Objective:To determine the half lethal dose(LD50) of paraquat in rats and to establish a relatively safe and stable pathological animals model of pulmonary fibrosis.Methods: Ninety-six SD rats totally in half genders.Fifty SD rats in half genders were randomly divided into 5 groups,each had 10 rats.Feed the rats with different doses of liquor of paraquat intraperitoneally one time and definite the half lethal dose of one and two weeks.After that,prepare another forty-six SD rats,also in half genders,as intonication group,twenty-eight rats were treated with the liquor of paraquat in dosage of 18 mg/kg intraperitoneally.As control group,sixteen rats were treated with equivalent volume of normal saline.Observe the toxic symptom daily and rats were sacrificed on day 1,3,5,7,14,21,28,35 and 42 respectively for the histological examination.Results: The half lethal doses of intraperitoneal paraquat of 1 and 2 weeks were 18.27 and 17.29,with 95% confidence intervals of 16.61-20.09 and 15.99-18.67,respectively.After intraperitoneal paraquat injection at the dose of 18 mg/kg,typical toxic symptoms were observed at different times in the rats.The whole process of acute lung injury and fibrosis induced by paraquat intoxication could be seen with the naked eyes or under the light microscope.Conclusion: Paraquat has a strong toxicity to rats.A proper dose of paraquat solution can not only reduce the number of experimental rats,but also induce typical pulmonary fibrosis in rats.

Objective Using real-time fluorescence quantitative PCR to detect the gene expression of MMP-2,T1MP-1 in the rats' lung intoxicated by paraquat, and to discuss the effect of the MMP-2,T1MP-1 in the acute lung injury and pulmonary fibrosis afltr paraquat intoxication. Method Eighty Sprague-Dawley rats were randomly divided into control group and the intoxication group. The rats of the control group were given equivalent volume of normal saline, and the rats of the intoxication group were given a intraperitoneal injection of paraquat(18 mg/kg) . At 1,3,5,7,14 and 28 days after intoxication, the pathological changes were observed under the light microscope and the expression of MMP-2, TTMP-1 mRNA in the rats lung were detected by using real-time fluorescence quantitative PCR. Results Compared with the control group, in the early days after intoxication, the lung tissue of the intoxication group showed obvious inflammation, pulmonary edema and bleeding. Five daye after intoxication, pulmonary fibrosis could be ideatified and the fibrosis became obvious. At 28 days later the expression of MMP-2 mRNA was remarkably increased in lung tissue from the day of intoxication, and reached the peak 7 days later, It was control group, that in and then gradually, declined however, higher than that in control group (P < 0.01). The expression of TIMP-1 mRNA in lung tissue was also higher than the control group on the day 1, then increased gradually, reached the peak on day 14,7.28 times more than the control group, decreased from the fourteenth day,higher than the control group on day 28 (P < 0.01) . Conclusions MMP-2,TIMP-1 played a very important role in the acute lung injury induced by paraquat, meanwhile the development of pulmonary fibrosis had great relations on their disproportion.

Objective To explore the clinical characteristics and prognostic factors of primary gastric lymphoma.Methods Clinical data of 78 primary gastric lymphoma patients treated between September 2012 and January 2017 in our hospital were analyzed retrospectively.Results 1-year and 3-year survival rate were 86％ and 68％ respectively.Univariate analysis showed that the four factors including the level of serum lactate dehydrogenase (x2 =35.088,P =0.000),Musshoff stage (x2 =29.930,P =0.000),pathology types (x2 =6.077,P =0.014),IPI score (x2 =21.337,P =0.000) were associated with the prognosis.Multivariate analysis showed that Musshoff stage was an independent risk factor for the prognosis when stage Ⅰ,stage Ⅱ (OR =1.075,95％ CI:0.060-19.107,P =0.961) were compared with stageⅢ (OR =11.994,95％ CI:1.042-138.083,P =0.046),or stage Ⅳ (OR =13.165,95％ CI:1.476-117.417,P =0.021).Conclusions Musshoff stage is an independent factor for the prognosis,surgical treatment can not prolong survival and chemotherapy is the therapy of choice.