76 results on '"de Freitas RA"'
Search Results
2. Neurodevelopmental changes in Drosophila melanogaster are restored by treatment with lutein-loaded nanoparticles: Positive modulation of neurochemical and behavioral parameters.
- Author
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Janner DE, Poetini MR, Musachio EAS, Chaves NSG, Meichtry LB, Fernandes EJ, Mustafa MMD, De Carvalho AS, Gonçalves OH, Leimann FV, de Freitas RA, Prigol M, and Guerra GP
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- Animals, Male, Female, Neonicotinoids toxicity, Oxidative Stress drug effects, Insecticides toxicity, Neuroprotective Agents pharmacology, Neuroprotective Agents administration & dosage, Neurodevelopmental Disorders prevention & control, Neurodevelopmental Disorders chemically induced, Neurodevelopmental Disorders metabolism, Antioxidants pharmacology, Antioxidants metabolism, Drosophila melanogaster drug effects, Lutein pharmacology, Lutein administration & dosage, Nanoparticles, Behavior, Animal drug effects, Nitro Compounds toxicity
- Abstract
Neurodevelopmental disorders, such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), are characterized by persistent changes in communication and social interaction, as well as restricted and stereotyped patterns of behavior. The complex etiology of these disorders possibly combines the effects of multiple genes and environmental factors. Hence, exposure to insecticides such as imidacloprid (IMI) has been used to replicate the changes observed in these disorders. Lutein is known for its anti-inflammatory and antioxidant properties and is associated with neuroprotective effects. Therefore, the aim of this study was to evaluate the protective effect of lutein-loaded nanoparticles, along with their mechanisms of action, on Drosophila melanogaster offspring exposed to IMI-induced damage. To simulate the neurodevelopmental disorder model, flies were exposed to a diet containing IMI for 7 days. Posteriorly, their offspring were exposed to a diet containing lutein-loaded nanoparticles for a period of 24 h, and male and female flies were subjected to behavioral and biochemical evaluations. Treatment with lutein-loaded nanoparticles reversed the parameters of hyperactivity, aggressiveness, social interaction, repetitive movements, and anxiety in the offspring of flies exposed to IMI. It also protected markers of oxidative stress and cell viability, in addition to preventing the reduction of Nrf2 and Shank3 immunoreactivity. These results demonstrate that the damage induced by exposure to IMI was restored through treatment with lutein-loaded nanoparticles, elucidating lutein's mechanisms of action as a therapeutic agent, which, after further studies, can become a co-adjuvant in the treatment of neurodevelopmental disorders, such as ASD and ADHD., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
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3. Combined Percutaneous Transhepatic Lymphatic Embolization and Peroral Duodenal Mucosal Radiofrequency Ablation to Manage Protein-Losing Enteropathy.
- Author
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Husnain A, Aadam AA, Reiland A, Salem R, Baker J, Nemcek AA Jr, Green J, Ganger D, De Freitas RA, and Riaz A
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- Humans, Male, Female, Middle Aged, Adult, Aged, Treatment Outcome, Heart Defects, Congenital diagnostic imaging, Heart Defects, Congenital surgery, Heart Defects, Congenital therapy, Enbucrilate administration & dosage, Radiofrequency Ablation, Ethiodized Oil administration & dosage, Endoscopy, Digestive System, Combined Modality Therapy, Methylene Blue administration & dosage, Lymphatic Vessels diagnostic imaging, Protein-Losing Enteropathies therapy, Protein-Losing Enteropathies etiology, Protein-Losing Enteropathies diagnostic imaging, Embolization, Therapeutic, Lymphography, Duodenum diagnostic imaging, Duodenum blood supply, Intestinal Mucosa diagnostic imaging
- Abstract
Percutaneous transhepatic lymphatic embolization (PTLE) and peroral esophagogastroduodenoscopy (EGD) duodenal mucosal radiofrequency (RF) ablation were performed to manage protein-losing enteropathy (PLE) in patients with congenital heart disease. Five procedures were performed in 4 patients (3 men and 1 woman; median age, 49 years; range, 31-71 years). Transhepatic lymphangiography demonstrated abnormal periduodenal lymphatic channels. After methylene blue injection through transhepatic access, subsequent EGD evaluation showed methylene blue extravasation at various sites in the duodenal mucosa. Endoscopic RF ablation of the leakage sites followed by PTLE using 3:1 ethiodized oil-to-n-butyl cyanoacrylate glue ratio resulted in improved symptoms and serum albumin levels (before procedure, 2.6 g/dL [SD ± 0.2]; after procedure, 3.5 g/dL [SD ± 0.4]; P = .004) over a median follow-up of 16 months (range, 5-20 months). Transhepatic lymphangiography and methylene blue injection with EGD evaluation of the duodenal mucosa can help diagnose PLE. Combined PTLE and EGD-RF ablation is an option to treat patients with PLE., (Copyright © 2024 SIR. Published by Elsevier Inc. All rights reserved.)
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- 2024
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4. Interleukin-10 deficiency induces thoracic perivascular adipose tissue whitening and vascular remodeling.
- Author
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de Freitas RA, Dos Passos RR Jr, Dos Santos FCA, Bressan AFM, Carneiro FS, Lima VV, and Giachini FRC
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- Animals, Male, Mice, Uncoupling Protein 1 metabolism, Uncoupling Protein 1 genetics, Aorta, Thoracic metabolism, Aorta, Thoracic pathology, Collagen metabolism, Adipose Tissue metabolism, Interleukin-10 metabolism, Interleukin-10 genetics, Vascular Remodeling genetics, Mice, Knockout, Adipose Tissue, White metabolism, Mice, Inbred C57BL
- Abstract
Perivascular adipose tissue (PVAT) is an adipose layer, surrounding blood vessels, with a local modulatory role. Interleukin-10 (IL-10) has been shown to modulate vascular tissue. This study aimed to characterize the endogenous role of IL-10 in vascular remodeling, and PVAT phenotyping. Thoracic aortic segments from control (C57BL/6J) and IL-10 knockout (IL-10
-/- ) male mice were used. Analyzes of aorta/PVAT morphometry, and elastin, collagen and reticulin deposition were performed. Tissue uncoupling protein 1 (UCP1) was accessed by Western blotting. Endogenous absence of IL-10 reduced total PVAT area (p = 0.0310), and wall/lumen ratio (p = 0.0024), whereas increased vascular area and thickness (p < 0.0001). Total collagen deposition was augmented in IL-10-/- , but under polarized light, the reduction of collagen-I (p = 0.0075) and the increase of collagen-III (p = 0.0055) was found, simultaneously with reduced elastic fibers deposition (p = 0.0282) and increased deposition of reticular fibers (p < 0.0001). Adipocyte area was augmented in the IL-10 absence (p = 0.0225), and UCP1 expression was reduced (p = 0.0420). Moreover, relative frequency of white adipose cells and connective tissue was augmented in IL-10-/- (p < 0.0001), added to a reduction in brown adipose cells (p < 0.0001). Altogether, these data characterize aorta PVAT from IL-10-/- as a white-like adipocyte phenotype. Endogenous IL-10 prevents vascular remodeling and favors a brown-like adipocyte phenotype, suggesting a modulatory role for IL-10 in PVAT plasticity., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)- Published
- 2024
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5. Enhancing Vascular Health and Lowering Blood Pressure in Spontaneously Hypertensive Rats through Syrah Grape ( Vitis vinifera) Pomace: The Role of Phenolic Compounds.
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da Costa KCM, Oliveira LS, Silva JC, Santana TS, de Freitas RA, Bressan AFM, Gómez-Alonso S, Pérez-Navarro J, Pertuzatti PB, and Giachini FR
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- Animals, Male, Rats, Antioxidants pharmacology, Antioxidants analysis, Plant Extracts pharmacology, Fruit chemistry, Brazil, Vitis chemistry, Rats, Inbred SHR, Phenols analysis, Phenols pharmacology, Blood Pressure drug effects, Rats, Wistar, Hypertension drug therapy, Wine analysis, Antihypertensive Agents pharmacology
- Abstract
Background: The beneficial properties of wine by-products include actions that help prevent and treat cardiovascular conditions such as hypertension, primarily due to their antioxidant effects. Novel pharmacotherapies are being developed to treat arterial hypertension, including investigations into natural products exhibiting biological activity, necessitating rigorous evaluation of their efficacy and safety. This study aimed to identify and quantify phenolic compounds in Syrah ( Vitis vinifera ) grapes grown in the Brazilian Cerrado and their presence in winemaking by-products. It also examined the effects of grape pomace on blood pressure., Methods: Fresh grapes, pomace, and lees, were subjected to spectrophotometric determination of total phenolic compounds, followed by identification and quantification using HPLC-DAD-ESI-MSn. Normotensive male rats (Wistar) and spontaneously hypertensive rats (SHR) received grape pomace-enriched (150 or 300 mg/kg/day, 14 days) or standard chow. Indirect arterial pressure was assessed, while vascular reactivity was evaluated in mesenteric resistance arteries., Results: Pomace samples exhibited higher total phenolic compound concentrations than grapes or lees. Seven derivatives of hydroxycinnamic acids and twenty-one flavonols were identified. Quercetin-3-glucoside and ethyl caffeate were the most abundant phenolic compounds. Grape pomace-enriched chow demonstrated a dose-dependent hypotensive effect in rats., Conclusion: the abundance of flavonols and hydroxycinnamic acids, combined with their hypotensive effects, underscores the therapeutic potential of fine wine-making by-products produced in the Brazilian Cerrado.
- Published
- 2024
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6. Hepatocellular carcinoma in survivors after Fontan operation: a case-control study.
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Kim YY, Lluri G, Haeffele C, Daugherty T, Krasuski RA, Serfas JD, de Freitas RA, Porlier A, Lubert AM, Wu FM, Valente AM, Krieger EV, Buber J, Rodriguez FH 3rd, Gaignard S, Saraf A, Hindes M, Earing MG, Lewis MJ, Rosenbaum MS, Zaidi AN, Hopkins K, Bradley EA, Cedars AM, Ko JL, Franklin WJ, Frederickson A, Ginde S, Grewal J, Nyman A, Min J, Schluger C, Rand E, Rosenthal BE, Hilscher M, Rychik J, and Hoteit MA
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- Humans, Case-Control Studies, Survivors, Retrospective Studies, Carcinoma, Hepatocellular surgery, Liver Neoplasms surgery, Fontan Procedure adverse effects, Heart Defects, Congenital surgery
- Published
- 2024
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7. (1 → 3),(1 → 6) and (1 → 3)-β-D-glucan physico-chemical features drive their fermentation profile by the human gut microbiota.
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Zavadinack M, Cantu-Jungles TM, Abreu H, Ozturk OK, Cordeiro LMC, de Freitas RA, Hamaker BR, and Iacomini M
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- Humans, Glucans chemistry, Fermentation, Fatty Acids, Volatile, Water, beta-Glucans metabolism, Gastrointestinal Microbiome
- Abstract
Mushroom polysaccharides consist of a unique set of polymers that arrive intact in the human large intestine becoming available for fermentation by resident gut bacteria with potential benefits to the host. Here we have obtained four glucans from two mushrooms (Pholiota nameko and Pleurotus pulmonarius) under different extraction conditions and their fermentation profile by human gut bacteria in vitro was evaluated. These glucans were isolated and characterized as (1 → 3),(1 → 6)-β-D-glucans varying in branching pattern and water-solubility. An aliquot of each (1 → 3),(1 → 6)-β-D-glucan was subjected to controlled smith degradation process in order to obtain a linear (1 → 3)-β-D-glucan from each fraction. The four β-D-glucans demonstrated different water solubilities and molar mass ranging from 2.2 × 10
5 g.mol-1 to 1.9 × 106 g.mol-1 . In vitro fermentation of the glucans by human gut microbiota showed they induced different short chain fatty acid production (52.0-97.0 mM/50 mg carbohydrates), but an overall consistent high propionate amount (28.5-30.3 % of total short chain fatty acids produced). All glucans promoted Bacteroides uniformis, whereas Anaerostipes sp. and Bacteroides ovatus promotion was strongly driven by the β-D-glucans solubility and/or branching pattern, highlighting the importance of β-D-glucan discrete structures to their fermentation by the human gut microbiota., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)- Published
- 2024
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8. Production of highly antioxidant lignin nanoparticles from a hardwood technical lignin.
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Pavaneli G, da Silva TA, Zawadzki SF, Sassaki GL, de Freitas RA, and Ramos LP
- Subjects
- Lignin chemistry, Solvents, Water, Antioxidants chemistry, Nanoparticles chemistry
- Abstract
Eucalypt kraft lignin isolated in a LignoBoost™ pilot plant was characterized by GC-MS, ICP-OES, DSC, HPSEC,
31 P NMR, and HSQC 2D-NMR to be used without any further processing to produce lignin nanoparticles (LNPs) by nanoprecipitation. Tetrahydrofuran (THF) was used as a solvent, and water as a non-solvent. Microscopic analysis (TEM) showed that LNPs were regularly spherical with some hollow particles dispersed in-between, and sizes were tunable by changing the solvent dripping rate onto the non-solvent. LNP particle sizes had a bimodal distribution, with the largest population having an average apparent hydrodynamic diameter ranging from 105.6 to 75.6 nm. Colloidal dispersions of LNPs in water presented good stability in different dilutions without significant size changes upon storage at pH close to neutral for as long as 45 days. Zeta potentials around -40 mV were obtained for LNP suspensions at pH ranging from 7 to 9. The high carbohydrate content (circa 10 % on a dry basis, mostly xylans) of the lignin precursor did not interfere in LNP formation, whose antioxidant activity was expressive as demonstrated by the ABTS assay at pH 7.4, with an EC50 of 4.04 μg mL-1 . Also, the Trolox® equivalent antioxidant capacity (TEAC) of LNPs reached 1.90 after 40 min reaction time., Competing Interests: Declaration of competing interest Luiz Pereira Ramos reports financial support was provided by National Council for Scientific and Technological Development. Giuliana Pavaneli reports financial support was provided by Coordination of Higher Education Personnel Improvement. Nothing to declare., (Copyright © 2023 Elsevier B.V. All rights reserved.)- Published
- 2024
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9. Percutaneous coronary intervention for ventricular fibrillation in the setting of an anomalous right coronary artery.
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Saleh D, Cantey EP, Marogi EP, Freed BH, Knight BP, de Freitas RA, Sweis RN, and Flaherty JD
- Abstract
We present a case of a quadriplegic male who developed ventricular fibrillation associated with an anomalous aortic origin of the right coronary artery. Successful revascularization was achieved with percutaneous coronary intervention. This case highlights the application of an unconventional approach to resolve ischemia in a patient with prohibitive surgical risk., Competing Interests: Dr. Knight has received research grants from and has served as a consultant for Abbott, Biotronik, Boston Scientific, and Medtronic. Dr. Sweis is a part of the Speakers' Bureau with Edwards Lifesciences., (© 2023 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd.)
- Published
- 2023
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10. Piezo1 activation induces relaxation of the pudendal artery and corpus cavernosum.
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Dela Justina V, de Freitas RA, Arishe OO, Giachini FR, Webb RC, and Priviero F
- Abstract
Piezo1 channel is a sensor for shear-stress in the vasculature. Piezo1 activation induces vasodilation, and its deficiency contributes to vascular disorders, such as hypertension. In this study, we aimed t o determine whether Piezo1 channel has a functional role in the dilation of pudendal arteries and corpus cavernosum (CC). For this, male Wistar rats were used, and the relaxation of the pudendal artery and CC was obtained using the Piezo1 activator, Yoda1, in the presence and absence of Dooku (Yoda1 antagonist), GsMTx4 (non-selective mechanosensory channel inhibitor) and L-NAME (nitric oxide synthase inhibitor). In the CC, Yoda1 was also tested in the presence of indomethacin (non-selective COX inhibitor) and tetraethylammonium (TEA, non-selective potassium channel inhibitor). The expression of Piezo1 was confirmed by Western blotting. Our data show that Piezo1 activation leads to the relaxation of the pudendal artery and CC as the chemical activator of Piezo1, Yoda1, relaxed the pudendal artery (47%) and CC (41%). This response was impaired by L-NAME and abolished by Dooku and GsMTx4 in the pudendal artery only. Indomethacin and TEA did not affect the relaxation induced by Yoda1 in the CC. Limited tools to explore this channel prevent further investigation of its underlying mechanisms of action. In conclusion, our data demonstrate that Piezo1 is expressed and induced the relaxation of the pudendal artery and CC. Further studies are necessary to determine its role in penile erection and if erectile dysfunction is associated with Piezo1 deficiency., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Dela Justina, de Freitas, Arishe, Giachini, Webb and Priviero.)
- Published
- 2023
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11. Protein O -GlcNAcylation as a nutrient sensor signaling placental dysfunction in hypertensive pregnancy.
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Dos Passos Junior RR, de Freitas RA, Dela Justina V, San Martín S, Lima VV, and Giachini FR
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- Female, Pregnancy, Rats, Male, Animals, Rats, Wistar, Rats, Inbred SHR, Placentation, Nutrients, Placenta metabolism, Hypertension
- Abstract
Introduction: During pregnancy, arterial hypertension may impair placental function, which is critical for a healthy baby's growth. Important proteins during placentation are known to be targets for O-linked β-N-acetylglucosamine modification (O-GlcNAcylation), and abnormal protein O-GlcNAcylation has been linked to pathological conditions such as hypertension. However, it is unclear how protein O-GlcNAcylation affects placental function and fetal growth throughout pregnancy during hypertension., Methods: To investigate this question, female Wistar and spontaneously hypertensive rats (SHR) were mated with male Wistar rats, and after pregnancy confirmation by vaginal smear, rats were divided into groups of 14, 17, and 20 days of pregnancy (DOPs). On the 14th, 17th, and 20th DOP, rats were euthanized, fetal parameters were measured, and placentas were collected for western blot, immunohistochemical, and morphological analyses., Results: SHR presented a higher blood pressure than the Wistar rats (p=0.001). Across all DOPs, SHR showed reduced fetal weight and an increase in small-for-gestational-age fetuses. While near-term placentas were heavier in SHR (p=0.006), placental efficiency decreased at 17 (p=0.01) and 20 DOPs (p<0.0001) in this group. Morphological analysis revealed reduced junctional zone area and labyrinth vasculature changes on SHR placentas in all DOPs. O-GlcNAc protein expression was lower in placentas from SHR compared with Wistar at 14, 17, and 20 DOPs. Decreased expression of O-GlcNAc transferase (p=0.01) and O-GlcNAcase (p=0.002) enzymes was found at 14 DOPs in SHR. Immunohistochemistry showed reduced placental O-GlcNAc content in both the junctional zone and labyrinth of the placentas from SHR. Periodic acid-Schiff analysis showed decreased glycogen cell content in the placentas from SHR at 14, 17, and 20 DOPs. Moreover, glucose transporter 1 expression was decreased in placentas from SHR in all DOPs., Conclusions: These findings suggest that decreased protein O-GlcNAcylation caused by insufficient placental nutritional apport contributes to placental dysfunction during hypertensive pregnancy, impairing fetal growth., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 dos Passos Junior, de Freitas, Dela Justina, San Martín, Lima and Giachini.)
- Published
- 2022
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12. In vitro evaluation of the inhalation toxicity of the cosmetic ingredient aluminum chlorohydrate.
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Thá EL, Gagosian VSC, Canavez ADPM, Schuck DC, Brohem CA, Gradia DF, de Freitas RA, Prado KB, Cestari MM, Lorencini M, and Leme DM
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- Humans, Administration, Inhalation, Aerosols, Pharmaceutical Vehicles, Inhalation Exposure adverse effects, Aluminum, Cosmetics
- Abstract
Aluminum chlorohydrate (ACH) is a major aerosol component frequently used as the active ingredient in antiperspirants, and in vivo studies have raised a concern about its inhalation toxicity. Still, few studies have addressed its effects on the human respiratory tract. Therefore, we developed a study on ACH inhalation toxicity using an in vitro human alveolar cell model (A549 cells) with molecular and cellular markers of oxidative stress, immunotoxicity, and epigenetic changes. The chemical characterization of ACH suspensions indicated particle instability and aggregation; however, side-scatter analysis demonstrated significant particle uptake in cells exposed to ACH. Exposure of A549 cells to non-cytotoxic concentrations of ACH (0.25, 0.5, and 1 mg/ml) showed that ACH induced reactive oxygen species. Moreover, ACH upregulated TNF, IL6, IL8, and IL1A genes, but not the lncRNAs NEAT1 and MALAT1. Finally, no alterations on the global DNA methylation pattern (5-methylcytosine and 5-hydroxymethylcytosine) or the phosphorylation of histone H2AX (γ-H2AX) were observed. Our data suggest that ACH may induce oxidative stress and inflammation on alveolar cells, and A549 cells may be useful to identify cellular and molecular events that may be associated with adverse effects on the lungs. Still, further research is needed to ensure the inhalation safety of ACH., (© 2022 John Wiley & Sons Ltd.)
- Published
- 2022
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13. Rheological and microstructural characterisation of heat-induced whey protein isolate gels affected by the addition of caseinomacropeptide.
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Guedes PV, de Freitas RA, Franco CRC, and Cândido LMB
- Abstract
Caseinomacropeptide (CMP) is derived from the chymosin cleavage of κ-casein during cheese production. This study developed gels from CMPs, which were isolated by different ultrafiltration systems, and whey protein isolate (WPI), and studied their rheological and ultrastructural characteristics. The 30% WPI gel showed high elastic modulus (G') values and stronger structure than the other samples with CMP. Another gel, with 50% protein, 30% WPI and 20% CMP sample isolated from the 30 kDa retentate, had a weaker structure and lower G' value. The third gel, with 30% WPI and 20% CMP sample from the 5 kDa retentate derived from the 30 kDa retentate, presented intermediate structural strength. Despite the increase in protein concentration from the addition of CMP, there was a decrease in the strength of the gel network. Different CMP isolation processes also contributed to differences in the microscopic analysis of gel structures with the same protein content.
- Published
- 2022
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14. Interleukin-10 in the Vasculature: Pathophysiological Implications.
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de Freitas RA, Lima VV, Bomfim GF, and Giachini FRC
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- Animals, Anti-Inflammatory Agents therapeutic use, Cytokines, Humans, Vasoconstriction, Antihypertensive Agents, Interleukin-10
- Abstract
Interleukin-10 (IL-10) is an important immunomodulatory cytokine, initially characterized as an anti-inflammatory agent released by immune cells during infectious and inflammatory processes. IL-10 exhibits biological functions that extend to the regulation of different intracellular signaling pathways directly associated with vascular function. This cytokine plays a vital role in vascular tone regulation by changing important proteins involved in vasoconstriction and vasodilation. Numerous investigations covered here have shown that therapeutic strategies inducing IL-10 exert anti-inflammatory, anti-hypertrophic, anti-hyperplastic, anti-apoptotic and antihypertensive effects. This non-systematic review summarizes the modulating effects mediated by IL-10 in vascular tissue, particularly on vascular tone, and the intracellular pathway induced by this cytokine. We also highlight the advances in IL-10 manipulation as a therapeutic target in different cardiovascular pathophysiologies, including the physiological implications in animals and humans. Finally, the review illustrates current and potential future perspectives of the potential use of IL-10 in clinical trials based on the clinical evidence., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
- Published
- 2022
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15. Degradation of the residual textile mixture cetyltrimethylammonium bromide/remazol yellow gold RNL-150%/reactive blue BF-5G: evaluation photo-peroxidation and photo-Fenton processes in LED and UV-C photoreactors.
- Author
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do Nascimento GE, de Freitas RA, Rodríguez-Díaz JM, da Silva PM, Napoleão TH, and Duarte MMMB
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- Azo Compounds, Cetrimonium, Iron, Oxidation-Reduction, Sulfanilic Acids, Textiles, Triazines, Hydrogen Peroxide, Water Pollutants, Chemical
- Abstract
This article presents a study on the degradation of a residual textile mixture composed of cationic surfactant cetyltrimethylammonium bromide (CTAB) and the remazol yellow gold RNL-150% and reactive blue BF-5G textile dyes. This was carried out by employing the photo-peroxidation and photo-Fenton processes in LED and UV-C photoreactors. The photo-Fenton process was the most efficient as regards the degradation of the CTAB and dye mixture, for both types of radiation. In the kinetic study, degradations of 99% were obtained in 180 min for the chromophore groups using both types of radiation. The degradation of the CTAB and aromatic groups was, meanwhile, an average of 25% when employing LED radiation. The behavior of the degradation reaction was pseudo-first-order. Toxicity tests indicated that the solutions were better able to grow seeds and bacteria after treatment with the photo-Fenton process, using both types of radiation. The photo-Fenton processes carried out by employing LED and UV-C photoreactors were able to degrade the CTAB and dye mixture, thus highlighting the efficiency of LED radiation when its power (three times smaller) is compared to that of UV-C radiation. This process, therefore, represents an alternative for use in textile wastewater treatment systems., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2021
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16. High Levels of Tumor Necrosis Factor-Alpha Reduce Placental Aquaporin 3 Expression and Impair in vitro Trophoblastic Cell Migration.
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Dos Passos Junior RR, de Freitas RA, Reppetti J, Medina Y, Dela Justina V, Bach CW, Bomfim GF, Lima VV, Damiano AE, and Giachini FR
- Abstract
Placentas from preeclamptic women display augmented tumor necrosis factor-alpha (TNF-α) levels with reduced expression of aquaporin 3 (AQP3). However, whether TNF-α modulates AQP3 expression remains to be elucidated. We hypothesize that elevated levels of TNF-α reduce AQP3 expression and negatively impact trophoblastic cell migration. Spontaneously hypertensive rats (SHRs) and Wistar rats (14-16 weeks) were divided into hypertensive and normotensive groups, respectively. Systolic blood pressure (SBP) was measured, and animals mated. In a third group, pregnant SHRs were treated with a TNF-α antagonist, etanercept (0.8 mg/kg, subcutaneously) on days 0, 6, 12, and 18 of pregnancy. Placentas were collected on the 20th day of pregnancy. Human placental explants, from normotensive pregnancies, were incubated with TNF-α (5, 10, and 20 ng/ml) and/or etanercept (1 μg/ml). Swan 71 cells were incubated with TNF-α (10 ng/ml) and/or etanercept (1 μg/ml) and subjected to the wound healing assay. AQP3 expression was assessed by Western blot and TNF-α levels by ELISA. SBP (mmHg) was elevated in the hypertensive group, and etanercept treatment reduced this parameter. Placental TNF-α levels (pg/ml) were higher in the hypertensive group. AQP3 expression was reduced in the hypertensive group, and etanercept treatment reversed this parameter. Explants submitted to TNF-α exposition displayed reduced expression of AQP3, and etanercept incubation reversed it. Trophoblastic cells incubated with TNF-α showed decreased cell migration and reduced AQP3 expression, and etanercept incubation ameliorated it. Altogether, these data demonstrate that high TNF-α levels negatively modulate AQP3 in placental tissue, impairing cell migration, and its relationship in a pregnancy affected by hypertension., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 dos Passos Junior, de Freitas, Reppetti, Medina, Dela Justina, Bach, Bomfim, Lima, Damiano and Giachini.)
- Published
- 2021
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17. Sensing soluble uric acid by Naip1-Nlrp3 platform.
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Braga TT, Davanso MR, Mendes D, de Souza TA, de Brito AF, Cruz MC, Hiyane MI, de Lima DS, Nunes V, de Fátima Giarola J, Souto DEP, Próchnicki T, Lauterbach M, Biscaia SMP, de Freitas RA, Curi R, Pontillo A, Latz E, and Camara NOS
- Subjects
- Animals, Fatty Acids metabolism, Humans, Inflammasomes genetics, Inflammasomes immunology, Interleukin-1beta metabolism, Macaca mulatta, Macrophages immunology, Macrophages metabolism, Mice, Inbred C57BL, NLR Family, Pyrin Domain-Containing 3 Protein genetics, Neuronal Apoptosis-Inhibitory Protein genetics, Protein Binding, THP-1 Cells, Uric Acid metabolism, Mice, Inflammasomes metabolism, Macrophages drug effects, NLR Family, Pyrin Domain-Containing 3 Protein metabolism, Neuronal Apoptosis-Inhibitory Protein metabolism, Uric Acid pharmacology
- Abstract
Uric acid (UA), a product of purine nucleotide degradation able to initiate an immune response, represents a breakpoint in the evolutionary history of humans, when uricase, the enzyme required for UA cleavage, was lost. Despite being inert in human cells, UA in its soluble form (sUA) can increase the level of interleukin-1β (IL-1β) in murine macrophages. We, therefore, hypothesized that the recognition of sUA is achieved by the Naip1-Nlrp3 inflammasome platform. Through structural modelling predictions and transcriptome and functional analyses, we found that murine Naip1 expression in human macrophages induces IL-1β expression, fatty acid production and an inflammation-related response upon sUA stimulation, a process reversed by the pharmacological and genetic inhibition of Nlrp3. Moreover, molecular interaction experiments showed that Naip1 directly recognizes sUA. Accordingly, Naip may be the sUA receptor lost through the human evolutionary process, and a better understanding of its recognition may lead to novel anti-hyperuricaemia therapies.
- Published
- 2021
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18. Interaction of guar gum galactomannans with the anionic surfactant sodium lauryl ether sulphate.
- Author
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de Seixas-Junior CH, de Carvalho MM, Jacumazo J, Piazza RD, Parchen GP, and de Freitas RA
- Subjects
- Galactose analogs & derivatives, Galactans chemistry, Mannans chemistry, Plant Gums chemistry, Sodium Dodecyl Sulfate chemistry, Surface-Active Agents chemistry
- Abstract
The interaction between galactomannans, guar gum (GG) with sodium lauryl ether sulphate (SLES) was demonstrated using conductometric, tensiometric, pyrene probe and
1 H NMR analyses. SLES and GG formed aggregates and reduced the surface tension at a critical aggregation concentration. The interaction was attributed to the presence of surfactant ethoxyl (EO) groups, since in conductometric, tensiometry and pyrene probe analyses using the non-ethoxylated form, sodium lauryl sulphate - SLS, no aggregation was observed. The aggregates formed between SLES and GG presented a negative zeta potential indicating that the polymer is surrounded by SLES and according to the dynamic light scattering analysis (DLS), presented a size of approximately 26 nm. The determination of the thermodynamic parameters showed that the aggregation occurs spontaneously and is a driven-enthalpy and entropy process. SLES and GG interaction could be explored to produce formulations with lower concentrations of surfactants, using commonly used thickeners as GG., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2020
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19. Angiotensin (1-7) Inhibits Ang II-mediated ERK1/2 Activation by Stimulating MKP-1 Activation in Vascular Smooth Muscle Cells.
- Author
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Sousa-Lopes A, de Freitas RA, Carneiro FS, Nunes KP, Allahdadi KJ, Webb RC, Tostes RC, Giachini FR, and Lima VV
- Abstract
The renin-angiotensin system (RAS) exerts profound physiological effects on blood pressure regulation and fluid homeostasis, mainly by modulating renal, cardiovascular, and central nervous systems. Angiotensin (Ang)-(1-7), an end-product of RAS, is recognized by its cardiovascular protective properties through stimulation of the Mas receptor, including vasodilation, anti-inflammatory, and antihypertensive actions, and consequently, counter-regulating the well-known Ang II-elicited actions. The overall hypothesis of this study is that Ang-(1-7) inhibits Ang II-induced ERK1/2 activation in vascular smooth muscle cells (VSMCs), via regulation of mitogen-activated protein phosphatase-1 (MKP-1) activity. Aortas from male Wistar rats were incubated with Ang-(1-7) or vehicle. Concentration-response curves to Ang II were performed in endothelium-denuded aortas, in the presence or absence of ERK1/2 (PD98059) inhibitor or Mas receptor (A-779) antagonist. Expression of proteins was assessed by western blot, and immunohistochemistry was conducted in VSMCs. Ang-(1-7) incubation decreased Ang II-induced contractile response in aortas, and this effect was not observed in the presence of PD98059 or A-779. Stimulation of VSMCs with Ang-(1-7) prevented Ang II-induced ERK1/2 phosphorylation, but not C-Raf-activation. Furthermore, Ang II decreased MKP-1 phosphorylation in VSMCs. Interestingly, simultaneous incubation of Ang-(1-7) with Ang II favored MKP-1 phosphorylation, negatively modulating ERK1/2 activation in VSMCs. The results suggest that Ang-(1-7) counter-regulates actions evoked by Ang II overproduction, as observed in cardiovascular diseases, mainly by modulating MKP-1 activity. This evidence suggests that the role of Ang-(1-7) in MKP-1-regulation represents a target for new therapeutic development.
- Published
- 2020
- Full Text
- View/download PDF
20. Production, characterization, and biological activity of a chitin-like EPS produced by Mortierella alpina under submerged fermentation.
- Author
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Goyzueta M LD, Noseda MD, Bonatto SJR, de Freitas RA, de Carvalho JC, and Soccol CR
- Subjects
- Antineoplastic Agents chemistry, Antioxidants chemistry, Breast Neoplasms pathology, Female, Glucose metabolism, Humans, Polysaccharides chemistry, Polysaccharides isolation & purification, Tumor Cells, Cultured, Antineoplastic Agents pharmacology, Antioxidants pharmacology, Breast Neoplasms drug therapy, Chitin chemistry, Fermentation, Mortierella metabolism, Polysaccharides pharmacology
- Abstract
The production of a chitin-like exopolysaccharide (EPS) was optimized through experimental design methods, evaluating the influence of urea, phosphate, and glucose. Under optimized conditions, up to 1.51 g/L was produced and its physicochemical characteristics were evaluated by chromatography, NMR, and FTIR spectroscopy, and rheological techniques. The results showed a homogeneous EPS (Mw 4.9 × 10
5 g mol-1 ) composed of chitin, linear polymer of β-(1→4)-linked N-acetyl-d-glucosamine residues. The acetylation degree as determined by13 C CP-MAS NMR spectroscopy was over 90 %. The EPS biological activities, such as antioxidant effect and antitumor properties, were evaluated. To the best of our knowledge, this is the first study on the production of a new alternative of extracellular chitin-like polysaccharide with promising bioactive properties from the filamentous fungus M. alpina., (Copyright © 2020 Elsevier Ltd. All rights reserved.)- Published
- 2020
- Full Text
- View/download PDF
21. Conformational analysis of ulvans from Ulva fasciata and their anticoagulant polycarboxylic derivatives.
- Author
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de Carvalho MM, Noseda MD, Dallagnol JCC, Ferreira LG, Ducatti DRB, Gonçalves AG, de Freitas RA, and Duarte MER
- Subjects
- Humans, Molecular Conformation, Molecular Weight, Partial Thromboplastin Time, Anticoagulants chemistry, Anticoagulants isolation & purification, Anticoagulants pharmacology, Ulva chemistry
- Abstract
This study investigates conformational aspects of ulvans (F2) and their polycarboxyl derivatives obtained through periodate-chlorite oxidation (C3) followed by DEAE-Sephacel fractioning (C3b and C3c). Size exclusion chromatography coupled with laser light scattering and viscometric detection, in addition to circular dichroism (CD) and molecular modeling analyses, suggested that F2 had a compact sphere conformation with a helical motif as secondary structure. In contrast, all the polycarboxyl ulvans showed a random coil conformation, although C3c (NaSO
3 - 21.0%; COO- 1.81 mmol·g-1 ; Mw 18 kg·mol-1 ) had a more rigid and constrained backbone than C3 (NaSO3 - 21.0%; COO- 1.81 mmol·g-1 ; Mw 49 kg·mol-1 ), largely due to its higher sulfate and carboxyl content. Despite the higher ionic character of C3c, its anticoagulant activity (ACA), determined by activated partial thromboplastin time (APTT) assay, was not improved compared to that of C3. Moreover, C3b (NaSO3 - 14.1%; COO- 1.23 mmol·g-1 ; Mw 8.1 kg·mol-1 ) had higher activity than F2 (NaSO3 - 20.6.%; COO- 0.36 mmol·g-1 ; Mw 123 kg·mol-1 ), even with its lower sulfate content and molar mass. These results suggest that the ACA of polycarboxyl ulvans relies on carboxyl and sulfate content and may depend, in addition, on a proper flexible conformation., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2020
- Full Text
- View/download PDF
22. Modulation of Epidermal Growth Factor Release by Biopolymer-Coated Liposomes.
- Author
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Parchen GP, Jacumazo J, Koop HS, Biscaia SMP, Trindade ES, Silveira JLM, and de Freitas RA
- Subjects
- Alginates, Animals, Epidermal Growth Factor, Skin, Swine, Chitosan, Liposomes
- Abstract
This work describes the development of polysaccharide-coated liposomes to modulate the delivery of epidermal growth factor (EGF), with the aim to produce different EGF release profiles depending on the milieu of infected wounds. For this purpose, cationic liposomes were coated with one layer of sodium alginate (ALG) followed by one layer of chitosan (CHI) using the layer-by-layer (LbL) technique. The coated liposomes exhibited apparent hydrodynamic diameters of 278 ± 36 and 216 ± 96 nm for Lip-ALG and Lip-ALG-CHI, respectively. Thus, it appears that adding the CHI layer compacted the Lip-ALG one. The incorporation efficiency of EGF was a maximum of 55% for liposomes with a polymeric coating. In vitro release experiments showed that Lip-ALG-CHI exhibits a higher release rate constant under acidic pH conditions, resembling those of infected tissue. Using an ex vivo model of EGF release in porcine ear skin, these liposomes were found to accumulate in the epidermis. Thus, coated liposomes could represent a local EGF delivery mechanism to promote healing., (Copyright © 2020 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
23. Development, characterization and antimicrobial activity of sodium dodecyl sulfate-polysaccharides capsules containing eugenol.
- Author
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Jacumazo J, de Carvalho MM, Parchen GP, Campos IMF, Ballesteros Garcia MJ, Brugnari T, Maciel GM, Marques FA, and de Freitas RA
- Subjects
- Anti-Infective Agents pharmacology, Aspergillus drug effects, Aspergillus pathogenicity, Candida albicans drug effects, Candida albicans pathogenicity, Capsules pharmacology, Chitosan chemistry, Eugenol pharmacology, Microbial Sensitivity Tests, Polysaccharides pharmacology, Sodium Dodecyl Sulfate chemistry, Anti-Infective Agents chemistry, Capsules chemistry, Eugenol chemistry, Polysaccharides chemistry
- Abstract
This work describes the production of polysaccharide multilayer capsules to control the release of Eugenol (Eug) and enabling its use as an antimicrobial agent. For this propose, oil-in-water nanoemulsions of sodium dodecyl sulfate were coated with alternating depositions of chitosan and carboxymethylcellulose using the Layer-by-Layer (LbL) technique, resulting in capsules containing 1-5 layers. The average size ranged from 188 ± 30 (LbL
1 ) to 1415 ± 517 nm (LbL5 ). The maximum incorporation efficiency was 70.8 ± 2.7 % for Eug-SDS-LbL1 . The initial burst releases decreased in proportion to the increase in the number of polysaccharide layers (22.3 ± 3.1 %-12.8 ± 1.6 %), and are influenced by the pH. These systems exhibited antifungal activity against Aspergillus niger, Trichoderma sp, Gliocladium sp, and Candida albicans, and Eug minimum inhibitory concentrations were lower as compared to those of the free agent. Therefore, these capsules represent promising antifungal materials for application in various fields., (Copyright © 2019. Published by Elsevier Ltd.)- Published
- 2020
- Full Text
- View/download PDF
24. Retinal toxicity after facial laser epilation.
- Author
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Plăcintă IA, De Freitas RA, Rahhal-Ortuño M, and Udaondo P
- Subjects
- Adult, Eye Injuries diagnostic imaging, Eye Injuries physiopathology, Humans, Male, Retina diagnostic imaging, Retina physiopathology, Retinal Diseases diagnostic imaging, Retinal Diseases physiopathology, Tomography, Optical Coherence, Visual Acuity physiology, Eye Injuries etiology, Hair Removal methods, Hirsutism surgery, Laser Therapy adverse effects, Lasers, Solid-State adverse effects, Retina injuries, Retinal Diseases etiology
- Abstract
A 39-year-old man presented to the ophthalmology emergency room complaining of decreased visual acuity and metamorphopsia on his left eye after undergoing Nd:YAG facial hair epilation without wearing proper eye protection. Fluorescein angiography showed a foveal staining initially, with an increase in foveal leakage over late phases. On optical coherence tomography, a subfoveal retinal pigment epithelial detachment with associated subretinal fluid and no signs of choroidal neovascularization or cystoid macular edema was observed. Observation with monthly follow-ups was adopted. By the fourth month, the subretinal fluid had already disappeared and visual acuity had returned to 20/20. Over one-year follow-up, the retinal pigment epithelial detachment experienced a decrease in its size. Conservative management may be a valid option in assessing accidental foveal photocoagulation when choroidal neovascularization or cystoid macular edema is absent. The use of wavelength specific goggles is mandatory for the patient and the aesthetician operating the cosmetic laser, especially when operating on the face or around the eyes. Abbreviations: Nd:YAG = neodymium-doped yttrium aluminium garnet, OCT = optical coherence tomography, PED = pigment epithelial detachment, CME = cystoid macular edema., (©Romanian Society of Ophthalmology.)
- Published
- 2020
25. Effects of Eugenia umbelliflora O. Berg (Myrtaceae)-leaf extract on inflammation and hypersensitivity.
- Author
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Goldoni FC, Barretta C, Nunes R, Broering MF, De Faveri R, Molleri HT, Corrêa TP, Farias IV, Amorin CK, Pastor MVD, Meyre-Silva C, Bresolin TMB, de Freitas RA, Quintão NLM, and Santin JR
- Subjects
- Animals, Anti-Inflammatory Agents chemistry, Antioxidants chemistry, Carrageenan, Cytokines immunology, Edema chemically induced, Edema immunology, Hypersensitivity drug therapy, Hypersensitivity immunology, Locomotion drug effects, Male, Mice, Phytochemicals analysis, Phytochemicals therapeutic use, Plant Extracts chemistry, Plant Leaves, Anti-Inflammatory Agents therapeutic use, Antioxidants therapeutic use, Edema drug therapy, Eugenia, Plant Extracts therapeutic use
- Abstract
Ethnopharmacological Relevance: The leaves of Eugenia species are widely used in popular medicine to treat several diseases, such as arthritis, rheumatism and diabetes. Eugenia umbelliflora O. Berg is popularly known in Brazil as "baguaçu", name also conferred to Eugenia jambolana probably due to their apparent similarity. Although the popular use scientifically proved of E. jambolana as anti-diabetes and also as anti-inflammatory, there are only two scientific studies demonstrating anti-ulcer and bactericide activities of E. umbelliflora leaves extract, without reference to its possible anti-inflammatory activity., Aim of the Study: The aim of this study was to show the anti-oxidant and anti-inflammatory activity of the methanol extract obtained from E. umbelliflora leaves (EuL) using in vitro and in vivo protocols., Materials and Methods: The total phenolic content was evaluated using the folin-Ciocalteu colorimetric method and phloroglucinols content by HPLC. The anti-oxidant activity was evaluated by ORAC, ABTS
•+ , DPPH, and metal chelation methods. The anti-inflammatory activity was investigated using carrageenan-induced inflammation in the subcutaneous tissue of male Swiss mice orally pre-treated with the EuL (0.3, 1 or 3 mg/kg). The leukocyte influx (optical microscopy) and secretion of chemical mediators (TNF, IL-6, IL-1β and CXCL1, by enzyme-linked immunosorbent assay) were quantified in the inflamed exudate. Histological analysis of the pouches was also performed. The anti-hypersensitive activity was investigated using carrageenan-induced mechanical hypersensitivity and mice were then evaluated using the von Frey filaments. The Open Field test was used to evaluate possible interference of adverse effect of EuL on locomotor activity that could lead to misinterpretation of the hypersensitivity evaluation., Results: The EuL demonstrated important and moderate reducing capacity on ABTS•+ and DPPH assays, respectively, but with slight activity in ORAC test. It reflects low protection against cell damage. The EuL also presented 30% of phenolic compounds. The phloroglucinols content of EuL was 25.9 mg/g, 18.4 mg/g and 16.6 mg/g of eugenial C, eugenial D and eugenial E, respectively. The in vivo analysis of the inflammatory exudate of EuL-treated mice demonstrated reduction in the polymorphonuclear cells (PMN) migration to the inflamed tissue, as well as the reduction of the pro-inflammatory cytokine IL-1β. Histologically, it was observed evident decrease in the oedema, formed essentially by non-haemorrhagic fibrin exudate, as well as PMN infiltrate, when compared with control mice injected with carrageenan. Furthermore, the extract also presented effective reduction of the mechanical hypersensitivity induced by carrageenan without any interference in animal's locomotor and exploratory activity., Conclusions: Together, the results herein obtained show that EuL presented anti-inflammatory activity by decreasing the influx of PMN to the inflamed tissue, as well as the cytokine IL-1β level. This anti-inflammatory activity was also accompanied by significant anti-hypersensitive effect. The effects presented by EuL seem not to be correlated with an antioxidant activity. However other extract chemical compounds could be responsible for its important anti-inflammatory effects., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
26. Salt-induced thermal gelation of xyloglucan in aqueous media.
- Author
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Sakakibara CN, Sierakowski MR, Ramírez RR, Chassenieux C, Riegel-Vidotti I, and de Freitas RA
- Abstract
The influence of Na
2 SO4 as a kosmotropic salt on the thermogelation of xyloglucan (XG) solutions was measured by rheology. The gelation occurred at lower temperatures and shorter times when the salt concentration was increased above 0.5 mol.L-1 . For Na2 SO4 concentrations equal to 1 mol.L-1 , a not thermoreversible elastic hydrogel was obtained. Salts containing various types of anions were used, and it was observed that SO4 2- , HPO4 2- and H2 PO4 - promoted the formation of a gelled network. The gel structure was observed using confocal laser scanning microscopy and scanning electron microscopy. In XG containing SO4 2 at 1 mol.L-1 aggregates and gels were formed by interconnected sub-micrometer XG particles. Increasing the concentration of SO4 2- led to conformation changes in the XG, from a twisted/helical to an extended/flat conformation, as observed using circular dichroism. The naturally occurring hydrophobic sequences promoted an economically feasible XG gelling that may produce thermo and kosmo-sensitive hydrogels., (Copyright © 2019 Elsevier Ltd. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
27. Influence of mechanical pretreatment to isolate cellulose nanocrystals by sulfuric acid hydrolysis.
- Author
-
Pirich CL, Picheth GF, Machado JPE, Sakakibara CN, Martin AA, de Freitas RA, and Sierakowski MR
- Subjects
- Cellulose analysis, Chemical Fractionation methods, Hydrolysis, Microscopy, Atomic Force, Nanoparticles analysis, Spectrum Analysis, Viscosity, Cellulose chemistry, Cellulose isolation & purification, Nanoparticles chemistry, Sulfuric Acids chemistry
- Abstract
The mechanical pretreatments intensities on characteristics of cellulose nanocrystals (CNC) prior to acid hydrolysis was evaluated. The cellulose was submitted to mechanical pretreatment as: magnetic stirring (CNC
st ), blending (CNCbl ) or grinding by 20 (CNC20x ) and 40 (CNC40x ) passages in a super mass colloid mill. Then, all samples were submitted to H2 SO4 hydrolysis and the CNC were evaluated by total mass yield (TMY%), rheological behavior, size distribution for width/length (WD), crystallinity index (CI%), OSO3 - substitution degree (SD) and zeta potential (ζ). After hydrolysis samples exhibited the same SD (190 ± 5 mMol·kg-1 ), ζ (-55 ± 3 mV) and CI% (65 ± 2), differing only in TMY% and WD. The CNCst showed TMY% of 85%, WD of 8 ± 5 nm and 100-800 nm, with presence of cellulose nanofibers (CNF), suggesting incomplete hydrolysis. The CNCbl and CNC20x revealed TMY% of 65 ± 1, but differed in WD of 8 ± 5 nm and 300 ± 200 nm and 8 ± 5 nm and 200 ± 170 nm, respectively. The results showed that the grinding mechanical pretreatment is mandatory for CNF isolation, but not for CNC. Stability profile after the hydrolytic procedure, CI%, morphology and similar character generated CNC with adequate features and good yield, by simple mechanical stirring or blending, reducing the production's cost and allowing industrial-scale production., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
28. Alternative sources of oils and fats from Amazonian plants: Fatty acids, methyl tocols, total carotenoids and chemical composition.
- Author
-
Serra JL, Rodrigues AMDC, de Freitas RA, Meirelles AJA, Darnet SH, and Silva LHMD
- Subjects
- Bertholletia chemistry, Carotenoids analysis, Fatty Acids, Unsaturated analysis, Lauric Acids, Linoleic Acid analysis, Oleic Acid analysis, Palmitic Acid analysis, Plant Oils analysis, Plants chemistry, Seeds chemistry, Tocopherols analysis, Fatty Acids analysis, Plant Oils chemistry
- Abstract
Amazonian plants possess high amounts of little-explored lipid compounds. Chemical parameters and lipophilic compounds present in twelve oils and fats from different Amazonian plants were characterized. The fatty acids identified reveal saturated fats, such as babassu oil and muru-muru fat (rich in lauric acid), ucuhuba fat (myristic acid), and bacuri fat (palmitic acid). Buriti, pracaxi, and patawa oils showed high oleic acid content. Passion fruit seed and Brazil nut oils had high levels of the polyunsaturated fatty acids rich in linoleic acid. The oleaginous plants had high unsaturation degree and high content of medium-length-chain fatty acids due to high values of iodine, saponification, and peroxide. For methyl tocols and total carotenes, a simultaneous determination method was used and revealed high levels of these vitamins in buriti oil. No previous work in the literature has described all these parameters in Amazonian oils and fats, especially regarding plant species such as bacuri, cupuassu, and ucuhuba. These results provide information on oils and fats that could be used as alternative sources of raw material for the food and pharmaceutics industries., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
29. Residual Risk After Tetralogy of Fallot Repair.
- Author
-
de Freitas RA
- Subjects
- Child, Heart, Humans, Pulmonary Valve Insufficiency, Tetralogy of Fallot
- Published
- 2019
- Full Text
- View/download PDF
30. Simple and effective purification approach to dissociate mixed water-insoluble α- and β-D-glucans and its application on the medicinal mushroom Fomitopsis betulina.
- Author
-
de Jesus LI, Smiderle FR, Cordeiro LMC, de Freitas RA, Van Griensven LJLD, and Iacomini M
- Subjects
- Carbohydrate Sequence, Solubility, Stereoisomerism, Coriolaceae chemistry, Glucans chemistry, Water chemistry
- Abstract
Differences in anomericity and in the branching degree of glucans lead to characteristic intermolecular association that influences their solubility in water or other solvents. A simple purification approach, based on the glucan solubility in aq. 0.1 M NaOH solution, was applied for the separation of mixed water-insoluble α-D-glucans from β-D-glucans extracted from fruiting bodies of Fomitopsis betulina, which is an underexploited medicinal mushroom. The results indicated that the β-D-glucan is constituted by (1→3)-linked β-D-Glcp units substituted at O-6 by non-reducing β-D-Glcp and (1→6)-linked β-D-Glcp units, while the α-D-glucan has a linear (1→3)-linked glucan structure. Thus, the 0.1 M NaOH treatment proved to be a simple, efficient and low-cost purification method for separation of water-insoluble glucans with different anomeric configurations and degree of branching that were interacting by intermolecular forces., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
31. Sand fly fauna (Diptera: Psychodidae) from Serra da Mocidade Nacional Park: report of vectors and putative vectors of American cutaneous leishmaniasis and new records for the state of Roraima, Brazil.
- Author
-
Ramos WR, De Oliveira AFJ, De Freitas RA, Alves VR, and Cordeiro DP
- Subjects
- Animals, Brazil, Female, Insect Vectors, Phlebotomus, United States, Leishmaniasis, Cutaneous, Psychodidae
- Abstract
Phlebotomine sand flies are insects of medical importance, as they are vectors of viruses, bacteria and trypanosomatids of the genus Leishmania Ross, the causative agent of leishmaniasis (Forattini 1973). During the past 20 years approximately 500,000 cases of leishmaniasis have been reported in Brazil. Most of these cases were reported in the North and Northeast regions. In the State of Roraima, almost 2,000 cases, including both cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL), have been reported during the past three years (SINAN 2017). Usually the transmission by infected female sand flies occurs in wild or rural areas, but there have also been recorded cases and vector captures in urban environments. Some sand fly species are known to enter houses in search of resting places and blood meal sources; as a result of this behavior, they are remarkably adaptable to new environments (Carvalhoet al. 2010).
- Published
- 2018
- Full Text
- View/download PDF
32. Modification of ulvans via periodate-chlorite oxidation: Chemical characterization and anticoagulant activity.
- Author
-
de Carvalho MM, de Freitas RA, Ducatti DRB, Ferreira LG, Gonçalves AG, Colodi FG, Mazepa E, Aranha EM, Noseda MD, and Duarte MER
- Subjects
- Anticoagulants chemistry, Chlorides chemistry, Dose-Response Relationship, Drug, Molecular Conformation, Oxidation-Reduction, Periodic Acid chemistry, Polysaccharides chemistry, Anticoagulants pharmacology, Blood Coagulation Factors antagonists & inhibitors, Chlorides pharmacology, Periodic Acid pharmacology, Polysaccharides pharmacology
- Abstract
Native (F2) and carboxyl-reduced (R) ulvans from Ulva fasciata were sequentially oxidized with periodate-chlorite affording the polycarboxyl ulvans C1, C2 and C3 (1.20, 1.41 and 1.81 mmol g
-1 of COOH, respectively; 19.7, 21.3 and 21.0% of NaSO3 , respectively) and R-C3 (1.86 mmol g-1 of COOH; NaSO3 = 22.7%), respectively. APTT assay (polysaccharide fractions at 150 μg mL-1 ) showed clotting time of 45.6 s for F2 fraction. For polycarboxyl ulvans C1, C2, C3 and R-C3 the clotting times were 101.0, 122.2, 222.0 and 227.0 s, respectively. Comparison of the APTT assay results using ulvans chemically modified by carboxyl-reduction, desulfation, periodate oxidation and/or chlorite oxidation showed the anticoagulant activity of polycarboxyl ulvans is dependent of the sulfate groups present in the native polymer. In addition, the increase of the anticoagulant activity was accompanied by the increasing of the carboxyl groups and the content of this acidic substituent seems to be more important than its positioning., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
33. Engineered biomarkers for leprosy diagnosis using labeled and label-free analysis.
- Author
-
de Santana JF, da Silva MRB, Picheth GF, Yamanaka IB, Fogaça RL, Thomaz-Soccol V, Machado-de-Avila RA, Chávez-Olórtegui C, Sierakowski MR, de Freitas RA, Alvarenga LM, and de Moura J
- Subjects
- Adult, Animals, Biomarkers analysis, Female, Humans, Male, Mice, Mice, Inbred BALB C, Biosensing Techniques, Immunoassay, Leprosy diagnosis, Mycobacterium leprae isolation & purification, Quartz Crystal Microbalance Techniques
- Abstract
The biotechnological evolution towards the development of antigens to detect leprosy has been progressing. However, the identification of leprosy in paucibacillary patients, based solely on the antigen-antibody interaction still remains a challenge. The complexity of clinical manifestations requires innovative approaches to improve the sensitivity of assays to detect leprosy before the onset of symptoms, thus avoiding disabilities and contributing, indirectly, to reduce transmission. In this study, the strategies employed for early leprosy diagnosis were: i. using a phage-displayed mimotope (APDDPAWQNIFNLRR) which mimics an immunodominant sequence (PPNDPAWQRNDPILQ) of an antigen of Mycobacterium leprae known as Ag85B; ii. engineering the mimotope by adding a C-terminal flexible spacer (SGSG-C); iii. conjugating the mimotope to a carrier protein to provide better exposure to antibodies; iv. amplifying the signal using biotin-streptavidin detection system in an ELISA; and v. coating the optimized mimotope on a quartz crystal microbalance (QCM) sensor for label-free biosensing. The ELISA sensitivity increased up to 91.7% irrespective of the immunological profile of the 132 patients assayed. By using comparative modeling, the M. tuberculosis Ag85B was employed as a template to ascertain which features make the mimotope a good antigen in terms of its specificity. For the first time, a sensitive QCM-based immunosensor to detect anti M. leprae antibodies in human serum was used. M. leprae antibodies could also be detected in the sera of paucibacillary patients; thus, the use of a mimotope-derived synthetic peptide as bait for antibodies in a novel analytical label-free immunoassay for leprosy diagnosis exhibits great potential., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
34. Effect of surface and porosity of biochar on water holding capacity aiming indirectly at preservation of the Amazon biome.
- Author
-
Batista EMCC, Shultz J, Matos TTS, Fornari MR, Ferreira TM, Szpoganicz B, de Freitas RA, and Mangrich AS
- Abstract
As part of efforts to reduce pressure on the Amazon and other biomes, one approach considered by Brazilian authorities and scientists is more intensive use of the soils of the interior of the northeast of the country, which are generally sandy, with low contents of organic matter and low water holding capacity and are frequently affected by severe droughts. In this work, biochars produced from waste biomasses were tested for the improvement of these soils. The highest BET (Brunauer-Emmett-Teller) specific surface areas were observed for all biochars. In the pH range studied, the water hyacinth plants (WH) sample showed the most negative zeta potentials, as well as the highest water holding capacity (WHC) values, while the zeta potentials of two quartzarenic neosol soils were consistent with their WHC values. The results suggested that despite the effect of porosity on water retention, the zeta potential could be associated with the presence of negative charges by which hydrated cationic counterions were absorbed and retained. The surface energy and its polar and dispersive components were associated with water retention, with sugar cane bagasse, orange peel, and water hyacinth biochars presenting higher SE values and larger polar components.
- Published
- 2018
- Full Text
- View/download PDF
35. Physicochemical and immunological characterization of chitosan-coated bacteriophage nanoparticles for in vivo mycotoxin modeling.
- Author
-
de Andrade CYT, Yamanaka I, Schlichta LS, Silva SK, Picheth GF, Caron LF, de Moura J, de Freitas RA, and Alvarenga LM
- Subjects
- Animals, Bacteriophages immunology, Female, Mice, Peptide Library, Vaccines immunology, Aflatoxin B1 immunology, Bacteriophages chemistry, Chitosan analogs & derivatives, Nanoparticles chemistry, Vaccines chemistry
- Abstract
To propose a novel modeling of aflatoxin immunization and surrogate toxin conjugate from AFB1 vaccines, an immunogen based on the mimotope, (i.e. a peptide-displayed phage that mimics aflatoxins epitope without toxin hazards) was designed. The recombinant phage 3P30 was identified by phage display technology and exhibited the ability to bind, dose dependent, specifically to its cognate target - anti-AFB1 antibody. In immunization assay, the phage-displayed mimotope and its peptide chemically synthesized were able to induce specific anti-AFB1 antibodies, indicating the proof of concept for aflatoxin mimicry. Furthermore, the phage 3P30 was homogeneously coated with chitosan, which also provided a tridimensional matrix network for mucosal delivery. After intranasal immunization, chitosan coated phages improved specific immunogenicity compared to the free antigen. It can be concluded that affinity-selected phage may contribute to the rational design of epitope-based vaccines in a prospectus for the control of aflatoxins and possibly other mycotoxins, and that chitosan coating improved the vectorization of the vaccine by the mucosal route., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
36. Bacterial cellulose in biomedical applications: A review.
- Author
-
Picheth GF, Pirich CL, Sierakowski MR, Woehl MA, Sakakibara CN, de Souza CF, Martin AA, da Silva R, and de Freitas RA
- Subjects
- Diagnosis, Humans, Regenerative Medicine, Bacteria metabolism, Biocompatible Materials chemistry, Biocompatible Materials metabolism, Biocompatible Materials pharmacology, Cellulose biosynthesis, Cellulose chemistry, Cellulose pharmacology
- Abstract
Bacterial cellulose (BC) derived materials represents major advances to the current regenerative and diagnostic medicine. BC is a highly pure, biocompatible and versatile material that can be utilized in several applications - individually or in the combination with different components (e.g. biopolymers and nanoparticles) - to provide structural organization and flexible matrixes to distinct finalities. The wide application and importance of BC is described by its common utilization as skin repair treatments in cases of burns, wounds and ulcers. BC membranes accelerate the process of epithelialization and avoid infections. Furthermore, BC biocomposites exhibit the potential to regulate cell adhesion, an important characteristic to scaffolds and grafts; ultra-thin films of BC might be also utilized in the development of diagnostic sensors for its capability in immobilizing several antigens. Therefore, the growing interest in BC derived materials establishes it as a great promise to enhance the quality and functionalities of the current generation of biomedical materials., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
37. Xyloglucan gelation induced by enzymatic degalactosylation; kinetics and the effect of the molar mass.
- Author
-
Sakakibara CN, Sierakowski MR, Chassenieux C, Nicolai T, and de Freitas RA
- Abstract
Gelation kinetics of aqueous solutions of xyloglucan (XG) extracted from H. courbaril seeds were investigated, in-situ, during enzymatic removal of galactose units by oscillatory shear rheological measurements, at different XG and enzyme (β-galactosidase) concentrations. Increasing the enzyme concentration (C
enz ) led to an increase of the gelation rate. Master curves of the evolution of the storage shear modulus at different Cenz could be formed by time-Cenz superposition showing that Cenz influenced the kinetics, but not the gelation process and the final gel stiffness. The behaviour of gels formed by XG with different molar mass (Mw ), prepared by endoglucanase hydrolysis, was evaluated as a function of the temperature. It was found that cooling led to a decrease of the crosslink density causing a decrease of the gel stiffness. The decrease of the crosslink density was sufficient to depercolate the network formed by relatively small XG with Mw =105 gmol-1 , but gels formed by XG with Mw ≥8×105 gmol-1 persisted down to 10°C. It is shown that the melting temperature and the gel stiffness at high temperatures can be controlled independently by varying the molar mass and the concentration of XG chains., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
- Full Text
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38. Increased O-Linked N-Acetylglucosamine Modification of NF-ΚB and Augmented Cytokine Production in the Placentas from Hyperglycemic Rats.
- Author
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Dela Justina V, Gonçalves JS, de Freitas RA, Fonseca AD, Volpato GT, Tostes RC, Carneiro FS, Lima VV, and Giachini FR
- Subjects
- Animals, Female, Fetal Growth Retardation etiology, Placenta physiopathology, Pregnancy, Pregnancy Complications, Protein Processing, Post-Translational, Rats, Acetylglucosamine metabolism, Cytokines metabolism, Hyperglycemia metabolism, NF-kappa B metabolism, Placenta metabolism
- Abstract
Inflammation as a result of NF-κB activation may result from the classical (canonical) pathway, with disconnection of the IκB inhibitor and subsequent nuclear translocation or, alternatively, by post-translational modifications of modulatory proteins or NF-κB subunits (non-canonical pathway). We hypothesized that hyperglycemia-induced increased glycosylation with O-linked N-acetylglucosamine (O-GlcNAc) of NF-κB in placental tissue leads to augmented production of pro-inflammatory cytokines, culminating in placental dysfunction and fetal restriction growth. Single injections of streptozotocin (40 mg/kg) or vehicle were used to induce hyperglycemia or normoglycemia, respectively, in female Wistar rats. After 3 days, rats were mated and pregnancy confirmed. Placental tissue was collected at 21 days of pregnancy. Placental expression of p65 subunit was similar between groups. However, nuclear translocation of p65 subunit, showing greater activation of NF-κB, was increased in the hyperglycemic group. Reduced expression of IκB and increased expression of phosphorylated IκB
Ser32 were observed in the placenta from hyperglycemic rats, demonstrating increased classical NF-κB activation. Augmented modification of O-GlcNAc-modified proteins was found in the placenta from hyperglycemic rats and p65 subunit was a key O-GlcNAc target, as demonstrated by immunoprecipitation. Tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) expressions were increased in the placenta from hyperglycemic rats. Furthermore, placental weight was increased, whereas fetal weight was decreased under hyperglycemic conditions. TNF-α and IL-6 demonstrated positive correlations with placental weight and negative correlations with fetal weight and placental efficiency. Therefore, under hyperglycemic conditions, a modulatory role of O-GlcNAc in NF-κB activity was demonstrated in the placenta, contributing to fetal and placental dysfunction due to inflammatory cytokine exacerbation.- Published
- 2017
- Full Text
- View/download PDF
39. Polysaccharide depolymerization from TEMPO-catalysis: Effect of TEMPO concentration.
- Author
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Spier VC, Sierakowski MR, Reed WF, and de Freitas RA
- Subjects
- Catalysis, Oxidation-Reduction, Polymerization, Cyclic N-Oxides, Polysaccharides chemistry
- Abstract
Polysaccharide TEMPO-oxidation was monitored using automatic continuous online monitoring of polymerization reactions (ACOMP). The products of oxidation, obtained at different pHs (9, 7 and 5) and different concentrations of catalyst TEMPO, were evaluated by Automatic Continuous Mixing (ACM) and Size Exclusion Chromatography (SEC). The degree of oxidation was higher at pH 9 and polysaccharide degradation was observed under different pH conditions, but was much higher without catalyst TEMPO. The rate constant (k) was dependent on reaction pH and TEMPO concentration. The amount of -COOH per g of polysaccharide, at pH 9, in the presence and absence of TEMPO was different, 0.215 and 0.395mmolg
-1 , respectively. This suggested a secondary and non-selective polysaccharide oxidation occurring at a lower rate in the absence of catalyst. TEMPO protects the polysaccharide from degradation caused by secondary oxidant species, acting as a catalyst and "sacrificial molecule" at higher concentrations., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
40. Piezoelectric immunochip coated with thin films of bacterial cellulose nanocrystals for dengue detection.
- Author
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Pirich CL, de Freitas RA, Torresi RM, Picheth GF, and Sierakowski MR
- Subjects
- Antibodies, Immobilized chemistry, Bacteria chemistry, Biosensing Techniques instrumentation, Cellulose chemistry, Dengue blood, Dengue virology, Equipment Design, Humans, Immunoassay instrumentation, Lab-On-A-Chip Devices, Nanoparticles ultrastructure, Viral Nonstructural Proteins analysis, Dengue diagnosis, Dengue Virus isolation & purification, Nanoparticles chemistry, Polysaccharides, Bacterial chemistry, Quartz Crystal Microbalance Techniques instrumentation, Viral Nonstructural Proteins blood
- Abstract
Low-cost piezoelectric devices, such as simple frequency monitoring quartz crystal microbalance (QCM) devices, have good clinical utility as fast diagnostic tools for the detection of several diseases. However, unspecific antigen recognition, poor molecular probe adsorption and the need for sample dilution are still common drawbacks that hinder their use in routine diagnosis. In this work, piezoelectric sensors were previously coated with thin films of bacterial cellulose nanocrystals (CN) to provide a more sensitive and adapted interface for the attachment of monoclonal immunoglobulin G (IgGNS1) and to favor specific detection of non-structural protein 1 (NS1) of dengue fever. The assembly of the immunochip surface was analyzed by atomic force microscopy (AFM) and the NS1 detection was followed by quartz crystal microbalance with (QCM-D) and without energy dissipation monitoring (QCM). The CN surface was able to immobilize 2.30±0.5mgm
-2 of IgGNS1, as confirmed by AFM topography and phase images along with QCM-D. The system was able to detect the NS1 protein in serum with only 10-fold dilution in the range of 0.01-10µgmL-1 by both QCM and QCM-D. The limits of detection of the two devices were 0.1μgmL-1 for QCM-D and 0.32μgmL-1 for QCM. As a result, QCM-D and QCM apparatuses can be used to follow NS1 recognition and have good potential for more sensitive, fast and/or less expensive diagnostic assays for dengue., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
41. Hepatoprotective effect of Maytenus robusta Reiss extract on CCl 4 -induced hepatotoxicity in mice and HepG2 cells.
- Author
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Thiesen LC, da Silva LM, Santin JR, Bresolin TMB, de Andrade SF, Amorim CM, Merlin L, de Freitas RA, Niero R, and Netz DJA
- Subjects
- Animals, Carbon Tetrachloride toxicity, Cell Survival drug effects, Hep G2 Cells drug effects, Humans, Mice, Antioxidants pharmacology, Chemical and Drug Induced Liver Injury prevention & control, Liver drug effects, Maytenus chemistry, Plant Extracts pharmacology, Plant Leaves chemistry, Protective Agents pharmacology
- Abstract
We investigated the hepatoprotective effect of methanolic extract from Maytenus robusta leaves in mice and HepG2 cells. The administration of CCl
4 in mice promoted a deep destruction of the histological lobular structure and increased the alanine aminotransferase (ALT) serum levels by 46.25% compared with the control group (p < 0.05). The M. robusta extract reduced the hepatic histological changes and normalization the ALT levels. The antioxidant effect of M. robusta in liver tissue promoted the reduction in 31.5% on lipoperoxides levels (p < 0.05), increased by 101.5% the reduced glutathione content (p < 0.05) and increased the activity of superoxide dismutase, catalase, and glutathione-S-transferase by 21.3% (p < 0.05), 49.3% (p < 0.05), and 27.6% (p < 0.05), respectively, compared with the vehicle group. Moreover, the extract reduced hepatic inflammation by diminishing myeloperoxidase activity, TNF and interleukin-6 levels by 29.4% (p < 0.05), 46.1% (p < 0.01), and 59.5% (p < 0.0001), respectively, compared with the vehicle group. The viability of HepG2 cells after incubation with CCl4 was 29.56± 3.07%, whereas the extract (300 μg/mL) restored the viability to 65.27± 8.75% and aspartate aminotransferase levels to 41.82 ± 4.41 U/L. The extract scavenged DPPH (IC50 = 14.44 μg/mL) and ABTS (IC50 = 3.00 μg/mL) radicals and did not produce acute toxicity in mice at 2000 mg/kg. In conclusion, was confirmed the hepatoprotective potential of M. robusta by its antioxidant effects., (Copyright © 2017 Elsevier Inc. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
42. Brain Death: Knowledge of Future Brazilian Physicians.
- Author
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Dibo FHA, Gravena ÂAF, de Freitas RA, Dell'Agnolo CM, de Almeida Benguella E, Pelloso SM, and de Barros Carvalho MD
- Subjects
- Adult, Brazil, Cross-Sectional Studies, Female, Humans, Male, Young Adult, Brain Death diagnosis, Health Knowledge, Attitudes, Practice, Students, Medical
- Abstract
Background: Thousands of people die on the waiting list for transplants. The shortage of organs and tissues for transplantation is considered a serious global problem. Brain death (BD) is the main source of organs for transplantations., Objective: Given that BD is assessed by medical staff and that this diagnosis is ethically relevant, the goal of this work was to analyze the knowledge of 5th- and 6th-year medical students of Southern Brazil regarding the process of determining BD., Method: This observational, cross-sectional study was conducted between September 2013 and March 2014., Results: A total of 635 students participated in the study, with 337 (53.1%) from public and 298 (46.9%) from private schools. Approximately 333 (52.4%) attended the 6th year of the medical program. The mean age of the students was 25.4 ± 3.56 years, with a prevalence of females of 54.6% (347) and a prevalence of Catholic religion of 61.7% (392); 84.2% of the students reported not feeling confident performing the BD protocol. A low percentage (15.7%) correctly answered 75% or more of the questions about BD, a criterion used to determine sufficient knowledge of BD. Approximately 45% (282) of respondents were not able to identify the patients who were candidates for the BD protocol. Analyzing the medical students' knowledge at the end of the program can provide information about the quality of undergraduate education on the topic of determining BD., Conclusion: It was concluded that 5th- and 6th-year medical students of Paraná State have little knowledge about the BD protocol., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
43. T1 mapping in children and young adults with hypertrophic cardiomyopathy.
- Author
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Parekh K, Markl M, Deng J, de Freitas RA, and Rigsby CK
- Subjects
- Adolescent, Area Under Curve, Cardiomyopathy, Hypertrophic pathology, Cardiomyopathy, Hypertrophic physiopathology, Case-Control Studies, Child, Child, Preschool, Contrast Media administration & dosage, Female, Fibrosis, Humans, Hypertrophy, Left Ventricular pathology, Hypertrophy, Left Ventricular physiopathology, Image Processing, Computer-Assisted, Male, Myocardium pathology, Predictive Value of Tests, Prospective Studies, ROC Curve, Reproducibility of Results, Young Adult, Cardiomyopathy, Hypertrophic diagnostic imaging, Hypertrophy, Left Ventricular diagnostic imaging, Magnetic Resonance Imaging, Ventricular Function, Left
- Abstract
To assess the global and segmental left ventricular (LV) native T1 and extracellular volume fraction (ECV) in children and young adults with hypertrophic cardiomyopathy (HCM) compared to a control cohort. The study population included 21 HCM patients (mean 14.1 ± 4.6 years) and 21 controls (mean 15.7 ± 1.5 years). Native modified Look-Locker inversion recovery sequence was performed before and after contrast injection in 3 short axis planes. Global and segmental LV native T1 and ECV were quantified and compared between HCM patients and controls. Mean native T1 in HCM patients and controls was 1020.4 ± 41.2 and 965.6 ± 30.2 ms respectively (p < 0.0001). Hypertrophied myocardium had significantly higher native global T1 and global ECV compared to non-hypertrophied myocardium in HCM (p < 0.0001, = 0.14 and 0.048, = 0.01 respectively). In a subset of patients, ECV was higher in LV segments with LGE compared to no LGE (p < 0.0001). No significant correlation was identified between global native T1 and ECV and parameters of LV structure and function. Native T1 cut-off of 987 ms provided the highest sensitivity (95 %) and specificity (91 %) to separate HCM patients from controls. Global and segmental native T1 are elevated in HCM patients. LV segments with hypertrophy and/or LGE had higher ECV in a subset of HCM patients. LV native T1 and ECV do not correlate with parameters of LV structure and function. T1 in children and young adults may be used as a non-invasive tool to assess for HCM and related fibrosis., Competing Interests: The authors declare that they have no conflict of interest.
- Published
- 2017
- Full Text
- View/download PDF
44. Chitosan-coated microvesicles: Effect of polysaccharide-phospholipid affinity on decafluorobutane dissolution.
- Author
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Picheth GF, Pirich CL, Dos Santos LA, Camarozano AC, Sierakowski MR, Ocampos FM, Barison A, Kaminski GA, Pontarolo R, and de Freitas RA
- Subjects
- Phospholipids chemistry, Solubility, Ultrasonography, Chitosan chemistry, Contrast Media chemistry, Fluorocarbons chemistry, Microbubbles, Phosphatidylcholines chemistry
- Abstract
The stability of perfluorinated microvesicles is mainly determined by the presence of interfacial materials and their ability to hinder the gas component diffusibility into the bloodstream. The goal of this study is to increase the persistence of the gaseous-core by introducing chitosan-coated 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) microvesicles, reducing gas diffusion from microvesicles, and increasing for a long time ultrasonic signals. Our hypothesis was based on the irreversible adhesion of chitosan towards DSPC head groups observed in thin-films models. This affinity enhanced the stabilization of gaseous-core microvesicles, in which the polysaccharide effectively reduced the phospholipid phase transition enthalpy from 383±5.5Jmg(-1) for plain to 150±9.7Jmg(-1) for chitosan-coated microvesicles, providing a more stable structure that diminished the gaseous component lost and provided the persistence of intense (19)F-NMR signals after 48h, twice as long compared to plain samples. As a result, stronger and long-lasting ultrasonic signals were produced by the more stable chitosan-containing microvesicles, thus, presenting great potential to increase the diagnostic and therapeutic applications of perfluorocarbon carries., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
45. TEMPO-mediated oxidation on galactomannan: Gal/Man ratio and chain flexibility dependence.
- Author
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Sakakibara CN, Sierakowski MR, Lucyszyn N, and de Freitas RA
- Abstract
Guar (GG) and locust bean (LBG) galactomannans (GMs) oxidation at C-6 was performed with catalyst TEMPO, in which the reaction progress was monitored by consume of NaOH solution. The products were characterized by spectroscopic analysis, infrared, and (1)H-nuclear magnetic resonance, confirming the presence of aldehydes groups as intermediate of reaction to carboxylic acid. From high performance anion exchange chromatography with pulsed amperometric detection Man/Gal molar ratio was determined and demonstrated a preference to oxidize Man during the reaction on both GMs, following a first order kinetics of oxidation. The comparative macromolecular behavior of native and oxidized GMs was obtained through the analysis by high performance size exclusion chromatography, and the persistence length (Lp) was 6nm and 4nm to native LBG and GG, respectively. A more accessible OH-6 at mannose residue in LBG could be related with a two times faster reaction than GG. The selective oxidation with catalyst TEMPO proved to be efficient to increase the flexibility of the GMs during oxidation. Short reaction time and β-elimination process were mainly observed to LBG, probably due to a more favorable oxidation access to the polysaccharide main chain., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
46. Core-shell particles formed by β-lactoglobulin microgel coated with xyloglucan.
- Author
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Gtari W, Aschi A, Nicolai T, and de Freitas RA
- Subjects
- Chromatography, Gel, Hydrogen-Ion Concentration, Suspensions, Temperature, Gels chemistry, Glucans chemistry, Lactoglobulins chemistry, Xylans chemistry
- Abstract
Core-shell particles were formed by mixing in aqueous solution the neutral polysaccharide xyloglucan (XG) with microgels. The last one was obtained by heating the whey protein β-lactoglobulin (β-LG) in the presence of CaCl
2 . XG adsorbed spontaneously unto the microgels at pH<5.6. The amount of bound XG per protein was determined using a combination of centrifugation and size exclusion chromatography. It increased linearly with increasing XG concentration. The fraction of XG that adsorbed increased with decreasing pH. The formation of the XG shell inhibited large scale flocculation of the particles, that causes precipitation for naked microgels, close to their isoionic point. The thickness of the XG shell was estimated by measurement of the hydrodynamic radius using dynamic light scattering. The extent of binding depended on the pH history during mixing showing that the protein/XG complex was not in thermodynamic equilibrium., (Copyright © 2016 Elsevier B.V. All rights reserved.)- Published
- 2016
- Full Text
- View/download PDF
47. Hydrophilicity improvement of mercerized bacterial cellulose films by polyethylene glycol graft.
- Author
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da Silva R, Sierakowski MR, Bassani HP, Zawadzki SF, Pirich CL, Ono L, and de Freitas RA
- Subjects
- Animals, Cell Line, Materials Testing, Mice, Molecular Weight, Nanostructures chemistry, Polymerization, Bacteria chemistry, Cellulose chemistry, Hydrophobic and Hydrophilic Interactions, Polyethylene Glycols chemistry
- Abstract
In this work, polyethylene glycol (PEG), of tree distinct molar masses (200, 300 and 400 g mol(-1)), was grafted onto mercerized bacterial nanocellulose (BNCm) and applied to produce nanofilms (BNCm-PEG). The products BNCm-PEG were characterized by NMR and thermal analysis. Solid-state NMR and X-ray diffraction analyses exhibited no significant differences in index of BNCm-PEG derivatives compared to BNCm, indicating that grafting reaction did not modify the BNCm crystalline structure. The apparent contact angle of the films showed that BNCm-PEG films exhibited a pronounced increase in the polar components (BNCm: 8.1 mN m(-1) vs BNCm-PEG400: 29.4 mN m(-1)), and a decrease in dispersive components (BNCm: 41.7 mN m(-1) vs BNCm-PEG400: 35.2 mN m(-1)) of the surface free energy. The BNCm-PEG films were more hydrophilic than BNCm and retained the biocompatibility with L929 fibroblast cells culture., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
48. Layer-by-layer polysaccharide-coated liposomes for sustained delivery of epidermal growth factor.
- Author
-
Kaminski GA, Sierakowski MR, Pontarolo R, Santos LA, and de Freitas RA
- Subjects
- Delayed-Action Preparations, Drug Liberation, Galactose analogs & derivatives, Kinetics, Quaternary Ammonium Compounds chemistry, Epidermal Growth Factor administration & dosage, Epidermal Growth Factor chemistry, Liposomes chemistry, Mannans chemistry, Polysaccharides, Bacterial chemistry
- Abstract
A three-dimensional layer-by-layer (LbL) structure composed by xanthan and galactomannan biopolymers over dioctadecyldimethylammonium bromide (DODAB) liposome template was proposed and characterized for protein drug delivery. The polymers and the surfactant interaction were sufficiently strong to create a LbL structure up to 8 layers, evaluated using quartz crystal microbalance (QCM) and zeta potential analysis. The polymer-liposome binding enthalpy was determined by isothermal titration calorimetry (ITC). The bilayer of biopolymer-coated liposomes with diameters of 165 (±15)nm, measured by dynamic light scattering (DLS), and ζ-potential of -4 (±13)mV. These bilayer-coated nanoparticles increased up to 5 times the sustained release of epidermal growth factor (EGF) at a first order rate of 0.005min(-1). This system could be useful for improving the release profile of low-stability drugs like EGF., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
49. Stabilization of Water-in-Water Emulsions by Polysaccharide-Coated Protein Particles.
- Author
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de Freitas RA, Nicolai T, Chassenieux C, and Benyahia L
- Subjects
- Emulsions, Fluorescein-5-isothiocyanate, Gels, Hydrogen-Ion Concentration, Rhodamines, Surface Tension, Water chemistry, Amylopectin chemistry, Glucans chemistry, Lactoglobulins chemistry, Xylans chemistry
- Abstract
The phase diagram of mixtures of xyloglucan (XG) and amylopectin (AMP) in aqueous solution is presented. Water-in-water emulsions prepared from mixtures in the two-phase regime were studied in detail, and the interfacial tension was determined. It is shown that the emulsions can be stabilized by addition of β-lactoglobulin microgels (βLGm), but only at pH ≤ 5.0. Excess βLGm preferentially entered the AMP phase at pH > 5.0 and the XG phase at lower pH. The inversion was caused by adsorption of XG onto βLGm that started below pH 5.5. It is shown that modification of the surface of particles by coating with polysaccharides is a potential lever to control stabilization of water-in-water emulsions.
- Published
- 2016
- Full Text
- View/download PDF
50. Time-dependent viscometry study of endoglucanase action on xyloglucan: A real-time approach.
- Author
-
Spier VC, Sierakowski MR, Ibrahim AT, Scholze Baum JC, Silveira JL, and de Freitas RA
- Subjects
- Chromatography, Hydrolysis, Time Factors, Viscosity, Cellulase chemistry, Glucans chemistry, Xylans chemistry
- Abstract
Hydrolysis of xyloglucan from Tamarindus indica and Hymenaea courbaril seeds with endoglucanase (EGII), which randomly breaks the (1→4)-linked β-glycosidic bonds of the polymer chain, was monitored in real time using time-dependent viscometry analysis (TDV). For both samples there was a decrease in the intrinsic viscosity ([η]), viscosity average molar mass (Mv), radius de gyration (Rg) and persistence length (Lp) immediately after the addition of the enzyme. It was observed the formation of oligosaccharides and oligomers composed of ∼2 units, up to 140min. Galactose-containing side chains two positions away from the non-substituted glucose, modulated the action of EGII, and the complete hydrolysis of the XG oligomers occurred after 24h. The results demonstrate for the first time the real-time degradation of xyloglucan as well the macromolecular and oligosaccharide composition during the EGII hydrolysis process., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
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