AIM: To investigate the regulatory function of bone marrow-derived mesenchymal stem cells (MSCs) on T helper 17 cells (Th17) and regulatory T cells (Treg) in peripheral blood of severe asthmatic children . METHODS:MSCs were isolated , cultured and identified in vitro.MSCs digested with mitomycin were cocultured with T lymphocytes (TLC) at different ratios (1∶1, 1∶2, 1∶10 and 1∶20) from severe asthmatic children for 72 h.The prolifera-tion of TLC was measured by CCK-8 method.In the coculture system of the 1∶2 ratio and the single TLC system , the super-natant levels of interleukin-17 (IL-17) and transforming growth factor-β(TGF-β) were measured by ELISA.The mRNA expression of retinoic acid-related orphan nuclear receptor C (RORC) and forkhead box protein 3 (Foxp3) in TLC was de-tected by qRT-PCR.RESULTS:After cocultured with MSCs , the proliferation of TLC decreased significantly in a dose-dependent manner (P<0.05).It also showed decreases in IL-17 (3 799 ±441 vs 4 890 ±373, P<0.05) and RORC mRNA level (1.21 ±0.14 vs 3.85 ±0.48, P<0.05), while an increase in TGF-βlevel (209 ±32 vs 117 ±26, P<0.05) was observed.No influence on the mRNA expression of Foxp3 was found (P>0.05).CONCLUSION: MSCs suppresses Th17 polarization of naive peripheral blood CD 4 +T cells and matures Th17 cells secreting IL-17, which may ef-fectively revise Th17/Treg imbalance of asthma .

Objective To investigate the potential diagnosis value of tumor signal enhancement rate (SER)combined with long-to-short axis ratio of breast lumps in axillary lymph node metastasis in patients with breast cancer by using dynamic contrast-enhanced MRI (DCE-MRI).Methods patients with primary breast cancers were enrolled in the study,MR examinations were performed before surgeries.SER features and long-to-short axis ratio of breast lumps were obtained.Receiver operating characteristic curves (ROC) were plotted to assess the diagnostic performance.Results When MR SER ≥180.5% and long-to-short axis ratio of breast lumps ≤0.56,the diagnostic performance of the combination in terms of AUC was the highest (AUC=0.826),in comparison with that of MR SER or long-to-short axis ratio of breast lumps alone.The associated sensitivity and specificity were 93.8% (60/64)and 88.7% (47/53),respectively.Conclusion The combination of MR SER and long-to-short axis ratio of breast lumps can further improve the ability to identify lymph node metastasis in patients with breast cancer in DCE-MRI,and provide a reference basis for clinical therapy and prognosis.