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1.
解偶联蛋白及功能研究进展 总被引:5,自引:0,他引:5
解偶联蛋白(ucP,uncoupling protein)是一类线粒体内膜上的载体,属于线粒体载体超家族,可以将H^ 从线粒体内膜渗漏到线粒体基质中,减少ATP的合成并产生热能。已知UCPl在小鼠中有维持体温和能量稳态的重要作用。而UCP2和UCP3可控制活性氧(reactive oxygen species,ROS)产生、调节脂肪酸氧化,并且在肥胖和糖尿病发生中有重要作用。 相似文献
2.
Evaluation and applications of optical cell density probes in mammalian cell bioreactors 总被引:2,自引:0,他引:2
Wu P Ozturk SS Blackie JD Thrift JC Figueroa C Naveh D 《Biotechnology and bioengineering》1995,45(6):495-502
On-line optical cell density probes were implemented to continuously monitor the cell densities in mammalian cell bioreactor and to achieve advanced bioreactor controls. We tested cell density probes from six manufacturers in high cell density bioreactors. When externally calibrated, Aquasant and Ingold backscattering probes produced the most linear probe responses (PR) versus cell density (CD), followed by the ASR and Cerex laser probes. Monitek and Wedgewood transmission probes had lower resolutions. All probes were tested in two murine hybridoma fermentations. Cell densities varied between 1 x 10(6) cells/mL to 20 x 10(6) cells/mL and the bioreactors were operated for 5 to 7 weeks. For our bioreactors, Aquasant, Ingold, ASR, Wedgewood, and Monitek probes gave satisfactory responses. Little fouling was observed with any probe at the end of 2 weeks. Fouling was a possibility after 3 weeks in one bioreactor but its effect can be easily corrected. Cell density control and specific perfusion control of bioreactors based on the Aquasant probe were achieved. Implementation of cell density probe based perfusion control, instead of "step perfusion adjustments" based on manual hemacytometer control, will result in smoother operation, healthier cultures, increased medium delivery efficiency, and reduced operational excursions. (c) 1995 John Wiley & Sons, Inc. 相似文献
3.
目的本实验主要研究冬凌草甲素诱导多发性骨髓瘤发生自噬、凋亡,两者之间的关系以及所涉及的相关机制。方法利用MTT比色法检测冬凌草甲素对多发性骨髓瘤RPMI8226细胞的增殖活性影响;透视电镜观察细胞内凋亡和自噬的形态学改变;TUNEL检测细胞凋亡;分别利用以下技术检测处理后的细胞内的自噬变化:使用QDs605nm-Anti-LC3荧光探针以及免疫荧光技术定位细胞胞内LC3Ⅰ和LC3Ⅱ蛋白,利用western blot免疫印记技术检测Beclin 1蛋白表达水平;利用DCFH-DA探针以及流式细胞术检测细胞胞内ROS水平。结果冬凌草甲素能明显抑制RPMI8226细胞增殖,其抑制作用呈时间、剂量依赖性;冬凌草甲素能同时诱发细胞凋亡、自噬和胞内ROS产生;NAC完全抑制胞内ROS产生后冬凌草甲素诱导的细胞凋亡消失;3-MA抑制自噬后,冬凌草甲素诱导的胞内ROS产生进一步增多,凋亡增多。结论冬凌草甲素能明显抑制RPMI8226细胞增殖;冬凌草甲素同时诱发细胞凋亡和自噬;胞内ROS产生介导冬凌草甲素诱导的凋亡;凋亡为细胞死亡的主要途径,而自噬通过下调胞内ROS产生抑制凋亡。 相似文献
4.
《Bioorganic & medicinal chemistry letters》2020,30(13):127219
The ability to track drugs inside of cells and tumours has been highly valuable in cancer research and diagnosis. Metal complexes add attractive features to fluorescent drugs, such as targeting and specificity, solubility and uptake or photophysical properties. This review focuses on the latest fluorescent metal-based complexes, their cellular targets, photophysical properties and possible anticancer effects. 相似文献
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Oligonucleotide probes specific for simple tandem repeat sequences produce individual specific DNA fingerprints in man and all animal species tested so far. Here 11 different synthetic probes were hybridized to bovine genomic DNAs which had been digested with the restriction endonucleases HinfI, AluI and HaeIII. Two of these probes gave DNA fingerprint patterns which were analysed for three German breeds. Different parameters were calculated, such as the average number of bands per individual or the probability of finding identical fingerprints in two unrelated individuals. The number of polymorphic bands varies from 11 to 23 in the different breeds and the probability of finding the same banding pattern in two unrelated individuals ranges from 1.5 x 10(-7) to 2.4 x 10(-7). Hence this DNA fingerprinting procedure allows precise identification of individuals. It is also a useful additional method for paternity testing in cattle. 相似文献
6.
植物能感受外界环境信息的刺激,并通过复杂的信号转导体系调节植物特定基因的表达,引起相应的生理生化反应,以适应不断变化的环境条件.研究表明,活性氧作为第二信使参与了植物激素信号转导,本文对其在植物激素信号转导中的作用进行综述. 相似文献
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David A. Pink 《Chemistry and physics of lipids》1989,50(3-4):213-236
Recent experimental and theoretical developments concerning perturbing probes are outlined. The fluorescent probe 1,6-diphenyl-1,3,5-hexatriene and nitroxide electron paramagnetic resonance spin labels attached to lipid hydrocarbon chains are taken as the most widely used examples of such probes. The reliability of these probes as indicators of the statics and dynamics of unlabelled lipid hydrocarbon chains is discussed, and the use of such probes in giving information about protein size, protein oligomerization and protein lateral distribution is outlined. Examples are given of studies to determine protein packing in lipid bilayers membranes. 相似文献
9.
本文研究了ROS(Roscovitine)和丁内酯-I(ButyrolactoneI,BL-I)两种细胞周期依赖性激酶抑制剂对山羊卵母细胞减数分裂恢复的抑制作用,并研究了抑制对卵母细胞成熟、激活和发育的影响。结果表明:ROS和BL-I对山羊卵母细胞减数分裂恢复的抑制作用具有浓度依赖性;200μmol/LROS、100μmol/LBL-I、100μmol/LROS+6·25μmol/LBL-I和50μmol/LROS+25μmol/LBL-I都能有效抑制山羊卵母细胞减数分裂的恢复,24h的抑制率分别为78·4%、80·9%、80·3%和77·8%。用ROS和BL-I抑制24h后转为正常培养24h,各处理组卵母细胞的成熟率(分别为81·3%、81·9%、83·2%和85·2%)与对照组(83·0%)无显著差异;成熟卵母细胞的化学激活率分别为93·3%、96·2%、92·5%和90·5%,与对照组(97·8%)无显著差异。然而,抑制处理后卵母细胞的卵裂率和桑椹胚率降低,未能发育到囊胚。ROS和BL-I抑制山羊卵丘扩展,并且转为正常培养后卵丘不能再扩展。ROS和BL-I能够浓度依赖性地抑制山羊卵母细胞减数分裂,二者既可单独,又可降低浓度联合使用,但抑制山羊卵母细胞的浓度远高于牛和猪卵母细胞的;ROS和BL-I抑制24h不影响山羊卵母细胞的成熟和激活能力,但影响卵母细胞的卵丘扩展和胚胎发育能力。因此,山羊卵母细胞减数分裂调控可能比它动物更精细[动物学报52(2):342-348,2006]。 相似文献
10.
F M Hoffmann 《Molecular reproduction and development》1992,32(2):173-178
Many Drosophila genes have now been identified with substantial sequence similarity to vertebrate protooncogenes and growth factors. Some of these have been isolated directly by cross-hybridization with vertebrate probes and some have been recognized in the sequences of genes cloned because of their intiguing mutant phenotypes. An example of a gene isolated for its interesting development functions but with homology to a vertebrate growth factor is the Drosophila decapentaplegic gene (dpp). An example of a Drosophila gene isolated by virtue of its sequence conservation is the vgr/60A gene. Both dpp and vgr/60A are members of the transforming growth factor-beta family and are most similar to the human bone morphogenetic proteins. The regulation of the dpp gene by several different groups of pattern formation genes including the dorsal/ventral group, the terminal group, the segment polarity genes, and the homeotic genes indicates that many events in embryogenesis require the cell to cell communication mediated by the secreted dpp protein. The temporal and spatial pattern of vgr/60A expression differs from that of dpp indicating that it may be regulated by different pattern information genes. The experimental advantages of the Drosophila system should permit a better understanding of the importance of growth factor homologs in specific developmental events, aid in establishing the functional interactions between these regulatory molecules, and identify new genes that are important for the biological functions of growth factors. It is likely that some of the newly identified genes will have vertebrate homologs and the analysis of these may be helpful in studies on vertebrate development and tumor biology. 相似文献
11.
Summary The fluorescence polarization properties of lecithin bilayers stained with 2,6-MANS and 1,8-ANS under applied potential steps have been studied. The fluorescence signal components of both dyes were found to have different sign and relative amplitude, suggesting that 1,8-ANS and 2,6-MANS behave differently when bound to black lipid membranes. In order to determine the location and the extent of rotational brownian motions of the bound chromophores, the experimental data were analyzed by using a simplified physico-mathematical model. According to it 2,6-MANS appears to have a ratio /gt higher than 1,8-ANS ( being the rotational relaxation of in plane rotations and the lifetime of the excited singlet state of the bound molecules), suggesting that the former chromophore is more tightly held inside the bilayers. Furthermore, 2,6-MANS is found to possess the absorption and emission oscillators more closely oriented to the normal of membrane surface, while 1,8-ANS has both oscillators almost near the plane of the bilayers. The results furnish also a fair estimate of the random molecular motion own by the phospholipid molecules at room temperature. The comparison of the present data with those obtained from squid axon membranes confirms the validity of the proposed physical model, yielding a rough estimate of the axon membrane-area covered by integral protein macromolecules. These preliminary results derived from lecithin model membranes suggest that fluorescence polarization techniques can provide valuable informations if applied to study the macromolecular organization of in vitro reconstituted membranes.Abbreviations 2,6-MANS
2-n-methylanilinonaphthalene-6-sulfonate
- 1,8-ANS
1-anilinonaphthalene-8-sulfonate 相似文献
12.
Khac Hong Nguyen Yuanqiang Hao Wansong Chen Yintang Zhang Maotian Xu Minghui Yang You‐Nian Liu 《Luminescence》2018,33(5):816-836
Hydrazine (N2H4) is an important and commonly used chemical reagent for the preparation of textile dyes, pharmaceuticals, pesticides and so on. Despite its widespread industrial applications, hydrazine is highly toxic and exposure to this chemical can cause many symptoms and severe damage to the liver, kidneys, and central nervous system. As a consequence, many efforts have been devoted to the development of fluorescent probes for the selective sensing and/or imaging of N2H4. Although great efforts have been devoted in this area, the large number of important recent studies have not yet been systematically discussed in a review format so far. In this review, we have summarized the recently reported fluorescent N2H4 probes, which are classified into several categories on the basis of the recognition moieties. Moreover, the sensing mechanism and probes designing strategy are also comprehensively discussed on aspects of the unique chemical characteristics of N2H4 and the structures and spectral properties of fluorophores. 相似文献
13.
由于草菇是一种同宗结合的食用真菌,这给草菇的杂交育种带来了一定的困难。本文在建立草菇部分基因文库的基础之上,对草菇的基因文库进行了鉴定。在草菇基因文库中任意抽取72个克隆,利用专一的PCR方法,测出在草菇基因文库中,草菇基因组DNA的平均大小为1156个碱基对。在基因文库中任意选择53个克隆,利用专一的PCR进行DNA扩增以及dig非同位素标记,用于和草菇基因组DNA杂交。在测试的53个克隆中有8%的高度重复序列,36%中度重复序列和56%的低度重复序列。 相似文献
14.
I. Nur J.M. Bove C. Saillard S. Rottem R.M. Whitcomb S. Razin 《FEMS microbiology letters》1986,35(2-3):157-162
Abstract DNA probes were applied to detect spiroplasmas and uncultivable mycoplasma-like organisms (MLOs) in infected plants and insects. The probes consisted of pMC5, a plasmid carrying the RNA genes of Mycoplasma capricolum and pRA1, a plasmid recovered from Spiroplasma citri . Southern blot hybridization of pMC5 with digested DNAs of periwinkle plants infected with S. citri , or with various MLOs, yielded 2 heavy and several weaker bands. The heavy hybridization bands were shown to represent rRNA genes of the plant chloroplasts, indicating significant nucleotide sequence homology between the mycoplasmal rRNA genes and those of plant chloroplasts. Some of the weaker hybridization bands, not revealed in DNA of healthy plants, appeared to represent rRNA gene sequences of the infectious agent. Use of the spiroplasma plasmid as a probe enabled the detection of S. citri in infected plant material and in hemolymph of infected leafhoppers at a high sensitivity level. 相似文献
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16.
The formation of reactive oxygen species (ROS) in intact heart tissue has been assessed by direct ESR measurements, and indirectly by the formation of characteristic tissue products and the protective effects of various antioxidants. The development of lipid soluble esters of compounds which can be trapped intra-cellularly after hydrolysis, and which fluoresce after oxidation, has provided a new tool to investigate ROS in vitro. The utility of 2',7'-dichlorofluorescin diacetate (DCFDA) in isolated-perfused rat heart tissue was investigated in the present study. DCFDA and its deacetylated form were incubated with various levels of hydrogen peroxide or t-butylhydroperoxide (tBOOH). Conversion of the diacetate form to a fluorescent product required 4-5 h with hydrogen peroxide and up to 24 h with tBOOH. In contrast, the deacetylated form fluoresced at 80% of maximum levels 1 h after the addition of 100 mM tBOOH. DCFDA was loaded into heart tissue by infusing for lO min at a final concentration of 10,aM in Krebs-Henseleit bicarbonate buffer. After a lO min washout period, analysis of freeze-clamped heart tissue revealed that the trapped material was readily converted to a fluorescent product by tBOOH, indicating hydrolysis had occurred. Fluorescence of material trapped in heart tissue was approximately 24% of the maximum achieved after oxidation with lOOmM tBOOH. This value decreased to 18 and 13% when the loading and washout periods were from 0 to 20 or 10 to 30min of hypoxia, respectively. Similar results were obtained with the less readily oxidized dicarboxy derivative of DCFDA. Infusion of 500μM tBOOH increased the oxidation of DCFDA in heart tissue from 24 to 31%. These data demonstrate that DCFDA can be loaded into heart tissue and is capable of reflecting relative changes in the oxidative state of this organ. 相似文献
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18.
《Biotechnic & histochemistry》2013,88(1):69-71
AbstractI was invited to this Workshop, because I have published papers on the mechanisms of action of small molecule fluorescent probes used with living cells. The Workshop provided an opportunity to interact with some significant figures in the chemosensor and bioimaging field from across the planet; to spend time with a large, friendly and active group of local investigators and their graduate students; and to take a brief look at a vibrant modern city. Many scientific connections were made and collaborations planned for the Biological Stain Commission and for my own future work. 相似文献
19.
Labile (i.e., free or loosely bound) zinc has the potential to modulate cellular function. Therefore, a flow cytometric assay for the measurement of labile zinc was developed to facilitate the investigation of the physiological roles of zinc. The zinc-sensitive fluorescent probe FluoZin-3 was used to quantify the amount of labile zinc in peripheral blood mononuclear cells isolated from human blood. Maximal fluorescence and autofluorescence of the probe were measured after the addition of zinc in the presence of the ionophore pyrithione, or the membrane-permeant chelator N,N,N',N'-tetrakis-(2-pyridyl-methyl)ethylenediamine, respectively. In this way, the intracellular concentrations of labile zinc in resting cells were estimated to be 0.17 nM in monocytes and 0.35 nM in lymphocytes. The method was successfully employed to monitor phorbol 12-myristate 13-acetate-induced zinc release, which occurred in monocytes but not lymphocytes, and the displacement of protein-bound zinc by the mercury-containing compounds HgCl(2) and thimerosal. Costaining with dyes that emit at higher wavelengths than FluoZin-3 allows multiparameter measurements. Two combinations with other dyes are shown: loading with propidium iodide to measure cellular viability and labeling with antibodies against the surface antigen CD4. This method allows measurement of the concentration of biologically active labile zinc in distinct cell populations. 相似文献
20.
本文报导用地高辛标记核酸探针和分子斑点杂交技术检测轮状病毒基因重配株L-3株活疫苗中残余MA-104细胞DNA含量的方法。提取和纯化MA-104细胞DNA,将其AluI酶切片段用随机引物法引导DNA标记为探针。待检样品抽提核酸后点膜进行斑点杂交。此法灵敏度高,可检出0.14pg的DNA,特异性强,与非同源性DNA无杂交。用此法检测轮状病毒基因重配株L-3株制备的疫苗,MA-104细胞残余DNA含量低于14pg低于WHO限量标准,结果表明此重配株用于研制疫苗是安全的。 相似文献