991 resultados para IgG-ELISA


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El volumen que reseñamos constituye las ACTAS de las XXIII Jornadas Nacionales de Literatura Francesa y Francófona que se llevaron a cabo en Mendoza, en la sede de la Facultad de Filosofía y Letras de la U.N.Cuyo, los días 27, 28 y 29 de mayo de 2010.

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Fil: Recalde, Iciar. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

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Así como la Historia reconoce a Entre Ríos como cuna de la colonización, es también en esta provincia donde desde el comienzo del siglo XX se desarrolla el cooperativismo agrario que presta importantes servicios al asociado en materia de abastecimiento, comercialización y transformación. Prestación que se traduce en un uso más racional de la tierra, un mayor volumen de negocios, el mejoramiento en la calidad del producto, la utilización eficiente del capital, el aumento de la demanda por la ampliación de los mercados y la introducción de servicios que cada agricultor por si sólo no podría alcanzar. El presente artículo se propone analizar la trayectoria de una cooperativa arrocera -fundada en la década de 1970- ubicada en la localidad entrerriana de Villa Elisa que en mayor o menor media ha ido cumpliendo con esas prestaciones y que hoy se posiciona como el tercer exportador nacional de arroz y el primero de gestión cooperativa. Más allá de las cuestiones económicas, se prestará especial atención a la articulación interinstitucional de la empresa y a los cambios introducidos a nivel organizacional

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Fil: Recalde, Iciar. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

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Así como la Historia reconoce a Entre Ríos como cuna de la colonización, es también en esta provincia donde desde el comienzo del siglo XX se desarrolla el cooperativismo agrario que presta importantes servicios al asociado en materia de abastecimiento, comercialización y transformación. Prestación que se traduce en un uso más racional de la tierra, un mayor volumen de negocios, el mejoramiento en la calidad del producto, la utilización eficiente del capital, el aumento de la demanda por la ampliación de los mercados y la introducción de servicios que cada agricultor por si sólo no podría alcanzar. El presente artículo se propone analizar la trayectoria de una cooperativa arrocera -fundada en la década de 1970- ubicada en la localidad entrerriana de Villa Elisa que en mayor o menor media ha ido cumpliendo con esas prestaciones y que hoy se posiciona como el tercer exportador nacional de arroz y el primero de gestión cooperativa. Más allá de las cuestiones económicas, se prestará especial atención a la articulación interinstitucional de la empresa y a los cambios introducidos a nivel organizacional

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Así como la Historia reconoce a Entre Ríos como cuna de la colonización, es también en esta provincia donde desde el comienzo del siglo XX se desarrolla el cooperativismo agrario que presta importantes servicios al asociado en materia de abastecimiento, comercialización y transformación. Prestación que se traduce en un uso más racional de la tierra, un mayor volumen de negocios, el mejoramiento en la calidad del producto, la utilización eficiente del capital, el aumento de la demanda por la ampliación de los mercados y la introducción de servicios que cada agricultor por si sólo no podría alcanzar. El presente artículo se propone analizar la trayectoria de una cooperativa arrocera -fundada en la década de 1970- ubicada en la localidad entrerriana de Villa Elisa que en mayor o menor media ha ido cumpliendo con esas prestaciones y que hoy se posiciona como el tercer exportador nacional de arroz y el primero de gestión cooperativa. Más allá de las cuestiones económicas, se prestará especial atención a la articulación interinstitucional de la empresa y a los cambios introducidos a nivel organizacional

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Background Obeche wood dust is a known cause of occupational asthma where an IgE-mediated mechanism has been demonstrated. Objective To characterize the allergenic profile of obeche wood dust and evaluate the reactivity of the proteins by in vitro, ex vivo and in vivo assays in carpenters with confirmed rhinitis and/or asthma Materials and methods An in-house obeche extract was obtained, and two IgE binding bands were purified (24 and 12 kDa) and sequenced by N-terminal identity. Specific IgE and IgG, basophil activation tests and skin prick tests (SPTs) were performed with whole extract and purified proteins. CCD binding was analyzed by ELISA inhibition studies. Results Sixty-two subjects participated: 12 with confirmed occupational asthma/rhinitis (ORA+), 40 asymptomatic exposed (ORA−), and 10 controls. Of the confirmed subjects, 83% had a positive SPT to obeche. There was a 100% recognition by ELISA in symptomatic subjects vs. 30% and 10% in asymptomatic exposed subjects and controls respectively (p<0.05). Two new proteins were purified, a 24 kDa protein identified as a putative thaumatin-like protein and a 12 kDa gamma-expansin. Both showed allergenic activity in vitro, with the putative thaumatin being the most active, with 92% recognition by ELISA and 100% by basophil activation test in ORA+ subjects. Cross-reactivity due to CCD was ruled out in 82% of cases. Conclusions Two proteins of obeche wood were identified and were recognized by a high percentage of symptomatic subjects and by a small proportion of asymptomatic exposed subjects. Further studies are required to evaluate cross reactivity with other plant allergens.

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The NOD (nonobese diabetic) mouse has been studied as an animal model for autoimmune insulin-dependent diabetes and Sjögren’s syndrome. NOD.Igμnull mice, which lack functional B lymphocytes, develop progressive histopathologic lesions of the submandibular and lachrymal glands similar to NOD mice, but in the absence of autoimmune insulitis and diabetes. Despite the focal appearance of T cells in salivary and lachrymal tissues, NOD.Igμnull mice fail to lose secretory function as determined by stimulation of the muscarinic/cholinergic receptor by the agonist pilocarpine, suggesting a role for B cell autoantibodies in mediating exocrine dryness. Infusion of purified serum IgG or F(ab′)2 fragments from parental NOD mice or human primary Sjögren’s syndrome patients, but not serum IgG from healthy controls, alters stimulated saliva production, an observation consistent with antibody binding to neural receptors. Furthermore, human patient IgG fractions competitively inhibited the binding of the muscarinic receptor agonist, [3H]quinuclidinyl benzilate, to salivary gland membranes. This autoantibody activity is lost after preadsorption with intact salivary cells. These findings indicate that autoantibodies play an important part in the functional impairment of secretory processes seen in connection with the autoimmune exocrinopathy of Sjögren’s syndrome.

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Rearrangement of chromosomal bands 1q21–23 is one of the most frequent chromosomal aberrations observed in hematological malignancy. The genes affected by these rearrangements remain poorly characterized. Typically, 1q21–23 rearrangements arise during tumor evolution and accompany disease-specific chromosomal rearrangements such as t(14;18) (BCL2) and t(8;14) (MYC), where they are thus thought to play an important role in tumor progression. The pathogenetic basis of this 1q21–23-associated disease progression is currently unknown. In this setting, we surveyed our series of follicular lymphoma for evidence of recurring 1q21–23 breaks and identified three cases in which a t(14;18)(q32;q21) was accompanied by a novel balanced t(1;22)(q22;q11). Molecular cloning of the t(1;22) in a cell line (B593) derived from one of these cases and detailed fluorescent in situ hybridization mapping in the two remaining cases identified the FCGR2B gene, which encodes the immunoreceptor tyrosine-based inhibition motif-bearing IgG Fc receptor, FcγRIIB, as the target gene of the t(1;22)(q22;q11). We demonstrate deregulation of FCGR2B leading to hyperexpression of FcγRIIb2 as the principal consequence of the t(1;22). This is evidence that IgG Fc receptors can be targets for deregulation through chromosomal translocation in lymphoma. It suggests that dysregulation of FCGR2B may play a role in tumor progression in follicular lymphoma.

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IgG antibodies can suppress more than 99% of the antibody response against the antigen to which they bind. This is used clinically to prevent rhesus-negative (Rh−) women from becoming immunized against Rh+ erythrocytes from their fetuses. The suppressive mechanism is poorly understood, but it has been proposed that IgG/erythrocyte complexes bind to the inhibitory Fc receptor for IgG (FcγRIIB) on the B cell surface, thereby triggering negative signals that turn off the B cell. We show that IgG induces the same degree of suppression of the response to sheep erythrocytes in animals lacking the known IgG-binding receptors FcγRIIB, FcγRI + III, FcγRI + IIB + III, and FcRn (the neonatal Fc receptor) as in wild-type animals. Reinvestigation of the ability of F(ab′)2 fragments to suppress antibody responses demonstrated that they were nearly as efficient as intact IgG. In addition, monoclonal IgE also was shown to be suppressive. These findings suggest that IgG inhibits antibody responses through Fc-independent mechanisms, most likely by masking of antigenic epitopes, thereby preventing B cells from binding and responding to antigen. In agreement with this, we show that T cell priming is not abolished by passively administered IgG. The results have implications for the understanding of in vivo regulation of antibody responses and Rh prophylaxis.

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The recent interest in using Buckminsterfullerene (fullerene) derivatives in biological systems raises the possibility of their assay by immunological procedures. This, in turn, leads to the question of the ability of these unprecedented polygonal structures, made up solely of carbon atoms, to induce the production of specific antibodies. Immunization of mice with a C60 fullerene derivative conjugated to bovine thyroglobulin yielded a population of fullerene-specific antibodies of the IgG isotype, showing that the immune repertoire was diverse enough to recognize and process fullerenes as protein conjugates. The population of antibodies included a subpopulation that crossreacted with a C70 fullerene as determined by immune precipitation and ELISA procedures. These assays were made possible by the synthesis of water-soluble fullerene derivatives, including bovine and rabbit serum albumin conjugates and derivatives of trilysine and pentalysine, all of which were characterized as to the extent of substitution and their UV-Vis spectra. Possible interactions of fullerenes with the combining sites of IgG are discussed based on the physical chemistry of fullerenes and previously described protein-fullerene interactions. They remain to be confirmed by the isolation of mAbs for x-ray crystallographic studies.

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In most vertebrate embryos and neonates studied to date unique antigen receptors (antibodies and T cell receptors) are expressed that possess a limited immune repertoire. We have isolated a subclass of IgM, IgM1gj, from the nurse shark Ginglymostoma cirratum that is preferentially expressed in neonates. The variable (V) region gene encoding the heavy (H) chain underwent V-D-J rearrangement in germ cells (“germline-joined”). Such H chain V genes were discovered over 10 years ago in sharks but until now were not shown to be expressed at appreciable levels; we find expression of H1gj in primary and secondary lymphoid tissues early in life, but in adults only in primary lymphoid tissue, which is identified in this work as the epigonal organ. H1gj chain associates covalently with light (L) chains and is most similar in sequence to IgM H chains, but like mammalian IgG has three rather than the four IgM constant domains; deletion of the ancestral IgM C2 domain thus defines both IgG and IgM1gj. Because sharks are the members of the oldest vertebrate class known to possess antibodies, unique or specialized antibodies expressed early in ontogeny in sharks and other vertebrates were likely present at the inception of the adaptive immune system.