BACKGROUND:How to effectively promote bone regeneration and bone reconstruction after bone injury has always been a key issue in clinical bone repair research.The use of biological and degradable materials loaded with bioactive factors to treat bone defects has excellent application prospects in bone repair. OBJECTIVE:To investigate the effect of polylactic acid-glycolic acid copolymer(PLGA)composite scaffold modified by lysine-grafted graphene oxide nanoparticles(LGA-g-GO)on osteogenic differentiation and new bone formation. METHODS:PLGA was dissolved in dichloromethane and PLGA scaffold was prepared by solvent evaporation method.PLGA/GO composite scaffolds were prepared by dispersing graphene oxide uniformly in PLGA solution.LGA-g-GO nanoparticles were prepared by chemical grafting method,and the PLGA/LGA-g-GO composite scaffolds were constructed by blending LGA-g-GO nanoparticles at different mass ratios(1%,2%,and 3%)with PLGA.The micromorphology,hydrophilicity,and protein adsorption capacity of scaffolds of five groups were characterized.MC3T3 cells were inoculated on the surface of scaffolds of five groups to detect cell proliferation and osteogenic differentiation. RESULTS AND CONCLUSION:(1)The surface of PLGA scaffolds was smooth and flat under scanning electron microscope,while the surface of the other four scaffolds was rough.The surface roughness of the composite scaffolds increased with the increase of the addition of LGA-g-GO nanoparticles.The water contact angle of PLGA/LGA-g-GO(3%)composite scaffolds was lower than that of the other four groups(P<0.05).The protein adsorption capacity of PLGA/LGA-g-GO(1%,2%,and 3%)composite scaffolds was stronger than PLGA and PLGA/GO scaffolds(P<0.05).(2)CCK-8 assay showed that PLGA/LGA-g-GO(2%,3%)composite scaffold could promote the proliferation of MC3T3 cells.Alkaline phosphatase staining and alizarin red staining showed that the cell alkaline phosphatase activity in PLGA/LGA-g-GO(2%,3%)group was higher than that in the other three groups(P<0.05).The calcium deposition in the PLGA/GO and PLGA/LGA-g-GO(1%,2%,and 3%)groups was higher than that in the PLGA group(P<0.05).(3)In summary,PLGA/LGA-g-GO composite scaffold can promote the proliferation and osteogenic differentiation of osteoblasts,and is conducive to bone regeneration and bone reconstruction after bone injury.

Objective: To investigate the regional differences in the incidence of urothelial carcinoma among kidney transplant recipients between northern and southern China，so as to provide reference for early diagnosis of this disease. Methods: A comprehensive search was conducted across multiple databases，including CNKI，Wanfang，CBM，and PubMed，using the keywords “kidney transplantation” and “tumor” to collect clinical data from qualified kidney transplant centers.The latest and most complete literature data published by 17 transplant centers in northern China and 14 in southern China were included.Statistical analyses were performed to compare the incidence of post-transplant urothelial carcinoma and non-urothelial malignancies. Results: A total of 37 475 kidney transplant recipients were included，among whom 837 (2.23%) developed post-transplant malignancies，including urothelial carcinoma (366/837，43.73%)，non-urothelial carcinoma (444/837，53.05%)，and malignancies with unspecified pathology (27/837，3.23%).The incidence of malignancies was significantly higher in northern China than in southern China [(2.82±1.39)% vs. (1.67±0.83)%，P=0.011]，with a particularly pronounced difference in the incidence of urothelial carcinoma [(1.68±1.12)% vs. (0.32±0.32)%，P<0.001].No significant difference was observed in the incidence of non-urothelial carcinoma between the two regions [(1.11±0.56)% vs. (1.35±0.65)%，P=0.279].Additionally，female transplant recipients exhibited a higher incidence of malignancies than males in both regions (southern China：2.38% vs. 1.80%; northern China：8.93% vs. 2.52%). Conclusion: The incidence of urothelial carcinoma following kidney transplantation is significantly higher in northern China than in southern China，underscoring the importance of implementing regular tumor screening for kidney transplant recipients，particularly for female patients in northern China，to facilitate early diagnosis and timely intervention.

With the optimization of surgical technologies and postoperative management regimens, the number of lung transplantation has been significantly increased, which has become an important treatment for patients with end-stage lung disease. However, due to the impact of comprehensive factors, such as bronchial ischemia and immunosuppression, the incidence of airway stenosis after lung transplantation is relatively high, which severely affects postoperative survival and quality of life of lung transplant recipients. In recent years, with the improvement of perioperative management, organ preservation and surgical technologies, the incidence of airway stenosis after lung transplantation has been declined, but it remains at a high level. Early diagnosis and timely intervention play a significant role in enhancing clinical prognosis of patients with airway stenosis. In this article, the general conditions, diagnosis, treatment and prevention of airway stenosis after lung transplantation were reviewed, aiming to provide reference for comprehensive management of airway stenosis after lung transplantation and improving clinical prognosis of lung transplant recipients.

Digital polymerase chain reaction(dPCR)is a PCR technology that realizes accurate quantification of single-copy nucleic acid molecules by dividing the reaction system into tens of thousands of independent PCR reaction units for single-molecule-level amplification and integrating Poisson distribution.Due to its single-copy sensitivity and accurate quantification without the need of standard curves,dPCR has been widely used in disease diagnosis.By introducing technologies such as stepped emulsification and three-dimensional imaging,dPCR has been greatly improved in terms of accuracy,multiplexability and turnaround time,significantly enhancing its performance in clinical disease diagnosis.Based on this,this paper traced the technological development history of dPCR,gave an overview of its application in detection of tumors,infections and other diseases,and further discussed the challenges and opportunities of the development of dPCR,with the aim of providing a reference for the development and utilization of dPCR in the future,and promoting the high-quality development of molecular technology in clinical testing.

AIM To prepare the soluble microneedles of Aconitum brachypodum Diels alkaloids.METHODS Centrifugal molding method was adopted in the preparation of soluble microneedles.With chondroitin sulfate consumption,PVP K120 consumption and 40%ethanol consumption as influencing factors,piercing rate as an evaluation index,the formulation was optimized by Box-Behnken response surface method,after which the morphology,piercing performance,drug content and in vitro transdermal performance were investigated.RESULTS The optimal formulation was determined to be 123 mg for chondroitin sulfate consumption,298 mg for PVP K120 consumption,and 2.4 mL for 40%ethanol consumption,the piercing rate was 98.3%.The soluble microneedles were yellow and square patch with conoid needle,which could pierce aluminum foil and rat skin,along with the drug content of(0.94±0.025)mg.The soluble microneedle group demonstrated the accumulative permeability rate of 91.4%within 24 h,which was higher than that in the gel ointment group,and the permeability accorded with Higuchi equation.CONCLUSION The soluble microneedles of A.brachypodum alkaloids exhibit good mechanical strength,which can achieve effective transdermal delivery of drugs.

The paper is to establish an UPLC-MS/MS method for the simultaneous determination of 19 components in Microctis Folium from different production areas. The 50% methanol was used as extraction solvent. The Agilent ZORBAX SB C18 (150 mm × 2.1 mm, 1.8 μm) column was used; mobile phase was acetonitrile - 0.1% acetic acid with gradient elution, flow rate was 0.3 mL·min^-1, colume temperature was 30 ℃, and the injection volume was 2 μL; electrospray ionizaton source was used and detected in negative ion mode. The results showed that the established UPLC-MS/MS method could well separate the 19 components, and the methodological investigation results of 19 components were good. By means of orthogonal partial least squares discriminant analysis (OPLS-DA), 28 batches of Microctis Folium samples from different production areas can be divided into three categories, Guangdong, Guangxi and Hainan are each classified into one category, and 10 signature compounds which affecting the quality differences of different production areas were screened out. The established method is accurate, reliable, sensitive and reproducible. It can provide a basis for the establishment of the quality standard of Microctis Folium, as well as for safety and quality research.

Objective To investigate the dosimetric effects of different calculation grid size(CGS)in helical tomotherapy(HT)planning system on stereotactic body radiation therapy(SBRT)for non-small cell lung cancer(NSCLC).Methods Nine NSCLC patients receiving radiation therapy for the first time at some hospital from March 2019 to December 2022 were selected as the subjects.SBRT planning was carried out through the HT system with three different CGS plans(Fine,Normal,and Coarse)and the same pitch,modulation factor(MF)and optimization conditions,and the target area indexes of the three CGS plans were compared including conformity index(CI),homogeneity index(HI),dosimetric parameters of the organ at risk(OAR),point dose verification pass rate,treatment time,number of monitor units and Sinograms.SPSS 22.0 was used for statistical analysis.Results For target area HI,there weres significant differences between CGS Fine plan and Coarse plan and between CGS Normal plan and Coarse plan(P＜0.05),while no statistical differences were found between CGS Fine plan and Normal plan(P＞0.05).For target area CI,there were significant differences between CGS Fine plan and Coarse plan(P＜0.05),while no statistical differences were found between CGS Fine plan and Normal plan and between CGS Normal plan and Coarse plan(P＞0.05).For OAR dosimetric parameters,CGS Fine plan and Coarse plan had significant differences in heart Dmax and Dmean,esophageal Dmax and Dmean,V5,V20,V30 and Dmean of the whole lung and affected lung,V5 and Dmax of the affected lung and heart V10 and V30(P＜0.05),CGS Normal plan and Coarse plan had obvious differences in esophageal Dmax(P＜0.05),and the remained dosimetric parameters were not statistically significant(P＞0.05).Fine,Normal and Coarse plans had the point dose verifica-tion pass rates being 0.96％,1.50％and 1.77％,respectively.In terms of treatment time and number of monitor units,there were significant differences between Fine plan and Coarse plan(P＜0.05)while no statistical differences were found between Fine and Normal plans and between Normal and Coarse plans(P＞0.05).Sinograms analyses showed Fine plan had evenly distributed segment color gradient,Coarse plan had areas of very dark and very light color gradients and Normal plan was somewhere in between.Conclusion Low CGS has to be used as much as possible to obtain accurate dose distribution during SBRT planning for NSCLC patients,which contributes to the execution of the radiation therapy plan and the prevention of ad-verse effects.[Chinese Medical Equipment Journal,2024,45(2):52-57]

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 antifungal resistance of clinical isolates of Candida spp.in the East China region.Methods MALDI-TOF MS or molecular methods were used to re-identify the strains collected from January 2018 to December 2022.Antifungal susceptibility testing was performed using the broth microdilution method.The susceptibility test results were interpreted according to the breakpoints of 2022 Clinical and Laboratory Standards Institute(CLSI)documents M27 M44s-Ed3 and M57s-Ed4.Results A total of 3 026 strains of Candida were collected,65.33％of which were isolated from sterile body sites,mainly from blood(38.86％)and pleural effusion/ascites(10.21％).The predominant species of Candida were Candida albicans(44.51％),followed by Candida parapsilosis complex(19.46％),Candida tropicalis(13.98％),Candida glabrata(10.34％),and other Candida species(0.79％).Candida albicans showed overall high susceptibility rates to the 10 antifungal drugs tested(the lowest rate being 93.62％).Only 2.97％of the strains showed dose-dependent susceptibility(SDD)to fluconazole.Candida parapsilosis complex had a SDD rate of 2.61％and a resistance rate of 9.42％to fluconazole,and susceptibility rates above 90％to other drugs.Candida glabrata had a SDD rate of 92.01％and a resistance rate of 7.99％to fluconazole,resistance rates of 32.27％and 48.24％to posaconazole and voriconazole non-wild-type strains(NWT),respectively,and susceptibility rates above 90％to other drugs.Candida tropicalis had resistance rates of 29.55％and 26.24％to fluconazole and voriconazole,respectively,resistance rates of 76.60％and 21.99％to posaconazole and echinocandins non-wild-type strains(NWT),and a resistance rate of 2.36％to echinocandins.Conclusions The prevalence and species distribution of Candida spp.in the East China region are consistent with previous domestic and international reports.Candida glabrata exhibits certain degree of resistance to fluconazole,while Candida tropicalis demonstrates higher resistance to triazole drugs.Additionally,echinocandins resistance has emerged in Candida albicans,Candida glabrata,Candida tropicalis,and Candida parapsilosis.

Aim To explore whether platelet-derived growth factor C(PDGFC)derived from cancer-associat-ed fibroblasts(CAFs)can promote resistance of breast cancer cells to doxorubicin(DOX)and the underlying mechanisms.Methods CAFs and normal fibroblasts(NFs)were extracted from freshly resected breast cancer tissue and adjacent normal breast tissue respec-tively.Conditioned medium(CM)from CAFs and NFs was collected and co-cultured with breast cancer cells.Cell proliferation and toxicity were assessed using a Cell Counting Kit-8(CCK-8).The expression of PDG-FC in CAFs,NFs and corresponding CM was detected by Western blot and ELISA respectively.The influence of CAFs-CM on intracellular doxorubicin content in breast cancer cells was observed by fluorescence mi-croscopy.The impact of CAFs-CM on apoptosis-related proteins BAX and BCL2 was predicted and valifated u-sing the Starbase database and Western blot.The changes in ROS levels,mitochondrial membrane po-tential,and mitochondrial membrane proteins TOM20 and COX Ⅳ in breast cancer cells were measured using DCFH-DA fluorescence staining,JC-1 assay,and Western blot.Results CAFs-CM decreased the intra-cellular doxorubicin content and inhibited the sensitivi-ty of breast cancer cells to doxorubicin.Additionally,the expression of apoptosis protein BAX decreased while the anti-apoptotic protein BCL2 increased in breast cancer cells cultured with CAFs-CM.Further-more,CAFs-CM led to decreased ROS levels and in-creased mitochondrial membrane potential in breast cancer cells accompanied with elevated expression of mitochondrial membrane proteins TOM20 and COX Ⅳ.Further study found that PDGEF was highly expressed in CAFs and CAFs-CM,recombinant human PDGFC produced resistance of breast cancer cells to DOX simi-lar to CAFs-CM,and the specific inhibitors of PDGFRα significantly inhibited CAFs-CM.Further mechanistic studies revealed that PDGFC in CAFs-CM induced chemoresistance by activating PI3K-mTOR signaling pathway.Conclusion PDGFC secreted by CAFs promotes doxorubicin resistance in breast cancer cells through PI3K-mTOR signaling pathway,which provides a new perspective for the development of anti-cancer drugs targeting CAFs.