BACKGROUND:Autologous bone,allogeneic bone or artificial bone has been used to promote bone defect repair in the clinic,but the rate of non-healing is still high.The key is to ignore the importance of periosteum in the bone healing process.In the early stage of the project,the project team constructed an electrospinning membrane loaded with vascular endothelial growth factor to highly simulate the intramembranous osteogenesis of natural periosteum at the bone defect site,which promoted bone regeneration to a certain extent.However,the injured area often faces the dilemma of severe inflammatory response mediated by macrophages and lack of seed cells,resulting in the risk of inactivation or diffusion of delivered biological factors.Therefore,it is necessary to further optimize and coordinate the immune regulation and angiogenesis functions of biomimetic periosteum to promote bone repair.OBJECTIVE:To investigate the physicochemical properties of stem cell-engineered bionic periosteum and its role in regulating the inflammatory microenvironment to promote bone repair.METHODS:By combining L-polylactic acid-based microsol electrospinning,type Ⅰ collagen self-assembly and gel stem cell transplantation technology,a bionic periosteum(M@C-B)was constructed,in which the core layer loaded with vascular endothelial growth factor and the shell layer delivered bone marrow mesenchymal stem cells to regulate the immune microenvironment of bone defects.The physicochemical properties of the periosteum were characterized by scanning electron microscopy,transmission electron microscopy,and Fourier transform infrared spectroscopy.A co-culture system was established between the bionic periosteum and macrophages,bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to explore immune regulation and in vitro osteogenic and angiogenic abilities.Finally,the osteogenic properties of the stem cell engineered bionic periosteum were further verified in a rat femoral condyle defect model.RESULTS AND CONCLUSION:(1)Transmission electron microscopy results showed that the micro-sol electrospinning(MS)formed a distinct core-shell structure.Scanning electron microscopy indicated that after the assembly of the collagen-l artificial periosteum(M@C)on the surface of the vascular endothelial growth factor-loaded micro-sol,a distinct"spider web-like"fibrous structure was deposited.Infrared spectroscopy further confirmed the successful self-assembly of collagen-l.Release experiments demonstrated that the M@C group mitigated the burst release phenomenon compared to the MS group,maintaining internal vascular endothelial growth factor activity and sustained release.(2)Live/dead cell staining and CCK-8 assay showed that bone marrow mesenchymal stem cells proliferated well and survived on three types of artificial periosteum:MS,purely aligned poly(L-lactic acid)(PLLA)surface self-assembled collagen-l artificial periosteum(PLLA@C),and vascular endothelial growth factor-loaded micro-sol fiber surface self-assembled collagen-l-bone marrow mesenchymal stem cells artificial periosteum(M@C-B).Among them,the M@C-B group had the highest number of live cells and the fastest proliferation rate.(3)Alkaline phosphatase staining,alizarin red staining,and osteopontin immunofluorescence staining showed that the PLLA@C and M@C-B groups significantly promoted osteogenic differentiation of bone marrow mesenchymal stem cells.Angiogenesis experiments demonstrated that the vascular endothelial growth factor-loaded groups(MS and M@C-B)had longer blood vessel lengths and more reticular vascular-like structures with more cross-linked nodes,with the M@C-B group being the most prominent.(4)Immunofluorescence and flow cytometry showed that artificial periosteum in the M@C-B group significantly inhibited the pro-inflammatory macrophage phenotype and promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype.(5)In vivo studies further confirmed that the M@C-B group showed superior bone mineral density,trabecular thickness,relative bone volume,and trabecular spacing compared to other groups.(6)These results indicate that bone marrow mesenchymal stem cell-engineered artificial periosteum,through the rapid regulation of the bone defect immune microenvironment by the collagen-l-bone marrow mesenchymal stem cells outer phase and the sustained release of vascular endothelial growth factor by the micro-sol electrospinning core-shell structure of the inner phase,synergistically promotes bone healing.

BACKGROUND:Autologous bone,allogeneic bone or artificial bone has been used to promote bone defect repair in the clinic,but the rate of non-healing is still high.The key is to ignore the importance of periosteum in the bone healing process.In the early stage of the project,the project team constructed an electrospinning membrane loaded with vascular endothelial growth factor to highly simulate the intramembranous osteogenesis of natural periosteum at the bone defect site,which promoted bone regeneration to a certain extent.However,the injured area often faces the dilemma of severe inflammatory response mediated by macrophages and lack of seed cells,resulting in the risk of inactivation or diffusion of delivered biological factors.Therefore,it is necessary to further optimize and coordinate the immune regulation and angiogenesis functions of biomimetic periosteum to promote bone repair.OBJECTIVE:To investigate the physicochemical properties of stem cell-engineered bionic periosteum and its role in regulating the inflammatory microenvironment to promote bone repair.METHODS:By combining L-polylactic acid-based microsol electrospinning,type Ⅰ collagen self-assembly and gel stem cell transplantation technology,a bionic periosteum(M@C-B)was constructed,in which the core layer loaded with vascular endothelial growth factor and the shell layer delivered bone marrow mesenchymal stem cells to regulate the immune microenvironment of bone defects.The physicochemical properties of the periosteum were characterized by scanning electron microscopy,transmission electron microscopy,and Fourier transform infrared spectroscopy.A co-culture system was established between the bionic periosteum and macrophages,bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to explore immune regulation and in vitro osteogenic and angiogenic abilities.Finally,the osteogenic properties of the stem cell engineered bionic periosteum were further verified in a rat femoral condyle defect model.RESULTS AND CONCLUSION:(1)Transmission electron microscopy results showed that the micro-sol electrospinning(MS)formed a distinct core-shell structure.Scanning electron microscopy indicated that after the assembly of the collagen-l artificial periosteum(M@C)on the surface of the vascular endothelial growth factor-loaded micro-sol,a distinct"spider web-like"fibrous structure was deposited.Infrared spectroscopy further confirmed the successful self-assembly of collagen-l.Release experiments demonstrated that the M@C group mitigated the burst release phenomenon compared to the MS group,maintaining internal vascular endothelial growth factor activity and sustained release.(2)Live/dead cell staining and CCK-8 assay showed that bone marrow mesenchymal stem cells proliferated well and survived on three types of artificial periosteum:MS,purely aligned poly(L-lactic acid)(PLLA)surface self-assembled collagen-l artificial periosteum(PLLA@C),and vascular endothelial growth factor-loaded micro-sol fiber surface self-assembled collagen-l-bone marrow mesenchymal stem cells artificial periosteum(M@C-B).Among them,the M@C-B group had the highest number of live cells and the fastest proliferation rate.(3)Alkaline phosphatase staining,alizarin red staining,and osteopontin immunofluorescence staining showed that the PLLA@C and M@C-B groups significantly promoted osteogenic differentiation of bone marrow mesenchymal stem cells.Angiogenesis experiments demonstrated that the vascular endothelial growth factor-loaded groups(MS and M@C-B)had longer blood vessel lengths and more reticular vascular-like structures with more cross-linked nodes,with the M@C-B group being the most prominent.(4)Immunofluorescence and flow cytometry showed that artificial periosteum in the M@C-B group significantly inhibited the pro-inflammatory macrophage phenotype and promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype.(5)In vivo studies further confirmed that the M@C-B group showed superior bone mineral density,trabecular thickness,relative bone volume,and trabecular spacing compared to other groups.(6)These results indicate that bone marrow mesenchymal stem cell-engineered artificial periosteum,through the rapid regulation of the bone defect immune microenvironment by the collagen-l-bone marrow mesenchymal stem cells outer phase and the sustained release of vascular endothelial growth factor by the micro-sol electrospinning core-shell structure of the inner phase,synergistically promotes bone healing.

AIM To optimize the extraction process for total polyphenols from Conioselinum vaginatu(Spreng.)Thell.,make component analysis,and evaluate their anti-oxidant,hypoglycemic activities.METHODS The effects of ultrasound,enzymatic hydrolysis,acid hydrolysis,alcohol extraction and hydrolysis processes on the extraction quantity of total polyphenols were investigated,respectively.With extraction temperature,extraction time,ethanol concetration and liquid-solid ratio as influencing factors,extraction quantity of total polyphenols as an evaluation index,the extraction process was optimized by response surface method.HPLC was adopted in the identification of polyphenolic composition and determination of their contents.Subsequently,total polyphenols' scavenging capacities on DPPH,ABTS,OH free radicals,total reducing power and inhibitory capacity on α-glucosidase were determined.RESULTS The highest extraction quantity of total polyphenols was observable when extraction process was employed.The optimal conditions were determined to be 62 ℃ for extraction temperature,54 min for extraction time,69％for ethanol concentration,and 50∶1 for liquid-solid ratio,the extraction quantity of total polyphenols was(9.51±0.2)mg GAE/g.Seven constituents existed in C.vaginatu,among which ferulic acid demonstrated the highest content,followed by that of myricetin,while D-tryptophan content was the lowest.At the concentration of 7.61 mg/L,total polyphenols displayed the scavenging rates on DPPH,ABTS,OH free radicals of 80.70％,85.97％,28.60％,total reducing power of 0.22,and inhibition rate on α-glucosidase of 77.23％,respectively.CONCLUSION This stable and reliable method can be used for the extraction of total polyphenols from C.vaginatum with strong anti-oxidant,hypoglycemic activities.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective:To explore the efficacy of non-invasive prenatal testing (NIPT) of fetal free DNA in maternal peripheral blood in fetuses with increased nuchal translucency (NT).Methods:A retrospective analysis was conducted on 1 184 singleton pregnant women that underwent chromosomal microarray analysis (CMA) at Nanjing Drum Tower Hospital, Nanjing University Medical School from June 2014 to December 2022 due to fetal increased NT (≥3.0 mm). These subjects were categorized based on whether the increased NT was accompanied by other high-risk factors into isolated increased NT without advanced maternal age (further subdivided into 3.0 mm≤NT<3.5 mm, 3.5 mm≤NT<4.0 mm, and NT≥4.0 mm subgroups), isolated increased NT with advanced maternal age, increased NT with nasal bone abnormalities, increased NT with other soft markers, and increased NT with structural abnormalities groups. Assuming the sensitivity and specificity of NIPT and expanded NIPT at this center were both 100%, genomic abnormalities outside the detection range of NIPT or expanded NIPT were termed as residual risk of NIPT or expanded NIPT. Chi-square test and Bonferroni correction were used to compare the residual risks of NIPT and expanded NIPT among the three subgroups of isolated increased NT without advanced maternal age group. Results:(1) In the group of isolated increased NT without advanced maternal age: For the 3.0 mm≤NT<3.5 mm subgroup (329 cases), 19 abnormalities were detected by CMA [12 cases of chromosome aneuploidy, seven cases of pathogenic copy number variation (pCNV)], with residual risks of NIPT and expanded NIPT both at 2.1% (7/329). For the 3.5 mm≤NT<4.0 mm subgroup (173 cases), 29 abnormalities were detected by CMA (17 cases of chromosome aneuploidy, nine cases of pCNV, three cases of chromosome unbalanced translocation), with residual risks of NIPT at 8.1% (14/173) and expanded NIPT at 7.5% (13/173). For the NT≥4.0 mm subgroup (270 cases), CMA detected abnormalities in 70 cases (50 cases of chromosome aneuploidy, 16 cases of pCNV, three cases of unbalanced translocations, and one case of sex chromosome abnormality combined with pCNV). The residual risk of NIPT was 12.2% (33/270), and the residual risk of expanded NIPT was 7.0% (19/270). The residual risks of NIPT and expanded NIPT in the 3.0 mm≤NT<3.5 mm subgroup were lower than those in the 3.5 mm≤NT<4.0 mm and NT≥4.0 mm subgroups (Bonferroni correction, all P<0.017). (2) In the group of 92 cases with isolated increased NT and advanced maternal age, CMA detected abnormalities in 36 cases (29 cases of chromosome aneuploidy, five cases of pCNV, one case of trisomy 21 combined with sex chromosome abnormality, and one case of trisomy 18 combined with sex chromosome abnormality). The residual risk of NIPT was 7.6% (7/92), and that of expanded NIPT was 5.4% (5/92). (3) In the group of 49 cases with increased NT combined with nasal bone abnormalities, CMA detected abnormalities in 24 cases (23 cases of chromosome aneuploidy and one case of pCNV). The residual risks of NIPT and expanded NIPT were both 2.0% (1/49). (4) In the group of 26 cases with increased NT combined with other soft markers, CMA detected abnormalities in nine cases (six cases of chromosome aneuploidy, one case of pCNV, and two cases of chromosome unbalanced translocations). The residual risks of NIPT and expanded NIPT were both 11.5% (3/26). (5) In the group of 245 cases with increased NT combined with structural abnormalities, CMA detected abnormalities in 121 cases (107 cases of chromosome aneuploidy, seven cases of pCNV, four cases of chromosome unbalanced translocations, one case of trisomy 21 combined with trisomy 20, and two cases of trisomy 18 combined with sex chromosome abnormalities). The residual risk of NIPT was 16.7% (41/245), and that of expanded NIPT was 4.1% (10/245). Conclusions:For isolated NT≥3.5 mm or NT≥3.0 mm combined with other high-risk factors, chorionic villus sampling in early pregnancy can be recommended, advancing the timing of prenatal diagnosis from the second trimester to the first trimester. For fetuses with isolated 3.0 mm≤NT<3.5 mm, the 2.1% residual risk of chromosomal abnormalities should be fully informed during counseling, even if the risk of NIPT is low.

Objective:To explore the construction method of a resistant multiple myeloma(MM)patient-derived xenotransplantation(PDX)model.Methods:1.0 × 107 MM patient-derived mononuclear cells(MNCs),2.0 × 106 MM.1S cells and 2.0 × 106 NCI-H929 cells were respectively subcutaneously inoculated into NOD.CB17-Prkdcscid Il2rgtml/Bcgen(B-NDG)mice with a volume of 100 p1 per mouse to establish mouse model.The morphologic,phenotypic,proliferative and genetic characteristics of PDX tumor were studied by hematoxylin-eosin staining,immunohistochemical staining(IHC),cell cycle analysis,flow cytometry and fluorescence in situ hybridization(FISH).The sensitivity of PDX tumor to bortezomib and anlotinib monotherapy or in combination was investigated through cell proliferation,apoptosis and in vitro and in vivo experiments.The effects of anlotinib therapy on tumor blood vessel and cell apoptosis were analyzed by IHC,TUNEL staining and confocal fluorescence microscope.Results:MM PDX model was successfully established by subcutaneously inoculating primary MNCs.The morphologic features of tumor cells from MM PDX model were similar to those of mature plasma cells.MM PDX tumor cells positively expressed CD138 and CD38,which presented 1q21 amplification,deletion of Rb1 and IgH rearrangement,and had a lower proliferative activity than MM cell lines.In vitro,PDX,MM.1S and NCI-H929 cells were treated by bortezomib and anlotinib for 24 hours,respectively.Cell viability assay showed that the IC50 value of bortezomib were 5 716.486,1.025 and 2.775 nmol/L,and IC50 value of anlotinib were 5 5107.337,0.706 and 5.13 μmol/L,respectively.Anlotinib treatment increased the apoptosis of MM.1S cells(P＜0.01),but did not affect PDX tumor cells(P＞0.05).In vivo,there was no significant difference in PDX tumor growth between bortezomib monotherapy group and control group(P＞0.05),while both anlotinib monotherapy and anlotinib combined with bortezomib effectively inhibited PDX tumor growth(both P＜0.05).The vascular perfusion and vascular density of PDX tumor were decreased in anlotinib treatment group(both P＜0.01).The apoptotic cells in anlotinib treatment group were increased compared with those in control group(P＜0.05).Conclusion:Bortezomib-resistant MM PDX model can be successfully established by subcutaneous inoculation of MNCs from MM patients in B-NDG mice.This PDX model,which retains the basic biological characteristics of MM cells,can be used to study the novel therapies.

Objective:To investigate the efficacy and safety of bendamustine combined with anti-CD20 monoclonal antibody in the first-line treatment of older patients with indolent B-cell non-Hodgkin lymphoma (B-iNHL) .Methods:The clinical data of 159 patients with B-iNHL enrolled in 16 hospitals from Jiangsu Cooperative Lymphoma Group from December 1, 2019, to April 20, 2024, were analyzed for regimen efficacy and safety. Bendamustine plus rituximab (BR) and bendamustine plus obinutuzumab (BG) were administered to 139 (87.4% ) and 20 (12.6% ) patients, respectively.Results:Among the 159 patients, 101 (63.5% ) were male and 58 (36.5% ) were female, with a median age of 69 years (range: 60–84). Efficacy could be assessed in 138 (86.8% ) patients. The efficacy assessment demonstrated that the overall response rate was 92.0% with complete and partial remissions in 75 (54.3% ) and 52 (37.7% ) cases, respectively. With a median follow-up of 24 months (range: 4–64), the progression-free survival rate was (87.5 ± 3.0) % and the overall survival rate was (83.2 ± 3.3) %. Of the 27 patients who died, 6 (22.2% ) died due to disease progression. The mean applied dose of bendamustine per cycle was 73.0 (50.8–89.7) mg/m 2 per day, administered on days 1 and 2. Adverse events of grade 3 or higher were reported in 53 (33.3% ) patients, with infection (30 cases,18.9% ) and neutropenia (24 cases, 15.1% ) demonstrating the highest incidence. Conclusion:Bendamustine combined with anti-CD20 monoclonal antibody demonstrated good efficacy and is well-tolerated in the first-line treatment of elderly patients with B-iNHL.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.