1.Repair of sciatic nerve defects with tissue engineered nerves constructed with marrow stromal cells
Hongyun HE ; Yihao DENG ; Xiaojie TONG ; Jiamao CHENG ; Zhaokang DU
Chinese Journal of Tissue Engineering Research 2009;13(28):5562-5566
BACKGROUND: Schwann calls are seed cells for constructing tissue engineered peripheral nerves. But their in vitro isolation, culture and purification are difficult. Acellular nerve allografts (ANA) have a great effect on repairing peripheral nerve defects, and it can induce marrow stromal cells (MSCs) into Schwann-like calls. Accordingly, MSCs can be used as seed calls theoretically in constructing tissue engineered peripheral nerves, instead of Schwann cells OBJECTIVE: To observe the repairing effect of tissue engineered peripheral nerves constructed with MSCs on sciatic nerve defects and to assess the feasibility of repairing peripheral nerve defects with MSCs as seed calls. DESIGN, TIME AND SE'I-rlNG: A randomized control animal experiment was conducted in the laboratory of Basic Medicine Collage of Dali Collage from July to December in 2008.MATERIALS: A total of 30 SD rats were divided randomly into 3 groups, with 10 in each group. In MSCs+ ANA group, end-to-end anastomosis were performed with 10/0 non traumatic suture to broken ends of rat sciatic nerves and tissue engineered nerves cultured using MSCs combined with ANA; In ANA group, ANA were bridged to broken ends of sciatic nerves; In METHODS: The 10ram sciatic nerve defects in rats were repaired using MSCs-constructed tissue engineered peripheral nerves, whose repairing effects were evaluated at week 12 post transplant through sciatic function index (SFI), gastrocnemius wet weight recovery rate, S-100 immunohistochemical staining and electron microscope observation, etc. MAIN OUTCOME MEASURES: Morphological changes of calls were observed during the culture of compounds; SFI and gastrocnemius wet weight recovery rates were detected after transplantation; New myelinization, axon growth and nerve fiber distdbuUon were observed with toluidine blue staining; Schwann calls growth and nerve fiber regeneration were observed with transmission electron microscope combined with S-100 protein immunohistochemical staining method.RESULTS: The detection results showed that SFI and gastrocnemius wet weight recovery rate were higher in the MSCs+ ANA group than in the ANA group (P < 0.05). Compared the ANA group, the MSCs+ ANA group had more S-100 proteins expressed in its compounds obviously, and the number, the diameter of its myelinated nerve fibers as well as its myelin sheath thickness were all greater than those of the ANA group (P < 0.05). The repairing effect of the MSCs+ ANA group was close to that of the autotransplantation group.CONCLUSION: MSCs-constructed tissue engineered nerves have a better effect on repairing peripheral nerve defects than ANA, and MSCs as seed cells have a high value in peripheral nerve tissue engineering.
2.Analysis of Correlation between Surface Electromyography and Spasticity after Stroke.
Ping XIE ; Yan SONG ; Chongqin SU ; Wenyu XU ; Yihao DU
Journal of Biomedical Engineering 2015;32(4):795-801
To quantitatively evaluate the upper-limb spasticity of stroke patients in recovery stage, the relationship between surface electromyography (sEMG) characteristic indexes from biceps brachii and triceps brachii and the spasticity were explored, which provides the electrophysiological basis for clinical rehabilitation. Ten patients with spasticity after stroke were selected to be estimated by modified Ashworth (MAS) assessment and a passive elbow sinusoidal motion experiment was carried out. At the same time, the sEMG of biceps and triceps were recorded. The results shows that the reflex electromyographic threshold could reflect the physiological mechanism of spasticity and had significant correlation with MAS scale which showed that sEMG could be prosperous for the clinical quantitative evaluation of spasticity of stroke patients.
Electromyography
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Humans
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Muscle Spasticity
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physiopathology
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Muscle, Skeletal
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physiopathology
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Stroke
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physiopathology
3.Differentiation of rat bone marrow stromal stem cells into neuron-like cells induced by breviscapine
Hongyun HE ; Yihao DENG ; Bensi ZHANG ; Zhaokang DU
Acta Anatomica Sinica 2010;41(1):70-74
Objective To explore the feasibility of differentiation into neural cells from bone marrow stromal cells(BMSCs) in vitro by breviscapine,and to offer reference for the applying of BMSCs. Methods The bone marrow stromal cells of SD rat were separated and purified by passsage culture.After phenotype characterization,the 4th passage of BMSCs was exposed to breviscapine. Differentiation was observed under phase contrast microscope every 6 hours and the cells were stained immunocytochemically with neuronspecific enolase(NSE)and glial fibrillary acidic protein(GFAP).The induced cells activity was detected by MTT. NSE and GFAP were determined by flow cytometry and RT-PCR. Results The BMSCs were CD44~+,CD54~+,CD34~-. After 18 hours of induction, cytoplasm of BMSCs partly contracted with protruding;The immunocytochemical staining was performed on cells after induction for 24 hours,the rates of NSE and GFAP staining positive were(48.7±3.4)% and(56.8±4.2)%.By using flow cytometer, expressions of NSE and GFAP showed much higher in induced group than that in control group. By using RT-PCR, expressions of NSE and GFAP were positive in induced group. Conclusion Breviscapine could induce adult rat BMSCs to differentiate into neuron and glial cells.
4.Analysis of corticomuscular coherence during rehabilitation exercises after stroke.
Peipei MA ; Yingya CHEN ; Yihao DU ; Yuping SU ; Xiaoguang WU ; Zhenhu LIANG ; Ping XIE
Journal of Biomedical Engineering 2014;31(5):971-977
To better evaluate neuromuscular function of patients with stroke related motor dysfunction, we proposed an effective corticomuscular coherence analysis and coherent significant judgment method. Firstly, the related functional frequency bands in the electroencephalogram (EEG) were extracted via wavelet decomposition. Secondly, coherence were analysed between surface electromyography (sEMG) and sub-bands extracted from EEG. Further more, a coherent significant indicator was defined to quantitatively describe the similarity in certain frequency domain and phase lock activity between EEG and sEMG. Through the analysis of corticomuscular coherence during knee flexion-extension of stroke patients and healthy controls, we found that the stroke patients exhibited significantly lower gamma-band corticomuscular coherence in performing the task with their affected leg, and there was no statistically significant difference between their unaffected lag and the healthy controls, but with the rehabilitation training, the bilateral difference of corticomuscular coherence in patients decreased gradually.
Case-Control Studies
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Electroencephalography
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Electromyography
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Exercise Therapy
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Humans
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Knee
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physiology
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Muscle, Skeletal
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physiology
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Range of Motion, Articular
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Stroke Rehabilitation
5.Relationship between YES-related protein 1 and prostate-specific antigen in castration-resistant prostate cancer
Miaomiao WANG ; Peikang WU ; Yihao LIAO ; Mingyang DU ; Yuanjie NIU ; Ning JIANG
Chinese Journal of Geriatrics 2020;39(2):192-196
Objective:To investigate the relationship between YES-related protein 1(YAP1)and prostate-specific antigen(PSA)in human castration-resistant prostate cancer(CRPC), and explore the regulation mechanism of YAP1 on PSA.Methods:The luciferase reporter gene was used to detect the activity change of the PSA gene promoter region after the over expression of YAP1 in LNCaP and C4-2 cells.The effect of over expression of YAP1 gene on PSA protein in different prostate cancer cell lines was detected by Western blot(WB)method, and the effect of YAP1 silencing on PSA protein in C4-2 cells was observed.The Q-PCR method was used to further verify the expression change of PSA mRNA affected by YAP1 gene over expressed in C4-2 cells.Meanwhile, WB was used to explore the effect of YAP1 on androgen receptor(AR)in C4-2 cells.Results:After over expression YAP1 in CRPC, the luciferase experiment showed that the average C4-2 cell ratio of experimental group to control group was 3.17815892(>2 times, P<0.001). After Q-PCR detection of all over-expressed YAP1 gene fragments, the measured PSA mRNA values in the experimental groups were 2.306667, 1.553333333, 2.613333333, and 2.673333333, respectively, which were higher than those in the control group(1 time, P<0.001), indicating that the PSA expression was significantly increased.WB analysis showed that after C4-2 cells over expressed YAP1, the AR band was significantly enhanced in the experimental group compared with the control group, suggesting that the AR protein expression in the nucleus was significantly increased in the YAP1 over expression group. Conclusions:YAP1 might positively regulate the PSA expression in CRPC and have an ability to promote AR translocation into the nucleus.
6.Intermuscular coupling based on wavelet packet-cross frequency coherence.
Yihao DU ; Xiaolin BAI ; Wenjuan YANG ; Lin ZHENG ; Ping XIE
Journal of Biomedical Engineering 2020;37(2):288-295
Human motion control system has a high degree of nonlinear characteristics. Through quantitative evaluation of the nonlinear coupling strength between surface electromyogram (sEMG) signals, we can get the functional state of the muscles related to the movement, and then explore the mechanism of human motion control. In this paper, wavelet packet decomposition and : coherence analysis are combined to construct an intermuscular cross-frequency coupling analysis model based on wavelet packet- : coherence. In the elbow flexion and extension state with 30% maximum voluntary contraction force (MVC), sEMG signals of 20 healthy adults were collected. Firstly, the subband components were obtained based on wavelet packet decomposition, and then the : coherence of subband signals was calculated to analyze the coupling characteristics between muscles. The results show that the linear coupling strength (frequency ratio 1:1) of the cooperative and antagonistic pairs is higher than that of the nonlinear coupling (frequency ratio 1:2, 2:1 and 1:3, 3:1) under the elbow flexion motion of 30% MVC; the coupling strength decreases with the increase of frequency ratio for the intermuscular nonlinear coupling, and there is no significant difference between the frequency ratio : and : . The intermuscular coupling in beta and gamma bands is mainly reflected in the linear coupling (1:1), nonlinear coupling of low frequency ratio (1:2, 2:1) between synergetic pair and the linear coupling between antagonistic pairs. The results show that the wavelet packet- : coherence method can qualitatively describe the nonlinear coupling strength between muscles, which provides a theoretical reference for further revealing the mechanism of human motion control and the rehabilitation evaluation of patients with motor dysfunction.
Adult
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Algorithms
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Electromyography
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Humans
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Movement
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Muscle Contraction
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Muscle, Skeletal
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physiology
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Range of Motion, Articular
7.Analysis of multichannel intermuscular coupling characteristics during rehabilitation after stroke.
Yihao DU ; Wenjuan YANG ; Wenxuan YAO ; Wenjing QI ; Xiaoling CHEN ; Boduo XIE ; Ping XIE
Journal of Biomedical Engineering 2019;36(5):720-727
To better analyze the problem of abnormal neuromuscular coupling related to motor dysfunction for stroke patients, the functional coupling of the multichannel electromyography (EMG) were studied and the difference between stroke patients and healthy subjects were further analyzed to explore the pathological mechanism of motor dysfunction after stroke. Firstly, the cross-frequency coherence (CFC) analysis and non-negative matrix factorization (NMF) were combined to construct a CFC-NMF model to study the linear coupling relationship in bands and the nonlinear coupling characteristics in different frequency ratios during elbow flexion and extension movement. Furthermore, the significant coherent area and sum of cross-frequency coherence were respectively calculated to quantitatively describe the intermuscular linear and nonlinear coupling characteristics. The results showed that the linear coupling relationship between multichannel muscles was different in frequency bands and the overall coupling was stronger in low frequency band. The linear coupling strength of the stroke patients was lower than that of the healthy subjects in different frequency bands especially in beta and gamma bands. For the nonlinear coupling, the intermuscular coupling strength of stroke patients in different frequency ratios was significantly lower than that of the healthy subjects, and the coupling strength in the frequency ratio 1∶2 was higher than that in the frequency ratio 1∶3. This method can provide a theoretical basis for exploring the intermuscular coupling mechanism of patients with motor dysfunction.
Case-Control Studies
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Electromyography
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Humans
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Muscle, Skeletal
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physiopathology
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Stroke
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physiopathology
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Stroke Rehabilitation