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Clemente E, Domingues E, Quinta-Ferreira RM, Leitão A, Martins RC. Solar photo-Fenton and persulphate-based processes for landfill leachate treatment: A critical review. Sci Total Environ 2024; 912:169471. [PMID: 38145668 DOI: 10.1016/j.scitotenv.2023.169471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/15/2023] [Accepted: 12/16/2023] [Indexed: 12/27/2023]
Abstract
Landfilling is the most usual solid waste management strategy for solid residues disposal. However, it entails several drawbacks such as the generation of landfill leachate that seriously threaten human life and the environment due to their toxicity and carcinogenic character. Among various technologies, solar photo-Fenton and sulphate-based processes have proven to be suitable for the treatment of these polluted streams. This review critically summarises the last three decades of studies in this field. It is found that the solar homogeneous photo-Fenton process should be preferably used as a pre- and post-treatment of biological technologies and as a standalone treatment for young, medium, and mature leachates, respectively. Studies on heterogeneous solar photo-Fenton process are lacking so that this technology may be scaled-up for industrial applications. Sulphate radicals are attractive for removing both COD and ammonia. However, no study has been reported on solar sulphate activation for landfill leachate treatment. This review discusses the main advances and challenges on treating landfill leachate through solar AOPs, it compares solar photo-Fenton and solar persulphate-based treatments, indicates the future research directions and contributes for a better understanding of these technologies towards sustainable treatment of landfill leachate in sunny and not-so-sunny regions.
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Affiliation(s)
- E Clemente
- University of Coimbra, CIEPQPF - Chemical Engineering Processes and Forest Products Research Center, Department of Chemical Engineering, Faculty of Sciences and Technology, Rua Sílvio Lima, Polo II, 3030-790 Coimbra, Portugal; LESRA - Laboratory of Separation, Reaction and Environmental Engineering, Faculty of Engineering, Agostinho Neto University, Av. Ho Chi Min no 201, Luanda, Angola
| | - E Domingues
- University of Coimbra, CIEPQPF - Chemical Engineering Processes and Forest Products Research Center, Department of Chemical Engineering, Faculty of Sciences and Technology, Rua Sílvio Lima, Polo II, 3030-790 Coimbra, Portugal
| | - R M Quinta-Ferreira
- University of Coimbra, CIEPQPF - Chemical Engineering Processes and Forest Products Research Center, Department of Chemical Engineering, Faculty of Sciences and Technology, Rua Sílvio Lima, Polo II, 3030-790 Coimbra, Portugal
| | - A Leitão
- LESRA - Laboratory of Separation, Reaction and Environmental Engineering, Faculty of Engineering, Agostinho Neto University, Av. Ho Chi Min no 201, Luanda, Angola
| | - R C Martins
- University of Coimbra, CIEPQPF - Chemical Engineering Processes and Forest Products Research Center, Department of Chemical Engineering, Faculty of Sciences and Technology, Rua Sílvio Lima, Polo II, 3030-790 Coimbra, Portugal.
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Damásio M, Barbosa M, Deus J, Fernandes E, Leitão A, Albino L, Fonseca F, Silvestre J. Can Grapevine Leaf Water Potential Be Modelled from Physiological and Meteorological Variables? A Machine Learning Approach. Plants (Basel) 2023; 12:4142. [PMID: 38140469 PMCID: PMC10747955 DOI: 10.3390/plants12244142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/22/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023]
Abstract
Climate change is affecting global viticulture, increasing heatwaves and drought. Precision irrigation, supported by robust water status indicators (WSIs), is inevitable in most of the Mediterranean basin. One of the most reliable WSIs is the leaf water potential (Ψleaf), which is determined via an intrusive and time-consuming method. The aim of this work is to discern the most effective variables that are correlated with plants' water status and identify the variables that better predict Ψleaf. Five grapevine varieties grown in the Alentejo region (Portugal) were selected and subjected to three irrigation treatments, starting in 2018: full irrigation (FI), deficit irrigation (DI), and no irrigation (NI). Plant monitoring was performed in 2023. Measurements included stomatal conductance (gs), predawn water potential Ψpd, stem water potential (Ψstem), thermal imaging, and meteorological data. The WSIs, namely Ψpd and gs, responded differently according to the irrigation treatment. Ψstem measured at mid-morning (MM) and mid-day (MD) proved unable to discern between treatments. MM measurements presented the best correlations between WSIs. gs showed the best correlations between the other WSIs, and consequently the best predictive capability to estimate Ψpd. Machine learning regression models were trained on meteorological, thermal, and gs data to predict Ψpd, with ensemble models showing a great performance (ExtraTrees: R2=0.833, MAE=0.072; Gradient Boosting: R2=0.830; MAE=0.073).
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Affiliation(s)
- Miguel Damásio
- INIAV I.P., Instituto Nacional de Investigação Agrária e Veterinária, Polo de Inovação de Dois Portos, Quinta da Almoinha, 2565-191 Dois Portos, Portugal; (J.D.); (J.S.)
| | - Miguel Barbosa
- SISCOG SA, Sistemas Cognitivos, Campo Grande, 378 - 3°, 1700-097 Lisboa, Portugal; (M.B.); (E.F.); (A.L.); (L.A.); (F.F.)
| | - João Deus
- INIAV I.P., Instituto Nacional de Investigação Agrária e Veterinária, Polo de Inovação de Dois Portos, Quinta da Almoinha, 2565-191 Dois Portos, Portugal; (J.D.); (J.S.)
| | - Eduardo Fernandes
- SISCOG SA, Sistemas Cognitivos, Campo Grande, 378 - 3°, 1700-097 Lisboa, Portugal; (M.B.); (E.F.); (A.L.); (L.A.); (F.F.)
| | - André Leitão
- SISCOG SA, Sistemas Cognitivos, Campo Grande, 378 - 3°, 1700-097 Lisboa, Portugal; (M.B.); (E.F.); (A.L.); (L.A.); (F.F.)
| | - Luís Albino
- SISCOG SA, Sistemas Cognitivos, Campo Grande, 378 - 3°, 1700-097 Lisboa, Portugal; (M.B.); (E.F.); (A.L.); (L.A.); (F.F.)
| | - Filipe Fonseca
- SISCOG SA, Sistemas Cognitivos, Campo Grande, 378 - 3°, 1700-097 Lisboa, Portugal; (M.B.); (E.F.); (A.L.); (L.A.); (F.F.)
| | - José Silvestre
- INIAV I.P., Instituto Nacional de Investigação Agrária e Veterinária, Polo de Inovação de Dois Portos, Quinta da Almoinha, 2565-191 Dois Portos, Portugal; (J.D.); (J.S.)
- GREEN-IT Bioresources4sustainability, ITQB NOVA, Av. da República, 2780-157 Oeiras, Portugal
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Piló D, Carvalho S, Pereira P, Gaspar MB, Leitão A. Is metal contamination responsible for increasing aneuploidy levels in the Manila clam Ruditapes philippinarum? Sci Total Environ 2017; 577:340-348. [PMID: 27817921 DOI: 10.1016/j.scitotenv.2016.10.193] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 06/06/2023]
Abstract
The present study assessed the metal genotoxicity potential at chromosome-level in the bivalve Ruditapes philippinarum collected along different areas of the Tagus estuary. Higher levels of aneuploidy on gill cells were detected at the most sediment contaminated area both in May (31.7%) and October (36.0%) when compared to a less contaminated area over the same periods (20.3% and 29.0% respectively). Interestingly, metal bioaccumulation in gills was higher in the specimens collected at the least contaminated area with the exception of Pb. Indeed, the multivariate analysis revealed a stronger relation between aneuploidy and sediment contamination than between aneuploidy and the bioaccumulation of the metals. The temporal and spatial inconsistency found for the bioaccumulation of metals in R. philippinarum and the positive correlation between sediment contamination and aneuploidy at the most contaminated area suggest that these chromosome-level effects might be due to chronic metal contamination occurring in the Tagus estuary, rather than a direct result of the temporal variation of bioavailable contaminants. The vertical transmission phenomenon of bivalve aneuploidy levels may then be perpetuating those levels on clams from the most contaminated area. The present results shed light about the effect of metal toxicity at the chromosome-level in species inhabiting chronic contaminated areas and highlight the use of aneuploidy as an effective tool to identify persistent contamination in worldwide transitional waters.
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Affiliation(s)
- D Piló
- Portuguese Institute for the Ocean and Atmosphere (IPMA), Avenida 5 de Outubro, 8700-305 Olhão, Portugal; Department of Biology, Faculty of Marine and Environment Sciences, University of Cadiz, Campus de Excelencia International del Mar (CEIMAR), Avda. República Saharaui S/N Puerto Real, 11510 Puerto Real, Cadiz, Spain.
| | - S Carvalho
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal 23955-6900, Saudi Arabia
| | - P Pereira
- Portuguese Institute for the Ocean and Atmosphere (IPMA), Av. Brasília, 1449-006 Lisbon, Portugal; Centre for Environmental and Marine Studies and Department of Biology (CESAM), University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - M B Gaspar
- Portuguese Institute for the Ocean and Atmosphere (IPMA), Avenida 5 de Outubro, 8700-305 Olhão, Portugal; Centre of Marine Sciences (CCMAR), University of Algarve (UAlg), Campus de Gambelas, 8005-139 Faro, Portugal
| | - A Leitão
- Environmental Science Center (ESC), Qatar University, P.O. Box 2713, Doha, Qatar
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Bule P, Alves VD, Leitão A, Ferreira LMA, Bayer EA, Smith SP, Gilbert HJ, Najmudin S, Fontes CMGA. Single Binding Mode Integration of Hemicellulose-degrading Enzymes via Adaptor Scaffoldins in Ruminococcus flavefaciens Cellulosome. J Biol Chem 2016; 291:26658-26669. [PMID: 27875311 PMCID: PMC5207176 DOI: 10.1074/jbc.m116.761643] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/08/2016] [Indexed: 11/06/2022] Open
Abstract
The assembly of one of Nature's most elaborate multienzyme complexes, the cellulosome, results from the binding of enzyme-borne dockerins to reiterated cohesin domains located in a non-catalytic primary scaffoldin. Generally, dockerins present two similar cohesin-binding interfaces that support a dual binding mode. The dynamic integration of enzymes in cellulosomes, afforded by the dual binding mode, is believed to incorporate additional flexibility in highly populated multienzyme complexes. Ruminococcus flavefaciens, the primary degrader of plant structural carbohydrates in the rumen of mammals, uses a portfolio of more than 220 different dockerins to assemble the most intricate cellulosome known to date. A sequence-based analysis organized R. flavefaciens dockerins into six groups. Strikingly, a subset of R. flavefaciens cellulosomal enzymes, comprising dockerins of groups 3 and 6, were shown to be indirectly incorporated into primary scaffoldins via an adaptor scaffoldin termed ScaC. Here, we report the crystal structure of a group 3 R. flavefaciens dockerin, Doc3, in complex with ScaC cohesin. Doc3 is unusual as it presents a large cohesin-interacting surface that lacks the structural symmetry required to support a dual binding mode. In addition, dockerins of groups 3 and 6, which bind exclusively to ScaC cohesin, display a conserved mechanism of protein recognition that is similar to Doc3. Groups 3 and 6 dockerins are predominantly appended to hemicellulose-degrading enzymes. Thus, single binding mode dockerins interacting with adaptor scaffoldins exemplify an evolutionary pathway developed by R. flavefaciens to recruit hemicellulases to the sophisticated cellulosomes acting in the gastrointestinal tract of mammals.
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Affiliation(s)
- Pedro Bule
- From the CIISA-Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Victor D Alves
- From the CIISA-Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - André Leitão
- From the CIISA-Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Luís M A Ferreira
- From the CIISA-Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Edward A Bayer
- the Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Steven P Smith
- the Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada, and
| | - Harry J Gilbert
- the Institute for Cell and Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Shabir Najmudin
- From the CIISA-Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Carlos M G A Fontes
- From the CIISA-Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal,
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Rebordão MR, Carneiro C, Alexandre-Pires G, Brito P, Pereira C, Nunes T, Galvão A, Leitão A, Vilela C, Ferreira-Dias G. Neutrophil extracellular traps formation by bacteria causing endometritis in the mare. J Reprod Immunol 2014; 106:41-9. [PMID: 25218891 DOI: 10.1016/j.jri.2014.08.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 07/08/2014] [Accepted: 08/04/2014] [Indexed: 12/12/2022]
Abstract
Besides the classical functions, neutrophils (PMNs) are able to release DNA in response to infectious stimuli, forming neutrophil extracellular traps (NETs) and killing pathogens. The pathogenesis of endometritis in the mare is not completely understood. The aim was to evaluate the in vitro capacity of equine PMNs to secrete NETs by chemical activation, or stimulated with Streptococcus equi subspecies zooepidemicus (Szoo), Escherichia coli (Ecoli) or Staphylococcus capitis (Scap) strains obtained from mares with endometritis. Ex vivo endometrial mucus from mares with bacterial endometritis were evaluated for the presence of NETs. Equine blood PMNs were used either without or with stimulation by phorbol-myristate-acetate (PMA), a strong inducer of NETs, for 1-3h. To evaluate PMN ability to produce NETs when phagocytosis was impaired, the phagocytosis inhibitor cytochalasin (Cyt) was added after PMA. After the addition of bacteria, a subsequent 1-h incubation was carried out in seven groups. NETs were visualized by 4',6-diamidino-2-phenylindole (DAPI) and anti-histone. Ex vivo samples were immunostained for myeloperoxidase and neutrophil elastase. A 3-h incubation period of PMN + PMA increased NETs (p < 0.05). Bacteria + 25 nM PMA and bacteria + PMA + Cyt increased NETs (p<0.05). Szoo induced fewer NETs than Ecoli or Scap (p < 0.05). Ex vivo NETs were present in mares with endometritis. Scanning electron microscopy showed the spread of NETs formed by smooth fibers and globules that can be aggregated in thick bundles. Formation of NETs and the subsequent entanglement of bacteria suggest that equine NETs might be a complementary mechanism in fighting some of the bacteria causing endometritis in the mare.
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Affiliation(s)
- M R Rebordão
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal; Coimbra College of Agriculture, Coimbra, Portugal
| | - C Carneiro
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - G Alexandre-Pires
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - P Brito
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - C Pereira
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - T Nunes
- Faculty of Sciences, Microscopy Center, University of Lisbon, Portugal
| | - A Galvão
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - A Leitão
- Instituto de Investigação Científica Tropical, CVZ, CIISA, Lisbon, Portugal
| | - C Vilela
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - G Ferreira-Dias
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal.
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Araújo I, Fonseca C, Cardiga R, Dores H, Ferreira R, Gândara F, Proença M, Marques F, Leitão A, Ceia F. CHA2DS2-VASc and HASBLED scores: Implications for thromboembolic prophylaxis in the elderly with atrial fibrillation. Eur Geriatr Med 2013. [DOI: 10.1016/j.eurger.2012.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Soares F, Leitão A, Moreira M, de Sousa JT, Almeida AC, Barata M, Feist SW, Pousão-Ferreira P, Ribeiro L. Sarcoma in the thymus of juvenile meagre Argyrosomus regius reared in an intensive system. Dis Aquat Organ 2012; 102:119-127. [PMID: 23269386 DOI: 10.3354/dao02545] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Juvenile meagre Argyrosomus regius (Asso, 1809) maintained in experimental conditions developed lateral and/or bilateral circular-shaped sarcoma within the opercular cavity. The sarcoma was dense, reddish and its growth from the branchial arch exerted pressure on the operculum forcing it to open. Histologically, the neoplasm exhibited marked proliferation of mesenchymal connective tissue composed largely of fusiform cells, which developed in a solid pattern accompanied by abundant mononuclear cell types. Multifocal areas of discrete necrosis were also observed, compatible with a sarcomatous proliferation. The immunological parameters analysed suggested an inflammatory response. No bacteria were isolated from the hematopoietic organs. However, Vibrio species, components of the normal seawater flora, were isolated from the tumour, which may have had a role in eliciting the immune response. No evidence of viral pathogens was found by electron microscopy. In order to look for cytogenetic alterations often linked to sarcomas, the diploid number and karyotype of this species were determined for the first time. An increase in the aneuploidy level was observed in sarcoma cell metaphase stages compared to other tissues. The aetiology of this tumour remains unknown.
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Correia S, Reis A, Goodbourn S, Leitão A, Parkhouse R. PS1-106 Inhibition of interferon responses by African Swin Fever Virus. Cytokine 2011. [DOI: 10.1016/j.cyto.2011.07.139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Pereira JC, Lino PG, Leitão A, Joaquim S, Chaves R, Pousãao-Ferreira P, Guedes-Pinto H, Santos MND. Genetic differences between wild and hatchery populations ofDiplodus sargus andD. vulgaris inferred from RAPD markers: implications for production and restocking programs design. J Appl Genet 2010; 51:67-72. [DOI: 10.1007/bf03195712] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Gil S, Sepúlveda N, Potier M, Leitão A, Michaud V, Albina E, Martins C. Induction of inflammatory and Th1 cytokines in pigs inoculated with the low virulent ASFV/NH/p68 (NHV). Cytokine 2009. [DOI: 10.1016/j.cyto.2009.07.203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bouilly K, Chaves R, Leitão A, Benabdelmouna A, Guedes-Pinto H. Chromosomal organization of simple sequence repeats in the Pacific oyster (Crassostrea gigas): (GGAT)(4), (GT)(7) and (TA)(10) chromosome patterns. J Genet 2008; 87:119-25. [PMID: 18776639 DOI: 10.1007/s12041-008-0018-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Chromosome identification is essential in oyster genomic research. Fluorescence in situ hybridization (FISH) offers new opportunities for the identification of oyster chromosomes. It has been used to locate satellite DNAs, telomeres or ribosomal DNA sequences. However, regarding chromosome identification, no study has been conducted with simple sequence repeats (SSRs). FISH was used to probe the physical organization of three particular SSRs, (GGAT)(4), (GT)(7) and (TA)(10) onto metaphase chromosomes of the Pacific oyster, Crassostrea gigas. Hybridization signals were observed in all the SSR probes, but the distribution and intensity of signals varied according to the oligonucleotide repeat. The intercalary, centromeric and telomeric bands were observed along the chromosomes, and for each particular repeat every chromosome pair presented a similar pattern, allowing karyotypic analysis with all the SSRs tested. Our study is the first in mollusks to show the application of SSR in situ hybridization for chromosome identification and karyotyping. This technique can be a useful tool for oyster comparative studies and to understand genome organization in different oyster taxa.
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Affiliation(s)
- K Bouilly
- Institute for Biotechnology and Bioengineering, Centre of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, (IBB/CGB-UTAD), 5001-801 Vila Real, Portugal.
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Gil S, Sepúlveda N, Albina E, Leitão A, Martins C. The low-virulent African swine fever virus (ASFV/NH/P68) induces enhanced expression and production of relevant regulatory cytokines (IFNalpha, TNFalpha and IL12p40) on porcine macrophages in comparison to the highly virulent ASFV/L60. Arch Virol 2008; 153:1845-54. [PMID: 18787755 PMCID: PMC2831186 DOI: 10.1007/s00705-008-0196-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Accepted: 07/30/2008] [Indexed: 01/03/2023]
Abstract
The impact of infection by the low-virulent ASFV/NH/P68 (NHV) and the highly virulent ASFV/L60 (L60) isolates on porcine macrophages was assessed through the quantification of IFNα, TNFα, IL12p40, TGFβ and ASFV genes by real-time PCR at 2, 4 and 6 h post-infection. Increased IFNα, TNFα and IL12p40 expression was found in infection with NHV, in which expression of TGFβ was lower than in infection with L60. Principal component analysis showed a positive interaction of cytokines involved in cellular immune mechanisms, namely IFNα and IL12p40 in the NHV infection. Quantification by ELISA confirmed higher production of IFNα, TNFα and IL12p40 in the NHV-infected macrophages. Overall, our studies reinforce and clarify the effect of the NHV infection by targeting cellular and cellular-based immune responses relevant for pig survival against ASFV infection.
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Affiliation(s)
- S. Gil
- Laboratório de Doenças Infecciosas, CIISA, Faculdade de Medicina Veterinária, Technical University of Lisbon (TULisbon), Av. da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - N. Sepúlveda
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Center of Statistics and Applications, University of Lisbon, Lisbon, Portugal
- Escola Superior de Saúde Egas Moniz and Instituto Superior de Ciências da Saúde Egas Moniz, Monte da Caparica, Lisbon, Portugal
| | - E. Albina
- CIRAD, UMR Contrôle des Maladies, Montpellier, 34398 France
| | - A. Leitão
- Instituto de Investigação Científica Tropical, CVZ, CIISA, Av. da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - C. Martins
- Laboratório de Doenças Infecciosas, CIISA, Faculdade de Medicina Veterinária, Technical University of Lisbon (TULisbon), Av. da Universidade Técnica, 1300-477 Lisbon, Portugal
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Cortes HCE, Mueller N, Esposito M, Leitão A, Naguleswaran A, Hemphill A. In vitro efficacy of nitro- and bromo-thiazolyl-salicylamide compounds (thiazolides) against Besnoitia besnoiti infection in Vero cells. Parasitology 2007; 134:975-85. [PMID: 17306057 DOI: 10.1017/s0031182007002417] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Nitazoxanide (NTZ) and its deacetylated metabolite tizoxanide (TIZ) exhibit considerable in vitro activity against Besnoitia besnoiti tachyzoites grown in Vero cells. Real-time-PCR was used to assess B. besnoiti tachyzoite adhesion, invasion, and intracellular proliferation in vitro. A number of NTZ-derivatives, including Rm4822 and Rm4803, were generated, in which the thiazole-ring-associated nitro-group was replaced by a bromo-moiety. We here show that replacement of the nitro-group on the thiazole ring with a bromo (as it occurs in Rm4822) does not impair the efficacy of the drug, but methylation of the salicylate ring at the ortho-position in a bromo-derivative (Rm4803) results in complete abrogation of the antiparasitic activity. Treatment of extracellular B. besnoiti tachyzoites with NTZ has an inhibitory effect on host cell invasion, while treatments with TIZ, Rm4822 do not. TEM demonstrates that the effects of Rm4822 treatment upon the parasites are similar to the damage induced by NTZ. This includes increased vacuolization of the parasite cytoplasm, and loss of the structural integrity of the parasitophorous vacuole and its membrane. Thus, Rm4822, due to the absence of a potentially mutagenic nitro-group, may represent an important potential addition to the anti-parasitic arsenal for food animal production, especially in cattle.
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Affiliation(s)
- H C E Cortes
- Laboratório de Parasitologia Victor Caeiro, Núcleo da Mitra, ICAM, Universidade de Evora, Apartado 94, 7000-554 Evora, Portugal.
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Cortes HCE, Reis Y, Waap H, Vidal R, Soares H, Marques I, Pereira da Fonseca I, Fazendeiro I, Ferreira ML, Caeiro V, Shkap V, Hemphill A, Leitão A. Isolation of Besnoitia besnoiti from infected cattle in Portugal. Vet Parasitol 2006; 141:226-33. [PMID: 16822614 DOI: 10.1016/j.vetpar.2006.05.022] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2005] [Revised: 04/28/2006] [Accepted: 05/11/2006] [Indexed: 10/24/2022]
Abstract
Besnoitia besnoiti, an obligate intracellular protozoan parasite belonging to the phylum apicomplexa, is the causative agent of bovine besnoitiosis. Besnoitiosis is responsible for significant losses in the cattle industry of Africa and Mediterranean countries due to the high morbidity rate, abortion and infertility in males. The acute stage of disease is associated with the proliferative forms (tachyzoites) and is characterized by fever, whimpery, general weakness and swelling of the superficial lymph nodes. During the following chronic stage, a huge number of cysts are formed mainly in the subcutaneous tissues. This process is non-reversible, and chronic besnoitiosis is characterized by hyper-sclerodermia, hyperkeratosis, alopecia and, in bulls, atrophy, sclerosis and focal necrosis that cause irreversible lesions in the testis. In this paper we report on the identification of large cysts in the skin of a cow and a bull in Portugal, which presented loss of hair and enlargement and pachydermis all over the body. The observation of a two-layered cyst wall within the host cell, the encapsulation of the host cell by a large outer cyst wall, and the subcutaneous localization of the cysts within the host, were characteristic for B. besnoiti. The parasites were isolated from the infected animals and successfully propagated in Vero cells without prior passages in laboratory animals. Morphological characterization of B. besnoiti tachyzoites and the amplification of the 149 bp segment from the internal transcribed spacer 1 (ITS1), aided with specific primers, confirmed the identification of B. besnoiti.
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Affiliation(s)
- H C E Cortes
- Laboratório de Parasitologia, ICAM, Núcleo da Mitra, Universidade de Evora, Ap 94, Evora 7002-554, Portugal.
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15
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Reis Y, Cortes H, Viseu Melo L, Fazendeiro I, Leitão A, Soares H. Microtubule cytoskeleton behavior in the initial steps of host cell invasion byBesnoitia besnoiti. FEBS Lett 2006; 580:4673-82. [PMID: 16876796 DOI: 10.1016/j.febslet.2006.07.050] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2006] [Accepted: 07/13/2006] [Indexed: 11/30/2022]
Abstract
Besnoitia besnoiti is a protozoan parasite responsible for bovine besnoitiosis. Indirect immunofluorescence showed that isolated B. besnoiti possesses a set of subpellicular microtubules, radiating from the apical end and extending for more than 2/3 of the cell body. Upon interaction with the host cell, B. besnoiti undergoes dramatic modifications of shape and surface, as revealed by atomic force microscopy, accompanied by a distinct tubulin labeling on the posterior region. In the host cell, the microtubule cytoskeleton shows a re-arrangement around the invading parasite suggesting a filamentous interaction with the parasite cytoskeleton during invasion.
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Affiliation(s)
- Y Reis
- Instituto de Investigação Científica Tropical, CVZ, CIISA, Av. Universidade Técnica, Lisboa 1300-477, Portugal
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16
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Cortes HCE, Nunes S, Reis Y, Staubli D, Vidal R, Sager H, Leitão A, Gottstein B. Immunodiagnosis of Besnoitia besnoiti infection by ELISA and Western blot. Vet Parasitol 2006; 141:216-25. [PMID: 16822616 DOI: 10.1016/j.vetpar.2006.05.023] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 05/01/2006] [Accepted: 05/15/2006] [Indexed: 11/28/2022]
Abstract
Besnoitia besnoiti, an obligate intracellular apicomplexan protozoan parasite, is the causative agent of bovine besnoitiosis. This infection may dramatically affect body condition and lead to irreversible infertility in males, resulting in important economical losses in livestock production. Identification of serologically positive animals is of major relevance to elaborate appropriate measures of control. While identification of clinical cases is relatively easy to carry out, the finding of subclinical forms of infection is more difficult, thus serology is considered as an appropriate diagnostic tool. In view to improve and validate immunodiagnosis, we evaluated an enzyme-linked immunosorbent assay (ELISA), complemented with a Western blot (both using a somatic B. besnoiti-tachyzoite antigen) to detect anti-B. besnoiti antibodies in bovine sera. The comparative evaluation of the 2 methods, using 13 sera from animals affected by the chronic phase of besnoitiosis and 10 asymptomatic carriers, yielded a diagnostic sensitivity of 87% for ELISA and 91% for Western blot analyses. Specificity was tested with sera from animals with confirmed Toxoplasma gondii (n=5) and Neospora caninum (n=12) infection, and with 64 negative sera from either an endemic or a non-endemic area. The ELISA specificity ranged between 96.4% and 98%, the Western blot specificity between 96.4% and 100%. The present study demonstrated that ELISA and Western blot, using in vitro generated somatic B. besnoiti antigen, is a useful tool combination to reliably detect animals that have been exposed to B. besnoiti infection, including both asymptomatic and symptomatic courses of disease.
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Affiliation(s)
- H C E Cortes
- Laboratório de Parasitologia, Núcleo da Mitra, ICAM, Universidade de Evora, Apartado 94, 7000-554 Evora, Portugal
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17
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Montanari MLC, Cass QB, Leitão A, Andricopulo AD, Montanari CA. The role of molecular interaction fields on enantioselective and nonselective separation of chiral sulfoxides. J Chromatogr A 2006; 1121:64-75. [PMID: 16716332 DOI: 10.1016/j.chroma.2006.04.072] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Revised: 03/30/2006] [Accepted: 04/05/2006] [Indexed: 11/30/2022]
Abstract
The separation of a series of 23 asymmetric sulfoxides, including the three proton pump inhibitors (PPI) omeprazole, lansoprazole and pantoprazole was investigated by HPLC, under reversed-phase elution with amylose tris(3,5-dimethylphenylcarbamate), amylose tris[(S)-1-phenylethylcarbamate] and amylose tris(3,5-dimethoxyphenylcarbamate) chiral stationary phases, CSP1-3, respectively. The whole set of sulfoxides showed better enantioselectivity and enantioresolution on CSP1. However, the three PPI were enantioseparated only when using CSP1 and CSP3. It was observed an improved enantioselectivity and enantioresolution on CSP3. The mechanisms of retention were evaluated by molecular interaction fields (MIF) generated via GRID force field, which yielded the geometric reasons leading to the scenario outlined. The enantioselective and nonselective interactions are discussed in terms of the reported selectivity. The steric structural outline of the CSP nonselective interaction sites is of major importance to deliver the sulfoxides to the chiral selective sites where the enantioselective interactions take place.
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Affiliation(s)
- M L C Montanari
- Departamento de Química, Universidade Federal de São Carlos, P.O. Box 676, 13565-905 São Carlos/SP, Brazil
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18
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Basto AP, Portugal RS, Nix RJ, Cartaxeiro C, Boinas F, Dixon LK, Leitão A, Martins C. Development of a nested PCR and its internal control for the detection of African swine fever virus (ASFV) in Ornithodoros erraticus. Arch Virol 2005; 151:819-26. [PMID: 16328146 DOI: 10.1007/s00705-005-0654-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Accepted: 08/31/2005] [Indexed: 10/25/2022]
Abstract
A nested PCR assay, with an internal control, was developed to detect African swine fever virus (ASFV) DNA in Ornithodoros erraticus. The assay revealed a better analytical sensitivity than virus isolation and the OIE PCR protocol. All ticks collected from the field, which were positive by virus isolation, were also positive by PCR. Viral DNA was detected in a further 19 out of 60 ticks from which no virus was isolated. Our results show that this assay is reliable and can easily be used to screen large tick populations collected in the field for the presence of ASFV.
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Affiliation(s)
- A P Basto
- Laboratório de Doenças Infecciosas, CIISA, Faculdade de Medicina Veterinária, Lisboa, Portugal
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19
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Affiliation(s)
- H Cortes
- Laboratório de Parasitologia, Instituto de Cifencias Agrárias Mediterrânicas (ICAM), Mitra, Universidade de Evora, Apartado 94, 7000-554 Evora, Portugal
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20
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Leitão A, Chaves R, Santos S, Guedes-Pinto H, Boudry P. Restriction enzyme digestion chromosome banding in Crassostrea and Ostrea species: comparative karyological analysis within Ostreidae. Genome 2005; 47:781-8. [PMID: 15499392 DOI: 10.1139/g04-035] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reliable banding techniques are a major necessity for genetic research in oysters. In this study, we carried out the cytogenetic characterization of four oyster species (family Ostreidae) using restriction endonuclease treatments. Chromosomes were treated with three different restriction enzymes, stained with Giemsa, and examined for banding patterns. The following species were studied: Crassostrea gigas (2n = 20; total number of bands with ApaI, 74; HaeIII, 61; PstI, 76), Crassostrea angulata (2n = 20; ApaI, 62; HaeIII, 61; PstI, 55) (subfamily Crassostreinae), Ostrea edulis (2n = 20; ApaI, 82; HaeIII, 59; PstI, 66), and Ostrea conchaphila (2n = 20; ApaI, 68; HaeIII, 62; PstI, 69) (subfamily Ostreinae). Treatment of samples with ApaI, HaeIII, and PstI produced specific banding patterns, which demonstrates the potential of these enzymes for chromosome banding in oysters. This is of special interest, since it has been recently shown in mammalian chromosomes that restriction enzyme banding is compatible with fluorescence in situ hybridization. This study therefore provides a fundamental step in genome mapping of oysters, since chromosome banding with restriction enzymes facilitates physical gene mapping in these important aquaculture species. The analysis of the banded karyotypes revealed a greater similarity within the genera of Crassostrea and Ostrea than between them.
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Affiliation(s)
- A Leitão
- Laboratoire de Génétique et Pathologie, Station de l'Institut pour la Recherche et l'Exploitation de la Mer (IFREMER), 17390 La Tremblade, France
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21
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Gil S, Spagnuolo-Weaver M, Canals A, Sepúlveda N, Oliveira J, Aleixo A, Allan G, Leitão A, Martins CLV. Expression at mRNA level of cytokines and A238L gene in porcine blood-derived macrophages infected in vitro with African swine fever virus (ASFV) isolates of different virulence. Arch Virol 2003; 148:2077-97. [PMID: 14579171 DOI: 10.1007/s00705-003-0182-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Porcine macrophage cultures were infected with two ASFV isolates of variable virulence and mRNA levels of several relevant macrophage-derived cytokines were quantified by real time PCR. At six hours post infection, a clear enhancement of mRNA expression of TNFalpha, IL6, IL12 and IL15 was observed in macrophages infected with the low virulent ASFV/NH/P68 (NHV) when compared to those infected with the highly virulent ASFV/L60 (L60). The sequence of the A238L gene homologue to the cellular IkappaB was found identical in both viral isolates and its expression at mRNA level was higher in macrophages infected with NHV when compared to macrophages infected with L60. Furthermore our results suggest a negative correlation between the mRNA expression of A238L gene and the mRNA expression of the above mentioned cytokines (with the exception of IL10) in L60 infected macrophages in opposition to the positive correlation (with exception of the IL1) suggested in NHV infection. Overall, our data strongly emphasize that virulence of ASFV isolates may depend on their capacity to regulate the expression of macrophage-derived cytokines relevant for the development of host protective responses by yet unknown mechanisms triggered by the virus at early stages of the cellular infection.
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Affiliation(s)
- S Gil
- Laboratório Doenças Infecciosas, CIISA, Faculdade de Medicina Veterinária, Lisboa, Portugal
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22
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Lapègue S, Boutet I, Leitão A, Heurtebise S, Garcia P, Thiriot-Quiévreux C, Boudry P. Trans-atlantic distribution of a mangrove oyster species revealed by 16S mtDNA and karyological analyses. Biol Bull 2002; 202:232-242. [PMID: 12086994 DOI: 10.2307/1543473] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three species of mangrove oysters, Crassostrea rhizophorae, C. brasiliana, and C. gasar, have been described along the Atlantic shores of South America and Africa. Because the distribution of these molluscs is of great biological and commercial interest, their taxonomy and distribution deserve further clarification. Therefore, 15 populations were sampled from both continents. Their 16S mitochondrial polymorphism was studied by sequencing and PCR-RFLP analysis. Two haplotypes were identified. Haplotype a was the only one observed in Africa, but it was also observed in South America together with haplotype b. Because C. gasar is the only mangrove oyster identified on the west coast of Africa, haplotype a was attributed to this species, which has thus been shown to occur in South America. Haplotype b is attributed to C. rhizophorae. The karyotypes of specimens of C. gasar, from Africa and from South America, were very similar, and both species were observed at the same location in Brazil. The occurrence of C. gasar in South America adds a third species-in addition to C. rhizophorae and C. brasiliana-to the list of species present along these coasts. The predominant surface circulation patterns in this part of the Atlantic Ocean favor the hypothesis that C. gasar was transported from Africa to America. Finally, a phylogenetic tree built with seven 16S sequences from Crassostrea and Saccostrea species showed that C. gasar is intermediate between the American Crassostrea species (C. virginica and C. rhizophorae) and the Asian species (C. gigas and C. ariakensis).
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Affiliation(s)
- S Lapègue
- IFREMER, Laboratoire de Génétique et Pathologie, B.P. 133, 17390 La Tremblade, France.
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23
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Leitão A, Boudry P, Thiriot-Quiévreux C. Evidence of differential chromosome loss in aneuploid karyotypes of the Pacific oyster, Crassostrea gigas. Genome 2001; 44:735-7. [PMID: 11550911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The G-banding technique was performed on aneuploid karyotypes from gill tissue of the Pacific oyster, Crassostrea gigas, to assess whether chromosome losses could be explained by differential chromosomal susceptibility and to clarify the negative correlation between aneuploidy and growth rate previously reported in different populations of this oyster. The study of 95 G-banded aneuploid karyotypes showed that only 4 of the 10 chromosome pairs (viz. 1, 5, 9, and 10) of C. gigas were affected by the loss of one homologous chromosome. Pairs 1, 9, and 10, which were lost in 56, 33, and 44% of cases, respectively, may be considered to be differentially affected. Hypotheses on this differential chromosomal susceptibility are discussed.
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Affiliation(s)
- A Leitão
- Observatoire Océanologique, Université Pierre et Marie Curie, Centre National de la Recherche Scientifique, BP 28, Villefranche-sur-Mer, France
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Leitão A, Boudry P, Thiriot-Quiévreux C. Evidence of differential chromosome loss in aneuploid karyotypes of the Pacific oyster, Crassostrea gigas. Genome 2001. [DOI: 10.1139/g01-035] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The G-banding technique was performed on aneuploid karyotypes from gill tissue of the Pacific oyster, Crassostrea gigas, to assess whether chromosome losses could be explained by differential chromosomal susceptibility and to clarify the negative correlation between aneuploidy and growth rate previously reported in different populations of this oyster. The study of 95 G-banded aneuploid karyotypes showed that only 4 of the 10 chromosome pairs (viz. 1, 5, 9, and 10) of C. gigas were affected by the loss of one homologous chromosome. Pairs 1, 9, and 10, which were lost in 56, 33, and 44% of cases, respectively, may be considered to be differentially affected. Hypotheses on this differential chromosomal susceptibility are discussed.Key words: aneuploidy, growth, G-banding, karyotype, oyster.
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25
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Leitão A, Boudry P, Thiriot-Quiévreux C. Evidence of differential chromosome loss in aneuploid karyotypes of the Pacific oyster, Crassostrea gigas. Genome 2001. [DOI: 10.1139/gen-44-4-735] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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26
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Leitão A, Malur A, Cartaxeiro C, Vasco G, Cruz B, Cornelis P, Martins CL. Bacterial lipoprotein based expression vectors as tools for the characterisation of African swine fever virus (ASFV) antigens. Arch Virol 2000; 145:1639-57. [PMID: 11003474 DOI: 10.1007/s007050070081] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
African swine fever virus (ASFV) is the causative agent of an important pig disease for which protective mechanisms are still poorly understood. The present work was aimed at the characterisation of ASFV antigens using previously reported vectors that allow their expression as fusion proteins with the bacterial lipoprotein OprI. Several recombinant clones induced SLA-restricted, ASFV-specific lymphoproliferation and one (A2) was demonstrated to stimulate ASFV-specific CTL activity in vitro, in opposition to the effect of UV inactivated virus. The nucleotide sequence of the fragment cloned in A2 showed 99% identity with a portion of the G1340L ORF of the BA71V isolate, and the expressed fusion lipoprotein induced specific antibodies in vivo. Blood mononuclear leukocytes from a pig immunised with outer membrane preparations from A2 showed to reduce strongly (99.6%) the ASFV yield in cultures of autologous macrophages. However, after inoculation with virulent virus the pig developed acute fatal ASF. Overall our results show that OprI based expression vectors are valuable tools to screen viral antigens in terms of their capacity to trigger immune competent cells.
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Affiliation(s)
- A Leitão
- Laboratório de Doenças Infecciosas, CIISA, Faculdade de Medicina Veterinária, Lisbon, Portugal
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27
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Leitão A, Malur A, Cornelis P, Martins CL. Identification of a 25-aminoacid sequence from the major African swine fever virus structural protein VP72 recognised by porcine cytotoxic T lymphocytes using a lipoprotein based expression system. J Virol Methods 1998; 75:113-9. [PMID: 9820580 DOI: 10.1016/s0166-0934(98)00105-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Identification of African swine fever virus (ASFV) proteins recognised by cytotoxic T lymphocytes (CTL) from swine surviving ASFV/NH/P68 infection was assessed using expression vectors based on the Pseudomonas aeruginosa outer membrane lipoprotein I gene (oprI). Viral antigens expressed as fusion lipoproteins were shown to be taken efficiently by porcine blood-derived macrophages incubated with outer membrane protein preparations from transformed E. coli. To assess recognition by CTL the fusion lipoprotein-treated macrophages were used as targets in 51Cr release microcytotoxicity assays. Using this approach it was shown that the aminoacid sequence HKPHQSKPILTDENDTQRTCSHTNP from the major structural ASFV protein (VP72), encoded by a recombinant clone (pVUB72) is presented by macrophages, which are lysed under restriction of SLA class I antigens. Overall, the results demonstrate that the oprI based vectors are valuable tools to study ASFV-specific CTL activity.
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Affiliation(s)
- A Leitão
- Laboratório de Doenças Infecciosas, CIISA, Faculdade de Medicina Veterinária, Lisboa, Portugal
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28
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Cornelis P, Sierra JC, Lim A, Malur A, Tungpradabkul S, Tazka H, Leitão A, Martins CV, di Perna C, Brys L, De Baetseller P, Hamers R. Development of new cloning vectors for the production of immunogenic outer membrane fusion proteins in Escherichia coli. Biotechnology (N Y) 1996; 14:203-8. [PMID: 9636324 DOI: 10.1038/nbt0296-203] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Pseudomonas aeruginosa lipoprotein gene (oprI) was modified by cloning an in-frame polylinker in both orientations at the end of oprI. The resulting plasmids pVUB1 and pVUB2 allow high lipoprotein production in E. coli after IPTG induction. The modified lipoproteins are present in the outer membrane and surface-exposed. Outer membrane-bound fusion proteins of different sizes were produced and used to generate antibodies without use of adjuvant. An 87 bp DNA fragment from the vp72 capsid protein gene of African Swine Fever virus (ASFV) and the entire Leishmania major glycoprotein gp63 gene were expressed in this system. Finally, a fusion lipoprotein containing a 16 amino acid epitope from the pre-S2b region of Hepatitis B virus (HBV) was presented by an antigen-presenting cell line to a T-cell hybridoma while the corresponding cross-linked S2b peptide was not. The results suggest that OprI-based fusion proteins can be used to generate both humoral and cellular immune responses.
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Affiliation(s)
- P Cornelis
- Laboratorium Algemene Biologie, Vrije Unviersiteit Brussel Vlaams Instituut Biotechnologie, Belgium.
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Resina T, Pinhão A, Neto L, Leitão A, Martins J, Augusto M. [Depression and anxiety in general practice and family medicine consultation]. ACTA MEDICA PORT 1989; 2:7-11. [PMID: 2773679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The aim of this work was to study depression and anxiety in outpatients of Family Practice, namely: definition of cases, caseness, point-prevalence, clinical features, correlations with social demographic factors and identification of risk groups for those psychological disorders. Therapeutic attitudes displayed by family practitioners were also evaluated. The results of the study reveal a high prevalence of depression in family medicine settings and a relative tendency of family doctors to underdiagnose case of depression. Such an evidence allows the authors to conclude that steps should be taken in order to provide training programs for family practitioners and to plan appropriate treatment programmes at public Health Centres.
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31
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Baptista AP, Tellechea O, Aguiar M, Leitão A. [Glucagonoma syndrome]. ACTA MEDICA PORT 1988; 1:141-4. [PMID: 2849865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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32
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33
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Leitão A. [Importance of the department of the history of medicine in the medical curriculum]. Rev Port Estomatol Cir Maxilofac 1984; 25:999-1019. [PMID: 6396809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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34
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Poiares Baptista A, Vasconcelos A, Freitas JD, Leitão A. [Keratoacanthoma centrifugum marginatum]. Med Cutan Ibero Lat Am 1984; 12:177-181. [PMID: 6374328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The authors describe an observation of multiple keratoacanthomas appearing within 3 years, mainly located on the right forearm. Clear confluence and centrifugal extension, due to progressive appearance of surrounding lesions forming a 12 X 10 cm. ulcerated surface characterized this case. The topical application of 5-FU was effective, nevertheless further surrounding lesions have made their appearance. The clinico-pathological features and evolution are those of keratoacanthoma centrifugum marginatum , a rare type of multiple and localized keratoacanthoma.
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35
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Caldas LR, Menezes S, Leitão A, Latarjet R. [Antiviral action by photodynamic effect on bacterial systems: special sensitivity of infected bacteria]. C R Acad Hebd Seances Acad Sci D 1974; 278:2369-72. [PMID: 4277776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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