El avance científico-técnico de la sociedad está potenciado por el desarrollo investigativo de las universidades, constituyendo una necesidad la correspondencia entre ambos elementos; de ahí que cada ...experiencia o aporte en todas las ramas del saber deban formar parte de soluciones específicas o ser aplicaciones inmediatas. En las Ciencias Médicas y en el sector de la salud en general, el avance de las tecnologías de la información y las comunicaciones dinamiza su progreso y se requiere mantener la superación postgraduada de sus profesionales acorde al proceso de informatización de nuestros días. Se muestra en el presente trabajo la experiencia cubana en los estudios de la maestría Informática en Salud con numerosas aplicaciones para la docencia y la gestión en salud donde se ratifica que el proceso investigativo universitario es un surtidor para el desarrollo de la sociedad.The scientific and technical development of society is increased by the investigative development of universities, being a most the correspondence between both elements, therefore, every experience, every hand out in all the knowledge branches must conform part of specific solutions to be immediately applied. In medical sciences and health sector in general, the advance in communications and information’s technologies make its process a dynamic one and it is required to maintain the postgraduate development of the professionals according to the Informatization process of the current days. In this article, it is shown the Cubanos experience in studies in the mastership of Informatics health with numberless applications for docency and health management where it is repeated that the universitary investigative process is a real provider for society’s development.
Mutation of L125R in trasmembrane helix III of rhodopsin, associated with the retinal degenerative disease retinitis pigmentosa, was previously shown to cause structural misfolding of the mutant ...protein. Also, conservative mutations at this position were found to cause partial misfolding of the mutant receptors. We report here on a series of mutations at position 125 to further investigate the role of Leu125 in the correct folding and function of rhodopsin. In particular, the effect of the size of the substituted amino‐acid side chain in the functionality of the receptor, measured as the ability of the mutant rhodopsins to activate the G protein transducin, has been analysed. The following mutations have been studied: L125G, L125N, L125I, L125H, L125P, L125T, L125D, L125E, L125Y and L125W. Most of the mutant proteins, expressed in COS‐1 cells, showed reduced 11‐cis‐retinal binding, red‐shifts in the wavelength of the visible absorbance maximum, and increased reactivity towards hydroxylamine in the dark. Thermal stability in the dark was reduced, particularly for L125P, L125Y and L125W mutants. The ability of the mutant rhodopsins to activate the G protein transducin was significantly reduced in a size dependent manner, especially in the case of the bulkier L125Y and L125W substitutions, suggesting a steric effect of the substituted amino acid. On the basis of the present and previous results, Leu125 in transmembrane helix III of rhodopsin, in the vicinity of the β‐ionone ring of 11‐cis‐retinal, is proposed to be an important residue in maintaining the correct structure of the chromophore binding pocket. Thus, bulky substitutions at this position may affect the structure and signallling of the receptor by altering the optimal conformation of the retinal binding pocket, rather than by direct interaction with the chromophore, as seen from the recent crystallographic structure of rhodopsin.
L125R is a mutation in the transmembrane helix C of rhodopsin that is associated with autosomal dominant retinitis pigmentosa. To probe the orientation of the helix and its packing in the ...transmembrane domain, we have prepared and studied the mutations E122R, I123R, A124R, S127R, L125F, and L125A at, and in proximity to, the above mutation site. Like L125R, the opsin expressed in COS-1 cells from E122R did not bind 11-cis-retinal, whereas those from I123R and S127R formed the rhodopsin chromophore partially. A124R opsin formed the rhodopsin chromophore ( lambda sub(max) 495 nm) in the dark, but the metarhodopsin II formed on illumination decayed about 6.5 times faster than that of the wild type and was defective in transducin activation. The mutant opsins from L125F and L125A bound 11-cis-retinal only partially, and in both cases, the mixtures of the proteins produced were separated into retinal-binding and non-retinal-binding (misfolded) fractions. The purified mutant rhodopsin from L125F showed lambda sub(max) at 500 nm, whereas that from L125A showed lambda sub(max) at 503 nm. The mutant rhodopsin L125F showed abnormal bleaching behavior and both mutants on illumination showed destabilized metarhodopsin II species and reduced transducin activation. Because previous results have indicated that misfolding in rhodopsin is due to the formation of a disulfide bond other than the normal disulfide bond between Cys-110 and Cys-187 in the intradiscal domain, we conclude from the misfolding in mutants L125F and L125A that the folding in vivo in the transmembrane domain is coupled to that in the intradiscal domain.
The conformational changes of polyd(A-C) times polyd(G-T) induced by Hg(ClO sub(4)) sub(2) in aqueous solution have been studied using UV absorption and fourth derivative spectrophotometries, and ...FTIR spectroscopy. The UV absorption and fourth derivative spectra reflect changes in the polynucleotide stacking interactions as a result of the metal-polynucleotide interaction. The fourth derivative spectra do not indicate a Z-form either at low or at high metal-to-polynucleotide ratios. Furthermore, the infrared spectrum at high metal-to-polynucleotide ratio (r = 1.2; r = Hg(ClO sub(4)) sub(2)/nucleotide molar ratio) has the main features of an A-form, in contrast with previous CD studies which proposed that the polynucleotide adopts a Z-form under these conditions. The nature of a different conformation of the polynucleotide induced at low r-ratios (r less than or equal to 0.2) is discussed.
The conformational changes of polyd(A-C)·polyd(GT) induced by Hg(CiO
4)
2 in aqueous solution have been studied using UV absorption and fourth derivative spectrophotometries, and FTIR spectroscopy. ...The UV absorption and fourth derivative spectra reflect changes in the polynucleotide stacking interactions as a result of the metal-polynucleotide interaction. The fourth derivative spectra do not indicate a Z-form either at low or at high metal-to-polynucleotide ratios. Furthermore, the infrared spectrum at high metal-to-polynucleotide ratio
(r = 1.2; r =
Hg(
ClO
4)
2
nucleotide molar ratio)
has the main features of an A-form, in contrast with previous CD studies which proposed that the polynucleotide adopts a Z-form under these conditions. The nature of a different conformation of the polynucleotide induced at low
r-ratios (
r < 0.2) is discussed.
The effect of the naturally occurring polyamines spermidine and spermine on poly(amino2-dA-dT).poly(amino2dA-dT) conformation has been studied by UV, CD, and IR spectroscopies. It is shown that a ...conformational transition is induced in poly(amino2dA-dT).poly(amino2dA-dT) by micromolar concentrations of the polyamines (30 microM) in low-salt aqueous solution. The analysis of our results, in view of previously published studies on conformational properties of the amino polynucleotide, indicates the resulting conformer to be an A-form. Interestingly, the polyamine concentration at the midpoint of the transition is the same in both cases. This provides further evidence that the coordination of positively charged counterions to DNA is determined largely from the DNA structure, probably with an important role for the sequence, and less from the nature of the ions.
Novel approaches involving new specimen preparation methods, 18O tracer experiments and secondary ion mass spectrometry have been developed to determine the high-temperature oxidation mechanisms and ...kinetics of gas turbine blades. The industrial gas turbine blades investigated in this work consisted of an oxide–Si-aluminide coating–directionally solidified nickel-based superalloy system. The oxide scales were characterised after various exposure times from 0 to 15 000 h in a gas turbine environment and also after laboratory annealing in oxygen atmospheres (16O2 and 18O2) at high temperature. The oxide and coating layers were analysed by micro-machining cross-sections on the surface of the blades using a Ga+ focused ion beam system (FEI-FIB200) combined with secondary ion mass spectroscopy. The powerful milling technique and the sub-micron resolution of the focused ion beam instrument, widely used within the semiconductor industry, were successfully adapted to our study. The FIB200 experiments provided essential results concerning the microstructural evolution of the oxide during high-temperature exposure yielding the thickness, the porosity, the pathways of diffusion, the chemical composition and the distribution of the different phases present in these layers. Further annealing experiments at high-temperature were also performed in an atmosphere enriched with the stable oxygen isotope 18O2 to determine the oxygen diffusion mechanism through the oxide scale. The oxygen diffusion characteristics were investigated by depth profiling and imaging (elemental mapping 16O− and 18O−) using conventional and high-resolution SIMS (ATOMIKA 6500, FIB200). An Atomic Force Microscope (Quesent Resolver) and an Interferometric Optical Microscope (Zygo) were used to measure the SIMS craters for depth calibration. The combination of these high-resolution methods has provided a basis for a fundamental understanding of the oxidation behaviour of the protective coatings on superalloys.
9-Aminoacridine is the parent compound of a family of pharmacologically active model substances that bind to DNA through intercalation between base pairs. In the present study we show that ...9-aminoacridine inhibits the B-to-Z isomerization of poly(dA-dT) in conditions that otherwise cause it to occur (5 M NaCl and 123 mM Ni(ClO4)2). Higher concentrations of Ni(ClO4)2 (155 mM) are able to induce the Z-form due to the disruption of the drug-polynucleotide interaction by the metal ion. Additionally, the dye reverses the Z-form in certain conditions. Thus, the data from this study indicate that 9-aminoacridine binds preferentially to the B-form of poly(dA-dT).
El avance científico-técnico de la sociedad está potenciado por el desarrollo investigativo de las universidades, constituyendo una necesidad la correspondencia entre ambos elementos; de ahí que cada ...experiencia o aporte en todas las ramas del saber deban formar parte de soluciones específicas o ser aplicaciones inmediatas. En las Ciencias Médicas y en el sector de la salud en general, el avance de las tecnologías de la información y las comunicaciones dinamiza su progreso y se requiere mantener la superación postgraduada de sus profesionales acorde al proceso de informatización de nuestros días. Se muestra en el presente trabajo la experiencia cubana en los estudios de la maestría Informática en Salud con numerosas aplicaciones para la docencia y la gestión en salud donde se ratifica que el proceso investigativo universitario es un surtidor para el desarrollo de la sociedad.
Retinitis pigmentosa is a group of retinal degenerative diseases, within the broad family of hereditary retinopathies, for which there is no cure at present. Mutations in different genes coding for ...proteins related to the metabolism of photoreceptor cells, and to the visual phototransduction cascade, are the cause of this disease. Rhodopsin, the photoreceptor protein responsible for light absorption--and key in the first stages of vision--is one of the most studied molecules of the retina. Mutations in the opsin gene account for about 25% of all cases of autosomal dominant retinitis pigmentosa. Recent crystallization of this receptor in its inactive dark state has revealed new structural details yielding further insights into the intra and intermolecular mechanismsin which the protein is involved as a result of its activation.Furthermore, the in vitro study of recombinant rhodopsins carrying mutations previously found in retinitis pigmentosa patients (by means of spectroscopic and functional techniques) has shed new light on the structural requirements for its correct function, as well as the molecular defects underlying the mechanism of photoreceptor cell death. In this study, the main findings of the recent investigations carried out in this field are presented. The relevant information obtained at the molecular level is bound to facilitate our understandingof the molecular processes that will allow suitable therapiesfor different retinal degenerative diseases, particularly retinitis pigmentosa, to be proposed.
![An A-form of poly[d(A-C)] t...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0014-5793/small "An A-form of poly[d(A-C)] times poly[d(G-T)] induced by mercury (II) as studied by UV and FTIR spectroscopies")
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