6 Mercaptopurine
Mostrando 13-24 de 36 artigos, teses e dissertações.
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13. Effect of 6-Mercaptopurine on Endotoxin Tolerance*
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14. THE EFFECTS OF 6-MERCAPTOPURINE ON HOMOGRAFT REACTIONS *
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15. Inhibition by 6-Mercaptopurine of Polyarthritis induced by Freund's Adjuvant
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16. THE EFFECT OF 6-MERCAPTOPURINE ON PRIMARY AND SECONDARY IMMUNE RESPONSES *
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17. Incorporation of Exogenous Purines and Pyrimidines by Methanococcus voltae and Isolation of Analog-Resistant Mutants
Methanococcus voltae incorporated exogenous adenine, guanine, hypoxanthine, and uracil, but not thymine. Growth of M. voltae was also sensitive to purine and pyrimidine analogs. Of the 20 analogs tested, 12 were inhibitory at 1 mg/ml. The most effective inhibitors were purine analogs with endocyclic substitutions. Nucleoside analogs and analogs with exocycli
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18. Enhanced Toxicity for Mice of 6-Mercaptopurine with Bacterial Endotoxin
The toxicity of 6-mercaptopurine was potentiated by 2 mg of either Escherichia coli 026:B6 B endotoxin or Salmonella typhosa 0901 W endotoxin per kg. Nonlethal doses of heat-killed, gram-negative bacteria were also capable of potentiating the lethality of 6-mercaptopurine (6-MP). Salmonella minnesota S, the wild-type strain, and S. minnesota Re 595, a mutant
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19. Comparative Study of 6-Mercaptopurine Metabolism in Human Leukemic Leukocytes and L1210 Cells
Leukocytes from patients with leukemia and L1210 cells from mice were examined for the rate of formation and cellular concentration of phosphoribosylpyrophosphate, the rate of thioinosinic acid formation, and a number of selected enzymes involved in purine nucleotide synthesis. The amount of thioinosinic acid formed in L1210 cells was much higher than that i
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20. Methotrexate/6-mercaptopurine maintenance therapy influences the risk of a second malignant neoplasm after childhood acute lymphoblastic leukemia: results from the NOPHO ALL-92 study
Among 1614 children with acute lymphoblastic leukemia (ALL) treated with the Nordic Society for Paediatric Haematology and Oncology (NOPHO) ALL-92 protocol, 20 patients developed a second malignant neoplasm (SMN) with a cumulative risk of 1.6% at 12 years from the diagnosis of ALL. Nine of the 16 acute myeloid leukemias or myelodysplastic syndromes had monos
American Society of Hematology.
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21. Control by Cesium and Intermediates of the Citric Acid Cycle of Extracellular Ribonuclease and Other Enzymes Involved in the Assimilation of Nitrogen
Synthesis of extracellular ribonuclease is induced in cell cultures of Ustilago sphaerogena that are starved for nitrogen and exposed to the gratuitous inducer, 6-mercaptopurine. Cesium, ammonium, or alkylammonium ion represses ribonuclease induction. Addition of citric-acid cycle intermediates to cesium ionrepressed cultures partially restores the rate of r
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22. 6-Thioguanine alters the structure and stability of duplex DNA and inhibits quadruplex DNA formation.
The ability to chemically synthesize biomolecules has opened up the opportunity to observe changes in structure and activity that occur upon single atom substitution. In favorable cases this can provide information about the roles of individual atoms. The substitution of 6-thioguanine (6SG) for guanine is a potentially very useful single atom substitution as
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23. Genetic evidence for a repressor of synthesis of cytosine deaminase and purine biosynthesis enzymes in Escherichia coli.
Addition of purines to the growth medium of Escherichia coli represses synthesis of cytosine deaminase (codA) and enzymes of purine de novo synthesis. After Tn10 mutagenesis, mutants displaying derepressed levels of cytosine deaminase in the presence of hypoxanthine were isolated. One of these had simultaneously acquired resistance to the hypoxanthine analog
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24. Production of specific site probes of tRNA structure by enrichment with carbon 13 at particular locations.
Escherichia coli C6 rel met cys was cultured in a stringently defined minimal medium containing 13C-enriched metabolites in order to (1) achieve maximal 13C isotopic enrichment of tRNA; and (2) produce site specific but natural, non-perturbing NMR probes of tRNA structure and function. Growth conditions were manipulated to achieve optimal culture growth conc