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41.
Summary Purified hepatitis B virus particles were obtained from HBeAg positive serum by sucrose gradient ultracentrifugation and sephadex G-200 gel filtration. These virions formed a precipitation line in counterimmune electrophoresis with anti-albumin antibody, but the reaction could be inhibited by anti-HBs. After two months at 4°C, another precipitating line was formed under the same condition which could not be inhibited by anti-HBs and was, thus, due to free albumin. When that sample was incubated at 37°C overnight, the line of free albumine disappeared. The virion bound albumin was monomeric in non-denaturing gel electrophoresis. These results suggest that a reversible binding between virion and albumin may occur in vivo and does not require chemical modification or cross-linking.  相似文献   
42.
Abstract: Low and high resolution sequence specific oligonucleotide probe hybridization patterns were used to design an approach to direct sequencing of allele specific amplified cDNA. Several PCR amplifications were used to derive overlapping sequence fragments to define complete first domain sequences for a single allele. This method has been used to characterize three new DRB1 alleles in the DR52 family, DRB1*1115, DRB1* 1117, and DRB1*1319. All three alleles carry polymorphisms previously observed in other DRB alleles and underscore the importance of utilizing a directed sequencing approach for obtaining unambiguous typing results in matching for bone marrow transplantation between unrelated donor and recipient.  相似文献   
43.
Yuan X  Yao Z  Shan Y  Chen B  Yang Z  Wu J  Zhao Z  Chen J  Cong Y 《Virus research》2005,114(1-2):70-79
The open reading frame 3 (ORF3) of the severe acute respiratory syndrome coronavirus (SARS-CoV) genome encodes a predicted 154-amino acid protein, which lacks similarities to any known protein, and is named 3b. In this study, it was shown that 3b protein was predominately localized to nucleus with EGFP tag at its N- or C-terminus. The localization patterns were similar in different transfected cells. Immuno-fluorescence assay revealed that 3b protein was co-localized well with C23 in nucleolus. C23, B23 and fibrillarin all are important nucleolar proteins, which localize in the region of the nucleolus. Co-transfection of p3b-EGFP with pC23-DsRed, pB23-DsRed and pfibrillarin-DsRed further confirmed 3b's nucleolus localization. With construction of serial truncated mutants of 3b, a region (residues 134-154 aa) responsible for nucleolar localization was determinated in 3b protein. These results provide a new insight for further functional studies of SARS-CoV 3b protein.  相似文献   
44.
Gene therapy is defined as the introduction of a therapeutic gene into a cell, whose expression can lead to a cure of a disease or offer a transient advantage for tissue growth and regeneration. The delivery of genes can be undertaken for a number of purposes, usually it is attempted to enhance or add a function to a cell or a tissue or to delete or reduce another function. In this brief overview we describe various vehicles and techniques that have been developed to deliver therapeutic genes into cells, such as viral vectors and physical/chemical gene delivery methods including naked DNA and particle-mediated gene transfer, the microseeding technique and the application of lipids. Furthermore we review the potential utility of gene therapy from the perspective of a reconstructive surgeon. Several tissues will be discussed, particularly muscle, tendon, nerve, bone, skin and wounds.  相似文献   
45.
Several lines of evidence indicate that mammalian fertilization is initiated via a binding process that is dependent upon the recognition of oligosaccharide sequences associated with zona pellucida (ZP) glycoproteins. Here, specific chemical and enzymatic methods were employed to modify human ZP and to test their effects on sperm binding in the hemizona assay system (HZA). Periodate oxidation of human ZP under very mild conditions (10 min, 0 degrees C, 1 mM sodium m- periodate) that attacks only terminal sialic acid resulted in a 30% loss of human sperm binding in the HZA [hemizona index (HZI) = 70.2 +/- 10.9, n = 22; P < 0.05]. Periodate oxidation under mild conditions (1 h, 23 degrees C, 10 mM sodium m-periodate) caused a 40% decrease in binding (HZI = 60.8 +/- 10.3; n = 24; P< 0.01). Treatment of human ZP with neuraminidase caused a substantial increase in sperm binding to human ZP (HZI = 297 +/- 45, n = 22; P < 0.01). These findings indicate that there are sialic acid dependent binding sites coexisting with binding sites that are obscured by sialic acid. To determine the periodate sensitivity of these obscured sites, hemizona were first digested with neuraminidase and subsequently subjected to mild periodate oxidation. The combined enzymatic and chemical treatments caused a 79% decrease in sperm binding compared to control hemizona (HZI = 20.7 +/- 4.4, n = 16; P < 0.001). Human sperm-ZP interaction was also increased by digestion of human ZP with endo-beta-galactosidase (HZI = 710 +/- 232, n = 14; P < 0.01), indicating that potential binding sites for spermatozoa are also obscured by lactosaminoglycan sequences. These studies support a definitive role for the involvement of ZP-associated glycans in the binding of human spermatozoa to oocytes.   相似文献   
46.
Citrin is a mitochondrial aspartate glutamate carrier primarily expressed in the liver, heart, and kidney. We found that adult-onset type II citrullinemia is caused by mutations in the SLC25A13 gene that encodes for citrin. In this report, we describe the frequency of SLC25A13 mutations, the roles of citrin as a member of the urea cycle and as a member of the malate-aspartate shuttle, the relationship between its functions and symptoms of citrin deficiency, and therapeutic issues.  相似文献   
47.

Background  

In multiple sclerosis, inflammatory cells are found in both active and chronic lesions, and it is increasingly clear that cytokines are involved directly and indirectly in both formation and inhibition of lesions. We propose that cytokine mixtures typical of Th1 or Th2 lymphocytes, or monocyte/macrophages each induce unique molecular changes in glial cells.  相似文献   
48.
Objective: The effect of rosiglitazone, a potent peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, on pulmonary inflammation in endotoxemia was investigated. Materials and methods: Male Wistar rats were given either lipopolysaccharide (LPS, 6 mg/kg i.v.) or saline, pretreated with rosiglitazone (0.3 mg/kg i.v.) or its vehicle (dimethyl sulphoxide) 30 min before LPS. The selective PPAR-γ antagonist GW9662 (0.3 mg/kg i.v.) was given 20 min before rosiglitazone. Wet/dry weight (W/D) ratio, myeloperoxidase (MPO) activity, malondialdehyde (MDA) as well as TNF-α and CINC-1 concentrations were measured in lung tissues 4 h after LPS injection. Expression of ICAM-1, NF-κB p65 and PPAR-γ were also determined by immunohistochemistry or Western blot analysis. Results: Rosiglitazone pretreatment significantly attenuated the increases in W/D ratio, MPO activity and MDA levels, and reduced pulmonary overproduction of TNF-α and CINC-1 as well as expression of ICAM-1 following endotoxemia. Rosiglitazone also inhibited the nuclear localization of NF-κB and up-regulated the expression of PPAR-γ protein. The specific PPAR-γ antagonist GW9662 abolished the effect of rosiglitazone. Conclusion: These findings suggest that PPAR-γ agonists might be used as therapeutic agents in the therapy of inflammatory lung injury related to endotoxemia. Received 8 January 2005; returned for revision 6 July 2005; returned for final revision 20 July 2005; accepted by M. Katori 31 July 2005  相似文献   
49.
神经导航中脑组织变形补偿的点云处理   总被引:1,自引:0,他引:1  
有限元方法是解决神经导航中脑组织变形的重要方法,需要手术过程中的脑皮层信息作为其边界条件.本文通过非结构点云进行了脑皮层信息的表示,并通过对其进行处理来获取有限元方法的边界条件.点云处理包括纹理映射、分割、简化和去噪,其中非结构点云的简化与去噪采用了改进的基于表面特性k邻域的聚类方法.实验结果证明所采用的点云处理方法是可靠的.  相似文献   
50.
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