Parasitic larvae

Kennedy, M.K., Maizels, R.M., Meghji, M., Young, L., Qureshi, F. and Smith, H.V. (1987) Species-specific and common epitopes on the secreted and surface antigens of Toxocara cati and Toxocara canis infective larvae. Parasite Immunology 9, 407-420. 

Maizels, R.M., de Savigny, D. and Ogilvie, B.M. (1984) Characterization of surface and excretory-secretory antigens of Toxocara canis infective larvae. Parasite Immunology 6, 23-37. 

Limonene inhibiting pine larva parasites feeding (Diprian pini and Dendrolymus pini) [103]. The (+)-3-thujone and (-)-3-isothujone, the main components of Thuja plicata leaves, inhibit the feeding of Pissodes on needle trees [102]. Enzymatic mechanism explaining the olfactory processes are the reasons for eliciting responses between the optical isomers and the receptors. 

Jenkins SJ, Hewitson JP, Jenkins GR. Modulation of the host s immune response by schistosome larvae. Parasite Immunol 2005 27 385-393. 

Parasitism has also been reported to cause the synthesis of proteins that were not present in unparasitized hosts (18. 37. 38). Two predominant and one minor proteins were found in the hemolymph of M. sexta larvae parasitized by larval parasitoid, C. congregata. These proteins were apparently produced by the host during the final... 

Both the adult and the larval cysticerci (bladderworm) of Taenia solium (pork tapeworm) are able to Hve in humans the parasite is found sporadically in uncooked pork. In the stomach, the larva is digested out of the pork flesh it then grows and attaches to the wall of the small intestine. Maturity is reached in 5—12 weeks. The adult is 5 m long, and untreated adult worms may survive for 25 years. 

Another potential application of radioactive species is in food preservation (Figure 19.2, p. 518). It is well known that gamma rays can kill insects, larvae, and parasites such as... 

Albendazole (Albenza) interferes wiHi Hie synHiesis of the parasite s microtubules, resulting in deatii of susceptible larva This drug is used to treat larval forms of pork tapeworm and to treat liver, lung, and peritoneum disease caused by the dog tapeworm. 

The Great Lakes have suffered the invasion of numerous exotic species of which the smelt, alewife and sea lamprey are probably the best known. More recently, two more species have entered the lakes probably via ballast water from foreign ships. The ruffe (Gymnocephalus cemuus) a small percid, feeds on the eggs and larvae of other percids and whitefish. The ruffe is currently considered to be a threat to Lake Superior s 5- 10 million whitefish fishery. The zebra mussel (Dreissena polymorpha) was discovered in Lake St. Clair in 1985 (31). It has subsequently been discovered at locations throughout the Great Lakes and is of major concern not only environmentally but economically. It has already colonized numerous industrial and domestic water intakes in sufficient numbers to entirely block water flow and is also an intermediate host to parasites which eventually invade fish. 

Newton, J.E., Adams, C.C., Bairden, K., Coop, R.L. Jackson, F. (in press) The effect of grazing by poultry on the number of sheep parasitic larvae found on organic grassland. The Veterinary Record. 

In some helminth infections, a migration through various body tissues is essential for maturation, as in ascarasis or schistosomiasis, whereas in other infections, the larva leaves the egg and simply matures in the intestinal tract, as in trichuriasis and enterobiasis. Host tissues involved vary depending upon the parasite. In severely immunocompromised patients, sites may be involved that are not involved in normal hosts. 

Identification may be by gross examination for adult helminths or, more commonly, by microscopic examination for protozoa, helminth eggs, and larvae. The diagnostic forms of some parasites, such as the eggs of Ascaris spp., are present on a regular basis. Other forms, such as malaria parasites, Taenia eggs, or Giardia cysts, vary from day to day. 

The direct wet mount made from unconcentrated fresh feces is most useful for the detection of the motile trophozoites of intestinal protozoa and the motile larvae of Strongyloides spp. It is also useful for the detection of protozoan cysts and helminth eggs. For fixed feces, the direct wet mount may allow the detection of parasites which do not concentrate well. This method is also useful for the examination of specific portions of feces, such as flecks of blood or mucus. 

The Baermann concentration technique has greater sensitivity for the detection of strongyloides larvae than do the standard concentration techniques described above. This technique is useful clinically for the diagnosis and monitoring of therapy of strongyloides infections, and it is useful epidemiologically for the examination of soil for the larvae of nematode parasites. 

In an ideal stain, the cytoplasm of cysts and trophozoites is blue-green tinged with purple. Entamoeba coli cyst cytoplasm is often more purple than that of other species. Nuclear chromatin, chromatoid bodies, erythrocytes, and bacteria stain red or purplish red. Other ingested particles such as yeasts often stain green. Parasite eggs and larvae usually stain red. Inflammatory cells and tissue cells stain in a fashion similar to that of protozoa. Color reactions may vary from the above. 

Read, A.F. and Skorping, A. (1995b) The evolution of tissue migration by parasitic nematode larvae. Parasitology 111, 359-371. 

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