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Query: UMLS:C0162871 (abdominal aortic aneurysm)
 8,664 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies on membrane receptors have been performed on the Nereis coelomocytes using various lectins. In the agglutination assay, only LCA and WGA appeared nonreactive. Fluorescent lectins showed the poor reactivity of the eleocytes and the diversity of the receptors according to the granulocyte types. Types I-granulocytes reacted only with Con A. Type II-granulocyte membrane contained mannose and galactose receptors (reactivity with Con A, PNA and SBA). The type III-granulocyte membrane revealed the presence of mannose and fucose receptors (UEA, AAA). Electron microscope investigations with HRP-DAB or mannosyl labelled Con A, RCAI and LTA have confirmed the distribution of the membrane receptors.
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PMID:Distribution and nature of membrane receptors for different plant lectins in the coelomocyte subpopulations of the Annelida Nereis diversicolor. 283 23

In order to elucidate the involvement of adhesion mechanisms in the process of megakaryocyte-dependent fibroblast growth, we applied BSA-coupled polymers of glucose, galactose, fucose, mannose, and several lectins (AAA, LCA, LTA, UEA-I) to cocultures of CD61 -positive (CD61+)/MACS-enriched megakaryocytes and human bone marrow fibroblasts. Fibroblast monocultures served as controls. After 6 days, glucose, as well as galactose-treated cultures showed a significant reduction of fibroblast growth in cocultures and fibroblast monocultures. In contrast, application of mannose caused no reducing effect on fibroblast numbers. Administration of fucose, AAA, LTA or UEA-I revealed a strong impairment of fibroblast growth in the megakaryocyte-fibroblast cocultures. Adhesion experiments using MACS-enriched, fluorescein-labelled megakaryocytes cultured in the presence of carbohydrates and lectins on a near-confluent layer of fibroblasts were additionally performed. Following fucose-BSA, alpha Fuc-1,2Gal beta-HSA or UEA-I treatment a significant reduction of megakaryocyte adhesion to the fibroblast layer could be observed. In the case of AAA a weak impairment of megakaryocyte adhesion could be noticed. Selective pretreatment of either fibroblasts or megakaryocytes with fucose-BSA or alpha Fuc-1,2Gal beta-HSA was consistent with the finding of a prominent involvement of fucosylated residues located on megakaryocytes in this interaction. In conclusion, our studies are in keeping with the assumption that fucosylated and fucose-binding structures are playing a key role in adhesion mechanisms between megakaryocytes and fibroblasts and thus influence significantly the megakaryocyte-dependent growth of bone marrow fibroblasts.
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PMID:Interactions between endogeneous lectins and fucosylated oligosaccharides in megakaryocyte-dependent fibroblast growth of the normal bone marrow. 884 95

Paneth cells are located at the base of the intestinal glands. The origin, composition, and function of these cells have not been well established. The sharing of a common pathway of development with the goblet cells has been suggested. The aim of the present study was to explore the cytochemical composition of rat Paneth cells and to discuss a possible developmental relationship between goblet and Paneth cells. Lectins (WGA, LTA, UEA-1, AAA, and HPA) were used as a precise tool for the ultrastructural localization of carbohydrates. Several procedures were performed in combination with lectin cytochemistry: beta-elimination, a reaction that specifically removes O-linked oligosaccharides (typical of mucin-type glycoproteins of goblet cells); and treatment with peptide N-glycosidase F, an enzyme that removes N-linked oligosaccharides from glycoproteins. Secretory granules of Paneth cells showed a biphasic nature composed of an electron-lucent peripheral halo containing O-linked oligosaccharides with GalNAc and GlcNAc residues and N-linked oligosaccharides with GlcNAc residues (only sparse Fuc residues were scarcely identified in O-linked oligosaccharides), and an electron-dense core containing N- and O-linked oligosaccharides with Fuc residues. Neither GlcNAc nor GalNAc was identified. The occurrence of O-linked oligosaccharides in the Paneth cells and the biphasic nature of the secretory granules, similar to that of transitional cells intermediate between mucous and serous cells of other tissues, favor the hypothesis of a common lineage for goblet and Paneth cells.
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PMID:N- and O-linked oligosaccharides in the secretory granules of rat Paneth cells: an ultrastructural cytochemical study. 901 17

The oligosaccharide sequences of glycoconjugates and the nature of the saccharide linkage were investigated in normal human testes by means of lectin histochemistry studies, at light and electron microscopy levels. Reaction to WGA was intense in the seminiferous epithelium and interstitium. MAA showed light reactivity in all cell types of the human seminiferous epithelium, the lamina propria and Leydig cells. UEA-I lectin labelled the lamina propria intensely and the seminiferous epithelium and Leydig cells slightly. A slight reaction to AAA was found in the seminiferous epithelium and in Leydig cells. ConA was labelled in Sertoli cells, germ cells and Leydig cells. The reaction to GNA lectin was similar although less intense. PNA labelling was slight in Sertoli cells, spermatogonia, and Leydig cells, and more intense in spermatocytes, spermatids and peritubular cells. Reaction to DSA was intense in the seminiferous epithelium and Leydig cells. HPA labelled all cell types in the seminiferous epithelium and Leydig cells slightly, and labelled peritubular cells intensely. SBA lectin showed a strong reaction in spermatids and a slight reaction in the lamina propria. The reactions to SNA, LTA, and DBA were negative in all testicular cell types. After beta-elimination pre-treatment, MAA, UEA-I, AAA, PNA, DSA, HPA and SBA reactions were all negative. Endo F/PNGase digestion suppressed reactivity to ConA y GNA. Staining for WGA decreased with Endo F/PNGase digestion and also after beta-elimination. Desialization increased reactivity to PNA, SBA and HPA lectins. These results indicate that the terminal sequences of oligosaccharide side-chains in spermatocytes and, principally, in spermatids are: fucose, mannose, Neu5Ac2,3Gal1,3GalNAc, Gal1,3GalNAc, Gal1,4GlcNAc, Neu5AcGalNAc and GalNAc (in O-glycosylated proteins); mannose (in N-glycosylated proteins) and GlcNAc (in both protein types). A sialic acid residue is added to galactose and GalNAc residues. Present findings also indicate that Sertoli cell glycoproteins are similar to those of spermatids, and that the terminal sugar residues in Leydig cells are GlcNAc, fucose, mannose, Neu5Ac2,3Gal1,3GalNAc, Gal1,3GalNAc, and Gal1,4GlcNAc. The lectin pattern of the lamina propria suggests the presence of GlcNAc, galactose, fucose and GalNAc.
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PMID:Lectin histochemistry of the human testis. 997 91

The oligosaccharide sequences of glycoconjugates in the normal human vas deferens and the nature of the saccharide linkage were studied by lectin histochemistry. The cytoplasm of all epithelial cell types (principal cells, basal cells, and mitochondria-rich cells) and luminal contents reacted positively with WGA, MAA, PNA, DSA, LTA, UEA-I, AAA, and ConA. The reaction was more intense in the stereocilia of principal cells. Cytoplasmic staining was diffuse except for PNA and DSA labeling which was limited to the apical cytoplasm and stereocilia of columnar cells. The cytoplasm of all cell types also reacted diffusely with HPA, although staining was weak and was not observed in the stereocilia. Positive reaction with SBA only was encountered in the stereocilia of principal cells. SNA, LTA, and DBA were unreactive. GNA-labeling showed a granular distribution in the supranuclear cytoplasm of columnar epithelial cells. Reactions with MAA, PNA, DSA, AAA, HPA and SBA disappeared after the beta-elimination reaction. Reactions with WGA and UEA-I decreased after beta-elimination or Endo-F digestion. Reactions with ConA and GNA were suppressed by Endo-F digestion. Reactions with PNA, HPA, and SBA increased after desialylation. Of all the lectins that label the luminal contents of the vas deferens, only UEA-I was not found in the luminal contents of seminiferous tubules and epididymis and, thus, this lectin would probably bind to glycoproteins secreted by the vas deferens. The chemical treatments used suggest that this secretion contains fucose residues located in both N- and O-linked oligosaccharides. The other lectins may label secreted proteins, but also structural proteins or proteins reabsorbed from the luminal fluid. The lectin- binding pattern of mitochondria-rich cells in the vas deferens differed from that found in the epididymis.
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PMID:Lectin histochemistry study in the human vas deferens. 1038 93

The objective of the present study was to characterize glycoconjugates of hamster testis in gonadally-active and -inactive states by lectin histochemical methods. Thirteen HRP- or digoxigenin-labeled lectins were used in samples obtained from fertile and photoinhibited hamsters. In gonadally-active hamsters, spermatozoa tails were stained with Con-A, HPA, PNA, UEA-I, LTA, AAA, WGA and LFA and weakly with GNA and RCA-I. Spermatozoa acrosomes were labeled with HPA, SBA, WGA and PNA. Spermatid acrosomes were labeled with SBA, RCA-I, PNA, and WGA. Staining with GNA and Con-A was found in the Golgi phase and HPA staining was found in the Golgi phase and maturated spermatids. Cytoplasm of spermatocytes was labeled with Con-A, GNA, LTA, AAA, RCA-I, HPA, WGA and LFA, whereas spermatocyte membranes were stained with Con-A, LTA and AAA. Spermatogonia were strongly labeled with Con-A and moderately labeled with AAA, WGA and LFA. Sertoli cells were positive after staining with Con-A, AAA, WGA, and LFA. The lamina propria was positive after staining with UEA-I, LTA, AAA and LFA. Leydig cells showed strong labeling with SBA, Con-A, GNA, SNA and MAA, moderate labeling with WGA, weak labeling with RCA-I, AAA and LFA. In gonadally-inactive hamsters, spermatocytes showed increased staining with HPA, PNA and AAA, whereas staining with Con-A, GNA and LTA had disappeared. Spermatogonia showed an increased labeling with AAA and WGA, but labeling with Con-A and LFA had disappeared. Sertoli cells were strongly labeled with GNA. Con-A and GNA staining was decreased in Leydig cells of gonadally-inactive hamsters but PNA and HPA staining was increased. The lamina propria in regressed testes showed intense labeling with PNA. These results suggest that histological, morphological and hormonal changes occurring in hamster testis during exposure to a short photoperiod are reflected in altered patterns of expression and distribution of N- and O-linked glycans.
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PMID:Histochemical study of glycoconjugates in active and photoperiodically-regressed testis of hamster (Mesocricetus auratus). 1283 Nov 68

Development and progression of acquired abdominal aortic aneurysms (AAAs) have been associated with different inflammatory mediators. The aim of the present study was to elucidate the topology and the potential mechanisms linking the leukotriene pathway to human AAAs. Human aneurysmal lesions were obtained from 24 patients undergoing surgery, and the intraluminal thrombus was separated from the vascular wall. Histological examination revealed major expression of the leukotriene-producing enzymes 5-lipoxygenase and LTA(4) hydrolase, as well as the two receptors for leukotriene B(4) (BLT1R and BLT2R), corresponding to neutrophils in the luminal part of the thrombus. In contrast, in the vascular wall, the leukotriene pathway mainly localized in macrophage-rich adventitial areas. Furthermore, conditioned media of the intraluminal thrombus contained significantly higher concentrations of leukotriene B(4) than that derived from the vascular wall, which were significantly correlated to other neutrophil-derived mediators, such as elastase/alpha(1)-antitrypsin complexes, myeloperoxidase, and MMP9/NGAL complexes. Finally, the neutrophil-chemotactic activity of the conditioned media from the intraluminal thrombus exhibited major inhibition by antagonists of the leukotriene B(4) receptors. Taken together, these results indicate neutrophil-derived leukotriene B(4) as a major neutrophil chemotactic factor released from the intraluminal thrombus of human AAAs and suggest that targeting BLT receptors may represent a potential medical therapeutic strategy in the prevention of AAA progression in humans.
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PMID:Differential inflammatory activity across human abdominal aortic aneurysms reveals neutrophil-derived leukotriene B4 as a major chemotactic factor released from the intraluminal thrombus. 1913 15

Leukotriene B(4) (LTB(4)) is a pro-inflammatory lipid mediator generated by the enzymes 5-lipoxygenase (5-LO) and LTA(4)-hydrolase. LTB(4) signals primarily through its G protein-coupled receptor BLT1, which is highly expressed on specific leukocyte subsets. Recent genetic studies in humans as well as knockout studies in mice have implicated the leukotriene synthesis pathway in several vascular pathologies. Here we tested the hypothesis that pharmacological inhibition of BLT1 diminishes abdominal aortic aneurysm (AAA) formation, a major complication associated with atherosclerotic vascular disease. Chow-fed Apoe(-/-) mice were treated with a 4-week infusion of Angiotensin II (AngII, 1000 ng/(kg min)) beginning at 10 weeks of age, in a well-established murine AAA model. Administration of the selective BLT1 antagonist CP-105,696 beginning simultaneously with AngII infusion reduced the incidence of AAA formation from 82% to 40% (p<0.05). There was a concordant reduction in maximal aortic diameter from 2.35 mm to 1.56 mm (p<0.05). While administration of the antagonist on day 14 after the onset of AngII infusion diminished lesional macrophage accumulation, it did not significantly alter the size of AAA by day 42. Thus, pharmacological inhibition of BLT1 may ultimately hold clinical promise, but early intervention may be critical.
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PMID:Pharmacological inhibition of BLT1 diminishes early abdominal aneurysm formation. 2003 40

Leukotrienes (LTs) derived from 5-lipoxygenase (5-LO) activity are most widely known for their actions during acute inflammation and asthma. 5-LO/LT pathway involvement in cardiovascular disease (CVD) pathogenesis has come to the forefront based on provocative human genetic/population and animal studies leading to the hypothesis that this pathway promotes atherosclerosis, abdominal aortic aneurysm, and myocardial infarction/reperfusion injury via increased leucocyte chemotaxis, vascular inflammation and enhanced permeability, and subsequent tissue/matrix degeneration. A series of pre-clinical studies have tested this hypothesis by means of genetic or pharmacological inhibition of either the LT biosynthesis axis (5-LO, 5-LO-activating protein, LTA(4) hydrolase, LTC(4) synthase) or the cognate LT receptors. Here, we summarize, compare, and analyse these animal studies and relate their findings to human disease pathogenesis. We draw a complex picture of 5-LO/LT participation in cardiovascular disorders, which is further complicated by marked differences between species. Moreover, we discuss how the cytokine footprint of the respective pathological conditions determines the expression level and hence, the contribution of components of the pathway to the overall disease state. Current knowledge implies a role for 5-LO and LTs during the early/acute phase of CVD, but our understanding of a putative 5-LO/LT involvement in more advanced stages of CVD is limited, thereby preventing simple extrapolation of findings from animal studies to humans.
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PMID:The 5-lipoxygenase/leukotriene pathway in preclinical models of cardiovascular disease. 2009 52

Histochemical, lectin-histochemical, and immunohistochemical analyses were performed on parietal cells of the greater horseshoe bat, Rhinolophus ferrumequinum, to clarify the composition and distribution of oligosaccharide chains in the beta-subunit of the protonic pump H(+),K(+)-ATPase. PAS, Alcian Blue (pH 2.5) and Alcian Blue (pH 1.0) stainings detected only neutral glycoconjugates. Lectin-binding analyses included LTA, UEA-I, ConA, SBA, BSI-B4, AAA, DBA, PNA, and WGA. WGA-and PNA-bindings were also tested after beta-elimination to detect O-linked glycans. Parietal cells were negative for binding to LTA and UEA-I, and to PNA and WGA after beta-elimination, indicating the lack of (1,2) fucosylated residues and of N-linked glycans, respectively. Immunohistochemical tests with anti-alpha- and anti-beta-H(+),K(+)-ATPase were positive. Two alternative patterns of glycoconjugate distribution were found, i.e. a perinuclear and a diffuse one, indicating localization in the intracellular canaliculus and in the tubulovesicular system of the parietal cells, respectively. Both the subunits of the H(+),K(+)-ATPase and the galactosyl/galactosaminyl residues were co-distributed in both the perinuclear and the diffuse patterns, suggesting that the residues are part of the protonic pump. Glycosyl/glycosaminyl and mannosyl groups were concentrated in the tubulovesicular system, and fucosylated residues were found almost exclusively in the intracellular canaliculi; thus they are probably not included in the oligosaccharide chains of beta-H(+),K(+)-ATPase. These findings indicate that the oligosaccharide chains linked to the beta-H(+),K(+)-ATPase subunit in R. ferrumequinum have distinct features compared to the other mammals studied and confirms the taxon specificity of the chains in the proton pump.
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PMID:Co-distribution of glycoconjugates and H(+), K(+)-ATPase in the parietal cells of the greater horseshoe bat, Rhinolophus ferrumequinum (Schreber, 1774). 2044 91


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