BACKGROUND:As tissue engineering brings new hope to the worldwide problem of articular cartilage repair,the construction of light-curing 3D printed hydrogel scaffolds with biomimetic composition is of great significance for cartilage tissue engineering. OBJECTIVE:To construct a biomimetic methacryloylated hyaluronic acid/acellular Wharton's jelly composite hydrogel scaffold by digital light processing 3D printing technology,and to evaluate its biocompatibility. METHODS:Wharton's jelly was isolated and extracted from human umbilical cord,then decellulated,freeze-dried,ground into powder,and dissolved in PBS to prepare 50 g/L acellular Wharton's jelly solution.Methylallylated hyaluronic acid was prepared,lyophilized and dissolved in PBS to prepare 50 g/L methylallylated hyaluronic acid solution.Acellular Wharton's jelly solution was mixed with methacrylyacylated hyaluronic acid solution at a volume ratio of 1:1,and was used as bio-ink after adding photoinitiator.Methylacrylylated hyaluronic acid hydrogel scaffolds(labeled as HAMA hydrogel scaffolds)and methylacrylylated hyaluronic acid/acellular Wharton's jelly gel scaffolds(labeled as HAMA/WJ hydrogel scaffolds)were prepared by digital light processing 3D printing technology,and the microstructure,swelling performance,biocompatibility,and cartilage differentiation performance of the scaffolds were characterized. RESULTS AND CONCLUSION:(1)Under scanning electron microscope,the two groups of scaffolds showed a three-dimensional network structure,and the fiber connection of HAMA/WJ hydrogel scaffold was more uniform.Both groups achieved swelling equilibrium within 10 hours,and the equilibrium swelling ratio of HAMA/WJ hydrogel scaffold was lower than that of HAMA hydrogel scaffold(P＜0.05).(2)CCK-8 assay showed that HAMA/WJ hydrogel scaffold could promote the proliferation of bone marrow mesenchymal stem cells compared with HAMA hydrogel scaffold.Dead/live staining showed that bone marrow mesenchymal stem cells grew well on the two groups of scaffolds,and the cells on the HAMA/WJ hydrogel scaffolds were evenly distributed and more cells were found.Phalloidine staining showed better adhesion and spread of bone marrow mesenchymal stem cells in HAMA/WJ hydrogel scaffold than in HAMA.(3)Bone marrow mesenchymal stem cells were inoculated into the two groups for chondrogenic induction culture.The results of qRT-PCR showed that the mRNA expressions of agglutinoglycan,SOX9 and type Ⅱ collagen in the HAMA/WJ hydrogel scaffold group were higher than those in the HAMA hydrogel scaffold group(P＜0.05,P＜0.01).(4)These findings indicate that the digital light processing 3D bioprinting HAMA/WJ hydrogel scaffold can promote the proliferation,adhesion,and chondrogenic differentiation of bone marrow mesenchymal stem cells.

Temporomandibular joint (TMJ) diseases are common clinical conditions. The number of patients with TMJ diseases is large, and the etiology, epidemiology, disease spectrum, and treatment of the disease remain controversial and unknown. To understand and master the current situation of the occurrence, development and prevention of TMJ diseases, as well as to identify the patterns in etiology, incidence, drug sensitivity, and prognosis is crucial for alleviating patients′suffering.This will facilitate in-depth medical research, effective disease prevention measures, and the formulation of corresponding health policies. Cohort construction and research has an irreplaceable role in precise disease prevention and significant improvement in diagnosis and treatment levels. Large-scale cohort studies are needed to explore the relationship between potential risk factors and outcomes of TMJ diseases, and to observe disease prognoses through long-term follw-ups. The consensus aims to establish a standard conceptual frame work for a cohort study on patients with TMJ disease while providing ideas for cohort data standards to this condition. TMJ disease cohort data consists of both common data standards applicable to all specific disease cohorts as well as disease-specific data standards. Common data were available for each specific disease cohort. By integrating different cohort research resources, standard problems or study variables can be unified. Long-term follow-up can be performed using consistent definitions and criteria across different projects for better core data collection. It is hoped that this consensus will be facilitate the development cohort studies of TMJ diseases.

Objective To investigate the disease spectrum and pathogenic genes of inherited metabolic disorder(IMD)among neonates in Gansu Province of China.Methods A retrospective analysis was conducted on the tandem mass spectrometry data of 286 682 neonates who received IMD screening in Gansu Provincial Maternal and Child Health Hospital from January 2018 to December 2021.A genetic analysis was conducted on the neonates with positive results in tandem mass spectrometry during primary screening and reexamination.Results A total of 23 types of IMD caused by 28 pathogenic genes were found in the 286 682 neonates,and the overall prevalence rate of IMD was 0.63‰(1/1 593),among which phenylketonuria showed the highest prevalence rate of 0.32‰(1/3 083),followed by methylmalonic acidemia(0.11‰,1/8 959)and tetrahydrobiopterin deficiency(0.06‰,1/15 927).In this study,166 variants were identified in the 28 pathogenic genes,with 13 novel variants found in 9 genes.According to American College of Medical Genetics and Genomics guidelines,5 novel variants were classified as pathogenic variants,7 were classified as likely pathogenic variants,and 1 was classified as the variant of uncertain significance.Conclusions This study enriches the database of pathogenic gene variants for IMD and provides basic data for establishing an accurate screening and diagnosis system for IMD in this region.

Artificial vascular graft(AVG)fistula is widely used for hemodialysis treatment in patients with renal failure.However,it has poor elasticity and compliance,leading to stenosis and thrombosis.The ideal artificial blood vessel for dialysis should replicate the structure and components of a real artery,which is primarily maintained by collagen in the extracellular matrix(ECM)of arterial cells.Studies have revealed that in hepatitis B virus(HBV)-induced liver fibrosis,hepatic stellate cells(HSCs)become hyperactive and produce excessive ECM fibers.Furthermore,mechanical stimulation can encourage ECM secretion and remodeling of a fiber structure.Based on the above factors,we transfected HSCs with the hepatitis B viral X(HBX)gene for simulating the process of HBV infection.Subsequently,these HBX-HSCs were implanted into a polycaprolactone-polyurethane(PCL-PU)bilayer scaffold in which the inner layer is dense and the outer layer consists of pores,which was mechanically stimulated to promote the secretion of collagen nanofiber from the HBX-HSCs and to facilitate crosslinking with the scaffold.We obtained an ECM-PCL-PU composite bionic blood vessel that could act as access for dialysis after decellularization.Then,the vessel scaffold was implanted into a rabbit's neck arteriovenous fistula model.It exhibited strong tensile strength and smooth blood flow and formed autologous blood vessels in the rabbit's body.Our study demonstrates the use of human cells to create biomimetic dialysis blood vessels,providing a novel approach for creating clinical vascular access for dialysis.

ObjectiveTriple-negative breast cancer (TNBC) is the breast cancer subtype with the worst prognosis, and lacks effective therapeutic targets. Colony stimulating factors (CSFs) are cytokines that can regulate the production of blood cells and stimulate the growth and development of immune cells, playing an important role in the malignant progression of TNBC. This article aims to construct a novel prognostic model based on the expression of colony stimulating factors-related genes (CRGs), and analyze the sensitivity of TNBC patients to immunotherapy and drug therapy. MethodsWe downloaded CRGs from public databases and screened for differentially expressed CRGs between normal and TNBC tissues in the TCGA-BRCA database. Through LASSO Cox regression analysis, we constructed a prognostic model and stratified TNBC patients into high-risk and low-risk groups based on the colony stimulating factors-related genes risk score (CRRS). We further analyzed the correlation between CRRS and patient prognosis, clinical features, tumor microenvironment (TME) in both high-risk and low-risk groups, and evaluated the relationship between CRRS and sensitivity to immunotherapy and drug therapy. ResultsWe identified 842 differentially expressed CRGs in breast cancer tissues of TNBC patients and selected 13 CRGs for constructing the prognostic model. Kaplan-Meier survival curves, time-dependent receiver operating characteristic curves, and other analyses confirmed that TNBC patients with high CRRS had shorter overall survival, and the predictive ability of CRRS prognostic model was further validated using the GEO dataset. Nomogram combining clinical features confirmed that CRRS was an independent factor for the prognosis of TNBC patients. Moreover, patients in the high-risk group had lower levels of immune infiltration in the TME and were sensitive to chemotherapeutic drugs such as 5-fluorouracil, ipatasertib, and paclitaxel. ConclusionWe have developed a CRRS-based prognostic model composed of 13 differentially expressed CRGs, which may serve as a useful tool for predicting the prognosis of TNBC patients and guiding clinical treatment. Moreover, the key genes within this model may represent potential molecular targets for future therapies of TNBC.

Objective To investigate the impacts of different levels(1,3 and 5)of iDream reconstruction on CT quantitative analysis of lung function parameters,providing references for quantitative measurement of emphysema indicators by iDream reconstruction technology.Methods A retrospective study was performed for 50 patients who underwent noncontrast chest CT scan in some hospital from December 2021 to January 2022,and the images were reconstructed using four methods:fittered back projection(FBP)and level 1,3 and 5 iDream techniques.For the four groups of images,the main tracheal CT values and standard deviation(SD)values were measured,the signal to noise ratio(SNR)was calculated and the total lung volume(TLV),emphysema volume(EV),emphysema index(EI),15th percentile of lung attenuation(Perc 15)and pulmonary density 15％(PD15％)were detected with quantitative lung function analysis software.Statistical analysis was performed using SPSS 24.0 software.Results The four groups did not have significant differences in the main tracheal CT value and TLV(P＞0.05),while did in SD,SNR,EV,EI,PD15％and Perc 15(P＜0.05).As the reconstruction level of iDream increased,the main tracheal SD value,EV and EI decreased gradually,and level 3 and 5 iDream reconstruction groups had no significant differences in EV and El(P＞0.05);as the reconstruction level of iDream increased,PD15％and Perc 15 rose gradually,and level 3 and 5 iDream reconstruction groups had no significant differences in PD15％and Perc 15(P＞0.05).Conclusion Increase of the level of iDream reconstruction algorithm affects the results of CT quantitative analysis of lung function by reducing image noise.Level 3 and 5 iDream reconstruction ensures the stability of EV,EI,PD15％and Perc 15,which are not influenced by the strength of the iterative reconstruction algorithm.[Chinese Medical Equipment Journal,2024,45(9):57-61]

Objective To investigate the differential expression of miR-124-3p in peripheral blood and clinical sig-nificance of patients with β-thalassemia.Methods Peripheral blood samples were collected from 33 patients with β-thalassemia and 30 healthy controls in Ningde Municipal Hospital Affiliated to Ningde Normal University from June 2021 to August 2022.The expression level of miR-124-3p was detected.Luciferase reporter gene was used to verify the interaction between miR-124-3p and ERF 3'UTR.The correlation between differential expression of miR-124-3p and β-thalassemia was analyzed and the clinical diagnostic value of miR-124-3p for β-thalassemia was eval-uated.Results Compared with healthy control individuals,the expression of miR-124-3p was significantly up-reg-ulated in patients with β-thalassemia(P＜0.001).The genotype of miR-124-3p high expression group was 84.2%β0(16/19),the genotype of low expression group was 55.6%β+(10/18).ROC curve analysis showed that miR-124-3p had predictive efficacy for β-thalassemia(AUC:0.842).Luciferase reporter gene analysis showed that ERF gene was the regulatory target of miR-124-3p.Conclusions The differential expression of miR-124-3p in patients with β-thalassemia is closely related to the genotype and clinical severity of thalassemia,and ERF is negatively reg-ulated by miR-124-3p.miR-124-3p may be an effective diagnostic biomarker for β-thalassemia.

Objective To investigate the role and underlying mechanisms of miR-34a/SIRT1 in intensive care unit acquired weakness(ICU-AW).Methods(1)C2C12 mouse skeletal muscle cells were induced to differentiate into myotubes,and were divided into two groups:model group[ICU-AW group,treated with lipopolysaccharides(LPS)for 12 hours]and normal control group(treated with the same amount of sterile water for 12 hours).Western blotting was used to detect the protein expression level of Muscle ring finger 1(MuRF-1),atrophy gene 1(Atrogin-1)and Sirtuin-1(SIRT1).RT-qPCR was used to assess the mRNA expression level of microRNA-34a(miR-34a),MuRF-1,Atrogin-1 and SIRT1,and light microscope was used to observe the growth and differentiation of C2C12 skeletal muscle cells in each group.(2)ICU-AW cells were further subdivided into control group(treated with siRNA transfection agent intervention),Scra siRNA group(treated with transfection agent and non-specific siRNA),miR-34a siRNA group(treated with transfection agent and specific siRNA intervention),vehicle group(treated with agonist solvent dimethyl sulfoxide)and SRT1720 group(treated with SIRT1 agonist SRT1720).Western blotting was used to detect the protein expression level of SIRT1,Atrogin-1 and MuRF-1 in each group.RT-qPCR was used to detect the miR-34a and the mRNA expression level of SIRT1,Atrogin-1 and MuRF-1 in each group.(3)In addition,another group of ICU-AW cells were divided into control group(treated with siRNA transfection),miR-34a siRNA group(treated with transfection agent and specific siRNA intervention),miR-34a siRNA+vehicle group(treated with transfection agent,specific siRNA and Dimethyl sulfoxide intervention)and miR-34a siRNA+EX-527 group(treated with transfection agent,specific siRNA and SIRT1 inhibitor EX-527).Western blotting was used to detect the protein expression level of Atrogin-1 and MuRF-1.RT-qPCR was used to assess the mRNA expression level of Atrogin-1 and MuRF-1.Results Myotube differentiation was observed on the 4th day.Compared with control group,myotube atrophy was obvious in ICU-AW group.RT-qPCR and Western blotting results revealed that,compared with normal control group,in ICU-AW group,the mRNA and protein expression levels of Atrogin-1 and MuRF-1 significantly increased(P＜0.05),and the expression level of miR-34a significantly increased(P＜0.05),while the mRNA and protein expression levels of SIRT1 significantly decreased(P＜0.05).RT-qPCR results showed that,compared with control group(treated with siRNA transfection agent intervention)and Scra siRNA group,the expression of miR-34a and mRNA expression of Atrogin-1 and MuRF-1 in miR-34a siRNA group significantly decreased(P＜0.05),while the mRNA expression of SIRT1 significantly increased(P＜0.05),meanwhile the protein expression of Atrogin-1 and MuRF-1 decreased significantly(P＜0.01),and the protein expression of SIRT1 significantly increased(P＜0.05).RT-qPCR results also showed that,compared with vehicle group,the mRNA expression of Atrogin-1 and MuRF-1 in SRT1720 group decreased significantly(P＜0.05),while SIRT1 increased significantly(P＜0.05).Western blotting results demonstrated that,compared with control group and Scra siRNA group,the protein expression of Atrogin-1 and MuRF-1 in miR-34a siRNA group decreased significantly(P＜0.05),while SIRT1 increased significantly(P＜0.05).RT-qPCR and Western blotting results indicated that,compared with miR-34a siRNA+vehicle group,the mRNA and protein expression of Atrogin-1 and MuRF-1 in miR-34a siRNA+EX-527 group increased significantly(P＜0.05).Conclusion Overactivation of miR-34a in ICU-AW contributes to skeletal muscle atrophy by inhibiting the expression of SIRT1,which may play an important role in the pathogenesis of ICU-AW.

Objective To understand the change in distribution and antimicrobial resistance of bacteria isolated from blood specimens of Hunan Province,and provide for the initial diagnosis and treatment of clinical bloodstream infection(BSI).Methods Data reported from member units of Hunan Province Antimicrobial Resistance Survei-llance System from 2012 to 2021 were collected.Bacterial antimicrobial resistance surveillance method was imple-mented according to the technical scheme of China Antimicrobial Resistance Surveillance System(CARSS).Bacteria from blood specimens and bacterial antimicrobial susceptibility testing results were analyzed by WHONET 5.6 soft-ware and SPSS 27.0 software.Results A total of 207 054 bacterial strains were isolated from blood specimens from member units in Hunan Province Antimicrobial Resistance Surveillance System from 2012 to 2021,including 107 135(51.7％)Gram-positive bacteria and 99 919(48.3％)Gram-negative bacteria.There was no change in the top 6 pathogenic bacteria from 2012 to 2021,with Escherichia coli(n=51 537,24.9％)ranking first,followed by Staphylococcus epidermidis(n=29 115,14.1％),Staphylococcus aureus(n=17 402,8.4％),Klebsiella pneu-moniae(17 325,8.4％),Pseudomonas aeruginosa(n=4 010,1.9％)and Acinetobacter baumannii(n=3 598,1.7％).The detection rate of methicillin-resistant Staphylococcus aureus(MRSA)decreased from 30.3％in 2015 to 20.7％in 2021,while the detection rate of methicillin-resistant coagulase-negative Staphylococcus(MRCNS)showed an upward trend year by year(57.9％-66.8％).No Staphylococcus was found to be resistant to vancomy-cin,linezolid,and teicoplanin.Among Gram-negative bacteria,constituent ratios of Escherichia coli and Klebsiella pneumoniae were 43.9％-53.9％and 14.2％-19.5％,respectively,both showing an upward trend(both P＜0.001).Constituent ratios of Pseudomonas aeruginosa and Acinetobacter baumannii were 3.6％-5.1％and 3.0％-4.5％,respectively,both showing a downward trend year by year(both P＜0.001).From 2012 to 2021,resistance rates of Escherichia coli to imipenem and ertapenem were 1.0％-2.0％and 0.6％-1.1％,respectively;presenting a downward trend(P＜0.001).The resistant rates of Klebsiella pneumoniae to meropenem and ertapenem were 7.4％-13.7％and 4.8％-6.4％,respectively,presenting a downward trend(both P＜0.001).The resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii to carbapenem antibiotics were 7.1％-15.6％and 34.7％-45.7％,respectively.The trend of resistance to carbapenem antibiotics was relatively stable,but has de-creased compared with 2012-2016.The resistance rates of Escherichia coli to the third-generation cephalosporins from 2012 to 2021 were 41.0％-65.4％,showing a downward trend year by year.Conclusion The constituent ra-tio of Gram-negative bacillus from blood specimens in Hunan Province has been increasing year by year,while the detection rate of carbapenem-resistant Gram-negative bacillus remained relatively stable in the past 5 years,and the detection rate of coagulase-negative Staphylococcus has shown a downward trend.

Objective To investigate changes in the distribution and antimicrobial resistance of bacteria isolated from cerebrospinal fluid(CSF)specimens in Hunan Province,and provide reference for correct clinical diagnosis and rational antimicrobial use.Methods Data reported by member units of Hunan Province Antimicrobial Resistance Surveillance System from 2012 to 2021 were collected according to China Antimicrobial Resistance Surveillance Sys-tem(CARSS)technical scheme.Data of bacteria isolated from CSF specimens and antimicrobial susceptibility tes-ting results were analyzed with WHONET 5.6 and SPSS 20.0 software.Results A total of 11 837 bacterial strains were isolated from CSF specimens from member units of Hunan Province Antimicrobial Resistance Surveillance Sys-tem from 2012 to 2021.The top 5 strains were coagulase-negative Staphylococcus(n=6 397,54.0％),Acineto-bacter baumannii(n=764,6.5％),Staphylococcus aureus(n=606,5.1％),Enterococcus faecium(n=465,3.9％),and Escherichia coli(n=447,3.8％).The detection rates of methicillin-resistant coagulase-negative Staphyloco-ccus(MRCNS)and methicillin-resistant Staphylococcus aureus(MRSA)were 58.9％-66.3％and 34.4％-62.1％,respectively.No Staphylococcus spp.were found to be resistant to vancomycin,linezolid,and teicoplanin.The de-tection rate of Enterococcus faecium was higher than that of Enterococcus faecalis,and the resistance rates of En-terococcus f aecium to penicillin,ampicillin,high concentration streptomycin and levofloxacin were all higher than those of Enterococcus faecalis(all P=0.001).Resistance rate of Streptococcus pneumoniae to penicillin was 85.0％,at a high level.Resistance rate of Escherichia coli to ceftriaxone was＞60％,while resistance rates to enzyme inhibitors and carbapenem antibiotics were low.Resistance rate of Klebsiella pneumoniae to ceftriaxone was＞60％,to en-zyme inhibitors piperacillin/tazobactam and cefoperazone/sulbactam was＞30％,to carbapenem imipenem and me-ropenem was about 30％.Resistance rates of Acinetobacter baumannii to most tested antimicrobial agents were＞60％,to imipenem and meropenem were 59.0％-79.4％,to polymyxin B was low.Conclusion Among the bac-teria isolated from CSF specimens,coagulase-negative Staphylococcus accounts for the largest proportion,and the overall resistance of pathogenic bacteria is relatively serious.Bacterial antimicrobial resistance surveillance is very important for the effective treatment of central nerve system infection.