Objective:To analyze the genetic characteristics of the VWF gene c.7332G＞A nonsense mutation and explore its molecular pathogenesis.Methods:Phenotypic diagnosis of the proband was performed using VWF:Ag,VWF:RCo,FⅧ:C and multimeric analysis.The probands were genotyped by NGS whole-exome sequencing,and the sequencing results were validated by sanger sequencing.The family members were genotyped by Sanger sequencing.The VWF gene c.7332G＞A nonsense mutant plasmid was constructed.After transfection,the function of VWF gene c.7332G＞A mutant plasmid was verified at cell level in vitro.The mRNA level was detected by qRT-PCR,and the expression level of protein was detected by Western blot,the function of multimerization was verified by the multimeric analysis.Results:VWF:Ag and VWF:RCo were all less than 3％in the proband,and the multimeric analysis showed multimer deficiency.The proband was diagnosed as type 3 VWD.The homozygous nonsense mutation of VWF gene c.7332G＞A was detected by gene sequencing.The VWF mRNA level of the mutant plasmid was decreased,and the VWF protein expression in the cell supernatant was decreased,the mutant protein was truncated and the function of VWF multimerization was impaired.Conclusion:A homozygous mutation in exon 43 of VWF gene,c.7332G＞A,was responsible for the probands type 3 VWD in the proband.The mutation caused a decrease in the relative level of VWF mRNA and protein,and impaired the function of VWF multimerization.

BACKGROUND:Currently,research both domestically and internationally on patellofemoral pain syndrome has explored the kinematics and dynamics during daily activities such as stair ascent and descent,and walking. However,there is a lack of studies examining the lower limb biomechanical characteristics of young female patients with patellofemoral pain syndrome in different squatting conditions.OBJECTIVE:To investigate the lower limb biomechanical characteristics among young female patients with patellofemoral pain syndrome in different functional states of the subtalar joint,providing theoretical support for the clinical treatment of various types of patellofemoral pain syndrome.METHODS:A total of 33 participants were included in this study. There were 10 subjects in the healthy control group (group C). The other 27 subjects with patellofemoral pain syndrome were divided into two groups according to the foot posture index:14 subjects in the normal subtalar joint group (group A,foot posture index 0-6 points) and 13 subjects in the abnormal subtalar joint group (group B,foot posture index 7-12 points). The biomechanical indices of thesubjects in each group were collected and compared when they walked on stairs at normal speed. The kinematic indices included the three-dimensional joint angles of the hip and knee and the sagittal plane joint angles of the ankle at the initial contact moment and the moment of maximum knee flexion angle during the stance period. The dynamic indices included the three-dimensional joint torques of the hip and knee and the sagittal plane joint torques of the ankle at the moment of maximum knee flexion angle during the stance period. The surface electromyography indices included the root mean square amplitudes of the vastus medialis,vastus lateralis,rectus femoris,semitendinosus and semimembranosus,biceps femoris,and gluteus medius in the pre-activation stage and the buffering stage.RESULTS AND CONCLUSION:(1) At the initial ground contact moment,group A exhibited a greater knee flexion angle (P<0.05),greater hip external rotation angle (P<0.01),and smaller knee external rotation angle (P<0.01) compared to group B. Compared to group C,group A showed a greater knee flexion angle and smaller hip flexion angle (both P<0.01). Group B demonstrated a greater knee external rotation angle and smaller hip external rotation angle and hip flexion angle (all P<0.01) compared to group C. (2) At the moment of maximum knee flexion,group A had a smaller knee valgus angle (P<0.05),smaller knee external rotation angle (P<0.05),and greater knee flexion angle (P<0.01) compared to group B. Compared to group C,group A showed a smaller knee valgus angle (P<0.05),smaller hip flexion angle (P<0.01),and smaller hip external rotation angle (P<0.05). Group B had a smaller knee flexion angle,hip flexion angle,hip external rotation angle,and greater knee external rotation angle (all P<0.01) compared to group C. Additionally,group A exhibited a greater hip internal rotation moment (P<0.05) and plantarflexion moment (P<0.01) compared to group C. (3) At normal speed during the staircase buffering phase,group C showed higher activation levels than group A in the vastus lateralis (P<0.05),vastus medialis (P<0.01),gluteus medius (P<0.01),and biceps femoris (P<0.05). Group C also had higher activation levels than group B in the vastus medialis (P<0.01),gluteus medius (P<0.01),and biceps femoris (P<0.05). Additionally,group A showed higher activation in the semitendinosus and semimembranosus muscles compared to group B (P<0.05). (4) These findings indicate that young female patients with patellofemoral pain syndrome have stiffer hip and knee joint buffering while descending stairs,potentially compensated by the ankle joint. Low muscle activation levels contribute to patellofemoral pain,with those having normal subtalar joints but experiencing pain showing the lowest and most abnormal activation. ③ Abnormal biomechanics in the normal subtalar joint group are mainly due to insufficient hip and knee flexion. Abnormal biomechanics in the abnormal subtalar joint group are mainly due to excessive subtalar joint pronation.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

BACKGROUND:Currently,research both domestically and internationally on patellofemoral pain syndrome has explored the kinematics and dynamics during daily activities such as stair ascent and descent,and walking. However,there is a lack of studies examining the lower limb biomechanical characteristics of young female patients with patellofemoral pain syndrome in different squatting conditions.OBJECTIVE:To investigate the lower limb biomechanical characteristics among young female patients with patellofemoral pain syndrome in different functional states of the subtalar joint,providing theoretical support for the clinical treatment of various types of patellofemoral pain syndrome.METHODS:A total of 33 participants were included in this study. There were 10 subjects in the healthy control group (group C). The other 27 subjects with patellofemoral pain syndrome were divided into two groups according to the foot posture index:14 subjects in the normal subtalar joint group (group A,foot posture index 0-6 points) and 13 subjects in the abnormal subtalar joint group (group B,foot posture index 7-12 points). The biomechanical indices of thesubjects in each group were collected and compared when they walked on stairs at normal speed. The kinematic indices included the three-dimensional joint angles of the hip and knee and the sagittal plane joint angles of the ankle at the initial contact moment and the moment of maximum knee flexion angle during the stance period. The dynamic indices included the three-dimensional joint torques of the hip and knee and the sagittal plane joint torques of the ankle at the moment of maximum knee flexion angle during the stance period. The surface electromyography indices included the root mean square amplitudes of the vastus medialis,vastus lateralis,rectus femoris,semitendinosus and semimembranosus,biceps femoris,and gluteus medius in the pre-activation stage and the buffering stage.RESULTS AND CONCLUSION:(1) At the initial ground contact moment,group A exhibited a greater knee flexion angle (P<0.05),greater hip external rotation angle (P<0.01),and smaller knee external rotation angle (P<0.01) compared to group B. Compared to group C,group A showed a greater knee flexion angle and smaller hip flexion angle (both P<0.01). Group B demonstrated a greater knee external rotation angle and smaller hip external rotation angle and hip flexion angle (all P<0.01) compared to group C. (2) At the moment of maximum knee flexion,group A had a smaller knee valgus angle (P<0.05),smaller knee external rotation angle (P<0.05),and greater knee flexion angle (P<0.01) compared to group B. Compared to group C,group A showed a smaller knee valgus angle (P<0.05),smaller hip flexion angle (P<0.01),and smaller hip external rotation angle (P<0.05). Group B had a smaller knee flexion angle,hip flexion angle,hip external rotation angle,and greater knee external rotation angle (all P<0.01) compared to group C. Additionally,group A exhibited a greater hip internal rotation moment (P<0.05) and plantarflexion moment (P<0.01) compared to group C. (3) At normal speed during the staircase buffering phase,group C showed higher activation levels than group A in the vastus lateralis (P<0.05),vastus medialis (P<0.01),gluteus medius (P<0.01),and biceps femoris (P<0.05). Group C also had higher activation levels than group B in the vastus medialis (P<0.01),gluteus medius (P<0.01),and biceps femoris (P<0.05). Additionally,group A showed higher activation in the semitendinosus and semimembranosus muscles compared to group B (P<0.05). (4) These findings indicate that young female patients with patellofemoral pain syndrome have stiffer hip and knee joint buffering while descending stairs,potentially compensated by the ankle joint. Low muscle activation levels contribute to patellofemoral pain,with those having normal subtalar joints but experiencing pain showing the lowest and most abnormal activation. ③ Abnormal biomechanics in the normal subtalar joint group are mainly due to insufficient hip and knee flexion. Abnormal biomechanics in the abnormal subtalar joint group are mainly due to excessive subtalar joint pronation.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective:To analyze the genetic characteristics of the VWF gene c.7332G＞A nonsense mutation and explore its molecular pathogenesis.Methods:Phenotypic diagnosis of the proband was performed using VWF:Ag,VWF:RCo,FⅧ:C and multimeric analysis.The probands were genotyped by NGS whole-exome sequencing,and the sequencing results were validated by sanger sequencing.The family members were genotyped by Sanger sequencing.The VWF gene c.7332G＞A nonsense mutant plasmid was constructed.After transfection,the function of VWF gene c.7332G＞A mutant plasmid was verified at cell level in vitro.The mRNA level was detected by qRT-PCR,and the expression level of protein was detected by Western blot,the function of multimerization was verified by the multimeric analysis.Results:VWF:Ag and VWF:RCo were all less than 3％in the proband,and the multimeric analysis showed multimer deficiency.The proband was diagnosed as type 3 VWD.The homozygous nonsense mutation of VWF gene c.7332G＞A was detected by gene sequencing.The VWF mRNA level of the mutant plasmid was decreased,and the VWF protein expression in the cell supernatant was decreased,the mutant protein was truncated and the function of VWF multimerization was impaired.Conclusion:A homozygous mutation in exon 43 of VWF gene,c.7332G＞A,was responsible for the probands type 3 VWD in the proband.The mutation caused a decrease in the relative level of VWF mRNA and protein,and impaired the function of VWF multimerization.

This study investigated the full-genome molecular characteristics of a rotavirus vaccine-derived strain,G1P[8]geno-type A group rotavirus RVA/Human-wt/CHN/HN1140/2021/G1P[8](referred to as HN1140).The gene fragments of the HN1140 strain were amplified with reverse transcription-polymerase chain reaction(RT-PCR)combined with whole-genome primers to obtain the full genome sequence.Genotyping was performed with the online genotyping tool RotaC 2.0,and similarity and genetic evolution analyses for each gene segment were conducted in DNAstar5.1 and MEGA11.0 software.The genotype of the HN1140 strain was deter-mined to be G1-P[8]-I2-R2-C2-M2-A3-N2-T6-E2-H3.Phylogenetic analysis demonstrated that all 11 genomic segments clus-tered closely with the RotaTeq vaccine strains,sharing 99.7%-100%nucleotide sequence similarity.Notably,VP1,VP2,VP6,and NSP2-NSP5 segments showed 100%nucleotide identity with RotaTeq strains.Comparative genomic analysis identified 13 nucleotide and 8 amino acid substitutions between HN1140 and RotaTeq strains,localized within the VP7,VP4,VP1,VP2,VP3,and NSP1 segments.The HN1140 strain exhibited the genotype G1-P[8]-A3-T6-H3,which was consistent with the typical profile of a vaccine-derived reassortant.This strain demonstrated high genetic similarity to RotaTeq vaccine strains,with nucleotide sequence identity ranging from 99.7%to 100%.These findings suggested that HN1140 evolved from RotaTeq vaccine strains through genetic reassortment.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.