[Human lymphocyte chromosome changes induced by x-rays]
Monika Bellorín-Fernández1, Janice Fernández-D'Pool
1Instituto de Medicina del Trabajo e Higiene Industrial, Facultad de Medicina, Universidad del Zulia, Maracaibo, Venezuela.
Abstract:
With the aim of determine and characterize chromosomal alterations in human lymphocytes induced by x-rays, an experimental study was performed with auto-control in four healthy donors (two males and two females). Peripheral blood was drawn, and divided in six aliquots: five of them were irradiated with 0.5, 1, 2, 3 and 4 Gy using a linear accelerator and one aliquot was used as control for each donor. The chromosomal analysis was carried out with the "G banding technique". It was observed that as the irradiation doses were raised, the abnormal metaphases and frequency of chromosomal alterations increased as well. The majority of chromosomal alterations were of the structural type, of which the most relevant ones were translocations, fragile sites and deletions. A significant difference was observed between the exposed and non-exposed groups with regard to the irradiation doses and the apparition of chromosomal alterations (p < 0.05). Chromosome 1 was more frequently involved in structural chromosomal alterations, followed by chromosomes 3, 10, 6, 7 and 9. The results presented in this study indicate that chromosomal alterations induced by acute exposure to x-rays increase linearly once the irradiation doses are raised. Therefore, the cytogenetic analysis can be considered as a useful tool for the control of the absorbed radiation dose and its biologicals effects in men.
Related Concept Videos
Inheritance of Chromatin Structures
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Mutations
Heterochromatin
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Chromatin Modification in iPS Cells
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...


