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991.
AIM: To research the characteristics of ventricular electrophysiology in right ventricular rapid pacing-induced congestive heart failure (CHF) dogs.METHODS: Dogs (n=16) were randomly divided into 2 groups: the control (n=7) and the CHF group (n=9) induced by rapid right ventricular pacing at 240 pulse·min-1 for 4 to 5 weeks.The electrophysiologic parameters were evaluated by the technique of standard electric stimulation and monophasic action potential (MAP) recording.RESULTS: (1) Ventricular effective refractory period (VERP),ventricular MAP duration (MAPD90),ventricular late repolarization duration (VLRD) and intra-ventricular conduction time (IVCT) were prolonged by 26% (P<0.01),43% (P<0.01),318% (P<0.05),and 19% (P<0.01),respectively in CHF group.(2)The ratio of VERP to MAPD90 (VERP/MAPD90) was decreased by 13% (P<0.05) in CHF group.(3) The dispersion of ventricular recovery time (VRT-D) was increased by 185% (P<0.01) in CHF group.(4) The ventricular fibrillation threshold (VFT) was decreased by 48% (P<0.01) in CHF group.CONCLUSION: The abnormal electrophysiological changes in the CHF condition may be contributing factors of lethal ventricular arrhythmias and sudden cardiac deaths in CHF. 相似文献
992.
AIM: To explore the effect and mechanism of preoperative transarterial chemoembolization on nephroblastoma.METHODS: Comparative analysis of clinical and pathological features in 39 children with Wilms’ tumor was conducted.TUNEL assay was used to detect the apoptosis of tumor in two groups with or without preoperative interventional treatment.The expressions of P53,Bcl-2 and Bax proteins were detected by immunochemical methods.The patients were followed-up for more than 2 years.RESULTS: The extent of neoplastic cell necrosis and degeneration,interstital fiber tissue hyperplasia of tumor and the number of infiltrating lymphocytes were observed,which were higher in interventional group than those in simple excision group (P<0.01).The median of mitotic index in tumor cells was 0.2 in interventional group,and 1.4 in simple excision group.The median of apoptotic index (AI) of the tumor cells was 25.9 in study group and 12.8 in control group (Uc=54.50,P<0.01),(Uc=117.00,P<0.05).The comparison between the means obtained in two groups revealed statistical difference (P<0.05).The expressions of P53 and Bcl-2 proteins were not correlated with apoptotic index,but the rate of expression of Bax protein (80.0%) in interventional group was higher than that (40.0%) in simple excision group.The two year event-free rate was 73.3% (11/15) in study group and 42.9% (6/14) in control group.CONCLUSION: Transarterial chemoembolization on nephroblastoma is effectively used to kill and inhibit tumor cell growth,as well as induce tumor cell apoptosis by Bax protein. 相似文献
993.
YUAN Qing-feng XU Li-hong CHEN Jia-ping ZHOU Wen CHEN Shu-jie SI Jian-min 《园艺学报》2007,23(11):2265-2267
AIM: To explore the effect of recombinant human epidermal growth factor (rhEGF) on the ERK1/2 pathway and its safety in use when the proliferation of cultured FL cells (human amnion epithelial cells) were promoted by rhEGF.METHODS: FL cells were stimulated by rhEGF at various concentrations.The proliferation rate of FL cells was evaluated by MTT assay.Western blotting was used to detect phosphorylation of ERK1/2 (p-ERK1/2) and the change of Bcl-2 and P53 protein.RESULTS: The proliferation rate FL cells reached the maximum when the concentration of rhEGF was 10 μg/L (42.4%,P<0.01).Western blotting showed that the activity of p-ERK1/2 increased significantly when rhEGF ranged in 10 μg/L to 60 μg/L.Level of Bcl-2 was unchanged in each groups.Level of P53 decreased significantly when the concentration of rhEGF was 60 μg/L.CONCLUSION: It is safe when rhEGF presents in optimization concentration of 10 μg/L.The capability of apoptosis may be depressed when rhEGF is in larger dose. 相似文献
994.
AIM: To analyze the nucleotide and putative amino acid sequences of PIA genes isolated from N.gonorrhoeae and to construct the prokaryotic expression system of PIA gene.METHODS: The entire PIA genes from 9 strains of N.gonorrhoeae were amplified by using high fidelity PCR.The target amplification fragments were sequenced after T-A cloning.Homology comparison of the nucleotide and putative amino acid sequences of PIA genes from the isolates with the reported sequences in GenBank was then performed.A prokaryotic expression system of PIA gene was constructed.Different dosages of IPTG were applied to induce the expression of the target recombinant protein (rPIA) and 10% SDS-PAGE plus Bio-Rad Agarose Image Analysor was used to determine the expression level of rPIA.rPIA was extracted using Ni-NTA affinity chromatography and the purified effect was detected by SDS-PAGE.RESULTS: In comparison with the reported PIA gene sequences (GenBank No: L19962),the homologies of nucleotide and putative amino acid sequences of PIA genes from the isolates were 99.6%-100% and 99.1%-100%,respectively,which indicated that all the isolates were belonging to serovars IA6.Output of rPIA was as high as 50.1% of the total bacterial proteins.The purified rPIA only showed a single target protein fragment in gel.CONCLUSION: Serovar IA6 is dominant in the local N.gonorrhoeae isolates and sequences of the encoding gene are relatively conserved.The constructed prokaryotic expression system is able to express rPIA with high efficiency,which may lay a foundation for further development of serological detection kit and vaccine of N.gonorrhoeae. 相似文献
995.
996.
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998.
对近20年来中国牡丹切花保鲜方面的最新研究进行了综述,以期为正在和将要从事牡丹切花保鲜研究的人们提供参考.我国的牡丹切花保鲜研究的对象多为中原牡丹品种群的品种,研究问题主要涉及乙烯、水分、保鲜剂等方面,关于分子水平上牡丹切花保鲜机理的研究未见报道.牡丹切花保鲜方面还有不少问题亟待开展或进行深入研究. 相似文献
999.
1000.
AIM: Through detecting bone marrow angiogenic mediators and inhibitors in aplastic anemia (AA) patients,the value of angionesis in AA pathogenesis was elucidated.METHODS: The patients were divided into severe AA group (SAA,8 patients),non severe AA group (NSAA,10 patients),and normal control group (7 persons),5 patients were observed before treating (group beginning) and getting improvement (group improving).The angiogenic mediators vascular endothelial growth factor (VEGF) and bFGF were detected by ELISA,angiogenic inhibitors IFN-γ and TSP were detected by ELISA and flow cytometry,respectively.RESULTS: The levels of VEGF were lower in SAA group and NSAA group than those in control group significantly (P<0.05),the levels of IFN-γ and TSP were higher than those in control group (P<0.05),especially in SAA group (P<0.01).Compared with group beginning,the level of VEGF was higher in group improving (P<0.05),the levels of IFN-γ,TSP were lower (P<0.05),there was no obviously difference between group beginning and group improving except IFN-γ.CONCLUSION: The dropping of angiogenic mediators and the rising of angiogenic inhibitors may be one reason of reducing the number of microvessel,which result in deficiency in supporting hemapoietic stem cells by bone marrow microenvironment. 相似文献