Hye Kyeong Park

Clinical characteristics of health care-associated pneumonia in a Korean teaching hospital.

BACKGROUND Health care-associated pneumonia (HCAP) has been proposed as a new category of respiratory infection. ATS/IDSA guidelines state that all patients with HCAP should receive empirical therapy directed at multidrug-resistant pathogens. However, recent data from other countries have reported a different picture of HCAP. METHODS We conducted a retrospective observational study of patients with HCAP and CAP who were hospitalized through the emergency department in January-December 2008 at Samsung Medical Center, Seoul, Korea, and compared clinical characteristics, severity, distribution of pathogen, and outcomes. RESULTS In total, 345 patients hospitalized with pneumonia were eligible, 182 (52.8%) with HCAP and 163 (47.2%) with CAP. Patients with HCAP had greater comorbidity and higher Pneumonia Severity Index (PSI) score (P < 0.001). Although Streptococcus pneumoniae was the most frequently isolated pathogen in HCAP and CAP patients, the occurrence of potentially drug-resistant pathogens (29.3% vs. 13.0%; P = 0.044) and inappropriate initial antimicrobial treatment (24.6% vs. 8.7%; P = 0.032) were significantly higher in HCAP patients. Patients with HCAP had a longer duration of hospital stay (13 [8-18] vs. 8 [6-12] days; P < 0.001), and higher in-hospital mortality (19.2% vs. 7.4%; P = 0.001). In a multiple logistic regression analysis, however, in-hospital mortality was independently associated with higher PSI class (OR 2.82, 95% CI 1.19-6.70) and ICU admission (OR 15.37, 95% CI 3.58-66.05). CONCLUSIONS Severity of illness, rather than type of pneumonia, was the main predicting factor for in-hospital mortality among patients with pneumonia hospitalized through the emergency department.

Occult nodal metastasis in patients with non-small cell lung cancer at clinical stage IA by PET/CT

Background and objective:  The introduction of 18F‐FDG PET/CT has enhanced the diagnostic accuracy of nodal staging for non‐small cell lung cancer (NSCLC). We analysed risk factors for occult nodal metastasis in patients with clinical stage IA NSCLC as determined by 18F‐FDG PET/CT.

L‐ascorbic acid represses constitutive activation of NF‐κB and COX‐2 expression in human acute myeloid leukemia, HL‐60

There is increasing evidence that l‐ascorbic acid (LAA) is selectively toxic to some types of cancer cells at pharmacological concentrations, functioning as a pro‐oxidant rather than as an anti‐oxidant. However, the molecular mechanisms by which LAA initiates cellular signaling leading to cell death are still unclear. In an effort to gain insight into these mechanisms, the effects of LAA on eukaryotic transcription nuclear factor NF‐κB and cyclooxygenase‐2 (COX‐2) expression were investigated. In the present study, LAA suppressed DNA binding activity of NF‐κB, composed of a p65/p50 heterodimer, through inhibition of degradation of inhibitory κB‐α (IκB‐α) and prevention of nuclear translocation of p65. The inhibitory effect of LAA on NF‐κB activity was dependent upon glutathione levels in HL‐60 cells, as well as generation of H2O2 but not superoxide anion. LAA also downregulated the expression of COX‐2, which has a NF‐κB binding site on its promoter, through repressing NF‐κB DNA binding activity. Moreover, cotreatment of 1 μM arsenic trioxide (As2O3) with various concentrations of LAA enhanced an LAA‐induced repression of NF‐κB activity and COX‐2 expression. In conclusion, our data suggest that LAA exerts its anti‐tumor activity through downregulation of NF‐κB activity and COX‐2 expression, and these inhibitory effects can be enhanced by co‐treatment with As2O3.

Clinical Characteristics and Treatment Outcomes of Mycobacterium kansasii Lung Disease in Korea.

Purpose While Mycobacterium kansasii is a common cause of nontuberculous mycobacterial (NTM) lung disease in many developed countries, M. kansasii is infrequently isolated in Korea. We investigated the clinical and radiological features and treatment outcomes of M. kansasii lung disease in Korea retrospectively. Materials and Methods We identified 41 patients with M. kansasii lung disease who met the diagnostic criteria for NTM lung disease in two tertiary referral hospitals in Seoul, Korea, between January 1998 and December 2007. Results Their median age was 63 years [interquartile range (IQR) 51-75 years] and 33 (81%) were men. Twenty-three patients (56%) were smokers and 13 patients (32%) had previous pulmonary tuberculosis. The most common radiographic findings were nodules (n = 22, 54%) and consolidation (n = 22, 54%). Cavitation was present in 13 patients (32%). Thirty-one patients (76%) were treated with isoniazid, rifampin, and ethambutol. The median treatment duration was 16 months (IQR 9-18 months). The negative conversion rate after 12 months of treatment was 95%. Conclusion Clinicians should be aware of the various radiographic manifestations of M. kansasii lung disease. With appropriate treatment, these patients have a good prognosis.

Factors predicting outcome following airway stenting for post-tuberculosis tracheobronchial stenosis.

Background and objective:  Silicone airway stents are used to widen narrowed airways in patients with post‐tuberculosis tracheobronchial stenosis (PTTS). After mechanical stabilization, stents can be removed from the majority of patients leaving restored airway patency. However, in a significant minority re‐stenosis develops post‐sten removal thus necessitating surgical intervention or long‐term stenting. In this study, we sought to establish prognostic factors for successful airway intervention in PTTS.

The role of pleural fluid MAGE RT‐nested PCR in the diagnosis of malignant pleural effusion

Background:  Melanoma antigen (MAGE) genes are expressed in tumor cells, the testis and the placenta. The purpose of this prospective study was to investigate the sensitivity, specificity, and accuracy of the carcinoembryonic antigen (CEA), MAGE reverse transcriptase‐nested polymerase chain reaction (RT‐nested PCR), and cytology of pleural fluid in the diagnosis of malignant pleural effusion.