Since the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that caused coronavirus disease 2019 (COVID-19), the use of face masks has become ubiquitous in China and other Asian countries such as South Korea and Japan. Some provinces and municipalities in China have enforced compulsory face mask policies in public areas; however, China's national guideline has adopted a risk-based approach in offering recommendations for using face masks among health-care workers and the general public. We compared face mask use recommendations by different health authorities (panel). Despite the consistency in

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Variable immune responses to hepatitis B virus (HBV) infection and recombinant HBV

BackgroundDuring untreated, chronic HIV-1 infection, plasma viral load (VL) is a relatively stable quantitative trait that has clinical and epidemiological implications. Immunogenetic research has established various human genetic factors, especially human leukocyte antigen (HLA) variants, as independent determinants of VL set-point.Methodology/Principal FindingsTo identify and clarify HLA alleles that are associated with either transient or durable immune control of HIV-1 infection, we evaluated the relationships of HLA class I and class II alleles with VL among 563 seroprevalent Zambians (SPs) who were seropositive at enrollment and 221 seroconverters (SCs) who became seropositive during quarterly follow-up visits. After statistical adjustments for non-genetic factors (sex and age), two unfavorable alleles (A*3601 and DRB1*0102) were independently associated with high VL in SPs (p<0.01) but not in SCs. In contrast, favorable HLA variants, mainly A*74, B*13, B*57 (or Cw*18), and one HLA-A and HLA-C combination (A*30+Cw*03), dominated in SCs; their independent associations with low VL were reflected in regression beta estimates that ranged from −0.47±0.23 to −0.92±0.32 log10 in SCs (p<0.05). Except for Cw*18, all favorable variants had diminishing or vanishing association with VL in SPs (p≤0.86).Conclusions/SignificanceOverall, each of the three HLA class I genes had at least one allele that might contribute to effective immune control, especially during the early course of HIV-1 infection. These observations can provide a useful framework for ongoing analyses of viral mutations induced by protective immune responses.

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Objectives To evaluate the associations of regular glucosamine use with all-cause and cause-specific mortality in a large prospective cohort. Methods This population-based prospective cohort study included 495 077 women and men (mean (sd) age, 56.6 (8.1) years) from the UK Biobank study. participants were recruited from 2006 to 2010 and were followed up through 2018. We evaluated all-cause mortality and mortality due to cardiovascular disease (cVd), cancer, respiratory and digestive disease. HRs and 95% cis for all-cause and cause-specific mortality were calculated using cox proportional hazards models with adjustment for potential confounding variables. results at baseline, 19.1% of the participants reported regular use of glucosamine supplements. during a median follow-up of 8.9 years (iQR 8.3-9.7 years), 19 882 all-cause deaths were recorded, including 3802 cVd deaths, 8090 cancer deaths, 3380 respiratory disease deaths and 1061 digestive disease deaths. in multivariable adjusted analyses, the HRs associated with glucosamine use were 0.85 (95% ci 0.82 to 0.89) for all-cause mortality, 0.82 (95% ci 0.74 to 0.90) for cVd mortality, 0.94 (95% ci 0.88 to 0.99) for cancer mortality, 0.73 (95% ci 0.66 to 0.81) for respiratory mortality and 0.74 (95% ci 0.62 to 0.90) for digestive mortality. The inverse associations of glucosamine use with all-cause mortality seemed to be somewhat stronger among current than non-current smokers (p for interaction=0.00080). Conclusions Regular glucosamine supplementation was associated with lower mortality due to all causes, cancer, cVd, respiratory and digestive diseases.on July 9, 2020 by guest. Protected by copyright.

fIn HIV-1 infection, the early set-point viral load strongly predicts both viral transmission and disease progression. The factors responsible for the wide spectrum of set-point viral loads are complex and likely reflect an interplay between the transmitted virus and genetically defined factors in both the transmitting source partner and the seroconverter. Indeed, analysis of 195 transmission pairs from Lusaka, Zambia, revealed that the viral loads in transmitting source partners contributed only ϳ2% of the variance in early set-point viral loads of seroconverters (P ‫؍‬ 0.046 by univariable analysis). In multivariable models, early setpoint viral loads in seroconverting partners were a complex function of (i) the viral load in the source partner, (ii) the gender of the seroconverter, (iii) specific HLA class I alleles in the newly infected partner, and (iv) sharing of HLA-I alleles between partners in a transmission pair. Each of these factors significantly and independently contributed to the set-point viral load in the newly infected partner, accounting for up to 37% of the variance observed and suggesting that many factors operate in concert to define the early virological phenotype in HIV-1 infection. The HIV-1 set-point viral load (VL) in infected individuals directly affects the transmission rate of the virus (1-3) and early disease progression (4-6). Recent studies have shown a trend of increasing set-point VLs over the last 30 years of the HIV-1 epidemic (7, 8), raising the possibility of both increasing transmission rates and virulence in treatment of naïve HIV-1 infection. A plausible explanation for this observation is viral adaptation to the host at the population level over time (9, 10), providing a further challenge for HIV-1 vaccine design. The determinants of set-point VL in newly infected individuals include viral genetic factors (11-13) and host genetic factors (14-16). Thus, to comprehensively define the role of underlying factors in determining early set-point VL, it is necessary to understand the complexity of the interaction between the transmitted founder virus, with its embedded footprints of the immune response of the transmitting source partner (TSP), and the de novo immune defense of the seroconverting partner (SC).We previously observed that cytotoxic T-lymphocyte (CTL) epitope escape mutations selected by immune pressure in the TSP can modulate the early set-point VL in the SC (11, 17), suggesting that mutations that would be expected to positively impact VL in the TSP can negatively impact VL in the seroconverter. This observation is consistent with our previous studies of the ZEHRP cohort and with other studies of heterosexual cohorts of limited size. These studies demonstrated a relatively weak correlation between VLs in TSPs and SCs in linked heterosexual transmission partners (18)(19)(20). In contrast, a more significant VL correlation was shown for a transmission pair cohort of men who have sex with men (MSM) in San Francisco (21), and a phylogenetic analysis of MSM in the Swi...

The roles of immunodeficiency and combined antiretroviral therapy (cART) in shaping the gut microbiota in HIV-1-infected subjects (HISs) have not been described thoroughly by time-series investigations. In this study, 36 antiretroviral-naïve HISs were enrolled to prospectively assess alterations in the fecal microbiota and plasma markers of microbial translocation and inflammation with cART. At baseline, the species α-diversity of the fecal microbiota was significantly lower in HISs with a CD4+ T cell count <300/mm3 than in HISs with a CD4+ T cell count >300/mm3 (Shannon index: Median 2.557 vs. 2.981, P = 0.006; Simpson index: Median 0.168 vs. 0.096, P = 0.004). Additionally, the baseline α-diversity indices correlated with CD4+ T cell counts (Shannon index: r = 0.474, P = 0.004; Simpson index: r = −0.467, P = 0.004) and the specific plasma biomarkers for microbial translocation and inflammation. After cART introduction, the species α-diversity of fecal microbiota in HISs with CD4+ T cell counts <300/mm3 was significantly restored (Shannon index: Median 2.557 vs. 2.791, P = 0.007; Simpson index: Median 0.168 vs. 0.112, P = 0.004), while the variances were insignificant among HISs with CD4+ T cell counts >300/mm3 (Shannon index: Median 2.981 vs. 2.934, P = 0.179; Simpson index: Median 0.096 vs. 0.119, P = 0.082). Meanwhile, with cART introduction, alterations in the gut microbial composition were more significant in the subgroup with CD4+ T cell counts >300/mm3, corresponding to increases in the specific plasma inflammatory markers. These findings implicated the interactive roles of immunodeficiency and cART for affecting gut microbiota in HIV-1-infected individuals, providing new insights into intestinal microbiome dysbiosis related to HIV-1 infection.