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Biomedical subjects

J Lefebvre

Publications and source records attributed to J Lefebvre.

At least 163 records · Page 9Linked to original sources

[Antidiuretic hormone levels (arginine-vasopressin) in cases of peripheral hypothyroidism. 26 cases].

Plasma arginine-vasopressin (AVP) levels were measured by radioimmunoassay in 26 untreated myxoedematous patients and 27 healthy subjects. In 22 patients, in spite low osmolality AVP values were not significantly different from those found in controls, but they were considerably increased in 4 patients with severe myxoedema and very low osmolality. Statistical analysis showed negative correlation between AVP values and osmolality in the patients. On the other hand, no correlation was found between AVP values and aldosterone or plasma renin activity values. These results suggest inappropriate secretion of antidiuretic hormone in myxoedema.

Aged↗

[Study of antidiuretic hormones (arginine vasopressin) in 24 cases of primary adrenal insufficiency].

24 Addisonian patients were compared to 27 healthy subjects. Radioimmunoassay of plasma antidiuretic hormone showed higher concentrations of Arginine-vasopressin (AVP) in Addisonians than in normals, in spite of lower natremia and plasma osmolality. Statistical analysis showed a negative correlation between AVP and osmolality in Addisonian patients. On the other hand, no correlation was found between AVP and cortisol, or AVP and PRA. These results suggested an inadequate secretion of antidiuretic hormone in Addison disease. Under substitutive treatment, glucocorticoids alone didn't completely lower AVP concentration which was only normalized after administration of mineralocorticoids.

Addison Disease↗

Nuclear estradiol-binding sites in human breast cancer.

The binding of estradiol to nuclear fractions extracted from human breast carcinomatous tissue was demonstrated. The material, which was extracted with KCl, had an approximate molecular weight of 37,000 and bound estradiol with both high and low affinity (Kd congruent to 1 nM, type A receptors; Kd congruent to 30 nM, type B receptors) as calculated according to the method of Scatchard. Competition studies indicated that both components were specific for estradiol, and among the 134 tumors studied the receptors were found to be linked in almost all cases. Thirty-six % of the tumors were nuclear receptor positive. Cytoplasmic estradiol and progesterone receptors were also measured. Among the cytoplasmic tumors positive for cytoplasmic and progesterone receptors, 37% were devoid of both types of nuclear receptors; this may explain the failure of endocrine therapy in some cases. The determination of nuclear binding sites in human breast tumors appeared to be an interesting criterion for the assessment of estradiol-dependent cell growth.

Adenocarcinoma↗

[Glucagonoma with diabetic ketoacidosis; case report].

Diabetic ketoacidosis is an extremely rare manifestation of glucagonoma. We report such a case in a 72-year-old woman known to be diabetic for seven years. The patient was admitted with diabetic ketoacidosis and associated necrolytic migratory erythrema which suggested the diagnosis of glucagonoma. Plasma glucagon levels were increased (569 to 2298 pg/ml). A vascular tumor of the head of the pancreas without obvious hepatic metastases was visualised by angiography. Duodeno-pancreatectomy including the head of the pancreas led to complete recovery of the mucocutaneous lesions and the plasma glucagon level fell (229 pg/ml). The tumor had several histological characteristics suggesting malignancy and a high glucagon content on extraction. Electron microscopy showed multiple A cells and a few isolated B cells. Most of the cells showed immunoreactivity with anti-glucagon and anti-glicentine antibodies. Three months after surgery, the diabetes was again required treatment with insulin. Plasma glucagon level was again increased and chemotherapy with dimethyltriazenimidazolecarboxamide was undertaken.

Adenoma, Islet Cell↗

Dihydropteridine-reductase activity in breast cancer. Preliminary report.

The dihydropteridine-reductase activity was measured in 206 breast cancers. Large variations were found: 6% of tumors showing high values closed to those noted in liver, whereas the main group has activities of same magnitude of that in cultured fibroblasts. Significant correlation appeared between dihydropteridine-reductase activities and hormonal dependence, as measured by cytosolic estrogen receptor sites.

Breast Neoplasms↗