12 results on '"Leite, R. B."'
Search Results
2. Dental trauma among Brazilian schoolchildren: prevalence, treatment and associated factors
- Author
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Martins, V. M., Sousa, R. V., Rocha, E. S., Leite, R. B., Paiva, S. M., and Granville-Garcia, A. F.
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- 2012
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3. Effect of the Herbicide Roundup® on Perkinsus olseni in vitro Proliferation and in vivo Survival when Infecting a Permissive Host, the Clam Ruditapes decussatus
- Author
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Elandalloussi, L. M., Leite, R. B., Rodrigues, P. M., Afonso, R., and Cancela, M. L.
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- 2008
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4. Changes at transcriptome level during host-parasite interaction using Perkinsus olseni as a model: B1.33
- Author
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Leite, R. B. and Cancela, M. L.
- Published
- 2010
5. A Portuguese survey
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Padrao, E., Araujo, D., Todo Bom, A., Robalo Cordeiro, C., Correia de Sousa, J., Cardoso, J., Morais-Almeida, M., Costa, R., Pavao, F., Leite, R. B., Marques, A., and NOVA Medical School|Faculdade de Ciências Médicas (NMS|FCM)
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Overlap ,Diagnosis ,COPD ,Delphi survey ,Definition ,Asthma ,Management - Abstract
publishersversion published
- Published
- 2018
6. Recommendations for evaluation of the health status in cultured and wild shellfish: Perkinsus olseni infestation in clams as an example
- Author
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Miossec, Laurence, Isabelle Arzul, Garcia, Celine, Soudant, Philippe, Francois, Cyrille, Leite, R. B., Cancela, M. L., and Blas, I.
- Subjects
Aquatic animal diseases ,Epidemiology ,Pathology ,Recommendations ,Perkinsus olseni - Abstract
Infectious diseases in exploited shellfish population cause economical problems world-wide. The characteristics of the disease in the population -i.e. origin, frequency, distribution, development- need to be well known to set up appropriate measures for protection and restoration of shellfish population health. The investigation of disease in a population is the basis of epidemiology. Quantitative investigations include studies, survey, surveillance with specific sampling strategies according to the objectives. European clams (Ruditapes decussatus) and Manila clams (Ruditapes philippinarum), two commercially valuable species, are infected by the protozoan Perkinsus olseni. This pathogen has been associated with epizootic outbreaks involving in heavy mortality of shellfish, including clams. In Europe, the parasite was detected in Italy (the Veneto region), Portugal (Ria Formosa, Ria do Alvor, V.N. Milfontes, Aveiro, Lagoa de Obidos), Spain (Galicia) and France (Chausey Island, Golfe of Morbihan, Marennes-Oleron, Arcachon bay, Leucate and Thau lagoon). We analysed published and unpublished data on Perkinsus olseni infestation in wild and cultured clams collected in Europe, from the English Channel to the Mediterranean coast. Results obtained from these studies clearly demonstrate the detection of Perkinsus olseni in all sampling sites albeit with different intensities. We discuss these disease frequencies according to 1) objective, 2) targeted population, 3) methodological design, 4) quality of diagnostic tests and 5) characterisation of the pathogen. We emphasise the need for a relevant sampling strategy to measure occurrence of the disease.
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- 2005
7. Expression pattern of Perkinsus olseni genes in response to bivalves with different susceptibility to perkinsosis.
- Author
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Ascenso, R. M. T., Leite, R. B., Afonso, R., and Cancela, M. L.
- Subjects
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GENE expression , *BIVALVES , *PROTOZOA , *PARASITES , *MANILA clam , *HOST-parasite relationships , *HOSTS (Biology) , *GENES , *VENERUPIS - Abstract
The article presents a study that investigates the pattern of expression of selected genes of Perkinsus olseni following exposure to bivalves with different susceptibility to perkinsosis. The haemolymph of a permissive host, Ruditapes decussatus, a permissive, but not susceptible host, Ruditapes philippinarum and the non-permissive bivalve, Donax trunculus have been used in the study. The procedure of the study has been described. It was indicated that the parasite can modulate its response according to the degree of the susceptibility of the bivalves. It is stated that the approach followed in this study allowed the initial characterization of a new set of gene sequences of P. olseni involved in host interaction.
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- 2009
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8. Effect of the Herbicide Roundup® on Perkinsus olseni in vitro Proliferation and in vivo Survival when Infecting a Permissive Host, the Clam Ruditapes decussatus.
- Author
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Elandalloussi, L. M., Leite, R. B., Rodrigues, P. M., Afonso, R., and Cancela, M. L.
- Subjects
GLYPHOSATE ,CLAMS ,HERBICIDES ,GLYPHOSATE in water ,ENVIRONMENTAL toxicology ,TOXICOLOGY - Abstract
Coastal habitats are increasingly being exposed to herbicide contamination from urban and agricultural catchments. Data on its toxicity on aquatic ecosystems, especially those based on sediment, are relatively scarce. This study aimed at investigating whether the susceptibility of an aquatic filter-feeding organism, the carpet-shell clam ( Ruditapes decussatus) to the parasite Perkinsus olseni was influenced by the herbicide Roundup
® and its active ingredient glyphosate. The effect of Roundup® and glyphosate on P. olseni in vitro proliferation was also evaluated and appeared to confirm the higher toxicity of Roundup when compared with technical grade glyphosate. [ABSTRACT FROM AUTHOR]- Published
- 2008
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9. Asthma-COPD overlap: A Portuguese survey.
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Padrão E, Araújo D, Todo Bom A, Robalo Cordeiro C, Correia de Sousa J, Cardoso J, Morais-Almeida M, Costa R, Pavão F, Leite RB, and Marques A
- Abstract
Introduction: The overlap between asthma and chronic obstructive pulmonary disease (COPD) (ACO) has been discussed for many years but clinical recommendations for this entity have been diverse. This study is intended to reach a consensus on diagnosis, treatment and patient orientation for ACO, within the Portuguese medical community., Methods: This study was conducted by a multidisciplinary panel of experts from three distinct medical specialties (Pulmonology, Family Medicine and Immunoallergology). This panel selected a total of 190 clinicians, based on their expertise in obstructive airway diseases, to participate in a Delphi structured survey with three rounds of questionnaires. These results were ultimately discussed, in a meeting with the panel of experts and some of the study participants, and consensus was reached in terms of classification criteria, treatment and orientation of ACO patients., Results: The majority of clinicians (87.2%) considered relevant the definition of an overlap entity between asthma and COPD. A consensus was achieved on the diagnosis of ACO - presence of simultaneous clinical characteristics of asthma and COPD together with a fixed airflow obstruction (FEV1/FVC<0.7) associated with 2 major criteria (previous history of asthma; presence of a previous history of smoking exposure and/or exposure to biomass combustion; positive bronchodilation test (increase in FEV
1 of at least 200mL and 12%) on more than 1 occasion) plus 1 minor criteria (history of atopy; age ≥40 years; peripheral eosinophilia (>300eosinophils/μL or >5% of leukocytes); elevation of specific IgEs or positive skin tests for common allergens). A combination of inhaled corticosteroid (ICS) with long-acting beta2-agonist (LABA) or long-acting muscarinic antagonist (LAMA) was considered as first line pharmacological treatment. Triple therapy with ICS plus LABA and LAMA should be used in more severe or symptomatic cases. Non-pharmacological treatment, similar to what is recommended for asthma and COPD, was also considered highly important. A hospital referral of ACO patients should be made in symptomatic or severe cases or when there is a lack of diagnostic resources., Conclusions: This study highlights the relevance of defining ACO, within the Portuguese medical community, and establishes diagnostic criteria that are important for future interventional studies. Recommendations on treatment and patient's orientation were also achieved., (Copyright © 2018 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)- Published
- 2018
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10. Asthma-chronic obstructive pulmonary disease overlap syndrome - Literature review and contributions towards a Portuguese consensus.
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Araújo D, Padrão E, Morais-Almeida M, Cardoso J, Pavão F, Leite RB, Caldas AC, and Marques A
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- Asthma complications, Consensus, Humans, Portugal, Practice Guidelines as Topic, Pulmonary Disease, Chronic Obstructive complications, Syndrome, Asthma diagnosis, Pulmonary Disease, Chronic Obstructive diagnosis
- Abstract
Introduction: Phenotypic overlap between the two main chronic airway pulmonary diseases, asthma and chronic obstructive pulmonary disease (COPD), has been the subject of debate for decades, and recently the nomenclature of asthma-COPD overlap syndrome (ACOS) was adopted for this condition. The definition of this entity in the literature is, however, very heterogeneous, it is therefore important to define how it applies to Portugal., Methods: A literature review of ACOS was made in a first phase resulting in the drawing up of a document that was later submitted for discussion among a panel of chronic lung diseases experts, resulting in reflexions about diagnosis, treatment and clinical guidance for ACOS patients., Results: There was a consensus among the experts that the diagnosis of ACOS should be considered in the concomitant presence of: clinical manifestations characteristic of both asthma and COPD, persistent airway obstruction (post-bronchodilator FEV
1 /FVC<0.7), positive response to bronchodilator test (increase in FEV1 of ≥200mL and ≥12% from baseline) and current or past history of smoking or biomass exposure. In reaching diagnosis, the presence of peripheral eosinophilia (>300eosinophils/μL or >5% of leukocytes) and previous history of atopy should also be considered. The recommended first line pharmacological treatment in these patients is the ICS/LABA association; if symptomatic control is not achieved or in case of clinical severity, triple therapy with ICS/LABA/LAMA may be used. An effective control of the exposure to risk factors, vaccination, respiratory rehabilitation and treatment of comorbidities is also important., Conclusions: The creation of initial guidelines on ACOS, which can be applied in the Portuguese context, has an important role in the generation of a broad nationwide consensus. This will give, in the near future, a far better clinical, functional and epidemiological characterization of ACOS patients, with the ultimate goal of achieving better therapeutic guidance., (Copyright © 2016 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)- Published
- 2017
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11. Evolutionary conservation of TFIIH subunits: implications for the use of zebrafish as a model to study TFIIH function and regulation.
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Silva IA, Cox CJ, Leite RB, Cancela ML, and Conceição N
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- Alternative Splicing, Amino Acid Sequence, Animals, Binding Sites, Chromosome Mapping, Conserved Sequence, Fishes genetics, Humans, Molecular Sequence Data, Octamer Transcription Factor-1 genetics, Octamer Transcription Factor-1 metabolism, Promoter Regions, Genetic, Protein Conformation, Transcription Factor AP-1 genetics, Transcription Factor AP-1 metabolism, Transcription Factor TFIIH chemistry, Xeroderma Pigmentosum Group D Protein chemistry, Xeroderma Pigmentosum Group D Protein genetics, Zebrafish genetics, Zebrafish Proteins genetics, Evolution, Molecular, Transcription Factor TFIIH physiology
- Abstract
Transcriptional factor IIH (TFIIH) is involved in cell cycle regulation, nucleotide excision repair, and gene transcription. Mutations in three of its subunits, XPB, XPD, and TTDA, lead to human recessive genetic disorders such as trichothiodystrophy and xeroderma pigmentosum, the latter of which is sometimes associated with Cockayne's syndrome. In the present study, we investigate the sequence conservation of TFIIH subunits among several teleost fish species and compare their characteristics and putative regulation by transcription factors to those of human and zebrafish. We report the following findings: (i) comparisons among protein sequences revealed a high sequence identity for each TFIIH subunit analysed; (ii) among transcription factors identified as putative regulators, OCT1 and AP1 have the highest binding-site frequencies in the promoters of TFIIH genes, and (iii) TFIIH genes have alternatively spliced isoforms. Finally, we compared the protein primary structure in human and zebrafish of XPD and XPB - two important ATP-dependent helicases that catalyse the unwinding of the DNA duplex at promoters during transcription - highlighting the conservation of domain regions such as the helicase domains. Our study suggests that zebrafish, a widely used model for many human diseases, could also act as an important model to study the function of TFIIH complex in repair and transcription regulation in humans., (Copyright © 2014 Elsevier Inc. All rights reserved.)
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- 2014
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12. Peroxides with antiplasmodial activity inhibit proliferation of Perkinsus olseni, the causative agent of Perkinsosis in bivalves.
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Araujo NC, Afonso R, Bringela A, Cancela ML, Cristiano ML, and Leite RB
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- Adenosine Triphosphatases drug effects, Adenosine Triphosphatases genetics, Alveolata cytology, Alveolata genetics, Animals, Antiparasitic Agents chemistry, Artemisinins chemistry, Cation Transport Proteins drug effects, Cation Transport Proteins genetics, Cell Proliferation drug effects, Ferrous Compounds pharmacology, Heterocyclic Compounds chemistry, Heterocyclic Compounds pharmacology, Humans, Peroxides chemistry, Protozoan Proteins genetics, Alveolata drug effects, Antiparasitic Agents pharmacology, Artemisinins pharmacology, Bivalvia parasitology, Peroxides pharmacology
- Abstract
Perkinsus olseni, the causative agent of Perkinsosis, can drastically affect the survival of target marine mollusks, with dramatic economic consequences for aquaculture. P. olseni is a member of the Alveolata group, which also comprises parasites that are highly relevant for medical and veterinary sciences such as Plasmodium falciparum and Toxoplasma. P. olseni shares several unique metabolic pathways with those pathological parasites but is not toxic to humans. In this work, six antimalarially active peroxides, derived from the natural product artemisinin or synthetic trioxolanes, were synthesized and tested on P. olseni proliferation and survival. All peroxides tested revealed an inhibitory effect on P. olseni proliferation at micromolar concentrations. The relevance of the peroxide functionality on toxicity and the effect of Fe(II)-intracellular concentration on activity were also evaluated. Results demonstrated that the peroxide functionality is the toxofore and intracellular iron concentration also proved to be a crucial co-factor on the activation of peroxides in P. olseni. These data points to a mechanism of bioactivation in P. olseni sharing similarities with the one proposed in P. falciparum parasites. Preliminary studies on bioaccumulation were conducted using fluorescent-labeled peroxides. Results show that synthetic trioxolanes tend to accumulate on a vacuole while the labeled artemisinin accumulates in the cytoplasm. Preliminary experiments on differential genes expression associated to Fe(II) transport protein (Nramp) and calcium transport protein (ATP6/SERCA) were also conducted by qPCR. Results point to a fourfold increase in expression of both genes upon exposure to trioxolanes and approximately twofold upon exposure to artemisinin derivatives. Data obtained in this investigation is relevant for better understanding of the biology of Perkinsus and may also be important in the development of new strategies for Perkinsosis prevention and control., (© 2013.)
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- 2013
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