Yersinia pseudotuberculosis in China

Thirty strains of Yersinia pseudotuberculosis were isolated from rabbits (17 strains), wild rats (9 strains) and house rats (4 strains) in China between 1990 and 1993. The biochemical properties of these isolates were identical with those of Y. pseudotuberculosis and no special characteristics were found in these strains. Serologically, serogroups 4b and 5b were identical to isolates found in Japan, and a new serogroup 1c and unclassified strains have also been detected. The existence of virulence-associated properties were different among strains. The pYV plasmid was detected from 6 strains of 30 isolates. This report documents the presence of Y. pseudotuberculosis in China, providing important epidemiological information.     

四川地区幼儿和学龄前儿童的鼻部测量

本文报告１１１６例四川地区幼儿和学龄前儿童（２－７岁）鼻部９项指标的测量均数,性差及年龄发育特点。性差：仅鼻凹鼻底距４－６．５岁等少数指标部分年龄段男女性间出现显著性划异（男＞女）。此外各项指标的绝大多数年龄段男女性间无显著性差异。年龄发育：９项测量指标中７项的生长曲线随年产长而上升,数值随年龄增大,并有１－２个发育高峰;提示鼻部发育具有阶段性;２项指标的曲线随年龄增长变化较小。４项指标男女性的曲     

苯并噻唑醌类化合物对呼吸链酶系的抑制作用

合成了2-氯-5-正十二硫烷基-6-甲基-4,7-苯并噻唑醌(2-Cl-DMMDBT)和2-氯-5-正丁烷氨基-6-甲基-4,7-苯并噻唑醌(2-Cl-BAMDBT)两种化合物,研究了它们对线粒体呼吸链酶系的抑制作用.结果表明:2-Cl-DMMDBT和2-C1-BAMDBT对琥珀酸氧化酶及泛醌氧化酶的电子传递活性均表现一定的抑制作用,而对细胞色素氧化酶无作用,说明二者的抑制作用发生在泛醌反应区.二者对NADH氧化酶的抑制行为略有不同,2-Cl-DMMDBT是一个逐渐加强的过程,最终可致酶活性完全抑制,而2-Cl-BAMDBT则表现为瞬间抑制.比较了2-Cl-DMMDBT和2-Cl-BAMDBT对琥珀酸氧化酶的抑制能力,长侧链的2-Cl-DMMDBT比短侧链的2-Cl-BAMDBT抑制能力强很多.     

科尔沁沙质草甸草场不同牧压条件植物群落分异数量分析

本文用ＴＷＩＮＳＰＡＮ分类和ＰＣＡ及ＤＣＡ排序技术分析了沙质草甸草场放牧试验引起地植物群落分异的特征,主要结论为：放牧强度是引起群落分异的主要原因,群落的分异主要表现在高度和现存生物量上。放牧引起群落变化的动力主要是放牧强度。而无牧条件下群落变化的主要动力是植物间的相互作用。当地的放牧强度处于中牧与重牧之间,属于过度放牧。这是引起草场退化及沙漠化的主要原因之一。     

Mechanism of Action of Lycoricidinol, a Plant Growth Inhibitor Isolated from Lycoris radiata Herb.

We studied the action mechanism of lycoricidinol, a plant growthinhibitor isolated from Lycoris radiata Herb. Lycoricidinolinhibited protein synthesis in mung bean hypocotyls, but notRNA synthesis. Protein synthesis in Escherichia coli was notaffected by the inhibitor. Results of in vitro translation experimentswith the wheat germ system and the E. coli system indicatedthat lycoricidinol inhibited only eukaryotic but not prokaryotictranslation. Use of specific inhibitors of initiation and polypeptidechain elongation of polypeptide synthesis revealed that chainelongation was inhibited by lycoricidinol. ¹Permanent address: Department of Biology, Yonsei University,Seoul 120, Korea. (Received September 30, 1983; Accepted December 28, 1983)     

Morphology,physiology and infectivity of twoFrankia isolates An 1 and An 2 from root nodules ofAlnus nitida

Summary Two different strains, An 1 and An 2, were obtained from root nodules ofAlnus nitida Endl., collected from one locality in the area of its natural habitat near Bahrin, District Swat, Pakistan. The light and electron microscopy of the isolates revealed the occurrence of septate and branched hyphae bearing sporangia and vesicles. The strains differed in their growth requirements, nitrogen-fixing ability and production of extracellular pigments, thus indicating the existence of more than oneFrankia strain in the same locality. In the absence of combined nitrogen in the medium strain An 1 formed vesicles and fixed N₂ (up to 200 nmol C₂H₄. mg protein^–1.h^–1), while strain An 2 under the experimental conditions formed only few vesicles and fixed N₂ at a very low rate (ca 10 nmol C₂H₄. mg protein^–1 .h^–1). The nitrogenase activity of strain An 1 was strongly affected by the O₂ concentration.Frankia An 1 and An 2 were infective and effective onA. nitida andA. glutinosa but not onDatisca cannabina andElaeagnus umbellata. Both An 1 and An 2 strains were more infective and effective onA. glutinosa thanFrankia strains AvcIl and CpI1.     

冬小麦春化过程中低温诱导的与花芽分化相关的mRNA和蛋白质的合成

应用SDS电泳及高分辨双向电泳技术,分析了冬小麦经春化、脱春化及超期春化处理后茎类蛋白质组分的变化。发现52.5,38kD和16.2kD蛋白质与冬小麦开花诱导密切相关。mRNA体外翻译结果表明,春化作用中低温诱导与开花紧密相关的mRNA的出现有一定的顺序性。因此推测:春化诱导开花是低温导致某些特定基因表达的结果,而表达的调节主要发生在转录水平上。     

Comprehensive profiling of accessible surface glycans of mammalian sperm using a lectin microarray

It is well known that cell surface glycans or glycocalyx play important roles in sperm motility, maturation and fertilization. A comprehensive profile of the sperm surface glycans will greatly facilitate both basic research (sperm glycobiology) and clinical studies, such as diagnostics of infertility. As a group of natural glycan binders, lectin is an ideal tool for cell surface glycan profiling. However, because of the lack of effective technology, only a few lectins have been tested for lectin-sperm binding profiles. To address this challenge, we have developed a procedure for high-throughput probing of mammalian sperm with 91 lectins on lectin microarrays. Normal sperm from human, boar, bull, goat and rabbit were collected and analyzed on the lectin microarrays. Positive bindings of a set of ~50 lectins were observed for all the sperm of 5 species, which indicated a wide range of glycans are on the surface of mammalian sperm. Species specific lectin bindings were also observed. Clustering analysis revealed that the distances of the five species according to the lectin binding profiles are consistent with that of the genome sequence based phylogenetic tree except for rabbit. The procedure that we established in this study could be generally applicable for sperm from other species or defect sperm from the same species. We believe the lectin binding profiles of the mammalian sperm that we established in this study are valuable for both basic research and clinical studies.