Recent developments in nonspecific inflammatory bowel disease (second of two parts)

Gut microbiota analyses of inflammatory bowel diseases from a representative Saudi population

BACKGROUND

Crohn's diseases and ulcerative colitis, both of which are chronic immune-mediated disorders of the gastrointestinal tract are major contributors to the overarching Inflammatory bowel diseases. It has become increasingly evident that the pathological processes of IBDs results from interactions between genetic and environmental factors, which can skew immune responses against normal intestinal flora.

METHODS

The aim of this study is to assess and analyze the taxa diversity and relative abundances in CD and UC in the Saudi population. We utilized a sequencing strategy that targets all variable regions in the 16 S rRNA gene using the Swift Amplicon 16 S rRNA Panel on Illumina NovaSeq 6000.

RESULTS

The composition of stool 16 S rRNA was analyzed from 219 patients with inflammatory bowel disease and from 124 healthy controls. We quantified the abundance of microbial communities to examine any significant differences between subpopulations of samples. At the genus level, two genera in particular, Veillonella and Lachnoclostridium showed significant association with CD versus controls. There were significant differences between subjects with CD versus UC, with the top differential genera spanning Akkermansia, Harryflintia, Maegamonas and Phascolarctobacterium. Furthermore, statistically significant taxa diversity in microbiome composition was observed within the UC and CD groups.

CONCLUSIONS

In conclusion we have shown that there are significant differences in gut microbiota between UC, CD and controls in a Saudi Arabian inflammatory bowel disease cohort. This reinforces the need for further studies in large populations that are ethnically and geographically diverse. In addition, our results show the potential to develop classifiers that may have add additional richness of context to clinical diagnosis of UC and CD with larger inflammatory bowel disease cohorts.

A Study of the Epidemiology, Clinical, and Phenotypic Characteristics of Inflammatory Bowel Disease in the Northen-Central Region of Saudi Arabia

BACKGROUND

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is becoming increasingly prevalent in Saudi Arabia. However, there is limited data on the characteristics and manifestations of IBD in this population. This study aimed to establish a multi-center database of patients with IBD in the Qassim region of Saudi Arabia to better understand the demographics, prevalence, and manifestations of IBD in this population.

METHODS

This retrospective study included patients diagnosed with IBD at three healthcare facilities in the Qassim region of Saudi Arabia. The patient's demographic and clinical characteristics, disease location and behavior, age at diagnosis, medication use, related surgeries, and extraintestinal manifestations were recorded based on the Montreal classification. A total of 257 patients with IBD were included in the study, of which 126 had UC and 131 had CD.

RESULTS

Of the 257 patients with IBD, 134 (52.2%) were male and 123 (47.8%) were female. The mean age of patients with CD and UC were 28.74 (range 15-67) and 38.79 (range 15-75) years, respectively. There was a significant difference between all age groups (p < 0.005), with more patients aged over 40 years being diagnosed with UC. UC was most commonly classified as left-sided UC (E2) (60; 47.6%), while the most common location of CD was the ileocolon (L3) (76; 58%). Non-stricturing and non-penetrating CD was the most common behavior (B1) (70; 53.8%). Approximately one-third of the patients with Crohn's disease developed perianal disease (70; 27.2%), with fistulizing Crohn's being the most prevalent manifestation (40; 30.5%), followed by abscess formation (10; 7.6%) and fissures (9; 6.8%). The most common extraintestinal manifestation was arthropathy (15; 5.8%). Significant p-values were detected for UC and CD (p = 0.036).

CONCLUSIONS

This study provides crucial insights into the demographics, patterns, and manifestations of IBD in Saudi Arabia. The findings highlight the need for improved diagnosis, management, and treatment strategies for IBD in this population. The establishment of a multi-center database will help to facilitate future research and improve patient care in Saudi Arabia.

Community-Acquired Methicillin-Resistant Pyogenic Liver Abscess: A Case Report

Pyogenic liver abscesses are rare with an incidence of 0.5% to 0.8% and are mostly due to hepatobiliary causes (40% to 60%). Most are polymicrobial with less than 10% being caused by Staphylococcus aureus. Of these, few are caused by methicillin-resistant Staphylococcus aureus (MRSA) and fewer still by a community-acquired strain. Here we present a case study of a patient with a community-acquired MRSA liver abscess. The patient presented with fever since 1 month and tender hepatomegaly. Blood tests revealed elevated levels of alkaline phosphatase, C-reactive protein, erythrocyte sedimentation rate, and neutrophilic leukocytosis. Blood cultures were sterile. Ultrasound of the abdomen showed multiple abscesses, from which pus was drained and MRSA isolated. Computed tomography of the abdomen did not show any source of infection, and an amebic serology was negative. The patient was started on vancomycin for 2 weeks, following which he became afebrile and was discharged on oral linezolid for 4 more weeks. Normally a liver abscess is treated empirically with ceftriaxone for pyogenic liver abscess and metronidazole for amebic liver abscess. However, if the patient has risk factors for a Staphylococcal infection, it is imperative that antibiotics covering gram-positive organisms be added while waiting for culture reports.

Oxidative stress due to Mycobacterium avium subspecies paratuberculosis (MAP) infection upregulates selenium-dependent GPx activity

Objective

This study was designed to determine the relationship between Mycobacterium avium subspecies paratuberculosis (MAP) infection and selenium-dependent glutathione peroxidase (GPx) activity, in the blood of humans and cattle infected with MAP.

Design

MAP infection status and GPx activity were determined in sera from 42 cattle, a group of 27 patients with Crohn’s disease and 27 of their healthy biological relatives, and a group of 66 subjects with various diseases other than Crohn’s disease and 34 non-related healthy subjects.

Results

GPx activity was significantly higher overall in the case of MAP infection in both humans and cattle. The mean value for GPx activity was 1.59 ± 0.65 units/ml in MAP positive cattle compared to 0.46907 ± 0.28 units/ml in healthy cattle sera, where a unit was defined as one mmol/minute (P < 0.01). The mean value of the GPx activity in MAP negative humans clinical sera was 0.42367 ± 0.229 units/ml compared to 0.80941 ± 0.521 in MAP positive sera in a study comparing Crohn’s disease patients to their healthy relatives. The mean activity in MAP negative humans was 0.4702 ± 0.1299 compared to 0.6510 ± 00.1665 units/ml in positive samples in a randomized field study of 100 subjects.

Conclusion

This study demonstrated a strong correlation between MAP and the elevation of GPx activity. This was especially evident in Crohn’s patients, which further supports the association of MAP and Crohn’s disease. GPx activity may also be used to predict MAP infection status and to show that Crohn’s disease patients who are infected with MAP have higher tendency to develop oxidative stress than Crohn’s disease patients who are negative for the bacteria.

Histological Spectrum of Large Intestinal Lesions with Clinicopathological Correlation

INTRODUCTION

Large intestine is affected by various types of lesions, both non-neoplastic and neoplastic. Due to vague symptoms, the clinical diagnosis is usually delayed. A battery of laboratory tests including biopsy is essential to arrive at a specific diagnosis for appropriate management.

MATERIALS AND METHODS

This five years study was done during the period of 2005 to 2010 in a tertiary care centre which included 124 biopsies and resected specimens of large intestine and 64 from Anal canal. All tissues were fixed in formalin, stained with H&E and special stains like Periodic Acid Schiff (PAS), Reticulin, Zeihl Neelsen (ZN) along with Immunohistochemistry (IHC) were done as and when required.

RESULTS

Out of the 124 cases of large intestine 38 were non-neoplastic, 77 were neoplastic and 9 were inadequate biopsies. Sixty four cases from Anal canal included 55 non-neoplastic and 9 neoplastic lesions. The non-neoplastic conditions included congenital anomalies, infective and ischaemic lesions while neoplastic included benign and malignant lesions. Most of the cases presented with symptoms like abdominal pain, vomiting and constipation.

CONCLUSION

We observed that neoplastic lesions were more common in large intestine while non-neoplastic lesions were frequently seen in Anal canal. Present study emphasizes the need for early histopathological diagnosis for appropriate treatment.

Potential of the plant Thespesia populnea in the treatment of ulcerative colitis

CONTEXT

Thespesia populnea Sol. ex Correa (Malvaceae), an indigenous tree species in India, is of interest to researchers because traditionally its heartwood is used in the treatment of ulcer and colic pain.

OBJECTIVE

To validate its folk use in the treatment of ulcerative colitis (UC).

MATERIALS AND METHODS

Mice were administered intrarectal DNBS and then treated with different plant extracts (100 and 200 mg/kg), 30 min before and 24 and 48 h after DNBS infusion. Colonic mucosal injury was assessed by macroscopic and histological examination. Furthermore, malondialdehyde (MDA), myeloperoxidase (MPO), protease, and hemoglobin (Hb) contents were measured in tissue and blood samples.

RESULTS

Administration of various extracts ameliorated macroscopic and microscopic scores which were altered due to DNBS treatment in mice. Hb concentration in blood was restored significantly by the aqueous extract to 17.20 ± 0.5, which was reduced to 13.80 ± 0.5 after treatment with DNBS. MDA level was increased to 10.82 nm/mg and 10.25 nm/ml in tissue and blood, respectively, due to DNBS treatment which was reduced to 2.69 nm/mg and 3.59 nm/ml in tissue and blood, respectively, by aqueous extract treatment. Similarly, MPO level was increased to 412 U/mg and 404 U/ml in tissue and blood, respectively, which was significantly reduced to 205 U/mg and 219 U/ml in tissue and blood, respectively, by aqueous extract treatment. Aqueous extract significantly reduced protease activity which was markedly increased in DNBS-treated animals.

DISCUSSION AND CONCLUSION

Aqueous extract of heartwood of T. populnea is effective in the treatment of UC.

Resection of a methicillin-resistant Staphylococcus aureus liver abscess in a patient with Crohn's disease under infliximab treatment: a case report

Introduction

A liver abscess in Crohn’s disease is a rare but important entity that is associated with a poor prognosis and high mortality when treatment is delayed. We report a case of successful liver segmentectomy for a methicillin-resistant Staphylococcus aureus liver abscess in a patient with Crohn’s disease under infliximab treatment.

Case presentation

A 31-year-old Japanese man, who had been treated with infliximab infusions for Crohn’s disease, was referred to our hospital presenting with an abrupt onset of high fever and an elevated white blood cell count and serum C-reactive protein level. Computed tomography revealed a liver abscess occupying segment 8. The limited effect of percutaneous transhepatic abscess drainage and antibiotics led us to perform radical resection of the abscess. The patient recovered quickly after surgery and the postoperative course was uneventful.

Conclusion

The present case suggests that surgical removal of an abscess should be considered for patients under immunosuppression or refractory to conventional treatment.

Childhood onset of Crohn disease: experience from a university teaching hospital in Saudi Arabia

BACKGROUND AND OBJECTIVES

Crohn disease (CD) is an increasingly recognized problem in Saudi Arabia. The aim of this study was to describe the clinical pattern in children and adolescents with CD seen at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia.

DESIGN AND SETTING

Retrospective hospital-based study conducted on data collected for the period between January 2001 and March 2010.

PATIENTS AND METHODS

Data for all children and adolescents diagnosed at KAUH with CD in the period were retrieved and analyzed.

RESULTS

Ninety-six patients were identified. The median age at diagnosis was 11.3 years (range, 0.12-17.6 years). Fifty (52.1%) were males. Sixty-four (66.7%) were Saudis. Nine (9.4%) had a first degree relative with inflammatory bowel disease. The most common presenting symptoms were diarrhea (88.5%), weight loss (84.2%) and anorexia (80.2%). At least one extraintestinal manifestation occurred in 24% of patients. Forty-two percent were underweight and 19% had short stature. The most common distribution was ileocolonic (37.5%), followed by colonic in 31.2%. Twenty-five (26%) patients had perianal disease, 13 (13.5%) had strictures and 15 (15.6%) had penetrating disease. Laboratory investigations revealed anemia in 84.4%, thrombocytosis in 50%, hypoalbuminemia in 64.6%, elevated erythrocyte sedimentation rate (ESR) in 50% and elevated C-reactive protein in 58.3%. Induction of remission was achieved with enteral nutrition in 20% of patients and with corticosteroids in the remaining.

CONCLUSIONS

The clinical pattern of CD in children from the Western Province of Saudi Arabia was found to be similar to reports from the West. Pediatricians should be aware of the varying presentations of CD. Early referral to specialized centers is crucial.

Efficacy and safety of Fufangkushen colon-coated capsule in the treatment of ulcerative colitis compared with mesalazine: a double-blinded and randomized study

ETHNOPHARMACOLOGICAL RELEVANCE

Fufangkushen colon-coated capsule (FCC) was a newly developed herbal drug for treating ulcerative colitis (UC) patients with traditional Chinese medicine (TCM) pattern of damp-heat accumulating in the interior.

OBJECTIVE

To explore the efficacy and safety of FCC in the treatment of active UC compared with Huidi (HD, mesalazine enteric-coated tablets) were evaluated in a double-blinded and randomized clinical trial.

MATERIALS AND METHODS

In the double-blind, double-dummy, multicenter, randomized and controlled study, 320 active UC patients with TCM pattern of damp-heat accumulating in the interior were assigned to two groups: 240 treated with FCC plus HD placebo treatment, 80 with HD plus FCC placebo. The drugs and their corresponding placebos were administrated at advised dosage for 8 weeks. The primary endpoint was a positive clinical response at week 8, and Mayo scoring system was employed for assessment of UC activity.

RESULTS

At the 8th week, 72.50% of patients in FCC group (170 of 234) and 65.00% of patients in HD group (52 of 80) had achieved a clinical response. There was no statistically significance between the 2 groups (P>0.05). The proportions of patients who had a clinical remission was similar in 2 groups (41.50% in FCC group, 41.25% in HD group, P>0.05), mucosal healing rate at week 8 in the two groups were also without significant difference (55.13% in FCC group, 55.00% in HD group, P>0.05). Mayo scores at week 8 showed no statistically difference in the two groups. No significant differences were observed between the safety profiles of the 2 groups (P>0.05). No severe AEs were reported in either group. The latent class analysis indicated that FCC was superior applicable for the left hemicolon involved patients than HD.

CONCLUSIONS

Compared with HD, a mesalamine enteric-coated tablet, FCC is similarly effective and safe in the treatment of active UC with TCM pattern of damp-heat accumulation interior pattern. In addition, FCC indicates superior effect in the treatment of UC with inflamed area of the left hemicolon than HD.

Inflammatory bowel disease in Saudi Arabia: a hospital-based clinical study of 312 patients

BACKGROUND AND OBJECTIVES

The epidemiology, clinical characteristics, and natural course of inflammatory bowel disease (IBD) in Saudi Arabia are still largely unknown. Hence, we decided to conduct a large retrospective, cohort study to determine these features of the disease.

DESIGN AND SETTING

Retrospective study conducted in a tertiary care hospital in Riyadh from January 1970 to December 2008.

PATIENTS AND METHODS

We reviewed all the cases of IBD diagnosed and collected all data pertaining to patients with IBD.

RESULTS

A total of 312 patients with IBD were included for this analysis, including 197 (63%) patients with Crohn disease (CD) and 115 (37%) patients with ulcerative colitis (UC). The mean age (standard deviation) of patients with IBD was 25.5 (10.6) years; 152 (48.7%) were males and 160 females. The referral rate in the past 10 years was 72.1% compared with preceding 20 years, and 56% (n=178) of patients with IBD were from the central region of Saudi Arabia. The patients were followed up for a mean duration of 9.5 years; during their follow-up, 206 patients (66%) required hospital admission and 9 patients (2.9%) with UC developed colon cancer. A total of 6 patients died during the follow-up. Fifty-three percent (n=104) of the patients with CD underwent surgeries as part of their treatment, whereas only 20% (n=23) of the patients with UC underwent colectomy.

CONCLUSIONS

The incidence of IBD has been gradually increasing in Saudi Arabia over the years. Clinical features and morbidity in patients are not different from patients with IBD seen in the West.

Use of Cordia dichotoma bark in the treatment of ulcerative colitis

CONTEXT

The plant Cordia dichotoma Forst. f. (Boraginaceae) is commonly known as "Bhokar" in Marathi. This tree species has been of interest to researchers because traditionally its bark is reported in the treatment of ulcer and colic pain.

OBJECTIVE

The present work was undertaken to validate its folk use in the treatment of ulcerative colitis (UC) by using scientific methods.

MATERIALS AND METHODS

Dried bark powder was extracted with methanol and this crude methanol extract was fractionated using various solvents. These fractions were tested for effectiveness against UC. Macroscopical study and histopathology of the colon, level of myeloperoxidase (MPO) and malondialdehyde (MDA) in colon and blood were studied for the assessment of the activity. Antioxidant activity of these fractions was screened by using various methods.

RESULTS

Animals treated with the methanol fraction of the crude methanol extract showed lower pathological scores and good healing. This fraction reduced MPO and MDA levels significantly in blood and tissue. It showed antioxidant potential [in DPPH (1,1-diphenyl-2-picrylhydrazyl) assay IC₅₀ value is 26.25; trolox equivalent (TE) antioxidant capacity µg/ml TE/g of plant material on dry basis in ABTS (2,2'-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid) and FRAP (ferric reducing antioxidant potential) assay is 2.03 and 2.45, respectively]. The fraction contains a high level of phenolics.

DISCUSSION AND CONCLUSION

The methanol fraction of crude methanol extract of C. dichotoma bark is effective in the treatment of UC.

The effects of increased extracellular deformation, pressure, and integrin phosphorylation on fibroblast migration

Wound healing requires fibroblast migration. Increased pressure slows migration and ulcer healing. Pressure also induces beta1 integrin phosphorylation. We hypothesized that beta1 phosphorylation influences cell adhesion and migration. We compared the effects of increased pressure on the adhesion and motility of GD25 beta1-integrin null fibroblasts transfected with wild-type beta1A-integrin, S785A or TT788/9AA (phosphorylation-deficient), or T788D (constitutively phosphomimetic) mutants. GD25 beta1 null cells adhered less than wild type beta1A cells, suggesting adherence by non-integrin mechanisms. Preventing Ser-785 or Thr 788/789 phosphorylation reduced adhesion, suggesting that phosphorylation regulates adhesiveness. Substituting Asp for Thr788 stimulated adhesion on both substrates. Pressure decreased migration in all lines and on all matrixes, the most in wild type beta1A integrin cells and only slightly in beta1A TT788/9AA cells. In comparison, another physical force, repetitive deformation, increased migration in the beta1A integrin T788D, S785A, and wild type cells on fibronectin, and decreased migration on collagen. Deformation did not affect the migration of GD25 beta1-integrin null or TT788/9AA cells. Extracellular signal-regulated kinase (ERK) blockade neither altered basal migration nor prevented pressure inhibition, while the cellular deformation response on fibronectin was altered. beta1-Integrin phosphorylation regulates cellular adhesion and the deformation effects on motility. The pressure-induced motility response is independently regulated.

Positive Coombs' test associated with ulcerative colitis. A prevalence study

Among 112 patients with ulcerative colitis (UC), a positive Coombs' test was detected in two cases. The immunoglobulins were IgG and no complement could be detected on the red cells. None of the two patients showed laboratory evidence of hemolysis, although reduced red cell survival was suspected in one patient with a 6-year history of UC, previous autoimmune hemolytic anemia and a positive in vitro monocyte-macrophage phagocytosis test. The HLA-antigens in the two patients were different except for the common antigen HLA-A1.

Supraphysiologic extracellular pressure inhibits intestinal epithelial wound healing independently of luminal nutrient flow

BACKGROUND

Luminal pressure may injure the gut mucosa in obstruction, ileus, or inflammatory bowel disease.

METHODS

We formed Roux-en-Y anastomoses in 19 mice, creating proximal and defunctionalized partially obstructed limbs and a distal limb to vary luminal pressure and flow. We induced mucosal ulcers by serosal acetic acid, and assessed proliferation (proliferating cell nuclear antigen) and ERK (immunoblotting). Parallel studies compared Caco-2 enterocyte migration and proliferation after pressure and/or ERK blockade.

RESULTS

At 3 days, anastomoses were probe-patent, proximal and distal limbs contained chyme, and defunctionalized limbs were empty. The proximal and defunctionalized limbs showed increased pressure and slower healing despite increased proliferation, ERK protein, and ERK activation. In vitro, pressure decreased Caco-2 migration across collagen or fibronectin, stimulated proliferation, and activated ERK. However, ERK blockade did not prevent pressure effects.

CONCLUSIONS

Luminal pressure during obstruction or ileus may impair mucosal healing independently of luminal flow despite increased mitosis and ERK activation.

Strictureplasty

Strictureplasty in patients with Crohn's disease is an option in the colorectal surgeon's armamentarium for fibrostenotic obstructive disease. Common types include the Heineke-Mikulicz strictureplasty, Finney strictureplasty, and the side-to-side isoperistaltic strictureplasty. The procedure has potential for significant morbidity; therefore, it should be chosen for the patient carefully. Strictureplasty complements bowel resection in Crohn's disease; it is an excellent procedure to reduce the risk of developing short-bowel syndrome and its associated complications.

Ulcerative colitis in China: retrospective analysis of 3100 hospitalized patients

BACKGROUND AND AIMS

This retrospective study analyzed the clinical characteristics of hospitalized patients with ulcerative colitis (UC) in China.

METHODS

A total of 3100 hospitalized patients with UC admitted to 23 hospitals in China from 1990 to 2003 were retrospectively investigated and their clinical characteristics were analyzed.

RESULTS

A male/female ratio of 1.34/1.00 was found in the 3100 patients, who had an average age of 44 +/- 15.1 years at diagnosis. Of the patients, 2972 (95.9%) had active UC. Active UC was mild in 35.4% of the 2972 patients, moderate in 42.9% and severe in 21.7%. Of the 2726 patients with a description of their lesion extent, 14.8% had proctitis, 26.4% had proctosigmoiditis, 25.0% had left-sided colitis, 6.3% had extensive colitis, 25.8% had pancolitis and 1.7% had regional colitis. The predominant complaints of the patients with UC were bloody diarrhea (48.2%), abdominal pain (67.3%) and mucus stools (58.4%). Among these patients, 13.6% had extraintestinal manifestations and 9.6% had related complications. A differential diagnosis was difficult to make, as there were 19 varieties of the disease; infectious enterocolitis had a misdiagnosis rate of 22.9% before admission. The main medications for UC in China were aminosalicylates (66.8%) and steroids (42.8%). Only 94 (3%) of the patients required colectomy and only 19 (0.6%) died of UC.

CONCLUSIONS

Compared with UC in Western countries, ulcerative colitis in China has some differences in clinical characteristics. Therefore, a further population-based epidemiological study is required to determine the prevalence and incidence rates of UC in China.

Beneficial effects of N-acetylcysteine on acetic acid-induced colitis in rats

Ulcerative colitis is a chronic recurrent inflammatory bowel disease in which oxidative stress has been implicated. The aim of the present study was to evaluate possible protective effects of N-acetylcysteine against acetic acid-induced colitis in a rat model. Rats were administered intrarectal saline (control group) or acetic acid (colitis model group). Rats with acetic acid-induced colitis were treated by intraperitoneal or intrarectal administration of N-acetylcysteine (500 mg/kg) (treated group). Another series of rats were pre-treated by intraperitoneal or intrarectal administration of N-acetylcysteine, then administered intrarectal acetic acid (pre-treated group). The degree of tissue injuries was assessed by macroscopical and histopathological scores of the colonic mucosa. Malondialdehyde, myeloperoxidase, reduced glutathione, superoxide dismutase, and catalase levels were measured in tissue extracts of the dissected colon. Administration of N-acetylcysteine intraperitoneally or intrarectally ameliorated macroscopic score alterations produced by acetic acid in treated groups. In addition, microscopical improvement was observed in all N-acetylcysteine-treated rats compared to untreated animals with colitis. In the colonic tissues of the acetic acid-induced colitis, myeloperoxidase activity and malondialdehyde levels were elevated, while the reduced glutathione levels and superoxide dismutase and catalase activities were decreased. However, intraperitoneal or intrarectal treatment with N-acetylcysteine reversed these parameters, compared to the untreated colitis group. Notably, intrarectal administration of N-acetylcysteine elevated the reduced glutathione levels more markedly compared to the other treatment groups. Superoxide dismutase levels were increased in intraperitoneally or intrarectally N-acetylcysteine-treated groups significantly compared to the control, colitis and pre-treated groups. But there was no significant increase in catalase activity. In conclusion, N-acetylcysteine could be beneficial as a complementary agent in treatment of ulcerative colitis.

Inflammatory bowel disease associated with Yersinia enterocolitica O:3 infection

BACKGROUND: Certain microorganisms may be associated with the development of inflammatory bowel disease (IBD). These pathogens may possess such properties as immunological capability or tissue invasiveness. An association between Yersinia enterocolitica infection and ulcerative colitis (UC) was suggested 30 years ago, and a connection with Crohn's disease (CD) may also exist. The aim of this study was to further elucidate the association between Y. enterocolitica O:3 infection and IBD. METHODS: During the period 1990-1997, antibody response against Y. enterocolitica was estimated in 1588 patients by tube agglutination. Forty-one patients with Y. enterocolitica infection (titer = 320) constituted the study group; 1041 patients without antibody response constituted the control group. The study was completed in 2003, after 6-13 years. RESULTS: At diagnosis of Y. enterocolitica infection, UC of acute onset was demonstrated in three males; another suffered from CD. At follow-up, two additional patients had developed UC and two CD. In the control group, 32 patients were diagnosed as having UC and 10 CD. This difference in IBD prevalence is significant (8/41>42/1041, p=0.00035), as were the differences in prevalence of UC and CD separately (p=0.006; viz. p<0.015). CONCLUSION: The present study supports the concept of the Y. enterocolitica infection as a trigger of chronic IBD.

Mechanism of TNF-{alpha} modulation of Caco-2 intestinal epithelial tight junction barrier: role of myosin light-chain kinase protein expression

TNF-alpha plays a central role in the intestinal inflammation of various inflammatory disorders including Crohn's disease (CD). TNF-alpha-induced increase in intestinal epithelial tight junction (TJ) permeability has been proposed as one of the proinflammatory mechanisms contributing to the intestinal inflammation. The intracellular mechanisms involved in the TNF-alpha-induced increase in intestinal TJ permeability remain unclear. The purpose of this study was to investigate the possibility that the TNF-alpha-induced increase in intestinal epithelial TJ permeability was regulated by myosin light-chain kinase (MLCK) protein expression, using an in vitro intestinal epithelial model system consisting of the filter-grown Caco-2 intestinal epithelial monolayers. TNF-alpha (10 ng/ml) produced a time-dependent increase in Caco-2 MLCK expression. The TNF-alpha increase in MLCK protein expression paralleled the increase in Caco-2 TJ permeability, and the inhibition of the TNF-alpha-induced MLCK expression (by cycloheximide) prevented the increase in Caco-2 TJ permeability, suggesting that MLCK expression may be required for the increase in Caco-2 TJ permeability. The TNF-alpha increase in MLCK protein expression was preceded by an increase in MLCK mRNA expression but not an alteration in MLCK protein degradation. Actinomycin-D prevented the TNF-alpha increase in MLCK mRNA expression and the subsequent increase in MLCK protein expression and Caco-2 TJ permeability, suggesting that the increase in MLCK mRNA transcription led to the increase in MLCK expression. The TNF-alpha increase in MLCK protein expression was also associated with an increase in Caco-2 MLCK activity. The cycloheximide inhibition of MLCK protein expression prevented the TNF-alpha increase in MLCK activity and Caco-2 TJ permeability. Moreover, inhibitors of MLCK, Mg(2+)-myosin ATPase, and metabolic energy prevented the TNF-alpha increase in Caco-2 TJ permeability, suggesting that the increase in MLCK activity was required for the TNF-alpha-induced opening of the Caco-2 TJ barrier. In conclusion, our results indicate for the first time that 1) the TNF-alpha increase in Caco-2 TJ permeability was mediated by an increase in MLCK protein expression, 2) the increase in MLCK protein expression was regulated by an increase in MLCK mRNA transcription, and 3) the increase in Caco-2 TJ permeability required MLCK protein expression-dependent increase in MLCK activity.

Is nutrition an aetiological factor for inflammatory bowel disease?

Inflammatory bowel disease (IBD) is a chronic inflammatory process, the aetiology of which is complex and probably multi-factorial. Nutrition has been proposed to be an important aetiological factor for IBD. The present review critically examines the relationship between components of the diet (such as sugar, fat, fibre, fruit and vegetables, and protein) and IBD, including ulcerative colitis and Crohn's disease. In addition, it investigates the possible role of infant feeding practices in the development of IBD.

Abdominal pain during pregnancy

Numerous medical, surgical, psychiatric, gynecologic, and obstetric disorders can cause abdominal pain during pregnancy. The patient history, physical examination, laboratory data, and radiologic findings usually provide the diagnosis. The pregnant woman has physiologic alterations that affect the clinical presentation, including atypical normative laboratory values. Abdominal ultrasound is generally the recommended radiologic imaging modality; roentgenograms are generally contraindicated during pregnancy because of radiation teratogenicity. Concerns about the fetus limit the pharmacotherapy. Maternal and fetal survival have recently increased in many life-threatening conditions, such as ectopic pregnancy, appendicitis, and eclampsia, because of improved diagnostic technology, better maternal and fetal monitoring, improved laparoscopic technology, and earlier therapy.

Oxidative stress and antioxidant capacity in patients with inflammatory bowel disease

OBJECTIVES

In this study we aimed to determine the levels of Glutathione peroxidase (GSH-Px) and Malondialdehyde (MDA) in patients with inflammatory bowel disease (IBD) to investigate their contribution to tissue injury in inflammatory bowel disease.

DESIGN AND METHODS

Forty-seven GSH-Px patients (35 with ulcerative colitis and 12 with Crohn's disease) and 30 healthy controls were included in the study. Their plasma and MDA levels were compared using nonparametric statistical methods.

RESULTS

Plasma GSH-Px levels of the patients group were significantly higher than the control group (p < 0.001). There was no significant difference between patients and controls in view of plasma levels of MDA.

CONCLUSIONS

High levels of GSH-Px, which is response against oxidative stress, indicates the increase of free radicals in IBD, while normal plasma MDA levels suggest the clearance of free radicals without leading to lipid peroxidation. Our result reveals that there is an existing antioxidant capacity despite oxidative stress in patients with IBD.

Changes in the bacterial flora of the neoterminal ileum after ileocolonic resection for Crohn's disease

OBJECTIVE

Bacterial agents have been implicated in the early recurrence of Crohn's disease after ileocolectomy. The aim of our study was to identify and quantify bacteria associated with the ileal mucosa in patients and controls and to correlate specific bacteria with recurrence.

METHODS

The predominant bacterial microflora of the ileum were enumerated and identified, aerobically and anaerobically, in biopsies obtained at the time of surgery or by endoscopy from 61 patients with Crohn's disease and 10 ileocolectomy controls. The 61 specimens were comprised of 13 ileal biopsies taken from resection specimens, seven taken after ileostomy, and 41 taken after ileocolectomy.

RESULTS

Ileocolectomy induced a significant increase in bacterial counts and variety in the neoterminal ileum in both patients and controls that was not observed in ileostomy biopsies. Comparison between patients and controls revealed greater numbers of Escherichia coli and enterococci in Crohn's disease and of bifidobacteria and ruminococci in controls. Early recurrence was associated with high counts of E. coli and bacteroides and the frequent isolation of fusobacteria.

CONCLUSION

After ileocolectomy, colonization of the neoterminal ileum is increased. Our data suggest that increases in the populations of specific bacteria such as E. coli, enterococci, bacteroides, and fusobacteria may be important in postoperative recurrence of Crohn's disease.

Nutritional factors in inflammatory bowel disease

Dietary antigens may act as important stimuli of the mucosal immune system and have led to the study of nutritional therapy for IBD. Patients with active CD respond to bowel rest, along with total enteral nutrition or TPN. Bowel rest and TPN are as effective as corticosteroids at inducing remission for patients with active CD, although benefits are short-lived. Enteral nutrition is consistently less effective than conventional corticosteroids for treatment of active CD. Use of palatable, liquid polymeric diets in active CD is controversial, but these diets are of equal efficacy when compared with elemental diets. UC has not been treated effectively with either elemental diets or TPN. Fish oil contains n-3-PUFA, which inhibits production of proinflammatory cytokines and has some benefit in the treatment of CD. Topical applications of short-chain fatty acids have benefited diversion colitis and distal UC, whereas probiotics hold promise in the treatment of pouchitis.

Characterization of antibody responses against rectal mucosa-associated bacterial flora in patients with ulcerative colitis

BACKGROUND

Previous reports on faecal microflora have demonstrated that the total number of aerobes and coliforms was increased in patients with ulcerative colitis (UC). Based on the hypothesis that the pathogenesis of UC may be closely associated with the mucosal microflora, we investigated alterations in the mucosa-associated microflora of UC patients.

METHODS AND RESULTS

The bacterial counts for both aerobes and anaerobes increased in UC patients. In particular, we detected the highest bacterial counts of Bacteroides vulgatus and these bacteria were isolated most frequently. In addition, we also investigated the serum antibody responses against the bacteria isolated from the affected mucosa by serum bacterial agglutination tests and immunoblotting. A high agglutination titre against B. vulgatus, Bacteroides fragilis, and Clostridium ramosum was detected in most UC patients, and the percentage of positive immunoreactivity was much higher in UC patients than in healthy controls. From the results of the immunoblotting, a unique antigenic determinant of B. vulgatus (BV43-26), a 26-kDa protein from the outer membrane, was discovered. The serum immunoreactivity (immunoglobulin (Ig) G) against this 26-kDa protein was much higher in UC patients (53.8%) than in the control sera (9.1%). The serum immunoreactivity (IgG) against a 50-kDa protein isolated from the whole cell protein of Escherichia coli (EC48-1) was also higher in UC patients (29.2%) than in normal controls (6.3%).

CONCLUSIONS

These results suggest that B. vulgatus and a specific antibody response directed against it may play an important role in the pathogenesis of UC.

Distal proctocolitis and n-3 polyunsaturated fatty acids (n-3 PUFAs): the mucosal effect in situ

It has been postulated that patients with ulcerative colitis (UC) have altered reactivity of gut-associated lymphoid tissue. In such cases there is intense infiltration of the mucosa with immune competent cells and associated tissue damage. We have shown previously that the dietary supplementation with the n-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) results in significant systemic immune suppression. The aim of this study, therefore, was to evaluate the in situ effect of n-3 PUFAs on distal proctocolitis. Each patient received either fish oil extract (EPA 3.2 g, DHA 2.4 g) (n = 9) or sunflower oil (n = 9) daily in a double blind manner for six months. Monthly assessment included: (1) disease activity using clinical, sigmoidoscopic, and histological scores and (2) immunohistochemical analysis (immunoglobulins, CD profiles) of rectal biopsy specimens (before and after six months supplementation) using monoclonal antibodies and quantitative computer-assisted video image analysis. Prior to receiving supplementation, patients with proctocolitis (n = 18) showed significantly higher numbers of cells expressing CD3 (pan T cells) and HLA-DR and IgM containing cells compared with non-colitic controls (n = 8). Six months supplementation with n-3 PUFAs resulted in significant reduction in the number of cells expressing CD3 and HLA and the percentage of cells containing IgM. There was no significant change in the CD20 nor the percentage of IgG or IgA containing cells in either group of patients with procto-colitis. In patients receiving n-3 PUFA supplementation, there was improvement in the disease activity and histological scores, compared with pretreatment evaluation. This study has demonstrated both evidence of suppression of in situ immune reactivity and concurrent reduction in disease activity in patients with proctocolitis receiving n-3 PUFA supplementation. This may have important implication for therapy in patients with ulcerative colitis.

Inflammatory bowel disease in Saudi Arabia: presentation and initial management

Non-specific Inflammatory Bowel disease (IBD) is infrequently seen in the Arabs of the Arabian Peninsula. This paper documents the presentation and initial management of 101 such Arabs treated for inflammatory bowel disease between 1976 and 1994. Medical records were examined and patients were classified according to the Organisation Mondiale de Gastroenterologie diagnostic scoring system. Sixty-seven patients had mucosal ulcerative colitis, 28 Crohn's disease (CD) and six indeterminate colitis; age range 2-71 years. Three patients had a family history of (IBD). The diagnosis was made by a combination of the patients' history, physical, radiological, endoscopic and histological examination; however, eight patients were not examined endoscopically and one in four patients was not biopsied at presentation. Thirty-nine patients did not receive any treatment prior to referral. One in three patients was first treated as inpatients. Giardia, Amoeba, Salmonella, Shigella or Schistosoma were detected in the stools of 36 patients at presentation. Following appropriate treatment, these infections were eliminated but the patients' symptoms persisted. Six patients who were thought to have gastrointestinal tuberculosis were subsequently diagnosed with CD. Ten patients had extraintestinal manifestations of their IBD and 11 had side effects (osteoporosis, Cushingoid features and growth retardation) from steroid treatment at other hospitals. Diagnosis was often delayed because infectious diarrhoea was common and awareness was low. Patients were referred late and some had developed complications of therapy.

Evaluation of B and T lymphocytes and plasma cells in colonic mucosa from healthy dogs and from dogs with inflammatory bowel disease

The aim of this study was to investigate the subpopulations of lymphocytes in the colonic mucosa of healthy dogs and dogs with inflammatory bowel disease (IBD). Fourteen normal dogs and 13 dogs with IBD were examined. Endoscopic biopsy specimens of colonic mucosa from each dog were stained specifically for pan T lymphocytes (CD3) and pan B lymphocytes (CD79a), and for plasma cells with methyl green pyronin (MGP) stain. Cells were counted by means of a grid and statistical analysis was performed on the data collected. B and T lymphocytes were also counted in the glandular epithelium of normal dogs and dogs with IBD and the normal and abnormal groups compared statistically. Healthy dogs had significantly lower numbers of T cells in the lamina propria and glandular epithelium and significantly lower numbers of B cells in the lamina propria. Significant group differences for plasma cells were not evident. Our results indicate that in IBD a chronic cellular immune reaction is present in the diseased gut involving increased numbers of B and T lymphocytes.

Nutritional issues in inflammatory bowel disease

Malnutrition is a very common problem in patients with chronic inflammatory bowel diseases. This article discusses the incidence, causes, and clinical consequences of malnutrition in these patient groups. The role of nutritional support administered enterally or parenterally either as primary or adjunctive therapy is highlighted, based on past and more recent controlled studies. Additional attention is given to the roles of glutamine, short-chain fatty acids, fish oil, and alternative nutritional therapy.

Distal procto-colitis, natural cytotoxicity, and essential fatty acids

OBJECTIVES

Recently, it has been postulated that patients with ulcerative colitis have altered natural cytotoxicity, in particular natural killer (NK) and lymphokine-activated killer (LAK) cell activities. These cellular mechanisms have been postulated to play an etiological role in the pathogenesis of the disease process. We have shown previously that the essential fatty acids (EFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) specifically inhibit natural cytotoxicity. Our aim was to evaluate the role of omega-3 EFA in the modulation of natural cytotoxicity and disease activity in patients with distal procto-colitis.

METHODS

In this pilot study patients were randomized into two groups. Each patient received either fish oil extract (EPA, 3.2 g, and DHA, 2.4 g) (n = 9) or sunflower oil (placebo) (n = 9) daily in a double-blind manner for 6 months. Monthly assessments of disease activity (clinical and sigmoidoscopic scores) and histological evaluation of mucosal biopsies were carried out. Also, the circulating levels and activities of NK and LAK cells, using flow cytometric analysis (CD16+ CD56+) and in vitro 51 chromium release assays (K562), respectively, were monitored.

RESULTS

After 6 months' supplementation with EFA, there was improvement in the clinical activity compared with pretreatment evaluation. There was significant reduction in the sigmoidoscopic and histological scores in the EFA group compared with the placebo group. Essential fatty acid supplementation for 6 months also induced significant reduction in the circulating numbers of CD16+ and CD56+ cells and the cytotoxic activity of NK cells, compared with the placebo group.

CONCLUSIONS

This pilot study has demonstrated that omega-3 fatty acids can suppress natural cytotoxicity and reduce disease activity in patients with distal procto-colitis. These findings suggest a therapeutic strategy for managing patients with inflammatory bowel disease.

Regulation of neutrophils in ulcerative colitis by colonic factors: a possible mechanism of neutrophil activation and tissue damage

The mucosal injury of active ulcerative colitis (UC) could involve enhanced migration and activation of neutrophils (PMNs). Because, in vitro, PMNs from patients with UC appear normal and are not therefore a likely cause for the enhancements, we hypothesized an abnormal colonic milieu. We previously found that factors in the UC colonic milieu markedly increase production of reactive oxygen species (ROS) by control PMNs. We now hypothesize that these factors also regulate PMN surface integrins, that regulation of UC PMNs is different than that of control PMNs, and that the integrin regulation is consistent with the ROS regulation. Using rectal dialysis, we sampled the colonic milieu in patients with active UC, in patients with inactive UC, and in control subjects. We monitored a key PMN adhesion molecule, CD11b. When control PMNs were tested, active UC rectal dialysate was almost as effective (+115%) as N-formyl-methionyl-leucyl-phenylalanine (+132%) in up-regulating CD11b. When inactive UC PMNs were tested, baseline CD11b was 50% higher than that for control PMNs. In contrast, rectal dialysates failed to up-regulate CD11b of inactive UC PMNs and in fact down-regulated CD11b. Preincubating control PMNs with UC rectal dialysates converted their CD11b response to PMN activators from up-regulation to down-regulation, mimicking inactive UC PMNs. Changes in intracellular calcium levels paralleled these changes in CD11b. Rectal dialysate-induced changes in both CD11b and calcium paralleled our previous findings on rectal dialysate-induced changes in ROS production. Thus the net overall effect of factors in the colonic milieu is a consistent and predictable regulation of PMN function--proinflammatory in UC, anti-inflammatory in control subjects. These factors may be a critical part of the pathophysiology of UC.

Bacterial persistence and expression of disease

A considerable body of experimental and clinical evidence supports the concept that difficult-to-culture and dormant bacteria are involved in latency of infection and that these persistent bacteria may be pathogenic. This review includes details on the diverse forms and functions of individual bacteria and attempts to make this information relevant to the care of patients. A series of experimental studies involving host-bacterium interactions illustrates the probability that most bacteria exposed to a deleterious host environment can assume a form quite different from that of a free-living bacterium. A hypothesis is offered for a kind of reproductive cycle of morphologically aberrant bacteria as a means to relate their diverse tissue forms to each other. Data on the basic biology of persistent bacteria are correlated with expression of disease and particularly the mechanisms of both latency and chronicity that typify certain infections. For example, in certain streptococcal and nocardial infections, it has been clearly established that wall-defective forms can be induced in a suitable host. These organisms can survive and persist in a latent state within the host, and they can cause pathologic responses compatible with disease. A series of cases illustrating idiopathic conditions in which cryptic bacteria have been implicated in the expression of disease is presented. These conditions include nephritis, rheumatic fever, aphthous stomatitis, idiopathic hematuria, Crohn's disease, and mycobacterial infections. By utilizing PCR, previously nonculturable bacilli have been identified in patients with Whipple's disease and bacillary angiomatosis. Koch's postulates may have to be redefined in terms of molecular data when dormant and nonculturable bacteria are implicated as causative agents of mysterious diseases.

Selective expansion of specific T cell receptors in the inflamed colon of Crohn's disease

To identify disease-specific T cell changes that occur in Crohn's disease (CD), the T cell receptor BV repertoires of lamina propria lymphocytes (LPL) isolated from both the inflamed and "disease-inactive" colons of seven CD patients were compared by the quantitative PCR and DNA sequence analysis. It was observed that the BV repertoires of LPL isolated from the disease-active and disease-inactive parts of the colon from the same individual were very different. Furthermore, nearly all of the differences occurred in CD4+ LPL, with very few differences in the CD8+ population of LPL. Although the pattern of BV segments that was increased in disease-active tissue relative to disease-inactive tissue was different for all seven CD patients, there were several BV segments that increased uniformly in the disease-active tissue of all seven individuals. CDR3 length analysis and DNA sequencing of these BV segments revealed that in six of the seven CD patients there was a striking degree of oligoclonality that was absent from disease-inactive tissue of the same individual. These observations suggest that at least some of the inflammation in CD is the result of responses by CD4+ T cells to specific antigens. The isolation of such inflammation-specific CD4+ T cells may make it possible to identify the antigens that are responsible for the inflammatory process in CD and provide a better understanding of its pathogenesis.

The effect of a selective 5-lipoxygenase inhibitor, zileuton, on tissue damage in acute colonic inflammation in rats

Though the mechanism of tissue damage induced by colonic inflammation in ulcerative colitis is unknown, it has been established that the inflammatory mediator and potent neutrophil (PMN) chemotaxin, leukotriene B4(LTB4), is present in elevated amounts in the inflamed mucosa. The unique role of 5-lipoxygenase in the production of leukotrienes has made it a target for inhibition. This study used a rat model of acute colonic inflammation induced by a single IP injection of Mitomycin-C to test the efficacy of a specific and potent 5-lipoxygenase inhibitor zileuton in the treatment of colonic inflammation. We hypothesized that after inducing colitis in rats with mitomycin-C, the administration of oral zileuton would inhibit leukotriene production, thus preventing PMN infiltration and subsequent tissue damage. Zileuton decreased colonic tissue damage as measured by Histological score. However, zileuton did not significantly decrease neutrophil infiltration measured by mucosal PMN or myeloperoxidase (MPO) levels. Although zileuton was successful in significantly decreasing the frequency of severe colitis in our model, the fact that the decrease in PMN count and MPO level was not statistically significant suggests that another mechanism may be involved in its anti-inflammatory effect.

Pectin-supplemented enteral diet reduces the severity of methotrexate induced enterocolitis in rats

BACKGROUND

Administration of methotrexate (MTX) to rats fed an elemental diet results in a high mortality from severe enterocolitis. Previous studies have shown that pectin is an important precursor of substrates for intestinal structure and function and may facilitate intestinal recovery after enterocolitis. The aim of this study is to evaluate the effect of pectin on MTX-induced enterocolitis in rats.

METHODS

Rats received intragastric infusion of either 1% pectin-supplemented or pectin-free elemental diet from the beginning of the study via a gastrostomy. On the 4th day animals received either MTX, 20 mg/kg intraperitoneally, or saline injection and were killed on the 7th day for sampling.

RESULTS

Pectin supplementation significantly decreased body weight loss, organ water content, and intestinal myeloperoxidase levels and increased mucosal protein, DNA, and RNA content in enterocolitis rats. The intestinal permeability was increased by administration of MTX, and pectin supplementation significantly reversed the increased permeability in the distal small bowel and colon. Pectin supplementation also lowered the magnitude of bacterial translocation, decreased plasma endotoxin levels, and restored bowel microecology.

CONCLUSIONS

Pectin significantly decreased MTX-induced intestinal injury and improved bowel integrity.

Colitis and colonic mucosal barrier dysfunction

Trauma, infection, neoplasia, and inflammation can all disrupt the intact intestinal mucosal barrier to intraluminal bacteria and bacterial antigens. This study investigated the relation between colonic inflammation and colonic mucosal barrier function in three experimental models of colitis. There were significantly increased systemic endotoxin concentrations in rats with acetic acid (7.5 (1.7-119.5) pg/ml), ethanol (13.7 (0-111.2) pg/ml), and hapten induced (14.4 (5-31.1) pg/ml) colitis compared with saline controls (3.3 (0-13.7) pg/ml). Data expressed as median (range). There were significant correlations between the systemic endotoxin concentration and both the severity of colitis and of illness in acetic acid induced colitis. A significant increase in colonic permeability to 14C-polyethylene glycol was shown in rats with acetic acid (3.42 (1.36-5.63)%) and hapten induced colitis (2.86 (1.03-8.10)%) compared with saline controls (1.20 (0.67-1.36)%). Data expressed as median (range) of percentage of the intracolonic bolus excreted in urine. There was a significant positive correlation between the severity of colitis and % colonic permeability to 14C-polyethylene glycol. This and other studies provide evidence that mucosal barrier dysfunction is a feature of colitis irrespective of aetiology or species. Such barrier dysfunction may be responsible for the systemic inflammatory response and complications seen in patients with inflammatory bowel disease.

Detection of immunoreactive antigen, with a monoclonal antibody to measles virus, in tissue from a patient with Crohn's disease

Using immunofluorescence (IF), we investigated reactive antigens present in Crohn's disease patients with monoclonal antibodies derived from cells infected with measles virus, but not with the subacute sclerosing panencephalitis virus. During immunoblotting, one monoclonal antibody (mAb 86) reacted with a polypeptide with a molecular weight of 36,000 dalton (M; matrix protein) in measles virus-infected cells. This monoclonal antibody displayed a positive reaction only with tissues from patients with Crohn's disease by the IF test. It did not react with samples from patients with other chronic inflammatory bowel diseases, such as ulcerative colitis. Other monoclonal antibodies to the measles virus protein, and monoclonal antibodies to Herpes simplex virus type 1 did not react with the same tissue samples. The role of measles virus infection and/or a viral antigen (possibly the M protein) as a causative agent in Crohn's disease poses a challenging avenue for further research.

Treatment strategies for scleritis and uveitis associated with inflammatory bowel disease

We treated 19 patients with anterior uveitis, episcleritis, or scleritis associated with inflammatory bowel disease. Adequate control of ocular inflammation was achieved in 16 patients (84%). Ocular inflammation was adequately controlled with corticosteroids alone, without systemic adverse effects, in only three patients, all of whom had anterior uveitis associated with ulcerative colitis. Systemic nonsteroidal anti-inflammatory drugs proved beneficial in six of seven patients, and one additional patient benefited from another anti-inflammatory drug (hydroxychloroquine sulfate). Systemic cytotoxic immunosuppressive therapy was used in the remaining seven patients, six of whom had bilateral disease. Ocular inflammation was controlled in six of these patients. Azathioprine was beneficial for scleritis but was less effective for anterior uveitis, especially in Crohn's disease, thus necessitating the use of another cytotoxic agent. HLA-B27-positive anterior uveitis was more refractory to corticosteroid therapy and was more likely to require systemic cytotoxic immunosuppressive therapy. With the medical and surgical strategies described, vision was improved or maintained in all patients in the study group.

Studies on peroxisomes of colonic mucosa in Crohn's disease

The etiology and pathogenesis of Crohn's disease, a chronic inflammatory bowel pathology, have not been elucidated yet. In particular, the behavior of peroxisomes in inflamed colonic mucosa has not been investigated despite their important role in cellular oxidative metabolism. Using cytochemistry at the ultrastructural level, we have observed these catalase-positive organelles. In addition, biochemical analyses have revealed the specific activities of catalase and cyanide-insensitive acyl-CoA oxidase. Mucosal biopsy specimens from inflamed and noninflamed areas of Crohn's patients were compared to control biopsies. We found that Crohn's disease was marked by an important diminution in the peroxisomal frequency per cell unit area. If catalase activity was not affected by this pathology, cyanide-insensitive acyl-CoA oxidase, an enzyme of the peroxisomal beta-oxidation system, was found diminished in inflamed and in noninflamed areas. In conclusion, our results showed that Crohn's disease is accompanied by peroxisomal modifications but the number and the enzyme activities of colonic peroxisomes are less deeply altered in Crohn's disease than during neoplasia. This fact suggests that a relation may exist between the degree of peroxisomal deficiency and the clinical severity of colonic disease.

Immunological studies on Crohn's disease. X. Conclusion: a new tentative hypothesis

Although much progress has been made in understanding the pathogenesis of Crohn's disease, the precise etiology of Crohn's disease still remains unknown. In our serial studies on Crohn's disease, we found a decrease in NK and ADCC activities as well as a decrease in the phagocytic activity by monocytes, whereas an increased superoxide production activity by monocytes was evident. On the other hand, the characterization of lymphocyte subpopulations has demonstrated no abnormalities. According to these findings, we would like to propose a new tentative hypothesis for the pathogenesis of Crohn's disease. It has been suggested that impaired killing system activities, such as phagocytic activity as well as NK and ADCC activities, are primarily responsible for the promotion and perpetuation of chronic inflammation and ulceration. When our attention is directed to the most common target substances of these protective mechanisms, viral antigens appear as the most likely causative organism. Therefore, a lot of attention has been focused on viral infection as a causative factor. Furthermore, based on this hypothesis, strategies for effective treatment of this disease are also discussed.