i J Vet Intern Med. 2004 Sep-Oct;18(5):696-702. Serum thymidine kinase activity in dogs with malignant lymphoma: a potent marker for prognosis and monitoring the disease. von Euler H, Einarsson R, Olsson U, Lagerstedt AS, Eriksson S. Source Faculty of Veterinary Medicine and Animal Science, Department of Small Animal Clinical Sciences, Swedish University of Agricultural Sciences (SLU), S-750 07...

Herpes simplex virus (HSV) infection of mouse liver after partial hepatectomy was studied. Partial hepatectomy resulted in the rapid onset of cellular DNA synthesis and the appearance of many mitotic figures (peak, 3 days after surgery). Similar changes were not seen in control animals. After partial hepatectomy, the mice were infected with thymidine kinase-positive (TK+) and -negative (TK-) HS...

Deoxynucleoside kinases catalyze the 5'-phosphorylation of 2'-deoxyribonucleosides with nucleoside triphosphates as phosphate donors. One of the cellular kinases, deoxycytidine kinase (dCK), has been shown to phosphorylate several L-nucleosides that are efficient antiviral agents. In this study we investigated the potentials of stereoisomers of the natural deoxyribonucleoside to serve as substr...

The human pathogenic parasite Trypanosoma brucei possess both de novo and salvage routes for the biosynthesis of pyrimidine nucleotides. Consequently, they do not require salvageable pyrimidines for growth. Thymidine kinase (TK) catalyzes the formation of dTMP and dUMP and is one of several salvage enzymes that appear redundant to the de novo pathway. Surprisingly, we show through analysis of T...

The thymidine kinases encoded by herpesviruses of higher vertebrates form a distinct group and are unrelated to the thymidine kinases (TKs) of other organisms. Their evolutionary source has not been identified, but our analysis has revealed a clear relationship with a sequence of human deoxycytidine kinase (dCK) published recently. We report the sequence of the putative TK of channel catfish vi...

Liver regeneration after partial hepatectomy (PH) has been employed as an experimental model of mammalian cell proliferation. Thymidine kinase (TK; E.C.2.7.1.21), an enzyme of the pyrimidine salvage pathway, catalyzes the phosphorylation of thymidine to thymidylate. Production of thymidylate by these enzymes is believed to be rate-limiting for DNA replication.1 The activity of this enzyme has b...

Clinical resistance to antiviral drugs requires that a virus evade drug therapy yet retain pathogenicity. Thymidine kinase (TK)-negative mutants of herpes simplex virus are resistant to the drug, acyclovir, but are attenuated for pathogenicity in animal models. However, numerous cases of clinical resistance to acyclovir have been associated with viruses that were reported to express no TK activ...

A series of deletions and insertions utilizing the herpesvirus thymidine kinase gene (tk) were constructed in the murine retrovirus Friend spleen focus-forming virus (SFFV). In all cases, the coding region for the SFFV-specific glycoprotein (gp55), which is implicated in erythroleukemic transformation, was left intact. These SFFV-TK and SFFV deletion vectors were analyzed for expression of tk a...

In this study, we demonstrate that the long terminal repeats (LTRs) of a murine retrovirus can activate expression of heterologous gene coding sequences from which a functional promoter region has been deleted. Recombinant plasmid clones were obtained that contained both cloned fragments of Friend spleen locus-forming virus (SFFV) DNA and the herpes simplex virus (HSV) thymidine kinase (TK; ATP...

OBJECTIVE The purpose of the study was to explore the anti-tumor effect of ultrasound -targeted microbubble destruction mediated herpes simplex virus thymidine kinase (HSV-TK) suicide gene system on mice hepatoma. METHODS Forty mice were randomly divided into four groups after the models of subcutaneous transplantation tumors were established: (1) PBS; (2) HSV-TK (3) HSV-TK+ ultrasound (HSV-T...