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Objective:To study a new type of impulse neuron model and its network, describe its modeling method, and verify its performance by computer simulation.Methods:Based on full consideration of biological adaptability (activation potential threshold and refractory period switch) and its dynamic regulation mechanism for the generation and transmission of spike discharge pulses, a post-potential multi-channel filter was introduced in the new impulse neuron model. The filter can realize the dynamic adjustment of output current and neuron synaptic strength. An error back-propagation (BP) learning algorithm based on adaptive least mean square (LMS) was proposed, and applied to the regulation of spike discharge neural networks.Results:Under spontaneous noise, the pulsation interval signal histogram of the new impulse neuron model satisfies Poisson distribution. Through the simple connection of two new pulsed neurons, a variety of complex spike discharge patterns can be formed. The new impulse neuron model has the characteristics of spontaneous intrinsic noise, can form complex periodic spike discharge patterns. For input noise control, the refractory period and threshold potential adaptability parameters of the new impulse neuron model has good stability. The linear relationship between the stimulation current and the frequency of the spike discharge pulse is good.Conclusions:The proposed new model can generate multiple modes of oscillation and coherent oscillation under the condition of spontaneous noise, which is very similar to biological neurons and can realize complex noise processing. The multi-channel post-synaptic potential filters with different frequency bands can make some post-synaptic potential signals become smooth. The proposed BP learning algorithm based on adaptive LMS can overcome the problem that the error-driven learning algorithm cannot be applied due to the transient characteristics of the spike discharge signal.
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Objective@#To evaluate the diagnostic efficacy of Japan Narrow Band Imaging Expert Team(JNET) classification under narrow-band imaging (NBI) for colorectal laterally spreading tumors.@*Methods@#Data of 170 laterally spreading tumors (LST) detected by NBI and pigment dyeing were reviewed in the retrospective study. JNET classification under NBI was used for rediagnosis based on surface pattern and vessel pattern. Pit pattern(PP) was observed under pigment dyeing using PP classification. The results were compared with histologic results after endoscopic resection or surgery.@*Results@#The diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy of JNET classification and PP classification were 92.2% VS 70.3%, 82.3% VS 85.0%, 74.7% VS 72.6%, 94.9% VS 83.5%, 85.9% VS 79.7%, respectively (P=0.159). The consistency rates of JNET classification and PP classification in predicting shallow invasion depth of LST were 6.1% and 8.3% respectively and the consistency rates in predicting deep invasion were 30.8% and 4.8%, respectively.@*Conclusion@#JNET classification under NBI is effective in predicting malignant laterally spreading tumors, however, its efficacy in predicting tumor invasion depth is unsatisfied. PP classification can be used to improve the diagnostic accuracy for those with diagnostic difficulty.
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Objective To evaluate the diagnostic efficacy of Japan Narrow Band Imaging Expert Team(JNET)classification under narrow-band imaging (NBI)for colorectal laterally spreading tumors. Methods Data of 170 laterally spreading tumors (LST)detected by NBI and pigment dyeing were reviewed in the retrospective study. JNET classification under NBI was used for rediagnosis based on surface pattern and vessel pattern. Pit pattern(PP)was observed under pigment dyeing using PP classification. The results were compared with histologic results after endoscopic resection or surgery. Results The diagnostic sensitivity,specificity, positive predictive value, negative predictive value and accuracy of JNET classification and PP classification were 92. 2％ VS 70. 3％,82. 3％ VS 85. 0％,74. 7％ VS 72. 6％,94. 9％VS 83. 5％,85. 9％ VS 79. 7％,respectively (P= 0. 159). The consistency rates of JNET classification and PP classification in predicting shallow invasion depth of LST were 6. 1％ and 8. 3％ respectively and the consistency rates in predicting deep invasion were 30. 8％ and 4. 8％,respectively. Conclusion JNET classification under NBI is effective in predicting malignant laterally spreading tumors,however,its efficacy in predicting tumor invasion depth is unsatisfied. PP classification can be used to improve the diagnostic accuracy for those with diagnostic difficulty.
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Background:DNA methylation is a vital part of epigenetic modification,and is closely related with the development and progress of multiple tumors such as colorectal cancer. However,its mechanism is not fully clarified. Screening specific methylation gene and construct the methylation expression profile of tumor has become the current research hotspot. Aims:To screen the differential methylation loci in colorectal cancer and para-cancerous normal tissue by gene methylation microarray technique,and to construct specific differential methylation gene profile of colorectal cancer. Methods:Methylation 450K bead-chip was applied to detect the methylation status in colorectal cancer and para-cancerous normal tissues of 6 cases. A total of 431 467 loci were analyzed and compared. Aberrant methylation loci were screened according to P value,and the hypermethylation loci and hypomethylation loci were differentiated by delta beta value. Moreover,the function of differential methylation gene was further analyzed by GO analysis and KEGG analysis. Results:A total of 3 649 differential methylation loci were found by comparing colorectal cancer tissue and para-cancerous normal tissue,including 1 259 hypermethylation loci,which mainly located in promoter and genosome,and 2 390 hypomethylation loci,which mainly located in intergenic region and genosome. A panel of aberrant methylation gene loci was screened out,including hypermethylation gene loci such as SLC15A3 and hypomethylation gene loci such as ACOT2,TTLL8 and UHRF1. GO analysis and KEGG analysis showed that the function of these genes might be correlated with DNA binding,transcription factor activity and signal transduction pathway. Conclusions:There are many differential methylation loci in colorectal cancer and para-cancerous normal tissues,suggesting that aberrant DNA methylation is closely related with the development and progress of colorectal cancer. DNA methylation microarray technique could be applied for preliminary screening of differential methylation loci. However,constructing the differential methylation profile in colorectal cancer as a clinical biomarker should be further validated.
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Objective To explore the feasibility,safety and efficacy of customized porous tantalum acetabular patch made by three-dimensional (3D) printing technique in treating adult developmental dysplasia of the hip (DDH).Methods Eight adult patients with Crowe Ⅰ type DDH (2 men and 6 women,with a mean age of 43.75±7.81 years,range 33-58 years) who were treated with 3D printed customized porous tantalum acetabular patch hip reconstruction from January 2017 to September 2017 were included.The 3D printing technique was used for reconstructing and designing the optimal acetabular patch for the personalized hip joint of each patient.The acetabular patch was subjected to porous processing and finite element analysis until the biomechanical requirements were met.The 3D printing of porous tantalum acetabular patch and post-processing was subsequently performed.The acetabular patch was implanted through the anterior approach of the hip joint.The operative duration,intraoperative blood loss and complications were recorded.All the included patients were followed up at 1.5,3 and 6 months postoperatively.Pain was assessed using the visual analog scale (VAS),and the hip joint function was evaluated using the Harris score and gait analysis.The patients underwent anterior-posterior radiography and 3D computed tomography of the hip joint aiming to observe the position of the acetabular patch and osteoarthritis progression.Results The mean operative duration was 1.13±0.23 h,and the mean blood loss was 114.17±41.22 ml.All patients were followed up for 6 to 12 months,with an average of 8.2 months.The mean lateral central-edge angle and anterior central-edge angle ranged from 9.83°±5.34° preoperatively to 32.67°±2.53° postoperatively and from 3.83°± 2.79° preoperatively to 21.67°± 1.87° postoperatively,respectively.The rate of acetabular coverage increased from 57.33％±7.97％ preoperatively to 87.33％±4.56％ postoperatively.The VAS and Harris scores ranged from 2.92± 0.79 preoperatively to 0.83±0.72 postoperatively and from 69.67±4.62 preoperatively to 84.25±4.14 postoperatively with statistically significant difference,respectively.The results of gait analysis showed that the step speed,stride,the range of motion of hip and knee were better than that preoperatively.The images suggested a close contact between the tantalum acetabular patch and the iliac bone without loosening and progress of osteoarthritis in hip joint.Conclusion 3D printed customized porous tantalum acetabular patch could reconstruct the defect of acetabular,increase the coverage,and delay the progress of osteoarthritis of the hip joint.This method could reduce the difficulty of hip reconstruction,and the patients could obtain better joint function at the early stage.
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BACKGROUND:There are a variety of treatments for femoral head necrosis,but their efficacy is not confirmed and unified.How to improve the differentiation ability of osteoblasts in the femoral head and improve the biomechanical support after the repair of the femoral head is an urgent problem to be solved.OBJECTIVE:To explore the clinical outcome of stem cells combined with vascularized iliac bone flap and tantalum rod implantation for the treatment of osteonecrosis of the femoral head (ONFH).METHODS:Totally 28 cases (36 hips) of non-traumatic ONFH admitted at the Zhongshan Hospital of Dalian University from January 2010 to January 2011 were enrolled.Bone marrow samples were extracted from each patient to isolate bone marrow stromal stem cells which were cultured in vitro for 2 weeks.Tantalum rod implantation with vascularized iliac bone graft was conducted to restore the femoral head shape,and then,prepared stem cell suspension were injected into the iliac bone flap and into the subchondral space of the femoral head.RESULTS AND CONCLUSION:All the 28 cases (36 hips) were followed up for 6-20 months (average 12 months),and their Harris hip scores and visual analogue scale scores at postoperative 6 and 12 months were significantly higher than the baseline (P ＜ 0.05).The Harris hip score at postoperative 12 months was significantly higher than that at postoperative 6 months (P ＜ 0.05),but there was no significant difference in the visual analogue scale scores at 6 and 12 months postoperatively (P ＞ 0.05).At the end of 12-month follow-up,clinical outcomes were excellent in 13 hips,good in 15 hips,fair in 4 hips,and poor in 4 hips,with an excellent and good rate of 90％.These findings indicate that autologous bone marrow stromal stem cell transplantation with vascularized iliac bone flap and tantalum rob implantation is an effective method with high clinical success rate for the treatment of ONFH.
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BACKGROUND:Cervical spondylosis refers to cervical intervertebral spondylotic myelopathy and secondary degenerative changes, as wel as pathological changes in surrounding tissue structures. Establishing animal model of cervical instability and vertebral-basilar artery ischemia is the key in the studies addressing cervical spondylosis pathophysiology and treatment. OBJECTIVE:To establish animal model of unstable cervical spine and vertebral-basilar artery ischemia, and explore new progress of animal model imitation study. METHODS:A computer-based retrieval of PubMed database and CNKI database was performed for articles published from 1979 to 2012. The key words were“cervical instability, basal-vertebral artery ischemia, animal model”in English and Chinese. The articles about cervical instability, basal-vertebral artery ischemia, and animal model were screened, and those published recently or in authorized journals were preferred in the same field. Final y 43 articles were included in this study. RESULTS AND CONCLUSION:An ideal animal model of cervical disease is needed. Animal model of cervical diseases is often used for the study of disease causes, onset mechanism and biochemistry. As the causes and mechanism of cervical diseases remain unclear, the existing modeling method cannot duplicate human cervical diseases, so further studies are needed to explore the establishment of models, positive rate and modeling time.
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Objective To investigate the possible injury mechanism of human kidney proximal tubular epithelial cell-2 (HK-2) induced by aristolochic acid (AA). Methods Cultured HK-2 cells were divided into 4 groups:normal control,treated by AA at the concentration of 30,60 and 120 ?mol/L for 48 h respectively. The morphological changes were observed by inverted phase contract microscopy. The cell viability was measured by the Cell Counting Kit-8 (CCK8) assay. Apoptotic cells were identified by flow cytometry. Expression of active Caspase-3 was measured by Western blot analysis. Automatic biochemical analyzer was used to detect the contents of LDH and ?-N-Acetylglucosaminidase (NAG) in the supernatant. The expression of E-cadherin and a-SMA was detected with laser scanning confocal microscope (LSCM). Enzyme linked immunosorbent assay (ELISA) was used to measure the levels of TGF-?1 and collagen Ⅲ in the supernatant quantitatively. Results AA inhibited HK-2 cells proliferation,induced cell apoptosis and activated Caspase-3 expression,and increased the LDH and NAG levels. All of these were in a concentration-dependent manner. AA at the concentration of 60 ?mol/L inhibited E-cadherin expression,increased ?-SMA expression and TGF-?1 and collagen Ⅲ secretion. Conclusion AA inhibits cell proliferation,induces apoptosis and epithelial-mesenchymal transition (EMT) in HK-2 cells. AA at relatively low concentration (≤60 ?mol/L) mainly induces EMT in HK-2 cells,while,that at high concentration (≥120 ?mol/L) causes apoptosis and cytotoxicity.
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AIM:To approach the therapeutic effects of mycophenolate mofetil(MMF)in hormonal resistance nephrotic syndromes.METHODS:Patients were diagnosed as nephrotic syndrome and treated with prednisone at the dose of 1 mg?kg-1?d-1 for over 8 weeks,and 24 patients with unsatisfactory results or were palindromic were selected,and several patients in the 24 patients had been treated with cyclophosphamide or cyclosporine A.All patients were treated with MMF combined with low dose hormone.The initial dose of MMF was 1.0-1.5 g/d for 3 months,later the dose were reduced,and the maintenance dose of MMF was 0.5-1.0 g/d,the dose of prednisone was 5-20 mg/d,the follow-up visit period more than six months.The changes on urine protein,serum albumin,liver function,renal function were compared before and after treatment.RESULTS:Before and after treatment,urine protein decreased from(3.4?1.7)g/d to(0.9?0.2)g/d,serum albumin increased from(19.6?5.4)g/L to(36.1?7.7)g/L.serum creatinine level decreased from(105.7?6.4)?mol/L to(90.1?5.8)g/L.20 patients(83.3%)pathogenetic condition were relieved,15 patients(65.2%)were with complete remission.5 patients(20.8%)were partially recovered,and 4 patients(16.6%)had no response.The adverse effects were observed,including gastrointestinal events(n=8,33.3%),bacterial pneumonia(n=4,16.6%),herpes zoster(n=1,4.1%),hepatic function mild damage(n=3,12.5%).CONCLUSION:It is safe and effective to combine MMF with low dose hormone in treatment of hormonal resistance nephrotic syndrome,which could become a therapeutic option for refractory nephrotic syndrome(RNS).