Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.21 (thymidine kinase)
 7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cotransfer of two linked human genes, coding for the enzymes thymidine kinase (TK) and galactokinase (Gak) was demonstrated following incubation of Chinese hamster TK-deficient cells with isolated human chromosomes. The 5 colonies which were isolated all expressed a stable TK-positive phenotype. Cotransfer of the human genes coding for TK and Gak has also been observed in experiments in which isolated human chromosomes were incubated with TK-deficient human-Chinese hamster cell hybrids. These receipient hybrids had lost all human chromosomes at the time of incubation. From these experiments, four colonies were isolated, all expressing an unstable TK-positive phenotype. Using chromosome staining techniques, the presence of human chromosomes could not be demonstrated in either of the transformed clonal lines obtained with the Chinese hamster and the hybrid recipient cells. This indicates that incorporation of only the fragment of the human chromosome 17, bearing the genes for TK and Gak, has occurred in the recipient cells.
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PMID:Transfer of the human genes coding for thymidine kinase and galactokinase to Chinese hamster cells and human-Chinese hamster cell hybrids. 20 67

Comparison of methods to inactivate lytic properties of herpes simplex viruses revealed that ultraviolet irradiation, photodynamic procedures, and heat all destroyed infectivity effectively. Ability to biochemically transform thymidine kinase deficient cells to an enzyme positive phenotype was retained after limited exposure to heat or ultraviolet light but appeared to be destroyed by photodynamic methods employing neutral red. Exposure to 56 degrees C quickly and effectively destroyed transforming activity with lower temperatures being less effective. The most reproducible transforming assays were obtained following inactivation by ultraviolet light. Cell cultures developed by this procedure were virus-free but retained ability to synthesize virus-specific antigens.
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PMID:Biochemical Transformation of mouse cells by herpes simplex virus types 1 and 2: comparison of different methods for inactivation of viruses. 20 72

Cones of thioguanine resistant K-BALB mouse cells wereisolated which were inducible for endogenous type C virus synthesis by cycloheximide and dexamethsone, but not 5-iododeoxyuridine. A comparison of the number of foci formed on NRK and SC-I cells suggested that the xenotropic virus was suppressed. The variants were not defective in the incorporation of thymidine or iododeoxyuridine or deficient in thymidine kinase, but were deficient in hypoxanthine-guanine phosphoribosyltransferase and the incorporation of hypoxanthine into nucleic acid. Because these cells are blocked at some point in the expression of endogenous virus, they may prove useful in establishing the steps involved in chemical activation of virus synthesis.
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PMID:Isolation of thioguanine resistant variants of K-BALB cells non-inducible for type C viruses by 5-iododeoxyuridine. 20 30

During a 9-month period, 9,772 women were treated at the student health center's gynecology clinic. Herpes simplex virus was isolated from 30 of 57 patients clinically diagnosed as suffering from a herpetic or herpetic-like genial infection for a virological incidence rate of 0.31%. Using virus plaque diameter in chick embryo cells and heat stability of viral thymidine kinase, 37% of the isolates were classified as herpes simplex virus type 1 and 63% were classified as herpes simplex virus type 2.
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PMID:Incidence and distribution of herpes simplex virus types 1 and 2 from genital lesions in college women. 20 41

The Chinese hamster genes for thymidine kinase (ATP:thymidine 5'-phosphotransferase, EC 2.7.1.75) and galactokinase (ATP:D-galactose 1-phosphotransferase, EC 2.7.1.6) have been cotransferred to mouse cells by chromosome-mediated gene transfer. Hamster metaphase chromosomes were incubated with mouse B82 cells and 22 independent colonies were isolated in a selective medium. All of the 12 colonies analyzed expressed the donor form of thymidine kinase; the hamster form of galactokinase was also expressed in 2 of these colonies, indicating cotransfer with a frequency of about 20%. There was coordinate loss of both transferred genes from each colony when selection was applied for the loss of thymidine kinase alone. Comparison of the regional localization of these two linked genes with the frequency of cotransfer suggests that the transgenome is probably not larger than about 0.25% of the donor genome.
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PMID:Cotransfer of thymidine kinase and galactokinase genes by chromosome-mediated gene transfer. 20 39

The thymidine kinase inducing ability of 104 strains of herpes simplex virus was studied comparatively. A pronounced relationship was established between induction of the enzyme and the serotype of the strains. As a rule, the strains of serotype 2 are weaker inducer of dThd- and dCyd-kinase activity than serotype 1 strains. A certain parallelism exists between induction of both enzymes, however the activity of the thymidine kinase increases after infection with herpes simplex virus 4--5 times more than that of the dCyd-kinase. Adaptation of the strains to cell cultures only slightly modifies the inducing ability of the herpes simplex virus strains. The thymidine kinase activity induced by HSV-1 and HSV-2 differ from each other and are different from the cell enzyme with respect to their thermal stability at 40 degrees C. These differences are expressed more clearly in the presence of 480 muM dThdMP during inactivation. dThdMP stabilizes the type 1 but not the type 2 enzyme.
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PMID:Induction capacity and influence of dThdMP on thymidine kinase activity of type 1 and 2 strains of herpes simplex virus. 20 97

Replication of herpes simplex virus type I (HSV-I) was studied in various cell lines of rat nervous system origin. Infection of neonatal rat glial primary cells with HSV-I, strain KOS, produced normal yields of progeny virus. Glioma lines B9 and B15 were permissive, the neuronal line B50 was partially restricted (10 to 100-fold reduction) and the neuronal line B103 was non-permissive (greater than 1000-fold reduction) for HSV-I (KOS) replication. Synthesis of virus DNA in infected B103 cells was not detected. However, at least some virus macromolecular synthesis was induced, including production of thymidine kinase, DNA polymerase and virus structural proteins.
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PMID:Infection by herpes simplex virus and cells of nervous system origin: characterization of a non-permissive interaction. 20 30

Mouse teratocarcinoma cells from the OTT6050 ascites tumor were established in tissue culture and selected for 5-bromodeoxyuridine (BrdUrd) resistance. The embryonal carcinoma cells grew without a feeder layer, remained deficient for thymidine kinase (EC 2.7.1.75), and differentiated like the original tumor into various tissues after subcutaneous injection into 129 mice. We fused the BrdUrd-resistant mouse teratocarcinoma cells with HT1080-6TG human diploid fibrosarcoma cells deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8) and selected for hybrid cells in hypoxanthine/aminopterin/thymidine medium. The resulting hybrid cells segregated human chromosomes quickly and retained one to three human chromosomes including chromosome 17 that carries the human genes for thymidine kinase and galactokinase (EC 2.7.1.6). Single hybrid cells from five independent clones containing human chromosome 17 were injected into mouse blastocysts bearing several genetic markers that affect the coat color phenotype and strain-specific enzyme variants in order to detect tissue differentiation derived from the injected cells. After the injection of single hybrid cells into a total of 103 experimental blastocysts that had been surgically transferred to pseudopregnant foster mothers, 49 mice were born and 2 of them clearly revealed coat mosaicism. In 2 of 17 mice thus far analyzed, the injected hybrid cells proved to be capable of participating substantially in development of seven different organs. However, human gene products have not yet been detected unequivocally in those tissues and weak human-specific galactokinase activity could be recovered only from two mosaic tissues. Our results demonstrate that, after in vitro culture and selection, at least some of the human-mouse hybrid cells still retain their in vivo potential to differentiate and become functionally integrated in the living organism. It now seems feasible to cycle mouse teratocarcinoma cells carrying human genetic material through mice via blastocyst injection to study human gene expression during differentiation.
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PMID:Chimeric mice derived from human-mouse hybrid cells. 20 75

The biochemical transformation of thymidine kinase-deficient cells by UV-inactivated herpes simplex virus is enhanced by low-level photodynamic treatment of the infected cells. At the concentration of proflavine used, the virus was not inactivated and both virus and cellular DNA syntheses were only marginally inhibited. The observed enhancement of the transfer of a virus gene to the cell genome suggests a possible cocarcinogenic role for photodynamically active dyes at very low concentrations.
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PMID:Biochemical transformation of mouse cells by herpes simplex virus type 2: enhancement by means of low-level photodynamic treatment. 20 27

Superinfection of Raji cells with Epstein-Barr virus induced a new thymidine kinase that was distinguishable from both adult and fetal kinases of the host cell by discontinuous electrophoresis on polyacrylamide gels and glycerol gradients.
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PMID:Epstein-Barr virus-associated thymidine kinase. 20 28


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