786 research outputs found
A paisagem Duriense em Vale Abraão de Agustina Bessa-Luís e Manoel de Oliveira
Get PDFPretende-se analisar a paisagem Duriense e os socalcos de vinhas que abraçam o rio, que em Vale Abrãao de Agustina encontram o seu duplo em Ema — O rio é uma mulher, essa mulher é Ema Caldeano Paiva; e que, no caso de Oliveira, nos travellings, e nos planos gerais e médios conferem ao rio Douro e à paisagem envolvente, o relevo de personagem princi- pal, igualmente espelho dos vários cambiantes da personagem Ema.
Vale Abrãao é o resultado de um desafio proposto por Oliveira a Agustin
Use of the recombinant EMA-2 protein of Theileria equi expressed in Pichia pastoris, as immunobiological
No full textTheileriosis, endemic disease in Brazil, is a piroplasmosis caused by intra-erythrocytic protozoan, Theileria equi. Causes losses associated with both clinical factors and restriction on the movement of positive animals. Transmission of T. equi occurs mainly during tick feeding which inoculates their infective forms (sporozoites) in horses, which are the vertebrate hosts. The diagnosis and prevention of this disease is needed in endemic and non endemic areas due to the presence of vectors and protozoa. Different ELISAs platforms have been developed using recombinant antigens. EMA-2 is released into the cytoplasm and erythrocyte membrane, suggesting that one of the first antigens recognized by the immune system. The aim of this study was to evaluate the EMA-2 protein of Theileria equi, expressed in Pichia pastoris, as immunobiological. After expression of EMA-2 glycoprotein, an indirect ELISA was developed. The ELISA demonstrated sensitivity of 90.9% and specificity of 83.3% when compared to the commercial kit cELISA. The protein also showed immunogenicity when test the sera of immunized mice with recombinant EMA-2 by immunofluorescence. As the EMA-2 protein antigenic and immunogenic, it may be used diagnostic tests as well as a promising antigen for the development of subunit vaccines.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESA theileriose, doença endêmica no Brasil, é uma piroplasmose causada pelo protozoário intraeritrocitário, Theileria equi. Provoca perdas associadas tanto a fatores clínicos como a restrição ao trânsito de animais soropositivos. A transmissão de T. equi ocorre principalmente no repasto do carrapato, o qual inocula suas formas infectantes (esporozoítos) nos equídeos, que são os hospedeiros vertebrados. O diagnóstico e a prevenção desta enfermidade se fazem necessários em áreas endêmicas e não endêmicas devido à disseminação dos vetores e do protozoário e de sua alta prevalência. Diferentes plataformas de ELISAs têm sido desenvolvidas com a utilização de antígenos recombinantes. A proteína de superfície de merozoíto EMA-2 é liberada no citoplasma e na membrana do eritrócito, sugerindo ser um dos primeiros antígenos reconhecidos pelo sistema imune. O objetivo desse estudo foi avaliar a proteína EMA-2 de Theileria equi, expressa em Pichia pastoris, como imunobiológico. Após expressão da glicoproteína EMA-2 foi desenvolvido um ELISA indireto. O ELISA demonstrou sensibilidade de 90,9% e especificidade de 83,3% quando comparado ao kit comercial de cELISA. A proteína também demonstrou imunogenicidade ao testarmos soros de camundongos imunizados com EMA-2 recombinante, por imunofluorescência. Sendo a proteína EMA-2 antigênica e imunogênica, poderá ser usada, além dos testes de diagnóstico, como antígeno para o desenvolvimento de vacinas de subunidade
Use of the recombinant EMA-2 protein of Theileria equi expressed in Pichia pastoris, as immunobiological
No full textTheileriosis, endemic disease in Brazil, is a piroplasmosis caused by intra-erythrocytic protozoan, Theileria equi. Causes losses associated with both clinical factors and restriction on the movement of positive animals. Transmission of T. equi occurs mainly during tick feeding which inoculates their infective forms (sporozoites) in horses, which are the vertebrate hosts. The diagnosis and prevention of this disease is needed in endemic and non endemic areas due to the presence of vectors and protozoa. Different ELISAs platforms have been developed using recombinant antigens. EMA-2 is released into the cytoplasm and erythrocyte membrane, suggesting that one of the first antigens recognized by the immune system. The aim of this study was to evaluate the EMA-2 protein of Theileria equi, expressed in Pichia pastoris, as immunobiological. After expression of EMA-2 glycoprotein, an indirect ELISA was developed. The ELISA demonstrated sensitivity of 90.9% and specificity of 83.3% when compared to the commercial kit cELISA. The protein also showed immunogenicity when test the sera of immunized mice with recombinant EMA-2 by immunofluorescence. As the EMA-2 protein antigenic and immunogenic, it may be used diagnostic tests as well as a promising antigen for the development of subunit vaccines.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESA theileriose, doença endêmica no Brasil, é uma piroplasmose causada pelo protozoário intraeritrocitário, Theileria equi. Provoca perdas associadas tanto a fatores clínicos como a restrição ao trânsito de animais soropositivos. A transmissão de T. equi ocorre principalmente no repasto do carrapato, o qual inocula suas formas infectantes (esporozoítos) nos equídeos, que são os hospedeiros vertebrados. O diagnóstico e a prevenção desta enfermidade se fazem necessários em áreas endêmicas e não endêmicas devido à disseminação dos vetores e do protozoário e de sua alta prevalência. Diferentes plataformas de ELISAs têm sido desenvolvidas com a utilização de antígenos recombinantes. A proteína de superfície de merozoíto EMA-2 é liberada no citoplasma e na membrana do eritrócito, sugerindo ser um dos primeiros antígenos reconhecidos pelo sistema imune. O objetivo desse estudo foi avaliar a proteína EMA-2 de Theileria equi, expressa em Pichia pastoris, como imunobiológico. Após expressão da glicoproteína EMA-2 foi desenvolvido um ELISA indireto. O ELISA demonstrou sensibilidade de 90,9% e especificidade de 83,3% quando comparado ao kit comercial de cELISA. A proteína também demonstrou imunogenicidade ao testarmos soros de camundongos imunizados com EMA-2 recombinante, por imunofluorescência. Sendo a proteína EMA-2 antigênica e imunogênica, poderá ser usada, além dos testes de diagnóstico, como antígeno para o desenvolvimento de vacinas de subunidade
“Per ELISA”: Time to adopt anti-transglutaminase/deamidated gliadin peptide diagnostic combination in coeliac disease of adults?
No full textBackground: Anti-endomysial antibodies (EMA) and anti-tissue transglutaminases (a-tTg) play a pivotal role in coeliac disease (CD) diagnosis. Deamidated anti-gliadin peptides (DGP) were added to the CD diagnostic workup. Aims: We aimed to compare the diagnostic accuracies of ELISA-based (a-tTg/DGP) and immunofluorescence–ELISA-based strategies (EMA/a-tTg) for CD diagnosis. Methods: From November 2020 to November 2022, we undertook an observational prospective study including consecutive adult patients with suspected CD. All subjects were tested for EMA, a-tTg and DGP IgA. An ROC curve was plotted to establish the best specificity cut-off of a-tTg and DGP levels, which would predict the presence of Marsh≥2 and Marsh=3. The diagnostic accuracies of a-tTg/DG and EMA/a-tTg were compared. Results: The study included 275 CD patients. Histology showed Marsh=1 in 9.9%, Marsh=2 in 4.5%, and Marsh=3 in 85.6.%. The best cut-off value of a-tTg for predicting Marsh≥2 was 42 U/mL, while the best cut-off for predicting atrophy was 68.4 U/mL. The best cut-off value of DGP for predicting Marsh≥2 was 56 U/mL, while the best cut-off for predicting atrophy was 78 U/mL. A-tTg/EMA showed 97% sensitivity and 100% specificity, whereas a-tTg/DGP showed 94% sensitivity and 100% specificity. Conclusion: A-tTg/DGP is accurate for CD diagnosis and could reduce costs and operator-dependency of EMA. DGP, together with a-tTg, could replace EMA in CD diagnosis
Unexpected behavior of diastereomeric ions in the gas phase: a stimulus for pondering on ee Measurements by ESI-MS
No full textThe most common protocols for the quantitative determination of the enantiomeric excess (ee) of raw mixtures by ESI-MS reveal inadequate in cases where the distribution of diastereomeric derivatives diverges from the ee of original solutions. This phenomenon is attributable to a matrix effect, i.e., to the stereospecific formation of high order noncovalent adducts in the ESI droplets, which alters the actual availability of the diastereomeric species under MS analysis. In this frame, the assumption of classic protocols that the ionization correction factor q is independent on the composition of the mixture submitted to analysis is questionable. An alternative methodology is presented in this paper, which is aimed at circumventing the problem by excluding any chemical derivatization of the original raw mixture. It is based on the measurement of the actual distribution of ESI-formed proton-bound diastereomeric complexes from the enantiomeric mixture through a careful analysis of their reaction kinetics with a suitable reactant
Structure and reactivity of supramolecular systems acting as highly selective "chemo-logic" devices in the gas phase
No full textThe present kinetic and IRMPD spectroscopic study demonstrated that the chiral macrocycle Chirabite-A (M) behaves in the gas phase as a selective template for aromatic amino acids (G). In the presence of amines (A = 2-aminobutane or piperidine), its proton-bound diastereomeric [M:H:G]’ complexes (G = phenylglycine, phenylalanine, tryptophan, dopa, and naphthylalanine), undergo time-dependent monoexponential decays with formation of the corresponding substitutioe ([M-H-A]) product, sometimes accompanied by the addition ([M:H:-G-AT7 derivative. Depending upon the nature and the configuration of G and A, ibe kinetic curves exhibit a plateau revealing the presence of unreactive [M:H:GI structures. In them, the amino acid is accommodated inside the macrocycle cavity in the zwitterionic form by sharing its acidic hydrogen atoms with the pyridine nitrogen atoms of the host. The same interactions are structurally inaccessible to dipeptides or monofunctional amines, which then can be readily released from their complexes. When the amino acid interacts with the amidocarbonyl oxygen atoms pointing outside the Chirabite-A cavity, it saves the canonical structure and can be readily displaced by amine A. The occurrence of isomeric forms has beeg confirmed by variable wavelength IRMPD spectroscopy. The structural and kinetic properties of diastereomeric [M:H:G]' complexes (G = aromatic amino acid) confer to them the features of “chemo-logic” device in the gas phase. Depending on the relative configuration of the M/G pair and the nature of the amine A, the loss of the amino acid may occur ("Logic-gate"). Furthermore, the logic output of a given [M:H:G]° diastereomer may depend upon the specific reaction threshold chosen (multi-output “logic gate”)
Multifunctional macrocyclic receptors as templates for aromatic amino acids: a rare example of a highly selective multi-input multi-output chemo-"logic gate"
No full textProton-bound [M⋅H⋅G]+ diastereomeric complexes between some chiral aromatic amino acids or dipeptides (G) and a chiral multifunctional macrocyclic receptor (M=Chirabite-A) undergo, in the gas phase, highly selective substitution and addition reactions by amines, such as 2-aminobutane and piperidine. All the [M⋅H⋅G]+ complexes follow time-dependent monoexponential decays. In some cases, the kinetic curves exhibit a plateau revealing the presence of unreactive [M⋅H⋅G]+ structures. In them, the amino acid is accommodated in the macrocycle cavity in the zwitterionic form by sharing its acidic hydrogen atoms with the pyridine nitrogen atoms of the host. The same interactions are structurally inaccessible to G=dipeptides or monofunctional amines, which then can be readily released from [M⋅H⋅G]+. When the amino acid interacts with the amidocarbonyl oxygen atoms pointing outside the macrocycle cavity, it saves the canonical structure and can be readily displaced by the amine. The Chirabite-A may act as an efficient template for aromatic amino acids by releasing them or not depending upon the amino acid configuration and the basicity of the amine. These unique properties confer to the gas-phase diastereomeric [M⋅H⋅G]+ complexes the features of multi-input multi-output chemo-“logic gates”
Production of recombinant EMA-1 protein and its application for the diagnosis of Theileria equi using an enzyme immuno assay in horses from São Paulo State, Brazil Produção da proteína recombinante EMA-1 e sua aplicação para o diagnóstico baseadono imuno ensaio enzimático de Theileria equi em equinos do Estado de São Paulo, Brasil
Get PDFThe erythrocytic-stage surface protein, Equi Merozoite Antigen 1 (EMA-1), is a major candidate for the development of a diagnostic antigen for equine piroplasmosis. In order to establish an effective diagnostic method for practical use, the gene encoding the entire EMA-1 of Theileria equi Jaboticabal strain was cloned and expressed in Escherichia coli as a histidine-tagged protein (His6-EMA1). The expressed EMA-1 reacted with specific antibodies in Western blot and had an apparent molecular mass of 34 kDa which was largely consistent with its theoretical value. The nucleotide sequence of the EMA-1 gene of Jaboticabal strain was comparatively analyzed with other published sequences. The results indicated a high degree of homology with EMA-1 genes of all other strains isolated from various countries. The recombinant purified His6-EMA1 protein was tested in an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies anti-T. equi in horses. The ELISA clearly differentiated T. equi-infected from Babesia caballi-infected horse sera or normal horse sera. Field serum samples collected from horses in the State of São Paulo, Southeastern Brazil, were examined for the diagnosis of T. equi infection by ELISA. Of 170 samples analyzed, 95.88% (163/170) were positive for T. equi infection. These results suggest that the His6-EMA1 protein expressed in E. coli could be a reliable immunodiagnostic antigen for ELISA test and that T. equi infection is a serious concern in the State of São Paulo, Brazil.A proteína de superfície eritrocitária, Antígeno 1 do Merozoíta de Theileria equi (EMA-1), é um potencial candidato para o desenvolvimento de antígenos de valor diagnóstico para a piroplasmose equina. Com o objetivo de estabelecer um método de diagnóstico efetivo e prático, o gene EMA-1 da amostra Jaboticabal - SP de T. equi foi clonado e expresso em Escherichia coli contendo uma cauda de poli-histidina (His6-EMA1). O EMA-1 expresso reagiu com anticorpos específicos no Western blot e apresentou peso molecular aparente de 34 kDa, sendo altamente consistente com seu valor teórico. A sequência nucleotídica do gene EMA-1 da amostra Jaboticabal foi analisado comparativamente com outras sequências públicas, e os resultados indicam elevado grau de homologia com amostras de diversos países. A proteína recombinante purificada His6-EMA1 foi testada no ensaio imunoenzimático (ELISA) para a detecção de anticorpos anti-T. equi em equinos. O teste de ELISA diferenciou-se claramente entre soros de equinos infectados por T. equi, soros de animais infectados por Babesia caballi e soro normal de equino. Amostras de soros coletadas de equinos do Estado de São Paulo, sudeste do Brasil, foram examinadas para o diagnóstico da infecção por T. equi pelo ELISA. Das 170 amostras analisadas, 95,88% (163/170) foram positivas para T. equi. Os resultados sugerem que a proteína His6-EMA1 expressa em E. coli pode ser um antígeno confiável para diagnóstico imunológico pelo teste de ELISA, e que T. equi merece grande atenção no Estado de São Paulo
Comparison of a tissue transglutaminase ELISA with the endomysiumantibody test in the diagnosis of gluten-sensitive enteropathy
No full textBackground: Tissue transglutaminase (tTG) has recently been found to be the major if not the only autoantigen of gluten-sensitive enteropathy (GSE). Objectives: To further determine the significance of this finding for diagnostic (screening) and follow-up purposes, we performed tTG-based ELISAs, and compared the results to the endomysium antibody test (EMA). Patients: We examined 120 serum samples from patients with celiac disease (CD) including 72 on a gluten-free diet (GFD) and eleven on a gluten challenge, 47 with dermatitis herpetiformis (DH) including 16 on a GFD and one on a gluten challenge, 96 with non-CD gastrointestinal diseases, and 117 with others; i.e. 380 serum samples altogether. Follow-up sera from 13 patients were included. Methods: Results of an ELISA with guinea pig liver tTG were compared with the EMA test using mon key esophagus. Inhibition of endomysial staining was performed with sera positive on the EMA test but negative with the guinea pig tTG ELISA. Results: The specificity and sensitivity of the tTG ELISA are high (98.6% and 92.5%). The serum IgA antibody titers against tTG decrease after introduction of a GFD. In one case, endomysial staining could not be inhibited. Conclusions: Our results show that the guinea pig tTG ELISA is suitable for use as a simple diagnostic, screening and follow-up method for GSE. Further studies are necessary to identify possible additional minor antigens in GSE
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