Background Background: Mammalian spermatogenesis is regulated through paracrine and endocrine activity, specific cell signaling, and local control mechanisms. These highly specific signaling interactions are effectively absent upon placing testicular cells into two-dimensional primary culture. The specific changes that occur between key cell types and involved spermatogenesis signaling pathways...

background: based on recent studies, there are controversial reports on the ca-pacity of tissue cyst forming of toxoplasma gondii rh strain. in this study, the capac-ity was evaluated by in vivo and in vitro experiments. methods : rh strain was subcutaneously inoculated to ten wistar rats. after one month, their blood, brain, tongue and diaphragm were collected and evaluated by mat, pcr, pathol...

in recent years, it has become evident that it is necessary to systematically and accurately define particle characteristics in order to understand the potential toxicity of nanoparticles to biological systems. the properties that need to be emphasized are size, shape, dispersion, doping, aggregation, functionalization, physical and chemical properties, surface area, and surface chemistry. rout...

Mycobacteria, especially M. tuberculosis, have remained a worldwide dominant cause for human morbidity (~10 million annual cases) and mortality (3 million deaths annually) since ancient times. An estimated one-third of living humans are latently infected with M. tuberculosis. Despite this, there have been no new drugs specifically developed against mycobacteria since the 1960s. Because of a slo...

An attempt has been made to replicate an earlier finding that type A botulinum toxin can inhibit the in vitro activity of acetylcholinesterase. Two methods of enzyme assay were employed, but with neither technique were we able to reproduce the finding of in vitro enzyme inhibition. In fact, an examination of the data from the previous report leads us to question the possibility of the observati...

The protozoan parasite Leishmania donovani is the causative agent of visceral leishmaniasis, a disease potentially fatal if not treated. Current available treatments have major limitations, and new and safer drugs are urgently needed. In recent years, advances in high-throughput screening technologies have enabled the screening of millions of compounds to identify new antileishmanial agents. Ho...