ObjectiveTo evaluate therapeutic effect and the possible mechanism of smecta on paraqual plasma concentrations and multiorgans injury induced by paraquat intoxication in rats. Methods A total of 76 healthy adult SD rats were randomly ( random number) divided into group A (control group n =6),group B ( poisoned group n =30 ),group C (smecta-treated group n=30).Rats in groups B and C were treated intragastrically with PQ at 50 mg/kg,the rats in the group C were given with smecta at 50 mg/kg,while the rats in the other two groups were only intragastrically adminstered with saline.Live rats in groups B and C were sacrificed at 2,6,24,48,72 h after administration of PQ for the determination of paraquat plasma concentrations and for HE staining of lung,stomach and jejunum.The rats were executed at the end of trial by the same way in group A.All measurement data were expressed as means + standard deviation ((x) ±s).The data of pathological score were compared with Independent-samples T test and the data of PQ concentration compared with analysis of variance (ANOVA) followed by LSD-t multiple comparison test.P-values of less than 0.05 were considered statistically significant.ResultsThe paraquat plasma concentration ( ng/ml ) was 440.314 ± 49.776 to 4320.6150 ± 413.947.There were different pathological changes of lung,stomach and jejunum in group B. Lung injuries gradually deteriorated,congestion,edema,leukocyte infiltration,incrassated septa and lung consolidation were observed.The pathological changes were obvious such as abruption of mucosa,hyperemic gastric mucosa and leukocyte infiltration in stomach.Haemorrhage of jejunum mucosa,abruption of villus,gland damage and inflammatory cell infiltration were found. Compared with group B,all the pathological changes mentioned above were obviously alleviated in group C ( P ＜ 0.05 ),and the concentrations reduced ( P ＜ 0.01 ).Conclusions Smecta reduced paraquat plasma concentrations and alleviated pathologic injury of rats with PQ poisoning.

Objective:To investigate the serum levels, diagnosis and prognosis value of endothelin-1(ET-1) in children suffering from lung metastasis of osteosarcoma.Methods:A total of 84 children with osteosarcoma, 67 children with lung metastasis of osteosarcoma and 35 healthy people from January 1, 2013 to January 1, 2018 in Second People′s Hospital of Nanyang were retrospectively included.The serum level of ET-1 was measured by performing enzyme linked immunosorbent assay(ELISA) methods and the influencing factors of serum ET-1 levels in children with lung metastasis of osteosarcoma were conducted by Logistic regression analysis.The clinical value of ET-1 in the prediction of the incidence of lung metastasis in children with osteosarcoma was analyzed by receiver operating characteristic (ROC) curve.Forty-five children with lung metastasis of osteosarcoma were followed up for 18 months and the prognosis value of serum ET-1 levels in children with lung metastasis of osteosarcoma was evaluated by Kaplan-Meier survival analysis. Results:The serum ET-1 level in children with lung metastasis of osteosarcoma was 97.23 (65.13, 134.98) ng/L and significantly higher than osteosarcoma group 60.21 (43.12, 74.63) ng/L and healthy control group 34.45 (12.01, 63.03) ng/L, respectively ( Z=-5.671, -4.92, all P<0.05), with significant differences. Logistic regression analysis proved that lung bilateral involvement ( OR=3.449), numbers of lung metastases (more than 3)( OR=3.449), average diameter of lung metastases (more than 5 cm) ( OR=6.501) and extrapulmonary metastasis ( OR=4.369) were independent risk factors for elevated serum ET-1 levels in children developing lung metastasis of osteosarcoma.The predictive value of ET-1 in the incidence of lung metastasis in children with osteosarcoma was significant (area under ROC curve: 0.841). When the cut-off value was 94.27 ng/L, the sensitivity and specificity were 88.5% and 92.6%, respectively.Survival analysis revealed that higher levels of ET-1 was correlated with poor prognosis ( OR=3.287, 95% CI: 1.119-9.547). Conclusions:The serum levels of ET-1 in children with lung metastasis of osteosarcoma are significantly elevated.ET-1 is a serological marker for the differential diagnosis of lung metastasis of osteosarcoma.Moreover, the higher levels of ET-1 are correlated with poor prognosis in children with lung metastasis of osteosarcoma.