Research Center for Resistan Cells

Medicine, South Korea

Research Center for Resistan Cells

Medicine, South Korea
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Jang C.H.,Chonnam National University | Jang C.H.,Research Center for Resistan Cells | Cho Y.B.,Chonnam National University | Yeo M.G.,Sungkyunkwan University | Kim G.H.,Sungkyunkwan University
Macromolecular Bioscience | Year: 2013

Two different composite scaffolds, solid-freeform-fabricated PCL/β-TCP supplemented with and without collagen nanofibers are fabricated. These scaffolds are evaluated whether a combination of collagen nanofibers with PCL/β-TCP can promote osteogenesis in a mastoid obliteration. To assess the effects of the cellular activities of osteoblast-like-cells (MG63), SEM images and MTT assays are conducted. Experimental mastoid obliteration is performed using guinea pigs that are divided group A (PCL/β-TCP/collagen-nanofiber scaffold) and group B (PCL/β-TCP scaffold). The results reveal that PCL/β-TCP/collagen scaffold provide much broader cell attachment sites than PCL/β-TCP scaffold. The μ-CT and fluorescent microscopy results reveal that the acceleration of early new bone formation within the pores and scaffold itself at week 4 post-operation is more effective in group A. In addition, based on the results of the histological and μ-CT at 12 weeks post-surgery, the effective regeneration of bone in the PCL/β-TCP/collagen scaffold is appeared. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Choi C.H.,Research Center for Resistan Cells | Jang C.H.,Chonnam National University | Jang C.H.,Research Center for Resistan Cells | Cho Y.B.,Chonnam National University | And 3 more authors.
International Journal of Pediatric Otorhinolaryngology | Year: 2012

Objective: Oxytetracycline and ilomastat are inhibitors of matrix metalloproteinases (MMPs). Their efficacy in protecting against cochlear damage induced by the intratympanic instillation of lipopolysaccharide (LPS), as a means of inducing labyrinthitis, was investigated. Materials and methods: Experiments were performed in 21 young male guinea pigs. Intratympanic instillation of LPS was done in the control group (n= 7). Intratympanic instillation of oxytetracycline or ilomastat was done after LPS instillation in the experimental group. Measurements of auditory brainstem response (ABR) and cochlear blood flow (CBF) were performed. The organ of Corti was evaluated by field emission scanning electron microscopy (FE-SEM). The blood-labyrinth barrier (BLB) integrity was evaluated with Evans blue uptake. Gelatin zymography was used to assess the expression of active MMP-2 and MMP-9. Results: Ears treated with MMP inhibitors were significantly protected from hearing loss compared to the LPS group. In LPS group, there was a significant decrease of CBF. However, experimental group displayed a statistically significant recovery of CBF. FE-SEM revealed hair cell damage in the LPS-treated group, but hair cells presented a normal appearance in MMP inhibitors. The LPS group showed a marked increase of Evans blue extravasation in the cochlea. However, MMP inhibitors significantly reduced the BLB opening. Active MMP-9 was expressed in the LPS group. Treatment with MMP inhibitors attenuated active MMP-9 expression. Conclusion: The MMP inhibitors oxytetracycline and ilomastat protect from cochlear lateral wall damage caused by LPS-induced labyrinthitis. © 2012 Elsevier Ireland Ltd.


Jang C.H.,Chonnam National University | Jang C.H.,Research Center for Resistan Cells | Cho Y.B.,Chonnam National University | Kim J.S.,Chonnam National University | And 2 more authors.
Laryngoscope | Year: 2012

Objectives/Hypothesis: The study aimed to regenerate pneumatic air cells in guinea pig bulla using three-dimenisonal (3D) biocomposite scaffolds consisting of polycaprolactone/β-tricalcium phosphate (PCL/β-TCP). Study Design: Prospective controlled study in experimental animals. Methods: PCL/β-TCP composites were implanted into the bulla with mucosa preservation in group A (n = 10). PCL/β-TCP composites coated with collagen were implanted in group B (n = 10). After 12 weeks, the bullae were extracted and evaluated by micro-computed tomography (micro-CT) and were processed for histological analyses. Results: In group A, micro-CT showed a well-maintained honeycomb appearance of micropores without obstruction. Regeneration of the mucosa was noted inside the pores of the 3D scaffold. However, partial obstruction of the micropores with new bone formation was evident in group B. Conclusions: Group A showed more satisfactory mucosal regeneration into the micropores. Our results indicate that the 3D scaffold may be amenable for use during mastoidectomy. Further studies for gas exchange in the regenerated mucosa are necessary. © 2012 The American Laryngological, Rhinological and Otological Society, Inc.


Jang C.H.,Chonnam National University | Jang C.H.,Research Center for Resistan Cells | Cho Y.B.,Chonnam National University | Yeo M.,Sungkyunkwan University | And 4 more authors.
International Journal of Biological Macromolecules | Year: 2013

Chronic tympanic membrane (TM) perforation is one of the most common otology complications. Current surgical management of TM perforation includes myringoplasty and tympanoplasty. The purpose of this study was to evaluate the efficacy and feasibility of three dimensional (3D) porous collagen scaffolds with topically applied human umbilical cord serum (UCS) for the regeneration of chronic TM perforation in guinea pigs. To achieve this goal, we fabricated porous 3D collagen scaffolds (avg. strut diameter of 236. ±. 51. μm, avg. pore size of 382. ±. 67. μm, and a porosity of 96%) by using a 3 axis robot dispensing and low temperature plate systems. Guinea pigs were used in a model of chronic TM perforation. In the experimental group (. n=. 10), 3D collagen scaffold was placed on the perforation and topically applied of UCS every other day for a period of 8 days. The control group ears (. n=. 10) were treated with paper discs and phosphate buffered saline (PBS) only using the same regimen. Healing time, acoustic-mechanical properties, and morphological analysis were performed by otoendoscopy, auditory brainstem response (ABR), single-point laser Doppler vibrometer (LDV), optical coherence tomography (OCT), and light microscopic evaluation. The closure of the TM perforation was achieved in 100% of the experimental group vs. 43% of the control group, and this difference was statistically significant (. p=. 0.034). The ABR threshold at all frequencies of the experimental group was significantly recovered to the normal level compared to the control group. TM vibration velocity in the experimental group recovered similar to the normal control level. The difference is very small and they are not statistically significant below 1. kHz (. p=. 0.074). By OCT and light microscopic examination, regenerated TM of the experimental group showed thickened fibrous and mucosal layer. In contrast, the control group showed absence of fibrous layer like a dimeric TM. © 2013 Elsevier B.V.


Choi C.H.,Research Center for Resistan Cells | Pak S.C.,Charles Sturt University | Jang C.H.,Research Center for Resistan Cells | Jang C.H.,Chonnam National University
International Journal of Pediatric Otorhinolaryngology | Year: 2016

Background & objective: The effect of direct application of local lidocaine with epinephrine on the facial nerve (FN) has not been reported. The aim of this study is to assess the effects of 2% lidocaine with 1:100,000 epinephrine at clinically relevant concentrations in a rat FN model with respect to facial nerve blood flow (FNBF) and subsequent electrophysiological changes. Materials and methods: To assess the influence of drugs on FNBF and electrically evoked muscle action potential (EMAP), small pieces of gelfoam were soaked in PBS 100 μl (n = 5, control group), 50 μl (n = 5, treatment group A) and 100 μl (n = 5, group B) of 2% lidocaine with 1:100,000 epinephrine, and 50 μl (n = 5, group C) and 100 μl (n = 5, group D) of 2% lidocaine. After 5 min of stable recordings, we applied a 2% lidocaine with or without 1:100,000 epinephrine impregnated gelfoam over the main trunk of the facial nerve of rats for 30 min. After removing the applied gelfoam, FNBF and threshold of EMAP were measured separately in each group. Results: Compared to the control group, the treatment groups showed a significant reduction in FNBF in a dose-dependent manner. The maximal reductions in FNBF were observed in all treatment groups for a period after 10 min of the application. Synergistic reduction in FNBF was greater in groups A and B than in the lidocaine applied groups (C and D). The maximal increase in the EMAP threshold was observed immediately after the respective drug application in all groups. The greatest increase in the EMAP threshold was observed in group B. The increased EMAP threshold returned to the baseline value within 120 min in groups A and C. Conclusion: From these results, it can be considered that the topical application of lidocaine with epinephrine caused reduction in FNBF and elevation of EMAP threshold. These acute reductions in FNBF and elevations in the EMAP threshold were restored in a time-dependent manner. © 2016 Elsevier Ireland Ltd.


Jang C.H.,Chonnam National University | Jang C.H.,Research Center for Resistan Cells | Cho Y.B.,Chonnam National University | Choi C.H.,Research Center for Resistan Cells
International Journal of Pediatric Otorhinolaryngology | Year: 2012

Background and objective: Many pharmacological agents have shown successful results in experimental crush injury of the peripheral nerve. To date, therapeutic effect of ginkgo biloba extract (GBE) on the peripheral nerve crush injury of rats has been rarely reported, moreover, neuroprotective effect on the facial nerve crush injury has not been reported. Materials and methods: Prospective functional recovery, using a vibrissae movement and electrophysiological analysis of recovery 4 weeks after the facial nerve crush in adult rats, and comparison with randomized intraperitoneal injection of either GBE or control phosphate buffered saline. Results: Relative to the control group (26 days post operation), administration of GBE significantly accelerated the recovery of vibrissae orientation to 11.7 days post the operation. A significant functional recovery was observed by postoperative 2nd week in the experimental group. The recovery of threshold and conduction velocity, postoperative 4th week in the experimental group, showed statistically significant difference compared to that of the control group. Conclusion: From this result, intraperitoneal injection of GBE has been found effective in promoting the regeneration of the nerve in an experimental facial nerve crush rat model. Further studies, including morphological and molecular analyses, are necessary to clarify the mechanisms of GBE on the facial nerve crush. © 2012 Elsevier Ireland Ltd.


Jang C.H.,Chonnam National University | Jang C.H.,Research Center for Resistan Cells | Cho Y.B.,Chonnam National University | Choi C.H.,Research Center for Resistan Cells
International Journal of Pediatric Otorhinolaryngology | Year: 2012

Objectives: Many materials and surface preparations have been developed to resist the formation of biofilm. Ion-bombarded silicone tympanostomy tube was introduced to resist both staphylococcal and pseudomonal biofilm formation. To date, there are no reports that have evaluated the use of ion-bombarded tympanostomy tubes against the ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) biofilm formation. The purpose of this study is to evaluate the ion-bombarded tympanostomy tube for CRPA biofilm resistance. Methods: Commercial ion-bombarded tympanostomy tubes and simple silicone tympanostomy tubes were processed for an evaluation of the CRPA biofilm formation in vitro. Results: The ion-bombarded tubes showed no resistance to CRPA adhesion and biofilm formation. Thick and dense conglomeration was less formed in the ion-bombarded tympanostomy tubes, compared to that of the simple silicone tube. Conclusion: The preventive effect against the CRPA biofilm formation of the ion-bombarded silicone tympanostomy tube was not observed. Our result suggests that only the surface modification by an ion bombardment is not enough to resist CRPA biofilm formation. © 2012 Elsevier Ireland Ltd.


Jang C.H.,Chonnam National University | Jang C.H.,Research Center for Resistan Cells | Jo S.Y.,Chonnam National University | Cho Y.B.,Chonnam National University
Acta Oto-Laryngologica | Year: 2013

Conclusion: Matrix removal by a non-suction technique with intraoperative dexamethasone injection is a safe and effective management modality, regardless of fistula size. Objective: Our goal was to evaluate the outcome of hearing treated by non-suction technique with intraoperative dexamethasone injection. Methods: This was a retrospective chart review of 720 mastoidectomy cases for cholesteatoma, performed at our tertiary otolaryngologic care centers between 2005 and 2012. A total of 17 patients with a unilateral labyrinthine fistula were encountered. Results: There was no recurrent cholesteatoma in any of the patients. In all cases, the matrix was removed by intraoperative dexamethasone injection with a bimanual non-suction technique, regardless of the fistula size. None of the patients showed deteriorated bone conduction (BC). Averaged BC was unchanged (n = 13) or improved (n = 4) in all patients and did not decrease by 10 dB more in any patient. The mean threshold of postoperative BC was significantly improved compared with preoperative mean threshold. Fistulae on the preoperative CT scans ranged from 1.41 to 7.12 mm and averaged 2.89 mm. There was no correlation between the fistula size and the postoperative BC level. Even with a large fistula, postoperative hearing preservation was possible with one-stage matrix removal. © 2013 Informa Healthcare.


PubMed | Chonnam National University, Research Center for Resistan Cells and Charles Sturt University
Type: | Journal: International journal of pediatric otorhinolaryngology | Year: 2016

The effect of direct application of local lidocaine with epinephrine on the facial nerve (FN) has not been reported. The aim of this study is to assess the effects of 2% lidocaine with 1:100,000 epinephrine at clinically relevant concentrations in a rat FN model with respect to facial nerve blood flow (FNBF) and subsequent electrophysiological changes.To assess the influence of drugs on FNBF and electrically evoked muscle action potential (EMAP), small pieces of gelfoam were soaked in PBS 100l (n=5, control group), 50l (n=5, treatment group A) and 100l (n=5, group B) of 2% lidocaine with 1:100,000 epinephrine, and 50l (n=5, group C) and 100l (n=5, group D) of 2% lidocaine. After 5min of stable recordings, we applied a 2% lidocaine with or without 1:100,000 epinephrine impregnated gelfoam over the main trunk of the facial nerve of rats for 30min. After removing the applied gelfoam, FNBF and threshold of EMAP were measured separately in each group.Compared to the control group, the treatment groups showed a significant reduction in FNBF in a dose-dependent manner. The maximal reductions in FNBF were observed in all treatment groups for a period after 10min of the application. Synergistic reduction in FNBF was greater in groups A and B than in the lidocaine applied groups (C and D). The maximal increase in the EMAP threshold was observed immediately after the respective drug application in all groups. The greatest increase in the EMAP threshold was observed in group B. The increased EMAP threshold returned to the baseline value within 120min in groups A and C.From these results, it can be considered that the topical application of lidocaine with epinephrine caused reduction in FNBF and elevation of EMAP threshold. These acute reductions in FNBF and elevations in the EMAP threshold were restored in a time-dependent manner.


Lim S.-C.,Research Center for Resistan Cells | Lim S.-C.,Chosun University | Parajuli K.R.,Research Center for Resistan Cells | Duong H.-Q.,Research Center for Resistan Cells | And 4 more authors.
International Journal of Oncology | Year: 2014

Despite conflicting results, there is evidence to suggest an inverse link between total body cholesterol levels and the risk of certain malignancies. Based on previous reports, this phenomenon appears to vary with cancer site, and, in particular, more consistent data on inverse relations was reported in the risk of gastric cancer. In the current study, the effect of cholesterol on gastric cancer cell viability was examined using an in vitro cell culture system. Addition of cholesterol in culture medium resulted in reduced viability and clonogenicity of SNU601, SNU638 and SNU216 gastric cancer cells by induction of both autophagic and apoptotic death. Transient inactivation of ERK1/2 was linked to reduction of cholesterol-mediated cell viability, and tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2/DR5) was also involved in cell death signaling. In conclusion, these results imply that cholesterol can act as a signal regulator to modulate cell viability and that proper cellular cholesterol levels may be advantageous to suppress growth of gastric carcinomas.

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