['Attachment', '1!', '71', ';', ';', 'HUMAN', 'URINE', 'MUTAGENICITY', 'STUOY.', 'COMPARING.', 'CIG*RETTES', 'WHICH:', 'BURN', 'OR', 'ONLY', 'HEAT', 'TOBACCO.', 'D.J.', 'Doolittle,', 'C.A.', 'Rahn*,', '$.C.', 'McKarns,', 'G.~.', 'Burger*', 'and', 'A.W.', 'Hayes*.', 'R.J.', 'Reynolds', 'Tobacco', 'Company,', 'Winston-Salem,', 'N.C.', 'The', 'objective', 'of', 'this', 'study', 'was', 'to', 'determ‘ne', 'if', 'consumption', 'of', 'cigarettes', 'which', 'only', 'heated', 'tobacco:', 'would', 'affect', 'urinary', 'mutzgenicity', 'differently', 'than', 'consumption', 'of', 'cigarettes', 'which', 'burned', 'tobacco.', 'Forty-c-2', '(41)', 'non-smokers', 'and', 'thirty-one', '(31)', 'regular', 'cigarette', 'smokers', 'were', 'enrolled', 'in', 't-2', 'six-week', 'study.', 'In:', 'order', 'to', 'control', '---', 'for', 'the', 'influence', 'of', 'diet,', 'subjects', 'were', "plezed'cn", 'an.', 'identical', 'diet', 'andiall', 'food', 'consumed', 'by', 'the', 'subjects', 'during', 'the', '42-day', 'study', '«as', 'prepared', 'and', 'served!', 'to', 'them:', 'by', 'the', 'RJR', 'cafeteria.', 'During', 'the', 'finst', 'week', 'of', 'the', 'study,', 'all', 'smokers', 'consumed', 'an', 'identical', 'cigarette', 'which', 'turns', 'tobacco', '(reference).', 'On', 'week', '2,', 'half', 'of', 'the', 'smokers', 'were', 'switched', 'to:', 'a', 'cigarett2', 'which', 'does', 'not', 'surn', 'tobacco', '(test),', 'while', 'the', 'other', 'smokers', 'remained', 'on', 'the', 'refarence', 'cigarette.', 'On', 'week', 'four,', '.the', 'smokers', 'consuming', 'the', 'test', 'cigarette', 'were', 'switched', 'back', 'to', 'the', 'reference', 'and', 'those', 'consuming', 'the', 'reference', 'began', 'smoking', 'the', 'test', 'cigarette.', 'On', 'week', 'six,', 'all', 'smokers', 'consumed', 'the', 'reference', 'cigarette.', 'Twenty-four', 'hr.', 'urine', 'samples', 'were', 'collected!', 'twice', 'a', 'week,', 'concentrated', 'using', 'XAO-2', 'resin:', 'and', "assayed'", 'fir', 'mutagenicity', 'in.', 'Ames', 'strains', 'TA98', 'and', 'TA1OO.', '“Mutagenicity', 'testing', 'was', 'done', 'with:', 'e-4', 'without', 'metabolic', 'activation;', 'and', 'with', 'and', 'without', "8-glucuronidase/aryl'", 'sulfatzse.', 'The', 'results', 'indicate', 'that', 'when', 'smokers', 'consumed', 'the', 'reference:', 'cigarette', 'the.', 'excreted', 'urine', 'which', 'was', 'more', 'mutagenic', 'than', 'that', 'excreted', 'by', 'the', 'non-smokzrs,', 'buti', 'when', 'consuming', 'the', 'testi', 'cigarette', 'they', 'excreted', 'urine', 'that', 'had', 'mutageric', 'ectivity', 'similar', 'to', 'urine', 'excreted', 'by', 'non-smokers.', 'oe', ',', '138', 'THE', 'ROLE', 'OF', 'OXYGEN', 'FREE', 'RADICALS', 'IN', 'THE', 'INDUCTION', 'OF', 'SISTER', 'CHROMATID.', 'EXCHANGES', 'BY', 'CIGARETTE', 'SMOKE.', 'C.K.', 'Lee,', 'B.G.', 'Brown*,', 'W.Y.', 'Rice*,', 'Jr.,', 'D.J.', 'Doolittle,', 'R.J:', 'Reynolds', 'Tobacco', 'Company.', 'Winston-Salem,', 'NiC.', '27102', 'Cigarette', 'smoke.', 'has', 'bean', 'reported', 'to', 'contain', 'free', 'radicals', 'in', 'both', 'the', 'gas', 'and', '“particulate', 'phases.', 'Studies', 'in', 'our', 'laboratory,', 'have', 'shawn', 'that', 'both', 'cigarette', 'smoke', 'condensate', '(CSC)', 'and', 'smoxe', 'trapped', 'in', 'phosphate', 'buffered', 'saline', '(smake-PBS)', 'increased', 'sister', 'chromatid', 'exchanges', '(SCE)', 'in', 'Chinese', 'Hamster', 'Ovary', '(CHO)', 'cells.', 'Since', 'other', 'researchers', 'have', 'shown', 'that', 'oxygen', 'free', 'radicals', 'can', 'increase', 'SCEs', 'in', '-', 'CHO', 'cells,', 'we', 'investigated', 'the', 'role', 'of', 'oxygen', 'firee', 'radicals', 'in', 'the', 'induction', 'of', 'SCEs', 'by', 'CSC', 'and', 'smoxe-Fi§.', 'The', 'experimental', 'results', 'indicate', 'that.', 'the', 'addition', 'of', 'osygen', 'radical', 'scavengers', 'such', 'as', 'catalase,', 'superoxide', 'dismutase', '(SOD),', 'and', 'ascorbic', 'acid', 'failed', 'to', 'reduce', 't-2', 'SCE', 'frequency', 'in', 'the', 'presence', 'of', 'either', 'CSC', 'or', 'smoke-PBS.', 'Analysis', 'of', 'CSC', 'ars:', 'smoke-PBS', 'indicate', 'that', 'the', 'quantity.', 'of', 'hydrogen', 'peroxide', 'produced', 'fron', 'thes', 'sources', 'is', 'too', 'small', 'to', 'account.', 'for', 'the', 'SCE', 'induction', 'under', 'the', 'experiment::', 'ccnd*', 'tons.', 'It', 'appears,', 'therefore,', 'that', 'SCE', 'induction:', 'by,', 'CSC', 'or', 'smoke-PBS', 'cces', 'noz', '‘avolve', 'the', 'participation', 'of', 'oxygen', 'free', 'radicals.', 'T9IZEEZTO0Z%']