The relative in vitro susceptibility of HeLa cells and three protozoan species to a number of fermentation-derived materials was determined. Of the 61 purified agents tested in tube dilution and plate diffusion tests, 35 had displayed antitumor activity in rodents. The test system found to be most sensitive to the antitumor agents was that employing HeLa cells. Among the protozoan species, the ...

The effects of fixation on the cell volume of marine heterotrophic nanoflagellates and planktonic ciliates were investigated. Decreases in cell volume depended on the combination of the protozoan taxa and the particular fixative. For a particular fixative and protozoan species, degree of shrinkage was independent of physiological state. The volume of fixed cells was found to be approximately 20...

Leukotrienes (LTs), formed by the 5-lipoxygenase-(5-LO-) catalyzed oxidation of arachidonic acid, are lipid mediators that have potent proinflammatory activities. Pharmacologic or genetic inhibition of 5-LO biosynthesis in animals is associated with increased mortality and impaired clearance of bacteria, fungi, and parasites. LTs play a role in the control of helminth and protozoan infections b...