The effect of RNA interference Down-regulation of RNA editing 3'-terminal uridylyl transferase (TUTase) 1 on mitochondrial de novo protein synthesis and stability of respiratory complexes in Trypanosoma brucei

Inhibition of RNA editing by down-regulation of expression of the mitochondrial RNA editing TUTase 1 by RNA interference had profound effects on kinetoplast biogenesis in Trypanosoma brucei procyclic cells. De novo synthesis of the apocytochrome b and cytochrome oxidase subunit I proteins was no longer detectable after 3 days of RNAi. The effect on protein synthesis correlated with a decline in the levels of the assembled mitochondrial respiratory complexes III and IV, and also cyanide-sensitive oxygen uptake. The steady-state levels of nuclear-encoded subunits of complexes III and IV were also significantly decreased. Because the levels of the corresponding mRNAs were not affected, the observed effect was likely due to an increased turnover of these imported mitochondrial proteins. This induced protein degradation was selective for components of complexes III and IV, because little effect was observed on components of the F(1).F(0)-ATPase complex and on several other mitochondrial proteins.     

An integrated morphological and molecular approach to a new species description in the Trypanosomatidae: the case of Leptomonas podlipaevi n. sp., a parasite of Boisea rubrolineata (Hemiptera: Rhopalidae)

Leptomonas podlipaevi n. sp., a new trypanosomatid species, is described herein based on light microscopic, ultrastructural, and molecular phylogenetic data. The organism is pleomorphic both in host and culture, with two predominant forms-a typical promastigote with a long flagellum and a shorter promastigote with a small or barely extending flagellum. Several spliced leader RNA repeat sequences obtained from the original cultures and the clonal lines representing two types of cells were all nearly identical. These sequences formed a tight cluster in the neighbor-joining tree well separated from other trypanosomatid species. Glyceraldehyde phosphate dehydrogenase gene sequences were determined for L. podlipaevi and 10 previously described trypanosomatid species. Molecular phylogenetic analysis has demonstrated that the new species is most closely related to Leptomonas seymouri and Leptomonas pyrrhocoris. The analysis has also highlighted the polyphyly of the genus Leptomonas.     

Contribution of the Endogenous Opioid System to Regulation of Heart Resistance to the Arrhythmogenic Effect of Short-term Ischemia and Reperfusion

Preliminary selective blockade of µ, δ₁, δ₂, κ₁, and κ₂ opioid receptors proved to have no effect on the incidence of ventricular arrhythmias during a 10-min coronary occlusion and subsequent reperfusion in ket-amine-anesthetized rats. We propose that the endogenous opioid system has no considerable role in regulation of heart resistance to the arrhythmogenic effect of short-term local ischemia and subsequent reperfusion.__________Translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya, No. 4, 2005, pp. 453–459.Original Russian Text Copyright © 2005 by Maslov, Lishmanov, Budankova, Stakheev, Solenkova, Barzakh, Oeltgen, Gross, Chang.     

Assessment of the functional state of the cerebral cortex in rabbits according to electroencephalographic findings using a computer diagnostic system]

Computer estimation of the current functional state of the cerebral cortex in rabbits by the EEG data permitted to distinguish its peculiarities in dark and light adaptation of different duration under the action of nembutal; individual peculiarities of the cerebral cortex activity were revealed in various rabbits. The automatic converter system and that of recording and analysis of multiprocess information (apromin system) and computer diagnostic system (mds) were used in complex for the multistage processing of the multiprocess information. Final results are presented on the plane as points reflecting multidimentional images of the current functional states of the cerebral cortex in animals.     

Effect of ultrasonic waves on the growth intensity of Mycobacterium leprae in liquid nutrient media

Ultrasound-treated M. leprae grow in liquid culture media at a greater rate than untreated ones. Ultrasound-treated M. leprae retain their capacity for intensive growth after their passage in mice.