318 research outputs found

    Contribución a la identificación de esporas del Reino Fungi en la atmósfera de La Plata, Argentina

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    Based on the aeromycological analysis of La Plata city, artificial Morphological Groups of fungal spores were defined. This study is a methodological contribution to the identification and counting of a fraction of the atmospheric micobiota. For the definition of groups, the criteria of Saccardo (1886) were taken into account and the groupings created by Díaz et al. (1998) and Aira et al. (2005) have been reformulated. Four new groups have been created and other sporal types have been incorporated to previous classifications. Each of them includes 2 to 6 spore types belonging to the Phylum Zygomycota, Basidiomycota and Ascomycota and their anamorphs, assigned to generic level. Characters that define such associations are: Absidia Group, hyaline amerospores; Cortinarius Group, pigmented amerospores; Didymella Group, hyalines or slightly colored didymospores; Didymosphaeria Group, pigmented didymospores and didymoconidia; Leptosphaeria Group, hyaline to pigmented phragmospores and Helminthosporium Group, hyaline to pigmented distoseptated phragmoconidia. The aim of this work is to give a tool to facilitate the task of data processing by providing new qualitative elements to prior classifications and contributing to the complex problem of identification of fungal spores presents in atmosphere.A partir del análisis del registro aeromicológico de la ciudad de La Plata se propone la definición de Grupos Morfológicos de esporas del Reino Fungi. Este estudio constituye un aporte metodológico a la identificación y recuento de una fracción de la micobiota atmosférica. Para la definición de los grupos, se han tenido en cuenta los criterios de Saccardo (1886) y reformulado los agrupamientos de Díaz et al. (1998) y Aira et al. (2005). Se han creando 4 nuevos grupos y se han incorporando otros tipos esporales a las clasificaciones previas. Cada grupo, incluye entre 2 y 6 tipos de esporas pertenecientes a los Phylum Zygomycota, Basidiomycota y Ascomycota y sus anamorfos, que han sido asignados a nivel genérico. Los caracteres que definen dichas asociaciones son: Grupo Absidia, amerosporas hialinas; Grupo Cortinarius, amerosporas pigmentadas amigdaliformes; Grupo Didymella, didimosporas hialinas o levemente coloreadas; Grupo Didymosphaeria, didimosporas y didimoconidios pigmentados; Grupo Lepthosphaeria, fragmosporas septadas hialinas a pigmentadas y Grupo Helminthosporium, fragmosporas distoseptadas hialinas a pigmentadas. Esta investigación aspira a proporcionar una herramienta que facilite el procesamiento de datos y aporte nuevos elementos cualitativos a las clasificaciones previas, contribuyendo en la compleja problemática de identificación de las esporas fúngicas

    Metabolic spatial connectivity in Amyotrophic Lateral Sclerosis as revealed by independent component analysis

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    Objectives. Positron emission tomography (PET) and volume of interest (VOI) analysis have recently shown in amyotrophic lateral sclerosis (ALS) an accuracy of 93% in differentiating patients from controls. The aim of this study was to disclose by spatial independent component analysis (ICA) the brain networks involved in ALS pathological processes and evaluate their discriminative value in separating patients from controls. Experimental design. Two hundred fifty-nine ALS patients and 40 age- and sex-matched control subjects underwent brain 18F-2-fluoro-2-deoxy-D-glucose PET (FDG-PET). Spatial ICA of the preprocessed FDG-PET images was performed. Intensity values were converted to z-scores and binary masks were used as data-driven VOIs. The accuracy of this classifier was tested versus a validated system processing intensity signals in 27 brain meta-VOIs. A support vector machine was independently applied to both datasets and the \u27leave-one-out\u27 technique verified the general validity of results. Principal observations: The 8 components selected as pathophysiologically meaningful discriminated patients from controls with 99.0% accuracy, the discriminating value of bilateral cerebellum/midbrain alone representing 96.3%. Among the meta-VOIs, right temporal lobe alone reached an accuracy of 93.7%. Conclusions: Spatial ICA identified in a very large cohort of ALS patients distinct spatial networks showing a high discriminatory value, improving substantially on the previously obtained accuracy. The cerebellar/midbrain component accounted for the highest accuracy in separating ALS patients from controls. Spatial ICA and multivariate analysis perform better than univariate semi-quantification methods in identifying the neurodegenerative features of ALS and pave the way for inclusion of PET in clinical trials and early diagnosis

    Time-dependent recovery of brain hypometabolism in neuro-COVID-19 patients

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    Purpose We evaluated brain metabolic dysfunctions and associations with neurological and biological parameters in acute, subacute and chronic COVID-19 phases to provide deeper insights into the pathophysiology of the disease.Methods Twenty-six patients with neurological symptoms (neuro-COVID-19) and [F-18]FDG-PET were included. Seven patients were acute (< 1 month (m) after onset), 12 subacute (4 >= 1-m, 4 >= 2-m and 4 >= 3-m) and 7 with neuro-post-COVID-19 (3 >= 5-m and 4 >= 7-9-m). One patient was evaluated longitudinally (acute and 5-m). Brain hypo- and hypermetabolism were analysed at single-subject and group levels. Correlations between severity/extent of brain hypo- and hypermetabolism and biological (oxygen saturation and C-reactive protein) and clinical variables (global cognition and Body Mass Index) were assessed.Results The "fronto-insular cortex" emerged as the hypometabolic hallmark of neuro-COVID-19. Acute patients showed the most severe hypometabolism affecting several cortical regions. Three-m and 5-m patients showed a progressive reduction of hypometabolism, with limited frontal clusters. After 7-9 months, no brain hypometabolism was detected. The patient evaluated longitudinally showed a diffuse brain hypometabolism in the acute phase, almost recovered after 5 months. Brain hypometabolism correlated with cognitive dysfunction, low blood saturation and high inflammatory status. Hypermetabolism in the brainstem, cerebellum, hippocampus and amygdala persisted over time and correlated with inflammation status.Conclusion Synergistic effects of systemic virus-mediated inflammation and transient hypoxia yield a dysfunction of the fronto-insular cortex, a signature of CNS involvement in neuro-COVID-19. This brain dysfunction is likely to be transient and almost reversible. The long-lasting brain hypermetabolism seems to reflect persistent inflammation processes

    An H-TERT Mutated Skin Metastasis as First Occurrence in a Case of Follicular Thyroid Carcinoma

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    Differentiated thyroid cancer arising from thyroid follicular epithelial cells is the most frequent endocrine malignancy, and skin metastases are very rare. We describe a case of a 70-year-old women with a history of an indeterminate thyroid nodule on cytology. A painless, erythematous skin nodule of about 7 mm diameter was removed from the scalp and diagnosed as a metastasis from thyroid cancer. After total thyroidectomy, a histological diagnosis of follicular thyroid cancer was made. Two cycles of radioactive iodine were performed. Both the follicular thyroid carcinoma and the metastasis were investigated for the presence of BRAF/RAS and TERT promoter mutations. The results showed that the cutaneous metastasis was BRAF wild-type and TERT promoter-mutated (position g.1,295,228 C>T); in contrast, the primary thyroid lesion was negative for both molecular markers

    Functional pattern of Brain FDG-PET in Amyotrophic Lateral Sclerosis

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    Objective: We investigated a large sample of patients with amyotrophic lateral sclerosis (ALS) at rest in order to assess the value of 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) PET as a biomarker to discriminate patients from controls. Methods: A total of 195 patients with ALS and 40 controls underwent brain 18F-FDG-PET, most within 5 months of diagnosis. Spinal and bulbar subgroups of ALS were also investigated. Twenty-five bilateral cortical and subcortical volumes of interest and cerebellum were taken into account, and 18F-FDG uptakes were individually normalized by whole-brain values. Group analyses investigated the ALS-related metabolic changes. Discriminant analysis investigating sensitivity and specificity was performed using the 51 volumes of interest as well as age and sex. Metabolic connectivity was explored by voxel-wise interregional correlation analysis. Results: Hypometabolismwas found in frontal, motor, and occipital cortex and hypermetabolismin midbrain, temporal pole, and hippocampus in patients with ALS compared to controls. A similar metabolic pattern was also found in the 2 subgroups. Discriminant analysis showed a sensitivity of 95% and a specificity of 83% in separating patients from controls. Connectivity analysis found a highly significant positive correlation between midbrain and white matter in corticospinal tracts in patients with ALS. Conclusions: 18F-FDG distribution changes in ALS showed a clear pattern of hypometabolism in frontal and occipital cortex and hypermetabolism in midbrain. The latter might be interpreted as the neurobiological correlate of diffuse subcortical gliosis. Discriminant analysis resulted in high sensitivity and specificity in differentiating patients with ALS from controls. Once validated by diseased-control studies, the present methodology might represent a potentially useful biomarker for ALS diagnosis. Classificaton of evidence: This study provides Class III evidence that 18F-FDG-PET accurately distinguishes patients with ALS from normal controls (sensitivity 95.4%, specificity 82.5%)

    Opportunistic skeletal muscle metrics as prognostic tools in metastatic castration-resistant prostate cancer patients candidates to receive Radium-223

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    Objective: Androgen deprivation therapy alters body composition promoting a significant loss in skeletal muscle (SM) mass through inflammation and oxidative damage. We verified whether SM anthropometric composition and metabolism are associated with unfavourable overall survival (OS) in a retrospective cohort of metastatic castration-resistant prostate cancer (mCRPC) patients submitted to 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG PET/CT) imaging before receiving Radium-223. Patients and methods: Low-dose CT were opportunistically analysed using a cross-sectional approach to calculate SM and adipose tissue areas at the third lumbar vertebra level. Moreover, a 3D computational method was used to extract psoas muscles to evaluate their volume, Hounsfield Units (HU) and FDG retention estimated by the standardized uptake value (SUV). Baseline established clinical, lab and imaging prognosticators were also recorded. Results: SM area predicted OS at univariate analysis. However, this capability was not additive to the power of mean HU and maximum SUV of psoas muscles volume. These factors were thus combined in the Attenuation Metabolic Index (AMI) whose power was tested in a novel uni- and multivariable model. While Prostate-Specific Antigen (PSA), Alkaline Phosphatase (ALP), Lactate Dehydrogenase and Hemoglobin, Metabolic Tumor Volume, Total Lesion Glycolysis and AMI were associated with long-term OS at the univariate analyses, only PSA, ALP and AMI resulted in independent prognosticator at the multivariate analysis. Conclusion: The present data suggest that assessing individual 'patients' SM metrics through an opportunistic operator-independent computational analysis of FDG PET/CT imaging provides prognostic insights in mCRPC patients candidates to receive Radium-223. Graphical abstract: [Figure not available: see fulltext.

    Diagnostic utility of FDG-PET in the differential diagnosis between different forms of primary progressive aphasia

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    PURPOSE: A joint effort of the European Association of Nuclear Medicine (EANM) and the European Academy of Neurology (EAN) aims at clinical guidance for the use of FDG-PET in neurodegenerative diseases. This paper addresses the diagnostic utility of FDG-PET over clinical/neuropsychological assessment in the differentiation of the three forms of primary progressive aphasia (PPA). METHODS: Seven panelists were appointed by the EANM and EAN and a literature search was performed by using harmonized PICO (Population, Intervention, Comparison, Outcome) question keywords. The studies were screened for eligibility, and data extracted to assess their methodological quality. Critical outcomes were accuracy indices in differentiating different PPA clinical forms. Subsequently Delphi rounds were held with the extracted data and quality assessment to reach a consensus based on both literature and expert opinion. RESULTS: Critical outcomes for this PICO were available in four of the examined papers. The level of formal evidence supporting clinical utility of FDG-PET in differentiating among PPA variants was considered as poor. However, the consensual recommendation was defined on Delphi round I, with six out of seven panelists supporting clinical use. CONCLUSIONS: Quantitative evidence demonstrating utility or lack thereof is still missing. Panelists decided consistently to provide interim support for clinical use based on the fact that a typical atrophy or metabolic pattern is needed for PPA according to the diagnostic criteria, and the synaptic failure detected by FDG-PET is an earlier phenomenon than atrophy. Also, a normal FDG-PET points to a non-neurodegenerative cause
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