Xylose and cellobiose fermentation to ethanol by the thermotolerant methylotrophic yeast Hansenula polymorpha

Wild-type strains of the thermotolerant methylotrophic yeast Hansenula polymorpha are able to ferment glucose, cellobiose and xylose to ethanol. H. polymorpha most actively fermented sugars to ethanol at 37 degrees C, whereas the well-known xylose-fermenting yeast Pichia stipitis could not effectively ferment carbon substrates at this temperature. H. polymorpha even could ferment both glucose and xylose up to 45 degrees C. This species appeared to be more ethanol tolerant than P. stipitis but more susceptible than Saccharomyces cerevisiae. A riboflavin-deficient mutant of H. polymorpha increased its ethanol productivity from glucose and xylose under suboptimal supply with riboflavin. Mutants of H. polymorpha defective in alcohol dehydrogenase activity produced lower amounts of ethanol from glucose, whereas levels of ethanol production from xylose were identical for the wild-type strain and the alcohol dehydrogenase-defective mutant.     

Specific features of diphtheria vaccinal process in children with rheumatic diseases

Clinical and immunological examination of 55 children aged 6-15 years with rheumatic diseases, immunized against diphtheria, was carried out. All children were immunized at the stage of clinical and laboratory remission and in some cases while undergoing a prolonged course of cytostatic therapy or therapy with nonsteroid anti-inflammatory remedies. This examination demonstrated that in the overwhelming majority of children with rheumatic diseases the diphtheria vaccinal process took an asymptomatic course and had no influence on the course of the main disease. Specific features, characteristic of the immune status of this group of children, were established. In the course of the vaccinal process the restoration of the initially inhibited characteristics (the production of TNF-alpha and IL-2) to normal values were shown to occur, which was indicative of the fact that the reserve capacities of immunocompetent cells were retained in these patients. This study also revealed that immunization of children with rheumatic diseases with adsorbed DT and D toxoids with reduced antigen content was not excessive antigenic stimulation for such children, as it did not lead to immunopathological shifts, but induced transient phase changes in immunological characteristics, similar to those in healthy children. Protective levels of antibodies to diphtheria were shown to retain for a long time with considerable prolongation of intervals between booster injections. The simultaneous course of immunosuppressive maintenance therapy in the average dosage used for the corresponding age group did not inhibit the production of protective antibodies.     

Left ventricular heart aneurism--a new source of resident cardiac stem cells

In the past few years it has been established that the heart contains a reservoir of stem and progenitor cells that have the ability to differentiate in vitro and in vivo toward vascular and cardiac lineages and that show cardiac regeneration potential in vivo following injection into the infracted myocardium. The aim of the present study was to characterize cardiac stem cells in the tissue of chronic left ventricular aneurism. It was shown that human c-kit positive cells were scattered in fibrous, muscle and adipose parts of aneurism tissue. C-kit positive cells localized mainly in fibrous tissue nearby large vessels, however, c-kit positive cells did not express endothelial, smooth muscle or cardiomyocyte cell markers. Co-localization experiments demonstrated that all c-kit positive cells were of non-hematopoietic origin, since they did not express markers such as CD34 and CD45. Majority of c-kit positive cells expressed MDR1, but showed no proliferation activity (Ki67). It thus appears that aneurism tissue could be an alternative source of autologous cardiac stem cells. However, their regeneration capacity should be further explored.     

Induction by ethanol of 'phenomenon of switching estrogen effect' and its correction]

Drinking of 5% ethanol in combination with estradiol induced genotoxic (G) changes in the rat uterine tissue. The changes could be prevented by N-acetylcysteine or melatonin. The data obtained suggest that ascorbic acid and alpha-tocopherol may be recommended in combination with N-acetylcysteine for repair of estrogen effect switching phenomenon.     

Computational method for predicting protein functional sites with the use of specificity determinants

The currently available body of decoded amino acid sequences of various proteins exceeds manifold the experimental capabilities of their functional annotation. Therefore, in silico annotation using bioinformatics methods becomes increasingly important. Such annotation is actually a prediction; however, this can be an important starting point for further laboratory research. This work describes a new method for predicting functionally important protein sites, SDPsite, on the basis of identification of specificity determinants. The algorithm proposed utilizes a protein family aglinment and a phylogenetic tree to predict the conserved positions and specificity determinants, map them onto the protein structure, and search for clusters of the predicted positions. Comparison of the resulting predictions with experimental data and published predictions of functional sites by other methods demonstrates that the results of SDPsite agree well with experimental data and exceed the results obtained with the majority of previous methods. SDPsite is publicly available at http://bioinf.fbb.msu.ru/SDPsite.     

Cytoarchitectonic and neurochemical properties of spinal cord in teleost fishes

Traditional neuromorphological and NADPH-diaphorase methods were used to study the topography, morphology and neurochemical organization properties of spinal cord in teleosts fishes. The heterogeneous population of NO-producing motoneurons was revealed in the motor column of spinal cords from studied species. Dendrites of primary motoneurons formed rich plexus at the spinal segment periphery. This morphological pattern is determined by translational motion of the fishes in the water (trunk-tail movement), and has no connection with the origin of upper and lower extremities. The NO-producing capacity of spinal motoneurons shows their connection with premotor NO-ergic brain system, including over situated motor centers of reticular formation and descending projections of giant steam neurons (Mauthner and Muller cells). The NO-producing Rohon-Berd neurons were found in the dorso-medial part of spinal cord from studied fishes. These cells with the ascending propriospinal targets form spinal nociceptive system. Thus, the sense Rohon-Berd cells and most motor neurons of studied bony fishes are nitric oxide synthesizing ones. Spinal cord NO-synthesizing territories are situated in concordance with dorso-ventral histochemical gradient. Spinal cord interneurons of these fishes produce nitric oxide selectively. The quantity of NO-synthesizing reticular cells is determined by two main factors: the connection with the specialized neurochemical complexes, where NO is a specific neuromodulator, and individual properties of spinal cord structure directed by conditions of morphoadaptation.