盐胁迫诱导的植物细胞凋亡--植物抗盐的可能生理机制

近来的研究表明,一定条件的盐胁迫可导致植物细胞程序性死亡。本文利用DNALaddering、石蜡切片原位检测以及染色体涂片原位检测,从组织、细胞以及DNA等多个方面对盐胁迫下的玉米、水稻和烟草根尖细胞死亡作了研究,形态特别是生化方面的证据表明盐胁迫诱导的植物细胞凋亡可能在植物界具有一定的普遍性。但各个物种之间有一定差异。本实验结果对盐胁迫下的植物生理机制提供了新的研究思路。同时,我们还对基于染色体制片和石蜡切片的原位检测方法进行了比较和讨论。我们认为,基于染色体制片的原位标记技术适合于定性和定量检测单个细胞的凋亡,具有一些石蜡切片所不可及的优点。     

痘苗病毒的复制与中间纤维的关系

应用细胞选择性抽提与核酸点杂交技术业示,痘苗病毒的DNA 存在于中间纤维-核纤层-核基质组分(IF-L-NM)中。进而用DGD包埋-去包埋和电镜放射自显影技术相结合,结果表明新合成的病毒的DNA 优先结合在中间纤维上。在此基础上采用DNA 与蛋白质的体外吸附杂交实验,进一步说明痘苗病毒DNA序列与中间纤维及某些核基质蛋白质有较高的亲和性。     

旋毛虫基因重组抗原的纯化

根据旋毛虫基因重组抗原蛋白的特点,筛选出裂解处理工程菌菌体的方法,并探索了用ＳｅｐｈａｃｒｙｌＳ－３００（ＨＲ）柱层析纯化重组蛋白的程序。用本法处理和纯化后,重组蛋白的纯度可达９０％以上。所纯化的三种重组抗原蛋白均能与猪旋毛虫病血清发生特异性反应而不与正常猪血清和猪囊虫病血清反应,其中以重组蛋白ＲＰ３４的特异性最强,ＲＰ３７较弱,ＲＰ４６介于两者之间。研究结果表明,本纯化方法易于操作、设备简单和特异性蛋白回收率高,是处理和纯化旋毛虫基因重组抗原的最佳程序。     

A silver-staining technique for detecting minute quantities of proteins on nitrocellulose paper: retention of antigenicity of stained proteins

A method using a silver-staining procedure to detect minute quantities of proteins on nitrocellulose paper is described. The technique is sensitive enough to detect nanogram quantities of proteins resolved on sodium dodecyl sulfate-polyacrylamide gels and then transferred to nitrocellulose paper by the electrotransfer technique. After the staining procedures, the proteins are shown to retain their antigenic properties.     

Simple derivation of the function of genetic information and correction of the proof

The problem of predicting time to extinction in stochastics population models is approached in two ways. First, a finite Markov chain approximation is used to give the distribution of time to extinction and shown to predict simulation results accurately. Second, an approximate numerical integration technique is found to give good relative predictions of persistence using much less computer time. The relevance of the two approaches to real problems is discussed.     

Perception of simulated stars by Eptesicus fuscus (Vespertilionidae): A potential navigational mechanism

Three big borwn bats, Eptesicus fuscus, were trained, using a behavioural discrimination technique, to respond to a point light source. Stimulus presentations were separated by randomly determined, variable time sequences. The star simulator, 100 cm from the subject, approximated the spectral energies of the blue and white star classes for intensities in the scotopic visual range. The data indicate a stellar threshold level of +3.2 magnitudes, suggesting that stars could serve as navigational cues for these bats.     

Direct visualization of collagens and procollagens in polyacrylamide gels.

This report describes a procedure that results in the rapid visual identification of collagens and procollagens in polyacrylamide gels. The technique results in a pink stain for collagenous proteins and a blue stain for all other proteins. The color difference has been evaluated spectrophotometrically. The absorbance maxima for collagen-Coomassie blue R250 complexes in gels is 520–535 nm, and the maxima for all other protein-Coomassie blue R250 complexes that we tested is 550–560 nm. This technique will facilitate the identification of collagenous proteins in complex mixtures of proteins derived from cell membranes, whole cell extracts, conditioned media, and extracellular matrices. We use the technique to detect procollagens in human diploid fibroblast conditioned media. The technique is simple, relatively rapid, has utility for proteins extracted by a variety of methods, and is applicable to all polyacrylamide gel systems in general use.     

留置导尿生理性自动计量排放器的研制和临床应用

为使截瘫等病人的膀胱仍能象在生理情况下贮存和排放尿液,有效的训练膀胱,并自动准确统计尿量。利用传感、微电脑技术研制出一留置导尿生理性自动计量排放器,初步用于临床50例病人的观察,减少人力,方便护理,效果满意。此仪器还可用于大手术术中术后、及休克等病人的尿量监护。可减少逆行性尿路感染,可推广使用。现报告如下:     

深圳市高速公路边坡和采石场植被恢复技术

因此 ,基于高速公路边坡和采石场没有植被生长的基本条件 ,治理难度大 ,迫切需要进一步开展采石场近自然 (接近自然植物群落 )生态修复技术的试验研究。本文系统分析总结了近年来深圳市在高速公路边坡、采石场植被恢复过程中 ,所采用的种子喷射、植物袋、植物砌块等主要技术及其存在的问题 ,为进一步开展高速公路边坡、采石场近自然生态修复技术的开发研究提供参考     

Measurements of DNA and RNA in mammary gland homogenates by the ethidium bromide technique.

A rapid method of determining simultaneously DNA and RNA in mammary gland homogenates using the ethidium bromide technique is discussed. The method utilizes a quantitative extraction of DNA and RNA with 2.0m sodium chloride, SDS, and EDTA at pH 8.0. Assays of mammary gland RNA and DNA using previously published methods were compared with determinations using the ethidium bromide technique. While the fluorescence method gave lower values for RNA when compared to those obtained using the orcinol or absorbancy ratio (OD 260nm/280nm), DNA measurements agreed well with the values determined by the diphenylamine technique. Extinction coefficient data for total mammary gland RNA isolated using a modified phenol extraction procedure are also presented.     

Application of Forster resonance energy transfer to interactions between cell or lipid vesicle surfaces.

Calculations are presented which demonstrate the efficacy of a Förster resonance energy transfer technique to measurement of the aggregation of cells and lipid vesicles.     

Application of conventional and FPG staining for the analysis of chromosome aberrations induced by low levels of dose in human lymphocytes

Human peripheral lymphocytes were irradiated with 0.05-0.5 Gy of 220 keV X-rays. After application of either a conventional or the fluorescence plus Giemsa (FPG) staining technique, the dose response for dicentrics and acentrics was studied. The analysis of exclusively first-division cells (M1), carried out by the FPG method, revealed significantly higher aberration yields as compared with the results of the conventional method. The data from M1 cells support the assumption of a linear dose response for both dicentrics and acentrics. The results are discussed with regard to the application of chromosome analyses for a cytogenetic dosimetry after exposure to low levels of ionizing radiation.     

Scanning molecular sieve chromatography of interacting protein systems. II. Determination of large zone transport parameters by the difference profile method at low solute concentration

The experimental determination of difference profiles for the study of large zone transport processes by scanning molecular sieve chromatography is described. Using the difference profile method, the progesterone-induced purple glycoprotein of the porcine uterus was found to exist as monomeric units in high ionic environment, with a partition coefficient of 0.269, partition cross-section of 0.488, partition radius of 25 A and a molecular weight of 33500 g mole . The technique was further applied in examining the association-dissociation properties of oxyhemoglobin. In a high tonic environment, the partition coefficient was found to be 0.365 for dimer and the partition cross-section, 0.419; for the tetramer in low ionic strength solution, the partition coefficient was 0.275 and the partition cross-section 0.377, with a dissociation constant of 1.03 x 10(-6) mole/1. This new technique should prove applicable in (1) readily locating the centroid positions of transport boundary profiles at the lowest practicable protein concentration limits, (2) demonstrating the characteristic boundary shape and concentration-dependent centroid position for an interacting solute, (3) determining the axial dispersion coefficient characteristic of solute turbulence within the gel matrix, and (4) distinguishing the boundary between low and high ionic strength solvent phases in the gel column.     

Application of radiation hybrid in gene mapping

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微卫星多态性检测技术及其在保护遗传学中的应用

微卫星是一种新型的分子遗传标记,具有只需极少量样品即可进行PCR扩增等优点,使之极其适合于保护遗传化学研究。阐释了微卫星的结构、微卫星多态检测技术的原理,简要论述了微卫生多态检测技术的优点及其应用,并介绍了一种分离动物微卫星位点的富集方法。     

Methods for quantitative determination of ethylene in aqueous solutions for biological studies

Abstract. In many plant physiological studies, quantitative determination of ethylene in aqueous solutions is necessary. We describe two methods for such measurements based on vacuum extraction, or on stripping ethylene from solution with the carrier gas of a gas chromatograph. The gas-stripping technique is limited by the small sample volumes that can be used, whereas the vacuum extraction technique can accommodate much larger volumes and is useful when the ethylene concentration in the solution is very low. The use of these techniques will facilitate the treatment of submerged plant tissues with known amounts of ethylene, and also the quantitative determination of ethylene from tissues grown in either static or continuous flow liquid cultures.     

Biophysical meanings of orientation and deformation of RBCs in shear flow field of low viscosity with new Ektacytometry

ＥｋｔａｃｙｔｏｍｅｔｒｙｍｅａｓｕｒｉｎｇＲＢＣｄｅｆｏｒｍａｂｉｌｉｔｙｗａｓｆｉｒｓｔｄｅｖｅｌｏｐｅｄｂｙＢｅｓｓｉｓｅｔａｌ.ｉｎ1975[1].Ｔｈｉｓｔｅｃｈｎｉｑｕｅｈａｓｂｅｅｎｗｏｒｌｄｗｉｄｅａｃｃｅｐｔｅｄｎｏｗ.Ｈｏｗｅｖｅｒ,ｔｈｅｍｅａｎｉｎｇｏｆｄｅｆｏｒｍａｔｉｏｎｉｎｄｅｘ(ＤＩ)ｍｅａｓｕｒｅｄｗｉｔｈｔｈｉｓｍｅｔｈｏｄｉｓｓｔｉｌｌｗｏｒｔｈｓｔｕｄｙｉｎｇ.ＴｈｅｔｒａｄｉｔｉｏｎａｌＥｋｔａｃｙｔｏｍｅｔｒｙｕｓｅｓｓｕｓｐｅｎｄｉｎｇｍｅｄｉｕｍｏｆｈｉｇｈｖｉ…     

A Simplified Technique for Detection of Paclobutrazol in Plant Sap Extracts, Using HPLC

The tree growth regulator paclobutrazol (PAC) was detected using a simplified high pressure liquid chromatography technique. PAC was detected in both xylem and phloem sap 6 months after trees were injected with the compound. PAC is believed to be exclusively xylem mobile in plants, thus its detection in the phloem during this experiment was unexpected. The technique presented is simple and effective and avoids the use of radioactive material and complicated purification processes before analysis. Received February 25, 1997; accepted July 18, 1997     

A rapid and specific fluorescent activity staining procedure for transamidating enzymes.

A rapid, sensitive, and specific procedure has been developed for detection of transsamidatingenzymes (transglutaminase, e.g., factor XIII) after agarose gel electrophoresis. The technique is based on the transamidase-catalyzed incorporation of the fluorescent monodansylthiacadaverine into casein. The high sensitivity enables detection and characterization of transamidases in blood plasma, platelet, and red blood cell lysate and tissue extracts. The technique can also be combined with crossed immunoelectrophoresis.     

大肠杆菌murB和birA基因的转录通读现象

在对应用限制性显示 PCR技术构建的大肠杆菌 poly(A)化mRNA的cDNA文库鉴定中 ,发现了一克隆的基因片段同时跨越了murB和birA基因的部分序列 ,提示这 2个基因存在转录通读现象 ,设计引物 ,利用逆转录后的产物为模板 ,进行了验证。结果表明murB和birA基因存在转录通读现象。