AIM:To investigate the impact of Kir2.1 channels on abnormal spontaneous pacemaker activities induced by hypokalemia and to elucidate the underlying mechanisms.METHODS:Human induced pluripotent stem cell-derived cardiomyocytes(hiPSC-CMs)were transfected with lentiviral particles containing sequences for human Kir2.1,the Kir2.1-E224G mutant,or Kir4.1.Patch clamp techniques were employed to examine the effects of low extracellular potassium concentration([K+]e)of 1 mmol/L on the resting membrane potentials and whole-cell currents of the cells in each group,assessed via both current and voltage clamp modes.RESULTS:Under conditions of 1 mmol/L[K+]e,cur-rent clamp data revealed that hiPSC-CMs overexpressing Kir2.1 channels exhibited both hyperpolarized and depolarized resting membrane potentials,with the depolarized state triggering abnormal pacemaker activities.In contrast,cells overex-pressing the Kir2.1-E224G mutant or Kir4.1 channels displayed only hyperpolarized resting membrane potentials.Voltage clamp analysis indicated that hiPSC-CMs overexpressing Kir2.1 channels produced"N"-shaped whole-cell currents,whereas cells expressing the Kir2.1-E224G mutant or Kir4.1 exhibited typical K+currents.CONCLUSION:Kir2.1 channels play a crucial role in mediating hypokalemia-induced abnormal spontaneous pacemaker activities in human car-diomyocytes through their inward rectification properties.

AIM:To investigate the impact of Kir2.1 channels on abnormal spontaneous pacemaker activities induced by hypokalemia and to elucidate the underlying mechanisms.METHODS:Human induced pluripotent stem cell-derived cardiomyocytes(hiPSC-CMs)were transfected with lentiviral particles containing sequences for human Kir2.1,the Kir2.1-E224G mutant,or Kir4.1.Patch clamp techniques were employed to examine the effects of low extracellular potassium concentration([K+]e)of 1 mmol/L on the resting membrane potentials and whole-cell currents of the cells in each group,assessed via both current and voltage clamp modes.RESULTS:Under conditions of 1 mmol/L[K+]e,cur-rent clamp data revealed that hiPSC-CMs overexpressing Kir2.1 channels exhibited both hyperpolarized and depolarized resting membrane potentials,with the depolarized state triggering abnormal pacemaker activities.In contrast,cells overex-pressing the Kir2.1-E224G mutant or Kir4.1 channels displayed only hyperpolarized resting membrane potentials.Voltage clamp analysis indicated that hiPSC-CMs overexpressing Kir2.1 channels produced"N"-shaped whole-cell currents,whereas cells expressing the Kir2.1-E224G mutant or Kir4.1 exhibited typical K+currents.CONCLUSION:Kir2.1 channels play a crucial role in mediating hypokalemia-induced abnormal spontaneous pacemaker activities in human car-diomyocytes through their inward rectification properties.

Objective:To explore the application of Balint group activities in the doctor-patient communication skills training for standardized residency training of internal medicine.Methods:The students from Batch 2018 and some from Batch 2019 participating in the standardized residency training in Renmin Hospital of Wuhan University were selected as the research subjects. SPSS 22.0 was used to perform paired t test for comparison before and after training, and the SEGUE scale was used to evaluate the doctor-patient communication ability of the physicians before and after the training of the Balint group. A questionnaire survey was performed to collect their understanding of doctor-patient communication status and evaluate the training activities. Results:All the residents recognized the importance of doctor-patient communication and clarified the main reasons for the communication of doctors and patients. After receiving the training of doctor-patient communication focusing on group activities, the total score of SEGUE scale increased from (15.40±5.65) to (19.84±1.92), and the residents significantly improved their ability in such five dimensions as stopping inquiry, understanding patients, passing information, collecting information and ready to start ( P<0.001), with a satisfaction rate of 92.00% (69/75) for training methods and contents. Conclusion:The doctor-patient communication ability of the residents needs to be further improved. Balint group activities have enriched the form of doctor-patient communication training, which is helpful for doctors to strengthen their professional confidence and build a harmonious doctor-patient relationship.

Objective To investigate the relationship between the tube voltage and radiation dose as well as image quality in adult upper airway digital radiography (DR).Methods We used CDRAD2.0 contrast details phantom and PMMA to simulate adult upper airway. With different tube voltages,the phantom was exposed using automatic exposure control system (AEC).The entrance surface dose( ESD),dose area product(DAP) and mAs in every exposures were recorded.The image quality factors(IQF) of all images were calculated. Results With tube voltage increasing,ESD,DAP,mAs decreased and IQF value enhanced.There were statistically significance ( F =45.15,26.41,29.26,56.53,P ＜ 0.05 ).ESD,DAP,mAs significantly increased with tube voltage less than 75 kV,began to decrease when tube voltage more than 75 kV,tended to be on the balance in 75 -80 kV.At the same time,the fluctuation of IQF value was no statistical difference in 50 - 75 kV of tube voltage,but was statistical significance in 75 -90 kV( F =11.35,P ＜0.05 ).So,the image quality of adult upper airway with different tube voltage had no significant difference.Conclusions The appropriate tube voltage was 75 kV to 80 kV in the upper airway DR.The IQF value can be provided as the clinical evaluation index of image quality.

Objective To investigate the effect of dexmedetomidine on inflammatory response during the perioperative period in patients with acute craniocerebral trauma.Methods Seventy ASA Ⅰ-Ⅳ patients of both sexes,aged 20-68 yr,with craniocerebral trauma,who required decompressive craniectomy within the next 24 h,were randomly divided into 2 groups (n =35 each) ∶ control group (group C) and dexmedetomidine group (group D).Anesthesia was induced with fentanyl,propofol and cisatracurium and maintained with remifentanil,sevoflurane and propofol and intermittent iv boluses of cisatracurium.In group D,dexmedetomidine 1 μg/kg was infused over 10 min,followed by infusion at 0.4 μg· kg-1 · h-1 for 2 h.Venous blood samples were taken before induction of anesthesia (baseline),2 h after the beginning of operation,at the end of operation and at 24 h after operation (T1-T4) to determine the concentrations of serum neurone specific enolase (NSE),interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α).Results Compared with group C,the concentrations of serum NSE,IL-6 and TNF-α were significantly decreased in group D (P ＜ 0.05).The concentrations of serum NSE,IL-6 and TNF-αwere significantly higher at T2 and T3,and the concentration of serum TNF-α was significantly lower at T4 than at T1 in group C (P ＜ 0.05).The concentrations of serum NSE and IL-6 were significantly higher at T2 and T3 and lower at T4 and the concentration of serum TNF-α was significantly higher at T3 and T4 than at T1 in group D (P ＜0.05).Conclusion Dexmedetomidine protects the brain against acute craniocerebral trauma by inhibiting systemic inflammatory response during the perioperative period.

Objective To analyze the neurological complications in treatment of severe thoracolumbar spinal deformity with one stage posterior vertebral column resection (pVCR) and discuss the related risk factors. Methods There were 67 patients with severe thoracolumbar spinal deformity who underwent one-stage pVCR from February 2000 to September 2010.There were 29 males and 38 females at an average age of 31.4 years old(range,14-62 years).There were 21 patients at age less than 18 years old and 46 at age more than 18 years old.Patients were divided into four pathological types:severe scoliosis group(n=11,mean Cobb angle 90.4°),kyphoscoliosis group(n=25,mean scoliosis 94.5°,and mean kyphosis 65.5°),angular kyphosis group(n=28,mean kyphosis 74.3°)and global kyphosis group(n=3,mean kyphosis 91.1°).of all the patients,59 patients underwent primary surgery and eight underwent revision surgery.Surgical methods included posterior apex vertebral column resection,segemental pedicle screw fixation and correction as well as 360° bone fusion.Neurological complication was statistically analyzed. Results The average follow-up was 14 months (range,3-69 months),which showed severe neurologic complication in eight patients(11.9%)after surgery.Severe neurologic complication occurred in three patients (4.5%),among whom one patient presented delayed complete paraplegia 23 hours after surgery.Five patients had mild neurologic deficits(7.5%),the incidence of which was higher than 23.1%for thoracic osteotomy (P<0.05).Multilevel pVCR had high rate of neurological complications (P<0.05).The incidence rate was 33.3% for patients with preoperative neurologic compromise and 7.3%for patients mthom preoperative neuroiogic compromise (P<0.05).The incidence rate was increased in the revision surgery (P<0.05).Eight patients with neurological deficits had kyphotic angle of raore than 60°although there was no statistical difference (P>0.05). Conclusions pVCR is an effective surgical method for the correction of severe thoracolumbar spinal deformity.The neurological complications,however,should be paid attention to the surgeons.The risk factors for neurologic complications include improper manipulation,massive blood losing,preoperative neurologic compromise,osteotomy at thoracic rein,multi-level vertebrectomy,revision surgery and severe kyphosis.

Objective To investigate CT and MRI findings of rare cystic disease of the pancreas.Methods Elven cases with rare cystic disease of the pancreas underwent plain and contrast-enhanced CT and MR imaging before operation were reviewed.The clinical presentations and imaging findings were analysed.Among eleven cases,four were epidermoid,four were lymphepithelial cyst and three were lymphangioma.Results (1) Epidermoids located in the tail of the pancreas with smooth wall,the density of parenchyma of the lesons was the same as spleen at CT plain scan.On contrast-enhanced CT and MRI,the parenchyma of the lesions showed the same enhanced pattern with spleen.(2)Lymphepithelial cysts often occurred in olderly men.The lesions appeared as multilocular masses with definite border,isodensity at CT plain scan,and mixed iso-hyperintensity on both T_1WI and T_2WI images.After injection of contrast medium,the wall and septum of the lesions were enhanced.(3)Lymphangiomas were multilocular cystic lesion in the body-tail of the pancreas,hypodense at CT plain scan,and long T_1 and T_2 signal intensity at MRI plain scan.The septum and wall of the lesions were slightly enhanced on contrast-enhanced images.The lesions were not communicated with the pancreatic duct but pancreatic ducts were compressed and slightly shifted.Conclusion CT and MRI findings of rare neoplastic cystic disease of the pancreas are of certain characteristics.