451 research outputs found

    Stressed brain, diseased heart : a review on the pathophysiologic mechanisms of neurocardiology

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    Cardiovascular diseases are traditionally related to well known risk factors like dyslipidemia, smoking, diabetes and hypertension. More recently, stress, anxiety and depression have been proposed as risk factors for cardiovascular diseases including heart failure, ischemic disease, hypertension and arrhythmias. Interestingly, this association has been established largely on the basis of epidemiological data, due to insufficient knowledge on the underlying pathophysiologic mechanisms. This review will revisit evidence on the interaction between the cardiovascular and nervous systems, highlighting the perspective on how the central nervous system is involved in the pathogenesis of cardiovascular diseases. Such knowledge is likely to be of relevance for the development of better strategies to treat patients in a holistic perspective

    The relevance of the brain in the diseased heart : authors' response

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    In their comment to our recent paper entitled “Stressed Brain, Diseases Heart: A review on the pathophysiologic mechanisms of neurocardiology.” [1], Dominguez-Rodriguez and Abreu-Gonzalez [2] emphasize the relevance of circadian rhythm in cardiovascular diseases and propose the suprachiasmatic nucleus and melatonin as key mediators in its pathophysiology. We found this a very interesting observation. The incidence of acute myocardial infarction [3] and its extension [4] displays a circadian pattern usually peaking in early morning

    Rapid and predictable genome evolution across three hybrid ant populations

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    Hybridization is frequent in the wild but it is unclear when admixture events lead to predictable outcomes and if so, at what timescale. We show that selection led to correlated sorting of genetic variation rapidly after admixture in 3 hybrid Formica aquilonia × F. polyctena ant populations. Removal of ancestry from the species with the lowest effective population size happened in all populations, consistent with purging of deleterious load. This process was modulated by recombination rate variation and the density of functional sites. Moreover, haplotypes with signatures of positive selection in either species were more likely to fix in hybrids. These mechanisms led to mosaic genomes with comparable ancestry proportions. Our work demonstrates predictable evolution over short timescales after admixture in nature.info:eu-repo/semantics/publishedVersio

    Rapid and predictable genome evolution across three hybrid ant populations

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    Funding Information: This work was supported by Academy of Finland (www.aka.fi) no. 328961 and HiLIFE (www2.helsinki.fi/en/helsinki-institute-of-lifescience) grants to JK. SHM was supported by a Royal Society University Research Fellowship URF \R1\180682 (www.royalsociety.org). VCS was supported by Fundação Ciência e Tecnologia CEECINST/00032/2018/CP1523/CT0008 and UIDB/00329/2020 grants (www.fct.pt). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank G. Barroso for assistance with iSMC, the SpecIAnt group for feedback, and CSC–IT Center for Science, Finland, for computational resources. This work was performed under the Global Ant Genomics Alliance. Publisher Copyright: Copyright: © 2022 Nouhaud et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Hybridization is frequent in the wild but it is unclear when admixture events lead to predictable outcomes and if so, at what timescale. We show that selection led to correlated sorting of genetic variation rapidly after admixture in 3 hybrid Formica aquilonia × F. polyctena ant populations. Removal of ancestry from the species with the lowest effective population size happened in all populations, consistent with purging of deleterious load. This process was modulated by recombination rate variation and the density of functional sites. Moreover, haplotypes with signatures of positive selection in either species were more likely to fix in hybrids. These mechanisms led to mosaic genomes with comparable ancestry proportions. Our work demonstrates predictable evolution over short timescales after admixture in nature.Peer reviewe

    Medicina à Cabeceira do Doente & Comunicação Clínica

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    O objetivo deste livro é criar um “guião" para o estudante de medicina, para o ajudar a tornar-se proficiente na ciência e na arte da Semiologia Médica. O livro é composto por quatro capítulos. O capítulo 1, "A Arte da Entrevista Clínica” fornece ao leitor uma visão da herança da comunicação clínica e da relevância da relação médico-doente. No capítulo 2 “Exame Físico de Screening” e no capítulo 3 “Exame Físico Completo” o estudante recebe um guia prático e sistematizado para duas abordagens, distintas, mas complementares, ao exame físico: uma mais curta e mais frequentemente aplicada e outra mais clássica e detalhada. O capítulo 4 “Algoritmos de Sistematização” agrega uma abordagem decisiva ao processo mental que cada clínico utiliza no processo de decisão clínica. E, com isto, pretendemos ajudar cada estudante a transformar-se num Médico

    Central autonomic nervous system response to autonomic challenges is altered in patients with a previous episode of Takotsubo Cardiomyopathy

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    Aims: Takotsubo cardiomyopathy is an intriguing disease characterized by acute transient left ventricular dysfunction usually triggered by an episode of severe stress. The excessive levels of catecholamines and the overactivation of the sympathetic system are believed to be the main pathophysiologic mechanisms of Takotsubo cardiomyopathy, but it is unclear whether there is a structural or functional signature of the disease. In this sense, our aim was to characterize the central autonomic system response to autonomic challenges in patients with a previous episode of Takotsubo cardiomyopathy when compared with a control group of healthy volunteers. Methods and results: Functional magnetic resonance imaging (fMRI) was performed in four patients with a previous episode of Takotsubo cardiomyopathy (average age of 6712 years) and in eight healthy volunteers (average age of 66 +/- 5 years) while being submitted to different autonomic challenges (cold exposure and Valsalva manoeuvre). The fMRI analysis revealed a significant variation of the blood oxygen level dependent signal triggered by the Valsalva manoeuvre in specific areas of the brain involved in the cortical control of the autonomic system and significant differences in the pattern of activation of the insular cortex, amygdala and the right hippocampus between patients with Takotsubo cardiomyopathy and controls, even though these regions did not present significant volumetric changes. Conclusion: The central autonomic response to autonomic challenges is altered in patients with Takotsubo cardiomyopathy, thus suggesting a dysregulation of the central autonomic nervous system network. Subsequent studies are needed to unveil whether these alterations are causal or predisposing factors to Takotsubo cardiomyopathy.The work was supported by the European Commission (FP7): ‘SwitchBox’ (Contract HEALTH-F2-2010-259772) and ‘MyHealth’ project (Contract DoIT-13853), and by Fundação para a Ciência e Tecnologia (project FCT-ANR/NEU-OSD/0258/2012 Portuguese North Regional Operational Program (ON.2 – O Novo Norte)) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER). PM is supported by a ‘SwitchBox’ fellowship and RM by a FCT-ANR/NEU-OSD/0258/2012 fellowship

    Common Origins of Hippocampal Ivy and Nitric Oxide Synthase Expressing Neurogliaform Cells

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    GABAergic interneurons critically regulate cortical computation through exquisite spatio-temporal control over excitatory networks. Precision of this inhibitory control requires a remarkable diversity within interneuron populations that is largely specified during embryogenesis. Although nNOS+ interneurons constitute the largest hippocampal interneuron cohort their origin and specification remain unknown. Thus, as neurogliaform (NGC) and Ivy cells (IvC) represent the main nNOS+ interneurons we investigated their developmental origins. Although considered distinct interneuron subtypes NGCs and IvCs exhibited similar neurochemical and electrophysiological signatures including NPY expression and late-spiking. Moreover, lineage analyses, including loss-of-function experiments and inducible fate-mapping, indicated that nNOS+ IvCs and NGCs are both derived from medial ganglionic eminence (MGE) progenitors under control of the transcription factor Nkx2-1. Surprisingly, a subset of NGCs lacking nNOS arises from caudal ganglionic eminence (CGE) progenitors. Thus, while nNOS+ NGCs and IvCs arise from MGE progenitors, a CGE origin distinguishes a discrete population of nNOS-NGCs

    Methodology for phytoplankton taxonomic group identification towards the development of a lab-on-a-chip

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    This paper presents the absorbance and fluorescence optical properties of various phytoplankton species, looking to achieve an accurate method to detect and identify a number of phytoplankton taxonomic groups. The methodology to select the excitation and detection wavelengths that results in superior identification of phytoplankton is reported. The macroscopic analyses and the implemented methodology are the base for designing a lab-on-a-chip device for a phytoplankton group identification, based on cell analysis with multi-wavelength lighting excitation, aiming for a cheap and portable platform. With such methodology in a lab-on-a-chip device, the analysis of the phytoplankton cells’ optical properties, e.g., fluorescence, diffraction, absorption and reflection, will be possible. This device will offer, in the future, a platform for continuous, autonomous and in situ underwater measurements, in opposition to the conventional methodology. A proof-of-concept device with LED light excitation at 450 nm and a detection photodiode at 680 nm was fabricated. This device was able to quantify the concentration of the phytoplankton chlorophyll a. A lock-in amplifier electronic circuit was developed and integrated in a portable and low-cost sensor, featuring continuous, autonomous and in situ underwater measurements. This device has a detection limit of 0.01 µ/L of chlorophyll a, in a range up to 300 µg/L, with a linear voltage output with chlorophyll concentration.European Regional Development Fund (ERDF) through the Interreg VA Spain-Portugal (POCTEP) 2014–2020 Program under grant agreement 0591_FOODSENS_1_E, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020, and by project NORTE-08-5369-FSE-000039 co-founded by the European Social Fund FSE and through National funds NORTE 2020 and Regional Operacional Programa of North 2014/2020. The University of Vigo work was funded by a Xunta de Galicia grant to the Biological Oceanography Research Group (Consolidación e estruturación de unidades). This output reflects only the views of the authors, and the program authorities cannot be held responsible for any use that may be made of the information contained therei

    Sonic hedgehog expressing and responding cells generate neuronal diversity in the medial amygdala

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    <p>Abstract</p> <p>Background</p> <p>The mammalian amygdala is composed of two primary functional subdivisions, classified according to whether the major output projection of each nucleus is excitatory or inhibitory. The posterior dorsal and ventral subdivisions of the medial amygdala, which primarily contain inhibitory output neurons, modulate specific aspects of innate socio-sexual and aggressive behaviors. However, the development of the neuronal diversity of this complex and important structure remains to be fully elucidated.</p> <p>Results</p> <p>Using a combination of genetic fate-mapping and loss-of-function analyses, we examined the contribution and function of <it>Sonic hedgehog </it>(<it>Shh</it>)-expressing and <it>Shh</it>-responsive (<it>Nkx2-1</it><sup>+ </sup>and <it>Gli1</it><sup>+</sup>) neurons in the medial amygdala. Specifically, we found that <it>Shh- </it>and <it>Nkx2-1-</it>lineage cells contribute differentially to the dorsal and ventral subdivisions of the postnatal medial amygdala. These <it>Shh</it>- and <it>Nkx2-1</it>-lineage neurons express overlapping and non-overlapping inhibitory neuronal markers, such as Calbindin, FoxP2, nNOS and Somatostatin, revealing diverse fate contributions in discrete medial amygdala nuclear subdivisions. Electrophysiological analysis of the <it>Shh</it>-derived neurons additionally reveals an important functional diversity within this lineage in the medial amygdala. Moreover, inducible <it>Gli1<sup>CreER(T2) </sup></it>temporal fate mapping shows that early-generated progenitors that respond to <it>Shh </it>signaling also contribute to medial amygdala neuronal diversity. Lastly, analysis of <it>Nkx2-1 </it>mutant mice demonstrates a genetic requirement for <it>Nkx2-1 </it>in inhibitory neuronal specification in the medial amygdala distinct from the requirement for <it>Nkx2-1 </it>in cerebral cortical development.</p> <p>Conclusions</p> <p>Taken together, these data reveal a differential contribution of <it>Shh-</it>expressing and <it>Shh</it>-responding cells to medial amygdala neuronal diversity as well as the function of <it>Nkx2-1 </it>in the development of this important limbic system structure.</p
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