Colon Tissue (colon + tissue)

Distribution by Scientific Domains

Kinds of Colon Tissue

  • human colon tissue


  • Selected Abstracts


    Nitric oxide and p53 in cancer-prone chronic inflammation and oxyradical overload disease,

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2004
    Julie E. Goodman
    Abstract Nitric oxide (NO), which is generated under chronic inflammatory conditions that predispose individuals to cancer, has paradoxical effects. NO can activate p53, which can result in anti-carcinogenic effects, or it can be mutagenic and increase cancer risk. We explored the mechanisms by which NO induced p53 activation in vitro and found that NO induced p53 accumulation and phosphorylation, particularly at ser-15, via ATM and ATR kinases, which then led to cell cycle arrest at G2/M. We next examined proteins in these pathways in both inflamed and normal human colon tissue. Inducible nitric oxide synthase (iNOS) levels and p53-P-ser15 levels were positively correlated with the degree of inflammation and with each other. Additionally, the p53 targets, HDM-2 and p21 (WAF1), were present in ulcerative colitis (UC) colon, but undetectable in normal colon, consistent with activated p53. We also found higher p53 mutant frequencies of both G:C , A:T transitions at the CpG site of codon 248 and C:G , T:A transitions at codon 247 in lesional colon tissue from UC cases versus nonlesional tissue from these cases or colon tissue from normal adult controls. Consistent with nitrosative stress and the deamination of 5-methylcytosine, p53 mutations were also detected in sporadic colon cancer tissue and were associated with iNOS activity in these tissues. These studies identified a potential mechanistic link between NO and p53 in UC and sporadic colon cancer. Environ. Mol. Mutagen. 44:3,9, 2004. Published 2004 Wiley-Liss, Inc. [source]


    Development and validation of a gas chromatography/mass spectrometry method for the metabolic profiling of human colon tissue

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 4 2009
    Mainak Mal
    In this study, a gas chromatography/mass spectrometry (GC/MS) method was developed and validated for the metabolic profiling of human colon tissue. Each colon tissue sample (20,mg) was ultra-sonicated with 1,mL of a mixture of chloroform/methanol/water in the ratio of 20:50:20 (v/v/v), followed by centrifugation, collection of supernatant, drying, removal of moisture using anhydrous toluene and finally derivatization using N -methyl- N -trifluoroacetamide (MSTFA) with 1% trimethylchlorosilane (TMCS). A volume of 1,L of the derivatized mixture was injected into the GC/MS system. A total of 53 endogenous metabolites were separated and identified in the GC/MS chromatogram, all of which were selected to evaluate the sample stability and precision of the method. Of the identified endogenous metabolites 19 belonging to diverse chemical classes and covering a wide range of the GC retention times (Rt) were selected to investigate the quantitative linearity of the method. The developed GC/MS method demonstrated good reproducibility with intra- and inter-day precision within relative standard deviation (RSD) of 15%. The metabolic profiles of the intact tissue were determined to be stable (100,,15%) for up to 90 days at ,80C. Satisfactory results were also obtained in the case of other stability-indicating studies such as freeze/thaw cycle stability, bench-top stability and autosampler stability. The developed method showed a good linear response for each of the 19 analytes tested (r2,>,0.99). Our GC/MS metabolic profiling method was successfully applied to discriminate biopsied colorectal cancer (CRC) tissue from their matched normal tissue obtained from six CRC patients using orthogonal partial least-squares discriminant analysis [two latent variables, R2Y,=,0.977 and Q2 (cumulative),=,0.877]. Copyright 2009 John Wiley & Sons, Ltd. [source]


    Aldosterone responsiveness of the epithelial sodium channel (ENaC) in colon is increased in a mouse model for Liddle's syndrome

    THE JOURNAL OF PHYSIOLOGY, Issue 2 2008
    Marko Bertog
    Liddle's syndrome is an autosomal dominant form of human hypertension, caused by gain-of-function mutations of the epithelial sodium channel (ENaC) which is expressed in aldosterone target tissues including the distal colon. We used a mouse model for Liddle's syndrome to investigate ENaC-mediated Na+ transport in late distal colon by measuring the amiloride-sensitive transepithelial short circuit current (,ISC-Ami) ex vivo. In Liddle mice maintained on a standard salt diet, ,ISC-Ami was only slightly increased but plasma aldosterone (PAldo) was severely suppressed. Liddle mice responded to a low or a high salt diet by increasing or decreasing, respectively, their PAldo and ,ISC-Ami. However, less aldosterone was required in Liddle animals to achieve similar or even higher Na+ transport rates than wild-type animals. Indeed, the ability of aldosterone to stimulate ,ISC-Ami was about threefold higher in Liddle animals than in the wild-type controls. Application of aldosterone to colon tissue in vitro confirmed that ENaC stimulation by aldosterone was not only preserved but enhanced in Liddle mice. Aldosterone-induced transcriptional up-regulation of the channel's ,- and ,-subunit (,ENaC and ,ENaC) and of the serum- and glucocorticoid-inducible kinase 1 (SGK1) was similar in colon tissue from Liddle and wild-type animals, while aldosterone had no transcriptional effect on the ,-subunit (,ENaC). Moreover, Na+ feedback regulation was largely preserved in colon tissue of Liddle animals. In conclusion, we have demonstrated that in the colon of Liddle mice, ENaC-mediated Na+ transport is enhanced with an increased responsiveness to aldosterone. This may be pathophysiologically relevant in patients with Liddle's syndrome, in particular on a high salt diet, when suppression of PAldo is likely to be insufficient to reduce Na+ absorption to an appropriate level. [source]


    Contribution of Kv4 channels toward the A-type potassium current in murine colonic myocytes

    THE JOURNAL OF PHYSIOLOGY, Issue 2 2002
    Gregory C. Amberg
    A rapidly inactivating K+ current (A-type current; IA) present in murine colonic myocytes is important in maintaining physiological patterns of slow wave electrical activity. The kinetic profile of colonic IA resembles that of Kv4-derived currents. We examined the contribution of Kv4 ,-subunits to IA in the murine colon using pharmacological, molecular and immunohistochemical approaches. The divalent cation Cd2+ decreased peak IA and shifted the voltage dependence of activation and inactivation to more depolarized potentials. Similar results were observed with La3+. Colonic IA was sensitive to low micromolar concentrations of flecainide (IC50= 11 ,M). Quantitative PCR indicated that in colonic and jejunal tissue, Kv4.3 transcripts demonstrate greater relative abundance than transcripts encoding Kv4.1 or Kv4.2. Antibodies revealed greater Kv4.3-like immunoreactivity than Kv4.2-like immunoreactivity in colonic myocytes. Kv4-like immunoreactivity was less evident in jejunal myocytes. To address this finding, we examined the expression of K+ channel-interacting proteins (KChIPs), which act as positive modulators of Kv4-mediated currents. Qualitative PCR identified transcripts encoding the four known members of the KChIP family in isolated colonic and jejunal myocytes. However, the relative abundance of KChIP transcript was 2.6-fold greater in colon tissue than in jejunum, as assessed by quantitative PCR, with KChIP1 showing predominance. This observation is in accordance with the amplitude of the A-type current present in these two tissues, where colonic myocytes possess densities twice that of jejunal myocytes. From this we conclude that Kv4.3, in association with KChIP1, is the major molecular determinant of IA in murine colonic myocytes. [source]


    HLA,B27 misfolding and the unfolded protein response augment interleukin-23 production and are associated with Th17 activation in transgenic rats

    ARTHRITIS & RHEUMATISM, Issue 9 2009
    Monica L. DeLay
    Objective To determine whether HLA,B27 misfolding and the unfolded protein response (UPR) result in cytokine dysregulation and whether this is associated with Th1 and/or Th17 activation in HLA,B27/human ,2 -microglobulin (Hu,2m),transgenic rats, an animal model of spondylarthritis. Methods Cytokine expression in lipopolysaccharide (LPS),stimulated macrophages was analyzed in the presence and absence of a UPR induced by chemical agents or by HLA,B27 up-regulation. Cytokine expression in colon tissue and in cells purified from the lamina propria was determined by real-time reverse transcription,polymerase chain reaction analysis, and differences in Th1 and Th17 CD4+ T cell populations were quantified after intracellular cytokine staining. Results Interleukin-23 (IL-23) was found to be synergistically up-regulated by LPS in macrophages undergoing a UPR induced by pharmacologic agents or by HLA,B27 misfolding. IL-23 was also increased in the colon tissue from B27/Hu,2m-transgenic rats concurrently with the development of intestinal inflammation, and IL-17, a downstream target of IL-23, exhibited robust up-regulation in a similar temporal pattern. IL-23 and IL-17 transcripts were localized to CD11+ antigen-presenting cells and CD4+ T cells, respectively, from the colonic lamina propria. Colitis was associated with a 6-fold expansion of CD4+ IL-17,expressing T cells. Conclusion The IL-23/IL-17 axis is strongly activated in the colon of B27/Hu,2m-transgenic rats with spondylarthritis-like disease. HLA,B27 misfolding and UPR activation in macrophages can result in enhanced induction of the pro-Th17 cytokine IL-23. These results suggest a possible link between HLA,B27 misfolding and immune dysregulation in this animal model, with implications for human disease. [source]


    Expression of the endogenous, nicotinic acetylcholine receptor ligand, SLURP-1, in human colon cancer

    AUTONOMIC & AUTACOID PHARMACOLOGY, Issue 4 2008
    A. Pettersson
    Summary 1,Secreted mammalian Ly-6/urokinase plasminogen activator receptor-related protein-1 (SLURP-1) is a recently discovered endogenous ligand at the ,7 subunit of the nicotinic acetylcholine receptors. Previous reports have shown that SLURP-1 is expressed in normal human keratinocytes seemingly with a pro-apoptotic function. Conversely, such expression was markedly attenuated in transformed cells and it was suggested that the molecule could convey protection against malignant transformation. 2,In this study, we demonstrated the mRNA expression (by RT-PCR) and protein expression (by Western blotting and immunocytochemistry) of SLURP-1 in the human colon cancer cell line, HT-29. 3,Furthermore, we demonstrated the expression of SLURP-1 (by immunohistochemistry) in tumour cells of human colon cancer tissue, and, to a greater extent, in immune and smooth muscle cells of adjacent, macroscopically tumour-free colon tissue. 4,The current findings suggest that SLURP-1 participates in the regulation of gut immune functions and motility, as well as possibly playing a role in colon carcinogenesis/cancer progression. [source]


    The protective and healing effects of a natural antioxidant formulation based on ubiquinol and Aloe vera against dextran sulfate-induced ulcerative colitis in rats

    BIOFACTORS, Issue 1-4 2003
    Ludmila Korkina
    Abstract Oxygen/nitrogen reactive species (ROS/RNS) are currently implicated in the pathogenesis of ulcerative colitis, drawing attention on the potential prophylactic and healing properties of antioxidants, scavengers, chelators. We evaluated the possible protective/curative effects of a natural antioxidant preparation based on Aloe vera and ubiquinol, against intestinal inflammation, lesions, and pathological alterations of the intestinal electrophysiological activity and motility, in a rat model of DSS-induced colitis. 5% dextrane sulfate (DDS) (3 days), followed by 1% DSS (4 days) was administered in drinking water. The antioxidant formulation (25 mg/kg) was delivered with a pre-treatment protocol, or simultaneously or post-colitis induction. Spontaneous and acetylcholine-stimulated electrical activity were impaired in the small intestine and in distal colon, upon exposure to DSS only. Severe inflammation occurred, with increased myeloperoxidase activity, and significant alterations of the oxidant/antioxidant status in colonic tissue and peritoneal cells. Lipoperoxidation, superoxide production, glutathione peroxidase and glutathione-S-transferase activities, and reduced glutathione content increased, whilst superoxide dismutase and catalase activities were sharply suppressed in colon tissue. ROS/RNS formation in peritoneal cells was strongly inhibited. Inflammation, electrical/mechanical impairment in the gut, and a great majority of oxidative stress parameters were improved substantially by pre-treatment with the antioxidant preparation, but not by simultaneous administration or post-treatment. [source]


    Bayesian Shrinkage Estimation of the Relative Abundance of mRNA Transcripts Using SAGE

    BIOMETRICS, Issue 3 2003
    Jeffrey S. Morris
    Summary. Serial analysis of gene expression (SAGE) is a technology for quantifying gene expression in biological tissue that yields count data that can be modeled by a multinomial distribution with two characteristics: skewness in the relative frequencies and small sample size relative to the dimension. As a result of these characteristics, a given SAGE sample may fail to capture a large number of expressed mRNA species present in the tissue. Empirical estimators of mRNA species' relative abundance effectively ignore these missing species, and as a result tend to overestimate the abundance of the scarce observed species comprising a vast majority of the total. We have developed a new Bayesian estimation procedure that quantifies our prior information about these characteristics, yielding a nonlinear shrinkage estimator with efficiency advantages over the MLE. Our prior is mixture of Dirichlets, whereby species are stochastically partitioned into abundant and scarce classes, each with its own multivariate prior. Simulation studies reveal our estimator has lower integrated mean squared error (IMSE) than the MLE for the SAGE scenarios simulated, and yields relative abundance profiles closer in Euclidean distance to the truth for all samples simulated. We apply our method to a SAGE library of normal colon tissue, and discuss its implications for assessing differential expression. [source]


    Deletion of interleukin-6 in mice with the dominant negative form of transforming growth factor , receptor II improves colitis but exacerbates autoimmune cholangitis,

    HEPATOLOGY, Issue 1 2010
    Weici Zhang
    The role of interleukin-6 (IL-6) in autoimmunity attracts attention because of the clinical usage of monoclonal antibodies to IL-6 receptor (IL-6R), designed to block IL-6 pathways. In autoimmune liver disease, activation of the hepatocyte IL-6/STAT3 (signal transducer and activator of transcription 3) pathway is associated with modulating pathology in acute liver failure, in liver regeneration, and in the murine model of concanavalin A,induced liver inflammation. We have reported that mice expressing a dominant negative form of transforming growth factor , receptor II (dnTGF,RII) under control of the CD4 promoter develop both colitis and autoimmune cholangitis with elevated serum levels of IL-6. Based on this observation, we generated IL-6,deficient mice on a dnTGF-,RII background (dnTGF,RII IL-6,/,) and examined for the presence of antimitochondrial antibodies, levels of cytokines, histopathology, and immunohistochemistry of liver and colon tissues. As expected, based on reports of the use of anti,IL-6R in inflammatory bowel disease, dnTGF,RII IL-6,/, mice manifest a dramatic improvement in their inflammatory bowel disease, including reduced diarrhea and significant reduction in intestinal lymphocytic infiltrates. Importantly, however, autoimmune cholangitis in dnTGF,RII IL-6,/, mice was significantly exacerbated, including elevated inflammatory cytokines, increased numbers of activated T cells, and worsening hepatic pathology. Conclusion: The data from these observations emphasize that there are distinct mechanisms involved in inducing pathology in inflammatory bowel disease compared to autoimmune cholangitis. These data also suggest that patients with inflammatory bowel disease may not be the best candidates for treatment with anti,IL-6R if they have accompanying autoimmune liver disease and emphasize caution for therapeutic use of anti,IL-6R antibody. HEPATOLOGY 2010 [source]


    Targeting TGF-,1 by employing a vaccine ameliorates fibrosis in a mouse model of chronic colitis

    INFLAMMATORY BOWEL DISEASES, Issue 6 2010
    Yanbing Ma MSc
    Abstract Background: Intestinal fibrosis and stricture formation are major complications of inflammatory bowel disease (IBD), for which there are currently few effective treatments. We sought to investigate whether targeting transforming growth factor-beta1 (TGF-,1), a key profibrotic mediator, with a peptide-based virus-like particle vaccine would be effective in suppressing intestinal fibrosis by using a mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced chronic colitis. Methods: The vaccine was prepared by inserting a peptide derived from mouse TGF-,1 into a carrier hepatitis B core antigen using gene recombination methods. Chronic colitis was induced in BALB/c mice by 8 weekly TNBS administrations. Mice were subcutaneously injected with vaccine, carrier, or phosphate-buffered saline (PBS) in 2 separate studies: either before or after acute inflammatory responses commenced. Results: Sera from vaccinated mice exhibited significantly elevated levels of TGF-,1-specific immunoglobulin G (IgG), which inhibited TGF-,1-induced luciferase production in mink lung epithelial cells. In the chronic colitis model, mice receiving vaccine showed improved body weight gain and significantly reduced colonic collagen deposition. Hematoxylin and eosin staining and semiquantitative scoring indicated that vaccination even ameliorated colonic inflammation. Cytokine profile analysis revealed that levels of TGF-,1, interleukin (IL)-17, and IL-23 in vaccinated mouse colon tissues were decreased, and that percentages of IL-17-expressing CD4+ lymphocytes in mesenteric lymph node cells were reduced. Furthermore, Smad3 phosphorylation, a key event in TGF-, signaling, was decreased in colonic tissue in vaccinated mice. Conclusions: This TGF-,1 peptide-based vaccine, which suppressed excessive TGF-,1 bioactivity, may prevent the development of intestinal fibrosis and associated complications, presenting a novel approach in the treatment of IBD. (Inflamm Bowel Dis 2010) [source]


    Granulocyte-macrophage colony-stimulating factor elicits bone marrow-derived cells that promote efficient colonic mucosal healing

    INFLAMMATORY BOWEL DISEASES, Issue 3 2010
    Eric Bernasconi PhD
    Abstract Background: Granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy is effective in treating some Crohn's disease (CD) patients and protects mice from colitis induced by dextran sulfate sodium (DSS) administration. However, its mechanisms of action remain elusive. We hypothesized that GM-CSF affects intestinal mucosal repair. Methods: DSS colitic mice were treated with daily pegylated GM-CSF or saline and clinical, histological, and inflammatory parameters were kinetically evaluated. Further, the role of bone marrow-derived cells in the impact of GM-CSF therapy on DSS colitis was addressed using cell transfers. Results: GM-CSF therapy reduced clinical signs of colitis and the release of inflammatory mediators. GM-CSF therapy improved mucosal repair, with faster ulcer reepithelialization, accelerated hyperproliferative response of epithelial cells in ulcer-adjacent crypts, and lower colonoscopic ulceration scores in GM-CSF-administered mice relative to untreated mice. We observed that GM-CSF-induced promotion of mucosal repair is timely associated with a reduction in neutrophil numbers and increased accumulation of CD11b+ monocytic cells in colon tissues. Importantly, transfer of splenic GM-CSF-induced CD11b+ myeloid cells into DSS-exposed mice improved colitis, and lethally irradiated GM-CSF receptor-deficient mice reconstituted with wildtype bone marrow cells were protected from DSS-induced colitis upon GM-CSF therapy. Lastly, GM-CSF-induced CD11b+ myeloid cells were shown to promote in vitro wound repair. Conclusions: Our study shows that GM-CSF-dependent stimulation of bone marrow-derived cells during DSS-induced colitis accelerates colonic tissue repair. These data provide a putative mechanism for the observed beneficial effects of GM-CSF therapy in Crohn's disease. (Inflamm Bowel Dis 2010;) [source]


    Suppression of experimental colitis in mice by CD11c+ dendritic cells

    INFLAMMATORY BOWEL DISEASES, Issue 2 2009
    Joseph E. Qualls PhD
    Abstract Background: The innate immune system serves a critical role in homeostasis of the gastrointestinal (GI) tract. Both macrophages (Ms) and dendritic cells (DCs) have been shown to have pathogenic roles in animal models of inflammatory bowel disease. However, studies by several labs have established that resident Ms and DCs within the normal GI tract maintain an immunosuppressive phenotype compared to that seen in other peripheral sites. Recent studies by our lab demonstrated that the depletion of both Ms and DCs before the initiation of dextran sodium sulfate (DSS)-induced colitis resulted in exacerbation of disease, partly caused by increased neutrophil influx. Methods/Results: In this current report, DSS-induced colitis was shown to be significantly more severe when DCs were selectively depleted in mice as indicated by changes in weight loss, stool consistency, rectal bleeding, and histopathology. In contrast to enhanced colitis in M/DC-depleted mice, which was associated with increased neutrophil influx, increased colitis in DC-depleted mice was not associated with an increase in neutrophils in the colon, as shown by CXCL1 chemokine levels and myeloperoxidase (MPO) activity. However, increased IL-6 gene and protein expression in colon tissues correlated positively with increased colitis severity in DC-depleted mice compared to colitis in DC-intact mice. Conclusions: This study demonstrates that resident DCs can suppress the severity of acute DSS colitis and that regulation of IL-6 production may contribute to DC-mediated control of intestinal inflammation. (Inflamm Bowel Dis 2008) [source]


    Dietary-feeding of grape seed extract prevents azoxymethane-induced colonic aberrant crypt foci formation in fischer 344 rats

    MOLECULAR CARCINOGENESIS, Issue 7 2010
    Balaiya Velmurugan
    Abstract Chemoprevention by dietary agents/supplements has emerged as a novel approach to control various malignancies, including colorectal cancer (CRC). This study assessed dietary grape seed extract (GSE) effectiveness in preventing azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation and associated mechanisms in Fischer 344 rats. Six-week-old rats were injected with AOM, and fed control diet or the one supplemented with 0.25% or 0.5% (w/w) GSE in pre- and post-AOM or only post-AOM experimental protocols. At 16,wk of age, rats were sacrificed and colons were evaluated for ACF formation followed by cell proliferation, apoptosis, and molecular analyses by immunohistochemistry. GSE-feeding caused strong chemopreventive efficacy against AOM-induced ACF formation in terms of up to 60% (P,<,0.001) reduction in number of ACF and 66% (P,<,0.001) reduction in crypt multiplicity. Mechanistic studies showed that GSE-feeding inhibited AOM-induced cell proliferation but enhanced apoptosis in colon including ACF, together with a strong decrease in cyclin D1, COX-2, iNOS, and survivin levels. Additional studies showed that GSE-feeding also decreased AOM-caused increase in ,-catenin and NF-,B levels in colon tissues. Compared to control animals, GSE alone treatment did not show any considerable change in these biological and molecular events in colon, and was nontoxic. Together, these findings show the chemopreventive efficacy of GSE against the early steps of colon carcinogenesis in rats via likely targeting of ,-catenin and NF-,B signaling, and suggest its potential usefulness for the prevention of human CRC. 2010 Wiley-Liss, Inc. [source]


    Molecular Fluorescence Excitation,Emission Matrices Relevant to Tissue Spectroscopy,

    PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2003
    Ralph S. DaCosta
    ABSTRACT In vivo and ex vivo studies of fluorescence from endogenous and exogenous molecules in tissues and cells are common for applications such as detection or characterization of early disease. A systematic determination of the excitation,emission matrices (EEM) of known and putative endogenous fluorophores and a number of exogenous fluorescent photodynamic therapy drugs has been performed in solution. The excitation wavelength range was 250,520 nm, with fluorescence emission spectra collected in the range 260,750 nm. In addition, EEM of intact normal and adenomatous human colon tissues are presented as an example of the relationship to the EEM of constituent fluorophores and illustrating the effects of tissue chromophore absorption. As a means to make this large quantity of spectral data generally available, an interactive database has been developed. This currently includes EEM and also absorption spectra of 35 different endogenous and exogenous fluorophores and chromophores and six photosensitizing agents. It is intended to maintain and extend this database in the public domain, accessible through the Photochemistry and Photobiology website (http://www.aspjournal.com). [source]


    Resveratrol attenuates 1,2-dimethylhydrazine (DMH) induced glycoconjugate abnormalities during various stages of colon carcinogenesis

    PHYTOTHERAPY RESEARCH, Issue 8 2009
    Murugan Sengottuvelan
    Abstract Although a myriad of health promoting effects has been attributed to resveratrol (Res) (3,5,4,-trihydroxy- trans -stilbene), a phytoalexin, the most interesting is its anticancer property. The aim of this work was to elucidate the effectiveness of Res against cellular transformation (glycoconjugate alterations) initiated by 1,2-dimethylhydrazine (DMH), a colon specific carcinogen. Group 1 were control rats, group 2 were control rats that received Res (8 mg/kg body weight orally every day), rats in groups 3,6 were treated weekly with DMH (20 mg/kg body weight, subcutaneously 15 times). In addition, groups 4,6 received Res (as in group 2) in three dietary regimens: initiation (I), post-initiation (PI) and entire period (EP). At the end of the 30 week experimental period in DMH alone exposed rats, altered levels of glycoconjugates (total hexoses, fucose, hexosamine and sialic acid) were observed in liver, intestine and colon tissues. Of the three dietary regimens of Res, the entire period supplementation significantly (p < 0.01) modulated the levels of glycoconjugates and reduced the incidence of adenoma and adenocarcinoma. These findings suggest that Res may extend its chemopreventive effect by restoring the alteration in glycoconjugates that are thought to be involved in the colonic malignant transformation process in this experimental model. Copyright 2009 John Wiley & Sons, Ltd. [source]


    Analysis of adenocarcinoma of the colon and rectum: detection of human papillomavirus (HPV) DNA by polymerase chain reaction

    COLORECTAL DISEASE, Issue 5 2005
    L. O. Prez
    Abstract Objective, The aim of the present work was to evaluate the presence of human papillomavirus genotypes in malignant and normal mucosa of the colon and rectum in order to determine if a relationship exists between HPV infection and colon neoplasms. Materials and methods, Thirty normal colon tissues and 54 sporadic adenocarcinomas were screened for HPV positivity using nested-PCR. Detection of viral types 6, 11, 16, 18, 33, 34 and 51 was performed by the LIS-SSCP (Low Ionic Strength-Single Strand Conformational Polymorphism) procedure. Results, Significant differences in high risk HPV infection were found between normal samples and adenocarcinomas (P < 0.001). Among the cases, an inverse association between HPV infection and Dukes staging was also found (P = 0.020). Finally, there was no significant association between HPV and some classical clinicopathological features, although a gradient of infection form rectum to cecum was evident. Conclusion, The present study demonstrates that HPV may infect the glandular mucosa of the colon and suggests a possible association between HPV and colorectal cancer. [source]