Effect of mitogen-activated protein kinase signaling pathway on apoptosis of acute promyelocytic leukemia NB4 cell line induced by puerariae radix flavones / 白血病·淋巴瘤

Objective:To investigate the relationship between mitogen-activated protein kinase (MAPK) signaling pathway related signal molecules and the apoptosis of acute promyelocytic leukemia NB4 cells induced by puerariae radix flavones (PRF) and its significance.Methods:The cells were divided into control group [0.025% dimethyl sulfoxide (DMSO) to replace PRF] and 10, 30, 50 μg/ml PRF groups. The proliferation inhibition rate of NB4 cells exposed with PRF for 24, 48 and 72 hours was determined by methyl thiazolyl tetrazolium (MTT) method, and the nuclear morphology was determined by confocal laser scanning microscope after 48 hours. NB4 cells were divided into control group (adding 0.025% DMSO) and 10, 30 and 50 μg/ml PRF with or without 10 μmol/L c-Jun N-terminal kinase (JNK) inhibitor (SP600125) group, and the cells were treated for 48 hours and the changes in the expressions of MAPK pathway related proteins JNK, tumor necrosis factor α (TNF-α), extracellular signal-regulated kinase (ERK) and p38 MAPK were tested by Western blot.Results:10, 30 and 50 μg/ml PRF inhibited the proliferation of NB4 cells in 24, 48 and 72 hours, which was in time- and dose-dependent manners (all P < 0.05). The half-maximal inhibitory concentration (IC 50) at 24, 48 and 72 hours were (40.03±2.23) μg/ml, (22.92±1.72) μg/ml and (17.99±1.48) μg/ml, respectively. The confocal laser scanning microscope showed that NB4 cells displayed distinct apoptotic characteristics after PRF treatment. After co-cultivating NB4 cells with 10 μmol/L SP600125 and different concentrations of PRF for 48 hours, the expression of JNK1 in NB4 cells was suppressed ( P < 0.05), and the expressions of JNK2/3 and p38 MAPK decreased, but the differences were not statistically significant (both P > 0.05). The expressions of ERK1 and ERK2 gradually increased in the single-drug group, while the expression in the combined drug group decreased. The expression of TNF-α in the 50 μg/ml PRF+SP600125 group was down-regulated compared with the 50 μg/ml PRF single-drug group, while the expressions in the 10 and 30 μg/ml PRF+SP600125 groups were up-regulated compared with the 10 and 30 μg/ml PRF single-drug groups. Conclusion:10-50 μg/ml PRF may activate the MAPK signaling pathway through TNF-α. JNK, ERK1/2 and p38 MAPK interact with each other to activate pro-apoptotic related proteins and induce NB4 cells apoptosis.

Robust MR image segmentation using the trimmed likelihood estimator in asymmetric Student's-t mixture model.

Finite mixture model (FMM) has been widely used for unsupervised segmentation of magnetic resonance (MR) images in recent years. However, in real applications, the distribution of the observed data usually contains an unknown fraction of outliers, which would interfere with the estimation of the parameters of the mixture model. The statistical model-based technique which provides a theoretically well segmentation criterion in presence of outliers is the mixture modeling and the trimming approach. Therefore, in this paper, a robust estimation of asymmetric Student's-t mixture model (ASMM) using the trimmed likelihood estimator for MR image segmentation has been proposed. The proposed method is supposed to discard the outliers, and then to estimate the parameters of the ASMM with the remaining samples. The advantages of the proposed algorithm are that its robustness to dispose the disturbance of outliers and its flexibility to describe various shapes of data. Finally, expectation-maximization (EM) algorithm is adopted to maximize the log-likelihood and to obtain the estimation of the parameters. The experimental results show that the proposed method has a better performance on the segmentation of synthetic data and real MR images.

Image recognition with missing-features based on gaussian mixture model and graph constrained nonnegative matrix factorization.

The demand for automatically recognizing medical images for screening, reference and management is growing faster than ever. Missing data phenomenon in medical image applications is common existence, and it could be inevitable. In this paper, we have addressed the problem of recognizing medical images with missing-features via Gaussian mixture model (GMM)-based approach. Since training a GMM by directly using high-dimensional feature vectors will result in instability, we have proposed a novel strategy to train the GMM from the corresponding reduced-dimensional one. The proposed method contains training and test phases. The former contains feature extraction, graph constrained nonnegative matrix factorization (NMF), GMM training, and the alternating expectation conditional maximization (AECM) for extending the reduced-dimensional GMM. In test phase, two methods, marginalizing GMM using Bayesian decision (MGBD) and conditional mean imputation (CMI), are applied to impute missing-features. Posterior probability of test images is calculated to identify objects. Experimental results on three real datasets demonstrate the feasibility and efficiency of the proposed scheme.

Apoptosis of leukemic cells induced by flavonoids of puerarin and its molecular mechanisms / 白血病·淋巴瘤

Objective To explore the effects and the possible molecular mechanism of flavonoids of puerarin (PR) on chronic myelogenous leukemia (CML) cell line K562 and acute promyelocytic leukemia (APL) cell line NB4 in vitro. Methods MTT assays were used to detect the inhibitory effects of cell proliferation. The apoptosis of K562 and NB4 cells was detected by flow cytometry marked with Annexin V/PI. The expression of bcr-abl, p53, bcl-2, Fas/FasL in K562 cells and JNK, PARP, bcl-2 and Caspase 3 in NB4 cells at protein level was detected by Western blot. Results PR could inhibit the proliferation of K562 and NB4 cells in a time-dose dependent manner. The expression of protein levels of bcr-abl fusion gene declined, while the p53 protein otherwise increased, and both were in a dose-dependent manner (F = 18.74, P <0.05). The application of PR had no effect on bcl-2 and Fas/FasL protein expression in K562 cells. The JNK, PARP and Caspase3 proteins were upregulated in NB4 cells, while bcl-2 was downregulated with the increasing concentrations of PR (F=42.32, P <0.05). Conclusion PR could inhibit leukemic cell proliferation, induce cell cycle block, and increase cell apoptosis through different molecular mechanisms. It suggestes that PR might potentially be a kind of broad spectrum anti-leukemia agent.

Investigation on compliance of forbidden depasturing livestock on marshland with Oncomelania snails in schistosomiasis endemic areas / 中国血吸虫病防治杂志

Objective To study the compliance of forbidden depasturing livestock on the marshland with Oncomelania snails in schistosomiasis endemic areas. Methods According to 3 levels of human infection rates as > 10% ,5%-10% and <5% , 2 204 residents selected randomly from the schistosomiasis endemic villages were sampled with the stratified cluster sampling method in Hunan, Hubei, Jiangxi, Anhui, Jiangsu, Sichuan and Yunnan provinces, and investigated by questionnaire. The contents of the questionnaire included the recognition and implementation of forbidden depasturing livestock on marshland with Oncomelania snails and breeding livestock in bam. Results A total of 78.4% residents agreed forbidden depasturing livestock on marshland with snails, but 3. 7% residents disagreed it. A total of 83. 9% residents considered the relationship between breeding livestock in bam and schistosomiasis control, but 3. 1% residents thought that it was no relationship. The main reasons of depasturing livestock on marshland with Oncomelania snails were the high cost of breeding livestock in bam (36. 2% ) , unaccustomed (26.4% ) and no room for breeding livestock in bam (25.4% ). Conclusion Forbidden depasturing livestock on the marshland with Oncomelania snails should be strengthened according to the local economic, nature environment, agriculture, residents'culture degree and agriculture habit.

RELATIONSHIP OF THE LIVESTOCK TRADE TO SCHISTOSOMIASIS TRANSMISSION IN MOUNTAINOUS AREA / 中国寄生虫学与寄生虫病杂志

[Objectice] To study the relationship between the livestock trade and schistosomiasis transmission and to provide an evidence for making a strategy of schistosomiasis control in mountainous areas. [Methods] A retrospective survey and analysis was conducted to investigate the prevalence of schistosomiasis in both humans and livestock (cattle, horses, mules, donkeys and pigs), and the number and migration of livestock in Weishan County, Yunnan Province in 1980～ 1991. [Results] A positive correlation was found between the infection rate of residents and the numbers of livestock migration (R=0. 9151, P＜0.01). During 1980 to 1991 the infection rate was increased gradually along with the development of livestock husbandry, especially, from the economic reforms since 1984. In 1984 there was positive correlation in the infection rate both human and livestock (R=0. 8458, P＜0.05). The results show that the infection rates of livestock on sale including cattle, horses, mules, donkeys and pigs are 9.54%, 29.39%, 16.38%, 14.47%, 25.73% and 11.11%, respectively. [Conclusion] The infection rate of human and livestock arises by parallel. The high frequency of livestock trade resulted in serious spreading of the infection source of schistosomiasis. The migration of the infected livestock might be an important factor in transmitting schistosomiasis.