Browsing by Subject "Glycocalix"

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    An electron microscopic study of Helicobacter pylori in the surface mucous gel layer
    (Murcia : F. Hernández, 1998) Ogata, M.; Araki, K.; Ogata, T.
    This study describes the distribution of spiral and coccoid forms of Helicobacter (H. ) pylori within the surface mucous gel layer (SMGL) on human gastric mucosae. Gastric mucosae infected with H. pylori were obtained from surgically removed stomachs of 14 cases of gastric cancer. The glycocalyx of the spiral and coccoid forms of H. pylori was examined for specific lectin labeling. Coccoid forms were identified in 11 of these cases (78.6%). The SMGL, which was from 50 to 100 pm in thickness, contained H. pylori throughout its entire thickness. Variously-sized vacuole-like clear areas were present near H. pylori. The glycocalyx on both the spiral and coccoid forms was similar in its staining with the 8 types of lectins tested. However, the staining pattern of the lectins varied among different samples. The numerous fibrillae-like filaments radiated from the surface of the bacteria and appeared to link the bacteria to the surface mucous cells or the surrounding mucus. These fibrillae-like filaments were not specifically stained by the lectin reactions, suggesting absence of sugar molecules.
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    Scanning electron microscopy study of small bowel biopsies in chronic diarrhoea in chlldhood
    (Murcia : F. Hernández, 1991) Pesce, Fernando; Romano, Paola; Barabino, Arrigo; Savioli, Cesarina; Callea, Francesco
    In thi, study wc have compared the results ot Scanning Electron Microscopy (SEM) with Light- and Stereomicroscopy in a series of small bowel biop\ies in children. In 9 cases displaying features of partial or wbtotal atrophy, Light and Dissecting-Microscopy yiclded similar results. The distinction between coeliac and noncoeliac chronic diari-hoen was only possible on cliiiical grounds, and by the iininunological detection of specific antibodies. On SEM however coeliac patients showed characteristic alterations consisting of: absence of villi: prominent crypt outlets resulting in a mosaic appearance: concentric furrows running al1 around the openings; and downy brush feature at higti power. The microvilli were loosely distributed and had an irregular pleomorphic outline; they often displayed a druinstick swelling of tlic tip and were bent. In contra5t. non-coeliac chronic diarrhoea cases were characterized bv a thick mucous layer on the mucosa1 surface, that made it impossible to visualize further chan~es. U Peculiar \iascular changes in Iymphangiectasia and in sickle beta thalasseinia could be detected only by Liglit Microscopy. In addition, in the lymphangiectasia ca\e SEM allowed the detection of enteroadherent bacteria: and in the lambliasi, case, of pseudomembi-rine\. Absence of glycocalyx was noted both in controls and in patients. The results of this study point to a diagnostic utility of SEM particularly in the differential diagnosis of chronic diarrhoea; moreover they suggest tliat enteroadherent bacteria may not be pathogenic and that the absence of glycocalyx is not specific for allergic enteropathy as previously claimed.