Relación de los estadíos de maduración del ovario y el efecto del BPA a nivel hipofisario en pez cebra (Danio rerio) / Relationship of ovarian maturation stages and the effect of BPA on pituitary level in zebrafish (Danio rerio)

El bisphenol A (BPA), que es utilizado en la fabricación de envases y contenedores de alimentos, puede actuar como disruptor endocrino uniéndose a los receptores estrogénicos. Dado que la hipófisis esencialmente juega su papel en la gametogénesis y esteroidogénesis, el objetivo fue evaluar la acción del BPA sobre la hipófisis y estudiar la posible implicación sobre la maduración folicular mediante estudio histopatológico y morfométrico. Se utilizaron 60 pez cebra (Danio rerio) de 16 semanas, distribuidos al azar en un grupo control y cuatro grupos expuestos a BPA (1, 10, 100 y 1000 μg/L) en el agua durante 14 días). Se cuantificaron los niveles de BPA en peces mediante LC-MS/MS y se realizó el estudio histopatológico de adenohipófisis y ovario. Estructuralmente se reveló un proceso degenerativo de las células gonadotropas de todos los grupos tratados. Ultraestructuralmente, se observó en el grupo control y tratado con 1 μg/L una activación de las células, aumento de gránulos de secreción en el complejo de Golgi, y fundamentalmente, del retículo endoplásmico rugoso, mientras que en el resto de grupos estas células mostraron signos de degeneración. En los grupos tratados con 100 y 1000 μg/L, se observaron células de castración. En ovario pudo determinarse morfométricamente un incremento de atresia folicular a medida que se incrementó la concentración de exposición al BPA. Nuestros resultados indican que el BPA produce una degeneración de células gonadotropas a nivel hipofisario y un aumento de la atresia folicular en las gónadas probablemente debido a una inhibición en la liberación de las gonadotropinas (AU)

Bisphenol-A (BPA) is widely used as part of packaging and food containers, and acts as an endocrine disruptor by binding to estrogen receptors. The importance of the pituitary lies in its role in gametogenesis and gonadal steroidogenesis level. The objective was to evaluate the effects of BPA on the pituitary and its possible relationship with follicular maturation by histopathology. 60 female 16 weeks of age zebrafish were used, randomly divided into a control group and four groups exposed to BPA (1, 10, 100 and 1000 μg/L) in water for 14 days. After the sacrifice, samples were taken to quantify BPA levels in fish using LC-MS/MS, in addition to the histopathological study of the anterior pituitary and the ovary. Structural studies revealed a degenerative process of the gonadotrope cells of the pituitary in all treated groups, being these cells positive to PAS reaction. The ultrastructure presented cell activation in the group treated with 1 μg/L, with increased secretion granules at the Golgi complex, and essentially the rough endoplasmic reticulum, whereas in the other groups, these cells appeared degenerated. In the groups treated with 100 and 1000 μg/L, castration cells were observed with a rough endoplasmic vacuole. Increased ovarian follicular atresia as BPA concentration increased was also determined. The results indicate that BPA produces a degeneration of the gonadotrope cells at pituitary level and an increase of atretic follicles in gonads probably due to an inhibition in the release of the gonadotropins (AU)

Validez de un método fotométrico de medición de partículas en aire para el control de quirófanos y otras salas de ambiente controlado en los hospitales / Validity of a photometric method of counting particles in air for control of operating rooms and clean rooms in hospitals

Objetivo: Validar un sistema de medici¨®n fotom¨¦trica de part¨ªculas en aire para realizar los controles de bioseguridad ambiental de quir¨®fanos y otras salas de ambiente controlado en los hospitales. Material y m¨¦todos: Se realizaron un total de 144 mediciones pareadas de aire, 88 en ocho quir¨®fanos con sistemas de ventilaci¨®n convencional y tres niveles de filtraci¨®n y 56 en nueve habitaciones sin instalaciones de ventilaci¨®n. Se midieron part¨ªculas de entre 0,1 a 10 ¦Ìm en mg/m3 por m¨¦todo fotom¨¦trico. Simult¨¢neamente, en cada sala se realiz¨® impacto de aire en placas de Petri con medio de cultivo mediante aparato aspirador de cabezal perforado, obteniendo tras cinco d¨ªas de incubaci¨®n recuento de unidades formadoras de colonias (UFC)/1000L. Finalmente se realiz¨® el c¨¢lculo de los puntos de corte ¨®ptimos para la medici¨®n de part¨ªculas mediante Curvas ROC para discriminar tres niveles de contaminaci¨®n. Resultados: El coeficiente de correlaci¨®n entre las dos mediciones fue 0,779 (p<0,001). Los puntos de corte fueron para 0 UFC. 0,015, para >=10 UFC, 0,037, y para >=100 UFC, 0,053. La sensibilidad para estos puntos fue de 95,83%,100% y 100%, y los ¨ªndices Kappa registraron 0,51, 0,88 y 0,75 respectivamente. Conclusi¨®n: En nuestro estudio la correlaci¨®n entre las medidas es notable; la medici¨®n fotom¨¦trica de part¨ªculas puede ser una alternativa para llevar a cabo alguno de los controles rutinarios de bioseguridad (AU)

Objective: Validate a photometric on-air particle measurement system in order to perform ambient bio-security checks in operating rooms and other clean rooms within hospitals. Material and methods: A total of 144 coupled air samples were performed, 88 in 8 different operating rooms with conventional ventilation systems and 3-level filtering and 56 in 9 different rooms without specific ventilation systems. Particles were measured in size between 0,1 to 10 ¦Ìm with the photometric system in mg/m3. Simultaneously in the rooms are performed the sampling air method with impact on culture media. Incubation period is 5 days and count is performed in colony-forming units (CFU/1000L). Finally, optimal cut-points in particles measure were calculated using ROC curves in order to discriminate the three different contamination levels. Results: Spearma´s correlation coefficient was 0,779 p<0,001. Sensitivity for cut-points in particle counting for the different contamination levels was 95,83% ,100% and 100% respectively, and the corresponding Kappa indexes were 0,51; 0,88 and 0,75. Conclusion: Correlation among measurements is notable. Particle measurement can be a worthy alternative for some of the routine bio-security checks (AU)

X-ray absorption spectroscopy of ground and excited rhenium-carbonyl-diimine complexes: evidence for a two-center electron transfer.

Steady-state and picosecond time-resolved X-ray absorption spectroscopy is used to study the ground and lowest triplet states of [ReX(CO)(3)(bpy)](n+), X = Etpy (n = 1), Cl, or Br (n = 0). We demonstrate that the transient spectra at both the Re L(3)- and Br K-edges show the emergence of a pre-edge feature, absent in the ground-state spectrum, which is associated with the electron hole created in the highest occupied molecular orbital following photoexcitation. Importantly, these features have the same dynamics, confirming previous predictions that the low-lying excited states of these complexes involve a two-center charge transfer from both the Re and the ligand, X. We also demonstrate that the DFT optimized ground and excited structures allow us to reproduce the experimental XANES and EXAFS spectra. The ground-state structural refinement shows that the Br atom contributes very little to the latter, whereas the Re-C-O scattering paths are dominant due to the so-called focusing effect. For the excited-state spectrum, the Re-X bond undergoes one of the largest changes but still remains a weak contribution to the photoinduced changes of the EXAFS spectrum.

Objective differential classification of thyroid lesions by nuclear quantitative assessment.

Quantitative nuclear parameters estimated by morphometric and stereological methods in combination with discriminant analysis were used in order to evaluate the diagnostic efficiency of thyroid lesions. This study includes 55 patients with thyroid pathology. Samples of follicular adenomas, follicular carcinomas, and papillary carcinomas were examined by image analysis to obtain size and form nuclear parameters. Stepwise discriminant analyses were performed. There was an increase in nuclear size from follicular adenomas to follicular carcinomas, and a greater increase from follicular carcinomas to papillary carcinomas. The increase was more significant when the three-dimensional estimates of the volume-weighted mean nuclear volume were assessed. No significant differences between follicular adenomas and follicular carcinomas were found with respect to the nuclear form factors, however, a significant increase in nuclear elongation and irregularity was registered between follicular and papillary tumors (p < 0.01). The overall accuracy rate of discrimination was 75% when the three lesions were included in the analysis, with an efficiency of 85% for papillary carcinoma samples. These percentages increased when two lesion discrimination was performed. The worst discrimination (69% of efficiency) was found between follicular adenomas and follicular carcinomas.

Application of recent stereological tools for unbiased three-dimensional estimation of number and size of nuclei in renal cell carcinoma samples.

New stereological methods have appeared in recent years that allow an unbiased and efficient estimation of quantitative characteristics of three-dimensional biological structures. The aim of this study is to apply the new stereological tools on renal tissue and investigate the changes in the number and size of nuclei in renal cell carcinomas. The simple and easy use of the disector, point-sampled intercepts and selector methods on kidney biopsies is demonstrated. Using these approaches, the mean number of nuclei per unit reference volume: NV(nucl/tis), the volume-weighted mean nuclear volume: nu V(nucl) and the number-weighted mean nuclear volume: nu N(nucl) were estimated in histological sections from 20 renal cell carcinomas. The study was performed on 10 grade 2 and 10 grade 3 renal cell carcinomas previously diagnosed by the pathologist on the basis of nuclear size increase, irregularity and nucleolar prominence. Basically, serial optical kidney sections from a 25-millimicrons thick slice were used for stereological study. The size estimations of the individual particles nu V(nucl) and nu N(nucl) obtained by the 'point-sampled intercepts' and 'selector' methods, respectively, turned out to be the most adequate parameters employed in discriminating between renal carcinoma grades (P less than or = 0.001).

[The glomerular mesangium: a new perspective on its structure and function]. / El mesangio glomerular: una nueva perspectiva de su estructura y función.

OBJECTIVES: The present study describes a new approach to the structure and function of the renal glomeruli, distinct from the traditional concept of structural support and in relationship with the alterations detected in this area in different diseases. METHODS: The structural and ultrastructural observations in the renal glomerulus reported elsewhere were compared with our own findings in different animal experiments. Furthermore, the biochemical and functional results from these studies are presented. RESULTS: Our observations in vivo corroborate the findings reported by other authors and support their hypotheses on the possible myofibroblastic nature of the glomerular mesangial cells and the relationship of the renal mesangium with the glomerular capillaries in areas with no glomerular basement membrane. CONCLUSIONS: The glomerular mesangium is shown to be a fundamental structure for glomerular hemodynamics by regulating the different properties of the mesangial cells and the role of the mesangial matrix in plasma ultrafiltration by processing its different components and preventing their deposition in this area.

Comparative morphological studies of lamb and calf Sertoli cells treated with anabolic agents.

The morphological alterations caused by anabolic steroids (oestradiol and trenbolone acetate) on the Sertoli cells of testicles in animals for human consumption (lambs and calves) were studied. The morphopathological study of the treated lambs revealed delayed development of the seminiferous tubules, which was marked by signs of immaturity and even degeneration of Sertoli cells. The main morphopathological alterations affecting the Sertoli cells in calves occurred as hyperfunction symptoms marked by increased nuclei and smooth endoplasmic reticulum.

[Effect of anabolic hormones on the testis of calves: a morphopathologic and morphometric study]. / Acción de las hormonas anabolizantes sobre el testículo de terneros: estudio morfopatológico y morfométrico.

The present study was undertaken to determine the morphological changes in calf testicular parenchyma following implantation of anabolics. Oestradiol and trenbolone acetate were observed to delay seminiferous tubule development of the calf testis resulting in a derangement of supporting and germinal cell maturation. We also observed an edematous process that primarily involved the interstitium and subsequently involved the interior of the seminiferous epithelium, causing a chain of subsequent changes. Changes in the germinal epithelium showed profound derangement throughout spermatogenesis and was particularly more marked and manifest during spermiogenesis.

[Experimental study on the process of repair-healing of the flexor system in the growing chick]. / Estudio experimental del proceso reparación-cicatrización del aparato flexor del pollo en crecimiento.

In the present work, in view of the concern for tendinous injuries in children hand flexor apparatus, tendinous healing and its functional and morphological recuperation were studied after section and surgical restoration of the leg flexor apparatus of chicken at different growth stages. We conclude that best results are obtained when the rehabilitation begins ten days after surgery.