Objective:To explore the differences in intravascular ultrasound results in elderly coronary heart disease(CHD)patients with different uric acid levels.Methods:A total of 145 elderly patients diagnosed with CHD in our hospital from December 2017 to May 2020 were included as study subjects.Uric acid levels were measured and intravascular ultrasound examination was conducted in all patients.They were divided into different groups based on uric acid levels: Group A(uric acid≤199 μmol/L), Group B(uric acid 200~399 μmol/L)and Group C(uric acid≥400 μmol/L). Data from intravascular ultrasound-derived indexes were analyzed and compared between the three groups.Results:There was no significant difference in the degree of left main stenosis between Group A and Group B, but it was less severe in both groups than in Group C( F=5.625, P=0.039). Plaque fibrous cap thickness showed no significant difference between Group B and Group C, but it was smaller than in Group A( F=7.825, P=0.020). Group C had the largest plaque area and maximum thickness among the three groups, followed by Group B[(11.12±1.73)mm 2 and(1.76±0.24)mm]and Group A[(8.29±3.14)mm 2 and(1.38±0.09)mm]( F=6.384 and 6.827, P=0.028 and 0.015). Conclusions:Elevated uric acid levels in elderly CHD patients can increase the area and thickness of plaques, and reduce plaque fibrous cap thickness, leading to an increased risk of formation of unstable plaques, which can be life-threatening for these patients.Thus, monitoring and managing uric acid levels should be stressed in elderly CHD patients.

BACKGROUND:Cartilage defects are one of the major clinical challenges faced by orthopedic surgeons.Tissue engineering is an interdisciplinary approach that combines knowledge of engineering and cell biology to provide new ideas and approaches for the repair of cartilage defects. OBJECTIVE:To prepare a multi-component composite scaffold based on silk fibroin,gelatin,and chitosan to screen for a three-dimensional porous scaffold suitable for cartilage regeneration by evaluating its physicochemical properties and biological performance. METHODS:Four groups of porous scaffolds were prepared by vacuum freeze-drying method using silk fibroin,gelatin and chitosan as the base materials,namely chitosan/gelatin scaffold,silk fibroin/chitosan scaffold,silk fibroin/gelatin scaffold and silk fibroin/chitosan/gelatin scaffold.The suitable cartilage scaffolds were screened by scanning electron microscopy,X-ray diffractometer,porosity,water absorption and swelling rate,biodegradation rate and mechanical property detection.Then cartilage scaffolds were co-cultured with chondrocytes isolated and extracted from patients with osteoarthritis.The feasibility of porous scaffolds for cartilage injury repair was evaluated in vitro by cell adhesion rate assay,cell live-dead staining and cell activity proliferation assay. RESULTS AND CONCLUSION:(1)All four groups of scaffolds had porous structures.The comprehensive physical performance test results showed that the silk fibroin/gelatin/chitosan scaffold was more in line with the requirements of cartilage defect repair.This scaffold had a pore size of(176.00±53.68)μm,the porosity of(80.15±2.57)%,and water absorption and swelling rate of(3 712±358)%.After immersion in PBS containing lysozyme for 28 days in vitro,the biodegradation rate was(46.87±3.25)%,and it had good mechanical properties.(2)Chondrocytes could adhere well on the silk fibroin/gelatin/chitosan scaffold,and the cell adhesion rate increased with time.CCK8 and live/dead cell double staining results showed that silk fibroin/gelatin/chitosan scaffold had good biocompatibility and low cytotoxicity.(3)The results showed that silk fibroin/gelatin/chitosan scaffold had a highly hydrated 3D structure,suitable pore size and porosity,good biodegradability and superior mechanical properties,which can provide a good reticular skeleton and microenvironment for nutrient transport and chondrocyte attachment and proliferation.