Trypanosoma cruzi necrotizing meningoencephalitis in a Venezuelan HIV⁺-AIDS patient: pathological diagnosis confirmed by PCR using formalin-fixed- and paraffin-embedded-tissues.

Coinfections with human immunodeficiency virus (HIV) and infectious agents have been recognized since the early 90s. In the central nervous system (CNS) of HIV(+) patients, parasitic protozoans like Toxoplasma gondii have been described as responsible for the space occupying lesions (SOL) developed. However, the involvement of Trypanosoma cruzi is also described but appears to be less frequent in acquired immunodeficiency syndrome (AIDS) and transplant recipients, associated with necrotizing myocarditis and neurological symptoms related to the occurrence of necrotizing pseudotumoral encephalitis (NPE) and meningoencephalitis (NME).

Effects of herbicide on the kidneys of two Venezuelan cultured fish: Caquetaia kraussii and Colossoma macropomum (Pisces: Ciclidae and Characeae).

The use of chemical pesticides and herbicides has increased environmental pollution and affected ichthyofauna in the watersheds where they are used. We studied the effect of an herbicide, triazine, on the kidneys of two species (Caquetaia kraussii and Colossomna macropomum) widely found in Caribbean and South American rivers. In Venezuela, these species are abundant and have a high aquaculture potential because they may be cultured and reproduced in captivity.

[Ultra structure of retinopathy induced by hyperoxia in developing rats].

In order to evaluate the effect of postnatal hyperoxia on retinal structure, newborn rats were exposed to different oxygenation intervals (80 +/- 1%) with three interruptions of 21% (30 min each). Four groups of rats were exposed from birth to the 6th, 9th, 12th and 14th postnatal day, respectively and another group was placed under normoxia. After this period all oxygenated groups and the controls remained under normoxia until they were 30 days old for the structural analysis of retina.

Skeletal muscle ultrastructural pathology in mice infected with Trypanosoma evansi.

An ultrastructural study of skeletal muscle alterations wascarried out in mice experimentally infected with Trypanosoma evansi. Manifested anomalies were found, in both muscle fibre and microvasculature. Muscle fibre changes included atrophy, autophagic vacuoles formation, mitochondrial degeneration, nuclei pyknosis and segmental necrosis.