Objective To investigate the protective effect of carnosine on radiation-induced lung injury in mice.Methods A total of 108 C57/BL female mice were randomly divided into 4 groups:control group without treatment,irradiation alone group,irradiation + carnosine group (15 mg·kg-1·d-1),and carnosine alone group (15 mg· kg-1· d-1).There were 18 mice in control group and 30 mice in every other group.Whole lung anterior chest was irradiated with a single dose of 13 Gy 10 MV X-rays.The mice were administered with carnosine (15 mg· kg-1· d-1) at 30 minutes before irradiation and then garaged once a day until the end of the experiment.The control group was given with saline.At 7,28,and 56 d after irradiation,6 mice of control group and 10 mice of each other group were killed.A portion of lung tissues were stained with HE and other part of lung tissues were used to detect the levels of SOD.Meanwhile,TGF-β1 and TNF-α in the serum were detected with ELISA.Results Different levels of inflammation factors were expressed in the lung tissues of irradiation group and irradiation + carnosine group at 56 d after irradiation,but the inflammation in the irradiation + carnosine group was significantly lighter than that in the irradiation group.Among (7,28 and 56 d) after radiation,TGF-β1,TNF-α,and SOD levels in different groups had significant differences.At the same time point after irradiation,the level of SOD in lung tissue of irradiation + carnosine group was significantly higher than that of irradiation group (F =4.33,4.19,3.34,P ＜0.05),but the levels of TGF-β1 and TNF-α in serum were reduced.Conclusions Carnosine can prevent and inhibit radiation-induced lung injury in mice by increasing SOD and reducing TGF-β1 and TNF-α.

Objective:To compare the survival outcomes in patients of small cell lung cancer (SCLC) with brain-single metastasis and brain with organs-multiple metastasis.Methods:Using the US surveillance, epidemiology and final results database, 5 520 SCLC patients with complete clinical information from 2004 to 2015 were selected. SCLC patients were adjusted, stratified or matched according to the metastasis site after the stratification or matching of the propensity scores, and the lung cancer-specific survival (CSS) rate and overall survival (OS) rate were compared between brain-single metastasis group and brain with organs-multiple metastasis group. In addition, the effects of chemotherapy and radiotherapy in CSS between brain-single metastasis group and brain with organs-multiple metastasis group were compared.Results:Of the 5 520 SCLC patients, 2 658 cases was in the brain-single metastasis group, and 2 862 cases was in brain with organs-multiple metastasis group. After the stratification or matching of the propensity scores, the median survival time in brain-single metastasis group was significantly longer than that in brain with organs-multiple metastasis group (6 months vs. 4 months), and there was statistical difference ( P<0.05). The fatality rate in brain-single metastasis group was significantly lower than that in brain with organs-multiple metastasis group (80.66% vs. 85.96%), and there was statistical difference ( P<0.01). Kaplan-Meier survival curve analysis result showed that the OS rate and CSS rate in brain-single metastasis group were significantly higher than those in brain with organs-multiple metastasis group (14.72% vs. 9.50% and 19.34% vs. 14.04%), and there were statistical differences ( P<0.05). Cox analysis result showed that age, race, T stage, gender, N stage, radiotherapy, chemotherapy, tumor diameter, marriage and metastasis were the influencing factors of CSS rate in SCLC patients with brain metastasis ( P<0.01 or <0.05). Multivariate Logistic regression analysis result showed that radiotherapy and chemotherapy can significantly improve the CSS rate ( HR = 0.668 and 0.671, 95% CI 0.570 to 0.783 and 0.573 to 0.786, P < 0.01). Conclusions:The survival rate in SCLC patients with brain-single metastasis is higher than that of SCLC patients with brain with organs-multiple metastasis; chemotherapy and radiotherapy can improve the survival rate in SCLC patients with brain metastasis.