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15 result(s) for "Almeida, Matheus Rogério"
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A protocol for rapid monocyte isolation and generation of singular human monocyte-derived dendritic cells
The monocyte-derived dendritic cells (moDCs) are a subset of dendritic cells widely used in immunological studies as a convenient and easy approach after isolation of mononuclear cells directly from peripheral blood mononuclear cells (PBMC). Both the purification and cell culture of monocytes impact on the differentiation of monocytes into moDCs. The methodology to isolate and differentiate monocytes into moDCs is still controversial. We aimed to compare three different protocols for monocyte isolation from PBMC: 1) Cold-aggregation; 2) Percoll gradient; and 3) Magnetic beads cell-enrichment. Additionally we also compared four different monocyte differentiation and culture techniques: 1) Cell culture media; 2) Serum sources; 3) required GM-CSF and IL-4 concentrations; 4) Cell culture systems. We used flow cytometry analysis of light scattering and/or expression of pan surface markers, such as CD3, CD14 and CD209 to determine isolation/differentiation degree. Purified PBMC followed by two steps of cold aggregation, yielded cell viability around 95% with poor monocyte enrichment (monocytes increase vs. lymphocytes reduction was not statistically significant, p>0.05). Conversely, monocyte isolation from PBMC with discontinuous Percoll gradient generated around 50% cell viability. Albeit, we observed a significant reduction (p≤0.05) of lymphocytes contaminants. The magnetic beads cell-enrichment yield cell viability higher than 95%, as high as a significant lymphocyte depletion (p≤0.005) when compared to all other techniques employed. The moDCs showed better differentiation based on increased CD209 expression, but lower CD14 levels, when cells were cultured in RPMI medium plus 500IU/mL of both GM-CSF and IL-4 in a semi-adherent fashion. Serum sources showed no influence on the culture performance. In conclusion, the magnetic beads cell-enrichment showed superior cell viability, indicating that this approach is a better choice to isolate monocytes, and moDCs cultured afterwards in appropriate medium, serum, cytokines and culture system might influence the monocytes differentiation into moDC.
Advancing leprosy risk prediction through identification of a whole blood host transcriptomic biomarker signature including non-coding genes
Leprosy is a debilitating disease that requires early detection for effective control, yet diagnosis still relies on clinical signs. Previous RNA-Seq analysis of coding genes from leprosy patients’ household contacts (HHC) who developed leprosy (progressors) and those who did not, revealed a 4-gene RNA signature, RISK4LEP, that predicted leprosy 4–61 months before clinical onset (AUC: 0.86). To improve this signature, the present study included non-coding genes and applied novel Differential Gene Expression (DGE) analyses and machine learning approaches to the RNA-Seq dataset. This strategy identified significant DGE between progressors and HHC for 40 genes. Next, the 10 most significantly different expressed genes, as well as genes from the optimal 3-gene signatures, were validated by RT-qPCR in an independent cohort. This analysis confirmed the diagnostic potential to discriminate progressors from HHC for 12 genes. Moreover, RPS21 and SNHG5 genes were each significantly higher expressed in progressors compared to diagnosed leprosy patients, suggesting their temporary role during early (preclinical) leprosy. Furthermore, the optimal 3-gene signature consisted of two non-coding genes and one coding gene ( SNHG5 , SNHG8 , C6orf48 ; sensitivity: 88%; specificity: 88%; AUC: 0.96). This study thus identified an improved prospective host transcriptional risk signature in blood based on non-coding genes predicting the development of leprosy.
Proteomic and transcriptomic host biomarkers for detection of pleural tuberculosis
Current diagnosis of pleural tuberculosis (PLTB) is based on highly invasive procedures. Therefore, blood-based host biomarkers could represent a low-invasive diagnostic alternative. Plasma and pleural effusion, as well as blood-and pleural fluid mononuclear cells (PBMCs and PFMCs), were sampled from patients with PLTB and other pleural diseases (OPLDs). In pleural effusion, ApoA1, C1q, CRP, IL-6, IFN-γ, IP-10, MIG, S100A12, SAA1/A2, and serpin-A3 were significantly higher in PLTB compared to OPLD, whereas only SAA1/A2 showed discriminatory potential in plasma. Increased mRNA levels were observed in PFMCs of PLTB for CD8A, GBP5, SLAMF7, CXCL10, IL2, GNLY, IL23A, PDCD1 and BCMA, whereas HMOX1, CD163, DUSP3, IGF1, GUSB and MARCO were decreased. In PBMCs of PLTB, only CCL22 expression was decreased. GBP5 was significantly higher expressed in PLTB for both cell types. This study shows the potential of transcriptomic and proteomic host biomarkers to differentiate PLTB from OPLDs also when applying low-invasive methods.
Evaluation and validation of reference genes for RT-qPCR normalization in different sweet potato tissues
Sweet potato ( Ipomoea batatas ) is one of the most important crops of the world, displaying a significant economic importance in several countries. However, few studies exploring biotechnological tools, such as RT-qPCR, used for gene expression analysis, have been conducted so far, slowing down crop breeding programs. Here, a detailed analysis of previous validated reference genes, essential for normalization of RT-qPCR studies, was conducted, and new candidate genes were evaluated, addressing existing gaps for the development of molecular studies via RT-qPCR in sweet potato. To this end, five sweet potato reference genes studies were evaluated, and the six best-classified genes ( IbCYC , IbARF , IbTUB , IbUBI , IbCOX and IbEF1α ) were selected for further analysis. Additionally, four commonly used reference genes ( IbPLD , IbACT , IbRPL and IbGAP ) were also included in the study. The ten reference genes were analyzed across four different tissues (fibrous root, tuberous root, stem and leaf) from sweet potato plants grown under normal conditions. IbACT , IbARF and IbCYC were the most stable genes, displaying the lowest variation in expression levels across the tissues studied, while IbGAP , IbRPL and IbCOX were classified as the least stable genes according to the RefFinder algorithm. The results obtained here highlight the relevance of this type of investigation to ensure the reliability of relative gene expressions analyzed in sweet potato. In addition, it directly contributes for a better understanding of the biological processes associated with the performance of this crop, aiding future research addressing transcriptome analyses in this species, which displays high agricultural and industrial potential.
Essential Oil of Cymbopogon nardus (L.) Rendle: A Strategy to Combat Fungal Infections Caused by Candida Species
Background: The incidence of fungal infections, especially those caused by Candida yeasts, has increased over the last two decades. However, the indicated therapy for fungal control has limitations. Hence, medicinal plants have emerged as an alternative in the search for new antifungal agents as they present compounds, such as essential oils, with important biological effects. Published data demonstrate important pharmacological properties of the essential oil of Cymbopogon nardus (L.) Rendle; these include anti-tumor, anti-nociceptive, and antibacterial activities, and so an investigation of this compound against pathogenic fungi is interesting. Objective: The aim of this study was to evaluate the chemical composition and biological potential of essential oil (EO) obtained from the leaves of C. nardus focusing on its antifungal profile against Candida species. Methods: The EO was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Testing of the antifungal potential against standard and clinical strains was performed by determining the minimal inhibitory concentration (MIC), time-kill, inhibition of Candida albicans hyphae growth, and inhibition of mature biofilms. Additionally, the cytotoxicity was investigated by the IC50 against HepG-2 (hepatic) and MRC-5 (fibroblast) cell lines. Results: According to the chemical analysis, the main compounds of the EO were the oxygen-containing monoterpenes: citronellal, geranial, geraniol, citronellol, and neral. The results showed important antifungal potential for all strains tested with MIC values ranging from 250 to 1000 μg/mL, except for two clinical isolates of C. tropicalis (MIC > 1000 μg/mL). The time-kill assay showed that the EO inhibited the growth of the yeast and inhibited hyphal formation of C. albicans strains at concentrations ranging from 15.8 to 1000 μg/mL. Inhibition of mature biofilms of strains of C. albicans, C. krusei and C. parapsilosis occurred at a concentration of 10× MIC. The values of the IC50 for the EO were 96.6 μg/mL (HepG-2) and 33.1 μg/mL (MRC-5). Conclusion: As a major virulence mechanism is attributed to these types of infections, the EO is a promising compound to inhibit Candida species, especially considering its action against biofilm.
xRatSLAM: An Extensible RatSLAM Computational Framework
Simultaneous localization and mapping (SLAM) refers to techniques for autonomously constructing a map of an unknown environment while, at the same time, locating the robot in this map. RatSLAM, a prevalent method, is based on the navigation system found in rodent brains. It has served as a base algorithm for other bioinspired approaches, and its implementation has been extended to incorporate new features. This work proposes xRatSLAM: an extensible, parallel, open-source framework applicable for developing and testing new RatSLAM variations. Tests were carried out to evaluate and validate the proposed framework, allowing the comparison of xRatSLAM with OpenRatSLAM and assessing the impact of replacing framework components. The results provide evidence that the maps produced by xRatSLAM are similar to those produced by OpenRatSLAM when they are fed with the same input parameters, which is a positive result, and that implemented modules can be easily changed without impacting other parts of the framework.
Improved in vitro and in vivo Anti-Candida albicans Activity of Cymbopogon nardus Essential Oil by Its Incorporation into a Microemulsion System
Vulvovaginal candidiasis (VVC) is an opportunistic fungal infection that adversely affects a woman's health, due to unpleasant symptoms, therapeutic challenges, and the emergence of resistant strains. The association of natural products and nanotechnology is important to improve the antifungal potential of medicinal plants. We aimed to evaluate the in vitro and in vivo anti- activity of unloaded (EO) and loaded (ME+EO) essential oil of in the microemulsion (ME). The chemical analysis of the EO was performed by gas chromatography-mass spectrometry. The ME and ME+EO were characterized by scattering, zeta potential, polarized light microscopy, rheological assays, mucoadhesiveness and transmission electronic microscopy. The in vitro antifungal activity of the EO and ME+EO were evaluated by microdilution technique. The toxicity of EO and ME+EO was analyzed on human cell line HaCat and using alternative model assay with . The experimental in vivo VVC was performed in female mice (C57BL/6). The main compounds of the EO were found to be citronellal, geranial, geraniol, citronellol, and neral. The formulations exhibited suitable size, homogeneity, negative charge, isotropic behavior, highly organized structure, and pseudoplastic behavior, for vaginal application. TEM photomicrographs showed possible EO droplets inside the spherical structures. The EO, when loaded into the ME, exhibited an improvement in its antifungal action against . The EO was not toxic against brine shrimp nauplii. An in vivo VVC assay showed that the use of the ME significantly improved the action of the EO, since only the ME+EO promoted the eradication of the fungal vaginal infection on the third day of treatment. The EO and ME+EO are promising alternatives for the control of fungal infections caused by , once the use of nanotechnology significantly improved the antifungal action of the EO, especially in an in vivo model of VVC.
Standardized Brazilian green propolis extract (EPP-AF®) in COVID-19 outcomes: a randomized double-blind placebo-controlled trial
SARS-CoV-2 and its different variants caused a “wave and wave” pandemic pattern. During the first wave we demonstrated that standardized Brazilian green propolis extract (EPP-AF®) reduces length of hospital stay in adult patients with COVID-19. Afterwards, we decided to evaluate the impact of EPP-AF in hospitalized patients during the third wave of the pandemic. BeeCovid2 was a randomized, double-blind, placebo-controlled clinical trial in hospitalized COVID-19 adult patients. Patients were allocated to receive an oral dose of 900 mg/day of EPP-AF® or placebo for 10 days. The primary outcome was length of hospital stay. Secondary outcomes included safety, secondary infection rate, duration of oxygen therapy dependency, acute kidney injury and need for intensive care. Patients were followed up for 28 days after admission. We enrolled 188 patients; 98 were assigned to the propolis group and 90 to the placebo group. The post-intervention length of hospital stay was of 6.5 ± 6.0 days in the propolis group versus 7.7 ± 7.1 days in the control group (95% CI − 0.74 [− 1.94 to 0.42]; p  = 0.22). Propolis did not have significant impact on the need for oxygen supplementation or frequency of AKI. There was a significant difference in the incidence of secondary infection between groups, with 6.1% in the propolis group versus 18.9% in the control group (95% CI − 0.28 [0.1–0.76], p  = 0.01). The use of EPP-AF was considered safe and associated with a decrease in secondary infections. The drug was not associated with a significant reduction in length of hospital stay. ClinicalTrials.gov (NCT04800224).
Elucidating the adsorption mechanism of Rhodamine B on mesoporous coconut coir-based biosorbents through a non-linear modeling and recycling approach
The search for renewable adsorbent materials has increased continuously, being the agro-wastes an interesting alternative. This work aimed to elucidate the mechanism of adsorption of Rhodamine B on crude and modified coconut fibers from aqueous systems and the feasibility of reusing the biosorbents. The chemical modification of crude coconut fiber was carried out by the organosolv process. The biosorbents were characterized by lignocellulosic composition, FTIR, TGA, WCA, SEM, nitrogen adsorption/desorption (BET-BJH), and pH of zero point of charge (pH PZC ) analyses . The batch adsorption tests evaluated the effects of the adsorbent and adsorbate dosages, contact time, and temperature on Rhodamine B adsorption. For elucidating the adsorption mechanisms involved in the process, the non-linear forms of kinetic and isotherm models were used. The regeneration of the biosorbents was evaluated by carrying out the desorption experiments. Modified coconut fiber had an increase in the amount of α-cellulose, which influenced its structural, morphological, surface, and porous properties. The removal efficiency of Rhodamine B was about 90% for modified coconut fiber and 36% for crude coconut fiber. The dye adsorption was spontaneous and endothermic for both biosorbents, showing higher spontaneity and affinity with the adsorbate for biosorbent modified. Therefore, the coconut fiber can be considered an alternative to the traditional adsorbent materials that allows the reuse by four times without performance loss, in which its adsorptive capacity has increased through its chemical modification by a biorefinery process.
Flounder fish (Paralichthys sp.) collagen a new tissue regeneration: genotoxicity, cytotoxicity and physical–chemistry characterization
Collagen dressings have been widely used as effective treatments for chronic wounds acting as barrier, protecting the area from infections and participating in the healing process. Collagen from fish skin is biocompatible, presents low immunogenicity and is able of stimulating wound healing. In this scenario, skin of flounder fish (Paralichthys sp.) may constitute a promising source for collagen. Then, our hypothesis is that fish collagen is able of increasing cell proliferation, with no cytotoxicity. In this context, the aim of the present study was to investigate the physicochemical and morphological properties of collagen using scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), mass loss and pH. Moreover, the cytotoxicity and genotoxicity of collagen were studied using in vitro studies (cell viability, comet assay and micronucleus assay). Fish collagen showed no variation of pH and mass weight, with characteristic peaks of collagen in FTIR. Furthermore, all the extracts presented cell viability at least over 50% and no cytotoxicity was observed. Regarding genotoxicity data, the results showed that only the extract of 100% showed higher values in comparison with negative control group for CHO-K1 cell line as depicted by comet and micronucleus assays. Based on the results, it is suggested that fish collagen is biocompatible and present non-cytotoxicity in the in vitro studies, being considered a suitable material for tissue engineering proposals.