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Sepsis, defined as organ dysfunction caused by a dysregulated host-response to infection, is characterized by immunosuppression. The vasopressor norepinephrine is widely used to treat low blood pressure in sepsis but exacerbates immunosuppression. An alternative vasopressor is angiotensin-II, a peptide hormone of the renin-angiotensin system (RAS), which displays complex immunomodulatory properties that remain unexplored in severe infection. In a murine cecal ligation and puncture (CLP) model of sepsis, we found alterations in the surface levels of RAS proteins on innate leukocytes in peritoneum and spleen. Angiotensin-II treatment induced biphasic, angiotensin-II type 1 receptor (AT1R)-dependent modulation of the systemic inflammatory response and decreased bacterial counts in both the blood and peritoneal compartments, which did not occur with norepinephrine treatment. The effect of angiotensin-II was preserved when treatment was delivered remote from the primary site of infection. At an independent laboratory, angiotensin-II treatment was compared in LysM-Cre AT1aR-/- (Myeloid-AT1a-) mice, which selectively do not express AT1R on myeloid-derived leukocytes, and littermate controls (Myeloid-AT1a+). Angiotensin-II treatment significantly reduced post-CLP bacteremia in Myeloid-AT1a+ mice but not in Myeloid-AT1a- mice, indicating that the AT1R-dependent effect of angiotensin-II on bacterial clearance was mediated through myeloid-lineage cells. Ex vivo, angiotensin-II increased post-CLP monocyte phagocytosis and ROS production after lipopolysaccharide stimulation. These data identify a mechanism by which angiotensin-II enhances the myeloid innate immune response during severe systemic infection and highlight a potential role for angiotensin-II to augment immune responses in sepsis.
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Angiotensina II , Bacteriemia/imunologia , Células Mieloides/metabolismo , Sepse/imunologia , Angiotensina II/metabolismo , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Norepinefrina/metabolismo , Receptor Tipo 1 de Angiotensina , Sepse/metabolismo , Transdução de SinaisRESUMO
BACKGROUND: The contribution of the central nervous system to sepsis pathobiology is incompletely understood. In previous studies, administration of endotoxin to mice decreased activity of the vagus anti-inflammatory reflex. Treatment with the centrally-acting M1 muscarinic acetylcholine (ACh) receptor (M1AChR) attenuated this endotoxin-mediated change. We hypothesize that decreased M1AChR-mediated activity contributes to inflammation following cecal ligation and puncture (CLP), a mouse model of sepsis. METHODS: In male C57Bl/6 mice, we quantified basal forebrain cholinergic activity (immunostaining), hippocampal neuronal activity, serum cytokine/chemokine levels (ELISA) and splenic cell subtypes (flow cytometry) at baseline, following CLP and following CLP in mice also treated with the M1AChR agonist xanomeline. RESULTS: At 48 h. post-CLP, activity in basal forebrain cells expressing choline acetyltransferase (ChAT) was half of that observed at baseline. Lower activity was also noted in the hippocampus, which contains projections from ChAT-expressing basal forebrain neurons. Serum levels of TNFα, IL-1ß, MIP-1α, IL-6, KC and G-CSF were higher post-CLP than at baseline. Post-CLP numbers of splenic macrophages and inflammatory monocytes, TNFα+ and ILß+ neutrophils and ILß+ monocytes were higher than baseline while numbers of central Dendritic Cells (cDCs), CD4+ and CD8+ T cells were lower. When, following CLP, mice were treated with xanomeline activity in basal forebrain ChAT-expressing neurons and in the hippocampus was significantly higher than in untreated animals. Post-CLP serum concentrations of TNFα, IL-1ß, and MIP-1α, but not of IL-6, KC and G-CSF, were significantly lower in xanomeline-treated mice than in untreated mice. Post-CLP numbers of splenic neutrophils, macrophages, inflammatory monocytes and TNFα+ neutrophils also were lower in xanomeline-treated mice than in untreated animals. Percentages of IL-1ß+ neutrophils, IL-1ß+ monocytes, cDCs, CD4+ T cells and CD8+ T cells were similar in xanomeline-treated and untreated post-CLP mice. CONCLUSION: Our findings indicate that M1AChR-mediated responses modulate CLP-induced alterations in serum levels of some, but not all, cytokines/chemokines and affected splenic immune response phenotypes.
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Citocinas , Piridinas , Sepse , Tiadiazóis , Masculino , Camundongos , Animais , Citocinas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6 , Linfócitos T CD8-Positivos/metabolismo , Quimiocina CCL3 , Quimiocinas , Punções , Endotoxinas , Encéfalo/metabolismo , Ligadura , Colinérgicos , Fator Estimulador de Colônias de Granulócitos , Camundongos Endogâmicos C57BL , Ceco/metabolismo , Modelos Animais de DoençasRESUMO
Cardiovascular and metabolic diseases such as hypertension, type 2 diabetes, and obesity develop long-term fibrotic processes in the heart, promoting pathological cardiac remodeling, including after myocardial infarction, reparative fibrotic processes also occur. These processes are regulated by many intracellular signaling pathways that have not yet been completely elucidated, including those associated with microRNA (miRNA) expression. miRNAs are small RNA transcripts (18-25 nucleotides in length) that act as posttranscriptionally regulators of gene expression, inhibiting or degrading one or more target messenger RNAs (mRNAs), and proven to be involved in many biological processes such as cell cycle, differentiation, proliferation, migration, and apoptosis, directly affecting the pathophysiology of several diseases, including cardiac fibrosis. Exercise training can modulate the expression of miRNAs and it is known to be beneficial in various cardiovascular diseases, attenuating cardiac fibrosis processes. However, the signaling pathways modulated by the exercise associated with miRNAs in cardiac fibrosis were not fully understood. Thus, this review aims to analyze the expression of miRNAs that modulate signaling pathways in cardiac fibrosis processes that can be regulated by exercise training.
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Diabetes Mellitus Tipo 2 , MicroRNAs , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Exercício Físico , Transdução de Sinais , RNA Mensageiro/genética , FibroseRESUMO
Overactivation of the classic arm of the renin-angiotensin system (RAS) is one of the main mechanisms involved in obesity-related cardiac remodeling, and a possible relationship between RAS and ER stress in the cardiovascular system have been described. Thus, the aim of this study is to evaluate if activating the protective arm of the RAS by ACE inhibition or aerobic exercise training could overturn diet-induced pathological cardiac hypertrophy by attenuating ER stress. Male C57BL/6 mice were fed a control (SC) or a high-fat diet (HF) for 16 weeks. In the 8th week, HF-fed animals were randomly divided into HF, enalapril treatment (HF-En), and aerobic exercise training (HF-Ex) groups. Body mass (BM), food and energy intake, plasma analyzes, systolic blood pressure (SBP), physical conditioning, and plasma ACE and ACE2 activity were evaluated. Cardiac morphology, and protein expression of hypertrophy, cardiac metabolism, RAS, and ER stress markers were assessed. Data presented as mean ± standard deviation and analyzed by one-way ANOVA with Holm-Sidak post-hoc. HF group had increased BM and SBP, and developed pathological concentric cardiac hypertrophy, with overactivation of the classic arm of the RAS, and higher ER stress. Both interventions reverted the increase in BM, and SBP, and favored the protective arm of the RAS. Enalapril treatment improved pathological cardiac hypertrophy with partial reversal of the concentric pattern, and slightly attenuated cardiac ER stress. In contrast, aerobic exercise training induced physiological eccentric cardiac hypertrophy, and fully diminished ER stress.
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Orthoregeneration is defined as a solution for orthopaedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and, optimally, provide an environment for tissue regeneration. Options include drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electromagnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the elbow and upper extremity, including the tendons (lateral epicondylitis, medial epicondylitis, biceps tendonitis, triceps tendonitis), articular cartilage (osteoarthritis, osteochondral lesions), and bone (fractures, nonunions, avascular necrosis, osteonecrosis). Promising and established treatment modalities include hyaluronic acid; botulinum toxin; corticosteroids; leukocyte-rich and leukocyte-poor platelet-rich plasma; autologous blood; bone marrow aspirate comprising mesenchymal stromal cells (alternatively termed medicinal signaling cells and frequently mesenchymal stem cells [MSCs]) and bone marrow aspirate concentrate; MSCs harvested from adipose and skin (dermis) sources; vascularized bone grafts; bone morphogenic protein scaffold made from osteoinductive and conductive ß-tricalcium phosphate and poly-ε-caprolactone with hydrogels, human MSCs, and matrix metalloproteinases; and collagen sponge. Autologous blood preparations such as autologous blood injections and platelet-rich plasma show positive outcomes for nonresponsive tendinopathy. In addition, cellular therapies such as tissue-derived tenocyte-like cells and MSCs show a promising ability to regulate degenerative processes by modulating tissue response to inflammation and preventing continuous degradation and support tissue restoration.
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Climate change is a defining issue for our generation. The carbon footprint of clinical practice accounts for 4.7% of European greenhouse gas emissions, with the European Union ranking as the third largest contributor to the global healthcare industry's carbon footprint, after the United States and China. Recognising the importance of urgent action, the European Society of Anaesthesiology and Intensive Care (ESAIC) adopted the Glasgow Declaration on Environmental Sustainability in June 2023. Building on this initiative, the ESAIC Sustainability Committee now presents a consensus document in perioperative sustainability. Acknowledging wider dimensions of sustainability, beyond the environmental one, the document recognizes healthcare professionals as cornerstones for sustainable care, and puts forward recommendations in four main areas: direct emissions, energy, supply chain and waste management, and psychological and self-care of healthcare professionals. Given the urgent need to cut global carbon emissions, and the scarcity of evidence-based literature on perioperative sustainability, our methodology is based on expert opinion recommendations. A total of 90 recommendations were drafted by 13 sustainability experts in anaesthesia in March 2023, then validated by 36 experts from 24 different countries in a two-step Delphi validation process in May and June 2023. To accommodate different possibilities for action in high- versus middle-income countries, an 80% agreement threshold was set to ease implementation of the recommendations Europe-wide. All recommendations surpassed the 80% agreement threshold in the first Delphi round, and 88 recommendations achieved an agreement >90% in the second round. Recommendations include the use of very low fresh gas flow, choice of anaesthetic drug, energy and water preserving measures, "5R" policies including choice of plastics and their disposal, and recommendations to keep a healthy work environment or on the importance of fatigue in clinical practice. Executive summaries of recommendations in areas 1, 2 and 3 are available as cognitive aids that can be made available for quick reference in the operating room.
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Anestesia , Anestesiologia , Humanos , Consenso , China , Cuidados CríticosRESUMO
PURPOSE: Malignant otitis externa (MOE) is a rare form of invasive osteomyelitis of the external ear canal. It is typically caused by Pseudomonas aeruginosa in immunocompromised patients. The diagnosis is clinical, and the initial treatment involves systemic antibiotics or antifungal therapy. Surgery is usually only considered when medical treatment has failed. Although hyperbaric oxygen therapy (HBOT) is recommended for refractory osteomyelitis, there are no specific guidelines for MOE. METHODS: This is a retrospective study that evaluates clinical data, treatment, and results obtained in patients diagnosed with MOE treated with HBOT at the Pedro Hispano Hospital between 2007 and 2022. RESULTS: During the study period, fifteen patients diagnosed with MOE were admitted for treatment with HBOT. All patients received antibiotic and/or antifungal therapy, and three required surgical intervention before starting HBOT. The pathology was successfully managed on all patients. CONCLUSIONS: HBOT may be an effective adjuvant treatment option in patients with MOE but it lacks robust scientific evidence. However, its therapeutic value should not be underestimated due to the good results and few adverse effects reported in recent retrospective studies and case reports.
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Circular RNAs (circRNAs) are a family of noncoding RNAs (ncRNAs) that are endogenous and widely distributed in different species, performing several functions, mainly their association with microRNAs (miRNAs) and RNA-binding proteins. CVDs remain the leading cause of death worldwide; therefore, the development of new therapies and strategies, such as gene therapies or nonpharmacological therapies, with low cost, such as physical exercise, to alleviate these diseases is of extreme importance for society. With increasing evidence of ncRNA participating in the progression of CVDs, several studies have reported these RNAs as promising targets for diagnosis and treatment. There are several studies of CVDs and the role of miRNAs and lncRNAs; however, little is known about the new class of RNAs, called circRNAs, and CVDs. In this mini review, we focus on the mechanisms of circRNAs and CVDs.
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Doenças Cardiovasculares , MicroRNAs , RNA Longo não Codificante , Humanos , RNA Circular/genética , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/terapia , MicroRNAs/genética , MicroRNAs/metabolismo , RNA não Traduzido/genética , RNA Longo não Codificante/genéticaRESUMO
Type 2 diabetes mellitus (T2DM) is a multifactorial metabolic disease, and its prevalence has grown worldwide. Several pathophysiological processes contribute to the development, progression and aggravating of the disease, for example, decreased insulin synthesis and secretion, insulin resistance, inflammation, and apoptosis, all these processes are regulated by various epigenetic factors, including microRNAs (miRNAs). MiRNAs are small non-coding RNAs, which are around 20 nucleotides in length and are regulators of gene expression at the post-transcriptional level, have a specific function of inhibiting or degrading a messenger RNA target. Thus, miRNAs modulate the expression of many associated genes with the pathophysiological processes in T2DM. On the other hand, miRNAs are also modulated through physical exercise (PE), which induces a change in their expression pattern during and after exercise. Some scientific evidence shows that PE modulates miRNAs beneficially and improves the signaling pathway of insulin resistance, however, little is known about the function of PE modulating miRNAs associated with the processes of insulin secretion, inflammation, and apoptosis. Thus, the objective of this review is to identify the miRNAs expression pattern in T2DM and compare it with the exercise-induced miRNAs expression pattern, identifying the signaling pathways that these miRNAs are regulating in the processes of insulin secretion, insulin resistance, inflammation, and apoptosis in T2DM, and how PE may have a potential role in modulating these signal transduction pathways, promoting benefits for patients with T2DM.
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Diabetes Mellitus Tipo 2 , Exercício Físico , Resistência à Insulina , MicroRNAs , Transdução de Sinais , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/terapia , Humanos , Resistência à Insulina/genética , MicroRNAs/genéticaRESUMO
Invited for the cover of this issue is the group of Tito Trindade and colleagues at the University of Aveiro. The image depicts dendritic magneto-plasmonic substrates for surface-enhanced Raman scattering (SERS) detection. Read the full text of the article at 10.1002/chem.202202382.
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Nanoestruturas , Análise Espectral Raman , Análise Espectral Raman/métodos , Nanoestruturas/químicaRESUMO
Chemical analyses in the field using surface-enhanced Raman scattering (SERS) protocols are expected to be part of several analytical procedures applied to water quality monitoring. To date, these endeavors have been supported by developments in SERS substrate nanofabrication, instrumentation portability, and the internet of things. Here, we report distinct chemical strategies for preparing magneto-plasmonic (Fe3 O4 : Au) colloids, which are relevant in the context of trace-level detection of water contaminants due to their inherent multifunctionality. The main objective of this research is to investigate the role of poly(amidoamine) dendrimers (PAMAMs) in the preparation of SERS substrates integrating both functionalities into single nanostructures. Three chemical routes were investigated to design magneto-plasmonic nanostructures that translate into different ways for assessing SERS detection by using distinct interfaces. Hence, a series of magneto-plasmonic colloids have been characterized and then assessed for their SERS activity by using a model pesticide (thiram) dissolved in aqueous samples.
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Nanopartículas Metálicas , Nanoestruturas , Análise Espectral Raman/métodos , Ouro/química , Nanopartículas Metálicas/química , Nanoestruturas/química , Tiram/análiseRESUMO
Human iPSC-derived self-organized cardiac tissues can be valuable for the development of platforms for disease modeling and drug screening, enhancing test accuracy and reducing pharmaceutical industry financial burden. However, current differentiation systems still rely on static culture conditions and specialized commercial microwells for aggregation, which hinders the full potential of hiPSC-derived cardiac tissues. Herein, we integrate cost-effective and reproducible manual aggregation of hiPSC-derived cardiac progenitors with Matrigel encapsulation and a dynamic culture to support hiPSC cardiac differentiation and self-organization. Manual aggregation at day 7 of cardiac differentiation resulted in 97% of beating aggregates with 78% of cTnT-positive cells. Matrigel encapsulation conjugated with a dynamic culture promoted cell migration and the creation of organized structures, with observed cell polarization and the creation of lumens. In addition, encapsulation increased buoyancy and decreased coalescence of the hiPSC-derived cardiac aggregates. Moreover, VEGF supplementation increased over two-fold the percentage of CD31-positive cells resulting in the emergence of microvessel-like structures. Thus, this study shows that the explored culture parameters support the self-organization of hiPSC-derived cardiac microtissues containing multiple cardiac cell types. Additional stimuli (e.g., BMP) in long-term scalable and fully automatized cultures can further potentiate highly structured and mature hiPSC-derived cardiac models, contributing to the development of reliable platforms for high-throughput drug screening and disease modeling.
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Células-Tronco Pluripotentes Induzidas , Miócitos Cardíacos , Humanos , Miócitos Cardíacos/metabolismo , Células Cultivadas , Análise Custo-Benefício , Colágeno/metabolismo , Diferenciação CelularRESUMO
This study investigated whether regulation of the renin-angiotensin system (RAS) by enalapril and/or aerobic exercise training (AET) causes browning of the subcutaneous white adipose tissue (sWAT). C57BL/6 mice were fed either a standard chow or a high-fat (HF) diet for 16 weeks. At Week 8, HF-fed animals were divided into sedentary (HF), enalapril (HF-E), AET (HF-T), and enalapril plus AET (HF-ET) groups. Subsequently, sWAT was extracted for morphometry, determination of RAS expression, and biomarkers of WAT browning. The HF group displayed adipocyte hypertrophy and induction of the classical RAS axis. Conversely, all interventions reduced adiposity and induced the counterregulatory RAS axis. However, only AET raised plasma irisin, increased peroxisome proliferator-activated receptor-γ coactivator-1α, and uncoupling protein-1 levels, and the expression of PR-domain containing 16 in sWAT. Therefore, we concluded that AET-induced sWAT browning was independent of the counterregulatory axis shifting of RAS in HF diet-induced obesity.
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Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/fisiopatologia , Adiposidade/efeitos dos fármacos , Enalapril/farmacologia , Condicionamento Físico Animal/fisiologia , Corrida/fisiologia , Gordura Subcutânea/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/fisiopatologia , Animais , Biomarcadores/metabolismo , Dieta Hiperlipídica/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Obesidade/fisiopatologia , Sistema Renina-Angiotensina/efeitos dos fármacos , Gordura Subcutânea/metabolismo , Gordura Subcutânea/fisiopatologiaRESUMO
In sepsis-induced acute kidney injury, kidney blood flow may increase despite decreased glomerular filtration. Normally, angiotensin-II reduces kidney blood flow to maintain filtration. We hypothesized that sepsis reduces angiotensin type-1 receptor (AT1R) expression to account for this observation and tested this hypothesis in a patient case-control study and studies in mice. Seventy-three mice underwent cecal ligation and puncture (a sepsis model) or sham operation. Additionally, 94 septic mice received losartan (selective AT1R antagonist), angiotensin II without or with losartan, or vehicle. Cumulative urine output, kidney blood flow, blood urea nitrogen, and creatinine were measured. AT1R expression was assessed using ELISA, qPCR, and immunofluorescence. A blinded pathologist evaluated tissue for ischemic injury. AT1R expression was compared in autopsy tissue from seven patients with sepsis to that of the non-involved portion of kidney from ten individuals with kidney cancer and three non-infected but critically ill patients. By six hours post ligation/puncture, kidney blood flow doubled, blood urea nitrogen rose, and urine output fell. Concurrently, AT1R expression significantly fell 2-fold in arterioles and the macula densa. Creatinine significantly rose by 24 hours and sham operation did not alter measurements. Losartan significantly exacerbated ligation/puncture-induced changes in kidney blood flow, blood urea nitrogen, creatinine, and urine output. There was no histologic evidence of cortical ischemia. Significantly, angiotensin II prevented changes in kidney blood flow, creatinine, and urine output compared to vehicle. Co-administering losartan with angiotensin-II reversed this protection. Relative to both controls, patients with sepsis had low AT1R expression in arterioles and macula densa. Thus, murine cecal ligation/puncture and clinical sepsis decrease renal AT1R expression. Angiotensin II prevents functional changes while AT1R-blockade exacerbates them independent of ischemia in mice.
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Injúria Renal Aguda , Sepse , Injúria Renal Aguda/etiologia , Angiotensina II , Animais , Estudos de Casos e Controles , Humanos , Losartan/farmacologia , Camundongos , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 2 de Angiotensina , Sepse/complicaçõesRESUMO
One of the health benefits of endurance exercise training (ET) is the stimulation of hematopoiesis. However, the mechanisms underlying ET-induced hematopoietic adaptations are understudied. N-Acetyl-Seryl-Aspartyl-Lysyl-Proline (Ac-SDKP) inhibits proliferation of early hematopoietic progenitor cells. The angiotensin I-converting enzyme (ACE) NH2-terminal promotes hematopoiesis by inhibiting the anti-hematopoietic effect of Ac-SDKP. Here we demonstrate for the first time the role of ACE NH2-terminal in ET-induced hematopoietic adaptations. Wistar rats were subjected to 10 weeks of moderate-(T1) and high-(T2) volume swimming-training. Although both protocols induced classical ET-associated adaptations, only T2 increased plasma ACE NH2-domain activity (by 40%, P=0.0003) and reduced Ac-SDKP levels (by 50%, P<0.0001). T2 increased the number of hematopoietic stem cells (HSCs; â¼200%, P=0.0008), early erythroid progenitor colonies (â¼300%, P<0.0001) and reticulocytes (â¼500%, P=0.0007), and reduced erythrocyte lifespan (â¼50%, P=0.022). Following, Wistar rats were subjected to T2 or T2 combined with ACE NH2-terminal inhibition (captopril (Cap) treatment: 10 mg.kg-1.day-1). T2 combined with ACE NH2-terminal inhibition prevented Ac-SDKP decrease and attenuated ET-induced hematopoietic adaptations. Altogether, our findings show that ET-induced hematopoiesis was at least partially associated with increased ACE NH2-terminal activity and reduction in the hematopoietic inhibitor Ac-SDKP.
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Treino Aeróbico , Hematopoese , Células-Tronco Hematopoéticas/enzimologia , Peptidil Dipeptidase A/metabolismo , Resistência Física , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Captopril/farmacologia , Feminino , Hematopoese/efeitos dos fármacos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Oligopeptídeos/metabolismo , Condicionamento Físico Animal , Domínios Proteicos , Ratos Wistar , Fatores de TempoRESUMO
Stroke is a leading cause of death and disability worldwide. The reasons for increased stroke burden in developing countries are inadequately controlled risk factors resulting from poor public awareness and inadequate infrastructure. Computed tomography and MRI are common neuroimaging modalities used to assess stroke with diffusion-weighted MRI, in particular, being the recommended choice for acute stroke imaging. However, access to these imaging modalities is primarily restricted to major cities and high-income groups. In the case of stroke, the time-window of treatment to limit the damage is of a few hours and needs a point-of-care diagnosis. A low-cost MR system typically achieved at the ultra-low- and very-low-field would meet the need for a geographically accessible and portable solution. We review studies focused on accessible stroke imaging and recent developments in MR methodologies, including hardware, to image at low fields. We hypothesize that in the absence of a formal, rapid stroke triaging system, the value of timely on-site delivery of the scanner to the stroke patient can be significant. To this end, we discuss multiple recent hardware and methods developments in the low-field regime. Our review suggests a compelling need to explore further the trade-offs between high signal, contrast, and accessibility at low fields in low-income communities. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 6.
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Imageamento por Ressonância Magnética , Acidente Vascular Cerebral , Imagem de Difusão por Ressonância Magnética , Humanos , Neuroimagem , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
Human-induced pluripotent stem cells (iPSCs) have great potential for disease modeling. However, generating iPSC-derived models to study brain diseases remains a challenge. In particular, the ability to recapitulate cerebellar development in vitro is still limited. We presented a reproducible and scalable production of cerebellar organoids by using the novel single-use Vertical-Wheel bioreactors, in which functional cerebellar neurons were obtained. Here, we evaluate the global gene expression profiles by RNA sequencing (RNA-seq) across cerebellar differentiation, demonstrating a faster cerebellar commitment in this novel dynamic differentiation protocol. Furthermore, transcriptomic profiles suggest a significant enrichment of extracellular matrix (ECM) in dynamic-derived cerebellar organoids, which can better mimic the neural microenvironment and support a consistent neuronal network. Thus, an efficient generation of organoids with cerebellar identity was achieved for the first time in a continuous process using a dynamic system without the need of organoids encapsulation in ECM-based hydrogels, allowing the possibility of large-scale production and application in high-throughput processes. The presence of factors that favors angiogenesis onset was also detected in dynamic conditions, which can enhance functional maturation of cerebellar organoids. We anticipate that large-scale production of cerebellar organoids may help developing models for drug screening, toxicological tests, and studying pathological pathways involved in cerebellar degeneration.
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Cerebelo/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Organoides/metabolismo , RNA-Seq , Cerebelo/citologia , Matriz Extracelular/metabolismo , Humanos , Hidrogéis/química , Células-Tronco Pluripotentes Induzidas/citologia , Organoides/citologiaRESUMO
This study describes a time-dependent self-assembly generation of new copper(II) coordination compounds from an aqueous-medium reaction mixture composed of copper(II) nitrate, H3bes biobuffer (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), ammonium hydroxide, and benzenecarboxylic acid, namely, 4-methoxybenzoic (Hfmba) or 4-chlorobenzoic (Hfcba) acid. Two products were isolated from each reaction, namely, 1D coordination polymers [Cu3(µ3-OH)2(µ-fmba)2(fmba)2(H2O)2]n (1) or [Cu2(µ-OH)2(µ-fcba)2]n (2) and discrete tetracopper(II) rings [Cu4(µ-Hbes)3(µ-H2bes)(µ-fmba)]·2H2O (3) or [Cu4(µ-Hbes)3(µ-H2bes)(µ-fcba)]·4H2O (4), respectively. These four compounds were obtained as microcrystalline air-stable solids and characterized by standard methods, including the single-crystal X-ray diffraction. The structures of 1 and 2 feature distinct types of metal-organic chains driven by the µ3- or µ-OH- ligands along with the µ-benzenecarboxylate linkers. The structures of 3 and 4 disclose the chairlike Cu4 rings assembled from four µ-bridging and chelating aminoalcoholate ligands along with µ-benzenecarboxylate moieties playing a core-stabilizing role. Catalytic activity of 1-4 was investigated in two model reactions, namely, (a) the mild oxidation of saturated hydrocarbons with hydrogen peroxide to form alcohols and ketones and (b) the mild carboxylation of alkanes with carbon monoxide, water, and peroxodisulfate to generate carboxylic acids. Cyclohexane and propane were used as model cyclic and gaseous alkanes, while the substrate scope also included cyclopentane, cycloheptane, and cyclooctane. Different reaction parameters were investigated, including an effect of the acid cocatalyst and various selectivity parameters. The obtained total product yields (up to 34% based on C3H8 or up to 47% based on C6H12) in the carboxylation of propane and cyclohexane are remarkable taking into account an inertness of these saturated hydrocarbons and low reaction temperatures (50-60 °C). Apart from notable catalytic activity, this study showcases a novel time-dependent synthetic strategy for the self-assembly of two different Cu(II) compounds from the same reaction mixture.
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Near-infrared spectroscopic (NIR) technique was used, for the first time, to predict volatile phenols content, namely guaiacol, 4-methyl-guaiacol, eugenol, syringol, 4-methyl-syringol and 4-allyl-syringol, of aged wine spirits (AWS). This study aimed to develop calibration models for the volatile phenol's quantification in AWS, by NIR, faster and without sample preparation. Partial least square regression (PLS-R) models were developed with NIR spectra in the near-IR region (12,500-4000 cm-1) and those obtained from GC-FID quantification after liquid-liquid extraction. In the PLS-R developed method, cross-validation with 50% of the samples along a validation test set with 50% of the remaining samples. The final calibration was performed with 100% of the data. PLS-R models with a good accuracy were obtained for guaiacol (r2 = 96.34; RPD = 5.23), 4-methyl-guaiacol (r2 = 96.1; RPD = 5.07), eugenol (r2 = 96.06; RPD = 5.04), syringol (r2 = 97.32; RPD = 6.11), 4-methyl-syringol (r2 = 95.79; RPD = 4.88) and 4-allyl-syringol (r2 = 95.97; RPD = 4.98). These results reveal that NIR is a valuable technique for the quality control of wine spirits and to predict the volatile phenols content, which contributes to the sensory quality of the spirit beverages.
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Vinho , Calibragem , Análise dos Mínimos Quadrados , Fenóis/análise , Espectroscopia de Luz Próxima ao Infravermelho , Vinho/análiseRESUMO
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the gene encoding the methyl-CpG-binding protein 2 (MeCP2). Among many different roles, MeCP2 has a high phenotypic impact during the different stages of brain development. Thus, it is essential to intensively investigate the function of MeCP2, and its regulated targets, to better understand the mechanisms of the disease and inspire the development of possible therapeutic strategies. Several animal models have greatly contributed to these studies, but more recently human pluripotent stem cells (hPSCs) have been providing a promising alternative for the study of RTT. The rapid evolution in the field of hPSC culture allowed first the development of 2D-based neuronal differentiation protocols, and more recently the generation of 3D human brain organoid models, a more complex approach that better recapitulates human neurodevelopment in vitro. Modeling RTT using these culture platforms, either with patient-specific human induced pluripotent stem cells (hiPSCs) or genetically-modified hPSCs, has certainly contributed to a better understanding of the onset of RTT and the disease phenotype, ultimately allowing the development of high throughput drugs screening tests for potential clinical translation. In this review, we first provide a brief summary of the main neurological features of RTT and the impact of MeCP2 mutations in the neuropathophysiology of this disease. Then, we provide a thorough revision of the more recent advances and future prospects of RTT modeling with human neural cells derived from hPSCs, obtained using both 2D and organoids culture systems, and its contribution for the current and future clinical trials for RTT.