Differential Response of BEAS-2B and H-441 Cells to Methylene Blue Photoactivation.

BACKGROUND/AIM: Cancer incidence and mortalities are growing worldwide, therefore research and development of more effective and less invasive treatments, such as photodynamic therapy, are needed. Herein, we investigated the methylene blue (MB) photoactivation effects in lung epithelial cells (BEAS-2B) and lung adenocarcinoma cells (H-441). MATERIALS AND METHODS: The reactive oxygen species (ROS) produced by the laser photoactivation of MB in aqueous solutions and cell cultures were measured with probes, and the cell viability was evaluated with a colorimetric assay. RESULTS: MB up to 31.26 µM did not induce detectable effects in BEAS-2B cells. However, H-441 cells presented adverse effects below that concentration in the same range of fluencies studied. These results are in concordance with the ROS production in H-441 cells, while in BEAS-2B cells the production of ROS was less significant compared to the control. CONCLUSION: Photoactivation of MB at concentrations below 31.26 µM could be used for the selective treatment of H-441 cells over non-cancer cells.

Mathematical modeling and parametrical analysis of the temperature dependency of control drug release from biodegradable nanoparticles.

In this study we describe a mathematical analysis that considers the temperature effects of the controlled drug release process from biodegradable poly-d,l-lactide-co-glycolide (PLGA) nanoparticles. Temperature effects are incorporated and applied to two drug release models. The first one consists of a two-stage release process that considers only simultaneous contributions of initial burst and nanoparticle degradation-relaxation (BR model). The second one is a three release stage model that considers, additionally, a simultaneous drug diffusion (BRD model) step. In these models, the temperature dependency of the release parameters, initial burst constant, k b, the rate of degradation-relaxation constant, k r, time to achieve 50% of release, t max, and effective diffusion coefficient constant (D e), are determined using mathematical expressions analogous to the Arrhenius equation. The temperature dependent models are used to analyze the release of previously encapsulated Rhodamine 6G dye as a model drug in polyethylene glycol modified PLGA nanoparticles. The experimental data used to develop the mathematical model was obtained from release studies carried out in phosphate buffer pH 7.4 at 37 °C, 47 °C, and 57 °C. Multiphasic release behaviors with an overall increase rate associated with the incubation temperature were observed. The study incorporates a parametrical analysis that can evaluate diverse temperature variation effects of the controlled release parameters for the two models.

Calcific tendinitis of the prevertebral space: a case report.

Calcific prevertebral tendinitis is a self-limiting inflammatory condition of the prevertebral space that involves the insertion of the longus colli tendon. Understanding this condition and its characteristic imaging findings is essential for early diagnosis and differentiation of the disorder from other acute conditions. We describe a case of a 40-year-old patient who presented to the emergency department with severe odynophagia and exhibited the computed tomography findings necessary to confirm this disease.

Novel hydrophobic interaction chromatography matrix for specific isolation and simple elution of immunoglobulins (A, G, and M) from porcine serum.

A new, highly acetylated agarose matrix (HA-Sepharose) was synthesized and used as a hydrophobic interaction chromatography (HIC) medium to specifically isolate immunoglobulins (Igs) from porcine serum. Recovery of Igs was in a single step and under mild conditions. HA-Sepharose adsorption was studied in terms of salt, gel acetylation time, flow rate, and protein concentration on the loading buffer. At 0.5 M Na2SO4, control with unmodified Sepharose retained a small fraction (0.70 mg/mL of matrix) of serum albumin. On the contrary HA-Sepharose retained primary Igs (IgA, IgG, and 53% of IgM) as revealed by sodium dodecyl sulphate 10% polyacrylamide gel electrophoresis (SDS-PAGE), quantitative radial immunodiffusion and immunodetection. At a flow rate of 1 mL/min, the HA-Sepharose column capacity (3.9 mg/mL of matrix) was similar to the reported capacity for the commercial thiophilic T-gel. However, HA-Sepharose showed higher recovery of IgA and IgM than the T-gel in the same salt conditions, clearly an advantage in terms of immunoglobulin recovery strategies. Acetylation changed the matrix adsorption from albumin to immunoglobulins; thus, the highly acetylated gel rendered recoveries of Igs from unprocessed porcine serum practically free of albumin.

La gnatostomiasis en México / Gnathostomiasis in Mexico

A partir de 1975 se empezaron a observar,primero en las ciudades de Temazcal,Oaxaca,y Tierra Blanca, Veracruz, y luegoen otras de la cuenca del río Papaloapan, un número creciente de enfermos con edema inflamatoriosmigratorios, fugaces y recidivantes; el número de enfermos se acerca actualmente a los 200. La infección se ha relacionado siempre con la ingestión de pescados cíclidos de la presa Miguel Alemán, y consumidos en forma de ceviche, es decir, no tratados por el calor. La especie implicada, aunque aún no identificada con absoluta seguridad, debe ser muy cercana a Gnathostoma spinigerum. Se describen los cambios ecológicos y sociales que la construcción de la presa produjo y que se piensa puedan estar relacionados con la diseminación del parásito en la región. El Centro Piscicola de Temazcal proporcionó tilapias a muchos criaderos secundarios en diversas partes de la República, lo que hace tener que la infección se propague en una forma generalizada. En este trabajo, se describen minuciosamente las diversas formas de la enfermedad, para que los médicos mexicanos puedan reconocerla si llegara a presentarse