18 patients with atrioventricular nodal reentant tachycardia (AVNRT)and 5 patients with atrioventricular reentrant tachycardia (AVRT) with AVN double pathway (AVNDP) received radiofrequency ablation of slow pathway with inferior approach in order to modify AVN. AVNRT was induced in slow-fast form in 16 patients, in fast-slow form in one patients,and in coexistent slow-fast and fast-slow forms in one patients. Selective ablation of slow pathway was achieved in 18 patients. AVRT was induced in 5 patients (one obvient accessory pathway, 4 concealed accessory pathways) ,4 patients with reentrant cirucit of consisting of anterograde conduction by slow pathway of AVN and retrograde conduction by accessory pathway (AP) , one patient coexistent AVRT and AVNRT. Slow pathway in 5 patients and AP in 3 patients were successfully ablated. Junctional rhythm appeared in 21 patients during duation of discharge of radiofrequency current. No severe complicationwere noted. AVNRT in one patient recurred during a follow-up period of 1 to 15 months. The patient experienced second catheter ablation and was successed. It was suggested radlofrequency ablation of slow pathway with Inferior approach may be a method with high rate of success and less complication.

Objective To characterize the electroanatomical mapping and to assess the value of radiofrequency ablation of atrial tachycardia (AT) in left atria. Methods Nine patients with AT in left atria were studied. Three-dimensional electroanatomical maps were constructed in left atrium using electroanatomical mapping system (Carto). The type of AT (focal or macroreentrant) was identified by the electroanatomical maps, and the ablation targets were at the earliest activation sites or the isthmus of circuit. Results There were ten ATs in 9 cases. The relatively early A waves were recorded in middle, distal or proximal parts of coronary sinus catheter. Nine focal ATs were diagnosed. The activation maps demonstrated that the earliest activation sites were at the ostium of pulmonary veins ( n =5), posterior area of left atrium ( n =2), ostia of left atria appendage ( n =1) or left atria appendage ( n =1) respectively. One macroreeentrant AT was diagnosed, whose circuit propagated through the isthmus, formed by the right superior pulmonary vein and fossa ovalis. Eight focal ATs were all ablated successfully at the earliest activation sites, and one AT from left atria appendage was ablated unsuccessfully. Line of ablation was performed at the isthmus of the macroreentrant AT. During a period of 6-30 months follow-up, one patient with focal AT recurred and underwent another ablation with successful result. No complication occurred. The procedure time and the fluoroscopic time were 90-140 min, 8-16 min respectively in successful cases. Conclusion These results suggest that electroanatomical mapping of AT in left atria may facilitate rapid and accurate identification of the type of AT and guide ablation safely or effectively with less fluoroscopic time and higher success rate, especially in unsuccessful cases with conventional technique.

Objective To evaluate clinically electroanatomical mapping and ablation of cardiac arrhythmias under the Carto system. Methods Fifty-six patients with various tachycardias indicated for electrophysiological study and radiofrequency ablation were included in this study, among of whom, 49 suffered from supraventricular tachycardia, and 7 ventricular tachycardia (VT). Carto system was utilized during ongoing tachycardia or sinus rhythm, 7F Navi-Star catheter was introduced into the interested cardiac chamber and underwent three-dimensional electroanatomical mapping. The mechanism and origin of cardiac arrhythmia were assessed by activation and propagation map, with which to guide radiofrequency ablation. Results The success ablation rate was 94.6% (53/56). One right accessory pathway (AP), one atrial tachycardia (AT) and one atypical atrial flutter (AF) had failed session. The procedure time was 128?59 minutes, and the fluoroscopic time 14?12 minutes. One patient had complcation of pneumothorax. No conduction block occurred. After follow-up of 1-14 months, one left AT recurred and had another succssful session. Conclusion The study demonstrates that Carto system is a safe and effective tool and may be applied for mapping and ablation of various tachyarrhythmias. It is helpful to guide catheter ablation and shorten fluorocopic time by its ability of associate intracardiac electrograms with their three-dimensional anatomic structure. It also lessen complication and recurrence by tagging the critical cardiac structures and utilize its location memory function. Our experience suggest that carto system has important role in the guidance of mapping and ablation in AT、AF、VT and complex or recurrent AP cases.

Objective To find out a quick,simple and convenient method of determining the viability of Oncomelania hupen-sis. Methods O. hupensis snails were stained for 30 minutes by 0.05%water soluble dye neutral red,0.5%methylene blue,red ink,methylene blue-eosin-borax(MEB)and 0.4%trypan blue,respectively. The soft tissue samples of the snails were observed by a stereoscopic microscope after crushing their shells. Results The vital snails were stained and the dead were unstained in the neutral red. The vital and dead snails were unstained in methylene blue. However,the vital and dead snails were stained in red ink. The partial vital and dead snails were stained in MEB. The vital snails were stained and the partial dead were stained in trypan blue. Conclusion The use of 0.05%water soluble dye neutral red is simple,rapid and accurate in determination of the viability of O. hupensis.

Objective To evaluate left atrial function serial change after circumferential pulmonary vein ablation(CPVA)for paroxysmal atrial fibrillation using tissue Doppler echocardiography.Methods One hundred and eight patients with paroxysmal atrial fibrillation underwent CPVA guided by CARTO.Tissue Doppler imaging and conventional echocardiography were underwent 48 h before CPVA,48 h,1 month,3 month and 6 month after CPVA.Results One hundred and six patients with paroxysmal atrial fibrillation finished CPVA successfully.Compared tO 48 h pre-CPVA,left atrial diameter and volume decreased 48 h,1 month,3 month,6 month after CPVA,significant change were found at 3 month,6 month after CPVA(P＜0.05).Left ventricular end-diastolic diameter(LVEDD),left ventricular end-systolic diameter(LVESD).left ventricular ejection fraction(LVEF),mitral flow E revealed no significant change(P＞0.05).Mitral flow A decreased significantly 48 h after CPVA(P＜0.05),restored significantly after 3 month.Tissue Doppler parameter S'and E'revealed no significant change(P＞0.05)through the period,A'decreased significantly 48 h after CPVA(P＜0.05),restored significantlv after 1 month.Conclusions Left atrial diameter and volume decreased after CPVA.Left atrial active contraction function decreased shortly after CPVA(LA stunning),and restored progressively.

The ergonomics of equipment is important,it is essential to make the ergonomic evaluation in the stage of design. The operation of expanded shelter is a typical form of combination of human labor and machine. The fuzzy comprehensive evaluation model is founded. The high-level factor set include the states of operation, the ratio of every state time to the total time is the corresponding weight for the elements in high-level factor set, the lower-level factor set include the elements which influence the states of operation. For the elements in lower-level factor set, the corresponding weight is given by the experts.

Objective To evaluate the effects of TIMP-1 and Ang-1 gene-modified BMSCs transplantation on the left ventricular function of rats with myocardial infarction.Methods The rat BMSCs were.transfected with eukaryotic expression plasmid encoding TIMP-1 or/and Ang-1 gene by liposome.Acute myocardial infarction was made in male rats by ligation of the left anterior descending (LAD) coronary artery.BMSCs carrying TIMP-1 or/and Ang-1 gene were injected into the ischemic myocardium after LAD ligatior.Four weeks after the administration,cardiac function was assessed by echocardiography and the hearts were harvested and sectioned for immunohistochemistry to examine the apoptosis,the collagen content and angiogenesis density.Results TIMP-1 and Ang-1 genemodified BMSCs transplantation significantly improved the cardiac function,myocardial apoptosis was alleviated,collagen content decreased and the angiogenesis density in border-zone was increased significantly (P＜0.05).Conclusions The results suggest that the combination of TIMP-1 and Ang-1-gene modified BMSCs transplantation can improve the cardiac function of rats with myocardial infarction.The increase of the blood supply,the alleviation of myocardial apoptosis and ventricle remolding after myocardial infarction possibly play important roles in the mechanism.

Objective To design and develop an air purification system for intensive care ambulances,which can effectively purify the air in the compartment and sterilize the microbes in the air.Methods By integrating titanium dioxide photocatalysts with air filtration materials,an air purification system was designed that was capable of effective sterilization of microbes in the air via photocatalytic oxidation and decomposition,and of effective filtration of particles in the air through HEPA filters.The protection effect was evaluated by air filtration and sterilization tests in accordance with the related national standards.Results The air cleanliness could reach the 100 000 level with bacteria counts no more than 1 CFU per pan for 15 minutes in the ambulance compartment when the air purification system worked normally,which could meet the demands of environmental hygienic standards for intensive care units.Conclusion The air purification system can effectively purify and sterilize the air in the compartment of an intensive care ambulance.The effects of air purification meet the requirements of related hygienic standards,which can satisfy the demands of treatment and intensive care for the victims in the ambulance.

AIM: To investigate alteration of inward re ctifier potassium current (I K1) in atrial myocytes and mRNA expression of gene Kir2.1 encoding I K1 in atrial myocardial tissue in patients with chronic atrial fibrillation (AF) compared to that with sinus rhythm (SR).METHODS: Single myocytes were isolated by enzymatic dissociation with the chunk method an d the ionic current was recorded using whole cell patch clamp technique. The sem i-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure the mRNA expression of Kir2.1 in atrial myocardial tissue, and the g ene GAPDH was used as an internal control.RESULTS: (1) The I K1 density was increased in AF group at hyperpolarizing pot entials, at -120 mV the current densities was (-5.71?0.65) pA/pF in AF group (n=28 cells from 7 patients) and (-4.26?1.22) pA/pF in SR group (n=35 cells from 9 patients) (P0.05).CONCLUSIONS: The increase in I K1 at hyperpolarizing potentials may be related to th e atrial electrophysiological remodeling in chronic human AF. The increased I K1 density in atrial myocytes in AF group without alteration of Kir2.1 mRNA expression in atrial tissue suggests that I K1 may be mediated at post-transcriptional levels.

Objective:To develop and optimize a novel assay for determination of cytotoxicity based Calcein -AM release.Methods:The target cells stained by Calcein-AM dye,then effectors and targets were incubated at E/T ratios from 30∶1-1∶1 for 4 h at 37℃,and the supernatant of reactions were detected by Fluorescence-Measurement to analyze specific cytotoxity.Results:The optimal excitation and emission wave lengths of Calcein were 485 nm and 515 nm.Dilutions of target cells stained by Calcein-AM had a linear relationship with measured fluorescence values.The Calcein-AM dye used to stain the living cells was shown to have a low spontaneous leakage rate-less than 15% in 4 hours at 37℃.Cytotoxicity activity of CIK showed a significant and positive correlation with E/T ratio when incubated at 4 h.Conclusion:The developed cytotoxicity test by Calcein-AM release is accurate and can avoid the application of radioactive reagents.