This study was aimed at creating an engineered strain of Bacillus subtilis for efficient expression of biologically active type 2 toxin B(TcdB2)derived from a highly virulent strain of Clostridium difficile.The TcdB2 gene was cloned from ST1/RT027 strain genome DNA,incorporated into the PHT01 vector,and then transformed into B.subtilis strain WB800N for prokaryotic expression.Cell toxicity assays revealed that the recombinant TcdB2 exhibited cytotoxic effects in various cells.The engineered B.subtilis strain effectively expressed biologically active TcdB2,thus providing a basis for further exploration of the pathogenic mechanisms of highly virulent strains of C.difficile and establishing a foundation for potential vaccine can-didate targets.

Objective:To explore the efficacy and safety of bortezomib or thalidomide combined with recombinant human erythropoietin(rhEPO)in the treatment of multiple myeloma(MM).Methods:A total of 80 patients with MM who were treated in the Second People's Hospital ofWuhu from January 2013 to December 2018 were selected as the research subjects,and they were divided into bortezomib group(n=40)and thalidomide group(n=40)by the simple randomization method.The bortezomib group received bortezomib regimen combined with rhEPO therapy,and the thalidomide group was given thalidomide regimen combined with rhEPO therapy,and all patients were treated for 3 courses with every 3 weeks as a course of treatment.The clinical efficacy after 3 courses of treatment,and tumor-related biochemical indicators[lactate dehydrogenase(LDH),β 2-microglobulin([3 2-MG),vascular endothelial growth factor(VEGF),apoptosis inhibitory protein Survivin],bone marrow-related indicators[serum M-protein,bone marrow plasma cells,hemoglobin(Hb)]and coagulation function indicators[activated partial thromboplastin time(APTT),prothrombin time(PT),plasminogen activator inhibitor(PAI),total circulating microparticles(TMPs)]before treatment and after 3 courses of treatment were compared between the two groups of patients.The occurrence of adverse reactions during the treatment in the two groups of patients was recorded.Results:After 3 courses of treatment,the ORR rate of 92.5％in bortezomib group was higher than 90.0％in thalidomide group,but the difference was not statistically significant(P＞0.05).The levels of LDH,[3 2-MG,VEGF,Survivin,serum M-protein,bone marrow plasma cells,APTT,PT,PAI and TMPs in the two groups after 3 courses of treatment were significantly lower or shorter than those before treatment,and the above indicators in bortezomib group were significantly lower or shorter than those in thalidomide group(P＜0.05).After 3 courses of treatment,the expression level of Hb in the two groups was significantly higher than that before treatment,and the Hb level in bortezomib group was significantly higher than that in thalidomide group(P＜0.05).During the treatment process,the incidence rates of adverse reactions in bortezomib group were significantly lower than those in thalidomide group(P＜0.05).Conclusion:Thalidomide regimen or bortezomib regimen combined with rhEPO has similar clinical efficacy on MM,but bortezomib regimen combined with rhEPO is more prominent and safer on improving tumor-related biochemical indicators,bone marrow-related indicators and coagulation status in patients with MM.

Objective:To investigate the changes in serum homeobox A9(HOXA9),soluble E-cadherin(SE-CAD)and type Ⅲ procollagen(PCⅢ)levels in acute myeloid leukemia(AML)patients after chemotherapy with DCAG regimen and their relationship with prognosis.Methods:The clinical data of 80 patients with relapsed/refractory AML diagnosed and treated in our hospital from March 2018 to December 2021 were retrospectively analyzed.According to different treatment regimen,the patients were divided into DCAG group(n=40)and CAG group(n=40).The clinical efficacy and changes of HOXA9,SE-CAD and PCⅢ levels before and after treatment were compared.In addition,all patients were divided into remission group(n=58)and non-remission group(n=22)according to the clinical efficacy.Univariate and multivariate analyses were performed to analyze the risk factors affecting the prognosis of AML patients.The predictive efficacy of the three single indicators,HOXA9,SE-CAD,and PC Ⅲ,and their combination on prognosis was analyzed.Results:Compared with before treatment,the levels of HOXA9,SE-CAD and PCⅢ in both the DCAG and CAG groups were decreased after treatment,and the improvement of each indicator and the clinical efficacy in the DCAG group were significantly better than those in the CAG group(all P＜0.05).Multivariate analysis showed that increased bone marrow blast count,HOXA9 mRNA,SE-CAD and PCⅢ levels were independent risk factors affecting the efficacy of chemotherapy in AML patients(all P＜0.05).ROC curves showed that the combination of HOXA9 mRNA,SE-CAD and PCⅢ could effectively predict the prognosis of AML patients,with a sensitivity of 84.80％and a specificity of 88.20％.Conclusion:DCAG regimen can significantly improve the levels of HOXA9 mRNA,SE-CAD and PCⅢ in AML patients,these three indicators are all independent risk factors affecting the prognosis of AML patients,and the combination of the three indicators can effectively predict the prognosis of the patients.

Objective:To investigate the impact of ionizing radiation(IR)on the structure and function of the testis and pro-vide some strategies for the prevention and treatment of IR-induced damage(IRD).Methods:Using radiation dose simulation,se-men analysis,hormone testing,electron microscopy and single-cell transcriptome sequencing,we assessed and analyzed a case of IRD.We established a mouse model of IRD to validate the results of single-cell sequencing,and investigated the specific biological mecha-nisms of IRD and potential strategies for its intervention.Results:IR at 1-2 Gy significantly reduced sperm concentration and mo-tility,which gradually recovered after 12 months but the percentage of morphologically normal sperm remained low.It also caused im-balanced levels of various steroid hormones,decreased testosterone and dehydroepiandrosterone sulfate,increased progesterone,prolac-tin,luteinizing hormone,and follicle-stimulating hormone.Electron microscopy revealed damages to the testis structure,including loss of germ cells,atrophy of the seminiferous tubules,nuclear membrane depression of the spermatocytes,mitochondrial atrophy and de-formation,and reduction of mitochondrial cristae.Single-cell sequencing indicated significant changes in the function of the Leydig cells and macrophages and disrupted lipid-related metabolic pathways after IRD.Administration of L-carnitine to the mouse model im-proved lipid metabolism disorders and partially alleviated IRD to the germ cells.Conclusion:Ionizing radiation can cause disorders of testicular spermatogenesis and sexual hormones and inhibit lipid metabolism pathways in Leydig cells and macrophages.Improving lipid metabolism can alleviate IRD to germ cells.

Objective To carry out rigid-body inverse dynamics modelling and analysis of a self-designed 6RSS parallel bio-inspired masticatory robot.Methods Firstly,the functions of kinematic variables including translational/rotational velocities and accelerations were derived for rigid-body inverse dynamics modelling.Secondly,the rigid-body inverse dynamics model was established with the Newton-Euler's law.Finally,the chewing motion trajectories of the oral health volunteers were tracked and numerical calculations were carried out in the case where the robot was subjected to a chewing reaction force.Results Numerical calculations showed that the driving torque and the constraint force of the robot peaked when the chewing reaction force was at its maximum.Conclusion The external force has a large impact on the inverse dynamics of the robot,and theoretical references are provided for the motion control and optimal design of the robot.[Chinese Medical Equipment Journal,2024,45(3):16-22]

Animals ; Callithrix ; Sex Factors ; Vocalization, Animal ; Sex Characteristics

Objective To investigate the inhibitory effects of Wumeiwan on oxidative stress injury of ulcerative colitis mice induced by dextran sulfate sodium(DSS)by regulating Kelch-like ECH related protein 1(Keap-1)-nuclear factor E2 related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathwayand.Methods Forty C57BL/6 mice were randomly divided into five groups:normal group,model group,positive control group,experimental-L,-H groups.UC mice model were induced by free access to 2％DSS water.Mice in normal and model group were orally administered with 0.9％NaCl,mice in positive control group were orally treated with Mesalazine solution(0.005 g·10 g-1·d-1),while mice in experimental groups were orally administered with Wumeiwan decoction at the dose of 0.13 and 0.26 g·10 g-1·d-1,respectively.All the drugs were administered for consecutive 7 days,1 times a day.The levels of disease activity index(DAI)and the colon length were scored.The levels of superoxide dismutase(SOD),catalase(CAT),cyclooxygenase-2(COX-2)and inducible nitric oxide synthase(iNOS)in colon tissue of mice were determined by real-time fluorescence quantitative polymerase chain reaction(qRT-PCR)method.The level of Keap-1,Nrf2,HO-1 proteins in colon tissue were determined by Western blot method.Results The levels of DAI of seventh day in normal group,positive control group,experimental-L,-H groups were 0、(2.62±0.33),(1.87±0.35),(1.87±0.35)and(1.58±0.35);the colon lengths were(8.16±0.47)、(5.98±0.24),(7.58±0.38),(7.33±0.24)and(7.48±0.51)cm;the SOD mRNA were 1.01±0.16、0.40±0.01,1.43±0.45,0.65±0.01 and 0.83±0.02;the CAT mRNA were 1.01±0.20、0.45±0.01,0.84±0.02,0.68±0.07 and 0.87±0.05;the COX-2 mRNA were 1.03±0.33、16.65±0.60,4.78±0.25,14.07±0.60 and 7.39±0.15;the iNOS mRNA were 1.04±0.40、20.71±0.66,8.09±0.93,15.44±0.68 and 11.66±0.06;the levels of Keap-1 were 1.22±0.16、1.10±0.05,1.18±0.05,1.94±0.08 and 1.17±0.08;the levels of Nrf2 were 1.12±0.16、0.76±0.15,0.65±0.13,0.70±0.16 and 0.82±0.18;the levels of HO-1 were 1.34±0.15、1.00±0.12,0.89±0.10,1.50±0.18 and 1.40±0.13,respectively.Significant difference was found between normal group and model group(P＜0.01,P＜0.05);significant difference was also found between the experimental-L,-H groups and model group(P＜0.01,P＜0.05).Conclusion Wumeiwan can inhibit oxidative stress in mice with UC,the mechanisms may be related to adjusted the expression of Keap-1-Nrf2/HO-1 signaling pathway protein in colon.

ObjectiveRecent successful restoration of the native conformation and function of the complementary-determining regions (CDRs) of antibodies on gold nanoparticles (AuNPs) demonstrates that the era of molecular conformational engineering is dawning. Basically, molecular conformational engineering aims to precisely tune flexible non-functional molecules into special conformations to carry out novel functions, in the same way as protein folding. In order to explore the general applicability of molecular conformational engineering, as well as to reveal the mechanism of protein structure-function relationship, the objective of this work is to restore the native conformation and function of the CDRs of an antibody on platinum nanoparticles (PtNPs). MethodsThe CDR fragment of the anti-lysozyme antibody cAB-lys3, which has no stable conformation or function in free state, was conjugated onto the surface of PtNPs through two Pt-S bonds. The original antigen-recognizing function of the CDR restored on PtNPs was assessed by the specific inhibition of the enzymatic activity of lysozyme by the PtNP-CDR conjugates. ResultsAfter optimization of the peptide density on the surface of PtNPs and modification of PtNPs with polyethylene glycol (PEG), the resulted PtNP-based hybrid artificial antibody (PtNP-10PEG-30P1), dubbed Platinumbody, could bind specifically to lysozyme and significantly inhibit the activity of lysozyme. ConclusionThis is the first time that the fragment of a protein could refold on PtNPs. Together with the previous Goldbody and Silverbody, current work demonstrates that artificial proteins could be generally created by restoration of the native conformation of natural proteins fragments on NPs.

Objective This study aimed to explore the potential targets of Yishenqingli Formula in treating idiopathic membranous nephropathy(IMN)using a combination of liquid chromatography-mass spectrometry(LC-MS)analysis and network pharmacology.Methods The active ingredients of the Yishen Qingli Formula were identified through the BATMAN-TCM database and LC-MS qualitative analysis.The biological processes and mechanism pathways of the Yishen Qingli Formula in treating IMN were predicted using network pharmacology,and molecular docking and in vitro,experiments were conducted to verify the selected core targets.The core targets were selected and validated through molecular docking and in vitro experiments.Results A total of 15 active ingredients were selected from the Yishen Qingli Formula,and 72 core genes were obtained by intersecting its target with the IMN disease target.GO enrichment analysis results showed that the regulation of apoptosis signaling pathway,white cell migration,peptide tyrosine phosphorylation,and so on were involved;The KEGG pathway enrichment analysis results showed that the treatment of IMN with Yishen Qingli Formula involves apoptosis-related signaling pathways such as TNF,PI3K/AKT,MAPK,etc.In vitro,experiments have shown that Yishen Qingli Formula can reduce podocyte apoptosis by regulating the PI3K/AKT pathway.Conclusion Yishen Qingli Formula is a treatment for idiopathic membranous nephropathy through multiple targets and pathways.It has an anti-apoptotic effect on the C5b-9 induced podocyte sub-lysis model,and its mechanism of action may be related to the TNF,PI3K/AKT,MAPK signaling pathways.

Objective This study analyzes the risk points in the quality control of bioink and the main processes of bioprinting,clarifies and explores the quality control and supervision model for bioprinting medical devices,and provides theoretical and practical guidance to ensure the safety and effectiveness of bioprinting medical devices.Methods The quality control risk points throughout the bioprinting process were comprehensively analyzed,with a particular focus on bioprinting materials and key processes.The regulatory model and methods for bioprinting medical devices were examined.This research concentrated on critical technologies such as extrusion,laser-assisted,and in situ bioprinting,assessing their potential for clinical applications and regulatory challenges.Results Bioink from different sources should meet regulatory requirements.It is essential to ensure aseptic handling of raw materials and to validate sterilization under"worst-case"conditions.Conclusion As bioprinting technology advances rapidly,corresponding research into materials,processes,and quality risk control should be conducted to ensure the concurrent development of the regulatory system.This will continuously contribute to the orderly progression of the entire industry and human health.