Search PubMed⌕ Search

Biomedical subjects

J B Howard

Publications and source records attributed to J B Howard.

At least 91 records · Page 5Linked to original sources
PubMed1976

A prolonged nursery epidemic associated with a newly recognized type of group A streptococcus.

During a six-month period 69 infants in a newborn nursery were colonized with group A streptococci. Fifty-one had omphalitis, two infected circumcision wounds, and one each had meningitis, primary peritonitis, and conjunctivitis. Thirteen infants were asymptomatically colonized. Control of the epidemic was difficult. Benzathine penicillin prophylaxis to all infants suppressed active infection but did not eradicate asymptomatic colonization of the umbilical cord. Triple dye treatment of the umbilical cord plus benzathine penicillin prophylaxis eradicated the infection from the nursery. The epidemic streptococcus was a newly recognized ""skin strain,'' provisional type strain 5656-S, not previously known to cause epidemic disease or serious systemic infections.

Disease Outbreaks↗
PubMed1976

Amikacin in newborn infants: comparative pharmacology with kanamycin and clinical efficacy in 45 neonates with bacterial diseases.

The pharmacokinetic properties of amikacin (BBK8) were similar to those of kanamycin in newborn infants. Peak serum concentrations of both drugs were in the range of 15 to 25 mug/ml with the exception of kanamycin in babies weighing greater than 2,000 g at birth where peak levels were 12.5 to 15 mug/ml. Volumes of distribution, plasma clearances, and serum half-life values were comparable for the two drugs. The clinical and bacteriological responses to amikacin therapy were assessed in 45 neonates with bacterial diseases. A case fatality rate of 26% was observed in infants with septicemia and/or meningitis, whereas no deaths occurred among 22 infants with urinary tract and mucocutaneous infections. Cultures from infected sites were sterile within 72 h of initiating amikacin therapy in 47% of the infants, continued positive for greater than 72 h in 31%, and were not reevaluated during therapy in 22%. The clinical response was judged to be satisfactory in 92% of the surviving infants. The efficacy of amikacin was comparable to that of kanamycin or gentamicin in neonatal bacterial diseases.

Amikacin↗
PubMed1975

Amino acid sequence of a vitamin K-dependent Ca2+-binding peptide from bovine prothrombin.

The amino acid sequence of a 31-residue peptide from bovine prothrombin has been determined. This peptide has been shown to contain the vitamin K-dependent modification required for Ca2+ binding (Nelsestuen, G. L., and Suttie, J. W. (1973) Proc. Natl. Acad. Sci. U. S. A. 70, 3366-3370) and the modified amino acid, gamma-carboxyglutamic acid (Nelsestuen, G. L., Zytkovicz, T., and Howard, J. B. (1974) J. Biol. Chem. 249, 6347-6350). The peptide was shown to correspond to residues 12 to 42 of prothrombin.

Amino Acid Sequence↗
PubMed1975

Reappraisal of kanamycin usage in neonates.

This study documents an important change in the kanamycin in susceptibilites of Escherichia coli strains cultivated from neonates. Whereas some nurseries have in the past experienced resistance rates as high as 70 per cent recent survelliance of seven North American nurseries demonstrated that 90 percent or more of E. coli strains are currently susceptible to kanamycin. Pharmacokinetic studies of 65 babies treated with either 7.5 or 10 mg/kg kanamycin doses revealed that peak serum values varied with dosage, birthweight, and chronologic age. Peak serum levels were below the desired therapeutic range in many babies treated with 7.5 mg/kg doses of kanamycin every 12 hours. Concentrations in cerebrospinal fluid specimens from 21 infants were 0.5 to 12 mu/ml after 7.5 mg/kg kanamycin doses. Calculated distribution volumes, plasma clearances, and serum half-life values were used in formulating a revised kanamycin in dosage and frequency of administration schedule.

Age Factors↗
PubMed1975

Isolation and characterization of vitamin K-dependent region of bovine blood clotting factor X.

A 39-residue peptide from the tryptic digestion of bovine blood clotting factor X has been isolated by specific adsorption on barium citrate. The amino- and carboxyl-terminal sequences of the peptide were determined and compared to the vitamin K-dependent Ca2+-binding region from bovine prothrombin. The factor X peptide was found to contain gamma-carboxyglutamic acid residues, and the results of independent analysis are consistent with all 14 glutamic acid residues as gamma-carboxyglutamic acid. The similarity of the factor X peptide to the prothrombin peptide supports the hypothesis that the vitamin K-dependent blood clotting proteins are descended from a common ancestral gene.

Amino Acid Sequence↗
PubMed1975

Pharmacological evaluation of amikacin in neonates.

The in vitro bacterial susceptibilities and pharmacokinetic properties of amikacin (BB-K8) were studied in newborn infants. Gram-negative bacteria and Staphylococcus aureus isolated from neonates were uniformly susceptible to 10 mug or less of amikacin per ml, and five Escherichia coli strains resistant to kanamycin were inhibited and killed by 5 mug or less of amikacin per ml. Mean peak serum concentrations of 17 to 20 mug/ml were observed 30 min after 7.5-mg/kg amikacin doses, and accumulation of drug in serum was not detected after repeated doses for 5 to 7 days. Intravenous infusion of amikacin over a 20-min period resulted in extremely low peak serum levels in four of eight infants studied. Serum half-life values were correlated inversely with postnatal age and renal clearances of amikacin. The volumes of drug distribution indicate that amikacin remains primarily in the extracellular fluid space of neonates. The lack of efficacy and safety data preclude the use of amikacin in neonates at this time.

Amikacin↗