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Background.Anecdotal reports are appearing in the scientific literature about cases of brain tumors in interventional physicians who are exposed to ionizing radiation. In response to this alarm, several designs of leaded caps have been made commercially available. However, the results reported on their efficacy are discordant.Objective.To synthesize, by means of a systematic review of the literature, the capacity of decreasing radiation levels conferred by radiation attenuating devices (RADs) at the cerebral level of interventional physicians.Methodology.A systematic review was performed including the following databases: MEDLINE, SCOPUS, EBSCO, Science Direct, Cochrane Controlled Trials Register (CENTRAL), WOS, WHO International Clinical Trials Register, Scielo and Google Scholar, considering original studies that evaluated the efficacy of RAD in experimental or clinical contexts from January 1990 to May 2023. Data selection and extraction were performed in triplicate, with a fourth author resolving discrepancies.Results.Twenty articles were included in the review from a total of 373 studies initially selected from the databases. From these, twelve studies were performed under clinical conditions encompassing 3801 fluoroscopically guided procedures, ten studies were performed under experimental conditions with phantoms, with a total of 88 procedures, four studies were performed using numerical calculations with a total of 63 procedures. The attenuation and effectiveness of provided by the caps analyzed in the present review varying from 12.3% to 99.9%, and 4.9% to 91% respectively.Conclusion.RAD were found to potentially provide radiation protection, but a high heterogeneity in the shielding afforded was found. This indicates the need for local assessment of cap efficiency according to the practice.

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O câncer de cabeça e pescoço (CCP) refere-se ao grupo de tumores que atingem a laringe, cavidade nasal, nasofaringe, orofaringe, cavidade oral e glândulas salivares. A radioterapia no paciente com CCP representa uma terapia para manutenção do órgão, através da destruição das células neoplásicas malignas. O objetivo do presente estudo foi identificar estratégias radioterápicas aplicadas ao paciente com CCP e seus respectivos efeitos colaterais em cavidade oral, além de investigar as principais modalidades utilizadas nos sistemas de saúde do Brasil. Tratou-se de uma revisão narrativa da literatura com busca ativa das bases eletrônicas PUBMED, LILACS e SCIELO. Após todas as etapas de refinamento, um total de 58 artigos foram incluídos na presente revisão. A radioterapia possui papel de destaque no tratamento do CCP. No entanto, por não ser um método terapêutico com alta especificidade, resulta em efeitos adversos ao tratamento como mucosite oral, trismo e disfunção salivar, que findam por reduzir a qualidade de vida do paciente. Dentre as principais técnicas radioterapêuticas utilizadas no Brasil, a IMRT e VMAT caracterizam-se como as formas mais avançadas da terapia em 3D, proporcionando doses equivalentes para cada área da lesão tumoral, poupando áreas teciduais circunvizinhas que não necessitam de irradiação. Além da toxicidade reduzida, uma maior sobrevida pode ser observada em pacientes tratados com essas técnicas. Um dos maiores desafios atuais na radioterapia contra o CCP é a proteção de tecidos saudáveis. Nesse sentido, a IMRT e VMAT apresentam superioridade em relação às demais técnicas.

Head and neck cancer (CCP) refers to the group of tumors that affect the larynx, nasal cavity, nasopharynx, oropharynx, oral cavity and salivary glands. Radiotherapy in patients with CCP represents a therapy for organ maintenance, through the destruction of malignant neoplastic cells. The aim of this study was to identify radiotherapy strategies applied to patients with CCP and their respective side effects in the oral cavity, and to investigate the main modalities used in health systems in Brazil. It was a narrative review of the literature with active search of electronic databases PUBMED, LILACS and SCIELO. After all stages of refinement, a total of 58 articles were included in this review. Radiotherapy has a prominent role in the treatment of CCP. However, because it is not a therapeutic method with high specificity, it results in adverse effects to treatment such as oral mucositis, trismus and salivary dysfunction, which end up reducing the quality of life of the patient. Among the main radiotherapeutic techniques used in Brazil, IMRT and VMAT are characterized as the most advanced forms of 3D therapy, providing equivalent doses for each area of the tumor sparing surrounding tissue areas that do not require irradiation. In addition to reduced toxicity, greater survival can be observed in patients treated with these techniques. One of the biggest current challenges in radiation therapy against CCP is the protection of healthy tissues. In this sense, the IMRT and VMAT present superiority in relation to the other techniques.

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Objective We aim to describe an experimental model for studying femoral fractures in rats after exposure to ionizing radiation, demonstrating a way to apply a substance for analysis, the method for patterning fracture and irradiation, and how to evaluate its effectiveness based on radiographic studies. Methods We used 24 rats divided into 2 groups of 12 animals each. The STUDY group was exposed to ionizing radiation and treated with saline solution, and the CONTROL group was not exposed to radiation and was treated with saline solution. All animals were subjected to standardized fracture of the right femur that was fixed with intramedullary wire. The efficiency of the bone union was assessed by radiographic exam. Results Fracture healing was more efficient in bones not exposed to ionizing radiation ( p = 0.012). All fractures met the criteria of being simple, diaphyseal, transverse or short oblique. Conclusion The experimental model presented is an efficient alternative for the study of fractures in irradiated bones in rats.

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Abstract Objective We aim to describe an experimental model for studying femoral fractures in rats after exposure to ionizing radiation, demonstrating a way to apply a substance for analysis, the method for patterning fracture and irradiation, and how to evaluate its effectiveness based on radiographic studies. Methods We used 24 rats divided into 2 groups of 12 animals each. The STUDY group was exposed to ionizing radiation and treated with saline solution, and the CONTROL group was not exposed to radiation and was treated with saline solution. All animals were subjected to standardized fracture of the right femur that was fixed with intramedullary wire. The efficiency of the bone union was assessed by radiographic exam. Results Fracture healing was more efficient in bones not exposed to ionizing radiation (p = 0.012). All fractures met the criteria of being simple, diaphyseal, transverse or short oblique. Conclusion The experimental model presented is an efficient alternative for the study of fractures in irradiated bones in rats.

Resumo Objetivo Nosso objetivo é descrever um modelo experimental para estudo de fraturas de fêmur em ratos após exposição a radiação ionizante, demonstrando uma forma de aplicação de uma substância para análise, o método de padronização de fratura e irradiação e a forma de avaliação de sua eficácia com base em estudos radiográficos. Métodos Utilizamos 24 ratos divididos em dois grupos de 12 animais cada. O grupo ESTUDO foi exposto à radiação ionizante e tratado com soro fisiológico, enquanto o grupo CONTROLE não foi exposto à radiação e foi tratado com soro fisiológico. Todos os animais foram submetidos à fratura padronizada do fêmur direito e sua fixação com fio intramedular. A eficácia da consolidação óssea foi determinada por exame radiográfico. Resultados A cicatrização de fraturas foi mais eficiente em ossos não expostos à radiação ionizante (p = 0,012). Todas as fraturas atenderam aos critérios de serem simples, diafisárias, transversas ou oblíquas curtas. Conclusão O modelo experimental apresentado é uma boa alternativa para o estudo de fraturas em ossos irradiados em ratos.

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Abstract Background Various studies are ongoing related to the radioprotective agents. Herbal preparations are currently becoming popular because of their beneficial effects with fewer side effects compared to the synthetic/semi-synthetic medicines, and Nigella sativa oil (NSO) is only one of them. Objective To investigate NSO for its antioxidant effects on the heart tissue of rats exposed to ionizing radiation (IR). Methods Thirty six male albino Wistar rats, divided into four groups, were designated to group I (IR plus NSO group) that received both 5 Gray of gamma IR to total cranium and NSO; group II (IR alone group) that received IR plus saline, group III (control group of NSO) that received saline and did not receive NSO or IR; group IV (control group) that received only sham IR. Alterations in Total antioxidant status (TAS) and Total oxidant status (TOS), Oxidative stres index (OSI), Sulhydryl group (SH), Lipid hydroperoxide (LOOH), Paraoxonase (PON) levels, Arylesterase (ARE) and Ceruloplasmin (CER) activities in homogenized heart tissue of rats were measured by biochemical methods. Results In heart tissue of the rats in the IR alone group (group II) LOOH, TOS and OSI levels were found to be higher, ARE activity and TAS level were found to be lower than all of the other groups (p < 0.01). These results also support that IR increases oxidative stress and NSO's protective effect. Conclusion NSO would reduce the oxidative damage in the irradiated heart tissue in the experimental rat model.

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In this study, the thermoluminescence (TL) properties of natural NaCl from Lluta, Arequipa-Peru was investigated. The number of peaks and the kinetic parameters associated with the TL glow peaks of NaCl sample after gamma-irradiation were analyzed by initial rise and deconvolution method. Defect centers induced in pure salt by gamma irradiation have been studied by electron spin resonance (ESR) with a view to identify the centers associated with the TL process in the salt. Thermal annealing experiments indicate the presence of three defect centers. Center I characterized by the g-value 2.011 is identified as an O- ion and relates with the dominant TL peak at 220 °C. Center II with a g-value of 2.0058 is attributed to a F center and is found to correlate with the 128 °C TL peak. Center III has of g-value 2.014 and is also assigned to an O- ion.

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RESUMEN El devenir de la ciencia contemporánea reclama de una conciencia moral y de una ética para la ciencia, la asunción de sentimientos, valores, normas, deberes y responsabilidades para el obrar y el quehacer científico en particular para los profesionales implicados en el uso de las radiaciones ionizantes. El presente trabajo tiene como objetivo realizar una revisión bibliográfica sobre las consideraciones bioéticas relacionados con el uso de las radiaciones ionizantes como expresión del desarrollo científico-tecnológico, para contribuir a elevar la responsabilidad social en su uso en el Servicio de Imagenología del Hospital Provincial General Docente "Dr. Antonio Luaces Iraola" de Ciego de Ávila. Para la obtención de la información se efectuó una búsqueda en bases de datos bibliográficas de 2015-2019, en literatura científica de la BVS de Cuba como PubMed/Medline y Lilacs. Se consultaron fuentes de información disponibles a texto completo como SciELO Cuba y Ebsco. Se sistematizan los conocimientos relacionados con las insuficiencias detectadas en relación con la falta de percepción social sobre los riesgos que implica la radiación ionizante para la salud de los pacientes, familiares, trabajadores expuestos, así como para el medio ambiente por falta de una adecuada Cultura de Seguridad Radiológica.

ABSTRACT The future of contemporary science calls for a moral conscience and ethics for science, the assumption of feelings, values, norms, duties and responsibilities for the work and scientific work in particular for professionals involved in the use of radiation ionizing. The objective of this work is to carry out a bibliographic review on the bioethical considerations related to the use of ionizing radiation as an expression of scientific-technological development, to contribute to raising social responsibility in its use in the Imaging Service of the Provincial General Teaching Hospital "Dr. Antonio Luaces Iraola" of Ciego de Ávila. To obtain the information, a search was carried out in bibliographic databases from 2015-2019, in the scientific literature of the Cuban VHL such as PubMed/Medline and Lilacs. Information sources available in full text, such as SciELO Cuba and Ebsco, were consulted. The knowledge related to the insufficiencies detected in relation to the lack of social perception about the risks that ionizing radiation implies for the health of patients, relatives, exposed workers, as well as for the environment due to lack of an adequate Culture of Radiological safety.

RESUMO O futuro da ciência contemporânea exige uma consciência moral e ética para a ciência, a assunção de sentimentos, valores, normas, deveres e responsabilidades pelo trabalho e trabalho científico em particular para os profissionais envolvidos no uso das radiações. O objetivo deste trabalho é realizar uma revisão bibliográfica sobre as considerações bioéticas relacionadas ao uso de radiações ionizantes como expressão do desenvolvimento científico-tecnológico, para contribuir para aumentar a responsabilidade social em seu uso no Serviço de Imagiologia do Hospital Geral de Ensino Provincial "Dr. Antonio Luaces Iraola" de Ciego de Ávila. Para obter as informações, foi realizada uma busca em bases de dados bibliográficas de 2015-2019, na literatura científica da BVS cubana como PubMed/Medline e Lilacs. Foram consultadas fontes de informação disponíveis em texto completo, como SciELO Cuba e Ebsco. O conhecimento relacionado às insuficiências detectadas em relação à falta de percepção social sobre os riscos que a radiação ionizante implica para a saúde de pacientes, familiares, trabalhadores expostos, bem como para o meio ambiente devido à falta de uma adequada Cultura de segurança radiológica.

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The spin activity in macromolecules such as DNA and oligopeptides, in the context of the chiral induced spin selectivity has been proposed to be due to the atomic spin-orbit coupling (SOC) and the associated chiral symmetry of the structures. This coupling, associated with carbon, nitrogen and oxygen atoms in biological molecules, albeit small (meV), can be enhanced by the geometry, and strong local polarization effects such as hydrogen bonding. A novel way to manipulate the spin degree of freedom is by modifying the spectrum using a coupling to the appropriate electromagnetic radiation field. Here we use the Floquet formalism in order to show how the half filled band Hamiltonian for DNA, can be modulated by the radiation to produce up to a tenfold increase of the effective SOC once the intrinsic coupling is present. On the other hand, the chiral model, once incorporating the orbital angular momentum of electron motion on the helix, opens a gap for different helicity states (helicity splitting) that chooses spin polarization according to transport direction and chirality, without breaking time reversal symmetry. The observed effects are feasible in physically reasonable parameter ranges for the radiation field amplitude and frequency.

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PURPOSE: A new type of electronic dosimeter is presented, capable of discerning between the doses of gamma photons and neutrons in a mixed beam as found in boron neutron capture therapy (BNCT). We introduce a real-time dosimeter based on a thick gate field oxide field effect transistor (FOXFET) covered with a neutron converter layer containing gadolinium. METHODS: To sensitize the FOXFET dosimeter to neutron fluxes, a converter layer containing gadolinium oxide particles embedded in photoresines was deposited over the sensor surface. Mixed neutron-gamma field configurations with different neutron energy spectra were used to assess the FOXFET response, considering different thicknesses of the neutron converter layer. RESULTS: The total gamma sensitivity of the devices resulted to be 43 mV/Gy. The responses of sensors with different converter layer thicknesses irradiated with different neutron spectra are simulated using GEANT4 code. The response to photons is not significantly modified with thin conversion layers when used in water medium. CONCLUSIONS: A real-time dosimeter comprising a pair of FOXFET sensors-only one of them with a gadolinium neutron converter layer-allows the simultaneous measurement of gamma dose and neutron flux during BNCT irradiations.

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PURPOSE: This study aimed to summarize the impact of neck and head radiation treatment on maxillofacial structures detected on panoramic radiographs. MATERIALS AND METHODS: In this systematic review, the authors searched PubMed Central, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar for original research studies up to February 2020 that included the following Medical Subject Headings keywords: words related to "radiotherapy" and synonyms combined with keywords related to "panoramic radiography" and "oral diagnosis" and synonyms. Only original studies in English that investigated the maxillofacial effects of radiotherapy via panoramic radiographs were included. The quality of the selected manuscripts was evaluated by assessing the risk of bias using Cochrane's ROBINS-I tool for non-randomized studies. RESULTS: Thirty-three studies were eligible and included in this review. The main objectives pertained to the assessment of the effects of radiation on maxillofacial structures, including bone architecture alterations, periodontal space widening, teeth development abnormalities, osteoradionecrosis, and implant bone loss. The number of participants evaluated ranged from 8 to 176. CONCLUSION: The interaction between ionizing radiation and maxillofacial structures results in hazard to the tissues involved, particularly the bone tissue, periosteum, connective tissue of the mucosa, and endothelium. Hard tissue changes due to radiation therapy can be detected on panoramic radiographs.

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RESUMEN Objetivos: Evaluar la actividad fotoprotectora de una crema con extracto acuoso liofilizado de maca (ELM) frente a la irradiación ultravioleta (UV) en la piel de ratones. Materiales y métodos: Se realizó un estudio experimental en 35ratones BALB/c. Los tratamientos fueron aplicados por vía tópica en el dorso de los animales y posteriormente irradiados con rayos ultravioleta B, para luego medir el grosor en micras (µm) de muestras histológicas de la piel de los ratones. Se asignaron siete grupos divididos en no irradiado: blanco (G1) e irradiados con luz UV: sin tratamiento (G2); con protector solar comercial con factor de protección solar (FPS) 30 (G3); crema (placebo) (G4); ELM al 15% en agua (G5); ELM al 5% en crema (G6); y ELM al 15% en crema (G7). Se determinó el FPS in vitro, mediante el método de Mansur. Se realizaron las lecturas de las absorbancias en un espectrofotómetro ultravioleta-visible (UV-VIS) y se determinaron los FPS para las siguientes formulaciones: ELM al 5% en crema, benzofenona-4 (BZF-4) y bloqueador solar comercial FPS 30. Resultados: El grosor de piel de ratón en micras (µm) fue de 27,28 en G2; 18,31 en G3; 27,33 en G4; 19,51 en G5 y 18,04 en G6; no hubo diferencia significativa entre el grupo no expuesto a la radiación (G1) y el grupo ELM al 15% en crema (G7), ambos presentaron los menores grosores (12,76 y 14,20 µm, respectivamente). El FPS de ELM al 15% en crema fue 5,480 ± 0,020. Conclusiones: La formulación con ELM en crema presentó actividad fotoprotectora frente a la irradiación UV, los alcaloides fueron los componentes fitoquímicos mayormente encontrados y la formulación fue compatible con el activo (ELM).

ABSTRACT Objectives: To evaluate the photoprotective activity of a cream with lyophilized aqueous extract of maca (LEM) against ultraviolet (UV) irradiation in the skin of mice. Materials and methods: An experimental study was carried out on 35 BALB/c mice. Treatment was applied topically on the dorsum of the animals, which were subsequently irradiated with ultraviolet B rays, and then we measured the thickness in microns (μm) of histological samples of the skin of the mice. Seven groups were assigned, divided into non-irradiated: Blank (G1) and irradiated with UV light: no treatment (G2); with commercial sunscreen with sun protection factor (SPF) 30 (G3); cream (placebo) (G4); LEM at 15% in water (G5); LEM cream at 5% (G6); and LEM cream at 15% (G7). In vitro SPF was determined using the Mansur method. Absorbance readings were taken in an ultraviolet- visible spectrophotometer (UV-VIS) and SPFs were determined for the following formulations: LEM cream at 5%, benzophenone-4 (BZF-4) and commercial sunscreen SPF 30. Results: Mouse skin thickness in microns (μm) was 27.28 in G2; 18.31 in G3; 27.33 in G4; 19.51 in G5 and 18.04 in G6. There was no significant difference between the group not exposed to radiation (G1) and the 15% LEM cream group (G7), both had the lowest thicknesses (12.76 and 14.20 μm, respectively). The SPF of LEM cream at 15% was 5.480 ± 0.020. Conclusions: The formulation with LEM cream showed photoprotective activity against UV irradiation, alkaloids were the phytochemical components mostly found and the formulation was compatible with the active principle (LEM).

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Introduction: sunscreen is a cosmetic used to protect human skin from the deleterious effects of UV radiation and thus minimize the risks of developing skin cancer. Extracts produced from fruits, such as Abiu, Guava, Rambutan and Grape, have significant concentrations of chromophores and phenolic substances that have the ability to absorb UV light and neutralize free radicals. The production of cosmetics from naturally occurring substances with such activities will be of great importance for Brazilian industry and could reduce the cost of production, given the large existing biodiversity in the country. Objectives: carry out a patent search for formulations and cosmetic products that contains phenolic rich fruit extracts as photoprotective and antioxidant bioactives. Methodology: a survey of patents was carried out in the database of the National Institute of Intellectual Property (INPI) and the European Patent Office (EPO), covering a time period between 2008 and 2018, using a combination of keywords related to herbal cosmetics and sunscreens. Results: this research identifies a significant number of patents related to plant extract in association with sunscreen product, however, no patent filings were identified for cosmetic products containing extracts of the evaluated fruits, either alone or in combination, for photoprotective and antioxidant purposes. Conclusion: the Brazilian and international market for sun care products moves millions to billions of dollars annually and have a significant annual growth prospect. Considering the great biodiversity existing in the country, the production of cosmetics from naturally occurring substances with such activities will be of great importance for the Brazilian industrial sector.

Introdução: os filtros solares são cosméticos usados para proteger a pele humana dos efeitos deletérios da radiação UV e assim, minimizar os riscos de desenvolvimento de câncer de pele. Extratos produzidos a partir de frutos, como Abiu, Goiaba, Rambutan e Uva, têm concentrações significativas de cromóforos e substâncias fenólicas que têm a capacidade de absorver a radiação UV e neutralizar os radicais livres. A produção de cosméticos a partir de substâncias naturais com essas atividades será de grande importância para a indústria brasileira e poderá reduzir o custo de produção, dada a grande biodiversidade existente no país. Objetivos: realizar uma busca de registros de patentes de formulações e produtos cosméticos que contêm extratos de frutos ricos em fenólicos como bioativos fotoprotetores e antioxidantes. Metodologia: foi realizado um levantamento de patentes no banco de dados do Instituto Nacional de Propriedade Intelectual (INPI) e do Escritório Europeu de Patentes (EPO), abrangendo um período de tempo entre 2008 e 2018, utilizando uma combinação de palavras-chave relacionadas a cosméticos à base de plantas e protetores solares. Resultados: esta pesquisa identificou um número significativo de patentes relacionadas ao extrato de plantas em associação ao produto protetor solar, no entanto, não foram identificados pedidos de patente para produtos cosméticos que contenham extratos das frutas avaliadas, isoladamente ou em combinação, para fins fotoprotetores e antioxidantes. Conclusão: o mercado brasileiro e internacional de produtos de proteção solar movimenta milhões a bilhões de dólares anualmente e tem a perspectiva de crescimento anual significativa. Considerando a grande biodiversidade existente no país, a produção de cosméticos a partir de substâncias naturais com essas atividades será de grande importância para o setor industrial brasileiro.

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PURPOSE: The aim of this study was to evaluate the distribution of acute clinical complications that involve the oral cavity (oral mucositis and salivary flow), general health status (Karnofsky performance status scale (KPS) and weight), and quality of life using the worst performance throughout radiotherapy treatment by intensity-modulated radiation therapy (IMRT) in the head and neck region and to evaluate the correlation between these variables. METHODS: This prospective, longitudinal study evaluated 32 patients who were undergoing IMRT for head and neck tumors. The measures were collected weekly through standardized protocols and a quality of life questionnaire (UW-QOL version 4). RESULTS: The worst performance for all variables was concentrated in treatment weeks 2 and 5. Regarding quality of life, the emotional dimensions were the most affected (pain 62.86; activity 55; recreation 43.57; mood 49.97; shoulder 57.06; anxiety 42.91). There were a higher number of moderate mucositis correlations with quality of life (mucositis × KPS 0.002; mucositis × weight loss 0.03; mucositis × pain 0.001; mucositis × activity 0.002; mucositis × recreation 0.001; mucositis × swallowing 0.002; mucositis × saliva 0.006; mucositis × mood 0.007; mucositis × anxiety 0.002). CONCLUSIONS: IMRT treatment severely deteriorated the patients' quality of life. There were important correlations between the clinical variables and quality of life, especially mucositis.

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Abstract The well-known occurrence of Chagas disease in endemic areas has become a worldwide problem, and cardiac magnetic resonance allows the early detection of cardiac involvement and complications of this disease. Cardiac magnetic resonance is a useful tool in all phases of Chagas disease, and new promising techniques using T1 mapping and extracellular volume measurements are able to detect cardiac involvement even earlier than conventional techniques.

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In recent decades, there has been a significant increase in the number of imaging examinations performed on pregnant patients. That increase has occurred across the various modalities, including ultrasound, computed tomography, and magnetic resonance imaging. However, little is known about the risks that these examinations generate for the mother and fetus, related to the use of ionizing radiation or the use of contrast media. When pregnant patients are submitted to imaging studies, the principles of protection established by the International Commission on Radiological Protection should always be respected, to avoid injury to the pregnant woman and the fetus. The potential deleterious effects on the fetus must be weighed against the damage caused by not performing an examination that is clearly indicated, given that a delayed or missed diagnosis can be even more harmful to the health of the mother and of the fetus itself. The purpose of this review article is to address concerns regarding the safety of imaging methods used during pregnancy, as well as to identify typical clinical situations that require decisions to be made about the indication and optimal planning of imaging examinations.

Nas últimas décadas observou-se um aumento expressivo no número de exames de imagem realizados em pacientes gestantes. Este aumento inclui diferentes modalidades, como a ultrassonografia, a tomografia computadorizada e a ressonância magnética. Entretanto, ainda se sabe pouco sobre os riscos que esses exames geram para o binômio mãe-feto, seja no contexto da utilização de radiação ionizante ou da utilização de diferentes meios de contraste. Ao se submeter pacientes grávidas a estudos por imagem, deve-se sempre respeitar os princípios de limitação do uso estabelecidos pela Comissão Internacional de Proteção Radiológica, visando a poupar a gestante e o feto de danos evitáveis. Ressalta-se que os potenciais efeitos deletérios sobre o feto se contrapõem aos danos causados pela não realização de um exame bem indicado, já que um diagnóstico protelado ou perdido pode ser ainda mais nocivo para a saúde materna e do próprio concepto. O objetivo deste artigo de revisão é esclarecer dúvidas sobre a segurança dos métodos de imagem durante o período gestacional, bem como identificar situações clínicas típicas que exigem decisões sobre a indicação e o planejamento otimizado dos exames de imagem.

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Abstract In recent decades, there has been a significant increase in the number of imaging examinations performed on pregnant patients. That increase has occurred across the various modalities, including ultrasound, computed tomography, and magnetic resonance imaging. However, little is known about the risks that these examinations generate for the mother and fetus, related to the use of ionizing radiation or the use of contrast media. When pregnant patients are submitted to imaging studies, the principles of protection established by the International Commission on Radiological Protection should always be respected, to avoid injury to the pregnant woman and the fetus. The potential deleterious effects on the fetus must be weighed against the damage caused by not performing an examination that is clearly indicated, given that a delayed or missed diagnosis can be even more harmful to the health of the mother and of the fetus itself. The purpose of this review article is to address concerns regarding the safety of imaging methods used during pregnancy, as well as to identify typical clinical situations that require decisions to be made about the indication and optimal planning of imaging examinations.

Resumo Nas últimas décadas observou-se um aumento expressivo no número de exames de imagem realizados em pacientes gestantes. Este aumento inclui diferentes modalidades, como a ultrassonografia, a tomografia computadorizada e a ressonância magnética. Entretanto, ainda se sabe pouco sobre os riscos que esses exames geram para o binômio mãe-feto, seja no contexto da utilização de radiação ionizante ou da utilização de diferentes meios de contraste. Ao se submeter pacientes grávidas a estudos por imagem, deve-se sempre respeitar os princípios de limitação do uso estabelecidos pela Comissão Internacional de Proteção Radiológica, visando a poupar a gestante e o feto de danos evitáveis. Ressalta-se que os potenciais efeitos deletérios sobre o feto se contrapõem aos danos causados pela não realização de um exame bem indicado, já que um diagnóstico protelado ou perdido pode ser ainda mais nocivo para a saúde materna e do próprio concepto. O objetivo deste artigo de revisão é esclarecer dúvidas sobre a segurança dos métodos de imagem durante o período gestacional, bem como identificar situações clínicas típicas que exigem decisões sobre a indicação e o planejamento otimizado dos exames de imagem.

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To report a treatment of radiation retinopathy in a patient exposed to ionizing radiation for a period of 2 years. A 26-year-old female patient with no comorbidities diagnosed with myelodysplasia confirmed by bone marrow biopsy. She presented a complaint of bilateral progressive visual acuity reduction. At the ophthalmologic examination, she presented alterations suggestive of radiation retinopathy as well as macular thickness to optical coherence tomography (OCT) of over 500 µm. The patient underwent intravitreal injection (0.05 mL) of ranibizumab (Lucentis®) monthly in both eyes and follow-up through visual acuity and OCT examination. She presented reduction of macular edema as well as a slight improvement of visual acuity. In this case, the treatment of radiation retinopathy with intravitreal injection of ranibizumab (Lucentis) was relatively useful, with a slight improvement of visual acuity, due to the regression of macular edema, not being curative.

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SUMMARY OBJECTIVE: To evaluate the epidemiological data and available treatments for fractures secondary to radiotherapy treatment. METHODS: Identification of publications on pathological skeletal fractures previously exposed to ionizing radiation. RESULTS: The incidence of fractures after irradiation varies from 1.2% to 25% with a consolidation rate of 33% to 75%, being more frequent in the ribs, pelvis, and femur. The time elapsed between irradiation and fracture occurs years after radiotherapy. Risk factors include age above 50 years, female gender, extensive periosteal detachment, circumferential irradiation, tumor size, and anterior thigh location. The etiology is still uncertain, but cellular disappearance, reduction of bone turnover and activity were observed hematopoietic as possible causes of failure of consolidation. CONCLUSION: There is no consensus in the literature on the factors related to the development of fractures, with radiation dose, previous tumor size and periosteal detachment being suggested as potential factors.

RESUMO OBJETIVO: Avaliar dados epidemiológicos e tratamentos disponíveis para fraturas secundárias ao tratamento radioterápico. MÉTODOS: Identificação de publicações sobre as fraturas patológicas ocorridas em esqueleto previamente exposto à radiação ionizante. RESULTADOS: A incidência de fraturas após irradiação varia de 1,2% a 25% com taxa de consolidação de 33% a 75%, sendo mais frequente em costelas, pelve e fêmur. O tempo decorrido entre a irradiação e a fratura ocorre anos após a radioterapia. Os fatores de risco incluem idade acima de 50 anos, sexo feminino, descolamento periosteal extenso, irradiação circunferencial, tamanho do tumor e localização anterior na coxa. A etiologia ainda é incerta, mas foram observados desaparecimento celular, redução do turnover ósseo e da atividade hematopoiética como possíveis causas da falha de consolidação. CONCLUSÃO: Não há consenso na literatura avaliada sobre os fatores relacionados ao desenvolvimento de fraturas, sendo a dose de radiação, o tamanho prévio do tumor e o descolamento periosteal sugeridos como fatores potenciais.

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Abstract Background: Mercury's deleterious effects are associated with increased cardiovascular risk. Objective: To determine whether chronic exposure to inorganic mercury increases the activity of angiotensin-converting enzyme and its relationship with oxidative stress in several organs and tissues. Methods: We studied male Wistar and spontaneously hypertensive rats (SHR) (3-month-old) exposed or not to HgCl2 for 30 days. At the end of treatment, we investigated the following: changes in body weight, hemodynamic parameters, angiotensin-converting enzyme (ACE) activity and oxidative stress in the heart, aorta, lung, brain and kidney in hypertensive compared to normotensive animals. A value of p < 0.05 was considered significant. Results: Chronic exposure to HgCl2 did not affect weight gain in either group. Systolic blood pressure, measured weekly, did not increase in Wistar rats but showed a small increase in SHR rats. We also observed increases in left ventricular end-diastolic pressure and ACE activity in the plasma and hearts of normotensive rats. In the SHR+Hg group, ACE activity increased in plasma but decreased in kidney, lung, heart, brain and aorta. Oxidative stress was assessed indirectly by malondialdehyde (MDA) production, which increased in Hg-treated rats in both plasma and heart. In the SHR+Hg group, MDA increased in heart and aorta and decreased in lungs and brain. Conclusion: These results suggest that chronic exposure to inorganic mercury aggravates hypertension and produces more expressive changes in ACE activity and oxidative stress in SHRs. Such exposure affects the cardiovascular system, representing a risk factor for the development of cardiovascular disorders in normotensive rats and worsening of pre-existing risks for hypertension.

Resumo Fundamento: Os efeitos deletérios do mercúrio estão associados ao risco cardiovascular aumentado. Objetivo: Determinar se a exposição crônica ao mercúrio inorgânico aumenta a atividade da enzima conversora de angiotensina e sua relação com o estresse oxidativo em vários órgãos e tecidos. Métodos: Estudamos ratos Wistar e ratos espontaneamente hipertensos (SHR) (3 meses de idade) expostos ou não a HgCl2 por 30 dias. Ao final do tratamento, investigamos: alterações de peso, parâmetros hemodinâmicos, atividade da enzima conversora de angiotensina (ECA) e estresse oxidativo no coração, aorta, pulmão, cérebro e rim de animais hipertensos comparados a animais normotensos. Um valor de p < 0,05 foi considerado significativo. Resultados: A exposição crônica ao HgCl2 não afetou o ganho de peso em nenhum dos grupos. A pressão arterial sistólica, medida semanalmente, não aumentou em ratos Wistar, mas mostrou um pequeno aumento nos ratos SHR. Também observamos aumentos na pressão diastólica final do ventrículo esquerdo e na atividade da ECA no plasma e no coração de ratos normotensos. No grupo SHR + Hg, a atividade da ECA aumentou no plasma, mas diminuiu no rim, pulmão, coração, cérebro e aorta. O estresse oxidativo foi avaliado indiretamente pela produção de MDA, que aumentou nos ratos tratados com Hg tanto no plasma quanto no coração. No grupo SHR + Hg, o MDA aumentou no coração e na aorta e diminuiu nos pulmões e no cérebro. Conclusão: Estes resultados sugerem que a exposição crônica ao mercúrio inorgânico agrava a hipertensão e produz mudanças mais expressivas na atividade da ECA e no estresse oxidativo em SHRs. Essa exposição afeta o sistema cardiovascular, representando um fator de risco para o desenvolvimento de distúrbios cardiovasculares em ratos normotensos e para piorar riscos pré-existentes para hipertensão.

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