牛凝血酶等电点的初步测定

作为一种新型的速效局部止血药和工具酶,凝血酶在临床和生物学研究中的应用十分广泛,牛血浆是其重要的来源之一。等电点沉淀是提取牛凝血酶首要和关键的步骤,测定其等电点后,再用此法时将得到更纯的凝血酶粗制品。本实验的目的是采用载体两性电解质pH梯度等电聚焦电泳的方法,结合SDS-PAGE测定牛凝血酶的等电点。经双向电泳后,SDS聚丙烯酰胺凝胶中出现了4个清晰的斑点,分别测定它们的分子量和等电点, 其中一个斑点与牛凝血酶B链的分子量一致为32kDa,其等电点为5．19．     

Brain Mitochondrial Dysfunction in Ovariectomized Mice Injected with <Emphasis Type="SmallCaps">d</Emphasis>-Galactose

Our previous studies reveal that long-term exposure of ovariectomized rodents to d-galactose results in pathophysiologic alterations associated with Alzheimer’s disease. The current study was to address whether mitochondrial dysfunction was involved in the pathogenesis of this model. Ovariectomized mice were administered intraperitoneally with d-galctose (100 mg/kg body weight) once a day for 8 weeks. Brain tissues from model mice showed decreases in reduced glutathione level, total antioxidative capabilities, total superoxide dismutase activity and glutathione peroxidase activity but an increase in malondialdehyde level, compared with those from sham-operated plus saline-injected mice. Activities of brain mitochondrial respiratory chain (complex I, II, III and IV) were reduced in model group. In contrast, ATP synthase (F₁F₀-ATPase) activity was not significantly different between the two groups. Moreover, electron microscopy identified ultrastructural impairments of hippocampal mitochondria in model mice. These results demonstrated that brain mitochondrial degeneration caused by oxidative stress participated in the etiology of ovarian hormone deprivation and d-galactose-induced neurodegeneration.     

Combination Treatment with Resveratrol and Sulforaphane Induces Apoptosis in Human U251 Glioma Cells

Resveratrol is a naturally occurring polyphenolic compound highly enriched in grapes, peanuts, red wine, and a variety of food sources. Sulforaphane belongs to the family of isothiocyanates and is highly enriched in cruciferous vegetables. Our previous study showed that resveratrol, when used at high concentrations, inhibited cell proliferation, caused the cell cycle arrest and induced apoptotic cell death in glioma cells. In the current study, we tested the effect of combination treatment with resveratrol and sulforaphane, when both were used at low concentrations, on cell proliferation, migration and death in human U251 glioma cells. Our study shows that combination treatment with resveratrol and sulforaphane inhibits cell proliferation and migration, reduces cell viability, induces lactate dehydrogenase release, decreases pro-survival Akt phosphorylation and increases caspase-3 activation. The use of combination of bioactive food components, such as resveratrol and sulforaphane, may be a viable approach for the treatment of glioma.     

版纳省藤的组织培养

以版纳省藤的萌蘖芽为试材,从取材、材料的处理、外植体的诱导分化、芽的增殖、生根以及影响试管苗形成几个重要因素等方面探讨了版纳省藤组织培养和快速繁殖的技术和方法,获得了生长素与细胞分裂素对芽的诱导分化及芽的增殖最佳配比浓度。以改良MS为基本培养基,在增殖培养基中添加0.5mg·L-1NAA、0.5mg·L-1KT和0.1mg·L-1BA,产生的有效苗最多;在生根培养基中添加1.5～2.0mg·L-1IBA生长素有利于版纳省藤组培苗生根。     

Spatial and temporal extinction dynamics in a freshwater cetacean

Geographical range contraction is a fundamental ecological characteristic of species population decline, but relatively little investigation has been conducted into general trends in the dynamic properties of range collapse. The Yangtze River dolphin or baiji (Lipotes vexillifer), probably the first large mammal species to have become extinct in over 50 years, was believed to have experienced major range collapse during its decline through progressive large-scale range contraction and fragmentation. This range-collapse model is challenged by a new dataset of 406 baiji last-sighting records collected from across the baiji''s historical range during an interview survey of Yangtze fishing communities. Although baiji regional abundance may have varied across its range, analyses of the extensive new sighting series provide comprehensive evidence that baiji population decline was not associated with any major contraction in geographical range across the middle–lower Yangtze drainage, even in the decade immediately before probable global extinction of the species. Extinction risk in baiji was therefore seemingly not related to evidence of range collapse. Baiji apparently underwent large-scale periodic and seasonal movements across their range, and we propose that range contraction and fragmentation may not be general biogeographic characteristics for declining populations of mobile species in connected landscapes.     

宁夏革螨三新种记述(蜱螨亚纲,革螨股)

记述寄螨科Parasitidae1新种,六盘山钝革螨Amblygamasus liupanshanensis Bai,Yan et Wu,sp.nov.,宽寄螨科Euryparasitidae 1新种,邓氏宽寄螨Euryparasitus tengkuofani Bai,Yan et Wei,sp.nov.和维螨科Veigaiaidae 1新种,陈氏维螨Veigaia chenbaifangi Bai,Yan et Qi,sp.nov.,标本采自宁夏六盘山自然保护区,模式标本保存于军事医学科学院微生物流行病研究所昆虫标本馆,北京。     

Effect of bone char addition on the fractionation and bio-accessibility of Pb and Zn in combined contaminated soil

Effect of bone char addition on the fractionation and bio-accessibility of lead (Pb) and Zinc (Zn) in combined contaminated soil was studied by batch soil column incubation experiment. Four treatments were designed: control (without bone char), 1%, 2% and 5% bone char addition (by weight). The results showed that all treatments with bone char addition could significantly decrease the concentration of HOAc extractable Pb (P < 0.05). Compared with the control the concentration of HOAc extractable Pb was decreased by 66.85%, 83.69% and 97.40%, respectively, in 1%, 2% and 5% bone char amended soils after 3 months incubation. The treatment with 5% bone char addition significantly decreased (P < 0.05) the concentration of HOAc extractable Zn by 47.80%, 43.63% and 41.35%, respectively, after 1, 2 and 3 months incubation. All treatments, including 1%, 2% and 5% bone char addition, significantly decreased (P < 0.05) the concentration of bio-accessible Pb after 3 months incubation, however, only the treatment with 5% bone char addition significantly decreased (P < 0.05) the concentration of bio-accessible Zn after 3 months incubation. The results highlighted the potential of bone char amendments to reduce the bioavailability of Pb and Zn in contaminated soil.     

长白山阔叶红松林灌木物种组成、结构和空间分布

以长白山阔叶红松林25 hm2动态监测样地为平台,基于样地内600个5 m×5 m样方的调查数据,对灌木的物种组成、基本特征、结构和空间分布等进行了初步研究.结果表明:共调查到18种灌木,以东北山梅花、毛榛和簇毛槭为主要优势种;调查样方共记录灌木个体6435个和灌木枝干11369个,其中东北山梅花的个体数和枝干数最多,分别占总数的40.6%和33.4%;不同灌木的成丛率、每丛枝干的数量、冠幅和基径均存在明显的差异;不同灌木在高度上有较为明显的分化,灌木群落成层现象明显;优势种东北山梅花分布广泛,而珍珠梅、石蚕叶绣线菊、柳叶绣线菊和瘤枝卫矛的空间分布则呈现出较明显的异质性.     

褪黑素对胃癌小鼠Survivin表达的影响

目的探讨褪黑素对胃癌小鼠Survivin表达的影响。方法选用6-8周龄SPF级615近交系小鼠,接种胃癌MFC细胞,建立荷瘤小鼠模型并给予不同剂量的褪黑素处理,用Real-time PCR法和Western blot法检测肿瘤组织中Survivin mRNA和蛋白的表达。结果 Real-time PCR和Western-blot检测显示褪黑素各干预组小鼠胃癌组织中Survivin基因的表达水平下降且随褪黑素剂量增大而降低。结论褪黑素具有下调survivin的作用。褪黑素降低survivin的表达,可能是褪黑素抑制肿瘤的作用机制之一。     

温度与pH值对长江水系产超广谱β-内酰胺酶大肠埃希菌耐药基因转移影响分析

研究温度和pH值对长江水系中产超广谱β-内酰胺酶(Extended-Spectrum β-Lactamases,ESBL)大肠埃希菌(Escherichia coli)耐药基因转移影响规律,为今后介水疾病的预防与控制提供理论依据。采用滤膜法分离、梅里埃微生物分析系统鉴定菌株;将由长江水系分离出的产ESBL大肠埃希菌与大肠埃希菌NK5449进行接合,观察不同温度和pH值条件下接合频率变化情况;用纸片扩散法测定耐药谱;用PCR方法分析产ESBL供体菌与转移接合子β-内酰胺酶编码基因(bla),并对供、受体菌及转移接合子进行随机扩增多态性分析,判别转移接合子与供、受体菌的同源性。温度和pH值对产ESBL大肠埃希菌耐药基因水平转移影响明显,发生接合最适宜的pH值为7.1。温度对接合频率的影响具有双重性,相同条件下,某些大肠埃希菌接合频率随环境温度的降低率急剧下降,但某些大肠埃希菌的接合频率随环境温度下降有所上升。温度和pH值对产ESBL大肠埃希菌接合频率有重要影响。