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.

ObjectiveTo observe the clinical efficacy of Qiju Dihuangtang combined with Chinese medicine fumigation in the treatment of dry eye and its effect on the levels of interleukin-6 （IL-6） and matrix metalloproteinase-9 （MMP-9） in tears. MethodA total of 120 patients with dry eye of liver-kidney Yin deficiency syndrome who were treated in the Department of Ophthalmology， The Second Affiliated Hospital of Liaoning University of Traditional Chinese Medicine（TCM） from october 2019 to october 2021 were randomized into the observation group and control group. The control group was given sodium hyaluronate eye drops， and the observation group was treated with sodium hyaluronate eye drops， Qiju Dihuangtang， and Chinese medicine fumigation. The treatment lasted 30 days for both groups. The changes of ocular surface disease index （OSDI）， TCM syndrome score， tear secretion （SIT）， tear film breaking up time （BUT）， corneal fluorescein staining （FL）， and tear interleukin-6 （IL-6） and matrix metalloproteinase-9 （MMP-9） were observed. ResultAfter the treatment， the total effective rate was 90.0% （54/60） in the observation group and 75.0% （45/60） in the control group （χ²=4.675， P<0.05）. After treatment， the OSDI score and TCM syndrome score were lower than those before treatment in both groups （P<0.05）， and lower in the observation group than in the control group （P<0.05）. After treatment， the SIT and BUT were higher （P<0.05） and FL score was lower （P<0.05） than those before treatment in both groups. After treatment， the improvement of the above indicators in the observation group was better than that in the control group （P<0.05）. After treatment， the levels of IL-6 and MMP-9 were lower than those before treatment in both groups （P<0.05）， and lower in the observation group than in the control group （P<0.05）. ConclusionQiju Dihuangtang combined with Chinese medicine fumigation can effectively improve subjective symptoms， promote tear secretion， prolong BUT， enhance corneal epithelial repair， and reduce the levels of tear IL-6 and MMP-9 in the treatment of dry eye.

OBJECTIVETo evaluate efficacy and optimal cut-off-point through cerebral vascular hemodynamic indexes (CVHI) examination to predict stroke.

METHODSA number of 20,333 people at 35 years old and over were checked by CVHI and accumulative score was calculated according to the value of detected indexes. Risk factors of stroke were investigated simultaneously. One hundred and sixty-eight patients with stroke occurred during 4-year following up. Typical syndromes and signs stroke were used as golden standard to evaluate screening efficacy of CVHI.

RESULTSScore of optimal cut-off-point of cerebral vascular hemodynamic indexes was under 75 in ROC curve analyses. Sensitivity, specificity, accuracy, positive and negative predictive values, positive and negative likelihood ratios as well as Youden's index for predicting stroke within 4 years after examination were found to be 87.50%, 67.70%, 67.86%, 2.21%, 99.85%, 2.71, 0.18 and 0.55 respectively. Sensitivity and positive predict values for predicting cerebral vascular thrombosis were superior to predicting cerebral hemorrhage. Positive predicting value in risk exposure population was higher than that of overall population. Coefficiency of variation of cerebral vascular hemodynamic examination was 4.03%. The agreement rate of examination between two physicians was 97.62% and Kappa value was 0.94.

CONCLUSIONThe score of optimal cut-off-point of cerebral vascular hemodynamic indexes examination was 75. Both Efficacy and reliability for predicting stroke seemed to be good, especially for predicting cerebral vascular thrombosis.

Adult ; Aged ; Brain ; physiopathology ; Female ; Hemodynamics ; Humans ; Male ; Middle Aged ; Stroke ; diagnosis ; physiopathology

Using the cyclodextrin bonded polysiloxane (bikis〔（2,6-di-O-pentyl-3-O-hex-6-O-enyl)-pentakis(2,6-di-O-pentyl-3-O-methyl)-β-cyclodextrm-polysiloxane〕) as gas chromatographic stationary phase, α-hydroxy acetones were separated and the values of the enantiomeric excess(e.e) of 3-hydroxy-2-butanone were determined. The results showed that the high resolution gas chromatography (HRGC) using the chiral gas chromatographic stationary phase could determine the productive rate of the asymmetric hydrogenaton reaction and evaluate the enantoselectivity of the catalyst system.

We present a minimal invasive technique for the treatment of broncho-pleural fistula (BPF) after pulmonary lobectomy with lung cancer. 2 cases of BPF were found at the 4th and 7th day after pulmonary lobectomy respectively. They were reoperated on by VATS, direct resuture of stump and consolidation with acrylic or fibrin glue. Both cases were cured. Authors consider mentioned procedure might be a feasible therapeutic approach for early broncho-pleural fistula.

Objective To study the clinical application of video-assisted thoracoscopic surgery (VATS). Methods Clinical records of 78 cases of VATS from July 1998 to December 2002 were retrospectively analyzed. There were 40 cases of bullectomy for spontaneous pneumothorax, 12 cases of surgical exploration for chest trauma, 9 cases of wedge resection for solitary pulmonary nodules, 6 cases of pleural biopsy combined with pleurodesis, 4 cases of resection for mediastinal tumor, 4 cases of pulmonary lobectomy, 2 cases of broncho-pleural fistula following lobectomy and 1 case of resection for esophageal leiomyoma. Results A conversion to open surgery was required in no cases, but a supplementary mini incision was needed in 5 cases because of the adhesion of pleural cupula. The intrathoracic drain was all removed within 48 postoperative hours with exception of 3 middle-old aged patients with spontaneous pneumothorax in whom the continuous air leakage was observed and the drain was removed on 7, 8 and 13 postoperative days, respectively. The delayed healing of drain site was seen in 5 cases. The incidence of operative complications was 10 3% (8/78). Conclusions Broad prospects exists in the clinical application of VATS, but the costs of the disposable is subject to reduce. The application of suture or knotting under thoracoscope may save medical costs.