http://hdl.handle.net/10171/22972 2013-05-21T23:22:11Z http://hdl.handle.net/10171/27795 Title: Radiomarcaje y estudios de biodistribución de nanopartículas poliméricas como adyuvantes para la vacunación oftálmica frente a la brucelosis Author(s) : Sanchez-Martinez, M. (María); Costa-Martins, R. (Raquel) da; Quincoces, G. (Gemma); Gamazo, C. (Carlos); Caicedo, C. (Carlos); Irache, J.M. (Juan Manuel); Peñuelas, I. (Iván) Abstract: Objetivos: Optimizar el radiomarcaje con 99mTc de nanopartículas de Gantrez® manosiladas y cargadas con el antígeno de Brucella Ovis (Man-NP-HS) y llevar a cabo estudios de biodistribución en ratón tras la administración de las nanopartículas por vía ocular. Metodología: Las Man-NP-HS se obtuvieron por el método de desplazamiento de disolvente. Se purificaron, liofilizaron y caracterizaron. A continuación, se marcaron con 74 MBq de 99mTcO4 - previamente reducido con una disolución ácida de cloruro de estaño, trabajando en ausencia de oxígeno y con un pH final de 4. El rendimiento del marcaje se evaluó mediante TLC. Los estudios de biodistribución se llevaron a cabo en ratones tras la administración oftálmica de la formulación y de un control de 99mTcO4 - libre. Para ello, se sacrificaron los animales a las 2 y a las 24 horas tras la administración ocular y se contaron los órganos en un contador gamma. Resultados: Se obtuvo un rendimiento de marcaje superior al 90%. Los estudios de biodistribución de 99mTc-Man-NP-HS permitieron detectar la actividad concentrada en mucosa nasal y ocular y tracto gastrointestinal tanto a las 2 como a las 24 horas, frente a la biodistribución de 99mTcO4 - libre que permaneció concentrado en la piel alrededor del ojo y en tracto gastrointestinal. Conclusión: Los estudios de biodistribución de 99mTc-Man-NP-HS tras administración oftálmica han permitido demostrar su biodistribución en mucosas y tracto gastrointestinal, característica indispensable como sistema de liberación de antígenos a través de mucosa ocular. Esto, junto con su elevada respuesta inmune, efectiva protección y no virulencia, convierte a estas nanopartículas en una vacuna ideal anti Brucelosis. 2012-12-31T23:00:00Z http://hdl.handle.net/10171/18837 Title: Statistical parametric maps of (18)F-FDG PET and 3-D autoradiography in the rat brain: a cross-validation study Author(s) : Prieto, E. (Elena); Collantes, M. (M.); Delgado, M. (Mercedes); Juri, C. (C.); Garcia-Garcia, L. (L.); Molinet, F. (Francisco); Fernandez-Valle, M. (M.E.); Pozo, M.A. (Miguel Ángel); Gago, B. (B.); Marti-Climent, J.M. (Josep M.); Obeso, J.A. (José A.); Peñuelas, I. (Iván) Abstract: PURPOSE: Although specific positron emission tomography (PET) scanners have been developed for small animals, spatial resolution remains one of the most critical technical limitations, particularly in the evaluation of the rodent brain. The purpose of the present study was to examine the reliability of voxel-based statistical analysis (Statistical Parametric Mapping, SPM) applied to (18)F-fluorodeoxyglucose (FDG) PET images of the rat brain, acquired on a small animal PET not specifically designed for rodents. The gold standard for the validation of the PET results was the autoradiography of the same animals acquired under the same physiological conditions, reconstructed as a 3-D volume and analysed using SPM. METHODS: Eleven rats were studied under two different conditions: conscious or under inhalatory anaesthesia during (18)F-FDG uptake. All animals were studied in vivo under both conditions in a dedicated small animal Philips MOSAIC PET scanner and magnetic resonance images were obtained for subsequent spatial processing. Then, rats were randomly assigned to a conscious or anaesthetized group for postmortem autoradiography, and slices from each animal were aligned and stacked to create a 3-D autoradiographic volume. Finally, differences in (18)F-FDG uptake between conscious and anaesthetized states were assessed from PET and autoradiography data by SPM analysis and results were compared. RESULTS: SPM results of PET and 3-D autoradiography are in good agreement and led to the detection of consistent cortical differences between the conscious and anaesthetized groups, particularly in the bilateral somatosensory cortices. However, SPM analysis of 3-D autoradiography also highlighted differences in the thalamus that were not detected with PET. CONCLUSION: This study demonstrates that any difference detected with SPM analysis of MOSAIC PET images of rat brain is detected also by the gold standard autoradiographic technique, confirming that this methodology provides reliable results, although partial volume effects might make it difficult to detect slight differences in small regions. 2010-12-31T23:00:00Z http://hdl.handle.net/10171/18137 Title: Decreased glucose-derivate uptake in primary somatosensorial cortex in the brain of female AIP mice. International Porphyrins and Porphyria Meeting ( 10-13 April 2011. Cardiff, Wales) Author(s) : Benito, M. (M.); Molinet, F. (Francisco); Rodriguez, I. (Ignacio); Delgado, M. (Mercedes); Collantes, M. (M.); Garcia-Garcia, L. (L.); Lanciego, J. (J.L.); Prieto, E. (Elena); Enriquez-de-Salamanca, R. (Rafael); Unzu, C. (Carmen); Peñuelas, I. (Iván); Prieto, J. (Jesús); Pozo, M.A. (Miguel Ángel); Desco, M. (M.); Fontanellas, A. (A.) 2011-05-23T14:04:34Z http://hdl.handle.net/10171/18025 Title: Construction of different radionuclide templates of rat brains and their use on a new statistic parametric mapping analysis protocol for PET studies. International WorkshopCNA´10: Bio-medical applications of Micro-PET (20-21 September 2010. Seville) Author(s) : Molinet, F. (Francisco); Delgado, M. (Mercedes); Collantes, M. (M.); Fernandez, M. (M.E.); Prieto, E. (Elena); Garcia-Garcia, L. (L.); Juri, C. (C.); Pozo, M.A. (Miguel Ángel); Peñuelas, I. (Iván) Abstract: This work shows the development of protocols to create new 18F‐FDG and 11C‐DTBZ (dyhidrotetrabenazine, a VMAT2 transporter ligand) templates of rat brain for spatial normalisation and definition of standardised areas in images used for setting up SPM analysis of PET data. 2011-05-19T12:49:27Z http://hdl.handle.net/10171/16834 Title: Simple automated system for simultaneous production of 11C-labeled tracers by solid supported methylation Author(s) : Quincoces, G. (Gemma); Peñuelas, I. (Iván); Valero, M. (Marta); Serra, P. (Patricia); Collantes, M. (M.); Marti-Climent, J.M. (Josep M.); Arbizu, J. (J.); Garcia-Velloso, M. (María José); Richter, J. (Julia) Abstract: We herein describe a simple setup for the automated simultaneous synthesis of l-[methyl-11C]methionine and N-[methyl-11C]choline by solid-supported methylation . The setup is extremely simple and easy to adapt to other automated systems and due to its versatility, the method can be utilized for the production of other radiopharmaceuticals requiring a simple [11C]methylation step. Furthermore, it can be used for multiple simultaneous synthesis. 2006-02-14T23:00:00Z http://hdl.handle.net/10171/16833 Title: 13N-Ammonia PET as a Measurement of Hindlimb Perfusion in a Mouse Model of Peripheral Artery Occlusive Disease Author(s) : Peñuelas, I. (Iván); Aranguren, X.L. (Xavier L.); Abizanda, G. (Gloria); Marti-Climent, J.M. (Josep M.); Uriz, M. (Maialen); Ecay, M. (M.); Collantes, M. (M.); Quincoces, G. (Gemma); Richter, J.A. (José Ángel); Prosper, F. (Felipe) Abstract: Peripheral arterial occlusive disease (PAOD) is a leading cause of mortality and morbidity in the western world. The development of noninvasive methods for assessment and comparison of the efficacy of novel therapies in animal models is of great importance. Methods: Hindlimb ischemia was induced in nude mice by ligation and excision of the left femoral artery (n = 5) or the left iliac artery (n = 10). Assessment of limb perfusion was performed by small-animal PET analysis after intravenous injection of 13N-ammonia between 24 h and 30 d after surgery using the ratio of perfusion between the left limb (ischemic) and the right limb (control). Activity concentration per area unit was calculated in regions of interest placed on 1-mm-thick images for numeric calculations, and the iliac and the femoral models were compared. In addition, histopathologic studies were performed to assess the degree of necrosis (hematoxylin–eosin) and fibrosis (sirius red). Immunohistochemistry analyses for identification of arterioles ({alpha}-smooth muscle actin) and endothelium—capillaries—(Bandeiraea simplicifolia I [BS-I] lectin) were also performed. Results: Perfusion in both hindlimbs of control animals was similar (median of the left-to-right ratio = 0.99). Twenty-four hours after ischemia, perfusion of the ischemic limb (% mean ± SD) was 33.3 ± 10.6 and 22.1 ± 9.9 in the femoral and iliac models, respectively. Spontaneous recovery of perfusion in the hindlimb that underwent surgery was significantly lower in the iliac model at day +15 (73.2 ± 15.5 vs. 51.9 ± 11.3; P < 0.01). Fibrosis increased progressively until day +30, whereas muscle necrosis was maximal at day +7 with a moderate reduction by day +30. In accordance with this positive effect, there was a statistically significant increase in the area covered with smooth muscle-coated vessels (arterioles) at day +30 in comparison with day 7 (P < 0.05). In addition, a correlation between 13N-ammonia uptake and the amount of necrosis (r = –0.73; P = 0.06) and fibrosis (r = –0.67; P = 0.05) at day +30 was found. Conclusion: 13N-Ammonia imaging allows semiquantitative evaluation of hindlimb perfusion in surgical mouse models of acute hindlimb ischemia. Although spontaneous perfusion recovery is observed in both models, the iliac model shows a substantially lower recovery and is hence better suited for assessment of new therapeutic strategies for acute hindlimb 2006-12-31T23:00:00Z http://hdl.handle.net/10171/16832 Title: 18F-FDG metabolism in a rat model of chronic infarction: a 17-sector semiquantitative analysis Author(s) : Peñuelas, I. (Iván); Abizanda, G. (Gloria); Garcia-Velloso, M. (María José); Gavira, J.J. (Juan José); Marti-Climent, J.M. (Josep M.); Ecay, M. (M.); Collantes, M. (M.); Garcia-de-Jalon, J.A. (J.A.); Garcia-Rodriguez, A. (A.); Mazo, M. (Manuel); Barba, J. (Joaquín); Richter, J.A. (José Ángel); Prosper, F. (Felipe) Abstract: Strategies to establish the functional benefit of cell therapy in cardiac regeneration and the potential mechanism are needed. Aims: Development of a semi-quantitative method for non invasive assessment of cardiac viability and function in a rat model of myocardial infarction (MI) based on the use of microPET. Animals, methods: Ten rats were subjected to myocardial imaging 2, 7, 14, 30, 60 and 90 days after left coronary artery ligation. Intravenous 18F-fluoro-2-deoxy-2-D-glucose (18F-FDG) was administered and regional 18F activity concentrations per unit area were measured in 17 regions of interest (ROIs) drawn on cardiac polar maps. By comparing the differences in 18F uptake between baseline and each of the follow up time points, parametric polar maps of statistical significance (PPMSS) were calculated. Left ventricular ejection fraction (LVEF) was blindly assessed echocardiographically. All animals were sacrificed for histopathological analysis after 90 days. Results: The diagnostic quality of 18F-FDG microPET images was excellent. PPMSS demonstrated a statistically significant decrease in 18F concentrations as early as 48 hours after MI in 4 of the 17 ROIs (segments 7, 13, 16 and 17; p <0.05) that persisted throughout the study. Semi-quantitative analysis of 18F-FDG uptake correlated with echocardiographic decrease in LVEF (p <0.001). Conclusion: The use of PPMSS based on 18F-FDG-microPET provides valuable semi-quantitative information of heart glucose metabolism allowing for non-invasive follow up thus representing a useful strategy for assessment of novel therapies in cardiac regeneration. 2006-12-31T23:00:00Z http://hdl.handle.net/10171/16831 Title: PET imaging of thymidine kinase gene expression in the liver of non-human primates following systemic delivery of an adenoviral vector Author(s) : Fontanellas, A. (A.); Hervas-Stubbs, S. (Sandra); Sampedro, A. (Ana); Collantes, M. (M.); Azpilicueta, A. (Arantza); Mauleon, I. (Itsaso); Pañeda, A. (Astrid); Quincoces, G. (Gemma); Prieto, J. (Jesús); Melero, I. (Ignacio); Peñuelas, I. (Iván) Abstract: Non-invasive in vivo imaging of transgene expression is currently providing very important means to optimize gene therapy regimes. Results in non-human primates are considered the most predictive models for the outcome in patients. In this study, we have documented that tumour and primary cell lines from human and non-human primates are comparably gene-transduced in vitro by serotype 5 adenovirus expressing HSV1-thymidine kinase. Transgene expression can be quantified in human and monkey cultured cells by positron emission tomography (PET) imaging when transduced cells are incubated with a fluoride-18 labelled penciclovir analogue. In our hands, PET images of cell cultures estimate the number of transduced cells rather than intensity of transgene expression once a threshold of TK per cell is reached. Interestingly, in vivo systemic administration of a clinical grade recombinant adenovirus expressing TK into macaques gives rise to an intense retention of the radiotracer in the liver parenchyma, providing an experimental system to visualize transgene expression that ought to be similar in human and macaques. Such imaging methodology might contribute to improve strategies based on adenoviral vectors. 2008-06-29T22:00:00Z http://hdl.handle.net/10171/16661 Title: Síntesis simplificada de 11C-(+)-α-dihidrotetrabenazina para su utilización como radioligando PET de los transportadores vesiculares de monoaminas Author(s) : Quincoces, G. (Gemma); Collantes, M. (M.); Ecay, M. (M.); Martino, E. (E.); Areses, P. (P.); Obeso, J.A. (José A.); Marti-Climent, J.M. (Josep M.); Blesa, J. (J.); Álvarez, L. (Lluis); Richter, J.A. (José Ángel); Peñuelas, I. (Iván) Abstract: La dihidrotetrabenazina (2-hidroxi-3-isobutil-9,10-dimetoxi-1,3,4,6,7-hexahidro-11bH-benzo[a]-quinolizina, DTBZ) se ha convertido en el ligando ideal de los transportadores presinápticos de monoaminas (VMAT2) debido a su elevada afinidad de unión y su lipofilicidad. Objetivo. Desarrollar un procedimiento de síntesis automático para el marcaje con carbono-11 de la DTBZ para utilizarla como marcador en el estudio in vivo mediante tomografía por emisión de positrones de pérdidas neuronales en modelos animales de enfermedad de Parkinson. Material y métodos. Se ha diseñado un nuevo método de síntesis totalmente automatizado para la obtención de 11C-(+)DTBZ. La reacción de metilación del precursor ­(+)desmetildihidrotetrabenazina­ se lleva a cabo a temperatura ambiente, a partir de la obtención de 11CH3I que utilizamos como precursor primario, en presencia de dimetilsulfóxido e hidróxido de potasio. Para los procesos de purificación se han utilizado cartuchos de extracción en fase sólida alúmina y los disolventes residuales del producto final se eliminaron mediante evaporación bajo flujo de helio. Resultados. De las 54 síntesis realizadas se han obtenido, con un tiempo de bombardeo de 5 minutos, y 6 minutos de síntesis tras la obtención de 11CH3I, unas producciones medias de 1,94 ± 0,13 GBq de 11C-(+)DTBZ, estéril, apirógeno y con una pureza radioquímica > 99 %. Conclusiones. Este nuevo procedimiento de síntesis es rápido y simple, ya que para la purificación final se han optimizado técnicas que permitieran la eliminación de los disolventes residuales basándonos en su polaridad y es aplicable a otras síntesis automáticas para la obtención de otros compuestos marcados mediante reacciones de metilación. 2007-12-31T23:00:00Z http://hdl.handle.net/10171/16660 Title: Utilización de la 11C-(+)--Dihidrotetrabenazina para la evaluación de la inervación dopaminérgica en modelos animales de la enfermedad de Parkinson Author(s) : Collantes, M. (M.); Peñuelas, I. (Iván); Alvarez-Erviti, L. (Lydia); Blesa, J. (J.); Marti-Climent, J.M. (Josep M.); Quincoces, G. (Gemma); Delgado, M. (Mercedes); Ecay, M. (M.); Martinez, A. (Alfredo); Arbizu, J. (J.); Rodriguez-Oroz, M.C. (María Cruz); Obeso, J.A. (José A.); Richter, J.A. (José Ángel) Abstract: Objetivo. Este trabajo evalúa la idoneidad del radiotrazador 11C-(+)-α -dihidrotetrabenazina (11C-(+)DTBZ) para cuantificar mediante tomografía de emisión de positrones (PET) la inervación dopaminérgica en rata y mono, especies utilizadas como modelos animales en el estudio de la enfermedad de Parkinson. Material y métodos. En ratas se estudió una población control sana (n = 10) y el efecto del neurotóxico 6-hidroxidopamina (6-OHDA), además de realizarse estudios PET con 6-[(18)F]-fluoro-L-DOPA (18F-DOPA) y de autorradiografía digital cuantitativa. El estudio en Macaca fascicularis se realizó en animales control y tratados con el tóxico 1-metil-4-fenil-1,2,3,6-tetrahidropiridina (MPTP). Resultados. En ambas especies se obtuvieron imágenes de gran calidad donde se observó una alta captación de 11C-(+) DTBZ en el estriado. La cuantificación se realizó mediante la creación de imágenes paramétricas y el cálculo del potencial de unión (BP). La medida del BP en la población control de ratas arrojó un valor de 1,10 ± 0,16 (media ± error estándar [EE]), mientras que los estriados dañados con 6-OHDA mostraron una captación disminuida en función del grado de la lesión. Las imágenes obtenidas con 18F-DOPA no fueron aptas para el análisis al no discriminar los estriados, mientras que el estudio mediante autorradiografía digital cuantitativa confirmó la elevada afinidad de la 11C-(+)DTBZ por estas estructuras. En monos, el valor final de BP fue de 1,31 y 1,06 mientras que el tratamiento con MPTP disminuyó la captación en un 40 %. Conclusiones. La calidad de las imágenes PET y la disminución de la captación en las lesiones con 6-OHDA y MPTP indican que la 11C-(+)DTBZ es un radiotrazador adecuado para el estudio de la inervación dopaminérgica en estas especies animales. 2007-12-31T23:00:00Z http://hdl.handle.net/10171/16659 Title: Transplantation of adipose derived stromal cells is associated with functional improvement in a rat model of chronic myocardial infarction Author(s) : Mazo, M. (Manuel); Planat-Benard, V. (Valérie); Abizanda, G. (Gloria); Pelacho, B. (Beatriz); Leobon, B. (Bertrand); Gavira, J.J. (Juan José); Peñuelas, I. (Iván); Cemborain, A. (A.); Penicaud, L. (Luc); Laharrague, P. (Patrick); Joffre, C. (Carine); Boisson, M. (M.); Ecay, M. (M.); Collantes, M. (M.); Barba, J. (Joaquín); Casteilla, L. (L.); Prosper, F. (Felipe) Abstract: Aims: To determine the effect of transplantation of undifferentiated and cardiac pre-differentiated adipose stem cells compared with bone marrow mononuclear cells (BM-MNC) in a chronic model of myocardial infarction. Methods: Ninety-five Sprague–Dawley rats underwent left coronary artery ligation and after 1month received by direct intramyocardial injection either adipose derived stem cells (ADSC), cardiomyogenic cells (AD-CMG) or BM-MNC from enhanced-Green Fluorescent Protein (eGFP) mice. The control group was treated with culture medium. Heart function was assessed by echocardiography and 18F-FDG microPET. Cell engraftment, differentiation, angiogenesis and fibrosis in the scar tissue were also evaluated by (immuno)histochemistry and immunofluorescence. Results: One month after cell transplantation, ADSC induced a significant improvement in heart function (LVEF 46.3±9.6% versus 27.7±8% pre-transplant) and tissue viability (64.78±7.2% versus 55.89±6.3% pre-transplant). An increase in the degree of angiogenesis and a decrease in fibrosis were also detected. Although transplantation of AD-CMG or BM-MNC also had a positive, albeit smaller, effect on angiogenesis and fibrosis in the infarcted hearts, this benefit did not translate into a significant improvement in heart function or tissue viability. Conclusion: These results indicate that transplantation of adipose derived cells in chronic infarct provides a superior benefit to cardiac pre-differentiated ADSC and BM-MNC. 2008-04-30T22:00:00Z http://hdl.handle.net/10171/13574 Title: New MRI, 18F-DOPA and 11C-(+)-alpha-dihydrotetrabenazine templates for Macaca fascicularis neuroimaging: advantages to improve PET quantification Author(s) : Collantes, M. (M.); Prieto, E. (Elena); Peñuelas, I. (Iván); Blesa, J. (J.); Juri, C. (C.); Marti-Climent, J.M. (Josep M.); Quincoces, G. (Gemma); Arbizu, J. (J.); Riverol, M. (M.); Zubieta, J.L. (José L.); Rodriguez-Oroz, M.C. (María Cruz); Luquin, M.R. (María Rosario); Richter, J.A. (José Ángel); Obeso, J.A. (José A.) Abstract: Normalization of neuroimaging studies to a stereotaxic space allows the utilization of standard volumes of interest (VOIs) and voxel-based analysis (SPM). Such spatial normalization of PET and MRI studies requires a high quality template image. The aim of this study was to create new MRI and PET templates of 18F-DOPA and 11C-(+)-α-dihydrotetrabenazine (11C-DTBZ) of the Macaca fascicularis brain, an important animal model of Parkinson's disease. MRI template was constructed as a smoothed average of the scans of 15 healthy animals, previously transformed into the space of one representative MRI. In order to create the PET templates, 18F-DOPA and 11C-DTBZ PET of the same subjects were acquired in a dedicated small animal PET scanner and transformed to the created MRI template space. To validate these templates for PET quantification, parametric values obtained with a standard VOI-map applied after spatial normalization to each template were statistically compared to results computed using individual VOIs drawn for each animal. The high correlation between both procedures validated the utilization of all the templates, improving the reproducibility of PET analysis. To prove the utility of the templates for voxel-based quantification, dopamine striatal depletion in a representative monkey treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was assessed by SPM analysis of 11C-DTBZ PET. A symmetric reduction in striatal 11C-DTBZ uptake was detected in accordance with the induced lesion. In conclusion, templates of M. fascicularis brain have been constructed and validated for reproducible and automated PET quantification. All templates are electronically available via the internet. 2009-04-22T22:00:00Z http://hdl.handle.net/10171/13519 Title: Transplantation of mesenchymal stem cells exerts a greater long-term effect than bone marrow mononuclear cells in a chronic myocardial infarction model in rat Author(s) : Mazo, M. (Manuel); Gavira, J.J. (Juan José); Abizanda, G. (Gloria); Moreno, C. (Cristina); Ecay, M. (M.); Soriano, M. (Mario); Aranda, P. (P.); Collantes, M. (M.); Alegria, E. (Eduardo); Merino, J. (Juana); Peñuelas, I. (Iván); García-Verdugo, J.M. (José Manuel); Pelacho, B. (Beatriz); Prosper, F. (Felipe) Abstract: The aim of this study is to assess the long-term effect of mesenchymal stem cells (MSC) transplantation in a rat model of chronic myocardial infarction (MI) in comparison with the effect of bone marrow mononuclear cells (BM-MNC) transplant. Five weeks after induction of MI, rats were allocated to receive intramyocardial injection of 106 GFP-expressing cells (BM-MNC or MSC) or medium as control. Heart function (echocardiography and 18F-FDG-microPET) and histological studies were performed 3 months after transplantation and cell fate was analyzed along the experiment (1 and 2 weeks and 1 and 3 months). The main findings of this study were that both BM-derived populations, BM-MNC and MSC, induced a long-lasting (3 months) improvement in LVEF (BM-MNC: 26.61 ± 2.01% to 46.61 ± 3.7%, p < 0.05; MSC: 27.5 ± 1.28% to 38.8 ± 3.2%, p < 0.05) but remarkably, only MSC improved tissue metabolism quantified by 18FFDG uptake (71.15 ± 1.27 to 76.31 ± 1.11, p < 0.01), which was thereby associated with a smaller infarct size and scar collagen content and also with a higher revascularization degree. Altogether, results show that MSC provides a long-term superior benefit than whole BM-MNC transplantation in a rat model of chronic MI. 2009-10-31T23:00:00Z http://hdl.handle.net/10171/13518 Title: Intensive pharmacological immunosuppression allows for repetitive liver gene transfer with recombinant adenovirus in nonhuman primates Author(s) : Fontanellas, A. (A.); Hervas-Stubbs, S. (Sandra); Mauleon, I. (Itsaso); Dubrot, J. (Juan); Mancheño, U. (Uxua); Collantes, M. (M.); Sampedro, A. (Ana); Unzu, C. (Carmen); Alfaro, C. (Carlos); Palazon, A. (Asís); Smerdou, C. (Cristian); Benito, A. (Alberto); Prieto, J. (Jesús); Peñuelas, I. (Iván); Melero, I. (Ignacio) Abstract: Repeated administration of gene therapies is hampered by host immunity toward vectors and transgenes. Attempts to circumvent antivector immunity include pharmacological immunosuppression or alternating different vectors and vector serotypes with the same transgene. Our studies show that B-cell depletion with anti-CD20 monoclonal antibody and concomitant T-cell inhibition with clinically available drugs permits repeated liver gene transfer to a limited number of nonhuman primates with recombinant adenovirus. Adenoviral vector–mediated transfer of the herpes simplex virus type 1 thymidine kinase (HSV1-tk) reporter gene was visualized in vivo with a semiquantitative transgene-specific positron emission tomography (PET) technique, liver immunohistochemistry, and immunoblot for the reporter transgene in needle biopsies. Neutralizing antibody and T cell–mediated responses toward the viral capsids were sequentially monitored and found to be repressed by the drug combinations tested. Repeated liver transfer of the HSV1-tk reporter gene with the same recombinant adenoviral vector was achieved in macaques undergoing a clinically feasible immunosuppressive treatment that ablated humoral and cellular immune responses. This strategy allows measurable gene retransfer to the liver as late as 15 months following the first adenoviral exposure in a macaque, which has undergone a total of four treatments with the same adenoviral vector. 2009-12-15T23:00:00Z http://hdl.handle.net/10171/13226 Title: Progression of Dopaminergic Depletion in a Model of MPTP-Induced Parkinsonism in Non-Human Primates. An 18F-DOPA and 11C-DTBZ PET study Author(s) : Blesa, J. (J.); Juri, C. (C.); Collantes, M. (M.); Peñuelas, I. (Iván); Prieto, E. (Elena); Iglesias, E. (E.); Marti-Climent, J.M. (Josep M.); Arbizu, J. (J.); Zubieta, J.L. (José L.); Rodriguez-Oroz, M.C. (María Cruz); Garcia-Garcia, D. (David); Richter, J.A. (José Ángel); Cavada, C. (C.); Obeso, J.A. (José A.) Abstract: Dopaminergic depletion in the nigrostriatal system is the neurochemical hallmark of Parkinson's disease (PD). Although numerous efforts have been made to determine the evolution of dopaminergic depletion in PD, “in vivo” data concerning the stages of this process are still scarce. We evaluated 6-[18F]-fluoro-L-DOPA (18F-DOPA) and 11C-(+)-α-dihydrotetrabenazine (11C-DTBZ) using PET in a model of chronically MPTPinduced parkinsonism in non-human primates. Methods: Sixty-seven cynomolgus monkeys (Macaca fascicularis) were included in the study. Progressive parkinsonism was induced by repeated administration of small doses of MPTP (iv) over several months. Animals were classified as controls, asymptomatic, recovered (having exhibited parkinsonian features transiently) and stable parkinsonian, according to their motor status. Analysis of striatal dopaminergic activity was conducted by regions of interest (ROI) and statistical parametric mapping (SPM) over normalized parametric images. Results: A progressive loss of striatal uptake was evident among groups for both radiotracers, which correlated significantly with the clinical motor status. Changes occurred earlier, i.e. in the less affected stages, with 11C-DTBZ. Similar results were achieved by ROI and SPM analysis. Uptake was similar with both radiotracers for the asymptomatic and recovered groups. Conclusions: Serial assessment with 18F-DOPA and 11C-DTBZ PETs provides an effective approach to evaluate evolution of dopaminergic depletion in monkeys with MPTP-induced parkinsonism. This approach could be useful to perform studies aiming to test the effect of early therapeutic intervention and putative neuroprotective treatments. 2010-03-04T23:00:00Z