Search results for "Intestinal mucosa"
showing 10 items of 373 documents
Structural adaptations in the murine colon microcirculation associated with hapten-induced inflammation
2007
Objectives: Blood flowing across the vascular endothelium creates wall shear stress, dependent on flow velocity and vessel geometry, that tends to disrupt lymphocyte-endothelial cell adhesion. To identify structural adaptations during acute colitis that may facilitate transmigration, we investigated the microcirculation in a murine model of acute colitis. Methods: In trinitrobenzenesulfonic acid (TNBS)- induced acute colitis, the infiltrating cells and colonic microcirculation was investigated by cellular topographic mapping as well as corrosion casting and 3- dimensional (3D) scanning electron microscopy. Colonic blood velocimetry was performed using intravital microscopy. Results: Clinica…
In vivo histology of Barrett's esophagus and associated neoplasia by confocal laser endomicroscopy.
2006
Background & Aims: Confocal laser endomicroscopy allows subsurface analysis of the intestinal mucosa and in vivo histology during ongoing endoscopy. Here, we have applied this technique to the in vivo diagnosis of Barrett's epithelium and associated neoplasia. Methods: Fluorescein-aided endomicroscopy was performed by applying the endomicroscope over the whole columnar-lined lower esophagus. Images obtained within 1 cm of the columnar-lined lower esophagus were stored digitally and a targeted biopsy examination or endoscopic mucosal resection of the examined areas was performed. In vivo histology was compared with the histologic specimens. All digitally stored images were re-assessed by a b…
Bridging Mucosal Vessels Associated with Rhythmically Oscillating Blood Flow in Murine Colitis
2007
Oscillatory blood flow in the microcirculation is generally considered to be the result of cardiopulmonary influences or active vasomotion. In this report, we describe rhythmically oscillating blood flow in the bridging vessels of the mouse colon that appeared to be independent of known biological control mechanisms. Corrosion casting and scanning electron microscopy of the mouse colon demonstrated highly branched bridging vessels that connected the submucosal vessels with the mucosal plexus. Because of similar morphometric characteristics (19 +/- 11 microm vs. 28 +/- 16 microm), bridging arterioles and venules were distinguished by tracking fluorescent nanoparticles through the microcircul…
Echinostoma caproni: intestinal pathology in the golden hamster, a highly compatible host, and the Wistar rat, a less compatible host.
2005
The histopathological changes induced by Echinostoma caproni (Trematoda: Echinostomatidae) in a high (golden hamster) and a low compatible host (rat) were compared at 15 and 30 days post-infection. Infection of rats was characterized by a progressive increase in erosion of villi and elevated numbers of goblet cells, which could be related to the early expulsion of the parasite in a host of low compatibility. In contrast to rats, the number of goblet cell in E. caproni-infected hamsters was low, but increased numbers of neutrophils and mesenteric inflammatory cells were observed. This indicated that local inflammatory responses in hamsters were greater than in rats. An immunohistochemical st…
Morphology and chronology of ischemic mucosal changes in the small intestine
1983
The morphology and chronology of an absolute ischemia was investigated on the small intestine of man and rat. It could be shown that the morphogenesis of ischemic damage to the intestinal mucosa in man does not differ from that in the rat. However, there are crucial and in therapeutic terms significant differences in the time course of the ischemic damage to the intestinal mucosa. Whereas in the small intestine of the rat, the first appreciable alterations - detachment and disruption of the lining epithelium at the villous tip - are already to be observed after absolute ischemia lasting 15 min, in the human small intestine the same lesions only occur after 4 h. A comparable complete necrosi…
Nonceliac wheat sensitivity in the context of multiple food hypersensitivity: new data from confocal endomicroscopy.
2015
Dear Editor, We enjoyed reading the article by Fritscher-Ravens et al who showed, by confocal endomicroscopy, that candidate food antigens caused immediate duodenal mucosa damage in irritable bowel syndrome (IBS) patients with a prolonged clinical history of symptoms after meals. Their in vivo data add evidence to the relationship between IBS and food allergy and seem to reinforce our hypothesis that a percentage of “nonceliac wheat sensitive” (NCWS) -patients with an IBS-like clinical presentation could suffer from non-immunoglobulin E-mediated wheat allergy. However, we would suggest that the very high percentage of positive confocal laser endomicroscopy patients (CLE) -22 out of 36- foun…
Ischemia and post-ischemic regeneration of the small intestinal mucosa
1979
After reversible ligation of the arcade vessels of the proximal jejunum, the intestinal mucosa was investigated by light microscopic and autoradiographic methods after 15, 30, 60, 120 and 300 min of ischemia. Early ischemic damage to the mucosa (after about 15 min) is characterized by shedding of not yet irreversibly damaged enterocytes from the tips of the villi into the intestinal lumen and bleb formation starting at the base of the epithelia. This process advances from the tips to the bases of the villi with increasing duration of ischemia, and the villi are completely denuded of epithelium after ischemia lasting 2 h. Remains of the small intestinal crypts are still present at this time.…
The effects of three absorption-modifying critical excipients on the in vivo intestinal absorption of six model compounds in rats and dogs.
2018
Pharmaceutical excipients that may affect gastrointestinal (GI) drug absorption are called critical pharmaceutical excipients, or absorption-modifying excipients (AMEs) if they act by altering the integrity of the intestinal epithelial cell membrane. Some of these excipients increase intestinal permeability, and subsequently the absorption and bioavailability of the drug. This could have implications for both the assessment of bioequivalence and the efficacy of the absorption-enhancing drug delivery system. The absorption-enhancing effects of AMEs with different mechanisms (chitosan, sodium caprate, sodium dodecyl sulfate (SDS)) have previously been evaluated in the rat single-pass intestin…
Differential alterations in the small intestine epithelial cell turnover during acute and chronic infection with Echinostoma caproni (Trematoda)
2015
Background The intestinal epithelium plays a multifactorial role in mucosal defense. In this sense, augmented epithelial cell turnover appears as a potential effector mechanism for the rejection of intestinal-dwelling helminths. Methods A BrdU pulse-chase experiment was conducted to investigate the infection-induced alterations on epithelial cell kinetics in hosts of high (mouse) and low (rat) compatibility with the intestinal trematode Echinostoma caproni. Results High levels of crypt-cell proliferation and tissue hyperplasia were observed in the ileum of infected mice, coinciding with the establishment of chronic infections. In contrast, the cell migration rate was about two times higher …
Vessel painting of the microcirculation using fluorescent lipophilic tracers
2005
Flexible approaches to defining microvessel morphometry are useful in the study of both acute and chronic structural changes of the microcirculation. In this report, we examined the utility of the intravascular infusion of lipophilic carbocyanine tracers in the structural assessment of the retina, skin, lung, and colon microcirculation. The microvessel labeling technique, here termed fluorescent vessel painting, involved the intravascular injection of sulfonated lipophilic carbocyanine tracers. The utility of vessel painting in morphometry was assessed using morphometric comparisons with corrosion casting and 2-dimensional and 3-dimensional scanning electron microscopy. The comparisons demo…