Publications by authors named "Choong Sik Lee"

Exposure to particulate matter (PM) has been linked with the severity of various diseases. To date, there is no study on the relationship between PM exposure and tendon healing. Open Achilles tenotomy of 20 rats was performed.

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A newly designed TEMPO-FRIPS reagent, 4-(2,2,6,6-tetramethylpiperidine-1-oxyl) methyl benzyl succinic acid N-hydroxysuccinimide ester or p-TEMPO-Bn-Sc-NHS, was synthesized to achieve single-step free radical-initiated peptide sequencing mass spectrometry (FRIPS MS) for a number of model peptides, including phosphopeptides. The p-TEMPO-Bn-Sc-NHS reagent was conjugated to target peptides, and the resulting peptides were subjected to collisional activation. The peptide backbone dissociation behaviors of the MS/MS and MS experiments were monitored in positive ion mode.

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Background/aims: Narrow band imaging provides an accurate diagnosis of colonic polyps. However, these diagnostic modalities are not used as standard endoscopic tools in most institutions. This study aims to investigate whether the chicken skin mucosa (CSM) surrounding the colon polyp yields additional information about colorectal polyps, including histological differentiation of neoplastic and non-neoplastic polyps, under conventional white light colonoscopy.

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Article Synopsis
  • Lung cancer can sometimes get better on its own, which is really rare but has happened in a few cases.
  • This story is about a 60-year-old man who had symptoms like coughing up blood and a mass in his lungs, which was thought to be cancer.
  • After treating his bronchitis with antibiotics, his tests showed that the cancer was gone and only inflammation was left, with no cancer returning for almost 5 years.
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Purpose: We evaluated the expression of autotaxin-lysophosphatidate signaling-related proteins and the clinical implications for metastatic breast cancer.

Methods: We constructed tissue microarrays (TMA) with 126 cases of metastatic breast cancer [31 (24.6%) bone metastases, 36 (28.

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To understand the anomalous collision-induced dissociation (CID) behavior of the proton-bound Hoogsteen base pair of cytosine (C) and guanine (G), C:H∙∙∙G, we investigated CID of a homologue series of proton-bound heterodimers of C, 1-methylcytosine, and 5-methylcytosine with G as a common base partner. The CID experiments were performed in an energy-resolved way (ER-CID) under both multiple and near-single collision conditions. The relative stabilities of the protonated complexes examined by ER-CID suggested that the proton-bound complexes produced by electrospray ionization in this study are proton-bound Hoogsteen base pairs.

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Objectives: High-risk human papillomavirus (hrHPV) is known to be a representative cancer-causing agent in the genital and head and neck regions. Many studies have detected hrHPV DNA in nonsmall cell lung carcinoma. However, hrHPV-etiologic correlation in nonsmall cell lung carcinoma remains unclear.

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Aim: Cluster of differentiation 24 (CD24) is known to be a putative marker of stem cell and tumor metastasis. This study aimed to verify the clinicopathological value of CD24 expression in colorectal adenocarcinoma (CRAC).

Materials And Methods: A total of seven whole-tissue sections of malignant polyps including the sequence non-neoplastic colorectal tissue-adenoma-CRAC, 48 adenomas and 161 CRACs arranged as tissue microarray were examined by immunohistochemistry for CD24 protein expression.

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Background: Testing for epidermal growth factor receptor (EGFR) mutation is an important process in the therapeutic plan of patients with lung cancer. Recently, MassARRAY, based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, has been shown to be a useful method for somatic mutation analysis with pyrosequencing and peptide nucleic acid clamping (PNAc).

Methods: A total of 107 tissues and 67 cytological samples, which were confirmed to have lung adenocarcinoma at nine hospitals in Korea, were collected.

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Paratracheal air cysts are a rare entity in which cystic formation occurs adjacent to the trachea. Most patients with paratracheal air cysts are asymptomatic, and the cysts are detected incidentally on chest radiograph or computed tomography (CT) scan. Most symptomatic patients complain of pulmonary symptoms or repeated respiratory infection.

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Somatic mutation in the tyrosine kinase domain of epidermal growth factor receptor (EGFR) is a decisive factor for the therapeutic response to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in lung adenocarcinoma. The stability of mutant EGFR is maintained by various regulators, including heat shock protein 90 (Hsp90). The C terminus of Hsc70-interacting protein (CHIP) is a Hsp70/Hsp90 co-chaperone and exhibits E3 ubiquitin ligase activity.

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The efficacy of EGFR-tyrosine kinase inhibitors (TKIs) is significantly limited by various resistance mechanisms to those drugs. The resistance to EGFR-TKI is largely divided by two classes; acquired resistance after EGFR-TKI treatment, and primary resistance marked by cancer cell's dependence on other oncogene, such as KRAS. YAP has emerged as critical oncogene in conferring drug resistance against targeted therapy.

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Spontaneous regression (SR) of cancer is defined as a complete or partial, temporary or permanent disappearance of all or at least some relevant parameters of malignant disease with inadequate or no treatment. SR of cancer is an extremely rare phenomenon. We report a case of a 67-year-old man who experienced SR of non-small-cell lung cancer (NSCLC), which progressed after fifth-line chemotherapy and regressed after chemotherapy ceased.

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Background: Although KRAS shows high concordance between primary and metastatic colorectal cancers, recent studies have reported discordance and intra-tumoral heterogeneity. To evaluate KRAS concordance between primary colorectal cancers and recurrent tumors after radical resection, we performed this study.

Methods: Between January 2007 and August 2013, among patients underwent radical resection for primary colorectal cancers and tissue sampling of recurred tumors including resection or biopsy, 74 patients whose both primary and recurred tumor tissues were available for KRAS analysis were enrolled.

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Background: The importance of sensitive methods for the detection of epidermal growth factor receptor (EGFR) mutation is emphasized. The aim of this study is to perform comparative and concordance analyses of direct sequencing, pyrosequencing and peptide nucleic acid (PNA) clamping for detecting EGFR gene mutations using archived tissue and cytology specimens.

Methods: Samples from a total of 112 cases, which were diagnosed with adenocarcinoma of the lung at nine hospitals in Korea were collected.

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Although pulmonary artery angiosarcoma is rare, it can be misdiagnosed as pulmonary embolism because of its similar clinical and diagnostic features. The diagnosis is often delayed and the misdiagnosis brings unnecessary treatment. Because we made a wrong diagnosis of pulmonary artery angiosarcoma as an acute pulmonary embolism, we did thrombolytic therapy which could be dangerous to the patient.

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Atypical adenomatous hyperplasia (AAH) has been considered to be a precursor lesion of bronchioloalveolar carcinoma (BAC) and pulmonary adenocarcinoma. It usually coexists with BAC and/or an adenocarcinoma. Chest computed tomography reveals multiple well-defined nodules with ground-glass opacity.

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The anti-inflammatory action of silver nanoparticles (NPs) has been reported in a murine model of asthma in a previous study. But more specific mechanisms of silver NPs in an attenuation of allergic airway inflammation have not yet been established. Vascular and mucous changes are believed to contribute largely in pathophysiology in asthma.

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Lung cancer, the leading cause of cancer-related death, still lacks reliable biomarkers. Apurinic/apyrimidinic endonuclease 1/Ref-1 is a multifunctional protein involved in the base excision repair of DNA damaged by oxidative stress or alkylating compounds, as well as in the regulation of multiple transcription factors. To validate apurinic/apyrimidinic endonuclease 1/Ref-1 as a biomarker for prediction of lung cancer recurrence, we studied 42 patients who received curative resection and mediastinal lymph node dissection for stage I non-small-cell lung cancer.

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Dual specificity phosphatase 6 (DUSP6) is a member of the MAP kinase phophatase family. DUSP6 inactivates extracellular signal-regulated kinase (ERK), belonging to the MAP kinase family, and can act in tumor suppressive pathways. The aim of this study was to investigate associations of DUSP6 expression with expression of ERK and Ki-67 and with clinicopathological parameters in lung adenocarcinoma and squamous cell carcinoma.

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Introduction: The tyrosine kinase Met receptor regulates a complex array of cellular behaviors known collectively as invasive growth. Although essential for normal development and wound repair, this pathway is frequently deregulated in tumors to promote their growth, motility, and invasion. Accordingly, Met is overexpressed in a variety of human tumors, and this aberrant expression correlates with a poor patient prognosis.

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The use of silver in the past demonstrated the certain antimicrobial activity, though this has been replaced by other treatments. However, nanotechnology has provided a way of producing pure silver nanoparticles, and it shows cytoprotective activities and possible pro-healing properties. But, the mechanism of silver nanoparticles remains unknown.

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