A derivatizaton method combined with gas chromatography-mass spectrometry(GC-MS)was established for detection of isobutyl chloroformate(IBCF)residue in active pharmaceutical ingredient of agatroban.The extraction and derivatization reagents,derivatization time,qualitative and quantitative ions were selected and optimized,respectively.The possible mechanism of derivatization and characteristic fragment ions fragmentation were speculated.The agatroban samples were dissolved and extracted by methanol,and the residual IBCF was derived with methanol to generate methyl isobutyl carbonate(MIBCB).After 24 h static derivatization at room temperature,IBCF was completely transformed into MIBCB,which could be used to indirectly detect IBCF accurately.The results showed that the linearity of this method was good in the range of 25-500 ng/mL(R2=0.9999).The limit of detection(LOD,S/N=3)was 0.75 μg/g,and the limit of quantification(LOQ,S/N=10)was 2.50 μg/g.Good recoveries(95.2%-97.8%)and relative standard deviations(RSDs)less than 3.1%(n=6)were obtained from agatroban samples at three spiked levels of IBCF(2.50,25.00,50.00 μg/g),which showed good accuracy of this method.Good precision of detection results was obtained by different laboratory technicians at different times,the mean value of spiked sample solution(25.00 μg/g)was 24.28 μg/g,and the RSD was 2.1%(n=12).The durability was good,minor changes of detection conditions had little effect on the results.Under the original condition and conditions with initial column temperature±5℃,heating rate±2℃/min,column flow rate±0.1 mL/min,the IBCF content of spiked sample solution(25.00 μg/g)was detected,the mean value of detection results was 24.16 μg/g,and the RSD was 2.2%(n=7).Eight batches of agatroban samples from two manufacturers were detected using the established method,and the results showed that no IBCF residue was detected in any of these samples.The agatroban samples could be dissolved by methanol,and then the IBCF residue could be simultaneously extracted and derived with methanol as well.This detection method had the advantages of simple operation,high sensitivity,low matrix effect and accurate quantification,which provided a new effective method for detection of IBCF residue in agatroban.

Objective A simple,sensitive and rapid ultra high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)method was developed and validated for the determination of ertapenem in human plasma.Methods Using ertapenem-D4 as internal standard,the protein in plasma was precipitated with acetonitrile;chromatographic column:ACQUITY HSS T3(2.1 mm × 50.0 mm,1.8 μm);the mobile phase was 0.1％formic acid aqueous solution(containing 2 mmol·L-1 ammonium formate)-acetonitrile(0.1％formic acid),using a gradient elution;flow rate:0.4 mL·min-1,injection volume:1 μL,column temperature:45 ℃,the analysis time was 4.5 min,the scanning mode is positive ion selective reaction monitoring mode(SRM)with an electric spray ion source(ESI).The specificity,standard curve and lower limit of quantification,precision and recovery,matrix effect,dilution effect and stability were investigated.Results Ertapenem had a good linearity within 0.5-80.0μg·mL-1,and the standard curve was y=4.25 × 10-1x-2.64× 10-2(r2=0.999 0),the lower limit of quantification was 0.5 μg·mL-1,the relative standard deviation within and between batches is 1.39％-4.15％.The extraction recovery rate was 58.36％-64.57％,and the relative standard deviation of dilution effect was 3.30％,and the matrix effect was 99.71％-103.23％.The relative standard deviation of room temperature,repeated freeze-thaw,4 ℃,and long-term stability are all less than 10％.Conclusion The method is sensitive,rapid and specific,which is suitable for clinical monitoring of Ertapenem.

AIM To evaluate the quality of Beidougen Formula Granules.METHODS Fifteen batches of standard decoctions and three batches of formula granules were prepared,after which paste rate and contents,transfer rates of magnoflorine,daurisoline,dauricine were determined.HPLC specific chromatograms were established,and cluster analysis was adopted in chemical pattern recognition.RESULTS For three batches of formula granules,the paste rates were 15.1%-16.6%,the contents of magnoflorine,daurisoline,dauricine were 18.93-19.39,9.42-9.60,6.79-6.85 mg/g with the transfer rates of 34.42%-35.25%,43.81%-44.65%,27.27%-27.51%from decoction pieces to formula granules,respectively,and there were seven characteristic peaks in the specific chromatograms with the similarities of more than 0.95,which demonstrated good consistence with those of standard decoctions and accorded with related limit requirements.Fifteen batches of standard decoctions were clustered into two types,and the medicinal materials produced from Jilin,Hebei,Shangdong could be used for the preparation of formula granules.CONCLUSION This reasonable and reliable method can provide references for the quality control and clinical application of Beidougen Formula Granules.

In recent years, studies have shown that exosomes can replace mesenchymal stem cell for chronic wound repair. However, exosomes have some problems such as poor targeting, low availability and low yield, so it has limited effect in the treatment of chronic wound. Maximizing the therapeutic benefits of exosomes is the primary challenge that needs to be overcome when used for chronic wound repair. Studies have shown that the treatment potential of exosomes can be further developed by pretreatment and engineering modification of exosomes. This article reviewed the research progress of exosome pretreatment and engineering modification in chronic wound repair, and provided reference for subsequent research and clinical application.

Following the principles of evidence-based medicine,in accordance with the structure and drafting rules of standardized documents,based on literature research,according to the characteristics of chronic cough in children and issues that need to form a consensus,the TCM Guidelines for Diagnosis and Treatment of Chronic Cough in Children was formulated based on the Delphi method,expert discussion meetings,and public solicitation of opinions.The guideline includes scope of application,terms and definitions,eti-ology and diagnosis,auxiliary examination,treatment,prevention and care.The aim is to clarify the optimal treatment plan of Chinese medicine in the diagnosis and treatment of this disease,and to provide guidance for improving the clinical diagnosis and treatment of chronic cough in children with Chinese medicine.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

In recent years, studies have shown that exosomes can replace mesenchymal stem cell for chronic wound repair. However, exosomes have some problems such as poor targeting, low availability and low yield, so it has limited effect in the treatment of chronic wound. Maximizing the therapeutic benefits of exosomes is the primary challenge that needs to be overcome when used for chronic wound repair. Studies have shown that the treatment potential of exosomes can be further developed by pretreatment and engineering modification of exosomes. This article reviewed the research progress of exosome pretreatment and engineering modification in chronic wound repair, and provided reference for subsequent research and clinical application.

This study was aimed at studying the phenotypic and molecular characteristics of a Salmonella Grumpensis isolate from a patient with diarrhea in Shanghai,to provide evi-dence for the prevention of salmonellosis.Biochemical identifi-cation,serum agglutination testing,antimicrobial susceptibility testing,and whole genome sequencing(WGS)were performed on isolate 2023JD76.Global Salmonella Grumpensis genome sequences were searched and downloaded for serotyping predic-tion,multilocus sequence typing(MLST),prediction of anti-microbia resistance genes and virulence genes,and phylogenetic analysis of 2023JD76.The 2023JD76 strain was identified as Salmonella Grumpensis(13,23:d:1,7)with ST2060,and was susceptible to 20 antimicrobial agents.Strain 2023JD76 carried the aminoglycoside resistance gene aac(6')-Iaa and five types of virulence genes:the adhesion genes csg and rat;the secretion and transport genes sip and inv;the typhoid toxin genes cdt and plt;the invasive gene nutrient metabolism factor mgt;and the antimicrobial peptide resistance factor mig.Global S.Grumpensis strains harbored ten types of antimicrobial resistance genes whose prevalence ranged from 58.33％to 100％.The global genome sequences of S.Grumpensis were divided into two lineages.Lineage I was dominated by ST751(88.89％,16/18),and lineage Ⅱ was dominated by ST2060(89.47％,17/19).The genome sequence of strain 2023JD76 belonged to lineage Ⅱ,and was closely related to the genome sequences from human fecal and human cerebrospinal fluid.This study provides the first report of a S.Grumpensis isolate from the stool of a patient with diarrhea in China.Considerable variability in antimicrobial resistance genes was observed among genome sequences from different sources,and the strains harbored a substantial number of virulence genes.Enhanced surveillance should be emphasized to prevent a potential risk of global dissemination.

Objective:We aimed to develop a novel visualized model based on nomogram to predict postoperative overall survival.Methods:This was a multicenter, retrospective, observational cohort study, including participants with histologically confirmed gastric and colorectal cancer who underwent radical surgery from 11 medical centers in China from August 1, 2015 to June 30, 2018. Baseline characteristics, histopathological data and nutritional status, as assessed using Nutrition Risk Screening 2002 (NRS 2002) score and the scored Patient-Generated Subjective Global Assessment, were collected. The least absolute shrinkage and selection operator regression and Cox regression were used to identify variables to be included in the predictive model. Internal and external validations were performed.Results:There were 681 and 127 patients in the training and validation cohorts, respectively. A total of 188 deaths were observed over a median follow-up period of 59 (range: 58 to 60) months. Two independent predictors of NRS 2002 and Tumor-Node-Metastasis (TNM) stage were identified and incorporated into the prediction nomogram model together with the factor of age. The model's concordance index for 1-, 3- and 5-year overall survival was 0.696, 0.724, and 0.738 in the training cohort and 0.801, 0.812, and 0.793 in the validation cohort, respectively.Conclusions:In this study, a new nomogram prediction model based on NRS 2002 score was developed and validated for predicting the overall postoperative survival of patients with gastric colorectal cancer. This model has good differentiation, calibration and clinical practicability in predicting the long-term survival rate of patients with gastrointestinal cancer after radical surgery.

Objective:To determine the differential expressions of long non-coding RNA(lncRNA)and messenger RNA(mRNA)in normal and asthenospermia(AS)men and analyze their biological significance in AS.Methods:We isolated and ex-tracted total RNAs from 9 normal and 9 AS sperm samples,determined the expressions of RNAs in the sperm using the DNBSEQ se-quencing platform,and analyzed their relevant functions by gene ontology enrichment(GO)and Kyoto encyclopedia of genes and ge-nomes pathway(KEGG)analyses.Results:An average of 10.64G data was generated per group,with 282 185 RNAs detected,in-cluding 107 009 lncRNAs.Among the total number of lncRNAs,15 157 were differentially expressed,2 190 upregulated and 12 967 downregulated;and among the 19 514 mRNAs,13 736 were differentially expressed,4 995 upregulated and 8 741 downregulated.Differentially expressed genes were enriched mainly in the sperm cell membrane and the pathways related to the ion channel functions,sperm development and fertilization.Conclusion:Differentially expressed lncRNAs and mRNAs can be identified by sequencing a-nalysis of AS and normal sperm.Regulation of sperm function through membrane ion channels may contribute to the development of AS,which provides a molecular basis for further research on AS.