Intervertebral disc degeneration (IDD) is largely attributed to impaired endogenous repair. Nucleus pulposus-derived stem cells (NPSCs) senescence leads to endogenous repair failure. Small extracellular vesicles/exosomes derived from mesenchymal stem cells (mExo) have shown great therapeutic potential in IDD, while whether mExo could alleviate NPSCs senescence and its mechanisms remained unknown. We established a compression-induced NPSCs senescence model and rat IDD models to evaluate the therapeutic efficiency of mExo and investigate the mechanisms. We found that mExo significantly alleviated NPSCs senescence and promoted disc regeneration while knocking down thioredoxin (TXN) impaired the protective effects of mExo. TXN was bound to various endosomal sorting complex required for transport (ESCRT) proteins. Autocrine motility factor receptor (AMFR) mediated TXN K63 ubiquitination to promote the binding of TXN on ESCRT proteins and sorting of TXN into mExo. Knocking down exosomal TXN inhibited the transcriptional activity of nuclear factor erythroid 2-related factor 2 (NRF2) and activator protein 1 (AP-1). NRF2 and AP-1 inhibition reduced endogenous TXN production that was promoted by exosomal TXN. Inhibition of NRF2 in vivo diminished the anti-senescence and regenerative effects of mExo. Conclusively, AMFR-mediated TXN ubiquitination promoted the sorting of TXN into mExo, allowing exosomal TXN to promote endogenous TXN production in NPSCs via TXN/NRF2/AP-1 feed-forward circuit to alleviate NPSCs senescence and disc degeneration.

Objective To analyze the clinical characteristics and treatment of clostridium difficile infection(CDI)in children.Methods The clinical data of 159 children with CDI admitted to the Department of Gastroenterology and Hepatology,Shanghai Children's Hospital,School of Medicine,Shanghai Jiao Tong University from September 2014 to October 2022 were retrospectively analyzed.All ini-tial CDI patients were divided into vancomycin treatment group and metronidazole treatment group according to different treatment meth-ods,Children with recurrent CDI(RCDI)were divided into two groups according to vancomycin or FMT treatment.Results A total of 159 children with initial CDI were included,including 93 males and 66 females,the age of these children was 4.3(1.7,8.0)years.109 children(68.55％)were treated with metronidazole,and 50 children(31.45％)were treated with vancomycin.Recurrence occurred in 51 children after antibiotic treatment,37 children(33.94％)of them treated with metronidazole,and 14 children(28.00％)of them treated with vancomycin,there was no significant difference(P＞0.05).Among RCDI children,21 cases were treated with vancomycin and 30 were treated with FMT.The cure rate of FMT was 90.00％,and the cure rate of vancomycin was 57.14％.The cure rate of FMT was significantly higher than that of vancomycin.There were no serious adverse events reported after two months of FMT treatment.Conclusion Metronidazole can be used as the drug of choice for initial CDI in children.The cure rate of FMT for RCDI is superior to vancomycin treatment.

Objective To explore the relationship between serum miRNA-21 and miR-27b levels and prognosis of patients with renal clear cell carcinoma.Methods A total of 118 patients with renal clear cell carcinoma admitted to the Qinghai University Hospital from February 2019 to April 2021 were selected as the study subjects,and another 118 healthy patients in the same period as the control group.Real time fluorescence quantitative polymerase chain reaction(PCR)was used to detect the expression of miR-21 and miR-27b in the serum of all subjects.The relative expression levels of serum miR-21 and miR-27b between the patients with renal clear cell carcinoma and healthy control patients were compared.The expression and correlation of serum miR-21 and miR-27b in the patients with renal clear cell carcinoma of different pathological stages and Fuhrman grading were analyzed.The relationship between the expression of serum miR-21 and miR-27b and the survival and prognosis of the patients was explored as well.Results The expression levels of serum miR-21 and miR-27b in the patients with renal clear cell carcinoma were higher than those in the healthy control group(P＜0.05).The serum miR-21 expression level in stage Ⅲ patients was higher than in stageⅠ(P＜0.05),while the serum miR-21 expression level in the stage Ⅳ patients was higher than that in stagesⅠ,Ⅱ,and Ⅲ(P＜0.05).The expression level of miR-27b in the serum of patients gradually increased across the four stages,with a significant difference(P＜0.05).The pathological staging was positively correlated with the expression of miR-21 and miR-27b(P＜0.001).The expression levels of miR-21 and miR-27b in serum of patients gradually increased across grades Ⅰ,Ⅱ and Ⅲ by Fuhrman grading,with significant difference(P＜0.05).Fuhrman grading was positively correlated with the serum miR-21 and miR-27b expression(P＜0.001).There was a statistically significant difference in the survival curve between the miR-21 high expression group and the low expression group(P＜0.05).There was a statistically significant difference in the survival curve between the high expression group and the low expression group of miR-27b(P＜0.05).Conclusion The expression levels of serum miR-21 and miR-27b in patients with renal clear cell carcinoma is indicative of the progression and prognosis of the patient's condition.

Photon Counting Detector(PCD)is a device used to detect X-ray photons,which can directly convert the energy of photons into electrical signals to achieve photon counting and measurement.PCD-based energy spectrum computed tomography(PCD-CT)technology can provide additional energy spectral imaging information,and improve imaging quality while reducing radiation dose.Compared with energy integrating detectors(EID),PCD has advantages of high energy conversion efficiency,good imaging quality,exquisite structural design,and wide application range.It has broad application prospects in ultra-low-dose CT,specific disease diagnosis,and industrial inspection.The application of PCD-CT in spectral CT imaging was reviewed to provide a useful reference for its application in clinical medical diagnosis and industrial applications.

【Objective】 To explore the the potential risks of antiretroviral therapy(ART) drugs on blood safety among blood donors in Shenzhen. 【Methods】 High pressure liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was used to measure ART drugs concentrations in the plasma of regular blood donors (negative control group, n=86) and anti-HIV positive individuals (experimental group, n=98, detected from approximately 440 000 blood donors during 2019—2023). The baseline plasma concentrations of ART drugs in the negative control group were clarified, and the impact of ART drugs on blood safety was analyzed. 【Results】 The baseline concentrations of ART drugs were not detected in 86 samples of negative control group. Four positive ART drugs samples were detected in 1∶2 pooled plasma samples of 98 anti-HIV positive blood donors plasma in the resolution test. The ART positive rate of anti-HIV positive donors was 4.08%, with tenofovir, lamivudine and efavirenz detected in three blood donors and lamivudine, lopinavir, ritonavir and zidovudine detected in one blood donor. 【Conclusion】 ART drugs were found among anti-HIV positive blood donors in Shenzhen. Additional research is needed to investigate the motivation of these specific donors, so as to ascertain the groups most susceptible to potential risks, and guarantee blood safety.

Objective To find out the prevalence of antiretroviral therapy(ART)drugs among treponema pallidum(TP)antibody(anti-TP)positive blood donors in Shenzhen,and to assess the blood safety risks brought about by the new trends of human immunodeficiency virus(HIV)diagnosis and treatment.Methods A stratified random sampling method was used to select 60 repeat blood donors(negative control group)who passed blood screening in Shenzhen from March 2019 to January 2023,and 3 people who regularly took known ART drugs were named positive control group,358 anti-TP positive/anti-HIV negative blood do-nors were named experimental group 1,20 anti-TP positive/anti-HIV positive blood donors were named ex-perimental group 2.The liquid chromatography-mass spectrometry(HPLC-MS/MS)was applied to detect the concentration of 8 ART drugs in plasma samples of each group,and the use of ART drugs was analyzed.Re-sults After the positive control group's plasma was diluted with a 1:6 dilution mixture,the ART drugs could still be detected.The positive mixed plasma samples of 1:6 people in Group 1 and Group 2 were split and validation,one ART drug positive sample was detected in Group 2,which was positive for anti-HIV,pro-tein immunoblotting,and HIV RNA.The detection rate of ART drugs in anti-TP positive blood donors was 0.26％,0.00％in Group 1 and 4.00％in Group 2.Conclusion The use of ART drugs has been found among anti-TP positive blood donors in Shenzhen,and people with HIV infection and high-risk sexual behavior are more likely to use antiretroviral drugs.

Objective:To investigate the role and molecular mechanism of sensory neuron-derived exosomes (nExo) in mediating intervertebral disc degeneration (IDD).Methods:A rat IDD model was constructed, with nExo injected into the intervertebral disc. After 4 weeks, the degenerative grades of operated discs were evaluated using histological staining, while the senescent phenotype of nucleus pulposus stem cells (NPSC) in the tissue was evaluated using immunofluorescence staining. For in vitro experiments, 24 hours after the treatment of nExo to NPSC, immunoblotting, flow cytometry, or senescence-associated β-galactosidase staining was applied to evaluate the senescent phenotype of NPSC. Transcriptomics analysis was applied to identify the key molecules that mediate nExo-induced cells senescence. After 4 weeks of injecting nExo and TXN into the rat tail disc degeneration model.Results:nExo increased the degenerative grades of IDD and increased the proportion of TEK +p16 + and TEK +p21 + cells (from 36.32% ±4.04%, 33.69% ±4.56% in IDD group to 56.41% ±5.26%, 50.14% ±8.49% in IDD+nExo group, respectively; t=7.420, P<0.001; t=4.184, P<0.0019, respectively) in the disc tissue. Besides, nExo promoted the expression of p16 and p21 in NPSC and increased the percentage of cells with positive senescence-associated β-galactosidase staining (from 7.32%±1.73% to 58.22%±11.38%, t=7.658, P=0.002), while the percentage of G2/M cells was downregulated (from 18.10%±1.32% to 1.60%±0.67%, t=19.290, P<0.001). Transcriptomic analysis showed that the differential genes of CTRL vs. nExo were closely related to cell senescence, and TXN was screened by intersecting the differential gene set with the cellular senescence gene sets from the published database. Furthermore, we verified that nExo decreased the content of TXN in NPSC, while exogenous TXN downregulated the expression of p16 and p21 in NPSC, reduced the positive cell rate of senescence-associated β-galactosidase staining (from 58.84%±3.99% to 21.68%±8.16%, t=7.048, P=0.021), increased the percentage of G2/M cells (from 1.21%±0.34% to 15.26%±2.60%, t=9.259, P=0.001). TXN significantly reduced the grade of disc tissue degeneration (histological score: 14.33±0.82 in the nExo group; 8.17±1.17 in the nExo+TXN group, t=10.590, P<0.001), significantly increased the content of extracellular matrix (from 10.94±4.35 μg/mg to 50.55±12.16 μg/mg, t=7.512, P<0.001), and reduced the proportion of TEK +p16 + and TEK +p21 + double-positive cells (from 54.92%±4.21% and 60.31%±9.02% to 27.93%±3.26% and 33.75%±8.07%, respectively; t=12.430, P<0.001; t=5.375, P<0.001, respectively). Conclusion:nExo promotes cell senescence and IDD by downregulating TXN in NPSC.

Squamosa promoter binding protein-like (SPL) family is a group of important transcription factors involved in the regulation of plant growth and development and the response to environmental stress, but there are few studies in perennial fruit trees such as citrus. In this study, Ziyang Xiangcheng (Citrus junos Sib.ex Tanaka), an important rootstock of Citrus, was used as the material for analysis. Based on plantTFDB transcription factor database and sweet orange genome database, 15 SPL family members were genome-widely identified and cloned from Ziyang Xiangcheng, and named CjSPL1-CjSPL15. Sequence analysis showed that the open reading frame (ORF) length of CjSPLs ranged from 393 bp to 2 865 bp, encoding 130-954 amino acids. Phylogenetic tree divided 15 CjSPLs into 9 subfamilies. Gene structure and conserved domain analysis predicted 20 different conserved motifs and SBP basic domains. Analysis of cis-acting promoter elements predicted 20 different promoter elements, including those related to plant growth and development, abiotic stress and secondary metabolites. The expression patterns of CjSPLs under drought, salt and low temperature stresses were analyzed by real-time fluorescence quantitative PCR (qRT-PCR), and many CjSPLs were significantly up-regulated after stress treatment. This study provides a reference for further study on the function of SPL family transcription factors in citrus and other fruit trees.
Phylogeny ; Transcription Factors/metabolism* ; Gene Expression Regulation, Plant ; Plant Proteins/metabolism* ; Multigene Family ; Stress, Physiological

Objective : To explore the molecular mechanisms of immunosuppressive activity of soluble CD83 (sCD83) . Methods : Bone marrow⁃derived dendritic cells ( DCs) and CD4 + T cells in the spleen were isolated from bone marrow progenitor cells of 6 - 8 ⁃week⁃old C57B/6 mice. DCs and CD4 + T cells were treated with 10 μl PBS (Control group) or 10 μl 10 μg/ml soluble CD83 (sCD83 group) , respectively. Immature DCs (imDCs) in DCs and CD4 + CD25 + FOXP3 + T cells (Treg cells) in CD4 + T cells were determined by flow cytometry. Western blot was used to determine the expression levels of indoleamine 2 ,3 ⁃dioxygenase (IDO) in imDCs and the expression levels of phosphatase and tensin homolog (PTEN) , phosphorylated⁃Akt serine/threonine kinase 1 ( p⁃Akt) , Akt , nucleus NF⁃κB subunit (RelB) , cytoplasm RelB and programmed cell death 1 ( PD⁃1) in Treg cells. ELISA was used to determine the level of kynurenine in DCs culture supernatant , and the levels of interleukin⁃10 ( IL⁃10) , transforming growth factor⁃β (TGF⁃ β) and IL⁃12 in imDCs and CD4 + T cells co⁃culture system. Results: Compared with Control group , the percentage of DCs cell counts expressing the surface markers of CD40 , CD83 , CD86 and major histocompatibility complex class⁃ Ⅱ (MHC Ⅱ ) in sCD83 group decreased (P < 0. 05) , with the level of kynurenine in DCs culture supernatant increased (P < 0. 05) . Compared with Control group , the percentage of Treg cell counts in sCD83 group increased ( P < 0. 05) , with the expression levels of PTEN and cytoplasm RelB enhanced (P < 0. 05) , while the expression levels of p⁃Akt , nucleus RelB and PD⁃1 decreased (P < 0. 05) . There was no significant difference in the expression level of Akt between the two groups. In the imDCs and CD4 +T cells co⁃cultured supernatants , compared with Control group , the levels of IL⁃10 and TGF⁃ β increased , and the level of IL⁃12 decreased in sCD83 group (P < 0. 05) . Conclusion sCD83 can inhibit CD4 + T cells nucleus RelB levels and regulate cytokines secretion so as to have an effects on cellular crosstalk of imDCs and Treg cells and promote imDCs and Treg cells proliferation.

Objective:To understand the macronutrient content and influencing factors of donated breast milk in breast milk bank.Methods:A total of 458 first-time breast milk donors and their donated breast milk from June 2016 to June 2018 in Shanghai were selected as research objects by the convenient sampling method to determine the macronutrient content in donated breast milk. Multiple linear regression was used to analyze the influencing factors of the macronutrient content of donated breast milk.Results:In macronutrient content of 458 donated breast milk, the protein content was (0.95±0.24) g/dl, fat content was (4.03±1.25) g/dl, sugar content was (7.44±0.38) g/dl, dry matter was (12.75±3.16) g/dl and energy content was (71.12±11.33) kcal/dl.The results of multiple linear regression analysis showed that the time of milk donation and infant gender were the influencing factors of protein content in donated breast milk ( P<0.05). The time of milk donation, mode of delivery and season of birth were the influencing factors of the sugar content in donated breast milk ( P<0.05). The time of milk donation was the influence factor of energy content in donated breast milk ( P<0.05) . Conclusions:The content of macronutrients in donated breast milk in this study is lower than the demand for macronutrients in premature infants. The macronutrient composition of donated breast milk varies greatly among individuals, which is related to the time of milk donation, the mode of delivery, the infant gender and birth season of the baby. Therefore, further research is needed on how to add breast milk additives to donated breast milk in the later stage for targeted reinforcement to meet the growth and development needs of premature infants.