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Medical Dictionary


glycocholate (gli-ko-ko′lat)
A salt or ester of glycocholic acid. g. sodium a normal constituent of bile of humans and herbivores; g. sodium from herbivores is purified and used as a choleretic and cholagogue.

glycocholic acid (gli-ko-ko′lik)
N-Cholylglycine;one of the major bile acid conjugates, formed by condensation of the &cbond;COOH group of cholic acid and the amino group of glycine; water-soluble and a powerful detergent.

glycoconjugates (gli-ko-kon′joo-gatz)
A general class of sugar-containing macromolecules of the body including glycolipids, glycoproteins, and proteoglycans.

glycocorticoid (gli′ko-kor′ti-koyd)
SYN: glucocorticoid.

glycocyamine (gli-ko-si′a-men)
2-Guanidinoacetic acid;formed by the transfer of the amidine group from l-arginine to glycine. SYN: glucocyamine.

glycogelatin (gli-ko-jel′a-tin)
SYN: glycerinated gelatin.

glycogen (gli′ko-jen)
A glucosan of high molecular weight, resembling amylopectin in structure [with α(1,4) linkages] but with even more highly branched [α(1,6) linkages, as well as a small number of α(1,3) linkages], found in most of the tissues of the body, especially those of the liver and muscle; as the principal carbohydrate reserve, it is readily converted into glucose. SYN: animal dextran, animal starch, hepatin, liver starch. g. phosphorylase SYN: phosphorylase. g. synthase, g. starch synthase a glucosyltransferase catalyzing the incorporation of d-glucose from UDP-d-glucose into 1,4-α-d-glucosyl chains. A deficiency of the liver enzyme may lead to a type of hypoglycemia.

glycogenase (gli′ko-je-nas)
SYN: α-amylase, β-amylase.

glycogenesis (gli-ko-jen′e-sis)
Formation of glycogen from d-glucose by means of glycogen synthase and dextrin dextranase; the first enzyme catalyzes formation of a polyglucose with α-1,4 links from UDPglucose, the second cleaves fragments from one chain and transfers them to an α-1,6 linkage in another. [glyco- + G. genesis, production]

glycogenetic (gli′ko-je-net′ik)
Relating to glycogenesis. SYN: d-glycogenous.

glycogenic (gli-ko-gen′ik)
Giving rise to or producing glycogen.

glycogenolysis (gli′ko-je-nol′i-sis)
The hydrolysis of glycogen to glucose.

glycogenosis (gli′ko-je-no′sis)
Any of the glycogen deposition diseases characterized by accumulation of glycogen of normal or abnormal chemical structure in tissue; there may be enlargement of the liver, heart, or striated muscle, including the tongue, with progressive muscular weakness. Seven types (Cori classification) are recognized, depending on the enzyme deficiency involved, all of autosomal recessive inheritance, but with a different gene for each enzyme deficiency. [MIM designations: 1, *232200, *232220, *232240; 2, *232300; 3, *232400; 4, *232500; 5, *232600; 6, *232700; 7, *232800]. SYN: dextrinosis, glycogen-storage disease. brancher deficiency g. SYN: brancher glycogen storage disease. generalized g. SYN: type 2 g.. glucose-6-phosphatase hepatorenal g. SYN: type 1 g.. hepatophosphorylase deficiency g. SYN: type 6 g.. myophosphorylase deficiency g. SYN: type 5 g.. type 1 g. g. due to glucose 6-phosphatase deficiency, resulting in accumulation of excessive amounts of glycogen of normal chemical structure, particularly in liver and kidney. SYN: Gierke disease, glucose-6-phosphatase hepatorenal g., von Gierke disease. type 2 g. g. due to lysosomal α-1,4-glucosidase deficiency, resulting in accumulation of excessive amounts of glycogen of normal chemical structure in heart, muscle, liver, and nervous system. SYN: generalized g., Pompe disease. type 3 g. g. due to amylo-1,6-glucosidase deficiency, resulting in accumulation of abnormal glycogen with short outer chains in liver and muscle. SYN: Cori disease, debranching deficiency limit dextrinosis, limit dextrinosis, Forbes disease. type 4 g. familial cirrhosis of the liver with storage of abnormal glycogen; g. due to deficiency of 1,4-α-glucan branching enzyme, resulting in accumulation of abnormal glycogen with long inner and outer chains in liver, kidney, muscle, and other tissues. SYN: Andersen disease. type 5 g. g. due to muscle glycogen phosphorylase deficiency, resulting in accumulation of glycogen of normal chemical structure in muscle. SYN: McArdle disease, McArdle syndrome, McArdle-Schmid-Pearson disease, myophosphorylase deficiency g.. type 6 g. g. due to hepatic glycogen phosphorylase deficiency, resulting in accumulation of glycogen of normal chemical structure in liver and leukocytes. SYN: hepatophosphorylase deficiency g., Hers disease. type 7 g. phosphofructokinase deficiency of muscle resulting in muscle cramps and myoglobinuria on extreme exertion. The clinical picture resembles type 5 g..

glycogeusia (gli-ko-goo′se-a)
A subjective sweet taste. [glyco- + G. geusis, taste]

glycoglycinuria (gli′ko-gli-si-noo′re-a) [MIM*138070]
A metabolic disorder characterized by glucosuria and hyperglycinuria; autosomal dominant inheritance.

glycohistochemistry (gli-ko-his-to-kem′-is-tre)
Study of specific sugar moieties in tissue. lectin g. technique for measuring the endogenous ligands for specific sugar moieties, such as peanut agglutinin, wheat germ agglutinin, and gores seed agglutinin, in characterization of surface epithelium.

glycol (gli′kol)
1. A compound containing two alcohol groups. 2. Ethylene g., HOCH2CH2OH, the simplest g..

glycolaldehyde (gli-kol-al′de-hid)
HOCH2CHO;the simplest (2-carbon) sugar; the aerobic deamination product of ethanolamine. SYN: diose. active glycoaldehyde 2-(1,2-dihydroxyethyl)thiamin pyrophosphate;a derivative formed in carbohydrate metabolism.

glycolaldehydetransferase (gli-kol-al′de-hid-trans′fer-as)
SYN: transketolase.

glycolate (gli-ko′lat)
A salt or ester of glycolic acid.

glycoleucine (gli′ko-loo-sin)
SYN: norleucine.

glycolic acid (gli-kol′ik)
An intermediate in the interconversion of glycine and ethanolamine. SYN: hydroxyacetic acid.

glycolic aciduria
Excessive excretion of glycolic acid in the urine; a primary metabolic defect due to deficiency of 2-hydroxy-3-oxoadipate carboxylase, resulting in excretion of glycolic and oxalic acids, leading to the clinical syndrome of oxalosis.

glycolipid (gli-ko-lip′id)
A lipid with one or more covalently attached sugars.

glycolyl (gli′ko-lil)
HOCH2CO–;the acyl radical of glycolic acid, replacing acetyl in some sialic acids; the products are called N-glycolylneuraminic acids.

glycolylurea (gli′ko-lil-u-re′a)
SYN: hydantoin.

glycolysis (gli-kol′i-sis)
The energy-yielding conversion of d-glucose to lactic acid (instead of pyruvate oxidation products) in various tissues, notably muscle, when sufficient oxygen is not available (as in an emergency situation); since molecular oxygen is not consumed in the process, this is frequently referred to as “anaerobic g.” Cf.:Embden-Meyerhof-Parnas pathway. SYN: glucolysis. [glyco- + G. lysis, a loosening]

glycolytic (gli-ko-lit′ik)
Relating to glycolysis.

glyconeogenesis (gli′ko-ne-o-jen′e-sis)
1. The formation of glycogen from noncarbohydrates, such as protein or fat, by conversion of the latter to d-glucose. SEE ALSO: glycogenesis. 2. SYN: gluconeogenesis. [glyco- + G. neos, new, + genesis, production]

glyconic acids (gli-kon′ik)
SYN: aldonic acids.

glycopenia (gli-ko-pe′ne-a)
A deficiency of any or all sugars in an organ or tissue. [glyco- + G. penia, poverty]

glycopeptide (gli-ko-pep′tid)
A compound containing sugar(s) linked to amino acids (or peptides), with the latter preponderant, as in bacterial cell walls. Cf.:peptidoglycan.

Glycophagus (gli-kof′a-gus)
A common genus of grain mites, frequently implicated in dermatitis among food handlers. SEE ALSO: Tyrophagus putrescentiae. [glyco- + G. phago, to eat]

glycophilia (gli-ko-fil′e-a)
A condition in which there is a distinct tendency to develop hyperglycemia, even after the ingestion of a relatively small quantity of glucose. [glyko- + G. phileo, to love]

glycophorins (gli-ko-for′ins)
A group of glycoproteins found in erythrocyte membranes; certain g. are associated with blood group antigens; glycophorin A is the major glycophorin; a deficiency of glycophorin C is observed in type 4 hereditary elliptocytosis.

glycoprotein (gli-ko-pro′ten)
1. One of a group of proteins containing covalently linked carbohydrates, among which the most important are the mucins, mucoid, and amyloid. 2. Sometimes restricted to proteins containing small amounts of carbohydrate, in contrast to mucoids or mucoproteins, usually measured as hexosamine; such conjugated proteins are found in many places, notably γ-globulins, α1-globulins, α2-globulins, transferrin, etc., and are contained in mucus and mucins. SEE ALSO: mucoprotein. α1-acid g. SYN: orosomucoid.

glycoptyalism (gli-ko-ti′a-lizm)
SYN: glycosialia. [glyco- + G. ptyalon, saliva]

glycopyrrolate (gli-ko-pi′ro-lat)
A parasympatholytic compound (like atropine) used as premedication prior to general anesthesia, as an antagonist to the bradycardic effects of neostigmine during curare reversal, and as an adjunct in the treatment of peptic ulcer.

glycorrhachia (gli-ko-ra′ke-a, -rak-e-a)
Presence of sugar in the cerebrospinal fluid. [glyco- + G. rhachis, spine]

glycorrhea (gli-ko-re′a)
A discharge of sugar from the body, as in glucosuria, especially in unusually large quantities. [glyco- + G. rhoia, a flow]

glycosaminoglycan (GAG) (gli′kos-am-i-no-gli′kan)
See mucopolysaccharide.

glycosecretory (gli′ko-se-kre′to-re)
Causing or involved in the secretion of glycogen.

glycosialia (gli′ko-si-al′e-a, -a′le-a)
The presence of sugar in the saliva. SYN: glycoptyalism. [glyco- + G. sialon, saliva]

glycosialorrhea (gli′ko-si′a-lo-re′a)
An excessive secretion of saliva that contains glucose. [glyco- + G. sialon, saliva, + rhoia, a flow]

glycosidases (gli-ko-sid-as′ez)
(gli-ko-sid-as′ez;)A class of hydrolytic enzymes that act on glycosides; α-g. act on α-glycosidic linkages ( e.g., α-amylase) while β-g. act on β-glycosidic linkages ( e.g., β-glucosidase). They can be further divided into those enzymes that act on O-glycosyl, N-glycosyl, or S-glycosyl compounds.

glycoside (gli′ko-sid)
Condensation product of a sugar with any other radical involving the loss of the OH of the hemiacetal or hemiketal of the sugar, leaving the anomeric carbon as the link; thus, the condensation through the carbon with an alcohol, which loses its hydrogen on its hydroxyl group, yields an alcohol-g. (or a glycosido-alcohol); links with a purine or pyrimidine –NH– group yield glycosyl (or N-glycosyl) compounds. cardiac glycosides generic term for a large number of drugs with the capacity to increase the force of contraction of the failing heart. Examples include digitalis (foxglove) extracts as well as those obtained from other plant and animal sources. cyanogenic g. a g. capable of generating CN− upon metabolism ( E.G., amygdalin).

glycosidic (gli-ko-sid′ik)
Referring to or denoting a glycoside or glycoside linkage.

glycosphingolipid (gli′ko-sfing-go-lip′id)
A ceramide linked to one or more sugars via the terminal OH group; included as glycosphingolipids are cerebrosides, gangliosides, and ceramide oligosaccharides (oligoglycosylceramides). The prefix glyc- may be replaced by gluc-, galact-, lact-, etc. SYN: ceramide saccharide.

glycostatic (gli-ko-stat′ik)
Indicating the property of certain extracts of the anterior hypophysis that permits the body to maintain its glycogen stores in muscle, liver, and other tissues.

glycosuria (gli-ko-soo′re-a)
1. SYN: glucosuria. 2. Urinary excretion of carbohydrates. SYN: glycuresis (2) . [glyco- + G. ouron, urine] alimentary g. g. developing after the ingestion of a moderate amount of sugar or starch, which normally is disposed of without appearing in the urine, because rate of intestinal absorption exceeds capacity of the liver and the other tissues to remove the glucose, thus allowing blood glucose levels to become high enough for renal excretion to occur. SYN: alimentary diabetes, digestive g.. benign g. g. not associated with diabetes mellitus but resulting from a low renal threshold for sugar. digestive g. SYN: alimentary g.. nondiabetic g. SYN: nonhyperglycemic g.. nonhyperglycemic g. presence of glucose in the urine without hyperglycemia due to abnormality in renal tubular reabsorption of filtered glucose. SYN: nondiabetic g., orthoglycemic g.. normoglycemic g. SYN: renal g.. orthoglycemic g. (or-tho-gli′cem-ik) SYN: nonhyperglycemic g.. pathologic g. chronic excretion of relatively large amounts of sugar in the urine. phlorizin g., phloridzin g. the presence of sugar in the urine after the experimental administration of phlorizin, which results in a lower renal threshold for glucose reabsorption of glucose. SYN: phlorizin diabetes. renal g. the recurring or persistent excretion of glucose in the urine, in association with blood glucose levels that are in the normal range; results from the failure of proximal renal tubules to reabsorb glucose at a normal rate from the glomerular filtrate (low renal threshold); defect in the glucose carrier in the nephron. SYN: normoglycemic g., renal diabetes.

glycosyl (gli′ko-sil)
The radical resulting from detachment of the OH of the hemiacetal or hemiketal of a saccharide. Cf.:glycoside.

glycosylation (gli′ko-si-la′shun)
Formation of linkages with glycosyl groups, as between d-glucose and the hemoglobin chain to form the fraction hemoglobin AIc, whose level rises in association with the raised blood d-glucose concentration in poorly controlled or uncontrolled diabetes mellitus. SEE ALSO: glycosylated hemoglobin.

glycosyltransferase (gli′ko-sil-trans′fer-as)
Any enzyme (EC subclass 2.4) transferring glycosyl groups from one compound to another. SYN: transglycosylase.

glycotropic, glycotrophic (gli-ko-trop′ik, -trof′ik)
Pertaining to a principle in extracts of the anterior lobe of the pituitary that antagonizes the action of insulin and causes hyperglycemia. [glyco- + G. trophe, nourishment; trope, a turning]

glycuresis (gli-koo-re′sis)
1. SYN: glucosuria. 2. SYN: glycosuria (2) . [glyco- + G. ouresis, urination]

glycuronate (gli-koor′on-at)
A salt or ester of a glycuronic acid.

glycuronic acid (gli-koor-on′ik)
The uronic acid of a sugar in which the terminal carbon is oxidized to a carboxyl group.

glycuronidase (gli-koor-on′i-das)
SYN: β-d-glucuronidase.

glycuronide (gli-koor′on-id)
A glycoside of a uronic acid; e.g., glucuronide.

glycuronuria (gli-koo-ro-noo′re-a)
The presence of glucuronic acid in the urine.

glycyclamide (gli-si′kla-mid)
An oral hypoglycemic agent. SYN: cyclamide, tolcyclamide, tolhexamide.

glycyl (Gly) (gli′sil)
The acyl radical of glycine.

glycyrrhiza (glis-i-ri′za)
The dried rhizome and root of G. glabra (family Leguminoseae) and allied species; a demulcent, mild laxative, and expectorant; also used to disguise the taste of other remedies; its action appears to depend upon glycyrrhizic acid, a salt-retaining glycoside that mimics the action of aldosterone. SYN: licorice, liquorice. [G. fr. glykys, sweet, + rhiza, root]

glyoxal (gli-oks′al)
OHC&cbond;CHO;the simplest dialdehyde. SYN: oxalaldehyde.

glyoxalase (gli-oks′a-las)
An enzyme, lactoylglutathione lyase (g. I) or hydroxyacylglutathione hydrolase (g. II), in red cells and other tissues that converts glyoxal and substituted glyoxals bound to glutathione into the corresponding free hydroxy acids (g. II) or glyoxals (g. I).

glyoxylate transacetylase (gli-oks′i-lat)
SYN: malate synthase.

glyoxyldiureide (gli-oks-il-di′u-rid)
SYN: allantoin.

glyoxylic acid (gli-oks-il′ik)
OHC&cbond;COOH;produced by the action of glycine dehydrogenases upon glycine or sarcosine, or from allantoic acid by allantoicase or via alanine:glyoxylate aminotransferase. SYN: oxoacetic acid.

Former abbreviation for gram.

Abbreviation for granulocyte-macrophage colony-stimulating factor.

Leopold, German physiologist and chemist, 1788–1853. See G. test, Rosenbach-G. test.

Abbreviation for guanylic acid.

GMP reductase
Abbreviation for guanylic acid reductase.

GMP synthetase
Abbreviation for guanylic acid synthetase.

Abbreviation for Gomori methenamine-silver stain, under stain.

gnashing (nash′ing)
The grinding together of the teeth as a nonmasticatory function; sometimes associated with emotional tension. SEE ALSO: bruxism.


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