Accurate operation and installation circumstance of medical instruments and equipment directly affect their normal operation. Breakdown of medical instrument due to wrong operation accounts for 43% of all failures. This article makes a discussion on how to train staffs before operation,register utilization and maintenance,manage equipment by dedicated person and mak the best use of medical instrument.

OBJECTIVE:To evaluate and compare the current preparation methods for pseudo-ternary phase diagrams of pharmaceutical microemulsions.METHODS:Pseudo-ternary phase diagrams were prepared by using Tween-80,OP and lecithin as emulsifiers respectively,alcohol as assistant emulsifiers,isopropyl myristate or aethylis oleas as the oil phase,the difference in phase diagrams obtained with different preparation methods was compared with regard to the accuracy and au-thenticity of valid point.RESULTS:To O/W surfactant,difference in the area of phase diagrams was small,but the dis-tinction of accuracy and authenticity of valid point was great.To W/O surfactant,difference in the area of phase diagrams was great.CONCLUSION:It is recommended to select the preparation method according to the characteristics of the constituents and the types of microemulsions in order to establish accurate and dependable phase diagram,the end point of titration should be judged comprehensively.

Objective To evaluate the safety,efficiency and short-term results of cutting balloon coronary angioplasty.Method This procedure was performed on 63 lesions in 52 patients (male 94%,age 57?9 years).Results The overall procedural success rate for the cutting balloon angioplasty without predilation were 92.1%.Seven out of 9 cases of total occluded lesions had satisfactory results.Two cases of in-stent restenosis were also treated with CB successfully.Forty-three lesions were treated with cutting balloon followed by stents insertion.In 20 lesions treated with the cutting balloon alone,there was a marked reduction in the luminal stenosis from 78.8?11.6% to 7.2?5.6%.One patient developed pericardial tamponade 3 hours after cutting balloon angioplasty,which was resolved with pericardiocentesis.No severe dissection,no abrupt coronary closure,no emergency bypass surgery and acute myocardial infarction occurred.During 6 to 2 months' follow-up,only one patient treated by cutting balloon alone experienced angina pectoris and coronary angiography showed a restenosis, there were no further cardiac event.Conclusion Cutting balloon coronary angioplasty is a safe and effective interventional therapy with a high success rate and satisactory short-term results.

To study the clinical significance of the changes in PDGF and 6 keto PGF 1? in patients before and after cutting balloon angioplasty (CBA) and plain conventional balloon angioplasty (POBA). Blood was obtained from the coronary sinus. The levels of PDGF were determined by bioassay, and the levels of 6 keto PGF 1? were determined by ELISA. The results showed that the levels of PDGF and 6 keto PGF 1? were significantly different after PTCA between CBA group and POBA group ( P

Objective To examine effects of hydrogen peroxide on intracellular free calcium concentration(i) in cardiac myocytes and its antagonism by carvedilol. Methods A cell culture of neonatal rat cardiac myocytes was used for experimentation. They were divided into four groups, i.e. control group, hydrogen peroxide (H 2O 2) group, carvedilol group,and H 2O 2 + carvedilol group. Confocal microscope was used with Fluo-3/AM as calcium indicator to detect changes in i immediately and 15 minutes after H 2O 2 intervention, respectively. Results The intracellular fluoresence intensity of a single cardiae myocyts in the control group and carvedilol group was low. The intracellular fluoresence intensity of a single cardiac myocyte in H 2O 2 group was significantly higher than in the control group 15 minutes after intervention (P

Objective To evaluate the possibility and efficiency of nanoparticles as a new vector in vascular endothelial growth factor (VEGF) gene transfection. Methods Nanoparticle-VEGF (Np/VEGF)complex was prepared with poly (D, L-lactide-co-glycolide) (PLGA) loading VEGF165 gene using the multiple emulsion (w/o/w) technique. The envelopment efficiency and size of the complex were determined. Rat myocardial cells were cultured in vitro, and the Np/VEGF was transfected into the cultured myocardial cells. Then RT-PCR and ELISA were used to evaluate whether the Np/VEGF increased the level of gene expression. Four New Zealand rabbits were used, the suspension of Np/VEGF was injected into myocardial tissue of rabbits after thoracotomy. 96h after the operation, the tissue sections of the implant sites were observed with transmission electron microscope (TEM) to determine the process of nanoparticles as vectors for gene transfer to cardiac myocytes. Results The envelopment efficiency and size of the Np/VEGF complex thus prepared were 1.87% and 25-300nm respectively. RT-PCR and ELISA showed that VEGF gene could be successfully transfected into myocardial cells by nanoparticle, and NP/VEGF significantly enhanced gene transfection efficiency, and it was more effective than plasmid. 96h after the operation, a great number of nanoparticles were observed in myocardial cytoplasm and nucleus with TEM, and many nanoparticles began to dissolve and degrade, suggesting that the DNA was released slowly from the nanoparticles localized in the cytoplasmic compartment, and was then transferred into the nucleus. Conclusions NP/VEGF can act as a vector to transfect VEGF gene in vitro and in vivo, it significantly enhanced gene transfection efficiency, and it was more effective than plasmid.

Objective To construct a EGFP-labled recombinant plasmid of VEGF165 (vascular endothelial growth factor) gene, and to study the transfection and expression of VEGF165 eukaryotic expression plasmid in mesenchymal stem cells (MSCs). Methods pIRES2-EGFP-VEGF165 recombinant plasmid was constructed, which was then transfected into rat MSCs. ELISA and MTT were used to detect the expression level and biological activity of VEGF in the conditioned medium after transfection. Results There was a significant increase in VEGF protein in the MSCs after being transfected with pIRES2-EGFP-VEGF165. The conditioned medium after transfection showed the biological activity of stimulating the proliferation of endothelial cells. Conclusions The pIRES2-EGFP-VEGF165, a eukaryotic expression plasmid for VEGF165 gene, is constructed. High levels of VEGF protein expression can be obtained in the MSCs transfected with pIRES2-EGFP-VEGF165. The expressed protein has the biological activity of VEGF.

Objective To study the platelet activity changes in patients before and after percutaneous coronary cutting balloon angioplasty (CBA) and plain old balloon angioplasty (POBA) as well as its clinical significance.Methods Blood was obtained from the coronary sinus. Bioassay method used for assessment of PDGF. The plasma 6-keto-PGF 1a level was determined using ELISA.Results The amount of PDGF and 6-keto-PGF 1a were significantly different after PTCA between CBA group and POBA group (P

Objective To study the parameters of the postprandial plasma lipoproteins metabolism and the platelet activity change in the elderly patients with coronary heart disease(CHD). Methods 48 elderly patients with CHD (CHD group) and 30 healthy elderly subjects (control group) were enrolled in this study. The levels of plasma lipoproteins including TG, CH, LDL-C and HDL-C, plama PDGF bioactivity, and vWF plasma concentration were measured at 12 hours after fasting and 4 hours after a fat-rich meal. Results The plasma levels of pre-prandial and postprandial TG, CH, LDL-C, PDGF and vWF in the CHD group were significantly higher than those in the control group, while plasma HLD-C level in the CHD group was significantly lower than that in the control group. Compared with fasting state, the levels of plasma TG, CH and LDL-C in the postprandial state significantly increased, but plasma HDL-C level did not significantly decreased. The plasm PDGF and vWF values of CHD group in the postprandial state significantly elevated. Conclusion These data suggested that the plasma lipoproteins metabolism of the elderly patients with CHD was abnormal, and the platelets activation in the elderly patients with CDH was correlated with the changes of postprandial plasma lipoproteins metabolism.

Objective: To observe the effect of static magnetic fields(SMF) on the proliferation of bone mesenchymal stem cells(MSC) in human. Methods: The MSC were obtained by using gradient centrifuge method, and then selected by the adhesive method. The third generation cells were irradiated by use of static magnetic fields at different intensities for 5 days(8 h/d). The method of MTT was employed to evaluate the level of proliferation. The parameters regarding the variation of the cell cycle were detected with the flow cytometry(FCM). Results: As compared to the control group, the proliferative rate of the MSC exposed to 0.05 mT SMF was significantly higher; there was no difference between the 0.10 mT group and control group; howere, cell proliferation was attenuated significantly when SMF intensity was 0.50 mT and 1.00 mT. No abnormal ploidy was found in any group. Conclusion: The effect of SMF on the proliferation of MSC is dependent on the magnetic intensity. 0.05 mT SMF can accerate the proliferation of MSC. 0.10 mT SMF have no effects on the growth of MSC. Wherease, 0.50 mT and 1.00 mT SMF can attenuate the growth of MSC.