1.Primary leiomyosarcoma of bone: imaging findings
Danjun XU ; Jiawei WANG ; Leiming XU
Chinese Journal of Radiology 2019;53(8):715-719
Objective To analyze the radiological imagines and SPECT imaging features of primary leiomyosarcoma of bone and to improve the diagnostic level. Methods The imaging data of 16 patients in our hospital from January 2009 to May 2018 were retrospectively analyzed by two senior musculoskeletal radiologists, and they were all proved by surgery and pathology. The location of the lesions, type of bone destruction, size, soft tissue mass, mineralization, pathological fracture and periosteal reaction were detected by radiography and CT. The types of bone destruction are osteolytic, cystic and mixed. Periosteal reaction was divided into codman triangle, layered periosteal reaction and spiculate periosteal reaction. The signal intensity of lesions, size, distruction of the bony cortex, soft tissue mass and peritumoral edema were detected by MRI.Signal intensity was divided into low signal,iso?signal and high signal by taking surrounding normal muscles as reference. Enhancement scan was used to detect the form of enhancement. SPECT bone scan: compared with normal bone, SPECT bone scan signals were higher than normal bone, which was called concentrated radioactivity. Results Among the 16 cases, located in tibia(5 cases), femur (4 cases), sacrum(1 case), pubis(1 case), ilium(1 case), thoracic vertebra (2 cases) and humerus(2 cases). Radiography showed osteolytic, cystic and mixed bone destruction, among which 8 cases were osteolytic, 2 cases were cystic, 4 cases were mixed, and 1 case was normal. On CT images, 9 cases were osteolytic, 6 cases with soft tissue masses, among which 3 cases with partial sclerosis rim (2 cases with pathological fractare and obviously enhanced), 1 case with mild bone expansion and soft tissue, 2 cases with partial sclerosis rim. Four cases were mixed, all with cortical bone destruction, penetration, 1 case with soft tissue mass and periosteal reaction, 1 case which in the long bone of the extremity was central in location with periosteal reaction. Two cases were obviously and heterogeneously enhanced atter the enhanced CT scanning (1 case with bone expansion). Two cases were cystic,all with cortical destruction and penetration,1 case with soft tissue mass,1 case with partial sclerotic rim;after the enhanced CT scanning,2 case were obviously and heterogeneously enhanced. The most of the MR imagines showed the iso?intensity signal(10cases) and/or lightly lower signal(3cases), lightly higher sign(2cases) on T1WI, inhomogeneous hyperintensity on T2WI (15cases),after injected contrast medium,the tumor was inhomogeneous enhancement(14cases)with the cysts, necrosis and hemorrhage in it,11 cases with soft tissue masses,12 cases accompanied by peritumoral edema. On SPECT bone scan,10 Cases showed significant concentrated radioactivity(1 case was circumferential) and 1 case was mild concentrated radioactivity. Conclusion PLB usually occurs in the lower extremities,more frequently at the distal end of the femur, the proximal end of the tibia. The mainly appearance are central situated and osteolytic destruction with mass of the soft tissue. Although PLB has some imaging features, it is difficult to differentiate it from malignant bone tumors. Multi?imaging modalities such as radiography, CT, MRI and SPECT may suggest the diagnosis.
2.Develop a 3D neurological disease model of human cortical glutamatergic neurons using micropillar-based scaffolds.
Cheng CHEN ; Xin DONG ; Kai-Heng FANG ; Fang YUAN ; Yao HU ; Min XU ; Yu HUANG ; Xixiang ZHANG ; Danjun FANG ; Yan LIU
Acta Pharmaceutica Sinica B 2019;9(3):557-564
Establishing an effective three-dimensional (3D) culture system to better model human neurological diseases is desirable, since the human brain is a 3D structure. Here, we demonstrated the development of a polydimethylsiloxane (PDMS) pillar-based 3D scaffold that mimicked the 3D microenvironment of the brain. We utilized this scaffold for the growth of human cortical glutamatergic neurons that were differentiated from human pluripotent stem cells. In comparison with the 2D culture, we demonstrated that the developed 3D culture promoted the maturation of human cortical glutamatergic neurons by showing significantly more MAP2 and less Ki67 expression. Based on this 3D culture system, we further developed an disease-like model of traumatic brain injury (TBI), which showed a robust increase of glutamate-release from the neurons, in response to mechanical impacts, recapitulating the critical pathology of TBI. The increased glutamate-release from our 3D culture model was attenuated by the treatment of neural protective drugs, memantine or nimodipine. The established 3D human neural culture system and TBI-like model may be used to facilitate mechanistic studies and drug screening for neurotrauma or other neurological diseases.