CT radiomics analysis of primary colon cancer patients with or without liver metastases: a correlative study with [18F]FDG PET uptake values.

PURPOSE: Utilizing [18F]Fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography ([18F]FDG PET/CT) scans on primary colon cancer (CC) patients including with liver metastases (LM), we aimed to determine the relationship between structural CT radiomic features and metabolic PET standard uptake value (SUV) in these patients. MATERIAL AND METHOD: A retrospective analysis was performed on 60 patients with primary CC, of which 40 had liver metastases that were more than 2 cm in diameter. [18F]FDG PET/CT was used to calculate SUVmax, and 42 CT radiomic characteristics were extracted from non-enhanced CT images. Tumors were manually segmented on fused PET/CT scans by two experienced nuclear medicine physicians. Sixty primary CC and forty LM lesions were segmented accordingly. In the cases of multiple LM lesions, the lesion with the largest diameter was chosen for segmentation. In a univariate analysis approach, we used Spearman correlation with multiple testing correction (Benjamini-Hutchberg false discovery rate (FDR), α = 0.05) to ascertain the relationship between SUVmax and CT radiomic features. RESULT: Twenty-two (52.3%) and twenty-six (61.9%) CT radiomic features were found to be significantly correlated with SUVmax values of primary CC (n = 60) and LM (n = 40) lesions, respectively (FDR-corrected p value < 0.05 and 0.6 < |ρ| < 1). GLCM_homogeneity (ρ = 0.839), GLCM_dissimilarity (ρ = - 0.832), GLZLM_ZLNU (ρ = 0.827), and GLCM_contrast (ρ = - 0.815) were the 4 features most correlated with SUVmax in CC. On the other hand, in LM, the 4 features most correlated with SUVmax were GLRLM_LRHGE (ρ = 0.859), GLRLM_LRE (ρ = 0.859), GLRLM_LRLGE (ρ = 0.857), and GLRLM_RP (ρ = - 0.820). CONCLUSION: We investigated the relationship between SUVmax of preoperative primary CC lesions and their LM with CT radiomic features. We found some CT radiomic features having relationships with the metabolic characteristics of lesions. This work suggests that non-invasive predictive imaging biomarkers for precision medicine can be derived from CT radiomic.

Prediction of breast dose in chest CT examinations using adaptive neuro-fuzzy inference system (ANFIS).

In chest computed tomography (CT), the breasts located within the scan range receive a substantial radiation dose. Due to the risk of breast-related carcinogenesis, analyzing the breast dose for justification of CT examinations seems necessary. The main goal of this study is to overcome the limitations of conventional dosimetry methods, such as thermoluminescent dosimeters (TLDs) by introducing the adaptive neuro-fuzzy inference system (ANFIS) approach. In this study, the breast dose of 50 adult female patients who underwent chest CT examinations was measured directly by TLDs. Then, the ANFIS model was developed with four inputs including dose length product (DLP), volumetric CT dose index (CTDIvol), total mAs, and size-specific dose estimate (SSDE), and one output (TLD dose). Additionally, multiple linear regression (MLR) as a traditional prediction model was used for linear modeling and its results were compared with the ANFIS. The TLD reader results showed that the breast dose value was 12.37 ± 2.46 mGy. Performance indices of the ANFIS model, including root mean square error (RMSE) and correlation coefficient (R), were calculated at 0.172 and 0.93 for the testing dataset, respectively. Also, the ANFIS model had superior performance in predicting the breast dose than the MLR model (R = 0.805). This study demonstrates that the proposed ANFIS model is efficient for patient dose prediction in CT scans. Therefore, intelligence models such as ANFIS are suggested to estimate and optimize patient dose in CT examinations.

Evaluation of the Mitigation Effect of Spirulina Against Lung Injury Induced by Radiation in Rats.

BACKGROUND: Some compounds have been investigated to mitigate the effect of radiation on the lung, such as pneumonitis and fibrosis. OBJECTIVE: This study aimed to examine the mitigation efficiency of Spirulina compared to the effect of Metformin. METHODS: 25 male Wistar rats were allotted in five groups: control, Spirulina, Radiation, Radiation plus Spirulina, and Radiation plus Metformin. Rat chest regions were irradiated by 15 Gray (Gy) xradiation using aLINAC. Forty-eight hours after irradiation, treatment with Spirulina and Metformin began. Eighty days after irradiation, all rats were sacrificed, and their lung tissues were removed for histopathological, and biochemical assays. RESULTS: The results demonstrated that irradiation increased MDA (Malondialdehyde) levels while suppressing the SOD (superoxide dismutase) and GPx(glutathione peroxidase) activity in the irradiated group. MDA levels in lung tissues were reduced with Metformin but not with Spirulina. Both Metformin and Spirulina increased the SOD and GPx activity in lung tissue. Moreover, histopathological evaluations showed extensive changes in the lung tissue including infiltration of lymph cells around the bronchioles and blood vessels, thickening of the alveolar wall, and the disruption of the alveolar structure, as well as accumulation of collagen fibers. Administration of Spirulina and Metformin significantly reduced pathological changes in lung tissue, although the effect of Metformin was greater than that of Spirulina. CONCLUSION: Spirulina could mitigate radiation-induced lung injury moderately, although Metformin is more effective than Spirulina as a mitigator agent.

Evaluation of Annual Staff Doses and Radiation Shielding Efficiencies of Thyroid Shield and Lead Apron during Preparation and Administration of 131I, 81Kr, and 99mTc-Labeled Radiopharmaceuticals.

Nuclear medicine technicians would receive unavoidable exposures during the preparation and administration of radiopharmaceuticals. Based on the staff dose monitoring, the dose reduction efficiencies of the radiation protection shields and the need to implement additional strategies to reduce the staff doses could be evaluated. In this study, medical staff doses during the preparation and administration of Tc-99 m, I-131, and Kr-81 radiopharmaceuticals were evaluated. The dose reduction efficiencies of the lead apron and thyroid shield were also investigated. GR-207 thermoluminescent dosimeter (TLD) chips were used for quantifying the medical staff doses. The occupational dose magnitudes were determined in five organs at risk including eye lens, thyroid, fingers, chest, and gonads. TLDs were located under and over the protective shields for evaluating the dose reduction efficiencies of the lead apron and thyroid shield. The occupational doses were normalized to the activities used in the working shifts. During preparation and injection of Tc-99 m radiopharmaceutical, the average annual doses were higher in the chest (4.49 mGy) and eye lenses (4 mGy). For I-131 radiopharmaceutical, the average annual doses of the point-finger (15.8 mGy) and eye lenses (1.23 mGy) were significantly higher than other organs. During the preparation and administration of Kr-81, the average annual doses of the point-finger (0.65 mGy) and chest (0.44 mGy) were higher. The significant dose reductions were achieved using the lead apron and thyroid shield. The radiation protection shields and minimum contact with the radioactive sources, including patients, are recommended to reduce the staff doses.

Measurement of Post-Treatment Changes in Brain Metabolites in Patients with Generalized Anxiety Disorder using Magnetic Resonance Spectroscopy.

BACKGROUND: From previous studies, we know the correlations of some brain metabolites with a generalized anxiety disorder (GAD) and its symptoms. The response of GAD patients to various treatments is not the same and finding the best treatment option for each patient takes a long period of time. OBJECTIVE: In this study, we try to examine if there is any relationship between a special treatment option and GAD patients' response and brain metabolite correlation with anxiety level change. MATERIAL AND METHODS: This study is a clinical trial type of studies. We have used proton MRS (1H-MRS) with field strength of 3 Tesla to assess whether a different treatment option makes different responses based on metabolite changes. We chose 16 patients based on Hamilton's anxiety rate and a psychiatrist diagnosis. Patients were divided into two groups randomly. Each group took different treatments. Before treatment started, patients underwent MRS imaging and 8 weeks after treatment as well. Our study lacked a control group, and the results were analyzed by comparing the measured values of metabolites and clinical scores before and after treatment. RESULTS: The NAA and Cho concentration increased after treatments and Cr concentration remained constant in both groups. Both groups showed improvements in their symptoms of anxiety and also in their clinical score rates. Sertraline group showed a more increase in NAA concentration than CBT and also a more decrease in HAMA and HAMD-17 scores. CONCLUSION: A simultaneously increase in NAA and Cho in both groups and a decrease in clinical anxiety levels demonstrate that NAA and Cho concentration are associated negatively with anxiety levels. In addition, both CBT and sertraline are effective in the improvement of anxiety symptoms.

Effect of Lactobacillus species on apoptosis-related genes BCL2, BAX, and caspase 3 in the testes of gamma-irradiated rats.

OBJECTIVE: Ionizing radiation has various applications, including uses in medicine, industry, agriculture, and research. However, ionizing radiation is accompanied by side effects in normal radiosensitive tissues. Probiotics as natural radioprotective agents can protect normal tissues from ionizing radiation. In this regard, this study aimed to investigate the effect of Lactobacillus species on apoptosis-related genes BCL2, BAX, and caspase 3 (CASP3) in the testes of gamma-irradiated rats. METHODS: A total of 30 male Wistar rats were involved in this study. The animals received the whole- body radiation with the dose rate of 2 Gy gamma-ray and were orally gavaged with 0.2 mL of 1×1010 Lactobacillus species in phosphate-buffered saline (PBS) for 4 weeks. Then, the relative gene expression levels of BCL2, BAX, and CASP3 in the testis were assessed by using the quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: Compared with the control group, radiation significantly downregulated the BCL2 and upregulated the BAX and CASP3 genes (p<0.0001). However, Lactobacillus species significantly reversed these effects. CONCLUSION: All in all, according to our results, employing Lactobacilli probiotics as a natural radioprotector may protect radiosensitive tissue from damage.

Co-treatment with Ginsenoside 20(S)-Rg3 and Curcumin increases Radiosensitivity of MDA-MB-231 Cancer Cell Line.

Background: Breast cancer is the second most common cancer in women worldwide. Developing drugs increase the radiosensitivity effect of tumoral tissue, while protecting normal tissues has gained much attention. Ginsenoside Rg3, one of the active components of ginseng, has been shown to possess various pharmacological effects and antiproliferation activity on cancer cell lines. In this study, we assessed the anti-cancer effect of co-treatment with ginsenoside 20(S)-Rg3 and curcumin on MDA-MB-231 breast cancer cells with and without radiotherapy. Methods: MTT assay was applied using different concentrations of ginsenoside 20(S)-Rg3 (0, 10, 80, 150 µmol/l) and curcumin (0, 10, 30, 50, 90 µg/mL). The inhibitory effect of co-treatment with these herbal drugs with and without 4 Gy radiotherapy on the MDA-MB-231 cell line was examined. Flow cytometry was applied to measure the effect of co-treatment of the drugs on radiation-induced apoptosis. The data were analyzed using ANOVA and Kruskal-Wallis tests. P values<0.05 were considered statistically significant. Results: The results of the MTT assay showed that ginsenoside 20(S)-Rg3 and curcumin had an inhibitory effect on the MDA-MB-231 cell line in a concentration-dependent manner. Ginsenoside 20(S)-Rg3 and curcumin inhibited tumor cell development and proliferation at concentrations of 80 µmol/L and 30 µg/mL, respectively, with 50% cell viability (P=0.018, P=0.01, respectively) at 48 hour incubation time. Conclusion: Ginsenoside 20(S)-Rg3 and curcumin inhibited MDA-MB-231 cell growth in a dose- and time-dependent manner and increased the radiosensitivity of cancer cells. These herbal drugs can be considered as a radiosensitizer in radiotherapy.

Assessment Synergistic Effects of Integrated Therapy with Epigallocatechin-3-Gallate (EGCG) & Arsenic Trioxide and Irradiation on Breast Cancer Cell Line.

BACKGROUND: Breast cancer is the most common invasive malignancy among women in the world. The current breast cancer therapies pose significant clinical challenges. Low-dose chemotherapy represents a new strategy to treat solid tumors in combination with natural products such as green tea catechins. Epigallocatechin-3-gallate (EGCG) is the major polyphenolic extract from green tea with potent anticancer and antioxidant effects. The purpose of this study was to investigate the effects of EGCG, Arsenic trioxide (ATO) and gamma radiation on MCF-7 cell line. METHODS: The anti-proliferative effects of EGCG and ATO individually, moreover in combination with radiation on MCF-7 cells were evaluated with MTT assay. The expression of apoptotic gens (Bax, Bcl-2, Caspase-3 and Fas) was assessed by real-time PCR. RESULTS: Based on the results of MTT assay, EGCG and ATO exhibited dose and time-dependent anti-proliferative effects on MCF-7 cells. The combined therapy of EGCG and ATO in presence and absence radiation could rise cell death up to 80%. Moreover, integrated therapy made Bax up-regulated and Bcl-2 down- regulated. CONCLUSION: In assessment synergistic effects of integrated therapy with EGCG and ATO and irradiation had been significant impact on low dose chemotherapy for breast cancer treatment.

Investigating the expression level of NF-KB and HIF1A genes among the inhabitants of two different background radiation areas in Ramsar, Iran.

This study investigated the fluctuation of NF-KB and HIF-1a gene expression between inhabitants of a high-level background radiation area (HBRA) and a normal-level background radiation area (NBRA) of Ramsar, Iran. Sixty participants with the mean age of 48 ± 15 years were selected and divided into two groups. The group receiving a dose of ≤1.5 mGy/year (NBRA) was considered the control group and the target group (HBRA) received a dose of >1.5 mGy/year. These two groups were from neighbor regions to minimize socioeconomic differences between the participants. Blood samples were collected from each group and NF-KB and HIF-1a expression levels were compared using quantitative real-time PCR (qPCR) based on the stem loop method. The effects of residency duration in the respective areas and gender on the expression of NF-KB and HIF-1a was also examined. The HIF-1a expression level was statistically lower in the HLBRA region (P < 0.0002), while NF-KB expression was upregulated (P < 0.0001). Although the under-expression of HIF-1a in response to dose rate was significant in females (P < 0.0004), it was not different in males (P = 0.74), indicating a significant difference between sexes (P = 0.0047). The upregulation of NF-KB expression related to dose level was also significant for the female group (P < 0.0001), whereas it was not for the male group (P = 0.72). Notably and as expected, there was a significant relation between longer residency in the HBRA and HIF-1A under-expression (P < 0.026), while there was no effect of increasing residency time for NF-KB over-expression level (P = 0.29). The dwellers of the HBRA those noted that despite receiving an elevated radiation level were seemingly good in general health, showed some alterations in their molecular mechanisms, specifically HIF-1a and NF-KB expression levels. It is not clear if this is indicative of a beneficial adaptive response and more research is recommended.

Multifunctional MIL-Cur@FC as a theranostic agent for magnetic resonance imaging and targeting drug delivery: in vitro and in vivo study.

Owing to the importance of multifunctional theranostics as promising systems to overcome key problems of conventional cancer therapy, in this study a multifunctional metal-organic framework-based (MOF) theranostic system was prepared and applied as intelligent theranostic systems in cancer. Iron-based MOF, MIL-88B, in a multi-faceted shape was initially prepared. Curcumin (Cur) was then loaded into the pores of MIL and folic acid-chitosan conjugate (FC) was finally coated on the surface of the carrier to accomplish cancer-specific targeting properties. MTT assay revealed perfect cytocompatibility of the system and selective toxicity against cancerous cells. In vivo MRI images showed high tumour uptake for MIL-Cur@FC and high T1-T2 contrast effect. The growth inhibiting efficiencies of MIL-Cur@FC on M109 tumour bearing Balb/C mice without reducing their body weight showed maximum tumour eradication with no significant toxicities. Due to the outstanding features of the system achieved from in vitro and in vivo studies, we believe that this study will provide a novel approach for developing targeted theranostic agents in cancer diagnosis and treatment.

Evaluation of skeletal age based on Greulich-Pyle method in Tehran.

Although bone age plays a special role in determining the child's age, there are some variations in skeletal growth of different people. The aim of this study was to compare the bone age with chronological age of children aged 2-18 years old in order to recognize whether Greulich-Pyle (GP) method could be reliable for Iranian children? The standard radiograph of Left hand was taken in 40 healthy subjects, then the bone age was determined according to GP. Mean ±â€¯SD bone ages were delayed 1.12 ±â€¯0.65, 0.82 ±â€¯1.34 and 0.10 ±â€¯0.51 years than the mean chronological ages in 2.99-5.99, 10-13.99 and 14-17.99 age group, respectively; and advanced -0.33 ±â€¯3.12 years in the 6-9.99 age group. In BMI levels <18.5, 18.5-24.9, 25-29.9 and ≥30, Mean ±â€¯SD bone ages in males were delayed 2.25 ±â€¯0.21, 0.14 ±â€¯0.55, 0.87 ±â€¯0.41 and 4.05 ±â€¯0.70 years than the mean chronological ages, respectively. In BMI range of 18.5-24.9 and BMI ≥ 30, Mean ±â€¯SD bone age in females was delayed 0.50 ±â€¯0.49 and 0.45 ±â€¯0.63 years than the mean chronological ages, respectively. For BMI < 18.5, Mean ±â€¯SD bone age in females were advanced -0.40 ±â€¯2.69 years than mean chronological ages. Considering these differences, Iranian boys may have a different pattern of bone growth from GP standards.

Cytogenetic effects of radiation and genetic polymorphisms of the XRCC1 and XRCC3 repair genes in industrial radiographers.

Different types of DNA damages caused by ionizing radiation may enhance the cancer risk in exposed individuals. Inherited variations in DNA repair genes cause the inter-individual variability in response to ionizing radiation. The purpose of this study was to determine the association between single nucleotide polymorphism (SNP) of two important DNA repair genes (XRCC1 R399Q and XRCC3 T241M) and the level of DNA damage investigated by micronucleus (MN) frequency in peripheral blood lymphocytes of 120 industrial radiographers (IR) and 120 non-exposed control individuals. The frequencies of MN and nucleoplasmic bridges were significantly higher in the IR group than in the control group (33.83 ± 11.96 vs. 7.47 ± 2.96, p < 0.0001 and 1.69 ± 1.86 vs. 0.12 ± 0.33, p < 0.0001). MN frequencies in the IR group were associated with the cumulative radiation doses (p < 0.0001, r = 0.58 for last 1 year of exposure and p < 0.0001, r = 0.67 for last 5 years of exposure). Polymorphism of XRCC3 T241M was associated with higher MN frequencies in the IR group. However, the same result was not observed between XRCC3 SNP and MN frequency in the control group. Consequently, XRCC3 241Met alleles may cause the increased DNA damage in the industrial radiographers.

Radioprotective effects of vitamin A against gamma radiation in mouse bone marrow cells.

Radioprotectors by neutralizing the effects of free radicals, reduce the destructive effects of radiation. In this protocol article, the radioprotectory effect of vitamin A on micronuclei induced by gamma radiation was evaluated using micronucleus test. Vitamin A was injected intraperitoneally at 100 and 400 mg/kg two hours before 2 Gray (Gy) of gamma radiation. Animals were sacrificed after 24 h, and then specimens of the bone marrow were smeared and stained. The number of micronuclei were counted in polychromatic cells. Both dosage of vitamin A reduced the micronucleus in bone marrow polychromatic erythrocytes (MnPCE) level, which is statistically significant. The appropriate amount of vitamin A for protection in mice is 100 mg/kg, which protect the bone marrow of mice against clastogenic effects of radiation. The results of the study showed that vitamin A, possibly with an antioxidant mechanism, eliminates the effects of free radicals from ionizing radiation on bone marrow cells and reduces genetic damage. •The data of radioprotective effects of vitamin A showed that administration of 100 mg/kg vitamin A to mice prior to 2 Gy of gamma radiation has reduced the micronucleus levels in PCE cells by a factor of 2.62.•Administration of 100 mg/kg vitamin A, which is much smaller than LD50 of vitamin A (LD50 for intraperitoneal injection = 1510 ± 240 mg/kg) can protect mice.•Vitamin A reduces the harmful effects of ionizing radiation on DNA, due to the antioxidant activity and the trapping of free radicals produced by radiation, and diminish the genetic damage caused by radiation.•Vitamin A has no effect on the proliferation and differentiation rate of bone marrow cells.

The challenges of E-learning system: Higher educational institutions perspective.

INTRODUCTION: The development of information technology (IT) in education has led to the expansion of new teaching and learning methods at universities. Implementation of E-learning programs at Iran's universities as well as assessing the prerequisites and level of preparation of learners to attend E-learning environments require extensive study. Therefore, this study examined to investigate the challenges of E-learning system at Tehran University of Medical Sciences. METHODOLOGY: This study was a descriptive and cross-sectional one that conducted in 2016_2017. The statistical populations were all of the students that have an E-learning course in Tehran University of Medical Sciences, from whom, 300 were selected to participate in the study using a stratified random sampling method. The tool of the study was a researcher-made questionnaire. The data were analyzed through SPSS software. RESULTS: According to the findings of this study, about half of the participants (40%) had problems accessing the technology, and only 26.4% of the participants had good preparation for the use of E-learning system. Furthermore, a significant difference was found between the challenges of skill and culture of the participants (P value = 0.01). CONCLUSION: Success in the implementation of E-learning educational system as one of the main approaches in managing knowledge and educational needs of higher education organization will not be achieved without identifying the different skill, technical and cultural challenges. To overcome this challenge, establishing IT infrastructure and standards, using experiences of the leading countries in the field of E-learning, creating proper culture, and familiarizing learners and teachers to the development and use of E-learning materials are necessary.

The Effect of Melatonin on Superoxide Dismutase and Glutathione Peroxidase Activity, and Malondialdehyde Levels in the Targeted and the Non-targeted Lung and Heart Tissues after Irradiation in Xenograft Mice Colon Cancer.

PURPOSE: Radiation causes damage to irradiated tissues and also tissues that do not receive direct irradiation through a phenomenon called bystander effects. Melatonin as a potent antioxidant and anti-inflammatory agent is known for protection of normal tissues against ionizing irradiation. In addition, some studies have suggested that Melatonin may have some anti-cancer properties. Although the complete mechanisms remain unknown, it can act via immunomodulatory effects. The aim of this study was to evaluate the effect of pretreatment with melatonin on oxidative damage caused by direct irradiation and bystander effects on the lung and heart tissue after xenograft mice colon cancer irradiation in Balb/c mice. MATERIALS AND METHODS: Forty nine (49) Balb/c mice were evenly divided into 7 groups including control, irradiation of 5 Gy directly to tumor, melatonin treatment (20 mg/kg) and irradiation (5 Gy single fraction) directly to tumor, irradiation of 5 Gy directly to chest area, melatonin treatment (20 mg/kg) and radiation directly to chest, only melatonin treatment and whole-body scatter group (which gave radiation dose equal to the amount of radiation that the lung had received from the localized pelvic irradiation) to evaluate the effect of melatonin on the MDA level as well as SOD and GPx activity after 24 and 72 h of irradiation of 5 Gy single fraction directly to the tumor tissue and chest area, in the tumor tissue, the lung tissue, and the heart tissue. RESULTS: The results revealed that exposure to irradiation resulted in an increase in MDA level and suppressed SOD and GPx activity in the targeted and non-targeted lung and heart tissues, and the tumor tissue. Melatonin decreased MDA level in the lung and heart tissues. Also, melatonin improved SOD and GPx activity in non-targeted tissues, while it was able to reduce these two enzymes and decreased MDA level in the tumor tissue. CONCLUSION: Melatonin exhibited its ability to ameliorate oxidative stress in both targeted and nontargeted tissues. Administration of melatonin boosted SOD and GPx activity in the normal tissues, but not in the tumor cells. Through stimulation and suppression of the antioxidant system, Melatonin may cause sensitization of the tumor cells while protecting the normal tissues.

Prediction of dose to the relatives of patients treated with radioiodine-131 using neural networks.

In this study, the effective dose received by the family members and caregivers of 52 thyroid cancer patients, who had been treated with radioiodine I-131, was measured to investigate the ability of the neural network to predict the doses to the relatives. The effectiveness of this method to predict the relatives who will receive doses of more than 1 mSv was evaluated. The effective doses were measured by TLD. The inputs of the neural network include 13 different parameters that can potentially affect the dose, and the output was the dose to the family members. The neural networks in this study were feed-forward with a sigmoid activation function and one hidden layer. The mean and median of the measured doses were 0.45 and 0.28 mSv and its range was 0.1-3.64 mSv. The mean square error of the predicted doses by the neural network and the measured doses by TLD (mean squared error) for 99 individuals was 0.142. The optimum neural network was able to predict all the relatives who received doses of more than 1 mSv. The area under the receiver operating characteristic curve for the trained neural network was 0.957, showing its ability to distinguish these groups. Predicting the dose to a patient's relatives before release is a helpful strategy for future optimisation. Using neural networks is a promising method for predicting the dose to the family members and defining high-risk patients and relatives. Patient-specific criteria for release and patient-specific advice and consultation can be used to reduce the dose to each family member.

Prevention of γ-Radiation-Induced DNA Damage in Human Lymphocytes Using a Serine-Magnesium Sulfate Mixture.

OBJECTIVES: Ionising radiation has deleterious effects on human cells. N-acetylcysteine (NAC) and cysteine, the active metabolite of NAC, are well-known radioprotective agents. Recently, a serine-magnesium sulfate combination was proposed as an antidote for organophosphate toxicity. This study aimed to investigate the use of a serine-magnesium sulfate mixture in the prevention of γ-radiation-induced DNA damage in human lymphocytes as compared to NAC and cysteine. METHODS: This study was carried out at the Iran University of Medical Sciences, Tehran, Iran, between April and September 2016. Citrated blood samples of 7 mL each were taken from 22 healthy subjects. Each sample was divided into 1 mL aliquots, with the first aliquot acting as the control while the second was exposed to 2 Gy of γ-radiation at a dose rate of 102.7 cGy/minute. The remaining aliquots were separately incubated with 600 µM concentrations each of serine, magnesium sulfate, serine-magnesium sulfate, NAC and cysteine before being exposed to 2 Gy of γ-radiation. Lymphocytes were isolated using a separation medium and methyl-thiazole-tetrazolium and comet assays were used to evaluate cell viability and DNA damage, respectively. RESULTS: The serine-magnesium sulfate mixture significantly increased lymphocyte viability and reduced DNA damage in comparison to serine, magnesium sulfate, NAC or cysteine alone (P <0.01 each). CONCLUSION: The findings of the present study support the use of a serine-magnesium sulfate mixture as a new, non-toxic, potent and efficient radioprotective agent.

A cytogenetic biomonitoring of industrial radiographers occupationally exposed to low levels of ionizing radiation by using cbmn assay.

Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. The average annual effective dose in industrial radiography is one of the highest among radiation workers. The aim of this study was to investigate the cytogenetic effects of ionizing radiation in the peripheral blood lymphocytes of 60 industrial radiographers and 40 non-exposed individuals as the control group by using cytokinesis-block micronucleus (CBMN) assay. Totally, the frequencies of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) were significantly higher in the industrial radiographers than in the controls (p = 0.000). The mean MN frequency per 1000 binucleated cells in the industrial radiographers with last 5-y radiation dose of >100 mSv was significantly higher than those with ≤100 mSv (34.81 ± 12.7‰ vs. 26.33 ± 7.94‰, p = 0.024). The effect of age was observed in the control group and subjects with the age of >30 y showed significantly higher MN frequency compared with the subjects with the age of ≤30 y (9.45 ± 3.71‰ vs. 6.81 ± 3.05‰, p = 0.02). No obvious trend of increased MN as a function of either duration of employment or age or smoking status was observed in the industrial radiographers. The results show the increased levels of cytogenetic damages in the industrial radiographers. Even the workers exposed to the permissible doses are subjected to elevated frequencies of DNA damages. These findings confirm the importance of cytogenetic biomonitoring program beside physical dosimetry, surveying radiation safety of equipment and periodic training of workers for improvement of safety and radiation protection.

Radioprotective effects of selenium and vitamin-E against 6MV X-rays in human blood lymphocytes by micronucleus assay.

BACKGROUND: Critical macromolecules of cells such as DNA are in exposure to damage of free radicals that induced from the interaction of ionizing radiation with biological systems. Selenium and vitamin-E are natural compounds that have been shown to be a direct free radical scavenger. The aim of this study was to investigate the radioprotective effect of selenium and vitamin-E separately and synergistically against genotoxicity induced by 6MV x-rays irradiation in blood lymphocytes. METHODS: Fifteen volunteers were divided into three groups include A, B and C. These groups were given selenium (800IU), vitamin-E (100mg) and selenium (400IU) + vitamin-E (50mg), respectively. Peripheral blood samples were collected from each group before (0hr) and 1, 2 and 3hr after selenium and vitamin-E administration (separately and synergistically). Then the blood samples were irradiated to 200cGy of 6MV x-rays. After that lymphocyte samples were cultured with mitogenic stimulation to determine the chromosomal aberrations with micronucleus assay in cytokinesis-blocked binucleated cells. RESULTS: The lymphocytes in the blood samples collected at one hr after ingestion selenium and vitamin-E, exposed in vitro to x-rays exhibited a significant decrease in the incidence of micronuclei, compared with control group at 0hr. The maximum protection and decrease in frequency of micronuclei (50%) were observed at one hr after administration of selenium and vitamin-E synergistically. CONCLUSION: The data suggest that ingestion of selenium and vitamin-E as a radioprotector substance before exposures may reduce genetic damage caused by x-rays irradiation.

Origanum vulgare leaf extract protects mice bone marrow cells against ionizing radiation.

OBJECTIVE: Ionizing radiation produces free radicals which induce DNA damage and cell death. Origanum vulgare leaf extract (OVLE) is a natural compound and its capability of scavenging free radicals and its antioxidant activity have been demonstrated by many researchers. In this study, using micronucleus assay, radioprotective effect of OVLE against clastogenic and cytotoxic effect of gamma irradiation has been investigated in mice bone marrow cells. MATERIALS AND METHODS: OVLE was injected intraperitoneally to the BALB/c mice 1hr prior to gamma irradiation (3Gy) at the doses of 100 and 200 mg/kg. Twenty four hours after irradiation or treatment, animals were killed and smears were prepared from the bone marrow cells. The slides were stained with May Grunwald-Giemsa method and analyzed microscopically. The frequency of micronucleated polychromatic erythrocytes (MnPCEs), micronucleated normochromatic erythrocyte (MnNCEs) and cell proliferation ratio PCE/PCE+NCE (polychromatic erythrocyte/polychromatic erythrocyte + normochromatic erythrocyte) were calculated. RESULTS: The results showed that gamma irradiation (3Gy) increased the frequency of MnPCEs, MnNCEs and reduced the PCE/PCE+NCE ratio in mice bone marrow compared to the non-irradiated control group (p<0.0001). Injection of OVLE significantly reduced the frequency of MnPCEs (p<0.0001) and MnNCEs (p<0.05) and increased the PCE/PCE+NCE ratio as compared to the irradiated control group (p<0.05). CONCLUSION: It seems that OVLE with its antioxidant properties and its capability of scavenging free radicals and reactive oxygen species can reduce the cytotoxic effects of gamma irradiation in mice bone marrow cells.