1.Dynamic Interactions Between Hemispheres Reveal a Compensatory Pathway for Motor Recovery in Moderate-to-Severe Subcortical Stroke
Huaxin FAN ; Hewei WANG ; Zhengxu LIAN ; Qiurong YU ; Xinran WU ; Nanyu KUANG ; Benjamin BECKER ; Jianfeng FENG ; Mingxia FAN ; Lili SONG ; Limin SUN ; Jie ZHANG ; Craig S. ANDERSON
Journal of Stroke 2026;28(1):97-114
Background:
and Purpose Therapeutic target selection in noninvasive brain stimulation for poststroke motor recovery typically relies on the interhemispheric inhibition model, which is effective for mildly affected patients but offers limited benefits for severely affected individuals. The mechanisms governing recovery from moderate-to-severe stroke remain poorly understood, which hinders the development of targeted interventions.
Methods:
We analyzed resting-state functional magnetic resonance imaging data from patients with unilateral subcortical stroke and moderate-to-severe upper limb deficits, both pre- and postintervention, along with data from healthy controls. We developed a novel dynamic lag analysis method for identifying recovery-related homotopic sensorimotor regions with altered interhemispheric interactions. To further uncover the global reorganization pathway, we developed dynamic lateralization approaches to detect large-scale functional connectivity (FC) alterations associated with the identified regions in transient lateralization states.
Results:
Dynamic time-lag analysis revealed significantly reduced synchronized states in the homotopic dorsal premotor cortex (PMd) post-intervention compared with pre-intervention, which correlated with motor recovery. Further dynamic lateralization analysis revealed a prolonged segregation state in patients, characterized by weakened interhemispheric and strengthened intrahemispheric interactions. In this state, patients showed decreased FC in the ipsilesional PMd and increased FC in the contralesional PMd with bilateral subcortical networks. These recoveryrelated alterations were absent in the traditional static analysis.
Conclusions
Dynamic analyses targeting interhemispheric interactions are valuable for understanding neural reorganization after stroke. The diminished interactions between the homotopic PMd indicate a compensatory mechanism. Importantly, a state-dependent compensatory pathway was identified, wherein the contralesional PMd assumes the functions of the ipsilesional PMd through enhanced interactions with subcortical structures, potentially guiding more effective interventions.
2.Necroptosis in Exercise-induced Skeletal Muscle Damage: Roles and Regulatory Mechanisms
Zhi-Fei KE ; Wen-Jing SONG ; Yun-Feng DONG ; Hua-Yu SHANG
Progress in Biochemistry and Biophysics 2026;53(7):1884-1895
Exercise-induced muscle damage (EIMD) is a frequent form of skeletal muscle microdamage that occurs after high-intensity, prolonged, or unaccustomed exercise, especially exercise dominated by eccentric contractions. It is commonly characterized by delayed-onset muscle soreness, transient loss of muscle strength, local inflammation, structural disruption of myofibers, and delayed functional recovery. Although mild EIMD may serve as a stimulus for training adaptation, excessive or insufficiently recovered muscle damage can impair exercise performance, disturb training continuity, and reduce participation in physical activity. Therefore, clarifying the molecular mechanisms that underlie the initiation, amplification, and resolution of EIMD is important for optimizing athletic training, improving post-exercise recovery, and guiding evidence-based public fitness practice. Necroptosis is a regulated form of programmed cell death mediated primarily by the receptor-interacting protein kinase (RIPK) 1/RIPK3/mixed lineage kinase domain-like protein (MLKL) signaling axis. Recent studies have shown that necroptosis is closely involved in tissue injury, sterile inflammation, and repair remodeling. However, whether necroptosis acts as an initiating driver, a secondary damage amplifier, or an adaptive signal required for repair after EIMD remains unclear. This review aimed to summarize the potential role of necroptosis in EIMD and to establish a mechanistic framework linking regulated cell death, inflammatory amplification, immune regulation, and skeletal muscle repair. Relevant studies concerning EIMD, necroptosis, RIPK1/RIPK3/MLKL signaling, damage-associated molecular patterns (DAMPs), inflammatory responses, immune cell recruitment, extracellular matrix remodeling, and muscle regeneration were reviewed and integrated. On this basis, the possible temporal and functional involvement of necroptosis in different phases of EIMD was analyzed. The main evidence summarized in this review suggests that EIMD is not merely a consequence of primary mechanical disruption. Instead, it develops through a dynamic sequence that includes sarcolemmal instability, calcium overload, mitochondrial dysfunction, oxidative stress, inflammatory mediator production, immune cell infiltration, necrotic tissue clearance, and regeneration-associated remodeling. Necroptosis may participate in this process through at least two interconnected mechanisms. First, in the early or progressive phase of EIMD, activation of the RIPK1/RIPK3/MLKL signaling axis may promote MLKL phosphorylation and plasma membrane permeabilization, leading to the release of DAMPs such as high-mobility group box 1, ATP, mitochondrial DNA, and other intracellular components. These signals may activate innate immune pathways, amplify inflammatory cytokine production, and enhance the recruitment of neutrophils and macrophages, thereby aggravating secondary inflammation and extending muscle fiber injury. Second, during the resolution and repair phases, necroptosis-related signaling may also contribute indirectly to the formation of a regenerative microenvironment. By influencing the clearance of necrotic debris, the recruitment and phenotypic transition of immune cells, and the remodeling of extracellular matrix components, necroptosis may affect satellite cell activation, myogenic repair, and the eventual structural and functional recovery of injured skeletal muscle. Thus, the biological effect of necroptosis in EIMD may be context dependent rather than uniformly harmful. Its outcome may depend on exercise intensity, the extent of tissue damage, the timing of pathway activation, the involved cell types, inflammatory status, training background, age, and metabolic condition. In conclusion, necroptosis may represent an important molecular link between skeletal muscle injury, sterile inflammation, and tissue repair after damaging exercise. It may exert a dual role in EIMD by amplifying secondary damage while also contributing to repair coordination under appropriate temporal and microenvironmental conditions. Future studies should determine the activation pattern of RIPK1/RIPK3/MLKL signaling after different exercise protocols, identify the major cell populations undergoing necroptosis in injured skeletal muscle, and examine whether targeted modulation of necroptosis can reduce excessive inflammation without impairing necessary regenerative responses. This review provides a theoretical basis for understanding the pathogenesis of EIMD and for developing targeted strategies to improve skeletal muscle recovery after exercise-induced injury.
3.Retrospective study on adverse prognosis of neonates with late onset sepsis and invasive procedures in neonatal intensive care unit
Mengwen CHEN ; Chengyi FENG ; Jianfang WANG ; Ying LIU ; Hui WANG ; Haiying SONG ; Rongping ZHU ; Lin ZHANG ; Yu WANG ; Lijuan GAO ; Fang HE
Chinese Journal of Infection Control 2025;24(6):782-788
Objective To investigate the incidence and adverse prognosis of late onset sepsis(LOS)in neonates in neonatal intensive care unit(NICU).Methods A retrospective study was conducted to collect and analyze the peri-natal condition,underlying diseases,invasive procedures,and adverse prognosis of neonates in NICU of a regional maternal and child healthcare hospital from 2019 to 2023.According to whether LOS occurred during hospitaliza-tion,neonates were divided into LOS group and non-LOS group.The LOS group was divided into 5 subgroups based on whether invasive procedures were performed:LOS plus umbilical vein catheter(UVC)group,LOS plus peripherally inserted central catheter(PICC)group,LOS plus sequential catheter group,LOS plus tracheal intuba-tion group,and LOS plus lumbar puncture group,the relationship between LOS and adverse prognosis was ana-lyzed.Results Among 2 945 neonates in NICU,354(12.02%)developed LOS.Comparison between LOS groups and non-LOS group were as follows:in term of perinatal condition of neonates,there were statistically significant difference in weight,gestational age,and whether they were twins between the two groups(all P<0.001);in term of underlying diseases,there were statistically significant differences in the number of cases of maternal gestational hypertension,neonatal asphyxia,neonatal congenital heart disease,neonatal ventricular dilation,neonatal pneumo-nia,neonatal hyperthyrotropinemia,and neonatal anemia,as well as five invasive procedures between the two groups(all P<0.05).Compared with the non-LOS group,the incidences of retinopathy of prematurity(ROP),neonatal necrotizing enterocolitis(NNEC),bronchopulmonary dysplasia(BPD),and neonatal respiratory distress syndrome(NRDS)in LOS group were all higher(all P<0.001).Regression analysis showed that compared with the non-LOS groups,the risk of ROP increased in the LOS group and its subgroups,with the LOS plus sequential catheter group having a 2.27-fold higher risk of ROP than non-LOS group;the risk of NNEC increased in the LOS group and its subgroups,with the LOS plus UVC group having an 8.29-fold higher risk of NNEC than the non-LOS group.Except for the LOS plus UVC group,the risk of BPD increased in the LOS group and other subgroups,with the LOS plus PICC group and LOS plus sequential catheter group having 4.68-and 4.64-fold higher risk of BPD than the non-LOS group,respectively;the risk of NRDS in the LOS plus PICC group was 6.84-fold higher than the non-LOS group(all P<0.05).The top three pathogens causing LOS were coagulase negative Staphylococcus,Klebsiella pneumoniae,and Escherichia coli.Conclusion LOS can significantly increase the risks of ROP,NNEC,BPD,and NRDS.LOS plus invasive procedures can further increase the risk of adverse prognosis.
4.Design and Analysis of a Quantitative Dispensing Machine for Small Doses of Chinese Herbal Granules
Hengyuan ZHANG ; Kai SONG ; Yu JI ; Baotong DING ; Yiran FENG ; Jinshi LU
World Science and Technology-Modernization of Traditional Chinese Medicine 2025;27(9):2523-2535
To address the insufficiency of domestic small-dose Chinese herbal granule dispensing equipment,this study introduces the"black box method"design concept and,on this basis,designs a lightweight,compact and highly accurate dispensing device.This device uses a two-phase four-wire brushless motor to drive the slider for displacement,thereby controlling the volume of the medicine falling into the weighing device to complete the weighing of the medicine.Finally,a two-phase hybrid stepping motor is used to drive the weighing device to transfer the medicine.This paper first elaborates in detail on the mechanical structure and weighing dispensing principle of this device.Secondly,the ANSYS finite element software is used to conduct a force analysis test on the weighing device,and it is concluded that the deformation of the weighing device during the working process is 9.98×10-5 mm,and the maximum deformation of the discharge port is 6.65×10-5 mm.Finally,the ADAMS software is used to simulate and analyze the motion process of the mechanism.The results show that,under the premise of ensuring the accuracy of weighing,there are no virtual points or interference in the motion process.On this basis,a prototype test is conducted,and the error accuracy of the dispensing machine is about 0.066 g,which is higher than the traditional dispensing accuracy.This equipment has strong adaptability and high dispensing accuracy,providing a new solution for small-dose precise quantitative equipment.
5.68 Ga-DOTA-NOC PET/CT for diagnosing pheochromocytoma and paraganglioma
Zhenyu ZHAO ; Lulu ZHANG ; Xiaochen YAO ; Chuan ZHANG ; Fei YU ; Jieping SONG ; Xue XUE ; Guoqiang SHAO ; Feng WANG
Chinese Journal of Medical Imaging Technology 2025;41(2):268-272
Objective To observe the value of 68Ga-DOTA-NOC PET/CT for diagnosing pheochromocytoma(PCC)and paraganglioma(PGL).Methods Thirty-eight patients with suspected or confirmed PCC/PGL who underwent 68 Ga-DOTA-NOC PET/CT were retrospectively enrolled,among them 20 cases underwent 131I-metaiodobenzylguanidine(MIBG)SPECT/CT during the same period.The value of 68Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL at individual and lesion levels were analyzed and compared to the results of 131I-MIBG SPECT/CT.Results Among 38 cases,there were 20 cases of PCC,14 cases of PGL,1 case of adrenocortical carcinoma and 3 cases of benign adrenal hyperplasia.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of 68 Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL in all 38 cases was 87.88%(29/33),60.00%(3/5),93.55%(29/31),42.86%(3/7)and 84.21%(32/38),respectively.Totally 188 lesions were detected in 34 cases,with detection rate of 89.95%(188/209).For 20 patients who underwent both 2 kinds examinations,the detection rate of bone,lymph node,liver,lung metastases and the overall lesions of 68Ga-DOTA-NOC PET/CT were all higher than those of 131I-MIBG SPECT/CT(all P<0.05).No significant difference of diagnostic accuracy of PCC/PGL was found between 68 Ga-DOTA-NOC PET/CT and 131I-MIBG SPECT/CT(P>0.05).Conclusion The value of 68 Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL was comparable to that of 131I-MIBG SPECT/CT,but the former showed higher detection rate of metastases,hence being helpful to staging and risk stratification of PCC/PGL.
6.Retrospective study on adverse prognosis of neonates with late onset sepsis and invasive procedures in neonatal intensive care unit
Mengwen CHEN ; Chengyi FENG ; Jianfang WANG ; Ying LIU ; Hui WANG ; Haiying SONG ; Rongping ZHU ; Lin ZHANG ; Yu WANG ; Lijuan GAO ; Fang HE
Chinese Journal of Infection Control 2025;24(6):782-788
Objective To investigate the incidence and adverse prognosis of late onset sepsis(LOS)in neonates in neonatal intensive care unit(NICU).Methods A retrospective study was conducted to collect and analyze the peri-natal condition,underlying diseases,invasive procedures,and adverse prognosis of neonates in NICU of a regional maternal and child healthcare hospital from 2019 to 2023.According to whether LOS occurred during hospitaliza-tion,neonates were divided into LOS group and non-LOS group.The LOS group was divided into 5 subgroups based on whether invasive procedures were performed:LOS plus umbilical vein catheter(UVC)group,LOS plus peripherally inserted central catheter(PICC)group,LOS plus sequential catheter group,LOS plus tracheal intuba-tion group,and LOS plus lumbar puncture group,the relationship between LOS and adverse prognosis was ana-lyzed.Results Among 2 945 neonates in NICU,354(12.02%)developed LOS.Comparison between LOS groups and non-LOS group were as follows:in term of perinatal condition of neonates,there were statistically significant difference in weight,gestational age,and whether they were twins between the two groups(all P<0.001);in term of underlying diseases,there were statistically significant differences in the number of cases of maternal gestational hypertension,neonatal asphyxia,neonatal congenital heart disease,neonatal ventricular dilation,neonatal pneumo-nia,neonatal hyperthyrotropinemia,and neonatal anemia,as well as five invasive procedures between the two groups(all P<0.05).Compared with the non-LOS group,the incidences of retinopathy of prematurity(ROP),neonatal necrotizing enterocolitis(NNEC),bronchopulmonary dysplasia(BPD),and neonatal respiratory distress syndrome(NRDS)in LOS group were all higher(all P<0.001).Regression analysis showed that compared with the non-LOS groups,the risk of ROP increased in the LOS group and its subgroups,with the LOS plus sequential catheter group having a 2.27-fold higher risk of ROP than non-LOS group;the risk of NNEC increased in the LOS group and its subgroups,with the LOS plus UVC group having an 8.29-fold higher risk of NNEC than the non-LOS group.Except for the LOS plus UVC group,the risk of BPD increased in the LOS group and other subgroups,with the LOS plus PICC group and LOS plus sequential catheter group having 4.68-and 4.64-fold higher risk of BPD than the non-LOS group,respectively;the risk of NRDS in the LOS plus PICC group was 6.84-fold higher than the non-LOS group(all P<0.05).The top three pathogens causing LOS were coagulase negative Staphylococcus,Klebsiella pneumoniae,and Escherichia coli.Conclusion LOS can significantly increase the risks of ROP,NNEC,BPD,and NRDS.LOS plus invasive procedures can further increase the risk of adverse prognosis.
7.Comparative study of single-criteria and multi-criteria optimization modes for cervical cancer VMAT radiotherapy plans by Raystation planning system
Gang LI ; Yu-song LONG ; Jun-wen TAN ; Xian-tao HE ; Yong-fu FENG ; Zhan-yu WANG
Chinese Medical Equipment Journal 2025;46(9):39-44
Objective To carry out cervical cancer VMAT radiotherapy planning respectively with the single-criteria optimization(SCO)and multi-criteria optimization(MCO)modes of Raystation 4.7 planning system,and to provide references for selecting optimization mode clinically by comparing and analyzing the dosimetric parameters such as target dose distribution,exposure dose to organ at risk(OAR),monitor unit and beam-on time.Methods Ten cervical cancer patients who attended some hospital from February to December 2022 were retrospectively selected,and some VMAT plans were designed for them with the SCO mode of Raystation 4.7 planning system and then enrolled into a SCO group;other VMAT plans were redesigned with the MCO mode under the premise the setup conditions such as machine model and shot field angle were unchanged,and divided into a MCO group.The two groups were compared in terms of maximum dose(D2%),minimum dose(D98%),homogeneity index(HI)and conformity index(CI)of the planning target volume(PTV),beam-on time,monitor unit and exposure doses to OARs including bladder V50 Gy,V40 Gy and V30 Gy,rectum V50 Gy,V40 Gy and V30 Gy,small intestine V50 Gy,V40 Gy and V30 Gy and left and right femur V50 Gy,V40 Gy and V30 Gy.SPSS 22.0 software was used for statistical analysis.Results Both the two groups met clinical requirements.There were no significant differences between the two groups in D98%,CI,small intestine V50 Gy and left and right femur V40 Gy(P>0.05).The MCO group had the values of HI,D2%,V50 Gy,V40 Gy and V30 Gy,rectum V50 Gy,V40 Gy and V30 Gy,small intestine V40 Gy and V30 Gy and left and right femur V30 Gy lower than those of the SCO group,with the differences being statistically significant(P<0.05).The SCO group had less monitor units and shorter beam-on time when compared with the MCO group,with the differences being statistically siginificant(P<0.05).Conclusion When compared with the SCO mode-based VMAT plans,the MCO mode-based VMAT plans significantly decrease the exposure doses and volume to rectum,bladder and small intestine and raise the PTV homogeneity,while lower the treatment efficiency to some extent by increased monitor units and prolonged beam-on time.[Chinese Medical Equipment Journal,2025,46(9):39-44]
8.Comparative study of single-criteria and multi-criteria optimization modes for cervical cancer VMAT radiotherapy plans by Raystation planning system
Gang LI ; Yu-song LONG ; Jun-wen TAN ; Xian-tao HE ; Yong-fu FENG ; Zhan-yu WANG
Chinese Medical Equipment Journal 2025;46(9):39-44
Objective To carry out cervical cancer VMAT radiotherapy planning respectively with the single-criteria optimization(SCO)and multi-criteria optimization(MCO)modes of Raystation 4.7 planning system,and to provide references for selecting optimization mode clinically by comparing and analyzing the dosimetric parameters such as target dose distribution,exposure dose to organ at risk(OAR),monitor unit and beam-on time.Methods Ten cervical cancer patients who attended some hospital from February to December 2022 were retrospectively selected,and some VMAT plans were designed for them with the SCO mode of Raystation 4.7 planning system and then enrolled into a SCO group;other VMAT plans were redesigned with the MCO mode under the premise the setup conditions such as machine model and shot field angle were unchanged,and divided into a MCO group.The two groups were compared in terms of maximum dose(D2%),minimum dose(D98%),homogeneity index(HI)and conformity index(CI)of the planning target volume(PTV),beam-on time,monitor unit and exposure doses to OARs including bladder V50 Gy,V40 Gy and V30 Gy,rectum V50 Gy,V40 Gy and V30 Gy,small intestine V50 Gy,V40 Gy and V30 Gy and left and right femur V50 Gy,V40 Gy and V30 Gy.SPSS 22.0 software was used for statistical analysis.Results Both the two groups met clinical requirements.There were no significant differences between the two groups in D98%,CI,small intestine V50 Gy and left and right femur V40 Gy(P>0.05).The MCO group had the values of HI,D2%,V50 Gy,V40 Gy and V30 Gy,rectum V50 Gy,V40 Gy and V30 Gy,small intestine V40 Gy and V30 Gy and left and right femur V30 Gy lower than those of the SCO group,with the differences being statistically significant(P<0.05).The SCO group had less monitor units and shorter beam-on time when compared with the MCO group,with the differences being statistically siginificant(P<0.05).Conclusion When compared with the SCO mode-based VMAT plans,the MCO mode-based VMAT plans significantly decrease the exposure doses and volume to rectum,bladder and small intestine and raise the PTV homogeneity,while lower the treatment efficiency to some extent by increased monitor units and prolonged beam-on time.[Chinese Medical Equipment Journal,2025,46(9):39-44]
9.Application of metagenomics next-generation sequencing of pathogen in patients with pneumonia-induced sepsis
Feixiang XU ; Feng YU ; Ruilan WANG ; Zhenju SONG ; Chaoyang TONG ; Changqing ZHU
Journal of Shanghai Jiaotong University(Medical Science) 2025;45(2):169-178
Objective·To explore the diagnostic,therapeutic,and prognostic value of metagenomics next-generation sequencing(mNGS)in patients with pneumonia-induced sepsis.Methods·This study consisted of a multicenter,prospective,non-randomized controlled trial and a diagnostic test.Patients with pneumonia-induced sepsis who were hospitalized in four hospitals across China were enrolled between March 2020 and October 2021.All patients met the Sepsis-3 criteria issued by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine,as well as the clinical diagnostic standard of pneumonia.Enrolled patients were assigned based on their preference to either the conventional test-only group[receiving only conventional test(CMT)]or the combined mNGS test group(receiving CMT and mNGS concurrently).The primary outcome was the 7-day all-cause mortality rate,and secondary outcomes included the changes in SOFA and APACHE Ⅱ scores from baseline to day 7,28-day all-cause mortality rate,the composite endpoint of mechanical ventilation or death within 28 d,28 d ventilation-free days,28 d hospital-free days,and the average daily hospitalization cost.Propensity score matching was used to balance covariates between the two groups.Kaplan-Meier curves were plotted and Cox proportional hazards models were built to compare the risk of death between the two groups.Pathogen detection results from infection site samples in the combined mNGS test group were used for the diagnostic test.The clinically-adjudicated causative pathogens was used as the reference standard.The results of traditional pathogen detection and mNGS detection were compared respectively with the reference standard.The positive percent agreement,negative percent agreement,positive predictive value,and negative predictive value between the two methods and the reference standard were calculated.McNemar's χ2 test was used to evaluate the causative pathogen detection capabilities of the two methods.Results·A total of 533 patients were enrolled,of whom 311 opted for additional mNGS testing,while 222 received only conventional pathogenetic testing.In the non-randomized controlled trial,after propensity score matching to balance covariates,the 7-day all-cause mortality was lower in the combined mNGS test group compared to the conventional test-only group[4.8%vs 8.6%,HR 0.37(95%CI 0.15?0.91),P=0.031].Additionally,the 28-day ventilation-free days were increased in the combined mNGS test group(19.9 d vs 18.4 d,P=0.041).No significant difference was observed between the two groups in terms of 28-day all-cause mortality or the average daily hospitalization costs.In the diagnostic test,compared to the reference standard,the positive percent agreement of mNGS with the clinical composite judgment for causative pathogens was higher than that of CMT[91.9%(95%CI 87.7%?95.0%)vs 56.1%(95%CI 49.7%?62.4%),P<0.001].Conversely,the negative percent agreement of mNGS was lower than that of CMT[29.2%(95%CI 18.6%?41.8%)vs 69.2%95%CI 56.6%?80.1%),P<0.001].The negative predictive value of nNGS was higher than that of CMT[48.7%(95%CI 32.4%?65.2%)vs 29.4%(95%CI 22.3%?37.3%),P=0.001].Conclusion·In patients with pneumonia-induced sepsis,mNGS of infection site samples demonstrated a higher detection rate of causative pathogen compared to CMT.Furthermore,the combination of mNGS with CMT may help reduce the 7-day all-cause mortality,suggesting that mNGS has clinical value and potential for application in the management of sepsis caused by pulmonary infections.
10.Effects of fangchinoline derivative LYY-32 on biological properties of BLM DNA helicase
Wang-ming ZHANG ; Qin-ying FENG ; Xiao-yu SONG ; Xin-zhong ZHOU ; Juan LU ; Wan-qing XIE ; Zhi-wen LAI ; Wei-dong PAN ; Jie-lin LIU
Chinese Pharmacological Bulletin 2025;41(9):1680-1686
Aim To investigate the effects of the fangchinoline derivative LYY-32 on the biological prop-erties of the BLM642-1290 DNA helicase,in order to lay a foundation for further research on its antitumor activity.Methods Fluorescence polarization assay,malachite green-phosphate and ammonium molybdate colorime-try,and fluorescein-labeled DNA gel electrophoresis experiments were conducted to study the effects of fangchinoline derivative LYY-32 on the DNA binding activity,ATPase activity,and DNA unwinding activity of BLM642-1290 DNA helicase.The effects of LYY-32 on the DNA unwinding activity of DNA helicase in cells were studied using fluorescent techniques and time-lapse microscopy.Ultraviolet spectral scanning was used to investigate the effects of LYY-32 on the confor-mation of the BLM642-1290 DNA helicase.Results At a concentration of 10 μmol·L-1,the inhibition rate of LYY-32 on BLM642-1290 DNA helicase binding to dsDNA was 53.17%.At a concentration of 5 μmol·L-1,the inhibition rate of LYY-32 on BLM642-1290 DNA helicase binding to ssDNA was 88.49%.The inhibition rate of LYY-32 on the ATPase activity of BLM642-1290 DNA he-licase was 89.3%at a concentration of 50 μmol·L-1.When the concentration of LYY-32 exceeded 5μmol·L-1,its inhibition rate on the DNA unwinding activity of BLM642-1290 DNA helicase was 100%.LYY-32 also significantly inhibited the DNA unwinding ac-tivity of DNA helicase in cells.However,LYY-32 had no effect on the conformation of BLM642-1290 DNA heli-case.Conclusion The DNA binding activity,AT-Pase activity,and DNA unwinding activity of BLM642-1290 DNA helicase could be significantly inhibi-ted by the fangchinoline derivative LYY-32.

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