Agent parasites

Trichinosis. Trichinosis is caused by parasitic nematode Trichinella spiralis that locali2es in the muscles of pigs (see Antiparasitic agents). People... 

The principal OTC pharmaceutical products include cold remedies, vitamins and mineral preparations, antacids, analgesics, topical antibiotics, antiftingals and antiseptics, and laxatives. Others include suntan products, ophthalmic solutions, hemorrhoidal products, sleep aids, and dermatological products for treatment of acne, dandmff, insect parasites, bums, dry skin, warts, and foot care products (11). More recent prescription-to-OTC switches have included hydrocortisone, antihistamine and decongestant products, antiftingal agents, and, as of 1995, several histamine H2-receptor antagonists. 

Sahcyhc acid USP, EP, and other pharmacopeia grades are used medically as antiseptic, disinfectant, antifungal, and keratolytic agents. Sahcyhc acid is formulated in lotion or ointment formulations for the treatment of dandmff, eczema, psoriasis, and various parasitic skin diseases. Because the keratolytic property of this aromatic acid has use in the safe removal of dead skin cells from the surface of healthy skin, the acid is used in concentrated sahcyhc acid solutions or suspensions to remove warts and corns. In more dilute form, sahcyhc acid preparations have found use in dandmff and eczema treatment. Sahcyhc acid has been considered and found effective by the Advisory Committees to the FDA in various over-the-counter (OTC) dmg regulated uses. Among these are acne products, dermatitis, dry skin, dandmff and psoriasis products, and foot care products (24). 

Parasiticides can be roughly divided according to parasites, host species, or chemical classification (see Antiparasitic agents—anthelmintics Antiparasitic AGENTS—ANTiPROTOZOALs). By any classification, these are ubiquitous in the management and control of parasites of both companion and food-producing animals (2,3). 

Mjcoplasmas rickettsiae chlamjdia, and protozoan parasites are also, in general, susceptible to tetracyclines (88—90) (see also Antiparasitic agents). 

In 1912, however, (201) it was discovered that espundia (American mucocutaneous leishmaniasis) can be cured by tartar emetic. It was soon learned that kala-a2ar (visceral leishmaniasis) and oriental sore (a cutaneous form of the disease occurring in the Middle East) also respond to antimonial therapy, especially when compounds of pentavalent antimony are employed. Treatment of leishmaniasis with the latter type of antimonials is safe and effective in over 90% of the cases (202). In 1918, it was demonstrated that tartar emetic is of value in the treatment of schistosomiasis (203). Pentavalent antimonials proved to be less effective. The introduction of antimony compounds for the treatment of parasitic diseases is undoubtedly one of the important milestones in the history of therapeutics (see Antiparasitic agents). 

Water Treatment Compounds. Like the disinfecting agents, several water treatment compounds are used in aquaculture. Of particular interest is potassium permanganate which is exempted from registration by EPA when used as an oxidizer or detoxifier and can control certain parasites, external bacteria, and possibly fungi (9). 

Copper has been employed as a bactericide, moUuscicide, and fungicide for a long time and is of importance in the control of schistosomiasis (see also Antiparasitic AGENTS, ANTHELMINTICS FUNGICIDES, AGRICULTURAL). Addition of copper to lake water acts as an efficient deterrent to transmittal of the disease by eliminating snails that act as hosts for the responsible parasite. Copper is commonly utilized at ca 0.1 mg/L as an algicide. In fresh water, acute toxicosis in fish is unusual if the copper concentration is below 0.025 mg/L (70) (see Poisons, economic). 

Antihelmintic (Anthelmintic). An agent that is useful in the control of parasitic worms. 

A number of muscle relaxants are useful anthelmintic agents. They cause the parasites to relax their attachment to t he gut wall so that they can be eliminated. One such agent s carbantel 9), Its synthesis follows the classic pattern of r eaction of 4-chlorophenyl isocyanate with ji -amylamidine. ... 

The antibiotic agents may destroy or prevent the germs or parasites, without creating any injury to the host cell, or with only minimum toxicity to the host. 

The chemical agents should contact the parasite by prevention, or diffusion through the cells and tissues of the host at suitable doses and effective concentrations. 

Antiprotozoal Drugs. Figure 5 Artemisinin combination therapy (ACT) Adding a 3-days artesunate course to mefloquine cleats the parasitaemia much more rapidly (A — A). The remaining parasites are exposed to higher mefloquine levels in ACT (B) compared to mefloquine monotherapy (B (with permission White, 1997 Antimicrob Agents Chemother 41 1413-1422). 

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. 

Malaria remains a major public health problem in many parts of the world, including Southeast Asia, sub-Saharan Africa and Latin America where an estimated 300-500 million people are infected. 1-3 million die of malaria every year. The etiologic agents of malaria are protozoan parasites of the genus Plasmodium. Of the four pathogens that can cause malaria in humans (Plasmodium falciparum, P. vivax, P. ovale,... 

Biological and Natural Controls. Parasites and predators are effective in limiting the numbers of pest Insects and plant pathogens both in nature and for crops (35). This basic fact led to the development of biological controls. For example, the vedalia beetle, which was Introduced for control of cottony cushion scale on citrus in California, has provided continuous effective control of this pest for many decades. Worldwide only approximately 1% of the pests have been effectively controlled by Introduced biological control agents (43). 

However, not all natural enemies are fully effective. For example, the gypsy moth has approximately 100 parasites and predators attacking it but the pest reaches outbreak levels periodically (35). Nearly 40 biological control agents were introduced from Europe and Asia to control the moth and 11 of these became established (44). Yet not one of the 11 blocontrol agents is providing fully effective control, although each contributes to some limitation of this pest. 

IFNs are natural glycoproteins produced by the cells of most vertebrates in response to the challenge by foreign agents, such as infectious organisms (viruses, bacteria, fungi, and parasites), and by tumor cells. IFNs can be produced by cells of the innate and adaptive immune systems and by non-immune cells such as fibroblasts and epithelial cells. 

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