Use of the polymerase chain reaction for analysis of rotaviruses. Nucleotide sequence of a gene, coding for the basic neutralizing antigen VR7 of a human rotavirus with a new G-serotype

A procedure based on polymerase chain reaction use for the detection of rotavirus has been developed. Full length cDNA copy of the VP7 gene coding for the major neutralization glycoprotein of the human rotavirus RK9 with an unusual "wide" electrophoretype is cloned and sequenced. Glycoprotein VP7 of RK9 has a unique amino acid composition in A and C antigenic regions. It shows that strain RK9 represents a new (12) rotavirus serotype.     

Use of cefoperazone in clinical practice]

The bacteriological and clinical efficacy and side effects of cefoperazone were studied in 45 patients with severe and moderate purulent inflammatory diseases. The study showed that its bacteriological and clinical efficacy was high in cases with peritonitis, cholecystitis, respiratory and urinary infections, as well as those of the eye and soft tissues. The general clinical efficacy amounted to 95.6 per cent. The number of the side effects was insignificant. This made it possible to recommend the use of cefoperazone in the therapy of many purulent inflammatory diseases, as well as in empirical therapy.     

An efficient method for genetic certification of <Emphasis Type="Italic">Bacillus subtilis</Emphasis> strains,prospective producers of biopreparations

Genetic certification of commercial strains of bacteria antagonistic to phytopathogenic microorganisms guarantees their unequivocal identification and confirmation of safety. In Russia, unlike EU countries, genetic certification of Bacillus subtilis strains is not used. Based on the previously proposed double digestion selective label (DDSL) fingerprinting, a method for genetic identification and certification of B. subtilis strains was proposed. The method was tested on several strains differing in their physiological and biochemical properties and in the composition of secondary metabolites responsible for the spectrum of antibiotic activity. High resolving power of this approach was shown. Optimal restriction endonucleases (SgsI and Eco32I) were determined and validated. A detailed protocol for genetic certification of this bacterial species was developed. DDSL is a universal method, which may be adapted for genetic identification and certification of other bacterial species. Keywords: genotyping, restriction     

A comparative analysis of the spatial structure of nonspecific porins from <Emphasis Type="Italic">Yersinia ruckeri</Emphasis> using optical spectroscopy and molecular modeling

The spatial organization of outer-membrane porins is studied by optical spectroscopy and molecular modeling. It was found that the OmpF and OmpC porins from Yеrsiniа ruckeri are β-structured membrane proteins typical of the pore-forming proteins of other Gram-negative bacteria. The spatial structures of monomers and trimers of the OmpC and OmpF porins from Y. ruckeri are simulated using methods of structural bioinformatics. It was found that the structural stability of the more thermostable OmpF trimer is sustained by a greater number of hydrogen bonds and hydrophobic interactions. The main differences of the spatial structures of the test porins are observed in the structure of their outer loops. There are three tryptophan residues in the molecules of the OmpC and OmpF porins of Y. ruckeri. It is demonstrated by moleculardynamics methods that after thermal denaturation the solvent accessibility of the Trp212 residue in OmpF porin increased by two times, while the solvent accessibility of a Trp184 residue in OmpC porin was not increased. It is hypothesized that the red-shifted tryptophan fluorescence spectrum of OmpF porin during thermal denaturation is due to the behavior of the Trp212 residue.     

Adverse effects of tempol on hidrosaline balance in rats with acute sodium overload

We studied the effects of tempol, an oxygen radical scavenger, on hydrosaline balance in rats with acute sodium overload. Male rats with free access to water were injected with isotonic (control group) or hypertonic saline solution (0.80 mol/l NaCl) either alone (Na group) or with tempol (Na-T group). Hydrosaline balance was determined during a 90 min experimental period. Protein expressions of aquaporin 1 (AQP1), aquaporin 2 (AQP2), angiotensin II (Ang II) and endothelial nitric oxide synthase (eNOS) were measured in renal tissue. Water intake, creatinine clearance, diuresis and natriuresis increased in the Na group. Under conditions of sodium overload, tempol increased plasma sodium and protein levels and increased diuresis, natriuresis and sodium excretion. Tempol also decreased water intake without affecting creatinine clearance. AQP1 and eNOS were increased and Ang II decreased in the renal cortex of the Na group, whereas AQP2 was increased in the renal medulla. Nonglycosylated AQP1 and eNOS were increased further in the renal cortex of the Na-T group, whereas AQP2 was decreased in the renal medulla and was localized mainly in the cell membrane. Moreover, p47-phox immunostaining was increased in the hypothalamus of Na group, and this increase was prevented by tempol. Our findings suggest that tempol causes hypernatremia after acute sodium overload by inhibiting the thirst mechanism and facilitating diuresis, despite increasing renal eNOS expression and natriuresis.     

Effects of sombrevine on orientational tuning of visual cortex neurons in the cat

Changed orientational tuning (OT) in 58 visual cortex units was investigated during acute experiments on immobilized cats under light short-lasting sombrevine-induced anesthesia. A 47.6±5.6° alteration in the preferred orientation of 60% of cells occurred following sombrevine injection but no change occurred at any stage of anesthesia in the remainder. The latter group showed a preference for horizontal and vertical orientations, less pronounced in the former category. "Stable" neurons also displayed less acute tuning and more selective detection in comparison with "unstable" units. Breadth of orientational tuning consistently changed by an average of 65.2±6.7° in 55% of neurons, while tuning deteriorated in 31% and sharpened in 24% of cells. No regular change in tuning band occurred in the remainder. Background firing rate and evoked spike activity declined by 58% and 35%, respectively under anesthesia in 2/3 of the cells tested. Tuning bandwidth of unit firing rate had generally recovered within 20–40 min after administering the anesthetic (i.e., as the anesthesia wore off).Higher Nervous Activity and Neurophysiology Research Institute. Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 21, No. 6, pp. 812–820, November–December, 1989.     

Radioprotective activity of aminoarylthiazoles and various mechanisms of action

The amino group is shown to be the reaction center that is primarily responsible for the radioprotective effect of the thiazoles under study. A phenyl residue also contributes to the radioprotective effect. The influence of thiazoles on DNA biosynthesis on radiosensitive tissues plays an important role in the biochemical mechanism of their radioprotective action.     

Structural organization of kinetoplast DNA and its compaction in the in vitro model system.

Electron microscopic studies of Leishmania gymnodactyli cells lysed at hypotonic conditions showed that the structures identified as kinetoplast DNA have the appearance of loose accumulations of crossed and sometimes branched rod-like structures 100 to 200 nm long and 20 nm thick. The compaction of isolated kinetoplast DNA (kpDNA) caused by interaction with synthetic tripeptide--dansylhydrazide trivaline--was also studied. The analysis of the structures arising at different steps of compaction showed that the minicircles are compacted forming rod-like structures where minicircle double-stranded DNA segments are closely associated side by side in a manner which was earlier described for initial compaction stages of "triple rings". These rod-like structures resemble in their appearance the structures found in lysed cell preparations obtained according to Miller's method. Branching of rod-like structures can be the consequence of minicircle catenation. In vitro compaction is completed with the formation of a compacted network, its diameter being 3 to 6 times smaller as compared with the initial one.