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21.
This paper deals with the behavioral pattern of neighbor relations and their relationships to the subjective attitudes and expectations of the residents. The sample was 318 middle-class women living in eight-to 20-story buildings. The findings indicate that respondents so desiring were able to develop active social ties with their neighbors. Moreover, they interacted with neighbors despite the fact that the majority had opportunities for alternative social relations. The distinction between localized and nonlocalized high-rise residents does not seem meaningful in this case. Actual social ties with neighbors were related to norms and expectations regarding neighbor relations. Despite active neighboring, respondents did not have difficulties obtaining privacy. 相似文献
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Methamphetamine (METH) is a neurotoxic drug of abuse that can cause terminal degeneration. Our laboratory recently showed that METH can also cause widespread apoptosis in the rodent brain. Current concepts of the molecular neurotoxicity of this illicit substance have earlier suggested the participation of reactive oxygen species, inflammatory processes and immediate early genes. Recent cDNA studies in our laboratory have hinted to the possibility that METH-induced neurodegeneration might also include the participation of cell death might also include the participation of cell death genes such as BAX and BCL-2. Activation of multiple caspases appears to also occur during METH-induced neurodegeneration. Furthermore, DNA repair pathways seem to also be involved in attempts to protect against METH-induced DNA damage. These results will be discussed in terms of the possible involvement of multiple transduction mechanisms in the appearance of METH neurotoxicity. 相似文献
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The TON_0887 gene was identified as the missing histidinol-phosphate phosphatase (HolPase) in the hyperthermophilic archaeon "Thermococcus onnurineus" NA1. The protein contained conserved motifs of the DDDD superfamily of phosphohydrolase, and the recombinantly expressed protein exhibited strong HolPase activity. In this study, we functionally assessed for the first time the monofunctional DDDD-type HolPase, which is organized in the gene cluster. 相似文献
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The Amyloid-β (Aβ) peptide is produced from the amyloid precursor protein (APP) by sequential proteolytic cleavage of APP first by β-secretase and then by γ-secretase. β-Site APP cleaving enzyme-1 (BACE-1) is the predominant enzyme involved in β-secretase processing of APP and is a primary therapeutic target for treatment of Alzheimer's disease. While inhibiting BACE-1 activity has obvious therapeutic advantages, BACE-1 also cleaves numerous other substrates with important physiological activity. Thus, blanket inhibition of BACE-1 function may have adverse side effects. We isolated a single chain variable fragment (scFv) from a human-based scFv yeast display library that selectively inhibits BACE-1 activity toward APP by binding the APP substrate at the proteolytic site. We selected the iBSEC1 scFv, since it recognizes the BACE-1 cleavage site on APP but does not bind the adjacent highly antigenic N-terminal of Aβ, and thus it will target APP but not soluble Aβ. When added to 7PA2 cells, a mammalian cell line that overexpresses APP, the iBSEC1 scFv binds APP on the cell surface, reduces toxicity induced by APP overexpression, and reduces both intracellular and extracellular Aβ levels by around 50%. Since the iBSEC1 scFv does not contain the antibody Fc region, this construct does not pose the risk of exacerbating inflammation in the brain as faced with full-length monoclonal antibodies for potential therapeutic applications. 相似文献
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Chemical P extraction from soils is an indirect and frequently questionable index for P availability. To monitor the dynamics of P availability in soils more directly following the application of P fertilizer, manure or sludge, a rapid, whole-plant bioassay was developed using tomato (Lycopersicon esculentum Mill.), Chinese cabbage (Brassica rapa L. var.pekinensis) and wheat (Triticum aestivum L.). Plant P extracted in 0.1 M H2SO4 (Pi) and total P (Pt) concentration or content in stem, leaves or whole shoots were highly correlated (P < 0.01) with P fertilizer rates or water-soluble (WSP) or Olsen P in various soils, over wide ranges of soil P status. The whole-plant Pi content was found to be as informative as the more complicated indices of Pt or Piconcentration. The assay was used to compare availability of fertilizer-P and sewage-sludge-P after incorporation into alluvial soil during 1–100 days of incubation. While both soil and plant indices had shown that fertilizer-P was more highly available than sewage-sludge-P in each period, the bioassay was much more sensitive than the Olsen-P or WSP soil indices in showing P fixation and decrease of availability during incubation time. The bioassay is sufficiently rapid (5–12 days) to allow a study of short-term changes in soil-P availability following incorporation of various P additives, and it is applicable to a very wide range of P availability values (6–535 mg Olsen-P kg–1), extending from lower than desired for crop production to higher than permitted from an environmental standpoint. 相似文献
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Nora Vaisman Andrey Tsouladze Kenneth Robzyk Sigal Ben-Yehuda Martin Kupiec Yona Kassir 《Molecular genetics and genomics : MGG》1995,247(2):123-136
Successful progression through the cell cycle requires the coupling of mitotic spindle formation to DNA replication. In this report we present evidence suggesting that, inSaccharomyces cerevisiae, theCDC40 gene product is required to regulate both DNA replication and mitotic spindle formation. The deduced amino acid sequence ofCDC40 (455 amino acids) contains four copies of a β-transducin-like repeat. Cdc40p is essential only at elevated temperatures, as a complete deletion or a truncated protein (deletion of the C-terminal 217 amino acids in thecdc40-1 allele) results in normal vegetative growth at 23°C, and cell cycle arrest at 36°C. In the mitotic cell cycle Cdc40p is apparently required for at least two steps: (1) for entry into S phase (neither DNA synthesis, nor mitotic spindle formation occurs at 36°C and (2) for completion of S-phase (cdc40::LEU2 cells cannot complete the cell cycle when returned to the permissive temperature in the presence of hydroxyurea). The role of Cdc40p as a regulatory protein linking DNA synthesis, spindle assembly/maintenance, and maturation promoting factor (MPF) activity is discussed. 相似文献
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Vidalain PO Laine D Zaffran Y Azocar O Servet-Delprat C Wild TF Rabourdin-Combe C Valentin H 《Journal of virology》2002,76(13):6415-6424
In the thymus, epithelial cells comprise a heterogeneous population required for the generation of functional T lymphocytes, suggesting that thymic epithelium disruption by viruses may compromise T-cell lymphopoiesis in this organ. In a previous report, we demonstrated that in vitro, measles virus induced differentiation of cortical thymic epithelial cells as characterized by (i) cell growth arrest, (ii) morphological and phenotypic changes, and (iii) apoptotis as a final step of this process. In the present report, we have analyzed the mechanisms involved. First, measles virus-induced differentiation of thymic epithelial cells is shown to be strictly dependent on beta interferon (IFN-beta) secretion. In addition, transfection with double-stranded RNA, a common intermediate of replication for a broad spectrum of viruses, is reported to similarly mediate thymic epithelial cell differentiation through IFN-beta induction. Finally, we demonstrated that recombinant IFN-alpha, IFN-beta, or IFN-gamma was sufficient to induce differentiation and apoptosis of uninfected thymic epithelial cells. These observations suggested that interferon secretion by either infected cells or activated leukocytes, such as plasmacytoid dendritic cells or lymphocytes, may induce thymic epithelium disruption in a pathological context. Thus, we have identified a new mechanism that may contribute to thymic atrophy and altered T-cell lymphopoiesis associated with many infections. 相似文献
30.
Subcellular localization of isozymes of NAD-dependent malate dehydrogenase (MDH) in sugar beet was studied. Isozymes ss and ll controlled by loci Mdh2 and Mdh3, respectively, were shown to locate in mitochondria, whereas isozyme pp controlled by locus Mdh1, in microbodies. All examined samples lack hybrid MDH isozymes, which could testify to the interaction between products of nonallelic Mdh genes. This can be explained by the localization of nonallelic isozymes in various compartments of the cell and organelles. 相似文献