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Articles by C. H Lee
Total Records ( 11 ) for C. H Lee
  C. H Lee , J. H Mo , I. J Choi , H. J Lee , B. S Seo , D. Y Kim , P. Y Yun , I. Y Yoon , H Won Lee and J. W. Kim
 

Objectives  To evaluate retrospectively the efficacy of the mandibular advancement device (MAD) in Korean patients with obstructive sleep apnea (OSA) in terms of severity and to evaluate prognostic factors deciding the success of MAD application.

Design  Retrospective analysis.

Setting  Academic tertiary referral center.

Patients  Of 142 patients who underwent MAD application for OSA management, 50 (46 men and 4 women; mean [SD] age, 50.2 [9.8] years) were included from March 2005 through August 2007.

Intervention  Full-overnight polysomnography was performed before and at least 3 months after intraoral MAD application in 50 patients. Questionnaires for sleep quality, Epworth sleepiness scale, and cephalometry were also studied.

Main Outcome Measures  Treatment results were evaluated and prognostic factors deciding success of MAD application were assessed.

Results  The mean (SD) apnea-hypopnea index (AHI) decreased significantly (P < .001) from 36.6 (18.9) to 12.3 (11.4). The success rate, defined by an AHI of lower than 20 and a 50% decrease in AHI, were 74% (37 of 50 patients). Even patients who were not categorized into the success group had a decreased AHI. The success rates of patients with mild, moderate, and severe OSA were 43% (3 of 7), 82% (22 of 27), and 75% (12 of 16), respectively, and a higher success rate in patients with severe OSA showed that MAD could be applied even in patients with severe OSA. The duration of apnea and hypopnea, percentage of patients with snoring, and the Pittsburgh Sleep Quality Index were improved significantly after treatment. Epworth sleepiness scale scores and lowest oxygen saturation did not change significantly. An analysis of prognostic factors did not reveal any significant difference between the success and nonsuccess groups.

Conclusions  The application of MAD significantly improved nocturnal respiratory function and sleep quality in patients with OSA, even in patients with severe OSA. In patients with OSA, MAD can be used as a good alternative treatment modality regardless of severity because it is noninvasive, easy to manufacture, and has good treatment results.

  C. H Lee , J. W Kim , H. J Lee , P. Y Yun , D. Y Kim , B. S Seo , I. Y Yoon and J. H. Mo
 

Objective  To quantitatively evaluate the effects of the mandibular advancement device (MAD) on changes in the upper respiratory tract during sleep using sleep videofluoroscopy (SVF) in patients with obstructive sleep apnea (OSA).

Design  Retrospective analysis.

Setting  Academic tertiary referral center.

Patients  Seventy-six patients (68 men and 8 women) who were treated with the MAD for OSA were included from September 1, 2005, through August 31, 2008.

Intervention  All patients underwent nocturnal polysomnography and SVF before and at least 3 months after receipt of the custom-made MAD. Sleep videofluoroscopy was performed before and after sleep induction and was analyzed during 3 states of awakeness, normoxygenation sleep, and desaturation sleep.

Main Outcome Measures  Changes in the length of the soft palate, retropalatal space, retrolingual space, and angle of mouth opening were evaluated during sleep events with or without the MAD.

Results  Without the MAD, the length of the soft palate and the angle of mouth opening increased during sleep events, especially in desaturation sleep, compared with the awake state. The retropalatal space and retrolingual space became much narrower during sleep compared with the awake state. The MAD had marked effects on the length of the soft palate, retropalatal space, retrolingual space, and angle of mouth opening. The retropalatal space and retrolingual space were widened, and the length of the soft palate was decreased. The MAD kept the mouth closed.

Conclusions  Sleep videofluoroscopy showed dynamic upper airway changes in patients with OSA, and the MAD exerted multiple effects on the size and configuration of the airway. Sleep videofluoroscopy demonstrated the mechanism of action of the MAD in patients with OSA. The MAD increased the retropalatal and retrolingual spaces and decreased the length of the soft palate and the angle of mouth opening, resulting in improvement of OSA.

  H Chang , H. J Lee , J. H Mo , C. H Lee and J. W. Kim
 

Objective  To evaluate the relationship between findings via osteomeatal unit computed tomography (OMU CT) of the olfactory cleft and olfactory function in patients with chronic rhinosinusitis (CRS).

Design  Retrospective review of medical records.

Setting  Referral center.

Participants  Two hundred ten patients with CRS who underwent OMU CT and olfactory function tests were included in this study.

Main Outcome Measures  All the paranasal sinuses were graded via the Lund-Mackay scoring system. The olfactory cleft was graded on a scale of 0 to 4 according to its opacification. Olfactory function was evaluated by the butanol threshold test (BTT) and the 16-odor identification test (OIT).

Results  The radiologic grade of the olfactory cleft was more significantly correlated with olfactory function than the grades of the paranasal sinuses. In patients without allergy, the BTT and OIT scores were inversely correlated with the CT score of the olfactory cleft. However, in patients with allergy, only the BTT score had a negative correlation with the CT score of the olfactory cleft, whereas the OIT score did not. The OIT score showed a significant negative correlation with the opacification of the olfactory cleft in the mild and moderate CRS group only, whereas the BTT score showed a significant negative correlation in all stages of CRS.

Conclusions  The opacification of the olfactory cleft had a negative correlation with the olfactory function scores in patients with CRS. The olfactory cleft findings on OMU CT may give some clues to the olfactory function in patients with CRS.

  B. S Seo , H. J Lee , J. H Mo , C. H Lee , C. S Rhee and J. W. Kim
 

Objective  To analyze the efficacy of treating postviral olfactory loss with glucocorticoids, Ginkgo biloba, and mometasone furoate nasal spray.

Design  Randomized trial.

Setting  Academic research.

Patients  Seventy-one patients who were diagnosed as having postviral olfactory loss.

Main Outcome Measures  All patients underwent olfactory function tests, including the butanol threshold test (BTT) and the cross-cultural smell identification test (CCSIT), and follow-up tests were performed 4 weeks later. In the interim, 28 patients were treated with prednisolone for 2 weeks (monotherapy), and the other 43 patients were treated with prednisolone for 2 weeks plus G biloba for 4 weeks (combination therapy). All patients used mometasone nasal spray twice daily for 4 weeks.

Results  Scores on the BTT and CCSIT significantly increased after treatment in both groups (P < .001 for both). The mean (SD) BTT score changes were 1.4 (2.2) in the monotherapy group and 2.2 (2.9) in the combination therapy group (P = .22). The mean (SD) CCSIT score changes were 0.9 (1.7) in the monotherapy group and 1.9 (2.7) in the combination therapy group (P = .11). On the BTT, the treatment response (defined as a score increase of ≥3) rates were 32% (9 of 28) in the monotherapy group and 37% (16 of 43) in the combination therapy group (P = .66), and the odds ratio was 1.25 (95% confidence interval, 0.46-3.42). On the CCSIT, the treatment response rates were 14% (4 of 28) in the monotherapy group and 33% (14 of 43) in the combination therapy group (P = .08), and the odds ratio was 2.89 (95% confidence interval, 0.84-9.97).

Conclusions  Olfactory function in patients with postviral olfactory loss was significantly improved by both treatment modalities. Although the treatment response was not statistically different between the monotherapy group and the combination therapy group, the addition of G biloba showed a tendency of greater efficacy in the treatment of postviral olfactory loss.

  W. T Liao , C. L Yu , C. C. E Lan , C. H Lee , C. H Chang , L. W Chang , H. L You and H. S. Yu
 

Bowen's disease (BD), a carcinoma in situ of the skin, has been identified as an early lesion in arsenic carcinogenesis. Patients with arsenic-induced Bowen's disease (As-BD) showed both cutaneous and systemic immune dysfunctions. We set out to evaluate the interactions between keratinocytes and lymphocytes in the context of As-BD carcinogenesis. Our results showed that As-BD lesions demonstrated a significant dermal CD4+ cell, an essential regulator of proper tumor immunity, undergoing apoptosis. In addition, it was found that the As-BD patients have lower percentage of peripheral CD4+ cells as compared with control subjects. However, the CD4+ cells from As-BD patients were less susceptible to arsenic-induced apoptosis, due to reduced tumor necrosis factor receptor 1 expression. Interestingly, arsenic was found to induce Fas expression on CD4+ cells and increase the soluble Fas ligand (sFasL) production from keratinocytes. This sFasL-containing keratinocyte supernatant was able to induce comparable CD4+ cell apoptosis for both patients and controls. Using immunofluorescent staining, increased FasL was observed in keratinocytes of As-BD lesions and Fas was expressed among infiltrating CD4+ cells. Our findings suggested that systemically, the percentage of CD4+ cells was decreased in the peripheral blood of As-BD patients. These residual CD4+ cells were less susceptible to arsenic-induced apoptosis. However, once infiltrated into the As-BD lesions, the selective CD4+ cell apoptosis might be mediated by FasL from keratinocytes. This additional tumor-anti-immune phenomenon present in the cutaneous environment provides a reasonable explanation for frequent occurrence of arsenic cancers in the skin.

  Y. M Yang , S Lee , C. W Nam , J. H Ha , M Jayaraman , D. N Dhanasekaran , C. H Lee , M. K Kwak and S. G. Kim
 

Bortezomib is a proteasome inhibitor approved for anticancer therapy. However, variable sensitivity of tumor cells exists in this therapy probably due to differences in the expression of proteasome subunits. G12/13 serves modulators or signal transducers in diverse pathways. This study investigated whether cancer cells display differential sensitivity to bortezomib with reference to G12/13 expression, and if so, whether G12/13 affects the expression of proteasome subunits and their activities. Bortezomib treatment exhibited greater sensitivities in Huh7 and SNU886 cells (epithelial type) than SK-Hep1 and SNU449 cells (mesenchymal type) that exhibited higher levels of G12/13. Overexpression of an active mutant of G12 (G12QL) or G13 (G13QL) diminished the ability of bortezomib to induce cytotoxicity in Huh7 cells. Moreover, transfection with the minigene that disturbs G protein-coupled receptor-G protein coupling (CT12 or CT13) increased it in SK-Hep1 cells. Consistently, MiaPaCa2 cells transfected with CT12 or CT13 exhibited a greater sensitivity to bortezomib. Evidence of G12/13’s antagonism on the anticancer effect of bortezomib was verified in the reversal by G12QL or G13QL of the minigenes’ enhancement of cytotoxity. Real-time polymerase chain reaction assay enabled us to identify PSMB5, multicatalytic endopeptidase complex-like-1, and proteasome activator subunit-1 repression by CT12 or CT13. Furthermore, G12/13 inhibition enhanced the ability of bortezomib to repress PSMB5, as shown by immunoblotting and proteasome activity assay. Moreover, this inhibitory effect on PSMB5 was attenuated by G12QL or G13QL. In conclusion, the inhibition of G12/13 activities may enhance the anticancer effect of bortezomib through PSMB5 repression, providing insight into the G12/13 pathway for the regulation of proteasomal activity.

  C. H Lee , S. M Khoo , B. C Tai , E. Y Chong , C Lau , Y Than , D. X Shi , L. C Lee , A Kailasam , A. F Low , S. G Teo and H. C. Tan
  Background:

We investigated the prevalence and predictors of obstructive sleep apnea (OSA) in patients admitted to the hospital for acute myocardial infarction and whether OSA has any association with microvascular perfusion after primary percutaneous coronary intervention (PCI).

Methods:

Recruited patients were scheduled to undergo an overnight sleep study between 2 and 5 days after primary PCI. An apnea-hypopnea index (AHI) of ≥ 15 was considered diagnostic of OSA. Impaired microvascular perfusion after primary PCI was defined as an ST-segment resolution of ≤ 70%, myocardial blush grade 0 or 1, or a corrected Thrombolysis in Myocardial Infarction (TIMI) [antegrade flow scale] frame count > 28.

Results:

Sleep study was performed in 120 patients and completed in 105 patients (study cohort, mean age 53 ± 10 years, male 98%) with uncomplicated myocardial infarction. An AHI was ≥ 15 in 69 patients (OSA-positive), giving a prevalence of 65.7%. Diabetes mellitus was found to be a significant risk factor for OSA (odds ratio, 2.86; 95% confidence interval, 1.06 to 8.24; p = 0.033). There were no differences between OSA-positive and OSA-negative groups with regard to the percentage of patients with ≤ 70% ST-segment resolution (73% vs 64%, respectively; p = 0.411), myocardial blush grade 0 or 1 (39.1% vs 38.9%, respectively; p = 1.000), or corrected TIMI frame count > 28 (21.7% vs 25.0%, respectively; p = 0.807).

Conclusions:

We found a high prevalence of previously undiagnosed OSA in patients admitted with acute myocardial infarction. Diabetes mellitus was independently associated with OSA. No evidence indicated that OSA is associated with impaired microvascular perfusion after primary PCI.

  C. H Chou , C. H Lee and Y. H. Chen
 

The main steps for designing an automatic document classification system include feature extraction and classification. In this article a method to improve feature extraction is proposed. In this method, genetic algorithm was applied to determine the threshold values of four criteria for extracting the representative keywords for each class. The purpose of these four threshold values is to extract as few representative keywords as possible. This keyword extraction method was combined with two classification algorithms, vector space model and support vector machine, for examining the performance of the proposed classification system under various extracting conditions.

  C. C Lan , Y. K Wu , C. H Lee , Y. C Huang , C. Y Huang , Y. H Tsai , S. F Huang and T. C. Y. Tsao
  Objective

The sensitivity of cytologic examination of pleural effusions is variable and not predictive of prognosis. Survivin is an inhibitor of apoptosis that may be a novel diagnostic/prognostic marker of cancers. This study aimed to determine the diagnostic and prognostic value of measuring survivin mRNA levels in pleural effusions.

Methods

Eighty-eight consecutive pleural effusion samples were examined for both cytology and survivin mRNA level. The accuracy of diagnosis and the correlation between survivin mRNA level and survival in malignant pleural effusion (MPE) were determined. Pleural effusions were divided into three groups: Group I, malignancy-associated (n = 44); Group II, inflammatory (n = 27); and Group III, transudative (n = 17).

Results

Survivin mRNA levels in Group I (1.03 ± 0.61, range 0–2.96) were significantly higher than those in Groups II (0.45 ± 0.69, range 0–3.30) and III (0.08 ± 0.22, range 0–0.71) (P < 0.001). Survivin mRNA level was significantly higher in MPE than in non-MPE. The cut-off value for survivin mRNA levels in pleural effusions was 0.074 for the diagnosis of malignancies, with sensitivity, specificity, and positive and negative predictive values of 96%, 45%, 45% and 96%, respectively. Survivin mRNA level in pleural effusions of cancer patients significantly correlated with poor survival.

Conclusions

Survivin mRNA level is significantly higher in MPEs. Over-expression of survivin mRNA correlates with poor prognosis in cancer patients.

  C. C Tsai , C. L Lin , T. L Wang , A. C Chou , M. Y Chou , C. H Lee , I W Peng , J. H Liao , Y. T Chen and C. Y. Pan
 

Vesicle recycling is vital for maintaining membrane homeostasis and neurotransmitter release. Multiple pathways for retrieving vesicles fused to the plasma membrane have been reported in neuroendocrine cells. Dynasore, a dynamin GTPase inhibitor, has been shown to specifically inhibit endocytosis and vesicle recycling in nerve terminals. To characterize its effects in modulating vesicle recycling and repetitive exocytosis, changes in the whole cell membrane capacitance of bovine chromaffin cells were recorded in the perforated-patch configuration. Constitutive endocytosis was blocked by dynasore treatment, as shown by an increase in membrane capacitance. The membrane capacitance was increased during strong depolarizations and declined within 30 s to a value lower than the prestimulus level. The amplitude, but not the time constant, of the rapid exponential decay was significantly decreased by dynasore treatment. Although the maximal increase in capacitance induced by stimulation was significantly increased by dynasore treatment, the intercepts at time 0 of the curve fitted to the decay phase were all ~110% of the membrane capacitance before stimulation, regardless of the dynasore concentration used. Membrane depolarization caused clathrin aggregation and F-actin continuity disruption at the cell boundary, whereas dynasore treatment induced clathrin aggregation without affecting F-actin continuity. The number of invagination pits on the surface of the plasma membrane determined using atomic force microscopy was increased and the pore was wider in dynasore-treated cells. Our data indicate that dynamin-mediated endocytosis is the main pathway responsible for rapid compensatory endocytosis.

  C. H Lee and P. A. Coulombe
 

Keratins, the largest subgroup of intermediate filament (IF) proteins, form a network of 10-nm filaments built from type I/II heterodimers in epithelial cells. A major function of keratin IFs is to protect epithelial cells from mechanical stress. Like filamentous actin, keratin IFs must be cross-linked in vitro to achieve the high level of mechanical resilience characteristic of live cells. Keratins 5 and 14 (K5 and K14), the main pairing occurring in the basal progenitor layer of epidermis and related epithelia, can readily self-organize into large filament bundles in vitro and in vivo. Here, we show that filament self-organization is mediated by multivalent interactions involving distinct regions in K5 and K14 proteins. Self-organization is determined independently of polymerization into 10-nm filaments, but involves specific type I–type II keratin complementarity. We propose that self-organization is a key determinant of the structural support function of keratin IFs in vivo.

 
 
 
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