Sleeping sickness

African sleeping sickness and, 1, 180 as chemotherapeutic agent, 1, i80 veterinary use, 1, 208 Furfuracryluric acid as metabolite of furfural, 1, 245... 

In general As " organic derivatives are more toxic than As derivatives. The use of organoarsenicals in medicine dates from the discovery in 1905 by H. W. Thomas that atoxyl (first made by A. Bechamp in 1863) cured experimental trypanosomiasis (e.g. sleeping sickness). In 1907 P. Erlich and A. Bertheim showed that atoxyl was sodium hydrogen 4-aminophenylarsonate... 

African sleeping sickness is a parasitic disease of increasing importance, with an estimated 300,000-500,000 cases annually. The etiological agents, T. brucei gambiense and T. brucei rhodesiense, are transmitted to humans by the bite of Tsetse flies. 

Nowadays, treatment of African sleeping sickness with the prevailing drugs faces three major problems ... 

Ferguson, MAJ (2000) Glycosylphosphatidylinositol biosynthesis validated as a drug target for African sleeping sickness. Proc Natl Acad Sci USA 97 10673-10675... 

African trypanosomiasis (sleeping sickness) and American trypanosomiasis (Chagas disease) are caused by Trypanosoma brucei and Trypanosoma cruzi, respectively. Sleeping sickness results from being bitten by the insect vector, the tsetse fly. At first there is only local lymphadenitis but about a month later generalized malaise, fever, and systemic disease involving skeletal muscle is seen. 

Heeds indirectly affect the health of man and animals by harboring animals or insects. Control of aquatic weeds is effective for mosquito (Anopheles quadrimaculatus Say) control by eliminating breeding habitats. In control of the tsetse fly (Glossian spp.) (vector of sleeping sickness in Africa), herbicides are involved to reduce growth of the brush so essential to the survival of the fly. 

Diseases which will probably be subject to control by insecticides but have not yet been adequately tested include sandfly fever, dengue, urban yellow fever, bartonellosis, cutaneous leishmaniasis, Chagas disease, filariasis, trench fever, and louse-born relapsing fever. Some of the virus encephalitides. sleeping sickness, and visceral leishmaniasis may also be susceptible of control. 

Many unicellular eukaryotes are free-living cells, but may form huge local communities, which are especially beneficial to the homeostasis of the ocean/atmos-phere carbon cycle, e.g. coccoliths. Many others are not free-living, but are extremely valuable in symbiotic relationship with multi-cellular plants and animals. Unfortunately, some unicellular eukaryotes are the causes of disease, for example Trypanosoma, which are animals and cause sleeping sickness in humans (see Section 8.9 for parallel diseases of plants). These facts are reminders that while we consider that the whole ecosystem works to one general purpose (Section 4.4), this does not exclude the obvious feature that within its overall associations we can see diseases inflicted on one species by another or competition between similar species. Many bacteria are also causes of serious eukaryote diseases. Even so at the end of... 

This compound was found to be effective in treating syphilis and African sleeping sickness, although more effective drugs soon became available. In addition to the name Salvarsan, this compound is listed in the Handbook of Chemistry and Physics as "606" to denote where it fell in the series of compounds tested by Ehrlich and his collaborators. 

The second parasitic disease we want to consider is sleeping sickness, or African trypanosomiasis, as it is also known. Sleeping sickness results from an infection by protozoa called trypanosomes that are closely related to Leishmania, and, like leishmaniasis, sleeping sickness is spread by flies. On a more general level, however, the two diseases seem quite distinct. Leishmaniasis takes several forms, only one of which is fatal, but untreated sleeping sickness invariably leads to death. Leishmaniasis is a menace in much of the... 

Both male and female tsetse live solely on vertebrate blood, and the various species that carry sleeping sickness typically feed not only on humans but also on both domestic and wild animals. Infected flies pass on trypanosomes whenever they take a blood meal, so that the parasites not only move between flies and humans, but also infect a number of other hosts. Infected domestic animals develop nagana, but wild animals may show no sign of illness. They serve instead as healthy animal reservoirs of trypanosomes, permitting tsetse flies to pick up the parasites at any time without necessarily feeding on infected humans or domestic animals. For this reason and also because available drug therapies have proved no more practical here than for leishmaniasis, control of trypanosomiasis has long emphasized eradication of tsetse flies. 

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