Human umbilical cord mesenchymal stem cells (hUC‑MSCs) hold great potential in the search for therapies to treat refractory diseases, including rheumatoid arthritis (RA), due to their potential regenerative ability and extensive source. However, the role of hUC‑MSCs in vivo and the repair mechanisms for RA remain to be fully elucidated. The present study aimed to determine whether hUC‑MSCs exert immunomodulatory effects and have anti‑inflammatory capabilities in the treatment of embolisms. Following the transplantation of hUC‑MSCs into collagen type Ⅱ‑induced arthritic (CIA) model rats, magnetic resonance imaging (MRI) in vivo was performed, and the levels of interleukin (IL)‑1, IL‑17, tumor necrosis factor (TNF)‑α, vascular endothelial growth factor (VEGF), tissue factor (TF), CD4+CD25+ T cells (Treg) and antithrombin (AT) were measured. Bromodeoxyuridine staining was performed for histopathological examinations. As revealed by immunofluorescence and MRI experiments, the injected hUC‑MSCs preferentially migrated to the inflammatory joint sites of the rats. The Treg cell percentage and AT levels in the hUC‑MSC‑treated group were markedly increased, whereas the levels of IL‑1, IL‑17, TNF‑α, VEGF and TF were decreased compared with those in the CIA model group. The values determined for these parameters in the hUC‑MSC‑treated group returned to approximately the identical values as those of the control group on day 35 post‑therapy. Superparamagnetic iron oxide nanoparticles (SPIONs) may serve as an effective, non‑invasive method for tracking transplanted cells in vivo. The present study provided direct evidence that hUC‑MSCs in the CIA rat model migrated to the inflammatory joint sites, effectively promoting recovery from collagen type II damage and thereby improving the immune‑associated prothrombotic state.

ObjectiveTo explore the physical and mental health problems of front-line healthcare workers fighting COVID-19 across the three phases of the epidemic rescue mission (before, during and after) in China.DesignA qualitative study was adopted using face to face, in-depth semistructured interviews. Phenomenological research methods and Colaizzi’s seven-step analysis method were used in the study.SettingThe setting of the study was the offices of healthcare workers in 12 tertiary hospitals.ParticipantsThirty-one front-line healthcare workers from 16 provinces in China, who carried out rescue missions in Hubei Province, were interviewed from October to November 2020.ResultsPhysical and mental health problems existed before, during and after the COVID-19 rescue mission. Eleven themes emerged during the three phases. Two themes appeared before rescue mission: basic diseases, anxiety before rescue mission. Five themes appeared during rescue mission: basic physical function disorder, physical exhaustion, negative cognition, negative emotions and negative behaviour. Four themes appeared after rescue mission: physical dysfunction, negative emotions, stigmatisation and hypochondriasis.ConclusionBoth physical and mental health problems occurred throughout the three phases. The study results pointed that a comprehensive prevention and control system that addresses both physical and mental health problems of front-line healthcare workers throughout the three phases of epidemic rescue mission (before, during and after), and that involves themselves, their families, hospitals, the government and social organisations is needed.

Background: Many studies have analyzed the association between traffic-related air pollution and risk of childhood leukemia, but the results are inconsistent. Therefore, we performed this meta-analysis to investigate the association between traffic-related air pollution and risk of childhood leukemia. Methods: PubMed, Cochrane, and Embase databases were searched by the index words to identify eligible case-control studies, and relevant literature sources were also searched. The latest research was performed in September 2017. Odds ratio (OR) along with 95% confidence interval (95% CI) were used to analyzed the main outcomes. Results: Twenty-one case-control studies were included in the meta-analysis. The results indicated that in the studies of overall traffic density (OR: 1.01, 95% CI: 0.98-1.04), high traffic density (OR: 1.04, 95% CI: 0.91-1.17), moderate exposure to NO2 (OR: 1.02, 95% CI: 0.93-1.10), and benzene (OR: 1.04, 95% CI: 0.71-1.37), the risks of childhood leukemia incidence were higher in the case group than the control group, but no significant difference was found. In other analysis, no significant difference was observed in the risk of childhood leukemia in the 2 groups. Conclusions: Current evidence suggests that childhood leukemia is associated with traffic density, and moderate exposure to NO2 and benzene. However, more high-quality studies are required to confirm the conclusions.

The aim of the current study was to explore delayed retirement intention and its influencing factors in a large sample of older Chinese workers. A cross‐sectional questionnaire survey was conducted among a convenience sample of 2776 older Chinese workers. Multinomial logistic regression analyses were performed separately for male and female workers to examine the association between work characteristics, family factors, personal health and the neuroticism trait and delayed retirement intention. Results showed that workers had low delayed retirement intention, while female workers were more reluctant to delay retirement than male workers. Job demand‐control, job satisfaction, family economic status, family caregiving responsibilities, chronic diseases, physical health, mental health and neuroticism were predictors of male workers' delayed retirement intention, while job effort‐reward imbalance, job satisfaction, family caregiving responsibilities and neuroticism were predictors of female workers' delayed retirement intention after controlling for demographic factors.