Browsing by Subject "Gastric mucosa"

Now showing 1 - 5 of 5
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    Differential distribution of transforming growth factor beta and receptors in the hyper or hypoproliferative gastric mucosa of developing and adult rats
    (Murcia : F. Hernández, 2007) Alvares, E.P.; Jordão, L.R.; Gama, P.
    Transforming growth factor ß (TGFß) isoforms are known for their antiproliferative effect on epithelial cells in vitro, but the role of each isoform in vivo is poorly understood, mainly when non-pathological conditions are considered. We correlated the presence and distribution of isoforms and receptors to physiological changes in gastric cell proliferation in developing and adult rats. We used fasting to induce either the hyper (14-day-old pups) or hypoproliferation (60-day-old rats) of the gastric epithelium. In 14-d-old pups fasting reduced only TGFß3 labelling in the gland. Conversely, in 60-d-old rats there was an increase of TGFß1 and TGFß3 immunolabelled cells. Receptors were detected at both ages. Therefore, the changes induced by fasting in the constitutive TGFß expression can be correlated to the differential epithelial proliferation in the stomach of developing and adult rats. These results suggest that one of the functional roles of TGFß in vivo is to locally regulate cell proliferation.
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    Distribution of the carcinoembryonic antigen CEA in gastric lesions. lmmunohistochemical testing of three novel monoclonal antibodies
    (Murcia : F. Hernández, 1990) Berner, Aasmund; Bormer, Ole; Marton, Per F.; Nesland, Jahn M.
    Three mouse monoclonal antibodies MAB (CEA 12-140-1, -2 and -4) raised against different CEA epitopes were tested in 32 gastric adenocarcinomas (18 intestinal type and 14 diffuse type) and 34 gastric lesions with severe and moderate dysplasia. The MAB stained 1 3 , l l and 13 out of the 14 diffuse carcinomas and 11,13 and 13 out of the 18 intestinal carcinomas. The dysplastic lesions were positive in 9, 9 and 6 out of 34 cases. Less than half of the cases with metaplastic epithelium adjacent to the carcinomas were also positive for MAB. All MAB showed the same pattern of reactivity without cross-reactivity. Their cumulative staining rate corresponded closely to that of polyclonal CEA antiserum, but the MAB stained more cells. The reactivity was confined to intracytoplasmic vacuoles in diffuse carcinomas and appeared diffusely in the cytoplasm or limited to the cell membrane in intestinal type of carcinomas. Our findings do not indicate CEA to be a reliable marker for malignant transformation in gastric mucosa.
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    Endocrine cells of the gastric mucosa of Rana temporaria L.
    (Murcia : F. Hernández, 1987) Díaz de Rada, O.; Sesma, P.; Vazquez, J.J.
    The endocrine cells of the gastric mucosa of Rana temporaria have been studied according to the ultrastructure, the staining properties of the granules with Masson Fontana's and Grimelius' silver methods, silver impregnation of Davenport on deplasticised semithin sections and immunocytochemical techniques. Seven different types of endocrine cells have been described. Six were regarded as belonging to known types: G, A, EC, ECL, D and P cells. One type was considered as unclassifiable.
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    Leptin secretion by white adipose tissue and gastric mucosa
    (Murcia : F. Hernández, 2007) Cammisotto, P.G.; Bendayan, M.
    Leptin is a hormone that plays a central role in the regulation of food intake and energy expenditure. Originally discovered in mature white adipocytes, it was subsequently isolated from the gastric mucosa. This tissue contains a large number of epithelial endocrine and exocrine cells secreting leptin in the blood stream and in the gastric lumen, respectively. Light and electron microscopy have shown that adipocytes and gastric epithelial cells contain leptin along their rough endoplasmic reticulum-Golgi-granules secretory pathway. Both tissues synthesize a soluble form of the leptin receptor that is secreted bound to leptin in the blood and into the gastric juice. This soluble receptor protect leptin and enhances its half-life. Despite the similarities in the mechanisms of leptin secretion by adipocytes and gastric epithelial cells, they are in fact radically different. In gastric cells leptin follows a rapid regulated secretion pathway whereas adipocytes secrete leptin in a constitutive slow fashion. These differences can be explained by the specific roles play by leptin originating from these two different tissues. Gastric leptin is involved in the short-term regulation of digestion, including delay of gastric emptying, absorption of nutrients by the intestinal wall and secretion of gastric, intestinal and pancreatic hormones. On the other hand, leptin secreted by white adipocytes acts primarily on the hypothalamus for the long-term regulation of food intake. Therefore, the coordination of adipose and gastric leptins ensures the proper management of food processing and energy storage.
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    lmmunohistochemical detection of metallothionein in carcinomatous and normal human gastric mucosa
    (Murcia : F. Hernández, 2000) Tuccari, G.; Giuffre, G.; Arena, F.; Barresi, G.
    Utilising a specific monoclonal mouse antibody (E9), metallothionein (MT) expression has been immunohistochemically investigated in 112 formalin-fixed paraffin-embedded surgical gastric samples, 38 of which were early carcinomas (EGC) and 74 advanced ones (AGC); clinico-pathological details and follow-up data (ranging from 3 to 197 months, mean 60.5 months) were available. Eighty-nine portions of gastric mucosa adjacent to examined carcinomas (transitional mucosa) were also analysed; in addition, 22 biopsies of normal gastric mucosa were studied as tissue control. The MT immunoreactivity was evaluated by staining and intensity-distribution scores. A various MT positivity was appreciable in the cytoplasm and nucleus of antrum or body gastric epithelia1 cells in 100% of normal control biopsies. 751112 (67%) gastric carcinomas showed MT immunoreactivity with a significant lower expression in AGC. No relationships were encountered between MT immunostaining and clinico-pathological data; in addition, no difference in the Kaplan-Meier survival curves of patients with various MT expression was achieved. When the transitional mucosa was examined, 84/89 (94%) samples were stained although the immunoreaction was not always concordant with that encountered in adjacent carcinomatous elements. The significant statistical decrease of MT scores observed by us moving from normal to neoplastic gastric mucosa allows us to exclude the hypothesis of an overexpression of MT in gastric carcinomas.