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.

The pharmacology of ebselen.

Abstract: Ebselen has been demonstrated to be an effective anti-inflammatory agent in a variety of experimental modelsin vivo which differ from classical tests in that the aetiological roles of hydroperoxides and/or lipoxygenase products appear to be greater. Indeed, ebselen exhibits only weak anti-inflammatory activity in the traditional prostaglandin-dominated models, such as carrageenan paw oedema, adjuvant arthritis and yeast paw hyperalgesia [50]. The major targets of this anti-inflammatory activity appear to be plasma exudation and infiltration, possibly as a result of the inhibition of the hydroperoxide and/or leukotriene effects on leukocyte-endothelium interactions. Both reactive oxygen species [24] and LTB4 [51, 52] enhance granulocyte adhesiveness to endothelium and ebselen inhibits the generation of reactive oxygen species, catalyses the breakdown of hydroperoxides, inactivates LTB4 by isomerization and inhibits 5-lipoxygenase [9–11, 13–16, 27–29]. Consequently, any or all of these mechanisms of action, together with inhibition of hypoxic-reperfusion injury [53], could contribute to the anti-inflammatory activity of ebselen.

Process for the treatment of cellulose

Abstract: The process for the treatment of cellulose for activation for subsequent chemical reactions by bringing the cellulose in contact with liquid ammonia at a pressure higher than atmospheric pressure in a pressure vessel and subsequent expansion by rapid reduction of the pressure to atmospheric pressure, is carried out by using a cellulose pulp of an alpha-cellulose content of at least 92 mass %, letting the ammonia act on the pulp at room temperature or at a temperature higher than room temperature, after the expansion, removing the ammonia then still remaining in the pressure vessel except for a minimum content at which the state of activation reached by the action of the ammonia is still maintained and finally replacing the residual ammonia still needed to maintain the state of activation by another swelling or inclusion agent. The process is suitable, also on a large industrial scale, especially for the activation of pulp subsequently to be acetylated and makes possible to achieve a homogenous and high-grade activation. Further, no costly cooling apparatus is needed.

The significance of mouse liver tumor formation for carcinogenic risk assessment: results and conclusions from a survey of ten years of testing by the agrochemical industry.

Abstract: A survey was performed on the results of 138 carcinogenicity studies conducted in various mouse strains by the agrochemical industry over the period 1983-1993. Data for liver tumor incidence, liver weight, and histopathology were collected along with data on genotoxicity. Studies were judged positive or negative for liver tumor formation on the basis of apparent dose response, malignancy, and difference from historical control values using a weight of evidence approach. Thirty-seven studies were judged to be positive for liver tumorigenicity in one or both sexes. There was no evidence showing an influence of the mouse strain and the duration of the study on the proportion of positive studies. Although 8 of the chemicals tested in the 138 studies were positive in the Ames test, only one of these was judged positive for carcinogenicity. Only 6 of the 37 positive chemicals had any other reported positive genotoxicity findings. A clear relationship between hepatomegaly at 1 year after exposure and a positive tumorigenic outcome at 18 months or 2 years after exposure was demonstrated. Whereas the average relative liver weight of top dose animals was 110% of control in negative studies, it was 150% in positive studies. Likewise, very few negative studies demonstrated significant pathological findings after 1 year, whereas the majority of positive studies had significant liver pathology. The implications of these findings for extrapolation to humans are discussed.