A Magnetic Resonance-based Seed Localization Method for I-125 Prostate Implants

This study was performed to develop and evaluate a semi-automatic seed localization algorithm from magnetic resonance (MR) images for interstitial prostate brachytherapy. The computerized tomography (CT) and MR images (3 mm-slice thickness) of six patients who had received real-time MR imaging-guided interstitial prostate brachytherapy were obtained. An automatic seed localization method was performed on CT images to obtain seed coordinates, and an algorithm for seed localization from MR images of the prostate was developed and tested. The resultant seed distributions from MR images were then compared to CT-derived distribution by matching the same seeds and calculating percent volume receiving 100% of the prescribed dose and the extent of the volume in 3-dimensions. The semiautomatic seed localization method made it possible to extract more than 90% of the seeds with either less than 8% of noises or 3% of missing seeds. The mean volume difference obtained from CT and MR receiving 100% of the prescribed dose was less than 3%. The maximum extent of the volume receiving the prescribed dose were 0.3, 0.6, and 0.2 cm in x, y, and z directions, respectively. These results indicate that the algorithm is very useful in identifying seeds from MR image for post-implant dosimety.

In Vitro Activities of Gatifloxacin against Bacteria isolated from Respiratory Specimens of Patients of University Hospitals in Korea / 감염과화학요법

BACKGROUND: Gatifloxacin, a new 8-methoxyquinolone, has a broad-spectrum activity with expanded potency against respiratory pathogens. In this study, we examined the in vitro activity of gatifloxacin and comparators against recently isolated bacteria from respiratory specimens of patients in Korean hospitals. METHODS: Forty-nine isolates were from respiratory specimens of patients with acute exacerbations of chronic lower respiratory infections in eight university hospitals and 108 isolates were from respiratory specimens from patients of Yonsei University Hospital. Minimum inhibitory concentrations (MICs) were determined by NCCLS agar dilution method. RESULTS: MIC90 of gatifloxacin for Streptococcus pneumoniae was 1 g/mL, which was 8-fold and 2-fold lower than those of ciprofloxacin and levofloxacin, respectively. All strains of Haemophilus in fluenzae and Moraxella (Branhamella) catarrhalis were inhibited by < or =0.06 g/mL and < or =0.25 g/mL of gatifloxacin, respectively, and were susceptible to all fluoroquinolones tested. MIC90 of gatifloxacin for Klebsiella pneumoniae was 0.06 g/mL, which was 2-fold lower than those of levofloxacin and moxifloxacin. CONCLUSION: Gatifloxacin is highly active against S. pneumoniae, H. influenzae and M. (B.) catarrhalis isolated from respiratory specimens of patients of university hospitals in Korea.

In Vitro Activities of Gatifloxacin against Bacteria isolated from Respiratory Specimens of Patients of University Hospitals in Korea / 감염과화학요법

BACKGROUND: Gatifloxacin, a new 8-methoxyquinolone, has a broad-spectrum activity with expanded potency against respiratory pathogens. In this study, we examined the in vitro activity of gatifloxacin and comparators against recently isolated bacteria from respiratory specimens of patients in Korean hospitals. METHODS: Forty-nine isolates were from respiratory specimens of patients with acute exacerbations of chronic lower respiratory infections in eight university hospitals and 108 isolates were from respiratory specimens from patients of Yonsei University Hospital. Minimum inhibitory concentrations (MICs) were determined by NCCLS agar dilution method. RESULTS: MIC90 of gatifloxacin for Streptococcus pneumoniae was 1 g/mL, which was 8-fold and 2-fold lower than those of ciprofloxacin and levofloxacin, respectively. All strains of Haemophilus in fluenzae and Moraxella (Branhamella) catarrhalis were inhibited by < or =0.06 g/mL and < or =0.25 g/mL of gatifloxacin, respectively, and were susceptible to all fluoroquinolones tested. MIC90 of gatifloxacin for Klebsiella pneumoniae was 0.06 g/mL, which was 2-fold lower than those of levofloxacin and moxifloxacin. CONCLUSION: Gatifloxacin is highly active against S. pneumoniae, H. influenzae and M. (B.) catarrhalis isolated from respiratory specimens of patients of university hospitals in Korea.

Clinical Utility of Bronchial Washing PCR for IS6110 and Amplicor for the Rapid Diagnosis of Active Pulmonary Tuberculosis in Smear Negative Patients / 결핵

BACKGROUND: There is a well recognized interlaboratory variation in the results using the polymerase chain reaction(PCR) to detect the IS6110 sequence. The clinical utility of a commercially developed PCR test(Amplicor) in bronchial washings for detecting pulmonary tuberculosis in smear negative patients was evaluated. The sensitivity and specificity of Amplicor was compared with that of an in-house PCR test used for detecting the IS6110 sequence of Mycobacterium tuberculosis(M.tbc) in the bronchial washing fluid. METHODS: 66 patients whose sputum smear for M.tbc were negative or who could not produce any sputum were recruited from January 1999 to July 1999. They all had a bronchoscopy performed to determine if there were signs of hemoptysis, patients who could not cough up sputum, lung lesion that exclude pulmonary tuberculosis. Pulmonary tuberculosis was diagnosed on the basis of a positive culture or a response to anti-tuberculosis therapy. RESULTS: 19 patients with tuberculosis were identified and samples from 16 patients were later confirmed by culture. Bronchial washing for Amplicor PCR revealed a sensitivity, specificity, positive and negative predictive values of 94.7%, 97.9%, 94.7%, 97.9%, respectively. Using IS6110 based PCR, the sensitivity, specificity, positive and negative predictive values were of 73.7%, 87.2%, 70%, 89.1% respectively. CONCLUSION: Bronchial washing for Amplicor PCR proved to be more useful than IS6110 based PCR in rapidly diagnosing smear negative pulmonary pulmoary tuberculosis in patients where tuberculosis was likely to be differential and rapid diagnosis was essential for optimal treatment.