FIG. 1.

Infection of SCID mouse livers with E. histolytica induces expression of the gene encoding iNOS. Results of RT-PCR obtained with mRNA from liver samples taken 1 to 7 days following infection with E. histolytica are shown. Expression of iNOS appeared at day 1 (24 h following infection) and persisted until day 5. No induction of iNOS expression was seen in medium-inoculated mice at any time point. The positive control (+CTRL) is mRNA obtained from murine peritoneal macrophages stimulated with lipopolysaccharide and murine IFN-γ; the negative control (−CTRL) is mRNA obtained from unstimulated peritoneal macrophages. The RT-PCR results obtained with murine actin and each sample are also shown.