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Showing 9 results for Chromosomal Aberration
S.m.j. Mortazavi, T. Ikushima, H. Mozdarani,
Volume 1, Issue 1 (6-2003)
Abstract
Background : There are growing evidences for chromosomal radioadaptive response in human lymphocytes . Highly variable inter- and intra-individual responses have been reported. Some individuals are non-responders and even in some donors the frequency of chromatid aberrations induced by a challenge dose increases by pre-exposure to an adapting dose. It has been proposed that the lack of radioadaptive response is due to transient physiological factors. Materials and Methods : We found a young healthy donor who exhibited no radioadaptive response in our initial experiments. After a common adapting dose, the donor occasionally showed a highly increased susceptibility to subsequent high-dose irradiation. To assess whether the lack of radioadaptive response and the induction of a synergistic effect are transient responses , we have performed a 3-year follow-up study employing micronuclei in binucleated cells besides chromatid aberrations as biological endpoints. To eliminate the effect of the cell cycle on intrinsic radiosensitivity of a cell, we used the multiple-fixation regimen for analysis of chromosomal aberrations. Results : This donor showed no adaptive response in any experiment. Conclusion : Considering the consistent non-responsiveness observed throughout our serial experiments, it may be concluded that the lack of radioadaptive response is not attributed to some transient physiological factors but rather to permanent constitutional traits. Iran. J. Radiat. Res., 2003 1(1): 55 - 61.
F. Farhan, A. Kazemian, H. Alagheband,
Volume 1, Issue 2 (9-2003)
Abstract
Background: Radioprotective capability of histamine H2 receptor antagonists have been shown in several in vivo studies mainly using animal models. However, to verify the effectiveness of these agents in clinical applications, studies should be performed on human cells. In the present study radioprotective properties of these agents was examined in vitro on human lymphocytes using metaphase analysis. Materials and Methods : In vitro metaphase analysis technique was used to test the effects of cimetidine, ranitidine and famotidine on radiation induced clastogenic effects. Lymphocytes in whole peripheral blood were exposed to 3 Gy gamma-rays at a dose rate of 73.7 cGy/min in the presence or absence of various doses of the drugs used in this study. The frequency of chromosomal aberrations were determined after standard metaphase preparations and staining slides in 5% Giemsa. Results: Results show that radiation produced a high number of chromosomal aberrations in lymphocytes compared to controls (p<0.001). All three drugs used in this study effectively reduced the frequency of chromosomal aberrations at all doses. Famotidine was found to be more effective than the other two drugs. Conclusion: From the results obtained it can be concluded that H 2 -receptor antagonists used in this study effectively reduced the clastogenic effects of radiation with a dose reduction factor (DRF) of 1.5-2 in human lymphocytes in vitro. The way in which these drugs reduce the clastogenic effects of radiation might be via radical scavenging mechanism. Iran . J. Radiat. Res. 2003 1(2): 99 – 104.
H. Samavat, M. R. D. Seaward, D. H. Gonzales, Gh. Azizian,
Volume 1, Issue 4 (3-2004)
Abstract
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. Iran . J. Radiat. Res., 2004 1(4): 195-198
D. Fatehi, Dr. H. Mozdarani,
Volume 7, Issue 2 (9-2009)
Abstract
Background: To evaluate the effects of
hyperthermia (HT) on the frequency of chromosomal
aberrations induced by a low dose of neutron or
γ-rays in human peripheral blood lymphocytes.
Materials and Methods: Blood samples were exposed
to HT (41.5°C for 30 and 60min, 43°C for 15 and
30min), 10 cGy neutron or γ-rays, HT + neutron/γ,
and neutron/γ + HT. After standard cell culture,
harvesting, fixation and staining, the chromosomal
damages were scored in metaphase plates. Results:
HT alone at 41.5°C did not induce chromatid or
chromosome aberrations, however, the frequency of
damages was significantly higher at 43°C (P<0.05).
Furthermore, the chromosomal damages was
significantly different when cells were irradiated with
neutron or γ-rays alone (P<0.01). HT 1 hr post
neutron/γ irradiation significantly induced higher
chromosome damages in comparison to HT 1 hr
before irradiation (P<0.05). The chromosomal
damages were remarkably higher when cells
were irradiated with neutron then heated at 43°C for
30 min. Conclusion: Since increasing frequency of
chromosome damages increases probability of cell
death, application of HT after neutron irradiation
(instead of X– or γ- rays) might be considered as a
procedure for cells killing in radiotherapy. Iran. J.
Radiat. Res., 2009 7 (2): 69-77
S.s. Seyyedi, Dr. H. Mozdarani, M. Rezaei Tavirani, S. Heydari,
Volume 8, Issue 1 (6-2010)
Abstract
Background: Rapidly increasing possibilities of
exposure to environmental extremely low-frequency
electromagnetic fields (ELF-EMF) have become a
topic of worldwide investigation. Epidemiological and
laboratory studies suggest that exposure to ELF-EMF
may increase cancer risk therefore assessment of
chromosomal damage in various cell lines might be of
predictive value for future risk estimation. Materials
and Methods: Primary cultures of fibroblasts from
human skin biopsy were exposed to continuous
extremely low-frequency electromagnetic fields (3, 50
and 60 Hz, sinusoidal, 3h, and 4 mT). Also immortalized
cell lines, SW480, MCF-7 and 1321N1 were
exposed to continuous ELF-EMF (50 Hz, sinusoidal, 3
h, 4 mT). Metaphase plates were prepared according
to standard methods and stained in 5% Giemsa
solution. Chromosomal aberrations of both chromosome
and chromatid types were scored to evaluate
the effects of ELF-EMF on primary or established cell
lines. Results: Results indicate that by increasing the
frequency of ELF-EMF, chromosomal aberrations
were increased up to 7-fold above background levels
in primary human fibroblast cells. In addition, continuous
exposure to a 50 Hz electromagnetic field led to
a significant increase in chromosomal aberrations in
SW480, MCF-7 and 1321N1 cell lines compared to
sham control. Conclusion: Results obtained indicate
that ELF-EMF has the potential for induction of
chromosomal aberrations in all cell types. Iran. J.
Radiat. Res., 2010 8 (1): 25-29
Phd. M.m. Ahmed, Z.s. Said, S.a. Montaser, G.a. El-Tawil,
Volume 16, Issue 3 (7-2018)
Abstract
Background: Calcium sennosides are the main active metabolites of sennas, which have a powerful interest to phytochemical and pharmacological research, due to their brilliant medicinal values. It is well known in folk medicine for their laxative and purgative uses. Materials and Methods: This experiment aimed to assess cytogenetic (micronucleus assay and chromosomal aberration study) and biochemical effects of calcium sennosides at a working dose (24 or 48 mg/ ml) on suppressing radiation hazards in human blood cultures. Biochemical investigations include superoxide dismutase (SOD), catalase (CAT), tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), cyclooxygenase-2 (COX-2) and lactate dehydrogenase (LDH) levels. The treatment periods were 48 and 72 hrs post-irradiation at a dose of 3 Gy. Triple blood cultures for each blood sample were set up. Results: Ionizing radiation exposure induced significant increase in micronuclei (MN) frequencies in both mono- and bi- nucleated cells, and all types of chromosome aberrations, beside significant decrease in SOD and CAT activities. While TNF-α, IL-8, COX-2 and LDH levels were significantly increased after irradiation. Treatment with calcium sennosides exhibited decreased of micronuclei and chromosome aberration numbers and enhancement in the level of SOD and CAT activities. In addition, a significant amelioration in IL-8, TNF-α, COX-2 levels and LDH activity were scored. Conclusion: Present results revealed the antimutagenic and the anti-inflammatory effects of sennosides against oxidative stress induced by γ- irradiation.
E. Samei, Ph.d., H. Mozdarani, F. Samiei, G.r. Javadi,
Volume 18, Issue 4 (10-2020)
Abstract
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.
Ph.d., H. Mozdarani, R. Rahbar Parvaneh, S. Mozdarani, M. Lashkari,
Volume 20, Issue 2 (4-2022)
Abstract
Background: There is not yet an appropriate biomarker to predict or follow radiosensitivity of Breast cancer (BC) patients during or after radiotherapy. The aim of this study was to monitor chromosomal aberrations (CA) induced before and during radiotherapy in peripheral blood lymphocytes of BC patients. Materials and Methods: Age-matched twenty normal healthy individuals and 20 invasive ductal BC patients were enrolled in this study. A blood sample was obtained from normal healthy women and BC patients before and after the first, two and four weeks after radiotherapy. Lymphocyte microculture was initiated in 4.5ml complete RPMI-1640 medium. Cells were harvested 50 hours after culture initiation. Cells were harvested based on standard protocols. Hundreds of well-spread mitoses were scored under a light microscope with a magnification of x1000 for various types of CA. Data were statistically analyzed and p<0.05 was considered a significant difference. Results: Results indicated a higher frequency of CA in lymphocytes of un-irradiated BC patients compared to healthy normal individuals, although not statistically significant (p>0.05). High frequencies of CA were observed in lymphocytes of BC patients after radiotherapy, significantly different from the un-irradiated group (p<0.01). The increase in the frequency of CA was increased with increasing radiation dose. Conclusion: Genome instability may contribute to high background and radiation-induced CA in lymphocytes of BC patients. However, there is also the possibility of a radio-adaptation of cells during the course of radiotherapy. Results imply that dicentric chromosomes might be valuable cytogenetic bioindicators to monitor the response of BC patients to radiotherapy.
Y. Li, J. Liu, J. Zhou, B.m. L. Zhang, M.d., X. Li,
Volume 21, Issue 3 (7-2023)
Abstract
Background: We aimed to analyze the value of volume rendering (VR) in diagnosing different solitary pulmonary nodules (SPNs) with diameter less than 1.0 cm and assessing invasion depth in lung adenocarcinoma. Materials and Methods: In total, 908 patients with SPN that was confirmed by postoperative pathology were included, followed by an analysis of the imaging characteristics (including microvascular sign, vascular convergence, lobulation, and spiculation) of malignant and benign SPN based on VR. Moreover, the detection rates of imaging signs of three types of malignant SPNs (pure ground grass nodule, pGGN; part-solid nodule; and solid nodule) classified by SPN density and three invasion depths of adenocarcinoma (pre-invasion lesion, PIL; micro invasive adenocarcinoma, MIA; and invasive adenocarcinoma, IAC) were also analyzed. Results: The microvascular sign detection rate was higher while vascular convergence and spiculation detection rates were lower in malignant SPN than in benign SPN. The microvascular sign possessed high sensitivity (82%) and specificity (72%) in predicting malignant and benign SPNs. The microvascular sign detection rate decreased while vascular convergence, lobulation, and spiculation detection increased with the rising density of malignant SPN. Furthermore, the detection rates of the four imaging signs all increased with the adenocarcinoma invasion depth. Microvascular sign showed good detecting ability in low density SPNs pGGN (81.8%), part-solid nodules (95.8%), and in all three invasion depths of adenocarcinoma (PIL [68.2%], MIS [95.3%], and IAC [87.2%]). Conclusion: These imaging features distinguished by VR exhibited an excellent differential diagnostic ability of various SPNs as well as invasion depth of lung adenocarcinoma.
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