Quality of horse F(ab)2 antitoxins and antirabies immunoglobulins: protein content and anticomplementary activity

Background Among other applications, immunotherapy is used for the post-exposure treatment and/or prophylaxis of important infectious diseases, such as botulism, diphtheria, tetanus and rabies. The effectiveness of serum therapy is widely proven, but improvements on the immunoglobulin purification process and on the quality control are necessary to reduce the amount of protein aggregates. These may trigger adverse reactions in patients by activating the complement system and inducing the generation of anaphylatoxins. Herein, we used immunochemical methods to predict the quality of horse F(ab)2 anti-botulinum AB, anti-diphtheric, antitetanic and anti-rabies immunoglobulins, in terms of amount of proteins and protein aggregates. Methods Samples were submitted to protein quantification, SDS-PAGE, Western blot analysis and molecular exclusion chromatography. The anticomplementary activity was determined in vitro by detecting the production of C5a/C5a desArg, the most potent anaphylatoxin. Data were analyzed by one-way ANOVA followed by Tukey's post-test, and differences were considered statistically significant when p 0.05. Results Horse F(ab)2 antitoxins and anti-rabies immunoglobulin preparations presented different amounts of protein. SDS-PAGE and Western blot analyses revealed the presence of protein aggregates, non-immunoglobulin contaminants and, unexpectedly, IgG whole molecules in the samples, indicating the non-complete digestion of immunoglobulins. The chromatographic profiles of antitoxins and anti-rabies immunoglobulins allowed to estimate the percentage of contaminants and aggregates in the samples. Although protein aggregates were present, the samples were not able to induce the generation of C5a/C5a desArg in vitro, indicating that they probably contain acceptable levels of aggregates...

Efeito da fosfina sobre a produçäo de aflatoxinas em amendoim armazenado com elevado teor de umidade / Effect of phosphine on aflatoxin production in peanuts stored with high moisture content

Amendoim recém-colhido, descascado, reumedecido até 0,89 de atividade de água (15,6 por cento de teor de umidade em base úmida) foi exposto a 0,0, 0,5, 1,0 e 1,5 mg/l de fosfina durante 3,7 e 14 dias a 30 por cento e aproximadamente 85 por cento de umidade relativa. As concentraçöes de CO2 foram determinadas após cada período de exposiçäo. Análises das aflatoxinas B1 e G1 foram conduzidas inicialmente e após tratamento. Os teores de CO2 obtidos indicaram que a fosfina nas doses de 1,0 e 1,5 mg/l impediu o desenvolvimento fúngico durante todo o período estudado (14 dias), enquanto a concentraçäo de 0,5 mg/l foi eficiente até 7 dias de estocagem. As 3 doses estudadas controlaram a produçäo de aflatoxinas B1 e G1. O período de proteçäo oferecido pelo fumigante no controle do desenvolvimento fúngico e na produçäo dessas micotoxinas foi relacionado com as doses utilizadas