Host-mediated responses and parasite density-dependent processes can have a major influence on the growth and fecundity of parasitic nematodes. However, host characteristics and parasite intensity consistently change during the course of an infection and these could affect worm length and number of eggs in a non-constant way. We used a free-living population of rabbits naturally infected with T...

The separation between open and closed circular DNA in buoyant CsCl gradients containing intercalating dyes depends on the superhelix density of the closed form. These separations are about 1.8 times larger with propidium iodide than with ethidium bromide. The superhelix densities of mitochondrial DNA from HeLa cells and Lytechinus pictus eggs appear to be about two thirds that of mitochondrial...

A laboratory colony of human body lice was experimentally infected by feeding on rabbits made artificially bacteremic with a green fluorescent protein-expressing Bartonella quintana. B. quintana was detected in the gut and feces until death but not in the eggs. The life span of the lice was not modified. The rabbit model should provide valuable clues to the role of lice in the transmission of B...

A significantly higher survival rate was obtained when frozen-thawed morulae were transferred to oviducts of recipients ovulating after donors rather than to those of synchronized or earlier ovulating recipients. The highest proportion of live young, 23%, was obtained after transfer of eggs to recipients ovulating 18 h after donors. The proportion of live young (48%) was significantly increased...

Eosinophils form 50% of cells in the host granulomatous response to Schistosoma mansoni eggs, but their functional role in these granulomas and their relation to egg destruction is unknown. We have studied the course of S. mansoni infection in mice treated with normal rabbit serum (NRS) or depleted of their eosinophils by monospecific anti-eosinophil serum (AES). At 6-wk of infection (after 2 w...

Background Establishment of sand flies laboratory colonies is essential to understand various biological aspects of Phlebotominae sand flies. The aims of the current study were to establish the colony of Phlebotomus sergenti Parrot (1917), the main vector of anthroponotic cutaneous leishmaniasis in old world, and to study biological parameters of this species. Methods The sand flies were rear...

I N the course of an investigation on the uptake of labelled ions by the rabbit embryo and its environment (Lutwak-Mann, Boursnell, & Bennett, 1960), experiments were done on pre-implantation blastocysts obtained from rabbits which had been treated parenterally with certain purine analogues. Histological examination of such blastocysts by the method of Moog & Lutwak-Mann (1958) showed that, as ...