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Biomedical subjects

S Winter

Publications and source records attributed to S Winter.

At least 127 records · Page 7Linked to original sources
PubMed1982

Detection of a cytokeratin determinant common to diverse epithelial cells by a broadly cross-reacting monoclonal antibody.

A monoclonal antibody derived from a mouse immunized with bovine epidermal prekeratin has been characterized by its binding to cytoskeletal polypeptides separated by one- or two-dimensional gel electrophoresis and by immunofluorescence microscopy. This antibody (KG 8.13) binds to a determinant present in a large number of human cytokeratin polypeptides, notably some polypeptides (Nos. 1, 5, 6, 7, and 8) of the 'basic cytokeratin subfamily' defined by peptide mapping, as well as a few acidic cytokeratins such as the epidermis-specific cytokeratins Nos. 10 and 11 and the more widespread cytokeratin No. 18. This antibody reacts specifically with a wide variety of epithelial tissues and cultured epithelial cells, in agreement with previous findings that at least one polypeptide of the basic cytokeratin subfamily is present in all normal and neoplastic epithelial cells so far examined. The antibody also reacts with corresponding cytokeratin polypeptides in a broad range of species including man, cow, chick, and amphibia but shows only limited reactivity with only a few rodent cytokeratins. The value of this broad-range monoclonal antibody, which apparently recognizes a stable cytokeratin determinant ubiquitous in human epithelia, for the immunohistochemical identification of epithelia and carcinomas is discussed.

Animals↗
PubMed1981

Vascular smooth muscle cells differ from other smooth muscle cells: predominance of vimentin filaments and a specific alpha-type actin.

Smooth muscle cells of the digestive, respiratory, and urogenital tracts contain desmin as their major, if not exclusive, intermediate-size filament constituent and also show a predominance of gamma-type smooth muscle actin. We have now examined smooth muscle tissue of different blood vessels (e.g., aorta, small arteries, arterioles, venules, and vena cava) from various mammals (man, cow, pig, rabbit, rat) by one- and two-dimensional gel electrophoresis of cell proteins and by immunofluorescence microscopy using antibodies to different intermediate-sized filament proteins. Intermediate-sized filaments of vascular smooth muscle cells contain abundant amounts of vimentin and little, if any, desmin. On gel electrophoresis, vascular smooth muscle vimentin appears as two isoelectric variants of apparent pI values of 5.30 and 5.29, shows the characteristic series of proteolytic fragments, and is one of the major cell proteins. Thus vimentin has been demonstrated in a smooth muscle cell present in the body. Vascular smooth muscle cells are also distinguished by the predominance of a smooth muscle-specific alpha-type actin, whereas gamma-type smooth muscle actin is present only as a minor component. It is proposed that the intermediate filament and actin composition of vascular smooth muscle cells reflects a differentiation pathway separate from that of other smooth muscle cells and may be related to special functions and pathological disorders of blood vessels.

Actins↗
PubMed1981

Antibodies to the major insoluble milk fat globule membrane-associated protein: specific location in apical regions of lactating epithelial cells.

Milk lipid globules of various species are surrounded by a membrane structure that is separated from the triglyceride core of the globule by a densely staining fuzzy coat layer of 10- to 50-nm thickness. This internal coat structure remains attached to the membrane during isolation and extraction with low- and high-salt buffers, is insoluble in nondenaturing detergents, and is enriched in an acidic glycoprotein (butyrophilin) with an apparent Mr of 67,000. Guinea pig antibodies against this protein, which show cross-reaction with the corresponding protein in some (goat) but not other (human, rat) species, have been used for localization of butyrophilin on frozen sections of various tissues from cow by immunofluorescence and electron microscopy. Significant reaction is found only in milk-secreting epithelial cells and not in other cell types of mammary gland and various epithelial tissues. In milk-secreting cells, the staining is restricted to the apical cell surface, including budding milk lipid globules, and to the periphery of the milk lipid globules contained in the alveolar lumina. These findings indicate that butyrophilin, which is constitutively secreted by surface budding in coordination with milk lipid production, is located at the apical surface and is not detected at basolateral surfaces, in endoplasmic reticulum, and in Golgi apparatus. This protein structure represents an example of a cell type-specific cytoskeletal component in a cell apex. It is suggested that this antigen provides a specific marker for the apical surface of milk-secreting cells and that butyrophilin is involved in the vectorial discharge of milk lipid globules.

Animals↗
PubMed1981

Isolation and characterization of desmosome-associated tonofilaments from rat intestinal brush border.

Epithelial cells of the small intestine, like those of other internal organs, contain intermediate-sized filaments immunologically related to epidermal prekeratin which are especially concentrated in the cell apex. Brush-order fractions were isolated from rat small intestine, and apical tonofilaments attached to desmosomal plaques and terminal web residues were prepared therefrom by extraction in high salt (1.5 M KCl) buffer and Triton X-100. The structure of these filaments was indistinguishable from that of epidermal tonofilaments and, as with epidermal prekeratin, filaments could be reconstituted from solubilized, denatured intestinal tonofilament protein. On SDS polyacrylamide gel electrophoresis of proteins of the extracted desmosome-tonofilament fractions, a number of typical brush-border proteins were absent or reduced, and enrichment of three major polypeptides of Mr 55,000, 48,000, and 40,000 was noted. On two-dimensional gel electrophoresis, the three enriched major polypeptides usually appeared as pairs of isoelectric variants, and the two smaller components (Mr 48,000, and 40,000) were relatively acidic (isoelectric pH values of 5.40 and below), compared to the Mr 55,000 protein which focused at pH values higher than 6.4. The tonofilament proteins were shown to be immunologically related to epidermal prekeratin by immunoreplica and blotting techniques using antibodies to bovine epidermal prekeratins. Similar major polypeptides were found in desmosome-attached tonofilaments from small intestine of mouse and cow. However, comparisons with epidermal tissues of cow and rat showed that all major polypeptides of intestinal tonofilaments were different from the major prekeratin polypeptides of epidermal tonofilaments. The results present the first analysis of a defined fraction of tonofilaments from a nonepidermal cell. The data indicate that structurally identical tonofilaments can be formed, in different types of cells, by different polypeptides of the cytokeratin family of proteins and that tonofilaments of various epithelia display tissue-specific patterns of their protein subunits.

Animals↗
PubMed1981

Formation of cytoskeletal elements during mouse embryogenesis. II. Epithelial differentiation and intermediate-sized filaments in early postimplantation embryos.

Following our study on the expression of cytokeratin filaments in preimplantation mouse embryos [30], we have examined the organization of cytoskeletal elements in early postimplantation embryos up to day 8 of gestation, employing electron microscopy, immunofluorescence microscopy an two-dimensional gel electrophoresis of cytoskeletal proteins labelled by incorporation of 35S-nethionine. The characteristic epithelia formed by the embryonic ectoderm and proximal (visceral) endoderm present well-developed junctional complexes and various differentiated membrane structures. Several apical differentiations of the proximal endodermal cells, such as brush border-like microvilli, the endocytotic labyrinthum, and the supranuclear vacuoles resemble the organization of epithelial cells of the ileum of neonatal mammals. Both embryonic epithelia show typical desmosomes and attached intermediate sized filaments of the cytokeratin type. Other types of intermediate-sized filaments, such as vimentin and desmin filaments, have not been detected in any of the cells of embryos of days 6 and 7, but filaments of the vimentin type can be seen, by immunofluorescence microscopy, late in day 8 in certain cells located in the forming mesoderm. Gel electrophoresis has further revealed that the major cytoskeletal proteins synthesized during days 6-8 in both extraembryonic and embryonic tissue are similar to those characteristic of preimplantation blastocysts and include a major polypeptide corresponding to cytokeratin A described in some internal organs of adult rodents. By the same techniques, synthesis of another cytoskeletal proteins vimentin, has first been found late in day 8. It is concluded that early postimplantation embryonic development, up to mesoderm formation, is characterized by the exclusive presence, in both embryonic ectoderm and proximal endoderm, of differentiated epithelial cells containing desmosome-cytokeratin filament complexes and that other types of intermediate-sized filaments are not yet expressed.

Animals↗
PubMed1977

Primary carcinoma of the appendix.

Primary adenocarcinoma of the appendix is a rare tumor. Fewer than 200 cases are on record. Correct preoperative diagnosis is virtually nonexistent. Two patients with adenocarcinoma of the appendix are described. Although appendectomy appears to be adequate treatment for carcinoid, right hemicolectomy is, in our opinion, the treatment of choice for mucinous cystadenocarcinoma, while it is mandatory in cases of adenocarcinoma of the colonic type.

Adenocarcinoma↗
PubMed1977

Analysis of the sexual dimorphism in the basioccipital portion of the dog's skull.

Sexual differences in the basioccipital portion of the skull of dogs have been described and an index is presented which reliably predicts the sex of the skull. 92 dolichocephalic skull (44 male, 48 female) from mongrel dogs were used. In the basioccipital region of the male skulls, a triangular area, which extends from the basion to a line joining the medialmost points of the two jugular foramina, appears narrow and elevated. The pharyngeal tubercle is also prominent. In female skulls the rostral angle of this triangle is wider and the triangular area seems smoother and flat. The anterior half of the female basioccipital portion is wider and smoother than in the male skull. In order to quantify the observed differences, four indices were calculated. All of the indices were statistically significant. However, only index IV could be reliably used in predicting the sex of an unknown skull: (formula: see text) was derived from breadth IV (distance between the two temporo-occipital fissures at their lateralmost points) and length II (distance between the basion and a line drawn between the two medialmost points of the jugular foramina in the midline). Values of less than 123 for male and greater than 136 for female placed the skulls in their proper sex group. Skulls that had intermediate values could be placed in correct sex grouping only in conjunction with strong observational criteria. It is suggested that in absence of such strong observational criteria these skulls may belong to immature or castrate animals.

Animals↗