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Dive into the research topics where Sang Hag Lee is active.

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Featured researches published by Sang Hag Lee.


Annals of Otology, Rhinology, and Laryngology | 2002

Antimicrobial defensin peptides of the human nasal mucosa

Sang Hag Lee; Jung Eun Kim; Heung Man Lee; Hyun Ho Lim; Jong Ouck Choi

Defensins, a prominent group of antimicrobial peptides, are an important component of the innate immune response, particularly at mucosal surfaces that are vulnerable to colonization by potential pathogens. The present study was undertaken to investigate the expression of defensins in inferior turbinate mucosa of normal subjects and inferior turbinate mucosa and nasal polyps of patients with chronic sinusitis. Expression of β-defensin 1 and 2 and α-defensin 5 and 6 messenger RNAs (mRNAs) was investigated by reverse transcriptase–polymerase chain reaction, and their expression level was semiquantitatively evaluated by dot blot hybridization. Immunohistochemical analysis was used for detection of α-defensins 1, 2, and 3 in tissue sections. β-Defensin 1 mRNA was expressed in all tissue samples, at levels that did not differ significantly. β-Defensin 2 mRNA was detected in the turbinate mucosa and nasal polyps of patients with chronic sinusitis, but not in normal mucosa. Its expression level was significantly higher in nasal polyps than in turbinate mucosa. α-Defensin 5 and 6 mRNAs were not expressed in any tissues, but α-defensins 1, 2, and 3 were detected in all tissue samples obtained from patients with chronic sinusitis. These results suggest that β-defensin 1 may play a constitutive role in nasal defenses, whereas α-defensins 1, 2, and 3 and β-defensin 2 may be induced in response to local infection or inflammation.


International Journal of Pediatric Otorhinolaryngology | 2010

Volumetric study in the development of paranasal sinuses by CT imaging in Asian: A Pilot study

Il Ho Park; Jong Seok Song; Hyuk Soon Choi; Tae Hoon Kim; Seung Hoon; Sang Hag Lee; Heung Man Lee

BACKGROUND AND OBJECTIVES The volume of the air cavities in the paranasal sinuses is not only the simplest, but also the most important index for paranasal sinus evaluation. However, few volumetric studies have been performed in all age groups. The purpose of the current study was to outline the normal development of paranasal sinuses in all age groups, and to determine normal adult volumetric values by means of computed tomographic (CT) scan of paranasal sinus using volumetric procedures. MATERIALS AND METHODS A prospective volumetric CT study was conducted with 260 patients (520 sides) <25 years of age by means of three-dimensional reconstruction. RESULTS The frontal sinuses began to pneumatize at 2 years of age, exhibited a faster growth pattern between 6 and 19 years of age, and the mean volume after full growth was 3.46±0.78 cm(3). The maxillary sinuses were pneumatized at birth in all cases, exhibited a monomodal growth pattern increasing until 15 years of age, and the mean volume after full growth was 14.83±1.36 cm(3). The floor of the sinus was the same level as the floor of the nasal cavity was between 7 and 15 years of age. The ethmoid sinuses exhibited a faster initial tendency to increase until 7 years of age, were completed by 15-16 years of age, and the mean volume after full growth was 4.51±0.92 cm(3). The sphenoid sinuses exhibited a growth spurt between 6 and 10 years of age, were completed by 15 years of age, and the mean volume after full growth was 3.47±0.93 cm(3). CONCLUSION The results of this study are presented to provide the basis for an objective normal volume of sinus development and for studies involving diseases of the sinuses.


International Journal of Pediatric Otorhinolaryngology | 2003

Endoscopic removal of an intranasal ectopic tooth

Dae Hyung Kim; Jeong Min Kim; Sung Won Chae; Soon Jae Hwang; Sang Hag Lee; Heung Man Lee

Intranasal ectopic teeth are rare and ectopic eruption of teeth can occur in a variety of locations. Commonly seen in the palate and maxillary sinus, they have also been reported in the mandibular condyle, coronoid process, orbital and nasal cavities, and through the skin. With the advent of sinonasal endoscopy in the mid 1980s, and subsequent advances in surgical techniques, endoscopic management of intranasal lesions has become possible. In the current case study, we report a successful endoscopic removal of intranasal ectopic teeth located in the nasal cavity. The endoscopic surgical approach used in this case caused less morbidity than do the more common methods of removing an intranasal ectopic tooth.


Acta Oto-laryngologica | 2010

Validation study of portable device for the diagnosis of obstructive sleep apnea according to the new AASM scoring criteria: Watch-PAT 100

Ji Ho Choi; Eun Joong Kim; Yang Soo Kim; June Choi; Tae Hoon Kim; Soon Young Kwon; Heung Man Lee; Sang Hag Lee; Chol Shin; Seung Hoon Lee

Abstract Conclusion: Watch-PAT may provide an accurate and clinically effective portable monitoring method for the diagnosis of obstructive sleep apnea (OSA). Objective: This study was designed to assess the accuracy and clinical efficacy of a wrist-worn portable device (Watch-PAT 100) to diagnose OSA. Methods: Twenty-seven participants with suspected OSA underwent full polysomnography (PSG). Finally, 25 subjects successfully underwent portable monitoring using Watch-PAT after full PSG. The study population consisted of 21 males and 4 females, mean age 40.9 ± 11.2 years (range 21–59). Mean body mass index (BMI) was 26.2 ± 2.6 kg/m2 (range 21.2–32.3). All PSG were manually scored according to the new scoring manual of the American Academy of Sleep Medicine (2007) and the Watch-PAT data were analyzed by the automatic algorithm. Results: There was a high correlation of apnea-hypopnea index (AHI) (r = 0.94, p < 0.001) and lowest oxygen saturation (LSAT) (r = 0.90, p < 0.001) between the PSG and the Watch-PAT. A good agreement was also found between PSG AHI, PSG LSAT and PAT AHI, PAT LSAT, respectively. There was a significantly high concordance of the severity of AHI (Kendall tau-b = 0.897, p < 0.001) between the PSG and the Watch-PAT.


Laryngoscope | 2007

How does open-mouth breathing influence upper airway anatomy?

Seung Hoon Lee; Ji Ho Choi; Chol Shin; Heung Man Lee; Soon Young Kwon; Sang Hag Lee

Objectives/Hypothesis: Open‐mouth breathing during sleep may increase the severity of obstructive sleep apnea (OSA) and complicate nasal continuous positive airway pressure (CPAP) therapy in patients with OSA. The aim of this study was to assess the effect of open‐mouth breathing on upper airway anatomy using lateral cephalometry and fiberoptic nasopharyngoscopy.


Annals of Otology, Rhinology, and Laryngology | 2000

Olfactory Mucosal Findings in Patients with Persistent Anosmia after Endoscopic Sinus Surgery

Sang Hag Lee; Hyun Ho Lim; Hyo Jin Park; Heung Man Lee; Jong Ouck Choi

Sixty-three biopsy specimens were obtained from the olfactory region of 15 patients with persistent anosmia and 6 patients with normosmia after sinus surgery. Immunohistochemical examination of all specimens with microtubule-associated protein 5 (MAP5) antisera demonstrated olfactory epithelium in 11 of 18 specimens from normosmic patients and in 12 of 45 samples from anosmic patients. There was a significant difference in the proportion of specimens containing olfactory epithelium between the two groups of patients. In normosmic patients, most of the biopsy samples contained normal-appearing olfactory tissue. However, 2 main patterns of histologic findings were noted in the olfactory mucosa of anosmic patients. First, the olfactory receptor cells were remarkably decreased in number. Second, the orderly arrangement of cells characteristic of normal olfactory epithelium was lost, demonstrating a degenerative appearance. These data suggest that olfactory epithelium can be degenerated even in chronic sinusitis and thereafter extensively replaced with respiratory epithelium, resulting in increased sampling error. Moreover, an unimproved olfactory deficit after sinus surgery may be due to the abnormalities observed at the olfactory epithelium level.


Osteoarthritis and Cartilage | 2012

Synovial fluid CD34⁻ CD44⁺ CD90⁺ mesenchymal stem cell levels are associated with the severity of primary knee osteoarthritis.

Dae Hee Lee; Chung Hee Sonn; Sang-Min Han; Yun-Je Oh; Kee-Hyoung Lee; Sang Hag Lee

To the best of our knowledge, no reports have directly compared synovial fluid (SF)- and synovial membrane (SM)-derived mesenchymal stem cells (MSCs) from primary knee osteoarthritis patients in terms of MSC proportion, either immediately after isolation or during culture. Any possible correlation between SM- and SF-MSC purity and osteoarthritis severity, also remains unclear. We therefore assessed quantitative and phenotypic differences in MSCs isolated from SF and SM. We also evaluated the correlation between sample MSC purity, and disease severity, in patients with osteoarthritis. The main result of the current study was that the mean SF-MSC proportion at passage 0 was negatively correlated with Kellgren-Lawrence (KL) grade (r = -0.565, P = 0.002). In addition, KL grade was a only significant independent negative predictor of SF-MSC proportion at passage 0 (β = -0.356, P = 0.039). Conclusively, the proportion of SF-MSCs in fresh samples, evaluated at the single cell level, was inversely correlated with osteoarthritis severity.


Plastic and Reconstructive Surgery | 2002

Endoscopic endonasal reconstruction of blowout fractures of the medial orbital walls.

Heung Man Lee; Seung Kyu Han; Sung Won Chae; Soon Jae Hwang; Sang Hag Lee

&NA; High‐resolution endoscopes and the advent of endoscopic instruments for sinus surgery currently provide surgeons with excellent endonasal visualization and access to the medial orbital walls. The purpose of this study was to demonstrate the reduction of medial orbital wall fractures through an endonasal endoscopic approach that allows the repair of the medial orbital wall fractures without an external incision. This study was a retrospective analysis of 16 patients who underwent surgical repair of medial orbital wall fractures from March of 1997 to May of 1998. The 11 male and five female patients ranged in age from 16 to 54 years (mean, 30.5 years). These patients had undergone primary reduction of medial orbital wall fractures and were observed for at least 12 months after surgery. There were no intraoperative or postoperative complications. Fifteen of 16 patients showed a complete improvement of their symptoms. One patient showed persistent diplopia, which was well managed by prisms. Endoscopic reduction of medial orbital wall fracture using an endonasal approach seems to produce good results and definite cosmetic advantages. (Plast. Reconstr. Surg. 109: 872, 2002.)


Annals of Otology, Rhinology, and Laryngology | 2010

Obstructive sleep apnea syndrome: A child is not just a small adult

Ji Ho Choi; Eun Joong Kim; June Choi; Soon Young Kwon; Tae Hoon Kim; Sang Hag Lee; Heung Man Lee; Chol Shin; Seung Hoon Lee

Objectives Pediatric obstructive sleep apnea syndrome (OSAS), like adult OSAS, is characterized by intermittent upper airway collapse during sleep and is associated with anatomic and neuromuscular factors. However, the clinical manifestations, diagnostic criteria, and Polysomnographic findings of OSAS in children are likely to be different from those in adults. The purpose of this study was to identify the characteristics that distinguish the clinical manifestations and Polysomnographic findings of OSAS in children from those in adults. Methods The study population consisted of 34 children (mean age, 7.6 years; range, 4 to 16 years) with OSAS and 33 adults (mean age, 40.1 years; range, 18 to 58 years) with OSAS. We compared various clinical manifestations, such as body mass index, tonsil size, severity of symptoms and signs, and Polysomnographic data, between these groups. Results Obesity was more common among the adults, whereas tonsillar hypertrophy was more common among the children. There were significant differences between the groups in the severity of symptoms and signs, including witnessed apnea, daytime sleepiness, morning headache, memory reduction, and daytime fatigue. In the children with OSAS, slow-wave sleep was relatively well preserved, and respiratory events such as apnea and hypopnea occurred mainly during rapid eye movement sleep. Conclusions The clinical manifestations and Polysomnographic findings in children with OSAS differ from those in adults with OSAS.


Laryngoscope | 2009

Prognostic significance of vascular endothelial growth factor-C expression and lymphatic vessel density in supraglottic squamous cell carcinoma.

Seung Kuk Baek; Kwang Yoon Jung; Sang Hag Lee; Jeong Soo Woo; Soon Young Kwon; Eun Jae Chung; Tae Hoon Kim; Yang Seok Chae

Regional lymph node metastases are very common findings of supraglottic cancer. The mechanism of lymphatic metastasis is as yet unknown because there have been no specific markers that could definitely distinguish lymphatic vessels from blood vessels. The aim of this study is to identify the prognostic significance of vascular endothelial growth factor‐C (VEGF‐C) expression and lymphatic vessel density (LVD) in supraglottic cancer.

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