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Gonzalez-Montoro A, Pavón N, Barberá J, Cuarella N, González AJ, Jiménez-Serrano S, Lucero A, Moliner L, Sánchez D, Vidal K, Benlloch JM. Design and proof of concept of a double-panel TOF-PET system. EJNMMI Phys 2024; 11:73. [PMID: 39174856 PMCID: PMC11341523 DOI: 10.1186/s40658-024-00674-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 08/05/2024] [Indexed: 08/24/2024] Open
Abstract
OBJECTIVE Positron Emission Tomography (PET) is a well-known imaging technology for the diagnosis, treatment, and monitoring of several diseases. Most PET scanners use a Ring-Shaped Detector Configuration (RSDC), which helps obtain homogeneous image quality but are restricted to an invariable Field-of-View (FOV), scarce spatial resolution, and low sensitivity. Alternatively, few PET systems use Open Detector Configurations (ODC) to permit an accessible FOV adaptable to different target sizes, thus optimizing sensitivity. Yet, to compensate the lack of angular coverage in ODC-PET, developing a detector with high-timing performance is mandatory to enable Time-of-Flight (TOF) techniques during reconstruction. The main goal of this work is to provide a proof of concept PET scanner appropriate for constructing the new generation of ODC-PET suitable for biopsy guidance and clinical intervention during acquisition. The designed detector has to be compact and robust, and its requirements in terms of performance are spatial and time resolutions < 2 mm and < 200 ps, respectively. METHODS The present work includes a simulation study of an ODC-PET based on 2-panels with variable distance. The image quality (IQ) and Derenzo phantoms have been simulated and evaluated. The phantom simulations have also been performed using a ring-shaped PET for comparison purposes of the ODC approach with conventional systems. Then, an experimental evaluation of a prototype detector that has been designed following the simulation results is presented. This study focused on tuning the ASIC parameters and evaluating the scintillator surface treatment (ESR and TiO2), and configuration that yields the best Coincidence Time Resolution (CTR). Moreover, the scalability of the prototype to a module of 64 × 64mm2 and its preliminary evaluation regarding pixel identification are provided. RESULTS The simulation results reported sensitivity (%) values at the center of the FOV of 1.96, 1.63, and 1.18 for panel distances of 200, 250, and 300 mm, respectively. The IQ reconstructed image reported good uniformity (87%) and optimal CRC values, and the Derenzo phantom reconstruction suggests a system resolution of 1.6-2 mm. The experimental results demonstrate that using TiO2 coating yielded better detector performance than ESR. Acquired data was filtered by applying an energy window of ± 30% at the photopeak level. After filtering, best CTR of 230 ± 2 ps was achieved for an 8 × 8 LYSO pixel block with 2 × 2 × 12mm3 each. The detector performance remained constant after scaling-up the prototype to a module of 64 × 64mm2, and the flood map demonstrates the module's capabilities to distinguish the small pixels; thus, a spatial resolution < 2 mm (pixel size) is achieved. CONCLUSIONS The simulated results of this biplanar scanner show high performance in terms of image quality and sensitivity. These results are comparable to state-of-the-art PET technology and, demonstrate that including TOF information minimizes the image artifacts due to the lack of angular projections. The experimental results concluded that using TiO2 coating provide the best performance. The results suggest that this scanner may be suitable for organ study, breast, prostate, or cardiac applications, with good uniformity and CRC.
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Karakatsanis NA, Nehmeh MH, Conti M, Bal G, González AJ, Nehmeh SA. Physical performance of adaptive axial FOV PET scanners with a sparse detector block rings or a checkerboard configuration. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac6aa1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 04/26/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. Using Monte-Carlo simulations, we evaluated the physical performance of a hypothetical state-of-the-art clinical PET scanner with adaptive axial field-of-view (AFOV) based on the validated GATE model of the Siemens Biograph VisionTM PET/CT scanner. Approach. Vision consists of 16 compact PET rings, each consisting of 152 mini-blocks of 5 × 5 Lutetium Oxyorthosilicate crystals (3.2 × 3.2 × 20 mm3). The Vision 25.6 cm AFOV was extended by adopting (i) a sparse mini-block ring (SBR) configuration of 49.6 cm AFOV, with all mini-block rings interleaved with 16 mm axial gaps, or (ii) a sparse mini-block checkerboard (SCB) configuration of 51.2 cm AFOV, with all mini-blocks interleaved with gaps of 16 mm (transaxial) × 16 mm (axial) width in checkerboard pattern. For sparse configurations, a ‘limited’ continuous bed motion (limited-CBM) acquisition was employed to extend AFOVs by 2.9 cm. Spatial resolution, sensitivity, image quality (IQ), NECR and scatter fraction were assessed per NEMA NU2-2012. Main Results. All IQ phantom spheres were distinguishable with all configurations. SBR and SCB percent contrast recovery (% CR) and background variability (% BV) were similar (p-value > 0.05). Compared to Vision, SBR and SCB %CRs were similar (p-values > 0.05). However, SBR and SCB %BVs were deteriorated by 30% and 26% respectively (p-values < 0.05). SBR, SCB and Vision exhibited system sensitivities of 16.6, 16.8, and 15.8 kcps MBq−1, NECRs of 311 kcps @35 kBq cc−1, 266 kcps @25.8 kBq cc−1, and 260 kcps @27.8 kBq cc−1, and scatter fractions of 31.2%, 32.4%, and 32.6%, respectively. SBR and SCB exhibited a smoother sensitivity reduction and noise enhancement rate from AFOV center to its edges. SBR and SCB attained comparable spatial resolution in all directions (p-value > 0.05), yet, up to 1.5 mm worse than Vision (p-values < 0.05). Significance. The proposed sparse configurations may offer a clinically adoptable solution for cost-effective adaptive AFOV PET with either highly-sensitive or long-AFOV acquisitions.
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Ciordia M, Loureiro MD, González AJ. First Report of Neofusicoccum parvum Causing Canker on Castanea sativa in Spain. PLANT DISEASE 2022; 106:1299. [PMID: 34569830 DOI: 10.1094/pdis-06-21-1231-pdn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
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Ilisie V, Moliner L, Oliver S, Sánchez F, González AJ, Seimetz M, Rodríguez-Álvarez MJ, Benlloch JM. Author Correction: High resolution and sensitivity gamma camera with active septa. A first Monte Carlo study. Sci Rep 2020; 10:11877. [PMID: 32665621 PMCID: PMC7360618 DOI: 10.1038/s41598-020-68816-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Ilisie V, Moliner L, Oliver S, Sánchez F, González AJ, Seimetz M, Rodríguez-Álvarez MJ, Benlloch JM. High resolution and sensitivity gamma camera with active septa. A first Monte Carlo study. Sci Rep 2019; 9:18431. [PMID: 31804601 PMCID: PMC6895102 DOI: 10.1038/s41598-019-54934-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 11/18/2019] [Indexed: 12/02/2022] Open
Abstract
Gamma cameras are of great interest due to their high potential in the field of Nuclear Medicine Imaging. They allow for an early diagnosis of reduced size tumors, and also for a wide variety of preclinical studies with the aim of designing more effective treatments against cancer. In this work we propose a significantly improved multi-pinhole collimator gamma camera and perform a first Monte Carlo analysis of its characteristics. Maintaining the configuration of a multi-pinhole collimator with a high degree of overlapping (thus with a high sensitivity), we add a new element, an active septa, that besides acting as a collimator, is able to measure the impact coordinates of the incident photon. This way one is able to unambiguously identify through which pinhole any gamma ray passes before being detected. The result is a high sensitivity and resolution multi-pinhole gamma camera with an arbitrarily large field of view. As a consequence, the final reconstructed image does not suffer from the undesired artifacts or truncation associated to the multiplexing phenomenon. In this study we focus on the development of a system able to visualize in 3D tumors, nodes and metastasis in real time in the operating room with very low dose. We also briefly analyse and propose a novel design for a Single Photon Emission Computed Tomography system.
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Iborra A, González AJ, González-Montoro A, Bousse A, Visvikis D. Ensemble of neural networks for 3D position estimation in monolithic PET detectors. ACTA ACUST UNITED AC 2019; 64:195010. [DOI: 10.1088/1361-6560/ab3b86] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Benlloch JM, González AJ, Pani R, Preziosi E, Jackson C, Murphy J, Barberá J, Correcher C, Aussenhofer S, Gareis D, Visvikis D, Bert J, Langstrom B, Farde L, Toth M, Haggkvist J, Caixeta FV, Kullander K, Somlai-Schweiger I, Schwaiger M. The MINDVIEW project: First results. Eur Psychiatry 2018; 50:21-27. [PMID: 29398564 DOI: 10.1016/j.eurpsy.2018.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 01/01/2023] Open
Abstract
We present the first results of the MINDVIEW project. An innovative imaging system for the human brain examination, allowing simultaneous acquisition of PET/MRI images, has been designed and constructed. It consists of a high sensitivity and high resolution PET scanner integrated in a novel, head-dedicated, radio frequency coil for a 3T MRI scanner. Preliminary measurements from the PET scanner show sensitivity 3 times higher than state-of-the-art PET systems that will allow safe repeated studies on the same patient. The achieved spatial resolution, close to 1 mm, will enable differentiation of relevant brain structures for schizophrenia. A cost-effective and simple method of radiopharmaceutical production from 11C-carbon monoxide and a mini-clean room has been demonstrated. It has been shown that 11C-raclopride has higher binding potential in a new VAAT null mutant mouse model of schizophrenia compared to wild type control animals. A significant reduction in TSPO binding has been found in gray matter in a small sample of drug-naïve, first episode psychosis patients, suggesting a reduced number or an altered function of immune cells in brain at early stage schizophrenia.
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Fernández-Sanz AM, Rodicio MR, González AJ. Pseudomonas syringae pv. phaseolicola isolated from weeds in bean crop fields. Lett Appl Microbiol 2016; 62:344-8. [PMID: 26880144 DOI: 10.1111/lam.12556] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 02/09/2016] [Accepted: 02/10/2016] [Indexed: 11/28/2022]
Abstract
UNLABELLED Pseudomonas syringae pv. phaseolicola, the causative agent of halo blight in common bean (Phaseolus vulgaris L.), was isolated from weeds associated with bean crops in Spain. The bacterium was recovered from Fumaria sp, Mercurialis annua, Solanum nigrum and Sonchus oleraceus. Ps. s. pv. phaseolicola had previously been isolated from leguminous plants and S. nigrum, but to our knowledge, this is the first time it was recovered from the other three species. The isolates were phenotypically and genetically characterized, and they were compared with isolates recovered from common beans. Five different genotypic profiles were detected by PmeI-PFGE, two of them being of new description. Weed isolates were as pathogenic on bean plants as bean isolates, but they were not pathogenic on S. nigrum. Regarding the survival of the pathogen in weeds, Ps. s. pv. phaseolicola was isolated from So. oleraceus 11 weeks after the end of the bean crop. These results strongly support the idea of weeds as a potential source of inoculum for halo blight in bean. SIGNIFICANCE AND IMPACT OF THE STUDY It has traditionally been considered that the main source of inoculum of Pseudomonas syringae pv. phaseolicola causing halo blight disease in Phaseolus vulgaris are the bean seeds, and that the host range of the bacterium is almost restricted to leguminous plants. In this study, the bacterium was recovered from four nonleguminous weed species collected in bean fields, and its permanence in weeds for at least 11 weeks after the harvesting of the beans was demonstrated. We have also proved that the strains isolated from weeds were pathogenic on bean plants. Accordingly, the host range of Ps. s. pv. phaseolicola could be broader than previously thought and weeds appear to be acting as a reservoir of the pathogen until the next crop.
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Conde P, Iborra A, González AJ, Hernández L, Bellido P, Crespo E, Moliner L, Rigla JP, Rodríguez-Álvarez MJ, Sánchez F, Seimetz M, Soriano A, Vidal LF, Benlloch JM. Minimization of border effects in monolithic scintillators using neural networks, based on MR-compatible SiPM arrays. EJNMMI Phys 2014; 1:A19. [PMID: 26501604 PMCID: PMC4544606 DOI: 10.1186/2197-7364-1-s1-a19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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González AJ, Majewski S, Conde P, Hernández L, Sánchez F, Bellido P, Crespo E, Iborra A, Moliner L, Rigla JP, Rodríguez-Álvarez MJ, Seimetz M, Soriano A, Stolin A, Vidal LF, Benlloch JM. Progress report on the MindView brain PET detector module based on large area SiPMs arrays. EJNMMI Phys 2014; 1:A66. [PMID: 26501656 PMCID: PMC4545450 DOI: 10.1186/2197-7364-1-s1-a66] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Rodríguez-Alvarez MJ, Soriano A, Iborra A, Sánchez F, González AJ, Conde P, Hernández L, Moliner L, Orero A, Vidal LF, Benlloch JM. Expectation maximization (EM) algorithms using polar symmetries for computed tomography (CT) image reconstruction. Comput Biol Med 2013; 43:1053-61. [PMID: 23706690 DOI: 10.1016/j.compbiomed.2013.04.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/04/2013] [Accepted: 04/23/2013] [Indexed: 11/24/2022]
Abstract
We suggest a symmetric-polar pixellation scheme which makes possible a reduction of the computational cost for expectation maximization (EM) iterative algorithms. The proposed symmetric-polar pixellation allows us to deal with 3D images as a whole problem without dividing the 3D problem into 2D slices approach. Performance evaluation of each approach in terms of stability and image quality is presented. Exhaustive comparisons between all approaches were conducted in a 2D based image reconstruction model. From these 2D approaches, that showing the best performances were finally implemented and evaluated in a 3D based image reconstruction model. Comparison to 3D images reconstructed with FBP is also presented. Although the algorithm is presented in the context of computed tomography (CT) image reconstruction, it can be applied to any other tomographic technique as well, due to the fact that the only requirement is a scanning geometry involving measurements of an object under different projection angles. Real data have been acquired with a small animal (CT) scanner to verify the proposed mathematical description of the CT system.
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Chapman SE, Diener JM, Sasser TA, Correcher C, González AJ, Avermaete TV, Leevy WM. Dual tracer imaging of SPECT and PET probes in living mice using a sequential protocol. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2012; 2:405-414. [PMID: 23145357 PMCID: PMC3484419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 08/28/2012] [Indexed: 06/01/2023]
Abstract
Over the past 20 years, multimodal imaging strategies have motivated the fusion of Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) scans with an X-ray computed tomography (CT) image to provide anatomical information, as well as a framework with which molecular and functional images may be co-registered. Recently, pre-clinical nuclear imaging technology has evolved to capture multiple SPECT or multiple PET tracers to further enhance the information content gathered within an imaging experiment. However, the use of SPECT and PET probes together, in the same animal, has remained a challenge. Here we describe a straightforward method using an integrated trimodal imaging system and a sequential dosing/acquisition protocol to achieve dual tracer imaging with (99m)Tc and (18)F isotopes, along with anatomical CT, on an individual specimen. Dosing and imaging is completed so that minimal animal manipulations are required, full trimodal fusion is conserved, and tracer crosstalk including down-scatter of the PET tracer in SPECT mode is avoided. This technique will enhance the ability of preclinical researchers to detect multiple disease targets and perform functional, molecular, and anatomical imaging on individual specimens to increase the information content gathered within longitudinal in vivo studies.
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Navarro J, Carrasco J, González AJ, Suz LM. First Report of Cobweb on White Button Mushroom (Agaricus bisporus) in Spain Caused by Cladobotryum mycophilum. PLANT DISEASE 2012; 96:1067. [PMID: 30727232 DOI: 10.1094/pdis-02-12-0120-pdn] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Between 2008 and 2011, symptoms of cobweb were observed in commercial white button mushroom (Agaricus bisporus) crops in Castilla-La Mancha (Spain). Typical symptoms started as white, cobweb-like mycelial growth over the surface of the casing soils and fruiting bodies. Later, the mycelium changed to a grayish white, dense powder and the affected fruiting bodies turned pale yellow or reddish brown before rotting. Two types of cap spotting were observed, dark brown spots with a poorly defined edge and light brown spots. The first symptoms were commonly seen in the second or third break (flush) of mushrooms. Infected tissues of A. bisporus were plated onto potato dextrose agar (PDA) and a parasitic fungus was isolated. Fungal colonies consisted of abundant, cottony, aerial mycelium spreading rapidly over the PDA, and red pigment spreading into the agar. The cultures lacked a camphor odor. Conidiogenous cells were 24 to 45 μm long, 3 to 6 μm wide basally, and tapered slightly to the tip. Conidia were cylindrical to narrowly ellipsoidal, 15 to 28 × 8 to 11 μm, and zero- to three-septate. Total DNA was extracted and the internal transcribed spacer (ITS) region of rDNA amplified for one mycelial isolate using ITS1F/ITS4 primers (2,4). The amplicon was sequenced (GenBank Accession No. JQ004732). BLAST analysis showed highest similarity (99 and 100%) of the ITS sequence to four ITS sequences of Cladobotryum mycophilum (teleomorph Hypomyces odoratus) (GenBank Accession Nos. AB527074, JF505112, Y17095, and Y17096) (1,3) among other sequences of the same species. Two pathogenicity trials (A and B) were performed in mushroom-growing rooms, with 24 blocks in each assay containing pasteurized, spawned, and incubated A. bisporus substrate (10 kg, 0.15 m2). The blocks were cased with a 35-mm layer of a peat-based casing soil (5.5 liter/block). Nine days after casing, a conidial suspension (7.5 × 103 conidia/ml) of one isolate of C. mycophilum was sprayed (20 ml/block) onto the surface of the casing layer of 12 blocks at 106 conidia/m2. Twelve blocks were sprayed with sterile distilled water as a control treatment. Blocks were maintained at 17.5°C and 90% relative humidity. The first cobweb symptoms developed 25 days after inoculation, between the second and third breaks in trial A; and after 11 days, between the first and second breaks in trial B. C. mycophilum was consistently reisolated from eight inoculated blocks (67%) in trial A, and 11 inoculated blocks (92%) in trial B. The total area of the crop affected by cobweb was 30% in inoculated blocks in trial A and 45% in trial B. The noninoculated blocks remained healthy. Compared with the noninoculated control blocks, a 10.7% decrease in yield of mushrooms was observed in trial A and 9.1% in trial B. Previously, C. dendroides was the only known causal agent of cobweb in Spain. To our knowledge, this is the first report of C. mycophilum causing cobweb in white button mushroom in Spain, although the disease and causal agent were previously reported on cultivated king oyster mushroom (Pleurotus eryngii) in Spain (3). References: (3) C.-G. Back et al. J. Gen. Plant Pathol. 76:232, 2010. (1) M. Gardes and T. D. Bruns. Mol. Ecol. 2:113, 1993. (4) F. J. Gea et al. Plant Dis. 95:1030, 2011. (2) T. J. White et al. PCR Protocols. A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.
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Arrieta MI, Ramírez JM, Télez M, Flores P, Criado B, Barasoain M, Huerta I, González AJ. Analysis of the Fragile X Trinucleotide Repeat in Basques: Association of Premutation and Intermediate Sizes, Anchoring AGGs and Linked Microsatellites with Unstable Alleles. Curr Genomics 2011; 9:191-9. [PMID: 19440516 PMCID: PMC2679647 DOI: 10.2174/138920208784340722] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2008] [Revised: 03/16/2008] [Accepted: 03/24/2008] [Indexed: 12/02/2022] Open
Abstract
Fragile X Syndrome (FXS) is associated with an unstable CGG repeat sequence in the 5’ untranslated region in the first exon of the FMR1 gene which resides at chromosome position Xq27.3 and is coincident with the fragile site FRAXA. The CGG sequence is polymorphic with respect to size and purity of the repeat. Interpopulation variation in the polymorphism of the FMR1 gene and consequently, in the predisposition to FXS due to the prevalence of certain unstable alleles has been observed. Spanish Basque population is distributed among narrow valleys in northeastern Spain with little migration between them until recently. This characteristic may have had an effect on allelic frequency distributions. We had previously reported preliminary data on the existence of FMR1 allele differences between two Basque valleys (Markina and Arratia). In the present work we extended the study to Uribe, Gernika, Durango, Goierri and Larraun, another five isolated valleys enclosing the whole area within the Spanish Basque region. We analyzed the prevalence of FMR1 premutated and intermediate/grey zone alleles. With the aim to complete the previous investigation about the stability of the Fragile X CGG repeat in Basque valleys, we also analyzed the existence of potentially unstable alleles, not only in relation with size and purity of CGG repeat but also in relation with DXS548 and FRAXAC1 haplotypes implicated in repeat instability. The data show that differences in allele frequencies as well as in the distribution of the mutational pathways previously identified are present among Basques. The data also suggest that compared with the analyzed Basque valleys, Gernika had increased frequency of susceptibility to instability alleles, although the prevalence of premutation and intermediate/grey zone alleles in all the analyzed valleys was lower than that reported in Caucasian populations.
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González AJ, González-Varela G, Gea FJ. Brown Blotch Caused by Pseudomonas tolaasii on Cultivated Pleurotus eryngii in Spain. PLANT DISEASE 2009; 93:667. [PMID: 30764412 DOI: 10.1094/pdis-93-6-0667b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In 2006, symptoms of brown blotch were observed on cultivated Pleurotus eryngii (king oyster mushroom) in Castilla-La Mancha (Spain). Subsequently, between January and May of 2008, brown blotch affected 39.75% of the blocks of substrate cultivated, resulting in a considerable loss of production. Symptoms observed were principally characterized by a yellowish brown-to-orangish color, first of the cap and then of the stalk. Some samples also showed a slightly concave cap. From samples collected from four different king oyster mushroom farms, a fluorescent gram-negative bacterium was recovered on King's B medium and identified as Pseudomonas tolaasii by the LOPAT scheme and other tests (2). The bacterium isolated had the following characteristics: oxidative, positive for oxidase and arginine dihydrolase, negative for levan production, pectinolitic activity on potato slices, and tobacco hypersensitivity. Results from other tests were as follows: negative for esculin hydrolysis and positive for gelatine, casein, and Tween 80 hydrolysis; mannitol, erythritol, sorbitol, m-inositol, and adonitol were used as a sole carbon source, but not sucrose, d-tartrate, or trigonelline. The white line test was performed (4) using P. reactans LPPA 540 and the presumptive isolates of P. tolaasii were positive. The gene encoding the 16S rRNA from two isolates (LPPA532 and LPPA533) was sequenced after PCR amplification (2) and their nucleotide sequences (1,400 bp; EMBL Accession No. FM864215 for LPPA 532) proved to be identical. The amplified sequences were compared with DNA sequences available in databases (GenBank, EMBL, DDBJ, and PDB) by using BLAST. An identity of 99% was obtained with 16S rDNA of three P. tolaasii strains (GenBank Accession Nos. AF320990, AF094750, and AF255336). Four isolates were selected for pathogenicity tests. Bacterial suspensions were grown for 16 h in yeast peptone glucose broth (approximately 108 CFU/ml) and were inoculated by puncture into 10 mushroom caps using sterilized wooden toothpicks (4). Sterilized distilled water was used as a control. These were then incubated at room temperature in glass dishes. Assays were conducted twice and the results were recorded after 10 days. The symptoms that developed after infection were similar to those observed in the crop, while the control mushrooms remained symptomless. Bacteria sharing the characteristics of the inoculated isolates were recovered from symptomatic caps. P. tolaasii has been described as causing brown blotch on Pleurotus eryngii (1,3), but to our knowledge, this is the first report of P. tolaasii causing brown blotch on Pleurotus eryngii in Spain. References: (1) J. F. Bradbury. No. 891 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1987. (2) A. J. González et al. Appl. Environ. Microbiol. 69:2936, 2003. (3) A. Russo et al. Microbiol. Res. 158:265, 2003. (4) J. M. Wells et al. Phytopathology 86:1098, 1996.
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González AJ, Tello JC, Rodicio MR. Erwinia persicina Causing Chlorosis and Necrotic Spots in Leaves and Tendrils of Pisum sativum in Southeastern Spain. PLANT DISEASE 2007; 91:460. [PMID: 30781193 DOI: 10.1094/pdis-91-4-0460a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In 2003, symptoms of generalized chlorosis as well as necrosis in leaves and tendrils were observed in Pisum sativum L. cv Tirabeque grown in green fields in southeastern Spain (Granada Province), and by 2004, the disease affected approximately 12 ha. Bacteria isolated from symptomatic samples were gram negative, rod shaped, motile, oxidase negative, facultatively anaerobic, and fermentative, which coincided with the general characteristics of the family Enterobacteriaceae. The gene encoding the 16S rRNA from two isolates (LPPA 406 and LPPA 408) was sequenced after PCR amplification (1). The two sequences were identical (EMBL Accession No. AM294946 for LPPA 408) and showed 99% similarity with several strains of Erwinia persicina (including the type strain ATCC 35998, LPPA 373, LMG 11254, GS04, and LMG 2691). Additional biochemical tests were performed using E. persicina ATCC 49742 as a control. The three strains were negative for arginine dihydrolase activity, indol production, hydrolysis of casein, and hydrolysis of gelatin. In contrast, they were positive for assimilation of adonitol, l-lactate, mannitol, m-inositol, erythritol, sorbitol, sucrose, nitrate reduction, hydrolysis of aesculin, and growth in 5% NaCl at 36°C. Nevertheless, E. persicina ATTC 49742, but not the isolates from P. sativum, produced a pink pigment. The latter isolates were also tested for pathogenicity. Bacterial suspensions (108 CFU/ml) were spray inoculated on 10 pea seedlings of cv. Tirabeque. Seedlings were covered with transparent plastic bags for 2 days and held in an incubation chamber at 22°C and 80% relative humidity with a 12-h photoperiod. Assays were conducted twice. Symptoms that developed were similar to those originally observed in the field, whereas symptoms did not occur on control seedlings sprayed with sterile distilled water. Bacteria sharing the characteristics of the inoculated isolates were recovered from symptomatic plants, hence fulfilling Koch's postulates. E. persicina has been isolated previously from bean in the United States (3) and southeastern Spain (1) and from tomato, banana, and cucumber in Japan (2). To our knowledge, this is the first report of the bacterium on P. sativum. References: (1) A. J. González et al. Plant Dis. 89:109, 2005. (2) M. V. Hao et al. Int. J. Syst. Bacteriol. 40:379, 1990. (3) M. L. Schuster et al. Fitopatol. Bras. 6:345, 1990.
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González AJ, Hernández D, De Vera A, Barrios Y, Salido E, Torres A, Terrados N. ACE gene polymorphism and erythropoietin in endurance athletes at moderate altitude. Med Sci Sports Exerc 2006; 38:688-93. [PMID: 16679984 DOI: 10.1249/01.mss.0000210187.62672.b3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To determine the role of the ACE (I/D) gene polymorphism on erythropoietic response in endurance athletes after natural exposure to moderate altitude. METHODS Erythropoietic activity was measured in 63 male endurance athletes following natural exposure to moderate altitude (2200 m) during 48 h. Erythropoietin (EPO) levels and hemoglobin (Hb) concentrations were measured at baseline and 12, 24, and 48 h after reaching the set altitude. Reticulocyte counts were determined at baseline and 48 h thereafter. Subjects were grouped into two groups (responders and nonresponders) based on significant increase in EPO levels (median: > 16.5 ng x m(-1)) after 24 h at altitude. ACE gene polymorphism was ascertained by polymerase chain reaction (DD, 31 (49%); ID, 24 (38%); II, 8 (13%)). RESULTS Overall, EPO levels significantly increased at 12 (70%; P = 0.0001) and 24 h (72%; P = 0.0001) above baseline concentration following exposure to 2200 m. Thereafter, EPO concentration decreased at 48 h, but a significant increase in Hb levels (4.6 +/- 4%; P = 0.0001) and reticulocyte count (50.5 +/- 79%; P = 0.0001) was observed at the end of the experiment, suggesting negative feedback. There were no significant differences in EPO and Hb concentration profiles between subjects with DD genotype and those with other genotypes (ID/II). Moreover, responders (N = 42; DD, 50%; ID/II, 50%) and nonresponders (N = 21; DD, 48%; ID/II, 52%) showed a similar erythropoietic profile during the experiment and the ACE gene polymorphism did not influence the time course of the erythropoietic response. CONCLUSIONS The ACE gene polymorphism does not influence erythropoietic activity in endurance athletes after short-term exposure to moderate altitude.
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González AJ, Rodicio MR. Pseudomonas viridiflava Causing Necrotic Leaf Spots and Defoliation on Hebe spp. in Northern Spain. PLANT DISEASE 2006; 90:830. [PMID: 30781259 DOI: 10.1094/pd-90-0830a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Hebe spp. is gaining interest as an ornamental crop in Spain. In October of 2003, plants of Hebe spp. (cv. Pink Paradise, Recurva, and Topiaria) grown in a nursery located in a northern region of Spain (Principality of Asturias) developed dark reddish spots in leaves. The spots (favored by high-humidity conditions) appeared initially in internal and lower leaves, but eventually progressed to the rest of the plant causing extensive defoliation. Samples from symptomatic leaves were processed for microbiological analysis. From the samples, Stemphylium sp. and fluorescent Pseudomonas sp., identified by conventional microbiological methods (1,3), were consistently recovered. Two isolates of the fungi and two of the bacterium (LPPA 365 and LPPA 366) were used in artificial inoculations of healthy plants (cv. New Zeeland) and all were performed in duplicate. A Stemphylium sp. was inoculated by irrigation of four seedlings with a suspension obtained by homogenization of the mycelium collected from two plates of potato dextrose agar in 100 ml of sterile distilled water. An equal number of seedlings were sprayed with a bacterial suspension (108 CFU/ml) in yeast extract peptone glucose broth. The same methods were used to inoculate all four combinations of fungi and bacteria. The seedlings were maintained at 22°C during 1 month with a 16/8-h photo-period, but in inoculations with bacteria they were initially kept under transparent plastic bags for 48 h to facilitate entry. Seedlings treated with sterile distilled water were included as controls. Although a powdery film of sooty mold was observed in some of the leaves irrigated with one of the two Stemphylium sp. strains, rusty lesions and defoliation did not occur on plants inoculated with the fungal isolates alone. In contrast, symptoms comparable with those observed in the field developed in plants inoculated with the bacteria, either alone or together with the fungus. Reisolation of fluorescent Pseudomonas sp. from symptomatic leaves taken from inoculated plants confirmed pathogenicity on Hebe spp. The pathogenic isolates were tentatively identified as atypical Pseudomonas viridiflava on the basis of biochemical tests (2,3), and their identity was then confirmed by sequencing of the gene encoding the 16S rRNA (3; GenBank Accession Nos. AM182933 and AM182934 for LPPA 365 and 366, respectively). To our knowledge, this is the first report of P. viridiflava as the cause of necrotic leaf spots and defoliation in Hebe spp. References: (1) H. L. Barnett and B. B. Hunter. Illustrated Genera of Imperfect Fungi. 3rd ed. Burgess Publishing Co, Minneapolis, MN, 1972. (2) A. J. González et al. Appl. Environ. Microbiol. 69:2936, 2003. (3) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470. 1966.
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González AJ, Tello JC, Rodicio MR. Bacterial Wilt of Beans (Phaseolus vulgaris) Caused by Curtobacterium flaccumfaciens in Southeastern Spain. PLANT DISEASE 2005; 89:1361. [PMID: 30791325 DOI: 10.1094/pd-89-1361c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Symptoms of bacterial wilt were observed on common beans (cv. Donna) in southeastern Spain. From samples collected in four different fields (coast of Granada), a bacterium was isolated with the following characteristics: gram positive, aerobic rods with yellow colonies, strictly oxidative, oxidase negative, galactose, sucrose, erythritol, mannitol, sorbitol and m-inositol were not used as a sole carbon source, and hydrolysis of casein was positive. These results coincide with what is expected for Curtobacterium flaccumfaciens pv flaccumfaciens (3). One isolate from each field was selected for pathogenicity tests using two different methods. Bacterial suspensions (approximately 108 CFU/ml) were spray inoculated on bean seedlings of cv. Andecha (10 plants with three true leaves for each isolate). Beans were covered with transparent plastic bags for 2 days and held at 25°C and 80% relative humidity with a 12-h photoperiod. In addition, 10 healthy seeds of cv. Andecha were soaked in bacterial suspensions (approximately 108 CFU/ml) for 1 h and incubated at 25°C (2). Seedlings sprayed with distilled sterile water and seeds soaked in water served as controls. With both methods of inoculation, assays were conducted twice. Results were recorded after 3 weeks. Symptoms that developed on plants after infection with the four isolates were similar to those observed in the field. They included golden yellow necrotic leaf lesions and wilting. Wilting was more pronounced in the field and when inoculation was performed by spraying seedlings rather than by soaking seeds. Control plants did not develop symptoms and grew bigger than the inoculated plants. Two pathogenic isolates were identified through sequencing of the 16S rRNA gene. The genes were amplified by polymerase chain reaction (1) and their nucleotide sequences (1,418 bp) proved to be identical (Accession No. AJ879110). Comparison of these sequences with databases showed that they were also identical to those of C. flaccumfaciens strains LMG 3645 and P 259/26 (Accession Nos. AJ312209 and AJ310414) and Curtobacterium sp. strains 2384 and 3426 (Accession Nos. AY688359 and AY688360). In Spain, the bean pathogen C. flaccumfaciens was first isolated from seeds during 2001 (4). However, to our knowledge, this is the first report of damage caused by this bacterium in the field. Bacterial wilt has been recorded, but often not substantiated, in several countries from North and South America, Africa, Asia, Oceania, and Europe. References: (1) U. Edwards et al. Nucleic Acid Res. 17:7843, 1989. (2) T. F. Hsieh et al. Plant Dis. 86:1275. 2002. (3) K. Komagata and K.-I. Suzuki. Pages 1313-1317 in: Bergey's Manual of Systematic Bacteriology. Vol. 2. Williams and Wilkins, Baltimore, MD, 1986. (4) J. L. Palomo et al. Page 154 in: XI Congreso de la Sociedad Española de Fitopatología, Almería, 2002.
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González AJ, Tello JC, Cara MD. First Report of Erwinia persicina from Phaseolus vulgaris in Spain. PLANT DISEASE 2005; 89:109. [PMID: 30795305 DOI: 10.1094/pd-89-0109c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A previously unreported leaf spot disease of common bean, which caused losses as much as 50% of the crops, was observed in southeastern Spain (Almería, Granada, and Málaga provinces) in November 2003. In 2004, samples of cv. Donna with chlorotic and necrotic leaf spots were collected from Granada and processed for microbiological analysis. Bacteria isolated from the symptomatic leaves were determined to be fermentative on the basis of the ability to metabolize glucose in aerobic and anaerobic conditions. Three isolates were selected for pathogenicity tests. Bacterial suspensions (108 CFU/ml) were spray inoculated on bean seedlings (3 true leaves) of cv. Andecha. Beans were covered with transparent plastic bags for 2 days and held in an incubation chamber at 22°C and 80% relative humidity with a 12-h photoperiod. Assays were repeated at least twice. Symptoms that developed on plants inoculated with the three isolates were similar to those originally observed, while symptoms did not occur on control plants (inoculated with distilled water). The pathogenic isolates were identified by sequencing of the 16S rDNA after amplification (2). The amplified sequences were compared to available DNA sequences in databases by using BLAST (1); 99% homology with 16S rDNA of Erwinia persicina was shown. Microbiological characteristics (gram staining, motility, morphology, and results of biochemical tests) were in agreement with the molecular identification of the isolates. E. persicina has been isolated from bean in the United States (4) and described on tomato, banana, and cucumber in Japan (3). To our knowledge, this is the first report of E. persicina from common bean in Spain and in Europe. References: (1) S. F. Altschul et al. J. Mol. Biol. 215:403, 1990. (2) U. Edwards et al. Nucleic Acids Res. 17:7843, 1989. (3) M. V. Hao et al. Int. J. Syst. Bacteriol. 40:379, 1990. (4) M. L. Schuster et al. Fitopatol. Bras. 6:345, 1981.
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González AJ, Tello JC, Herrero ML. First Report of Pythium tracheiphilum Causing Wilt and Leaf Blight on Lettuce (Lactuca sativa) in Spain. PLANT DISEASE 2004; 88:1382. [PMID: 30795205 DOI: 10.1094/pdis.2004.88.12.1382b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Since 2002, a disease on lettuce plants (cv. Estibaliz) was observed in the field and in greenhouses in the Principality of Asturias in northern Spain. The disease was estimated to cause losses of 20% in field-grown crops during the summer. Plants with aboveground symptoms of wilt and necrosis and darkening of vessels and necrosis in the tap root were collected. On potato dextrose agar (PDA), a fungus was recovered and identified as Pythium tracheiphilum according to the following characters: terminal or intercalary, globose or subglobose sporangia; zoospores formed in water; chlamydospores present in old cultures; smooth, globose, terminal, and intercalary oogonia; and smooth, globose oospores (2). For pathogenicity tests, two isolates were each inoculated on 9 seedlings (3 true leaves) and 9 plants (6 to 8 true leaves) of lettuce (Batavia type) grown in peat. Inoculum was prepared by suspending mycelium of the isolates collected from two PDA plates in 100 ml of distilled water with 10 ml poured around each plant. Control plants received distilled water only. Plants were maintained at 21°C and 80% relative humidity with a 12-h photoperiod. Symptoms were observed after 4 or 7 days for seedlings and plants, respectively. Within 20 days, 33% of the seedlings and plants died, and all surviving plants showed symptoms. Symptoms did not occur on the control plants. P. tracheiphilum was reisolated from inoculated plants but not from the control plants. This fungus has been described previously as a lettuce pathogen in France and Italy (1) but to our knowledge, this is the first report of P. tracheiphilum infecting lettuce in Spain. Reference: (1) C. M. Messiaen et al. Enfermedades de las hortalizas, Mundi-prensa, Madrid. 1995. (2) A. J. van der Plaats-Niterink. Stud Mycol. 21:1, 1981.
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González AJ, Ávila M. Disease of Floral Buds of Kiwifruit in Spain Caused by Pseudomonas syringae. PLANT DISEASE 2001; 85:1287. [PMID: 30831800 DOI: 10.1094/pdis.2001.85.12.1287b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In 1999 and 2000, decay of floral buds of Actinidia deliciosa was observed in plantations in the Principality of Asturias, Spain. Bud decay led to a decrease (up to 40%) in the production of kiwifruit. Floral buds with symptoms of browning and necrosis were collected from different areas (Villaviciosa, Grado, and Pravia) and processed for microbiological analysis. A fluorescent bacterium was recovered on King's B medium and identified as Pseudomonas syringae by the LOPAT scheme and Hugh-Leifson reaction (2). Other biochemical features included esculin and gelatin hydrolysis and acid production from mannitol, erythritol, sorbitol, and m-inositol, which are features associated with P. syringae (2). Three isolates from different samples were selected to test pathogenicity using Koch's postulates. Overnight broth cultures of each isolate (109 CFU/ml) were used to infect A. deliciosa in the trials by the following procedures: (i) atomization on branches and buds; (ii) bud injection (1 ml in each bud); and (iii) bud cutting with a scalpel dipped in the suspension. Branches and buds inoculated with sterile water were used as controls. The inoculated parts were enclosed in plastic bags for 48 h. Assays were repeated at least twice. Disease symptoms appeared 2 days later, initially as dark brown spots that developed into an extensive bud rot in all inoculated cases, while no symptoms occurred in controls. P. syringae was successfully recovered from infected samples but not from control samples. The data support the pathogenicity of P. syringae on A. deliciosa. Although P. syringae was previously reported in Italy as the causal agent of disease on floral buds of A. deliciosa (1), to our knowledge, this is the first report of infection of kiwifruit by this pathogen in Spain. References: (1) G. M. Balestra and L. Varvaro. J. Phytopathol. 145:375, 1997. (2) MAPA, Manual de laboratorio, MAPA, Madrid, Spain, 1991.
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González AJ, Landeras E, Mendoza MC. Pathovars of Pseudomonas syringae causing bacterial brown spot and halo blight in phaseolus vulgaris L. are distinguishable by ribotyping. Appl Environ Microbiol 2000; 66:850-4. [PMID: 10653764 PMCID: PMC91909 DOI: 10.1128/aem.66.2.850-854.2000] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/1999] [Accepted: 11/19/1999] [Indexed: 11/20/2022] Open
Abstract
Ribotyping was evaluated as a method to differentiate between Pseudomonas syringae pv. phaseolicola and pv. syringae strains causing bacterial brown spot and halo blight diseases in Phaseolus vulgaris L. Ribotyping, with restriction enzymes BglI and SalI and using the Escherichia coli rrnB operon as the probe, differentiated 11 and 14 ribotypes, respectively, and a combination of data from both procedures yielded 19 combined ribotypes. Cluster analysis of the combined ribotypes differentiated the pathovars phaseolicola and syringae, as well as different clonal lineages within these pathovars. The potential of ribotyping to screen for correlations between lineages and factors such as geographical region and/or bean varieties is also reported.
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González AJ. Regulation of low-level radiation. COMPTES RENDUS DE L'ACADEMIE DES SCIENCES. SERIE III, SCIENCES DE LA VIE 1999; 322:241-3. [PMID: 10196679 DOI: 10.1016/s0764-4469(99)80050-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Conzĺez Villarón L, González AJ, Gracía-Talavera JR, De Castro Del Pozo S. [Edemic goiter in the Salamanca region. II. Study on etiological factors]. Rev Clin Esp 1975; 136:303-12. [PMID: 1129522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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