Bcl-2 upregulation by HIV-1 tat during infection of primary human macrophages in culture

The ability of cells of the human monocyte/macrophage lineage to host HIV-1 replication while resisting cell death is believed to significantly contribute to their ability to serve as a reservoir for viral replication in the host. Although macrophages are generally resistant to apoptosis, interruption of anti-apoptotic pathways can render them susceptible to apoptosis. Here we report that HIV-1(BAL )infection of primary human monocyte-derived macrophages (MDM) upregulates the mRNA and protein levels of the anti-apoptic gene, Bcl-2. Furthermore, this upregulation can be quantitatively mimicked by treating MDM with soluble HIV-1 Tat-86 protein. These results suggest that in infecting cells of the monocyte/macrophage lineage, HIV-1 may be benefiting from additional protection against apoptosis caused by specific upregulation of cellular anti-apoptotic genes.     

Membrane‐binding mechanism of a bacterial phospholipid N‐methyltransferase

The membrane lipid phosphatidylcholine (PC) is crucial for stress adaptation and virulence of the plant pathogen Agrobacterium tumefaciens. The phospholipid N‐methyltransferase PmtA catalyzes three successive methylations of phosphatidylethanolamine to yield PC. Here, we asked how PmtA is recruited to its site of action, the inner leaflet of the membrane. We found that the enzyme attaches to the membrane via electrostatic interactions with anionic lipids, which do not serve as substrate for PmtA. Increasing PC concentrations trigger membrane dissociation suggesting that membrane binding of PmtA is negatively regulated by its end product PC. Two predicted alpha‐helical regions (αA and αF) contribute to membrane binding of PmtA. The N‐terminal helix αA binds anionic lipids in vitro with higher affinity than the central helix αF. The latter undergoes a structural transition from disordered to α‐helical conformation in the presence of anionic lipids. The basic amino acids R8 and K12 and the hydrophobic amino acid F19 are critical for membrane binding by αA as well as for activity of full‐length PmtA. We conclude that a combination of electrostatic and hydrophobic forces is responsible for membrane association of the phospholipid‐modifying enzyme.     

黄花菜固体饮料配方及喷雾干燥工艺的研究

本研究旨在研制一种基于黄花菜的固体饮料。以黄花菜为主要原料,以感官评分、冲泡性能为指标,采用响应面试验对黄花菜固体饮料的配方和干燥工艺进行优化。试验表明,黄花菜固体饮料配方的响应面优化结果为:食盐添加量0. 01%,麦芽糊精添加量2. 0%,马铃薯全粉添加量1. 0%,奶粉添加量4. 5%,黄花菜与水比值1∶9(m∶v);此配方下研制出的黄花菜固体饮料流动性最佳,表征值为72. 855 mm。喷雾干燥的最佳工艺参数是进风温度为180℃,入料流量为1. 5 mL/min;所得样品的感官评分值为94. 2,流动性表征值为71. 65mm,润湿性表征值为27. 75 min。     

Focus: Personalized Medicine: Tailoring the Treatment of Melanoma: Implications for Personalized Medicine

Oncology has been revolutionized by the ability to selectively inhibit the growth of cancerous cells while ostensibly avoiding the disruption of proteins and pathways necessary for normal cellular function. This paradigm has triggered an explosion of targeted therapies for cancer, creating a burgeoning billion-dollar industry of small molecules and monoclonal antibodies [1]. Largely due to these new treatments, spending on cancer pharmaceuticals has surpassed $100 billion worldwide [2]. In particular, the treatment of melanoma, a deadly and fast-spreading form of skin cancer, has been transformed by these new targeted therapies. In this mini-review, we summarize the progress made in the field of personalized treatment of melanoma, with an emphasis on targeted therapies. We then outline future directions for treatment, including novel cell-mediated therapies and new potential targets.     

Development of Resistance to Pyrethroid in Culex pipiens pallens Population under Different Insecticide Selection Pressures

Current vector control programs are largely dependent on pyrethroids, which are the most commonly used and only insecticides recommended by the World Health Organization for insecticide-treated nets (ITNs). However, the rapid spread of pyrethroid resistance worldwide compromises the effectiveness of control programs and threatens public health. Since few new insecticide classes for vector control are anticipated, limiting the development of resistance is crucial for prolonging efficacy of pyrethroids. In this study, we exposed a field-collected population of Culex pipiens pallens to different insecticide selection intensities to dynamically monitor the development of resistance. Moreover, we detected kdr mutations and three detoxification enzyme activities in order to explore the evolutionary mechanism of pyrethroid resistance. Our results revealed that the level of pyrethroid resistance was proportional to the insecticide selection pressure. The kdr and metabolic resistance both contributed to pyrethroid resistance in the Cx. pipiens pallens populations, but they had different roles under different selection pressures. We have provided important evidence for better understanding of the development and mechanisms of pyrethroid resistance which may guide future insecticide use and vector management in order to avoid or delay resistance.     

rpoS基因缺失突变对荧光假单胞菌胁迫耐受性、群体感应及腐败活性的影响

【目的】微生物活动是引起食品腐败的主要原因,研究食品腐败菌的腐败作用调控机制对于保证食品的质量和安全具有重要意义。荧光假单胞菌是一种代表性的食品腐败菌,本文旨在研究RNA聚合酶的选择性sigma因子Rpo S在荧光假单胞菌致腐败过程中的作用。【方法】运用同源重组的方法构建荧光假单胞菌冷藏鱼分离株的rpo S基因缺失突变株,比较野生型和突变株暴露于不同胁迫条件下的存活率;通过液相色谱-串联质谱(LC-MS/MS)分析野生型和突变株产生高丝氨酸内酯类(AHLs)群体感应信号分子的种类和含量;检测野生型和突变株接种于灭菌三文鱼汁后4°C贮存过程中的菌落总数和挥发性盐基氮的生成量。【结果】成功构建了荧光假单胞菌rpo S基因缺失突变株。rpo S基因的缺失导致荧光假单胞菌对10 mmol/L H2O2和15%乙醇的耐受性显著降低,对150μg/m L结晶紫和175 mmol/L醋酸的耐受性有一定程度增强,不影响其对47°C和20%Na Cl的耐受性。荧光假单胞菌在rpo S基因缺失突变后长链信号分子C_(10)-HSL、C_(12)-HSL和C_(14)-HSL的含量增加。在灭菌三文鱼汁中的腐败活性检测表明rpo S基因缺失可导致荧光假单胞菌挥发性盐基氮的生成量显著降低。【结论】荧光假单胞菌的Rpo S不仅调节细菌对多种胁迫条件的耐受性,还影响AHL群体感应和腐败活性。     

应用底栖动物完整性指数B-IBI评价溪流健康

B-IBI指数是溪流生态系统健康评价常用指标之一。据安徽黄山地区溪流的33个底栖动物样点数据(11个参照点,22个受损点),对21个生物参数进行分布范围、Pearson相关性和判别能力分析,确定B-IBI指数由总分类单元数、EPT分类单元数、前3位优势分类单元%、粘附者%、敏感类群%和BI指数构成。分别用3分制、4分制和比值法统一各参数量纲,B-IBI指数值即为累加各构成指数的分值或比值。B-IBI箱线图分析表明,上述3种方法计算出的B-IBI值有较高判别能力(IQ=3),能很好地判别参照水体和受损水体,且3者之间具高相关性(r>0.90)。分别依据参照样点和所有样点B-IBI值建立健康评价标准,比较3分制、4分制和比值法对评价结果的准确性,表明用比值法统一各参数量纲并依据所有样点的B-IBI值建立的健康评价标准的准确性优于3分制和4分制法。建立了适合祁门县溪流生态系统健康评价B-IBI标准B-IBI>3.59健康,2.7～3.59亚健康,1.8～2.69一般,0.9～1.79差,B-IBI<0.9极差。祁门县21个样点的水体,14个健康,6个亚健康,1个一般。B-IBI与电导率(r=-0.62,p<0.01)和生境质量(r=0.65,p<0.01)显著相关。     

Identification of the human T-lymphocyte protein-tyrosine kinase by peptide-specific antibodies

We have recently cloned a cDNA from the human T-cell leukemia, JURKAT, having homology with the src-like family of protein-tyrosine kinases. We have made rabbit polyclonal antibodies against the synthetic peptide CKERPEDRPTFDYLRSVLEDFFTATEGQYQPQP (cys-33-pro) deduced from the carboxy-terminal amino acid sequence predicted by the JURKAT cDNA. In this report, we demonstrate that these antibodies immunoprecipitate the protein-tyrosine kinase activity from solubilized membrane extracts from JURKAT T-leukemia cells and from human peripheral blood T-lymphocytes from normal donors. A 58 kd protein, exhibiting protein-tyrosine kinase activity, was specifically immunoprecipitated in both cases. The antibodies failed to crossreact with pp60c-src from human platelets, but did crossreact with the murine T-lymphocyte protein-tyrosine kinase, pp56T-cell.