Blood worm

The annelids include the bristle worms and blood worms in which toxicity is associated with bristle-like setae and/or biting jaws. In the order Polychaetae, toxicity is usually found in three genera (Chloeia, Eurythoe, Hemodice). The platyhelminthes are not associated with many cases of human toxicity. The only class of platyhelminthes in which toxicity can readily be found is in the Turbellaria. In the Rhynchocaela (ribbon worms), toxic species include Lineus sp. Some platyhelminthes (e.g., Planocera multitenta) have been found to contain tetrodotoxin 16). 

FIGURE 2 A one-dimensional NMR spectrum of a globin from a marine blood worm. This protein and sperm whale myoglobin are very close structural analogs, belonging to the same protein structural family and sharing an oxygen-transport function. 

Whipworm (Trichuris trichiurd) adult females are 5 cm long. These worms thread their entire body into the epithelium of the colon, where they feed on tissue juice and small amounts of blood. Infections of several hundred worms may cause irritation and inflammation of the mucosa, with abdominal pain, diarrhea, and gas. Eggs are discharged and passed into the feces. Infections result from the swallowing of eggs that are obtained directly from contaminated soil. Untreated adult worms Hve for years. 

The filariform larva found in moist soils may be either ingested or penetrate the skin of its host. It is then carried through the circulatory system to the lungs and migrates up the respiratory tree into the digestive tract. The worms feed on intestinal tissue and blood. Some worms may persist in humans as long as nine years. Infestations cause cutaneous reactions, pulmonary lesions, intestinal ulcerations, and anemia. 

Diethylcarbama2iae (9) (orally administered) has been successful for decades in the treatment of filariasis, eg, elephantiasis (32). It kills microfilariae in the blood of the filarial worms Wuchereria bancrofti Brugia malaji and lj)a loa. 

Worms - There are three types of worms found in water. For the most part, they dwell in the bed of the material at the bottom of lakes and streams. There they do important work as scavengers. The rotifiers are the only organisms in this category at or near the surfaee. They live primarily in stagnant fresh water. The eggs and larvae of various intestinal worms found in man and warm-blooded animals pollute the water at times. They do not generally cause widespread infection for several reasons. They are relatively few in number and are so large they can be filtered out of water with comparative ease. 

Specimens should be examined grossly to determine the consistency (hard, formed, loose, or watery), color, and presence of gross abnormalities such as worms, mucus, pus, or blood. It may be profitable to examine flecks of mucus, pus, or blood for parasites. If adult worms or portions of tapeworms are sought, the feces may be carefully washed through a screen. (Small worms may be difficult to see if gauze is used.) The identification characteristics of adult worms are not discussed in this chapter, so parasitology books should be consulted. 

Vaccination of lambs with a contortin-enriched preparation gave a mean reduction in worm burdens of 78% (Table 13.1) (Munn et al., 1987). This result was particularly significant because it showed that proteins expressed on the surface of the gut, albeit from a blood-feeding nematode, could induce high levels of protective immunity when used as an immunogen. These proteins are not normally accessible to the host immune system during the course of infection they are termed hidden or concealed antigens and the immunity conferred by them is described as artificial immunity. 

Internal structure of the tube worm Riftia pachyptila. (a) Oxygen, sulfide, and carbon dioxide are absorbed through the plume filaments and transported In the blood to the cells of the trophosome. (b) The chemicals are absorbed into these cells, which contain dense colonies of sulfur bacteria, where they are converted to organic compounds and (c) passed back into the circulatory system to act as an energy source for the worms. Source-. From Childress, J. J., et al. (1987). Scientific American, 256, 114-121. 

I began hearing voices... I also saw... bugs, worms, one snake, a monkey and numerous rats... I thought my skin was yellow... I attempted to wipe the blood away [on nearby subject] but there was no blood. ... 

One of the reasons there are more types of cells than soluble factors is that they must have the capacity to distinguish between those pathogens that are present in the extracellular fluids (e.g. blood and lymph), those that are present within host cells (e.g. vimses, some bacteria) and those that are too large to be phagocytosed (some parasites e.g. helminths, worms). The mechanisms of killing, therefore, must be sufficiently flexible to deal with all of these pathogens. 

Albendazole selectively blocks glucose uptake and depletes glycogen stores. ATP formation is thus inhibited. It should be administered on an empty stomach for intraluminal parasites and with a fatty meal for tissue parasites. It is metabolized to an active sulfoxide metabolite resulting in very low Albendazole blood levels. Albendazole sulfoxide is excreted in the urine with an elimination half-life of about 8 h. Used for 1-3 days in doses recommended for intestinal worms the incidence of adverse effects is similar in treatment and control groups. Hepato-toxicity may occur, especially after the higher doses that are needed for hydatid disease. Also alopecia has been reported. 

The filarial worms differ from other nematodes in that they are threadlike and are found in blood and tissue. The infective larvae enter following the bite of an infected arthropod (fly or mosquito). They then enter the lymphatics and lymph nodes. Fever, lymphangitis, and lymphadenitis are associated with the early stage of the disease. Chronic infections may be characterized by elephantiasis as a result of lymphatic obstruction. Some species of filarial worms migrate in the subcutaneous tissues and produce nodules and blindness (onchocerciasis). 

Filariasis. The presence of parasites filariae in the blood and tissues of the body. May be asymptomatic, and living worms cause minimal tissue reaction. Death of the adult worms causes marked inflammation and lymphatic obstruction. 

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