Medical Thoracoscopy in Pleural Disease: Experience from a One-Center Study / 결핵및호흡기질환

BACKGROUND: Medical thoracoscopy (MT) is a minimally invasive, endoscopic procedure for exploration of the pleural cavity under conscious sedation and local anesthesia. MT has been performed at the Seoul National University Hospital since February 2014. This paper summarizes the findings and outcomes of MT cases at this hospital. METHODS: Patients who had undergone MT were enrolled in the study. MT was performed by pulmonologists, using both rigid and semi-rigid thoracoscopes. During the procedure, patients were under conscious sedation with fentanyl and midazolam. Medical records were reviewed for clinical data. RESULTS: From February 2014 to January 2016, 50 procedures (47 cases) were performed (diagnostic MT, 26 cases; therapeutic MT, 24 cases). The median age of patients was 66 years (59–73 years), and 38 patients (80.9%) were male. The median procedure duration from initial incision to insertion of the chest tube was 37 minutes. The median doses of fentanyl and midazolam were 50 µg and 5 mg, respectively. All procedures were performed without unexpected events. Of the 26 cases of pleural disease with an unknown cause, 19 were successfully diagnosed using MT. Additionally, diagnostic MT provided clinically useful information in the other six patients. Therapeutic MT was very effective for treatment of malignant pleural effusion or empyema. The median number of days with chest tube drainage was 6 (3 days for diagnostic MT and 8 days for therapeutic MT). CONCLUSION: MT is a useful and necessary procedure for both diagnosis and treatment of pleural diseases.

Bacterial Yield from Quantitative Cultures of Bronchoalveolar Lavage Fluid in Patients with Pneumonia on Antimicrobial Therapy

BACKGROUND/AIMS: Early diagnosis and appropriate antimicrobial choice are crucial when managing pneumonia patients, and quantitative culture of bronchoalveolar lavage (BAL) fluid is considered a useful method for identifying pneumonia pathogens. We evaluated the quantitative yield of BAL fluid bacterial cultures in patients being treated with antimicrobials and attempted to identify factors predictive of positive BAL cultures. METHODS: Patients over 18 years old and whose BAL fluid was subjected to quantitative culture to identify the organism causative of pneumonia between January 1, 2005, and December 31, 2009, were included. We reviewed the results of BAL fluid bacterial cultures and the clinical records, laboratory tests, and radiographic findings of the patients. RESULTS: BAL was performed on 340 patients with pneumonia. A positive BAL culture, defined as isolation of more than 10(4) colony forming units/mL bacteria, was documented in 18 (5.29%) patients. Of these, 9 bacteria isolated from 10 patients were classified as probable pathogens. The most frequently isolated bacteria were methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa. No independent predictive factor for positive BAL cultures was identified. CONCLUSIONS: The yield of quantitative BAL fluid bacterial culture in patients already on antimicrobials was low. Clinicians should be cautious when performing a BAL culture in patients with pneumonia who are already on antimicrobials.

The Interval Between Initiation of Anti-tuberculosis Treatment in Patients with Culture-positive Pulmonary Tuberculosis and Receipt of Drug-susceptibility Test Results

Although mycobacterial culture and the subsequent drug-susceptibility test (DST) for anti-tuberculosis (TB) drugs take several months to complete using solid media, there are no reports on the turnaround times of these tests under clinical conditions. The aim of this study was to determine the interval between initiation of anti-TB treatment and receipt of DST requested at an outpatient clinic. We prospectively enrolled patients with culture-positive pulmonary TB at Seoul National University Hospital from September 2002 to December 2004. Patients were followed up monthly. Mycobacterial cultures were done using Ogawa media at Seoul National University Hospital. DST were performed at the Korean Institute of Tuberculosis. Of the 104 patients enrolled, 54 were male. The median age was 41 yr. The median interval from initiation of anti-TB treatment to receipt of mycobacterial culture results by clinicians was 37 days (range, 0-89 days). The median interval from initiation of treatment to confirmation of DST by requesting clinicians was 80.5 days (range, 28-145 days). Clinicians only received the results of DST more than two months after initiation of treatment when they followed up patients monthly and mycobacterial culture was performed using solid media.

Superoxide Dismutase Gene Expression Induced by Lipopolysaccharide in Alveolar Macrophage of Rat / 결핵

BACKGROUND: In the pathogenesis of acute lung injury induced by lipopolysaccharide(LPS), oxygen radiclls are known to be involved in one part. Superoxide dismutase(SOD) protects oxygen radical-induced tissue damage by dismutating superoxide to hydrogen peroxide. In eukaryotic cells, two forms of SOD exist intracellularly as a cytosolic, dimeric copper/zinc-containing SOD (CuZnSOD) and a mitochondrial, tetrameric manganese-containing SOD(MnSOD). But there has been little information about SOD gene expression and its regulation in pulmonary alveolar macrophages(PAMs). The objective of this study is to evaluate the SOD gene expression induced by LPS and its regulation in PAMs of rat. METHOD: In Sprague-Dawley rats, PAMs obtained by broncholaveolar lavage were purified by adherence to plastic plate. To study the effect of LPS on the SOD gene expression of PAMs, they were stimulated with different doses of LPS(0.01microg/ml ~ 10microg/ml) and for different intervals(0, 2, 4, 8, 24hrs). Also for evaluating the level of SOD gene regulation actinomycin D(AD) or cyclo- heximide(CHX) were added respectively. To assess whether LPS altered SOD mRNA stability, the rate of mRNA decay was determined in control group and LPS-treated group. Total cellular RNA extraction by guanidinium thiocyanate/phenol/chloroform method and Northern blot analysis by using a 32P-labelled rat MnSOD and CuZnSOD cDNAs were performed. RESULTS: The expression of mRNA in MnSOD increased dose-dependently, but not in CuZnSOD. MnSOD mRNA expression peaked at 8 hours after LPS treatment. Upregulation of MnSOD mRNA expression induced by LPS was suppressed by adding AD or CHX respectively. MnSOD mRNA stability was not altered by LPS. CONCLUSION: These findings show that PAMs of rat could be an important source of SOD in response to LPS, and suggest that their MnSOD mRNA expression may be regulated transcriptionally and require de novo protein synthesis without affecting mRNA stability.

Superoxide Dismutase Gene Expression in the Endotoxin-Treated Rat Lung / 결핵

BACKGROUND: It is well known that oxygen free radicals (OFR) play a vital role in the various type of acute lung injury. Among various antioxidant defense mechanisms, the superoxide dismutases (SOD) are thought to be the first line of antioxidant defense by catalyzing the dismutation of two superoxide radicals to yield hydrogen peroxide and oxygen. Eukaryotic cells contain two types of intracellular SOD : cytosolic, dimeric copper/zinc- containing enzyme (CuZnSOD) and mitochondrial, tetrameric manganese-containing enzyme (MnSOD). The purpose of this study is to evaluate the time-dependent gene expression of MnSOD and CuZnSOD in the endotoxin-treated rats, and to compare with the manifestations of LPS-induced acute lung injury in rats. METHODS: Total RNA from rat lung was isolated using single step phenol extraction 0, 1, 2, 4, 6, 12, 18, 24 hours after E. coli endotoxin injection (n=3, respectively). RNA was separated by formaldehyde-containing 1.2% agarose gels elctrophoresis, transblotted, baked, prehybridized, and hybridized with 32P-labeled cDNA probes for rat MnSOD and CuZnSOD, which were kindly donated by Dr. Ho (Duke University, Durham, NC, USA). The probes were labeled by nick translation. Blots were washed and autoradiography were quantitated using laser densitometry. Equivalent amounts of total RNA/gel were assessed by monitoring 285 and 185 rRNA. RESULTS: Endotoxin caused a rise in steady-state MnSOD mRNA levels by 4h with peak mRNA accumulation by 6h. Continued MnSOD mRNA expression was observed at 12h. CuZnSOD mRNA expression was observed from 1h to 24h with peak levels by 18h. CONCLUSION: These results suggest that SOD palys an important defensive role in the endotoxin-induced acute lung injury in rats.