['e', 'Mutagens', 'in', 'sidestream', 'and', 'mainstream', 'smokes', 'Currently', 'the', 'Ames', 'test', 'is', 'being', 'used', 'to', 'investigate', 'the', 'mutagenicity', 'of', 'various', 'smoke', 'fractions', 'in', 'an', 'attempt', 'to', 'determine', 'which', 'fractions', 'process', 'high', 'mutagenicity.', 'The', 'fractionation', 'scheme', 'is', 'that', 'used', 'in', 'our', 'smoke', 'comparison', 'work.', 'This', 'study', 'needs', 'to', 'be', 'expanded', 'to', 'include', 'testing', 'with', 'the', 'battery', 'of', 'tests', 'discussed', 'previously.', 'The', 'current', 'fractionation', 'scheme', 'is', 'not', 'suitable', 'for', 'biological', 'testing', 'and', 'should', 'be', 'modified', 'or', 'replaced.', 'Alternate', 'methods', 'are', 'described', 'in', 'the', 'literature', 'that', 'are', 'more', 'appropriate', 'for', 'use', 'in', 'biological', 'studies.', 'A', 'chemist', 'is', 'needed', 'to', 'prepare', 'and', 'analyze', 'the', 'fractions.', 'Numerous', 'animal', 'studies', 'have', 'been', 'conducted', 'with', 'total', 'particulate', 'matter', 'and', 'smoke', 'fractions;', 'comparison', 'of', 'these', 'data', 'with', 'those', 'from', 'short-term', 'genotoxicity', 'studies', 'will', 'provide', 'useful', 'information.', 'Additionally,', 'studies', 'on', 'each', 'fraction', 'and', 'their', 'interaction', 'will', 'provide', 'information', 'not', 'only', 'on', 'the', 'mutagenicity', 'of', 'each', 'fraction', 'but', 'also', 'on', 'the', 'synergistic', 'or', 'antimutagenic', 'properties', 'of', 'each', 'fraction.', 'There', 'are', 'compounds', 'known', 'which', 'inhibit', 'the', 'mutagenicity', 'and/or', 'carcinogenicity', 'of', 'known', 'mutagens', 'and/or', 'carcinogens.', 'The', 'effect', 'of', 'such', 'inhibitors', 'on', 'smoke', 'mutagenicity', 'should', 'be', 'studied', 'and', 'also', 'an', 'attempt', 'made', 'to', 'define', 'the', 'mechanism', 'of', 'inhibition.', 'This', 'work', 'may', 'lead', 'to', 'the', 'discovery', 'of', 'some', 'compound(s)', 'effective', 'in', 'reducing', 'or', 'eliminating', 'the', 'mutagenicity', 'of', 'tobacco', 'smoke.', 'A', 'toxicologist', 'would', 'be', 'an', 'asset', 'in', 'this', 'type', 'of', 'program.', 'The', 'first', 'body', 'fluid', 'contacted', 'by', 'cigarette', 'smoke', '(or', 'during', 'tobacco)', 'is', 'saliva.', 'It', 'is', 'reported', 'that', 'saliva', 'inhibits', 'the', 'action', 'of', 'some', 'mMutagens,', 'but', 'this', 'has', 'only', 'been', 'demonstrated', 'with', 'the', 'Ames', 'test.', 'Further', 'study', 'is', 'needed', 'with', 'the', 'battery', 'of', 'in', 'vitro', 'tests', 'to', 'confirm', 'this', 'and', 'to', 'learn', 'more', 'about', 'mammalian', 'defense', 'mechanisms.', '@', 'Tobacco', 'additives', 'Considerable', 'work', 'has', 'been', 'done', 'in-house', 'to', 'show', 'our', 'additives', 'are', 'nommutagenic.', 'Most', 'of', 'those', 'tested', 'to', 'date', 'by', 'the', 'Ames', 'method', 'are', 'indeed', 'nonmutagenic;', 'a', 'few', 'have', 'shown', 'slightly', 'positive', 'mutagenicity.', 'Such', 'materials', 'need', 'be', 'examined', 'in', 'the', 'battery', 'of', 'tests', 'described', 'previously.', '6eSZ', '#St0OS']