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71.
Muschner VC Lorenz AP Cervi AC Bonatto SL Souza-Chies TT Salzano FM Freitas LB 《American journal of botany》2003,90(8):1229-1238
Passiflora, a genus with more than 400 species, exhibits a high diversity of floral and vegetative structures and a complex taxonomy, which includes 23 subgenera and many sections and series. To better understand Passiflora's variability and interspecific relationships, the phylogeny of 61 species, classified in 11 of 23 suggested subgenera, was investigated. Three molecular markers were used, the nuclear ribosomal internal transcribed spacers (nrITS), the plastid trnL-trnF spacer regions (~1000 bp), and the rps4 plastid gene (~570 bp). Three major clades were highly supported, independent of the marker and phylogenetic method used; one included the subgenera Distephana, Dysosmia, Dysosmioides, Passiflora, and Tacsonioides, a second, the subgenera Adopogyne, Decaloba, Murucuja, and Pseudomurucuja, and a third, the subgenus Astrophea. We call these the Passiflora, Decaloba, and Astrophea clades, respectively. The position of subgenus Deidamioides is undefined. The monophyly of Passiflora could not be statistically corroborated, and the relationships among the major clades and of these clades with the related genera remain unresolved. Our results indicate that a reevaluation of the monophyly of Passiflora and its infrageneric classification is necessary. 相似文献
72.
Palmitate acutely raises glycogen synthesis in rat soleus muscle by a mechanism that requires its metabolization (Randle cycle) 总被引:3,自引:0,他引:3
Massao Hirabara S de Oliveira Carvalho CR Mendonça JR Piltcher Haber E Fernandes LC Curi R 《FEBS letters》2003,541(1-3):109-114
The acute effect of palmitate on glucose metabolism in rat skeletal muscle was examined. Soleus muscles from Wistar male rats were incubated in Krebs-Ringer bicarbonate buffer, for 1 h, in the absence or presence of 10 mU/ml insulin and 0, 50 or 100 microM palmitate. Palmitate increased the insulin-stimulated [(14)C]glycogen synthesis, decreased lactate production, and did not alter D-[U-(14)C]glucose decarboxylation and 2-deoxy-D-[2,6-(3)H]glucose uptake. This fatty acid decreased the conversion of pyruvate to lactate and [1-(14)C]pyruvate decarboxylation and increased (14)CO(2) produced from [2-(14)C]pyruvate. Palmitate reduced insulin-stimulated phosphorylation of insulin receptor substrate-1/2, Akt, and p44/42 mitogen-activated protein kinases. Bromopalmitate, a non-metabolizable analogue of palmitate, reduced [(14)C]glycogen synthesis. A strong correlation was found between [U-(14)C]palmitate decarboxylation and [(14)C]glycogen synthesis (r=0.99). Also, palmitate increased intracellular content of glucose 6-phosphate in the presence of insulin. These results led us to postulate that palmitate acutely potentiates insulin-stimulated glycogen synthesis by a mechanism that requires its metabolization (Randle cycle). The inhibitory effect of palmitate on insulin-stimulated protein phosphorylation might play an important role for the development of insulin resistance in conditions of chronic exposure to high levels of fatty acids. 相似文献
73.
Jean-Paul Wathelet Renato Iori Onofrio Leoni Patrick Rollin Nicolas Mabon Michel Marlier Sandro Palmieri 《Biotechnology letters》2001,23(6):443-446
Glucosinolates, natural compounds found in Brassicaceae, can easily be transformed into desulfo-glucosinolates by action of Helix pomatia sulfatase. The recombinant -O-glucosidase from Caldocellum saccharolyticum does not catalyse glucosinolate degradation but can hydrolyse desulfo-glucosinolates (thio-d-glucosidic substrates) to produce the corresponding pure nitriles, including valuable homochiral representatives. 相似文献
74.
Lefeber DJ Gutiérrez Gallego R Grün CH Proietti D D'Ascenzi S Costantino P Kamerling JP Vliegenthart JF 《Carbohydrate research》2002,337(9):819-825
A series of well-defined oligosaccharide fragments of the capsular polysaccharide of Streptococcus pneumoniae type 3 has been generated. Partial-acid hydrolysis of the capsular polysaccharide, followed by fractionation of the oligosaccharide mixture by Sepharose Q ion-exchange chromatography yielded fragments containing one to seven [-->3)-beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->] repeating units. The isolated fragments were analysed for purity by high-pH anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) using an IonPac AS11 column, and their structures were verified by 1H NMR spectroscopy and nano-electrospray mass spectrometry. The oligosaccharides can be used to produce neoglycoprotein vaccines with a defined carbohydrate part. 相似文献
75.
Marques S Barros-Battesti DM Faccini JL Onofrio VC 《Memórias do Instituto Oswaldo Cruz》2002,97(8):1141-1146
Amblyomma varium, commonly known in Brazil as the "carrapato-gigante-da-pregui a" (sloth's giant tick) is found from southern Central America to Argentina. The present study adds information on the geographical distribution of A. varium, as well as on their hosts, based on material deposited in the main Brazilian collections and on the available literature. Eighty-two vials, containing 191 adult specimens, deposited in five Acari collections between 1930 and 2001, were examined. These vials included data on the host and collection localities. The biology of A. varium is unknown. However it is known that, during the adult stage, the tick presents a high host specificity and is found almost exclusively on the sloths Bradypus tridactylus, B. variegatus, B.torquatus (Bradypodidae), Choloepus hoffmanni and C. didactylus (Megalonychidae). Based on the material examined, the states of Rond nia, Amazonas, Bahia and Alagoas are newly assigned to geographic distribution of A. varium in Brazil. 相似文献
76.
Rizzo AM Rossi F Guerra A Pippia P Meloni MA Berra B 《Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology》2002,9(1):P207-P208
The aim of this work is to evaluate the development of X.l. in modified gravity conditions. The simulation of hyper and microgravity was performed utilizing: an hyperfuge, a Clinostat and later on a Random Positioning Machine (RPM, 3d Clinostat). The effect of hypergravity on embryos is significantly higher than that of microgravity; the exposure of embryos to 3xg for 3 days before and after hatch causes an activation of HSP-60 and HSP-70. Embryos exposed to 3xg during the first 3 days of development are very sensitive and show a retard of development, with a lower content of DNA, neutral glycolipids and gangliosides compared to controls. 相似文献
77.
Meloni MA Galleri G Carta S Negri R Costanzo G De Sanctis V Cogoli A Pippia P 《Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology》2002,9(1):P291-P292
Several experiments demontrated the influence of microgravity on mitogenic activation of T cells at molecular level. To discriminate between cffects of microgravity and cosmic radiations, in this work we studied the effects of high cosmic radiations on the genetic expression in human T cells boarded in a stratospheric balloon (BIRBA-1 mission, 22 hours of flight). The genetic expression was analized by the cDNA microarray hybridization technology, which allows the comparative and simultaneous estimate of hundreds of mRNAs Activated cells react to the ionizing stress by activating genes involved in cell cycle check-point, oxidative stress response, heat shock proteins production or by repressing genes involved in antigen recognition. 相似文献
78.
Polycarpo C Ambrogelly A Ruan B Tumbula-Hansen D Ataide SF Ishitani R Yokoyama S Nureki O Ibba M Söll D 《Molecular cell》2003,12(2):287-294
Monomethylamine methyltransferase of the archaeon Methanosarcina barkeri contains a rare amino acid, pyrrolysine, encoded by the termination codon UAG. Translation of this UAG requires the aminoacylation of the corresponding amber suppressor tRNAPyl. Previous studies reported that tRNAPyl could be aminoacylated by the synthetase-like protein PylS. We now show that tRNAPyl is efficiently aminoacylated in the presence of both the class I LysRS and class II LysRS of M. barkeri, but not by either enzyme acting alone or by PylS. In vitro studies show that both the class I and II LysRS enzymes must bind tRNAPyl in order for the aminoacylation reaction to proceed. Structural modeling and selective inhibition experiments indicate that the class I and II LysRSs form a ternary complex with tRNAPyl, with the aminoacylation activity residing in the class II enzyme. 相似文献
79.
80.
We report on the reproductive biology of southwestern Atlantic wreckfish. Females mature first at 77.9cm total length (TL) (10.4 years) and all are mature by 90cm TL (15.2 years). Males mature first at 74.9cm (9 years) and all are mature by 80cm TL (10.9 years). The wreckfish is a gonochoristic multiple spawner and the gonadal cycle is synchronized at the population level. Spawning occurs from late July to early October along the continental slope (<300m). Ovarian fecundity varies from 3 to 11.9 million (135–311 oocytes×g–1) and increases exponentially with length. Spawning at western boundary current systems, maintained by homing of adults, is a basic requirement for self-sustaining populations of this species. 相似文献