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

A New Approach to Dengue Fatal Cases Diagnosis: NS1 Antigen Capture in Tissues

Dengue manifestations may vary from asymptomatic to potentially fatal complications. With an increasing number of Dengue Hemorrhagic fever (DHF) and fatal cases, the availability of new approaches useful for cases confirmation plays an important role for the disease surveillance. The diagnosis of fatal cases in frozen and fixed tissues from autopsies can be determined by techniques such as viral RT-PCR, in situ hybridization, viral proteins detection by immunohistochemistry and NS3 specific immunostaining. We aimed to assess for the first time the usefulness of NS1 capture tests as a diagnostic technique to demonstrate DENV antigens in human tissue specimens. The highest sensitivity was obtained by a rapid ICT which was also the most sensitive in liver, lung, kidney, brain, spleen and thymus. Despite a number of studies demonstrating the usefulness of DENV NS1 antigen detection by different ELISAs in plasma and/or sera of dengue patients, no research has been done previously to demonstrate NS1 presence in tissues of fatal dengue cases. Moreover, the application of NS1 kits to demonstrate the presence of DENV may provide a better understanding of viral tropism in fatal cases and may be useful for studies of pathogenesis in vivo and in experimental animals