93 research outputs found

    Incidence of malignant lesions in patients with clinically benign thyroid nodules: observational and prospective study in a cohort of 50 patients followed during two years

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    INTRODUCTION: To study the frequency of malignant lesions in patients with clinically benign thyroid nodules and the value of the repetition of fine needle aspiration biopsy (FNAB). METHODS: Observational and prospective 2-year study in a cohort of 50 patients with clinically benign thyroid nodules. Patients were initially submitted to clinical examination, ultrasound (US) and FNAB1 patients, followed by a second FNAB and US. RESULTS: Palpation is not a good test for diagnosis and follow-up of thyroid nodules. On the other hand, the initial consideration that these patients should harbor benign lesions is a very useful parameter, since 47/50 patients (94%) did not present malignant lesions during the follow-up. FNAB1 and FNAB2 were concordant in 33/39 patients when FNAB1 was negative (85%); 11 patients were operated, 8 by suspicious FNAB and 3 due to nodule growth. We observed 2 patients with non-invasive papillary microcarcinoma and 1 patient with papillary carcinoma outside of the main nodules. CONCLUSION: there was concordance between initial clinical benign diagnosis, FNAB and the follow-up. In one case there was a papillary carcinoma. In addition, ultrasonography should be considered for all patients with suspected thyroid nodules. Finally, we demonstrated that a second cytology usually confirms the result of the first cytology in benign thyroid nodules.OBJETIVOS: Verificar a ocorrência de lesões malignas em pacientes com nódulos tiroidianos clinicamente benignos e o valor da repetição da citologia aspirativa da tiróide (PAAF). MÉTODOS: Estudo observacional prospectivo por 2 anos em coorte de 50 mulheres com nódulos tiroidianos clinicamente benignos, com exame clínico, ultra-sonografia (US) e PAAF inicial, seguidas por acompanhamento clínico, US e repunção dos mesmos nódulos (PAAF2). RESULTADOS: A palpação não é bom método para o seguimento dos nódulos quando comparada ao US. O quadro clínico foi parâmetro de confiança, pois 47/50 pacientes (94%) evoluíram sem malignidade durante o seguimento. PAAF1 e PAAF2 concordaram em 33/39 pacientes quando PAAF1 foi negativa (85%); 11 pacientes foram operadas, 8 por PAAF suspeita e 3 por aumento do volume nodular durante o seguimento. O anátomo-patológico (AP) foi benigno nas lesões suspeitas (8 adenomas e 3 bócios colóides). Houve 2 casos de microcarcinoma papilífero não invasivo em área distante dos nódulos e 1 caso de carcinoma papilífero não invasivo em bócio multi-nodular. CONCLUSÕES: Houve concordância entre características clínicas de benignidade com PAAF, US e acompanhamento clínico ou cirurgia; numa paciente encontramos carcinoma papilífero. O US deve ser considerado em pacientes com suspeita de nódulos de tiróide ao exame clínico; na maioria das vezes quando o resultado da PAAF1 é negativo para malignidade, o segundo exame citológico confirma o primeiro.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Otorrinolaringologia e Cirurgia de Cabeça e PescoçoUNIFESP, EPM, Depto. de MedicinaUNIFESP, EPM, Depto. de Otorrinolaringologia e Cirurgia de Cabeça e PescoçoSciEL

    Distributed cerebellar plasticity implements generalized multiple-scale memory components in real-robot sensorimotor tasks

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    The cerebellum plays a crucial role in motor learning and it acts as a predictive controller. Modeling it and embedding it into sensorimotor tasks allows us to create functional links between plasticity mechanisms, neural circuits and behavioral learning. Moreover, if applied to real-time control of a neurorobot, the cerebellar model has to deal with a real noisy and changing environment, thus showing its robustness and effectiveness in learning. A biologically inspired cerebellar model with distributed plasticity, both at cortical and nuclear sites, has been used. Two cerebellum-mediated paradigms have been designed: an associative Pavlovian task and a vestibulo-ocular reflex, with multiple sessions of acquisition and extinction and with different stimuli and perturbation patterns. The cerebellar controller succeeded to generate conditioned responses and finely tuned eye movement compensation, thus reproducing human-like behaviors. Through a productive plasticity transfer from cortical to nuclear sites, the distributed cerebellar controller showed in both tasks the capability to optimize learning on multiple time-scales, to store motor memory and to effectively adapt to dynamic ranges of stimuli.This work was supported by grants of European Union: REALNET (FP7-ICT270434) and Human Brain Project (HBP-604102)

    Adaptive Robotic Control Driven by a Versatile Spiking Cerebellar Network

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    The cerebellum is involved in a large number of different neural processes, especially in associative learning and in fine motor control. To develop a comprehensive theory of sensorimotor learning and control, it is crucial to determine the neural basis of coding and plasticity embedded into the cerebellar neural circuit and how they are translated into behavioral outcomes in learning paradigms. Learning has to be inferred from the interaction of an embodied system with its real environment, and the same cerebellar principles derived from cell physiology have to be able to drive a variety of tasks of different nature, calling for complex timing and movement patterns. We have coupled a realistic cerebellar spiking neural network (SNN) with a real robot and challenged it in multiple diverse sensorimotor tasks. Encoding and decoding strategies based on neuronal firing rates were applied. Adaptive motor control protocols with acquisition and extinction phases have been designed and tested, including an associative Pavlovian task (Eye blinking classical conditioning), a vestibulo-ocular task and a perturbed arm reaching task operating in closed-loop. The SNN processed in real-time mossy fiber inputs as arbitrary contextual signals, irrespective of whether they conveyed a tone, a vestibular stimulus or the position of a limb. A bidirectional long-term plasticity rule implemented at parallel fibers-Purkinje cell synapses modulated the output activity in the deep cerebellar nuclei. In all tasks, the neurorobot learned to adjust timing and gain of the motor responses by tuning its output discharge. It succeeded in reproducing how human biological systems acquire, extinguish and express knowledge of a noisy and changing world. By varying stimuli and perturbations patterns, real-time control robustness and generalizability were validated. The implicit spiking dynamics of the cerebellar model fulfill timing, prediction and learning functions.European Union (Human Brain Project) REALNET FP7-ICT270434 CEREBNET FP7-ITN238686 HBP-60410

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M&gt;70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0&lt;e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level
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