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Biomedical subjects

B Ducornet

Publications and source records attributed to B Ducornet.

12 recordsLinked to original sources

[Partial 3-beta-hydroxysteroid dehydrogenase deficiencies].

An overview of the partial 3 beta-hydroxysteroid dehydrogenase deficiency is presented. The classical, congenital or early postnatal form is characterized by a salt-losing syndrome and/or ambiguous genitalia. The late-onset forms, only recognized for the last ten years and diagnosed with an increasing frequency, are to be systematically suspected in the presence of clinical hyperandrogenism with or without oligomenorrhea. This deficit, involved in both adrenal and gonadal tissues, seems to be transmitted by an autosomal recessive gene. An ovarian 3 beta-hydroxysteroid dehydrogenase deficit can be a primary cause of some cases of polycystic ovary syndrome and the relations with this affection are disputed. The increased ratios of delta 5 steroids/delta 4 steroids ensure the diagnostic conviction while the elevated ratio of 17-hydroxy-pregnenolone/17-hydroxyprogesterone and the normal ratio of 11-desoxycortisol/cortisol allow to eliminate the possibility of a 21-hydroxylase or 11 beta-hydroxylase deficiency, respectively. The treatment is based above all on the glucocorticoid utilization, which can lead to the return of menses and the ovulatory function, but the cutaneous symptoms of hyperandrogenism will be better controlled by cyproterone acetate out of situations of stress.

3-Hydroxysteroid Dehydrogenases

[Stress and immunity. The role of stress in auto-immunity of Basedow's disease].

The possible influence of stress on the immune system, long since suspected by the clinicians in their daily practice, was confirmed by human and animal studies, some of which being recent. Stress generally exert an immunosuppressive effect, but some of its characteristics (nature, duration, intensity, controllability of the stressing situation) can modulate this response, amplifying or reversing it. The concerned mechanisms are complex, involving the autonomic nervous system, the hypothalamo-pituitary complex and its target-glands through hormonal receptors born on immunocompetent cells. The immune system, conversely, is able to inform the brain about the interference of non cognitive stimuli (viruses, bacteria, tumors) through immunologic cell-derived immunohormones active in the central nervous system. Thus, close immune-neuroendocrine interactions exist, in order to cope with stress of all kinds. The stress can act in Graves' disease by depressing the T suppressive function via the hypothalamo-pituitary-adrenal axis, by eliciting the secretion of catecholamines capable of initiating an hyperthyroidism, by facilitating through its immunosuppressive action a viral infection that can have a part in initiating the auto-immune process.

Autoimmunity

[Improvement of the prognosis of Basedow's disease by using high doses of carbimazole].

The influence of synthetic antithyroid drug dosage on the course of Graves' disease was evaluated by comparing two groups of matched patients treated with carbimazole. Thirty-seven patients received a rapidly degressive treatment (60 mg/day initially rapidly reduced without replacement thyroid hormone therapy), and 36 patients received a prolonged treatment in high doses (60 mg daily for 6 months with progressive reduction of dosage over 5 months and replacement therapy). There was a highly significant difference in the actuarial curves of patients without relapse during 36 months: 82 per cent in patients with high doses, as against 38 per cent in patients with rapidly degressive treatment (log rank: chi 2 = 7.67, P less than 0.01). The anti-TSH receptor antibody titers decreased more rapidly in patients under prolonged treatment with high doses than in those with the rapidly degressive treatment. It is concluded that carbimazole in high doses is more immunosuppressive than in rapidly degressive doses and that it improves the prognosis of Graves' disease.

Adult

[Puberty].

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Adolescent

[Malignant pheochromocytoma. A case].

A case of malignant phaeochromocytoma is reported. The primary tumour was removed in 1970. Metastases were diagnosed in 1979 and management of the condition included antihypertensive treatment with alphamethylparatyrosine, antitumoral chemotherapy and surgical reduction of secreting tissue. In these rare tumours malignancy can only be confirmed by metastases, i.e. presence of chromaffin cells in loci where they are not usually found. Histology is of little value. High levels of catecholamine precursors or their metabolites in the urine may be a sign of malignancy, but some asymptomatic tumours are only revealed by metastases. Computerized tomography and radioisotope scanning with I131 metaiodobenzylguanidine are the best available methods to locate the lesions. In view of the small number of cases and of the unpredictable course (sometimes spread over many years) of malignant phaeochromocytomas, the effectiveness of treatments with alphamethylparatyrosine, chemotherapy and radiotherapy is difficult to evaluate.

Adrenal Gland Neoplasms