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1.
Exp Aging Res ; 46(1): 52-67, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31739753

RESUMO

Back-Ground/Study Context: The goal of this study was to examine how repeated practice of an inhibition test could improve performance in the test in young and older adults. In particular, we wished to explore whether the gains made during a practice program varied between age groups, and how educational level influenced practice-related gains in older adults. Thus, we tried to disentangle two hypotheses explaining the benefits of practice, namely compensation (greater gain by the lowest performers) and magnification (greater gain by the highest performers).Method: Thirty-three younger adults and 60 older adults were divided into two groups each: (1) Groups in the Practice condition had 10 sessions practicing different versions of Card C of the Stroop Test, (2) groups in the Control condition completed only the pretest and posttest.Results: Overall, results showed that the performance of both young and older adults improved more in the practice condition than in the control condition. The older adults benefited more from practice than the young adults, with earlier and more regular improvement over the 10 sessions. Moreover, the older adults with a higher educational level benefited most.Discussion: These findings seem to support both the compensation and the magnification hypotheses, depending on the variable (age or educational level).


Assuntos
Envelhecimento/psicologia , Teste de Stroop , Adulto , Idoso , Idoso de 80 Anos ou mais , Escolaridade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
2.
Eur J Nucl Med Mol Imaging ; 46(7): 1506-1517, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30715571

RESUMO

PURPOSE: This study sought to provide preliminary results on the biodistribution and dosimetry following intra-arterial liver injection of 188Re-SSS Lipiodol on hepatocellular carcinoma patients included in the Phase I Lip-Re 1 study. METHODS: Results of the first six patients included are reported. Analysis of the 188Re-SSS Lipiodol biodistribution was based on planar scintigraphic and tomoscintigraphic (SPECT) studies performed at 1, 6, 24, 48, and 72 h post-administration. Quantification in blood, urine, and stool samples was performed. Determination of the tumour to non-tumour uptake ratio (T/NT) was calculated. Absorbed doses to target organs and tumours were evaluated using the MIRD formalism. RESULTS: The mean injected activity of 188Re-SSS Lipiodol was 1645 ± 361 MBq. Uptakes were seen in the liver (tumour and healthy liver) and the lungs only. All these uptakes were stable over time. A mean 1.4 ± 0.7% of 188Re-SSS Lipiodol administered was detected in serum samples at 6 h, declining rapidly thereafter. On average, 1.5 ± 1.6% of administered activity was eliminated in urine and feces over 72 h. Overall, 90.7 ± 1.6% of detected activity on SPECT studies was found in the liver (74.9 ± 1.8% in tumours and 19.1 ± 1.7% in the healthy liver) and 9.3 ± 1.6% in the lungs (5.7 ± 1.1% in right and 3.7 ± 0.5% in left lungs). Mean doses absorbed were 7.9 ± 3.7Gy to the whole liver, 42.7 ± 34.0Gy to the tumours, 10.2 ± 3.7Gy to the healthy liver, and 1.5 ± 1.2Gy to the lungs. Four patients had stable disease on CT scans at 2 months. The first patient with rapidly progressive disease died at 1 month, most probably of massive tumour progression. Due to this early death and using a conservative approach, the trial independent evaluation committee decided to consider this event as a treatment-related toxicity. CONCLUSION: 188Re-SSS Lipiodol has a favorable biodistribution profile concerning radioembolization, with the highest in-vivo stability among all radiolabeled Lipiodol compounds reported to date. These preliminary results must be further confirmed while completing this Phase I Lip Re1 study.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/terapia , Embolização Terapêutica/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/terapia , Fígado/diagnóstico por imagem , Idoso , Progressão da Doença , Combinação de Medicamentos , Feminino , Humanos , Injeções Intra-Arteriais , Óleo Iodado , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos , Estudos Prospectivos , Radiometria , Compostos Radiofarmacêuticos/uso terapêutico , Distribuição Tecidual , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X
3.
Neurobiol Learn Mem ; 132: 18-28, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27131744

RESUMO

The vast majority of people experience musical imagery, the sensation of reliving a song in absence of any external stimulation. Internal perception of a song can be deliberate and effortful, but also may occur involuntarily and spontaneously. Moreover, musical imagery is also involuntarily used for automatically completing missing parts of music or lyrics from a familiar song. The aim of our study was to explore the onset of musical imagery dynamics that leads to the automatic completion of missing lyrics. High-density electroencephalography was used to record the cerebral activity of twenty healthy volunteers while they were passively listening to unfamiliar songs, very familiar songs, and songs previously listened to for two weeks. Silent gaps inserted into these songs elicited a series of neural activations encompassing perceptual, attentional and cognitive mechanisms (range 100-500ms). Familiarity and learning effects emerged as early as 100ms and lasted 400ms after silence occurred. Although participants reported more easily mentally imagining lyrics in familiar rather than passively learnt songs, the onset of neural mechanisms and the power spectrum underlying musical imagery were similar for both types of songs. This study offers new insights into the musical imagery dynamics evoked by gaps of silence and on the role of familiarity and learning processes in the generation of these dynamics. The automatic and effortless method presented here is a potentially useful tool to understand failure in the familiarity and learning processes of pathological populations.


Assuntos
Percepção Auditiva/fisiologia , Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Potenciais Evocados/fisiologia , Imaginação/fisiologia , Aprendizagem/fisiologia , Música/psicologia , Poesia como Assunto , Reconhecimento Psicológico/fisiologia , Adulto , Feminino , Humanos , Masculino
4.
Aging Ment Health ; 19(3): 264-73, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24954009

RESUMO

OBJECTIVES: Although several reported studies have suggested that younger adults with depression display depression-related biases during the processing of emotional faces, there remains a lack of data concerning these biases in older adults. The aim of our study was to assess scanning behavior during the processing of emotional faces in depressed older adults. METHOD: Older adults with and without depression viewed happy, neutral or sad portraits during an eye movement recording. RESULTS: Depressed older adults spent less time with fewer fixations on emotional features than healthy older adults, but only for sad and neutral portraits, with no significant difference for happy portraits. CONCLUSION: These results suggest disengagement from sad and neutral faces in depressed older adults, which is not consistent with standard theoretical proposals on congruence biases in depression. Also, aging and associated emotional regulation change may explain the expression of depression-related biases. Our preliminary results suggest that information processing in depression consists of a more complex phenomenon than merely a general searching for mood-congruent stimuli or general disengagement from all kinds of stimuli. These findings underline that care must be used when evaluating potential variables, such as aging, which interact with depression and selectively influence the choice of relevant stimulus dimensions.


Assuntos
Envelhecimento/fisiologia , Transtorno Depressivo Maior/fisiopatologia , Emoções/fisiologia , Expressão Facial , Reconhecimento Visual de Modelos/fisiologia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/psicologia , Medições dos Movimentos Oculares , Feminino , Humanos , Masculino
5.
Nanomaterials (Basel) ; 11(4)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918663

RESUMO

Recently, short synthetic peptides have gained interest as targeting agents in the design of site-specific nanomedicines. In this context, our work aimed at developing new tools for the diagnosis and/or therapy of hepatocellular carcinoma (HCC) by grafting the hepatotropic George Baker (GB) virus A (GBVA10-9) and Plasmodium circumsporozoite protein (CPB)-derived peptides to the biocompatible poly(benzyl malate), PMLABe. We successfully synthesized PMLABe derivatives end-functionalized with peptides GBVA10-9, CPB, and their corresponding scrambled peptides through a thiol/maleimide reaction. The corresponding nanoparticles (NPs), varying by the nature of the peptide (GBVA10-9, CPB, and their scrambled peptides) and the absence or presence of poly(ethylene glycol) were also successfully formulated using nanoprecipitation technique. NPs were further characterized by dynamic light scattering (DLS), electrophoretic light scattering (ELS) and transmission electron microscopy (TEM), highlighting a diameter lower than 150 nm, a negative surface charge, and a more or less spherical shape. Moreover, a fluorescent probe (DiD Oil) has been encapsulated during the nanoprecipitation process. Finally, preliminary in vitro internalisation assays using HepaRG hepatoma cells demonstrated that CPB peptide-functionalized PMLABe NPs were efficiently internalized by endocytosis, and that such nanoobjects may be promising drug delivery systems for the theranostics of HCC.

6.
Front Psychol ; 12: 712347, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858252

RESUMO

Suicidal behaviors (SBs) are often associated with impaired performance on neuropsychological executive functioning (EF) measures that encourage the development of more specific and reliable tools. Recent evidence could suggest that saccadic movement using eye tracking can provide reliable information on EF in depressive elderly. The aim of this study was to describe oculomotor performances in elderly depressed patients with SB. To achieve this aim, we compared saccadic eye movement (SEM) performances in elderly depressed patients (N = 24) with SB and with no SB in prosaccade (PS) and antisaccade (AS) tasks under the gap, step, and overlap conditions. All participants also underwent a complete neuropsychological battery. Performances were impaired in patients with SB who exhibited less corrected AS errors and longer time to correct them than patients with no SB. Moreover, both groups had a similar performance for PS latencies and correct AS. These preliminary results suggested higher cognitive inflexibility in suicidal patients compared to non-suicidal. This inflexibility may explain the difficulty of the depressed elderly in generating solutions to the resurgence of suicidal ideation (SI) to respond adequately to stressful environments. The assessment of eye movement parameters in depressed elderly patients may be a first step in identifying high-risk patients for suicide.

7.
Front Psychol ; 12: 724731, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34675839

RESUMO

Late-Life Depression (LLD) is often associated with cognitive impairment. However, distinction between cognitive impairment due to LLD and those due to normal aging or mild Alzheimer's Disease (AD) remain difficult. The aim of this study was to present and compare the multivariate base rates of low scores in LLD, mild AD, and healthy control groups on a battery of neuropsychological tests. Participants (ages 60-89) were 352 older healthy adults, 390 patients with LLD, and 234 patients with mild AD (i.e., MMSE ≥ 20). Multivariate base rates of low scores (i.e., ≤ 5th percentile) were calculated for each participant group within different cognitive domains (verbal episodic memory, executive skills, mental processing speed, constructional praxis, and language/semantic memory). Obtaining at least one low score was relatively common in healthy older people controls (from 9.4 to 17.6%), and may thus result in a large number of false positives. By contrast, having at least two low scores was unusual (from 0.3 to 4.6%) and seems to be a more reliable criterion for identifying cognitive impairment in LLD. Having at least three low memory scores was poorly associated with LLD (5.9%) compared to mild AD (76.1%) and may provide a useful way to differentiate between these two conditions [ χ ( 1 ) 2 = 329.8, p < 0.001; Odds Ratio = 50.7, 95% CI = 38.2-77.5]. The multivariate base rate information about low scores in healthy older people and mild AD may help clinicians to identify cognitive impairments in LLD patients, improve the clinical decision-making, and target those who require regular cognitive and clinical follow-up.

8.
Geriatr Psychol Neuropsychiatr Vieil ; 17(1): 92-98, 2019 03 01.
Artigo em Francês | MEDLINE | ID: mdl-30907373

RESUMO

Elderly people, especially those with depression, represent the population most at risk for suicide. In addition to commonly used neuropsychological, psychiatric and biological tests, ocular saccadic analysis can be an interesting tool for identifying suicidal behaviors (SB). These SBs could be associated with an alteration of the cortical structures involved in the executive functions. This alteration is particularly manifested by a decrease in the ability to control eye movements (EM). Thus, depressed elderly people with SB may have a greater impairment of oculomotor performance than those without SB. The purpose of this article is to summarize the literature allowing us to support this hypothesis.


Assuntos
Depressão/diagnóstico , Depressão/psicologia , Movimentos Sacádicos , Ideação Suicida , Idoso , Idoso de 80 Anos ou mais , Movimentos Oculares , Feminino , Humanos , Masculino , Músculos Oculomotores/fisiopatologia , Suicídio/psicologia
9.
Front Med (Lausanne) ; 6: 132, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31259173

RESUMO

Rhenium-188 (188Re) is a high energy beta-emitting radioisotope with a short 16.9 h physical half-life, which has been shown to be a very attractive candidate for use in therapeutic nuclear medicine. The high beta emission has an average energy of 784 keV and a maximum energy of 2.12 MeV, sufficient to penetrate and destroy targeted abnormal tissues. In addition, the low-abundant gamma emission of 155 keV (15%) is efficient for imaging and for dosimetric calculations. These key characteristics identify 188Re as an important therapeutic radioisotope for routine clinical use. Moreover, the highly reproducible on-demand availability of 188Re from the 188W/188Re generator system is an important feature and permits installation in hospital-based or central radiopharmacies for cost-effective availability of no-carrier-added (NCA) 188Re. Rhenium-188 and technetium-99 m exhibit similar chemical properties and represent a "theranostic pair." Thus, preparation and targeting of 188Re agents for therapy is similar to imaging agents prepared with 99mTc, the most commonly used diagnostic radionuclide. Over the last three decades, radiopharmaceuticals based on 188Re-labeled small molecules, including peptides, antibodies, Lipiodol and particulates have been reported. The successful application of these 188Re-labeled therapeutic radiopharmaceuticals has been reported in multiple early phase clinical trials for the management of various primary tumors, bone metastasis, rheumatoid arthritis, and endocoronary interventions. This article reviews the use of 188Re-radiopharmaceuticals which have been investigated in patients for cancer treatment, demonstrating that 188Re represents a cost effective alternative for routine clinical use in comparison to more expensive and/or less readily available therapeutic radioisotopes.

10.
Arch Clin Neuropsychol ; 33(1): 1-13, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28525567

RESUMO

OBJECTIVE: Several studies have demonstrated saccadic eye movement (SEM) abnormalities in Alzheimer's disease (AD) when patients performed prosaccade (PS) and antisaccade (AS) tasks. Some studies have also showed that SEM abnormalities were correlated with dementia rating tests such as the Mini Mental State Evaluation (MMSE). Therefore, it has been suggested that SEMs could provide useful information for diagnosis. However, little is known about predictive saccades (PreS)-saccades triggered before or very quickly after stimuli appearance-and their relationships with cognition in AD. Here, we aimed to examine the relationships between our usual dementia screening tests and SEM parameters in PS, AS, and also PreS task. METHOD: We compared SEMs in 20 patients suffering from AD and in 35 healthy older adults (OA) in PS, AS, and PreS task. All participants also completed a neuropsychological evaluation. RESULTS: We showed that AD patients had higher latency and latency variability regardless the tasks, and also higher AS cost, in comparison with OA. Moreover, AD patients made more uncorrected AS and took more time-to-correct incorrect AS. In PreS task, AD patients showed higher gain and gain variability than OA when they made anticipated saccades. Close relationships were found between the majority of SEM variables in PS, AS, and PreS tasks and dementia screening tests, especially the MMSE and episodic memory measures. CONCLUSION: Our findings, in agreement with previous studies, demonstrated that AD affects several SEM parameters. SEM abnormalities may reflect selective and executive-attention impairments in AD.


Assuntos
Doença de Alzheimer/fisiopatologia , Movimentos Sacádicos/fisiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/psicologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Desempenho Psicomotor
11.
Int J Psychophysiol ; 125: 50-56, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29474854

RESUMO

One of the most basic and person-specific affective responses to music is liking. The present investigation sought to determine whether liking was preserved during spontaneous auditory imagery. To this purpose, we inserted two-second silent intervals into liked and disliked songs, a method known to automatically recreate a mental image of these songs. Neural correlates of musical preference were measured by high-density electroencephalography in twenty subjects who had to listen to a set of five pre-selected unknown songs the same number of times for two weeks. Time frequency analysis of the two most liked and the two most disliked songs confirmed the presence of neural responses related to liking. At the beginning of silent intervals (400-900 ms and 1000-1300 ms), significant differences in theta activity were originating from the inferior frontal and superior temporal gyrus. These two brain structures are known to work together to process various aspects of music and are also activated when measuring liking while listening to music. At the end of silent intervals (1400-1900 ms), significant alpha activity differences originating from the insula were observed, whose exact role remains to be explored. Although exposure was controlled for liked and disliked songs, liked songs were rated as more familiar, underlying the strong relationship that exists between liking, exposure, and familiarity.


Assuntos
Percepção Auditiva/fisiologia , Comportamento de Escolha/fisiologia , Imaginação/fisiologia , Música , Reconhecimento Psicológico/fisiologia , Estimulação Acústica , Adulto , Mapeamento Encefálico , Eletroencefalografia , Potenciais Evocados Auditivos/fisiologia , Feminino , Humanos , Masculino , Fatores de Tempo
12.
Artigo em Inglês | MEDLINE | ID: mdl-27726480

RESUMO

Although the relationship between age-related cognitive decline and saccadic eye movement (SEM) deficits has been outlined, specific cognitive alterations underlying age-related changes in saccadic performance remain unclear. This study attempted to better understand the nature of aging effects on SEMs. We compared SEMs in younger and older adults in prosaccade (PS) and antisaccade (AS) tasks under gap, step, and overlap conditions. We also examined relationships between these performances and several neuropsychological scores. Twenty-eight younger adults (YA), 24 older adults under 65 years (OA<65) and 24 over 65 years (OA>65) of age completed a neuropsychological evaluation, PS and AS tasks. Our results showed that latencies, AS cost, time to correct AS errors, and uncorrected AS, increased with aging. YA showed higher overlap effects than OA>65 and OA<65. Importantly, correlations and regressions revealed close relationships not only between latencies and processing speed measures but also between the AS cost and the inhibition process measures. Correct saccades and the time to correct AS errors were closely related to the inhibition process and cognitive flexibility measures. These findings suggest that the progressive age-related decline of processing speed and executive attention are associated with, and can be highlighted though SEMs in PS and AS tasks.


Assuntos
Envelhecimento/psicologia , Cognição , Movimentos Sacádicos , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Análise de Variância , Medições dos Movimentos Oculares , Feminino , Humanos , Inibição Psicológica , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Análise de Regressão
13.
Nucl Med Commun ; 27(4): 363-9, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16531923

RESUMO

BACKGROUND AND AIM: It has been shown that the use of a cocktail of isotopes of different ranges of action leads to an increase in the effectiveness of metabolic radiotherapy. The purpose of the present study was to compare with a control group the effectiveness of three different treatments in rats bearing hepatocellular carcinoma (HCC), using (1) a mixture of lipiodol labelled with both I and Re, (2) lipiodol labelled with I alone and (3) lipiodol labelled with Re alone. MATERIAL AND METHODS: Four groups were made up, each containing 14 rats with the N1-S1 tumour cell line. Group 1 received a mixture composed of 22 MBq of Re-SSS lipiodol and 7 MBq I-lipiodol. Group 2 received 14 MBq I-lipiodol. Group 3 received 44 MBq of Re-SSS lipiodol and group 4 acted as the control. The survival of the various groups was compared by a non-parametric test of log-rank, after a follow-up of 60, 180 and 273 days. RESULTS: Compared with the controls, the rats treated with a mixture of Re-SSS lipiodol and I-lipiodol show an increase in survival, but only from day 60 onwards (P=0.05 at day 60 and 0.13 at days 180 and 273). For the rats treated with I-lipiodol, there was a highly significant increase in survival compared with the controls at day 60, day 180 and day 273 (P=0.03, 0.04 and 0.04, respectively). There is no significant increase in survival for the rats treated with Re-SSS lipiodol, irrespective of the follow-up duration (P=0.53 at day 60, 0.48 at day 180, and 0.59 at day 273). CONCLUSIONS: In this study, I-lipiodol is the most effective treatment in HCC-bearing rats, because this is the only method that leads to a prolonged improvement of survival. These results cannot necessarily be extrapolated to humans because of the relatively small size and unifocal nature of the lesions in this study. It appears necessary to carry out a study in humans with larger tumours in order to compare these three treatments, particularly with a view to replacing I-labelled lipiodol by Re-labelled lipiodol. However, this study clearly demonstrated that, for small tumours, as in an adjuvant setting for example, I-labelled lipiodol should be a better option than Re-labelled lipiodol.


Assuntos
Carcinoma Hepatocelular/radioterapia , Radioisótopos do Iodo/administração & dosagem , Óleo Iodado/administração & dosagem , Neoplasias Hepáticas/radioterapia , Compostos Organometálicos/administração & dosagem , Taxa de Sobrevida , Animais , Combinação de Medicamentos , Feminino , Prognóstico , Compostos Radiofarmacêuticos/administração & dosagem , Ratos , Ratos Sprague-Dawley , Análise de Sobrevida , Resultado do Tratamento
14.
Front Psychol ; 6: 1809, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26696915

RESUMO

BACKGROUND: The analysis of eye movements (EM) by eye-tracking has been carried out for several decades to investigate mood regulation, emotional information processing, and psychomotor disturbances in depressive disorders. METHOD: A systematic review of all English language PubMed articles using the terms "saccadic eye movements" OR "eye-tracking" AND "depression" OR "bipolar disorders" was conducted using PRISMA guidelines. The aim of this review was to characterize the specific alterations of EM in unipolar and bipolar depression. RESULTS: Findings regarding psychomotor disturbance showed an increase in reaction time in prosaccade and antisaccade tasks in both unipolar and bipolar disorders. In both disorders, patients have been reported to have an attraction for negative emotions, especially for negative pictures in unipolar and threatening images in bipolar disorder. However, the pattern could change with aging, elderly unipolar patients disengaging key features of sad and neutral stimuli. METHODological limitations generally include small sample sizes with mixed unipolar and bipolar depressed patients. CONCLUSION: Eye movement analysis can be used to discriminate patients with depressive disorders from controls, as well as patients with bipolar disorder from patients with unipolar depression. General knowledge concerning psychomotor alterations and affective regulation strategies associated with each disorder can also be gained thanks to the analysis. Future directions for research on eye movement and depression are proposed in this review.

15.
Psychiatry Res ; 228(3): 576-84, 2015 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-26163722

RESUMO

Emotional pictures are commonly used as visual stimuli in a number of research fields. Choosing relevant visual stimuli to induce emotion is fundamental in attachment and affective research. Attachment theory provides a theoretical basis for the understanding of emotional and relational problems, and is especially related to two specific emotions: distress and comfort. The lack of normalized visual stimuli soliciting these attachment-related emotions has led us to create and validate a new photographic database: the Besançon Affective Picture Set-Adolescents. This novel stimulus set is composed of 93 photographs, divided into four categories: distress, comfort, joy-complicity and neutral. A group of 140 adolescents rated the pictures with the Self-Assessment Manikin system, yielding three dimensions: valence, emotional arousal, and dominance. The pictures were also assessed, using a continuous scale, for different emotions (distress, hate, horror, comfort, complicity and joy). The ANOVAs for arousal and the Kruskal-Wallis tests for valence and dominance showed strong effects for category. However, for comfort and complicity, the dimensions of valence and dominance were not significantly different, while results for arousal showed no significant difference between complicity and distress. Our study provides a tool that allows researchers to select visual stimuli to investigate attachment-related emotion processing in adolescence.


Assuntos
Nível de Alerta , Bases de Dados Factuais , Emoções , Expressão Facial , Apego ao Objeto , Reconhecimento Visual de Modelos , Adolescente , Inteligência Emocional , Feminino , Humanos , Masculino
16.
Front Med (Lausanne) ; 2: 63, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26389121

RESUMO

INTRODUCTION: Encapsulation of biologically active molecules into nanoparticles (NPs), for site-specific delivery, is a fast growing area. These NPs must be biocompatible, non-toxic, and able to release their load in a controlled way. We have developed a series of NPs based on (bio)degradable and biocompatible poly(malic acid) derivatives, poly(benzyl malate) (PMLABe), with its PEG-grafted stealth analog and target-specific biotin-PEG-b-PMLABe one. A lipophilic radiotracer has then been encapsulated into these NPs. METHODS: Monomers were synthesized from dl-aspartic acid. PEG42-b-PMLABe73 and Biot-PEG66-b-PMLABe73 block copolymers were obtained by anionic ring-opening polymerization of benzyl malolactonate in presence of α-methoxy-ω-carboxy-PEG42 and α-biotin-ω-carboxy-PEG66 as initiators. NPs were prepared by nanoprecipitation. Size, polydispersity, and zeta potential were measured by dynamic light scattering (DLS) and zetametry. (99m)Tc-SSS was prepared as previously described. Encapsulation efficacy was assessed by varying different parameters, such as encapsulation with preformed NPs or during their formation, influence of the solvent, and of the method to prepare the NPs. After decay, (99m)Tc-loaded NPs were also analyzed by DLS and zetametry. NPs' morphology was assessed by transmission electron microscopy. RESULTS: (99m)Tc-SSS was added during nanoprecipitation, using two different methods, to ensure good encapsulation. Radiolabeled NPs present increased diameters, with identical low polydispersity indexes and negative zeta potentials in comparison to non-radiolabeled NPs. CONCLUSION: A radiotracer was successfully encapsulated, but some further optimization is still needed. The next step will be to modify these radiolabeled NPs with a hepatotrope peptide, and to replace (99m)Tc with (188)Re for therapy. Our team is also working on drugs' encapsulation and grafting of a fluorescent probe. Combining these modalities is of interest for combined chemo-/radiotherapy, bimodal imaging, and/or theranostic approach.

17.
Nucl Med Commun ; 25(10): 1007-13, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15381868

RESUMO

BACKGROUND: Although intra-arterial radiation therapy with 131I-lipiodol is a useful therapeutic approach to the treatment of hepatocellular carcinoma, various disadvantages limit its use. AIM: To describe the development of a method for the labelling of lipiodol with 188Re-SSS (188Re (S2CPh)(S3CPh)2 complex) and to investigate its biodistribution after injection into the hepatic artery of rats with hepatoma. METHODS: 188Re-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with 188Re, in cold lipiodol. The radiochemical purity (RCP) of labelling was checked immediately. The 188Re-SSS lipiodol was injected into the hepatic artery of nine rats with a Novikoff hepatoma. They were sacrificed 1, 24 and 48 h after injection, and used for ex vivo counting. RESULTS: Labelling of 188Re-SSS lipiodol was achieved with a yield of 97.3+/-2.1%. The immediate RCP was 94.1+/-1.7%. Ex vivo counting confirmed a predominantly hepatic uptake, with a good tumoral retention of 188Re-SSS lipiodol, a weak pulmonary uptake and a very faint digestive uptake. The 'tumour/non-tumoral liver' ratio was high at 1, 24 and 48 h after injection (2.9+/-1.5, 4.1+/-/4.1 and 4.1+/-0.7, respectively). CONCLUSIONS: Using the method described here, 188Re-SSS lipiodol can be obtained with a very high yield and a satisfactory RCP. The biodistribution in rats with hepatoma indicates a good tumoral retention of 188Re-SSS lipiodol associated with a predominant hepatic uptake, a weak pulmonary uptake and a very faint digestive uptake. This product should be considered for intra-arterial radiation therapy in human hepatoma.


Assuntos
Carcinoma Hepatocelular/metabolismo , Óleo Iodado/administração & dosagem , Óleo Iodado/farmacocinética , Marcação por Isótopo/métodos , Neoplasias Hepáticas/metabolismo , Compostos Organometálicos/administração & dosagem , Compostos Organometálicos/farmacocinética , Animais , Combinação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Feminino , Injeções Intra-Arteriais , Taxa de Depuração Metabólica , Especificidade de Órgãos , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacocinética , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual , Contagem Corporal Total
18.
Nucl Med Commun ; 25(3): 291-7, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15094449

RESUMO

BACKGROUND: We develop a method for the radiolabelling of Lipiodol with Tc, using a lipophilic complex, [99mTc-(S2CPh)(S3Ph)2], dissolved in Lipiodol (99mTc-SSS Lipiodol). RESULTS: The labelling yield is high (96 +/- 0.8%), and the radiochemical purity satisfactory (92 +/- 2.6%). This labelling is reproducible and stable for up to 24 h in vitro. Studies carried out after injection into the hepatic artery of the healthy pig show that the biodistribution of 99mTc-SSS Lipiodol is comparable with that observed for 188Re Lipiodol. MATERIALS AND METHODS: The 99mTc-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with 99mTc, in cold lipiodol. The radiochemical purity (RCP) of the labelling was checked immediately and at 24 h. The 99mTc-SSS lipiodol was injected into the hepatic artery of four healthy pigs for an ex-vivo biodistribution study. An autoradiographic study was performed in two cases. CONCLUSIONS: Apart from the specific interest of a Lipiodol-bearing technetiated agent for carrying out dosimetric studies, the labelling of Lipiodol with 99mTc is a preliminary step towards the use of radiolabelling with the 188Re analogue.


Assuntos
Artéria Hepática/metabolismo , Óleo Iodado/química , Óleo Iodado/farmacocinética , Marcação por Isótopo/métodos , Tecnécio/química , Tecnécio/farmacocinética , Animais , Estudos de Viabilidade , Artéria Hepática/efeitos dos fármacos , Inativação Metabólica , Injeções Intra-Arteriais , Especificidade de Órgãos , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacocinética , Suínos , Distribuição Tecidual
19.
PLoS One ; 9(8): e105355, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25122508

RESUMO

The primary aim of this study was to characterize oculomotor performances in elderly depressed patients. The second aim was to investigate whether cognitive inhibition measured by the antisaccade task was associated with a psychomotor retardation or rather with a more specific cognitive-motor inhibition deficit. Twenty patients with a major depressive disorder and forty-seven healthy subjects performed two eye movement tasks. Saccadic reaction time and error rates were analyzed in the prosaccade task to obtain basic parameters of eye movements. Saccade latency, error rates and correction rates were evaluated in the antisaccade task to investigate inhibition capacities. Performances were impaired in patients, who exhibited a higher reaction time and error rates compared to controls. The higher time cost of inhibition suggested that the reaction time was not related to global psychomotor retardation alone. The higher time cost of inhibition could be explained by a specific alteration of inhibition processes evaluated by the antisaccade task. These changes were associated with the severity of depression. These findings provide a new perspective on cognitive inhibition in elderly depressed patients and could have important clinical implications for our understanding of critical behaviors involving deficits in inhibitory processes in the elderly.


Assuntos
Depressão , Movimentos Sacádicos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Desempenho Psicomotor , Tempo de Reação
20.
Nucl Med Commun ; 33(2): 205-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22124362

RESUMO

Rhenium-188 (188Re) is of widespread interest for treating various diseases because of its attractive physical and chemical properties. The routine preparation of therapeutic doses of 188Re-labelled tracers can result in significant radiation exposure to the operator. We studied the impact of automating the preparation of 188Re-Lipiodol on the radiochemist's exposure, as well as the importance of the model of syringe shielding. To monitor radiation exposure continuously readable electronic personal dosimeters were used. Thermoluminescence dosimeters were fixed to the probable most exposed fingers of the radiochemist during preparation of the radiotracer and during the syringing. Dose rates were measured using a Babyline. Automation of the synthesis reduced personal dose equivalents from 2.60±4.35 to 1.61±1.20 µSv/GBq [Hp(10)] and from 38.37±55.28 to 21.84±16.14 µSv/GBq [Hp(0.07)]. Dose to the extremities was also reduced (-80% for the right hand; -58% for the left one). The Lemer-Pax PSWG syringe shield led to a slightly lower dose to the hands compared with the Medisystem (1.1±0.27 vs. 1.34±0.6 mSv/GBq for the right finger). Automation of the synthesis leads to a significant decrease in radiation exposure to the operator. The Lemer-Pax PSWG syringe shield provides better hand protection than the smaller Medisystem Mediclic.


Assuntos
Partículas beta/efeitos adversos , Exposição Ocupacional/prevenção & controle , Equipamentos de Proteção , Lesões por Radiação/prevenção & controle , Proteção Radiológica/instrumentação , Antineoplásicos/síntese química , Antineoplásicos/efeitos da radiação , Automação , Carcinoma Hepatocelular/radioterapia , Óleo Etiodado/síntese química , Dedos/efeitos da radiação , Humanos , Neoplasias Hepáticas/radioterapia , Radioisótopos/efeitos da radiação , Rênio/efeitos da radiação
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