21,418 research outputs found

    Mushroom β-glucan and polyphenol formulations as natural immunity boosters and balancers: nature of the application

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    Mushrooms are experiencing a kind of renaissance as a part of the contemporary human diet. These valuable organisms are more than food, they fi t in perfectly as a novel market group known as nutra-mycoceuticals. Immune-balancing mushroom dietary fibers and secondary metabolites such as polyphenols are the main focus of the healthcare industry. Wellness and cosmetic companies are increasingly using mushroom extracts rich in these ingredients. This review considers the basic molecular immunomodulatory mechanisms of action of the most commonly used mushroom dietary fibers, β-glucans. The literature data on their bioavailability, metabolic transformations, preclinical and human clinical research, and safety are discussed. Immunomodulatory mechanisms of polyphenol ingredients are also considered. These molecules present great potential in the design of the new immunity balancer formulations according to their widespread structural diversity. Finally, we draw attention to the perspectives of modern trends in mushroom nutraceutical and cosmeceutical formulations to strengthen and balance immunity

    Circadian variations in aortic stiffness, sympathetic vasoconstriction, and post-ischemic vasodilation in adults with and without type 2 diabetes.

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    The current literature reveals a lack of information on the circadian variations of some important cardiovascular risk factors related to the work of the heart or the capacity to provide blood and oxygen to various tissues. These factors include aortic stiffness, peripheral vasoconstrictor responsiveness, and post-ischemic vasodilation capacity. Furthermore, it is not clear whether the impact of an external stressor capable of activating the sympathetic nervous system could have greater repercussions on the cardiovascular system in the morning than in the evening. Given the higher incidence of acute cardiovascular events in the morning than in the evening, the studies undertaken in this thesis aim to investigate the circadian variations of these factors that are linked to cardiovascular risk, both at rest and during acute activation of the sympathetic nervous system. Type 2 diabetes (T2DM) is a condition that induces deleterious changes in cardiovascular function, impacting cardiovascular mortality and morbidity. Thus, the impact of diabetes will be evaluated. As a secondary purpose, considering the sex differences in the incidence and prognosis of cardiovascular disease, the effect of sex will be evaluated. Aortic stiffness proved not to be increased in the morning compared to the evening at specific times when the cardiovascular risk is significantly different, both at rest and during sympathetic activation. However, while healthy older women show similar aortic stiffness values compared to their male counterparts during acute stress, older women with T2DM reported greater aortic stiffness compared to men with T2DM. The post-ischemic forearm vasodilation is blunted in the morning compared to the evening in healthy elderly and such an attenuated vasodilation capacity impairs blood flow supply towards the ischemic area. The presence of T2DM does not affect vasodilation capacity and reactive hyperemia, but induces circadian variations in arterial pressure. The peripheral vasoconstriction triggered by a standardized sympathetic stressor is similar between morning and evening, regardless of the presence of T2DM and reduced baseline vascular conductance values in the morning. However, the peripheral vasoconstriction responsiveness is blunted in individuals with T2DM than in healthy ones as sympathetic activation induces vasodilation on the contralateral forearm in individuals with T2DM and vasoconstriction in healthy age-matched subjects. This finding highlights a neurovascular response to an external stressor altered by T2DM. Taken together, our findings suggest that the baseline state of constriction of the peripheral vascular tissue is greater in the morning than in the evening, but this fact is not due to greater sympathetic vasoconstriction responsiveness in the morning. Higher morning vasoconstriction at baseline however affects the capacity of a vascular tissue to dilate and, in turn, to supply blood to an ischemic tissue. Similar sympathetic vasoconstriction responsiveness between morning and evening is a likely factor explaining similar or lower values of central artery stiffness in the morning than in the evening, not only at rest but also during sympathetic excitation. Paradoxically, adults with T2DM report an increase in sympathetic-mediated dilatation capacity on the vascular tissue, which might be a defense mechanism that allows to reduce the central pressor response during sympathetic excitation

    Annual SHOT Report 2018

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    SHOT is affiliated to the Royal College of PathologistsAll NHS organisations must move away from a blame culture towards a just and learning culture. All clinical and laboratory staff should be encouraged to become familiar with human factors and ergonomics concepts. All transfusion decisions must be made after carefully assessing the risks and benefits of transfusion therapy. Collaboration and co-ordination among staff is vital

    Physical model of end-diastolic and end-systolic pressure-volume relationships of a heart

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    Left ventricular (LV) stiffness and contractility, characterized by the end-diastolic and end-systolic pressure-volume relationships (EDPVR & ESPVR), are two important indicators of the performance of the human heart. Although much research has been conducted on EDPVR and ESPVR, no model with physically interpretable parameters combining both relationships has been presented, thereby impairing the understanding of cardiac physiology and pathology. Here, we present a model that evaluates both EDPVR and ESPVR with physical interpretations of the parameters in a unified framework. Our physics-based model fits the available experimental data and in silico results very well and outperforms existing models. With prescribed parameters, the new model is used to predict the pressure-volume relationships of the left ventricle. Our model provides a deeper understanding of cardiac mechanics and thus will have applications in cardiac research and clinical medicine.Comment: 14 pages, 8 figure

    Anuário científico da Escola Superior de Tecnologia da Saúde de Lisboa - 2021

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    É com grande prazer que apresentamos a mais recente edição (a 11.ª) do Anuário Científico da Escola Superior de Tecnologia da Saúde de Lisboa. Como instituição de ensino superior, temos o compromisso de promover e incentivar a pesquisa científica em todas as áreas do conhecimento que contemplam a nossa missão. Esta publicação tem como objetivo divulgar toda a produção científica desenvolvida pelos Professores, Investigadores, Estudantes e Pessoal não Docente da ESTeSL durante 2021. Este Anuário é, assim, o reflexo do trabalho árduo e dedicado da nossa comunidade, que se empenhou na produção de conteúdo científico de elevada qualidade e partilhada com a Sociedade na forma de livros, capítulos de livros, artigos publicados em revistas nacionais e internacionais, resumos de comunicações orais e pósteres, bem como resultado dos trabalhos de 1º e 2º ciclo. Com isto, o conteúdo desta publicação abrange uma ampla variedade de tópicos, desde temas mais fundamentais até estudos de aplicação prática em contextos específicos de Saúde, refletindo desta forma a pluralidade e diversidade de áreas que definem, e tornam única, a ESTeSL. Acreditamos que a investigação e pesquisa científica é um eixo fundamental para o desenvolvimento da sociedade e é por isso que incentivamos os nossos estudantes a envolverem-se em atividades de pesquisa e prática baseada na evidência desde o início dos seus estudos na ESTeSL. Esta publicação é um exemplo do sucesso desses esforços, sendo a maior de sempre, o que faz com que estejamos muito orgulhosos em partilhar os resultados e descobertas dos nossos investigadores com a comunidade científica e o público em geral. Esperamos que este Anuário inspire e motive outros estudantes, profissionais de saúde, professores e outros colaboradores a continuarem a explorar novas ideias e contribuir para o avanço da ciência e da tecnologia no corpo de conhecimento próprio das áreas que compõe a ESTeSL. Agradecemos a todos os envolvidos na produção deste anuário e desejamos uma leitura inspiradora e agradável.info:eu-repo/semantics/publishedVersio

    A direct-laser-written heart-on-a-chip platform for generation and stimulation of engineered heart tissues

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    In this dissertation, we first develop a versatile microfluidic heart-on-a-chip model to generate 3D-engineered human cardiac microtissues in highly-controlled microenvironments. The platform, which is enabled by direct laser writing (DLW), has tailor-made attachment sites for cardiac microtissues and comes with integrated strain actuators and force sensors. Application of external pressure waves to the platform results in controllable time-dependent forces on the microtissues. Conversely, oscillatory forces generated by the microtissues are transduced into measurable electrical outputs. After characterization of the responsivity of the transducers, we demonstrate the capabilities of this platform by studying the response of cardiac microtissues to prescribed mechanical loading and pacing. Next, we tune the geometry and mechanical properties of the platform to enable parametric studies on engineered heart tissues. We explore two geometries: a rectangular seeding well with two attachment sites, and a stadium-like seeding well with six attachment sites. The attachment sites are placed symmetrically in the longitudinal direction. The former geometry promotes uniaxial contraction of the tissues; the latter additionally induces diagonal fiber alignment. We systematically increase the length for both configurations and observe a positive correlation between fiber alignment at the center of the microtissues and tissue length. However, progressive thinning and “necking” is also observed, leading to the failure of longer tissues over time. We use the DLW technique to improve the platform, softening the mechanical environment and optimizing the attachment sites for generation of stable microtissues at each length and geometry. Furthermore, electrical pacing is incorporated into the platform to evaluate the functional dynamics of stable microtissues over the entire range of physiological heart rates. Here, we typically observe a decrease in active force and contraction duration as a function of frequency. Lastly, we use a more traditional ?TUG platform to demonstrate the effects of subthreshold electrical pacing on the rhythm of the spontaneously contracting cardiac microtissues. Here, we observe periodic M:N patterns, in which there are ? cycles of stimulation for every ? tissue contractions. Using electric field amplitude, pacing frequency, and homeostatic beating frequencies of the tissues, we provide an empirical map for predicting the emergence of these rhythms

    Physiological Adaptions to Acute Hypoxia

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    When tissues are insufficiently supplied with oxygen, the environment is said to be hypoxic. Acute (exposures to) hypoxia can occur occupationally, within the scope of training and competitions or under pathological conditions. The increasing interest in acute exposure to altitude for training and research purposes makes it more important than ever to understand the physiological processes that occur under hypoxic conditions. Therefore, the scope of this chapter is to describe the main types of hypoxia on the oxygen cascade, to summarize the physiological consequences of acute hypoxia on the three main areas and to highlight the clinical consequences of acute hypoxia exposures for healthcare practitioners

    Influence of Insulin Resistance and Obesity on the Autonomic Regulation of Rat Heart Rate under Conditions of Adequate and Limited Iodine Supply

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    Cardiovascular diseases remain a major medical problems in most countries around the world, causing significant economic disbenefit. An important pathogenetic mechanism of the influence of insulin resistance and hypothyroidism on the cardiovascular system is the alteration in the autonomic regulation of heart rhythm. Objective. The aim of the study was to evaluate the dynamics of heart rate variability (HRV) in rats with insulin resistance and obesity under the conditions of adequate and limited iodine supply. Materials and Methods. Studies were performed on 90 nonlinear rats pandomized by random sampling. The response of the autonomic nervous system (ANS) was studied using a computer program to analyze HRV “Poly-Spectrum.NET” with the additional module “Poly-Spectrum.NET/Veterinary”. Results. It was determined that the co-directed dynamics of geometric and statistical analysis of HRV and balance shift in the direction of the low-frequency component in spectrum analysis of the heart rate regarding control data were revealed in rats with isolated insulin resistance, obesity and combined endocrinopathy (insulin resistance and obesity under the conditions of limited iodine supply).  Conclusion. The prevalence of sympathetic ANS activity under the conditions of insulin resistance and obesity can contribute to cardiac arrhythmias, the development of diabetic autonomic neuropathy and with a high probability to cause some cases of life-threatening arrhythmias (supraventricular and ventricular). Iodine deficiency contributes to the depletion of regulatory effects of ANS and limits the range of adaptive capabilities and resources of the organism.Серцево-судинні захворювання залишаються основною медичною проблемою в більшості країн світу, зумовлюючи значні економічні збитки. Важливий патогенетичний механізм впливу на серцево-судинну систему має інсулінорезистентність, ожиріння та йододефіцит. Мета. Метою даного дослідження було вивчити особливості варіабельності серцевого ритму у щурів із інсулінорезистентністю та ожирінням за умов належного та обмеженого забезпечення йодом. Матеріали та методи. Дослідження проведені на 90 нелінійних щурах, paндoмiзовaних мeтoдoм випaдкoвoї вибipки. Вивчали реакцію автономної нервової системи із застосуванням комп'ютерної програми для аналізу варіабельності серцевого ритму (ВСР) «Полі-Спектр.NET» з додатковим модулем «Полі-Спектр.NET/Ветеринарія». Визначали показники геометричного, статистичного та спектрального аналізу ВСР. Результати. Установлено, що у щурів із ізольованою інсулінорезистентністю, ожирінням та комбінованою ендокринопатією (інсулінорезистентністю та ожирінням за умов обмеженого забезпечення йодом) виявлено співнапрямлену динаміку показників геометричного та статистичного аналізу ВСР і зміщення балансу в бік низькочастотного компонента при спектральному аналізі серцевого ритму щодо даних контролю. Висновок. Превалювання симпатичної активності автономної нервової системи за умов інсулінорезистентності та ожиріння може сприяти порушенню серцевого ритму, з високою ймовірністю зумовлювати випадки життєво небезпечних аритмій (суправентрикулярних та шлуночкових), розвиток діабетичної автономної нейропатії. Дефіцит йоду сприяє виснаженню регуляторних впливів автономної нервової системи та зумовлює обмеження діапазону адаптаційних можливостей організму. Ключові слова: варіабельність серцевого ритму, автономна нервова система, інсулінорезистентність, ожиріння, йододефіцит

    Clinical and pathophysiological characterization of patients with acutely decompensated cirrhosis and acute-on-chronic liver failure

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    In the last decade, our understanding of the pathophysiological mechanisms underlying decompensated cirrhosis has greatly increased. Moreover, acute-on-chronic liver failure (ACLF) was defined as a distinct syndrome with specific features. Our research activities aimed to provide a contribution in characterizing patients with acutely decompensated cirrhosis and ACLF from a clinical and a pathophysiological perspective. As a first project, we addressed the clinical issue of predicting in-hospital development of ACLF in patients hospitalized for acute decompensation of cirrhosis. As a second contribution, we performed a reassessment of the whole metabolomic dataset obtained from 831 patients enrolled in the CANONIC study, focusing on amino acids, with the aim to uncover alterations in amino acids metabolic pathways. As a third perspective, we performed a GWAS on 270 patients with acute decompensation and ACLF included in the first clinical study. We categorized patients in 4 groups, according to their clinical presentation and their clinical course. We then performed two comparisons: group 1 vs group 4 (i.e., the most severe vs the mildest clinical courses), and group 1 vs group 2 (i.e., patients with different 1-year outcomes from a common clinical presentation with ACLF or bacterial infection). Three SNPs (rs9354118 on chromosome 6q16.1; rs1146878 on chromosome 13q22.2; rs6479397 on chromosome 9q22.31) were significantly associated with the selected phenotypes, but all of them were located in non-codifying DNA regions. However, their potential role as candidate Cis-Regulatory Elements (cCREs) opened interesting hypotheses on effects on the expression of neighboring genes. Indeed, four of them (FUT9 and UFL1 for SNP rs9354118, LMO7 and ACOD1 for rs1146878) are involved in the modulation of immune system activation and systemic inflammation. The results of the GWAS did not confirm previous findings reported in literature and presented some limitations. However, it provided the basis for further research in this still open issue

    Influence of local PO₂ on skeletal muscle microvascular blood flow during hyperinsulinemia

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    The goal of this thesis was to test the hypothesis that insulin mediated hyperemia is partially dependent on local muscle oxygen concentration. To do so, microvascular blood flow was measured in response to varying imposed concentrations of oxygen in rat skeletal muscle. Sprague-Dawley rats were anesthetized, and the extensor digitorum longus (EDL) was reflected onto an inverted microscope. Intravital video microscopy sequences were recorded during baseline and hyperinsulinemic euglycemia. The muscle was reflected over a glass stage insert (Experiment 1a and 1b), or over a gas exchange chamber (Experiment 2), and microvascular capillary blood flow was recorded during sequential changes (7%-12%-2%-7%) of oxygen (O₂) concentration. Blood flow was measured by the red blood cell supply rate (SR) in number of cells per second. In Experiment 1a, supply rate (SR) increased from 8.0 to 14 cells/s at baseline to euglycemia (p = 0.01), while no significant SR variation was detected after performing a sham hyperinsulinemic euglycemic clamp (Experiment 1b). In Experiment 2, SR decreased at 12% O₂ and increased at 2% O₂, compared to 7% O₂, under both experimental conditions. SR responses to oxygen square wave oscillations during euglycemia were not different to those at baseline at each O₂ concentration (p > 0.9). Our results suggest the increase in blood flow observed in response to insulin is eliminated if tissue oxygen microenvironment is clamped at given oxygen concentrations. All animal protocols were approved by Memorial University’s Institutional Animal Care Committee
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