Search PubMed⌕ Search

Biomedical subjects

G Milhaud

Publications and source records attributed to G Milhaud.

At least 163 records · Page 9Linked to original sources

[Hypercalcemia and biologically active parathyroid hormone].

Hypercalcaemia always results in serious clinical sequalae and, if not treated, carries a most unfavourable prognosis. The clinician will gain major diagnostic help from an evaluation of the calcitonin and parathyroid hormone blood levels. With regard to parathyroid hormone we have developed, for the first time, a radioimmunoassay which is specific for the estimation of biologically active hormone in the circulation. We are dealing here with an unusual radioimmunological situation as the immunochemical sites are generally quite distinct from those associated with hormonal activity. We are presenting in this first paper the normal values and also the variations that occur in different types of hypercalcaemia. The comparison of these results with those obtained by the usual methods of estimation for parathyroid hormone assay lacking in biological activity shows the value of this new technique.

Calcitonin↗

Deficiency of calcitonin in age related osteoporoses.

Plasma levels of immunoreactive calcitonin were measured in patients with age-related osteoporosis and with postmenopausal osteoporosis and compared to the levels in control subjects. In all studies immunoreactive calcitonin was lower in the osteoporotic patients. Parathyroid hormone levels were measured in women with postmenopausal osteoporosis and in control women; no difference was observed between the two groups. The results are consistent with the hypothesis that calcitonin but not parathyroid hormone plays a role in postmenopausal and age-related osteoporosis.

Aged↗

Immunological defect and its correction in the osteopetrotic mutant rat.

Congenital osteopetrosis in the mutant rat "op" is accompanied by early atrophy of the thymus gland. The response of thymocytes to concanavalin A and phytohemagglutinin P was greatly diminished at age 28 days, even before pronounced thymic atrophy could be detected. The response of spleen cells to mitogens that stimulate thymus-derived (T) and bone-marrow-derived (B) cells was diminished as early as 35 days of age. A single injection of a suspension of normal bone marrow, which cures osteopetrosis, increased thymus weight and restored the normal responses of both thymus and spleen to various mitogens. These results add further support to the hypothesis that the thymus is involved in the pathogenesis of osteopetrosis.

Age Factors↗

Calcitonin: Its hormonal action on the gill.

When isolated salmon gills were perfused under simulated in vivo conditions, norepinephrine increased and calcitonin decreased the rate of flow of perfusate and the influx of calcium and phosphate through the gill. Only the increased water flow was mediated by beta-adrenergic receptors. Differences in sensitivity to both hormones were observed with gills from prespawning and postspawning salmon; gills from freshwater-adapted fish were less sensitive to norepinephrine and more sensitive to calcitonin, suggesting a decreased production of this hormone in the late stage of the life cycle. The antagonistic effects of calcitonin and norepinephrine on the gill strongly implicate their regulatory role for calcium homeostasis in vivo; the major process being regulated is the influx of calcium into the gill. In fish, calcitonin performs an important role in regulating gill function.

Journal Article↗

Serum thymic factor and the neuromuscular transmission.

The effect of Serum Thymic Factor (FTS) on neuromuscular transmission has been studied in vivo by electromyographic assay. As no modification of muscle tetanus pattern was detected, the involvement of this factor in the pathology of thymus disorders leading to myasthenia is unlikely.

Animals↗

[Arrest of dental development in the osteopetrotic rat and the healing effect of normal bone marrow].

The development of the osteopetrotic "op" rat's mandible was examined from birth to 4 months of age. Before birth the growth of incisors is disturbed and after birth the molar growth stops. Bone resorption is severely reduced and enamel formation ceases soon on the inferior aspect of the incisor, due to degeneration of ameloblasts and lack of vascularisation. A single injection or normal bone marrow cured the disorder at the long bone level within 2-3 months and had a beneficial effect in re-establishing the growth of dental tissue, yet without leading to tooth eruption.

Amelogenesis Imperfecta↗

Correlation between calcitonin and carcinoembryonic antigen levels in medullary carcinoma of the thyroid.

We have detected high values of carcinoembryonic antigen in the blood of patients suffering from medullary carcinoma of the thyroid (MCT). Levels of the antigen and calcitonin, the hormone which is specifically secreted by these tumours, are positively correlated. Stimulation of calcitonin secretion has no effect on carcinoembryonic antigen levels. Though the antigen assay is non specific for MCT, it may improve the diagnosis and follow-up of MCT-patients.

Calcitonin↗

[Pleural and intraspinal tumor with hypercalcitoninemia].

The authors report a case of probably ectopic secretion of calcitonin in a 35 year old woman suffering from a malignant tumour in a double intra- and extra-spinal form. Hormone levels returned to normal after complete excision of the tumour, in which it was impossible to demonstrate the presence of calcitonin despite a very marked secretory appearance by electron microscopy. Study of the literature concerning the secretion of calcitonin by malignant tumours indicates the high degree of contradiction concerning the origin and the significance of increased radio-immunological levels of this hormone, which it is not possible to use without criticism as a "marker" of carcinomas.

Adult↗