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51.
G J Schouten H G van Luenen N C Verra D Valerio R H Plasterk 《Nucleic acids research》1998,26(12):3013-3017
The transposon Tc1 of the nematode Caenorhabditis elegans is a member of the widespread family of Tc1/mariner transposons. The distribution pattern of virtually identical transposons among insect species that diverged 200 million years ago suggested horizontal transfer of the elements between species. Thishypothesis gained experimental support when it was shown that Tc1 and later also mariner transposons could be made to jump in vitro , with their transposase as the only protein required. Later it was shown that mariner transposons from one fruit fly species can jump in other fruit fly species and in a protozoan and, recently, that a Tc1-like transposon from the nematode jumps in fish cells and that a fish Tc1-like transposon jumps in human cells. Here we show that the Tc1 element from the nematode jumps in human cells. This provides further support for the horizontal spread hypothesis. Furthermore, it suggests that Tc1 can be used as vehicle for DNA integration in human gene therapy. 相似文献
52.
Rumio C Besusso D Arnaboldi F Palazzo M Selleri S Gariboldi S Akira S Uematsu S Bignami P Ceriani V Ménard S Balsari A 《Journal of cellular physiology》2006,208(1):47-54
The cell types of the gut expressing Toll-like receptor 4, which recognizes specifically bacterial lipopolysaccharides, as well as the functionality of this receptor, have remained controversial. We aimed to clarify these issues. Mouse and human intestinal specimens were stained immunohistochemically to detect Toll-like receptor 4 expression. Smooth muscle and myenteric plexus cells but not enterocytes revealed receptor expression. Murine intestinal smooth muscle and myenteric plexus cells but not enterocytes showed nuclear translocation of nuclear factor-kappaB after in vivo stimulation with lipopolysaccharide. Moreover, lipopolysaccharide added to human jejunum biopsies free of epithelial cells induced release of interleukin-8 (IL-8). We can conclude that Toll-like receptor 4 is not expressed in epithelial layer, but rather on smooth muscle and myenteric plexus cells and that expression is functional. The expression of Toll-like receptor 4 on smooth muscle and myenteric plexus cells is consistent with the possibility that these cells are involved in intestinal immune defense; the low or absent expression of Toll-like receptor 4 on enterocytes might explain the intestinal epithelium hyporesponsiveness to the abundance of LPS in the intestinal lumen. 相似文献
53.
Dott. Valerio Giacomini 《Plant biosystems》2013,147(3):624-648
Riassunto L'A. esamina i componenti fondamentali della flora briologica dell'Africa settentrionale mediterranea, in relazione con i tipi climatici. Distingue un Elemento mediterranco (coi gruppi: stenomediterraneo, euri-mediterraneo, mediterraneo-montano, mediterraneo-atlantico, mediterraneo-steppico, saharo-sindico), atlantico, circumboreale, orofilo-boreale, ipsofilo-boreale, aralo-caspico, cosmopolita ed endemico. 相似文献
54.
55.
Ingemar Björkhem Angel Cedazo-Minguez Valerio Leoni Steve Meaney 《Molecular aspects of medicine》2009,30(3):171-179
In contrast to their parent molecule cholesterol, two of its side-chain oxidized metabolites are able to cross the blood–brain barrier. There is a concentration-driven flux of 24S-hydroxycholesterol (24S-OHC) from the brain into the circulation, which is of major importance for elimination of excess cholesterol from the brain. The opposite flux of 27-hydroxycholesterol (27-OHC) from the circulation into the brain may regulate a number of key enzymes within the brain. In vitro experiments suggest that the balance between the levels of these two molecules may be of importance for the generation of β-amyloid peptides. In primary cultures of rat hippocampal cells 27-OHC is able to suppress expression of the activity regulated cytoskeleton-associated protein (Arc), a protein important in memory consolidation which is reduced in patients with Alzheimer’s disease (AD). In the present work we explore the possibility that the flux of 27-OHC from the circulation into the brain represents the missing link between AD and hypercholesterolemia, and discuss the possibility that modification of this flux may be a therapeutic strategy. Lastly, we discuss the use of oxysterols as diagnostic markers in neurodegenerative disease. 相似文献
56.
Romano Silvestri Alessia Ligresti Giuseppe La Regina Francesco Piscitelli Valerio Gatti Antonella Brizzi Serena Pasquini Antonio Lavecchia Marco Allarà Noemi Fantini Mauro Antonio Maria Carai Ettore Novellino Giancarlo Colombo Vincenzo Di Marzo Federico Corelli 《Bioorganic & medicinal chemistry》2009,17(15):5549-5564
New substituted 1-aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamides were synthesized by replacing the 2,4-dichlorobenzyl and cyclohexyl moieties at the 3-carboxamide nitrogen of the previously reported CB1 receptor antagonists/inverse agonists 4 and 5. Several ligands showed potent affinity for the hCB1 receptor, with Ki concentrations comparable to the reference compounds 1, 4 and 5, and exhibited CB1 selectivity comparable to 1 and 2. Docking experiments and molecular dynamics (MD) simulations explained the potent hCB1 binding affinity of compounds 31 and 37. According to our previous studies, 31 and 37 formed a H-bond with K3.28(192), which accounted for the high affinity for the receptor inactive state and the inverse agonist activity. The finding of inhibition of food intake following their acute administration to rats, supported the concept that the CB1 selective compounds 4 and 52 act as antagonists/inverse agonists. 相似文献
57.
Background
Synesthesia is a condition in which the stimulation of one sense elicits an additional experience, often in a different (i.e., unstimulated) sense. Although only a small proportion of the population is synesthetic, there is growing evidence to suggest that neurocognitively-normal individuals also experience some form of synesthetic association between the stimuli presented to different sensory modalities (i.e., between auditory pitch and visual size, where lower frequency tones are associated with large objects and higher frequency tones with small objects). While previous research has highlighted crossmodal interactions between synesthetically corresponding dimensions, the possible role of synesthetic associations in multisensory integration has not been considered previously.Methodology
Here we investigate the effects of synesthetic associations by presenting pairs of asynchronous or spatially discrepant visual and auditory stimuli that were either synesthetically matched or mismatched. In a series of three psychophysical experiments, participants reported the relative temporal order of presentation or the relative spatial locations of the two stimuli.Principal Findings
The reliability of non-synesthetic participants'' estimates of both audiovisual temporal asynchrony and spatial discrepancy were lower for pairs of synesthetically matched as compared to synesthetically mismatched audiovisual stimuli.Conclusions
Recent studies of multisensory integration have shown that the reduced reliability of perceptual estimates regarding intersensory conflicts constitutes the marker of a stronger coupling between the unisensory signals. Our results therefore indicate a stronger coupling of synesthetically matched vs. mismatched stimuli and provide the first psychophysical evidence that synesthetic congruency can promote multisensory integration. Synesthetic crossmodal correspondences therefore appear to play a crucial (if unacknowledged) role in the multisensory integration of auditory and visual information. 相似文献58.
Liliana Milani Fabrizio Ghiselli Marco Pellecchia Valerio Scali Marco Passamonti 《BMC evolutionary biology》2010,10(1):258
Background
Phasmids show noteworthy abilities to overcome species-specific reproductive isolation mechanisms, including hybridization, polyploidy, parthenogenesis, hybridogenesis and androgenesis. From an evolutionary standpoint, such tangled reproductive interactions lead to the complex phyletic relationships known as "reticulate evolution". Moroccan stick insects of the genus Clonopsis include one bisexual (C. felicitatis) and two closely related parthenogenetic forms (C. gallica, C. soumiae), which represent a polyploid series in chromosome number, but with apparent diploid karyotypes. Moreover, two Clonopsis strains of ameiotic males have been described, C. androgenes-35 and C. androgenes-53. As a consequence, Clonopsis stick insects may have experienced complex micro-evolutionary events, which we try to disentangle in this study. 相似文献59.
Hanessian S Vinci V Auzzas L Marzi M Giannini G 《Bioorganic & medicinal chemistry letters》2006,16(18):4784-4787
Analogues of suberoylanilide hydroxamic acid (SAHA) were prepared by replacing the Zn-binding group with squaric acid, N-hydroxyurea, and 4-hydroxymethyl oxazoline units, also varying the length of the aliphatic chain. No inhibitory activity on HDAC was observed below 1.0 microM and no cytotoxic activity on different tumor cell lines was seen below 20.0 microM. 相似文献
60.
Alessandra Basso Patrizia Spizzo Valerio Ferrario Lorena Knapic Nina Savko Paolo Braiuca Cynthia Ebert Emanuele Ricca Vincenza Calabrò Lucia Gardossi 《Biotechnology progress》2010,26(2):397-405
Three‐dimensional models of exoinulinase from Bacillus stearothermophilus and endoinulinase from Aspergillus niger were built up by means of homology modeling. The crystal structure of exoinulinase from Aspergillus awamori was used as a template, which is the sole structure of inulinase resolved so far. Docking and molecular dynamics simulations were performed to investigate the differences between the two inulinases in terms of substrate selectivity. The analysis of the structural differences between the two inulinases provided the basis for the explanation of their different regio‐selectivity and for the understanding of enzyme‐substrate interactions. Surface analysis was performed to point out structural features that can affect the efficiency of enzymes also after immobilization. The computational analysis of the three‐dimensional models proved to be an effective tool for acquiring information and allowed to formulate an optimal immobilized biocatalyst even more active that the native one, thus enabling the full exploitation of the catalytic potential of these enzymes. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 相似文献