Roles of heme oxygenase-1 in the antiproliferative and antiapoptotic effects of nitric oxide on Jurkat T cells.

Nitric oxide (NO) has been shown to exert antiproliferative and antiapoptotic effects on human T cells. Heme oxygenase-1 (HO-1), which degrades heme into biliverdin, free iron (Fe(2+)), and carbon monoxide (CO), has also been known to have antiproliferative and antiapoptotic effects. Recent evidence suggests that HO-1 is an important cellular target of NO; whether HO-1 expression contributes to the antiproliferative and/or antiapoptotic effects mediated by NO remains to be investigated. In the present study, we examined the effects of NO on HO-1 expression and possible roles of HO-1 in T cell proliferation and apoptosis. Using human Jurkat T cells, we found that the NO donor sodium nitroprusside (SNP) induced HO-1 expression and that preincubation with SNP suppressed T cell proliferation induced by concanavalin A and apoptosis triggered by anti-Fas antibody. Suppressions of T cell proliferation and apoptosis comparable with SNP were also observed when the T cells were preincubated with the HO-1 inducer cobalt protoporphyrin. A phosphorothioate-linked HO-1 antisense oligonucleotide blocked HO-1 expression, and subsequently abrogated the antiproliferative and antiapoptotic effects of SNP. Overexpression of the HO-1 gene after transfection into Jurkat T cells resulted in significant decreases in T cell proliferation and apoptosis. The CO donor tricarbonyldichlororuthenium (II) dimer mimicked the antiproliferative effect of SNP, and the Fe(2+) donor FeSO(4) blocked anti-Fas-induced apoptosis. Taken together, our results suggest that NO induces HO-1 expression in T cells and that suppressions of T cell proliferation and apoptosis afforded by NO are associated with an increased expression of HO-1 by NO.

Further Observations On The Prevalence Of Ancylostoma Duodenale And Necator Americanus In The Taegu Area.

In order to determine the prevalence of Necator americanus, 182 fecal samples were collected from school children in the Taegu vicinity. These sample were subsequently cultured by the Harada-Mori technique. Necator americanus was differentiated from Ancylostoma duodenale using the bases of morphological characteristics of filariform larvae. Necator americanus was not found in the vicinity of Taegu.

Treatment Of Hookworm Infection With Furfurol.

Furfurol("Furfudol"), a new anthelmintics, was administered to 7 adults and 21 children (6-12 years old) in total amounts of 15.6 mg(base) for 1 to 3 days. It has proven to be effective against hookworms. The anthelmintic effect against hookworms with a single dose of 15.6 mg of furfurol was similar to that of a single dose of 2.5 gm of bephenium hydroxynaphthoate. However, when a total of 15.6 mg of the base was given to both children and adult, the side reactions were so mild that the drug can be administered for therapeutic regimens in mass treatment. Minor abdominal discomfort was the only common side effect. This is the primary advantage of furfurol as compared with bephenium hydroxynaphthoate. These results have indicated that furfurol is safe in therapeutic dosage and is an effective agent to treat patients infected with hookworms.