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31.
Cescutti P Pupulin R Delben F Abbate M Dentini M Sparapano L Rizzo R Crescenzi V 《Carbohydrate research》2002,337(13):1203-1209
The polysaccharides produced by Aureobasidium pullulans, grown using glucosamine as the carbon source, were investigated by means of methylation analysis, affinity chromatography and NMR spectroscopy. The results indicated that, besides a small amount of pullulan, this micro-organism was capable of producing-in low yields-mixtures of at least two different complex polysaccharides containing mainly mannose and galactose. (1)H NMR spectra of two fractions obtained by lectin affinity chromatography indicated that one polymer was constituted exclusively of mannose residues while the other contained both galactofuranosyl and mannopyranosyl residues. 相似文献
32.
Rizzo M De Sarro G Zappalà M Grasso S 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2002,775(1):71-78
The present investigation was designed to develop an assay suitable for pharmacokinetic studies of new compounds, i.e. the novel 7,8-methylenedioxy-4H-2,3-benzodiazepin-4-one derivatives (2a and 2b), acting as non-competitive AMPA-receptor antagonists. A reversed-phase high-performance liquid chromatographic method has been developed to determine the time-course of plasma concentrations of derivatives 2a and 2b administered intraperitoneally to Sprague-Dawley rats. The separation of compounds studied and a N-methyl-2,3-benzodiazepin-4-one derivative as internal standard (I.S.) from plasma, were carried out by liquid-liquid extraction using diethyl ether. The samples were injected onto the analytical column (Partisil 10 ODS) eluted with acetonitrile/0.01 M acetate buffer (pH 5.3) at a flow-rate of 2 ml/min and detected at 240 nm. Compounds 2a, 2b and I.S. gave retention times of 8.5, 5.25 and 11.1 min, respectively. The selectivity of the method was satisfactory. The mean recovery from spiked rat plasma ranged from 86.7 to 91.6% for 2a, and from 85.1 to 87.0% for 2b. The procedures were validated with a good reproducibility and linear response from 0.0625 to 2 microg/ml, with a regression coefficient of 0.9932 for 2a and 0.9854 for 2b. The lower limit of quantification (LOQ) was taken as 15 ng/ml for the two compounds. 2a and 2b showed no signs of significant degradation in rat plasma during storage at -20 degrees C and following freeze/thaw cycles. Moreover, plasma levels of the tested compounds have been correlated with their anticonvulsant activity, determined in vivo in genetically epilepsy-prone rats. Due to its sensitivity, the method was suitable for application to pharmacokinetic study. 相似文献
33.
Activation of Notch-1 signaling maintains the neoplastic phenotype in human Ras-transformed cells 总被引:27,自引:0,他引:27
Weijzen S Rizzo P Braid M Vaishnav R Jonkheer SM Zlobin A Osborne BA Gottipati S Aster JC Hahn WC Rudolf M Siziopikou K Kast WM Miele L 《Nature medicine》2002,8(9):979-986
Truncated Notch receptors have transforming activity in vitro and in vivo. However, the role of wild-type Notch signaling in neoplastic transformation remains unclear. Ras signaling is deregulated in a large fraction of human malignancies and is a major target for the development of novel cancer treatments. We show that oncogenic Ras activates Notch signaling and that wild-type Notch-1 is necessary to maintain the neoplastic phenotype in Ras-transformed human cells in vitro and in vivo. Oncogenic Ras increases levels and activity of the intracellular form of wild-type Notch-1, and upregulates Notch ligand Delta-1 and also presenilin-1, a protein involved in Notch processing, through a p38-mediated pathway. These observations place Notch signaling among key downstream effectors of oncogenic Ras and suggest that it might be a novel therapeutic target. 相似文献
34.
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
35.
Hai-Sheng?Li Kuntala?Shome Raúl?Rojas Mark?A?Rizzo Chandrasekaran?Vasudevan Eric?Fluharty Lorraine?C?Santy James?E?Casanova Guillermo?RomeroEmail author 《BMC cell biology》2003,4(1):13
Background
Phospholipase D (PLD) is involved in many signaling pathways. In most systems, the activity of PLD is primarily regulated by the members of the ADP-Ribosylation Factor (ARF) family of GTPases, but the mechanism of activation of PLD and ARF by extracellular signals has not been fully established. Here we tested the hypothesis that ARF-guanine nucleotide exchange factors (ARF-GEFs) of the cytohesin/ARNO family mediate the activation of ARF and PLD by insulin. 相似文献36.
Collagen fibrils are differently organized in weight-bearing and not-weight-bearing regions of pig articular cartilage 总被引:2,自引:0,他引:2
Gomez S Toffanin R Bernstorff S Romanello M Amenitsch H Rappolt M Rizzo R Vittur F 《The Journal of experimental zoology》2000,287(5):346-352
The magnetic resonance (MR) appearance of the weight-bearing ("loaded") and not-weight-bearing ("unloaded") regions in T(2)-weighted images of pig articular cartilage is different. On the hypothesis that this difference may be ascribed, at least in part, to a different collagen fibre organization in the two regions, this organization was studied using biochemical, histological, and X-ray diffraction methods. While the mean concentrations of collagen and of its cross-links were the same in the two regions, a regular small angle X-ray diffraction pattern was observed only for the habitually "loaded" tissue. It was also seen by light microscopy that the four typical functional zones were well displayed in the "loaded" cartilage whereas they were not clearly depicted in the "unloaded" tissue. Collagen presented a high concentration of fibrils forming an intricate and dense meshwork at the surface of both "loaded" and "unloaded" cartilage. A second zone of high collagen concentration was present at the upper layer of the deep zone of "loaded" cartilage. By contrast, this lamina of highly concentrated fibrils was lacking in "unloaded" cartilage and collagen fibrils appear thinner. Our study proves that the organization of collagen fibres is different for the "loaded" and "unloaded" regions of articular cartilage. It also suggests that this different organization may influence the MR appearance of the tissue. J. Exp. Zool. 287:346-352, 2000. 相似文献
37.
J Daugherty TM Evans T Skillom LE Watson NP Money 《Fungal genetics and biology : FG & B》1998,24(3):354-363
Classical studies on spore release within the Saprolegniaceae (Oomycetes) led to the proposition that different mechanisms of sporangial emptying represent steps in an evolutionary transition series. We have reevaluated this idea in a phylogenetic framework using internal transcribed spacer sequences of four genera. These data were compared with the response to osmotic stress exhibited by each taxon. Saprolegnia emerges as the most basal genus, sister to Achlya, Thraustotheca, and Dictyuchus. Achlya and Thraustotheca are most closely related, while Dictyuchus appears to have evolved along a separate evolutionary lineage. The resulting phylogenetic framework is consistent with the idea that the mechanism of sporangial emptying exhibited by Saprolegnia represents the plesiomorphic condition from which the other mechanisms were derived independently. These alternative mechanisms of spore release may have resulted from a small number of mutations that inhibited axonemal development and altered the temporal and spatial expression of lytic enzymes that degrade the sporangial wall. Copyright 1998 Academic Press. 相似文献
38.
Hai-Yun Xiao Aaron Balog Ricardo M. Attar David Fairfax Linda B. Fleming Christian L. Holst Gregory S. Martin Lana M. Rossiter Jing Chen Mary-Ellen Cvjic Janet Dell-John Jieping Geng Marco M. Gottardis Wen-Ching Han Andrew Nation Mary Obermeier Cheryl A. Rizzo Liang Schweizer Thomas Spires Weifang Shan Gregory Vite 《Bioorganic & medicinal chemistry letters》2010,20(15):4491-4495
A novel series of 4-[3,5-dioxo-11-oxa-4,9-diazatricyclo[5.3.1.02,6]undec-4-yl]-2-trifluoromethyl-benzonitriles has been synthesized. The ability of these compounds to act as antagonists of the androgen receptor was investigated and several were found to have potent activity in vitro and in vivo. 相似文献
39.
Samuel K. Asinof Stacey J. Sukoff Rizzo Alexandra R. Buckley Barbara J. Beyer Verity A. Letts Wayne N. Frankel Rebecca M. Boumil 《PLoS genetics》2015,11(6)
The childhood epileptic encephalopathies (EE’s) are seizure disorders that broadly impact development including cognitive, sensory and motor progress with severe consequences and comorbidities. Recently, mutations in DNM1 (dynamin 1) have been implicated in two EE syndromes, Lennox-Gastaut Syndrome and Infantile Spasms. Dnm1 encodes dynamin 1, a large multimeric GTPase necessary for activity-dependent membrane recycling in neurons, including synaptic vesicle endocytosis. Dnm1Ftfl or “fitful” mice carry a spontaneous mutation in the mouse ortholog of DNM1 and recapitulate many of the disease features associated with human DNM1 patients, providing a relevant disease model of human EE’s. In order to examine the cellular etiology of seizures and behavioral and neurological comorbidities, we engineered a conditional Dnm1Ftfl mouse model of DNM1 EE. Observations of Dnm1
Ftfl/flox mice in combination with various neuronal subpopulation specific cre strains demonstrate unique seizure phenotypes and clear separation of major neurobehavioral comorbidities from severe seizures associated with the germline model. This demonstration of pleiotropy suggests that treating seizures per se may not prevent severe comorbidity observed in EE associated with dynamin-1 mutations, and is likely to have implications for other genetic forms of EE. 相似文献
40.
Francesco Pantano Matteo Santoni Giuseppe Procopio Mimma Rizzo Roberto Iacovelli Camillo Porta Alessandro Conti Antonio Lugini Michele Milella Luca Galli Cinzia Ortega Francesco Maria Guida Marianna Silletta Giovanni Schinzari Elena Verzoni Daniela Modica Pierfilippo Crucitti Annamaria Rauco Alessandra Felici Valentina Ballatore Stefano Cascinu Giuseppe Tonini Giacomo Carteni Antonio Russo Daniele Santini 《PloS one》2015,10(4)