Prevalence of occult hepatitis B infection among blood donors in Saint Petersburg

The aim of this study was to assess the prevalence of occult hepatitis B infection among blood donors in St. Petersburg, as well as to characterize the identified virus isolates. The study material was represented by 2800 blood plasma samples collected in 2019 from blood donors living in St. Petersburg. The ELISA study for HBV marker rate consisted of HBsAg, anti-HBs IgG, anti-HBcore IgG. HBV DNA was analyzed by nested PCR with real-time hybridization-fluorescence detection on three targets allowing to determine virus DNA at low viral load, including HBsAg-negative chronic hepatitis B. Hepatitis B serological markers were detected in 69.43% of those surveyed, HBsAg was found in 0.43% of individuals, and all of which donated blood first time. A significant excess of the anti-HBcore IgG antibodies occurrence among primary donors (15.1%) compared with repeated/regular donors (7.48%) was shown. The prevalence of virus DNA in the group was 3.14%, including 2.71% of cases in HBsAg-negative CHB. Based on phylogenetic analysis of 88 isolates, HBV subgenotypes were determined in the following order: D1 and D2, 40.91% each, D3 and A2, 9.09% each. While determining the serological subtype in detected isolates, the serotype ayw3 (52.27%) vs ayw2 (46.59%) and adw2 (10.23%) prevailed. Drug resistance mutations, including compensatory ones, were detected in six examined patients (6.82%). In all genotype D isolates, multiple amino acid substitutions were identified in the RT, SHB, MHB, LHB, and Core regions; mutations in the preCore region were detected in 21.59% samples. In the MHR of the HBV genotype D genome, twenty-six positions were identified in which amino acid substitutions occurred, and all isolates showed modifications at positions 113, 114, 131, 134, 159, 161, 168, in 76 — at position 122, in 68 — at position 127, in 36 — at position 118, in 24 — at position 128. In HBV A2 isolates, mutations T113S, S143T, Y161F were identified. Nine isolates in the preCore region showed a polymorphism including a stop codon W28*W; in five isolates the W28S substitution was shown in the same position, and the W28*S variant was found in one more sample. The high incidence of HBsAg-negative CHB cases among blood donors, as well as the predominance of HBV isolates that simultaneously carry mutations resulting in diagnostic failure of HBsAg tests and prophylactic failure of immunoglobulin or vaccines and virus reactivation, mutations that contribute to disease progression obviously pose a threat to health and require to be further examined

Safety and efficacy of convalescent plasma for COVID-19: the preliminary results of a clinical trial

Background. The lack of effective etiotropic therapy for COVID-19 has prompted researchers around the globe to seekr various methods of SARS-CoV-2 elimination, including the use of convalescent plasma. Aim. The aim of this work was to study the safety and efficacy of the convalescence plasma treatment of severe COVID-19 using the plasma containing specific antibodies to the receptor binding domain (RBD) of SARS-CoV-2 S protein in a titer of at least 1:1000. Methods. A single-center, randomized, prospective clinical study was performed at the FRCC FMBA of Russia with the participation of 86 patients who were stratified in two groups. The first group included 20 critically ill patients who were on mechanical ventilation the second group included 66 patients with moderate to severe COVID-19 and with spontaneous respiration. The patients in the second group were randomized into two cohorts in a ratio of 2:1. In the first cohort (46 patients), pathogen-reduced convalescent plasma was transfused (twice, 320 ml each), in the second cohort (20 patients) a similar amount of non-immune freshly frozen plasma was transfused to the patients. Results. The use of plasma of convalescents in patients with severe COVID-19 being on mechanical ventilation does not affect the disease outcome in these patients. The mortality rate in this group was 60%, which corresponds to the average mortality of COVID patients on mechanical ventilation in our hospital. In the second group, clinical improvement was detected in 75% and 51%, for convalescent and non-immune plasma, respectively. Of the 46 people who received convalescent plasma, three patients (6.5%) were transferred to mechanical ventilation, two of them died. In the group receiving non-immune plasma, the need for mechanical ventilation also arose in three patients (15%), of which two died. The hospital mortality in the group of convalescent plasma was 4.3%, which is significantly lower than the average COVID-19 hospital mortality at our Center (6.73%) and more than two times lower than the hospital mortality in the control group (n=150), matched by age and by the disease severity. Conclusions. Thus, we demonstrated a relative safety of convalescent plasma transfusion and the effectiveness of such therapy for COVID-19 at least in terms of the survival of hospitalized patients with severe respiratory failure without mechanical ventilation. In the absence of bioengineered neutralizing antibodies and effective etiotropic therapy, the use of hyperimmune convalescent plasma is the simplest and most effective method of specific etiopathogenetic therapy of severe forms of COVID-19

Application of the robotized mechanotherapy for patients with motive violations in the late recovery period

Aim. To study effectiveness of use of robotic devices with software support and patient-specific feedback Armeo and Amadeo in the late stroke recovery period. Materials and methods. The study included 65 patients (30 male, 35 female) aged from 18 to 86 years. The study participants were randomized into 2 groups: in group 1 (study group; n=33) neurorehabilitation course included robotic devices with software support and patient-specific feedback Armeo and Amadeo use for 18 days 2 times a day; in group 2 (n=32) a standard rehabilitation course was conducted. Results. Rehabilitation course with the use of robotic devices in late stroke recovery period in group 1 resulted in better improvement of upper extremity motor function in comparison with standard rehabilitation methods. Conclusion. The use of robotic devices with software support and patient-specific feedback Armeo and Amadeo in neurological function recovery in patients in the late stroke recovery period increases the effectiveness of rehabilitation course in comparison with standard rehabilitation methods

Transformation of Apple Composition during Cider Production

Cider is obtained by fermenting mashed apples of special cider varieties. The Russian State Register of Selection Achievements includes 476 varieties of apples, some of which can be used in commercial cider production. To identify potential cider cultivars, food scientists study the transformation of chemicals in apple mash during fermentation. The research involved 16 samples of apple mash and cider obtained from apples of foreign and domestic selection. Their physicochemical, biochemical, and sensory parameters were identified using standard methods, as well as the methods of high-performance capillary electrophoresis and gas chromatography. The samples revealed a wide range of concentrations of titratable acids, phenolic substances, ascorbic acids, and phenolcarboxylic acids, depending on the cultivar. After fermentation, the content of ascorbic acid decreased by an average of 76%. The content of phenolcarboxylic acids in the cider samples increased by an average of 51% compared with the apple mash samples. The ciders contained succinic, oxalic, lactic, and acetic acids, which were not registered in the apple mash, and the concentration of amino acids doubled. The cider from the Virginia variety had the best sensory profile, and it also had the highest concentration of phenolic substances (1121.6 mg/dm3). In this research, the best characteristics belonged to the ciders from apple varieties with a complex interspecific origin, obtained by a complex of polyploidy and distant hybridization methods, and with high concentrations of sugars and phenolic substances in the apple mash. Further research will test varieties of other origins and physicochemical properties for their potential use in cider, vodka, and calvados production