Sucrose efflux mediated by SWEET proteins as a key step for phloem transport     

Chen LQ  Qu XQ  Hou BH  Sosso D  Osorio S  Fernie AR  Frommer WB 《Science (New York, N.Y.)》2012,335(6065):207-211

Plants transport fixed carbon predominantly as sucrose, which is produced in mesophyll cells and imported into phloem cells for translocation throughout the plant. It is not known how sucrose migrates from sites of synthesis in the mesophyll to the phloem, or which cells mediate efflux into the apoplasm as a prerequisite for phloem loading by the SUT sucrose-H(+) (proton) cotransporters. Using optical sucrose sensors, we identified a subfamily of SWEET sucrose efflux transporters. AtSWEET11 and 12 localize to the plasma membrane of the phloem. Mutant plants carrying insertions in AtSWEET11 and 12 are defective in phloem loading, thus revealing a two-step mechanism of SWEET-mediated export from parenchyma cells feeding H(+)-coupled import into the sieve element-companion cell complex. We discuss how restriction of intercellular transport to the interface of adjacent phloem cells may be an effective mechanism to limit the availability of photosynthetic carbon in the leaf apoplasm in order to prevent pathogen infections.  相似文献   

Pharmacological mechanisms of black cohosh in Sprague-Dawley rats     

Einbond LS  Soffritti M  Esposti DD  Wu HA  Tibaldi E  Lauriola M  He K  Park T  Su T  Huggins L  Wang X  Roller M  Brennan R 《Fitoterapia》2012,83(3):461-468

Background

Studies indicate that extracts and purified components from black cohosh inhibit the growth of human breast cancer cells, but the molecular targets and signaling pathways have not yet been defined.

Purpose

This study examines the pharmacological mechanisms and toxicological effects in the short term of the herb black cohosh on female Sprague–Dawley rats.

Materials and methods

To assess effects on gene activity and lipid content, we treated female Sprague–Dawley rats with an extract of black cohosh enriched in triterpene glycosides (27%) at 35.7 or 0 mg/kg. Four animals for each group were sacrificed at 1, 6 and 24 h after treatment; liver tissue and serum samples were obtained for gene expression and lipid analysis.

Results

Microarray analysis of rat liver tissue indicated that black cohosh markedly downregulated mitochondrial oxidative phosphorylation genes. Phospholipid biosynthesis and remodeling, PI3-Kinase and sphingosine signaling were upregulated, driven largely by an upregulation of several isoforms of phospholipase C. Hierarchical clustering indicated that black cohosh clustered with antiproliferative compounds, specifically tubulin binding vinca alkaloids and DNA alkylators. In support of this, black cohosh repressed the expression of cyclin D1 and ID3, and inhibited the proliferation of HepG2, p53 positive, liver cancer cells. Black cohosh reduced the level of free fatty acids at 6 and 24 h and triglycerides at 6 h in the serum, but increased the free fatty acid and triglyceride content of the treated livers at 24 h.

Conclusion

Our results suggest that black cohosh warrants further study for breast cancer prevention and therapy.  相似文献   

Novel swine influenza virus subtype H3N1 in Italy   总被引：2，自引：0，他引：2  

Ana Moreno  Ilaria Barbieri  Enrica Sozzi  Andrea Luppi  Davide Lelli  Guerino Lombardi  Maria Grazia Zanoni  Paolo Cordioli 《Veterinary microbiology》2009,138(3-4):361-367

To date, three subtypes of swine influenza viruses, H1N1, H1N2, and H3N2 have been isolated in Italy. In 2006, a novel swine influenza virus subtype (H3N1) was isolated from coughing pigs. RT-PCR performed on lung tissues, experimental infection in pigs with the novel isolate, and cloning the virus by plaque assay confirmed this unique H and N combination. The novel isolate was also antigenically and genetically characterized. Genetic and phylogenetic analysis showed that the complete HA gene of the H3N1 strain has the highest nucleotide identity to three Italian H3N2 strains, one isolated in 2001 and two in 2004, whereas the full length NA sequence is closely related to three H1N1 subtype viruses isolated in Italy in 2004. The remaining genes are also closely related to respective genes found in H1N1 and H3N2 SIVs currently circulating in Italy. This suggests that the novel SIV could be a reassortant between the H3N2 and H1N1 SIVs circulating in Italy.  相似文献   

Repeated occurrence of jejuno-jejunal intussusception in a calf          下载免费PDF全文

Davide Pravettoni  Nicola Morandi  Marco Rondena  Pietro Riccaboni  Davide D. Zani  Massimiliano Scandella    Angelo G. Belloli 《The Canadian veterinary journal. La revue veterinaire canadienne》2009,50(3):287-290

This paper reports the clinical findings, diagnostic imaging, surgical management, and necropsy of an unusual case of jejuno-jejunal intussusception in a calf that was diagnosed with the use of ultrasonography, and treated surgically by resection and end-to-end anastomosis. The calf fatally relapsed 8 d after laparotomy. Necropsy and histology revealed enteritis and myenteric ganglionitis.  相似文献   

Degradation of Monoethanolamine in Aqueous Solution by Fenton’s Reagent with Biological Post-treatment     

Sabtanti Harimurti  Binay K. Dutta  Idzham Fauzi B. M. Ariff  Sampa Chakrabarti  Davide Vione 《Water, air, and soil pollution》2010,211(1-4):273-286

Alkanolamines in the wastewater from gas treating plants are not readily biodegradable. In this work, we have investigated the effectiveness of the Fenton’s reagent (H₂O₂-Fe²⁺) to treat monoethanolamine (MEA) as a model compound in simulated wastewater. Degradation studies were carried out in a jacketed glass reactor. The effects of concentrations of ferrous sulfate, hydrogen peroxide, and the pH of a solution on the rate of reaction were determined. A pH of 3 was found to be the optimum. The degradation reaction proceeds very fast at the beginning but slows down significantly at a longer time. A larger fractional degradation of the organics in solution was observed if the initial chemical oxygen demand (COD) of the feed solution was high. Gradual addition of H₂O₂ to the reaction mixture increased the COD removal by about 60% compared to one-time addition of the reagent at the beginning of the process. A rate equation for mineralization of the amine was developed on the basis of a simplified mechanistic model, and the lumped value of the rate constant for COD removal was determined. A partially degraded MEA solution as well as “pure” MEA was subjected to biological oxidation by activated sludge. The former substrate degraded much faster. The degradation rate and biomass generation data could be fitted by the Monod kinetic equations.  相似文献   

History and Trends of Sediment Contamination by Heavy Metals Within and Close to a Marine Area of National Interest: The Ligurian Sea off Cogoleto-Stoppani (Genoa, Italy)     

Cristian Mugnai  Rosa M. Bertolotto  Federico Gaino  Christian Tiberiade  Luca G. Bellucci  Silvia Giuliani  Stefania Romano  Mauro Frignani  Sonia Albertazzi  Davide Galazzo 《Water, air, and soil pollution》2010,211(1-4):69-77

Due to its remarkable sediment pollution caused by past industrial activities, the Mediterranean coastal area facing the town of Cogoleto (near Genoa) has been declared of “national interest”. Seven sediment cores were analysed to provide information on history and trend of heavy metal inputs, with a particular focus on Cr. Grain-size compositions and ²¹⁰Pb chronologies account for a strong influence of terrigenous inputs near the coast and the mouth of the Lerone Creek (draining the industrial settlement), with sand contents and accumulation rates varying from 40.3% and 0.7 cm year^?1 near shore to 2.5% and 0.1 cm year^?1 offshore. Heavy metal concentrations are high, notably Cr and Ni, and to a lesser extent, Ag, Hg, Pb, Cu and Zn. Cr, that shows past values up to 3,642 µg g^?1, presents only minor recent decreases. In the area, it has both natural and anthropogenic sources and their relative contributions were distinguished on the basis of Cr/Ni ratios. These are 1–1.5 in soils and rocks of the Lerone Creek catchment area but reach very high values (up to 10) in marine sediments due to the anthropogenic contribution. The anthropogenic influence is higher near the creek mouth, gradually decreases offshore and is negligible at the most distal site (ca. 2.9 km from the coast).  相似文献   

Characterization of Pro-embryogenic Calli and Somatic Embryogenesis of Byrsonima intermedia A. Juss.     

Luciano Coutinho Silva  Renato Paiva  Diogo Pedrosa Correa Da Silva  Sandro Barbosa  Rairys CravoHerrera  Lisete Chamma Davide  Patricia Duarte De Oliveira Paiva 《农业科学与技术》2012,(8):962-970

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Use of fine needle aspirates and flow cytometry for the diagnosis, classification, and immunophenotyping of canine lymphomas.     

Mahmut S?zmen  Silvia Tasca  Erika Carli  Davide De Lorenzi  Tommaso Furlanello  Marco Caldin 《Journal of veterinary diagnostic investigation》2005,17(4):323-330

Fifty canine lymphomas were classified cytomorphologically using the updated Kiel classification scheme. Aspirates of lymph nodes from dogs with lymphoma were stained using 5 canine-specific antibodies and 3 human-specific antibodies that cross-react with canine lymphocytes. The antibody-stained aspirates were analyzed by flow cytometry. A total of 32 (64%) of the 50 lymphomas were characterized as B-cell origin and 18 (36%) were of T-cell origin. B-cell lymphomas were identified in 12 females and 20 males with a mean age of 8.35 years. T-cell lymphomas were identified in 8 females and 10 males with a mean age of 7.9 years. A minority of the lymphomas were low-grade B-cell and T-cell lymphomas (6/50, 12% and 4/50, 8%, respectively). The most common morphologic types were high-grade centroblastic and unclassifiable plasmacytoid for B- and T-cell lymphomas (18/50, 36% and 7/50, 14%, respectively).  相似文献   

Characterization of fungicide sensitivity profiles of Botrytis cinerea populations sampled in Lombardy (Northern Italy) and implications for resistance management     

Silvia L Toffolatti  Giuseppe Russo  Davide Bezza  Piero A Bianco  Federico Massi  Demetrio Marcian  Giuliana Maddalena 《Pest management science》2020,76(6):2198-2207

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Dyskeratosis congenita and cancer in mice deficient in ribosomal RNA modification     

Ruggero D  Grisendi S  Piazza F  Rego E  Mari F  Rao PH  Cordon-Cardo C  Pandolfi PP 《Science (New York, N.Y.)》2003,299(5604):259-262

Mutations in DKC1 cause dyskeratosis congenita (DC), a disease characterized by premature aging and increased tumor susceptibility. The DKC1 protein binds to the box H + ACA small nucleolar RNAs and the RNA component of telomerase. Here we show that hypomorphic Dkc1 mutant (Dkc1m) mice recapitulate in the first and second generations (G1 and G2) the clinical features of DC. Dkc1m cells from G1 and G2 mice were impaired in ribosomal RNA pseudouridylation before the onset of disease. Reductions of telomere length in Dkc1m mice became evident only in later generations. These results suggest that deregulated ribosome function is important in the initiation of DC, whereas telomere shortening may modify and/or exacerbate DC.  相似文献