The parasitism of the itch mite Sarcoptes scabiei (Acariformes: Sarcoptidae)]

The life cycle of the itch mite Sarcoptes scabiei (L.), an intracutaneous parasite of man and animals, has been studied. The paper concerns morphological adaptations, embryonal and postembryonal development, life cycle pattern, scabious passage as a reproductive formation, invasive stages, feeding, reproduction and topical relationships with the host, distribution and survival in the environment.     

Translation of chicken interferon messenger in a cell-free protein synthesis system and in a cell culture

A highly effective cell-free system for protein synthesis was obtained from rabbit reticulocytes and for the first time used for synthesis of biologically active chicken interferon. The optimal conditions for translation of its mRNA were developed. The translation efficacy in the cell-free system was 10-50 times higher than that in the culture of heterologous cells. The higher the purity level of RNA, the higher the translation level. With respect to poly (A+) RNA sedimenting in the sucrose gradient 9S the efficacy reached 2560 units per 1 microgram of RNA. By the content of poly (A), sequences and rate of the sedimentation, mRNA of the chicken interferon was similar to that of the human fibroblast cell interferon. The possible translation of mRNA of the chicken interferon at low concentrations of exogenic potassium ions in the cell-free system is explained by production of interferon in infected cells where the concentration of the intracellular potassium significantly decreases which is indicative of the mRNA interferon similarity with virus templates. It was found that only albino New Zealand rabbits, but also chinchilla may be used for preparation of the cell-free protein synthesizing system. Various exogenic templates in the mRNA-dependent cell-free system prepared from reticulocyte nonfractionated lysate by treatment with micrococcal nuclease stimulated the protein synthesis by 7-15 times.     

Levels of adenylic system components (ATP, ADP, AMP) and cAMP during development of Blastocladiella emersonii

Concentrations of ATP, ADP, AMP, cAMP as well as pyruvate and glucose-6-phosphate were measured in B. lastocladiella emersonii cells developing via RS morphogenetic pathway. They varied significantly in the course of development (1.3-14.8 mumole/g dry weight for the sum of ATP+ADP+AMP; 0.012-5.3 nmole for cAMP; 0.47-1.9 mumole for pyruvate; 0.36-4.78 mumole for glucose-6-phosphate). At the same time the adenylate energy charge remained essentially unchanged (about 0.8) from the middle of exponential growth till the end of the stationary phase. At the late stages of RS-sporangia formation the concentration of all the above compounds decreased by about 10 times, and the adenylate energy charge only by 30%. Positive correlation between the levels of ATP and cAMP in RS cells was demonstrated. The concentration of adenylic nucleotides and cAMP showed the most noticable changes at the end of exponential growth; transition of the point of no return was not accompanied by significant changes in the pools of adenylic system, cAMP or energy charge.     

Reliability of the serological method of examination as a basis for diagnosis of associated respiratory virus infections.

The reliability of the results of serological examination in diagnostics of associated infections was studied on a model of artificially provoked vaccinal infections in humans and in laboratory animals. The effect of administered monopreparations on changes in the level of both homologous and heterologous antibodies was tested. The character of immunological changes following simultaneous administration of two or more respiratory viruses was analysed and the effect of these viruses in diseases of divers etiology was studied. According to the results of experiments on laboratory animals, repeated administration of any of the earlier used respiratory viruses stimulated the accumulation of only homologous antibodies while heterologous antibodies did not increase at all. The results revealed the possibility of simultaneous immunological reorganization of a child's organism in response to the influence of several different antigens from the group of respiratory viruses acting synchronously or in succession. Results of the analysis demonstrated the reliability of the employed serological methods of diagnosis of respiratory virus infections.     

Effects of amiridin and tacrine, drugs effective in Alzheimer's disease, on the activity of monoamine oxidase A and B]

In vitro comparative studies of effects of amiridin (9-amino-2, 3, 5, 6, 7, 8-hexahydro-1H-cyclopentane (b) choline monohydrate hydrochloride) and tacrine physostigmine and piracetam on monoamine oxidase A (MAO-A) and B (MAO-B) activity in the rat brain were carried out. Piracetam (1 x 10(-4)-1 x 10(-3) M) dose-dependently increased MAO-A and MAO-B activity. At all concentrations used (1 x 10(-7)-5 x 10(-4) M) physostigmine had no effect on MAO-A and MAO-B activity. Amiridin was found to inhibit MAO-B activity at 5 x 10(-4) M concentration only. Tacrine inhibited MAO-A activity at 5 x 10(-4) M concentration. The therapeutical effects of amiridin and tacrine in treatment of Alzheimer disease were not related to their action on MAO-A and -B activity.     

Bacterio- and zooplankton in the outfall of a tributary of a flatland water reservoir during a period of abnormal climatic conditions

Three zones were distinguished according to the electrical conductivity of water in a flatland water reservoir: the transitional zone of the tributary, the frontal zone, and the transitional zone of the inlet. According to the presence of the edge effect, the frontal zone of the outfall area is identified as an ecotone. The buffer properties of the ecotone are conductive to the reduced response of the zooplankton to the increase in water temperature during an abnormally warm year.     

Development of Anncaliia algerae (Microsporidia) in Drosophila melanogaster

Representatives of the genus Anncaliia are known as natural parasites of dipteran and coleopteran insects, amphipod crustaceans, but also humans, primarily with immunodeficiency. Anncaliia algerae‐caused fatal myositis is considered as an emergent infectious disease in humans. A. (=Nosema, Brachiola) algerae, the best studied species of the genus, demonstrates the broadest among microsporidia range of natural and experimental hosts, but it has never been propagated in Drosophila. We present ultrastructural analysis of development of A. algerae in visceral muscles and adipocytes of Drosophila melanogaster 2 wk after per oral experimental infection. We observed typical to Anncaliia spp. features of ultrastructure and cell pathology including spore morphology, characteristic extensions of the plasma membrane, and presence of “ridges” and appendages of tubular material at proliferative stages. Anncaliia algerae development in D. melanogaster was particularly similar to one of A. algerae and A.(Brachiola) vesicularum in humans with acute myositis. Given D. melanogaster is currently the most established genetic model, with a fully sequenced genome and easily available transgenic forms and genomic markers, a novel host–parasite system might provide new genetic tools to investigate host–pathogen interactions of A. algerae, as well to test antimicrosporidia drugs.