BACKGROUND Thiopurines are the prerequisite for immunomodulation in inflammatory bowel disease (IBD) therapy. When administered in high (oncological) dose, thiopurine metabolites act as purine antagonists, causing DNA-strand breakage and myelotoxicity. In lower IBD dosages, the mode of action is primarily restricted to anti-inflammatory effects. Then, myelosuppression and hepatotoxicity are the...

Carcinogenic arsenic, nickel, and chromium compounds induced morphological and neoplastic transformation but no mutation to ouabain resistance in 10T1/2 mouse embryo cells; lead chromate also did not induce mutation to ouabain or 6-thioguanine resistance in Chinese hamster ovary cells. The mechanism of metal-induced morphological transformation was likely not due to the specific base substituti...

6-Thioguanine (6-TG) was administered to 15 patients with acute leukemia and to 9 with solid tumors in 32 experiments, as part of Phase I testing of 6-TG. 6-TG and metabolites were measured by labeling the 6-TG with radiosulfur. The levels of 6-TG and metabolites were measured in blood and urine after p.o. and i.v. dosage. Incorporation into DNA and RNA of the bone marrow was measured. Blood le...

An, J. and A. W. Hsie (1993). "Polymerase chain reaction-based deletion screening of bleomycin induced 6-thioguanine-resistant mutants in Chinese hamster ovary cells: The effects of an inhibitor and a mimic of superoxide dismutase." Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 289(2): 215. http://www.sciencedirect.com/science/article/B6T2C-47PCN7M41/2/3157a48d39359d02b0...

Individualizing drug therapy by the use of pharmacogenomics offers the opportunity to improve drug efficacy, reduce adverse side effects, and provide cost-effective pharmaceutical care. 6-mercaptopurine (6-MP), 6-thioguanine (6-TG) and azathioprine (AZA) are widely prescribed cytotoxic and immunosuppressive drugs used in the therapy of acute leukaemia, inflammatory bowel diseases, allograft rej...

Children from riverside communities located downstream of gold mining areas may be chronically exposed to relatively high levels of MeHg through the consumption of fish of this region. The objective of this study was to evaluate and compare levels of THg and MeHg in hair of children less than 12 years in communities near mines in the municipality of Itaituba and in communities far from prospect...

The delayed cytotoxic effect of 6-thioguanine (TG) was studied using L1210 mouse leukemic cells in culture. The cell cycle distribution of a population treated continuously with 10(-5) M TG was compared to that of control cells using flow cytometric analysis. The TG-treated cells had an increase in the fraction of the population in G2-M, a decrease in G1, and a constant level in S phase. Howeve...

A series of subpopulation lines derived from a single mouse mammary tumor were tested for their ability to interact with each other in metabolic cooperation assays in three-dimensional collagen gel cultures. Inhibition of growth in the presence of selective drug (6-thioguanine or 2-fluoroadenine) of two 6-thioguanine-resistant cell lines, 66cl4 and 44FTO, as well as a 2-fluoroadenine-resistant ...