Objective The aim of the present study was to evaluate the performance of the simultaneous detection of HIV-1 RNA, HIV-1 DNA, and HCV RNA using one dried blood spot (DBS) as an alternative sample to plasma.Method A total of 571 paired DBS/plasma samples were collected from men who have sex with men (MSM) and injection drug users (IDUs), and serological and molecular assays were performed. Using plasma results as the reference standard, the performance of DBS tests for HIV-1 RNA, HIV-1 DNA, and HCV RNA was evaluated. Pearson’s correlation coefficients and Bland-Altman analysis were performed to assess the correlation and concordance between DBS and plasma.Results Among paired plasma/DBS samples with detectable HIV-1 RNA and HCV RNA, five samples (5/32) were not detectable in DBS, while measurable HIV-1 RNA levels were present in plasma (1.44 to 3.99 log10 copies/mL). There were two samples (2/94) with undetectable HCV RNA in DBS, while measurable HCV RNA levels were present in plasma (−5 to 5.99 log10 copies/mL). The correlation between HIV-1 RNA light chain variable region (VL) values obtained from plasma and DBS showed that r = 0.683 (P < 0.01), n = 27 and r = 0.612 (P < 0.01), n = 89 in HCV RNA. Bland-Altman analysis revealed that in HIV-1 RNA, the mean (± SD) difference between HIV-1 RNA in plasma and DBS was 1.00 ± 1.01 log10 copies/mL, and all samples were within ± 1.96 SD (−0.97 to 2.97 log10 copies/mL) for DBS. The mean difference (± SD) in HCV RNA was 0.15 ± 1.08 log10 copies/mL, and 94.38% (84/89) were within ± 1.96 SD (−1.96 to 2.67 log10 copies/mL). Overall, HIV-1 RNA and HCV RNA levels obtained from a DBS were lower than those obtained from plasma. HIV-1 DNA in a DBS showed concordant results with HIV-1 RNA in plasma. HIV-1 DNA RT-PCR using a DBS showed acceptable performance.Conclusion The performance of the simultaneous detection of HIV-1 RNA, HIV-1 DNA, and HCV RNA using one DBS was acceptable. DBS, as an alternative sample to plasma, may be a viable option for the simultaneous detection of HIV-1 RNA, HIV-1 DNA, and HCV RNA in resource-limited settings or for individuals living in areas that are difficult to access.
Objective Airborne microbial communities include a significant number of uncultured and poorly characterized bacteria. No effective method currently exists to evaluate the health risks of such complex bacterial populations, particularly for pneumonia.Methods We developed a method to evaluate risks from airborne microorganisms, guided by the principle that closer evolutionary relationships reflect similar biological characteristics, and thus used 16S rDNA sequences of 10 common pneumonia-related bacterial pathogens. We calculated a risk of breath-related (Rbr) index of airborne bacterial communities and verified effectiveness with artificial flora and a clinical project.Results We suggested applying Rbr80 to evaluate the health risks of airborne bacterial communities that comprise 80% of dominant operational taxonomic units (OTUs). The feasibility of Rbr80 was confirmed by artificial flora and by pneumonia data from a hospital. A high Rbr80 value indicated a high risk of pneumonia from airborne bacterial communities.ConclusionRbr80 is an effective index to evaluate the pneumonia-associated risk from airborne bacteria. Values of Rbr80 greater than 15.40 are considered high risk.
Objective This study aimed to use an air–liquid interface (ALI) exposure system to simulate the inhalation exposure of motorcycle exhaust particulates (MEPs) and then investigate the benchmark dose (BMD) of MEPs by evaluating cell relative viability (CRV) in lung epithelial BEAS-2B cells.Methods The MEPs dose was characterized by measuring the number concentration (NC), surface area concentration (SAC), and mass concentration (MC). BEAS-2B cells were exposed to MEPs at different concentrations via ALI and CRV was determined using Cell Counting Kit (CCK-8) assay. BMD software was applied to calculate BMD and the lower limit of benchmark dose (BMDL) according to Akaike Information Coefficient (AIC), with P-value based on Hill, Linear, Polynomial, and Power model.Results Our results reveal that BMD of NC and SAC were estimated by the best-fitting Hill model, while MC was estimated by Polynomial model. The BMDL for CRV following ALI exposure to MEPs were as follows: 364.2#/cm3 for NC; 0.662 × 107 nm2/cm3 for SAC; and 0.278 μg/m3 for MC.Conclusion These results indicate that MEPs exposure via ALI system induces a dose-dependent decrease of CRV and provides the potential exposure threshold of MEPs in a lung cell model.
Objective This study aimed to evaluate the association between occupational radiation exposure and changes in thyroid hormone levels among medical radiation workers.Methods This retrospective cohort study included 2,946 radiation workers from 20 Guangzhou hospitals. Data on general characteristics, participant radiation dosimetry, and thyroid function test results [thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroid hormone (T4)] were extracted from dosimetry and medical records. The generalized estimating equation was used to evaluate the trend of changes in thyroid hormone levels over time and was adjusted for age, gender, and occupation.Results The average annual effective dose was very low and showed a general downward trend. During the follow-up period, changes in T3 and T4 levels among radiation workers were –0.015 [95% confidence interval (CI) –0.018 to –0.012] nmol/L per year and –2.294 (95% CI –2.426 to –2.162) nmol/L per year, respectively. Thyroid hormone levels were significantly different between males and females. T3 levels in the group of upper quartile of dose were significantly higher than in the lower quartile group (P = 0.006). No significant decreased trend in thyroid hormone levels was observed with increasing average effective doses.Conclusion Thyroid hormone secretion might be affected even in low-dose radiation exposure environments.
Objective This study was designed to conduct a retrospective and systematic occupational health risk assessment (OHRA) of enterprises that used benzene, toluene, and xylene (BTX) in Shanghai, China.Methods All data for the study were obtained from 1,705 occupational health examination and evaluation reports from 2013 to 2017, and a semiquantitative model following Chinese OHRA guidelines (GBZ/T 298-2017) was applied for the assessment.Results The selected enterprises using BTX were mainly involved in manufacturing of products. Using the exposure level method, health risk levels associated with exposure to BTX were classified as medium, negligible, or low. However, the risk levels associated with benzene and toluene were significantly different according to job types, with gluers and inkers exhibiting greater health risks. For the same job type, the health risk levels assessed using the comprehensive index method were higher than those using the exposure level method.Conclusion Our OHRA reveals that workers who are exposed to BTX still face excessive health risk. Additionally, the risk level varied depending on job categories and exposure to specific chemicals. Therefore, additional control measures recommended by OHRA guidelines are essential to reduce worker exposure levels.
Objective To investigate reciprocal regulation between Fur and two RyhB homologs in Yersinia pestis (Y. pestis), as well as the roles of RyhBs in biofilm formation.Methods Regulatory relationships were assessed by a combination of colony morphology assay, primer extension, electrophoretic mobility shift assay and DNase I footprinting.Results Fur bound to the promoter-proximal DNA regions of ryhB1 and ryhB2 to repress their transcription, while both RyhB1 and RyhB2 repressed the expression of Fur at the post-transcriptional level. In addition, both RyhB1 and RyhB2 positively regulated Y. pestis biofilm exopolysaccharide (EPS) production and the expression of hmsHFRS and hmsT.Conclusion Fur and the two RyhB homologs exert negative reciprocal regulation, and RyhB homologs have a positive regulatory effect on biofilm formation in Y. pestis.