RESUMO
According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry.
Assuntos
Lesões por Radiação/diagnóstico , Liberação Nociva de Radioativos/estatística & dados numéricos , Radiometria/métodos , Pele/efeitos da radiação , Brasil/epidemiologia , Chile/epidemiologia , Espectroscopia de Ressonância de Spin Eletrônica , Traumatismos dos Dedos/etiologia , Traumatismos da Mão/etiologia , Humanos , Medições Luminescentes , Doses de Radiação , Exposição à Radiação/efeitos adversos , Lesões por Radiação/epidemiologiaRESUMO
According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry.
Assuntos
Humanos , Lesões por Radiação/diagnóstico , Liberação Nociva de Radioativos/estatística & dados numéricos , Radiometria/métodos , Pele/efeitos da radiação , Brasil/epidemiologia , Chile/epidemiologia , Espectroscopia de Ressonância de Spin Eletrônica , Traumatismos dos Dedos/etiologia , Traumatismos da Mão/etiologia , Medições Luminescentes , Doses de Radiação , Exposição à Radiação/efeitos adversos , Lesões por Radiação/epidemiologiaRESUMO
A presente pesquisa analisou o efeito da iluminação constante sobre a estrutura placentária de ratas, abordando parâmetros morfológicos, morfométricos e histoquímicos. Vinte ratas albinas foram submetidas aos seguintes tratamentos: 12hL/12hE por 60 dias, e acasaladas em seguida (GI); ausência de luz por 60 dias, e acasaladas em seguida (GII); iluminação constante por 60 dias, e acasaladas em seguida (GIII); iluminação constante por 60 dias, acasaladas em seguida e tratadas com melatonina (GIV). O estímulo luminoso foi em torno de 400 lux. A melatonina foi administrada na água (400mg/mL de etanol). Os resultados mostraram que histologicamente o GII apresentou vacuolização das células do trofospongio. Morfometricamente, o GIII apresentou camada do labirinto com redução no número de trofoblastos sinciciais e maior vascularização materno-fetal, hiperplasia e hipertrofia das células trofoblásticas gigantes, uma maior média da área total do disco placentário; porém, na camada de trofospongio, as células trofoblásticas e trofoblastos sinciciais não diferiram nos grupos experimentais. As placentas do GIV foram semelhantes às do GI. Histoquimicamente não houve alterações nas fibras colágenas, elásticas, reticulares e glicosaminoglicanas ácidas. Em conclusão, a iluminação constante promove alterações morfológicas e morfométricas na placenta de ratas, podendo acarretar redução funcional e restrições ao crescimento fetal. Essas alterações são abolidas pela reposição de melatonina.
This study examined the effect of constant illumination on the placental structure of rats, addressing morphological, morphometric and immunohistochemical parameters. 20 albino rats were subjected to the following treatments: GI-12hL/12hE for 60 days and then mated; GII- dark for 60 days and then mated; GIII- constant illumination for 60 days and then mated and GIV- constant light for 60 days, mated and then treated with melatonin. The light stimulus was around 400 lux. Melatonin was administered in water (400 mg / ml ethanol). The results showed that GII had histologically trofospongio vacuolization of cells. Morphometrically, GIII presented a labyrinth layer reduction in the number of syncytial trophoblasts and greater maternal-fetal vasculature, hyperplasia and hypertrophy of trophoblast giant cells, a higher average of the total area of the placenta disk, but in the trofospongio layer, the trophoblast cells and syncytial trophoblasts did not differ between experimental groups. The placentas in GIV were similar to GI. Histochemically there were no changes in the collagen and elastic fibers, reticular and acidic glycosaminoglycans. In conclusion, the constant lighting promotes morphological and morphometric changes in the placenta in rats and may lead to functional reduction and restrictions on fetal growth. These changes are abolished by the melatonin replacement.
Assuntos
Animais , Feminino , Gravidez , Ratos , Iluminação/métodos , Placenta/anatomia & histologia , Desenvolvimento Fetal , Melatonina/análise , FotoperíodoRESUMO
A presente pesquisa analisou o efeito da iluminação constante sobre a estrutura placentária de ratas, abordando parâmetros morfológicos, morfométricos e histoquímicos. Vinte ratas albinas foram submetidas aos seguintes tratamentos: 12hL/12hE por 60 dias, e acasaladas em seguida (GI); ausência de luz por 60 dias, e acasaladas em seguida (GII); iluminação constante por 60 dias, e acasaladas em seguida (GIII); iluminação constante por 60 dias, acasaladas em seguida e tratadas com melatonina (GIV). O estímulo luminoso foi em torno de 400 lux. A melatonina foi administrada na água (400mg/mL de etanol). Os resultados mostraram que histologicamente o GII apresentou vacuolização das células do trofospongio. Morfometricamente, o GIII apresentou camada do labirinto com redução no número de trofoblastos sinciciais e maior vascularização materno-fetal, hiperplasia e hipertrofia das células trofoblásticas gigantes, uma maior média da área total do disco placentário; porém, na camada de trofospongio, as células trofoblásticas e trofoblastos sinciciais não diferiram nos grupos experimentais. As placentas do GIV foram semelhantes às do GI. Histoquimicamente não houve alterações nas fibras colágenas, elásticas, reticulares e glicosaminoglicanas ácidas. Em conclusão, a iluminação constante promove alterações morfológicas e morfométricas na placenta de ratas, podendo acarretar redução funcional e restrições ao crescimento fetal. Essas alterações são abolidas pela reposição de melatonina(AU)
This study examined the effect of constant illumination on the placental structure of rats, addressing morphological, morphometric and immunohistochemical parameters. 20 albino rats were subjected to the following treatments: GI-12hL/12hE for 60 days and then mated; GII- dark for 60 days and then mated; GIII- constant illumination for 60 days and then mated and GIV- constant light for 60 days, mated and then treated with melatonin. The light stimulus was around 400 lux. Melatonin was administered in water (400 mg / ml ethanol). The results showed that GII had histologically trofospongio vacuolization of cells. Morphometrically, GIII presented a labyrinth layer reduction in the number of syncytial trophoblasts and greater maternal-fetal vasculature, hyperplasia and hypertrophy of trophoblast giant cells, a higher average of the total area of the placenta disk, but in the trofospongio layer, the trophoblast cells and syncytial trophoblasts did not differ between experimental groups. The placentas in GIV were similar to GI. Histochemically there were no changes in the collagen and elastic fibers, reticular and acidic glycosaminoglycans. In conclusion, the constant lighting promotes morphological and morphometric changes in the placenta in rats and may lead to functional reduction and restrictions on fetal growth. These changes are abolished by the melatonin replacement(AU)
Assuntos
Animais , Feminino , Gravidez , Ratos , Placenta/anatomia & histologia , Iluminação/métodos , Fotoperíodo , Melatonina/análise , Desenvolvimento FetalRESUMO
Investigou-se a influência da melatonina sobre o hemograma de ratas prenhes e dos filhotes e sobre a histogênese e morfometria do baço e do timo dos filhotes. A melatonina foi administrada na dose 0,5mg/kg de peso corporal, dissolvida em 0,1mL de etanol e diluída em 0,3mL de solução salina. Para análise do hematócrito, contagem total de hemácias e contagem total e diferencial dos leucócitos, amostras de sangue foram coletadas no sétimo, 14ºe 21ºdias de prenhez e aos 10 dias de nascimento dos filhotes. Cortes histológicos do baço e do timo da prole foram utilizados para histoquímica e morfometria. A ausência da melatonina promoveu alterações no hemograma apenas no terço final da gestação, sem interferir no hemograma dos filhotes, e induziu modificações morfológicas e morfométricas no timo e no baço nos primeiros dias de vida dos filhotes. Concluiu-se que a melatonina materna é importante para a modulação do hemograma em ratas prenhes e para o desenvolvimento normal do baço e do timo dos filhotes.
We investigated the influence of melatonin on the hemogram of pregnant rats and puppies, and on the histogenesis and morphology of the spleen and thymus of puppies. Melatonin was administered at a dose 0.5mg/kgbody weight, dissolved in 0.1mL of ethanol and diluted in 0.3mL of saline. For hematocrit analysis, total erythrocyte count and total and differential leukocyte count, blood samples were collected on the 7th, 14th and 21st days of pregnancy and the offspring at 10 days of birth. Histological sections of spleen and thymus of the offspring were used for histochemistry and morphometry. The absence of melatonin promoted changes in blood count only in the final third of gestation, without interfering with the hemogram of the puppies, and induced morphological and morphometric changes in the thymus and spleen in the first days of life of the puppies. It was concluded that maternal melatonin is important for the modulation of the blood count in pregnant rats and the normal development of the spleen and thymus of the offspring.
Assuntos
Animais , Baço/anatomia & histologia , Gravidez/fisiologia , Imunidade , Melatonina/análise , Ratos/classificaçãoRESUMO
Investigou-se a influência da melatonina sobre o hemograma de ratas prenhes e dos filhotes e sobre a histogênese e morfometria do baço e do timo dos filhotes. A melatonina foi administrada na dose 0,5mg/kg de peso corporal, dissolvida em 0,1mL de etanol e diluída em 0,3mL de solução salina. Para análise do hematócrito, contagem total de hemácias e contagem total e diferencial dos leucócitos, amostras de sangue foram coletadas no sétimo, 14ºe 21ºdias de prenhez e aos 10 dias de nascimento dos filhotes. Cortes histológicos do baço e do timo da prole foram utilizados para histoquímica e morfometria. A ausência da melatonina promoveu alterações no hemograma apenas no terço final da gestação, sem interferir no hemograma dos filhotes, e induziu modificações morfológicas e morfométricas no timo e no baço nos primeiros dias de vida dos filhotes. Concluiu-se que a melatonina materna é importante para a modulação do hemograma em ratas prenhes e para o desenvolvimento normal do baço e do timo dos filhotes.(AU)
We investigated the influence of melatonin on the hemogram of pregnant rats and puppies, and on the histogenesis and morphology of the spleen and thymus of puppies. Melatonin was administered at a dose 0.5mg/kgbody weight, dissolved in 0.1mL of ethanol and diluted in 0.3mL of saline. For hematocrit analysis, total erythrocyte count and total and differential leukocyte count, blood samples were collected on the 7th, 14th and 21st days of pregnancy and the offspring at 10 days of birth. Histological sections of spleen and thymus of the offspring were used for histochemistry and morphometry. The absence of melatonin promoted changes in blood count only in the final third of gestation, without interfering with the hemogram of the puppies, and induced morphological and morphometric changes in the thymus and spleen in the first days of life of the puppies. It was concluded that maternal melatonin is important for the modulation of the blood count in pregnant rats and the normal development of the spleen and thymus of the offspring.(AU)
Assuntos
Animais , Melatonina/análise , Gravidez/fisiologia , Baço/anatomia & histologia , Imunidade , Ratos/classificaçãoRESUMO
RESUMO A presente pesquisa teve como objetivo analisar morfologicamente os sítios de implantes endometriais sobre a região externa da musculatura da parede abdominal anterior de ratas, durante o ciclo estral. Para tanto foram utilizadas 16 ratas albinas (Rattus norvegicus albinus), da linhagem Wistar com 90 dias de idade, obtidas do biotério do Departamento de Morfologia e Fisiologia Animal da UFRPE, as quais foram submetidas à indução da endometriose. A análise histológica dos implantes foi realizada por meio da microscopia de luz, utilizando-se técnicas de colorações pela Hematoxilina-Eosina (H-E) e pelo Tricrômico de Mallory. O material coletado foi fixado em líquido de Boüin e processado para inclusão em "paraplast". Os resultados mostraram que as fases de proestro, estro e diestro foram mais favoráveis para o desenvolvimento dos implantes endometriais em ratas, quando comparadas ao metaestro.
ABSTRACT The present research was aimed to morphologically analyze the endometrial implant sites of on the external area of the musculature of the abdominal wall of female rats, during the estral cycle. Sixteen albino female rats were used (Rattusnorvegicusalbinus), of the lineage Wistar with 90 days of age, obtained from the lab. animal rearing facilities of the Department of Morphology and Animal Physiology of UFRPE, which were submitted to the induction of the endometriosis. The histologic analysis of the implants was accomplished by means of light microscopy, using Hematoxilin-Eosin (H-E) and Mallory's Trichrome staine. The collected material was fixated in Boüin's liquid and processed for inclusion in paraplasts. The results showed that the proestrus, estrus and diestrus phases were more favorable for the development of the endometrial implants in female rats, when compared to the metaestrus phase.
RESUMO
In May 2000, an operator of a (60)Co industrial gamma radiography apparatus, during a routine service, was involved in a partial-body radiological accident, which caused serious injuries to his left hand. Dose reconstruction was started aiming to assess the radiation doses, in order to assist the medical staff in the evaluation and prescription of suitable medical procedures for the patient's treatment and follow-up. This work presents the dose reconstruction used for assessment of the distribution of doses on the patient's left hand, which was made using two methods: physical and computational techniques. For the first technique a physical hand simulator was built. The computational method was performed using microcomputer software for external dose calculations, named 'Visual Monte-Carlo-VMC', together with a hand voxel simulator. The values obtained through both methods for the distribution of absorbed doses on the operator's left hand were compared. About half of them were similar within a range of uncertainty of 20%.
Assuntos
Radioisótopos de Cobalto/efeitos adversos , Mãos/efeitos da radiação , Exposição Ocupacional/efeitos adversos , Liberação Nociva de Radioativos , Radiometria/métodos , Adulto , Brasil , Humanos , Masculino , Método de Monte Carlo , Doses de RadiaçãoRESUMO
Industrial electron accelerators are used by eight installations in Brazil, with a total of 14 machines generating electron beams. These facilities are classified into categories I or II, according to the International Atomic Energy Agency (IAEA) system. In category I are included the facilities with an integrally shielded unit with interlocks, where human access during operation is not physically possible owing to the configuration of the shielding. In category II are included the facilities with a unit housed in a shielded room that is kept inaccessible during operation by an entry control system. Of the 14 accelerators operational in Brazil, 11 belong to category I and three to category II. In the present work a methodology for the assessment of the radiological safety of these accelerator facilities was developed and applied, mainly on the basis of specific recommendations from the IAEA. The main safety items were evaluated at those eight installations. According to the results obtained here, no inadequacies were observed at the three installations in category II, from the radiological safety and radioprotection points of view. Nevertheless, two out of the five installations in category I showed several deficiencies. Most of these inadequacies have been corrected during this work, and the rest are in the course of being corrected.
Assuntos
Elétrons , Indústrias , Aceleradores de Partículas , Monitoramento de Radiação/métodos , Proteção Radiológica/métodos , Gestão da Segurança/métodos , Brasil , Arquitetura de Instituições de Saúde , HumanosRESUMO
The Monte Carlo program 'Visual Monte Carlo-dose calculation' (VMC-dc) uses a voxel phantom to simulate the body organs and tissues, transports photons through this phantom and reports the absorbed dose received by each organ and tissue relevant to the calculation of effective dose as defined in ICRP Publication 60. This paper shows the validation of VMC-dc by comparison with EGSnrc and with a physical phantom containing TLDs. The validation of VMC-dc by comparison with EGSnrc was made for a collimated beam of 0.662 MeV photons irradiating a cube of water. For the validation by comparison with the physical phantom, the case considered was a whole body irradiation with a point 137Cs source placed at a distance of 1 m from the thorax of an Alderson-RANDO phantom. The validation results show good agreement for the doses obtained using VMC-dc and EGSnrc calculations, and from VMC-dc and TLD measurements. The program VMC-dc was then applied to the calculation of doses due to immersion in water containing gamma emitters. The dose conversion coefficients for water immersion are compared with their equivalents in the literature.