No abstract

A method for the screening of tetanus and diphtheria antibodies in serum using anatoxin (inactivated toxin) instead of toxin was developed as an alternative to the in vivo toxin neutralization assay based on the toxin-binding inhibition test (TOBI test). In this study, the serum titers (values between 1.0 and 19.5 IU) measured by a modified TOBI test (Modi-TOBI test) and toxin neutralization assays were correlated (P < 0.0001). Titers of tetanus or diphtheria antibodies were evaluated in serum samples from guinea pigs immunized with tetanus toxoid, diphtheria-tetanus or triple vaccine. For the Modi-TOBI test, after blocking the microtiter plates, standard tetanus or diphtheria antitoxin and different concentrations of guinea pig sera were incubated with the respective anatoxin. Twelve hours later, these samples were transferred to a plate previously coated with tetanus or diphtheria antitoxin to bind the remaining anatoxin. The anatoxin was then detected using a peroxidase-labeled tetanus or diphtheria antitoxin. Serum titers were calculated using a linear regression plot of the results for the corresponding standard antitoxin. For the toxin neutralization assay, L+/10/50 doses of either toxin combined with different concentrations of serum samples were inoculated into mice for antitetanus detection, or in guinea pigs for anti-diphtheria detection. Both assays were suitable for determining wide ranges of antitoxin levels. The linear regression plots showed high correlation coefficients for tetanus (r 2 = 0.95, P < 0.0001) and for diphtheria (r 2 = 0.93, P < 0.0001) between the in vitro and the in vivo assays. The standardized method is appropriate for evaluating titers of neutralizing antibodies, thus permitting the in vitro control of serum antitoxin levels.

No abstract

Samples from 20 lots of diphtheria-tetanus (adult use dT)

Aprotinin, the most studied serine proteinase inhibitor, was isolated from porcine lung for the first time. The purified porcine aprotinin had an Mr value of approximately 7 kDa. It cross-reacted with polyclonal serum anti-commercial aprotinin. About 1 microg porcine aprotinin inhibited 6 microg trypsin whereas 1 microg commercial soybean inhibitor inhibited only 1 microg trypsin. The aprotinin gene was also isolated from porcine lung: the deduced amino acid sequence showed 74% identity to bovine aprotinin.