Outer membrane vesicles (OMVs) are nanoscale vesicles secreted by Gram-negative bacteria. As a unique bacterial secretion, OMV secretion can help bacteria maintain the outer membrane stability or remove harmful substances. Studies have shown that local separation of outer membrane and peptidoglycan layers led by abnormalities in outer membrane protein function, abnormal structure or excessive accumulation of LPS, and erroneous accumulation of phospholipids in the outer leaflet, which can all lead to bacterial outer membrane protrusion and eventually bud formation of OMVs. Since OMVs are mainly composed of bacterial outer membrane and periplasmic components, the pathogen associated molecular patterns (PAMPs) on their surface can trigger strong immune responses. For example, OMVs can recruit and activate neutrophils, polarize macrophages to secrete large amounts of inflammatory factors. More importantly, OMVs can act as adjuvants to induce dendritic cell (DC) maturation to enhance adaptive immune response in the body. At the same time, OMVs are derived from bacteria, which make it easy to modify. The methods by genetic engineering and others can improve their tumor targeting, give them new functions, or reduce their immunotoxicity, which is conducive to their application in tumor therapy. OMVs not only induce apoptosis or pyroptosis of tumor cells, but also regulate the host immune system, which makes OMVs themselves have a certain killing effect on tumors. In addition, the tendency of neutrophils to inflammatory tumor sites and the formation of neutrophil extracellular traps enable OMVs to target tumor sites, and the suitable size and the characteristic that they are easily taken up by DCs give OMVs a certain lymphatic targeting ability. Therefore, OMVs are often employed as excellent drug or vaccine carriers in tumor therapy. This review mainly discusses the biological mechanism of OMVs, the regulatory effects of OMVs on immune cells, the functional modification strategies of OMVs, and their research progress in tumor therapy.

Objective This study aimed to evaluate whether the onset of the plateau phase of slow hepatitis B surface antigen decline in patients with chronic hepatitis B treated with intermittent interferon therapy is related to the frequency of dendritic cell subsets and expression of the costimulatory molecules CD40,CD80,CD83,and CD86. Method This was a cross-sectional study in which patients were divided into a natural history group(namely NH group),a long-term oral nucleoside analogs treatment group(namely NA group),and a plateau-arriving group(namely P group).The percentage of plasmacytoid dendritic cell and myeloid dendritic cell subsets in peripheral blood lymphocytes and monocytes and the mean fluorescence intensity of their surface costimulatory molecules were detected using a flow cytometer. Results In total,143 patients were enrolled(NH group,n = 49;NA group,n = 47;P group,n = 47).The results demonstrated that CD141/CD1c double negative myeloid dendritic cell(DNmDC)/lymphocytes and monocytes(%)in P group(0.041[0.024,0.069])was significantly lower than that in NH group(0.270[0.135,0.407])and NA group(0.273[0.150,0.443]),and CD86 mean fluorescence intensity of DNmDCs in P group(1832.0[1484.0,2793.0])was significantly lower than that in NH group(4316.0[2958.0,5169.0])and NA group(3299.0[2534.0,4371.0]),Adjusted P all<0.001. Conclusion Reduced DNmDCs and impaired maturation may be associated with the onset of the plateau phase during intermittent interferon therapy in patients with chronic hepatitis B.

Objective To explore characteristics of clinical parameters and cytokines in patients with drug-induced liver injury(DILI)caused by different drugs and their correlation with clinical indicators. Method The study was conducted on patients who were up to Review of Uncertainties in Confidence Assessment for Medical Tests(RUCAM)scoring criteria and clinically diagnosed with DILI.Based on Chinese herbal medicine,cardiovascular drugs,non-steroidal anti-inflammatory drugs(NSAIDs),anti-infective drugs,and other drugs,patients were divided into five groups.Cytokines were measured by Luminex technology.Baseline characteristics of clinical biochemical indicators and cytokines in DILI patients and their correlation were analyzed. Results 73 patients were enrolled.Age among five groups was statistically different(P=0.032).Alanine aminotransferase(ALT)(P=0.033)and aspartate aminotransferase(AST)(P=0.007)in NSAIDs group were higher than those in chinese herbal medicine group.Interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-α)in patients with Chinese herbal medicine(IL-6:P<0.001;TNF-α:P<0.001)and cardiovascular medicine(IL-6:P=0.020;TNF-α:P=0.001)were lower than those in NSAIDs group.There was a positive correlation between ALT(r=0.697,P=0.025),AST(r=0.721,P=0.019),and IL-6 in NSAIDs group. Conclusion Older age may be more prone to DILI.Patients with NSAIDs have more severe liver damage in early stages of DILI,TNF-α and IL-6 may partake the inflammatory process of DILI.

Objective:To investigate the clinical value of prospective ECG-gated high-pitch protocol scanning of third generation DSCT in the diagnosis of pediatric congenital heart disease (CHD).Methods:A total of 243 children with confirmed CHD who were expected to undergo surgical treatment were prospectively collected and randomly divided evenly into 3 groups, with first group for prospective ECG-gated high-pitch scanning in third generation DSCT (Flash 3rd), second group for prospective ECG-gated high-pitch scanning in second generation DSCT (Flash 2nd) and third group for prospective sequential scanning in third generation DSCT (Sequence 3rd). The SD value and SNR of aortic root and pulmonary artery of each child were recorded. The 5-point system is adopted with subjective scoring. Based on the result of operation, the diagnosis accuracy in 3 groups was analyzed. Results:The E values in Flash 3rd, Flash 2nd and Sequence 3rd group were 0.24 (0.19, 0.27), 0.11 (0.10, 0.14) and 0.44 (0.39, 0.48) mSv ( H=207.04, P<0.05), respectively. Subjective scores of group Flash 3rd and Sequence 3rd were significantly higher than that of group Flash 2nd [4 (4, 4) vs. 4(3, 4) vs. 3(3, 3), H=124.05, P<0.05] and no difference between these two groups. SD value of aortic root and pulmonary artery of group Flash 3rd and Sequence 3rd were significantly lower than that of group Flash 2nd( H= -40.27-33.38, P<0.05). SNR of aortic root and pulmonary artery of group Flash 3rd was significantly higher than that of group Flash 2nd and Sequence 3rd ( H=-0.90-51.42, P<0.05). Diagnosis accuracy of intracardiac malformation for group Flash 2nd was significantly lower than that of Flash 3rd and Sequence 3rd (77.7%, 90.9%, 88.9%, K=9.36, P<0.05), and there was no significant difference between the latter two groups. There was no difference in diagnosis accuracy of extracardiac malformation among 3 groups (88.6%, 94.8%, 92.2%, K=3.11, P=0.21). Conclusions:The prospective ECG-gated high-pitch scanning in third generation DSCT can take into account radiation dose and image quality, which has important clinical value in the diagnosis of CHD.

Objective:To explore the value of high frequency ultrasound scoring combined with serum levels of interleukin-6 (IL-6), C-reactive protein (CRP), and procalcitonin (PCT) in evaluating the prognosis of neonatal respiratory distress syndrome (NRDS) in children.Methods:A total of 106 children with NRDS who were treated at Shandong Provincial Maternal and Child Health Care Hospital Affiliated to Qingdao University from March 2021 to December 2022 were selected. According to the discharge outcome, NRDS patients were divided into a poor prognosis group ( n=11) and a good prognosis group ( n=95), and the clinical data differences between the two groups were compared. At the same time, NRDS patients were divided into mild to moderate group ( n=75) and severe group ( n=31) based on the severity of the disease. The differences in high-frequency ultrasound scores of the lungs and serum levels of IL-6, CRP, and PCT were analyzed in children with different disease severity levels of NRDS. Logistic multiple regression analysis was used to identify the influencing factors of prognosis; receiver operating characteristic (ROC) curve analysis of lung high-frequency ultrasound score, IL-6, and their combination predicted the prognostic value of NRDS in children. Results:The gestational age, birth weight, and high-frequency ultrasound scores of the lungs in the poor prognosis group were significantly lower than those in the good prognosis group (all P<0.05); The proportion of diabetes in pregnancy, the proportion of severe disease, the first use time of pulmonary surfactant (PS) and the level of IL-6 in the poor prognosis group were significantly higher than those in the good prognosis group (all P<0.05). The serum levels of IL-6, CRP, and PCT in severe children were significantly higher than those in mild to moderate children (all P<0.05); The high-frequency ultrasound score of the lungs in severe children was significantly lower than that in mild to moderate children ( P<0.05). Logistic regression analysis showed that gestational age, pulmonary high-frequency ultrasound score, gestational diabetes, disease severity, and IL-6 were the influencing factors for poor prognosis of children with NRDS (all P<0.05). The area under the ROC curve for predicting poor prognosis in children with NRDS using high-frequency ultrasound score, IL-6, and their combination were 0.745, 0.802, and 0.786, respectively. Conclusions:The severity of NRDS in children is related to the high-frequency ultrasound score of the lungs and serum levels of IL-6, CRP, and PCT. At the same time, the high-frequency ultrasound score of the lungs and IL-6 are related to the prognosis of NRDS children, and have certain application value in predicting the prognosis of children.

Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.

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 evaluate the feasibility and accuracy of virtual preoperative planning and 3D-printed templates for pre-contoured plates for the treatment of posterior wall fractures of the acetabulum.Methods A retrospective analysis of 29 patients with posterior acetabular wall fractures treated between August 2017 and March 2021 were divided into 2 groups based on whether to use preoperative virtual planning and 3D printed template.In 3D-printing group,there were 14 patients,includ-ing 10 males and 4 females;aged from 21 to 53 years old;CT-based virtual surgical planning was done using Mimics and 3-Matic software and 3D-printed templates for pre-contoured plates were adopted.In conventional group,there were 15 patients,including 10 males and 5 females;aged from 19 to 55 years old;conventional method of intra-operative contouring to adapt the plate to the fracture region was adopted.Blood loss,surgical time,radiographic quality of reduction,and hip function were compared between groups.Results The difference in operation time and intraoperative blood loss was significant(P＜0.05).Twenty-three patients were followed up from 12 to 30 months,and the fractures in both groups healed with a healing time of 3 to 6 months.At the last follow-up,the Merle d'Aubign-Postel score of the 3D printed group was lower than that of the conven-tional group(P＜0.05),with no significant differences in walking ability,hip mobility and total score(P＞0.05).In 3D printing group,6 cases were excellent,5 cases were good,3 cases were fair;in conventional group,5 cases were excellent,5 cases were good,4 cases were fair,1 case was worse;no significant difference between two groups(P＞0.05).Conclusion Virtual preopera-tive planning and 3D-printed templates for pre-contoured plates can reduce operative time and the blood loss of surgery,im-prove the quality of reduction.This method is efficient,accurate and reliable to treat acetabular posterior wall fractures.

Objective To develop a matrix metalloproteinase(MMP)-responsive hyaluronic acid(HA)-based controlled-release material for brain-derived neurotrophic factor(BDNF)to provide a novel therapeutic strategy for intervention and repair of traumatic brain injury(TBI).Methods HA was modified with amination,followed by condensation with Suflo-SMCC carboxyl group to form amide,and then linked with glutathione(GSH)to synthesize HA-GSH.The recombinant glutathione S-transferase(GST)-tissue inhibitor of metalloproteinase(TIMP)-BDNF(GST-TIMP-BDNF)expression plasmid was constructed using molecular cloning technique with double enzyme digestion by Bam H Ⅰ and Eco R Ⅰ.The recombinant GST-TIMP-BDNF protein was expressed in the Escherichia coli prokaryotic expression system,and purified by ion exchange chromatography,confirmed by Western blotting.MMP diluents were supplemented with PBS,MMP inhibitor marimastat,and varing concentrations(0.4,0.6,0.8 mg/ml)of GST-TIMP-BDNF or GST-BDNF.MMP-2 activity was analyzed using an MMP activity detection kit to evaluate the inhibitory effect of the recombinant protein on MMP.Primary rat neurons were extracted and cultured to establish an iron death model induced by RSL3.The effect of recombinant protein GST-TIMP-BDNF on neuronal injury was detected by immunofluorescence staining.Results MRI hydrogen spectrum identification confirmed the successful synthesis of HA-GSH.Western blotting results showed the successful expression of the recombinant protein GST-TIMP-BDNF containing the GST tag using the E.coli prokaryotic expression system.MMP activity detection results indicated that the recombinant protein GST-TIMP-BDNF had a superior inhibitory effect on MMP-2 activity compared to GST-BDNF(P<0.05).Immunofluorescence staining results showed a significant increase in fluorescence intensity in rat neurons treated with GST-TIMP-BDNF after RSL3 induction(P<0.05).Conclusion A MMP-responsive HA-based BDNF controlled-release material has been successfully developed,exhibiting a protective effect on neuron damage.

Neural tube defects are a common neurodevelopmental disease,which can be divided into open and closed types.The main symptoms are anencephaly,encephalocele and cranial spina bifida.The relationship between Wnt signaling and neurogenesis has been a popular area in recent years.The Wnt signaling pathway includes Wnt/β-catenin,planar polar cell pathway and Wnt/Ca2+pathway,which plays an important role in neural tube development.This article reviews the current state of research on the Wnt signaling pathway and elucidates the role it plays in the process of neural tube closure,providing insights for the development of drugs related to the prevention and treatment of neural tube defects.