Medical Dictionary

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δ, capital: Δ

The fourth letter of the Greek alphabet — symbol Δ or δ
Any of various things felt to resemble a capital Δ; especially : the triangular terminus of a pattern in a fingerprint formed either by bifurcation of a ridge or by divergence of two ridges that are parallel beyond it.
Of or relating to one of four or more closely related chemical substances,e.g., the delta chain of fetal hemoglobin, δ-yohimbine — used somewhat arbitrarily to specify ordinal relationship or a particular physical form and especially one that is allotropic, isomeric, or stereoisomeric (as in δ-benzene hexachloride).
In chemistry it denotes a double bond, usually with a superscript to indicate position in a chain (Δ5).
Application of heat in a reaction (A B).
Absence of heat treatment.
Distance between two atoms in a molecule.
Position of a substituent located on the fourth atom from the carboxyl or other primary functional group (δ).
Change (Δ).
Thickness (δ).
Chemical shift in NMR (δ).
Fourth in position in the structure of an organic molecule from a particular group or atom.
Having a structure characterized by such a position, e.g., δ-hydroxy acids, δ-lactones.

δ-9-tetrahydrocannabinol or Δ9-tetrahydrocannabinol or delta-9-tetrahydrocannabinol
Abbr. THC: Either of two physiologically active isomers C₂₁H₃₀O₂ that occur naturally in hemp plant resin or are synthetically prepared:

One that is the chief intoxicant in marijuana and is used medicinally—called also delta-9-tetrahydrocannabinol, delta-9-THC; see dronabinol
One that is present in marijuana only in minute quantities

δ-aminobutyric acid amino transferase
An enzyme catalyzing the reversible transfer of an amino group from δ-aminobutyric acid to 2-oxoglutarate, thus forming a l-glutamic acid and succinate semialdehyde. An important step in the catabolism of δ-aminobutyric acid.

δ-aminolevulinate dehydratase (a-me′no-lev-u-lin′at)
SYN: porphobilinogen synthase.

δ-aminolevulinic acid (ALA) (a-me′no-lev-u-lin′ik)
An acid formed by δ-aminolevulinate synthase from glycine and succinyl-coenzyme A; a precursor of porphobilinogen, hence an important intermediate in the biosynthesis of heme. ALA levels are elevated in cases of lead poisoning. δ-aminolevulinic acid synthase an enzyme that catalyzes the reaction of succinyl-CoA with glycine to form δ-aminolevulinic acid, coenzyme A, and CO2. The committed step in porphyrin biosynthesis.

Δ check
SYN: delta check.

d-amphetamine phosphate
SYN: dextroamphetamine phosphate.

d-amphetamine sulfate
SYN: dextroamphetamine sulfate.

D
1. Symbol for the vitamin D potency of cod liver oil, multiples of which (5D, 100D, etc.) are used to designate the vitamin D potency of irradiated ergosterol (viosterol) or other substances; for deuterium; for dihydrouridine in nucleic acids; for diffusing capacity; for aspartic acid; dihydrouridine; diffusion coefficient (in italics). 2. In optics, abbreviation for diopter; for dexter (right). 3. In electrodiagnosis, abbreviation for duration, the current flowing and the circuit being closed. 4. In dental formulas, abbreviation for deciduous (2) . 5. As a subscript, refers to dead space. See physiologic dead space. 6. D line in Na emission spectra.

2,4-D
Abbreviation for (2,4-dichlorophenoxy) acetic acid.

d
Symbol for deci-; abbreviation for dexter [L], right; diameter; day.

d-
Prefix indicating a chemical compound to be dextrorotatory; should be avoided when (+) or (−) could be used. Cf.:l-.

d-
Prefix indicating that a chemical compound is sterically related to d-glyceraldehyde, the basis of stereochemical nomenclature. Cf.:l-.

d(-)-α-aminobenzylpenicillin (a-me-no-ben′zil-pen-i-sil′in)
SYN: ampicillin.

-d
Suffix indicating the presence of deuterium in a compound in concentrations above normal, thus labeling the compound; subscripts (d2, d3, etc.) indicate the number of such atoms so fortified.

DA
Abbreviation for developmental age (2) .

Da
Symbol for dalton.

dA, dAdo
Abbreviation for deoxyadenosine.

da
Symbol for deca-.

Daae
Anders, Norwegian physician, 1838–1910. See D. disease.

DAB
Abbreviation for 3′3-diaminobenzidine HCl; in the immunoperoxidase technique, used to produce a colored complex at the site of peroxidase activity.

dacarbazine (DTIC) (da-kar′ba-zen)
An antineoplastic agent used in the treatment of malignant melanoma and sarcoma.

dacry-
See dacryo-.

dacryadenitis (dak′re-ad-e-ni′tis)
SYN: dacryoadenitis.

dacryo-, dacry-
Tears; lacrimal sac or duct. [G. dakryon, tear]

dacryoadenitis (dak-re-o-ad-e-ni′tis)
Inflammation of the lacrimal gland. SYN: dacryadenitis. [dacryo- + G. aden, gland, + -itis, inflammation]

dacryoblennorrhea (dak-re-o-blen-o-re′a)
A chronic discharge of mucus from a lacrimal sac. [dacryo- + G. blenna, mucus, + rhoia, flow]

dacryocele (dak′re-o-sel)
SYN: dacryocystocele.

dacryocyst (dak′re-o-sist)
SYN: lacrimal sac. [dacryo- + G. kystis, sac]

dacryocystalgia (dak′re-o-sis-tal′je-a)
Pain in the lacrimal sac. [dacryocyst + G. algos, pain]

dacryocystectomy (dak′re-o-sis-tek′to-me)
Surgical removal of the lacrimal sac. [dacryocyst + G. ektome, excision]

dacryocystitis (dak′re-o-sis-ti′tis)
Inflammation of the lacrimal sac. [dacryocyst + G. -itis, inflammation]

dacryocystocele (dak′re-o-sis′to-sel)
Enlargement of the lacrimal sac with fluid. SYN: dacryocele. [dacryocyst + G. kele, hernia]

dacryocystogram (dak′re-o-sis′to-gram)
A radiograph of the lacrimal apparatus obtained after injection of contrast material for the purpose of determining the presence of and localizing a site of obstruction; this procedure has been largely replaced by the CT and MRI. [dacryocyst + G. gramma, a writing]

dacryocystorhinostomy (dak′re-o-sis′to-ri-nos′to-me)
An operation providing an anastomosis between the lacrimal sac and the nasal mucosa through an opening in the lacrimal bone. [dacryocyst + G. rhis (rhin-), nose, + stoma, mouth]

dacryocystotomy (dak′re-o-sis-tot′o-me)
Incision of the lacrimal sac. [dacryocyst + G. tome, incision]

dacryohemorrhea (dak′re-o-hem-o-re′a)
Bloody tears. [dacryo- + G. haima, blood, + rhoia, flow]

dacryolith (dak′re-o-lith)
A concretion in the lacrimal apparatus. SYN: lacrimal calculus, ophthalmolith, tear stone. [dacryo- + G. lithos, stone] Desmarres dacryoliths SYN: Nocardia dacryoliths. Nocardia dacryoliths white pseudoconcretions, composed of masses of Nocardia species found in the lacrimal canaliculi. SYN: Desmarres dacryoliths.

dacryolithiasis (dak′re-o-li-thi′a-sis)
The formation and presence of dacryoliths.

dacryon (dak′re-on)
The point of junction of the frontomaxillary and lacrimomaxillary sutures on the medial wall of the orbit.See figure under craniometric points, under point. [G. a tear]

dacryops (dak′re-ops)
1. Excess of tears in the eye. 2. A cyst of a duct of the lacrimal gland. [dacryo- + G. ops, eye]

dacryopyorrhea (dak′re-o-pi-o-re′a)
The discharge of tears containing leukocytes. [dacryo- + G. pyon, pus, + rhoia, flow]

dacryorrhea (dak′re-o-re′a)
An excessive secretion of tears. [dacryo- + G. rhoia, flow]

dacryostenosis (dak′re-o-ste-no′sis)
Stricture of the lacrimal duct. [dacryo- + G. stenosis, narrowing]

dactinomycin (dak′ti-no-mi′sin)
Produced by several species of Streptomyces ( e.g., S. parvulus); an antineoplastic antibiotic used especially for Ewing sarcoma, rhabdomyosarcoma, and Wilms tumor in children and for trophoblastic disease in women. SEE ALSO: actinomycin. SYN: actinomycin D.

dactyl (dak′til)
SYN: digit. [G. daktylos]

dactyl-
See dactylo-.

dactylalgia (dak-ti-lal′je-a)
Pain in the fingers. SYN: dactylodynia. [dactyl- + G. algos, pain]

Dactylaria (dak-ti-la′re-a)
A genus of dematiaceous soil-dwelling fungi. D. gallopava is a causative agent of phaeohyphomycosis in chickens and turkeys. [G. daktylos, finger]

dactylitis (dak-ti-li′tis)
Inflammation of one or more fingers. blistering distal d. infection of the volar fat pad of the distal phalanx of the finger by group A β-hemolytic streptococci. sickle cell d. SYN: hand-and-foot syndrome.

dactylo-, dactyl-
The fingers and (less often) toes. See entries under digit. [G. daktylos, finger]

dactylocampsis (dak′ti-lo-kamp′sis)
Permanent flexion of the fingers. [dactylo- + G. kampsis, bending]

dactylocampsodynia (dak′ti-lo-kamp′so-din′e-a)
Painful contraction of one or more fingers. [dactylo- + G. kampsis, a bending, + odyne, pain]

dactylodynia (dak′ti-lo-din′e-a)
SYN: dactylalgia.

dactylogryposis (dak′ti-lo-gri-po′sis)
Contraction of the fingers. [dactylo- + G. gryposis, a crooking]

dactylology (dak′ti-lol′o-je)
The use of the finger alphabet in communicating. SYN: cheirology, chirology. [dactylo- + G. logos, word]

dactylomegaly (dak′til-o-meg′a-le)
SYN: megadactyly. [dactylo- + G. megas, large]

dactyloscopy (dak-ti-los′ko-pe)
An examination of the markings in prints made from the fingertips; employed as a method of personal identification. See Galton system of classification of fingerprints, under fingerprint. [dactylo- + G. skopeo, to examine]

dactylospasm (dak′ti-lo-spazm)
Spasmodic contraction of the fingers or toes.

dactylus, pl .dactyli (dak′ti-lus, -li)
SYN: digit. [G. daktylos]

dacuronium (dak-u-ro′ne-um)
A nondepolarizing steroid neuromuscular blocking agent with more rapid onset and shorter duration of action than pancuronium.

Da Fano
Corrado D., Italian-American anatomist, 1879–1927. See D. stain.

DAG
Abbreviation for diacylglycerol.

dagga (dag′a)
Leaves of Leonotis leonurus, a plant found in South Africa, where it is smoked like tobacco with mild sedative effect; a term mistakenly applied to Indian hemp, Cannabis sativa. [aborigines' term]

Dagnini
Giuseppe, Italian physician, 1866–1928. See Aschner-D. reflex.

DAH
Abbreviation for disordered action of heart.

dahlia (dal′yah)
A violet dye, methyl-triethyl-amino-triphenyl-carbinol chloride. Also called Hoffman violet.

dahlin
SYN: inulin. [fr. dahlia, after A. Dahl, Swedish botanist, 1751–1789]

dahllite (dah′lit)
A naturally occurring calcium phosphate, similar in structure to the mineral portions of bones and teeth. SYN: podolite.

daisy (da′ze)
Colloquial term descriptive of the segmented forms (merozoites) of the mature schizont of Plasmodium malariae.

Dakin
Henry, U.S. chemist, 1880–1952. See D. fluid, D. solution, D.-Carrel treatment.

Dale
Sir Henry Hallett, English physiologist and Nobel laureate, 1875–1968. See D. reaction, D.-Feldberg law, Schultz-D. reaction.

Dalen
Johan A., Swedish ophthalmologist, 1866–1940. See D.-Fuchs nodules, under nodule.

Dalgarno
Lynn, contemporary Australian molecular biologist.

Dalrymple
John, English oculist, 1803–1852. See D. sign.

Dalton
John, English chemist, mathematician, and natural philosopher, 1766–1844. See D. law, D.-Henry law, daltonian, daltonism.

dalton (Da) (dawl′ton)
Term unofficially used to indicate a unit of mass equal to 1/12 the mass of a carbon-12 atom, 1.0000 in the atomic mass scale; numerically, but not dimensionally, equal to molecular or particle weight (atomic mass units). [J D.]

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