Objective: To explore the application value of ablation catheter for pacemaker atrial lead restoration in relevant patients.
Methods: A total of 6 patients with atrial lead dislodgement after pacemaker implantation were selected for our study. The atrial lead restoration was conducted by using ablation catheter via femoral vein pathway.
Results: The average operational time was (15.0 ± 3.7) min which was obviously less than traditional operational time. The position of electrode restoration was ideal with well immobilization.
Conclusion: Ablation catheter is feasible for arial lead restoration in patients with atrial lead dislodgement after pacemaker implantation.

AIM: To study the effects of hydrogen peroxied (H 2O 2) on cell proliferation and transcription of gelatinase A (MMP-2) and its inhibitor (TIMP-2) in vascular smooth muscle cells (VSMC). METHODS: Cell proliferation and toxicity by H 2O 2 were tested through MTT. The expression of MMP-2 mRNA and TIMP-2 mRNA in VSMC were evaluated by RT-PCR. RESULTS: The present study showed that H 2O 2 (more than 300 ?mol/L)was lethal to VSMC. 0 01-50 ?mol/L H 2O 2 promoted proliferation of VSMC in a time-dependant manner. A value (optical density) was reached to peak at 24 h after continuing stimulation of 10 ?mol/L H 2O 2. MMP-2/?-actin mRNA ratio significantly increased after stimulation with 1 ?mol/L?10 ?mol/L H 2O 2. TIMP-2/?-actin mRNA ratio was not significantly fluctuated at 12 h?24 h?36 h?48 h after continuing stimulation with 1 ?mol/L, 10 ?mol/L, and 50 ?mol/L H 2O 2.CONCLUSION: H 2O 2 at suitable concentrations stimulated proliferation of VSMC and induced transcription of MMP-2 gene in VSMC. There was no effect of H 2O 2 on transcription of TIMP-2 gene in VSMC. These results imply that H 2O 2 takes part in the pathological course of vascular remodeling through VSMC.

AIM: To evaluate effects of diltiazem on platelet hyperreactivity in situations associated with endothelial injury and their possible relationship to cytosolic calcium concentration. METHODS: Blood samples were collected at 7 time points from 35 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) who received combined diltiazem and aspirin/ticlopidine therapy or aspirin/ticlopidine therapy alone. Platelet expression of glycoprotein Ⅱb/Ⅲa and cytosolic calcium concentration were measured, respectively, by whole blood flow cytometry and fluorospectrophotometry. The effects of diltiazem of different concentrations on expression of glycoprotein Ⅱb/Ⅲa were also studied in vitro in blood samples from patients with chronic stable angina. RESULTS: Of the two treatments, aspirin/ticlopidine therapy did not prevent an acute increase of expression of glycoprotein Ⅱb/Ⅲa 5 minutes and 10 minutes after first inflation and 10 minutes after PTCA, whereas combined diltiazem and aspirin/ticlopidine therapy had a significant inhibitory effect. In the group receiving aspirin/ticlopidine therapy, there was a short-term elevation of platelet [Ca~(2+)]i immediately following PTCA which was significantly reduced by diltiazem treatment. Expression of glycoprotein Ⅱb/Ⅲa was significantly inhibited in vitro by diltiazem in the concentration of 200 ?g/L or higher, but not 50 ?g/L. CONCLUSIONS: Combined diltiazem and aspirin/ticlopidine therapy significantly inhibited platelet activation that continued in the presence of conventional aspirin/ticlopidine treatment. Antiplatelet effects of diltiazem were probably a consequence of reduction of platelet [Ca~(2+)]i and may only be achieved in higher than therapeutic concentrations. [

AIM: To investigate the effects of non-invasive ischemic preconditioning on nitric oxide (NO)/endothelin-1 (ET-1) imbalance and gas exchange impairment following limb ischemia reperfusion in patients undergoing unilateral lower extremity surgery with tourniquet. METHODS: Twenty-seven patients aged 25-65 years, whose tourniquets duration varied from 1 h to 1.5 h and matched American Society of Anesthesiologists Physical Status Ⅰ-Ⅱ, were randomized into two groups: a control group (n=14) and a ischemic preconditioning group (IPC group, n=13) in which patients received three cycles of 5 min of ischemia/5 min of reperfusion before tourniquet inflation. Radial arterial blood gas, plasma malondialdehyde (MDA) and NO, serum ET-1 and interleukin-6 (IL-6) were measured just before tourniquet inflation(T_0), 1 h after inflation(T_1), and 0.5 h(T_2), 2 h(T_3), 6 h(T_4), 24 h(T_5) after tourniquet deflation. Meanwhile NO/ET-1 ratio, alveolar-arterial oxygen gradient (P_(A-a)DO_2) and intrapulmonary shunt (Qs/Qt) were calculated. RESULTS: In control group, arterial partial pressure of oxygen (PaO_2) were decreased, while P_(A-a)DO_2 and Qs/Qt were increased significantly at T_4 compared to the baselines at T_0 (P<0.01). Plasma NO levels and NO/ET-1 ratios decreased gradually after tourniquets deflation and statistical significances were observed at T_3 (P<0.01) with a valley at T_4 (P<0.01) and recovered to baselines at T_5. Serum ET-1, IL-6 and plasma MDA began to increase remarkably after T_3 (P<0.05 or P<0.01), peaked at T_4 and dropped slightly at T_5. The changes above-mentioned could be well attenuated by the application of IPC (P<0.05 or P<0.01) except PaO_2 (P>0.05). CONCLUSION: Clinical application of unilateral tourniquet within safe time limit (1.5 h) may lead to limb ischemia reperfusion and further pulmonary gas exchange impairment, which could be partially attenuated by the application of IPC via alleviating NO/ET-1 imbalance.

Defibrillators, Implantable ; Electric Countershock ; Humans ; Ventricular Fibrillation

OBJECTIVES: Serum matrix metalloproteinase (MMP) levels are associated with cardiovascular diseases. However, the causal associations between serum levels of specific MMPs and venous thromboembolism (VTE) remain unclear. The present study sought to explore the causal relationship between serum MMP levels and VTE by using the Mendelian randomization (MR) method. METHODS: In this study 2-sample MR study, the exposure data on serum MMP levels were derived from genome-wide association studies involving 21,758 individuals from 13 cohorts of European descent. The outcome data on VTE, including deep vein thrombosis and pulmonary embolism, were derived from the FinnGen research project. The primary method used was the inverse-variance weighting method. The MR-Egger intercept test and the Cochran Q test were used to evaluate pleiotropy and heterogeneity. RESULTS: Using the inverse-variance weighting method, higher serum MMP-12 levels were found to be associated with an increased risk of VTE (odds ratio, 1.04; 95% confidence interval, 1.01 to 1.07; p=0.001). Moreover, there was a weak association between the levels of certain MMPs and VTE. Sensitivity analyses revealed no significant heterogeneity and pleiotropy in our study, and the Steiger directionality test did not reveal a significant reverse causation association. CONCLUSIONS There is a causal association between MMP-12 levels and VTE, which may have substantial implications for the diagnostic and therapeutic strategies used for VTE.

Fatal arrhythmias, heart failure, and sudden cardiac death after myocardial ischemia/infarction are serious threats to human health. In recent years, studies have shown that spinal cord stimulation (SCS) can balance autonomic activity, inhibit myocardial structural remodeling, improve blood flow to ischemic myocardium, effectively reduce the incidence of arrhythmia, heart failure and sudden cardiac death after myocardial ischemia/infarction, but its specific mechanism has not yet been fully elucidated. The effect of SCS on cardiac function may be achieved by inhibiting neural remodeling, or by ameliorating structural remodeling and electrical remodeling. This article reviews the progress on the role and mechanism of SCS in myocardial ischemia/infarction.
Coronary Artery Disease ; Heart Failure ; Humans ; Myocardial Infarction ; therapy ; Myocardial Ischemia ; Myocardium ; Spinal Cord Stimulation

OBJECTIVETo investigate the vasodilating effect of capsaicin (CAP) on rat mesenteric artery and its mechanism.

METHODSThe third branch of the superior mesenteric artery in male Sprague-Dawley rat (250-350 g) was excised, the periadventitial fat and connective tissue were removed and the mesenteric artery was dissected into 2 mm rings. Each ring was placed in a 5 ml organ bath of DMT 610M system and the tension was recorded.

RESULTSCAP (10(-9)-10(-5) mol/L) relaxed endothelium-intact and endothelium-denuded mesenteric artery pre-constricted by phenylephrine (10(-5) mol/L), and the vasodilation in endothelium-intact mesenteric artery was stronger than that in endothelium-denuded one. Pretreatment with either L-NAME (3 X10(-4) mol/L), an inhibitor of nitric oxide synthase(NOS), or CGRP8-37 (2 X 10(-6) mol/L), an antagonist of calcitonin gene-related peptide (CGRP), for 30 min significantly attenuated the relaxation of endothelium-intact mesenteric artery induced by CAP. CGRP (10(-10)-3 X10(-8) mol/L) relaxed endothelium-intact and endothelium-denuded mesenteric artery pre-constricted by phenylephrine, and the vasodilation in endothelium-intact mesenteric artery was stronger than that in endothelium-denuded one. Substance P did not relax the mesenteric artery pre-constricted by phenylephrine.

CONCLUSIONCAP has partial endothelium-dependent relaxation effect on rat mesenteric artery, which may be mediated by activating the endothelial NOS-NO pathway. The endothelium-independent relaxation in rat mesenteric artery induced by CAP may be mediated by CGRP.

Animals ; Calcitonin Gene-Related Peptide ; metabolism ; Capsaicin ; pharmacology ; In Vitro Techniques ; Male ; Mesenteric Arteries ; drug effects ; physiology ; Peptide Fragments ; metabolism ; Rats ; Rats, Sprague-Dawley ; Vasodilation ; drug effects

Adult ; Aorta, Thoracic ; injuries ; Coronary Vessels ; injuries ; Humans ; Male ; Tomography, X-Ray Computed

Objective To evaluate the significance of AFP-IgM, this is one of new tumor markers, in the diagnosis of primary hepatocellular carcinoma (PHC). Methods The contents of AFP-IgM and AFP in serum of 103 healthy subjects, 74 patients suffered primary hepatic carcinoma, 27 patients affected by liver cirrhosis and 63 patients affected by chronic hepatitis were detected by means of enzyme linked immunosorbent assay and electrochemiluminescence. No-PHC is comprised of liver cirrhosis,chronic hepatitis and health subjects as control group. Results The area under ROC curve of AFP was larger than that of AFP-IgM (0.85 vs 0.72, Z=3.21) and the best cut-off value of AFP-IgM and AFP was 3×105-AU/L and 10 ug/L respectively, which was determined by ROC curve. Under the cut-off value, the sensitivity of AFP- lgM and AFP for PHC were 64.9% and 79.7%, and the specificity were 75.6% and 80.3%, yet their efficacies were similar. However, for early diagnosis of liver cancer (stage Ⅰ and Ⅱ), the area under ROC curve of AFP-IgM was larger than that of AFP (0.91 vs 0.82,Z=1.73). The sensitivity of AFP-IgM andAFP were 94.4% and 72. 2%, and the specificity were 81.9% and 79.9%. The differences of AFP-IgMand AFP for early diagnosis of liver cancer were statistically significant. When both of the test results combined AFP-IgM with AFP are positive, it can be diagnosed as liver cancer. The specificity of combineddetermination of the two forms was 89.1%, and the efficacy was 79. 0%. Conclusions Both of thesensitivity and specificity of the AFP-IgM test were higher than that of the AFP for early diagnosis of livercancer. We also found that combined determination of the two forms significantly increased the specificityand the positive predictive value for the diagnosis of PHC, thus AFP-IgM was of especially significance forearly diagnosis of liver cancer.