[The strategy of a parasite is to preserve and continue its species; some trends for achieving the goal].

The authors show that the strategy of parasites, which is to preserve and continue its species is accomplished mainly by providing of a trophic substrate. Opisthorichiasis is used as an example to show that the nutriceutic biomass of cholangiocytes may be increased due to gene mutations, induced proliferation of liver stem cells, their differentiation to committed ones and cholangiocellular differon elements; moreover, the proliferative processes of mesenchymal components become active in other organs of a host. During their ontogenesis in the intermediate and final hosts, the parasites work out the mechanisms for prolonging their life span to complete a full development cycle (Margaritifera margaritifera glochidia); however, predominantly the parasite-host symbiosis is attended by the latter's lameness. Predation is one of the types of symbiotic relations.

[Complicated forms of superinvasion opisthorchiasis: pathogenetic aspects].

Superinvasion opisthorchiasis is characterized by host growth retardation and weight reduction, which are due to the cleptoeffect of Opisthorchis felineus; metabolic disturbances, proliferative processes, accelerated collagen biosynthesis and biodegradation in the organs reflect parasite-host interactions as components of the system. The productive reactions of visceral pathology are initiated by the parasite's metabolites located in the liver, lung, heart, and testes.

[Morphogenesis of the structural changes of the internal organs in superinvasive opisthorchiasis].

The study of the model of superinvasive opisthorchiasis (SO) in Syrian hamsters and autopsy material obtained from patients with SO, it was shown that during the early period of pulmonary disease, the lungs underwent changes developing on the basis of delayed-type hypersensitivity reactions. In the chronic phase of SO, exudative and predominant productive reactions were revealed leading to the interstitial lung disease, fibrosing alveolitis. In the heart in SO, eosinophilic cell myocarditis was found with subsequent diffuse cardiosclerosis. In the testes, sclerotic processes with atrophy of glandulocytes (Leydig cells) and sustentocytes (Sertoli cells) were detected. The structural changes in the lungs, heart and testes were induced by parasite metabolites, that are deposited in tissues in the form of granules and conglomerates.

[Mechanisms of early light and dark adaptation]. / Izuchenie mekhanizmov rannei svetovoi i temnovoi adaptatsii.

A possible role of transient and sustained mechanisms of vision in early light and dark adaptation was studied using the adaptive fields with different rates of luminance changes. The curve forms of early light and dark adaptation and time integration at different rates of switching on and off the adaptive field were studied as well as the changes of contrast sensitivity related to rates of background luminance changes. The data obtained confirm participation of transient and sustained mechanisms of vision in early light and dark adaptation. The contribution of each mechanism depends on the rate and direction of the luminance changes.