Establishment of Acute Immunological Liver Injury Wistar Rat Model Induced by Concanavalin A / 广州中医药大学学报

Objective To explore the dosage and injection method of concanavalin A(Con A) for inducing Wistar rats into the acute hepatic injury model. Methods (1)According to the dosage of Con A, 42 Wistar rats were randomly divided into groups A, B, C, D, E, N, 7 rats in each group. Group N was given tail intravenous injection of normal saline as normal control group. Groups A, B, C, D, E were given intravenous injection of 4, 8, 16, 30, 40 mg/kg of Con A respectively. At the 8th hour after modeling, the levels of alanine transaminase(ALT), aspartate aminotransferase(AST), albumin(ALB), interleukin(IL)-2 , IL-10, interferon (IFN)-γ, and tumor necrosis factor(TNF)-αwere detected. And HE staining was used to observe the pathological feature of hepatic tissue. (2)According to the injection method of Con A, 21 Wistar rats were randomly divided into normal control group, intraperitoneal injection group and tail intravenous injection group, 7 rats in each group. The dosage of Con A for the rats in intraperitoneal injection group and tail intravenous injection group was 16 mg/kg. At the 8th hour after modeling, the levels of serum ALT, AST, and ALB were determined. Results The number of abnormal deaths in various dose Con A groups at the end of each experiment was 0 in groups A, B, C, and 2 in group D, and 7 in group E. A small amount of spotty necrosis, inflammatory cell infiltration, and hepatic lobule with almost integrity of structure were found in groups A, B, while obvious bridging-like necrosis was seen in groups C, D. Serum ALT, AST, and ALB levels in intraperitoneal injection group had no statistically significant difference as compared with the normal control group. Conclusion Tail intravenous injection of 16 mg/kg of Con A can be used to induce an acute immunological liver injury rat model successfully.

Supervised nonlinear dimension reduction of functional magnetic resonance imaging data using Sliced Inverse Regression.

Dimension reduction is essential for identifying a small set of discriminative features that are predictive of behavior or cognition from high-dimensional functional magnetic resonance imaging (fMRI) data. However, conventional linear dimension reduction techniques cannot reduce the dimension effectively if the relationship between imaging data and behavioral parameters are nonlinear. In the paper, we proposed a novel supervised dimension reduction technique, named PC-SIR (Principal Component - Sliced Inverse Regression), for analyzing high-dimensional fMRI data. The PC-SIR method is an important extension of the renowned SIR method, which can achieve the effective dimension reduction (e.d.r.) directions even the relationship between class labels and predictors is nonlinear but is unable to handle high-dimensional data. By using PCA prior to SIR to orthogonalize and reduce the predictors, PC-SIR can overcome the limitation of SIR and thus can be used for fMRI data. Simulation showed that PC-SIR can result in a more accurate identification of brain activation as well as better prediction than support vector regression (SVR) and partial least square regression (PLSR). Then, we applied PC-SIR on real fMRI data recorded in a pain stimulation experiment to identify pain-related brain regions and predict the pain perception. Results on 32 subjects showed that PC-SIR can lead to significantly higher prediction accuracy than SVR and PLSR. Therefore, PC-SIR could be a promising dimension reduction technique for multivariate pattern analysis of fMRI.

L0-regularized time-varying sparse inverse covariance estimation for tracking dynamic fMRI brain networks.

Exploration of time-varying functional brain connectivity based on functional Magnetic Resonance Imaging (fMRI) data is important for understanding dynamic brain mechanisms. l1-penalized inverse covariance is a common measure for the inference of sparse structure of functional brain networks, and it has been recently extended to estimate time-varying sparse brain networks by using a sliding window and incorporating a smoothing constraint on temporal variation. However, l1 penalty cannot induce maximum sparsity, as compared with l0 penalty, so l0 penalty is supposed to have superior quality on inverse covariance estimation. This paper introduces a novel time-varying sparse inverse covariance estimation method based on dual l0-penalties (DLP). The new DLP method estimates the sparse inverse covariance by minimizing an l0-penalized log-likelihood function and an extra l0 penalty on temporal homogeneity. A cyclic descent optimization algorithm is further developed to localize the minimum of the objective function. Experiment results on simulated signals show that the proposed DLP method can achieve better performance than conventional l1-penalized methods in estimating time-varying sparse network structures under different scenarios.

Clinical analysis of extraperitoneal laparoscopic radical prostatectomy / 中国综合临床

Objective To evaluate the feasibility and the clinical value of extraperitoneal laparoscopic radical prostatectomy in treatment of localized prostate cancer.Methods Clinical data of 26 patients with localized prostate cancer treated with extraperitoneal laparoscopic radical prostatectomy were analyzed retrospectively.All patients were pathologic diagnosed with prostate cancer by preoperative prostate biopsy or transurethral resection of prostate surgery.Gleason grade was from 6-8.Results Twenty-six operations were successfully accomplished ,without converting to open approach.The operative time was 120-270 min(mean was 165 min) ,the intraoperative blood loss was 180-650 ml (mean was 320 ml) ,indwelling catheter time 12-19 d (mean was 14 d).There were 6 cases with little uroclepsia, satisfactory with urination after contract urethral sphincter for 1-3 Months.Pathologically confirmed all prostate cancer;2 cases of positive margins after surgery plus endocrine therapy.All the cases were followed up from 2 to 36 months.The biochemical recurrence was 5 cases who had undergone endocrine therapy.Conclusion Extraperitoneal laparoscopic radical prostatectomy is a safe and feasible procedure with little trauma, small bleeding and fast recovery which is well worth popularizing.Replace open surgery may become frist choice therapeutic method for localized prostate cancer.