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1.
QJM ; 114(12): 865-871, 2022 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-34850210

RESUMO

BACKGROUND: The definition of 'long-COVID syndrome' (LCS) is still debated and describes the persistence of symptoms after viral clearance in hospitalized or non-hospitalized patients affected by coronavirus disease 2019 (COVID-19). AIM: In this study, we examined the prevalence and the risk factors of LCS in a cohort of patients with previous COVID-19 and followed for at least 6 months of follow-up. DESIGN: We conducted a prospective study including all hospitalized patients affected by COVID-19 at our center of Infectious Diseases (Vercelli, Italy) admitted between 10 March 2020 and 15 January 2021 for at least 6 months after discharge. Two follow-up visits were performed: after 1 and 6 months after hospital discharge. Clinical, laboratory and radiological data were recorded at each visit. RESULTS: A total of 449 patients were included in the analysis. The LCS was diagnosed in 322 subjects at Visit 1 (71.7%) and in 206 at Visit 2 (45.9); according to the post-COVID-19 functional status scale we observed 147 patients with values 2-3 and 175 with values >3 at Visit 1; at Visit 2, 133 subjects had the score between 2-3 and 73 > 3. In multivariate analysis, intensive care unit (ICU) admission (OR = 2.551; 95% CI = 1.998-6.819; P = 0.019), time of hospitalization (OR = 2.255; 95% CI = 1.018-6.992; P = 0.016) and treatment with remdesivir (OR = 0.641; 95% CI = 0.413-0.782; P < 0.001) were independent predictors of LCS. CONCLUSIONS: Treatment with remdesivir leads to a 35.9% reduction in LCS rate in follow-up. Severity of illness, need of ICU admission and length of hospital stay were factor associated with the persistence of PCS at 6 months of follow-up.


Assuntos
Monofosfato de Adenosina/uso terapêutico , Alanina/uso terapêutico , Tratamento Farmacológico da COVID-19 , COVID-19 , Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , COVID-19/complicações , Hospitalização , Humanos , Incidência , Unidades de Terapia Intensiva , Estudos Prospectivos , Fatores de Risco , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda
2.
J Endocrinol Invest ; 45(1): 29-41, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34128215

RESUMO

PURPOSE: First-generation somatostatin analogs, octreotide (OCT) and lanreotide, are the cornerstone for the medical treatment of growth hormone (GH)-secreting pituitary tumors. A new multireceptor analog, such as pasireotide (PAS), showed better activity than OCT in long-term treatment of patients with acromegaly, but modulation of intracellular key processes is still unclear in vitro. In this study, we evaluated the antitumor activity of OCT and PAS in two GH-secreting pituitary tumor cell lines, GH3 and GH4C1, after a long-term incubation. METHODS: The effects of PAS and OCT on the cell viability, cell cycle, apoptosis, GH secretion, and tumor-induced angiogenesis have been evaluated through a colorimetric method (MTS Assay), DNA flow cytometry with propidium iodide, and Annexin V-FITC/propidium iodide staining, ELISA assay and zebrafish platform, respectively. RESULTS: PAS showed a more potent antitumor activity compared to OCT in GH3 cell line exerted through inhibition of cell viability, perturbation of cell cycle progression, and induction of apoptosis after 6 days of incubation. A concomitant decrease in GH secretion has been observed after 2 days of incubation only with PAS. No effect on tumor-induced angiogenesis has been reported after treatment with OCT or PAS in zebrafish/tumor xenograft model. CONCLUSION: Long-term incubation with PAS showed a more potent antitumor activity than that reported after OCT in GH3 cells, mainly modulated by a cell cycle perturbation and a relevant induction in apoptosis.


Assuntos
Adenoma/patologia , Adenoma Hipofisário Secretor de Hormônio do Crescimento/patologia , Octreotida/farmacologia , Somatostatina/análogos & derivados , Animais , Animais Geneticamente Modificados , Apoptose/efeitos dos fármacos , Embrião não Mamífero , Peptídeos Cíclicos , Ratos , Somatostatina/farmacologia , Somatotrofos/efeitos dos fármacos , Somatotrofos/metabolismo , Somatotrofos/patologia , Fatores de Tempo , Células Tumorais Cultivadas , Peixe-Zebra/embriologia
3.
Ann ICRP ; 49(1_suppl): 143-153, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32777956

RESUMO

Whereas scientific evidence is the basis for recommendations and guidance on radiological protection, professional ethics is critically important and should always guide professional behaviour. The International Commission on Radiological Protection (ICRP) established Task Group 109 to advise medical professionals, patients, families, carers, the public, and authorities about the ethical aspects of radiological protection of patients in the diagnostic and therapeutic use of radiation in medicine. Occupational exposures and research-related exposures are not within the scope of this task group. Task Group 109 will produce a report that will be available to the different interested parties for consultation before publication. Presently, the report is at the stage of a working document that has benefitted from an international workshop organised on the topic by the World Health Organization. It presents the history of ethics in medicine in ICRP, and explains why this subject is important, and the benefits it can bring to the standard biomedical ethics. As risk is an essential part in decision-making and communication, a summary is included on what is known about the dose-effect relationship, with emphasis on the associated uncertainties. Once this theoretical framework has been presented, the report becomes resolutely more practical. First, it proposes an evaluation method to analyse specific situations from an ethical point of view. This method allows stakeholders to review a set of six ethical values and provides hints on how they could be balanced. Next, various situations (e.g. pregnancy, elderly, paediatric, end of life) are considered in two steps: first within a realistic, ethically challenging scenario on which the evaluation method is applied; and second within a more general context. Scenarios are presented and discussed with attention to specific patient circumstances, and on how and which reflections on ethical values can be of help in the decision-making process. Finally, two important related aspects are considered: how should we communicate with patients, family, and other stakeholders; and how should we incorporate ethics into the education and training of medical professionals?


Assuntos
Guias como Assunto , Medicina Nuclear/ética , Exposição à Radiação/prevenção & controle , Proteção Radiológica/normas , Humanos , Agências Internacionais
4.
Ann ICRP ; 47(1): 1-65, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29457463

RESUMO

Abstract ­: Despite a longstanding recognition that radiological protection is not only a matter of science, but also ethics, ICRP publications have rarely addressed the ethical foundations of the system of radiological protection explicitly. The purpose of this publication is to describe how the Commission has relied on ethical values, either intentionally or indirectly, in developing the system of radiological protection with the objective of presenting a coherent view of how ethics is part of this system. In so doing, it helps to clarify the inherent value judgements made in achieving the aim of the radiological protection system as underlined by the Commission in Publication 103. Although primarily addressed to the radiological protection community, this publication is also intended to address authorities, operators, workers, medical professionals, patients, the public, and its representatives (e.g. NGOs) acting in the interest of the protection of people and the environment. This publication provides the key steps concerning the scientific, ethical, and practical evolutions of the system of radiological protection since the first ICRP publication in 1928. It then describes the four core ethical values underpinning the present system: beneficence/ non-maleficence, prudence, justice, and dignity. It also discusses how these core ethical values relate to the principles of radiological protection, namely justification, optimisation, and limitation. The publication finally addresses key procedural values that are required for the practical implementation of the system, focusing on accountability, transparency, and inclusiveness. The Commission sees this publication as a founding document to be elaborated further in different situations and circumstances.


Assuntos
Monitoramento de Radiação/ética , Proteção Radiológica/normas , Humanos
5.
J Endocrinol Invest ; 40(7): 761-770, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28247216

RESUMO

PURPOSE: Type I interferons (IFN-α and IFN-ß) are a class of cytokines that exert several biological activities, such as modulation of cell proliferation and differentiation and of the immune system. Although these cytokines interact with a common receptor complex, IFN-ß showed a more potent antitumor activity than IFN-α in several tumor models. New recombinant human IFN-ß products, such as IFN-ß1a and IFN-ß1b, have been produced in order to improve the stability and bioavailability of natural IFN-ß. In this report, we analyzed the effects of recombinant IFN-ß1a on the cell proliferation of two human androgen-resistant prostate cancer cell lines with neuroendocrine differentiation (DU-145, PC-3) and related mechanisms of action. METHODS: The effects of IFN-ß1a on the cell growth proliferation, cell cycle, and apoptosis have been evaluated in DU-145 and PC-3 cells through MTT assay, DNA flow cytometry with propidium iodide, and Annexin V-FITC/propidium iodide staining, respectively. Moreover, the expression of neuron-specific enolase (NSE), cleaved caspase-3, caspase-8, and PARP was evaluated through Western blotting. RESULTS: IFN-ß1a showed a significant anti-proliferative activity in both androgen-resistant cell lines. This effect was related to cell cycle perturbation and induction in apoptosis, as shown by flow cytometric analysis, the activation of caspase-3 and caspase-8 and PARP cleavage during incubation with IFN-ß1a. Moreover, this cytokine reduced the expression of NSE in both cell lines. CONCLUSIONS: Recombinant IFN-ß1a (Rebif) showed a potent in vitro anti-proliferative activity in androgen-resistant prostate cancer cells, and it could represent a promising tool for the treatment of this tumor.


Assuntos
Antineoplásicos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Interferon beta-1a/farmacologia , Tumores Neuroendócrinos/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Masculino , Tumores Neuroendócrinos/patologia , Neoplasias de Próstata Resistentes à Castração/patologia , Células Tumorais Cultivadas
6.
Health Phys ; 111(4): 317-26, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27575344

RESUMO

This paper presents a review of risk analyses in radiotherapy (RT) processes carried out by using Healthcare Failure Mode Effect Analysis (HFMEA) methodology, a qualitative method that proactively identifies risks to patients and corrects medical errors before they occur. This literature review was performed to provide an overview of how to approach the development of HFMEA applications in modern RT procedures, comparing recently published research conducted to support proactive programs to identify risks. On the basis of the reviewed literature, the paper suggests HFMEA shortcomings that need to be addressed.


Assuntos
Análise do Modo e do Efeito de Falhas na Assistência à Saúde/métodos , Erros Médicos/mortalidade , Neoplasias/mortalidade , Neoplasias/radioterapia , Lesões por Radiação/mortalidade , Radioterapia/mortalidade , Análise do Modo e do Efeito de Falhas na Assistência à Saúde/estatística & dados numéricos , Humanos , Erros Médicos/estatística & dados numéricos , Radioterapia/estatística & dados numéricos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Taxa de Sobrevida
7.
Ann ICRP ; 44(1 Suppl): 138-43, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25816267

RESUMO

In April 2011, the International Commission on Radiological Protection issued a statement on reduction of the equivalent dose limits for the lens of the eye, and strongly recommended its consideration in the revision of the International Atomic Energy Agency's International Basic Safety Standards on Radiation Protection. The reduced dose limit was incorporated in the final version of the Basic Safety Standards. As significant concern was expressed by radiation protection professionals worldwide, the International Radiation Protection Association (IRPA) established a task group to assess the impact of implementation of the revised dose limit for the lens of the eye for occupational exposure. IRPA Associate Societies (ASs) were asked for their views using a questionnaire addressing three topics: implications for dosimetry, implications for methods of protection, and wider implications. The responses received indicate various methods of approach and express different points of view, reflecting nuances of particular ASs or specific professional groups. Topic experts nominated by ASs were selected to assist with collation of responses, and a report was produced by the task group. Conclusions were drawn on the three issues, including potential cost implications. A number of recommendations were drawn from the responses received including: the request for more understanding about the relationship between exposure of the lens of the eye and cataract formation, and further guidance to assist implementation; the importance of economic and social considerations when introducing the limits into national regulations; the need to propose or define procedures related to employment of people with existing or pre-cataract conditions; and the practical aspects relating to dosimetry and protective equipment.


Assuntos
Cristalino/efeitos da radiação , Doses de Radiação , Proteção Radiológica/normas , Humanos , Radiometria
8.
Radiat Prot Dosimetry ; 164(1-2): 154-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25389361

RESUMO

Using an analysis of the way European newspapers covered the Fukushima nuclear accident, this article explores how the mass media transmit information about radiation risks from experts to the general public. The study applied a media content analysis method on a total of 1340 articles from 12 leading newspapers in 6 countries: Belgium (N = 260), Italy (N = 270), Norway (N = 133), Russia (N = 172), Slovenia (N = 190) and Spain (N = 315). All articles analysed were selected as being directly or indirectly related to the Fukushima accident by containing the word 'nuclear' and/or 'Fukushima' and were published between the 11th March and the 11th May 2011. The data presented here focus specifically on a cross-cultural comparison of the way the media use quantitative units. Results suggest that although experts are accustomed to communicating about radiological risks in technical language, often using quantitative units to describe the risks, mass media do not tend to use these units in their reporting. Although the study found a large variation in the measurement units used in different countries, it appeared that journalists in all the analysed countries preferred to describe radioactivity by comparing different radiation exposures, rather than reporting the actual measured units. The paper concludes with some practical guidelines for sound public communication about radiation risks.


Assuntos
Acidente Nuclear de Fukushima , Disseminação de Informação/métodos , Meios de Comunicação de Massa/estatística & dados numéricos , Exposição à Radiação/estatística & dados numéricos , Monitoramento de Radiação/estatística & dados numéricos , Cinza Radioativa/estatística & dados numéricos , Europa (Continente) , Medição de Risco/estatística & dados numéricos , Federação Russa
9.
Radiat Prot Dosimetry ; 164(1-2): 70-4, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25344889

RESUMO

In 2012, International Radiation Protection Association (IRPA) established a Task Group to provide an assessment of the impact of the implementation of the ICRP-revised dose limit for the lens of the eye for occupational exposure. Associated Societies (ASs) of IRPA were asked to provide views and comments on the basis of a questionnaire addressing three principal topics: (i) implications for dosimetry, (ii) implications for methods of protection and (iii) wider implications of implementing the revised limits. A summary of the collated responses regarding dosimetry is presented and discussed. There is large agreement on the most critical aspects and difficulties in setting up an appropriate monitoring programme for the lens of the eyes. The recent international standards and technical documents provide guidance for some of the concerns but other challenges remain in terms of awareness, acceptance and practicalities.


Assuntos
Cristalino/efeitos da radiação , Exposição Ocupacional/análise , Doses de Radiação , Lesões por Radiação/prevenção & controle , Proteção Radiológica/normas , Radiometria/normas , Absorção de Radiação , Relação Dose-Resposta à Radiação , Guias como Assunto , Humanos , Internacionalidade , Cristalino/lesões , Concentração Máxima Permitida , Lesões por Radiação/etiologia
10.
IEEE Trans Neural Syst Rehabil Eng ; 21(3): 391-403, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23559064

RESUMO

Major depression is one of the leading causes of disabling condition worldwide and its treatment is often challenging and unsatisfactory, since many patients become refractory to pharmacological therapies. Transcranial magnetic stimulation (TMS) is a noninvasive neurophysiological investigation mainly used to study the integrity of the primary motor cortex excitability and of the cortico-spinal tract. The development of paired-pulse and repetitive TMS (rTMS) paradigms has allowed investigators to explore the pathophysiology of depressive disorders and other neuropsychiatric diseases linked to brain excitability dysfunctions. Repetitive transcranial magnetic stimulation has also therapeutic and rehabilitative capabilities since it is able to induce changes in the excitability of inhibitory and excitatory neuronal networks that may persist in time. However, the therapeutic effects of rTMS on major depression have been demonstrated by analyzing only the improvement of neuropsychological performance. The aim of this study was to investigate cortical excitability changes on 12 chronically-medicated depressed patients (test group) after rTMS treatment and to correlate neurophysiological findings to neuropsychological outcomes. In detail, we assessed different parameters of cortical excitability before and after active rTMS in the test group, then compared to those of 10 age-matched depressed patients (control group) who underwent sham rTMS. In line with previous studies, at baseline both groups exhibited a significant interhemispheric difference of motor cortex excitability. This neurophysiological imbalance was then reduced in the patients treated with active rTMS, resulting also in a clinical benefit as demonstrated by the improvement in neuropsychological test scores. On the contrary, after sham rTMS, the interhemispheric difference was still evident in the control group. The reported clinical benefits in the test group might be related to the plastic remodeling of synaptic connection induced by rTMS treatment.


Assuntos
Transtorno Depressivo Maior/fisiopatologia , Córtex Motor/fisiopatologia , Córtex Motor/efeitos da radiação , Estimulação Magnética Transcraniana/métodos , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/prevenção & controle , Resistência a Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
11.
J Radiol Prot ; 33(4): 855-68, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24446535

RESUMO

This report was commissioned by the IRPA President to provide an assessment of the impact on members of IRPA Associate Societies of the introduction of ICRP recommendations for a reduced dose limit for the lens of the eye. The report summarises current practice and considers possible changes that may be required. Recommendations for further collaboration, clarification and changes to working practices are suggested.


Assuntos
Cristalino/lesões , Cristalino/efeitos da radiação , Guias de Prática Clínica como Assunto , Lesões por Radiação/etiologia , Lesões por Radiação/prevenção & controle , Proteção Radiológica/normas , Relação Dose-Resposta à Radiação , Humanos , Internacionalidade , Doses de Radiação
12.
Radiat Prot Dosimetry ; 139(1-3): 250-3, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20228050

RESUMO

Owing to the introduction of new diagnostic procedures, such as computed tomography (CT), positron emission tomography (PET) and single photon emission computed tomography (SPECT), the individual dose caused by medical exposures has grown rapidly in the last years. This is especially a subject to radiation protection for nuclear medical diagnosis, since in this case radiopharmaceuticals are administered to the patient, meaning not only a radiation exposure to the diseased tissue but also to the healthy tissues of large parts of the body. 'Minimizing Activity and Dose with Enhanced Image quality by Radiopharmaceutical Administrations' (MADEIRA) is a project cofunded by the European Commission within the Seventh Euratom Framework Programme that aims to improve three-dimensional (3D) nuclear medical imaging technologies significantly. MADEIRA is aiming to improve the efficacy and safety of 3D PET and SPECT functional imaging by optimising the spatial resolution and the signal-to-noise ratio, improving the knowledge of the temporal variation of the radiopharmaceuticals' uptake in and clearance from tumourous and healthy tissues, and evaluation of the corresponding patient dose. Using an optimised imaging procedure that improves the information gained per unit administered dose, MADEIRA aims especially to reduce the dose to healthy tissues of the patient. In this paper, an overall summary of the current achievements will be presented.


Assuntos
Carga Corporal (Radioterapia) , Aumento da Imagem/métodos , Doses de Radiação , Radiometria/métodos , Compostos Radiofarmacêuticos/análise , Tomografia Computadorizada de Emissão/métodos , Algoritmos , Simulação por Computador , Relação Dose-Resposta à Radiação , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Modelos Biológicos , Proteção Radiológica/métodos , Compostos Radiofarmacêuticos/administração & dosagem , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Gerontology ; 56(3): 298-302, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20051663

RESUMO

BACKGROUND: Vascular damage of frontal-subcortical circuits involved in mood regulation and cognition might be the main contributor to the pathogenesis of late-life depression, and it is linked to poor response to treatment. OBJECTIVE: To investigate the relationship between executive dysfunction and outcome of depressive symptoms among elderly patients with subcortical ischemic vascular disease. METHODS: Ninety-two elderly patients with white matter lesions (WMLs) or lacunar infarcts (LAs) on brain MRI and depressive symptomatology were consecutively recruited. Depression was rated with the Hamilton Depression Rating Scale (HDRS). Evaluation of executive functions by means of the Stroop color-word test was performed at entry of the study, and WMLs were categorized into mild, moderate or severe. Mood was reevaluated by means of HDRS after the 12th week of pharmacological treatment. RESULTS: Psychomotor retardation, difficulties at work, apathy, and lack of insight were the predominant symptoms. Fifty-six patients (62.8%) had a neuroradiological picture of WMLs, while the remaining 33 (37.1%) had LAs. Executive dysfunctions significantly and independently predict poor outcome of depressive symptoms. Patients with the severest WMLs showed not only a greater executive dysfunction, but also a minor response to antidepressant treatment. CONCLUSION: This study supports the vascular depression hypothesis. WMLs are of crucial clinical relevance as they are linked with cognitive symptoms and poor antidepressant outcome.


Assuntos
Isquemia Encefálica/psicologia , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/patologia , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/etiologia , Atividades Cotidianas , Idoso , Antidepressivos de Segunda Geração/uso terapêutico , Isquemia Encefálica/patologia , Isquemia Encefálica/terapia , Citalopram/uso terapêutico , Transtornos Cognitivos/terapia , Estudos de Coortes , Transtorno Depressivo/patologia , Escolaridade , Feminino , Humanos , Masculino , Teste de Stroop , Resultado do Tratamento
14.
Appl Radiat Isot ; 67(1): 152-4, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18805015

RESUMO

Complex situations related to the environment, as in the regions affected by the Chernobyl accident and regions in which nuclear weapons testing were undertaken, as in Semipalatinsk, could be reflected in the trace element content in mothers' milk. The evaluation of fractional transfer to milk of ingested or inhaled activity and of the corresponding dose coefficients for the infant, following a mothers' radioactive intake, can take advantage from wide-ranging studies of elemental and radionuclide contents in mothers' milk. In this work the possibility to determine elements, such as Ru, Zr, Nb, Te, Ce, Th, U, in milk powder has been investigated. Although results from elemental analyses of breast milk are to be found in the literature, the determination of the identified elements has attracted poor attention since they are not considered essential elements from a biological point of view. Nevertheless, in the case of radioactive releases to the environment, such data could be of interest in evaluation of dose to the breast-fed infant.


Assuntos
Monitoramento Ambiental , Leite Humano/química , Radioisótopos/análise , Aleitamento Materno , Feminino , Humanos , Recém-Nascido , Mães , Nêutrons , Doses de Radiação , Oligoelementos/análise
15.
Radiat Prot Dosimetry ; 127(1-4): 266-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17942442

RESUMO

Biokinetic models are used in radiation protection to assess internal radiation doses. Experiments with stable isotopes as tracers can be performed to obtain characteristic parameters of these models. Two methods for the measurement of zirconium isotopes in human biological samples are presented--thermal ionisation mass spectrometry (TIMS) and proton nuclear activation analysis (PNA). Descriptions include sample preparation, operating conditions, relative uncertainties and method detection limits as well as important properties of both methods.


Assuntos
Bioensaio/métodos , Modelos Biológicos , Contagem Corporal Total/métodos , Zircônio/análise , Zircônio/farmacocinética , Simulação por Computador , Isótopos/análise , Isótopos/farmacocinética , Cinética , Doses de Radiação , Eficiência Biológica Relativa , Sensibilidade e Especificidade , Distribuição Tecidual
16.
Radiat Prot Dosimetry ; 127(1-4): 311-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17686965

RESUMO

The EUropean RAdiation DOSimetry Group (EURADOS) initiated in 2005 the CONRAD Project, a Coordinated Network for Radiation Dosimetry funded by the European Commission (EC), within the 6th Framework Programme (FP). The main purpose of CONRAD is to generate a European Network in the field of Radiation Dosimetry and to promote both research activities and dissemination of knowledge. The objective of CONRAD Work Package 5 (WP5) is the coordination of research on assessment and evaluation of internal exposures. Nineteen institutes from 14 countries participate in this action. Some of the activities to be developed are continuations of former European projects supported by the EC in the 5th FP (OMINEX and IDEAS). Other tasks are linked with ICRP activities, and there are new actions never considered before. A collaboration is established with CONRAD Work Package 4, dealing with Computational Dosimetry, to organise an intercomparison on Monte Carlo modelling for in vivo measurements of (241)Am deposited in a knee phantom. Preliminary results associated with CONRAD WP5 tasks are presented here.


Assuntos
Academias e Institutos/organização & administração , Bioensaio/métodos , União Europeia/organização & administração , Radiometria/tendências , Pesquisa/organização & administração , Carga Corporal (Radioterapia) , Humanos
17.
Radiat Prot Dosimetry ; 127(1-4): 93-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17556343

RESUMO

The objective of this Task Group is the coordination of research studies on biokinetic models and the evaluation of the implications of new biokinetic models on dose assessment and safety standards. For this the new ICRP models, which will be used for a revision of ICRP Publications 30, 54, 68 and 78, are implemented into six different computer codes in five European countries and quality assured by intercomparison procedures. The work has started with the implementation of the new ICRP Alimentary Tract Model. New systemic models and the new NCRP wound model will follow. The work also includes the evaluation of experimental results in terms of formulation by the new model structures and a quality assurance of model formulation.


Assuntos
Corpos Estranhos/fisiopatologia , Modelos Biológicos , Lesões por Radiação/fisiopatologia , Radioisótopos/farmacocinética , Radioisótopos/toxicidade , Radiometria/métodos , Ferimentos Penetrantes/fisiopatologia , Carga Corporal (Radioterapia) , Simulação por Computador , Corpos Estranhos/complicações , Humanos , Cinética , Taxa de Depuração Metabólica , Lesões por Radiação/etiologia , Eficiência Biológica Relativa , Ferimentos Penetrantes/etiologia
18.
J Environ Radioact ; 91(1-2): 15-26, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16997435

RESUMO

Different types of materials used for dental prosthetics restoration, including feldspathic ceramics, glass ceramics, zirconia-based ceramics, alumina-based ceramics, and resin-based materials, were investigated with regard to content of natural radionuclides by means of thermoluminescence beta dosimetry and gamma spectrometry. The gross beta dose rate from feldspathic and glass ceramics was about ten times higher than the background measurement, whereas resin-based materials generated negligible beta dose rate, similarly to natural tooth samples. The specific activity of uranium and thorium was significantly below the levels found in the period when addition of uranium to dental porcelain materials was still permitted. The high-beta dose levels observed in feldspathic porcelains and glass ceramics are thus mainly ascribable to (40)K, naturally present in these specimens. Although the measured values are below the recommended limits, results indicate that patients with prostheses are subject to higher dose levels than other members of the population. Alumina- and zirconia-based ceramics might be a promising alternative, as they have generally lower beta dose rates than the conventional porcelain materials. However, the dosimetry results, which imply the presence of inhomogeneously distributed clusters of radionuclides in the sample matrix, and the still unsuitable structural properties call for further optimization of these materials.


Assuntos
Materiais Dentários/química , Radioisótopos/análise , Cerâmica/análise , Doses de Radiação , Resinas Sintéticas/análise , Espectrometria gama , Dosimetria Termoluminescente
19.
Radiat Prot Dosimetry ; 119(1-4): 408-12, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16585261

RESUMO

The possibility of using a single grain OSL attachment system developed by the Risø National Laboratory (Roskilde, Denmark) for assessing the spatial distribution of radionuclides incorporated in human tissues was investigated. Detectors containing arrays of single grains of alpha-Al2O3)C powder (Landauer Inc., USA) were prepared using aluminium discs (diameter 9.7 mm), which can accommodate 100 single grains in 0.3 mm holes positioned in a 10 x 10 grid. The luminescence and dosimetric properties of each grain were investigated by exposing the detectors to uniform photon radiation fields. After the characterisation of the detectors, the systems were tested to assess the spatial dose rate distribution because of 90Sr incorporated in a tooth sample extracted from an inhabitant of the Techa River region.


Assuntos
Óxido de Alumínio/química , Óxido de Alumínio/efeitos da radiação , Radioisótopos de Estrôncio/análise , Dosimetria Termoluminescente/instrumentação , Dosimetria Termoluminescente/métodos , Dente/química , Relação Dose-Resposta à Radiação , Desenho de Equipamento , Análise de Falha de Equipamento , Estudos de Viabilidade , Humanos , Teste de Materiais , Tamanho da Partícula , Doses de Radiação
20.
Appl Radiat Isot ; 60(1): 7-13, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14687630

RESUMO

The radioisotopes of ruthenium (103Ru and 106Ru) are abundant fission products and represent a radiological risk for the population in case of nuclear accidents. Few biokinetic studies have been performed on humans up to now and consequently the current model recommended by ICRP for ruthenium is derived mainly by extrapolation from animal data. The stable isotope 101Ru and proton activation analysis have been used to study the biokinetics of Ru in blood plasma samples taken during 8 studies in three healthy volunteers. The results obtained demonstrated that complexed Ru (in the form of citrate Ru(IV) complexes) is cleared from blood plasma very rapidly (characteristic half time of 17+/-2 min), while inorganic Ru remains longer in the systemic circulation, and is transferred to other organs and/or excreted with a biological half time of 23+/-2h. Good reproducibility of the clearance curves indicated no evidence of inter- or intra-individual variability when the same Ru solution was injected in repeated experiments to different subjects.


Assuntos
Rutênio/sangue , Rutênio/farmacocinética , Adulto , Humanos , Injeções Intravenosas , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Compostos Organometálicos/sangue , Compostos Organometálicos/farmacocinética , Compostos de Rutênio/sangue , Compostos de Rutênio/farmacocinética
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