The immunomodulatory， repair， and regeneration-promoting functions of mesenchymal stem cells make them one of the potential treatment methods for liver diseases. At present， viral and non-viral delivery methods have been developed to genetically modify mesenchymal stem cells， and gene modification can promote the survival， homing， and cytokine secretion of mesenchymal stem cells， thereby enhancing the ability of mesenchymal stem cells to treat liver diseases. This article mainly summarizes the research advances in gene-modified mesenchymal stem cells in the treatment of liver diseases， in order to provide new insights and strategies for the clinical treatment of liver diseases.

OBJECTIVE To study the improvement effects and mechanism of proanthocyanidins （PACs） on steroid-induced osteonecrosis of the femoral head （SONFH） in rabbits based on the receptor-interacting protein kinase 1 （RIPK1）/RIPK3/mixed lineage kinase domain-like protein （MLKL） signaling pathway. METHODS SONFH model in rabbits was induced by injecting Escherichia coli endotoxin+methylprednisolone. The successfully modeled rabbits were randomly divided into Model group （normal saline）， low-dose PACs group （PACs-L group， 11 mg/kg）， high-dose PACs group （PACs-H group， 22 mg/kg）， high-dose PACs+ RIPK1 activator （rRIPK1） group （PACs-H+rRIPK1 group， 22 mg/kg PACs+4 μg/kg rRIPK1）， along with a control group （normal saline）， with 6 rabbits in each group. Each administration group was given relevant medicine once a day intragastrically/via injection， for 4 consecutive weeks. After the last administration， the levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in rabbit serum were measured. The changes in the microstructure of rabbit femurs， including bone mineral density （BMD）， trabecular thickness （Tb.Th）， trabecular number （Tb.N）， and trabecular separation （Tb. Sp） were examined. The histopathological features of rabbit femoral tissues were observed， and the apoptotic status of cells within the rabbit femoral tissues was detected. The mRNA expressions of vascular endothelial growth factor （VEGF） and bone morphogenetic protein 2 （BMP2） in rabbit femoral tissues were determined. The expressions of RIPK1/RIPK3/MLKL signaling pathway-related proteins in femoral tissues were detected. RESULTS Compared with the Control group， serum contents of TNF-α and IL-6， Tb.Sp， empty bone cavity rate， cell apoptosis rate， phosphorylation levels of RIPK1， RIPK3 and MLKL in femoral tissue were significantly increased in the Model group （P＜0.05）. BMD， Tb.Th， Tb.N， as well as the mRNA expression of VEGF and BMP2， along with protein expression of caspase-8， in the femoral tissues were all decreased （P＜0.05）. The bone cells in the femoral tissue were unevenly distributed， and the trabeculae were arranged sparsely. Compared with the Model group， the aforementioned quantitative indicators （P＜0.05） and pathological changes in all dosage groups of PACs showed significant improvements. Compared with the PACs-H group， the aforementioned quantitative indicators （P＜0.05） and pathological changes in the PACs-H+rRIPK1 group showed significant reversal. CONCLUSIONS PACs can ameliorate SONFH in rabbits， and its mechanism of action may be related to the inhibition of the activation of the RIPK1/RIPK3/MLKL signaling pathway， suppression of apoptosis in femoral tissue cells， and promotion of angiogenesis.

Liver fibrosis is pathological in most chronic liver diseases. Exosomes secreted by mesenchymal stem cells (MSCs) can regulate liver fibrosis through mechanisms such as inhibition of inflammatory response and proliferation of activated hepatic stellate cells, regulation of immune cells and metabolism. Therefore, MSC-derived exosomes can be used as a cell-free therapy for chronic liver disease, expanding new ideas for the treatment of chronic liver disease. Recent researches on MSC-derived exosomes in the treatment of liver fibrosis are reviewed in this article.

Digital intraoral scanning is a hot topic in the field of oral digital technology.In recent years,digital intra-oral scanning has gradually become the mainstream technology in orthodontics,prosthodontics,and implant dentistry.The precision of digital intraoral scanning and the accuracy and stitching of data collection are the keys to the success of the impression.However,the operators are less familiar with the intraoral scanning characteristics,imaging process-ing,operator scanning method,oral tissue specificity of the scanned object,and restoration design.Thus far,no unified standard and consensus on digital intraoral scanning technology has been achieved at home or abroad.To deal with the problems encountered in oral scanning and improve the quality of digital scanning,we collected common expert opin-ions and sought to expound the causes of scanning errors and countermeasures by summarizing the existing evidence.We also describe the scanning strategies under different oral impression requirements.The expert consensus is that due to various factors affecting the accuracy of digital intraoral scanning and the reproducibility of scanned images,adopting the correct scanning trajectory can shorten clinical operation time and improve scanning accuracy.The scanning trajec-tories mainly include the E-shaped,segmented,and S-shaped methods.When performing fixed denture restoration,it is recommended to first scan the abutment and adjacent teeth.When performing fixed denture restoration,it is recommend-ed to scan the abutment and adjacent teeth first.Then the cavity in the abutment area is excavated.Lastly,the cavity gap was scanned after completing the abutment preparation.This method not only meets clinical needs but also achieves the most reliable accuracy.When performing full denture restoration in edentulous jaws,setting markers on the mucosal tissue at the bottom of the alveolar ridge,simultaneously capturing images of the vestibular area,using different types of scanning paths such as Z-shaped,S-shaped,buccal-palatal and palatal-buccal pathways,segmented scanning of dental arches,and other strategies can reduce scanning errors and improve image stitching and overlap.For implant restora-tion,when a single crown restoration is supported by implants and a small span upper structure restoration,it is recom-mended to first pre-scan the required dental arch.Then the cavity in the abutment area is excavated.Lastly,scanning the cavity gap after installing the implant scanning rod.When repairing a bone level implant crown,an improved indi-rect scanning method can be used.The scanning process includes three steps:First,the temporary restoration,adjacent teeth,and gingival tissue in the mouth are scanned;second,the entire dental arch is scanned after installing a standard scanning rod on the implant;and third,the temporary restoration outside the mouth is scanned to obtain the three-di-mensional shape of the gingival contour of the implant neck,thereby increasing the stability of soft tissue scanning around the implant and improving scanning restoration.For dental implant fixed bridge repair with missing teeth,the mobility of the mucosa increases the difficulty of scanning,making it difficult for scanners to distinguish scanning rods of the same shape and size,which can easily cause image stacking errors.Higher accuracy of digital implant impres-sions can be achieved by changing the geometric shape of the scanning rods to change the optical curvature radius.The consensus confirms that as the range of scanned dental arches and the number of data concatenations increases,the scanning accuracy decreases accordingly,especially when performing full mouth implant restoration impressions.The difficulty of image stitching processing can easily be increased by the presence of unstable and uneven mucosal mor-phology inside the mouth and the lack of relatively obvious and fixed reference objects,which results in insufficient ac-curacy.When designing restorations of this type,it is advisable to carefully choose digital intraoral scanning methods to obtain model data.It is not recommended to use digital impressions when there are more than five missing teeth.

Objective:To investigate the value of transanal multipoint full-layer puncture biopsy (TMFP) in predicting pathological complete response (pCR) after neoadjuvant radiotherapy and chemotherapy (nCRT) in patients with locally advanced rectal cancer (LARC) and to establish a predictive model for providing clinical guidance regarding the treatment of LARC.Methods:In this multicenter, prospective, cohort study, we collected data on 110 LARC patients from four hospitals between April 2020 and March 2023: Beijing Chaoyang Hospital of Capital Medical University (50 patients), Beijing Friendship Hospital of Capital Medical University (41 patients), Qilu Hospital of Shandong University (16 patients), and Zhongnan Hospital of Wuhan University (three patients). The patients had all received TMFP after completing standard nCRT. The variables studied included (1) clinicopathological characteristics; (2) clinical complete remission (cCR) and efficacy of TMFP in determining pCR after NCRT in LARC patients; and (3) hospital attended, sex, age, clinical T- and N-stages, distance between the lower margin of the tumor and the anal verge, baseline and post-radiotherapy serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 concentrations, chemotherapy regimen, use of immunosuppressants with or without radiotherapy, radiation therapy dosage, interval between surgery and radiotherapy, surgical procedure, clinical T/N stage after radiotherapy, cCR, pathological results of TMFP, puncture method (endoscopic or percutaneous), and number and timing of punctures. Single-factor and multifactorial logistic regression analysis were used to determine the factors affecting pCR after NCRT in LARC patients. A prediction model was constructed based on the results of multivariat analysis and the performance of this model evaluated by analyzing subject work characteristics (ROC), calibration, and clinical decision-making (DCA) curves. pCR was defined as complete absence of tumor cells on microscopic examination of the surgical specimens of rectal cancer (including lymph node dissection) after NCRT, that is, ypT0+N0. cCR was defined according to the Chinese Neoadjuvant Rectal Cancer Waiting Watch Database Study Collaborative Group criteria after treatment, which specify an absence of ulceration and nodules on endoscopy; negative rectal palpation; no tumor signals on rectal MRI T2 and DWI sequences; normal serum CEA concentrations, and no evidence of recurrence on pelvic computed tomography/magnetic resonance imaging.Results:Of the 110 patients, 45 (40.9%) achieved pCR after nCRT, which was combined with immune checkpoint inhibitors in 34 (30.9%). cCR was diagnosed before puncture in 38 (34.5%) patients, 43 (39.1%) of the punctures being endoscopic. There were no complications of puncture such as enterocutaneous fistulae, vaginal injury, prostatic injury, or presacral bleeding . Only one (2.3%) patient had a small amount of blood in the stools, which was relieved by anal pressure. cCR had a sensitivity of 57.8% (26/45) for determining pCR, specificity of 81.5% (53/65), accuracy of 71.8% (79/110), positive predictive value 68.4% (26/38), and negative predictive value of 73.6% (53/72). In contrast, the sensitivity of TMFP pathology in determining pCR was 100% (45/45), specificity 66.2% (43/65), accuracy 80.0% (88/110), positive predictive value 67.2% (45/67), and negative predictive value 100.0% (43/43). In this study, the sensitivity of TMFP for pCR (100.0% vs. 57.8%, χ 2=24.09, P<0.001) was significantly higher than that for cCR. However, the accuracy of pCR did not differ significantly (80.0% vs. 71.8%, χ 2=2.01, P=0.156). Univariate and multivariate logistic regression analyses showed that a ≥4 cm distance between the lower edge of the tumor and the anal verge (OR=7.84, 95%CI: 1.48-41.45, P=0.015), non-cCR (OR=4.81, 95%CI: 1.39-16.69, P=0.013), and pathological diagnosis by TMFP (OR=114.29, the 95%CI: 11.07-1180.28, P<0.001) were risk factors for pCR after NCRT in LARC patients. Additionally, endoscopic puncture (OR=0.02, 95%CI: 0.05-0.77, P=0.020) was a protective factor for pCR after NCRT in LARC patients. The area under the ROC curve of the established prediction model was 0.934 (95%CI: 0.892-0.977), suggesting that the model has good discrimination. The calibration curve was relatively close to the ideal 45° reference line, indicating that the predicted values of the model were in good agreement with the actual values. A decision-making curve showed that the model had a good net clinical benefit. Conclusion:Our predictive model, which incorporates TMFP, has considerable accuracy in predicting pCR after nCRT in patients with locally advanced rectal cancer. This may provide a basis for more precisely selecting individualized therapy.

Liver fibrosis is pathological in most chronic liver diseases.Exosomes secreted by mes-enchymal stem cells(MSCs)can regulate liver fibro-sis through mechanisms such as inhibition of in-flammatory response and proliferation of activated hepatic stellate cells,regulation of immune cells and metabolism.Therefore,MSC-derived exosomes can be used as a cell-free therapy for chronic liver disease,expanding new ideas for the treatment of chronic liver disease.Recent researches on MSC-de-rived exosomes in the treatment of liver fibrosis are reviewed in this article.

Liver fibrosis is pathological in most chronic liver diseases.Exosomes secreted by mes-enchymal stem cells(MSCs)can regulate liver fibro-sis through mechanisms such as inhibition of in-flammatory response and proliferation of activated hepatic stellate cells,regulation of immune cells and metabolism.Therefore,MSC-derived exosomes can be used as a cell-free therapy for chronic liver disease,expanding new ideas for the treatment of chronic liver disease.Recent researches on MSC-de-rived exosomes in the treatment of liver fibrosis are reviewed in this article.

Liver fibrosis is pathological in most chronic liver diseases.Exosomes secreted by mes-enchymal stem cells(MSCs)can regulate liver fibro-sis through mechanisms such as inhibition of in-flammatory response and proliferation of activated hepatic stellate cells,regulation of immune cells and metabolism.Therefore,MSC-derived exosomes can be used as a cell-free therapy for chronic liver disease,expanding new ideas for the treatment of chronic liver disease.Recent researches on MSC-de-rived exosomes in the treatment of liver fibrosis are reviewed in this article.

Liver fibrosis is pathological in most chronic liver diseases.Exosomes secreted by mes-enchymal stem cells(MSCs)can regulate liver fibro-sis through mechanisms such as inhibition of in-flammatory response and proliferation of activated hepatic stellate cells,regulation of immune cells and metabolism.Therefore,MSC-derived exosomes can be used as a cell-free therapy for chronic liver disease,expanding new ideas for the treatment of chronic liver disease.Recent researches on MSC-de-rived exosomes in the treatment of liver fibrosis are reviewed in this article.