Yoon Jung Oh

Expression of peroxiredoxin and thioredoxin in human lung cancer and paired normal lung

Background:  Peroxiredoxins (Prxs) have been implicated in regulating many cellular processes including cell proliferation, differentiation and apoptosis. However, the pathophysiological significance of Prx proteins, especially in lung disease, has not been defined. Therefore, the authors investigated the distribution and expression of various Prx isoforms in lung cancer and compared this with normal lung from human and mouse.

Low expression of Bax predicts poor prognosis in resected non-small cell lung cancer patients with non-squamous histology.

Objective The present study evaluated the prognostic significance of apoptosis-related proteins p53, Bax and galectin-3 in patients with non-small cell lung cancer (NSCLC) treated with surgical resection. Methods We investigated the expression of these proteins and their association with clinicopathologic characteristics including disease-free survival (DFS) and overall survival (OS) in 205 NSCLC patients who underwent surgical resection (Stage I, 97; II, 46; IIIA, 45; IIIB, 17) using immunohistochemistry. Eighty-eight patients (43%) received adjuvant treatment (chemotherapy: 8, radiotherapy: 24, both: 56). Results High expressions of Bax, p53 and galectin-3 were observed in 48 (23%), 81 (40%) and 105 (51%) patients, respectively. Low expression of Bax was significantly associated with male gender, squamous cell histology and low expression of galectin-3. Five-year DFS and OS of total patients were 37 and 46%, respectively. High expressions of p53 and galectin-3 were not associated with poor DFS or OS, and no significant correlation existed between low expression of Bax and outcome of patients. However, in patients with non-squamous histology (108 patients), low expression of Bax was a significant independent predictor of poor DFS (P = 0.017) and OS (P = 0.037). In addition, in patients with Stage II or III disease, low expression of Bax significantly correlated with poor DFS (P = 0.004). It was also the most significant independent poor prognostic factor second only to a large primary tumor size in Stage II or III patients with non-squamous histology. Conclusions Low expression of Bax was significantly associated with poor prognosis in resected NSCLC patients with non-squamous histology.

A Case of Streptococcus suis Infection Causing Pneumonia with Empyema in Korea.

Streptococcus suis causes meningitis and sepsis in pigs, but human infection has increased over the past few years in those who are exposed to pigs or raw pork. Most cases have occurred in Southeast Asia, but only two cases have been reported in South Korea, presenting with arthritis and meningitis. Here, we report a rare case of S. suis infection, a 60-year-old sailor, who visited the emergency room presenting septicemia, pneumonia with empyema and meningitis, showed full recovery; however, neurologic sequale of severe cognitive dysfunction was present after the usage of antibiotics and percutaneous drainage. S. suis was isolated from blood and pleural fluid and the strain was susceptible to penicillin and vancomycin. Increased awareness of S. suis infection and prevention are warranted.

A case of fulminant community-acquired Acinetobacter baumannii pneumonia in Korea

Acinetobacter baumannii (AB) is a common pathogen found in patients with hospital-acquired pneumonia all over the world. Community-acquired AB pneumonia, however, is very rare and has seldom been reported in Asia-Pacific countries. Community-acquired AB pneumonia has a fulminant course and is associated with a higher mortality than hospital-acquired AB pneumonia. In Korea, no case of fatal community-acquired AB pneumonia has been reported to date. Here, we describe the first fatal case of fulminant community-acquired AB pneumonia in Korea.

Selectively Decreased Expression of Peroxiredoxins Induced by Silica in Pulmonary Epithelial Cells

Background/Aims Peroxiredoxin (Prx) belongs to a ubiquitous family of antioxidant enzymes that regulates many cellular processes through intracellular oxidative signal transduction pathways. Silica-induced lung damage involves reactive oxygen species (ROS) that trigger subsequent toxic effects and inflammatory responses in alveolar epithelial cells resulting in fibrosis. Therefore, we investigated the role of Prx in the development of lung oxidant injury caused by silicosis, and determined the implication of ROS in that process. Methods Lung epithelial cell lines A549 and WI26 were treated with 1% silica for 0, 24, or 48 hours, following pretreatment of the A549 cells with N-acetyl-L-cysteine and diphenylene iodonium and no pretreatment of the WI26 cells. We transfected an HA-ubiquitin construct into the A549 cell line and then analyzed the cells via Western blotting and co-immunoprecipitation. Results Silica treatment induced cell death in the A549 lung epithelial cell line and selectively degraded Prx I without impairing protein synthesis in the A549 cells, even when the ROS effect was blocked chemically by N-acetyl-L-cysteine. A co-immunoprecipitation study revealed that Prx I did not undergo ubiquitination. Conclusions Silica treatment induces a decrease of Prx I expression in lung epithelial cell lines regardless of the presence of ROS. The silica-induced degradation of Prx does not involve the ubiquitin-proteasomal pathway.

Acute Hemodynamic Effects of Recruitment Maneuvers in Patients With Acute Respiratory Distress Syndrome

Background: The recruitment maneuver (RM) in acute respiratory distress syndrome (ARDS) can cause hemodynamic derangement. We evaluated circulatory and cardiac changes during RMs. Methods: We performed sustained inflation (SI) with a pressure of 40 cm H2O for 30 seconds as an RM on 22 patients with ARDS. Blood pressure (BP) and heart rate were recorded immediately before, every 10 seconds during, and 30 seconds after the RM. Ventricular dimensions were obtained simultaneously using M-mode echocardiography, and tissue Doppler imaging was performed on the left ventricular wall. Results: Mean, systolic, and diastolic BP decreased at 20 and 30 seconds during 30-second RMs (mean BP: 92 ± 12 at baseline to 83 ± 18 mm Hg at the end of the RM, P < .05) and subsequently recovered. Heart rate decreased at 10 and 20 seconds during the RM, and tended to increase afterward. Both ventricular dimensions decreased significantly during the RM. The left ventricular ejection fraction and peak velocity of the left ventricle during systole remained stable. The fractional changes in mean BP and left ventricular end-diastolic dimension during the RMs were correlated significantly with each other (rs = 0.59). Static compliance of the respiratory system (Crs) was lower in patients with mean BP change ≥15% than in patients in whom the change was <15% (P < .05). Conclusions: A transient decrease in mean BP was observed during the RM, and its degree was correlated with the preload decrease, while cardiac contractility was maintained.

Assessment of Right Ventricular Function in Patients with Chronic Obstructive Pulmonary Disease Using Echocardiographic Tei Index

Background : Advanced chronic obstructive pulmonary disease is characterized by progressive pulmonary hypertension leading to right heart dysfunction, which plays a Important role in clinical evaluation but remains difficult and challenging to quantify. The noninvasive doppler echocardiographic value referred to as the Tei index has been suggested as a simple, reproducible and reliable parameter of the right ventricular function. The purpose of this was to assess the right ventricular function in patients with chronic obstructive pulmonary disease using the Tei index and to evaluate its relationship with the pulmonary functional status. Methods : The study population comprised of 26 patients with chronic obstructive pulmonary disease and 10 normal control subjects. The Tei index was obtained by dividing the sum of the isovolumetric contraction and the relaxation times by the ejection time using a pulsed-wave doppler. It was compared with the other available Doppler echocardiographic parameters of systolic or diastolic function and with the pulmonary function of the patients. Results : The Tei indices of the patients with COPD were significantly higher than those of normal subjects( vs. , p vs. , p vs. , p vs. , p vs. msec, p (r=-0.46, p) compared to those with a mild and moderate ventilatory dysfunction. The tei indices showed an inverse correlation to with the ejection time (r=-0.469), the isovolumetric contraction time/ejection time(r=0.453), the isovolumetric relaxation time/ejection time(r=0.896) and the preejection period/ejection time(r=0.480). Conclusion : The tei index appeared to be a useful noninvasive means of evaluating the right ventricular function. It revealed a significant correlation with the pulmonary function in patients with COPD.