Lanthanide-based time-resolved luminescence immunoassays

The sensitive and specific detection of analytes such as proteins in biological samples is critical for a variety of applications, for example disease diagnosis. In immunoassays a signal in response to the concentration of analyte present is generated by use of antibodies labeled with radioisotopes, luminophores, or enzymes. All immunoassays suffer to some extent from the problem of the background signal observed in the absence of analyte, which limits the sensitivity and dynamic range that can be achieved. This is especially the case for homogeneous immunoassays and surface measurements on tissue sections and membranes, which typically have a high background because of sample autofluorescence. One way of minimizing background in immunoassays involves the use of lanthanide chelate labels. Luminescent lanthanide complexes have exceedingly long-lived luminescence in comparison with conventional fluorophores, enabling the short-lived background interferences to be removed via time-gated acquisition and delivering greater assay sensitivity and a broader dynamic range. This review highlights the potential of using lanthanide luminescence to design sensitive and specific immunoassays. Techniques for labeling biomolecules with lanthanide chelate tags are discussed, with aspects of chelate design. Microtitre plate-based heterogeneous and homogeneous assays are reviewed and compared in terms of sensitivity, dynamic range, and convenience. The great potential of surface-based time-resolved imaging techniques for biomolecules on gels, membranes, and tissue sections using lanthanide tracers in proteomics applications is also emphasized

Epidemiology of neurocysticercosis in Brazil Epidemiologia da neurocisticercose no Brasil

A revision of literature was done with the objective of tracing an epidemiologic profile of neurocysticercosis (NCC) in Brazil. The prevalence was 0.12-9% in autopsies. The frequency was 0.03-7.5% in clinical series and 0.68-5.2% in seroepidemiological studies. The disease corresponds to 0.08-2.5% of admissions to general hospitals. Patient origin was rural in 30-63% of cases. The most involved age range (64-100%) was 11 to 60 years, with a predominance (22-67%) between 21 and 40 years. The male sex was the most affected (51-80%). In the severe forms there was a predominance of urban origin (53-62%) and of the female sex (53-75%). The period of hospitalization ranges from 1 to 254 days and 33 to 50% of patients suffer 1.7 &plusmn; 1.4 admissions. The clinical picture was variable, with a predominance of epileptic syndrome (22-92%) and intracranial hypertension (19-89%). Psychiatric manifestations were associated in 9-23% of patients. Lethality was 0.29% in terms of all diseases in general and 4.8-25.9% in terms of neurologic diseases. The asymptomatic form was detected in 6% of patients in clinical serie and in 48.5% of case from autopsies. The racemose form and ventricular localization also was observed as asymptomatic form. Among the patients with cutaneous cysticercosis 65% of them showed neurologic manifestations.<br>Realizou-se revisão da literatura com o objetivo de tentar delinear um perfil epidemiológico da neurocisticercose no Brasil. A prevalência em necrópsias variou de 0,12-9%. A freqüência, nas casuísticas clínicas foi de 0,03-7,5% e, nos estudos soroepidemiológicos, de 0,68-5,2%. Compreendeu 0,08-2,5% das internações em hospitais gerais. A procedência foi rural em 30-63% dos doentes. Comprometeu mais (64-100%) na faixa etária dos 11 aos 60 anos, predominantemente (22-67%) entre 21 e 40 anos. O sexo masculino foi mais atingido (51-80%). Nas formas graves, houve predomínio da origem urbana (53-62%) e do sexo feminino (53-75%). O período de internação variou de 1 -254 dias, com 33 a 50% dos doentes necessitando 1.7 &plusmn; 1,4 admissões. Houve variabilidade no quadro clínico, predominando síndrome epiléptica (22-92%) e hipertensão intracraniana (19-89%). A presença de manifestações psiquiátricas foi observada em 9-23% dos doentes. A letalidade, frente as doenças em geral, foi de 0,29% e, entre as doenças neurológicas, de 4,8-25,9%. A forma assintomática foi detectada em 6% dos doentes de casuística clínica e em 48,5% dos casos de necrópsia. A forma racemosa e a localização ventricular também se apresentaram de maneira assintomática. Entre os doentes com cisticercose cutânea, 65% apresentavam manifestações neurológicas