Proteomic analysis of Plasmodium in the mosquito: progress and pitfalls.

Here we discuss proteomic analyses of whole cell preparations of the mosquito stages of malaria parasite development (i.e. gametocytes, microgamete, ookinete, oocyst and sporozoite) of Plasmodium berghei. We also include critiques of the proteomes of two cell fractions from the purified ookinete, namely the micronemes and cell surface. Whereas we summarise key biological interpretations of the data, we also try to identify key methodological constraints we have met, only some of which we were able to resolve. Recognising the need to translate the potential of current genome sequencing into functional understanding, we report our efforts to develop more powerful combinations of methods for the in silico prediction of protein function and location. We have applied this analysis to the proteome of the male gamete, a cell whose very simple structural organisation facilitated interpretation of data. Some of the in silico predictions made have now been supported by ongoing protein tagging and genetic knockout studies. We hope this discussion may assist future studies.

Cellular and molecular interactions between the apicomplexan parasites Plasmodium and Theileria and their host cells.

Apicomplexan parasites of the genera Theileria and Plasmodium have complicated life cycles including infection of a vertebrate intermediate host and an arthropod definitive host. As the Plasmodium parasite progresses through its life cycle, it enters a number of different cell types, both in its mammalian and mosquito hosts. The fate of these cells varies greatly, as do the parasite and host molecules involved in parasite-host interactions. In mammals, Plasmodium parasites infect hepatocytes and erythrocytes whereas Theileria infects ruminant leukocytes and erythrocytes. Survival of Plasmodium-infected hepatocytes and Theileria-infected leukocytes depends on parasite-mediated inhibition of host cell apoptosis but only Theileria-infected cells exhibit a fully transformed phenotype. As the development of both parasites progresses towards the merozoite stage, the parasites no longer promote the survival of the host cell and the infected cell is finally destroyed to release merozoites. In this review we describe similarities and differences of parasite-host cell interactions in Plasmodium-infected hepatocytes and Theileria-infected leukocytes and compare the observed phenotypes to other parasite stages interacting with host cells.

The Performance of an Electrorheological Fluid in Dynamic Squeeze Flow: The Influence of Solid Phase Size.

This paper is concerned with an experimental investigation of a comparison of the rheological performance of an ER fluid, consisting of a carrier with a range of solid phase sizes, in oscillatory squeeze-flow under DC conditions. The fluid is sandwiched between two parallel plane electrodes, the upper one stationary and the lower one oscillating normal to its plane. It is seen that the dynamic performance of the fluid, in terms of the capacity for the transmission of imposed forces across the fluid, is highly dependent on the size of the dispersed solid phase and has an optimum value which is dependent on the mean value of the interelectrode gap. In addition the paper includes some measurements of the current through the fluid which may help to shed some further light on the mechanism of the ER effect. Finally the implications of the results to vibration control are discussed. Copyright 1999 Academic Press.