Biological Activity of Genistein and Soy Extracts: Selective Induction of some but not all Estrogenic Responses in the Prepubertal Rat Uterus [Actividad biológica de Genisteína y extractos de soya: inducción selectiva de algunas pero no todas las respuest

La existencia de múltiples tipos de receptores de estrógeno (ERs), involucrados en el desarrollo de grupos independientes de respuestas a estrógeno, permite su disociación y abre la posibilidad de inducir en forma selectiva respuestas benéficas pero no aquellas consideradas de riesgo (proliferación celular). Basado en la baja mortalidad por cánceres hormono-dependientes en el Este Asiático, atribuidos a una alta ingesta dietaria de isoflavonas estrogénicas, nosotros investigamos si la genisteína (G) o extractos de soja (S) inducen en forma selectiva algunas, pero no todas, las respuestas estrogénicas en el útero de rata, comparando su actividad con la del estradiol-17β (E2). Ratas prepuberales fueron tratadas con E2, G, S concentrado (Sc), S diluido (Sd) o vehículo, y las respuestas estrogénicas en el útero fueron evaluadas. Las hipertrofias celulares en epitelio luminal y miometrio, y el aumento de ARN en células del epitelio luminal fueron inducidas por E2, G o S. La eosinofilia uterina, el edema en estroma endometrial y la proliferación de 4 tipos celulares uterinos fueron inducidos sólo por E2. Los resultados revelan que G y S inducen algunas respuestas estrogénicas pero no otras, sugiriendo su uso terapéutico como agentes estrogénicos que no presentan riesgo de cáncer

Effect of Prenatal Exposure to Lead on Estrogen Action in the Prepubertal Rat Uterus

Lead is a widely spread environmental pollutant known to affect both male and female reproductive systems in humans and experimental animals and causes infertility and other adverse effects. The present paper investigated the effects of prenatal exposure to lead on different parameters of estrogen stimulation in the uterus of the prepubertal rat. In prenatally and perinatally exposed rats, estrogen-induced endometrial eosinophilia, endometrial stroma edema, and eosinophil migration towards the endometrium, and uterine luminal epithelial hypertrophy are enhanced while several other responses to estrogen appear unchanged. These effects may contribute to decrease in fertility following prenatal exposure to lead. The striking difference between most of these effects of prenatal exposure and the previously reported effects of chronic exposure to lead suggests that prenatal exposure to lead may neutralize the effects of chronic exposure to lead, providing partial protection of cell function against the adverse effects of chronic exposure to lead. We propose that the mechanism involved, named imprinting or cell programming, persisted through evolution as a nongenetic adaptive mechanism to provide protection against long-term environmental variations that otherwise may cause the extinction of species not displaying this kind of adaptation

Modified plasma waves described by a logarithmic electrodynamics

The propagation of plasma waves in a new non-linear, logarithmic electrodynamics model is performed. A cold, uniform, collisionless fluid plasma model is applied. Electrostatic waves in magnetized plasma are shown to correspond to modified Trivelpiece-Gould modes, together with changes of the plasma and upper-hybrid frequencies, driven by the logarithmic electrodynamics effects. Electromagnetic waves are described by a generalized Appleton-Hartree dispersion relation. The cases of propagation parallel or perpendicular to the equilibrium magnetic field are analyzed in detail. In particular, generalized ordinary and extraordinary modes are obtained. We determine the changes, due to logarithmic electrodynamics, in the allowable and forbidden frequency bands of the new extraordinary mode. Estimates are provided about the strength of the ambient magnetic field, so that the non-linear electrodynamics effects become decisive

Black holes in an ultraviolet complete quantum gravity

In this Letter we derive the gravity field equations by varying the action for an ultraviolet complete quantum gravity. Then we consider the case of a static source term and we determine an exact black hole solution. As a result we find a regular spacetime geometry: in place of the conventional curvature singularity extreme energy fluctuations of the gravitational field at small length scales provide an effective cosmological constant in a region locally described in terms of a de Sitter space. We show that the new metric coincides with the noncommutative geometry inspired Schwarzschild black hole. Indeed, we show that the ultraviolet complete quantum gravity, generated by ordinary matter is the dual theory of ordinary Einstein gravity coupled to a noncommutative smeared matter. In other words we obtain further insights about that quantum gravity mechanism which improves Einstein gravity in the vicinity of curvature singularities. This corroborates all the existing literature in the physics and phenomenology of noncommutative black holes.Comment: 5 pages, 2 figures, minor corrections, version matching that published by Physics Letters

Equol y daidzeina disminuyen la migración, invasión y la expresión génica de metaloproteinasa de la matriz (MMPs) en las líneas celulares prostáticas cancerosas DU-145 y PC-3

Este trabajo se centra en el estudio de los compuestos de dieta que pueden tener potencial efecto quimiopreventivo contra el cáncer. Algunos de estos compuestos son los fitoestrógenos. Entre ellos encontramos la genisteína (1), el más estudiado, la daidzeína (2) y el equol (3) (figura 1). Para comparar el efecto de estos fitoestrogenos sobre las líneas celulares de cáncer de próstata, DU-145 y PC-3, se utilizó el ensayo de sulforodamina B para determinar la viabilidad celular tras los tratamientos con diferentes concentraciones de fitoestrógenos (0-12.5-25-50-100 μM) durante diferentes tiempos (24, 48, 72 h). Para analizar el efecto sobre la migración celular, las células DU-145 y PC-3 fueron tratadas previamente con una concentración de fitoestrógrno (50 μM) durante 24 horas y sembradas en una cámara Transwell sin recubrir. El estudio mostró que el equol, daidzeína y genisteína inhibió en MMP-2 y MMP-9 expresiones de genes en líneas celulares de cáncer de próstata, la PC-3 y DU-145. Los resultados indicaron que la daidzeína disminuyó la expresión de MMP- 2 y MMP-9 en DU-145 células. Nuestros datos sugieren que equol, daidzeína y genisteína inhiben la migración y la invasión de líneas celulares de cáncer de próstata

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Manual de diseno de sistemas de riego tecnificado

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Modified plasma waves described by a logarithmic electrodynamics

The propagation of plasma waves in a new nonlinear, logarithmic electrodynamics model is performed. A cold, uniform, collisionless fluid plasma model is applied. Electrostatic waves in magnetized plasma are shown to correspond to modified Trivelpiece-Gould modes, together with changes in the plasma and upper-hybrid frequencies, driven by the logarithmic electrodynamics effects. Electromagnetic waves are described by a generalized Appleton-Hartree dispersion relation. The cases of propagation parallel or perpendicular to the equilibrium magnetic field are analyzed in detail. In particular, generalized ordinary and extraordinary modes are obtained. We determine the changes, due to logarithmic electrodynamics, in the allowable and forbidden frequency bands of the new extraordinary mode. Estimates are provided about the strength of the ambient magnetic field so that the nonlinear electrodynamics effects become decisive