Toxicity to alveolar macrophages in rats following parenteral injection of mercuric chloride

Alveolar macrophages collected by pulmonary lavage from male Fisher-344 rats at intervals (24–72 h) after HgCl₂ injection (1–5 mg/kg, sc) were analyzed by several techniques. Within 24–72 h, the macrophages showed morphological signs of activation (hypertrophy and ruffled plasma membrane). Lipid peroxidation (increased malondialdehyde concentration) was not detected until 48 h. Dose- and time-related effects of HgCl₂ on malondialdehyde concentration and time-related effects of HgCl₂ on malondialdehyde concentration and mercury content of alveolar macrophages were observed 24–72 h postinjection. Diminished cell viability occurred only at 72 h after the highest dosage of HgCl₂. This study demonstrates that the alveolar macrophage was a cellular target for mercury toxicity following parenteral exposure to HgCl₂.     

Spread of beet necrotic yellow vein virus in infected seedlings and plants of sugar beet (Beta vulgaris)

Summary Infection of sugar beet roots by beet necrotic yellow vein virus (BNYVV) was investigated with transmission electron microscopy, immunogold labelling and enzyme linked immuno sorbent assay (ELISA). Here we show that infection of sugar beet roots is very fast, occurring during germination. Seedlings grown directly in infected soil showed higher BNYVV infection than plants transplanted into infected soil after seven days of initial growth in sterilized soil. The earlier the initial infection, the faster was its spread. The study showed that a few differentiated cells of the cortex and of the xylem parenchyma were the preferred sites of viral multiplication. The spread of viral infection was slow through differentiated tissues. Intact virions were frequently found in undifferentiated and mature vessel elements and xylem parenchyma, whereas they were rare in sieve elements. Virus particle number in the differentiating tracheary elements was high, suggesting that infection of the vessel elements preceded their differentiation. This would explain increased infection after early inoculation. Even the xylem tissue of the primary root was highly infected, the seedlings lacked virus particles in their hypocotyls and leaves.     

自发性高血压大鼠中枢5－HT_（1A）受体的特性

本文用放射性配基［３Ｈ］８－ＯＨ－ＤＰＡＴ的结合实验显示,自发性高血大鼠（ＳＨＲ）海马、下丘脑及低位脑干的５－ＨＴ１Ａ受体结合位点数较正常Ｗｉｓｔａｒ大鼠为多,其中以海马最为显著;脑干的５－ＨＴ１Ａ受体虽较正常Ｗｉｓｔａｒ大鼠多,但不太明显。ＳＨＲ下丘脑中５－ＨＴ１Ａ受体除结合位点较正常Ｗｉｓｔａｒ鼠多外,亲和力也有增大。以上结果表明,ＳＨＲ与正常Ｗｉｓｔａｒ大鼠之间各脑区中５－ＨＴ１Ａ受体的差别可能与高血压病的发生有关。     

Determination of ammonium and L-Glutamine in hybridoma cell cultures by sequential flow injection analysis

A flow injection anlytical system based on a gas diffusion membrane module for ammonia and an ammonium flow-through potentiometric detector has been set up for measurement of L-glutamine and ammonium ions in hybridoma cell cultures. The main feature of the system is that the same basic analytical concept and equipment is used in both measurements, the only difference being for the determination of L-glutamine, in which the sample flows through an immobilized glutaminase cartridge. The conditions to enable the performance of both analysis consecutively, avoiding potential interferences by unwanted deamination of other compounds in the samples, have been determined. Finally, the proposed system has been compared with reference analytical methods for batch hybridoma cell culture experiments.     

Seed transmission of turnip yellow mosaic virus in winter turnip and winter oilseed rapes

This is the first record of seed transmission of turnip yellow mosaic virus (TYMV) in oilseed and turnip rapes. The seed transmission of TYMV in a naturally infected winter turnip rape (Brassica napus var. silvestris) cultivar Perko PVH was investigated. By ELISA 1.6%, 3.2% and 8.3% seed transmission of the virus was found in seed of plants from three localities. The proportion of infected seeds produced by artificially infected plants of winter oilseed rape (Brassica napus ssp. oleifera) and winter turnip rape cultivars was determined. The virus transmission rate, expressed as the proportion of virus-infected plants which germinated from the seed was for the oilseed rape cvs Jet Neuf 0.1%, Solida 0.4%, Silesia 0.8%, Darmor 1.2%, SL-507 0.2%, SL-509 0.0% and for the winter turnip rape cv. Perko 1.5%. ELISA cannot be used in direct tests on bulk seed lots to estimate proportion of infected seed, but must be used on germinated seedlings.     

Monitoring glutamine in animal cell cultures using a chemiluminescence fiber optic biosensor

Together with flow injection analysis (FIA), a chemiluminescence (CL) fiber optic biosensor system has been developed for determining glutamine in animal cell cultures. Glutaminase (GAH) and glutamate oxidase (GLO) were onto separate porous aminopropyl glass beads via glutaraldehyde activation and packed to form an enzyme column. These two enzymes acted in sequence on glutamine to produce hydrogen peroxide, which was then reacted with luminol in the presence of ferricyanide to produce a light signal. An anion exchanger was introduced on-line to eliminate interfering endogenous glutamate in view of its negative charge at pH above 3.22 (isoelectric pH). Among several resins tested, the acetate form was most effective, and this type of ion exchanger also effectively adsorbed uric acid, acetaminophen, and aspartic acid.There was an excellent linear relationship between the CL response and standard glutamine concentration in the range 1 to 100 muM. A complete analysis could be performed in 2 min, including sampling and washing with a good reproducibility (+/- 4.4%). Both the bi-enzymic and ion exchange columns were useful for at least 500 analyses when the biosensor system was applied for the glutamine determination in murine hybridoma cell cultures and insect cell cultures. The values obtained compared well with those of HPLC, thus validating the applicability of the CL fiber optic system. (c) 1993 John Wiley & Sons, Inc.     

Spring dispersal ofSitona lineatus: The use of aggregation pheromone traps for monitoring

The spring dispersal ofSitona lineatus L. (Coleoptera; Curculionidae) was investigated on a Danish farm.S. lineatus dispersed by flight in the early spring on sunny, calm days with temperatures above ca. 15°C. Two thirds of the population ofS. lineatus dispersed from perennial leguminous crops (clover and lucerne) in the first period of flight activity. The next dispersal did not occur until one month later despite several intermediate flight activity periods. The first period of dispersal occurred before the germination of the spring sown summer host crop,Vicia faba L. The field bean crop was infested in three later invasions during a period of more than three weeks. The aggregation pheromone, 4-methyl-3,5-heptanedione, had a significant effect on captures of both males and females in cone traps placed on the ground. There was no effect of the pheromone on captures in yellow sticky traps placed 1.5 m above ground. The pheromone effect is discussed in relation to behavioural observations. Both types of traps may be used in a survey system for monitoring spring dispersal ofS. lineatus and optimal timing of insecticide spraying. However, the pheromone cone traps were highly specific whereas all kinds of flying insects were caught in the yellow sticky traps, thus making the latter traps less suitable for monitoring.     

芝麻病毒病害研究：Ⅱ.芝麻黄花叶病病原鉴定

继对芝麻矮化坏死病源研究之后,又对普遍发生的芝麻黄花叶病害分离物(YMo—I)进行了系统鉴定。该分离物普遍存在于各芝麻主产区,普通年份发病率为1～5％。YMo—I侵染芝麻引起叶片褪绿及黄绿相间花叶。摩擦接种能够侵染4科12种(品种)植物。局部侵染苋色藜、昆诺藜;系统侵染大豆、花生、望江南、克氏烟等。该病毒能够由桃蚜、花生蚜、大豆蚜以非持久性方式进行传播。ELISA检测其病株种子带毒率为0.5％,但尚未发现种生病苗。病毒在组织汁液中存活期3天;钝化温度55～60℃,稀释限点4×10~(-3)。提纯病毒为弯曲线状粒体,大小约为13×730nm。并有极易凝聚的趋势。病组织中诱导大量典型PVY第一亚组的风轮形和卷筒状细胞质内含体和少数多边形结晶核内含体。血清学上该病毒与花生条纹病毒(PStV)、西瓜花叶病毒—2(MMV—2)密切相关,与花生斑驳病毒、大豆花叶病毒弱相关;与芜菁花叶病毒不相关。但它不侵染WMV—2的寄主—黄瓜,并且该病害田间的发生流行与芝麻、花生的间作方式以及PStV在花生田间的流行密切相关。根据上述结果,YMo—I分离株被鉴定为花生条纹病毒的一芝麻分离株。     

Flow injection assays for NADH and ethanol using photosensitized rose bengal and luminol–copper (II) chemiluminescence system

The online photoreaction of the rose bengal photosensitized luminol–copper (II) chemiluminescence (CL) system was used for the determination of β-nicotinamide adenine dinucleotide (NADH) and ethanol (EtOH) in pharmaceutical formulations combined with a flow injection technique. NADH can significantly enhance the CL emission of the reaction. For EtOH, alcohol dehydrogenase in soluble form was utilized in the presence of nicotinamide adenine dinucleotide resulting in NADH production. The limit of detection (3σ blank, 𝑛 = 3) of 4.0 × 10⁻⁸ and 2.17 × 10⁻⁵ M, and linear range 1.3 × 10⁻⁷ to 2.5 × 10⁻⁵ M (R² = 0.9998, n = 6) and 0.11–2.17 × 10⁻³ M (R² = 0.9996, n = 6) were obtained for NADH and EtOH respectively. The injection rate was 100 h⁻¹ with a relative standard deviation (n = 3) of 1.5–4.8% in the range studied for both analytes. The procedure was satisfactorily applied to pharmaceutical formulations with recoveries in the range 91.6 ± 3.0% to 110 ± 2.0% for NADH and 88 ± 3.0% to 95.4 ± 4.0% for EtOH. The results obtained were very consistent and did not differ considerably from the reported approaches at a 95% confidence limit. The possible mechanism of the CL reaction is also explained briefly.     

Primary structure of a photoactive yellow protein from the phototrophic bacterium Ectothiorhodospira halophila,with evidence for the mass and the binding site of the chromophore.

The complete amino acid sequence of the 125-residue photoactive yellow protein (PYP) from Ectothiorhodospira halophila has been determined to be MEHVAFGSEDIENTLAKMDDGQLDGLAFGAIQLDGDGNILQYNAAEGDITGRDPKEVIGKNFFKDVAP+ ++ CTDSPEFYGKFKEGVASGNLNTMFEYTFDYQMTPTKVKVHMKKALSGDSYWVFVKRV. This is the first sequence to be reported for this class of proteins. There is no obvious sequence homology to any other protein, although the crystal structure, known at 2.4 A resolution (McRee, D.E., et al., 1989, Proc. Natl. Acad. Sci. USA 86, 6533-6537), indicates a relationship to the similarly sized fatty acid binding protein (FABP), a representative of a family of eukaryotic proteins that bind hydrophobic molecules. The amino acid sequence exhibits no greater similarity between PYP and FABP than for proteins chosen at random (8%). The photoactive yellow protein contains an unidentified chromophore that is bleached by light but recovers within a second. Here we demonstrate that the chromophore is bound covalently to Cys 69 instead of Lys 111 as deduced from the crystal structure analysis. The partially exposed side chains of Tyr 76, 94, and 118, plus Trp 119 appear to be arranged in a cluster and probably become more exposed due to a conformational change of the protein resulting from light-induced chromophore bleaching. The charged residues are not uniformly distributed on the protein surface but are arranged in positive and negative clusters on opposite sides of the protein. The exact chemical nature of the chromophore remains undetermined, but we here propose a possible structure based on precise mass analysis of a chromophore-binding peptide by electrospray ionization mass spectrometry and on the fact that the chromophore can be cleaved off the apoprotein upon reduction with a thiol reagent. The molecular mass of the chromophore, including an SH group, is 147.6 Da (+/- 0.5 Da); the cysteine residue to which it is bound is at sequence position 69.