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Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biopsies taken during colonoscopic examination of the human large bowel were used to examine the relationship of the commensal bacterial to the mucosal epithelial cell surface. Bacteria were seen adhering to the exposed epithelial cell surface and also to the mucus sheet. Isolation of aerobic organisms showed that Escherichia coli are closely associated with the gut wall throughout the large intestine. One strain of E. coli predominated in each biopsy, and this strain was present along the whole length of bowel. Adhesion of bacteria to the gut wall does occur in vivo and may be one of the factors involved in the ability of an organism to colonize and persist.
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PMID:Adhesion of commensal bacteria to the large intestine wall in humans. 37 6

We have studied the late changes associated with radiation enteropathy in mice over a period of 224 days following single or split doses of gamma radiation delivered to the total abdomen (TAI). We focused on the importance of adhesion formation as a cause of strictures and gut-associated deaths following TAI. Gut-associated peritoneal adhesions were found in mice 2-7 months after receiving 13.5-17.5 Gy TAI and appeared to constitute the most consistent serious late effect of irradiation. There was a good correlation between adhesion formation and death for both the single and split-doses of radiation. Adhesions primarily involved the large gut, normally near the cecum. They appeared to result from serosal breakdown and were the major cause of partial gut obstruction. Submucosal fibrosis was present but seemed to be a comparatively minor cause of strictures. Local lymphoid hyperreactivity was also seen following TAI and may have contributed to the late sequelae. The complexity of the pathogenesis of chronic radiation enteropathy was indicated by finding three successive waves of non-scheduled deaths following TAI. The first wave (28-70 days) was not related to adhesion formation and may have been due to localized failure of mucosa to regenerate after irradiation with consequent ulceration. The second wave (98-140 days) occurred over the period when adhesion formation and fibrosis were most marked. In the third wave (168-224 days), the additional complication of fluid exudation was seen. Further experimentation is obviously needed to better define the complex pathogenesis of radiation enteropathy with dose and time after radiation but our data strongly support a multifactorial causation with an important role for adhesion formation in the disease complex.
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PMID:Adhesion formation in experimental chronic radiation enteropathy. 292 Nov 72

This paper describes the relationship between primordial germ cells (p.g.cs) and the substrate over which they migrate in early embryos of the anuran amphibian Xenopus laevis. P.g.cs migrate from the embryonic gut to the dorsal body wall along the dorsal mesentery at the earliest swimming stage. Our earlier papers have described the way in which p.g.cs move in vitro. In this work we have studied the shape and cytoarchitecture of both p.g.cs and the coelomic epithelial cells (c.e.cs) over which they migrate. We have concentrated on three aspects of the morphology of these cells: first the shapes of the c.e.cs and the way that they affect the shapes of the p.g.cs; secondly the presence of adhesion plaques between the two types of cell; and thirdly the arrangement of cytoskeleton elements. The results show that c.e.cs in the dorsal mesentery are orientated cranio-caudally while those on the dorsal body wall and at the junction with the mesentery are arranged transversely, at 90 degrees to the cranio-caudal plane. P.g.cs are found in both elongated and rounded state. Where elongated, they are always in the same plane as the c.e.cs with which they are associated. The implications of this are discussed. Adhesion plaques between p.g.cs and c.e.cs are shown both by disaggregation studies and transmission electron microscope studies. Plaques are associated with the well defined microfilamentous cytoskeleton of c.e.cs, but only with a sparse array of filaments in p.g.cs. The only parts of p.g.cs where filaments are regularly found are their filopodia, which are generally seen on elongated p.g.cs in longitudinal section. We suggest on the basis of this work that p.g.cs have a dispersed cytoskeleton except during filopod extension, that they move by forming direct adhesion plaques with c.e.cs, and that c.e.cs provide a firm orientated support and possible guide to p.g.c. movement.
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PMID:Contact relations and guidance of primordial germ cells on their migratory route in embryos of Xenopus laevis. 611 67

Recirculation of mouse lymphocytes to the gut involves binding of the lymphocyte integrin alpha 4 beta 7 to the mucosal vascular addressin, MAdCAM-1. In humans, indirect evidence suggests that CD4+ T cells that express high levels of alpha 4 beta 7 migrate selectively to the gut. We now report that human adult blood CD8+ T cells and B cells, like CD4+ T cells, have heterogeneous expression of alpha 4 beta 7. In contrast, NK cells, eosinophils, and newborn blood T and B cells have relatively homogeneous expression of alpha 4 beta 7. CD4+ and CD8+ T cell expression of alpha 4 beta 7 was related to age, CD45RA expression, and integrin beta 1 (CD29) expression, suggesting that alpha 4 beta 7 expression changes after primary activation of CD4+ and CD8+ T cells in vivo. To directly determine whether human alpha 4 beta 7 mediates adhesion to MAdCAM-1, we performed in vitro adhesion assays with two alpha 4 beta 7+ human lymphoma cell lines. The results indicate that human alpha 4 beta 7 is a receptor for MAdCAM-1, whereas alpha 4 beta 1 is not. Adhesion of HUT 78 cells to MAdCAM-1 required Mn2+, whereas adhesion of RPMI 8866 cells did not, suggesting that alpha 4 beta 7 may have at least two distinct functional states. The ability of lymphocytes to bind to MAdCAM-1 and recirculate to mucosal organs is likely to be influenced both by the level of alpha 4 beta 7 expression and by the functional state of the alpha 4 beta 7 molecule.
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PMID:Expression and function of the MAdCAM-1 receptor, integrin alpha 4 beta 7, on human leukocytes. 751 18

Macrophage scavenger receptors are trimeric integral membrane glycoproteins which have been implicated in various macrophage functions including uptake of oxidized lipoprotein and the serum-dependent, divalent cation-independent adhesion of macrophages to tissue culture-treated plastic. In this study we have used a recently defined monoclonal antibody (2F8) which recognizes murine macrophage scavenger receptor, to explore its expression in lymphoid and non-lymphoid organs of the normal adult. Scavenger receptor was detected in the red pulp and marginal zone of normal adult mouse spleen, medulla of the thymus and subcapsular region of lymph nodes. Kupffer cells in the liver, alveolar macrophages in the lung and lamina propria macrophages in the gut all reacted with 2F8 monoclonal antibody. The antigen was not detected on any non-macrophage cells, with the exception of sinusoidal endothelial cells in the liver. In the spleen, lymph node and liver, scavenger receptor antigen expression was associated specifically with phagocytic cells which had taken up colloidal carbon. To examine macrophage adhesion in a context relevant to the interactions occurring within lymphoid and non-lymphoid organs, and the contribution of macrophage scavenger receptor to this adhesion, we designed an assay of macrophage adhesion to frozen tissue sections. Adhesion to most tissues was high and uniform in the absence of any chelating agents. The chelation of Ca2+ and Mg2+ revealed specific patterns of macrophage adhesion in lymphoid and non-lymphoid organs which was completely inhibited by 2F8. The ability of this antibody to block the EDTA-resistant adhesion correlated with tissue expression of the antigen in some tissues. Unlike adhesion to tissue culture-treated plastic, macrophage scavenger receptor-dependent adhesion of macrophages to frozen tissue sections did not exhibit an absolute requirement for exogenous fetal bovine serum indicating the presence of an endogenous ligand for scavenger receptor within the tissues. We propose that macrophage scavenger receptor is a candidate homing or retention molecule for macrophage localization within ligand-rich tissues.
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PMID:Murine macrophage scavenger receptor: in vivo expression and function as receptor for macrophage adhesion in lymphoid and non-lymphoid organs. 787 10

Adhesion of circulating cells to vascular endothelium occurs in the early phase of inflammation, and is mediated by specific cell adhesion molecules. Many such adhesion molecules are increased in inflamed regions of ulcerative colitis (UC) and Crohn's disease (CD) but there is limited knowledge of their expression in the uninvolved gut, adjacent to inflammation. We investigated immunohistochemically the expression of platelet endothelial cell adhesion molecule-1 (PECAM-1), intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) on resected specimens taken at a distance of 2-4 cm from the inflamed area and without histological signs of inflammation. Compared with normal gut, we found (i) a significant increase of PECAM-1-positive vessels in the mucosa of uninvolved UC (149.0 +/- 24.1 vessels/mm2 (mean +/- s.d.); normal colon = 123.1 +/- 21.6; P = 0.004); (ii) a significant decrease of ICAM-1-positive vessels in uninvolved CD (111.9 +/- 22.6 vessels/mm2; normal ileum = 136.9 +/- 27.6; P = 0.04); and (iii) a moderate but statistically insignificant increase of LFA-1-positive cells in the mucosa of uninvolved UC and Crohn's ileitis. This altered expression of cell adhesion molecules may contribute to the early lesion in inflammatory bowel disease and provide new therapeutic opportunities.
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PMID:Altered expression of cell adhesion molecules in uninvolved gut in inflammatory bowel disease. 790 Sep 41

The gastrointestinal lymphocytic system can be divided in two functional compartments, the organized lymphoid tissue, for example, the Peyer's patches, and the lymphocytes located diffusely in the mucosa, the lamina propria lymphocytes (LPL), and the intra-epithelial lymphocytes (IEL). Antigens enter the Peyer's patches as the afferent part of the GALT via specialized epithelial cells called M cells. After the initiation of the immune response by antigen processing and presentation to B and T cells in Peyer's patches, primed lymphocytes leave the mucosa via the thoracic duct. Finally they migrate back to the mucosa where they exert effector functions. Adhesion molecules, including integrins, especially alpha 4 beta 7 and alpha E beta 7 (HML-1) are involved in these homing and adhesion processes. LPL and LEL differ from peripheral blood lymphocytes in their expression of adhesion molecules and other surface and activation markers. Additionally, they exhibit functional features different from those of other lymphocyte compartments. In the mucosal immune system, plasma cells mainly secrete IgA, which is part of the specialized humoral defence in the gut.
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PMID:Special features of the intestinal lymphocytic system. 890 17

Bacteria have been associated with a wide variety of syndromes in animals and humans. These include enteropathies, urinary infections, meningitis and septicemia. Among the distinct set of tactics to prevail within the host, is the ability of bacteria to adhere to cellular targets. Adhesion to the gut by enteric bacteria occurs via several types of adhesins. During the last 15 years, much information has become available on bacterial adhesins and mechanisms governing bacteria-host interactions. Due to their location on the cell surface, establishing a carbohydrate frontier, and their inherent variability, glycosphingolipids and glycoproteins provide a wide range of binding sites for bacteria, toxins and more generally lectins. Bacterial lectins are localized either on the tip or along fimbrial filaments or on nonfimbrial structures. We examine in this short review, a collection of pathogen lectins, through their different receptor specificities. For sialic acid-binding lectins, the conformation of terminal sialic acid is essential for adhesion, whereas for other bacterial lectins, complementary sugars may be arranged in specific linear and/or branched sequences. Finally, it appears that the composition and structure of cell carbohydrates could in part explain the bacterial tropism and susceptibility or resistance of the host to enteric diseases.
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PMID:Interactions between the enteric pathogen and the host. An assortment of bacterial lectins and a set of glycoconjugate receptors. 919 3

Adhesion and subsequent colonisation are important events in the infection by Vibrio cholerae O139 Bengal. To determine in details the pathological changes in the gut mucosa, an epidemic strain of O139 Bengal was inoculated in a rabbit ileal loop model. Electron microscopic studies were done at different time intervals after inoculation of the strain to see the histological changes at the ultrastructural level. From 10 hours onwards, cellular invasive processes with presence of bacteria in the lamina propria and other associated inflammatory changes were revealed.
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PMID:Sequential changes in gut mucosa of rabbits infected with Vibrio cholerae O139 Bengal: an ultrastructural study. 936 Mar 42

Intestinal intraepithelial lymphocytes (iIEL) are primarily CD8 cells and most of them have a CD28- phenotype, the phenotype of effector cytotoxic T cells. We asked whether the predominance of CD8+CD28- T cells in the gut may result from peripheral blood T cells preferentially migrating to the iIEL compartment and adhering to iEC. Compared with CD4 cells, adhesion of resting CD8+ T cells to iEC cell lines was significantly higher. Adhesion could be blocked with a MoAb to gp180, a molecule expressed on iEC which is known to interact with CD8/lck. No significant difference in the level of adhesion was observed between CD8+CD28+ and CD8+CD28- T cells. Thus CD8 cells may preferentially migrate to the iIEL compartment, but loss of CD28 expression could occur in situ after migration. Consistent with this hypothesis, the CD8+CD28- cells became enriched after co-culturing T cells with iEC cell lines and primary iEC. Induction of the CD8+CD28- phenotype in cord blood and adult T cells was observed in co-cultures with iEC and also with mitogens and superantigens. In the latter case, CD28 down-modulation was seen specifically in the Vbeta subset targeted by the superantigen, indicating that loss of CD28 expression is a direct result of T cell receptor (TCR)-mediated stimulation. The combined results suggest that CD8+CD28- T cells are antigen experienced T cells, and that they may have a survival advantage in the presence of gut epithelial cells in vitro. This may contribute to the predominance of CD8+CD28- T cells in the iIEL compartment.
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PMID:Interactions between peripheral blood CD8 T lymphocytes and intestinal epithelial cells (iEC). 964 84


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