The purpose of this study was to determine if periph-ished infected children and 1.0‰ in well-nourished eral blood lymphocytes from malnourished children infected children. In MMC-exposed cultures the with gastrointestinal or respiratory bacterial infec-mean induced micronucleus frequency was 32.6 { tion show increased frequencies of Mitomycin C 6.1 vs. 12.9 { 2.3; 68.6 { 12.1 vs. 21.0 { 5.1, (MMC)-induced micronuclei as compared to well-and 88.1 { 16.2 vs. 41.7 { 5.0 for malnourished nourished, infected children. The results indicate and well-nourished children at 20, 40, and 60 ng/ that cells from malnourished, infected children had ml MMC, respectively. The number of binucleated greater chromosome damage. This may indicate cells with more than one micronucleus was also that such children would be more susceptible to en-higher in malnourished, infected children at all vironmental damage and malignant transformation. doses tested, including cells with two micronuclei Micronucleus frequencies were analyzed in binu-in MMC-free cultures from malnourished, infected cleate cells produced by the cytokinesis block children. This increase was not found in peripheral method; the overall micronucleus frequency was sig-blood lymphocytes from well-nourished infected nificantly higher in binucleate cells from malnour-children. Environ. Mol. Mutagen. 30:363 -370, ished, infected children. The mean micronucleus fre-1997 ᭧ 1997 Wiley-Liss, Inc. quency in MMC-free cultures was 4.3‰ in malnour-