Navegando por Palavras-chave "Radioimunoensaio"
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- ItemAcesso aberto (Open Access)Aplicação da cromatografia a líquido em substituição à técnica de radioimunoensaio como auxílio diagnóstico visando ao gerenciamento de resíduos de serviço da saúde em laboratório de pesquisa(Sociedade Brasileira de Endocrinologia e Metabologia, 2008-10-01) Ribeiro Neto, Luciane M. [UNIFESP]; Sugawara, Eduardo K. [UNIFESP]; Verreschi, Ieda Therezinha do Nascimento [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Designing a Health Care Service Waste Management Plan, according to the RDC 306 rules, is a responsibility of all those who produce such waste. Since radioimmunoassay (RIA) is one of the most employed techniques, we studied the impact of replacing this technique by liquid chromatography (HPLC) with regard to the reduction of the radioactive residues routinely produced by the UNIFESP steroid laboratory. The residues produced by the determination of serum cortisol and 17 α-hydroxyprogesterone were classified, and those belonging to groups B and C were evaluated. We observed that, when RIA is used, chemical residues (group B) and radioactive waste (group C) are produced, whereas HPLC generates only chemical residues. Adequation of these techniques showed to be advantageous, by significantly reducing the time of analysis and mainly by eliminating and/or reducing the generation of radioactive waste, encouraging its application to other methodologies, as well as its adoption by other research units.
- ItemAcesso aberto (Open Access)Desenvolvimento de um radioimunoensaio de dexametasona no soro como subsídio para o diagnóstico da síndrome de Cushing(Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia, 2011-10-01) Hayashi, Lilian Fukusima [UNIFESP]; Noguti, Keiko O; Nakamura, Odete H; Kater, Claudio Elias [UNIFESP]; Vieira, José Gilberto Henriques [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)INTRODUCTION: The 1 mg dexamethasone suppression test (DxST) is widely used to screen Cushing's syndrome (CS) due to its high diagnostic accuracy. CS is an endocrine-metabolic disorder caused by hypercorticism, which is characterized by the absence of cortisol suppression in DxST. OBJECTIVE: To develop a radioimmunoassay (RIA) for the measurement of serum dexamethasone (Dx) to complement DxST. METHODS: Three rabbits were inoculated with dexamethasone-21-hemisuccinate-BSA in order to choose the best antibody. Serum Dx RIA was performed according to RE 899/2003 (Agência Nacional de Vigilância Sanitária [ANVISA]) regulations. Serum samples from 96 volunteers from Universidade Federal de São Paulo (UNIFESP) and Santa Casa de Misericórdia de São Paulo were analyzed, 67 of which were submitted to DxST and 29 were not. There were 12 patients with CS. RESULTS: The Dx antibody chosen showed good specificity. Intra- and interassay CV were < 20% with 93.8% accuracy and the lowest detection limit was 19.5 ng/dl. Serum Dx concentration was similar among both volunteers and CS patients (absence of cortisol suppression): 205 to 703 ng/dl and 174 to 661 ng/dl (95% CI), respectively. Values were undetectable among those that were not submitted to the test. Discussion: The anti-Dx antibody shows high specificity and reliability to quantify serum Dx in DxST. The Dx RIA presented reproducibility and reliability in the determination of serum Dx levels during DxST. CONCLUSION: The current RIA for serum Dx is accurate and reliable, which permits to establish a reference value range to substantiate DxST interpretation.
- ItemAcesso aberto (Open Access)Desenvolvimento de um radioimunoensaio para 21-deoxicortisol sérico e sua potencial aplicação no diagnóstico da hiperplasia adrenal congênita(Sociedade Brasileira de Endocrinologia e Metabologia, 2003-04-01) Tonetto-Fernandes, Vânia [UNIFESP]; Ribeiro-Neto, Luciane M. [UNIFESP]; Verreschi, Ieda Therezinha do Nascimento [UNIFESP]; Fiet, Jean; Vieira, José Gilberto H. [UNIFESP]; Kater, Claudio Elias [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Hospital Infantil Darcy Vargas Serviço de Endocrinologia Pediátrica; Hôpital Saint Louis Service de Biologie HormonaleSerum 21-deoxycortisol (21DF) has been considered a useful hormonal marker for the diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD). Although several radioimmunoassay (RIA) methods for 21DF have been reported, none are commercially available. We developed a RIA adapted for 21DF determination, preceded by ether-extraction and liquid chromatographic separation (HPLC) of samples. The assay was employed to evaluate children (15F/10M) with the classic form of 21OHD and a control group (5F/8M). The antibody obtained, in addition to efficient HPLC separation, permitted tritiated cortisol instead of 21DF to be used, since labeled ³H-21DF is expensive and difficult to obtain. Serum cortisol levels were reduced in patients with 21OHD (48h following therapy withdrawal) as compared to controls (2.1±2.1 vs. 16.2±7.0mug/dl), whereas serum levels of 21DF were significantly elevated (1,359±853ng/dl, ranging from 434 to 3,079) in the former, but consistently below the sensitivity limit of the assay (156ng/dl) in the latter group. The reported method, although devoid of sensitivity for its application in normal subjects, permits 21DF to be quantified in patients with 21OHD, with adequate sensitivity and specificity to diagnose and follow patients with this condition.
- ItemSomente MetadadadosDeterminação de IGF-I por radioimunoensaio: padronização de valores normais e aplicação clínica(Universidade Federal de São Paulo (UNIFESP), 1992) Portes, Evandro de Souza [UNIFESP]; Chacra, Antonio Roberto [UNIFESP]
- ItemSomente MetadadadosDosagem do sulfato de dehidroepiandrosterona sérico por radioimunoensaio: metodologia e aplicações clinicas(Universidade Federal de São Paulo (UNIFESP), 1979) Furlanetto, Reinaldo Perrone [UNIFESP]; Vieira, Jose Gilberto Henriques [UNIFESP]
- ItemSomente MetadadadosEmprego da cromatografia a liquido (HPLC) na determinacao de cortisol em diferentes matrizes biologicas(Universidade Federal de São Paulo (UNIFESP), 2008) Sugawara, Eduardo Kinio [UNIFESP]
- ItemAcesso aberto (Open Access)Emprego da cromatografia líquida de alta eficiência na determinação de cortisol sérico em substituição à técnica de radioimunoensaio(Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia, 2008-10-01) Sugawara, Eduardo Kinio [UNIFESP]; Ribeiro Neto, Luciane Maria [UNIFESP]; Oliveira, Kelly Cristina de [UNIFESP]; Verreschi, Ieda Therezinha do Nascimento [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)BACKGROUND: The quantification of cortisol in different organic fluids has not only been applied to different human nosological conditions as a diagnostic aid but it has also been used in clinical research. In clinical application, cortisol is routinely measured by radioimmunoassay (RIA). In the determination of free urinary cortisol this technique has been replaced by the high-performance liquid chromatography mainly in the diagnosis of Cushing syndrome. As to serum cortisol determination, there is no evidence of the application of liquid chromatography as a substitute for other analytical techniques. OBJECTIVE: The development of an analytical methodology using reversed-phase high-performance liquid chromatography (RP-HPLC) to determine serum cortisol levels as a substitute for RIA in order to reduce radioactive waste. MATERIAL AND METHODS: Cortisol was directly quantified by RP-HPLC in previously ether-extracted serum samples. Triamcinolone acetonide was used as internal standard (IS). The chromatographic separation was developed in a BDS-Hypersil-C18® column (125 x 4 mm, 5 µm) using water-acetonitrile (72:28; v/v) as mobile phase at 1 ml/min and steroid peaks were measured at 243 nm. RESULTS: Cortisol and IS presented retention time of 3.4 and 7.1 min, respectively. The precision was less than 10% and accuracy was less than 4%. DISCUSSION: The method was effective and efficient, with good sensitivity and linearity in the concentration range of 2.5 to 60.0 µµg/dl. CONCLUSION: The present methodology substitutes RIA at clinical application.
- ItemAcesso aberto (Open Access)Evidenciação de antígeno da hepatite B (HBsAg) em manchas obtidas de exemplares de Triatominae: nota prévia(Faculdade de Saúde Pública da Universidade de São Paulo, 1976-09-01) Candeias, J. A. N.; Forattini, Oswaldo Paulo; Vieira, J. G. [UNIFESP]; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)A total of 890 impressions on filter paper identified as containing human blood, were examined for the presence of hepatitis B antigen (HBsAg), using the Hepanosticon haemagglutination and radioimmunoassay techniques. The samples examined belong to the Panstrongylus, Rhodnius and Triatoma genres. The Hepanosticon haemagglutination technique showed that 7 impressions, after elution, were presumably positive for HBsAg, but by radioimmunoassay, this antigen could only be detected in 1. The positive sample was obtained from a specimen of Triatoma sordida (fifth instar nymph).
- ItemAcesso aberto (Open Access)Evolution of PTH assays(Sociedade Brasileira de Endocrinologia e Metabologia, 2006-08-01) Vieira, Jose Gilberto Henriques [UNIFESP]; Kunii, Ilda Sizue [UNIFESP]; Nishida, Sonia Kiyomi; Laboratorio Fleury; Universidade Federal de São Paulo (UNIFESP)PTH metabolism is complex and the circulating forms include the intact 1-84 molecule as well as several carboxyl-terminal fragments. The first generation of PTH assays included several types of competitive assays, with specificities that spanned carboxyl, mid-region and amino-terminal portions of the molecule. The limitations of these assays and the methodological evolution led to the description of 2nd generation non-competitive immunometric assays for PTH in the late 80's, based on the recognition of the PTH molecule by two different antibodies, one directed against de amino-terminal and other against the carboxyl-terminal segments. The observation that in some circumstances long carboxyl-terminal segments were also measured by 2nd generation assays led to the development of 3rd generation assays based on amino-terminal specific antibodies that are specific for the first amino acids, measuring only the molecular forms that activate PTH1R. The practical and cost-benefit advantages of these assays are still debatable. The recent observation that carboxyl-terminal fragments of PTH have biological activity via a distinct receptor than PTH1R, points to the future need of more than one assay in order to evaluate parathyroid hormone function.
- ItemSomente MetadadadosGh-Rie, Gh-Iema, IgF-I-Rie: aspectos metodológicos e aplicaçöes no diagnóstico, segmento e definiçäo dos critérios de cura da acromegalia(Universidade Federal de São Paulo (UNIFESP), 1993) Czepielewski, Mauro A [UNIFESP]; Vieira, José Gilberto Henriques [UNIFESP]
- ItemSomente MetadadadosRadioimunoensaio da progesterona no fluido salivar: desenvolvimento da metodologia e sua correlação com a determinação sérica(Universidade Federal de São Paulo (UNIFESP), 1986) Hannuch, Suzanmeire Negro Minatti [UNIFESP]; Zukerman, Eliova [UNIFESP]
- ItemSomente MetadadadosRadioimunoensaio do cortisol serico, metodologia e aplicacoes clinicas(Universidade Federal de São Paulo (UNIFESP), 1977) Vieira, Jose Gilberto Henrique [UNIFESP]
- ItemSomente MetadadadosRadioimunoensaio do paratormonio humano (hPTH) no soro: desenvolvimento metodologico e implicacoes diagnosticas(Universidade Federal de São Paulo (UNIFESP), 1984) Vieira, Jose Gilberto Henriques [UNIFESP]