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排序方式: 共有420条查询结果,搜索用时 187 毫秒
411.
412.
Luca Antonioli Carolina Pellegrini Matteo Fornai Erika Tirotta Daniela Gentile Laura Benvenuti Maria Cecilia Giron Valentina Caputi Ilaria Marsilio Genny Orso Nunzia Bernardini Cristina Segnani Chiara Ippolito Balázs Csóka Zoltán H. Németh György Haskó Carmelo Scarpignato Corrado Blandizzi Rocchina Colucci 《Purinergic signalling》2017,13(4):497-510
Adenosine A2B receptors (A2BR) regulate several enteric functions. However, their implication in the pathophysiology of intestinal dysmotility associated with high-fat diet (HFD)-induced obesity has not been elucidated. We investigated the expression of A2BR in mouse colon and their role in the mechanisms underlying the development of enteric dysmotility associated with obesity. Wild-type C57BL/6J mice were fed with HFD (60% kcal from fat) or normocaloric diet (NCD; 18% kcal from fat) for 8 weeks. Colonic A2BR localization was examined by immunofluorescence. The role of A2BR in the control of colonic motility was examined in functional experiments on longitudinal muscle preparations (LMPs). In NCD mice, A2BR were predominantly located in myenteric neurons; in HFD animals, their expression increased throughout the neuromuscular layer. Functionally, the A2BR antagonist MRS1754 enhanced electrically induced NK1-mediated tachykininergic contractions in LMPs from HFD mice, while it was less effective in tissues from NCD mice. The A2B receptor agonist BAY 60-6583 decreased colonic tachykininergic contractions in LMPs, with higher efficacy in preparations from obese mice. Both A2BR ligands did not affect contractions elicited by exogenous substance P. Obesity is related with a condition of colonic inflammation, leading to an increase of A2BR expression. A2BR, modulating the activity of excitatory tachykininergic nerves, participate to the enteric dysmotility associated with obesity. 相似文献
413.
Carlucci Roberto Capezzuto Francesca Cipriano Giulia D’Onghia Gianfranco Fanizza Carmelo Libralato Simone Maglietta Rosalia Maiorano Porzia Sion Letizia Tursi Angelo Ricci Pasquale 《Reviews in Fish Biology and Fisheries》2021,31(1):135-156
Reviews in Fish Biology and Fisheries - The exploitation of fishery resources acts as a driving force on cetaceans both directly, by determining their fishing mortality or injury as by-catch... 相似文献
414.
415.
Lorenzo Chiariotti Pietro Alifano M. Stella Carlomagno Carmelo B. Bruni 《Molecular & general genetics : MGG》1986,203(3):382-388
Summary In this paper we report the nucleotide sequence of the hisD gene of Escherichia coli and of the hisIE region of both E. coli and Salmonella typhimurium. The hisD gene codes for a bifunctional enzyme, l-histidinol: NAD+ oxidoreductase, of 434 amino acids with a molecular mass of 46,199 daltons. We established that the hisIE region of both S. typhimurium and E. coli is composed of a single gene and not, as previously believed, of two separate genes. The derived amino acid sequence indicates that the hisIE gene codes for a bifunctional protein of 203 amino acids with an approximate molecular mass of 22,700 daltons. We also determined the nucleotide sequence of a deletion mutant in S. typhimurium which abolishes the hisF and hisI functions but retains the hisE function. We deduced that the mutant produces a chimeric protein fusing the aminoterminal region of the upstream hisF gene to the carboxylterminal domain of the hisIE gene which encodes for the hisE function. In view of these results the structural and functional organization of the histidine operon in enteric bacteria needs to be revised. The operon is composed of only 8 genes and the pathway leading to the biosynthesis of the amino acid requires 11 enzymatic steps. 相似文献
416.
Danilo Milardi Carmelo La Rosa D. Grasso Rita Guzzi Luigi Sportelli Carlo Fini 《European biophysics journal : EBJ》1998,27(3):273-282
The thermal denaturation of plastocyanin in aqueous solution was investigated by means of DSC, ESR and absorbance techniques,
with the aim of determining the thermodynamic stability of the protein and of characterizing the thermally induced conformational
changes of its active site. The DSC and absorbance experiments indicated an irreversible and kinetically controlled denaturation
path. The extrapolation of the heat capacity and optical data at infinite scan rate made it possible to calculate the kinetic
and thermodynamic parameters associated with the denaturation steps. The denaturation pathway proposed, and the parameters
found from the calorimetric data, were checked by computer simulation using an equation containing the information necessary
to describe the denaturation process in detail. ESR and absorbance measurements have shown that structural changes of the
copper environment occur during the protein denaturation. In particular, the geometry of the copper-ligand atoms changes from
being tetrahedral to square planar and the disruption of the active site precedes the global protein denaturation. The thermodynamic
enthalpic change, the half-width transition temperature, and the value of ΔCp, were used to calculate the thermodynamic stability, ΔG, of the reversible process over the entire temperature range of denaturation. The low thermal stability found for plastocyanin,
is discussed in connection with structural factors stabilizing the native state of a protein.
Received: 17 July 1997 / Revised version: 22 November 1997 / Accepted: 15 January 1998 相似文献
417.
Agata Torre Francesca Trischitta Carmelo Corsaro Domenico Mallamace Caterina Faggio 《Cell biochemistry and function》2013,31(6):489-495
The response of isolated digestive cells of the digestive gland of Mytilus galloprovincialis to hypotonic shock was studied using videometric methods. The isolated cells exposed to a rapid change (from 1100 to 800 mosmol kg?1) of the bathing solution osmolality swelled but thereafter underwent a regulatory volume decrease (RVD), tending to recover the original size. When the hypotonic stress was applied in the presence of quinine and glibenclamide, known inhibitors of swelling activated ion channels, the cells did not exhibit an RVD response; in addition, they showed a larger increase in size in respect to control cells. These observations suggest that the digestive cells of the digestive gland have the machinery to cope with the hyposmotic shock allowing them to exhibit a small but significant RVD preventing an excessive increase in cell size. The pharmacological treatment of digestive cells during the RVD experiments suggests that cell volume is regulated by K+ and Cl? efflux followed by an obliged water efflux from the cell. The involvement of organic osmolytes such as taurine and betaine seems to be excluded by NMR measurement on digestive cells. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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419.
Summary The growth of Cyanidium caldarium on nitrate and ammonia as nitrogen sources was studied at different temperatures from 21 to 54°C.Algal growth occurred at temperatures of 24° C or above when ammonia was the nitrogen source, whereas with nitrate, growth occurred at 30° C or above. The optimum and the maximum growth temperatures were 45 and 54° C respectively on both substrates.Arrhenius plots show that the logarithm of the growth rate is not linear with the reciprocal of absolute temperature, but exhibit sharply defined breaks at 30° C on ammonia and at 40° C on nitrate.It is assumed that below 40° C, when Cyanidium grows on nitrate, the utilization of this substrate represents the master reaction which controls the growth rate of the alga. 相似文献
420.
Ashley Castellanos-Jankiewicz Omar Guzmán-Quevedo Valérie S. Fénelon Philippe Zizzari Carmelo Quarta Luigi Bellocchio Anne Tailleux Julie Charton Daniela Fernandois Marcus Henricsson Catherine Piveteau Vincent Simon Camille Allard Sandrine Quemener Valentine Guinot Nathalie Hennuyer Alessia Perino Alexia Duveau Daniela Cota 《Cell metabolism》2021,33(7):1483-1492.e10