Severe sepsis or septic shock is characterized by an excessive inflammatory response to infectious pathogens. Acute respiratory distress syndrome (ARDS) is a devastating complication of severe sepsis, from which patients have high mortality. Advances in treatment modalities including lung protective ventilation, prone positioning, use of neuromuscular blockade, and extracorporeal membrane oxygenation, have improved the outcome over recent decades, nevertheless, the mortality rate still remains high. Timely treatment of underlying sepsis and early identification of patients at risk of ARDS can help to decrease its development. In addition, further studies are needed regarding pathogenesis and novel therapies in order to show promising future treatments of sepsis-induced ARDS.

Lung cancer causes the most cancer deaths in Korea. Although the smoking rate has begun to decrease, the prevalence of lung cancer is still increasing. We reviewed the national lung cancer registry data and the data published about lung cancer in Korea. In 2012, the crude incidence rate of lung cancer was 43.9 per 100,000. The age-standardized mortality rate of lung cancer was 19.8 per 100,000. The 5-year relative survival rate for lung cancer was 11.3% from 1993 to 1995 and increased to 21.9% in the period from 2008 to 2012. Lung cancer occurring in never-smokers was estimated to increase in Korea. Adenocarcinoma is steadily increasing in both women and men and has replaced squamous cell carcinoma as the most common type of lung cancer in Korea. In patients with adenocarcinoma, the frequency of EGFR mutations was 43% (range, 20%-56%), while that of the EMK4-ALK gene was less than 5%.

In late March of 2009, an outbreak of influenza in Mexico, was eventually identified as H1N1 influenza A. In June 2009, the World Health Organization raised a pandemic alert to the highest level. More than 214 countries have reported confirmed cases of pandemic H1N1 influenza A. In Korea, the first case of pandemic influenza A/H1N1 infection was reported on May 2, 2009. Between May 2009 and August 2010, 750,000 cases of pandemic influenza A/H1N1 were confirmed by laboratory test. The H1N1-related death toll was estimated to reach 252 individuals. Almost one billion cases of influenza occurs globally every year, resulting in 300,000 to 500,000 deaths. Influenza vaccination induces virus-neutralizing antibodies, mainly against hemagglutinin, which provide protection from invading virus. New quadrivalent inactivated influenza vaccine generates similar immune responses against the three influenza strains contained in two types of trivalent vaccines and superior responses against the additional B strain.

Nontuberculous mycobacteria (NTM) are emerging pathogens that affect both immunocompromised and immunocompetent patients. The incidence and prevalence of NTM lung disease are increasing worldwide and rapidly becoming a major public health problem. For the diagnosis of NTM lung disease, patients suspected to have NTM lung disease are required to meet all clinical and microbiologic criteria. The development of molecular methods allows the characterization of new species and NTM identification at a subspecies level. Even after the identification of NTM species from respiratory specimens, clinicians should consider the clinical significance of such findings. Besides the limited options, treatment is lengthy and varies by species, and therefore a challenge. Treatment may be complicated by potential toxicity with discouraging outcomes. The decision to start treatment for NTM lung disease is not easy and requires careful individualized analysis of risks and benefits. Clinicians should be alert to those unique aspects of NTM lung disease concerning diagnosis with advanced molecular methods and treatment with limited options. Current recommendations and recent advances for diagnosis and treatment of NTM lung disease are summarized in this article.

Background: Lung cancer is the most common cause of cancer related death. Alterations in gene sequence, structure, and expression have an important role in the pathogenesis of lung cancer. Fusion genes and alternative splicing of cancer-related genes have the potential to be oncogenic. In the current study, we performed RNA-sequencing (RNA-seq) to investigate potential fusion genes and alternative splicing in non-small cell lung cancer. Methods: RNA was isolated from lung tissues obtained from 86 subjects with lung cancer. The RNA samples from lung cancer and normal tissues were processed with RNA-seq using the HiSeq 2000 system. Fusion genes were evaluated using Defuse and ChimeraScan. Candidate fusion transcripts were validated by Sanger sequencing. Alternative splicing was analyzed using multivariate analysis of transcript sequencing and validated using quantitative real time polymerase chain reaction. Results: RNA-seq data identified oncogenic fusion genes EML4-ALK and SLC34A2-ROS1 in three of 86 normal-cancer paired samples. Nine distinct fusion transcripts were selected using DeFuse and ChimeraScan; of which, four fusion transcripts were validated by Sanger sequencing. In 33 squamous cell carcinoma, 29 tumor specific skipped exon events and six mutually exclusive exon events were identified. ITGB4 and PYCR1 were top genes that showed significant tumor specific splice variants. Conclusion: In conclusion, RNA-seq data identified novel potential fusion transcripts and splice variants. Further evaluation of their functional significance in the pathogenesis of lung cancer is required.

Background: Chronic obstructive pulmonary disease (COPD) is sometimes complicated with pneumonia, but little is known about the risk factors that promote the development of pneumonia in COPD. These risk factors were evaluated in the present study. Methods: The data of 324 patients with COPD from a prospective multi-center observational cohort with obstructive lung disease were evaluated retrospectively. To identify risk factors for the development of pneumonia in COPD, the clinical and radiological data at enrollment and the time to the first episode of pneumonia were analyzed by Cox proportional hazard analysis. Results: The median follow-up time was 1,099 days and 28 patients (8.6%) developed pneumonia. The Cox analysis showed that post-bronchodilator forced expiratory volume in one second ($FEV_1$, % of predicted) and the computed tomography (CT) emphysema extent (inspiratory V950) were independent risk factors for the development of pneumonia (post-bronchodilator $FEV_1$: hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.94-1.00; p=0.048 and inspiratory V950: HR, 1.04; 95% CI, 1.01-1.07; p=0.01). Conclusion: Emphysema severity measured by CT and post-bronchodilator $FEV_1$ are important risk factors for the development of pneumonia in COPD.

We present a rare case of critically compromised airway secondary to a massively dilated sequestered colon conduit after several revision surgeries. A 71-year-old male patient had several operations after the diagnosis of gastric cancer. After initial treatment of pneumonia in the pulmonology department, he was transferred to the surgery department for feeding jejunostomy because of recurrent aspiration. However, he had respiratory failure requiring mechanical ventilation. The chest computed tomography (CT) scan showed pneumonic consolidation at both lower lungs and massive dilatation of the substernal interposed colon compressing the trachea. The dilated interposed colon was originated from the right colon, which was sequestered after the recent esophageal reconstruction with left colon interposition resulting blind pouch at both ends. It was treated with CT-guided pigtail catheter drainage via right supraclavicular route, which was left in place for 2 weeks, and then removed. The patient remained well clinically, and was discharged home.

Nocardia species are aerobic, gram-positive pathogens found worldwide in soil. Nocardia is considered an opportunistic pathogen, and its infection mostly occurs in immunocompromised patients. We report a case of Nocardia farcinica induced mediastinitis and pneumonia that occurred in a 64-year-old male patient who had no significant medical history except for hypertension. He visited another hospital with a complaint of dyspnea and left chest wall pain. The symptoms arose 7 days ago without any trauma and they worsened. A mediastinal mass was found on computed tomography scan. After being transferred to our hospital for further evaluation, he was diagnosed with mediastinitis and pneumonia. As N. farcinica was found to be the causative organism by 16S rRNA sequencing, proper antibiotic therapy including trimethoprim/sulfamethoxazole was initiated immediately. After this, the patient improved and he was discharged. If an infection has a disseminating course, nocardiosis cannot be excluded even in immunocompetent patients. Once the diagnosis is established, prompt antibiotic therapy should be performed based on the severity.