Bone defects caused by factors such as developmental malformations, trauma, infection, tumor resection and failed joint replacement surgeries, represent a major challenge in clinical treatment. These defects lead to the loss of bone tissue or structural integrity and can result in various complications, causing multiple adverse effects on patients. Additionally, they often lead to psychological issues such as anxiety, significantly reducing quality of life. Recent studies have shown that mesenchymal stem cells (MSCs) exhibit great potential in the treatment of bone defects. These cells exert therapeutic effects through various mechanisms, including immune evasion, direct osteogenic differentiation, homing ability and paracrine activity, offering a promising new approach for bone defect treatment. Driven by the rapid development of novel biomaterials in recent years, a variety of innovative treatment strategies based on MSCs have emerged. MSC-based therapies for bone defects include standalone application, delivery via novel systems, combination with polymer scaffolds, genetic modification and preconditioning and cell-free therapies. This article reviews the fundamental characteristics of MSCs, their mechanisms of action in treating bone defects, current clinical research progress and the status of translational applications. Based on this, the prospects of MSC-based therapies are also discussed.

Objective:To provide guidance on parameters for future endovaginal coil magnetic resonance imaging(MRI)in vivo,and to investigate the imaging potential of the endovaginal coil technique.Methods:The endovaginal coil was used to perform T2-weighted turbo spin echo sequence imaging on a phantom containing three spatial resolution modules,with variations in key imaging parameters.Signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),and contrast(C)were calculated for images under different imaging parameters,and image quality was assessed based on scores within specified intervals.Structural display scores were determined for the three resolution modules of the phantom,and the non-parametric tests were used for statistical comparison between groups.Results:Under the main imaging parameters of a slice thickness of 2 mm,a slice gap of 0.2 mm,4 times of excitation repetition,a matrix size of 384×384,an FOV of 52 mm×52 mm,a TE of 74 ms,a bandwidth of 180 Hz/Pixel,and an acceleration factor of 18,good image quality was obtained with an acquired spatial resolution of 0.14 mm×0.14 mm×2.00 mm and a reconstructed resolution of 0.07 mm×0.07 mm×2.00 mm,and all three resolution modules were clearly visualized with a clinically acceptable imaging time.There were signifi-cant differences between groups in the imaging quality scores of slice thickness,slice gap,number of excitations,FOV,and accelera-tion factor(P<0.05),while there were no significant differences in matrix,TE,and bandwidth between groups(P=0.521,0.502,and 0.566).There were significant differences in the structural display scores for all parameters between groups(P<0.05).Conclusion:The parameters obtained in this experiment can guide the future ap-plication of endovaginal coils in the human body,demonstrating the extremely high imaging potential of this technique,and endovaginal coil has the potential of identifying small lesions in future clinical practice.

Objective    To explore the treatment outcome of carotid endarterectomy combined with vertebral artery transposition in patients with severe stenosis to occlusion of the vertebral artery V1 segment and the ipsilateral carotid artery. Methods    From June 2017 to September 2020, patients with severe stenosis to occlusion of the vertebral artery V1 segment and the ipsilateral carotid artery treated with carotid endarterectomy combined with vertebral artery transposition in Fuwai Hospital were retrospectively analyzed. Results    Finally 12 patients were enrolled, including 10 males and 2 females with an average age of 67.8±6.0 years. Twelve patients were successfully operated and the follow-up time was 1-3 years. The stenosis degree of the V1 segment of the vertebral artery decreased from 83.5%±11.8% to 24.9%±14.3% (P<0.001). The stenosis degree of carotid artery decreased from 85.6%±11.0% to 0% (P<0.001). Postoperative follow-up showed that the symptoms of symptomatic patients before surgery improved. The 1-year and 3-year patency rates were 100.0%, and there were no peripheral nerve injury complications, perioperative deaths or strokes. Conclusion    Carotid endarterectomy combined with vertebral artery transposition can treat ipsilateral carotid artery  stenosis and vertebral artery stenosis at the same time, improve blood supply to the brain, improve patients' symptoms and has high promotion value.

Objective    To investigate the treatment of modified vertebral-carotid transposition (VCT) in patients with severe stenosis or occlusion at V1 segment of vertebral artery. Methods    A retrospective study of 13 patients with severe stenosis or occlusion at V1 segment of vertebral artery treated by modified VCT in our hospital from October 2016 to December 2018 was done. There were 10 males and 3 females with an average age of 70.5±7.1 years. Results    The operation was successful in this series of patients. The follow-up duration was 1-3 years. The stenosis degree of the V1 segment of the vertebral artery decreased from 86.8%±7.5% to 17.4%±14.5%. All patients achieved remission of symptoms after the surgery. Temporary peripheral nerve injury occurred in 6 patients. Four patients with neurological complications relieved during follow-up. The patency rate was 100.0% at postoperative 1 and 3 years. There was no perioperative death, stroke or re-intervention. Conclusion    Modified VCT can precisely restore the distal blood flow of patients with severe stenosis or occlusion at V1 segment of vertebral artery, and relieve their symptoms.

Different microorganisms can cause intraperitoneal infection. This study was to distinguish different microbial infections by urine analysis. Rats were intraperitoneally injected with Escherichia coli, Staphylococcus aureus, and Candida albicans, separately. Urine samples were collected from rats at 0, 12, 36 and 72 h after infection. Urinary proteins were profiled using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Compared with the control (without infection), a total of 69 differential proteins were identified in rats injected with E. coli. A total of 31 differences proteins were identified in rats injected with S. aureus. A total of 38 differential proteins were identified in rats injected with C. albicans. Urine proteome was different when rats were infected by different microorganisms, suggesting that urine may have the potential for differential diagnosis of different intraperitoneal infections.
Animals ; Chromatography, Liquid ; Escherichia coli ; Proteome ; Rats ; Staphylococcus aureus ; Tandem Mass Spectrometry