To monitor genetic variation of porcine reproductive and respiratory syndrome virus (PRRSV),RT-PCR was used to identify a sample suspected of PRRSV infection.A PRRSV named SC-GY strain was obtained,and its Nsp2,ORF5 and ORF3 genes were used for sequence alignment and phylogenetic tree construction.The results showed that SC-GY strain is highly pathogenic PRRSV American variant strains with Nsp2 gene discontinuous deletion of 30 amino acids,ORF3 gene aa17 a serine (S) insert.Comparing to VR2332,CH-1a,JXA1,HUN4,NADC30,HENAN-XINX and SC2012,the Nsp2,ORF5 and ORF3 of SC-GY shared 70.3％-97.9％,82.4％-97.6％ and 83.1％-98.2％ of nucleotide similarity,and 62.3％-96.3％,78.0％-95.7％ and 81.6％-96.5％ of deduced amino acid similarity;and compared to LV they shared only 18.9％,60.8％ and 63.7％ of nucleotide similarity,and 14.0％,54.9％ and 57.2％ of deduced amino acid similarity.The phylogenetic tree revealed that the SC-GY formed independent small branches although it belonged to the same subgroup as highly pathogenic PRRSV strains.The results showed that in high frequency live vaccine immunization of currently PRRSV,the gene of PRRSV epidemic strain is still in constant variation.Vaccination of live PRRSV vaccines should be reduced and surveillance of PRRSV strains should be enhanced.

Objective To investigate the Influence of Survivin and hTERT gene on cell proliferation and apoptosis in human colorectal carcinoma cell line SW 480 and to find experiment evidence for gene therapy of colorectal carci-noma .Methods Plasmids carrying shRNAs targeting survivin and hTERT were designed , constructed and trans-fected into SW480 cells.SW480 cells were then divided into blank group , blank Plasmid control group , survivin RNAi group , hTERT RNAi group and Survivin-hTERT RNAi group .The telomerase activity was examined by TRAP-PCR-ELISA analysis 48h after hTERT-shRNA transfection.Survivin and hTERT mRNA and protein expres-sion was analyzed by RT-PCR and Western blot .Cell apoptosis , proliferation were measured by flow cytometry , CCK-8 assay.Results Telomerase activity of SW480 cells in Survivin-hTERT RNAi groups were significantly decreased compared with the blank group ( P<0.01 ) .The expression of survivin and hTERT mRNA, proteins in the Survivin-hTERT RNAi group was reduced by 82.8%and 73.6%( P<0.01 ) ,79.2%and 66.7%( P<0.01 ) respectively .The inhibitory rate of cell proliferation of Survivin-hTERT RNAi group was 43.6% ±0.1%( P <0.01 ) .The apoptosis rate was 39.2%±2.3%( P<0.01 ) in the Survivin-hTERT RNAi group .Conclusions The Survivin-hTERT RNAi group could significantly reduces the protein expression of survivin and hTERT mRNA, in-hibit cell proliferation and induces cell apoptosis in human colorectal carcinoma cell line SW 480 .

Twelve compounds were isolated from the ethanol extract of Fructus Gleditsiae Abnormalis by macroporous resin, silica gel, Sephadex LH-20, MCI and ODS column chromatographies. Their structures were identified on the basis of physicochemical properties and spectral data as gleditsioside A(1), gleditsioside B(2), gleditsioside H(3), gleditsioside I(4), gleditsioside J(5), gleditsioside K(6), gleditsia saponins C′(7), tamarixetin-7-O-β-D-glucopyranoside(8), neohesperidin(9), chrysoeirol-7-O-neohesperidoside(10); syringaresinol- O-β-D-glucopyranoside(11), liriodendrin(12). Compounds 8-12 were firstly isolated from this genus.

Twelve compounds were isolated and purified from ethyl acetatefraction of Cynanchum stauntonii by silica gel, Sephadex LH-20 and ODS column chromatography. Their structures were identified by spectral techniques and physicochemical properties as syringaresinol(1), (-)-(7R, 7′R, 7″R, 8S, 8′S, 8″S)-4′, 4″-dihydroxy-3, 3′, 3″, 5-tetramethoxy-7, 9′ ∶7′, 9-diepoxy-4, 8″-oxy-8, 8′-sesquineolignan-7″, 9″-diol(2), prinsepiol(3), 4-hydroxyacetophenone(4), baishouwubenzophenone(5), 2, 4-dihydroxyacetophenone(6), benzoic acid(7), 1, 4-benzenediol(8), 6-O-［E］-sinapoyl-α-D-glucopyranoside(9a), 6-O-［E］-sinapoyl-β-D-glucopyranoside(9b), 1-O-methyl-α-D-cymadropyranoside(10), β-daucosterol(11), and β-sitosterol(12). Compounds 1-3, 5 and 7-11 were firstly isolated from this plant.

From the n-butanol extract of the leaves of Callicarpa nudiflora,thirteen compounds were isolated by repeated column chromatography with silica gel,C_(18) and Sephadex LH-20.Their structures were identified by spectroscopic (~1H,~(13)C NMR and so on) and chemical methods as luteolin (1),luteolin-7-O-β-D-glucopyran coside (2),apigenin (3),5,7,4'-trihydroxy-3'-methoxyflavone (4),luteolin-3'-O-β-D-glucopyranoside (5),api genin-7-O-β-D-glucopyranoside (6),luteolin-7-O-(6-trans-caffeoyl)-β-D-glucopyranoside (7),luteolin-7-O-(6-trans-feruloyl)-β-D-glucopyranoside (8),arjunglucoside I(9),luteolin-7-O-(6-p-coumaryl)-β-D-glucopyranoside (10),forsythoside B (11),isomartynoside (12),deacylisomartynoside B (13).Among them,compound 11 was isolated from this plant for the first time and compounds 4,7-10,12-13 were isolated from this genus for the first time.

Objective To explore the role and significance of matrix metalloproteinase-9 (MMP-9) in angiogenesis through observing the relationship between the expression of MMP-9 and microvessel density (MVD) in glioma. Methods The expressions of MMP-9 and CD34 in 10 cases of normal brain tissues and 58 cases of glioma (14 cases of grade Ⅰ , 20 cases of grade Ⅱ , 15 cases of grade Ⅲ, and 9 cases of grade Ⅳ ) were detected by immunohistochemical streptavidin-peroxidase technique. The positive cells of MMP-9 and the positive microvessels were examined under binocular light microscope. Results The positive expression of MMP-9 in glioma was located in the tumor-cell cytoplast and endothelial cells. The positive rate of MMP-9 in glioma of grade Ⅰ, Ⅱ, Ⅲ and Ⅳ was 42.9%, 65.0%, 86.7% and 88. 9%, respectively. The expression of MMP-9 was obviously higher than that of normal brain tissues (P<0.01) and positively correlated with glioma malignancy (rz =0. 597, P<0.05). MVD was correlated with glioma malignancy (H=47. 865, P<0. 05). The expression of MMP-9 was significantly correlated with MVD (rz =0.897, P<0.01). Conclusion The expressions of MMP-9 and MVD are correlated with glioma malignancy, which may be helpful in judging the malignancy, invasion and prognosis. MMP-9 plays an important role in angiogenesis of glioma and accelerates glioma malignancy development by promoting angiogenesis.

Objective Angiotensin Ⅱ (Ang Ⅱ ) contributes to modulating blood pressure by stimulation of Ang Ⅱ AT1 receptors. We devised a rat transient middle cerebral artery occlusion (MCAO) model to assess whether oxidative damage is decreased after pretreatment with Angiotensin Ⅱ AT1 receptor blocker (ARB). Methods After 2 weeks pretreatment with ARB 0. 5 and 1 mg/kg, the male Wister rats were subjected to 2 h middle cerebral artery occlusion (MCAO). At 24 h, the lumen diameter of middle cerebral artery, the plasma level of 8-hydroxy-2'-deoxyguanosine (8-OHdG), and HIF-1 a levels were recorded and compared. Results After pretrcatment with ARB 0.5 and 1 mg/kg, blood pressure did not significantly change compared with that of controls. In the group of candesartan at 1 mg/(kg· day), the lumen diameter was significantly increased compared to that in control group [(86.0±5.0) μm vs. (69.0± 2.1) μm; P<0. 01, n = 6- 8]. The plasma 8-OHdG levels of ARB pretreatment groups were decreased. In immunohistochemical findings, 8-OHdG- and HIF-1α-containing cells in ARB pretreatment groups were decreased. Conclusion Brain ischemia and oxidative damage can be reversed by AT1 receptor blockade in normotensive rats after transient cerebral artery occlusion.

Objective Angiotensin Ⅱ (Ang-Ⅱ) increases NADPH oxidase activity and stimulates the production of reactive oxygen species (ROS) including superoxide anion through Ang Ⅱ AT1-receptor (AT1-R) activation. ROS is involved in various pathological processes in brain ischemia. We investigated whether the AT1-R blocker (ARB) candesartan can protect normotensive rats against brain ischemia. Methods After 2-week pretreatment with candesartan, rats were subjected to 2 hours middle cerebral artery occlusion-reperfusion (MCAO-R) and 24 hours later, the infarct volume, iNOS, and eNOS mRNA in the internal carotid artery was recorded and compared. Results Candesartan pretreatment reduced cerebral ischemia and oxidative brain damage after MCAO-R in normotensive rats, resulting in a decreased cortical infarct volume [0.5 mg/kg candesartan, (46.8±13.2)mm3; 1.0 mg/kg candesartan, (19.3±15.3)mm3 vs. control, (111.7±14.3)mm3; P<0.05, P<0.01, respectively]. Candesartan pretreatment increased the eNOS mRNA level in the internal carotid artery. Conclusion In normotensive rats exposed to MCAO-R, candesartan protectes against brain ischemia. This effect may represent a significant therapeutic advantage and may induce end-organ protection even at normal blood pressure.

The animal experiment studies have demonstrated that hyperthermia is a strong teratogen to many kinds of animal with high incidence of neural tube defects(NTD).Epidermiological investigation showed that hyperthermia was closely related to the acencephaly and excenphaly in human being,but little was known about the distinct mechanism of NTD induced by hyperthermia.In order to study the developmental mechanism of NTD induced by hyperthermia,we observed the effects of hyperthermia on the neuroepithelial cells in primary culture.The neural tubes of the hamster embryos on 10 d after fertilization were obtained.the neuroepithelia were dissociated and then seeded at the density of 1×106 cells per well.The cells were divided into experimental and control groups randomly.The experimental groups were exposed to 42 C for 20 min,whereas groups exposed to 37 Cserved as control.After treatment of hyperthermia,the cells were incubated continuously at 37 C in a 95%air/5%CO2 humidified incubator,the culture was terminated after different intervals.Phase-contrast microscopy.scanning electron microscopy.transmission electron microscopy,MTT assay,agarose gel electrophoresis analysis,TUNEL detection,immunocytochemistryand image analysis were made.The results of the experimental groups indicated that the floating cells and apoptotic cells increased in number,the neurites of the cells were shortened even disappeared,the survival cells decreased in number,the ultrastructure of the cells demonstrated distinct abnormal changes,the function of mitochondria was impaired,the expressions of both bcl-2 and bax were abnormal.The above results suggest that hyperthermia may induce apoptosis of neuroepithelial cells,duringwhich bcl-2 and bax genes may play important regulatory roles.

Aim To construct the eukaryotic expression vectors of short hairpin RNA targeting survivin and observe its effect on biologic behavior of A549 cells and sensitivity of A549 cells to paclitaxel.Methods The DNA fragment targeting human survivin was inserted into the plasmid,and the recombinant plasmid was constructed.The recombinant plasmids cells were transfected into A549 cells by FuGENE transfection reagent.The expression levels of survivin gene were detected with RT-PCR and Western blot before and after transfection,respectively.Cell apoptosis was detected by TUNEL method.The sensitivity of A549 cells to paclitaxel was detected by MTT after transfection.Results The recombinant plasmid was successfully constructed.RNAi group cells showed lower expression of survivin than control group.The apoptosis rate of A549 cells increased after transfection.The IC50 of paclitaxel inhibiting A549 cells was 11.9 fold before transfection compared with those after transfection.There was significant difference between the two groups(P