Leishmania tropica experimental infection in the rat using luciferase-transfected parasites     

Talmi-Frank D  Jaffe CL  Nasereddin A  Baneth G 《Veterinary parasitology》2012,187(1-2):57-62

Leishmania tropica is the causative agent of zoonotic cutaneous leishmaniasis in different parts of the Old World. Although it is a common cause of disease in some areas of the world, there is insufficient knowledge on the pathogenicity of this parasite in mammalian hosts and animal models. L. tropica luciferase-transfected metacyclic-stage promastigotes were inoculated into the footpad or ear of Sprague Dawley (SD) rats. Parasite DNA was detected by kDNA real time PCR in the blood at varying levels from 2 days to 5 weeks post infection (PI) in the absence of clinical signs. Parasite DNA was found in the spleen of all rats at the end of the study, and the parasitic load was up to 40 times higher in the spleen when compared with inoculation sites. Parasites were cultured from the spleen, and skin inoculation sites 5 weeks PI. Bioluminescent parasites were observed by in vivo imaging at one day PI, but the technique was not sufficiently sensitive to follow parasite spread after this time. This study provides new evidence for the viscerotropic spread of L. tropica in the rat and demonstrates that the rat can serve as a model for persistent visceralizing infection with this parasite.  相似文献   

Self-recognition in social amoebae is mediated by allelic pairs of tiger genes   总被引：1，自引：0，他引：1  

Hirose S  Benabentos R  Ho HI  Kuspa A  Shaulsky G 《Science (New York, N.Y.)》2011,333(6041):467-470

Free-living cells of the social amoebae Dictyostelium discoideum can aggregate and develop into multicellular fruiting bodies in which many die altruistically as they become stalk cells that support the surviving spores. Dictyostelium cells exhibit kin discrimination--a potential defense against cheaters, which sporulate without contributing to the stalk. Kin discrimination depends on strain relatedness, and the polymorphic genes tgrB1 and tgrC1 are potential components of that mechanism. Here, we demonstrate a direct role for these genes in kin discrimination. We show that a matching pair of tgrB1 and tgrC1 alleles is necessary and sufficient for attractive self-recognition, which is mediated by differential cell-cell adhesion. We propose that TgrB1 and TgrC1 proteins mediate this adhesion through direct binding. This system is a genetically tractable ancient model of eukaryotic self-recognition.  相似文献   

The mutational landscape of head and neck squamous cell carcinoma     

Stransky N  Egloff AM  Tward AD  Kostic AD  Cibulskis K  Sivachenko A  Kryukov GV  Lawrence MS  Sougnez C  McKenna A  Shefler E  Ramos AH  Stojanov P  Carter SL  Voet D  Cortés ML  Auclair D  Berger MF  Saksena G  Guiducci C  Onofrio RC  Parkin M  Romkes M  Weissfeld JL  Seethala RR  Wang L  Rangel-Escareño C  Fernandez-Lopez JC  Hidalgo-Miranda A  Melendez-Zajgla J  Winckler W  Ardlie K  Gabriel SB  Meyerson M  Lander ES  Getz G  Golub TR  Garraway LA  Grandis JR 《Science (New York, N.Y.)》2011,333(6046):1157-1160

Head and neck squamous cell carcinoma (HNSCC) is a common, morbid, and frequently lethal malignancy. To uncover its mutational spectrum, we analyzed whole-exome sequencing data from 74 tumor-normal pairs. The majority exhibited a mutational profile consistent with tobacco exposure; human papillomavirus was detectable by sequencing DNA from infected tumors. In addition to identifying previously known HNSCC genes (TP53, CDKN2A, PTEN, PIK3CA, and HRAS), our analysis revealed many genes not previously implicated in this malignancy. At least 30% of cases harbored mutations in genes that regulate squamous differentiation (for example, NOTCH1, IRF6, and TP63), implicating its dysregulation as a major driver of HNSCC carcinogenesis. More generally, the results indicate the ability of large-scale sequencing to reveal fundamental tumorigenic mechanisms.  相似文献   

Characterization of polyphenolics in the seed coat of Black Jamapa bean (Phaseolus vulgaris L.)     

Aparicio-Fernandez X  Yousef GG  Loarca-Pina G  de Mejia E  Lila MA 《Journal of agricultural and food chemistry》2005,53(11):4615-4622

The common bean contains phytochemicals, including phenolic compounds, which can provide health benefits to the consumer. Our objective was to characterize the polyphenolic compounds present in the seed coat of Black Jamapa bean and to test fractionation methods that permit the recovery of polyphenolics in their naturally occurring forms. A 100% methanol extract from seed coats was subjected to different chromatographic fractionation methods. Analysis by HPLC-MS revealed that a better separation of phytochemicals was achieved using direct silica gel fractionation, which allowed more accurate identification of compounds, especially of the flavonols. Anthocyanins, flavanol monomers, and heterogeneous flavanol oligomers up to hexamers were detected. To our knowledge, this is the first time that myricetin glycoside and proanthocyanidin oligomers containing (epi)-gallocatechin have been reported in the black bean. The fractionation methods used in this study produced large quantities of natural mixtures of flavonoids suitable for testing bioactivity and phytochemical interactions.  相似文献   

Comparing the soil macro-fauna in two oak-wood forests: does community structure differ under similar ambient conditions?     

Rakefet Sharon  Gad Degani  Michael Warburg 《Pedobiologia》2001,45(4)

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Evaluating innovative technologies for multistage fish growth processes: Case study of an eel (Anguilla anguilla L.) farm     

Gregory Yom Din  Zinaida Zugman  Gad Degani 《Aquacultural Engineering》2007,37(3):274-284

A new method for evaluating innovative technologies for multistage fish growth processes was developed. An earlier economic model was adapted to meet the real-world requirements of a commercial eel (Anguilla anguilla L.) farm. The economic benefits of different innovative technologies at the farm level were evaluated where the technology included multiple production alternatives at various intensities and several growth stages. Data were gathered into “bio-economic” tables that take into account the biological parameters of each production alternative and the costs related to its development and implementation. The adjusted data were then divided into groups of production alternatives and feasible combinations of alternatives for each of three growth stages were evaluated to determine the best technology for the overall growth process. A computer program enabled us to enumerate all potential innovative technologies, collect information on biological parameters and costs by growth stage, and compare additional profit expected after implementation of each innovation. Results reveal the most profitable innovative technologies by growth stage for the 5-year eel culture. Comparison of the 10 best technologies shows that combining the alternatives with the best biological parameters for each growth stage does not necessarily result in the maximum additional profit for the farm.  相似文献   

Count-to-weight transform of pre-packed packages,a case study: An efficient implementation of the NIST Handbook 133 requirements     

Gad Vitner  Avital Bechar 《Biosystems Engineering》2011,108(3):204-210

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First molecular characterization of canine hepatozoonosis in Argentina: evaluation of asymptomatic Hepatozoon canis infection in dogs from Buenos Aires     

Eiras DF  Basabe J  Scodellaro CF  Banach DB  Matos ML  Krimer A  Baneth G 《Veterinary parasitology》2007,149(3-4):275-279

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Biosynthesis and characterization of 14C-enriched flavonoid fractions from plant cell suspension cultures     

Yousef GG  Seigler DS  Grusak MA  Rogers RB  Knight CT  Kraft TF  Erdman JW  Lila MA 《Journal of agricultural and food chemistry》2004,52(5):1138-1145

A range of radiolabeled anthocyanins, proanthocyanidins, and other flavonoids were accumulated by cell suspension cultures of two plant species, ohelo (Vaccinium pahalae) and grape (a Vitis hybrid, Bailey Alicant A), after providing uniformly labeled [(14)C]sucrose to the medium. Approximately 15% of administered label was recovered in a series of flavonoid-rich fractions varying in composition. Anthocyanins, and monomers to oligomers of proanthocyanidins, were labeled effectively and characterized from both species. Most of the proanthocyanidin oligomers were based on the flavan-3-ols (+)-catechin and (-)-epicatechin. Cyanidin and peonidin glycosides were the dominant forms of anthocyanins in both species. Whereas the predominant form of flavonoids identified from ohelo cell cultures was proanthocyanidins, grape cell cultures produced mostly anthocyanins. The labeled phytochemicals were produced for use in subsequent in vivo animal feeding studies to gauge their bioavailability and accumulation in target organs.  相似文献   

Antibodies reactive with Ehrlichia canis, Ehrlichia phagocytophila genogroup antigens and the spotted fever group rickettsial antigens, in free-ranging jackals (Canis aureus syriacus) from Israel.     

T Waner  G Baneth  C Strenger  A Keysary  R King  S Harrus 《Veterinary parasitology》1999,82(2):121-128

A seroepidemiological survey was conducted to investigate the prevalence of antibodies reactive with the Ehrlichia canis and Ehrlichia phagocytophila genogroup antigens, and the spotted fever group (SFG) rickettsiae antigens in jackals in Israel (Canis aureus syriacus), to assess the possible role of the jackal in the epidemiology of these diseases. Fifty-three serum samples from jackals were assayed by the indirect immunofluorescence antibody test. Antibodies to E. canis were detected in 35.8% serum samples while 26.4% of the samples tested were positive to Ehrlichia chaffeensis. Twenty-six percent of the jackals tested were seropositive to E. phagocytophila, of which 5.7% were seropositive to E. phagocytophila alone without any seroreactivity to either E. canis or E. chaffeensis. Fifty-five percent of the jackals were seropositive to the SFG-rickettsiae antigens. The results suggest a high exposure rate of jackals in Israel to E. canis. Positive reactivity to E. chaffeensis was considered to be due to antigenic cross-reactions with E. canis. The study demonstrated for the first time the presence of E. phagocytophila antibodies in free-range jackals. The high incidence of antibodies to the SFG-rickettsiae and their relatively high antibody titers was suggestive of either recent or persistent infection. The possibility that jackals may play a role in the transmission of E. canis, E. phagocytophila and the SFG-rickettsiae for human and canine infections is discussed.  相似文献