Effects of carvedilol on murine viral myocarditis

AIM: To observe the effects of carvedilol on murine viral myocarditis model. METHODS: A total of 188 inbred male BALB/c mice of 4-6 weeks were divided into 4 groups: myocarditis group (group C, n=60), metoprolol treatment group (group M, n=60), carvedilol treatment group (group K, n=60), control group (group B, n=8). Myocardial histopathololgic changes were observed. The concentrations of cardiac troponin I (cTn-I) were detected by chemiluminescence immunoassay (CLIA). Western blotting was performed to analyze the contents of phosphorylated p38MAPK in myocardium. RESULTS: Metropolol and carvedilol lightened myocardial histopathololgic changes at acute stage, decreased cTn-I concentrations and myocardial phosphorylated p38MAPK value compared with myocarditis group. Treatment with carvedilol was more effective than treated with metropolol on those indexes. CONCLUSION: Carvedilol protects against viral myocarditis by inhibition of p38MAPK signal transduction pathway through blockade of β1 and β2 adrenergic receptors.     

Impact of serial activation of embryonic pax2 and WT1 genes on transdifferentiation of renal tubular epithelial cells

AIM: To investigate the mechanisms of transdifferentiation of renal tubular epithelial cells by the observation of serial activation of embryonic pax2 and WT1 genes in chronic renal failure model of 5/6 nephrectomized injury. METHODS: Embryo of mice, cultured renal tubule cells and chronic renal failure rat model of 5/6 nephrectomized injury were established. The expressions of paired Box gene (pax2) and Willm’s tumor gene (WT1), as well as α-smooth muscle actin (α-SMA), a phenotype of mesenchymal cells, were detected by RT-PCR and immunohistochemistry techniques. RESULTS: (1) Expressions of pax2 and WT1 mRNA began at 11.5 d and 14 d of embryo and increased gradually, and expression in trace quantity at 2 weeks after birth. Immunohistochemistry analysis revealed that WT1 only expressed in the glomerular podocytes and expressions of pax2 and WT1 in adult renal tubular cells were negative. (2) Deno-expression of pax2 and WT1 in some tubular cells appeared at week 2 and peaked at week 4 in 5/6 nephrectomized rats, both showing a same trend of expression. However, pax2 showed another peak at week 10 afterwards. (3) Re-expressions of pax2 and WT1 in TEC at 0.5 and 24 h after treated with IL-1α (10 μg/L) or AngII (10-9 mol/L) were observed respectively, followed by upregulation of α-SMA expression, and mesenchymal cells characters were shown. The effects were inhibited by Ang II receptor 2 antagonist and WT1 antibody, respectively. CONCLUSION: Adult renal tubule cells acquire re-activation of embryonic pax2 and WT1 genes and phenotypes of mesenchymes when challenge with certain injuries. Deno-expression of pax2 and WT1 genes closely relates with high concentration of bioactive facors, such as AngII and IL-1, which are involved in the mechanisms of renal tubule cells transdifferentiation.     

13-MTD induces apoptosis of MCF-7 breast cancer cells by activating MAPK pathway and inhibiting Akt signaling

［ABSTRACT］AIM: To study the effect of 13-methyltetradecanoic acid (13-MTD), a saturated branched-chain fatty acid, on apoptotic induction in breast carcinoma cell line MCF-7 and its underlying mechanisms. METHODS: Breast carcinoma cell line MCF-7 and normal breast epithelial cells MaEC were treated with solvent or 13-MTD at concentration of 140 mg/L. Apoptosis was analyzed by flow cytometry. Phosphorylation of JNK, p38, FADD and Akt after treated with 13-MTD were detected by Western blotting. RESULTS: 13-MTD effectively induced apoptosis of breast carcinoma cell line MCF-7 and no influence to normal breast epithelial cells MaEC, which were confirmed by flow cytometry analysis, was observed. The results of Western blotting showed that obvious increase in p38 and JNK phosphorylation. No significant difference of FADD phosphorylation was observed. However, evidently decrease in Akt phosphorylation was found after treated with 13-MTD. CONCLUSION: 13-MTD was a new safe, effective chemotherapeutic drug. Its underlying mechanisms are through activating MAPK pathway and inhibiting Akt pathway to induce the cancer cells apoptosis.     

Effects of salvianolic acid B on neurons during oxygen/glucose deprivation and reintroduction

AIM: To observe the damage induced in the primary cultured rat cortical neurons by oxygen/glucose deprivation and reintroduction, and to investigate the neuroprotective mechanism of salvianolic acid B (SalB). METHODS: Primary cultured rat cortical neurons were randomly divided into the control group, the model group and the SalB group. The cell model was established by oxygen/glucose deprivation for 3 h followed oxygen/glucose reintroduction for 24 h. The cortical neurons viability was determined by MTT assay. The leakage rate of lactate dehydrogenase (LDH) was measured by chromatometry. The mitochondrial membrane potentials (MMP) and the apoptosis rate were quantitatively analyzed by flow cytometry. The cytosolic free calcium was assessed using LSCM. The morphologic changes of neuronal nuclei were observed by Hoechst 33342 fluorescence staining. RESULTS: Compared to the model group, the cortical neurons viability, the survival rate and the fluorescence value of MMP in the SalB group were obviously increased (P<0.05,P<0.01). In addition, in the SalB group, the leakage rate of LDH, the fluorescence intensity of cytosolic free calcium and the apoptosis rate were significantly lower than those in the model group (P<0.01). CONCLUSION: The neuroprotective mechanism of SalB in the oxygen/glucose deprivation and reintroduction neurons would be due to the fact that SalB maintains the MMP and the calcium homeostasis.     

不同木豆品种的生物学和品质特性比较研究

以广西地方木豆品种为对照,与引进的其他7个木豆新品种进行田间比较试验,评价引进木豆品种的种性和生态适应性.结果表明:不同木豆品种的根、茎、叶、花、荚、籽粒、株型等形态特征,萌芽、生长、开花、生长期、抗病虫性等生长特性以及茎、叶、籽粒的粗蛋白、粗脂肪、粗淀粉含量都有显著差异.根据不同品种的表现:广西品种、非洲品种、缅甸品种、ICPL87119比较适应喀斯特石山区荒地、山地种植,可作为饲料、水土保持、生态保护、薪炭林等用途,ICPH8、IC-PL87091可作蔬菜和粮食用,其中ICPL87091是一个比较有希望的品种.     

中国食糖供求分析与预测

利用预测模型从原料生产的角度,分析了我国食糖供给的变化趋势;然后从居民用糖和工业用糖两个方面,研究了食糖需求的变化;最后从贸易的角度,探讨了我国满足国内食糖供需缺口的可能途径。研究发现：食糖的供给潜力主要在于甘蔗糖方面;需求方面,工业用糖量增长较快,是推动食糖需求增长的主要动力。由于食糖需求增长的速度快于供给的增长,我国食糖的供求缺口有不断增加趋势。为避免食糖体系失衡风险,增加国内食糖供给才是解决我国食糖供求矛盾的最佳途径。     

捕捞对海洋鱼类群落影响的研究进展

随着渔业资源由单鱼种管理模式向基于生态系统管理策略的转变,捕捞因素对于鱼类群落结构的影响正逐步成为海洋生态系统的研究热点。本文主要就捕捞对鱼类群落影响的国内外研究方法进行了综述与归纳。在研究捕捞对于鱼类群落影响时,所选用的群落研究指标应符合预期性、可测性、敏感性和排他性标准,业已利用的研究方法大致可分为生物多样性、聚合特征指标、群落功能性指标、多元分析以及生态系统模型五大类。各研究方法单独使用均无法全面反映群落的结构变化,在实际研究过程中建议同时使用多种研究方法来进行鱼类群落结构的变化分析,以期全面掌握捕捞活动作用下的鱼类群落结构的实际变动状况,更好地为渔业资源的科学管理提供理论支撑。[中国水产科学,2008,15（2）：359—366]     

基于核K—均值聚类算法的植物叶部病害识

针对植物叶部病害图像的特点,首先对采集到的玉米病害彩色图像采用矢量中值滤波法去除噪声,然后提取玉米病叶彩色图像的纹理特征和颜色特征作为特征向量,利用Mercer核,把输入空间的样本映射到高维特征空间进行K-均值聚类以及植物病害识别.试验涉及的4种玉米病害识别正确率达82.5%,核K-均值聚类方法适合玉米叶部病害分类.     

基于粗糙集与支持向量机的禽蛋蛋壳无损检

针对当前禽蛋蛋壳无损检测系统存在检测精度不高的问题,提出粗糙集和支持向量机相结合的方法进行分类器的设计.首先,基于粗糙集理论对特征参数集进行属性约简,在约简过程中,利用模糊C均值聚类算法对特征参数进行量化,并基于属性重要性的启发式搜索对条件属性进行约简;然后,在属性约简的基础上完成支持向量机分类器的训练,在训练过程中,通过交叉验证法对分类器模型参数进行了优化.实验结果表明该方法的分类准确率能够达到94.6%,具有良好的工程应用价值.     

驱动圆盘犁的研究与设计

驱动圆盘犁对土堡侧面和底部的土壤进行旋转滑切,将土垡底部的土壤由沟底撕裂开形成土垡,并利用圆盘的旋转将土垡抬升并翻转.为此,以研究驱动圆盘犁为目标,分析了驱动圆盘犁各几何参数和工作参数对其工作过程的影响,为驱动圆盘犁的研制提供了可靠的理论依据.通过理论分析,阐明了驱动圆盘犁的运动学特性,推导了残耕高度的计算公式.