Objective: To clone and express cDNA fragment of domains 1 and 3 of soluble VEGF receptor FLT-1 in E. coli and investigate effect of its recombinant protein on endothelial proliferattion and angiogenesis. Methods: Total RNA from the umbelical venous endothelial cells was obtained. From it, soluble FLT-1(sFLT-1) cDNA fragment of domians 1 and 3 was cloned and expressed in QIA expressionist. The recombinant protein was purified by chromatography and refolded. The methods of MTT and angiogenesis test of chick chorioallantoic membrance were used to determine bioactivities of sFLT-1 recombinant protein. Results: The expression system could express the sFLT-1 cDNA fragment with a low expression level. After purification and renaturation, the recombinant protein could specifically bind to 125 I-VEGF. 1 ?g recombinant protein sFLT-1 could suppress endothelial cell proliferation induced by 10 ng VEGF and angiogenesis of chick chorioallantoic membrance induced by 20 ng VEGF.Conclusions: sFLT-1 cDNA fragment can be expressed in QIAexpressionist. After being refolded, it can bind to VEGF and serve as an antagonist of VEGF.

Objective: To observe the inhibitory effect of gefitinib combined with DNA vaccine targeting EGFR against implanted Lewis tumors in mice.Methods: Chicken EGFR L2 domain and rabbit IgG Fc domain fusion pVAX1/cEGFR-rFc DNA vaccine was injected into mice and the titer of anti-EGFR in serum was determined by ELISA.The growth of Lewis cells was measured by MTT.Lewis lung cancer mouse models were established and were randomly divided into vaccine,gefitinib,gefitinib+vaccine,and control groups.The tumor volume and weight and survival of mice were examined in different groups.Results: The titer of anti-EGFR in mice vaccinated with pVAX1/cEGFR-rFc plasmid was 1∶1 000.The proliferation of Lewis cells in anti-EGFR combined with gefitinib was significantly inhibited compared with those in anti-EGFR and gefitinib groups(P

Objective: To clone cDNA encoding Ⅴ-Ⅶ extra-cellular domains of VEGF receptor KDR and investigate biological activity of the recombinant protein. Methods: Total RNA from the umbelical venous endothelial cells was obteined. From it, KDR cDNA was cloned into the BamH1 and Kpn 1 sites of pQE31 and made expressed with induction of IPTG. The recombinant protein was purified, refolded and determined for its biological activities. Results: The expression system could express the human recombinant extra-cellular protein of KDR with expression level accounting for 5% of the total bacterial protein. After renaturation, the recombinant protein could bind to 125 I-VEGF and suppress endothelial cell proliferation and angiogenesis of chick chorioallantoic membrance induced by VEGF. Conclusion: Human KDR extra-cellular domain can be expressed in E coli and after being refolded, has an action of binding to VEGF.

Objective To explore the clinical characteristics and prognosis of patients with malignant tumor of digestive system combined with venous thromboembolism(VTE).Methods The clinical data of 77 patients admitted in Beijing Hospital from January 2003 to April 2013 with digestive system malignant tumor complicated with VTE were retrospectively analyzed.The incidence,clinical features and prognosis of the patients with digestive system cancer were analyzed.Results Among 77 patients,57 cases of male and 20 cases of female were involved,with an average age of(68.7 ± 12.4)years,including 60 cases(77.9 ％)of adenocarcinoma.The pathological results showed that differentiated tumors accounted for 61.0％ (47/77).Among the 77 patients,pulmonary thromboembolism (PTE) accounted for 33.8 ％ (26 cases) and deep vein thrombosis(DVT)in the low extremities accounted for 66.2 ％ (51 cases).Among all the patients,the most common symptoms were dyspnea and swelling or pain in the extremities.The incidence of VTE was 24.7％ (19/77),13.0％(10/77),19.5％(15/77),5.2％(4/77),5.2％ (4/77),32.5％ (25/77) at 1,3,6,9,12,＞ 12 months after diagnosis of digestive system malignancies,respectively.By April 2013,the 54.5 ％ (42/77) patients died,among which 73.8 ％ (31/42) died of digestive system malignancies,11.9 ％ (5/42) died of PTE,14.3 ％ (6/42) died of other causes.The mortality rates at 1,3,6,9,12,＞ 12 months after the diagnosis of VTE were 20.8％ (16/77),6.5 ％ (5/77),13.0 ％ (10/77),5.2 ％ (4/77),2.6 ％ (2/77),6.5 ％ (5/77),respectively.The difference in VTE incidence between the group aged ≥65 years and group aged ＜65 years at 1,3,6,9 and 12 months after the diagnosis of tumors was not statistically significant(P =0.309).The differences in mortality(P =0.357) and in the median survival time(x2 =0.290,P =0.591) between the two groups were not statistically significant at 1,3,6,9 and 12 months after the diagnosis of VTE.Conclusions The risks for VTE are high in patients with digestive tract malignant tumor,advanced malignant tumor,poor histologic grade(poorly or moderately differentiation),and chemotherapy or surgery,which mostly occurs within 3-6 months after diagnosis.Most deaths occur within the 1st year after the diagnosis of VTE.

Objective To investigate clinical features and prognosis of patients with cancerrelated isolated distal deep vein thrombosis(IDDVT).Methods Data of 64 patients with malignant tumor complicated with IDDVT at our hospital from January 2003 to January 2013 were retrospectively analyzed for the clinical features and prognosis.Results Among the 64 patients,32 male and 32 female cases were involved,aged 37 to 87 years,average(66.0 ± 12.6) years.There were 42 cases aged 65 years and older and 22 cases aged under 65 years.The IDDVT involved veins of lower extremity in 64 patients,unilaterally (47/64)or bilaterally (17/64).The intermuscular veins were involved by IDDVT in 46 cases(71.9％).Posterior tibial veins were involved in 17 cases(26.6％),peroneal veins were involved in 14 cases(21.9％),anterior tibial veins were involved in 2 cases (3.1 ％).Common symptoms were swollen lower extremity and pain (53.1％).Bleeding occurred in 2 (3.6 ％) of the 55 patients(55/64,85.9 ％) who underwent anticoagulant therapy,and no major bleeding occurred.The cumulative incidence of IDDVT at 3,6,and 12 months after tumor diagnosis was 64.0％ (41/64 cases),75.0 ％ (48/64 cases) and 85.9 ％ (55/64 cases),respectively.The cumulative incidences of IDDVT at 3 and 6 months were higher after diagnosis of lung cancer than after diagnosis of digestive tract tumors(P =0.005 and 0.035).By the end of follow-up(a median follow-up of 13.0 months),30 patients(46.9 ％)died.The mortality rate was lower in the non-elderly group than in the elderly group (22.7％ vs.59.5％,x2 =7.850,P=0.005).The mortality rate was lower in patients with stage Ⅰ-Ⅲa than in patients with stage Ⅲb-Ⅳ(24.0％ vs.68.8％,x2=11.246,P=0.001).The mortality rate was lower in patients with gynecologic tumors(10.0％) than in patients with lung cancer(55.6％),digestive tract tumors (40.0％) and hematologic tumors (71.4％) (P =0.041,0.037 and 0.035,respectively).TNM Ⅲ b-Ⅳ (OR =8.42,95 ％ CI:1.93-30.00,P =0.004) and age ≥ 65 years (OR =6.28,95％CI:1.50-27.76,P=0.012)were independent risk factors for death.Conclusions Cancerassociated IDDVT most commonly involves the intermuscular veins.The incidence of hemorrhage after anticoagulant therapy is low.For patients without anticoagulation contraindications,active anticoagulant therapy should be recommended.The advanced cancer and old age are independent risk factors for cancer-related IDDVT death.