Objective To observe the change of collagen in osteoarthritis and study the pathogenesis of osteoarthritis.Methods The right hind limb of twenty-four adult New Zealand White rabbits were immobilized with plaster cast in extension position for 10,20,30 and 40 days,respectively.Six animals without immobilization served as control.The articular cartilage of the medial femur condyle was harvested for transmission electron microscopy,in-situ hybridization of collagenⅡ,and immunohistochemistry of collagenⅠ,Ⅱ,Ⅲ.Results Transmission electron microscopy showed articular cartilage was destructed from the fine collagen fiber network of tangential zone.The fine collagen fiber network did not contain chondrocyte.Immunohistochemistry and in-situ hybridization showed that in earlier period of osteoarthritis,the collagen typeⅡand its gene expression firstly increased,then decreased with destruction of ultrastructure,and chondrocytes enhanced type Ⅱ collagen expressing and synthesizing mainly in transition zone and upper deep zone.In articular cartilage of osteoarthritis there was type Ⅲ collagen,instead of typeⅠcollagen.Conclusion In osteoarthritis,articular cartilage degenerated from tangential layer,in which collagen can not be repaired after destruction,this may contribute to the chondral degeneration.

Objective:To analyze the clinical characteristics of severe adenovirus pneumonia with bacterial infection in children, so as to provide clinical evidences for early diagnosis and reliable treatment.Methods:A total of 72 pediatric cases with severe adenovirus pneumonia admitted to Pediatric Intensive Care Unit at the First People′s Hospital of Chenzhou from January 2018 to August 2019 were included.The clinical features, laboratory and imaging data, efficacy of the treatments and prognosis were investigated retrospectively.Patients were divided into with bacterial infection group and without bacterial infection group.The clinical characteristics were analyzed.Results:Among the 72 children, there were 54 males and 18 females, aging from 3 months to 5 years, including 37cases with bacterial infection and 35 cases without bacterial infection.Compared with the group without bacterial infection, the group with bacterial infection had longer heat duration and hospital stay [12.0 (10.0, 18.5) days vs.10.0 (9.0, 12.0) days; 6.0(4.0, 7.0) days vs.11.0(6.5, 16.0) days, P<0.05], the incidences of diarrhea and hepatomegaly were higher[35.1% (13/37) vs.14.3%(5/35); 45.9%(17/37)vs.8.6%(3/35), P<0.05], the proportion of five lobes involved in lung imaging was higher [91.8% (34/37) vs. 57.1%(20/35), P<0.05]. The incidences of complications with respiratory failure, hemophagocytic lymphohistiocytosis, and bronchiolitis obliterans in the group with bacterial infection were significantly higher than those of without bacterial infection group ( P<0.05). Conclusion:For children under 2 years old age with severe adenovirus pneumonia, there are prolonged high fever and extensive pulmonary lesions.We should be highly alert to the combination of bacterial infection and timely anti-infection therapy.Children with severe adenovirus pneumonia with bacterial infection have severe clinical manifestations and many complications with respiratory failure, hemophagocytic lymphohistiocytosis, and bronchiolitis obliterans.

BACKGROUND:Metal-organic frameworks exhibited great potential for bone tissue engineering and bone disease treatment because of its unique merits including tunable porosity,a large specific surface area,good biocompatibility,and easy structure modification. OBJECTIVE:To review the advancements,application,strengths,and weaknesses of metal-organic framework materials in bone repair,arthritis,bone infection,and bone tumors,offering guidance and strategies for future research. METHODS:Web of Science,PubMed,and CNKI databases were searched using Chinese and English keywords"metal-organic frameworks,MOFs,orthopedics,bone repair,bone regeneration,orthopaedic applications,bone tissue engineering,bone infection,arthritis,bone tumor,osteosarcoma"for related literature published from 2015 to 2023.Following initial screening based on inclusion and exclusion criteria,72 articles were finally included for review. RESULTS AND CONCLUSION:(1)During bone repair,metal ions of metal-organic frameworks can induce bone formation by activating specific signaling pathways,which include stimulating osteogenic gene expression,inhibiting osteoclasts,encouraging blood vessel formation,and speeding up bone mineralization.Hence,metal-organic frameworks with metals like calcium,strontium,cobalt,copper,and magnesium ions show significant potential in enhancing bone implant performance.(2)Metal-organic framework materials,especially zinc/cobalt-based metal-organic frameworks,exhibit enzyme-like activities and promote cartilage regeneration by scavenging reactive oxygen species.Compared with natural enzymes,it has the advantages of not easy inactivation and better stability.(3)Zinc-based metal-organic framework materials characterized with wide band gaps,efficient separation and migration of photogenerated carriers,and high stability,the enhancement of photocatalytic activity results from enhancing the excited electron-hole widely used for the eradication of bacteria and tumor cells.(4)Bimetallic metal-organic frameworks,the doping of additional metals,showed critical advantages in optimizing structural performance,such as zinc/magnesium-based metal-organic framework 74 offering increased stability for durable antibacterial activity,and the light absorption capacity and photocatalytic efficiency of tantalum/zirconium-based metal-organic framework greatly improved and thus enhancing the radiation therapy.(5)However,metal-organic framework materials still face challenges in clinical applications,such as the uncertainty of drug release,in vivo safety,and potential immune responses from long-term presence.