Up-regulation of inducible nitric oxide synthase in Helicobacter pylori-associated gastritis may represent an increased risk factor to develop gastric carcinoma of the intestinal type.

The enzyme inducible nitric oxide synthase (iNOS) is part of the host innate defense system against bacterial infection. During chronic inflammation, like that seen with a Helicobacter pylori infection, constant nitric oxide production may lead to tissue and DNA damage, thus increasing the patient's risk for developing cancer. Several investigations on iNOS expression in H.

Mechanism of antigen presentation after hypertonic loading of soluble antigens.

Hypertonic loading of proteins into cells has been used to introduce soluble proteins into the major histocompatibility complex class I pathway of antigen presentation followed by cytotoxic T-lymphocyte (CTL) induction. The precise mechanism for this pathway is not completely understood. The antigen is either processed and presented by/on the same cell or by professional antigen-presenting cells (APC) after taking up the antigen from damaged or apoptotic cells.