A neoplastic gene fusion mimics trans-splicing of RNAs in normal human cells     

Li H  Wang J  Mor G  Sklar J 《Science (New York, N.Y.)》2008,321(5894):1357-1361

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Legionella effectors that promote nonlytic release from protozoa     

Chen J  de Felipe KS  Clarke M  Lu H  Anderson OR  Segal G  Shuman HA 《Science (New York, N.Y.)》2004,303(5662):1358-1361

Legionella pneumophila, the bacterial agent of legionnaires' disease, replicates intracellularly within a specialized vacuole of mammalian and protozoan host cells. Little is known about the specialized vacuole except that the Icm/Dot type IV secretion system is essential for its formation and maintenance. The Legionella genome database contains two open reading frames encoding polypeptides (LepA and LepB) with predicted coiled-coil regions and weak homology to SNAREs; these are delivered to host cells by an Icm/Dot-dependent mechanism. Analysis of mutant strains suggests that the Lep proteins may enable the Legionella to commandeer a protozoan exocytic pathway for dissemination of the pathogen.  相似文献   

The genomic sequence of the accidental pathogen Legionella pneumophila     

Chien M  Morozova I  Shi S  Sheng H  Chen J  Gomez SM  Asamani G  Hill K  Nuara J  Feder M  Rineer J  Greenberg JJ  Steshenko V  Park SH  Zhao B  Teplitskaya E  Edwards JR  Pampou S  Georghiou A  Chou IC  Iannuccilli W  Ulz ME  Kim DH  Geringer-Sameth A  Goldsberry C  Morozov P  Fischer SG  Segal G  Qu X  Rzhetsky A  Zhang P  Cayanis E  De Jong PJ  Ju J  Kalachikov S  Shuman HA  Russo JJ 《Science (New York, N.Y.)》2004,305(5692):1966-1968

We present the genomic sequence of Legionella pneumophila, the bacterial agent of Legionnaires' disease, a potentially fatal pneumonia acquired from aerosolized contaminated fresh water. The genome includes a 45-kilobase pair element that can exist in chromosomal and episomal forms, selective expansions of important gene families, genes for unexpected metabolic pathways, and previously unknown candidate virulence determinants. We highlight the genes that may account for Legionella's ability to survive in protozoa, mammalian macrophages, and inhospitable environmental niches and that may define new therapeutic targets.  相似文献   

Cross-linking cellular prion protein triggers neuronal apoptosis in vivo     

Solforosi L  Criado JR  McGavern DB  Wirz S  Sánchez-Alavez M  Sugama S  DeGiorgio LA  Volpe BT  Wiseman E  Abalos G  Masliah E  Gilden D  Oldstone MB  Conti B  Williamson RA 《Science (New York, N.Y.)》2004,303(5663):1514-1516

Neuronal death is a prominent, but poorly understood, pathological hallmark of prion disease. Notably, in the absence of the cellular prion protein (PrPC), the disease-associated isoform, PrPSc, appears not to be intrinsically neurotoxic, suggesting that PrPC itself may participate directly in the prion neurodegenerative cascade. Here, cross-linking PrPC in vivo with specific monoclonal antibodies was found to trigger rapid and extensive apoptosis in hippocampal and cerebellar neurons. These findings suggest that PrPC functions in the control of neuronal survival and provides a model to explore whether cross-linking of PrPC by oligomeric PrPSc can promote neuronal loss during prion infection.  相似文献   

The paradox of the conservation of an endangered fish species in a Mediterranean region under agricultural intensification     

J. Jesús Casas  Juan S. Sánchez-Oliver  Ana Sanz  Miriam Furné  Cristina Trenzado  Melchor Juan  Mariano Paracuellos  María D. Suárez  Francisca Fuentes  Irene Gallego  Carlos Gil  José J. Ramos-Miras 《Biological conservation》2011,(1):253-262

We studied the relative value of natural habitats, river and coastal wetlands, and artificial habitats, irrigation canal and ponds, for the conservation of an endangered fish, Iberian toothcarp, in its southernmost area of distribution, characterised by agricultural intensification. Our results show that the bulk of the population of the Iberian toothcarp is concentrated in irrigation ponds. Natural habitats sustained null or impoverished subpopulations, and individuals showed signs of low metabolic activity. This coincided with the relatively high habitat quality observed in ponds, particularly those with submerged aquatic vegetation, in contrast with the chronic eutrophication of the coastal lagoons. In spite of a generalised aggressive management in the irrigation system, featured by periodic vegetation clearance, desiccation and biocide treatment, the subpopulation of the Iberian toothcarp thrives in it probably thanks to adequate water quality and to an active path dynamics maintained by connectivity through the canal. Agro-environmental measures are discussed for the improvement of this species conservation in natural and artificial habitats.  相似文献   

Two new species of Clestobothrium (Cestoda: Bothriocephalidea), parasites of Merluccius australis and m. hubbsi (Gadiformes: Merlucciidae) from the Patagonian shelf of Argentina, with comments on Clestobothrium crassiceps (Rudolphi, 1819)     

de Pertierra AA  Incorvaia IS  Arredondo NJ 《Folia parasitologica》2011,58(2):121-134

Abstract: Two new species of bothriocephalidean cestodes, Clestobothrium splendidum sp. n. from Merluccius australis (Hutton) and Clestobothrium cristinae sp. n. from Merluccius hubbsi Marini from the Patagonian shelf of Argentina, are described. Clestobothrium splendidum can be typified by the following characteristics: a medium-sized strobila composed of410-528 proglottides that are much wider than long; 49-90 testes per mature proglottis, partially surrounding the ovary posteriorly; a transversely elongated genital pore situated anterior to spurious articulations; presence of a genital atrium; a globular cirrus-sac occupying 4-6% of mature proglottis width; a vagina with sphincter and three pairs of osmoregulatory canals on each side of the proglottis. Clestobothrium cristinae is characterised by its small size; 71-219 proglottides; 39-64 testes per mature proglottis, usually surrounding completely the ovary posteriorly; a rounded genital pore situated at the same level of spurious articulations; an oval cirrus-sac occupying 8-16% of mature proglottis width; and three pairs of osmoregulatory canals on each side of the proglottis. Clestobothrium cristinae shares with C. splendidum the type and distribution of microtriches, except for the central surface delimited by two lips. Additionally, type and voucher materials of Clestobothrium crassiceps (Rudolphi, 1819) from Merluccius merluccius were studied. A key to species is provided.  相似文献   

High-resolution nuclear magnetic resonance spectroscopy and multivariate analysis for the characterization of beer   总被引：3，自引：0，他引：3  

Duarte I  Barros A  Belton PS  Righelato R  Spraul M  Humpfer E  Gil AM 《Journal of agricultural and food chemistry》2002,50(9):2475-2481

Beer contains a very complex mixture of nutrients, which in this work are identified to some extent by high-field high-resolution nuclear magnetic resonance (NMR) one- and two-dimensional methods. The (1)H NMR spectrum of beer shows a predominance of strongly overlapped peaks arising from several carbohydrates. Minor components are clearly observed both in the aliphatic and in the aromatic regions of the spectrum. With the aid of two-dimensional methods, spectral assignment was carried out, enabling the identification of approximately 30 compounds and identifying about the same number of spin systems for further assignment. The variability of the spectral profile of beers differing in type and label was studied by principal component analysis (PCA), and it was found that, although some distinction is achieved on the basis of the aliphatic and sugar compositions, clearer separation between ales and lagers is obtained by PCA of the aromatic profiles alone. The potential of this technique as a rapid and informative quality control tool is discussed.  相似文献   

High-resolution NMR and diffusion-ordered spectroscopy of port wine     

Nilsson M  Duarte IF  Almeida C  Delgadillo I  Goodfellow BJ  Gil AM  Morris GA 《Journal of agricultural and food chemistry》2004,52(12):3736-3743

The use of high-resolution NMR and high-resolution diffusion-ordered spectroscopy (DOSY) for the characterization of selected Port wine samples of different ages with the aim of identifying changes in composition is described. Conventional 1D and 2D NMR methods enabled the identification of about 35 compounds, including minor components such as some medium-chain alcohols, amino acids, and organic acids. High-resolution (HR) DOSY extended sample characterization, increasing the number of compounds identified and NMR assignments made, by providing information on the relative molecular sizes of the metabolites present. Port wines of different ages were found to differ mainly in their content of (a) organic acids and some amino acids, (b) an unidentified possible disaccharide, and (c) large aromatic species. The relative amount of these last high Mw aromatics is seen to decrease significantly in the oldest wine, as expected from the known formation and precipitation of anthocyanin-based polymers during red wine aging.  相似文献   

Coriander essential oil composition from two genotypes grown in different environmental conditions     

Gil A  De La Fuente EB  Lenardis AE  López Pereira M  Suárez SA  Bandoni A  Van Baren C  Di Leo Lira P  Ghersa CM 《Journal of agricultural and food chemistry》2002,50(10):2870-2877

The objective was to study the essential oil composition of coriander fruits in plants growing in environments differing in soil conditions and weediness level. Factorial field experiments were conducted in two locations from the Rolling Pampas, Argentina, and two coriander landraces (European and Argentinean) were tested under two levels of nitrogen fertilization and weediness. Data were evaluated with uni- and multivariate techniques. The variation in the oil composition was related to the relative proportion of the constituents and not to the presence/absence of a particular component. Weather conditions in 1997 favored linalool and camphor in both landraces. Location, fertilization, and weediness also affected the chemical profile. The European landrace showed a more stable concentration of the major components than the Argentinean landrace. These results, which show the relationships between some environmental conditions and the essential oil composition, are useful in the development of innovative strategies aimed to improve oil composition and to manage crop pests.  相似文献   

Effect of postharvest storage and processing on the antioxidant constituents (flavonoids and vitamin C) of fresh-cut spinach   总被引：7，自引：0，他引：7  

Gil MI  Ferreres F  Tomás-Barberán FA 《Journal of agricultural and food chemistry》1999,47(6):2213-2217

The effect of modified atmosphere packaging (MAP) and cooking on the flavonoids and vitamin C content (ascorbic + dehydroascorbic acid; AA + DHAA) of fresh-cut spinach was evaluated. The total flavonoid content (approximately 1000 mg kg(-)(1) f.w.) remained quite constant during storage in both air and MAP atmospheres, while vitamin C (750 mg kg(-)(1)f.w.) was better preserved in MAP-stored spinach. AA was transformed to DHAA during storage, and its concentration was higher in MAP-stored tissues. The free-radical scavenging activity of the isolated flavonoids was tested, and only those flavonoids with either a dihydroxyl grouping or acylated with ferulic acid showed significant activity. A decrease in the total antioxidant activity was observed during storage, particularly important in MAP-stored spinach. The higher content of DHAA and lower content of both AA and antioxidant flavonoids in the MAP-stored samples could explain this antioxidant activity decrease. Boiling extracted 50% of total flavonoids and 60% vitamin C in the cooking water. However, flavonoid glucuronides were extracted more in the cooking water than the other glycosides. The vitamin C content of the cooked tissue was higher in those samples stored in MAP.  相似文献