This paper discussed how to set the limit of impurities in the quality standard when the impurities in small-molecular innovative drugs were metabolites.Firstly,through the analysis and interpretation of each relevant guideline,in combination with the review cases of FDA and EMA,found out the conditions for qualification of im-purity,and then establ ish the acceptable limit of impurities based on the test results of multiple batches,the incre-ments of production process and storage process.

Objective:To investigate the positive rate and isolate Bordetella pertussis in children with suspected whooping cough and their close family members in Zhejiang Province, and further explore the susceptibility and resistant mechanism of Bordetella pertussis to antibiotics. Methods:A total of 273 nasopharynx swabs specimens from children with suspected whooping cough in Hangzhou Children′s Hospital from May 2022 to October 2022 were collected. The strains were isolated and cultured using charcoal select agar plate. Pertussis target genes were detected by RT-PCR. E-test method was used to detect the sensitivity of Bordetella pertussis strains to different antibiotics. The mechanism of resistance of Bordetella pertussis to macrolides was analyzed by whole genome sequencing. The phylogenetic analysis of isolated strains was based on core genome multilocus sequence typing(cgMLST). Results:Among 273 clinical samples of children with suspected pertussis and their close family members, 168 samples were positive by fluorescence quantitative PCR, accounting for 61.54%, and 30 pertussis strains were successfully isolated with a positive rate of 10.98%. In addition, among the 143 samples of close family members, 54.55% (78/143) samples were positive by RT-PCR and 9.79% (14/143) samples were positive by culture, suggesting that the close family member are important in family transmission of pertussis. Besides, most of the positive samples were from mothers. The results of E-test showed that 96.67%(29/30) strains showed high resistance to azithromycin with MIC value>256 mg/L, and the resistant mechanism of azithromycin was A2047G mutation in 23S rRNA. The phylogenetic analysis based on the cgMSLT showed that the isolated strains were clustered into two new different clades.Conclusions:The positive rate of Bordetella pertussis in close family members is at a high level and the mother may be the main source of infection, which is of great significance for monitoring and laboratory detection of suspected children′s family members. Bordetella pertussis shows high resistance to macrolides in Zhejiang Province, so monitoring of the antimicrobial resistance should be further strengthened to provide theoretical basis for clinical treatment and drug guidance.

Objective:To identify the phosphodiesterase (PDE) activity of the gene product encoded by LA_RS06960 of Leptospira interrogans ( L. interrogans), and analyze whether dinucleotides that can be degraded by PDE can activate macrophages to express innate immune factors. Methods:The LA_RS06960 gene in L. interrogans strain 56601 was amplified by PCR, and the prokaryotic expression system was constructed for the protein expression. The expressed rPDE was purified by Ni-NTA affinity chromatography. High performance liquid chromatography (HPLC) was used to measure the degration of c-di-AMP or 5′-pApA to AMP by rPDE. Real-time fluorescent quantitative RT-PCR (qRT-PCR) was used to detect the changes in the expression of target genes in Leptospira or THP-1 cells associated with innate immune factors during infection. qRT-PCR and ELISA were used to detect the changes in the expression and secretion level of the innate immune factors in macrophages treated with bacterial dinucleotide. Results:The prokaryotic expression system for LA_RS06960 gene of L. interrogans was constracted successfully, and the purified rPDE could degrate 5′-pApA and c-di-AMP into AMP in vitro. The mRNA level of leptospiral LA_RS06960 gene was significantly down-regulated, while IFN-β, TNF-α, IL-6 and IL-1β encoding genes of macrophages were significantly up-regulated during infection. The mRNA level or the secretion level of IFN-β and IL-6 of macrophages were increased after treated with the bacterial dinucleotide substrate of PDE. Conclusions:PDE encoded by LA_RS06960 gene has phosphodiesterase activity, and the bacterial dinucleotide substrate of the PDE could activate the innate immune response of macrophages.

Objective To screen items of the Clinical Aided Decision Scheme for Stroke Simultaneous Treatment of Disease,Pulse and Syndrome;To provide reference for the formulation and improvement of the scheme.Methods The Delphi method was used to distribute two rounds of questionnaires to 60 experts in cerebropathy or neurology across the country.Statistical analysis was performed on the questionnaire results of the scheme's items,including the disease names,etiology and pathogenesis,syndrome characteristics,rules and regulations,representative prescriptions,acupuncture and other therapies,and preventive care.Results Totally 42 and 50 valid questionnaires were collected.The experts reached the consensus for the importance of etiology and pathogenesis,rules and regulations,acupuncture and other therapies,and preventive care.In the section on syndrome characteristics,items with low relevance or causing ambiguity were removed.Items that were no longer used in modern times and different prescriptions with the same name were removed from the representative prescriptions.The names of syndromes,rules and regulations were unified.Conclusion The experts generally reached the consensus for the importance of the Clinical Aided Decision Scheme for Stroke Simultaneous Treatment of Disease,Pulse and Syndrome.However,there are still some limitations that require further study and discussion.

OBJECTIVE To study the effects of transferrin-targeting peptide T7 （7pep） on intracellular transportation of polyethylene glycol-polycaprolactone （PEG-PCL） micelles in human cervical cancer HeLa cells. METHODS Using coumarin-6 （C6） as fluorescent indicator probe， both coumarin-6 （C6）-loaded PEG-PCL （PEG-PCL-C6） micelles and 7pep-modified PEG- PCL （7pep-PEG-PCL-C6） micelles were prepared by film-dispersion method. The particle size， polydispersity index and appearance morphology were compared between two types of micelles； the real-time uptake of two types of micelles by HeLa cells was compared， and the colocalization of two types of micelles with early endosomes （EE）， endocytic recycling compartments （ERC） and late endosomes （LE） after entry into the cells was observed. RESULTS The particle sizes of PEG-PCL-C6 and 7pep-PEG-PCL- C6 micelles were（75.0±2.3）and（82.0±1.5）nm； the polymer dispersity indexes were 0.17±0.20 and 0.17±0.32， respectively， with a regular spherical appearance. The colocalization results showed that entry speed and amount of 7pep-PEG-PCL-C6 micelles were significantly faster/more than those of PEG-PCL-C6 micelles. 7pep-PEG-PCL-C6 micelles entered EE faster than PEG-PCL-C6 micelles， while PEG-PCL-C6 micelles entered ERC at a faster rate than 7pep-PEG-PCL-C6 micelles， and both PEG-PCL-C6 micelles and 7pep-PEG-PCL-C6 micelles tended to accumulate gradually in LE； Pearson coefficient， signal overlap ratio， and colocalization ratio of 7pep-PEG-PCL-C6 micelles with LE were significantly lower 60 minutes after entering the cell than those 30 minutes after entering the cell （P＜0.05 or P＜0.01）. CONCLUSIONS Targeting 7pep modification can increase the entry speed and amount of PEG-PCL-C6 micelles， and also alter their intracellular transportation behavior.

Primary central nervous system lymphoma (PCNSL) is a highly aggressive malignant lymphoma. As most chemotherapy drugs have difficulty in crossing the blood-brain barrier, PCNSL shows a difficulty in clinical treatment, a high recurrence rate and a poor prognosis. Early identification of relapsed patients and prompt initiation of salvage therapy play a critical role in the improvement of patients' prognosis. Brain biopsy is the gold standard to identify recurrence, while the risk of operation failure and complications is still high. Non-invasive imaging techniques are beneficial for early identification of recurrence in PCNSL and can provide an important basis for guiding relapsed patients to adjust treatment plans in time. However, there is no unified evaluation standard for imaging methods of monitoring the relapsed lesions of PCNSL. With the further research of the pathophysiological mechanism of PCNSL, biomarker detection has become a new method to identify recurrence and more clinical evidence is still needed in the future.

Objective To investigate the regulatory mechanism of apurnic/apyrimidinic endonuclease 1(APE1)in the transformation of chronic intestinal inflammation to colitis-associated colorectal cancer(CAC).Methods C64S mutant(APE1C64S)mice and APE1 wild type(APE1WT)mice were randomly divided into experimental group and control group.In vivo CAC model was established by azoxymethane(AOM)and dextran sulfate sodium salt(DSS)solution.Immunohistochemistry(IHC)and multiple IHC(mIHC)assays were used to observe the expression of APE1 and immune cell infiltration in colon tissues of each group.A mouse colon cancer cell line MC38 with stable knockdown of APE1 was constructed by lentivirus transfection,and subcutaneous tumor bearing experiments were performed in APE1WT and APE1C64S mice to confirm that tumor cell-derived APE1 caused immunosuppressive tumor microenvironment.The expression of APE1 and CXCL1[chemokine(C-X-C motif)ligand 1]and the infiltration of immune cells in tumor-bearing specimens were analyzed by IHC and mIHC assays.The tumor specimens of a 28-year-old female patient with CAC from Army Medical Center of PLA were analyzed for the expression of APE1 and CXCL1 and the infiltration of immune cells in the tumor and adjacent inflammatory tissues by IHC and mIHC assays.Results Compared with the control group and APE1WT erperimental group,APE1C64S erperimental group had significantly reduced disease activity index and tumor formation,polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs)infiltration,and CD4+and CD8+T cells(P＜0.05).No significant differences were observed in tumor growth and immune cells between APE1WT and APE 1C64S mice bearing subcutaneous tumors.However,in the tumor-bearing experiment using tumor cells with knockdown of APE1,the tumor growth was significantly lower and the number of infiltrated PMN-MDSCs was reduced,while those of CD4+and CD8+T cells were significantly increased(P＜0.05).Furthermore,high expression of APE1 and increased infiltration of PMN-MDSCs were found in the tumor tissues of the young CAC patient,and CD8+T cells were significantly reduced in the tumor tissues compared with the inflammatory tissues(P＜0.05).Conclusion APE1-redox in tumor cells can promote the infiltration of PMN-MDSCs and reduce the number of T cells,thereby forming an immunosuppressive tumor microenvironment and mediating the occurrence and development of CAC.

Objective To analyze the efficacy and safety of double-ring sandwich procedure in the treatment of acute A-type aortic dissection root.Methods The clinical data of 103 patients with acute A-type aortic dissection treated by double-ring sandwich procedure in our center from October 2020 to May 2023 were retrospectively analyzed to investigate the surgical effect,short-term cardiac structural changes and short-term postoperative complications.Results Needle hemostasis was applied in 11.65％of all patients.The amount of red blood cell transfusion during the perioperative period was(2.95±1.97)U,plasma was(543.68±208.48)ml,and blood platelet was(0.08±0.30)U.The residual aortic regurgitation,cardiac function and pericardial effusion were significantly improved at 2 weeks after operation(P＜0.05).The proportion of residual false lumen in the aortic root was significantly reduced after operation(P＜0.05).The length of hospital stay,duration of intubation,and drainage within 24 hours after surgery were less.The incidence of postoperative short-term complications such as secondary thoracotomy,cerebral infarction,cerebral hemorrhage,hemofiltration,tracheal incision and death was low.Conclusions Double-ring sandwich procedure in the treatment of acute A-type aortic dissection can effectively block the false lumen of aortic root dissection,reduce the risk of aortic intimal avulsion,and the operation is safe and effective.

Objective　To analyze the identification of pathogenic bacteria in municipal sewage of Hangzhou City, Zhejiang Province from January to October 2023, to understand the serotype and drug resistance of Vibrio cholerae isolated from sewage, as well as to predict the virulence gene and drug resistance gene carrying situation. Methods From January to October 2023, urban sewage samples from various environments in Hangzhou City, Zhejiang Province, were continuously collected for bacterial isolation and culture. The serotypes of 27 Vibrio cholerae strains were identified by slide agglutination method, and the drug sensitivity test was conducted by micro broth dilution method. Whole genome sequence and bioinformatics software were used to predict drug resistance genes and virulence genes. Results The sewage identification results showed 26 bacteria genera, including Salmonella, Vibrio, Enterobacter, and Aeromonas, among 82 bacterial species. All 27 strains of Vibrio cholerae were non-O1 and non-O139 serogroups. The strains showed high resistance rates to ampicillin, ampicillin/sulbactam and cotrimoxazole at 59.26%, 14.81%, and 14.81%, respectively), exhibited high sensitivity to cefotaxime, tetracycline, chloramphenicol, meropenem, ertapenem, ceftazidime, ceftazidime/avibactam, amikacin, ciprofloxacin, tigecycline, and azithromycin. A total of 21 different drug resistance genes were detected in 11 strains of Vibrio cholerae, among which the highest carriage rate of β-lactam resistance genes reached 63.64%, and 1 strain carried 17 kinds of drug resistance genes. None of the 11 strains of Vibrio cholerae carried ctxA, ctxB, ace, zot, or chxA genes, but all the strains carried rtxB, rtxC, and rtxD genes; 90.91% of the strains carried hlyA, and 36.36% carried rtxA. Conclusions All Vibrio cholerae isolated from sewage in this study are non-O1 and non-O139 serogroups, showing good sensitivity to most antibiotics, but also they carry a certain number of drug-resistance genes and virulence genes. This suggests that future monitoring efforts should focus on these strains, providing certain data support for the study of the characteristics of Vibrio cholerae isolated from sewage.

Objective:To compare the clinical efficacies of O-arm combined with CT three-dimensional navigation system assisted screw placement versus manual screw placement in treating lower cervical fracture and dislocation.Methods:A retrospective cohort study was used to analyze the clinical data of 41 patients with lower cervical fracture and dislocation, who were treated in Honghui Hospital, Xi′an Jiaotong University from May 2021 to February 2022. The patients included 26 males and 15 females, aged 31.5-48.6 years [(41.5±15.0)years]. The injured segments were C 3 in 3 patients, C 4 in 12, C 5 in 13, C 6 in 10 and C 7 in 3. Nineteen patients were treated with cervical pedicle screws by O-shaped arm combined with CT three-dimensional navigation system (navigation group, 76 screws) and 22 by bare hands (traditional group, 88 screws). The total operation time, effective operation time, single nail placement time, single screw correction times, screw distance from anterior cortex, intraoperative blood loss, intraoperative fluoroscopic radiation dose, incision length and length of hospital stay were compared between the two groups, and the height of intervertebral space, Cobb angle, interbody slip distance and American Spinal injury Association (ASIA) grade were compared before operation and at 3 days after operation. Visual analogue score (VAS), Japanese Orthopedic Association (JOA) score, and neck dysfunction index (NDI) were evaluated before operation, at 3 days, 3 months after operation and at the last follow-up. Accuracy of screw placement and incidence of complications (adjacent facet joint invasion, infection, screw loosening) were detected as well. Results:All the patients were followed up for 11.1-13.9 months [(12.5±1.4)months]. The total operation time, intraoperative blood loss, intraoperative fluoroscopic radiation dose and incision length in the navigation group were more or longer than those in the traditional group (all P<0.05). The effective operation time, single nail placement time, single nail correction times and screw distance from anterior cortex in the navigation group were markedly less or smaller than those in the traditional group (all P<0.05). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). There were significant improvements in the height of intervertebral space, Cobb angle and interbody slip distance between the two groups at 3 days after operation (all P<0.05). There was no significant difference in the height of intervertebral space, Cobb angle, interbody slip distance or ASIA grade between the two groups before operation or at 3 days after operation (all P>0.05). Compared with pre-operation, the VAS, JOA score and NDI were significantly improved in both groups at 3 days, 3 months after operation and at the last follow-up (all P<0.05), with further improvement with time. There was no significant difference in VAS between the two groups before operation or at 3 months after operation (all P>0.05), but it was markedly lower in the navigation group compared with the traditional group at 3 days after operation and at the last follow-up (all P<0.05). There were no significant differences in JOA score or NDI between the two groups before operation or at 3 days and 3 months after operation (all P>0.05), but both were lower in the navigation group compared with the traditional group at the last follow-up (all P<0.05). The accuracies of placement of grade 0 and grade 0+1 screws were 92.0% (70/76) and 96.6% (73/76) in the navigation group, respectively, which were markedly higher than 88.7% (78/88) and 93.5% (82/88) in the traditional group (all P<0.05). The rates of adjacent facet joint invasion of A, B, and C degrees were 71.2% (54/76), 28.8% (22/76) and 0% (0/76) in the navigation group, respectively, while the invasion rates were 60.5% (53/88), 32.3% (28/88) and 7.3% (7/88) in the traditional group ( P<0.05). No screw loosening was noted in the navigation group, but the screw loosening rate was 9.1% (8/88) in the traditional group ( P<0.01). Conclusion:Compared with manual screw placement, O-arm combined with CT three-dimensional navigation system assisted screw placement for lower cervical fracture and dislocation has the advantages of shorter effective operation time, quicker screw placement, stronger screw holding force, better cervical stability, slighter postoperative pain, higher screw placement accuracy, and lower facet joint invasion and screw loosening rates.