Label-free Detection for a DNA Methylation Assay Using Raman Spectroscopy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>DNA methylation has been suggested as a biomarker for early cancer detection and treatment. Varieties of technologies for detecting DNA methylation have been developed, but they are not sufficiently sensitive for use in diagnostic devices. The aim of this study was to determine the suitability of Raman spectroscopy for label-free detection of methylated DNA.</p><p><b>METHODS</b>The methylated promoter regions of cancer-related genes cadherin 1 (CDH1) and retinoic acid receptor beta (RARB) served as target DNA sequences. Based on bisulfite conversion, oligonucleotides of methylated or nonmethylated probes and targets were synthesized for the DNA methylation assay. Principal component analysis with linear discriminant analysis (PCA-DA) was used to discriminate the hybridization between probes and targets (methylated probe and methylated target or nonmethylated probe and nonmethylated target) of CDH1 and RARB from nonhybridization between the probe and targets (methylated probe and nonmethylated target or nonmethylated probe and methylated target).</p><p><b>RESULTS</b>This study revealed that the CDH1 and RARB oligo sets and their hybridization data could be classified using PCA-DA. The classification results for CDH1 methylated probe + CDH1 methylated target versus CDH1 methylated probe + CDH1 unmethylated target showed sensitivity, specificity, and error rates of 92%, 100%, and 8%, respectively. The classification results for the RARB methylated probe + RARB methylated target versus RARB methylated probe + RARB unmethylated target showed sensitivity, specificity, and error rates of 92%, 93%, and 11%, respectively.</p><p><b>CONCLUSIONS</b>Label-free detection of DNA methylation could be achieved using Raman spectroscopy with discriminant analysis.</p>

Loculated Tuberculous Pleural Effusion: Easily Identifiable and Clinically Useful Predictor of Positive Mycobacterial Culture from Pleural Fluid / 결핵및호흡기질환

BACKGROUND: Isolation of M. tuberculosis (MTB) is required in cases of Tuberculous pleural effusion (TBPE) for confirming diagnosis and successful therapy based on drug sensitivity test. Several studies have focused on predictors of MTB culture positivity in TBPE. However, the clinical role of loculated TBPE as a predictor of MTB cultivation from TBPE remains unclear. The aim of this study was to examine possible predictors including loculation of TBPE of MTB culture positivity in TBPE. METHODS: We retrospectively examined associations between clinical, radiological, microbiological, and laboratory characteristics and positive MTB culture from TBPE to determine a potent predictor of culture positivity. RESULTS: From January 2011 to August 2015, 232 patients with TBPE were identified. Of these, 219 were finally analyzed. Among them, 69 (31.5%) were culture positive for MTB in TBPE and 86 (39.3%) had loculated TBPE. In multivariate logistic regression analysis, the loculation of TBPE was independently associated with culture positivity for MTB in TBPE (adjusted odds ratio [OR], 40.062; 95% confidence interval [CI], 9.355–171.556; p<0.001). In contrast, the lymphocyte percentage of TBPE (adjusted OR, 0.934; 95% CI, 0.899–0.971; p=0.001) was inversely associated with culture positivity for MTB in TBPE. CONCLUSION: In clinical practice, identification of loculation in TBPE is easy, reliable to measure, not uncommon and may be helpful to predict the possibility of positive mycobacterial culture.

Rocuronium Bromide Inhibits Inflammation and Pain by Suppressing Nitric Oxide Production and Enhancing Prostaglandin E2 Synthesis in Endothelial Cells / 대한배뇨장애요실금학회지

PURPOSE: Rocuronium bromide is a nondepolarizing neuromuscular blocking drug and has been used as an adjunct for relaxation or paralysis of the skeletal muscles, facilitation of endotracheal intubation, and improving surgical conditions during general anesthesia. However, intravenous injection of rocuronium bromide induces injection pain or withdrawal movement. The exact mechanism of rocuronium bromide-induced injection pain or withdrawal movement is not yet understood. We investigated whether rocuronium bromide treatment is involved in the induction of inflammation and pain in vascular endothelial cells. METHODS: For this study, calf pulmonary artery endothelial (CPAE) cells were used, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Western blot, nitric oxide detection, and prostaglandin E2 immunoassay were conducted. RESULTS: Rocuronium bromide treatment inhibited endothelial nitric oxide synthase and suppressed nitric oxide production in CPAE cells. Rocuronium bromide activated cyclooxygenase-2, inducible nitric oxide synthase and increased prostaglandin E2 synthesis in CPAE cells. CONCLUSIONS: Rocuronium bromide induced inflammation and pain in CPAE cells. Suppressing nitric oxide production and enhancing prostaglandin E2 synthesis might be associated with rocuronium bromide-induced injection pain or withdrawal movement.

A Case of Pleural Paragonimiasis Confused with Tuberculous Pleurisy / 결핵및호흡기질환

Here, we report a case of pleural paragonimiasis that was confused with tuberculous pleurisy. A 38-year-old man complained of a mild febrile sensation and pleuritic chest pain. Radiologic findings showed right pleural effusion with pleural thickening and subpleural consolidation. Adenosine deaminase (ADA) activity in the pleural effusion was elevated (85.3 IU/L), whereas other examinations for tuberculosis were negative. At this time, the patient started empirical anti-tuberculous treatment. Despite 2 months of treatment, the pleural effusion persisted, and video-assisted thoracoscopic surgery was performed. Finally, the patient was diagnosed with pleural paragonimiasis based on the pathologic findings of chronic granulomatous inflammation containing Paragonimus eggs. This case suggested that pleural paragonimiasis should be considered when pleural effusion and elevated ADA levels are observed.

Increasing Recovery of Nontuberculous Mycobacteria from Respiratory Specimens over a 10-Year Period in a Tertiary Referral Hospital in South Korea / 결핵및호흡기질환

BACKGROUND: The number of patients with pulmonary disease caused by nontuberculous mycobacteria (NTM) has been increasing worldwide. The aim of this study was to evaluate long-term trends in the NTM recovery rate from respiratory specimens over a 10-year period in a tertiary referral hospital in South Korea. METHODS: We retrospectively reviewed the records of mycobacterial cultures of respiratory specimens at Samsung Medical Center from January 2001 to December 2011. RESULTS: During the study period, 32,841 respiratory specimens from 10,563 patients were found to be culture-positive for mycobacteria. These included 12,619 (38%) Mycobacterium tuberculosis and 20,222 (62%) NTM isolates. The proportion of NTM among all positive mycobacterial cultures increased from 43% (548/1,283) in 2001 to 70% (3,341/4,800) in 2011 (p<0.001, test for trend). The recovery rate of NTM isolates from acid-fast bacilli smear-positive specimens increased from 9% (38/417) in 2001 to 64% (1,284/1,997) in 2011 (p<0.001, test for trend). The proportion of positive liquid cultures was higher for NTM than for M. tuberculosis (p<0.001). The most frequently isolated NTM were Mycobacterium avium-intracellulare complex (53%) and Mycobacterium abscessus-massiliense complex (25%). CONCLUSION: The recovery rate of NTM from respiratory specimens in South Korea has increased steadily.

Normalization of Elevated CA 19-9 Level after Treatment in a Patient with the Nodular Bronchiectatic Form of Mycobacterium abscessus Lung Disease / 결핵및호흡기질환

Carbohydrate antigen 19-9 (CA 19-9) is a widely-used tumor marker in patients with pancreatic cancer. However, some patients with respiratory disease also exhibit elevated serum CA 19-9 levels. We report a case of normalization of elevated serum CA 19-9 levels after treatment of the nodular bronchiectatic form of Mycobacterium ab scessus lung disease. A 40-year-old man visited our hospital because of chronic cough and sputum. A computed tomography scan revealed severe bronchiectasis in the right upper and right middle lobes. Nontuberculous mycobacteria were repeatedly isolated and identified as M. abscessus. The serum CA 19-9 level was elevated to 142.35 U/mL (normal range, <37 U/mL). Surgical resection was performed because of failure of sputum conversion after antibiotic treatment. The serum CA 19-9 level returned to the normal range after surgery. This case suggested that serum CA 19-9 levels could be elevated in patients with the nodular bronchiectatic form of M. abscessus lung disease.

Nontuberculous Mycobacterial Lung Disease Caused by Mycobacterium lentiflavum in a Patient with Bronchiectasis / 결핵및호흡기질환

We report a rare case of lung disease caused by Mycobacterium lentiflavum in a previously healthy woman. A 54-year-old woman was referred to our hospital due to chronic cough and sputum. A computed tomography scan of the chest revealed bilateral bronchiectasis with bronchiolitis in the right middle lobe and the lingular division of the left upper lobe. Nontuberculous mycobacteria were isolated twice from three expectorated sputum specimens. All isolates were identified as M. lentiflavum by multilocus sequence analysis based on rpoB, hsp65, and 16S rRNA fragments. To the best of our knowledge, this is the first documented case of M. lentiflavum lung disease in an immunocompetent adult in Korea.