ObjectiveTo investigate the mechanism by which 2，3，5，4'-tetrahydroxyldiphenylethylene-2-O-glucoside （THSG） mitigates cerebral ischemia/reperfusion （CI/R） injury by regulating mitochondrial calcium overload and promoting mitophagy. MethodsSixty male SD rats were randomized into sham， model， SAS （40 mg·kg^-1）， and low-， medium- and high-dose （10， 20， 40 mg·kg^-1， respectively） THSG groups， with 10 rats in each group. The middle cerebral artery occlusion/reperfusion （MCAO/R） model was established by the modified Longa suture method. An oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed in PC12 cells. Neurological deficits were assessed via Zea Longa scoring， and cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Structural and functional changes of cortical neurons in MCAO/R rats were assessed by hematoxylin-eosin and Nissl staining. PC12 cell viability was detected by cell counting kit-8 （CCK-8） assay， and mitochondrial calcium levels were quantified by Rhod-2 AM. Immunofluorescence was used to detect co-localization of PTEN-induced kinase 1 （PINK1） and leucine zipper/EF-hand-containing transmembrane protein 1 （LETM1） in neurons. Transmission electron microscopy （TEM） was employed to observe mitochondrial morphology in neurons. Western blot was employed to analyze the expression of translocase of outer mitochondrial membrane 20 （TOMM20）， autophagy-associated protein p62， microtubule-associated protein light chain 3 （LC3）， cysteinyl aspartate-specific proteinase-9 （Caspase-9）， B-cell lymphoma 2-associated protein X （Bax）， and cytochrome C （Cyt C）. ResultsCompared with the sham group， the model group exhibited increased infarct volume （P<0.01） and neurological deficit scores （P<0.01）， neuronal structure was disrupted with reduced Nissl bodies. （P<0.01）， mitochondrial swelling/fragmentation， decreased PINK1/LETM1 co-localization （P<0.01）， upregulated protein levels of LC3Ⅱ/LC3Ⅰ， TOMM20， Caspase-9， Bax， and Cyt C （P<0.01）， downregulated protein level of p62 （P<0.05）， weakened PC12 viability （P<0.01）， and elevated mitochondrial calcium level （P<0.01）. Compared with the model group， THSG and SAS groups showed reduced infarct volumes （P<0.05，P<0.01） and neurological deficit scores （P<0.05，P<0.01）， mitigated mitochondrial damage， and increased PINK1/LETM1 co-localization （P<0.01）. Medium/high-dose THSG and SAS alleviated the neurological damage， increased Nissl bodies （P<0.05，P<0.01）， downregulated the protein levels of p62， TOMM20， Caspase-9， Bax， and Cyt C （P<0.05，P<0.01）， and elevated the LC3Ⅱ/LC3Ⅰ level （P<0.05，P<0.01）. High-dose THSG enhanced PC12 cell viability （P<0.01）， increased PINK1/LETM1 co-localization （P<0.01）， and reduced mitochondrial calcium （P<0.01）. ConclusionTHSG may exert the neuroprotective effect on CI/R injury by activating the PINK1-LETM1 signaling pathway， reducing the mitochondrial calcium overload， and promoting mitophagy.

ObjectiveTo investigate the mechanism by which 2，3，5，4'-tetrahydroxyldiphenylethylene-2-O-glucoside （THSG） mitigates cerebral ischemia/reperfusion （CI/R） injury by regulating mitochondrial calcium overload and promoting mitophagy. MethodsSixty male SD rats were randomized into sham， model， SAS （40 mg·kg^-1）， and low-， medium- and high-dose （10， 20， 40 mg·kg^-1， respectively） THSG groups， with 10 rats in each group. The middle cerebral artery occlusion/reperfusion （MCAO/R） model was established by the modified Longa suture method. An oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed in PC12 cells. Neurological deficits were assessed via Zea Longa scoring， and cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Structural and functional changes of cortical neurons in MCAO/R rats were assessed by hematoxylin-eosin and Nissl staining. PC12 cell viability was detected by cell counting kit-8 （CCK-8） assay， and mitochondrial calcium levels were quantified by Rhod-2 AM. Immunofluorescence was used to detect co-localization of PTEN-induced kinase 1 （PINK1） and leucine zipper/EF-hand-containing transmembrane protein 1 （LETM1） in neurons. Transmission electron microscopy （TEM） was employed to observe mitochondrial morphology in neurons. Western blot was employed to analyze the expression of translocase of outer mitochondrial membrane 20 （TOMM20）， autophagy-associated protein p62， microtubule-associated protein light chain 3 （LC3）， cysteinyl aspartate-specific proteinase-9 （Caspase-9）， B-cell lymphoma 2-associated protein X （Bax）， and cytochrome C （Cyt C）. ResultsCompared with the sham group， the model group exhibited increased infarct volume （P<0.01） and neurological deficit scores （P<0.01）， neuronal structure was disrupted with reduced Nissl bodies. （P<0.01）， mitochondrial swelling/fragmentation， decreased PINK1/LETM1 co-localization （P<0.01）， upregulated protein levels of LC3Ⅱ/LC3Ⅰ， TOMM20， Caspase-9， Bax， and Cyt C （P<0.01）， downregulated protein level of p62 （P<0.05）， weakened PC12 viability （P<0.01）， and elevated mitochondrial calcium level （P<0.01）. Compared with the model group， THSG and SAS groups showed reduced infarct volumes （P<0.05，P<0.01） and neurological deficit scores （P<0.05，P<0.01）， mitigated mitochondrial damage， and increased PINK1/LETM1 co-localization （P<0.01）. Medium/high-dose THSG and SAS alleviated the neurological damage， increased Nissl bodies （P<0.05，P<0.01）， downregulated the protein levels of p62， TOMM20， Caspase-9， Bax， and Cyt C （P<0.05，P<0.01）， and elevated the LC3Ⅱ/LC3Ⅰ level （P<0.05，P<0.01）. High-dose THSG enhanced PC12 cell viability （P<0.01）， increased PINK1/LETM1 co-localization （P<0.01）， and reduced mitochondrial calcium （P<0.01）. ConclusionTHSG may exert the neuroprotective effect on CI/R injury by activating the PINK1-LETM1 signaling pathway， reducing the mitochondrial calcium overload， and promoting mitophagy.

Background Chlorinated perfluoroalkyl ether sulfonate Cl-PFAES, trade name F-53B, a novel per- and polyfluoroalkyl substance (PFAS), has been shown to induce multi-organ toxicity in humans and cross the blood-brain barrier. However, its toxic effects and underlying mechanisms on neural stem cells (NSCs) remain unclear. Objective To investigate the impact of F-53B on NSCs proliferation and differentiation through oxidative stress and explore its potential molecular mechanisms in associations with mitochondrial function damage and the expression of autophagy-related gene (PINK1/Parkin). Methods Primary NSCs isolated from neonatal C57BL/6 mice were used as a model and exposed to F-53B at concentrations of 0, 33, or 100 μmol·L⁻¹ for 24 h. Cell viability was assessed using the cell counting kit-8 (CCK-8) assay, while proliferation was evaluated by the 5-ethynyl-2’-deoxyuridine (EdU) incorporation assay. Immunofluorescence staining was performed to observe differentiation phenotypes. Intracellular and mitochondrial reactive oxygen species (ROS) levels were quantified using dihydroethidium (DHE) and MitoSOX probes, respectively. Mitochondrial morphology was observed using MitoTracker Green. ATP level was measured with a commercial kit. Additionally, real-time quantitative polymerase chain reaction (qPCR) was conducted to quantify the expression of PINK1 and Parkin genes. Results Exposure to 100 μmol·L⁻¹ F-53B significantly reduced cell viability to 93.6% of the control group (P<0.01), and decreased the proportion of EdU⁺ cells (P<0.01), indicating proliferation inhibition. The differentiation analysis showed a reduction in neuronal generation, axonal shortening, and an increase in astrocytes. The 100 μmol·L⁻¹ F-53B exposure elevated intracellular ROS to 122% (P<0.01) and mitochondrial ROS (MitoROS) to 135% (P<0.001) of the control levels, leading to mitochondrial fragmentation. The ATP levels after the F-53B exposure decreased to 62.4% relative to the control group (P<0.001). Furthermore, the mRNA expression levels of PINK1 and Par after the F-53B exposure were notably reduced (P<0.05). Conclusion F-53B may induce oxidative stress, thereby disrupting mitochondrial morphology and function while inhibiting the PINK1/Parkin-mediated mitophagy pathway, ultimately leading to impaired neural stem cell proliferation and abnormal differentiation. This study provides new insights into the neurotoxicity mechanisms of F-53B.

Objective:To investigate the molecular characteristics and clinical heterogeneity of Usher syndrome（USH） -related gene variants in patients with hereditary hearing loss in southwest China, providing a basis for early diagnosis and clinical management. Methods:Thirteen patients from twelve families with hearing loss who attended the Affiliated Children's Hospital of Kunming Medical University between January 2017 and March 2021 were enrolled. All patients were identified as carrying USH-related gene variants through next-generation sequencing. Sanger sequencing was performed for all patients and their parents to validate the pathogenic variants. Comprehensive clinical evaluations, including medical history collection, otologic and ophthalmologic examinations, and vestibular function assessments, were conducted. Results:Among the 13 patients, 4 were diagnosed with USH type 1 and 2 with USH type 2. A total of 19 pathogenic or likely pathogenic variants were detected in USH-related genes, including MYO7A,CDH23,USH1C, and USH2A. The causative gene was MYO7A in 3 probands, CDH23 in 5, USH1C in 3, and USH2Ain 2. All patients exhibited an autosomal recessive inheritance pattern. Vestibular dysfunction was observed in 4 patients, and retinitis pigmentosa（RP） in 3 patients. Based on the genotype-phenotype correlation, 6 patients were initially diagnosed with USH, while 7 were classified as having non-syndromic hearing loss（NSHL）. Conclusion:This study revealed the clinical heterogeneity of USH-related gene variants in patients with hereditary deafness in southwest China. Although the clinical manifestations of USH are complex and there are overlapping characteristics between different subtypes, genetic testing provides an important basis for early diagnosis and precise clinical management. Especially for those with typical hearing loss, early genetic diagnosis can provide a window of time for early detection and intervention of retinitis pigmentosa.
Humans ; Usher Syndromes/genetics* ; Myosin VIIa ; Phenotype ; Male ; Female ; Myosins/genetics* ; Mutation ; Cadherins/genetics* ; Child ; Extracellular Matrix Proteins/genetics* ; Adolescent ; Pedigree ; High-Throughput Nucleotide Sequencing ; Cadherin Related Proteins ; Cytoskeletal Proteins ; Cell Cycle Proteins

Objective To develop the Children's Screen Interaction Quality Questionnaire(CSIQ)suit-able for measuring Chinese children aged 0 to 4 years,and to test its reliability and validity.Methods The purposive sampling method was used,and the guardians of 30 normal children aged 0 to 4 years undergoing physical examinations in the Department of Child Health Care of Guiyang Maternal and Child Health Care Hospital from February to April 2023 were selected as the interview objects.25 initial items were constructed through literature review,semi-structured interviews,and the Delphi expert consultation method.With the convenience sampling method,2 242 guardians of children aged 0 to 4 years old in the small and middle classes of 9 kindergartens in Guiyang City,Zunyi City,and Renhuai City were surveyed for item analysis,exploratory factor analysis,confirmatory factor analysis,and reliability and validity analysis.Results Exploratory factor a-nalysis extracted three factors,namely screen content interaction,reality interaction,and media interaction,with a total of 12 items.The cumulative variance explained rate of the 3-factor model was 69.829％.Confirma-tory factor analysis supported the three-factor model of CSIQ:x2/df=4.424,root mean square error of ap-proximation(RMSEA)=0.066,normed fit index(NFI)=0.955,comparative fit index(CFI)=0.965,incre-mental fit index(IFI)=0.965,Tucker-Lewis index(TLI)=0.955,goodness-of-fit index(GFI)=0.955,and the CSIQ had good convergent validity and discriminant validity.Conclusion The CSIQ has good reliability and validity.

Objective To analyze the main epidemiological characteristics of fungal infection in this hospital in the past 7 years,and to provide reference for clinical treatment and prevention and control strategies of fun-gal infection.Methods The fungal data and clinical data of related patients isolated from clinical samples in Peking Union Medical College Hospital from early January 2018 to the end of May 2024 were selected,and the main epidemiological characteristics of fungal infection in this hospital were identified and described through multi-angle statistical analysis.Results A total of 4 479 patients with filamentous fungal infection were en-rolled.The proportion of male patients[57.5％(2 576/4 479)]was higher than that of female patients[42.5％(1 903/4 143)],mainly distributed in internal medicine,Intensive Care Unit(ICU)and emergency de-partment,among which internal medicine accounted for the highest proportion[50.0％(2 241/4 479)].About 90.0％of the specimens were from the lower respiratory tract,in addition to specimens from skin and soft tis-sue,tissue,ear and blood culture.In terms of seasonal distribution,there are more patients in winter.The fun-gi were mainly composed of Aspergillus,Mucor,Cerdosporium,Fusarium and Penicillium,among which As-pergillus was the most abundant,accounting for 74.6％of the total.Aspergillus fumigatus was the most a-bundant Aspergillus,accounting for 42.5％of the total Aspergillus(1 418/3 340).Among the related infec-tions caused by mold,Aspergillus was the most common in the lower respiratory tract,accounting for 76.8％.Among them,Aspergillus fumigatus accounted for the highest proportion(33.6％).98.6％of the molds infected the ear were Aspergillus,of which Aspergillus niger and Aspergillus terreus were the most common.Skin infections are mainly caused by Sporothrix schenckii,Trichophyton rubrum,Microsporum ca-nis.The results of in vitro drug sensitivity test showed that the four common Aspergillus isolated in this hos-pital were sensitive to voriconazole,and amphotericin B had better antifungal activity against Mucorales in vitro.Conclusion Based on the main epidemiological characteristics of fungal infections in this hospital,it is recommended that special attention be paid to the admission of patients in the respiratory department during the peak infection period in autumn and winter.In the treatment of fungal infections in different regions and on different body parts,attention should be paid to the differences in the distribution of bacterial species.

ObjectiveTo investigate the mechanism of Baihuan Xiaoyao Decoction （Xiaoyaosan added with Lilii Bulbus and Albiziae Cortex） in alleviating depression-like behaviors of juvenile rats by regulating the polarization of microglia. MethodSixty juvenile SD rats were randomized into normal control， model， fluoxetine， and low-， medium-， and high-dose （5.36， 10.71， 21.42 g·kg^-1， respectively） Baihuan Xiaoyao decoction groups. The rat model of juvenile depression was established by chronic unpredictable mild stress （CUMS）. The sucrose preference test （SPT） was carried out to examine the sucrose preference of rats. Forced swimming test （FST） was carried out to measure the immobility time of rats. The open field test （OFT） was conducted to measure the total distance， the central distance， the number of horizontal crossings， and the frequency of rearing. Morris water maze （MWM） was used to measure the escape latency and the number of crossing the platform. The immunofluorescence assay was employed to detect the expression of inducible nitric oxide synthase （iNOS， the polarization marker of M1 microglia） and CD206 （the polarization marker of M2 microglia）. Real-time polymerase chain reaction was employed to determine the mRNA levels of iNOS， CD206， pro-inflammatory cytokines ［tumor necrosis factor （TNF）-α， interleukin （IL）-1β， and IL-6］ and anti-inflammatory cytokines （IL-4 and IL-10） in the hippocampus. Western blotting was employed to determine the protein levels of iNOS and CD206 in the hippocampus. The levels of IL-4 and IL-6 in the hippocampus were detected by enzyme-linked immunosorbent assay. ResultCompared with the normal control group， the model rats showed a reduction in sucrose preference （P<0.05）， an increase in immobility time （P<0.05）， decreased motor and exploratory behaviors （P<0.05）， and weakened learning and spatial memory （P<0.05）. In addition， the model rats showed up-regulated mRNA and protein levels of iNOS and mRNA levels of IL-1β， IL-6， and TNF-α （P<0.05）. Compared with the model group， Baihuan Xiaoyao decoction increased the sucrose preference value （P<0.05）， shortened the immobility time （P<0.01）， increased the motor and exploratory behaviors （P<0.05）， and improved the learning and spatial memory （P<0.01）. Furthermore， the decoction down-regulated the positive expression and protein level of iNOS， lowered the levels of TNF-α， IL-1β， and IL-6 （P<0.01）， promoted the positive expression of CD206， and elevated the levels of IL-4 and IL-10 （P<0.01） in the hippocampus of the high dose group. Moreover， the high-dose Baihuan Xiaoyao decoction group had higher sucrose preference value （P<0.01）， shorter immobility time （P<0.01）， longer central distance （P<0.01）， stronger learning and spatial memory （P<0.01）， higher positive expression and protein level of iNOS （P<0.01）， lower levels of TNF-α， IL-1β， and IL-6 （P<0.05， P<0.01）， lower positive expression and mRNA level of iNOS （P<0.05）， and higher levels of IL-4 and IL-10 （P<0.05， P<0.01） than the fluoxetine group. ConclusionBaihuan Xiaoyao decoction can improve the depression-like behavior of juvenile rats by inhibiting the M1 polarization and promoting the M2 polarization of microglia in the hippocampus.

Background Perfluorinated and polyfluoroalkyl substances (PFAS), a large group of emerging pollutants, are ubiquitous in the ecological environment. Their multiple organ toxic effects on human body are reported. Understanding the exposure level of PFAS in cord serum and associated influencing factors can provide scientific evidence for studying maternal and newborn health effects and risk regulation. Objective To explore the exposure levels of PFAS in cord serum and potential impact factors. Methods This study was based on the maternal and infant database and the cord serum sample bank of the Sheyang Mini Birth Cohort Study (SMBCS) established in 2009. A self-designed questionnaire was used to collect information on sociodemographic characteristics, living environment, and lifestyle of mothers during pregnancy. A total of 1097 cord serum samples were measured utilizing ultra-high performance liquid chromatography-Q-Exactive Orbitrap high-resolution mass spectrometry. Multiple linear regression models were used to identify influencing factors related to PFAS exposure level in cord serum. Results A total of 38 types of PFAS were detected in the cord serum samples, including 20 perfluorocarboxylic acids (PFCA), 14 perfluorosulfonic acids (PFSA), and 4 other types of PFAS. The detection rates of 14 PFAS compounds were above 50%. The detection rates of perfluoro-1-hexanesulfonic acid (PFHxS), perfluoro-1-octanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUdA) were in the range of 99.18%-100.00%. The median concentrations of PFOA and 6∶2 chlorinated polyfluorinated ether sulfonic acid (6∶2CI-PFESA) were higher than those of the other compounds, which were 3.76 µg·L⁻¹ and 2.61 µg·L⁻¹, respectively. The correlation coefficients among cord serum PFAS were in the wide range of 0.0911-0.8429 (P < 0.05). The associations between PFHxS and perfluoro-1-heptanesulfonic acid (PFHpS) (r=0.8429, P < 0.05), PFOS and PFHpS (r=0.7012, P < 0.05), and PFUdA and perfluorododecanoic acid (PFDoA) (r=0.7875, P < 0.05) were positive. The proportions of PFCA and PFSA in the cord serum samples were 60.1% and 38.4%, respectively. PFOA and 6∶2 Cl-PFESA were the predominant compounds in the cord serum samples, whose proportions were 37.8% and 19.3%, respectively. The concentrations of specific types of cord serum PFAS had varied associations with the following demographic variables of pregnant women: age, parity, education level, gestational age, and occupation. The multiple linear regression analysis found that the concentrations of 8 PFAS (PFHxS, PFHpS, PFNA, PFOS, PFDA, PFUdA, PFDoA, and 6∶2 CI-PFESA) in umbilical cord serum were lower in pregnant women aged 25 years and older than in those under the age of 25 years; compared to pregnant women with education levels at or below junior middle school, those with education levels at or above high school had lower concentrations of perfluoroheptanoic acid (PFHpA); the concentration of PFHpA in cord serum was negatively correlated with household annual income; multiparous women had higher concentrations of PFNA, PFUdA, and PFDoA than primiparous women; compared to mothers engaged in manual labor, the concentration of perfluoro-1-butanesulfonic acid (PFBS) in umbilical cord serum was lower in mothers engaged in mental labor, while the concentrations of PFBS and PFOA were lower and the concentrations of perfluorotridecanoic acid (PFTrDA) and 8∶2 chlorinated polyfluorinated ether sulfonic acid (8∶2CI-PFESA) were higher in mothers of other occupational types; the concentrations of umbilical cord serum PFOA, PFOS, PFUdA, and PFDoA were positively correlated with the gestational age of pregnant women, while N-methylperfluoro-1-octanesulfonamido acetic acid (N-MeFOSAA) was negatively correlated with the gestational age of pregnant women; PFTrDA was negatively correlated with the birth weight of newborns; compared with those with insufficient gestational weight gain, those with adequate gestational weight gain had lower PFDoA, while those with excess gestational weight gain had higher N-MeFOSAA. Conclusion PFAS compounds exposure is common in the mothers and infants in the study area. PFOA and 6∶2 CI-PFESA are the two main compounds in cord serum. Cord serum PFAS are associated with several demographic characteristics of the pregnant women. Future research needs to pay more attention to PFAS alternatives and other emerging contaminants.

Objective:To retrospectively analyze the treatment status of tyrosine kinase inhibitors (TKI) in newly diagnosed patients with chronic myeloid leukemia (CML) in China.Methods:Data of chronic phase (CP) and accelerated phase (AP) CML patients diagnosed from January 2006 to December 2022 from 77 centers, ≥18 years old, and receiving initial imatinib, nilotinib, dasatinib or flumatinib-therapy within 6 months after diagnosis in China with complete data were retrospectively interrogated. The choice of initial TKI, current TKI medications, treatment switch and reasons, treatment responses and outcomes as well as the variables associated with them were analyzed.Results:6 893 patients in CP ( n=6 453, 93.6%) or AP ( n=440, 6.4%) receiving initial imatinib ( n=4 906, 71.2%), nilotinib ( n=1 157, 16.8%), dasatinib ( n=298, 4.3%) or flumatinib ( n=532, 7.2%) -therapy. With the median follow-up of 43 ( IQR 22-75) months, 1 581 (22.9%) patients switched TKI due to resistance ( n=1 055, 15.3%), intolerance ( n=248, 3.6%), pursuit of better efficacy ( n=168, 2.4%), economic or other reasons ( n=110, 1.6%). The frequency of switching TKI in AP patients was significantly-higher than that in CP patients (44.1% vs 21.5%, P<0.001), and more AP patients switched TKI due to resistance than CP patients (75.3% vs 66.1%, P=0.011). Multi-variable analyses showed that male, lower HGB concentration and ELTS intermediate/high-risk cohort were associated with lower cytogenetic and molecular responses rate and poor outcomes in CP patients; higher WBC count and initial the second-generation TKI treatment, the higher response rates; Ph + ACA at diagnosis, poor PFS. However, Sokal intermediate/high-risk cohort was only significantly-associated with lower CCyR and MMR rates and the poor PFS. Lower HGB concentration and larger spleen size were significantly-associated with the lower cytogenetic and molecular response rates in AP patients; initial the second-generation TKI treatment, the higher treatment response rates; lower PLT count, higher blasts and Ph + ACA, poorer TFS; Ph + ACA, poorer OS. Conclusion:At present, the vast majority of newly-diagnosed CML-CP or AP patients could benefit from TKI treatment in the long term with the good treatment responses and survival outcomes.

Objective:To explore the locations of the lumbosacral nerve roots by use of the magnetic stimulation.Methods:Thirty healthy subjects were studied. The projections of the right L 2 to S 1 intervertebral foramina on their body surfaces were determined manually with ultrasound assistance. Magnetic stimulation was applied to different nerve root segments to induce compound muscle action potentials (CMAP) in the vastus medialis, tibialis anterior, and gastrocnemius muscles of the lower limbs. The changes in latency, amplitude, and motor threshold were observed. Results:Magnetic stimulation on the L 2-L 3 segment resulted in a significant direct excitation of the vastus medialis. That on the L 5-S 1 segment evoked a significant direct excitatory effect on the tibialis anterior and gastrocnemius, with a motor threshold below 40%, an amplitude exceeding 1mV, and many effective responses. However, during the magnetic stimulation on the L 4 segment, the amplitude of the vastus medialis was above 1mV, with no significant differences in the number of effective responses among the muscle groups. Moreover, there was a stepwise change in the latency of effective muscle responses to magnetic stimulation at different segments. The CMAP latencies of 12+ ms for the tibialis anterior and 13+ ms for the gastrocnemius indicated activation of the L 5 and L 4 nerve roots, respectively, while those of 6+ ms, 7+ ms, and 8+ ms for the vastus medialis suggested activation of the L 4, L 3, and L 2 nerve roots, respectively. Conclusions:Based on the responses (CMAP latency, amplitude and motor threshold) of the vastus medialis, tibialis anterior and gastrocnemius to magnetic stimulation at different L 2 to S 1 segments, the spinal nerve root segments responsible for innervation can be inferred.