Objective To investigate the biological effects of 12C heavy ions with different LETs,and to construct the dose-effect curves of chromosomal aberrations and micronucleus.Methods Human peripheral blood lymphocytes were irradiated with 0.5 - 5.0 Gy of 60Co γ-rays,29 and 148 keV/μm 12C with a dose rate of 0.5 Gy/min,respectively.The colchicine method and cytokinesis-blocking method were applied to measure chromosome aberrations and micronuclei formation,respectively. Results The chromosomal aberrations induced by 29 and 148 keV/μm of 12C ion had a linear dose response,while the dose-response of micronucleus induction followed to a linear-quadratic model.Chromosome aberration and micronucleus frequency increased with the LET of 12C ions. However, the micronucleus frequency increased slowly when the radiation doses exceeded 3.0 Gy..Chromosomal aberrations induced by 148 keV/μm 12C ions increased significantly when the time of colchicine treatment was prolonged.Conclusions Chromosome aberration and micronucleus induced by 12C ions increased with the LET,and the micronucleus frequency increased with dose less than 3 Gy.The biological effects of 12C ions were stronger than those of low LET irradiation of γ-rays.

Objective: To investigate adolescent haze weather health protection behavior, and to provide scientific basis for behavioral intervention and health guidance for adolescents in haze weather. Methods: From June 2015 to April 2016, 1 025 adolescents were selected from 22 classes in two middle schools of Baoding City, Hebei Province, by stratified cluster sampling method. General information questionnaire and the Brief Haze Weather Health Protection Behavior Assessment Scale Adolescent Version (BHWHPBAS AV) were used. Multiple linear regressions were conducted to explore factors affecting adolescent haze weather health protection behavior. Different models were used to confirm associations between influencing factors and BHWHPBAS AV scores. Results: Adolescents had a low overall score of BHWHPBASAV (45.81±13.16). The score rate of self adjustment after haze weather was the highest (64.54%). The score rate of obtaining relevant knowledge before haze weather was the lowest (50.28%). Compared with adolescents in urban area, rural adolescents had a lower BHWHPBAS AV score ( β=-3.20, P <0.01). Compared with students (living with parents), those living without parents had a lower BHWHPBAS AV score ( β=-4.16, P =0.01). Compared with students never receive physical examination,those had received physical examination during the past years had a higher BHWHPBAS AV score ( β=4.44，5.66，9.04, P <0.01). Compared with students with no knowledge of respiratory system diseases, those with moderate to sufficient knowledge had a higher BHWHPBAS AV score ( β=9.34，12.19，P <0.01). These associations were stable and consistent.Multiple linear regression analysis showed that residence, residence with parents, physical examination and knowledge of respiratory diseases were the relevant factors of BHWHPBAS AV score ( P <0.05). Conclusion Adolescent haze weather health protection behavior level is low and is affected by many factors. Cooperation should be strengthened to conduct behavioral interventions and health guidance on haze health protection for adolescents, so as to promote healthy growth of adolescents.

To explore the role of methotrexate (MTX) in regulating the number of regulatory T cells (Treg) and the mRNA expression of transcription factor Foxp3.
 Methods: 1) We analyzed the number of Treg and the mRNA expression of Foxp3 by flow cytometry (FCM) and quantitative real-time PCR (qRT-PCR) respectively in patients with psoriasis vulgaris, patients with psoriasis vulgaris after the 8-week treatment of MTX, and healthy people. 2) BALB/c female mice were smeared with imiquimod (IMQ) cream for 6 days. We recorded the change of the lesion in mice every day. The morphological changes of lesion in mice were evaluated by the psoriasis area and severity index (PASI) and HE staining. 3) The mouse model was randomly divided into a control group and an MTX group. The MTX group was treated with different doses of MTX (38.5 and 77.0 nmol/L) on the third day of this experiment. The morphological changes of lesion in mice were evaluated by PASI and HE staining. We tested the number of Treg and the expression level of Foxp3 mRNA in splenic lymphocytes.
 Results: 1) The number of Treg and the expression level of Foxp3 mRNA were lower in psoriasis vulgaris patients than those in the healthy control group (P<0.05). After 8-week treatment of MTX, the number of Treg was increased (P<0.05) and Foxp3 mRNA level was up-regulated (P<0.01). 2) Typical psoriasis-like skin lesions, such as red scaly skin plaque were found after topical application of IMQ. Both the number of Treg in the splenic lymphocytes of mice and the Foxp3 mRNA level of Treg were reduced by IMQ (P<0.01 and P<0.05). 3) Different doses of MTX for mice showed the ability to improve skin lesion, increase the number of Treg in the spleen of mice and Foxp3 mRNA level in psoriatic dermatitis of mice (P<0.05).
 Conclusion: MTX is able to regulate the number of Treg and Foxp3 mRNA expression in psoriasis.
Adjuvants, Immunologic ; pharmacology ; Aminoquinolines ; pharmacology ; Animals ; Case-Control Studies ; Female ; Forkhead Transcription Factors ; metabolism ; Humans ; Imiquimod ; Immunosuppressive Agents ; administration & dosage ; pharmacology ; Lymphocyte Count ; Methotrexate ; administration & dosage ; pharmacology ; Mice ; Mice, Inbred BALB C ; Psoriasis ; drug therapy ; immunology ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Random Allocation ; Spleen ; cytology ; T-Lymphocytes, Regulatory ; cytology ; drug effects ; metabolism