ABSTRACT
Objective The recurrence rate of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) remains relatively high. The aim of this study was to investigate the predictive value of rs2200733 polymorphism for AF recurrence after RFCA. Methods Fifty-three AF patients underwent RFCA guided by the magnetic navigation system between July 2015 and September 2016 in Wuxi People’s Hospital. We obtained the baseline data on the patients, conducted genotyping for rs2200733 variants, and followed up the patients for symptoms and complications by electrocardiography (ECG) and dynamic ECG. Using Cox survival analysis, we determined the independent predictors of AF recurrence after RFCA and the sensibility and specificity of predicting AF recurrence at 12 and 24 months post-operatively. Results All the patients were Han Chinese, followed-up for 21.6 ± 9.5 months, and 25 (47.2%) of them experienced AF recurrence at 6.6 ± 5.3 months after RFCA. Kaplan-Meier survival analysis revealed a significant association between rs2200733 polymorphism and AF recurrence in the additive and recessive models (P < 0.001), and multivariate Cox analysis showed the rs2200733 polymorphism (recessive model) to be an independent predictor of post-RFCA AF recurrence (OR = 3.184, 95% CI: 1.378-7.357, P = 0.007). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of rs2200733 TT in predicting AF recurrence at 12 months were 64%, 81%, 70%, 76% and 74%, and those at 24 months were 60%, 82%, 75%, 70%, and 72%, respectively. Conclusion The rs2200733 polymorphism is an independent predictor of AF recurrence after RFCA, and its high specificity indicates that it could be used as a tool for screening Han Chinese patients with AF for RFCA.
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Objective To evaluate the diagnostic value of interferon-γ release assay of blood and pleural effusion for tuberculous pleurisy.Methods Fifty-six adult patients with suspected tuberculous pleurisy were enrolled in our study.The blood and pleural effusion interferon-γ release assay were measured by T-SPOT.TB test in 38 pleural tuberculosis patients and 18 nontuberculous pleurisy controls.The diagnostic sensitivity,specificity,predictive value of T-SPOT.TB in pleural effusion mononuclear cells (PE-MC) and peripheral mononuclear cells (PBMC) were analyzed.Results The sensitivities and specificities,positive predictive values and negative predictive values,respectively,of the PE-MC and PBMC for diagnosing were as follows:86.5％(95％ confidence interval[CI] 71.2％-95.5％) and 100％(95％CI 90.5％-100％);52.9％(95％CI 27.8％-77.0％) and 35.3％(95％CI 14.2％-61.7％);80.0％(95％CI 64.4％-90.9％) and 77.1％(95％CI 62.7％-88.0％);64.3％(95％CI 35.1％-87.2％) and 100％(95％CI 54.1％-100％).By ROC curve analysis,a cut-off value of 47SFC/2.5 × 105 cells in PE-MC showed a sensitivity of 89.2％ and a specificity of 88.2％.Conclusion T-SPOT.TB in PE-MC could be an accurate diagnostic method for tuberculous pleurisy in TB endemic settings.Moreover,47SFC/2.5 × 105 cells might be the optimal cut-off value for diagnosing tuberculous pleurisy.
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Objective The mechanisms of docosahexaenoic acid (DHA) protecting the cardiovascular system have not yet been clarified. This study was to investigate the vasorelaxative effect of 13,14-epoxy docosapentaenoic acid (13,14-EpDPE) on coronary arterioles in normal rats and its action mechanisms.Methods We isolated coronary artery smooth muscle cells (CASMCs) from normal rats by enzyme digestion, examined the open probabilities of the large conductance calcium-activated potassium (BK) channels in inside-out single channel configuration in the presence of different concentrations (0, 1, 10 and 100 pmol/L) of 13,14-EpDPE, and recorded the BK currents with the patch clamp in whole cell configuration. Then we assessed the coronary arterial relaxation by measuring dilatory responses to 13,14-EpDPE in pre-contracted tissues with or without pre-treatment with iberiotoxin.Results In the presence of 0, 1, 10 and 100 pmol/L of 13,14-EpDPE, the open probabilities of the BK channels were 0.25±0.03, 0.34±0.03, 0.44±0.06 and 0.85±0.16 (n=6), respectively, significantly increased at 100 pmol/L as compared with 0, 1 and 10 pmol/L (P<0.05). The BK channels were activated by 13,14-EpDP in a concentration-dependent manner and its half-effect concentration was (15.94±1.21) pmol/L. The current density was increased from (58.27±16.35) to (95.94±23.00) pA/pF (P=0.002) after 10 pmol/L 13,14-EpDP perfusion when the stimulation voltage was 100 mV. 13,14-EpDPE dilated the isolated coronary arterioles in a dose-dependent manner, and its effects were abolished after pre-treatment with iberiotoxin (100 nM).Conclusion 13,14-EpDPE can dilate coronary arterioles by activating BK channels in CASMCs, which might be one of the mechanisms underlying its protective effect on the cardiovascular system.
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<p><b>OBJECTIVE</b>To investigate the changes of open probability (Po) of large conductance Ca(2+)-activated K(+) channel (BK channel) in diabetic coronary smooth muscle cells and elucidate the underlying cellular electrophysiology mechanisms of coronary dysfunction.</p><p><b>METHODS</b>Rat coronary smooth muscle cells were isolated from control group and diabetic group. BK single channel currents were recorded by patch clamp technique in inside-out configuration. Open probabilities were calculated and compared between two groups. After exposure to DHS-1, a specific BK channel activator, Po at 0.2 and 1 µmol/L free Ca(2+) were compared between control and diabetic groups.</p><p><b>RESULTS</b>In the presence of 0.2 µmol/L free Ca(2+), the Po at baseline was significantly lower in diabetic rats than in control rats (0.0032 ± 0.0012 vs. 0.095 ± 0.036, P < 0.05). Cytoplasmic application of DSH-1 significantly increased the Po to 0.335 ± 0.096 (P < 0.05 vs. baseline) in control rats, whereas DSH-1 had no effect in diabetic rats (Po = 0.022 ± 0.018, P > 0.05 vs. baseline). In the presence of 1 µmol/L free Ca(2+), the Po at baseline was also significantly lower in diabetic rats than in control rats (0.210 ± 0.055 vs. 0.458 ± 0.077, P < 0.05). Cytoplasmic application of DHS-1 further robustly enhanced Po to 0.823 ± 0.019 (P < 0.05 vs. baseline) in control rats and to 0.446 ± 0.098 in diabetic rats (P < 0.05 vs. baseline of diabetic rats; P < 0.05 vs. control rats with DHS-1).</p><p><b>CONCLUSION</b>The decrease of Po of BK single channel in coronary smooth muscle cells may be a potential cause for coronary dysfunction in diabetic rats.</p>