Cardiac arrhythmias occur in a wide variety of conditions where increased intracellular Ca2+ is known to occur, including myocardial ischemia, cardiac glycoside toxicity, congestive heart failure, and excessive prolongation of action potential duration. The multifunctional Ca2+/calmodulin dependent protein kinaseⅡ(CaM kinase) is an important physiologic target for intracellular Ca2+ and regulates key control points for intracellular Ca2+ homeostasis, including L-type Ca2+ current, release and uptake of Ca2+ from the sarcoplasmic reticulum. Since CaM kinase is uniquely positioned to affect Ca2+ sensitive ionic currents and resultant arrhythmias, CaM kinase may also be an effective antiarrhythmic drug target. The transient inward current (Iti) triggers delayed afterdepolarizations, which are a likely cause of Ca2+ overload arrhythmias. The identity of Iti is controversial, but appears to result from different ionic currents depending on the experimental conditions. These currents are likely activated by intracellular Ca2+ because Iti always follows excessive intracellular Ca2+ concentrations (［Ca2+］i). The studies from our laboratory indicate that three different ［Ca2+］i sensitive currents, which could contribute to Iti, are present in rabbit ventricular myocytes. These currents are the Na+/Ca2+ exchanger, the Ca2+ activated Cl- current, and the Ca2+ activated non-selective cation current. We also found that Iti was suppressed by CaM kinase inhibitory peptides in the presence of physiologic solutions. These data support the hypothesis: CaM kinase can augment Iti during clinically relevant conditions, which are associated with increased ［Ca2+］i, and thus act as a proarrhythmic signaling molecule.

Objective To study clinical manifestations,laboratory variables,imaging features and therapies of refractory Mycoplasma pneumoniae pneumonia (RMPP).Methods The retrospective analysis of clinical data was conducted in 45 children with RMPP and 74 children with Mycoplasma pneumoniae pneumonia (MPP)admitted to department of pediatrics.The general data,clinical manifestations,laboratory variables,imaging features and therapies were compared between two groups.Results As compared to MPP,the age(6.14 ±3.35)y,febrile days(9.49 ± 5.28)d,the hospitalized days(11.45 ±3.42)d were significantly higher than that of MPP group (P <0.001);RMPP had higher rations of unilateral pulmonary infiltration[41(91.11%)],large consolidation shadows[35(77.78%)], pulmonary[21(46.67%)]and extrapulmonary complications[24(51.33%)](P <0.05);CRP,ESR,LDH and IgM were increased,the difference was statistically significant (P <0.01);Thirty -seven cases(82%)of RMPP had to add ceftriaxone sodium,thirty -two cases(71.7%)of RMPP had to add glucocorticoid,,Bronchofiberoscope lavages were used in six cases of RMPP.Only one case of RMPP occured sequela.Conclusion The older children,the per-sistent high fever,large consolidation shadows of pulmonary,pulmonary and extrapulmonary complications,high level of serum CRP,ESR,LDH and IgM are the clinical related factors of RMPP.The combination of cephalosporins and (or)glucocorticoid might consider for the cases who have no effect with macrolides.The effect is sure for RMPP with Bronchofiberoscope lavages.

Objective: To observe the safety and efifcacy of excimer laser coronary atherectomy (ELCA) for treating the patients with coronary chronic total occlusion (CTO). Methods: A total of 3 coronary CTO patients treated by ELCA in our hospital from 2015-01 to 2016-11 were analyzed. The patients received guide steel wire gone through occlusion segment under the guidance of offside coronary angiography; drug-eluting stent implantation was conducted after ELCA treatment. The operative success rate with complication was observed and the occurrence of MACE was followed-up. Results: The device performing and interventional therapy were succeed in all 3 patients. No coronary dissection, perforation, slow relfow and thrombosis were occurred during the operation; no angina, myocardial infarction, target vessel revascularization and death were observed by follow-up study. Conclusion: Application of ELCA combining drug-eluting stent implantation was safe and effective for treating the patients with coronary CTO.

AIM: To study the time-dependent effects of diabetes mellitus (DM) on the development of cardiac remodeling in untreated streptozotocin (STZ)-induced rats with acute myocardial infarction (MI). METHODS: The left anterior descending coronary arteries were ligated 10 weeks after DM induction without any therapy. Transmission electron microscopy, echocardiography, heart weight to tibial length ratios, histological examination, microarray analysis, and real time-PCR were utilized to monitor the changes up to 56 d. RESULTS: After MI, the diabetic rats experienced lower survival rate compared to non-diabetic animals. The pathophysiologic changes indicated that DM accelerated the cardiac remodeling post-infarction. In primary examination, 164 genes related to cardiac remodeling were found to be candidates for hierarchical analysis, such as leucine-rich PPR-motif containing (interleukin-6 signaling pathway), procollagen type I and III, fibronectin-1, RT1, and TIMP-1, etc. The gene expression profile at 14 d in diabetic rats were comparably similar to both 14 d and 28 d in non-diabetic rats, while such changes at 28 d and 56 d in diabetic rats was also similar to the ones at 56 d in non-diabetic rats. CONCLUSION: The accelerated cardiac remodeling of post-infarction in STZ-induced untreated diabetic rats seems be associated with the different profile of gene expressions.

Objective: To explore the application value and safety of low-dose dobutamine stress echocardiogram (LDDSE) in patients of low-flow/low-gradient aortic stenosis combining left ventricular dysfunction with transcatheter aortic valve replacement (TAVR). Methods: A total of 5 eligible consecutive patients with contradiction of routine surgical valve replacement and going to receive TAVR in our hospital from 2013-10 to 2016-07 were enrolled. The mean aortic valvegradient, maximum flow velocity, each stroke volume and ejection fraction were recorded before and during LDDSE examination. The patients having confirmed diagnosis of true severe aortic stenosis with left ventricular contractile reserve received TAVR, for those without left ventricular contractile reserve received drug therapy or TAVR conditionally. The changes of cardiac function and NT-proBNP level were observed after TAVR. Results: All 5 patients showed positive finding in LDDSE; the mean aortic valve gradient ≥40mmHg and stroke volume≥20% implied that the patients had true severe aortic stenosis with left ventricular contractile reserve. No adverse reaction occurred during and after LDDSE. TAVR was performed in 4 patients and 1 was waiting for TAVR or balloon dilatation since temporary lacking of valve. The post-operative cardiac function was improved in all patients and NT-proBNP level was declined continuously. Conclusion: LDDSE examination could be considered in patients of aortic stenosis combining left ventricular dysfunction, low-flow and low-gradient to clarify ventricular contractile reserve and the severity of aortic stenosis. If the patients with ventricular contractile reserve, TAVR was recommended which was the effective treatment for relevant patients.

Objective To evaluate the safety and clinical efficacy of renal artery stent treatment for severe atherosclerotic renal artery stenosis (ARAS) in the elderly. Methods In a prospective nonrandomized study in our hospital from January 2003 to April 2008, 147 consecutive elderly patients with ARAS (diameter reduction ≥ 65％) underwent percutaneous transluminal renal angioplasty and stenting (PTRAS) for resistant hypertension or reserving renal function. They were followed up for 6- 66 months and the effects of the procedure on renal function, blood pressure and cardiovascular events were observed. Results The success rate of PTRAS was 100％. During 6-66 months of follow up, both systolic and diastolic blood pressure were significantly decreased, and less antihypertensive medication was taken (P<0.01). Serum creatinine was significantly decreased during 6-48 months of follow up (P<0. 05) and did not change significantly during 54-66 months of follow up (P>0. 05). Blood urea nitrogen was significantly decreased during 6-24 months of follow up (P<0.05) and did not change significantly during 30-66 months of follow up (P>0.05). Complications related with the procedure occurred in 7 cases (4.8％). 17 patients failed to follow up (11.6％) and in 18 cases cardiovascular events occurred (12.2％), including 4 cases of renal events (2. 7％), 4 cases of myocardial infarction (2.7％), 2 cases of stroke (1.4％) and 8 cases of cerebral and cardiovascular events (5.4％) during 6-66 months of follow up. The survival rates of free-of-events at year 1, 2, 3, 4 and5 were 91.0%(121/133), 90.2%(83/92), 78.5%(51/65), 73.8%(31/42) and 54.8%(17/ 31), respectively. The survival rates at year 1, 2, 3, 4 and 5 were 94.0% (125/133), 90. 2% (83/ 92), 84.6%(55/65), 73. 8%(31/42) and 61.3%(19/31), respectively. Conclusions Renal artery stent as treatment for ARAS in the elderly has a beneficial effect on blood pressure control and on renal function during middle and long term follow up. The treatment may be helpful in reduction of cardiovascular events and mortality, which should be investigated further.

Since epidemiologic studies have reported a modestly increased risk of oncogenesis associated with certain electromagnetic fields (EMF), popular media and scientists have raised concerns about possible health hazards of environmental exposure to EMF. Laboratory-based experiments have shown that a variety of biological responses were induced by EMF, although these results were controversial and conflicting. The non-thermal effects of low energy EMF,the possible interaction of EMF with biological system have become focus topics in the biolectromagnetic fields. This paper focuses on recent studies of static and extremely low frequency electromagnetic fields, especially the interactive mechanism between EMF and cellular membrane and protein kinase signal transduction pathways. The potential genetic toxicity and risk evaluation are also discussed. However, the existence of some positive findings and the limitations in the set of studies suggest a need for more work.
DNA Damage ; radiation effects ; Electromagnetic Fields ; adverse effects ; Environmental Exposure ; Gene Expression Regulation ; Humans ; Neoplasms, Radiation-Induced ; etiology

Objective To study the correlation between morphological characteristics of coronary artery calcified plaques and luminal stenosis of local coronary artery segments with 64-slice computed tomography.Methods One hundred and eleven patients who had undergone 64-slice computed tomographic coronary angiography(CTCA)and conventional coronary angiography(CAG)were retrospectively analyzed.The calcified plaques were classified as punctate,nodular,strip-like and nubbly in long-axis view of coronary artery lumen,and were classified as crescent,semilunar,round moon and circinate in short-axis view.The morphologic characteristics of these calcified plaques on CTCA were retrospectively analyzed and compared with luminal stenosis of CAG results.Results Among 528 calcified coronary segments which were analyzed in 111 patients,there were 383(72.5%)punctate calcified plaque segments and 145(27.5%)of non-punctate plaques.There were 34(23.4%,34/145)non-punctate calcified plaques which caused severe stenosis(≥75%),including 4(11.8%)nodular,8(23.5%)stripe-like and 22(64.7%)nubbly calcified plaques on the long-axis view,and 0(0.0%)cresent,8(23.5%)semilunar,18(52.9%)round moon and 8(23.5%)circinate calcified plaques on the short-axis view.The ratios of different morphological coronary artery calcifications which caused severe stenoses were significantly different with each other(all P＜0.01).Conclusion Different figures of coronary artery calcified plaques demonstrate different degrees of stenoses of local coronary artery lumen.Severe stenoses were mostly caused by nubbly calcified plaque on long-axis view,round moon and circinate calcified plaque on short-axis view.

Objective: To evaluatethe efficacy of renal artery stenting combining optimal drug therapy in patients with atherosclerotic renal artery stenosis.
Methods:This is a prospective cohort study for patients who received percutaneous renal artery stenting in our hospital from 2011-09 to 2013-03. All patients had conifrmed diagnosis of atherosclerotic renal artery stenosis combing hypertension and/or renal functional damage. Thepatients received optimal drug therapy for anti-platelet and blood pressure, lipids, glucose controlling, and they were followed-up for at least 12 months to observe the improvement of blood pressure and renal function.
Results:There were 149 patients at the mean age of (61.54 ± 9.63) years and 185 renal artery stenosis with stent implantation;the average stenosis rate was (83.11±7.30)%and the success rate of operation was 99.32%(148/149). During follow-up period, the patients had increased estimated glomerular ifltration rate (GFR) compared to base line from (76.49 ± 22.50) ml/(min·1.73 m2) to (84.09 ± 28.79) ml/(min·1.73 m2), P<0.05 and decreased 24 h urinary protein from 0.1(IQR 0.02, 0.5) g to 0.04 (IQR0.01, 0.11)g, P<0.001;less type of drug therapy for hypertension from 2.22 to 1.56, P<0.05, decreased clinical and 24h dynamic systemic/diastolic blood pressure from (153.4 ± 15.6)/(83.77 ± 12.60) mmHg to (134.6 ± 14.4)/(73.57 ± 9.12) mmHg and from (143.32 ± 19.87)/(80.51 ± 11.33) mmHg to (124.44 ± 14.90)/(69.09 ± 9.49) mmHg, all P<0.05.
Conclusion:Renal artery stenting combining optimal drug therapy may improve blood pressure controlling and renal function in strictly selected patients with atherosclerotic renal artery stenosis.

Objective: To study the aortic root imaging and clinical application in 15 patients with transcatheter aortic valve implantation (TAVI).
Methods: A total of 15 patients with severe aortic valve stenosis received TAVI in our hospital from 2011-03 to 2013-11 were studied. The CT scan and transthoracic echocardiography were conducted to measure the aortic root anatomy and the differences of annulus size between CT and echocardiography were calculated. The prosthetic valves were selected based on CT measurement. The pre-operative accuracy of measurement was evaluated by the follow-up study at 6 months after operation.
Results: The CT measured pre-operative aortic annulus short diameter was (21.5 ± 2.4) mm, long diameter was (27.3 ± 2.7) mm, the average inner diameter was (24.4 ± 2.4) mm, left ventricular out lfow (LVOF) tract long diameter was (28.3 ± 4.5) mm, the average inner diameter of LVOF was (24 ± 3.5), ascending aorta diameter was (35.3 ± 4.4) mm. The Venus Medtech A-Valve implanted in 8 patients with #26 and in 7 patients with #29. The average inner diameter of aortic annulus measured by CT was larger than transthoracic echocardiography, P<0.001. During 6 months follow-up period, no patients had aortic root rupture, coronary obstruction, moderate and severer aortic and peri-aortic regurgitation. There were 4 patients with atrio-ventricular block and received permanent pacemaker implantation.
Conclusion: There is a difference for aortic annulus size by CT and transthoracic echocardiography measurements. CT may presisely assess the aortic root morphology and provide strong support for TAVI.