Objective:To identify monoclonal antibody McAb2 recognizing epitope of Fba of GAS.Methods:The overlapped peptides were synthesized and their abilities to bind McAb2 were detected by dot-ELISA.The predominance amino acids specific for McAb2 were screened using phage 7 peptide library.Results:The result by dot-ELISA analysis demonstrated that the synthetized peptide,amino-acid residues 100-112~(th),could bind McAb2 with high affinity.The predominance amino acids specific for McAb2 were ITPDL,which was located in 100-110~(th)aa of Fba by panning with phage 7 peptide library.Conclusion:The domain and the predominance amino acids of Fba recognized by McAb2 is determined.The results would contribute to the research of the role of Fba on the pathogenic mechanism of GAS,the identification of function of McAb2,and the development of epitope-peptide vaccine.

Objective:To explore the distribution of pathogenic bacteria during perioperative period of kidney transplantation(KT)patients and examine drug resistance of major clinical pathogens to commonly used antibiotics to provide references for empirical medication of pathogenic bacteria infection after KT.Methods:From January 1, 2020 to June 30, 2021, 251 patients undergoing deceased donation KT on kidney transplant ward were selected.Clinical samples were collected and distribution and drug resistance of pathogenic bacteria examined for analyzing the incidence of possible donor-derived infections and predicting prognoses.Results:The detection rate of pathogens was 12.18%(367/3 014). A total of 225 non-repetitive strains were isolated.Gram-positive bacteria, Gram-negative bacteria and fungi accounted for 48.89%(110/225), 43.11%(97/225)and 8.00%(18/225). The proportion of lavage fluid in all isolated bacteria was 49.78%(112/225). And Staphylococcus epidermidis and Klebsiella pneumoniae predominated.Drainage fluid accounted for 24.88%(56/225)and Pseudomonas putida and Staphylococcus haemolyticus predominated.Urine accounted for 18.67%(42/225)with a dominance of Enterococcus faecium; blood accounted for 6.22%(14/225)with a dominance of S. epidermidis.All detected pathogens showed varying degrees of resistance.The resistance rates of E. faecium to ampicillin, vancomycin and linezolid were 93.33%(28/30), 6.45%(2/31)and 38.71%(12/31). The resistance rates of K. pneumoniae and Acinetobacter baumannii to carbapenems were 71.43%(20/28)and 80.00%(12/15). The incidence of possible donor-derived infection was 3.59%(9/251)and there was no mortality.Conclusions:The detection rate of pathogenic bacteria is high in KT patients during perioperative period.There is a diverse distribution of isolates of different specimen types and all detected pathogens show varying degrees of drug resistance.Clinicians should regularly analyze the distribution characteristics and causes of drug-resistant bacteria.And antibiotics should be optimized according to the results of drug sensitivity.

【Objective】 To study the effects of gestational diabetes (GDM) on morphological structure of brain tissue and microribonucleotide (miRNA) expression profile in neonatal mice, and to provide a new research target for the prevention and treatment of abnormal neurodevelopment in GDM progeny. 【Methods】 The pregnant mice were divided into model group and control group,each group consisted of 10 mice. The model group mice established a GDM model by injecting streptozotocin to measure fasting blood glucose (FPG) and random blood glucose (GLU) at different times. Successful molded mice were randomly divided into model group A and model group C, and control mice were divided into control group B and control group D, with 5 mice in each group. The newborn mice in groups A and B were used for hippocampal tissue GeneChip detection and brain morphology structure observation, and group C and D newborn mice were used for qRT-PCR detection of hippocampus tissue expression differences to verify the differentially expressed genes of miRANs obtained by GeneChip screening. After giving birth, the neonatal mice were sacrificed by decapitation, and the brain tissue was dissected to observe the overall morphological structure. The structural changes of hippocampus were observed under HE chromogenic microscope. The Agilent mouse miRNA oligonucleotide gene chip was used to detect the miRNA expression profile of mouse hippocampus, screen differential miRNAs and predict their target genes, and conduct GO analysis and signal transduction pathway analysis of target genes. The relative expression levels of the screened miRNAs were verified by qRT-PCR. 【Results】 Compared with the control group, the GLU increased significantly from the 3rd day after drug administration in the model group (P<0.01). Macroscopic observation of control group B mice had normal brain morphology and structure, smooth appearance, clear gyrus, close arrangement of hippocampus cell structure, uniform staining and complete structure; in model group A, the number of hippocampus cells decreased, loose arrangement and deep staining. In the initial screen of miRNA microarray, there were 11 differentially expressed miRNAs between control and model groups, all of which were downregulated miRNAs, including let-7b-5p、miR-130b-3p、miR-181c-5p、miR-181d-5p、miR-3099-3p、miR-3470a、miR-3473a、miR-3473b、miR-500-3p、miR-532-5p、miR-7047-5p(P<0.05). Two miRNAs (miR-3473b, miR-7047-75p) and 5 target genes (MAPK3, MAPK11, MAPK14, CALM3, AKT3). The relative expression of miR-3473b and miR-7047-5p in model group C were lower than that in control group D (t=19.13 and 6.24, P<0.05), and the validation results were consistent with the microarray test results. 【Conclusion】 Compared with the offspring of normal pregnant mice, GDM offspring mice have abnormal development of brain structure and damage of hippocampal nerve cells, and there are a large number of abnormal expression of miRNAs in hippocampal tissue. Differentially expressed miRNAs can be used as research targets for prevention and treatment of GDM offspring neurodevelopmental abnormalities.

ObjectiveTo observe the effect of aqueous extract of Sophorae Tonkinensis Radix et Rhizoma （STRR） on rheumatoid arthritis （RA） and to explore the anti-bone destruction mechanism based on phosphatidylinositol 3-kinase （PI3K）/serine/threonine-protein kinase （Akt） pathway. MethodHigh-performance liquid chromatography （HPLC） was used to determine the content of main active components in aqueous extract of STRR， and type Ⅱ collagen to induce RA （CIA） in mice. The blank group， model group， methotrexate （MTX） group （0.5 mg·kg^-1）， and low-dose （100 mg·kg^-1） and high-dose （200 mg·kg^-1） STRR aqueous extract groups were designed. Joint swelling was observed and clinical scores of CIA mice were calculated. Pathological changes of mouse joints were observed based on hematoxylin and eosin （HE） staining， and Micro-CT was performed to monitor joint destruction. TRAP staining was used to observe osteoclast formation in mouse joint， and Western blot to detect the expression of key proteins in PI3K/Akt signaling pathway in mouse joint tissue. ResultThe model group demonstrated higher degree of joint swelling， clinical scores of CIA， and degrees of synovial hyperplasia， inflammatory cell infiltration （P<0.01）， and joint destruction， more osteoclasts， and higher levels of matrix metallopeptidase-9 （MMP-9）， cathepsin K （CTSK）， nuclear factor of activated T-cells cytoplasmic 1 （NFATc1）， PI3K， and phosphorylated-Akt （p-Akt） proteins than the blank group （P<0.01）. Compared with the model group， the low-dose and high-dose aqueous extract of STRR alleviated joint swelling， reduced the clinical scores of CIA mice （P<0.05， P<0.01）， relieved the pathological changes of joint tissue （P<0.01） and joint destruction， decreased osteoclasts （P<0.05， P<0.01）， and lowered the levels of PI3K/Akt signaling pathway-related proteins in joint tissue of mice （P<0.01）. ConclusionThe aqueous extract of STRR can significantly delay the inflammatory response of RA and especially inhibit bone destruction by down-regulating the PI3K/Akt signaling pathway.