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61.
Jelinek J; Fairbairn LJ; Dexter TM; Rafferty JA; Stocking C; Ostertag W; Margison GP 《Blood》1996,87(5):1957-1961
A human O6-alkylguanine-DNA-alkyltransferase (ATase) cDNA-containing retrovirus was used to infect murine long-term primary bone marrow cultures. High levels of ATase expression were obtained, and colony- forming cells of the granulocyte-macrophage lineage from the cultures transduced with the human ATase retrovirus were three times more resistant to the alkylating agent, N-methyl-N-nitrosourea (MNU), than control cultures. Furthermore, expression of the human ATase protected long-term hematopoiesis, measured as the output of progenitor cells to the nonadherent fraction of the culture, against the cytotoxic effects of repeated exposures to MNU. These results clearly show that a human ATase cDNA-containing retrovirus can be used to infect long-term primary bone marrow cultures and that this attenuates their sensitivity to nitrosoureas. 相似文献
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Jannine D. Cody Courtney Sebold Patricia Heard Erika Carter Bridgette Soileau Minire Hasi-Zogaj Annice Hill David Rupert Brian Perry Louise O'Donnell Jon Gelfond Jack Lancaster Peter T. Fox Daniel E. Hale 《American journal of medical genetics. Part C, Seminars in medical genetics》2015,169(3):265-280
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Chih H. King Eric Lancaster Daniela Salomon Elior Peles Steven S. Scherer 《The Journal of comparative neurology》2014,522(14):3262-3280
The Kv7 (KCNQ) family of voltage‐gated K+ channels regulates cellular excitability. The functional role of Kv7.2 has been hampered by the lack of a viable Kcnq2‐null animal model. In this study, we generated homozygous Kcnq2‐null sensory neurons using the Cre‐Lox system; in these mice, Kv7.2 expression is absent in the peripheral sensory neurons, whereas the expression of other molecular components of nodes (including Kv7.3), paranodes, and juxtaparanodes is not altered. The conditional Kcnq2‐null animals exhibit normal motor performance but have increased thermal hyperalgesia and mechanical allodynia. Whole‐cell patch recording technique demonstrates that Kcnq2‐null sensory neurons have increased excitability and reduced spike frequency adaptation. Taken together, our results suggest that the loss of Kv7.2 activity increases the excitability of primary sensory neurons. J. Comp. Neurol. 522:3262–3280, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
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Transoral laser microsurgery for oropharyngeal squamous cell carcinoma: A paradigm shift in therapeutic approach
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Mark D. Wilkie MRCS DO‐HNS Navdeep S. Upile MRCS DO‐HNS Andrew S. Lau MRCS DO‐HNS Stephen P. Williams MRCS Jon Sheard FRCPath Tim R. Helliwell FRCPath Max Robinson FRCPath Jennifer Rodrigues FRCA Krishna Beemireddy FRCA Huw Lewis–Jones FRCR Rebecca Hanlon FRCR David Husband FRCR Aditya Shenoy FRCR Nicholas J. Roland FRCS Shaun R. Jackson FRCS Fazilet Bekiroglu FRCS Sankalap Tandon FRCS Jeffrey Lancaster FRCS Terence M. Jones FRCS 《Head & neck》2016,38(8):1263-1270
70.
Experimental support for the "E pathway hypothesis" of coupled transmembrane e- and H+ transfer in dihemic quinol:fumarate reductase
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Lancaster CR Sauer US Gross R Haas AH Graf J Schwalbe H Mäntele W Simon J Madej MG 《Proceedings of the National Academy of Sciences of the United States of America》2005,102(52):18860-18865
Reconciliation of apparently contradictory experimental results obtained on the quinol:fumarate reductase, a diheme-containing respiratory membrane protein complex from Wolinella succinogenes, was previously obtained by the proposal of the so-called "E pathway hypothesis." According to this hypothesis, transmembrane electron transfer via the heme groups is strictly coupled to cotransfer of protons via a transiently established pathway thought to contain the side chain of residue Glu-C180 as the most prominent component. Here we demonstrate that, after replacement of Glu-C180 with Gln or Ile by site-directed mutagenesis, the resulting mutants are unable to grow on fumarate, and the membrane-bound variant enzymes lack quinol oxidation activity. Upon solubilization, however, the purified enzymes display approximately 1/10 of the specific quinol oxidation activity of the wild-type enzyme and unchanged quinol Michaelis constants, K(m). The refined x-ray crystal structures at 2.19 A and 2.76 A resolution, respectively, rule out major structural changes to account for these experimental observations. Changes in the oxidation-reduction heme midpoint potential allow the conclusion that deprotonation of Glu-C180 in the wild-type enzyme facilitates the reoxidation of the reduced high-potential heme. Comparison of solvent isotope effects indicates that a rate-limiting proton transfer step in the wild-type enzyme is lost in the Glu-C180 --> Gln variant. The results provide experimental evidence for the validity of the E pathway hypothesis and for a crucial functional role of Glu-C180. 相似文献