218 results on '"Leite AC"'
Search Results
2. Toxicity of sesame extracts to leaf-cutting ant Atta sexdens rubropilosa (Hymenoptera: Formicidae)
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Bueno, Oc, Bueno, Fc, Betella, G., Morini, Msc, Hebling, Mja, Pagnocca, Fc, Leite, Ac, Paulo Cezar Vieira, and Fernandes, Jb
3. Toxicity of Cipadessa fruticosa to the leaf-cutting ants Atta sexdens rubropilosa (Hymenoptera: Formicidae) and their symbiotic fungus
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Leite, Ac, Oliveira, Cg, Godoy, Mp, Bueno, Fc, Oliveira, Mdsd, Forim, MR, Fernandes, Jb, Paulo Cezar Vieira, Da Silva, Fdgf, Bueno, Oc, Pagnocca, Fc, Hebling, Mja, and Bacci, M.
4. Toxicity of Cedrela fissilis to Atta sexdens rubropilosa (Hymenoptera: Formicidae) and its symbiotic fungus
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Bueno, Fc, Godoy, Mp, Leite, Ac, Bueno, Oc, Pagnocca, Fc, Fernandes, Jb, Hebling, Mja, Bacci, M., Paulo Cezar Vieira, and Silva, Mfgf
5. NMR-based metabolomics analysis reveals the effect of environmental contamination exposure on fishermen living around the Mundaú Lagoon in Maceió (Alagoas, Brazil).
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Ursulino JS, Silva Filho RC, Rodrigues da Rocha Junior E, Crispim AC, Caldas Santos JC, Rezende Leite AC, and Mendonça de Aquino T
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- Brazil, Humans, Male, Environmental Monitoring, Magnetic Resonance Spectroscopy, Environmental Exposure statistics & numerical data, Adult, Principal Component Analysis, Mercury blood, Mercury urine, Middle Aged, Fisheries, Metabolomics, Water Pollutants, Chemical toxicity, Water Pollutants, Chemical analysis
- Abstract
The Mundaú lagoon in Maceió (Alagoas, Brazil) is a crucial resource for the local population, particularly fishing communities. Recent studies have revealed potential toxic metal contamination in the lagoon, particularly with mercury (Hg) levels exceeding the maximum regulated values. This inorganic contaminant may be impacting the health of fishermen and the local population. In this context, metabolomics, a study of small-molecule metabolites, can offer insights into the physiological impact of environmental contamination on humans. Thus, volunteers from the control and exposed groups were selected, considering the main exposure criteria primarily defined by their proximity and interaction with the lagoon. Blood and urine samples were collected from the volunteers and subjected to analysis using NMR spectroscopy. The data underwent Principal Component Analysis (PCA) and Orthogonal Partial Least-Squares Discriminant Analysis (OPLS-DA) based on metabolic patterns to establish group discrimination or identification. Metabolic pathways were assessed through enrichment analysis. The study revealed several metabolic disturbances in the exposed group's urine and plasma samples compared to control group. Noteworthy findings included arginine and proline metabolism disruptions, indicative of ammonia recycling and urea cycle impairment. These changes suggest compromised ammonia detoxification in the exposed group. Disturbances in the tricarboxylic acid (TCA) cycle and the transfer of acetyl groups into mitochondria suggested systemic metabolic stress in energy metabolism. Furthermore, elevated carnitine and ketone levels may indicate compensatory responses to low TCA cycle activity. Alterations in glutamate and glutathione metabolism and imbalances in glutathione levels indicate oxidative stress and impaired detoxification. This study highlights significant metabolic changes in fishermen exposed to contaminated environments, which can affect various metabolic pathways, including energy metabolism and antioxidant processes, potentially making individuals more vulnerable to the adverse effects of environmental contaminants. Finally, this work highlights insights into the relationship between environmental contamination and metabolic pathways, particularly in regions with limited studies., Competing Interests: Declaration of competing interest All the authors have no financial and personal relationships with other people or organizations that could inappropriately influence this work. The data that support the findings of this study are available from the corresponding author upon reasonable request., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
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- 2024
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6. Modulation of gene expression in skin wound healing by photobiomodulation therapy: A systematic review in vivo studies.
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Pilar EFS, Brochado FT, Schmidt TR, Leite AC, Deluca AA, Mármora BC, Siebert M, Wagner VP, and Martins MD
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- Animals, Humans, Cytokines metabolism, Gene Expression radiation effects, Gene Expression Regulation radiation effects, Matrix Metalloproteinase 2 metabolism, Matrix Metalloproteinase 2 genetics, Matrix Metalloproteinase 9 metabolism, Matrix Metalloproteinase 9 genetics, Low-Level Light Therapy, Skin metabolism, Skin radiation effects, Skin pathology, Skin injuries, Wound Healing radiation effects
- Abstract
Background: Wound healing is a multistep process involving coordinated responses of a variety of cell types, cytokines, growth factors, and extracellular matrix (ECM) components leading to the physiological restoration of tissue integrity. Photobiomodulation therapy (PBMT) has been highlighted as an approach to improve the healing process, nonetheless at the molecular level, the effects of PBMT are not entirely understood., Aim: To systematically review publications that investigated gene expression after PBMT during in vivo skin repair., Methods: An electronic search was undertaken in Medline Ovid (Wolters Kluwer), PubMed (National Library of Medicine), Web of Science (Thomson Reuters), Scopus (Elsevier), Embase, and LILACS databases. The search strategy was conducted from the terms: low-level light therapy, gene expression, and wound healing and their synonyms. The databases were consulted in December 2023 and no publication year limit was used., Results: Eleven studies were included in this review and the expression of 186 genes was evaluated. PBMT modified the expression of several targets genes studied, such as down-regulation of genes related to extracellular matrix proteases (MMP2 and MMP9) and pro-inflammatory cytokines (IL10 and IL6) and up-regulation of DNMT3A and BFGF., Conclusion: This review demonstrates that PBMT is capable of regulating gene expression during wound healing. Most evidence showed a positive impact of PBMT in regulating genes linked to inflammatory cytokines improving skin wound healing. Yet, the effects of PBMT in genes involved in other mechanisms still need to be better understood., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
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- 2024
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7. Discovery of 2,9-diaryl-6-carbamoylpurines as a novel class of antitubercular agents.
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Correia C, Leite AC, Fraga AG, Proença MF, Pedrosa J, and Carvalho MA
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- Animals, Antitubercular Agents pharmacology, Microbial Sensitivity Tests, Oxygen, Structure-Activity Relationship, Mammals, Mycobacterium tuberculosis, Tuberculosis drug therapy, Tuberculosis microbiology
- Abstract
A series of novel 9-alkyl/aryl-2-aryl-6-carbamoylpurines were synthesized, and their activity against Mycobacterium tuberculosis strain H
37 Rv was assessed. The SAR analysis on the first set of derivatives, with an alkyl or aryl unit at N-9 and a phenolic unit at C-2, showed that the activity depends on the purine ring substituents at N-9 and C-2. A phenyl group at N-9 combined with a 3-hydroxyphenyl or 4-hydroxyphenyl at C-2 improve the activity. The most active compound of this set has a phenyl group at N-9 and a 4-hydroxyphenyl group at C-2, displaying an IC90 = 1.2 μg/mL and a selectivity index higher than 25.5. This compound served as a Hit to design the second set of derivatives. A phenyl group at N-9 was maintained, and the group at C-2 was diversified. The SAR analysis showed that the aryl unit at C-2 must have an oxygen or nitrogen atom bonded in the para position. A proton, a small alkyl or a substituted aryl group may also be bonded to the oxygen. The compound with the 4-methoxyphenyl group at C-2, 1Bd, exhibits the highest activity with an IC90 < 0.19 μg/mL. This compound is highly potent against M. tuberculosis strain H37 Rv and non-toxic for VERO mammalian cells with an SI > 153.8. Compound 1Bd was also non-cytotoxic against primary macrophage cultures at IC90 , 2xIC90, and 10xIC90 and significantly reduced the bacterial load in M. tuberculosis-infected macrophages at the same concentrations. Compound 1Bd showed a favorable pharmacokinetic profile when administered orally, with major lung and liver accumulation. In vivo antimycobacterial efficacy of 1Bd was tested at 25 mg/kg. At the tested regimen, a decrease in bacterial burden was observed in the liver. Optimization of the treatment regimen should be performed to fully potentiate the in vivo efficacy of our lead molecule, particularly in the lung, the main target organ of M. tuberculosis., 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 © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)- Published
- 2024
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8. Electrical Fields in the Processing of Protein-Based Foods.
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Pereira RN, Rodrigues R, Avelar Z, Leite AC, Leal R, Pereira RS, and Vicente A
- Abstract
Electric field-based technologies offer interesting perspectives which include controlled heat dissipation (via the ohmic heating effect) and the influence of electrical variables (e.g., electroporation). These factors collectively provide an opportunity to modify the functional and technological properties of numerous food proteins, including ones from emergent plant- and microbial-based sources. Currently, numerous scientific studies are underway, contributing to the emerging body of knowledge about the effects on protein properties. In this review, "Electric Field Processing" acknowledges the broader range of technologies that fall under the umbrella of using the direct passage of electrical current in food material, giving particular focus to the ones that are industrially implemented. The structural and biological effects of electric field processing (thermal and non-thermal) on protein fractions from various sources will be addressed. For a more comprehensive contextualization of the significance of these effects, both conventional and alternative protein sources, along with their respective ingredients, will be introduced initially.
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- 2024
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9. Synthesis of hydrazinyl-thiazole ester derivatives, in vitro trypanocidal and leishmanicidal activities.
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Haroon M, Akhtar T, Mehmood H, da Silva Santos AC, da Conceição JM, Brondani GL, Silva Tibúrcio RD, Galindo Bedor DC, Viturino da Silva JW, Sales Junior PA, Alves Pereira VR, and Lima Leite AC
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- Thiazoles pharmacology, Esters pharmacology, Trypanosoma cruzi, Nitroimidazoles, Trypanocidal Agents pharmacology
- Abstract
Aim: To synthesize novel more potent trypanocidal and leishmanicidal agents. Methods: Hantzsch's synthetic strategy was used to synthesize 1,3-thiazole-4-carboxylates and their N -benzylated derivatives. Results: 28 new thiazole-carboxylates and their N -benzylated derivatives were established to test their trypanocidal and leishmanicidal activities. From both series, compounds 3b , 4f , 4g , 4j and 4n exhibited a better or comparable trypanocidal profile to benznidazole. Among all tested compounds, 4n was found to be the most potent and was better than benznidazole. Conclusion: Further variation of substituents around 1,3-thiazole-4-carboxylates and or hydrazinyl moiety may assist in establishing better and more potent trypanocidal and leishmanicidal agents.
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- 2024
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10. Thiazole, Isatin and Phthalimide Derivatives Tested in vivo against Cancer Models: A Literature Review of the Last Six Years.
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Pinto AF, Nunes JS, Severino Martins JE, Leal AC, Silva CCVC, da Silva AJFS, da Cruz Olímpio DS, da Silva ETN, Campos TA, and Lima Leite AC
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- Humans, Animals, Drug Screening Assays, Antitumor, Isatin chemistry, Isatin pharmacology, Isatin therapeutic use, Phthalimides chemistry, Phthalimides pharmacology, Phthalimides chemical synthesis, Antineoplastic Agents pharmacology, Antineoplastic Agents chemistry, Antineoplastic Agents chemical synthesis, Antineoplastic Agents therapeutic use, Neoplasms drug therapy, Neoplasms pathology, Thiazoles chemistry, Thiazoles pharmacology, Thiazoles therapeutic use, Thiazoles chemical synthesis
- Abstract
Background: Cancer is a disease characterized by the abnormal multiplication of cells and is the second leading cause of death in the world. The search for new effective and safe anticancer compounds is ongoing due to factors such as low selectivity, high toxicity, and multidrug resistance. Thus, heterocyclic compounds derived from isatin, thiazole and phthalimide that have achieved promising in vitro anticancer activity have been tested in vivo and in clinical trials., Objective: This review focused on the compilation of promising data from thiazole, isatin, and phthalimide derivatives, reported in the literature between 2015 and 2022, with in vivo anticancer activity and clinical trials., Methods: A bibliographic search was carried out in the PUBMED, MEDLINE, ELSEVIER, and CAPES PERIODIC databases, selecting relevant works for each pharmacophoric group with in vivo antitumor activity in the last 6 years., Results: In our study, 68 articles that fit the scope were selected and critically analyzed. These articles were organized considering the type of antitumor activity and their year of publication. Some compounds reported here demonstrated potent antitumor activity against several tumor types., Conclusion: This review allowed us to highlight works that reported promising structures for the treatment of various cancer types and also demonstrated that the privileged structures thiazole, isatin and phthalimide are important in the design of new syntheses and molecular optimization of compounds with antitumor activity., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
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- 2024
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11. Performance of the National Institute of Infectious Diseases disability scale in HTLV-1-associated myelopathy/tropical spastic paraparesis.
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Schmidt FR, Coutinho ES, Lima MA, Silva MT, Leite AC, Fonseca IO, and Araujo AQ
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- Humans, Reproducibility of Results, Quality of Life, Paraparesis, Tropical Spastic diagnosis, Human T-lymphotropic virus 1, Communicable Diseases
- Abstract
HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic disabling disease. However, there is a lack of an adequate and specific health measurement instrument validated and with good performance to assess their degree of physical disability. This led us to carry out this study and to evaluate the performance of Fiocruz's National Institute of Infectious Diseases (IDS) disability scale, a specific instrument for HAM/TSP. Ninety-two HAM/TSP patients participated in the study. One researcher applied the IDS, IPEC scale, Disability Status Scale (DSS), Expanded DSS (EDSS), Osame scale, Beck Depression Inventory, and the WHOQOL-BREF questionnaire. In parallel, blindly, and separately, other researchers applied the IDS. An inter-rater reliability analysis of the IDS, correlation analysis with the other scales, and depression and quality of life questionnaires were performed. The applicability of the IDS was also evaluated. The IDS showed high reliability in all scores. The inter-rater reliability test for the total IDS score was 0.94 (0.82-0.98) on its four dimensions. The scale adequately indicated the different degrees of disability, presenting a distribution similar to normal. There was a high correlation with the other scales (Spearman coefficients > 0.80, p < 0.001). The scale had good acceptance among users and a short application time. IDS for HAM/TSP was reliable, consistent, easy, and fast to use. It can be used for both prospective evaluations and clinical trials. The present study supports the IDS as a valid instrument to measure disability in patients with HAM/TSP compared to previously used scales., (© 2023. The Author(s) under exclusive licence to The Journal of NeuroVirology, Inc.)
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- 2023
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12. 1,3-Thiazole derivatives as privileged structures for anti-Trypanosoma cruzi activity: Rational design, synthesis, in silico and in vitro studies.
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Cox Holanda de Barros Dias M, Souza Barbalho M, Bezerra de Oliveira Filho G, Veríssimo de Oliveira Cardoso M, Lima Leite AC, da Silva Santos AC, Cristovão Silva AC, Accioly Brelaz de Castro MC, Maria Nascimento Moura D, Gomes Rebello Ferreira LF, Zaldini Hernandes M, de Freitas E Silva R, and Rêgo Alves Pereira V
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- Humans, Molecular Docking Simulation, Structure-Activity Relationship, Thiazoles chemistry, Drug Design, Trypanosoma cruzi, Trypanocidal Agents chemistry, Chagas Disease drug therapy
- Abstract
Chagas disease is a deadly and centenary neglected disease that is recently surging as a potential global threat. Approximately 30% of infected individuals develop chronic Chagas cardiomyopathy and current treatment with the reference benznidazole (BZN) is ineffective for this stage. We presently report the structural planning, synthesis, characterization, molecular docking prediction, cytotoxicity, in vitro bioactivity and mechanistic studies on the anti-T. cruzi activity of a series of 16 novel 1,3-thiazoles (2-17) derived from thiosemicarbazones (1a, 1b) in a two-step and reproducible Hantzsch-based synthesis approach. The anti-T. cruzi activity was evaluated in vitro against the epimastigote, amastigote and trypomastigote forms of the parasite. In the bioactivity assays, all thiazoles were more potent than BZN against epimastigotes. We found that the compounds presented an overall increased anti-tripomastigote selectivity (Cpd 8 was 24-fold more selective) than BZN, and they mostly presented anti-amastigote activity at very low doses (from 3.65 μM, cpd 15). Mechanistic studies on cell death suggested that the series of 1,3-thiazole compounds herein reported cause parasite cell death through apoptosis, but without compromising the mitochondrial membrane potential. In silico prediction of physicochemical properties and pharmacokinetic parameters showed promising drug-like results, being all the reported compounds in compliance with Lipinski and Veber rules. In summary, our work contributes towards a more rational design of potent and selective antitripanosomal drugs, using affordable methodology to yield industrially viable drug candidates., 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 Masson SAS. All rights reserved.)
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- 2023
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13. Mitochondria and the cell cycle in budding yeast.
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Leite AC, Costa V, and Pereira C
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- Mitochondria metabolism, Cell Division, Cell Cycle genetics, Saccharomyces cerevisiae metabolism, Saccharomycetales genetics, Saccharomycetales metabolism, Saccharomyces cerevisiae Proteins genetics, Saccharomyces cerevisiae Proteins metabolism
- Abstract
As centers for energy production and essential biosynthetic activities, mitochondria are vital for cell growth and proliferation. Accumulating evidence suggests an integrated regulation of these organelles and the nuclear cell cycle in distinct organisms. In budding yeast, a well-established example of this coregulation is the coordinated movement and positional control of mitochondria during the different phases of the cell cycle. The molecular determinants involved in the inheritance of the fittest mitochondria by the bud also seem to be cell cycle-regulated. In turn, loss of mtDNA or defects in mitochondrial structure or inheritance often lead to a cell cycle delay or arrest, indicating that mitochondrial function can also regulate cell cycle progression, possibly through the activation of cell cycle checkpoints. The up-regulation of mitochondrial respiration at G2/M, presumably to fulfil energetic requirements for progression at this phase, also supports a mitochondria-cell cycle interplay. Cell cycle-linked mitochondrial regulation is accomplished at the transcription level and through post-translational modifications, predominantly protein phosphorylation. Here, we address mitochondria-cell cycle interactions in the yeast Saccharomyces cerevisiae and discuss future challenges in the field., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
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14. Editorial: Precision control technology and application in agricultural pest and disease control.
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Tang Y, Chen C, Leite AC, and Xiong Y
- Abstract
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.
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- 2023
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15. The APC/C Activator Cdh1p Plays a Role in Mitochondrial Metabolic Remodelling in Yeast.
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Leite AC, Barbedo M, Costa V, and Pereira C
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- Proteomics, Ubiquitin-Protein Ligases metabolism, Saccharomyces cerevisiae metabolism, Saccharomyces cerevisiae Proteins metabolism, Cdh1 Proteins metabolism
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Cdh1p is one of the two substrate adaptor proteins of the anaphase promoting complex/cyclosome (APC/C), a ubiquitin ligase that regulates proteolysis during cell cycle. In this work, using a proteomic approach, we found 135 mitochondrial proteins whose abundance was significantly altered in the cdh1 Δ mutant, with 43 up-regulated proteins and 92 down-regulated proteins. The group of significantly up-regulated proteins included subunits of the mitochondrial respiratory chain, enzymes from the tricarboxylic acid cycle and regulators of mitochondrial organization, suggesting a metabolic remodelling towards an increase in mitochondrial respiration. In accordance, mitochondrial oxygen consumption and Cytochrome c oxidase activity increased in Cdh1p-deficient cells. These effects seem to be mediated by the transcriptional activator Yap1p, a major regulator of the yeast oxidative stress response. YAP1 deletion suppressed the increased Cyc1p levels and mitochondrial respiration in cdh1 Δ cells. In agreement, Yap1p is transcriptionally more active in cdh1 Δ cells and responsible for the higher oxidative stress tolerance of cdh1 Δ mutant cells. Overall, our results unveil a new role for APC/C-Cdh1p in the regulation of the mitochondrial metabolic remodelling through Yap1p activity.
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- 2023
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16. Mitochondrial respiration promotes Cdc37-dependent stability of the Cdk1 homolog Cdc28.
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Leite AC, Martins TS, Cesário RR, Teixeira V, Costa V, and Pereira C
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- Humans, Animals, CDC28 Protein Kinase, S cerevisiae genetics, CDC28 Protein Kinase, S cerevisiae metabolism, HSP90 Heat-Shock Proteins genetics, HSP90 Heat-Shock Proteins metabolism, Saccharomyces cerevisiae metabolism, Mitochondria genetics, Mitochondria metabolism, Protein Binding, Mammals metabolism, Chaperonins metabolism, CDC2 Protein Kinase genetics, CDC2 Protein Kinase metabolism, Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Molecular Chaperones metabolism
- Abstract
Cdc28, the homolog of mammalian Cdk1, is a conserved key regulatory kinase for all major cell cycle transitions in yeast. We have found that defects in mitochondrial respiration (including deletion of ATP2, an ATP synthase subunit) inhibit growth of cells carrying a degron allele of Cdc28 (cdc28td) or Cdc28 temperature-sensitive mutations (cdc28-1 and cdc28-1N) at semi-permissive temperatures. Loss of cell proliferation in the atp2Δcdc28td double mutant is associated with aggravated cell cycle arrest and mitochondrial dysfunction, including mitochondrial hyperpolarization and fragmentation. Unexpectedly, in mutants defective in mitochondrial respiration, steady-state protein levels of mutant cdc28 are strongly reduced, accounting for the aggravated growth defects. Stability of Cdc28 is promoted by the Hsp90-Cdc37 chaperone complex. Our results show that atp2Δcdc28td double-mutant cells, but not single mutants, are sensitive to chemical inhibition of the Hsp90-Cdc37 complex, and exhibit reduced levels of additional Hsp90-Cdc37 client kinases, suggesting an inhibition of this complex. In agreement, overexpression of CDC37 improved atp2Δcdc28td cell growth and Cdc28 levels. Overall, our study shows that simultaneous disturbance of mitochondrial respiration and Cdc28 activity reduces the capacity of Cdc37 to chaperone client kinases, leading to growth arrest., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)
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- 2023
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17. Outlining the Molecules Tested In Vivo for Chagas Disease, Malaria, and Schistosomiasis Over the Last Six Years - A Literature Review Focused on New Synthetic Drug Identities and Repurposing Strategies.
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de Melo Silva VG, da Conceição JM, Vieira Costa Silva CC, Leal AC, Araújo DL, Nunes JS, da Silva ETN, da Silva AJFS, de Barros Dias MCH, and Lima Leite AC
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- Humans, Drug Repositioning, COVID-19, Malaria drug therapy, Schistosomiasis drug therapy, Chagas Disease drug therapy
- Abstract
Background: COVID-19 disrupted NTD programs in 60% of countries, impairing public health goals. Thus, boosting NTD's research knowledge is demanding, and in vivo screening of candidates allows for the prospect of promising options based on their overall profile., Objective: In this work, we highlighted the relevant research done between 2015-2021 in the fields of synthetic and repurposed drugs that were tested in vivo for Chagas disease, malaria, and schistosomiasis., Methods: MEDLINE, PUBMED, CAPES PERIODIC, and ELSEVIER databases were used for a comprehensive literature review of the last 6 years of research on each area/disease., Results: Overall, research focused on nitro heterocyclic, aromatic nitro, nucleoside, and metal-based scaffolds for analogue-based drug generation. Repurposing was widely assessed, mainly with heterocyclic drugs, their analogues, and in combinations with current treatments. Several drug targets were aimed for Chagas treatment, specific ones such as iron superoxide dismutase, and more general ones, such as mitochondrial dysfunction. For malaria, hemozoin is still popular, and for schistosomiasis, more general structural damage and/or reproduction impairment were aimed at in vitro analysis of the mechanism of action., Conclusion: Latest in vivo results outlined trends for each disease - for Chagas Disease, heterocyclics as thiazoles were successfully explored; for Malaria, quinoline derivatives are still relevant, and for schistosomiasis, repurposed drugs from different classes outstood in comparison to synthetic compounds. This study uprises the continuous development of Chagas disease, malaria, and schistosomiasis drugs, providing researchers with tools and information to address such unmet therapeutic needs., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
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- 2023
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18. Identification of Novel Zika Virus Inhibitors: A Screening using Thiosemicarbazones and Thiazoles Templates.
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de Moraes Gomes PAT, Barros Freitas LA, Pessoa Siqueira LR, da Conceição JM, Dos Santos IR, Pinto AF, de Melo Silva VG, Nunes JS, de Oliveira Cardoso MV, Pena LJ, and Lima Leite AC
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- Humans, Antiviral Agents pharmacology, Antiviral Agents therapeutic use, Zika Virus, Microcephaly drug therapy, Thiosemicarbazones pharmacology, Zika Virus Infection epidemiology
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Background: Zika virus (ZIKV) remains an important cause of congenital infection, fetal microcephaly, and Guillain-Barré syndrome in the population. In 2016, WHO declared a cluster of microcephaly cases and other neurological disorders reported as a global public health emergency in Brazil. There is still no specific treatment for Zika virus fever, only palliative care. Therefore, there is a need for new therapies against this disease. According to the literature, thiosemicarbazone, phthalimide and thiazole are privileged structures with several biological activities, including antiviral activity against various viruses., Objective: Based on this, this work presents an antiviral screening using previously synthesized compounds derived from thiosemicarbazone, phthalimide, and thiazole as new hits active against ZIKV., Methods: After synthesis and characterization, all compounds were submitted to Cytotoxicity by MTT and Antiviral activity against ZIKV assays., Results: Compounds 63, 64, 65, and 73 exhibited major reductions in the ZIKV title from this evaluation. Compounds 63 (99.74%), 64 (99.77%), 65 (99.92%), and 73 (99.21%) showed a higher inhibition than the standard 6MMPr (98.74%) at the CC20 dose. These results revealed new chemical entities with anti-ZIKV activity., Conclusion: These derivatives are promising candidates for further assays. In addition, the current approach brings a new privileged scaffolding, which may drive future drug discovery for ZIKV., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
- Published
- 2023
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19. Phosphoregulation of the ATP synthase beta subunit stimulates mitochondrial activity for G2/M progression.
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Leite AC, Martins TS, Campos A, Costa V, and Pereira C
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- Adenosine Triphosphate metabolism, Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Humans, Phosphorylation, Protein Serine-Threonine Kinases genetics, Protein Serine-Threonine Kinases metabolism, Proton-Translocating ATPases genetics, Proton-Translocating ATPases metabolism, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Saccharomyces cerevisiae Proteins genetics, Saccharomyces cerevisiae Proteins metabolism, Mitochondria genetics, Mitochondria metabolism, Mitochondrial Proton-Translocating ATPases genetics, Mitochondrial Proton-Translocating ATPases metabolism
- Abstract
Mitochondrial ATP synthase is a multifunctional enzyme complex involved in ATP production. We previously reported that the ATP synthase catalytic beta subunit (Atp2p in yeast) is regulated by the 2A-like protein phosphatase Sit4p, which targets Atp2p at T124/T317 impacting on ATP synthase levels and mitochondrial respiration. Here we report that Atp2-T124/T317 is also potentially regulated by Cdc5p, a polo-like mitotic kinase. Since both Cdc5p and Sit4p have established roles in cell cycle regulation, we investigated whether Atp2-T124/T317 phosphorylation was cell cycle-related. We present evidence that Atp2p levels and phosphorylation vary during cell cycle progression, with an increase at G2/M phase. Atp2-T124/T317 phosphorylation stimulates mitochondrial membrane potential, respiration and ATP levels at G2/M phase, indicating that dynamic Atp2p phosphorylation contributes to mitochondrial activity at this specific cell cycle phase. Preventing Atp2p phosphorylation delays G2/M to G1 transition, suggesting that enhanced bioenergetics at G2/M may help meet the energetic demands of cell cycle progression. However, mimicking constitutive T124/T317 phosphorylation or overexpressing Atp2p leads to mitochondrial DNA instability, indicating that reversible Atp2p phosphorylation is critical for homeostasis. These results indicate that transient phosphorylation of Atp2p, a protein at the core of the ATP production machinery, impacts on mitochondrial bioenergetics and supports cell cycle progression at G2/M., Competing Interests: Declarations of competing interest None., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
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20. Assessment of screening programs as a strategy for early detection of oral cancer: a systematic review.
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Ribeiro MFA, Oliveira MCM, Leite AC, Bruzinga FFB, Mendes PA, Grossmann SMC, de Araújo VE, and Souto GR
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- Adolescent, Adult, Health Status, Humans, Mass Screening methods, Middle Aged, Physical Examination methods, Randomized Controlled Trials as Topic, Young Adult, Early Detection of Cancer, Mouth Neoplasms
- Abstract
The present study is a systematic review of the evaluation of screening programs as a strategy for early detection of oral cancer. The aim of this study was to assess whether screening through visual inspection is able to identify injuries in early stages, to increase survival, and to decrease the incidence and mortality of oral cancer. Studies using visual inspection to screen for oral cancer and potentially malignant lesions in apparently healthy individuals over 18 years without previous diagnosis of the disease were included. The MEDLINE/PubMed, Cochrane databases Library, EMBASE, and LILACS, including manual search and gray literature, were searched through January 2021 with no language or date restrictions. The risk of bias and the methodological quality were evaluated according to the appropriate tool for each study design. The analysis of the results was narrative. Seventeen studies were reviewed that included cohort, accuracy, and randomized clinical trial studies. The tracking type performed was opportunistic and organized in a variety of environments. The age of participants ranged between 18 and 60 years old and, in some programs, only people with risk habits for oral cancer were included. The screeners were healthcare professionals, physicians, and dentists. Two studies reported data on the incidence rate of severe cases and mortality and showed a reduction when patients were at risk for the disease and participated in the program more than once. A limitation of this review was the great variability observed in the estimates of the screening effectiveness among the studies, which made comparisons difficult. If a screening program is continuous and able to ensure the inclusion of high-risk individuals, it can contribute to improvement in survival rates with a change of stage and can have a significant impact on incidence and mortality due to the disease. Registration in the Open Science Framebook (OSF) with the osf.io/zg8nr link., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
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21. The prophylactic and anti-fibrotic activity of phthalimido-thiazole derivatives in schistosomiasis mansoni.
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Laranjeira Miranda Filho CA, de Oliveira Barbosa M, Rodrigues Oliveira A, Ferreira Pinto A, Araújo DL, Lucena JP, de Araújo RE, de Oliveira SA, and Lima Leite AC
- Subjects
- Animals, Praziquantel therapeutic use, Schistosoma mansoni, Thiazoles pharmacology, Thiazoles therapeutic use, Schistosomiasis, Schistosomiasis mansoni drug therapy, Schistosomiasis mansoni parasitology, Schistosomiasis mansoni prevention & control
- Abstract
Schistosomiasis mansoni is considered a serious public health problem. As praziquantel is the only drug recommended by the World Health Organization for the treatment and control of schistosomiasis, the development of new drugs is of great significance. In this work, we present the antischistosomal activity of a small set of phthalimido-thiazole derivatives against Schistosoma mansoni. The effects of those derivatives on the viability of larvae juveniles and adult parasites, production and development of eggs, mortality of schistosomules in vitro by counting worms, and stages of eggs of infected animals in acute and chronic phases were evaluated, resulting in the identification of new multistage antischistosomal compounds. Additionally, a study of liver fibrogenesis was released. The phthalimido-thiazole derivatives, compounds 2b-d, 2h-j, had shown activity on schistosomules, achieving 100% mortality even at 5 mg/mL, in the first 24 h. In the chronic phase of schistosomiasis infection, compound 2i promoted a reduction in the number of immature eggs, an increase in the number of non-viable parasite eggs, a reduction in the average number of eggs in the liver and intestine, decrease in the levels of hydroxyproline in the liver, and a reduction in the areas of hepatic fibrosis. This compound also promoted an increase of IL-10 and a reduction in the level of TNF-α in the liver. Accordingly, the phthalimide-thiazole scaffold is a new starting point for the development of multistage compounds that affect S. mansoni viability, egg formation, and production., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2022
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22. Immobilization of fibrinolytic protease from Mucor subtilissimus UCP 1262 in magnetic nanoparticles.
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Marques da Silva M, Wanderley Duarte Neto JM, Barros Regueira BV, Torres do Couto MT, Vitória da Silva Sobral R, Sales Conniff AE, Pedrosa Brandão Costa RM, Cajubá de Britto Lira Nogueira M, Pereira da Silva Santos N, Pastrana L, Lima Leite AC, Converti A, Nascimento TP, and Figueiredo Porto AL
- Subjects
- Chromatography, Ion Exchange, Enzyme Stability, Enzymes, Immobilized chemistry, Enzymes, Immobilized metabolism, Enzymes, Immobilized pharmacology, Fibrinogen chemistry, Fibrinogen metabolism, Fibrinolytic Agents isolation & purification, Fibrinolytic Agents pharmacology, Fungal Proteins chemistry, Fungal Proteins genetics, Fungal Proteins isolation & purification, Fungal Proteins metabolism, Humans, Hydrogen-Ion Concentration, Mucor chemistry, Mucor genetics, Peptide Hydrolases pharmacology, Temperature, Fibrinolytic Agents chemistry, Magnetite Nanoparticles chemistry, Mucor enzymology, Peptide Hydrolases chemistry, Peptide Hydrolases isolation & purification
- Abstract
This work reports the immobilization of a fibrinolytic protease (FP) from Mucor subtilissimus UCP 1262 on Fe
3 O4 magnetic nanoparticles (MNPs) produced by precipitation of FeCl3 ·6H2 O and FeCl2 ·4H2 O, coated with polyaniline and activated with glutaraldehyde. The FP was obtained by solid state fermentation, precipitated with 40-60% ammonium sulfate, and purified by DEAE-Sephadex A50 ion exchange chromatography. The FP immobilization procedure allowed for an enzyme retention of 52.13%. The fibrinolytic protease immobilized on magnetic nanoparticles (MNPs/FP) maintained more than 60% of activity at a temperature of 40 to 60 °C and at pH 7 to 10, when compared to the non-immobilized enzyme. MNPs and MNPs/FP did not show any cytotoxicity against HEK-293 and J774A.1 cells. MNPs/FP was not hemolytic and reduced the hemolysis induced by MNPs from 2.07% to 1.37%. Thrombus degradation by MNPs/FP demonstrated that the immobilization process guaranteed the thrombolytic activity of the enzyme. MNPs/FP showed a total degradation of the γ chain of human fibrinogen within 90 min. These results suggest that MNPs/FP may be used as an alternative strategy to treat cardiovascular diseases with a targeted release through an external magnetic field., (Copyright © 2022 Elsevier Inc. All rights reserved.)- Published
- 2022
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23. The impact of risk perceptions and belief in conspiracy theories on COVID-19 pandemic-related behaviours.
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Hughes JP, Efstratiou A, Komer SR, Baxter LA, Vasiljevic M, and Leite AC
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- Adolescent, Adult, Aged, Aged, 80 and over, COVID-19 prevention & control, COVID-19 virology, Communication, Cross-Sectional Studies, Female, Humans, Male, Middle Aged, SARS-CoV-2, Surveys and Questionnaires, Young Adult, COVID-19 psychology, Communicable Disease Control organization & administration, Health Behavior, Health Knowledge, Attitudes, Practice, Psychological Theory, Social Media statistics & numerical data, Vaccination psychology
- Abstract
Throughout the COVID-19 pandemic, conspiracy theories about the virus spread rapidly, and whilst governments across the globe put in place different restrictions and guidelines to contain the pandemic, these were not universally adhered to. This research examined the association between pandemic related risk perceptions, belief in conspiracy theories, and compliance with COVID-19 public guidelines amongst a UK sample (n = 368). Participants rated their level of concern for a series of potential risks during the pandemic (to the economy, personal health, freedom, media integrity and health risk to others). Participants also rated their level of belief in different conspiracy theories and self-reported their behaviour during the first UK lockdown. Mediational analyses showed that stronger belief in conspiracy theories was associated with perceptions of lower risk to health and higher risk to the economy and freedom, which in turn were associated with lower compliance with COVID-19 related governmental guidelines. Perception of information transparency risks did not mediate the association between belief in conspiracy theories and compliant behaviours. These results highlight the key role that risk perception may play in translating belief in conspiracy theories into low compliance with governmental COVID-19 related guidelines. Our findings suggest new patterns with respect to the relationship between conspiracy theory adherence and salience of different risk perceptions amidst the pandemic, which could have implications for the development of public health messaging and communication interventions., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
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24. Navigating the social identity of long covid.
- Author
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Van de Vyver J, Leite AC, and Alwan NA
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- Adult, Avoidance Learning, COVID-19 diagnosis, COVID-19 epidemiology, COVID-19 physiopathology, COVID-19 psychology, COVID-19 virology, Child, Female, Help-Seeking Behavior, Humans, Interdisciplinary Research methods, Prevalence, Quality of Life, SARS-CoV-2 genetics, Social Identification, Social Stigma, United Kingdom epidemiology, Vulnerable Populations psychology, Post-Acute COVID-19 Syndrome, Biomedical Research methods, COVID-19 complications, Social Isolation psychology
- Abstract
Competing Interests: Competing interests: All authors have lived experience of long covid.
- Published
- 2021
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25. Structural design, synthesis and anti-Trypanosoma cruzi profile of the second generation of 4-thiazolidinones chlorine derivatives.
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Bezerra de Oliveira Filho G, Veríssimo de Oliveira Cardoso M, Caroline da Silva Santos A, Ramos Dos Santos TA, Cristovão-Silva AC, Rubio LG, da Silva Maia Neto L, Leite PG, Machado FS, Alves LC, Brayner FA, Alves Pereira VR, and Lima Leite AC
- Subjects
- Animals, Chemistry Techniques, Synthetic, Dose-Response Relationship, Drug, Mice, Structure-Activity Relationship, Thiazolidines chemistry, Trypanocidal Agents chemistry, Chlorine chemistry, Drug Design, Thiazolidines chemical synthesis, Thiazolidines pharmacology, Trypanocidal Agents chemical synthesis, Trypanocidal Agents pharmacology, Trypanosoma cruzi drug effects
- Abstract
Chagas disease causes more deaths in the Americas than any other parasitic disease. Initially confined to the American continent, it is increasingly becoming a global health problem. In fact, it is considered to be an "exotic" disease in Europe, being virtually undiagnosed. Benznidazole, the only drug approved for treatment, effectively treats acute-stage Chagas disease, but its effectiveness for treating indeterminate and chronic stages remains uncertain. Previously, our research group demonstrated that 4-thiazolidinones presented anti-T. cruzi activity including in the in vivo assays in mice, making this fragment appealing for drug development. The present work reports the synthesis and anti-T. cruzi activities of a novel series of 4-thiazolidinones derivatives that resulted in an increased anti-T. cruzi activity in comparison to thiosemicarbazones intermediates. Compounds 2c, 2e, and 3a showed potent inhibition of the trypomastigote form of the parasite at low cytotoxicity concentrations in mouse splenocytes. Besides, all the 2c, 2e, and 3a tested concentrations showed no cytotoxic activity on macrophages cell viability. When macrophages were submitted to T. cruzi infection and treated with 2c and 3a, compounds reduced the release of trypomastigote forms. Results also showed that the increased trypanocidal activity induced by 2c and 3a is independent of nitric oxide release. Flow cytometry assay showed that compound 2e was able to induce necrosis and apoptosis in trypomastigotes. Parasites treated with the compounds 2e, 3a, and 3c presented flagellum shortening, retraction and curvature of the parasite body, and extravasation of the internal content. Together, these data revealed a novel series of 4-thiazolidinones fragment-based compounds with potential effects against T. cruzi and lead-like characteristics., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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26. Structural improvement of new thiazolyl-isatin derivatives produces potent and selective trypanocidal and leishmanicidal compounds.
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Barros Freitas LA, Caroline da Silva Santos A, de Cássia Silva G, Nayara do Nascimento Albuquerque F, Silva ED, Alberto de Simone C, Alves Pereira VR, Alves LC, Brayner FA, Lima Leite AC, and de Moraes Gomes PAT
- Subjects
- Drug Design, Inhibitory Concentration 50, Structure-Activity Relationship, Isatin chemistry, Isatin pharmacology, Leishmania drug effects, Thiazoles chemistry, Trypanocidal Agents chemistry, Trypanocidal Agents pharmacology
- Abstract
Neglected diseases are a group of transmissible diseases that occur mostly in countries in tropical climates. Among this group, Chagas disease and leishmaniasis stand out, considered threats to global health. Treatment for these diseases is limited. Therefore, there is a need for new therapies against these diseases. In this sense, our proposal consisted of developing two series of compounds, using a molecular hybridization of the heterocyclic isatin and thiazole. The isatin and thiazole ring are important scaffold for several biological disorders, including antiparasitic ones. Herein, thiazolyl-isatin has been synthesized from respective thiosemicarbazone or phenyl-thiosemicarbazone, being some of these new thiazolyl-isatin toxic for trypomastigotes without affecting macrophages viability. From this series, compounds 2e (IC
50 = 4.43 μM), 2j (IC50 = 2.05 μM), 2l (IC50 = 4.12 μM) and 2m (1.72 μM) showed the best anti-T. cruzi activity for trypomastigote form presenting a selectivity index higher than Benznidazole (BZN). Compounds 2j, 2l and 2m were able to induce a significantly labelling compatible with necrosis in trypomastigotes. Analysis by scanning electron microscopy showed that T. cruzi trypomastigote cells treated with the compound 2m from IC50 concentrations, promoted changes in the shape, flagella and surface of body causing of the parasite dead. Concerning leishmanicidal evaluation against L. amazonensis and L. infantum, compounds 2l (IC50 = 7.36 and 7.97 μM, respectively) and 2m (6.17 and 6.04 μM, respectively) showed the best activity for promastigote form, besides showed a higher selectivity than Miltefosine. Thus, compounds 2l and 2m showed dual in vitro trypanosomicidal and leishmanicidal activities. A structural activity relationship study showed that thiazolyl-isatin derivatives from phenyl-thiosemicarbazone (2a-m) were, in general, more active than thiazolyl-isatin derivatives from thiosemicarbazone (1a-g). Crystallography studies revealed a different configuration between series 1a-g and 2a-m. The configuration and spatial arrangement divergent between the two sub-series could explain the improved biological activity profile of 2a-m sub-series., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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27. PA-Int5: An isatin-thiosemicarbazone derivative that exhibits anti-nociceptive and anti-inflammatory effects in Swiss mice.
- Author
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Da Fonseca AG, Fernandes Ribeiro Dantas LLS, Rodrigues JP, Alencar Filho MPDC, De Melo Rêgo MJB, Da Rocha Pitta MG, De Moraes Gomes PAT, De Melo Silva VG, Lima Leite AC, Furtado AA, Fernandes Pedrosa MF, Gavioli EC, and Moura Lemos TMA
- Abstract
Pain and inflammation are symptoms of various diseases, and they can be modulated by different pathways, thus highlighting the importance of investigating the therapeutic effects of novel compounds. Previous studies have shown that isatin-thiosemicarbazone exhibits antitumor, antifungal antibacterial and other biological properties. Based on the wide range of biological effects of these compounds, the aim of the present study was to investigate the central nervous system (CNS) performance, and the anti-nociceptive and anti-inflammatory activity of (Z)-2-(5-nitro-2-oxoindolin-3-ilidene)-N-hydroazinecarbothioamide (PA-Int5) in treated mice. Three doses of PA-Int5 were tested orally (1.0, 2.5 and 5.0 mg/kg) in the nociceptive and inflammatory animal models. Additionally, the potential sedative effects of PA-Int5 (5 mg/kg, oral gavage) were investigated using an open field and rotarod tests, to exclude any possible unspecific effects of the nociceptive assays. Anti-nociceptive activity was assessed using the acetic acid-induced abdominal contortion and formalin tests, whereas anti-inflammatory activity was assessed using a carrageenan-induced paw edema and zymosan-induced air-pouch models. PA-Int5 (5 mg/kg) induced anti-nociceptive activity in the abdominal contortion model. In the formalin test, PA-Int5 (at 2.5 and 5 mg/kg) reduced nociception in the second phase. At the higher dose tested, PA-Int5 did not affect spontaneous locomotion or motor coordination. The data revealed that at all doses tested, the compound significantly reduced paw edema following carrageenan administration. In the zymosan-induced air-pouch model, PA-Int5 potently inhibited leukocyte migration and protein levels at the site of inflammation. When combined, the results revealed, for the first time, that PA-Int5 exhibited anti-nociceptive and anti-inflammatory activities, and highlights its potential, as well that of other derivatives, as novel candidates for pain relief., Competing Interests: The authors declare that they have no competing interests., (Copyright: © Da Fonseca et al.)
- Published
- 2021
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28. Trypanosoma cruzi Letm1 is involved in mitochondrial Ca 2+ transport, and is essential for replication, differentiation, and host cell invasion.
- Author
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Dos Santos GRR, Rezende Leite AC, Lander N, Chiurillo MA, Vercesi AE, and Docampo R
- Subjects
- Animals, Biological Transport, Calcium-Binding Proteins antagonists & inhibitors, Calcium-Binding Proteins genetics, Chlorocebus aethiops, Energy Metabolism, Membrane Potential, Mitochondrial, Protozoan Proteins antagonists & inhibitors, Protozoan Proteins genetics, Trypanosoma cruzi metabolism, Vero Cells, Calcium metabolism, Calcium-Binding Proteins metabolism, Cell Differentiation, Chagas Disease parasitology, Mitochondria metabolism, Protozoan Proteins metabolism, Trypanosoma cruzi growth & development
- Abstract
Leucine zipper-EF-hand containing transmembrane protein 1 (Letm1) is a mitochondrial inner membrane protein involved in Ca
2+ and K+ homeostasis in mammalian cells. Here, we demonstrate that the Letm1 orthologue of Trypanosoma cruzi, the etiologic agent of Chagas disease, is important for mitochondrial Ca2+ uptake and release. The results show that both mitochondrial Ca2+ influx and efflux are reduced in TcLetm1 knockdown (TcLetm1-KD) cells and increased in TcLetm1 overexpressing cells, without alterations in the mitochondrial membrane potential. Remarkably, TcLetm1 knockdown or overexpression increases or does not affect mitochondrial Ca2+ levels in epimastigotes, respectively. TcLetm1-KD epimastigotes have reduced growth, and both overexpression and knockdown of TcLetm1 cause a defect in metacyclogenesis. TcLetm1-KD also affected mitochondrial bioenergetics. Invasion of host cells by TcLetm1-KD trypomastigotes and their intracellular replication is greatly impaired. Taken together, our findings indicate that TcLetm1 is important for Ca2+ homeostasis and cell viability in T cruzi., (© 2021 Federation of American Societies for Experimental Biology.)- Published
- 2021
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29. Production of IL-1β, IL-6 and CXCL8 by endometrium of crossbred heifers stimulated with various pathogen-associated molecular patterns.
- Author
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Nunes PP, Martins TDM, Leite AC, Silva EBM, da Paixão TA, Santos RL, and Borges ÁM
- Subjects
- Animals, Endometrium metabolism, Estrous Cycle physiology, Female, Gene Expression Regulation drug effects, Interleukin-1beta genetics, Interleukin-6 genetics, Interleukin-8 genetics, Peptidoglycan toxicity, Tissue Culture Techniques, Cattle, Endometrium drug effects, Interleukin-1beta metabolism, Interleukin-6 metabolism, Interleukin-8 metabolism, Lipopolysaccharides toxicity
- Abstract
Uterine bacterial infections are common during the post-partum period of dairy herds and, apparently, incidences in crossbred cattle are less than in Holsteins. The aims of this study were (I) to evaluate production of interleukin 1-β (IL-1β), interleukin-6 (IL-6) and chemokine CXCL8 using endometrial explants from Bos indicus crossbred heifers at diestrous, stimulated by various pathogen-associated molecular patterns (PAMP), and (II) assess production of these cytokines by lipopolysaccharide-stimulated endometrial explants from heifers when samples were collected at different stages of estrous cycle. In the first experiment, endometrial explants from heifers at diestrous were stimulated by ten-fold serial dilutions of lipopolysaccharide (LPS), triacylated lipopeptide (PAM3) or peptidoglycan (PGN). In the second experiment, endometrial explants collected at different stages of the estrous cycle were treated with LPS. Concentrations of IL-1β, IL-6 and CXCL8 were quantified in supernatant. There was a marked (P < 0.05) production of IL-1β, IL-6, and CXCL8 in response to LPS treatment. There was also production of IL-1β (P < 0.05) in response to PGN treatment. Explant samples collected at different stages of the estrous cycle responded to LPS treatment with production of IL-1β and IL-6, but with no differences (P > 0.05) between stages of estrous cycle. In conclusion, endometrial samples of crossbred Zebu-based heifers collected during diestrous produced IL-1β, IL-6 and CXCL8 in response to LPS and IL-1β in response to PGN. The cytokine production in response to LPS, however, was not affected by the stage of the estrous cycle in Bos indicus crossbred heifers., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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30. Study of acute oral toxicity of the thiazole derivative N-(1-methyl-2-methyl-pyridine)-N-(p-bromophenylthiazol-2-yl)-hydrazine in a Syrian hamster.
- Author
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Vasconcelos Gomes de Oliveira V, Angela Aranda de Souza M, Ramos Mororó Cavalcanti R, Veríssimo de Oliveira Cardoso M, Lima Leite AC, de Figueiredo RCBQ, Rogério de Freitas Silva S, Câmara Alves L, and Amaro da Silva Junior V
- Subjects
- Animals, Cricetinae, Hydrazines, Mesocricetus, Pyridines, Kidney, Thiazoles toxicity
- Abstract
The thiazole derivative N-1-methyl-2-methyl-pyridine)-N-(p-bromophenylthiazol-2-yl)-hydrazine was used to evaluate the acute oral toxicity in Syrian hamsters. The concentration of the doses (300 mg/kg and 2000 mg/kg) were based on the "Class Acute Toxicity Method" displayed in the OECD-423 guide. In addition, renal and liver biochemical tests were performed, as well as histopathological analysis. Our results showed that the compound's lethal dose (LD50) was 1000 mg/kg and classified as category 4 according to the criteria adopted in the experiment's protocol. Biochemical analysis of the liver function's parameters showed that the LD50 values in all animals were higher than the reference values. However, the analyze of the kidney injury parameters showed an increase in the urea's dosage but a decrease in the albumin's dosage in all animals when compared to the reference values. Kidney biochemical analysis also showed that creatinine's level was only higher than the reference values in one animal. Massive damages in the liver were observed, such as hypertrophy and hyperplasia of the hepatocyte, coagulation necrosis, the presence of mononuclear cells in the sinusoidal capillaries, steatosis, cholestasis, and congestion of sinusoidal capillaries and central-lobular veins. The animals presented renal injuries related to congestion of glomerular and interstitial capillaries, nephrosis of contorted proximal and distal tubules and congestion in the medullary region. In conclusion, the thiazole derivative was well tolerated although it caused acute liver and kidney damages. Therefore, these results showed the need of further investigation of this compound in vivo to evaluate the potential therapeutic effects with chronic models.
- Published
- 2021
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31. Structural and functional characterization of the glutathione peroxidase-like thioredoxin peroxidase from the fungus Trichoderma reesei.
- Author
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Adriani PP, de Paiva FCR, de Oliveira GS, Leite AC, Sanches AS, Lopes AR, Dias MVB, and Chambergo FS
- Subjects
- Amino Acid Sequence, Antioxidants chemistry, Antioxidants pharmacology, Chemical Fractionation, Cloning, Molecular, Enzyme Activation, Fungal Proteins chemistry, Fungal Proteins genetics, Fungal Proteins metabolism, Gene Expression, Glutathione Peroxidase chemistry, Glutathione Peroxidase genetics, Glutathione Peroxidase metabolism, Hydrogen-Ion Concentration, Hypocreales genetics, Models, Molecular, Peroxiredoxins genetics, Peroxiredoxins isolation & purification, Protein Conformation, Structure-Activity Relationship, Temperature, Hypocreales enzymology, Peroxiredoxins chemistry, Peroxiredoxins metabolism
- Abstract
Glutathione peroxidases (GPx) are a family of enzymes with the ability to reduce organic and inorganic hydroperoxides to the corresponding alcohols using glutathione or thioredoxin as an electron donor. Here, we report the functional and structural characterization of a GPx identified in Trichoderma reesei (TrGPx). TrGPx was recombinantly expressed in a bacterial host and purified using affinity. Using a thioredoxin coupled assay, TrGPx exhibited activity of 28 U and 12.5 U in the presence of the substrates H
2 O2 and t-BOOH, respectively, and no activity was observed when glutathione was used. These results indicated that TrGPx is a thioredoxin peroxidase and hydrolyses H2 O2 better than t-BOOH. TrGPx kinetic parameters using a pyrogallol assay resulted at Kmapp = 11.7 mM, Vmaxapp = 10.9 IU/μg TrGPx, kcat = 19 s-1 and a catalytic efficiency of 1.6 mM-1 s-1 to H2 O2 as substrate. Besides that, TrGPx demonstrated an optimum pH ranging from 9.0-12.0 and a half-life of 36 min at 80 °C. TrGPx 3D-structure was obtained in a reduced state and non-catalytic conformation. The overall fold is similar to the other phospholipid-hydroperoxide glutathione peroxidases. These data contribute to understand the antioxidant mechanism in fungi and provide information for using antioxidant enzymes in biotechnological applications., Competing Interests: Declaration of competing interest The author declares that there are no conflicts of interest., (Copyright © 2020. Published by Elsevier B.V.)- Published
- 2021
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32. An Overview of the Compounds Tested In Vivo for Leishmania spp. of the Last 5 Years.
- Author
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de Barros Dias MCH, Freitas LAB, Dos Santos IR, de Almeida VS, do Amaral E Melo RT, de Melo Silva VG, de Fátima Maia de Santana B, da Conceição JM, and Lima Leite AC
- Subjects
- Drug Delivery Systems, Humans, Liposomes therapeutic use, Antiprotozoal Agents pharmacology, Antiprotozoal Agents therapeutic use, Leishmania, Leishmaniasis drug therapy
- Abstract
Background: Leishmaniasis, a still important public health problem, exhibits environmental risk factors such as massive migrations, urbanization, and deforestation. WHO research for Leishmaniasis is mainly focused on the development of new tools, such as diagnostic tests, drugs, and vaccines. During the drug development strategy, only a few compounds were promising and call for further study after the in vitro and in vivo preclinical tests., Objective: In this review, our group aimed to highlight the utmost research done during 2014 to 2019 in the fields of natural and synthetic compounds, as well as repurposed drugs and new formulations tested in vivo for Leishmania spp., Method: Based on the literature search, we used the databases MEDLINE, PUBMED, CAPES PERIODIC and ELSEVIER to delineate an interval of the last 5 years of research on each field., Results: Among the natural compounds tested, allicin and a fraction of potato tuber extract showed the most promising antileishmanial activity. Concerning synthetic compounds, quinolines, bornyl ester, thymol, benzoxaborole and nitroimidazole derivatives exhibited encouraging results. Moreover, repositioned alternatives involved combinations with known drugs and monotherapy protocols as well. In these years, new formulations were widely assessed as drug delivery systems, such as nanoparticles, micelles and liposomes in polymer conjugations., Conclusion: Drug repurposing and new formulations of already-known drugs are worthwhile approaches to promptly introduce new treatment schemes to Leishmaniasis. Nevertheless, the interest in new synthetic compounds and new formulations brings light to new treatment proposals and are notable lines of research., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
- Published
- 2021
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33. Peripheral facial nerve palsy associated with COVID-19.
- Author
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Lima MA, Silva MTT, Soares CN, Coutinho R, Oliveira HS, Afonso L, Espíndola O, Leite AC, and Araujo A
- Subjects
- Adult, Anti-Inflammatory Agents therapeutic use, Facial Nerve pathology, Facial Paralysis drug therapy, Female, Humans, Male, Methylprednisolone therapeutic use, Middle Aged, Prednisone therapeutic use, SARS-CoV-2, COVID-19 complications, Facial Paralysis virology
- Abstract
COVID-19 pandemic revealed several neurological syndromes related to this infection. We describe the clinical, laboratory, and radiological features of eight patients with COVID-19 who developed peripheral facial palsy during infection. In three patients, facial palsy was the first symptom. Nerve damage resulted in mild dysfunction in five patients and moderate in three. SARS-Cov-2 was not detected in CSF by PCR in any of the samples. Seven out of eight patients were treated with steroids and all patients have complete or partial recovery of the symptoms. Peripheral facial palsy should be added to the spectrum of neurological manifestations associated with COVID-19.
- Published
- 2020
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34. Dual Parasiticidal Activities of Phthalimides: Synthesis and Biological Profile against Trypanosoma cruzi and Plasmodium falciparum.
- Author
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Teixeira de Moraes Gomes PA, Veríssimo de Oliveira Cardoso M, Dos Santos IR, Amaro de Sousa F, da Conceição JM, Gouveia de Melo Silva V, Duarte D, Pereira R, Oliveira R, Nogueira F, Alves LC, Brayner FA, da Silva Santos AC, Rêgo Alves Pereira V, and Lima Leite AC
- Subjects
- Dose-Response Relationship, Drug, Molecular Structure, Parasitic Sensitivity Tests, Phthalimides chemical synthesis, Phthalimides chemistry, Structure-Activity Relationship, Trypanocidal Agents chemical synthesis, Trypanocidal Agents chemistry, Phthalimides pharmacology, Plasmodium falciparum drug effects, Trypanocidal Agents pharmacology, Trypanosoma cruzi drug effects
- Abstract
Chagas disease and malaria are two neglected tropical diseases (NTDs) that prevail in tropical and subtropical regions in 149 countries. Chagas is also present in Europe, the US and Australia due to immigration of asymptomatic infected individuals. In the absence of an effective vaccine, the control of both diseases relies on chemotherapy. However, the emergence of parasite drug resistance is rendering currently available drugs obsolete. Hence, it is crucial to develop new molecules. Phthalimides, thiosemicarbazones, and 1,3-thiazoles have been used as scaffolds to obtain antiplasmodial and anti-Trypanosoma cruzi agents. Herein we present the synthesis of 24 phthalimido-thiosemicarbazones (3 a-x) and 14 phthalimido-thiazoles (4 a-n) and the corresponding biological activity against T. cruzi, Plasmodium falciparum, and cytotoxicity against mammalian cell lines. Some of these compounds showed potent inhibition of T. cruzi at low cytotoxic concentrations in RAW 264.7 cells. The most active compounds, 3 t (IC
50 =3.60 μM), 3 h (IC50 =3.75 μM), and 4 j (IC50 =4.48 μM), were more active than the control drug benznidazole (IC50 =14.6 μM). Overall, the phthalimido-thiosemicarbazone derivatives were more potent than phthalimido-thiazole derivatives against T. cruzi. Flow cytometry assay data showed that compound 4 j was able to induce necrosis and apoptosis in trypomastigotes. Analysis by scanning electron microscopy showed that T. cruzi trypomastigote cells treated with compounds 3 h, 3 t, and 4 j at IC50 concentrations promoted changes in the shape, flagella, and surface of the parasite body similar to those observed in benznidazole-treated cells. The compounds with the highest antimalarial activity were the phthalimido-thiazoles 4 l (IC50 =1.2 μM), 4 m (IC50 =1.7 μM), and 4 n (IC50 =2.4 μM). Together, these data revealed that phthalimido derivatives possess a dual antiparasitic profile with potential effects against T. cruzi and lead-like characteristics., (© 2020 Wiley-VCH GmbH.)- Published
- 2020
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35. Smell dysfunction in COVID-19 patients: More than a yes-no question.
- Author
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Lima MA, Silva MTT, Oliveira RV, Soares CN, Takano CL, Azevedo AE, Moraes RL, Rezende RB, Chagas IT, Espíndola O, Leite AC, and Araujo A
- Subjects
- Adult, Anosmia epidemiology, Brazil epidemiology, Case-Control Studies, Comorbidity, Female, Humans, Male, Pandemics, Predictive Value of Tests, Prevalence, SARS-CoV-2 pathogenicity, Anosmia diagnosis, Anosmia physiopathology, COVID-19 epidemiology, COVID-19 physiopathology, Smell physiology
- Abstract
Anosmia has been recognized as a prevalent and early symptom by many COVID-19 patients. However, most researchers have recorded smell dysfunction solely as present or absent and based on subjective evaluation by patients. We described the results of 57 consecutive COVID-19 patients seen at FIOCRUZ, Rio de Janeiro, Brazil, from April to May 2020. Data about the presence of smell loss, the onset of smell loss and other COVID-19 symptoms such as ageusia and nasal congestion or rhinorrhea were recorded. All patients at the initial consultation and 34 healthy controls underwent the Q-SIT, which is a quick disposable three-item smell identification test, by a trained physician. We compared three groups: healthy controls, COVID+ patients with reported smell loss (COVID w/ SL) and COVID+ patients without smell loss (COVID+ w/o SL). The mean age of patients was 41.4 years (SD ± 10.4), and 54.4% were women. Smell loss was reported by 40.4% of COVID-19 patients. We observed a gradual effect with higher Q-SIT scores in healthy controls, followed by COVID+ w/o SL and COVID+ w/ SL (medians = 3, 2 and 0; respectively, p < 0.001). Anosmia or severe microsmia (Q-SIT≤1) was present in 11.1% (CI: 3.1%-26.1%) of controls, 32.4% (CI: 17.4%-50.5%) of COVID-19 w/o SL and 87% (CI: 66.4%-97.2%) of COVID+ w/ SL (p < 0.001). This study provides evidence that olfactory dysfunction in COVID-19 is common and more prevalent than what is perceived by patients. Q-SIT is a quick and reliable screening test for the detection of smell dysfunction during the pandemics., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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36. Loop-Mediated Isothermal Amplification (LAMP) Assay for Rapid and Accurate Confirmatory Diagnosis of HTLV-1/2 Infection.
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Gomes Y, Caterino-de-Araujo A, Campos K, Gonçalves MG, Leite AC, Lima MA, Araújo A, Silva MT, and Espíndola O
- Subjects
- Blood virology, Clinical Laboratory Techniques, HTLV-I Infections blood, HTLV-I Infections diagnosis, HTLV-II Infections blood, HTLV-II Infections diagnosis, Human T-lymphotropic virus 1 classification, Human T-lymphotropic virus 1 isolation & purification, Human T-lymphotropic virus 2 classification, Human T-lymphotropic virus 2 isolation & purification, Humans, Sensitivity and Specificity, HTLV-I Infections virology, HTLV-II Infections virology, Human T-lymphotropic virus 1 genetics, Human T-lymphotropic virus 2 genetics, Molecular Diagnostic Techniques methods, Nucleic Acid Amplification Techniques methods
- Abstract
Laboratory diagnosis of human T-lymphotropic viruses (HTLV) 1 and 2 infection is performed by serological screening and further confirmation with serological or molecular assays. Thus, we developed a loop-mediated isothermal nucleic acid amplification (LAMP) assay for the detection of HTLV-1/2 in blood samples. The sensitivity and accuracy of HTLV-1/2 LAMP were defined with DNA samples from individuals infected with HTLV-1 ( n = 125), HTLV-2 ( n = 19), and coinfected with HIV ( n = 82), and compared with real-time polymerase chain reaction (qPCR) and PCR-restriction fragment length polymorphism (RFLP). The overall accuracy of HTLV-1/2 LAMP (95% CI 74.8-85.5%) was slightly superior to qPCR (95% CI 69.5-81.1%) and similar to PCR-RFLP (95% CI 79.5-89.3%). The sensitivity of LAMP was greater for HTLV-1 (95% CI 83.2-93.4%) than for HTLV-2 (95% CI 43.2-70.8%). This was also observed in qPCR and PCR-RFLP, which was associated with the commonly lower HTLV-2 proviral load. All molecular assays tested showed better results with samples from HTLV-1/2 mono-infected individuals compared with HIV-coinfected patients, who present lower CD4 T-cell counts. In conclusion, HTLV-1/2 LAMP had similar to superior performance than PCR-based assays, and therefore may represent an attractive alternative for HTLV-1/2 diagnosis due to reduced working time and costs, and the simple infrastructure needed.
- Published
- 2020
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37. Four direct measurements of the fine-structure constant 13 billion years ago.
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Wilczynska MR, Webb JK, Bainbridge M, Barrow JD, Bosman SEI, Carswell RF, Dąbrowski MP, Dumont V, Lee CC, Leite AC, Leszczyńska K, Liske J, Marosek K, Martins CJAP, Milaković D, Molaro P, and Pasquini L
- Abstract
Observations of the redshift z = 7.085 quasar J1120+0641 are used to search for variations of the fine structure constant, α, over the redshift range 5.5 to 7.1. Observations at z = 7.1 probe the physics of the universe at only 0.8 billion years old. These are the most distant direct measurements of α to date and the first measurements using a near-IR spectrograph. A new AI analysis method is employed. Four measurements from the x-shooter spectrograph on the Very Large Telescope (VLT) constrain changes in a relative to the terrestrial value (α
0 ). The weighted mean electromagnetic force in this location in the universe deviates from the terrestrial value by Δα/α = (αz - α0 )/α0 = (-2.18 ± 7.27) × 10-5 , consistent with no temporal change. Combining these measurements with existing data, we find a spatial variation is preferred over a no-variation model at the 3.9σ level., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)- Published
- 2020
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38. Phenotypic and functional changes in gamma delta T lymphocytes from HTLV-1 carriers.
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Cavalcanti De Albuquerque R, Granato A, Silva Castro I, Carvalho Torres R, Santos Souza F, Lima MA, Celestino Bezerra Leite AC, de Melo Espíndola O, and Echevarria-Lima J
- Subjects
- Cell Proliferation, Cytotoxicity, Immunologic, Granzymes metabolism, HTLV-I Infections immunology, HTLV-I Infections virology, Humans, Interferon-gamma biosynthesis, Lymphocyte Count, Phenotype, Proviruses physiology, Carrier State immunology, Carrier State virology, Human T-lymphotropic virus 1 physiology, Receptors, Antigen, T-Cell, gamma-delta metabolism, T-Lymphocytes immunology
- Abstract
Human T-cell lymphotropic virus type-1 (HTLV-1) is the etiologic agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), which is a chronic inflammatory disease that leads to gradual loss of motor movement as a result of the death of spinal cord cells through immune mediated mechanisms. The risk to develop HAM/TSP disease positively correlates with the magnitude of HTLV-1 proviral load. Gamma-delta T lymphocytes have been recognized as important players in a variety of infectious diseases. Therefore, we have investigated interactions between HTLV-1 infection and γδ T lymphocytes during HAM/TSP. Similar frequencies of total γδ T lymphocytes and their Vγ9δ2
+ and Vγ9δ2neg subpopulations were observed in HAM/TSP patients. However, T lymphocytes obtained from HTLV-1 carriers displayed significantly higher rates of spontaneous proliferation and NKp30 expression when compared to cells from uninfected donors. In addition, an important decrease in the frequency of granzyme B+ γδ T lymphocytes (approximately 50%) was observed in HAM/TSP patients. Higher proportion of IFN-γ+ γδ T lymphocytes was found in HTLV-1-infected patients, which positively correlated with the HTLV-1 proviral load in peripheral blood mononuclear cells. Collectively, our data indicates that HTLV-1 infection leads to phenotypic and functional changes in the population of γδ T lymphocyte population, suggesting that HTLV-1 infection modulates functions associated to these cells, which might be involved in controlling the infection or in the development of HTLV-1-associated diseases., (©2019 Society for Leukocyte Biology.)- Published
- 2019
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39. Belief in conspiracy theories and intentions to engage in everyday crime.
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Jolley D, Douglas KM, Leite AC, and Schrader T
- Subjects
- Adult, Anomie, Cross-Sectional Studies, Female, Humans, Male, Middle Aged, Crime, Politics, Social Behavior, Thinking
- Abstract
Belief in conspiracy theories is associated with negative outcomes such as political disengagement, prejudice, and environmental inaction. The current studies - one cross-sectional (N = 253) and one experimental (N = 120) - tested the hypothesis that belief in conspiracy theories would increase intentions to engage in everyday crime. Study 1 demonstrated that belief in conspiracy theories predicted everyday crime behaviours when controlling for other known predictors of everyday crime (e.g., Honesty-Humility). Study 2 demonstrated that exposure to conspiracy theories (vs. control) increased intentions to engage in everyday crime in the future, through an increased feeling of anomie. The perception that others have conspired may therefore in some contexts lead to negative action rather than inaction., (© 2019 The British Psychological Society.)
- Published
- 2019
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40. Endorsing and Reinforcing Gender and Age Stereotypes: The Negative Effect on Self-Rated Leadership Potential for Women and Older Workers.
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Tresh F, Steeden B, Randsley de Moura G, Leite AC, Swift HJ, and Player A
- Abstract
Previous research has examined the impact of stereotypes on outcomes such as career progression and hiring decisions. We present a novel approach to examine the role of stereotypes in predicting self-rated leadership potential across gender and age groups. This research sheds light on the impact of leadership-incongruent and detrimental stereotypes about one's gender and age, for women and older workers, on self-ratings of leadership potential. Across three studies (total N = 640), correlational and experimental evidence shows differential effects of stereotypes about women (vs. men) and older (vs. younger) people on self-ratings of their own leadership potential. Results suggest that both gender and age stereotypes affect older workers more than their younger counterparts (Study 1). Specifically, effects on self-rated leadership potential at the intersectional level show that endorsement of stereotypes has opposite effects on older women to younger men (Study 1). Furthermore, stereotyped workplace cultures impacted women's and older worker's perceptions of job fit (Studies 2 and 3), also extending to job appeal for older workers (Study 3). Results are discussed in terms of career implications for both women and older workers, with a particular focus on older women, whose intersecting identities are leadership stereotype-incongruent.
- Published
- 2019
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41. Overlooked Leadership Potential: The Preference for Leadership Potential in Job Candidates Who Are Men vs. Women.
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Player A, Randsley de Moura G, Leite AC, Abrams D, and Tresh F
- Abstract
Two experiments tested the value people attach to the leadership potential and leadership performance of female and male candidates for leadership positions in an organizational hiring simulation. In both experiments, participants ( Total N = 297) valued leadership potential more highly than leadership performance, but only for male candidates. By contrast, female candidates were preferred when they demonstrated leadership performance over leadership potential. The findings reveal an overlooked potential effect that exclusively benefits men and hinders women who pursue leadership positions that require leadership potential. Implications for the representation of women in leadership positions and directions for future research are discussed.
- Published
- 2019
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42. Effect of acute exposure in swiss mice (Mus musculus) to a fibrinolytic protease produced by Mucor subtilissimus UCP 1262: An histomorphometric, genotoxic and cytological approach.
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da Silva MM, Rocha TA, de Moura DF, Chagas CA, de Aguiar Júnior FCA, da Silva Santos NP, Da Silva Sobral RV, do Nascimento JM, Lima Leite AC, Pastrana L, Costa RMPB, Nascimento TP, and Porto ALF
- Subjects
- Animals, Dose-Response Relationship, Drug, Endothelial Cells drug effects, Fibrinolytic Agents administration & dosage, Fibrinolytic Agents metabolism, Liver drug effects, Liver pathology, Mice, Peptide Hydrolases administration & dosage, Peptide Hydrolases metabolism, Alanine Transaminase metabolism, Aspartate Aminotransferases metabolism, Fibrinolytic Agents toxicity, Mucor enzymology, Peptide Hydrolases toxicity
- Abstract
The fibrinolytic enzyme produced by Mucor subtilissimus UCP 1262 was obtained by solid fermentation and purified by ion exchange chromatography using DEAE-Sephadex A50. The enzyme toxicity was evaluated using mammalian cell lineages: HEK-293, J774.A1, Sarcoma-180 and PBMCs which appeared to be viable at a level of 80%. The biochemical parameters of the mice treated with an acute dose of enzyme (2000 mg/mL) identified alterations of AST and ALT and the histomorphometric analysis of the liver showed a loss of endothelial cells (P < 0.001). However, these changes are considered minimal to affirm that there was a significant degree of hepatotoxicity. The comet assay and the micronucleus test did not identify damage in the DNA of the erythrocytes of the animals treated. The protease did not degrade the Aα and Bβ chains of human and bovine fibrinogens, thus indicating that it does not act as anticoagulant, but rather as a fibrinolytic agent. The assay performed to assess blood biocompatibility shows that at dose of 0.3-5 mg/mL the hemolytic grade is considered insignificant. Moreover, the enzyme did not prolong bleeding time in mice when dosed with 1 mg/kg. These results indicate that this enzyme produced is a potential competitor for developing novel antithrombotic drugs., (Copyright © 2019. Published by Elsevier Inc.)
- Published
- 2019
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43. Protein Profile of Blood Monocytes is Altered in HTLV-1 Infected Patients: Implications for HAM/TSP Disease.
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Echevarria-Lima J, de Abreu Pereira D, de Oliveira TS, de Melo Espíndola O, Lima MA, Celestino Leite AC, Sandim V, Rodrigues Nascimento C, E Kalume D, and B Zingali R
- Subjects
- Adult, Cell Adhesion, Cell Movement, Cytoskeleton metabolism, Female, Histones metabolism, Humans, Male, Monocytes cytology, Paraparesis, Tropical Spastic blood, Up-Regulation, Viral Load, HTLV-I Infections blood, HTLV-I Infections metabolism, Human T-lymphotropic virus 1 physiology, Monocytes metabolism, Paraparesis, Tropical Spastic metabolism, Paraparesis, Tropical Spastic virology, Proteomics
- Abstract
Human T-cell lymphotropic virus type-1 (HTLV-1) is the etiological agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The endothelial breakdown and migration of leukocytes, including monocytes, to the spinal cord are involved in HAM/TSP development. Monocytes from HTLV-1-infected individuals exhibit important functional differences when compared to cells from uninfected donors. Using proteomic shot gun strategy, performed by nanoACQUITY-UPLC system, we analyzed monocytes isolated from peripheral blood of asymptomatic carriers (AC), HAM/TSP and uninfected individuals. 534 proteins were identified among which 376 were quantified by Expression
E software. Our study revealed a panel of changes in protein expression linked to HTLV-1 infection. Upregulation of heat shock proteins and downregulation of canonical histone expression were observed in monocytes from HTLV-1-infected patients. Moreover, expression of cytoskeleton proteins was increased in monocytes from HTLV-1-infected patients, mainly in those from HAM/TSP, which was confirmed by flow cytometry and fluorescence microscopy. Importantly, functional assays demonstrated that monocytes from HAM/TSP patients present higher ability for adhesion and transmigration thought endothelium than those from AC and uninfected individuals. The major changes on monocyte protein profile were detected in HAM/TSP patients, suggesting that these alterations exert a relevant role in the establishment of HAM/TSP.- Published
- 2018
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44. Cloud point extraction of chlorophylls from spinach leaves using aqueous solutions of non-ionic surfactants.
- Author
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Leite AC, Ferreira AM, Morais ES, Khan I, Freire MG, and Coutinho JAP
- Abstract
Chlorophylls and their derivatives are currently used in a wide range of applications. To replace the volatile organic solvents commonly applied for their extraction from biomass, aqueous solutions of non-ionic surfactants are studied herein in the extraction of chlorophylls from spinach leaves. Aqueous solutions of several surfactants were screened, demonstrating that their hydrophilic-lipophilic balance (HLB) plays the pivotal role on the extraction performance, with the best results obtained for surfactants with a HLB ranging between 10 and 13. A response surface methodology (RSM) was then used to optimize operational conditions (surfactant concentration, solid-liquid ratio and temperature), leading to a maximum extraction yield of chlorophylls of 0.94 mg/g. After the extraction step, the chlorophylls-rich extract was concentrated by heating above the surfactant-water cloud point, leading to the separation into two-phases, and to a concentration factor of 9 and a recovery of 97% of chlorophylls in the surfactant-rich phase. The antioxidant activity of the extracts was finally appraised, showing that the antioxidant activity of the aqueous chlorophylls-rich extracts is higher than that obtained with volatile organic solvents. The obtained results show the potential of aqueous solutions of non-ionic surfactants to extract highly hydrophobic compounds from biomass and their possible direct use in cosmetic and nutraceutical applications, without requiring an additional recovery or purification step.
- Published
- 2018
- Full Text
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45. Surveillance or Self-Surveillance? Behavioral Cues Can Increase the Rate of Drivers' Pro-Environmental Behavior at a Long Wait Stop.
- Author
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Meleady R, Abrams D, Van de Vyver J, Hopthrow T, Mahmood L, Player A, Lamont R, and Leite AC
- Abstract
By leaving their engines idling for long periods, drivers contribute unnecessarily to air pollution, waste fuel, and produce noise and fumes that harm the environment. Railway level crossings are sites where many cars idle, many times a day. In this research, testing two psychological theories of influence, we examine the potential to encourage drivers to switch off their ignition while waiting at rail crossings. Two field studies presented different signs at a busy rail crossing site with a 2-min average wait. Inducing public self-focus (via a "Watching Eyes" stimulus) was not effective, even when accompanied by a written behavioral instruction. Instead, cueing a private-self focus ("think of yourself") was more effective, doubling the level of behavioral compliance. These findings confirm the need to engage the self when trying to instigate self-regulatory action, but that cues evoking self-surveillance may sometimes be more effective than cues that imply external surveillance., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2017
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46. Suspicion in the workplace: Organizational conspiracy theories and work-related outcomes.
- Author
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Douglas KM and Leite AC
- Subjects
- Adult, Female, Humans, Intention, Job Satisfaction, Male, Middle Aged, Personnel Turnover, Workplace organization & administration, Deception, Workplace psychology
- Abstract
Belief in conspiracy theories about societal events is widespread and has important consequences for political, health, and environmental behaviour. Little is known, however, about how conspiracy theorizing affects people's everyday working lives. In the present research, we predicted that belief in conspiracy theories about the workplace would be associated with increased turnover intentions. We further hypothesized that belief in these organizational conspiracy theories would predict decreased organizational commitment and job satisfaction. Finally, we hypothesized that these factors would mediate the relationship between organizational conspiracy theories and turnover intentions. In three studies (one correlational and two experiments, Ns = 209, 119, 202), we found support for these hypotheses. The current studies therefore demonstrate the potentially adverse consequences of conspiracy theorizing for the workplace. We argue that managers and employees should be careful not to dismiss conspiracy theorizing as harmless rumour or gossip., (© 2016 The British Psychological Society.)
- Published
- 2017
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47. Desing and synthesis of potent anti-Trypanosoma cruzi agents new thiazoles derivatives which induce apoptotic parasite death.
- Author
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da Silva EB, Oliveira E Silva DA, Oliveira AR, da Silva Mendes CH, Dos Santos TA, da Silva AC, de Castro MC, Ferreira RS, Moreira DR, Cardoso MV, de Simone CA, Pereira VR, and Leite AC
- Subjects
- Chagas Disease drug therapy, Cysteine Endopeptidases drug effects, Drug Design, Parasitic Sensitivity Tests, Protozoan Proteins drug effects, Structure-Activity Relationship, Thiazoles chemistry, Trypanocidal Agents pharmacology, Trypanosoma cruzi cytology, Apoptosis drug effects, Thiazoles pharmacokinetics, Trypanocidal Agents chemistry, Trypanosoma cruzi drug effects
- Abstract
Chagas disease, caused by the kinetoplastid protozoan parasite Trypanosoma cruzi, remains a relevant cause of illness and premature death and it is estimated that 6 million to 7 million people are infected worldwide. Although chemotherapy options are limited presenting serious problems, such as low efficacy and high toxicity. T. cruzi is susceptible to thiazoles, making this class of compounds appealing for drug development. Previously, thiazoles resulted in an increase in anti-T. cruzi activity in comparison to thiosemicarbazones. Here, we report the structural planning, synthesis and anti-T. cruzi evaluation of new thiazoles derivatives (3a-m and 4a-m), designed from molecular hybridization associated with non-classical bioisosterism. By varying substituents attached to the phenyl and thiazole rings, substituents were observed to retain, enhance or greatly increase their anti-T. cruzi activity, in comparison to the corresponding thiosemicarbazones. In most cases, electron-withdrawing substituents, such as bromine, 3,4-dichloro and nitro groups, greatly increased antiparasitic activity. Specifically, new thiazoles were identified that inhibit the epimastigote proliferation and were toxic for trypomastigotes without affecting macrophages viability. These compounds were also evaluated against cruzain. However, inhibition of this enzyme was not observed, suggesting that the compounds work through another mechanism. In addition, examination of T. cruzi cell death showed that these molecules induce apoptosis. In conclusion, except for compounds 3h and 3k, all thiazoles derivatives evaluated exhibited higher cytotoxic activity against the trypomastigote forms than the reference medicament benznidazole, without affecting macrophages viability. Compounds 4d and 4k were highlights, CC50 = 1.2 e 1.6 μM, respectively. Mechanistically, these compounds do not inhibit the cruzain, but induce T. cruzi cell death by an apoptotic process, being considered a good starting point for the development of new anti-Chagas drug candidates., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)
- Published
- 2017
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48. Isolated bladder dysfunction in human T lymphotropic virus type 1 infection: 10 years of follow-up.
- Author
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Silva MT, Espíndola OM, Leite AC, Lima MA, Schor D, and Araújo A
- Subjects
- Adult, Aged, Disease Progression, Female, Follow-Up Studies, Human T-lymphotropic virus 1, Humans, Male, Middle Aged, Paraparesis, Tropical Spastic virology, Proviruses, Urinary Bladder Diseases virology, Viral Load, HTLV-I Infections physiopathology, Muscle, Smooth physiopathology, Paraparesis, Tropical Spastic physiopathology, Urinary Bladder Diseases physiopathology
- Published
- 2017
- Full Text
- View/download PDF
49. Auditory Alterations in Children Infected by Human Immunodeficiency Virus Verified Through Auditory Processing Test.
- Author
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Romero AC, Alfaya LM, Gonçales AS, Frizzo AC, and Isaac ML
- Abstract
Introduction The auditory system of HIV-positive children may have deficits at various levels, such as the high incidence of problems in the middle ear that can cause hearing loss. Objective The objective of this study is to characterize the development of children infected by the Human Immunodeficiency Virus (HIV) in the Simplified Auditory Processing Test (SAPT) and the Staggered Spondaic Word Test. Methods We performed behavioral tests composed of the Simplified Auditory Processing Test and the Portuguese version of the Staggered Spondaic Word Test (SSW). The participants were 15 children infected by HIV, all using antiretroviral medication. Results The children had abnormal auditory processing verified by Simplified Auditory Processing Test and the Portuguese version of SSW. In the Simplified Auditory Processing Test, 60% of the children presented hearing impairment. In the SAPT, the memory test for verbal sounds showed more errors (53.33%); whereas in SSW, 86.67% of the children showed deficiencies indicating deficit in figure-ground, attention, and memory auditory skills. Furthermore, there are more errors in conditions of background noise in both age groups, where most errors were in the left ear in the Group of 8-year-olds, with similar results for the group aged 9 years. Conclusion The high incidence of hearing loss in children with HIV and comorbidity with several biological and environmental factors indicate the need for: 1) familiar and professional awareness of the impact on auditory alteration on the developing and learning of the children with HIV, and 2) access to educational plans and follow-up with multidisciplinary teams as early as possible to minimize the damage caused by auditory deficits.
- Published
- 2017
- Full Text
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50. Few Ant Species Play a Central Role Linking Different Plant Resources in a Network in Rupestrian Grasslands.
- Author
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Costa FV, Mello MA, Bronstein JL, Guerra TJ, Muylaert RL, Leite AC, and Neves FS
- Subjects
- Animals, Brazil, Ants physiology, Biodiversity, Grassland, Plants
- Abstract
Ant-plant associations are an outstanding model to study the entangled ecological interactions that structure communities. However, most studies of plant-animal networks focus on only one type of resource that mediates these interactions (e.g, nectar or fruits), leading to a biased understanding of community structure. New approaches, however, have made possible to study several interaction types simultaneously through multilayer networks models. Here, we use this approach to ask whether the structural patterns described to date for ant-plant networks hold when multiple interactions with plant-derived food rewards are considered. We tested whether networks characterized by different resource types differ in specialization and resource partitioning among ants, and whether the identity of the core ant species is similar among resource types. We monitored ant interactions with extrafloral nectaries, flowers, and fruits, as well as trophobiont hemipterans feeding on plants, for one year, in seven rupestrian grassland (campo rupestre) sites in southeastern Brazil. We found a highly tangled ant-plant network in which plants offering different resource types are connected by a few central ant species. The multilayer network had low modularity and specialization, but ant specialization and niche overlap differed according to the type of resource used. Beyond detecting structural differences across networks, our study demonstrates empirically that the core of most central ant species is similar across them. We suggest that foraging strategies of ant species, such as massive recruitment, may determine specialization and resource partitioning in ant-plant interactions. As this core of ant species is involved in multiple ecosystem functions, it may drive the diversity and evolution of the entire campo rupestre community., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2016
- Full Text
- View/download PDF
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