Rhône-Poulenc

About: Rhône-Poulenc is a based out in . It is known for research contribution in the topics: Alkyl & Catalysis. The organization has 8909 authors who have published 8934 publications receiving 182241 citations. The organization is also known as: Rhone-Poulenc.

Morphological and functional integrity of precision-cut rat liver slices in rotating organ culture and multiwell plate culture : Effects of oxygen tension

Abstract: We examined the maintenance of functional and morphological integrity of precision-cut rat liver slices cultured in various incubation systems and conditions for 72 h. Slices were incubated (37°C) for 6, 24, 48, and 72 h in supplemented Williams E medium in 6-well plastic culture plates on a gyratory shaking platform (WPCS) or in a rotating organ culture system (ROCS) using 5% CO2–95% air (WPCS/air or ROCS/air) or 5% CO2–70% O2–25% N2 (WPCS/ O2 or ROCS/ O2). Biochemical and functional parameters of slices maintained in WPCS/air or WPCS/ O2 were almost totally inhibited after 24 h, in keeping with the extensive and diffuse coalescing coagulative necrosis typical of post-ischemic injury affecting almost all the slice surface after 48 h. As compared to freshly isolated slices, slices maintained in ROCS/air for 72 h showed stable ATP and GSH content, increased protein synthesis, and a slight steady decrease in GST activity, while ATP and GST activity remained stable and protein synthesis and GSH content increased in slices incubated in ROCS/ O2 for 72 h. The extent of coagulative necrosis was markedly lower in longitudinal sections from slices incubated for 72 h in ROCS/ O2 than in ROCS/air. Transversal sections from slices kept in ROCS/air for 72 h showed a thick central band of necrotic cells edged by two peripheral layers of viable hepatocytes, whereas most of the slice was composed of viable hepatocytes lined by two thin layers of necrotic cells after 72 h in ROCS/ O2. ROCS/ O2 emerged as the system best preserving the histological and functional integrity of rat liver slices in long-term culture.

Amoeboid Microglial Cells and not Astrocytes Synthesize TNF‐α in Swiss Mouse Brain Cell Cultures

Abstract: The role of tumour necrosis factor (TNF-alpha) in brain physiology and pathology has been the focus of several studies. However, the source of this lymphokine in the central nervous system and the regulation of its synthesis is still poorly understood. We have therefore used purified astrocytes and brain macrophages in culture to compare the abilities of these two cell types to synthesize TNF-alpha and its mRNA. We find that, in the Swiss mouse, no significant TNF activity or TNF-alpha mRNA are produced by astrocytes, even following activation with lipopolysaccharides (LPS). On the other hand, purified microglial cells express a cytotoxic activity able to kill TNF-sensitive LM cells. Part of this activity is released into the culture medium and part remains bound to the membrane after mild paraformaldehyde treatment, demonstrating the existence in the culture of the soluble and membrane-bound forms of TNF activity. The fact that amoeboid microglial cells, and not astrocytes, are the actual source of TNF in brain cultures was further demonstrated by Northern blot analysis and in situ hybridization using a TNF-alpha specific oligonucleotide probe. The definition of the cell type which, in the CNS, is responsible for TNF synthesis will allow the regulation of this lymphokine to be analysed and opens the way for a better understanding of the interactions between amoeboid microglial cells and the other cell types which make up the nervous system.

Substituted bicyclic bis-aryl compounds exhibiting selective leukotriene b4 antagonist activity, their preparation and use in pharmaceutical compositions

Abstract: This invention relates to compounds having selective LTB4 antagonist properties and comprising an aryl or heteroaryl mono- or bicyclic ring which has at least two substituents attached thereto; (1) a substituted or unsubstituted aryl or heteroaryl mono- or bicyclic ring and (2) a substituent chain having a terminal carboxylic acid functional group or derivative thereof attached thereto. This invention further relates to processes for their preparation and therapeutic compositions comprising said compound and methods for the treatment of disorders involving LTB4 agonist-mediated activity utilizing said compositions wherein the compounds are described by general formula (I) and pharmaceutically acceptable salts thereof.