Objective To investigate the application value of 320-slice wide-detector multi-phase left at-rial appendage computed tomography angiography(LAA-CTA)with pulmonary artery(PA)monitoring in the preoperative evaluation of left atrial appendage closure.Methods A retrospective analysis was conducted on the clinical data of 110 patients who underwent LAA-CTA before left atrial appendage closure.Among them,47 patients underwent single-phase enhanced scanning with superior vena cava(SVC)monitoring(con-trol group),and 63 patients underwent multi-phase enhanced scanning with pulmonary artery monitoring(study group).The differences in imaging effects of the left atrial appendage under different monitoring points and phase imaging methods were compared,as well as the accuracy of comparing with the diagnostic results of transesophageal ultrasound(TEE),and the differences in the presentation of thrombus,perithrombus,and hypoperfusion areas in the left atrial appendage.Results The study group could comprehensively display the multi-phase CT value changes of different components(thrombus,peri-thrombotic viscosity,normal blood)within the left atrial appendage cavity,and its evaluation of lesion size and progression was superior to that of the control group.Using TEE as the gold standard,the study group demonstrated better diagnostic ac-curacy for different components and normal regions within the left atrial appendage cavity compared to the control group(P<0.001).Additionally,the study group improved the detection rate of peri-thrombotic vis-cosity,clearly delineated thrombus boundaries,and enhanced diagnostic accuracy(P<0.001).Conclusion Multi-phase LAA-CTA with pulmonary artery monitoring can effectively evaluate the morphological dimensions,thrombus,and peri-thrombotic CT manifestations of the left atrial appendage.It is simple to operate,with an accuracy rate close to the gold standard,providing reliable imaging evidence for preoperative evaluation of left atrial appendage closure.

Blood glucose fluctuation leads to poor bone defect repair in patients with type 2 diabetes (T2DM). Strategies to safely and efficiently improve the bone regeneration disorder caused by blood glucose fluctuation are still a challenge. Neutral sphingophospholipase 2 (Smpd3) is downregulated in jawbone-derived bone marrow mesenchymal stem cells (BMSCs) from T2DM patients. Here, we investigated the effect of Smpd3 on the osteogenic differentiation of BMSCs and utilized exosomes from stem cells overexpressing Smpd3 as the main treatment based on the glucose responsiveness of phenylboronic acid-based polyvinyl alcohol crosslinkers and the protease degradability of gelatin nanoparticles. The combined loading of Smpd3-overexpressing stem cell-derived exosomes (Exos-Smpd3) and nanosilver ions (Ns) to construct a hydrogel delivery system (Exos-Smpd3@Ns) promoted osteogenesis and differentiation of BMSCs in a glucose-fluctuating environment, ectopic osteogenesis of BMSCs in a glucose-fluctuating environment and jawbone regeneration of diabetic dogs in vitro. Mechanistically, Smpd3 promoted the osteogenesis and differentiation of jawbone-derived BMSCs by activating autophagy in the jawbone and inhibiting macrophage polarization and oxidative stress caused by blood glucose fluctuations. These results reveal the role and mechanism of Smpd3 and the Smpd3 overexpression exosome delivery system in promoting BMSC function and bone regeneration under blood glucose fluctuations, providing a theoretical basis and candidate methods for the treatment of bone defects in T2DM patients.
Exosomes ; Animals ; Bone Regeneration/drug effects* ; Dogs ; Mesenchymal Stem Cells ; Humans ; Blood Glucose ; Cell Differentiation ; Osteogenesis/drug effects* ; Diabetes Mellitus, Type 2/therapy* ; Diabetes Mellitus, Experimental ; Cells, Cultured ; Hydrogels ; Male