Nematode

Representatives of this phylum have been used extensively as indicators of stressed environments. Population stracture and species diversity of free-living nematodes inhabiting sediments in the New York Bight were moderately influenced by the heavy metal content of sands. In medium-grained sands, species diversity was inversely correlated with increased concentrations of chromium and other metals. Sands containing 3.0-21.5 mg Cr/kg were also marked by high relative abundances of one or two nematode species the tolerance of these species to chromium stress probably exceeded that of the normal nematode inhabitants of such sediments. 

The nematode species of most interest for the control of crop insect pests are from the genera Steinernema and Heterorhabditis, both characterised by their association with bacteria from the genera Xenorhabdus and Photorhabdus. These nematodes invade the insect and then release their symbiotic bacteria into the insect s haemocoel. The nematodes release metabolites that repress the immune system of the insect, allowing the bacteria to develop. The bacteria then release toxins that kill the insect within two to three days and also produce antibiotics that prevent the invasion of the dead insect by other bacteria. These bacteria then invade the entire insect cadaver and the nematodes subsequently begin to consume the bacteria. 

To date these nematodes have been shown to be effective at controlling soil-inhabiting insects but their commercial exploitation has been hampered by the cost of their production. 

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Nematode infections Nematode resistance Nematodes Nemaworm capsules Nembutal (sodium)... 

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

Pests iaclude rats, a severe problem ia some areas, wild animals, nematodes, and a number of iasects. The most severe iasect pests are the various types of borers, ie, the sugarcane borer, Diatrea saccharalis (F.) and the eldana borer, Pldana saccharina which cause damage first by boring iato the cane stalk, then by providing entry poiats for other diseases, and finally by reduciag cane and juice quality. 

Levamisole. The racemic mixture of the d and / isomers of tetramisole [6649-23-6] was first described in 1966. It is used as an anthelmintic against a wide variety of nematodes, including lungworms, of mminants, swine, horses, dogs, and poultry. Anthelmintic activity resides in the /-isomer, levamisole [14769-73-4], the form used. 

Phenothia2ine [58-37-7] (thiodiphenylamine) is used orally against intestinal nematodes of mminants and horses. It is used with occasional gastrointestinal upset, hemolytic processes, and photosensitivity. It is used routinely at low concentrations on horse farms to suppress the egg production of intestinal parasites (strongyles) and thus limit pasture contamination and transmission (4). 

Many parasitic worms cause systemic infections outside the gastrointestinal tract. These include Strong loides stercoralis (threadworm), Trichinella spiralis Dracunculus medinensis and the several species of nematodes that cause filariasis (Mansonellaperstans and Onchocerca volvulus). 

Ivermectin is active against two significant phyla of animal parasite the Nemathehninthes or nematodes (roundworms) and the Arthropoda (insects, ticks, and mites). Ivermectin is inactive against platyhehninthes (flukes and tapeworms). 

Ivermectin has an extremely broad spectmm of antinematodal activity in a variety of domestic animals. Indeed, among the many nematodes against which it has been tested, none has been found that is not affected by ivermectin during at least one stage of the life cycle. In all but a few instances the dmg is highly active against both immature and mature worms (19). 

Ivermectin is used in cattle, sheep and horses at 0.2 mg/kg swine at 0.3 mg/kg dogs at 0.006 mg/kg and man at 0.05 —0.2 mg/kg. It is effective against parasitic nematodes, gmbs, Hce, mites, ticks, and bots. Ivermectin is not active against tapeworms, flatworms, bacteria, or fungi. 

The primary use for methyl bromide is in the extermination of insect and rodent pests. Methyl bromide is used in space and stmctural fumigation except in California. The material is suitable for the fumigation of food commodities such as dried fmits, grain, flour, and nuts, and the faciHties in which these foods are processed or stored, as weU as for tobacco and many kinds of nursery stock. The usual dosage is 2—4 kg/28 m for 12—24 h. In soil fumigation methyl bromide controls weed seeds, nematodes, wireworms, and soil fungi. The usual dosage is 0.5—1 kg/9 m for 24 h at 16°C and above (82). 

Kenaf is a grass fiber crop that has been proposed as a papermaking source. It is an aimual crop and can be grown in many parts of the country. There have been agronomic problems with kenaf, primarily its vulnerabiUty to nematode pests. Another problem is that kenaf is harvested once a year and must then be stored, usually as silage. There is some loss of the fiber in storage. 

Insects, crustaceans, platehelminthes, nematodes and annelids use homoses-quiterpenoid epoxides (juvenile hormones) and ecdysteroids (ecdysone, 20-... 

AE Sluder, SW Mathews, D Hough, VP Ym, CV Mama. The nuclear receptor superfamily has undergone extensive proliferation and diversification in nematodes. Genome Res 9 103-120, 1999. 

Caenorhabditis elegans (simple animal nematode worm) 100 (1998 )... 

Antinematodal. An anthelmintic effective against round worms (nematodes). 

Cholinergic neurotransmission ChEs terminate cholinergic transmission in the central nervous system (CNS), in NMJs and in the autonomic system (the parasympathetic system, somatic motor nerves and pre-ganglionic sympathetic nerves). A few sensory cells and the NMJ in nematodes also include ChEs. 

Levamisole Synthetic imidazothiazole nematode muscle nAChR... 

Imidacloprid is a widely used neonicotinoid insecticide that kills pests by targeting their central nAChRs. Levamisol is used to kill nematodes by acting on nAChRs in the worm s muscles. 

NOS (eNOS, NOS IH, NOS3). Classically, nNOS and eNOS were considered constitutive enzymes, whereas iNOS is cytokine-induced. Recent evidence suggests that nNOS and eNOS are also subject to important regulation of expression [1 ]. Within the human species, amino acid sequences of the three NOS isoforms share 52-58% identity. Each isoform is well conserved across mammalian species (>90% amino acid identity for nNOS and eNOS, >80% for iNOS). NOS enzymes exist in organisms as low as nematodes, protozoa, and even in plants (Fig. 1). 

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