Publications by authors named "Sergey Firsov"

2 Publications

  • Page 1 of 1

HBsAg level and hepatitis B viral load correlation with focus on pregnancy.

Ann Gastroenterol 2015 Jul-Sep;28(3):379-384

St. Petersburg State University, St. Petersburg, Russia (Alexey Yakovlev).

Background: Viral load measurement is necessary to estimate mother-to-child transmission risk for women with chronic hepatitis B (CHB), however, it is expensive. The present study aimed to investigate the relationship between HBsAg and hepatitis B virus (HBV) DNA levels, and to determine potential applications of HBsAg level monitoring for estimating viral load.

Methods: 85 patients with CHB (31 pregnant women, 26 non-pregnant women, 28 men) were included in the study. HBV DNA level was measured by real-time PCR, and HBsAg level by chemiluminescent immunoassay method. Dependency between viral load and HBsAg level was determined by Spearman correlation coefficient ρ.

Results: The correlation between HBsAg and HBV DNA levels was significant for all patients [ρ=0.3762 (P<0.0005; n=85)]. In the group of pregnant women, a low (unmeasurable) HBV DNA level led to a decrease in the Spearman coefficient ρ. In almost all cases a low level of the HBsAg corresponded to a low HBV DNA level. Only 2 patients had a low level of HBsAg and a relatively high viral load. By contrast, a high HBsAg level was observed in patients both with high and low viral load.

Conclusions: Correlation between HBsAg and HBV DNA levels is significant. In most cases, a low level of HBsAg indicates a low HBV DNA level, whereas a high HBsAg level does not always correspond to a high viral load. The measurement of HBV DNA level is necessary for pregnant women with a high HBsAg level.
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December 2014

Ancient fungi in Antarctic permafrost environments.

FEMS Microbiol Ecol 2012 Nov 23;82(2):501-9. Epub 2012 Jul 23.

All-Russian Collection of Microorganisms (VKM), G K Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.

Filamentous fungi in 36 samples of Antarctic permafrost sediments were studied. The samples collected during the Russian Antarctic expedition of 2007-2009 within the framework of the Antarctic Permafrost Age Project (ANTPAGE) were recovered from different depths in ice-free oases located along the perimeter of the continent. Fungal diversity was determined by conventional microbiological techniques combined with a culture-independent method based on the analysis of internal transcribed spacer (ITS2) sequences in total DNA of the samples. The study revealed a rather low fungal population density in permafrost, although the diversity found was appreciable, representing more than 26 genera. Comparison of the data obtained by different techniques showed that the culture-independent method enabled the detection of ascomycetous and basidiomycetous fungi not found by culturing. The molecular method failed to detect members of the genera Penicillium and Cladosporium that possess small-sized spores known to have a high resistance to environmental changes.
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November 2012