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1.
Pharmacol Res ; 202: 107130, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38447748

RESUMO

Pharmacology has broadened its scope considerably in recent decades. Initially, it was of interest to chemists, doctors and pharmacists. In recent years, however, it has been incorporated into the teaching of biologists, molecular biologists, biotechnologists, chemical engineers and many health professionals, among others. Traditional teaching methods, such as lectures or laboratory work, have been superseded by the use of new pedagogical approaches to enable a better conceptualization and understanding of the discipline. In this article, we present several new methods that have been used in Spanish universities. Firstly, we describe a teaching network that has allowed the sharing of pedagogical innovations in Spanish universities. A European experience to improve prescribing safety is described in detail. The use of popular films and medical TV series in biomedical students shows how these audiovisual resources can be helpful in teaching pharmacology. The use of virtual worlds is detailed to introduce this new approach to teaching. The increasingly important area of the social aspects of pharmacology is also considered in two sections, one devoted to social pharmacology and the other to the use of learning based on social services to improve understanding of this important area. Finally, the use of Objective Structured Clinical Evaluation in pharmacology allows to know how this approach can help to better evaluate clinical pharmacology students. In conclusion, this article allows to know new pedagogical methods resources used in some Spanish universities that may help to improve the teaching of pharmacology.


Assuntos
Farmacologia Clínica , Farmacologia , Humanos , Aprendizagem , Farmacologia Clínica/educação , Pessoal de Saúde , Farmacologia/educação
2.
Free Radic Biol Med ; 137: 116-130, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31035004

RESUMO

Fingolimod is one of the few oral drugs available for the treatment of multiple sclerosis (MS), a chronic, inflammatory, demyelinating and neurodegenerative disease. The mechanism of action proposed for this drug is based in the phosphorylation of the molecule to produce its active metabolite fingolimod phosphate (FP) which, in turns, through its interaction with S1P receptors, triggers the functional sequestration of T lymphocytes in lymphoid nodes. On the other hand, part if not most of the damage produced in MS and other neurological disorders seem to be mediated by reactive oxygen species (ROS), and mitochondria is one of the main sources of ROS. In the present work, we have evaluated the anti-oxidant profile of FP in a model of mitochondrial oxidative damage induced by menadione (Vitk3) on neuronal cultures. We provide evidence that incubation of neuronal cells with FP alleviates the Vitk3-induced toxicity, due to a decrease in mitochondrial ROS production. It also decreases regulated cell death triggered by imbalance in oxidative stress (restore values of advanced oxidation protein products and total thiol levels). Also restores mitochondrial function (cytochrome c oxidase activity, mitochondrial membrane potential and oxygen consumption rate) and morphology. Furthermore, increases the expression and activity of protective factors (increases Nrf2, HO1 and Trx2 expression and GST and NQO1 activity), being some of these effects modulated by its interaction with the S1P receptor. FP seems to increase mitochondrial stability and restore mitochondrial dynamics under conditions of oxidative stress, making this drug a potential candidate for the treatment of neurodegenerative diseases other than MS.


Assuntos
Antioxidantes/farmacologia , Neurônios Dopaminérgicos/metabolismo , Cloridrato de Fingolimode/farmacologia , Mitocôndrias/metabolismo , Esclerose Múltipla/tratamento farmacológico , Receptores de Esfingosina-1-Fosfato/metabolismo , Animais , Morte Celular , Linhagem Celular , Neurônios Dopaminérgicos/patologia , Cloridrato de Fingolimode/química , Cloridrato de Fingolimode/uso terapêutico , Humanos , Lisofosfolipídeos/metabolismo , Potencial da Membrana Mitocondrial , Camundongos , Mimetismo Molecular , Neuroproteção , Estresse Oxidativo/efeitos dos fármacos , Consumo de Oxigênio , Fosfatos/química , Espécies Reativas de Oxigênio/metabolismo , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Vitamina K 3/toxicidade
3.
Int J Obes (Lond) ; 42(1): 65-71, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28925408

RESUMO

BACKGROUND AND OBJECTIVE: The sequence of prenatal growth restraint and postnatal catch-up growth may lead to hepato-visceral adiposity, insulin resistance and low-grade inflammation before the onset of puberty. In prepubertal children born appropriate for gestational age (AGA) or small for gestational age (SGA), we assessed potential relationships between the aforementioned sequence and liver volume. SUBJECTS/METHODS: The study population consisted of 86 children (41 AGA and 45 SGA with catch-up growth; age (mean±s.e.m.), 8.5±0.1 years), recruited into two prospective longitudinal studies. Anthropometry, endocrine-metabolic variables and inflammatory and hepatic markers were assessed, along with liver volume, hepatic adiposity and abdominal fat partitioning (by magnetic resonance imaging). RESULTS: AGA and SGA children differed in hepato-visceral adiposity, but had similar liver volumes. Boys had larger livers than girls, and higher sex hormone binding globulin and inflammation markers. Liver volume correlated with height Z-score, body mass index Z-score, HOMA-IR (homeostasis model assessment-insulin resistance) and with subcutaneous and visceral fat, but not with birth weight Z-score or with hepatic adiposity. Height, visceral fat, gender and HOMA-IR were major determinants of liver volume, together explaining 61% of its variance. CONCLUSIONS: The trajectory from prenatal restraint, via postnatal catch-up, to hepato-visceral adiposity and insulin resistance does not appear to be detectably influenced by prepubertal alterations of liver volume. Further follow-up will disclose the potential role of liver volume in the pubertal segment of this trajectory, and whether the augmented fat content and visceral adiposity in SGA subjects is followed by the development of metabolic syndrome and hepatic dysfunction in adulthood.


Assuntos
Fígado Gorduroso/patologia , Recém-Nascido Pequeno para a Idade Gestacional/fisiologia , Gordura Intra-Abdominal/patologia , Fígado/patologia , Obesidade Infantil/epidemiologia , Criança , Feminino , Gráficos de Crescimento , Humanos , Recém-Nascido , Estudos Longitudinais , Masculino , Análise Multivariada , Sobrepeso/epidemiologia , Sobrepeso/patologia , Obesidade Infantil/patologia , Estudos Prospectivos , Fatores de Risco
4.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28869177

RESUMO

OBJECTIVE: Standardised uptake value (SUV) and volumetric parameters such as metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from 18F-FDG PET/CT are useful criteria for disease prognosis in pre-operative and post-treatment epithelial ovarian cancer (EOC). Ki67 is another prognostic biomarker in EOC, associated with tumour aggressiveness. The aim of this study is to evaluate the association between 18F-FDG PET/CT measurements and Ki67 in pre-treatment EOC to determine if PET/CT parameters could non-invasively predict tumour aggressiveness. MATERIAL AND METHODS: A pre-treatment PET/CT was performed on 18 patients with suspected or newly diagnosed EOC. Maximum SUV (SUVmax), mean SUV (SUVmean), whole-body MTV (wbMTV), and whole-body TLG (wbTLG) with a threshold of 30% and 40% of the SUVmax were obtained. Furthermore, Ki67 index (mean and hotspot) was estimated in tumour tissue specimens. Immunohistochemical findings were correlated with PET parameters. RESULTS: The mean age was 57.0 years old (standard deviation 13.6 years). A moderate correlation was observed between mean Ki67 index and SUVmax (r=0.392), SUVmean 30% (r=0.437), and SUVmean 40% (r=0.443), and also between hotspot Ki67 index and SUVmax (r=0.360), SUVmean 30% (r=0.362) and SUVmean 40% (r=0.319). There was a weaker correlation, which was inversely negative, between mean and hotspot Ki67 and volumetric PET parameters. However, no statistical significant differences were found for any correlations. CONCLUSIONS: SUVmax and SUVmean were moderately correlated with Ki67 index, whereas volumetric PET parameters overall, showed a weaker correlation. Thus, SUVmax and SUVmean could be used to assess tumour aggressiveness in pre-treatment EOC.


Assuntos
Antígenos de Neoplasias/análise , Carcinoma/diagnóstico por imagem , Radioisótopos de Flúor/farmacocinética , Fluordesoxiglucose F18/farmacocinética , Antígeno Ki-67/análise , Neoplasias Epiteliais e Glandulares/diagnóstico por imagem , Neoplasias Ovarianas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos/farmacocinética , Adulto , Idoso , Carcinoma/metabolismo , Carcinoma Epitelial do Ovário , Simulação por Computador , Feminino , Glicólise , Humanos , Interpretação de Imagem Assistida por Computador , Técnicas Imunoenzimáticas , Pessoa de Meia-Idade , Neoplasias Epiteliais e Glandulares/metabolismo , Neoplasias Ovarianas/metabolismo , Estudos Prospectivos , Distribuição Tecidual , Carga Tumoral , Adulto Jovem
5.
Redox Biol ; 13: 69-81, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28575743

RESUMO

Insulin-like growth factor-II (IGF-II) is a naturally occurring hormone that exerts neurotrophic and neuroprotective properties in a wide range of neurodegenerative diseases and ageing. Accumulating evidence suggests that the effects of IGF-II in the brain may be explained by its binding to the specific transmembrane receptor, IGFII/M6P receptor (IGF-IIR). However, relatively little is known regarding the role of IGF-II through IGF-IIR in neuroprotection. Here, using adult cortical neuronal cultures, we investigated whether IGF-II exhibits long-term antioxidant effects and neuroprotection at the synaptic level after oxidative damage induced by high and transient levels of corticosterone (CORT). Furthermore, the involvement of the IGF-IIR was also studied to elucidate its role in the neuroprotective actions of IGF-II. We found that neurons treated with IGF-II after CORT incubation showed reduced oxidative stress damage and recovered antioxidant status (normalized total antioxidant status, lipid hydroperoxides and NAD(P) H:quinone oxidoreductase activity). Similar results were obtained when mitochondria function was analysed (cytochrome c oxidase activity, mitochondrial membrane potential and subcellular mitochondrial distribution). Furthermore, neuronal impairment and degeneration were also assessed (synaptophysin and PSD-95 expression, presynaptic function and FluoroJade B® stain). IGF-II was also able to recover the long-lasting neuronal cell damage. Finally, the effects of IGF-II were not blocked by an IGF-IR antagonist, suggesting the involvement of IGF-IIR. Altogether these results suggest that, in or model, IGF-II through IGF-IIR is able to revert the oxidative damage induced by CORT. In accordance with the neuroprotective role of the IGF-II/IGF-IIR reported in our study, pharmacotherapy approaches targeting this pathway may be useful for the treatment of diseases associated with cognitive deficits (i.e., neurodegenerative disorders, depression, etc.).


Assuntos
Fator de Crescimento Insulin-Like II/farmacologia , Plasticidade Neuronal , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo , Animais , Células Cultivadas , Proteína 4 Homóloga a Disks-Large/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Glucocorticoides/toxicidade , Potencial da Membrana Mitocondrial , Neurônios/metabolismo , Neurônios/fisiologia , Ratos , Receptor IGF Tipo 2/metabolismo , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Sinapses/fisiologia , Sinaptofisina/metabolismo
6.
Mol Imaging Biol ; 19(2): 305-314, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27632424

RESUMO

PURPOSE: Human dosimetry studies play a central role in radioligand development for positron emission tomography (PET). Drawing regions of interest (ROIs) on the PET images is used to measure the dose in each organ. In the study aspects related to ROI delineation methods were evaluated for two radioligands of different biodistribution (intestinal vs urinary). PROCEDURES: PET images were simulated from a human voxel-based phantom. Several ROI delineation methods were tested: antero-posterior projections (AP), 3D sub-samples of the organs (S), and a 3D volume covering the whole-organ (W). Inter- and intra-operator variability ROI drawing was evaluated by using human data. RESULTS: The effective dose estimates using S and W methods were comparable to the true values. AP methods overestimated (49 %) the dose for the radioligand with intestinal biodistribution. Moreover, the AP method showed the highest inter-operator variability: 11 ± 1 %. CONCLUSIONS: The sub-sampled organ method showed the best balance between quantitative accuracy and inter- and intra-operator variability.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Tomografia por Emissão de Pósitrons , Radiometria , Simulação por Computador , Humanos , Variações Dependentes do Observador , Distribuição Tecidual
7.
Neuropharmacology ; 110(Pt A): 480-492, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27452720

RESUMO

Endogenous interferon beta (IFNß) is an important cytokine involved in several chronic inflammatory diseases, such as Multiple Sclerosis (MS). In spite of the numerous therapeutic approaches available for MS patients, the administration of recombinant IFNß continues being one of the first line treatment to these patients. The soluble form of IFNß receptor (sIFNAR2) could act as critical regulator of the endogenous and the systemically administered IFNß, but whether it functions as an agonist or antagonist of its ligand is not completely elucidated. Morover, the possible role of sIFNAR2 in autoimmune diseases like MS is still unknown and so far overlooked. Here we evaluated the efficacy of the combined therapy of IFNß and our recombinant protein analogous to human sIFNAR2 as a treatment in a chronic mice model of MS (CP-EAE). We also tested the effect of the sIFNAR2 administered as a monotherapy over these EAE-animals. The results showed that our recombinant sIFNAR2 protein potentiates the immunomodulatory effects of exogenous IFNß in CP-EAE by increasing the reduction of the induced inflammation and the tissue damage. Furthermore, we demonstrate for the first time that sIFNAR2 shows intrinsic properties by modulating the CP-EAE progression and the neuroinflammation processes related to this disease. Another intrinsic activity showed by sIFNAR2 is the inhibition of the T cells proliferation, which increase its potential as therapeutic molecule.


Assuntos
Encefalomielite Autoimune Experimental/tratamento farmacológico , Imunossupressores/administração & dosagem , Receptor de Interferon alfa e beta/administração & dosagem , Proteínas Recombinantes/administração & dosagem , Animais , Proliferação de Células/efeitos dos fármacos , Quimioterapia Combinada , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/fisiopatologia , Escherichia coli , Feminino , Humanos , Interferon beta/administração & dosagem , Interferon beta/metabolismo , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Microglia/patologia , Microglia/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Neurônios/fisiologia , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/patologia , Oligodendroglia/fisiologia , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Baço/efeitos dos fármacos , Baço/fisiopatologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/fisiologia
8.
Rev Esp Med Nucl Imagen Mol ; 35(2): 88-95, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26541072

RESUMO

OBJECTIVE: Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from (18)F-FDG PET/CT are emerging prognostic biomarkers in various solid neoplasms. These volumetric parameters and the SUVmax have shown to be useful criteria for disease prognostication in preoperative and post-treatment epithelial ovarian cancer (EOC) patients. The purpose of this study was to evaluate the utility of (18)F-FDG PET/CT measurements to predict survival in patients with recurrent EOC. MATERIAL AND METHODS: Twenty-six patients with EOC who underwent a total of 31 (18)F-FDG PET/CT studies for suspected recurrence were retrospectively included. SUVmax and volumetric parameters whole-body MTV (wbMTV) and whole-body TLG (wbTLG) with a threshold of 40% and 50% of the SUVmax were obtained. Correlation between PET parameters and progression-free survival (PFS) and the survival analysis of prognostic factors were calculated. RESULTS: Serous cancer was the most common histological subtype (76.9%). The median PFS was 12.5 months (range 10.7-20.6 months). Volumetric parameters showed moderate inverse correlation with PFS but there was no significant correlation in the case of SUVmax. The correlation was stronger for first recurrences. By Kaplan-Meier analysis and log-rank test, wbMTV 40%, wbMTV 50% and wbTLG 50% correlated with PFS. However, SUVmax and wbTLG 40% were not statistically significant predictors for PFS. CONCLUSION: Volumetric parameters wbMTV and wbTLG 50% measured by (18)F-FDG PET/CT appear to be useful prognostic predictors of outcome and may provide valuable information to individualize treatment strategies in patients with recurrent EOC.


Assuntos
Recidiva Local de Neoplasia/diagnóstico por imagem , Neoplasias Ovarianas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Feminino , Humanos , Imagem Multimodal , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Tomografia por Emissão de Pósitrons , Prognóstico , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Carga Tumoral
9.
Phys Med Biol ; 60(15): 5925-38, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-26184983

RESUMO

The aim of this work was to evaluate the influence of anatomical variability between subjects and of the partial volume effect (PVE) on the standardized Specific Uptake Ratio (SUR) in [(123)I]FP-bib SPECT studies. To this end, magnetic resonance (MR) images of 23 subjects with differences in the striatal volume of up to 44% were segmented and used to generate a database of 138 Monte Carlo simulated SPECT studies. Data included normal uptakes and pathological cases. Studies were reconstructed by filtered back projection (FBP) and the ordered-subset expectation-maximization algorithm. Quantification was carried out by applying a reference method based on regions of interest (ROIs) derived from the MR images and ROIs derived from the Automated Anatomical Labelling map. Our results showed that, regardless of anatomical variability, the relationship between calculated and true SUR values for caudate and putamen could be described by a multiple linear model which took into account the spill-over phenomenon caused by PVE (R² ≥ 0.963 for caudate and ≥0.980 for putamen) and also by a simple linear model (R(2) ≥ 0.952 for caudate and ≥0.973 for putamen). Calculated values were standardized by inverting both linear systems. Differences between standardized and true values showed that, although the multiple linear model was the best approach in terms of variability (X² ≥ 11.79 for caudate and ≤7.36 for putamen), standardization based on a simple linear model was also suitable (X² ≥ 12.44 for caudate and ≤12.57 for putamen).


Assuntos
Algoritmos , Compostos Radiofarmacêuticos/farmacocinética , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Interpretação Estatística de Dados , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Humanos , Radioisótopos do Iodo/farmacocinética , Método de Monte Carlo , Neostriado/diagnóstico por imagem , Tropanos/farmacocinética
10.
Br J Anaesth ; 115(1): 15-24, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26089443

RESUMO

In major surgery, the implementation of multidisciplinary, multimodal and individualized strategies, collectively termed Patient Blood Management, aims to identify modifiable risks and optimise patients' own physiology with the ultimate goal of improving outcomes. Among the various strategies utilized in Patient Blood Management, timely detection and management of preoperative anaemia is most important, as it is in itself a risk factor for worse clinical outcome, but also one of the strongest predisposing factors for perioperative allogeneic blood transfusion, which in turn increases postoperative morbidity, mortality and costs. However, preoperative anaemia is still frequently ignored, with indiscriminate allogeneic blood transfusion used as a 'quick fix'. Consistent with reported evidence from other medical specialties, this imprudent practice continues to be endorsed by non-evidence based misconceptions, which constitute serious barriers for a wider implementation of preoperative haemoglobin optimisation. We have reviewed a number of these misconceptions, which we unanimously consider should be promptly abandoned by health care providers and replaced by evidence-based strategies such as detection, diagnosis and proper treatment of preoperative anaemia. We believe that this approach to preoperative anaemia management may be a viable, cost-effective strategy that is beneficial both for patients, with improved clinical outcomes, and for health systems, with more efficient use of finite health care resources.


Assuntos
Anemia/diagnóstico , Anemia/terapia , Hemoglobinas/análise , Cuidados Pré-Operatórios , Procedimentos Cirúrgicos Operatórios , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Transfusão de Sangue/estatística & dados numéricos , Feminino , Humanos , Masculino , Fatores de Risco
11.
J Forensic Leg Med ; 32: 21-4, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25882144

RESUMO

Water skiing, boat racing, skin and scuba diving, as well as pleasure boat cruising are becoming increasingly popular hobbies. As a result, the incidence of injuries secondary to motor propellers is becoming more frequent. Injuries by propellers, amputation, death by drowning, and bleeding are rare reported events in forensic literature. The most common circumstances surrounding boat-propeller-related injuries are concerned with getting into or out of the boat, personal watercraft use or water skiing, and falling or being thrown from the boat. A case of a scuba diver's death that occurred during an illegal scuba fishing trip around a desalination plant is presented. A complete autopsy and histological study of all organs and surfaces of dismembered cadaveric sections, performed in order to determine the phases of death, are reported. An underwater scene investigation was conducted by an engineering team studying the mouth of the pump and the dynamic characteristic of rotating propeller blades.


Assuntos
Amputação Traumática/etiologia , Morte , Mergulho , Medicina Legal , Purificação da Água , Humanos , Masculino , Pessoa de Meia-Idade , Ferimentos e Lesões
12.
Phys Med Biol ; 60(1): 151-62, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25479341

RESUMO

In this work a comparison between experimental and simulated data using GATE and PeneloPET Monte Carlo simulation packages is presented. All simulated setups, as well as the experimental measurements, followed exactly the guidelines of the NEMA NU 4-2008 standards using the microPET R4 scanner. The comparison was focused on spatial resolution, sensitivity, scatter fraction and counting rates performance. Both GATE and PeneloPET showed reasonable agreement for the spatial resolution when compared to experimental measurements, although they lead to slight underestimations for the points close to the edge. High accuracy was obtained between experiments and simulations of the system's sensitivity and scatter fraction for an energy window of 350-650 keV, as well as for the counting rate simulations. The latter was the most complicated test to perform since each code demands different specifications for the characterization of the system's dead time. Although simulated and experimental results were in excellent agreement for both simulation codes, PeneloPET demanded more information about the behavior of the real data acquisition system. To our knowledge, this constitutes the first validation of these Monte Carlo codes for the full NEMA NU 4-2008 standards for small animal PET imaging systems.


Assuntos
Simulação por Computador , Processamento de Imagem Assistida por Computador/métodos , Método de Monte Carlo , Imagens de Fantasmas , Tomografia por Emissão de Pósitrons/instrumentação , Tomografia por Emissão de Pósitrons/normas , Compostos Radiofarmacêuticos , Animais , Camundongos , Software
13.
Phys Med Biol ; 59(24): 7573-85, 2014 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-25415206

RESUMO

It is well-known that in pinhole SPECT (single-photon-emission computed tomography), iterative reconstruction methods including accurate estimations of the system response matrix can lead to submillimeter spatial resolution. There are two different methods for obtaining the system response matrix: those that model the system analytically using an approach including an experimental characterization of the detector response, and those that make use of Monte Carlo simulations. Methods based on analytical approaches are faster and handle the statistical noise better than those based on Monte Carlo simulations, but they require tedious experimental measurements of the detector response. One suggested approach for avoiding an experimental characterization, circumventing the problem of statistical noise introduced by Monte Carlo simulations, is to perform an analytical computation of the system response matrix combined with a Monte Carlo characterization of the detector response. Our findings showed that this approach can achieve high spatial resolution similar to that obtained when the system response matrix computation includes an experimental characterization. Furthermore, we have shown that using simulated detector responses has the advantage of yielding a precise estimate of the shift between the point of entry of the photon beam into the detector and the point of interaction inside the detector. Considering this, it was possible to slightly improve the spatial resolution in the edge of the field of view.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Modelos Teóricos , Método de Monte Carlo , Imagens de Fantasmas , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Simulação por Computador , Humanos , Compostos de Organotecnécio/metabolismo , Fótons , Reprodutibilidade dos Testes
14.
Phys Med Biol ; 59(16): 4567-82, 2014 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-25069105

RESUMO

SPECT studies with (123)I-ioflupane facilitate the diagnosis of Parkinson's disease (PD). The effect on quantification of image degradations has been extensively evaluated in human studies but their impact on studies of experimental PD models is still unclear. The aim of this work was to assess the effect of compensating for the degrading phenomena on the quantification of small animal SPECT studies using (123)I-ioflupane. This assessment enabled us to evaluate the feasibility of quantitatively detecting small pathological changes using different reconstruction methods and levels of compensation for the image degrading phenomena. Monte Carlo simulated studies of a rat phantom were reconstructed and quantified. Compensations for point spread function (PSF), scattering, attenuation and partial volume effect were progressively included in the quantification protocol. A linear relationship was found between calculated and simulated specific uptake ratio (SUR) in all cases. In order to significantly distinguish disease stages, noise-reduction during the reconstruction process was the most relevant factor, followed by PSF compensation. The smallest detectable SUR interval was determined by biological variability rather than by image degradations or coregistration errors. The quantification methods that gave the best results allowed us to distinguish PD stages with SUR values that are as close as 0.5 using groups of six rats to represent each stage.


Assuntos
Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Método de Monte Carlo , Nortropanos , Tomografia Computadorizada de Emissão de Fóton Único , Algoritmos , Animais , Humanos , Ratos
15.
Rev Esp Med Nucl Imagen Mol ; 33(3): 165-74, 2014.
Artigo em Espanhol | MEDLINE | ID: mdl-24565567

RESUMO

Epilepsy is one of the most frequent chronic neurological disorders, affecting 1-2% of the population. Patients with complex partial drug resistant episodes may benefit from a surgical treatment consisting in the excision of the epileptogenic area. Localization of the epileptogenic area was classically performed with video-EEG and magnetic resonance (MR). Recently, functional neuroimaging studies of Nuclear Medicine, positron emission tomography (PET) and single photon emission tomography (SPECT) have demonstrated their utility in the localization of the epileptogenic area prior to surgery. Ictal SPECT with brain perfusion tracers show an increase in blood flow in the initial ictal focus, while PET with (18)FDG demonstrates a decrease of glucose metabolism in the interictal functional deficit zone. In this review, the basic principles and methodological characteristics of the SPECT and PET in epilepsy are described. The ictal SPECT injection mechanism, different patterns of perfusion based on the time of ictal, postictal or interictal injection are detailed and the different diagnostic sensitivities of each one of these SPECT are reviewed. Different methods of analysis of the images with substraction and fusion systems with the MR are described. Similarly, the injection methodology, quantification and evaluation of the images of the PET in epilepsy are described. Finally, the main clinical indications of SPECT and PET in temporal and extratemporal epilepsy are detailed.


Assuntos
Epilepsia/diagnóstico por imagem , Neuroimagem/métodos , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada de Emissão de Fóton Único , Fluordesoxiglucose F18 , Humanos , Compostos Radiofarmacêuticos
16.
Vox Sang ; 106(1): 83-91, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23869647

RESUMO

BACKGROUND: Postoperative blood loss may be a risk factor for allogeneic blood transfusion (ABT) in patients undergoing subcapital hip fracture (SHF) repair. We investigated the utility and costs of using a low-vacuum reinfusion drain (Bellovac ABT) within a blood management protocol for reducing ABT requirements in consecutive SHF. METHODS: The blood management protocol consisted of the application of a restrictive transfusion trigger (Hb < 8 g/dl), the peri-operative administration of IV iron sucrose (3 × 200 mg/48 h) ± recombinant erythropoietin (1 × 40 000 IU sc) and the use of Bellovac ABT (Group 2, n = 117). An immediate previous SHF series managed without Bellovac ABT served as control (Group 1, n = 138). RESULTS: Overall, 72 out of 255 (28%) received at least one ABT unit (2·1 ± 1·0 U/transfused patient) without differences between groups. However, in the subgroup of patients with admission Hb < 13 g/dl, the use of Bellovac ABT reduced postoperative ABT rates (16% vs. 46%, for groups 2 and 1, respectively; P = 0·001), although only 3 were reinfused, and was cost-saving. The use of Bellovac ABT also resulted in fewer wound bleeding complications, but there were no differences in Hb at postoperative days 7 and 30 between groups. CONCLUSIONS: In SHF patients with admission Hb < 13 g/dl and managed with peri-operative IV iron ± recombinant erythropoietin plus restrictive transfusion indication, the use of Bellovac ABT was associated with reduced ABT requirements, without increasing postoperative complications, and cost-savings.


Assuntos
Transfusão de Sangue/métodos , Fraturas do Quadril/cirurgia , Hemorragia Pós-Operatória/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Eritropoetina/administração & dosagem , Feminino , Humanos , Ferro/administração & dosagem , Masculino , Sucção , Vácuo
17.
Eur J Neurol ; 20(11): 1459-e126, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23679075

RESUMO

BACKGROUND AND PURPOSE: Patients with the non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) may develop atypical parkinsonian syndromes. However, there is no current biomarker to assess which patients are at high risk of developing parkinsonism. 123I-2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane (123I-FP-CIT)-SPECT detects striatal dopamine dysfunction in vivo. The objective of the present study was to study whether non-fluent/agrammatic patients without parkinsonism at baseline present decreased striatal 123I-FP-CIT uptake. METHODS: Visual and semi-quantitative assessments of the striatal 123I-FP-CIT uptake ratio were carried out in 15 patients with nfvPPA, eight patients with the logopenic variant of PPA (lvPPA) and 18 controls. To rule out progranulin mutations or underlying Alzheimer's disease (AD), serum progranulin levels and cerebrospinal fluid (CSF) biomarkers of AD (Aß42 , total-tau, phosphorylated-tau181 ) were determined. A second 123I-FP-CIT-SPECT analysis in the biomarker-enriched groups was also carried out. RESULTS: Patients with nfvPPA presented reduced striatal 123I-FP-CIT binding, especially in the left hemisphere (P = 0.002), compared with controls. All lvPPA patients had normal striatal 123I-FP-CIT uptake. 123I-FP-CIT striatal binding in nfvPPA patients with normal progranulin and CSF biomarker levels (nfvPPA/bio-) was also significantly reduced (P < 0.05) compared with lvPPA patients with positive AD biomarkers. Sixty-four per cent (9/14) of nfvPPA patients and 80% of nfvPPA/bio- patients (8/10) showed a diminished individual left striatal 123I-FP-CIT uptake ratio. On follow-up, seven nfvPPA/bio- patients developed parkinsonism (median 1.9 years; range 1.2-2.9), six of them with baseline reduced 123I-FP-CIT uptake. CONCLUSIONS: Reduced striatal tracer uptake in nfvPPA patients prior to clinical parkinsonism can be detected by 123I-FP-CIT-SPECT, especially in those with nfvPPA/bio-, suggesting subclinical nigrostriatal degeneration. Decreased striatal 123I-FP-CIT binding might identify PPA patients at increased risk of developing atypical parkinsonian syndromes, probably related to tau-pathology.


Assuntos
Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Neostriado/metabolismo , Doença de Parkinson/metabolismo , Afasia Primária Progressiva não Fluente/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tropanos , Idoso , Biomarcadores , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neostriado/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Afasia Primária Progressiva não Fluente/diagnóstico por imagem
18.
Rev Esp Med Nucl Imagen Mol ; 31(3): 111-6, 2012.
Artigo em Espanhol | MEDLINE | ID: mdl-22154291

RESUMO

AIM: To analyze the potential improvement of (18)F-fluorodeoxyglucose (FDG) PET/CT using additional delayed images of the liver in operated colorectal cancer. MATERIAL AND METHODS: The study prospectively included 71 patients (22 women, 49 men) with mean age of 65 ± 11 years with clinical, analytic or radiological suspicion of current disease. A whole body PET/CT scan was performed at 60 min. (standard images) and after 2 hr (delayed images) post-injection of 4.07 MBq/Kg of (18)F-FDG. Visual and quantitative SUV analysis of PET/CT findings was done. All findings were confirmed by histopathology and/or at least 6 months follow-up. RESULTS: Thirty-seven out of 71 patients were diagnosed of liver metastases (79 metastases). In 38/71 cases there was extra-hepatic disease in the form of local recurrence (10), abdominopelvic (3) or mediastinal (3) lymph nodes, bone (1) or lung metastases (16) and carcinomatosis (10). Sensitivity and specificity in the diagnosis of liver metastases in a patient-by-patient basis in standard (81% and 91%) and in delayed images (95% y 97%) was calculated. The number of lesions detected in delayed images was significantly higher (66/79) than in standard images (57/79). Sensitivity and specificity for PET/CT in the diagnosis of extra-hepatic disease was 84% and 70%, contributing to the detection of synchronous tumors in 5 patients. CONCLUSIONS: PET/CT may be useful in the diagnosis of extra-hepatic disease in suspected recurrence of colorectal cancer. Delayed images on PET/CT may increase the sensitivity to identify liver metastases.


Assuntos
Adenocarcinoma/secundário , Neoplasias Colorretais/patologia , Neoplasias Hepáticas/secundário , Fígado/diagnóstico por imagem , Metástase Linfática/diagnóstico por imagem , Imagem Multimodal/métodos , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/terapia , Idoso , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/secundário , Neoplasias Colorretais/terapia , Feminino , Radioisótopos de Flúor , Fluordesoxiglucose F18 , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Neoplasias Pélvicas/diagnóstico por imagem , Neoplasias Pélvicas/secundário , Estudos Prospectivos , Compostos Radiofarmacêuticos , Sensibilidade e Especificidade , Fatores de Tempo
19.
Nutr Hosp ; 27(6): 1817-36, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23588429

RESUMO

Perioperative anaemia, with iron deficiency being its leading cause, is a frequent condition among surgical patients, and has been linked to increased postoperative morbidity and mortality, and decreased quality of life. Postoperative anaemia is even more frequent and is mainly caused by perioperative blood loss, aggravated by inflammation-induced blunting of erythropoiesis. Allogenic transfusion is commonly used for treating acute perioperative anaemia, but it also increases the rate of morbidity and mortality in surgical and critically ill patients. Thus, overall concerns about adverse effects of both preoperative anaemia and allogeneic transfusion have prompted the review of transfusion practice and the search for safer and more biologically rational treatment options. In this paper, the role of intravenous iron therapy (mostly with iron sucrose and ferric carboxymaltose), as a safe and efficacious tool for treating anaemia and reducing transfusion requirements in surgical patients, as well as in other medical areas, has been reviewed. From the analysis of published data and despite the lack of high quality evidence in some areas, it seems fair to conclude that perioperative intravenous iron administration, with or without erythropoiesis stimulating agents, is safe, results in lower transfusion requirements and hastens recovery from postoperative anaemia. In addition, some studies have reported decreased rates of postoperative infection and mortality, and shorter length of hospital stay in surgical patients receiving intravenous iron.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Transfusão de Sangue/estatística & dados numéricos , Compostos de Ferro/uso terapêutico , Assistência Perioperatória/métodos , Transfusão de Sangue Autóloga , Humanos , Injeções Intravenosas , Compostos de Ferro/administração & dosagem , Compostos de Ferro/efeitos adversos
20.
Rev Esp Med Nucl ; 30(5): 286-91, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21640439

RESUMO

OBJECTIVE: To develop a small-animal SPECT system using a low cost commercial portable gamma camera equipped with a pinhole collimator, a continuous scintillation crystal and a position-sensitive photomultiplier tube. MATERIAL AND METHODS: The gamma camera was attached to a variable radius system, which enabled us to optimize sensitivity and resolution by adjusting the radius of rotation to the size of the object. To investigate the capability of the SPECT system for small animal imaging, the dependence of resolution and calibration parameters on radius was assessed and acquisitions of small phantoms and mice were carried out. RESULTS: Resolution values, ranging from 1.0mm for a radius of 21.4mm and 1.4mm for a radius of 37.2mm were obtained, thereby justifying the interest of a variable radius SPECT system. CONCLUSIONS: The image quality of phantoms and animals were satisfactory, thus confirming the usefulness of the system for small animal SPECT imaging.


Assuntos
Câmaras gama , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Animais , Encéfalo/diagnóstico por imagem , Calibragem , Desenho de Equipamento , Processamento de Imagem Assistida por Computador , Pulmão/diagnóstico por imagem , Camundongos , Imagens de Fantasmas , Compostos Radiofarmacêuticos , Agregado de Albumina Marcado com Tecnécio Tc 99m , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único/veterinária
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