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991.
AIM: To look for harmfulless anti-leukemia drug with selective high performance, lethal effect of small hairpin RNA (shRNA) on VEGFR2 gene expression of tumor cell line HL60 in vitro.METHODS: The most effective VEGFR2 siRNA was designed and screened. The shRNA oligo was designed and pU6/VEGFR2 entry clone was constructed. HL60 was transfected transiently and vascular endothelial growth factor receptor 2(VEGFR2) expression was tested with MTT assay, RT-PCR and Western blotting. The expression clone was constructed and cotransfected with ViraPowerTM Packaging Mix into 293FTTM cells to produce Lentiviral vectors harboring Lenti6/shVEGFR2. The virion supernatant was added into HL60 cells and VEGFR2 gene inhibitory effect was determined. RESULTS: The inhibitory rates of VEGFR2 siRNA c were high. VEGFR2 expression in HL60 was inhibited by using pU6/VEGFR2 entry clone constructed with shRNA and pENTRTM/U6. For HL60 cells, the inhibitory rate was 84.9%. The expression of VEGFR2 mRNA and protein decreased significantly. 48 hours after transfection of pU6/shVEGFR2 entry clone and transduction of Lenti6/shVEGFR2 expression clone, the cell inhibitory rates were similar. Cell growth inhibitory rate of entry clone descended rapidly after this time point, the expression clone changed slowly, reaching the peak at 96 hours, dropped slightly, having no significance deviation. CONCLUSION: in vitro, VEGFR2 shRNA using lentiviral vector blocks VEGF/VEGFR2 self-secretion in HL60 cells, which inhibits leukemia development.  相似文献   
992.
AIM: To explore the effect of the pretreatment of hypertonic saline (HTS) in hepatic ischemia reperfusion (I/R) injury.METHODS: The rats were divided into sham group (sham group), ischemia reperfusion group (IR group) and pretreatment of hypertonic saline group (HTS group). Partial hepatic ischemia reperfusion model was used. The rats were sacrificed at the time of 1 h, 3 h, 6 h, 12 h and 24 h after reperfusion in each group, respectively. Blood samples were obtained to examine ALT. The expression of the CD11b/CD18 (Mac-1) on the neutrophils was analyzed by flow cytometry. RT-PCR and Western blotting were used to examine the expression of intercellular adhesion molecule-1 (ICAM-1) in livers and chromatometry was performed to detect the activity of myeloperoxidase (MPO) in livers. The morphology of hepatocytes and the structure of sinusoid were observed by histological examinations. RESULTS: ① HTS pretreatment decreased the level of ALT at the time points of 3 h, 6 h and 12 h after reperfusion (P<0.05). ② Mac-1 expression in HTS group was lower at 6 h and 12 h after reperfusion compared with IR group (P<0.05). ③ MPO activity in HTS group was lower at 6 h, 12 h and 24 h compared with IR group (P<0.05). ④ RT-PCR and Western blotting analysis indicated that the pretreatment of HTS inhibited the expression of ICAM-1 in livers after reperfusion. ⑤ Moderate hepatocyte swelling and few neutrophil infiltration were observed in HTS group.CONCLUSION: Pretreatment with HTS has the effect on hepatic ischemia reperfusion injury by inhibiting the expression of Mac-1 on circulating neutrophils and the expression of ICAM-1 in the liver.  相似文献   
993.
994.
995.
AIM:To investigate the possible mechanism of deferoxamine on angiogenesis in rat hypoxic-ischemic encephalopathy (HIE). METHODS:SD rats (7 days of age) were used to make HIE model. Model group and treatment group were injected with deferoxamine or normal saline alone 24 hours before hypoxic-ischemic insult. Rats were sacrificed at 1,3,7 or 14 days after hypoxic-ischemic insult. Brain capillary density index (BCDI),the number of proliferating capillary,brain water content and extent of brain atrophy were determined. The expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α(HIF-1α) mRNA was measured. RESULTS:Early water content and late atrophic ratio of the left brain were significantly improved in the treatment group compared to model group (P<0.01). The number of proliferating capillary in the treatment group was significantly higher than that in the model group [(2.01±0.31)/HPF vs (0.90±0.25)/HPF,P<0.01]. Deferoxamine markedly up-regulated the expression of VEGF and HIF-1α mRNA in the brain [VEGF at 12 h: (1.41±0.07) vs (1.10±.15),P<0.05; HIF-1α at 12 h: (1.49±0.12) vs (1.11±0.16),P<0.05].CONCLUSION:Deferoxamine may promote angiogenesis and attenuate hypoxic-ischemic induced brain injury via up-regulation of HIF-1α and VEGF expression.  相似文献   
996.
AIM: To investigate the effect of 188Re labeled monoclonal antibody on prostatic specific membrane antigen 7E11C5.3,radioimmunotherapy for the treatment of human prostate cancer cell line LNCaP in vitro.METHODS: 188Re-7E11C5.3 was prepared by direct 2-mercaptoethanol reduction method.Labeling efficiency and radiochemical purity was measured by paper chromatography.Immunoreactive fraction was determined by linear extrapolation.Cytotoxicity to LNCaP cells was determined by MTT assay.RESULTS: The labeling yield of 188Re-7E11C5.3 was (93.16±2.18)%,the radiochemical purity was (95.62±0.48)%,and the immunoreactive fraction was (74.86±1.86)%.The inhibitory effect of 188Re-7E11C5.3 on cell proliferation of LNCaP cells was significantly higher than that of 188Re-mIgG or 188ReO-4.The 50% inhibitory doses (IC50) of 188Re-7E11C5.3,188Re-mIgG,and 188ReO-4 were (23.38±3.73)×107 Bq/L,(59.21±8.02)×107 Bq/L and (68.89±10.91)×107 Bq/L,respectively.CONCLUSION: 188Re-7E11C5.3 can effectively inhibit the growth of in vitro cultured prostate cancer cells and shows much potential for prostate cancer radioimmunotherapy.  相似文献   
997.
998.
以Navier-Stokes方程为模型基础,运用ANSYS/FLOTRAN软件对华北型机械通风式连栋塑料温室在不同山墙门打开度情况下室内的气流场进行三维稳态模拟.同时通过试验测得温室内各测点的气流流速,并分析试验数据得到温室内的气流流速的平均值.结果表明:在试验条件下山墙门打开度为2.3×2 m2,造成室内局部风速过大,流场分布紊乱;山墙门打开度为2.3×3m2,使室内风速平均值太小,达不到温室通风的要求;山墙门打开度为2.3×2.4m2时在同等条件下温室内的气流场分布均匀,平均风速最大,通风效果较理想.  相似文献   
999.
以主栽品种紫花杧为试材,探讨不同果袋类型的套袋效果.结果表明:套袋可大幅度降低采收果的果面流胶和雨水污染,极显著地降低果面虫伤率.套袋可改变采收时的果面颜色,但不同果袋类型间存在差异.后熟完成时,果面均为品种固有颜色,不因果袋种类而改变.套袋能促进果实后熟转黄和果色均匀,能显著降低炭疽病的病果率,但不同果袋对蒂腐病的防效存在较大差异.套袋能提高可溶性固形物含量和减轻果实失重.供试品种用外黄内黑复合纸袋套袋效果最为理想.  相似文献   
1000.
AIM: The aim of this study was to examine the microstatellite instability (MSI) and loss of heterozygosity(LOH) of locus D17S396 on chromosome 17 and their influence on the expression of nm23H1 in hepatocellular carcinoma (HCC),which may provide experimental evidence for the mechanism of nm23H1 gene and tumor metastasis.METHODS: Techniques such as DNA extraction from formalin-fixed paraffin-embedded tissues,PCR-SSCP,ordinary silver stain were used to study MSI and LOH of locus D17S396.Envision immunohistochemistry and Leica-Qwin computer imaging techniques were used to assess the expression of nm23H1.RESULTS: ① The frequency of heredity instability of HCCs was 35.42%.The frequency of LOH in the cases with lymph node or distant organs metastasis or not and with intrahepatic metastasis or embolus of portal vein or not was significantly different (P<0.01),it was higher in stage TNM Ⅲ than that in stageⅠ and Ⅱ.Moreover,it was higher in high tendency to invasion or metastasis cases than that in the low tendency cases (P<0.01).② The expression of nm23H1 was 56.25%.It was significantly different in Edmondson grade,TNM stage and in lymph node or distant organ metastasis cases (P<0.01).The cases with high tendency of invasion or metastasis exhibited lower nm23H1 expression compared with low tendency cases (P<0.01).③ The positive rate of nm23H1 protein in LOH positive group was lower than that in LOH negative group (P<0.05).CONCLUSION: The results indicate that both MSI and LOH of nm23H1 gene control the development of HCC independently in different pathways.LOH inhibits the expression of nm23H1,which endows it with high aggressive and poor prognosis.Increase in the amount of nm23H1 protein expression effectively restrains the tendency to invasion or metastasis of HCCs and improves prognosis of patients.  相似文献   
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