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To increase the utility of the previously constructed physical map of the chromosome of Neisseria gonorrhoeae FA1090, 28 additional genetic markers were localized on the map. Cloned gonococcal genes were used to probe Southern blots of restriction enzyme-digested DNA separated on pulsed-field gels, thus identifying the fragment in each of several digests to which the probe hybridized and the map location of each gene. The addition of the new markers brings the total number of mapped loci for this strain to 68; the locations of all of those markers on the updated map are shown.

To investigate the involvement of tumour necrosis factor (TNF) in human malaria, we studied TNF production in patients infected with Plasmodium falciparum, and in co-cultures of human mononuclear cells and malaria parasites in vitro. In the examined sample, plasma TNF levels of over 39 pg/ml were detected in the plasma of 59% of Gambian children with acute malaria, 17% of convalescents, 9% of children with mild infections other than malaria, and 7% of healthy Gambian adults. Mononuclear cells of acute malaria patients, when stimulated with endotoxin in vitro, secreted twice as much TNF as did those of convalescent individuals, and three times that of healthy adult controls. Erythrocytic cultures of P. falciparum stimulated increased TNF secretion by mononuclear cells from uninfected individuals, and a sharp rise in the rate of secretion occurred shortly after schizont rupture. We suggest that malaria fever is mediated, at least in part, through paroxysmal TNF release associated with schizont rupture.