1.Experimental study of cartilage defect repair using bone mesenchymal stem cells transfer of BMP-2 and TGF-β3 gene mediated by adenovirus vector combining with deminerized bone matrix in pig
Xin WANG ; Yanlin LI ; Yaofeng JIN ; Jianming CHEN ; Huijian WANG ; Chuan HE ; Shuhai CAO ; Fengkai ZHAO
The Journal of Practical Medicine 2014;(18):2880-2882
Objective To explore the repair result of full-thickness cartilage defects in diannan small-ear pig by bone mesenchymal stem cells (BMSCs) transferred with both transforming growth factor-β3(TGF-β3) and bone morphogenetic protein-2(BMP-2) gene mediated by adenovirus vector and combined with deminerized bone matrix (DBM). Methods 32 full-thickness defects from 16 knees of 8 pigs were randomly divided into 4 groups in the experiments. In group A, the animals′ lateral femoral condyle of right knee joint was repaired with DBM and BMSC infected with both Ad-TGF-β3 and Ad-BMP-2. In group B, the medial femoral condyle of right knee joint was repaired with DBM and BMSC without infection. In group C, the lateral femoral condyle of left knee joint was repaired with DBM. And the group D is control group. Morphology and histology were observed 2, 4, 8 and 12 weeks after operation. Results 12 weeks after operation, the whole defects were repaired in group A, HE staining showed typical cartilaginous structure in the repaired area. In group D, defects were not repaired but filled with fibrous tissue. The O′driscoll scores were 15.65 ± 0.11 (group A), 11.33 ± 0.22 (group B), 6.13 ± 0.15 (group C) and 5.08 ± 0.15 (group D). There was significant difference among the groups (P < 0.05). Conclusions The new type of tissue engineering scaffold that DBM combined with BMSCs transfected with both Ad-BMP-2 and Ad-TGF-β3 could induce cartilage regeneration and repair the defects.
2.Analysis and identification of electroencephalogram features in patients with Alzheimer’s disease and mild cognitive impairment
Huaying TAO ; Fengkai HE ; Xueyun DU ; Bingqian QU ; Huiyun YANG ; Aili LIU ; Tiaotiao LIU
International Journal of Biomedical Engineering 2024;47(4):325-334
Objective:To analyze the electroencephalogram (EEG) features of patients with Alzheimer’s disease (AD) and mild cognitive impairment (MCI), and to combine the characteristics for classification and prediction.Methods:One hundred and thirty-five patients attending the Department of Neurology at the General Hospital of Tianjin Medical University were enrolled, including 34 patients with AD, 67 patients with MCI, and 34 healthy control (HC). The electroencephalogram signals of these patients in the resting state were collected and preprocessed. Relative power spectral density features and sample entropy features on a multi-band scale were extracted to compare the whole-brain differences in electroencephalogram features among the 3 groups of subjects, and then subdivided into brain regions and individual leads for in-depth analysis. The above two features were fused to classify and predict AD, MCI, and HC by support vector machine (SVM).Results:The frontal regions had higher δ relative power spectral densities than the other regions, and the occipital and temporal regions showed relatively lower distributions. θ-Band relative power spectral densities had a more even distribution of sizes across brain regions. α-Band relative power spectral densities were concentrated in the occipital lobe, while β-band relative power spectral densities were mainly concentrated in the parietal and temporal lobes. Except for the central lobe, the δ-band relative power spectral densities of the AD group were higher than those of the MCI group ( P < 0.05) and HC group ( P < 0.01) in all brain regions and the whole brain. θ-band relative power spectral densities of the AD group were higher than those of the MCI gourp ( P < 0.001) and HC group ( P < 0.001) in the whole brain and in all brain regions. α-Band relative power spectral densities of the AD group were lower than those of the other groups only in the temporal lobe (all P < 0.05). The relative power spectral density of the β-band in the AD group was higher than that of the other groups in the whole brain and in all brain regions ( P < 0.05, 0.01, 0.001). The difference in the relative power spectral density of the δ-band in the C3 lead in the central lobe of the AD and HC groups was statistically significant ( P < 0.05). The relative power spectral density of the γ-band in the temporal lobe was higher than that in the other regions of the AD group, the MCI group, and the HC group. The relative power spectral density of the γ-band in the T3 lead in the AD group was significantly lower than that in the T4 lead. The average entropy of samples in the whole brain and in each brain region was lower than that in the HC group in the AD and MCI groups (all P < 0.05). The entropy of the samples at lead C3 in the AD group was lower than that in the MCI group ( P < 0.05). The differences between the relative power spectral density, sample entropy, and the actual data classification evaluation indexes (accuracy rate, precision rate, recall rate, and F1 score) that fused the two features, and the rearranged data were all statistically significant (all P < 0.001). When the relative power spectral density feature and the sample entropy feature were fused in the classification features, the best classification prediction was achieved, with an accuracy rate of 80%, a precision rate of 78%, a recall rate of 78%, and the F1 score of 79%. Conclusions:Relative power spectral density and sample entropy analysis can reveal the abnormalities of electroencephalogram activities of AD and MCI patients from different perspectives (linear and nonlinear), and the combination of these two features in classification prediction can improve the classification effect.