Gene transfer with vectors derived from murine retroviruses is re stricted to cells which are proliferating and synthesizing DNA at the time of infection. This suggests that retroviral-mediated gene transfer might permit targeting of gene integration into malignant cells in organs com posed mainly of quiescent nonproliferating cells, such as in the brain. Accordingly, selective introduction of ...

of 16 hr produced a loss of cell viability accompanied by an inhibition of DNA synthesis. Continued synthesis of RNA and protein suggests an unbalanced growth similar to that previously observed with 5-fluorodeoxyuridine, excess thymidine, and 1-/8D-arabinofuranosylcytosine. A threefold increase in thymidine kinase activity was observed as a result of unbalanced growth following the exposure of...

The activities of thymidine kinase (TK) isoenzyme 1 and 2 were examined in extracts of human benign or malignant lymphoid tissue and correlated with degrees of morphological differentiation. TK2 activity occurred in peripheral blood lym phocytes of normal individuals, patients with chronic lymphocytic leukemia, or solid lymphoid tissue, exhibiting either nonneoplastic histological findings or t...

The mechanism of posttranscriptional regulation of thymidine kinase (TK) enzyme levels following serum stimulation of quiescent cells has been investigated using stably transfected Rat 3 (TK1 cells containing the human TK complementary DNA linked to a hybrid SV4O/human TK promoter. These cells expressed a wild-type human TK mRNA at relatively constant levels during the first G1 and S phase afte...

A simple procedure for preparation of an affinity resin with 3'-amino thymidine linked to the carboxyl residues on 6-amino-hexanoic agarose is described. We have used this column for a rapid and simple purification of the thymidine kinase encoded by the herpes simplex virus type 1 genome. This resin has two major advantages over the most widely use used resin made with thymidine-p-nitrophenyl p...

We have recently explored the cytokinetic effects of thymidine given by continuous infusion in an animal model and have demonstrated an arrest of cell cycle traverse in rapidly proliferating tissues. Similar biologic effects have been observed in clinical trials upon infusing thymidine at a dose rate of 75 g/sq m/day. Fifteen courses of at least 5 days in duration have been administered to 1 1 ...