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1.
Self-association of human erythrocyte glycophorin A. Appearance of low mobility bands on sodium dodecyl sulfate gels 总被引:2,自引:0,他引:2
We have examined the self-association of glycophorin A, the major sialoglycoprotein of the human erythrocyte membrane, using sodium dodecyl sulfate (SDS) polyacrylamide gels and circular dichroism. Pure glycophorin A has a tendency to form multiple bands on SDS gels at positions of higher apparent molecular weight than the PAS 1 and PAS 2 bands previously seen. These high molecular weight bands do not have mobilities corresponding to integral polymers of PAS 1 and PAS 2. Circular dichroism spectra of solutions giving rise to these bands or to PAS 1 and PAS 2 bands alone, indicate that these species all have essentially the same peptide conformation. 相似文献
2.
Pulmonary macrophages in pre- and postnatal rats were examined histochemically with a battery of peroxidase labeled lectins. Among them, Griffonia simplicifolia agglutinin I-B4 (GSA I-B4) which binds specifically to terminal alpha-galactose showed selective affinity in lung for the monocyte-macrophage line. These cells were demonstrable with GSA I-B4 from the 14th day of gestation through the adult. Extension to the ultrastructural level showed strong selective binding of this lectin to the surface of the plasmalemma and inner face of membranes limiting phagosomes in macrophages. At day 14 of gestation, monocyte-like cells positive with GSA I-B4 were scattered in various organs including lung. The lectin reactive cells in lung increased in number and size with development, infiltrating the interstitium through day 20 of gestation and then also entering the alveolar space. These findings suggest that GSA I-B4 recognizes a surface glycoconjugate characteristic of the pulmonary monocyte-macrophage line. Such selective lectin affinity offers a marker for detecting the pulmonary macrophages and examining their kinetics by light and electron microscopy. 相似文献
3.
E Schulte N A Dimitrova G V Dimitrov G Rau C Disselhorst-Klug 《Journal of electromyography and kinesiology》2005,15(3):290-299
Changes in muscle fibre length and surface electrode position with respect to the muscle fibres affect the amplitude and frequency characteristics of surface electromyography (SEMG) in different ways. Knowledge of changes in muscle fibre length would help towards a better interpretation of the signals. The possibility of estimating the length through SEMG during voluntary contractions was checked in this study. The fibres' semi-length was estimated from the product of the conduction velocity and conduction time during which the wave of excitation propagated from the end-plate region to the ends of the fibres. Short (10 s), moderate (30% of maximum voluntary contraction) isometric contractions were performed by 10 subjects at different elbow joint angles (80-140 degrees in steps of 20 degrees ). Monopolar signals were detected non-invasively, using a two-dimensional electrode array. High spatial resolution EMG and a decomposition technique were utilised to extract single motor unit activities for triggered averaging and to estimate conduction velocity. A significant increase with joint angle was found in conduction time and estimated fibre semi-length. Changes in conduction velocity with joint angle were found to be not significant. The methodology described allows the relative changes in fibres' semi-length to be estimated from SEMG data. 相似文献
4.
Several glycoconjugates are thought to bind spermatozoa as they pass through reproductive ducts. Paraffin sections of testis, ductuli efferentes, epididymis, and vas deferens of male mice were stained with ten different lectin-horseradish peroxidase conjugates to localize possible sites of synthesis and secretion of such glycoconjugates, based on the carbohydrate moieties in their constituent oligosaccharide side chains. Principal (columnar) cells lining the efferent ducts, germinal epithelium, and developing and maturing spermatozoa were examined with light microscopy. Staining of the Golgi and apical zones of cells was interpreted as evidence for synthesis and secretion of glycoconjugates. Principal cells synthesized and secreted glycoconjugates with sugar moieties as follows: sialic acid, all regions of the efferent ducts examined; the terminal disaccharide D-galactose- (beta 1----3) -N-acetyl-D-galactosamine, all regions of ducts except epididymis I; terminal alpha-D-galactosamine, some cells in epididymis III-V; N-acetyl-D-galactosamine, ductuli efferentes, epididymis I, II, and some cells in epididymis III-V; alpha-L-fucose, ductuli efferentes, vas deferens, and all regions of the epididymis except IV; N-glycosidic side chains, ductuli efferentes, vas deferens, and epididymis I, IV, and V. All of these sugar residues as well as N-acetyl-D-glucosamine were associated with the acrosomes and tails of spermatozoa throughout the ducts except for alpha-N-acetyl-D-galactosamine in epididymis I, and all occurred during one or more stages of spermiogenesis. The synthesis and secretion of glycoconjugates that bind to spermatozoa appear to involve more regions of the primary reproductive structures than was believed previously. 相似文献
5.
Harry Holthöfer M.D. Ph.D. Bradley A. Schulte Samuel S. Spicer 《Cell and tissue research》1987,249(3):481-485
Summary To identify precisely the structural and functional cell type in the collecting duct of the rat kidney expressing binding sites for Dolichos biflorus agglutinin (DBA), we stained serial paraffin sections of kidney with horseradish peroxidase-labeled DBA and with immunocytochemical methods for localizing (Na++K+)-ATPase and carbonic anhydrase II (CA II), enzymes found preferentially in principal and intercalated cells, respectively. Most principal cells expressing a strong basolateral staining for (Na+ + K+)-ATPase showed binding sites for DBA at their luminal surfaces. However, a minority of cells rich in CA II and showing morphologic characteristics of intercalated cells also expressed DBA binding sites at their luminal surface and apical cytoplasm. These data suggest that DBA cytochemistrycan provide a useful tool for studying the functional polarity of the main cell types of the collecting duct of the rat kidney. 相似文献
6.
Summary The apical surface coat of type II pneumocytes and Clara cells in pre- and post-natal rat lung was examined with lectin histochemical methods. Lectins fromHelix pomatia (HPA), peanut (PNA) andMaclura pomifera (MPA) were conjugated with horseradish peroxidase and used to stain paraffin sections of fixed lung with or without certain pre-treatments. HPA and MPA were observed to react with almost all type II pneumocytes at postnatal day 1. Type II pneumocytes that stained with a sialidase—PNA sequence increased from a few positive cells at postnatal day 5 to many in the adult. It has been reported that the surface coat of type II pneumocytes closely resembles that of Clara cells in its staining with histochemical methods employing cationic dyes or lectins including MPA and PNA. However, staining with HPA, especially after periodic acid oxidation, revealed many type II pneumocytes with strong reactivity but showed only a few Clara cells that were faintly positive. HPA also stained alveolar macrophages. The HPA affinity of macrophages, however, was labile to oxidation with periodic acid or galactose oxidase unlike that of type II pneumocytes. This difference suggests that HPA recognizes more than one type of sugar structure.To whom all correspondence and reprint requests should be addressed. 相似文献
7.
Immunohistochemical localization of Na+,K+-ATPase in rodent and human salivary and lacrimal glands 总被引:1,自引:0,他引:1
D C Winston R A Hennigar S S Spicer J R Garrett B A Schulte 《The journal of histochemistry and cytochemistry》1988,36(9):1139-1145
The enzyme Na+,K+-ATPase was localized immunohistochemically in major salivary glands of mouse, rat, and human and in exorbital lacrimal glands of the rodents. Immunoreactive Na+,K+-ATPase was abundant in the basolateral membranes of all epithelial cells lining striated and intra- and interlobular ducts of all glands. Reactivity of intercalated ducts varied among gland type and species. Cells lining granular ducts in rodent submandibular gland showed a heterogeneous staining pattern in rat but stained homogeneously in mouse. Secretory cells varied greatly in their content of immunoreactive Na+,K+-ATPase. As with all duct cells, staining was present only at the basolateral surface and was never observed at the luminal surface of reactive secretory cells. Mucous cells failed to show any reactivity in any gland examined. Serous cells showed a gradient of immunostaining intensity ranging from strongly positive in demilunes of human sublingual gland to negative in rat submandibular gland and lacrimal glands of rats and mice. The presence of basolaterally localized Na+,K+-ATPase in most serous cells but not in mucous cells suggests that the enzyme contributes to the ion and water content of copious, low-protein serous secretions. The intense immunostaining of cells in most if not all segments of the duct system supports the idea that the ducts are involved with modification of the primary saliva, and extends this concept to include all segments of the duct system. 相似文献
8.
9.
Y. Ziv M. Frydman E. Lange N. Zelnik G. Rotman C. Julier N. G. J. Jaspers Y. Dagan D. Abeliovicz H. Dar Z. Borochowitz M. Lathrop R. A. Gatti Y. Shiloh 《Human genetics》1992,88(6):619-626
Summary Ataxia-telangiectasia (A-T) is a progressive autosomal recessive disease featuring neurodegeneration, immunodeficiency, chromosomal instability, radiation sensitivity and a highly increased proneness to cancer. A-T is ethnically widespread and genetically heterogeneous, as indicated by the existence of four complementation groups in this disease. Several A-T-like genetic diseases share various clinical and cellular characteristics with A-T. By using linkage analysis to study North American and Turkish A-O families, the ATA (A-T, complementation group A) gene has been mapped to chromosome 11q23. A number of Israeli Arab A-T patients coming from large, highly inbred families were assigned to group A In one of these families, an additional autosomal recessive disease was identified, characterized by ataxia, hypotonia, microcephaly and bilateral congenital cataracts. In two patients with this syndrome, normal levels of serum immunoglobulins and alpha-fetoprotein, chromosomal stability in peripheral blood lymphocytes and skin fibroblasts, and normal cellular response to treatments with X-rays and the radiomimetic drug neocarzinostatin indicated that this disease does not share, with A-T, any additional features other than ataxia. These tests also showed that another patient in this family, who is also mentally retarded, is affected with both disorders. This conclusion was further supported by linkage analysis with 11q23 markers. Lod scores between A-O and these markers, cumulated over three large Arab families, were significant and confirmed the localization of the ATA gene to aq23. However, another Druze family unassigned to a specific complementation group, showed several recombinants between A-T and the same markers, leaving the localization of the A-T gene in this family open. 相似文献
10.