Nematode Infections: Infections by nematodes, general or unspecified.Nematoda: A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites.Tylenchoidea: A superfamily of nematodes whose members are free-living saprophytes or parasites of plants. Ova are sometimes found in human feces after ingestion of infected plants.Trichinella spiralis: A parasite of carnivorous mammals that causes TRICHINELLOSIS. It is especially common in rats and in swine fed uncooked garbage. Human infection is initiated by the consumption of raw or insufficiently cooked pork or other meat containing the encysted larvae.Intestinal Diseases, Parasitic: Infections of the INTESTINES with PARASITES, commonly involving PARASITIC WORMS. Infections with roundworms (NEMATODE INFECTIONS) and tapeworms (CESTODE INFECTIONS) are also known as HELMINTHIASIS.Strongylida Infections: Infections with nematodes of the order STRONGYLIDA.Trichinellosis: An infection with TRICHINELLA. It is caused by eating raw or undercooked meat that is infected with larvae of nematode worms TRICHINELLA genus. All members of the TRICHINELLA genus can infect human in addition to TRICHINELLA SPIRALIS, the traditional etiological agent. It is distributed throughout much of the world and is re-emerging in some parts as a public health hazard and a food safety problem.Nematospiroides dubius: A species of intestinal nematode parasites which occur most commonly in mice. Infection is by ingesting larvae. This particular species is used extensively in immunological research.Trichostrongylus: A genus of parasitic nematodes found in the digestive tract of herbivorous animals. They cause incidental infections in humans from the following species: Trichostrongylus colubriformis, T. orientalis, T. axei, and T. probolurus.Trichuriasis: Infection with nematodes of the genus TRICHURIS, formerly called Trichocephalus.Heligmosomatoidea: A superfamily of parasitic nematodes which were formerly considered a part of TRICHOSTRONGYLOIDEA. It includes the following genera: Heligmosomum, NEMATOSPIROIDES, and NIPPOSTRONGYLUS. The hosts are rodents.Nippostrongylus: A genus of intestinal nematode parasites belonging to the superfamily HELIGMOSOMATOIDEA, which commonly occurs in rats but has been experimentally transmitted to other rodents and rabbits. Infection is usually through the skin.Trichostrongylosis: Infestation with nematode worms of the genus TRICHOSTRONGYLUS. Man and animals become infected by swallowing larvae, usually with contaminated food or drink, although the larvae may penetrate human skin.Trichuris: A genus of nematode worms comprising the whipworms.Parasite Egg Count: Determination of parasite eggs in feces.Filarioidea: A superfamily of nematodes of the suborder SPIRURINA. Its organisms possess a filiform body and a mouth surrounded by papillae.Haemonchus: A genus of parasitic nematode worms which infest the duodenum and stomach of domestic and wild herbivores, which ingest it with the grasses (POACEAE) they eat. Infestation of man is accidental.Brugia malayi: A species of parasitic nematode causing Malayan filariasis and having a distribution centering roughly on the Malay peninsula. The life cycle of B. malayi is similar to that of WUCHERERIA BANCROFTI, except that in most areas the principal mosquito vectors belong to the genus Mansonia.Antinematodal Agents: Substances used in the treatment or control of nematode infestations. They are used also in veterinary practice.Sheep Diseases: Diseases of domestic and mountain sheep of the genus Ovis.Anthelmintics: Agents destructive to parasitic worms. They are used therapeutically in the treatment of HELMINTHIASIS in man and animal.Host-Parasite Interactions: The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Plant Roots: The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)Haemonchiasis: Infection with nematodes of the genus HAEMONCHUS, characterized by digestive abnormalities and anemia similar to that from hookworm infestation.Filariasis: Infections with nematodes of the superfamily FILARIOIDEA. The presence of living worms in the body is mainly asymptomatic but the death of adult worms leads to granulomatous inflammation and permanent fibrosis. Organisms of the genus Elaeophora infect wild elk and domestic sheep causing ischemic necrosis of the brain, blindness, and dermatosis of the face.Gastrointestinal Diseases: Diseases in any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM.Plant Diseases: Diseases of plants.Antigenic Modulation: Loss of detectable antigen from the surface of a cell after incubation with antibodies. This is one method in which some tumors escape detection by the immune system. Antigenic modulation of target antigens also reduces the therapeutic effectiveness of treatment by monoclonal antibodies.Trichinella: A genus of parasitic nematodes that causes TRICHINELLOSIS in man and other animal.Caenorhabditis elegans: A species of nematode that is widely used in biological, biochemical, and genetic studies.Antibodies, Helminth: Immunoglobulins produced in a response to HELMINTH ANTIGENS.Hookworm Infections: Infection of humans or animals with hookworms other than those caused by the genus Ancylostoma or Necator, for which the specific terms ANCYLOSTOMIASIS and NECATORIASIS are available.Interleukin-13: A cytokine synthesized by T-LYMPHOCYTES that produces proliferation, immunoglobulin isotype switching, and immunoglobulin production by immature B-LYMPHOCYTES. It appears to play a role in regulating inflammatory and immune responses.Rhabditida: An order of nematodes of the subclass SECERNENTEA. Its organisms are characterized by an annulated or smooth cuticle and the absence of caudal glands.Chymases: A family of neutral serine proteases with CHYMOTRYPSIN-like activity. Chymases are primarily found in the SECRETORY GRANULES of MAST CELLS and are released during mast cell degranulation.Strongyloidiasis: Infection with nematodes of the genus STRONGYLOIDES. The presence of larvae may produce pneumonitis and the presence of adult worms in the intestine could lead to moderate to severe diarrhea.Caenorhabditis: A genus of small free-living nematodes. Two species, CAENORHABDITIS ELEGANS and C. briggsae are much used in studies of genetics, development, aging, muscle chemistry, and neuroanatomy.Interleukin-4: A soluble factor produced by activated T-LYMPHOCYTES that induces the expression of MHC CLASS II GENES and FC RECEPTORS on B-LYMPHOCYTES and causes their proliferation and differentiation. It also acts on T-lymphocytes, MAST CELLS, and several other hematopoietic lineage cells.Mastocytosis: A heterogenous group of disorders characterized by the abnormal increase of MAST CELLS in only the skin (MASTOCYTOSIS, CUTANEOUS), in extracutaneous tissues involving multiple organs (MASTOCYTOSIS, SYSTEMIC), or in solid tumors (MASTOCYTOMA).Th2 Cells: Subset of helper-inducer T-lymphocytes which synthesize and secrete the interleukins IL-4, IL-5, IL-6, and IL-10. These cytokines influence B-cell development and antibody production as well as augmenting humoral responses.Helminth Proteins: Proteins found in any species of helminth.Goblet Cells: A glandular epithelial cell or a unicellular gland. Goblet cells secrete MUCUS. They are scattered in the epithelial linings of many organs, especially the SMALL INTESTINE and the RESPIRATORY TRACT.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Receptors, Interleukin-4: Receptors present on a wide variety of hematopoietic and non-hematopoietic cell types that are specific for INTERLEUKIN-4. They are involved in signaling a variety of immunological responses related to allergic INFLAMMATION including the differentiation of TH2 CELLS and the regulation of IMMUNOGLOBULIN E production. Two subtypes of receptors exist and are referred to as the TYPE I INTERLEUKIN-4 RECEPTOR and the TYPE II INTERLEUKIN-4 RECEPTOR. Each receptor subtype is defined by its unique subunit composition.Mice, Inbred BALB CRhabditoidea: A superfamily of nematodes of the order RHABDITIDA. Characteristics include an open tube stoma and an excretory system with lateral canals.Intestinal Mucosa: Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.STAT6 Transcription Factor: A signal transducer and activator of transcription that mediates cellular responses to INTERLEUKIN-4. Stat6 has been shown to partner with NF-KAPPA B and CCAAT-ENHANCER-BINDING PROTEINS to regulate GENETIC TRANSCRIPTION of interleukin-4 responsive GENES.Tylenchida: An order of nematodes consisting of many species which are plant parasites. Female worms lay eggs that hatch either in soil or in the host plant.Genes, Helminth: The functional hereditary units of HELMINTHS.DNA, Helminth: Deoxyribonucleic acid that makes up the genetic material of helminths.Soybeans: An annual legume. The SEEDS of this plant are edible and used to produce a variety of SOY FOODS.Caenorhabditis elegans Proteins: Proteins from the nematode species CAENORHABDITIS ELEGANS. The proteins from this species are the subject of scientific interest in the area of multicellular organism MORPHOGENESIS.Intestines: The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.Sheep: Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.Mice, Inbred C57BLFeces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Genome, Helminth: The genetic complement of a helminth (HELMINTHS) as represented in its DNA.Ascaris: A genus of nematodes of the superfamily ASCARIDOIDEA whose species usually inhabit the intestine.Mast Cells: Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the BASOPHILS, mast cells contain large amounts of HISTAMINE and HEPARIN. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the STEM CELL FACTOR.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Interleukin-5: A cytokine that promotes differentiation and activation of EOSINOPHILS. It also triggers activated B-LYMPHOCYTES to differentiate into IMMUNOGLOBULIN-secreting cells.Immunity, Innate: The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.Cytokines: Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.RNA, Helminth: Ribonucleic acid in helminths having regulatory and catalytic roles as well as involvement in protein synthesis.Immunoglobulin E: An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.Ostertagia: A genus of parasitic nematodes occurring in the stomach of ruminants.Xenorhabdus: A genus of gram-negative, facultatively anaerobic rod-shaped cells which are motile by peritrichous flagella. Late in the growth cycle, spheroplasts or coccoid bodies occur, resulting from disintegration of the cell wall. The natural habitat is the intestinal lumen of certain nematodes. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Photorhabdus: A genus of gram-negative bacteria existing symbiotically with nematodes of the family Heterorhabditidae (see RHABDITOIDEA). These nematodes infect a variety of soil-dwelling insects. Upon entering an insect host, the nematode releases Photorhabdus from its intestinal tract and the bacterium establishes a lethal septicemia in the insect.Helminthiasis, Animal: Infestation of animals with parasitic worms of the helminth class. The infestation may be experimental or veterinary.Trichostrongyloidea: A superfamily of nematodes. Most are intestinal parasites of ruminants and accidentally in humans. This superfamily includes seven genera: DICTYOCAULUS; HAEMONCHUS; Cooperia, OSTERTAGIA; Nematodirus, TRICHOSTRONGYLUS; and Hyostrongylus.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.