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Objective: To evaluate the effect of melatonin as a protective treatment for the tongue in irradiated rats. Materials and Methods: Male Sprague Dawley rats were subjected to a single session of 50 Gy radiation and treated with melatonin 30 minutes before and after the radiotherapy session. A clinical evaluation was carried out a week and a half, third- and sixth-week post-treatment; finally, a tongue biopsy was taken for a histopathological study in the third and sixth weeks after radiation. Results: Clinical evaluation shows a clear trend, that preventive administration of melatonin could facilitate the recovery of mucosal tissue after radiation. Additionally, cellular infiltrate was 40% fewer in the melatonin-treated group compared to the control, as well as the number of the congested vessel were fewer. Conclusion: These findings showed for the first time the preventive role of melatonin in the tongue mucosa reducing the changes associated with mucositis, inflammatory infiltrate, and congestive blood vessels.

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Uranium mining can cause environmental impacts on non-human biota around mine sites. Because of this, the reduction in non-human biota exposure becomes an important issue. Environmental radioprotection results from the evolution of human radioprotection; it is based on dose rate to non-human biota and uses, as a biological target, and has harmful effects on populations. In the present study, a flooded impoundment created following dam construction in a uranium mine plant undergoing decommissioning was investigated. Internal dose rates due to activity concentration of natural uranium (Unat) and 232Th in omnivorous, phytophagous, and carnivorous fish species were estimated. Radionuclide activity concentrations were obtained by spectrophotometry with arsenazo III in the visible range. The dose rate contribution of 232Th was lower than that of Unat. There were no differences between the internal dose rates to studied fish species due to 232Th, but there were differences for Unat. A dose rate of 2.30·10-2 µGy∙d-1 was found due to the two studied radionuclides. Although this value falls below the benchmark for harmful effects, it is important to acknowledge that the assessment did not account for other critical radionuclides from uranium mining, which also contribute to the internal dose. Moreover, the study did not assess external doses. As a result, the possibility cannot be excluded that dose rates at the study area overcome the established benchmarks for harmful effects.

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Introduction Anesthetists play an important role during interventional radiology procedures. Like the main operator, anesthetists may also be subject to significant radiation levels in the fluoroscopy suite. Due to its complexity, hepatic chemoembolization procedures demand high fluoroscopic times and digital subtraction angiography images, exposing patients and medical staff to high radiation doses. Objective To assess and quantify the radiation to which one anesthetist was exposed over the course of seven consecutive hepatic chemoembolization procedures, and compare it to the exposure received by the main operator. Methods Medical staff dosimetry was evaluated during seven consecutive hepatic chemoembolization procedures conducted in a private hospital in Recife (Brazil), using thermoluminiscent dosimeters placed in regions of the head and torso. Results For the seven procedures evaluated in this study, the anesthetist received, on average, absorbed doses to the glabella, left eyebrow, right eyebrow and effective dose of 142.4 ± 72 µSv, 117.3 ± 66 µSv, 137.8 ± 71 µSv and 12.4 ± 8.4 µSv, respectively. Conclusions In some cases, ocular dose and effective dose received by the anesthetist may be 4 and 4.7 times greater, respectively, when compared to the main operator. According to the results of this study, the current occupational annual dose limit to the lens of the eye of 20 mSv can be exceeded with only two hepatic chemoembolization procedures per week if adequate radiation protection conditions are not guaranteed.

Introducción El anestesiólogo desempeña un papel importante durante los procedimientos de radiología intervencionista. Al igual que el operador principal, el anestesiólogo también puede estar expuesto a niveles significativos de radiación en la sala de fluoroscopía. Debido a su complejidad, durante los procedimientos de quimioembolización hepática se deben utilizar imágenes de fluoroscopía y angiografía de sustracción digital por períodos prolongados, exponiendo a los pacientes y al personal médico a dosis elevadas de radiación. Objetivo Evaluar y cuantificar la radiación a la cual se expuso un anestesiólogo durante el transcurso de siete procedimientos consecutivos de quimioembolización hepática, y comparar con la exposición recibida por el operador principal. Métodos Evaluación de la dosimetría ocupacional durante siete procedimientos consecutivos de quimioembolización hepática realizados en un hospital privado de Recife (Brasil) por medio de dosímetros termoluminiscentes ubicados en regiones de la cabeza y el torso. Resultados Para los siete procedimientos evaluados en este estudio, el anestesiólogo recibió, en promedio, dosis absorbidas en el entrecejo, la ceja izquierda, la ceja derecha y dosis efectivas de 142,4 ± 72 µSv, 117,3 ± 66 µSv, 137,8 ± 71 µSv y 12,4 ± 8,4 µSv, respectivamente. Conclusiones En algunos casos, la dosis ocular y la dosis efectiva que recibe el anestesiólogo puede ser, respectivamente, entre 4 y 4,7 veces más alta que la que recibe el operador principal. De acuerdo con los resultados de este estudio, el límite ocupacional anual de dosis en cristalino (20 mSv) se puede superar con apenas dos procedimientos de quimioembolización hepática a la semana en caso de no garantizarse las condiciones adecuadas de protección contra la radiación.

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Fish from a Funil dam reservoir associated with a Nuclear Fuel Factory were sampled aiming to assess the radiological risk due to ingestion. Funil dam reservoir is a strategic site, once it receives effluent from the industrial complex that performs isotopic enrichment of uranium and conversion of UF6. The mean activity concentrations obtained for 40K, 226Ra, 228Ra and 228Th were 57.81, 0.41, 0.92 and 0.49 Bq·kg-1, respectively. Lifetime cancer risk was estimated in ∼10-5 and no action needs to be taken.

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The aim of this study was to compare the kinetics of the in vivo action of equimolar doses of methyl gallate (MG) and epigallocatechin gallate (EGCG) on their capacity to induce DNA damage and to protect against DNA damage induced by 60 Co gamma rays. DNA-damaged cells were determined by single-cell gel electrophoresis (comets) in murine peripheral blood leukocytes. The maximum radioprotective effects of MG and EGCG (approximately 70%) occurred at 15 min after administration when their effect was determined 2 min following irradiation. MG and EGCG have similar radioprotective indexes, which due to their fast response indicate that they are involved in free radical scavenging. Due to the similar radioprotective activities of MG and EGCG, the in vivo radioprotective effects of these agents do not seem to be dependent on the number of hydroxyl groups present in their structures but instead on the presence of the galloyl radical. EGCG induces an early, significant, and persistent increase in the number of DNA-damaged cells and a later and more important increase in the number of damaged cells, suggesting that it has two mechanisms by which it can induce DNA damage. MG at the same molar dose as EGCG caused a significant and persistent increase in DNA damaged cells but to a much lesser extent to that induce by EGCG, suggesting that the galloyl radical is not involved in the mechanism of DNA breaks induction.

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PURPOSE: Radiotherapy is a critical component of cancer treatment, along with surgery and chemotherapy. Approximately, 90% of cancer patients undergoing pelvic radiotherapy show gastrointestinal (GI) toxicity, including bloody diarrhea, and gastritis, most of which are associated with gut dysbiosis. In addition to the direct effect of radiation on the brain, pelvic irradiation can alter the gut microbiome, leading to inflammation and breakdown of the gut-blood barrier. This allows toxins and bacteria to enter the bloodstream and reach the brain. Probiotics have been proven to prevent GI toxicity by producing short-chain fatty acids and exopolysaccharides beneficial for protecting mucosal integrity and oxidative stress reduction in the intestine and also shown to be beneficial in brain health. Microbiota plays a significant role in maintaining gut and brain health, so it is important to study whether bacterial supplementation will help in maintaining the gut and brain structure after radiation exposure. METHODS: In the present study, male C57BL/6 mice were divided into control, radiation, probiotics, and probiotics + radiation groups. On the 7th day, animals in the radiation and probiotics + radiation groups received a single dose of 4 Gy to  whole-body. Posttreatment, mice were sacrificed, and the intestine and brain tissues were excised for histological analysis to assess GI and neuronal damage. RESULTS: Radiation-induced damage to the villi height and mucosal thickness was mitigated by the probiotic treatment significantly (p < 0.01). Further, radiation-induced pyknotic cell numbers in the DG, CA2, and CA3 areas were substantially reduced with bacterial supplementation (p < 0.001). Similarly, probiotics reduced neuronal inflammation induced by radiation in the cortex, CA2, and DG region (p < 0.01). Altogether, the probiotics treatment helps mitigate radiation-induced intestinal and neuronal damage. CONCLUSION: In conclusion, the probiotic formulation could attenuate the number of pyknotic cells in the hippocampal brain region and decrease neuroinflammation by reducing the number of microglial cells.

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Uranium mining causes several radiological impacts on the surrounding environment, notably in the water bodies, mainly due to the release of long half-life radionuclides from the 238U and 232Th series. The Ore Treatment Unit, an old uranium mine undergoing decommissioning, has three points of liquid effluent release (#014, #025, and #076). For current study, 78 samples of water were collected at #014, 33 samples at #025, and 63 samples at #076. The radionuclides were analyzed by gross alpha count, gross beta count, and by arsenazo spectrophotometry. Analyses were carried out using the radiological water quality criterion established by World Health Organization and other organizations, together with the Brazilian legislation, to assess if the released effluents may be used unrestrictedly by the individuals of the public. At #014, the mean values of activity concentration (AC), in Bq·L-1, were as follows: Unat = 0.107, 226Ra = 0.035, 210Pb = 0.031, 232Th = 0.007, and 228Ra = 0.049. At #025 the mean values of AC, in Bq·L-1, were as follows: Unat = 0.086, 226Ra = 0.015, 210Pb = 0.028, 232Th = 0.006, and 228Ra = 0.032. Finally, at point #076, the mean AC values, in Bq·L-1, were as follows: Unat = 3.624, 226Ra = 0.074, 210Pb = 0.054, 232Th = 0.013, and 228Ra = 0.069. The current study showed that natural radionuclides were not in secular equilibrium. Despite uranium presented its values outside the limits of guidance levels, it can be state that the unrestricted use of effluents released in the three water bodies is authorized from the radiological point of view. In terms of dose rate, the releases at three points were within the radiological limits of potability. On the other hand, in an additional analysis, #76 presented chemical toxicity above the authorized value, pointing the need of restricted use of water from the point of view of chemical toxicity.

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Male germ cells are particularly susceptible to radiation; infertility being a common consequence after radiotherapy as it impairs spermatogenesis. This study aimed to test whether treatment with losartan (LOS), a selective antagonist of angiotensin II receptor subtype 1 (AT1R), can prevent or attenuate the acute and long-term radiation-induced damage to testes. Wistar rats were randomly distributed into six groups, three of which were studied on day 2 after irradiation: control (CTRL 2), irradiated non-treated (IR 2), and irradiated and treated with LOS (IRLOS 2); and three other groups that were studied on day 60 after irradiation: control (CTRL 60), irradiated non-treated (IR 60), and irradiated and treated with LOS (IRLOS 60). Seven consecutive days before and on the day of irradiation with 2.5 Gy directly administered in the scrotum, the animals were treated with LOS (34 mg/kg/two times/day). This treatment was continued 2 or 60 days after irradiation. The sperm quality was assessed from epididymis cauda. In addition, the testes were submitted to histopathological and morphometric-stereological analysis as well as the proliferating cell nuclear antigen (PCNA) quantification. Serum FSH and LH and plasma testosterone levels were also determined. The data obtained 2 days after the irradiation showed germ cell apoptosis, formation of vacuoles in the seminiferous epithelium, sloughing of germ cells into the lumen, and retention and phagocytosis of step-19 spermatids in Sertoli basal cytoplasm. The treatment with LOS in this period did not prevent or attenuate a radio-induced damage to the testes, illustrating that this drug does not protect against apoptosis derived from direct effects of radiation. On the other hand, 60 days after exposure, the data evidenced the deleterious effects of ionizing radiation on the testes as decreasing of testicular, epididymal, and seminal vesicle masses; tubular atrophy; reduction of cellular proliferation; and loss of germ cells. LOS was able to prevent some of those deleterious effects, promoting improvements in seminal vesicle mass, sperm vitality, plasma testosterone levels, vacuole number, and cell proliferation. In conclusion, inhibition of the AngII/AT1R axis by LOS is effective in protecting the indirect/delayed radiation damage resulting from oxidative stress established in the tissue.

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The Ore Treatment Unit was a uranium mining company that is currently being decommissioned. The local rainfall index makes it necessary to release effluents into the environment. After releasing, the wastewater is available for unrestricted use. Current study aims to use national and international recommendations to assess the radiological potability of released effluents at one of the three points of company's interface with the environment. Twenty-four samples of water were collected and activity concentrations (AC) were obtained by gross alpha count, gross beta count, and for arsenazo spectrophotometry. Statistical analysis techniques were applied to the data with the purpose of understanding the results for the soluble, particulate, and total fractions. The mean AC for effluents were 3.580, 0.082, 0.103, 0.063, and 0.090 Bq L-1 for Unat, 226Ra, 210Pb, 232Th, and 228Ra, respectively, for the total fraction. The analysis of variance pointed to Unat as a critical radionuclide, since it presented more than 90% of the total AC released into the environment. Pearson's R2 pointed to soluble fraction as a major contributor to the total AC released. The guidance level proposed by WHO was used to assess the radiological potability of the effluents. The results obtained indicated the need for trigger other analyses. Committed effective dose was estimated due to the unrestricted use of effluents and the value obtained, 0.23 mSv year-1, was below the maximum allowed limit. Finally, the radiotoxicity of the released effluent was evaluated and the value obtained was ~ 50% of the maximum allowed limit. In conclusion, the present study showed that the level of radioactivity released into the environment by the Ore Treatment Unit does not present a radiological risk to the surrounding population.

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Iodine-131 (I-131) radioisotope it causes the formation of free radicals, which lead to the formation of cell lesions and the reduction of cell viability. Thus, the use of radioprotectors, especially those from natural sources, which reduce the effects of radiation to healthy tissues, while maintaining the sensitivity of tumor cells, stands out. The objective of the present study was to evaluate the cytoprotective/radioprotective effects of whole grape juices manufactured from the conventional or organic production systems, whether or not exposed to ultraviolet (UV-C) light irradiation. The results showed that I-131 presented a cytotoxic effect on human hepatocellular cells (HepG2/C3A) at concentrations above 1.85 MBq/mL, after 24 and 48 hours of treatment, though all concentrations (0.0037 to 7.40 MBq/mL) were cytotoxic to non-tumor human lung fibroblast (MCR-5) cells, after 48 hours. However, grape juices (10 and 20 µL/mL) did not interfere with the cytotoxic effect of the therapeutic dose of I-131 on tumor cells within 48 hours of treatment, while protecting the non-tumor cells, probably due to its high antioxidant activity. In accordance with their nutraceutical potential, antioxidant and radioprotective activity, these data stimulate in vivo studies on the use of natural products as radioprotectants, such as grape juice, in order to confirm the positive beneficial potential in living organisms.

O radioisótopo iodo-131 (I-131) causa a formação de radicais livres, que levam à formação de lesões celulares e redução da viabilidade celular. Assim, destaca-se a utilização de radioprotetores, principalmente de origem natural, que reduzem os efeitos da radiação nos tecidos saudáveis, mantendo a sensibilidade das células tumorais. O objetivo do presente estudo foi avaliar os efeitos citoprotetores/radioprotetores de sucos de uva integral fabricados em sistemas de produção convencional ou orgânico, expostos ou não à radiação ultravioleta (UV-C). Os resultados mostraram que o I-131 apresentou efeito citotóxico nas células hepatocelulares humanas (HepG2/C3A) em concentrações acima de 1,85 MBq/mL, após 24 e 48 horas de tratamento, embora todas as concentrações (0,0037 a 7,40 MBq/mL) fossem citotóxicas para células de fibroblasto de pulmão humano não tumoral (MCR-5), após 48 horas. No entanto, os sucos de uva (10 e 20 µL/mL) não interferiram no efeito citotóxico da dose terapêutica de I-131 nas células tumorais em 48 horas de tratamento, protegendo as células não tumorais, provavelmente devido ao seu alto poder antioxidante. atividade. De acordo com seu potencial nutracêutico, atividade antioxidante e radioprotetora, esses dados estimulam estudos in vivo sobre o uso de produtos naturais como radioprotetores, como o suco de uva, a fim de confirmar o potencial benéfico positivo em organismos vivos.

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This study focusses on the risk of potential exposure to radiation for personnel driving a truck as well as illegal individuals being transported in cargo containers. Inspection facilities usually use a high energy linear accelerator (linac) in order to inspect the cargo. Since this type of equipment has associated health risks due to potential unwanted exposure, the occupational and public dose limits should be calculated in order to develop safer work conditions. This work used a computation model running the code MCNPX to simulate a typical cargo inspection facility which used a linac operating at 4.5 MeV. Two scenarios were considered: (1) exposure of the driver to the primary beam due to a potential failure of the safety sensors; and (2) dose received by an illegal individual being transported inside the cargo container. The results show a dose of 0.8514 mSv per scan for the driver exposed to the primary X-ray beam, and 0.1997 mSv per scan for an individual transported in the cargo box. In conclusion, both the individual and the driver received a dose below the acceptable limit considered safe for an individual (1 mSv/year). However, that was the value of one scan; in a case in which multiple scans would be performed, the dose limit can be quickly exceeded. In that case, the limit would be exceeded by the driver faster than by the individual in the cargo.

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El vino tinto variedad Vitis vinifera L. cv Tannat en los últimos años ha tomado relevancia por su alta concentración de polifenoles, esto le podría significar un rol protector sobre el genoma disminuyendo la formación de lesiones oxidativas. Los efectos a nivel celular de las radiaciones ionizantes en blancos como el ADN, componentes de cascadas de transducción de señales, resultan en lesiones letales, mutagénicas y recombinogénicas y en retardos en el ciclo celular. Se utilizó como modelo eucariota poblaciones de Saccharomyces cerevisiae en fase exponencial expuestas a radiación gamma (200 Gy) en presencia, o ausencia, de vino Tannat (10 % v/v) o de ácido tánico (60 µg/mL). Se estimaron las probabilidades de sobrevida y frecuencia mutagénica en distintas condiciones. Las muestras celulares expuestas a radiación ionizante presentaron una fracción de sobrevida de 0.21 ± 0.02 mientras que en las muestras irradiadas en presencia de vino Tannat o de ácido tánico la fracción de sobrevida fue de 0.33 ± 0.03 y 0.30 ± 0.03 respectivamente. Se observó en las poblaciones irradiadas un aumento significativo de la probabilidad de mutagénesis. En el caso de los tratamientos combinados se observó que la frecuencia mutagénica fue significativamente menor (gamma Tannat: 33%, gamma ácido tánico: 45% ). Estos resultados preliminares podrían indicar radioprotección moderada por parte de los compuestos estudiados, efecto que podría explicarse por las interacciones redox del ácido tánico y polifenoles contenidos en el vino con los radicales libres formados por las radiaciones ionizantes, además de la activación de vías de reparación genómica.

The red wine variety Vitis vinifera L. cv Tannat in recent years has gained relevance due to its high concentration of polyphenols, this could mean a protective role on the genome, reducing the formation of oxidative lesions. The effects at the cellular level of ionizing radiation on targets such as DNA, components of signal transduction cascades, result in lethal, mutagenic and recombinogenic lesions and delays in the cell cycle. Exponential phase populations of Saccharomyces cerevisiae exposed to gamma radiation (200 Gy) in the presence or absence of Tannat wine (10% v / v) or tannic acid (60 µg / ml) were used as a eukaryotic model. The probabilities of survival and mutagenic frequency in different conditions were estimated. Cellular samples exposed to ionizing radiation presented a survival fraction of 0.21 ± 0.02, while in samples irradiated in the presence of Tannat wine or tannic acid, the survival fraction was 0.33 ± 0.03 and 0.30 ± 0.03 respectively. A significant increase in the probability of mutagenesis was observed in irradiated populations. In the case of the combined treatments, it was observed that the mutagenic frequency was significantly lower (Tannat gamma: 33%, Tannic acid gamma: 45%). These preliminary results could indicate moderate radioprotection by the compounds studied, an effect that could be explained by the redox interactions of tannic acid and polyphenols contained in wine with the free radicals formed by ionizing radiation, in addition to the activation of genomic repair pathways.

A variedade de vinho tinto Vitis vinifera L. cv Tannat nos últimos anos tem ganhado relevância devido à sua alta concentração de polifenóis, o que pode significar um papel protetor do genoma, reduzindo a formação de lesões oxidativas. Os efeitos no nível celular da radiação ionizante em alvos como o DNA, componentes de cascatas de transdução de sinal, resultam em lesões letais, mutagênicas e recombinogênicas e atrasos no ciclo celular. Populações de fase exponencial de Saccharomyces cerevisiae expostas à radiação gama (200 Gy) na presença ou ausência de vinho Tannat (10% v / v) ou ácido tânico (60 µg / ml) foram utilizadas como modelo eucariótico. Foram estimadas as probabilidades de sobrevivência e frequência mutagênica em diferentes condições. As amostras celulares expostas à radiação ionizante apresentaram uma fração de sobrevivência de 0,21 ± 0,02, enquanto nas amostras irradiadas na presença de vinho Tannat ou ácido tânico, a fração de sobrevivência foi de 0,33 ± 0,03 e 0,30 ± 0,03, respectivamente. Um aumento significativo na probabilidade de mutagênese foi observado nas populações irradiadas. No caso dos tratamentos combinados, observou-se que a frequência mutagênica foi significativamente menor (Tannat gama: 33%, ácido tânico gama: 45%). Esses resultados preliminares podem indicar radioproteção moderada pelos compostos estudados, efeito que pode ser explicado pelas interações redox do ácido tânico e polifenóis contidos no vinho com os radicais livres formados pela radiação ionizante, além da ativação de vias de reparo genômico.

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BACKGROUND: Neuroimaging is widely used for diagnosis and treatment of stroke. However, little is known about whether the radiation doses received by patients comply with international safety guidelines. OBJECTIVES: The aim of this study was to evaluate the effective radiation dose received while in hospital for stroke and analyze its safety according to current guidelines. METHODS: This cross-sectional study included 109 patients who were hospitalized and diagnosed with ischemic stroke. The National Institutes of Health Stroke Scale was used to evaluate stroke severity, the Bamford clinical classification was used for topography, and the TOAST classification was used for etiology. The computed tomography dose index and size-specific dose estimates were used to calculate the effective radiation dose (ERD) received while in hospital. A Mann-Whitney test was used to compare the ERD received by thrombolysed and non-thrombolysed patients. Non-parametric statistics were used to analyze the data with a 95% confidence interval. RESULTS: During the study period, the median ERD received was 10.9 mSv. Length of stay was not associated with radiation exposure. No differences were demonstrated in ERD according to stroke etiology or Bamford clinical classification. Patients who had CT perfusion (only or in addition to CT or angiotomography) received the highest ERD (46.5 mSv) and the difference compared to those who did not (10.8 mSv) was statistically significant (p<0.001). No differences were found in the ERD between thrombolysed and non-thrombolysed patients. There was no correlation between ERD while in hospital and stroke severity. CONCLUSIONS: According to the current national guidelines, the protocol for examining images at our stroke unit is safe in terms of the ERD received by the patient while in hospital. There was no difference in the ERD received by patients stratified by thrombolytic treatment or stroke severity.

CONTEXTO: A neuroimagem é amplamente utilizada para o diagnóstico e tratamento do acidente vascular cerebral (AVC). No entanto, pouco se sabe se a dose de radiação recebida nesses exames está de acordo com as diretrizes internacionais de segurança. OBJETIVOS: O objetivo deste estudo foi avaliar a dose de radiação efetiva (DRE) durante a hospitalização por AVC. MÉTODOS: Trata-se de estudo transversal com 109 pacientes hospitalizados com diagnóstico de AVC isquêmico. A gravidade do AVC foi avaliada pela National Institutes of Health Stroke Scale, a topografia pela classificação clínica de Bamford e a etiologia pelo Trial of ORG 10172 in Acute Stroke Treatment (TOAST). O índice de dose recebida no exame de tomografia computadorizada (TC) e as estimativas de dose específicas foram usados ​​para calcular a DRE recebida durante a hospitalização. O teste de Mann-Whitney foi utilizado para comparar a DRE recebida por pacientes trombolisados ​​e não trombolisados. Estatísticas não paramétricas foram utilizadas para analisar os dados. RESULTADOS: Durante o período do estudo, a DRE foi de 10,9 mSv. O tempo de internação não foi associado à exposição à radiação. Nenhuma diferença foi demonstrada na DRE de acordo com a etiologia e classificação clínica de Bamford. Os pacientes que fizeram perfusão (isolada, associada à TC ou angiotomografia) receberam a maior DRE (46,5 mSv) em comparação aos que não fizeram (10,8 mSv), sendo estatisticamente significativo (p <0,001). Não foram encontradas diferenças na DRE entre pacientes trombolisados e não trombolisados. Não houve correlação entre a DRE durante a hospitalização com a gravidade do AVC. CONCLUSÕES: De acordo com as atuais diretrizes nacionais, o protocolo de exame de imagens na unidade de AVC é seguro em relação à DRE recebido pelo paciente durante a internação. Não houve diferença na DRE dos pacientes de acordo com o tratamento trombolítico e a gravidade do AVC.

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Abstract Background Neuroimaging is widely used for diagnosis and treatment of stroke. However, little is known about whether the radiation doses received by patients comply with international safety guidelines. Objectives The aim of this study was to evaluate the effective radiation dose received while in hospital for stroke and analyze its safety according to current guidelines. Methods This cross-sectional study included 109 patients who were hospitalized and diagnosed with ischemic stroke. The National Institutes of Health Stroke Scale was used to evaluate stroke severity, the Bamford clinical classification was used for topography, and the TOAST classification was used for etiology. The computed tomography dose index and size-specific dose estimates were used to calculate the effective radiation dose (ERD) received while in hospital. A Mann-Whitney test was used to compare the ERD received by thrombolysed and non-thrombolysed patients. Non-parametric statistics were used to analyze the data with a 95% confidence interval. Results During the study period, the median ERD received was 10.9 mSv. Length of stay was not associated with radiation exposure. No differences were demonstrated in ERD according to stroke etiology or Bamford clinical classification. Patients who had CT perfusion (only or in addition to CT or angiotomography) received the highest ERD (46.5 mSv) and the difference compared to those who did not (10.8 mSv) was statistically significant (p<0.001). No differences were found in the ERD between thrombolysed and non-thrombolysed patients. There was no correlation between ERD while in hospital and stroke severity. Conclusions According to the current national guidelines, the protocol for examining images at our stroke unit is safe in terms of the ERD received by the patient while in hospital. There was no difference in the ERD received by patients stratified by thrombolytic treatment or stroke severity.

Resumo Contexto A neuroimagem é amplamente utilizada para o diagnóstico e tratamento do acidente vascular cerebral (AVC). No entanto, pouco se sabe se a dose de radiação recebida nesses exames está de acordo com as diretrizes internacionais de segurança. Objetivos O objetivo deste estudo foi avaliar a dose de radiação efetiva (DRE) durante a hospitalização por AVC. Métodos Trata-se de estudo transversal com 109 pacientes hospitalizados com diagnóstico de AVC isquêmico. A gravidade do AVC foi avaliada pela National Institutes of Health Stroke Scale, a topografia pela classificação clínica de Bamford e a etiologia pelo Trial of ORG 10172 in Acute Stroke Treatment (TOAST). O índice de dose recebida no exame de tomografia computadorizada (TC) e as estimativas de dose específicas foram usados ​​para calcular a DRE recebida durante a hospitalização. O teste de Mann-Whitney foi utilizado para comparar a DRE recebida por pacientes trombolisados ​​e não trombolisados. Estatísticas não paramétricas foram utilizadas para analisar os dados. Resultados Durante o período do estudo, a DRE foi de 10,9 mSv. O tempo de internação não foi associado à exposição à radiação. Nenhuma diferença foi demonstrada na DRE de acordo com a etiologia e classificação clínica de Bamford. Os pacientes que fizeram perfusão (isolada, associada à TC ou angiotomografia) receberam a maior DRE (46,5 mSv) em comparação aos que não fizeram (10,8 mSv), sendo estatisticamente significativo (p <0,001). Não foram encontradas diferenças na DRE entre pacientes trombolisados e não trombolisados. Não houve correlação entre a DRE durante a hospitalização com a gravidade do AVC. Conclusões De acordo com as atuais diretrizes nacionais, o protocolo de exame de imagens na unidade de AVC é seguro em relação à DRE recebido pelo paciente durante a internação. Não houve diferença na DRE dos pacientes de acordo com o tratamento trombolítico e a gravidade do AVC.

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Humans when exposed to harmful ionising radiations suffer from various pathophysiological disorders including cancer. Radiotherapy is a treatment where these cancerous cells within a tumor aretargeted and killed by means of high energy waves. This therapy is very expensive and involves highly sophisticated instruments. In addition to this, most synthetic radioprotectors including Amifostine have been found to possess toxicity. This led researchers to develop a novel, economically viable, and efficient therapeutic alternative to radiation therapy. The last two decades have observed a major shift towards investigating natural products as radioprotectors, as these are immensely effective in terms of their potential bioequivalence relative to many of the established synthetic compounds available. Taking into account the limitations of radiation therapy, an approach 'Integrative Oncology' that involves a combination of both traditional and conventional medical treatment are used nowadays to treat patients suffering from cancer and associated mental and psychological disorders.

Los seres humanos, cuando se exponen a radiaciones ionizantes nocivas, sufren diversos trastornos fisiopatológicos, incluido el cáncer. La radioterapia es un tratamiento en el que estas células cancerosas dentro de un tumor son atacadas y destruidas por medio de ondas de alta energía. Esta terapia es muy cara e implica instrumentos muy sofisticados. Además de esto, se ha descubierto que la mayoría de los radioprotectores sintéticos, incluida la amifostina, poseen toxicidad. Esto llevó a los investigadores a desarrollar una novedosa, económicamente viable y eficiente alternativa terapéutica a la radioterapia. En las dos últimas décadas se ha observado un cambio importante hacia la investigación de productos naturales como radioprotectores, ya que son inmensamente eficaces en términos de su potencial bioequivalencia en relación con muchos de los compuestos sintéticos establecidos disponibles. Teniendo en cuenta las limitaciones de la radioterapia, hoy en día se utiliza un enfoque de "Oncología Integrativa" que implica una combinación de tratamiento médico tradicional y convencional para tratar a pacientes que padecen cáncer y trastornos mentales y psicológicos asociados.

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ANTECEDENTES: Las unidades de Cardiología intervencional han evidenciado un número creciente de procedimientos, cada vez más variados y complejos, lo cual podría eventualmente generar daños a los profesionales ocupacionalmente expuestos a radiaciones ionizantes (POEs) de no contar con los adecuados elementos de radioprotección y un uso correcto de ellos. OBJETIVO: Caracterizar la disponibilidad y utilización de los elementos de radioprotección y dosimetría de unidades de cardiología intervencionista de centros Sudamericanos. MATERIAL Y MÉTODOS: Se realizó una encuesta autoaplicada a 139 POEs, de ambos sexos de 7 países, a través de una plataforma on-line, se les consultó sobre características demográficas, dosimétricas y de radioprotección. RESULTADOS: Los elementos de radioprotección más tradicionales; delantales y cuellos plomados se utilizaron un 99,5 % y 98,4 % respectivamente, aquellos elementos más recientes como gafas, gorros y paños plomados solo alcanzaron un 36,8 %, 6,8 % y 34,2%, de utilización respectivamente, en cuanto a la utilización de los dosímetros, solo un 7,9 % lo hace apegado a las normas de la Organización Internacional de Energía Atómica (OIEA). CONCLUSIÓN: Se constató en la muestra analizada una falta de elementos de radioprotección y un uso inadecuado de ellos, urge realizar intervenciones educativas y técnicas para mejorar estos datos.

BACKGROUND: Due to the increasing number of interventional cardiology procedures currently performed, health professionals (POE) are exposed to ionizing radiation unless adequate protective elements are used. AIM: to describe the use of radioprotection elements and dosimetry in interventional cardiology laboratories in South America. METHODS: A self-administered survey was performed on 139 POE of both sexes and 7 countries using an online platform. Demographic data, dosimetry and characteristics of radioprotection analyzed. RESULTS: Commonly used radioprotective elements (lead aprons and collars) were used in 99.5% and 98% respectively. Recently introduced protection elements like lead goggles, caps and drapery were used in 36.8, 6.8 and 34.2% , respectively. Dosimetry according to the International Atomic Energy Commission (OIAE) was performed in only 7.9% of the procedures. CONCLUSION: there is a severe lack of adequate radioprotection during interventional cardiology procedures. Urgent measures, including technical implementation and educational interventions are needed to improve radioprotection in interventional cardiology.

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A mine in an area of naturally occurring radioactive materials (NORM), characterized by acid mine drainage, generates effluents with natural radionuclide concentrations, usually above the limits authorized by the regulator. The plant exploiting NORM controls the water quality and discharges it into the aquatic environment after meeting technical requirements. Downstream, water usage is unrestricted. In order to reach activity concentrations in the released effluents below the authorized values, the facility applies a chemical treatment to the effluent. Then, to ensure the effectiveness of the treatment, the facility performs sampling of treated effluent and determines the activity concentration of natural radionuclides (Unat, 226Ra, and 210Pb from the uranium series and 232Th and 228Ra from the thorium series). In the current study, the proportion and distribution of these radionuclides between the soluble and particulate fractions were determined. The measured activity concentrations were compared with the values proposed by the World Health Organization and Brazilian legislation, as well as other authorities, as regards the potable use from the radioprotection point of view. It was observed that the radionuclides are not in secular equilibrium. The fractions contribute differently to the total release of radionuclide, and there is no linear relationship between the fractions. The average activity concentrations did not result in radiological restrictions to water use, and the committed effective dose due to ingestion was estimated at 0.06 mSv y-1. Therefore, there is no radiological restriction to water use, since the dose which was found was below the constraint value for the public.

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Entre los escasos radioprotectores en uso, la amifostina resulta eficaz para reducir la toxicidad aguda inducida por la radiación ionizante. Sin embargo, presenta efectos tóxicos importantes que impiden su uso repetido o en dosis altas. Es necesario entonces desarrollar radioprotectores menos tóxicos, por sí mismos o como coadyuvantes de la amifostina en dosis bajas. Se expusieron ratas Sprague-Dawley a una dosis de rayos X de 6 Gy (cuerpo entero). Se ensayó el butirato de sodio como mitigante luego de una dosis baja de amifostina previa a la irradiación. A distintos tiempos después de la irradiación se realizó el recuento de eritrocitos, leucocitos y la fórmula leucocitaria. Los efectos genotóxicos se evaluaron en leucocitos de sangre mediante el ensayo Cometa. Se realizaron también estudios de supervivencia a 60 días y la evaluación histológica del duodeno e intestino grueso. El efecto del tratamiento resultó moderadamente protector respecto de la recuperación de los valores normales de eritrocitos, leucocitos y la fórmula leucocitaria en los animales sobrevivientes en ambos sexos, así como de los epitelios intestinales y el ADN de los leucocitos. También aumentó significativamente la sobrevida a 60 días. La radioprotección con amifostina en una dosis baja seguida de una mitigación con butirato fue claramente significativa.

Among the few radioprotectors in use, amifostine is effective in reducing the acute toxicity induced by ionizing radiation. However, it has important toxic effects that prevent its repeated use or in high doses. It is necessary then to develop less toxic radioprotectors, by themselves or as adjuvants of amifostine in low doses. Sprague-Dawley rats were exposed to an X-ray dose of 6 Gy (whole body). Sodium butyrate was tested as a mitigant after a low dose of amifostine prior to irradiation. At different times after the irradiation, the erythrocytes, leukocytes and the leukocyte formula were counted. Genotoxic effects were evaluated in blood leukocytes by the Comet assay. Sixty-day survival studies and histological evaluation of the duodenum and large intestine were also performed. The effect of the treatment was moderately protective with respect to the recovery of the normal values of erythrocytes, leukocytes and the leukocyte formula in the surviving animals in both sexes as well as for the intestinal epithelia and leukocytes DNA. It also significantly increased the 60-day survival. The radioprotection with amifostine in a low dose followed by mitigation with butyrate was clearly significant.

Entre os poucos radioprotetores em uso, a amifostina é eficaz na redução da toxicidade aguda induzida pela radiação ionizante. No entanto, tem importantes efeitos tóxicos que impedem seu uso repetido ou em altas doses. É necessário, então, desenvolver radioprotetores menos tóxicos, isoladamente ou como coadjuvantes da amifostina em baixas doses. Ratos Sprague-Dawley foram expostos a uma dose de raios X de 6 Gy (corpo inteiro). O butirato de sódio foi testado como mitigante após uma dose baixa de amifostina antes da irradiação. Em diferentes momentos após a irradiação, os eritrócitos, leucócitos e a fórmula de leucócitos foram contados. Os efeitos genotóxicos foram avaliados em leucócitos de sangue pelo ensaio Cometa. Estudos de sobrevida de 60 dias e avaliação histológica do duodeno e do intestino grosso também foram realizados. O efeito do tratamento resultou moderadamente protetor em relação à recuperação de valores normais de eritrócitos, leucócitos e fórmula leucocitária nos animais sobreviventes em ambos os sexos, bem como protegeu epitélios intestinais e o DNA dos leucócitos. Também aumentou significativamente a sobrevida para 60 dias. A radioproteção com amifostina em baixa dose seguida de uma mitigação com butirato foi claramente significativa.

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Purpose: Radiotherapy is an effective tool for cancer control, but side effects on normal tissue limit its therapeutic effectiveness. Thus, the search for agents that may allow the use of high doses of radiation but exerting a differential protection to healthy tissue is of current concern. Resveratrol (3,5,4'-trihydroxy-trans-stilbene) (RSV) is a polyphenol with pleiotropic benefits for health due to its antioxidant and anti-inflammatory properties. Recent findings suggest that RSV could be promising in the fight against cancer since it inhibits the growth of tumor cells and optimizes radiotherapy. However, evidence in rodents and human beings is inconsistent. The aim of this study was to evaluate the radiomodulatory capacity of RSV on human lymphocytes. Materials and methods: To study these properties of RSV, human peripheral blood lymphocytes from 20 healthy women undergoing in vivo RSV treatment with 50 mg/day doses were irradiated. The genotoxic damage was assessed by the comet assay, also called single cell gel electrophoresis (it makes it possible to measure the extent of the DNA migration from individual cells, detecting the genomic damage present in each cell). Results: No differences were observed in basal clastogenic damage among samples without irradiation. There was only a slight radiation-induced clastogenic damage. The damage index (DI) value had a statistically significant increase in the exposed groups in comparison with the control groups (p < .0001), but a statistically significant decrease of the DI value was observed in samples irradiated after treatment with RSV compared to pretreatment samples (p < .0001). Conclusion: The RSV used as a dietary supplement had radioprotective properties, without exerting a cytotoxic effect. The potential utility of RSV to optimize the radiotherapeutic ratio in cancer treatments using radiotherapy should be considered.

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It is estimated that more than half of cancer patients undergo radiotherapy during the course of their treatment. Despite its beneficial therapeutic effects on tumor cells, exposure to high doses of ionizing radiation (IR) is associated with several side effects. Although improvements in radiotherapy techniques and instruments could reduce these side effects, there are still important concerns for cancer patients. For several years, scientists have been trying to modulate tumor and normal tissue responses to IR, leading to an increase in therapeutic ratio. So far, several types of radioprotectors and radiosensitizers have been investigated in experimental studies. However, high toxicity of chemical sensitizers or possible tumor protection by radioprotectors creates a doubt for their clinical applications. On the other hand, the protective effects of these radioprotectors or sensitizer effects of radiosensitizers may limit some type of cancers. Hence, the development of some radioprotectors without any protective effect on tumor cells or low toxic radiosensitizers can help improve therapeutic ratio with less side effects. Melatonin as a natural body hormone is a potent antioxidant and anti-inflammatory agent that shows some anti-cancer properties. It is able to neutralize different types of free radicals produced by IR or pro-oxidant enzymes which are activated following exposure to IR and plays a key role in the protection of normal tissues. In addition, melatonin has shown the ability to inhibit long-term changes in inflammatory responses at different levels, thereby ameliorating late side effects of radiotherapy. Fortunately, in contrast to classic antioxidants, some in vitro studies have revealed that melatonin has a potent anti-tumor activity when used alongside irradiation. However, the mechanisms of its radiosensitive effect remain to be elucidated. Studies suggested that the activation of pro-apoptosis gene, such as p53, changes in the metabolism of tumor cells, suppression of DNA repair responses as well as changes in biosynthesis of estrogen in breast cancer cells are involved in this process. In this review, we describe the molecular mechanisms for radioprotection and radiosensitizer effects of melatonin. Furthermore, some other proposed mechanisms that may be involved are presented.

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