Antibody response to heat-inactivated hepatitis B vaccine (CLB-3mg) in hemodialysis patients and occupational risk personnel: a one year follow-up

A resposta imune contra vacina de hepatite B (CLB-3mg) foi avaliada em 59 pacientes de hemodiálise e 20 funcionários de risco em adquirir infecção. A soroconversão foi observada em 52,5% e 70,0%, respectivamente. Um ano após a primeira dose, os níveis de anticorpos anti-HBs foram determinados em 37.5% dos pacientes e 60.0% dos funcionários. Os níveis de anticorpos foram expressos em unidades de radioimunoensaio (SRU = contagem da amostra sobre o controle negativo). Considerando apenas os indivíduos que responderam à vacina, no grupo de pacientes, 38.7% tiveram resposta baixa de anticorpos (2,1 - 9,9 SRU), 32,3% resposta média e 29,0% uma resposta elevada (>; SRU), enquanto que no pessoal de risco, os valores foram 14,3%, 64,3% e 21.4%, respectivamente. Os autores sugerem o uso de vacinas de HBV com concentrações de HBsAg mais elevada ou um reforço no esquema de imunização para melhorar a resposta de anti-HBs, não só para pacientes como também para pessoas sadias.Immune response against hepatitis B vaccine (CLB 3mg) was evaluated in 59 hemodialysis patients and 20 occupational risk personnel. Seroconversion was induced in 52.5% and 70.0% respectively. Twelve months after the first dose, 37.5% of patients and 60.0% of occupational risk personnel had detectable anti-HBs level. Antibody level was expressed in sample ratio units (SRU). Considering only the responders, in the patients group 38.7% had a low anti-HBs response (2.1-9.9 SRU) 32.3% a medium response (10-99.9 SRU) and 29.0% a high response (>;100 SRU) while in occupational risk personnel these values were 14.3%, 64.3% and 21.4% respectively. The authors suggest the use of HBV vaccines with more elevated HBsAg concentration or a reinforced immunization schedule to improve the anti-HBs response not only for patients but also for healthy persons

Isolation and purification of an enzyme hydrolyzing ochratoxin A from aspergillus niger

Ochratoxin A is a mycotoxin produced by several Aspergillus and some Penicillium species which may be present in food and feed products. It can be enzymatically hydrolyzed into ochratoxin α and l-β-phenylalanine, thereby decreasing its toxicity. The ochratoxin A degradation capacity of Aspergillus niger is well known and here we report the isolation and purification of a novel enzyme from A. niger that hydrolyzes this mycotoxin. A wheat germ medium supplemented with ochratoxin A was used to produce the enzyme, which was purified from culture filtrate by acetone precipitation and anion exchange chromatography. An overall purification of 2.5-fold with a recovery of 68% and a final specific activity of 36 U/mg was obtained. The enzyme is a metalloenzyme as it was inhibited at 10 mM EDTA, whereas PMSF had no effect. The ochratoxin A hydrolytic enzyme presented a V max of 0.44 μM/min and a K m of 0.5 mM when the reaction was carried out at pH 7.5 and 37°C.Fundação para a Ciência e a Tecnologia (FCT