Objective To explore the effect of Cyclin A on origin recognition complex-1 (ORC1) expression of rat vascular smooth cells (VSMCs).Methods Primary VSMCs of thoracic aorta in rats was obtained by the adherence method of tissue culture.The synchrony of cell was obtained by the method of double-thymidine block.In different cell cycles of VSMCs,the expression of ORC1 mRNA was determined by RT-PCR and the protein expression of ORC1 was observed by flow cytometry.Results Synchronized VSMCs were obtained and identified by the methods of double-thymidine block,colchicine treatment and serum starvation.Synchronized growth was monitored by flow cytometry.All the synchronized VSMC's distribution ration was (89.22±3.54) ％ at G0/G1 phase,(66.74 ±7.16)％ at G1/S phase,(63.24 ±4.06)％ at S phase and (51.64 ± 11.18)％ at G2/M phase and there was statistically significant difference compared with other phase(P ＜0.01).There was no significant effect of Cyclin A on ORC1 mRNA expression at a quiescent stage of VSMC.At G2/M phase peaked ORC1 was (52.133 3 ± 2.122 1)％,at G1/S phase was(10.916 7 ± 0.531 1)％,at S phase was (7.656 7 ± 0.412 4)％,and there was statistically significant difference (P ＜0.01).At G2/M phase ORC1 downed to the lowest point was (1.276 7 ± 0.161 7) ％,at G1/S phase was (13.371 0 ± 1.057 3)％,at S phase was (3.043 3 ± 0.538 0)％,and there was statistically significant difference (P ＜ 0.01),suggesting that Cyclin A might prevent ORC1 binding the chromatin of VSMCs.Conclusion Cyclin A may be an important regulative factor at the initiation of ORC1 in VSMCs.

Objective To evaluate the diagnostic value of treadmill exercise test for coronary heart disease. Methods The results of coronary angiography, exercise treadmill test, and the main risk factors of 447 patients suspected of coronary heart disease were analyzed. Results Treadmill exercise test for coronary artery stenosis resulted in 90 3% sensitivity, 19 6% specificity, 65 1% positive predictive value, and 55 0% negative predictive value. Compared with patients with single vessel disease, lower, earlier, and longer lasting ST segment depression and less exercise burden for the maximum heart rate were found in those with multiple vessel disease. A total of 72 5% patients with coronary artery lesion (including coronary stenosis and coronary tunica intima lesion) had more than 2 risk factors. Conclusion Treadmill exercise test is a good non invasive method for screening of coronary heart disease: (1) negative result of treadmill exercise test can be used to exclude coronary heart disease, but positive result of treadmill exercise test plus more than 2 risk factors can predict the likelihood of coronary heart disease; (2) the treadmill exercise test can also reflect the degree and the range of coronary artery lesion.

Objective To explore the expression of origin recognition complex1(ORC1) during DNA replication progress of rat vascular muscle cells(VSMCs).Methods VSMCs of rat thoracic aorta were obtained by the adherence method of tissue culture.The growth curve was drawn by MTT.The association between DNA replication and the expression of ORC1 mRNA and protein in different growth phases of VSMCs was analyzed.Results The expression of ORC1 mRNA and protein in quiescence stage of VSMCs was not found.After stimulated with serum,the expression of ORC1 mRNA in rat VSMCs increased significantly,peaked at 12-24 h.The expression of ORC1 protein was similar to ORC1 mRNA in VSMCs.Meanwhile,the higher DNA replication of stimulated VSMCs was observed,peaked at 12-24 h after serum addition. Conclusion ORC1 may be involved in the DNA replication of rat VSMCs during the progress of proliferation.

Objective The processes responsible for the uptake of very low density lipoprotein(VLDL) by monocyte macrophage cells were investigated. Methods The effects of VLDL concentration, apoE ligand activity and scavenger receptor A (SRA) on the binding of 125 I VLDL to monocyte macrophages were analysed. The influence of VLDL on SRA mRNA and protein expression and VLDL receptor gene translation was probed. Results (1) The differentiated monocyte macrophages induced 125 I VLDL uptake by dose dependent pathway( r =0 71, P

0.05), and HC lead ECG was more useful than Wilson lead when applied to localize the right free wall and right-anteroseptal accessory pathway (P

Objective To investigate the effects of Irbesartan on endothelial function and autonomic nervous system activity of patients with essential hypertension. Methods The endothelium dependent flow mediated dilatation (F-MD) and the endothelium independent nitroglycerin mediated dilatation (NTG-MD) were evaluated by the brachial ultrasound examination. Time-domain indices of heart rate variability (HRV) were measured by 24 h ambulatory electrocardiogram. The changes of blood lipoproteins, blood glucose, insulin levels, endothelial function and heart rate variability in 60 patients with mild-moderate essential hypertension and 20 healthy controls were compared, and the effects of different antihypertensive agents (AT1 receptor blocker and diuretic) for 8-week treatment were observed. Results Endothelial dysfunction and abnormal autonomic nervous activity were observed in patients with mild-moderate essential hypertension as follow: mildly decreased total HRV and mildly increased 24-hour average heart rate, significantly decreased parasympathetic tone-rMSSD and PNN50, obviously lowered endothelium dependent F-MD. The postprandial insulin level and insulin/glucose ratio of patients with hypertension was significantly higher than that of healthy controls. The decreased blood pressure level caused by AT1 receptor blocker (Irbesartan) and diuretic (Indapamide) was similar. Irbesartan for 8-week therapy resulted in a significant improvement of the endothelium dependent F-MD and insulin resistence, the increase of vagal nervous activity and the decrease of 24-hour average heart rate, but Indapamide presented no such effects. Conclusion This study suggested that patients with mild-moderate essential hypertension have significantly abnormal endothelial function and autonomic nervous activity, and the beneficial effect of Irbesartan is associated with an improvement of insulin resistence and heart rate variability, not with the decrease of blood pressure level.

Objective To explore origin recognition complex 1(ORC1) expression in the rat vascular muscle cells at different phases of proliferation.Methods Vascular smooth muscle cells(VSMCs) of thoracic aorta of rats in primary culture were obtained by the adherence method of tissue culture.Total RNA of VSMCs was extracted.The expression of ORC1 mRNA of VSMCs at different phases of proliferation was determined by reverse transcription polymerase chain reaction(RT-PCR) and the expression of ORC1 protein by immunocytochemistry and laser confocal microscopy.Results Cultured VSMCs were confirmed by light microscope and immunocytochemistry.The expression of ORC1 mRNA in the quiescence stage of VSMCs was not found.After VSMCs were stimulated with serum,the level of ORC1mRNA had an obvious increase at 6 h,peaked at 12 to 24 h and decreased in the following 24 h.The expression of ORC1 protein was also not found in the quiescence stage of VSMCs,but the level of ORC1 protein during proliferation of VSMCs was significantly increased.Conclusion ORC1 may have an important role during the process of VSMCs proliferation in rats.

Objective To investigate the influence of RNA interference targeting ORC1 gene on the proliferation of rat vascular smooth muscle cells(VSMCss).Methods VSMCss were transfected with siRNA targeting ORC1 gene by liposome.The expression of ORC1 protein was detected by Western blotting.MTT test and ~(3)H thymidine~()(~(3)H-TdR) incorporation were used to detect VSMCss proliferation.The expression of proliferating cell nuclear antigen(PCNA) in VSMCss was detected by immunocytochemistry.Results After transfected of the three pairs of siRNA targeting ORC1 genes respectively,the expression of ORC1 was all lower than that in the control group(non-transfection and negative siRNA).Especially,that in the group transfected of the second pair positive siRNA decreased most significantly.The optical density of MTT,~(3)H thymidine incorporation and the expression of PCNA decreased significantly in VSMCss transfected with siRNA targeting ORC1 gene as compared with that in the control group.Conclusion ORC1 gene silenced by RNA interference can inhibit VSMCss proliferation.

Objective To investigate the influence of RNA interference targeting ORC1 gene on the phenotype of rat vascular smooth muscle cells (VSMCs). Methods VSMCs were transfected with siRNA targeting ORC1 gene by liposome. The expression of ORC1 protein was detected by Western blotting. The changes of phenotype-dependent markers was analyzed by flow cytometry. Results After transfected of siRNA targeting ORC1 genes, the expression of ORC1 was lower than that in the control groups (non-transfection and negative siRNA). ORC1 gene silencing increased the expression of VSMC contractile markers ?-SM actin and SM-2, and decreased the expression of synthetic marker osteopontin. ORC1 gene silencing greatly affected VSMC differentiated morphology. Conclusion ORC1 gene silenced by RNA interference can mediate the transition of VSMCs from synthetic phenotype to contractile phenotype.

Objective To investigate the efficacy and safety of radiofrequency catheter ablation for treating epicardial accessory pathway .Methods 8 patients with unsuccessful endocardial ablation of accessory pathway were mapped within coronary venous si-nus or middle cardiac vein and the radiofrequency catheter ablation was performed by the temperature control electrode .Results Ablation in 8 cases was successfully performed within coronary sinus or middle cardiac vein .There were no complications in all pa-tients .Conclusion Radiofrequency catheter ablation of epicardial accessory pathway within coronary sinus and middle cardiac vein is safe and effective .