Eva Aladro Vico

Design and characterization of an ocular topical liposomal preparation to replenish the lipids of the tear film.

PURPOSE Dry eye (DE) includes a group of diseases related to tear film disorders. Current trends for DE therapy focus on providing lipid components to replace the damaged lipid layer. Formulations that contain aqueous and mucin-like compounds may have additional therapeutic benefits for DE patients. The aim of this work was to design and evaluate novel formulations having the potential to become topical treatment for DE. METHODS Unpreserved liposomal formulations composed of phosphatidylcholine (PC), cholesterol, and α-tocopherol (vit E) were prepared by the thin-film hydration technique. Formulations were characterized in terms of liposome size, pH, surface tension, osmolarity, and viscosity. In vitro tolerance assays were performed on macrophage, human corneal, and conjunctival cell lines at short- and long-term exposures. In vivo ocular tolerance was studied after instillation of the formulation. RESULTS The mean liposome size was less than 1 μm and surface tension < 30 mN/m for all formulations. The final liposomal formulation (PC-cholesterol-vit E in a ratio of 8:1:0.8) had physiological values of pH (6.45 ± 0.09), osmolarity (289.43 ± 3.28 mOsm), and viscosity (1.82 ± 0.02 mPa · s). Cell viability was greater than 80% in the corneal and conjunctival cells. This formulation was well tolerated by experimental animals. CONCLUSIONS The unpreserved liposomal formulation has suitable properties to be administered by a topical ophthalmic route. The liposome-based artificial tear had good in vitro and in vivo tolerance responses. This formulation, composed of a combination of liposomes and bioadhesive polymers, may be used successfully as a tear film substitute in DE therapy.

Espacio Interpersonal, Sistemas de Conducta y Escaladas

Este articulo explora los nuevos avances en la investigacion de la comunicacion interpersonal en diversos campos psicologicos y sociales, mostrando la poderosa influencia de esta dimension de la comunicacion sobre la consciencia humana, y la gran cantidad de fenomenos que indican que la dimension interpersonal de la comunicacion es fundamental para el control y desarrollo de las relaciones humanas.

Novel Nano-Liposome Formulation for Dry Eyes with Components Similar to the Preocular Tear Film

Dry eye is commonly treated with artificial tears; however, developing artificial tears similar to natural tears is difficult due to the complex nature of tears. We characterized and evaluated a novel artificial tear formulation with components similar to the lipid and aqueous constituents of natural tears. Nano-liposomes, composed in part of phosphatidylcholine, were dispersed in an aqueous solution of bioadhesive sodium hyaluronate. Liposome size, zeta potential, and physicochemical properties of the fresh and stored (4 °C) liposomal formulation were analyzed. In vitro tolerance was tested using human corneal and conjunctival cell lines by exposures of 15 min to 4 h. The tolerance of the liposomal formulation was evaluated in animals (rabbits). The average liposome size was 186.3 ± 7.0 nm, and the zeta potential was negative. The osmolarity of the formulation was 198.6 ± 1.7 mOsm, with a surface tension of 36.5 ± 0.4 mN/m and viscosity of 3.05 ± 0.02 mPa·s. Viability values in the human corneal and conjunctival cell lines were always >80%, even after liposomal formulation storage for 8 weeks. Discomfort and clinical signs after instillation in rabbit eyes were absent. The new formulation, based on phosphatidylcholine-liposomes dispersed in sodium hyaluronate has suitable components and characteristics, including high in vitro cell viability and good in vivo tolerance, to serve as a tear substitute.

El lenguaje digital, una gramática generativa

Este texto es una investigacion en profundidad sobre las composiciones digitales de multiples elementos que aqui son considerados un unico lenguaje digital. Siguiendo la idea de Manovich, reflexionamos sobre como este lenguaje trabaja con una gramatica transformacional o generativa cuyos elementos fundamentales y operaciones basicas se centran en el uso de lenguaje previos en operaciones proyectivas y metaforizantes, asi como en fusiones conceptuales, que utilizan las estructuras profundas de las gramaticas de los medios del siglo XX para producir composiciones creativas en transformacion constante. Se enuncian algunas de las matrices y metaforas fundamentales de este lenguaje como el mapa escalable, el contenedor, las metaforas ontologicas y las orientacionales y espaciales.

Comunicación como traducción

This text reflect upon the fundamental fact that every original communication is really a translation. It analyses the phenomenon of the expression as something that has to do with the acceptance of the indirect nature of every language, to the basic cooperation that expressive activity implies. Following the theories of P. Grice or L. Vygotsky, the paper exposes some ideas about the fundamentals of the community of meaning between speakers and audiences.

Umbrales, analogía e incubación en el tratamiento de la información

Se resumen y comentan tres teorias basicas en analisis cognitivo, la teoria del umbral de carga perceptivo y cognitivo, la teoria de la incubacion creativa y la teoria sobre la influencia del pensamiento analogico en la mente humana y se obtienen diversas conclusiones de ese analisis comparativo.