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151.
M Roelke AD Bernstein V Parsonnet 《Canadian Metallurgical Quarterly》1997,20(6):1744; author reply 1747-1744; author reply 1748
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H Witschi I Espiritu RR Maronpot KE Pinkerton AD Jones 《Canadian Metallurgical Quarterly》1997,18(11):2035-2042
Female strain A/J mice were exposed to unfiltered or HEPA-filtered environmental tobacco smoke (ETS). Total suspended particulates (TSP) in the full smoke exposure chamber was 78.5 mg/m3 and in the filtered smoke chamber 0.1 mg/m3; nicotine concentrations in the full and filtered smoke chamber were 13.4 and 3.1 mg/m3, respectively. Animals exposed to filtered ETS (6 h a day, 5 days a week) and killed after 5 months had a higher lung tumor incidence and multiplicity than controls maintained in filtered air, although the differences were not statistically significant. Animals exposed to filtered and full ETS and allowed to recover in air for 4 months had an average of 1.2 +/- 0.3 tumors per lung and 1.3 +/- 0.3 tumors per lung, respectively. Air exposed control animals had an average tumor multiplicity 0.5 +/- 0.1 tumors per lung. Increased immunostaining for CYP 1A1 was not evident in the lung of animals exposed to filtered smoke. Based on the chamber concentrations of selected nitrosamines and polycyclic aromatic hydrocarbons, the possible maximum uptakes by the mice of NNK, NNN and benzo[a]pyrene during the 5 months exposure period were three to six orders of magnitude below doses reported in the literature to produce 1 lung tumor in strain A/J mice. It was concluded that the gas phase of ETS is as carcinogenic as is full ETS. The carcinogenicity of the gas phase may be due to some as yet unidentified, yet highly potent carcinogens or by placing a substantial, possibly free radical-mediated oxidative stress on the lung. 相似文献
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AD Pechulis RJ Thompson JP Fojtik HM Schwartz CA Lisek LL Frye 《Canadian Metallurgical Quarterly》1997,5(10):1893-1901
A model sterol-based ion channel was rationally designed and synthesized. The potential ion channel is comprised of a tartrate-derived crown ether to which six steroids are appended. Macromolecule 1a was incorporated into phospholipid vesicles and shown to facilitate the transmembrane transport of sodium and lithium ions using alkali metal NMR spectroscopy. 相似文献
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