Parasitization protection

Knox, D.P., Smith, S.K. and Smith, W.D. (1999) Immunization with an affinity purified protein extract from the adult parasite protects lambs against Haemonchus contortus. Parasite Immunology 21, 201-210. 

The function of the essential oil in the plant is not fully understood. Microscopic examination of plant parts that contain the oil sacs readily shows their presence. The odors of flowers are said to act as attractants for insects involved in pollination and thus may aid in preservation and natural selection. Essential oils are almost always bacteriostats and often bacteriocides. Many components of essential oils are chemically active and thus could participate readily in metaboHc reactions. They are sources of plant metaboHc energy, although some chemists have referred to them as waste products of plant metaboHsm. Exudates, which contain essential oils, eg, balsams and resins, act as protective seals against disease or parasites, prevent loss of sap, and are formed readily when the tree tmnks are damaged. 

One of the early vaccine candidates was directed against sporo2oites, the form of the parasites that is first injected into the host by a mosquito. With recent development of recombinant techniques, several circumsporo2oite proteins or its related peptides were proposed as the vaccine candidates. Clinical trials have been carried out. The vaccines were immunogenic, but did not provide sufficient protective efficacy (90,91). 

It provides complete protection for operating personnel troni high touch or step voltages (for details on contact voltages, see Section 22.9) across the enclosure and the metallic structures caused by parasitic (electromagnetic) currents. 

Although acquired immunity to some parasitic diseases may lower the level of infection, absolute immunity as seen in bacterial and viral infections is seldom seen in parasitic diseases. Since parasitic infections produce a wide variety of antigens because of the many life cycle phases, it is more difficult to identify a constant antigenic protein against which specific antibodies are protective. However, malaria remains a likely candidate for a vaccine and there are ongoing studies to develop one. 

Species targeted by pesticides usually make up only several tenths of a percent of the total number of species in an agricultural environment. Natural enemies and parasites usually decrease a species mass reproduction reliably. Destroying, or sharply decreasing the number of, such enemies through pesticide use often leads to a population explosion in the suppressed species chemical protection thus creates a greater threat to the protected cultivars [1]. 

Sherman, I. W. Malaria Parasite Biology, Pathogenesis, and Protection. Washington, DC ASM Press, 1988. 

Parasites have often developed unique ways of protection from the defense mechanisms of the host. 

Parasitism by T. spiralis has been a subject of scientific interest for over 150 years. Recently, considerable attention has been paid to the parasite by immunologists interested in immunity to nematodes in general, and mucosal immunity in particular. It has been shown that glycan-specific antibodies are highly effective mediators of host defence against intestinal 7. spiralis infection. Protective monoclonal antibodies have been used to elucidate mechanisms of worm expulsion, as well as to identify molecules that the parasite uses to create its niche. In the future, detailed characterization of these molecules and their functions should afford additional insights into parasitism by Trichinella spiralis, and possibly also by other types of pathogen. 

McVay, C.S., Tsung, A. and Appleton, J.A. (1998) Participation of parasite surface glycoproteins in antibody-mediated protection of epithelial cells against TrichineUa spiralis. Infection and Immunity 66, 1941-1945. 

The newly synthesized cuticle is highly folded and convoluted and thus allows rapid growth after the moult. Certain stages of some parasitic nematodes retain the old cuticle as a protective sheath. 

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