Search PubMed⌕ Search

Biomedical subjects

C Bohuon

Publications and source records attributed to C Bohuon.

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

[Biological markers for tumours of the testis. Their use in diagnosis, prognosis and follow-up in 200 cases (author's transl)].

Repeated measurements of serum chrionic gonadotrophic hormone (CGH), of its beta sub-unit (beta CGH) and of alpha-foetoprotein (aFP) were performed in 200 patients with germinal tumours of the testis. CGH levels were found to be high in 43,5% of patients, particularly those with choriocarcinoma (a rare tumour) or with embryonal carcinoma with syncytiotrophoblastic (ST) cells. They were also high in 24% of patients with histologically pure seminoma, which throws doubts on the homogeneity of this group of tumours and raises problems concerning their treatment in patients with high CGH. aFP levels were increased in 38% of all patients, particularly those with ST cell embryonal carcinoma (62%) or with malignant teratoma (56%). These biochemical markers may point to a histological diagnosis. They also have prognostic value and are essential for monitoring during treatment. Pre-operative assays are to particular interest and should be performed in every case.

Adult↗
PubMed1981

Biochemical tests for diagnosis of phaeochromocytoma: urinary versus plasma determinations.

Fifteen patients with hypertension due to phaeochromocytoma and 35 controls with essential hypertension were studied to assess the diagnostic value of urinary and plasma biochemical determinations in phaeochromocytoma. In every case of phaeochromocytoma the urinary concentration of vanillylmandelate, metanephrines, or adrenaline plus noradrenaline was diagnostic of the disease irrespective of whether the patient was normotensive or hypertensive at the time. Plasma determinations of adrenaline and noradrenaline, however, gave falsely negative results on three occasions. These findings suggest that urinary biochemical determinations--particularly of metanephrines--are more reliable than plasma catecholamine measurements as a test for phaeochromocytoma. The test is particularly useful in patients with intermittent hypertension.

Adrenal Gland Neoplasms↗
PubMed1981

Catechol-O-methyl transferase activity in human mononuclear cells.

Catechol-O-methyl transferase (COMT) activity was investigated in human peripheral mononuclear cells and in human lymphoblastoid cells lines. In any case, we have detected enzymatic activity in the membrane fraction of the cells. Km was found to be 4-9 10(-6) M and the enzyme was inhibited by tropolone and the lack of magnesium. The eventual association of COMT with adrenergic receptor-adenylate cyclase system in mononuclear cells is discussed.

Adult↗
PubMed1980

[Radio-immunoassay of antidiuretic hormone. Choice of a technic of extraction, Normal and pathological values (author's transl)].

The low serum concentration of ADH requires extraction prior to assay. Various methods are compared (direct extraction by acetone, adsorption on talcum powder. Florisil, silicilic acid, Fuller's earth, QUSO, carbon-dextran, adsormone, then elution with hydrochloric acetone). The technic finally used was extraction with Florisil. The antibody used was commercially accessible. The separation of bound from free hormone required a second antibody fixed on Sephadex (DASP). The usual values found in 31 normal subjects from 22 to 89 years were: 7,4 . 4,1 pmol/l (M 2 sigma) 1 pmol/l = 1,08 pg/ml. These assays were carried out on tissue extracts prepared by mashing tumour fragments or lymph nodes removed from a patient with the Schwartz Bartter syndrome. They showed the existence in these tissues of high concentrations of ADH immunologically identical with that present in the serum of normal subjects.

Adsorption↗
PubMed1979

[Plasma renin and noradrenalin levels during hypotensive therapy using acebutolol (author's transl)].

The effects of acebutolol (800 mg per day for three days) on pulse rate, blood pressure, plasma noradrenaline and plasma renin activity were measured in nine patients with essential hypertension, at rest in a horizontal position, after five minutes standing upright and after walking for one hour. Acebutolol reduced pulse rate, blood pressure and plasma renin activity in all three positions. Treatment has no influence on plasma noradrenaline in a horizontal position, but significantly reduced its orthostatic stimulation. The inhibition of noradrenergic response to an orthosatic position is compatible with a central or presynaptic effect of acebutolol. This effect would not appear to be essential to its antihypertensive action since acebutolol reduced blood pressure but not plasma noradrenaline in a horizontal position. Blood pressure response to treatment was positively correlated to initial values of plasma renin activity measured after walking for one hour and plasma noradrenaline measured after five minutes in an orthostatic position. On the basis of this correlation, measurement of these two hormonal indices is of predictive value, within the limits of a short period of treatment with acebutolol and strictly defined hospital conditions.

Acebutolol↗
PubMed1979

Purification and properties of human erythrocyte delta-amino-levulinic acid dehydratase (EC 4-2-1-24).

Human delta-aminolevulinic acid dehydratase (ALA-D) was purified 9 000-fold by salt precipitation, ion-exchange chromatography and gel filtration. These methods resulted into an electrophoretically and immunologically pure protein. The optimum pH of the enzyme is 6.6 and its Km with ALA : 4.8 X 10(-4) M. The enzymatic activity was increased by thiol-containing substances, such as dithiothreitol (DTT), which protect the -SH groups of the protein. Zinc, a portion of the enzyme molecule, was partly lost during the purification procedure; its addition enhances the enzymatic activity. Determination of molecular weights and electron microscopy study are in favor of an octameric structure.

Animals↗
PubMed1977

[Estrogen and progestogen cytosol receptors in human breast carcinoma (author's transl)].

The authors have studied Estrogen (RE) and Progestin (RP) cytosol receptors in 379 human breast carcinomas: 281 tumors suitable for surgery, 26 pseudo-inflammatory tumors, 52 metastases and 20 recurrences. They have used an exchange technique with estradiol for RE and a synthetic compound, R 5020, for RP. The results point out that high rates of RE correlate with post-menopausal women and high rates of RP with pre-menopausal women. Tumours are considered receptor-positive when the binding sites concentration exceeds 100 fmoles/g tissue. Using this as a base 32% of the tumors are RE and RP negative. Considering only the positive tumors, 54% contain both receptors, 31% only RE and 15% only RP. The percentages are also given in terms of the hormonal state of the patients. The results are discussed in terms of McGuire's hypothesis that both receptors are necessary to obtain a positive response to hormonal therapy. Correlation between histology and receptors is also discussed.

Breast Neoplasms↗
PubMed1977

[Estrogen and progresterone receptors in male breast diseases].

The authors study estrogen (RE) and progestogen (RP) receptors by an exchange technique in 8 cases of male breast carcinoma and 7 cases of gynaecomastia. Tumours are considered receptor positive when the binding sites concentration exceeds 100 fmol/g tissue. Using this as a base all the carcinoma are RE+ and 7/8 are RP+. Gynecomastia are always RE- and RP- except for one case which is RP+. RE and RP levels are correlated with the degree of differentiation of the carcinoma, as determined histologically.

Adenocarcinoma↗