• Journal of the Korean Arthroscopy Society
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• v.4 no.1
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• pp.71-75
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• 2000

Purpose : To introduce arthroscopic partial meniscectomy fur bucket handle tear of medial meniscus using posteromedial portal, which is superior to arthroscopic partial meniscectomy using standard anterior portals commonly used. Method : After arthroscopic examination of the knee, we reduce the torn meniscus, advance the arthroscope into posteromedial compartment under arthroscopic visualization, we make posteromedial portal with reexamination of the compartment and perform arthroscopic partial meniscectomy. Conclusion : With the technique of arthroscopic partial meniscectomy using standard anterior portals, accurate partial meniscectomy can not be done because of inadequate visual field, associated meniscal injuries of posterior horn and cartilage lesion of posterior aspect of the medial femoral condyle can be missed, commonly posterior cruciate ligament can be injured and artificial damage to weight bearing surface of medial femoral condyle is possible. An arthroscopic partial meniscectomy using posteromedial portal is an excellent method fur bucket handle tear of medial meniscus.

• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.67-71
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• 2016

Two Korean Rhodeus bittering fishes are known as having a unique reproduction system that the female deposits its egg inside freshwater mussels. Among them, R. ocellatus and R. uyekii show an ecological difference in feeding items and micro-habitat. Through a light microscope, the visual cells of the retina in the two species were investigated to get information between vision and environment related with habitat. The two fishes' eyes are spherical and R. ocellatus has relatively larger eyes. For the two species, the visual cells of the retina consisted of long single cones, short single cones, unequal double cones and rods. In the cones, all show a row mosaic pattern. Although the two species have a different micro-habitat in the wild, the component of the visual cells was very similar to each other.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.1_2
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• pp.105-116
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• 1992

Latissimus dorsi myocutaneous flap is useful for the breast reconstruction, chest wall coverage, free flap transfer, and head and neck area reconstruction, especially in large defect. We have had some experience of 5-pedicled and 1-free latissimus dorsi myocutaneous flap in head and neck area and found many advantages and some problems. The conclusions were as follows : 1. Potentially large flap size enabled us agressive tumor resection and reconstruction. 2. Speedy and easy flap elevation and long vascular pedicles reduced operation time and flap failure. 3. Due to fewer complication and functional loss of doner site, pedicled latissimus dorsi flap was a good choice for large head and neck reconstruction. 4. Because of flap bulkness, thin and small defect was not appropriate for reconstruction.

• The Journal of the Korea Contents Association
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• v.6 no.6
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• pp.117-124
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• 2006

Thanks to globalization and multi-corporations which have further created complex economic systems over the years, we are now experiencing new aspects of economic challenges as well. Any country abiding by law and order is required to have taxpayer's consent and cooperation upon levying taxes, however, taxpayers will resist or try to avoid paying taxes at all if they can. Particularly, it becomes easier for them to do by using tax haven wherever they we, and their endeavor is not likely to stop as long as they can. These kinds of actions have undoubtedly created tax loopholes which have in fact surfaced and brought to attention to many. Inevitably, each country aggressively pursuits to exchange tax information with others and cooperate each other Thus this study will look into various types of international tax avoidance cases and its root causes and focuses on ways to cooperate amongst nations. The study also suggests possible ways to develop and enhance international tax systems for all the parties concerned.

• Radiation Oncology Journal
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• v.10 no.1
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• pp.43-48
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• 1992

Between December 1983 and December 1989, twenty-five breast carcinoma patients were treated with surgical resection and postoperative radiotherapy at Inje University Seoul Paik Hospital. Twenty-three of 25 were evaluable and there were 7 patients with stage II ,14 patients with stage III, and 2 patients with stage IV. Twenty-one patients were treated with modified radical mastectomy and the remained 2 patients with simple mastectomy. The follow-up period ranged from 2 to 8 years. The local control rate was $83\%$ for the entire group. The local control rates for each stage were $100\%$(6/6) for stage II, $73\%$(11/15) for stage III, and $100\%$(2/2) for stage IV. The number of metastatic axillary nodes was a good predictor of locoregional cotrol. It was $100\%$ for the patients with 0-3 metastatic nodes and $72\%$ for more than 4 nodes, respectively. The 5-year overall survival rate for the entire group was $59\%$, and the disease-free survival rate was $32\%$, The 5-year survival rates for each stage II, III and IV was $83\%$, $59\%$ and $50\%$, respectively. The distant metastasis occured in 10 out of 23 patients and the most common site was bone. The results indicate that postoperative radiotherapy continues to play an important role in the primary.

• Applied Microscopy
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• v.30 no.2
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• pp.121-139
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• 2000

The morphogenesis of neuroblasts and plexiform layers, and establishment of its synapses were studied by electron microscopy in human embryos and fetuses ranging from 10 mm to 260 mm crown-rump length ($5\sim30$ weeks of gestational age). At 30 mm fetus the developing retina was composed of outer and inner neuroblastic layers . Cell division of outer neuroblast was occurred until 90 mm fetus. The transient layer of Chievitz was formed by 30 mm fetus, inner plexiform layer by 50 mm fetus, and outer plexiform layer by 150 mm fetus. The cytoplasm of differentiating ganglion cells contained ribosomes, rough endoplasmic reticula, Golgi complexes, microtubules and dense bodies. The processes of $M\ddot{u}ller$ cell penetrated between groups of ganglion cell axons, and formed the cellular component of the inner limiting membrane at 30 mm fetus. At 90 mm fetus radial fibers of M ller cells contained extensive smooth endoplasmic reticula and microtubules. In each specimen , apposing paired membrane specializations were classified as junctions without synaptic vesicles, conventional synapses and ribbon synapses. At 50 mm fetus the processes of neuroblasts in inner plexiform layer were interconnected by junctions without synaptic vesicles. Conventional synapses developed by addition of synaptic vesicles to initially vesicle-free junctions at 90 mm fetus. At 150 mm fetus ribbon synapses were first recognized by the inclusion of a prominent electron-dense material associated with synaptic vesicles. By 260 mm fetus conventional and ribbon synapses and junctions without synaptic vesicles formed similar to those found in the adult.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.541-548
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• 2013

Purpose: Marrow stromal cells (MSCs) have been known for their potential to trans-differentiate into neural and glial cells in vitro and in vivo. To investigate the influence of the developing host environment on the survival and morphological and molecular differentiation, murine MSCs transplanted into the eye of Brazilian opossum (Monodelphis domestica). Methods: Enhanced green fluorescent protein (GFP) - expressing MSCs were transplanted into developing Brazilian opossums. Animals were allowed to survive for up to 4 weeks after transplantation, at which time the eyes were prepared for immunohistochemical analysis. Results: Some transplanted MSCs survived and showed morphological differentiation into neural cells with some processes within the host vitreous chamber. Some transplanted cells expressed class III ${\beta}$-tubulin (TuJ1, a marker for neuronal cells) or glial fibrillary acid protein (GFAP, a marker for glial cells) or Nestin (a marker for neural stem cells). In addition, some transplanted cells were located in ganglion cell layer but did not show morphological and molecular differentiation. Conclusions: Our result show that the most effective stage of development for transplantation into the retina was postnatal day 16, which retinas developmentally corresponded to postnatal day 4-5 days mouse retina based on cell differentiation and lamination patterns. The present findings suggest that the age of the host appears to play a key role in determining cell fate in vivo.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.391-396
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• 2015

Purpose: The objective of this study was to investigate the visual system of the greater horseshoe bat (Rhinolophus ferrumequinum) by location analysis of some major neurotransmitters glutamate, ${\gamma}$-aminobutyric acid (GABA), acetylcholine, and their receptors, and $m{\ddot{u}}ller$ glial cells in retina. Methods: Standard immunocytochemical techniques were used after vibratome section of retinal tissues of adult greater horseshoe bat for this study. Immnoreactions in immunofluorescence images were analyzed using confocal microscope. Results: Anti-glutamate-immunoreactive neurons were mainly localized in the ganglion cell layer (GCL). The majority of anti-GABA-immunoreactive cells distributed in the inner nuclear layer (INL), and GABAA receptors were localized in the inner plexiform layer (IPL). Anti-choline acetyltransferase-immuoreactive cholinergic neurons were mainly located in the INL and GCL, and most of nicotinic acetylcholine receptors were localized in the IPL. The $m{\ddot{u}}ller$ cells in the retina of the greater horseshoe bat stretched theirs range from the GCL to outer nuclear layer (ONL). Conclusions: This study revealed that the retinas of the greater horseshoe bats contain the same major neurotransmitters and receptors, and glial cell in visually functional mammalian retinas. The present results may suggest that the greater horseshoe bats have the functional retinas for visual analysis through the organized retinal neural circuits.

• Progress in Medical Physics
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• v.16 no.3
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• pp.148-154
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• 2005

Since the output of retina for visual stimulus is carried by neurons of very diverse functional properties, it is not adequate to use conventional single electrode for recording the retinal action potential. For this purpose, we used newly developed multichannel recording system for monitoring the simultaneous electrical activities of many neurons in a functioning piece of retina. Retinal action potentials are recorded with an extra-cellular planar array of 60 microelectrodes. In studying the collective activity of the ganglion cell population it is essential to recognize basic functional distinctions between individual neurons. Therefore, it is necessary to detect and to classify the action potential of each ganglion cell out of mixed signal. We programmed M-files with MATLAB for this sorting process. This processing is mandatory for further analysis, e.g. poststimulus time histogram (PSTH), auto-correlogram, and cross-correlogram. We established MATLAB based protocol for waveform classification and verified that this approach was effective as an initial spike sorting method.

• Journal of Life Science
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• v.23 no.8
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• pp.1064-1072
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• 2013

Circadian rhythm is controlled by hormonal oscillations governing the physiology of all living organisms. In mammals, the main function of the pineal gland is to transform the circadian rhythm generated in the hypothalamic suprachiasmatic nucleus into rhythmic signals of circulating melatonin characterized by a largely nocturnal increase that closely reflects the duration of night time. The pineal gland has lost direct photosensitivity, but responds to light via multi-synaptic pathways that include a subset of retinal ganglion cells. Rhythmic control is achieved through a tight coupling between environmental lighting and arylalkylamine-N-acetyltransferase (AANAT) expression, which is the rhythm-controlling enzyme in melatonin synthesis. Previous studies on the nocturnal expression of AANAT protein have described transcriptional, post-transcriptional, and post-translational regulatory mechanisms. Molecular mechanisms for dependent AANAT expression provide novel aspects for melatonin's circadian rhythmicity. Extensive animal research has linked pineal melatonin for the expression of seasonal rhythmicity in many mammalian species to the modulation of circadian rhythms and to sleep regulation. It has value in treating various circadian rhythm disorders, such as jet lag or shift-work sleep disorders. Melatonin, also, in a broad range of effects with a significant regulation influences many of the body's physiological functions. In addition, this hormone is known to influence reproductive, cardiovascular, and immunological regulation as well as psychiatric disorders.