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Biomedical subjects

J Belleville

Publications and source records attributed to J Belleville.

At least 91 records · Page 5Linked to original sources
PubMed1981

Biological and mechanical behavior of autologous pericardium used for tricuspid valvular replacement in dogs.

The fate of autologous pericardium when used to replace a tricuspid valve leaflet has been investigated in dogs. Changes have been studied by means of macroscopic, mechanical, histological, scanning electron microscopy, and in vitro culture techniques. In each of nine experiments the valve failed and death occurred within the first 15 post-operative days. Retraction, thickening of the cusp, fibrinous deposition and/or tissue rupture were associated with a decrease of resistance to traction tests, decrease of elasticity and increase of viscosity of the implanted tissue. The early behavior of autologous pericardium was characterized by precocious inflammatory reaction on the valve leaflets, focal disruption of the collagenous structure of the leaflets, absence of fibroblastic cell infiltration as confirmed by in vitro culture of implanted pericardium and the lack of endothelial-like cell surface at the 10th-15th postoperative day.

Animals↗
PubMed1981

Behaviour of digestive enzymes in the pancreatic juice and pancreas of rats fed on a low-protein diet (3 p. 100 of cereal protein) then on a balanced diet (23.5 p. 100 of mixed protein).

The aim of this study in the rat was to determine the effect of a low-protein diet (3 p. 100 cereal protein) and balanced refeeding (23.5 p. 100 mixed protein) on the activity of some pancreatic digestive enzymes and the amount of their secretion. Parallel studies were carried out on the pancreas and its exocrine secretion. 1) With a low-protein diet (21 days), there was a decrease in the amounts of bile and pancreatic juice secreted. During balanced refeeding (18 days), the amount of bile secreted returned to normal and, although that of the juice increased, it was less than the amount secreted by the reference lot. 2) Body and pancreatic weights decreased slightly with the low-protein diet. The protein content and mitotic ability of the pancreas declined. However, during balanced refeeding, the ponderal weight of the pancreas returned to normal more rapidly than that of the overall organism. Pancreatic protein content and mitotic ability also augmented. 3) The low-protein diet produced an overall decrease in enzyme activity in the pancreas and in the juice. However, in the absence of any dietary stimulation, these activities were not affected proportionally in the same way as the pancreas and its exocrine secretion. Nevertheless, no disturbance in the digestion and absorption of the ration was observed. 4) During balanced refeeding, enzyme activities increased to different levels in the juice and the pancreas but after 18 days total enzyme activity had not been entirely recovered. 5) Enzyme activity varied widely, especially during the first 48 hrs of malnutrition and the first 36 hrs of refeeding.

Animals↗
PubMed1981

In vivo release of a heparin-like factor in dogs during profound hypothermia.

Experimentally induced hypothermia (20 degrees C) for 60 minutes in dogs provokes a significant decrease in the platelet count, which reverses during subsequent rewarming, and the constant release of a heparin-like factor, which reacts as a specific inhibitor of factor Xa. This phenomenon is also rapidly reversible, and heparin values are not significantly different from control levels after 90 minutes of rewarming. The mean maximal concentration of heparin-like material is 0.54 U/ml, or about double control levels. Its half-life is approximately 90 minutes. The level of circulating antithrombin III was not modified during hypothermia and rewarming.

Animals↗
PubMed1980

[Effect of a protein-deficient diet (5 p. 100 gluten) and of balanced refeeding (15 p. 100 casein) on potential lipase, colipase-dependent lipase and phospholipase A2 activities. I. In the growing rat pancreas].

The intake of a 5 p. 100 gluten diet as the only protein source caused an overall protein synthesis deficiency that immediately stopped the rat growth. At first, the pancreas was less affected than the rest of the organism, but after 29 days of malnutrition, there was a 40 p. 100 decrease in body and pancreatic weight. The protein level of the deficient pancreas remained at that of the controls. Refeeding caused a considerable but temporary increase in that level after 24 h. The specific enzyme activities (AS) showed high variations from one day to the other, but only phospholipase A2 AS was significantly affected by the deficiency (--50 p. 100). Total lipase activities of the pancreas were reduced by 50 p. 100 and those of phospholipase A2 by 70 p. 100. Refeeding caused a considerable increase in lipase activities in 12 h and in phospholipase A2 activity in 48 h, but this process was brief and did not indicate complete recovery of those activities. After 27 days of refeeding, only phospholipase A2 showed good levels. Adding methionine to the deficient diet only changed the colipase level; this constitutes one more argument in favor of a distinct synthesis for this factor and for lipase.

Animals↗
PubMed1980

[Effect of a protein-deficient diet (5 p. 100 gluten) and of balanced refeeding (15 p. 100 casein) on potential lipase, colipase-dependent lipase and phospholipase A2 activities. II. In the pancreatic juice of the growing rat].

We experimented with a diet resembling a protein-deficient one eaten by man, having a low protein level and proteins of poor biological value. Malnutrition caused weight loss accompanied by an overall reduction of ingesta. However, the food intake, as compared to animal weight, was the same in the undernourished animals as in the controls. Bile and pancreatic juice outputs were not altered continuously and regularly but with the poor protein diet, they were lower. Refeeding a balanced diet caused these outputs to increase. When 0.6 p. 100 of methionine was added to the deficient diet, no significant difference was noted in the outputs of the rats eating the deficient diets. Enzyme activities in the juice and pancreas varied widely from one day to another during malnutrition and during refeeding. The mean values of specific activities, which masked these variations, showed that malnutrition did not significantly decrease the phospholipase A2 activity in the pancreatic juice, while potential lipase and colipase-dependent lipase activities declined. Refeeding temporarily stimulated specific phospholipase A2 and potential lipase activities the third day; colipase-dependent lipase activity was not activated. After 2 to 3 weeks of refeeding, the specific activities of the three enzymes were similar to the control values, but were no longer so at the end of refeeding. This would suggest a return to the normal, as shown by the oscillations around the control values. Protein malnutrition, as refeeding, did not in general cause the same changes in all the enzymes at the same time.

Animals↗
PubMed1978

[Adaptation of lipase and phospholipase A activities in pancreas and pancreatic juice in rats with diets rich in triglycerides and phospholipids].

Lipid rich diets containing about 20% of triglycerides or phospholipids given to Rats during 2 months were observed to increase lipase and phospholipase A2 activities in pancrease and pancreatic juice. The phospholipase and lipase activities are higher, respectively, on the phospholipid and triglyceride diet. Lower effects are observed after a 7-day administration of diet containing 40% of total lipid.

Animals↗
PubMed1978

[Effects of diets rich in triglycerides and phospholipids on lipase and phospholipase A activities in rat pancreatic juice and pancreas].

Lipase and phospholipase A activities were increased in the pancreas and pancreatic juice of rats ingesting during two months 20% phospholipids- or triglycerides-rich diets. The activity of lipase is higher with the triglycerides-rich diet and the phospholipase A activity is higher with the phospholipids-rich diet. After seven days of the experiment, these two enzymes activities were less increased with diet containing 40% lipids.

Animals↗
PubMed1978

Mechanism of glycoconjugates biosynthesis in the vascular wall with external circular constraint.

Extrinsic local constraints, realised on dogs aorta are responsible for parietal lesions in the form of thickening of the arterial wall. Histological changes in the intima and media are characteristic of processes of degeneration destruction and cellular regeneration, superposed on sub-endothelial proliferation accompained by partial or total destruction of endothelial cells in the intimal layer. In addition to histological changes, there were perturbation in enzymatic activities of glycosyltransferases responsible for macromolecular constructions in the intima. Microsomic enzymes studied were: N-acetyl-glucosaminyl-transferase, sialyl-transferase and N-acetyl-galactosaminyl-transferase, and two glycosyl-transferases located in the soluble cytoplasmic phase: fucosyl and xylosyl-transferase. The changes observed were different according to the position of the sugars in the glycoprotein chains. For example the variation of fucosyl-transferase activity is significant: it disappears in group where the sialyl-transferase activity is enhanced. The transfer of xylose is decreased. Finally, changes observed in hexosaminyl-transferase activities were parallel.

Animals↗
PubMed1978

[Effects of isoproteic and lipid rich diets on lipase, phospholipase A2, cholesterolesterase, trypsin and amylase activities in rat pancreatic juice and pancreas (author's transl)].

Isoproteic and lipid-rich diets containing about 15 or 20 % of sun flower triglyceride or soya phospholipids given to rats for 8 weeks were observed to increase lipase, phospholipase A2 and trypsin synthesis in the pancreas phospholipase A2 and trypsin synthesis in the pancreas and the activities of these enzymes in the pancreatic juice (Tables IV, V). Smaller effects are observed after 15 day administration of diets containing 40 % of triglycerids or phospholipids ; these diets decreased the ADN content of pancreas.

Amylases↗
PubMed1977

[Coagulation deficits and hemorrhagic consequences after cardiac surgery under ECC].

I--A statistical study of the results of tests of hemostasis was carried out in patients who had undergone major cardiac surgery with extra-corporeal circulation. There were two series of patients (1.504 and 547 operated) suffering mainly from congenital cardiopathies, valvulopathies or coronaritis. Bearing in mind the hematocrit and the total protein level, the following was studied before and after ECC and 24 hours after the intervation: the blood platelet level, fibrinogen, prothrombin and its cofactors, antithemophilic factors A and B, FDP amd fibrinolytic activity. The fall in platelet stickiness is specifically pointed out, and also the fall in the level of fibrin stablizing factor (factor XIII) which is met with after ECC, and which can explain the persistence of certain hemorrhagies. Furthermore, the fall in antithrombin III level then its rise can contribute to the "heparine rebound" occurring in certain cases after neutralization of heparinemia with protamine. II--The deficits in the quantitatively and qualitatively variable hemostatic factors do not necessarily lead to hemorrhage. Hemorrhage, due to biological causes, are met with in 5 to 6 p. 100 of the cases. Most of the time they are provoked by a residual hemorrhage or a "heparine rebound", deficits in coagulation factors, a DIVC syndrome, difficult to diagnose and to treat, or fibrinolysis, much more rarely nowadays, owing to the almost routine use of antiproteases. Sometimes, the check up of coagulation can be barely disturbed and local abnormalities in biological hemostasis which are still not well understood, are invoked in order to explain the hemorrhage.

Blood Cell Count↗