Plasmodium falciparum is able to sequester from peripheral circulation during infection. The asexual stage parasites sequester by binding to endothelial cell receptors in the microvasculature of various organs. Gametocytes also spend the almost ten days necessary for their maturation sequestered away from the peripheral circulation before they are released in blood mainstream. In contrast to those of asexual parasites, the mechanisms and cellular interactions responsible for immature gametocyte sequestration are largely unexplored, and...

Mosquitoes are progressively becoming resistant to industrial repellents and insecticides. This is the case for pyrethroids used on bednets. Pyrethroids are toxic. Aquatic ecosystems are particularly vulnerable to the impact of permethrin. A fragile balance exists between the quality and quantity of insects and other invertebrates that serve as fish food. The 48-hour LC50 for rainbow trout is 0.0125 mg/L for 24 hours, and 0.0054 mg/L for 48 hours. The 48-hour LC50 in salmon is 0.0018 mg/L. As a group, synthetic pyrethroids were toxic...

Several papers published twenty, even thirty years ago should have attracted more attention. In 1992 it was found that interleukin IL-10, in a dose-dependent manner, inhibits the microbicidal activity of macrophages against intracellular Toxoplasma gondii as well as the extracellular killing of schistosomula of Schistosoma mansoni. This suppression correlates with the inhibition by IL-10 of the production of toxic nitrogen oxide metabolites, an effector mechanism previously implicated in the killing by macrophages of both parasite...

Essential oils of Artemisia plants The essential oils of Artemisia annua have been extensively studied and the major constituents are cineole, camphene, a-pinene, germacrene, caryophyllene, camphor and artemisia ketone. They are present at concentrations of 0.20-0.25% and have shown not only different antimicrobial activities, but also anti-inflammatory and cytotoxic activities1. They are reduced by high drying temperatures of the herb. Artemisia ketone is a major constituent of some cultivars of A. annua. Like other ketones it inhibits...

ARTAVOL from Uganda PGs are important soluble mediators involved in the immune response to invading pathogens and this may explain the strong prophylactic effect of ARTAVOL, a drug developed by Dr Patrick Ogwang from the University of Makerere and the Ministry of Health in Uganda. The powder contains lemongrass (Cymbopogon citratus), avocado (Persea americana) and Artemisia annua. Avocados contain 9% of fatty acids and 71 % of these are monounsaturated. The fatty acid of lemongrass is very rich in linoleic and oleic acid. Linoleic acid...