BACKGROUND:Quercetin plays an important role in the proliferation and differentiation of bone marrow mesenchymal stem cells,but less research has been done on its mechanism of promoting the migration of bone marrow mesenchymal stem cells. OBJECTIVE:To study the effect of quercetin on the migration of human bone marrow mesenchymal stem cells through in vitro experiments,and to explore the regulatory role of CCR1 and CXCR4. METHODS:Human bone marrow mesenchymal stem cells were selected as experimental subjects.CCK8 assay was used to detect the effect of quercetin on the proliferative activity of human bone marrow mesenchymal stem cells.Cell scratch assay and Transwell assay were used to detect the in vitro invasive and migratory abilities of human bone marrow mesenchymal stem cells after quercetin treatment,respectively.The role of quercetin in relation to CCR1 and CXCR4 was demonstrated with the help of molecular docking technology.Western blot assay and real-time fluorescence quantitative PCR were used to detect the migration-related chemokine expression after quercetin treatment. RESULTS AND CONCLUSION:(1)5 and 10 μmol/L quercetin could significantly promote the proliferation of human bone marrow mesenchymal stem cells,and the drug concentration of 10 μmol/L resulted in the highest cell proliferation efficiency.(2)To better explore the dose-effect relationship of quercetin affecting the migration of human bone marrow mesenchymal stem cells,5 and 10 μmol/L quercetin were selected for the subsequent experiments,and ligustrazine was used as the positive control drug,and the experiments were divided into blank control group,5 μmol/L quercetin group,10 μmol/L quercetin group,and 100 μmol/L ligustrazine group.(3)In vitro migration and invasion ability of human bone marrow mesenchymal stem cells were elevated in a concentration-dependent manner after quercetin treatment,and the migration effect of 10 μmol/L quercetin group was better than that of ligustrazine group.(4)The molecular docking results suggested that there was a strong interaction between quercetin and CCR1 and CXCR4.(5)Quercetin could up-regulate the expression of CCR1 and CXCR4 proteins and mRNA.(6)This study confirmed at the cellular level that quercetin could promote the migration of human bone marrow mesenchymal stem cells by targeting CCR1 and CXCR4.

In order to solve the problem of resistance of Pseudomonas aeruginosa to multiple antibiotics, it is an effective way to find inhibitors of P. aeruginosa efflux pump. In this study, 15 new ornithine peptidomimetic derivatives were designed and synthesized by changing the side chain structure of natural amino acids with PAβN, a dipeptide efflux pump inhibitor, and their synergic activity with aztreonam, a monocyclic β-lactam antibiotic, against P. aeruginosa was evaluated. Among them, the representative compound 12b not only enhanced the antibacterial activity of β-lactam antibiotics aztreonam, ceftazidime and meropenem, but also significantly enhanced the antibacterial action of macrolide antibiotics clarithromycin, showing a broad-spectrum synergic sensitization effect. In addition, compound 12b also has a good safety. Preliminary mechanisms suggest that 12b works by directly targeting the efflux transporter MexB. These results provide a new lead compound for the development of a new class of efflux pump inhibitors against P. aeruginosa.

Endodontic diseases are a kind of chronic infectious oral disease.Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha.However,it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy(RCT).Recent research,encompassing bacterial etiology and advanced imaging techniques,contributes to our understanding of the root canal system's anatomy intricacies and the technique sensitivity of RCT.Success in RCT hinges on factors like patients,infection severity,root canal anatomy,and treatment techniques.Therefore,improving disease management is a key issue to combat endodontic diseases and cure periapical lesions.The clinical difficulty assessment system of RCT is established based on patient conditions,tooth conditions,root canal configuration,and root canal needing retreatment,and emphasizes pre-treatment risk assessment for optimal outcomes.The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT.These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.

Objective::To observe the clinical efficacy of modified Simiaosan on synovitis of knee joint with damp-heat obstruction collateral syndrome and the effect on inflammatory factors and neuropeptide substances in synovial fluid. Method::One hundred and thirty-five patients were randomly divided into control group(67 cases) and observation group(68 cases) by random number table. Patients' intra-articular effusion was drawn out. Triamcinolone acetonide was injected into arthrosis for 2 times, 1 time/week, and aceclofenac sustained-release tablets were given for 4 weeks, 0.2 g/time, 1 time/day. In addition to the therapy of control group, patients in observation group were also given modified Simiaosan for 4 weeks, 1 dose/day. Before and after treatment, pain, swelling of knee joint and were scored, Western Ontario and McMaster University (WOMAC) were adopted for scoring knee score, and damp-heat obstruction syndrome and local signs of knee joint were also assessed. And levels of interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor-alpha (TNF-alpha), hypersensitive C-reactive protein (hs-CRP), substance P (SP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) were detected. Result::After treatment, scores of pain and swelling of knee joint in observation group were lower than those in control group (P<0.01). Scores of WOMAC, the total score, integral of damp-heat obstruction collateral syndrome, knee flexion-extension range score and floating patella test were all lower than those in control group (P<0.01). And levels of IL-1β, IL-6, TNF-α, hs-CRP, SP, CGRP, NPY and VIP were all lower than those in control group (P<0.01). Analyzed by rank sum test, the clinical efficacy in observation group was better than those in control group (Z=2.089, P<0.05). Conclusion::Modified Simiaosan can significantly alleviate pain and swelling symptoms, promote the recovery of knee joint function, and inhibit the expressions of proinflammatory factors and neuropeptides in synovial fluid, with a better clinical efficacy.