Colonic Biopsies Research Articles

Helicobacter pylori promotes colorectal carcinogenesis by deregulating intestinal immunity and inducing a mucus-degrading microbiota signature

ObjectiveHelicobacter pylori infection is the most prevalent bacterial infection worldwide. Besides being the most important risk factor for gastric cancer development, epidemiological data show that infected individuals harbour a nearly...

The Association between Caffeine Intake and the Colonic Mucosa-Associated Gut Microbiota in Humans-A Preliminary Investigation.

We examined the association between caffeine and coffee intake and the community composition and structure of colonic microbiota. A total of 34 polyp-free adults donated 97 colonic biopsies. Microbial DNA was sequenced for the 16S rRNA gene V4 region. The amplicon sequence variant was assigned using DADA2 and SILVA. Food consumption was ascertained using a food frequency questionnaire. We compared the relative abundance of taxonomies by low (<82.9 mg) vs. high (≥82.9 mg) caffeine intake and by never or <2 cups vs. 2 cups vs. ≥3 cups coffee intake. False discovery rate-adjusted p values (q values) <0.05 indicated statistical significance. Multivariable negative binomial regression models were used to estimate the incidence rate ratio and its 95% confidence interval of having a non-zero count of certain bacteria by intake level. Higher caffeine and coffee intake was related to higher alpha diversity (Shannon index p < 0.001), higher relative abundance of Faecalibacterium and Alistipes, and lower relative abundance of Erysipelatoclostridium (q values < 0.05). After adjustment of vitamin B2 in multivariate analysis, the significant inverse association between Erysipelatoclostridium count and caffeine intake remained statistically significant. Our preliminary study could not evaluate other prebiotics in coffee.

DNA content abnormality frequently develops in the right/proximal colon in patients with primary sclerosing cholangitis and inflammatory bowel disease and is highly predictive of subsequent detection of dysplasia.

Patients with primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD, termed PSC-IBD) have a higher risk of harbouring nonconventional and/or invisible dysplasias, especially in the right/proximal colon, than those with IBD alone. We postulated that DNA content abnormality may be frequently detected in the right/proximal colon in PSC-IBD patients, even in the absence of dysplasia, and that this may predispose to progression to nonconventional and/or invisible dysplasias that are often associated with increased rates of aneuploidy and advanced neoplasia. DNA flow cytometry was performed on 96 morphologically benign colon biopsies taken throughout the colon from 25 PSC-IBD patients during the surveillance colonoscopy that preceded the next procedure that detected dysplasia. Thirty (31%) of the 96 benign colon biopsies in this dysplasia group demonstrated abnormal DNA content, with a propensity for the right/proximal colon (70%) (P < 0.001). In contrast, only one (1%) of 87 benign colon biopsies from 20 IBD patients without neoplasia (control group) demonstrated DNA content abnormality, and it was from the left colon. For analysis per patient, 48% (12 of 25) of the patients in the dysplasia group had abnormal DNA content compared with 5% (1 of 20) of the control group (P = 0.002). Of the 12 PSC-IBD patients with DNA content abnormality, invisible dysplasia was detected in 10 (83%) patients on follow-up, nine (75%) of whom had nonconventional dysplasia. PSC-IBD patients have an increased risk of developing abnormal DNA content in the right/proximal colon, predating the detection of dysplasia.

The Robogut: A Bioreactor Model of the Human Colon for Evaluation of Gut Microbial Community Ecology and Function

The human colon is inhabited by a complex community of microbes. These microbes are integral to host health and physiology. Understanding how and when the microbiome causally influences host health will require microbiome models that can be tightly controlled and manipulated. While in vivo models are unrivalled in their ability to study host-microbial interplay, in vitro models are gaining in popularity as methods to study the ecology and function of the gut microbiota, and benefit from tight controllability and reproducibility, as well as reduced ethical constraints. In this set of protocols, we describe the Robogut, a single-stage bioreactor system designed to replicate the conditions of the distal human colon, to culture whole microbial communities derived from stool and/or colonic biopsy samples, with consideration of methods to create culture medium formulations and to build, run, and sample the bioreactor apparatus. Cleaning and maintenance of the bioreactor system are also described. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Growth medium preparation Support Protocol 1: Preparing medium supplements Basic Protocol 2: Preparing the bioreactor vessels Support Protocol 2: Making acid and base bottles Support Protocol 3: Preparing the effluent bottles Support Protocol 4: Making acid solution Support Protocol 5: Making base solution Basic Protocol 3: Preparing inoculum and inoculating bioreactors Alternate Protocol 1: Preparing inoculum less than 0.5% (w/v) of vessel volume Alternate Protocol 2: Preparing synthetic community aliquots and inoculation via the septum Alternate Protocol 3: Preparing inoculum from a tissue sample Basic Protocol 4: Sampling the bioreactor vessel Basic Protocol 5: Harvesting bioreactor vessel contents at end of experiment Support Protocol 6: Cleaning and sterilizing sampling needles Basic Protocol 6: Cleaning the bioreactor vessel Support Protocol 7: Cleaning bioreactor support bottles.

Diet prevents the expansion of segmented filamentous bacteria and ileo-colonic inflammation in a model of Crohn’s disease

BackgroundCrohn’s disease (CD) is associated with changes in the microbiota, and murine models of CD-like ileo-colonic inflammation depend on the presence of microbial triggers. Increased abundance of unknown Clostridiales and the microscopic detection of filamentous structures close to the epithelium of TnfΔARE mice, a mouse model of CD-like ileitis pointed towards segmented filamentous bacteria (SFB), a commensal mucosal adherent bacterium involved in ileal inflammation.ResultsWe show that the abundance of SFB strongly correlates with the severity of CD-like ileal inflammation in two mouse models of ileal inflammation, including TnfΔARE and SAMP/Yit mice. SFB mono-colonization of germ-free TnfΔARE mice confirmed the causal link and resulted in severe ileo-colonic inflammation, characterized by elevated tissue levels of Tnf and Il-17A, neutrophil infiltration and loss of Paneth and goblet cell function. Co-colonization of SFB in human-microbiota associated TnfΔARE mice confirmed that SFB presence is indispensable for disease development. Screening of 468 ileal and colonic mucosal biopsies from adult and pediatric IBD patients, using previously published and newly designed human SFB-specific primer sets, showed no presence of SFB in human tissue samples, suggesting a species-specific functionality of the pathobiont. Simulating the human relevant therapeutic effect of exclusive enteral nutrition (EEN), EEN-like purified diet antagonized SFB colonization and prevented disease development in TnfΔARE mice, providing functional evidence for the protective mechanism of diet in modulating microbiota-dependent inflammation in IBD.ConclusionsWe identified a novel pathogenic role of SFB in driving severe CD-like ileo-colonic inflammation characterized by loss of Paneth and goblet cell functions in TnfΔARE mice. A purified diet antagonized SFB colonization and prevented disease development in TnfΔARE mice in contrast to a fiber-containing chow diet, clearly demonstrating the important role of diet in modulating a novel IBD-relevant pathobiont and supporting a direct link between diet and microbial communities in mediating protective functions.8ntX7JCRAmgBnFgN24WWkMVideo

THE EFFECTS OF BIOLOGIC AND SMALL MOLECULE INHIBITOR THERAPY ON THE MUCOSAL IMMUNE SYSTEM IN ULCERATIVE COLITIS

Ulcerative colitis (UC) is a subtype of inflammatory bowel disease (IBD) that causes relapsing and remitting inflammation in the colon and rectum. Numerous treatment options are available for patients with UC including biologics and small molecule inhibitors that target the immune system. Although these therapies have dramatically improved options for patients with IBD, there remains a modest ceiling for their overall efficacy. Currently there are no biomarkers that can guide treatment decisions in patients with UC. Some studies have reported certain molecules or immune populations that are associated with treatment resistance or as predictors of treatment response. However, their clinical utility have yet to be fully determined because there is a paucity of longitudinal studies examining the direct effects of current biologics and small molecule inhibitors approved for UC on the immune biology of the colon mucosa. In this study, we perform longitudinal immune phenotyping using flow cytometry in patients with UC before and after therapy. Colon biopsy tissue was taken prior to treatment from 10 UC patients who were then followed and repeat biopsies were obtained from the same patients after 6-12 months of treatment. Tissue was analyzed using high dimensional flow cytometry with a panel of 24 markers of both lymphoid and myeloid lineages. Pre-treatment samples with inflammation correlated with higher populations of CD4+ T cells and CD4+ FOXP3 regulatory T cells also positive for TIGIT and GITR. Inflammation also corresponded with the presence of a CD33+ HLA-DR- population classically known as myeloid-derived suppressor cells (MDSC). Overall, therapy significantly decreased immune cell infiltration in the colon, most notably in B and T cell populations. However, certain treatments increased the MDSC population along with the stromal compartment of non-immune cells. A comprehensive analysis of the populations present during active inflammation and the treatment-induced changes in mucosal immunity will help identify biomarkers to predict response to therapy. In addition, examining the interplay between immune cells and the surrounding stroma can may lead to important findings that improve our understanding of each drug’s mechanism and efficacy. Future experiments with single cell RNA and T cell receptor sequencing on the same patients will identify effects of biologic therapy on the T cell repertoire and interactions between immune, epithelial, and stromal cells in the colonic mucosa. With the advent of novel sequencing and immune profiling assays, we now have the ability to harness the power of precision medicine to make more informed therapeutic decisions for IBD patients that improve clinical outcomes.

A NOVEL DRUG THERAPY INDUCES MITOCHONDRIAL BIOGENESIS AND ATTENUATES COLITIS

Mitochondrial dysfunction is a characteristic feature of intestinal epithelium cells (IEC) in IBD patients, associated with oxidative stress and impaired ATP production. We posit that disrupted mitochondrial bioenergetics impairs ulcer healing in IBD. In the current study, we tested a novel gold-based compound (AuPhos) that improves mitochondrial function by increasing mitochondrial biogenesis and antioxidant enzymes in IEC and human colonic biopsies.

PRIMARY EOSINOPHILIC COLITIS WITH CONCOMITANT NEWLY DIAGNOSED INFLAMMATORY BOWEL DISEASE – A DIAGNOSITIC CONUNDRUM

Eosinophilic colitis (EC) is a rare primary condition characterized by eosinophilic infiltration of the colon in the absence of secondary causes. Affecting only 0.003% of people in the United States, clinical manifestations of the disease can range from abdominal pain, bloody stools, and diarrhea to colonic obstruction, intussusception, volvulus, and perforation. The diagnosis is made upon histopathological analysis of colonic biopsies with the inflammatory infiltrate consisting predominantly or exclusively of eosinophils with focal collections greater than 100 per high-power field (hpf). Unlike inflammatory bowel disease (IBD), granulomas, crypt architectural distortion, pseudopyloric metaplasia, and fibrosis are not usually present with EC, but differentiating between the two conditions has proven to be difficult over the decades.

Concomitant Campylobacteriosis in a Puppy and in Its Caregiver: A One Health Perspective Paradigm in Human-Pet Relationship

We report a case of laboratory-confirmed Campylobacter (C). jejuni and C. upsaliensis symptomatic infection in a puppy, a French Bouledogue, female, 6 months of age, fed a raw, unbalanced, poultry-based diet (RPD), (48.1 CP, 33% EE, 0.3% Ca, 0.5% Phos, 0.5 Ca/P, on a dry-matter basis), and in its owner. Soon after adoption, the pet and the caregiver showed severe gastrointestinal signs and needed hospitalization. Fecal PCR assays, selective cultures, and antibiotic susceptibility testing were performed, and multi-drug resistant C. jejuni and C. upsaliensis were isolated from the feces of both. The same bacteria were also identified by FISH in the dog colonic biopsies collected during endoscopy. The puppy was prescribed a complete commercial diet for growing dogs, (30.00% CP, 21.00% EE, 1.2% Ca; 1% Phos; as fed) and treated with ciprofloxacin. The dog and the man healed uneventfully and tested negative for further fecal PCR analyses. This report focuses on dog nutritional management and explores the potential routes of exposure, with emphasis on emerging outbreaks related to current pet food fads. Our data support the One Health approach, where veterinarians, physicians, and owners are challenged to build effective stewardship to prevent the spread of zoonoses.

The Role of Globularia alypum Explored Ex Vivo In Vitro on Human Colon Biopsies from Ulcerative Colitis Patients.

The existing literature indicates that Globularia alypum L. (GA) influences inflammation and oxidative stress modulation in rats and in vitro. The present study aims to investigate the effects of this plant in patients with ulcerative colitis (UC) and normal controls. In our experiments, we pretreated colon biopsies from 46 UC patients and normal controls with GA leaves aqueous extract (GAAE) used at two concentrations (50 and 100 µg/mL) for 3 h, followed by Lipopolysaccharides (from Escherichia coli) stimulation. We analyzed the effects on inflammation by studying the cyclo-oxygenase-2, the intercellular adhesion molecule-1, the nuclear factor kappa B, and p38 mitogen-activated protein kinase expression. Moreover, we assessed the levels of interleukin 6, the superoxide dismutase activity, and nitric oxide release in the supernatant of cultures. Our data showed that GAAE influences UC patients and normal controls for most studied markers and enzymes. These results acknowledge, with some scientific evidence, the traditional belief in the anti-inflammatory properties of GA and represent the first demonstration of its effect in a human in vitro model of inflammatory conditions.

Identification of FCN1 as a novel macrophage infiltration-associated biomarker for diagnosis of pediatric inflammatory bowel diseases

BackgroundThe incidence of pediatric inflammatory bowel disease (PIBD) has been steadily increasing globally. Delayed diagnosis of PIBD increases the risk of complications and contributes to growth retardation. To improve long-term outcomes, there is a pressing need to identify novel markers for early diagnosis of PIBD.MethodsThe candidate biomarkers for PIBD were identified from the GSE117993 dataset by two machine learning algorithms, namely LASSO and mSVM-RFE, and externally validated in the GSE126124 dataset and our PIBD cohort. The role of ficolin-1 (FCN1) in PIBD and its association with macrophage infiltration was investigated using the CIBERSORT method and enrichment analysis of the single-cell dataset GSE121380, and further validated using immunoblotting, qRT-PCR, and immunostaining in colon biopsies from PIBD patients, a juvenile murine DSS-induced colitis model, and THP-1-derived macrophages.ResultsFCN1 showed great diagnostic performance for PIBD in an independent clinical cohort with the AUC of 0.986. FCN1 expression was upregulated in both colorectal biopsies and blood samples from PIBD patients. Functionally, FCN1 was associated with immune-related processes in the colonic mucosa of PIBD patients, and correlated with increased proinflammatory M1 macrophage infiltration. Furthermore, single-cell transcriptome analysis and immunostaining revealed that FCN1 was almost exclusively expressed in macrophages infiltrating the colonic mucosa of PIBD patients, and these FCN1+ macrophages were related to hyper-inflammation. Notably, proinflammatory M1 macrophages derived from THP-1 expressed high levels of FCN1 and IL-1β, and FCN1 overexpression in THP-1-derived macrophages strongly promoted LPS-induced activation of the proinflammatory cytokine IL-1β via the NLRP3-caspase-1 axis.ConclusionsFCN1 is a novel and promising diagnostic biomarker for PIBD. FCN1+ macrophages enriched in the colonic mucosa of PIBD exhibit proinflammatory phenotypes, and FCN1 promotes IL-1β maturation in macrophages via the NLRP3-caspase-1 axis.

Hidden colon adenocarcinoma diagnosed from mouth metastasis: case report and literature review

BackgroundWe report an unusual case of metastatic colon adenocarcinoma to the maxilla as an initial clinical sign of the disease, this being the second case reported in the palate. In addition, we show an extensive review of the literature, with clinical cases of adenocarcinoma with metastasis to the mouth.Case presentationAn 80-year-old man complained of “swelling on the palate” with a 3-week evolution time. He reported suffering from constipation and high blood pressure. The intraoral examination revealed a pedunculated, red, and painless nodule on the maxillary gingiva. Under the diagnostic hypotheses of squamous cell carcinoma and malignant neoplasm of the salivary gland, an incisional biopsy was performed. Microscopically, the columnar epithelium was observed forming papillary areas, neoplastic cells with prominent nucleoli, hyperchromatic nuclei, atypical mitotic figures, and mucous cells, being positive for CK 20, suggesting the provisional diagnosis of metastatic adenocarcinoma, probably of gastrointestinal origin. The patient was submitted to endoscopy and colonoscopy exams, and a lesion in the sigmoid region of the colon was observed. After a colon biopsy, a moderately differentiated adenocarcinoma was confirmed, establishing the final diagnosis of metastatic neoplasia of colon adenocarcinoma to the oral lesion. The literature review revealed 45 clinical cases of colon adenocarcinoma with metastasis to the oral cavity. To the best of our knowledge, it is the second case on the palate.ConclusionsColon adenocarcinoma with metastasis to the oral cavity is rare but should be included in the differential diagnosis of neoplasms of the oral cavity, even when there are no known primary tumors in some cases, and this may be the first indication of the presence of a tumor.

HISTOPATHOLOGICAL FEATURES IN RELAPSE OF ULCERATIVE COLITIS.

Background and objective: To determine the frequencies of various histopathological features of relapse in previously diagnosed cases of ulcerative colitis . Methods: This was a Cross sectional study conducted at Histopathology department of Sheikh Zayed hospital Lahore from 1/6/2014 to 1/12/2014. Two hundred and seventy colonic biopsies were assessed using 3% margin of error and 95% of the confidence level. Patients clinically relapsed with ulcerative colitis including both genders in age group from 11 to 80 years were included. Biopsy specimen fixed in 10% formalin were received. Processing was done and sections stained with hematoxylin and were examined by the pathologist. College of Physicians and Surgeons Pakistan gave approval for this study. Data was then analyzed and entered by the SPSS version15. Results: Total number of patients were 270,out of which all of the patients have shown chronic inflammation and increase number of neutrophils in lamina propria (100%), focal lymphoid aggregate in 162/270(60%), increased number of eosinophils in lamina propria in 108/270(40%), cryptitis in 216/270(80%), crypt distortion in 202/270(75%), mucin depletion in151/270 (56%) and crypt abscess formation in 148/270(55%). Conclusion: Hence, cryptitis and crypt abscess were observed to be most commonly occurring significant and reliable featuress of relapse in ulcerative colitis.

A27 DNA HYPOMETHYLATION INDUCED BY 5-AZA-CDR OR LOSS OF DNMT1 INHIBITS COLITIS-ASSOCIATED COLORECTAL CANCER

Abstract Background Colorectal cancer is the second leading cause of cancer death in Canada. A major risk factor for the development of colorectal cancer is chronic inflammation leading to colitis-associated cancer (CAC). We previously described a CAC mouse model in which tumors arise from DCLK1+ tuft cells following loss of the tumor suppressor adenomatous polyposis coli (APC) and induction of colitis. Interestingly, both colitis and CAC display epigenetic changes that modulate gene expression. However, the impact of DNA methylation changes on colonic tumorigenesis is not known. Thus, we hypothesize that inhibition of DNA methylation in DCLK1+ tuft cells reduces colonic tumorigenesis. Purpose In this study, we aim to investigate the role of DNA methylation in CAC by inhibiting DNA methylation using genetic and pharmacologic means. Method Using a publicly available dataset (GSE75214) of gene expression data analyzed by microarray from colonic biopsies of patients with ulcerative colitis and Crohn’s Disease with active disease, we examined the expression of DNA methyltransferases (DNMTs). Expression of DNMTs in mice with colitis was additionally examined by RT-qPCR and global DNA methylation levels measured by 5-mC ELISA. In separate experiments, Dclk1-CreERT2/Apcf/f mice were crossed to DNMT1f/f mice to knock-out the DNA methyltransferase DNMT1 in DCLK1+ tuft cells. Dclk1/Apcf/f and Dclk1/Apcf/f/DNMT1f/f mice were then administered three doses of tamoxifen followed by 2.5% dextran sodium sulfate (DSS) for five days to induce colitis. Fourteen weeks later, we assessed colonic tumor number and size. In a separate cohort of Dclk1/Apcf/f mice, we induced colitis and treated the mice with six doses of the DNA de-methylating drug 5-AZA-2’-deoxycytidine (5-AZA) or vehicle, and assessed colonic tumor number. To examine DNA methylation changes, we then treated WT mice with 5-AZA and DSS and isolated intestinal epithelial cells. From the intestinal epithelial cell, we isolated DNA and ran the Infinium MouseMethylation BeadChip Array. Result(s) Patients with IBD were found to have increased expression of DNMT1 compared to healthy controls. Mice treated with DSS similarly had increased DNMT1 expression, as well as, global methylation levels compared to controls. Deletion of DNMT1 in DCLK1+ cells significantly inhibited the number and size of colonic tumors. Treatment of mice with 5-AZA decreased global and gene specific DNA methylation levels, and significantly reduced both the number of mice with tumors, and the average colonic tumor number and size per mouse. Conclusion(s) Our findings demonstrate that colitis in both patients and mice is associated with DNA methylation. Furthermore, DNA hypomethylation by 5-AZA treatment or loss of DNMT1 reduces CAC formation suggesting that altered DNA methylation plays a critical role in colonic tumorigenesis. Disclosure of Interest None Declared

A187 DIETARY FIBERS ELICIT GUT IMMUNE AND EPITHELIAL BARRIER MODIFYING EFFECTS IN INFLAMMATORY BOWEL DISEASES BASED ON FOOD SOURCE AND FIBER CHEMICAL FEATURES

Abstract Background Dietary fibers are not digested in the bowel; they are fermented by microbes, typically promoting gut health. However, IBD patients experience sensitivity to consumption of fibers. Our previous findings offered the first mechanistic evidence demonstrating that unfermented dietary β-fructans (inulin and oligofructose) can induce pro-inflammatory cytokines and altered epithelial barrier integrity in a subset of pediatric IBD colonic biopsies cultured ex vivo, and in the SYNERGY-1 (β-fructan) clinical study of adult remission UC patients. Fermentation of β-fructan by whole-microbiota intestinal washes from non-IBD or remission IBD patients (but not non-IBD microbes) reduced pro-inflammatory responses. Purpose Here we aimed to expand our findings to uncover the physiologically relevant gut immune and epithelial responses to over 50 unfermented and partially fermented dietary fibers (arabinoxylans, β-glucans, β-mannans, galatooligosaccharides, inulins, oligofructoses, pectins, raffinooligosaccharides, xyloglucans) sourced from commonly consumed fruits, grains, and vegetables to better understand which foods are safe for IBD patients, and in which disease state settings. Method Colonic biopsies cultured ex vivo, peripheral blood mononuclear cells (PBMCs), colonic organoids, and cell lines were incubated with individual dietary fibers or mixture of fibers extracted from commonly consumed fruits, grains, and vegetables. Epithelial barrier integrity (TEER, microscopy, FITC-dextran) and immune responses (cytokine secretion [ELISA/MSD] and expression [qPCR]) were assessed. Structural features of the different fibers (e.g., degree of polymerization, phenolic/phytic content, branching, sugar content) were measured by HPLC and gas chromatography and correlated to host cell responses. Result(s) Most significantly unfermented inulin, oligofructose, and arabinoxylan induced pro-inflammatory responses, particularly in myeloid cells. Pectin and galatooligosaccharides were either non-inflammatory or anti-inflammatory depending on the food source. The epithelial barrier response to select dietary fibers correlated more significantly with the chemical properties of the fibers; longer fibers (greater degree of polymerization; e.g., inulin) displayed improved barrier integrity while shorter dietary fibers with higher phenolic content displayed reduced barrier integrity. Fiber structural properties varied significantly between different fiber subtypes along with the same fiber subtype sourced from different foods. Conclusion(s) Our findings suggest that intolerance and avoidance of fibers in select IBD patients occurs in patients whose gut microbiota do not support fermentation of fibers resulting in increased presence of unfermented dietary fibers in the gut. Here we show which specific dietary fibers from specific food items can elicit gut barrier damage and inflammation in the gut dependent on fiber structural features, suggesting mechanisms underlying IBD patient avoidance of specific high-fiber foods. Please acknowledge all funding agencies by checking the applicable boxes below Other Please indicate your source of funding; Weston Family Foundation, MMSF, NSERC, CRC Disclosure of Interest None Declared

An Unusual Case of Lower Gastrointestinal Hemorrhage

Question: A 53-year-old woman, who was in good health, presented with hematochezia for more than 20 days. Examination was unremarkable, with stable vital signs. Laboratory tests revealed a hemoglobin of 78 g/L (normal 120–160 g/L), and the rest of the laboratory tests were normal. Colonoscopy revealed multiple masses with a cobblestone appearance, obvious mucosal congestion, and edema in the junction of sigmoid and rectum (Figure A). Colonic biopsy precipitated active bleeding that required various measures to stop bleeding. Ice-cold saline solution and 8% norepinephrine (8 mg norepinephrine in 100 mL saline solution) was used to rinse the bleeding site repeatedly and to constrict the vessels, but failed to stop the bleeding. Titanium clip was then used to clamp the vessels, but blood still exudated. Lauromacrogol was injected to stop the bleeding eventually (Figure A). She recovered following fluid resuscitation, acid suppression and somatostatin therapy. Contrast-enhanced computed tomography (CT) of the abdomen and pelvis is shown in Figure B–E. Three days later, she developed massive hematochezia with a hemoglobin level of 45 g/L. Owing to effective fluid resuscitation and blood transfusion, her blood pressure was relatively stable.

The ClC-2 Chloride Channel Activator, Lubiprostone, Improves Intestinal Barrier Function in Biopsies from Crohn's Disease but Not Ulcerative Colitis Patients.

The prostone analog, lubiprostone, is approved to manage constipation-predominant irritable bowel syndrome. Lubiprostone also protects intestinal mucosal barrier function in animal models of colitis. The aim of this study was to determine if lubiprostone improves barrier properties in isolated colonic biopsies from Crohn's disease (CD) and ulcerative colitis (UC) patients. Sigmoid colon biopsies from healthy subjects, CD and UC patients in remission, and CD patients with active disease were mounted in Ussing chambers. Tissues were treated with lubiprostone or vehicle to determine the effects on transepithelial electrical resistance (TER), FITC-dextran 4kD (FD4) permeability, and electrogenic ion transport responses to forskolin and carbachol. Localization of the tight junction protein, occludin, was determined by immunofluorescence. Lubiprostone significantly increased ion transport across control, CD and UC remission biopsies but not active CD. Lubiprostone selectively improved TER in both CD remission and active disease biopsies but not in control or UC biopsies. The improved TER was associated with increased membrane localization of occludin. Lubiprostone selectively improved barrier properties of biopsies from CD patients vs. UC and independent of an ion transport response. These data indicate that lubiprostone has potential efficacy in improving mucosal integrity in Crohn's disease.

Nadir Bir Kanlı Dışkılama Nedeni: Bir Olgu Sunumu

Tuberculosis, which is mainly caused by the mammalian tubercle bacilli, Mycobacterium tuberculosis complex, is life-threatening disease transmitted from human-tohuman via the airborne route. Gastrointestinal tract (GIT) tuberculosis is usually caused by swallowing infected sputum or spread of bacilli smears to the GIT. A 36-year-old male patient presented to our outpatient clinic with a one-year history of weight loss, abdominal pain, nausea, and bloody stools for the past three months. Colonoscopy revealed giant and mucopurulent exudates in the cecum, ileocecal valve, and ileum. On histopathological examination, both ileum and ascending colon biopsies showed multiple granuloma formations with caseous necrosis and multinuclear giant cells. The Ehrlich-Ziehl-Neelsen histochemical staining revealed multiple foci of acid-fast bacilli compatible with Mycobacterium tuberculosis. Chest X-ray showed bilateral infiltration of the upper zones. Acid-resistant bacilli were positive in the sputum smear test. The patient was diagnosed with GIT and pulmonary tuberculosis and appropriate treatment was initiated. This rare case highlights the importance of accurate diagnosis of tuberculosis and delayed diagnosis can cause the bacteria to infect other organs through blood, lymphatic system, or direct spread.

Dietary Calcium and Risk of Microscopic Colitis.

Microscopic colitis (MC) is an increasingly common cause of watery diarrhea particularly in older individuals. The role of diet in MC has received little study. We conducted a case-control study at a single institution enrolling patients referred for elective outpatient colonoscopy for diarrhea. Patients were classified as cases with MC or non-MC controls after a review of colon biopsies by 1 research pathologist. Study subjects were interviewed by a trained telephone interviewer using a validated food frequency questionnaire. Adherent microbes were evaluated from colonic biopsies using 16s rRNA sequencing. The study population included 106 cases with MC and 215 controls. Compared with controls, the cases were older, better educated, and more likely to be female. Cases with MC had lower body mass index and were more likely to have lost weight. Subjects in the highest quartile of dietary calcium intake had a lower risk of MC compared with those in the lowest quartile (adjusted odds ratio 0.22, 95% confidence interval 0.07-0.76). The findings were not explained by dairy intake, body mass index, or weight loss. We found that dietary calcium intake had significant associations with the abundance of Actinobacteria and Coriobacteriales in the microbial community of colonic biopsies. Compared with patients with diarrhea, cases with MC had a lower intake of dietary calcium. Diet can be associated with alterations in the gut microbiota and with luminal factors that could affect the risk of MC.

Human Colonoid–Myofibroblast Coculture for Study of Apical Na+/H+ Exchangers of the Lower Cryptal Neck Region

Cation and anion transport in the colonocyte apical membrane is highly spatially organized along the cryptal axis. Because of lack of experimental accessibility, information about the functionality of ion transporters in the colonocyte apical membrane in the lower part of the crypt is scarce. The aim of this study was to establish an in vitro model of the colonic lower crypt compartment, which expresses the transit amplifying/progenitor (TA/PE) cells, with accessibility of the apical membrane for functional study of lower crypt-expressed Na+/H+ exchangers (NHEs). Colonic crypts and myofibroblasts were isolated from human transverse colonic biopsies, expanded as three-dimensional (3D) colonoids and myofibroblast monolayers, and characterized. Filter-grown colonic myofibroblast-colonic epithelial cell (CM-CE) cocultures (myofibroblasts on the bottom of the transwell and colonocytes on the filter) were established. The expression pattern for ion transport/junctional/stem cell markers of the CM-CE monolayers was compared with that of nondifferentiated (EM) and differentiated (DM) colonoid monolayers. Fluorometric pHi measurements were performed to characterize apical NHEs. CM-CE cocultures displayed a rapid increase in transepithelial electrical resistance (TEER), paralleled by downregulation of claudin-2. They maintained proliferative activity and an expression pattern resembling TA/PE cells. The CM-CE monolayers displayed high apical Na+/H+ exchange activity, mediated to >80% by NHE2. Human colonoid-myofibroblast cocultures allow the study of ion transporters that are expressed in the apical membrane of the nondifferentiated colonocytes of the cryptal neck region. The NHE2 isoform is the predominant apical Na+/H+ exchanger in this epithelial compartment.