Rectal Mucosal Biopsies Research Articles

Differences in microbial signatures between rectal mucosal biopsies and rectal swabs

There is growing evidence the microbiota of the large bowel may influence the risk of developing colorectal cancer as well as other diseases including type-1 diabetes, inflammatory bowel diseases and irritable bowel syndrome. Current sampling methods to obtain microbial specimens, such as feces and mucosal biopsies, are inconvenient and unappealing to patients. Obtaining samples through rectal swabs could prove to be a quicker and relatively easier method, but it is unclear if swabs are an adequate substitute. We compared bacterial diversity and composition from rectal swabs and rectal mucosal biopsies in order to examine the viability of rectal swabs as an alternative to biopsies. Paired rectal swabs and mucosal biopsy samples were collected in un-prepped participants (n = 11) and microbial diversity was characterized by Terminal Restriction Fragment Length polymorphism (T-RFLP) analysis and quantitative polymerase chain reaction (qPCR) of the 16S rRNA gene. Microbial community composition from swab samples was different from rectal mucosal biopsies (p = 0.001). Overall the bacterial diversity was higher in swab samples than in biopsies as assessed by diversity indexes such as: richness (p = 0.01), evenness (p = 0.06) and Shannon’s diversity (p = 0.04). Analysis of specific bacterial groups by qPCR showed higher copy number of Lactobacillus (p < 0.0001) and Eubacteria (p = 0.0003) in swab samples compared with biopsies. Our findings suggest that rectal swabs and rectal mucosal samples provide different views of the microbiota in the large intestine.

Response of glutathioneS-transferase Pi (GSTP1) to neoadjuvant therapy in rectal adenocarcinoma

The response of rectal adenocarcinoma to neoadjuvant therapy is variable. Accurate prediction of response would enable selective administration of therapy. The enzyme glutathione S-transferase Pi (GSTP1) has been shown to influence response to therapy in some solid tumours. Few data are available for rectal cancer. The GSTP1 levels in rectal adenocarcinoma and adjacent normal mucosa were quantified before and after exposure to neoadjuvant therapy. Venous blood samples and biopsies of normal rectal mucosa and tumour were prospectively obtained from patients with primary rectal cancer. Patients were stratified by exposure to neoadjuvant therapy or surgery alone. GSTP1 was quantitatively measured using an enzyme-linked immunosorbent assay. Ninety-two patients (54 men; median age 68 years) were recruited. The median GSTP1 level was significantly higher in rectal adenocarcinoma than in matched normal mucosa [6.59 μg/mg vs 4.57 μg/mg; P < 0.001]. The median tumour GSTP1 level was significantly lower in the therapy group compared with unmatched samples from the no-therapy group [4.47 μg/mg vs 7.76 μg/mg; P < 0.001]. The GSTP1 level is increased in rectal adenocarcinoma compared with adjacent normal mucosa. It decreases following neoadjuvant therapy. Future studies correlating pre-therapy GSTP1 levels with pathological response would be of interest.

A Randomized Clinical Trial of the Effects of Supplemental Calcium and Vitamin D3 on the APC/β-Catenin Pathway in the Normal Mucosa of Colorectal Adenoma Patients

APC/β-catenin pathway perturbation is a common early event in colorectal carcinogenesis and is affected by calcium and vitamin D in basic science studies. To assess the effects of calcium and vitamin D on adenomatous polyposis coli (APC), β-catenin, and E-cadherin expression in the normal appearing colorectal mucosa of sporadic colorectal adenoma patients, we conducted a randomized, double-blinded, placebo-controlled 2 × 2 factorial clinical trial. Pathology-confirmed colorectal adenoma cases were treated with 2 g/day elemental calcium and/or 800 IU/day vitamin D(3) versus placebo over 6 months (N = 92; 23/group). Overall APC, β-catenin, and E-cadherin expression and distributions in colon crypts in normal-appearing rectal mucosa biopsies were detected by standardized automated immunohistochemistry and quantified by image analysis. In the vitamin D(3)-supplemented group relative to placebo, the proportion of APC in the upper 40% of crypts (Φh APC) increased 21% (P = 0.01), β-catenin decreased 12% (P = 0.18), E-cadherin increased 72% (P = 0.03), and the Φh APC/β-catenin ratio (APC/β-catenin score) increased 31% (P = 0.02). In the calcium-supplemented group Φh APC increased 10% (P = 0.12), β-catenin decreased 15% (P = 0.08), and the APC/β-catenin score increased 41% (P = 0.01). In the calcium/vitamin D(3)-supplemented group, β-catenin decreased 11% (P = 0.20), E-cadherin increased 51% (P = 0.08), and the APC/β-catenin score increased 16% (P = 0.26). These results support (i) that calcium and vitamin D modify APC, β-catenin, and E-cadherin expression in humans in directions hypothesized to reduce risk for colorectal neoplasms, (ii) calcium and vitamin D as potential chemopreventive agents against colorectal neoplasms, and (iii) the potential of APC, β-catenin, and E-cadherin expression as modifiable, preneoplastic risk biomarkers for colorectal neoplasms.

Nonreproducibility of “Snap-Frozen” Rectal Biopsies for Later Use in Ex Vivo Explant Infectibility Studies

Sexual transmission accounts for the majority of new HIV infections worldwide with sexually exposed cervicovaginal and colorectal mucosae being primary sites of infection. Two recent Phase 1 rectal microbicide trials included, as an ancillary endpoint, suppression of ex vivo HIV infection of in vivo microbicide-exposed rectal mucosal tissue biopsies. Both trials demonstrated significant suppression of biopsy infectibility in drug-exposed versus placebo-exposed tissue. This potential early biomarker of efficacy has raised the feasibility of utilizing "snap-frozen" tissue samples, acquired at multiple trial sites to be shipped for central processing, providing a mechanism to correlate tissue drug concentrations with a functional index of HIV prevention. While previous reports have indicated acceptable comparability of fresh versus freeze-thawed cervicovaginal tissue samples, no similar evaluations with colorectal tissue biopsies have been done. In this study, rectal biopsies from healthy, HIV-seronegative participants were assessed for structural integrity (histology), viability (MTT assays), and tissue infectibility to compare results from fresh versus combinations of freeze/thaw protocols. Results indicated that while all protocols showed equivalent viability with fresh samples (MTT), histology documented poor preservation of tissue integrity following freezing. Infectibility results from freeze-thawed colorectal tissue were markedly lower (usually<25% of fresh samples) and varied greatly and unpredictably. Centralized colorectal tissue infectibility assays using biopsies from remote trial sites cannot currently be supported under these protocols.

Diagnostic accuracy of rectal mucosa biopsy testing for chronic wasting disease within white-tailed deer (Odocoileus virginianus) herds in North America

An effective live animal diagnostic test is needed to assist in the control of chronic wasting disease (CWD), which has spread through captive and wild herds of white-tailed deer (Odocoileus virginianus) in Canada and the United States. In the present study, the diagnostic accuracy of rectal mucosa biopsy sample testing was determined in white-tailed deer from 4 CWD-infected captive herds. Specifically, the current study compared the immunohistochemical detection of disease-associated prion protein in postmortem rectal mucosa biopsy samples to the CWD status of each deer as determined by immunodiagnostic evaluations of the brainstem at the obex, the medial retropharyngeal lymph node, and the palatine tonsil. The effects of age, sex, genotype, and disease progression were also evaluated. Diagnostic sensitivity on rectal biopsy samples for CWD in white-tailed deer ranged from 63% to 100%; the pooled estimate of sensitivity was 68% with 95% confidence limits (95% CLs) of 49% and 82%. However, diagnostic sensitivity was dependent on genotype at prion protein gene (PRNP) codon 96 and on disease progression as assessed by obex grade. Diagnostic sensitivity was 76% (95% CLs: 49%, 91%) for 96GG deer but only 42% (95% CLs: 13%, 79%) for 96GS deer. Furthermore, diagnostic sensitivity was only 36% for deer in the earliest stage of disease (obex grade 0) but was 100% for deer in the last 2 stages of preclinical disease (obex grades 3 and 4). The overall diagnostic specificity was 99.8%. Selective use of antemortem rectal biopsy sample testing would provide valuable information during disease investigations of CWD-suspect deer herds.

Abstract 1675: Effects of calcium and vitamin D on TGFβ and TGFβ1 expression in rectal mucosa of sporadic colorectal adenoma patients: A randomized controlled trial

Abstract Aim: To estimate the effects of supplemental calcium and vitamin D3 on the expression of TGFβ and TGFβ1 (growth-promoting and -inhibiting autocrine/paracrine growth factors, respectively) in the normal-appearing colorectal mucosa in sporadic colorectal adenoma patients. Methods: We conducted a pilot, randomized, double-blind, placebo-controlled, 2 x 2 factorial clinical trial (n = 92) of calcium 2 g and/or vitamin D3 800 IU/day versus placebo over 6 months. TGFβ and TGFβ1 expression was measured in biopsies of normal-appearing rectal mucosa using automated immunohistochemistry and quantitative image analysis at baseline and 6-months follow-up. Results: The mean overall expression of TGFβ1 in the whole crypts increased by 14% (P = 0.25), 19% (P = 0.17), and 22% (P = 0.09) in the calcium, vitamin D, and calcium plus vitamin D groups, respectively, relative to the placebo group. The increases in TGFβ1 appeared to be uniform along the full length of the crypts. While there were no substantial changes in the overall expression of TGFβ in the whole crypts, in the calcium, vitamin D, and calcium plus vitamin D groups, TGFβ decreased by 14% (P = 0.35), 2% (P = 0.86), and 1% (P = 0.93), respectively, in the upper 40% (differentiation zone) of the crypts, but increased by 29% (P = 0.30), 38% (P = 0.17), and 25% (P = 0.32) in the bottom 60% of the crypts (proliferative zone). Also, a TGFβ/TGFβ1 ratio was created as an indicator of the balance between the growth-promoting and -inhibiting factors; in the upper 40% of the crypts it was found to have decreased by 35% (P = 0.24), 25% (P = 0.42), and 51% (P = 0.09) in the calcium, vitamin D, and calcium plus vitamin D groups, respectively, relative to the placebo group, but not to have changed substantially in the whole or bottom 60% of the crypts. Conclusions: These preliminary results suggest that supplemental calcium and vitamin D3 may increase the expression of TGFβ1, shift the expression of TGFβ downward in the colorectal crypts, and decrease the ratio of TGFβ to TGFβ1 in the upper 40% (differentiation zone) of the crypts in the normal-appearing colorectal mucosa of sporadic colorectal adenoma patients, and support further investigation of calcium and vitamin D3 as chemopreventive agents against colorectal neoplasms. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1675. doi:1538-7445.AM2012-1675

Curcumin consumption reduces gut microbial diversity among patients with colorectal adenomas

Preclinical studies suggest a role for curcumin in prevention of CRC, but there are few human studies to confirm its effects. Much of our diet is metabolized by gut bacteria, and bacterial dysbiosis is associated with colorectal adenomas, CRC precursors. We hypothesized that curcumin alters the gut microbiota. We assessed the composition of mucosally‐adherent bacteria in participants with (21 case) and without adenoma (14 control) before and after curcumin intake (4g/day for 4 weeks). Non‐prepped, rectal mucosal biopsies were used to assess bacterial profiles by terminal restriction fragment length polymorphism as well as qPCR of common gut bacterial groups. Bacterial diversity was reduced at follow‐up compared to baseline (p= 0.03). We observed reduction in copy numbers of all bacterial groups among cases following curcumin intervention; 47% E. coli, 30.7% Clostridium, 33% Bacteroides, 26% Eubacterium, 22% Bifidobacterium, and 20% Lactobacillus. Curcumin administration can reduce the adherent bacterial diversity in patients with colonic adenomas. Further understanding of the relationship between bacterial diversity and CRC may support a role for the chemopreventive properties of curcumin. Funding support by NIH P30 DK 034987, R01 CA136887, R01 CA044684, P50CA106991.

Lactobacillus plantarum 299v Does Not Reduce Enteric Bacteria or Bacterial Translocation in Patients Undergoing Colon Resection

Probiotics may exert beneficial effects in the gastrointestinal tract. This randomized trial investigated the effect of the probiotic Lactobacillus plantarum 299v on the intestinal load of potentially pathogenic bacteria, bacterial translocation, and cell proliferation in elective colon surgery. Seventy-five patients were randomized to pre- and postoperative oral intake of Lactobacillus plantarum 299v or placebo. Rectal swabs and mucosal biopsies were taken before the start of intake, after 1 week, at surgery, and after 6 days, weeks, and months. Viable counts were quantified for clostridia, Enterobacteriaceae, Gram-negative anaerobes, and lactobacilli. Bacterial translocation was determined by the analysis of bacterial DNA genes in mesenteric lymph nodes. Ki-67 was used as a marker of cell proliferation in normal mucosa and tumor. Lactobacillus plantarum 299v was given without adverse effects. Lactobacillus plantarum 299v as well as Enterobacteriaceae and Gram-negative anaerobes increased in the colon 1 week after the administration of Lactobacillus plantarum 299v. There were no significant differences between patients receiving Lactobacillus plantarum 299v and placebo in the incidence of bacterial translocation (27 vs. 13%) and postoperative complications (16 vs. 31%). Lactobacillus plantarum 299v was established in the intestine, but no inhibitory effect on enteric bacteria, bacterial translocation, or postoperative complications was found. The mechanism behind the protective effects of probiotics found in animal and some human studies remain elusive and require further explorations. No adverse effects were recorded after the administration of high doses of Lactobacillus plantarum 299v.

Adherent Escherichia coli in colorectal mucosal biopsies: A histological and ultrastructural evaluation

Colorectal mucosal biopsies occasionally demonstrate the presence of bacteria adherent to the epithelium. This study evaluated the histological and ultrastructural correlates of such bacterial adherence. Rectal mucosal biopsies from eight patients in whom histopathological examination of biopsies had earlier demonstrated adherent bacteria were examined by electron microscopy and by bacterial culture. Colorectal biopsies of 69 patients with adherent bacteria detected histologically were retrospectively evaluated for histological changes at sites proximal and distant to adherent bacteria. Escherichia coli of different serogroups were isolated from 7 of 8 rectal biopsies demonstrating bacterial adherence. All isolates showed diffuse or focal adherence to HEp-2 cell monolayers. Ultrastructural changes noted included microvillus damage, pedestal formation, actin web condensation, and protrusions of the apical cytoplasm of epithelial cells into the lumen towards the bacteria. Histological changes noted at light microscopy included reduction in epithelial cell height, focal epithelial cell degeneration, cryptitis and neutrophil infiltration at sites of bacterial adherence whereas these were usually absent at sites distant to adherent bacteria. Bacterial adherence was noted more often in biopsies from Crohn's disease patients than in patients without this diagnosis (P<0.001). Adherent Escherichia coli in colorectal biopsies were associated with focal epithelial damage and showed an association with Crohn's disease.

Association of TNFSF15 polymorphism with irritable bowel syndrome

BackgroundIrritable bowel syndrome (IBS) is the most common gastrointestinal disorder, affecting more than 10% of the general population worldwide. Although a genetic component is suspected, unambiguous susceptibility genes have so...

Abstract 1286: Pharmacodynamics of oral curcumin in plasma and rectal mucosa in a Phase IIa trial

Abstract Background: Curcumin, a dietary polyphenol derivative of turmeric, has potent cancer reductive activity in in vivo colon carcinogenesis models. We administered curcumin at doses of 2 g or 4 g to separate groups of 20 healthy human smokers with &amp;gt; 8 aberrant crypt foci (ACF). The 2 g dose showed no ACF reduction while the 4 g dose showed a 46% reduction (p&amp;lt;0.005) We analyzed native curcumin and its conjutes in matched plasma and rectal mucosa biopsy sample from 21 participants at 2g and 18 participants at 4g. Methods: Curcuminoid products were extracted from homogenized biopsy tissue and ultacentrifuged plasma and evaporated under argon. The separation was performed on a Symmetry® C18 column. The mobile phase used under gradient conditions was 25% acetonitrile with 74.9% containing 0.1% acetic acid (25:74.9:0.1; v/v/v; A) and 100% acetonitrile containing 0.1% acetic acid (99.9:0.1; v/v; B) The flow rate was 0.3 mL/min and injection volume for all samples was 10 µL. The lower limit of detection for curcumin from human plasma was 5 ng/mL and from human colonic mucosa was 50 ng/5mg tissue. Results: See Table below (summarized by pre and post treatment dose for plasma and mucosal concentrations) Conclusions: Native curcumin is not detectable in the majority of biopsy and plasma samples. Conjugated curcumin is detectable in all plasma samples and the majority of mucosal biopsies with a significant increase in plasma concentrations at 4g. We postulate the conjugates detected in the rectal mucosa are delivered systemically from absorption and conjugation higher in the gastrointestinal tract and may have biologic activity. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1286. doi:10.1158/1538-7445.AM2011-1286

Classical scrapie prions in ovine blood are associated with B lymphocytes and platelet-rich plasma

BackgroundClassical scrapie is a naturally occurring transmissible spongiform encephalopathy of sheep and goats characterized by cellular accumulation of abnormal isoforms of prion protein (PrPSc) in the central nervous system and the follicles of peripheral lymphoid tissues. Previous studies have shown that the whole blood and buffy coat blood fraction of scrapie infected sheep harbor prion infectivity. Although PrPSc has been detected in peripheral blood mononuclear cells (PBMCs), plasma, and more recently within a subpopulation of B lymphocytes, the infectivity status of these cells and plasma in sheep remains unknown. Therefore, the objective of this study was to determine whether circulating PBMCs, B lymphocytes and platelets from classical scrapie infected sheep harbor prion infectivity using a sheep bioassay.ResultsSerial rectal mucosal biopsy and immunohistochemistry were used to detect preclinical infection in lambs transfused with whole blood or blood cell fractions from preclinical or clinical scrapie infected sheep. PrPSc immunolabeling was detected in antemortem rectal and postmortem lymphoid tissues from recipient lambs receiving PBMCs (15/15), CD72+ B lymphocytes (3/3), CD21+ B lymphocytes (3/3) or platelet-rich plasma (2/3) fractions. As expected, whole blood (11/13) and buffy coat (5/5) recipients showed positive PrPSc labeling in lymphoid follicles. However, at 549 days post-transfusion, PrPSc was not detected in rectal or other lymphoid tissues in three sheep receiving platelet-poor plasma fraction.ConclusionsPrion infectivity was detected in circulating PBMCs, CD72+ pan B lymphocytes, the CD21+ subpopulation of B lymphocytes and platelet-rich plasma of classical scrapie infected sheep using a sheep bioassay. Combining platelets with B lymphocytes might enhance PrPSc detection levels in blood samples.

Diagnostische Aufarbeitung der chronischen Darmentzündung beim Pferd

The present retrospective study describes the diagnostic workup and collected findings in 7 horses with chronic inflammatory bowel disease over the years 2000-2006. The diagnosis could be confirmed histologically with biopsies taken during laparoscopy or laparotomy or during post mortem examination. Weight loss and chronic diarrhoea were the most commonly reported clinical findings. Among ancillary examinations (fecal analysis, gastroscopy, abdominal ultrasonography, rectal mucosal biopsy) the D-xylose absorption test provided the most useful information. Although clinical signs and laboratory findings are helpful diagnostic tools, a definitive diagnosis is only possible by histological analysis of the intestinal segment.

DNA Methylation in the Rectal Mucosa Is Associated with Crypt Proliferation and Fecal Short-Chain Fatty Acids

DNA methylation varies throughout the normal colorectal mucosa and DNA methylation in normal appearing mucosa is associated with serrated and adenomatous neoplasia elsewhere within the colorectum. The purpose of this study was to measure luminal chemistry, rectal proliferation and mucosal DNA methylation and thus determine whether regional and pathological patterns of DNA methylation could be explained by luminal and epithelial factors. Twenty healthy subjects had normal rectal mucosal biopsies and a 24-h fecal collection. Rectal biopsies were analyzed for epithelial proliferation (Ki67 immunohistochemistry) and DNA methylation at 17 different markers, including "type A" markers (ESR1, GATA5, HIC1, HPP1, SFRP1), "type C" markers (MGMT, MLH1, CDKN2A, MINT1, MINT2, MINT31, IGF2, CACNA1G, NEUROG1, SOCS1, RUNX3), and LINE-1. Fecal analysis included short-chain fatty acids (SCFA), pH and ammonia. Mean "type A" and CIMP panel methylation Z-scores were calculated. Rectal proliferation was significantly correlated with methylation at ESR1 (ρ = 0.81, P = 0.003) and GATA5 (ρ = 0.78, P = 0.012). LINE-1 methylation was 71.7 vs. 74.1%, in patients with "low" and "high" fecal total SCFA concentration (defined by the median value), respectively (P = 0.0019). On multivariate linear regression "type A" methylation was independently associated with rectal proliferation (P = 0.001). LINE-1 methylation was directly associated with rectal proliferation (P = 0.038) and total fecal SCFA concentration (P = 0.002), and inversely associated with fecal NH(3) concentrations (P = 0.003). DNA methylation in normal rectal mucosa is associated with crypt proliferation and fecal SCFA concentration. These associations may help to explain regional differences in DNA methylation as well as providing a possible link between the colorectal lumen and carcinogenesis.

An assessment of the efficiency of PrPsc detection in rectal mucosa and third-eyelid biopsies from animals infected with scrapie

In classical scrapie, detection of PrPsc on lymphoreticular system is used for the in vivo and post mortem diagnosis of the disease. However, the sensitivity of this methodology is not well characterised because the magnitude and duration of lymphoid tissue involvement can vary considerably. The aim of the present study was to evaluate the efficiency of detecting PrPsc in rectal mucosa and third-eyelid biopsies. A total of 474 genetically susceptible sheep and 24 goats from three scrapie infected flocks were included in this study. A sample from rectal mucosa and a sample from third-eyelid lymphoid tissue were collected from each animal. Biopsy samples were fixed in formaldehyde and processed for immunohistochemical examination. Animals with negative biopsy results were studied more closely through a post mortem examination of central nervous and lymphoreticular systems and if there was a positive result, additional biopsy sections were further tested. The sensitivity of rectal mucosa and third-eyelid assays were 36% and 40% respectively on initial examination but increased to 48% and 44% respectively after retesting. The results of this field study show a high percentage of infected animals that do not have detectable levels of PrPsc in the biopsied lymphoid tissue, due mainly to the relatively high number of animals with minimal or no involvement of lymphoid tissue in the pathogenesis of the disease.

Relation between normal rectal methylation, smoking status, and the presence or absence of colorectal adenomas

Colorectal cancer (CRC) is 1 of the leading causes of death in the Western world. CRC develops from premalignant lesions, chiefly colorectal adenomas. Currently, the most accurate and recommended screening method for finding colorectal adenomas is colonoscopy performed on all individuals aged>50 years. However, the costs and risks associated with this procedure are relatively high. The objectives of the current study were to correlate epigenetic alterations that occur in normal rectal mucosa, smoking status, and age with the presence or absence of concomitant colorectal adenomas and to assess the potential clinical value of methylation in normal rectal biopsies as a screening assay for the presence of polyps and, hence, the need for a full colonoscopy. One hundred thirteen normal rectal mucosal biopsies from 113 patients were studied. DNA was extracted, modified with sodium bisulfite, and subjected to real-time quantitative, methylation-specific polymerase chain reaction analysis for the following genes: adenomatous polyposis coli (APC); cadherin 1, type 1, E-cadherin (epithelial) (CDH1); estrogen receptor 1 (ESR1); cytokine high in normal 1 (HIN1); hyperplastic polyposis protein 1 (HPP1); O-6 methylguanine-DNA methyltransferase (MGMT); neural epidermal growth factor-like 1 (NELL1); splicing factor 3B, 14-kDa subunit (p14); cyclin-dependent kinase (CDK) inhibitor 2B (inhibits CDK4) (p15); retinoic acid receptor beta (RARβ); somatostatin (SST); tachykinin, precursor 1 (TAC1); and tissue inhibitor of metalloproteinase (TIMP) metallopeptidase inhibitor 3 (TIMP3). Data were then analyzed using several proprietary software programs. By using several sets of genes, clinical characteristics, and multivariate analyses, the authors developed a prediction model for the presence of concomitant colorectal adenomas at the time of rectal biopsy. They also observed strong correlations between smoking status and rectal methylation pattern and between smoking status and the presence or risk of concomitant adenomas. A prediction model was developed for the presence of colorectal adenomas based on gene methylation patterns in the normal rectum. The results indicated that these genes may be involved in early stages of adenoma formation. The observed epigenetic alterations in these markers may be caused in part by the effects of smoking and/or age. Normal rectal methylation may be useful as a biomarker for narrowing the population in need of screening colonoscopy.

Zwanzig Jahre diagnostisches Hirschsprung-Kompetenzzentrum in Basel

The experience gained by the Basel Hirschsprung Competence Center over 20 years is presented. A total of 19,365 rectal mucosal biopsies were investigated in the 20 years between 1987 and 2006. All biopsies of rectal mucosa originated from 6,615 children aged between 1 week and 4 years. Biopsies were collected in teaching hospitals all over Germany and transported on dry ice by Intercity Courier Service. Serial sections of frozen tissue were made using a cryostat. Enzyme histochemical staining was performed. A total of 935 cases of Hirschsprung's disease (14%) were observed (769 cases of classical Hirschsprung's disease, 68 total colon aganglionosis, 98 ultrashort rectum aganglionosis). Total colon aganglionosis was found in 1.0% and the frequency of ultrashort Hirschsprung' disease was 1.4%. The quality of the histological results was confirmed by a second independent investigator. There were neither false positive nor false negative diagnoses. Enzyme histochemical staining results were readable within 2 h. Acetylcholinesterase, which is significantly increased in Hirschsprung's disease, was used for nerve fiber staining. Succinic and lactic dehydrogenases and nitric oxide synthase served as confirmatory proof of aganglionosis (elective nerve cell staining of the submucous plexus). Among 100 children with chronic constipation an average of 12 children were diagnosed with Hirschsprung's disease. Of these 2% showed total colon aganglionosis or ultrashort Hirschsprung's disease. Enzyme histochemical diagnosis of Hirschsprung's disease proved 100% reliable and time saving.

Effects of Calcium and Vitamin D on MLH1 and MSH2 Expression in Rectal Mucosa of Sporadic Colorectal Adenoma Patients

To further clarify and develop calcium and vitamin D as chemopreventive agents against colorectal cancer in humans and develop modifiable biomarkers of risk for colorectal cancer, we conducted a pilot, randomized, double-blind, placebo-controlled, 2 x 2 factorial clinical trial to test the effects of calcium and vitamin D(3), alone and in combination, on key DNA mismatch repair proteins in the normal colorectal mucosa. Ninety-two men and women with at least one pathology-confirmed colorectal adenoma were treated with 2.0 g/d calcium or 800 IU/d vitamin D(3), alone or in combination, versus placebo over 6 months. Colorectal crypt overall expression and distribution of MSH2 and MLH1 proteins in biopsies of normal-appearing rectal mucosa were detected by automated immunohistochemistry and quantified by image analysis. After 6 months of treatment, MSH2 expression along the full lengths of crypts increased by 61% (P = 0.11) and 30% (P = 0.36) in the vitamin D and calcium groups, respectively, relative to the placebo group. The estimated calcium and vitamin D treatment effects were more pronounced in the upper 40% of crypts (differentiation zone) in which MSH2 expression increased by 169% (P = 0.04) and 107% (P = 0.13) in the vitamin D and calcium groups, respectively. These findings suggest that higher calcium and vitamin D intakes may result in increased DNA MMR system activity in the normal colorectal mucosa of sporadic adenoma patients and that the strongest effects may be vitamin D related and in the differentiation zone of the colorectal crypt.

Effects of Supplemental Vitamin D and Calcium on Oxidative DNA Damage Marker in Normal Colorectal Mucosa: A Randomized Clinical Trial

The exact antineoplastic effects of calcium and vitamin D(3) in the human colon are unclear. Animal and in vitro studies show that these two agents reduce oxidative stress; however, these findings have never been investigated in humans. To address this, we conducted a pilot, randomized, double-blind, placebo-controlled, 2 x 2 factorial clinical trial to test the effects of calcium and vitamin D(3) on a marker of oxidative DNA damage, 8-hydroxy-2'-deoxyguanosine (8-OH-dG), in the normal colorectal mucosa. Patients (N = 92) with at least one pathology-confirmed colorectal adenoma were treated with 2 g/d calcium and/or 800 IU/d vitamin D(3) versus placebo over 6 months. Overall labeling and colorectal crypt distribution of 8-OH-dG in biopsies of normal-appearing rectal mucosa were detected by standardized automated immunohistochemistry and quantified by image analysis. After 6 months of treatment, 8-OH-dG labeling along the full lengths of colorectal crypts decreased by 22% (P = 0.15) and 25% (P = 0.10) in the calcium and vitamin D(3) groups, respectively, but not in the calcium plus vitamin D(3) group. The estimated treatment effects were strongest among participants with higher baseline colon crypt vitamin D receptor expression (P = 0.05). Overall, these preliminary results indicate that calcium and vitamin D(3) may decrease oxidative DNA damage in the normal human colorectal mucosa, support the hypothesis that 8-OH-dG labeling in colorectal crypts is a treatable oxidative DNA damage biomarker of risk for colorectal neoplasms, and provide support for further investigation of calcium and vitamin D(3) as chemopreventive agents against colorectal neoplasms.

Impact of Age and Sex of Rocky Mountain Elk (Cervus Elaphus Nelsoni) on Follicle Counts from Rectal Mucosal Biopsies for Preclinical Detection of Chronic Wasting Disease

To determine if the number of rectal lymphoid follicles decreases with respect to age and sex relative to diagnosis of chronic wasting disease (CWD), rectal biopsies (n = 1,361) were taken from captive Rocky Mountain elk (Cervus elaphus nelsoni) at 4 ranches in the western United States between 2005 and 2008. Rectal tissues were stained with a monoclonal antibody (F99/97.6.1), which selectively stains the abnormal isoform of the prion protein associated with CWD of elk. The number of lymphoid follicles obtained from typical biopsy tissues decreased with the age of the animal. The acceptable number of lymphoid follicles for detection of CWD was not considered to be a problem in elk up to 8.5 years of age, but in elk over 8.5 years of age, the follicle count was considered to be low. Sex of the animal had no effect on the number of lymphoid follicles observed in each age group. Rectal biopsies were an accurate test to diagnose preclinical stages of CWD in elk but may be best suited to elk that are less then 8.5 years of age.