AIM: To investigate the effect of zacopride, an inward rectifier potassium channel agonist, on ouabain-induced arrhythmias in adult rats, and to explore the underlying electrophysiological mechanism.METHODS: Using ouabain to establish in vitro and in vivo arrhythmic rat models, the effects of zacopride on ouabain-induced arrhythmias were observed.The technique of whole-cell patch clamp was used to observe the effects of zacopride on inward rectifier potassium current (IK1), resting membrane potential (RMP) and delayed afterdepolarizations (DADs) in single rat ventricular myocyte.RESULTS: Zacopride at 1 μmol/L significantly reduced total number of premature ventricular beats, and the duration and incidence of ventricular tachycardia and ventricular fibrillation induced by ouabain in rat hearts in vitro (P<0.05).In anesthetized rats, zacopride at 15 μg/kg significantly reduced total number of premature ventricular beats, and the duration and incidence of ventricular tachycardia and ventricular fibrillation induced by ouabain (P<0.05).IK1 was significantly inhibited by ouabain (P<0.05), which was partially and even completely reversed by zacopride at 0.1~10 μmol/L.RMP value was significantly reduced by ouabain (P<0.05), and then increased to different levels after treatment with zacopride (0.1~10 μmol/L).Zacopride at 1 μmol/L showed its maximal effect and RMP was restored to normal level.Moreover, zacopride at 1 μmol/L markedly suppressed ouabain-induced DADs in single rat ventricular myocyte.The incidence of DADs decreased from 91.67% to 12.50% after zacopride was applied (P<0.05), and this effect was abolished by 1 μmol/L BaCl2.CONCLUSION: Inward rectifier potassium channel agonist zacopride significantly inhibits ouabain-induced ventricular arrhythmias in adult rats.The mechanism is related to increased RMP level and inhibition of DADs by activation of IK1 channel.

Aim To observe the effect of antibody NCX-3F10 on the main ion current of rat ventricular myocytes and its effect on arrhythmias induced by ischemia/reperfusion(I/R).Methods ① The whole-cell patch clamp technique was employed to record the Na+/Ca2+ exchange current(INa/Ca) and other major ion currents in rat ventricular myocytes.② The rat models of arrhythmia induced by ischemia/reperfusion were established by ligating the left coronary artery to in vivo and in vitro.Then the effects of antibody on the arrhythmia were observed.③ The IonOptix ion imaging system was used to observe the effect of antibody on calcium transients in single ventricular myocytes.Results ① The antibody NCX-3F10 dose-dependently inhibited INa/Ca from 5 to 40 mg·L-1.The IC50 for outward and inward currents was 11.15 and 11.69 mg·L-1, and the maximum inhibitory rates were 61% and 62%, respectively.The antibody also had an inhibitory effect on calcium current(ICa-L), and had no significant effect on inward rectifier potassium current(IK1), transient outward potassium current(Ito) and sodium current(INa).② In the isolated rat heart group I/R, 100% rats showed ventricular tachycardia, and 88.89% rats had ventricular fibrillation.After administration of antibody NCX-3F10(10 mg·L-1) 5 min before reperfusion, the incidence of ventricular tachycardia decreased to 44.43%(P<0.05), and the duration of ventricular tachycardia and ventricular fibrillation was also shortened remarkably(P<0.05).③ In the anesthetized rats after administration of antibody NCX-3F10(50 μg·kg-1) 5 min before reperfusion, the incidence and duration of ventricular tachycardia,the incidence and duration of ventricular fibrillation, and total number of ventricular premature beats were significantly decreased(P<0.05).④ From 5 to 40 mg·L-1, NCX-3F10 antibody decreased calcium transient amplitude in rat single ventricular myocytes dose-dependently(P<0.05).Conclusions The NCX-3F10 antibody shows significant arrhythmic effects on ischemia-reperfusion induced arrhythmia in rats both in vitro and in vivo, the underlying mechanism of which is related to NCX and L-type calcium current inhibition and calcium overload reduction by the NCX antibody.

OBJECTIVETo evaluate the sensitivity and specificity of optimized sequential screening program of colorectal cancer, and provide evidence for the further optimization of colorectal cancer screening program.

METHODSUsing cluster sampling method, 4 administrative villages were selected from Jiashan county as a census district in 2011 to 2013. Volunteers of 40 to 74 years old in the census were recruited, and tested by both optimized sequential screening (including questionnaire survey and fecal occult blood test) and colonoscopy for colorectal cancer. Sensitivity and specificity of different screening methods were calculated, respectively.

RESULTSA total of 2 607 volunteers took both simultaneously screening and colonoscopy at the same time. 20 colorectal cancer cases, 85 advanced adenoma cases, 271 non-advanced adenomas cases, and 141 non-adenomatous polyps cases were detected. Sensitivity of optimized sequential screening for colorectal cancer, advanced adenomas, and non-advanced adenomas were 70.0% (14/20) , 57.6% (49/85) and 36.5% (99/271) , specificity was 68.7% (1 776/2 587) , 69.2% (1 746/2 522) and 68.9% (1 610/2 336) , respectively. Sensitivity of the fecal occult blood test of colorectal cancer, advanced adenomas and non-advanced adenomas were 70.0% (14/20) , 47.1% (40/85) and 26.6% (72/271), specificity was 79.4% (2 053/2 587), 79.9% (2 014/2 522) and 79.6% (1 860/2 336). The sensitivity of fecal occult blood test and those of optimized sequential screening for colorectal cancer, advanced adenomas was not significant (χ(2) = 0.00, 1.91, all P values > 0.05). Sensitivity of questionnaire survey of colorectal cancer, advanced adenomas and non-advanced adenomas were 10.0% (2/20), 14.1% (12/85), 12.9% (35/271), specificity was 87.6% (2 266/2 587), 87.7% (2 211/2 522), 87.6% (2 046/2 336). There were no significant difference between non-advanced adenomas. The sensitivity of advanced adenomas and non-advanced adenomas showed no significant decline when the following six term were removed from screening programs: chronic diarrhea, chronic constipation, mucus or bloody history, history of chronic appendicitis or appendectomy surgery, chronic cholecystitis or gallbladder surgery, adverse events in the history of life, while the sensitivity of colorectal cancer remained nearly the same 70.0% (14/20), 52.9% (45/85), 31.4% (85/271) (χ(2) = 0.38, 1.61, all P values > 0.05).

CONCLUSIONCurrent optimized sequential screening programs for colorectal cancer in China have a high sensitivity and specificity. However, further optimization is viable and necessary.

Adenoma ; China ; Colonic Polyps ; Colonoscopy ; Colorectal Neoplasms ; Early Detection of Cancer ; Humans ; Mass Screening ; Occult Blood ; Sensitivity and Specificity ; Surveys and Questionnaires

OBJECTIVE: To establish a deep-learning architecture based on faster region-based convolutional neural networks (Faster R-CNN) algorithm for detection and sorting of red ginseng (Ginseng Radix et Rhizoma Rubra) with internal defects automatically on an online X-ray machine vision system. METHODS: A Faster R-CNN based classifier was trained with around 20 000 samples with mean average precision value (mAP) of 0.95. A traditional image processing method based on feedforward neural network (FNN) obtained a bad performance with the accuracy, recall and specificity of 69.0%, 68.0%, and 70.0%, respectively. Therefore, the Faster R-CNN model was saved to evaluate the model performance on the defective red ginseng online sorting system. RESULTS: An independent set of 2 000 red ginsengs were used to validate the performance of the Faster R-CNN based online sorting system in three parallel tests, achieving accuracy of 95.8%, 95.2% and 96.2%, respectively. CONCLUSION The overall results indicated that the proposed Faster R-CNN based classification model has great potential for non-destructive detection of red ginseng with internal defects.