[Problems of diagnosis of the hepatitis B virus].

The recent data on the genetic variability of the hepatitis B virus and problems of serological ELISA-mediated detection of this virus are discussed.

[Heterogeneity of hepatitis B virus and diagnostic potential of modern test systems for the detection of HBsAg].

Aim: Study heterogeneity ofhepatitis B virus in adult patients with chronic hepatitis B and determination of diagnostic potential of modern test systems with the detection of HBsAg with amino acid substitutions in the main hydrophilic region (MHR).

Materials And Methods: In 27 hepatitis B virus samples isolated from patients with chronic hepatitis B virus infection living in Vladimir, nucleotide sequence ofgenome region corresponding to preS1/preS2/S genes was determined.

Results: In all of the 27 isolates genotype D virus presented by 3 subgenotypes D1, D2, D3 was detected in 18%, 26% and 56% respectively.

[Impact of changes in the amino acid sequence of the "a" determinant on the diagnostic capacities of test systems for the detection of HBsAg].

The diagnostic capacities of 4 commercial test systems were comparatively estimated for the detection of HBsAg, by applying a panel of samples with the established amino acid sequence of the "a" determinant of HBsAg. The Roche Elecsys HBsAg test system demonstrated the highest sensitivity - the maximum HBsAg concentrations were found in 19 of 31 cases. Escape mutations in the major hydrophilic region (MHR) of HBsAG (P120S, M133T) were responsible for differences in the sensitivity of 4 test systems by 10- to 40-fold.

[Ultrasonic coagulometry as a method of testing compounds with antiplasmin activity].

An ultrasonic interferometer has been used to study the process of fibrin clot lysis according to the decrease in the rate of propagation of an ultrasonic wave in the latter. A significant decrease in the sound fall rate on adding epsilon-aminocaproic and trans-4-aminomethylcyclohexanecarbonic acids to the system indicates their activity inhibiting fibrinolysis. N-nicotinoyl derivatives of this compounds possess less pronounced antiplasmin activity.