Intestinal Wall (intestinal + wall)

Distribution by Scientific Domains

Selected Abstracts

Caenorhabditis elegans expresses three functional profilins in a tissue-specific manner

CYTOSKELETON, Issue 1 2006
D. Polet
Abstract Profilins are actin binding proteins, which also interact with polyphosphoinositides and proline-rich ligands. On the basis of the genome sequence, three diverse profilin homologues (PFN) are predicted to exist in Caenorhabditis elegans. We show that all three isoforms PFN-1, PFN-2, and PFN-3 are expressed in vivo and biochemical studies indicate they bind actin and influence actin dynamics in a similar manner. In addition, they bind poly(L -proline) and phosphatidylinositol 4,5-bisphosphate micelles. PFN-1 is essential whereas PFN-2 and PFN-3 are nonessential. Immunostainings revealed different expression patterns for the profilin isoforms. In embryos, PFN-1 localizes in the cytoplasm and to the cell,cell contacts at the early stages, and in the nerve ring during later stages. During late embryogenesis, expression of PFN-3 was specifically detected in body wall muscle cells. In adult worms, PFN-1 is expressed in the neurons, the vulva, and the somatic gonad, PFN-2 in the intestinal wall, the spermatheca, and the pharynx, and PFN-3 localizes in a striking dot-like fashion in body wall muscle. Thus the model organism Caenorhabditis elegans expresses three profilin isoforms and is the first invertebrate animal with tissue-specific profilin expression. Cell Motil. Cytoskeleton, 2006.© 2005 Wiley-Liss, Inc. [source]

Acute intestinal obstruction due to intramural haemorrhage in small intestine in a patient with severe haemophilia A and inhibitor

Khaled M. A. Ramadan
Abstract:, Patients with severe haemophilia A usually present with joint, gastrointestinal and urinary tract haemorrhage. Bleeding elsewhere is often precipitated by pre-existing pathology or trauma. We report a patient with severe haemophilia A, who presented with symptoms of acute intestinal obstruction. He has a factor VIII inhibitor and receives recombinant factor VIIa on demand at home. The CT scan of abdomen showed dilated small intestine with fluid filled loops and a long segment in the jejunum with marked transmural thickening. There was no other pathology in the small intestine. These appearances were consistent with intramural haemorrhage in the small intestine as the cause of acute obstruction. He was managed conservatively with recombinant factor VIIa and this resulted in resolution of his symptoms. This case highlights an unusual presentation of bleeding in a haemophilia patient. Intestinal obstruction due to haemorrhage in the small intestinal wall is extremely rare and only previously reported in a few haemophilia patients. It also highlights the effectiveness of conservative management with recombinant factor VIIa as opposed to immediate exploratory surgery. [source]

Induction of colonic transmural inflammation by bacteroides fragilis.

Implication of Matrix Metalloproteinases
Abstract Background: Commensal bacteria are implicated in the pathophysiology of intestinal inflammation, but the precise pathogenetic mechanisms are not known. We hypothesized that Bacteroides fragilis -produced metalloproteinases (MMPs) are responsible for bacterial migration through the intestinal wall and transmural inflammation. Aim: To investigate the role of bacterial-MMP activity in an experimental model of colitis induced by the intramural injection of bacteria. Methods: Suspensions of viable B. fragilis or Escherichia coli were injected into the colonic wall, and the effect of the MMP inhibitor (phenantroline) on histologic lesion scores was tested. MMP activity in bacterial suspensions was measured by azocoll assay. Results: The inoculation with B. fragilis induced chronic inflammatory lesions that were preferentially located in the subserosa, whereas inoculation with E. coli induced acute-type inflammatory reactions, evenly distributed in both the submucosa and subserosa. Treatment with phenantroline significantly decreased subserosal lesion scores in rats inoculated with B. fragilis, but not in rats inoculated with E. coli. Bacterial suspensions of B. fragilis showed MMP activity, but E. coli suspensions did not. Sonication of B. fragilis reduced MMP activity and virulence to induce serosal lesions. Conclusion: Our data suggest that bacterial MMPs may be implicated in the serosal migration of B. fragilis and in the induction of transmural inflammation. [source]

Gadolinium-enhanced magnetic resonance imaging.

A useful radiological tool in diagnosing pediatric IBD
Abstract Background Recent advances in gadolinium-enhanced magnetic resonance imaging (G-MRI) have been developed to enhance the resolution of the intestinal mucosa and facilitate the differentiation of ulcerative colitis (UC) from Crohn's disease (CD). The objective of this study is to apply this technology in Pediatrics. Methods A G-MRI was performed on 58 consecutive children with suspected IBD between 1999 and 2002 using intravenous gadolinium, fat suppression, and respiration-suspended sequences to enhance the resolution of the intestinal wall. The sensitivity and specificity in diagnosing either UC or CD was determined by comparing the G-MRI to the established histologic diagnosis. Results G-MRI confirmed the diagnosis of either CD (21) or UC (7) with a sensitivity and specificity of 96% and 92%, respectively. Among the 21 patients with CD, 14 showed proximal small bowel involvement by G-MRI. In total, 17 patients were diagnosed with indeterminate colitis (IC) based on histologic criteria alone, and among these patients, G-MRI had a significantly lower non-classification rate (P < 0.02). In comparison, endoscopy was less sensitive (57%), but more specific (100%) than either histology or G-MRI in diagnosing IBD. G-MRI also showed a strong concordance with computed tomography in diagnosing CD (P = 0.001). Conclusion G-MRI is a both a sensitive and specific radiologic tool in diagnosing pediatric IBD. In patients with CD, G-MRI may be useful in identifying proximal small bowel involvement. Longitudinal follow-up studies are needed in those patients diagnosed with IC to determine the predictive value of G-MRI testing. [source]

Expression and enzyme activity of ,(1,6)fucosyltransferase in human colorectal cancer

Laura Muinelo-Romay
Abstract Changes in enzyme activity and the expression levels of ,(1,6)fucosyltransferase [,(1,6)FT] have been reported in certain types of malignant transformations. To develop a better understanding of the role of ,(1,6)FT in human colorectal carcinoma (CRC), we analysed the enzyme activity in healthy and tumour tissues. ,(1,6)FT activity was considerably higher in tumour tissue than in healthy tissue and was related to gender, lymph node metastasis, type of growth and tumour stage. We also observed a significant increase in the ,(1,6)FT expression in tumour tissues as compared to healthy and transitional tissues, inflammatory lesions and adenomas. The immunohistochemical expression in tumour tissues was correlated with the degree of infiltration through the intestinal wall. Finally, a statistical correlation was found between enzyme activity and expression obtained by Western blot in colorectal tumours when compared in the same patient. All these findings demonstrate an alteration of ,(1,6)FT activity and expression in CRC. © 2008 Wiley-Liss, Inc. [source]

Endotoxin translocation in two models of experimental acute pancreatitis

C. Vasilescu
Abstract To test the hypothesis that endotoxin is absorbed from the gut into the circulation in rats with experimental acute pancreatitis we studied two different animal models. In the first model necrotizing pancreatitis was induced by the ligation of the disatl bilio-pancreatic duct while in the second, experimental oedematous acute pancreatitis was induced by subcutaneous injections of caerulein. In both experiments, in the colon of rats with acute pancreatitis endotoxin from Salmonella abortus equi was injected. Endotoxin was detected by immunohistochemistry in peripheral organs with specific antibodies. The endotoxin was found only in rats with both acute pancreatitis and endotoxin injected into the colon and not in the control groups. The distribution of endotoxin in liver at 3 and 5 days was predominantly at hepatocytes level around terminal hepatic venules, while in lung a scattered diffuse pattern at the level of alveolar macrophages was identified. A positive staining was observed after 12 hours in the liver, lung, colon and mesenteric lymph nodes of rats with both caerulein pancreatitis and endotoxin injected into the colon. We conclude that the experimental acute pancreatitis leads to early endotoxin translocation from the gut lumen in the intestinal wall and consequent access of gut-derived endotoxin to the mesenteric lymph nodes, liver and lung. [source]

Myxobolus erythrophthalmi sp. n. and Myxobolus shaharomae sp. n. (Myxozoa: Myxobolidae) from the internal organs of rudd, Scardinius erythrophthalmus (L.), and bleak, Alburnus alburnus (L.)

K Molnár
Abstract During a survey of myxosporean parasites of cyprinid fish in Hungary, infections caused by unknown Myxobolus spp. were found in the internal organs of rudd, Scardinius erythrophthalmus, and bleak, Alburnus alburnus. Small plasmodia developed in blood vessels of the kidney, liver, testes and intestinal wall. The parasites were studied on the basis of spore morphology and by histological and molecular methods. In most cases, plasmodia were surrounded by host tissue without a host reaction; however, in advanced cases, a connective tissue capsule was seen around plasmodia. Spores collected from the two fish species differed from each other and from the known Myxobolus spp. both in their morphology and 18S rDNA sequences. The two species, described as M. erythrophthalmi sp. n. from rudd and M. shaharomae sp. n. from bleak, are characterized by a specific histotropism to blood vessels, while the organ specificity involves the kidney and for the latter species, most internal organs. [source]

Histopathology, immunohistochemistry and ultrastructure of the intestine of Leuciscus cephalus (L.) naturally infected with Pomphorhynchus laevis (Acanthocephala)

B S Dezfuli
The histopathology, immunohistochemistry and ultrastructure of the alimentary canal of chub, Leuciscus cephalus (L.), from the River Brenta, naturally infected with the acanthocephalan Pomphorhynchus laevis Müller, 1776, was studied and described. Of 62 chub examined, 54 (87%) were infected with P. laevis; the intensity of infection ranged from five to 130 parasites per host, and a density of 8 P. laevis per cm2 was common. Examination of histological material of infected chub revealed that both male and female acanthocephalans deeply penetrated all layers of the gut wall by means of their slender neck, bulb and proboscis. As a result, a capsule was formed around the bulb and proboscis on the external surface of the host intestine. In parasitized chub, four main types of reaction against the body of the acanthocephalan were recognized. Pomphorhynchus laevis caused local damage to the intestinal wall, eliciting catarrhal-erosive enteritis in the lumen and a fibroblastic-collagenous and fibro-epithelioid encapsulation in its thickness with tissue zonation according to the depth of parasite penetration. Furthermore, eosinophilic granular cells (EGC) within the inflammatory tissue were identified by immunohistochemical methods and transmission electron microscopy. [source]

Synthesis and biological evaluation of [carboxyl - 11C]eprosartan

Ola Ĺberg
Abstract Essential hypertension occurs in approximately 25% of the adult population and one cause of hypertension is primary aldosteronism. Targeting the angiotensin II AT1 receptor using PET and an appropriate tracer may offer a diagnostic method for adrenocortical tissue. This report describes the synthesis of the selective AT1 receptor antagonist [carboxyl - 11C]eprosartan 10, 4-[2-butyl-5-((E)-2-carboxy-3-thiophen-2-yl-propenyl)-imidazol-1-ylmethyl]-[carboxyl - 11C]benzoic acid, and its precursor (E)-3-[2-butyl-3-(4-iodo-benzyl)-3H -imidazol-4-yl]-2-thiophen-2-ylmethyl-acrylic acid 9. 11C-carboxylation of the iodobenzyl moiety was performed using a palladium-mediated reaction with [11C]carbon monoxide in the presence of tetra- n -butyl-ammonium hydroxide in a micro-autoclave using a temperature gradient from 25 to 140°C over 5,min. After purification by semipreparative HPLC, [carboxyl - 11C]eprosartan 10 was obtained in 37,54% decay-corrected radiochemical yield (from [11C]carbon monoxide) with a radiochemical purity >95% within 35,min of the end of bombardment (EOB). A 5-µAh bombardment gave 2.04,GBq of 10 (50% rcy from [11C]carbon monoxide) with a specific activity of 160,GBq,µmol,1 at 34,min after EOB. Frozen-section autoradiography shows specific binding in kidney, lung and adrenal cortex. In vivo experiments in rats demonstrate a high accumulation in kidney, liver and intestinal wall. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Isolation and characterization of metabolites of centpropazine in rat liver, intestine, and red blood cell homogenates

Bhattaram V. Atul
Abstract The potential sites for metabolism of centpropazine (CPZ) (an antidepressant) were evaluated in male Sprague-Dawley rats. The isolation and identification of the major metabolites formed in the presence of rat liver S9 fraction, intestine, and red blood cells under aerobic conditions were performed using high-performance liquid chromatography and electrospray ionization mass spectrometry. CPZ was found to be extensively metabolized to seven possible metabolites by liver S9 fraction in the presence of a nicotinamide adenine dinucleotide phosphate generating system at 37°C. Both intestinal wall and red blood cells were also found to metabolize the compound. This metabolite structure was confirmed by comparison with that of its synthetic standard. The drug was stable in intestinal contents. On the basis of our finding, we propose the in vitro metabolic pathways for CPZ. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:2067,2075, 2002 [source]

Ultrasonographic evaluation of the thickness of the small intestinal wall in dogs with inflammatory bowel disease

H. Rudorf
Objectives: To establish whether the intestinal wall thickness, as measured ultrasonographically, is significantly increased in dogs with inflammatory bowel disease (IBD). The results would provide the information necessary to decide whether measurement of ultrasonographic wall thickness can predict IBD in dogs. Methods: The intestinal wall thickness of 75 dogs with idiopathic IBD, as measured by ultrasonography, was compared with recently published normal values. IBD was either confirmed histologically (n=54) or suspected (n=21). In all cases there was a positive response to immunosuppressive treatment. Results: A positive association between intestinal wall thickness in dogs and either the histological diagnosis or the response to treatment was not found. Ultrasonographic intestinal wall measurements do not appear to be able to establish a diagnosis of intestinal inflammation and may result in a false negative diagnosis in cases of IBD. Clinical Significance: The same ,grey zone' of between 4 and 6 mm used in humans can be used in the canine duodenum to distinguish the normal range, reserving the term ,abnormal' for an intestinal measurement greater than 6 mm in the duodenum and greater than 4·7 mm in the jejunum. [source]

Electrochemical detection of neurotransmitters in the gut wall

P. Vanden Berghe
Abstract, Cells interact with each other by releasing signalling molecules, which can activate or inactivate target cells. In order to understand how coordination results from this communication, accurate measurements of these signalling molecules are prerequisite. Several different techniques exist to monitor and quantify these compounds, including enzymatic and histochemical assays, electrophysiological and optical recordings. However, there has been little use of electrochemical recordings in gastroenterological research, although these are very fast and sensitive. Electrochemical techniques rely on the simple fact that electroactive molecules can be oxidized at a given potential. The currents, elicited by the oxidation, are directly proportional to the concentration of the compound. In the current issue of Neurogastroenterology and Motility, electrochemical detection was successfully applied to measure nitric oxide (NO) from intestinal preparations. Although there are some important specificity, timing and spatial aspects to consider, this direct NO-probing technique is definitely a great asset to the field of gastrointestinal research and advances our understanding of NO signalling in the intestinal wall. [source]