[Role of neuraminidase in pathogenesis of influenza]. / Rol' neiraminidazy v patogeneze grippozonoi infektsii.

The influenza neuraminidase (NA) possesses, both in vivo and in vitro, the anticoagulant and fibrinolytic activity. A computerized comparative analysis of the influenza NA viruses, type A, showed nine regions of amino-acid sequences compatible with the tissue activator of human plasminogen. The mentioned regions are highly conservative for each NA subtype irrespective of a source or a year, when an influenza strain was isolated. The role of NA in pathogenesis of influenza infection is under consideration.

[Usage of polymerase chain reaction in complex diagnosis of hepatitis B]. / Primenenie polimeraznoi tsepnoi reaktsii v kompleksnoi diagnostiki gepatita B.

Sera from 926 patients were analyzed by PCR using universal primers to surface gene of hepatitis B virus (HBV). HBV DNA was detected in 195 specimens. There were no serological markers of HBV in 8.2% of these sera, but later they were detected in patients' sera. In patients without HBV DNA in the serum, specific HBV antigens and antibodies were detected in 62%. Only in 14% of them the clinical picture of the disease corresponded to acute viral hepatitis, although the blood for PCR analysis was collected during the late stages of the infection. The rest cases were referred to mixed hepatitis C + D. Comparison of the results of PCR test and detection of serological virus replication markers HBeAg and HBeAb showed the presence of HBV DNA in 28% cases without HBeAg.

[Determination of nucleotide sequences of Russian isolates of delta hepatitis virus]. / Opredelenie nukleotidnykh posledovatel'nostei rossiiskikh izoliatov virusa gepatita del'ta.

Genome RNA of hepatitis Delta virus (HDV) was isolated from the blood sera of 4 independently infected patients. The genome fragment of 901-1265 was obtained for each isolate by the RT-PCR. The resultant sequences showed that all isolates belonged to HDV genotype I. Russian isolates were shown to be closely related to an Italian one (98.1-97.5% and 97.1-95.1% identity for the nucleic acid and amino acid levels, respectively); they may represent an extra subtype within genotype I. No appreciable differences between the Russian strains were found, which fact may reflect a possible homogeneity of HDV population in North-Western Russia.