Using an in vitro assay system, polybrominated biphenyl (PBB) was assessed for its ability to inhibit metabolic cooperation between 6-thioguanine sensitive and resistant Chinese hamster V79 cells. Using a nonlethal range of the chemical, PBB was shown to inhibit metabolic cooperation (a form of cell-cell communication) in a manner similar to other known tumor promoters. Results suggest that PBB...

This contribution builds on results from the EU-Project TAMI (Technology Assessment in Europe: Between Method and Impact). The general question to be answered in TAMI was ”How can TA-institutions optimise the impact of their projects?”. TAMI tackled this issue from two perspectives. The first one was straight forward: TA-practitioners must optimise their projects in order to increase their (?) ...

A series of phosphinegold(I) thionucleobase analogues, [R(3)PAu(SR(x))] (R = Et, Ph or chexyl; HSR(1) = 2-mercaptobenzoic acid, HSR(2) = 2-thiouracil, HSR(3) = 6-mercaptopurine and HSR(4) = 6-thioguanine) have been examined for their in vitro cytotoxicity in L1210 murine leukemia cells in culture. The range of ID(50) values (continuous 48 h exposure) for the complexes is 0.041 - 0.131 muM. The ...

The German cooperative study group for childhood acute lymphoblastic leukemia (COALL-92) was designed to examine the clinical effectiveness of thioguanine (TG) versus mercaptopurine (MP) in maintenance treatment of childhood acute lymphoblastic leukemia (ALL) in a randomized multicenter trial. TG and MP are prodrugs and have to be converted intracellularly to 6-thioguanine nucleotides (TGNs) fo...

OBJECTIVE To evaluate the outcomes of acute myeloid leukemia patients who were older than 60 years of age at the time of diagnosis following the implementation of a treatment algorithm based on age, performance status, and cytogenetic results. METHODS We retrospectively compared the results of 31 elderly acute myeloid leukemia patients (median age of 74 years) who were treated according to th...

of MMPR forms rapidly to levels of 1 to 2 mM in the tumor cells, and the steady-state levels of 5-phosphoribosyl 1-pyrophosphate increase 4to 5-fold in 6 to 12 hr. This permits a significantly greater synthesis of 6-thioguanosine monophosphate (6-thioGMP) after injection of 6-thioguanine. These findings are similar to those in previous reports concerning the synergism between 6-mercaptopurine a...

The transforming activity of DMA isolated from 6-mercaptopurine-treated cultures of Bacillus subtilis strain UTH-8505 is markedly reduced when compared to that of DMA obtained from control cultures. The lower transforming activity appears to be a property of the isolated DNA; i.e., various treatments either to restore the activity or to indicate the presence of inhibitory substances that isolat...

Objective: In this prospective study, we examined the association between azathioprine dose, levels of its phosphoribosylated metabolites, and the activity of thiopurine methyltransferase in patients with multiple sclerosis (MS). Materials/Methods: Clinical data and blood samples were collected from 27 MS patients who were undergoing azathioprine treatment. In red blood cells, thiopurine methyl...