce the Müllerian inhibitor (or anti-Müllerian hormone) and aggregate with germ cells into seminiferous cords; and Leydig cells, which release androgens. Serum added to the synthetic culture medium prevents the morphogenesis of the seminiferous cords but not the cytodifferentiation of the endocrine cells. L-Azetidine 2-carboxylic acid (LACA), a proline competitor, introduced into the medium also prevents differentiation of seminiferous cords. In the present experiments, the effects of LACA on the endocrine cells were studied. It did not suppress production of the Müllerian inhibitor, but it opposed differentiation of Leydig cells. Histochemically detectable 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) was virtually absent and the release of testosterone, delta 4-androstenedione, 17-hydroxyprogesterone, or progesterone into the medium became undetectable. Moreover, dibutyryl cAMP added to the medium during the final day in vitro had very little effect on the parameters of steroidogenesis. An excess of proline added to the LACA-containing medium permitted normal morphogenesis of seminiferous cords, normal steroidogenesis, and normal response to cAMP. LACA did not prevent the appearance of 3 beta-HSD activity in the adrenals, nor did it reduce the expression of laminin and fibronectin (data not shown) in the mesonephric structures as much as in the testes. The differentiation of the testis and especially of the Leydig cells appears to have special requirements for proline.

Testosterone levels in plasma and testes of neonatal mice.

Newborn female and male C57BL6 mice were decapitated at birth or at different times during the first 24 h after birth and testosterone was determined by radioimmunoassay in plasma and testes. In newborn females, plasma testosterone is low and does not significantly change over the first 24 h after birth. In contrast, in newborn males, plasma testosterone more than doubles during the first 2 h after birth and then falls rapidly to remain relatively low for the remainder of the 24 h period after birth. The increase in plasma testosterone is of almost certain testicular origin since it follows a decrease in testicular testosterone content. It seems likely that the increase in plasma testosterone in male mice which reaches its peak at 2 h after birth is involved in an essential way in the development of well-documented sex differences in gonadotropin secretion and behavior.

Relationship between sex hormones and haemostatic factors in healthy middle-aged men.

Associations of plasma testosterone and estradiol with some haemostatic factors (factor VII activity, fibrinogen, antithrombin III and alpha 2-antiplasmin) were cross-sectionally examined in 251 healthy, middle-aged men participating in the Paris Prospective Study II on risk factors for ischaemic heart disease. Testosterone levels were negatively correlated to factor VII activity and alpha 2-antiplasmin, the main inhibitor of fibrinolysis. No association was found either between testosterone levels and both fibrinogen and antithrombin III, or between estradiol levels and the set of haemostatic variables. The associations between testosterone and both factor VIIc and alpha 2-antiplasmin were independent of HDL-cholesterol, LDL-cholesterol, triglycerides, smoking, alcohol, body mass index and blood pressure. These results suggest that low circulating testosterone levels might be associated with a hypercoagulability state and therefore could contribute to an increased risk of IHD.

Plasma concentration of luteinizing hormone, testosterone, dehydroepiandrosterone, androstenedione between birth and one year in the male dog: longitudinal study and hCG stimulation.

A longitudinal study from peripheral blood, with samples collected every week, was performed between birth and one year of age on young Fox terriers dogs in order to determine the patterns of plasma LH, T, DHA and A concentrations. T, DHA, A curves show the same profile. The dog model shows the 3 successive steps preceding the adult life that are met in one year time: First, an infantile period between birth and the 12th week of age: the basal level of LH (4.29 ng/ml) and the 3 androgens levels (T less than 0.3 ng/ml, DHA less than 0.45 ng/ml, A less than 0.36 ng/ml) are low. A pubertal period, between the 13th week and the 36th week of age: we observe the maximum activity of the pituitary gland. The basal level of LH (7.97 ng/ml) significantly increase (P less than 0.001). The mean levels of androgens from 17 to 27 weeks of age are still quite low although significantly higher (P less than 0.03) for T and DHA than previously. After the 27th week of age, the androgens concentrations drastically increase. A post pubertal period begins at the 36th week of age. The mean LH (5.85 nh/ml) decrease. The androgens concentrations seem to plateau during the 12th month of age in the range of 2.5-5 ng/ml for T, 1.5-2.5 ng/ml for DHA and 1-2 ng/ml for A. hCG test (35 UI/kg, IM), with samples collected at 6, 12, 24, 30, 36 and 48 hours post injection, were performed at 1, 4, 7, 9 and 12 months of age. At 1 month, only minor variations were noticed; but after 4 months of age, for the 3 steroids, the same time course response was observed as in the adult dog: maximum levels were reached earlier for DHA (6-12 h) than for T and A (24 h).

[Pulsatile administration of GnRH: from the future to the present]. / L'administration par pompe du GnRH: du futur au présent.

Since the first clinical reports of the successful induction of ovulations and pregnancies using pulsatile administration of the neuropeptide GnRH by G. Leyendecker and L. Wildt's group in 1979, the role of the hypothalamic generator, as demonstrated in primates by E. Knobil, is widely accepted in human reproduction. During this time, an increasing number of group has experienced these therapies and there continues to be some controversies about the route of administration, the indications, the need for adjuvant therapies. A correct evaluation of these therapies needs multicentric studies and more accurate criteria: the MINITEL network provides a fast, inexpensive way to collect data from different groups and to perform studies with larger sample sizes. The Life table analysis method represents the more suitable method for evaluating and for comparing various therapy regimens. LH plasma pulsatility studies have been performed in humans in order to classify various "supra-pituitary" reproductive disorders. These studies are exposed to several methodological drawbacks and must be cautiously interpreted. Modelling is one of the new methodological issues which can give access to more physiological parameters.

Stimulation of estradiol-17 beta secretion by 7,12-dimethylbenz (a) anthracene during mammary tumor induction in Sprague-Dawley rats.

Testosterone, androstenedione, progesterone, 17-hydroxyprogesterone, estrone and estradiol-17 beta serum levels were measured at given times after dimethylbenz (a) anthracene (DMBA) treatment of a sensitive rat strain Sprague-Dawley (S-D) and a resistant strain Wistar (W). Tumors appeared with a 100% incidence around the 14th to 15th estrous cycle after DMBA treatment in in Sprague-Dawley rats. Hormonal determinations were made, during the 5th or 6th estrous cycle after DMBA treatment, in groups of 4-day cycling rats of both strains which were given DMBA or the carrier solution (sesame oil) when they were about 55-days old. In Sprague-Dawley female rats, DMBA treatment significantly stimulated estradiol-17 beta and estrone preovulatory surge on proestrous days. No such stimulation was found for any other steroid at any time of the estrous cycle. On the other hand, the resistant Wistar rats did not show any disturbed preovulatory or basal steroid hormone release after the carcinogen treatment. These results complete and explain previous findings concerning the hypothalamo-pituitary activity after DMBA treatment of S-D rats: an early and persistent alteration in the centers involved in the hormonal cyclicity of the hypothalamo-pituitary-ovarian axis must be a result of the DMBA treatment. This deregulation could probably account for the distant and selective production of tumors in the mammary gland induced by a single gastric administration of DMBA.

Endometrium and plasma hormone profile in the peri-menopause and post-menopause.

Endometrial histology and plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17 beta-oestradiol (E2), oestrone (E1) and progesterone (P) were studied in 483 women over a period of 13 yr (6 yr before and 7 yr after the start of definitive amenorrhoea, defined as the last menstrual bleeding). The patterns for these parameters were established on the basis of the results of 1227 gonadotrophin and steroid determinations and 721 endometrial biopsies. Three periods were identified. During the first, from year-6 to year-3, gonadotrophin levels increased gradually, while those of E2 remained normal, with peaks in some cases. Mean plasma P levels were within the normal range until year-3, but they then decreased progressively. Endometrial histology was similar to that observed during reproductive life. In the second period, from year-3 to year+1, there was a concomitant rise in gonadotrophins as the E2 and P levels decreased. However, at the start of definitive amenorrhoea, the mean E2 and P levels fluctuated between 60 and 100 pg/ml and between 2 and 3 ng/ml, respectively. The endometrium reflected this decrease in E2 and P production. It was not atrophic but proliferative when definitive amenorrhoea commenced. During the last period, from year+1 to year+7, gonadotrophins reached a plateau at high levels, while those of E2 continued to fall, reaching very low values at year+4, after which they reached a plateau. P levels were at the detection limit of the technique. The correlations between all plasma steroid levels and endometrial histology demonstrated discrepancies in 30% of cases: proliferative or hyperplastic endometria were seen at E2 levels of under 60 mg/ml, atrophic endometric at E2 levels of over 60 pg/ml and secretory endometria at very low P levels.

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.

Dissociation between testicular morphogenesis and functional differentiation of Leydig cells.

The aim of the study was to determine whether Leydig cells differentiate in vitro in gonads in which the formation of seminiferous cords is prevented by culture in a medium containing fetal calf serum. Appearance of 3 beta-hydroxysteroid dehydrogenase-positive cells and release of testosterone in the medium occurred at the same age irrespective of whether or not the gonads developed seminiferous cords. It is concluded therefore that testicular morphogenesis with the formation of seminiferous cords is not a prerequisite for the emergence and functional differentiation of Leydig cells.