Anti-inflammatory cytokines of cervical secretions and the blood serum in women with genital infections

In cervical secretions of healthy non-pregnant women of the reproductive age high concentrations of ant-inflammatory cytokines, greatly exceeding those in blood serum, were detected. During pregnancy the level of TNF-alpha in cervical secretions dropped. The inflammation of the uterus neck was accompanied by a drop in the levels of IL-alpha and IL-1beta and a rise in the level of IL-8 in cervical secretions in pregnant and non-pregnant women. Similar changes in the cytokine profile occurred also in the blood serum, but they were less pronounced and could be observed only in non-pregnant women. The threat of the interruption of pregnancy, developing simultaneously with cervicitis, was accompanied not only by changes in the levels of cytokines in cervical secretions, but also by a perceptible increase in the content of IL-1alpha in the blood serum.     

Analogs of nucleotides, modified by a sugar residue and pyrimidine base, in a DNA synthesis reaction, catalyzed by Thermus aquaticus DNA polymerase]

Substrate properties of dNTP analogues in the DNA synthesis reaction catalyzed by Thermus aquaticus DNA polymerase were studied. It was shown that most of dNTP analogues which were known as terminators of DNA synthesis of E. coli DNA polymerase I were able to terminate DNA synthesis catalyzed by Thermus aquaticus DNA polymerase. An interesting feature of Thermus aquaticus DNA polymerase was the ability to utilize 3'-azido-2',3'-dideoxythymidine triphosphate as terminating substrate. Relative efficiency of tested dNTP analogues incorporation into the DNA growing chain was estimated.     

Properties of antigenomic hepatitis delta virus ribozyme cis- and trans- analogs

A series of permuted variants of antigenomic HDV ribozyme and trans-acting variants were constructed. The catalytic activity study of the ribozymes has shown that all the variants were capable of self-cleaving with equally biphasic kinetics. Ribonuclease and Fe(II)-EDTA cleavage have provided evidence that all designed ribozymes fold according to the pseudoknot model and the conformations of the initial and cleaved ribozyme are different. A scheme of HDV ribozyme self-cleavage reaction was suggested. The role of hydrogen bonds in the reaction was evaluated by substitution of ribose in the ribozyme for deoxyribose. It was found that the 2'-OH group of U23 and C27 is critical for the reaction to occur; the 2'-OH group of U32 and U39 is important, while 2'-OH groups of other nucleotides of loop 3, stem 4 and stem 1 are unimportant for the cleavage activity.     

Cytomorphological and cultural characteristics of tylosin-producing strains with different antibiotic activity]

Cytomorphological and cultural characteristics of highly and low active collection strains of Streptomyces fradiae producing tylosin were studied. The strains were grown on agarized and liquid media. It was shown that unlike the low active strain, the highly active one was less sporogenic, the difference being more pronounced when tylosin was added to the agarized medium. When the strains were grown in the fermentation medium there were detected differences between them in the growth type and microcolony structure at the early stages of the fermentation process. During intensive synthesis of tylosin spheric structures were found to form near the hyphal surfaces. The phenomenon was previously observed in cultures producing other antibiotics. In the low active strain the structures were single while in the highly active strain they formed in large numbers.     

Properties of Antigenomic Hepatitis Delta Virus Ribozyme That Consists of Three RNA Oligomer Strands

A three-strand ribozyme, a derivative of antigenomic hepatitis delta virus (HDV) ribozyme, which consists of subfragments of 16 (L), 17 (S), and 33 nucleotides (B), has been constructed. The ternary B-L-S complex formed by the subfragments in stoichiometric ratio was able to catalyze a self-cleavage reaction. Kinetics of this reaction exhibited biphasic behavior and the same parameters as in the case of natural cis-ribozyme. Study of kinetics of reaction initiated by adding various reaction components and the study of binary complex formation between subfragments B and L, B and S, and also ternary B-L-S complex formation revealed that: 1) in the presence of Mg2+, B and S form a stoichiometric complex, L and S do not form complex at all, while B and L form 2 types of complexes, probably B-L and 2B-L; and addition of S subfragment prevented the formation of the latter complex; 2) the reaction initiated by S subfragment proceeds much slower than that initiated by other components pointing to the possibility that in the absence of S L may form a nonproductive complex with B, which is slowly displaced by S followed by productive ternary complex formation. Dissociation constants for binary B-L, B-S and ternary B-L-S complexes have been estimated.     

3′-Fluoro-3′-deoxyribonucleoside 5′-triphosphates: Synthesis and use as terminators of RNA biosynthesis

3′-Fluoro-3′-deoxy-uridine, -cytidine, -adenosine and -guanosine have been synthesized by glycosylation of the corresponding silylated bases with 1-O-acetyl-2,5-di-O-benzoyl-3-fluoro-3-deoxy-D-ribofuranose in the presence of Friedel-Crafts catalysts and were converted to the 5′- triphosphates, NTP(3′-F). It was shown that NTP(3′-F) are terminators of RNA synthesis catalyzed by DNA-dependent RNA polymerase from E. coli and may thus serve as tools for DNA sequencing.     

Total RNA suitable for molecular biology analysis

Development of methods based on determining expression of individual genes resulted in the need for large amounts of high quality RNA preparations. It is widely accepted that in intact rRNA the 28S and 18S band ratio must be 2:1. It is not quite clear what is the main cause of lower rRNA bands intensity ratio. It is difficult to isolate RNA with 2:1 28S/18S ratio from RNase-rich and some tumor tissues. At the same time this requirement may be excessive and RNA preparations with lower 28S/18S rRNA ratio may be quite adequate for most techniques of determining gene expression. As demonstrated in this study, the level of a particular RNA may be reliably determined by RT-PCR even in a total RNA that is usually considered as degraded (28S to 18S ratio as low as 0.4), provided that random primer is used in RT. In contrast, the use of the oligo(dT) primer in RT-PCR may lead to underestimation of specific mRNA level in the degraded RNA samples, depending on the distance of amplified fragment from the poly(A) end. A criterion based on average degradation level of a number of reference genes is suggested to discriminate specific RNA degradation from random and unspecific ones.     

A Study of the Structure of Trypsin-Like Serine Proteinases: 1. Study of Mini-Plasminogen Activation Using Tryptophan Fluorescence

Biophysics - Abstract—It has been shown that the curve of the time dependence of tryptophan fluorescence during plasminogen activation by urokinase is well correlated with kinetic curves of...