[Objective] To explore the relationship between neutrophil activation under cardiopulmonary bypass (CPB) and the incidence of cardiac surgery-associated acute kidney injury (CS-AKI). [Methods] This prospective cohort study enrolled adult patients who scheduled for cardiac surgery under CPB at West China Hospital between May 1, 2022 and March 31, 2023. The primary outcome was acute kidney injury (AKI). Blood samples (5 mL) were obtained from the central vein before surgery, at rewarming, at the end of CPB, and 24 hours after surgery. Neutrophils were labeled with CD11b, CD54 and other markers. To assess the effect of neutrophils activation on AKI, propensity score matching (PSM) was employed to equilibrate covariates between the groups. [Results] A total of 120 patients included into the study, and 17 (14.2%) developed AKI. Both CD11b⁺ and CD54⁺ neutrophils significantly increased during the rewarming phase and the increases were kept until 24 hours after surgery. During rewarming, the numbers of CD11b⁺ neutrophils were significantly higher in AKI compared to non-AKI (4.71×10⁹/L vs 3.31×10⁹/L, Z=-2.14, P<0.05). Similarly, the CD54⁺ neutrophils counts were also significantly higher in AKI than in non-AKI before surgery (2.75×10⁹/L vs 1.79×10⁹/L, Z=-2.99, P<0.05), during rewarming (3.12×10⁹/L vs 1.62×10⁹/L, Z=-4.34, P<0.05), and at the end of CPB (4.28×10⁹/L vs 2.14×10⁹/L, Z=-3.91, P<0.05). An analysis of 32 matched patients (16 in each group) revealed that CD11b⁺ and CD54⁺ neutrophil levels of AKI were 1.74 folds (4.83×10⁹/L vs 2.77×10⁹/L, Z=-2.72, P<0.05) and 2.34 folds (3.32×10⁹/L vs 1.42×10⁹/L, Z=-4.12, P<0.05), respectively, of non-AKI at rewarming phase. [Conclusion] Neutrophils are activated during CPB, and they can be identified by CD11b/CD54 markers. The activated neutrophils of AKI patients are approximately 2 folds of non-AKI during the rewarming phase, with disparity reached peak between groups during rewarming. These findings suggest the removal of 50% of activated neutrophils during the rewarming phase may be effective to reduce the risk of AKI.

OBJECTIVES: To isolate potassium ion channel Kv4.1 inhibitor from centipede venom, and to determine its primary and spatial structure. METHODS: Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom, and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording. The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with MALDI-TOF, its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry, its patial structure was established based on iterative thread assembly refinement online analysis. RESULTS: A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8, and its primary sequence consists of 53 amino acid residues, showed as NH₂-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSGDSRLKD-OH. Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell, with 1.0 μmol/L SsTx-P2 suppressing 95% current of Kv4.1 channel. Its spatial structure showed that SsTx-P2 shared a conserved helical structure. CONCLUSIONS The study has isolated a novel peptide SsTx-P2 from centipede venom, which can potently inhibit the potassium ion channel Kv4.1, and its spatial structure displays a certain degree of conservation.

Objective: To investigate the relationship between total homocysteine (tHcy) levels and sarcopenia among the elderly, so as to provide insights into the prevention and treatment of sarcopenia. Methods: The elderly aged 65 years and older who participated in the physical examination of Shibantan Township Health Center in Xindu District, Chengdu City from April to June 2021 was selected as the study subjects. The elderly with sarcopenia (diagnosed according to the diagnostic criteria of the Asian Sarcopenia Working Group in 2019) and non-sarcopenia were matched 1︰1 by gender and age (±2 years). Demographic information, skeletal muscle mass, skeletal muscle strength and tHcy were collected through questionnaire surveys, physical examination and laboratory testing. Multivariable conditional logistic regression model was used to explore the relationship between tHcy and sarcopenia. Results: A total of 320 individuals, including 160 sarcopenia patients and 160 non-sarcopenia individuals, were investigated. There were 138 males (43.13%) and 182 females (56.87%), with a median age of 71.00 (interquartile range, 6.00) years. There were 57 drinkers (17.81%), 78 smokers (24.37%), 173 cases of hypertension (54.06%) and 124 cases of hyperhomocysteinemia (38.80%). Multivariable conditional logistic regression analysis showed that elevated tHcy was associated with an increased risk of sarcopenia (OR=1.107, 95%CI: 1.024-1.197), after adjusting for smoking, alcohol consumption, hypertension, waist circumference, neck circumference, body mass index, platelet count and high density lipoprotein cholesterol. Conclusion Elevated tHcy is associated with sarcopenia, and intervention should be carried out for the elderly with higher tHcy.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.