Helicobacter induced hepatitis and tumorigenesis

..Recently, gut microbes have been implicated in multisystemic diseases including obesity and diabetes. Here, the hypothesis that specific intestinal bacteria promote liver cancer was tested in chemical and viral transgenic mouse models...

..These results indicate that H. hepaticus urease activity plays a crucial role in hepatic disease but is not required for cecal colonization by H. hepaticus...

..5% versus 1.7%, respectively). The data suggest that H. hepaticus, which is present in many research colonies, promotes colon tumorigenesis in the BALB-RagMin mouse and that it has the potential to confound colon tumorigenesis studies...

..The use of AB6F1 and B6AF1 mice, as well as genetically engineered mice, on a C57BL/6 background will allow studies investigating the role of chronic microbial hepatitis and steatohepatitis in the pathogenesis of liver cancer...

..This model introduces a novel mechanism of inflammation-associated carcinogenesis consistent with male-predominant HCC risk...

..pylori-infected mice at 19 months pi. These data support a protective role for TFF2 in part by modulating levels of gastric interferon-gamma in the development of H. pylori-associated premalignancy of the distal stomach...

..All eight strains of H. macacae had 99.5% identical 16S rRNA sequences...

..Although gallbladder inflammation is believed to be common during cholelithogenesis, the role of immunologic factors is unknown...

..These data provide insights into etiopathogenesis of inflammation-associated epithelial invasion and maintenance of epithelial homeostasis...

..Thus, c-Rel plays a critical role in regulating the innate inflammatory response to microflora within the lower bowel, likely through its ability to modulate expression of IL-12/23 family members...

..05) at 13 WPI. These results demonstrate that genes in the HHGI1 contribute to the pathogenicity of H. hepaticus, at least in part via up-regulation of proinflammatory mediators IFN-gamma, TNF-alpha and IL-17a...

..hepaticus-induced hepatitis in young male mice, whereas androgen receptor agonism does not worsen disease. This raises the possibility of targeted hormonal therapy in young male patients with childhood-acquired HBV...

..bilis and closely related Helicobacter spp. play an etiological role in hepatobiliary disease in both animals and humans...

..These results indicate that WT(Hc) can be used to model inflammatory bowel disease in IL-10(-/-) mice and that CDT contributes to the virulence of H. cinaedi...

..pylori infection, particularly in developing countries, may occur where coinfection with lower bowel helicobacters and H. pylori may be common...

..Collectively, these results confirm essential roles for inflammation, increased TNF-alpha expression, and elevated NO production in colon carcinogenesis...

....

....

..flaA_1 mutants which had flagella but displayed reduced motility did not colonize mice, indicating that motility is required for intestinal colonization by H. hepaticus and that the presence of flagella alone is not sufficient...

..We found high cross-reactivity between the immune responses to H. pylori and H. bilis antigens. More-specific H. bilis antigens need to be isolated to develop serologic tests suitable for epidemiological studies...

..These results indicate that a broad range of Helicobacter spp. infect mouse research colonies. The potential impact of these organisms on in vivo experiments continues to be an important issue for mice being used for biomedical research...

....

..hepaticus catalase. Catalases are highly conserved enzymes in bacteria and mammals that may contribute to autoimmune responses in animals infected with catalase-producing pathogens...

..These findings define a novel mouse model of inflammation-driven mammary carcinoma and suggest that epithelial carcinogenesis can be mitigated by anti-inflammatory cells and cytokines known to regulate IBD in humans and mice...

..Mice infected with HhG and HhNET developed less-severe hepatitis than male A/JCr mice infected with Hh3B1...

..IVSs were found in helices 10, 25, and 45, as well as between helices 31' and 27'. Simultaneous insertion of IVSs at three sites was found in H. mesocricetorum...

..using dietary administration of antibiotics was complicated by the presence of toxin-producing C. difficile. An alternate method to develop helicobacter-free gerbils (such as Caesarian rederivation) may be necessary...

..hepaticus in cecum, colon, and jejunum but only transient colonization of H. hepaticus in the ileum of female mice; (iv) H. hepaticus colonization was associated with down-regulation of colonic IL-10 production...

..Similarities with cancer of the breast, prostate, lung, and other sites raise the possibility of broader roles for regulatory lymphocytes in prevention and treatment of epithelial cancers in humans...

..To test this, we prospectively investigated the effects of Helicobacter spp infection in cholesterol gallstone pathogenesis in the highly susceptible C57L/J mouse model...

..A number of novel Helicobacter species have been isolated from both animals and humans. Many of these helicobacters colonize the lower gastrointestinal tract and hepatobiliary tract and are associated with diseases...

..Our findings likely will prove useful in Helicobacter eradication efforts and in studies designed to further elucidate the role of H. hepaticus in disease...

..These findings provide a molecular basis to improve the specificity of IHC and other immunoassays, and hold implications for antibody-based clinical diagnostics and therapeutics...

..The authors discuss the impact of subclinical and clinical disease and offer recommendations for managing helicobacter-free rodent colonies...

..Suppression of innate immune responses by H. hepaticus LPS thus may affect intestinal responses to the resident microbial flora, epithelial homeostasis, and intestinal inflammatory conditions...

....

..These results suggest that the absence of the p50/p105 subunit of NF-kappaB within hemopoietic cells of the innate immune system interferes with the ability of IL-10 to suppress inflammatory gene expression and Hh-induced colitis...

..To the best of the authors' knowledge, this is the first report describing the isolation of enterohepatic Helicobacter species from a baboon...

..trogontum (with or without H. rodentium) induces a rapid-onset, erosive to ulcerative typhlocolitis which impacts the normal anaerobic flora of the colon and increases the risk of sepsis...

..The possibility that dysregulated gut microbial infections in humans may lead to cancer in anatomically distant organs, such as breast, highlights the need for novel immune-based strategies in cancer prevention and treatment...

..All ASF strains were detected in the cecum and colon, but some strains displayed significant variation in colonization levels with host age, gender, and H. hepaticus infection status...

..Whether these two novel helicobacters pose a zoonotic risk, similar to other enteric helicobacters (e.g., H. canadensis, previously isolated from diarrheic and bacteremic humans and from geese in Europe), will require further studies...

..In this H. hepaticus-challenged IL-10-deficient murine colitis model, lactobacilli demonstrated probiotic effects by direct modulation of mucosal inflammatory responses...