Federal University of São Paulo

About: Federal University of São Paulo is a education organization based out in São Paulo, Brazil. It is known for research contribution in the topics: Population & Transplantation. The organization has 27971 authors who have published 49365 publications receiving 935536 citations. The organization is also known as: Universidade Federal de São Paulo & Universidade Federal de Sao Paulo.

COVID-19: angiotensin-converting enzyme 2 (ACE2) expression and tissue susceptibility to SARS-CoV-2 infection.

Abstract: COVID-19 pandemic is caused by the novel coronavirus SARS-CoV-2. Angiotensin-converting enzyme 2 (ACE2) is not only an enzyme but also a functional receptor on cell surfaces through which SARS-CoV-2 enters the host cells and is highly expressed in the heart, kidneys, and lungs and shed into the plasma. ACE2 is a key regulator of the renin-angiotensin-aldosterone system (RAAS). SARS-CoV-2 causes ACE/ACE2 balance disruption and RAAS activation, which leads ultimately to COVID-19 progression, especially in patients with comorbidities, such as hypertension, diabetes mellitus, and cardiovascular disease. Therefore, ACE2 expression may have paradoxical effects, aiding SARS-CoV-2 pathogenicity, yet conversely limiting viral infection. This article reviews the existing literature and knowledge of ACE2 in COVID-19 setting and focuses on its pathophysiologic involvement in disease progression, clinical outcomes, and therapeutic potential.

Clinical Expression of Leber Hereditary Optic Neuropathy Is Affected by the Mitochondrial DNA–Haplogroup Background

Abstract: Leber hereditary optic neuropathy (LHON) is due primarily to one of three common point mutations of mitochondrial DNA (mtDNA), but the incomplete penetrance implicates additional genetic or environmental factors in the pathophysiology of the disorder. Both the 11778G→A and 14484T→C LHON mutations are preferentially found on a specific mtDNA genetic background, but 3460G→A is not. However, there is no clear evidence that any background influences clinical penetrance in any of these mutations. By studying 3,613 subjects from 159 LHON-affected pedigrees, we show that the risk of visual failure is greater when the 11778G→A or 14484T→C mutations are present in specific subgroups of haplogroup J (J2 for 11778G→A and J1 for 14484T→C) and when the 3460G→A mutation is present in haplogroup K. By contrast, the risk of visual failure is significantly less when 11778G→A occurs in haplogroup H. Substitutions on MTCYB provide an explanation for these findings, which demonstrate that common genetic variants have a marked effect on the expression of an ostensibly monogenic mtDNA disorder.

Technical challenges of working with extracellular vesicles

Abstract: Extracellular Vesicles (EVs) are gaining interest as central players in liquid biopsies, with potential applications in diagnosis, prognosis and therapeutic guidance in most pathological conditions. These nanosized particles transmit signals determined by their protein, lipid, nucleic acid and sugar content, and the unique molecular pattern of EVs dictates the type of signal to be transmitted to recipient cells. However, their small sizes and the limited quantities that can usually be obtained from patient-derived samples pose a number of challenges to their isolation, study and characterization. These challenges and some possible options to overcome them are discussed in this review.

Contemporary activity of colistin and polymyxin B against a worldwide collection of Gram-negative pathogens: results from the SENTRY Antimicrobial Surveillance Program (2006–09)

Abstract: OBJECTIVES: To comparatively evaluate the antimicrobial activities of colistin and polymyxin B with those of other antimicrobials against a worldwide collection of 40 625 Gram-negative bacilli. METHODS: Antimicrobial susceptibility testing was performed and interpreted using the CLSI broth microdilution method except for colistin against Enterobacteriaceae. RESULTS: The polymyxins showed potent in vitro activities (MIC₉₀, ≤ 0.5-1 mg/L) against this large collection of clinical isolates, with very low resistance rates (< 0.1%-1.5%). Resistance to the polymyxins remained stable among organisms tested except for Klebsiella spp. isolates collected from the Asia-Pacific and Latin American regions, where a trend towards greater resistance was observed (P ≤ 0.05). In addition, an important reduction in imipenem susceptibility among Acinetobacter spp. and Klebsiella spp. was demonstrated in most geographical regions. CONCLUSIONS: Although the polymyxins showed excellent in vitro activity against the vast majority of Gram-negative bacilli evaluated, a trend to greater resistance was observed in the Asia-Pacific and Latin American regions. Therefore, the clinical use of polymyxins must be cautious and surveillance monitored.