Morphometric changes in C57BL/6 mice retina infected by Toxoplasma gondii ME 49 strain.

This study evaluated the morphometric implications in C57BL/6 mouse retina infected by Toxoplasma gondii, ME 49 strain. Twenty C57BL/6 female mice were divided into group 1 (n=8, intraperitoneally infected with 30 cysts of T. gondii ME 49 strain) and group 2 (n=12 non-infected controls). The eyes were enucleated on the 60th day after infection, fixed and processed for light microscopy. Changes in retinal thickness and in the perimeter/area ratio (P/A) of the retinal layers were analyzed by digital morphometry. We considered that P/A was the measurement of retinal architecture distortion induced by toxoplasmosis. This study considered the ganglion cells and nerve fiber layers as a monolayer, thus six layers of retina were evaluated: photoreceptors (PRL), outer nuclear (ONL), outer plexiform (OPL), inner nuclear (INL), inner plexiform (IPL) and ganglion cells/nerve fiber monolayer (GNL). Histological analysis of infected mouse retina showed inflammatory infiltrate, necrosis, glial reaction and distortion of the retina architecture. It also presented increased thickness (167.8±24.9µm versus 121.1±15.4µm, in controls) and increased retinal thickness within the retinitis foci (187.7±16.6µm versus 147.9±12.2µm out of the retinitis foci). A statistically significant difference in P/A was observed between infected and uninfected mouse retinas. The same was observed in PRL, OPL, INL and GNL. Retinal morphometry may be used to demonstrate differences between infected and uninfected mouse retinas.

Apoptose e Morfometria das Lesões Granulomatosas induzidas pelo Angiostrongylus vasorum em cães / Apoptosis and morphometry of the granulomatous lesions induced by the Angiostrongylus vasorum in dogs

O Angiostrongylus vasorum (Baillet, 1866) é um nematódeo da família Protostrongylidae que habita o átrio e o ventrículo direitos, e artéria pulmonar de cães domésticos e de outras espécies de Canídeos em diversos continentes. A angiostrongilose induz a formação de granulomas de composição e volume variáveis nas diferentes fases do processo nos pulmões e em vários órgãos nos animais acometidos. Fragmentos de pulmão embebidos em parafina e obtidos de 12 animais sem raça definida, infectados experimentalmente com larvas de A. vasorum, foram seccionados a 5mm. Os cortes foram corados em hematoxilina e eosina e analisados ao microscópio óptico. As lesões foram classificadas em leves, moderadas e intensas de acordo com a historia clinica e o aspecto morfológico dos tecidos. Foram analisados os seguintes parâmetros morfométricos: área dos granulomas, número de larvas/ovos por área e ocorrência de apoptose nos granulomas e em células gigantes. Os resultados obtidos revelaram que o aumento do número de larvas/ovos é diretamente proporcional ao aumento da área e ao agravamento da lesão é inversamente proporcional ao índice apoptótico; as células gigantes eram em maior número em lesões moderadas e, quando presentes, grande parte delas apresentavam núcleos com morfologia de apoptose, sugerindo que estas possam ter um tempo de vida curto.

Angiostrongylus vasorum (Baillet, 1866) is a nematode of the Protostrongylidae family that inhabits the right side of the heart and the pulmonar artery of domestic dogs and other Canidea in different continents. Angiostrongylosis induces granuloma formation with variable volume and composition in different phases in lungs and in other organs. Lung fragments embedded in wax obtained from 12 mongrel dogs experimentally infected with larvae of A. vasorum were sectioned and stained with Hematoxiline Eosine and analyzed at light microscopy. Lesions were classified in mild, moderate and severe according to clinical history and morphological aspect. The following morphometric parameters were analyzed: granuloma area, number of larvae/eggs per area and apoptosis in granulomas and inside giant cells. Increase of number of larvae/eggs was proportional to increase in area and in intensity of the inflammatory reaction and to decrease in apoptosis. Giant cells were more frequent in moderated lesions and, when visible, most presented condensed or fragmented nuclei with evidence of apoptosis. Apoptosis were less frequent in severe lesions, when granulomas were the largest. It is possible that giant cells have a short life in angiostrongylosis.