Historia del dopaje en el beisbol mundial / História do doping no beisebol mundial / History of doping in world baseball

RESUMEN Introducción: El béisbol ha estado constantemente bajo la amenaza del dopaje, y actualmente existen criterios emitidos por algunos expertos que sugieren la posibilidad de que muchos éxitos alcanzados por famosos beisbolistas que en nuestros días aparecen como las principales grandes estrellas de este deporte en el salón de la fama, hayan estado relacionados con el consumo de sustancias prohibidas. Objetivo: El objetivo del presente estudio fue explorar los datos publicados en la bibliografía mundial especializada que revelan cómo el dopaje, así como otras formas de fraudes, han afectado al beisbol tanto en las categorías de mayores como en las menores. Materiales y métodos: El presente trabajo de revisión bibliográfica se realiza como una sugerencia de aficionados al béisbol y la prensa deportiva interesada en conocer cómo ha influido el problema del dopaje y el uso de sustancias prohibidas en este deporte desde sus orígenes. Resultados: Actualmente, se realizan pruebas para el control antidopaje a los jugadores aficionados y profesionales de las ligas de este deporte en todo el mundo. Las pruebas, medidas y sanciones que se aplican se ajustan a las prohibiciones y estándares emitidas por la Agencia Mundial Antidopaje y el Código Mundial Antidopaje. Las sustancias utilizadas con mayor frecuencia han sido los esteroides anabólicos, estimulantes, hormona de crecimiento y narcóticos. Conclusiones: una vez concluida la etapa competitiva y con el paso al retiro, muchos beisbolistas se inician en el consumo de tabaco, alcohol y otras drogas que afectan de manera significativa su salud y calidad de vida.

SÍNTESE Introdução: O beisebol tem estado constantemente sob a ameaça do doping, e agora há algumas opiniões de especialistas sugerindo a possibilidade de que muitos sucessos alcançados por jogadores famosos de beisebol que hoje aparecem como as maiores estrelas do esporte podem ter sido relacionados ao uso de substâncias proibidas. Objetivo: O objetivo deste estudo foi explorar os dados publicados na literatura mundial especializada que revelam como o doping, assim como outras formas de fraude, afetaram o beisebol tanto no nível sênior quanto no júnior. Materiais e métodos: Esta revisão de literatura foi realizada por sugestão dos fãs de beisebol e da imprensa esportiva interessada em descobrir como o problema do doping e do uso de substâncias proibidas tem afetado este esporte desde suas origens. Resultados: Atualmente, jogadores amadores e profissionais das ligas de beisebol em todo o mundo são testados para o controle do doping. Os testes, medidas e sanções aplicadas estão de acordo com as proibições e normas emitidas pela Agência Mundial Antidoping e o Código Mundial Antidoping. As substâncias mais utilizadas têm sido esteróides anabolizantes, estimulantes, hormônios de crescimento e narcóticos. Conclusões: uma vez terminada a fase competitiva e com a transição para a aposentadoria, muitos jogadores de beisebol começam a usar tabaco, álcool e outras drogas que afetam significativamente sua saúde e qualidade de vida.

ABSTRACT Introduction: baseball has been constantly under the threat of doping, and currently there are criteria issued by some experts that suggest the possibility that many successes achieved by famous baseball players who nowadays appear as the main big stars of this sport in the ballroom fame, have been related to the consumption of prohibited substances. Objective: the objective of this study was to explore the data published in the specialized world bibliography that reveal how doping, as well as other forms of fraud, have affected baseball in both the major and minor categories. Materials and methods: this bibliographic review work is carried out as a suggestion from baseball fans and the sports press interested in knowing how the problem of doping and the use of prohibited substances has influenced this sport since its origins. Results: Currently, doping control tests are carried out on amateur and professional players in the sport's leagues around the world. The tests, measures and sanctions that are applied conform to the prohibitions and standards issued by the World Anti-Doping Agency and the World Anti-Doping Code. The substances used most frequently have been anabolic steroids, stimulants, Growth Hormone and narcotics. Conclusions: once the competitive stage is over and with the passage to retirement, many baseball players begin to consume tobacco, alcohol and other drugs that significantly affect their health and quality of life.

Theoretical approaches to the engagement with patients in case-management programmes and assertive outreach teams: A systematic review of the literature.

WHAT IS KNOWN ON THE SUBJECT?: It is generally accepted that all interventions carried out by mental health nurses involve engagement with the patient; this engagement is a process that is gradually constructed and is not immediate. In Spain during last decade, nurses working in assertive outreach teams have gradually replaced the traditional institutional setting in favour of environments that are more familiar to the patient. In contrast, when patients and nurses interact outside institutional settings, a new approach and skillset is required in order to adapt to the new environment. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE?: We have systematically identified and assessed the available evidence on how nurses work in assertive outreach team programmes. The therapeutic link is not just assistance; it is actually a construct, which is established between nurse and patient, with the aim of favouring, fostering and strengthening the therapeutic relationship. Only a few studies have discussed the nurse-patient therapeutic link in assertive outreach services. However, it seems important that nurses use a standardized language, that is, a language promoted as a model of correct use and used for functions of greater prestige, especially in public administration and teaching, to integrate it into the theoretical framework. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: With the synthesis that we present, we hope that it promote a more consistent use of the engagement concept in research on this topic. In turn, this will enhance staff support and training and will foster evidence-based practice. The conceptualization of nursing language and its use by professionals helps to improve practice and the lack of a theoretical framework with a nurse perspective. It is necessary to establish a consensus between mental health nurses around the engagement' meaning in the programmes of assertive outreach teams. ABSTRACT: Introduction During last decade in Spain, nurses working in assertive outreach programmes have replaced the traditional institutional setting in favour of the patient's own environment. Engagement with patients requires a different skillset when the axis of the nurse-patient interaction is the patient's own environment. The engagement alone could be associated with the innate concept of patient's care and the helping relationship. However, in the individualized care models, the engagement seems to be an instrument with its own characteristics for the purpose of providing mental health care. Aim/Question To systematically identify and assess the empirical evidence on the relationships and engagement between patients with mental illness (schizophrenia, psychotic disorders, schizoaffective disorders, mood disorders and disorders of adult personality) and nursing mental health nurses. Method Systematic literature review based on PRISMA guidance. Results We identified and reviewed seven primary research studies. Following the analytic processes, three themes emerged: existence of different engagement levels, training needs and skills in the creation and consolidation of the engagement, and engagement as process. Discussion The engagement of nurse and patient is understood as a process that incorporates different stages. Whilst it is established, the engagement is subject to positive and negative influences. For the creation of the engagement and its maintenance specialized skills, knowledge and personal attributes (resilience, psychosocial skills, compressive knowledge of mental health illnesses, capacity to build effective relationships, adaptability and problem-solving) are necessary, but the main focus is on context where it develops, selected by the patient himself, for example, his home. Implications for Practice Administrators may have questions about appropriate hiring practices for assertive outreach teams since certain skills are necessary to obtain un engagement process, and staff training should be considered a key issue to provide specific skills for enhancing engagement and the therapeutic relationship. Conclusion The engagement must be understood as a long-term process. For the creation of the engagement and its maintenance, specialized skills, knowledge and personal attributes are necessary.

Smartphone-based corneal topography with null-screens.

To measure the shape of the fast corneal surface of the human eye, we propose the design and characterization of a compact corneal topographer using the capabilities of a smartphone. The performance evaluation of the compact corneal topographer includes the calculation and compensation of the distortion introduced by the smartphone lens used to acquire the images and the evaluation of a reference surface. To demonstrate the feasibility of our proposal, we performed surface topography measurements on some human corneas and compared the results with those obtained by a commercial corneal topographer. We showed that the results obtained with our algorithms were consistent with other methods that analyze the corneal surface.

Testing the surface quality of a reflective parabolic trough solar collector with two flat null-screens.

In this work, we present a technique for quantitatively assessing the optical quality of a parabolic trough solar collector. The presented method is an adaptation of the null-screen technology, a collection of processes that retrieve information from the reflection of a known object from the surface and then use that information to reconstruct the surface's normal vectors. Via numerical simulations, it is shown that the precision attainable by this method is up to 0.068 mrad, depending on the source of systematical error. In this study we only consider displacements of the physical null-screen as sources of error.

Analytic conic constants to reduce the spherical aberration of a single lens used in collimated light.

We study the formation of caustic surfaces produced by conic lenses, considering a plane wavefront propagating parallel to the optical axis. The shape of the caustic can be modified by changing the parameters of the lens in such a way that if we are able to vanish the caustic, the optical system produces the sharpest diffraction-limited images. Alternatively, caustic surfaces with a large area can be applied to the design of non-imaging optical systems, with potential applications such as diffusers of light for illumination or solar concentrators. Here, we provide analytic equations for the conic constants, principal surfaces, and caustic surfaces, and also approximations at the third and fifth orders formed by conic lenses, in order to reduce the spherical aberration at these orders.

Surface shape evaluation with a corneal topographer based on a conical null-screen with a novel radial point distribution.

In order to measure the shape of fast convex aspherics, such as the corneal surface of the human eye, we propose the design of a conical null-screen with a radial point distribution (spots similar to ellipses) drawn on it in such a way that its image, which is formed by reflection on the test surface, becomes an exact array of circular spots if the surface is perfect. Any departure from this geometry is indicative of defects on the evaluated surface. We present the target array design and the surface evaluation algorithm. The precision of the test is increased by performing an iterative process to calculate the surface normals, reducing the numerical errors during the integration. We show the applicability of the null-screen based topographer by testing a spherical calibration surface of 7.8 mm radius of curvature and 11 mm in diameter. Here we obtain an rms difference in sagitta between the evaluated surface and the best-fitting sphere less than 1 µm.

Improving fast aspheric convex surface tests with dynamic null screens using LCDs.

A method for testing fast aspheric convex surfaces with dynamic null screens using LCDs is shown. A flat null screen is designed and displayed on an LCD monitor with drop-shaped spots in such a way that the image, which is formed by reflection on the test surface, becomes an exactly square array of circular spots if the surface is perfect. Any departure from this geometry is indicative of defects on the surface. Here the whole surface is tested at once. The position of the spots on the LCD can be changed in a dynamic way, to perform point-shifting of the image spots. The proposed procedure improves the dynamic point-shifting method. As has been shown previously, this process reduces the numerical error during the integration procedure, thereby improving the sensitivity of the test. The positioning accuracy for the screen spots is related to the LCD's spatial resolution. Results of the evaluation of a parabolic convex surface with f/#=0.22 are shown.

Quantitative evaluation of an off-axis parabolic mirror by using a tilted null screen.

We report the testing of a fast off-axis surface based on the null screen principles. Here we design a tilted null screen with drop shaped spots drawn on it in such a way that its image, which is formed by reflection on the test surface, becomes an exact square array of circular spots if the surface is perfect. Any departure from this geometry is indicative of defects on the surface. Here the whole surface is tested at once. The test surface has a radius of curvature of r = 20.4 mm (F/0.206). The surface departures from the best surface fit are shown; in addition, we show that the errors in the surface shape are below 0.4 mum when the errors in the determination of the coordinates of the centroids of the reflected images are less than 1 pixel, and the errors in the coordinates of the spots of the null screen are less than 0.5 mm.

Threshold algorithm to recover the deformation of optical surfaces.

The global optimization threshold algorithm is reported to obtain the deformations of an optical surface. The advantage of these types of algorithm is that they can be solved for the correlation problem presented in Seidel polynomials. We obtain the 2D deformations of a surface test with the transversal aberration along one direction only. In order to apply this algorithm we used exact ray tracing to simulate the transversal aberration adapting the same mathematical theory for the Ronchi test. The error obtained in sagitta recovering deformation was 1 microm.

Determinación del perfil hormonal en hombres infectados con el virus del síndrome de la inmunodeficiencia adquirida (SIDA) / Determination of the hormonal profile in AIDS-infected men

Se realizó un estudio descriptivo transversal del perfil hormonal en hombres infectados con el virus de la inmunodeficiencia adquirida. Se incluyeron 34 sujetos divididos en 2 grupos: El grupo I, compuesto por 14 hombres sanos, VIH-negativos, con edad de 25,4 ± 2,3 años, índice de masa corporal (IMC) de 24,0 ± 1,8 kg/m2 y recuento de linfocitos CD4+ de 689 ± 208 ´ 106 cél/L. El II, compuesto por 20 hombres infectados con VIH de reciente diagnóstico y que no estaban sometidos a ningún tratamiento antirretroviral, con edad de 26,9 ± 6,3 años, IMC de 22,1±2,81 kg/m2 y recuento de células CD4+ de 104 ± 112 ´ 106 cél/L. Se determinaron las concentraciones plasmáticas de FSH, LH, prolactina, cortisol, testosterona, T3, T4 y TSH. Se establecieron las correlaciones entre las concentraciones de testosterona y prolactina y los recuentos de células CD4+ y entre las concentraciones de FSH y LH contra las concentraciones de testosterona. Las concentraciones de T3, T4, TSH, cortisol y prolactina no mostraron diferencias estadísticamente significativas cuando se compararon con las determinaciones en las muestras plasmáticas de los sujetos sanos. Se hallaron concentraciones de FSH y de LH superiores (p £ 0,05) para el grupo de hombres infectados con VIH, mientras que las de testosterona estuvieron significativamente disminuidas (p £ 0,05). Para el grupo de pacientes infectados por VIH, la correlación entre las concentraciones de testosterona y los recuentos de células CD4+ fue de y = 0,104 en una función de pendiente negativa, mientras que para el grupo de sujetos sanos el valor fue de p = 0,145, pero con una función dependiente positiva. Las correlaciones entre las concentraciones de prolactina contra las de testosterona y los recuentos de células CD4+, fueron muy similares. Se comprobó que el hipogonadismo en los pacientes afectados por VIH está relacionado con un aumento significativo en las concentraciones de FSH y LH, mientras que otras hormonas hipofisarias, gonadales y de origen adrenal no sufren cambios significativos. Es posible que la disminución en el IMC de estos pacientes sea producida, al menos en parte, por una disminución en la síntesis o secreción de testosterona lo cual sugiere que el tratamiento de estos pacientes con testosterona podría ser un factor de importancia para mejorar la calidad de vida de este grupo(AU)

A descriptive cross-sectional study of the hormonal profile in AIDS-infected men was conducted,. 34 individuals entered the study and were dividided into 2 groups: group 1 composed of 14 sound HIV-negative men aged 25.4 ± 2.3, body mass index (BMI) of 24.0 ± l.8 kg/m2 and CD4+ lymphocyte count of 689 ± 208 x 106 cel/L; and group II consisted of 20 HIV-infected men aged 26.9 ± 6.3 , BMI of 22.1 ± 2.81 kg/m2 and CD4+ cell count of 104 ± 112 x 106 cel/L. They were recently diagnosed and had no antiretroviral treatment. The plasmatic concentrations of FSH, LH, prolactin, cortisol, testosterone, T3, T4 and TSH were determined. Correlations were established between the concentrations of testosterone and prolactin and the CD4+ cell count, and between the concentrations of FSH and LH and the concentrations of testosterone. The concentrations of T3, T4, TSH, cortisol and prolactin showed no statistically significant differences in the plasmatic samples of the sound subjects. Higher concentrations of FSH and LH (p £ 0.05) were found in the group of HIV-infected men, whereas the concentrations of testosterone were significantly reduced (p £ 0.05). In the group of HIV-infected patients, the correlation between the concentrations of testosterone and CD4+ cell count was y = 0.104 in a negative slope function. In the group of sound subjects, the value was p = 0.145, but with a positive slope function. The correlations between the concentrations of prolactin and those of testosterone and the CD4+ cell count were very similar. It was demonstrated that hypogonadism in HIV-infected patients is related to a significant increase in the concentrations of FSH and LH; however, other hypophyseal, gonodal, and of adrenal origin hormones do not experience significant changes. It is possible that the decrease in the BMI of these patients be produced at least in part by a a reduction in the synthesis or secretion of testosterone, which suggests that the treament with testosterone may be an important factor to improve the quality of life of this group(AU)

Characterisation of cement pastes by inverse gas chromatography.

Two cement pastes, commonly used in concrete formulations, were characterised by IGC at 35-80 degrees C before and after coating with an epoxy resin and a hardener. The cements are mixtures of hydrates in various proportions, such as calcium silicate hydrate (CaO-SiO2-H2O) and calcium hydroxide Ca(OH)2. Apolar and polar probes were used to determine the dispersive and acid-base characteristics of the cement pastes. These materials have high surface energy as judged from the dispersive contribution to the surface free energy (gamma(s)d) values lying in the 50-70 mJ/m2 range at 60-80 degrees C. Examination of the specific interactions permitted to show that the cement pastes are strongly amphoteric species with a substantial predominant Lewis basicity that is in line with the basic pH of their aqueous suspensions. Following coating with an epoxy resin (DGEBA) and a hardener (triethylene tetramine), the surface energy of the cements decreases substantially with the mass loading of the organic material. The surface thermodynamic properties were also correlated with the surface chemical composition as determined by X-ray photoelectron spectroscopy.

Concentraciones de leptina y prolactina bioactiva e inmunorreactiva durante el ciclo menstrual normal / Concentrations of lectin and bioactive and immunoreactive prolactine during the normal menstrual cycle

Se determinaron las concentraciones de leptina durante el ciclo menstrual normal de un grupo (n=19) de mujeres fértiles y las concentraciones diarias de estradiol, HL y HFS. Se precisó la actividad inmunológica de la prolactina por radioinmunoensayo (RIA) y la actividad biológica (BIO), por un bioensayo de proliferación de las células Nb2 de linfoma de rata. Se establecieron las relaciones RIA/BIO para la prolactina. Se encontró un aumento de las concentraciones de prolactina (RIA) coincidente con el pico ovulatorio de HL. Se concluyó que las concentraciones de prolactina bioactiva (BIO) fueron significativamente superiores (p < 0,05) durante las fases periovulatoria y lútea. La correlación RIA/BIO para la prolactina osciló entre 0,8 y 2,8. Las concentraciones de leptina mostraron una gran variabilidad entre los ciclos, pero aumentaron durante la fase lútea temprana de ciclo menstrual, aunque no fueron estadísticamente significativas(AU)

The concentrations of leptins during the normal menstrual cycle of a group (n=19) of fertile women and the daily concentrations of estradiol, HL and HFS were determined. The immunological activity of prolactin was determined by radioimmunoassay (RIA), whereas the biological activity (BIO) was determined by a proliferation bioassay of Nb2 cells from rat lymphoma. The RIA/BIO relations for prolactin were established. It was found an increase of the concentrations of prolactin (RIA) coinciding with the HL ovulatory peak. It was concluded that the concentrations of bioactive prolactin (BIO) were significantly higher (p<0.05) during the periovulatory and luteal phases. The RIA/BIO correlation for prolactine oscillated between 0.8 and 2.8. The concentrations of leptine showed a great variability between cycles, but they increased during the early luteal phase of the menstrual cycle, although they were not statistically significant(AU)

Caracterización bioquímica de prolactina de diferentes especies / Biochemical characterization of prolactin of different species

Se utilizaron diferentes técnicas para determinar las características bioquímicas de las preparaciones de prolactina (Prl) de origen hipofisario con preparados que se utilizan en centros de investigaciones para el desarrollo de sistemas in vivo e in vitro, bioanálisis, radioinmunoanálisis y análisis inmunoenzimáticos. Los preparados se analizaron por electroforesis bajo condiciones reductoras (SDS-PAGE), electrotransferencia e inmunodetección, enfoque isoeléctrico, cromatografía líquida de alta presión (HPLC), y capacidad de unión a receptores microsomales (RRA). Se encontró que en las Prl (s) porcina (pPrl), ovina (oPrl) y humana (hPrl) existen proporciones significativas de la forma glucosilada (30-40 porciento), no así en la Prl bovina (bPrl) y en la de rata (rPrl). Se comprobó que es posible detectar impurezas o mezclas de las diferentes formas moleculares de la Prl presentes en estos preparados hipofisarios utilizando HPLC. El análisis por enfoque isoeléctrico de las Prl (s) hipofisarias de diferentes especies reveló que en la bPrl existen 4 isoformas de carga eléctrica, la oPrl y la hPrl están compuestas por 3 isoformas mientras que la rPrl y la pPrl presentan 1 y 2 isoformas, respectivamente. Aún se desconoce cuál podría ser el significado fisiológico de las isoformas de carga eléctrica en la Prl hipofisaria de diferentes especies. Según los resultados obtenidos a partir de las curvas de desplazamiento y de las gráficas de Scatchard, se encontró que existen diferencias entre las constantes de disociación (Kd) y la capacidad de unión de las prolactinas a los receptores microsomales. Finalmente es necesario conocer con mayor exactitud las propiedades bioquímicas, inmunológicas y biológicas de los preparados de las prolactinas que son utilizadas en diferentes estudios tanto in vivo como in vitro, porque en esas residen las funciones biológicas de la hormona. Se confirmó y se amplió la heterogeneidad estructural de la Prl en diferentes especies de mamíferos, que dan lugar a la existencia de diferentes variantes moleculares de la hormona y a la diversidad de funciones que ejerce. Se comprobó la necesidad de desarrollar nuevos métodos para el estudio del significado biológico de la heterogeneidad estructural de la Prl y de obtener las diferentes variantes moleculares de la Prl con un alto grado de pureza, que permitan establecer nuevos métodos cuantitativos, útiles para ser aplicados en estudios clínicos y bioquímicos(AU)

Different techniques were used to determine the biochemical characteristics of the Prolactin (Prl) preparations of hypophyseal origin with preparations that are used in research centers for the development of in vitro and in vivo systems, bioanalyses, radioimmunoanalyses and immunoenzimatic analyses. The preparations were analyzed by electrophoresis under reducing conditions (SDS-PAGE), electrotrasnference and immunodetection, isoelectric focussing, high pressure liquid chromatography (HPLC) and binding capacity to microsomal receptors (RRA). It was observed that in the porcine Prl (pPrl), ovine Prl (oPrl) and human Prl (hPrl) there are significant proportions of the glycosilated form (30-40%) that are not found in the bovine Prl (bPrl) and in the rat Prl (rPrl). It was proved that it is possible to detect impurities or mixtures of the different molecular forms of Prl that appear in these hypophyseal preparations by using HPLC. The analysis by isoelectric focussing of the hypophyseal prolactins of different species revealed that in the bPrl there are 4 isoforms of electric charge, that the oPrl and the hPrl are composed of 3 isoforms, whereas the rPrl and the pPrl have 1 and 2 isoforms, respectively. The physiological meaning of the isoforms of electric charge in the hypophyseal Prl of different species is still unknown. According to the results obtained from the displacement curves and from the Scatchard graphs, it was found that there are differences among the dissociation constants (Kd) and the binding capacity of prolactins to microsomal receptors. Finally, it is necessary to know with more precision the biochemical, immunological and biological properties of the preparations of prolactins that are used in different studies, both in vivo and in vitro, since that's where the biological functions of the hormone are. The structural heterogeneity of the Prl was confirmed and widened in different species of mammals giving rise to the existence of different molecular variants of the hormone and to the diversity of functions it performs. The need to develop new methods for studying the biological meaning of the structural heterogeneity of Prl and to obtain different molecular variants of Prl with a degree of purity that allow to establish new quantitative methods useful to be applied in clinical and biochemical studies was proved. The adequate understanding of the structural modifications of prolactins and of their biological consequences will make possible to establish the synthesis and secretion mechanisms of this hormone, including its multifunctional properties(AU)

Actividad biológica de la prolactina en pacientes con galactorrea y anovulación / Biological activity of prolactin in patients with galactorrhoea and anovulation

Uno de los efectos más documentados para la prolactina es su actividad lactótrofa y sobre el desarrollo mamario en mamíferos. Existen numerosos casos de pacientes normoprolactinémicas que cursan con galactorrea, en las cuales se desconoce el mecanismo responsable de este signo clínico, postulándose la posible existencia de formas hiperactivas de la hormona. En el presente trabajo se estudió la actividad biológica de la prolactina en pacientes normoprolactinémicas e hiperprolactinémicas con galactorrea y/o anovulación asociada, midiendo la actividad mitogénica de la hormona en un bioensayo de células Nb2 en cultivo, a un grupo de muestras de suero obtenidas en el Laboratorio de Reproducción Asistencial del Instituto Nacional de Endocrinología a las cuales previamente se les determinó el nivel de prolactina sérica inmunorreactiva mediante radioinmunoanálisis; se realizó además un ensayo de inhibición de la actividad biológica de la hormona en presencia de anticuerpos antiprolactina, para medir hasta qué punto la actividad mitogénica detectada se debía a la prolactina presente en las muestras. Los resultados obtenidos demuestran que la galactorrea es independiente de los niveles séricos de prolactina inmunorreactiva, no se demostró la existencia de formas hiperactivas responsables de este signo clínico en los diferentes grupos de pacientes normoprolactinémicas y se corroboró el papel biológico de la hormona en el fallo ovárico que tiene lugar en las pacientes hiperprolactinémicas(AU)

Aislamiento y caracterizacion de proteinas unidas a prolactina en el plasma de pacientes hiperprolactinemicos / Isolation and characterization of prolactin-binding proteins in plasma of hyperprolactinemic patients

Se analizaron los resultados de la purificación y caracterización de las proteínas que se encuentran unidas a la PRL en el plasma de pacientes hiperprolactinémicos. Se demostró la existencia del complejo proteico mediante incubación del plasma con PRL marcada con yodo radiactivo (PRL-I125), seguido por separación cromatográfica de gel filtración en Sephacryl S-300HR. Se comparó el patrón de elución con proteínas de pesos moleculares conocidos y la radiactividad incorporada se determinó por conteo de las radiaciones gamma. El complejo prolactina-proteína eluyó en un rango de pesos moleculares elevados. Se aislaron las proteínas unidas a la prolactina por cromatografía de afinidad en una columna de prolactina ovina (oPRL) unida a Sepharosa 4B activada con bromuro de cianógeno. La concentración de proteínas en 5 lotes analizados en forma sucesiva, fue de 180"74Fg/fraccionamiento. Las proteínas aisladas mostraron homología inmunológica con la IgG humana mediante el análisis por inmunodifusión radial en geles de agarosa. Según el patrón electroforético encontrado, las proteínas que se unen a la PRL en el plasma están formadas por 4 bandas de pesos moleculares, 2 de las cuales coinciden con las cadenas ligeras y pesadas de la IgG, mientras que las otras 2 presentan pesos moleculares aproximados de 68 y 80 kDa, respectivamente. Los resultados encontrados permiten identificar a las proteínas unida a la PRL como un complejo con una estructura molecular en la cual participa la IgG

Formas glicosiladas y no glicosiladas de la prolactina porcina sobre la esteroidogénesis ovárica in vitro / Glycosylated and nonglycosylated forms of porcine prolactin on the ovarian in-vitro steroidogenesis

Se investigaron los efectos de la prolactina porcina glicosilada (gpPrl) y la no glicosilada (ngpPrl) aislada y junto a la gonadotropina coriónica humana (HCG) en la acumulación de progesterona (P) y estradiol (E2). Se obtuvieron células de granulosa a partir de folículos preovulatorios de ratas inmaduras tratadas con gonadotropina obtenida de suero de yegua preñada (PMSG). Cuando se adicionaron concentraciones de 1, 10 y 100 ng/mL de gpPrl o ngPrl a cultivos celulares no estimulados con HCG aumentó la acumulación de P a las 72 h de incubación, aunque la gpPrl mostró un efecto estimulatorio más marcado. La acumulación de E2 se incrementó con la administración de concentraciones de 1 y 10 ng/mL de gpPrl junto con 0,1 UI/mL de HCG, la concentración de 100 ng/mL no mostró un efecto estimulatorio significativo. Los resultados obtenidos sugieren que la producción de P y E2 por células de granulosa de rata en cultivo depende de la forma de Prl usada en los experimentos así como de la presencia de HCG como agente estimulatorio de la esteroidogénesis en el medio de cultivo

Caracterización de sitios receptores para prolactina en hígados de ratas embarazadas I: optimización del ensayo de radiorreceptores / Characterization of prolactin receptors in pregnant rat livers: making optimum the radioreceptor assay

Se caracterizaron sitios receptores específicos para Prl presentes en la fracción microsomal de hígados de ratas embarazadas. La unión específica máxima del radiorreceptor fue de 23,18 ñ 5,70% (n = 5 preparaciones microsomales diferentes). La pendiente de la curva de desplazamiento linealizada fue de m = -0,91 ñ 0,10, y el desplazamiento semimáximo, ED50, de 55,51 ñ 13,83 ng/mL. Análisis Scatchard revelaron la existencia de un único tipo de sitios de unión, con una constante de equilibrio, K* = 7,07 ñ 3,4 x 108 L/moles. El número de sitios de unión para oPrl fue de N = 6,17 ñ 2,68 x 10-8 moles/L

Efecto de diferentes fracciones del líquido folicular sobre la esteroidogenesis y proliferación de las células de granulosa in vitro / Effect of different fractions of follicular fluid on the steroidogenesis and proliferation of granulosa cells in vitro

Se determinó el de las fracciones obtenidas por cromatografía en cromatografía en SEPHACRYL S-300 del líquido de foliculo ováricos bovinos, en diferentes estadios de desarrollo, sobre la esteroidogénesis y proliferación de células de granulosa de la misma especie, pero en etapas muy tempranas de desarrollo independientemente del estadio de maduración, el líquido folicular está constituído por cuatro grupos de proteínas de diferentes pesos moleculares. En la fracción 1 se encontró un efecto inhibitorio significativo (p<0,05) sobre la síntesis de progesterona. El efecto de las diferentes fracciones sobre la esteroidogénesis varía tanto en relación con el estadio de maduración como con el tiempo de cultivo. No se encontró un efecto marcadamente significativo de las fracciones sobre la proliferación celular

Proteínas del líquido folicular bovino / Proteins of bovine follicular fluid

En este estudio se han tratado de determinar proteínas marcadoras de la maduración folicular, partiendo del fraccionamiento en ultragel ACA 34 del líquido de folículos ováricos bovinos de diferentes estadios de desarrollo, y electroforésis en gel de poliacrilamina de las fracciones proteicas aisladas