Abstract: Pharmaceutical compositions comprising a pharmaceutical composition comprising a compound which is an .alpha. or .beta. anomer, a D(+) or L(-) enantiomer of the following structural formula: ##STR1## wherein, R.sub.1 is a halogen, OR.sub.6, SR.sub.6, SeR.sub.6 or CH.sub.2 R.sub.6 and R.sub.6 is alkyl, alkene, arylalkyl, or aryl; ##STR2## X is CH.sub.2, O or S; R.sub.3 is H, OH, or a halogen;R.sub.4 is H, OH, or a halogen; andR.sub.5 is CH.sub.3, CF.sub.3, CH.sub.2 OH, or CH.sub.2 OY and Y is a carbon ester or phosphorus; anda pharmaceutically acceptable carrier.

Abstract: Methods and pharmaceutical compositions effective to increase intracellular and plasma uridine concentrations are disclosed. Certain compositions and methods of using such compositions have been found to be effective to inhibit uridine secretion in a subject, thus increasing uridine concentration. Treatments that increase uridine concentrations are useful to combat many treatments and can also be effective in protecting or rescuing uninfected and normal cells that are subject to toxic side effects induced by the administration of certain chemotherapeutic compounds.

Abstract: Novel compounds are provided that are effective to inhibit the activity of DHUDase or UrdPase. Such compounds have the general formula ##STR1## where X is S or Se; Y H is I, F, Cl, Br, methoxy, benzyl, selenenylphenyl, or thiophenyl, and R.sub.1 is H or an acyclo tail having the general formula ##STR2## where R.sub.2 is H, CH.sub.2 OH or CH.sub.2 NH.sub.2 ; R.sub.3 is OH, NH.sub.2, or OCOCH.sub.2 CH.sub.2 CO.sub.2 H; and R.sub.4 is O, S, or CH.sub.2.The compounds can be used in pharmaceutical compositions, along with various chemotherapeutic agents to increase the efficacy of the treatment. These compounds can also be used in methods of treating patients by coadministering or sequentially administering the enzyme inhibiting compounds with a chemotherapeutic agent effective to treat cancers, or viral, fungal, bacterial, or parasitic infections. The compounds have further utility in enhancing imaging.

Abstract: The present invention provides a method of predicting whether an individual will be intolerant to the effect of fluoropyrimidines comprising the step of measuring the activity of orotate phosphoribosyltransferase activity in a biological sample obtained from said individual. Also provided is a method of determining a non-toxic dose of 5-fluoruracil in an individual in need of fluoropyrimidine therapy, comprising the step of measuring the activity of 5-fluoruracil phosphoribosyltransferase (FUPRTase) in a biological sample obtained from said individual.

Abstract: A method of increasing intracellular and plasma uridine levels comprising the coadministration or sequential administration of a compound from at least two of the following groups:1) uridine phosphorylase inhibitors, uridine, cytidine, prodrugs of uridine, and prodrugs of cytidine;2) a uridine secretion inhibiting compound such as dilazep or hexobendine; and3) a compound which competes with uridine in renal transport mechanisms such as L-uridine, L-2',3'-dideoxyuridine, and D-2', 3'-dideoxyuridine.The elevation of plasma and intracellular levels of uridine reduces the toxicity of pyrimidine nucleoside chemotherapeutic agents.

Abstract: 5-benzyl barbiturate compounds for use as water-soluble uridine phosphorylase inhibitors are disclosed. These compounds are useful for reducing the toxicity and anemia induced by antiviral drugs such as AZT, as well as for potentiating anticancer drugs and combatting their host-toxicity.

Abstract: Treatments for viral infections are disclosed based on the finding that uridine can selectively protect and/or rescue uninfected cells, particularly human bone marrow progenitor cells, from the toxicity of pyrimidine nucleoside analogues during the treatment of retroviral diseases, such as AIDS, and that uridine phophorylase inhibitors are particularly effective in maintaining the necessary levels of uridine within such cells. A treatment for AIDS-type diseases is disclosed in which a pyrimidine nucleoside analogue and a uridine phosphorylase inhibitor are co-administered either simultaneously or sequentially to treat the viral infections and protect or rescue uninfected cells in the afflicted subject. This combination therapy also can be supplemented by direct administration of uridine.

Abstract: A compound of the Formula (I): ##STR1## where X is a benzyl group or a benzyloxybenzyl group and pharmaceutical preparations containing the same.

Abstract: Novel compounds are provided that are effective to inhibit the activity of DHUDase or UrdPase. Such compounds have the general formula where X is S or Se; Y is H, I, F, Cl, Br, methoxy, benzyl, selenenylphenyl, or thiophenyl, and R1 is H or an acyclo tail having the general formula where R2 is H, CH2 OH or CH2 NH2; R3 is OH, NH2, or OCOCH2CH2CO2H; and R4 is O, S, or CH2. The compounds can be used in pharmaceutical compositions, along with various chemotherapeutic agents to increase the efficacy of the treatment. These compounds can also be used in methods of treating patients by coadministering or sequentially administering the enzyme inhibiting compounds with a chemotherapeutic agent effective to treat cancers, or viral, fungal, bacterial, or parasitic infections. The compounds have further utility in enhancing imaging. Further, they can be administered alone to prevent and/or treat disorders of pyrimidine catabolism and other physiological disorders.