Calcium antagonists in hypertension: relation to abnormal sodium transport.

Leucocyte sodium efflux rate constants and intracellular electrolyte contents were estimated in 13 patients with untreated essential hypertension. There was no correlation between intracellular sodium or potassium content or efflux rate constant and blood pressure. The patients were then treated with oral nifedipine and blood pressure controlled. Sodium efflux rate constants and electrolyte contents were estimated one and three months after the start of treatment. There was a significant fall in blood pressure, but mean sodium efflux rate constant and intracellular sodium content were unchanged. There was no correlation between the fall in blood pressure, initial sodium efflux, or intracellular sodium content. These data do not support the hypothesis that the sodium pump and intracellular sodium content have a direct role in generating raised blood pressure, or that treatment of hypertension with calcium antagonists corrects a fundamental alteration of calcium-sodium exchange across the cell membrane.     

高产融合子Q4413的形态学与生理生化特征的研究

本文通过对枯草芽孢杆菌BR151衍生株与北京棒杆菌1134衍生株的赖氨酸高产融合子Q4413株的形态学、生理生化特性等方面的研究,揭示了融合子与双亲株在这些方面的差异,为Q4413株确系双亲株的重组子或新的融合子增加了佐证.     

氨基酸营养当量和整齐性指数

化学法以蛋白质的氨基酸组成评价蛋白质营养价值。在分析化学法的一般思想和方法的基础上,本文引进氨基酸营养当量和营养当量数的概念,并提出一个称为“整齐性指数”的新化学指数。使化学评价蛋白质营养价值的方法理论化,并使化学指数在反映蛋白质营养价值上更加精确可靠;本文同时还揭示了化学法中常用的化学分指标能较理想反映蛋白质营养价值的内在原因,通过实例分析,本文还证实了蛋白质的氨基酸组成对蛋白质的消化率存在影响的作用。     

鄂东花马湖水生高等植物研究：Ⅰ.水生植物区系

花马湖位于北纬30°15′—30°18′、东经114°58′—115°1′,面积约27.5km~2。湖中分布82种2变种水生维管束植物,隶属于34科66属,其中资源植物众多。花马湖水生高等植物大型属少,小型属较多,单型属相对突出。区系地理成分以温带成分占优势,计34种,占全湖种类的40.48%。起源古老的成分也较多。通过与有关湖泊水生植物区系的比较,及区系成分的分析,说明花马湖水生植物区系具有从暖温带至中亚热带过渡的特点。     

眼底图象定量分析

本文介绍了基于数学形态学的图象分析系统在生物医学,特别是眼底图方面日益广泛的应用.提出了运用图象分析系统取得眼底照片上一些参数的方法.主要参数包括:动静脉管径及其比例,无灌注区的面积等.这些参数不仅用于眼科方面的诊断和治疗,对于分析和诊断全身性疾病,如高血压、动脉硬化、糖尿病、静脉阻塞等都具有重要价值     

Location of a Bombyx mori receptor binding region on a Bacillus thuringiensis delta-endotoxin.

Receptor binding studies were performed with 125I-labeled trypsin-activated insecticidal toxins, CryIA(a) and CryIA(c), from Bacillus thuringiensis on brush-border membrane vesicles (BBMV) prepared from Bombyx mori larval midgut. Bioassays were performed by gently force feeding B. mori with diluted toxins. CryIA(a) toxin (LD50; 0.002 micrograms) was 200 times more active against B. mori larvae than CryIA(c) toxin (LD50; 0.421 micrograms) and showed high-affinity saturable binding. The Kd and the binding site concentration for CryIA(a) toxin were 3.5 nM and 7.95 pmol/mg, respectively. CryIA(c) toxin (Kd, 50.35 nM; Bmax, 2.85 pmol/mg) did not demonstrate high-affinity binding to B. mori BBMV. Control experiments with CryIA(a) and CryIA(c) toxins revealed no binding to mouse small intestine BBMV and nonspecific binding to pig kidney BBMV. These data provide evidence that binding to a specific receptor on the membrane of midgut epithelial cells is an important determinant with respect to differences in insecticidal spectrum of insecticidal crystal proteins. To locate a B. mori receptor binding region on the CryIA(a) toxin, homologous and heterologous competition binding studies were performed with a set of mutant proteins which had previously been used to define the B. mori "specificity domain" on this toxin (Ge, A. Z., Shivarova, N. I., and Dean, D. H. (1989) Proc. Natl. Acad. Sci. U.S.A. 86, 4037-4041). These mutant proteins have had regions of their genes reciprocally exchanged with the cryIA(c) gene. A B. mori receptor binding region on CryIA(a) toxin includes the amino-terminal portion of the hypervariable region, amino acids 332-450, which is identical to the previously described B. mori specificity determining region. These data provide direct evidence that delta-endotoxins contain a tract of amino acids that comprise a binding region and as a results determines the specificity of a toxin.     

A simplified method for the determination of nitric oxide in biological solutions.

A new simplified procedure for determination of nitric oxide (NO) in biological solutions is described utilizing a new reducing system of nitric oxide prior to chemiluminescence. Advantages of the new method makes heating of the reducing solution unnecessary and avoids cooling and condensation of generated vapors. Only traces of acid with a high boiling point are used. The method permits analysis of small sample volumes (200 microL). The basal production of nitric oxide by freshly harvested endothelial cells ranged from 100 to 880 picomoles.     

A hybrid cell mapping panel for regional localization of probes to human chromosome 8

We have characterized a panel of somatic cell hybrids that carry fragments of human chromosome 8 and used this panel for the regional localization of anonymous clones derived from a chromosome 8 library. The hybrid panel includes 11 cell lines, which were characterized by Southern blot hybridization with chromosome 8-specific probes of known map location and by fluorescent in situ hybridization with a probe derived from a chromosome 8 library. The chromosome fragments in the hybrid cell lines divide the chromosome into 10 intervals. Using this mapping panel, we have mapped 56 newly derived anonymous clones to regions of chromosome 8. We have also obtained physical map locations for 7 loci from the genetic map of chromosome 8, thus aligning the genetic and physical maps of the chromosome.     

Temporal relationships betweenZea mays,ostrinia nubilalis (Lep.: Pyralidae) and endophyticBeauveria bassiana

The entomopathogenic fungus,Beauveria bassiana (Balsamo) Vuillemin, was applied to whorl-stage (V7) corn,Zea mays L., by foliar application of a granular formulation of corn grits containing conidia or by injection of a conidial suspension. All plants were infested with European corn borer larvae,Ostrinia nubilalis (Hübner), at the V7 (whorl), V12 (late-whorl), or V17 (pretassel) stage of plant development. Plants infested at whorl and late-whorl stages had significantly more European corn borer tunneling than did plants infested at the pretassel stage. The percentage of plants colonized byB. bassiana did not differ significantly among the whorl, late-whorl, and pretassel stages. As the plants matured,B. bassiana was isolated from different plant areas, with the pith more frequently colonized than the leaf collars. Foliar application ofB. bassiana provided immediate suppression ofO. nubilalis in those plants infested at whorl stage. The reduced efficacy ofB. bassiana at the intermediate plant stages relative to efficacy at harvest is discussed. The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

~(125)Ⅰ标记单抗LC-I与肺腺癌细胞体内外结合特性的研究

本文用~(125)Ⅰ标记LC-1进行了一些体内外实验。实验结果表明:LC-1单抗的结合常数为4.8×10~8M~(-1),LC-1针对的SPC-A_1细胞表面抗原的位点数为7.2×10~4/细胞;LC-1与LAC-122两单抗针对的抗原决定簇没有交叉;用蛋白酶和过碘酸钠处理SPC-A_1细胞,前者对LC-1的结合抑制39%,后者抑制66%;LC- 1不但有较强的体外结合靶细胞的能力,从LC-1在荷瘤裸鼠中的组织器官分布来看,LC-1与肿瘤有较高的体内亲和性,并且是特异性的结合。