Churg-Strauss syndrome (allergic granulomatous angiitis) with multiple perforating ulcers of the small intestine, multiple ulcers of the colon, and mononeuritis multiplex

Gastrointestinal Tract Vasculopathy: Clinicopathology and Description of a Possible "New Entity" With Protean Features

Noninfectious gastrointestinal (GI) vasculopathic disorders are rare and are often overlooked in histopathologic examination or when forming differential diagnoses due to their rarity. However, involvement of the GI tract may lead to serious complications, including ischemia and perforation. Since awareness of the types of vasculopathy that may involve the GI tract is central to arriving at a correct diagnosis, we reviewed our institutional experience with GI tract vasculopathy in order to enhance diagnostic accuracy of these rare lesions. We report the clinical and histologic features of 16 cases (excluding 16 cases of immunoglobulin A vasculitis) diagnosed over a 20-year period. Of the 16 patients, 14 presented with symptoms related to the GI vasculopathy (including 2 presenting with a mass on endoscopic examination). The remaining 2 patients presented with incarcerated hernia and invasive adenocarcinoma. The vasculopathy was not associated with systemic disease and appeared limited to the GI tract in 8 patients. Eight had associated systemic disease, but only 6 had a prior diagnosis. The underlying diagnoses in these 6 patients included systemic lupus erythematosus (1), dermatomyositis (2), rheumatoid arthritis (1), eosinophilic granulomatosis with polyangiitis (1), and Crohn disease (1). One patient with granulomatous polyangiitis and 1 patient with systemic lupus erythematosus initially presented with GI symptoms. The 8 cases of isolated GI tract vasculopathy consisted of enterocolic lymphocytic phlebitis (4), idiopathic myointimal hyperplasia of the sigmoid colon (1), idiopathic myointimal hyperplasia of the ileum (1), granulomatous vasculitis (1), and polyarteritis nodosa-like arteritis (1). Isolated GI tract vasculopathy is rare, but appears to be almost as common as that associated with systemic disease. The chief primary vasculopathies are enterocolic lymphocytic colitis and idiopathic myointimal hyperplasia. Although the latter occurs predominantly in the left colon, rare examples occur in the small bowel and likely represent a complex, more protean disorder.

Spontaneous free perforation of the small intestine in adults

Spontaneous free perforation of the small intestine is uncommon, especially if there is no prior history of visceral trauma. However, free, even recurrent, perforation may complicate a defined and established clinical disorder, such as Crohn’s disease. In addition, free perforation may be the initial clinical presentation of an occult intestinal disorder, such as a lymphoma complicating celiac disease, causing diffuse peritonitis and an acute abdomen. Initial diagnosis of the precise cause may be difficult, but now has been aided by computerized tomographic imaging. The site of perforation may be helpful in defining a cause (e.g., ileal perforation in Crohn’s disease, jejunal perforation in celiac disease, complicated by lymphoma or collagenous sprue). Urgent surgical intervention, however, is usually required for precise diagnosis and treatment. During evaluation, an expanding list of other possible causes should be considered, even after surgery, as subsequent management may be affected. Free perforation may not only complicate an established intestinal disorder, but also a new acute process (e.g., caused by different infectious agents) or a longstanding and unrecognized disorder (e.g., congenital, metabolic and vascular causes). Moreover, new endoscopic therapeutic and medical therapies, including use of emerging novel biological agents, have been complicated by intestinal perforation. Recent studies also support the hypothesis that perforation of the small intestine may be genetically-based with different mutations causing altered connective tissue structure, synthesis and repair.

Role of Helicobacter pylori in Gastric Neoplasia

Helicobacter pylori infection is one of the most important factors in gastric carcinogenesis in humans. Epidemiological studies have revealed that H. pylori-infected patients develop significantly more gastric cancers than uninfected individuals. In rodent models, H. pylori inoculation causes strong promoting effects in carcinogen-treated animals, whereas the bacterial infection alone causes only hyperplasic, atrophic, and/or metaplastic lesions. In both human and rodent models, eradication of H. pylori helps inhibit gastric carcinogenesis, especially when there is only mild gastric inflammation and no evidence of severe atrophy or intestinal metaplasia. Chemoprevention studies in humans have been reported and have shown the effectiveness of several medications including a cyclooxygenase-2 inhibitor. Candidate chemicals used in rodent models could hopefully be used in humans in the future.

Helicobacter pylori infection and gastric carcinogenesis in rodent models

Helicobacter pylori infection is an important factor for gastric carcinogenesis in human. In carcinogen-treated Mongolian gerbils, H. pylori infection enhances stomach carcinogenesis, while infection alone induced severe hyperplasia called heterotopic proliferative glands. A high-salt diet or early acquisition of the bacteria exacerbates inflammation and carcinogenesis. Oxygen radical scavengers or anti-inflammatory chemicals as well as eradication of H. pylori are effective to prevent carcinogenesis. H. pylori-associated inflammation induces intestinal metaplasia and intestinalization of stomach cancers independently. It is necessary to control cancer development not only in H. pylori-positive cases but also in H. pylori-negative metaplastic gastritis.

Helicobacter species methods and protocols. Introduction

Helicobacter infection is a chronic persistent condition which is responsible for the majority of cases of gastric and duodenal ulcers, and gastric cancer. The study of the bacteria, the interaction of the bacteria with the host, and the host immune response has greatly benefited from standardization of culture techniques and animal models. The following chapters will describe the clinical aspects of infection and touch on the important techniques for optimal investigation of this infection.

Animal models of Helicobacter-induced disease: methods to successfully infect the mouse

Animal models of microbial diseases in humans are an essential component for determining fulfillment of Koch's postulates and determining how the organism causes disease, host response(s), disease prevention, and treatment. In the case of Helicobacter pylori, establishing an animal model to fulfill Koch's postulates initially proved so challenging that out of frustration a human volunteer undertook an experiment to become infected with H. pylori and to monitor disease progression in order to determine if it did cause gastritis. For the discovery of the organism and his fulfillment of Koch's postulates he and a colleague were awarded the Nobel Prize in Medicine. After H. pylori was established as a gastric pathogen, it took several years before a model was developed in mice, opening the study of the organism and its pathogenicity to the general scientific community. However, while the model is widely utilized, there are a number of difficulties that can arise and need to be overcome. The purpose of this chapter is to raise awareness regarding the problems, and to offer reliable protocols for successfully establishing the H. pylori mouse model.

A patient with Churg-Strauss syndrome who underwent endoscopic sinus surgery under general anesthesia -A case report-

There are many cause of cholinesterase deficiency, including drugs, liver disease, chronic anemia, malignant states, cardiac failure, severe acute infection, surgical shock, severe burn, collagen disease and vasculitis syndromes. Vasculitis syndromes are relatively rare, and among them, Churg-Strauss syndrome (CSS) is even rarer. We report here on a case of a patient with CSS who underwent endoscopic sinus surgery under general anesthesia.

A better method for confirming Helicobacter pylori infection in Mongolian gerbils

BACKGROUND

Our aim was to evaluate the accuracy of the stool antigen test and the optimal time point for detecting Helicobacter pylori infection in a Mongolian gerbil model.

METHODS

We inoculated 8-week-old Mongolian gerbils with H. pylori (Vac A (+)/CagA(+)). The gerbil-infected model was developed as follows: H. pylori was put into broth (about 10(9) CFU/ml), and 50 gerbils were then fed with 1 ml intragastrically twice within a 3-day interval. Another ten gerbils were fed broth only. Twenty-six weeks after the inoculation, the gerbils were killed. The gastric mucosa was sampled for a series of examinations including culture, histology, rapid urease test, and polymerase chain reaction. Stool samples for a stool antigen test, H. pylori-specific stool antigen assay (HpSA), were collected during weeks 4, 6, 8, 12, and 26 after inoculation. Of the 50 gerbils inoculated with H. pylori, the inoculation was successful in 88%. Severe active gastritis, ulceration, and intestinal metaplasia were obvious.

RESULTS

The HpSA test results were sensitivity, 88.6%; specificity, 100%; positive predictive value (PPV), 100%; negative predictive value (NPV), 54.5%, and accuracy, 90%. The HpSA test began to be more sensitive and accurate (P < 0.05) beginning during week 6 after inoculation. We also found that H. pylori could be detected earlier and more easily in the group with high H. pylori density.

CONCLUSIONS

HpSA seems to be suitable for confirming colonization of gerbils with H. pylori. The optimal testing time point is around 6 weeks after inoculation. This test is a good choice for long-term observation of H. pylori infection in Mongolian gerbils.

Animal models of stomach carcinogenesis

Although incidences of stomach cancer have decreased over the past several decades, the disease remains an important public health problem. To identify pathological and molecular biochemical mechanisms, various experimental animal models have been established in rats and mice with chemical carcinogens including N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and N-methyl-N-nitrosourea (MNU). Helicobacter pylori(H. pylori) is one of the most important factors for human stomach disorders, including neoplasia, and the H. pylori-infected and carcinogen-treated Mongolian gerbil (MG) has proven very useful for analyses of underlying processes. The findings with this model support the hypothesis that intestinal metaplasia is important not as a precancerous lesion but rather as a paracancerous condition and that intestinalization of stomach cancer progresses with chronic inflammation. Furthermore, dose-dependent enhancing effects of salt on stomach carcinogenesis could be demonstrated in MGs treated with MNU and H. pylori modifying surface mucous gel layer. H. pylori itself only causes chronic inflammation and acts as a promoter of stomach carcinogenesis in experimental models. Based on the precise pathological diagnosis of stomach lesions such as noncancerous heterotopic proliferative glands (HPG) and adenocarcinomas, a basis for understanding mechanisms of carcinogenesis has been established on which chemoprevention can be modeled.

Ileal ulcers and cytomegalovirus infection in a case of Churg-Strauss syndrome

Churg-Strauss syndrome, or allergic granulomatous angiitis, is an uncommon vasculitic syndrome. We describe a 53-year-old man with Churg-Strauss syndrome and subsequent opportunistic cytomegalovirus enterocolitis. During intensive care, including steroid-pulse therapy, the patient developed rapidly progressive anemia caused by active bleeding from his small intestine, resulting in resection of 20 cm of ileum. Diagnosis of Churg-Strauss syndrome was confirmed both by characteristic clinical features and by histology. Histologic examination also revealed multiple shallow ulcers accompanied by cytomegalovirus infection. Characteristic angiitis was found in the ileum with normal-like mucosa, and it was not necessarily associated with ileal ulcers. This finding suggests that cytomegalovirus infection may be one of the causes or exacerbating factors for ileal ulcers in Churg-Strauss syndrome, although ulcers of the intestine have usually been considered to be caused by ischemia resulting from angiitis.

Direct transmission of H. pylori from challenged to nonchallenged mice in a single cage

To understand whether direct transmission of H. pylori occurs from infected mouse to noninfected mouse, the system using a mouse model we developed previously was tested. Six nude mice were challenged with H. pylori inocula; one group consisted of one challenged nude mouse 1 week after inoculation raised with four nonchallenged nude mice in a single cage. For the single cage, a polycarbonate cage or a mesh-floor cage was used. Then three groups were kept in a polycarbonate cage and the other three groups kept in a mesh-floor cage to avoid H. pylori transmission through stool. After coraising for 1, 2, or 3 weeks, all mice were sacrificed to determine the existence of H. pylori in the stomach, saliva, and stool by culture or PCR and H. pylori-associated gastritis. RAPD fingerprinting patterns using different primers of isolated strains from challenged and nonchallenged mice were compared to understand the origin of transmitted strains. During 3 weeks after coraising of H. pylori challenged and nonchallenged mice, H. pylori was detected in the stomachs in 3 of 12 nonchallenged mice in the polycarbonate cage and in 2 of 12 nonchallenged mice in the cage with a steel mesh floor. H. pylori was detected from saliva or stool in two nonchallenged, infected mice in the polycarbonate cage. Moreover, RAPD fingerprinting using different primers of the total five strains isolated from five nonchallenged, infected mice in both cages showed the same pattern and concordance with that of the challenged strain and the strains isolated from challenged mice. It is demonstrated that intimate interaction is the cause of H. pylori transmission via saliva and stool.

Role of Helicobacter pylori in gastric carcinogenesis: the origin of gastric cancers and heterotopic proliferative glands in Mongolian gerbils

Helicobacter pylori infection is well accepted to be a very important factor for the development of gastric carcinogenesis in the human stomach. In Mongolian gerbils treated with chemical carcinogens, H. pylori infection enhances glandular stomach carcinogenesis, and eradication of infection and results in curtailment of enhancing effects, particularly at early stages of associated inflammation. A high-salt diet exacerbates the effects of H. pylori infection on gastric carcinogenesis, and these two factors act synergistically to promote the development of gastric cancers in this animal model. However, the bacterium exerts the greater effects. Early acquisition significantly increases gastric chemical carcinogenesis in Mongolian gerbils, as compared to later infection. While heterotopic proliferative glands, hyperplastic and dilated glands localized beneath the muscularis mucosae, frequently develop with H. pylori infection alone in this animal model, they obviously regress on eradication, suggesting a relation to severe gastritis, rather than a malignant character. Furthermore, endocrine cells, positive for chromogranin A, are observed in the heterotopic proliferative glands, in contrast to cancerous lesions which lack endocrine elements. In conclusion, H. pylori is not an initiator, but rather a strong promoter of gastric carcinogenesis, whose eradication, together with reduction in salt intake, might effectively prevent gastric cancer development.

Multiple ulcers with perforation of the small intestine in buerger's disease: a case report

We present the case of a young man with Buerger's disease that involved the gastrointestinal tract. The patient experienced sudden onset of abdominal pain during the period of treatment for peripheral manifestations. Radiographic workup revealed free air in the abdomen. A laparotomy was performed, and the resected specimen revealed regularly distanced and multiple ulcers in proximity of the perforation, which was accompanied by occluded intramural arteries of the small intestine. Although visceral localization of Buerger's disease is unusual, several cases have been previously reported. Nevertheless, the manifestation of regularly distanced skip intestinal ulcers in Buerger's disease is apparently unique. In addition, detailed pathological findings delineated this rare condition.

Profiling and identification of eubacteria in the stomach of Mongolian gerbils with and without Helicobacter pylori infection

BACKGROUND

Mongolian gerbils are frequently used to study Helicobacter pylori-induced gastritis and its consequences. The presence of an indigenous bacterial flora with suppressive effect on H. pylori may cause difficulties with establishing this experimental model.

AIM

The aim of the present study was to determine bacterial profiles in the stomach of Mongolian gerbils with and without (controls) H. pylori infection.

METHODS

Gastric tissue from H. pylori ATCC 43504 and CCUG 17874 infected and control animals were subjected to microbial culturing and histology. In addition, gastric mucosal samples from H. pylori ATCC 43504 infected and control animals were analyzed for bacterial profiling by temporal temperature gradient gel electrophoresis (TTGE), cloning and pyrosequencing of 16S rDNA variable V3 region derived PCR amplicons.

RESULTS

Oral administration of H. pylori ATCC 43504, but not CCUG 17874, induced colonization and gastric inflammation in the stomach of Mongolian gerbils. Temporal temperature gradient gel electrophoresis (TTGE) and partial 16S rDNA pyrosequencing revealed the presence of DNA representing a mixed bacterial flora in the stomach of both H. pylori ATCC 43504 infected and control animals. In both cases, lactobacilli appeared to be dominant.

CONCLUSION

These findings suggest that indigenous bacteria, particularly lactobacilli, may have an impact on the colonization and growth of H. pylori strains in the stomach of Mongolian gerbils.

Rapid genetic analysis of Helicobacter pylori gastric mucosal colonization in suckling mice

Previously described animal models for Helicobacter pylori infection have been limited by cumbersome host requirements (e.g., germ-free conditions or unusual species) or are applicable to only special subsets of H. pylori strains (e.g., fresh clinical isolates or animal-adapted derivatives). Here, we report that 5- to 6-day-old outbred CD-1 (ICR) suckling mice support 24-h colonization of all H. pylori strains tested (SS1, 26695 SmR-1, 43504 SmR-1, and G27 SmR-1), including lab-passaged strains that cannot be adapted for colonization of adult animals. Total colony-forming units (cfu) recovered from infection with lab-passaged strains did not differ from those with mouse-adapted SS1. We also tested this model's ability to detect colonization defects in strains carrying mutations in known virulence genes by coinfecting with wild-type H. pylori and measuring differential recovery. This competition assay identified colonization defects in several classes of known attenuated mutants, including those defective in acid resistance (ureA), metabolism (frdA), motility (motB), and chemotaxis (cheY). A mutant defective in copA (copper transporting P-type ATPase) is nonattenuated in adult and infant mice. Possibly because of the limited duration of infection, our model did not identify defects in vacuolating cytotoxin (vacA) or gamma-glutamyltranspeptidase (ggt) as attenuating, in contrast to results from other animal models. We also identified a new virulence gene (HP0507) encoding a conserved hypothetical protein, which is important for colonization in our model. The suckling mouse model offers a rapid method to identify colonization defects in any H. pylori strain and may have utility as a new tool for studying immunity to primary infection.

Helicobacter pylori-induced gastritis in experimentally infected conventional piglets

A conventional nonmutant animal that could be experimentally infected with Helicobacter pylori isolates would be a useful animal model for human H. pylori-associated gastritis. Gnotobiotic and barrier-born pigs are susceptible to H. pylori infection, but attempts to infect conventional pigs with this bacterium have been unsuccessful. In the present study, a litter of eight 20-day-old crossbreed piglets were purchased from a commercial farm. Six of them were orally challenged two to five times at different ages, between 29 and 49 days, with doses of H. pylori inoculum containing approximately 10(9) bacterial cells. Two animals served as controls. The inoculation program began 2 days postweaning when the piglets were 29 days of age. Prior to every inoculation, the piglets were fasted and pretreated with cimetidine, and prior to the first and second inoculation each piglet also was pretreated with dexamethasone. The challenged piglets were euthanasized between 36 and 76 days of age. H. pylori colonized all six inoculated piglets. The pathology of the experimentally induced gastritis was examined macroscopically and by light and electron microscopy. H. pylori induced a severe lymphocytic gastritis in the conventional piglets and reproduced the large majority of the pathologic features of the human disease. Therefore, the conventional piglet represents a promising new model for study of the various pathogenic mechanisms involved in the development of lesions of the human H. pylori-associated gastritis.

Histological and immunohistochemical detection of different Helicobacter species in the gastric mucosa of cats

Detailed histopathological evaluation of the gastric mucosa of Helicobacter-infected cats is complicated by the difficulty of recognizing Helicobacter organisms on hematoxylin and eosin (HE)-stained sections and the ability of multiple Helicobacter species to infect cats. In this study, the presence and localization of different species of Helicobacter in the stomachs of cats was investigated using silver staining and immunohistochemistry. Five groups containing 5 cats each were established (group 1: urease negative and Helicobacter free; groups 2, 3, 4, and 5: urease positive and infected with Helicobacter heilmannii, unclassified Helicobacter spp., Helicobacter felis, and Helicobacter pylori, respectively). Gastric samples were evaluated by HE and silver staining and by immunohistochemistry with 3 different anti-Helicobacter primary antibodies. Helicobacter were detected by Steiner stain in all infected cats at the mucosal surface, in the lumen of gastric glands, and in the cytoplasm of parietal cells. In silver-stained sections, H. pylori was easily differentiated from H. felis, H. heilmannii, and unclassified Helicobacter spp., which were larger and more tightly coiled. No organisms were seen in uninfected cats. Helicobacter antigen paralleled the distribution of organisms observed in Steiner-stained sections for 2 of the 3 primary antibodies tested. The antisera were not able to discriminate between the different Helicobacter species examined. A small amount of Helicobacter antigen was present in the lamina propria of 3 H. pylori-, 3 H. felis-, and 1 H. heilmannii-infected cat. Minimal mononuclear inflammation was present in uninfected cats and in those infected with unclassified Helicobacter spp. and H. heilmannii cats. In H. felis-infected cats, lymphoid follicular hyperplasia with mild pangastric mononuclear inflammation and eosinophilic infiltrates were present. The H. pylori-infected cats had severe lymphoid follicular hyperplasia and mild to moderate mononuclear inflammation accompanied by the presence of neutrophils and eosinophils. These findings indicate that Steiner staining and immunohistochemistry are useful for detecting Helicobacter infections, particularly when different Helicobacter species can be present. Monoclonal antibodies specific for the different Helicobacter species could be important diagnostic aids. There appear to be differences in the severity of gastritis in cats infected with different Helicobacter species.

The gastrointestinal ecosystem: a precarious alliance among epithelium, immunity and microbiota

The gastrointestinal (GI) tract is a complex ecosystem generated by the alliance of GI epithelium, immune cells and resident microbiota. The three components of the GI ecosystem have co-evolved such that each relies on the presence of the other two components to achieve its normal function and activity. Experimental systems such as cell culture, germ-free animal models and intestinal isografts have demonstrated that each member of the GI ecosystem can follow a predetermined developmental pathway, even if isolated from the other components of the ecosystem. However, the presence of all three components is required for full physiological function. Genetic or functional alterations of any one component of this ecosystem can result in a broken alliance and subsequent GI pathology. A more detailed understanding of the interactions among microbiota, GI epithelium and the immune system should provide insight into multiple human disease states.

Establishment of BALB/c mice model infected with Helicobacter pylori

OBJECTIVES

Considering the geographic differences in the prevalence of virulence factors such as CagA or VacA of H. pylori isolated from Korean adults compared with those from western countries, the establishment of a mouse model infected with H. pylori isolated from Korean adults is needed to investigate the pathogenesis and to develop vaccines against H. pylori infection in Korea. The aim of this study was to establish the BALB/c mouse model infected with H. pylori isolated from Korean.

METHODS

Six-week-old BALB/c mice were inoculated intragastrically with 10(9) CFU of H. pylori. Loss of glandular architecture, erosions and infiltration of inflammatory cells within the lamina propria compared with normal gastric mucosa were scrutinized. Evidence for H. pylori infection was assessed by rapid urease test of gastric mucosa and by microscopic examination using the H & E stain and Warthin-Starry silver stain.

RESULTS

Rapid urease test was positive in 55% of all inoculated mice. Definite histologic changes and the evidence of H. pylori colonization were observed in the H. pylori infected group. Significant infiltration of inflammatory cells was observed 6 weeks after the last inoculation and the level of serum IgG against H. pylori was increased from 2 weeks after the last inoculation.

CONCLUSIONS

The H. pylori isolated freshly from Korean adults could colonize the stomach of BALB/c mice and induce pathologic alterations that mimics human gastric diseases. This model would facilitate the investigations for the pathogenetic mechanisms of H. pylori infection.

Host response and vaccine development to Helicobacter pylori infection

Studies in both humans and animals demonstrate that H. pylori is capable of illiciting an innate response that in part is regulated by the genetic makeup of the host. These innate responses includes stimulating immune effector mechanisms at the cellular and biochemical level resulting in the influx of neutrophils into the lamina propria and have even been shown to modify gastric acid secretion. The availability of good animal models of chronic Helicobacter infection has also allowed investigators to begin to examine how the adaptive host immune response prevents and/or exacerbates Helicobacter-induced gastroduodenal disease. The experimental H. felis/mouse model has been utilized by a number of laboratories to investigate mechanisms of host defense against chronic Helicobacter infection. This model and the more recently developed H. pylori rodent model has not only allowed investigators to confirm the feasibility of immunotherapy to prevent and/or cure Helicobacter infection but also to begin to examine how the host immune response prevents and/or exacerbates Helicobacter-induced gastroduodenal disease. Based on these studies a hypothesis is emerging that suggests that protection and/or cure from Helicobacter infection is mediated primarily by an upregulated cellular immune response which may act via an antibody independent mechanism. Paradoxically, following natural infection with H. pylori, a component of the cellular immune response also promotes chronic gastric inflammation without clearance of the organism. The recent development of reliable and reproducible H. pylori/rodent models of disease and the availability of numerous inbred strains, transgenic and knockout animals, will allow investigators to continue to explore the role the host cellular and humoral immune response plays in promoting or preventing this infection.

Experimental infection in cats with a cagA+ human isolate of Helicobacter pylori

BACKGROUND

Helicobacter pylori has been cultured from the inflamed gastric mucosa of naturally and experimentally-infected cats. The lesions in the H. pylori-infected cat stomach mimic many of the features seen in human stomachs infected with H. pylori. This study sought to determine whether H. pylori-negative, specific pathogen-free cats with normal gastric mucosa were susceptible to colonization with a human cagA+ strain of H. pylori, and whether gastritis developed after infections.

METHODS

Four H. pylori-negative cats treated with cimetidine were orally dosed 3 times at 2-day intervals with 3 ml (1.5 x 108 CFU/ml) of H. pylori.

RESULTS

All experimentally-infected cats became persistently colonized as determined by H. pylori isolation from gastric tissue by culture at 12 weeks, and all 4 cats were found positive by PCR during serial gastric biopsies and necropsy at 15 weeks postinoculation. The 2 control cats did not have H. pylori isolated, nor was gastric tissue positive by PCR. The H. pylori isolated from the 4 experimentally-infected cats had RFLP patterns specific for the flaA gene identical to those of the inoculating strain. All 4 H. pylori-infected cats had multifocal gastritis, consisting of lymphoid aggregates plus multiple large lymphoid nodules. In the control cats, one cat had a few focal lymphocytic aggregates in the body submucosa, whereas the second cat had normal gastric mucosa.

CONCLUSION

Human cagA+ H. pylori readily colonized the cat stomach and produced a persistent gastritis. The findings demonstrate the utility of the cat to study H. pylori induced pathogenesis.

Perforation of small intestine caused by Churg-Strauss syndrome

In Churug-Strauss Syndrome (CSS), gastrointestinal tract (GIT) is an uncommon site of involvement. In addition to review of recent literature, we herein report a case of CSS with unusual involvement of GIT. The patient was being treated for idiopathic hypereosinophilic syndrome for 2 years; he later developed acute peritonitis and an emergency laparotomy revealed 3-cm-diameter perforation in the small intestine. In order to establish a correlation between the clinical features and the histopathological findings, we highlight the importance of adequate sampling and examination of mesenteric vessels in the attached mesentry in the resected specimen.

Development of a mouse model of Helicobacter pylori infection that mimics human disease

The human pathogen Helicobacter pylori is associated with gastritis, peptic ulcer disease, and gastric cancer. The pathogenesis of H. pylori infection in vivo was studied by adapting fresh clinical isolates of bacteria to colonize the stomachs of mice. A gastric pathology resembling human disease was observed in infections with cytotoxin-producing strains but not with noncytotoxic strains. Oral immunization with purified H. pylori antigens protected mice from bacterial infection. This mouse model will allow the development of therapeutic agents and vaccines against H. pylori infection in humans.