996 resultados para Baumeister, Roy F
Resumo:
Chlorhexidine (CHX), widely used as antiseptic and therapeutic agent in medicine and dentistry, has a toxic effect both in vivo and in vitro. The intrinsic mechanism underlying CHX-induced cytotoxicity in eukaryotic cells is, however, still unknown. A recent study from our laboratory has suggested that CHX may induce death in cultured L929 fibroblasts via endoplasmic reticulum (ER) stress. This hypothesis was further tested by means of light and electron microscopy, quantification of apoptosis and necrosis by flow cytometry, fluorescence visualization of the cytoskeleton and endoplasmic reticulum, and evaluation of the expression of 78-kDa glucose-regulated protein 78 (Grp78), a marker of activation of the unfolded protein response (UPR) in cultured L929 fibroblasts. Our finding showing increased Grp 78 expression in CHX-treated cells and the results of flow cytometry, cytoskeleton and endoplasmic reticulum fluorescence visualization, and scanning and transmission electron microscopy allowed us to suggest that CHX elicits accumulation of proteins in the endoplasmic reticulum, which causes ER overload, resulting in ER stress and cell death either by necrosis or apoptosis. It must be pointed out, however, that this does not necessarily mean that ER stress is the only way that CHX kills L929 fibroblasts, but rather that ER stress is an important target or indicator of cell death induced by this drug. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
Reports on results of a survey, completed in 2000, of wives in three villages in the Phulbani district, Orissa, India. These villages are dominated by the Kondh scheduled tribe but some also contain members of the scheduled caste, called Dombs in Orissa. The article reports on the total responses and comparative responses of these groups to a structured questionnaire. The article provides background information for the villages surveyed, and reports information in relation to wives and their families about property rights, assets and incomes, economic conditions and survival strategies, aspects of credit, production and marketing, social dynamics and eduction. In addition, children’s affairs, including the treatment and entitlements of female and male children, are considered as well as additional aspects of the socioeconomic status of wives.
Resumo:
Economic theories of the family and gender discrimination within the family are examined in the context of Kondh dominated tribal villages in rural western Orissa, India, drawing on results from a survey of 106 wives. The survey involved direct interviews using a structured questionnaire. This article examines the relevance of economic unitary and bargaining theories of the family in this social context, drawing on background literature. Using the survey results, socioeconomic influences on the status of wives within their families are analyzed and the entitlements of female and male children are compared and analyzed. Because of cultural embedding, it is suggested that the relevance of economic theories of the family depend significantly on cultural context. In many cases, it seems that poverty has a negative influence on the social empowerment of females but it is not the only influence nor always a sufficient condition for discrimination against females.
Resumo:
The objective of this study was to evaluate the effect of the ion exchange treatment on the R-curve behavior of a leucite-reinforced dental porcelain, testing the hypothesis that the ion exchange is able to improve the R-curve behavior of the porcelain studied. Porcelain disks were sintered, finely polished, and submitted to an ion exchange treatment with a KNO(3) paste. The R-curve behavior was assessed by fracturing the specimens in a biaxial flexure design after making Vickers indentations in the center of the polished surface with loads of 1.8, 3.1, 4.9, 9.8, 31.4, and 49.0 N. The results showed that the ion exchange process resulted in significant improvements in terms of fracture toughness and flexural strength as compared to the untreated material. Nevertheless, the rising R-curve behavior previously observed in the control group disappeared after the ion exchange treatment, i.e., fracture toughness did not increase with the increase in crack size for the treated group.
Resumo:
Until recently, West Nile (WN) and Kunjin (KUN) viruses were classified as distinct types in the Flavivirus genus. However, genetic and antigenic studies on isolates of these two viruses indicate that the relationship between them is more complex. To better define this relationship, we performed sequence analyses on 32 isolates of KUN virus and 28 isolates of WN virus from different geographic areas, including a WN isolate from the recent outbreak in New York. Sequence comparisons showed that the KUN virus isolates from Australia were tightly grouped but that the WN virus isolates exhibited substantial divergence and could be differentiated into four district groups. KUN virus isolates from Australia were antigenically homologous and distinct from the WN isolates and a Malaysian KUN virus. Our results suggest that KUN and WN viruses comprise a group of closely related viruses that can be differentiated into subgroups on the basis of genetic and antigenic analyses.