Pre-Exposure to Radiofrequency Electromagnetic Fields and Induction of Radioadaptive Response in Rats Irradiated with High Doses of X-Rays.

Background: Some evidence shows that a pre-exposure to RF can mitigate the effects of subsequent exposures to high doses of ionizing radiation. Objective: We aimed to assess the effect of a pre-exposure to non-ionizing RF radiation on survival, weight changes, food consumption, and water intake of lethally irradiated rats. Material and Methods: In this case-control study, we used a commercial mobile phone (GSM, 900/1800 MHz) as well as a 2.4 GHz Wi-Fi router as the sources of pre-exposure to RF radiation. Forty-eight rats were randomly divided into six groups of control, "8 Gy X-rays", mobile phone, "mobile phone+8 Gy", Wi-Fi, and "Wi-Fi+8 Gy". Then, the survival fraction, weight loss, water, and food consumption changes were compared in different groups. Results: The survival analysis indicated that the survival rates in all of the exposed animals ("8 Gy X-rays", "mobile phone+8 Gy", "Wi-Fi+8 Gy") were significantly lower than the control, "Wi-Fi", and "mobile phone" groups. The changes in survival rates of "mobile+8 Gy", "Wi-Fi+8 Gy", and 8 Gy alone were not statistically significant. However, food and water intake were significantly affected by exposure to both RF pre-exposures and exposure to high dose ionizing radiation. Conclusion: To the best of our knowledge, the existence of a dose window for the induction of AR can be the cause of the lack of AR in our experiment. Our findings confirm that in a similar pattern with the adaptive responses induced by pre-exposure to ionizing radiation, the induction of adaptive response by RF-pre-exposures requires a minimum level of damage to trigger adaptive phenomena.

Combined effect of oral famotidine and cimetidine on the survival of lethally irradiated mice: An in vivo study.

AIMS: The study aims at evaluating the effects of the combinatory famotidine/cimetidine diet on radiated mice's survival. MATERIALS AND METHODS: Two hundred and seventy male mice were categorized into 11 groups, a number of which were comprised of subgroups too. The groups under analysis were posed to varying doses of gamma-radiation, including 6, 7, 8, and 9 Gy, followed by treatments using various drug doses 2, 4, and 8 mg/kg, with survival fractions as long as a month after irradiation being measured and recorded. RESULTS: LD50/30 was calculated as 7.47 Gy for the group with radiation only. Following mouse treatment with a concentration of 4 and 20 mg/kg for famotidine and cimetidine, respectively, the survival fraction for the mice grew significantly compared to LD50/30. The combinatory famotidine/cimetidine diet had a higher dose-reduction factor (DRF) than single doses of the drug in radioprotection. The DRF for combinatory famotidine/cimetidine, famotidine, and cimetidine diets was 08.09, 1.1, and 1.01, respectively. CONCLUSIONS: Results imply that the combined regimen of famotidine + cimetidine in radioprotection had no significant higher DRF than with regimens including each of them separately. In addition, we did not find a synergic effect of combined oral famotidine and cimetidine on irradiated mice.

Combined Effects of Radiofrequency Electromagnetic Fields and X-Ray in Renal Tissue and Function.

PURPOSE: Biochemical and histopathological properties of renal tissues were reported to be affected by both radiofrequency electromagnetic fields (RF-EMF) and ionizing radiation. The radiation-induced changes in the kidney, including the serum levels of blood urea nitrogen (BUN) and creatinine (Cr), could lead to adverse health outcomes such as chronic kidney disease. These complications signify the importance of the research in this field. Thus, in this study, the effects of ionizing and non-ionizing radiations, as well as their combination, were assessed by evaluating the alteration in BUN, Cr, and histopathological changes in kidney tissue. MATERIALS AND METHODS: Ninety-six male Wistar rats were randomly divided into six groups and were exposed to either 900/1800MHz (mobile phone) or 2.4 GHz RF-EMF (Wi-Fi) radiation for 14 days, 8Gy x-ray, or their combination. Sera were collected from 2 mL of rat blood, then BUN and Cr levels were determined. Also, renal samples were stained with hematoxylin and eosin and evaluated histopathologically. RESULTS: Both BUN and Cr levels raised non-significantly after exposure to 8 Gy x-rays. Moreover, all measurements in the samples of x-ray groups were in borderline or higher than normal values. The BUN levels of control, Wi-Fi, x-ray, and Wi-Fi+x-ray groups were not significantly different. However, Cr levels in the Wi-Fi group were significantly higher than those of the controls, and BUN to Cr ratio levels were significantly lower than those of the controls. Also, tubular atrophy and vessel wall thickening were associated with these exposures. CONCLUSION: Exposure to 900/1800MHz, 2400 MHz EMF can alter the kidney function. However, pre-exposure to 900/1800MHz EMF could modulate the acute adverse effects of lethal x-ray dose, which addresses the adaptive response in the kidney.

Assessment of function, histopathological changes, and oxidative stress in liver tissue due to ionizing and non-ionizing radiations.

BACKGROUND: Compared to past decades, humans are exposed to rapidly increasing levels of radiofrequency electromagnetic radiations (RF-EMF). Despite numerous studies, the biological effects of human exposure to different levels of RF-EMF are not fully understood yet. This study aimed to evaluate the bioeffects of exposure to "900/1800 MHz" and "2.4 GHz" RF-EMFs, and x-rays alone as well as their potential interactions, i.e. inducing simple additive, adaptive, or synergistic effects. METHODS: 120 Wistar rats were randomly divided into ten groups of 12 each. The rats were exposed to RF-EMF, 10 cGy, and 8 Gy x-rays, a combination of these exposures, or only sham-exposed. The levels of liver enzymes were determined in serum samples by an auto-analyzer. Moreover, the histopathological changes, and the levels of malondialdehyde (MDA), nitric oxide, ferric reducing antioxidant power, total thiols, and protein carbonyl (PCO) were measured. RESULTS: Among the markers of liver function, gamma-glutamyltransferase was not associated with irradiation but, aspartate transaminase, alanine transaminase, and alkaline phosphatase showed some levels of association. MDA and PCO levels after 8 Gy irradiation increased, but pre-exposure to RF-EMF could modulate their changes. At the cellular level, the frequency of lobular inflammation was associated with the type of intervention. CONCLUSION: The exposure to both ionizing and non-ionizing radiations could alter some liver function tests. A short term pre-exposure to RF-EMF before exposure to an 8 Gy challenging dose of x-rays caused the alterations in oxidative stress markers and liver function tests, which indicate that oxidative stress is possibly involved in the adaptive response.

A study to assess the knowledge and practice of medical professionals on radiation protection in interventional radiology.

OBJECTIVE: Ionizing radiation has been extensively used in medical procedures throughout the world. Such interventional radiological procedures could result in occupational exposure that needs urgent control. Therefore, MPs (medical professionals) should receive education and appropriate training on occupational radiation protection. In this context, the present study is aimed to investigate the MPs' knowledge and practice regarding radiation protection principles during interventional radiological procedures. MATERIAL AND METHODS: A descriptive questionnaire-based study was carried out among 215 MPs involved in interventional fluoroscopy procedures. The practice of 31 MPs was studied using a checklist based on ALARA principles and ICRP guidelines. RESULTS: A total of 43.3% and 45.1% answered correctly for knowledge and practice. However, the difference between radiation protection knowledge and practice between the physicians and nurses was statistically significant. The knowledge and practice survey of MPs demonstrated that nurses rarely adhered to radiation-protection measures. CONCLUSION: The present study reflects the lack of knowledge and practice concerning radiation protection concepts among the nurses. This deficiency needs to be resolved by periodic practical radiation protection courses in the curriculum of medicine.

Chromosomal aberrations in C-arm fluoroscopy, CT-scan, lithotripsy, and digital radiology staff.

We have assessed chromosome-type aberrations and micronuclei in the peripheral lymphocytes of personnel working with C-arm fluoroscopy, multi-slice CT-scan, lithotripsy, and digital radiology medical procedures. The study population comprised of 46 exposed workers and 35 controls matched for age, gender, and other confounding factors. Chromosome-type aberrations and micronuclei were analyzed and compared with occupational dosimetry data. The highest frequency of both chromosome aberrations (1.62 CA/100 cells) and MN (MN = 7.47 ± 2.55) was observed in the operating room group. According to occupational dosimetry, surgeons and medical staff received 0-2.99 mSv over the previous year, well below the limit established by the International Committee on Radiation Protection. An increased level of chromosomal aberrations was observed among workers exposed in the operating rooms. We recommend that operating room radiation safety programs be improved and better supervised, in particular for orthopedic surgeons and personnel performing fluoroscopically guided procedures.

Mizaj as an Index in Persian Traditional Medicine Index Could Associate with Sensitivity to the Radiation.

BACKGROUND: The sensitivity to the radiation among human population depends on various parameters. This variation could lead to dissimilar outcome of radiotherapy in similar situations. Mizaj is a well-known term in Persian medicine that present an individualized medicine viewpoint. All of the people will be categorized in cold, moderate, and warm Mizaj. In this study, we aimed to evaluate the possible association between Mizaj and radiosensitivity by comet assay. MATERIALS AND METHODS: Peripheral blood sample of 30 healthy volunteers (10 cold, 11 moderate and nine warm Mizaj) were taken and divided into two identical parts. The first part was exposed to 4 Gy x-rays, and the second part was regarded as the sham control. Then, DNA damages of samples were evaluated by the neutral comet assay. RESULTS: The results showed that the mean percentage of damaged cells, in all of the irradiated groups including A (warm), B (moderate) and C (cold) was significantly higher than the controls (P<0.001). Moreover, DNA damage rate in the irradiated warm Mizaj group was higher than both cold and moderate irradiated groups, but the difference between moderate and cold irradiated groups was not statistically significant. CONCLUSION: The results are indicating that warm Mizaj persons could be more radiosensitive than other groups, which their importance in radiotherapy individualization should be evaluated in more extensive studies.

The expression of MLH1 and MSH2 genes among inhabitants of high background radiation area of Ramsar, Iran.

Previous studies evidenced the critical role of the mismatch repair system in DNA damage recognition, cell cycle arrest, apoptosis and DNA repair. MLH1 and MSH2 genes belong to repairing complexes of mismatch repair system. The side effects of ionizing radiation on the human health were proved, but researches on the inhabitants of high background radiation areas, with extra-ordinary radiation exposure, showed that the prevalence of cancer or radiation-related diseases is not significantly higher than normal background areas. The city of Ramsar, in northern Iran, has the highest level of natural background radiation in the world and in this study, we aimed to evaluate the expression of MLH1 and MSH2 genes among the inhabitants of high background radiation areas of Ramsar compared to normal background radiation areas. In the present study, 60 blood sample from high and normal background inhabitants were collected and we MLH1, and MSH2 genes expressions in residents of high background radiation area compared with normal background radiation area were evaluated by Quantitative Real-Time PCR. Our results showed a significant upregulation of MLH1 in residents of high background radiation area. Also, there is a significant association between MLH1 and MSH2 gene expression in both sexes. Also, the increased expression of MLH1 in HBRA is notable. There is an increased expression of MLH1 in age above 50 and a decreased expression of MSH2 in ages under 50 years (P < 0.0001). These findings are suggesting the triggering of Mismatch Repair system in response to high-level of natural background radiation.

The assessment of radio-adaptive response in graves' hyperthyroidism patients following radioactive iodine uptake.

Low doses of radiation affect the response of cells to higher doses; this phenomenon is called radio-adaptive response, which leads to increased resistance to subsequent higher doses. We have investigated the adaptive response using 0.37 MBq priming dose of I-131 followed by 296-444 MBq challenging dose in peripheral human lymphocyte cells. The study was performed on 42 patients with Graves' disease and 29 healthy adult persons as a control group. The patients were divided into two groups. In the first group, patients were referred for radioactive iodine therapy with a specific dose, and iodine was given to them on the day of referral. In the second group, patients were referred for radioactive iodine uptake and radioactive iodine therapy, and iodine uptake was initially performed, then 24 h later, iodine therapy was done. In both groups, 1 month after treatment, blood samples were taken to cytokinesis-block micronucleus (MN) assay. The number of MN in binuclear lymphocyte cells was counted as an end point test. The mean frequency of MN in first, second, and control groups was 75.86 ± 12.68, 71.45 ± 12.56, and 20.06 ± 7.30, respectively. Our results showed that the frequency of total chromosome aberration in both radiation groups was higher than controls. However, in the first group was higher than another group, but their difference was not statistically significant. According to the results, we cannot approve the hypothesis that 0.37 MBq I-131 administration before iodine therapy could induce a radio-adaptive response in lymphocytes of Graves' patients.

Radioprotective effect of hesperidin on reducing oxidative stress in the lens tissue of rats.

INTRODUCTION: Oxidative stress is a common factor in cataract. Considering the antioxidant properties of hesperidin as a flavanone glycoside from the flavonoid family with radioprotective effect, this study aimed to determine the protective effect of this flavanone glycoside on reducing oxidative stress in the eye lens tissue of mature rats caused by gamma irradiation. MATERIALS AND METHODS: A total of 48 adult rats were randomly divided into six groups, namely, control, Dimethyl sulfoxide (DMSO), hesperidin, radiation, radiation + DMSO, and radiation + hesperidin. 15 Gy irradiation was carried out using Cobalt-60 teletherapy instrument with a source-to-surface distance of 80 cm at a dose rate of 98.5 cGy/min. 2 days following irradiation, we removed the rats' lenses and analyzed them to determine the effects of hesperidin. RESULTS: The comparison of control and intervention groups after irradiation showed that malondialdehyde (MDA) level in the lens tissue was significantly higher in the irradiation groups than the control group. Furthermore, a significant difference between radiation and radiation + hesperidin groups were observed. The level of glutathione (GSH) in the lens tissue was significantly lower in the irradiation groups compared to the control group. Nonetheless, significant elevation of GSH in the radiation + hesperidin group compared to radiation group was seen. CONCLUSIONS: Radiation exposure reduced GSH and enhanced MDA levels in the lens tissue. However, GSH and MDA levels were modulated after hesperidin consumption. These results show the antioxidative properties of hesperidin in the lens and demonstrated that radiation complications such as cataract can be reduced by hesperidin through reducing oxidative stress.

Radio-adaptive Response in Myocardial Perfusion Imaging Induced by Technetium-99m.

PURPOSE OF THE STUDY: Low dose radiation will induce adaptation and following exposure to an adaptive dose, the cells are more resistance to following challenging doses. This phenomenon is known as radio-adaptive response. The aim of this study was to investigate the percentage of apoptotic cells in the peripheral blood samples of the patients which undergo myocardial perfusion imaging (MPI) with technetium-99m (Tc-99m) before thallium scan to assess the induction of radio-adaptive response. MATERIALS AND METHODS: In this study, 97 samples from 74 patients, referred to nuclear medicine center of Mazandaran Heart Hospital for MPI, which had no history of diagnostic, therapeutic, occupational, and radioactive exposures during past 2 years, were provided. The participants were classified into four groups including control, patients which were scanned solely with technetium, the patients which examined by thallium and the last group were the patients that examined by technetium followed by thallium. Then 2 ml Peripheral blood samples were obtained, and after 24 h incubating, the samples were studied by neutral comet assay. Statistical analysis was carried out using Student's t-test along with one-way analysis of variance. RESULTS: The mean percentage of apoptotic cells in the exposed groups were higher than the control. Furthermore, among exposed groups, the apoptotic cells in thallium group were more than others and this index was significantly lower in the group which was undergone technetium administration before thallium scan. CONCLUSIONS: These findings suggest that exposure to Tc-99m could induce a radio-adaptive response against the exposure of thallium-201.

Radioprotective effect of Zamzam (alkaline) water: A cytogenetic study.

BACKGROUND: Radioprotectors are useful compounds to reduce radiation toxicity of normal cells. Many natural radioprotectors have antioxidant power and display fewer toxicity and side effects than the chemical ones. Alkaline waters such as Zamzam have antioxidant power potentially. This study aimed to investigate the radioprotective effect of Zamzam water in mice bone marrow exposed to gamma radiation by micronuclei test. METHOD: Five study groups including control group which was fed by ordinary water, the second group was fed by Zamzam water, and radiation groups were received 2Gy gamma with ordinary and Zamzam water for 10 days and another for 20 days. The frequency of micronuclei and polychromatic erythrocytes to normochromatic erythrocytes ratio were calculated by micronuclei test. RESULT: In the absence of radiation, no significant difference was found between Zamzam group and control in the number of micronuclei in normochromatic erythrocytes, micronuclei in polychromatic erythrocytes, and the polychromatic erythrocyte to polychromatic erythrocyte plus normochromatic erythrocyte ratio. But all of these indices were significantly different between irradiated and non-irradiated groups. The frequency of micronuclei in polychromatic erythrocytes was not significantly different between 10 and 20 days Zamzam irradiated groups, but the reduction in micronuclei in normochromatic erythrocytes and an increase in the polychromatic erythrocyte to polychromatic erythrocyte plus normochromatic erythrocyte ratio compared to ordinary water were seen in 20 days Zamzam group. Dose reduction factor was 1.36 and 2 for Zamzam water groups of 10 days and 20 days, respectively. CONCLUSION: The results demonstrated that Zamzam alkaline water could reduce clastogenic and cytotoxic effects of gamma irradiation.

Rh factor is associated with individual radiosensitivity: A cytogenetic study.

INTRODUCTION: Radiosensitivity is an inherent trait, associated with a raised reaction to ionizing radiation on the human body. In radiotherapy and radiation protection fields, individualization of the patient's treatment is one of the main topics. With the goal of determining biomarkers capable of anticipating normal tissue side reactions, we studied the association between the Rh factor and radiosensitivity. METHODS: This experimental study was carried out from January to June 2014 among 50 normal responders with A blood group (25Rh+ and 25Rh-) between the ages of 22 and 23 in Babol, Iran. Human peripheral blood samples were taken from subjects and, using CBMN assay, the biological effects of gamma irradiation, including the frequency of micronuclei (MN) and nuclear division index (NDI), were measured. A data analysis was performed using SPSS version 18 to determine the independent and paired samples t-tests. RESULTS: A significant increment occurred in the frequency of MN in group Rh+ (196 ± 18.23) compared with Rh- (169 ± 17.11) following irradiation (p<0.001). CONCLUSIONS: The Rh factor might be a predicting marker in an individual's radiosensitivity to ionizing radiations. However, we believe that additional investigations are needed to prove this hypothesis.

Radiation-induced nausea and vomiting: Is ABO blood group as important as radiation and patient-related factors? An observational study.

Despite the improvements in cancer screening and treatment, it still remains as one of the leading causes of mortality worldwide. Nausea and vomiting as the side effects of different cancer treatment modalities, such as radiotherapy, are multifactorial and could affect the treatment continuation and patient quality of life. Therefore, the aim of this study was to assess the possible linkage between ABO blood groups and radiation-induced nausea and vomiting (RINV), also its incidence and affecting factors.One hundred twenty-eight patients referring to Tohid hospital of Sanandaj, Iran, were selected and the patients and treatment-related factors were determined in a cross-sectional study. Patients' nausea and vomiting were recorded from the onset of treatment until 1 week after treatment accomplishment. Also, previous possible nausea and vomiting were recorded. The frequencies of nausea and vomiting and their peak time were examined during the treatment period.The association between ABO blood group and the incidence of radiotherapy-induced nausea and vomiting (RINV) were significant and it seems that A blood group patients are the most vulnerable individuals to these symptoms. The association between Rhesus antigen and the time of maximum severity of RINV may indicate that Rhesus antigen affects the time of maximum severity of RINV. The incidence of RINV was not affected by karnofsky performance status, but it was related to the severity of RINV. Furthermore, among the factors affecting the incidence of nausea and vomiting, nausea and vomiting during patient's previous chemotherapy, radiotherapy region, and background gastrointestinal disease were shown to be three important factors.In addition to familiar RINV-affecting factors, ABO blood group may play an important role and these results address the needs for further studies with larger sample size.

Is there association between ABO blood group and the risk factors of unfavorable outcomes of pregnancy?

There are four major blood groups in human based on the presence of A and B antigens. ABO gene encodes A and B antigens on the surface of red blood cells and there are reported relations between this blood phenotype and pregnancy outcomes in the women. In this study, medical records of 792 healthy pregnant women were investigated and their age and blood test results including blood group with fasting blood sugar, hemoglobin, hematocrit, urea, creatinine and red blood cell counts were analyzed in statistical package for the social sciences. The RBC count in AB blood type was significantly higher than A and O blood group, also FBS level in the people with AB blood group was meaningfully higher than A group. But the mean of HGB and HCT were not significantly different between groups. The serum urea in the AB group was higher than the three other groups and also it was significantly higher in B compared to O and A blood groups. The serum creatinine in the AB group was higher than the three other groups too. Also it was significantly higher in the B group compared to A blood groups. These results indicate that the ABO blood group may have association with some of the risk factors of the unfavorable outcomes of pregnancy and it may be one of the prognostic tools, also it addresses more extensive studies.

The highest background radiation school in the world and the health status of its students and their offspring.

Although the average effective human dose from natural background radiation is about 2.4 mSv per year, the students of the Saeid Nafisi school in Ramsar received effective doses of about 250 mSv while studying there for over 5 years. The goal of this project was a retrospective study of the health status of former students of this school and their offspring. The list of the students of the Saeid Nafisi school (high background radiation) and Taleghani and Kashani schools (ordinary background radiation) was provided by the Department of Education. After matching sex, age and socioeconomic level and obtaining their consent, part 1 of the specifically designed questionnaire was filled out by interview, and clinical examinations were recorded in part 2 of the questionnaire by a physician. The data were analysed using Statistical Package for the Social Sciences 16. Our study shows that 88.1 % of general examinations of high background radiation school students were normal as compared with 85.7 % for control group. There were no significant differences. This study is interesting and unique. It reveals that there is no health emergency related to these high radiation doses. We recommend continuing the health supervision of this population in the future.

The effects of residence duration in high background radiation areas on immune surveillance.

PURPOSE: The effective dose received by humans from natural sources is about 2.4 mSv y(-1), but this is 10.2 mSv y(-1) for inhabitants of Ramsar, a city in northern Iran. Carcinogenesis is one of the most studied effects of radiation, especially in high doses. Nonetheless carcinogenesis of low doses is uncertain. A recent epidemiological study in high background radiation areas of Ramsar showed that the cancer incidence in this era is lower than neighbors. The reason of this different behavior is under study yet. NK cells, helper, and Cytotoxic T cells are most important components of the tumor immune surveillance. The counts and activities of these cells and also leukocytes, lymphocyte, neutrophil cells, and other important parameters were studied in the residents of Ramsar with different duration of exposure to chronic low dose radiation. MATERIALS AND METHODS: Fifty residents of high background radiation areas, who were between 25 and 35 years and fully healthy, were selected randomly and their consent was obtained. Then, 2 cc fresh peripheral bloods were taken in sterile conditions. Complete blood cell counts were performed by an automatic hematology analyzer and CD4+, CD8+, NK, and CD107a+ cell counts were determined by monoclonal antibodies and flowcytometry. CD4+ and CD8+ percentages and the CD4/CD8 ratio were determined and the data were analyzed using SPSS 16. RESULTS: The percentages of CD4+ cells increase, but the counts of CD107a+ cells decline in higher exposure durations. The other parameters did not have significant regression with exposure duration. CONCLUSIONS: These confirm that living in high background radiation areas may induce changes in the immune system gradually and address more investigations.

The assessment of cytotoxic T cell and natural killer cells activity in residents of high and ordinary background radiation areas of Ramsar-Iran.

The effective radiation dose of human from natural sources is about 2.4 mSv/y and the dose limit for radiation workers is 20 mSv/y. Ramsar, a city in Iran, has been the subject of concern in the last forty years for a high level of radiation measured in some spots as high as 260 mSv/y. Carcinogenesis is one of the most studied effects of radiation especially in high doses. Recent studies showed that the high level of natural radiation received by inhabitants of this area, paradoxically don't have significant health effect. Natural killer (NK) cells and cytotoxic T cells are the most important cells in tumor immune surveillance and CD107a is a widely expressed intracellular protein located in the lysosomal/endosomal membrane. CD107a transiently located on the cell membrane can be used as a marker of CD8 + T cell degranulation following stimulation. It is also expressed, to a lower extent, on activated NK cells. In this study, 60 healthy people were selected randomly and their consent obtained and confounding factors such as sex, age, life-styles was matched then the count of activated NK and CD8 + cells was compared in high and normal background radiation areas inhabitants of Ramsar. After filling the questionnaire and measurement of background radiation, blood samples of 30 healthy people from each region were analyzed immediately by means of flowcytometry. The leukocytes and their subsets were not significantly different between two groups and the count of active cells was higher in control group. The result shows that the changes in immune system occur due to radiation and maybe it is as a result of higher radiosensitivity of activated cells.

The study of radiosensitivity in left handed compared to right handed healthy women.

BACKGROUND: Radiosensitivity is an inheriting trait that mainly depends on genetic factors. it is well known in similar dose of ionizing radiation and identical biological characteristics 9-10 percent of normal population have higher radiation response. Some reports indicate that distribution of breast cancer, immune diseases including autoimmune diseases as example lupus, Myasthenia Gravies and even the rate of allergy are more frequent in left handed individuals compared to right handed individuals. The main goal of the present study is determination of radiosensitivity in left handed compared to right handed in healthy women by cytokinesis blocked micronuclei [CBMN] assay.5 ml peripheral fresh blood sample was taken from 100 healthy women including 60 right handed and 40 left handed. The age of participants was between 20-25 old years and they had been matched by sex. After blood sampling, blood samples were divided to 2 groups including irradiated and non-irradiated lymphocytes that irradiated lymphocytes were exposed to 2 Gy CO-60 Gama rays source then chromosomal aberrations was analyzed by CBMN [Cytokinesis Blocked Micronuclei Assay]. RESULTS: Our results have shown radiosensitivity index [RI] in left-handers compared to right-handers is higher. Furthermore, the mean MN frequency is elevated in irradiated lymphocytes of left-handers in comparison with right-handers. CONCLUSION: Our results from CBMN assay have shown radiosensitivity in the left handed is higher than right handed women but more attempts need to prove this hypothesis.

Is there association between handedness and radiosensitivity in breast cancer women?

Radiosensitivity is a biological response to radiation. This response depends on many factors such as radiation factors as well as biological system factors. It is shown that identical doses of radiation for the treatment of Cancer patients produce different biological responses that are assumed to be depend on different specifications of the biological systems. However, by elimination of these factors, people may still show different biological responses such as acute and low responses to radiotherapy in similar doses of radiation. Some reports indicate that breast cancer, immune diseases including autoimmune diseases such as lupus, Myasthenia Gravies and even the rate of allergy are more frequent in left-handed compared to right-handed individuals. The main goal of the present study is determination of radiosensitivity in left-handed compared to right-handed in breast cancer women by cytogenetic assay. Peripheral venous blood samples (10 ml) of 30 breast cancer women (10 left- and 20 right-handed) were divided into two identical parts. One part is exposed to 2 Gy Co-60 gamma rays, and the second part is considered as non-exposed controls. Lymphocytes were cultured in standard media, and cytokinesis blocked to score micronuclei in bi-nucleated cells. The frequency of micronuclei in 1,000 cells in each sample is considered as the rate of radiosensitivity and was compared in left- and right-handed breast cancer women by appropriate statistical analysis. Results showed that radiosensitivity index in left-handers is higher than right-handers also mean frequency of MN in exposed group of left-handers compare to right-handers is elevated. It seems that left-handed breast cancer women are more radiosensitive than right-handed. More investigations on right- and left-handed healthy people are ongoing in our laboratory.