• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.5
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• pp.379-389
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• 2005

Obstructive adenitis of the salivary gland following salivary stone or infectious disease of the gland and surrounding tissues is a common disease. It is often difficult to decide whether to perform total excision of the gland or to consider conservative treatment. The present study was designed to investigate histological, histochemical changes of submandibular gland after ligating the excretory duct for identifying the results of gland duct obstruction. A group of 40 rat of Sprague-Dawley weighing about $200{\sim}220gm$ were used in the present study. 30 rats had ligation of the main excretory ducts of submandibular glands just at the exit from the glands. For controls, 10 rats had a sham operation without duct ligation. They were inducted into euthanagia state by intracardial Ketamine injection in 1, 2, 3, 5, 7, 14, 21, 28, 35 and 42 days after the ligation. In each ligation period, 3 animals were used for ligation and one animal was for control. The submandibular glands were dissected out at sacrifice and stained with H&E, PAS, mucicarmine stain and histological examination were carried out under the light microscope. After examination and comparison of all specimens, the results were as follows: 1. In the features of H&E stain, acini disappeared by degrees after the ligation of the excretary duct and interstitial cells were displaced into fibrous connective tissue. Salivary gland had been atrophied with enlarging ducts and proliferating ductal cells. 2. Through total experimental period, a lot of vessels were observed and the atrophy of serous gland was severer than that of mucous gland. 3. The deep portion of submandibular glands showed severe degeneration rather than superficial portion of them after the ligation. 4. The changes which had enlarged ducts and proliferating ductal cells were observed in entire gland and more prominent in serous gland than mucous gland after the ligation. 5. Although PAS and mucicarmine reactions were decreased gradually after the ligation with the lapse of time, since 2 to 3 weeks they were strong positive reactions on entire gland, especially on duct-like structure. So, we can suggest that salivary gland will be atrophied but, survived acini will be redistributed around the ducts.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.868-876
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• 2000

Objective : Parkinsonian rat models have generally been characterized by unilateral destruction of both the nigrostriatal pathway and the mesolimbic pathway using the neurotoxin 6-hydroxydopamine. The induction of contraversive turning by apomorphine in these models is thought to reflect the stimulation of supersensitive dopamine D2 receptor or receptor-mediated mechanisms in denervated neostriatum. The present study was undertaken to investigate the expression of dopamine D2 receptor in denervated striatum according to modalities of apomorphine(dopamine agonist) treatment after creating a hemiparkinsonian rat model in which there is 6-hydroxydopamine induced destruction of the unilateral dopaminergic nigrostriatal pathway. Methods : After making complete lesion in left side substantia nigra pars compacta(SNpc) by stereotactic injection of 6-hydroxydopamine into medial and lateral areas of SNpc, and confirming successful animal model by apomorphine induced contraversive turning behavior without recovery and complete destruction of ipsilateral SNpc with tyrosine hydroxylase immunostaining in 7th day after operation, 15 rats of parkinsonian model were studied with or without administration of apomorphine at varying doses and durations. According to the modalities of apomorphine treatment for 4 days, these rats were divided into 3 groups, as not-treated group, intermittently treated group and constantly treated group. For investigating the extent of the expression of dopamine D2 receptor in denervated striatum, immunohistochemical staining by dopamine D2 receptor antibody and Western blot were performed. Results : In the D2 receptor antibody immunohistochemical staining, the mean number of positive stained neurons was highest in not-treated group($20.5{\pm}1.14$) of 3 groups. In constantly treated group, the mean number of positive stained neurons was less($3.9{\pm}1.79$) than intermittently treated group(p<0.05). The Western blotting with the D2 receptor antibody revealed that expression of receptors was also highest in not-treated group and less in constantiy treated group than intermittently treated group. Conclusion : Dopamine D2 receptors in denervated striatum of parkinsonian rat models, which were not treated with apomorphine, revealed to be most highly expressed. And, according to doses and durations of apomorphine administration, desensitization of the receptor was more apt to develop with constant treatment than intermittent treatment. In clinical setting, the authors believe that, in long-term treated parkinsonian patients, desensitization of dopamine receptors due to chronic dopaminergic stimulation seems to be partially related to mechanisms of drug tolerance.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.396-400
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• 2005

A 13-year old, female Maltese dog was presented due to a five-month history of episodic syncope. A diagnosis of sick sinus syndrome (SSS) with mitral valve endocardiosis (MVE) was made based on history takings, physical and cardiac examination, complete blood count (CBC), serum chemistry profiles, radiography, electrocardiography (ECG), atropine response test, hormonal assay, and echocardiography. In this case, SSS was definitely diagnosed by evaluation of ECG recording following atropine administration. Clinical signs were improved with medical management of theophylline (THEOLAN, KunWha Pharm, Seoul, Korea, 20 mg/kg, PO, BID). After 10 more month survival, the dog, died of respiratory distress and shock during the operation of abdominal mass removal in local animal hospital. Unfortunately, we were not able to perform necropsy after death due to owner's decline. This case demonstrates that theophylline can be used in management oF dog with SSS.

• Journal of Chest Surgery
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• v.49 no.4
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• pp.232-241
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• 2016

Background: Paraplegia is a devastating complication following operations on the thoracoabdominal aorta. We investigated whether histidine-tryptophan-ketoglutarate (HTK) solution could reduce the extent of ischemia/reperfusion (IR) spinal cord injuries in a rat model using a direct delivery method. Methods: Twenty-four Sprague-Dawley male rats were randomly divided into four groups. The sham group (n=6) underwent a sham operation, the IR group (n=6) underwent only an aortic occlusion, the saline infusion group (saline group, n=6) underwent an aortic occlusion and direct infusion of cold saline into the occluded aortic segment, and the HTK infusion group (HTK group, n=6) underwent an aortic occlusion and direct infusion of cold HTK solution into the occluded aortic segment. An IR spinal cord injury was induced by transabdominal clamping of the aorta distally to the left renal artery and proximally to the aortic bifurcation for 60 minutes. A neurological evaluation of locomotor function was performed using the modified Tarlov score after 48 hours of reperfusion. The spinal cord was harvested for histopathological and immunohistochemical examinations. Results: The spinal cord IR model using direct drug delivery in rats was highly reproducible. The Tarlov score was 4.0 in the sham group, $1.17{\pm}0.75$ in the IR group, $1.33{\pm}1.03$ in the saline group, and $2.67{\pm}0.81$ in the HTK group (p=0.04). The histopathological analysis of the HTK group showed reduced neuronal cell death. Conclusion: Direct infusion of cold HTK solution into the occluded aortic segment may reduce the extent of spinal cord injuries in an IR model in rats.

• Progress in Medical Physics
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• v.16 no.2
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• pp.104-109
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• 2005

Photodynamic therapy (PDT) is one of the expectable current cure operation methods. Tumor tissue is treated by abundant oxygen in a body and generated singlet or free radical from exterior laser diode and photosensitizer. Current problem of PDT is the low penetration power of the light beam in a deep seated large tumor and solid tumor thus results in low treatment outcome. In the study, we tried to develop interstitial photodynamics therapy treatment to solve this problem. As the accurate determination of light dosimetry in biological tissue is one of the most important factors affecting the effectiveness of PDT, parameters used in this study are the optical property of biological tissue. Since biological tissues have large scattering coefficient to visible light the penetration depth of a biological tissue in visible light region is only $15\~20$ mm. We showed that it is possible to measure fluence rate and penetration depth within the biological tissues by Monte Carlo simulation very well. Based on the MC simulation study, the effectiveness of interstitial photodynamic therapy on tumor control in solid tumor was proved through in vivo animal experiment.

• Journal of Biomedical Engineering Research
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• v.23 no.3
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• pp.217-225
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• 2002

The implantable middle ear(IME) system, which has good sound quality. superior sound intelligibility and wide frequency characteristics. can resolve the sound distortion and ringing effect by sound feedback at high gain operation those are the major problems of conventional hearing aid. In this paper, we have manufactured the IME system using differential electromagnetic transducer(DET) and verified the performance of the system by carrying out vibration and animal implanting experiment. The DET was manufactured using micro-machining technology and vibration experiment of the transducer was performed to inspect whether the transducer could vibrate in accordance with the applied sound signal or not. And the result of the loaded experiment using temporal bone sampled from cadaver showed that the transducer can drive the middle ear bone and transmit the signal to inner ear After the internal unit of IME system was implanted in a dog. the auditory brainstem response (ABR) test was carried out. The result of the test indicated the Proper behavior of the IME system in the living body From the results of the experiments, it is verified that the manufactured system ewll work well when it is applied to human and a basis of clinical experiment of IME system to real human hearing impaired was be arranged.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.223-228
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• 2002

We have developed a homemade particle inflow gun (PIG) system which has simple operation method, low price and high gene introduction efficiency into rice callus. Rice callus were inflowed with gold particles containing DNA of a plasmid, pIG121Hm, harboring intron GUS ($\beta$-glucuronidase) gene, NPTII gene and HPT gene. For optimal GUS transient expression, the effects of parameters on DNA delivery efficiency of the PIG system was investigated by scoring transient GUS expression. The highest number of blue spots was observed at 16 mM of spemidine and 1.5 M of calcium chloride, respectively. And the amount of gold particles required for the best GUD expression was 2 mg. Optimum GUS transient expression was observed at target distance of 12 cm and helium pressure of 3.5 bar (50 psi). Gene introduction efficiency of the PIG system was observed almost similar to that of the Biolistic Gun (Bio-Rad Company). Since PIG system is simple to operate and one doesn't need disposable accessaries, the PIG system can be easily applied to various replication experiments.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.2
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• pp.113-117
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• 2005

Background and Objective : Vocal fold augmentation by injectable material under direct visual control is an easy and simple operation. However, when autologous fat or bovine collagen is used, the resoiption creates a problem. And autologous fascia is debating about absorption now days. We previously reported on the one year results of injected autologous auricular cartilage for volumetric augmentation in paralyzed canine vocal cord. This study evaluates the long-term histomorphologic results of injected autologous auricular cartilage for the augmentation of the paralyzed canine vocal fold at two year. Material and Methods . A prospective trial of autologous cartilage augmentation of vocal cord in animal model. Three dogs were operated upon. A piece of auricular cartilage was harvested from the ear and minced into tiny chips with a scalpel. Fat was harvested from inguinal area and minced with a scalpel. The minced cartilage and fat-paste (0.2ml) was injected using a pressure syringe into the paralyzed thyroarytenoid muscle using direct laryngoscopy. Three animals were sacrificed at 2 years. Each subject underwent laryngectomy and serial coronal sections of paraffin blocks from the posterior vocal fold were made. Results There was no significant complication perioperatively and during follow-up. The injected cartilage which appeared to have lost viability existed in the vocalis muscles until 24 months. Fibrotic change was exhibited in the surrounding injected cartilage. Conclusion : The autologous auricular cartilage graft is well tolerated and may be very effective material for volumetric augmentation on paralyzed vocal cord.

• Journal of Periodontal and Implant Science
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• v.41 no.4
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• pp.176-184
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• 2011

Purpose: The final goal of regenerative periodontal therapy is to restore the structure and function of the periodontium destroyed or lost due to periodontitis. However, the role of periosteum in periodontal regeneration was relatively neglected while bone repair in the skeleton occurs as a result of a significant contribution from the periosteum. The aim of this study is to understand the histological characteristics of periosteum and compare the native periosteum with the repaired periosteum after elevating flap or after surgical intervention with flap elevation. Methods: Buccal and lingual mucoperiosteal flaps were reflected to surgically create critical-size, "box-type" (4 mm width, 5 mm depth), one-wall, intrabony defects at the distal aspect of the 2nd and the mesial aspect of the 4th mandibular premolars in the right and left jaw quadrants. Animals were sacrificed after 24 weeks. Results: The results from this study are as follows: 1) thickness of periosteum showed difference as follows (P<0.05): control group ($0.45{\pm}0.22$ mm)> flap-elevation group ($0.36{\pm}0.07$ mm)> defect formation group ($0.26{\pm}0.03$ mm), 2) thickness of gingival tissue showed difference as follows (P<0.05): defect formation group ($3.15{\pm}0.40$ mm)> flap-elevation group ($2.02{\pm}0.25$ mm) > control group ($1.88{\pm}0.27$ mm), 3) higher cellular activity was observed in defect formation group and flap-elevation groups than control group, 4) the number of blood vessles was higher in defect formation group than control group. Conclusions: In conclusion, prolonged operation with increased surgical trauma seems to decrease the thickness of repaired periosteum and increase the thickness of gingiva. More blood vessles and high cellular activity were observed in defect formation group.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2003.10a
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• pp.105-126
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• 2003

In Korea most of annual rainfall is concentrated in several episodic heavy rains during the season of summer monsoon and typhoon. Because of uneven rainfall distribution many dams have been constructed in order to secure water supply in dry seasons. The Han River system has the most dams among Korean rivers, and the river is a series of dams now. Reservoirs need different strategy of water quality control from river water. Autochthonous organic matter and phosphorus should be the major target to be controlled in lakes. In this Paper some problems are discussed that makes efforts of water quality improvement ineffective in lakes of Korea, even after the substantial investment to wastewater treatment facilities.1) Phosphorus is the key factor controlling eutrophication of lakes and the reduction ofphosphors should be the major target of water treatment. However, water quality management strategy in Korea is still stream-oriented, and focused on BOD removal from sewage. Phosphorus removal efficiency remains as low as 10-30%, because biological treatment is adopted for both secondary treatment and advanced treatment. The standard for TP concentration of the sewage treatment plant effluent is 6 mgP/l in most of regions, and 2 mg/l in enforced region near metropolitan water intake point. TP in the effluents of sewage treatment plants are usually 1-2 mg/1, and most of plants meet the effluent regulation without a further phosphorus removal process. The generous TP standard for effluents discourages further efforts to improve phosphorus removal efficiency of sewage treatment. Considering that TP standard for the effluent is below 0.1 mg/l in some countries, it should be amended to below 0.1 mg/l in Korea, especially in the watershed of large lakes.2) Urban runoff and combined sewer overflow are not treated, even though their total loading into lakes can be comparable to municipal sewage discharges on dry days. Chemical coagulation and rapid settling might be the solution to urban runoff in regard of intermittent operation on only rainy days.3) Aggregated precipitation in Korea that is concentrated on several episodic heavyrains per year causes a large amount of nonpoint source pollution loading into lakes. It makes the treatment of nonpoint source discharge by methods of other countries of even rain pattern, such as retention pond or artificial wetland, impractical in Korea.4) The application rate of fertilizers in Korea is ten times as high as the average ofOECD countries. The total manure discharge from animal farming is thought to be over the capacity of soil treatment in Korea. Even though large portion of manure is composted for organic fertilizer, a lot of nutrients and organic matter emanates from organic compost. The reduction of application rate and discharge rate of phosphorus from agricultural fields should be encouraged by incentives and regulations.5) There is a lot of vegetable fields with high slopes in the upstream region of the HanRiver. Soil erosion is severe due to high slopes, and fertilizer is discharged in the form of adsorbed phosphorus on clay surface. The reduction of soil erosion in the upland area should be the major preventive policy for eutrophication. Uplands of high slope must be recovered to forest, and eroded gullies should be reformed into grass-buffered natural streams which are wider and resistant to bank erosion.