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Biomedical subjects

M Roger

Publications and source records attributed to M Roger.

At least 181 records · Page 10Linked to original sources
PubMed1984

Afferent connections of the nucleus posterior thalami in the rat, with some evolutionary and functional considerations.

The afferents to the nucleus posterior thalami were investigated in the rat using the methods of retrograde and anterograde transport of horseradish peroxidase (HRP). The main afferents arise from the following structures: sensorimotor cortex, zona incerta, thalamic ventrobasal complex, pretectum, intermediate and deep layers of the superior colliculus, nucleus suprageniculatus, nucleus ruber and perirubral area, mesencephalic reticular formation, nucleus interstitialis of Cajal, nucleus tegmenti pedunculopontinus, nucleus reticularis pontis, sensorial and spinal tract trigeminal nuclei. There is some confusion about the anatomical localization and appellation of the posterior thalamic region among mammals. In most of them, however, the pattern of afferents to this area appears to be relatively homogeneous. We conclude that the projections to the thalamic posterior nucleus of the rat are similar to those reported in other mammals. This nucleus has been suspected of playing a role in the processing of somaesthetic or visual informations. On the basis of the multimodal nature of its afferents, a specific role of this nucleus is excluded. Instead, a non-specific function of modulation or integration is suggested.

Afferent Pathways↗
PubMed1983

Prolactin and thyrotrophin responses to thyroliberin (TRH) in patients with growth hormone deficiency: study in 167 patients.

Both thyrotrophin (TSH) and prolactin (Prl) were studied under thyroliberin (TRH) stimulation tests in 167 hypopituitary dwarfs out of GH or T4 treatment. TSH and/or Prl responses were either low, normal or exaggerated and/or protracted. Various abnormal patterns were observed in most of the patients with low T4 but also in many patients with normal T4. The TSH response should be considered together with the value of T4. A normal response of TSH with a low T4 reflects a relative TSH deficiency from pituitary or hypothalamic origin. There was no clear relationship between the cause or type of hypopituitarism and the pattern of the responses of either TSH or Prl. The abnormalities of TSH and Prl were not related to each other except in patients with a past history of breech delivery. Then both TSH and Prl have to be measured after TRH in order to obtain full information from the test about hypothalamo-pituitary function. The frequency of the exaggerated and/or delayed or protracted responses of TSH and Prl with normal or low T4 is probably mostly related to hypothalamo-pituitary dysfunction. Abnormal responses of TSH or Prl, seldom of both hormones, were observed in otherwise isolated growth hormone (GH) deficiency, leading to a modification of such a diagnosis after the TRH test. Actually, the TRH test may be useful to ascertain the diagnosis of GH deficiency when the GH responses to provocative tests are borderline.

Adolescent↗
PubMed1983

[Plasma and intrafollicular hormone profiles in the late preovulatory phase. I. Spontaneous cycles].

The hormone state of development in the late preovulatory phase is described in its relationship to the start of the LH surge which occurs 37-39 hours before ovulation. No precise relationship has been found between the oestradiol (E2) peak in the plasma and that which occurs before ovulation. All the same, the succession of hormone events that have been observed in 77 spontaneous cycles is the following: the level of E2 suddenly rises between 35 and 30 hours before the ovulatory discharge and this rise is immediately followed by a rise in the level of LH. Then the plasma concentration of 17-hydroxyprogesterone (17-OHP) increases 5 hours before the LH surge. In the preovulatory follicle 5 hours after the start of the LH surge, a drop in the level of E2 and a rise in the level of progesterone is noted. Concentrations of androgens only lessen in the last 12 hours before ovulation whereas the level of 17-OHP stays stable. We have thus been able to work out the sequence of plasma hormone phenomena that occur in determining whether a preovulatory gonadotrophic surge will occur. We have described the hormone levels in follicular fluid immediately before spontaneous ovulation. These findings will be able to serve as a reference to evaluate the quality of the late preovulatory phase in abnormal cycles or in cycles that have been induced.

Adult↗
PubMed1983

[Strategy for studying mineralocorticoids other than aldosterone in arterial hypertension of hormonal origin].

Deoxycorticosterone (DOC) and corticosterone (B) are two mineralocorticoid hormones, which are both secretory products of the zona fasciculata and precursors of aldosterone in the zona glomerulosa. Hyperproduction of these compounds plays certainly a role in the pathogenesis of Cushing syndrome hypertension. Their levels in plasma are moderately elevated in half cases of tumour or hyperplasia. In some tumors, the ratio B/DOC is lowered and this might be helpful in diagnosing the malignancy. Moreover, certain tumors secrete exclusively corticosterone and/or DOC. The same mineralocorticoids are responsible for the hypertension in congenital 11-beta-hydroxylase defects (where virilism is present) and congenital 17-alpha-hydroxylase defects (where impuberism is present). Thus, measurements of DOC and corticosterone levels are needed in any case of vascular hypertension associated with hypokalemia and non-elevated renin activity, when routine investigations do not provide immediately the right diagnosis.

Adrenal Gland Neoplasms↗
PubMed1982

Plasma and urinary melatonin in male infants during the first 12 months of life.

Plasma and urinary melatonin, testosterone and luteinizing hormones were radioimmunologically assayed in 26 male babies during the first year of life. The results show that plasma melatonin levels are low during the phase of postnatal elevation of testosterone and luteinizing hormones. They subsequently increase when testicular activity decreases. Urinary elimination of melatonin does not vary during this period, suggesting the existence of variations in the synthesis or utilization of melatonin.

Aging↗
PubMed1982

Steroid hormone levels in peritoneal fluid during the periovulatory period.

In order to obtain further information on estradiol (E2) and progesterone (P) patterns during the periovulatory period, their levels were determined in peritoneal fluid (PF) and plasma obtained during 22 laparoscopies performed within the 58 hours following the luteinizing hormone surge-initiating rise (LH SIR) determined by plasma LH assays every 6 hours. E2 levels in plasma and PF did not differ before ovulation (n = 13) but differed after ovulation (n = 9, P less than 0.01). P levels were lower in plasma than in PF before ovulation, but there was an overlap of values. After ovulation the difference was significant (P less than 0.01). When plotted as a function of time following LH SIR, E2 levels increases in PF progressively (r = 0.70), whereas the P increase was discontinuous, with a dramatic rise after follicular rupture. These different patterns may be related to respectively divergent and convergent variations of steroid levels in blood and follicular fluid.

Adult↗
PubMed1982

Endocrine aspects and tumoral markers in intracranial germinoma: an attempt to delineate the diagnostic procedure in 14 patients.

This work outlines the endocrine abnormalities associated with intracranial germinomas (14 patients before treatment). Diabetes insipidus of various intensity was present in all cases. Adipsia is often present as well. In six patients, the first neuroradiologic examination after the onset of DI was normal. Growth hormone secretion was deficient in 11 of 13 patients. Abnormalities of TSH response to TRH were present in nine of ten (four insufficient and five exaggerated responses to TRH). Anterior pituitary dysfunction could not be predicted by the tumor site as determined by radiologic criteria. Tumoral markers have also been studied. Elevated plasma tumoral markers were found in four patients of 11 studied. Tumoral germinoma cells were present in CSF in five patients of ten, in one of them before radiologic confirmation. Pertinent endocrine evaluation and search for tumoral markers was of great value in systematic follow-up of patients with central diabetes insipidus, and could lead to early diagnosis and treatment of the tumor.

Adolescent↗
PubMed1982

Simultaneous study of somatotrophic and corticotrophic pituitary secretions during ornithine infusion test.

An ornithine infusion test was performed in fifty-four children with constitutional short stature. The ornithine infusion induced an elevated level of GH at 45 min (mean value = 873 pmol/l) and a similar rise of cortisol levels (mean value = 544 nmol/l). An important peak of ACTH appeared 15 min before the increase of cortisol. In three panhypopituitary dwarfs studied, no elevation of GH or cortisol was observed. The well tolerated ornithine infusion test allows the simultaneous study of the somatotropic and corticotropic pituitary secretions in children with delayed growth.

Adolescent↗
PubMed1982

Isolation and structural properties of a high-molecular-weight actin-binding protein (filamin-like protein) in hog thyroid gland.

A high-molecular-weight protein has been isolated from hog thyroid gland. This protein, with a molecular weight of 475,000 determined by ultracentrifugation and gel filtration, is a complex of two polypeptides with apparent molecular weights of 250,000 and 240,000. It may be related to filamin-like proteins by its physicochemical properties and its immunogenic cross-reactivity towards gizzard filamin antibodies. Furthermore it interacts with F-actin in a stoichiometry of 1 mol of high-molecular-weight protein/approximately 12-14 mol actin monomer allowing microfilament association, as shown by electron microscopy.

Animals↗
PubMed1982

Dexamethasone-suppressible hypercorticosteronism in two 46,XX subjects with ambiguous genitalia and ovarian cysts. Partial defect of 17 alpha-hydroxylase or 17-20-desmolase.

The paradoxical association of female pseudohermaphroditism and androgen deficiency was observed in two 46,XX subjects with high corticosterone plasma levels. Subject 1 has been declared a boy due to clitoris enlargement; she had no vagina and uterus. Subject 2 had ambiguous external genitalia. In both, at age 27 and 17 years, fusion of outer labia, impuberism, ovarian cysts, and histologically normal ovarian tissue were observed. Blood pressure was normal. Basal cortisol levels were normal but unresponsive to ACTH. Progesterone levels were 40 and 62 ng/ml and rose after ACTH (50 and 79 ng/ml). 17-hydroxyprogesterone levels were 25 and 21 ng/ml and did not rise after ACTH. Corticosterone levels were 70 and 92 ng/ml and rose after ACTH (110 and 180 ng/ml). All three steroids were suppressed by dexamethasone. Androgen and estrogen levels were at or below the lower limit for normal women. The sex steroid levels obtained by radioimmunoassay in plasma and a follicular cyst fluid were confirmed by isotope dilution-mass spectrometry. We suggest that the sexual ambiguousness resulted from an excessive production of gestagenic steroids during fetal life, and that the enzyme defect is either a partial 17 alpha-hydroxylase defect combined with a peripheral production of 17-hydroxyprogesterone, or else a partial 17-20-desmolase defect with a secondary 21-hydroxylase defect limited to the cortisol pathway.

Adolescent↗
PubMed1982

Seasonal influence of diurnal rhythms in the onset of the plasma luteinizing hormone surge in women.

The time of the LH surge onset in plasma was detected in 75 human cycles. The preovulatory LH surge began between midnight and 0730 h in two thirds of the patients. According to the season of study, the LH surge began between 1030 and 2215 h in 52.4% of the spring cycles compared with 12.9% of the cycles studied during other seasons (P less than 0.001). The highest frequency of the LH surge occurrence over a 3-h time interval was 1500 +/- 1.5 h during the spring cycles (28.6%) and 0300 +/- 1.5 h (42.5%) during the other seasons. It was estimated that ovulation occurred primarily in the morning during the spring and primarily in the evening during autumn and winter.

Adult↗
PubMed1982

17 alpha-hydroxylase deficiency syndrome associated with bilateral streak gonads and impaired development of Müllerian ducts derivatives. Report of a case.

We report severe 17 alpha-hydroxylase deficiency in a 17 year-old black girl with 46,XX genotype. The diagnosis was suspected because of primary amenorrhoea, absence of sexual maturation, hypertension and hypokalaemia with renal potassium wasting. Endocrine investigation revealed low basal levels of all steroid hormones which require 17 alpha-hydroxylation for biosynthesis (i.e. glucocorticoids, androgens and oestrogens). No increase in their basal levels was seen following adrenal stimulation, indicating a severe block. Plasma concentrations of ACTH, FSH and LH were elevated as were progesterone, 11-deoxycorticosterone and corticosterone. Plasma renin activity was suppressed and aldosterone levels were very low. After 4 months of glucocorticoid replacement therapy, aldosterone was still low, even though the suppression was otherwise effective. Our case is unusual because bilateral streak gonads and impaired development of Müllerian ducts derivatives were also present. To our knowledge, a similar case has never been reported before.

Adolescent↗
PubMed1982

[Gonadotropic insufficiency associated with the cytomegalic type of congenital adrenal hypoplasia (author's transl)].

Two adolescents with chronic adrenal insufficiency, presumably secondary to the cytomegalic type of congenital adrenal hypoplasia, developed a gonadotropin deficiency at puberty, which was both delayed and incomplete. Endocrine studies demonstrated in plasma low LH levels which failed to increase after LH-RH, higher levels of FSH, low basal testosterone concentration but increasing normally after HCG stimulation. Azoospermia was demonstrated in one case. In parallel with those previously reported, these two new cases show that the association between gonadotropin deficiency and congenital adrenal hypoplasia is not accidental, even if the relationship between the two components of the syndrome is still unclear.

Adrenal Insufficiency↗
PubMed1981

Interpretation of plasma luteinizing hormone assay for the collection of mature oocytes from women: definition of a luteinizing hormone surge-initiating rise.

Analysis of plasma luteinizing hormone (LH) assays (4 assays per day) permits the discernment of the onset of the physiologic effects of ovulatory release. This threshold value of LH plasma concentration (LH surge-initiating rise, LH SIR) is determined for each cycle in terms of the average baseline level of the previous day. The chronology of follicle and oocyte maturation after LH SIR is similar to that which follows chorionic gonadotropin (hCG) administration: none of the 20 patients, compared with 2 out of 10, had ovulated when laparoscopy was performed 30 to 35 hours and 36 to 38 hours after LH SIR time, respectively; 1 out of 3, 9 out of 14, and 5 out of 5 patients had an in vitro fertilized egg when oocytes were collected 30 to 32, 33 to 35, and 36 to 38 hours after LH SIR time, respectively. Thus the oocyte can be collected 34 to 35 hours after the LH SIR; at this point ovulation has not occurred and the oocyte is capable of being fertilized.

Adult↗