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conversion reaction |
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reaction /re·ac·tion/ (-ak´shun) 1. opposite action, or counterreaction; the response to stimuli. 2. a phenomenon caused by the action of chemical agents; a chemical process in which one substance is transformed into another substance or other substances. 3. the mental and/or emotional state that develops in any particular situation. acrosome reaction structural changes and liberation of acrosomal enzymes occurring in spermatozoa in the vicinity of an oocyte, facilitating entry into the oocyte. alarm reaction the physiologic effects (increase in blood pressure, cardiac output, blood flow to skeletal muscles, rate of glycolysis, and blood glucose concentration; decrease in blood flow to viscera) mediated by sympathetic nervous system discharge and release of adrenal medullary hormones in response to stress, fright, or rage. allergic reaction hypersensitivity r., sometimes specifically a type I hypersensitivity reaction. anaphylactic reaction anaphylaxis. anaphylactoid reaction one resembling generalized anaphylaxis but not caused by IgE-mediated allergic reaction. antibody-mediated hypersensitivity reaction 1. type II hypersensitivity r.; see Gell and Coombs classification, under classification. 2. occasionally, any hypersensitivity reaction in which antibodies are the primary mediators, i.e., types I–III. antigen-antibody reaction the reversible binding of antigen to homologous antibody by the formation of weak bonds between antigenic determinants on antigen molecules and antigen binding sites on immunoglobulin molecules. anxiety reaction a reaction characterized by abnormal apprehension or uneasiness; see also anxiety disorders, under disorder. Arias-Stella reaction nuclear and cellular hypertrophy of the endometrial epithelium, associated with ectopic pregnancy. cell-mediated hypersensitivity reaction type IV hypersensitivity r.; see Gell and Coombs classification, under classification. conversion reaction see under disorder. cross reaction the interaction of an antigen with an antibody formed against a different antigen with which the first antigen shares identical or closely related antigenic determinants. cytotoxic hypersensitivity reaction type II hypersensitivity r.; see Gell and Coombs classification, under classification. defense reaction see under mechanism. delayed hypersensitivity reaction , delayed-type hypersensitivity reaction that taking 24 to 72 hours to develop and mediated by T lymphocytes rather than by antibodies; usually denoting the subset of type IV hypersensitivity reactions involving cytokine release and macrophage activation, as opposed to direct cytolysis, but sometimes used more broadly, even as a synonym for type IV hypersensitivity r. (see Gell and Coombs classification, under classification ). reaction of degeneration the reaction to electrical stimulation of muscles whose nerves have degenerated, consisting of loss of response to a faradic stimulation in a muscle, and to galvanic and faradic stimulation in the nerve. foreign body reaction a granulomatous inflammatory reaction evoked by the presence of exogenous material in the tissues, characterized by the formation of foreign body giant cells. hemiopic pupillary reaction in certain cases of hemianopia, light thrown upon one side of the retina causes the iris to contract, while light thrown upon the other side arouses no response. Herxheimer's reaction Jarisch-Herxheimer r. hypersensitivity reaction one in which the body mounts an exaggerated or inappropriate immune response to a substance perceived as foreign, resulting in local or general tissue damage. Such reactions are usually classified as types I–IV on the basis of the Gell and Coombs classification (q.v.). id reaction a secondary skin eruption occurring in sensitized patients as a result of circulation of allergenic products from a primary site of infection. immediate hypersensitivity reaction 1. type I hypersensitivity r.; see Gell and Coombs classification, under classification. 2. occasionally, any hypersensitivity reaction mediated by antibodies and developing rapidly, generally in minutes to hours (i.e., types I–III ), as distinguished from those mediated by T lymphocytes and macrophages and requiring days to develop (type IV, or delayed hypersensitivity r. ). immune reaction see under response. immune complex–mediated hypersensitivity reaction type III hypersensitivity r.; see Gell and Coombs classification, under classification. Jarisch-Herxheimer reaction a transient immunologic reaction following antibiotic treatment of early and later stages of syphilis and certain other diseases, marked by fever, chills, headache, myalgia, and exacerbation of cutaneous lesions; due to release of toxic or antigenic substances by the infecting microorganisms. Jones-Mote reaction a mild skin reaction of the delayed (type IV) hypersensitivity type occurring after challenge with protein antigens. late phase reaction an IgE-mediated immune reaction occurring 5 to 8 hours after exposure to antigen, after the wheal and flare reactions of immediate hypersensitivity have diminished, with inflammation peaking around 24 hours, and then subsiding. lengthening reaction reflex elongation of the extensor muscles which permits flexion of a limb. leukemoid reaction a peripheral blood picture resembling that of leukemia or indistinguishable from it on the basis of morphologic appearance alone; seen in certain infectious diseases, inflammatory conditions, and intoxications. Neufeld's reaction swelling of the capsules of pneumococci, seen under the microscope, on mixture with specific immune serum, owing to the binding of antibody with the capsular polysaccharide. oxidation-reduction reaction redox r. Pirquet reaction appearance of a papule with a red areola 24 to 48 hours after introduction of two small drops of Old tuberculin by slight scarification of the skin; a positive test indicates previous infection. polymerase chain reaction (PCR) a rapid technique for in vitro amplification of specific DNA or RNA sequences, allowing small quantities of short sequences to be analyzed without cloning. precipitin reaction the formation of an insoluble precipitate by reaction of antigen and antibody. redox reaction a reaction oxidizing one substrate while reducing another. Schultz-Charlton reaction disappearance of scarlet fever rash around the site of an injection of scarlet fever antitoxin. serum reaction seroreaction. startle reaction the various psychophysiological phenomena, including involuntary motor and autonomic reactions, evidenced by an individual in reaction to a sudden, unexpected stimulus, as a loud noise. stress reaction any physiological or psychological reaction to physical, mental, or emotional stress that disturbs the organism's homeostasis. T cell–mediated hypersensitivity reaction type IV hypersensitivity r.; see Gell and Coombs classification, under classification. Weil-Felix reaction agglutination by blood serum of typhus patients of a bacillus of the proteus group from the urine and feces. Wernicke's reaction hemiopic pupillary r. wheal and erythema reaction , wheal and flare reaction a cutaneous sensitivity reaction to skin injury or administration of antigen, due to histamine production and marked by edematous elevation and erythematous flare. conversion reaction, an ego defense mechanism whereby intrapsychic conflict is expressed symbolically through physical symptoms. conversion reaction Conversion hysteria, conversion symptom Psychiatry A constellation of Sx that suggest organic brain disease, which affect voluntary muscles and sensory organs Clinical Paralysis, blindness, dysphagia, deafness, aphonia,
SOB, spells, anesthesia, incoordination, amnesia, unconsciousness. Cf Hysterical reaction. Patient discussion about conversion reaction. Q. While in a conversation with anyone they have about a minute before I loose tract and intrest, Is this ADHD I always feel like I have to go full speed 24/7 and can never relax, sounds strange I know but it seems to be catching up with me. A. not necessarily...i see that you are 31. those symptoms are new? if so- thee are other conditions that might cause them. hyperthyroid can get you in that state too. so it might be a good idea to go and get checked up. Q. What are the common caloric conversions? Hi my new friends, help me to find out how does caloric expenditure affect weight loss? What are the common caloric conversions? A. Hi my new friend. Welcome to this community. I have given here the caloric equivalents for your reference: Read more or ask a question about conversion reaction1 pound = 3500 kcal 1 gram fat = 9 kcal 1 gram carbohydrate = 4 kcal 1 gram protein = 4 kcal 1 gram alcohol = 7 kcal Example: How does caloric expenditure affect weight loss? An individual creates a caloric deficit by walking one mile to and from work each day. Assuming a 100 calorie per mile caloric expenditure, how many weeks would it take to lose one pound? 1 lb = 3500 calories 2 miles per day x 5 days = 10 miles 10 miles x 100 calories = 1000 calories per week 3,500 calories ÷ 1000 = 3.5 weeks This information is a fundamental for ACE certifications. Knowledge on this subject is required by our professionals. |
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Alternatively, the conversion reaction can be rewritten as the sum of several intermediate steps, including the formation of a barium hydroxide liquid: Chapter 2 describes a cell-free conversion reaction system to study how pathogenic prions associated with different species interact with host cellular prion protein. Stridor as an initial symptom of a conversion reaction (hysteria) is rare. |
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