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Biomedical subjects

W C Hellinger

Publications and source records attributed to W C Hellinger.

4 recordsLinked to original sources

Continuous intravenous versus intermittent ampicillin therapy of experimental endocarditis caused by aminoglycoside-resistant enterococci.

We studied the efficacy of continuous intravenous infusion of ampicillin compared with that of intermittent administration of ampicillin alone or in combination with gentamicin for the therapy of highly aminoglycoside-resistant enterococcal experimental endocarditis. Rabbits were infected with a gentamicin-susceptible (MIC, 256 micrograms/ml) strain of Enterococcus faecalis or a strain of E. faecalis which was highly resistant to gentamicin in vitro (MIC, greater than 2,000 micrograms/ml). Administration of ampicillin by continuous intravenous infusion did not significantly enhance the killing of enterococci in vivo compared with that by intermittent administration of ampicillin for either the aminoglycoside-susceptible or the aminoglycoside-resistant strain. In combination with gentamicin, there were no significant differences in efficacies obtained with intermittent versus continuous intravenous infusion of ampicillin therapy for experimental endocarditis caused by either strain of E. faecalis.

Ampicillin

Imipenem.

Imipenem is the first of a new class of beta-lactam antibiotics, the carbapenems, to be released for clinical use. It has the broadest antibacterial activity of all antibiotics available for systemic use in humans. It is active against streptococci, methicillin-sensitive staphylococci, Neisseria, Haemophilus, anaerobes, and the common aerobic gram-negative nosocomial pathogens including Pseudomonas. Resistance to imipenem may emerge during treatment of P. aeruginosa infections, as has occurred with other beta-lactam agents; P. maltophilia and P. cepacia are typically resistant to it. Like the penicillins, imipenem has inhibitory activity against enterococci. Daily doses may range from 500 mg to 1 g, every 6 to 8 hours, in patients with normal renal function. The principal toxic effects have been nausea and vomiting, which occur during intravenous infusion, and seizures, which develop in 1 to 3% of treated patients and are likely to occur in the setting of renal insufficiency and underlying disease of the central nervous system. Imipenem should be considered for treatment of mixed bacterial infections and treatment of resistant aerobic gram-negative bacteria that are not susceptible to other beta-lactam agents. In addition to provoking unnecessary toxicity, indiscriminate use of this agent will promote dissemination of resistance against it.

Humans

The monobactams.

The monobactam antibiotics are synthetic compounds, although monocyclic beta-lactam compounds have been found in nature in various soil bacteria. Although additional orally and parenterally administered monobactams are under investigation, the first marketed monobactam was aztreonam. This agent has an antimicrobial spectrum similar to that of gentamicin and tobramycin, aminoglycoside antibiotics. Aztreonam, however, is not nephrotoxic, is weakly immunogenic, and has not been associated with disorders of coagulation. Aztreonam may be administered intramuscularly or intravenously; absorption after oral administration is poor. The primary route of elimination is the urine. The serum half-life of the drug in patients with normal renal function is 1.5 to 2.1 hours; the recommended dosing interval in patients with normal renal function is every 8 hours. Dosage adjustment is necessary in patients with renal impairment. The strictly gram-negative aerobic spectrum of aztreonam limits its use as a single empiric agent. Approved indications for its use include infections of the urinary tract or lower respiratory tract, intra-abdominal and gynecologic infections, septicemia, and cutaneous infections caused by susceptible organisms. Concurrent initial therapy with other antimicrobial agents is recommended before the causative organism (or organisms) has been determined in patients who are seriously ill and at risk for gram-positive or anaerobic infections.

Humans

Chronic fatigue syndrome and the diagnostic utility of antibody to Epstein-Barr virus early antigen.

Antibody to Epstein-Barr virus (EBV) early antigen has been said to be the most specific indicator of symptomatic chronic EBV infection. We studied the clinical utility of this serologic test in the evaluation of patients with chronic fatigue. Thirty patients with chronic fatigue and highly elevated titers of antibody to early antigen (greater than or equal to 1:160) were compared with 30 age- and sex-matched controls with no antibody to early antigen. There were no significant differences noted between patients and controls at the initial evaluation (symptoms, physical examination, laboratory data). Follow-up information, available for 15 matched pairs, showed no differences in outcome between patients and controls. We conclude that the antibody to EBV early antigen is not helpful in the clinical evaluation of patients with chronic fatigue.

Antibodies, Viral