929 research outputs found

    The relevance of α-KLOTHO to the central nervous system: Some key questions

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    α-Klotho is well described as an anti-aging protein, with critical roles in kidney function as a transmembrane co-receptor for FGF23, and as a soluble factor in serum. α-Klotho is also expressed in the choroid plexus, where it is released into the cerebrospinal fluid. Nonetheless, α-Klotho is also expressed in the brain parenchyma. Accumulating evidence indicates that this pool of α-Klotho, which we define as brain α-Klotho, may play important roles as a neuroprotective factor and in promoting myelination, thereby supporting healthy brain aging. Here we summarize what is known about brain α-Klotho before focusing on the outstanding scientific questions related to its function. We believe there is a need for in vitro studies designed to distinguish between brain α-Klotho and other pools of α-Klotho, and for a greater understanding of the basic function of soluble α-Klotho. The mechanism by which the human KL-VS variant affects cognition also requires further elucidation. To help address these questions we suggest some experimental approaches that other laboratories might consider. In short, we hope to stimulate fresh ideas and encourage new research approaches that will allow the importance of α-Klotho for the aging brain to become clear

    Preventable Cases of Oral Anticoagulant-Induced Bleeding: Data From the Spontaneous Reporting System

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    Background: Despite the risk of bleeding is a well-known adverse effect of oral anticoagulants, there is scarce evidence on the preventability of oral anticoagulant-induced bleedings. Therefore, we investigated the potential risk factors related to preventable cases of oral anticoagulant-induced bleedings. Methods: We performed a study using Individual Case Safety Reports (ICSRs) with an oral anticoagulant as suspected drug among those reported through the spontaneous reporting system of Campania Region from 1 July 2012 to 31 December 2017. The P-method was used for the preventability assessment of all cases of bleeding. Results: In total, 58 cases out of 253 (22.9%) were preventable, and the most reported suspected drug was an indirect oral anticoagulant (warfarin). Sixty-eight critical criteria for preventability were identified, all related to healthcare professionals' practices. The most detected risk factor related to healthcare professionals' practices was the labeled drug-drug interaction for both direct and indirect oral anticoagulants. Conclusion: Our findings describe the most reported risk factors for preventability of oral anticoagulant-induced bleedings. These factors may be useful for targeting interventions to improve pharmacovigilance activities in our regional territory and to reduce the burden of medication errors and inappropriate prescription

    Myocarditis and pericarditis in individuals exposed to the Ad26.COV2.S, BNT162b2 mRNA, or mRNA-1273 SARS-CoV-2 vaccines

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    IMPORTANCE: There is a high level of public and professional interest related to potential safety issues of the COVID-19 vaccines; however, no serious adverse cardiovascular events were reported in phase 3 randomized controlled trials of their safety and efficacy. Moreover, none of the case series from the United States (US) of these potential complications have been population-based.OBJECTIVES: To estimate the reporting rates of myocarditis and pericarditis in the US using the Vaccine Adverse Event Reporting System (VAERS), and to assess if these adverse events were disproportionally reported among the different COVID-19 vaccines.DESIGN SETTING AND PARTICIPANTS: All cases of myocarditis and pericarditis from VAERS reported up to July 28, 2021.EXPOSURE: Single-dose Ad26.COV2.S, BNT162b2 mRNA, or mRNA-1273 SARS-CoV-2 vaccinations.MAIN OUTCOMES AND MEASURES: Reporting rates were computed by dividing the total number of cases of myocarditis and pericarditis (combined) by the total number of vaccine doses administered. Disproportionality analyses were performed to evaluate disproportional reporting of myocarditis and pericarditis for the Ad26.COV2.S and mRNA-1273 vaccines vs. the BNT162b2 mRNA vaccine.RESULTS: By July 28, 2021, 1392, 699, and 68 cases of myocarditis or pericarditis had been reported out of 1.91, 1.38, and 1.33 million administered doses of the BNT162b2 mRNA, mRNA-1273, and Ad26.COV2.S COVID-19 vaccines, respectively. Median times to event were 3 days, 3 days, and 9 days for the BNT162b2 mRNA, mRNA-1273, and Ad26.COV2.S COVID-19 vaccines. The reporting rates for myocarditis or pericarditis were 0.00073 (95% confidence interval, 95% CI 0.00069-0.00077), 0.00051 (95% CI 0.00047-0.00055), and 0.00005 events per dose (95% CI 0.00004-0.00006) for the BNT162b2 mRNA, mRNA-1273, and Ad26.COV2.S COVID-19 vaccines, respectively. Myocarditis and pericarditis were disproportionally reported following the BNT162b2 mRNA vaccine when compared with the other vaccines, using both disproportionality measures.CONCLUSIONS AND RELEVANCE: We found reporting rates of myocarditis and pericarditis to be less than 0.1% after COVID-19 vaccination. Rates were highest for the BNT162b2 mRNA vaccine, followed by the mRNA-1273 and Ad26.COV2.S, respectively. However, the reporting rates of myocarditis and pericarditis secondary to vaccination remains less common than those seen for SARS-CoV-2 infection.</p

    Stress-induced neuroinflammation: mechanisms and new pharmacological targets

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    Stress is triggered by numerous unexpected environmental, social or pathological stimuli occurring during the life of animals, including humans, which determine changes in all of their systems. Although acute stress is essential for survival, chronic, long-lasting stress can be detrimental. In this review, we present data supporting the hypothesis that stress-related events are characterized by modifications of oxidative/nitrosative pathways in the brain in response to the activation of inflammatory mediators. Recent findings indicate a key role for nitric oxide (NO) and an excess of pro-oxidants in various brain areas as responsible for both neuronal functional impairment and structural damage. Similarly, cyclooxygenase-2 (COX-2), another known source of oxidants, may account for stress-induced brain damage. Interestingly, some of the COX-2-derived mediators, such as the prostaglandin 15d-PGJ2 and its peroxisome proliferator-activated nuclear receptor PPAR&#947;, are activated in the brain in response to stress, constituting a possible endogenous anti-inflammatory mechanism of defense against excessive inflammation. The stress-induced activation of both biochemical pathways depends on the activation of the N-methyl-D-aspartate (NMDA) glutamate receptor and on the activation of the transcription factor nuclear factor kappa B (NF&#954;B). In the case of inducible NO synthase (iNOS), release of the cytokine TNF-&#945; also accounts for its expression. Different pharmacological strategies directed towards different sites in iNOS or COX-2 pathways have been shown to be neuroprotective in stress-induced brain damage: NMDA receptor blockers, inhibitors of TNF-&#945; activation and release, inhibitors of NF&#954;B, specific inhibitors of iNOS and COX-2 activities and PPAR&#947; agonists. This article reviews recent contributions to this area addressing possible new pharmacological targets for the treatment of stress-induced neuropsychiatric disorders.Spanish Ministries of HealthEducationFAPESPCNP

    Atividade da óxido nítrico sintase em plaquetas humanas: um método otimizado

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    A análise cinética da atividade da óxido nítrico sintase (NOS) plaquetária foi avaliada pela conversão de [³H]-arginina em [³H]-citrulina em plaquetas humanas frescas não estimuladas. A atividade da NOS foi detectada na fração citosólica e na membrana, além de ser dependente de Ca2+-calmodulina, que é uma característica da NOS endotelial (eNOS). A omissão de NADPH levou à diminuição da atividade da NOS dependente da dose causando redução de 85,2% da atividade enzimática. A cinética variou de acordo com as concentrações de proteína e de arginina, sendo que as melhores leituras foram obtidas com 80 µg de proteína, 120 nM de arginina em 0,5 µCi de ³H arginina, em 60 minutos de incubação. A atividade da NOS na ausência de FAD (flavina adenina dinucleotídeo), FMN (flavina mononucleotídeo) e BH4 (tetrahidrobiopterina) foi de apenas 2,8% da atividade medida na presença destes três cofatores. A atividade da enzima foi completamente inibida pelo L-NAME (1 mM; 98,1 %), EGTA (5 mM; 98,8 %) e adição de trifluoperazina (TFP), nas concentrações de 200 µM e 500 µM, inibiu a atividade da enzima em 73,2% e 83,8 %, respectivamente. Em condições basais, o Km da NOS para Larginina foi de 0,84 ± 0,08 µM e o valor de Vmax foi de 0,122 ± 0,025 pmol.mg-1.min-1. A atividade média da NOS plaquetária humana foi de 0,020 ± 0,010 pmol.mg-1.min-1. Os resultados indicam que a eNOS em plaquetas humanas pode ser avaliada pelo método da conversão de [³H]-arginina em [³H]-citrulina, que em condições otimizadas, fornece resultados reprodutíveis e precisos com ótima sensibilidade para experimentos clínicos envolvendo doenças neurológicas e psiquiátricas.We investigated the kinetic analysis of human platelet Nitric Oxide Synthase (NOS) activity by the rate of conversion of [³H] arginine to [³H]-citrulline in unstimulated fresh platelets. NOS activity was present in the membrane fraction and cytosol, and was Ca2+- and calmodulin dependent which is a characteristic of endothelial NOS. NOS activity was also dependent of NADPH since the omission of this cofactor induced an important decrease (85,2%) in the enzyme activity. The kinetic varied with protein and arginine concentration but optimum concentrations were found up to 60 minutes, and up to 80 µg of protein at 120 nM of arginine and 0.5 µCi of ³H-arginine. NOS activity in the absence of FAD (flavin adenine dinucleotide), FMN (flavin mononucleotide) and BH4 (tetrahydrobiopterin) was only 2.8% of the activity measured in the presence of these three cofactors. The enzyme activity was completely inhibited by L-NAME (1 mM) (98.1 %) and EGTA (5 mM) (98.8 %). Trifluoperazine (TFP) caused 73.2% inhibition of the enzyme activity at 200 µM and 83.8 % at 500 µM. Under basal conditions, NOS Km for L-arginine was 0.84 ± 0.08 µM and mean Vmax values were 0.122 ± 0.025 pmol.mg-1.min-1. Mean human NOS platelet activity was 0.020 ± 0.010 pmol.mg-1.min-1. Results indicate that the eNOS in human platelet can be evaluated by conversion of [³H]-arginine to [³H]citrulline in an optimized method, which provide reproducible and accurate results with good sensitivity to clinical experiments involving neurological and psychiatric diseases

    The Role of Renin-Angiotensin-Aldosterone System in the Heart and Lung: Focus on COVID-19

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    The renin-angiotensin-aldosterone system (RAAS) firstly considered as a cardiovascular circulating hormonal system, it is now accepted as a local tissue system that works synergistically or independently with the circulating one. Evidence states that tissue RAAS locally generates mediators with regulatory homeostatic functions, thus contributing, at some extent, to organ dysfunction or disease. Specifically, RAAS can be divided into the traditional RAAS pathway (or classic RAAS) mediated by angiotensin II (AII), and the non-classic RAAS pathway mediated by angiotensin 1–7. Both pathways operate in the heart and lung. In the heart, the classic RAAS plays a role in both hemodynamics and tissue remodeling associated with cardiomyocyte and endothelial dysfunction, leading to progressive functional impairment. Moreover, the local classic RAAS may predispose the onset of atrial fibrillation through different biological mechanisms involving inflammation, accumulation of epicardial adipose tissue, and electrical cardiac remodeling. In the lung, the classic RAAS regulates cell proliferation, immune-inflammatory response, hypoxia, and angiogenesis, contributing to lung injury and different pulmonary diseases (including COVID-19). Instead, the local non-classic RAAS counteracts the classic RAAS effects exerting a protective action on both heart and lung. Moreover, the non-classic RAAS, through the angiotensin-converting enzyme 2 (ACE2), mediates the entry of the etiological agent of COVID-19 (SARS-CoV-2) into cells. This may cause a reduction in ACE2 and an imbalance between angiotensins in favor of AII that may be responsible for the lung and heart damage. Drugs blocking the classic RAAS (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers) are well known to exert a cardiovascular benefit. They are recently under evaluation for COVID-19 for their ability to block AII-induced lung injury altogether with drugs stimulating the non-classic RAAS. Herein, we discuss the available evidence on the role of RAAS in the heart and lung, summarizing all clinical data related to the use of drugs acting either by blocking the classic RAAS or stimulating the non-classic RAAS

    The New Paradigms in Clinical Research: From Early Access Programs to the Novel Therapeutic Approaches for Unmet Medical Needs.

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    Despite several innovative medicines gaining worldwide approval in recent years, there are still therapeutic areas for which unsatisfied therapeutic needs persist. For example, high unmet clinical need was observed in patients diagnosed with type 2 diabetes mellitus and hemophilia, as well as in specific age groups, such as the pediatric population. Given the urgent need to improve the therapy of clinical conditions for which unmet clinical need is established, clinical testing, and approval of new medicines are increasingly being carried out through accelerated authorization procedures. Starting from 1992, the Food and Drug Administration and the European Medicines Agency have supported the so-called Early Access Programs (EAPs). Such procedures, which can be based on incomplete clinical data, allow an accelerated marketing authorization for innovative medicines. The growth in pharmaceutical research has also resulted in the development of novel therapeutic approaches, such as biotech drugs and advanced therapy medicinal products, including new monoclonal antibodies for the treatment of asthma, antisense oligonucleotides for the treatment of Duchenne muscular dystrophy and spinal muscular atrophy, and new anticancer drugs that act on genetic biomarkers rather than any specific type of cancer. Even though EAPs and novel therapeutic approaches have brought huge benefits for public health, their implementation is limited by several challenges, including the high risk of safety-related label changes for medicines authorized through the accelerated procedure, the high costs, and the reimbursement and access concerns. In this context, regulatory agencies should provide the best conditions for the implementation of the described new tools

    Relevance of Na,K-ATPase to local extracellular potassium homeostasis and modulation of synaptic transmission

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    AbstractThe ion gradients generated by the Na,K-ATPase are essential for Na+-coupled transport systems, osmoregulation and restoration of ion concentrations in excitable tissues. Indirectly, the sodium pump controls intracellular Ca2+ concentration through the Na/Ca exchanger. In the nervous system various neurotransmitters can modulate Na,K-ATPase activity. The great diversity of Na,K-ATPase subunit isoforms, their complex spatial and temporal regulation of expression and their cellular localisation imply a functional role of the sodium pump in different regulatory pathways. Among these, potassium homeostasis and modulation of synaptic transmission are discussed here
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