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1.
Epilepsia ; 63(6): 1500-1515, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35305025

RESUMO

OBJECTIVE: Current concepts highlight the neurological and psychological heterogeneity of functional/dissociative seizures (FDS). However, it remains uncertain whether it is possible to distinguish between a limited number of subtypes of FDS disorders. We aimed to identify profiles of distinct FDS subtypes by cluster analysis of a multidimensional dataset without any a priori hypothesis. METHODS: We conducted an exploratory, prospective multicenter study of 169 patients with FDS. We collected biographical, trauma (childhood and adulthood traumatic experiences), semiological (seizure characteristics), and psychopathological data (psychiatric comorbidities, dissociation, and alexithymia) through psychiatric interviews and standardized scales. Clusters were identified by the Partitioning Around Medoids method. The similarity of patients was computed using Gower distance. The clusters were compared using analysis of variance, chi-squared, or Fisher exact tests. RESULTS: Three patient clusters were identified in this exploratory, hypothesis-generating study and named on the basis of their most prominent characteristics: A "No/Single Trauma" group (31.4%), with more male patients, intellectual disabilities, and nonhyperkinetic seizures, and a low level of psychopathology; A "Cumulative Lifetime Traumas" group (42.6%), with clear female predominance, hyperkinetic seizures, relatively common comorbid epilepsy, and a high level of psychopathology; and A "Childhood Traumas" group (26%), commonly with comorbid epilepsy, history of childhood sexual abuse (75%), and posttraumatic stress disorder, but also with a high level of anxiety and dissociation. SIGNIFICANCE: Although our cluster analysis was undertaken without any a priori hypothesis, the nature of the trauma history emerged as the most important differentiator between three common FDS disorder subtypes. This subdifferentiation of FDS disorders may facilitate the development of more specific therapeutic programs for each patient profile.


Assuntos
Transtorno Conversivo , Epilepsia , Adulto , Transtornos Dissociativos/epidemiologia , Transtornos Dissociativos/psicologia , Epilepsia/psicologia , Feminino , Humanos , Masculino , Estudos Prospectivos , Convulsões/epidemiologia , Convulsões/psicologia
2.
Appl Radiat Isot ; 201: 110996, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37657224

RESUMO

The terbium (Tb) family has attracted much attention in recent years thanks to the diagnostic and therapeutic applications of the quadruplet 149Tb, 152Tb, 155Tb and 161Tb. However, the scarce availability of Tb radioisotopes is one of the main reasons hindering its clinical applications. To increase its availability, this work proposes to use enriched gadolinium (Gd) targets to produce some Tb radioisotopes (149Tb, 152Tb, and 155Tb) via deuteron-induced reactions in cyclotrons. The production of the Auger and gamma emitter 155Tb was chosen as a case study because the 155Gd enrichment (92.8%) is the highest available from all Gd stable isotopes. The involved reaction is 155Gd(d,2n)155Tb. Using enriched thin Gd-containing targets, cross-sections of the reactions 155Gd(d,x)153,154,155,156Tb have been measured at the GIP ARRONAX cyclotron facility with a beam energy ranging from 8 MeV to 30 MeV. This measurement allows for estimating the production yield and the purity of 155Tb, and for determining the irradiation parameters for large production batches. A thick enriched 155Gd2O3 target has been then irradiated with an incident energy of 15.1 MeV and a beam current of 368 nA for 1 h. The production yield of 155Tb is 10.2 MBq/µA/h at End Of Bombardment (EOB) and the purity is 89% after 14 days of decay. These experimental values are consistent with estimation based on measured cross-sections. A comparison of the deuteron-induced and proton-induced production routes is also presented in this paper.

3.
Appl Radiat Isot ; 186: 110287, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35597156

RESUMO

In the last years, 155Tb has attracted enormous interest due to its potential role in theranostics in nuclear medicine. To estimate its production yield, the aim of this study was to develop a method to prepare thin Gd-enriched-containing targets aimed at the 155Gd(d, 2n)155Tb nuclear cross section measurement. To this end, the electrochemical co-deposition method has been chosen to manufacture Ni-Gd2O3 composite targets. Several process parameters that have an impact on the deposit quality, have been investigated to increase the incorporation of Gd mass (up to 3 mg). To validate the concept, seven targets made by natural Gd were irradiated with deuteron beams at the GIP ARRONAX facility cyclotron, with an energy range ranging from 8 MeV to 30 MeV to extract the cross section values by using the stacked-foils method. Results obtained turned out to have great consistency with existing published data thus validating the proposed method. Therefore, an alternative target manufacturing concept aimed at cross section measurement is presented in this work.


Assuntos
Ciclotrons
4.
Front Oncol ; 12: 923679, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36419904

RESUMO

Glioblastoma is considered the most common malignant primary tumor of central nervous system. In spite of the current standard and multimodal treatment, the prognosis of glioblastoma is poor. For this reason, new therapeutic approaches need to be developed to improve the survival time of the glioblastoma patient. In this study, we performed a preclinical experiment to evaluate therapeutic efficacy of 166Ho microparticle suspension administered by microbrachytherapy on a minipig glioblastoma model. Twelve minipigs were divided in 3 groups. Minipigs had injections into the tumor, containing microparticle suspensions of either 166Ho (group 1; n = 6) or 165Ho (group 2; n = 3) and control group (group 3; n = 3). The survival time from treatment to euthanasia was 66 days with a good state of health of all minipigs in group 1. The median survival time from treatment to tumor related death were 8.6 and 7.3 days in groups 2 and control, respectively. Statistically, the prolonged life of group 1 was significantly different from the two other groups (p < 0.01), and no significant difference was observed between group 2 and control (p=0.09). Our trial on the therapeutic effect of the 166Ho microparticle demonstrated an excellent efficacy in tumor control. The histological and immunohistochemical analysis showed that the efficacy was related to a severe 166Ho induced necrosis combined with an immune response due to the presence of the radioactive microparticles inside the tumors. The absence of reflux following the injections confirms the safety of the injection device.

5.
Front Med (Lausanne) ; 8: 693682, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34336898

RESUMO

The CERN-MEDICIS (MEDical Isotopes Collected from ISolde) facility has delivered its first radioactive ion beam at CERN (Switzerland) in December 2017 to support the research and development in nuclear medicine using non-conventional radionuclides. Since then, fourteen institutes, including CERN, have joined the collaboration to drive the scientific program of this unique installation and evaluate the needs of the community to improve the research in imaging, diagnostics, radiation therapy and personalized medicine. The facility has been built as an extension of the ISOLDE (Isotope Separator On Line DEvice) facility at CERN. Handling of open radioisotope sources is made possible thanks to its Radiological Controlled Area and laboratory. Targets are being irradiated by the 1.4 GeV proton beam delivered by the CERN Proton Synchrotron Booster (PSB) on a station placed between the High Resolution Separator (HRS) ISOLDE target station and its beam dump. Irradiated target materials are also received from external institutes to undergo mass separation at CERN-MEDICIS. All targets are handled via a remote handling system and exploited on a dedicated isotope separator beamline. To allow for the release and collection of a specific radionuclide of medical interest, each target is heated to temperatures of up to 2,300°C. The created ions are extracted and accelerated to an energy up to 60 kV, and the beam steered through an off-line sector field magnet mass separator. This is followed by the extraction of the radionuclide of interest through mass separation and its subsequent implantation into a collection foil. In addition, the MELISSA (MEDICIS Laser Ion Source Setup At CERN) laser laboratory, in service since April 2019, helps to increase the separation efficiency and the selectivity. After collection, the implanted radionuclides are dispatched to the biomedical research centers, participating in the CERN-MEDICIS collaboration, for Research & Development in imaging or treatment. Since its commissioning, the CERN-MEDICIS facility has provided its partner institutes with non-conventional medical radionuclides such as Tb-149, Tb-152, Tb-155, Sm-153, Tm-165, Tm-167, Er-169, Yb-175, and Ac-225 with a high specific activity. This article provides a review of the achievements and milestones of CERN-MEDICIS since it has produced its first radioactive isotope in December 2017, with a special focus on its most recent operation in 2020.

6.
Pharmacoepidemiol Drug Saf ; 18(4): 310-9, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19241438

RESUMO

PURPOSE: Precise determination of drug exposure is fundamental in pharmacoepidemiology. Drug exposure is often presumed from health insurance claims but this may not correspond exactly to what subjects actually take. This study was designed to investigate French reimbursement databases in assessing drug use. METHODS: Between 1999 and 2001, 9294 subjects were included in the Three-City (3C) Study, a French cohort studying the relationship between vascular risk factors and dementia. Of these, 4112 subjects had data available from both clinical interviews and the reimbursement databases of the French national health insurance system. Agreement between drugs reported as used at interview and drugs reimbursed during the previous 30 or 60 days was measured with kappa coefficients. Using calculations of sensitivity (Se), specificity (Sp), positive predictive values (PPVs) and negative predictive values (NPVs), the validity of reimbursement data for the 30 or 60 days preceding the interview was investigated taking drugs reported at interview as the 'gold standard'. RESULTS: Declared drug use at interview was less well predicted by 30-day than by 60-day reimbursement data. Agreement between reimbursement data and interviews as well as validity of reimbursement data with reference to interviews were substantial for drugs used in cardiovascular diseases, diabetes, rheumatic disorders or neuropsychiatric conditions and were poor for laxatives, vitamins, vasculoprotectives, first and second line analgesics, anti-infective products or dermatologicals. CONCLUSIONS: Reimbursement data with an appropriate time frame and interviews estimate exposure to chronically used drugs similarly. Self-medication was better described with interviews whereas reimbursement data seem more useful for drugs used topically or intermittently.


Assuntos
Revisão de Uso de Medicamentos/estatística & dados numéricos , Reembolso de Seguro de Saúde/estatística & dados numéricos , Seguro de Serviços Farmacêuticos/estatística & dados numéricos , Entrevistas como Assunto , Farmacoepidemiologia/métodos , Idoso , Idoso de 80 Anos ou mais , Bases de Dados como Assunto , Feminino , França , Humanos , Masculino , Farmacoepidemiologia/estatística & dados numéricos , Estudos Prospectivos , Reprodutibilidade dos Testes , Automedicação , Fatores de Tempo
7.
Radiat Prot Dosimetry ; 183(1-2): 270-273, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30668799

RESUMO

The cyclotron ARRONAX can deliver different types of particles (protons, deuterons, alpha-particles) in an energy range up to 68 MeV. One of its six experimental halls is dedicated to studying the interactions of radiation with matter including living matter. A horizontal beamline for cell irradiation has been setup and characterized. The radiobiological characterization was done in terms of V79 cells survival after irradiation with 68 MeV protons. The results demonstrate that radiobiological studies can be successfully performed confirming the high potential of the facility.


Assuntos
Ciclotrons , Radiobiologia/instrumentação , Desenho de Equipamento , França , Humanos
8.
J Am Geriatr Soc ; 54(12): 1839-45, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17198488

RESUMO

OBJECTIVES: To describe the evolution of prevalence of depressive symptoms and antidepressant use between 1988 and 1999 in a large representative sample of older community-dwelling French people. DESIGN: Prospective cohort designed in 1988/89 to study cerebral and functional aging. SETTING: Urban and rural communities in southwestern France. PARTICIPANTS: Three thousand six hundred thirty-seven adults aged 65 and older living in noninstitutional settings at baseline. MEASUREMENTS: Participants were interviewed 3, 5, 8, and 10 years after the initial data collection. Depressive symptomatology was evaluated using a French version of the Center for Epidemiological Studies Depression Scale. Longitudinal analysis of the prevalence of depressive symptomatology was performed using a logistic mixed model adjusted for antidepressant use, sex, age, education level, living conditions, psychiatric antecedents, drug consumption, and diagnosis of dementia. RESULTS: Over the 10 years of follow-up, the prevalence of depressive symptomatology decreased from 13.8% to 8.3%. This decrease was statistically significant even after adjustment (odds ratio = 0.88 per increased year, 95% confidence interval = 0.85-0.90) and was more pronounced in subjects having reported previous depression at baseline. During the same period, antidepressant use rose from 5.2% to 11.9%, mainly due to increased use of selective serotonin reuptake inhibitors. Furthermore, the proportion of subjects who had depressive symptoms and did not use antidepressants decreased from 11.8% to 6.2%. CONCLUSION: This study suggests better management of late-life depression in the last decade and illustrates the heterogeneity of depression disorder in late life.


Assuntos
Antidepressivos/uso terapêutico , Depressão/epidemiologia , Geriatria , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Depressão/tratamento farmacológico , Feminino , França/epidemiologia , Humanos , Entrevistas como Assunto , Masculino , Prevalência , População Rural , Fatores de Tempo , População Urbana
9.
J Invest Surg ; 29(3): 157-66, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26682487

RESUMO

PURPOSE: Implant infections are severe complications in orthopedic surgery. Treatment using antibiotics is often unsuccessful without removing the implant due to biofilm formation. In this context, antiseptics may be a potential option. These solutions have a wide antimicrobial spectrum but often cause damage to the local cell populations. In these cases, electrochemically activated solutions (ECAS) may be an alternative. METHODS: Staphylococcus aureus was cultured overnight on polyethylene platelets under different growing conditions (standard-/-different biofilm inducing conditions). The samples were treated with an ECAS (0%-30%) and analyzed with regard to their antimicrobial efficacy and their effect on biofilm structures by determining the living bacterial count and scanning electron microscopy. Osteoblast and chondrocyte cell lines (MG-63, and CAL-78, respectively) were cultured to confluence and treated with an ECAS. Total cell count, metabolic activity using FDA staining, and proliferation using Ki67 staining were analyzed. RESULTS: ECAS showed antimicrobial activity in concentrations <1%. In cases of biofilm formation, bacterial toxicity could be detected at concentrations from 3.75 -7.5%. At these same concentrations, a visible change in biofilm structure was observed. Regarding biocompatibility rates, up to 7.5% (of osteoblasts) and 3.75% (of chondrocytes) had little influence on metabolic activity and proliferation. CONCLUSION: ECAS provide good antimicrobial efficacy while maintaining high biocompatibility. These results suggest that these solutions may provide promising alternatives in the treatment of implant-associated infections.


Assuntos
Anti-Infecciosos Locais/uso terapêutico , Assepsia/métodos , Condrócitos/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Infecções Relacionadas à Prótese/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Anti-Infecciosos Locais/química , Artroplastia de Substituição/efeitos adversos , Carga Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Contagem de Células , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Técnicas Eletroquímicas , Humanos , Microscopia Eletrônica de Varredura , Soluções/uso terapêutico
10.
Orthop Rev (Pavia) ; 8(1): 6360, 2016 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-27114813

RESUMO

Sport specific movements coming along with characteristic plantar pressure distribution and a fatigue of muscles result in an increasing postural sway and therefore lead to a decrease in balance control. Although single soccer specific movements were expatiated with respect to these parameters, no information is available for a complete training session. The objective of the present observational study was to analyze the direct influence of soccer training on postural stability and gait patterns and whether or not these outcomes were altered by age. One hundred and eighteen experienced soccer players participated in the study and were divided into two groups. Group 1 contained 64 soccer players (age 13.31±0.66 years) and Group 2 contains 54 ones (age 16.74±0.73 years). Postural stability, static plantar pressure distribution and dynamic foot loading patterns were measured. Our results showed that the soccer training session, as well as the age, has relevant influence on postural stability, while the age only (excluding the training) has an influence on static plantar pressure distribution. The parameters of dynamic assessment seem therefore to be affected by age, training and a combination of both. Training and young age correlate with a decreased postural stability; they lead to a significant increase of peak pressure in the previously most loaded areas, and, after reaching a certain age and magnitude of absolute values, to a change in terminal stance and preswing phase of the roll-over. Moreover, younger players show an inhomogenous static plantar pressure distribution which might be the result of the decreased postural control in the young age.

11.
Therapie ; 60(6): 561-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16555493

RESUMO

OBJECTIVE: The aim of this study was to estimate the incidence of benzodiazepine use in an elderly population and to identify associated factors. METHODS: Data were collected in four self-report questionnaires on the use of sedatives and sleeping drugs. These questionnaires were sent every 6 months, over a 2-year period, to the 1272 elderly subjects interviewed at the first follow-up examination of the EVA (Epidemiology of Vascular Aging) Study. RESULTS: The incidence rate of benzodiazepine use was 4.7 per 1000 person-months (95% confidence interval [CI] 3.6, 5.8). In multivariable analyses (logistic regression model), incident use of benzodiazepines was significantly associated with depressive or anxious symptoms (odds ratio [OR] = 3.3; 95% CI 1.7, 6.4), high use of non-psychotropic drugs (> or = 3; OR = 1.8; 95% CI 1.1, 3.1) and female gender (OR = 1.9; 95% CI 1.1, 3.3). CONCLUSION: Simultaneous use of benzodiazepines and other medications should be carefully assessed in elderly patients, considering the risk of adverse drug reactions and drug-drug interactions.


Assuntos
Idoso/estatística & dados numéricos , Envelhecimento/fisiologia , Benzodiazepinas , Sistema Cardiovascular/crescimento & desenvolvimento , Uso de Medicamentos/estatística & dados numéricos , Estudos de Coortes , França/epidemiologia , Humanos , Modelos Logísticos , Inquéritos e Questionários
12.
Front Med (Lausanne) ; 2: 31, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26029696

RESUMO

With the recent interest on the theranostic approach, there has been a renewed interest for alternative radionuclides in nuclear medicine. They can be produced using common production routes, i.e., using protons accelerated by biomedical cyclotrons or neutrons produced in research reactors. However, in some cases, it can be more valuable to use deuterons as projectiles. In the case of Cu-64, smaller quantities of the expensive target material, Ni-64, are used with deuterons as compared with protons for the same produced activity. For the Sc-44m/Sc-44g generator, deuterons afford a higher Sc-44m production yield than with protons. Finally, in the case of Re-186g, deuterons lead to a production yield five times higher than protons. These three examples show that it is of interest to consider not only protons or neutrons but also deuterons to produce alternative radionuclides.

13.
J Magn Reson ; 168(1): 118-23, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15082256

RESUMO

As a means of obtaining precise quantitative data in 2D NMR spectroscopy, the use of an electronic reference signal (ERETIC) has been examined. The results presented demonstrate that the ERETIC method can be used in different situations encountered in 2D-NMR spectroscopy: homonuclear and heteronuclear spectra, phased or magnitude mode, symmetrization. The main restriction to introducing ERETIC in 2D spectra could be the need for several spectrometer channels. However, most modern NMR spectrometers are equipped with at least three channels, that allows the implementation of the ERETIC method as reference for 2D-NMR spectroscopy without needing any hardware modification.

14.
Nucl Med Biol ; 41 Suppl: e16-8, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24342655

RESUMO

INTRODUCTION: The ARRONAX cyclotron, acronym for "Accelerator for Research in Radiochemistry and Oncology at Nantes Atlantique" is a new facility installed in Nantes, France. A dedicated program has been launched on production of innovative radioisotopes for PET imaging and for ß- and α targeted radiotherapy using protons or α particles. Since the accelerator is also able to deliver deuteron beams up to 35 MeV, we have reconsidered the possibility of using them to produce medical isotopes. Indeed, in some cases, the use of deuterons allows higher production yield than protons. METHODS: (186)Re is a ß- emitter which has chemical properties close to the widely used (99m)Tc and has been used in clinical trials for palliation of painful bone metastases resulting from prostate and breast cancer. (186)Re production cross section has been measured between 9 and 23 MeV using the ARRONAX deuteron beam and the stacked-foil technique. A novelty in our work is the use of a monitor foil behind each (nat)W target foil in order to record efficiently the deuteron incident flux and energies all over the stack relying on the International Atomic Energy Agency (IAEA) recommended cross section of the (nat)Ti(d,x)(48)V reaction. Since a good optimization process is supposed to find the best compromise between production yield and purity of the final product, isotope of interest and contaminants created during irradiation are measured using gamma spectrometry. RESULTS: Our new sets of data are presented and compared with the existing ones and with results given by the TALYS code calculations. The thick target yield (TTY) has been calculated after the fit of our experimental values and compared with the IAEA recommended ones. CONCLUSIONS: Presented values are in good agreement with existing data. The deuteron production route is clearly the best choice with a TTY of 7.8 MB/µAh at 30 MeV compared to 2.4 MBq/µAh for proton as projectile at the same energy. The TALYS code gives satisfactory results for (183,186)Re isotopes.


Assuntos
Deutério/química , Radioquímica/métodos , Radioisótopos/química , Rênio/química
15.
Nucleus (La Habana) ; (63): 1-5, Jan.-June 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-990198

RESUMO

Abstract The cross sections of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were measured at the ARRONAX facility by using the 70 MeV cyclotron, with particular attention to the production of the theranostic radionuclide 67Cu. Enriched 68Zn material was electroplated on silver backing and exposed to alow-intensity proton beam by using the stacked-foils target method. Since 67Cu and 67Ga radionuclides have similar half-lives and same γ-lines (they both decay to 67Zn), a radiochemical process aimed at Cu/Ga separation was mandatory to avoid interferences in γ-spectrometry measurements. A simple chemical procedure having a high separation efficiency (>99%)was developed and monitored during each foil processing, thanks to the tracer isotopes 61Cu and 66Ga.Nuclear cross sections were measured in the energy range 35-70 MeV by using reference reactions recommended by the International Atomic Energy Agency (IAEA) to monitor beam flux. In comparison with literature data a general good agreement on the trend of the nuclear reactions was noted, especially with latest measurements, but slightly lower values were obtained in case of 67Cu. Experimental results of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were also compared with the theoretical values estimated by using the nuclear reaction code TALYS. The production yield of the theranostic radionuclide 67Cu was estimated considering the results obtained in this work.


Resumen Las secciones eficaces de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga se midieron en la instalación ARRONAX utilizando el ciclotrón 70 MeV, con especial atención a la producción del radionucleidos teranóstico 67Cu. El material enriquecido 68Zn se galvanizó sobre soporte de plata y se expuso a un haz de protones de baja intensidad utilizando un blanco de láminas apiladas. Como los radionucleidos 67Cu y 67Ga tienen periodos de semidesintegración y líneas γ similares (ambos se desintegran a 67Zn), un proceso radioquímico dirigido a la separación Cu / Ga fue obligatorio para evitar interferencias en las mediciones de espectrometría γ. Se desarrolló un procedimiento químico simple con una alta eficiencia de separación (> 99%) durante cada procesamiento de la lámina, gracias a los isótopos trazadores 61Cu y 66Ga. Las secciones eficaces nucleares se midieron en el rango de energía de 35-70 MeV utilizando reacciones de referencia recomendadas por el Organismo Internacional de Energía Atómica (OIEA) para monitorear el flujo del haz. Al comparar con los datos de la literatura, se observó una buena concordancia en general con la tendencia de las reacciones nucleares, particularmente con las últimas mediciones, pero se obtuvieron valores ligeramente inferiores en el caso de 67Cu. Los resultados experimentales de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga también se compararon con los valores teóricos estimados usando el código de reacción nuclear TALYS. El rendimiento de producción del radionucleido teranóstico 67Cu se estimó considerando los resultados obtenidos en este trabajo.

16.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1506786

RESUMO

The cross sections of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were measured at the ARRONAX facility by using the 70 MeV cyclotron, with particular attention to the production of the theranostic radionuclide 67Cu. Enriched 68Zn material was electroplated on silver backing and exposed to alow-intensity proton beam by using the stacked-foils target method. Since 67Cu and 67Ga radionuclides have similar half-lives and same γ-lines (they both decay to 67Zn), a radiochemical process aimed at Cu/Ga separation was mandatory to avoid interferences in γ-spectrometry measurements. A simple chemical procedure having a high separation efficiency (>99%)was developed and monitored during each foil processing, thanks to the tracer isotopes 61Cu and 66Ga.Nuclear cross sections were measured in the energy range 35-70 MeV by using reference reactions recommended by the International Atomic Energy Agency (IAEA) to monitor beam flux. In comparison with literature data a general good agreement on the trend of the nuclear reactions was noted, especially with latest measurements, but slightly lower values were obtained in case of 67Cu. Experimental results of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were also compared with the theoretical values estimated by using the nuclear reaction code TALYS. The production yield of the theranostic radionuclide 67Cu was estimated considering the results obtained in this work.


Las secciones eficaces de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga se midieron en la instalación ARRONAX utilizando el ciclotrón 70 MeV, con especial atención a la producción del radionucleidos teranóstico 67Cu. El material enriquecido 68Zn se galvanizó sobre soporte de plata y se expuso a un haz de protones de baja intensidad utilizando un blanco de láminas apiladas. Como los radionucleidos 67Cu y 67Ga tienen periodos de semidesintegración y líneas γ similares (ambos se desintegran a 67Zn), un proceso radioquímico dirigido a la separación Cu / Ga fue obligatorio para evitar interferencias en las mediciones de espectrometría γ. Se desarrolló un procedimiento químico simple con una alta eficiencia de separación (> 99%) durante cada procesamiento de la lámina, gracias a los isótopos trazadores 61Cu y 66Ga. Las secciones eficaces nucleares se midieron en el rango de energía de 35-70 MeV utilizando reacciones de referencia recomendadas por el Organismo Internacional de Energía Atómica (OIEA) para monitorear el flujo del haz. Al comparar con los datos de la literatura, se observó una buena concordancia en general con la tendencia de las reacciones nucleares, particularmente con las últimas mediciones, pero se obtuvieron valores ligeramente inferiores en el caso de 67Cu. Los resultados experimentales de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga también se compararon con los valores teóricos estimados usando el código de reacción nuclear TALYS. El rendimiento de producción del radionucleido teranóstico 67Cu se estimó considerando los resultados obtenidos en este trabajo.

17.
Science ; 336(6078): 217-20, 2012 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-22438510

RESUMO

Laser altimetry by the MESSENGER spacecraft has yielded a topographic model of the northern hemisphere of Mercury. The dynamic range of elevations is considerably smaller than those of Mars or the Moon. The most prominent feature is an extensive lowland at high northern latitudes that hosts the volcanic northern plains. Within this lowland is a broad topographic rise that experienced uplift after plains emplacement. The interior of the 1500-km-diameter Caloris impact basin has been modified so that part of the basin floor now stands higher than the rim. The elevated portion of the floor of Caloris appears to be part of a quasi-linear rise that extends for approximately half the planetary circumference at mid-latitudes. Collectively, these features imply that long-wavelength changes to Mercury's topography occurred after the earliest phases of the planet's geological history.

18.
Nucl Med Rev Cent East Eur ; 14(2): 90-5, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22219149

RESUMO

During the carcinogenesis process, tumour cells often have a more rapid proliferation potential than cells that participate in blood capillary formation by neoangiogenesis. As a consequence of the poorly organized vasculature of various solid tumours, a limited oxygen delivery is observed. This hypoxic mechanism frequently occurs in solid cancers and can lead to therapeutic resistance. The present selected literature review is focused on the comparison of two positron emitting radiopharmaceuticals agents, which are currently leaders in tumour hypoxia imaging by PET. {18F}-fluoromisonidazole (=FMISO) is most commonly used as an investigational PET agent with an investigational new drug exemption from the FDA, while {64Cu}-diacetyl-bis(N4-methylthiosemicarbazone) (64Cu-ATSM) has been presented as an alternative radiopharmaceutical not yet readily available. The comparison of these two radiopharmaceutical agents is particularly focused on isotope properties, radiopharmaceutical labelling process, pharmacological mechanisms, dosimetry data in patients, and clinical results in terms of image contrast. PET imaging has demonstrated a good efficacy in tumour hypoxia imaging with both FMISO and Cu-ATSM, but FMISO has presented too slow an in vivo accumulation and a weak image contrast of the hypoxia area. Despite a less favourable dosimetry, 64Cu-ATSM appears superior in terms of imaging performance, calling for industrial and clinical development of this innovative radiopharmaceutical.


Assuntos
Radioisótopos de Cobre/farmacologia , Misonidazol/análogos & derivados , Neoplasias/diagnóstico por imagem , Compostos Organometálicos/farmacologia , Tomografia por Emissão de Pósitrons/métodos , Radiossensibilizantes/farmacologia , Tiossemicarbazonas/farmacologia , Hipóxia Celular , Complexos de Coordenação , Humanos , Misonidazol/farmacologia
19.
Eur J Nucl Med Mol Imaging ; 35(7): 1377-87, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18465127

RESUMO

PURPOSE: This study was aimed at establishing a list of radionuclides of interest for nuclear medicine that can be produced in a high-intensity and high-energy cyclotron. METHODS: We have considered both therapeutic and positron emission tomography radionuclides that can be produced using a high-energy and a high-intensity cyclotron such as ARRONAX, which will be operating in Nantes (France) by the end of 2008. Novel radionuclides or radionuclides of current limited availability have been selected according to the following criteria: emission of positrons, low-energy beta or alpha particles, stable or short half-life daughters, half-life between 3 h and 10 days or generator-produced, favourable dosimetry, production from stable isotopes with reasonable cross sections. RESULTS: Three radionuclides appear well suited to targeted radionuclide therapy using beta ((67)Cu, (47)Sc) or alpha ((211)At) particles. Positron emitters allowing dosimetry studies prior to radionuclide therapy ((64)Cu, (124)I, (44)Sc), or that can be generator-produced ((82)Rb, (68)Ga) or providing the opportunity of a new imaging modality ((44)Sc) are considered to have a great interest at short term whereas (86)Y, (52)Fe, (55)Co, (76)Br or (89)Zr are considered to have a potential interest at middle term. CONCLUSIONS: Several radionuclides not currently used in routine nuclear medicine or not available in sufficient amount for clinical research have been selected for future production. High-energy, high-intensity cyclotrons are necessary to produce some of the selected radionuclides and make possible future clinical developments in nuclear medicine. Associated with appropriate carriers, these radionuclides will respond to a maximum of unmet clinical needs.


Assuntos
Ciclotrons/instrumentação , Medicina Nuclear/instrumentação , Radioisótopos/isolamento & purificação , Partículas alfa/uso terapêutico , Partículas beta/uso terapêutico , Desenho de Equipamento , França , Meia-Vida , Humanos , Física Nuclear/instrumentação , Tomografia por Emissão de Pósitrons , Radioisótopos/uso terapêutico , Compostos Radiofarmacêuticos/isolamento & purificação , Compostos Radiofarmacêuticos/uso terapêutico
20.
Pharmacoepidemiol Drug Saf ; 15(7): 504-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16496429

RESUMO

PURPOSE: To describe the use of psychotropic drugs in children aged 0-5 years, in the Aquitaine region of South-west France and identify associated socio-demographic, familial and medical factors. METHODS: Data used in this study come from the regional drug claims database of the National Health Insurance System of Aquitaine and from postal self-questionnaires sent to parents and prescribing physicians. RESULTS: In Aquitaine, psychotropic drugs were redeemed at least once in 2002 for 3.2% of young children. Hydroxyzine, niaprazide or diazepam were claimed at least once by 2.7% of children registered in the database. Prescribers were mostly general practitioners (76.7%) and pediatricians (20.1%). Psychotropic claims were more frequent in children having the highest number of medical consultations in 2002 (more than 7: odds ratio (OR) = 1.5 [95% confidence interval (CI): 1.3-1.7]) or of drug deliveries (7-15 deliveries: OR = 1.8 [95%CI: 1.6-2.1]; more than 15 deliveries: OR = 3.2 [95%CI: 2.7-3.9]). Psychotropic claim frequency increased with age. No association of psychotropic use with parental psychotropic use, socio-professional category and familial situation was found. CONCLUSIONS: Psychotropic delivery prevalence in Aquitaine in young children was below 5% in 2002. It notably concerned drugs of which the use is not devoid of toxicity because of anticholinergic properties.


Assuntos
Uso de Medicamentos/estatística & dados numéricos , Psicotrópicos/uso terapêutico , Fatores Etários , Pré-Escolar , Feminino , França , Humanos , Lactente , Recém-Nascido , Masculino , Prevalência , Inquéritos e Questionários
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