Objective To construct a lentiviral vector for overexpression of bone morphogenetic protein 7(BMP7)in mice,and the effect of BMP7 overexpression on the expression of Jagged1 in mouse aortic endothelial cells and the calcification of the co-cultured vascular smooth muscle cells(VSMCs)were analyzed.Methods According to the target gene information Mouse-BMP7(NM_007557.3)and plasmid information pLVX-zsGreen-C1,gene sequence synthesis was carried out to construct BMP7 overexpression lentivirus.The efficiency of BMP7 overexpression lentivirus infection was detected by qPCR;the expression of Jagged1 protein in aortic endothelial cells from infected mice was detected by Western blot.The endothelial cells with lentivirus overexpressing BMP7 were co-cultured with VSMCs,and the calcification of VSMCs was observed by alizarin red staining.Results BMP7 overexpression lentiviral vector was successfully constructed and transfected into aortic endothelial cells.qPCR test results showed that the expression level of BMP7 mRNA was significantly increased in the BMP7 overexpression group than that in the normal control group(P<0.01),while there was no significant difference in the expression of BMP7 mRNA between the empty vector control group and the normal control group(P>0.05).Western blot results showed that the expression level of Jagged1 protein in endothelial cells of mouse in the BMP7 overexpression group was significantly lower than that in the normal control group(P<0.01),while there was no significant difference in the expression level of Jagged1 protein in endothelial cells between the empty vector control group and the normal control group(P>0.05).The results of alizarin red staining showed that the calcification of VSMCs was significantly increased after co-cultured with endothelial cells infected with BMP7 lentivirus.Conclusion Mouse BMP7 overexpression lentiviral vector was successfully constructed,and overexpression of BMP7 can reduce the expression of Jagged1 in mouse aortic endothelial cells and promote the calcification of co-cultured VSMCs.

Objective To investigate the potential value of exosomes derived from rat ectoderm mesenchymal stem cells(EMSCs-exo)for repairing secondary spinal cord injury.Methods EMSCs-exo were obtained using ultracentrifugation from EMSCs isolated from rat nasal mucosa,identified by transmission electron microscope,nanoparticle tracking analysis(NTA),and Western blotting,and quantified using the BCA method.Neonatal rat microglia purified by differential attachment were induced with 100 μg/L lipopolysaccharide(LPS)and treated with 37.5 or 75 mg/L EMSCs-exo.PC12 cells were exposed to 400 μmol/L H2O2 and treated with EMSCs-exo at 37.5 or 75 mg/L.The protein and mRNA expressions of Arg1 and iNOS in the treated cells were determined with Western blotting and qRT-PCR,and the concentrations of IL-6,IL-10,and IGF-1 in the supernatants were measured with ELISA.The viability and apoptosis of PC12 cells were detected using CCK-8 assay and flow cytometry.Results The isolated rat EMSCs showed high expressions of nestin,CD44,CD105,and vimentin.The obtained EMSCs-exo had a typical cup-shaped structure under transmission electron microscope with an average particle size of 142 nm and positivity for CD63,CD81,and TSG101 but not vimentin.In LPS-treated microglia,EMSCs-exo treatment at 75 mg/L significantly increased Arg1 protein level and lowered iNOS protein expression(P<0.05).EMSCs-exo treatment at 75 mg/L,as compared with the lower concentration at 37.5 mg/L,more strongly increased Arg1 mRNA expression and IGF-1 and IL-10 production and decreased iNOS mRNA expression and IL-6 production in LPS-induced microglia,and more effectively promoted cell survival and decreased apoptosis rate of H2O2-induced PC12 cells(P<0.05).Conclusion EMSCs-exo at 75 mg/L can effectively reduce the proportion of M1 microglia and alleviate neuronal apoptosis under oxidative stress to promote neuronal survival,suggesting its potential in controlling secondary spinal cord injury.

Objective To develop an intelligent horizontal rotating cell culture device with high modularity,easy operation,easy disinfection,low cost and high stability.Methods The cell culture device consisted of a rotating culture module,a dirve module,a control module and control software,with the shells of all the modules being manufactured by 3D printing.The rotating culture module was composed of a tubular electrospun scaffold,a cell culture chamber,a magnetic coupling rotor and polypropylene pipeline;the drive module was made up of a N20 reduction motor and a magnetic coupling rotor;the control module included an ESP-8266 chip and a printed circuit board;the control software was developed with Blinker IoT platform and C++language.The device was used to culture human intrahepatic bile duct epithelial cells to verify its effects.Results Light microscopy and scanning electron microscopy images showed that a uniform and continuous cell layer was formed on the surface of the tubular electrospun scaffold.Conclusion The intelligent horizontal rotating cell culture device achieves uniform growth of cells on the inner surface of tubular electrospun scaffolds,and can be used as an effective platform for cell culture on tubular scaffolds.[Chinese Medical Equipment Journal,2024,45(9):41-45]

Objective:To investigate the application effect of 3D printed fetal heart model based on ultrasound data combined with case-based learning (CBL) in prenatal ultrasound teaching of complex heart malformations in standardized residency training of ultrasound medicine.Methods:A total of 60 students majoring in ultrasound imaging who received standardized residency training in Ultrasonography Center of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, from September 2020 to August 2022 were enrolled as subjects and divided into experimental group and control group, with 30 students in each group. The students in the experimental group received teaching with 3D printed fetal heart model and CBL teaching, and those in the control group received teaching with hand-painted heart diagram and CBL teaching. The two groups were compared in terms of the score of theoretical examination, the degree of satisfaction with teaching, and the self-rated score of the understanding of each disease before and after teaching, and the correlation of the increase in score with case complexity was also analyzed. MedCalc software was used to perform the t-test and the linear regression analysis. Results:The experimental group had a significantly higher score of theoretical examination than the control group [(85.70±8.70) vs. (71.40±9.50)]. The questionnaire survey showed that the experimental group had better feedbacks than the control group in the aspects such as the degree of satisfaction with teaching ( P<0.05). After the implementation of this teaching model, compared with the control group, the experimental group had significantly higher self-rated scores of the understanding of case 2, case 3, case 4, and case 5 ( P<0.05). The increase in score after teaching was positively correlated with the complexity score of abnormal cases ( R2=0.90, P=0.010; R2=0.94, P=0.010), and the experimental group tended to have a greater regression coefficient. Conclusions:The reasonable application of 3D printed fetal heart model combined with CBL teaching in fetal heart teaching in standardized residency training of ultrasound medicine can help the students to understand and enhance the knowledge of cardiac anatomy, improve the learning experience of fetal echocardiography, and deepen the understanding and awareness of complex congenital heart disease.

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Methamphetamine abuse is a major public health problem in the world,and in recent years,methamphetamine is also the most abused synthetic drug in China.The neurotoxic or addiction mechanism of methamphetamine has not been fully clarified,and there is still a lack of specific withdrawal methods and drugs for methamphetamine abuse.Mitochondria are not on-ly the organelles to which methamphetamine directly produces toxic effects,but also participate in regulating the neurotoxic damage process of methamphetamine.Mitochondrial quality is the regulatory basis for maintaining mitochondrial homeostasis and is regulated by three main mechanisms,which are mitochon-drial biogenesis,mitochondrial dynamic,and mitophagy.This review summarizes the research progress of mitochondrial quality control in methamphetamine-induced neurotoxicity,which may provide theoretical support for further research on the mechanism of methamphetamine neurotoxicity and development the mito-chondria-targeting drugs.

Objective To investigate the potential value of exosomes derived from rat ectoderm mesenchymal stem cells(EMSCs-exo)for repairing secondary spinal cord injury.Methods EMSCs-exo were obtained using ultracentrifugation from EMSCs isolated from rat nasal mucosa,identified by transmission electron microscope,nanoparticle tracking analysis(NTA),and Western blotting,and quantified using the BCA method.Neonatal rat microglia purified by differential attachment were induced with 100 μg/L lipopolysaccharide(LPS)and treated with 37.5 or 75 mg/L EMSCs-exo.PC12 cells were exposed to 400 μmol/L H2O2 and treated with EMSCs-exo at 37.5 or 75 mg/L.The protein and mRNA expressions of Arg1 and iNOS in the treated cells were determined with Western blotting and qRT-PCR,and the concentrations of IL-6,IL-10,and IGF-1 in the supernatants were measured with ELISA.The viability and apoptosis of PC12 cells were detected using CCK-8 assay and flow cytometry.Results The isolated rat EMSCs showed high expressions of nestin,CD44,CD105,and vimentin.The obtained EMSCs-exo had a typical cup-shaped structure under transmission electron microscope with an average particle size of 142 nm and positivity for CD63,CD81,and TSG101 but not vimentin.In LPS-treated microglia,EMSCs-exo treatment at 75 mg/L significantly increased Arg1 protein level and lowered iNOS protein expression(P<0.05).EMSCs-exo treatment at 75 mg/L,as compared with the lower concentration at 37.5 mg/L,more strongly increased Arg1 mRNA expression and IGF-1 and IL-10 production and decreased iNOS mRNA expression and IL-6 production in LPS-induced microglia,and more effectively promoted cell survival and decreased apoptosis rate of H2O2-induced PC12 cells(P<0.05).Conclusion EMSCs-exo at 75 mg/L can effectively reduce the proportion of M1 microglia and alleviate neuronal apoptosis under oxidative stress to promote neuronal survival,suggesting its potential in controlling secondary spinal cord injury.

Objective:To investigate the effect of serine/arginine-rich splicing factor 2 (SRSF2) on ferroptosis and its possible mechanism in glioblastoma cells.Methods:The online database of gene expression profiling interactive analysis 2 (GEPIA 2) and Chinese Glioma Genome Atlas were used to analyze the expression of SRSF2 in glioblastoma tissue and its association with patients prognosis. To validate the findings of the online databases, the pathological sections of glioblastoma and non-tumor brain tissues from Tianjin Medical University General Hospital, Tianjin, China were collected and analyzed by using immunohistochemistry. Silencing SRSF2 gene expression in glioblastoma cells by siRNA was analyzed with Western blot. The proliferation index was detected by using CCK8 assay. The rescued experiment was conducted by using expression plasmid of pcDNA3.1(+)-SRSF2. The activity of ferroptosis was assessed by using the levels of iron ions and malondialdehyde in glioblastoma cells and the changes in the ratio of glutathione to oxidized glutathione. The changes of gene expression and differential pre-mRNA alternative splicing (PMAS) induced by SRSF2 were monitored by using the third-generation sequencing technology analysis, namely Oxford nanopore technologies (ONT) sequencing analysis.Results:SRSF2 expression was higher in glioblastoma tissues than non-tumor brain tissues. Immunohistochemistry also showed a positive rate of 88.48%±4.60% in glioblastoma tissue which was much higher than the 9.97%±4.57% in non-tumor brain tissue. The expression of SRSF2 was inversely correlated with overall and disease-free disease survivals ( P<0.01). The proliferation index of glioblastoma cells was significantly reduced by silencing with SRSF2 siRNA ( P<0.01) and could be reversed with transfection of exogenous SRSF2. The levels of intracellulariron ions and malondialdehyde increased ( P<0.05), but the glutathione/oxidized glutathione ratio and the expression of key proteins in the glutathione pathway remained unchanged ( P>0.05). ONT sequencing results showed that silencing SRSF2 in glioblastoma cells could induce a significant alternative 3' splice site change on ferroptosis suppressor protein 1 (FSP1). Conclusion:SRSF2 inhibits the ferroptosis in glioblastoma cells and promotes their proliferation, which may be achieved by regulating FSP1 PMAS.

Objective:To explore potential predictors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in early stage. Methods:The prospective multicenter study was conducted in Zhejiang, China from May 1 st, 2019 to January 31 st, 2020. A total of 1 428 patients with fever >48 hours to <120 hours were studied. Their clinical data and oral pharyngeal swab samples were collected; Mycoplasma pneumoniae DNA in pharyngeal swab specimens was detected. Patients with positive Mycoplasma pneumoniae DNA results underwent a series of tests, including chest X-ray, complete blood count, C-reactive protein, lactate dehydrogenase (LDH), and procalcitonin. According to the occurrence of RMPP, the patients were divided into two groups, RMPP group and general Mycoplasma pneumoniae pneumonia (GMPP) group. Measurement data between the 2 groups were compared using Mann-Whitney U test. Logistic regression analyses were used to examine the associations between clinical data and RMPP. Receiver operating characteristic (ROC) curves were used to analyse the power of the markers for predicting RMPP. Results:A total of 1 428 patients finished the study, with 801 boys and 627 girls, aged 4.3 (2.7, 6.3) years. Mycoplasma pneumoniae DNA was positive in 534 cases (37.4%), of whom 446 cases (83.5%) were diagnosed with Mycoplasma pneumoniae pneumonia, including 251 boys and 195 girls, aged 5.2 (3.3, 6.9) years. Macrolides-resistant variation was positive in 410 cases (91.9%). Fifty-five cases were with RMPP, 391 cases with GMPP. The peak body temperature before the first visit and LDH levels in RMPP patients were higher than that in GMPP patients (39.6 (39.1, 40.0) vs. 39.2 (38.9, 39.7) ℃, 333 (279, 392) vs. 311 (259, 359) U/L, both P<0.05). Logistic regression showed the prediction probability π=exp (-29.7+0.667×Peak body temperature (℃)+0.004×LDH (U/L))/(1+exp (-29.7+0.667×Peak body temperature (℃)+0.004 × LDH (U/L))), the cut-off value to predict RMPP was 0.12, with a consensus of probability forecast of 0.89, sensitivity of 0.89, and specificity of 0.67; and the area under ROC curve was 0.682 (95% CI 0.593-0.771, P<0.01). Conclusion:In MPP patients with fever over 48 to <120 hours, a prediction probability π of RMPP can be calculated based on the peak body temperature and LDH level before the first visit, which can facilitate early identification of RMPP.