1.Establishing a finite element model of the mandible containing the temporomandibular joint after bilateral-sagitta-split-ramus-osteotomy with internal fixation
Wen MA ; Min HOU ; Dali SONG ; Jingwen YANG ; Zhi DAI ; Jialong CHENG ; Guoliang CHAI ; Weiyuan ZHOU ; Ruize ZHANG
Chinese Journal of Tissue Engineering Research 2015;(42):6730-6734
BACKGROUND:Bilateral-sagitta-split-ramus-osteotomy (BSSRO) has become a conventional method to correct facial deformities, and the finite element method is a significant way to study biomechanics of the mandible and temporomandibular joint (TMJ) after BSSRO. OBJECTIVE: To establish a precise and high simulation model of mandible containing TMJ after BSSRO with internal fixation, which is the base to study the biomechanics of the mandible and TMJ after BSSRO. METHODS: Spiral CT scan was used to get the data of DICOM that were input into MIMICS to establish the three-dimensional model of the mandible. The three-dimensional model was wrapped into a single closed shel for mesh generation and conversion in ANSYS. Then, the model was input into the ANSYS software for temporomandibular joint reconstruction and simulation of BSSRO and internal fixation. RESULTS AND CONCLUSION: The three-dimensional finite element model of mandible containing TMJ after BSSRO was established using MIMICS and ANSYS. This model had biological similarity and geometric similarity in comparison with the human tissues. The model could undergo various internal fixations through antedisplacement, retroposition and rotational movement of the distal end. Based on different experimental purposes, the established model can apply a load to al parts to study changes in stress and displacement of different tissues after BSSRO and internal fixation, and it also can be used to study the effect of different fixation materials on the rear stability after internal fixation.
2.Electro-clinical aspects of epilepsy with eye closure sensitivity
Chenxi SHEN ; Ruize MA ; Beibei CHEN ; Wenjuan ZHANG ; Xiaoli WANG ; Yonghong LIU
Chinese Journal of Neurology 2019;52(4):321-326
Objective To investigate the electro-clinical features of epilepsy with eye closure sensitivity (ECS).Methods The electroencephalograph database was searched using ECS during half a year period from January to June 2017 in Xijing Hospital.The duration of the follow-up was one year.Results Fifty-one patients diagnosed as epilepsy with ECS were investigated.Patients were classified into four epilepsy syndromes:33 with eyelid myoclonia with absences (EMA);13 with juvenile myoclonia epilepsy (JME);two with epilepsy with generalized tonic-clonic seizure on awakening and three with idiopathic occipital lobe epilepsy (IOE).The duration of the epileptiform discharges (EDs) triggered by eye closure (ECL) lasted more than five seconds in four patients with EMA and one patient with IOE.The EDs triggered by ECL were more frequent (85.2± 11.4 vs 37.5± 12.6,t=12.399,P=0.000) and lasting longer ((4.3± 1.9) s vs (2.3±0.8) s,t=3.585,P=0.001) in EMA than in JME.Conclusions ECS is common in EMA.The frequency and duration of the EDs triggered by ECL are helpful for identifying EMA and JME.
3.Parkin promotes proteasomal degradation of p62: implication of selective vulnerability of neuronal cells in the pathogenesis of Parkinson's disease.
Pingping SONG ; Shanshan LI ; Hao WU ; Ruize GAO ; Guanhua RAO ; Dongmei WANG ; Ziheng CHEN ; Biao MA ; Hongxia WANG ; Nan SUI ; Haiteng DENG ; Zhuohua ZHANG ; Tieshan TANG ; Zheng TAN ; Zehan HAN ; Tieyuan LU ; Yushan ZHU ; Quan CHEN
Protein & Cell 2016;7(2):114-129
Mutations or inactivation of parkin, an E3 ubiquitin ligase, are associated with familial form or sporadic Parkinson's disease (PD), respectively, which manifested with the selective vulnerability of neuronal cells in substantia nigra (SN) and striatum (STR) regions. However, the underlying molecular mechanism linking parkin with the etiology of PD remains elusive. Here we report that p62, a critical regulator for protein quality control, inclusion body formation, selective autophagy and diverse signaling pathways, is a new substrate of parkin. P62 levels were increased in the SN and STR regions, but not in other brain regions in parkin knockout mice. Parkin directly interacts with and ubiquitinates p62 at the K13 to promote proteasomal degradation of p62 even in the absence of ATG5. Pathogenic mutations, knockdown of parkin or mutation of p62 at K13 prevented the degradation of p62. We further showed that parkin deficiency mice have pronounced loss of tyrosine hydroxylase positive neurons and have worse performance in motor test when treated with 6-hydroxydopamine hydrochloride in aged mice. These results suggest that, in addition to their critical role in regulating autophagy, p62 are subjected to parkin mediated proteasomal degradation and implicate that the dysregulation of parkin/p62 axis may involve in the selective vulnerability of neuronal cells during the onset of PD pathogenesis.
Adaptor Proteins, Signal Transducing
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chemistry
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metabolism
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Animals
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HEK293 Cells
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Heat-Shock Proteins
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chemistry
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metabolism
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Humans
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Lysine
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metabolism
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Mice
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Neurons
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metabolism
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pathology
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Oxidopamine
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pharmacology
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Parkinson Disease
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metabolism
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pathology
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Proteasome Endopeptidase Complex
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metabolism
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Protein Stability
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Proteolysis
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drug effects
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Sequestosome-1 Protein
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Ubiquitin-Protein Ligases
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metabolism
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Ubiquitination
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drug effects