RESUMO
Atomic force microscopy (AFM) has been employed to examine morphological and topographical changes caused by human immunodeficiency virus (HIV) and the effects of highly active antiretroviral therapy (HAART) on spermatozoon of HIV infected patients. This powerful technique has allowed us to visualize morphological alterations present in the spermatozoa of patients either with or without treatment. In addition to this, even the minute details, such as viral particles, located on the membrane of the spermatozoa, and the merging of such particles on the surface of the spermatozoa were detected with precision. The most important aspect is that AFM, unlike electron microscopy, permits to image virions in their nearly natural environment. Excess of damage of spermatozoon is due to the chemicals involved in HAART rather than the damage made by virus.
Assuntos
Terapia Antirretroviral de Alta Atividade/efeitos adversos , Infecções por HIV/tratamento farmacológico , HIV/isolamento & purificação , Microscopia de Força Atômica/métodos , Cabeça do Espermatozoide/efeitos dos fármacos , Cauda do Espermatozoide/efeitos dos fármacos , HIV/ultraestrutura , Infecções por HIV/patologia , Humanos , Masculino , Cabeça do Espermatozoide/ultraestrutura , Cabeça do Espermatozoide/virologia , Motilidade dos Espermatozoides/efeitos dos fármacos , Cauda do Espermatozoide/ultraestrutura , Cauda do Espermatozoide/virologia , Vírion/isolamento & purificação , Vírion/ultraestruturaRESUMO
A recently developed technique, namely multiple beam interference microscopy, has been applied to investigate the morphology of the parasite Toxoplasma gondii for the first time. The interference pattern obtained from the multiple internal reflection of a T. gondii, sandwiched between a glass plate and a cover plate, was focused on the objective of a conventional microscope. Because of the enhance contrast, several details of sub cellular structure and separating compartments are clearly visible. Details reveal the presence of a nucleus, lipid body, dense granule, rhoptry and amylopectin. The wall thickness of the membrane of the lipid body and the amylopectin is of the order of 0.02 microm and can be clearly distinguished with the help of the present technique. The same parasite has also been examined with the help of atomic force microscopy, and because of its thick membrane, the inner structural details were not observed at all. Sub cellular details of T. gondii observed with the present technique have been reported earlier only by low amplification transmission electron microscopy and not by any optical microscopic technique.