No abstract

No abstract

The antitumor activity of cytostatic 5'-deoxy-5-fluorouridine (5'-dFUrd) depends on its being converted to 5-fluorouracil (5-FUra) by the enzyme thymidine phosphorylase (dThdPase, EC 2.42.4). We prepared mouse anti-human dThdPase monoclonal antibodies to serve as tools for clinical studies with this drug. Partially purified dThdPase obtained form HCT116 human colon cancer cells grown in athymic mice was used as and antigen for the immunization of mice. Six hybridomas were cloned which produced anti-human dThdPase antibodies, as detected by Western blot analysis with human dThdPase. With these antibodies, we developed an ELISA method sensitive enough to measure dThdPase levels, even in tumor tissue samples weighing as little as 10 mg. In addition, one monoclonal antibody was suitable for immunologically staining the enzyme in tumor tissues. Thus, these anti-human dThdPase monoclonal antibodies could be used to measure levels of the enzyme in tumor cells, which is essential for the activation of 5'-dFUrd.

Thymidine Phosphorylase (dThdPase) is the rate-tissues expressed high levels of DPD (median >70 U/mg limiting enzyme that metabolizes 5'-deoxy-5-fluorouridine protein), while high concentrations of the dThdPase were (5'-dFUrd, doxifluridine), an intermediate metabolite of expressed in esophageal, cervical, breast, and pancreatic capecitabine, to the active drug 5-fluorouracil (5-FUra), while cancers and hepatoma (median >150 U/mg protein). The dihydropyrimidine dehydrogenase (DPD) catabolizes 5-FUra dThdPase/DPD ratio, which was reported to correlate with to an inactive molecule. The susceptibility of tumors to the susceptibility of human cancer xenografts to capecitabine, fluoropyrimidines is reported to correlate with tumor levels was high in esophageal, renal, breast, colorectal, and gastric of these enzymes. To obtain some insight into the tumor cancers (median ratio of > 1.5). In any of these three parameters, types susceptible to fluoropyrimidine therapy, we measured the inter-patient DPD variability for each cancer type was expression levels of these two enzymes in various types of much larger than the DPD variability among cancer types; human cancer tissues (241 tissue samples) by the ELISA highest/lowest ratios for dThdPase, DPD, and dThdPase/DPD methods. DPD exists in all the cancer types studied, such were 10-321, 7-513, and 2-293, respectively. These results as bladder, breast, cervical, colorectal, esophageal, gastric, indicate that measurements of the three parameters, DPD, hepatic, pancreatic, prostate, and renal cancers. Among them, dThdPase and dThdPase/DPD, would be useful criteria for the cervical, hepatic, pancreatic, esophageal, and breast cancer selecting cancer patients suitable for fluoropyrimidine therapy rather than for selecting cancer types.

Glistenings formed in the bulk of an AcrySof IOL as the medium temperature decreased. The mechanism may involve spinodal decomposition of the swollen polymer network, which initiates the formation of microvacuoles consisting of water and loosely packed network chains.