Ethylene oxide (EtO) is a potent DNA-alkylating agent which has been shown to induce sister chromatid exchanges (SCE) in the peripheral blood lymphocytes of exposed workers. To study further the persistence of EtO-induced SCE, we have examined lymphocytes from a group of cynomolgus monkeys exposed to EtO in control, 50-ppm, and 100-ppm concentrations for 7 h/day, 5 days/week over the years 1979...

To investigate the usefulness of sister chromatid exchange (SCE) analysis in lymphocytes as an indicator for mutagenic effects after in vivo exposure to hexavalent chromium (Cr), SCE frequency was analysed in lymphocytes of 44 Cr platers occupationally exposed to hexavalent Cr and 47 controls. Although urinary Cr analysis confirmed that the Cr platers were exposed to Cr, no effects of the expos...

The aim of the present study was to explore the in vivo mechanism of sister-chromatid exchange (SCE) induction by 5-azacytidine (5-azaC) in murine bone marrow cells. Experiments were performed to examine SCE induction in response to different doses of 5-azaC as well as several exposures. Additionally, we examined the persistence of SCE induction and the effect of bromodeoxiuridine (BrdU) incorp...

The relationship between the 'spontaneous' frequency of sister-chromatid exchanges (SCE) and tumorigenicity was studied in a series of hybrids between a C57BL melanoma cell line and diploid cells, but no correlation was found between the 2 variables. Hybrids in which malignancy was suppressed and malignant segregants derived from them showed virtually identical SCE frequencies. Variation of SCE...

In a previous study, we observed a bimodal distribution of sensitivity to sister chromatid exchange (SCE) induction by diepoxybutane (DEB) in lymphocytes from healthy individuals. Twenty-four % of the participants had increased sensitivity to in vitro induction of SCEs and chromosomal aberrations. These same participants also had significantly higher frequencies of uninduced or baseline SCE fre...

Subcutaneous emphysema (SCE) is a possible complication of both nonsurgical and surgical endodontic treatment. A review of the literature pertinent to endodontic intervention and SCE is highlighted, while the causes of and recommendations for the prevention of SCE are provided. A review of the pathways whereby compressed air may travel through potential spaces in the head and neck is also illus...

The role of side-chain entropy (SCE) in protein folding has long been speculated about but is still not fully understood. Utilizing a newly developed Monte Carlo method, we conducted a systematic investigation of how the SCE relates to the size of the protein and how it differs among a protein's X-ray, NMR, and decoy structures. We estimated the SCE for a set of 675 nonhomologous proteins, and ...