Los trastornos oculares del espectro alcohólico fetal / Ocular fetal alcohol spectrum disorders

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Biomarcadores de peroxidación lipídica en el humor acuoso de pacientes con glaucoma primario de ángulo abierto / Biomarkers of lipid peroxidation in the aqueous humor of primary open-angle glaucoma patients

OBJETIVO: Investigamos la peroxidación lipídica (PEROX) en el glaucoma primario de ángulo abierto (GPAA) y si este mecanismo puede relacionarse con su progresión. MATERIAL Y MÉTODOS: Estudio prospectivo observacional, transversal, analítico no experimental de casos y grupo comparativo, con selección de 175 pacientes quirúrgicos, distribuidos en: 1) grupo diagnosticado de GPAA (GG; n=88) y 2) grupo comparativo de pacientes con cataratas (GC; n=87). Se han obtenido datos demográficos, características de los participantes y estilo de vida. Se realizó un examen oftalmológico centrado en GPAA. Se obtuvieron muestras de humor acuoso al principio de la cirugía programada, que fueron procesadas para determinar el malonildialdehído mediante la técnica del ácido tiobarbitúrico y sustancias reactivas (MDA/TBARS) así como la actividad antioxidante total (AAO) por métodos enzimático-colorimétricos. El estudio estadístico se realizó mediante el programa SPSS 15.0. RESULTADOS: El nivel de MDA/TBARS fue significativamente mayor (p < 0,001) y la AAO significativamente menor (p < 0,001) en el GG que en el GC. El MDA/TBARS correlacionaba directamente con la presión intraocular (PIO) y relación vertical excavación/papilla (CDR). La disminución de la AAO correlacionaba inversamente con la PIO y el CDR. Las diferencias fueron notablemente mayores en el GG para obesidad, hábito alcohólico, ansiedad, depresión y sedentarismo. En el análisis multivariante las variables que presentaron una mejor capacidad predictiva fueron MDA, PIO, AAO, CDR y la presencia de depresión. CONCLUSIONES: Los pacientes con GPAA están tratados mediante procesos de PEROX que se reflejan en el humor acuoso mediante variaciones en MDA/TBARS y AAO que, además, correlacionan con la PIO y el CDR en el curso del glaucoma. Proponemos que la determinación de MDA/TBARS y AAO en el humor acuoso de los pacientes con GPAA puede utilizarse como biomarcadores predictivos, junto con los cambios en el estilo de vida y otros factores de riesgo relacionados, para mejorar el seguimiento de los glaucomatosos

OBJECTIVE: To investigate the lipid peroxidation (PEROX) processes in primary open-angle glaucoma (POAG) patients, and whether this mechanism may be related to disease progression. MATERIAL AND METHODS: A prospective, observational, cross-sectional, non-experimental, and analytical study was conducted on a case and a comparison group, consisting of 175 surgical patients divided into: 1) POAG group (GG; n=88) and 2) comparison group of patients with cataracts (CG; n=87). Demographic data, patient characteristics, lifestyle data, as well as ophthalmological examination were registered in an Excel spreadsheet. Biochemical data were obtained by processing the aqueous humor collected at the beginning of surgery. Determination of malondialdehyde/thiobarbituric acid reactive substances (MDA/TBARS) and total antioxidant activity (AAO) was assayed using enzymatic-colorimetric methods in the aqueous humor samples. Statistical analysis was performed using SPSS 15.0 software. RESULTS: Aqueous humor MDA/TBARS levels were significantly higher (P<.001) and the AAO significantly lower (P<.001) in the GG than in the GC. The MDA/TBARS directly correlated with intraocular pressure (IOP) values and the cup-to-disc ratio (CDR). Decreased AAO activity correlated inversely with IOP and CDR. Differences between groups were noticeably higher in the GG as regards obesity, alcohol consumption, anxiety, depression, and sedentary lifestyle. In the multivariate analysis, the variables that showed a better predictive ability were: MDA/TBARS, PIO, AAO, CDR, and depression. CONCLUSIONS: The POAG patients have a PEROX background that is reflected in the aqueous humor by variations in MDA/TBARS and AAO. Moreover, both the MDA/TBARS and AAO correlated with IOP values and the CDR. We propose that determination of MDA/TBARS and AAO in the aqueous humor of POAG patients can be used as biomarkers for monitoring the disease, as well the changes in lifestyle and other related risk factors

Biomarkers of lipid peroxidation in the aqueous humor of primary open-angle glaucoma patients. / Biomarcadores de peroxidación lipídica en el humor acuoso de pacientes con glaucoma primario de ángulo abierto.

OBJECTIVE: To investigate the lipid peroxidation (PEROX) processes in primary open-angle glaucoma (POAG) patients, and whether this mechanism may be related to disease progression. MATERIAL AND METHODS: A prospective, observational, cross-sectional, non-experimental, and analytical study was conducted on a case and a comparison group, consisting of 175 surgical patients divided into: 1) POAG group (GG; n=88) and 2) comparison group of patients with cataracts (CG; n=87). Demographic data, patient characteristics, lifestyle data, as well as ophthalmological examination were registered in an Excel spreadsheet. Biochemical data were obtained by processing the aqueous humor collected at the beginning of surgery. Determination of malondialdehyde/thiobarbituric acid reactive substances (MDA/TBARS) and total antioxidant activity (AAO) was assayed using enzymatic-colorimetric methods in the aqueous humor samples. Statistical analysis was performed using SPSS 15.0 software. RESULTS: Aqueous humor MDA/TBARS levels were significantly higher (P<.001) and the AAO significantly lower (P<.001) in the GG than in the GC. The MDA/TBARS directly correlated with intraocular pressure (IOP) values and the cup-to-disc ratio (CDR). Decreased AAO activity correlated inversely with IOP and CDR. Differences between groups were noticeably higher in the GG as regards obesity, alcohol consumption, anxiety, depression, and sedentary lifestyle. In the multivariate analysis, the variables that showed a better predictive ability were: MDA/TBARS, PIO, AAO, CDR, and depression. CONCLUSIONS: The POAG patients have a PEROX background that is reflected in the aqueous humor by variations in MDA/TBARS and AAO. Moreover, both the MDA/TBARS and AAO correlated with IOP values and the CDR. We propose that determination of MDA/TBARS and AAO in the aqueous humor of POAG patients can be used as biomarkers for monitoring the disease, as well the changes in lifestyle and other related risk factors.

Los miRNAs como potenciales biomarcadores de las enfermedades oculares / MicroRNAs as potential biomarkers of eye diseases

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Tratamiento con antioxidantes / Antioxidants treatment of ocular diseases

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Evidence for kinesin-related proteins associated with the axoneme of retinal photoreceptors.

Situated at the junction between inner and outer segment, the connecting cilium of retinal photoreceptors supports regulated transport of molecules that function distally, while restricting diffusion of membrane proteins from one plasmalemmal domain to the other. Both functions are thought to be performed by a group of proteins stably or transiently associated with the axoneme. We have identified two types of unique polypeptides which associated with the axoneme in a nucleotide-dependent manner: they bind to the axonemes in the presence of adenosine monophosphate (AMP)-PNP, and are solubilized in the presence of adenosine triphosphate (ATP). The first group contained glyconjugates, previously shown to be part of the axoneme-plasmalemma cross-linkers at the connecting cilium. The second group cross-reacted with antibodies to two different conserved peptide sequences (called LAGSE and HIPYR) of kinesin-related proteins, and included polypeptides of approximately 85-97 kDa. Immunofluorescence microscopy of whole-mounted axonemes with the two anti-kinesin antibodies showed labeling throughout the axoneme, including the connecting cilium-basal body region. These results suggest that the identified proteins may serve as motor molecules for transport of material to the outer segment via the connecting cilium.

Tunicamycin does not inhibit transport of phosphatidylinositol to Xenopus rod outer segments.

Tunicamycin inhibits the dolichol pathway for N-linked glycosylation of proteins, including photoreceptor opsin, and causes a buildup of tubulo-vesicular profiles in the intersegmental space between photoreceptor rod inner and outer segments associated with disruption of new disc assembly. We tested the hypothesis that a tunicamycin lesion in photoreceptors would block lipid transport into the outer segment. Adult Xenopus retinas were preincubated in dim red light with 20 micrograms ml-1 of tunicamycin for one hour followed by incubation in the light for 2-6 h with tunicamycin plus either [3H]mannose, [3H]leucine, [2-(3)H]glycerol or [3H]myo-inositol. Tunicamycin caused accumulation of tubulo-vesicular membranes in the intersegmental space and significantly reduced both [3H]leucine and [3H]mannose incorporation into the basal region of rod outer segments. However, tunicamycin had no effect on [3H]glycerol incorporation into the rod outer segment phospholipids. After 5 h incubation with [3H]glycerol, radiolabel in outer segment fractions was associated primarily with phosphatidylinositol in both control and tunicamycin treated retinas. Quantitative light microscope autoradiography of both [3H]glycerol and [3H]inositol labelled retinas showed diffuse labelling over the entire rod outer segment in both control and tunicamycin treated retinas with no accumulation of radioactivity in the basal discs of control retinas or in the tubulo-vesicular structures in the intersegmental space of tunicamycin treated retinas. Our results indicate that despite the morphological disruption and inhibition of glycoprotein transport to outer segments after tunicamycin treatment, transport of labelled phosphatidylinositol occurs normally. These data add to a growing body of evidence separating the lipid and protein transport pathways to the outer segment.