RESUMEN
Synthesis and physico-chemical properties of 3-benzyl-5-(4-fluoro-benzylidene)-1-methyl-2-thioxo-imidazolidin-4-ones, 5-benzylidene-3-(4-nitro-benzyl)-2-thioxo-imidazolidin-4-ones and 4-acridin-9-ylmethylene-1-benzyl-5-thioxo-imidazolidin-2-ones compounds are described. These thioxo-imidazolidine derivatives were prepared by alkylation and condensation with 4-fluoro-benzaldehyde or nucleophilic Michael addition with cyanoacrylates. The schistosomicidal activity of 3-benzyl-5-(4-fluoro-benzylidene)-1-methyl-2-thioxo-imidazolidin-4-one compounds was evaluated.
Asunto(s)
Imidazolidinas/síntesis química , Imidazolidinas/farmacología , Esquistosomicidas/síntesis química , Esquistosomicidas/farmacología , Animales , Cristalografía por Rayos X , Femenino , Indicadores y Reactivos , Espectroscopía de Resonancia Magnética , Masculino , Ratones , Schistosoma mansoni/efectos de los fármacos , Esquistosomicidas/toxicidadRESUMEN
One the most important aspects of a biosensor is related to immobilization and maintenance of specific reference compounds on sensing surfaces. A method for the immobilization of polysaccharides to a silicon oxide surface intended for Surface Acoustical Waves (SAW) sensors is described. Silicon oxide is a hydrophobic inorganic support used for the fabrication of many electronic devices. The pneumococcal polysaccharide (PPS) vaccine is immobilized via Protein A after pre-treatment of the surface with hydrochloric acid. The effects of non-specific binding are discussed. The results indicate that the immobilization of PPS via Protein A increases the sensitivity of detecting Streptococcus pneumoniae antibodies in human sera and offers greater reproducibility of response compared with ELISA methods. The principles of this technique are simple and are applicable to the immobilization of many capsular polysaccharides.
Asunto(s)
Técnicas Biosensibles/métodos , Acústica , Anticuerpos Antibacterianos/sangre , Técnicas Biosensibles/estadística & datos numéricos , Ensayo de Inmunoadsorción Enzimática/estadística & datos numéricos , Humanos , Vacunas Neumococicas , Polisacáridos Bacterianos , Sensibilidad y Especificidad , Dióxido de Silicio , Streptococcus pneumoniae/inmunologíaRESUMEN
Soluble adult Schistosoma mansoni antigen preparation (SWAP) was covalently fixed onto polyvinyl alcohol-glutaraldehyde discs and an enzyme linked-immunosorbent assay (ELISA) was set up. The best conditions for the assay were established and it was found that small amount of antigen such as 1.5 micrograms was required. A comparison between this procedure and the conventional ELISA was proceeded. A reliable method of antigen immobilization was achieved and the low prices of the employed reagents are economically attractive.
Asunto(s)
Glutaral , Alcohol Polivinílico , Esquistosomiasis/diagnóstico , Animales , Ensayo de Inmunoadsorción Enzimática , Humanos , ConejosRESUMEN
Discs of polyvinyl alcohol cross-linked with glutaraldehyde were synthesized under acid catalysis (H2SO4). Then, the antigen F1 purified from Yersinia pestis was covalently linked to this modified polymer. Afterwards, an enzyme-linked immunosorbent assay (ELISA) was established for the diagnosis of plague in rabbit and human. The best conditions for the method were achieved by using 1.3 micrograms of F1 prepared in 0.067 M phosphate buffer, pH 7.2, containing 1 M NaCl (PBS); anti-IgG peroxidase conjugate diluted 6,000 times and as a blocking agent 3% w/v skim milk in PBS. The titration of positive rabbit serum according to this procedure detected antibody concentrations up to 1:12,800 times. The present method, the conventional ELISA and passive haemagglutination assay are compared.
Asunto(s)
Ensayo de Inmunoadsorción Enzimática/métodos , Glutaral , Peste/diagnóstico , Alcohol Polivinílico , Animales , Humanos , ConejosRESUMEN
The seroprevalence of antibodies against human T-cell leukemia virus was determined by ELISA in 68 patients with filarial infestation living in an endemic area. The total seropositivity was 2.9% and the HTLV-1-positive cases were detected in 2 microfilaremic patients 12 and 40 years old. This value is very close to that obtained for healthy individuals in the same region and age groups. This result suggests that there is no relationship between filariasis and HTLV-1 infection as previously proposed.
Asunto(s)
Filariasis/complicaciones , Anticuerpos Anti-HTLV-I/análisis , Infecciones por HTLV-I/etiología , Adolescente , Adulto , Brasil , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática , Filariasis/inmunología , Filariasis/virología , Infecciones por HTLV-I/inmunología , Humanos , Lactante , Recién Nacido , Pruebas SerológicasRESUMEN
Ferromagnetic dacron is proposed as an alternative solid-phase for magnetic enzyme immunoassays. Human serum albumin (HSA) was covalently immobilized onto ferromagnetic dacron and an enzyme immunoassay was developed using anti-HSA rabbit sera. Peroxidase, o-phenylenediamine (OPD) and hydrogen peroxide were used as the enzymatic label and substrates, respectively. Best results were observed when particles of 63-100 microns (diameter) and 10 micrograms of immobilized antigen were used. Positive reactions were detected until dilutions of 1:51200 of immune sera. Its reproducibility was similar to standard ELISA. Disruption of the immunocomplexes formed and recuperation of the immobilized antigen in other immunoassays also proved to be reliable.