Objective To understand the pathogenic molecular characteristics of the latest prevalent Group A Streptococcus(GAS)in a suburban area of Beijing.Methods Throat swab specimens from children suspected of GAS infection in the outpatient setting of a sentinel surveillance hospital in a suburban area of Beijing from January 2023 to June 2025 were collected.GAS strains were detected and cultured.Antimicrobial susceptibility testing on 12 antimicrobial agents were performed,and molecular epidemiological characteristics of GAS strains was further ana-lyzed by whole genome sequencing technique.Results Data of 326 children suspected of GAS infection in outpatient setting were collected.A total of 41 GAS strains were detected and cultured,with a detection rate of 12.58％.The proportions of children with anterior cervical lymph node enlargement,tonsil congestion,and jaw congestion in the GAS positive group were all higher than those in the GAS negative group,and differences were all statistically sig-nificant(all P＜0.05).All 41 GAS strains carried both erm(B)and tet(M)resistance genes and exhibited a struc-tural type(cMLS)resistance phenotype.All of the emm12 strains were ST36,and emm1 strains were ST28.A to-tal of 6 emm12 subtypes and 1 emm1 subtype were detected,namely emm12.2,emm12.95,emm12.69,emm12.17,emm12.19,emm12.149,and emm1.12.Among them,emm12.149 was a newly discovered subtype.Nucleobase at the 175 100 locus in gene sequence had undergone an A→ T mutation.A total of 5 bacteriophages and 6 superanti-gens were detected.There were statistically significant differences in multi-nucleotide polymorphisms(MNPs)and insertion numbers in the genomes of emm12.0 and emm12 subtypes(both P＜0.05).The phylogenetic tree presen-ted a highly clonal group of 23 GAS strains in this area,accounting for 57.50％.Conclusion The prevalent GAS strain in this area is emm12.emm12.149 is a new subtype.The resistance genes and phenotypes are erm(B),tet(M),and structural type(cMLS).The genome has plenty genetic polymorphism,and the genome sequences of multiple GAS strains are highly cloned,indicating the possibility of clone transmission.This suggests that the sur-veillance of GAS in sentinel hospitals should continue to be strengthened,so as to provide theoretical basis for the prevention and control of GAS epidemics.

Objective To understand the pathogenic molecular characteristics of the latest prevalent Group A Streptococcus(GAS)in a suburban area of Beijing.Methods Throat swab specimens from children suspected of GAS infection in the outpatient setting of a sentinel surveillance hospital in a suburban area of Beijing from January 2023 to June 2025 were collected.GAS strains were detected and cultured.Antimicrobial susceptibility testing on 12 antimicrobial agents were performed,and molecular epidemiological characteristics of GAS strains was further ana-lyzed by whole genome sequencing technique.Results Data of 326 children suspected of GAS infection in outpatient setting were collected.A total of 41 GAS strains were detected and cultured,with a detection rate of 12.58％.The proportions of children with anterior cervical lymph node enlargement,tonsil congestion,and jaw congestion in the GAS positive group were all higher than those in the GAS negative group,and differences were all statistically sig-nificant(all P＜0.05).All 41 GAS strains carried both erm(B)and tet(M)resistance genes and exhibited a struc-tural type(cMLS)resistance phenotype.All of the emm12 strains were ST36,and emm1 strains were ST28.A to-tal of 6 emm12 subtypes and 1 emm1 subtype were detected,namely emm12.2,emm12.95,emm12.69,emm12.17,emm12.19,emm12.149,and emm1.12.Among them,emm12.149 was a newly discovered subtype.Nucleobase at the 175 100 locus in gene sequence had undergone an A→ T mutation.A total of 5 bacteriophages and 6 superanti-gens were detected.There were statistically significant differences in multi-nucleotide polymorphisms(MNPs)and insertion numbers in the genomes of emm12.0 and emm12 subtypes(both P＜0.05).The phylogenetic tree presen-ted a highly clonal group of 23 GAS strains in this area,accounting for 57.50％.Conclusion The prevalent GAS strain in this area is emm12.emm12.149 is a new subtype.The resistance genes and phenotypes are erm(B),tet(M),and structural type(cMLS).The genome has plenty genetic polymorphism,and the genome sequences of multiple GAS strains are highly cloned,indicating the possibility of clone transmission.This suggests that the sur-veillance of GAS in sentinel hospitals should continue to be strengthened,so as to provide theoretical basis for the prevention and control of GAS epidemics.

Objective To explore the expression of miR-548j-5p in pancreatic cancer and its effect on the invasion of pancreatic cancer. Methods Tissue samples of 16 patients with pancreatic cancer who received treatment in Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science &Technology between January 2016 and January 2017 were collected. There were 8 males and 8 females, aged from 41 to 62, including 7 cases with an age of ≤50 and 9 cases with an age of >50. The informed consents of all patients were obtained and the local ethical committee approval was received. The expression of miR-548j-5p in pancreatic cancer and adjacent tissues was detected by RT-PCR. PANC-1 cells were transfected by mimic and inhibitor of miR-548j-5p to construct PANC-1 cells with over-expression and low-expression of miR-548j-5p. And in control group, PANC-1 cells were transfected with empty plasmid Ctrl. The effect of miR-548j-5p on PANC-1 invasion was detected by Transwell assay, and its effect on PANC-1 metastasis was evaluated by wound scratch assay. Comparison of three groups was conducted by one-way analysis of variance and LSD-t test. Results The median relative expression of miR-548j-5p in pancreatic cancer was 0.35(0.03-4.47), significantly lower than 4.30 (0.04-65.55) in adjacent tissues (Z=-2.689, P<0.05).Transwell assay results showed that the average number of cells penetrating membrane was(58±34) in miR-548j-5p over-expression group, significantly lower than (231±61) in control group (LSD-t=-2.852, P<0.05);and it was(491±149)in miR-548j-5p low-expression group,significantly higher than that in control group (LSD-t=4.313, P<0.05). The wound scratch assay results showed that the wound scratch healing rate was (20±8)% in miR-548j-5p over-expression group, significantly lower than (38±6)% in control group (LSD-t=-3.759, P<0.05); and it was (53±6)% in miR-548j-5p low-expression group, significantly higher than that in control group (LSD-t=2.946, P<0.05). Conclusions Low expression of miR-548j-5p is observed in pancreatic cancer. Over expression of miR-548j-5p can decrease the invasive and metastatic ability of pancreatic cancer.

Objective To observe the influence of direct peritoneal resuscitation on liver function in hemorrhagic shock rabbits with pyruvate peritoneal dialysis solution instead of lactate peritoneal dialysis solution. Methods 48 hemorrhagic shock rabbits were randomly divided into conventional intravenous resuscitation group (group A),intravenous resuscitation plus intraperitoneal injection of lactate peritoneal dialysis solution group (group B),intravenous resuscitation plus intraperitoneal injection of pyruvate peritoneal dialysis group(group C), intravenous pyruvate peritoneal dialysis resuscitation plus intraperitoneal injection of pyruvate peritoneal dialysis group(group D). The hemodynamic changes were observed and the AST and ALT were measured respectively before and 60 min after shock ,60 min and 180 min after resuscitation. The dry/wet weight ratio ,MDA and SOD of liver tissue were measured,and the liver morphological changes were observed. Results After the completion of shock resuscitation,MAP of all groups were almost restored to the basal level. 180 min after resuscitation,the MAP of animals in group A was lowered than that in group B,C and D(P<0.05). After shock,ALT and AST were signifi-cantly higher than those before shock ,but no significant difference was found between groups (P > 0.05). After resuscitation,ALT and AST continued to decline in all groups,but the decline range increased with the order of A, B,C,D group(P < 0.05). The water content and MDA in liver tissue decreased with the order of A,B,C,D group,while the SOD increased and the differences between groups were significant(P<0.05). And the degree of liver tissue morphological injury also relieved correspondingly. Conclusion Pyruvate substituting lactate peritoneal dialysis solution peritoneal resuscitation can be more effective in reducing liver damage of hemorrhagic shock rabbits.

Objective To observe the effects of peritoneal resuscitation by pyruvate replacing lactate peritoneal dialysis solution on the intestinal mucosal barrier in rabbits with hemorrhagic shock.Methods The hemorrhagic shock model was prepared in 48 healthy male rabbits by adopting the improved Wiggers method.Then the rabbits were randomly divided into the conventional intravenous resuscitation group (group A),conventional intravenous resuscitation plus intraperitoneal injection of lactate peritoneal dialysis solution group (group B),conventional intravenous resuscitation plus intraperitoneal injection of pyruvate peritoneal dialysis solution group (group C) and intravenous pyruvate peritoneal dialysis solution resuscitation plus intraperitoneal injection of pyruvate peritoneal dialysis solution group (group D).The levels of diamine oxidase (DAO) and lipopolysaccharide (LPS) were measured before shock,at 60 min after shock,at 60,180 min after resuscitation.At the end of observation,the ileum tissues were taken from the 5 cm away from the ileocecal region for measuring the dry/wet ratio,malondialdehyde (MDA) level and superoxide dismutase (SOD) activity and their morphological changes was observed.Results There was no statistical difference in the plasma levels of DAO and LPS before shock among the four groups (P＞0.05);which at 50 min after shock were increased,but the comparison among the groups had no statistical difference (P＞0.05);the plasmas levels of DAO and LPS at 60,180 min after resuscitation in the group A,B,C and D were decreased in turn (P＜0.05).The MDA levels of ileum tissues after 180 min of resuscitation in the group A,B,C and D were decreased in turn (P＜0.05),but the SOD activties and tissue dry/wet mass ratios were increased in turn (P＜005),moreover the tissue injury degrees were also relieved in turn.Conclusion The peritoneal resuscitation by pyruvate replacing lactate peritoneal dialysis solution can more effectively protect the intestinal tissue cells and reduce intestinal mucosal damage in hemorrhagic shock rabbits.

Purpose　Both the working standard and corresponding sample(GRAN75)were first calibrated by WHO international standard for G-CSF.Methods　MTT method by NFS-60 cells was used. The results were calculated by (4,4)method.Results　Three batchs working standards were prepared,two batchs were freeze-dry and the prescription was same as WHO international standard for G-CSF,one batch was injection and the prescription was same as corresponding sample(GRAN75).The biological potency and the FL% of average potency were 3.062×106 、4.276×106IU/ampoule、1.635×107IU/ml and 5.529%、4.291%、4.244% for working standard, and 1.880×107IU/ml and 5.175% for corresponding sample,respectively.Conclusion　The working standard which calibrated could be used as working standard in the measurement of rhG-CSF biological activity.

Purpose　The determination method of rhG-CSF bio logical activity by NFS-60 cells was studied in accordance with WHO internation al standard for G-CSF.Methods　MTT method was adopted.R esults　The chomosone number of NFS-60 cell was 39, about 1×105 cells/ml to 1×107 cells/ml,the dying color showed gradient when the NFS-60 c ells was dyed by MTT,the method(4,4) was adopted in the determination of rhG-CS F biological activity,the average FL% of potency was 13.560% for single exprimen t,and the CV of inter-assay and intra-assay was lower than 10% and 10.109%,respectively.Conclusion　method(4,4) can be us ed in the determination of rhG-CSF biological activity,and the results can guid e the study and the manufacture of rhG-CSF effectively.

Objective To investigate the changes of Toll-like receptor 2 and 4 gene expression in lungs with acute injury induced by acute hemorrhagic necrotizing pancreatitis(AHNP) in rats.Methods Forty SD male rats were randomly divided into sham-operated group(n=10),and AHNP group(n=30).Of all the rats,the lungs were dissected for lung histological scores and bronchoalveolar lavages were harvested for lung injury index.TLR2,4mRNA expression in the lungs was measured by RT-PCR at different time points.(Results) TLR2,4mRNA could be detected in lungs with low values in sham-operated group;but they were markedly increased at 3 hours in AHNP group,peaking at 6~12 hours(P