Local and systemic complement activity in small intestinal bacterial overgrowth.

It is unknown whether bacteriolysis due to luminal complement activation contributes to local defense mechanisms against small intestinal bacterial overgrowth, particularly with gram-negative bacteria. This study addressed this issue. Thirty adult subjects were investigated with culture of luminal secretions adherent to proximal small intestinal mucosa.

The expression of complement protein 4 and IgG3 in luminal secretions.

Background: Factors regulating proximal small-intestinal luminal concentrations of IgG3, the predominant IgG subclass at this site, are unclear. This study determined whether luminal IgG3 concentrations are related to those of complement protein 4 (C4), an acute-phase reactant predominantly derived from local mucosa.

Methods: Proximal small-intestinal luminal and peripheral blood IgG subclass and C4 concentrations were measured by radial immunodiffusion in 30 adult subjects without predisposition to disturbed mucosal immunity.

Proliferative glomerulonephritis in mice induced by sea snake (Aipysurus laevis) venom.

Aipysurus laevis venom has been shown to have a direct nephrotoxic effect in mice. A single subcutaneous injection (0.075 mg/kg body wt.