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71.
72.
Mohammad Haeri Peter D. Calvert Eduardo Solessio Edward N. Pugh Jr Barry E. Knox 《PloS one》2013,8(11)
The rod outer segment (OS), comprised of tightly stacked disk membranes packed with rhodopsin, is in a dynamic equilibrium governed by a diurnal rhythm with newly synthesized membrane inserted at the OS base balancing membrane loss from the distal tip via disk shedding. Using transgenic Xenopus and live cell confocal imaging, we found OS axial variation of fluorescence intensity in cells expressing a fluorescently tagged rhodopsin transgene. There was a light synchronized fluctuation in intensity, with higher intensity in disks formed at night and lower intensity for those formed during the day. This fluctuation was absent in constant light or dark conditions. There was also a slow modulation of the overall expression level that was not synchronized with the lighting cycle or between cells in the same retina. The axial variations of other membrane-associated fluorescent proteins, eGFP-containing two geranylgeranyl acceptor sites and eGFP fused to the transmembrane domain of syntaxin, were greatly reduced or not detectable, respectively. In acutely light-adapted rods, an arrestin-eGFP fusion protein also exhibited axial variation. Both the light-sensitive Rho-eGFP and arrestin-eGFP banding were in phase with the previously characterized birefringence banding (Kaplan, Invest. Ophthalmol. Vis. Sci. 21, 395–402 1981). In contrast, endogenous rhodopsin did not exhibit such axial variation. Thus, there is an axial inhomogeneity in membrane composition or structure, detectable by the rhodopsin transgene density distribution and regulated by the light cycle, implying a light-regulated step for disk assembly in the OS. The impact of these results on the use of chimeric proteins with rhodopsin fused to fluorescent proteins at the carboxyl terminus is discussed. 相似文献
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74.
Alice Kunzler Eduardo Antônio Kolling Jeferson Delgado da Silva-Jr Juciano Gasparotto Matheus Augusto de Bittencourt Pasquali José Cláudio Fonseca Moreira Daniel Pens Gelain 《Neurochemical research》2017,42(10):2788-2797
Retinoids (vitamin A and derivatives) are recognized as essential factors for central nervous system (CNS) development. Retinol (vitamin A) also was postulated to be a major antioxidant component of diet as it modulates reactive species (RS) production and oxidative stress in biological systems. Oxidative stress plays a major role either in pathogenesis or development of neurodegenerative diseases, or even in both. Here we investigate the role of retinol supplementation to human neuron-derived SH-SY5Y cells over RS production and biochemical markers associated to neurodegenerative diseases expressed at neuronal level in Parkinson’s disease and Alzheimer’s disease: α-synuclein, β-amyloid peptide, tau phosphorylation and RAGE. Retinol treatment (24 h) impaired cell viability and increased intracellular RS production at the highest concentrations (7 up to 20 µM). Antioxidant co-treatment (Trolox 100 µM) rescued cell viability and inhibited RS production. Furthermore, retinol (10 µM) increased the levels of α-synuclein, tau phosphorylation at Ser396, β-amyloid peptide and RAGE. Co-treatment with antioxidant Trolox inhibited the increased in RAGE, but not the effect of retinol on α-synuclein, tau phosphorylation and β-amyloid peptide accumulation. These data indicate that increased availability of retinol to neurons at levels above the cellular physiological concentrations may induce deleterious effects through diverse mechanisms, which include oxidative stress but also include RS-independent modulation of proteins associated to progression of neuronal cell death during the course of neurodegenerative diseases. 相似文献
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James I. Kirkland Luis Alcalá Mark A. Loewen Eduardo Espílez Luis Mampel Jelle P. Wiersma 《PloS one》2013,8(12)
Nodosaurids are poorly known from the Lower Cretaceous of Europe. Two associated ankylosaur skeletons excavated from the lower Albian carbonaceous member of the Escucha Formation near Ariño in northeastern Teruel, Spain reveal nearly all the diagnostic recognized character that define nodosaurid ankylosaurs. These new specimens comprise a new genus and species of nodosaurid ankylosaur and represent the single most complete taxon of ankylosaur from the Cretaceous of Europe. These two specimens were examined and compared to all other known ankylosaurs. Comparisons of these specimens document that Europelta carbonensis n. gen., n. sp. is a nodosaur and is the sister taxon to the Late Cretaceous nodosaurids Anoplosaurus, Hungarosaurus, and Struthiosaurus, defining a monophyletic clade of European nodosaurids– the Struthiosaurinae. 相似文献
77.
Funck Graciele Daiana de Lima Marques Juliana da Silva Dannenberg Guilherme dos Santos Cruxen Claudio Eduardo Sehn Carla Pohl Prigol Marina Silva Márcia Rósula Poetini da Silva Wladimir Padilha Fiorentini Ângela Maria 《Probiotics and antimicrobial proteins》2020,12(1):91-101
Probiotics and Antimicrobial Proteins - This study aimed to characterize, evaluate toxicity and optimize the conditions for the growth and production of bacteriocin-like substances by Lactobacillus... 相似文献
78.
Ailec Ho‐Plagaro Concepcin Santiago‐Fernandez Cristina Rodríguez‐Díaz Carlos Lopez‐Gmez Sara Garcia‐Serrano Francisca Rodríguez‐Pacheco Sergio Valdes Alberto Rodríguez‐Caete Guillermo Alcaín‐Martínez Natalia Ruiz‐Santana Luis Vzquez‐Pedreo Eduardo García‐Fuentes 《Obesity (Silver Spring, Md.)》2020,28(9):1708-1717
79.
Cesar B. Ramírez-López Rita Beltrán-Sánchez Alistair Hernández-Izquierdo José Luis SalvadorHernández Eduardo Salcedo-Pérez Rosa E. del Río Mauro M. Martínez Pacheco 《Phyton》2021,90(3):907-920
This study scrutinized the possibility of finding toxicant or deterrent plant metabolites against the dry wood termite Incisitermes marginipennis (Latreille). Plant deterrent agents act as repellents or antifeedants to prevent
wood decay and increase its useful life. The potential of the tree Caesalpinia coriaria (Fabaceae) as a biological
source of molecules with deterrent effects against the dry wood termite was assessed by a phytochemical fractionation guided by repellence and antifeedant activities. The gas chromatography-mass spectrometry analysis of the
leaf essential oil showed geraniol to be one of the major components and its repellent and antifeedant effects were
determined. Geraniol had only an antifeedant effect without affecting the body weight or survival of the dry wood
termite. Unlike the leaf essential oil, geraniol did not exhibit a repellency effect. An in-silico approach of the activity of acetylcholinesterase in interaction with geraniol resulted in an affinity energy of −7.5 Kcal/mol. Geraniol
interacted with the amino acid tyrosine 324 located in the enzyme’s active site while citronellol (negative control)
interacted with tryptophan 83 located adjacent to the active site. These deterring terpenes have not been implemented for the preservation and restoration of wood products exposed to the attack of the dry wood termite.
However, they are an important natural control alternative. 相似文献
80.
Choosing what scientific project to pursue is the most important decision that scientists at all levels continually face. Time devoted to a project can further desirable knowledge and advance a career or cost years in lost opportunity. Knowing what to consider before embarking on a specific scientific journey, as well as when to drop a project and change course, offers a way of practicing science that keeps us mindful of what is relevant at a given time and place while preserving our freedom to explore the most exciting findings. This article explores both the pressures that restrict this delicate decision-making process and the processes that scientists can apply to overcome those pressures. Above all else, as it turns out, we must still love the pursuit of knowledge for its own sake – and this love directly impacts our results. 相似文献