thioguanine

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thioguanine

 [thi″o-gwah´nēn]
a guanine analogue in which sulfur replaces the oxygen atom of guanine; used as an antineoplastic agent almost exclusively in the treatment of acute myelogenous leukemia and acute lymphoblastic leukemia. Called also 6-thioguanine and 6-TG.

thioguanine

Lanvis® Oncology An antimitotic purine analogue, used against AML. See Purine.

thioguanine

Tioguanine, a drug used in the treatment of acute myeloblastic leukaemia. A brand name is Lanvis.
References in periodicals archive ?
Orozco, "Theoretical study of the guanine [right arrow] 6-thioguanine substitution in duplexes, triplexes, and tetraplexes," Journal of the American Chemical Society, vol.
Hepatic veno-occlusive disease caused by 6-thioguanine.Ann Intern Med.
Hitchings, "The synthesis of 6-thioguanine," Journal of the American Chemical Society, vol.
[5] Nonstandard abbreviations: AZA, azathioprine; 6-MP, 6-mercaptopurine; 6-TGN, 6-thioguanine nucleotide; 6-MMPR, 6-methylmercaptopurine ribonucleotide; TPMT, thiopurine S-methyltransferase; TNF-[alpha], tumor necrosis factor-[alpha]; IBD, inflammatory bowel disease; XO, xanthine oxidase; HPRT, hypoxanthineguanine phosphoribosyltransferase; 6-MMP, 6-methylmercaptopurine; 5-ASA, 5-aminosalicylic acid.
(b) determining the level of 6-thioguanine in said subject having said immune-mediated gastrointestinal disorder wherein the level of 6-thioguanine less than about 230 pmol per 8x10^8 red blood cells indicates a need to increase the amount of said drug subsequently administered to said subject and wherein the level of 6-thioguanine greater than about 400 pmol per 8 x 10"8 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.
6-thioguanine nucleotides (6-TGN) are the active metabolites of AZA and result in inhibition of lymphocyte proliferation.
Azathioprine is converted to 6-mercaptopurine, which can be metabolized by xanthine oxidase to oxidized metabolites, by hypoxanthine-guanine phosphoribosyl transferase (HPRT) to 6-thioguanine nucleotides, or by thiopurine methyl transferase (TPMT) to 6-methylmercaptopurine (Fig.
2005) as well as racial differences in the genetic polymorphism of thiopurine S-methyltransferase (TPMT), a cystosolic enzyme that catalyzes the S-methylation of aromatic and hetercyclic sulfhydryl compounds, including 6-mercaptopurine, 6-thioguanine, and azathioprine (Hon, Fessing, Pui, Relling, Krynetski, & Evans 1999; Collie-Duguid et al.
In regard to drug resistance, MRP4 has been shown to efflux various chemotherapeutic agents, including topotecan, an anticancer agent, and 6-mercaptopurine and 6-thioguanine, two anticancer purine analogs.
Azathioprine metabolites showed significant shunting with a low 6-thioguanine and an elevated 6-methyl mercaptopurine, prompting a dose reduction to 25 mg daily and addition of allopurinol 50 mg daily.
Recently, chemically mutagenized haESC libraries have been used for identifying genes mediating 6-thioguanine (6-TG) toxicity.