Exploring the biphasic dose-response effects of photobiomodulation on the viability, migration, and extracellular vesicle secretion of human adipose mesenchymal stem cells.

Photobiomodulation (PBM) is a well-established medical technology that employs diverse light sources like lasers or light-emitting diodes to generate diverse photochemical and photophysical reactions in cells, thereby producing beneficial clinical outcomes. In this study, we introduced an 830 nm near-infrared (NIR) laser irradiation system combined with a microscope objective to precisely and controllably investigate the impact of PBM on the migration and viability of human adipose mesenchymal stem cells (hADSCs). We observed a biphasic dose-response in hADSCs' viability and migration after PBM exposure (0-10 J/cm2), with the 5 J/cm2 group showing significantly higher cell viability and migration ability than other groups. Additionally, at the optimal dose of 5 J/cm2, we used nanoparticle tracking analysis (NTA) and found a 6.25-fold increase in the concentration of extracellular vesicles (EVs) derived from hADSCs (PBM/ADSC-EVs) compared to untreated cells (ADSC-EVs). Both PBM/ADSC-EVs and ADSC-EVs remained the same size, with an average diameter of 56 nm measured by the ExoView R200 system, which falls within the typical size range for exosomes. These findings demonstrate that PBM not only improves the viability and migration of hADSCs but also significantly increases the EV yield.

Responses to booster hepatitis B vaccination are significantly correlated with genotypes of human leukocyte antigen (HLA)-DPB1 in neonatally vaccinated adolescents.

Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) near the human leukocyte antigen (HLA)-DP loci that were significantly correlated with outcomes of hepatitis B virus (HBV) infection. We performed a case-control study nested in a well-characterized cohort of booster recipients to assess whether genetic variants of HLA-DPB1 are also associated with response to hepatitis B (HB) vaccination. The cases and controls were 171 and 510 booster recipients whose post-booster titers of antibodies against HBV surface antigen (anti-HBs) were undetectable and detectable, respectively. The HLA-DPB1 genotype was determined using sequence-based techniques. The frequencies of HLA-DPB1 alleles were significantly different between cases and controls (p = 1.7 × 10(-8)). The HLA-DPB1 05:01 and 09:01 alleles were significantly more frequent in the cases, and 02:01:02, 02:02, 03:01:01, 04:01:01, and 14:01, were significantly more frequent in the controls. The adjusted odds ratio (OR) of undetectable post-booster anti-HBs titers was significantly correlated with the number of risk alleles (p for trend = 3.8 × 10(-5)). For the number of protective alleles, the trend was significantly inversed (p for trend = 1.3 × 10(-5)). As compared with subjects with two risk alleles, adjusted OR were 0.34 (95 % confidence interval [CI] 0.21-0.55) and 0.20 (95 % CI 0.08-0.48) for subjects with 1 and 2 protective alleles, respectively. The HLA-DPB1 02:02, 04:01:01, 05:01 and 09:01 alleles were also significantly correlated with the likelihoods of undetectable pre-booster anti-HBs titers. Our results indicated that HLA-DPB1 is significantly correlated with response to booster HB vaccination in adolescent who had received postnatal active HB vaccination. HLA-DBP1 may also determine the long-term persistence of response to HB vaccination.

Prevalence and determinants of SENV viremia among adolescents in an endemic area of chronic liver diseases.

BACKGROUND: SENV is a potential causative agent responsible for chronic liver diseases (CLDs) that are precipitated in early life. SENV prevalence in adolescents is unknown and its transmission route is uncertain. METHODS: We randomly selected 824 serum samples from a cohort of 2383 adolescents aged 15-17 years who resided in Hualien County, an endemic area of liver diseases. Serum SENV genotype-D and genotype-H DNA were assayed by seminested polymerase chain reaction. RESULTS: The positive rates for SENV-D and SENV-H DNA were 25.1% and 30.6%, respectively. Amis adolescents had a significantly higher rate of SENV-D viremia than Han Chinese adolescents (31.0%vs 22.2%; P = 0.025). Adolescents residing in rural or mountainous areas had significantly higher rates of SENV-H viremia than those residing in urban areas. There was no difference in the positive rates of SENV-D and SENV-H DNA among adolescents with or without hepatitis B virus (HBV) or hepatitis C virus (HCV) infection or history of hospitalization, surgery or blood transfusion. In multivariate analyses, males and adolescents residing in rural or mountainous areas had significantly higher risks of SENV-H viremia. As compared with those residing in urban areas, the multivariate-adjusted odds ratio (OR) for rural and mountainous areas were 1.49 (95% confidence interval [CI], 1.08-2.07) and 2.16 (95% CI, 1.32-3.53), respectively. CONCLUSION: SENV-D and SENV-H infection were frequent among adolescents in eastern Taiwan. SENV was unlikely to be transmitted via the parenteral route and factors associated with level of urbanization were probably the major determinants of SENV infection.

Geographic and ethnic variations of long-term efficacy and immunogenicity of hepatitis B vaccination in Hualien, a HBV hyperendemic area.

It is uncertain whether immunologic memory persists for 15 years or more after immunization and whether the efficacy of universal hepatitis B vaccination program (UHBVP) in socio-economically disadvantaged area with hyperendemicity of hepatitis B virus (HBV) infection is similar. We assayed hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs) on 2839 students aged 15 years or more born before (N = 248) and after (N = 2591) UHBVP. We found that students born after UHBVP had significantly lower positive rate of anti-HBs than those born before UHBVP (44.6% versus 75.0%, p<0.0001). Seropositive rate of HBsAg for students born after UHBVP was also declined significantly (1.9% versus 9.3%, p<0.0001). Preventive fraction of UHBVP on HBsAg-seropositivity was 78% (95% confidence interval, 0.64-0.87), which was at least 10% lower than previous studies. Preventive fraction in Han Chinese (74%) and Atayal (78%) students were lower than Amis students (94%). In 2264 Han Chinese students, preventive fraction was 16% lower in those resided in rural than urban areas. These observations indicated that UHBVP was less effective in socio-economically disadvantaged area where HBV infection was hyperendemic and the long-term efficacy and immunogenicity of vaccination were modified by host factors and factors associated with urbanization.