A novel, fast, low-cost and scalable methodology to prepare stable magnetoliposomes (MGLs), without the use of organic solvents, is described. The concept of the work is based on the dual use of soy lecithin associated to a new liposome preparation methodology. Soy lecithin was used to coat the nanoparticles of magnetite (Fe3 O4 @lecithin) and for encapsulation of Fe3 O4 @lecithin (Lip-Fe3 O4 @lecithin). Liposomes with size less than 160 nm, polydispersity index of 0.25 and zeta potential of -41 mV, were prepared with the use of autoclave and sonication. The liposomal formulations containing magnetite and stigmasterol (Lip-Fe3 O4 @lecithin, Lip-Stigma and Lip-Stigma-Fe3 O4 @lecithin) were shown to be promising for the application as antibacterial. The liposomal formulation and magnetite were characterized by the following techniques: conventional and high-resolution transmission electron microscopy (TEM/HRTEM), energy-filtered transmission electron microscopy (EFTEM), proton nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), dynamic light scattering (DLS) and zeta potential. The Lip-Fe3 O4 @lecithin had a minimum inhibitory concentration (MIC) of 8.4 µg mL-1 in the presence of 200 Oe magnetic field against S. aureus.

The kilovoltage radiotherapy is a recently re-implemented practice in the National Institute of Oncology and Radiology of Cuba to treat patients. One of the problems to approve its use is the assessment of risks associated to this practice. The present paper shows a summary of the pattern of accidental sequences proposed for this practice and its risk is quantified by using the risk matrix methodology. The SECURE-MR code has been used as the tool selected to implement such a practice. In addition to customary analysis facilities, this code has some other novel characteristics allowing us to establish the contributors’ priorities. The global results of the risk assessment for the proposed pattern, as well as some particular optimization practices are included in this paper

La radioterapia de kilovoltaje es una práctica de radioterapia de reciente reimplementación en el servicio de tratamiento del Instituto Nacional de Oncología y Radiología de Cuba. Uno de los aspectos relacionados con la autorización de su empleo es la evaluación de los riesgos asociados a dicha práctica. El siguiente artículo constituye un resumen del modelo de secuencias accidentales postuladas para la práctica, cuyo riesgo se cuantifica a través de la metodología de matriz de riesgo. El código SECURE-MR fue la herramienta seleccionada para implementar tal aplicación, por cuanto lo distinguen, además de las facilidades tradicionales de análisis, algunas novedosas que permiten el establecimiento de prioridades de contribuyentes. Los resultados globales de la evaluación de riesgo para el modelo postulado, así como algunas aplicaciones de optimización particulares se incluyen en el artículo

The chemiluminescence of zimosan-activated polymorphonuclears in the presence of alpha crystallins was determined (0,25; 0,5; 1 mg/mL) and the assay was performed with 1 mg/mL of the protein at 3 different moments (with pre-incubated alpha crystallin, with alpha crystallin added at the same time as zimosan and 8 minutes after adding the latter). Both the alpha crystallin preincubation with polymorphonuclears and its addition 8 minutes after the oxidative response occured significantly reduced chemiluminescence as compared to control. (p < 0,001; p < 0,005 respectively). Alpha crystallin caused a reduction that was 4 times that of the albumin of oxidized derivatives of thiobarbituric acid, dependig on the concentrations found. These preliminary result showed that alpha crystallin had an antioxidant activity since it lowers the reactive oxygen species of zimosan-activated neutrophils and inhibitis spontaneous lipid peroxidation in rat brain. Both antixiodant effects may contribute to crystallin lens protecction

Se determinó la quimioluminiscencia de polimorfonucleares activados con zimosán, en presencia de alfa-cristalina (0,25; 0,5; 1 mg/mL), y con 1 mg/mL de la proteína se efectuó el ensayo en 3 momentos diferentes (con alfa-cristalina preincubada, adicionada a la vez y después de 8 min de aplicado el zimosán). Tanto la preincubación de la alfa-cristalina con polimorfonucleares, como su adición 8 min después de desatada la respuesta oxidativa, disminuyeron significativamente la quimioluminiscencia respecto al control (p< 0,001; p < 0,005, respectivamente). La alfa-cristalina provocó una disminución 4 veces mayor que la albúmina de los derivados oxidados del ácido tiobarbitúrico, de manera dependiente de la concentración. Estos resultados preliminares demuestran que la alfa-cristalina tiene actividad antioxidante al disminuir las especies reactivas del oxígeno de neutrófilos activados con zimosán, e inhibir la lipoperoxidación espontánea de cerebro de rata. Ambos efectos antioxidantes pudieran contribuir a la protección del cristalino del ojo