Adaptive Capacities of Lymphocytes in Techa Riverside Residents Chronically Exposed to Radiation (original) (raw)
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Journal of Biological Researches
The Mamuju area has recorded a higher than average natural radiation dose compared to other regions in Indonesia. It is possible that inhabitants of Mamuju developed the radioadaptive response (RAR). To prove that the RAR was developed in Mamuju inhabitants, evaluation of lymphocytic radiosensitivity using the G0 micronucleus (MN) assay was conducted herein. The MN frequencies in peripheral blood lymphocytes before and after exposed to 1.5 Gy radiation at a dose rate of 0.38 Gy/min were assessed from 11 samples of Botteng Village, Mamuju inhabitants and control groups. These treated cells were then cultured and exposed to cytochalasin-B to arrest cells during the cytokinesis stage. The mean number of MN induced by radiation per 1000 binucleated cells (BNC) was evaluated for both Mamuju inhabitants and control groups. The lymphocytic radiosensitivity was calculated using standard deviation (SD) of the mean value (MV) of the number of MN induced by radiation found in the control group. Based on the SD and MV values, individual lymphocytes were classified as ''resistant'', ''sensitive'', or ''normal'' if the mean of MN induced by radiation was ≤ MV-(2×SD), ≥ MV + (2×SD) or in between, respectively. The results showed that lymphocytes from six samples in Botteng Village inhabitants were categorized as resistant and five samples were normal. In contrast, all samples in the control group were demonstrated to have normal sensitivities. The study results also revealed that lymphocytic radiosensitivity was not correlated with age and gender, which was probably because of the small sample size used in this study. Further investigation with a larger sample number and higher radiation dose should be conducted to validate our findings.
2018
An evaluation on the cytogenetic and DNA damages caused by natural radiation was done in eighty eight person living in Botteng village as HLNRA and their matched control in Keang village as normal level natural radiation areas (NLNRA). Their bloods were collected with their full informed consent and culture set up for cytogenetic evaluation as well as nucleic acid damage observation with comet assay and γ -H2AX that were done according to the standard procedures. Lymphocytes were scored manually under microscopic observation for the presence of chromosome aberrations. Radiosensitivity of cells evaluation was also done by challenging these bloods to 1.5 Gy of gamma rays before being cultured. The evaluation showed that frequency of chromosome aberration in HLNRA group was lower (0.00081) compared to control group (0.00125). However, frequency of micronucleus (MN) in HLNRA group was higher (0.0204) than that in control area (0.0172). Nucleoplasmic bridge and nuclear budding are found ...
Mutagenesis, 1998
Human lymphocytes pre-exposed to very low doses of ionizing radiation show an adaptive response, which make these cells less sensitive to subsequent higher exposures. To verify the hypothesis that a similar phenomenon can be induced by occupationally (in vivo) received doses of ionizing radiation, the cytogenetic responses of 24 medical radiation workers to 1 and 2 Gy y-irradiation in comparison with 13 non-exposed individuals have been studied. Cytokinesis-blocked micronucleus assay of lymphocytes revealed that although the frequencies of spontaneous micronuclei in radiation workers are more than non-exposed individuals, after 1 and 2 Gy in vitro irradiation of lymphocytes this frequency was found to be lower for radiation workers. The results suggest the existence of an in vivo adaptive response in individuals chronically exposed to low dose radiation. The observation of radioresistance to higher doses of radiation in pre-exposed lymphocytes might be due to initial DNA damage and an induced DNA repair mechanism.
2019
The Mamuju area has recorded a higher than average natural radiation dose compared to other regions in Indonesia. It is possible that inhabitants of Mamuju developed the radioadaptive response (RAR). To prove that the RAR was developed in Mamuju inhabitants, evaluation of lymphocytic radiosensitivity using the G0 micronucleus (MN) assay was conducted herein. The MN frequencies in peripheral blood lymphocytes before and after exposed to 1.5 Gy radiation at a dose rate of 0.38 Gy/min were assessed from 11 samples of Botteng Village, Mamuju inhabitants and control groups. These treated cells were then cultured and exposed to cytochalasin-B to arrest cells during the cytokinesis stage. The mean number of MN induced by radiation per 1000 binucleated cells (BNC) was evaluated for both Mamuju inhabitants and control groups. The lymphocytic radiosensitivity was calculated using standard deviation (SD) of the mean value (MV) of the number of MN induced by radiation found in the control group...
Environmental …, 2007
The aim of the present study was to perform a cytogenetic analysis in peripheral lymphocytes of 36 individuals occupationally exposed to low levels of ionizing radiation, and compare the results with 36 controls, using the chromosomal aberrations test (CA), sensitivity to bleomycin and cytokinesis-blocked micronucleus assay (MN). The frequencies of CA/100 cells observed for the exposed workers were not significantly higher than in controls (P > 0.05). The mean break/cell (b/c) for the controls and exposed workers was 0.59 ± 0.39 and 0.57 ± 0.29, respectively (P > 0.01). The MN frequencies were significantly increased (P < 0.01) in exposed workers (6.13 ± 3.18) in comparison with controls (5.11 ± 3.85). The mean MN was also statistically higher in the non-smoker exposed when compared with non-smoker controls, 5.80 ± 3.09 and 5.15 ± 4.08, respectively (P < 0.01). The cytogenetic analysis of MN proved to be the most sensitive biological marker to assess the cellular response to low levels of irradiation.
2015
Iran is one of several countries that has regions of high dose natural ionizing radiation. Two wellknown villages in the suburb of Ramsar Town in the Caspian Sea strip, Taleshmahaleh and Chaparsar, have background radiation that is 13 times higher than normal. This radiation is the result of Radium 226 and Radon gas both of which are highly water soluble. While people living in these regions do not suffer from any major health problems, we decided to study the their immune responses to infection and inflammation in order to determine if their habitat affects their immune defense mechanisms as a way of compensating for their exposure to high dose environmental ionizing radiation. Our results showed that the total serum antioxidant level in the exposed people was significantly lower than the individuals not exposed to high dose natural ionizing radiation. The exposed individuals also had higher lymphocyte-induced IL-4 and IL-10 production, and lower IL-2 and IFN-γ production. In addition, neutrophil NBT, phagocytosis, and locomotion were higher in the exposed group. In contrast, lymphocyte proliferation in response to PHA was unaffected. We conclude that the immune system of individuals exposed to high dose ionizing radiation has adapted to its environment by shifting from a Type 1 to a Type 2 response to promote antiinflammation. This may be because inflammatory Type 1 responses generate more free radicals than Type 2 responses, in addition to the free radicals generated as a result of high environmental radiation. Thus, the serum total antioxidant level in the exposed residents was lower than the unexposed group.