12 结果
L1210 mouse leukemia cells provide a convenient model for examining the mechanisms and components involved in the active transport of various metabolites and drugs. One of these transport systems exhibits a broad specificity for folate compounds, including 4-amino antagonists such as methotrexate.
The cellular origin and the control of neopterin release associated with immune stimulation was studied in cell cultures. Using purified human mononuclear cells, the intracellular change in concentrations of GTP and pterins was measured under various kinds of stimulation. Three enzymes involved in
The concentrations of oncopterin, N2-(3-aminopropyl)biopterin, a new pterin compound, were determined in urine from various cancer patients by HPLC on a reverse-phase or ion-exchange column. The concentration of oncopterin increased after acid hydrolysis, indicating that it exists as an amide in
In a group of 14 individuals without tumor disease and 125 patients with verified malignant tumors we checked the applicability of determination of the pterins concentration in urine by the procedure described by RAO et al. [3]. In total of 242 examinations were performed. The results were compared
We have recently shown that the levels of urinary 6-hydroxymethylpterin are highly elevated (3 to 20 fold) in a variety of human malignancies as compared to its urinary excretion in patients with nonmalignant diseases or normal healthy subjects. In the subsequent studies, this parameter has been
In our earlier study it was shown that patients with various types of cancer excrete three- to 20-fold higher levels of urinary 6-hydroxymethylpterin as compared to patients with nonmalignant diseases or normal volunteers. In the present study urinary 6-hydroxymethylpterin levels have been measured
Previously, 8-deazafolic acid (17) was shown to be a potent inhibitor of the folate-dependent bacteria, Streptococcus faecium (ATCC 8043) and Lactobacillus casei (ATCC 7469), and to have activity against lymphoid leukemia L1210 in mice. To examine the 5,6,7,8-tetrahydro derivatives, a new synthesis
A series of folate analogs containing ornithine instead of glutamate was synthesized and tested for inhibition of folylpolyglutamate synthetase (FPGS) and other folate-dependent enzymes of human leukemia cell lines. Reduced derivatives of 2-amino-4-oxo-10-methyl-pteroyl-ornithine had dramatically
A previously identified cDNA encoding a human gamma-glutamyl hydrolase was expressed in a baculovirus system. The expressed protein had molecular mass of 37 kDa. Treatment of the protein with PNGase F produced a protein of molecular mass of 30 kDa, indicating that the protein contained
Two 17-mer oligodeoxynucleotide-5'-linked-(6,7-diphenylpterin) conjugates, 2 and 3, were prepared as photosensitisers for targeting photooxidative damage to a 34-mer DNA oligodeoxynucleotide (ODN) fragment 1 representing the chimeric bcr-abl gene that is implicated in the pathogenesis of chronic
N-Acetylserotonin (compound 1) and N-acetyldopamine (compound 7) inhibit bovine adrenal medullary sepiapterin reductase in a manner competitive with the pterin substrate and have Ki values of 0.12 and 0.4 microM, respectively. Molecular modeling suggests that the phenyl rings of the two compounds