Acute kidney injury in pediatrics: an overview focusing on pathophysiology.

Acute kidney injury (AKI) is defined as an abrupt decline in glomerular filtration rate, with increased serum creatinine and nitrogenous waste products due to several possible etiologies. Incidence in the pediatric population is estimated to be 3.9 per 1,000 hospitalizations, and prevalence among children admitted to intensive care units is 26.9%. Despite being a condition with important incidence and morbimortality, further evidence on pathophysiology and management among the pediatric population is still lacking. This narrative review aimed to summarize and discuss current data on AKI pathophysiology in the pediatric population, considering all the physiological particularities of this age range and common etiologies. Additionally, we reported current diagnostic tools, novel biomarkers, and newly proposed medications that have been studied with the aim of early diagnosis and appropriate treatment of AKI in the future.

2020 update on the renin-angiotensin-aldosterone system in pediatric kidney disease and its interactions with coronavirus.

The last decade was crucial for our understanding of the renin-angiotensin-aldosterone system (RAAS) as a two-axis, counter-regulatory system, divided into the classical axis, formed by angiotensin-converting enzyme (ACE), angiotensin II (Ang II), and the angiotensin type 1 receptor (AT1R), and the alternative axis comprising angiotensin-converting enzyme 2 (ACE2), angiotensin-(1-7) (Ang-(1-7)), and the Mas receptor. Breakthrough discoveries also took place, with other RAAS endopeptides being described, including alamandine and angiotensin A. In this review, we characterize the two RAAS axes and the role of their components in pediatric kidney diseases, including childhood hypertension (HTN), pediatric glomerular diseases, congenital abnormalities of the kidney and urinary tract (CAKUT), and chronic kidney disease (CKD). We also present recent findings on potential interactions between the novel coronavirus, SARS-CoV-2, and components of the RAAS, as well as potential implications of coronavirus disease 2019 (COVID-19) for pediatric kidney diseases.

COVID-19 pandemic and the answer of science: a year in review.

The world is looking forward to a prompt response by the scientific community in order to overcome the first pandemic of the 21st century. This study aimed to provide an overview of scientific output on COVID-19 during its first year. We assembled information regarding 60,830 articles related to COVID-19 indexed in the WoS database from January 24 to December 13, 2020. Only 4 countries accounted for about 60% of the articles (USA, China, Italy, and England) and 12 countries accounted for about 95% of the world scientific output on COVID-19 (USA, China, Italy, England, India, Canada, Germany, Spain, Australia, Brazil, Iran, and Turkey). 25 research centers around the world contributed with more than 500 papers on COVID-19. Papers were scattered throughout 6,133 journals, with 12 journals with > 250 articles. 20 articles (0.03%) have already received more than the 1,000 citations. The response of the scientific endeavor to this acute global public health emergency has been fast and robust. The overview provided by the analysis of the scientific response to the pandemic may contribute to further studies aiming to evaluate the impact and changes in the scientific endeavor for the next years in light of the forthcoming new world framework.

Covid-19: the renin-angiotensin system imbalance hypothesis.

The emergency of SARS-CoV-2 in China started a novel challenge to the scientific community. As the virus turns pandemic, scientists try to map the cellular mechanisms and pathways of SARS-CoV-2 related to the pathogenesis of Coronavirus Disease 2019 (Covid-19). After transmembrane angiotensin-converting enzyme 2 (ACE2) has been found to be SARS-CoV-2 receptor, we hypothesized an immune-hematological mechanism for Covid-19 based on renin-angiotensin system (RAS) imbalance to explain clinical, laboratory and imaging findings on disease course. We believe that exaggerated activation of ACE/Angiotensin II (Ang II)/Angiotensin Type 1 (AT1) receptor RAS axis in line with reduction of ACE2/Angiotensin-(1-7)/Mas receptor may exert a pivotal role in the pathogenesis of Covid-19. In this perspective, we discuss potential mechanisms and evidence on this hypothesis.

ACE2 activator diminazene aceturate exerts renoprotective effects in gentamicin-induced acute renal injury in rats.

Acute Kidney Injury (AKI) comprises a rapidly developed renal failure and is associated with high mortality rates. The Renin-Angiotensin System (RAS) plays a pivotal role in AKI, as the over-active RAS axis exerts major deleterious effects in disease progression. In this sense, the conversion of Angiotensin II (Ang II) into Angiotensin-(1-7) (Ang-(1-7)) by the Angiotensin-converting enzyme 2 (ACE2) is of utmost importance to prevent worse clinical outcomes. Previous studies reported the beneficial effects of oral diminazene aceturate (DIZE) administration, an ACE2 activator, in renal diseases models. In the present study, we aimed to evaluate the therapeutic effects of DIZE administration in experimental AKI induced by gentamicin (GM) in rats. Our findings showed that treatment with DIZE improved renal function and tissue damage by increasing Ang-(1-7) and ACE2 activity, and reducing TNF-α. These results corroborate with a raising potential of ACE2 activation as a strategy for treating AKI.

Nephrogenesis, Renal Function, and Biomarkers in Preterm Newborns.

BACKGROUND: The survival of premature newborns increased in the last decades due to advances in neonatal care. The physiology of this group is still under investigation, once the incomplete organogenesis entails functional particularities that are not yet clarified by current clinical knowledge. The immature kidneys are especially susceptible to acute injury with potential long-term impacts. Current diagnostic parameters of acute kidney injury are limited among the preterm population. The commonly used serum creatinine protein constitutes a poor biomarker to predict early lesions as it is susceptible to several factors, including muscle mass and gestational age. OBJECTIVE: The present review explores the evidence on nephrogenesis, renal function, and acute kidney injury in neonatology, as well as studies on renal function biomarkers and their potential application for diagnosis, follow-up, and prognosis in preterm newborns. RESULTS: Premature newborns reach full-term gestational age with reduced number and quality of nephrons. Consequently, the glomerular filtration rate and tubular function become impaired and are proportional to the gestational age. Despite having a high incidence among the pediatric population, acute kidney injury is still underdiagnosed and poorly managed due to the absence of proper, sensible, and non-invasive biomarkers. Although cystatin C, NGAL, and KIM-1, are promising urinary markers, current literature remains inconsistent. CONCLUSION: Further research is needed to properly identify and standardize sensible and specific urinary biomarkers to better assess kidney function in preterm newborns.

Renin-Angiotensin System in Central Nervous System Diseases and its Interaction with COVID-19.

BACKGROUND: The Renin-Angiotensin System (RAS) comprises a complex molecular cascade with two counter-regulatory axes, the classical and the alternative. Angiotensin II and Angiotensin-(1-7), the main peptides of the RAS, exert opposite effects in multiple organs and systems, including the cardiovascular, renal, pulmonary, and immune systems. Strong evidence supports the hypothesis of a local RAS in the Central Nervous System (CNS) and its modulatory roles in neuroendocrinology and neurotransmission. OBJECTIVE: In this narrative review, we provide a comprehensive approach to experimental and clinical data regarding RAS molecule expression and their possible roles in the physiology and physiopathology of CNS diseases. METHODS: This non-systematic review summarizes evidence on RAS implications in CNS diseases and their possible relationships with COVID-19. RESULTS: We divided the possible RAS mechanisms in distinct conditions during the lifespan, approaching from congenital infections to neurodegenerative alterations, passing through mood disorders and cerebrovascular diseases. We also gathered current evidence about the possible effects of RAS in Covid-19, particularly in cases with neurological manifestations. CONCLUSION: Although there are limitations and controversies, the analysis of RAS mechanisms in the CNS certainly represents an interesting field of research. However, further investigation is necessary to support the noteworthy interactions and provide a better comprehension of the cross-talk between RAS and the CNS. Investigations in this research field may shed light on the novel therapeutic targets.

Insights on SARS-CoV-2 Molecular Interactions With the Renin-Angiotensin System.

The emergence of SARS-CoV-2/human/Wuhan/X1/2019, a virus belonging to the species Severe acute respiratory syndrome-related coronavirus, and the recognition of Coronavirus Disease 2019 (COVID-19) as a pandemic have highly increased the scientific research regarding the pathogenesis of COVID-19. The Renin Angiotensin System (RAS) seems to be involved in COVID-19 natural course, since studies suggest the membrane-bound Angiotensin-converting enzyme 2 (ACE2) works as SARS-CoV-2 cellular receptor. Besides the efforts of the scientific community to understand the virus' molecular interactions with human cells, few studies summarize what has been so far discovered about SARS-CoV-2 signaling mechanisms and its interactions with RAS molecules. This review aims to discuss possible SARS-CoV-2 intracellular signaling pathways, cell entry mechanism and the possible consequences of the interaction with RAS components, including Angiotensin II (Ang II), Angiotensin-(1-7) [Ang-(1-7)], Angiotensin-converting enzyme (ACE), ACE2, Angiotensin II receptor type-1 (AT1), and Mas Receptor. We also discuss ongoing clinical trials and treatment based on RAS cascade intervention. Data were obtained independently by the two authors who carried out a search in the PubMed, Embase, LILACS, Cochrane, Scopus, SciELO and the National Institute of Health databases using Medical Subject Heading terms as "SARS-CoV-2," "COVID-19," "Renin Angiotensin System," "ACE2," "Angiotensin II," "Angiotensin-(1-7)," and "AT1 receptor." Similarly to other members of Coronaviridae family, the molecular interactions between the pathogen and the membrane-bound ACE2 are based on the cleavage of the spike glycoprotein (S) in two subunits. Following the binding of the S1 receptor-binding domain (RBD) to ACE2, transmembrane protease/serine subfamily 2 (TMPRSS2) cleaves the S2 domain to facilitate membrane fusion. It is very likely that SARS-CoV-2 cell entry results in downregulation of membrane-bound ACE2, an enzyme that converts Ang II into Ang-(1-7). This mechanism can result in lung injury and vasoconstriction. In addition, Ang II activates pro-inflammatory cascades when binding to the AT1 Receptor. On the other hand, Ang-(1-7) promotes anti-inflammatory effects through its interactions with the Mas Receptor. These molecules might be possible therapeutic targets for treating COVID-19. Thus, the understanding of SARS-CoV-2 intracellular pathways and interactions with the RAS may clarify COVID-19 physiopathology and open perspectives for new treatments and strategies.

Perfil e impacto dos bolsistas de produtividade em pesquisa do CNPq da Faculdade de Medicina da UFMG / Profile and impact of CNPq research productivity fellows at the Faculty of Medicine of UFMG

INTRODUÇÃO: Os programas de iniciação científica e pós-graduação são um instrumento essencial na formação de recursos humanos e na perpetuação da produção científica nacional. O papel dos professores pesquisadores no adequado desenvolvimento científico dos estudantes de graduação e pós-graduação tem sido continuamente reafirmado em diversas pesquisas sobre a qualidade do ensino superior brasileiro, apesar da contínua desvalorização das universidades públicas no país. Avaliar a carreira e o perfil dos bolsistas de produtividade em pesquisa pode fornecer elementos em relação ao impacto desses profissionais no ensino, na pesquisa e na internacionalização das universidades. OBJETIVO: Caracterizar o perfil profissional e a produção científica dos bolsistas do Programa de Produtividade em Pesquisa da Faculdade de Medicina da Universidade Federal de Minas Gerais. MÉTODOS: Estudo descritivo baseado na análise de dados públicos disponíveis na Plataforma Lattes. Os bolsistas de produtividade em pesquisa foram apurados com base nos resultados dos editais de 2013, 2016 e 2019. RESULTADOS: A análise das variáveis evidenciou diminuição do número de docentes bolsistas da instituição, que passou de 34 para 29. Observamos um número significativamente maior de projetos financiados por profissionais do sexo masculino quando comparados às pesquisadoras (p=0,03) e uma forte correlação entre os anos de doutorado e o número de doutores orientados que atualmente se dedicam à pesquisa. CONCLUSÃO: Professores pesquisadores exercem impacto direto na formação de recursos humanos qualificados e na formação de recursos humanos qualificados e na internacionalização das universidades públicas.

INTRODUCTION: Mentoring through scientific initiation and post-graduate programs are an essential instrument on the formation of human resources and the perpetuation of national scientific production. The role of research professors in the proper scientific development of graduate and post-graduate medical students has been continuously reaffirmed in several surveys on the quality of Brazilian superior education, despite the continuous desvalorization of higher education in the country. Determine the career and profile of research productivity fellows could measure the impact of these professionals in teaching, researching and internationalization of our university. OBJECTIVE: To characterize the professional profile and scientific production of the Productivity in Research Program fellows from the Faculty of Medicine of the Federal University of Minas Gerais. METHODS: This descriptive study is based on the analysis of public data available at Lattes Platform. Research productivity fellows were determined based on the results of the 2013, 2016 and 2019 calls for tenders. RESULTS: Analysis of the variables showed a decrease in the number of professors with scholarships at the institution, which went from 34 to 29. We observed a significantly higher number of funded projects of male professionals when compared to female researchers (p=0.03) and a strong correlation between years of doctorate degree and the number of mentored doctors currently dedicating to research. CONCLUSION: Experient research professors exert direct impact on the formation of qualified human resources and the internationalization of the federal university.