DETERMINATION OF OPTIMAL POSITION OF SOLAR COLLECTOR

The paper is devoted to the determination of optimal position of solar collector in Sverdlovsk region to receive the maximum amount of solar energy. Total amount of direct solar radiation was calculated at various angles of inclination and rotation of the surface.В работе определено оптимальное положение солнечного коллектора на территории Свердловской области для улавливания максимального количества солнечной энергии. Рассчитаны суммарные поступления прямой солнечной радиации при различных ориентациях и углах наклона коллектора

Evaluation of Intra-Host Variants of the Entire Hepatitis B Virus Genome

Genetic analysis of hepatitis B virus (HBV) frequently involves study of intra-host variants, identification of which is commonly achieved using short regions of the HBV genome. However, the use of short sequences significantly limits evaluation of genetic relatedness among HBV strains. Although analysis of HBV complete genomes using genetic cloning has been developed, its application is highly labor intensive and practiced only infrequently. We describe here a novel approach to whole genome (WG) HBV quasispecies analysis based on end-point, limiting-dilution real-time PCR (EPLD-PCR) for amplification of single HBV genome variants, and their subsequent sequencing. EPLD-PCR was used to analyze WG quasispecies from serum samples of patients (n = 38) infected with HBV genotypes A, B, C, D, E and G. Phylogenetic analysis of the EPLD-isolated HBV-WG quasispecies showed the presence of mixed genotypes, recombinant variants and sub-populations of the virus. A critical observation was that HBV-WG consensus sequences obtained by direct sequencing of PCR fragments without EPLD are genetically close, but not always identical to the major HBV variants in the intra-host population, thus indicating that consensus sequences should be judiciously used in genetic analysis. Sequence-based studies of HBV WG quasispecies should afford a more accurate assessment of HBV evolution in various clinical and epidemiological settings

Epidemic History and Evolutionary Dynamics of Hepatitis B Virus Infection in Two Remote Communities in Rural Nigeria

BACKGROUND: In Nigeria, hepatitis B virus (HBV) infection has reached hyperendemic levels and its nature and origin have been described as a puzzle. In this study, we investigated the molecular epidemiology and epidemic history of HBV infection in two semi-isolated rural communities in North/Central Nigeria. It was expected that only a few, if any, HBV strains could have been introduced and effectively transmitted among these residents, reflecting limited contacts of these communities with the general population in the country. METHODS AND FINDINGS: Despite remoteness and isolation, approximately 11% of the entire population in these communities was HBV-DNA seropositive. Analyses of the S-gene sequences obtained from 55 HBV-seropositive individuals showed the circulation of 37 distinct HBV variants. These HBV isolates belong predominantly to genotype E (HBV/E) (n=53, 96.4%), with only 2 classified as sub-genotype A3 (HBV/A3). Phylogenetic analysis showed extensive intermixing between HBV/E variants identified in these communities and different countries in Africa. Quasispecies analysis of 22 HBV/E strains using end-point limiting-dilution real-time PCR, sequencing and median joining networks showed extensive intra-host heterogeneity and inter-host variant sharing. To investigate events that resulted in such remarkable HBV/E diversity, HBV full-size genome sequences were obtained from 47 HBV/E infected persons and P gene was subjected to Bayesian coalescent analysis. The time to the most recent common ancestor (tMRCA) for these HBV/E variants was estimated to be year 1952 (95% highest posterior density (95% HPD): 1927-1970). Using additional HBV/E sequences from other African countries, the tMRCA was estimated to be year 1948 (95% HPD: 1924-1966), indicating that HBV/E in these remote communities has a similar time of origin with multiple HBV/E variants broadly circulating in West/Central Africa. Phylogenetic analysis and statistical neutrality tests suggested rapid HBV/E population expansion. Additionally, skyline plot analysis showed an increase in the size of the HBV/E-infected population over the last approximately 30-40 years. CONCLUSIONS: Our data suggest a massive introduction and relatively recent HBV/E expansion in the human population in Africa. Collectively, these data show a significant shift in the HBV/E epidemic dynamics in Africa over the last century

Hepatitis C virus infections from a contaminated radiopharmaceutical used in myocardial perfusion studies

Context: Nuclear pharmacies prepare radiopharmaceutical products for use in common diagnostic procedures, including myocardial perfusion studies. Hepatitis C virus (HCV) transmission has not been reported previously in the setting of nuclear imaging studies. Objective: To investigate an outbreak of acute HCV infection identified among patients who underwent myocardial perfusion studies on October 15, 2004, using an injected radiopharmaceutical. Design, Setting, and Patients: Outbreak investigation including molecular epidemiology and pharmacy site investigation at outpatient cardiology clinics and a nuclear pharmacy in Maryland. Ninety patients who received injections drawn from select radiopharmaceutical vials prepared on October 14-15, 2004, at a single nuclear pharmacy were offered testing for bloodborne pathogens. Pharmacy procedures were reviewed and HCV quasi species analysis was performed. Main Outcome Measures: Hepatitis C virus infection and quasispecies sequence similarity. Results: Sixteen patients with acute HCV infection were identified from 3 separate clinics. All patients received radiopharmaceutical injections drawn from a single pharmacy vial (vial 1). None of the 59 tested patients who received doses from 6 other vials had acute HCV infection. Blood from a potential source patient with HCV and human immunodeficiency virus (HIV) infection was processed for a radiolabeled white blood cell study in the pharmacy 12 hours before vial 1 was prepared. The HCV quasispecies sequences from this potential source patient were nearly identical to those from cases (97.8%-98.5% similarity). No acute HIV infections were identified. Pharmacy practices that could have led to blood cross-contamination included reuse of needles and syringes during dilutions and use of common flow hoods for some steps in the preparation of sterile and blood-derived products. Conclusions: Sixteen persons acquired HCV infection from a blood-contaminated radiopharmaceutical. The source and practices that could have facilitated breaks in aseptic technique were identified at the pharmacy. Nuclear pharmacies that handle biological products should follow appropriate aseptic technique to prevent contamination of sterile radiopharmaceuticals. ©2006 American Medical Association. All rights reserved

Reactivation of a vaccine escape hepatitis B virus mutant in a Cambodian patient during anti-hepatitis C virus therapy

A 76-year-old Cambodian man co- infected with hepatitis B virus (HBV) and hepatitis C virus (HCV) 6c-1 presented for care. HBV DNA was intermittently detectable despite anti-HBs levels being above the protective threshold. During treatment for HCV, HBV DNA levels increased. Sequencing revealed multiple mutations including vaccine escape mutation and mutations predicted to enhance fitness. This case represents exacerbation of an HBV vaccine escape mutant during a direct-acting antiviral therapy

Reactivation of a vaccine escape hepatitis B virus mutant in a Cambodian patient during anti-hepatitis C virus therapy

A 76-year-old Cambodian man co- infected with hepatitis B virus (HBV) and hepatitis C virus (HCV) 6c-1 presented for care. HBV DNA was intermittently detectable despite anti-HBs levels being above the protective threshold. During treatment for HCV, HBV DNA levels increased. Sequencing revealed multiple mutations including vaccine escape mutation and mutations predicted to enhance fitness. This case represents exacerbation of an HBV vaccine escape mutant during a direct-acting antiviral therapy