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Biomedical subjects

C Calmettes

Publications and source records attributed to C Calmettes.

At least 73 records · Page 4Linked to original sources

[Tests of stimulation of calcitonin secretion. Value in medullary cancer of the thyroid].

The detection of high circulating levels of calcitonin is a most valuable procedure to diagnose advanced cases of medullary carcinoma of the thyroid. However, the diagnosis of a primitive tumor in the early stages of development (as in cases of the familial form of the disease) or of a metastasis following ablation of the tumor is more difficult. In the latter cases, the levels of circulating calcitonin may be within normal limits, and for diagnosis one must then resort to tests to stimulate the secretion of calcitonin. We are reporting from our personal experiences the advantages, disadvantages and inconveniences of the three most well-known tests. All patients responded positively to administration of calcium or pentagastrin. The alcohol test, however, produced inconsistent results.

Adult

[Heterogeneity of human calcitonin].

Chromatographic analysis of plasma, urine and tumour tissues extracted from medullary cancer patients demonstrates the existence of immunoreactive calcitonins with higher molecular weight than that of the monomer hormone.

Calcitonin

[Heterogeneity of immunoreactive calcitonin in the plasma of patients with bone marrow cancer].

Plasma from patients with medullary carcinoma containing very high levels of immunoreactive calcitonin were fractionated by filtration on Sephadex gel. In all cases the elution gave four immunoreactive fractions. Two of these fractions correspond to the volume of elution of the monomere and of the dimere of human calcitonin. The two other fractions emerge at an elution volume corresponding to much higher molecular weights. After stimulation of calcitonin secretion in vivo, by dynamic tests, the fractions corresponding to the monomere and dimere increase more strongly than the two other fractions. Preliminary studies of secretion, in vitro, of calcitonin by medullary carcinoma tissue, show the presence in the incubate of four immunoreactive forms having the same elution characteristics as those found in the plasma. The significance of these results is discussed.

Bone Marrow Diseases

An uncommon apudoma: a functional chemodectoma of the larynx. Report of a case and review of the literature.

The authors report a case of laryngeal chemodectoma in a 53-year-old man who died from general dissemination and lymphatic and subcutaneous metastases. This functional neoplasm secreted calcitonin revealed by fluorescence and biochemical tests and perhaps adrenaline-like substances. Its cells looked like the light chief cells of the human carotid body; they contained secretory granules and lysosomal formations. Thirty similar cases had been previously reported. The superior laryngeal glomi and more occasionally the inferior ones were the seat of these tumours which occurred with an equal frequency in both sexes. A hoarseness was often the unique symptom noticed during the several months or years preceding the first examination of this slow growing neoplasm. Nevertheless among the chemodectomas of the head and the neck region those arising in the larynx had the highest incidence of malignant evolution. Five of the patients presented a general dissemination, two had lymphatic metastases and one a local recurrence. The ultra-structural features and sometimes the rarely detected functional activity of these chemodectomas are those of apudomas whose cells might originate from the cephalic portion of the neural crests.

Age Factors

[Multiple endocrine neoplasms type 2. Recent aspects].

Multiple endocrine neoplasia type 2 (MEN 2) is transmitted as an autosomal dominant trait, with 3 different forms. MEN 2a consists of medullary thyroid carcinoma, phaeochromocytoma(s) and hyperparathyroidism. In MEN 2b, parathyroid hyperplasia is absent, but a Marfan-like syndrome and neuromas of the mucosae are present. In some families, the only manifestation of MEN 2 is a medullary thyroid carcinoma. These 3 forms seem to related to one or several gene(s) located in the pericentromeric region of chromosome 10. The histological lesions of MEN 2a are multifocal, bilateral and associated with hyperplasia (which affects C-cells in the thyroid gland). Screening for familial medullary thyroid carcinoma is based upon plasma calcitonin levels measured before and after a pentagastrin stimulation test. The demonstration of DNA markers near the gene(s) of the disease in chromosome 10 pericentromeric region makes it possible to identify, with good probability, the subjects at risk for the disease. It is only by determining the responsible gene(s) that subjects carrying the hereditary anomaly will be identified directly, without marker assays.

Adrenal Gland Neoplasms