Medical Dictionary

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dosimetry (do-sim′e-tre)
Measurement of radiation exposure, especially x-rays or gamma rays; calculation of radiation dose from internally administered radionuclides. thermoluminescence d. the calculation of a radiation dose by measuring the light output after heating a special absorbent material ( e.g., lithium fluoride) placed in the radiation beam; the light output is proportional to the amount of radiation exposure. x-ray d. SYN: roentgenometry.

dot (dot)
A small spot. Gunn dots minute, highly glistening, white or yellowish specks usually seen in the posterior part of the fundus; nonpathologic. Horner-Trantas dots evanescent white cellular infiltrates occurring in the bulbar form of vernal keratoconjunctivitis. Maurer dots finely granular precipitates or irregular cytoplasmic particles that usually occur diffusely in red blood cells infected with the trophozoites of Plasmodium falciparum, occasionally those of P. malariae; rarely observed in P. falciparum blood smears because its trophozoites seldom are seen in peripheral blood. SYN: Maurer clefts. Mittendorf d. a small d. visible on the posterior aspect of the lens capsule on ophthalmologic examination that represents a remnant of the primitive hyaloid vascular system. Schüffner dots fine, round, uniform red or red-yellow dots (as colored with Romanovsky stains) characteristically observed in erythrocytes infected with Plasmodium vivax and P. ovale, but not ordinarily found in P. malariae and P. falciparum infections. SYN: Schüffner granules. Trantas dots pale, grayish red, uneven nodules of gelatinous aspect at the limbal conjunctiva in vernal conjunctivitis. Ziemann dots fine dots seen in erythrocytes in malariae malaria. SYN: Ziemann stippling.

dotage (do′tij)
The deterioration of previously intact mental powers, common in old age.

doublet (dub′let)
1. A combination of two lenses designed to correct the chromatic and spherical aberration. 2. SYN: dipole. 3. Any sequence of two nucleotides in a polynucleotide strand. 4. A closely spaced pair of peaks or lines in a spectrum. Wollaston d. a combination of two planoconvex lenses in the eyepiece of a microscope designed to correct the chromatic aberration.

douche (doosh)
1. A current of water, gas, or vapor directed against a surface or projected into a cavity. 2. An instrument for giving a d.. 3. To apply a d.. [Fr. fr. doucher, to pour]

Douglas
Claude G., English physiologist, 1882–1963. See D. bag.

Douglas
Beverly, U.S. surgeon, 1891–1975.

Douglas
James, Scottish anatomist in London, 1675–1742. See D. abscess, D. cul-de-sac, D. fold, D. line, D. pouch, cavum douglasi.

Douglas
John C., Irish obstetrician, 1777–1850. See D. mechanism.

dovetail (duv′tal)
A widened portion of a cavity preparation usually established to increase the retention and resistance form.

dowel (dow′l)
1. A cast gold or preformed metal pin placed into a root canal for the purpose of providing retention for a crown. 2. A preformed metal pin placed in a copper-plated die to provide a die stem. 3. A pin or rod that aligns or joins two structures by fitting into holes in both of them; dowels of various materials are used in orthopaedic surgery and dentistry. 4. SYN: d. graft.

Down
John Langdon H., English physician, 1828–1896. See D. syndrome.

Downey
Hal, U.S. hematologist, 1877–1959. See D. cell.

downgrowth (doun-groth)
Something that grows downward; the process of growing in a downward direction. epithelial d. the invasion of surface epithelium into the interior of the eye as a consequence of a penetrating ocular wound.

down-regulation
Development of a refractory or tolerant state consequent upon repeated administration of a pharmacologically or physiologically active substance; often accompanied by an initial decrease in affinity of receptors for the agent and a subsequent diminution in the number of receptors.

Downs
William B., U.S. orthodontist, 1899–1966. See D. analysis.

Dox
Arthur W., U.S. chemist, *1882. See Czapek-D. medium.

doxacurium chloride (doks′a-koo′re-um)
A nondepolarizing neuromuscular blocking drug similar to pancuronium but without cardiovascular side effects.

doxapram hydrochloride (doks′a-pram)
A central nervous system stimulant, advocated but infrequently used as a respiratory stimulant in anesthesia.

doxazocin (doks′a-zo-sin)
An antihypertensive agent that selectively blocks the α1 (postjunctional) subtype of α-adrenergic receptors; resembles prazocin in pharmacologic actions. Prevents the blood pressure elevating effects of norepinephrine, phenylephrine, and other agonists at vascular α1-receptors.

doxepin hydrochloride (dok′se-pin)
An antidepressant agent.

doxophylline (doks′o-fil′in)
A theophyllinelike drug used, though rarely in the U.S., as a bronchodilator in asthma and chronic obstructive pulmonary disease.

doxorubicin (dok′so-roo′bi-sin)
An antineoplastic antibiotic isolated from Streptomyces peucetius; also used in cytogenetics to produce Q-type chromosome bands. SYN: adriamycin.

doxycycline (dok-se-si′klen)
A broad-spectrum antibiotic.

doxylamine succinate (dok-sil′a-men)
An antihistaminic. SYN: mereprine.

Doyère
Louis, French physiologist, 1811–1863. See D. eminence.

Doyle
J.B., U.S. gynecologist, *1907. See D. operation.

Doyne
Robert Walter, English ophthalmologist, 1857–1916. See D. honeycomb choroidopathy.

D.P.
Abbreviation for Doctor of Podiatry.

D.P.H.
Abbreviation for Department of Public Health; Doctor of Public Health; Diploma of Public Health.

D.P.M.
Abbreviation for Doctor of Podiatric Medicine.

DPT
Abbreviation for diphtheria-pertussis-tetanus (vaccine). See diphtheria toxoid, tetanus toxoid, and pertussis vaccine.

DR
Abbreviation for digital radiography.

Dr.
Abbreviation for doctor.

dr
Abbreviation for dram.

drachm (dram)
SYN: dram. [G. drachme, an ancient Greek weight, equivalent to about 60 gr]

dracunculiasis, dracunculosis (dra-kung-ku-li′a-sis, -ku-lo′sis)
Infection with Dracunculus medinensis.

Dracunculus (dra-kung′ku-lus)
A genus of nematodes (superfamily Dracunculoidea) that have some resemblances to true filarial worms; however, adults are larger (females being as long as 1 m), and the intermediate host is a freshwater crustacean rather than an insect. [L. dim. of draco, serpent] D. lova old incorrect term for Loa loa. D. medinensis a species of skin-infecting, yard-long nematodes, formerly incorrectly classed as Filaria; adult worms live anywhere in the body of humans and various semi-aquatic mammals; the females migrate along fascial planes to subcutaneous tissues, where troublesome chronic ulcers are formed in the skin; when the host enters water, larvae are discharged from the ulcers, from which the head of the female worm protrudes; these larvae, if ingested by Cyclops species, develop in the intermediate host to the infective stage; humans and various animals contract the infection from accidental ingestion of infected Cyclops in drinking water. Popularly known as guinea, Medina, serpent, or dragon worm, and frequently thought to be the “fiery serpent” that plagued the Israelites. [L. of Medina] D. oculi old incorrect term for Loa loa. D. persarum old term for D. medinensis. [L. of the Persians]

draft
1. A current of air in a confined space. 2. A quantity of liquid medicine ordered as a single dose. SYN: draught.

drag
1. The lower or cast side of a denture flask. 2. Any tendency for one moving thing to pull something else along with it. solvent d. the influence exerted by a flow of solvent through a membrane on the simultaneous movement of a solute through the membrane.

dragée (dra-zha′)
A sugar-coated pill or capsule. [Fr.]

Dragendorff
Georg J.N., German physician and pharmaceutical chemist, 1836–1898. See D. test.

Drager
Glenn A., U.S. neurologist, *1917. See Shy-D. syndrome.

Dräger
Heinrich, German manufacturer of industrial and diving respiratory apparatus and anesthesia machines, 1847–1917. See D. respirometer.

drain (dran)
1. To remove fluid from a cavity as it forms, e.g., to d. an abscess. 2. A device, usually in the shape of a tube or wick, for removing fluid as it collects in a cavity, especially a wound cavity. [A. S. drehnian, to draw off] cigarette d. a wick of gauze wrapped in a thin, soft rubberlike material, providing capillary drainage. Mikulicz d. a d. made of several strings of gauze held together by a single layer of gauze. Penrose d. a soft, tubular, rubberlike d.. stab d. a d. passed into a cavity through a puncture made at a dependent part away from the wound of operation, designed to prevent infection of the wound. sump d. a d. consisting of an outer tube vented to the outside with a smaller tube within it which is attached to a suction pump; both have multiple perforations that allow fluid and air to be carried away through the suction tube.

drainage (dran′ij)
Continuous withdrawal of fluids from a wound or other cavity. capillary d. d. by means of a wick of gauze or other material. closed d. d. of a body cavity via a water- or air-tight system. Cf.:sump drain. dependent d. d. from the lowest part and into a receptacle at a level lower than the structure being drained. SYN: downward d.. downward d. SYN: dependent d.. infusion-aspiration d. a type of d. in which antibiotics are continuously infused into a cavity at the same time fluid is being drained (aspirated) from the cavity. open d. d. allowing air to enter. postural d. d. used in bronchiectasis and lung abscess. The patient's body is positioned so that the trachea is inclined downward and below the affected chest area. suction d. closed d. of a cavity, with a suction apparatus attached to the d. tube. through d. d. obtained by the passage of a perforated tube, open at both extremities, through a cavity; in addition, the cavity can be washed out by a solution passed through the tube. tidal d. d. of the urinary bladder by means of an intermittent filling and emptying apparatus. Wangensteen d. continuous d. by suction through an indwelling gastric or duodenal tube.

dram (dr)
A unit of weight: 1/8 oz.; 60 gr, apothecaries' weight; 1/16 oz., avoirdupois weight. SYN: drachm. [see drachm]

drape (drap)
1. To cover parts of the body other than those to be examined or operated upon. 2. The cloth or materials used for such cover. [M.E., fr. L.L. drappus, cloth]

Draper
John William, English chemist, 1811–1882. See D. law.

draught (draft)
SYN: draft.

draw-sheet (draw′shet)
A narrow sheet placed crosswise on the bed under the patient to assist in moving the patient or in changing soiled bed coverings.

dream (drem)
Mental activity during sleep in which events, thought, emotions, and images are experienced as real. anxiety d. a d. (or nightmare) in which morbid fear and anxiety form an important part. wet d. a true physiologic orgasm during sleep including, in males, a nocturnal seminal emission usually accompanying a d. with sexual content.

dream-work
In psychoanalysis, the process by which the change from latent to manifest content of a dream is effected.

Drechslera (dresh′ler-a)
A saprobic genus of fungi, frequently recovered in the clinical laboratory, characterized by conidia attached to a zigzagged conidiophore. Most species in this genus that cause phaeohyphomycosis in humans, cats, and horses have been transferred to the genera Bipolaris or Exserohilum.

Dreifuss
Fritz E., *1926. See Emery-D. muscular dystrophy.

drepanidium (drep-a-nid′e-um)
A young sickle-shaped or crescentic form of a gregarine. [G. drepane, a sickle]

drepanocyte (drep′a-no-sit)
SYN: sickle cell. [G. drepane, sickle, + kytos, a hollow (cell)]

drepanocytic (drep′a-no-sit′ik)
Relating to or resembling a sickle cell.

dresser (dres′er)
In Great Britain, a surgical assistant whose primary duty is bandaging and dressing wounds.

dressing (dres′ing)
The material applied, or the application itself of material, to a wound for protection, absorbance, drainage, etc. adhesive absorbent d. a sterile individual d. consisting of a plain absorbent compress affixed to a film of fabric coated with a pressure-sensitive adhesive. antiseptic d. a sterile d. of gauze impregnated with an antiseptic. bolus d. SYN: tie-over d.. dry d. dry gauze or other material applied to a wound. fixed d. a d. stiffened with a substance that produces immobilization when it dries. Lister d. the first type of antiseptic d., one of gauze impregnated with carbolic acid. occlusive d. a d. that hermetically seals a wound. pressure d. a d. by which pressure is exerted on the area covered to prevent the collection of fluids in the underlying tissues; most commonly used after skin grafting and in the treatment of burns. tie-over d. a d. placed over a skin graft or other sutured wound and tied on by the sutures which have been left of sufficient length for that purpose. SYN: bolus d.. water d. an application of gauze or other material that is kept wet with sterilized water or saline solution. wet-to-dry d. a d. that is applied moist with saline and allowed to dry before it is removed.

Dressler
William, U.S. physician, 1890–1969. See D. beat, D. syndrome.

Dreyer
Georges, English pathologist, 1873–1934. See D. formula.

DRG
Abbreviation for diagnosis-related group.

dribble (dri′bl)
1. To drool, slaver, drivel. 2. To fall in drops, as the urine from a distended bladder.

drift
1. A gradual movement, as from an original position. 2. A gradual change in the value of a random variable over time as a result of various factors, some random and some systematic effects of trend, manipulation, etc. antigenic d. the process of “evolutionary” changes in molecular structure of DNA/RNA in microorganisms during their passage from one host to another; it may be due to recombination, deletion, or insertion of genes, point mutations or combinations of these events; it leads to alteration (usually slow and progressive) in the antigenic composition, and therefore in the immunologic responses of individuals and populations to exposure to the microorganism concerned; common with influenzavirus. genetic d. a change in the frequencies of genetic traits or allele frequencies over generations. pure random d. that which has random components only with an average value of zero and no systematic effects. Brownian movement in a still container shows pure random d. but in the Mississippi shows a steady downstream tendency.

drifting
Random movement of a tooth to a position of greater stability.

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