Antígeno recombinante 47kDa de Treponema pallidum: caracterização imunológica e estudo comparativo com o antígeno nativo / Recombinant Treponema pallidum 47 kDa antigen: immunological characterization and comparative study with native antigen

O antígeno recombinante 47 kDa de Treponema palludum foi caracterizado por SDS-PAGE e immunobiotting (IB) com soro de paciente com diagnóstico da sífilis. NO SDS-PAGE o antígeno recombinante apresentou uma banda de 67 kDa. No IB foram reveladas várias bandas de 87 a 33 kDa, sendo mais expressiva a de 67 kDa. Obteve-se um anticorpo monoespecífico (anti-67 kDa do antígeno recombinante), em eluato com tampão glicina, cuja reatividade foi avaliada com o antígeno nativo – Treponema pallidum. Este reagiu somente com a banda 47 kDa do antígeno nativo e com todas as bandas do antígeno recombinante. No ELISA, o antígeno recombinante falhou na detecção de 3 amostras positivas, os quais apresentaram maior reatividade para as frações 17 e/ou 35 kDa, enquanto uma amostra apresentou baixa reatividade com a fração de 47 kDa, no IB com antígeno nativo. Conclui-se que a proteína múltiplas bandas mantêm a especificidade antigênica, sugerindo que podem ser componentes de polímero ou frações de degradação, algumas amostras positivas não apresentam anticorpos contra o epítopo de 47kDa, tornando questionável o uso deste antígeno para o diagnóstico da sífilis.

High effectiveness of aerosolized chick embryo fibroblast measles vaccine in seven-month-old and older infants.

Neither the presence of hypertonic sugar nor the absence of 1% human albumin in the aerosolized chick embryo fibroblast (CEF) measles vaccine was previously found to be responsible for its inadequacy in infants with titers of maternal plaque-neutralizing (PN) antibody at which human diploid cell measles vaccine was immunogenic. Eight weeks after administration of CEF measles vaccine containing 1% human albumin, antibody had developed in all 10 infants 7-10 months old and all 11 children 12-35 months old but in only 26% of 23 infants 3-5 months old and 67% of 9 infants 6 months of age. Failure of antibody development was associated with prevaccination PN antibody titers of greater than or equal to 1:50 (with one exception at a titer of 1:25). The PN antibody response to CEF vaccine (diluted 1:10, approximately 10(5) pfu/ml) in infants under seven months of age (geometric mean titer [GMT], 1:421) was significantly lower (P less than .005) than in older infants (GMT, 1:1,564). At a 1:1,000 dilution of vaccine, only 50% of 10 infants 13-25 months old, 20% of 15 infants 7-10 months old, and none of 8 infants 6 months old developed antibody.

[Retrospective study in hepatic biopsies, of hepatitis B surface antigen by the orcein method and indirect immunofluorescence methods]. / Estudo retrospectivo em biopsias hepáticas, do antígeno de superfície do vírus da hepatite B, pelos métodos de orceína e de immunofluorescência indireta.

A retrospective study of the HBsAg was done in 56 liver biopsies of children less than 12 year-old and 78 biopsies of adults. The study was performed by orcein stain and indirect immunofluorescent method. In 23 of the adults patients, the serological detection of HBsAg and antibodies (HbsAb) was determined by reverse passive haemagglutination technique. The adults patients' histological dianosis were variable and included acute or chronic hepatitis (20.5%) and cirrhosis (24.4%). Orcein was positive in 7 and IFI in 6 cases; 5 biopsies were positive by both methods. The highest incidence of HBsAg was seen in active cirrhosis (75%), including two cases of alcoholic cirrhosis. In the 23 serologically studied patients, 15 cases were HBsAg negative and 3 were HBsAg positive both in the liver and serum; only 2 cases showed discrepancy between these results. Three patients were HBsAb positive and HBsAg negative both in the liver and serum. All children biopsies were HBsAg negative. Among these patients, 26.8% had acute or chronic hepatitis and 10.7% cirrhosis. Serological and tissue techniques for HBsAg and HbsAb detection have different sensitivity. This should be kept in mind when studying the incidence of hepatitis B virus related to liver diseases.