韦氏鳞(虫八)的精子结构(双尾目)

韦氏鳞(虫八)(Lepidocampa weberi)精子为细长的鞭毛精子,成束排列成精索。顶体由三层结构组成;核圆柱形,接于顶体后;鞭毛轴丝微管式为“9+9+2”,9条副微管排列不整齐,集中于轴丝的一侧;两条细长的线粒体衍生物位于顶体、核与轴丝之间,贯穿于精子中部;精子尾部围有大量片层结构。结果表明韦氏鳞(虫八)精子与康(虫八)精子较为接近,但可能比康(虫八)精子更为特化。     

Glutathione production in copper-deficient isolated rat hepatocytes.

Dietary copper deficiency has been shown to reduce copper-dependent superoxide dismutase (SOD) activity and to increase lipid peroxidation in rats. Circulating reduced glutathione (GSH) concentrations are elevated in copper-deficient (CuD) rats, which suggests an increased GSH synthesis or decreased degradation, perhaps as an adaptation to the oxidative stress of copper deficiency. GSH synthesis was examined in isolated hepatocytes from CuD rats. Isolated hepatocytes were prepared by collagenase perfusion and incubated in Krebs-Henseleit bicarbonate buffer, pH 7.4, 10 mM glucose, 2.5 mM Ca2+ in the presence and absence of 1.0 mM buthionine sulfoximine (BSO), a specific inhibitor of GSH synthesis. Cell viability was assessed by trypan blue exclusion. GSH and oxidized glutathione (GSSG) were measured by the glutathione reductase recycling assay. Copper deficiency depressed hepatocyte Cu by greater than 90% and increased intracellular GSH by 41-117% over the 3-h incubation, with a two- to threefold increase in the rate of intracellular GSH synthesis. Intracellular GSSG values were minimally influenced by CuD, with a constant mol% GSSG. Extracellular total glutathione (GSH + 2GSSG) synthesis was increased by approximately 33%. Both intracellular GSH and extracellular total glutathione synthesis were inhibited by BSO. The pattern of food consumption in CuD rats, meal fed versus ad libitum fed, had no effect on glutathione synthesis. The results indicate an increased hepatic GSH synthesis as a response to dietary copper deficiency and suggest an interrelationship between the essential nutrients involved in oxyradical metabolism.     

The antigen of hepatitis delta virus: examination of in vitro RNA-binding specificity.

The only known protein of hepatitis delta virus (HDV), the delta antigen, is found both within virus particles and within the nucleus of the infected cell, where it has one or more roles essential for RNA genome replication. Others have demonstrated that the antigen has the ability, in vitro, to specifically bind HDV RNA species. We report a further examination of this phenomenon, using partially purified recombinant protein, expressed as a fusion with the staphylococcal protein A. From Northwestern (RNA-immunoblot) analyses with both complete and various subdomains of HDV genomic and antigenomic RNAs, we found that a necessary feature for specific binding was that the RNA be able to fold to some extent into the so-called rodlike structure; this structure is a predicted intramolecular partial base-pairing of the circular RNA, with about 70% of all bases involved, so as to produce an unbranched rodlike structure. Six different subregions of the HDV rodlike structure, three on the genomic RNA and three on its complement, the antigenomic RNA, were tested and found to be sufficient for antigen binding. However, features in addition to the rodlike structure may also be necessary for specific binding, because we found that a similar structure present in the RNA of the potato spindle tuber viroid did not allow binding.     

A general method for biological parameter estimation

Summary A general observer-based estimator method is developed and applied for process modelling and monitoring. This parameter estimation technique was successfully applied to a L-lysine fermentation process. It was a useful tool to detect the effect of major culture conditions on cell growth and product synthesis. It can also be used for the development of adaptive optimal control schemes.     

亚洲象无齿奎隆线虫一新种：（圆形亚目：毛线科）

本文报道作者近年来在石家庄动物园对亚洲象Elephas maximus进行药物驱虫时采集的寄生线虫一新种,无齿奎隆线虫,新种Quilonia edentata sp.nov.,模式标本保存于河北师范大学生物系。     

利用普通怯寄蝇防治菜粉蝶初探

1 前言 从外地引进寄蝇或人工助长当地寄蝇种类防治农林害虫,是有效的生防手段之一,国外已有很多成功的报道。King等(1981)在路易斯安娜州蔗田中人工大量释放螟利索寄蝇(Lixophaga diatraeae)成虫防治第1代小蔗杆草螟(Diatraea saccharalis),不同地区的寄生率分别达到4.1、8.7和35.7％;由于降低了农药的使用量,奇痣窄径茧蜂(Agathis stigmatera)的自然寄生率也相应提高,很好地控制了蔗田害虫的发生。在寄蝇的田间释放技术方面,国外还没有详细的报道。在我国,利用寄蝇防治害虫的工作也是刚刚起步,很多具体问题有待于进一步研究。     

Nascent high density lipoproteins from liver perfusates of orotic acid-fed rats

Uniformly fatty livers from orotic acid-fed rats secreted almost no very low density lipoproteins (VLDL) but normal amounts of nascent high density lipoproteins (HDL) accumulated in perfusates. When lecithin:cholesterol acyltransferase (LCAT) was inhibited, nascent HDL were uniformly discoidal and lacked cholesteryl esters. Lipid and apoprotein compositions of nascent HDL from normal and fatty livers were similar whether LCAT was inhibited or not. Apolipoprotein B-100 was not detected in perfusates of uniformly fatty livers, but small amounts of apolipoprotein B-48 were present in HDL2 fractions. Nascent lipoproteins were not seen in Golgi compartments, but lipid-rich particles were clearly evident in endoplasmic reticulum cisternae adjacent to the cis face of the Golgi complex, suggesting that orotic acid blocks VLDL secretion by preventing translocation of nascent particles from the endoplasmic reticulum to the cis Golgi compartment. The accumulation of normal amounts of discoidal HDL in liver perfusates despite virtual absence of triglyceride-rich lipoproteins in Golgi secretory compartments, the space of Disse, and the perfusate is inconsistent with the concept that nascent HDL are exclusively a product of surface remnants cast off during lipolysis of chylomicrons and VLDL.     

斯氏狸殖吸虫螺类宿主新记录:洪山拟钉螺新种记述

本文报道斯氏狸殖吸虫新的螺类宿主——洪山拟钉螺Tricula hongshanensis sp. nov.的特点:螺壳较宽而短,体螺层较高大,壳口上缘成锐角,触角伸展时较长,收缩吋有环状皱褶,雄性阴茎较粗短,末端钝圆,齿舌公式不同于其它拟钉螺。