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Objective:To evaluate the relationship between the Panton-Valentine leukocidin (pvl) strain and clinical characteristics, and to describe the molecular biological characteristics of invasive Staphylococcus aureus ( S. aureus) infected clinical isolates. Methods:The isolates of S. aureus caused by invasive infection were collected in Beijing Children's Hospital Affiliated to Capital Medical University from January 2016 to December 2019, and the clinical data of the corresponding children were collected retrospectively using electronic medical records. Multilocus sequence typing, spa typing and pvl gene were analyzed using the PCR. In addition, the minimum inhibitory concentrations (MIC) of antibiotics of all isolates were detected by the micro-broth dilution method, and the isolates were divided into the pvl+ and pvl- groups according to whether or not the S. aureus isolates carried pvl. The t test and the Mann-Whitney U test were used to compare the clinical symptoms between the pvl+ and pvl- groups. Chi-square test was used to compare the drug susceptibility between the two isolates. Results:A total of 127 cases of invasive S. aureus infection were collected during the study period. The white blood cell count, neutrophil count, and C-reaction protein level in the pvl+ group were significantly higher than those in the pvl- group ( P=0.001, P=0.001, P=0.005). The rate of pvl carrier was 44.9%. Among 57 pvl+ pathogenic strains, 64.9% (37/57) were MRSA. The multidrug resistance rate of pvl- isolates was higher than that of pvl+ isolates (70% vs. 49.12%, P=0.02). Conclusions:In invasive S. aureus infection, pvl+ strain is associated with elevated inflammatory markers in children. the positive rate of pvl is higher in clinical isolates, and the multidrug resistance rate of pvl- S. aureus is higher.
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With the increasing understanding of the unique tumor microenvironment in the brain, immunotherapy have emerged as a new and promising treatment for brain metastases. Radiotherapy and immunotherapy have a synergistic effect, and it is of great value to understand its mechanism in the treatment of breast cancer brain metastases. At present, the study of immune checkpoint inhibitors combined with radiotherapy in breast cancer brain metastases is being actively carried out, bringing new hope to patients with breast cancer brain metastases.
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Objective:To investigate the molecular characteristic and antimicrobial resistance of Staphyloco- ccus aureus ( S. aureus) isolated from children with pneumonia, in order to provide the evidence for clinical diagnosis and treatment. Method:s The S. aureus strains isolated from children diagnosed as S. aureus pneumonia in the Beijing Children′s Hospital, Capital Medical University, between January 2016 and March 2017 were collected.Methicillin-resistant S. aureus(MRSA)and Methicillin-susceptible S. aureus(MSSA)were identified using the cefoxitin disc method and the detection of the mecA gene. S. aureus isolates were characterized by multilocus sequence typing (MLST) and Staphylococcal protein A (spa) typing, and MRSA strains were characterized by Staphylococcal chromosome cassette (SCC mec) typing.Besides, 21 superantigens (SAgs) genes, panton-valentine leucocidin (PVL) genes, adhesion genes fnbb and cna were detected by PCR; E-test was used to detect in vitro drug sensitivity of 14 antibiotics. Result:s A total of 42 S. aureus were collected, and 21 isolates were MSSA, the same to MRSA, while MSSA strains had relatively dispersed typing, with ST25-t078 (14.2%) as the most common one.ST59-SCC mecⅣa-t437 (71.4%) were the most predominant clones of MRSA.Of the 42 isolates, 36 strains (85.7%) had at least 1 superantigen gene, and sek- seq (21.4%) was the main virulence genotype.The ratio of pvl in MRSA strains (52.3%)was significantly higher than that in MSSA strains (14.2%), while the detection rate of fnbB and cna in MRSA(9.5%, 9.5%) was significantly lower than that in MSSA(42.8%, 47.6%), and the differences were statistically significant (all P<0.05). Ninety point four percent (38/42 strains) of the S. aureus isolates were multidrug resistant. Conclusions:In children with S. aureus pneumonia, MRSA has a high detection rate, and its dominant clonotype is ST59-SCC mecⅣa-t437.The pre-valence of superantigen genes and the multidrug resistant rate of S. aureus are relatively high.MRSA strains often carry pvl, while MSSA strains usually carry fnbB and cna gene.
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Objective:To explore the predictive value of a radiomics model based on preoperative contrast enhanced MRI in the assessment of the isocitrate dedydrogenase 1 (IDH 1) genotype in high-grade glioma.Methods:A retrospective analysis was performed on a dataset including 182 patients with high-grade glioma confirmed by surgical pathology between December 2012 and January 2018 in the Affiliated Hospital of Qingdao University. There were 79 patients with IDH1-mutant glioma (45 cases with WHO grade Ⅲ, 34 with WHO grade Ⅳ) and 103 with IDH 1 wild-type glioma (33 cases with WHO grade Ⅲ, 70 cases with WHO grade Ⅳ). All patients had complete preoperative brain contrast enhanced MRI.The cases were divided into a training dataset and a validation dataset at a ratio of 7∶3 using stratified random sampling. Radiomic features were initially extracted using A.K (Analysis Kit, GE healthcare) software, and were selected and excluded using Kruskal-Wallis and Spearman analyses. Using R softwear " GLM" function, the Lasso-logistic model was finally conducted to obtain the optimized subset of the feature to build the radiomics model, and the model was then tested with cross-validation. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the performance of the model in differentiating IDH1-mutant type and wild-type gliomas.Results:The radiomics model showed good performance in IDH genotype differentiation in both the training dataset (AUC 0.870, 95% CI: 0.754 to 0.855, accuracy rate 79.8%, sensitivity 85.5%, specificity 75.4%, positive predictive value 0.734, negative predictive value 0.867) and the validation dataset (AUC 0.860, 95% CI: 0.690 to 0.913, accuracy rate 78.9%, sensitivity 91.3%, specificity 69.0%, positive predictive value 0.700, negative predictive value 0.909).Conclusion:The radiomics model based on the preoperative enhanced MR can provide a way to predict the IDH1 genotype in high-grade gliomas.
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Objective To explore the value of contrast?enhanced T1 mapping technique in differentiating between recurrence and radiation necrosis of brain metastases after gamma knife treatment. Methods From March 2016 to June 2017,56 patients with brain metastases treated by gamma knife and confirmed by pathology or follow?up in Shandong Provincial Hospital were prospectively collected. Routine MRI and contrast?enhanced T1 mapping sequence scan were performed. T1 value was obtained 5 mins (T1 5 min) and 60 mins (T1 60 min) after injection of contrast agent. The Differences betweenT1 60 min and T1 5 min (T1 differ) was calculated,and relative cerebral blood volume (rCBV) value was obtained. Patients were divided into radiation necrosis group and tumor recurrence group according to imaging follow?up results or pathological results. Two?sides unpaired t test was used to compare the differences in T1 5 min,T1 60 min,T1 differ and rCBV between the 2 groups. Pearson correlation analysis was used to evaluate the correlation between T1 differ and rCBV, and the receiving operating curve (ROC) was used to evaluate the diagnostic efficiency of MRI quantitative parameters,and Z test was used to compare the differences of area under curve (AUC) between T1 differ and rCBV values. Results Of the 56 patients,27 had tumor recurrence and 29 had radiation necrosis. The differences in T1 5 min,T1 60 min,T1 differ and rCBV between the 2 groups was statistically significant (P<0.05). T1 differ and rCBV values were significantly correlated, r=0.58, P<0.01. The differential diagnosis of AUC between radiation necrosis and tumor recurrence were 0.66,0.73,0.97 and 0.95 respectively in T1 5 min,T1 60 min, T1 differ and rCBV, and there was no significant differences between AUC in T1 differ and rCBV (P=0.274). Conclusion The contrast?enhanced T1 mapping image can be used for differential diagnosis between radiation necrosis and recurrence after gamma knife treatment of brain metastases. T1 differ value has high differential efficiency.
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Objective@#To study the clinical and molecular characteristics of Staphylococcus aureus(S.aureus ) isolated from neonates of Beijng Children′s Hospital.@*Methods@#The clinical information of S. aureus infection in newborns of Beijing Children′s Hospital from February 2016 to January 2017 was collected.The molecular biological characteristics of S. aureus isolates were detected.Methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus(MSSA)were identified, using the cefoxitin disc method and the detection of the mecA gene.Multilocus sequence typing(MLST)and spa typing were analyzed using the PCR, and the staphylococcal chromosomal cassette mec(SCCmec) type was analyzed for the MRSA isolates.Eleven adhesion gene and three virulence genes(pvl, psma, hlα )were also detected by PCR.Antimicrobial susceptibility testing was performed by agra dilution method or E-test method.@*Results@#The total of 57 cases of neonatal S. aureus infection were collected during the study.The most common clinical diagnosis was 38 cases (66.7%) of pneumonia and 28 cases (49.1%) of skin infection syndrome (SSTI). There were 31 cases (54.4%) with MRSA infection and 26 cases (45.6%) with MSSA infection.The proportion of SSTI in the MRSA group (64.5%) and the infection of more than 2 sites (61.3%, 19/31) were significantly higher than those in the MSSA group (30.8%, 8/26 and 23.1%, 6/31). There were 16 MLST types and 29 spa types, the most common ones were ST59 (40.4%) and t437 (33.33%), respectively.The most common popular clones of MRSA and MSSA were ST59-SCCmecIVa-t437 (54.8%) and ST22-t309, respectively(11.5%). The sdrE carrying rate of MRSA was higher than that of MSSA, while the sdrD and cna carrying rates were lower than those of MSSA (P<0.05). The other adhesion and virulence gene carrying rates were not significantly different between the two strains.The multi-drug resistance rate of all strains was 61.4%(35/57). Except for lactam antibiotics, the most common resistant phenotypes of MRSA and MSSA were ERY-CLI, accounting for 74.2% and 26.9%, respectively.@*Conclusion@#The main types of neonatal S. aureus infection in our hospital were pneumonia and SSTI.SSTI and multi-site infections of MRSA infection are more common.MRSA and MSSA isolates have clonal dissemination characteristics.The most common clones are ST59-SCCmecIVa-t43 and ST22-t309, which show no significant differences in the status of carrying virulence factors between them.The multi-drug resistance rate of neonatal S. aureus isolates is higher.
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Objective To investigate the molecular characteristics,virulence genes and antimicrobial susceptibility to Staphylococcus aureus strains isolated from children with skin and soft tissue infections (SSTIs) in Beijing.Methods A total of 52 Staphylococcus aureus isolates were collected from children with SSTIs in Beijing Children's Hospital,Capital Medical University,and the clinical data were collected and analyzed.Methicillin-resistant Staphylococcus aureus(MRSA) and methicillin-susceptible Staphylococcus aureus(MSSA) were identified by using the cefoxitin disc method and the detection of mecA gene.Multilocus sequence typing (MLST) and staphylococcal protein A (spa) typing were analyzed by the PCR method,and the staphylococcal chromosomal cassette mec (SCCmec) type was analyzed for the MRSA isolates.The pvl,eta,etb,tsst-1 and hlg genes were also detected by PCR.The susceptibility strains to 16 antibiotics were evaluated by using the agar dilution method.Results A total of 52 Staphylococcus aureus SSTIs patients,30 with MRSA infections and 22 with MSSA infections were included in the study.There were 23 patients (44.2％) less than 1 year old.The most frequent infections were the newborn omphalitis (12/52 strains,23.1％)and abscess(11/52 strains,21.2％).ST59-MRSA-SCCmecⅣa-t437 was the most predominant clones of MRSA isolates.Among the MSSA isolates(14/30 strains,46.7％),no significant epidemic clone was found.Ten sequence types (STs) and 14 spa types were identified in MSSA,and the most common types were ST22(6/22 strains,27.3％)and t309 (5/22 strains,22.7％),respectively.Notably,the multidrug resistant rates of MRSA and MSSA isolates were all ＞ 85％.The percentages of the Staphylococcus aureus SSTIs strains resistant to Erythromycin,Penicillin,Chloramphenicol and Clindamycin were 100.0％,94.2％,69.2％ and 63.5％,respectively.The tested isolates were susceptible to Trimethoprim/Sulfamethoxazole,Mupirocin,Fusidic acid,Tigecycline,Linezolid and Vancomycin.The pvl gene's positive rate was 40.4％,and no significant difference between MRSA and MSSA was observed (P ＞ 0.05).Eta and etb genes were detected in 2 patients with staphylococcal scalded skin syndrome.Conclusions The Staphylococcus aureus SSTIs strains are most frequently isolated from newborn omphalitis and abscess in Beijing.The multidrug resistant rate is relatively high,so the erythromycin and clindamycin should not be preferred in empiric treatment of children with Staphylococcus aureus SSTIs.The prevalence of pvl gene is 40.1％.ST59-MRSA-SCCmecⅣa-t437 is the common clone of MRSA,while the MSSA isolates have a more diverse genetic background.
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BACKGROUND: Revascularization is a challenge for the tissue-engineered bone carrying cells after implanted into human body. Previous studies have found that tanshinol can improve the functions of endothelial progenitor cells and exert vascular protective effects.OBJECTIVE: To prepare the β-calcium phosphate (β-TCP) scaffold with tanshinol coating, and to observe its cytocompatibility.METHODS: The β-TCP scaffolds coated with 10-7, 10-6 and 10-5 mol of tanshinol were constructed by negative pressure absorption method. The distribution of tanshinol coating on the scaffold was observed using scanning electron microscopy,and the inner ingredients were analyzed by infrared spectrum. Human endothelial progenitor cells (hEPCs) were cultured in the extracts of β-TCP and β-TCP scaffolds with 10-7, 10-6, 10-5 mol of tanshinol coatings, respectively. The cell proliferation was detected at 2, 4, 6, 8 and 10 days of culture; the levels of nitric oxide and vascular endothelial growth factor in the supernatants were detected at 1, 7 and 14 days of culture; the lumen formation on the matrigel was observed after 14-day culture. hEPCs were respectively seeded onto the β-TCP and β-TCP scaffolds with different dosages of tanshinol coating,and then the cell growth was observed under scanning electron microscope at 7 days.RESULTS AND CONCLUSION: The tanshinol coating evenly distributed on the inner surface of the pores, and its crystalline structure became dense with dosage increasing. Infrared spectrum analysis revealed no changes in the characteristic absorption peak of tanshinol and TCP in the scaffold. The β-TCP scaffolds with tanshinol coating could promote the proliferation of hEPCs, especially the scaffolds with 10-6 and 10-5 mol tanshinol coating. Compared with the β-TCP scaffold, the scaffolds with 10-6 and 10-5 mol tanshinol coating significantly upregulated the nitric oxide level at 14 days of culture, and significantly increased the level of vascular endothelial growth factor at 7 and 14 days of culture (P <0.05). Although it could be found in all β-TCP scaffolds with tanshinol coating, the lumen formation was the maturest in the scaffold with 10-5 mol tanshinol coating. These results suggest the β-TCP scaffolds with tanshinol coating can promote the proliferation and endothelial differentiation of hEPCs, and hold a good cytocompatibility.
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BACKGROUND: There are various methods to observe and detect early angiogenesis in the process of entochondrostosis, but each holds certain deficiencies.OBJECTIVE: To explore the possibility of tetracycline and alizarin complexone as an indirect marker ofangiogenesis in the process of entochondrostosis.METHODS: New Zealand white rabbit models of bilateral radial bone defects were prepared, followed by β-tricalcium phosphate implantation, and then given the injection of tetracycline and alizarin complexone at 1 and 15 days,respectively. Samples were collected at 28 days, some of which were observed using fluorescence/light microscope after ink perfusion and hard tissue slicing, and the others were decalcified and observed using immunohistochemistry. The uniformity between lumen structures labeled with bone affinity fluorescein and vascular structures marked by immunohistochemistry and ink perfusion was compared.RESULTS AND CONCLUSION: The lumen structure labeled with bone affinity fluorescein was confirmed to be a CD34 positive vascular structure. Under the fluorescence microscope, the bone affinity fluorescein labeled vascular morphology was consistent with ink perfusion-labeled, and black ink lines could be observed in the lumen structures labeled with bone affinity fluorescein after ink perfusion. In addition, the color of the lumen labeled with fluorescein was more gorgeous,three-dimensional structure more vivid, and the vascular evolution process distinguished more easily by different fluorescein colors, exhibiting unique advantages. Therefore, it is available to detect the early angiogenesis in the process of entochondrostosis.
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Objective To study the molecular characteristics of the Staphylococcus aureus isolated from the intensive care units (ICUs) of children's hospital.Methods From January 2016 to December 2016,a total of 39 S.aureus strains were collected and identified from various clinical specimens that were obtained from patients who were confined in the neonatal and pediatric ICUs of Beijing Childreng Hospital.Methicillin-resistant S.aureus (MRSA) and methicillin-susceptible S.aureus (MSSA) were identified using the cefoxitin disc method and the detection of the mecA gene.Multilocus sequence typing (MLST) and spa typing were analyzed using the PCR,and the staphylococcal chromosomal cassette mec (SCCmec) type was analyzed for the MRSA isolates.Twenty-one superantigen genes and the Panton-Valentine leukocidin (pvl) gene were also detected by PCR.Their susceptibility to 12 antibiotics was evaluated using the E-test method.The differences in prevalence of virulence genes and antimicrobial resistance were compared between the MRSA and MSSA isolates by Fisherg exact test.Results All the S.aureus strains were isolated from secretion inside the airway of pneumonia (including severe pneumonia),the blood of patients with bacteremia,and exudate of skin and soft tissue infections.ST59-SCCmecⅣa-t437 (55.6％) and ST398-t571 (28.6％) were the most predominant clones of MRSA and MSSA,respectively.Of the 39 isolates,26 strains (66.7％) had at least one superantigen gene,and seb (38.5％),sek (30.8％),and seq (20.5％) were the most common genes;seb-sek-seq (18.0％) was the main virulence genotype.The pvl geneg positive rate was 25.6％,and no significant difference between MRSA and MSSA was observed (P ＞ 0.05).Notably,79.9％ of the S.aureus isolates were multidrug resistant,and 94.9％,53.8％,and 51.3％ of the isolates were resistant to erythromycin,clindamycin,and chloramphenicol,respectively.The tested isolates were susceptible to trimethoprim/sulfamethoxazole,rifampicin,and vancomycin.Conclusions The S.aureus strains from the ICUs of childreng hospital were isolated from the secretion inside the airway of pneumonia (including severe pneumonia),the blood of patients with bacteremia,and exudate of skin and soft tissue infections.ST59-SCCmecⅣa-t437 (55.6％) and ST398-t571 (28.6％) were the common clones of MRSA and MSSA,respectively.The prevalence of superantigen genes and the multidrug resistant rate were relatively high.
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<p><b>OBJECTIVE</b>To investigate the effects of activation of the GLP-1 receptor on the p38MAPK signaling pathway in hepatic stellate cells (HSCs).</p><p><b>METHODS</b>HSCs were isolated and identified according to morphological features; the levels of GLP-1R protein were determined by western blotting.The HSCs were randomly divided into a control grouP (normal saline treatment) and experimental grouP(liraglutide treatment); after 120 hours, the expression of p38MAPK mRNA was examined by RT-PCR and of phosphorylated (p)-p38MAPK protein was detected by western blotting.</p><p><b>RESULTS</b>GLP-1R proteins were detected in the HSCs. Compared with the control group, the experimental group showed significantly decreased p38MAPK mRNA and p-p38MAPK protein (both P < 0.01).</p><p><b>CONCLUSION</b>The p38MAPK signaling pathway could be down-regulated when GLP-1R is activated in HSCs.</p>
Subject(s)
Humans , Cells, Cultured , Glucagon-Like Peptide 1 , Pharmacology , Glucagon-Like Peptide-1 Receptor , Hepatic Stellate Cells , Metabolism , Liraglutide , MAP Kinase Signaling System , RNA, Messenger , Receptors, Glucagon , Metabolism , p38 Mitogen-Activated Protein Kinases , MetabolismABSTRACT
Staphylococcus aureus can cause a broad variety of infections, ranging from minor infections of the skin to serious necrotic pneumonia. Pathogenicity and high degree of multi-drug resistance are the characteristics of the methicillin-resistant Staphylococcus aureus ( MRSA ). The cause of resistance to methicillin and all other β-lactam antibiotics is the mecA gene, which is situated on a mobile genetic element, the staphylococcal cassette chromosome mec (SCCmec). Eight major variants of SCCmec, type Ⅰ to Ⅷ, are distinguished. This paper describes the structure and typing of SCCmec, its discovery, detection methods and distributiong are reviewed.