Comparison of oral penicillinase-resistant penicillins: contrasts between agents and assays.

We observed the comparative serum levels and mean peak serum antistaphylococcal activity in eight fasting adults who received 500 mg each of dicloxacillin, cloxacillin, oxacillin, and nafcillin. Dicloxacillin achieved higher and more prolonged serum levels and greater peak serum antistaphylococcal titers than the other drugs studied. The higher degree of protein binding of dicloxacillin was reflected in a greater disparity between the peak antistaphylococcal activity observed when dilutions were done in serum compared to broth. The lesser protein-bound penicillins showed less disparity, but this effect was offset by the higher serum levels obtained by dicloxacillin. The higher protein binding of dicloxacillin did not prevent its having equal or superior antistaphylococcal activity in serum when the drugs were given in equal doses.

Screening for cell-mediated immunity in children.

Skin testing and in vitro lymphocyte blastogenesis with Monilia and tetanus toxoid were examined as methods of screening cell-mediated immunity (CMI) in infants and children. With increasing age, all assays were more likely to be positive. Tetanus toxoid was a better single screening antigen than Monilia, particularly for young infants. Combining all assays, at least one was positive in 88% of children over 6 weeks of age. Combining the two skin tests, at least one was positive in 73% of children in the same age range. Results for the blastogenic assays indicated that this in vitro test is more sensitive than the in vivo skin test for demonstrating CMI to these two antigens. Infants with documented histories for Monilia diaper rash had a significantly higher probability of having a positive skin or blastogenic reaction with Monilia.