Genetic polymorphisms in the C19orf66 gene influenced HIV-1 infection in a Yunnan population.

Background: Due to the deficiencies of vaccines and effective medicine, the human immunodeficiency virus (HIV) infection mechanism should be studied. The C19orf66 gene, one of the interferon-stimulated genes (ISGs), expresses broad-spectra anti-viral activity, including inhibiting HIV replication. Methods: In this study, we collect 421 HIV-1 infected patients and 448 controls to genotype three SNPs in the C19orf66 gene. Then, the association between SNPs and biochemical indices/ HIV-1 subtypes are analyzed. Results: Genotypes CC and CT of rs12611087 show statistically lower and higher frequencies in HIV-1 infected patients than in controls, respectively. Alleles C and T of rs12611087 play protective and risk roles in Yunnan HIV population, respectively. Biochemical indices analysis shows that HIV-1 infected persons carried genotype TT of rs77076061 express significantly lower CD3+/CD45+ ratio level and higher IBIL level. The epidemic subtypes of HIV-1 patients in this study are CRF 07_BC and CRF 08_BC. Moreover, subtype CRF 08_BC tends to infect persons with genotype CC of rs12611087. Conclusion: The genetic polymorphisms of the C19orf66 gene are firstly studied and reported to associate with HIV-1 infection and biochemical indices of patients in Yunnan. Furthermore, subtype CRF 08_BC infection could be influenced by genotypes of SNP in the C19orf66 gene.

Characterization of a Novel Hepatitis C Subtype, 6xj, and Its Consequences for Direct-Acting Antiviral Treatment in Yunnan, China.

Hepatitis C virus (HCV) has a high rate of genetic variability, with eight genotypes and 91 subtypes. The genetic diversity of HCV genotype 6 (HCV-6) is the highest with 31 subtypes, and this genotype is prevalent in Southeast Asia. In this study, we investigated 160 individuals with chronic hepatitis C in Yunnan Province, China. Using reverse transcription (RT)-PCR and Sanger sequencing, 147 cases were successfully amplified and genotyped as 3b (4.9%), 3a (19.73%), 6n (12.24%), 1b (7.48%), 2a (6.12%), 6a (2.04%), 1a (0.68%), 6v (0.68%), and 6xa (0.68%), with eight sequences remaining unclassified. Subsequently, the eight nearly full-length genomes were successfully amplified and analyzed. The eight complete coding sequences formed a phylogenetic group that was distinct from the previously assigned HCV-6 subtypes and clustered with two previously unnamed HCV-6 sequences. Furthermore, Simplot analysis showed no recombination and the p-distance was more than 15% in comparison to the 6a to 6xi subtypes. Taken together, we identified a new HCV-6 subtype, 6xj, which originated approximately in 1775 according to Bayesian analyses. Moreover, all eight individuals received follow-up assessments at 44 weeks from the beginning of their 12-week treatments of sofosbuvir/velpatasvir (after-treatment week 32). One case relapsed at after-treatment week 32. Next-generation sequencing (NGS) was conducted and showed that the treatment failure case had two suspected antiviral resistance mutations, NS5A V28M (a change of V to M at position 28) and NS5B A442V, compared with the baseline. Overall, this newly identified 6xj subtype further confirmed the high diversity of the HCV-6 genotype. The newly identified resistance-associated amino acid substitutions may help inform future clinical treatments. IMPORTANCE This study investigated the genetic diversity of hepatitis C virus (HCV), particularly in relation to genotype 6, which is prevalent in Yunnan, China, and is often difficult to treat successfully. We identified a new HCV-6 subtype, 6xj, which is an ancient strain. Moreover, all eight individuals with the novel subtype received follow-up assessments at 44 weeks from the beginning of their treatments. One case relapsed after 8 months of withdrawal. NGS was conducted and showed that the isolate from the treatment failure case had two suspected antiviral resistance mutations, NS5A V28M and NS5B A442V, compared with the baseline. Overall, this newly identified 6xj subtype further confirmed the high diversity of the HCV-6 genotype. The newly identified resistance-associated amino acid substitutions may help inform future clinical treatments. We believe that our study makes a significant contribution to the literature based on the results described above.

Environment-Friendly Preparation of Reaction-Bonded Silicon Carbide by Addition of Boron in the Silicon Melt.

Reaction-bonded silicon carbide ceramics were sintered by infiltration of Si and B-Si alloy under an argon atmosphere at different temperatures. The element boron was added to the silicon melt to form a B-Si alloy first. The mechanical properties of samples were improved by infiltration of the B-Si melt. The samples infiltrated with the Si-only melt were found to be very sensitive to experimental temperature. The bending strengths of 58.6 and 317.0 MPa were achieved at 1530 and 1570 °C, respectively. The sample made by infiltration of B-Si alloy was successfully sintered at 1530 °C. The relative density of the sample was more than 90%. The infiltration of B-Si alloy reduced the sintering temperature and the bending strength reached 326.9 MPa. The infiltration mechanism of B-Si alloy is discussed herein.