Acid-sensing ion channels (ASICs) 2 and 4.2 are expressed in the retina of the adult zebrafish.

Acid-sensing ion channels (ASICs) are H(+)-gated, voltage-insensitive cation channels involved in synaptic transmission, mechanosensation and nociception. Different ASICs have been detected in the retina of mammals but it is not known whether they are expressed in adult zebrafish, a commonly used animal model to study the retina in both normal and pathological conditions. We study the expression and distribution of ASIC2 and ASIC4 in the retina of adult zebrafish and its regulation by light using PCR, in situ hybridization, western blot and immunohistochemistry. We detected mRNA encoding zASIC2 and zASIC4.2 but not zASIC4.1. ASIC2, at the mRNA or protein level, was detected in the outer nuclear layer, the outer plexiform layer, the inner plexiform layer, the retinal ganglion cell layer and the optic nerve. ASIC4 was expressed in the photoreceptors layer and to a lesser extent in the retinal ganglion cell layer. Furthermore, the expression of both ASIC2 and ASIC4.2 was down-regulated by light and darkness. These results are the first demonstration that ASIC2 and ASIC4 are expressed in the adult zebrafish retina and suggest that zebrafish could be used as a model organism for studying retinal pathologies involving ASICs.

Fiabilidad en el cribado de la retinopatía del prematuro mediante el análisis de retinografías / Reliability of retinal imaging screening in retinopathy of prematurity

INTRODUCCIÓN: La retinopatía del prematuro (ROP) es una de las principales causas de ceguera infantil potencialmente evitable. Los avances en los cuidados neonatales consiguen la supervivencia de niños de bajo peso extremo asociado con una mayor incidencia de la enfermedad. El objetivo de este estudio es evaluar la fiabilidad en el diagnóstico de la ROP a través de retinografías obtenidas con la cámara de campo amplio RetCam3 y estudiar la variabilidad en el diagnóstico de ROP en función del evaluador. MATERIAL Y MÉTODOS: El examen con oftalmoscopio indirecto fue realizado por un oftalmólogo pediátrico experto en ROP. Las imágenes retinianas fueron obtenidas por el mismo oftalmólogo y un técnico especializado en la captura de imágenes digitales. Un total de 30sets de imágenes fueron analizados por 3 grupos enmascarados: grupo A (8 oftalmólogos), grupo B (5 expertos en visión) y grupo C (2 oftalmólogos expertos en ROP). RESULTADOS: Acorde con el diagnóstico mediante oftalmoscopia indirecta, la sensibilidad (26-93), el índice Kappa (0,24-0,80) y el porcentaje de aciertos fueron estadísticamente significativos en el grupo C para el diagnóstico de ROP tipo1. En el diagnóstico de ROP tipo1+tipo2 el índice Kappa (0,17-0,33) y el porcentaje de aciertos (58-90) fueron estadísticamente significativos, obteniendo valores superiores en el grupo C. CONCLUSIONES: El diagnóstico realizado por oftalmólogos expertos en ROP con el retinógrafo móvil RetCam3 ha demostrado ser un método fiable

INTRODUCTION: The retinopathy of prematurity (ROP) is a potentially avoidable cause of blindness in children. The advances in neonatal care make the survival of extremely premature infants, who show a greater incidence of the disease, possible. The aim of the study is to evaluate the reliability of ROP screening using retinography imaging with the RetCam3 wide-angle camera and also study the variability of ROP diagnosis depending on the evaluator. MATERIAL AND METHODS: The indirect ophthalmoscopy exam was performed by a Pediatric ROP-Expert Ophthalmologist. The same ophthalmologist and a technician specialized in digital image capture took retinal images using the RetCam3 wide-angle camera. A total of 30image sets were analyzed by 3 masked groups: group A (8 ophthalmologists), group B (5 experts in vision), and group C (2 ROP-expert ophthalmologists). RESULTS: According to the diagnosis using indirect ophthalmoscopy, the sensitivity (26-93), Kappa (0.24-0.80), and the percent agreement were statistically significant in group C for the diagnosis of ROP Type1. In the diagnosis of ROP Type1+Type2, Kappa (0.17-0.33) and the percent agreement (58-90) were statistically significant, with higher values in group C. CONCLUSION: The diagnosis, carried out by ROP-expert ophthalmologists, using the wide-angle camera RetCam3 has proved to be a reliable method

Espesor macular medido con tomografía de coherencia óptica en ojos pseudoafáquicos con implante amarillo vs. transparente / Macular thickness measured by optical coherence tomography in pseudoaphakic eyes with clear vs yellow implant

OBJETIVO: Evaluar mediante tomografía de coherencia óptica (OCT) las variaciones de espesor macular producidas a lo largo del tiempo en ojos pseudoafáquicos implantados con una lente intraocular (LIO) transparente en comparación con sus respectivos ojos contralarerales implantados con LIO amarilla. MÉTODOS: El espesor macular de 36 ojos de 18 sujetos fue evaluado mediante OCT. Los sujetos presentaban edades superiores a 65 años y habían sido intervenidos de cataratas en ambos ojos en 2 cirugías independientes. La principal característica de los individuos es que llevaban implantada una LIO con diferente absorción en cada ojo: transparente (absorbente de la radiación ultravioleta) y amarilla (con filtro adicional absorbente de las radiaciones violeta-azul del espectro visible). El espesor macular se evaluó en 2 sesiones separadas en el tiempo por un intervalo de tiempo de 5 años, mediante el sistema Stratus-OCT (protocolo fast macular thickness). Se analizaron estadísticamente las diferencias en la evolución del espesor macular entre ojos con diferente tipo de LIO. RESULTADOS: Tras 5 años de seguimiento, se observó que los ojos implantados con LIO transparente manifestaban una reducción del espesor macular estadísticamente significativa, superior a la esperada por el aumento de la edad. Sin embargo, los ojos implantados con LIOs amarillas mantuvieron su espesor macular estable. La disminución del espesor macular promedio en ojos implantados con LIO transparente fue de 5 ± 8 μm (p = 0,02) y la reducción del espesor foveal fue de 10 ± 17 μm (p = 0,02). CONCLUSIONES: Los cambios de espesor macular producidos en ojos implantados con una LIO amarilla difieren de los cambios manifestados en ojos con LIO transparente. Estas observaciones apuntan a un posible efecto protector de las LIOs amarillas contra los efectos dañinos de la luz en sujetos pseudoafáquicos. Sin embargo, estudios con un mayor tamaño muestral y mayor tiempo de seguimiento son necesarios para confirmar que la protección inducida por este tipo de LIO es clínicamente significativa

OBJECTIVE: To study the use of optical coherence tomography (OCT), for measuring the macular thickness variations produced over time in elderly pseudophakic subjects implanted with a clear intraocular lens (IOL) in one eye, and a yellow IOL in the other eye. METHODS: Macular thickness measurements were obtained in the 36 eyes of 18 subjects over 65 years, with cataracts surgically removed from both eyes and implanted with different absorbance (clear and yellow) IOLs in 2 separate surgeries. Stratus-OCT was used to determine the macular thickness in 2 sessions with 5 years of difference. RESULTS: After 5 years of follow-up, the eyes implanted with clear IOLs revealed a significant decrease in macular thickness. However, in eyes implanted with yellow IOLs the macular thickness remained stable. The mean overall decrease in macular thickness in eyes implanted with clear IOLs was 5 ± 8 μm (P=0.02), and foveal thickness reduction was 10 ± 17 μm (P=0.02). CONCLUSIONS: The macular thickness changes produced in eyes implanted with a yellow IOL differ from those with a clear IOL. These observation point to a possible protective effect of yellow IOL against the harmful effects of light in elderly pseudophakic subjects. However, studies with a longer follow-up are still needed to confirm that the protection provided by this IOL model is clinically significant

[Macular thickness measured by optical coherence tomography in pseudoaphakic eyes with clear vs yellow implant]. / Espesor macular medido con tomografía de coherencia óptica en ojos pseudoafáquicos con implante amarillo vs. transparente.

OBJECTIVE: To study the use of optical coherence tomography (OCT), for measuring the macular thickness variations produced over time in elderly pseudophakic subjects implanted with a clear intraocular lens (IOL) in one eye, and a yellow IOL in the other eye. METHODS: Macular thickness measurements were obtained in the 36 eyes of 18 subjects over 65 years, with cataracts surgically removed from both eyes and implanted with different absorbance (clear and yellow) IOLs in 2 separate surgeries. Stratus-OCT was used to determine the macular thickness in 2 sessions with 5 years of difference. RESULTS: After 5 years of follow-up, the eyes implanted with clear IOLs revealed a significant decrease in macular thickness. However, in eyes implanted with yellow IOLs the macular thickness remained stable. The mean overall decrease in macular thickness in eyes implanted with clear IOLs was 5 ± 8 µm (P=.02), and foveal thickness reduction was 10 ± 17 µm (P=.02). CONCLUSIONS: The macular thickness changes produced in eyes implanted with a yellow IOL differ from those with a clear IOL. These observation point to a possible protective effect of yellow IOL against the harmful effects of light in elderly pseudophakic subjects. However, studies with a longer follow-up are still needed to confirm that the protection provided by this IOL model is clinically significant.

[Reliability of retinal imaging screening in retinopathy of prematurity]. / Fiabilidad en el cribado de la retinopatía del prematuro mediante el análisis de retinografías.

INTRODUCTION: The retinopathy of prematurity (ROP) is a potentially avoidable cause of blindness in children. The advances in neonatal care make the survival of extremely premature infants, who show a greater incidence of the disease, possible. The aim of the study is to evaluate the reliability of ROP screening using retinography imaging with the RetCam 3 wide-angle camera and also study the variability of ROP diagnosis depending on the evaluator. MATERIAL AND METHODS: The indirect ophthalmoscopy exam was performed by a Pediatric ROP-Expert Ophthalmologist. The same ophthalmologist and a technician specialized in digital image capture took retinal images using the RetCam 3 wide-angle camera. A total of 30 image sets were analyzed by 3 masked groups: group A (8 ophthalmologists), group B (5 experts in vision), and group C (2 ROP-expert ophthalmologists). RESULTS: According to the diagnosis using indirect ophthalmoscopy, the sensitivity (26-93), Kappa (0.24-0.80), and the percent agreement were statistically significant in group C for the diagnosis of ROP Type 1. In the diagnosis of ROP Type 1+Type 2, Kappa (0.17-0.33) and the percent agreement (58-90) were statistically significant, with higher values in group C. CONCLUSION: The diagnosis, carried out by ROP-expert ophthalmologists, using the wide-angle camera RetCam 3 has proved to be a reliable method.

Light regulates the expression of the BDNF/TrkB system in the adult zebrafish retina.

The retina of the adult zebrafish express brain-derived neurotrophic factor (BDNF) and its signaling receptor TrkB. This functional system is involved in the biology of the vertebrate retina and its expression is regulated by light. This study was designed to investigate the effects of cyclic (12 h light/12 h darkness) or continuous (24 h) exposure during 10 days to white light, white-blue light, and blue light, as well as of darkness, on the expression of BDNF and TrkB in the retina. BDNF and TrkB were assessed in the retina of adult zebrafish using quantitative real-time polymerase chain reaction and immunohistochemistry. Exposure to white, white-blue, and blue light causes a decrease of BDNF mRNA and of BDNF immunostaining, independently of the pattern of light exposition. Conversely, in the same experimental conditions, the expression of TrkB mRNA was upregulated and TrkB immunostaining increased. Exposition to darkness diminished BDNF and TrkB mRNAs, and abolished the immunostaining for BDNF but not modified that for TrkB. These results demonstrate the regulation of BDNF and TrkB by light in the retina of adult zebrafish and might contribute to explain some aspects of the complex pathophysiology of light-induced retinopathies.

Primary renal lymphoma: long-term results of two patients treated with a chemotherapy + rituximab protocol.

Primary renal lymphoma (PRL) is a rare disease of which the etiology and pathogenesis remain controversial, and there is currently no standard treatment for it. We present the results of a long-term followup of two patients who were diagnosed with PRL and treated with cyclophosphamide, adriamycin, vincristine, prednisolone and rituximab (CHOP + R) regimen. Both patients reached a complete response, and there is no evidence of recurrence after 4.5- and 5-year followup periods. Based on our experience and other recently published studies, we recommend the combination of CHOP + rituximab as the elective treatment for this disease. To our knowledge, this is the longest followup period with a complete response that has been reported with this modality of treatment.

Expression of TRPV4 in the zebrafish retina during development.

The transient receptor potential (TRP) channels are involved in sensing mechanical/physical stimuli such as temperature, light, pressure, as well as chemical stimuli. Some TRP channels are present in the vertebrate retina, and the occurrence of the multifunctional channel TRP vanilloid 4 (TRPV4) has been reported in adult zebrafish. Here, we investigate the expression and distribution of TRPV4 in the retina of zebrafish during development using polymerase chain reaction (PCR), Western blot, and immunohistochemistry from 3 days post fertilization (dpf) until 100 dpf. TRPV4 was detected at the mRNA and protein levels in the eye of zebrafish at all ages sampled. Immunohistochemistry revealed the presence of TRPV4 in a population of the retinal cells identified as amacrine cells on the basis of their morphology and localization within the retina, as well as the co-localization of TRPV4 with calretinin. TRPV4 was first (3 dpf) found in the soma of cells localized in the inner nuclear and ganglion cell layers, and thereafter (10 dpf) also in the inner plexiform layer. The adult pattern of TRPV4 expression was achieved by 40 dpf the expression being restricted to the soma of some cells in the inner nuclear layer and ganglion cell layers. These data demonstrate the occurrence and developmental changes in the expression and localization of TRPV4 in the retina of zebrafish, and suggest a role of TRPV4 in the visual processing.

Expression and cell localization of brain-derived neurotrophic factor and TrkB during zebrafish retinal development.

Brain-derived neurotrophic factor (BDNF) signaling through TrkB regulates different aspects of neuronal development, including survival, axonal and dendritic growth, and synapse formation. Despite recent advances in our understanding of the functional significance of BDNF and TrkB in the retina, the cell types in the retina that express BDNF and TrkB, and the variations in their levels of expression during development, remain poorly defined. The goal of the present study is to determine the age-dependent changes in the levels of expression and localization of BDNF and TrkB in the zebrafish retina. Zebrafish retinas from 10 days post-fertilization (dpf) to 180 dpf were used to perform PCR, Western blot and immunohistochemistry. Both BDNF and TrkB mRNAs, and BDNF and full-length TrkB proteins were detected at all ages sampled. The localization of these proteins in the retina was very similar at all time points studied. BDNF immunoreactivity was found in the outer nuclear layer, the outer plexiform layer and the inner plexiform layer, whereas TrkB immunoreactivity was observed in the inner plexiform layer and, to a lesser extent, in the ganglion cell layer. These results demonstrate that the pattern of expression of BDNF and TrkB in the retina of zebrafish remains unchanged during postembryonic development and adult life. Because TrkB expression in retina did not change with age, cells expressing TrkB may potentially be able to respond during the entire lifespan of zebrafish to BDNF either exogenously administered or endogenously produced, acting through paracrine mechanisms.

Role of metalloproteases in retinal degeneration induced by violet and blue light.

INTRODUCTION: An essential role for metalloproteases (MMPs) has been described in blood vessel neoformation and the removal of cell debris. MMPs also play a key role in degenerative processes and in tumors. The participation of these enzymes in light-induced phototoxic processes is supported by both experimental and clinical data. Given that patients with age-related macular degeneration often show deposits, or drusen, these deposits could be the consequence of deficient MMP production by the pigment epithelium. OBJECTIVE: To gain insight into the regulation of metalloproteases in the pathogenia of retinal degeneration induced by light. MATERIALS AND METHODS: We examined the eyes of experimental rabbits exposed for 2 years to circadian cycles of white light, blue light and white light lacking short wavelengths. For the trial the animals had been implanted with a transparent intraocular lens (IOL) and a yellow AcrySof((R)) IOL, one in each eye. After sacrificing the animals, the retinal layer was dissected from the eye and processed for gene expression analyses in which we examined the behavior of MMP-2, MMP-3 and MMP-9. RESULTS: MMP-2 expression was unaffected by the light received and type of IOL. However, animals exposed to white light devoid of short wavelengths or those fitted with a yellow IOL showed 2.9- and 3.6-fold increases in MMP-3 expression, respectively compared to controls. MMP-9 expression levels were also 3.1 times higher following exposure to blue light and 4.6 times higher following exposure to white light lacking short wavelengths or 4.2 times higher in eyes implanted with a yellow IOL. CONCLUSION: Exposure to long periods of light irrespective of its characteristics leads to the increased expression of some MMPs. This alteration could indicate damage to the extracellular matrix and have detrimental effects on the retina.

Determinación del patrón de conectividad cerebral a partir de EEG en presencia de artefactos / Determining brain-connectivity patterns in presence of artefacts using EEG

Los diferentes estados del cerebro provocan la formacióntemporal de circuitos corticales cuya discriminación experimentalabre el camino al estudio y caracterización de respuestasde comportamiento. En este trabajo recogemos eilustramos en ejemplos los pasos necesarios para la determinaciónde patrones de conectividad funcional entre zonascorticales a partir de los registros EEG. El primer paso, lasupresión de artefactos de diferentes tipos, se realizamediante el análisis de componentes independientes quepermite reconstruir la actividad neuronal subyacente alartefacto e indica en qué grado está presente el artefactosobre cada electrodo. En el segundo paso determinamos laconectividad funcional a partir de registros preprocesados.Empleamos métodos estadísticos: la Coherencia EspectralParcial y dDTF (direct Directed Transfer Function) que proporcionanun patrón de conectividad teniendo en cuenta elnivel de sincronización entre señales de los electrodos.Demostramos y cuantificamos las diferencias el la topologíade la red cortical utilizando como ejemplo dos estados del sujeto: ojos abiertos y cerrados. Para no cerrarnos a la ideade que dos estructuras interactúan solo cuando están sincronizadas,también consideramos las señales registradasen un contexto determinista. Demostramos que la dinámicalocal en el estado de ojos abiertos es más compleja, debidoa que el patrón de conectividad es más denso

The different brain states incite in the generation of temporalcortical circuits, whose experimental discriminationallows the study and characterization of behavioral responses.In this work, we summarize and illustrate in examplesthe needed steps for the determination of functional connectivitypatterns among cortical areas from EEG recordings.The firts step, different types of artifacts removal, istreated by means of independent component analysis thatallows the recovering of neural activity under the artifactand show the presence degree of the artifact over eachelectrode position. In the second steps we determine thefunctional connectivity from the preprocessed recordings.We employ statistical methods: Partial Spectral Coherenceand dDTF (direct Directed Transfer Function), that providethe connectivity patterns taking into account the synchronizationlevel among the signal. We demostrate and quantifythe differences in the cortical network topology usingas an example two subject states: open and close eyes. Tobe opened to the idea that two structures interact only when they are synchronized, we also consider the signal ina deterministic framework. We demostrate that the localdynamic in open eye state is more complex, due to theconnectivity pattern is more dense

[A new device for measuring contrast sensitivity with and without glare]. / Nuevo instrumento para medir la sensibilidad al contraste sin y con deslumbramiento.

PURPOSE/METHOD: To measure the photopic contrast sensitivity, with and without glare, by means of a new instrument. Seventy eight right eyes of 49 young adults and of 29 adults subjects between 35 and 55 years were studied. Contrast sensitivity was measured with the Contrast Glaretester CGT-1000 (Takagi, Japan) that determines the contrast threshold by means of an automated strategy for 6 spatial frecuencies. RESULTS/CONCLUSIONS: The values of contrast sensitivity were similar to those obtained with other clinical tests. Contrast sensitivity, without and with glare, decreased significantly with the age. However, glare did not modify the contrast sensitivity under photopic conditions.

Nuevo instrumento para medir la sensibilidad al contraste sin y con deslumbramiento / A new device for measuring contrast sensitivity with and without glare

Objetivo/Método: Valorar la sensibilidad al contraste fotópica, sin y con deslumbramiento con un nuevo instrumento. Se estudiaron 78 ojos derechos de 49 adultos jóvenes y de 29 adultos entre 35 y 55 años. La sensibilidad al contraste se midió con el Contrast Glaretester CGT-1000 mediante una estrategia automatizada de reconocimiento para seis frecuencias espaciales. Resultados/Conclusiones: Los valores de sensibilidad al contraste fueron semejantes a los obtenidos con otros tests clínicos. El aumento de la edad disminuyó significativamente la sensibilidad al contraste sin y con deslumbramiento. Sin embargo, el deslumbramiento no modificó la sensibilidad al contraste fotópica (AU)

Purpose/Method: To measure the photopic contrast sensitivity, with and without glare, by means of a new instrument. Seventy eight right eyes of 49 young adults and of 29 adults subjects between 35 and 55 years were studied. Contrast sensitivity was measured with the Contrast Glaretester CGT-1000 (Takagi, Japan) that determines the contrast threshold by means of an automated strategy for 6 spatial frecuencies. Results/Conclusions: The values of contrast sensitivity were similar to those obtained with other clinical tests. Contrast sensitivity, without and with glare, decreased significantly with the age. However, glare did not modify the contrast sensitivity under photopic conditions (AU)