J. Martin Kaplan

PASSIVE TRANSFER OF ANTIBODIES OF MATERNAL ORIGIN FROM BLOOD TO CEREBROSPINAL FLUID IN INFANTS

The demonstration that specific IgM antibodies are present in the serum of infants is useful in the diagnosis of several congenital infections. However, it is less certain whether the detection of antibodies in cerebrospinal fluid (c.s.f.) of infants indicates congenital infection of the central nervous system, because the origins of such antibodies have not been established. In the present study diphtheria and tetanus antitoxins of maternal origin have been detected both in the serum and in the c.s.f. of infants. These observations suggest that an important source of immunoglobulins in c.s.f. is passive transfer of antibodies from serum which should be considered in interpreting serological studies with c.s.f.

Pharmacologic studies in neonates given large dosages of ampicillin

The clinical pharmacology of ampicillin in neonates was studied. Ampicillin was effective in vitro against the common gram-pesitive pathogens and most E. coli causing neonatal bacterial diseases. Synergy was demonstrated in vitro for 40 per cent of E. coli using combinations of ampicillin and gentamicin. The pharmacokinetic properties of ampicillin in premature and full-term infants given 50, 75, or 100 mg. per kilogram per dose intramuscularly were investigated. Mean peak serum ampicillin values in premature infants 1 to 3 days of age were 104, 166, and 204 μg per milliter after 50, 75, and 100 mg. per kilogram per dose, respectively. There was no significant drug accumulation in serum and, half-life values were related inversely to postnatal age. Ampicillin levels in cerebrospinal fluid of 1 to 28 μg per milliliter after 40 to 70 mg. per kilogram per dose were 11 to 65 per cent, respectively, of the simultaneous serum values. Dosage recommendations are presented.

Infections in children caused by the HB group of bacteria

The HB bacteria are a group of fastidious gram-negative organisms of low pathogenicity and are unusual causes of infection in normal infants and children. Eight pediatric patients with infections caused by HB bacteria are presented. Six of these eight patients had deep tissue abscesses including empyema, meningitis, peritonitis, and osteomyelitis. These patients may have been predisposed to infection because of altered host defense mechanisms, underlying chronic diseases, or trauma. The HB bacteria morphologically resemble Hemophilus influenzae but are differentiated by their colonial formation and biochemical reactions. The HB bacteria are frequently resistant to penicillin and ampicillin. Treatment with tetracycline or chloramphenicol should be instituted until susceptibility studies are available.

Clinical pharmacology of benzatbine penicillin G in neonates with regard to its recommended use in congenital syphilis

Benzathine penicillin G has been recommended by the Center for Disease Control and the American Academy of Pediatrics for treatment of congenital syphilis in spite of the lack of published data concerning clinical pharmacology and efficacy of the drug in this disease. Five newborn infants received a single intramuscular dose of 50,000 units per kilogram of benzathine penicillin G. Peak serum levels of 0.38 to 2.1 μg per milliliter were observed at 24 hours, and concentrations of 0.07 to 0.09 μg per milliliter were measurable at 12 days after the dose. Penicillin activity was not detected in three of four cerebrospinal fluid samples. Because of this latter finding and until studies of clinical efficacy are available, benzathine penicillin G cannot be recommeded for treatment of congenital syphilis. Aqueous penicillin G is the drug of choice.