Melatonin (Mel) has been shown to have cardioprotective effects, but its action on ion channels is unclear. In this experiment, we investigated the inhibitory effect of Mel on late sodium currents (I_Na.L) in mouse ventricular myocytes and the anti-arrhythmic effect at the organ level as well as its mechanism. The whole-cell patch clamp technique was applied to record the ionic currents and action potential (AP) in mouse ventricular myocytes while the electrocardiogram (ECG) and monophasic action potential (MAP) were recorded simultaneously in mouse hearts using a multichannel acquisition and analysis system. The results demonstrated that the half maximal inhibitory concentration (IC₅₀) values of Mel on transient sodium current (I_Na.T) and specific I_Na.L opener 2 nmol·L^-1 sea anemone toxins II (ATX II) increased I_Na.L were 686.615 and 7.37 μmol·L^-1, respectively. Mel did not affect L-type calcium current (I_Ca.L), transient outward current (I_to), and AP. In addition, 16 μmol·L^-1 Mel shortened ATX II-prolonged action potential duration (APD), suppressed ATX II-induced early afterdepolarizations (EADs), and significantly reduced the incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) in Langendorff-perfused mouse hearts. In conclusion, Mel exerted its antiarrhythmic effects principally by blocking I_Na.L, thus providing a significant theoretical basis for new clinical applications of Mel. Animal welfare and experimental process are in accordance with the regulations of the Experimental Animal Ethics Committee of Wuhan University of Science and Technology (2023130).

Objective To elucidate the effect of curcumol on hepatic stellate cell iron death and epithelial-mesenchymal transition(EMT),and to investigate the molecular mechanism of its anti-liver fibrosis effect.Methods A model of hepatic stellate cell activation was constructed using normal cultured hepatic stellate cells in vitro,and the cells were divided into blank group and experimental-L,-M,-H groups.The blank group was given DMEM complete culture solution for normal culture;the experimental-L,-M,-H groups were given DMEM complete culture solution containing 12.5,25.0 and 50.0 mg·L-1 curcumol for 48 h of intervention.The effects of curcumol on the proliferation of hepatic stellate cells was observed by CCK-8.The expression levels of glutathione peroxidase 4(GPX4)and solute carrier family 7 member 11(SLC7A11)were detected by Western blot.The expression levels of E-cadherin and N-cadherin were detected by immunofluorescence.Results The cell proliferation rates of the experimental-M,-H groups and blank group were(68.97±5.61)％,(61.91±4.40)％and(118.07±10.01)％;the relative expression levels of GPX4 were 0.37±0.04,0.28±0.03 and 0.58±0.05;the relative expression levels of SLC7A11 were 0.38±0.04,0.28±0.03 and 0.60±0.05;E-cadherin levels were 6.76±1.09,9.57±1.73 and 2.05±0.72;N-cadherin levels were 5.66±0.66,3.44±0.78 and 10.37±0.66.The differences of above indicators were statistically significant between the blank group and the experimental-M,-H groups(P＜0.05,P＜0.01).Conclusion Curcumol promotes iron death in hepatic stellate cells,thereby inhibiting hepatic stellate cell EMT,which may be its molecular mechanism to prevent and treat liver fibrosis.

Objective To investigate the predictive value of new simplified insulin resistance(IR)assessment indexes in identifying subclinical left ventricular systolic function impairment in patients with type 2 diabetes mellitus(T2DM).Methods A total of 150 T2DM patients with preserved left ventricular ejection fraction(LVEF≥50%)who were admitted to Department of Endocrinology of the First Affiliated Hospital of Air Force Medical University from June 2021 to December 2021 were retrospectively analyzed.All patients underwent two-dimensional speckle tracking echocardiography to measure left ventricular global longitudinal strain(GLS).According to GLS value,the subjects were divided into the normal group(GLS≥18%group,n=80)and the impaired group(GLS<18%group,n=70).Some new simplified IR assessment indicators were calculated and compared between the two groups,including body mass index(BMI),TG/HDL-C ratio,triglyceride-glucose(TyG)index,TyG-BMI index,TyG-WHR and metabolic score for IR(METS-IR).Correlation between the GLS and the new simplified IR assessment indexes was analyzed.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of different simplified IR assessment indexes,with the area under the curve(AUC)calculated.Furthermore,according to whether the subjects were complicated with hypertension,binary logistics regression analysis was performed to explore the independent correlation between the simplified IR assessment index and GLS<18%.Results Total 150 were included with aged(54.5±13.7)years with 96(64.0%)men and 54(36.0%)women.Compared with the GLS≥18%group,the TG/HDL-C ratio,TyG index,TyG-BMI,and METS-IR of subjects in the GLS<18%group were significantly increased(P<0.05).Pearson correlation analysis showed that TG/HDL-C ratio,TyG index,TyG-BMI,TyG-WHR,and METS-IR were negatively correlated with GLS(P<0.05).ROC analysis showed that TyG index had a certain predictive value for the evaluation of GLS<18%(AUC=0.678,95%CI 0.591-0.765,P<0.001).Stratification based on hypertension and further adjusting for confounding factors,TyG index remains significantly associated with GLS<18%(OR=3.249,95%CI 1.045-10.103,P=0.042).Conclusions The novel simplified insulin resistance evaluation indexes are closely associated with left ventricular subclinical systolic dysfunction in T2DM patients with preserved ejection fraction.TyG index is an effective index to identify left ventricular subclinical dysfunction in these populations.

Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.

Objective To explore the effects of different test positions on quantitative muscle strength of wrist and finger flexor muscle groups and to establish a standardized muscle strength test protocol for each muscle group.Methods Forty healthy subjects (12 males and 28 females) were recruited.A portable digital quantitative muscle strength tester,Micro FET2TM,was used to measure the flexor muscle strength of each finger and the wrist joint at the 30° extension,0° neutral,and 30° flexion,respectively.Palmar abduction strength of the thumb was measured at 30° and 60°,respectively.Ten subjects were randomly selected from the 40 subjects,and the quantitative muscle strength of each muscle group was tested again by the same operator after an interval of 10 to 15 days.Results Except for the fact that in males,there was no significant difference in flexor muscle strength of thumb and wrist joint between 30° of wrist extension and neutral 0° position,the muscle strength of the other fingers flexion and wrist palmar flexor showed the following characteristics:30° of wrist extension>neutral 0° posi-tion>30° of flexion,and the PAST was 30°>60°;The flexor muscle strength of all the subjects was thumb>index finger>middle finger>ring finger>little finger;All muscle strength values of male were greater than those of female,and the difference was statistically significant (P<0.05);There was no significant difference between the left and right side muscle strength values of all subjects (P>0.05).The reliability of muscle strength values measured at different times in 10 subjects was good.Conclu-sion The quantitative muscle strength of each muscle group of the hand and wrist is affected by the test position,and a standardized and uniformed test position should be adopted in the actual identification.Micro FET2TM has good reliability for hand and wrist quantitative muscle strength testing.The 30° ex-tension of the wrist can be used as the best standardized test position for the flexion muscle strength of each finger and wrist joint.The 30° position can be used as the best standardized test position for PAST.

Further evidence is needed to explore the impact of high-altitude environments on the neurologic function of neonates.Non-invasive techniques such as cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography can provide data on cerebral oxygenation and brain electrical activity.This study will conduct multiple cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography monitoring sessions at various time points within the first 3 days postpartum for healthy full-term neonates at different altitudes.The obtained data on cerebral oxygenation and brain electrical activity will be compared between different altitudes,and corresponding reference ranges will be established.The study involves 6 participating centers in the Chinese High Altitude Neonatal Medicine Alliance,with altitude gradients divided into 4 categories:800 m,1 900 m,2 400 m,and 3 500 m,with an anticipated sample size of 170 neonates per altitude gradient.This multicenter prospective cohort study aims to provide evidence supporting the impact of high-altitude environments on early brain function and metabolism in neonates.[Chinese Journal of Contemporary Pediatrics,2024,26(4):403-409]

Objective To explore the application value of multimodal monitoring in postoperative evaluation of neurointerventional surgery in patients with acute ischemic stroke.Method A total of 86 patients with acute ischemic stroke who received neurointerventional surgery in the Neurointensive Care Unit of Department of Neurology in Tangshan People's Hospital from December 2021 to December 2022 were selected,and they were randomly divided into the routine group and the multimodal group by 1∶1 ratio,with 43 cases in each group.Patients in the routine group were routinely monitored.Patients in the multimodal group were given non-invasive intracranial pressure monitoring,transcranial Doppler monitoring and electroencephalogram monitoring on the basis of routine monitoring,and the corresponding treatments were adjusted according to the monitoring results.The National Institute of health stroke scale(NIHSS)was used to evaluate the improvement of neurological deficits of patients,and the modified Rankin scale(mRS)score was used to evaluate the 90-day prognosis of patients.The incidence of intracranial hemorrhage within 24 hours,symptomatic intracranial hemorrhage within 24 hours,decompressive craniectomy surgery,and the mortality were recorded to evaluate the prognosis.Results There was no statistically significant difference in age,gender,hypertension history,diabetes history,atrial fibrillation history,smoking history,NIHSS score at admission,mRS score at admission,intravenous thrombolysis ratio,time from onset to vascular opening,postoperative blood flow classification,occlusion site,and TOAST classification of patients between the two groups(P>0.05).The 90-day mRS score of patients in the multimodal group was significantly lower than that in the routine group(P<0.05);The proportion of patients with 90-day mRS score of 4 to 6 points in the multimodal group was significantly lower than that in the routine group(P<0.05);The improvement of NIHSS score from baseline to 14 days of patients in the multimodal group was significantly better than that in the routine group(P<0.05).There was no statistically significant difference in the incidence of intracranial hemorrhage within 24 hours,symptomatic intracranial hemorrhage within 24 hours,decompressive craniectomy surgery,and the 90-day mortality between the two groups(P>0.05).Spearman correlation analysis showed that 90-day mRS score was positively correlated with the change of NIHSS score from baseline to 14 days(r=0.419,P<0.05).Conclusion Multimodal monitoring of patients with acute ischemic stroke undergoing neurointervention surgery,combined with multimodal monitoring indicators to guide clinical individualized treatment can improve the neurological prognosis of patients,reduce the incidence of complications and mortality.

Objective:To explore the effect of UV radiation resistance-associated gene(UVRAG)on ferroptosis induced by sorafenib in leukemia K562 cells.Methods:K562 cells were treated with 0,0.625,1.25,2.5,5,10,and 20μmol/L sorafenib for 24 or 48 hours,and the cell viability was detected by CCK-8 assay.Flow cytometry technology was used to detect the changes of reactive oxygen species(ROS)in K562 cells treated with 0,5,and 10 μmol/L sorafenib for 24 hours.Western blot was used to detect the protein expression of GPX4 in K562 cells treated with 0,5,and 10μmol/L sorafenib and pretreatment with ferroptosis inhibitor.A recombinant lentiviral vector was used to construct UVRAG overexpression cell line in K562 cells.qPCR and Western blot were used to verify UVRAG gene overexpression,and Western blot detected the effect of UVRAG on the protein expression of GPX4 and HMGB1 after treatment with sorafenib.Results:Different concentrations of sorafenib could significantly inhibit the proliferation of K562 cells,and the cell viability gradually decreased with the increase of concentration(r24h=-0.9841,r48 h=-0.9970).The level of ROS was increased(When the concentration was 10 μmol/L,P＜0.00 1),while the expression of GPX4 protein was decreased in the process of 0,5,10 μmol/L sorafenib-induced K562 cell death(P＜0.05),and the decrease in GPX4 protein could be partially reversed by pretreatment with ferroptosis inhibitor(P＜0.05).Compared with NC group and NC-Sorafenib group,the expression of GPX4 protein was significantly decreased(both P＜0.05),while HMGB1 protein was significantly increased(both P＜0.05).Conclusion:Sorafenib can induce ferroptosis in K562 cells,and this process can be promoted by UVRAG.

Rheumatoid arthritis (RA) is an autoimmune disease driven by antigens and mediated by T cells. Collagen II (CII) and fibrinogen (Fib) are the two main antigens in the pathogenesis of RA. The antigen produced after citrulline modification (Cit) is also one of the inducements to induce the body to produce a pathogenic anti-citrulline protein antibody (ACPA). To provide a reference for RA-related research, this study intends to establish an RA animal model by using CII, Cit-CII, Fib, and Cit-Fib antigens, emulsification with complete Freund's adjuvant and immunization with DBA/1 mice, respectively, to compare the pathological characteristics of RA models induced by different antigens from the aspects of pathology, imaging and serum biochemistry. Animal welfare and experimental process are in accordance with the regulations of the Experimental Animal Ethics Committee of the China Academy of Chinese Medical Sciences. The results showed that the CII, Cit-CII, and Cit-Fib induced mice all had symptoms such as joint redness and swelling, and toe deformation and the clinical score and incidence rate were higher than those of the normal group. The CII group had the most serious lesions, with a incidence rate of 100%, and the Cit-CII and Cit-Fib groups had mild symptoms, with a incidence rate of 25% and 37.5%, respectively; pathological and imaging examination results showed that the joints of mice in CII-induced group showed severe synovial inflammation, cartilage and bone destruction, while those in Cit-CII and Cit-Fib group showed only slight inflammatory infiltration, joint cavity stenosis and bone destruction; the results of serum antibody detection showed that CII, Cit-CII and Cit-Fib groups all produced high levels of anti-cyclic citrullinated peptide (CCP) antibodies, among which, Cit-Fib group > Cit-CII group > CII group > Fib group, and both Cit-CII and Cit-Fib groups produced high levels of citrullinated epitope-specific antibodies, while the total IgG level was the highest in CII group; serum ELISA and RT-PCR analysis of joint tissue showed that the expression of pro-inflammatory factors and bone destruction-related molecules increased most significantly in the CII-induced group, followed by Cit-Fib and Cit-CII. The above results showed that among the four different antigens, the symptoms and conditions of arthritis in RA mice induced by CII were the most serious, and IgG instead of anti-CCP antibody was its typical immunological feature, and CII could be the first choice for the model of RA mice; Cit-Fib has certain immunogenicity, can partially induce the symptoms and conditions of RA arthritis in mice, and produce high-level anti-CCP antibody and anti-Cit-Fib antibody, which is more suitable for the study of citrulline-related RA; although Cit-CII has certain immunogenicity, the incidence, and severity of RA arthritis induced by Cit-CII in mice are low.

OBJECTIVE: The study aimed to estimate the benchmark dose (BMD) of coke oven emissions (COEs) exposure based on mitochondrial damage with the mitochondrial DNA copy number (mtDNAcn) as a biomarker. METHODS: A total of 782 subjects were recruited, including 238 controls and 544 exposed workers. The mtDNAcn of peripheral leukocytes was detected through the real-time fluorescence-based quantitative polymerase chain reaction. Three BMD approaches were used to calculate the BMD of COEs exposure based on the mitochondrial damage and its 95% confidence lower limit (BMDL). RESULTS: The mtDNAcn of the exposure group was lower than that of the control group (0.60 ± 0.29 vs. 1.03 ± 0.31; P < 0.001). A dose-response relationship was shown between the mtDNAcn damage and COEs. Using the Benchmark Dose Software, the occupational exposure limits (OELs) for COEs exposure in males was 0.00190 mg/m ³. The OELs for COEs exposure using the BBMD were 0.00170 mg/m ³ for the total population, 0.00158 mg/m ³ for males, and 0.00174 mg/m ³ for females. In possible risk obtained from animal studies (PROAST), the OELs of the total population, males, and females were 0.00184, 0.00178, and 0.00192 mg/m ³, respectively. CONCLUSION Based on our conservative estimate, the BMDL of mitochondrial damage caused by COEs is 0.002 mg/m ³. This value will provide a benchmark for determining possible OELs.
Male ; Female ; Animals ; Coke ; Polycyclic Aromatic Hydrocarbons ; DNA Copy Number Variations ; Benchmarking ; Occupational Exposure/analysis* ; DNA, Mitochondrial/genetics* ; DNA Damage