9 results on '"Pizarro, J."'
Search Results
2. Automatic segmentation of ventricular volume by 3D ultrasonography in post haemorrhagic ventricular dilatation among preterm infants
- Author
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Isabel Benavente-Fernández, J. Pizarro, Simon P. Lubián López, Lionel C. Gontard, Borja Sanz-Peña, [Gontard,LC] Department of Condensed Matter Physics, University of Cádiz, Puerto Real, Spain. [Gontard,LC, Pizarro,J] Department of Computer Engineering, University of Cádiz, Puerto Real, Spain. [Sanz-Peña,B] Department of Neurosurgery, Puerta del Mar Hospital, Cádiz, Spain. [Lubián López,SP, Benavente-Fernández,I] Department of Pediatrics (Neonatology), Biomedical Research and Innovation Institute of Cádiz (INiBICA) Research Unit, Puerta del Mar Hospital, Cádiz, Spain. [Lubián López,SP, Benavente-Fernández,I] Biomedical Research and Innovation Institute of Cádiz (INiBICA) Research Unit, Puerta del Mar University, Cádiz, Spain. [Lubián López,SP, Benavente-Fernández,I] Foundation for the Development of Neonatal Neurology (Nene), Madrid, Spain. [Benavente-Fernández,I] Department of Maternal and Child Health and Radiology, School of Medicine, University of Cádiz, Cádiz, Spain., This work was supported by the 2017 (PI0052/2017) and 2019 (ITI-0019-2019) ITI-Cadiz integrated territorial initiative for biomedical research European Regional Development Fund (ERDF) 2014–2020. Andalusian Ministry of Health and Families, Spain., Física de la Materia Condensada, Ingeniería Informática, and Materno-Infantil y Radiología
- Subjects
Edad gestacional ,Convolutional neural network ,Anatomy::Body Regions::Breast [Medical Subject Headings] ,Ultrasonografía ,Organisms::Eukaryota::Animals::Chordata::Vertebrates::Mammals::Primates::Haplorhini::Catarrhini::Hominidae::Humans [Medical Subject Headings] ,Recien nacido prematuro ,Engineering ,0302 clinical medicine ,Software Design ,Image Processing, Computer-Assisted ,Medicine ,Breast ,Peso al nacer ,Ultrasonography ,Multidisciplinary ,Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Diagnostic Techniques and Procedures::Diagnostic Imaging::Imaging, Three-Dimensional [Medical Subject Headings] ,Premature infants ,Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Diagnostic Techniques and Procedures::Physical Examination::Body Constitution::Body Weights and Measures::Organ Size [Medical Subject Headings] ,Aprendizaje profundo ,Ventricular dilatation ,Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Statistics as Topic::Sensitivity and Specificity [Medical Subject Headings] ,Ultrasound ,Information Science::Information Science::Computing Methodologies::Software::Software Design [Medical Subject Headings] ,Gestational age ,Organ Size ,3d ultrasonography ,Anatomy::Cardiovascular System::Heart::Heart Ventricles [Medical Subject Headings] ,Persons::Persons::Age Groups::Infant::Infant, Newborn::Infant, Premature [Medical Subject Headings] ,Neurology ,Diseases::Pathological Conditions, Signs and Symptoms::Pathological Conditions, Anatomical::Dilatation, Pathologic [Medical Subject Headings] ,Cardiology ,Convolutional neural networks ,Infant, Premature ,Dilatation, Pathologic ,medicine.medical_specialty ,Heart Ventricles ,Science ,Red nerviosa ,Sensitivity and Specificity ,Article ,03 medical and health sciences ,Deep Learning ,Imaging, Three-Dimensional ,Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Diagnostic Techniques and Procedures::Diagnostic Imaging::Ultrasonography [Medical Subject Headings] ,Birth weight ,030225 pediatrics ,Internal medicine ,Humans ,Information Science::Information Science::Computing Methodologies::Image Processing, Computer-Assisted [Medical Subject Headings] ,business.industry ,Deep learning ,Infant, Newborn ,Stroke Volume ,Hypertrophy ,Persons::Persons::Age Groups::Infant::Infant, Newborn [Medical Subject Headings] ,Diseases::Pathological Conditions, Signs and Symptoms::Pathological Conditions, Anatomical::Hypertrophy [Medical Subject Headings] ,Phenomena and Processes::Mathematical Concepts::Neural Networks (Computer) [Medical Subject Headings] ,Diseases of the nervous system ,Automatic segmentation ,Ventricular volume ,Neural Networks, Computer ,Artificial intelligence ,Volumen sistólico ,business ,Phenomena and Processes::Circulatory and Respiratory Physiological Phenomena::Cardiovascular Physiological Phenomena::Hemodynamics::Cardiac Output::Stroke Volume [Medical Subject Headings] ,Phenomena and Processes::Physiological Phenomena::Physiological Processes::Growth and Development::Morphogenesis::Embryonic and Fetal Development::Fetal Development::Gestational Age [Medical Subject Headings] ,030217 neurology & neurosurgery ,Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Diagnostic Techniques and Procedures::Physical Examination::Body Constitution::Body Weights and Measures::Body Size::Body Weight::Birth Weight [Medical Subject Headings] - Abstract
To train, evaluate, and validate the application of a deep learning framework in three-dimensional ultrasound (3D US) for the automatic segmentation of ventricular volume in preterm infants with post haemorrhagic ventricular dilatation (PHVD). We trained a 2D convolutional neural network (CNN) for automatic segmentation ventricular volume from 3D US of preterm infants with PHVD. The method was validated with the Dice similarity coefficient (DSC) and the intra-class coefficient (ICC) compared to manual segmentation. The mean birth weight of the included patients was 1233.1 g (SD 309.4) and mean gestational age was 28.1 weeks (SD 1.6). A total of 152 serial 3D US from 10 preterm infants with PHVD were analysed. 230 ventricles were manually segmented. Of these, 108 were used for training a 2D CNN and 122 for validating the methodology for automatic segmentation. The global agreement for manual versus automated measures in the validation data (n = 122) was excellent with an ICC of 0.944 (0.874–0.971). The Dice similarity coefficient was 0.8 (± 0.01). 3D US based ventricular volume estimation through an automatic segmentation software developed through deep learning improves the accuracy and reduces the processing time needed for manual segmentation using VOCAL. 3D US should be considered a promising tool to help deepen our current understanding of the complex evolution of PHVD.
- Published
- 2021
3. New candidate blood biomarkers potentially associated with white matter hyperintensities progression
- Author
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Júlia Faura, Joan Montaner, Joan Jiménez-Balado, Iolanda Riba-Llena, Elena Palà, Jesús Pizarro, Mar Hernández-Guillamon, Anna Penalba, Pilar Delgado, Instituto de Salud Carlos III, Generalitat de Catalunya, European Commission, Red de Enfermedades Vasculares Cerebrales (España), Institut Català de la Salut, [Jiménez-Balado J, Pizarro J, Riba-Llena I, Penalba A, Faura J, Palà E, Hernández-Guillamon M] Laboratori de Recerca Neurovascular, Vall d’Hebron Institut de Recerca (VHIR), Barcelona, Spain. Universitat Autònoma de Barcelona, Bellaterra, Spain. [Montaner J] Laboratori de Recerca Neurovascular, Vall d’Hebron Institut de Recerca (VHIR), Barcelona, Spain. Universitat Autònoma de Barcelona, Bellaterra, Spain. Institute de Biomedicine of Seville, IBiS/Hospital Universitario Virgen del Rocío/CSIC/University of Seville & Department of Neurology, Hospital Universitario Virgen Macarena, Seville, Spain. [Delgado P] Laboratori de Recerca Neurovascular, Vall d’Hebron Institut de Recerca (VHIR), Barcelona, Spain. Universitat Autònoma de Barcelona, Bellaterra, Spain. Unitat de Demència, Servei de Neurologia, Vall d’Hebron Hospital Universitari, Barcelona, Spain. Universitat Autònoma de Barcelona, Bellatera, Spain, and Vall d'Hebron Barcelona Hospital Campus
- Subjects
0301 basic medicine ,Oncology ,Future studies ,factores biológicos::biomarcadores [COMPUESTOS QUÍMICOS Y DROGAS] ,0302 clinical medicine ,Otros calificadores::Otros calificadores::/metabolismo [Otros calificadores] ,Multidisciplinary ,medicine.diagnostic_test ,Matched control ,Neuro-vascular interactions ,Other subheadings::Other subheadings::/metabolism [Other subheadings] ,Nervous System::Central Nervous System::Brain::White Matter [ANATOMY] ,Middle Aged ,Proto-Oncogene Proteins c-met ,Control subjects ,Magnetic Resonance Imaging ,White Matter ,sistema nervioso::sistema nervioso central::encéfalo::sustancia blanca [ANATOMÍA] ,Matrix Metalloproteinase 9 ,Blood-Brain Barrier ,Marcadors bioquímics ,Hypertension ,Biomarker (medicine) ,Medicine ,Hipertensió ,enfermedades cardiovasculares::enfermedades vasculares::hipertensión [ENFERMEDADES] ,medicine.medical_specialty ,Science ,Cardiovascular Diseases::Vascular Diseases::Hypertension [DISEASES] ,Biological Factors::Biomarkers [CHEMICALS AND DRUGS] ,behavioral disciplines and activities ,Article ,03 medical and health sciences ,Internal medicine ,Neutral Ceramidase ,mental disorders ,medicine ,Humans ,Mielina - Metabolisme ,Aged ,business.industry ,Magnetic resonance imaging ,Hyperintensity ,030104 developmental biology ,Blood biomarkers ,business ,030217 neurology & neurosurgery ,Biomarkers ,Neuroscience - Abstract
We aimed to discover blood biomarkers associated with longitudinal changes in white matter hyperintensities (WMH). This study was divided into a discovery phase and a replication phase. Subjects in both studies were patients with hypertension, aged 50–70, who underwent two magnetic resonance imaging (MRI) sessions and blood extractions over a 4-year follow-up period. In the discovery phase, we screened 1305 proteins in 12 subjects with WMH progression and in 12 matched control subjects. We found that 41 proteins were differentially expressed: 13 were upregulated and 28 were downregulated. We subsequently selected three biomarkers for replication in baseline and follow-up samples in 80 subjects with WMH progression and in 80 control subjects. The selected protein candidates for the replication were MMP9 (matrix metalloproteinase-9), which was higher in cases, MET (hepatocyte growth factor receptor) and ASAH2 (neutral ceramidase), which were both lower in cases of WMH progression. Baseline biomarker concentrations did not predict WMH progression. In contrast, patients with WMH progression presented a steeper decline in MET over time. Furthermore, cases showed higher MMP9 and lower ASAH2 levels than controls at the follow-up. These results indicate that MMP9, MET, and ASAH2 are potentially associated with the progression of WMH, and could therefore be interesting candidates to validate in future studies., Funds were obtained from the Instituto de Salud Carlos III (Grant Numbers: PI14/01535, PI17/02222, ICI14/307, PI19/00217, CP15/00010, and JR15/00032), incorporation of scientists and technicians to research groups (PERIS, SLT006/17/00266) and the AGAUR (FI_DGR 2017, Grant Number 2017_FI_B 00064), with the support of the Secretary of Universities and Research (Department of Economy and Knowledge, Generalitat de Catalunya), and was cofinanced by the European Regional Development Fund. The neurovascular research laboratory receives funds from the Spanish research stroke network (RD/16/0019/0021).
- Published
- 2021
4. Contaminant emissions as indicators of chemical elements in the snow along a latitudinal gradient in southern Andes.
- Author
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Pizarro J, Vergara PM, Cerda S, Cordero RR, Castillo X, Rowe PM, Casassa G, Carrasco J, Damiani A, Llanillo PJ, Lambert F, Rondanelli R, Huneeus N, Fernandoy F, Alfonso J, and Neshyba S
- Abstract
The chemical composition of snow provides insights on atmospheric transport of anthropogenic contaminants at different spatial scales. In this study, we assess how human activities influence the concentration of elements in the Andean mountain snow along a latitudinal transect throughout Chile. The concentration of seven elements (Al, Cu, Fe, Li, Mg, Mn and Zn) was associated to gaseous and particulate contaminants emitted at different spatial scales. Our results indicate carbon monoxide (CO) averaged at 20 km and nitrogen oxide (NOx) at 40 km as the main indicators of the chemical elements analyzed. CO was found to be a significant predictor of most element concentrations while concentrations of Cu, Mn, Mg and Zn were positively associated to emissions of NOx. Emission of 2.5 μm and 10 μm particulate matter averaged at different spatial scales was positively associated to concentration of Li. Finally, the concentration of Zn was positively associated to volatile organic compounds (VOC) averaged at 40 km around sampling sites. The association between air contaminants and chemical composition of snow suggests that regions with intensive anthropogenic pollution face reduced quality of freshwater originated from glacier and snow melting., (© 2021. The Author(s).)
- Published
- 2021
- Full Text
- View/download PDF
5. New candidate blood biomarkers potentially associated with white matter hyperintensities progression.
- Author
-
Jiménez-Balado J, Pizarro J, Riba-Llena I, Penalba A, Faura J, Palà E, Montaner J, Hernández-Guillamon M, and Delgado P
- Subjects
- Aged, Blood-Brain Barrier metabolism, Humans, Magnetic Resonance Imaging, Matrix Metalloproteinase 9 metabolism, Middle Aged, Neutral Ceramidase genetics, Neutral Ceramidase metabolism, Proto-Oncogene Proteins c-met metabolism, Biomarkers metabolism, Hypertension metabolism, White Matter metabolism
- Abstract
We aimed to discover blood biomarkers associated with longitudinal changes in white matter hyperintensities (WMH). This study was divided into a discovery phase and a replication phase. Subjects in both studies were patients with hypertension, aged 50-70, who underwent two magnetic resonance imaging (MRI) sessions and blood extractions over a 4-year follow-up period. In the discovery phase, we screened 1305 proteins in 12 subjects with WMH progression and in 12 matched control subjects. We found that 41 proteins were differentially expressed: 13 were upregulated and 28 were downregulated. We subsequently selected three biomarkers for replication in baseline and follow-up samples in 80 subjects with WMH progression and in 80 control subjects. The selected protein candidates for the replication were MMP9 (matrix metalloproteinase-9), which was higher in cases, MET (hepatocyte growth factor receptor) and ASAH2 (neutral ceramidase), which were both lower in cases of WMH progression. Baseline biomarker concentrations did not predict WMH progression. In contrast, patients with WMH progression presented a steeper decline in MET over time. Furthermore, cases showed higher MMP9 and lower ASAH2 levels than controls at the follow-up. These results indicate that MMP9, MET, and ASAH2 are potentially associated with the progression of WMH, and could therefore be interesting candidates to validate in future studies., (© 2021. The Author(s).)
- Published
- 2021
- Full Text
- View/download PDF
6. Evaluation of Antarctic Ozone Profiles derived from OMPS-LP by using Balloon-borne Ozonesondes.
- Author
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Sepúlveda E, Cordero RR, Damiani A, Feron S, Pizarro J, Zamorano F, Kivi R, Sánchez R, Yela M, Jumelet J, Godoy A, Carrasco J, Crespo JS, Seckmeyer G, Jorquera JA, Carrera JM, Valdevenito B, Cabrera S, Redondas A, and Rowe PM
- Abstract
Predicting radiative forcing due to Antarctic stratospheric ozone recovery requires detecting changes in the ozone vertical distribution. In this endeavor, the Limb Profiler of the Ozone Mapping and Profiler Suite (OMPS-LP), aboard the Suomi NPP satellite, has played a key role providing ozone profiles over Antarctica since 2011. Here, we compare ozone profiles derived from OMPS-LP data (version 2.5 algorithm) with balloon-borne ozonesondes launched from 8 Antarctic stations over the period 2012-2020. Comparisons focus on the layer from 12.5 to 27.5 km and include ozone profiles retrieved during the Sudden Stratospheric Warming (SSW) event registered in Spring 2019. We found that, over the period December-January-February-March, the root mean square error (RMSE) tends to be larger (about 20%) in the lower stratosphere (12.5-17.5 km) and smaller (about 10%) within higher layers (17.5-27.5 km). During the ozone hole season (September-October-November), RMSE values rise up to 40% within the layer from 12.5 to 22 km. Nevertheless, relative to balloon-borne measurements, the mean bias error of OMPS-derived Antarctic ozone profiles is generally lower than 0.3 ppmv, regardless of the season.
- Published
- 2021
- Full Text
- View/download PDF
7. Automatic segmentation of ventricular volume by 3D ultrasonography in post haemorrhagic ventricular dilatation among preterm infants.
- Author
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Gontard LC, Pizarro J, Sanz-Peña B, Lubián López SP, and Benavente-Fernández I
- Subjects
- Breast abnormalities, Dilatation, Pathologic diagnostic imaging, Humans, Hypertrophy, Infant, Newborn, Neural Networks, Computer, Organ Size, Sensitivity and Specificity, Software Design, Deep Learning, Heart Ventricles diagnostic imaging, Heart Ventricles pathology, Image Processing, Computer-Assisted methods, Imaging, Three-Dimensional methods, Infant, Premature, Ultrasonography methods
- Abstract
To train, evaluate, and validate the application of a deep learning framework in three-dimensional ultrasound (3D US) for the automatic segmentation of ventricular volume in preterm infants with post haemorrhagic ventricular dilatation (PHVD). We trained a 2D convolutional neural network (CNN) for automatic segmentation ventricular volume from 3D US of preterm infants with PHVD. The method was validated with the Dice similarity coefficient (DSC) and the intra-class coefficient (ICC) compared to manual segmentation. The mean birth weight of the included patients was 1233.1 g (SD 309.4) and mean gestational age was 28.1 weeks (SD 1.6). A total of 152 serial 3D US from 10 preterm infants with PHVD were analysed. 230 ventricles were manually segmented. Of these, 108 were used for training a 2D CNN and 122 for validating the methodology for automatic segmentation. The global agreement for manual versus automated measures in the validation data (n = 122) was excellent with an ICC of 0.944 (0.874-0.971). The Dice similarity coefficient was 0.8 (± 0.01). 3D US based ventricular volume estimation through an automatic segmentation software developed through deep learning improves the accuracy and reduces the processing time needed for manual segmentation using VOCAL. 3D US should be considered a promising tool to help deepen our current understanding of the complex evolution of PHVD.
- Published
- 2021
- Full Text
- View/download PDF
8. Elemental and Mineralogical Composition of the Western Andean Snow (18°S-41°S).
- Author
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Alfonso JA, Cordero RR, Rowe PM, Neshyba S, Casassa G, Carrasco J, MacDonell S, Lambert F, Pizarro J, Fernandoy F, Feron S, Damiani A, Llanillo P, Sepulveda E, Jorquera J, Garcia B, Carrera JM, Oyola P, and Kang CM
- Abstract
The snowpack is an important source of water for many Andean communities. Because of its importance, elemental and mineralogical composition analysis of the Andean snow is a worthwhile effort. In this study, we conducted a chemical composition analysis (major and trace elements, mineralogy, and chemical enrichment) of surface snow sampled at 21 sites across a transect of about 2,500 km in the Chilean Andes (18-41°S). Our results enabled us to identify five depositional environments: (i) sites 1-3 (in the Atacama Desert, 18-26°S) with relatively high concentrations of metals, high abundance of quartz and low presence of arsenates, (ii) sites 4-8 (in northern Chile, 29-32°S) with relatively high abundance of quartz and low presence of metals and arsenates, (iii) sites 9-12 (in central Chile, 33-35°S) with anthropogenic enrichment of metals, relatively high values of quartz and low abundance of arsenates, (iv) sites 13-14 (also in central Chile, 35-37°S) with relatively high values of quartz and low presence of metals and arsenates, and v) sites 15-21 (in southern Chile, 37-41°S) with relatively high abundance of arsenates and low presence of metals and quartz. We found significant anthropogenic enrichment at sites close to Santiago (a major city of 6 million inhabitants) and in the Atacama Desert (that hosts several major copper mines).
- Published
- 2019
- Full Text
- View/download PDF
9. Black carbon and other light-absorbing impurities in snow in the Chilean Andes.
- Author
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Rowe PM, Cordero RR, Warren SG, Stewart E, Doherty SJ, Pankow A, Schrempf M, Casassa G, Carrasco J, Pizarro J, MacDonell S, Damiani A, Lambert F, Rondanelli R, Huneeus N, Fernandoy F, and Neshyba S
- Abstract
Vertical profiles of black carbon (BC) and other light-absorbing impurities were measured in seasonal snow and permanent snowfields in the Chilean Andes during Austral winters 2015 and 2016, at 22 sites between latitudes 18°S and 41°S. The samples were analyzed for spectrally-resolved visible light absorption. For surface snow, the average mass mixing ratio of BC was 15 ng/g in northern Chile (18-33°S), 28 ng/g near Santiago (a major city near latitude 33°S, where urban pollution plays a significant role), and 13 ng/g in southern Chile (33-41°S). The regional average vertically-integrated loading of BC was 207 µg/m
2 in the north, 780 µg/m2 near Santiago, and 2500 µg/m2 in the south, where the snow season was longer and the snow was deeper. For samples collected at locations where there had been no new snowfall for a week or more, the BC concentration in surface snow was high (~10-100 ng/g) and the sub-surface snow was comparatively clean, indicating the dominance of dry deposition of BC. Mean albedo reductions due to light-absorbing impurities were 0.0150, 0.0160, and 0.0077 for snow grain radii of 100 µm for northern Chile, the region near Santiago, and southern Chile; respective mean radiative forcings for the winter months were 2.8, 1.4, and 0.6 W/m2 . In northern Chile, our measurements indicate that light-absorption by impurities in snow was dominated by dust rather than BC.- Published
- 2019
- Full Text
- View/download PDF
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