Five-year results of atropine 0.01% efficacy in the myopia control in a European population.

AIMS: To evaluate the efficacy and safety of 0.01% atropine eye-drops in controlling myopia progression over 5 years. METHODS: Experimental, analytical, prospective, randomised and longitudinal study, in 361 right eyes from 361 children randomised into the control group (177 eyes without treatment) and treatment group (184 eyes with 0.01% atropine eye-drops). Children assigned to the treatment group used 0.01% atropine once a day every night and the control group's children did not use any treatment or placebo. All the subjects completed an eye examination every 6 months for the 5 years of follow-up. The examination included subjective and objective refraction with cycloplegia, axial length (AL), keratometry and anterior chamber depth (ACD) to evaluate the efficacy of the treatment. It also included the anterior and posterior pole examination to evaluate the safety of the treatment. RESULTS: The SE increased -0.63±0.42D in children after 5 years of treatment with 0.01% atropine, while in the control group the increase was -0.92±0.56D. AL increased 0.26±0.28 mm in the treatment group compared with 0.49±0.34 mm in the control group. Atropine 0.01% showed an efficacy of 31.5% and 46.9% in the control of the SE and AL increase, respectively. ACD and keratometry did not have significant changes between groups. CONCLUSIONS: Atropine 0.01% is effective in slowing myopia progression in a European population. There were no side effects after 5 years of 0.01% atropine.

Hyperchaos, Intermittency, Noise and Disorder in Modified Semiconductor Superlattices.

Weakly coupled semiconductor superlattices under DC voltage bias are nonlinear systems with many degrees of freedom whose nonlinearity is due to sequential tunneling of electrons. They may exhibit spontaneous chaos at room temperature and act as fast physical random number generator devices. Here we present a general sequential transport model with different voltage drops at quantum wells and barriers that includes noise and fluctuations due to the superlattice epitaxial growth. Excitability and oscillations of the current in superlattices with identical periods are due to nucleation and motion of charge dipole waves that form at the emitter contact when the current drops below a critical value. Insertion of wider wells increases superlattice excitability by allowing wave nucleation at the modified wells and more complex dynamics. Then hyperchaos and different types of intermittent chaos are possible on extended DC voltage ranges. Intrinsic shot and thermal noises and external noises produce minor effects on chaotic attractors. However, random disorder due to growth fluctuations may suppress any regular or chaotic current oscillations. Numerical simulations show that more than 70% of samples remain chaotic when the standard deviation of their fluctuations due to epitaxial growth is below 0.024 nm (10% of a single monolayer) whereas for 0.015 nm disorder suppresses chaos.

Factors associated to the market value of professional soccer players / Factores asociados al valor de mercado de los futbolistas profesionales / Fatores associados ao valor de mercado de jogadores profissionais de futebol

The objective of this study was analysed to the market value (MV) of professional soccer players from Top-5 European Soccer Leagues. An ANOVA analysed the effect of the independent variables on the MV of the soccer players, with p<0.01. Soccer players from the Premier League (PL) showed greater MV compared to other leagues. Foreign soccer players showed greater MV compared to national soccer players. Soccer players between 21-30 years showed greater MV compared to those <21 and >30 years. Forward and midfielders showed greater MV compared to goalkeepers and backs. Soccer players that represented their countries at international matches showed greater MV compared to those that did not. The soccer players with a youth background formation in their clubs in the Premier League and La Liga showed greater MV compared to soccer players coming from other clubs. In conclusion, extrinsic factors affect the MV of soccer players. Research results may be useful to the sport managers in the selection of professional soccer players. (AU)

El objetivo de este estudio fue analizar el valor de mercado (VM) de futbolistas profesionales de las 5 mejores ligas europeas de fútbol. Se analizó el efecto de las variables independientes sobre el VM de los futbolistas, mediante una ANOVA con un nivel de significación de p <0.01. Los futbolistas de la Premier League (PL) mostraron mayor VM en comparación con los de otras ligas. Los futbolistas extranjeros mostraron mayor VM en comparación con los futbolistas nacionales. Los futbolistas entre 21-30 años mostraron mayor VM en comparación con los <21 y > 30 años. Los delanteros y centrocampistas, mostraron mayor VM en comparación con los porteros y los laterales. Los futbolistas que representaron a sus países en partidos internacionales mostraron mayor VM en comparación con los que no lo hicieron. Los futbolistas de formación juvenil en clubes de la PL y La Liga (LL) mostraron mayor VM en comparación con los futbolistas de otros clubes. En conclusión, factores intrínsecos y extrínsecos afectan el VM de los futbolistas. Los resultados de esta investigación pueden ser útiles para los directores deportivos en el proceso de selección de futbolistas profesionales. (AU)

O objetivo deste estudo foi analisar o valor de mercado (VM) de jogadores de futebol profissional das 5 melhores ligas europeias de futebol. O efeito das variáveis independentes sobre a VM dos futebolistas foi analisado por meio de uma ANOVA com nível de significância de p <0,01. Os jogadores de futebol da Premier League (PL) apresentaram MV mais alto em comparação com os de outras ligas. Os jogadores de futebol estrangeiros apresentaram VM superior em comparação aos jogadores de futebol nacionais. Jogadores de futebol entre 21-30 anos apresentaram maior VM em comparação com aqueles com <21 e> 30 anos. Os atacantes e meio-campistas mostraram maior VM em relação aos goleiros e laterais. Os jogadores de futebol que representaram seus países em jogos internacionais apresentaram maior MV em comparação com aqueles que não o fizeram. Jogadores de futebol em formação de jovens em clubes da PL e La Liga (LL) apresentaram maior VM em comparação com jogadores de futebol de outros clubes. Em conclusão, fatores intrínsecos e extrínsecos afetam a VM dos jogadores de futebol. Os resultados desta pesquisa podem ser úteis para dirigentes esportivos no processo de seleção de jogadores profissionais de futebol. (AU)

Utility of an additional photodynamic therapy session after multiple failed PDT treatments in chronic central serous chorioretinopathy.

PURPOSE: To assess the efficacy of an additional photodynamic therapy (PDT) in chronic central serous chorioretinopathy (cCSCR) patients who have two or more previous failed PDTs. METHODS: Ten eyes of 10 patients with cCSCR who had received two or more PDTs without complete resolution of the subretinal fluid (SRF) or with early recurrence (before 3 months) were included. An additional half-fluence PDT was performed. Swept-source optical coherence tomography (OCT) and OCT angiography were performed before, 3 days, 1 month, 3 months, 6 months and 12 months after treatment. Age, gender, best-corrected visual acuity (BCVA), subfoveal choroidal thickness, SRF and vessel occlusion in the choriocapillaris (CC) were collected. RESULTS: The median number of previous PDTs was 3 (range 2 to 4). BCVA before and 12 months after treatment was 72 letters (50 to 95) and 78 letters (55 to 100) (p=0.094). Median initial SRF was 94 µm (50 to 306), being 0 µm (range 0 to 81) at the end of the follow-up (p=0.007). After the additional PDT, 8 out of 10 patients had a complete SRF resorption. All the patients except one who had a complete response (7/8) had an occlusion in the CC 3 days after PDT. CONCLUSION: Despite previous failed PDTs in cCSCR, good anatomical results can be achieved, this being more likely if an early vessel occlusion in the CC is observed. Even when the BCVA did not improve, the high rate of fluid resolution could justify the additional PDT treatment in order to maintain visual function.

External Loads in Under-12 Players during Soccer-7, Soccer-8, and Soccer-11 Official Matches.

The aim of this study was to compare the external loads (i.e., displacement distances and velocities) of 10-11 years-old soccer players during Soccer-7 (i.e., seven-a-side), Soccer-8 (i.e., eight-a-side), and Soccer-11 (i.e., eleven-a-side) official matches. Male athletes (n = 133; age, 10.9 ± 0.8 years) were measured during official matches for total distance (TD), relative distance (Drel), maximal velocity (Vmax), acceleration (ACC), deceleration (DEC), and absolute and relative distance covered at different velocities. Data during matches were collected using a Global Positioning System unit. Greater TD was recorded during Soccer-11 compared to Soccer-7 and Soccer-8 (p < 0.01), and greater Drel during Soccer-11 compared to Soccer-8 (p < 0.05). Absolute ACC was greater during Soccer-11 compared to Soccer-7 (p < 0.01), although relative values for %ACC and %DEC were greater during Soccer-7 and Soccer-8 compared to Soccer-11 (p < 0.01). Globally, results show that Soccer-11 matches induce greater external loads compared to Soccer-7 and Soccer-8 matches. Current results may help coaches and soccer-related organizers to plan more suited soccer competitions for young players, with lower external loads.

Anomalous Angiogenesis in Retina.

Age-related macular degeneration (AMD) may cause severe loss of vision or blindness, particularly in elderly people. Exudative AMD is characterized by the angiogenesis of blood vessels growing from underneath the macula, crossing the blood-retina barrier (which comprises Bruch's membrane (BM) and the retinal pigmentation epithelium (RPE)), leaking blood and fluid into the retina and knocking off photoreceptors. Here, we simulate a computational model of angiogenesis from the choroid blood vessels via a cellular Potts model, as well as BM, RPE cells, drusen deposits and photoreceptors. Our results indicate that improving AMD may require fixing the impaired lateral adhesion between RPE cells and with BM, as well as diminishing Vessel Endothelial Growth Factor (VEGF) and Jagged proteins that affect the Notch signaling pathway. Our numerical simulations suggest that anti-VEGF and anti-Jagged therapies could temporarily halt exudative AMD while addressing impaired cellular adhesion, which could be more effective over a longer time-span.

Measuring Choroid Thickness as a Marker of Systemic Inflammation in Patients With Ankylosing Spondylitis.

BACKGROUND AND OBJECTIVE: Ankylosing spondylitis (AS) is an inflammatory disease, and choroidal thickness (CT) has been proposed and evaluated as a potential marker of systemic inflammation associated with AS and other inflammatory diseases. This study compared CT measurements taken from patients with severe AS disease activity without eye inflammation with those taken from healthy subjects. METHODS: This cross-sectional, multicenter study compared CT in 44 patients with high AS disease activity, and no history of eye inflammation with CT in 44 matched healthy subjects aged between 18 and 65 years. In the AS group, the correlation between CT and C-reactive protein, human leukocyte antigen (HLA) B27 positivity, disease duration, and disease activity was calculated. RESULTS: Mean CT values of patients with AS were significantly higher in the right eye, the left eye, and the thickest choroid eye. The right eye mean CT was 338.3 ± 82.8 µm among patients with AS and 290.5 ± 71.2 µm among healthy subjects (p = 0.005). The left eye mean CT was 339.5 ± 84.7 µm for patients with AS and 298.4 ± 68.9 µm for healthy subjects (P = 0.015). The thickest choroid eye CT was 358.4 ± 82.1 µm among patients with AS and 314.1 ± 65.2 µm among healthy subjects (P = 0.006). We did not find a significant correlation between CT and disease activity, C-reactive protein, human leukocyte antigen B27 positivity, or disease duration. CONCLUSIONS: Patients with active AS but without a history of eye inflammation had a thicker choroid than healthy subjects. This finding suggests that CT is a marker of systemic inflammation in patients with inflammatory disease, regardless of known eye symptoms.

Notch signaling and taxis mechanisms regulate early stage angiogenesis: A mathematical and computational model.

During angiogenesis, new blood vessels sprout and grow from existing ones. This process plays a crucial role in organ development and repair, in wound healing and in numerous pathological processes such as cancer progression or diabetes. Here, we present a mathematical model of early stage angiogenesis that permits exploration of the relative importance of mechanical, chemical and cellular cues. Endothelial cells proliferate and move over an extracellular matrix by following external gradients of Vessel Endothelial Growth Factor, adhesion and stiffness, which are incorporated to a Cellular Potts model with a finite element description of elasticity. The dynamics of Notch signaling involving Delta-4 and Jagged-1 ligands determines tip cell selection and vessel branching. Through their production rates, competing Jagged-Notch and Delta-Notch dynamics determine the influence of lateral inhibition and lateral induction on the selection of cellular phenotypes, branching of blood vessels, anastomosis (fusion of blood vessels) and angiogenesis velocity. Anastomosis may be favored or impeded depending on the mechanical configuration of strain vectors in the ECM near tip cells. Numerical simulations demonstrate that increasing Jagged production results in pathological vasculatures with thinner and more abundant vessels, which can be compensated by augmenting the production of Delta ligands.

Choroidal Thickness Is a Biomarker Associated With Response to Treatment in Ankylosing Spondylitis.

OBJECTIVE: Choroidal thickness (CT) has been evaluated as a marker of systemic inflammation in ankylosing spondylitis (AS). This study evaluates the CT of AS patients before and after 6 months of biological treatment. METHODS: This longitudinal multicenter study evaluated CT in 44 AS patients. The correlations between CT and C-reactive protein (CRP) with disease activity indices were calculated. The concordance between CT and CRP was determined. We assessed factors associated with response to treatment. Clinically important improvement was defined as a decrease in Ankylosing Spondylitis Disease Activity Score of 1.1 points or greater. RESULTS: Forty-four eyes in patients aged 18 to 65 years were included. Mean CT values were significantly higher at baseline than after 6 months of treatment (baseline: 355.28 ± 80.46 µm; 6 months: 341.26 ± 81.06 µm; p < 0.001). There was a 95% concordance between CT and CRP at baseline and 6 months. Clinically important improvement was associated with lower baseline CT and age as independent factors (odds ratios, 0.97 [95% confidence interval, 0.91-0.93; p = 0.009] and 0.81 [95% confidence interval, 0.7-0.95; p = 0.005]), with baseline CT of less than 374 µm (sensitivity 78%, specificity 78%, area under the curve 0.70, likelihood ratio 3.6). CONCLUSIONS: Choroidal thickness decreased significantly after 6 months of biological treatment in all treatment groups. Choroidal thickness and CRP had a 95% concordance. A high CT was associated with a risk of biological treatment failure. Choroidal thickness can be considered a useful biomarker of inflammation and a factor associated with response to treatment in AS.

Coherence Resonance and Stochastic Resonance in an Excitable Semiconductor Superlattice.

Collective electron transport causes a weakly coupled semiconductor superlattice under dc voltage bias to be an excitable system with 2N+2 degrees of freedom: electron densities and fields at N superlattice periods plus the total current and the field at the injector. External noise of sufficient amplitude induces regular current self-oscillations (coherence resonance) in states that are stationary in the absence of noise. Numerical simulations show that these oscillations are due to the repeated nucleation and motion of charge dipole waves that form at the emitter when the current falls below a critical value. At the critical current, the well-to-well tunneling current intersects the contact load line. We have determined the device-dependent critical current for the coherence resonance from experiments and numerical simulations. We have also described through numerical simulations how a coherence resonance triggers a stochastic resonance when its oscillation mode becomes locked to a weak ac external voltage signal. Our results agree with the experimental observations.

Soccer Small-Sided Games Activities Vary According to the Interval Regime and their Order of Presentation within the Session.

In order to investigate the physical demands of widely used in soccer small-sided games (SSGs), we compared game variations performed under different interval (fixed or variable) and timing regimens (beginning or end of a training session). Twelve male players wore GPS devices during the SSGs to record total distance, relative distance, distance at different speeds, and maximum velocity variables. Four variations of SSGs (4x4) were randomly applied: beginning of a training session with fixed and variable recovery, or end of a training session with fixed and variable recovery. During the beginning or end of a training session settings with fixed recovery duration, 2-min of playing and 2-min of recovery were provided. During the beginning and end of a training session settings with variable recovery, athletes kept playing until a goal was scored, or up to 2-min if no goals were scored. Results were analysed using MANOVA. Total distance and relative distance were higher in the beginning compared to end of training sessions for both fixed and variable recovery duration (small to moderate effect sizes). Distance at various speed ranges (i.e., 13-18 km/h and >18 km/h) was higher (p ≤ 0.01) at the beginning than at the end of training sessions with variable recovery. In addition, distance >18 km/h was higher at the beginning of a training session with variable recovery than fixed recovery and at the end of a training session with variable recovery than fixed recovery. In conclusion, several physical demand characteristics are affected by the moment of SSG application, while others respond to the recovery regime during SSGs, thus providing indications to the coaches to prescribe the intended training intensity by manipulating the context.

Specific Changes in Young Soccer Player's Fitness After Traditional Bilateral vs. Unilateral Combined Strength and Plyometric Training.

The aim of this study was to compare changes in young soccer player's fitness after traditional bilateral vs. unilateral combined plyometric and strength training. Male athletes were randomly divided in two groups; both received the same training, including strength training for knee extensors and flexors, in addition to horizontal plyometric training drills. The only difference between groups was the mode of drills technique: unilateral (UG; n = 9; age, 17.3 ± 1.1 years) vs. bilateral (TG; n = 9; age, 17.6 ± 0.5 years). One repetition maximum bilateral strength of knee muscle extensors (1RM_KE) and flexors (1RM_KF), change of direction ability (COD), horizontal and vertical jump ability with one (unilateral) and two (bilateral) legs, and limb symmetry index were measured before and after an 8-week in-season intervention period. Some regular soccer drills were replaced by combination of plyometric and strength training drills. Magnitude-based inference statistics were used for between-group and within-group comparisons. Beneficial effects (p < 0.05) in 1RM_KE, COD, and several test of jumping performance were found in both groups in comparison to pre-test values. The limb symmetry index was not affected in either group. The beneficial changes in 1RM_KE (8.1%; p = 0.074) and 1RM_KF (6.7%; p = 0.004), COD (3.1%; p = 0.149), and bilateral jump performance (from 2.7% [p = 0.535] to 10.5% [p = 0.002]) were possible to most likely beneficial in the TG than in the UG. However, unilateral jump performance measures achieved likely to most likely beneficial changes in the UG compared to the TG (from 4.5% [p = 0.090] to 8.6% [p = 0.018]). The improvements in jumping ability were specific to the type of jump performed, with greater improvements in unilateral jump performance in the UG and bilateral jump performance in the TG. Therefore, bilateral strength and plyometric training should be complemented with unilateral drills, in order to maximize adaptations.

Parameter dependence of high-frequency nonlinear oscillations and intrinsic chaos in short GaAs/(Al, Ga)As superlattices.

We explore the design parameter space of short (5-25 period), n-doped, Ga/(Al,Ga)As semiconductor superlattices (SSLs) in the sequential resonant tunneling regime. We consider SSLs at cool (77 K) and warm (295 K) temperatures, simulating the electronic response to variations in (a) the number of SSL periods, (b) the contact conductivity, and (c) the strength of disorder (aperiodicities). Our analysis shows that the chaotic dynamical phases exist on a number of sub-manifolds of codimension zero within the design parameter space. This result provides an encouraging guide towards the experimental observation of high-frequency intrinsic dynamical chaos in shorter SSLs.

Relation among Aromatase P450 and Tumoral Growth in Human Prolactinomas.

The pituitary gland is part of hypothalamic-pituitary-gonadal axis, which controls development, reproduction, and aging in humans and animals. In addition, the pituitary gland is regulated mainly by hormones and neurotransmitters released from the hypothalamus and by systemic hormones secreted by target glands. Aromatase P450, the enzyme responsible for the catabolization of aromatizable androgens to estrogens, is expressed in different parts of body, including the pituitary gland. Moreover, aromatase P450 is involved in sexual dimorphism where alteration in the level of aromatase can initiate a number of diseases in both genders. On the other hand, the direct actions of estrogens, mainly estradiol, are well known for stimulating prolactin release. Numerous studies have shown that changes in the levels of estrogens, among other factors, have been implicated in the genesis and development of prolactinoma. The pituitary gland can produce estradiol locally in several types of endocrine cells, and it is possible that aromatase could be responsible for the maintenance of the population of lactotroph cells and the modulation of the action of central or peripheral regulators. Aromatase overexpression due to inappropriate gene regulation has clinical effects such as the pathogenesis of prolactinomas. The present study reports on the synthesis of pituitary aromatase, its regulation by gonadal steroids, and the physiological roles of aromatase on pituitary endocrine cells. The involvement of aromatase in the pathogenesis of pituitary tumors, mainly prolactinomas, through the auto-paracrine production of estradiol is reviewed.

Endothelial immunocytochemical expression of pituitary IL-1ß and its relation to ACTH-positive cells is regulated by corticosterone in the male rat.

Interleukin-1 beta (IL-1ß) is a cytokine linking the neuroendocrine system and metabolic homeostasis. We have previously demonstrated the relevance of IL-1ß for maintaining the pituitary ACTH-producing cells by immuno-blocking its effects in pituitary cultures. However, the morphological characteristics and the intimate relationship of the pituitary cells expressing IL-1ß and ACTH remain unknown. For determining pituitary variations of immunoreactivity for IL-1ß and its relation with ACTH-positive cells under stress situations, we performed an immunohistochemical analysis of the expression of IL-1ß and ACTH in the pituitary gland of adult rats, in the absence or presence of corticosterone, by establishing different groups: untreated, sham-operated, and bilaterally adrenalectomized animals. In the rats subjected to surgery, the glucocorticoid was administered on the same day of the intervention and on the third day post-surgery. Interestingly, it was observed that IL-1ß was located in the pituitary endothelial cells at the hypophyseal portal vessels, regardless of the treatment schedule. When comparing the pituitary immunoreactive surface to IL-1ß expression without corticosterone, adrenalectomized animals displayed a significantly greater area than the sham-operated animals. Corticosterone significantly inhibited the effect of adrenalectomy depending on the time interval it was administered. By in situ hybridization, IL-1ß mRNA expression was also correlated with immnunocytochemical expression of pituitary IL-1ß. Our results demonstrate that IL-1ß is a constitutive element in endothelial portal pituitary vessels and under stress experimental conditions IL-1ß increases its expression and its relation with ACTH-positive cells, suggesting that IL-1ß could participate in an autocrine-paracrine fashion thereby modulating the pituitary population of ACTH-positive cells.

Noise-enhanced chaos in a weakly coupled GaAs/(Al,Ga)As superlattice.

Noise-enhanced chaos in a doped, weakly coupled GaAs/Al_{0.45}Ga_{0.55}As superlattice has been observed at room temperature in experiments as well as in the results of the simulation of nonlinear transport based on a discrete tunneling model. When external noise is added, both the measured and simulated current-versus-time traces contain irregularly spaced spikes for particular applied voltages, which separate a regime of periodic current oscillations from a region of no current oscillations at all. In the voltage region without current oscillations, the electric-field profile consist of a low-field domain near the emitter contact separated by a domain wall consisting of a charge accumulation layer from a high-field regime closer to the collector contact. With increasing noise amplitude, spontaneous chaotic current oscillations appear over a wider bias voltage range. For these bias voltages, the domain boundary between the two electric-field domains becomes unstable and very small current or voltage fluctuations can trigger the domain boundary to move toward the collector and induce chaotic current spikes. The experimentally observed features are qualitatively very well reproduced by the simulations. Increased noise can consequently enhance chaotic current oscillations in semiconductor superlattices.

On the mathematical modelling of tumor-induced angiogenesis.

An angiogenic system is taken as an example of extremely complex ones in the field of Life Sciences, from both analytical and computational points of view, due to the strong coupling between the kinetic parameters of the relevant branching - growth - anastomosis stochastic processes of the capillary network, at the microscale, and the family of interacting underlying biochemical fields, at the macroscale. To reduce this complexity, for a conceptual stochastic model we have explored how to take advantage of the system intrinsic multiscale structure: one might describe the stochastic dynamics of the cells at the vessel tip at their natural microscale, whereas the dynamics of the underlying fields is given by a deterministic mean field approximation obtained by an averaging at a suitable mesoscale. But the outcomes of relevant numerical simulations show that the proposed model, in presence of anastomosis, is not self-averaging, so that the ``propagation of chaos" assumption cannot be applied to obtain a deterministic mean field approximation. On the other hand we have shown that ensemble averages over many realizations of the stochastic system may better correspond to a deterministic reaction-diffusion system.

Morphological evidence of the possible relevance of aromatase P450 in autoparacrine regulation and pathology of the hypophysis

Aromatase P450, the enzyme responsible for the catabolism of aromatizable androgens to estrogens is involved in sexual dimorphism and several pathologies induced by estrogenic effects. The present work reports evidence of pituitary aromatase synthesis, its regulation by gonadal steroids, and the physiological roles of aromatase on pituitary endocrine cells. The involvement of aromatase, through the auto-paracrine production of estradiol, in the pathogenesis of pituitary tumors -mainly prolactinomas- is reviewed

No disponible

Local transformations of androgens into estradiol by aromatase P450 is involved in the regulation of prolactin and the proliferation of pituitary prolactin-positive cells.

In previous studies we demonstrated the immunohistochemical expression of aromatase in pituitary cells. In order to determine whether pituitary aromatase is involved in the paracrine regulation of prolactin-producing pituitary cells and the physiological relevance of pituitary aromatase in the control of these cells, an in vivo and in vitro immunocytochemical and morphometric study of prolactin-positive pituitary cells was carried out on the pituitary glands of adult male rats treated with the aromatase antagonist fadrozole. Moreover, we analyzed the expression of mRNA for the enzyme in pituitary cells of male adult rats by in situ hybridization. The aromatase-mRNA was seen to be located in the cytoplasm of 41% of pituitary cells and was well correlated with the immunocytochemical staining. After in vivo treatment with fadrozole, the size (cellular and nuclear areas) of prolactin cells, as well as the percentage of prolactin-positive cells and the percentage of proliferating-prolactin cells, was significantly decreased. Moreover, fadrozole decreased serum prolactin levels. In vitro, treatment with fadrozole plus testosterone induced similar effects on prolactin-positive cells, inhibiting their cellular proliferation. Our results suggest that under physiological conditions aromatase P450 exerts a relevant control over male pituitary prolactin-cells, probably transforming testosterone to estradiol in the pituitary gland.

Estudio de la flexibilidad de luchadores de kickboxing de nivel internacional / Study of the flexibility of international kickboxing wrestlers

El estudio tiene como objetivo evaluar la flexibilidad de la musculatura de tronco y miembros inferiores, en luchadores de kickboxing de diferente nivel competitivo, que no realizan ejercicios de estiramiento de forma habitual. Unos valores óptimos en esta cualidad son necesarios, por su posible relación con la lesión muscular y el rendimiento deportivo. La muestra esta compuesta por 14 luchadores (24,5} 4,9 años de edad, 176,4} 8,2 cm de estatura y 73,8}6,7 kg de peso) de nivel internacional (n=6) y nacional (n=8). Se midieron los arcos de movilidad en la articulación del tronco a través del Test de flexión lateral de tronco, y los test de Schober y test de Ott; en la articulación de la cadera se aplicaron el Test de abducción máxima de cadera en bipedestación con rotación externa unilateral, Test de abducción bilateral máxima de cadera en bipedestación, Test de Abducción de cadera, Test de flexión de cadera en de cubito supino, Test "Back saver sit and reach" y Test "sit and reach"; y en la articulación del tobillo se empleó el test de flexión dorsal y plantar de tobillo. Los resultados muestran unos valores superiores a los encontrados en otras disciplinas deportivas. En el análisis por categorías se han encontrado diferencias significativas entre competidores de nivel internacional y nacional en el test de abducción de cadera (p≤0,05) y en la flexión dorsal (p≤0,01) del tobillo no dominante. No se han observado diferencias entre el miembro dominante y no dominante en ninguno de los grupos estudiados, si bien en los luchadores de nivel internacional se observa un mayor equilibrio entre los valores obtenidos en los test. Los luchadores de nivel internacional participantes en este estudio presentan mejores índices en la musculatura aductora de la cadera. Las técnicas de kickboxing demandan un buen nivel de flexibilidad por parte de los luchadores

The study aims to assess the flexibility of the muscles of the trunk and lower limbs in different fighter’s competitive kickboxing, which do not perform stretching exercises regularly. Optimal values in this quality are required, by their possible relation to muscle injury and athletic performance. The sample consists of 14 fighters (24.5 } 4.9 years old, 176.4 } 8.2 cm in height and 73.8 } 6.7 kg) of international level (n = 6) and national (n = 8). Was analyzed the mobility in the trunk joint through Sideways bending test, and the Schober and Ott test, in the hip joint tests were applied leg sideward Split, Split leg sideways, Hip abduction, Leg raise, Back saver sit and reach and Sit and reach, and the ankle joint goniometry was used for plantar and dorsal flexion of the foot. The results show higher values than those found in other sports. In the category analysis found significant differences between international and national competitors in the Hip abduction test (p ≤ 0.05) and dorsal flexion (p ≤ 0.01) of the non-dominant leg. No differences were observed between the dominant and non-dominant member in any of the groups studied, although international fighters is a greater balance between the values obtained in the test. International fighters participating in this study have better rates in the adductor muscles of the hip