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991.
Proper chromosome segregation is required to maintain the appropriate number of chromosomes from one cell generation to the next and to prevent aneuploidy, the condition in which a cell has gained or lost one or several chromosomes during cell division. Aneuploidy is a hallmark associated with birth defects and cancer, and is observed at relatively high frequencies in human somatic cells. Recent studies in mammalian tissue culture cells suggest that the persistence of kinetochore-microtubule misattachments through mitosis is a major cause of chromosome mis-segregation and aneuploidy. Furthermore, studies in mice and humans suggest that small changes in the expression, rather than complete inactivation, of genes encoding specific proteins might be associated with aneuploidy in living organisms. In this article (which is part of the Chromosome Segregation and Aneuploidy series), we survey the outcome of these studies, focusing on the importance of kinetochore misattachments in producing aneuploid cells. 相似文献
992.
The aim of our study was to analyse the cytoskeletal organization of prepubertal goat oocytes. Microtubule and microfilament organization during in vitro maturation of prepubertal and adult goat oocytes and presumptive zygotes of in vitro matured-in vitro fertilized (IVM-IVF) prepubertal goat oocytes were analysed. Oocytes were matured in M-199 with hormones and serum and inseminated with frozen-thawed sermatozoa. Oocytes and presumptive zygotes were treated with anti-alpha-tubulin antibody and fluorescein isothiocyanate (FITC)-labelled goat anti-mouse antibody to stain the microtubules. Microfilaments were localized by means of phalloidin 5 microg/ml conjugated with fluorescein isothiocyanate (FITC-phalloidin). DNA was stained with propidium iodide. Stained oocytes were observed under a confocal laser scanning microscope. At the germinal vesicle nuclear stage, microfilaments were distributed at the cortex of the oocytes. After in vitro maturation, 91.7% of metaphase II (MII) oocytes from adult goats displayed microfilaments in the cortex and within the polar body and were characterized by the presence of a microfilament thickening at the cortical region over the meiotic spindle. In prepubertal goat MII oocytes only 5.7% of oocytes displayed microfilaments at the cortex and within the polar body. After insemination, most of the zygotes displayed microfilaments distributed at the cortex. An undefined microtubular network was observed in adult and prepubertal goat oocytes at the germinal vesicle stage. After in vitro maturation, 100% of MII oocytes from adult goats displayed microtubules on the meiotic spindle and within the polar body. This pattern of distribution was observed in 71.6% of prepubertal goat oocytes. Undefined microtubule networks were present in most of the zygotes analysed. In conclusion, cytoskeletal differences were found between prepubertal and adult goat MII oocytes. Furthermore, most of the zygotes from IVM-IVF prepubertal goat oocytes displayed cytoskeletal anomalies. 相似文献
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994.
Reddy MV Mallireddigari MR Pallela VR Venkatapuram P Boominathan R Bell SC Reddy EP 《Bioorganic & medicinal chemistry》2005,13(5):1715-1723
A new series of styryl acetoxyphenyl sulfides and sulfones possessing (E)- and (Z)-configurations were designed and prepared by stereospecific syntheses. All these compounds were evaluated for their ability to inhibit COX-2 enzyme in vitro. Structure-activity relationship studies on these compounds revealed that only sulfides with (Z)-configuration have potential COX-2 inhibitory activity. This inactivation of the enzyme is believed to be due to the selective covalent modification of COX-2 by the inhibitors. 相似文献
995.
996.
Variation in macrophage-migration-inhibitory-factor immunoreactivity during porcine gestation 总被引:1,自引:0,他引:1
The localization and activity of macrophage migration inhibitory factor (MIF) was investigated in the interhemal region of the noninvasive, diffuse, folded epitheliochorial placenta and in the nonpregnant uterus of the pig. MIF, a proinflammatory cytokine with many actions on macrophages and monocytes, may play an important role in materno-fetal immuno-tolerance during placental establishment, modulation, and growth. Immunohistochemical staining with anti-human MIF polyclonal antibodies was carried out on placental sections from 11 stages of gestation (16-95 days postcoitus) and on nonpregnant uterus at 13 days postestrus. Western blot analysis confirmed the specificity of the anti-human MIF polyclonal antibodies on pig tissues. MIF staining was intense in both the trophoblast and maternal epithelium in the early stages; in the later stages, it decreased dramatically in the maternal epithelium but remained high in the trophoblast. The uterine glands showed immunoreactivity at all stages, and the maternal and fetal epithelial linings of the areolar cavity showed high reactivity at Day 25. The vasculature also showed staining for MIF, and an intense to moderate staining was shown in the nonpregnant uterus, mostly in the surface and glandular epithelium. The high activity of MIF in the maternal and fetal tissues throughout placentation and its expression in the nonpregnant uterus indicate a regulatory role for MIF during embryo receptivity and epitheliochorial placentation. 相似文献
997.
Holmes S Friese MA Siebold C Jones EY Bell J Fugger L 《Expert reviews in molecular medicine》2005,7(3):1-17
Multiple sclerosis (MS) is an autoimmune disease with an important genetic component. The strongest genetic association is with the major histocompatibility complex (MHC) region. Several MHC alleles predispose to the disease, the most prominent of which are certain alleles in the HLA-DR2 haplotype. Functional and structural studies have helped to explain the molecular basis of these associations. Although there is currently no curative treatment for MS, an increased understanding of the disease has aided the design of immunotherapies that act on the immune system more specifically than the longstanding drugs. Many of these therapies work at the antigen-specific level, disrupting the interaction between T-cell receptors and MHC molecules that leads to disease. 相似文献
998.
999.
1000.
Miguel Quintana Peter Lindell Samir K Saha Francesca del Furia Britta Lind Satish Govind Lars-Åke Brodin 《Cardiovascular ultrasound》2005,3(1):1-12