Glutathione-dependent formaldehyde dehydrogenase (ADH3) and low km mitochondrial aldehyde dehydrogenase (ALDH2). New evidence for differential expression in the rat retina in response to oxidative stress.

OBJECTIVES: Epidemiological and experimental studies support the involvement of lipid peroxidation (LPO) in retinal diseases. In addition to other pathogenic mechanisms not fully understood, the possibility remains that peroxidic aldehydes, acting as cytotoxic chemicals, mediate in the progression of chronic ocular disorders. METHODS: To test proper mechanisms involved in removing peroxidic aldehydes from the retina, in an attempt to understand long-lasting changes induced by LPO, the oxidative and antioxidant enzymatic activities, as well as the retinal distribution and activity of glutathione-dependent formaldehyde dehydrogenase (ADH3) and low km mitochondrial aldehyde dehydrogenase (ALDH2), were studied and compared with induced LPO sites in the adult rat retina. Biochemical enzymatic-colorimetric assays, histochemical and immunocytochemical analyses were carried out in the mature rat retinal tissues. Statistics were performed by the SPSS 15.0 program. RESULTS: Data revealed (1) the noticeable LPO and glutathione (GSH) enzymatic system retinal and optic nerve activities; (2) the retinal expression and distribution of both the ADH3 and ALDH2; and (3) the co-localisation of iron/nicotine adenine dinucleotide phosphate (Fe/NADPH)-induced LPO, mainly in the outermost and innermost retinal strata, as compared to the rest of the retinal layers (p < 0.001). CONCLUSIONS: Changes in the GSH and GSH enzymatic system, and in the ADH3 and ALDH2 retinal expression and distribution might be crucial in assessing the intrinsic mechanisms of LPO-mediated retinopathies. Further research is needed to evaluate these findings and their application to new ophthalmological therapy.

[Involvement of nitric oxide and other molecules with redox potential in primary open angle glaucoma]. / Implicaciones del óxido nítrico y otras moléculas con potencial redox en el glaucoma primario de ángulo abierto.

PURPOSE: Nitric oxide (NO) and other molecules with redox potential are involved in cell signalling, including endothelial-dependent relaxation and the maintenance of vascular homeostasis. We investigated the availability of NO and the formation of reactive oxygen species (ROS) in the aqueous humour and its relationship to the pathogenic mechanisms of primary open-angle glaucoma (POAG). METHODS: We analysed biochemically aqueous humour samples from patients having anterior segment surgery that were divided into two separate groups: 1) patients having a Watson's trabeculectomy because of worsening of the glaucoma evolution (GG; n=60), and 2) a comparative group of individuals having phacoemulsification for non-complicated cataracts (CG; n=60). Enzymatic-colorimetric methods were used to analyse the NO concentration, the lipid peroxidation by-product malondialdehyde (MDA) and the total antioxidant status (TAS). Statistical analysis was carried out in the two groups by means of the SPSS 15.0 programme. RESULTS: A significant increase in both the NO concentration (p<0.05) and MDA levels (p<0.05), and a significant decrease of the TAS (p<0.05) were detected in the GG versus the CG samples. CONCLUSIONS: Changes in NO availability and the concomitance of oxidative stress in the aqueous humour of the POAG patients may be useful markers for identifying those at risk of glaucoma progression and visual loss.

Implicaciones del óxido nítrico y otras moléculas con potencial redox en el glaucoma primaria de ángulo abierto / Involvement of nitric oxide and other molecules with redox potential in primary open angle glaucoma

Objetivos: El óxido nítrico (ON) y otras moléculas con potencial red-ox están relacionados con mecanismos de transmisión de señales, incluyendo la regulación de la permeabilidad vascular y la homeostasis. Nos proponemos investigar la presencia de ON y de especies reactivas del oxígeno (EROx) en el humor acuoso y su relación con los mecanismos patogénicos del glaucoma primario de ángulo abierto (GPAA). Métodos: Se ha analizado bioquímicamente el humor acuoso, que fue extraído al comienzo de la cirugía de segmento anterior, de dos grupos de individuos: 1) pacientes programados para trabeculectomía de Watson, por empeoramiento de los parámetros de riesgo del glaucoma (GG; n=60) y 2) grupo comparativo de sujetos intervenidos mediante facoemulsificación para extracción de las cataratas no complicadas (GC; n=60). Las determinaciones del ON, especies reactivas del oxígeno (EROx) y la actividad antioxidante total (AOXT) fueron llevadas a cabo mediante técnicas enzimático-colorimétricas. Resultados: Se ha observado un aumento significativo de la concentración de ON y de EROx (MDA) y, paralelamente, una disminución significativa de antioxidantes (AOXT) en el humor acuoso de los pacientes glaucomatosos en comparación con los individuos del GC. Conclusiones: Las anomalías en la disponibilidad de ON y la concomitancia de estrés oxidativo en el humor acuoso sugieren que estas biomoléculas pueden utilizarse como marcadores de evolución de la enfermedad glaucomatosa y ayudar a establecer individualizadamente el riesgo de pérdida de visión

Purpose: Nitric oxide (NO) and other molecules with redox potential are involved in cell signalling, including endothelial-dependent relaxation and the maintenance of vascular homeostasis. We investigated the availability of NO and the formation of reactive oxygen species (ROS) in the aqueous humour and its relationship to the pathogenic mechanisms of primary open-angle glaucoma (POAG). Methods: We analysed biochemically aqueous humour samples from patients having anterior segment surgery that were divided into two separate groups: 1) patients having a Watson’s trabeculectomy because of worsening of the glaucoma evolution (GG; n=60), and 2) a comparative group of individuals having phacoemulsification for non-complicated cataracts (CG; n=60). Enzymatic-colorimetric methods were used to analyse the NO concentration, the lipid peroxidation by-product malondialdehyde (MDA) and the total antioxidant status (TAS). Statistical analysis was carried out in the two groups by means of the SPSS 15.0 programme. Results: A significant increase in both the NO concentration (p<0.05) and MDA levels (p<0.05), and a significant decrease of the TAS (p<0.05) were detected in the GG versus the CG samples. Conclusions: Changes in NO availability and the concomitance of oxidative stress in the aqueous humour of the POAG patients may be useful markers for identifying those at risk of glaucoma progression and visual loss (Arch Soc Esp Oftalmol 2008; 83: 365-372)

[Study of apoptosis and mitosis mechanisms in the eye. Experimental model of gestational toxic syndrome]. / Estudio de los mecanismos de apoptosis y mitosis en el globo ocular. Modelo experimental del síndrome tóxico gestacional.

OBJECTIVE: To improve knowledge of the mechanisms of cellular differentiation and proliferation during retinal development, by studying cellular and molecular damage in a rat model of prenatal ethanol exposure. METHODS: Female, juvenile Wistar rats (200g body weight) and their offspring were divided into two groups, which were fed a liquid diet: 1) ethanol-exposed group (5% ethanol weight/vol as 35% of daily total calories) and 2) isocaloric control group (maltose/dextrin as 35% of daily total calories). Eyeballs were obtained at 21 days of gestation, embedded in paraffin, and immunodetection procedures performed on apoptotic (TUNEL) and mitotic profiles, which were observed and photographed using a confocal microscope. RESULTS: Analysis of the microphotographs revealed a statistically significant increase of apoptotic profiles and a decrease in mitotic profiles in the ethanol exposed group compared to controls (p<0.05). Ganglion cells and photoreceptors showed more changes than other retinal cell phenotypes. These findings suggest that abnormalities in the differentiation and proliferation processes of the retina were caused by the alcohol exposure. CONCLUSIONS: Alcohol abuse during pregnancy alters development of the visual system by inducing developmental changes in the mitotic and apoptotic processes of the retina. These latter changes may be the result of changes in the expression of regulatory genes as well as the result of alteration in signalling pathways for both differentiation-proliferation and apoptotic events.

Estudio de los mecanismos de apoptosis y mitosis en el globo ocular. Modelo experimental del síndrome tóxico gestacional / Study of apoptosis and mitosis mechanisms in the eye. Experimental model of gestational toxic syndrome

Objetivo: Profundizar en los conocimientos de los mecanismos de diferenciación y proliferación celular durante el desarrollo de la retina, estudiando los mecanismos de mitosis y apoptosis en un modelo de exposición prenatal al alcohol en la rata. Método: Se utilizaron ratas Wistar (200 g peso) y su descendencia, en dos grupos alimentados con dieta líquida: 1) el grupo expuesto al etanol (5% etanol peso/volumen como 35% calorías diarias totales) y 2) un grupo control isocalórico (carbohidratos como 35% calorías diarias totales). Se obtuvieron los globos oculares el día 21 de gestación para incluirlos en parafina y realizar la inmunodetección de células apoptóticas (TUNEL) y mitóticas esenque se fotografiaron a microscopía confocal, realizando análisis morfológico y morfométrico para estudiar estadísticamente los datos. Resultados: Las microfotografías revelaron un aumento significativo de perfiles apoptóticos (p<0,05) y paralelamente un descenso de procesos mitóticos en el grupo expuesto al etanol frente al control. Las células ganglionares y los fotorreceptores presentaron más diferencias en estos dos procesos que el resto de fenotipos celulares retinianos. Los datos obtenidos sugieren anomalías en los procesos de diferenciación y proliferación celular de la retina causados por la exposición al alcohol. Conclusiones: El abuso de alcohol durante la gestación altera el desarrollo de la retina por inducir anomalías en los procesos mitóticos y apoptóticos. El aumento de apoptosis y disminución de las mitosis pueden deberse a cambios en la expresión de genes reguladores, así como en las vías de señalización de ambos procesos en estadios precoces del desarrollo

Objective: To improve knowledge of the mechanisms of cellular differentiation and proliferation during retinal development, by studying cellular and molecular damage in a rat model of prenatal ethanol exposure. Methods: Female, juvenile Wistar rats (200g body weight) and their offspring were divided into two groups, which were fed a liquid diet: 1) ethanolexposed group (5% ethanol weight/vol as 35% of daily total calories) and 2) isocaloric control group (maltose/dextrin as 35% of daily total calories). Eyeballs were obtained at 21 days of gestation, embedded in paraffin, and immunodetection procedures performed on apoptotic (TUNEL) and mitotic profiles, which were observed and photographed using a confocal microscope. Results: Analysis of the microphotographs revealed a statistically significant increase of apoptotic profiles and a decrease in mitotic profiles in the ethanol exposed group compared to controls (p<0.05). Ganglion cells and photoreceptors showed more changes than other retinal cell phenotypes. These findings suggest that abnormalities in the differentiation and proliferation processes of the retina were caused by the alcohol exposure. Conclusions: Alcohol abuse during pregnancy alters development of the visual system by inducing developmental changes in the mitotic and apoptotic processes of the retina. These latter changes may be the result of changes in the expression of regulatory genes as well as the result of alteration in signalling pathways for both differentiation-proliferation and apoptotic events

[Alcohol consumption by primary care physicians]. / Consumo de alcohol entre los médicos de atención primaria.

OBJECTIVE: To find the consumption of alcoholic drinks by Primary Care doctors. DESIGN: A descriptive study using an anonymous questionnaire. SETTING: Health base areas located in the Baix Llobregat and in Barcelona city. MEASUREMENTS AND MAIN RESULTS: Total coverage was 68.7%. In the group which replied, daily consumption along with week-end consumption predominated. Men consumed alcohol more often and in greater quantity than women. The prevalence of excessive drinkers according to the PAPPS criteria was 5.9%. 29% of the doctors exceeded the level of alcohol consumption considered acceptable by their own criteria, no gender differences being appreciated. Similarly, 33% of them accepted consumption above that recommended by the experts. CONCLUSIONS: The consumption of alcoholic drinks found among Primary Care doctors was low in comparison with other studies of medical groups or the general population. The Primary Care doctor occupies a privileged position in the prevention of excessive consumption of alcoholic drinks, which implies that their own alcohol consumption and training could have an impact on carrying out preventive activities in this field.