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56 result(s) for "da Silva, Caroline G. F."
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Nanoencapsulation of Achyrocline satureioides (Lam) DC—Essential Oil and Controlled Release: Experiments and Modeling
Background/Objectives: Degradation by physical and chemical agents affects the properties of essential oils; therefore, this study aimed to protect the volatile compounds present in essential oils through biopolymer encapsulation. Methods: The Achyrocline satureioides (Lam) DC. essential oil was obtained by steam distillation at 2.5 bar. The nano-sized physical coating of the active oil core resulted in an optimal polymer/oil ratio of 1:3 and particle diameter of 178 nm. The particle morphology was evaluated using scanning electron microscopy and transmission electron microscopy. The inclusion of the essential oil in the polymer was confirmed using thermogravimetric analysis. Results: The pH of the formulation remained stable for 90 days, and controlled release and encapsulation efficiencies were evaluated. Formulations were evaluated using the perfumery radar technique, which indicated a predominantly woody profile. The diffusion of fragrant compounds in the air was assessed over time and mathematically modeled. Conclusions: The produced nanostructures were efficient for the controlled release of volatile compounds from the essential oil of Achyrocline satureioides.
Multicomponent Reactions Promoted by Ecocatalyst from Metal Hyperaccumulating Plant Pluchea sagittalis
Phytoremediation has been considered a sustainable environmental technology for heavy metals decontamination. In this work, we evaluated the metal contents by inductively coupled plasma optical emission spectrometry (ICP-OES) of three plant species collected in a mine in the Brazilian Amazonia area. Based on this analysis, Pluchea sagitallis leaves were selected to prepare metallic ecocatalysts. The leaf ashes and the obtained ecocatalysts were characterized by ICP-OES, X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2-physisorption measurements. Moreover, they were evaluated in the Biginelli and Hantzsch multicomponent reactions, furnishing the corresponding 3,4-dihydropyrimidin-2-(1H)-ones and 1,4-dihydropyridines with good to excellent yields. The best ecocatalyst was easily recovered and recycled in up to six reactions without a significant decrease in its performance.
Characterization and trypanocidal activity of a β-lapachone-containing drug carrier
The treatment of Chagas disease (CD), a neglected parasitic condition caused by Trypanosoma cruzi , is still based on only two drugs, nifurtimox ( Nif ) and benznidazole ( Bz ), both of which have limited efficacy in the late chronic phase and induce severe side effects. This scenario justifies the continuous search for alternative drugs, and in this context, the natural naphthoquinone β-lapachone ( β-Lap ) and its derivatives have demonstrated important trypanocidal activities. Unfortunately, the decrease in trypanocidal activity in the blood, high toxicity to mammalian cells and low water solubility of β-Lap limit its systemic administration and, consequently, clinical applications. For this reason, carriers as drug delivery systems can strategically maximize the therapeutic effects of this drug, overcoming the above mentioned restrictions. Accordingly, the aim of this study is to investigate the in vitro anti- T . cruzi effects of β-Lap encapsulated in2-hydroxypropyl-β-cyclodextrin ( 2HP-β-CD ) and its potential toxicity to mammalian cells.
Cross-Sectional Study on the Association Between Respiratory Muscle Strength and Dynapenic Abdominal Obesity in Community-Dwelling Older Adults
Purpose: Impaired respiratory muscle strength has been associated with some geriatric syndromes. However, no studies have previously evaluated the relationship between respiratory muscle strength and dynapenic abdominal obesity. This study aimed to analyze whether there is an association between respiratory muscle strength and abdominal obesity, dynapenia and dynapenic abdominal obesity (DAO) in community-dwelling older adults. Patients and Methods: Cross-sectional study conducted with community-dwelling older adults (n=382 / 70.03 [+ or -] 7.3 years) from Macapa, Amapa, Brazil. Respiratory muscle strength was assessed by measuring maximal inspiratory and expiratory pressures (MIP and MEP, respectively), using an analog manovacuometry. DAO was defined as the combination of dynapenia (grip strength < 26 kgf for men and < 16 kgf for women) and abdominal obesity (abdominal circumference > 102 cm for men and > 88 cm for women). We performed descriptive and inferential statistical analyses using the student's t-test for independent and related samples and linear regression model. Results: Older adults with abdominal obesity, dynapenia, and DAO presented lower mean values (obtained and obtained versus predicted; except abdominal obesity versus MIP) for maximal respiratory pressures compared to individuals without these conditions. However, the adjusted analysis only indicated an association between MIP and the following conditions: dynapenia (MIP - [beta] =-0.171; p<0.001), abdominal obesity (MIP - [beta]=0.102; p=0.042), and DAO (MIP - [beta]=-0.101; p=0.028). Conclusion: Older adults with abdominal obesity, dynapenia, and DAO showed impaired maximal respiratory pressures. The results of the adjusted analysis indicate that inspiratory muscle strength may require greater attention by health professionals aiming at preventing respiratory complications and improving respiratory health care in older people with these conditions. Keywords: respiratory muscles, muscle strength, respiratory function tests, obesity, abdominal, aged
Genomic, epidemiological and digital surveillance of Chikungunya virus in the Brazilian Amazon
Since its first detection in the Caribbean in late 2013, chikungunya virus (CHIKV) has affected 51 countries in the Americas. The CHIKV epidemic in the Americas was caused by the CHIKV-Asian genotype. In August 2014, local transmission of the CHIKV-Asian genotype was detected in the Brazilian Amazon region. However, a distinct lineage, the CHIKV-East-Central-South-America (ECSA)-genotype, was detected nearly simultaneously in Feira de Santana, Bahia state, northeast Brazil. The genomic diversity and the dynamics of CHIKV in the Brazilian Amazon region remains poorly understood despite its importance to better understand the epidemiological spread and public health impact of CHIKV in the country. We report a large CHIKV outbreak (5,928 notified cases between August 2014 and August 2018) in Boa vista municipality, capital city of Roraima's state, located in the Brazilian Amazon region. We generated 20 novel CHIKV-ECSA genomes from the Brazilian Amazon region using MinION portable genome sequencing. Phylogenetic analyses revealed that despite an early introduction of the Asian genotype in 2015 in Roraima, the large CHIKV outbreak in 2017 in Boa Vista was caused by an ECSA-lineage most likely introduced from northeastern Brazil. Epidemiological analyses suggest a basic reproductive number of R0 of 1.66, which translates in an estimated 39 (95% CI: 36 to 45) % of Roraima's population infected with CHIKV-ECSA. Finally, we find a strong association between Google search activity and the local laboratory-confirmed CHIKV cases in Roraima. This study highlights the potential of combining traditional surveillance with portable genome sequencing technologies and digital epidemiology to inform public health surveillance in the Amazon region. Our data reveal a large CHIKV-ECSA outbreak in Boa Vista, limited potential for future CHIKV outbreaks, and indicate a replacement of the Asian genotype by the ECSA genotype in the Amazon region.
Lipid droplets fuel SARS-CoV-2 replication and production of inflammatory mediators
Viruses are obligate intracellular parasites that make use of the host metabolic machineries to meet their biosynthetic needs. Thus, identifying the host pathways essential for the virus replication may lead to potential targets for therapeutic intervention. The mechanisms and pathways explored by SARS-CoV-2 to support its replication within host cells are not fully known. Lipid droplets (LD) are organelles with major functions in lipid metabolism, energy homeostasis and intracellular transport, and have multiple roles in infections and inflammation. Here we described that monocytes from COVID-19 patients have an increased LD accumulation compared to SARS-CoV-2 negative donors. In vitro , SARS-CoV-2 infection were seen to modulate pathways of lipid synthesis and uptake as monitored by testing for CD36, SREBP-1, PPARγ, and DGAT-1 expression in monocytes and triggered LD formation in different human cell lines. LDs were found in close apposition with SARS-CoV-2 proteins and double-stranded (ds)-RNA in infected Vero cells. Electron microscopy (EM) analysis of SARS-CoV-2 infected Vero cells show viral particles colocalizing with LDs, suggestive that LDs might serve as an assembly platform. Pharmacological modulation of LD formation by inhibition of DGAT-1 with A922500 significantly inhibited SARS-CoV-2 replication as well as reduced production of mediators pro-inflammatory response. Taken together, we demonstrate the essential role of lipid metabolic reprograming and LD formation in SARS-CoV-2 replication and pathogenesis, opening new opportunities for therapeutic strategies to COVID-19.
Adjuvant Cemiplimab or Placebo in High-Risk Cutaneous Squamous-Cell Carcinoma
In high-risk cutaneous squamous-cell carcinoma, adjuvant cemiplimab prolonged disease-free survival and reduced recurrence risk as compared with placebo. No new safety concerns with cemiplimab were seen.
Effects of β-alanine and sodium bicarbonate supplementation on the estimated energy system contribution during high-intensity intermittent exercise
The effects of β-alanine (BA) and sodium bicarbonate (SB) on energy metabolism during work-matched high-intensity exercise and cycling time-trial performance were examined in 71 male cyclists. They were randomised to receive BA + placebo (BA, n = 18), placebo + SB (SB, n = 17), BA + SB (BASB, n = 19), or placebo + placebo (PLA, n = 18). BA was supplemented for 28 days (6.4 g day−1) and SB (0.3 g kg−1) ingested 60 min before exercise on the post-supplementation trial. Dextrose and calcium carbonate were placebos for BA and SB, respectively. Before (PRE) and after (POST) supplementation, participants performed a high-intensity intermittent cycling test (HICT-110%) consisting of four 60-s bouts at 110% of their maximal power output (60-s rest between bouts). The estimated contribution of the energy systems was calculated for each bout in 39 of the participants (BA: n = 9; SB: n = 10; BASB: n = 10, PLA: n = 10). Ten minutes after HICT-110%, cycling performance was determined in a 30-kJ time-trial test in all participants. Both groups receiving SB increased estimated glycolytic contribution in the overall HICT-110%, which approached significance (SB: + 23%, p = 0.068 vs. PRE; BASB: + 18%, p = 0.059 vs. PRE). No effects of supplementation were observed for the estimated oxidative and ATP-PCr systems. Time to complete 30 kJ was not significantly changed by any of the treatments, although a trend toward significance was shown in the BASB group (p = 0.06). We conclude that SB, but not BA, increases the estimated glycolytic contribution to high-intensity intermittent exercise when total work done is controlled and that BA and SB, either alone or in combination, do not improve short-duration cycling time-trial performance.
The IgG glycome of SARS-CoV-2 infected individuals reflects disease course and severity
Immunoglobulin G (IgG) antibodies play an important role in the immune response against viruses such as SARS-CoV-2. As the effector functions of IgG are modulated by N -glycosylation of the Fc region, the structure and possible function of the IgG N -glycome has been under investigation in relation to divergent COVID-19 disease courses. Through LC-MS analysis we studied both total IgG1 and spike protein-specific IgG1 Fc glycosylation of 129 German and 163 Brazilian COVID-19 patients representing diverse patient populations. We found that hospitalized COVID-19 patients displayed decreased levels of total IgG1 bisection and galactosylation and lowered anti-S IgG1 fucosylation and bisection as compared to mild outpatients. Anti-S IgG1 glycosylation was dynamic over the disease course and both anti-S and total IgG1 glycosylation were correlated to inflammatory markers. Further research is needed to dissect the possible role of altered IgG glycosylation profiles in (dys)regulating the immune response in COVID-19.
Genomic analysis of two phlebotomine sand fly vectors of Leishmania from the New and Old World
Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the kinetoplastid parasites of the genus Leishmania , the causative agents of devastating diseases collectively termed leishmaniasis. More than 40 pathogenic Leishmania species are transmitted to humans by approximately 35 sand fly species in 98 countries with hundreds of millions of people at risk around the world. No approved efficacious vaccine exists for leishmaniasis and available therapeutic drugs are either toxic and/or expensive, or the parasites are becoming resistant to the more recently developed drugs. Therefore, sand fly and/or reservoir control are currently the most effective strategies to break transmission. To better understand the biology of sand flies, including the mechanisms involved in their vectorial capacity, insecticide resistance, and population structures we sequenced the genomes of two geographically widespread and important sand fly vector species: Phlebotomus papatasi , a vector of Leishmania parasites that cause cutaneous leishmaniasis, (distributed in Europe, the Middle East and North Africa) and Lutzomyia longipalpis , a vector of Leishmania parasites that cause visceral leishmaniasis (distributed across Central and South America). We categorized and curated genes involved in processes important to their roles as disease vectors, including chemosensation, blood feeding, circadian rhythm, immunity, and detoxification, as well as mobile genetic elements. We also defined gene orthology and observed micro-synteny among the genomes. Finally, we present the genetic diversity and population structure of these species in their respective geographical areas. These genomes will be a foundation on which to base future efforts to prevent vector-borne transmission of Leishmania parasites.