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D Barres

Publications and source records attributed to D Barres.

26 records · Page 2Linked to original sources
PubMed1980

[Cortisone-induced osteonecrosis: knowledge acquired from observations in man and comparison with the results of animal experimentation].

Aseptic osteonecrosis is observed in 25% of cases after renal transplantation. This etiological variety of osteonecrosis is unusual in that it is frequently bilateral and has multiple localisations. Apart from the classical radiological signs, attention in attracted by isolated images of osteocondensation in the metaphyses and/or the diaphyses suggesting massive bony infarction and the appearances of fatigue fractures observed frequently (14%). In 43% of cases, the obvious necrosis was proceeded by early bone pain, around the 7 th day, during massive administration of corticosteroids in the prevention or cure of graft resection. This finding suggested to us that the best time to observe ischemia of the bone or marrow is very early and led us to undertake an experimental study in the rabbit. Two series of New Zealand White rabbits were treated with massive doses of corticosteroid and sacrificed between the 3rd and the 21st day. The treated animals presented an early peak of hyperlipemia from the 7th day onwards, and diffuse lesions of hepatic and renal steatosis. Fat emboli associated with appearances of parietal thrombosis were observed in most cases. In the same animals, there were also appearances of stage I or stage II necrosis. Referring to the description of bone marrow necrosis in stages by Arlet and Ficat, there was observed in all the series, a frequency of marrow lesions of all stages much higher in treated animals (16 out of 20) than in controls. Only one lesion of stage I was observed in controls; the difference was highly significant. (0,000001 < p < 0,00001). If one only considers necroses of stage II and III (10/20 in the treated group nil in controls) the frequency was still significant p < 0.001. The preliminary results of the fixation of tetracycline are reported.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Morphometric analysis of collagen network and plasma perfused capillary bed in the myocardium of rats during evolution of cardiac hypertrophy.

In order to investigate the consequences of different types of cardiac hypertrophy on myocardial capillary and fibrosis density in rats we describe here, in the same hearts, the pattern of capillary bed density visualized by fluorescein isothiocyanate dextran (FITC-dextran) and the pattern of fibrosis density as determined by automated image analysis. Pressure overload was induced by clipping one renal artery in rats (one-clip, two-kidney Goldblatt hypertension, RHV). Volume overload was induced by creation of an arteriovenous shunt between the abdominal aorta and the vena cava (aorto-caval fistula model ACF). Animals were sacrified at 1, 3 and 6 months following surgical procedure. Immediately prior to sacrifice, FITC-dextran (MW 150,000) was injected with the animal under ether anesthesia. Five minutes later, cardiac diastolic arrest was induced by the i.v. injection of potassium chloride. The heart was rapidly excised and placed in a formaldehyde solution. The degree of cardiac hypertrophy was calculated after measurement of cardiac weight. Left ventricular wall thickness and cavity area were measured by microscopic methods. Capillary density and geometry were determined by morphometric methods, under ultraviolet light microscopy, using a graphic tablet connected to a microcomputer. The degree of myocardial fibrosis, visualized with Sirius Red, was estimated by the use of automated image analysis using light microscopy. In renovascular hypertension, cardiac hypertrophy was maximum at one month (36%) and persisted through the six months of the study. This increase in cardiac mass was concentric, due to a significant increase in ventricular wall thickness and was associated with a marked increase in fibrosis and a significant decrease in subendocardial capillary density. These effects existed already one month and did not change with time. In the aorto-caval fistula model, cardiac hypertrophy was also maximum at one month (+56%), but this eccentric increase in cardiac mass was associated with no significant change in left ventricular wall thickness, but rather with a significant increase in the surface area of the left ventricular cavity. This volume overload hypertrophy was associated with a decrease in subendocardial capillary density which was negatively correlated with time. In contrast to concentric hypertrophy there was no increase in the fibrosis density compared to the sham-operated groups. Despite the identical degrees of hypertrophy, pressure and volume cardiac overload differed in a significant manner in both left ventricular wall thickness and cavity surface area.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗