Criopreservación de semen bovino de la cola del epididimo utilizando los métodos convencional y automatizado

Cryopreservation of sperm is important to preserve the germplasm from animals of genetic value, which can die unexpectedly. This study compares conventional and automated methods of cryopreservation of spermatozoa obtained from the epididymis of bulls post-mortem. Twenty-two epididymides were obtained from a commercial slaughterhouse. Spermatozoa were collected from the tail of the epididymis using the retrograde flow technique. Thus, the samples, which were diluted in 10 ml of extender without glycerol (Botubov® I, Botupharma, Botucatu, SP, Brazil), were evaluated on motility, sperm vigor, structural and functional (swelling hypoosmotic test) membrane integrity, mitochondrial activity, sperm viability and ADN fragmentation. The samples were divided into two aliquots and diluted in extender with glycerol (Botubov® II, Botupharma, Botucatu, SP, Brazil) at a concentration of 50x106 motile sperm/0.5 French straws. One sample was frozen by the conventional method (4 hours at 5°C, in a refrigerator and 20 min in nitrogen vapor) and the other by the automated method (Cryogen® Dualflex, Neovet, Uberaba, MG, Brazil). The parameters were higher in all the tests of fresh sperm samples, with the exception of the swelling hypoosmotic test, which showed no significant difference when the results were compared with sperm frozen by the conventional method. The average motility of fresh spermatozoa was 74%, and conventional and automated averages were 29 and 25%, respectively. Therefore, although cryopreservation techniques reduce sperm quality parameters, the viability of the sperm is maintained, and these methods can be used to preserve sperm.

Análise molecular de pacientes com holoprosencefalia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise molecular de pacientes com holoprosencefalia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Time course of the hemodynamic responses to aortic depressor nerve stimulation in conscious spontaneously hypertensive rats

The time to reach the maximum response of arterial pressure, heart rate and vascular resistance (hindquarter and mesenteric) was measured in conscious male spontaneously hypertensive (SHR) and normotensive control rats (NCR; Wistar; 18-22 weeks) subjected to electrical stimulation of the aortic depressor nerve (ADN) under thiopental anesthesia. The parameters of stimulation were 1 mA intensity and 2 ms pulse length applied for 5 s, using frequencies of 10, 30, and 90 Hz. The time to reach the hemodynamic responses at different frequencies of ADN stimulation was similar for SHR (N = 15) and NCR (N = 14); hypotension = NCR (4194 +/- 336 to 3695 +/- 463 ms) vs SHR ( 3475 +/- 354 to 4494 +/- 300 ms); bradycardia = NCR (1618 +/- 152 to 1358 +/- 185 ms) vs SHR (1911 +/- 323 to 1852 +/- 431 ms), and the fall in hindquarter vascular resistance = NCR (6054 +/- 486 to 6550 +/- 847 ms) vs SHR (4849 +/- 918 to 4926 +/- 646 ms); mesenteric = NCR (5574 +/- 790 to 5752 +/- 539 ms) vs SHR (5638 +/- 648 to 6777 +/- 624 ms). In addition, ADN stimulation produced baroreflex responses characterized by a faster cardiac effect followed by a vascular effect, which together contributed to the decrease in arterial pressure. Therefore, the results indicate that there is no alteration in the conduction of the electrical impulse after the site of baroreceptor mechanical transduction in the baroreflex pathway (central and/or efferent) in conscious SHR compared to NCR.

Alteraciones genéticas y epigenéticas en el cáncer de endometrio

Programa de doctorado: Cáncer: biología y clínica.

Efecto citotóxico de la melatonina en células de leucemia humana Molt-3

Programa de doctorado: Clínica e Investigación Terapéutica.

Genetic divergence of tanaidaceans (Crustacea: Peracarida) with low dispersal ability

[EN] In this study, the phylogeographic patterns of nuclear, ribosomal and mtDNA gene fragments of five tanaidacean species (Zeuxo, Tanaidae) from the Atlantic, Pacific and Mediterranean Sea were investigated.

Dinámicas cognitivas de la complejidad poética y lingüística del concepto "TIEMPO". Modelización conceptual en el texto de T.S. Eliot."The Waste Land" (1992)

Programa de doctorado: Nuevas perspectivas cognitivas en los estudios de lengua, literatura, y traducción. Tesis doctoral europea

Aprendizaje interactivo con imágenes soportadas mediante página web como complemento formativo en el ámbito de la Biología Celular

[ES]Este artículo expone la experiencia recogida tras el desarrollo de una página web en formato atlas con las imágenes de las prácticas de aula para las distintas asignaturas en el ámbito de la Biología Celular. Los estudiantes son usuarios habituales de las nuevas tecnologías de la información y la comunicación (TIC) para consumo y ocio pero usuarios potenciales para innovadoras formas de interacción, estudio e investigación. Las actividades basadas en web, que pueden englobarse dentro de las tareas propias de las metodologías activas, son aplicadas en asignaturas de nuestra área que depende en gran medida de la imagen en todas sus posibles presentaciones dado su carácter morfológico. El objetivo es mostrar cómo esta actividad se ha implementado en el campo de la Biología Celular y presentar su aporte a la calidad de la enseñanza desde el punto de vista tanto de la participación del estudiante como del autoestudio. Los resultados revelan una participación más activa y una mayor implicación de los estudiantes , quedando incorporado en su ADN formativo como herramienta habitual de apoyo didáctico siendo valorados los resultados como satisfactorios.

Modulation of cytochrome P450 enzyme activity and PAH -induced skin carcinogenesis by naturally occurring coumarins

The present study was designed to determine the potential anticarcinogenic activity of naturally occurring coumarins and their mechanism of action. The results indicated that several naturally occurring coumarins including bergamottin, coriandrin, imperatorin, isopimpinellin, and ostruthin, to which humans are routinely exposed in the diet, were effective inhibitors and/or inactivators of CYP1A1-mediated ethoxyresorufin-O-dealkylase (EROD) or CYP2B1-mediated pentoxyresorufin-O-dealkylase (PROD) in mouse liver microsomes. In addition, bergamottin and corandrin were also found to be inhibitors of purified human P450 1A1 in vitro. Further studies with coriandrin revealed that this compound was a mechanism-based inactivator of P450 1A1 and covalently bound to the P450 1A1 apoprotein. In cultured mouse keratinocytes, bergamottin and coriandrin effectively inhibited the B(a) P metabolism and significantly decreased covalent binding of B(a) P and DMBA to keratinocyte DNA and anti-diol-epoxide-DNA adducts derived from both B(a) P and DMBA in keratinocytes. The data from in vivo experiments showed that bergamottin and coriandrin were potent inhibitors of covalent binding of B (a) P to epidermal DNA and the formation of (+) anti BPDE-DNA adduct, whereas imperatorin and isopimpinellin were more potent inhibitors of covalent binding of DMBA to epidermal DNA. The ability of coumarins to inhibit covalent binding of B (a) P to DNA in mouse epidermis was positively correlated with their inhibitory effect P450 1A1 in vitro, while the inhibitory effect of coumarins on covalent binding of DMBA to epidermal DNA was positively correlated with their inhibitory effects on P450 2B1 and negatively to their inhibitory activity toward P450 1A1. The data from tumor experiments indicated that bergamottin, ostruthin, and coriandrin inhibited tumor initiation by B (a) P in a two-stage carcinogenesis protocol. Bergamottin was most effective in this regard and produced a dose dependent inhibition of papilloma formation in these experiments. In addition, imperatorin was an effective inhibitor of skin tumorigenesis induced by DMBA in SENCAR mouse skin using both a two-stage and a complete carcinogenesis protocol. At dose levels higher than those effective against DMBA, imperatorin also inhibited tumor initiation by B (a) P. The results to date demonstrate that several naturally occurring coumarins possess the ability to block tumor initiation and tumorigenesis by PAHs such as B (a) P and DMBA through inhibition of the P450s involved in the metabolic activation of these hydrocarbons. A working model for the involvement of specific P450s in the metabolic activation of these two PAHs was proposed. ^

La redención en Buenos Aires

En “De las alegorías a las novelas", Jorge Luis Borges ensayaba una distinción entre ambas y al mismo tiempo, trazaba una zona de ambigua coexistencia dejando así abierta la posibilidad de entrelazar aquello que “dicho de otro modo", que en el sentido etimológico de la alegoría (oscuro ingenio, en la concepción de Sir Edmond Spenser); con lo que se supone propio de la narrativa en relación con lo particular, en oposición a lo genérico o conceptual que suele adscribirse a la alegoría continuando la definición (negativa) del romanticismo. La revisión del término por parte de Walter Benjamin, Edward Honig o Arthur Fletcher, lo mismo el texto de Borges, incitan a una reconsideración de “lo alegórico" en sus posibilidades narrativas en la literatura contemporánea. Nos proponemos examinar esta cuestión tomando como texto paradigmático el Adán Buenosayres de Leopoldo Marechal en un análisis que al mismo tiempo que considera la función y sentido de lo alegórico en el texto de este último, examina los alcances de la categoría ampliando su marco según las nuevas perspectivas mencionadas y las posibilidades que ofrece el texto literario.