Search results for "Pten"
showing 10 items of 211 documents
Hapten Design and Antibody Generation for Immunoanalysis of Spirotetramat and Spirotetramat-enol
2018
Spirotetramat - a tetramic acid insecticide - is rapidly metabolized or degraded to give spirotetramat-enol; so, common residue definitions include the sum of both compounds. In the present study, two spirotetramat-functionalized derivatives (haptens) have been designed to generate immunoreagents to these molecules for rapid immunochemical analysis. Haptens have been synthesized with alternative linker tethering sites and, for the first time, high-affinity antibodies have been generated with different specificities to these active principles. Two sensitive assays have been developed using the same antibody in different formats, and by using linker-site heterologous haptens, the selectivity …
Rationally designed haptens for highly sensitive monoclonal antibody-based immunoanalysis of fenhexamid.
2018
Immunochemical methods have been consolidated during the last few years as complementary analytical strategies for chemical contaminant and residue determination. However, generation of suitable immunoreagents for small organic molecules demands adequate hapten design. In this study, fenhexamid was considered as a model compound and novel haptens were designed and synthesized in order to evaluate the influence of the linker tethering site on antibody binding properties and immunoassay parameters. Haptens were conceived with the spacer arm at different positions, while the more antigenic aromatic moiety was kept free. The synthesis of these functionalized compounds was accomplished by total …
Generation of anti-azoxystrobin monoclonal antibodies from regioisomeric haptens functionalized at selected sites and development of indirect competi…
2012
Azoxystrobin is a modern strobilurin fungicide used around the world to combat prime diseases affecting highly valuable crops. Accordingly, residues of this chemical are frequently found in food, even though mostly under maximum tolerated levels. We herein describe the development of an indirect competitive immunoassay for the determination of azoxystrobin residues. A panel of monoclonal antibodies displaying subnanomolar affinity to azoxystrobin was generated using, as immunizing haptens in mice, four functionalized derivatives carrying the same spacer arm located at different rationally chosen positions. This collection of antibodies was thoroughly characterized with homologous and hetero…
Evaluation of the concept of heterology in a monoclonal antibody-based ELISA utilizing direct hapten linkage to polystyrene microtiter plates.
2005
A series of new heterologous haptens has been synthesized and used as coating haptens in an antigen-immobilized immunoassay with a monoclonal antibody against atrazine. Coating was achieved by covalently linking the different haptens to a glutaraldehyde network directly bound to the polystyrene surface of a standard 96-well microtiter plate. With the assay designed in the antigen-immobilized format with direct chemical linkage of the hapten to the solid polystyrene surface well-defined hapten densities were achieved in all experiments. The results of different experiments with different coating haptens were comparable. Using different heterologous haptens it appears that the concept of hete…
Synthesis of azoxystrobin transformation products and selection of monoclonal antibodies for immunoassay development
2012
The use of agrochemicals for crop protection may result in the presence of toxic residues in soils and aquatic environments, besides in foodstuffs. Most often just the parent compound is included in the definition of pesticide residue, even though chemicals resulting from biotransformation and degradation routes might also be of toxicological relevance. Azoxystrobin is a broad-spectrum systemic fungicide widely used worldwide to combat pathogenic fungi affecting plants. We herein report the synthesis and detailed chemical characterization of several of the most relevant metabolites and degradates of azoxystrobin. These compounds were further employed as ligands for screening a collection of…
Cowden's syndrome diagnosed through oral lesions : a case report
2021
Cowden's syndrome (CS), also known as multiple hamartoma syndrome, is a rare autosomal dominant genodermatosis first described in 1963. It has a high penetrance in both sexes and variable phenotypes. Its origin is a PTEN (phosphatase and tensin homologue) gene mutation and affects multiple organs of endodermal, ectodermal, and mesodermal origin, resulting in the development of hamartomatous mucocutaneus lesions and an increased risk for malignancies in breast, thyroid, endometrium, kidney, colon, rectum, among other organs. The diagnosis of CS is based mainly on clinical findings and oral cavity manifestations are frequent, occurring in 80-90% of patients. This include oral and labial papil…
Major histocompatibility complex regulation of cytokine production.
1996
This review describes the phenomenon of the major histocompatibility complex (MHC) control of cytokine production both in experimental animals and in humans. H-2 (mouse MHC) regulates which type of cytokine is selectively produced in response to the hapten trinitrophenyl (TNP). T cells from TNP-immune H-2k mice produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-3, IL-5, tumor necrosis factor-alpha (TNF-alpha), IL-10, and very low levels of IL-4 on reexposure to the specific antigen in vitro. By contrast, T cells from H-2d mice produce IL-3, TNF-alpha, IL-10, and IL-4 but very low levels of IL-2, IL-5 and IFN-gamma. As MHC-congenic matched strains (BALB/k and BALB/c) are used, th…
Capacidad predictiva y pronóstica de factores moleculares en cáncer de mama HER2 positivo tratado con quimioterapia neoadyuvante basada en antracicli…
2017
El tratamiento neoadyuvante del cáncer de mama (CM) permite estudiar marcadores subrogados que puedan predecir respuesta clínica y supervivencia. La respuesta completa patológica (RCp) definida como la ausencia de tumor infiltrante en la mama y axila en la pieza quirúrgica se asocia a mejor supervivencia. En los tumores HER2 positivo el tratamiento de elección es la combinación de quimioterapia, antraciclinas y taxanos son los esquemas con mayor evidencia, con terapia anti-HER2 (trastuzumab (TTZ)) alcanzando tasas de RCp del 30-60%. No disponemos de factores predictivos que identifiquen qué subgrupo obtendrá mayores tasas de RCp . Existe evidencia que los tumores con receptores hormonales (…
A novel microtubule de-stabilizing complementarity-determining region C36L1 peptide displays antitumor activity against melanoma in vitro and in vivo
2015
AbstractShort peptide sequences from complementarity-determining regions (CDRs) of different immunoglobulins may exert anti-infective, immunomodulatory and antitumor activities regardless of the specificity of the original monoclonal antibody (mAb). In this sense, they resemble early molecules of innate immunity. C36L1 was identified as a bioactive light-chain CDR1 peptide by screening 19 conserved CDR sequences targeting murine B16F10-Nex2 melanoma. The 17-amino acid peptide is readily taken up by melanoma cells and acts on microtubules causing depolymerization, stress of the endoplasmic reticulum and intrinsic apoptosis. At low concentrations, C36L1 inhibited migration, invasion and proli…
Septentrionalidad y medievalidad en el paradigma arteaguiano de lo maravilloso. Una lectura de las riflessioni de Esteban de Arteaga en Le Rivoluzion…
2014
“Septentrionalidad y medievalidad en el paradigma arteaguiano de lo maravilloso. Una lectura de las “riflessioni” de Esteban de Arteaga en Le Rivoluzioni del Teatro Musicale Italiano”, es un estudio de carácter multidisciplinar sobre un texto en muchos aspectos singular y hasta ahora prácticamente no abordado. Las riflessioni son una indagación sobre los fundamentos antropológicos de un determinado constructo de lo maravilloso. Uno de los primeros intentos por analizar y comprender esa fenomenología de la fascinación. El primero, sin duda, en poner el acento en los elementos de septentrionalidad y medievalidad. Y todo ello en el marco de lo que quiere ser un estudio sobre el devenir del tea…