The aims of our study were to assess the release of cytotoxic nucleoside analogs 5-fluorouracil and 2-chloro-2'-deoxyadenosine from different lactide-glycolide or lactide-caprolactone biodegradable copolymers and the effects of sterilization on this release. The polymers were sterilized either with ethylene oxide at 37 degrees C, or with gamma radiation (15 kGy, 20 kGy, or 25 kGy). The kinetics...

The pyrhnidine-nucleoside : orthophosphate ribosyltransferase (EC 2.4.2.2)) or pyrimidine nucleoside phosphorylase, from Bacillus sfearofhermophilus has been purified and compared with similar enzymes from Bacillus subfilis and Escherichia coli. The enzyme is stable at 60°, appears to be induced by either uridine or thymidine, and has a molecular weight of approximately 78,000. Unlike nucleosid...

The antiviral activity of nucleoside reverse transcriptase inhibitors is often limited by ineffective phosphorylation. We report on a nucleoside triphosphate (NTP) prodrug approach in which the γ-phosphate of NTPs is bioreversibly modified. A series of TriPPPro-compounds bearing two lipophilic masking units at the γ-phosphate and d4T as a nucleoside analogue are synthesized. Successful delivery...

BACKGROUND The potential prognostic value of human equilibrative nucleoside transporter1 in pancreatic cancer receiving gemcitabine-based chemotherapy is variably reported. OBJECTIVE The objective of this study was to conduct a systematic review of literature evaluating human equilibrative nucleoside transporter1 expression as a prognostic factor in pancreatic cancer receiving gemcitabine-bas...

The thymus is a site of active T-lymphoid cell proliferation and DNA synthesis. In this study, the capacity of human thymocytes for nucleoside transport was assessed both by cytosine arabinoside influx and by equilibrium binding of nitrobenzylmercaptopurine riboside (NBMPR), a specific ligand for the equilibrative nucleoside transporter of leukocytes. The proportion of freshly isolated thymocyt...

Nine fluorescent 5'-6-locked nucleosides were synthesized by condensation of various 1,2-diketones with 5-amino-2'-deoxycytidine. The nucleosides have different substituents on the pyrazine core structure, ranging from two methyl groups to polyaromatic rings. The photophysical properties of each nucleoside were determined, with the nucleosides displaying diverse absorption and emission maxima, ...

Ribose phosphates are either synthesized through the oxidative branch of the pentose phosphate pathway, or are supplied by nucleoside phosphorylases. The two main pentose phosphates, ribose-5-phosphate and ribose-1-phosphate, are readily interconverted by the action of phosphopentomutase. Ribose-5-phosphate is the direct precursor of 5-phosphoribosyl-1-pyrophosphate, for both de novo and 'salva...

Recent studies have considerably clarified the mechanism ofhydrolysis of ribonucleic acids (RNA) by pancreatic ribonuclease and by spleen phosphodiesterase. Digestion ofRNA with ribonuclease results in the splitting of all pyrimidine-pyrimidine internucleotidic links and of those pyrimidine-purine internucleotidic links which involve C(3w) of the pyrimidine nucleotide (Schmidt et al. 1951; Mark...