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81.
To investigate the impact of averseness, controllability and familiarity of a test situation on the involvement of the endocannabinoid system in the regulation of exploratory behaviour, we tested conventional and conditional cannabinoid receptor type 1 (CB1)-deficient mice in behavioural paradigms with different emotional load, which depended on the strength of illumination and the ability of the animals to avoid the light stimulus. Complete CB1 null-mutant mice (Total-CB1-KO) showed an anxiogenic-like phenotype under circumstances where they were able to avoid the bright light such as the elevated plus-maze and the light/dark avoidance task. Conditional mutant mice lacking CB1 expression specifically in cortical glutamatergic neurons (Glu-CB1-KO), in contrast, failed to show a similar phenotype under the same experimental conditions. However, both mutant lines showed increased avoidance of open arm exploration during a second exposure to the elevated plus-maze. If tested in situations where the fear eliciting light could not be avoided, Total-CB1-KO mice showed increased thigmotaxis in an open field, decreased social investigation and decreased novel object exploration under aversive light conditions, but not under non-aversive low light. This time, Glu-CB1-KO also showed decreased exploratory behaviour towards objects and conspecific juveniles and increased thigmotaxis in the open field. Taking into consideration that the behavioural performance of wild-type mice was only marginally affected by changes in light intensities, these data indicate that the endocannabinoid system renders exploratory behaviour largely independent of the test averseness. This process differentially involves endocannabinoid-controlled glutamatergic transmission, depending on the controllability of the test situation.  相似文献   
82.
A Gram-negative bacterium designated UBF-P1T was isolated from an enrichment culture established in nutrient supplemented artificial sea water with pyrene as a carbon source, and inoculated with a marine fuel oil-degrading consortium obtained from a sand sample collected from the beach of Corrubedo (A Coruña, Galicia, Spain) after the Prestige accidental oil spill. Phylogenetic analysis based on the almost complete 16S rRNA gene sequence affiliated strain UBF-P1T with the family Cohaesibacteraceae, Cohaesibacter gelatinilyticus (DSM 18289T) being the closest relative species with 92% sequence similarity. Cells were irregular rods, motile, strictly aerobic, catalase and oxidase positive. Ubiquinone 10 was the major respiratory lipoquinone. The major polar lipids comprised diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylmonomethylethanolamine (PME), and phosphatidylcholine (PC). The major fatty acids detected were C18:1ω7c, C19:0 cycloω8c, and C16:0. The G + C content of strain UBF-P1T was 63.9 mol%. The taxonomic comparison with the closest relative based on genotypic, phenotypic and chemotaxonomic characteristics supported that strain UBF-P1T could be classified as a novel genus and species, for which the name Breoghania corrubedonensis gen. nov., sp. nov. is proposed. The type strain of this new taxon is UBF-P1T (CECT 7622, LMG 25482, DSM 23382).  相似文献   
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84.
We have synthesized [(125)I]4'-iodoflavone to study Ah receptor (AhR)-ligand interactions by a class of AhR ligands distinct from the prototypic ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). This radioligand allows the comparison of AhR-ligand interactions using a ligand that differs in AhR affinity, and yet has the same radiospecific activity as [(125)I]2-iodo-7,8-dibromodibenzo-p-dioxin. Specific binding of [(125)I]4'-iodoflavone with the AhR was detected as a single radioactive peak ( approximately 9.7 S) following density sucrose gradient analysis. Cytosolic extracts from both Hepa 1 and HeLa cells were used as the source of mouse and human AhR, respectively. A approximately 6.7 S form of radioligand-bound Ah receptor was detected in the high salt nuclear extracts of both cell lines. In HeLa cells approximately twofold more [(125)I]4'-iodoflavone-AhR 6 S complex, compared with [(125)I]2-iodo-7,8-dibromodibenzo-p-dioxin, was recovered in nuclear extracts. A comparison of the ability of 4'-iodoflavone and TCDD to cause time-dependent translocation of AhR-yellow fluorescent protein revealed that 4'-iodoflavone was more efficient at enhancing nuclear accumulation of the receptor. These results suggest that [(125)I]4'-iodoflavone is a particularly useful and easily synthesized ligand for studying the AhR.  相似文献   
85.
硫代反义寡核苷酸在细胞培养内抗甲型流感病毒活性   总被引:5,自引:0,他引:5  
陈忠斌  王升启 《病毒学报》1998,14(3):193-198
为了研究抗流感病毒特异性反义核酸药物,针对A型流感病毒基因组3'和5'端保守序列,设计并合成了4条硫代寡核苷酸(ODN):3'端反义ODN(IV3^#)与3'端正义ODN(IV3S),5'端反义ODN(IV4^#)与5'端正交ODN(IV4S)。以流感病毒血凝滴度和致细胞病变作用为指标,测定了ODNs在MDCK细胞中对A型流感病毒A/京防/86-1(H1N1)复制的影响。结果表明,与流感病毒基因组  相似文献   
86.
Summary The Triassic sediments in the subsurface of the United Arab Emirates has been divided into three formations (from bottom to top): Sudair, Jilh (Gulailah) and Minjur. The Sudair Formation consists of four lithofacies units composed mainly of limestones and minor dolomites interbedded with terrigenous shaley mudstones and anhydritic dolomitic limestones. These were deposited in shallow marine supratidal to subtidal settings. The Jilh (Gulailah) Formation has five lithofacies units dominated by anhydritic dolomitic limestone, fine terrigenoclastic sediments and bioclastic and intraclastic limestones. The formation was laid down under lagoonal to supratidal sabkha conditions with little normal marine influence. The Minjur Formation is composed of three lithofacies units characterized by argillaceous quartzitic sandstones, shales, mudstones, dolomitic and ferruginous limestones with thin coal seams. These facies represent deposition in prograding delta lobes, reflecting humid continental to marginal-marine conditions. Diagenesis plays a major role in the reservoir development in the Triassic sediments, the pores are occluded by dolomite and anhydrite. The grains are compacted, leached or cemented by marine cements. Porosity generally ranges from fair to poor with values from 6% to 9% in the carbonates and from 6% to 15% in the clastics. Interparticle and vuggy porosities are the main pore types. The porosity was controlled by diagenesis, depth of burial and lithology. No oil has been discovered so far in the Triassic sediments of the United Arab Emirates but pronounced gas shows have been reported from offshore fields. Western offshore United Arab Emirates is a promising area for potential hydrocarbon accumulations. The Triassic sediments have low to moderate source rock potential; the organic matter is mainly sapropelic kerogen, and the degree of thermal alteration ranges between mature to highly mature stages.  相似文献   
87.
Living microplanktonic blue-green alga Oscillatoria tenuis has been cultured in the laboratory as experimental material. The chemical analysis showed that the weight of liposoluble organic matter in O. tenuis was 5.8% of dry cell and the amounts of pigments were more over than those of aliphatic hydrocarbons. The distribution of hydrocarbons in O. tenuis indicated that a dominance of normal alkanes between n-C14 and n-C19, while a maximum at n-C17.The pigments, such as demagnesium chlorophyll a, β-carotene and an unknown orange-red pigment have been measured in the alcohol fraction and benzene fraction of liposoluble compounds on column chromatography. The research of liposoluble compounds, especially aliphatic hydrocarbons in blue-green algae is valuable to understand them as original materials for the organic matter found in ancient sediments.  相似文献   
88.
The prevailing assumption in the primate literature is that young or juvenile primates are more innovative than adult individuals. This innovative tendency among the young is frequently thought to be a consequence, or side effect, of their increased rates of exploration and play. Conversely, Reader and Laland's [International Journal of Primatology 22:787-806, 2001] review of the primate innovation literature noted a greater reported incidence of innovation in adults than nonadults, which they interpreted as (in part) a reflection of the greater experience and competence of older individuals. Within callitrichids there is contradictory evidence for age differences in response to novel objects, foods, and foraging tasks. By presenting novel extractive foraging tasks to family groups of callitrichid monkeys in zoos, we examined, in a large sample, whether there are positive or negative relationships of age with neophilia, exploration, and innovation, and whether play or experience most facilitates innovation. The results indicate that exploration and innovation (but not neophilia) are positively correlated with age, perhaps reflecting adults' greater manipulative competence. To the extent that there was evidence for play in younger individuals, it did not appear to contribute to innovation. The implications of these findings for the fields of innovation and conservation through reintroduction are considered.  相似文献   
89.
The C57BL/6JOlaHsd and 129S2/SvHsd mice were tested in a battery designed for behavioral phenotyping of genetically modified mice. The study was performed in order to reveal the effect of training history on the behavior by comparison with the experimentally naïve mice in the same tests. Significant strain differences were obtained in all experiments. Previous handling and testing reduced exploratory activity and emotionality significantly in the mice. The coordination ability was better and nociceptive sensitivity was increased in the trained mice. The contextual fear was reduced whereas the cued fear was enhanced in the experienced mice. The training history did not alter initial learning in the water maze. However, after reversal learning the naïve mice displayed significant preference for both old and new platform locations, whereas the battery animals did not exhibit preference to the old location. The experienced mice appeared to be less active in the forced swimming test and exhibited decreased conditioned taste aversion. The influence of test history was strain-dependent in certain cases. Therefore, the experience has substantial consequences on the behavior, mainly by reducing exploratory activity, and the previous experience of the animals has always to be considered in the analysis of genetically modified mice.  相似文献   
90.
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