Uridine Kinase: An enzyme that catalyzes the phosphorylation of uridine and cytidine to uridine 5'-phosphate and cytidine 5'-phosphate, respectively. ATP, dUTP, dGTP, and dATP are effective phosphate donors. EC 126.96.36.199.Phosphotransferases: A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.Uridine Phosphorylase: An enzyme that catalyzes the transfer of ribose from uridine to orthophosphate, forming uracil and ribose 1-phosphate.Guanine Deaminase: An enzyme that catalyzes the deamination of guanine to form xanthine. EC 188.8.131.52.Azauridine: A triazine nucleoside used as an antineoplastic antimetabolite. It interferes with pyrimidine biosynthesis thereby preventing formation of cellular nucleic acids. As the triacetate, it is also effective as an antipsoriatic.UridineCytidine Triphosphate: Cytidine 5'-(tetrahydrogen triphosphate). A cytosine nucleotide containing three phosphate groups esterified to the sugar moiety.Carcinoma, Ehrlich Tumor: A transplantable, poorly differentiated malignant tumor which appeared originally as a spontaneous breast carcinoma in a mouse. It grows in both solid and ascitic forms.