Translate this page to:
Choose Language…
In JoVE (1)
Other Publications (2)
Articles by Mariana Acquarone in JoVE
JoVE General
Analysis of Pluripotent Stem Cells by using Cryosections of Embryoid Bodies
Pluripotent stem cells growing in suspension differentiate into embryoid bodies (EBs). Here we demonstrate how to obtain high quality EB cryosections useful for studying cellular and molecular aspects of embryogenesis, while preserving their organization as aggregates.
Other articles by Mariana Acquarone on PubMed
Anionic Sites on Toxoplasma Gondii Tissue Cyst Wall: Expression, Uptake and Characterization
Toxoplasmosis, caused by Toxoplasma gondii, is an important parasitic disease worldwide, which causes widespread human and animal diseases. The need for new therapeutic agents along with the biology of these parasites has fueled a keen interest in the understanding of the nutrients acquisition by these parasites. Studies on the characterization of the T. gondii cyst wall as well as the contribution of the host cell to this formation have been little explored. The aim of this paper was to investigate the electric surface charge of the T. gondii tissue cysts by ultrastructural cytochemistry, through polycationic markers, employing ruthenium red (RR) and cationized ferritin (CF). Glycosaminoglycans revealed by RR were localized on the cyst wall as a homogeneous granular layer electrondense, all over its surface. The incubation of living tissue cysts with CF for 20 min at 4 degrees C followed by the increase of temperature to 37 degrees C indicated that T. gondii cyst wall is negatively charged and that occurs an incorporation of anionic sites by the cyst wall, through vesicles and tubules, and their posterior location in the cyst matrix. So, as to identify which group of molecules produces negative charge in the cyst wall, we used enzymes for cleavage on different types of molecules, demonstrating that the negative charge in the cyst wall is mainly produced by phospholipids. Our results, described in this work show, for the first time, the negativities of the cyst wall, the incorporation and the traffic of intracellular surface molecules by T. gondii cyst wall. Our model of study can give an important contribution to the knowledge of the biology and the processes involved in nutrients acquisition by bradyzoites living inside the cysts and, and also be applied as a target for the direct action of drugs against the cyst.
Acquired Infection with Toxoplasma Gondii in Adult Mice Results in Sensorimotor Deficits but Normal Cognitive Behavior Despite Widespread Brain Pathology
Toxoplasma gondii is a ubiquitous intracellular parasite which chronically infects 30-50% of the human population. While acquired infection is primarily asymptomatic several studies have suggested that such infections may contribute to neurological and psychiatric symptoms. Previous studies in rodents have demonstrated that T. gondii infection does not just kill its host, but alters the behavioral repertoire of an infected animal, making it more likely that predation with occur completing the parasite life cycle. The aim of the present study was to evaluate the behavioral changes in C57BL/6 mice chronically infected with the avirulent T. gondii (ME49, a Type II strain), in a comprehensive test battery. Infected mice demonstrated profound and widespread brain pathology, motor coordination and sensory deficits. In contrast, cognitive function, anxiety levels, social behavior and the motivation to explore novel objects were normal. The observed changes in behavior did not represent "gross" brain damage or dysfunction and were not due to targeted destruction of specific areas of the brain. Such changes point out the subtle interaction of this parasite with its intermediate hosts and are consistent with ideas about increased predation being an outcome of infection.
