Inflammatory bowel disease (IBD) affects millions of people in the United States, with the number of diagnoses steadily rising. It has been associated with poor quality of life and a host of comorbidities. Most notably, IBD patients are at an increased risk of developing colorectal cancer (CRC). The American Gastroenterological Association (AGA) recommends that IBD patients with involvement of 1/3 or more of the colon undergo colonoscopy regularly to screen for CRC starting 8 years after initial IBD diagnosis. Colonoscopy techniques for IBD-related CRC screening are highly variable and differ widely between clinical practices. Currently, high-definition white-light colonoscopy (HD-WLC) and dye spraying chromoendoscopy (DCE) are both standard of care. The use of these technologies requires a high level of skill that is typically attained during clinicians’ 3-year gastroenterology (GI) fellowship. This study intends to compare outcomes of screening colonoscopies performed by GI fellows and attending physicians in patients with longstanding IBD (>8 years) and to assess the impact of GI fellow involvement on these procedures. Additionally, the current research intends to draw distinctions between HD-WLC and DCE procedures. The research was performed in the Division of Gastroenterology at Beth Israel Deaconess Medical Center (BIDMC) as part of a large randomized controlled trial (RCT) that aims to evaluate the comparative efficacy of HD-WLC and DCE. Patients were screened for study eligibility using relevant criteria and then randomized to undergo colonoscopy using HD-WLC technique or DCE technique. Data from 128 procedures were included in the study. Of these procedures, 59 (46.1%) were attending-performed procedures while 69 (53.9%) were fellow-performed, attending-supervised procedures. Of the attending-performed procedures, 30 (50.8%) were performed using the DCE technique and 29 (49.2%) were performed using the HD-WLC technique. Of the fellow-performed, attending-supervised procedures, 32 (46.4%) were performed using the DCE technique while 37 (53.6%) were performed using the HD-WLC technique. Fellow-performed, attending-supervised procedures were associated with longer total procedure time (TPT) and increased intra-procedure administration of sedation medications without superior lesion detection. Thus, fellows appear to be on par with attendings in terms of lesion detection but this level of proficiency comes at the cost of increased TPT. Assessing the short-term and long-term impacts of this could be a valuable area of future investigation. Also, DCE procedures took longer for all clinicians to perform, especially fellows, and are not associated with enhanced lesion detection. Further research is needed to understand the usefulness of DCE.

Great strides have been made with regard to neurogenesis in the enteric nervous system (ENS), rapidly following in the wake of recent revelations about the neurogenic properties of the central nervous system (CNS). As the ENS is more exposed, highly complex, and vulnerable to a variety of developmental, acquired, and multisystemic disorders, there is a sense of urgency for studies to address the potential within the gut to restore neurons that are injured or lost. It is the intricacies of the ENS and yet unclear relationships between agonists and embryonic precursors that have made demonstrating the arrival of new neurons in mature gut difficult under steady-state conditions. This thesis demonstrates that inducible models of a wide range of insults to the gut have yielded crucial information about ENS neurogenesis, while in vivo experimentation under steady-state conditions has proven inconsistent. Specifically, the signaling pathways of Ret and PTEN have revealed the existence of a ‘natural block’ that normally regulates neurogenesis and keeps proliferation well controlled. Furthermore, the overwhelming effects of serotonin agonism on neuron density in response to injury have uncovered an essential role of neuronal transdifferentiation by enteric glial cells that extends beyond what was once understood to be a largely homeostatic role. The influence of extrinsic innervation of the gut will also be explored, physiology of which is important for both the utility of gut microbiota and the role of Schwann cell progenitors in the development of the ENS. Therefore, this thesis will outline ENS organization and function, as well as describe common pathologies that serve as the foundation upon which neurogenesis is investigated. Critical inducible models to which chemical and molecular agonists are applied will be examined in detail, as it is through these models that therapeutics and biomedical engineering can be optimized in order to correct the pathophysiology of enteric neuropathies that as of now are still treated with surgical intervention.

Inflammatory Bowel Disease (IBD) is a chronic, idiopathic autoimmune disease characterized by the inflammation of the GI tract. The main subcategories of IBD include Crohn Disease (CD), ulcerative colitis (UC), and Indeterminate Colitis (IC). Currently, IBD is diagnosed and evaluated using clinical, endoscopic, biochemical, and histologic measures - which can be invasive and costly. Previous studies have shown that measurement of serum and fecal inflammatory biomarkers might be effective both for the assessment of intestinal infectious or inflammatory processes, as well as for gauging IBD disease activity. Inflammatory biomarkers investigated in this study include serum and fecal Anti-Saccharomyces-Cerevisiae Antibody (ASCA), serum and fecal lactoferrin, fecal calprotectin, fecal hemoglobin, IL1-𝛼, IL1-β, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). IMPACT-III questionnaires are utilized to measure the quality of life in enrolled subjects. Data collected in this study investigated the relationship between changes in serum and fecal biomarker levels, clinical disease activity, and the mental wellbeing of patients. The primary objective was to measure changes in inflammatory biomarker levels in patients with CD, UC, and IC after being treated with the anti-TNF therapy Infliximab (Remicade). The second objective is to study the relationship between changes in these biomarker levels and the clinical, biochemical, and endoscopic outcome parameters of IBD in patients. This is a multicenter, longitudinal, cohort study following 50 pediatric patients with IBD over the course of six Remicade infusion appointments. The project was conducted in partnership with Riley’s Children Hospital in Indianapolis. Patients with CD, UC, and IC were recruited for the study and stratified with respect to the temporal phase of their Remicade infusions, including: • Induction • Past induction, but less than 6 months • Those who have been receiving Remicade for over one year. A total of 58 eligible IBD patients are currently enrolled. 13 patients have withdrawn from the study, leaving 45 active patients: 27 CD, 17 UC, and 1 IC remaining in the prospective cohort. Patients provided serum and fecal samples and completed IMPACT-III questionnaires at the time of each Remicade infusion. Baseline serum ASCA levels were 0.014 ±0.029 OD from (n=15) patients with CD, 0.0083 ±0.022 OD in (n=12) patients with UC, and 0.002 OD in one patient with IC. Baseline fecal ASCA levels were 0.068 ±0.186 OD in (n=10) patients with CD, 0.0018 ±0.0013 OD in (n=9) patients with UC, and 0.001 OD in one patient with IC. At both baseline and at the time of the first infusion, CRP levels were significantly higher in patients with CD (p<0.05). At the time of the first infusion, the ESR in patients with CD was significantly higher than that in patients with UC (p<0.10). Serum lactoferrin was significantly higher in patients with UC at infusion 2 (p<0.05). ESR was significantly higher in patients with UC (p<0.10) at their fourth infusion. Our data support the hypothesis that serum and fecal biomarkers are useful in evaluating the response of intestinal inflammation to Remicade therapy. This study is ongoing, and further sample collection and data analysis are needed to more conclusively determine the accuracy of inflammatory biomarkers as a diagnostic tool for use in the diagnosis and interval assessment of patients with IBD.

Recent research has highlighted the connection between dysbiosis of the gut microbiome and its role in the development of Irritable Bowel Syndrome (IBS). Over the last few years, probiotics have grown in popularity as a potential treatment option in IBS. However, most current probiotic studies are limited due to small study populations, older median age, and short study time duration. The proposed study will be a multicenter, randomized, double-blinded placebo controlled study comparing the multi-strain probiotic Bifidobacterium infantis, Bifidobacterium bifidum, Bifidobacterium breve, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Escherichia coli DSM17252 to placebo in patients diagnosed with IBS based on Rome IV criteria over a 3-months duration. The study participants will have a baseline evaluation and a final evaluation at the end of the 3-months duration. The primary outcome will be the IBS Symptom Severity Score and the secondary outcomes will the individual components of the IBS Symptom Severity Score. The results of this study will begin to fill gaps in the current knowledge of the use of probiotics in the treatment of IBS.

京都大学 / 0048 / 新制・論文博士 / 博士(社会健康医学) / 乙第13196号 / 論社医博第12号 / 新制||社医||10(附属図書館) / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 福原 俊一, 教授 小泉 昭夫, 教授 佐藤 俊哉 / 学位規則第4条第2項該当 / Doctor of Public Health / Kyoto University / DFAM

Endoskopiska undersökningar har blivit vanligare och ökat i antal. Detta på grund av den  ökade livslängden. Möjligheten att behandla och att bota sjukdomar har också blivit bättre.  Screening av kolorektalcancer leder också till ett ökat antal patienter. De endoskopiska  undersökningarna har tidigare endast utförts av läkare. För att patienterna inte skall behöva  vänta för länge på undersökning har det införts endoskoperande sjuksköterskor runt om i  världen. Omvårdnaden runt de patienter som behöver genomgå endoskopiska undersökningar  är mycket viktig då undersökningarna kan upplevas som obehagliga och smärtsamma.    Syftet är att belysa vad som finns beskrivet angående patienttillfredsställelse och kvalité vid  endoskopiska undersökningar genomförda av sjuksköterskor.      Metod som valts till detta arbete är forskningsöversikt. Sammanlagt ingår 19 artiklar från  olika delar av världen.    Resultatet visar att patienttillfredsställelsen är god och att många patienter föredrar  endoskoperande sjuksköterskor. Kvalitén på undersökningarna var god och i jämförelse med  läkare är sjuksköterskor mer noggranna och finner flera avvikande fynd. Dock tar de  sjuksköterskeutförda undersökningarna längre tid i jämförelse med undersökningar utförda av  läkare.     Enligt denna forskningsöversikt har artiklarna i detta arbete visat att patienttillfredsställelsen  är god vid endoskopiska undersökningar genomförda av sjuksköterskor. Resultatet av denna  studie visar att sjuksköterskor genomför endoskopiska undersökningar med god kvalité och  med hög säkerhet för patienterna. Detta sammantaget med att väntetiderna för  undersökningarna kan kortas med hjälp av sjuksköterskor kan här ses en vinst för patienterna.

Hydrogen sulfide (H2S) has emerged as an important mediator of host function. In the gastrointestinal tract H2S is enzymatically produced and plays a vital role in cytoprotection, inflammation, and tissue repair. During a bout of colitis, the ability of the colon to produce H2S is markedly increased and drives the resolution of colitis. However, little is known about how the production of H2S is regulated in the colon and how dysregulated production can affect the course of colitis in vivo. Additionally, the mechanisms through which H2S can promote the resolution of colitis remain to be fully investigated. In Chapter 3 of this dissertation, the regulation of H2S production in the colon was explored by examining the contributions of three enzymatic pathways to colonic H2S synthesis. The largest source of the H2S synthesis was from a pathway previously unrecognized in the GI tract involving the enzyme 3-mercaptopyruvate sulfurtransferase (3MST). Additionally we found that the upregulation of H2S production during colitis occurred specifically at sites of mucosal ulceration. At the same time H2S inactivation via the enzyme sulfide quinone reductase (SQR) was significantly reduced at these sites. We propose that the site-specific alterations in H2S production and inactivation during colitis promote the resolution of inflammation and injury. Chapter 4 examined whether the ability of hyperhomocysteinemia (Hhcy) to exacerbate colonic inflammation occurred through impaired H2S synthesis. Hyperhomocysteinemia is often reported in patients with inflammatory bowel disease and is a consequence of decreased vitamin B intake. In all three models tested, diet-induced Hhcy significantly exacerbated colitis. Being dependent on vitamin B6 as a co-factor, the increased H2S production normally observed during colitis was abolished during Hhcy. Administration of an H2S donor to Hhcy rats significantly decreased the severity of colitis. These results also uncovered a novel role for IL-10 in promoting H2S production and homocysteine metabolism, which may have therapeutic value in conditions characterized by Hhcy. Finally, in Chapter 5 we looked for a mechanism through which H2S can promote resolution of colitis. Using CSE-deficient mice we found that H2S production was required to maintain HIF-1α signaling in the colon. Additionally, proper HIF-1α signaling was required for H2S-donating molecules to promote the resolution of colitis. These results suggest that HIF-1α signaling is a critical event through which H2S promotes resolution of colitis. Collectively, these chapters further highlight the importance of H2S production in colon during inflammation and injury and offer insight into new therapeutic targets mediated through H2S. / Dissertation / Doctor of Philosophy (PhD)

Introduction: The incidence of adenocarcinoma of the esophagus has increased dramatically in the past three decades. Esophageal cancer is the eighth most common cancer and sixth leading cause of cancer death. Squamous cell cancer is the most common type of esophageal cancer all over the world, but the incidence of esophageal adenocarcinoma has been increasing. Most, if not all, esophageal adenocarcinomas arise from a region of Barrett's metaplasia. The most common location is near the EG junction with an association of endoscopic evidence of Barrett's esophagus. We present a case of young male presented with lower extremity pain and swelling due to metastasis of undiagnosed primary esophageal cancer. Case Presentation: A 36-year-old male with no significant medical history presented with complaints of lower extremity pain and swelling. Patient denied any other symptoms. On admission, vital signs were temp. 97.8, BP 145/87 mmhg, HR 75 bpm, RR was 18. Labs work showed Na 141, K 3.7, BUN 17, Cr 0.70, Alkaline phosphatase 263, AST 14, ALT 9, CHOL 202, HDL 27, Triglyc 285, Hgb 12.4, Plt 244, Wbc 9.6, ESR 28, TSH 7.07, Vit D (25 hydroxy) 8, Hgb A1c 7.0, CRP 102.6. Knee x-ray was highly suspicious for chronic osteomyelitis vs. neoplastic lesion. Doppler US of lower extremity ruled out DVT, but showed large complex fluid collection anterior to the knee and proximal leg measuring 8.0 x 5.8 x 18.6 cm with concern for osteomyelitis with overlying abscess vs an aggressive primary bone tumor. Patient was started on antibiotics and had a MRI that showed periostitis with possible differential of osteomyelitis/periostitis and osteosarcoma. CT scan of chest, abdomen and pelvis showed aortocaval and left iliac lymphadenopathy concerning for metastasis. Blood cultures were negative but biopsy was consistent with metastatic adenocarcinoma favoring gastrointestinal and pancreaticobiliary tract as the primary source. Patient had an upper endoscopy that showed esophageal mass extended from the GE junction up about 7cm. Chemotherapy and radiation therapy were initiated. HER-2 gene was ordered. Patient developed cardiopulmonary arrest and died prior to discharge. Discussion: Adenocarcinoma of the esophagus is usually associated with Barrett's esophagus that involves the lower third of esophagus. It is a very aggressive disease associated with diffuse metastasis and high mortality rate. The most common metastatic sites for esophageal cancer are liver brain and lung. Risk factors associated with cancer are smoking, higher body mass index, gastroesophageal reflux disease, and a diet low in fruits and vegetables. Almost half of the cases of adenocarcinoma have no associated reflux disease. The median survival rate of metastatic esophageal cancer is 4-9 months. Physicians should always think of visceral malignancy in cases of biopsy proven adenocarcinoma for better prognosis. Endoscopy should always be done to look for visceral malignancy if cancer is suspected.

NOD2 is an intracellular innate immune receptor expressed in dendritic cells and gastrointestinal epithelial cells. Polymorphisms in the NOD2 gene convey a strong predisposition to Crohn’s disease (CD), a form of inflammatory bowel disease. Understanding the function of NOD2, and in what way it is aberrant in the presence of NOD2 polymorphisms, would confer a valuable paradigm for understanding Crohn’s pathogenesis. CD is thought to arise both from defects in the gut mucosal barrier and from a dysregulated Th17 immune response to commensal gut flora. Aberrant expression of IL-23 is present in both human CD and in murine models of colitis. Wild-type NOD2 contributes to NFκB activation and pro-inflammatory cytokine production on recognition of its cognate ligand, a function that is lost in CD-associated mutations. How the predominantly loss-of-function CD-NOD2 contributes to the pro-inflammatory response present in Crohn’s is not yet understood. In this thesis a set of experiments is described that aim to shed light on the function of NOD2, firstly through identification of negative regulators of immune activation that are dependent on NOD2 for their expression. This work identifies the microRNAs that are expressed following NOD2 triggering in human dendritic cells. Specifically, up-regulation of the miR-29 family was found to be dependent on wild-type NOD2 function. A number of novel miR-29 targets and their functional consequences are presented, including the cytokine subunits IL-12p40 and IL-23p19, directly linking NOD2 polymorphisms and aberrant IL-23 expression. Secondly, a project aiming to identify components of the NOD2 signalling complex (or signalosome) is described. To this end I employed a model system that involved tagging NOD2, and stable expression in a human cell line. These clones were validated for expression and function before an immunoprecipitation protocol was optimised. Mass spectrometry analysis of these samples identified the known NOD2-interacting protein Erbin.

The aetiology of IBD is unknown, but available evidence suggests that an aberrant immune response towards the commensal microbial flora is responsible for intestinal inflammation in genetically susceptible individuals. Studies from animal models of intestinal inflammation have greatly advanced our understanding of the immunological basis of IBD. However, translation of results from animal research into human studies is essential in order to improve treatment options and patient quality of life. In this thesis we present the successful introduction of translational studies on human tissue in our laboratory. In particular, we evaluated the role of the IL23/IL17 pathway in the human immune response and its role in IBD. IL23-driven inflammation has been primarily linked to its activity on Th-17 cells; however, work from our laboratory has identified a novel population of IL23-responsive ILC, which are responsible for innate colitis in mice. Here we have analyzed the role of IL23-responsive innate cells in IBD. Our results show increased expression of Th-17 signature genes amongst intestinal CD3- cells in patients with IBD. Furthermore, we observed a marked and selective increase in IL17 producing CD56- ILC in the inflamed intestine of patients with CD. ILC may contribute to intestinal inflammation through secretion of cytokines, such as IL17A and IL17F, and recruitment of other inflammatory cells, representing a novel tissue-specific target for the treatment of IBD. In addition, we present here our preliminary data on the characterization of human intestinal and systemic DC populations. In particular, we aimed to evaluate if in the context of the intestinal microenvironment DC develop specific regulatory features, as observed in murine CD103+ DC. We show that human intestinal DC populations exhibit specific regulatory properties, such as expression of genes associated with TGF-β and RA activity. Furthermore, CD103+ DC are present in the human gut and are characterized by tolerogenic markers. Remarkably, patients with IBD have reduced frequencies of intestinal CD103+ DC, which display a more pro-inflammatory phenotype. Alteration in DC subset composition and functional activity may result in a distort balance between immune effector and regulatory responses, promoting the development of intestinal inflammation.