Oncosphere


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Oncosphere

 

one of the larval stages of most tapeworms. The body is spherical with three pairs of chitinous hooks; hence, an oncosphere is often called a hexacanth—literally, a six-hooked embryo. The oncosphere develops within an egg inside the worm’s uterus. The egg then leaves the body of the host in the host’s feces. The oncosphere continues to develop in water Or in the body of an intermediate host.

References in periodicals archive ?
After ingestion, the coracidium loses its ciliature and penetrates the gut into the body cavity where is develops from an oncosphere into a plerocercoid (previously also called procercoid, see article for terminology of cestode larvae 23).
(5,8,10) The eggs are round to oval in shape, measure an average of 25-40 [micro]m in diameter, and contain an oncosphere with 6 hooklets.
multilocularis are sensitive to environmental factors: elevated temperature and desiccation can effectively reduce oncosphere infectivity (Veit et al., 1995).
The egg hatches in the small intestine and releases an oncosphere. Oncospheres penetrate the intestinal wall and are carried in blood or lymph to various internal organs.
(14) Some cysticercus antigens can react with anti-sera against T solium adult and oncosphere, indicating that they also have common antigens.
* The eggs release the oncosphere (immature larvae) in the animal's intestine.
Humans are accidental hosts and get infected by ingestion of embiyonated eggs, which then hatches in the small intestine and releases an oncosphere that moves to the circulatory system by penetrating small intestine wall and gets lodged in different organs, in particular liver and lungs.
Following ingestion by a human or ungulate intermediate host (sheep, goats, pigs, cattle, horses, and camels), an oncosphere larva is released from the egg.
After the entry of embryos (oncospheres) into the blood stream, the oncosphere can invade various organs and develop into a Hydatid Cyst.
The oncosphere embryos emerge from the eggs, penetrate the intestinal wall, and are disseminated by the bloodstream to various tissues where the larval stage, or cysticercus, develops.
Echinococcus granulosus: antigenic proteins in oncospheres and on the surface of protoscoleces identified by serum antibodies from infected dogs.