BACKGROUND: The method of culture purified sinoatrial node cell is important in investigating its ultrastructural characteristics and autorhythmic mechanisms.However,the corresponding method has not been standardized.OBJECTIVE: To summarize the localization,cultivation and purification of sinoatrial nodes isolated from newborn rabbits,and to study the morphological characters of primary cultured pacemaker cells.METHODS: Hearts of the newborn rabbits(within 24 hours)were embedded in paraffin for hematoxylin-eosin staining,The location of sinoatrial nodes was observed under an optical microscope,the morphology of sinoatrial nodes cells were observed by light microscope and electron microscope.RESULTS AND CONCLUSION: Sinoatrial nodes localized in the anterior wall of the superior vena cava and the posterior laterial wall of right atrium.There was about 0.32 mm between its lowest point and sulcus terminalis.Three distinct types of cells were observed among the cultured cells of sinoatrial nodes: spindle,spider and polygon.The spindle cells occupied the greatest proportion of the cultured cells(59.6±7.3)%.The spontaneous contraction frequency of spindle cells was the highest among the constracting cells(145±9)times per minute.The ultrastructure observation showed that myofibrils and other organelles in spindle cells were sparse and significantly decreased in number compared with triangle cells.There was no significant difference between triangle cells isolated from sinoatrial nodes and from atrial muscle.Sinoatrial nodes could be harvested along the anterior root of the superior vena cava down to the posterolateral sulcus.Among the cultured cells from neonatal rabbit sinoatrial nodes,the spindle cells with small body and fast pulse frequency are pacemaker cells.

Objective To study the protective effects of propofol pretreatment on ischemia-reperfusion injury in rabbit heart. Methods Forty New Zealand white rabbits (40 male, weighting 2. 5 ± 0. 36kg) were randomly assigned to 4 groups, including sham operation group, ischemia reperfusion (IR)group, IR + ischemia preconditioning (IP) group and IR + Propofol preconditioning (PP) group (n =10 each). The myocardial ischemia-reperfusion model of rabbits was established by coronary artery ligation.The levels of high energy phosphates (ATP, ADP and AMP) in myocardial tissue were measured by HPLC.The activities of serum lactate dehydrogenase (LDH), serum creatine kinase-MB (CK-MB) superoxide dismutase (SOD) and malondiadehyd (MDA) in myocardial tissue were assayed. Results The content of ATP, ADP, AMP, and the activity of SOD in PP group and IP group were higher than that of IR group, and the content of LDH, MDA and CK-MB in injured myocardial tissue in PP group and IP group were obviously lower than that of IR group (P ＜0. 05, P ＜0. 01). No difference was found in PP group and IP group(P＞0. 05). Conclusion Propofol preconditioning as well as ischemia preconditioning protected the myocardial tissues from the ischemia-reperfusion injury by improving the myocardial energy metabolism, the debasement of the oxyradical level and the antagonism the reaction of lipid peroxides.

Objective To investigate the effect of selective intracoronary stenting to the improvement of myocardial viability and left ventricular function aftcr Q-ware acute myocardial infarction. Methods 32 patients with initial Q-wave myocardial infarction underwent isoket-infusion 99Tc mMIBI SPECT imaging and blood pool radionuclide ventriculography before and after selective intracoronary Stenting. Results (1) The abnormal radioactive segments were 212 vs 108 before and after intracoronary stenting. The mean scores of abnormal segments were 16.1?3.9 vs 8.3?1.4 (P

Objective To evaluate and compare the therapetic effectiveness among intravenous rt-PA thrombolysis, thrombolysis plus delayed intracoronary stenting and delayed intracoronary stenting for acute myocardial infarction (AMI) using 99 [KG*2/3]Tcm-MIBI myocardial SPECT imaging. Methods Ninty-five cases of AMI were divided into three groups which were the thrombolysis group (n=31), thrombolysis plus delayed stenting group (n=30) and the delayed stenting group (n=34). 99 [KG*2/3]Tcm-MIBI myocardial SPECT imaging was performed 3 weeks after thrombolysis therapy or 1 week after intracoronary stenting.The left ventricular myocardium was divided into 16 segments for evaluation. The score of myocardial 99 [KG*2/3]Tcm-MIBI uptake were analyzed semiquantitatively and the total score of myocardial 99 [KG*2/3]Tcm-MIBI uptake was calculated. Results The scores of the 3 groups were 28.4?7.5, 19.4?6.2 and 27.3?7.2 respectively. Significant difference was shown in the thrombolysis plus delayed stenting group compared with the thrombolysis and the delayed stenting group (t=7.2, t=6.9, P0.05). Conclusion 99 Tcm-MIBI myocardial SPECT imaging has been proved to be an objective parameter for evaluating the therapeutic effectiveness of the various treatments of AMI. Thrombolysis plus delayed stenting seems to be more effective than thrombolysis and delayed stenting. On the other hand, thrombolysis and delayed stenting show similar effect in the treatment of AMI in the study.

Objective To study lentinan’s promotion on XELOX regimen’s curative effects on advanced gastric cancer. Method Cases with advanced gastric cancer were divided into observation group and control group according their therapy method. The curative effects, side effects, WBC, lymphocyte subsets, NK cells and quality of life were compared. Results The difference of disease control rates in two groups were not significant (P=0.091). The incidences of side effects in observation group were significantlly lower than in control group (P<0.05). The observation group’s WBC, Lym, CD 3+, CD 4+, CD 8+, NK cells and quality of life were significantly higher than in control group(P<0.05). Conclusion Lentinan could significantly promote gastric cancer patients’immunity and lessen side effects. It can promote XELOX regimen’s curative effects on gastric cancer and improve quality of life.

To observe the protective e ect of oral Liuweidihuang pill combined with Shengmai capsule on heart of primary hypertension with syndrome of de ciency of both qi and yin of heart and kidney.Method:While decreasing blood pressure with Captopril,oral Liuweidihuang pill combined with Shengmai capsule was used to treat 55 cases of primary hypertension,control groups was established.BP,cardiac function,damage degree of myocardial hypertrophy and blood vessel endothelium were detected.Result:ALL the indexes above in treatment group decreased obviously,showed signi cant di erence when compared with control group.Conclusion:Oral Liuweidihuang pill combined with Shengmai capsule and Captopril has cooperative e ect of antihypertension.The combined medication can treat heart damage by reducing myocardial oxygen consumption index,reversing myocardial hypertrophy,improving left ventricular function,protecting blood vessel endothelium,and preventing arteriosclerosis.

BACKGROUND: Studies have demonstrated that hyperpolarization-activated andcyclic nucleotide-gated cation channels (HCN) 2 and HCN4 are abnormal expressed in ventricular muscle following heart disease, which is closely correlate to ventricular arrhythmia. Bone marrow stem cells (BMSCs) transplantation can improve damaged cardiac muscle; however, its effect on remodeling of ion channel is unclearly. OBJECTIVE: To detect the changes of HCN2 and HCN4 expression in left ventricle following BMSCs transplantation.METHODS: Five Sprague-Dawley (SD) rats, aged 3 weeks, were prepared for BMSCs by Percoll method. Additional 30 health, male, SD rats, were randomly divided into DMEM, cell transplantation, sham operation and control groups. At 4 weeks after model preparation, DMEM culture medium was injected into the infarcted area and surroundings with 5 points in the DMEM group. The 3rd generation of cultured BMSCs (200 μL, with 5×10~6 cells) were injected into rats in the cell transplantation group with the same methods. The mRNA and protein expression of HCN2 and HCN4 gene was detected by RT-PCR and Western blot respectively.RESULTS AND CONCLUSION: In non-infarcted region, the mRNA and protein expression of HCN2 and HCN4 among each groups had no significant difference (P > 0.05). Compared with the control and sham operation groups, mRNA and protein expression of HCN2 and HCN4 in surrounding of the infracted region was elevated in the DMEM group (P < 0.05), which was greater than that of the cell transplantation group (P < 0.05). The mRNA and protein expression of HCN2 and HCN4 was smaller in the center area of infracted region in the DMEM group than that of the control and sham operation groups (P < 0.05), which was similar to the cell transplantation group (P > 0.05). Acute myocardial infarction can increase mRNA and protein expression of HCN2 and HCN4 in infracted region surrounding. BMSCs transplantation may lower the fatality rate of ventricular arrhythmia by reducing HCN2 and HCN4 expression.

Objective To investigate the feasibility of dose verification of helical tomotherapy (HT) using the PTW Seven29 2D-ARRAY with Octavius phantom.Methods The 12 patients HT plan were verified with the PTW Seven29 2D-ARRAY combining Octavius phantom.The detector array was guided and registered by MVCT imaging,and measured dose distributions on the corresponding planes were compared with those calculated by the treatment planning system (TPS).Based on several different Gamma criteria,the Gamma analysis method was utilized to evaluate the dose verification.Results According to the different acceptance criteria combination of dose difference/distance to agreement at different threshold level including 3％/2 mm,3％/3 mm,3％/4 mm,3％/5 mm at TH5,TH10,TH20,TH30,the mean passing rates with γparameter ≤ 1 were all above 91.7％ and 93.9％ when PTW Seven29 2D-ARRAY was horizontal and vertical.The dose distribution measured by the 2D-ARRAY combining Octavius phantom was well consistent with that calculated by the TPS.Conclusions 2D-ARRAY with Octavius phantom can get satisfying results when used in HT plan dose verification and is a viable tool to replace traditional film dosimetry system in clinical quality assurance work.

Objective This study describes the protective effect of myocardial isehemic post- conditioning on ischemic-reperfused myocardium (I/ R) of diabetic rat and its Signaling mechanism. Methods Healthy SD rats weighing 25O-30Og were divided into 6 groups; (1) Blank control; (2) Ischemia-reperfusion; (3) Post conditioning; (4) Diabetic postconditioning ; (5) Diabetic ischemia-reperfusion; ( 6) Diabetic blank control group. Ten rats in each group were randomly selected. Introduction of diabetic rat model: 65 mg/kg STZ was injected into the intraperitoneal cavity, until 2 consecutive blood glucose measurements≥ 16.65 mmol/L were reached after48h. The diabetic model was successful when rats had following symptoms, such as more drinking, more eating, polyuria, weight loss and epilation. Langendorff isolated rat heart perfusion was used for the experiment. Following parameters were measured and compared: Coronary perfusion flow, myocardial infarct size, western blot for measurement of P-Akt, changes in myocardium and mitochondrian observed by Electron microscopy. Results Blood glucose concentration in diabetic group was (23. 15±2. 16) mmol/L and (4. 16±0. 31) mmol/L in non-diabetic group. There was a significant difference (P <0. 01) between the two groups. There were more coronary flow in post-conditioning groups (Post group and Dpost group) than ischemia-reperfusion groups (IR group and DIR group) (6.5±1.2、5.6±1.0 vs. 3.4±1.0、2.0±1.3). The myocardial infarction size was smaller in post-conditioning groups than in ischemia-reperfusion groups (25.2±2.1、34.2±3.6 vs. 47.5±3.5 、65.2±4.5). There was more expression of P-Akt and the myocardial fibers and mitochondrian in post-conditioning groups were better preserved. Conclusion Postconditioning has protective effects in diabetic rat hearts. The mechanism may be associated with Akt activation.