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171.
We have constructed a luc reporter vector for Dictyostelium discoideum using a 626-bp fragment from the nuclear-associated plasmid Ddp2. The ori from Ddp2 is localized within this fragment and was used to provide an autonomous replication sequence for the reporter vector. This reporter vector was stably retained in D. discoideum AX3K cells without alteration. The vector molecule was also found to exist in relatively low copy number compared to other Dictyostelium vectors in the transformed cells. We demonstrated the utility of this vector as a reporter vector with glycogen synthase promoter/luc fusions of varying sizes.  相似文献   
172.
小麦叶蜂危害的产量损失与防治指标研究   总被引:2,自引:1,他引:1  
卢兆成  沈彩云 《昆虫知识》1994,31(4):206-207
当小麦叶蜂幼虫数量相等时,在较干旱的年份(1988)危害较重;而在气候较湿润的年份(1989)危害较轻。虫量与产量损失成正相关(r=0.9821**),其中以25头/m2幼虫危害的产量损失突增,达显著水平,可以认定为防治指标。  相似文献   
173.
Somatic cell and gene therapy involve the application of biological technologies to an individual patient through the use of living cells which provide a therapeutic benefit (Aliski, 1991). Various forms of cellular and gene therapies are being developed and evaluated in an increasing number of clinical trials for congential and acquired disorders. The potential and progress of these therapeutic applications have resulted in an increasing effort by the Food and Drug Administration (FDA) to develop the regulatory framework under which these therapeutic approaches would insure safety and efficacy, the primary mandate of the FDA.Over five years ago Cellcor began to define the parameters, specifications, and conditions relevant to a Quality Assurance/Quality Control (QA/QC) program that has evolved to insure safety and maximize the efficacy of applications of the company'sex vivo technology, autolymphocyte therapy. Autolymphocyte therapy is an outpatient form of somatic cell immunotherapy based upon the infusion of T cells that have been activatedex vivo using a combination of previously generated autologous cytokines and an anti-CD3 monoclonal antibody.We have been able to demonstrate the feasibility for the safe, controlled, and consistent preparation and delivery of a cellular therapy by application of relevant GMP regulations. This presentation reviews aspects of this program and chronicles our experience which at present amounts to over 4400 infusions for over 700 patients. This program provides a high degree of assurance that a cellular therapy program can be carried out in a multisite mode involving hundreds of patients through the strict adherence to cGMP as set forth in existing regulations. It would be prudent that developers of cellular andex vivo gene therapies establish a similar cell processing and QA/QC infrastructure at an early developmental stage to optimize safety and reproducibility and facilitate regulatory review.  相似文献   
174.
植被生态信息分析中对两(多)组取样集间的相关分析的需求导致了典范相关分析技术的应用和发展。本文对典范相关分析技术的原理、典范参数的生态学意义进行了提示,比较了典范相关分析与PCA之间的差异,产在典范相关分析技术的应用过程中,原始数据的预处理提出了建议。  相似文献   
175.
利用停留仪快速反应动力学方法和自旋捕集ESR技术监测高铁离子自由基和自旋捕捉剂POBN的反应,发现高铁离子自由基本身不被自旋捕捉剂POBN捕捉,但是POBN可以捕捉到停流仪第三相中的OH,可能来自剩余的Fenton试剂或高铁离子自由基的衰变。以含两个双键的不饱和脂肪酸-亚油酸(LH)作为模型化合物,测定高铁离子自由基与亚油酸分子的反应速率。ESR结果表明,高铁离子自由基可能在一定程度上启动了亚油酸体系的脂质过氧化。  相似文献   
176.
Calluses were induced from immature embryos of an indica type rice and finely dispersed cell suspension cultures were initiated from the callus using modified AA medium (S1 medium). The suspension cultures were maintained alternatively (1–2 passages in each medium) in S1 medium and S2 medium, the latter containing KNO3, NH4NO3, proline and glutamine as nitrogen source. Protoplasts of high quality were isolated form suspension cells cultured in S2 medium supplemented with ABA. Embedding the protoplasts in agarose blocks containing NH4NO3-free modified KM8P(PM1) medium and immersing the blocks in NH4NO3-containing modified KM8P(PM3) medium were most effective for obtaining protoplast division and callus formation. The protoplast-derived calluses were precultured in potato extract-aand/or ABA-containing N6(D1, D2 or D3) media and many embryo-like structures were formed. These structures developed into plantlets after being transferred to N6 differentiation (D4) medium. The regenerated plantlets grew into mature plants and beard seeds normally.Abbreviations AA medium amino acids based medium - ABA abscisic acid - BA benzyladenine - 2,4-D 2,4-dichlorophenoxyacetic acid - DF division frequency - IAA indoleacetic acid - KIN kinetin - NAA naphthaleneacetic acid - PE planting efficiency  相似文献   
177.
While the majority of sympathetic neurons are noradrenergic, a minority population are cholinergic. At least one population of cholinergic sympathetic neurons arises during development by a target-dependent conversion from an initial noradrenergic phenotype. Evidence for retrograde specification has been obtained from transplantation studies in which sympathetic neurons that normally express a noradrenergic phenotype throughout life were induced to innervate sweat glands, a target normally innervated by cholinergic sympathetic neurons. This was accomplished by transplanting footpad skin containing sweat gland primordia from early postnatal donor rats to the hairy skin region of host rats. The sympathetic neurons innervating the novel target decreased their expression of noradrenergif traints and developed choline acetyltransferase (ChAT) activity. In addition, many sweat gland-associated fibers acquired acetylcholinesterase (AChE) staining and VIP immunoreactivity. These studies indicated that sympathetic neurons in vivo alter their neurotransmitter phenotype in response to novel envronmental signals and that sweat glands play a critical role in the cholinergic and peptidergic differentiation of the sympathetic neurons that innervate them. The sweat gland-derived cholinergic differentiation factor is distinct from leukemia inhibitory factor and ciliary neurotrophic factor, two well-characterized cytokines that alter the neurotransmitter properties of cultured sympathetic neurons in a similar fashion. Recent studies indicate that anterograde signalling is also important for the establishment of functional synapses in this system. We have found that the production of cholinergic differentiation activity by sweat glands required sympathetic innervation, and the acquisition and maintenance of secretory competence by sweat glands depends upon functional cholinergic innervation. 1994 John Wiley & Sons, Inc.  相似文献   
178.
放射性标记受体分析表明毛喉萜(FSK)可以降低小鼠骨央细胞和腹腔巨噬细胞表面的胰岛素(INS)和粒细胞-巨噬细胞集落刺激因子(GM-CSF)受体数目,而且对GM-CSF的作用有剂量和时间依赖性,经FSK处理的巨噬细胞酸性磷酸酶活性增加,微丝更加舒展。  相似文献   
179.
天花粉蛋白与FMP复合物的晶体结构   总被引:6,自引:1,他引:5  
用浸泡法得到了天花粉蛋白(TCS)与FMP复合物的晶体,在SIMENNSX-200B面探测器系统上收集了一套2.0分辨率的X射线衍射数据。用同晶差值傅立叶法解析了复合物的结构,经X—PLOR程序修正得到了TCS—FMP复合物的分子结构并找出了197个水分子,最后的R因子为0.172,键长和键角的RMS偏差分别为0.015和2.922度。TCS—FMP复合物中,FMP与天花粉蛋白分子有较好的结合,其结合位置正处于根据三维结构和突变体信息推测的N一糖苷酶活性口袋之中。它的类嘌呤环夹在Y70和Y111两个侧链环之间,与Y70环近乎平行,其N7和N6分别与TCS分子的G1094羰基氧和I71的N成氢键,N3靠近R163的侧链,其磷酸根则伸向活性口袋的底部,与E189、E160和R163等残基作用。  相似文献   
180.
本实验观察了活性钙调素(CaM)含量和CaM依赖性蛋白激酶Ⅱ(CaMkinaseⅡ)活性在急性低氧(模拟海拔7000m,5h)和常氧对照大鼠脑子组织中的变化。用流式产胞仪(FACS)所测两组动物脑皮层细胞的CaM,平均荧光强度分别为40.0±4.9和46.1±5.8,急性低氧组明显低于常氧对照组(P<0.05);用同位素液闪计数法所测两组动物皮层脑匀浆提取液中CaMkinaseⅡ活性,分别为184.3±8.1和198.8±9.4pmolPi·min-1·mg-1pro,急性低氧组明显低于常氧对照组(P<0.01)。结果提示CaM和CaMkinaseⅡ对低氧较为敏感,急性低氧时中枢神经细胞结构或功能的紊乱可能与活性CaM的含量减少和CaMkinaseⅡ活性能下降有关。  相似文献   
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