Titres of antibodies to gut-derived antigens in patients with chronic schistosomiasis mansoni

Serum titres of antibodies against six intestinal, one ubiquitous and one non-intestinal bacteria were determined in patients with severe hepatosplenic schistosomiasis mansoni, with light intestinal schistosomiasis and in normal subjects. No significant difference was observed among the three groups of subjects for levels of antibodies against two nonintestinal bacteria and four of the intestinal bacteria. Patients with hepatosplenic schistosomiasis had titres of antibodies against one strain of Pseudomonas aeruginosa and one strain of Escherichia coli lower than those observed in other groups of subjects. Despite the partial obliteration of the hepatic blood outflow and the elevated portal pressure, hepatic clearance of the portal blood is efficient in chronic human schistosomiasis, and unlike alcoholic liver cirrhosis, avoids excessive stimulation of the immune system by a gut-derived antigens.     

The influence of riboflavin deficiency on Plasmodium berghei infection in rats

Two experiments were done in which rats in various stages of riboflavin deficiency were infected with Plasmodium berghei. Various control groups were included to compare the influence of food restriction on the P. berghei infection with that of riboflavin deficiency, namely, pair-fed (PF), weight-matched (WM) and ad libitum-fed (C-AL) control groups. Riboflavin deficiency depressed maximum parasite counts by comparison with all control groups and the degree of depression was inversely related to the riboflavin status. Survival of animals with P. berghei infection was approximately 10 to 14 days and was not significantly influenced by any of the dietary regimens. Two possible mechanisms by which riboflavin deficiency might influence the growth and multiplication of P. berghei are discussed, namely, a depression of reticulocytosis and an effect on the synthesis of reduced glutathione in the parasite or red blood cell.