全缘叶绿绒蒿挥发性组分定量结构-色谱保留关系研究

提出顶点及顶点相互作用矢量的概念,并将该矢量用于复杂样本的分子结构表征。采用逐步回归结合统计检测对变量进行筛选后,再用多元线性回归建立了定量结构-色谱保留(QSRR)关系的7变量模型,模型的建模计算值复相关系数(R)为0.990,标准偏差(SD)为1.325;留一法(LOO)交互检验复相关系数(RCV)为0.983,标准偏差(SDCV)为1.696。结果表明该矢量具有较强的分子结构表达能力,模型具有良好的估计能力与稳定性。     

p16和Ki67在非小细胞肺癌组织中的表达及其与预后的关系

目的探讨p16和Ki67在非小细胞肺癌（non-small cell lung cancer,NSCLC）中的表达,研究它们对NSCLC患者预后的影响及其与临床及病理因素之间的关系。方法收集NSCLC术后标本160例及正常肺组织20例（对照组）,应用免疫组化法检测NSCLC组织和正常肺组织中p16和Ki67的表达。结果在NSCLC组织和正常肺组织中,p16和Ki67的阳性表达率分别为23.8%、82.5%和90%、5%,差异有统计学意义（P〈0.05）。多因素分析：PTNM分期、淋巴结转移、p16及Ki67的表达是影响NSCLC根治术后患者预后的独立因素（P〈0.05）;p16阳性组与阴性组5年生存率分别为55.3%和18.0%,差异有统计学意义（P〈0.05）;Ki67阳性组与阴性组5年生存率分别为23.5%和42.9%,差异有统计学意义（P〈0.05）,p16和Ki67表达呈负相关（P〈0.05）。结论 p16和Ki67参与了NSCLC的发生发展,p16和Ki67的表达水平与NSCLC的发展及预后有一定的关系。     

Population structure of arctic lamprey <Emphasis Type="Italic">Lethenteron camtschaticum</Emphasis> from the Kol River (Western Kamchatka)

Phenetic diversity is investigated and the taxonomic status of lampreys (Petromyzontidae) from the Kol basin (Western Kamchatka) is verified. Typically anadromous lamprey, anadromous lamprey forma praecox, resident lamprey, smolts, and larvae of lamprey are discovered and described. Their comparative analysis is made by standard morphometric characters. Differences between the forms by plastic characters depend on size and weight. No significant differences are found by major taxonomic characters between the forms of anadromous and resident lampreys which would indicate their taxonomic separation. Phenetic types of spawners are representatives of the population of one complexly structured species represented by life forms realizing different life history strategies (anadromous and resident), and belong to the species Arctic lamprey Lethenteron camtschaticum (Tilesius, 1811).     

A method to generate recombinant <Emphasis Type="Italic">Salmonella typhi</Emphasis> Ty21a strains expressing multiple heterologous genes using an improved recombineering strategy

Live attenuated Salmonella enterica serovar Typhi Ty21a (Ty21a) is an important vaccine strain used in clinical studies for typhoid fever and as a vaccine vector for the expression of heterologous antigens. To facilitate the use of Ty21a in such studies, it is desirable to develop improved strategies that enable the stable chromosomal integration and expression of multiple heterologous antigens. The phage λ Red homologous recombination system has previously been used in various gram-negative bacteria species to mediate the accurate replacement of regions of chromosomal DNA with PCR-generated ‘targeting cassettes’ that contain flanking regions of shared homologous DNA sequence. However, the efficiency of λ Red-mediated recombineering in Ty21a is far lower than in Escherichia coli and other Salmonella typhimurium strains. Here, we describe an improved strategy for recombineering-based methods in Ty21a. Our reliable and efficient method involves the use of linear DNA-targeting cassettes that contain relatively long flanking ‘arms’ of sequence (ca. 1,000 bp) homologous to the chromosomal target. This enables multiple gene-targeting procedures to be performed on a single Ty21a chromosome in a straightforward, sequential manner. Using this strategy, we inserted three different influenza antigen expression cassettes as well as a green fluorescent protein gene reporter into four different loci on the Ty21a chromosome, with high efficiency and accuracy. Fluorescent microscopy and Western blotting analysis confirmed that strong inducible expression of all four heterologous genes could be achieved. In summary, we have developed an efficient, robust, and versatile method that may be used to construct recombinant Ty21a antigen-expressing strains.     

猞猁肝脏的组织结构观察及EGF在肝脏中的表达

利用切片方法观察了猞猁Felislynx肝脏的组织结构,应用免疫组织化学方法检测了表皮生长因子(EGF)在肝脏中的表达。结果显示,肝脏外被覆一层结缔组织薄膜,肝小叶不规则且分界不清,肝板、肝血窦及狄氏间隙围绕中央静脉呈放射状排列,肝板由一排肝细胞构成。肝细胞呈圆形或多边形,多为单核,少数具双核,肝细胞间比较松散。肝血窦发达,内可见血细胞。EGF阳性反应主要定位于肝细胞质中,表明EGF可能参与细胞新陈代谢过程的调控。     

Genistein inhibits mitochondrial-targeted oxidative damage induced by beta-amyloid peptide 25–35 in PC12 cells

The antioxidative properties of genistein (Gen) have been demonstrated by our previous studies and others, but its potential mechanism was not very clear. Because of the key role of mitochondria in oxidant production, we wondered if mitochondria were one of Gen’s neuroprotective targets. In the present study we investigated whether Gen has protective effects on mitochondria damaged by Aβ25-35. PC12 cells were pre-incubated with or without Gen for 2 h followed by the incubation with 20 μM Aβ25-35 for another 24 h before mitochondrial membrane fluidity (MMF), mitochondrial membrane potential (MMP) , and mitochondrial redox state were measured. The results showed that Gen alleviated the decrease of MMF induced by Aβ25-35, and maintained the MMP. Additionally, Gen promoted the mitochondrial antioxidative capability through increasing the GSH/GSSG ratio, GPx activity and MnSOD protein expression in mitochondria. Moreover, Gen reversed the changes of ChAT mRNA and AChE mRNA expression in cells induced by Aβ25-35. These results suggested that Gen can protect the mitochondrial membrane and maintain redox state in mitochondria damaged by Aβ25-35.     

Growth and ultrastructure of the marine unicellular alga <Emphasis Type="Italic">Dunaliella salina</Emphasis> (Chlorophyta) after chronic selenium intoxication

The effects of selenium (0.01, 0.5, 1, 5 and 10 mg/liter) on the growth and ultrastructure of the microalga Dunaliella salina were investigated following its transfer into clean water. Selenium concentrations of 5 and 10 mg/liter were toxic to D. salina, and reinoculation of microalga into clean water did not prevent it from total mortality. When reinoculated from medium with 0.01 mg Se/liter, the cell population density of D. salina was restored in 14 days. The number of ultrastructural alterations in cells was the same as in the control, while the excretory activity of microalga between days 4 and 10 of this experiment was higher. Cell population growth of D. salina transferred from 0.5 and 1 mg Se/liter was lower than in the control. No ultrastructural defects were observed in microalga reinoculated from medium with a selenium concentration of 0.5 mg/liter and the excretion level corresponded to that at 0.01 mg/liter. Various types of ultrastructural damage were found in microalga from medium with 1 mg Se/liter, which was previously reported to be threshold for D. salina; however, the number of cell injuries decreased with increasing time in clean medium. Excretory activity was decreased at the beginning of experiment; but after 7 days, it was restored to the control level. Though there were no ultrastructural alterations in microalgal cells from medium with 0.5 mg Se/liter, we assume that they had molecular defects that could inhibit the cell population growth. The study of microalgae following their reinoculation from medium containing toxicants into clean medium can be a useful method for evaluating algal survival after toxic exposure.     

Hypoglycemic effects of exopolysaccharides produced by mycelial cultures of two different mushrooms Tremella fuciformis and Phellinus baumii in ob/ob mice

The anti-diabetic activities of the exopolysaccharides (EPS) produced by submerged mycelial culture of two different mushrooms, Tremella fuciformis and Phellinus baumii, in ob/ob mice were investigated. All the animals were randomly divided into three groups with seven animals in each group: The control group received 0.9% NaCl solution; the diabetic groups were treated with EPS from T. fuciformis (Tf EPS) and P. baumii (Pb EPS) at the level of 200 mg/kg body weight using an oral zoned daily for 52 days. The plasma glucose levels in the EPS-fed mice were substantially reduced by about 52% (Tf EPS) and 32% (Pb EPS), respectively, as compared to control mice. The results of oral glucose tolerance test (OGTT) revealed that both EPS-fed groups significantly increased the glucose disposal after 52 days of EPS treatments. Furthermore, higher food efficiency ratios and reduced blood triglyceride levels were observed in the EPS-treated groups. Because peroxisome proliferator-activated receptor gamma (PPAR-γ) is indeed a key regulator of insulin action, we investigated the expression pattern of adipose tissue PPAR-γ messenger RNA (mRNA) and plasma levels of PPAR-γ. It was revealed that PPAR-γ was significantly activated in response to EPS treatments. The results suggested that both EPS exhibited considerable hypoglycemic effect and improved insulin sensitivity possibly through regulating PPAR-γ-mediated lipid metabolism. Our results indicated that two mushroom-derived EPS might be developed as potential oral hypoglycemic agents or functional foods for the management of non-insulin-dependent diabetes mellitus.     

Study of the dynamics of the electrode plasma in a high-current magnetically insulated transmission line

A series of experiments was carried out in the S-300 facility (3 MA, 0.15 Θ, 100 ns) to study the behavior of a section of a magnetically insulated transmission line (MITL) at current densities of up to 500 MA/cm² and linear current densities of up to 6 MA/cm (i.e., at parameters close to those expected in a fast Z-pinch fusion reactor projected in Sandia National Laboratories). The surface explosion of the ohmically heated MITL electrode is accompanied by the formation of a plasma layer on its surface. This can deteriorate of the transmission properties of the line because the vacuum gap is short-circuited by the plasma produced. The parameters of the electrode plasma and its effect on the MITL transmission properties were investigated experimentally. Possible consequences of the above effects are evaluated, and MHD simulations of the electrode explosion and the subsequent spread of the plasma layer are performed. It is shown that the time during which an MITL segment preserves its transmission properties conforms to the requirements of the conceptual fusion reactor.     

Identification of histone demethylases in Saccharomyces cerevisiae

Based on the prediction that histone lysine demethylases may contain the JmjC domain, we examined the methylation patterns of five knock-out strains (ecm5Delta, gis1Delta, rph1Delta, jhd1Delta, and jhd2Delta (yjr119cDelta)) of Saccharomyces cerevisiae. Mass spectrometry (MS) analyses of histone H3 showed increased modifications in all mutants except ecm5Delta. High-resolution MS was used to unequivocally differentiate trimethylation from acetylation in various tryptic fragments. The relative abundance of specific fragments indicated that histones K36me3 and K4me3 accumulate in rph1Delta and jhd2Delta strains, respectively, whereas both histone K36me2 and K36me accumulate in gis1Delta and jhd1Delta strains. Analyses performed with strains overexpressing the JmjC proteins yielded changes in methylation patterns that were the reverse of those obtained in the complementary knock-out strains. In vitro enzymatic assays confirmed that the JmjC domain of Rph1 specifically demethylates K36me3 primarily and K36me2 secondarily. Overexpression of RPH1 generated a growth defect in response to UV irradiation. The demethylase activity of Rph1 is responsible for the phenotype. Collectively, in addition to Jhd1, our results identified three novel JmjC domain-containing histone demethylases and their sites of action in budding yeast S. cerevisiae. Furthermore, the methodology described here will be useful for identifying histone demethylases and their target sites in other organisms.