Topic
Ultraviolet light
About: Ultraviolet light is a research topic. Over the lifetime, 49494 publications have been published within this topic receiving 843151 citations.
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TL;DR: A numerical argument is offered to establish the ability of Rec − cells successfully to replace excised pyrimidine-dimer-containing regions of the DNA with normal nucleotide residues.
180 citations
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TL;DR: In this article, the advancement in visible light induced initiating systems using free radical, cationic, and hybrid photoinitiators is reviewed, and the characteristics and limitations of some visible light initiating systems are compared and discussed in terms of the initiating efficiency, excitation wavelength, material cost and safety.
180 citations
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TL;DR: In this paper, a method for estimating the degree of proteolysis in ripening cheese was studied by measuring absorption of ultraviolet light by a clear, sodium citrate-hydrochloric acid extract of cheese at pH 4.4±0.05; these measurements were closely correlated with the per cent of soluble nitrogen in the cheese extract.
180 citations
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TL;DR: To form an organizer, zebrafish blastomeres appear to require substances which are transported from the vegetal hemisphere of the yolk cell by cortical microtubules, as shown by the movement of polystyrene beads.
180 citations
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TL;DR: Replication competent, TK-deleted VV appears to be an ideal vector for testing the in vivo delivery of toxic genes to tumor cells, and has a high transduction efficiency in tumor cells with high levels of gene expression.
Abstract: Tumor-directed gene therapy, such as "suicide gene" therapy, requires high levels of gene expression in a high percentage of tumor cells in vivo to be effective. Current vector strategies have been ineffective in achieving these goals. This report introduces the attenuated (thymidine kinase (TK)-negative) replication-competent vaccinia virus (VV) as a potential vector for tumor-directed gene therapy by studying the biodistribution of VV in animal tumor models. A TK-deleted recombinant VV (Western Reserve strain) expressing luciferase on a synthetic promoter was constructed. Luciferase activity was measured in vitro after transduction of a variety of human and murine tumor cell lines and in vivo after intraperitoneal (i.p.) delivery in C57BL/6 mice with 7-day i.p. tumors (10(6) MC-38 cells). Three other in vivo tumor models were examined for tumor-specific gene expression after intravenous delivery of VV (human melanoma in nude mice, adenocarcinoma liver metastasis in immunocompetent mice, and subcutaneous sarcoma in the rat). In addition, a replication-incompetent vaccinia (1 microg of psoralen and ultraviolet light, 365 nm, 4 minutes) was tested in vitro and in vivo and compared with active virus. Luciferase activity in i.p. tumors at 4 days after i.p. injection of VV was >7000-fold higher than lung, >3000-fold higher than liver, and >250-fold higher than ovary. In addition, intravenous injection of VV resulted in markedly higher tumor luciferase activity compared with any other organ in every model tested (up to 188,000-fold higher than liver and 77,000-fold higher than lung). Inactivation of the virus resulted in negligible gene expression in vivo. In summary, VV has a high transduction efficiency in tumor cells with high levels of gene expression. The results suggest a selective in vivo replication of TK-deleted VV in tumor cells. Replication competent, TK-deleted VV appears to be an ideal vector for testing the in vivo delivery of toxic genes to tumor cells.
180 citations