Diseases caused by protozoan parasites are still an important health problem. These parasites can cause a wide spectrum of diseases, some of which are severe and have high morbidity or mortality if untreated. Since they are still uncontrolled, it is important to find novel drug targets and develop new therapies to decrease their remarkable social and economic impact on human societies. In the p...

Norepinephrine was isolated from the flagellated protozoan, Crithidia jasciculata, and the ciliated protozoan, Tetrahymena pyrijormis, the former having less than onehalf that of the latter. Tetrohymena also synthesizes epinephrine, whereas this substance could not be detected in Crithidia. Isotopically labeled phenylalanine, tyrosine, and dihydroxyphenylalanine were significantly incorporated ...

The removal of Escherichia coli from estuarine water was investigated. The survival of E. coli was dependent on the presence of protozoan predators and not on the presence of lytic bacteria. When indigenous protozoa were removed from estuarine water by filtration, the destruction of coliform populations was negligible. In studies designed to prevent the growth of indigenous bacterial population...

Protozoan and nematode infections of Periplaneta americana in Bulgaria were investigated. Five protozoan and 2 nematode parasites of P. americana were recorded: Endamoeba blattae, Amoeba sp., Lophomonas striata, Nyctotherus ovalis, Balantidium blattarum, Hammerschmidtiella diesingi and Leidynema appendiculatum. Parasite prevalence varied from 1,6% for Amoeba sp. to 32,8% for nematodes. Biometri...

Activation of the immune system against protozoan infections relies particularly on two specific signals provided by cognate interaction of T cells with antigen presenting cells (APCs). The first signal is attributed to binding of the T-cell receptor (TCR) to peptide/MHC complexes on the surface of APCs, whereas the second signal is triggered through binding of several costimulatory molecules o...