The swimming behaviour of ciliates is mainly determined by membrane potential and transmembrane fluxes. In a chemical gradient, swimming ciliates may approach or move away from the source. Based on experiments on Paramecium, it is generally assumed that chemical attractants and repellents affect the swimming behaviour of ciliates by specific changes in the membrane potential. We have examined w...

Anilines and their derivatives are widely used industrial chemicals that consequently have a high potential for environmental pollution because of their toxicity. So, it is necessary to make an assessment of their environment risk. Of course, their toxicity can be measured using experimental methods. The toxicity of these chemicals has been investigated extensively using fish of tetrahymena pyr...

A method has been devised to fractionate cells of Tetrahymena pyriformis, yielding pure or highly enriched preparations of cilia, cilia-associated soluble material, pellicles, mitochondria, microsomes, and postmicrosomal supernatant . The method prevents the destructive action of lipolytic enzymes commonly associated with this organism . Analysis of the membrane lipids of these fractions reveal...

An alternative in vitro approach to drug screening has been the use of human cell cultures for antiviral agents and microbial cell cultures for the assessment of the carcinogenic potential of selected compounds. A number of protozoan species have been also used as drug screens for anti-protozoal agents. The ciliated protozoan Tetrahymena pyriformis species has been widely utilised as a dru...

Descriptors suitable for the discrimination of four modes of toxic action (MOA) of 221 phenols with respect to the ciliate Tetrahymena pyriformis were selected by using SOM-dissimilarity measures and other well-known feature selection techniques. The performance of these methods and of ensembles of them to predict MOA classes and the toxicity log[1/IGC50] (mmol/L) for each action mechanism when...

We have examined thin sections and replicas of freeze-fractured cilia of Tetrahymena pyriformis. The ciliary necklace located at the base of all freeze-fractured oral and somatic cilia has been studied in thin sections. Since electron-dense linkers have been found to connect both microtubule doublets and triplets to the ciliary membrane at the level of the necklace, the linkers and the associat...

The macronuclei of synchronously dividing mass cultures of Tetrahymena pyriformis (strain WH(6)) were examined with the electron microscope for changes during two division cycles. Samples were prepared at 30-minute intervals for a period of 8(1/2) hours which included the time required to induce synchrony by five heat shocks (4(1/2) hours). The interphase macronucleus contains peripheral, cresc...