stage-specifci developmental forms of lesihmania major promastigotes were grown in vitro. procyclic and metacyclic promastigotes were cultured and separated by peanut agglutinin. the axenic amastigote form were prepared by culturing the promastigotes in acidic medium at 35c.these three forms of parasites were used as antigens to study cytokine production in whole blood culture of healthy indivi...

Serial passage of axenically-cultured Leishmania chagasi promastigotes results in a progressive diminution in resistance to complement mediated lysis (CML), whereas high CML resistance is seen in infectious metacyclic promastigotes from the sandfly vector as well as metacyclic-like promastigotes within low passage cultures at stationary growth phase. As previously reported [94], in a screen see...

A modified infection and maintenance procedure for the cyclical transmission of T. (T.) brucei in Glossina m. morsitans is described which produced high mature infection rates in the flies. Freshly extruded metacyclic forms and bloodstream forms were serologically typed, using the indirect fluorescent antibody test (IFAT) and the neutralization infectivity test (NIT). Metacyclic forms of a cert...

Penetration of Trypanosoma cruzi into mammalian cells depends on the activation of the parasite's protein tyrosine kinase and on the increase in cytosolic Ca2+ concentration. We used metacyclic trypomastigotes, the T. cruzi developmental forms that initiate infection in mammalian hosts, to investigate the association of these two events and to identify the various components of the parasite sig...

To identify parameters of Leishmania infection within a population of infected sand flies that reliably predict subsequent transmission to the mammalian host, we sampled groups of infected flies and compared infection intensity and degree of metacyclogenesis with the frequency of transmission. The percentage of parasites within the midgut that were metacyclic promastigotes had the highest corre...