Current cytogenetic methods for detecting exposure and effects of mutagens and carcinogens.

Abstract

Most mutagens and genotoxic carcinogens are efficient inducers of chromosomal alterations in exposed cells. Two important classes of aberrations, namely structural and numerical, are recognized and both types of aberrations are associated with congenital abnormalities and neoplasia in humans. These alterations can be easily detected and quantified in human peripheral blood lymphocytes. Conventional staining techniques can be used to detect these aberrations; this technique was used to estimate absorbed dose in the case of a radiation accident in Goiania, Brazil. A recently introduced fluorescent in situ hybridization technique (FISH) using DNA probes has increased the sensitivity and ease of detecting chromosome aberrations, especially stable chromosome aberrations. This technique allows, to some extent, the estimation of absorbed radiation dose from past exposures. Numerical aberrations can be directly estimated in metaphases by counting the number of FISH-painted chromosomes. Micronuclei are formed by lagging chromosome fragments or whole chromosomes during the anaphase stage of cell division. The nature of micronuclei as to whether they possess a centromere can be determined either by CREST staining (calcinosis, Raynoud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia) or FISH with centromere-specific DNA probes. In several carcinogenexposed populations, such as heavy smokers or people exposed to arsenic, aneuploidy appears to be more common than structural aberrations. In victims of radiation accidents, aneuploidy (hyperploidy) has been found to be common in addition to structural aberrations. -Environ Health Perspect 1 04(Suppl 3): 445-448 (1996)

Age-related changes in radiation-induced micronuclei among healthy adults

“…However, the in vitro micronucleus test is also suitable for the evaluation of genotoxicity (1)(2)(3)(4)(5)(6)(7) and is applied to human biomonitoring (8,9). Since radiationinduced micronuclei show a clear dependence on radiation dose and its quality (10)(11)(12)(13)(14), the micronucleus assay can be applied as a biological dosimeter.…”

Antineoplastic Drugs as a Potential Risk Factor in Occupational Settings: Mechanisms of Action at the Cell Level, Genotoxic Effects, and Their Detection Using Different Biomarkers

“…Stanice se 48 sati uzgajaju u uvjetima in vitro, nakon čega se pristupa izradi mikroskopskih preparata koji se pregledavaju pod svjetlosnim mikroskopom (slika 5b). Obično se analizira 100 do 200 metafaza prve diobe in vitro te utvrđuje ukupan broj i vrste oštećenja na kromosomima (146)(147)(148).…”

“…Stabilne aberacije su uravnotežene translokacije, inverzije i drugi simetrični rearanžmani koji se diobom mogu prenijeti u stanice kćeri. Mogu se detektirati samo posebnim tehnikama bojenja kromosoma (metode pruganja, FISH) (121,146).…”

Mechanisms involved in the induction of aneuploidy: the significance of chromosome loss

“…Fluorescence in situ hybridization with probes for entire chromosomes was recently used (van Diemen et al, 1995;Dulout et al, 1996;Natarajan et al, 1996). Staining kinetochores in the cytokinesis-blocked micronucleus assay (Eastmond and Tucker, 1989;Lynch and Parry, 1993;Kirsch-Volders et al, 1997;Thompson and Perry, 1988) or in situ hybridization with centromere specific DNA probes, followed by immunofluorescent staining (Eastmond and Pinkel, 1990;Farooqi et al, 1993) are useful to discriminate between clastogens and aneuploidogens.…”