热带－亚热带森林中猕猴的食性

采用跟踪观察法对热带－亚热带森林中的猕猴种群的食性及其与植被类型的关系进行了调查,结果表明,猕猴主要选择季雨林或次生季雨林为其觅食场所,栖息地植物的地理分布和种类直接影响其食性,猕猴对植物各部位的采食频度随植物生长期而变化．     

发酵活性豆渣饲料的研究

活性豆渣饲料是新鲜豆渣经微生物发酵而得到的。本文介绍了发酵菌株的筛选过程,并对发酵的最适条件进行了研究。分析结果表明,这种饲料含有蛋白酶等多种酶类,蛋白质、氨基酸的含量均比未发酵的豆渣有所增加,而且克服了豆渣含水量大、易腐败的缺点,有利于畜禽更充分地消化吸收。经动物喂养实验证明．活性豆渣饲料可代替５０％以上的鱼粉,是一种非常理想的蛋白饲料。     

地高辛标记反意RNA探针检测脑组织切片生长抑素mRNA

本实验采用含大鼠生长抑素基因的ｐＳＰ６５ｃＤＮＡ质位通过转化至噬菌体内大量扩增,经提取,纯化后,用限制性内切酶进行酶切使质枝线性化,并将其作为模板,用地高辛（ＤｉｇｏｘｉｇｅｎｉｎＤｉｇ）作为标记物,体外转录合成生长抑素反意ＲＮＡ（ｃＲＮＡ）探针。实验动物选用ｗｉｓｔａｒ新生大鼠。冰冻切片,端、间脑切片经杂交前用Ｄｉｇ－ＵＴＰ标记的ｃＲＮＡ探针杂交,杂交后用抗Ｄｉｇ－碱性磷酸酶复合物进行酶联免疫反应。Ｘ－磷酸盐－ＮＢＴ显色。结果显示新生大鼠脑内生长抑素ｍＲＮＡ神经元着紫蓝色。杂交反应物集中于核周的胞浆及短小的突起内。胞核不着色。胞体轮廓清晰,周围背底浅淡。结果表明Ｄｉｇ标记ｃＲＮＡ探针不仅具备非同位素标记探针的优点而且能快速和准确检测组织细胞内ｍＲＮＡ的表达。     

钙／钙调素依赖性蛋白激酶对17．7kD和6kD胰腺蛋白的磷酸化

本文报导了胰腺提取物中两种可被钙／钙调素依赖性蛋白激酶磷酸化的热稳定蛋白。ＳＤＳ－ＰＡＧＥ测定其表观分子量分别为１７．７ｋＤ和６ｋＤ。经钙／钙调素依赖性蛋白激酶磷酸化后,其最大磷酸参入量为８．８μｍｏｌ／ｇ蛋白。同时磷酸化作用导致１７．７ｋＤ蛋白在ＳＤＳ－ＰＡＧＥ中迁移率发生变化。本文还进一步分析了各种阳离子对磷酸化的影响,并对此两种蛋白可能具有的生理功能进行了初步探讨。     

The giant panda is closer to a bear,judged by α- and β-hemoglobin sequences

Summary Using - and -hemoglobin sequences, we made a maximum likelihood inference as to the phylogenetic relationship among carnivores, including the two pandas, giant and lesser. Molecular phylogenetic studies up to 1985 had consistently indicated that the giant panda is more closely related to the bear than to the lesser panda. In 1986, however, a contradictory tree was constructed, using hemoglobins and so on, in which the two pandas link together (Tagle et al. 1986). In contrast to that tree, our conclusion supports the close relationship between bear and giant panda. The surface impression of a close relationship between the two pandas drawn from pairwise amino acid differences is explained by a rapid rate of hemoglobin evolution in the bear compared to that in the two pandas.Offprint requests to: T. Hashimoto     

Selective Adhesion of Thiobacillus ferrooxidans to Pyrite

Bacterial adhesion to mineral surfaces plays an important role not only in bacterial survival in natural ecosystems, but also in mining industry applications. Selective adhesion was investigated with Thiobacillus ferrooxidans by using four minerals, pyrite, quartz, chalcopyrite, and galena. Escherichia coli was used as a control bacterium. Contact angles were used as indicators of hydrophobicity, which was an important factor in the interaction between minerals and bacteria. The contact angle of E. coli in a 0.5% sodium chloride solution was 31°, and the contact angle of T. ferrooxidans in a pH 2.0 sulfuric acid solution was 23°. E. coli tended to adhere to more hydrophobic minerals by hydrophobic interaction, while T. ferrooxidans selectively adhered to iron-containing minerals, such as pyrite and chalcopyrite. Ferrous ion inhibited the selective adhesion of T. ferrooxidans to pyrite competitively, while ferric ion scarcely inhibited such adhesion. When selective adhesion was quenched by ferrous ion completely, adhesion of T. ferrooxidans was controlled by hydrophilic interactions. Adhesion of E. coli to pyrite exhibited a liner relationship on langmuir isotherm plots, but adhesion of T. ferrooxidans did not. T. ferrooxidans recognized the reduced iron in minerals and selectively adhered to pyrite and chalcopyrite by a strong interaction other than the physical interaction.     

Mechanism of microbial flotation using Thiobacillus ferrooxidans for pyrite suppression

Microbial desulfurization might be developed as a new process for the removal of pyrite sulfur from coal sluries such as coal-water mixture (CWM). An application of iron-oxidizing bacterium Thiobacillus ferrooxidans to flotation would shorten the periods of the microbial removal of pyrite from some weeks by leaching methods to a few minutes. The floatability of pyrite in flotation was mainly reduced by T. ferrooxidans itself rather than by other microbial substances in bacterial culture as additive of flotation liquor. Floatability was suppressed within a few seconds by bacterial contact. The suppression was proportional to increasing the number of cells observed between bacterial adhesion and the suppression of floatability. If 25% of the total pyrite surface area covered with the bacteria, pyrite floatability would be completely depressed. Bacteria that lost their iron-oxidizing activities by sodium cyanide treatment were also able to adhere to pyrite and reduced pyrite floatability as much as normal bacteria did. Thiobacillus ferrooxidans ATCC 23270, T-1, 9, and 11, which had different iron-oxidizing abilities, suppressed floatability to similar-levels. The oxidizing ability of bacteria did not influence the suppressing effect. These results showed the mechanism of the suppression of pyrite floatability by bacteria. Quick bacterial adhesion to pyrite induced floatability suppression by changing the surface property from hydrophobic. The quick adhesion of the bacterium was the novel function which worked to change the surface property of pyrite to remove it from coal. (c) 1993 John Wiley & Sons, Inc.     

甲基毒死蜱对红细胞膜乙酰胆碱酯酶的抑制作用及其与膜脂相互关系

以人红细胞膜为材料,研究了甲基毒死蜱与膜上乙酰胆碱酯酶(AChE)的相互作用及其与膜脂的关系。结果显示,甲基毒死蜱对人红细胞膜AChE有明显的抑制作用,与膜温育30min,其半数抑制浓度约为0.10 mmol/L。动力学分析表明,其抑制作用为非竞争性。0.2％Triton X-100并不改变AChE对甲基毒死蜱的敏感性,亦即AChE上甲基毒死蜱的作用部位与其所处的脂质微环境无关。     

Isolation and characterization of axolemma-enriched fractions from rabbit and bovine peripheral nerve

Axolemma-enriched fractions were isolated from bovine spinal accessory nerves, bovine intradural dorsal roots, and rabbit sciatic nerve by differential centrifugation and separation on a linear 10–40% sucrose (w/w) gradient. The fractions were enriched 4 to 10 fold in acetylcholinesterase, a biochemical marker for axolemma. Axolemma-enriched fractions isolated from uniformly well-myelinated fibers (bovine spinal accessory nerve) contained lower CNPase activity and higher acetylcholinesterase activity than comparable fractions isolated from variably myelinated fibers (rabbit sciatic nerve and bovine intradural roots). Separation by polyacrylamide electrophoresis showed that the molecular weight distribution of all peripheral nerve axolemma-enriched fractions was similar and ranged from 20 to over 150 kilodaltons. All axolemma-enriched fractions appeared to contain a small but variable amount of myelin-specific proteins. Based on biochemical properties, peripheral nerves containing uniformly well-myelinated fibers yield an axolemma-enriched fraction which is least contaminated with myelin-related membranes.