Characteristics and antifungal activity of a chitin binding protein from Ginkgo biloba

An antifungal peptide from leaves of Ginkgo biloba, designated GAFP, has been isolated. Its molecular mass of 4244.0 Da was determined by mass spectrometry. The complete amino acid sequence was obtained from automated Edman degradation. GAFP exhibited antifungal activity towards Pellicularia sasakii Ito, Alternaria alternata (Fries) Keissler, Fusarium graminearum Schw. and Fusarium moniliforme. Its activities differed among various fungi. GAFP could also cause increased hyphal membrane permeabilization and a rapid alkalization of the medium when applied at 100 microgram/ml to Pellicularia sasakii Ito hyphae. The amino acid sequence of GAFP shows characteristics of the cysteine/glycine-rich chitin binding domain of many chitin binding proteins. The cysteine residues are well conserved.     

Novel tumor-associated antigen of hepatocellular carcinoma defined by monoclonal antibody E4-65

A monoclonal antibody, E4-65, produced by immunizing mice with SMMC-7721 cells, a human hepatocellular carcinoma (HCC) cell line, was used to identify and characterize an unreported HCC-associated antigen. Indirect immunofluorescence studies showed that E4-65 antibody reacted with five out of eight HCC cell lines, but not with 10 non-HCC tumor cell lines or a normal liver cell line. Using immunohistochemical examination, E4-65 antigen was detected on the cell membranes and in the cytoplasm of human liver tumor tissues, but was not found in most other tumors, or normal adult or fetal tissues, except for a weakly positive reaction in tissues of the digestive system. Western blot analysis showed that E4-65 antibody bound to a 45 kDa protein in the human HCC cell line and tissue lysates. Enzyme treatment and lectin blotting did not detect the carbohydrate chain in E4-65 antigen. This HCC-associated protein represents a potentially useful target for diagnoses and immunotherapy of human HCC.     

亚硒酸钠对四氯化碳损伤草鱼肝原代细胞与肝组织的保护作用

不同浓度四氯化碳（ＣＣｌ４）对草鱼肝原代细胞的损伤实验中,ＣＣｌ４浓度为１０μｌ／ｍｌ可引起细胞血清中丙氨酸氨基转移酶（ＡＬＴ）、天门冬氨酸氨基转移酶（ＡＳＴ）、乳酸脱氢酶（ＬＤＨ）逸出量与细胞破损率显著增高,培养液中添加亚硒酸钠（Ｎａ２ＳｅＯ３）０．２μｇ／ｍｌ,则可降低ＡＬＴ、ＡＳＴ、ＬＤＨ的逸出量,减轻细胞破损程度。Ｎａ２ＳｅＯ３保护实验中,Ｎａ２ＳｅＯ２＋ＣＣｌ４组预先腹腔注射（ｉｐ）０．１ｍｇ／ｋｇ．ｂｗ连续三日,末次ｉｐＣＣｌ４混合液１ｍｌ／ｋｇ．ｂｗ,２４ｈ内肝组织超氧物歧化酶（ＳＯＤ）相对活性比ＣＣｌ４组提高达９１．５％,第七日仍提高达５４．５％,与对照组的水平基本接近;血清中丙氨酸氨基转氨酶（ＡＬＴ）水平逐渐降低。本实验还观察到Ｎａ２ＳｅＯ３可引起肝脂质过氧化物显著降低,肝微粒体蛋白含量与细胞色素Ｐ—４５０活性升高;组织切片观察显示肝组织损伤程度减轻,７２ｈ后细胞核增多。表明Ｎａ２ＳｅＯ３可提高草鱼肝清除自由基能力,增强肝脏解毒功能。     

低氧对巨噬细胞分泌TNF-α和IL-6的影响及其机制

目的:观察低氧对巨噬细胞(Mφ)前炎症因子TNF-α和IL-6分泌的影响及其机制.方法:收集分离小鼠腹腔Mφ,建立Mφ的低氧(1% O2,5%CO2)培养模型,并用非特异性酯酶染色法进行鉴定;ELISA法检测上清液中TNF-α和IL-6的含量;RT-PCR法检测TNF-α和IL-6的转录物水平;用Western blot法检测Mφ核内NF-κB的激活量;通过在培养液中加入氢化可的松(5 mg/L),观察低氧时TNF-α和IL-6分泌量的变化.结果:TNF-α和IL-6分泌量在低氧12 h时明显增加(P＜0.01);低氧6 h时,TNF-α mRNA和IL-6 mRNA表达量明显高于对照组(P＜0.01);M中核内NF-κB的激活量在低氧2 h时明显增高(P＜0.05),低氧5 h内持续存在;而当培养液中加入氢化可的松抑制NF-κB活性后,TNF-α和IL-6的分泌水平无明显变化.结论:低氧可通过核转录因子NF-κB途径促进细胞因子TNF-α和IL-6基因的表达和分泌.     

Two Novel Bacteriophages of Thermophilic Bacteria Isolated from Deep-Sea Hydrothermal Fields

Bacteriophages of thermophiles are of great interest due to their important roles in many biogeochemical and ecological processes. However, no virion has been isolated from deep-sea thermophilic bacteria to date. In this investigation, two lytic bacteriophages (termed Bacillus virus W1 and Geobacillus virus E1) of thermophilic bacteria were purified from deep-sea hydrothermal fields in the Pacific for the first time. Bacillus virus W1 (BVW1) obtained from Bacillus sp. w13, had a long tail (300nm in length and 15 nm in width) and a hexagonal head (70 nm in diameter). Another virus, Geobacillus virus E1 (GVE1) from Geobacillus sp. E26323, was a typical Siphoviridae phage with a hexagonal head (130 nm in diameter) and a tail (180 nm in length and 30 nm in width). The two phages contained double-stranded genomic DNAs. The genomic DNA sizes of BVW1 and GVE1 were estimated to be about 18 and 41 kb, respectively. Based on SDS-PAGE of purified virions, six major proteins were revealed for each of the two phages. The findings in our study will be very helpful to realize the effect of virus on thermophiles as well as the communities in deep-sea hydrothermal fields.     

端粒酶RNA组分的反义寡核苷酸对BEL—7404人肝癌细胞端粒酶活性的抑制和细胞凋亡的诱导

Telomerase activity was detected in all of four human hepatoma cells but absent in normal liver tissue. Telomerase activity of BEL-7404 human hepatoma cells was inhibited effectively by antisense oligonucleotide to telomerase RNA component at final concentration of 1 mumol/L, whereas sense and missense oligonucleotides have no effects on its activity. The inhibition of telomerase activity was weakened, as the concentration of antisense oligonucleotide decreased. Treating BEL-7404 human hepatoma cells 96 hours continuously by the antisense oligomers at final concentration of 5 mumol/L, the morphology of treated cells changed and apoptosis percent of the cells increased markedly.     

微生物NAD合成酶及其抑制剂的研究进展

NAD(P)生物代谢在能量代谢,维持氧化还原稳态以及调节细胞寿命等许多细胞进程中有重要作用。因此,NAD生物合成途径的关键酶的抑制剂就成为备受关注的候选新药,如NAD合成酶抑制剂。本文对微生物中的NAD合成酶的催化活性特征,晶体结构,调控因子以及基于晶体结构的抑制剂设计方面进行了综述,以期为基于NAD的治疗领域打开新的思路。     

干预措施对噪声污染大鼠脑组织基因表达及去甲肾上腺素水平的影响

为了探索干预措施对噪声污染大鼠脑组织基因表达水平的影响, 将50只SPF级Wistar大鼠随机分为空白对照组、噪声污染组(分为30、60、80 dB三个组)、干预组(利血平+80 dB), 每组10只动物。每天刺激1次, 每次刺激30 min, 连续刺激15 d。第16天解剖出脑组织用酶联免疫吸附法(ELISA)检测基因表达水平。结果发现, 噪声污染组大脑前额叶皮质(PFC)和海马(Hipp)组织中去甲肾上腺素(noradrenaline,NA)水平比对照组分别升高了22.87%、50.35%、94.65%和 12.00%、31.76%、61.83%; 干预组NA水平比对照组分别降低了33.66%和52.06%; 去甲肾上腺素转运蛋白(noradrenaline transporter, NAt)水平比对照组分别升高了22.87%、50.35%、94.65%和12.00%、31.76%、61.83%, 干预组NAt水平比对照组分别降低了33.66%和52.06%; 脑源性神经营养因子(brain derived neurotrophic factor, BDNF)水平比对照组分别升高了24.87%、39.27%、67.41%和44.97%、80.81%、95.84%, 干预组BDNF水平比对照组分别升高了16.36%和14.34%, 升高程度明显低于噪声污染组; 酪氨酸激酶受体B(Tyrosine kinase B, TrkB)水平比对照组分别升高了32.64%、59.95%、82.64%和31.02%、57.31%、80.23%, 干预组TrkB水平比对照组分别升高了4.75%和10.52%, 升高程度明显低于噪声污染组。结果显示, 噪声污染使动物体内去甲肾上腺素等水平升高, 去甲肾上腺素是噪声污染引起组织器官损伤的主要因素, 脑源性神经营养因子和酪氨酸激酶受体B防止神经元受损死亡, 改善神经元的病理状态, 利血平使去甲肾上腺素耗竭, 保护组织器官免受噪声污染的损伤。     

Transforming Activity of a Novel Mutant of HPV16 E6E7 Fusion Gene

An optimized recombinant HPV16 E6E7 fusion gene (HPV16 ofE6E7) was constructed according to codon usage for mammalian cell expression, and a mutant of HPV16 ofE6E7 fusion gene (HPV16 omfE6E7) was generated by site-directed mutagenesis at L57G, C113R for the E6 protein and C24G, E26G for the E7 protein for HPV16 ofE6E7 [patent pending (CN 101100672)]. The HPV16 omfE6E7 gene constructed in this work not only lost the transformation capability to NIH 3T3 cells and tumorigenicity in SCID mice, but also maintain...     

我国若干地区蜡样芽孢杆菌723株噬菌体分型的初步报告

四年来,作者由水中获取蜡样芽孢杆菌噬菌体13株,旨在试作噬菌体分型。待检菌株共723株,由国内16个地区提供(其中食物中毒株121株;食品株602株)。分型结果显示:C29、C30、C24、C27、C19和A_4等型别占优势。中毒株