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Although the kidney represents a target for the accumulation and toxicity of arsenic, little is known about the molecular targets of arsenic in this organ. Therefore, these studies were designed to examine the molecular impact of arsenite [As(III)] and arsenate [As(V)] at low (nanomolar) concentrations. Precision-cut rabbit renal cortical slices were challenged with As(III) or As(V) for up to 8 h. Neither form of the metal induced overt cytotoxicity as assessed by intracellular K+ levels over this time period at concentrations from 0.01-10 microM. In addition, no alterations in the expression of Hsp 60, 70, or 90 were observed. However, induction of heme oxygenase-1 (Hsp 32) was seen following a 4-h challenge with As(III), but not with As(V). As(III) and As(V) induced DNA binding of AP-1 at 2- and 4-h exposure; following a 6-h exposure there was no difference. Although no alteration in the DNA binding activity of ATF-2 was induced by As(III) or As(V), both forms enhanced the DNA binding activity of Elk-1. Enhanced DNA binding activity of AP-1 and Elk-1 correlated with increased gene expression of c-fos, but not c-jun, at 2 h. c-myc gene expression was also induced by As(III) and As(V), albeit at a later time point (6 h). These results suggest that acute arsenic challenge, by either As(III) or As(V), is associated with discrete alterations in the activity of signaling pathways and gene expression in renal tissue.   相似文献   
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Examines the growing use of "work transformation" or process re-engineering techniques in health-care organizations. Identifies how pressures on funding and increased expectations are forcing health-care organizations to adopt radical solutions in their search for lower costs and improved quality of care. Also examines the experience of a number of organizations, and highlights some of the risks involved in taking these approaches.  相似文献   
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Women with recurrent abortion, primary unexplained infertility, and gestational trophoblastic neoplasia (GTN) manifest disordered human chorionic gonadotrophin (HCG) secretion. Mutations in the HCG beta/luteinizing hormone (LH) beta gene complex could cause aberrant HCG production in these disorders. The purpose of this study was to determine whether HCG beta gene deletions occur in women with recurrent abortion or primary unexplained infertility, and whether HCG beta gene duplications are present in women with GTN. DNA was extracted from 10 patients with unexplained recurrent abortion, 10 patients with unexplained primary infertility, 12 patients with GTN, three partners of women with GTN, and 30 controls. Southern blots were constructed and hybridized with DNA probes for HCG beta-5 and the LH beta gene. No gene deletions were identified in patients with recurrent abortion or primary unexplained infertility. Likewise, no gene duplications were identified in women with GTN. A previously described Mbol restriction fragment length polymorphism (RFLP) was identified in both patients and controls. A new Pstl RFLP was also characterized, but was present in patients and controls. Deletion/duplication mutations in the HCG beta/LH beta gene complex do not appear to be common causes of aberrant HCG production in humans with these disorders.   相似文献   
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Wolfram syndrome is an autosomal recessive disorder characterized by juvenile diabetes mellitus, diabetes insipidus, optic atrophy and a number of neurological symptoms including deafness, ataxia and peripheral neuropathy. Mitochondrial DNA deletions have been described in a few patients and a locus has been mapped to 4p16 by linkage analysis. Susceptibility to psychiatric illness is reported to be high in affected individuals and increased in heterozygous carriers in Wolfram syndrome families. We screened four candidate genes in a refined critical linkage interval covered by an unfinished genomic sequence of 600 kb. One of these genes, subsequently named wolframin, codes for a predicted transmembrane protein which was expressed in various tissues, including brain and pancreas, and carried loss-of- function mutations in both alleles in Wolfram syndrome patients.   相似文献   
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The growth of corporate orientation for healthcare structures, with a focus on bottom-line management, has radically altered the role of nurse executives. With the organization's emphasis on performance, productivity, and results, successful nurse executives are now integrating the management of the delivery of nursing care with the management of complex corporate structures and relationships. The editor of Executive Development discusses the rapidly changing expectations and demands of the contemporary nurse executive's work.  相似文献   
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