Abstract The molecular mechanisms underlying the cellular lost found in the nigrostriatal pathway during the progression of Parkinson's disease (PD) are not completely understood. Human neuroblastoma ...cell line SH-SY5Y challenged with 6-hydroxydopamine (6-OHDA) has been widely used as an in vitro model for PD. Although this cell line differentiates to dopaminergic neuron-like cells in response to low serum and retinoic acid (RA) treatment, there are few studies investigating the differences between proliferative and RA-differentiated SH-SY5Y cells. Here we evaluate morphological and biochemical changes which occurs during the differentiation of SH-SY5Y cells, and their responsiveness to 6-OHDA toxicity. Exponentially growing SH-SY5Y cells were maintained with DMEM/F12 medium plus 10% of fetal bovine serum (FBS). Differentiation was triggered by the combination of 10 µM RA plus 1% of FBS during 4, 7 and 10 days in culture. We found that SH-SY5Y cells differentiated for 7 days show an increase immunocontent of several relevant neuronal markers with the concomitant decrease in non-differentiated cell marker. Moreover, cells became two-fold more sensitive to 6-OHDA toxicity during the differentiation process. Time course experiments showed loss of mitochondrial membrane potential triggered by 6-OHDA (mitochondrial dysfunction parameter), which firstly occurs in proliferative than neuron-like differentiated cells. This finding could be related to the increase in the immunocontent of the neuroprotective protein DJ-1 during differentiation. Our data suggest that SH-SY5Y cells differentiated by 7 days with the protocol described here represent a more suitable experimental model for studying the molecular and cellular mechanisms underlying the pathophysiology of PD.
The recent Zika virus (ZIKAV) epidemics disclosed a major public health threat and a scientific and technological (S&T) challenge. The lessons learned from the S&T response of Latin America and the ...Caribbean (LAC) countries are critical to inform further research and guide scientific investments. The present study aimed to assess how new S&T knowledge produced and disseminated regionally can contribute to address global health challenges.
Scientometric and social network analysis methods were used to assess the LAC scientific contribution and potential technological development on ZIKAV up to December 2017. ZIKAV-related publications were retrieved from the Web of Science, Scopus, and PubMed databases. Regionally published articles were obtained from SciELO (Scientific Electronic Library Online) and LILACS (Literature in the Health Sciences in Latin America and the Caribbean) databases. Patent registries were retrieved using Orbit Intelligence and Derwent Innovation. Records from each database were individually downloaded, integrated, standardized and analyzed.
We retrieved 5421 ZIKAV-related publications, revealing a sharp increase from 2015 onwards. LAC countries accounted for 20% of all publications and Brazil was among the top three most central countries in the global network for ZIKAV research. A total of 274 patent families backed up by experimental evidence were retrieved. Only 5% were filed by LAC assignees, all of them based in Brazil. The largest contribution of LAC research was on the clinical manifestations of the ZIKAV infection, along with vector control, which was also the main focus of patents.
Our analysis offered a comprehensive overview of ZIKAV's research and development and showed that (i) LAC countries had a key role in generating and disseminating scientific knowledge on ZIKAV; (ii) LAC countries have expressively contributed to research on ZIKAV clinical manifestations; (iii) the Brazilian scientific community was potentially very effective in knowledge sharing and diffusion in the ZIKAV research network; (iv) Brazil was the single LAC country filing patents, mostly represented by independent inventors and low-tech patents. The paper advocates the need for a continued interdisciplinary approach to improve LAC countries ability to prevent, prepare for and control future outbreaks.
Sustainability indicators of the Brazil nut tree management Fernanda Lopes da Fonseca; Oscar José Rover; Lucia Helena de Oliveira Wadt ...
Revista Brasileira de Ciências Ambientais (Online),
12/2021, Letnik:
56, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Brazil nut tree (Bertholletia excelsa Bonpl) management, is a traditional activity that plays a key role in the economy of forestbased Amazon communities and in the conservation of ...forests. Nevertheless, some threats and critical points related to sustainability indicate to the need for establishment of monitoring procedures that can assist in the management of this natural resource. The overall aim of the research was to evaluate the MESMIS method as a tool to support the participatory definition of sustainability indicators to monitor Brazil nut management, and the viability of Brazil nut harvest over time. For that, we carried out a case study in the Porvir Community, RESEX Chico Mendes, Acre State (Brazil), aiming to integrate the perceptions of Brazil nut harvesters, researchers, managers, and technicians to define the indicators. The result was the generation of 18 strategic indicators to assess sustainability in the environmental, technical-economic and social dimensions. Assessment parameters, representing conditions that must be achieved for system sustainability, were collectively defined for each indicator. The main critical values attributed in the evaluation of the indicators are related to Brazil nut commercialization to intermediaries and oscillation in the annual fruit production. The use of the MESMIS method was considered appropriate to the studied context and can be recommended to similar non-timber forest product management systems.
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Malaria continues to be an important public health problem in the world. Nowadays, the widespread parasite resistance to many drugs used in antimalarial therapy has made the effective ...treatment of cases and control of the disease a constant challenge. Therefore, the discovery of new molecules with good antimalarial activity and tolerance to human use can be really important in the further treatment of the disease. In this study we have investigated the antiplasmodial activity of 10 synthetic compounds derived from quinoline, five of them combined to sulfonamide and five to the hydrazine or hydrazide group. The compounds were evaluated according to their cytotoxicity against HepG2 and HeLa cell lines, their antimalarial activity against CQ-sensitive and CQ-resistant Plasmodium falciparum strains and, finally, their schizonticide blood action in mice infected with Plasmodium berghei NK65. The compounds exhibited no cytotoxic action in HepG2 and HeLa cell lines when tested up to a concentration of 100μg/mL. In addition, the hydrazine or hydrazide derivative compounds were less cytotoxic against cell lines and more active against CQ-sensitive and CQ-resistant P. falciparum strains, showing high SI (>1000 when SI was calculated using the CC50 from the 3D7 strain as reference). When tested in vivo, the hydrazine derivative 1f compound showed activity against the development of blood parasites similar to that observed with CQ, the reference drug. Interestingly, the 1f compound demonstrated the best LipE value (4.84) among all those tested in vivo. Considering the in vitro and in vivo activities of the compounds studied here and the LipE values, we believe the 1f compound to be the most promising molecule for further studies in antimalarial chemotherapy.
Iron is essential for the proliferation of fungal pathogens during infection. The availability of iron is limited due to its association with host proteins. Fungal pathogens have evolved different ...mechanisms to acquire iron from host; however, little is known regarding how Paracoccidioides species incorporate and metabolize this ion. In this work, host iron sources that are used by Paracoccidioides spp. were investigated. Robust fungal growth in the presence of the iron-containing molecules hemin and hemoglobin was observed. Paracoccidioides spp. present hemolytic activity and have the ability to internalize a protoporphyrin ring. Using real-time PCR and nanoUPLC-MSE proteomic approaches, fungal growth in the presence of hemoglobin was shown to result in the positive regulation of transcripts that encode putative hemoglobin receptors, in addition to the induction of proteins that are required for amino acid metabolism and vacuolar protein degradation. In fact, one hemoglobin receptor ortholog, Rbt5, was identified as a surface GPI-anchored protein that recognized hemin, protoporphyrin and hemoglobin in vitro. Antisense RNA technology and Agrobacterium tumefaciens-mediated transformation were used to generate mitotically stable Pbrbt5 mutants. The knockdown strain had a lower survival inside macrophages and in mouse spleen when compared with the parental strain, which suggested that Rbt5 could act as a virulence factor. In summary, our data indicate that Paracoccidioides spp. can use hemoglobin as an iron source most likely through receptor-mediated pathways that might be relevant for pathogenic mechanisms.
Brazilian green propolis may be an alternative product that reduces the development of a microbial biofilm on the polymers used for maxillofacial prostheses. However, its effects as a disinfectant ...have not been fully established.
The purpose of this in vitro study was to investigate the effects of Brazilian green propolis alcohol solutions against the Staphylococcus aureus biofilm on polymers used in maxillofacial prostheses, the maxillofacial silicone elastomer (MDX4-4210), and specific acrylic resins for ocular prostheses.
A total of 324 disk-shaped specimens (3×10 mm) of each material were fabricated. All specimens were contaminated with S. aureus (108 cells/mL) to assess the antibiofilm activity of immersion solutions and protocols. Thus, 162 specimens of each material were randomly distributed and equally divided into 5 groups of disinfectants and 1 control group: 3 separate groups of 2.5%, 5%, and 10% propolis alcohol solutions, 1 group of 5% propolis alcohol gel, a positive control group of 2% chlorhexidine gluconate, and a negative control group of distilled water. Specimens (n=9) were disinfected by immersion for 5, 10, and 15 minutes and immersed in culture medium for 24 hours. Any notable turgescence in the final medium was considered indicative of a biofilm. The effects of disinfectants were analyzed by a turbidity assay and by scanning electron microscopy. Data were analyzed descriptively.
The final medium with specimens disinfected with 10% propolis alcohol solution showed no turbidity, indicating constant efficacy against the S. aureus biofilm. Similarly, these findings were observed in the 2% chlorhexidine gluconate group. Scanning electron microscopy images demonstrated that the surface of the polymers treated with 10% propolis alcohol solution did not show bacterial colonies.
Disinfection with 10% green propolis alcohol solution was effective in eliminating the S. aureus biofilm from specimens of maxillofacial elastomer and N1 acrylic resin specific to ocular prostheses by immersion for 5 minutes.
This work augments research on masting for the economically important tropical tree Carapa guianensis Aublet, specifically on whether determinants of mast years vary regionally, spatially, and due to ...longer term ENSO climate patterns. Longer term measurements (an 11-year period in Acre and Roraima; 4 years and 8 months in Amapá) from three regions of the Brazilian Amazon allowed for the analysis of whether climate cues were regionally consistent for this species. We used generalized linear mixed models, to determine which factors were significant in predicting whether trees would produce in a given year and to model the seed production quantity. We found a positive effect of increasing the diameter at breast height (dbh) on the quantity and likelihood of seed production. Our results also suggested that ecosystems and climate cues may jointly affect seed production. In flooded forests, increases in dry season rainfall had a negative impact on the likelihood of seed production whilst none of the precipitation variables investigated influenced the quantity of seeds produced. In drier terra firme forests in Acre with extended dry seasons, increases in dry season precipitation had significant and positive impacts on both the likelihood and the quantity of seed production. Our results illustrate the importance of considering plant habitat and climate to better understand individual and regional differences in seed production and their responses to inter-annual climate variation.
Mais de 95% da produção brasileira de castanha-da-amazônia é oriunda da coleta extrativista sendo poucos os plantios para produção comercial. Buscando contribuir com informações básicas para o ...melhoramento genético da castanheira, este estudo teve por objetivos: estimar os coeficientes de repetibilidade para o número de frutos (NFP); determinar o número adequado de medições para uma eficiente seleção de matrizes; e, selecionar castanheiras promissoras em dois castanhais nativos, no Estado do Acre. O estudo foi realizado em parcelas permanentes no Filipinas (Resex Chico Mendes, Epitaciolândia-AC) e Cachoeira (PAE Chico Mendes, Xapuri-AC). O número de frutos por planta (NFP) foi avaliado em 140 castanheiras no Filipinas, no período de 2002 a 2014 (13 anos), enquanto no Cachoeira foram 175 castanheiras de 2009 a 2014 (seis anos). As análises genético-estatísticas foram feitas com base na metodologia de modelos mistos, utilizando-se o software Selegen-REML/BLUP, Modelo 63. Foram selecionadas 20 matrizes, sendo 08 no Filipinas e 12 no Cachoeira. Em ambos os castanhais, a variância fenotípica permanente (Vfp) representou a maior porcentagem da variância fenotípica individual (Vf). O coeficiente de repetibilidade foi considerado moderado para o Cachoeira e alto para o Filipinas. Considerando um coeficiente de determinação de 90%, seriam necessários sete anos de avaliação do NFP para o Cachoeira e seis anos para o Filipinas. O banco de dados existentes para a produção de frutos das castanheiras é suficiente para se realizar a seleção de matrizes com alta produção de frutos. Com base nos valores estimados espera-se que a nova população apresente uma produção média de 465,3 frutos.arv-1, indicando um ganho na produção de frutos cerca de 2,4 vezes para o Cachoeira e 4,2 para o Filipinas.
Purpose
The objectives of this study were to determine if HIV-infected patients treated with highly active antiretroviral therapy (HAART), without dementia, suffer from longitudinal gray matter (GM) ...volume loss, changes in white matter (WM) integrity and deterioration in functional connectivity at rest, in an average interval of 30 months.
Methods
Clinically stable HIV-positive patients (on HAART, CD4 + T lymphocyte > 200 cells/μl, and viral loads <50 copies/μl) were recruited. None of them had HIV-associated dementia. Each patient underwent two scans, performed in a 1.5-T magnetic resonance imaging (MRI) scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of GM structures. WM integrity was assessed using tract-based spatial statistics to post-process diffusion tensor imaging data, and FMRIB's Software Library tools were used to post-process resting-state functional magnetic resonance imaging (RS-fMRI).
Results
There were no significant differences in cortical thickness, deep GM volumes, or diffusivity parameters between the scans at the two time points. Five resting-state networks were identified in our patients. In the second MRI, HIV-positive patients presented increased areas of functional connectivity in visual pathways, frontoparietal and cerebellar networks, compared with the first MRI (considering p < 0.05).
Conclusions
RS-fMRI revealed potentially compensatory longitudinal alterations in the brains of HIV-positive patients, attempting to compensate for brain damage related to the infection.
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