14 research outputs found
Epidemia sem fronteiras: Acção global, políticas públicas e o trajecto da luta contra a Sida em Portugal
De forma ainda mais acentuada do que aconteceu em muitos outros países, Portugal demorou demasiado tempo a agir e a implementar respostas pró-activas, selectivas, integradas e socialmente envolventes na abordagem à infecção pelo VIH/sida. Neste texto começamos por fazer uma breve arqueologia da criação de um quadro estrutural global de luta contra a infecção. De seguida debatemos o atraso com que foram implementadas no nosso país, apesar das orientações internacionais, políticas verdadeiramente sustentadas e eficazes de prevenção, monitorização, acompanhamento e tratamento da epidemia e, por outro lado, a permanência de legislação e orientações institucionais nefastas à sua prevenção e gestão ou, noutros casos ainda mais frequentes, a não operacionalização de quadros legislativos manifestamente adequados.Abstract:Even more so than in many other countries, Portugal took too long to act and implement pro-active, selective, integrated and socially engaging responses in the approach to the HIV/AIDS infection. In this paper, we begin by presenting a brief structure for the creation of a global structural framework of the fight against the infection. Afterwards, we will discuss the delay with which these measures were implement in our country, despite the international guidelines, truly sustained and efficient policies of prevention, monitoring, follow-up and treatment of the epidemic. On the other hand, we also analyse the permanence of legislation and institutional guidelines harmful to its prevention and management or, in other more frequent cases, the non-implementation of more appropriate legislative frameworks
Fluorine Atoms on C6H5-Corrole Affect the Interaction with Mpro and PLpro Proteases of SARS-CoV-2: Molecular Docking and 2D-QSAR Approaches
The chymotrypsin-like cysteine protease (3CLpro, also known as main protease—Mpro) and papain-like protease (PLpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been used as the main targets for screening potential synthetic inhibitors for posterior in vitro evaluation of the most promising compounds. In this sense, the present work reports for the first time the evaluation of the interaction between Mpro/PLpro with a series of 17 porphyrin analogues-corrole (C1), meso-aryl-corrole (C2), and 15 fluorinated-meso-aryl-corrole derivatives (C3–C17) via molecular docking calculations. The impact of fluorine atoms on meso-aryl-corrole structure was also evaluated in terms of binding affinity and physical-chemical properties by two-dimensional quantitative structure–activity relationship (2D-QSAR). The presence of phenyl moieties increased the binding capacity of corrole for both proteases and depending on the position of fluorine atoms might impact positively or negatively the binding capacity. For Mpro the para-fluorine atoms might decrease drastically the binding capacity, while for PLpro there was a certain increase in the binding affinity of fluorinated-corroles with the increase of fluorine atoms into meso-aryl-corrole structure mainly from tri-fluorinated insertions. The 2D-QSAR models indicated two separated regions of higher and lower affinity for Mpro:C1–C17 based on dual electronic parameters (σI and σR), as well as one model was obtained with a correlation between the docking score value of Mpro:C2–C17 and the corresponding 13C nuclear magnetic resonance (NMR) chemical shifts of the sp2 carbon atoms (δC-1 and δC-2) of C2–C17. Overall, the fluorinated-meso-aryl-corrole derivatives showed favorable in silico parameters as potential synthetic compounds for future in vitro assays on the inhibition of SARS-CoV-2 replication
Fatty acid profile and meat quality of young bulls fed ground soybean or ground cottonseed and vitamin E
The objective of this study was to evaluate the fatty acid profile and qualitative characteristics of meat from feedlot young bulls fed ground soybean or ground cottonseed, with or without supplementation of vitamin E. A total of 40 Red Norte young bulls, with an initial average age of 20 months, and an initial average BW of 339 +/- 15 kg, were allotted in a completely randomized design using a 2 x 2 factorial arrangement, with two oilseeds, and daily supplementation or not of 2500 IU of vitamin E. The experimental period was for 84 days, which was preceded by an adaptation period of 28 days. The treatments were ground soybean (SB), ground soybean plus vitamin E (SBE), ground cottonseed (CS) and ground cottonseed plus vitamin E (CSE). The percentage of cottonseed and soybean in the diets (dry matter basis) was 24% and 20%, respectively. Diets were isonitrogenous (13% CP) and presented similar amount of ether extract (6.5%). The animals were slaughtered at average live weight of 464 +/- 15 kg, and samples were taken from the longissimus dorsi muscle for the measurement of fatty acid concentration and the evaluation of lipid oxidation and color of the beef. Before fatty acid extraction, muscle tissue and subcutaneous fat of the longissimus dorsi were separated to analyze fatty acid profile in both tissues. Supplementation of vitamin E did not affect fatty acid concentration, lipid oxidation and color (P > 0.05). Subcutaneous fat from animals fed CS diet had greater C12: 0, C16: 0 and C18: 0 contents (P < 0.03). In addition, CS diets reduced the C18: 1 and C18: 2 cis-9, trans-11 contents in subcutaneous fat (P < 0.05). The muscle from animals fed CS tended to higher C16: 0 and C18: 0 contents (P < 0.11), and decreased C18: 1, C18: 2 cis-9, trans-11 and C18: 3 contents (P < 0.05) compared with SB. The Delta(9)-desaturase index was greater in muscle from animals fed SB (P < 0.01). At 42 days of age, meat from cattle fed SB had a greater lipid oxidation rate (P < 0.05). Meat from animals fed SB diets had less lightness and redness indices than meat from animals fed CS diets after 14 days of age. In conclusion, the addition of ground cottonseed in the finishing diets did increase the saturated fatty acid content of the longissimus dorsi. However, animals fed cottonseed exhibited greater lightness and redness of beef. In this study, the addition of vitamin E did not affect qualitative characteristics of meat
Commercially Available Flavonols Are Better SARS-CoV-2 Inhibitors than Isoflavone and Flavones
Despite the fast development of vaccines, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still circulating and generating variants of concern (VoC) that escape the humoral immune response. In this context, the search for anti-SARS-CoV-2 compounds is still essential. A class of natural polyphenols known as flavonoids, frequently available in fruits and vegetables, is widely explored in the treatment of different diseases and used as a scaffold for the design of novel drugs. Therefore, herein we evaluate seven flavonoids divided into three subclasses, isoflavone (genistein), flavone (apigenin and luteolin) and flavonol (fisetin, kaempferol, myricetin, and quercetin), for COVID-19 treatment using cell-based assays and in silico calculations validated with experimental enzymatic data. The flavonols were better SARS-CoV-2 inhibitors than isoflavone and flavones. The increasing number of hydroxyl groups in ring B of the flavonols kaempferol, quercetin, and myricetin decreased the 50% effective concentration (EC50) value due to their impact on the orientation of the compounds inside the target. Myricetin and fisetin appear to be preferred candidates; they are both anti-inflammatory (decreasing TNF-α levels) and inhibit SARS-CoV-2 mainly by targeting the processability of the main protease (Mpro) in a non-competitive manner, with a potency comparable to the repurposed drug atazanavir. However, fisetin and myricetin might also be considered hits that are amenable to synthetic modification to improve their anti-SARS-CoV-2 profile by inhibiting not only Mpro, but also the 3′–5′ exonuclease (ExoN)
Atazanavir Is a Competitive Inhibitor of SARS-CoV-2 Mpro, Impairing Variants Replication In Vitro and In Vivo
Atazanavir (ATV) has already been considered as a potential repurposing drug to 2019 coronavirus disease (COVID-19); however, there are controversial reports on its mechanism of action and effectiveness as anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Through the pre-clinical chain of experiments: enzymatic, molecular docking, cell-based and in vivo assays, it is demonstrated here that both SARS-CoV-2 B.1 lineage and variant of concern gamma are susceptible to this antiretroviral. Enzymatic assays and molecular docking calculations showed that SARS-CoV-2 main protease (Mpro) was inhibited by ATV, with Morrison’s inhibitory constant (Ki) 1.5-fold higher than GC376 (a positive control) dependent of the catalytic water (H2Ocat) content. ATV was a competitive inhibitor, increasing the Mpro’s Michaelis–Menten (Km) more than sixfold. Cell-based assays indicated that different lineages of SARS-CoV-2 is susceptible to ATV. Using oral administration of ATV in mice to reach plasmatic exposure similar to humans, transgenic mice expression in human angiotensin converting enzyme 2 (K18-hACE2) were partially protected against lethal challenge with SARS-CoV-2 gamma. Moreover, less cell death and inflammation were observed in the lung from infected and treated mice. Our studies may contribute to a better comprehension of the Mpro/ATV interaction, which could pave the way to the development of specific inhibitors of this viral protease
A Sociedade de Medicina e Cirurgia do Rio de Janeiro: a gênese de uma rede institucional alternativa The Rio de Janeiro Medical and Surgical Society: the genesis of an alternative institutional network
Este artigo aborda a história da medicina no Brasil no final do século XIX, a partir da análise do surgimento da Sociedade de Medicina e Cirurgia do Rio de Janeiro. Nossa hipótese é de que, a partir da década de 1880, a reformulação das instituições e a diversificação da coletividade médica iniciaram a estruturação de um campo de relações sociais específicas aos praticantes da medicina. Diante da crise das instituições médicas oficiais, verifica-se o surgimento de grupos médicos alternativos que, à margem da tutela estatal, se articularam em torno cie objetivos comuns, em especial, a construção de um conhecimento médico nacional, que tivesse relevância no cenário científico internacional da época.<br>Creation of the Rio de Janeiro Medical and Surgical Society serves as the basis for this study of late-19th-century medicine in Brazil. The hypothesis is that beginning in the 1880s changes to institutions and the diversification of the medical community inaugurated the structuring of afield of social relations specific to medical practitioners. With official medical institutions undergoing crises, alternative groups that emerged outside the government framework worked together toward common ends, particularly the construction of a kind of Brazilian medical knowledge that could play a role on the international scientific scenario
Performance, carcass traits, meat quality and economic analysis of feedlot of young bulls fed oilseeds with and without supplementation of vitamin E
The objective of this research was to evaluate average daily gain (ADG), carcass traits, meat tenderness and profitability of keeping cattle fed different oilseeds and vitamin E in feedlot. A total of 40 Red Norte young bulls with initial average body weight of 339±15 kg were utilized. The experimental design was completely randomized in a 2 × 2 factorial arrangement. The experiment lasted 84 days and experimental diets presented soybeans or cottonseeds as lipid sources associated or not to daily supplementation of 2,500 UI vitamin E per animal. The concentrate:roughage ratio was 60:40. Diets had the same amount of nitrogen (13% CP) and ether extract (6.5%). The data were analyzed by means of statistical software SAS 9.1. Neither vitamin supplementation nor lipid source affected ADG. There was no interaction between lipid source and vitamin supplementation for the variables studied. The inclusion of cottonseed reduced the carcass yield. There was no effect of diets on hot and cold carcass weights or prime cuts. The inclusion of cottonseed reduced the backfat thickness. No effect of experimental diets on the rib-eye area was observed. There was no effect of lipid source or vitamin supplementation on meat tenderness, which was affected, however, by ageing time. Diets with soybeans presented higher cost per animal. The utilization of soybean implied reduction of the gross margin (R 60.51 for diets based on soy with and without supplemental vitamin, respectively, vs. R 131.79 for diets based on cottonseed). The utilization of cottonseed enables improvement of profitability of feedlot fattening, in spite of negatively affecting some carcass characteristics