石蜡油对离子注入动物细胞真空环境的保护效应初探

利用石蜡油的高效护水功能进行动物细胞(HeLa细胞)的真空及注入保护,研究了不同的预处理时间对细胞活性的影响,并将石蜡油浸泡细胞2 m in~6 m in选为最佳保护时间。当细胞经过2 m in~6 m in的预处理后再进行真空、注入,结果显示成活率大幅度提高。     

定向进化提高灰盖鬼伞过氧化物酶染织废水脱色效率

【目的】获得染织废水脱色能力增强的灰盖鬼伞过氧化物酶。【方法】使用基因合成及定点突变平台合成突变灰盖鬼伞过氧化物酶基因CIPmt4(I49S、V53A、M166F和M242I),并调整密码子至毕赤酵母偏好性。以CIPmt4为模板进行定向进化,经过三轮易错PCR和高通量筛选得到一个酶学性质显著改善的突变体(CIPmt5)。通过3D建模和分子动力学模拟分析蛋白的结构及热稳定性,并进一步研究CIPmt5和野生型CIP对刚果红、氨基黑、甲基橙、次甲基蓝、苯胺蓝、结晶紫、溴酚蓝共7种染料的脱色能力。【结果】序列分析显示该突变体积累了I49S、V53A、T121A、M166F和Y272F共5个氨基酸突变,与野生型灰盖鬼伞过氧化物酶相比,以ABTS为底物酶活性是野生型的2.01倍(24.44 U/mg),最适反应p H由5.0提高到6.5,最适反应温度由25°C提高到45°C。除次甲基蓝外对其它染料脱色的最适p H都往中、碱性方向偏移,脱色率普遍高于野生型。模型分析显示CIPmt5活性中心更开放,热稳定性增强。【结论】突变体酶CIPmt5能够更好地替代野生型灰盖鬼伞过氧化物酶应用于染织业染料脱色、化工废水和染织废水的生物修复。     

Human alpha-galactosidase A: characterization of the N-linked oligosaccharides on the intracellular and secreted glycoforms overexpressed by Chinese hamster ovary cells

Human alpha-galactosidase A (alpha-Gal A) is the lysosomal glycohydrolase that cleaves the terminal alpha-galactosyl moieties of various glycoconjugates. Overexpression of the enzyme in Chinese hamster ovary (CHO) cells results in high intracellular enzyme accumulation and the selective secretion of active enzyme. Structural analysis of the N -linked oligosaccharides of the intracellular and secreted glycoforms revealed that the secreted enzyme's oligosaccharides were remarkably heterogeneous, having high mannose (63%), complex (30%), and hybrid (5%) structures. The major high mannose oligosaccharides were Man5-7GlcNAc2 species. Approximately 40% of the high mannose and 30% of the hybrid oligosaccharides had phosphate monoester groups. The complex oligosaccharides were mono-, bi- , 2,4-tri-, 2,6-tri- and tetraantennary with or without core-region fucose, many of which had incomplete outer chains. Approximately 30% of the complex oligosaccharides were mono- or disialylated. Sialic acids were mostly N -acetylneuraminic acid and occurred exclusively in alpha2, 3-linkage. In contrast, the intracellular enzyme had only small amounts of complex chains (7.7%) and had predominantly high mannose oligosaccharides (92%), mostly Man5GlcNAc2 and smaller species, of which only 3% were phosphorylated. The complex oligosaccharides were fucosylated and had the same antennary structures as the secreted enzyme. Although most had mature outer chains, none were sialylated. Thus, the overexpression of human alpha-Gal A in CHO cells resulted in different oligosaccharide structures on the secreted and intracellular glycoforms, the highly heterogeneous secreted forms presumably due to the high level expression and impaired glycosylation in the trans- Golgi network, and the predominately Man5-7GlcNAc2 cellular glycoforms resulting from carbohydrate trimming in the lysosome.      

大熊猫胃肠道内分泌细胞分布型的研究

本文用ＰＡＰ法对３只大熊猫胃底,幽门腺区、十二脂肠,空肠,回肠、结肠和直肠的五羟色胺,生长抑素,胃素,胆囊收缩囊,神经降压素、胃动素、抑胃多肽、胰高血糖素、血管活性肠肽和内啡肽的ＩＲ细胞进行了研究。结果表明,大熊猫胃肠道粘膜上皮中具有前八种ＩＲ细胞。对７年龄个体胃肠各段相对数量的比较和各段内分布情况的观察结果表明,除五羟色胺ＩＲ细胞在空肠分布较多外,大多数种类的ＩＲ细胞集中分布于幽门区和十二指肠,     

Histological and immunohistochemical studies of the structure of lymph nodes in Kilis goats

Ten healthy adult Kilis goat mesenteric lymph nodes were used to examine the general structure of lymph nodes, lymphocytes, plasma cells, reticular cells and reticular fibers using histological methods. We also detected T lymphocytes using anti-CD3 [SP7], anti-CD4 [74-12-4], mouse anti-bovine CD4 [CC30] and mouse anti-bovine CD8 [CC63] monoclonal antibodies (mAb); and B lymphocytes using anti-CD79a [HM57] mAb, macrophages using anti-macrophage [MAC387] mAb and follicular dendritic cells using anti-S100 polyclonal antibody (pAb). The distribution of these cells also was studied. Although the primer antibodies we used for CD3, CD8, CD79a, MAC387 and S100 worked well, the primer antibodies for CD4 were ineffective for paraffin embedded goat lymph nodes.     

Quantitative trait loci analysis of individual and total isoflavone contents in soybean seeds

Soybean isoflavones play diverse roles in human health, including cancers, osteoporosis, heart disease, menopausal symptoms and pabulums. The objective of this study was to identify the quantitative trait loci (QTL) associated with the isoflavones daidzein (DC), genistein (GeC), glycitein (GlC) and total isoflavone contents (TIC) in soybean seeds. A population of 184 F_21:0 recombinant inbred lines derived from a ‘Xiaoheidou’ בGR8836’ cross was planted in pot and field conditions to evaluate soybean isoflavones. Twenty-one QTL were detected by composite interval mapping. Several QTL were associated with the traits for DC, GeC, GlC and TIC only. QDGeGlTIC4_1 and QDGlTIC12_1 are reported first in this study and were associated with the DC, GeC, GlC and TIC traits simultaneously. The QTL identified have potential value for marker-assisted selection to develop soybean varieties with desirable isoflavone content.     

榕树须活性部位的成分研究

采用硅胶柱层析色谱和重结晶方法对榕树须95%乙醇提取物进行分离,得到8化合物,通过理化性质和波谱技术分别鉴定为:α-香树脂醇乙酸酯(1),羽扇豆醇乙酸酯(2),木栓酮(3),木栓醇(4),正三十五烷醇(5),白桦酯酸(6),β-谷甾醇(7)和豆甾-4-烯-6β-羟基-3-酮(8)。除化合物6外,其余化合物均为首次从该植物中分离得到。     

Isolation and characterization of monoclonal antibodies which neutralize human metapneumovirus in vitro and in vivo

Human metapneumovirus (hMPV) is a recently described member of the Paramyxoviridae family/Pneumovirinae subfamily and shares many common features with respiratory syncytial virus (RSV), another member of the same subfamily. hMPV causes respiratory tract illnesses that, similar to human RSV, occur predominantly during the winter months and have symptoms that range from mild to severe cough, bronchiolitis, and pneumonia. Like RSV, the hMPV virus can be subdivided into two genetic subgroups, A and B. With RSV, a single monoclonal antibody directed at the fusion (F) protein can prevent severe lower respiratory tract RSV infection. Because of the high level of sequence conservation of the F protein across all the hMPV subgroups, this protein is likely to be the preferred antigenic target for the generation of cross-subgroup neutralizing antibodies. Here we describe the generation of a panel of neutralizing monoclonal antibodies that bind to the hMPV F protein. A subset of these antibodies has the ability to neutralize prototypic strains of both the A and B hMPV subgroups in vitro. Two of these antibodies exhibited high-affinity binding to the F protein and were shown to protect hamsters against infection with hMPV. The data suggest that a monoclonal antibody could be used prophylactically to prevent lower respiratory tract disease caused by hMPV.