Colonization of gerbils with Helicobacter pylori O-chain-deficient mutant SS1 HP0826::Kan results in gastritis and is associated with de novo synthesis of extended homopolymers.

The O-chain polysaccharide of Helicobacter pylori is important for colonization and generation of chronic gastritis in mice. There are marked host differences in the development of H. pylori-induced gastric pathology in mice and gerbils.

Effects of EGFR Inhibitor on Helicobacter pylori Induced Gastric Epithelial Pathology in Vivo.

Helicobacter pylori transactivates the Epidermal Growth Factor Receptor (EGFR) and predisposes to gastric cancer development in humans and animal models. To examine the importance of EGFR signalling to gastric pathology, this study investigated whether treatment of Mongolian gerbils with a selective EGFR tyrosine kinase inhibitor, EKB-569, altered gastric pathology in chronic H. pylori infection.

Microbial colonization of an in vitro model of a tissue engineered human skin equivalent--a novel approach.

This was a preliminary investigation to define the conditions of colonization of a human skin equivalent (SE) model with cutaneous microorganisms. SEs of 24 mm diameter were constructed with a dermal matrix of fibrin containing fibroblasts and a stratified epidermis. Microbial colonization of the SEs was carried out in a dry environment, comparable to 'in vivo' skin, using a blotting technique to remove inoculation fluid.

The role of inflammation in the pathogenesis of acne and acne scarring.

Evidence now supports a pivotal role for cellular inflammatory events at all stages of acne lesion development, from preclinical initiation to clinical presentation of active lesions through to resolution. The emphasis has moved from acne as a primarily hyperproliferative disorder of the sebaceous follicle to that of an inflammatory skin disorder. However, although the sequence of events leading to lesion formation has become clearer, the triggers for initiation remain speculative.

Gastric mucosal cytokine and epithelial cell responses to Helicobacter pylori infection in Mongolian gerbils.

Experimental infection with Helicobacter pylori in Mongolian gerbils results in chronic gastritis and gastric cancer. To investigate epithelial cell proliferation, apoptosis, and mucosal cytokine responses in gastritis, Mongolian gerbils were infected with the H pylori SS1 strain. At 4 weeks post-infection, gastritis was predominantly within the antrum, but extended to the corpus in approximately 50% of gerbils by 36 weeks.

Long-term infection with Helicobacter felis and inactivation of the tumour suppressor gene p53 cumulatively enhance the gastric mutation frequency in Big Blue transgenic mice.

The aims of this study were to determine whether colonization with Helicobacter felis resulted in the accumulation of mutations within murine gastric tissue and whether the degree of genetic damage was increased by p53 deficiency. Female C57BL/6 mice carrying either the lambda/lacI transgene (Big Blue transgenic mice) or the lambda/lacI transgene and deficient in one allele of the p53 tumour suppressor gene (TSG-p53/Big Blue) were inoculated with H felis. Seven months after inoculation, mutations in the target lacI gene were assessed using the Big Blue transgenic mutagenesis assay system in these animals and in controls.

Inflammatory events are involved in acne lesion initiation.

The earliest subclinical acne "lesion" is a microcomedone, of which hyperproliferation of the follicular epithelium is a characteristic feature. Inflammatory cells have been observed at the periphery of these "lesions". This study investigated whether inflammatory events occur pre or post hyperproliferative changes.

Infection of Mongolian gerbils with Chinese Helicobacter pylori strains.

To date only a few Helicobacter pylori strains have been demonstrated to colonise Mongolian gerbils successfully. The aim of this study was to establish stable colonisation of Chinese strains of H. pylori in gerbils.