Leukemia is referred to a group of hetrogenous neoplasia, which results from the hematopoietic cells transformation. Various CHROMOSOMAL abnormalities have been recognized as primary patogenetic changes. Clonal CHROMOSOMAL ABERRATION is found in approximately 80% of childhood acute leukemia. Favourable and poor prognosis karyotypes are evident in such patients. Since cytogenetic play a dominant role in outcome of patients with childhood acute leukemia it is important to associate characteristic cytogenetic with prognostic value in relation to CHROMOSOMAL abnormalities. Cytogenetic analysis from 51 childhood diagnosed patients under the age of 14 has been performed on the basis of G-banding technique. Each pair of chromosome show unique banding pattern. Various CHROMOSOMAL abnormalities were evident in this study, these include; numerical disorders such as: monosomy, trisomy, tetrasomy, pentasomy and pseudodiploidy. Among them monosomies were more prominent than the other aneuploidy. Structural ABERRATIONs such as philadelphia chromosome, gain and loss, inversion and breakage were seen. Each kind of childhood acute leukemia shows different responses to chemotherapy following cytogenetic studies. This finding strongly suggests that, a close association exists between CHROMOSOMAL abnormalities and the prognostic value and prediction of outcome.

Nowadays, researchers work on combination therapy for cancer treatment. This study was performed to find the effect of hyperthermia after neutron irradiation on CHROMOSOMAL ABERRATION frequency in human peripheral blood lymphocytes. Blood samples were irradiated with 10cGy neutron, then they exposed to hyperthermia at 41.5°C for 60 minutes or at 43°C for 30 minutes with a sixty minute time interval. After tissue culture and preparation of slides, CHROMOSOMAL ABERRATIONs were scored during metaphase. The results showed that post-hyperthermia at both 41.5 and 43°C increased CHROMOSOMAL ABERRATION frequency induced by neutron irradiation and it was more remarkable at 43°C (P<0.05). The cause of these effect probably is the inhibitory effect of hyperthermia on repair process of CHROMOSOMAL damages.

Background: Radiotherapy is regarded as a standard treatment modality in breast cancer (BC). Radiation causes cellular damage both in cancer and normal cells by inducing DNA-damage and CHROMOSOMAL ABERRATIONs (CA). Different agents were used for ameliorating effects of radiation, mainly antioxidants such as melatonin. Melatonin shows oncostatic properties on human BC. The aim of this study was to evaluate the modulating effect of melatonin on radiation induced CA in cells irradiated at G2 phase of the cell cycle. Materials and methods: G2 assay was applied on whole peripheral blood lymphocytes received from 10 BC patients and 5 normal controls. Blood culture was initiated in complete culture medium. Four h prior to harvesting, cells were irradiated with 1Gy gamma rays. Pretreatment of samples with melatonin was done 3 h before irradiation. After metaphase preparation and slide making, slides were stained in Giemsa. Hundred well spread metaphases were scored for the presence of chromatid type ABERRATIONs with a microscope at a magnification of × 1000. Result: Results indicated a high and significant frequency of CA both in lymphocytes of normal and breast cancer patient after irradiation; however, the frequency was much more in lymphocytes from BC patients. Pretreatment of samples with melatonin led to a considerable increase in the frequency of ABERRATIONs especially in lymphocytes of BC patient. Conclusion: Results showed that despite having antioxidant property, melatonin led to enhanced frequency of radiation induced CA in lymphocytes of BC patients.

Background: Most of our current understanding of the biological effects of exposure to ionising radiation is based on conventional cytogenetic techniques, which enable us to determine the relationship between CHROMOSOMAL ABERRATION and dose received by radiation workers. However, conventional techniques have numerous limitations and CHROMOSOMAL ABERRATIONs can be easily missed. Since FISH plays an important role in detecting CHROMOSOMAL changes, this method was used to reassess data derived from previous studies employing conventional techniques. Materials and Methods: Two groups of radiographers were the subject of a study on conventional CHROMOSOMAL ABERRATION and fluorescence in situ hybridisation (FISH) for translocation. The first group was chosen following an accidental contamination incident in a nuclear medicine department. The second group was composed of six radiographers working in an X-ray department with a previous record of overdose as recorded by film-badges; these workers had been the subjects of a previous CHROMOSOMAL study. Coded blood samples from 11 radiographers and 11 controls were analysed for CHROMOSOMAL ABERRATION and by FISH for translocation. 200 metaphases from the peripheral blood lymphocytes per subject were analysed to investigate possible frequencies of chromosome and chromatid type ABERRATION and 2000 metaphases per subject were scored in FISH method.Results: There was no significant difference between the radiographers and the control groups in conventional analysis; also there was no significant difference at the 95% level of confidence in FISH analysis. There was no correlation between levels of translocation and total lifetime doses from occupational (according film-badge and TLD) and/or background irradiation. Conclusion: The overall conclusion is that the frequency of CHROMOSOMAL damage in both groups of radiographers did not exceed that of the control group

Imaging by MRI in diagnostic centers has got a wide application; on the other hand, its biological effects, especially its CHROMOSOMAL ABERRATIONs are not completely distinguished. Researches in this area are incomplete and in some cases contradictory. thus, in 1997, the present research was carried out in Tarbiyat Modares University to determine the effects of the MRI fields on CHROMOSOMAL ABERRATION as well as cellcycle process in human peripheral lymphocytes in vitro.This is an experimental study and has been done on 30 blood samples in two sensitive phases of G◦ & G2 of cell cycle with and without the presence of DNA repair inhibitor (ara.c). Exposure conditions were magnetic field intensity: 1.5 Tesla, Rf 63.86 MHZ and exposure Time 30 & 60 minutes. The effects of MRI on the CHROMOSOMAL ABERRATIONs, by the metaphase analysis and the evaluation of the effect on cell cycle via the mitotic index method were assessed.Recorded results showed that the rate of CHROMOSOMAL ABERRATION and mitotic index frequency was, respectively, as follows: in control group in G◦ 0.5% and 9.5%, in G2 0.5% and 2.3%, and in samples under MRI exposure in G◦ 0.5% and 8.5%, in G2 0.5% and 2.56%, in samples along with 100µ, ffiolara-c in G◦ 2.5% and 2.9%, in G2 19% and 0.57%, and in samples under MRI exposure and along with ara-c in G◦ 2.5% and 3.03%, in G2 19.5% and 2%. Mter assessing the results through the X2 test, no significant differences were found between control group and samples under MRI exposure, whereas there was asignificant difference between the control group and the ara-c group and also samples under MRI exposure and ara-c in the both stages of the research (P<0.05).Results obtained from this study indicated that the fields along with MRI, with the aforementioned characteristics on human peripheral lymphocytes in vitro, in neither G◦ nor G2 of cell cycle, even in the presence of DNA repair inhibitor and by doubling the normal time of exposure used in imaging centers didn't influence the frequency of CHROMOSOMAL ABERRATION and cell cycle process.Since a few researches have been done in the are a of MRI biological effects.with high intensity, especially for determining possible later effects, so such studies should be carried out constantly with higher exposure time and intensity on various species of cells.

Introduction: Most of the hematologic malignancies are heterogenous with regard to morphology, immunophenotype, and genetic rearrangements. Multiple recurrent CHROMOSOMAL ABERRATIONs have been identified by conventional cytogenetic analysis, which is now widely recognized as one of the most important diagnostic and prognostic determinants in these patients.Patients and Methods: Bone marrow samples were obtained from 80 patients with different hematologic malignancies. These consisted of 43 CML cases, 27 AML, 9 ALL and 1 MDS. In each case, cells were cultured and conventional cytogenetic analysis was performed.Results: Among the 80 subjects, 53(66%) were abnormal and 27(34%) showed apparently normal karyotype. The various ABERRATIONs in abnormal cases were t(9;22) (q34;q11) in 43 CML (100%), Monosomy Y in 2 CML (4.6%), monosomy 7 in 1 CML (2.4%), trisomy 8 and t(15;17) (q22;q21) in 2 AML case (7.4%), t(8;21) (q22;q22) in 1 AML (3.7%) and complex karyotype in 2 CML, 1 AML , 1 ALL and 1 MDS (6%). Apart from these, some novel CHROMOSOMAL abnormalities were observed in our study population.Conclusion: The difference in the frequency of clonal CHROMOSOMAL ABERRATIONs is probably the result of the applied methods for chromosome preparation and often very poor morphologic chromosome appearance, making the identification of finer structural abnormalities more difficult. Furthermore, ongoing cytogenetic studies are warranted in larger groups of hematologic malignancies to identify newly acquired CHROMOSOMAL ABERRATIONs that may aid in cloning novel genes involved in the neoplastic process, ultimately helping in the development of targeted therapeutic drugs.

Background: Inherent radiosensitivity associated with elevated CHROMOSOMAL ABERRATIONs (CA) was shown in breast cancer (BC) patients at cellular level. Different agents were used to protect cells against adverse effects of ionizing radiation (IR), mainly antioxidants such as vitamins. The aim of this study was to evaluate the modulating effect of saffron extract on radiation induced CA in lymphocytes of normal individuals and BC patients. Materials and Methods: G2 assay was applied on whole peripheral blood lymphocytes received from 5 normal controls and 10 BC patients with luminal A subtype. Blood culture was initiated in complete culture medium, 4h prior to harvesting cells were irradiated with 1 and 2 Gy X-rays. Pretreatment of samples with saffron was done 2 h before irradiation. After metaphase preparation and slide making, slides were stained in Giemsa. Hundred well spread metaphases were scored for presence of chromatid type ABERRATIONs with a microscope at a magnification of 1000×. Result: Results indicated a high and significant frequency of CA both in lymphocytes of normal and BC patient after irradiation. Pretreatment of samples with saffron led to a significant increase in the frequency of breaks in lymphocytes of both normal individuals and BC patients. Conclusion: Results indicate that despite its antioxidant property, pretreatment of lymphocytes of normal individuals and BC patients with saffron before X-irradiation led to radiosentisizing effect. The way saffron sensitize lymphocytes to X-rays is not known, but it might be possible to inhibit repair of radiation induced DNA strand breaks.

Background: Although radioiodine-131 (131I) has been widely used for the treatment of Graves' disease (GD), radiation is a potential risk factor for mutagenic abnormalities. This retrospective clinical study mainly aimed to investigate the influence of maternal exposure to 131I used for the treatment of GD prior to pregnancy on CHROMOSOMAL ABERRATION and intellectual development of offspring in China. Materials and Methods: In total, 69 children whose mothers received 131I for the treatment of GD during childbearing age were included. Data on the obstetric history, medical records, and the birth characteristics of the children were obtained. The thyroid function, thyroid ultrasound, CHROMOSOMAL structure, and somatic and intellectual development of the children were measured. Results: In all 66 women, the range of the administered 131I was within 228. 2 ±,70. 3 MBq. The height and weight of all children were within the normal ranges, and one child was confirmed as having subclinical hypothyroidism. Two children were diagnosed with benign thyroid nodules, one child was diagnosed with thyroid cysts, and one child was confirmed as having several anechoic areas in both lobes of the thyroid gland. CHROMOSOMAL ABERRATION was observed in one child. None of the children showed any abnormalities in somatic and/or intellectual development. Conclusion: This is the first study to confirm that 131I used for the treatment of GD prior to pregnancy does not significantly increase the risk of CHROMOSOMAL ABERRATION or impair the intellectual development of offspring.

Many biological effects of exposure to extremely low frequency electromagnetic fields (ELF-EMFs) have been documented, but little work carried out on plants. A meiotic study was performed on Brassica napus L as C3 plant and Zea mays L as a C4 plant exposed to electromagnetic fields. Our investigations were focused on plants grown from wet pretreated seeds with 3 and 10 mT for a 4 h exposure time and compared with the control plants of maize. Also our investigation used plants grown from dry pretreated seeds with 10 mT for 4 h, wet pretreated seeds with 10 mT for 2 h, and a control line of canola. A significant difference was observed for meiotic characters studied among treatments. In canola the mean value of total, terminal, and intercalary chiasmata reduced significantly in plants grown from exposed seeds, indicating that EMFs caused reduction in the mean value of the genetic recombination. Other meiotic characteristics including ring bivalent and quadrivalent formation reduced significantly as well. In maize the mean value of total, terminal and intercalary chiasmata changed significantly in the plants grown from exposed seeds to 3 mT intensity, indicating increase in genetic recombination. Moreover, formation of ring bivalent and quadrivalent increased significantly.All results suggested these plants react differently in some aspects against EMFs as abiotic stress.