Eosinophil-mediated killing of schistosomula of Schistosoma mansoni: Oxidative requirement for enhancement by eosinophil colony stimulating factor (CSF-α) and supernatants with eosinophil cytotoxicity enhancing activity (E-CEA)

Factors which enhance eosinophil-mediated killing of antibody-coated schistosomula of Schistosoma mansoni include semipurified eosinophil colony stimulating factor (CSF-α) and eosinophil cytotoxicity enhancing activity (E-CEA) present in supernatants from cultured mononuclear cells. We have examined the mechanism of enhancement. Both actions require oxygen in order to enhance killing and do not enhance killing under anaerobic conditions (P ? 0.005). E-CEA had no detectable effect upon oxidative metabolism. In contrast to CSF-α which, in our previous studies, increased Superoxide anion productions and quantitative leukocyte iodination, E-CEA had no detectable effect upon oxidative metabolism. In order to test whether active oxygen products might mediate enhancement of killing, the effects of the addition of Superoxide dismutase and catalase were tested. Neither enzyme showed inhibition of CSF-α or E-CEA enhancement of eosinophil-mediated killing. The effects of CSF-α and E-CEA were not additive. These studies suggest that both CSF-α and E-CEA exert enhancement of killing by means of an as yet unidentified oxygen requiring process.     

Synopsis of the genus Mitriostigma (Rubiaceae) with a new monocaulous species from south Cameroon

Mitriostigma monocaule Sonké & Dessein sp. nov., a new Rubiaceae species from south Cameroon is described and illustrated. The novelty is easily separated from the other four Mitriostigma species by its monocaulous growth form, the other species being shrubs, sub-shrubs, or occasionally trees. Another typical character for the species is its supra-axillary inflorescences paired at the nodes. The novelty is related to M. barteri , from which it further differs in the somewhat larger leaves with a more pronounced acumen and a higher number of secondary veins. A first conservation status for the species is given. A synopsis of the genus Mitriostigma with a taxonomic key is also provided.