Effect ofPlasmodium berghei infection on benzoic acid metabolism in mice

Summary The metabolism of benzoic acid was studied inPlasmodium berghei infected mice both in vitro and in vivo. Results of in vitro studies showed a considerable decrease in the ability of the infected liver to detoxify benzoic acid by hippuric acid formation. The in vivo study showed that hippuric acid formation decreases with increasing parasitemia and the emergence of benzoyl-glucoronide. This new pathway stops operating with further increase in parasitemia.     

Hepatic acid hydrolases of albino rats, Mastomys natalensis and albino mice during Plasmodium berghei infection

Changes in liver acid hydrolase activities during the infection of albino rats, Mastomys or mice with Plasmodium berghei are described. B-Glucosidase, B-galactosidase and N-acetyl-B-D-glucosaminidase exhibited widely different responses with acid phosphatase and cathepsin-B the least responsive and are likely to be causally related to immunity of animals.     

Changes in Plasmodium berghei berghei in mice maintained at high temperatures]

The study of the evolution of Plasmodium berghei berghei is made in mice kept in a high temperature (35 degrees C) throughout the experiment. Some of these mouse parasites (less than 30%) show a gigantic atypical morphology. In the parasite growing in animals kept at 35 degrees C, the amount of DNA is higher than DNA rate of the parasites growing in control mice (20-22 degrees C). There is no evidence of any relation between the increase of DNA amount and the morphological modification of these parasites.     

Exotoxin in malaria infection (Plasmodium berghei)

Zusammenfassung Swiss Mäuse, die unbehandelt eine Infektion mitPl. berghei niemals überleben, wurden mit Serum von frisch infizierten Tieren (12. Infektionstag) immunisiert und anschliessend infiziert. Obgleich sich danach in allen Fällen eine schwere Parasitämie entwickelte, heilten 44% derjenigen Tiere nach dem 35. Infektionstag spontan aus, die mit 3 mg Serumprotein/Maus immunisiert waren. Wegen der offensichtlich eingetretenen Immunoblockade überlebten dagegen nach Immunisation mit höheren Proteinmengen (mehr als 30 mg per Maus) keine Tiere.     

Pulmonary edema in mice infected with Plasmodium berghei. Involvement of catecholamines

Mice inoculated with Plasmodium berghei developed a drastic and significant pulmonary edema. Treatment of animals with phenoxybenzamine rendered mice hyporeactive to this physiopathological alteration.     

Hepatic acid hydrolases of albino rats,Mastomys natalensis and albino mice duringPlasmodium berghei infection

Summary Changes in liver acid hydrolase activities during the infection of albino rats,Mastomys or mice withPlasmodium berghei are described. B-Glucosidase, B-galactosidase and N-acetyl-B-D-glucosaminidase exhibited widely different responses with acid phosphatase and cathepsin-B the least responsive and are likely to be causally related to immunity of animals.     

The course ofPlasmodium berghei infection in mice latently infected withToxoplasma gondii

Summary The course of infection with 2 different virulent strains ofPlasmodium berghei was investigated in mice latently infected withToxoplasma gondii. When given the highly virulent ANKA strain ofP. berghei all Toxoplasma-infected mice died but the survival time was prolonged. After infection with the less virulent strain K 173 mice could survive the subsequent infection. In these cases levels of parasitemia depended upon the duration of theT. gondii infection. Mice infected for about 6 weeks withT. gondii showed maximum protection. These studies were conducted in the Institut für Medizinische Parasitologie der Universit?t Bonn (D-5300 Bonn, Federal Republic of Germany).     

Mean cytoplasmic protein concentration of host erythrocytes and the reticulocyte response in Plasmodium berghei infected mice.

The decreasing mean cytoplasmic protein concentration (MPC) of P. berghei host cells is paralled by an increasing parasitemia and percent reticulocyte response. The reticulocyte response parallels the percent parasitemia except during a period of accelerated reticulocytosis noted during the midpoint of the infection at which time the percent reticulocytes increases at a rate more than double the rate of increase of percent parasitemia. Although the reticulocyte population and the host cell population are usually equivalent, the disparity noted suggests the existence of unique characteristics in the reticulocyte response of P. berghei infected mice.     

Hemoglobin concentration changes determined in populations of living host erythrocytes duringPlasmodium berghei infection in mice

Résumé On a mesuré la concentration en hémoglobine de cellules-hôtes vivantes pendant la période d'infection par lePlasmodium berghei de souris. Le premier jour de l'infection on n'a pas constaté de différence significative entre la concentration en hémoglobine des cellules-hôtes et celle des erythrocytes de contrôle. Le 5^e et le 9³ jour le niveau de concentration en hémoglobine des cellules-hôtes a nettement baissé. Le pourcentage de parasitémie était inversément proportionnel à la concentration en hémoglobine de la cellule-hôte, réaction érythropoiétique probable.     

Influence of a hot environmental temperature on the evolution of experimental paludism of the mouse with Plasmodium berghei berghei]

Swiss Mice infected with Plasmodium berghei berghei and maintained in permanence in a hot environmental temperature undergo a chronic infection whereas controls maintained at the laboratory temperature develop always an acute and lethal infection. The hot environmental temperature does not seem to have any action on the pathogenicity of the parasites. Host defences are stimulated.     

Inhibition of methanol metabolism in mice with acetyl salicylic acid

Zusammenfassung Acetylsalicylsäure hemmt die Oxydation von Methanol und Formiat in vivo erheblich, die Katalase nur in vitro, und vermindert den toxischen Effekt der Methanolvergiftung. Der Mechanismus der Methanoloxydationshemmung durch Acetylsalicylsäure könnte eher auf die Verminderung des Peroxyd-Pooles — als die Katalasehemmung — zurückzuführen sein.     

Heterogeneity in filterability of erythrocytes from malaria (Plasmodium berghei)-infected blood

Summary Erythrocytes fromPlasmodium berghei-infected blood show a decrease in deformability with increasing parasitaemia, as measured by filterability through polycarbonate sieves. A major fraction of cells carrying mature parasites and a smaller fraction carrying ring-stage parasites account for the obstruction of filtration, while the remaining infected cells do not contribute to the decrease in filterability. The relation of filterability to metabolic status in infected cells is discussed. Acknowledgment. This investigation received the financial support of the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR 800352) and the Rockefeller Foundation Programme for Great Neglected Diseases.