1. To prove; to try a substance; to determine the chemical nature of a substance by means of reagents. 2. A method of examination, as to determine the presence or absence of a definite disease or of some substance in any of the fluids, tissues, or excretions of the body, or to determine the presence or degree of a psychologic or behavioral trait. 3. A reagent used in making a t. 4. See testa (1). SEE ALSO: assay, reaction, reagent, scale, stain. [L. testum, an earthen vessel]
- acetone t. a t. for ketonuria; the suspected urine is shaken up with a few drops of sodium nitroprusside, and strong ammonia water is then gently poured over the mixture; if acetone is present, a magenta ring forms at the line of contact; tablets containing sodium nitroprusside and alkali are now more commonly used.
- achievement t. a standardized t. used to measure acquired learning, e.g., competence in a specific subject area such as reading or arithmetic, in contrast to an intelligence t., which is a useful index of potential ability or learning.
- acidified serum t. lysis of the patient's red blood cells in acidified fresh serum, specific for paroxysmal nocturnal hemoglobinuria. SYN: Ham t..
- acid phosphatase t. for semen a screening t. for semen by determining acid phosphatase content; because seminal fluid contains high concentrations of acid phosphatase, while other body fluids and extraneous foreign materials have very low concentrations, high values of acid phosphatase on vaginal aspirate or lavage, or on wash fluid from stains, render positive identification of semen, even if the male is aspermic.
- acid reflux t. a t. to detect gastroesophageal reflux by monitoring esophageal pH by an electrode in the distal esophagus either basally or after acid is instilled into the stomach.
- acoustic stimulation t. a t. for fetal well-being through use of an acoustic device to stimulate the fetus and cause accelerated fetal heart rate.
- ACTH stimulation t. a t. for adrenal cortical function; ACTH administered by continuous intravenous infusion, or intramuscularly, evokes an increase in plasma cortisol in normal persons; in adrenal cortical insufficiency, the expected increase in plasma cortisol is limited or nonexistent.
- adhesion t. the diagnostic application of the immune adhesion phenomenon. SYN: erythrocyte adherence t., immune adhesion t., red cell adherence t..
- Adson t. a t. for thoracic outlet syndrome; the patient is seated, with head extended and turned to the side of the lesion; with deep inspiration there is a diminution or total loss of radial pulse on the affected side. Not all patients with a positive Adson t. have thoracic outlet syndrome. SYN: Adson maneuver.
- agglutination t. any of a variety of tests that are dependent on the clumping of cells, microorganisms, or particles when mixed with specific antiserum.
- Albarran t. a t. for renal insufficiency wherein the drinking of large quantities of water will cause a proportionate increase in the volume of urine if the kidneys are sound, but not if the epithelium of the secreting tubules is damaged. SYN: polyuria t..
- alkali denaturation t. a t. for hemoglobin F (Hb F), based on the fact that hemoglobins, with the exception of Hb F, are denatured by alkali to alkaline hematin; the t. is sensitive to 2% or more Hb F.
- Allen t. 1. for phenol : upon the addition of 5 or 6 drops of hydrochloric acid and then 1 of nitric acid to the suspected fluid, a red color develops; [A.H. Allen] 2. for strychnine : fluid is extracted with ether, which is then evaporated by means of “drop-by-drop” pipetting into a warmed porcelain dish or crucible; the residue is treated with a small bit of manganese dioxide and dilute sulfuric acid; a red-blue or violet color develops if strychnine is present. [A.H. Allen] 3. a t. for radial or ulnar patency; either the radial or ulnar artery is digitally compressed by the examiner after blood has been forced out of the hand by clenching it into a fist; failure of the blood to diffuse into the hand when opened indicates that the artery not compressed is occluded. [Edgar Van Nuys Allen]
- Allen-Doisy t. a t. for estrogenic activity; the material to be investigated is injected repeatedly into immature or spayed rats or mice; the disappearance of leukocytes from the vaginal smear and the appearance of cornified cells constitutes a positive reaction.
- Almén t. for blood an obsolete t. in which glacial acetic acid, gum guaiac solution, and hydrogen peroxide are added to an aqueous suspension of the suspected stain; if occult blood or blood pigment is present, a blue color develops. SYN: guaiac t., Schönbein t., van Deen t..
- Alpha tests a set of paper and pencil-administered mental tests first used in the United States Army in 1917–1918 to determine the mental ability of literate recruits; the set includes 8 different types of tests: i.e., directions, arithmetical problems, practical judgement, synonyms and antonyms, disarrayed sentences, number series completions, analogies, and information; they are designed especially for testing large groups of individuals simultaneously, and for rapid machine scoring; distinguished from the Army Beta tests, a complementary set for administration to recruits who could not read or write English, in which the instructions are given in signs and the t. material is pictorial. See Beta tests. SYN: Army Alpha tests.
- alternate binaural loudness balance t., ABLB t. a t. for recruitment in one ear; the comparison of relative loudness of a series of intensities presented alternately to either ear.
- alternate cover t. a t. to detect phoria or strabismus; attention is directed to a small fixation object, and one eye is covered for several seconds; then the cover is moved quickly to the other eye; if the eye moves when it is uncovered, a strabismus or phoria is present. SYN: cover-uncover t..
- alternating light t. t. to detect a relative afferent defect in one eye by watching pupillary movements. With the patient fixing in the distance, the light is held on each eye for about a second, and quickly moved to the other eye. Assuming no defect of the innervation to the iris sphincter in one eye (which would produce an anisocoria in light), the eye with the weaker light response has a relative afferent pupillary defect. This asymmetry of pupillomotor input can be estimated by holding neutral density filters in front of the better eye until the pupillary responses of the two eyes are balanced. SYN: swinging light t..
- Ames t. a screening t. for possible carcinogens using strains of Salmonella typhimurium that are unable to synthesize histidine; if the t. substance produces mutations that regain the ability to synthesize histidine, the substance is carcinogenic. SYN: Ames assay.
- Anderson-Collip t. an obsolete procedure for evaluating the thyrotropic activity of an extract of the anterior lobe of the pituitary gland, as indicated by an increased basal metabolic rate or histologic evidence of stimulation of the thyroid gland in a hypophysectomized rat injected with the t. extract.
- Anderson and Goldberger t. an obsolete t. for typhus in which the patient's blood is injected into a guinea pig 's peritoneal cavity. In typhus a typical temperature curve will be observed.
- anoxemia t. an obsolete t. for coronary insufficiency; the patient breathes a mixture of 10% oxygen and 90% nitrogen; if anginal pain or electrocardiographic abnormalities are induced, the t. is positive. SYN: hypoxemia t..
- anterior apprehension t. 1. SYN: shoulder apprehension sign. 2. a t. of shoulder stability; apprehension with abduction and external rotation of the joint suggests anterior instability. SYN: crank t..
- antibiotic sensitivity t. the in vitro testing of bacterial cultures with antibiotics to determine susceptibility of bacteria to antibiotic therapy. SEE ALSO: Bauer-Kirby t..
- antiglobulin t. SYN: Coombs t..
- antithrombin t. a procedure for estimating the inhibitory effect of a defibrinated specimen of plasma on the action of thrombin in converting fibrinogen to fibrin.
- Apt t. a t. for identifying fetal blood by the addition of sodium hydroxide and water to a specimen.
- aptitude t. an occupation-oriented intelligence t. used to evaluate a person's abilities, talents, and skills; particularly valuable in vocational counseling.
- Army General Classification T. a selection screening t. of overall intellectual ability administered to entering army recruits for use in determining qualifications for entry into one of the wide range of positions to which each individual is assigned at the end of basic training.
- ascorbate-cyanide t. a t. for glucose 6-phosphate -deficient red blood cells; blood is incubated with sodium cyanide and ascorbate; the hydrogen peroxide generated is free to oxidize hemoglobin to methemoglobin, since cyanide inhibits catalase; a brown color is produced more rapidly in glucose 6-phosphate -deficient cells.
- association t. a word (stimulus word) is spoken to the subject, who is to reply immediately with another word (reaction word) suggested by the first; used as a diagnostic aid in psychiatry and psychology, clues being given by the length of time (association time) between the stimulus and reaction words, and also by the nature of the reaction words.
- Astwood t. SYN: metrotrophic t..
- aussage t. a t. of ability to reproduce correctly something that has been seen for a brief interval. [Ger. Aussage, a declaration]
- autohemolysis t. when sterile defibrinated blood is incubated at 37°C, normal red blood cells hemolyze slowly; cells with membrane or metabolic defects do so to a greater extent.
- Bachman t. a skin t. for trichinosis in which an extract of Trichinella larvae is suspended in saline and injected intradermally. An immediate wheal-and-flare reaction or a delayed response indicates infection.
- Bachman-Pettit t. a modification of the Kober t. for the detection of estradiol and similar estrogenic hormones in the urine.
- Bagolini t. a t. for retinal correspondence with the subject observing a figure through two striated lenses.
- Bárány caloric t. a t. for vestibular function, made by irrigating the external auditory meatus with either hot or cold water; this normally causes stimulation of the vestibular apparatus, resulting in nystagmus and past-pointing; in vestibular disease, the response may be reduced or absent. SYN: caloric t., nystagmus t..
- Bauer-Kirby t. a standardized t. for microbiologic susceptibility performed by transferring a standardized pure culture of the organism of interest onto a sensitivity plate (Petri dish with Mueller-Hinton agar) and observing growth in the presence of disks containing antibiotics.
- BEI t. SYN: butanol-extractable iodine t..
- belt t. an obsolete t.: firm upward pressure on the lower part of the abdomen will remove the feeling of discomfort in cases of enteroptosia.
- Bender gestalt t. a psychological t. used by neurologists and clinical psychologists to measure a person's ability to visually copy a set of geometric designs; useful for measuring visuospatial and visuomotor coordination to detect brain damage. SYN: Bender Visual Motor Gestalt t..
- Benedict t. for glucose a copper-reduction t. for glucose in the urine, which involves thiocyanate in addition to copper sulfate for qualitative or quantitative use.
- bentiromide t. a t. of pancreatic exocrine function that does not require duodenal intubation : orally administered bentiromide is cleaved by chymotrypsin within the lumen of the small intestine, releasing p-aminobenzoic acid which is absorbed and excreted in the urine; diminished urinary excretion of p-aminobenzoic acid suggests pancreatic insufficiency.
- bentonite flocculation t. an obsolete flocculation t. for rheumatoid arthritis in which sensitized bentonite particles are added to inactivated serum; the t. is positive if half of the particles are clumped while the other half remain in suspension.
- benzidine t. a t. for blood; the suspected fluid is treated with glacial acetic acid and ether, and the latter is then decanted and treated with hydrogen peroxide and a solution of benzidine in acetic acid; the presence of blood is indicated by a bluish color turning to purple. SYN: Adler t..
- Bernstein t. a t. to establish that substernal pain is due to reflux esophagitis, performed by instillation of a weak hydrochloric acid solution directly into the lower esophagus by means of a tube; symptoms disappear when the acid solution is replaced by normal saline solution. SYN: acid perfusion t..
- Beta tests a set of pictorially administered mental tests first used in the United States Army in 1917–1918 to determine the relative mental ability of recruits who were illiterate or deficient in reading and writing English, the instructions being given in signs and the t. material is pictorial in character; distinguished from the Alpha tests, which were administered at the same time to literate recruits. SYN: Army Beta tests.
- Betke-Kleihauer t. a slide t. for the presence of fetal red blood cells among those of the mother; hemoglobins other than Hb F are eluted from the red blood cells on an air-dried blood film by a buffer of pH 3.3.
- Bettendorff t. a t. for arsenic; after mixing the suspected fluid with hydrochloric acid a solution of stannous chloride is added; when a piece of tin foil is then added, a brown precipitate forms.
- bile acid tolerance t. a sensitive t. of hepatic dysfunction; following oral administration of labeled or unlabeled bile acid, the measured fractional disappearance rate or 10-minute retention is measured.
- bile esculin t. a biochemical t. used in characterizing group O streptococci, based on the ability of organisms to grow in a medium containing bile and to hydrolyze esculin.
- bile solubility t. a procedure that differentiates Streptococcus pneumoniae from other α-hemolytic streptococci by demonstrating its susceptibility to lysis in the presence of bile.
- binaural alternate loudness balance t. a t. for recruitment in one ear; the comparison of relative loudness of a series of intensities presented alternately to either ear.
- bithermal caloric t. a t. of vestibular function in which each ear canal is alternately or simultaneously irrigated with water at 7°C above or below body temperature; the nystagmus produced may be monitored for direction, amplitude, speed of the slow component, and duration.
- biuret t. a t. for the determination of serum proteins, based on the reaction of an alkaline copper reagent with substances containing two or more peptide bonds to produce a violet-blue color.
- blind t. a method of testing in which an independent observer records the results of any t., drug, placebo, or procedure without knowing the identity of the samples or what result might be expected.
- block design t. a performance t. using colored blocks which the individual must use to match pictured designs; one of the subtests of the Wechsler intelligence scales.
- Bonney t. SYN: Marshall t..
- breath t. any diagnostic t. in which endogenous or exogenous materials are measured in samples of breath as a means of identifying pathologic processes; examples include hydrogen breath testing for lactose intolerance or urea breath testing to detect gastric colonization with Helicobacter pylori. SYN: breath analysis.
- breath-holding t. a rough index of cardiopulmonary reserve measured by the length of time that a subject can voluntarily stop breathing; normal duration is 30 sec or more; diminished cardiac or pulmonary reserve is indicated by a duration of 20 sec or less.
- bromphenol t. a colorimetric t. for measurement of protein, albumin, and globulin in the urine by use of reagent strips.
- bromsulphalein t. obsolete t. for liver function (hepatic excretory capacity) in which a known amount of dye, usually 5 mg/kg of body weight, is injected intravenously; subsequently (usually after 45 minutes elapsed time), the amount of dye remaining in the serum is measured; a concentration of 0.4 mg or less of bromsulphalein per 100 ml of serum or less than 4% of the injected dye is considered normal; bromsulphalein retention may follow decreased hepatic blood flow or biliary obstruction as well as hepatic cell damage. SYN: BSP t..
- BSP t. SYN: bromsulphalein t..
- butanol-extractable iodine t. an obsolete t. for thyroid function, applicable in patients who have received large amounts of iodine or iodized products. SYN: BEI t..
- California psychological inventory t. a personality inventory, used with normal persons, in which emphasis is upon social interaction variables.
- CAMP t. a t. to identify Group B β-streptococci based on their formation of a substance (CAMP factor) that enlarges the area of hemolysis formed by streptococcal β-hemolysin. [Christie, Atkins, and Munch-Petersen, developers of the t.]
- cancer antigen 125 t. (CA125) t. for cell-surface antigen found on derivatives of coelomic epithelium. Elevated levels of this antigen are associated with ovarian malignancy and benign pelvic disease such as endometriosis.
- capillary fragility t. a tourniquet t. used to determine the presence of vitamin C deficiency or thrombocytopenia; a circle 2.5 cm in diameter, the upper edge of which is 4 cm below the crease of the elbow, is drawn on the inner aspect of the forearm, pressure midway between the systolic and diastolic blood pressure is applied above the elbow for 15 minutes, and a count of petechiae within the circle is made: 10, normal; 10–20, marginal; more than 20, abnormal. SYN: capillary resistance t., Rumpel-Leede sign, Rumpel-Leede t., vitamin C t..
- carbohydrate utilization t. a t. for the definitive identification of clinically important yeasts and yeastlike organisms.
- carotid sinus t. stimulation of one carotid sinus (never both) to produce reflex effects that may slow the heart, reduce the systolic blood pressure or both for diagnostic or, in the case of certain arrhythmias, therapeutic purposes.
- Carr-Price t. a quantitative t. for vitamin A based on the reaction with antimony trichloride in chloroform.
- Casoni intradermal t. a t. for hydatid disease in which hydatid fluid is injected intracutaneously; immediate or delayed wheal-and-flare reaction is positive. SYN: Casoni skin t..
- CF t. SYN: complement fixation.
- Chick-Martin t. a method of testing the in vitro efficiency of a bactericidal agent; a standard culture of Salmonella typhi which has been added to a fixed amount of sterilized feces or yeast is tested for a fixed period (30 minutes), against various concentrations of phenol solution and various concentrations of the disinfectant; the result is expressed as a ratio : the phenol coefficient, which is the highest dilution of the disinfectant under t. at which the bacteria are killed, divided by the highest dilution of phenol which sterilizes the solution in the same length of time.
- chi-square t. a statistical method of assessing the significance of a difference, as when the data from two or more samples, such as the numbers of females and males attending each of two colleges, are represented by a discrete number. SYN: χ2 t..
- Clauberg t. a t. for progestational activity; immature rabbits are treated with 8 daily injections of estrogen and then given 5 daily injections of the t. substance; the amount required to produce definite progestational changes in the endometrium is taken as the unit; it is equivalent to 0.75 mg of progesterone.
- clonidine growth hormone stimulation t. administration of the α-2 adrenoreceptor agonist clonidine fails to raise growth hormone levels in patients with multiple system atrophy; levels in normal patients increase.
- coccidioidin t. an intracutaneous t. for determining the presence of infection with the fungus Coccidioides immitis; a reaction of delayed hypersensitivity indicates a positive t. and is interpreted as meaning past or present infection with the fungus.
- coin t. SYN: bellmetal resonance.
- cold bend t. a t. of the ability of a wire to be shaped; performed by counting the number of times a wire can be bent to a right angle and reversed at the same point before breaking; important in establishing specifications for orthodontic wires.
- cold pressor t. a cardiocirculatory challenge conventionally performed by immersing one hand in ice-cold water for two or more minutes (as tolerated) to acutely raise the blood pressure, thus imposing resistance to ejection of blood from the left ventricle into the systemic arterial system and consequently acutely increased afterload (afterload = increased left ventricular wall stress). SYN: Hines-Brown t..
- complement-fixation t. an immunologic t. for determining the presence of a particular antigen or antibody when one of the two is known to be present, based on the fact that complement is “fixed” in the presence of antigen and its specific antibody. SEE ALSO: Bordet-Gengou phenomenon.
- Coombs t. a t. for antibodies, the so-called anti–human globulin t. using either the direct or indirect Coombs tests. SYN: antiglobulin t..
- Corner-Allen t. a t. for progestational activity; adult female rabbits are mated during estrus and spayed 18 hours later; the t. substance is injected subcutaneously on 5 successive days; the minimal amount required to produce complete progestational proliferation of the endometrium is taken as a unit, equivalent to 1.25 mg of progesterone.
- cover t. a t. used for objective demonstration of ocular deviation in strabismus; may be performed by two methods: the cover-uncover t. and the alternate cover t..
- cover-uncover t. SYN: alternate cover t..
- CO2-withdrawal seizure t. utilization of hyperventilation to demonstrate abnormalities in the brain waves or even to precipitate a convulsion.
- Crampton t. a t. for physical condition and resistance; a record is made of the pulse and the blood pressure in the recumbent and standing positions, and the difference is graded from the theoretical perfection of 100 (seldom attained) downward (a reading of 75 is considered excellent, 65 poor); high values indicate a good physical resistance but low ones indicate a nonconditioned state.
- tests of criminal responsibility in forensic psychiatry, legal precedents upon which are based decisions concerning insanity in criminals. SEE ALSO: American Law Institute rule, Durham rule, M'Naghten rule, New Hampshire rule.
- cyanide-nitroprusside t. a qualitative t. for diagnosis of cystinuria; the addition of fresh sodium cyanide formed by sodium nitroprusside to a sample of urine gives rise to a stable red-purple color in the presence of cystine.
- cytotropic antibody t. a rosette t. for macrophage cytotropic antibody : monolayers of macrophages are exposed first to antibody cytotropic for macrophages, then to the antigen (for which the antibody is specific), and indicator sheep erythrocytes; if the antibody is specific for sheep erythrocytes, the latter will form a rosette around the macrophages directly, but if not, and the antigen is soluble, the antigen must be coupled to the sheep erythrocytes by an agent such as bis-diazotized benzidine.
- Day t. a t. for blood by the addition of the suspected fluid or the washing of a suspected stain with tincture of guaiac and then hydrogen peroxide; the presence of blood results in a blue color.
- D-dimer t. t. that detects the cross-linked fibrin degradation fragment, D-dimer. Elevations in this fragment are seen in primary and secondary fibrinolysis; during thrombolytic or defibrination therapy with tissue plasminogen activator; as a result of thrombotic disease, such as deep-vein thrombosis, pulmonary embolism or DIC; in vasoocclusive crisis of sickle cell anemia; in malignancies; and in surgery.
- Dehio t. if an injection of atropine relieves bradycardia, the condition is due to action of the vagus; if it does not, the condition may be due to an affection of the heart itself. SYN: atropine t..
- dehydrocholate t. a method of determining the speed of the blood circulation; a solution of sodium dehydrocholate is injected intravenously, and the time that elapses before a bitter taste is noted in the mouth is recorded; the average of this time is normally about 13 sec.
- Denver Developmental Screening T. a scale used by psychologists and pediatricians to assess the developmental, intellectual, motor, and social maturity of children at any age level from birth to adolescence.
- dexamethasone suppression t. a t. for the detection and diagnosis of Cushing syndrome; following administration of 1.0 mg of dexamethasone at 11 p.m., normal persons suppress plasma cortisol to low levels; patients with Cushing syndrome do not. Higher dose regimens distinguish between Cushing syndrome due to tumor and due to hyperplasia.
- Dick t. an intracutaneous t. of susceptibility to the erythrogenic toxin of Streptococcus pyogenes responsible for the rash and other manifestations of scarlet fever. SYN: Dick method.
- differential ureteral catheterization t. a study performed to determine various functional parameters of one kidney compared to the contralateral kidney; ureteral catheters are inserted at cystoscopy into the ureter or renal pelvis bilaterally, and simultaneous measurements are made of urine flow rate, insulin, or PAH (if infused), endogenous creatinine, or various urinary solutes. SYN: differential renal function t., split renal function t..
- dinitrophenylhydrazine t. a screening t. for maple syrup urine disease; the addition of 2,4-dinitrophenylhydrazine in HCl to urine gives a chalky white precipitate in the presence of ketoacids.
- direct Coombs t. a t. for detecting sensitized erythrocytes in erythroblastosis fetalis and in cases of acquired immune hemolytic anemia : the patient's erythrocytes are washed with saline to remove serum and unattached antibody protein, then incubated with Coombs anti-human globulin (usually serum from a rabbit or goat previously immunized with human globulin); after incubation, the system is centrifuged and examined for agglutination, which indicates the presence of so-called incomplete or univalent antibodies on the surface of the erythrocytes.
- discontinuation t. a t. to determine whether a certain drug is responsible for a reaction by observation of a remission of symptoms following cessation of its use.
- Doerfler-Stewart t. examination of the patient's ability to respond to spondee words in the presence of a masking noise of the saw-tooth type; used especially in differentiating between functional and organic hearing loss. SYN: D-S t..
- double (gel) diffusion precipitin t. in one dimension gel diffusion precipitin tests in one dimension.
- double (gel) diffusion precipitin t. in two dimensions gel diffusion precipitin tests in two dimensions.
- Dragendorff t. an obsolete qualitative t. for bile; a play of colors is produced by adding a drop of nitric acid to white filter paper or unglazed porcelain, moistened with a fluid containing bile pigments. The t. is essentially the same as Gmelin t. for bile in urine.
- drawer t. SYN: drawer sign.
- D-S t. SYN: Doerfler-Stewart t..
- Ducrey t. an intradermal t., using inactivated Haemophilus ducreyi, for diagnosis of chancroid; a positive delayed reaction is indicative of present or past infection; false-positive results.
- Duke bleeding time t. a bleeding time t. in which an incision is made in the earlobe and the time until bleeding stops is measured.
- dye disappearance t. SYN: fluorescein instillation t..
- dye exclusion t. a t. to determine cell viability in which a dilute solution of certain dyes ( e.g., trypan blue, eosin Y, nigrosin, Alcian blue) is mixed with a suspension of live cells; cells that exclude dye are considered to be alive while cells that stain are considered dead; it is not always an accurate t. because it indicates only the structural integrity of the cell membrane.
- Ebbinghaus t. a psychological t. in which the patient is asked to complete certain sentences from which several words have been left out.
- Ellsworth-Howard t. measurement of serum and urinary phosphorus after intravenous administration of parathyroid extract; used in the diagnosis of pseudohypoparathyroidism.
- E-rosette t. a t. to identify T lymphocytes by mixing purified blood lymphocytes with serum and sheep erythrocytes; rosettes of erythrocytes form around human T lymphocytes on incubation.
- exercise t. any t. using exercise to determine the patient's solidus responses and/or physical condition.
- Farnsworth-Munsell color t. a t. for color perception; the task is to arrange 84 color disks (in four separate racks of 20–22 disks) in a sequence with minimal separation of hue between adjacent disks.
- fern t. 1. a t. for estrogenic activity; cervical mucus smears form a fern pattern at those times when estrogen secretion is elevated, as at the time of ovulation; similar changes have been reported to occur in saliva; 2. a t. to detect ruptured amniotic membranes.
- ferric chloride t. a qualitative t. for the detection of phenylketonuria; the addition of ferric chloride to urine gives rise to a blue-green color in the presence of phenylketonuria.
- Finckh t. a psychological t. in which the patient is asked to explain certain proverbial expressions, such as “burn the candle at both ends,” “the early bird catches the worm,” etc.
- finger-nose t. a t. of upper limb coordination and position sense; the subject is asked to slowly touch the tip of his or her nose with an extended index finger; assesses cerebellar function.
- finger-to-finger t. a t. for coordination and position sense of the upper limbs; the subject is asked to approximate the ends of the index fingers; assesses cerebellar function.
- Finkelstein t. t. to detect de Quervain tenosynovitis in which the thumb is flexed into the palm and is covered by the remaining four digits; the wrist is then bent toward the ulna; positive result of t. produces pain and crepitus along the path of the involved tendon.
- Fishberg concentration t. a t. of renal water conservation; after overnight fluid deprivation, morning urine samples are collected and specific gravity is measured.
- Fisher exact t. the t. for association in a two-by-two table that is based on the exact distribution of the frequencies within the table.
- fistula t. compression or rarefaction of the air in the external auditory canal excites nystagmus when there is an erosion of the otic capsule, so long as the labyrinth is still capable of functioning.
- FIT t. SYN: fusion-inferred threshold t..
- Fleitmann t. an obsolete t. for arsenic; hydrogen is generated in a t. tube containing the suspected fluid; the fluid is heated and a piece of filter paper moistened with silver nitrate solution is held over the top; if arsenic is present, the moistened paper is blackened.
- flocculation t. flocculation reaction.
- fluorescein instillation t. a t. for patency of the lacrimal system; fluorescein instilled in the conjunctival sac can be recovered from the inferior nasal meatus. SYN: dye disappearance t., Jones t..
- fluorescein string t. an infrequently used t. in which a patient with gastrointestinal bleeding swallows a string; fluorescein is given intravenously; if the string fluoresces after removal, it has been contaminated by blood that has appeared since injection of the fluorescein; used to determine location of bleeding lesion.
- fluorescent antinuclear antibody t., FANA t. a t. for antinuclear antibody components; used, in particular, for the diagnosis of collagen-vascular diseases.
- fluorescent treponemal antibody-absorption t. a sensitive and specific serologic t. for syphilis using a suspension of the Nichols strain of Treponema pallidum as antigen; the presence or absence of antibody in the patient's serum is indicated by an indirect fluorescent antibody technique. SYN: FTA-ABS t..
- foam stability t. a t. for fetal pulmonary maturity, determined by the ability of pulmonary surfactant in amniotic fluid to generate stable foam in the presence of ethanol after mechanical agitation. SYN: shake t..
- Folin t. 1. a quantitative t. for uric acid by means of the color produced with phosphotungstic acid and a base; 2. a quantitative t. for urea; the urea is decomposed by boiling with magnesium chloride, and the freed ammonia is measured.
- Folin-Looney t. an obsolete t. for tyrosine that gives a blue color in alkaline solution with a reagent consisting of sodium tungstate, phosphomolybdic acid, and phosphoric acid.
- formol-gel t. a t. to detect the greatly increased serum proteins in visceral leishmaniasis; one drop of full-strength formalin is added to 1 mL of serum, with rapid and complete coagulation indicating the positive reaction.
- Fosdick-Hansen-Epple t. a t. for determining dental caries activity based on a solution of powdered human enamel in a saliva-glucose-enamel mixture.
- Foshay t. an intradermal t. for cat-scratch disease or tularemia, using material prepared from suppurative lymph node s of persons known to have had the disease (not commercially available).
- fragility t. a t. that measures the resistance of erythrocytes to hemolysis in hypotonic saline solutions; erythrocytes to be tested are added to varying concentrations of saline (usually ranging from 0.85–0.10% sodium chloride with 0.05% increments), and beginning and complete hemolysis are measured; normal erythrocytes show initial hemolysis at concentrations of 0.45–0.39% and complete hemolysis at 0.33–0.30%; in hereditary spherocytosis, the fragility of the erythrocytes is markedly increased, whereas in thalassemia, sickle cell anemia, and obstructive jaundice the fragility of the erythrocytes is usually reduced. SYN: erythrocyte fragility t..
- Frei t. an intracutaneous diagnostic t. for lymphogranuloma venereum: the Frei antigen is usually a sterile preparation of inactivated chlamydiae from domestic fowl; a positive delayed type reaction is not diagnostically specific for lymphogranuloma venereum and is rarely used. SYN: Frei-Hoffmann reaction.
- FTA-ABS t. SYN: fluorescent treponemal antibody-absorption t..
- fusion-inferred threshold t. employment of the phenomenon of cerebral fusion of binaural sounds to substitute for conventional masking in hearing testing. SYN: FIT t..
- Gaddum and Schild t. a sensitive method for identification of epinephrine in tissue or other material, based on the fluorescence of epinephrine exposed to ultraviolet light in the presence of alkali and oxygen; sensitivity ranges from 1:50 to 1:100 million.
- galactose tolerance t. a liver function t., based on the ability of the liver to convert galactose to glycogen, measured by the rate of excretion of galactose following ingestion or intravenous injection of a known amount; normally, less than 3 g appear in the urine within 5 hours after the ingestion of 40 g.
- gel diffusion precipitin tests precipitin tests in which the immune precipitate forms in a gel medium (usually agar) into which one or both reactants have diffused; generally classified in two types, in one dimension and in two dimensions. SYN: gel diffusion reactions.
- gel diffusion precipitin tests in one dimension precipitin tests in which antigen solution and antibody incorporated in agar are layered in tubes, permitting effective diffusion in the vertical dimension; the antibody-containing agar may be overlaid directly with antigen solution (single (gel) diffusion in one dimension).
- gel diffusion precipitin tests in two dimensions precipitin tests made in a layer of agar that permits radial diffusion, in both of the horizontal dimensions, of one or both reactants. Double (gel) diffusionin two dimensions (Ouchterlony t., technique, or method) incorporates antigen and antibody solutions placed in separate wells in a sheet of plain agar, permitting radial diffusion of both reactants; this method is widely used to determine antigenic relationships; the bands of precipitate that form where the reactants meet in optimal concentration are of three patterns, referred to as reaction of identity, reaction of partial identity (cross-reaction), and reaction of nonidentity.
- Gellé t. a vibrating tuning fork is applied over the mastoid process; if it is heard, the air in the external auditory canal is compressed, by means of a rubber tube inserted into the canal and a hand bulb, thereby fixing the stapes in the oval window, and the sound ceases to be heard, but is again perceived if the air pressure is removed; a t. of the mobility of the ossicles.
- Gerhardt t. for acetoacetic acid in fresh urine a red color develops upon addition of FeCl3; no color develops if the urine has first been boiled; this t. has low specificity and sensitivity. SYN: Gerhardt reaction.
- Gerhardt t. for urobilin in the urine the urobilin is extracted with chloroform and then treated with iodine and potassium hydrate, a fluorescent green color being produced.
- germ tube t. a t. for the identification of Candida albicans; after a 3-hour incubation in serum, an inoculum of Candida develops tubelike appendages.
- glucose oxidase paper strip t. a qualitative t. for glucose in the urine, in which glucose is oxidized to gluconic acid by glucose oxidase; a specific t., unless ascorbic acid is present.
- glucose tolerance t. a t. for diabetes, or for hypoglycemic states such as may be seen rarely in patients with insulinomas. Following ingestion of 75 g of glucose while the patient is fasting, the blood sugar promptly rises and then falls to normal within 2 hours; in diabetics, the increase is greater and the return to normal unusually prolonged; in hypoglycemic patients, depressed glucose levels may be observed in 3-, 4-, or 5-hour measurements.
- glycerol dehydration t. transient hearing improvement in some persons with Ménière disease after an oral glycerol dose resulting in an osmotic diuresis.
- Gmelin t. an obsolete t. for bile in the urine or other body fluid; nitric acid, with a little nitrous acid, is carefully added to a few milliliters of the material to be tested; if bile (bilirubin) is present, it is oxidized to varying degrees, thereby resulting in disklike zones that are (from the interface outward) yellow, red, violet, blue, and green; development of green and violet layers is essential to the validity of the t.. SYN: Rosenbach-Gmelin t..
- Gofman t. a t. for various serum lipoproteins that contain cholesterol, as an index of the tendency to the development of atheromatous lesions and arteriosclerosis; the t. is based on the differential flotation of molecules of various sizes when the serum is treated in an ultracentrifuge.
- Goldscheider t. determination of the temperature sense by touching the skin with a sharp-pointed metallic rod heated to varying degrees.
- Goodenough draw-a-man t. a brief t. for assessing an individual's level of intelligence based on how accurately drawn and how many elements are included when a child or adult is given a pencil and sheet of white paper and asked to draw a man, the best man he or she is able to draw. Also called the Goodenough draw-a-person t. and, in its current form, the Goodenough-Harris drawing t..
- goodness of fit t. a statistical t. of the hypothesis that data have been randomly sampled or generated from a population that follows a particular theoretical distribution.
- Graham-Cole t. SYN: cholecystography.
- group t. in psychology, a t. designed to be administered to more than one individual at a time; e.g., scholastic achievement t., medical college admissions t..
- Günzberg t. a t. for hydrochloric acid utilizing phloroglucin vanillin (Günzberg reagent), with which a bright red color is produced in the presence of the acid.
- Guthrie t. bacterial inhibition assay for direct measurement of serum phenylalanine; in widespread use for detection of phenylketonuria in the newborn.
- Gutzeit t. an obsolete t. for arsenic; a piece of zinc and a little sulfuric acid are added to the suspected liquid which is then boiled; a bit of filter paper with a silver nitrate solution is held in the vapor and will turn yellow if arsenic is present.
- Ham t. SYN: acidified serum t..
- Harrington-Flocks t. a rapid screening t. for visual field defects; patterns are viewed tachistoscopically, and the patterns are visible only when illuminated by a flash of ultraviolet light.
- Harris and Ray t. an obsolete t. for vitamin C in the urine; a microtitration t. of the urine against a known amount of 0.05% aqueous solution of the dye 2,6-dichloroindophenol in 10% acetic acid (usually 0.05 mL of dye is used, roughly equivalent to 0.025 mg of ascorbic acid). SYN: Harris t..
- head-dropping t. a t. used in the diagnosis of disease of the extrapyramidal or striatal system ( e.g., parkinsonism, Wilson disease); with the patient supine and relaxed with attention diverted, the examiner briskly lifts the patient's head with the right hand and then allows it to drop upon the palm of the examiner's left hand; the head of a normal person drops suddenly like a dead weight; in striatal disease the head falls slowly, gently, and almost hesitantly.
- heat coagulation t. a t. for measurement of protein in urine; albumin and globulin are coagulated by heat at an acid pH, and the amount of turbidity present provides a qualitative estimation of the degree of proteinuria.
- heat instability t. a t. for the presence of unstable hemoglobins; fresh red blood cells lysed in distilled water develop a precipitate within 1 hour at 50°C if unstable hemoglobin is present.
- heel-tap t. heel tap.
- heel-to-knee-to-toe t. SYN: heel-to-shin t..
- heel-to-shin t. a t. of lower limb coordination and position sense; the subject places the heel of one foot on the opposite knee and then slides it distally along the shin to the opposite ankle. SYN: heel-to-knee-to-toe t..
- Heinz body t. a t. for glucose-6-phosphate dehydrogenase -deficient red blood cells; an oxidant (acetylphenylhydrazine) is added to blood; after incubation at 37°C, glucose-6-phosphate dehydrogenase -deficient samples exhibit more than 30% Heinz bodies.
- hemadsorption virus t. a method for detecting hemagglutinating viruses that is based on adherence of erythrocytes to infected cells.
- hemagglutination t. a sensitive t. to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes.
- Hemoccult t. trade name for a qualitative t. for occult blood in stool based on detecting the peroxidase activity of hemoglobin; a t. kit can be used at home and the specimens (usually 3 collected on sequential days) mailed to a laboratory for evaluation.
- Hering t. a t. of binocular vision; the subject looks through an apparatus having at its far end a thread near which a small sphere is dropped; with binocular vision the observer recognizes the location of the sphere in front of or behind the thread; with monocular vision this is not possible.
- Hershberg t. a t. for anabolic steroids in which castrated male rats are treated with the substance being tested.
- Hinton t. a formerly widely used precipitin (flocculation) t. for syphilis in which the “antigen” consisted of glycerol, cholesterol, and beef heart extract.
- Hirschberg t. a t. of binocular motor alignment by which a penlight is shone at the eyes and the position of the light reflex on the cornea observed, allowing an estimate of the amount of deviation, if present.
- Histalog t. a t. for measurement of maximal production of gastric acidity or anacidity; it is similar to the histamine t., but uses Histalog (betazole hydrochloride), an analog of histamine. SYN: maximal Histalog t..
- histamine t. a t. for maximal production of gastric acidity or anacidity; after preliminary administration of an antihistamine, histamine acid phosphate is injected subcutaneously in a dose of 0.04 mg/kg of body weight, followed by analysis of gastric contents. SEE ALSO: Histalog t.. SYN: augmented histamine t..
- histoplasmin-latex t. a passive agglutination t. for histoplasmosis; latex particles, sensitized with antigen extracted from Histoplasma capsulatum, are used in a flocculation reaction with the patient's serum.
- Holmgren wool t. a t. for color blindness, in which the subject matches variously colored skeins of wool.
- homovanillic acid t. a t. for homovanillic acid based upon the fact that dopamine is present in sympathetic nervous tissue as precursor of norepinephrine; since norepinephrine has a metabolic pathway which yields homovanillic acid, tumors such as neuroblastomas and ganglioneuromas may cause elevations of urinary dopamine and homovanillic acid. SYN: HVA t..
- Howard t. an obsolete t. in which a differential ureteral catheterization is performed by the insertion of bilateral ureteral catheters to measure simultaneous urinary volume and sodium concentration in patients with suspected renovascular hypertension.
- Huhner t. SYN: postcoital t..
- HVA t. SYN: homovanillic acid t..
- 17-hydroxycorticosteroid t. a t., dependent on the Porter-Silber reaction, that is used as a measure of adrenocortical function and is performed on urine. Low values are seen in Addison disease and hypopituitarism; high values are seen in Cushing syndrome and extreme stress. SYN: 17-OH-corticoids t., Porter-Silber chromogens t..
- hyperventilation t. producing respiratory alkalosis by overbreathing to 1) produce clinical abnormalities, e.g., tetany seizures; 2) cause EEG abnormalities; 3) cause EMG abnormalities.
- immunologic pregnancy t. a general term for tests for detection of increased human chorionic gonadotropin in plasma or urine by immunologic techniques including latex particle agglutination, hemagglutination inhibition, radioimmunoassay, radioreceptor assays, and enzyme immunoassays.
- impingement t. diagnostic t. in which local anesthetic is injected into the subacromial space of a patient with impingement signs; relief of pain following the injection during provocative maneuvers is helpful in confirming the subacromial space as the source of the symptoms.
- indirect t. Prausnitz-Küstner reaction.
- indirect Coombs t. a t. routinely performed in cross-matching blood or in the investigation of transfusion reaction : t. for patient's serum is incubated with a suspension of donor erythrocytes; if specific antibodies are present, they become attached to the antigen in the donor cells; after a washing with saline, Coombs antihuman globulin is added; agglutination at this point indicates that antibodies present in the original t. serum had indeed become attached to donor erythrocytes.
- indirect hemagglutination t. SYN: passive hemagglutination.
- indole t. a t. used to identify members of the Enterobacteriaceae family and other Gram-negative bacilli, based on the ability of the organisms to produce indole from tryptophan.
- inkblot t. SYN: Rorschach t..
- insulin hypoglycemia t. an infrequently used t. to determine the completeness of vagotomy; after the surgery, insulin is administered to cause hypoglycemia; if vagotomy is complete, the acid output from the stomach following administration of insulin is substantially less than that before insulin administration; if the level is unchanged, incomplete vagotomy is likely. Complications of hypoglycemia are such that the t. largely has been abandoned. SYN: Hollander t..
- intelligence t. a t., using well-researched items and involving a systematic method of administration and scoring, used to assess an individual's general aptitude or level of potential competence, in contrast to an achievement t..
- intradermal t. SYN: skin t..
- Ishihara t. a t. for color vision deficiency that utilizes a series of pseudoisochromatic plates on which numbers or letters are printed in dots of primary colors surrounded by dots of other colors; the figures are discernible by individuals with normal color vision.
- isopropanol precipitation t. a t. using the principle that the internal bonds of hemoglobin are weakened by nonpolar solvents; thus, unstable hemoglobins will precipitate more rapidly than other hemoglobins in isopropanol.
- 131I uptake t. a t. of thyroid function in which 131I-iodide is given orally; after 24 hours, the amount present in the thyroid gland is measured and compared with normal values. SYN: radioactive iodide uptake t., RAI t..
- Ivy bleeding time t. a bleeding time t. in which a sphygmomanometer is inflated to 40 mm Hg around the upper arm, a 5-mm deep incision is made on the flexor surface of the forearm, and the time is measured to cessation of bleeding.
- Jacquemin t. a t. for phenol; to the suspected fluid an equal amount of aniline is added, and, after thorough admixture, a little solution of sodium hypochlorite; if phenol is present the fluid becomes blue.
- Jaffe t. 1. a quantitative t. for creatinine based on its reaction with alkaline picrate; 2. a qualitative t. for the presence of indicanuria; after an equal amount of HCl is added to the urine, the further addition of chloroform and CaCl2 gives rise to blue or purple chloroform droplets that sink to the bottom if indican is present.
- Janet t. a t. for functional or organic anesthesia; the patient (with eyes closed) is told to say “yes” or “no” on feeling (or not) the touch of the examiner's finger; in the case of functional anesthesia the patient may say “no” when an anesthetic area is touched, but will say nothing, being unaware that he is touched, in cases of organic anesthesia.
- Jolles t. a t. for bile; a precipitate is obtained by agitation with chloroform, a solution of barium chloride, and hydrochloric acid; the precipitate is removed, and the addition of a drop or two of sulfuric acid will produce a play of color if bile pigments are present.
- Jones II t. SYN: secondary dye t..
- 17-ketogenic steroid assay t. a colorimetric t., based on the Zimmermann reaction, which indicates metabolites or adrenal and testicular steroids excreted as 17-ketones in the urine; increased values are most striking in adrenocortical tumors, decreased values in Addison disease or in panhypopituitarism. SYN: ketogenic corticoids t..
- Kober t. a t. for naturally occurring estrogens, based upon the production of a pink color (absorption maximum : 520 μm) when an estrogen is heated in a mixture of phenol and sulfuric acid.
- Kolmer t. a former standard quantitative method for the Wassermann t., with numerous modifications (especially as to antigen).
- Korotkoff t. a t. of collateral circulation; while the artery above an aneurysm is compressed, the blood pressure in the distal circulation is estimated; if it is fairly high, the collateral circulation is good.
- Krimsky t. a t. of binocular motor alignment by which a penlight is shone at the eyes and the position of the light reflex centered with a prism, thus indicating the amount of deviation.
- Kurzrok-Ratner t. a t. for estrogens in the urine; the urine is extracted with ethyl acetate and, after purification, the extract is subjected to bioassay as in the Allen-Doisy t..
- Kveim t. an intradermal t. for the detection of sarcoidosis, done by injecting Kveim antigen (obtained from spleens of persons with sarcoidosis) and examining skin biopsies after 3 and 6 weeks; a positive t. is indicated by typical nodules showing evidence of sarcoid tissue. SYN: Kveim-Siltzbach t., Nickerson-Kveim t..
- Kveim-Siltzbach t. SYN: Kveim t..
- Lachman t. a maneuver to detect deficiency of the anterior cruciate ligament; with the knee flexed 20–30°, the tibia is displaced anteriorly relative to the femur; a soft endpoint or greater than 4 mm of displacement is positive (abnormal).
- Lancaster red green t. t. to measure ocular deviations in various fields of gaze in adult patients with acquired strabismus and diplopia by placing a red filter over the right eye and a green filter over the left eye followed by alignment by the patient of a red or green light with light of opposite color projected by the examiner.
- Landsteiner-Donath t. Donath-Landsteiner phenomenon.
- Lange t. an obsolete, nonspecific t. for altered proteins in spinal fluid. As originally used by Lange in 1912, the t. was thought to be specific for neurosyphilis; however, this proved to be incorrect. Dilutions of spinal fluid are made in saline and to these a colloidal gold solution is added; if altered proteins are present, there is a color change or precipitate formed. SYN: gold sol t., Zsigmondy t..
- latex agglutination t. a passive agglutination t. in which antigen is adsorbed onto latex particles which then clump in the presence of antibody specific for the adsorbed antigen. SYN: latex fixation t..
- LE cell t. in vitro incubation of blood or bone marrow of patients with systemic lupus erythematosus, or action of their serum on normal leukocytes, causes formation of characteristic LE cells. SYN: lupus erythematosus cell t..
- Legal t. a t. for acetone; the urine is rendered alkaline by a few drops of a solution of potassium hydroxide, and to this are added 2 or 3 drops of a freshly prepared 10% solution of sodium nitroprusside; it is colored red, then yellow; then a few drops of acetic acid are trickled down the side of the t. tube and at the line of junction of the two fluids is formed a carmine or purple ring.
- leishmanin t. a delayed hypersensitivity t. for cutaneous leishmaniasis; a positive t. when granulomatous induration exceeds 5 min after 2–3 days at the intradermal injection site of a suspension of leishmanias in phenol. SYN: Montenegro t.. [leishmania + suffix -in, component, derivative]
- lepromin t. a t. utilizing an intradermal injection of a lepromin, such as the Dharmendra antigen or Mitsuda antigen, to classify the stage of leprosy based on the lepromin reaction, such as the Fernandez reaction or Mitsuda reaction; it differentiates tuberculoid leprosy, in which there is a positive delayed reaction at the injection site, from lepromatous leprosy, in which there is no reaction ( i.e., a negative t. result) despite the active malignant Mycobacterium leprae infection; the t. is not diagnostic, since normal uninfected persons may react.
- leukocyte adherence assay t. a t. to detect the ability of leukocytes to adhere to bacteria, performed in vitro using nylon fibers to measure adherence.
- leukocyte bactericidal assay t. a t. of leukocytes to determine their ability to kill a culture of live bacteria.
- Liebermann-Burchard t. a colorimetric t. for unsaturated sterols, notably cholesterol; a blue-green color develops when such substances are added to acetic anhydride and sulfuric acid in chloroform.
- limulus lysate t. a t. for the rapid detection of Gram-negative bacterial meningitis; Gram-negative endotoxin induces gel formation of Limulus polyphemus (horseshoe crab) lysates.
- line t. a t. for rickets, based on observation of the lines of calcification in the growing ends of rachitic long bones in rats given vitamin D preparations under standard t. conditions; used in biological assay of vitamin D by the USP.
- lipase t. a diagnostic t. based on the measurement of lipase in blood and urine as an indicator of pancreatic disease.
- Lombard voice-reflex t. the observation of fluctuations in the intensity of a patient's voice when a masking noise is increased or decreased; a t. useful in assessing functional hearing loss.
- Lücke t. a t. for hippuric acid; hot nitric acid is added to the urine and evaporated to dryness; the presence of hippuric acid is indicated by an odor of nitrobenzol upon further heating.
- lupus band t. a direct immunofluorescent technique for demonstrating a band of immunoglobulins at the dermal-epidermal junction of the skin of patients with lupus erythematosus.
- Machado-Guerreiro t. a complement-fixation t. for infection with Trypanosoma cruzi.
- Mantoux t. tuberculin t..
- Marshall t. manual deviation of bladder neck during strain or cough to ascertain presence of stress urinary incontinence. SYN: Bonney t., Marshall-Marchetti t..
- Master t. an early and long-used exercise challenge to identify ischemic heart disease using a pair of 9-inch steps with a platform on top, the number of trips by the patient arbitrarily chosen and related to age and body weight. SEE ALSO: two-step exercise t.. SYN: Master two-step exercise t..
- maximal Histalog t. SYN: Histalog t..
- Mazzotti t. a t. for onchocerciasis using an oral t. dose of diethylcarbamazine (50 or 100 mg), resulting in the appearance of an acute rash in 2–24 hours from death of microfilariae in the skin. SYN: Mazzotti reaction.
- McPhail t. an obsolete t. for progesterone and like substances; immature female rabbits are treated with 150 IU of estrone over a period of 6 days; the t. material is then given in five daily subcutaneous doses; progestational proliferation of the endometrium is noted and the results estimated according to a scale from 0 to ++++; the amount required to produce an average (++) response is taken as a unit, equivalent to 0.25 mg of progesterone.
- Meinicke t. the first successful application (1917–1918) of immune precipitation to diagnose syphilis, now obsolete.
- Meltzer-Lyon t. a t. used in diagnosis of gallbladder conditions: 25 ml of a 25% solution of magnesium sulfate are delivered into the region of the sphincter of Oddi through a duodenal tube, causing contraction of the gallbladder, relaxation of the sphincter, and the expulsion of bile from the common duct and gallbladder; bile from the common duct is relatively pale and is expelled first, that from the gallbladder follows; samples aspirated from the tube are examined for pus cells, pigment granules, epithelial cells, cholesterol, etc.
- metabisulfite t. a t. for sickle cell hemoglobin (Hb S); deoxygenation of cells containing Hb S is enhanced by addition of sodium metabisulfite to the blood, causing sickling visible on a slide; certain other abnormal hemoglobins (Hb CHarlem and Hb I) also sickle in this t..
- methacholine challenge t. a t. that involves the inhalation of increasing concentrations of methacholine, a potent bronchoconstrictor, in patients with possible bronchial hyperreactivity; usually performed when a diagnosis of asthma or bronchospastic lung disease is not clinically obvious.
- 3-methoxy-4-hydroxymandelic acid t. SYN: vanillylmandelic acid t..
- metrotrophic t. an obsolete t. for the assay of estrogenic substances; immature female rats (25–49 g) are injected subcutaneously with the hormone and killed after 6 hours, when the increase in uterine weight (due largely to imbibation of water) is taken as the criterion of estrogenic activity. SYN: Astwood t..
- MHA-TP t. SYN: microhemagglutination-Treponema pallidum t..
- microhemagglutination-Treponema pallidum t. a microtiter version of the Treponema pallidum hemagglutination t.. SYN: MHA-TP t..
- microprecipitation t. a precipitation t. in which reduced quantities of t. reagents are used.
- migration inhibitory factor t. a t. which measures the presence of migration inhibitory factor, a 25-kD lymphokine. Usually peritoneal macrophages are placed in a capillary tube in the presence or absence of supernatants from activated T cells in response to immunogenic challenge. If MIF is present, the migration of monocyte/macrophages is reduced. SYN: macrophage migration inhibition t., migration inhibition t..
- milk-ring t. a special form of agglutination t. done on the pooled milk of many cows, usually entire herds, for the detection of herds containing individuals infected with bovine brucellosis.
- Millon Clinical Multiaxial Inventory t. a paper and pencil t., consisting of 20 clinical scales derived from 175 self-descriptive statements, and developed in 1977 for use in the assessment of psychopathology and the more enduring patterns of personality; specifically designed to correspond with some of the disorders of personality included in the Diagnostic and Statistical Manual of Mental Disorders used in diagnosis by mental health professionals. SYN: Millon clinical multiaxial inventory.
- Millon-Nasse t. a t. for protein, the tyrosine of which reacts with nitrite after a brief treatment with mercuric ion in acid to give a color.
- Minnesota Multiphasic Personality Inventory t. (MMPI) a questionnaire type of psychological t. for ages 16 and over, with 550 true-false statements coded in 4 validity and 10 personality scales which may be administered in both an individual or group format. SYN: Minnesota Multiphasic Personality Inventory.
- mixed agglutination t. mixed agglutination reaction.
- mixed lymphocyte culture t. a t. for histocompatibility of HL-A antigens in which donor and recipient lymphocytes are mixed in culture; the degree of incompatibility is indicated by the number of cells that have undergone transformation and mitosis, or by the uptake of radioactive isotope-labeled thymidine. SYN: MLC t..
- MLC t. SYN: mixed lymphocyte culture t..
- Molisch t. a color t. for sugar, which condenses with α-naphthol or thymol in the presence of strong sulfuric acid, which converts the sugar to furfural derivatives.
- Moloney t. a t. to detect a high degree of sensitivity to diphtheria toxoid; more than a minimal local reaction to diluted (1:20) toxoid given intradermally indicates that prophylactic toxoid should be inoculated in fractional doses at suitable intervals.
- Montenegro t. SYN: leishmanin t..
- Mörner t. 1. for cysteine, which gives a brilliant purple color with sodium nitroprusside; 2. for tyrosine, which gives a green color on boiling with sulfuric acid containing formaldehyde.
- Moschcowitz t. demonstration of lower limb ischemia by occlusion of the arterial circulation for 5 min with a tourniquet or Esmarch bandage. Following release, skin color normally will return in a few seconds; with arterial obstruction ( e.g., arteriosclerotic) color returns more slowly.
- Mosenthal t. an infrequently used t. to evaluate renal concentrating ability by measuring the density of urine every 2 hours during the ingestion of a controlled diet.
- motility t. a t. based on microscopic observation or on the spread of growth in soft agar, used to determine if a microorganism is motile.
- Motulsky dye reduction t. a t. for glucose-6-phosphate dehydrogenase deficiency in the blood, using a mixture of brilliant cresyl blue, glucose 6-phosphate, and NADP.
- mucin clot t. a t. that reflects the polymerization of synovial fluid hyaluronate; a few drops of synovial fluid added to acetic acid form a clot; poor clot formation occurs in a variety of inflammatory conditions including septic arthritis, gouty arthritis, and rheumatoid arthritis. SYN: Ropes t..
- Mulder t. xanthoprotein reaction.
- multiple sleep latency t. a t. of the propensity to fall asleep, done by performing polysomnography during multiple brief opportunities to sleep.
- mumps sensitivity t. a skin t. for sensitivity to mumps, in which inactivated mumps virus is used as antigen.
- Nagel t. a t. for color vision in which the observer determines the relative amounts of red and green necessary to match spectral yellow; an instrument called Nagel anomaloscope is used.
- NBT t. abbreviation for nitroblue tetrazolium t..
- neutralization t. SYN: protection t..
- niacin t. a t. of the ability of mycobacteria to elaborate niacin; used to distinguish Mycobacterium tuberculosis from other strains.
- nitroblue tetrazolium t. (NBT t.) a t. to detect the phagocytic ability of polymorphonuclear leukocytes by measuring the capacity of the oxygen-dependent leukocytic bactericidal system.
- nitroprusside t. a qualitative t. for cystinuria; following the addition of sodium cyanide to the urine, the further addition of nitroprusside produces a red-purple color if the cyanide has reduced any cystine present to cysteine.
- nonstress t. a t. to evaluate fetal well-being by evaluating fetal heart rate response to fetal movement; a reactive nonstress t. is fetal heart rate acceleration in response to fetal movement.
- Ober t. t. to evaluate a tight, contracted, or inflamed iliotibial tract; the patient lies on the uninvolved side and the involved hip is abducted by the examiner as the knee is flexed to 90°; the hip is allowed to adduct passively; the degree of abduction or the production of pain along the iliotibial tract can assist in identifying the location of the inflammation or contracture.
- Obermayer t. a t. for indican; solids in the urine are precipitated by means of a 20% solution of acetate of lead and then filtered, and to the filtrate is added fuming hydrochloric acid containing a small amount of ferric chloride solution; if indican is present, the addition of chloroform causes the formation of indigo, indicated by the blue color.
- 17-OH-corticoids t. SYN: 17-hydroxycorticosteroid t..
- oral lactose tolerance t. a t. for lactose deficiency; the plasma glucose response to an oral lactose load is measured as in the (oral) glucose tolerance t..
- Ouchterlony t. double (gel) diffusion t. in two dimensions. See gel diffusion precipitin tests in two dimensions. SYN: Ouchterlony method.
- oxidase t. a t. for the presence of intracellular cytochrome oxidase based on the reaction with p-phenylenediamine; aids in the identification of Neisseria species and Pseudomonadaceae.
- oxytocin challenge t. a contraction stress t. accomplished by administration of intravenous dilute oxytocin solution to stimulate contractions. SYN: contraction stress t..
- Pachon t. in a case of aneurysm, determination of the collateral circulation by estimation of the blood pressure.
- Palmer acid t. for peptic ulcer in duodenal ulcer, the administration of acid by duodenal tube causes severe pain.
- palmin t., palmitin t. a t. of pancreatic efficiency, based upon the fact that the presence of fat in the stomach causes the pylorus to open and admit the pancreatic juice; this splits the palmin so that an examination of the stomach contents, after a t. meal containing palmin, will reveal the presence of fatty acid s.
- Pap t. microscopic examination of cells exfoliated or scraped from a mucosal surface after staining with Papanicolaou stain; used especially for detection of cancer of the uterine cervix. SYN: Papanicolaou smear t..
- Papanicolaou smear t. SYN: Pap t..
- parallax t. measurement of the deviation in strabismus by the alternate cover t. combined with neutralization of the deviation using prisms.
- parametric t. a statistical t. that depends on an assumption about the distribution of the data, e.g., that the data are normally distributed.
- passive cutaneous anaphylaxis t. an animal is injected intradermally with antibody (usually IgE) and subsequently challenged intravenously with a mixture of antigen and Evans blue dye 24–48 hours later. A dark blue area indicates a positive reaction due to the leakage of the dye at the site of antigen-antibody reactions.
- patch t. a t. of skin sensitiveness: a small piece of paper, tape, or a cup, wet with nonirritating diluted t. fluid, is applied to skin of the upper back or upper outer arm and after 48 hours the covered is compared with the uncovered surface; an erythematous reaction with vesicles occurs if the substance causes contact allergy. SEE ALSO: photo- patch t..
- Patrick t. a t. to determine the presence or absence of sacroiliac disease; with the patient supine, the hip and knee are flexed and the external malleolus is placed above the patella of the opposite leg; this can ordinarily be done without pain, but, on depressing the knee, pain is promptly elicited in sacroiliac disease.
- Paul-Bunnell t. t. for detection of heterophil antibodies in infectious mononucleosis. See Forssman antigen.
- pentagastrin t. an alternative to histamine for stimulation of acid secretion in gastric analysis.
- performance t. a t., such as five of the eleven Wechsler adult intelligence scale subtests, requiring little or no verbal instruction from the examiner and virtually no verbal response by the examinee.
- personality t. any of the category of psychological tests designed to t. the characteristics of the personality, emotional status, mental disorder, etc., in contrast to an intelligence t..
- Perthes t. a t. for patency of the deep femoral vein; with the patient standing, a tourniquet is applied above the knee; after walking, if the deep circulation is competent, the superficial varicosities remain unchanged; if the deep circulation is occluded, the legs become painful.
- phentolamine t. a t. for pheochromocytoma; intravenous administration of phentolamine (5 mg) reduces hypertension due to a pheochromocytoma but not that due to other causes, e.g., essential hypertension; the blood pressure is raised by the drug in the latter form of hypertension.
- photo- patch t. a t. of contact photosensitization : after application of a patch with the suspected sensitizer for 48 hours to two sites, if there is no reaction, one area is exposed to a weak erythema dose of sunlight or ultraviolet light; if positive, a more severe reaction with vesiculation develops at the exposed patch area than the nonexposed skin patch site.
- photostress t. measurement of visual acuity before and after exposure of the eyes to intense light.
- phrenic pressure t. pressure is applied on the phrenic nerve on each side, above the clavicles where the nerve passes over the scalenus anticus muscle; if pain is felt and the patient inclines the head to the painful side, the problem is in the pleural space; if the head does not incline to one side, the problem is in the abdominal cavity.
- Pirquet t. a cutaneous tuberculin t.. See tuberculin t.. SYN: dermotuberculin reaction, Pirquet reaction.
- pivot shift t. a maneuver to detect a deficiency of the anterior cruciate ligament of the knee; when the knee is extended, a sudden subluxation of the lateral tibial condyle upon the distal femur is positive.
- P-K t. SYN: Prausnitz-Küstner reaction.
- plasmacrit t. a serologic screening method used as an aid in the diagnosis of syphilis; after only a few drops of heparinized blood (obtained from a pricked finger) are collected in a special capillary tube, the capillary tube is centrifuged in order to collect plasma, which is then mixed with a 0.01-ml drop of antigen (cardiolipin previously treated with choline chloride as an antiinhibitor, in order to avoid falsely negative results that may occur with nonheated plasma or serum). After mechanically agitating the antigen-plasma mixture for 4 min, the presence or absence of flocculation is observed. A positive result should not be regarded as conclusively diagnostic, but a negative result excludes the likelihood of syphilis.
- platelet aggregation t. a t. of the ability of platelets to adhere to each other and hence form a hemostatic plug to prevent bleeding; failure to aggregate occurs in several conditions, e.g., thrombasthenia, Von Willebrand disease, and following administration of aspirin, phenylbutazone, and indomethacin; the t. is conducted by quantitating the decrease in turbidity that occurs in platelet-rich plasma following the in vitro addition of one or several platelet-aggregating agents ( e.g., ADP, epinephrine, or serotonin).
- polyuria t. SYN: Albarran t..
- Porges-Meier t. an early flocculation t. for syphilis; of significance in having introduced as antigens acetone-insoluble, alcohol-soluble fractions of tissue, and lecithin.
- Porter-Silber chromogens t. SYN: 17-hydroxycorticosteroid t..
- postcoital t. a t. on cervical mucus about time of ovulation to evaluate its receptivity to sperm. SYN: Huhner t..
- precipitation t. SYN: precipitin t..
- precipitin t. an in vitro t. in which antigen is in soluble form and precipitates when it combines with added specific antibody in the presence of an electrolyte. SEE ALSO: gel diffusion precipitin tests, ring precipitin t.. SYN: precipitation t..
- primary dye t. assessment of lacrimal drainage following the fluorescein instillation t. by attempting to recover fluorescein dye beneath the inferior turbinate using a swab. SYN: Jones I t..
- prism cover t. measurement of the deviation in strabismus by the alternate cover t. combined with neutralization for the deviation using prisms.
- prism vergence t. measurement of the amplitude of fusion by placing prisms of gradually increasing power in the direction tested until diplopia occurs.
- progesterone challenge t. administration of a progestational agent in case of amenorrhea to detect the presence of an estrogen-primed endometrium.
- projective t. a loosely structured psychological t. containing many ambiguous stimuli that require the subject to reveal feelings, personality, or psychopathology in response to them; e.g., Rorschach t., thematic apperception t..
- protection t. a t. to determine the antimicrobial activity of a serum or to identify a given organism by inoculating a susceptible animal or cell culture with a mixture of the serum and the virus or other microbe being tested. SYN: neutralization t..
- protein-bound iodine t. a formerly used t. of thyroid function in which serum protein-bound iodine is measured to provide an estimate of hormone bound to protein in peripheral blood. SYN: PBI t..
- prothrombin t. a quantitative t. for prothrombin in the blood based on the clotting time of blood plasma in the presence of thromboplastin and calcium chloride; measures the integrity of the extrinsic and common pathways of coagulation. SEE ALSO: prothrombin time. SYN: Quick method, Quick t..
- prothrombin and proconvertin t. a t. formerly used by some to control anticoagulant therapy with bishydroxycoumarin and indandione drugs.
- provocative t. any procedure in which a suspected pathophysiological abnormality is deliberately induced by manipulating conditions known to provoke the abnormality.
- provocative Wassermann t. an obsolete t. of historical interest only; the use of the Wassermann t. from one or two days to one or two weeks after the administration of arsphenamine or neoarsphenamine; the result may then be positive when before the giving of arsphenamine it was negative.
- psychological tests tests designed to measure a person's achievements, intelligence, neuropsychological functions, skills, personality, or individual and occupational characteristics or potentialities. SEE ALSO: scale.
- psychomotor tests psychological tests which, although based on other psychological processes ( e.g., sensory, perceptual), require a motor reaction such as copying designs, building with blocks, or manipulating controls.
- Q tip t. a t. for determining the mobility of the urethra.
- Queckenstedt-Stookey t. compression of the jugular vein in a healthy person causes an increase in the pressure of the spinal fluid in the lumbar region within 10–12 sec, and an equally rapid fall to normal on release of the pressure on the vein; when there is a block of subarachnoid channels, compression of the vein causes little or no increase of pressure in the cerebrospinal fluid.
- Quick t. SYN: prothrombin t..
- Quinlan t. a t. for bile; when a thin layer of bile is examined through a spectroscope, absorption lines appear in the violet.
- radioallergosorbent t. (RAST) a radioimmunoassay t. to detect specific IgE antibodies responsible for hypersensitivity : the allergen is bound to insoluble material and the patient's serum is reacted with this conjugate; if the serum contains antibody to the allergen, it will be complexed to the allergen. Radiolabeled anti-human IgE antibody is added where it reacts with the bound IgE. The amount of radioactivity is proportional to the serum IgE.
- radioimmunosorbent t. (RIST) a competition t., performed in vitro, used to measure IgE specific for a particular antigen. Known amounts of radiolabeled IgE compete with the patient's unlabeled IgE to bind to a surface coated with anti-IgE. The reduction in radiolabeled IgE due to the presence of IgE in the patient's serum can be determined by comparison to known IgE standards; thus, the amount of the patient's total serum IgE can be determined.
- RAI t. SYN: 131I uptake t..
- rapid plasma reagin t. a group of serologic tests for syphilis in which unheated serum or plasma is reacted with a standard t. antigen containing charcoal particles; positive tests yield a flocculation. A modification, called the RPR (circle) card t., is widely used as a screening t.. SYN: RPR t..
- Rapoport t. a differential ureteral catheterization t. used to evaluate suspected renovascular hypertension; urine specimens from each kidney are obtained by bilateral ureteral catheterization, and the tubular rejection fraction ratio is determined by measuring concentrations of sodium and creatinine in the urine from each kidney.
- Reinsch t. a t. for arsenic in which a strip of copper is placed in the suspected fluid, which is then acidulated with hydrochloric acid and boiled; if arsenic is present a gray deposit occurs on the copper, and this deposit on heating is sublimated and deposited as a crystalline layer on a piece of glass held above the copper strip.
- Reiter t. a complement-fixation t. for syphilis using as antigen material prepared from the Reiter strain of Treponema pallidum; the t. has been largely replaced in laboratory medicine by the fluorescent treponemal antibody-absorption (FTA-ABS) t..
- relocation t. a t. for anterior shoulder instability; the supine patient's humerus is abducted and rotated externally against the table edge as a fulcrum; patients with anterior stability loss become apprehensive with pressure.
- resorcinol t. a t. for fructosuria; fresh urine treated with resorcinol in acid gives a red precipitate in the presence of fructose; the precipitate should form a red solution in ethanol. SYN: Selivanoff t..
- Reuss t. a t. for atropine; the addition of oxidizing agents and sulfuric acid to a liquid containing atropine produces an odor of orange-flowers and roses.
- Rh blocking t. a t. for nonagglutinating Rh antibodies: an Rh agglutination t. is first carried out; if the t. for Rh agglutinins is negative, then 1 drop of anti-Rho agglutinating serum of moderate titer is mixed with the patient's serum containing Rh-positive t. cells; if after incubating for from 1–2 hr at 37°C no agglutination occurs, Rho-blocking antibodies are assumed to be present in the patient's serum.
- Rickles t. a colorimetric t. for predicting dental caries activity by incubating saliva in sucrose and determining pH changes.
- Rimini t. an obsolete t. for formaldehyde in urine, milk, and other fluids, by the use of dilute solution of phenylhydrazine hydrochloride, sodium nitroprusside, and sodium hydroxide.
- ring precipitin t. a precipitin t. in which antigen solution is carefully layered over antibody solution in a tube; as diffusion proceeds, a disk of precipitate forms where the antibody ratio is optimal. SYN: ring t..
- Rinne t. 1. a vibrating tuning fork is held in contact with the skull (usually the mastoid process) until the sound is lost, its prongs are then brought close to the auditory orifice when, if the hearing is normal, a faint sound will again be heard; expressed as air conduction greater than bone conduction and indicative of a normal sound conducting mechanism through the middle ear; 2. a vibrating tuning fork is heard longer and louder when in contact with the skull than when held near the auditory orifice, expressed as bone conduction greater than air conduction, indicating some disorder of the sound conducting mechanism.
- Römer t. a t. of historical interest: tuberculin, either pure or diluted, is injected intracutaneously into a guinea pig; if the animal is tuberculous, a large papule with a necrotic hemorrhagic center appears in about 24 hours (cocarde or cockade reaction).
- Rorschach t. a projective psychological t. in which the subject reveals his or her attitudes, emotions, and personality by reporting what is seen in each of 10 inkblot pictures. SYN: inkblot t..
- rose bengal radioactive (131I) t. a t. of liver function used as a means of measuring hepatic blood flow and for scintillation scanning of the liver to determine size and contour of the liver, or the presence of space-occupying masses in the liver.
- Rosenbach t. an obsolete t. for bile in the urine; the suspected urine is passed several times through the same filter paper, which is then dried and touched with a drop of slightly fuming nitric acid; the presence of bile is indicated by the resulting play of colors characteristic of the bile pigments (a yellow spot surrounded by rings of red, violet, blue, and green).
- rosette t. a t. for rosette-forming cells (T lymphocytes) in which these cells and sheep erythrocytes are incubated and centrifuged lightly, then examined under a microscope for rosette formation or adherence of erythrocytes to T lymphocytes.
- Rose-Waaler t. a t. of historical interest: when sheep red cells are coated with a concentration of antiserum to sheep red cells which is too low to cause agglutination, the addition of serum from a patient with rheumatoid arthritis will cause agglutination.
- Ross-Jones t. an obsolete t. for an excess of globulin in the cerebrospinal fluid; 1 ml of cerebrospinal fluid is carefully floated over 2 ml of a concentrated ammonium sulfate solution; if globulin is present in excess, a fine white ring appears at the line of junction in about 3 min.
- Rothera nitroprusside t. a t. for ketone bodies; 5 ml of fresh urine are saturated with solid ammonium sulfate and mixed with 10 drops of freshly prepared 2% sodium nitroprusside solution, which is then mixed with 10 drops of concentrated ammonia water and allowed to stand for 15 min; the presence of acetoacetic acid, or of larger concentrations of acetone, is indicated by the development of a blue-purple color.
- rubella HI t. a hemagglutination inhibition (HI) t. for rubella, often performed routinely as part of a prenatal workup of the pregnant woman; the presence of a detectable HI titer in the absence of disease indicates previous infection and immunity to reinfection; if HI antibody is undetected, the patient is considered potentially susceptible and is followed accordingly. SEE ALSO: hemagglutination inhibition.
- Rubin t. an obsolete t. of patency of the fallopian tubes; a cannula is introduced into the cervix uteri, and carbon dioxide gas is passed through the cannula by means of a syringe with manometer attachment; if the tubes are patent, the escape of gas into the abdominal cavity is evidenced by a high-pitched bubbling sound heard on auscultation over the lower abdomen, or free gas under the diaphragm can be demonstrated by x-ray.
- Rubner t. an obsolete t. for lactose or glucose in the urine; lead acetate is added to the suspected urine which is then filtered; ammonia is added until a permanent precipitate is formed; if lactose is present, the precipitate will take on a pink to red color when the fluid is heated; if there is glucose, the color will be yellow to brown.
- Sabin-Feldman dye t. a method for the detection of antitoxoplasma antibody in serum, based on the fact that Toxoplasma gondii cells (from peritoneal exudate in mice) are fairly well stained with alkaline methylene blue, whereas organisms in a serum that contains specific antibody have no affinity for the dye; furthermore, normal toxoplasma cells become rounded, and the nucleus and cytoplasm deeply stained, when treated with methylene blue; on the other hand, when dye is mixed with organisms and antibody, the cells retain their crescent shape and only the shrunken nuclear endosome is stained.
- Sachs-Georgi t. the first precipitin t. for syphilis of diagnostic practicality, the significant innovation having been the addition of cholesterol to the lipoidal antigen (alcoholic tissue extract) used in the earlier Meinicke t..
- Saundby t. a t. for blood in the stool; on the addition of 30 drops of a 20-volume hydrogen peroxide solution to a mixture of 10 drops of a saturated benzidine solution and a small quantity of feces in a t. tube, a persistent dark blue color denotes the presence of blood.
- scarification t. a t., e.g., Pirquet t., in which a material is pricked or scratched into the skin.
- Schaffer t. a t. for nitrites in the urine; urine is decolorized with animal charcoal and then 4 ml of a 10% solution of acetic acid and 3 drops of a 5% solution of potassium ferrocyanide are added; if nitrites are present, an intense yellow color will be produced.
- Schellong t. a t. for circulatory function; the subject is required to stand for 10–20 min, during which time the blood pressure is measured continuously; a fall of systolic pressure of 20 mm Hg or more indicates poor circulatory function.
- Schick t. a t. for susceptibility to Corynebacterium diphtheriae toxin : 0.1 ml of Schick t. toxin is injected into the skin of one forearm (t. site) and the same quantity of the same, but heat-inactivated, material into the skin of the other forearm (control site); individuals with toxin-neutralizing antibodies either will have no reaction at either injection site (negative t.) or may have a pseudoreaction due to antibodies for substances (antigens) in the t. materials other than diphtheria toxin; individuals lacking toxin-neutralizing antibodies may have a positive reaction, which consists of an area of redness appearing 24–36 hours at the t. site only and persisting for 4–5 days. SYN: Schick method.
- Schiller t. a t. for nonglycogen-containing areas of the portio vaginalis of the cervix, which may be the site of early carcinoma; such areas fail to stain dark brown with iodine solution; loss of glycogen due to erosion and other benign conditions may also give a positive result.
- Schilling t. a procedure for determining the amount of vitamin B12 excreted in the urine using cyanocobalamin tagged with a radioisotope of cobalt.
- Schirmer t. a t. for tear production using a strip of filter paper; a measurement of basal and reflex lacrimal gland function.
- Schober t. a measure of lumbar spine motion in which parallel horizontal lines are drawn 10 cm above and 5 cm below the lumbosacral junction in the erect subject; with maximum forward flexion, the distance between the lines increases at least 5 cm in normal patients but far less in patients with anklylosing spondylitis.
- Schönbein t. SYN: Almén t. for blood.
- Schwabach t. a series of five tuning forks of different tones is used and the number of seconds is noted in which the patient can hear each by air and bone conduction.
- screening t. any testing procedure designed to separate people or objects according to a fixed characteristic or property, with the intention of detecting early evidence of disease.
- Seashore t. a t. in which the individual must discriminate between two sounds; or in which the sense of pitch, intensity, rhythm, and other components of innate musical ability can be measured. See Halstead-Reitan battery.
- secondary dye t. localization of lacrimal drainage obstruction following the fluorescein instillation and primary dye tests by intubating the lower punctum and canaliculus and irrigating with saline. SYN: Jones II t..
- secretin t. a t. of pancreatic exocrine function, variably performed and standardized, in which the bicarbonate, amylase, and volume of the duodenal aspirate are measured after intravenous administration of secretin.
- Selivanoff t. SYN: resorcinol t..
- shadow t. SYN: retinoscopy.
- sickle cell t. in an anaerobic wet preparation containing equal amounts of blood and 2% sodium bisulfite, erythrocytes containing hemoglobin S undergo a change in shape to a sickle cell form; the number of sickled red cells per 1000 red blood cells is determined and expressed as a percentage.
- single (gel) diffusion precipitin t. in one dimension gel diffusion precipitin tests in one dimension.
- single (gel) diffusion precipitin t. in two dimensions gel diffusion precipitin tests in two dimensions.
- situational t. in psychology and psychiatry, a t. situation in which a subject is observed as he or she performs a task or an actual sample of the job or role to be performed; e.g., a t. used to select people for the Office of Strategic Services during the Second World War and for managerial positions today.
- skin t. a method for determining induced sensitivity (allergy) by applying an antigen (allergen) to, or inoculating it into, the skin; induced sensitivity (allergy) to the specific antigen is indicated by an inflammatory reaction of one of two general kinds: 1) immediate, appears in minutes and is dependent upon circulating immunoglobulins (antibodies); 2) delayed, appears in 12–48 hours and is not dependent upon these soluble substances but upon cellular response and infiltration. SYN: cutaneous t., intradermal t., skin reaction.
- skin-puncture t. t. for Behçet syndrome; after pricking the skin with a sterile needle, pustulation follows within 24 hours, owing to the dermal sensitivity in this disease.
- small increment sensitivity index t. (SISI t.) the sounding of a tone 20 dB above threshold, followed by a series of 200–msec tones 1 dB louder; perception of these is indicative of cochlear damage; the percentage of small increments detected by the subject is the small increment sensitivity index. In sensory hearing losses, it will be high, and in normal hearing and neural hearing losses, it will be low.
- sniff t. at fluoroscopy, a t. for diaphragmatic function; paradoxic motion of a hemidiaphragm when a patient sniffs vigorously shows phrenic nerve paralysis or paresis of the hemidiaphragm.
- Snyder t. a colorimetric t. for determining dental caries activity or susceptibility based on the rate of acid production by acidogenic oral microorganisms ( e.g., lactobacillus) in a glucose medium, using bromcresol green as the indicator, and producing a color change from green to yellow. SYN: colorimetric caries susceptibility t..
- solubility t. a screening t. for sickle cell hemoglobin (Hb S), which is reduced by dithionite and is insoluble in concentrated inorganic buffer; addition of blood showing Hb S to buffer and dithionite causes opacity of the solution.
- spironolactone t. administration of spironolactone (400 mg orally) for 4 consecutive days: an increase in serum potassium during the t. and a decrease afterward strongly suggest primary aldosteronism.
- spot t. for infectious mononucleosis a slide t. widely used for the diagnosis of infectious mononucleosis, based on the principle that the heterophil antibodies that occur in the serum of patients with infectious mononucleosis are absorbed by beef red cells but not by guinea pig kidney cells; thus, when horse red cells (which provoke heterophil antibodies) are mixed with patient serum and agglutination occurs in the presence of beef red cells, the presumptive diagnosis is infectious mononucleosis.
- Spurling t. evaluation for cervical nerve root impingement in which the patient extends the neck and rotates and laterally bends the head toward the symptomatic side; an axial compression force is then applied by the examiner through the top of the patient's head; the t. is considered positive when the maneuver elicits the typical radicular arm pain.
- staggered spondaic word t. a t. of central auditory pathway integrity in which spondaic words are presented dichotically.
- standard serologic tests for syphilis, STS for syphilis nontreponemal antigen tests giving presumptive but not conclusive evidence of syphilis, including the Wassermann and VDRL tests.
- standing t. a t. for the effect of a hypotensive drug, carried out by the patient : after taking the drug, the patient stands perfectly still for 1 min commencing from the time that the maximal action of the drug should be manifested; if the dose is adequate, the patient should experience a slight hypotensive reaction.
- standing plasma t. if plasma is stored at 4°C upright in a t. tube, chylomicrons will float to the top and form a creamy layer.
- starch-iodine t. a t. for sweating in which iodine in oil is painted on the skin, followed by dusting with a starch powder which turns blue-black in the presence of iodine and moisture.
- Stein t. in cases of labyrinthine disease the patient is unable to stand or to hop on one foot with eyes shut.
- Stenger t. a t. for detecting simulation of unilateral hearing impairment, in which a tone below the admitted threshold is presented to the t. ear and a tone of lesser intensity is presented to the other ear. If the subject is feigning a hearing loss, the lesser tone cannot be appreciated.
- Stewart t. estimation of the amount of collateral circulation, in case of an aneurysm of the main artery of a limb, by means of a calorimeter.
- Strassburg t. an obsolete t. for bile in the urine; albumin, if present, is precipitated, then cane sugar is added and filter paper is dipped in the fluid and dried; if bile pigments are present in the urine, sulfuric acid will turn the filter paper a reddish violet.
- stress t. any standardized procedure for assessing the effect of stress on cardiac function and myocardial perfusion; stress may be induced by physical exercise or simulated by administration of a coronary vasodilator; heart rate, blood pressure, and electrocardiogram are monitored before, during, and after the challenge; other observations sometimes made are measurement of oxygen consumption, echocardiography, impedance cardiography, appraisal of both myocardial perfusion and cardiac wall motion by radionuclide tracer, and cardiac catheterization.Although neither as sensitive nor as specific as invasive procedures, exercise stress testing has become a standard means of identifying and grading coronary artery disease in people with typical and atypical angina pectoris as well as in those in certain critical occupations (airline pilots, firefighters). It has been found useful for risk stratification in survivors of myocardial infarction (MI), and in planning and monitoring rehabilitation after MI, coronary bypass surgery, or balloon angioplasty. It is also used to assess the safety of exercise programs for people at risk of coronary artery disease because of age or personal or family history. The Masters two-step t., based on repeated ascent and descent of a step-stool, has been superseded by more sophisticated and reproducible methods. Standard exercise testing employs graded physical exertion on an electrically driven treadmill with variable inclination and speed. Alternative methods include a mechanical stair-climbing machine, a stationary bicycle ergometer, and (for those with certain physical disabilities) an arm-exercising (hand-crank) machine. Various protocols and end points are used to measure the outcome of stress testing. Workloads are measured in metabolic equivalents (MET), 1 MET being the amount of oxygen consumed at bedrest (3.5 mL/kg/min). In maximal (symptom-limited) stress testing, the subject continues to exercise at increasing levels of challenge until chest distress, significant hypertension or hypotension, certain arrhythmias, fatigue, gait problems, or severe dyspnea occurs. The Bruce protocol, a standard maximal exercise treadmill protocol, begins with a treadmill speed of 1.7 mph and a grade of 10°, designed to achieve a workload of 4.6 MET, and increases both speed and grade every 3 min. In submaximal (pulse-limited) stress testing, the subject continues exercising until reaching a target heart rate based on age, health history, and physical condition (unless the t. must be stopped earlier because of symptoms). A stress t. session usually lasts 6–10 min. Elevation or depression of ST segments by more than 1 mm during exercise is strongly suggestive of coronary artery disease. Other suggestive changes are T-wave inversion, arrhythmia, a fall in systolic blood pressure, and a marked rise in diastolic blood pressure. Exercise stress-testing protocols achieve 85–90% accuracy in identifying people without coronary artery disease. About 5% of asymptomatic adults have positive stress tests, but only one-third of these have angiographically demonstrable coronary artery disease. False-positive tests occur more frequently in women. Exercise stress testing is contraindicated in acute myocardial infarction, severe congestive heart failure, severe hypertension, hemodynamically significant valvular disease or arrhythmia, active thromboembolic disease, and extreme obesity. As an alternative to exercise, pharmacologic challenge by intravenous infusion of dipyridamole or dobutamine may be performed. In addition to continuous ECG monitoring, the cardiac effects of stress or pharmacologic challenge can be assessed by myocardial scintigraphy after intravenous injection of thallium-201; cineangiography after injection of technetium-99m, with or without multiple-gated acquisition (MUGA) bloodpool imaging; or single-photon emission computed tomography (SPECT).
- string t. 1. an infrequently used t. to locate gastrointestinal hemorrhage; a weighted string is repeatedly swallowed and removed, each time allowing the string to go further down the intestine until blood is encountered; 2. a similar procedure to obtain a specimen from the bowel lumen.
- Strong vocational interest t. a t. that matches an individual's specific likes, dislikes, and interests to those characteristic of persons working in each of a number of vocations.
- Student's t t. a statistical significance t. for assessing the difference between, or the equality of, two or more population means.
- Stypven time t. a t. measuring the clotting time of plasma after addition of Russell's viper venom, useful in evaluating patients with deficiencies in factor X. [Trade name styptic + venom]
- sucrose hemolysis t. isotonic sucrose promotes binding of complement to red blood cells; in paroxysmal nocturnal hemoglobinuria a proportion of the cells is sensitive to complement-mediated lysis, and hemolysis ensues.
- sulcus t. a t. for multidirectional shoulder instability; the seated patient's humerus is pulled caudally, with inferior mobility indicating positive result.
- sulfosalicylic acid turbidity t. a t. for measurement of protein in the urine; sulfosalicylic acid precipitates protein in the urine with a turbidity that is approximately proportional to the concentration of protein in a solution.
- sweat t. a t. for cystic fibrosis of the pancreas in which electrolytes are measured in collected sweat; sodium chloride concentration above 50 mEq/L (children) or 60 mEq/L (adults) is positive.
- sweating t. a t. for locating the level of a lesion in the spinal cord; when the body is heated or the patient is given a diaphoretic, sweat secretion is absent below the level of the lesion.
- t t. a t. that uses a statistic which under the null hypothesis has the t distribution, to t. whether two means differ significantly.
- thematic apperception t. (TAT) a projective psychological t. in which the subject is asked to tell a story about standard ambiguous pictures depicting life situations to reveal his or her own attitudes and feelings.
- thermostable opsonin t. a t. for opsonic activity of antibody in the absence of effect of heat-labile complement.
- Thompson t. 1. t. to detect Achilles tendon disruption; with the patient kneeling on a chair or platform with the feet unsupported, each calf is squeezed; if the Achilles tendon is disrupted, plantarflexion of the foot will not occur. 2. an obsolete t. for gonorrhea in urine; urine is passed into two glasses; if the gonococci and gonorrheal threads are found only in the first glass, the probability is that the process is limited to the anterior urethra. SYN: two-glass t..
- Thormählen t. a t. for melanin; the suspected liquid is treated with sodium nitroprusside, caustic potash, and acetic acid; if melanin is present, the solution takes on a deep blue color.
- Thorn t. a putative t. of adrenal cortical function; stimulation of a normally functioning adrenal cortex by the adrenocorticotrophic hormone is followed by a reduction in the number of circulating eosinophils and lymphocytes and an increase in the excretion of uric acid. The t. lacks sufficient specificity and is rarely used.
- three-glass t. the bladder is emptied by passing urine into a series of 3-ounce t. tubes, and the contents of the first and the last are examined; the first tube contains the washings from the anterior urethra, the second, material from the bladder, and the last, material from the posterior urethra, prostate, and seminal vesicles. SYN: Valentine t..
- thymol turbidity t. precipitation of abnormal proportions of albumin and globulin from the serum of patients with liver disease by addition of thymol. Although popular in the past it has been superseded by quantitative determination of specific proteins and direct measurement of liver enzymes. SYN: Maclagan t., Maclagan thymol turbidity t..
- thyroid-stimulating hormone stimulation t., TSH-stimulating t. a t. that measures the uptake of 131I in the thyroid gland before and after administration of thyroid-stimulating hormone; useful in distinguishing primary hyperthyroidism (increased TSH serum concentration) from secondary or tertiary hyperthyroidism (low TSH serum concentrations).
- thyroid suppression t. a thyroid function t. used to diagnose difficult cases of hyperthyroidism, now largely replaced by the thyrotropin-releasing hormone stimulation t.; triiodothyronine is administered for a week to 10 days, and a reduction of its uptake by the thyroid gland to less than half of the initial uptake is a normal response. SYN: Werner t..
- thyrotropin-releasing hormone stimulation t., TRH-stimulation t. a t. of pituitary response to injection of thyrotropin-releasing hormone, which normally stimulates pituitary secretion of thyroid-stimulating hormone (TSH, thyrotropin), used primarily to distinguish pituitary from hypothalamic causes of thyroid disorders; TSH does not rise in cases of pituitary dysfunction, but does rise in cases of hypothalamic disorders.
- tilt t. any measurement of response during tilting of the body, usually head up but also head down. The t. may be monitored by catheterization, echocardiography, electrophysiologic measurements, electrocardiography, or mechanocardiography.
- tine t. tuberculin t..
- titratable acidity t. the number of milliliters of 0.1 n NaOH required to neutralize a 24-hr specimen of urine.
- tolbutamide t. a t. to detect insulin-producing tumors; after a 1-g intravenous dose of tolbutamide, plasma insulin and glucose are measured at intervals up to 3 hr; higher insulin responses and lower glucose values characterize patients with such tumors.
- tone decay t. the sounding of a continuous tone at threshold for 1 min; if the intensity must be increased by more than 5 dB for continued perception, it is indicative of a neural hearing loss.
- total catecholamine t. a determination of catecholamines in 24-hour urine specimens; elevated values are seen in patients with pheochromocytoma and neuroblastoma.
- TPHA t. SYN: Treponema pallidum hemagglutination t..
- TPI t. SYN: Treponema pallidum immobilization t..
- Trendelenburg t. a t. of the valves of the leg veins; the leg is raised above the level of the heart until the veins are empty and is then rapidly lowered; in varicosity and incompetence of the valves the veins will at once become distended, but placement of a tourniquet around the leg will prevent distention of veins below the incompetent perforators or valves below the tourniquet.
- Treponema pallidum hemagglutination t. a highly sensitive and specific t. for the serologic diagnosis of syphilis; tanned sheep red blood cells are coated with the antigen of Treponema pallidum and, following absorption of nonspecific patient serum antibody, a positive reaction with tanned sheep red blood cells and patient serum indicates the presence of specific antibody for Treponema pallidum in patient serum. SYN: TPHA t..
- Treponema pallidum immobilization t., TPH t. a t. for syphilis in which an antibody other than Wassermann antibody is present in the serum of a syphilitic patient, which in the presence of complement causes the immobilization of actively motile Treponema pallidum obtained from testes of a rabbit infected with syphilis. SYN: TPI t., Treponema pallidum immobilization reaction.
- triiodothyronine uptake t. a t. of thyroid function in which triiodothyronine (T3) is added to a patient's serum in vitro to measure the relative affinities of serum proteins and of an added competitive substance for T3; higher T3 uptakes are associated with hyperthyroidism. SYN: T3 uptake t..
- tuberculin t. application of the skin t. to the diagnosis of infection by Mycobacterium tuberculosis in which tuberculin or its “purified” protein derivative serves as an antigen (allergen); injection of graduated doses of tuberculin or of purified protein derivative into the skin, most often by means of a needle and syringe (Mantoux t.) or by means of tines (tine t.); t. material may also be applied by means of a “patch” in which it is absorbed but this method (patch t.) is viewed as being less reliable; the t. is read on the basis of induration and erythema, the former being considered the more diagnostic of infection with the tubercle bacillus (M. tuberculosis); the t. does not distinguish between infection in a resistant person without disease and an individual with clinical manifestations of disease.
- two-step exercise t. a t. used mainly for coronary insufficiency; significant depression of RST in the electrocardiogram is considered abnormal and suggests coronary insufficiency.
- two-tail t. a statistical t. based on the assumption that the data are distributed in both directions from some central value.
- Tzanck t. the examination of fluid from a bullous lesion for Tzanck cells (altered epithelial cells, rounded and devoid of intercellular attachments). The periphery of these cells is basophilic and the nucleus is spherical and enlarged with prominent nucleoli; they are characteristic of lesions due to varicella, herpes zoster, herpes simplex, and pemphigus vulgaris.
- urease t. 1. a t. for urea based on the conversion of urea into ammonium carbonate by the enzyme urease; 2. a t. for the production of urease, used for identification of cryptococci and Helicobacter pylori.
- urecholine supersensitivity t. urodynamic t. that tries to elicit an abnormal cystometrogram after subcutaneous injection of a drug, urecholine. Urecholine may increase detrusor pressure response during filling in patients with some types of neuropathic bladder.
- urinary concentration t. a t. of renal tubular function whereby the patient is dehydrated for a measured period of time and the specific gravity of the urine is subsequently determined.
- vaginal cornification t. a t. for estrogenic activity, in which the appearance of cornified epithelial cells in a vaginal smear of a t. animal is an indication of the action of an estrogen.
- vaginal mucification t. a t. for progestational activity; stimulation of mucus production by the vaginal epithelium in rats, guinea pig s, or mice by progestogens.
- Valsalva t. the heart is monitored by ECG, pressure recording, or other methods while the patient performs the Valsalva maneuver; the heart becomes smaller in normal persons but may dilate in the patient with impaired myocardial reserve; there is a characteristic complex sequence of cardiocirculatory events, departure from which indicates disease or malfunction.
- van Deen t. SYN: Almén t. for blood.
- van den Bergh t. a t. for bile pigments (bilirubin) by reaction with diazotized sulfanilic acid (diazo reaction).
- van der Velden t. a t. for free hydrochloric acid, the presence of which turns an added solution of methylene blue from violet to green.
- vanillylmandelic acid t. a t. for catecholamine-secreting tumors (pheochromocytoma and neuroblastoma) performed on a 24-hour urine specimen; it is based on the fact that vanillylmandelic acid is the major urinary metabolite of norepinephrine and epinephrine. SYN: 3-methoxy-4-hydroxymandelic acid t., VMA t..
- VDRL t. a flocculation t. for syphilis, using cardiolipin-lecithin-cholesterol antigen as developed by the Venereal Disease Research Laboratory of the United States Public Health Service.
- vitality t. a group of thermal and electrical tests used to aid in assessment of dental pulp health. SYN: pulp t..
- VMA t. SYN: vanillylmandelic acid t..
- Volhard t. a t. for renal function : the patient drinks 1500 ml of water on an empty stomach; if the patient was not dehydrated beforehand and the kidneys are normal, this fluid will be excreted by the end of 4 hours with specific gravity of the urine being from 1.001 to 1.004.
- Wada t. unilateral internal carotid injection of amobarbital to determine the laterality of speech; injection on the dominant side causes transient aphasia or mutism; used prior to surgical treatment of epilepsy.
- Waldenström t. a t. for porphobilinogen or urobilinogen in urine that uses Ehrlich's aldehyde reagent to produce a red color if either of the two substances is present in the urine.
- Wang t. a quantitative t. for indican, which is transformed into indigo-sulfuric acid and then titrated by a solution of potassium permanganate.
- washout t. a means of estimating renal obstruction by the rate of disappearance of excreted radioactive material from the kidney.
- Wassermann t. a complement-fixation t. used in the diagnosis of syphilis; originally the “antigen” was an extract of liver from a syphilitic fetus, but later the active substance, referred to as cardiolipin, was found to be present in normal tissues, including heart, and has been identified as a diphosphatidylglycerol. SYN: Wassermann reaction.
- water-drinking t. a t. of the assessment of open-angle glaucoma, measuring intraocular pressure after drinking a quart of water in 5 min.
- Watson-Schwartz t. a qualitative screening t. for diagnosis of acute intermittent porphyria by the addition of Ehrlich reagent and saturated sodium acetate to the urine; a pink or red color indicates the presence of porphobilinogen or urobilinogen; the former indicates porphyria, the latter does not; therefore, positive results require further differential extraction with butanol and chloroform to eliminate false-positive results due to urobilinogen.
- Weber t. for hearing the application of a vibrating tuning fork to one of several points in the midline of the head or face, to ascertain in which ear the sound is heard by bone conduction, that ear being the affected one if the sound-conducting mechanism of the middle ear is at fault, but the normal one if there is a sensorineural hearing loss in the other ear.
- Weil-Felix t. a t. for the presence and type of rickettsial disease based on the agglutination of X-strains of Proteus vulgaris with suspected rickettsia in a patient's blood serum. SYN: Weil-Felix reaction.
- Wheeler-Johnson t. cystosine or uracil when treated with bromine yields dialuric acid which gives a green color with excess of barium hydroxide.
- whiff t. t. for the fishy odor detectable when KOH is applied to a sample of vaginal discharge in case of bacterial vaginosis.
- Wormley t. a t. for alkaloids, by treating the solution with picric acid or a dilute iodine-potassium-iodide solution, the presence of alkaloids being shown by a color reaction.
- Wurster t. an obsolete t. for tyrosine; the substance is dissolved in boiling water and quinone is added; if tyrosine is present a ruby-colored reaction takes place, the solution changing to brown after a few hours.
- χ2 t. SYN: chi-square t..
- xylose t. a laboratory aid in diagnosing alimentary or essential pentosuria, conditions in which xylose (a pentose) is excreted; the xylose may be identified by rapid reduction of Benedict solution, by nonfermentation by yeasts, or by a positive Bial t. for pentose.
- Yvon t. 1. for alkaloids; to the suspected solution is added a mixture of bismuth subnitrate, potassium iodide, and hydrochloric acid in water; a positive reaction is indicated by the appearance of a red color; 2. for acetanilid in the urine; the suspected fluid is extracted with chloroform and heated with yellow nitrate of mercury; if acetanilid is present, the fluid will be green.
- Zimmermann t. SYN: Zimmermann reaction.
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Tigecycline Evaluation Surveillance Trials; Timolol, Encainide, Sotalol Trial
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test 'test n
1) a critical examination, observation, evaluation, or trial specif the procedure of submitting a statement to such conditions or operations as will lead to its proof or disproof or to its acceptance or rejection <a \test of a statistical hypothesis>
2) a means of testing: as
a ) (1) a procedure or reaction used to identify or characterize a substance or constituent <a \test for starch using iodine> (2) a reagent used in such a test
b) a diagnostic procedure for determining the presence or nature of a condition or disease or for revealing a change in function
c) something (as a series of questions or exercises) for measuring the skill, knowledge, intelligence, capacities, or aptitudes of an individual or group
3) a result or value determined by testing
1) to undergo a test
2) to apply a test as a means of analysis or diagnosis used with for <\test for the presence of starch>
test adj
1) of, relating to, or constituting a test <the \test environment affected the scores>
2) subjected to, used for, or revealed by testing <\test substances>
Medical dictionary. 2011.