Use of agar-based diet to fulfil the food and water requirements of mice

Mice were fed an agar-based diet without an additional source of water for 5 weeks. In comparison with a similar group of mice fed a commercial diet and water ad libitum, there were no significant changes in bodyweight.     

Passive Transfer of Lambert-Eaton Myasthenic Syndrome in Mice: Decreased Rates of Resting and Evoked Release of Acetylcholine from Skeletal Muscle

Mice were injected for 1-2 months daily with 10 mg immunoglobulin G (IgG) from four patients with Lambert-Eaton myasthenic syndrome (LEMS); control mice were injected with pooled human IgG from normal donors. Gastrocnemius muscles were homogenised for the assay of acetylcholine (ACh), choline acetyltransferase (ChAT), and cholinesterase (ChE). The ACh, ChAT, and ChE contents of gastrocnemius muscles from "LEMS mice" were about the same as the control values, which were 180 pmol, 40 nmol X h-1 (37 degrees C), and 15 mumol X h-1 (37 degrees C), respectively. Hemidiaphragms were treated with an irreversible ChE inhibitor (Soman) and incubated at 20 degrees C for estimation of ACh release. Resting ACh release from experimental muscles was reduced by about 25% (P2 less than 0.05) and the release evoked by 3 s-1 nervous stimulation by 50% (P2 less than 0.05). On the other hand, 50 mM KCl-induced transmitter release was not abnormal in LEMS mice. The findings indicate that IgG antibody from patients with LEMS may bind to nerve terminal determinants that are involved in quantal and nonquantal ACh release.     

Electron microscopy of bacteriophage phi 6 nucleocapsid: three-dimensional image analysis.

Electron micrographs of bacteriophage phi 6 nucleocapsids, negatively stained by neutralized phosphotungstate and tilted in a goniometer specimen cartridge, proved that the three distinct morphologies seen in the electron microscope are merely three different aspects of a single nucleocapsid structure and strongly suggested that this structure is dodecahedral.     

鄱阳湖水生植被

本文列出了鄱阳湖98种水生维管束植物的名录,叙述了水生植被的分布。鄱阳湖水生植被面积为2262平方公里,占全湖总面积的80．8％。湖中植被呈不规则环带状分布,并可划分为湿生、挺水、浮叶和沉水4个植物带,9个主要植物群丛。并研究了鄱阳湖水生植被的演变及发展趋势和湖水位的季节性变化对植被的影响。     

诱发斑点小球腔菌假囊壳生成的条件

自然界甘蓝茎点霉(Phoma lingam)的有性世代为斑点小球腔菌Leptosphaeriamaculans通常形成于甘蓝属植株的越冬残茎上。在实验室内其有性阶段不易培养或需要较长的时间,而且形成假囊壳的百分率也很低。为了在实验室内能短期诱发大量L.maculans的假囊壳,本实验研究了该菌假囊壳生成的条件,创造了双层培养方法。自澳大利亚采集到有该菌假囊壳的芸苔(Brassica napus)残基,分离得到子囊孢子单孢后代数十株,同时用保存的已知交配型665(+)和666(-)为材料,研究了(+)(-)配对结合的环境条件。实验结果表明16℃的温度,近紫外光照射(黑光灯)和V_(?)麦杆琼脂培养基上可以产生少量的假囊壳。但是,若配合以双层培养,则在培养4周后可产生大量成熟的假囊壳。实验还确定了该菌在性细胞形成、交配、子囊形成和成熟等阶段对环境因子都有不同的要求。双层培养对假囊壳的发育有重要作用。前期菌体营养生长与后期假囊壳的成熟紧密相关。     

Formation of cellobiose lipids by growing and resting cells of Ustilago maydis

Summary Utilizing coconut oilUstilago maydis ATCC 14826 synthesizes cellobiose lipids under N-limitation conditions and as resting cells, which gave the highest specific biosurfactant production (0.79 g/g substrate). C6-, C12-, C14-, and 15, 16-dihydroxy-C16-fatty acids are the main components of the lipophilic moiety of these glycolipids.     

Monoclonal antibodies to human cytokeratins: application to various epithelial and mesothelial cells

Immunohistological analysis of human tissue using monoclonal antibodies against cytokeratins, which are confined to cells of epithelial origin, is a valuable technique. Using human epidermal keratins as antigen, we prepared monoclonal antibodies against cytokeratins (ZK1, ZK7, ZK61 and ZK99) and against a desmosomal protein (ZK31). Immunohistochemical staining of human skin sections using these antibodies showed a specific reaction with the epidermis: ZK1 stained the entire epidermis, ZK7 only the basal layer, ZK61 and ZK99 the suprabasal layers, and ZK31 the cellular interfaces. In order to test for antibody specificity, immunoblots with human epidermal and amnion epithelial cytokeratin polypeptides, as well as immunofluorescence microscopy of simple epithelia (glandular and simple columnar epithelia) were performed. ZK1, ZK61 and ZK99 reacted preferentially with cytokeratin polypeptides of stratified squamous epithelia and ZK7 recognized cytokeratins of stratified and simple epithelia. When the ZK antibodies were tested on mesothelial cells in pleural effusions, only ZK7 reacted with these cells. Biochemical analysis of cytokeratin accumulation in cells of primary and long-term cultures indicated that the cytokeratin pattern of mesothelial cells was quite unstable, while that of amnion epithelial cells showed only minor quantitative changes. The use of these antibodies to determine the epithelial origin of cells present in pleural effusions is proposed.     

A collection of programs for nucleic acid and protein analysis, written in FORTRAN 77 for IBM-PC compatible microcomputers.

We have developed a collection of programs for manipulation and analysis of nucleotide and protein sequences. The package was written in Fortran 77 on a Sirius1/Victor microcomputer which can be easily implemented on a large variety of other computers. Some of the programs have already been adapted for use on a Vax 11. Our aim was to develop programs consisting of small, comprehensible and well documented units that have very fast execution times and are comfortably interactive. The package is therefore suitable for individual modifications, even with little understanding of computer languages.     

Isolation and characterization of prolyl hydroxylase from Chlamydomonas reinhardii

Prolyl hydroxylase, which is responsible for the hydroxylation of peptidyl proline residues, has been isolated and purified from the green alga Chlamydomonas reinhardii. The enzyme, which appears to be loosely associated with microsomal membranes, was released into solution by sonication in the presence of detergent. Purification was achieved by ion-exchange chromatography followed by affinity chromatography using the immobilized substrate poly-L-proline. Apart from its differing substrate specificity the enzyme appears to possess similar molecular characteristics to prolyl hydroxylase isolated from animal tissues: the active enzyme is a tetramer of about 240–250 kDa and nonidentical monomers of 65 and 60 kDa. The monomers are capsule shaped having a dimension of 12×7 nm.Abbreviations Da dalton - DEAE diethylaminoethyl - DTT dithiothreitol - Hepes 4-(2-hydroxymethyl)-1-piperazine ethanesulfonic acid - -KGA -ketoglutarate - PAGE polyacrylamide gel electrophoresis - SDS sodium dodecyl sulfate