ABSTRACT
The Tibet experiment, operating at Yangbajing (4300 m above sea level), is the lowest energy air shower array, and the new high-density array constructed in 1996 is sensitive to gamma-ray air showers at energies as low as 3 TeV. With this new array, the Crab Nebula was observed in multi-TeV gamma-rays and a signal was detected at the 5.5 sigma level. We also obtained the energy spectrum of gamma-rays in the energy region above 3 TeV which partially overlaps those observed with imaging atmospheric Cerenkov telescopes. The Crab spectrum observed in this energy region can be represented by the power-law fit dJ&parl0;E&parr0;&solm0;dE=&parl0;4.61+/-0.90&parr0;x10-12&parl0;E&solm0;3 TeV&parr0;-2.62+/-0.17 cm-2 s-1 TeV-1. This is the first observation of gamma-ray signals from point sources with a conventional air shower array using scintillation detectors.
ABSTRACT
Tazobactam/Piperacillin (TAZ/PIPC) is a newly developed intravenous antibiotics, in which TAZ, a new potent inhibitor of beta-lactamases, is combined with PIPC, a well-established beta-lactam antibiotics, at the ratio of 1:4. In this study, we clinically evaluated efficacy of the drug in 14 pediatric patients with various infections, and pharmacokinetic study was applied to 3 patients. Range of age was from 1-month to 15 1/4-year. Patients consisted of 9 cases of pneumonia, 3 urinary tract infection, 1 acute otitis media, and 1 left sacroiliitis with sepsis. Standard dose of TAZ/PIPC was 50 mg/kg/dose and administered 2-4 times per day with intravenous injection or drip infusion. Two cases of pneumonia were excluded because of non-bacterial infection. Nine causative pathogens including 3 Gram-positive cocci and 6 Gram-negative bacilli were detected in 7 patients, of which 5 Gram-negative strains produced bete-lactamase. All of cases showed 100% of efficacy rate and bacteriological eradication rate. It was noted that beta-lactamase-producing E. coli and B. catarrhalis were eradicated efficiently by TAZ/PIPC, which should be resistant to PIPC alone according to MIC data. Non-serious diarrhea and discomfort of back with nausea were observed in one each patients as side effects. Both of side effects were transient, and improved with anti-diarrheic agent or cessation of the drug, respectively. As abnormal laboratory test results, moderate increases of the eosinophils and platelets counts as well as moderate elevation of the transaminases were observed in 2 separate patients. Pharmacokinetics study showed that Cmax, T1/2, and AUC were similar to the data reported in adult patients. Urinary recovery rate in the first 6 hours also resemble the data from adult patients. Based on above results, TAZ/PIPC is a useful agents pediatric infections by beta-lactamase producing strains also.
