Actualización clínica en ojo seco para el médico no oftalmólogo / Clinical update on dry eye disease for non ophthalmologist physicians

La presente revisión de tema ojo seco está orientada a médicos no oftalmólogos. Se realiza un repaso de la anatomía del sistema lagrimal y fisiología básica de la película lagrimal. Se define el concepto de ojo seco, su importancia epidemiológica y su sintomatología. Se realiza un detallado análisis de la clasificación etiológica definiendo las diferencias entre hipolacrimea asociada o no a síndrome de Sjõgren y ojo seco evaporativo de causa intrínseca y extrínseca, con énfasis en los mecanismos fisiopatológicos subyacentes. Se entrega una visión que da cuenta de la complejidad, envergadura y condición multifactorial de este problema de salud visual y se hace énfasis en la necesidad de identificar de manera integral el tipo de ojo seco para poder instalar un tratamiento basado en la corrección del mecanismo subyacente y no a través de aproximación sintomática de la terapia.

The current review of dry eye disease is directed to non ophthalmologist physicians. We perform an assessment of the anatomy of the lacrimal system and basic physiology of the tear film. The definition of dry eye, its epidemiologic importance and symptoms are explained. A detailed analysis of the etiologic classification is described defining the difference between reduction in tear secretion associated or not to Sjõgren's syndrome and evaporative dry eye of intrinsic or extrinsic origin. We highlight the underlying pathophysiologic mechanisms, conveying the complexity, broadness and multi-factorial conditions related to this visual health problem. We stress the need for identifying in a comprehensive manner the type of dry eye in order to install a treatment based on the underlying mechanism and not through a symptomatic approach to therapy.

Volume overload hypertrophy of the newborn heart slows the maturation of enzymes involved in the regulation of fatty acid metabolism.

OBJECTIVES: The purpose of this study was to determine the effect of volume overload hypertrophy in the newborn heart on the cardiac enzymes controlling fatty acid metabolism. BACKGROUND: Shortly after birth, a rise in 5'-adenosine monophosphate-activated protein kinase (AMPK) activity results in the phosphorylation and inhibition of acetyl coenzyme A (CoA) carboxylase (ACC), and a decline in myocardial malonyl CoA levels with increased fatty acid oxidation rates. Whether the early onset of hypertrophy in the newborn heart alters this maturational increase in fatty acid oxidation is unknown. METHODS: Newborn piglets underwent endovascular stenting of the ductus arteriosus on day 1 of life with a 4.5-mm diameter stent, resulting in a left to right shunt, and left ventricular (LV) volume loading. Left ventricular and right ventricular samples from fetal, newborn, three-week control and three-week stented animals were compared. RESULTS: Stenting resulted in echocardiographic evidence of volume overload and myocardial hypertrophy. In control animals, left ventricular ACC activity declined from 274 +/- 30 pmol/mg/min on day 1 to 115 +/- 12 after three weeks (p < 0.05), but did not display this maturation drop in hypertrophied hearts, remaining elevated (270 +/- 50 pmol/mg/min, p < 0.05). At three weeks, malonyl CoA levels remained 2.8-fold higher in hypertrophied hearts than in control hearts. In control hearts, LV AMPK activity increased 178% between day 1 and three weeks, whereas in hypertrophied hearts AMPK activity at three weeks was only 71% of control values, due to a significant decrease in expression of the catalytic subunit of AMPK. CONCLUSIONS: Early onset LV volume overload with hypertrophy results in a delay in the normal maturation of fatty acid oxidation in the newborn heart.

Inmunohistoquímica de factores de crecimiento en trabéculos de pacientes glaucomatosos: resultados preliminares en pacientes con glaucoma primario de ángulo abierto / Growth factors' immunohistochemistry in trabecular tissue of glaucoma patients: preliminar results in patients with primary open angle glaucoma

Las alteraciones ultraestructurales en el glaucoma primario de ángulo abierto (GPAA) se relacionan con cambios a nivel celular y de la matriz extracelular en el tejido trabecular y pericanalicular. Los factores de crecimiento (FC) actúan como señales químicas que difunden desde las células produciendo cambios en la composición, estructura y función de la matriz extracelular. El propósito de este estudio fue describir, con la ayuda de la inmunohistoquímica, la presencia de factores de crecimiento y sus receptores en el tejido trabecular. Nuestras observaciones son sugerentes de la presencia de factor de crecimiento fibroblástico (FGF) y de su receptor (FGFr) en células trabeculares de pacientes con GPAA

Evaluation of vincristine, CCNU and methyl-CCNU at high level doses in an experimental murine renal adenocarcinoma model.

Balb/C mice were implanted with tumor cells from primary tumor in donor animals bearing renal cell adenocarcinoma. Survival time, tumor growth and metastatic occurrence in treated animals were not significantly improved by high dose Methyl-CCNU, CCNU or Vincristine. It was also concluded that the dose levels of Methyl-CCNU and CCNU used for this study were highly toxic causing early death in the animals. Such studies thus fail to support clinical hopes that these agents would be effective for chemotherapy regimens in human renal tumors.