Early life exposure to broccoli sprouts confers stronger protection against enterocolitis development in an immunological mouse model of inflammatory bowel disease

IMPORTANCE

To our knowledge, IL-10-KO mice have not previously been used to investigate the interactions of host, microbiota, and broccoli, broccoli sprouts, or broccoli bioactives in resolving symptoms of CD. We showed that a diet containing 10% raw broccoli sprouts increased the plasma concentration of the anti-inflammatory compound sulforaphane and protected mice to varying degrees against disease symptoms, including weight loss or stagnation, fecal blood, and diarrhea. Younger mice responded more strongly to the diet, further reducing symptoms, as well as increased gut bacterial richness, increased bacterial community similarity to each other, and more location-specific communities than older mice on the diet intervention. Crohn's disease disrupts the lives of patients and requires people to alter dietary and lifestyle habits to manage symptoms. The current medical treatment is expensive with significant side effects, and a dietary intervention represents an affordable, accessible, and simple strategy to reduce the burden of symptoms.

Steamed broccoli sprouts alleviate DSS-induced inflammation and retain gut microbial biogeography in mice

IMPORTANCE

Evaluating bacterial communities across different locations in the gut provides a greater insight than fecal samples alone and provides an additional metric by which to evaluate beneficial host-microbe interactions. Here, we show that 10% steamed broccoli sprouts in the diet protects mice from the negative effects of dextran sodium sulfate-induced colitis, that colitis erases biogeographic patterns of bacterial communities in the gut, and that the cecum is not likely to be a significant contributor to colonic bacteria of interest in the DSS mouse model of ulcerative colitis. Mice fed the broccoli sprout diet during colitis performed better than mice fed the control diet while receiving DSS. The identification of accessible dietary components and concentrations that help maintain and correct the gut microbiome may provide universal and equitable approaches to IBD prevention and recovery, and broccoli sprouts represent a promising strategy.

Early life exposure to broccoli sprouts confers stronger protection against enterocolitis development in an immunological mouse model of inflammatory bowel disease

Crohn's Disease (CD) is a presentation of Inflammatory Bowel Disease (IBD) that manifests in childhood and adolescence, and involves chronic and severe enterocolitis, immune and gut microbiome dysregulation, and other complications. Diet and gut-microbiota-produced metabolites are sources of anti-inflammatories which could ameliorate symptoms. However, questions remain on how IBD influences biogeographic patterns of microbial location and function in the gut, how early life transitional gut communities are affected by IBD and diet interventions, and how disruption to biogeography alters disease mediation by diet components or microbial metabolites. Many studies on diet and IBD use a chemically induced ulcerative colitis model, despite the availability of an immune-modulated CD model. Interleukin-10-knockout (IL-10-KO) mice on a C57BL/6 background, beginning at age 4 or 7 weeks, were fed a control diet or one containing 10% (w/w) raw broccoli sprouts, which was high in the sprout-sourced anti-inflammatory sulforaphane. Diets began 7 days prior to, and for 2 weeks after inoculation with Helicobacter hepaticus, which triggers Crohn's-like symptoms in these immune-impaired mice. The broccoli sprout diet increased sulforaphane in plasma; decreased weight stagnation, fecal blood, and diarrhea associated; and increased microbiota richness in the gut, especially in younger mice. Sprout diets resulted in some anatomically specific bacteria in younger mice, and reduced the prevalence and abundance of pathobiont bacteria which trigger inflammation in the IL-10-KO mouse, for example; Escherichia coli and Helicobacter. Overall, the IL-10-KO mouse model is responsive to a raw broccoli sprout diet and represents an opportunity for more diet-host-microbiome research.

Steamed broccoli sprouts alleviate DSS-induced inflammation and retain gut microbial biogeography in mice

Inflammatory Bowel Diseases (IBD) are devastating conditions of the gastrointestinal tract with limited treatments, and dietary intervention may be effective, and affordable, for managing symptoms. Glucosinolate compounds are highly concentrated in broccoli sprouts, especially glucoraphanin, and can be metabolized by certain mammalian gut bacteria into anti inflammatory isothiocyanates, such as sulforaphane. Gut microbiota exhibit biogeographic patterns, but it is unknown if colitis alters these or whether the location of glucoraphanin metabolizing bacteria affects anti-inflammatory benefits. We fed specific pathogen free C57BL/6 mice either a control diet or a 10% steamed broccoli sprout diet, and gave a three-cycle regimen of 2.5% dextran sodium sulfate (DSS) in drinking water over a 34-day experiment to simulate chronic, relapsing ulcerative colitis. We monitored body weight, fecal characteristics, lipocalin, serum cytokines, and bacterial communities from the luminal and mucosa-associated populations in the jejunum, cecum, and colon. Mice fed the broccoli sprout diet with DSS treatment performed better than mice fed the control diet with DSS, including significantly more weight gain, lower Disease Activity Indexes, lower plasma lipocalin and proinflammatory cytokines, and higher bacterial richness in all gut locations. Bacterial communities were assorted by gut location, but were more homogenous across locations in the control diet + DSS mice. Importantly, our results showed that broccoli sprout feeding abrogated the effects of DSS on gut microbiota, as bacterial richness and biogeography were similar between mice receiving broccoli sprouts with and without DSS. Collectively, these results support the protective effect of steamed broccoli sprouts against dysbiosis and colitis induced by DSS.

Importance

Evaluating bacterial communities across different locations in the gut provides a greater insight than fecal samples alone, and provides an additional metric by which to evaluate beneficial host-microbe interactions. Here, we show that 10% steamed broccoli sprouts in the diet protects mice from the negative effects of dextran sodium sulfate induced colitis, that colitis erases biogeographical patterns of bacterial communities in the gut, and that the cecum is not likely to be a significant contributor to colonic bacteria of interest in the DSS mouse model of ulcerative colitis. Mice fed the broccoli sprout diet during colitis performed better than mice fed the control diet while receiving DSS. The identification of accessible dietary components and concentrations that help maintain and correct the gut microbiome may provide universal and equitable approaches to IBD prevention and recovery, and broccoli sprouts represent a promising strategy.

Interplay of broccoli/broccoli sprout bioactives with gut microbiota in reducing inflammation in inflammatory bowel diseases

Inflammatory Bowel Diseases (IBD) are chronic, reoccurring, and debilitating conditions characterized by inflammation in the gastrointestinal tract, some of which can lead to more systemic complications and can include autoimmune dysfunction, a change in the taxonomic and functional structure of microbial communities in the gut, and complicated burdens in a person's daily life. Like many diseases based in chronic inflammation, research on IBD has pointed towards a multifactorial origin involving factors of the person's lifestyle, immune system, associated microbial communities, and environmental conditions. Treatment currently exists only as palliative care, and seeks to disrupt the feedback loop of symptoms by reducing inflammation and allowing as much of a return to homeostasis as possible. Various anti-inflammatory options have been explored, and this review focuses on the use of diet as an alternative means of improving gut health. Specifically, we highlight the connection between the role of sulforaphane from cruciferous vegetables in regulating inflammation and in modifying microbial communities, and to break down the role they play in IBD.

Introducing the Microbes and Social Equity Working Group: Considering the Microbial Components of Social, Environmental, and Health Justice

Humans are inextricably linked to each other and our natural world, and microorganisms lie at the nexus of those interactions. Microorganisms form genetically flexible, taxonomically diverse, and biochemically rich communities, i.e., microbiomes that are integral to the health and development of macroorganisms, societies, and ecosystems. Yet engagement with beneficial microbiomes is dictated by access to public resources, such as nutritious food, clean water and air, safe shelter, social interactions, and effective medicine. In this way, microbiomes have sociopolitical contexts that must be considered. The Microbes and Social Equity (MSE) Working Group connects microbiology with social equity research, education, policy, and practice to understand the interplay of microorganisms, individuals, societies, and ecosystems. Here, we outline opportunities for integrating microbiology and social equity work through broadening education and training; diversifying research topics, methods, and perspectives; and advocating for evidence-based public policy that supports sustainable, equitable, and microbial wealth for all.

Dynamic Colonization of Microbes and Their Functions after Fecal Microbiota Transplantation for Inflammatory Bowel Disease

For fecal microbiota transplantation (FMT) to be successful in immune diseases like inflammatory bowel disease, it is assumed that therapeutic microbes and their beneficial functions and immune interactions must colonize a recipient patient and persist in sufficient quantity and for a sufficient period of time to produce a clinical benefit. Few studies, however, have comprehensively profiled the colonization and persistence of transferred microbes along with the transfer of their microbial functions and interactions with the host immune system. Using 16S, metagenomic, and immunoglobulin A (IgA) sequencing, we analyzed hundreds of longitudinal microbiome samples from a randomized controlled trial of 12 patients with ulcerative colitis who received fecal transplant or placebo for 12 weeks. We uncovered diverse competitive dynamics among donor and patient strains, showing that persistence of transferred microbes is far from static. Indeed, one patient experienced a dramatic loss of donor bacteria 10 weeks into the trial, coinciding with a bloom of pathogenic bacteria and worsening symptoms. We evaluated the transfer of microbial functions, including desired ones, such as butyrate production, and unintended ones, such as antibiotic resistance. By profiling bacteria coated with IgA, we identified bacteria associated with inflammation and found that microbial interactions with the host immune system can be transferred across people, which could play a role in gut microbiome therapeutics for immune-related diseases. Our findings shed light on the colonization dynamics of gut microbes and their functions in the context of FMT to treat a complex disease-information that may provide a foundation for developing more-targeted therapeutics. IMPORTANCE Fecal microbiota transplantation (FMT)-transferring fecal microbes from a healthy donor to a sick patient-has shown promise for gut diseases such as inflammatory bowel disease. Unlike pharmaceuticals, however, fecal transplants are complex mixtures of living organisms, which must then interact with the microbes and immune system of the recipient. We sought to understand these interactions by tracking the microbes of 12 inflammatory bowel disease patients who received fecal transplants for 12 weeks. We uncovered a range of dynamics. For example, one patient experienced successful transfer of donor bacteria, only to lose them after 10 weeks. We similarly evaluated transfer of microbial functions, including how they interacted with the recipient's immune system. Our findings shed light on the colonization dynamics of gut microbes, as well as their functions in the context of FMT-information that may provide a critical foundation for the development of more-targeted therapeutics.

Daily, oral FMT for long-term maintenance therapy in ulcerative colitis: results of a single-center, prospective, randomized pilot study

Background

Fecal microbiota transplantation (FMT) is a promising new strategy in the treatment of Inflammatory Bowel Disease, but long-term delivery systems are lacking. This randomized study was designed as a safety and feasibility study of long-term FMT in subjects with mild to moderate UC using frozen, encapsulated oral FMT (cFMT).

Methods

Subjects were randomized 1:1 to receive FMT induction by colonoscopy, followed by 12 weeks of daily oral administration of frozen encapsulated cFMT or sham therpay. Subjects were followed for 36 weeks and longitudenal clinical assessments included multiple subjective and objective markers of disease severity. Ribosomal 16S bacterial sequencing was used to assess donor-induced changes in the gut microbiota. Changes in T regulatory (Treg) and mucosal associated invariant T (MAIT) cell populations were evaluated by flow cytometry as an exploratory endpoint.

Results

Twelve subjects with active UC were randomized: 6 subjects completed the full 12-week course of FMT plus cFMT, and 6 subjects received sham treatment by colonic installation and longitudinal oral placebo capules. Chronic administration of cFMT was found to be safe and well-tolerated but home storage concerns exist. Protocol adherence was high, and none of the study subjects experienced FMT-associated treatment emergent adverse events. Two subjects that received cFMT achieved clinical remission versus none in the placebo group (95% CI = 0.38-infinity, p = 0.45). cFMT was associated with sustained donor-induced shifts in fecal microbial composition. Changes in MAIT cell cytokine production were observed in cFMT recipients and correlated with treatment response.

Conclusion

These pilot data suggest that daily encapsulated cFMT may extend the durability of index FMT-induced changes in gut bacterial community structure and that an association between MAIT cell cytokine production and clinical response to FMT may exist in UC populations. Oral frozen encapsulated cFMT is a promising FMT delivery system and may be preferred for longterm treatment strategies in UC and other chronic diseases but further evaluations will have to address home storage concerns. Larger trials should be done to explore the benefits of cFMT and to determine its long-term impacts on the colonic microbiome. Trial registration: ClinicalTrials.gov (NCT02390726). Registered 17 March 2015, https://clinicaltrials.gov/ct2/show/NCT02390726?term=NCT02390726&draw=2&rank=1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01856-9.

Epidemiology and outcomes of gastroparesis, as documented in general practice records, in the United Kingdom

OBJECTIVE

To generate real-world evidence for the epidemiology of gastroparesis in the UK, we evaluated the prevalence, incidence, patient characteristics and outcomes of gastroparesis in the Clinical Practice Research Datalink (CPRD) database.

DESIGN

This was a retrospective, cross-sectional study. Prevalence and incidence of gastroparesis were evaluated in the CPRD database, with linkage to Hospital Episodes Statistics Admitted Patient Care and Office for National Statistics mortality data. Prevalence and incidence were age and sex standardised to mid-2017 UK population estimates. Descriptive analyses of demographics, aetiologies, pharmacological therapies and mortality were conducted.

RESULTS

Standardised prevalence of gastroparesis, as documented in general practice records, was 13.8 (95% CI 12.6 to 15.1) per 100 000 persons in 2016, and standardised incidence of gastroparesis rose from 1.5 (95% CI 1.1 to 1.8) per 100 000 person-years in 2004 to 1.9 (95% CI 1.4 to 2.3) per 100 000 person-years in 2016. The most common disease aetiologies were idiopathic (39.4%) and diabetic gastroparesis (37.5%), with a similar distribution of type 1 and type 2 diabetes among the 90% who had type of diabetes documented. Patients with diabetic gastroparesis had a significantly higher risk of mortality than those with idiopathic gastroparesis after diagnosis (adjusted HR 1.9, 95% CI 1.2 to 3.0). Of those with gastroparesis, 31.6% were not offered any recognised pharmacological therapy after diagnosis.

CONCLUSION

This is, to our knowledge, the first population-based study providing data on epidemiology and outcomes of gastroparesis in Europe. Further research is required to fully understand the factors influencing outcomes and survival of patients with gastroparesis.

Invertible promoters mediate bacterial phase variation, antibiotic resistance, and host adaptation in the gut

Phase variation, the reversible alternation between genetic states, enables infection by pathogens and colonization by commensals. However, the diversity of phase variation remains underexplored. We developed the PhaseFinder algorithm to quantify DNA inversion-mediated phase variation. A systematic search of 54,875 bacterial genomes identified 4686 intergenic invertible DNA regions (invertons), revealing an enrichment in host-associated bacteria. Invertons containing promoters often regulate extracellular products, underscoring the importance of surface diversity for gut colonization. We found invertons containing promoters regulating antibiotic resistance genes that shift to the ON orientation after antibiotic treatment in human metagenomic data and in vitro, thereby mitigating the cost of antibiotic resistance. We observed that the orientations of some invertons diverge after fecal microbiota transplant, potentially as a result of individual-specific selective forces.

Randomized trial in malignant biliary obstruction: Plastic vs partially covered metal stents

AIM: To compare efficacy and complications of partially covered self-expandable metal stent (pcSEMS) to plastic stent (PS) in patients treated for malignant, infrahilar biliary obstruction.

METHODS: Multicenter prospective randomized clinical trial with treatment allocation to a pcWallstent^® (SEMS) or a 10 French PS. Palliative patients aged ≥ 18, for infrahilar malignant biliary obstruction and a Karnofsky performance scale index > 60% from 6 participating North American university centers. Primary endpoint was time to stent failure, with secondary outcomes of death, adverse events, Karnofsky performance score and short-form-36 scale administered on a three-monthly basis for up to 2 years. Survival analyses were performed for stent failure and death, with Cox proportional hazards regression models to determine significant predictive characteristics.

RESULTS: Eighty-five patients were accrued over 37 mo, 42 were randomized to the SEMS group and 83 patients were available for analyses. Time to stent failure was 385.3 ± 52.5 d in the SEMS and 153.3 ± 19.8 d in the PS group, P = 0.006. Time to death did not differ between groups (192.3 ± 23.4 d for SEMS vs 211.5 ± 28.0 d for PS, P = 0.70). The only significant predictor was treatment allocation, relating to the time to stent failure (P = 0.01). Amongst other measured outcomes, only cholangitis differed, being more common in the PS group (4.9% vs 24.5%, P = 0.029). The small number of patients in follow-up limits longitudinal assessments of performance and quality of life. From an initially planned 120 patients, only 85 patients were recruited.

CONCLUSION: Partially covered SEMS result in a longer duration till stent failure without increased complication rates, yet without accompanying measurable benefits in survival, performance, or quality of life.

Activation of colonic mucosal 5-HT(4) receptors accelerates propulsive motility and inhibits visceral hypersensitivity

BACKGROUND & AIMS

5-hydroxytryptamine receptor (5-HT(4)R) agonists promote gastrointestinal motility and attenuate visceral pain, but concerns about adverse reactions have restricted their availability. We tested the hypotheses that 5-HT(4) receptors are expressed in the colonic epithelium and that 5-HT(4)R agonists can act intraluminally to increase motility and reduce visceral hypersensitivity.

METHODS

Mucosal expression of the 5-HT(4)R was evaluated by reverse-transcriptase polymerase chain reaction and immunohistochemical analysis of tissues from 5-HT(4)R(BAC)-enhanced green fluorescent protein mice. Amperometry, histology, and short-circuit current measurements were used to study 5-HT, mucus, and Cl(-) secretion, respectively. Propulsive motility was measured in guinea pig distal colon, and visceromotor responses were recorded in a rat model of colonic hypersensitivity. 5-HT(4)R compounds included cisapride, tegaserod, naronapride, SB204070, and GR113808.

RESULTS

Mucosal 5-HT(4) receptors were present in the small and large intestines. In the distal colon, 5-HT(4) receptors were expressed by most epithelial cells, including enterochromaffin and goblet cells. Stimulation of 5-HT(4)Rs evoked mucosal 5-HT release, goblet cell degranulation, and Cl(-) secretion. Luminal administration of 5-HT(4)R agonists accelerated propulsive motility; a 5-HT(4)R antagonist blocked this effect. Bath application of 5-HT(4)R agonists did not affect motility. Oral or intracolonic administration of 5-HT(4)R agonists attenuated visceral hypersensitivity. Intracolonic administration was more potent than oral administration, and was inhibited by a 5-HT(4)R antagonist.

CONCLUSIONS

Mucosal 5-HT(4) receptor activation can mediate the prokinetic and antinociceptive actions of 5-HT(4)R agonists. Colon-targeted, intraluminal delivery of 5-HT(4)R agonists might be used to promote motility and alleviate visceral pain, while restricting systemic bioavailability and resulting adverse side effects.

Endoscopic occlusion of cystic duct using N-butyl cyanoacrylate for postoperative bile leakage

Bile leak after cholecystectomy is well described, with the cystic duct remnant the site of the leak in the majority of cases. Endoscopic retrograde cholangiopancreatography (ERCP) with biliary stent placement has a high success rate in such cases. When ERCP fails, options include surgery, and percutaneous and endoscopic transcatheter occlusion of the site of bile leak. Here, we describe a case of endoscopic transcatheter occlusion of a persistent cystic duct bile leak after cholecystectomy using N-butyl cyanoacrylate glue. A 51-year-old man had persistent pain and bilious drainage following a laparoscopic cholecystectomy. The bile leak persisted after endoscopic placement of a biliary stent for a confirmed cystic duct leak. A repeat ERCP was carried out and the cystic duct was occluded with a combination of angiographic coils and N-butyl cyanoacrylate glue. The patient's pain and bilious drainage resolved. A follow-up cholangiogram confirmed complete resolution of the cystic duct leak and a patent common bile duct.

Review article: intestinal serotonin signalling in irritable bowel syndrome

Alterations in motility, secretion and visceral sensation are hallmarks of irritable bowel syndrome. As all of these aspects of gastrointestinal function involve serotonin signalling between enterochromaffin cells and sensory nerve fibres in the mucosal layer of the gut, potential alterations in mucosal serotonin signalling have been explored as a possible mechanism of altered function and sensation in irritable bowel syndrome. Literature related to intestinal serotonin signalling in normal and pathophysiological conditions has been searched and summarized. Elements of serotonin signalling that are altered in irritable bowel syndrome include: enterochromaffin cell numbers, serotonin content, tryptophan hydroxylase message levels, 5-hydroxyindoleacedic acid levels, serum serotonin levels and expression of the serotonin-selective reuptake transporter. Both genetic and epigenetic factors could contribute to decreased serotonin-selective reuptake transporter in irritable bowel syndrome. A serotonin-selective reuptake transporter gene promoter polymorphism may cause a genetic predisposition, and inflammatory mediators can induce serotonin-selective reuptake transporter downregulation. While a psychiatric co-morbidity exists with IBS, changes in mucosal serotonin handling support the concept that there is a gastrointestinal component to the aetiology of irritable bowel syndrome. Additional studies will be required to gain a more complete understanding of changes in serotonin signalling that are occurring, their cause and effect relationship, and which of these changes have pathophysiological consequences.

Review article: intestinal serotonin signalling in irritable bowel syndrome

Alterations in motility, secretion and visceral sensation are hallmarks of irritable bowel syndrome. As all of these aspects of gastrointestinal function involve serotonin signalling between enterochromaffin cells and sensory nerve fibres in the mucosal layer of the gut, potential alterations in mucosal serotonin signalling have been explored as a possible mechanism of altered function and sensation in irritable bowel syndrome. Literature related to intestinal serotonin signalling in normal and pathophysiological conditions has been searched and summarized. Elements of serotonin signalling that are altered in irritable bowel syndrome include: enterochromaffin cell numbers, serotonin content, tryptophan hydroxylase message levels, 5-hydroxyindoleacedic acid levels, serum serotonin levels and expression of the serotonin-selective reuptake transporter. Both genetic and epigenetic factors could contribute to decreased serotonin-selective reuptake transporter in irritable bowel syndrome. A serotonin-selective reuptake transporter gene promoter polymorphism may cause a genetic predisposition, and inflammatory mediators can induce serotonin-selective reuptake transporter downregulation. While a psychiatric co-morbidity exists with IBS, changes in mucosal serotonin handling support the concept that there is a gastrointestinal component to the aetiology of irritable bowel syndrome. Additional studies will be required to gain a more complete understanding of changes in serotonin signalling that are occurring, their cause and effect relationship, and which of these changes have pathophysiological consequences.

Inflammatory neuropathies of the enteric nervous system

Inflammatory neuropathy of the enteric nervous system is emerging as an important topic in the field of neurogastroenterology. Enteric ganglionitis can be either primary or secondary to a wide array of diseases (i.e., paraneoplastic, infectious, and neurological disorders) and is characterized by a dense infiltrate of inflammatory/immune cells mainly confined to the neural microenvironment. The clinical picture reflects the involved segment of the gastrointestinal tract (achalasia, gastroparesis, pseudo-obstruction, and megacolon). In these settings, symptoms may develop either acutely (frequently after a flulike episode in otherwise previously healthy individuals) or more slowly (e.g., in paraneoplastic syndromes). The inflammatory/immune response in enteric ganglionitis leads to neuronal dysfunction and degeneration over time and sometimes results in a complete loss of enteric neurons. The diagnosis of enteric ganglionitis is supported by detection of circulating antineuronal antibodies against select molecular targets, including Hu and Yo proteins, neurotransmitter receptors, and ion channels. Potential mechanisms involved in neuronal dysfunction include viral antigen expression in the enteric neural environment, molecular mimicry (onconeural antigens), and the role exerted by cellular and humoral autoimmunity. A short course of steroid or other immunosuppressive therapy has been shown to be helpful in the treatment of these conditions. This feature reinforces the concept of a cause/effect relationship of the immune-mediated insult damaging the enteric innervation. An increased awareness of the clinical features and the immunologic and neurodegenerative mechanisms of these forms of peripheral neuropathy is important to correctly diagnose this problem during the early stages of the disease process and to provide appropriate immunosuppressive therapies.

Molecular defects in mucosal serotonin content and decreased serotonin reuptake transporter in ulcerative colitis and irritable bowel syndrome

BACKGROUND & AIMS

Serotonin (5-HT) is a critical signaling molecule in the gut. 5-HT released from enterochromaffin cells initiates peristaltic, secretory, vasodilatory, vagal, and nociceptive reflexes. Despite being pathophysiologically divergent, ulcerative colitis (UC) and irritable bowel syndrome (IBS) are both associated with clinical symptoms that include alterations in the normal patterns of motility, secretion, and sensation. Our aim was to test whether enteric 5-HT signaling is defective in these disorders.

METHODS

Rectal biopsy specimens were obtained from healthy controls and patients with UC, IBS with diarrhea (IBS-D), and IBS with constipation (IBS-C). Key elements of 5-HT signaling, including measures of 5-HT content, release, and reuptake, were analyzed with these samples.

RESULTS

Mucosal 5-HT, tryptophan hydroxylase 1 messenger RNA, serotonin transporter messenger RNA, and serotonin transporter immunoreactivity were all significantly reduced in UC, IBS-C, and IBS-D. The enterochromaffin cell population was decreased in severe UC samples but was unchanged in IBS-C and IBS-D. When 5-HT release was investigated under basal and mechanical stimulation conditions, no changes were detected in any of the groups relative to controls.

CONCLUSIONS

These data show that UC and IBS are associated with similar molecular changes in serotonergic signaling mechanisms. While UC and IBS have distinct pathophysiologic properties, these data suggest that shared defects in 5-HT signaling may underlie the altered motility, secretion, and sensation. These findings represent the first demonstration of significant molecular alterations specific to the gut in patients with IBS and support the assertion that disordered gastrointestinal function in IBS involves changes intrinsic to the bowel.

Enterochromaffin cells and 5-HT signaling in the pathophysiology of disorders of gastrointestinal function

Disorders of gastrointestinal function are common and significantly reduce quality-of-life, as well as negatively impacting healthcare costs. Consequently, there is much interest in understanding the pathogenesis of these disorders. Increasing, albeit as yet limited, evidence has implicated alterations in 5-hydroxytryptamine (5-HT) release, and the subsequent interaction of 5-HT with specific 5-HT receptor subtypes, in the altered gut function of patients with irritable bowel syndrome (IBS) and other functional bowel diseases. Alterations to enterochromaffin cells and/or 5-HT signaling can result in gastrointestinal dysmotility, visceral hypersensitivity and secretomotor abnormalities in the gut. Evidence is beginning to link disturbed 5-HT physiology with the pathophysiology of diarrhea and constipation in IBS, and with slow-transit constipation. This review discusses the current evidence on the pathobiology of these systems.

Antineuronal antibodies in idiopathic achalasia and gastro-oesophageal reflux disease

BACKGROUND AND AIMS

The precise aetiology of achalasia is unknown although autoimmunity has been implicated and is supported by several studies. We screened sera from patients with achalasia or gastro-oesophageal reflux disease (GORD) to test for circulating antimyenteric neuronal antibodies.

METHODS

Serum was obtained from 45 individuals with achalasia, 16 with GORD, and 22 normal controls. Serum was used in immunohistochemistry to label whole mount preparations of ileum and oesophagus of the guinea pig and mouse. Also, sections of superior cervical and dorsal root ganglia, and spinal cord were examined.

RESULTS

Positive immunostaining of the myenteric plexus was detected in significantly more achalasia and GORD samples than control samples (achalasia, p<0.001; GORD, p<0.01), and immunoreactivity was significantly more intense with achalasia and GORD serum samples than controls (achalasia, p<0.01; GORD, p<0.05). There was no correlation between intensity of immunoreactivity and duration of achalasia symptoms. In most cases, achalasia and GORD sera stained all ileal submucosal and myenteric neurones, and oesophageal neurones. Immunostaining was not species specific; however, immunostaining was largely specific for enteric neurones. Western blot analysis failed to reveal specific myenteric neuronal proteins that were labelled by antibodies in achalasia or GORD serum.

CONCLUSIONS

These data suggest that antineuronal antibodies are generated in response to tissue damage or some other secondary phenomenon in achalasia and GORD. We conclude that antineuronal antibodies found in the serum of patients with achalasia represent an epiphenomenon and not a causative factor.

Mycotic arch aneurysm and aortoesophageal fistula in a patient with melioidosis

Aortoesophageal fistula due to an aortic arch aneurysm is a rare entity with an extremely high mortality. There are few reports of successfully managed cases and even fewer of long term survival. We report a case of an aortoesophageal fistula resulting from a mycotic pseudoaneurysm of the distal aortic arch in a patient with melioidosis, its surgical management, and outcome.

Severe hepatotoxicity associated with bromfenac sodium

Subacute hepatitis and liver failure occurred in a 40-yr-old woman following a 1-month course of treatment with the nonsteroidal anti-inflammatory drug bromfenac. Serologies for hepatitis A, B, and C were negative, as were antinuclear antibodies and ceruloplasmin. A transjugular liver biopsy demonstrated submassive hepatic necrosis. The clinical course was complicated by encephalopathy, fluid retention, and spontaneous bacterial peritonitis, prompting consideration for liver transplantation. With supportive measures, jaundice and fluid retention resolved over a 3-month period. We conclude that prolonged use of bromfenac was the etiological agent in this case, and that this drug can cause severe hepatotoxicity resulting in liver failure.

Inflammatory bowel disease. 2. Current and future therapeutic options

The exact source of interference with the normal protective immune response in patients with inflammatory bowel disease remains unclear. Infectious causes have been proposed, and the increased incidence among family members indicates genetic predisposition. No matter what the pathogenesis may be, the disease is chronic, recurrent, and destructive in many cases. Conventional therapy with 5-ASAs, corticosteroids, immunomodulating agents, methotrexate, and antibiotics often offers relief. However, adverse effects accompany long-term use of many of these agents, so follow-up is important. Much investigation of alternative methods is under way, and anecdotal as well as published experience suggests benefits in at least some patients. Because of the chronic nature of their condition, patients with inflammatory bowel disease often become quite sophisticated in their understanding of treatment methods. Therefore, they should be told of updates regarding new options for disease control. We recommend that patients be seen periodically by a gastroenterologist who has expertise in inflammatory bowel disease, even when the disease is quiescent. Our experience in observing these patients over time strongly supports use of some of the agents discussed in this article for prophylaxis against flares and chronic inflammation.

Inflammatory bowel disease. 1. Origins, presentation, and course

The exact cause of inflammatory bowel disease remains undiscovered, but its destructive nature is clearly recognized. In this article, the authors summarize what is known about the pathogenesis and epidemiology of ulcerative colitis and Crohn's disease and how to distinguish between the two, both clinically and pathologically. They also describe disorders that may mimic inflammatory bowel disease. In part 2 of this article, beginning on page 86, the authors discuss some of the therapeutic options that are the commonly used as well as some that are investigational but show promise for patients with this chronic and relapsing disease.

Renal failure associated with hepatitis C virus infection. Improvement in renal function after treatment with interferon-alpha

Hepatitis C virus infection can result in mixed cryoglobulinemia and associated clinical syndromes including membranoproliferative glomerulonephritis. Reports regarding the efficacy of interferon-alpha (IFN-alpha) in the treatment of patients with membranoproliferative glomerulonephritis and chronic hepatitis C infection have been inconclusive regarding improvement of renal function. We describe two patients with chronic hepatitis secondary to hepatitis C virus complicated by mixed cryoglobulinemia and membranoproliferative glomerulonephritis who developed severe renal failure which resolved after treatment with standard doses of IFN-alpha 2b.

Efficacy of tele-endoscopy in a rural capitated market

PURPOSE

To attempt to quantify the potential for success of tele-endoscopy as a component of the VTMEDNET Plus telemedicine implementation, a multi-part prospective study was undertaken by faculty of the Vermont Initiative for Rural Health Informatics and Telemedicine.

METHOD

The study was comprised of three separate parts, evaluation of image quality, cost analysis, and identification of referring providers needs and attitudes regarding tele-endoscopy.

FINDINGS

The image quality was satisfactory to support remote diagnosis in most cases; there was significant cost savings in a managed care environment; referring providers were generally positive about the attributes of tele-endoscopy.

CONCLUSION

Tele-endoscopy is a viable and cost-effective component within a telemedicine system.

Endoscopic evaluation of iron deficiency anemia. A guide to diagnostic strategy in older patients

Gastrointestinal blood loss is the primary cause of iron deficiency anemia in older adults. Bidirectional endoscopy (combined colonoscopy and esophagogastroduodenoscopy) is highly sensitive and specific in its ability to locate gastro-intestinal lesions resulting in iron deficiency anemia. Although the diagnostic yield of esophagogastroduodenoscopy is higher than that of colonoscopy, the possibility of malignant disease dictates that initial colonoscopy be performed in all but a few cases involving distinct upper gastrointestinal risk factors and symptoms. If neither colonoscopy nor esophagogastroduodenoscopy identifies a source of blood loss, a safe course is to observe the patient and provide supplemental iron. Patients who fail to respond to supplemental iron or who become transfusion-dependent require further evaluation. Small-bowel evaluation has a role in selected patients.

The ability of certain anorexic drugs to suppress food consumption depends on the nutrient composition of the test diet

The effects of five anorexic agents on food consumption were tested in rats offered single, isocaloric, isonitrogenous diets differing in carbohydrate content. Three of the test agents, d-amphetamine, benzphetamine and chlorphentermine, are sympathomimetic and cause CNS stimulation; the others, MK-212 and d-fenfluramine, are thought to facilitate serotonin-mediated neurotransmission. At ED50 doses, the sympathomimetic drugs reduced food consumption whether the test diet was rich (75% dextrin) or poor (25% dextrin) in carbohydrate. In contrast, MK-212 and d-fenfluramine failed to reduce consumption of the 25% dextrin test diet. These observations suggest that anorexic drugs like d-amphetamine and d-fenfluramine do not act via a common "amphetamine receptor," and are compatible with earlier observations, made on rats given diet pairs simultaneously, that enhanced serotoninergic neurotransmission selectively suppresses appetite for carbohydrates.

Tyrosine's vasoactive effect in the dog shock model depends on the animal's starting blood pressure

We examined the effect of tyrosine (10-200 mg/kg given intravenously) or placebo on blood pressure (BP) in dogs made hypotensive (systolic BP = 50 mm Hg) by bleeding one hour previously. Animals which, prior to induction of hypotension, had been normotensive (mean arterial pressures, [MAP] less than or equal to 145 mm Hg) subsequently exhibited a dose-related increase in BP after tyrosine administration. In contrast, dogs which had been hypertensive prior to bleeding exhibited a fall in BP after tyrosine. These observations indicated that prior cardiovascular status may be an important factor influencing responses to exogenous tyrosine, and to endogenous catecholamines produced from the tyrosine.

Prior carbohydrate consumption affects the amount of carbohydrate that rats choose to eat

Consumption of protein-rich, carbohydrate-restricted reducing diets has been associated anecdotally with an increased appetite for carbohydrate. We have tested the effect of such a diet on carbohydrate intake by rats. Rats were given either a calorie-restricted ketogenic diet containing protein and fat or a control diet containing carbohydrate along with the protein and fat. When allowed to choose from a pair of isocaloric, isonitrogenous diets containing 25 or 75% dextrin, ketotic rats ate significantly more carbohydrate and total food than control animals during the first 30 minutes of feeding, apparently requiring more of the carbohydrate to obtain an increase in brain tryptophan similar to controls. Ketotic rats ate a significantly higher proportion of total calories as carbohydrate. Similar results were obtained when sucrose replaced dextrin. When ketotic and control rats chose between two diets differing in proportions of fat or protein, no differences were observed between the groups in total food intake nor in the amounts or proportions of fat or protein eaten. We also compared the effects of a small, isocaloric premeal containing only carbohydrate (1.4 g dextrose) or mixed nutrients on subsequent carbohydrate consumption in otherwise untreated rats allowed to choose from 25 and 75% dextrin diets. Rats eating the carbohydrate premeal subsequently ate as much total food as the mixed-nutrient controls, but significantly less carbohydrate. These observations suggest that carbohydrate intake is influenced by prior nutrient consumption and that prolonged deprivation of carbohydrate can lead to overconsumption of this nutrient when it is reintroduced into the diet.