Simultaneous echocardiographic recording of the semilunar valves in patients with normally related great arteries.

On the echocardiograms of 2 infants with normally related great arteries, both semilunar valves were recorded simultaneously, a finding previously thought to be specific for d-transposition of the great arteries. Neither patient had d-transposition; in both cases the diagnosis was proved by cardiac catheterization.

Pharmacokinetics and antibacterial efficacy of cefpirome (HR 810) in experimental Escherichia coli and Haemophilus influenzae type b meningitis.

Cefpirome (HR 810) is a new cephalosporin related to cefotaxime that has potent bactericidal activity against a broad spectrum of gram-negative and gram-positive organisms. The pharmacokinetics and bacteriological efficacy of cefpirome administered as a single intravenous dose were assessed in rabbits with experimental Haemophilus influenzae type b and Escherichia coli K1 meningitis. The mean penetrations into the cerebrospinal fluid (CSF) in relation to the amount of drug in serum of animals infected with H. influenzae and E. coli were 25 and 54%, respectively. The median CSF bactericidal titers were 1:128 against both organisms at 1 h of uninfected animals, the mean penetration was 4.5%. There was a significant reduction in the concentrations of bacteria in CSFs of both groups of animals treated with cefpirome compared with that in untreated groups. Mortality was also significantly lower in treated animals than it was in untreated animals. Intravenous administration of dexamethasone before the cefpirome dose did not compromise penetration, bactericidal titers, or antibacterial activity of cefpirome in CSF.

Once-daily gentamicin therapy for experimental Escherichia coli meningitis.

In vitro and in vivo studies have demonstrated that the bacteriologic efficacy of once-daily aminoglycoside therapy is equivalent to that achieved with conventional multiple daily dosing. The impact of once-daily dosing for meningitis has not been studied. Using the well-characterized rabbit meningitis model, we compared two regimens of the same daily dosage of gentamicin given either once or in three divided doses for 24 or 72 h. The initial 1 h mean cerebrospinal fluid (CSF) gentamicin concentration for animals receiving a single dose (2.9 +/- 1.7 micrograms/ml) was threefold higher than that for the animals receiving multiple doses. The rate of bacterial killing in the first 8 h of treatment was significantly greater for the animals with higher concentrations in their CSF (-0.21 +/- 0.19 versus -0.03 +/- 0.22 log10 CFU/ml/h), suggesting concentration-dependent killing. By 24h, the mean reduction in bacterial titers was similar for the two regimens. In animals treated for 72 h, no differences in bactericidal activity was noted for 24, 48, or 72 h. Gentamicin at two different dosages was administered intracisternally to a separate set of animals to achieve considerably higher CSF gentamicin concentrations. In these animals, the rate of bacterial clearance in the first 8 h (0.52 +/- 0.15 and 0.58 +/- 0.15 log10 CFU/ml/h for the lower and higher dosages, respectively) was significantly greater than that in animals treated intravenously. In conclusion, there is evidence of concentration-dependent killing with gentamicin early in treatment for experimental E. coli meningitis, and once-daily dosing therapy appears to be at least as effective as multiple-dose therapy in reducing bacterial counts in CSF.