Hepatic recovery after damage produced by sub-chronic intoxication with the cyanotoxin microcystin LR.

The effect of sub-chronic exposure of intraperitoneal (i.p.) injections of microcystin-LR (MC-LR) on microscopic tissue architecture, hepatic function and lipid peroxidation has been studied in liver and kidney of mice. Mice were treated i.p. with 25 microg of pure MC-LR/kg body weight or saline solution for 1 month (every 2 days) with the aim of producing an inflictive stage with evident damage. Histopathological analysis of dissected livers of mice showed a disrupted lobar architecture and the development of cytoplasmatic vacuoles. According to this, a significant increase in hepatic lipid content and in lipid peroxidation levels in liver and kidney was found in MC-LR-treated animals when compared with controls. Moreover, serum alkaline phosphatase and aspartate aminotransferase activities showed a significant alteration in MC-LR-treated animals. After damage, progression or recovery was studied for 1 and 2 months of wash-out. The recovery from liver damage was evident at the cytological and physiological level, only the recovery of lobar architecture was incomplete along the period investigated. In conclusion, the present study demonstrates the ability of hepatic tissue to recover from damage produced by sub-chronic MC-LR administration. The dynamic interplay between damage and tissue-repairing response in determining the ultimate outcome of toxicity should be considered in risk-assessment studies.

Occurrence of Microcystis aeruginosa and microcystins in Rio de la Plata river (Argentina)

This paper is the first report on microcystins producer blooms of Microcystis aeruginosa in the Argentinean coast of the R¨ªo de la Plata river, the most important drinkingwater supply of Argentina. The distribution of toxic cyanobacterium Microcystis cf. aeruginosa blooms in the Argentinean coast of the Rio de la Plata river was studied from December 2003 and January 2006. Microcystis aeruginosa persisted in the river with values ranged between 0 -7.8 104 cells ml-1. Samples of two Microcystis aeruginosa water blooms were collected at La Plata river and were analyzed by the mouse bioassay and by high-performance liquid chromatography with Diode-array and MS detector. The samples showed high hepatotoxicityin mouse bioassay and, in accordance, important amount of microcystins. The bloom samples contained microcystins LR and a variant of microcystin with a molecular ion [M+H]+= 1037.8 m/z as major components. The total toxin content found in these samples was 0.94¦Ìg/mg and 0.69¦Ìg/mg of lyophilised cells. We conclude that the presence of toxic clones of Microcystisaeruginosa in the Argentinean coast of the Rio de la Plata is an actual sanitary and environmental problem and that further studies are necessary to make the risk assessment.

Protocolización de melanoma del tracto uveal: A propósito de un caso / Protocolization of melanoma of the uveal tract: apropos of a case

Se presenta la protocolización de las neoplasmas malignas de la cavidad ocular con el objetivo de otorgarle a los oftalmólogos y oncólogos parámetros más precisos para estadificar correctamente a los pacientes, incluirlos en un plan de tratamiento acorde y evaluar sobrevida y calidad de vida. Paciente de sexo masculino, cincuenta y tres años de edad, diabético, hipertenso que consulta por control oftalmológico. Se utiliza el protocolo recomendado por la Asociación de Anatomía-Patológica Quirúrgica de Illinois, Chicago (USA). Las observaciones de ciertos factores histopatológicos ayudan a definir el pronóstico de esta lesión: tipo celular, tamaño y localización tumoral, extensión hacia nervio óptico y esclera, presencia de necrosis, infiltrado linfocitario y figuras mitóticas...

Protocolización de melanoma del tracto uveal: A propósito de un caso / Protocolization of melanoma of the uveal tract: apropos of a case

Se presenta la protocolización de las neoplasmas malignas de la cavidad ocular con el objetivo de otorgarle a los oftalmólogos y oncólogos parámetros más precisos para estadificar correctamente a los pacientes, incluirlos en un plan de tratamiento acorde y evaluar sobrevida y calidad de vida. Paciente de sexo masculino, cincuenta y tres años de edad, diabético, hipertenso que consulta por control oftalmológico. Se utiliza el protocolo recomendado por la Asociación de Anatomía-Patológica Quirúrgica de Illinois, Chicago (USA). Las observaciones de ciertos factores histopatológicos ayudan a definir el pronóstico de esta lesión: tipo celular, tamaño y localización tumoral, extensión hacia nervio óptico y esclera, presencia de necrosis, infiltrado linfocitario y figuras mitóticas...(AU)