AIM:To study the electrophysiological effects of amiodarone on the pacemaker cells in guinea-pig left ventricular outflow tract under the conditions of hypoxia,acidosis and treatment with epinephrine.METHODS:The action potentials of the pacemaker cells in guinea-pig left ventricular outflow tract were recorded by conventional intracellular microelectrode technique.The effects of amiodarone on the spontaneous slow response potentials were investigated under the conditions of hypoxia,acidosis and treatment with epinephrine.RESULTS:(1) Amiodarone at concentration of 0.1 ?mol/L markedly decreased the rate of pacemaker firing (RPF) and maximal diastolic potential (MDP),lengthened 80% of the duration of action potential (APD80).Amiodarone at concentration of 1 ?mol/L significantly decreased the velocity of diastolic depolarization (VDD) and RPF,the maximal rate of depolarization (Vmax),MDP and amplitude of action potential (APA),lengthened 50% of the duration of action potential (APD50) and APD80.Amiodarone at concentration of 10 ?mol/L led to a significant decrease in VDD and RPF,Vmax,MDP and APA,a notable lengthening in APD50 and APD80 was also observed.(2) Under the condition of hypoxia and perfusion with deprived glucose content for 15 min,VDD,RPF,MDP,Vmax and APA decreased significantly,APD50 was shortened notably.Under the condition of hypoxia,amiodarone at concentration of 1 ?mol/L significantly decreased VDD,RPF and Vmax,increased MDP,lengthened APD50 and APD80 as compared to the cells treated with hypoxia only.(3) Perfusion with pH 6.8 solution for 10 min,VDD and RPF significantly decreased,Vmax and APA notably reduced,APD80 was markedly shortened.Under the condition of acidosis for 10 min,amiodarone significantly decreased VDD,RPF,MDP and APA,lengthened APD50 and APD80 as compared to the cells under the condition of acidosis only.(4) Perfusion of epinephrine at concentration of 10 ?mol/L for 10 min resulted in a significant increase in VDD,RPF,Vmax,MDP and APA,a notable shorting in APD50 and APD80 was also observed.Compared to 10 ?mol/L epinephrine group,1 ?mol/L amiodarone+ 10 ?mol/L epinephrine significantly reduced VDD,RPF,Vmax,MDP and APA,lengthened APD50 and APD80.CONCLUSION:Amiodarone markedly decreases the autorhythmicity of the pacemaker cells in guinea-pig left ventricular outflow tract.This electrophysiological effects were significantly influenced by hypoxia,acidosis and epinephrine.

Objective To explore the influence of naloxone hydrochloride injection on levels of IL-6,IL-8,IL-18 and TNF-α in patients with COPD complicated with respiratory failure.Methods A total of 60 COPD patients with respiratory failure were randomly divided into control group (n =30) and experimental group (n =30).The control group was given conventional medical treatment,while the experimental group was treated with naloxone on the basis of the control group.Results After treatment,the inflammatory factors IL-6,IL-8,IL-18,TNF-and blood gas indicators p(CO2) in the experimental group were significantly lower than the control group (P ＜ 0.05),and blood gas indicators p (O2) and pH were significantly higher than the control group (P ＜ O.05).The pulmonary function indexes FVC,FEV1 ％ and PEF in the experimental group were significantly higher than those in the control group (P ＜ 0.05).The hospital stay in the experimental group was significantly shorter than the control group (P ＜ 0.05).The total effective rate of the experimental group was significantly higher than that of the control group (P ＜ 0.05).Conclusion Naloxone hydrochloride injection is effective in the treatment of COPD patients with respiratory failure.

Objective To explore the influence of naloxone hydrochloride injection on levels of IL-6,IL-8,IL-18 and TNF-α in patients with COPD complicated with respiratory failure.Methods A total of 60 COPD patients with respiratory failure were randomly divided into control group (n =30) and experimental group (n =30).The control group was given conventional medical treatment,while the experimental group was treated with naloxone on the basis of the control group.Results After treatment,the inflammatory factors IL-6,IL-8,IL-18,TNF-and blood gas indicators p(CO2) in the experimental group were significantly lower than the control group (P ＜ 0.05),and blood gas indicators p (O2) and pH were significantly higher than the control group (P ＜ O.05).The pulmonary function indexes FVC,FEV1 ％ and PEF in the experimental group were significantly higher than those in the control group (P ＜ 0.05).The hospital stay in the experimental group was significantly shorter than the control group (P ＜ 0.05).The total effective rate of the experimental group was significantly higher than that of the control group (P ＜ 0.05).Conclusion Naloxone hydrochloride injection is effective in the treatment of COPD patients with respiratory failure.

Objective To explore the application value of serum CXC chemokine ligand 12(CXCL12)and CXC chemokine receptor 4(CXCR4)detection combined with Doppler ultrasound in the diagnosis of dangerous placenta previa.Methods A sum of 90 patients with dangerous placenta previa admitted to Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine in Hebei from June 2020 to January 2023 were collected as research subjects.According to the postpartum pathological results,they were grouped into the placental implantation group(n=38)and the non placental implantation group(n=52),while another 90 healthy pregnant women(with placenta attached to the anterior wall of the uterus)who underwent pregnancy examination in Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine in Hebei and matched with the patient's gestational age were regarded as the control group.The serum levels of CXCL12 and CXCR4 in each group were compared.ROC curve was applied to analyze the diagnostic efficacy of serum CXCL12 and CXCR4 levels for placental implantation.Using postoperative pathological results as the gold standard,the fourfold table method was applied to calculate the diagnostic efficacy of serum CXCL12 and CXCR4 combined with Doppler ultrasound in the occurrence of placental implantation.Results The serum levels of CXCL12(2.75±1.26 ng/ml,5.82±2.14 ng/ml,10.24±3.58 ng/ml)and CXCR4(1.84±0.78 ng/ml,4.47±1.83 ng/ml,8.32±2.763 ng/ml)in the control group,non placental implantation group and placental implantation group were increased successively,and the differences were significant(F=158.998,199.141,all P＜0.05).The detection of serum CXCL12 and CXCR4 combined with Doppler ultrasound in the diagnosis of placental implantation had an AUC of 0.948,and sensitivity and specificity were 92.11％and 86.54％,respectively,which was better than CXCL12,CXCR4,and Doppler ultrasound alone predicting separately(Z=2.266,2.682,3.472,P=0.023,0.007,0.001).Conclusion The expression levels of serum CXCL12 and CXCR4 in patients with dangerous placenta previa are increased.The combination of serum CXCL12 and CXCR4 with Doppler ultrasound may have good diagnostic efficacy for the occurrence of placental implantation in dangerous placenta previa patients.

Objective:To investigate the risk factors of postoperative recurrence in patients with primary brain glioma and to construct a prediction model.Methods:A total of 98 patients with primary brain glioma treated by radical surgery in Nanchong Central Hospital from January 2018 to January 2021 were retrospectively included, and were divided into recurrent group (40 cases) and non-recurrent group (58 cases) according to whether there was recurrence or not during the follow-up period. The independent influencing factors for postoperative recurrence in patients with primary brain glioma were evaluated by multivariate logistic regression. Logistic prediction model of postoperative recurrence risk of patients with primary brain glioma was established, and the predictive efficacy of each index was calculated by receiver operator characteristic (ROC) curve.Results:There were statistically significant differences between recurrent group and non-recurrent group in glioma World Health Organization (WHO) grade ( χ2=12.48, P<0.001), isocitrate dehydrogenase (IDH) 1/2 mutation ( χ2=13.24, P<0.001), mean platelet volume (MPV) ( t=5.34, P<0.001), and MPV/platelet count (PLT) ( t=9.73, P<0.001). Multivariate analysis showed that WHO grade Ⅲ-Ⅳ ( OR=8.54, 95% CI: 1.62-44.99, P=0.011), IDH1/2 wild type ( OR=9.08, 95% CI: 1.68-49.19, P=0.010), low MPV ( OR=0.46, 95% CI: 0.21-0.99, P=0.048) and low MPV/PLT ( OR=0.02, 95% CI: 0.01-0.03, P<0.001) were independent risk factors for postoperative recurrence in patients with primary brain glioma. The logistic prediction model based on the above indicators was logit ( P) =11.78+2.15×WHO grade+2.21×IDH1/2 mutation situation-0.78×MPV-200.70×MPV/PLT ( R2=0.785). The ROC curve analysis results showed that WHO grade, IDH1/2 mutation, MPV, MPV/PLT, and logistic prediction model P-value could all be used to predict the risk of postoperative recurrence in patients with primary brain glioma; The areas under the curve were 0.681, 0.684, 0.783, 0.920 and 0.964, respectively. In the area under ROC curve comparison of each indicator, the predictive performance of the logistic regression model P-value was significantly higher than that of other indicators (all P<0.05) . Conclusion:Postoperative recurrence in patients with primary brain glioma may be related to glioma WHO grade, IDH1/2 mutation and platelet related laboratory indexes. The model constructed based on the above indicators can be used to predict the recurrence risk in patients with primary brain glioma after surgery.