1. an examination or trial. 2. a significant chemical reaction. 3. a reagent.
See also under method, phenomenon, reaction, reagent, sign, and symptom.
ABLB test, alternate binaural loudness balance t.
abortus Bang ring test, ABR test, (screening for brucellosis in cattle) since Brucella agglutinins, as well as the organisms, are shed in the milk of infected cattle, a drop of hematoxylin-stained brucellae is mixed in a sample of pooled milk from the herd. After incubation, agglutinated bacteria are adsorbed by the globules of fat that rise to the surface to form a colored ring. Called also milk ring t. and ring t.
acid elution test, (for fetal hemoglobin) air-dried blood smears on a glass slide are fixed in 80 per cent methanol and immersed in a buffer at pH 3.3 (citric acid and sodium phosphate); all hemoglobins are eluted except fetal hemoglobin, which remains fixed in the red cells and can be detected after staining. Called also Kleihauer or Kleihauer-Betke t.
acidified serum test, (for paroxysmal nocturnal hemoglobinuria) the patient's washed red cells are incubated at 370C in acidified normal serum or the patient's acidified serum; after centrifugation the supernatant is examined colorimetrically for hemolysis. In paroxysmal nocturnal hemoglobinuria the red cells are abnormally susceptible to lysis by complement, which is activated by the alternate pathway in acidified serum. Called also Ham t.
acid-lability test, a test to distinguish rhinoviruses from enteroviruses on the basis of their activity at various pH levels, rhinoviruses being inactivated by incubation at pH 3 to 5 for one to three hours.
acid perfusion test, Bernstein t.
acoustic reflex test, measurement of the acoustic reflex threshold by testing for contraction of the stapedial muscle in response to sound; used to differentiate between conductive and sensorineural deafness and to diagnose acoustic neuroma.
Addis test, after the patient is given a dry diet for 24 hours, the specific gravity of the urine is determined.
Adson test, see under maneuver.
agglutination test, (for presence of antibody) cells containing antigens to a given antibody are mixed into the solution being tested; agglutination indicates presence of the antibody. See also agglutination reaction and latex agglutination t.
AL test, a type of patch test in which the materials being tested are applied to cellulose disks arrayed on polyethylene-coated aluminum paper, which is affixed to the skin for several days.
alkali denaturation test, (for fetal hemoglobin) a spectrophotometric method for determining the concentration of hemoglobin F, which depends on the resistance of the hemoglobin molecule to denaturation of its globin moiety when exposed to alkali.
Allen test, (for occlusion of ulnar or radial arteries) the patient makes a tight fist so as to express the blood from the skin of the palm and fingers; the examiner digitally compresses either the radial or the ulnar artery. When the patient unclenches the fist, if blood fails to return to the palm and fingers, there is indicated obstruction to blood flow in the artery that has not been compressed.
Allen-Doisy test, (a formerly common test for estrogens) the material being tested was injected into spayed laboratory mice and a change from leukocytes to cornified cells in their vaginal secretions was a positive result.
alternate binaural loudness balance test, comparison of the intensity levels at which a given pure tone sounds equally loud to the normal ear and the ear with hearing loss; done to determine recruitment with unilateral sensorineural loss. Called also ABLB test.
alternate cover test, a test for determining the type of tropia and/or phoria done by alternately covering each eye and noting the movement of the uncovered eye.
alternate loudness balance test, a hearing test done with pure tones that compares the loudness perceived in one ear with that perceived in the other, with the frequency kept constant.
Ames test, a test for mutagenicity of chemical compounds, using special strains of the bacteria serovar Salmonella enterica subsp. enterica serovar Typhimurium. The bacteria are incubated on a histidine-deficient medium in the presence of the suspected mutagen and rat liver microsomal cell fraction, which contains mixed-function oxidases known to activate many procarcinogens. Growth of bacterial colonies indicates mutagenicity (reverse mutations restoring the ability to synthesize histidine have occurred). About 90–95 per cent of demonstrated mutagens are also carcinogenic.
aminopyrine breath test, a breath test done to measure liver function. The patient is given a dose of 14C-labeled aminopyrine and at 15-minute intervals for two hours the amount of 14C-labeled carbon dioxide in the patient's breath is measured. Excessively low levels of carbon dioxide indicate impaired liver function, such as cirrhosis.
anterior drawer test, see drawer t's.
antibiotic sensitivity test, antibiotic susceptibility test, antimicrobial susceptibility t.
anti-DNA test, anti?double-stranded DNA test, an enzyme immunoassay that uses native double-stranded DNA as an antigen to detect and monitor increased serum levels of anti-DNA antibodies, a sign of systemic lupus erythematosus; used in both detection and management of disease.
antiglobulin test, a test for the presence of nonagglutinating antibodies against red blood cells, using antihuman globulin antibody to agglutinate cells coated with the nonagglutinating antibody. The direct antiglobulin test detects antibodies bound to circulating red cells in vivo. It is used in the evaluation of autoimmune and drug-induced immune hemolytic anemia and erythroblastosis fetalis. The indirect antiglobulin test detects serum antibodies that bind to red cells in an in vitro incubation step. It is used in typing of erythrocyte antigens and in compatibility testing (cross-match). Called also Coombs t.
antiglobulin consumption test, a test for serum antibodies against cellular antigens. Cells are incubated with the serum sample and then with antiglobulin; any serum antibody that binds to the cells will take up antiglobulin. The amount of antiglobulin consumed is determined by testing the supernatant with antibody-coated red cells; the amount of agglutination is inversely proportional to the antiglobulin consumption.
antihuman globulin (AHG) test, direct antiglobulin test; see antiglobulin test.
antimicrobial sensitivity test, antimicrobial susceptibility test, any of numerous tests of how susceptible bacteria are to antimicrobial agents; the bacteria are classified as either sensitive or susceptible, indeterminate or intermediate, or resistant. Called also antibiotic sensitivity or antibiotic susceptibility t.
Apley compression test, (for torn meniscus) with the patient lying prone and the examiner's knee placed on the posterior thigh of the leg being examined, the examiner flexes and externally rotates the tibia while gripping the ankle, then presses the tibia downward. An increase in pain on compression indicates a torn meniscus.
Apt test, (for differentiating fetal from adult hemoglobin) a specimen from an infant's vomitus or stool is mixed with 5 volumes of water and centrifuged so that a clear pink supernatant separates. Sodium hydroxide solution is added to the supernatant; if hemoglobin F (fetal blood) is present, the pink color persists for more than 2 minutes, whereas if hemoglobin A (from swallowed maternal blood) is present, the supernatant turns from pink to yellow within 2 minutes.
aptitude tests, tests given to determine aptitude or ability to undertake study or training in a particular field.
arm ergometry exercise test, a variant of the bicycle ergometer exercise test in which the patient uses the arms to pedal the bicycle.
arylsulfatase test, (for differentiating species of rapid-growing mycobacteria) a sample from a Tween-albumin broth culture of the suspected organism is incubated with tripotassium phenolphthalein disulfate for three days and then alkalinized. Those species producing arylsulfatase (Mycobacterium fortuitum and M. chelonae) show a pink to red positive reaction; a colorless reaction is negative.
aspirin tolerance test, any of various bleeding time tests in which aspirin is administered and its effect on bleeding time is assessed; aspirin prolongs bleeding time in patients with von Willebrand disease and certain other platelet disorders.
association test, a test based on associative reaction. It is usually performed by mentioning words to a subject and noting what other words he or she will give as the ones called to mind. The reaction time is also noted.
atrial pacing stress test, a stress test in which temporary immediately reversible atrial pacing is used to stress coronary reserve; used for patients incapable of exercise or in whom an exercise stress test is contraindicated.
augmented histamine test, (a newer type of histamine test for gastric function) after a 12-hour fast, residual gastric contents are aspirated. Basal gastric secretion is then collected every 15 minutes for 1 hour; at the 30-minute point, antihistamine is given intramuscularly. At the end of the hour, histamine acid phosphate (0.04 mg per kg of body weight) is given subcutaneously, and gastric contents are collected every 15 minutes for another hour. Volume, pH, and titratable acidity are measured on each sample.
autohemolysis test, (for hereditary spherocytosis) a sample of blood is defibrinated and incubated at 370C for 24 and 48 hours; if hereditary spherocytosis is present, spontaneous hemolysis is increased.
automated reagin test, a modification of the rapid plasma reagin test for syphilis, used with automated analyzers in clinical chemistry.
Ayer-Tobey test, Tobey-Ayer t.
Babinski test, see under sign.
Babinski-Weil test, (for labyrinthine disease) the patient, with eyes shut, walks forward and backward ten times; with labyrinthine disease there will be deviation from the straight path, bending to one side when walking forward and to the other when walking backward.
bacteriolytic test, Pfeiffer phenomenon.
Baermann test, (for extraction of soil nematodes from earth and detecting larvae of Strongyloides stercoralis in feces) a specimen of soil or feces is suspended over gauze or wire mesh in a water-filled funnel to which a piece of rubber tubing is attached; larval nematodes migrate from the specimen to the water, and collect in the rubber tubing.
Bang test, abortus Bang ring t.
Bárány test, caloric t.
Bárány pointing test, the patient points at a fixed object alternately with the eyes open and closed; a constant error with the eyes closed indicates a brain lesion.
barium test, gastrointestinal series.
bar-reading test, a test for binocular and stereoscopic vision, which consists of holding a ruler midway between the eyes and the printed page. It is also used as an exercise to develop stereoscopic vision; called also Welland t.
basophil degranulation test, an in vitro procedure testing allergic sensitivity to a specific allergen at the cellular level by measuring staining of basophils after exposure to the allergen; a reduction in the number of granulated cells is a positive result.
Becker test, (for astigmatism) the patient looks at a test card containing lines radiating in sets of three and points out which seem blurred.
Bekhterev (Bechterew) test, the patient seated in bed is directed to stretch out both legs; in sciatica they cannot do this, but can stretch out each leg in turn.
Bender Gestalt test, Bender Visual-Motor Gestalt test, a psychological test used for evaluating perceptual-motor coordination, for assessing personality dynamics, as a test of organic brain impairment, and for measuring neurological maturation. The subject is asked to make free-hand copies of nine simple geometric designs presented separately on cards or sometimes to reproduce the design from memory.
Benedict test, (for glucose in urine) a test for glucose in the urine using Benedict reagent.
bentiromide test, (for pancreatic function)bentiromide is administered orally and its cleavage into benzoyl-tyrosyl and p-aminobenzoic acid is monitored as a measure of pancreatic production of chymotrypsin.
bentonite flocculation test, any agglutination test using antigen adsorbed on particles of bentonite; when the antigen is added to serum containing specific antibodies, flocculation occurs.
benzidine test, (for occult blood in urine or feces)benzidine, acetic acid, and hydrogen peroxide are added to the specimen; hemoglobin catalyzes the oxidation of benzidine by hydrogen peroxide, giving a blue color. This is the most sensitive screening test for occult blood, but it is seldom used because benzidine is a carcinogen, and its use is restricted.
Bernstein test, (for diagnosis of gastroesophageal reflux) 0.1 N hydrochloric acid infused at a rate of 120 drops per minute produces pain and other symptoms. Called also acid perfusion t. and esophageal acid perfusion t.
Bial test, (for pentoses in urine) the specimen is heated with a solution of orcinol, hydrochloric acid, and ferric chloride; pentoses are converted to furfural, which reacts with orcinol to form a green product.
bicycle ergometer exercise test, an exercise test in which the patient pedals a stationary bicycle ergometer; the test is usually graded, with incremental or continuous increases in power produced by increases in pedal resistance at a given pedal speed. Cf. treadmill exercise t.
Bielschowsky head-tilting test, (for types of paresis) tilting the head to the right and the left shoulder with the patient looking at a distance fixation device permits distinction between superior rectus paresis and contralateral superior oblique paresis.
bile acid breath test, a breath test for overgrowth of bacteria in the intestine: the patient is given a dose of a conjugated bile acid labeled with carbon 14 and the amount of radioactively labeled carbon dioxide in the breath is measured at hourly intervals. Excessive labeled carbon dioxide in the breath indicates excessive bacteria in the intestine breaking down the bile acids.
bile solubility test, (for differentiation of pneumococci from other streptococci) a sample of a broth culture is incubated at pH 7.4 to 7.6 with sodium deoxycholate. A decrease in turbidity (positive test) indicates lysing of the cells. Pneumococci give a positive result, whereas other viridans streptococci give a negative one.
biliary drainage test, examination of the contents of the duodenum at the site where the common bile duct empties into it; this is done when other, more conventional diagnostic tests for gallbladder disease reveal no pathology but the patient's symptoms persist. Specimens are collected with a special tube and examined for leukocytes, cholesterol crystals, and parasites.
bilirubin test, see specific tests, including Fouchet t. and Harrison spot t.
binaural distorted speech tests, tests of the capacity of the central nervous system to coordinate two incoming speech patterns, each of which is incomplete.
Binet test, Binet-Simon test, a method of testing the mental capacity of children and youth by asking a series of questions adapted to, and standardized on, the capacity of normal children at various ages. According to the answers given, the mental age of the subject is ascertained.
Bing test, (for hearing) a vibrating tuning fork is held to the mastoid process and the auditory meatus is alternately occluded and left open: changes in loudness (positive Bing) are perceived by the normal ear and in sensorineural hearing loss, but in conduction hearing loss no difference is perceived (negative Bing).
biuret test, a colorimetric test for protein that makes use of the biuret reaction (q.v.).
bleeding time test, a test of bleeding time, assessing capillary function and platelet function, such as Duke t., Ivy t., or the template method.
Bodal test, test of color perception by the use of colored blocks.
bone conduction tests, tests of bone conduction; see tuning fork t's.
Bozicevich test, a serologic test for the detection of trichinosis.
breath test, any of various tests in which a person's breath is analyzed for presence of something abnormal. Subgroups called the 13C breath tests and 14C breath tests involve administration of organic compounds labeled with carbon 13 (heavy carbon) or carbon 14 (radioactive carbon) and measuring the subsequent levels of labeled carbon dioxide in the patient's breath; the labeled compound may be found to be metabolized normally, too fast, or too slow in the gastrointestinal tract.
breath hydrogen test, hydrogen breath t.
Broadbent test, (for cerebral dominance of language function) different numbers (or words) are presented simultaneously to the two ears; right-handed persons tend to report first the words going into the right ear.
bronchial challenge test, see under challenge.
buccal smear test, sex chromatin t.
Burchard-Liebermann test, Liebermann-Burchard t.
χ2 test, chi-square t.
caffeine breath test, a breath test for liver function: the patient is given a dose of caffeine labeled with carbon 13; excessively low levels of labeled carbon dioxide in the patient's breath indicate inadequate metabolism of it by the liver, as in patients who have cirrhosis or who smoke.
calcium infusion test, (for hyperglycinemia)calcium gluconate is administered to the fasting patient for 180 minutes. Serum samples are obtained 30 minutes before infusion, at its initiation, and every 30 minutes for two hours afterwards. The patient with a gastrinoma will show a sharp rise in production of gastrin.
California mastitis test, (for subclinical mastitis in cows) equal amounts of milk, bromcresol purple, and an anionic surface-active substance are mixed in four separate cups within a plastic paddle by rapidly rotating the paddle horizontally; a positive reaction is indicated by various degrees of gel formation, according to the degree of abnormality of the milk.
caloric test, (for ocular and vestibular functioning) irrigation of the normal ear with warm water produces rotatory nystagmus (caloric nystagmus) toward the irrigated side; irrigation with cold water produces similar nystagmus away from that side. Called also Bárány t., sign, or symptom and nystagmus t.
CAMP test, (for the presumptive identification of Group B beta-hemolytic streptococci) a culture of streptococcus is streaked on a blood agar plate near a streak of beta-lysin–producing Staphylococcus aureus. Group B streptococci produce a substance (CAMP factor) that enlarges the zone of lysis formed by the staphylococcal beta-hemolysin.
capillary fragility test, capillary resistance test, tourniquet t. (def. 1).
captopril test, (for renovascular hypertension) the angiotensin-converting enzyme inhibitorcaptopril is administered to a patient with hypertension. If the patient's plasma renin level increases sharply within one hour, this indicates that the hypertension has a renovascular cause such as renal artery stenosis (see under stenosis).
carbohydrate utilization test, any of several tests for identification of yeasts and certain other organisms according to a profile of carbohydrate assimilation.
carbon monoxide test, see specific tests, including Preyer t., Rubner t. (def. 1), Salkowski t. (def. 1), Wetzel t., Zaleski t.
card test, a type of laboratory test that uses nonmicroscopic techniques; tissue or fluid to be examined is placed on a plastic-coated card with a reagent and visible reactions such as color changes or agglutination are noted.
Casoni intradermal test, (for hydatid disease) after injection into the skin of hydatid fluid, if there is immediate or delayed production of a wheal and flare reaction, this denotes hydatid infection. The test is now little used because of low specificity.
catalase test, (for the production of heat-stable catalase by bacteria) a culture is treated with hydrogen peroxide and heated. The presence of gas bubbles indicates a positive reaction. Micrococci, staphylococci, most species of Bacillus, and anaerobic diphtheroids are catalase-positive; streptococci, pneumococci, and most Actinomyces are catalase-negative. Catalase quantity and heat stability are species-dependent; inclusion of the detergent Tween-80 makes the test semiquantitative.
catoptric test, (for cataract) observations are done of the reflections from the cornea and the surfaces of the crystalline lens.
CCK test, cholecystokinin t.
cellobiose/mannitol test, (for celiac disease)cellobiose and mannitol are administered and their relative degrees of absorption are compared. Because of the relative permeability of the intestine to large molecules like cellobiose and small ones like mannitol, in celiac disease there is greater absorption of cellobiose and less absorption of mannitol.
challenge test, challenge (def. 3).
chemiluminescence test, a sensitive test of neutrophil microbicidal function that involves detection of the chemiluminescent energy emitted by unstable and highly reactive oxygen metabolites, e.g., singlet oxygen, produced during the respiratory burst following phagocytosis. It is able to detect heterozygous carriers of chronic granulomatous disease as well as homozygotes and also patients with myeloperoxidase deficiency.
Chick-Martin test, a method for determining the phenol coefficient of disinfectants in water contaminated by organic matter; serial dilutions of disinfectant are incubated with a specified quantity of yeast and bacteria for a period of 30 minutes to see how many of the microorganisms have been killed.
Chimani-Moos test, a test for detecting simulated deafness.
chi-square test, any statistical hypothesis test that employs the chi-square (χ2) distribution (q.v.), especially two tests applied to categorical data: the χ2-test of goodness of fit, which tests whether an observed frequency distribution fits a specified theoretical model, and the χ2-test of independence or homogeneity, which tests whether two or more series of frequencies (the rows and columns of a contingency table) are independent. In both cases the test statistic is the sum over all categories of the squared difference between the observed and expected frequencies divided by the expected frequency, under the null hypothesis. The sampling distribution of this χ2-statistic approaches the χ2-distribution as the sample size increases, under the null hypothesis.
cholecystokinin test, (for pancreatic function)CCK test; after intravenous administration of cholecystokinin, the resultant pancreatic secretion of amylase, trypsin, and lipase is measured by collection through a tube in the duodenum. This test is often combined with the secretin test and called the secretin-cholecystokinin test.
cholesterol test, see specifc tests, including Liebermann-Burchard t., Salkowski t. (def. 2), Schultze t. (def. 2).
cis-trans test, in microbial genetics, a test to determine whether two (recessive) mutations are alleles (located in the same gene) or pseudoalleles (located in different genes). A heterozygote carrying the mutations on the same chromosome (cis configuration) will show a wild-type phenotype in either case, but one carrying the mutations on different chromosomes (trans configuration) will show a wild-type phenotype if they are pseudoalleles and a mutant phenotype if they are alleles.
citrate test, (for differentiation of organisms of the Enterobacter group of bacteria) the test organism is grown on a medium containing citrate as its sole carbon source (Simmons citrate agar). The metabolism of citrate (positive reaction) turns the medium from green to blue. The Enterobacteriaceae are mostly positive; Edwardsiella, Escherichia, Morganella, Shigella, and Yersinia are negative.
clomiphene citrate challenge test, (for female factor infertility) the patient's blood levels of follicle-stimulating hormone are measured on the third day of her menstrual cycle and she takes clomiphene citrate on days 5 through 9. If her levels of follicle-stimulating hormone are elevated on day 10, she probably has a diminished ovarian reserve.
coagulase test, (for coagulase activity) bacteria are added to citrated or oxalated (human or rabbit) blood plasma; in the presence of coagulase, the plasma gels within three hours. Coagulase activity is also demonstrable by mixing bacteria with blood plasma on a slide; if positive, clumping occurs, with fibrin formation.
cocaine test, after instillation of a cocaine solution in each eye, the pupil of an eye affected by Horner syndrome remains smaller than that of the normal eye.
coccidioidin test, an intracutaneous test for coccidioidomycosis, using the antigen coccidioidin. Because most individuals in endemic areas are skin test positive it is not useful in diagnosis. A negative skin test (cutaneous anergy) occurs in many patients with disseminated disease and indicates a poor prognosis.
Cohn test, a test for color perception by the use of variously colored embroidery patterns.
colchicine test, see Zeisel t.
cold pressor test, immersion of one hand in ice water for several minutes, causing vasoconstriction, tachycardia, and transient hypertension; it is used as an alternative stress test for detection of coronary artery disease in patients incapable of undergoing an exercise stress test and as a test of vasomotor function.
collateral circulation test, see specific tests, including Korotkoff t., Pachon t., and tourniquet t. (defs. 2, 3).
color perception test, see specific tests, including Bodal t., Cohn t., Ishihara t., lantern t., Nagel t.
combined anterior pituitary test, a dynamic test of the functioning of the anterior pituitary, such as after surgery or radiation to the gland; four exogenous hypothalamic hormones are administered intravenously (corticotropin-releasing hormone, growth hormone–releasing hormone, luteinizing hormone–releasing hormone, and thyrotropin-releasing hormone) and levels of the corresponding pituitary hormones in the blood are assessed at intervals for about two hours.
complement fixation test, see under fixation.
concentration test, (for renal function) the patient is placed under conditions that cause the normal person to elaborate urine containing one or more constituents in high concentration, and the results are observed to see whether the patient is able to attain this concentration.(for renal tubular function) water restriction to measure urine concentration as reflected in specific gravity or osmolality.
conglutinating complement absorption test, a test resembling the complement fixation test (see under fixation), using as the indicator of antigen-antibody reaction the disappearance of conglutinin (q.v.) activity.
Congo red test, (for amyloidosis) Congo red is injected intravenously; if more than 60 per cent of the dye disappears after 1 hour, amyloidosis is indicated.
conservative test, a test having a type I error probability that is at most a stated nominal level.
contact tests, patch t's.
contraction stress test, the monitoring of the response of the fetal heart rate to uterine contractions by cardiotocography; uterine contractions may be spontaneous or induced by maternal nipple stimulation or by intravenous infusion of oxytocin (oxytocin challenge test). A negative (normal) test consists of three contractions within a 10-minute period with no deceleration of the fetal heart rate; a late deceleration pattern may reflect fetal hypoxia.
Coombs test, antiglobulin t.
copper test, see Schönbein t. (def. 2).
cover test, see alternate cover t. and cover-uncover t.
cover-uncover test, a test for determining the type of phoria, by covering one eye and noting its movement as it is uncovered.
Crafts test, in organic disease of the pyramidal tract, stroking with a blunt point upward over the dorsal surface of the ankle, the leg being extended and the muscles relaxed, produces a dorsal extension of the great toe similar to the Babinski reflex.
Crampton test, a test for physical resistance and condition based on the difference between the pulse and blood pressure in the recumbent position and in the standing position. A difference of 75 or more indicates good condition; one of 65 or less shows a poor condition.
creatinine test, see specific tests, including Jaffé t. (def. 1), Kerner t., Salkowski t. (def. 4), Thudichum t., von Maschke t., Weyl t. (def. 1). See also creatinine, methods for, under method.
Cuignet test, (for simulated unilateral blindness) the bar-reading test used to detect simulated unilateral blindness or malingering.
cycle ergometer test, bicycle ergometer exercise t.
cysteine test, see specific tests, including nitroprusside t. (def. 1) and Sullivan t.
cystine test, see Liebig t.
cytosine test, see Wheeler and Johnson t.
dark-adaptation test, (for vitamin A deficiency) a test based on the fact that with a deficient intake of vitamin A the ability to see a dimly illuminated object in a dark room is diminished.
darkroom test, (to determine the tendency to develop acute angle-closure glaucoma) ocular pressure is measured by the applanation tonometer, the subject is placed in a darkroom for one hour, and applanation tonometry is then repeated.
Davidsohn differential absorption test, Paul-Bunnell-Davidsohn t.
D-dimer test, see under assay.
dehydrocholate test, (for the speed of blood circulation) sodium dehydrocholate solution is injected intravenously; the usual time elapsing until a bitter taste in the mouth occurs is between 10 and 14 seconds.
Denver Developmental Screening test, a test for identification of infants and preschool children with developmental delay.
deoxyribonuclease test, (for the presence of deoxyribonuclease in bacteria) a nutrient agar plate containing deoxyribonucleic acid and toluidine blue is inoculated from a young agar slant; after incubation a red zone around the inoculum indicates the presence of deoxyribonuclease. Called also DNase t.
deoxyuridine suppression test, (for folate or cobalamin deficiency) lack of 5,10-methylene tetrahydrofolate inhibits incorporation of deoxyuridine into DNA, so that deoxyuridine fails to inhibit incorporation of 3H-thymidine.
dexamethasone suppression test, high-dose, (for Cushing syndrome) urinary levels of cortisol and 17-hydroxycorticosteroid are measured following administration of dexamethasone at 16 times the level used in replacement therapy; cortisol secretion is suppressed in patients with Cushing syndrome but not in those with ectopic ACTH syndrome or adrenal tumors.
dexamethasone suppression test, low-dose, (for Cushing syndrome) urinary levels of cortisol and 17-hydroxycorticosteroid are measured following administration of dexamethasone at three to four times the level used in replacement therapy; cortisol secretion is suppressed in normal patients but not in those with Cushing syndrome.
dextrose test, glucose t.
DFA-TP test, direct fluorescent antibody–Treponema pallidum t.
diabetes test, any of various tests for diabetes mellitus; see glucose t. and glucose tolerance t.
diacetyl test, (for urea) the solution to be tested is mixed with concentrated hydrochloric acid and diacetyl monoxime, a more stable precursor of diacetyl; condensation of diacetyl and urea forms the yellow chromogen diazine, particularly at an elevated temperature (usually 45 0C).
Dick test, (for susceptibility to scarlet fever) purified erythrogenic toxin from group A streptococci is injected intradermally; appearance within 24 to 48 hours of a small area of reddening of the skin indicates susceptibility of the subject.
differential test for infectious mononucleosis, Paul-Bunnell-Davidsohn t.
dilution test, see under method.
dimethylglyoxime test, (for nickel) the object or substance being tested is placed in a solution of dimethylglyoxime; if nickel is present, the solution will turn brown.
diphtheria test, see Schick t.
direct antiglobulin test, direct Coombs test, see antiglobulin t.
direct fluorescent antibody–Treponema pallidum test, DFA-TP test; a serologic test for syphilis that uses direct immunofluorescence.
disk diffusion test, a type of antimicrobial susceptibility test in which agar plates are inoculated with a standardized suspension of a microorganism and then antibiotic-containing disks are applied to the agar surface. Following overnight incubation, the diameters of the zones of inhibition or clearing surrounding the disks are measured to calculate how susceptible or resistant the microorganism is.
DNase test, deoxyribonuclease t.
Dolman test, (for ocular dominance) the patient holds in both hands a card with a hole in it through which to look at a light.
Donath-Landsteiner test, (for paroxysmal cold hemoglobinuria) a test based on the fact that the blood of patients with this disease contains complement-dependent iso- and autohemolysin (Donath-Landsteiner antibody) which unites with red cells only at low temperatures (20 to 100C), hemolysis occurring only after warming to 370C.
double glucagon test, (for deficiency of amylo-1-6-glucosidase) glucagon is administered after a 12-hour fast and again shortly after a meal; if the blood sugar fails to rise after the first administration but has a normal rise after the second, the test is positive.
Draw-a-Person test, a commonly used projective test for assessing personality style and psychopathology by interpretation of a drawing of a person done by the subject, based on the assumption that their personality characteristics will be introjected onto the drawing.
drawer tests, (for integrity of cruciate ligaments of knee) the knee is flexed to a 900 angle; at the femoral-tibial junction, if the tibia can be drawn too far forward there is rupture of the anterior ligaments (anterior drawer t.) and if it can be drawn too far back there is rupture of the posterior ligaments (posterior drawer t.). Called also drawer signs.
drinking test, (for glaucoma) one liter of water is ingested as rapidly as possible into an empty stomach. The intraocular pressure is measured every 15 minutes; a rise of 8 to 15 mm Hg in less than 30 minutes indicates glaucoma. Called also water provocative t.
Duane test, one using a candle flame and prisms to measure the degree of ocular heterophoria.
Dugas test, (for diagnosis of dislocation of the shoulder) place the hand of the affected side on the opposite shoulder and bring the elbow to the side of the chest; if this cannot be accomplished (Dugas sign), dislocation of the shoulder exists.
Duke test, a type of bleeding time test in which the incision is made in the earlobe.
dye exclusion test, the determination of cell viability in vitro. Following exposure of a cell preparation to trypan blue or eosin, dead cells take up the dye from the medium whereas living cells remain unstained.
dynamic test, one designed to test some physiologic process in the body, such as a challenge, a stimulation test, or a suppression test.
E test, a variation of the dilution method for testing antimicrobial susceptibility. A plastic strip is used that has a defined concentration of drug on one side and an interpretive scale of minimal inhibitory concentrations on the other side; it is put on the surface of an agar medium inoculated with the microorganism to be tested. This method is most useful for fastidious bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, and certain anaerobic bacteria.
early pregnancy test, a do-it-yourself immunologic test for pregnancy performed in the home as early as one day after menstruation was expected (missed period); a variety of tests exist, all based on an increase in urinary levels of human chorionic gonadotropin after fertilization.
ECG stress tests, stress t's.
Ehrlich test, Ehrlich diazo reaction; see under reaction.
Elek test, toxigenicity t.
Elsberg test, (for sense of smell) variations in function of the sense of smell, or in rate of fatigue, may be used to distinguish between intracerebral and extracerebral tumors or other lesions.
Ely test, (for contracture) with the patient prone, if flexion of the leg on the thigh causes the buttocks to arch away from the table and the leg to abduct at the hip joint, there is contracture of the lateral fascia of the thigh.
EP test, erythrocyte protoporphyrin t.
Erhard test, a test for detecting simulated deafness.
Erichsen test, see under sign.
erythrocyte protoporphyrin test, (for lead poisoning)EP test; a screening test in which erythrocyte protoporphyrin levels are determined by direct fluorometry of whole blood or fluorescence analysis of whole blood extracts; levels are increased in lead poisoning and iron deficiency.
esophageal acid perfusion test, Bernstein t.
euglobulin lysis test, (for hemorrhagic tendencies) the time of fibrinolysis is measured by determining the time required to dissolve an incubated clot composed of precipitated plasma euglobulin and exogenous thrombin. Lysis in less than 90 minutes indicates abnormally enhanced fibrinolytic activity.
exact test, a statistical test based on the actual probability distribution of the data in the study, rather than on an approximation of it.
exercise tests, exercise stress tests, any of various stress tests in which exercise is used in the electrocardiographic assessment of cardiovascular health and function, particularly in the diagnosis of myocardial ischemia. The most widely used forms are the treadmill and bicycle ergometer exercise tests; they are usually graded, consisting of a series of incrementally increasing work loads sustained for defined intervals.
F-test, a statistical test comparing the means of more than two groups simultaneously by comparing two different measures of variance of the observations. One statistic measures the variations between the means of the groups (the between-groups variation), the other the variations within the groups (the within-group variation). If the two measures of variance yield similar results and their ratio, the F-ratio, approximates 1.0, the null hypothesis that all observations came from the same population cannot be rejected, whereas under the alternative hypothesis, the F-ratio is expected to be larger than 1.0. The test is the first step in the analysis of variance (ANOVA).
FAB test, fluorescent antibody t.
Farber test, presence of swallowed vernix cells in the meconium of a newborn baby indicates partial intestinal stenosis; their absence indicates intestinal atresia.
Farr test, (a radioimmunoassay for measuring absolute amounts of antibody) antibody is reacted with radiolabeled antigen and precipitated with ammonium sulfate; bound antigen or hapten is precipitated while free antigen remains in solution. This test is based on the capacity of antibody to combine with antigen rather than on such secondary properties as precipitation and therefore measures all immunoglobulin classes and subclasses.
FeNa test, excreted fraction of filtered sodium test, a measure of renal tubular reabsorption of sodium, calculated as follows:
where U and P represent concentrations of sodium and creatinine in urine and plasma, respectively.
femoral nerve stretch test, (for lesions of third or fourth lumbar disk) passive knee flexion in the prone position causes pain in the back or thighs.
fermentation test, (for glucose and other sugars in urine) boil a specimen to destroy bacteria, then add baker's yeast and incubate; perform Benedict test for reducing sugars on this specimen and an unfermented specimen. Glucose, fructose, and maltose are fermented and give a reaction in the unfermented specimen but not in the fermented specimen.
fern test, see ferning.
ferric chloride test, ferric chloride in acidic solution is added to a urine specimen; many substances are oxidized giving colored products. Positive reactions are given by melanin, acetoacetic acid, bilirubin, phenothiazines, salicylates, and the keto acids present in phenylketonuria, alkaptonuria, maple syrup urine disease, and oasthouse urine disease.
fetal acoustic stimulation test, (for assessing fetal health) a vibroacoustic stimulus such as an electronic artificial larynx is applied either externally or directly to the fetus and resultant fetal movements, cardioacceleration, and alterations in respiration are evaluated.
FIGLU excretion test, histidine loading t.
finger-to-finger test, similar to finger-nose test, for testing coordinated movements of the extremities.
finger-nose test, finger-to-nose test, (for coordinated movements of the upper limbs) with arm extended to one side the patient is asked to slowly try to touch an index finger to the end of the nose.
Finn chamber test, a type of patch test in which the materials being tested are held in shallow aluminum cups (Finn chambers) that are taped against the skin, usually for several days.
Fishberg concentration test, (a test of kidney function) the patient's evening meal includes not more than 200 mL of fluid, and nothing else is consumed before morning. Urine voided during the night is discarded. The morning urine is saved, the patient kept in bed, and the urine of 1 hour later and 2 hours later is saved. If the specific gravity of any of these 3 specimens is less than 1.024 there is impairment of renal concentration.
Fisher exact test, a statistical hypothesis test of independence of rows and columns in a 2 × 2 contingency table based on the exact sampling distribution of the observed frequencies, useful when any expected value in the table is small.
fistula test, the air in the external auditory canal is compressed or rarefied: if there is erosion of the inner osseous wall of the tympanum exposing the membranous labyrinth, nystagmus will be produced, provided the labyrinth still functions.
Flack test, (of physical efficiency) after a full inhalation the subject blows as long as possible into a mercury manometer with a force of 40 mm mercury.
flocculation test, any serologic test in which a flocculent agglomerate is formed; usually referring to a variant form of the precipitin reaction, and sometimes to types of agglutination tests.
fluorescein dilaurate test, pancreolauryl t.
fluorescent antibody test, FAB test; a test for the distribution of cells expressing a specific protein by binding antibody specific for the protein and detecting complexes by fluorescent labeling of the antibody; if it is combined with cell sorting, determinations can be quantitative.
fluorescent treponemal antibody absorption test, FTA-ABS test; the standard treponemal antigen serologic test for syphilis; patient serum is diluted with an extract of other treponemes to remove nonspecific antibodies, then reacted with a strain of Treponema pallidum fixed to a glass slide; specific antibodies adhering to the treponemes are demonstrated with fluorescein-labeled antihuman globulin. Positive tests are seen in about 85 per cent of cases of primary syphilis, 100 per cent of secondary syphilis, and 98 per cent of late syphilis.
food challenge test, food challenge.
formaldehyde test, see specific tests, including Jorissen t. and Kentmann t.
Fouchet test, (for bilirubin in urine) a few drops of Fouchet reagent are added to the specimen; a green color is produced if bilirubin is present.
Fournier test, (for ataxic gait) the patient is asked to rise on command from a sitting position, then to rise and walk, to stop quickly on command, and then to walk and turn around quickly on command. The ataxic gait is thus brought out.
Francis test, (for bile acids in urine) in a test tube is placed 2 g of glucose in 15 g of sulfuric acid and the urine is placed on top of this; a purple color forms if bile acids are present.an intracutaneous test in pneumonia for ascertaining the body response to the infection and whether the specific antibodies are present after treatment with antipneumococcus serum. The homologous pneumococcus polysaccharide is used in the skin test.
Fränkel test, examination of the nasal cavity with the patient's head bent down between the knees and rotated so that the side to be examined is turned upward. If pus is seen in the middle meatus, suppuration in some of the anterior accessory sinuses is indicated.
Friberg test, tray agglutination t.
Friderichsen test, (for vitamin A deficiency) determination of the weakest light stimulus which will give rise to an oculomotor reflex. A variation from normal indicates vitamin A deficiency.
fructosamine test, determination of the serum fructosamine level by measurement of the reduction of nitroblue tetrazolium to purple under alkaline conditions; it is used as an index of the average glycemic state over the preceding two to three weeks.
fructose test, see Rubner t. (def. 2) and Selivanoff t.
fructose tolerance test, (for liver function) a large quantity of fructose is administered and the power of the liver to absorb it is monitored.
FTA-ABS test, fluorescent treponemal antibody absorption t.
fundus reflex test, retinoscopy.
Funkenstein test, an index of central autonomic reactivity, consisting of observing the response in systolic blood pressure after intramuscular injection of 10 mg of acetylcholine.
Gaenslen test, see under sign.
galactose breath test, a breath test of liver function: the fasting subject is administered a dose of galactose labeled with carbon 13 and levels of labeled carbon dioxide in the breath are measured at specific time intervals. Low levels of carbon dioxide indicate that the galactose is not being metabolized properly, indicating either an enzyme deficiency or liver dysfunction such as the fibrosis accompanying hepatitis.
galactose tolerance test, a laboratory test done to determine the liver's ability to convert galactose into glycogen. Two methods may be used; the oral method, which requires about 5 hours to complete, and the intravenous method, which requires about 2 hours and is more accurate. With the oral method, elimination of more than 3 g of galactose in the urine during a 5-hour period indicates liver damage. With the intravenous method, all galactose should have been eliminated from the blood 45 minutes after its injection.
gastric function test, see specific tests, such as augmented histamine t. and pentagastrin t. Abnormal results on the Schilling test may indicate defective gastric secretion of intrinsic factor.
Gault test, (for simulated deafness) the patient's good ear is closed and a sound is made near the supposed bad ear; winking on the tested side indicates hearing.
gaze test, (for ocular and vestibular functioning) movements of the eye are recorded with the patient gazing straight at an object and at positions off to different sides of it; then with eyes closed for 20 seconds, the patient must perform a small mental exercise. The eyes normally should assume a center gaze while they are closed.
gelatin agglutination test, a sperm agglutination test in which the sperm and serum are put in a gelatin solution. Called also Kibrick t.
gel diffusion test, see immunodiffusion.
Gerhardt test, (for acetoacetic acid in the urine) filter, in order to remove the phosphates, and add a few drops of a solution of ferric chloride, which produces a deep red color, which disappears when sulfuric acid is added.(for bile pigments in the urine) shake urine with an equal measure of chloroform and then add iodine tincture and potassium hydroxide to the separated chloroform; a yellow or yellowish brown color is produced (Charles Frédéric Gerhardt).
germ tube test, (for Candida albicans) an inoculum of Candida is incubated in serum for 2 to 3 hours at 370C; formation of germ tubes is a positive result.
Gibbon and Landis test, (for peripheral circulation) a pair of extremities (the hands, if the feet are to be tested; the feet, if the hands are to be tested) are immersed in a bath of 430–450C. If the temperature in the unimmersed extremities rises, the circulation is normal.
Gies biuret test, (for proteins) a form of biuret test employing the following reagent: mix 25 mL of a 3 per cent solution of cupric sulfate and 975 mL of a 10 per cent solution of potassium hydroxide.
glucagon stimulation test, (for deficiency of growth hormone) blood samples are taken before and at intervals of 1, 2, 2.5, and 3 hours after subcutaneous or intramuscular injection of glucagon; radioimmunoassay of the serum is then done by enzyme partition.
glucose test, any of various laboratory tests for glucose in the urine; many formerly common ones are no longer used. See Benedict t., Rubner t., and saccharimeter t.
glucose tolerance test, a metabolic test of carbohydrate tolerance, measuring active insulin, a hepatic function based on the power of the normal liver to absorb and store large quantities of glucose, and the effectiveness of intestinal absorption of glucose. The most common method is the oral glucose tolerance test (q.v.).
glucose tolerance test, oral, the most common kind of glucose tolerance test. Glucose is ingested into a fasting stomach and measurements of plasma glucose are taken over time; if glucose levels do not return to normal within 2 to 2.5 hours the patient may have impaired glucose tolerance or diabetes mellitus.
glycosylated hemoglobin test, measurement of the percentage of hemoglobin A molecules that have formed a stable keto–amine linkage between the terminal amino acid position of the β-chains and a glucose group; in normal persons this amounts to about 7 per cent of the total, in diabetics about 14.5 per cent. Used in the management of patients with diabetes mellitus.
Gmelin test, (for bile pigments) fuming nitric acid is so added to the suspected urine that it forms a layer under it. Near the junction of the two liquids, rings are formed—a green ring above, and under it a blue, violet-red, and reddish yellow. If the green and violet-red rings are absent, the reaction shows the probable presence of lutein.
Goodenough draw-a-man test, Goodenough draw-a-person test, (for intelligence) the general intelligence of the child is assessed by asking him or her to draw a picture of a man as well as possible.
Goodenough-Harris drawing test, a revision of the Goodenough draw-a-man test, in which scoring emphasizes the presence or absence of body and clothing detail rather than artistic skill.
graded exercise tests, see exercise t's.
Graefe test, (for heterophoria) on holding a prism of 10 degrees before one eye, base up or down, two images are formed; one of these images is displaced laterally in heterophoria.
Graham test, the intravenous or oral administration of iodophthalein sodium prior to radiographic examination of the gallbladder.
Griess test, a formerly common test for nitrate-reducing bacteria in a fluid, done by adding sulfuric acid and an indicator to a dilute solution and watching for a color change. The same name is now applied to nitrite tests for bacteriuria in which a urine specimen collected when the patient wakes in the morning is tested for nitrites using a special tape or dipstick.
Grigg test, (for proteins) metaphosphoric acid precipitates all proteins except the peptones.
group test, a test of intelligence or aptitude given to a number of persons at one time.
guaiac test, (for occult blood) glacial acetic acid and a solution of gum guaiac are mixed with the specimen; on addition of hydrogen peroxide, the presence of blood is indicated by a blue tint.
Guerreiro-Machado test, Machado-Guerreiro t.
Guthrie test, (for phenylketonuria) blood from an infant suspected of having abnormally high levels of phenylalanine is placed on filter paper, which is then put on an agar plate with a strain of Bacillus subtilis that requires phenylalanine for growth. In the presence of blood containing phenylalanine, a halo will form around the filter paper.
Gutzeit test, (for arsenic) a paper is moistened with an acidulated silver nitrate solution and exposed to the fumes from the suspected liquid, which is mixed with zinc and dilute sulfuric acid. The formation of a yellow spot on the paper indicates the presence of inorganic arsenic compounds.
Haagensen test, observation of the contour of the breasts when the patient leans forward as a means of detecting malignant changes.
HAI test, hemagglutination inhibition t.
Hallion test, Tuffier t.
Ham test, acidified serum t.
Hamilton test, when the shoulder joint is luxated, a rule or straight rod applied to the humerus can be made to touch the outer condyle and the acromion at the same time.
hapten inhibition test, serologic characterization of an antigenic determinant by employing known haptens to mask the antigen binding site of antibody specific for it.
harmonic acceleration test, (for vestibuloocular reflex) rotation of a patient seated in a chair in complete darkness, with monitoring of eye movements; with normal vestibuloocular reflexes the eyes will undergo rotatory nystagmus to the same degree in both eyes in the direction opposite to that of the rotation.
Harrison spot test, (for bilirubin in urine) add to 10 mL of urine 5 mL of a 10 per cent solution of barium chloride, mix, and filter. Spread filter paper on dry filter paper. Add one to two drops of Fouchet reagent (trichloroacetic acid 25 g, water 100 mL, and 10 per cent solution of ferric chloride 10 mL); a positive reaction gives a blue to green color.
hatching test, (for schistosomiasis) live schistosome eggs in urine or feces can be detected when they hatch to produce miracidia when placed in water; the miracidia are attracted to light and can readily be identified.
Heaf test, a type of intracutaneous tuberculin test; needle points of a multiple-puncture apparatus are dipped into 1 to 2 drops of tuberculin PPD, then placed on the forearm and made to penetrate the skin to a depth of 1 mm, depositing tuberculin in the outer layer of the skin. In three to seven days, a positive reaction is palpable, coalescing induration (edema) extending more than 5 mm around the puncture wounds.
heel-knee test, heel-shin test, (for coordinated movements of the lower limbs) the patient, lying supine, is asked to touch the knee on one side with the opposite heel and then to pass the heel slowly down the front of the shin to the ankle. Called also heel-to-knee or heel-to-shin t.
heel-tap test, see under reflex.
heel-to-knee test, heel-to-shin test, heel-knee t.
hemadsorption test, an in vitro test for detecting hemagglutinating viruses based on the adherence of red blood cells to cells of the infected tissue in the presence of hemagglutinin.
hemagglutination inhibition (HI, HAI) test, a highly sensitive procedure for the measurement of soluble antigens in biologic specimens in which the specimen is first incubated with homologous antibody and then incubated with antigen-coated red cells; the amount of hemagglutination reflects the amount of free antibody present after reaction with the specimen and thus varies inversely with the amount of antigen in the specimen.a procedure for the measurement of serum antibodies directed against a hemagglutinating virus; the highest dilution of serum that completely inhibits hemagglutination by a standardized viral preparation is reported as the hemagglutination titer.
hemosiderin test, see specific tests, including Perls t. and Rous t.
Henshaw test, a test to aid in the selection of the appropriate homeopathic remedy in a given case of disease. A visible flocculation zone develops in the patient's blood serum when it is brought into contact with a potentized remedy homeopathically indicated in the case.
hepatic function test, liver function t.
Hering test, (for binocular versus monocular vision) the subject looks with both eyes through a tube blackened within and having a thread running vertically across the farther end. A small round body is placed either before or behind the thread. If vision is binocular, the subject can immediately tell whether the ball is nearer than the thread or farther away; if vision is monocular, this distinction cannot be made.
Hess capillary test, tourniquet t. (def. 1).
heterophil antibody test, heterophile antibody test, any of several tests for heterophile antibodies associated with infectious mononucleosis; the most common ones are the monospot test and the Paul-Bunnell-Davidsohn test.
HI test, hemagglutination inhibition t. 
Hickey-Hare test, (for diabetes insipidus) intravenous infusion of hypertonic saline after establishment of water diuresis induces antidiuresis in normal subjects but not in patients with diabetes insipidus.
Hines and Brown test, cold pressor t.
histamine test, histamine flare t.any of several formerly common gastric function tests in which histamine was injected to stimulate gastric secretion and measure output of gastric acid; see also augmented histamine test.a formerly used test for presence of a pheochromocytoma; persons with such a tumor would show first a fall and then a marked rise in blood pressure.
histamine flare test, (for leprosy and postherpetic neuralgia) a drop of 1:1000 histamine acid phosphate solution is placed on the skin and a needle puncture is made through it; the test is positive if there is no erythema flare when the puncture is made within the suspected lesion area, or if the flare stops at the border of the lesion when it is made slightly to the outside of it.
histidine loading test, (for folic acid deficiency) a loading dose of histidine is given, and the resultant urinary excretion of excess formiminoglutamic acid (FIGLU), secondary to decreased amounts of tetrahydrofolic acid, is measured. Called also FIGLU excretion t.
Hitzig test, (for vestibular apparatus) the positive electrode of a galvanic current is applied just in front of the ear being examined while the negative electrode is held in the patient's hand, the patient standing with feet together and eyes closed. A current of 5 milliamperes causes a leaning toward the positive pole in normal persons.
hock test, spavin t.
Hoffmann test, (for tyrosine) add mercuric nitrate to the suspected liquid and boil it; then add nitric acid with a little nitrous acid. A red color is produced if tyrosine is present, and a red precipitate is seen.
Hofmeister test, (for leucine) warm the suspected liquid with mercurous nitrate; if leucine is present, metallic mercury is deposited.(for peptones) mix phosphotungstic and hydrochloric acids; let the mixture stand twenty-four hours, and filter. With this reagent a solution containing peptones with no albumin will afford a precipitate.
Hoppe-Seyler test, (for carbon monoxide in the blood) add to blood twice its volume of a solution of sodium hydroxide of 1.3 specific gravity: normal blood will form a dingy brown mass with a green shade if spread thin on a white surface; but if carbon monoxide is present, the mass is red, and so is the thin layer.(for xanthine) add the substance to be tested to a mixture of chlorinated lime in a porcelain dish; a dark-green ring is formed at first.
horse cell test, monospot t.
Hotis test, (for mastitis in cows) fresh milk containing bromcresol purple is incubated for 24 hours; a positive reaction is the formation of yellow flakes on the sides of the test tube.
Huddleson test, an agglutination test for human brucellosis.
Huhner test, postcoital t.
hydrogen breath test, (for deficiency of lactase or other hydrolases, or colonic overgrowth of bacteria) a known quantity of carbohydrate is administered and the subject's exhalations are trapped and measured at timed intervals; patients unable to digest or absorb carbohydrates in the small intestine will have excess carbohydrates in the colon being broken down there by bacterial fermentation, causing an increase of blood hydrogen and thus of hydrogen exhaled by the lungs.
hydrogen peroxide test, (for blood) a 20 per cent solution of hydrogen peroxide is added to the suspected fluid; if blood is present even in minute proportion, bubbles will rise, forming foam on the surface of the fluid.
hydrostatic test, floating of the lungs of a dead infant when placed in water indicates that the child was born alive; called also Raygat t.
hyperemia test, Moschcowitz t.
hyperventilation test, (for Prinzmetal angina) the patient hyperventilates (breathes rapidly and deeply) for five minutes and an electrocardiogram is recorded before, during, and for ten minutes after this. Abnormal coronary vasoconstriction, demonstrated by ST segment changes, indicates Prinzmetal angina.
hypochlorite-orcinol test, (for glycerol) to 3 mL of the unknown add 3 drops of N/1 sodium hypochlorite solution and boil one minute to drive off chlorine. Then add an equal volume of strong hydrochloric acid and a little orcinol. Boil, and a violet or greenish blue color indicates glycerol or a sugar, or some substance that can be oxidized to a sugar.
hypo-osmotic swelling test, (for viability of sperm) a sperm sample is put into a hypo-osmotic solution; spermatozoa with normal plasma membranes should undergo swelling and curling of their tails. If less than 50 per cent of the spermatozoa show this change, the sample is abnormal.
hypothesis test, an abstract procedure for determining whether a set of observations is consistent with a hypothesis under consideration; it is the theoretical basis of most statistical tests. A hypothesis test decides between two hypotheses, one stating that the effect under investigation does not exist (the null hypothesis, H0), and the other that some specified effect does exist (the alternative hypothesis, Ha or H1), based on the observed value of a test statistic whose sampling distribution is completely determined by H0. When the test statistic falls in a set of values known as the critical region, H0 is rejected. The level of probability of incorrectly rejecting H0 may be set before the data are collected, usually at 0.05 or 0.01; this is called the significance level or α level. It is now more common to report the smallest α at which the null hypothesis can be rejected; this is called the significance probability or P value.
hypoxanthine test, see Kossel t.
IFA test, indirect fluorescent antibody test; see immunofluorescence.
immobilization test, detection of antibody based on its ability to inhibit the motility of a bacterial cell or protozoon.
IMViC test, a series of metabolic tests used as standard procedure to differentiate genera of the Enterobacteriaceae. See also the individual tests.
indican test, see specific tests, including Jaffe t. (def. 2) and Weber t. (def. 2).
indirect antiglobulin test, indirect Coombs' test, see antiglobulin t.
indirect fluorescent antibody test, see immunofluorescence.
indole test, see specific tests, including Nencki t., nitroso-indole-nitrate t., pine wood t., and Salkowski t. (def. 3).
inhalational challenge test, see under challenge.
inkblot test, Rorschach t.
insulin sensitivity test, (to differentiate diabetes mellitus from pituitary and adrenal diabetes) a test dose of exogenous insulin will produce a rapid and marked decrease in blood glucose levels if the pancreas is not secreting enough insulin. A much less dramatic response is produced if hyperglycemia is due to excessive secretion of either anterior pituitary or adrenocortical hormones.
intelligence test, a set of problems or tasks posed to assess an individual's innate ability to judge, comprehend, and reason.
intracutaneous test, intradermal t.
intradermal test, a skin test in which the antigen is injected below the skin. Called also intracutaneous t.
intradermal tuberculin test, a tuberculin test in which tuberculin is injected below the skin; see specific tests, including Heaf t., Mantoux t., and tine t.
intravenous secretin test, secretin t.
inulin clearance test, see under clearance.
iodine test, (for starch) when a compound solution of iodine is added to starch, and especially to an acid or neutral solution of cooked starch paste, a deep-blue color is produced that disappears on heating and reappears on cooling. Erythrodextrin and glycogen give a red color with iodine.
Iowa pressure articulation test, a test of the ability to produce the consonant sounds in isolated words, particularly the pressure sounds.
irresistible impulse test, see under impulse.
ischemic forearm test, (for metabolic myopathies) blood flow in the forearm is impeded using a blood pressure cuff, blocking oxidative phosphorylation and causing dependence on anaerobic processes; normal subjects will show rises in ammonia, lactate, and pyruvate, whereas those with metabolic myopathies will not.
Ishihara test, (for color vision) a vision test making use of a series of pseudoisochromatic plates.
Isojima test, sperm immobilization t.
isopropanol precipitation test, (for unstable hemoglobins) a drop of blood is mixed with the nonpolar solvent isopropanol; most unstable hemoglobins precipitate more readily than other hemoglobins. Addition of potassium cyanide reduces false-positive results.
Ivy test, a bleeding time test in which incisions are made on the forearm, a sphygmomanometer is inflated around the upper arm, and the time until cessation of bleeding is recorded. Called also Ivy method.
Jacquemin test, (for phenol) add to the suspected liquid an equal quantity of aniline and some sodium hypochlorite in solution; a blue color is produced.
Jaffe test, (for creatinine) to the liquid add trinitrophenol and then make alkaline with sodium hydroxide. A red color indicates presence of creatinine.(for indican) to the suspected liquid are added an equal amount of concentrated hydrochloric acid, 1 mL of chloroform, and a few drops of a strong solution of chlorinated soda. The chloroform is colored blue if indican is present.
Janet test, (for differentiating between functional and organic anesthesia) the patient is instructed to say “yes” or “no,” according to whether the examiner's touch is felt. The patient may say “no” in functional anesthesia, but will say nothing in cases of organic anesthesia.
Jorissen test, (for formaldehyde) add 0.5 mL of a 1 per cent solution of phloroglucin in 10 per cent sodium hydroxide to 1 mL of the urine; a bright red color indicates free formaldehyde.
Kato test, (for estimation of worm burden) a standard 50-mg sample of fresh feces is collected, cleared with glycerine, and examined for worms.
Kentmann test, (for formaldehyde) dissolve in a test tube 0.1 g of morphine in 1 mL of sulfuric acid; add, without mixing, an equal volume of the liquid to be tested; in a short time the latter will take on a reddish violet color if any formaldehyde is present.
Kerner test, (for creatinine) acidify the suspected solution and add phosphomolybdic or phosphotungstic acid in solution; if creatinine is present, it will form a crystalline precipitate.
Kibrick test, gelatin agglutination t.
kidney function test, a test of kidney function, such as of renal clearance or of the glomerular filtration rate; see also specific tests, including Fishberg concentration t., radioisotope renal excretion t., Rehberg t., and d-xylose absorption t. Called also renal function t.
King-Devick test, (for evaluation of saccade) the patient looks at a series of charts of numbers that become progressively harder to read, arranged in a flowing manner with increasing space between the numbers. Both errors in reading and speed of reading are included in deriving a score.
Kjeldahl test, (for nitrogen) see under method.
Kleihauer test, Kleihauer-Betke test, acid elution t.
Knott test, (for microfilariae or worm larvae in blood) a blood sample is subjected to lysis in a dilute (2 per cent) formalin solution, followed by centrifugation and examination of the stained sediment for microfilariae or larvae.
Kober test, (for estrogens) when estrogens are treated with a mixture of sulfuric acid and phenolsulfonic acid and then diluted with water, a clear pink color is formed; suitable for qualitative analysis.
Kolmogorov-Smirnov test, a statistical test of goodness of fit of a sample to a specified theoretical distribution function, based on the size of the maximum difference between the cumulative distribution functions of the sample and theoretical distributions and using the exact sampling distribution of this difference to determine the significance level. The test can also be used to determine whether two samples are drawn from the same population by examining the maximum difference between the cumulative distribution functions of the two samples.
Korotkoff test, (for collateral circulation) in aneurysm, if the blood pressure in the peripheral circulation remains fairly high while the artery above the aneurysm is compressed, the collateral circulation is good.
Kossel test, (for hypoxanthine) the liquid to be tested is treated with zinc and hydrochloric acid and with sodium hydroxide in excess; if hypoxanthine is present, a ruby-red color is produced.
Kremer test, SCMC t.
Kruskal-Wallis test, a nonparametric test for ordinal data, comparing three or more groups simultaneously: all data are ranked numerically and then the rank values are summed and averaged for each group. If the null hypothesis that all groups are drawn from the same population is true, then the mean ranks should be similar across all groups.
Kuhlmann test, a modification of the Binet test of intelligence for use in infants.
Külz test, (for β-hydroxybutyric acid) the fermented urine is evaporated to a syrupy consistency, strong sulfuric acid in equal volume is added, and the mixture is distilled. If hydroxybutyric acid is present, α-crotonic acid will be formed, which will crystallize. If, after fermentation, the urine shows dextrorotatory properties, β-hydroxybutyric acid is present.
Kveim test, (for sarcoidosis) a skin test using antigen from human sarcoid tissue injected intradermally; any palpable nodule developing at the inoculation site within 6 weeks is biopsied, and histopathologic evidence of epithelioid cell granulomas constitutes a positive reaction. The test is positive in about 60 to 80 per cent of patients.
Lachman test, an anterior drawer test for cases of severe knee injury, performed at 20 degrees of flexion.
Lancefield precipitation test, a ring precipitation test for identification and classification of streptococci. Group-specific antibody reacts in vitro with group-specific polysaccharide to produce a ring of precipitation where the two reagents react at the interface.
Lang test, (for taurine) the solution to be tested is boiled with freshly prepared mercuric oxide; taurine will cause a white precipitate to appear.
Lange test, (for acetone in urine) 15 mL of urine are mixed with 0.5 to 1 mL of acetic acid, and a few drops of a freshly prepared concentrated solution of sodium nitroprusside added. The mixture is overlaid with ammonia. At the point of junction a characteristic violet ring is formed.
lateral pivot shift test, (for integrity of the anterior cruciate ligament) the patient lies prone with the hip flexed and the knee extended; the examiner gradually flexes the knee while pushing the outside of the knee medially and internally rotating the tibia. A thud or jerk at 300–400 of flexion indicates deficiency of the anterior cruciate ligament.
lantern test, (for color vision) a set of specially devised lanterns are used to test the patient's color vision.
latex agglutination test, latex fixation test, (for presence of antibody) a type of agglutination test in which antigen to a given antibody is adsorbed to latex particles and mixed with a solution to observe for agglutination of the latex.
Lee test, (for rennin) add 5 drops of gastric juice to 5 mL of milk; coagulation should take place in 20 minutes in the incubator.
leishmanin test, (for leishmaniasis)leishmanin is injected intradermally; a positive reaction consists of a palpable nodule developing in 48 to 72 hours and indicates delayed hypersensitivity, but not necessarily immunity, to Leishmania organisms. The positive result appears early in some forms of cutaneous and mucocutaneous leishmaniasis, but only after recovery in the case of visceral leishmaniasis. Called also Montenegro t.
lepromin test, (for certain types of leprosy) after intradermal injection of lepromin (q.v.), a positive reaction consists of either a tuberculin-type reaction at 48 to 72 hours (Fernandez reaction) or a nodular, occasionally ulcerated, lesion at 3 to 4 weeks (Mitsuda reaction). The test is not diagnostic; a large fraction of the normal population exhibits positive reactivity owing to sensitivity to cross-reacting antigens. In individuals known to have leprosy, a positive result on this test is indicative of tuberculoid or borderline tuberculoid leprosy, and lack of reactivity is indicative of lepromatous or borderline lepromatous leprosy.
Lewis and Pickering test, (for peripheral circulation) vasodilation of a part is produced by warming it and applying a sphygmomanometer cuff; return of blood to the part is assessed when the cuff is released.
Lichtheim test, (for aphasia) if a patient is able to indicate the number of syllables in a word he or she cannot utter, it indicates that the cortex is less involved than the association fibers.
Liebermann-Burchard test, (for cholesterol) dissolve the sample in chloroform and add acetic anhydride plus concentrated sulfuric acid; cholesterol can be quantitated by the intensity of the resulting blue-green color.
Liebig test, (for cystine) boil the suspected substance with a sodium hydroxide solution and a little lead sulfide; if cystine is present, the lead sulfide will form a black precipitate.
likelihood ratio test, in statistics, a test using the ratio of the maximum value of the likelihood function from one statistical model to that from another model, a smaller ratio indicating a stronger relationship between the variables.
limulus test, (for gram-negative endotoxin) an extract of blood cells from the horseshoe crab (Limulus polyphemus) is exposed to a blood sample from a patient; if the sample contains gram-negative endotoxin, gelation will occur.
Lindemann test, (for acetoacetic acid in urine) to about 10 mL of urine add 5 drops of 30 per cent acetic acid, 5 drops strong iodine solution, and 2 to 3 mL chloroform, and shake. The chloroform does not change color if diacetic acid is present, but becomes reddish violet in its absence. Uric acid also decolorizes iodine, and if much is present, double the amount of strong iodine solution should be used.
Linder test, see under sign.
lipase test, (for liver function and pancreatitis)lipase levels in the blood are measured; elevated levels are seen in impaired liver function and pancreatitis.
liver function test, see specific tests, such as aminopyrine breath t., fructose tolerance t., galactose breath t., lipase t. (def. 1), methacetin breath t., monoethylglycinexylidide t., Quick t. (def. 1), rose bengal t., and sulfobromophthalein excretion t. Increased levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transpeptidase, and 5´-nucleotidase, and decreased levels of bilirubin, are often seen with impaired liver function.
log-rank test, a statistical test used to test the null hypothesis that two groups have the same distribution of survival by analyzing and comparing the number of observed and expected deaths for each group each time a death occurs in either group.
Lombard test, a test for simulated deafness using a noise maker.
Lücke test, (for hippuric acid) add boiling hot nitric acid, evaporate, and heat the dry residue; a strong odor of nitrobenzene proves the presence of hippuric acid.
Lundh test, (for pancreatic function) a liquid test meal is administered, containing protein, fat, and sugar; the trypsin concentration in duodenal aspirates is then measured for several hours. A decrease in trypsin concentration indicates abnormally low pancreatic secretion. Called also Lundh test meal.
lupus band test, an immunofluorescence test to determine the presence and extent of immunoglobulin and complement deposits at the dermal-epidermal junction of skin specimens from patients with systemic lupus erythematosus.
lymphocyte proliferation test, a functional test of the ability of lymphocytes to respond to mitogens, specific antigens, or allogenic cells. Lymphocytes are cultured both with and without the stimulant for several days and then are cultured for several hours with 3H-labeled thymidine. The ratio of the thymidine uptake in the stimulated and control cultures is reported as the “stimulation index” (SI) or “stimulation ratio” (SR). The test with allogenic cells, called a mixed lymphocyte culture (MLC), is commonly performed for transplantation tissue typing; all three types of stimulants are used in investigation of immunodeficiency. Commonly used mitogens are phytohemagglutinin (PHA), concanavalin A (ConA), and pokeweed mitogen (PWM); commonly used antigens are PPD (tuberculin), Candida antigen, and streptokinase-streptodornase. Called also blastogenesis assay and lymphocyte proliferation assay.
Machado-Guerreiro test, (for Chagas disease) a complement fixation test, using as antigen an extract of the spleen of puppies infected with Trypanosoma cruzi.
McMurray test, (for torn meniscus) the patient lies supine with knee fully flexed and foot flat on the table near the buttocks. The examiner stabilizes the flexion with the thumb and index finger, then holds the heel with the other hand, rotates the patient's foot fully outward, and slowly extends the knee to a 900 angle; a palpable or audible “click,” grinding, pain, or limitation of extension indicates a tear of the medial meniscus of the knee joint. The lateral meniscus is tested by repeating the maneuver but rotating the foot inward.
McNemar test, a modified chi-squared test performed on data with one degree of freedom to compare findings in a matched analysis or in a before and after study on the same individual.
MacWilliam test, (for albumin) take 20 mL of urine and add 2 drops of a saturated solution of sulfosalicylic acid: if albumin is present, a cloudiness or precipitate will be seen; if other proteolytic digestion products are present, this precipitate will disappear on boiling, but appear again on cooling.
Magpie test, (for salts of mercury) stannous chloride is added to the suspected solution; a white and gray precipitate is formed, consisting of metallic mercury and mild calomel.
maintenance of wakefulness test, measurement of the length of time for which an individual can remain awake in a dark, quiet room; used as a measure of physiological sleepiness.
mallein test, a skin test analogous to the tuberculin test, using mallein to test for exposure to glanders.
Malot test, a test for the quantitative determination of phosphoric acid in urine by the reaction with cochineal and a uranium salt.
Mann-Whitney test, Mann-Whitney U test, Mann-Whitney-Wilcoxon test, rank sum t.
Mantoux test, a type of intradermal tuberculin test; 0.1 mL of PPD containing 5 TU is administered, usually into the forearm; the size of the area of any induration on the second or third day, combined with risk factors, is used to determine whether the patient has had exposure to or infection with Mycobacterium tuberculosis or a related organism.
manual muscle test, (for muscle function) the therapist manually puts the patient's body part through a range of motion and records the extent of function and limitations.
Marlow test, (for heterophoria) one eye is occluded by a bandage for some time; after the bandage is removed, measurements for heterophoria are made.
Master “2-step” exercise test, (for coronary insufficiency) an early exercise test in which a patient stepped on and off a set of two stairs for a number of trips standardized for age, weight, and sex, with electrocardiograms recorded immediately after test cessation. It has been supplanted by graded exercise tests that can induce higher levels of stress.
Matas test, (for collateral circulation) after hyperemia of the limb has been induced with a tourniquet, the tourniquet is removed and the extent of collateral circulation is determined by compressing the main artery. Called also tourniquet t.
maximal exercise test, an exercise test that continues until the maximal capability of the subject to exercise has been reached; the endpoint is usually subjective fatigue, shortness of breath, or chest pain.
Mayer test, (for alkaloids) mercury bichloride, 13.5 g, and potassium iodide, 50 g, are dissolved in 1000 mL of water; this is used as a test for alkaloid, with which it gives a white precipitate.
Mayerhofer test, (for tuberculous meningitis) the reduction of a decinormal solution of potassium permanganate solution by 1 mL of spinal fluid in an acid medium is an index of the amount of protein substance present in the fluid, indicating tuberculous meningitis.
Mazzotti test, (for onchocerciasis) a small dose of diethylcarbamazine is administered orally; the death of microfilariae in the skin causes an intensely pruritic rash within 20 minutes to 24 hours.
MEGX test, monoethylglycinexylidide t.
Meigs test, (for fat in milk) to 10 mL of milk in a special apparatus add 20 mL of water, 20 mL of ethyl ether, and shake. Then add 20 mL of 95 per cent alcohol. Remove the ethereal layer, evaporate, and weigh.
melanin test, see Thormählen t.
mercury test, see specific tests, including Magpie t., Reinsch t., and Vogel and Lee t.
methacetin breath test, a breath test of liver function: the fasting patient is administered a dose of methacetin labeled with heavy carbon (carbon 13) and breath levels of carbon dioxide are measured at regular intervals; low levels of carbon dioxide indicate liver dysfunction such as cirrhosis.
methyl red test, (for differentiation of Enterobacteriaceae) the organism is inoculated into a buffered glucose-peptone broth containing methyl red. In a positive reaction, the medium remains red after incubation owing to acid metabolic products. Most Enterobacteriaceae are positive; the Klebsielleae are negative and Erwinieae are variable.
metyrapone test, (for Cushing syndrome) plasma 11-deoxycortisol or urinary 17-hydroxycorticosteroids are measured after the administration of metyrapone; levels are increased in patients with Cushing disease but not in patients with ectopic ACTH syndrome.
microprecipitation test, a precipitin test in which a minute quantity of the serum is employed.
MIF test, migration inhibitory factor test, an in vitro test for the production of migration inhibitory factor (MIF) by lymphocytes in response to specific antigens; used for evaluation of cell-mediated immunity. MIF production is absent in certain immunodeficiency disorders, such as DiGeorge syndrome, Wiskott-Aldrich syndrome, and Hodgkin disease.
milk ring test, abortus Bang ring t.
40 millimeter test, (for athletic efficiency) the subject sits with nasal respiration occluded with a clamp, and by expiring through a mouthpiece, sustains a column of mercury at the height of 40 mm for as long as possible. The pulse rate is taken meanwhile, every five seconds. In a satisfactory test the pulse rate is unaltered for a minute or more.
Millon test, (for proteins and nitrogenous compounds) a solution of 10 g of mercury and 20 g of nitric acid is diluted with water and decanted after standing 24 hours. This reagent gives a red color with proteins and other substances, such as tyrosine, phenol, and thymol, which contain the hydroxyphenyl group.
Mills test, (for tennis elbow) with the wrist and fingers fully flexed and the forearm pronated, complete extension of the elbow is painful.
Mitsuda test, lepromin t.
Mittelmeyer test, (for vestibular disorders) the patient tries to march in place with eyes closed; in vestibular disorder he or she will turn to the side ipsilateral to vestibular loss, or contralateral to vestibular excitation.
mixed lymphocyte culture test, see under culture, and see lymphocyte proliferation t.
mixed triglyceride breath test, a breath test for pancreatic function; a mixture of synthetic triglycerides labeled with carbon 13 is administered to the fasting patient and levels of labeled carbon dioxide in the breath are subsequently measured at regular time intervals; excessively low carbon dioxide indicates inadequate pancreatic lipase in the intestine.
MLB test, monaural loudness balance t.
Molisch test, (for glucose in urine) add 2 mL of urine, 2 drops of a 15 per cent solution of thymol, and an equal volume of strong sulfuric acid; a deep red color results. Called also Molisch reaction.(for glucose in urine) to 1 mL of urine add 2 or 3 drops of a 5 per cent solution of α-naphthol in alcohol, then add 2 mL of strong sulfuric acid; a deep violet color is produced, and a violet precipitate follows if water is added.(for proteins) the substance is treated with a 15 per cent alcoholic solution of α-naphthol and then with concentrated sulfuric acid; a violet color is formed if proteins are present. Called also Molisch reaction; defs. 2 and 3 called also alpha-naphthol reaction.
Moloney test, (for delayed sensitivity to diphtheria toxoid) 0.1 mL of 1:10 dilution of fluid toxoid is injected intradermally on the flexor surface of the forearm; the appearance in 12 to 24 hours of an area of redness with induration of more than 12 mm in diameter is a positive reaction.
monaural loudness balance test, (for hearing)MLB test; a test that measures recruitment in bilateral sensorineural hearing loss; the loudness sensation at impaired frequencies is compared with that at normal frequencies.
monoethylglycinexylidide test, (for liver function)MEGX test; the plasma concentration of monoethylglycinexylidide (MEGX) is measured 15 or 30 minutes after the intravenous injection of lidocaine; MEGX levels are reduced in impaired liver function.
mononucleosis spot test, monospot test, a type of heterophile antibody test for infectious mononucleosis, a modification of the Paul-Bunnell-Davidsohn test, using horse erythrocytes instead of sheep erythrocytes; no centrifugation step is needed and the whole test is performed in minutes.
Montenegro test, leishmanin t.
Morelli test, (to differentiate between an exudate and a transudate) add a few drops of the suspected fluid to a saturated solution of mercury bichloride in a test tube; a flaky precipitate indicates a transudate, a clot indicates an exudate.
Mörner test, (for tyrosine) to a small quantity of the crystals in a test tube add a few mL of Mörner reagent (solution of formaldehyde, 1 mL; distilled water, 45 mL; concentrated sulfuric acid, 55 mL). Heat gently to the boiling point. A green color shows the presence of tyrosine.see nitroprusside t. (def. 1).
Morton test, (for metatarsalgia) transverse pressure is exerted across the heads of the metatarsals; in metatarsalgia this will cause a sharp pain, especially between the second and third metatarsals.
Moschcowitz test, (for arteriosclerosis) the lower limb is rendered bloodless by means of an Esmarch bandage, which is removed after five minutes; in a normal limb the color returns in a few seconds, but in an arteriosclerotic one color returns more slowly. Called also hyperemia t.
multiple-puncture test, a skin test in which the material used (e.g., tuberculin) is introduced into the skin by pressure of several needles or pointed tines or prongs. See also tine t. and Heaf t.
multiple sleep latency test, measurement of the speed at which an individual falls asleep when given multiple opportunities to sleep throughout the day and instructed not to resist doing so; used as a measure of physiological sleepiness.
mumps skin test, (for immunity to mumps) an intradermal test formerly widely used to determine previous exposure to mumps virus; killed virus (mumps skin test antigen) is injected intradermally; a positive response is development of tuberculin-type delayed hypersensitivity.
murexide test, Weidel t. (def. 1).
Murphy test, (for location of deep-seated muscular pain) the patient sits with arms folded in front; the examiner's thumb is placed under the twelfth rib and short jabbing movements are made to determine the origin of deep-seated tenderness and muscular rigidity. Called also Murphy kidney punch.
Naffziger test, (for nerve root compression) increase or aggravation of pain or sensory disturbance over the distribution of the involved nerve root upon manual compression of the jugular veins bilaterally confirms the presence of an extruded intervertebral disk or other mass.
Nagel test, (for color vision) one half of the field of an anomaloscope is illuminated with standard yellow and the subject must mix red and green until the second half matches the first.
Nagler test, see under reaction.
NBT test, nitroblue tetrazolium t.
Nencki test, (for indole) treat the suspected material with nitric acid and a little nitrous acid; a red color follows, and in concentrated solution a red precipitate may appear.
neostigmine test, (for myasthenia gravis) used in children, and in adults suspected of having myasthenia gravis but with a negative Tensilon test; neostigmine methylsulfate mixed with atropine sulfate is injected intramuscularly; lessening of myasthenic symptoms is indicative of the disease. Called also Prostigmine t.
Neufeld test, see under reaction.
neutralization test, a test for the power of an antiserum, antibiotic, antitoxin, antiviral, or other substance to antagonize the pathogenic properties of a microorganism, virus, bacteriophage, or toxic substance. Called also protection t. and serum neutralization t.
niacin test, (for Mycobacterium tuberculosis) either of two tests to distinguish strains of M. tuberculosis by adding aniline, ethanol, and cyanogen bromide to a culture; this will turn human M. tuberculosis yellow because of its niacin content.
Nickerson-Kveim test, Kveim t.
Ninhydrin test, triketohydrindene hydrate test.
nitrate reduction test, (for bacteriuria or presence of bacteria in other fluids) a type of nitrite test that identifies the reduction of nitrate to nitrite by a bacterial culture. The fluid under investigation is cultured in a broth containing nitrate and the medium is tested for nitrite by mixing with solutions containing sulfanilic acid and alpha-naphthylamine in 5 N acetic acid; a red color indicates the presence of nitrite. The test is useful in identifying doubtful strains of Enterobacteriaceae, mycobacteria, and certain aerobic bacteria.
nitrite test, (for nitrites in saliva) to the saliva add 1 or 2 drops of sulfuric acid, a few drops of potassium iodide solution, and some starch paste; a blue color indicates nitrites.a test for nitrites in any fluid; see specific tests, including Griess t., nitrate reduction t., and Schaffer t.
nitroblue tetrazolium test, (for neutrophil microbicidal function) neutrophils are incubated with latex particles and nitroblue tetrazolium (NBT). Normally phagocytosis of the particles is accompanied by reduction of NBT to a blue formazan pigment; absence of NBT reduction indicates a defect in some of the metabolic pathways involved in intracellular microbial killing, as seen in chronic granulomatous disease. Called also NBT t.
nitrogen washout test, (for functional residual capacity of lungs) with the patient inhaling pure oxygen, the concentration of exhaled nitrogen is obtained for each breath until it falls below 1 per cent of the gas being exhaled (usually about seven minutes' time); the total volume of nitrogen that has been exhaled at this point is assumed to be 0.8 of the functional residual capacity.
nitrogen washout test, single breath, the patient inhales a vital capacity's volume of pure oxygen and then slowly exhales. The nitrogen concentration of the exhaled gas is measured over the entire breath and a curve is generated; different parts of the curve represent nitrogen concentrations of gas in different components of the vital capacity, and can be analyzed for uniformity of ventilation and determination of anatomic dead space and closing volume. Called also single breath t. and single breath oxygen t.
nitroprusside test, (for cysteine) if a protein containing cysteine is dissolved in water and 2 to 4 drops of a 4 or 5 per cent solution of sodium nitroprusside and then a few drops of ammonia are added, a deep purple-red color appears; called also Mörner t.(for creatinine) see Weyl t. (def. 1).
nitroso-indole-nitrate test, (for indole and skatole) acidify the unknown with nitric acid and add a few drops of potassium nitrite; a red color or a red precipitate indicates indole, a white turbidity indicates skatole.
nocturnal penile tumescence test, monitoring of erections occurring during sleep; in the differential diagnosis of psychogenic and organic impotence, the former is generally associated with the presence of normal patterns of nocturnal erection while the latter is not. Called also NPT t..
nonparametric test, one using nonparametric statistics, such as the rank sum test or signed rank test; nonparametric tests are often less powerful than parametric tests but are valid in cases where parametric tests are not.
nonstress test, the monitoring of the response of the fetal heart rate to fetal movements by cardiotocography; a reactive (normal) test consists of two or more fetal movements occurring within 20 minutes accompanied by acceleration of the fetal heart rate by at least 15 beats per minute for at least 15 seconds with a long-term variability of at least 10 beats per minute.
nontreponemal antigen test, see serologic t. for syphilis.
NPT test, nocturnal penile tumescence t.
nucleic acid test, any of various tests that use molecular biology techniques to detect and identify microorganisms, including viruses, on the basis of their nucleic acids. It includes culture confirmation tests, which identify organisms grown in culture, and direct tests, which can identify the organisms directly in a specimen. Direct tests can be further subdivided on the basis of whether their target nucleic acids are nonamplified or amplified for the test; the former are based on identification of a unique target sequence using a labeled probe; the latter are classified as nucleic acid amplification tests (q.v.).
nucleic acid amplification test, any nucleic acid test (q.v.) that uses nucleic acid amplification techniques in a direct test for the presence of a specific pathogen in a sample; such tests do not depend on the production of antibody by the pathogen, and can be rapid, highly sensitive, and very specific.
nystagmus test, caloric t.
Oakley-Fulthorpe test, see under technique.
Ober test, (for hip contracture) the patient lies on the side opposite that to be tested, with the underneath hip and knee flexed; with the upper knee flexed to a right angle, the upper hip is flexed to 90 degrees, fully abducted, brought into full hyperextension, and allowed to adduct; the angle that the thigh makes above the horizontal is the degree of abduction contracture.
occult blood test, see specific tests, including guaiac t., and Hemoccult.
octanoic acid breath test, a breath test for gastric emptying: the patient is administered a test meal containing octanoic acid labeled with carbon 13, and the breath is assessed at intervals for levels of labeled carbon dioxide; excessive carbon dioxide is seen when gastric emptying is inadequate.
one-stage prothrombin test, one-stage prothrombin time test, prothrombin time.
one-tailed test, a hypothesis test (q.v.) in which the critical region is one tail of the distribution of the test statistic and the null hypothesis is tested against a one-sided alternative that includes deviations from the null hypothesis only in one direction, deviations in the other direction being of no consequence.
ONPG test, (for β-galactosidase in bacteria) the organism is grown in a buffered peptone medium containing d-nitrophenyl-β-d-galactopyranoside (ONPG): production of β-galactosidase is indicated by the appearance of a yellow color. Used to differentiate Salmonella (positive) from Arizona (negative), and Neisseria lactamicus (positive) from N. meningitidis (negative).
opticokinetic drum test, optokinetic test, optokinetic drum test, (for vision) a rotating drum or other figure is used, painted with vertical black and white stripes; because the eye involuntarily follows such a figure, this can be used in the differential diagnosis of psychogenic blindness, to detect the presence of vision in infants, and to check for normality of opticokinetic nystagmus.
orcinol test, Bial t.
orientation test, testing whether the patient can correctly give the time of day, the day of the week, month, and year, and the place.
osmotic fragility test, (for spherocytosis) heparinized or defibrinated blood is placed in tubes of sodium chloride solution (pH 7.4) varying in concentration from 0.85 to 0.00 per cent (w/v); the amount of hemolysis in each tube is determined colorimetrically. Increased fragility indicates spherocytosis.
Osterberg test, (for β-hydroxybutyric acid) to 800 mg of ammonium sulfate add 0.15 mL of concentrated ammonium hydroxide solution, 2 drops of a 5 per cent solution of nitroprusside, and 1 mL of the urine. Dilute to 50 mL and compare with a standard.
Ouchterlony test, double diffusion in two dimensions; see under diffusion.
Oudin test, see under technique.
oxytocin challenge test, a contraction stress test in which uterine contractions are stimulated by intravenous infusion of oxytocin.
Pachon test, (for collateral circulation) measuring of the blood pressure in cases of aneurysm to determine the state of the collateral circulation.
Paget test, a solid tumor is most hard in its center, whereas a cyst is least hard in its center.
pancreatic function test, see specific tests, such as bentiromide t., cholecystokinin t., Lundh t., mixed triglyceride breath t., pancreolauryl t., secretin t., and triolein breath t.
pancreolauryl test, (for pancreatic function)fluorescein dilaurate is administered orally and its cleavage to yield lauric acid is monitored as a measure of pancreatic esterase activity.
Pap test, Papanicolaou test, an exfoliative cytological staining procedure for detection and diagnosis of various conditions, particularly malignant and premalignant conditions of the female genital tract (cancer of the vagina, cervix, or endometrium). Cells that have been desquamated from the genital epithelium are obtained by smears, fixed and stained, and examined under the microscope for evidence of pathologic changes. The test is also used in detection of human papillomavirus infection, evaluation of endocrine function, and diagnosis of malignancies of other organs, such as the breast or organs of the respiratory tract and lungs, gastrointestinal tract, or urinary tract. Called also Pap or Papanicolaou smear. See also Papanicolaou stain, at Stains and Staining Methods under stain.
parametric test, one using parametric statistics, i.e., one that depends upon assumptions about the distribution of the data.
partial thromboplastin time test, see under time.
passive cutaneous anaphylaxis test, see passive cutaneous anaphylaxis, under anaphylaxis.
passive protection test, a test in which antiserum is tested for protective antibody by parenteral inoculation of groups of animals with graded doses in constant volume.
passive transfer test, see Prausnitz-Küstner reaction, under reaction.
patch tests, skin tests, used primarily in the diagnosis of allergies, in which small pieces of gauze or filter paper impregnated with suspected allergens are applied to the skin for fixed time periods; swelling or redness constitutes a positive reaction.
Patrick test, (for arthritis of the hip) with the patient supine, the thigh and knee are flexed and the external malleolus is placed over the patella of the opposite leg; the knee is depressed, and if pain is produced, arthritis of the hip is indicated. Patrick called this test fabere sign, from the initial letters of movements that are necessary to elicit it, namely, flexion, abduction, external rotation, extension.
Paul-Bunnell test, the original heterophile antibody test, which determined the highest dilution of the patient's serum that was capable of agglutinating sheep red blood cells.
Paul-Bunnell-Davidsohn test, a type of heterophile antibody test for infectious mononucleosis, a modification of the Paul-Bunnell test that differentiates among three types of heterophile sheep erythrocyte agglutinins: those associated with infectious mononucleosis, those associated with serum sickness, and natural antibodies against Forssman antigen. The patient's serum is absorbed with guinea pig kidney cells or with beef erythrocytes and centrifuged. Unabsorbed serum has an abnormally high heterophile antibody titer in infectious mononucleosis and serum sickness. Absorption with guinea pig kidney removes Forssman antibodies and serum sickness heterophile antibodies. Absorption with beef erythrocytes removes heterophile antibodies associated with infectious mononucleosis and serum sickness. Called also Davidsohn differential absorption t.
PCA test, see passive cutaneous anaphylaxis.
pentagastrin test, pentagastrin stimulation test, (for gastric function) after the patient fasts overnight, a basal acid output and its pH are obtained for secretion of stomach acid. Then pentagastrin is administered into the stomach through a nasogastric tube and maximal acid output and peak acid output values are obtained. See basal, maximal, and peak acid outputs, under output.
peptide test, see triketohydrindene hydrate t.
peptone test, see specific tests, including Hofmeister t. (def. 2) and triketohydrindene hydrate t.
perchlorate discharge test, a thyroid function test; one to two hours after administration of radioiodine, perchlorate is administered to block further iodine uptake and flush from the thyroid gland any that has not bound to thyroid proteins. In euthyroid patients only trace amounts will be flushed out; the discharge of significant amounts indicates a defect in thyroid iodine binding.
performance test, an intelligence test in which the subject is required to carry out certain actions rather than to answer questions.
Peria test, Piria t.
peritoneal equilibration test, (for adequacy of peritoneal dialysis) after a certain specific dwell time of the dialysis solution, ratios are calculated of the difference in plasma and dialysis solution concentrations of solutes such as creatinine, glucose, other small solutes, and proteins at different times during the remainder of the procedure.
Perls test, (for hemosiderin) the substance being examined is treated with hydrochloric acid and potassium ferrocyanide; the Prussian blue reaction is produced if hemosiderin is present.
permanganate test, see Weisz t.
Perthes test, (for collateral circulation in patients with varicose veins) a bandage is applied just below the knee and the patient walks around with it on; varicose veins of the leg will become evacuated from continuous compression if there is sufficient collateral circulation in the deep veins. Called also tourniquet t.
phenacetin test, (for phenacetin in urine) to the urine add a little concentrated hydrochloric acid, a small amount of 1 per cent solution of sodium nitrate, and a small amount of alkaline α-naphthol solution; make alkaline and a red color indicates phenacetin.
phenol test, see specific tests, including Jacquemin t.
phenolphthalein test, (for blood) boil a thin fecal suspension, cool, and add it to half as much reagent (made by dissolving 1 to 2 g of phenolphthalein and 25 g of potassium hydroxide in water). Add 10 g of metallic zinc and heat until decolorized. A pink color indicates the presence of blood.(in urine) make the urine alkaline; a red color indicates phenolphthalein.
photopatch test, a type of patch test for assessing the photosensitization potential of medications and other chemicals. On the patient's back, each substance is applied in two different locations; then one spot of each substance is irradiated. A positive reaction at only the irradiated site of a substance indicates photoallergy; reaction at both the irradiated and the nonirradiated sites indicates a different type of allergic reaction.
pinch test, (for hand dexterity) a test measuring any of the various pinches of the hand.
pine wood test, (for indole) a pine splinter moistened with concentrated hydrochloric acid is turned cherry red by a solution of indole.
Piria test, (for tyrosine) moisten the suspected material with strong sulfuric acid and warm it; then dilute and warm it again; neutralize it with barium carbonate, filter, and add ferric chloride in dilute solution: if tyrosine is present, a violet color is seen, which is destroyed by an excess of ferric chloride. Also spelled Peria t.
Pirquet test, a formerly much used tuberculin test in which the tuberculin is applied by scarification; called also Pirquet reaction.
pivot shift test, see under phenomenon.
P-K test, see Prausnitz-Küstner reaction, under reaction.
plantar ischemia test, (for circulatory disturbances in legs and feet) the elevated leg is alternately flexed and extended and the plantar surface of the patient's foot is checked for blanching.
pointing test, Bárány pointing t.
Politzer test, see under method.
porphobilinogen test, a test for the presence of porphobilinogen; see Watson-Schwartz t.
Porteus maze test, a performance test in which the subject is required to trace with a pencil through printed mazes of increasing difficulty.
postcoital test, (for infertility) examination of secretions aspirated from the vaginal fornix and endocervical canal after coitus, to determine the number and condition of spermatozoa present and the extent to which they have penetrated the cervical mucus. Called also Huhner t. and Sims t.
posterior drawer test, see drawer t's.
Prausnitz-Küstner test, see under reaction.
precipitin test, any serologic test based on a precipitin reaction (q.v.).
pregnancy test, a test for detection or confirmation of pregnancy; currently it is usually an immunologic test measuring the level of human chorionic gonadotropin in the urine, which rises to detectable levels soon after fertilization; see also early pregnancy t.
Preyer test, a spectroscopic test for carbon monoxide in the blood.
Proetz test, (for acuity of sense of smell) use of a series of substances each in 10 different concentrations in a liter of petroleum of specific gravity 0.880, to determine the least concentration at which the substance can be recognized, termed olfactory coefficient or minimal identifiable odor.
projective test, any of various tests in which an individual interprets ambiguous stimulus situations, e.g., a series of inkblots (Rorschach t.), according to their own unconscious dispositions, thus yielding information about their personality structure, its underlying dynamics, and possible psychopathology.
Prostigmine test, neostigmine t.
protection test, neutralization t.
protein test, see specific tests, including biuret reaction, Gies biuret t., Grigg t., Reichl t., Schulte t., sulfur t., and triketohydrindene hydrate t.
protein-bound iodine test, a formerly common thyroid function test in which the amount of iodine firmly bound to protein in the serum was determined by precipitating the proteins, yielding an estimate of serum thyroid hormone concentration. Errors were introduced if iodine compounds from nonthyroid sources were present.
protein truncation test, a method for detection of one or more translation termination mutations in a gene that cause a truncated, usually inactive, protein to be synthesized; the appropriate genomic DNA or mRNA is isolated, amplified by polymerase chain reaction, and used as a template for in vitro transcription and translation. The size of the resulting protein is compared to that of a wild type protein by means of SDS–polyacrylamide gel electrophoresis.
prothrombin test, prothrombin time.two-stage prothrombin time t.
prothrombin consumption test, a test formerly much used to measure the formation of intrinsic thromboplastin by determining the residual serum prothrombin after the completion of blood coagulation.
prothrombin-proconvertin test, a test formerly used in the control of coumarin-type anticoagulants, employing a saline extract of brain as a thromboplastin and requiring presence of excess blood coagulation factor V.
provocative test, challenge (def. 3).
psychological test, any test to measure a subject's development, achievement, personality, intelligence, thought processes, etc.
psychomotor test, a test that assesses the subject's ability to perceive instructions and perform motor responses, often including measurement of the speed of the reaction.
pulmonary function test, any of numerous tests that measure aspects of the respiratory system in order to assess functional state and presence or nature of any disease process. Factors evaluated include lung mechanics (capacities, flow rates, and volumes), gas exchange, pulmonary blood flow, blood gases, and pH of blood.
pulp test, a diagnostic test to determine tooth pulp vitality or abnormality, usually by means of electric pulp testers or by application of a hot or cold stimulus.
Queckenstedt test, see under sign.
quellung test, Neufeld reaction; see under reaction.
Quick test, (for liver function) a test based on excretion of hippuric acid following administration of sodium benzoate.prothrombin time.
radioactive iodine uptake test, one of the most common thyroid function tests; a known quantity of radioiodine is administered and 24 hours later the per cent is calculated that has been absorbed by the thyroid gland. Patients who have recently been exposed to iodine compounds, such as in dietary supplements, contrast media, medications, or antiseptics, may not be good candidates for this test.
radioallergosorbent test, a test used to measure specific IgE antibodies in serum. Allergen extract is coupled to a solid matrix (paper, cellulose particles); this immunosorbent is reacted with serum and washed and then reacted with radiolabeled anti–human IgE antibody and washed. Uptake of the labeled antibody is proportional to the level of specific serum IgE antibodies to the allergen. RAST is used as an alternative to skin tests to determine sensitivity to suspected allergens.
radioiodine uptake test, radioactive iodine uptake t.
radioimmunosorbent test, a highly sensitive radioimmunoassay for measuring the total IgE antibody concentration in serum; the serum sample is reacted with radiolabeled IgE and anti–human IgE antibody coupled to an insoluble support. The amount of labeled IgE remaining bound to the immunosorbent varies inversely with the amount of (unlabeled) IgE present in the sample.
radioisotope renal excretion test, (for kidney function) radioisotopic material diluted with saline is rapidly injected into a well-hydrated patient; urine collected through a catheter is examined at known intervals and the radioactivity of each specimen is determined and recorded.
Ramon flocculation test, a test formerly widely used to assess the quality of toxoid-based vaccines; to a series of tubes containing a constant amount of toxin, such as diphtheria toxin, antitoxin is added in increasing amounts; when flocculation occurs, it indicates a neutralized mixture of toxin and antitoxin.
rank sum test, a nonparametric statistical test for ordinal data, testing the null hypothesis that two samples are drawn from the same population versus the alternative hypothesis that the two samples are drawn from two populations having probability distributions of the same shape but different locations. It is based on the value of the rank sum statistic, which is calculated as the sum of the ranks of each sample after the observations in both samples are jointly ranked in ascending order; if and only if the null hypothesis is true, the average ranks of the two samples will be similar. Called also Mann-Whitney U t., Mann-Whitney-Wilcoxon t., and Wilcoxon rank sum t.
rapid plasma reagin test, RPR test; a type of card test that is a flocculation test widely used in screening for syphilis. Unheated serum and a modified VDRL antigen containing choline chloride and charcoal particles are placed on a plastic-coated white card, followed by macroscopic identification of the flocculation.
Raygat test, hydrostatic t.
Rebuck test, Rebuck skin window technique.
red-glass test, (for ocular deviation) a red glass is placed over the right eye while the patient looks at a light; the position at which the patient sees the red image reveals any affected muscle.
Rees test, (for albumin) small amounts of albumin are precipitated from solution by tannic acid in alcoholic solution.
Rehberg test, a formerly used test of creatinine clearance.
Reichl test, (for proteins) add 2 or 3 drops of an alcoholic solution of benzaldehyde and a quantity of sulfuric acid previously diluted to twice its volume with water; then add a few drops of ferric sulfate solution. The mixture will take on a deep-blue color if proteins are present.
Reinsch test, (for heavy metals, including arsenic, mercury, bismuth, antimony, and large amounts of selenium, tellurium, and sulfide) insert a strip of clean copper into the suspected acidified liquid or finely ground tissue, and boil; if one or more heavy metals are present, a coating will form on the copper strip.
renal function test, kidney function t.
resorcinol–hydrochloric acid test, Selivanoff t.
Reuss test, (for atropine) the substance examined is treated with sulfuric acid and oxidizing agents; if atropine is present, an odor of roses and orange-flowers is given off.
rheumatoid arthritis test, see specific tests, such as the latex agglutination t., Rose-Waaler t., and sheep cell agglutination t.
Rideal-Walker test, see under method.
RIF test, Rubin t. (def. 2).
ring test, (for antibiotic activity) the solution is placed in a ring resting on the surface of seeded agar and the size of the surrounding clear area of inhibition indicates the activity.
Rinne test, (for hearing) with the opposite ear masked, vibrating tuning forks of 256, 512, and 1024 Hz alternately have their stems placed on the mastoid process and just outside the external auditory meatus until nothing is heard at one of these positions. When air conduction is greater than bone conduction(positive Rinne test), it indicates normal hearing or sensorineural hearing loss. When bone conduction is greater than air conduction(negative Rinne test), it indicates conductive hearing loss.
Rivalta test, see under reaction.
rollover test, (for risk of preeclampsia in pregnant women) a comparison of blood pressure is made with the woman lying on her left side and on her back; an excessive increase in blood pressure when she rolls to the supine position indicates increased risk of preeclampsia.
Romberg test, (for differentiating between peripheral and cerebellar ataxia) an increase in clumsiness in all movements and in the width and uncertainty of the gait when the patient's eyes are closed indicates peripheral ataxia; no change indicates the cerebellar type. See also Romberg sign, under sign.
Ronchese test, (for ammonia in urine) one based on the action of formaldehyde on ammonia salts. A 10 per cent solution of sodium carbonate is slowly added to urine until the reaction becomes neutral. A 40 per cent solution of formaldehyde is neutralized with a one-fourth normal sodium solution against phenolphthalein until it becomes slightly pink. Then 25 mL of the neutral urine and 10 mL of the neutral solution of formaldehyde are mixed and titrated against decinormal sodium carbonate solution until a deep pink develops. Each mL of the decinormal sodium carbonate solution per 100 mL of urine corresponds to 0.017 g ammonia in 1000 mL of urine.
Rorschach test, a projective test in which the subject is asked to relate his associations to a series of inkblot designs.
Rose-Waaler test, an agglutination test for rheumatoid factor (RF) using tanned sheep red blood cells (SRBC) coated with subagglutinating amounts of rabbit anti-SRBC IgG antibody. These cells agglutinate when exposed to RF (anti-IgG autoantibodies) owing to cross-reaction between human and rabbit IgG.
rose bengal test, (for liver function) a solution of radiolabeled rose bengal sodium I 131 is injected into the bloodstream. It should disappear from the blood rapidly; delayed clearance time points to diminished activity of the liver.
Rosenbach-Gmelin test, (for bile pigment) filter the urine through a very small filter, and put a drop of nitric acid with a trace of nitrous acid on the inside of the filter; a pale yellow spot will appear, surrounded with yellowish red, violet, blue, and green rings.
Rosenthal test, (for blood in urine) add potassium hydroxide solution to the urine, remove the precipitate, and dry it; place a small amount on a slide with a crystal of sodium chloride; apply a coverglass and cause a few drops of glacial acetic acid to flow under it; warm the plate. When it is cool, hemin crystals will appear if blood is present.
Rothera test, (for acetone) to 5 mL of urine add a little solid ammonium sulfate and add 2 to 3 drops of a fresh 5 per cent solution of sodium nitroprusside and 1 to 2 mL of ammonium hydroxide; a purple color forms if acetone is present.
Rous test, (for hemosiderin in urine) the urine sample is centrifuged; to the sediment add 5 mL of a 2 per cent solution of potassium ferrocyanide and 5 mL of a 1 per cent solution of hydrochloric acid. Hemosiderin granules stain blue.
RPR test, rapid plasma reagin t.
Rubin test, (for patency of uterine tubes) transuterine insufflation is done with carbon dioxide. If the tubes are patent the gas enters the peritoneal cavity and may be demonstrated by the fluoroscope or radiograph. This subphrenic pneumoperitoneum may cause pain in one or both shoulders of the patient. If the manometer registers not over 100 mm Hg the tubes are patent; if between 120 and 130, there may be stenosis or stricture, but not complete occlusion; if it rises to 200, the tubes are completely occluded.(for avian leukosis viruses in egg-culture vaccines) if the viruses are present, they induce a cellular resistance to Rous sarcoma viruses subsequently inoculated (resistance-inducing factor). Called also RIF t.
Rubner test, (for carbon monoxide in blood) shake the blood with 4 or 5 volumes of lead acetate in solution: if the blood contains CO, it will retain its bright color; if not, it becomes a chocolate brown.(for lactose, glucose, maltose, or fructose in urine) add lead acetate to the urine, boil, and then add an excess of ammonium hydroxide: lactose gives a brick-red color, glucose a coffee-brown color, maltose a light-yellow color, and fructose no color at all.
ruler test, Hamilton t.
Rumpel-Leede test, see under phenomenon.
Russell viper venom test, Stypven time t.
Ruttan and Hardisty test, (for blood) blood in the presence of a 4 per cent glacial acetic acid solution of orthotoluidine and hydrogen peroxide gives a bluish color.
Sabin-Feldman dye test, (for toxoplasmosis) a serologic test based on the failure of living toxoplasmas, in the presence of specific antibody and accessory factor, to take up methylene blue dye.
saccharimeter test, glucose in solution rotates the plane of polarized light to the right, while fructose turns it to the left.
saccharin test, (for mucociliary clearance) the upper respiratory tract is cleaned and small crystals of saccharin are placed on the inferior nasal mucosa. The time is measured until the patient has a sweet taste in the mouth. With normal ciliary transport the time should be 30 minutes or less; a time of more than 1 hour indicates pathology.
Sakaguchi test, (for arginine) a reddish or wine color is produced in the presence of arginine when a tissue section is treated with an alkaline mixture of α-naphthol and sodium hypochlorite.
Salkowski test, (for carbon monoxide in the blood) add to the blood 20 volumes of water and sodium hydroxide in solution; if CO is present, it becomes cloudy and then red, and eventually flakes of red float on the surface.(for cholesterol) dissolve the sample in chloroform and add an equal volume of strong sulfuric acid; if cholesterol is present, the solution becomes bluish red and slowly changes to a violet red, and the sulfuric acid becomes red, with a green fluorescence.(for indole) to the solution to be tested add a little nitric acid, and drop in slowly a solution of potassium nitrite (2 per cent): a red color shows that indole is present, and a red precipitate is afterward formed.(for creatinine) to the yellow solution obtained in the Weyl test, add an excess of acetic acid and heat; a green color results, which turns to blue.
Sandrock test, (for thrombosis) vigorous friction is applied to the part; the degree of hyperemia which follows is an indication of the condition of the circulation.
scarification test, a skin test in which the antigen is introduced by scarification.
Schaffer test, (for nitrites in urine) decolorize 4 mL of urine with animal charcoal and add to it 4 mL of 10 per cent acetic acid and 3 drops of 5 per cent solution of potassium ferrocyanide; an intense yellow color indicates nitrites.
Schick test, (for reactivity or immunity to diphtheria toxin) an intradermal test in which diphtheria toxin equal to one-fiftieth of the minimum lethal dose for a guinea pig is injected into one of the subject's arms (the test site) and an equal quantity of heat-inactivated diphtheria toxin is injected into the other arm (the control site). A positive reaction consists of redness at the test site only, appearing in 24 to 36 hours and persisting for 4 to 5 days, leaving a brown spot on the skin; this indicates lack of immunity to diphtheria. Immunity is indicated by either a pseudoreaction (redness at both sites, usually disappearing in 48 hours without residual pigmentation) or a negative reaction.
Schiller test, (for cancer of cervix) a test for early squamous cell cancer by treating the tissue with a solution of 1 g of iodine and 2 g of potassium iodide in 300 mL of water: if the cervix is healthy, the surface turns brown; if there is cancer, the treated area turns white or yellow, because cancer cells do not contain glycogen and therefore do not stain with iodine.
Schilling test, (for gastrointestinal absorption of vitamin B12) a measured amount of radioactively labeled cyanocobalamin is given orally, followed by a parenteral flushing dose of the nonradioactive vitamin, and the percentage of radioactivity is determined in the urine excreted over a 24-hour period. The test is usually done three times: first with added intrinsic factor, then without it, and then after antibiotic therapy. The results are used in the diagnosis of pernicious anemia and other disorders of vitamin B12 metabolism.
Schirmer test, (for keratoconjunctivitis sicca) a test of tear production in which a piece of filter paper is inserted over the conjunctival sac of the lower lid, with the end of the paper hanging down on the outside. The range of normal wetting, determined by measuring the area of moisture on the projecting paper, depends on age, sex, and disease processes.
Schlichter test, serum bactericidal activity t.
Schober test, (for range of motion of lumbar spine) with the patient standing erect, marks are drawn 5 cm above and 10 cm below the posterior superior iliac spine; when the patient bends at the waist to the most flexion possible, the distance between the two marks should increase to at least 20 cm; if the distance is less, there is decreased range of motion, such as with ankylosing spondylitis.
Schönbein test, (for blood) blue coloration obtained by adding solution of hydrogen peroxide to tincture of guaiac mixed with suspected blood.(for copper) a solution containing a copper salt becomes blue if potassium cyanide and tincture of guaiac are added.
Schroeder test, (for urea) add a crystal of the substance to a solution of bromine in chloroform; the urea will decompose and gas will be formed.
Schulte test, (for proteins) remove all coagulable protein, precipitate with six volumes of absolute alcohol, dissolve the precipitate in water, and apply the biuret test.
Schultze test, (for cellulose) iodine is dissolved to saturation in a zinc chloride solution, and 6 parts of potassium iodide are added: this reagent colors cellulose blue.(for cholesterol) evaporate with nitric acid, using a porcelain dish and water bath; if cholesterol is present, a yellow deposit is formed, which changes to yellowish red when ammonia is added.
Schumm test, benzidine t.(for heme in plasma) a given volume of plasma is covered with a layer of ether; one-tenth the volume of concentrated ammonium sulfide (analar) is then run in with a pipette and subsequently mixed by shaking. A positive reaction is indicated by the appearance of a hemochromogen with a sharply defined α band at 558 nm in a depth up to 4 cm of plasma.
Schwabach test, (for hearing) with the patient's opposite ear masked, vibrating tuning forks of 256, 512, 1024, and 2048 Hz have their stems placed first on the patient's mastoid process and then on that of the examiner (whose hearing should be normal), until sound is no longer heard by one of them. The result is expressed as “Schwabach prolonged” if heard longer by the patient (indicative of conductive hearing loss), as “Schwabach shortened or diminished” if heard longer by the examiner (indicative of sensorineural hearing loss), and as “Schwabach normal” if heard for the same time by both.
SCMC test, (for cervical factor infertility) fresh sperm is put both on a slide with cervical mucus and on a slide without mucus, and motility of the two sperm samples is assessed over time. If the sperm shows irregularities of motility through the mucus, there is cervical factor infertility. Called also Kremer t..
scratch test, a skin test in which the antigen is applied on a superficial scratch.
screen test, alternate cover t.cover-uncover t.
screening test, any test used to eliminate those who are definitely not affected by the disease in question, the remainder (those with positive reactions) being subjected to more refined diagnostic tests.
secretin test, (for pancreatic function) after intravenous injection of secretin, pancreatic secretions are measured by collection through a tube in the duodenum.(for hypergastrinemia) basal values of gastrin are obtained and secretin is administered intravenously; levels of gastrin are then measured at short intervals to assess whether its secretion is normal or abnormal. Defs. 1 and 2 called also intravenous secretin t. and secretin injection or secretin stimulation t.
secretin-cholecystokinin test, (for pancreatic function) a combination of the secretin test and the cholecystokinin test, measuring pancreatic secretion volume and secretion of bicarbonate, amylase, lipase, and trypsin. Called also secretin-pancreozymin t.
secretin injection test, secretin t.
secretin-pancreozymin test, secretin-cholecystokinin t.
secretin stimulation test, secretin t.
SeHCAT test, (for absorption of bile salts) the bile acid analogue SeHCAT (75 selenium homocholic acid, labeled with radioactive selenium-75) is administered; seven days later, the amount left in the body is measured.
Selivanoff (Seliwanow) test, (for fructose in urine) to the urine is added an equal volume of hydrochloric acid containing resorcinol; formation of a dark red color after boiling for 10 seconds indicates fructose. Called also resorcinol–hydrochloric acid t. and Selivanoff reaction.
sentence completion test, a projective test for assessing personality and possible psychopathology, in which the individual is asked to provide endings for unfinished sentences.
Sereny test, (for invasiveness of bacteria) the organism is inoculated into the eye of a guinea pig; invasiveness is determined by the organism's ability to produce conjunctivitis. The test is used particularly for determining the invasiveness of strains of Escherichia coli and Listeria monocytogenes.
serologic test, a laboratory test involving seroreactions (precipitin reaction, agglutination, complement fixation, etc.), especially one measuring serum antibody titer.
serologic test for syphilis, any test for serum antibodies indicative of Treponema pallidum infection. There are two types: nontreponemal antigen tests detect antibodies to substance (reagin) derived from host tissues, now known to consist of the phospholipids cardiolipin and lecithin; they originated with the Wassermann test and are now represented by the VDRL and RPR (rapid plasma reagin) tests. Treponemal antigen tests detect specific antitreponemal antibodies; they originated with the TPI (T. pallidum immobilization) test and are now represented by the DFA-TP (direct fluorescent antibody–T. pallidum) test, the FTA-ABS (fluorescent treponemal antibody absorption) test, the MHA-TP (microhemagglutination assay–T. pallidum), and assays using ELISA (enzyme-linked immunosorbent assay) methods. The term “serologic tests for syphilis” is occasionally used with reference only to nontreponemal antigen tests.
serum bactericidal activity test, a type of antimicrobial susceptibility test for determining, by serial dilution, the titer of serum (and antimicrobial in serum) that has effective serum bactericidal activity (see under activity). Called also Schlichter t.
serum gastrin test, any test that measures blood levels of gastrin; see fasting serum gastrin, under gastrin.
serum neutralization test, neutralization t.
set test, a screening tool for the presence of dementia.
sex chromatin test, (for determination of chromosomal sex) examination of somatic cells for presence of a Barr body at the periphery of the nucleus; an index of the presence of two X chromosomes, as in a normal XX female, but also giving a positive result with certain chromosomal anomalies. Called also buccal smear t..
shadow test, retinoscopy.
sham feeding test, (for assessment of completeness of a vagotomy) an appetizing meal is served and chewed but not swallowed, stimulating gastric acid secretion solely by vagal pathways; if vagotomy has been successful, there will be no acid secretion.
sheep cell agglutination test, any agglutination test using sheep red blood cells, such as the Rose-Waaler test.
short increment sensitivity index test, see under index.
shuttle walk test, shuttle walking test, an exercise test for cardiac function in which the person walks laps (shuttles) at least 10 meters long on a flat, nonslippery surface, keeping pace with audio signals; there are different levels of difficulty in which the patient walks faster until the point of becoming breathless.
Sia test, (for macroglobulinemia) a simple screening test performed by adding a drop of serum to 10 to 100 mL of cold distilled water; a positive reaction is indicated by the formation of a heaving cloud of precipitate at the bottom of the container. It is not diagnostic, because it may be positive in other conditions, as in rheumatoid arthritis.
sickling test, a method for demonstrating hemoglobin S and sickling in erythrocytes, particularly in the heterozygous state, by reducing the environmental oxygen around them. It may be done by simply sealing a drop of blood under a coverslip or may be speeded up by adding 2 per cent sodium metabisulfite or sodium dithionite to the preparation.
sign test, a nonparametric statistical test based on a null hypothesis that by chance the experimental group should outperform the control group for half the outcome variables and vice versa. Results are scored as a series of pluses and minuses awarded to the experimental group depending on its performance relative to that of the control group, a binomial distribution of scores with p= 0.5 being expected under the null hypothesis.
signed rank test, a nonparametric statistical test for ordinal data, comparing two populations of data by examining the differences between matched pairs in the two populations. It is based on the signed rank statistic, calculated by arranging all samples in order without regard to which population they are drawn from, identifying pairs, assessing the difference in rankings for the members of each pair, and summing these differences for all pairs. If the null hypothesis is true and there is no difference between the two populations, the median difference in rankings between matched pairs in the population approximates 0. Called also Wilcoxon signed rank t.
Sims test, Sims-Huhner test, postcoital t.
single breath test, single breath oxygen test, nitrogen washout t., single breath.
SISI test, see short increment sensitivity index, under index.
skin test, any test in which an antigen is applied to the skin in order to observe the response of the patient, described according to method of application, such as patch tests, scratch tests, and intradermal tests. Skin tests are used to determine prior exposure or immunity to an infectious disease (e.g., tuberculin test), to identify allergens producing allergic reactions, and to assess ability to mount a cellular immune response (using a battery of antigens that give positive test results in most normal individuals).
skin window test, Rebuck skin window technique.
smear test, Papanicolaou t.
Snellen test, (for pretended blindness in one eye) the patient is requested to look at alternate red and green letters; the admittedly sound eye is covered with a red glass and if the green letters are read, evidence of fraud is present.determination of visual acuity by means of Snellen test types.
sniff test, (for paralysis of one side of the diaphragm) the patient sniffs under radiographic examination; with paralysis of part of the diaphragm, the paralyzed half is seen to rise and the intact half to descend.
Solera test, (for thiocyanates) saturate filter paper with 0.5 per cent starch paste containing 1 per cent of iodic acid; dry and preserve as test paper. A piece of this paper moistened with saliva will turn blue if thiocyanate is present.
solubility test, see bile solubility t.
sorting test, (for assessing abstract thinking) the patient must arrange objects or cards into groups based on some abstract relationship. Schizophrenics and patients with cortical lesions show impaired performance.
soybean test, urease t. (def. 1).
spavin test, (for spavin in horses) the limb with the hock is held up and bent sharply; the horse is then started suddenly, and in cases of spavin the first steps are very lame. Called also hock t.
specific gravity test, see specific tests, including Fishberg concentration t. and urine concentration t.
sperm agglutination test, (for male factor infertility) any of various tests for presence of antisperm antibodies as a cause of infertility, based on the fact that large multivalent isotypes such as IgM or secretory IgA may be able to cross-link and agglutinate spermatozoa that have such antibodies. Serum or seminal plasma is mixed with a known concentration of sperm; immunoglobulins in the mixture then begin agglutinating the sperm. After a given period of time at 370C, the amount of agglutination is assessed.
sperm–cervical mucus contact test, SCMC t.
sperm immobilization test, (for male factor infertility) a test for antisperm antibodies as a cause of infertility, based on the fact that spermatozoa with such surface antibodies lose their ability to move if complement is present (as it normally is in the female reproductive tract). Serum from the patient is incubated with motile sperm and complement is added. After one hour the mixture is checked to calculate the percentage of formerly motile sperm that can no longer move; a 50 per cent reduction in motility is a positive result for presence of antisperm antibodies. Called also Isojima t.
sphenopalatine test, the sphenopalatine ganglion is anesthetized with Novocain in order to determine whether the efferent current motivating a symptom is routed through either sphenopalatine ganglion, and if so, whether the left one or the right one.
STA test, standard tube agglutination test, (for brucellosis) a serologic test using Brucella abortus antigens to detect infections with B. abortus, B. melitensis, and B. suis.
Stanford-Binet test, a modification of the Binet test, translated, adapted, and standardized on children in the United States.
starch test, see iodine t. (def. 1).
station test, Romberg t.
Staub-Traugott test, see under effect.
Stein test, (for disease of the labyrinth) inability to stand on one foot with the eyes shut indicates disease of the labyrinth.
Stenger test, (for simulated unilateral hearing loss) a signal is presented at an intensity less than the admitted threshold to the affected ear, and a less intense signal of the same frequency is presented simultaneously to the unaffected ear. If the subject is feigning a loss of hearing, the signal in the unaffected ear will not be heard.
stimulation test, a type of challenge or provocative test used when hypofunction of an endocrine gland is suspected that cannot be detected by other means; either an exogenous releasing hormone or some other substance is administered to stimulate release of the hormone under investigation and levels of it are subsequently measured to assess whether the patient had a normal response.
Stoll test, (for estimation of worm burden) a 24-hour stool specimen is collected and the number of eggs present in an aliquot is calculated.
Straus biological test, Straus reaction; see under reaction.
stress tests, any of various tests that assess cardiovascular health and function after application of a stress to the heart, usually exercise but sometimes others such as atrial pacing, the cold pressor test, or specific drugs. Subjects are monitored electrocardiographically, symptomatically, by blood pressure and heart rate, and often by recordings of ventilation and tidal volume recordings as well as other applicable noninvasive or invasive methods. See also exercise t's.
strychnine test, see Wenzell t.
Student t-test, t-t.
Stypven time test, a prothrombin test similar to the (one-stage) prothrombin time, but performed with Russell viper venom (Stypven) as the thromboplastic agent; useful in defining deficiencies of blood coagulation factor X. Called also Russell viper venom t. or time and Stypven time.
submaximal exercise test, an exercise test halted at a predetermined point that is less than the maximal exercise capability of the subject, usually at a particular percentage of the maximal heart rate or after a set time interval.
sucrose hemolysis test, (for paroxysmal nocturnal hemoglobinuria) the patient's whole blood is mixed with isotonic sucrose solution, which promotes binding of complement to red cells, then incubated and examined for hemolysis; greater than 10 per cent hemolysis is indicative of paroxysmal nocturnal hemoglobinuria.
sugar test, see fructose t. and glucose t.
sulfobromophthalein excretion test, (for liver function)sulfobromophthalein, a dye that in normal individuals is almost completely cleared from the blood by the liver, is administered intravenously and its rate of disappearance from the blood is determined colorimetrically; of historic interest.
sulfur test, (for protein) the suspected liquid is heated with an excess of sodium hydroxide and a small quantity of acetate of lead; if proteins are present, a black precipitate of lead sulfide is formed.
Sullivan test, (for cysteine) to 1 or 2 mL of the unknown solution add 1 to 2 drops of a 0.5 per cent solution of sodium β-naphthoquinone-4-sulfonate and then 5 mL of a 20 per cent sodium thiosulfate made up in 0.25 normal sodium hydroxide. A brilliant red color indicates a free thiol group, demonstrating cysteine rather than cystine.
suppression test, a type of dynamic test used when hyperfunction of an endocrine gland or presence of a hormone-secreting tumor is suspected; a substance is administered that is normally antagonistic to glandular secretion of a given hormone and hormonal levels are measured to assess whether they drop in the normal fashion.
susceptibility test, antimicrobial susceptibility t.
swinging flashlight test, (for damage to the optic nerve or retina) with the patient's eyes fixed at a distance and a strong light shining before the intact eye, a crisp bilateral contraction of the pupil is noted. If when the light is moved to the affected eye, both pupils dilate for a short period, but when it is returned to the intact eye, both pupils contract promptly and remain contracted, this indicates damage to the optic nerve or retina. See also Marcus Gunn pupillary phenomenon, under phenomenon.
syphilis test, see serologic t. for syphilis.
t-test, a statistical hypothesis test based on the t-distribution (q.v.) used to test for a difference between the means of two groups. Called also Student t-t. Written also t test.
taurine test, see Lang t.
Teichmann test, (for blood) the suspected liquid is put under a coverglass with a crystal of sodium chloride and a little glacial acetic acid; heat carefully without boiling and then cool. If blood is present, rhombic crystals of hemin will appear.
Tensilon test, (for myasthenia gravis) after administration of Tensilon (edrophonium chloride), the patient's eye signs (ptosis and extraocular muscle abnormalities) markedly decrease within two minutes in cases of myasthenia gravis.
Terman test, Stanford-Binet t.
thalleioquin test, (for quinine) a neutralized solution of the suspected liquid is treated with chlorine, or bromine water, and then with an excess of ammonia; a green substance, thalleioquin, will be formed.
thallium stress test, (for coronary artery disease) stress is placed on the cardiovascular system by exercising the patient on a treadmill or bicycle ergometer. Thallous chloride Tl-201 is injected intravenously when stress is maximal, just prior to exercise cessation. Immediate (stress) and delayed (redistribution) images are obtained with a gamma camera (see thallium-201 myocardial perfusion scintigraphy); then abnormalities of radionuclide distribution and redistribution are assessed, compared with electrocardiograms obtained during exercise, and used to diagnose areas of ischemia and coronary artery disease. In patients incapable of exercise, stress is induced by injection of dipyridamole or adenosine.
Thematic Apperception Test, a projective test in which the subject tells a story based on each of a series of standard ambiguous pictures; his or her responses reflect a projection of some aspect of the personality and current psychological preoccupations and conflicts.
thin layer rapid use epicutaneous test, TRUE t.
thiocyanate test, see ferric chloride t. and Solera t.
Thomas test, (for flexion contracture of the hip) the patient lies supine and flexes one leg to bring the knee as close to the chest as possible, with the lumbar spine kept flattened. With normal hip function, the opposite leg will remain flat on the table; with flexion contracture, the opposite hip and leg will flex also, with the angle taken approximating the degree of flexion deformity.
Thormählen test, (for melanin in urine) treat urine with a solution of sodium nitroprusside, potassium hydroxide, and acetic acid; if melanin is present, a deep blue color will form.
thromboplastin generation test, a test formerly used in the detection of defects in formation of prothrombinase and hence deficiencies of the factors involved.
Thudichum test, (for creatinine) add to the suspected substance a dilute solution of ferric chloride; a dark red color indicates the presence of creatinine.
thumbnail test, (for fractured patella) the examiner's thumbnail is passed over the subcutaneous surface of the patella; a fracture will be felt as a sharp crevice.
thyroid function test, any of various diagnostic procedures measuring the functioning of the thyroid gland, such as the perchlorate discharge test, protein-bound iodine test, radioactive iodine uptake test, thyroid-stimulating hormone test, thyroid suppression test, thyrotropin-releasing hormone test, triiodothyronine resin uptake test, and measurement of pertechnetate uptake.
thyroid-stimulating hormone test, thyroid-stimulating hormone stimulation test, TSH test; a thyroid function test in which thyrotropin (thyroid-stimulating hormone) is administered intramuscularly and the thyroid gland is monitored over time with scintiscanning or radioimmunoassays for a response or areas of decreased responsiveness. The test was formerly also much used for determining whether hypothyroidism was caused by thyroid gland failure or by deficiency in thyrotropin. Called also TSH stimulation t.
thyroid suppression test, a thyroid function test; after administration of liothyronine for several days, radioactive iodine uptake is decreased in normal persons but not in those with hyperthyroidism.
thyrotropin-releasing hormone test, thyrotropin-releasing hormone stimulation test, a thyroid function test that assesses pituitary release of thyrotropin; a bolus of thyrotropin-releasing hormone is administered and serum concentrations of thyrotropin are assessed at intervals; if serum levels do not increase within 30 to 40 minutes, the pituitary thyrotrophs are dysfunctional. Called also TRH stimulation t.
tilt test, tilt table test, measurement of various bodily responses while the patient is tilted to different angles on a tilt table, usually head up, such as monitoring of circulatory, cardiac, and neurologic responses.
tine test, tine tuberculin test, a type of intradermal tuberculin test; four small tines on a plastic handle, coated with dip-dried tuberculin, are pressed into the outer layer of skin on the forearm. The skin is checked 48 to 72 hours later for induration; if the induration around one or more of the puncture wounds is 2 mm or more in diameter or if there is vesiculation, the test is considered positive. If positive, it is usually confirmed with the more specific Mantoux test (q.v.).
Tizzoni test, (for iron in tissues) treat a section of tissue with a 2 per cent solution of potassium ferrocyanide, and then with a 0.5 per cent solution of hydrochloric acid; the tissue will stain blue if iron is present.
Tobey-Ayer test, (for sinus thrombosis) the jugular vein on the side of the suspected thrombosis is compressed. A rise in spinal fluid pressure should occur; its absence indicates presence of thrombosis. Called also Ayer-Tobey t.
tolbutamide test, (for insulinoma) one gram of tolbutamide is administered intravenously and plasma levels of glucose and insulin are monitored for 3 hours; prolonged hypoglycemia with hyperinsulinemia indicates presence of an insulinoma.
tolerance test, an exercise test to determine the efficiency of the circulation.a test to determine the body's ability to metabolize a substance or to endure administration of a drug.
Tollens, Neuberg, and Schwket test, (for uronic acid) extract the uronic acid from acidified urine with ether, add water, evaporate the ether, and perform an orcinol test.
tone decay test, (for hearing) with an audiometer; the patient is asked to raise one hand as long as she or he hears a continuous tone at threshold level and to lower it when the tone becomes inaudible; whenever the patient lowers the hand before 60 seconds, the intensity is raised by 5 decibels and the amount of tone decay from the initial threshold level in decibels is determined.
tourniquet test, (for capillary fragility) pressure is applied midway between diastolic and systolic for 5 minutes by a manometer cuff; the cuff is released and petechiae are counted in an area 2.5 cm in diameter, on the inner aspect of the forearm. A number between 10 and 20 is marginal; above 20 is abnormal. Called also capillary fragility t. and Hess capillary t.Matas t.Perthes t.
toxigenicity test, (for toxigenic strains of Corynebacterium diphtheriae) a primary culture is streaked onto a plate of tellurite agar containing a strip of filter paper perfused with diphtheria antitoxin. The exotoxin produced by the bacteria forms a band of precipitation with antitoxin diffusing from the filter paper. Called also Elek t.
Toynbee test, (for patency of the auditory tube) the Toynbee maneuver is done, and pressure changes in the middle ear are monitored. Middle ear negative pressure or negative pressure followed by ambient pressure usually indicates normal function of the auditory tube.
TPI test, Treponema pallidum immobilization t.
trapeze test, (for types of spinal deformities) when the patient hangs from a trapeze, a spinal deformity will disappear if it is postural but will remain if it is structural.
tray agglutination test, a type of sperm agglutination test in which a small amount of sperm and serum is mixed on a microscopic tray for examination. Called also Friberg t.
treadmill exercise test, treadmill stress test, any of various graded exercise tests in which the patient walks on an inclined treadmill, which is generally increased in speed and incline through the test; see also specific test protocols, e.g., Bruce protocol. Cf. bicycle ergometer exercise t.
Trendelenburg test, (for varicosity and condition of heart valves) the leg is raised above the level of the heart until the veins are empty, and then quickly lowered. If the veins become distended at once, varicosity and valve incompetence are indicated.(for gluteus medius function) the patient, standing erect with back to the examiner, lifts first one leg and then the other. If when weight is supported by an affected limb, the pelvis on the sound side falls instead of rising, this indicates disturbance of the gluteus medius mechanism, such as deformity of the femoral neck, dislocation of the hip joint, or weakness or paralysis of the gluteus medius muscle. Called also Trendelenburg sign.
treponemal antigen test, see serologic t. for syphilis.
Treponema pallidum complement fixation tests, nontreponemal antigen serologic tests for syphilis using complement fixation rather than flocculation as the indicator reaction. Once widely used to confirm positive results of flocculation procedures, they have now been replaced by treponemal antigen tests.
Treponema pallidum immobilization test, TPI test; the first (1949) treponemal antigen serologic test for syphilis; live Treponema pallidum was mixed with patient serum and complement and examined to see what proportion of treponemes were immobilized by antibodies in the serum.
T3 resin uptake test, triiodothyronine resin uptake t.
TRH test, TRH stimulation test, thyrotropin-releasing hormone t.
trichophytin test, (for Trichophyton infection) a type of intradermal test in which filtrates of the fungus are injected into infected persons; if a reaction similar to the tuberculin reaction is produced, the patient is having a cell-mediated hypersensitivity reaction.
triiodothyronine resin uptake test, T3 resin uptake test; a thyroid function test, measuring how many sites on thyroxine-binding globulin (TBG) are occupied by endogenous triiodothyronine (T3) and how many sites remain available. An excess of radioactive exogenous triiodothyronine is added to the sample, followed by the addition of a resin that also binds T3. A portion of the radioactive T3 binds to sites on TBG not already occupied by endogenous thyroid hormones, and the remainder binds to the resin. The amount of labeled hormones bound to the resin (the triiodothyronine resin uptake) can be subtracted from the total that was added and the remainder is the amount that bound to the unoccupied binding sites on the thyroxine-binding globulin.
triketohydrindene hydrate test, (for free carboxyl or alpha-amino groups) to a solution of aminoacetic acid and water, a solution of sodium acid is added, followed by a solution of triketohydrindene hydrate. The suspected matter is then added and the mixture is boiled. A violet color indicates a free carboxyl and alpha-amino group from a protein, peptone, peptide, or amino acid.
triolein breath test, a breath test for pancreatic function; the fasting patient is administered triolein labeled with either carbon 13 or carbon 14 and levels of labeled carbon dioxide in the exhaled breath are subsequently measured at regular time intervals; low levels of carbon dioxide indicate inadequate pancreatic lipase, such as with a pancreatic disease or cystic fibrosis.
triple test, (for evaluation of breast masses) the use of physical examination, mammography, and fine needle aspiration to evaluate palpable breast masses. Results of each method are given point values of 1 (benign), 2 (suspicious), or 3 (malignant) and the points are totaled; a total score of 4 or less indicates a probably benign lesion, and 6 or more indicates one that is probably malignant.
Trousseau test, (for bile in urine) iodine tincture diluted with 10 parts of alcohol is added to urine in a test tube; a green ring is formed where the liquids touch if bilirubin is present.
TRUE test, thin layer rapid use epicutaneous test; a ready-to-use method for patch testing, consisting of a desiccated mixture of allergen and hydrophilic gel printed on a mylar backing; after application the gel absorbs water from the skin and releases allergen.
tryptophan load test, (for vitamin B6 deficiency) a single large dose of tryptophan is administered orally and a 24-hour urine sample is analyzed for xanthurenic acid, and sometimes also kynurenine, hydroxykynurenine, and kynurenic acid. If vitamin B6 deficiency exists, kynureninase activity will be decreased and these metabolites will accumulate in the urine.
TSH test, TSH stimulation test, thyroid-stimulating hormone t.
tuberculin test, a skin test for tuberculosis using any of various different types of tuberculin and methods of application. See also Heaf t., intradermal tuberculin t., and tine t.
tuberculosis test, a test for the presence of Mycobacterium tuberculosis; see tuberculin t. and niacin t.
tube-slide agglutination test, a type of sperm agglutination test in which sperm and serum are mixed in a tube and then transferred to a slide for examination.
Tuffier test, in aneurysm, when the main artery and vein of a limb are compressed, swelling of the veins of the hand or foot will occur only if the collateral circulation is free.
tuning fork tests, hearing tests using a vibrating tuning fork of known frequency as a source of sound. See Bing t., Rinne t., Schwabach t., and Weber t. (def. 1).
two-stage prothrombin test, two-stage prothrombin time test, (for prothrombin) the quantity of prothrombin can be measured after tissue thromboplastin and excess factor V have converted it to thrombin, by determining the clotting time of a standard fibrinogen solution to which the previously generated thrombin has been added.
two step exercise test, Master “2-step” exercise t.
two-tailed test, a hypothesis test (q.v.) in which the critical region comprises both tails of the distribution of the test statistic and the null hypothesis is tested against a two-sided alternative that includes deviation from the null hypothesis in both directions.
tyrosine test, see specific tests, including Hoffmann t., Mörner t. (def. 1), Piria t., Udránszky t. (def. 2), and Wurster t. (def. 2).
Tyson test, (for bile acids in urine) 180 to 240 mL of urine are evaporated to dryness on the water bath. The residue is extracted with absolute alcohol, and to the extract 12 to 14 volumes of ether are added. The bile acids are precipitated, then are filtered off, dissolved in water, and the aqueous solution decolorized with animal charcoal.
Tzanck test, examination of tissue from the floor of a lesion, in vesicular or bullous diseases, in order to discover the type of cell present for better diagnosis of the disease. Multinucleated giant cells are pathognomonic of varicella, herpes simplex, herpes zoster, and pemphigus.
Udránszky test, (for bile acids) take 1 mL of a solution of the suspected substance, add a drop of 0.1 per cent solution of furfurol in water, underlay with strong sulfuric acid, and cool; if bile is present, a bluish-red color is formed.(for tyrosine) take 1 mL of the suspected substance in solution, add a drop of 0.5 per cent aqueous solution of furfurol, and underlay with 1 mL of concentrated sulfuric acid; a pink color shows the presence of tyrosine.
Ulrich test, (for albumin) the reagent consists of saturated solution of sodium chloride, 98 mL; glacial acetic acid, 2 mL. It must be perfectly clear. Boil a few mL of this fluid in a test tube, and immediately overlay with the urine. Albumin and globulin give a white ring at the zone of contact.
Ultzmann test, (for bile pigments) to 10 mL of the urine to be tested add 3 or 4 mL of a 1:3 solution of potassium hydroxide, and an excess of hydrochloric acid; bile pigments will cause an emerald-green coloration.
unheated serum reagin test, USR test; a modification of the VDRL test using unheated serum, used primarily for screening.
uracil test, see Wheeler and Johnson t.
urea test, see specific tests, including diacetyl t., Schroeder t., and urease t.(def. 1). See also urea, methods for, under method.
urea breath test, a breath test for the presence of Helicobacter pylori in the stomach: the patient is given an oral dose of urea labeled with carbon 13 (heavy carbon) or carbon 14 (radioactive carbon). At fixed time intervals the breath is analyzed for presence of labeled carbon dioxide. Excessive levels of carbon dioxide indicate presence of H. pylori, since it is accompanied by bacterial urease that converts the urea to ammonia and carbon dioxide.
urease test, a test for urea based on the conversion of urea into ammonium carbonate by the urease of soybean.(for the production of urease by bacteria) urease test broth (see under culture medium) is prepared in slants. After inoculation of the surface and incubation, urease-positive cultures produce an alkaline reaction (red color) in the medium. Proteus cultures show an early urease-positive reaction; other bacteria (such as Salmonella and Shigella) usually have a delayed response.
Urecholine supersensitivity test, (for neurogenic bladder) 2.5 mg of Urecholine (bethanechol) is administered subcutaneously; the bladder is neurogenic if it exhibits a rise in intravesical pressure more than 15 cm greater than that of a control.
uric acid test, see specific tests, including Weidel t. (def. 1). See also uric acid, methods for, under method.
urine concentration test, under a controlled diet the specific gravity of the urine should reach 1.18 or more at certain times.
urochromogen test, see Weisz t.
USR test, unheated serum reagin t.
Valsalva test, Valsalva maneuver (def. 2).
Van Slyke test, (for amide nitrogen) nitrous acid acting on amide nitrogen sets free nitrogen gas, which is collected and its volume determined.(for urea) treat the sample with urease, pass the ammonia so formed into N/50 normal acid, and titrate the excess of acid.
VDRL test, the standard nontreponemal antigen serologic test for syphilis, a flocculation test on a slide using heat-inactivated serum and VDRL antigen. Positive tests are seen in about 70 per cent of cases in primary syphilis, 100 per cent in secondary syphilis, and 70 per cent in tertiary syphilis. There is a 20 to 40 per cent false positive rate.
ventilation test, measurement of the quantity of air exhaled by a person during a period of exercise. See also pulmonary function t.
Vitali test, (for alkaloids) evaporate with fuming nitric acid and add a drop of potassium hydroxide; color reactions will occur. For atropine the color is violet, turning to red.(for alkaloids) add sulfuric acid, potassium chlorate, and an alkaline sulfide; various color reactions will follow.(for bile pigments) add a few drops of potassium nitrate in solution and dilute sulfuric acid. The color reactions are green, followed by blue or red and yellow.(for bile pigments) add quinine bisulfate in solution and follow with diluted ammonia solution, sulfuric acid, a crystal of sugar, and alcohol; a violet color results.(for thymol) distill, and pass the vapor through a mixture of chloroform and potassium hydroxide solution; a red color results.(for pus in the urine) the urine is acidified with acetic acid and filtered. On the filter paper thus obtained a small quantity of guaiacum is dropped. The paper will turn a dark blue if pus is present.
vitamin test, see specific tests, including dark-adaptation t., deoxyuridine suppression t., Friderichsen t., histidine loading t., and Schilling t.
Vogel and Lee test, (for mercury) add 3 per cent of hydrochloric acid and concentrate the urine to one fifth its original volume. Add a piece of clean copper wire. A silvery film indicates mercury. To confirm, place the wire in a tube with a plug of gold foil and distill the mercury over onto the gold. Sublime a crystal of iodine onto the mercury and form the red iodide of mercury.
Voges-Proskauer test, (for differentiation of Enterobacteriaceae) a test for the production of acetylmethylcarbinol from glucose in bacterial cultures. An appropriate culture is treated with a solution of potassium hydroxide and creatine. Development of a red color indicates a positive reaction. Enterobacter, Klebsiella, Pantoea, and Serratia are V-P positive; Erwinia, Pectobacterium, and Yersinia are variable; Escherichia and other genera of Enterobacteriaceae are V-P negative.
von Maschke test, (for creatinine) to the suspected solution add a few drops of Fehling solution, after mixing with a cold solution of sodium carbonate; an amorphous, flocculent precipitate proves the presence of creatinine.
von Pirquet test, Pirquet t.
von Zeynek and Mencki test, (for blood) precipitate the urine with acetone, extract the precipitate with acidified acetone, and examine the colored extract under the microscope for small hemin crystals.
Waaler-Rose test, Rose-Waaler t.
Wada test, (for cerebral dominance of language function) amobarbital is injected into an internal carotid artery to produce transient hemiparesis of the contralateral limbs. Injection into the artery of the hemisphere dominant for language produces a transient aphasia, into that of the nondominant hemisphere does not interfere with language function.
Wagner test, (for occult blood), see benzidine t.
walking test, an exercise test used to assess exercise tolerance in very disabled patients by measuring the distance walked in a set time interval.
Wassermann test, the original (1906) nontreponemal antigen test for syphilis; see serologic t. for syphilis.
water deprivation test, a test of the body's ability to concentrate urine when plasma osmolality is artificially increased: without fasting, the patient is deprived of water for at least eight hours. Patient weight and measurements of plasma and urine osmolalities are obtained before the test and each hour after the four-hour point. In a normal individual, the osmolality of the urine should increase to two to four times that of the plasma with eight hours of water deprivation. After eight hours, vasopressin is administered and the patient is allowed to drink as usual; in normal persons this should increase the urine osmolality no more than 9 per cent in the first hour; in those with diabetes insipidus and other abnormalities the osmolality may increase between 10 and 50 per cent.
water provocative test, drinking t.
Watson-Schwartz test, a simple qualitative procedure for differentiating porphobilinogen from urobilinogen and other Ehrlich reactors, based on the insolubility of porphobilinogen aldehyde in chloroform and butanol; it is useful in diagnosis of acute porphyria.
Weber test, (for hearing) the stem of a vibrating tuning fork is placed on the vertex or midline of the forehead; if the sound is heard best in the affected ear, conductive hearing loss is probable; if sound is heard best in the normal ear, there is probably sensorineural hearing loss. (F. E. Weber.)
(for indican) boil 30 mL of urine with an equal volume of hydrochloric acid containing a little nitric acid; cool it, and shake with ether; if indican is present, the ether will become red or violet and the froth will be blue. (E. H. Weber.)(for blood) mix the sample with 30 per cent acetic acid and extract with ether; to the ether extract add an alcoholic solution of guaiac and hydrogen peroxide. A blue color indicates blood. (E. H. Weber.)
Weidel test, (for uric acid) the substance tested is treated with nitric acid, evaporated, and moistened with diluted ammonia solution; if uric acid is present, murexide will be formed, and a purple color is produced. Called also murexide t.(for xanthine) warm with freshly prepared chlorine water containing a trace of nitric acid until gas ceases to be produced; contact with gaseous ammonia develops a pink or purple color.(for xanthine bodies) dissolve in warm chlorine water, evaporate, and treat with diluted ammonia solution; a pink or purple color will form, changing to violet on the addition of sodium or potassium hydroxide solution.
Weil-Felix test, (for typhus and certain other rickettsial diseases) the blood serum of a patient with suspected rickettsial disease is tested against certain strains of Proteus vulgaris (OX-2, OX-19, OX-K).The agglutination reactions, based on antigens common to both organisms, determine the presence and type of rickettsial infection.
Weisz test, Weisz permanganate test, (for urochromogen) to 2 mL of the urine add 4 mL of distilled water and 3 drops of a 1:1000 solution of potassium permanganate; a canary yellow color indicates urochromogen.
Welland test, bar-reading t.
Wenzell test, (for strychnine) treat the suspected material with a solution of 1 part potassium permanganate in 2000 parts of sulfuric acid; even a small amount of strychnine will cause color reactions.
Wernicke test, see hemiopic pupillary reaction, under reaction.
Western blot test, Western blot.
Wetzel test, (for carbon monoxide in blood) to the blood to be examined add 4 volumes of water and treat with 3 volumes of a 1 per cent tannin solution. If CO is present, the blood becomes carmine red; normal blood slowly assumes a grayish hue.
Weyl test, (for creatinine) to the suspected solution add a little of a dilute solution of sodium nitroprusside, and then carefully put in a few drops of a weak solution of sodium hydroxide; a ruby red color results, changing to blue on warming with acetic acid.(for nitric acid in the urine) distill 200 mL of urine with 0.2 part of sulfuric or hydrochloric acid, receiving the distillate in a potassium hydroxide solution. If m-phenyldiamine is added, a yellow color will form; if there is added pyrogallic acid in aqueous solution with a little sulfuric acid, the color will be brown; but sulfanilic acid in solution, followed in ten minutes by naphthylamine hydrochlorate, produces a red tint.
Wheeler and Johnson test, (for uracil and cytosine) to the unknown solution, gradually add bromine water until the color is permanent; then add an excess of barium hydroxide. A purple color indicates presence of either uracil or cytosine.
Whitaker test, (for resistance of ureters) a pressure-flow study measuring resistance of the ureters to a given flow rate of urine by antegrade pyelography of the renal pelvis and a catheter in the bladder.
Widal test, Widal serum test, (for typhoid and paratyphoid fevers) a test of serum of patients with suspected Salmonella infection, for the presence of agglutinins to O antigens and H antigens of the Salmonella enterica serovars causing typhoid and paratyphoid fevers.
Wilcoxon rank sum test, rank sum t.
Wilcoxon signed rank test, signed rank t.
Wishart test, (for acetonemia) a few drops of plasma are placed in a small test tube. Enough dry powdered ammonium sulfate is added to supersaturate, so that at the end of the test there will still be some of the solid sulfate in the bottom of the tube. A couple of drops of a fresh solution of sodium nitroprusside are next added and shaken, and finally 1 or 2 drops of diluted ammonia solution. On shaking, a purple color develops, a little more slowly than in the case of urine. The intensity of the color indicates the degree of acetonemia.
Woodbury test, (for alcohol in the urine) to 2 mL of urine 1 mL of sulfuric acid is added, and a crystal of potassium dichromate; a green color will form.
Wormley test, treat the suspected solution with an alcoholic solution of picric acid; if a yellow precipitate forms, the result is positive.treat the suspected solution with a solution of 1 part iodine and 2 parts potassium iodide in 60 parts of water; if a colored precipitate forms, the result is positive.
Wurster test, (for hydrogen peroxide) test paper is saturated with the solution of tetramethylparaphenylenediamine; hydrogen peroxide turns it to a blue-violet color.(for tyrosine) the suspected material is dissolved in boiling water and a little quinone; formation of a ruby-red color that changes slowly to brown is a positive result.
xanthine test, see specific tests, including Hoppe-Seyler t. (def. 2) and Weidel t. (defs. 2, 3).
d-xylose absorption test, (for malabsorption syndromes)d-xylose dissolved in water is given orally to a fasting adult, followed immediately by additional water, and the amount excreted in the urine during a 5-hour period is determined. Since poor renal function may also result in low xylose absorption, blood levels are also determined at two hours. Less than normal excretion of xylose suggests intestinal malabsorption. Called also d-xylose tolerance t.
d-xylose breath test, a breath test for bacterial overgrowth in the intestine; the fasting patient is administered a dose of d-xylose labeled with carbon 14 and the amount of radiolabeled carbon dioxide in the breath is measured at regular time intervals. Excessive levels of carbon dioxide mean that there are high levels of anaerobic bacteria in the intestines breaking down the xylose.
d-xylose tolerance test, d-xylose absorption t.
Young test, (for cataract) on a disk with a varied number of pinholes in different portions, the patient's ability to recognize the number of holes is a test of the integrity of macular function.
z test, a statistical test using normalized data (z values) to compare differences in proportions between sets of data or between individual members of different sets of data.
Zaleski test, (for carbon monoxide in blood) to 2 mL of blood add an equal volume of water and 3 drops of a one-third saturated solution of cupric sulfate: if carbon monoxide is present, the precipitate is brick-red; otherwise it is greenish brown.
Zeisel test, (for colchicine) the substance being analyzed is dissolved in hydrochloric acid, boiled with ferric chloride, and shaken with chloroform; if colchicine is present, a brown or dark-red layer will form at the bottom.