Parasites with complex life cycles often stimulate both antibodyand cell-mediated defence mechanisms, whose effectiveness depends on the particular parasite and the stage of infection. Malaria, which is caused by different species of plasmodia, ranks amongst the most common and important parasitic diseases. Infection of humans is initiatedby thebite of an infectedmosquito, resulting in the inje...

A study of thin sections of Paramecium multimicronucleatum, Tetrahymena pyriformis, Tokophrya infusionum, and Amoeba proteus shows that the mitochondria in all these protozoa are similar in certain aspects of their fine structure to that described in metazoan cells. As in higher organisms the mitochondrion is surrounded by a double limiting membrane and contains protrusions directed inward from...

background and objectives: essential oils may improve the utilization of nutrients by ruminal microorganisms. the aim of this study was to assess the effect of different doses of ajowan essential oils (aeo) on growth and fibrolytic activity of anaerobic fungi, and generic distribution of ciliated protozoa ( in vitro ). material and methods: different doses of aeo (0, 150, 300, 450 and 600 ppm) ...

Rumen methanogenesis represents an energy waste for the ruminant and an important source of greenhouse gas; thus, integrated studies are needed to fully understand this process. Eight fauna-free sheep were used to investigate the effect of successive inoculation with holotrich protozoa then with total fauna on rumen methanogenesis. Holotrichs inoculation neither altered rumen fermentation rate ...

Despite the increasing use of rare earth elements (REEs) and oxides (REOs) in various technologies, the information on their ecotoxicological hazard is scarce. Here, the effects of La3+, Ce3+, Pr3+, Nd3+, Gd3+, CeO₂, and eight doped REOs to marine bacteria Vibrio fischeri and freshwater protozoa Tetrahymena thermophila were studied in parallel with REO dopant metals (Co2+, Fe3+, Mn2+, Ni2+, Sr2...

Some media are described which inhibit bacterial growth, but are favorable to protozoan development. A purification technique, which takes advantage of geotropic responses, was devised and used successfully with 7 species of protozoa, including flagellates and ciliates. The method was also used with a Spirillum. For one flagellate which could not be purified in this manner, a procedure involvin...