Accumulation of 99mTc-Labeled Defensins 1–3 and Ciprofloxacin in Infections and Inflammatory Lesions
| 99mTc-labeled compound | S. aureus* | K. pneumoniae | C. albicans† | LPS | Heat-killed microorganisms |
|---|---|---|---|---|---|
| Defensins 1–3 | 2.9 ± 0.2 | 1.9 ± 0.1 | 2.9 ± 0.2 | 1.0 ± 0.1 | 1.4 ± 0.2 |
| Ciprofloxacin | 1.8 ± 0.1 | 1.7 ± 0.1 | 2.5 ± 0.1 | 1.9 ± 0.1 | 1.7 ± 0.2 |
Anesthetized mice were injected into right thigh muscle with 1 × 107 CFU of microorganisms, and 18 h thereafter, 0.2 mL saline containing 99mTc-labeled defensins or ciprofloxacin was injected intravenously (2). Sterile inflammatory process was induced in mice by injection with either 50 μg LPS or 1 × 108 heat-killed microorganisms 24-h prior to injection of tracer. Next, accumulation of tracer in infected and inflamed muscle was assessed by planar scintigraphy. On scintigrams, anatomically adjusted regions of interest were drawn over infected/inflamed (target) and contralateral (nontarget) thigh muscle, providing reasonable estimation of accumulation of radiolabeled tracer in infected/inflamed sites. Results are expressed as target to nontarget ratio (T/NT) (1,2). Values represent mean (±SEM) T/NT for 99mTc-labeled defensins 1–3 and ciprofloxacin observed between 30 min and 120 min after injection of the tracer. Results are from at least 8 mice in 3 independent experiments.
↵* Multi–drug-resistant S. aureus type 2141 is a clinical isolate (Dept. of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands).
↵† Fluconazole-resistant C. albicans Y-01 was obtained from Pfizer Inc., New York, New York.