Allergy and Immunology: A medical specialty concerned with the hypersensitivity of the individual to foreign substances and protection from the resultant infection or disorder.Food Hypersensitivity: Gastrointestinal disturbances, skin eruptions, or shock due to allergic reactions to allergens in food.Hypersensitivity: Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.Immunoglobulin E: An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Allergens: Antigen-type substances that produce immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Skin Tests: Epicutaneous or intradermal application of a sensitizer for demonstration of either delayed or immediate hypersensitivity. Used in diagnosis of hypersensitivity or as a test for cellular immunity.Milk Hypersensitivity: Allergic reaction to milk (usually cow's milk) or milk products. MILK HYPERSENSITIVITY should be differentiated from LACTOSE INTOLERANCE, an intolerance to milk as a result of congenital deficiency of lactase.Desensitization, Immunologic: Immunosuppression by the administration of increasing doses of antigen. Though the exact mechanism is not clear, the therapy results in an increase in serum levels of allergen-specific IMMUNOGLOBULIN G, suppression of specific IgE, and an increase in suppressor T-cell activity.Drug Hypersensitivity: Immunologically mediated adverse reactions to medicinal substances used legally or illegally.Latex Hypersensitivity: Allergic reaction to products containing processed natural rubber latex such as rubber gloves, condoms, catheters, dental dams, balloons, and sporting equipment. Both T-cell mediated (HYPERSENSITIVITY, DELAYED) and IgE antibody-mediated (HYPERSENSITIVITY, IMMEDIATE) allergic responses are possible. Delayed hypersensitivity results from exposure to antioxidants present in the rubber; immediate hypersensitivity results from exposure to a latex protein.Peanut Hypersensitivity: Allergic reaction to peanuts that is triggered by the immune system.Egg Hypersensitivity: Allergic reaction to eggs that is triggered by the immune system.Anaphylaxis: An acute hypersensitivity reaction due to exposure to a previously encountered ANTIGEN. The reaction may include rapidly progressing URTICARIA, respiratory distress, vascular collapse, systemic SHOCK, and death.Transplantation Immunology: A general term for the complex phenomena involved in allo- and xenograft rejection by a host and graft vs host reaction. Although the reactions involved in transplantation immunology are primarily thymus-dependent phenomena of cellular immunity, humoral factors also play a part in late rejection.Hypersensitivity, Immediate: Hypersensitivity reactions which occur within minutes of exposure to challenging antigen due to the release of histamine which follows the antigen-antibody reaction and causes smooth muscle contraction and increased vascular permeability.National Institute of Allergy and Infectious Diseases (U.S.): Component of the NATIONAL INSTITUTES OF HEALTH. It conducts and supports basic and applied research to better understand, treat, and ultimately prevent infectious, immunologic, and allergic diseases. It was established in 1948.Rhinitis, Allergic, Seasonal: Allergic rhinitis that occurs at the same time every year. It is characterized by acute CONJUNCTIVITIS with lacrimation and ITCHING, and regarded as an allergic condition triggered by specific ALLERGENS.Immunotherapy: Manipulation of the host's immune system in treatment of disease. It includes both active and passive immunization as well as immunosuppressive therapy to prevent graft rejection.Nut Hypersensitivity: Allergic reaction to tree nuts that is triggered by the immune system.Arachis hypogaea: A plant species of the family FABACEAE that yields edible seeds, the familiar peanuts, which contain protein, oil and lectins.Immunologic Tests: Immunologic techniques involved in diagnosis.Dermatitis, Allergic Contact: A contact dermatitis due to allergic sensitization to various substances. These substances subsequently produce inflammatory reactions in the skin of those who have acquired hypersensitivity to them as a result of prior exposure.Immune System: The body's defense mechanism against foreign organisms or substances and deviant native cells. It includes the humoral immune response and the cell-mediated response and consists of a complex of interrelated cellular, molecular, and genetic components.Models, Immunological: Theoretical representations that simulate the behavior or activity of immune system, processes, or phenomena. They include the use of mathematical equations, computers, and other electrical equipment.Antigens, Plant: Substances found in PLANTS that have antigenic activity.Radioallergosorbent Test: An in vitro allergen radioimmunoassay in which allergens are coupled to an immunosorbent. The coupled allergens bind the IgE in the sera of patients which in turn binds radioisotope-labeled anti-IMMUNOGLOBULIN E antibodies.Asthma: A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).Patch Tests: Skin tests in which the sensitizer is applied to a patch of cotton cloth or gauze held in place for approximately 48-72 hours. It is used for the elicitation of a contact hypersensitivity reaction.Insect Bites and Stings: Bites and stings inflicted by insects.Eczema: A pruritic papulovesicular dermatitis occurring as a reaction to many endogenous and exogenous agents (Dorland, 27th ed).Rhinitis, Allergic, Perennial: Inflammation of the mucous membrane of the nose similar to that found in hay fever except that symptoms persist throughout the year. The causes are usually air-borne allergens, particularly dusts, feathers, molds, animal fur, etc.Immune System Diseases: Disorders caused by abnormal or absent immunologic mechanisms, whether humoral, cell-mediated, or both.Equipment Safety: Freedom of equipment from actual or potential hazards.Arthropod Venoms: Venoms from animals of the phylum Arthropoda. Those most investigated are from scorpions and spiders of the class Arachnidae and from ant, bee, and wasp families of the Insecta order Hymenoptera. The venoms contain protein toxins, enzymes, and other bioactive substances and may be lethal to man.Immunity: Nonsusceptibility to the invasive or pathogenic effects of foreign microorganisms or to the toxic effect of antigenic substances.Bee Venoms: Venoms obtained from Apis mellifera (honey bee) and related species. They contain various enzymes, polypeptide toxins, and other substances, some of which are allergenic or immunogenic or both. These venoms were formerly used in rheumatism to stimulate the pituitary-adrenal system.Vaccines: Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases.Anti-Allergic Agents: Agents that are used to treat allergic reactions. Most of these drugs act by preventing the release of inflammatory mediators or inhibiting the actions of released mediators on their target cells. (From AMA Drug Evaluations Annual, 1994, p475)Pollen: The fertilizing element of plants that contains the male GAMETOPHYTES.History, 20th Century: Time period from 1901 through 2000 of the common era.Immune Tolerance: The specific failure of a normally responsive individual to make an immune response to a known antigen. It results from previous contact with the antigen by an immunologically immature individual (fetus or neonate) or by an adult exposed to extreme high-dose or low-dose antigen, or by exposure to radiation, antimetabolites, antilymphocytic serum, etc.Immunologic Techniques: Techniques used to demonstrate or measure an immune response, and to identify or measure antigens using antibodies.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.History, 21st Century: Time period from 2001 through 2100 of the common era.Respiratory Hypersensitivity: A form of hypersensitivity affecting the respiratory tract. It includes ASTHMA and RHINITIS, ALLERGIC, SEASONAL.Dermatitis, Atopic: A chronic inflammatory genetically determined disease of the skin marked by increased ability to form reagin (IgE), with increased susceptibility to allergic rhinitis and asthma, and hereditary disposition to a lowered threshold for pruritus. It is manifested by lichenification, excoriation, and crusting, mainly on the flexural surfaces of the elbow and knee. In infants it is known as infantile eczema.Wheat Hypersensitivity: Allergic reaction to wheat that is triggered by the immune system.Rhinitis: Inflammation of the NASAL MUCOSA, the mucous membrane lining the NASAL CAVITIES.Neuroimmunomodulation: The biochemical and electrophysiological interactions between the NERVOUS SYSTEM and IMMUNE SYSTEM.Betula: A plant genus of the family BETULACEAE. The tree has smooth, resinous, varicolored or white bark, marked by horizontal pores (lenticels), which usually peels horizontally in thin sheets.Basophil Degranulation Test: An in vitro test used in the diagnosis of allergies including drug hypersensitivity. The allergen is added to the patient's white blood cells and the subsequent histamine release is measured.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Adaptive Immunity: Protection from an infectious disease agent that is mediated by B- and T- LYMPHOCYTES following exposure to specific antigen, and characterized by IMMUNOLOGIC MEMORY. It can result from either previous infection with that agent or vaccination (IMMUNITY, ACTIVE), or transfer of antibody or lymphocytes from an immune donor (IMMUNIZATION, PASSIVE).Intradermal Tests: Skin tests in which the sensitizer is injected.Dermatitis, Occupational: A recurrent contact dermatitis caused by substances found in the work place.Basophils: Granular leukocytes characterized by a relatively pale-staining, lobate nucleus and cytoplasm containing coarse dark-staining granules of variable size and stainable by basic dyes.Ant Venoms: Venoms from the superfamily Formicoidea, Ants. They may contain protein factors and toxins, histamine, enzymes, and alkaloids and are often allergenic or immunogenic.Antigens: Substances that are recognized by the immune system and induce an immune reaction.Host vs Graft Reaction: The immune responses of a host to a graft. A specific response is GRAFT REJECTION.Urticaria: A vascular reaction of the skin characterized by erythema and wheal formation due to localized increase of vascular permeability. The causative mechanism may be allergy, infection, or stress.Corylus: A plant genus of the family BETULACEAE known for the edible nuts.Biological Therapy: Treatment of diseases with biological materials or biological response modifiers, such as the use of GENES; CELLS; TISSUES; organs; SERUM; VACCINES; and humoral agents.United States Food and Drug Administration: An agency of the PUBLIC HEALTH SERVICE concerned with the overall planning, promoting, and administering of programs pertaining to maintaining standards of quality of foods, drugs, therapeutic devices, etc.Neoplasms: New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.Hereditary Autoinflammatory Diseases: Hereditary inflammation conditions, characterized by recurrent episodes of systemic inflammation. Common symptoms include recurrent fever, rash, arthritis, fatigue, and secondary AMYLOIDOSIS. Hereditary autoinflammatory diseases are associated with mutations in genes involved in regulation of normal inflammatory process and are not caused by AUTOANTIBODIES, or antigen specific T-LYMPHOCYTES.Gloves, Surgical: Gloves, usually rubber, worn by surgeons, examining physicians, dentists, and other health personnel for the mutual protection of personnel and patient.Chemistry, Clinical: The specialty of ANALYTIC CHEMISTRY applied to assays of physiologically important substances found in blood, urine, tissues, and other biological fluids for the purpose of aiding the physician in making a diagnosis or following therapy.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.Administration, Sublingual: Administration of a soluble dosage form by placement under the tongue.Immunity, Cellular: Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.Autoimmunity: Process whereby the immune system reacts against the body's own tissues. Autoimmunity may produce or be caused by AUTOIMMUNE DISEASES.History, 19th Century: Time period from 1801 through 1900 of the common era.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Mites: Any arthropod of the subclass ACARI except the TICKS. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans and domestic animals, producing various irritations of the skin (MITE INFESTATIONS). Many mite species are important to human and veterinary medicine as both parasite and vector. Mites also infest plants.Latex: A milky, product excreted from the latex canals of a variety of plant species that contain cauotchouc. Latex is composed of 25-35% caoutchouc, 60-75% water, 2% protein, 2% resin, 1.5% sugar & 1% ash. RUBBER is made by the removal of water from latex.(From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed). Hevein proteins are responsible for LATEX HYPERSENSITIVITY. Latexes are used as inert vehicles to carry antibodies or antigens in LATEX FIXATION TESTS.Cross Reactions: Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.Immunity, Mucosal: Nonsusceptibility to the pathogenic effects of foreign microorganisms or antigenic substances as a result of antibody secretions of the mucous membranes. Mucosal epithelia in the gastrointestinal, respiratory, and reproductive tracts produce a form of IgA (IMMUNOGLOBULIN A, SECRETORY) that serves to protect these ports of entry into the body.Animal Technicians: Assistants to a veterinarian, biological or biomedical researcher, or other scientist who are engaged in the care and management of animals, and who are trained in basic principles of animal life processes and routine laboratory and animal health care procedures. (Facts on File Dictionary of Health Care Management, 1988)Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Autoimmune Diseases: Disorders that are characterized by the production of antibodies that react with host tissues or immune effector cells that are autoreactive to endogenous peptides.Laryngeal Mucosa: The mucous lining of the LARYNX, consisting of various types of epithelial cells ranging from stratified squamous EPITHELIUM in the upper larynx to ciliated columnar epithelium in the rest of the larynx, mucous GOBLET CELLS, and glands containing both mucous and serous cells.Infection: Invasion of the host organism by microorganisms that can cause pathological conditions or diseases.Dendritic Cells: Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as SKIN and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process ANTIGENS, and present them to T-CELLS, thereby stimulating CELL-MEDIATED IMMUNITY. They are different from the non-hematopoietic FOLLICULAR DENDRITIC CELLS, which have a similar morphology and immune system function, but with respect to humoral immunity (ANTIBODY PRODUCTION).Epitopes, T-Lymphocyte: Antigenic determinants recognized and bound by the T-cell receptor. Epitopes recognized by the T-cell receptor are often located in the inner, unexposed side of the antigen, and become accessible to the T-cell receptors after proteolytic processing of the antigen.Virus Diseases: A general term for diseases produced by viruses.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.Nobel PrizeRespiratory Sounds: Noises, normal and abnormal, heard on auscultation over any part of the RESPIRATORY TRACT.Awards and PrizesOrgan Transplantation: Transference of an organ between individuals of the same species or between individuals of different species.Pyroglyphidae: Family of house dust mites, in the superfamily Analgoidea, order Astigmata. They include the genera Dermatophagoides and Euroglyphus.Immunization: Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).Cancer Vaccines: Vaccines or candidate vaccines designed to prevent or treat cancer. Vaccines are produced using the patient's own whole tumor cells as the source of antigens, or using tumor-specific antigens, often recombinantly produced.Wasp Venoms: Venoms produced by the wasp (Vespid) family of stinging insects, including hornets; the venoms contain enzymes, biogenic amines, histamine releasing factors, kinins, toxic polypeptides, etc., and are similar to bee venoms.Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.History, 18th Century: Time period from 1701 through 1800 of the common era.Animals, LaboratoryPrevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Clinical Trials as Topic: Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.Inflammation: A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.2S Albumins, Plant: A major class of water-soluble seed storage proteins. Many proteins from this class are major PLANT ALLERGENS.Immunologic Surveillance: The theory that T-cells monitor cell surfaces and detect structural changes in the plasma membrane and/or surface antigens of virally or neoplastically transformed cells.Lymphocyte Activation: Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.Immunomodulation: Alteration of the immune system or of an immune response by agents that activate or suppress its function. This can include IMMUNIZATION or administration of immunomodulatory drugs. Immunomodulation can also encompass non-therapeutic alteration of the immune system effected by endogenous or exogenous substances.Sesamum: A plant genus of the family PEDALIACEAE that is the source of the edible seed and SESAME OIL.Lymphocytes: White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.Antigens, Neoplasm: Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.Cupressus: A plant genus of the family CUPRESSACEAE. Cypress ordinarily refers to this but also forms part of the name of plants in other genera.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.Diagnostic Equipment: Nonexpendable items used in examination.Research: Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)Host-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.Placentation: The development of the PLACENTA, a highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products between mother and FETUS. The process begins at FERTILIZATION, through the development of CYTOTROPHOBLASTS and SYNCYTIOTROPHOBLASTS, the formation of CHORIONIC VILLI, to the progressive increase in BLOOD VESSELS to support the growing fetus.Biomedical Research: Research that involves the application of the natural sciences, especially biology and physiology, to medicine.B-Lymphocytes: Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.Anisakis: A genus of nematodes of the superfamily ASCARIDOIDEA. Its organisms are found in the stomachs of marine animals and birds. Human infection occurs by ingestion of raw fish that contain larvae.Tuberculosis Vaccines: Vaccines or candidate vaccines used to prevent or treat TUBERCULOSIS.Immunologic Deficiency Syndromes: Syndromes in which there is a deficiency or defect in the mechanisms of immunity, either cellular or humoral.Major Histocompatibility Complex: The genetic region which contains the loci of genes which determine the structure of the serologically defined (SD) and lymphocyte-defined (LD) TRANSPLANTATION ANTIGENS, genes which control the structure of the IMMUNE RESPONSE-ASSOCIATED ANTIGENS, HUMAN; the IMMUNE RESPONSE GENES which control the ability of an animal to respond immunologically to antigenic stimuli, and genes which determine the structure and/or level of the first four components of complement.Microbiology: The study of microorganisms such as fungi, bacteria, algae, archaea, and viruses.Nasal Provocation Tests: Application of allergens to the nasal mucosa. Interpretation includes observation of nasal symptoms, rhinoscopy, and rhinomanometry. Nasal provocation tests are used in the diagnosis of nasal hypersensitivity, including RHINITIS, ALLERGIC, SEASONAL.Mice, Inbred BALB CT-Lymphocytes, Regulatory: CD4-positive T cells that inhibit immunopathology or autoimmune disease in vivo. They inhibit the immune response by influencing the activity of other cell types. Regulatory T-cells include naturally occurring CD4+CD25+ cells, IL-10 secreting Tr1 cells, and Th3 cells.Antibodies: Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).Viruses: Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Immunoglobulins: Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.Graft Rejection: An immune response with both cellular and humoral components, directed against an allogeneic transplant, whose tissue antigens are not compatible with those of the recipient.Dust: Earth or other matter in fine, dry particles. (Random House Unabridged Dictionary, 2d ed)Immunoassay: A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.Laboratories: Facilities equipped to carry out investigative procedures.Serologic Tests: Diagnostic procedures involving immunoglobulin reactions.Epitopes: Sites on an antigen that interact with specific antibodies.Neurosciences: The scientific disciplines concerned with the embryology, anatomy, physiology, biochemistry, pharmacology, etc., of the nervous system.Chimerism: The occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from different individuals. This contrasts with MOSAICISM in which the different cell populations are derived from a single individual.Infant, Newborn: An infant during the first month after birth.Disease Susceptibility: A constitution or condition of the body which makes the tissues react in special ways to certain extrinsic stimuli and thus tends to make the individual more than usually susceptible to certain diseases.Anacardium: A plant genus of the family ANACARDIACEAE. This is the source of the familiar cashew nuts, which are heat treated to remove the irritant toxin. Cashew nut shell liquid (frequently abbreviated as CNSL) is a major source of alkenyl phenolic compounds, especially ANACARDIC ACIDS, cardol, and cardanol.Cockroaches: Insects of the order Dictyoptera comprising several families including Blaberidae, BLATTELLIDAE, Blattidae (containing the American cockroach PERIPLANETA americana), Cryptocercidae, and Polyphagidae.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.CD4-Positive T-Lymphocytes: A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.Infant Formula: Liquid formulations for the nutrition of infants that can substitute for BREAST MILK.Transplantation Tolerance: An induced state of non-reactivity to grafted tissue from a donor organism that would ordinarily trigger a cell-mediated or humoral immune response.Anisakiasis: Infection with roundworms of the genus ANISAKIS. Human infection results from the consumption of fish harboring roundworm larvae. The worms may cause acute NAUSEA; VOMITING; or penetrate into the wall of the DIGESTIVE TRACT where they give rise to EOSINOPHILIC GRANULOMA in the STOMACH; INTESTINES; or the OMENTUM.Communicable DiseasesEnzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Milk: The white liquid secreted by the mammary glands. It contains proteins, sugar, lipids, vitamins, and minerals.Immunity, Active: Resistance to a disease agent resulting from the production of specific antibodies by the host, either after exposure to the disease or after vaccination.United StatesPhleum: A plant genus of the family POACEAE that contains the Phl p 4 allergen.HLA Antigens: Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.Histamine Release: The secretion of histamine from mast cell and basophil granules by exocytosis. This can be initiated by a number of factors, all of which involve binding of IgE, cross-linked by antigen, to the mast cell or basophil's Fc receptors. Once released, histamine binds to a number of different target cell receptors and exerts a wide variety of effects.Shellfish: Aquatic invertebrates belonging to the phylum MOLLUSCA or the subphylum CRUSTACEA, and used as food.Ovalbumin: An albumin obtained from the white of eggs. It is a member of the serpin superfamily.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Gastrointestinal Tract: Generally refers to the digestive structures stretching from the MOUTH to ANUS, but does not include the accessory glandular organs (LIVER; BILIARY TRACT; PANCREAS).Vaccination: Administration of vaccines to stimulate the host's immune response. This includes any preparation intended for active immunological prophylaxis.Hymenoptera: An extensive order of highly specialized insects including bees, wasps, and ants.Eggs: Animal reproductive bodies, or the contents thereof, used as food. The concept is differentiated from OVUM, the anatomic or physiologic entity.Immunosuppression: Deliberate prevention or diminution of the host's immune response. It may be nonspecific as in the administration of immunosuppressive agents (drugs or radiation) or by lymphocyte depletion or may be specific as in desensitization or the simultaneous administration of antigen and immunosuppressive drugs.Antigen-Antibody Reactions: The processes triggered by interactions of ANTIBODIES with their ANTIGENS.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.CD8-Positive T-Lymphocytes: A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.T-Lymphocyte Subsets: A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.Receptors, Antigen, T-Cell: Molecules on the surface of T-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (ANTIGENS, CD3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (RECEPTORS, ANTIGEN, T-CELL, ALPHA-BETA) or gamma-delta (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA) chains.Computational Biology: A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.Maternal-Fetal Exchange: Exchange of substances between the maternal blood and the fetal blood at the PLACENTA via PLACENTAL CIRCULATION. The placental barrier excludes microbial or viral transmission.Mice, Inbred C57BLTumor Escape: The ability of tumors to evade destruction by the IMMUNE SYSTEM. Theories concerning possible mechanisms by which this takes place involve both cellular immunity (IMMUNITY, CELLULAR) and humoral immunity (ANTIBODY FORMATION), and also costimulatory pathways related to CD28 antigens (ANTIGENS, CD28) and CD80 antigens (ANTIGENS, CD80).Angioedema: Swelling involving the deep DERMIS, subcutaneous, or submucosal tissues, representing localized EDEMA. Angioedema often occurs in the face, lips, tongue, and larynx.Leukocytes: White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).Toll-Like Receptors: A family of pattern recognition receptors characterized by an extracellular leucine-rich domain and a cytoplasmic domain that share homology with the INTERLEUKIN 1 RECEPTOR and the DROSOPHILA toll protein. Following pathogen recognition, toll-like receptors recruit and activate a variety of SIGNAL TRANSDUCING ADAPTOR PROTEINS.Antigens, CD63: Ubiquitously-expressed tetraspanin proteins that are found in late ENDOSOMES and LYSOSOMES and have been implicated in intracellular transport of proteins.