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Biomedical subjects

A Dumont

Publications and source records attributed to A Dumont.

At least 73 records · Page 4Linked to original sources

Effect of chronic ethanol administration on bromobenzene liver toxicity in the rat.

Female Sprague-Dawley rats were pair-fed a nutritionally adequate liquid diet containing either ethanol or isocaloric carbohydrate for 3 weeks. In vitro studies showed that chronic ethanol pretreatment preferentially increased the liver microsomal biotransformation of bromobenzene to p-bromophenol (via the toxic 3,4-epoxide) rather than to o-bromophenol (via the nontoxic 2,3-epoxide) and could thus potentiate bromobenzene hepatotoxicity. Bromobenzene administration (500 mg/kg body weight, ip), after an overnight fast, was associated in ethanol-pretreated rats with greater and accelerated liver glutathione depletion and subsequent decrease in liver cytochrome P-450 content than in controls. As assessed histologically and by determination of the rise in activities of serum enzyme markers of liver necrosis, chronic ethanol pretreatment, however, mainly resulted in earlier onset and resolution of bromobenzene-induced liver necrosis, with only a mild increase in the maximal severity of liver lesions. These results suggest that the twofold increase in liver microsomal bromobenzene 3,4-epoxidation by ethanol, being much less than that seen after phenobarbital pretreatment in our animal model and in that of others, is apparently not sufficient to markedly affect the severity of bromobenzene-induced liver toxicity.

Alanine Transaminase↗

Endoscopic discovery and capture of Necator americanus in the stomach.

We report a case of the endoscopic discovery and removal of a specimen of Necator americanus hooked into the gastric mucosa of a black woman from Zaire. We extracted the parasite by means of biopsy forceps. Signs of previous bites were seen in the antrum. This exceptional localization might be due to a jejuno-duodeno-gastric reflux.

Adult↗

[Granulocytic sarcoma of the mediastinum].

The occurrence of a granulocytic sarcoma before any signs of leukemia is unusual and may pose confusing diagnostic problems. This report deals with such a case who presented with a mediastinal thymic tumor and superior vena cava syndrome. The authors emphasize the localization and the histological techniques that are utilized to ascertain the diagnosis.

Adult↗

Quantitative and ultrastructural changes of peritoneal macrophages in immunized rats after intraperitoneal injection of Novikoff hepatoma.

The response of peritoneal cells to transplantable Novikoff hepatoma was studied in immunized and nonimmunized inbred male SD rats to elucidate the role of macrophages in syngeneic tumor rejection. Specific immunization was induced by double sc challenge with viable tumor cells. Peritoneal cells were harvested by lavage at intervals of 6 hours and 1, 2, 3, 4, and 9 days after ip tumor injection. Some of the lavage fluid was used to determine the total number of cells, and the remainder was prepared for ultrastructural study. Different counts were made at the electron microscope level, and the ultrastructures of macrophages and tumor cells were studied. The results indicated that during the early intervals after tumor injection, the numbers of macrophages and lymphocytes were significantly increased in immunized animals. The mononuclear cells accumulated more slowly in the peritoneal cavities of nonimmunized rats. Morphologic heterogeneity was observed in the macrophage population of immunized rats up to day 4. Concurrent with these changes in macrophages were the decreased mitotic activity and ultrastructural alterations in tumor cells followed by their complete disappearance. In nonimmunized animals tumor cells proliferated actively and by day 9 constituted 85% of the peritoneal population.

Animals↗

Colorectal neoplasm: a rare complication of ureterosigmoidostomy.

A 24-year-old woman had a rectal neoplasm which occurred 20 years after she had undergone ureterosigmoidostomy for exstrophy of the bladder. Only 41 cases of bening or malignant tumours of the large bowel developing after ureterosigmoidostomy have previously been reported in the literature. Adenocarcinoma of the colon is most frequently found and can develop even after urine has been diverted away from the colon. The presenting symptoms are either those of ureteral obstruction or of colorectal neoplasm. This rare complication remains intriguing and the possible pathogenetic mechanisms are discussed.

Adult↗

[Malignant syndrome caused by neuroleptics (3 observations)].

This study concerns 3 cases of malignant syndrome due to neuroleptics. Our aim is to clarify the nature of this syndrome and to attempt to delimit it from malignant hyperthermia. The etiology suggests that its occurence should increase with the growing use of very active neuroleptics. It consists clinically of an extrapyramidal syndrome with hypertonicity, akinesia, tremor and with a neuro-vegetative syndrome of which the main sign is hyperthermia. On the basis of physiopathology it is attempted to explain, in the light of fresh data, the extrapyramidal signs, the hyperthermia and the rise in the OPK Etiological treatment has, however, proved disappointing.

Adult↗