Key topics for making decisions on decorporation terapies.

Decorporation therapies increase the excretion of the incorporated material and therefore may reduce the probability of the occurrence of stochastic effects and may avoid deterministic effects in persons internally contaminated with radionuclides. The decision to initiate decorporation therapy should consider the effects of treatment in relation to the benefit provided. The literature presents threshold values above which treatment is recommended. The objective of this work is to collect and summarize recommendations on decorporation therapy. Ten key topics are presented for consideration by a multidisciplinary team when assessing the risk-benefit balance for performing decorporation therapy.

Analysis of recommended thresholds for medical evaluation in cases of radionuclide intakes.

Literature presents different thresholds for evaluation intended for screening people who may need additional medical assistance in cases of radionuclide intakes. There are thresholds based on the committed effective dose (CED), as well as thresholds based on the relative biological effectiveness-weighted absorbed dose (ADT) in the bone marrow and lungs. As in some emergency exposure scenarios with radionuclide intakes the risk for stochastic effects may be low whereas the threshold for deterministic effects may be exceeded, the aim of this analysis was to evaluate and to present the most appropriated threshold for each exposure scenario of interest. The results show that even adopting CED of 100 mSv as threshold for medical evaluation, it is important to screen for tissue reactions because in some scenarios the adopted threshold for deterministic effects is reached whilst the CED is below the adopted threshold value for stochastic effects.

Sensory remapping: a possible therapy option / Remapeamento sensorial: uma possível opção de terapia

The human sensory receptors are morphologically specialized to transduce specific stimuli into the brain. However, when an injury occurs, mainly in the spinal cord, which can be of traumatic or non-traumatic origin, it provokes various degrees of sensory deficits, autonomic, motor and sphincter dysfunction below the level of the injury. Based on this, a new therapeutic modality is being proposed by neuroscientist Miguel Nicolelis, which is based on the brain-machine interface, that is, using other pathways so that the information can reach the cerebral cortex and thus be consciously processed (AU).

Os receptores sensoriais humanos são morfologicamente especializados para realizar a transdução de estímulos específicos para o encéfalo. Entretanto, quando ocorre uma lesão, principalmente, na medula espinal, que pode ser de origem traumática e não traumática, provocam diversos graus de déficits sensoriais, disfunção autônoma, motora e esfincteriana, abaixo do nível da lesão. Com base nisso, uma nova modalidade terapêutica está sendo proposto pelo neurocientista Miguel Nicolelis, que tem como base a interface cérebro máquina, isto é, utilizar-se de outras vias para que as informações possam chegar no córtex cerebral e assim serem processadas conscientemente.Palavras-chave: Interfaces cérebro-computador, Neurociências, Órgãos dos sentidos (AU).

Iniciação cientifica em Saúde Coletiva: desafios e percalços discentes / Scientific initiation in Collective Health: students challenges and mishaps

O presente artigo tem como objetivo relatar experiências de iniciações científicas que envolveram a tríade ensino-serviço-comunidade no ambiente da Atenção Primária a Saúde na formação acadêmica baseada na aprendizagem significativa de uma discente do curso de Fisioterapia. O relato se organiza na discussão da elaboração do pré-projeto; protocolos da Plataforma Brasil e Comitê de Ética em Pesquisas com Seres Humanos (CEP) ­ algumas das burocracias encontradas na pesquisa científica, aprovação pelo CEP e pelo edital da instituição sendo finalizada com os contextos vividos durante duas iniciações científicas que tiveram o mesmo objetivo geral a ser pesquisado, avaliar o uso de plantas medicinas por idosos com Diabetes Melittus tipo 2 em comunidades diferentes em Teresina-PI e que tiveram dados coletados na sala de espera das reuniões do programa HIPERDIA ou, quando não for possível, no domicílio dos participantes selecionados. As reflexões baseadas nas vivências junto às equipes multiprofissionais da Estratégia de Saúde da Família, da comunidade idosa e manejo das entrevistas nas iniciações científicas, que se deram em circunstâncias distintas e abrangentes, são consideradas como uma forma de aprendizagem significativa que modela o futuro profissional da área da saúde a uma abordagem mais humana ao usuário e que valoriza a pesquisa científica como ferramenta na tomada de decisões nos planejamentos das condutas na Atenção Primária.

This article aims to report experiences of scientific initiations that involved the teaching ­ service - community triad in the Primary Health Care environment in the academic training based on the meaningful learning of a student of the Physiotherapy course. The report is organized in the discussion of the preparation of the preproject; protocols of the Brazil Platiform and Ethics Committee in Research with Human Beings some of the bureaucracies found in scientific research, approval by the research ethics committee and the edict of the institution being finalized with the contexts lived during two scientific initiations that had the same general objective to evaluate the use of medicinal plants by elderly people with Diabetes Melittus type 2 in different communities in Teresina - PI and who had data collected in the waiting room of HIPERDIA meetings or, when this is not possible, at the domicile of the selected participants. The reflections based on the experiences with the multiprofessional teams of the Family Health Strategy, the elderly community and the management of interviews in scientific initiations, which took place under different and comprehensive circumstances, are considered as a form of meaningful learning that shapes the professional future of the health care to a more humane approach to the user and that values scientific research as a tool in decision making in Primary Care behaviors.

GHSI EMERGENCY RADIONUCLIDE BIOASSAY LABORATORY NETWORK - SUMMARY OF THE SECOND EXERCISE.

The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency as a means of enhancing response capability, health outcomes and community resilience. GHSI partners conducted an exercise in collaboration with the WHO Radiation Emergency Medical Preparedness and Assistance Network and the IAEA Response and Assistance Network, to test the participating laboratories (18) for their capabilities in in vitro assay of biological samples, using a urine sample spiked with multiple high-risk radionuclides (90Sr, 106Ru, 137Cs, and 239Pu). Laboratories were required to submit their reports within 72 h following receipt of the sample, using a pre-formatted template, on the procedures, methods and techniques used to identify and quantify the radionuclides in the sample, as well as the bioassay results with a 95% confidence interval. All of the participating laboratories identified and measured all or some of the radionuclides in the sample. However, gaps were identified in both the procedures used to assay multiple radionuclides in one sample, as well as in the methods or techniques used to assay specific radionuclides in urine. Two-third of the participating laboratories had difficulties in determining all the radionuclides in the sample. Results from this exercise indicate that challenges remain with respect to ensuring that results are delivered in a timely, consistent and reliable manner to support medical interventions. Laboratories within the networks are encouraged to work together to develop and maintain collective capabilities and capacity for emergency bioassay, which is an important component of radiation emergency response.

Internal dosimetry of nuclear medicine workers through the analysis of (131)I in aerosols.

(131)I is widely used in nuclear medicine for diagnostic and therapy of thyroid diseases. Depending of workplace safety conditions, routine handling of this radionuclide may result in a significant risk of exposure of the workers subject to chronic intake by inhalation of aerosols. A previous study including in vivo and in vitro measurements performed recently among nuclear medicine personnel in Brazil showed the occurrence of (131)I incorporation by workers involved in the handling of solutions used for radioiodine therapy. The present work describes the development, optimization and application of a methodology to collect and analyze aerosol samples aiming to assess internal doses based on the activity of (131)I present in a radiopharmacy laboratory. Portable samplers were positioned at one meter distant from the place where non-sealed liquid sources of (131)I are handled. Samples were collected over 1h using high-efficiency filters containing activated carbon and analyzed by gamma spectrometry with a high-purity germanium detection system. Results have shown that, although a fume hood is available in the laboratory, (131)I in the form of vapor was detected in the workplace. The average activity concentration was found to be of 7.4Bq/m(3). This value is about three orders of magnitude below the Derived Air Concentration (DAC) of 8.4kBq/m(3). Assuming that the worker is exposed by inhalation of iodine vapor during 1h, (131)I concentration detected corresponds to an intake of 3.6Bq which results in a committed effective dose of 7.13×10(-5)mSv. These results show that the radiopharmacy laboratory evaluated is safe in terms of internal exposure of the workers. However it is recommended that the presence of (131)I should be periodically re-assessed since it may increase individual effective doses. It should also be pointed out that the results obtained so far reflect a survey carried out in a specific workplace. Thus, it is suggested to apply the methodology developed in this work to other nuclear medicine services where significant activities of (131)I are routinely handled as an effective means to optimize individual exposures and improve occupational radiation protection safety.

Development and validation of a technique for the determination of 226Ra and 228Ra by liquid scintillation in liquid samples.

Radium isotopes are dispersed in the environment according to their physicochemical characteristics. Considering their long half-lives and radiological effects, (226)Ra and (228)Ra are very important issues in radiological protection. In Brazil, radium isotopes represent an exposure problem both in nuclear fuel cycle installations and in high natural radiation background areas. The experimental part of this work includes the development of a technique for the determination of (226)Ra and (228)Ra by liquid scintillation with potential application in biological samples. Radium was concentrated and then separated from other constituents of the sample by co-precipitation/precipitation with Ba(Ra)SO(4). The precipitate was filtered and weighted to calculate the chemical yield. The filter containing the precipitate of Ba(Ra)SO(4) was transferred to a scintillation vial. Two methods were used to prepare the sources. The first one consisted of the addition of water (8 ml), Instagel XF (8 ml) and UltimaGold (4 ml) in the vial containing the filter and the precipitate, forming a gel suspension. In the second method, the precipitate was dissolved with 0.2 M ethylene-diamine-tetra-acetic-acid solution (9 ml) and 11 ml of scintillation solution (Optiphase Hisafe 3) was added to the vial, forming an aqueous and an organic phase. The solutions obtained were counted in a low background scintillation spectrometry system (Quantulus) suitable for the detection and identification of both alpha and beta particles for the determination of (226)Ra and (228)Ra. The activity values of (226)Ra and (228)Ra calculated by the two methods are in good agreement with the reference values, indicating that both methods are suitable for the determination of (226)Ra and (228)Ra.

Uncertainty on faecal analysis on dose assessment.

Monitoring programmes for internal dose assessment may need to have a combination of bioassay techniques, e.g. urine and faecal analysis, especially in workplaces where compounds of different solubilities are handled and also in cases of accidental intakes. Faecal analysis may be an important data for assessment of committed effective dose due to exposure to insoluble compounds, since the activity excreted by urine may not be detectable, unless a very sensitive measurement system is available. This paper discusses the variability of the daily faecal excretion based on data from just one daily collection; collection during three consecutive days: samples analysed individually and samples analysed as a pool. The results suggest that just 1 d collection is not appropriate for dose assessment, since the 24 h uranium excretion may vary by a factor of 40. On the basis of this analysis, the recommendation should be faecal collection during three consecutive days, and samples analysed as a pool, it is more economic and faster.

Exposure of workers in a mineral processing industry in Brazil.

In Brazil there are many regions where the extraction mining and processing of ores containing elements of great economical importance as tin, niobium and tantalum. Some of these ores have uranium and thorium natural decay series associated. This study was carried out in a niobium mine, where is obtained concentrates of niobates-tantalates, cassiterite and zirconite. The aim of this study is the evaluation of the occupational exposure to uranium, thorium, niobium and tin through urine bioassay data. In order to have it, 105 urine samples were analysed: 17 samples of exposed workers collected after a working day, 49 samples of exposed workers collected before a working day and 39 samples of local non-exposed people, assigned as a control group. The samples were analysed by mass spectrometry. The obtained results showed that the average concentration of Nb, Sn and U in the exposed group is statistically higher than those found in the control group indicating an occupational exposure. For Th there were no statistically difference between the exposed and the control group.

Mercury and organic carbon distribution in six lakes from the North of Rio de Janeiro State

Devido a sua toxicidade e capacidade de se acumular em organismos, o mercúrio é considerado um poluente extremamente perigoso. Suas propriedades associadas às condições ambientais podem resultar em uma larga dispersão. Nas ultimas décadas diversos trabalhos tem demonstrado a contaminação da região Norte do Estado do Rio de Janeiro por Hg, inclusive com casos de contaminação humana. Desta forma, o objetivo do presente estudo é avaliar a distribuição de Hg em sedimentos de seis lagoas da região norte do Estado do Rio de Janeiro, relacionando as concentrações de Hg com fatores que podem influenciar sua mobilidade nos sedimentos como o carbono orgânico. As amostras de sedimento superficial foram coletadas ao longo de seis das principais lagoas da região e os perfis foram retirados de pontos centrais das mesmas. Os elevados valores de Hg observados nos sedimentos superficiais de lagoas como a do Campelo (349,6 µg.kg -1), parecem reforçar a hipótese de entradas recentes deste elemento para o sistema. Os resultados sugerem ainda que o Hg que foi utilizado no passado proveniente principalmente da aplicação de fungicidas organo-mercuriais e do garimpo de ouro na região, ainda pode estar sendo transportado para sistemas adjacentes. As correlações Hg/carbono orgânico se mostraram significativamente positivas com p< 0,05, indicando que para a região, a matéria orgânica parece possuir papel significativo na retenção do Hg.