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Biomedical subjects

G Milhaud

Publications and source records attributed to G Milhaud.

At least 127 records · Page 7Linked to original sources
PubMed1981

[Effect of vasoactive intestinal peptide (VIP) on prolactin secretion in man].

The effect of Vasoactive Intestinal Peptide (VIP) on plasma prolactin has been tested in two human subjects. When perfused at low doses (few micrograms per minute), VIP increased the prolactin levels in both sexes, the response being more important in Woman (3.5-fold over basal) than in Man (2-fold). VIP may be a physiological regulator of prolactin release in humans. This peptide may be a specific tool for the clinical investigation of the prolactin function.

Adult↗
PubMed1981

Osteopetro-rickets: a new congenital bone disorder.

Two lethal mutations have been described in the rat: "osteopetrosis" (op) and "toothless" (tl). The op mutant can be cured by normal bone marrow infusion, while the tl mutant cannot. We report here additional data with regard to the tl mutant. The bone disease of the tl rat as in the op rat is associated with a precocious thymic atrophy, but bone lesions are quite different. In addition to classical osteopetrosis, the tl rat displays several features of rickets: broadening of the extremities of long bones, thickening of the epiphyseal plates, presence of osteoid areas. In addition, the persistence of embryonic characters, evidenced by high levels of alpha-fetoprotein, suggests that the developmental defect of bone is part of a more general process.

Alkaline Phosphatase↗
PubMed1981

Characterization of specific receptors for calcitonin in porcine lung.

The binding of salmon calcitonin was investigated in subcellular fractions obtained from normal porcine lung. Only the membrane fraction (density, 1.14 g/cm3) showed specific binding for calcitonin. Specific binding of 125I-labeled salmon calcitonin was competitively inhibited by concentrations of unlabeled homologous hormone in the range 0.01-1 nM. Half-maximal inhibition of binding was observed with 0.12 nM salmon calcitonin. Scatchard analysis of the data suggested the presence of one class of binding sites with a mean affinity constant of 0.9 X 10(10) M-1 and a mean receptor number of 40 X 10(8)/mg of protein. The binding of salmon calcitonin was highly specific; half-maximal inhibition of binding was observed with 63.8 nM bovine calcitonin, the hormone corticotropin having no effect in this system.

Animals↗
PubMed1981

Influences of fixatives on the immunodetection of calcitonin in mouse "C" cells during pre- and post- natal development.

The presence of calcitonin in fetal and postnatal mouse "C" cell was demonstrated by radioimmunoassays of fetal and adult thyroid extracts and by immunohistochemistry following the use of Bouin's fixative from 18 days postcoitum onwards. However, after fixation with formaldehyde no calcitonin could be detected in fetal or early postnatal samples, although it was still easily detectable in adult tissues treated with this fixative, raising the possibility that there may be age-dependent differences in the chemistry or physiological state of intracellular calcitonin. Experiments conducted with several other fixatives and the results of the radioimmunoassays suggest that the loss of calcitonin reactivity is not due to differences in the anti-genic sites of the molecule at the two stages in development. Neither can the positive detection of fetal material treated with Bouin's fixative be due to any action of this liquid. However, the inhibiting action of the aldehydes could be related to the preservation of the granule membranes in the fetal "C" cells: our ultrastructural studies show that the granules can be morphologically classified in dense-core and homogeneous matrix. Such granule membranes are abundant in the young and adult "C" cell and would be reactive, while the small dense-core granules are prevalent in the fetus and would be unreactive, confirming the hypothesis of a difference of structure of the granule membrane and not of calcitonin between fetal and late postnatal "C" cells.

Acetates↗
PubMed1981

[Method of toxicological research of anticoagulant rodenticides (author's transl)].

The analytical method which is described enables to detect principal anticoagulants presently used in France as rodenticides. Its particularity lies in using a mixture of iso octane and dichloromethane 95/5 (V/V) in the extractive part whose output varies according to the compounds from 80 to 25 per cent in supplemented liver. Besides thin layer chromatography which is used to achieve identification and semi quantitative evaluation, spectrometric measurement can be carried through to confirm identity and precise quantity with more accuracy. Sensitivity varying according to compounds, it is possible to detect products whose minimum concentration in biological materials is between 1 and 5 ppm.

Anticoagulants↗
PubMed1981

[General schema for safety evaluation of residues of embryotoxic drugs (author's transl)].

Concerned with adapting the withdrawal time to real risks attributed to residues, the authors present a general schema of evaluation based on the metabolism-toxicity relationship. This schema takes into account: a) possible distinction between potentially toxic and atoxic metabolites for extractable residues, b) the more or less large biovailability of residues, c) the methodological evaluation difficulties of toxicity of bound residues. Without neglecting public health, this procedure leads to less constrained restrictions in use of veterinary drugs.

Abnormalities, Drug-Induced↗
PubMed1980

Effects of thymic factors on growth of experimental tumors.

The effects of thymic factors on the growth of a chemically induced tumor have been studied. The thymic factors were obtained by a gentle isolation procedure which minimizes loss of material and biological activity. The administration of the thymic factors neither influenced the development or growth of the tumor nor the weight of the thymus or the spleen. A bigger thymus and a smaller spleen were observed in animals rejecting the tumor, whether or not they received the thymic factors.

Animals↗
PubMed1980

Calcitonin, a major gill hormone.

Isolated salmon gills, under simulated in vivo conditions, transported calcium ion into the ambient seawater when perfused with Ringer's solution containing salmon calcitonin. Similar enhancement of phosphate efflux was observed. Calcitonin caused simultaneous decreases in perfusate flow rates. The effects act synergistically to diminish net plasma calcium concentrations.

Animals↗
PubMed1980

[Thymus and bones].

Rat congenital osteopetrosis and cyclophosphamide (an immunosuppressive drug) induced osteocondensation are useful experimental models for the understanding of the relationships which seem to exist between thymus and bone. The high levels of seric alphafetoprotein found in the osteopetrotic tl rat raise the question of the persistance of embryonic characters in congenital osteopetrosis.

Animals↗
PubMed1980

Plasma immunoreactive N-terminal parathyroid hormone and cyclic AMP and cyclic GMP urinary levels in man after I. M. administration of two different doses of porcine calcitonin.

The effects of acute porcine calcitonin (pCT) administration were studied in 11 healthy volunteers with no metabolic disease. Each subject was given, intramuscularly, 1 MRC unit of pCT in glycine vehicle, 160 units of pCT in gelatine vehicle, and placebo, according to a crossover design. The following parameters were studied: blood calcium, phosphorus and immunoreactive parathyroid hormone (iPTH); urine calcium, phosphorus, cyclic AMP and GMP. Both the pCT preparations produced, at the same time after administration, a hypocalcemic effect (P less than 0.01) which was not dose related, without any modification of urinary calcium excretion, implying that both doses are able to inhibit completely bone destruction. Despite the blood calcium decrease, no significant modifications in plasma iPTH levels were observed. pCT administration did not modify the urinary excretion of cyclic AMP, while it increased the urinary levels of cyclic GMP, particularly at the higher dose employed. Blood phosphorus decrease and urinary phosphate excretion increase were observed only after the administration of 160 MRC units of pCT. These observations suggest that the effects on urinary cyclic GMP and on blood and urine phosphorus are not mediated by PTH but could be the result of a direct action of calcitonin seen only when high doses are employed. In conclusion, one MRC unit of pCT is sufficient to inhibit bone resorption.

Adult↗
PubMed1980

Physicochemical characteristics of carcinoembryonic antigen extracted from medullary carcinoma of the thyroid.

Carcinoembryonic antigen (CEA) and calcitonin (CT) were extracted from medullary carcinoma of the thyroid (MCT) tissues, fractionated on Sephacryl S-200 and chromatographed on Concanavalin A. CEA purified from MCT is closely related to CEA extracted from colonic tumors. It has an equivalent molecular weight, is a glycoprotein and has a similar electrophoretic mobility in both SDS and basic polyacrylamide electrophoresis. A certain degree of heterogeneity is present in the form of a smaller molecular weight component. Large molecular forms of CT which are present in MCT tissues and which co-elute with the minor component of CEA on Sephacryl chromatography can be separated by Concanavalin A chromatography.

Carcinoembryonic Antigen↗