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Objective To observe the characteristics of hemorheologic changes of hyperlipidemia rats at an early stage and to explore the mechanism of myocardial ischemic injury.Methods Seventy-two SD rats which were fed with high cholesterol diet(cholesterol+lard+pig bile salt) to result in hyperlipidemia model fell into HC group.Thirty-six SD rats which were fed with common diet fell into control group.The rats were fed for 10 to 90 d.At an interval of 10 d,9 time points were set.Therefore the 2 groups were randomly divided into 9 subgroups.At each time point,the changes of plasma lipids,cTnI,hemorheologic parameters,and pathological change of the rats’ myocardium and coronary vessel were assayed.Results The main characteristic of our models was hypercholesterolemia and high low-density-lipoproteins(LDL).With the extension of feeding time,plasma viscosity of HC group increased significantly,and erythrocyte deformability decreased.After fed with cholesterol for 50 d,myocardial ischemic injury occurred in the HC group.Correlation analysis revealed that the incidence of myocardial ischemic injury in hyperlipidemia rats was closely related with hypercholesterolemia and high low-density-lipoproteins.Conclusion The abnormal change of hemorheologic characteristics of hypercholesterolemia is a cause of myocardial ischemic injury.
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Objective To detect the frequency of micronucleated polychromatic erythrocytes(fMNPCE) in mice bone marrow after irradiated with X-ray by flow cytometer(FCM) to study whether fMNPCE detecting method could become a rapid biodosimeter for early radiation damage. Methods BALB/c mice were randomly assigned to receive the X-ray irradiation at dose of 0.5,3.0,6.0 Gy(n=4 for each irradiation dose),and the bone marrow was collected in 6,12,24 h after irradiation.Another 4 mice were intraperitoneally injected with cyclophosphamide twice as positive control,of which the bone marrow was collected in 42 h after intoxication began and 4 treated with spurious radiation as normal control.Results fMNPCE in mice bone marrow increased remarkably in 24 h after exposure to 0.5 Gy X-ray(P
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Objective To investigate the effects of spindle poisons (Vincristine, VCR and Colchicine, COL) on the tk gene of mouse lymphoma cells. Methods L5178Y cells were treated with VCR and COL at different concentrations. Determination of cytotoxicity, cell inoculation efficiency, relative survival rate, relative suspension growth rate and mutation frequency was performed. Results The relative survival rate and suspension growth rate of L5178Y cells decreased significantly with the increasing doses of VCR and COL. The mutation frequency of tk gene induced by VCR (0.5～2.5 ng/ml) and COL(10～50 ng/ml) was 1～3 times higher than that of spontaneous mutation frequency of L5178Y cells. Conclusion VCR and COL have obvious cytotoxic and mutagenic effects on tk gene in L5178Y cells.
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Objective To investigate the preventive effect of soybean isoflacone genistein on rats with unilateral ureteral obstruction (UUO) and the related mechanisms. Methods Rats were randomly divided into the following groups: sham-operation (group S, n=18), UUO group (group C, n=30), and geinstein treatment group (group G, n=42, at the dose of 200 mg?kg -1 ?d -1 ). At 5, 10, 15, 20, 25, and 30 d after operation, the pathological changes of the ligated kidneys were observed and the expression of mRNA of TGF-? 1 in renal tissues was examined by RT-PCR. Results Genistein treatment significantly reduced the section percentage of interstitial fibrosis in ligated kidneys at different time after operation (P
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Objective To construct the small interfering RNA (siRNA) eukaryotic expression vector specific to human MGMT gene(pRNATin-H1.2/Neo MGMT siRNA) to observe its silencing effect on MGMT gene in vitro.Methods The pRNATin-H1.2/Neo MGMT siRNA expression vector was constructed by gene recombination,then transfected into the cultured HelaS3 cells.Inhibitory effect of siRNAs was detected by semi-quantitative RT-PCR.Results The pRNATin-H1.2/Neo MGMT siRNA expression vector was successfully constructed.Cells transfected with pRNATin-H1.2/Neo MGMT siRNA could obviously inhibit the expression level of MGMT gene.Conclusion The pRNATin-H1.2/Neo MGMT siRNA expression vector could inhibit the MGMT gene expression.
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<p><b>OBJECTIVE</b>To explore the molecular spectra and mechanism of human hypoxanthine guanine phosphoribosyl transferase (HPRT) gene mutation induced by ethyluitrosourea (ENU).</p><p><b>METHODS</b>Single cell cloning culture, two-way screening, multiple PCR amplification and electrophoresis technique were used.</p><p><b>RESULTS</b>With dose of ENU increasing, cell plating efficiency reduced (in the group with 100-200 micro g/ml doses, P < 0.01) and mutation frequency increased (in the group with 12.5-200.0 micro g/ml doses, P < 0.05) significantly. There was no all exons deletion in spontaneous mutations, and only 7.7% of them were detected as single exon deletion. But, deletion was found in 79.7% of ENU-induced mutations (62.5%-89.4%, P < 0.01), and deletion mutations in all nine exons of HPRT gene. Most of ENU-induced mutations were chain deletion with multiple exons (88.1%).</p><p><b>CONCLUSIONS</b>The spectra in spontaneous mutations differed completely from ENU-induced ones. ENU was liable to cause bigger changes in genetic structure, which suggested a stronger ENU's mutagenesis.</p>