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51.
Johansen RE 《Medical anthropology quarterly》2002,16(3):312-340
This article focuses on how some Somali women experience and reflect on the pain of infibulation as a lived bodily experience within shifting social and cultural frameworks. Women interviewed for this study describe such pain as intolerable, as an experience that has made them question the cultural values in which the operation is embedded. Whereas this view has gone largely unvoiced in their natal communities, the Norwegian exile situation in which the present study's informants live has brought about dramatic changes. In Norway, where female circumcision is both condemned and illegal, most of the women have come to reconsider the practice--not merely as a theoretical topic or as a "cultural tradition" to be maintained or abolished but, rather, as part of their embodied and lived experience. 相似文献
52.
Brykov VA Poliakova NE Skurikhina LA Dolganov SM Eliseĭkina MG Kovalev MIu 《Genetika》2002,38(10):1387-1392
MtDNA variation of goldfish samples from several water bodies of Southern Primorye was examined by RFLP analysis. High mtDNA polymorphism was found in the river populations but not in the lake ones. Considerable among-haplotype divergence was found within samples, which suggests periodic gene exchange between populations having long histories of independent evolution. The absence of substantial differences between clusters of mtDNA haplotypes indicates recurrent transfer from bisexual to gynogenetic reproduction mode and vice versa. 相似文献
53.
Angelina J Lay Xing-Mai Jiang Elise Daly Lisa Sun Philip J Hogg 《The Journal of biological chemistry》2002,277(11):9062-9068
Phosphoglycerate kinase (PGK) is secreted by tumor cells and facilitates reduction of disulfide bond(s) in plasmin (Lay, A. J., Jiang, X.-M., Kisker, O., Flynn, E., Underwood, A., Condron, R., and Hogg, P. J. (2000) Nature 408, 869-873). The angiogenesis inhibitor, angiostatin, is cleaved from the reduced plasmin by a combination of serine- and metalloproteinases. The chemistry of protein reductants is typically mediated by a pair of closely spaced Cys residues. There are seven Cys in human PGK, and mutation of all seven to Ala did not appreciably affect plasmin reductase activity, although some of the mutations perturbed the tertiary structure of the protein. Cys-379 and Cys-380 are close to the hinge that links the N- and C-terminal domains of PGK. Alkylation/oxidation of Cys-379 and -380 by four different thiol-reactive compounds reduced plasmin reductase activity to 7--35% of control. Binding of 3-phosphoglycerate and/or MgATP to the N- and C-terminal domains of PGK, respectively, triggers a hinge bending conformational change in the enzyme. Incubation of PGK with 3-phosphoglycerate and/or MgATP ablated plasmin reductase activity, with half-maximal inhibitory effects at approximately 1 mm concentration. In summary, reduction of plasmin by PGK is a thiol-independent process, although either alkylation/oxidation of the fast-reacting Cys near the hinge or hinge bending conformational change in PGK perturbs plasmin reduction by PGK, perhaps by obstructing the interaction of plasmin with PGK or perturbing conformational changes in PGK required for plasmin reduction. 相似文献
54.
Comparative proteome profiling and functional analysis of chronic myelogenous leukemia cell lines 总被引:1,自引:0,他引:1
Fontana S Alessandro R Barranca M Giordano M Corrado C Zanella-Cleon I Becchi M Kohn EC De Leo G 《Journal of proteome research》2007,6(11):4330-4342
The aim of the present study was the molecular profiling of different Ph+ chronic myelogenous leukemia (CML) cell lines (LAMA84, K562, and KCL22) by a proteomic approach. By employing two-dimensional gel electrophoresis combined with mass spectrometry analysis, we have identified 191 protein spots corresponding to 142 different proteins. Among these, 63% were cancer-related proteins and 74% were described for the first time in leukemia cells. Multivariate analysis highlighted significant differences in the global proteomic profile of the three CML cell lines. In particular, the detailed analysis of 35 differentially expressed proteins revealed that LAMA84 cells preferentially expressed proteins associated with an invasive behavior, while K562 and KCL22 cells preferentially expressed proteins involved in drug resistance. These data demonstrate that these CML cell lines, although representing the same pathological phenotype, show characteristics in their protein expression profile that suggest different phenotypic leukemia subclasses. These data contribute a new potential characterization of the CML phenotype and may help to understand interpatient variability in the progression of disease and in the efficacy of a treatment. 相似文献
55.
Takano M Meneshian A Sheikh E Yamakawa Y Wilkins KB Hopkins EA Bulkley GB 《American journal of physiology. Heart and circulatory physiology》2002,283(5):H2054-H2061
Endothelial cell ICAM-1 upregulation in response to TNF-alpha is mediated in part by reactive oxygen species (ROS) generated by the endothelial membrane-associated NADPH oxidase and occurs maximally after 4 h as the synthesis of new protein is required. However, thrombin-stimulated P-selectin upregulation is bimodal, the first peak occurring within minutes. We hypothesize that this early peak, which results from the release of preformed P-selectin from within Weibel-Palade bodies, is mediated in part by ROS generated from the endothelial membrane-associated xanthine oxidase. We found that this rapid expression of P-selectin on the surface of endothelial cells was accompanied by qualitatively parallel increases in ROS generation. Both P-selectin expression and ROS generation were inhibited, dose dependently, by the exogenous administration of disparate cell-permeable antioxidants and also by the inhibition of either of the known membrane-associated ROS-generating enzymes NADPH oxidase or xanthine oxidase. This rapid, posttranslational cell signaling response, mediated by ROS generated not only by the classical NADPH oxidase but also by xanthine oxidase, may well represent an important physiological trigger of the microvascular inflammatory response. 相似文献
56.
57.
Mandelate racemase (MR, EC 5.1.2.2) from Pseudomonas putida catalyzes the Mg(2+)-dependent interconversion of the enantiomers of mandelate, stabilizing the altered substrate in the transition state by 26 kcal/mol relative to the substrate in the ground state. To understand the origins of this binding discrimination, we determined the X-ray crystal structures of wild-type MR complexed with two analogues of the putative aci-carboxylate intermediate, benzohydroxamate and Cupferron, to 2.2-? resolution. Benzohydroxamate is shown to be a reasonable mimic of the transition state and/or intermediate because its binding affinity for 21 MR variants correlates well with changes in the free energy of transition state stabilization afforded by these variants. Both benzohydroxamate and Cupferron chelate the active site divalent metal ion and are bound in a conformation with the phenyl ring coplanar with the hydroxamate and diazeniumdiolate moieties, respectively. Structural overlays of MR complexed with benzohydroxamate, Cupferron, and the ground state analogue (S)-atrolactate reveal that the para carbon of the substrate phenyl ring moves by 0.8-1.2 ? between the ground state and intermediate state, consistent with the proposal that the phenyl ring moves during MR catalysis while the polar groups remain relatively fixed. Although the overall protein structure of MR with bound intermediate analogues is very similar to that of MR with bound (S)-atrolactate, the intermediate-Mg(2+) distance becomes shorter, suggesting a tighter complex with the catalytic Mg(2+). In addition, Tyr 54 moves closer to the phenyl ring of the bound intermediate analogues, contributing to an overall constriction of the active site cavity. However, site-directed mutagenesis experiments revealed that the role of Tyr 54 in MR catalysis is relatively minor, suggesting that alterations in enzyme structure that contribute to discrimination between the altered substrate in the transition state and the ground state by this proficient enzyme are extremely subtle. 相似文献
58.
59.
François Bilodeau Murray D. Bailey Punit K. Bhardwaj Josée Bordeleau Pat Forgione Michel Garneau Elise Ghiro Vida Gorys Ted Halmos Eric S. Jolicoeur Mélissa Leblanc Christopher T. Lemke Julie Naud Jeff O’Meara Peter W. White Montse Llinàs-Brunet 《Bioorganic & medicinal chemistry letters》2013,23(14):4267-4271
In this report we describe the synthesis and evaluation of diverse 4-arylproline analogs as HCV NS3 protease inhibitors. Introduction of this novel P2 moiety opened up new SAR and, in combination with a synthetic approach providing a versatile handle, allowed for efficient exploitation of this novel series of NS3 protease inhibitors. Multiple structural modifications of the aryl group at the 4-proline, guided by structural analysis, led to the identification of analogs which were very potent in both enzymatic and cell based assays. The impact of this systematic SAR on different drug properties is reported. 相似文献
60.
Elise A. Lamont Ping Wang Shinichiro Enomoto Klaudyna Borewicz Ahmed Abdallah Richard E. Isaacson Srinand Sreevatsan 《PloS one》2014,9(12)
Francisella tularensis, a Gram-negative bacterium and causative agent of tularemia, is categorized as a Class A select agent by the Centers for Disease Control and Prevention due to its ease of dissemination and ability to cause disease. Oropharyngeal and gastrointestinal tularemia may occur due to ingestion of contaminated food and water. Despite the concern to public health, little research is focused on F. tularensis detection in food and environmental matrices. Current diagnostics rely on host responses and amplification of F. tularensis genetic elements via Polymerase Chain Reaction; however, both tools are limited by development of an antibody response and limit of detection, respectively. During our investigation to develop an improved culture medium to aid F. tularensis diagnostics, we found enhanced F. tularensis growth using the spent culture filtrate. Addition of the spent culture filtrate allowed for increased detection of F. tularensis in mixed cultures of food and environmental matrices. Ultraperformance liquid chromatography (UPLC)/MS analysis identified several unique chemicals within the spent culture supernatant of which carnosine had a matching m/z ratio. Addition of 0.625 mg/mL of carnosine to conventional F. tularensis medium increased the growth of F. tularensis at low inoculums. In order to further enrich F. tularensis cells, we developed a DNA aptamer cocktail to physically separate F. tularensis from other bacteria present in food and environmental matrices. The combined enrichment steps resulted in a detection range of 1–106 CFU/mL (starting inoculums) in both soil and lettuce backgrounds. We propose that the two-step enrichment process may be utilized for easy field diagnostics and subtyping of suspected F. tularensis contamination as well as a tool to aid in basic research of F. tularensis ecology. 相似文献