275 research outputs found

    Temporal changes in cardiac oxidative stress, inflammation and remodeling induced by exercise in hypertension: Role for local angiotensin II reduction

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    Exercise training reduces renin-angiotensin system (RAS) activation, decreases plasma and tissue oxidative stress and inflammation in hypertension. However, the temporal nature of these phenomena in response to exercise is unknown. We sought to determine in spontaneously hypertensive rats (SHR) and age-matched WKY controls the weekly effects of training on blood pressure (BP), plasma and left ventricle (LV) Ang II and Ang-(1–7) content (HPLC), LV oxidative stress (DHE staining), gene and protein expression (qPCR and WB) of pro-inflammatory cytokines, antioxidant enzymes and their consequence on hypertension-induced cardiac remodeling. SHR and WKY were submitted to aerobic training (T) or maintained sedentary (S) for 8 weeks; measurements were made at weeks 0, 1, 2, 4 and 8. Hypertension-induced cardiac hypertrophy was accompanied by acute plasma Ang II increase with amplified responses during the late phase of LV hypertrophy. Similar pattern was observed for oxidative stress markers, TNF alpha and interleukin-1β, associated with cardiomyocytes’ diameter enlargement and collagen deposition. SHR-T exhibited prompt and marked decrease in LV Ang II content (T1 vs T4 in WKY-T), normalized oxidative stress (T2), augmented antioxidant defense (T4) and reduced both collagen deposition and inflammatory profile (T8), without changing cardiomyocytes’ diameter and LV hypertrophy. These changes were accompanied by decreased plasma Ang II content (T2-T4) and reduced BP (T8). SHR-T and WKY-T showed parallel increases in LV and plasma Ang-(1–7) content. Our data indicate that early training-induced downregulation of LV ACE-AngII-AT1 receptor axis is a crucial mechanism to reduce oxidative/pro-inflammatory profile and improve antioxidant defense in SHR-T, showing in addition this effect precedes plasma RAS deactivation

    Oxidative Stress in Neurodegenerative Diseases: Mechanisms and Therapeutic Perspectives

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    The incidence and prevalence of neurodegenerative diseases (ND) increase with life expectancy. This paper reviews the role of oxidative stress (OS) in ND and pharmacological attempts to fight against reactive oxygen species (ROS)-induced neurodegeneration. Several mechanisms involved in ROS generation in neurodegeneration have been proposed. Recent articles about molecular pathways involved in ROS generation were reviewed. The progress in the development of neuroprotective therapies has been hampered because it is difficult to define targets for treatment and determine what should be considered as neuroprotective. Therefore, the attention was focused on researches about pharmacological targets that could protect neurons against OS. Since it is necessary to look for genes as the ultimate controllers of all biological processes, this paper also tried to identify gerontogenes involved in OS and neurodegeneration. Since neurons depend on glial cells to survive, recent articles about the functioning of these cells in aging and ND were also reviewed. Finally, clinical trials testing potential neuroprotective agents were critically reviewed. Although several potential drugs have been screened in in vitro and in vivo models of ND, these results were not translated in benefit of patients, and disappointing results were obtained in the majority of clinical trials

    Modeling of FiO2 delivered by self-inflating ventilation device: Modelagem de FiO2 entregue por bolsa auto inflável

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    During the COVID-19 pandemic, professionals in the medical field have been using bag resuscitators, also called bag valve masks, to provide respiratory support for patients for long periods. A relevant issue arising because of such use is the little information regarding the FiO2 delivered by these devices, leading to toxic effects of O2 and its waste. This paper presents a model that relates volume, respiratory frequency, and flow in an O2 line with the FiO2 delivered by bag resuscitators. The model was obtained based on a formal procedure and data from a 1500 ml Hsiner bag resuscitator collected in the literature, both presented in this paper. Then, we compared through Bland-Altman analysis the FiO2 values estimated by our model with the ones from data considering different bag resuscitators to evaluate the amplitude of the errors it can generate. The average error for Hsiner and Laerdal bag resuscitators was less than 0.035 (or 3.5%) and less than 0.063 (or 6.3%) for Ambu devices. The maximum error found for Ambu bag resuscitators was high. The obtained model presented satisfactory errors, compatible with the uncertainty levels associated with FiO2 measuring instruments and blenders, meaning the model can be used to estimate the delivered FiO2 accurately. Additionally, the procedure presented in this paper can be used to obtain specific models for bag resuscitators of other companies, equipping professionals with tools that can accurately estimate FiO2

    Prevalence and phylogenetic analysis of haemoplasmas from cats infected with multiple species

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    AbstractMycoplasma haemofelis (Mhf), ‘Candidatus Mycoplasma haemominutum’ (CMhm) and ‘Candidatus Mycoplasma turicensis’ (CMt) are agents of feline haemoplasmosis and can induce anaemia in cats. This study aimed to determine the prevalence and phylogeny of haemoplasma species in cats from Brazil's capital and surrounding areas, and whether correlation with haematological abnormalities existed. Feline haemoplasmas were found in 13.8% of 432 cats. CMhm was the most prevalent species (in 13.8% of cats), followed by Mhf (11.1%) and CMt (4.4%). Over 80% of haemoplasma-infected cats harboured two or more feline haemoplasma species: 7.1% of cats were co-infected with Mhf/CMhm, 0.4% with CMhm/CMt and 3.9% with Mhf/CMhm/CMt. Male gender was significantly associated with haemoplasma infections. No association was found between qPCR haemoplasma status and haematological variables, however CMhm relative copy numbers were correlated with red blood cell (RBC) numbers and packed cell volume (PCV). Haemoplasma 16S rRNA gene sequences (>1Kb) were derived from co-infected cats using novel haemoplasma species-specific primers. This allowed 16S rRNA gene sequences to be obtained despite the high level of co-infection, which precluded the use of universal 16S rRNA gene primers. Within each species, the Mhf, CMhm and CMt sequences showed >99.8%, >98.5% and >98.8% identity, respectively. The Mhf, CMhm and CMt sequences showed >99.2%, >98.4% and >97.8% identity, respectively, with GenBank sequences. Phylogenetic analysis showed all Mhf sequences to reside in a single clade, whereas the CMhm and CMt sequences each grouped into three distinct subclades. These phylogeny findings suggest the existence of different CMhm and CMt strains

    Epidemiology of COVID-19 in the State of Sergipe/Brazil and Its Relationship with Social Indicators

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    A pandemic is capable of generating a great impact, not only from the point of view of health, but also socioeconomically. In March 2020, the World Health Organization (WHO) declared that a new pandemic situation had arisen, due to the SARS-CoV-2 virus, whose probable origin was zoonotic. The largest number of cases of this disease is concentrated in the United States of America (USA), India, and Brazil. The mortality rate is estimated at 3.4%, but regional differences may exist, and places with a high demographic density have become true epicentres and may be related to higher rates of transmission. In addition to the above, lower human development indexes (HDI) can be related to worse outcomes, especially in the North and Northeast regions of Brazil since they are the least developed places. The Northeast region is the second-most-affected place in the number of COVID-19 cases in Brazil. An analytical observational study of an ecological type was carried out from April to October 2020 to assess the epidemiological situation of COVID-19 in the state of Sergipe and specifically to analyse the incidence of cases and deaths resulting from COVID-19 in the different health regions of the state of Sergipe, in relation to the values of the HDI and demographic density. During the study period, 84,325 cases of COVID-19 were identified, in which 2205 resulted in death. In most of the regions studied, there was a positive association between the number of cases and deaths and the greater the demographic density, but there was no increase in the risk of becoming ill, nor of dying the lower the HDI. Large and crowded cities are places of greatest vulnerability to illness, due to their greater capacity of transmitting the virus; however, further studies are needed to identify other factors that are decisive in the outcomes of this new disease.This research received no external funding.info:eu-repo/semantics/publishedVersio

    MAPEAMENTO DE VOÇOROCAS E DO RISCO DE EROSÃO EM ÁREA URBANA NO OESTE DO ESTADO DO MARANHÃO

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    Dentre os fatores de erosão, a erodibilidade combinada a um relevo irregular, assume posição de destaque e determina o grau de susceptibilidade dos solos a serem erodidos. Por outro lado, as atividades desenvolvidas pelo homem alteram a dinâmica desse processo, acelerando suas ações. Em Buriticupu, município situado na porção centro oeste do Estado do Maranhão, os solos já tiveram sua erodibilidade elevada mencionada em diversos trabalhos, porém nenhum estudo que determinem valores para os atributos químicos e físicos dos solos foi elaborado e publicado. Neste sentido, a presente pesquisa objetivou identificar e mapear os processos erosivos por voçorocamento na sede municipal de Buriticupu – MA. O município sofre com os problemas erosivos, já sendo percebidas voçorocas que fizeram desaparecer residências e que aumentam sua ação, em especial no período mais intenso das chuvas. As atividades humanas associadas à impermeabilização de vias e condução das águas pluviais e esgotos para as encostas sem canal escoadouro, galeria ou tubulação, associadas ao uso e ocupação das encostas são atividades que aceleram intensamente a erosão, fato que tem causado danos ambientais e sociais das comunidades situados no entorno das inúmeras voçorocas situadas em Buriticupu

    Smoking-induced aggravation of experimental arthritis is dependent of aryl hydrocarbon receptor activation in Th17 cells.

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    Background: Epidemiologic studies have highlighted the association of environmental factors with the development and progression of autoimmune and chronic inflammatory diseases. Among the environmental factors, smoking has been associated with increased susceptibility and poor prognosis in rheumatoid arthritis (RA). However, the immune and molecular mechanism of smoking-induced arthritis aggravation remains unclear. The transcription factor aryl hydrocarbon receptor (AHR) regulates the generation of Th17 cells, CD4 T cells linked the development of autoimmune diseases. AHR is activated by organic compounds including polycyclic aromatic hydrocarbons (PAHs), which are environmental pollutants that are also present in cigarette smoke. In this study, we investigated the role of AHR activation in the aggravation of experiment arthritis induced by exposure to cigarette smoke. Methods: Mice were exposed to cigarette smoke during the developmental phase of antigen-induced arthritis and collagen-induced arthritis to evaluate the effects of smoking on disease development. Aggravation of articular inflammation was assessed by measuring neutrophil migration to the joints, increase in articular hyperalgesia and changes in the frequencies of Th17 cells. In vitro studies were performed to evaluate the direct effects of cigarette smoke and PAH on Th17 differentiation. We also used mice genetically deficient for AHR (Ahr KO) and IL-17Ra (Il17ra KO) to determine the in vivo mechanism of smoking-induced arthritis aggravation. Results: We found that smoking induces arthritis aggravation and increase in the frequencies of Th17 cells. The absence of IL-17 signaling (Il17ra KO) conferred protection to smoking-induced arthritis aggravation. Moreover, in vitro experiments showed that cigarette smoke can directly increase Th17 differentiation of T cells by inducing AHR activation. Indeed, Ahr KO mice were protected from cigarette smoke-induced arthritis aggravation and did not display increase in TH17 frequencies, suggesting that AHR activation is an important mechanism for cigarette smoke effects on arthritis. Finally, we demonstrate that PAHs are also able to induce arthritis aggravation. Conclusions: Our data demonstrate that the disease-exacerbating effects of cigarette smoking are AHR dependent and environmental pollutants with AHR agonist activity can induce arthritis aggravation by directly enhancing Th17 cell development

    Uso terapêutico da aloe vera no processo de cicatrização: revisão sistemática / Therapeutic use of aloe vera in the healing process: a systematic review

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    INTRODUÇÃO:O uso terapêutico da Aloe Vera faz parte da fitoterapia que é uma técnica de tratamento ou prevenção de doenças através do uso de plantas. Trata-se de uma forma tradicional de tratamento e o Aloe vera (L)Burm. f., a popular babosa ou aloés, é uma planta xerófita, apresenta na anatomia botânica de suas folhas mucilagem de ação cicatrizante, antibacteriana e anti-inflamatória proporcionadas pela presença de substâncias fenólicas, como aloenina, barbaloina e isobarbaloina em sua composição química. OBJETIVO: Verificar o potencial fitoterápico da Aloe Vera utilizada no processo de cicatrização de feridas. MÉTODOS:Estudo de revisão sistemática, utilizando a ferramenta de busca acadêmica b-on, que contém diferentes bases bibliográficas. Foram aplicados os critérios PRISMA para redigir o relatório da revisão. Foram incluídos artigos originais de pesquisa quantitativa e qualitativa. Os critérios de exclusão foram: artigos anteriores a data de 2012, de opinião ou estudo que não aborde o objetivo do estudo, ou escritos numa língua diferente do português. RESULTADOS: Pesquisas mostraram quea Aloe Vera aumenta a vascularização, fornece mais oxigenação, aumenta a produção de colágeno, garantindo fatores essenciais para a remodelação do tecido, fazendo com que o uso terapêutico com Aloe Vera na cicatrização, faz com que o tecido seja desinflamado e as células epiteliais sejam multiplicadas, proporcionando, por fim, um tecido completamente cicatrizado. CONCLUSÕES: Verificou-se que os benefícios do uso terapêutico com Alo Vera para cicatrização têm grande potencial fitoterápico no tratamento de cicatrização de feridas
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