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Biomedical subjects

B Chevallier

Publications and source records attributed to B Chevallier.

159 records · Page 9Linked to original sources

Bovine retina contains three growth factor activities with different affinity to heparin: eye derived growth factor I, II, III.

Several ocular tissues have been shown to contain growth factor activity designated under a generic name as Eye Derived Growth Factor. Purification from bovine retina was undertaken and a fraction which could induce target cells to proliferate at doses of 5 ng per ml of culture medium was obtained. Using heparin sepharose chromatography we now show that this mitogenic activity can be fractionated into three different activities. Crude extract of bovine retina used as starting material was separated into two major fractions, one with no affinity for heparin and which was named Eye Derived Growth Factor III, and one with a strong affinity for heparin and eluted from the column with 1.4 M NaCl named Eye Derived Growth Factor I. This fraction EDGF I induces cell proliferation at doses of 100 pg/ml of culture medium. A 10(5) fold purification was achieved by this single chromatography step. Cibacron Blue purified EDGF was also further fractionated by heparin sepharose. All biological activity was found to bind to heparin. One fraction eluted at 1 M NaCl named Eye Derived Growth Factor II had a biological activity at doses of 1 ng while the other growth factor was the EDGF I with biological activity at 25 pg. At this step of purification EDGF I runs as a single band on SDS polyacrylamide gel at a molecular weight of 17 000 d. These data strongly suggest that Eye Derived Growth Factors I and II are respectively similar to Brain Fibroblast Growth Factor and to Endothelial Cell Growth Factor from hypothalamus.

Animals↗

Do patients with low tension glaucoma have particular cardiovascular characteristics?

It has been suggested that low tension glaucoma (LTG) could be the consequence of a hemodynamic crisis or chronic occlusive disease. The purpose of the present study was to test this hypothesis by comparing three groups of patients matched for age and sex: 51 patients with LTG, 51 patients with open angle glaucoma (OAG) and 46 control patients. Clinical symptoms and history of occlusive arterial disease and conditions which could be associated with or were the consequence of acute blood pressure lowering were not more frequent in the LTG group. The prevalence of rhythm and conduction abnormalities on the ECG was two times more frequent in the glaucoma groups, but the differences were not statistically significant. Mean cardiovascular risk factor levels were not higher in the LTG group than in the two other groups. But the mean difference of blood pressure between the standing and lying positions was significantly greater in the LTG group (systolic blood pressure: -6.9 mm Hg) than in the OAG group (-1.2 mm HG) and the control group (-1.5 mm Hg). These results suggest that postural hypotension could play a role in the pathogenesis of LTG.

Aged↗

Tuberculous aortic insufficiency. Report of a case with successful surgical treatment.

A case of endocardial tuberculoma of the left atrium in a 20-year-old woman is presented. Ulceration of the tuberculoma at the aortic anulus led to disruption of the aortic valvular attachment and induced severe aortic insufficiency. Replacement of the aortic valve and administration of antituberculous medication permitted an uneventful recovery. This is probably the first case of tuberculous aortic insufficiency diagnosed in a living patient and surgically treated with the use of extracorporeal bypass.

Adult↗

[Diclofurime, a new major hypotensive agent. Clinical study in 24 patients (author's transl)].

Diclofurine is a new ketone-oxime derivative with potent peripheral vasodilating properties. Its hypotensive effects were studied in 24 patients suffering from severe hypertension resistant to combinations of most hypotensive drugs. In 22 patients who received diclofurime alone the blood pressure decreased from mean values of 194 +/- 1/118 +/- 3 to 166 +/- 4/97 +/- 3 mmHg after the weeks of treatment and remined at simular levels on further examinations. Most remarkably, the fall in BP was accompanied by a decrease of 15 beats/minute in supine heart rate. The mean daily dosage of diclofurime was 518 mg, the drug being taken in three divided doses. In 7 cases where diclofurime was combined with acebutolol either from the start or (in 5 cases) after an initial period of monotherapy, the efficacy of the treatment was enhanced by the beta-blocking agent. Out of 24 patients studied only one failed to respond. The new drug was generally well tolerated. Diclofurime appears to be one of the most active and best tolerated drugs for long-term oral treatment of arterial hypertension.

Acebutolol↗

Influence of carteolol and timolol on IOP an visual fields in glaucoma: a multi-center, double-masked, prospective study.

The influences of Carteolol and Timolol eye drops on intraocular pressure (IOP) and visual fields were compared in a multi-center, double-masked, prospective study. Two-hundred and forty eyes of 120 patients were initially included in the study, and 142 eyes of 72 patients fulfilled all the criteria for final statistical analysis. Both drugs significantly reduced IOP. The visual fields in both treatment groups did not change during one year of treatment. In both groups some patients improved slightly, and others deteriorated slightly. This indicates that locally applied beta-blockers may efficiently stop further progression of visual field defects in cases with increased IOP and early visual field damage. There was no difference between Carteolol and Timolol in this regard. The side effects were minimal, and there were no differences in their frequency or intensity in the two treatment groups.

Adolescent↗

[Facial dysmorphism related to valproic acid ingestion during pregnancy].

The authors report a case of cranio-facial changes in a neonate who had been exposed to Valproate. Clinical picture consisted of hypoplastic fronto-orbital edges and microstomia. These abnormalities are compared with the series reported in the literature.

Abnormalities, Drug-Induced↗

The antagonistic effects of ouabain and calcium channel blockers on the contractility of the isolated rat heart.

The simultaneous prescription of a calcium channel blocker and a cardiac glycoside is a frequently used therapeutic combination in cardiology, although its consequences on inotropism have not been really evaluated. This association is studied on isolated rat heart perfused at constant coronary pressure, paced at a constant frequency and working against a left intraventricular balloon. Since the inotropic effects are dependent on the basic level of myocardium contractility, controls were made hypocontractile by lowering external calcium level to 0.25 mM. For the same initial systolic pressure (45 mm Hg) and + dP/dTmax (150 mm Hg X s-1) the inotropic effect of 10(-5) M ouabain was significantly less pronounced in the presence of 10(-6) M verapamil or 10(-7) M nifedipine at 2.5 mM CaCl2 than at the low external calcium concentration of 0.25 mM (increasing the + dP/dtmax by 35% +/- 4, 29% +/- 6 and 110% +/- 18 respectively). Since we know that the inotropic properties of digitalis are probably due to an increase of the slow calcium inward current, we conclude that the observed effect would be due to a blockade of these channels by calcium blockers.

Animals↗