To summarize Notch, basic hel ix-loop-hel ix (bHLH) and Wnt gene signal transduction pathways in the process of differentiation and development of neural stem cells. Methods The l iterature on the gene signal transduction pathway in the process of differentiation and development of neural stem cells was searched and then summarized and analyzed. Results The formation of Nervous System resulted from common actions of multi-signal transduction pathways. There may exist a fixed threshold in the compl icated selective system among Notch, bHLH and Wnt gene signal transduction pathways. Conclusion At present, the specific gene signal transduction pathway of multi pl ication and differentiation of neural stem cells is still unclear.
Objective To review the progress and application of peripheral nervous microelectrode. Methods The recent articles on peripheral nervous microelectrode were extensively reviewed. The classification, the progress of the peripheral nervous microelectrode and its utilizable prospect in the control of electronic prosthesis were summarized. Results The microelectrodes had favorable functions of selective stimulation and recording. It provided an information transmitting interface between the electric prosthesis and peripheral nerves. Conclusion Peripheral nervous signal is a feasible signal source to control electronic prosthesis.
ObjectiveTo investigate the effects of signaling pathway about the EGFR, MAPK, IKB/NF-κB, PI3K/Akt, WNT/beta-catenin, and the Hedgehog in development of hepatocellular carcinoma(HCC). MethodsThe related literatures about the molecular genetic mechanism of signaling pathways were reviewed. ResultsIn the occurrence and development of HCC, the EGFR, MAPK, IKB/NF-κB, PI3K/Akt, WNT/β-catenin, and Hedgehog signaling pathways not only interweaver with each other complexly, but also interact with each other, and some tumor markers, anticancer genes, proto-oncogenes, and miRNA may have synergistic effects for the occurrence of HCC. ConclusionThe abnormal changes of molecular signaling pathways is a necessary condition for the occurrence and development of tumor, and there is considerable cross-talk and redundancy to many signaling pathways.
As one of the standard electrophysiological signals in the human body, the photoplethysmography contains detailed information about the blood microcirculation and has been commonly used in various medical scenarios, where the accurate detection of the pulse waveform and quantification of its morphological characteristics are essential steps. In this paper, a modular pulse wave preprocessing and analysis system is developed based on the principles of design patterns. The system designs each part of the preprocessing and analysis process as independent functional modules to be compatible and reusable. In addition, the detection process of the pulse waveform is improved, and a new waveform detection algorithm composed of screening-checking-deciding is proposed. It is verified that the algorithm has a practical design for each module, high accuracy of waveform recognition and high anti-interference capability. The modular pulse wave preprocessing and analysis software system developed in this paper can meet the individual preprocessing requirements for various pulse wave application studies under different platforms. The proposed novel algorithm with high accuracy also provides a new idea for the pulse wave analysis process.
ObjectiveTo explore if Smad7 protein can inhibit growth of keloids by observing the gene and protein expressions of Smad7, collagen type Ⅰ, and collagen type Ⅲ and cell proliferation after over-expression vectors of Smad7 transfecting keloid fibroblasts (KFb). MethodsFibroblasts were acquired from 10 male patient with keloids at the age of 20 to 25 years. After in vitro culture, KFb were divided into 3 groups: untransfected group (group A), pcDNA3.1 (-) transfected group (group B), and pcDNA3.1 (-)-smad7 transfected group (group C). The mRNA and protein expression levels of Smad7, collagen type Ⅰ, and collagen type Ⅲ were detected by real-time fluorescence quantitative PCR and Western blot at 48 hours after transfection. The cell proliferation ability was detected by MTT assay at 24 hours after transfection. ResultsThe relative expression levels of mRNA and protein of Smad7 in group C were significantly higher than those in group A and group B (P < 0.01). The relative expression levels of mRNA and protein of collagen type Ⅰ and collagen type Ⅲ in group C were significantly lower than those in group A and group B (P < 0.01). The relative expression levels of mRNA of collagen type Ⅰ and collagen type Ⅲ in group B were significantly higher than those in group A (P < 0.01); and the relative expression levels of proteins of Smad7, collagen type Ⅰ, and collagen type Ⅲ were significantly lower than those in group A (P < 0.01). The cell proliferation ability in group C was significantly lower than that in group A and group B at each time point by MTT assay (P < 0.05), but no difference was found between group A and group B (P>0.05). ConclusionGene expressions of collagen type Ⅰ, and collagen type Ⅲ and cell proliferation will be inhibited after KFb are transfected by over-expression vector of Smad7.
The brain-computer interface (BCI) based on motor imagery electroencephalography (EEG) shows great potential in neurorehabilitation due to its non-invasive nature and ease of use. However, motor imagery EEG signals have low signal-to-noise ratios and spatiotemporal resolutions, leading to low decoding recognition rates with traditional neural networks. To address this, this paper proposed a three-dimensional (3D) convolutional neural network (CNN) method that learns spatial-frequency feature maps, using Welch method to calculate the power spectrum of EEG frequency bands, converted time-series EEG into a brain topographical map with spatial-frequency information. A 3D network with one-dimensional and two-dimensional convolutional layers was designed to effectively learn these features. Comparative experiments demonstrated that the average decoding recognition rate reached 86.89%, outperforming traditional methods and validating the effectiveness of this approach in motor imagery EEG decoding.
【Abstract】Objective To investigate the apoptosis induced by TGF-β1 in human hepatic carcinoma cell lines and its relationship with p53 gene and Smad. Methods Three human hepatic carcinoma cell lines which involving in various status of the p53 gene were used in this study. TGF-β1-induced apoptosis in hepatic carcinoma cell lines was measured by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. To study the mechanism of TGF-β1-induced apoptosis, these cell lines were transfected with a TGF-β1-inducible luciferase reporter plasmid containing Smad 4 binding elements (SBE) and luciferase gene using Lipofectamine 2000, then treated with TGF-β1, relative luciferase activity was assayed. Results Of three cell lines studied with TUNEL assay, TGF-β1 induced apoptosis was observed in HepG2 cells (wild type p53). Huh-7 (mutant p53) and Hep3B (deleted p53) cell lines showed less apoptosis. Luciferase activity assay indicated that the response to TGF-β1 induction in HepG2 cells was increased dramatically but was not significant in Huh-7 and Hep3B cell lines. Conclusion HepG2 cells seem to be highly susceptible to TGF-β1-induced apoptosis compared with Hep3B and Huh7 cell lines. Smad 4 is a central mediator of the TGF-β1 signal transduction pathway.
Objective To evaluate the effect of integrin-linked kinase (ILK) in the process of retinal neovascularization induced by vascular endothelial growth factor (VEGF). Methods The ILK activities of retinal choriodal endothelial cell line RF/6A were inhibited by LY294002 or siRNA knockdown. VEGF-induced changes of cell adhesion, proliferation, migration and endothelial cell tube-formation were measured then. The in-vivo effects of ILK were also assessed by intraperitoneal injection of LY294002 into an animal model of RNV. Results The cell adhesion measurements of control group, VEGF group, VEGF＋LY294002 group and VEGF＋siRNA group were 0.0726plusmn;0.01961, 0.1137plusmn;0.02631, 0.0837plusmn;0.01503 and 0.0853plusmn;0.02454 , respectively. The difference was statistically significant between VEGF group and control group（t =4.211，Plt;0.01）, and between (VEGF＋LY294002) group or (VEGF＋siRNA) group and control group (t =3.074, 2.91，Plt;0.01). The cell proliferation results of control group, VEGF group and VEGF＋LY294002 group were 0.4162plusmn;0.1392, 0.6412plusmn;0.2420, 0.4476plusmn;0.1834 , respectively. The difference was statistically significant between VEGF group and control group（t=2.608，Plt;0.05）, and between (VEGF＋LY294002) group and VEGF group（t=2.244，Plt;0.05）.The cell migration results of control group, VEGF group and VEGF＋LY294002 group were 83.66plusmn;30.283, 248plusmn;74.748, 138.5plusmn;38.167, respectively. The difference was statistically significant between VEGF group and control group（t=5.436，Plt;0.01）, and between (VEGF＋LY294002) group and VEGF group（t=3.682，Plt;0.01）. There was no obvious tube-formation after ILK activity was inhibited or knocked down. The non-perfusion areas were increased from （62798plusmn;16995.62）mu;m2 to （84722.65plusmn;10435.01）mu;m2 after intraperitoneal injection of LY294002 into animal model of RNV, the difference was statistically significant（t=3.476，Plt;0.01）. Conclusions ILK may play an important role in the process of VEGF-induced retinal neovascularization by regulating the cellular adhesion, proliferation, migration and tube-formation, as all those cellular functions were supressed obviously after the ILK activity was inhibited by LY294002 or the ILK expression was knocked down by siRNA.
Endometriosis (EM) is a common benign gynecological disease with complex pathogenesis and lack of unified understanding. In recent years, the theory of stem/progenitor cells has gradually been recognized by scholars. The presence of stem/progenitor cells in the endometrium and researchers’ understanding of stem/progenitor cell specific markers has been further developed, which is of great significance for sorting stem/progenitor cells and further elucidating their roles in the pathogenesis of EM. At present, more endometrial stem cell signaling pathways have been studied including Wnt, Hedgehog, Notch, phosphatidylinositol-3-kinase/protein kinase B, Smad/connective tissue growth factor, CXCL12/CXCR4, etc. These signaling pathways can regulate stem cell involvement in the pathogenesis of EM. Exploring how signaling pathways to regulate stem cell involvement in the pathogenesis of EM can help elucidate the specific pathogenesis of EM and provide new directions for its treatment. This paper will summarize them.
ObjectiveTo investigate influence factor of long-term survival of primary colorectal signet-ring cell carcinoma. MethodThe clinical data of 37 patients with primary colorectal signet-ring cell carcinoma from January 1990 to November 2010 in this hospital were analyzed retrospectively. ResultsThe cumulative survival rates of 1-, 2-, 3and 5-year after the initial surgery were 70.3%, 51.4%, 27.0%, and 10.8% respectively. The survival time of 37 patients was 26 months. The results of univariate analysis showed that the TNM stage, T stage, preoperative intestinal obstruction or not, operation mode, and postoperative chemotherapy or not were associated with the survival time of primary colorectal signet-ring cell carcinoma (P < 0.05). The results of multivariable analysis showed that TNM stage, T stage, and preoperative intestinal obstruction or not were the independent factors for the prognosis of patients with primary colorectal signetring cell carcinoma. ConclusionsThe survival rate of patients with primary colorectal signet-ring cell carcinoma is lower. TNM stage, T stage, and preoperative intestinal obstruction or not are independent factors of it. Chemotherapy after operation could prolong survival time of patients with primary colorectal signet-ring cell carcinoma.