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951.
Over the last decade the zebrafish has emerged as a major genetic model organism. While stimulated originally by the utility of its transparent embryos for the study of vertebrate organogenesis, the success of the zebrafish was consolidated through multiple genetic screens, sequencing of the fish genome by the Sanger Center, and the advent of extensive genomic resources. In the last few years the potential of the zebrafish for in vivo cell biology, physiology, disease modeling and drug discovery has begun to be realized. This review will highlight work on cardiac electrophysiology, emphasizing the arenas in which the zebrafish complements other in vivo and in vitro models; developmental physiology, large-scale screens, high-throughput disease modeling and drug discovery. Much of this work is at an early stage, and so the focus will be on the general principles, the specific advantages of the zebrafish and on future potential. 相似文献
952.
Siloto RM Madhavji M Wiehler WB Burton TL Boora PS Laroche A Weselake RJ 《Biochemical and biophysical research communications》2008,373(3):350-354
A histidine-tagged recombinant N-terminal fragment of type-1 mouse liver diacylglycerol acyltransferase (DGAT; EC 2.3.1.20), MmDGAT1(1-95)His6, was expressed in Escherichia coli, and used to investigate possible acyl-CoA-binding properties. Analysis of the purified fragment by MALDI-TOF mass spectrometry revealed a polypeptide with molecular mass of about 11 kDa which was consistent with the calculated molecular mass based on the deduced amino acid sequence. Lipidex-1000 binding assays indicated that MmDGAT1(1-95)His6 interacted with long chain fatty acyl-CoAs similar to observations on DGAT1 from oilseed rape (Brassica napus). Binding, as a function of acyl-CoA concentration, differed for palmitoyl (16:0), stearoyl (18:0), and erucoyl (cisΔ1322:1)-CoA. Binding of stearoyl- or erucoyl-CoA to MmDGAT1(1-95)His6 as a function of acyl-CoA concentration, however, was sigmoid and displayed positive cooperativity suggesting that MmDGAT1 may be subject to allosteric modulation by acyl-CoAs. An intra-polypeptide segment within the N-terminal region of MmDGAT1 contained remnants of an acyl-CoA-binding signature initially identified in plant DGAT1. The acyl-CoA-binding site in mammalian DGAT1 could represent a potential target for therapeutic interventions for disorders such as type-2 diabetes and obesity. 相似文献
953.
Guilherme Maranhão Chaves Mariana Guimarães Diniz Walicyranison Plinio da Silva-Rocha Luanda Bárbara Ferreira Canário de Souza Libia Augusta Maciel Gondim Maria Angela Fernandes Ferreira Terezinha Inez Estivalet Svidzinski Eveline Pipolo Milan 《Mycopathologia》2013,175(3-4):255-263
Although yeasts belonging to the genus Candida are frequently seen as commensals in the oral cavity, they possess virulence attributes that contribute for pathogenicity. The aims of the present study were to study the prevalence of Candida spp. isolated from the oral cavity of renal transplant recipients and to analyze strains virulence factors. We isolated a total of 70 Candida strains from 111 transplant recipients, and Candida albicans was the most prevalent species (82.86 %). Oral candidiasis was diagnosed in 14.4 % kidney transplant patients, while 11 isolates (15.7 %) corresponded to non-Candida albicans Candida (NCAC) species. C. albicans adhered to a higher extension than NCAC strains. Some isolates of Candida tropicalis were markedly adherent to human buccal epithelial cells and highly biofilm-forming strains. Regarding proteinase activity, Candida orthopsilosis was more proteolytic than Candida metapsilosis. Candida glabrata and Candida dubliniensis showed very low ability to form biofilm on polystyrene microtiter plates. We have demonstrated here diverse peculiarities of different Candida species regarding the ability to express virulence factors. This study will contribute for the understanding of the natural history and pathogenesis of yeasts belonging to the genus Candida in the oral cavity of patients who were submitted to kidney transplant and are under immunosuppressive therapies. 相似文献
954.
Melampyrum pratense is one of the most successful root-hemiparasitic species of temperate Europe occurring in various habitats including both forest and open communities. The species shares its life history traits (large seeds, annuality, lack of clonality) with most of other hemiparasitic Orobanchaceae. Due to lack of vegetative propagation, the reproductive success of a M. pratense individual largely depends on the seed production. We used an individual-based observation of ontogenetic development of plants and analysed the development of spatial distribution of individuals to reveal links between fecundity of individuals and their vegetative growth in the context of population dynamics within one growing season. We demonstrated a tight dependency of seed production on vegetative growth and survival till the end of the growing season. Plants that were still alive and big (due to a high number of lateral branches) in the end of August produced the highest numbers of seeds. These were several times higher than the population average due to positively skewed distribution of seed production across individuals. The rate of premature mortality was rather low (below 50%) once seedlings successfully emerged and was most likely caused by intraspecific competition. By contrast, moderate level of herbivory (stem clipping by grazers) had a limited effect on the survival and the inflicted biomass losses seemed compensated. Therefore, despite being an annual, M. pratense appears well-adapted to its life in perennial-dominated forest communities, which is also underpinned by its hemiparasitic strategy providing essential resources and allowing to avoid below-ground competition. 相似文献
955.
Koci J Movila A Taragel'ová V Toderas I Uspenskaia I Derdáková M Labuda M 《Experimental & applied acarology》2007,41(1-2):147-152
We examined 198 questing Ixodes ricinus ticks collected in Chisinau City, Republic of Moldova by PCR assays for Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and co-infection of both pathogens, which were detected in 9%, 25.2% and 2.5% of tested ticks, respectively. B. burgdorferi s.l. genotyping revealed the presence of five genospecies with dominance of B. garinii. Our preliminary study provides evidence about occurrence of both pathogens in this populated area, which represent a potential
health risk for inhabitants. 相似文献
956.
Horak D Babic M Jendelová P Herynek V Trchová M Pientka Z Pollert E Hájek M Syková E 《Bioconjugate chemistry》2007,18(3):635-644
New surface-modified iron oxide nanoparticles were developed by precipitation of Fe(II) and Fe(III) salts with ammonium hydroxide according to two methods. In the first method, precipitation was done in the presence of D-mannose solution (in situ coating); the second method involved oxidation of precipitated magnetite with sodium hypochlorite followed by addition of D-mannose solution (postsynthesis coating). Selected nanoparticles were characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), elemental analysis, dynamic light scattering, infrared (IR), X-ray powder analysis, and ultrasonic spectrometry. While the first preparation method produced very fine nanoparticles ca. 2 nm in diameter, the second one yielded ca. 6 nm particles. Addition of D-mannose after synthesis did not affect the iron oxide particle size. UV-vis spectroscopy suggested that D-mannose suppresses the nonspecific sorption of serum proteins from DMEM culture medium on magnetic nanoparticles. Rat bone marrow stromal cells (rMSCs) were labeled with uncoated and d-mannose-modified iron oxide nanoparticles and with Endorem (Guerbet, France; control). Optical and transmission electron microscopy confirmed the presence of D-mannose-modified iron oxide nanoparticles inside the cells. D-mannose-modified nanoparticles crossed the cell membranes and were internalized well by the cells. Relaxivity measurements of labeled cells in gelatin revealed very high relaxivities only for postsynthesis D-mannose-coated iron oxide nanoparticles. 相似文献
957.
958.
959.
Zdeňka Lososová Michal Horsák Milan Chytrý Tomáš Čejka Jiří Danihelka Karel Fajmon Ondřej Hájek Lucie Juřičková Kateřina Kintrová Deana Láníková Zdenka Otýpková Vladimír Řehořek Lubomír Tichý 《Journal of Biogeography》2011,38(6):1152-1163
Aim Urbanization is associated with strong changes in biodiversity, but the diversity of plant and animal assemblages varies among urban habitats. We studied effects of urban habitats on the diversity of vascular plants and land snails in 32 large cities. Location Central Europe, Belgium and the Netherlands. Methods The species composition of all vascular plants that had not been planted by humans, and all land snails, was recorded in seven 1‐ha plots within each city. Each plot contained one urban habitat type representing a different disturbance regime: historical city square, boulevard, residential area with compact building pattern, residential area with open building pattern, park, early successional and mid‐successional site. For each plot, we obtained temperature and precipitation data. The effects of climate and habitat types on species composition were quantified using ordination methods with an adjusted variation partitioning algorithm. Differences in species composition among urban habitats were described using statistically determined diagnostic species, and differences in alpha, beta and gamma diversity were quantified. Results A total of 1196 plant and 87 snail species were recorded. Habitat type explained higher proportions of the total variation in both plant and snail species composition (11.2 and 8.2%, respectively) than did climate (4.6 and 6.3%). For both taxa, the main differences in species composition were observed between strongly urbanized sites in city centres and early successional and mid‐successional sites. For vascular plants, the number of species was lowest in city squares and boulevards, and highest at successional sites and in residential areas with compact building patterns. Beta diversity of vascular plants calculated for the same habitat types among cities was highest for squares and successional sites. The number of snail species was lowest in city squares and at early successional sites, and highest at mid‐successional sites. The highest beta diversity of snail assemblages among cities was observed within the city square and early successional habitat types, and the lowest within residential area habitat types. Main conclusions Urban habitats differ notably in the diversity of their vascular plant flora and land snail fauna. Understanding the habitat‐related biodiversity patterns in urbanized landscapes will allow projections of future impacts of urban land‐use changes on the biota. 相似文献
960.
Flavie Tortereau Marie-Pierre Sanchez Katia Fève Hélène Gilbert Nathalie Iannuccelli Yvon Billon Denis Milan Jean-Pierre Bidanel Juliette Riquet 《BMC genetics》2011,12(1):1-12