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Biomedical subjects

A Aubert

Publications and source records attributed to A Aubert.

At least 109 records · Page 6Linked to original sources
PubMed1989

Effect of phenazine methosulfate on electrophysiological activity of the semicircular canal: antioxidant properties of trimetazidine.

Ischemia strokes appear to be the main source of cochleo-vestibular dysfunctions of peripheral origin. The present study aimed to investigate the action of oxygen free radicals on the bioelectric activity of the labyrinthine epithelium, using the frog semicircular canal as an in vitro preparation. We also examined the possible effect of the antianginal drug, trimetazidine (TMZ), under physiological conditions and during the administration of phenazine methosulfate (PMS). The model allows the ionic composition of endolymphatic and perilymphatic fluids bathing the semicircular canal to be dealt with separately. Spontaneous afferent vestibular nerve activity and the endolymphatic potential were recorded under resting conditions. Three additional parameters were investigated during mechanical displacement of the endolymphatic fluid: the ampullar direct current, the nerve direct current and the frequency of the evoked afferent spikes. Addition of TMZ (10(-6) and 10(-5) M, 50 min) into the perilymphatic compartment did not induce significant modifications of the different bioelectrical signals. Generation of oxygen free radicals, through administration of PMS (10(-5) M, 15 min) into the perilymphatic compartment, caused an impairment of all bioelectrical signals, except the ampullar direct current. The spontaneous activity, nerve direct current and frequency of afferent evoked spikes signals were significantly reduced 75 min after the start of PMS administration (-64, -17 and -32%, respectively). In contrast, there was a marked increase of the endolymphatic potential signal (+51%). Addition of TMZ (10(-6) or 10(-5) M) into the perilymph solution reversed the effect of PMS on all bioelectrical signals. These results indicate that TMZ acts as an antioxidant molecule which is capable of protecting the labyrinthine epithelium from the deleterious effect of oxygen radicals. Our data suggest that the protective effect of TMZ on ischemia-induced cochleo-vestibular dysfunctions may be accounted for by the antioxidant properties of this antianginal drug.

Animals↗
PubMed1989

Apolipoprotein AI is a serum and tissue marker of liver fibrosis in alcoholic patients.

The aim of this study was to assess the specific correlation of apolipoprotein-AI to hepatic fibrosis in alcoholic patients. Four hundred eighty two patients were prospectively included with serum measurement of apolipoprotein-AI within 10 days before liver biopsy. Pathologic features were semiquantitatively assessed by two observers. In 28 patients liver biopsy was used for histomorphometric assessment of fibrosis and immunohistochemical labeling of apolipoprotein-AI. Serum apolipoprotein-AI was negatively correlated to semiquantitative score of fibrosis (r = -0.50; p less than 0.001), independently of the scores of steatosis and alcoholic hepatitis (r = -0.44; p less than 0.001) and of the value of serum albumin, bilirubin, and prothrombin time (r = -0.22; p less than 0.001) and independently of the nutritional parameters (r = -0.29; p less than 0.009). The mean value of apolipoprotein-AI decreased according to the grade of fibrosis from 220 +/- 6 mg/dl (mean +/- SEM) to 110 +/- 8 mg/dl. Serum apolipoprotein-AI was negatively correlated to the percentage of fibrosis (r = -0.70; p less than 0.001) in the biopsies morphometrically assessed. The labeling was superimposed to the extracellular matrix. In conclusion, this study shows that decrease of apolipoprotein-AI is a serum and tissue marker of liver fibrosis independently of steatosis, alcoholic hepatitis, liver function tests, and nutritional parameters.

Apolipoprotein A-I↗
PubMed1989

[Colonoscopic surveillance of patients operated on in colorectal cancer. Retrospective evaluation of 269 tests in 125 patients].

The ideal frequency of endoscopic surveillance of patients operated on for colorectal cancer is not known. We report our experience of colonoscopic follow up of 125 patients after excision of a colorectal cancer. The median interval between resection and the first check colonoscopy was 12 months. The median duration of follow-up was 28 months (range: 3 months to 10 years). 269 colonoscopies allowed diagnosis of 8 anastomotic recurrences within a median delay of 21 months after surgery (range: 3 months to 5 years). In 6 of these patients, the recurrence was clinically suspected. In 2 patients, it was asymptomatic and was discovered on systematic colonoscopy. Potentially curative surgery was only possible in 1 case. Follow up colonoscopies also allowed excision of 113 adenomatous polyps in 39 patients and the discovery of 4 new invasive cancers within a median delay of 7.4 years after excision of the first cancer. Due to the disappointing value of colonoscopy in the detection of anastomotic recurrences and the propensity of the remaining colon to develop new polyps, in the absence of a comparative trial, we arbitrarily adopted a follow up rhythm based on early post-operative colonoscopy (3 months post-surgery) and then yearly for the first 2 years. Further follow-up was similar to that adopted for patients with a past history of endoscopic polypectomy.

Aged↗
PubMed1988

[Sclerotherapy of esophageal varices using ethanol in combination with propranolol: clinical study of 30 patients].

A prospective study was conducted in 30 patients to assess the efficacy and safety of endoscopic sclerotherapy with absolute alcohol associated with propranolol for prevention of recurrent variceal bleeding. Patients were included if propranolol alone had failed or if they had at least three factors which increased the risk of rebleeding although the patients were receiving propranolol; two patients were treated by sclerotherapy only because of contraindications to propranolol. Etiology of portal hypertension was cirrhosis in 29 patients and portal vein thrombosis in one patient. Seventeen patients were grade A and 13 were grade B according to Child-Pugh's classification. The cumulative percentage of patients free of rebleeding 12 months after inclusion was 43 +/- 10 p. 100 (m +/- SD). The cause of recurrent bleeding was esophageal varices in nine patients and esophageal ulcers in five patients. The cumulative percentage of variceal rebleeding 12 months after inclusion was 61 +/- 10 p. 100. The cumulative percentages of patients free of rebleeding from varices were not significantly different between the Pugh A (64 +/- 14 p. 100) and Pugh B (56 +/- 15 p. 100) patients. The cumulative percentage of patients surviving 12 months after inclusion was 55 +/- 9 p. 100. The cause of death was not related to sclerotherapy in 11 patients. Two patients died of esophageal wall necrosis associated with mediastinitis. These two patients had received large volumes of sclerosing agent because of important bleeding during the last injection. Our results suggest that in patients without severe cirrhosis who cannot be treated by propranolol alone, the risk of rebleeding and the risk of death are high despite sclerotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Cross sectional echocardiographic assessment of great artery diameters in infants and children.

The pulmonary trunk and aortic root were measured on cross sectional echocardiograms in 173 normal subjects aged from one day to 15 years. Fifteen neonates were reexamined 3-6 days later. The great vessels were visualised in the parasternal long axis and short axis views. All measurements were made in end diastole and end systole by the leading edge method. The internal diameter (inner surface to inner surface) of the pulmonary trunk was also measured. The diameters of the great vessels correlated best with the square root of body surface area. Individual variability in cardiac growth gave a wide scatter of normal values. This was controlled for by calculating the ratio of the pulmonary trunk to aortic root for each subject. This ratio showed little individual variability and, except for the neonatal period, was remarkably constant throughout infancy and childhood (1.06 (0.06)). In the first 24 hours of life the ratio of the pulmonary trunk to the aortic root was significantly larger (1.29 (0.12)) but within one week it decreased to the "normal" ratio found in the older age groups. These normal data should be useful in assessing patients with congenital heart disease, particularly those in whom pulmonary blood flow is abnormal.

Adolescent↗
PubMed1985

Measurement of pacing threshold.

Thresholds in constant current and constant voltage are reported for 405 CPI 4118 (Cardiac Pacemakers, Inc.) tined leads. In 98% of the cases, the constant current threshold was equal to or lower than 0.6 mA. A constant voltage threshold was equal to or lower than 0.5 V in 96% of the cases. Three external pacemakers and two pacing system analyzers were evaluated as threshold testing devices. For analyzing the waveforms of current and voltage stimuli, a calibrated isolation amplifier was used. We could not find a definite difference between the value, at which pacing is lost with reduction of the pulse generator output, and the value at which increase reestablishes pacing.

Pacemaker, Artificial↗
PubMed1984

Cardiac structure and function in cyclists and runners. Comparative echocardiographic study.

Twelve cyclists and 12 long distance runners matched for age, height, and weight with two control groups of 12 non-athletes were studied echocardiographically to evaluate cardiac structure and function. Runners weighed 8 kg less than cyclists, but age and height were similar. Peak oxygen uptake per kg body weight was higher in athletes than in the control subjects but was similar in the cyclists and in the runners. The athletes' hearts had a larger end diastolic left ventricular internal diameter, mean wall thickness, and cross sectional area of the left ventricular wall than those of the respective control subjects. Nevertheless, whereas the left ventricular internal diameter was not different between the cyclists and runners, mean wall thickness and cross sectional area of the left ventricular wall were greater in the cyclists even after adjustment for weight. The ratio of wall thickness to left ventricular internal radius was significantly larger in cyclists than in their control group, but the ratio was similar in runners and their control group. The echocardiographic indices of left ventricular function were similar in the athletes and the control groups. Systolic left ventricular meridional wall stress was lower in the cyclists than in the runners. The data suggest that runners develop an increase in left ventricular wall thickness which is proportionate to the internal diameter but that in cyclists the increase is disproportionate because of the isometric work of the upper part of the body during cycling.

Adolescent↗
PubMed1970

Prophylactic treatment of angina pectoris. A double-blind cross-over comparison of alprenolol and pentanitrol.

Twenty-one patients with angina pectoris took part in a double-blind cross-over comparison of alprenolol (an adrenergic beta-blocker), pentanitrol (pentaerythritol tetranitrate), and placebo. Two-thirds of the patients were clinically improved on alprenolol 100 mg. four times daily, which was found to be significantly better than pentanitrol 30 mg. four times daily and placebo. There was also an indication of reduced severity of anginal attacks during alprenolol therapy. It is concluded that success in at least two-thirds can be expected with alprenolol. No serious complications or side-effects occurred during alprenolol treatment.

Adrenergic beta-Antagonists↗