[Risk factors associated with gastroduodenal lesions in a Douala referral hospital (Cameroon)]. / Facteurs de risques associés aux lésions gastroduodénales dans un hôpital de référence à Douala (Cameroun).

INTRODUCTION: The causes of gastroduodenal lesions are multifactorial, and few studies have assessed the impact of each of these factors in Africa. The aim of this study was to identify factors associated with the occurrence of gastroduodenal lesions in Cameroon. METHOD: This prospective, analytical study took place over a 5-month period in the endoscopy unit of the Douala General Hospital. Lifestyle, medical history, demographic, and clinical variables were collected. Infection with Helicobacter pylori was determined with a rapid urease (CLO) test. Multivariate regression was used to determine risk factors. RESULTS: The study included 234 of 265 patients seen in the department over the study period. Gastroscopy was normal for 54.2% of the subjects. The prevalence of peptic ulcers was 17.1% and of inflammatory lesions 26.4%. Risk factors associated with a gastroduodenal lesion were: age greater than 60 years [OR age = 2.953; 95% CI: 1.399 to 6.231; p = 0.004], H. pylori infection [OR = 2.953; 95% CI: 1.399 to 6.231; p = 0.003] and regular NSAID use [OR = 0.912; 95% CI: 0.112 to 2.733; p = 0.044] either a month before the examination or over the long term. CONCLUSION: Age greater than 60 years, NSAID consumption, and H. pylori infection are associated with the occurrence of gastroduodenal lesions.

Regulation of differentiation and protein kinase C expression in 3T3 T proadipocytes: effects of TGF-beta and transformation.

We are studying the mechanisms that regulate proliferation and differentiation of normal 3T3 T proadipocytes and neoplastically transformed clones which have lost the ability to differentiate. The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) and transforming growth factor beta (TGF-beta) are known inhibitors of the same step of the differentiation process in 3T3 T cells. Here, we examined the expression of the phorbol ester receptor/protein kinase C (PKC) during adipocytic differentiation of 3T3 T cells and its modulation by the differentiation inhibitor TGF-beta. PKC receptor assays were performed using a tritiated analogue of TPA and it was found that PKC receptor levels decreased approximately threefold during differentiation. Northern blot analyses revealed an even greater decrease of PKC transcripts during differentiation. TGF-beta inhibited not only differentiation, but the differentiation-dependent decrease in PKC levels as well. Transformed 3T3 T cells which have lost the ability to differentiate were found to express aberrant levels of PKC. The data suggest that TGF-beta may inhibit differentiation via a PKC-dependent pathway and that disruption of normal PKC levels or its regulation may be involved in the loss of differentiation control in transformed 3T3 T cells.

Kupffer cell sarcoma in rats after exposure to small doses of dimethylnitrosamine and N-2-acetylaminofluorene during hepatic regeneration.

During experiments to study the evolution of hepatocellular carcinoma in adult male Wistar rats by exposing regenerating livers to the action of small doses of dimethylnitrosamine (DMN) or N-2-acetylaminofluorene (AAF), several primary sarcomas of the liver were incidentally observed. The morphology and behavior of the tumors suggest their origin from Kupffer's cells. Kupffer cell sarcomas occurred more frequently when 70% hepatectomy was used as the regenerative stimulus. None of the 36 animals treated with AAF alone and 2 of the 38 rats given DMN only had this tumor.