Browsing by Subject "Gastrointestinal tract"

Now showing 1 - 6 of 6
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    Biological and clinical review of stromal tumors in the gastrointestinal tract
    (Murcia : F. Hernández, 2000) Nishida, T.; Hirota, S.
    Submucosal tumors of the gastrointestinal tract (G1 tract) mainly consist of gastrointestinal mesenchymal tumors (GIMTs) that are distributed in the G1 tract from the esophagus through the rectum. GIMTs include myogenic tumors, neurogenic tumors and gastrointestinal stromal tumors (GISTs). The term "GIST" is now preferentially used for the tumors that express CD34 and KIT. GIMTs are composed of spindle or epithelioid cells, and 20% to 30% show malignant behavior, including peritonea1 dissemination and hematogenous metastasis. KIT expression and mutations in the c-kit gene are found only in GISTs, but not in myogenic or neurogenic tumors. Mutation in the c-kit gene is associated with aggressive features and poor prognosis, and malignant GISTs frequently have mutations in the c-kit gene. The clinicopathological features of GISTs with or without c-kit mutations are markedly different. Therefore, GIMTs may be divided into four major categories based on histochemical and genetic data: myogenic tumors; neurogenic tumors; GISTs with c-kit mutation; and GISTs without c-kit mutation. The origin of GISTs is not fully understood. However, phenotypical resemblance to the interstitial cells of Cajal (ICCs) and gain-of-function mutations in the c-kit gene may suggest origin from ICCs andlor multipotential mesenchymal cells that differentiate into ICCs.
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    Characterization of metaplastic and heterotopic epithelia in the human gastrointestinal tract by the expression pattern of acyl-CoA synthetase 5
    (Murcia : F. Hernández, 2005) Gassler, N.; Obermüller, N.; Keith, M.; Schirmacher, P.; Autschbachl, F.
    Metaplastic and heterotopic epithelia are frequently found in the human intestine. The recently cloned human acyl-CoA synthetase 5 (ACS5) is a key enzyme in providing cytosolic acyl-CoA thioesters. The aim of the study was to identify and to locate the expression of ACS5 in the gastric body and the small intestine with metaplasia or heterotopia by different methods. In the normal gastrointestinal tract, ACS5 was predominantly found in the villus epithelium of the small intestine, but not in the gastric mucosa. Of note, strong expression of ACS5 was also detectable in intestinal metaplasia of the stomach. Inversely, ACS5 expression could neither be detected in heterotopic gastric mucosa of the corpus type nor in gastric, pseudopyloric, or antral metaplasia of the small intestine. In conclusion, our data implicate that ACS5 is a suitable differentiating marker molecule in the gastrointestinal tract.
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    Diabetic state affects the innervation of gut in an animal model of human type 1 diabetes
    (Murcia : F. Hernández, 2000) Spangeus, A.; Suhr, O.; El-Salhy, M.
    Gastrointestinal symptoms in diabetic patients are commonplace, and are believed to be due, at least partly, to neuropathy of the gut. In the present study, therefore, some important neurotransmitters in the myenteric plexus were investigated in non-obese diabetic mice, an animal model of human type 1 diabetes. For this purpose, immunocytochemistry was applied on sections from antrum, duodenum and colon, subsequently quantified by computerized image analysis. Whereas the number of vasoactive intestinal peptide (VIP)-positive neurons was increased in antral myenteric ganglia of diabetic mice, there was a decreased density of nerve fibres in muscularis propria. No difference was seen in the VIP of duodenum and colon. Acetylcholinecontaining nerve fibres showed an increased volume density in muscularis propria of antrum and duodenum, but a decreased density in colon of diabetic mice, as compared with controls. There was a decreased number of neurons containing nitric oxide synthase (NOS) in myenteric ganglia of antrum and duodenum. No difference was seen in density of NOS-containing nerve fibres in muscularis propria. There was no difference regarding neuropeptide Y (NPY) and galanin between diabetic and control mice; nor was there any difference between pre-diabetic NOD mice and controls regarding all bioactive substances investigated. It is concluded that the diabetic state affects the innervation of gut in this animal model. The present findings may be of some relevance to the gastrointestinal symptoms seen in patients with diabetes.
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    Distribution of interstitial cells of Cajal in Meriones unguiculatus and alterations in the development of incomplete intestinal obstruction
    (F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2013) Bo, Wu; Li, Liu; Hengyu, Gao; Haimei, Sun; Hong, Xue; Xiaoshuang, Li; Guoquan, Zhang; Deshan, Zhou
    The interstitial cells of Cajal (ICCs) act as pacemaker cells that are involved in gastrointestinal (GI) motility disorders, although the pathogenesis of these disorders is still unclear. The GI tract of Mongolian gerbils shares similar anatomical features with that of humans, but no investigation of ICCs has been reported in the GI tracts of this animal. In the present study, we first observed the distribution and morphological features of ICCs in the Mongolian gerbil GI tract. The ICCs were mainly distributed within the smooth muscle layers (ICC-IM), the myenteric plexus (ICC-MY), the deep muscular plexus in the small intestine (ICC-DMP) and the submucosal surface of the circular muscle layer in the colon (ICC-SM). The density of the ICC-IM gradually decreased from the stomach to the colon, whereas the density of the ICC-MY gradually increased. Second, we compared differences in the ICCs between the control and obstructed intestines, and no significant difference was observed in the number of ICCs after 7 days of obstruction. However, the numbers were reduced by approximately day 14 of obstruction. The pattern of immunoreactivity also partly differed from that of the control group, i.e., a scattered and interrupted network of ICCs was often observed. Western blotting revealed that p-Kit and SCF were significantly reduced in the dilated intestines by day 14. Our results indicate that the Mongolian gerbil may be a good animal model for studying changes in ICCs that may contribute to the pathogenesis of GI motility disorders.
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    Immunolocalization of histamine H3 receptors on endocrine cells in the rat gastrointestinal tract
    (Murcia : F. Hernández, 2008) Grandi, Daniela; Shenton, Fiona C.; Chazot, Paul L.; Morini, Giuseppina
    The histamine H3 receptor (H3R) has been identified in the gastrointestinal tract of the rat by immunohistochemistry, using the first validated anti-H3 receptor antibody. Immunoreactivity to H3R was exclusively localized to the endocrine cells scattered in the gastrointestinal mucosa, with positive cells being prominently abundant in the gastric fundus, while they were rarely found in the other regions. In the fundus, positive cells were distributed in the lower half of the mucosa and their number significantly decreased after a 24 h-fasting period. Double-labeling studies were undertaken to identify the H3R-immunoreactive cell types in the fundic and antral mucosa. The H3Rimmunoreactive cells were positive for chromogranin A. In the fundus, approximately 90% of cells positive to H3R were also positive to the histamine-forming enzyme, histidine decarboxylase. None of the cells expressing H3R displayed immunoreactivity for gastrin, somatostatin or ghrelin. Location, the influence of food deprivation and colocalization with histidine decarboxylase indicate that H3R positive cells correspond to the enterochromaffin-like cells (ECL).
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    Myenteric plexus of obese diabetic mice (an animal model of human type 2 diabetes)
    (Murcia : F. Hernández, 2001) Spangeus, A.; El-Salhy, M.
    The myenteric plexus of the gastrointestinal tract was investigated in the obese diabetic mouse, an animal model of human type 2 diabetes. Sections were immunostained by the avidin-biotin complex method, using a general nerve marker, protein gene product 9.5 (PGP 9.5), as well as antibodies to several important neurotransmitters. Computerized image analysis was used for quantification. When diabetic mice were compared with controls, no difference was found in the density of PGP 9.5-immunoreactive (IR) nerve fibres in antrum, duodenum or colon. In antrum and duodenum, diabetic mice showed a decreased number of vasoactive intestinal peptide (V1P)-IR neurons in myenteric ganglia as well a decreased relative volume density in myenteric plexus (though not significantly in antrum, p=0.073). No difference was found regarding VIP-IR nerves in colon. The volume density of nitric oxide synthase (NOS)-IR nerve fibres was decreased in antrum and duodenum of diabetic mice, whereas no difference was found in colon. The density of galanin-IR neme fibres was decreased in duodenum. Whereas neuropeptide Y (NPY)- and vesicular acetylcholine transporter (VAChT)-IR nerve fibres was increased in density in colon of diabetic mice, no difference was found in antrum and duodenum. Regarding substance P, there was no difference between diabetic and control mice in antrum, duodenum or colon. The present study shows that gut innervation is affected in this animal model of human type 2 diabetes. It is possible that the present findings may have some relevance for the gastrointestinal dysfunctions seen in patients with type 2 diabetes.