• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.189-189
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• 2011

인공관절은 노인성 질환이나 자가 면역질환, 신체적인 외상 등으로 인하여 발생하는 관절의 손상 부위를 대체하기 위해 고안된 관절의 인공 대용물이다. 인공 관절 중 인공 고관절의 경우 관절 운동을 하는 라이너(Liner)와 헤드(Head) 부분이 인공관절의 수명을 결정하게 되는데, 헤드 부분에 메탈소재와 라이너 부분에 고분자 소재를 사용하는 MOP (metal on polymer) 구조의 인공관절은 충격흡수의 장점이 있는 반면 wear debris에 의한 골용해로 인하여 관절이 느슨해지는 문제점이 발생하여 재 시술의 주요 원인이 되고 있다. 또한 메탈 헤드의 마모로 인한 금속이온의 용출은 세포 독성의 문제를 야기하여 인공관절의 수명을 낮추는 또 하나의 요인이 되고 있다. 따라서 인공관절의 수명을 늘리기 위해 DLC, ZrO, TiN 등의 높은 경도 값을 갖는 박막을 금속 헤드 위에 증착하여 상대재인 인공관절용 고분자 소재의 마모량을 줄이고자 하는 연구가 활발하게 진행 되고 있다. 본 연구에서는 PIII&D (Plasma Immersion Ion Implantation & Deposition)공정을 이용하여 Co-Cr-Mo 합금 소재 niobium nitride (NbN) 박막을 증착하여 상대제인 UHMWPE (ultra high molecular polyethylene)의 마모를 줄이고자 하는 연구를 진행하였다. 마모량을 감소시키기 위하여, 박막 증착전에 질소를 이온주입하는 pre-ion implantation 공정을 도입하였으며, 또한 Co-Cr 합금과 NbN박막 사이의 접착력을 증가시키기 위하여 박막의 증착 초기에 이온주입과 증착을 동시에 수행하는 dynamic ion mixing공정을 수행하였다. NbN 박막의 특성을 평가하기 위해 XRD, XPS, AFM 등의 분석을 수행하였으며, 상대재인 초고분자량 폴리에틸렌의 마모량을 측정하기 위해 Pin-on-disk tester를 이용하여 마모 실험을 진행하였다. 마모 실험 결과, pre-ion implantation 공정을 도입한 경우 현재 상용화 되어있는 Co-Cr 합금에 비하여 마모량을 2배 이상 감소시키는 것을 확인 할 수 있었으며, dynamic ion mixing 공정을 도입한 경우 장시간의 마모 시험에 대한 마모 특성이 향상 되는 것을 확인 할 수 있었다.

• Tuberculosis and Respiratory Diseases
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• v.64 no.3
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• pp.230-235
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• 2008

We described herein the first case of primary $Sj{\ddot{o}}gren^{\prime}s$ syndrome in Korea which presented with multiple cysts caused by only peribronchiolar lymphocytic infiltration, a rare pulmonary manifestation in $Sj{\ddot{o}}gren^{\prime}s$ syndrome, and was confirmed by surgical lung biopsy. A brief review of the literature has been included.

• Childhood Kidney Diseases
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• v.6 no.2
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• pp.198-208
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• 2002

Purpose : There is no scientific basis for an immunization policy for children with renal disease who have increased risk of infection in Korea. As an initial step in approaching this problem, this survey of pediatric nephrologists was undertaken to determine the current recommendations of practicing pediatric nephrologists Methods : Questionnaires were sent to the members of Korean Society of Pediatric Nephrology via mail and E-mail. The questionnaire was designed to obtain information about the immunization practice of basic vaccination schedule for nephrotic syndrome, the side effects after vaccination and the immunization practice about recommended vaccines for children with renal disease. Results : Questionnaires were sent to 56 pediatric nephrologists. 35 replies were received (response rate: 62.5%). Almost of the respondents (82.8%) reported practicing at university hospital. All respondents reported modified vaccination schedule. 65.7% of the respondents immunized nephrotic children with live vaccines some time later after discontinuation of corticosteroids treatment and 57.1% of respondents immunized them with killed vaccines during medication of low doses of corticosteroids. Respondents experienced relapse of nephrotic syndrome after vaccination are nine, lack of vaccine efficacy are three and infection by organisms of live vaccines are two. 71.4% of respondents reported vaccinating children with renal disease for hepatitis B, pneumococcus and influenza during medication of low doses of corticosteroids. But There is few difference of the rates of respondents vaccinating them for Hemophilus influenzae type b between during medication of low doses of corticosteroids and after discontinuation of corticosteroids treatment (45.7% us 42.9%). Almost of respondents reported vaccinating renal failure children without immunosuppression for hepatitis B, pneumococcus, influenza and H. influenzae type b ($54.3{\sim}77.1%$). Conclusion : Pediatric nephrologists practiced modifying vaccination schedules for children with renal disease in Korea and there was variation according to the progression of disease and the doses of corticosteroids. It is necessary to establish the immunization guideline for children with renal disease through the prospective studies.

• Journal of dental hygiene science
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• v.3 no.1
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• pp.33-38
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• 2003

One aspect of undesirable outcomes in orthodontic treatment includes excessive resorption of dental roots with mechanotherapy. The aim of this study is to demonstrate whether diseases affecting the immune system adversely are prevalent in orthodontic patients who manifest excessive resorption of dental roots with orthodontic tooth movement. The records of 51 orthodontic patients (25 males and 26 females, $16.1{\pm}3.3$ yr old) and 51 pair-matched controls ($1.5.4{\pm}4.1$ yr old) were analyzed retrospectively. The pretreatment questionnaires and the treatment records disclosed that the incidence of asthma, allergy, and signs indicative of psychological stress, was significantly higher in the root resorption cohort. The immune system is either altered or adversely affected in all these conditions. Since the progenitors of osteoclasts and odontoclasts are derived from mononucleated cells of monocyte and macrophage lineage, which are prominent cellular members of the immune system, the study leaded to the conclusion that excessive root resorption may occur in orthodontic patients who are psychologically stressed, or who have asthma and allergy, or any other conditions that may adversely affect and modify the immune system, and a careful examination and interpretation of a patient's medical history may be beneficial to both patient and practioner.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.16 no.2
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• pp.183-191
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• 2005

Tic disorder including Tourette's disorder is a neurodevelopmental disorder that appears in childhood and characterized by the presence of motor and vocal tics. Childhood-onset obsessive-compulsive disorder (OCD) is suggested to be a phenomenologically and etiologically distinct subtype of OCD, bearing a close genetic relationship to tic-disorders. Tourette's disorder and OCD are comorbid in $40-75\%$ of patients initially diagnosed with either disorder. Basal ganglia and cortico-striato-thalamic circuits are implicated in the pathophysiology of both disorders and these disorders have similar clinical features. Over the past decades, the progress in research on Tourette's disorder and OCD has been extraordinary. This review describes some of important insights from these work, involving these areas : 1) clinical implication 2) genetics and epidemiology 3) brain imaging study 4) neuroche-mistry 5) pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS).

• Tuberculosis and Respiratory Diseases
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• v.61 no.6
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• pp.554-561
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• 2006

Background: In AIDS patients, the respiratory tract is one of the most frequently involved site of by an opportunistic infection, and an even common, casual pulmonary infection manifests in a peculiar ways in AIDS patients. In Korea, because of the low prevalence of AIDS, there is insufficient data compared with other Southeast Asian counties. However, considering the sexual behavior of the younger generation, it is expected that it will not be long before AIDS becomes a major public health issue in Korea. This study examined the clinical manifestation of HIV positive people and AIDS patients. The pulmonary manifestion of HIV-positive was evaluated. This study focused on the differences in the clinical manifestation between AIDS patients with pulmonary disease and simple HIV positive people. The characteristics of common pulmonary infections in AIDS patients were also analyzed. Method: The medical records of 28 HIV positive patients who visited the hospital of ChungAng University Hospital from January, 2001 to February, 2006 were analyzed retrospectively. Result: Twenty-seven patients out of 28 HIV positive patients were male and the average age was 40.6(23-65). Patients in their thirties were most commonly affected. Elven patients had pulmonary diseases. Pulmonary tuberculosis (4 cases) and pneumocystis pneumonia (4 cases) were the most common respiratory infection. One patient showed a peculiar type of systemic cryptococcus. which was accompanied by lung and pleural dissemination. The CD4+lymphocyte count of patients with a pulmonary infection was significantly lower in patients with a pulmonary manifestation than those with only a HIV infection ($79.5/mm^3$ vs $400/mm^3$, respectively)(p<.05). Patients with pulmonary disease were in a more severe immunosuppressive state. There were 4 patients with pulmonary tuberculosis, 4 with pneumocystis pneumonia, 4 with secondary syphilis, 2 with primary syphilis, and 2 with HZV infection. The average CD4 lymphocyte counts was $56/mm^3$ in those with pulmonary tuberculosis, $42/mm^3$ in those with pneumocystis pneumonia, and $455/mm^3$ in those with secondary syphilis. Conclusion: This study examined the clinical manifestation of HIV positive patients, particularly AIDS patients with pulmonary disease, A more severe immunosuppressive status was observed in HIV-related pulmonary compared with those with HIV-related extrapulmonary disease, and the frequency of pulmonary tuberculosis in pulmonary disease was higher than expected. Respiratory infection in AIDS manifest in uncommon ways e.g. disseminated cryptococcosis involving the lung and pleura. Evidently, AIDS patients with a respiratory infection have a more severe form of immunosuppression than those with a simple HIV infection. As expected, patients with a pulmonary infection were in a more severe immunosuppressed state than those with a simple HIV infection. Opportunistic infections can show peculiar clinical presentations in AIDS patients.

• Journal of Oral Medicine and Pain
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• v.35 no.2
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• pp.155-163
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• 2010

Dermatomyositis (DM) is an idiopathic inflammatory connective tissue disorder and a systemic autonomic immune disease which shows a progressive muscle weakness and characteristic rash. It is identified by a characteristic rash accompanying, or more often preceding muscle weakness. Pathognomonic skin lesions are a blue-purple discoloration on the upper eyelids with edema (heliotropic rash), a flat red rash on the face and upper trunk, and erythema of the knuckles with a raised violaceous scaly eruption (Gottron's papule). The myopathy represents inflammatory and degenerative changes primarily affecting proximal muscles. DM often involves GI tract and respiratory system with as risk of 15-25% internal malignancy. It's managed with sun protection since muscle weakness as well as a rash could be aggravated by sun exposure. Systemic corticosteroid is an initial therapy and other immunosuppressive agent has been used as alternatives. Facial muscles are unaffected and masticatory muscles are rarely affected in DM. We present trismus close to muscle contracture in a patient with DM. Therefore, it needs continuous mouth-opening exercise to prevent progressive muscle contracture and to ensure normal mouth opening.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.228-228
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• 2012

인공관절은 노인성 질환이나 자가 면역질환, 신체적인 외상 등으로 인하여 발생하는 관절의 손상 부위를 대체하기 위하여 고안된 관절의 인공 대용물이다. 인공 관절 중 인공 고관절의 경우 관절 운동을 하는 라이너(Liner)와 헤드(Head) 부분이 마모에 관여하여 인공관절의 수명에 영향을 미치게 되는데, 헤드 소재로서는 Co-Cr-Mo 합금이, 라이너 소재로서는 고분자 소재인 UHMWPE (Ultra High Molecular Weight Polyethylene)가 주로 사용되고 있다. 이러한 MOP (Metal-On-Polymer) 구조의 인공관절의 경우, 충격흡수의 장점이 있는 반면, 관절 운동시 발생하는 UHMWPE의 wear debris에 의한 골용해로 인하여 관절이 느슨해지는 문제점이 발생하여 재시술을 필요로 하게 된다. 또한 메탈 헤드의 마모로 인한 금속이온의 용출은 세포 독성의 문제를 야기하여 인공관절의 수명을 낮추는 또 하나의 요인이 되고 있다. 이러한 문제점들을 해결 하기 위하여, 본 연구에서는 PIII&D (Plasma Immersion Ion Implantation & Deposition)공정을 이용하여 Co-Cr-Mo 합금 소재 위에 niobium nitride (NbN) 박막을 증착하여 상대재인 UHMWPE의 마모를 줄이고자 하는 연구를 진행하였다. 마모량의 감소를 위하여, 박막을 증착하기 전에 Co-Cr-Mo 합금 위에 질소를 이온주입 하는 pre-ion implantation 공정을 도입하였으며, Co-Cr-Mo 합금과 NbN박막 사이의 접착력을 증가시키기 위하여 박막의 증착 초기에 이온주입과 증착을 동시에 수행하는 dynamic ion mixing공정을 수행하였다. 실험 결과 pre-ion implantation 공정을 도입한 경우 현재 상용화 되어있는 Co-Cr-Mo 합금에 비하여 마모량을 2배 이상 감소시키는 것을 확인 할 수 있었으며, dynamic ion mixing 공정을 도입한 경우 장시간의 마모 시험에서도 UHMWPE의 마모량을 2배 가까이 줄일 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.137-137
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• 2012

인공관절은 노인성 질환이나 자가 면역질환, 신체적인 외상 등으로 인하여 발생하는 관절의 손상 부위를 대체하기 위하여 고안된 관절의 인공 대용물이다. 인공 관절 중 인공 고관절의 경우 라이너(Liner)와 헤드(Head) 부분이 직접적인 마모 운동을 수행하게 되므로, 이 부분의 소재 특성에 따라 인공관절의 수명이 결정 되게 된다. 현재 헤드 소재로서는 Co-Cr-Mo 합금이, 라이너 소재로서는 고분자 소재인 UHMWPE (Ultra High Molecular Weight Polyethylene)가 주로 사용되고 있다. 이러한 MOP (Metal-On-Polymer) 구조의 인공관절의 경우, 충격흡수의 장점이 있는 반면, 관절 운동시 발생하는 UHMWPE 의wear debris에 의해 골용해가 발생하게 되어 인공관절의 수명이 저하되는 문제점이 있으며, 금속 헤드의 마모로 인한 금속이온의 용출은 세포 독성의 문제를 야기하여 인공관절의 수명을 저하시키는 또 다른 원인이 되고 있다. 따라서 본 연구에서는 PIII&D (Plasma Immersion Ion Implantation & Deposition) 공정을 이용하여 금속 (Co-Cr-Mo 합금)소재 위에 세라믹 (niobium nitride) 박막을 증착하여 상대재인 UHMWPE의 마모를 줄이고자 하는 연구를 진행하였다. 금속 소재 위에 증착된 세라믹 박막은 상대재인 UHMWPE의 마모량을 줄여줄 뿐만 아니라 금속이온의 용출을 막아준다는 장점이 있으나, 장시간의 마모 운동에 의하여 발생하는 박막의 박리 현상은 인공관절의 수명을 급격히 저하시키는 또 다른 원인이 된다. 이러한 단점을 해결하기 위하여, 박막의 증착 초기에 이온주입과 증착을 동시에 수행하는 dynamic ion mixing공정을 수행하였다. Dynamic ion mixing 공정을 수행함에 따라 박막과 금속 사이의 접착력이 증가하게 되어, UHMWPE의 마모량이 2배 가까이 감소하는 것을 확인할 수 있었으며, 장시간의 마모시험에서도 우수한 결과를 얻을 수 있었다. 또한 UHMWPE의 마모량을 감소시키기 위하여 박막을 증착하기 전에 금속 소재에 질소 이온주입을 수행하는 pre-ion implantation 공정을 도입하였다. 질소 이온주입 결과 Co-Cr-Mo 합금 표면에 부분적으로 CrN, Cr2N의 세라믹 상이 형성 되는 것을 확인할 수 있었으며, 그에 따라 UHMWPE의 마모량이 2배 이상 감소 되는 것을 확인 할 수 있었다.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.20 no.2
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• pp.50-54
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• 2020

Vici syndrome is a rare, autosomal recessive multisystem disorder characterized by agenesis of the corpus callosum, cataracts, cardiomyopathy, hypopigmentation, immunodeficiency, and delayed development. We report the case of a 3-year-old boy diagnosed with Vici syndrome. He initially presented with hypotonia and sucking problem. Whole-exome sequencing identified novel compound heterozygous mutations, namely c.2254C>T (p.Gln752Ter) and c.5511-5518+2 del TATGCAAAGT in the EPG5 gene. The diagnostic challenges can be attributed to the diverse clinical manifestations. Thus, whole-exome sequencing is a useful diagnostic tool for the genetically and clinically heterogeneous Vici syndrome. This is the first Korean report of a patient with Vici syndrome.