Alterations in Oxidative Markers in the Cerebellum and Peripheral Organs in MPS I Mice

Mucopolysaccharidosis type I is a lysosomal storage disease with alterations in several organs. Little is known about the pathways that lead to the pathology. Evidences point oxidative stress on lysosomal storage diseases and mucopolysaccharidosis type I. The aim of the present study was to evaluate oxidative biomarkers on mucopolysaccharidosis type I mice model. We evaluated antioxidant enzymatic activity, protein damage and lipid peroxidation in the forebrain, cerebellum, heart, lung, diaphragm, liver, kidney and spleen. Superoxide dismutase activity was increased on cerebellum, lung, diaphragm, liver and kidney of mucopolysaccharidosis type I mice. Catalase activity was increased on cerebellum, spleen and lung. There was no alteration on glutathione peroxidase activity on any of the analyzed organs. Mucopolysaccharidosis type I mice showed increased carbonyl groups on cerebellum, heart and spleen. There was a decrease of thiobarbituric acid-reactive substances on the cerebellum of mucopolysaccharidosis type I mice. The results indicate a oxidative imbalance in this model. As lysosomes are very susceptible to oxidative damage, leading inclusive to cellular death, and lysosomal storage diseases present several alterations on this organelles, this finding can help to elucidate the cellular damage pathways on mucopolysaccharidosis type I.     

Survival of Fungi in Hyperbaric Oxygen in Relation to Changes in Catalase Activity

Survival of replacement cultures of Mucor species in oxygenat 10 atm was markedly affected by the carbon source; culturesreplaced on glucose media survived for a much shorter periodthan cultures on water while 1 per cent ethanol increased thesurvival time. This effect of carbon source on survival wascorrelated with changes in catalase activity; in the presenceof glucose and other carbohydrates, catalase activity decreasedwhereas on 1 per cent ethanol a large increase in catalase activityoccurred which was maintained for several days. An increasein catalase activity also occurred on methanol, pyruvate, glycerol,and formate. Induced changes in peroxidase activity were similarto those shown by catalase but the activity of three other enzymesdecreased in hyperbaric oxygen on all media.     

Differences in Renal Clearances Measured in Danish Pigs

Measurements are reported of renal clearances of inulin, endogenous creatinine, urea and PAH in 15 pigs in order to elucidate (a) the effect of pentobarbitone and urethane on the renal clearances, (b) differences in clearances measured by continuous infusion and by subcutaneous injection, (c) the effect of the intensity of feeding on the renal clearances, and (d) the difference in the renal clearances between two strains of Danish Landrace pigs. Sedation with pentobarbitone and urethane had no effect on the renal clearances of the pigs. Measurement of clearances by continuous infusion gave the same results as use of the subcutaneous injection method. Changes in the intensity of feeding and the consequent effect on growth had no influence on the renal clearances or on the relative kidney weight. Considerable differences were demonstrated in the renal function of pigs from two different strains of Danish Landrace Pigs.     

Enzymology of DNA in replication in prokaryotes

This review stresses recent developments in the in vitro study of DNA replication in prokaryotes. New insights into the enzymological mechanisms of initiation and elongation of leading and lagging strand DNA synthesis in ongoing studies are emphasized. Data from newly developed systems, such as those replicating oriC containing DNA or which are dependent on the lambda, O, and P proteins, are presented and the information compared to existing mechanisms. Evidence bearing on the coupling of DNA synthesis on both parental strands through protein-protein interactions and on the turnover of the elongation systems are analyzed. The structure of replication origins, and how their tertiary structure affects recognition and interaction with the various replication proteins is discussed.     

植物的功能基因组学研究进展

基因组研究计划包括以全基因组测序为目标的结构基因组学和以基因功能鉴定为目标的功能基因组学两方面的内容。目前基因功能鉴定的方法主要有：基因表达的系统分析(SAGE)、cDNA微阵列、DNA(基因)芯片、蛋白组技术以及基于转座子标签和T_DNA标签的反求遗传学技术等。本文对上述各种技术的优缺点以及它们在植物基因功能鉴定中的应用进行了综述。 Abstract: The genome projects comprise the structural genomics focusing on determining the complete sequences of the genome and the functional genomics focusing on elucidating the biological function of genes.The rapidly evolving tools for functional genomics research include Serial Analysis of Gene Expression (SAGE),cDNA microarray,DNA (or gene) chips,proteome project and the reverse genetics technique based on the well-established transposon tagging and T?DNA tagging systems.In this paper,the advantages and disadvantages of such techniques and application of these techniques in plant functional genomics research are reviewed and future prospective are also presented.     

热泉微生物驱动的氮循环研究进展及展望

热泉微生物是驱动热泉氮(N)循环的主导力量,开展热泉生态系统中驱动氮循环微生物种群构成及其与环境响应的研究,对于探索热泉中氮的生物地球化学循环、生命进化、生物修复等方面都具有重要的理论和应用价值。本文综合阐述了热泉生态系统驱动氮循环的功能微生物(如固氮菌、氨氧化菌、厌氧氨氧化菌、反硝化菌、异化硝酸盐还原菌)在系统发育学上的分布、功能基因的相对丰度、活性及其与环境因子(如温度、pH)的相关性等方面的研究现状和亟待解决的问题。并展望了热泉生境中驱动氮循环微生物未来的研究方向。     

Alterations in collagen metabolism in heart and kidney on dexamethasone administration in rats

Total collagen content in heart decreased significantly till day 8 of dexamethasone (Dex: 2.5 mg/kg week; s.c. for 2 weeks) treatment and increased on withdrawal of Dex. Acid soluble collagen content in heart decreased till day 12 of Dex treatment, reached normal level on day 16 of Dex treatment and exhibited an increase thereafter. Pepsin solubilized fraction in heart also behaved similarly as the acid soluble fraction, but reached normal level on Dex withdrawal. The total collagen content and the acid soluble collagen in kidney decreased significantly throughout treatment as well as on Dex withdrawal whereas, the pepsin solubilized collagen fraction in kidney exhibited a significant increase from day 8 of Dex treatment and the level was maintained throughout the experiment. Incorporation of 14C-proline in both, heart and kidney was found to be reduced. Electrophoretic pattern of pepsin collagen solubilized fraction of heart and kidney revealed alterations in subunit composition and its types on Dex administration and withdrawal. Thus, administration of Dex induced alterations in the metabolism of collagen and on Dex withdrawal, the system slowly tended to attain normalcy.     

Diet of raccoon dogs in summer in the Finnish archipelago

The diet of raccoon dogs in summer was examined in the Finnish archipelago and compared with their diet on the mainland. Faeces were collected from latrines in the outer archipelago and the inhabited islands in May-July 1998 and 1999. Remains of waterfowl, especially those of female cider, occurred frequently in the faeces of raccoon dogs on the uninhabited islands, but less frequently on the inhabited islands and only occasionally on the mainland. Since many female eider died of disease during the summer in 1998 and 1999. and white-tailed eagles arc known to prey on brooding eider, it is probable that raccoon dogs did not themselves kill all the eider they consumed. Even if they did, they would only take a few percent of female eider population each year. It is thus improbable that raccoon dogs affect the size of the eider population in the Finnish archipelago. Frogs, reptiles, shrews and carrion occurred frequently in the diet on the mainland, but only occasionally in the outer archipelago. It is possible that raccoon dogs have decimated frog populations on small islands, as they are easy prey and occur frequently in the diet of raccoon dogs on the mainland. Small rodents are important prey for raccoon dogs on the mainland and on inhabited islands, but less important in the outer archipelago in early summer.     

我国卫矛科杀虫植物研究进展

卫矛科植物由于具有独特的生物活性而受到广泛关注。作者主要综述了我国对卫矛科杀虫植物的研究进展。迄今为止,该科植物中发现的主要杀虫成分均是以二氢沉香呋喃为骨架的多元醇酯和生物碱。就杀虫活性而言,主要是对昆虫拒食作用的测定,仅对苦皮藤(Celastrus angulatus)和雷公藤(Tripterygium wilfordii)杀虫成分的毒杀、麻醉等胃毒作用的研究比较系统深入。此外,也对当前这些研究中存在的问题及前景进行了分析。     

Problems in maintaining hybridomas in vivo

The literature data on the regularities of the manifestation of tumorigenic capacity in somatic hybrids, on the correlation of this sign with the features of the in vitro transformation of hybrid cells, on the chromosomal stability and taking capacity of hybridomas have been analyzed. The expediency of the inoculation of animals with hybridomas, made considerably earlier than required by the traditional scheme of obtaining monoclonal antibodies, with a view to the selection of tumorigenic hybridoma variants is suggested. The aims of the experimental work have been determined.     

Diversity in surface colonization behavior in marine bacteria

Using laminar flow chambers and time-lapse video imaging, colonization of surfaces by four marine bacteria revealed a diverse range of morphological characteristics and cell-cell interactions. The strain SW5 formed a compact, multilayered single- and double-cell biofilm on hydrophobic surfaces but developed long multicellular chains on hydrophilic surfaces. The morphologically similar SW8 showed unusual proximal vertical packing of cells on both substrata.Vibrio sp strain S14 exhibited cyclical colonization-detachment events on both substrata.Pseudomonas sp strain S9 initially displayed reversible and then irreversible adhesion apparently triggered by a cell density phenomenon that led to the development of regular microcolonies on both substrata with individual cells translocating between the colonies. The length of time bacteria were exposed to and their density at a surface influenced behavioral traits, with diverse and distinctive species-specific behavioral events.     

Changes in pulsatile LH secretion after ovariectomy in Ile-de-France ewes in two seasons

Two experiments were conducted in Ile-de-France ewes to study changes in pulsatile LH secretion in ewes ovariectomized during anoestrus or during the midluteal phase of the oestrous cycle. In Exp. 1, blood samples were taken every 20 min for 12 h the day before ovariectomy (Day 0). After ovariectomy, samples were taken every 10 min for 6 h (10 ewes per group), on Days 1, 3, 7 and 15. In Exp. 2 samples were taken every 10 min for 6 h (10 ewes per group) on Days 7, 15, 30, 60, 90, 120, 150 and 180 after ovariectomy. Further samples were taken (5 ewes per group) at 9 and 12 months after ovariectomy. There were significant interactions between season and day of sampling for the interval between LH pulses in both experiments. LH pulse frequency increased within 1 day of ovariectomy and the increase was more rapid during the breeding season. There were clear seasonal differences in pulse frequency in Exp. 2. Compared with ewes ovariectomized in anoestrus, pulse frequency was significantly higher for ewes ovariectomized in the breeding season, from Day 7 until Day 120. Once pulse frequency had increased in ewes about the time of the normal breeding season, pulse frequency remained high and subsequent seasonal changes were greatly reduced. Pulse amplitude increased immediately after ovariectomy to reach a maximum on Day 7 and there were no differences between season of ovariectomy in the initial changes in amplitude. In Exp. 2, changes in amplitude followed changes in pulse interval and there was a significant interaction between season and day of sampling. There were no significant effects of season on nadir LH concentrations which increased throughout the duration of the experiments. These results show that, in ovariectomized ewes, LH pulse frequency observed on a given day depends on time after ovariectomy, season at the time of sampling and on previous exposure of ewes to stimulatory effects of season. The direct effects of season on LH pulse frequency and seasonal changes in sensitivity to steroid feedback may contribute to control of the breeding season and their relative contributions to the beginning and end of the breeding season may differ.     

Differences in morphology in relation to microhabitat in littorinid species from a mangrove in Papua New Guinea (Mollusca: Gastropoda)

Field studies on the north coast of Papua New Guinea show that there are three species in the Littorina scabra complex on mangroves. Two are restricted to root structures, while the third occurs on the leaves. The species differ in shell shape, ornamentation and colour, in penis shape, and in radula morphology. The shells of the leaf species are much weaker than those from the roots. Many of the differences observed may be adaptive on the preferred substratum.     

The role of ant nest-mounds in maintaining small-scale patchiness in dry grasslands in Central Germany

Nest-mounds of Lasius flavus, Lasius alienus and Formica rufibarbis are mainly on north-facing slopes with a markedly patchy distribution at Gimritz, northwest of Halle (Saale). Nest-mound soils had higher sodium and potassium levels but lower phosphorus and nitrogen levels than soils away from mounds. Moisture content was lower but soil pH was significantly higher in nest-mound soils. However, there was no difference in the relative abundance of plants of alkaline or acid soils growing on mounds compared to plants off mounds and no significant difference between the numbers of nitrophilous plants on and off mounds. Fewer plant species (35 spp.) in total occurred on mounds than off mounds (42 spp.). Plant species richness and total plant cover was significantly less on the nest-mounds than off the mounds. Similarly, the mean number of grass (1.39 spp dm−2) and forb species (1.13 spp dm−2) on mounds was lower than the mean number of grass (1.99 spp dm−2) and forb species (1.91 spp dm−2) off mounds. Some shrubs and forbs had higher occurrence and cover on the mounds, although only in Calluna vulgaris, Thymus serpyllum and Cerastium arvense was this difference particularly marked. Ant nest-mounds may favour plant species that cannot compete with tall grasses on unmanaged, set-aside meadows. This revised version was published online in November 2006 with corrections to the Cover Date.     

Biology Teaching in Secondary Schools in France

The educational design of a project option in an Open University course on evolution, based on the use of a computer simulation of natural selection, is discussed and the simulation itself described.     

农林复合系统种间关系研究进展

种间相互作用在很大程度上决定了农林复合系统的生产力和可持续性,理解种间相互作用是经营和管理农林复合系统的关键。地上部分相互作用主要包括复合系统组分对光的竞争与互利、小气候的改变对系统生产力的影响;地下部分相互作用主要包括复合系统组分对水分和养分资源的竞争与互利、固氮树种对系统生产力的影响以及化感作用。今后需加强不同立地条件下的不同农林复合系统种间关系的比较、农林复合系统组分的空间分布格局、化感作用以及农林复合系统种间关系模型等研究。     

Insulin receptors in virus-induced diabetes mellitus in mice

Quantitative estimations were made of insulin receptors on liver cell membrane of DBA/2 mice infected with M variant of encephalomyocarditis virus. The virus produced an impairment of glucose metabolism on day 3 of infection, which lasted for 5 months. The fasting plasma insulin concentration was markedly decreased on day 14. The specific binding of 125-I insulin to the membrane receptor was significantly decreased on day 3 of infection. The binding inhibitions were stronger in male mice than in females. The number of insulin receptors began to decrease on day 1, was decreased remarkably by day 3, and returned on day 7 to the level before infection. A decrease of receptor affinity was also observed in infected animals. These results seem to show that changes in insulin receptors are one cause of the impairment of glucose metabolism in the initial phase of virus-induced diabetes.     

The role of beta 1 integrin in spreading and myofibrillogenesis in neonatal rat cardiomyocytes in vitro.

The influence of the extracellular matrix (ECM) on cell behavior, myofibrillogenesis and cytoarchitecture was investigated in neonatal rat cardiac myocytes in vitro. Cell behavior was examined by analyzing cell spreading on different ECM components under a variety of experimental conditions. Area measurements were made on digitized images of cells grown for various time intervals on fibronectin (FN), laminin (LN), collagens I and III (C I+III), plastic, and bovine serum albumin (BSA). The amount of spreading was varied on the different matrices and was maximal on FN greater than LN greater than C I+III greater than plastic greater than BSA. Addition of anti-beta 1 integrin antibodies to myocytes cultured on FN, LN and C I+III blocked spreading outward on the substrates and altered normal myofibrillogenesis, especially on LN. Concomitantly, the integrin antibodies induced the formation of giant pseudopodial processes which protruded upward from the substrates. These pseudopods contained actin polygonal networks which exhibited a regular geometrical configuration. Effects of the ECM on cytoarchitecture was examined by analyzing the temporal and spatial patterns of fluorescence and immunogold labeling of cytoskeletal and integrin proteins as myocytes spread in culture. The first indication of sarcomeric patterns was the appearance at 4 hours of striations formed by lateral alignment of alpha-actinin aggregates into Z bands. At later times, vinculin at 8 hours and beta 1 integrin at 22 hours became co-localized with alpha-actinin at the Z bands and focal adhesions. These data indicate that ECM components influence myocyte spreading and that myofibril assembly and/or stability is associated with ECM-integrin-cytoskeleton associations.     

基因敲除技术在微生物中的应用

随着分子生物学技术的发展,基因敲除技术越来越广泛地应用于动植物、微生物领域,成为研究生物基因功能最有力的工具之一。基因敲除技术在改造动植物、微生物基因组、研究发育生物学、鉴定新基因新功能、育种以及医疗领域都有应用价值。针对微生物方面,对实现基因敲除的各种原理方法,RecA系统同源重组法, Red系统同源重组法,基于自杀载体的同源重组法,基于温敏型质粒的同源重组法, CRISPR/Cas系统介导的基因敲除方法进行了总结,比较各自的优缺点,并提供一些成功案例以及各种方法相关的发明专利,以期对了解基因敲除技术的方法与发展提供参考。     

水蕨性别决定研究进展

介绍了成精子囊素、赤霉素、培养密度等环境因素对水蕨性别决定的影响以及和水蕨性别决定有关的遗传学和分子生物学研究,概述了以水蕨为材料研究植物性别决定的优势及研究意义,明确了水蕨作为研究植物性别决定的模式植物的地位。