Evaluation of piperacillin-tazobactam in experimental meningitis caused by a beta-lactamase-producing strain of K1-positive Escherichia coli.

We evaluated the pharmacokinetics and therapeutic efficacy of piperacillin combined with tazobactam, a novel beta-lactamase inhibitor, in experimental meningitis due to a beta-lactamase-producing strain of K1-positive Escherichia coli. Different doses of piperacillin and tazobactam, as single agents and combined (8:1 ratio; dosage range, 40/5 to 200/25 mg/kg per h), and of ceftriaxone were given to experimentally infected rabbits by intravenous bolus injection followed by a 5-h constant infusion. The mean (+/- standard deviation) rates for penetration into the cerebrospinal fluid of infected animals after coadministration of both drugs were 16.6 +/- 8.4% for piperacillin and 32.5 +/- 12.6% for tazobactam. Compared with either agent alone, combination treatment resulted in significantly better bactericidal activity in the cerebrospinal fluid. The bactericidal activity of piperacillin-tazobactam was dose dependent: cerebrospinal fluid bacterial titers were reduced by 0.37 +/- 0.19 log10 CFU/ml per h with the lowest dose versus 0.96 +/- 0.25 log10 CFU/ml per h with the highest dose (P less than 0.001). At the relatively high doses of 160/20 and 200/25 mg of piperacillin-tazobactam per kg per h, the bactericidal activity of the combination was comparable to that of 10 and 25 mg of ceftriaxone per kg per h, respectively.

Methaemoglobin levels in young children consuming high nitrate well water in the United States.

The EPA limit for nitrate (10 mg/l No3-N) in drinking water was established to prevent infantile methaemoglobinemia, an acute condition confined almost exclusively to infants less than three months. This condition is clinically detectable at methaemoglobin levels of approximately 10%. Several studies in the Soviet Union have suggested that elevated methaemoglobin levels from ingested nitrate may not be confined to the young infant and have reported an association between increased methaemoglobin levels of up to 7% in schoolchildren and drinking water with a nitrate concentration of 23-204 mg/l NO3-N. an epidemiologic study of 102 children aged 1-8 conducted in Washington County, Illinois, did not show that ingestion of water with a nitrate concentration of 22-111 mg/l NO3-N was related to increasing methaemoglobin levels nor that the children had high or above normal methaemoglobin levels. The potential for transmission of infections waterborne disease in this area was demonstrated, however, as a large percentage of the wells used for drinking water contained high numbers of total and faecal coliforms.

Stuttering and oral stereognosis.

Two experiments were conducted to investigate oral stereognostic performance of stutterers. In Exp. I, stutterers and controls responded "same"--"different" to two oral forms placed successively on their tongues. In Exp. II, stutterers and controls underwent two procedures. For half the items, the task was the same as in Exp. I; for the other half, subjects were presented a single form and visually identified that form from among others on a placard. In both experiments, stutterers made significantly more oral stereognostic errors than did their matched controls.

Gentisic acid: a new stabilizer for low tin skeletal imaging agents: concise communication.

In vitro stabilization of low-tin bone-imaging agents has previously been achieved with ascorbic acid. In this study gentisic acid is shown to be an equally effective antioxidant for the (1-hydroxyethylidene) diphosphonate (HEDP) and hydroxymethylenediphosphonate (HMDP) skeletal agents. In vitro studies show less than 2% free sodium [99mTc] pertechnetate at 24 hr with the gentisic acid stabilizer. Studies in guinea pigs at 3 and 24 hr--whether with C-14 or H-3-labeled gentisic acid as stabilizer--show no alteration in the biodistribution of either skeletal imaging agent by the addition of the gentisic acid. Gentisic acid is a safe and effective stabilizer, and clinical studies have shown bioequivalency with ascorbic acid.

The effect of task variables on speech during oral anesthesia.

A normal, adult female performed a variety of speech tasks before and after a series of nerve-block injections that anesthetized the oral cavity. The tasks included diadokokinesis, imitation of unfamiliar Swedish phonemes, production of one-, two-, three-, and four-syllable words, and of two prose passages. Four experienced judges scored misarticulations. Intelligibility was determined in a series of listening studies involving college students. The highest percentage of misarticulations occurred on the single-syllable word list and the most complex prose passage. There were virtually no misarticulations on the two- or three-syllable words. Intelligibility tended to covary with articulation, but the specific nature of the relationship depended on the particular speech task. A misarticulation was especially likely to result in unintelligibility on the most difficult passage, although not all unintelligible words on that passage were attributable to phonemic errors.