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1.
Concanavalin-A points of linkage were positively detected on cell membranes of alveolar and peritoneal macrophages by means of Con-A ferritin conjugate. Quantitative conclusions were drawn from these findings with regard to the number of mannose and glucose residues per 1 micron 2 of membrane area. With different incubation periods, 15, 25, and 45 minutes, various distribution patterns of ferritin molecules were recorded. They were diffusely distributed in cytoplasma as well as on the outer nuclear membrane. Ferritin particles were identified also on vacuolar membranes and in direct contact with lysosomes.  相似文献   

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The quantitative changes of the yolk, albumen and amniotic-allantoic fluids have been established. The development of the extraembryonic membranes and ultrastructural changes of the chorioallantoic membrane (CAM) were investigated in goose during the incubation.  相似文献   

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The SDS-PAGE patterns of the outer membrane protein (OMP) extracts of Pasteurella multocida strain P1059, grown under iron-restricted, iron-replete and in vivo conditions, were examined. The results showed that the iron-regulated outer membrane proteins (IROMPs) with molecular masses of 76 kDa, 84 kDa, and 94 kDa were expressed by bacteria grown in iron-restricted media. They were also expressed by in vivo grown P. multocida. Convalescent-phase sera, obtained from turkeys which had survived pasteurellosis, contained antibodies that reacted intensly with th three IROMPs. This indicated that these proteins were expressed in vivo. Bacteria expressing the IROMPs showed greater binding to Congo Red when compared to cells not expressing IROMPs. Cells expressing the IROMPs or its OMP extracts grown in iron-restricted media also showed greater binding to 59Fe-pasteurella siderophore (multocidin) when compared to bacteria or its extracts not expressing IROMPs. Convalescent-phase sera, which contained antibodies against the IROMPs, blocked this specific 59Fe-multocidin binding to IROMPs. Autoradiography was used to determine which of these IROMPs functioned as a receptor for the iron-multocidin complex. The results suggested that these three IROMPs have specific epitopes for binding to the iron multocidin complex.  相似文献   

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The clinical signs and treatment of the following conditions of the nictitating membrane are described–prominence of the nictitating membrane due to various causes, injuries and foreign bodies, conjunctivitis, plasma cell infiltration, disorders of the nictitans gland, neoplasia, and deformity of the cartilage. The surgical removal of the third eyelid is also discussed.  相似文献   

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本实验通过高效液相色谱法(HPLC)分析植酸酶发酵液相对分子质量大于2000的物质中,植酸酶的含量为77.52%,植酸酶的相对分子质量约40000,实验分别选用截留相对分子质量为5000和100000的超滤膜处理植酸酶发酵液,超滤后植酸酶蛋白含量达90%。在25℃避光保存6个月,液态植酸酶样品浊度有所上升,但未见明显沉淀现象。  相似文献   

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猪肺炎支原体膜蛋白的电泳分析及免疫印迹检测   总被引:1,自引:1,他引:0  
以猪肺炎支原体Z株为试验材料,采用SDS-PAGE和Western印迹对该菌膜蛋白进行了分析。研究表明:猪肺炎支原体经A_(26)液体培养基培养,15000 r/min离心收集菌体细胞,低渗超声法破膜获得膜制剂后,应用12.5%的凝胶对膜蛋白进行SDS-PAGE分离,在电泳图谱上呈现出36条蛋白带,相对分子质量范围为1.18×10~4~9.12×10~4。同时以膜制剂作为抗原,分4次免疫试验兔,心脏采血,提取抗血清,并分离纯化得到IgG,然后进行Western印迹法检测。其结果发现在SDS-PAGE分离得到的36种膜蛋白(或多肽)中,有6种蛋白具有免疫原性。  相似文献   

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Cell secretion and membrane fusion   总被引:4,自引:0,他引:4  
Secretion occurs in all cells of multicellular organisms and involves the delivery of secretory products packaged in membrane-bound vesicles to the cell exterior. Specialized cells for neurotransmission, enzyme secretion or hormone release utilize a highly regulated secretory process. Secretory vesicles are transported to specific sites at the plasma membrane, where they dock and fuse to release their contents. Similar to other cellular processes, cell secretion is found to be highly regulated and a precisely orchestrated event. It has been demonstrated that membrane-bound secretory vesicles dock and fuse at porosomes, which are specialized supramolecular structures at the cell plasma membrane. Swelling of secretory vesicles results in a build-up of pressure, allowing expulsion of intravesicular contents. The extent of secretory vesicle swelling dictates the amount of intravesicular contents expelled during secretion. The discovery of the porosome, its isolation, its structure and dynamics at nm resolution and in real time, its biochemical composition and functional reconstitution into artificial lipid membrane, have been determined. The molecular mechanism of secretory vesicle fusion at the base of porosomes, and vesicle swelling, has also been resolved. These findings reveal the molecular mechanism of cell secretion.  相似文献   

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A 15-year-old Haflinger gelding presented with a mass in the left nictitating membrane. Two biopsies and the excised nictitating membrane were taken at different time points as a result of reoccurrence of the mass and submitted for histopathologic evaluation. The horse was euthanized as a result of poor prognosis following the reoccurrence of the mass after surgical removal. Histologically, the mass consisted of dilated, thin-walled vascular clefts and channels, lined by flattened to cuboidal endothelial cells with moderate cellular pleomorphism. There was up to 1 mitotic figure per high power field. The channels were empty or contained few erythrocytes. In the collagen-rich stroma, few lymphocytes, focal follicular lymphoid aggregations, and marked lymphangiectasia were observed. Immunohistochemically, the neoplastic cells stained positive for vimentin and partially positive for factor VIII-related antigen. Ultrastructural analysis revealed discontinuous endothelial lining vascular channels that partially lacked a basal membrane. Based on the histopathologic, immunohistochemical, and ultrastructural features lymphangiosarcoma was diagnosed.  相似文献   

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OBJECTIVE: To evaluate the value of microarthroscopy in the equine midcarpal joint using the vital stains methylene blue, trypan blue, neutral red, and Janus green B to observe components of the synovial lamina propria, vascular architecture, and synoviocytes. STUDY DESIGN: Experimental. ANIMALS: Ten horses. METHODS: Microarthroscopy of left and right midcarpal joints was performed with and without vital staining of the synovium. Four vital stains (methylene blue, trypan blue, neutral red, and Janus green B) were evaluated, with each stain used in 5 joints. Synovial biopsy specimens were collected from the dorsomedial and dorsolateral aspects of the joint. RESULTS: All dyes were biocompatible. At x 60 without vital staining, synovial surface topography, vascular network, and translucency were observed. Intra-articular vital dyes improved evaluation of synovial surface topography. At x 150 with vital staining, individual synoviocytes were clearly identified with all dyes, except neutral red. Although methylene blue provided the best in vivo microscopic differentiation of the structure of the intima, trypan blue had superior retention in conventionally processed synovial biopsies. CONCLUSIONS: Methylene blue, trypan blue, neutral red, and Janus green B stains can be used safely for microarthroscopy. Good visualization of cells and vascular network can be obtained by microarthroscopy, and microarthroscopic evaluation of the synovium compares favorably with conventional histologic evaluation of biopsy specimens. CLINICAL RELEVANCE: Microarthroscopy may be beneficial in both research and clinical diagnosis of equine articular diseases.  相似文献   

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The capacitation process of sperm cells involves complex changes in the composition and orientation of molecules at the surface of the sperm cell. Here we focus on the lipid architecture in the sperm plasma membrane and demonstrate that the sperm plasma membrane is not static but is an extremely dynamic structure. Advanced fluoroscopic techniques enabled continuous monitoring of lipid organization in living cells and extremely rapid lipid movements were observed. The orientation of lipids in the sperm plasma membrane changed under capacitative treatments, was found to be sensitive for temperature and also changed upon binding of sperm cells to the zona pellucida. The changes in membrane properties coincided with an activation of protein kinases resulting in tyrosine phosphorylation of specific plasma membrane proteins. The detected membrane changes relate to intrinsic membrane properties such as fluidity, permeability, adhesiveness and fusibility. We think that these results may provide a physiological basis for new assays, able to discriminate between functional and non-physiological sperm cells.  相似文献   

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Summary

The capacitation process of sperm cells involves complex changes in the composition and orientation of molecules at the surface of the sperm cell. Here we focus on the lipid architecture in the sperm plasma membrane and demonstrate that the sperm plasma membrane is not static but is an extremely dynamic structure. Advanced fluoroscopic techniques enabled continuous monitoring of lipid organization in living cells and extremely rapid lipid movements were observed. The orientation of lipids in the sperm plasma membrane changed under capacitative treatments, was found to be sensitive for temperature and also changed upon binding of sperm cells to the zona pellucida. The changes in membrane properties coincided with an activation of protein kinases resulting in tyrosine phosphorylation of specific plasma membrane proteins. The detected membrane changes relate to intrinsic membrane properties such as fluidity, permeability, adhesiveness and fusibility. We think that these results may provide a physiological basis for new assays, able to discriminate between functional and non‐physiological sperm cells.  相似文献   

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