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Biomedical subjects

J J Legros

Publications and source records attributed to J J Legros.

At least 19 recordsLinked to original sources

[Oxytocin and maternal stress during the post-partum period].

Oxytocin is required for lactation by promoting milk expulsion. Oxytocin has also been reported to exert a positive role in social attachment. The postpartum period has been shown to be crucial for maternal behavior initiation, and required self-trust reinforcement. However, this period is also remarkable for the high risk exposure of either psychic or physical stress. A negative impact on young mother is suspected, both in the short, medium or long term, which can even be deleterious for child-mother relationships. During lactation in female rats and sheep, oxytocin production has been proved to decrease stress-induced hormonal changes and later consequences. In human beings, only the first hour after breast-feeding seems to protect against physical or psychic stress. Oxytocin improves the stress-induced response by reducing the ACTH and cortisol secretion thus representing a potential therapeutic pathway in post-partum pathologies such as depression. Thus, this review of recent literature about oxytocin and stress during post-partum period, leads to the assumption that oxytocin, at the moment of installation of breastfeeding, acts not only on the physiological condition, but also on the psychic condition of the mother.

Adult↗

AVP- and OT-neurophysins response to apomorphine and clonidine in major depression.

A number of studies have reported abnormalities of neurohypophyseal secretions in major depressive disorder. The purpose of the present study was to test the influence of apomorphine and clonidine injections on plasma vasopressin (AVP)-neurophysins and oxytocin(OT)-neurophysins levels, as direct index of posterior pituitary activation in major depression. Apomorphine and clonidine tests were carried out in 25 medication-free depressive patients and 25 age and gender-matched healthy controls. Blood for neurophysins analysis was drawn by venipuncture at t0, t + 20, t + 40, t + 60 and t + 120. Baseline AVP-neurophysins concentrations were significantly lower in depressives (0.12 +/- 0.14 ng/ml) than in healthy subjects (0.24 +/- 2.15 ng/ml) (p < 0.04). The response to apomorphine test revealed a significant reduced response at 20 (p = 0.01), 40 (p = 0.007) and 60 (p = 0.02) and 120 (p = 0.02)min. Following clonidine test, post hoc tests also revealed a significant decrease at 0 (p = 0.04), 20 (p = 0.01), 40 (p = 0.007) and 60 (p = 0.02) and 120 (p = 0.006)min. Concerning OT-neurophysins, no significant differences were found between depressed and controls in response to clonidine or apomorphine injections. Following clonidine and apomorphine, major depressives exhibited a significantly lower peak GH response than controls. The study supports partially the hypothesis of a reduced vasopressinergic activity in depression. Moreover, we did not find any influence of acute apomorphine or clonidine injections on vasopressin-neurophysin or oxytocin-neurophysin in depressive patients.

Adrenergic alpha-Agonists↗

[Diabetes insipidus in a patient with small-cell lung cancer: a paradox?].

We observed oat-cell lung carcinoma in a man who presented with diabetes insipidus. The chest radiograph showed a suspect nodule within a context of major nicotine addiction. Histopathological examination of the transbronchial biopsy confirmed the diagnosis of oat-cell carcinoma. Brain CT revealed metastasis to the pituitary gland and the pituitary stalk. Vasopressin was undetectable. This case illustrates an uncommon clinical presentation of small-cell lung carcinoma. Oat-cell carcinoma can modify osmoregulation in two different ways. Only sporadic cases of neurogenic diabetes insipidus due to the primary involvement of small-cell lung carcinoma have been reported. More often, this type of lung tumor is associated with inappropriate antidiuretic hormone secretion.

Biopsy↗

Serum melatonin and urinary 6-sulfatoxymelatonin in major depression.

In this study, serum melatonin and urinary 6-sulfatoxymelatonin (aMT6s) were measured in 14 major depressive inpatients, compared to 14 matched controls according to age, gender, season and hormonal treatment in women. Moreover, the relationship between serum melatonin and urinary aMT6s levels was analysed in the two groups. Results indicated that the two groups of subjects showed a clear melatonin rhythm without significant difference in the mean level of melatonin or aMT6s, in the area under the curve of melatonin or in the melatonin peak. However, the time of the nocturnal melatonin peak secretion was significantly delayed in depressive subjects as compared to healthy controls. Moreover, the depressed patients showed urinary aMT6s concentrations enhanced in the morning compared to night time levels, while these concentrations were lowered from the night to the morning in the control group. These results suggest that the melatonin production is phase-shifted in major depression.

Adult↗

Neurohypophysial receptor gene expression by thymic T cell subsets and thymic T cell lymphoma cell lines.

Neurohypophysial oxytocin (OT) and vasopressin (VP) genes are transcribed in thymic epithelium, while immature T lymphocytes express functional neurohypophysial receptors. Neurohypophysial receptors belong to the G protein-linked seven-transmembrane receptor superfamily and are encoded by four distinct genes, OTR, V1R, V2R and V3R. The objective of this study was to identify the nature of neurohypophysial receptor in thymic T cell subsets purified by immunomagnetic selection, as well as in murine thymic lymphoma cell lines RL12-NP and BW5147. OTR is transcribed in all thymic T cell subsets and T cell lines, while V3R transcription is restricted to CD4+CD8+ and CD8+ thymic cells. Neither V1R nor V2R transcripts are detected in any kind of T cells. The OTR protein was identified by immunocytochemistry on thymocytes freshly isolated from C57BL/6 mice. In murine fetal thymic organ cultures, a specific OTR antagonist does not modify the percentage of T cell subsets, but increases late T cell apoptosis further evidencing the involvement of OT/OTR signaling in the control of T cell proliferation and survival. According to these data, OTR and V3R are differentially expressed during T cell ontogeny. Moreover, the restriction of OTR transcription to T cell lines derived from thymic lymphomas may be important in the context of T cell leukemia pathogenesis and treatment.

Animals↗

Effects of androgen substitution on lipid profile in the adult and aging hypogonadal male.

The decrease in serum bioavailable testosterone may be responsible for the catabolic sequelae noticed in the aging man (decrease in libido, decrease in muscle mass, osteoporosis and increase in adiposity). After a brief review of androgen and lipid metabolism as well as their modifications with aging, we discuss current knowledge of the effects of androgen substitution on the lipid profile in hypogonadal men. The results of studies concerning the effect of androgen substitution therapy on lipids are conflicting but might be favorable. The small decrease in high-density lipoprotein cholesterol observed when administering standard dosages of testosterone is accompanied by a significant decrease in total cholesterol (CT) and low-density lipoprotein cholesterol. A counterbalancing of these effects plausibly accounts for the absence of increase cardiovascular risk. The currently available preparations are oral, injectable or transdermal formulations of natural testosterone. The development of new androgen preparations that are more potent, metabolically stable and tissue-specific will improve therapeutic benefits and reduce side effects.

Adult↗

[Influence of androgens on the somatotrope axis: role in the therapy of postandropause osteoporosis?].

Androgens, via aromatization in estrogens, stimulate growth hormone secretion. Their influence on IGF1 (insulin-like growth factor 1, or somatomedin C) are not so clear. Some studies have observed an increase of IGF1 with testosterone therapy and some other not. The way of administration, per os or transdermic, may have an influence, like the hormonal substitutive therapy of postmenopausal women. Oral estrogen therapy decreases IGF1 levels in postmenopausal women and increases GH secretion. IG1 level is variably reduced, unaffected or increased by transdermal estrogen. High dose transdermal estrogen did not affect basal level of IGF1, but reduced the response of IGF1 to GH stimulation. Low dose transdermal estrogen did not alter either baseline or peak IGF1 level.

Androgens↗

[How to explore... insipidus polyuropolydipsia syndrome].

The finding of a polyuropolydispsic syndrome should prompt a complete biological investigation of its etiology. If polyuria can be a minor sign as in psychiatric disorder, it can also be the first manifestation of diabetes mellitus but also central diabetes insipidus, the latter linked to cerebral tumors, metastases in the hypothalamus, granulomatous disease, but also nephrogenic diabetes insipidus such as chronic renal disease or autoimmune disease. Intracellular dehydration is the major risk in case of a polyuropolydipsic syndrome. Prognosis depends on the capacity to maintain water balance through an intact thirst mechanism. After a brief review of the majority of causes of diabetes insipidus, we propose a diagnosis algorithm to easily make the diagnosis.

Diabetes Insipidus↗

[Diagnosis and etiology of hyponatremia].

The unexpected finding of hyponatremia should prompt a clinical and biological investigation to find the etiology. Hyponatremia can be the first manifestation of hyperlipemia, unknown paraproteinemia or the Schwartz-Bartter syndrome. Indeed, a quick diagnosis and appropriate treatment are often necessary to reduce morbidity.

Humans↗

[Management of hyponatremia].

Hyponatremia is the most commonly encountered ionic disorder and, yet, its management remains uneasy. Inappropriate treatment of severe hyponatremia can nevertheless lead to significant neurological damage. The acute (< 48 h) or chronic (> 72 h) character of the disorder must first be determined. Acute hyponatremia is usually observed during a post-operative period and is generally associated with a neurological symptomatology. This requires prompt treatment to avoid cerebral damage. Chronic hyponatremia, on the other hand, needs a slow correction to avoid the "Osmotic Demyelinating Syndrome". In addition to the intensive care of severe hyponatremia, the actual etiology of the disorder must be sought for and therapy adapted to the underlying pathology.

Acute Disease↗

[Early hormonal exposure and behavior effects in congenital adrenal hyperplasia: a case report].

Congenital adrenal hyperplasia is a recessive autosomal transmission endocrine pathology that exposes people who suffer from it to an abnormally high concentration of adrenal androgens during the prenatal and early postnatal periods. This disease induces female's virilism of variable degree. The case of a 29 year-old patient, who suffers from this affection and also presents a psychiatric disorder, raises questions about the possible consequences of an early exposure to androgens on the adult behaviour.

Adrenal Hyperplasia, Congenital↗

[Effects of androgen substitution on lipid profiles in hypogonadal men].

The decrease in serum bioavailable testosterone level may be responsible for the catabolic sequelae noticed in the ageing male (decrease in libido, decrease in muscle mass, osteoporosis and increase in adiposity). After brief review of androgens and lipids metabolism as well as their modifications with ageing, we propose to present the current knowledge of the effects of androgen substitution on lipid profile in hypogonadal men.

Aged↗

The transsexual: what about the future?

Since the 1950s, sexual surgical reassignments have been frequently carried out. As this surgical therapeutic procedure is controversial, it seems important to explore the actual consequences of such an intervention and objectively evaluate its relevance. In this context, we have carried out a review of the literature. After looking at the methodological limitations of follow-up studies, the psychological, sexual, social, and professional futures of the individuals subject to a transsexual operation are presented. Finally, prognostic aspects are considered. In the literature, follow-up studies tend to show that surgical transformations have positive consequences for the subjects. In the majority of cases, transsexuals are very satisfied with their intervention and any difficulties experienced are often temporary and disappear within a year after the surgical transformation. Studies show that there is less than 1% of regrets, and a little more than 1% of suicides among operated subjects. The empirical research does not confirm the opinion that suicide is strongly associated with surgical transformation.

Female↗

Comparisons of two groups of sex-change applicants based on the MMPI.

Out of 29 men asking for a sex-change, 16 reported clinical anamnesis criteria for transsexualism according to the DSM-III-R, a more restrictive diagnosis than the DSM-IV gender dysphoria diagnosis. In addition, all the subjects had taken an MMPI which, of course, did not contribute to the transsexualism diagnosis but which served to describe their personalities. The 16 subjects diagnosed as transsexual and the 13 who did not qualify for this diagnosis were compared on the basis of personality variables measured by the MMPI. Certain differences became evident. The transsexuals systematically complied to cultural stereotypes of femininity without any uneasiness, whereas the nontranssexuals could be subdivided into two groups, those with a vague sense of ill-being linked to a pronounced feminine identity or those with only a slight feminine identity and who showed no particular difficulties.

Adolescent↗

[Urinary excretion of 6-sulphatoxymelatonin in normal subjects: statistical approach to the influence of age and sex].

A radioimmunoassay of urinary 6-sulphatoxymelatonin (a-MT6s) was performed in 90 normal subjects: 44 males and 46 females (17-67 years). Patients treated with betablokers or antidepressants were not included in this study. Urine samples were collected over three periods of time: 7 to 11 p.m., 11 p.m. to 7 a.m., and 7 to 11 a.m. Between 11 p.m. and 7 a.m., the subjects slept in their normal environment and had not ingested alcohol for 24 hours. We searched for a possible relation between urinary a-MT6s excretion (expressed in ng/l/h) and age. From 7 to 11 p.m. and from 7 to 11 a.m. no significant relation could be found. On the contrary, between 11 p.m. and 7 a.m. there was a significant relation indicating decrease of a-MT6s secretion with increasing age. Several linear or non-linear curve patters were tested: Boltzmann sigmoid (1(st), 2(nd), and 3(rd) degree), polynomial curves. The Boltzmann sigmoid showed the best fit judging by the r-squared value (0.152) and the runs test (p=0.64). On this curve the inflection point was located at 53 4 years (SDM, standard deviation of the mean). From 19 to 45 years, the upper sigmoid plateau was located at 1381 91 ng/l/h (SDM). The decrease was found between 45 and 60 years and the lower sigmoid plateau then stabilized at 467 370 ng/l/h (\SDM). In the study group, there was no significant difference between men and women according to the Mann-Withney test. Finally, use of oral contraceptives did not affect urinary a-MT6s (Mann-Withney).

Adolescent↗

[Pituitary diseases in elderly patients with chronic renal insufficiency].

Chronic renal failure (CRF) in the elderly is a cause of multiple endocrine dysfunctions. The three most common pituitary axes involved are the thyrotrope, lactotrope and gonadotrope axes. Thyroid dysfunction may be the consequence of thyroid or pituitary failure. Hyperprolactinemia results in gonadal failure and is present in 30% of patients. Early presentation of menopause and andropause are common in patients with CRF. Sexual hormonal replacement is controversial and must be individually tailored. We propose a systematic screening in the elderly with CRF: determination of TSH, TPO antibodies and cervical palpation, measures of PRL, LH, FSH and testosterone to explore lactotrope and gonadotrope axis.

Aged↗

[Autoimmune polyendocrine syndrome (APS)].

As a complement to basic research, thorough clinical investigation of rare diseases may provide fundamental elements which improve our understanding of still obscure pathophysiologic mechanisms. This is the case with immunoendocrinopathy syndromes. Since Addison's pioneer observations in the 19th century, physicians have known that some individuals and their families may be affected by several spontaneous endocrine insufficiencies that are associated with autoimmune extra-endocrine processes. APS-I or APECED syndrome appears in children firstly affected by recurrent muco-cutaneous candidiasis and hypoparathyroidism, followed by adrenocortical insufficiency and by other autoimmune processes. APS-I is a monogenic disorder resulting from one mutation in the AIRE gene. The protein encoded by AIRE is a nuclear transcription factor the precise target of which is still not known. AIRE is mainly expressed by cells playing a crucial role in the establishment of central T cell self-tolerance (medullary epithelium, macrophages and dendritic cells of the thymus). APS-I must be considered in children affected with recurrent candidiasis without any sign of primary immune deficiency. Scientific investigation of the biological nuclear events controlled by AIRE has to be pursued. Undoubtedly, their deciphering will increase our knowledge of the mechanisms responsible for the establishment of central T cell self-tolerance and will open novel strategies for managing many autoimmune diseases. APS-II is a more common syndrome characterized by adrenocortical insufficiency spontaneously occurring in non tuberculous adults and associated with autoimmune thyroiditis and/or type 1 diabetes. Contrary to APS-I, APS-II is linked to genetic loci of the major histocompatibility complex. There is no adrenal insufficiency in APS-III which includes autoimmune thyroiditis, type 1 diabetes, and other autoimmune extra-endocrine processes (like pernicious anemia and vitiligo).

Adrenal Glands↗

[Oxytocin: a natural means of treating psychological stress].

Oxytocin as an endogenous antistress hormone. The neurohypophysial peptide oxytocin (OT), besides it well known uterotonic and milk ejection activity, share also an inhibitory action on corticotrope activity. This has been demonstrated not only in pharmacological (perfusion) but also in physiological (lactation) conditions. This action is opposite to that of its "sister" hormone vasopressin (AVP) thus bringing arguments favouring the ago-antagonist ying-yang hypothesis. A non pharmacological stimulation of ocytocine secretion, as we have recently demonstrated in a preliminary study, related to hypnosis, could induce a beneficial inhibition of corticotrop axis and needs further rigorous experimental approach.

Adrenocorticotropic Hormone↗