Dipyridamole-induced interferon production in mouse peritoneal leukocytes

The in vitro explanted mouse peritoneal leukocytes were used for the optimization of the dipyridamole-induced interferon production. After 90-120 min incubation of cells with 30-100 microM dipyridamole, the production of interferon reached 6.4 X 10(4) IU/ml. It was demonstrated that the interferon production phase is preceded by the dipyridamole-dependent increase in cAMP concentration. The possibility of cAMP involvement in the mechanism of interferon production is being discussed.     

Disaccharide Nucleosides And Their Enzymatic And Chemical Incorporation Into Oligonucleotides

Abstract

A high yield synthesis of different O-ribofuranosylnucleosides has been achieved. Kinetics of the acid-catalysed hydrolysis of disaccharide nucleosides has been studied. Chemical and enzymatic incorporation of 2′-O-ribofuranosyl-nucleoside residue into oligonucleotides was investigated.     

Use of polyethyleneimine polymer in cell culture as attachment factor and lipofection enhancer

Background  

Several cell lines and primary cultures benefit from the use of positively charged extracellular matrix proteins or polymers that enhance their ability to attach to culture plates. Polyethyleneimine is a positively charged polymer that has gained recent attention as a transfection reagent. A less known use of this cationic polymer as an attachment factor was explored with several cell lines.     

Interactions between the hepatitis C virus protein NS3 and polymethylene derivatives of nucleic bases

Nonstructural protein 3 (NS3) of hepatitis C virus plays a key role in the functioning of the virus. NS3 displays three enzymatic activities, namely, protease activity associated with the N-terminal domain, coupled nucleoside triphosphotase (NTPase), and helicase activities, localized to the C-terminal domain. In this work, we studied the effects of various polymethylene derivatives of nucleic bases on the NTPase (by the example of ATPase) and helicase activities of NS3. It was demonstrated that some tested compounds inhibited NS3 helicase activity; however, a considerable part of the compounds activated the NTPase activity of NS3 and several other proteins displaying NTPase or selective ATPase activity. Such ATPase activators have not been earlier described, suggesting an unusual activation mechanism. The activation ability of the tested compounds depended on the ratio of substrate (ATP) and activator concentrations, and reached its maximum at a 1000-fold excess of the substrate. A mechanism of ATPase activation was proposed to explain the observed effects.     

Relationship of aerobic and anaerobic parameters with 400 m front crawl swimming performance

The aims of the present study were to investigate the relationship of aerobic and anaerobic parameters with 400 m performance, and establish which variable better explains long distance performance in swimming. Twenty-two swimmers (19.1±1.5 years, height 173.9±10.0 cm, body mass 71.2±10.2 kg; 76.6±5.3% of 400 m world record) underwent a lactate minimum test to determine lactate minimum speed (LMS) (i.e., aerobic capacity index). Moreover, the swimmers performed a 400 m maximal effort to determine mean speed (S400m), peak oxygen uptake (V.O2PEAK) and total anaerobic contribution (C_ANA). The C_ANA was assumed as the sum of alactic and lactic contributions. Physiological parameters of 400 m were determined using the backward extrapolation technique (V.O2PEAK and alactic contributions of C_ANA) and blood lactate concentration analysis (lactic anaerobic contributions of C_ANA). The Pearson correlation test and backward multiple regression analysis were used to verify the possible correlations between the physiological indices (predictor factors) and S400m (independent variable) (p < 0.05). Values are presented as mean ± standard deviation. Significant correlations were observed between S400m (1.4±0.1 m·s^-1) and LMS (1.3±0.1 m·s^-1; r = 0.80), V.O2PEAK (4.5±3.9 L·min^-1; r = 0.72) and C_ANA (4.7±1.5 L·O₂; r= 0.44). The best model constructed using multiple regression analysis demonstrated that LMS and V.O2PEAK explained 85% of the 400 m performance variance. When backward multiple regression analysis was performed, C_ANA lost significance. Thus, the results demonstrated that both aerobic parameters (capacity and power) can be used to predict 400 m swimming performance.     

Pheno2Geno - High-throughput generation of genetic markers and maps from molecular phenotypes for crosses between inbred strains

Background

Genetic markers and maps are instrumental in quantitative trait locus (QTL) mapping in segregating populations. The resolution of QTL localization depends on the number of informative recombinations in the population and how well they are tagged by markers. Larger populations and denser marker maps are better for detecting and locating QTLs. Marker maps that are initially too sparse can be saturated or derived de novo from high-throughput omics data, (e.g. gene expression, protein or metabolite abundance). If these molecular phenotypes are affected by genetic variation due to a major QTL they will show a clear multimodal distribution. Using this information, phenotypes can be converted into genetic markers.

Results

The Pheno2Geno tool uses mixture modeling to select phenotypes and transform them into genetic markers suitable for construction and/or saturation of a genetic map. Pheno2Geno excludes candidate genetic markers that show evidence for multiple possibly epistatically interacting QTL and/or interaction with the environment, in order to provide a set of robust markers for follow-up QTL mapping.We demonstrate the use of Pheno2Geno on gene expression data of 370,000 probes in 148 A. thaliana recombinant inbred lines. Pheno2Geno is able to saturate the existing genetic map, decreasing the average distance between markers from 7.1 cM to 0.89 cM, close to the theoretical limit of 0.68 cM (with 148 individuals we expect a recombination every 100/148=0.68 cM); this pinpointed almost all of the informative recombinations in the population.

Conclusion

The Pheno2Geno package makes use of genome-wide molecular profiling and provides a tool for high-throughput de novo map construction and saturation of existing genetic maps. Processing of the showcase dataset takes less than 30 minutes on an average desktop PC. Pheno2Geno improves QTL mapping results at no additional laboratory cost and with minimum computational effort. Its results are formatted for direct use in R/qtl, the leading R package for QTL studies. Pheno2Geno is freely available on CRAN under “GNU GPL v3”. The Pheno2Geno package as well as the tutorial can also be found at: http://pheno2geno.nl.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-015-0475-6) contains supplementary material, which is available to authorized users.     

Biogenic polyamines spermine and spermidine activate RNA polymerase and inhibit RNA helicase of hepatitis C virus

Influence of the biogenic polyamines spermine, spermidine, and putrescine as well as their derivatives on the replication enzymes of hepatitis C virus (HCV) was investigated. It was found that spermine and spermidine activate HCV RNA-dependent RNA polymerase (NS5B protein). This effect was not caused by the stabilization of the enzyme or by competition with template-primer complex, but rather it was due to achievement of true maximum velocity V _max. Natural polyamines and their derivatives effectively inhibited the helicase reaction catalyzed by another enzyme of HCV replication — helicase/NTPase (NS3 protein). However, these compounds affected neither the NTPase reaction nor its activation by polynucleotides. Activation of the HCV RNA polymerase and inhibition of the viral helicase were shown at physiological concentrations of the polyamines. These data suggest that biogenic polyamines may cause differently directed effects on the replication of the HCV genome in an infected cell.     

The combined application of nucleotide and amino acid sequences of NS3 hepatitis C virus protein,DNA encoding granulocyte macrophage colony-stimulating factor,and inhibitor of regulatory T cells induces effective immune responce against Hepatitis C virus

Hepatitis C is related to the most important socially significant human infectious diseases. However, there is no vaccine for the hepatitis C virus. The nonstructural protein NS3 of the hepatitis C virus (HCV), which is synthesyzed in the infected cells and it displays protease, NTPase, and helicase enzymatic activities, is one of the possible components of the vaccine. The connection between the effectiveness of the T-cell response to NS3 epitopes and the spontaneous resolution of acute hepatitis C has been shown. The purpose of this work was to compare the immune response of mice to the inoculation of the nucleotide and amino acid sequences of HCV NS3 and their combination, as well as to evaluate the adjuvant activity of the DNA encoding of granulocyte macrophage colony-stimulating factor (GM-CSF) and the influence of regulatory T cells on the effectiveness of the immune response. The maximum anti-HCV NS3 antibody level in the serum (up to 1: 640000) induced the recombinant rNS3 protein introduced with aluminum hydroxide. The most intensive cellular immune response was observed after the simultaneous administration of rNS3 and DNAs encoding full-size NS3 and GM-CSF. A high level of lymphocyte proliferation, accumulation of IFN-γ-secreting cells, and IFN-γ/IL-2 release in response to the stimulators (NS3 antigens of different compositions) were observed in this group of mice. It has been established that the in vitro suppression of regulatory T cells leads to a statistically significant increase in the secretion of IFN-γ. Thus, the simultaneous application of rNS3, along with the DNAs encoding full-size NS3 and GM-CSF, is a promising approach to the development of hepatitis C vaccine. The expediency of adding regulatory T-cell inhibitors in the vaccine composition will be clear after special studies.