• The Korean Journal of Nuclear Medicine
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• v.36 no.1
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• pp.1-7
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• 2002

Positron Emission Tomography (PET) is a nuclear medicine imaging modality that consists of systemic administration to a subject of a radiopharmaceutical labeled with a positron-emitting radionuclide. Following administration, its distribution in the organ or structure under study can be assessed as a function of time and space by (1) defecting the annihilation radiation resulting from the interaction of the positrons with matter, and (2) reconstructing the distribution of the radioactivity from a series of that used in computed tomography (CT). The nuclides most generally exhibit chemical properties that render them particularly desirable in physiological studies. The radionuclides most widely used in PET are F-18, C-11, O-15 and N-13. Regarding to the number of the current PET Centers worldwide (based on ICP data), more than 300 PET Centers were in operation in 2000. The use of PET technology grew rapidly compared to that in 1992 and 1996, particularly in the USA, which demonstrates a three-fold rise in PET installations. In 2001, 194 PET Centers were operating in the USA. In 1994, two clinical and research-oriented PET Centers at Seoul National University Hospital and Samsung Medical Center, was established as the first dedicated PET and Cyclotron machines in Korea, followed by two more PET facilities at the Korea Cancer Center Hospital, Ajou Medical Center, Yonsei University Medical Center, National Cancer Center and established their PET Center. Catholic Medical School and Pusan National University Hospital have finalized a plan to install PET machine in 2002, which results in total of nine PET Centers in Korea. Considering annual trends of PET application in four major PET centers in Korea in Asan Medical Center recent six years (from 1995 to 2000), a total of 11,564 patients have been studied every year and the number of PET studies has shown steep growth year upon year. We had 1,020 PET patients in 1995. This number increased to 1,196, 1,756, 2,379, 3,015 and 4,414 in 1996,1997,1998,1999 and 2000, respectively. The application in cardiac disorders is minimal, and among various neuropsychiatric diseases, patients with epilepsy or dementia can benefit from PET studios. Recently, we investigated brain mapping and neuroreceptor works. PET is not a key application for evaluation of the cardiac patients in Korea because of the relatively low incidence of cardiac disease and less costly procedures such as SPECT can now be performed. The changes in the application of PET studios indicate that, initially, brain PET occupied almost 60% in 1995, followed by a gradual decrease in brain application. However, overall PET use in the diagnosis and management of patients with cancer was up to 63% in 2000. The current medicare coverage policy in the USA is very important because reimbursement policy is critical for the promotion of PET. In May 1995, the Health Care Financing Administration (HCFA) began covering the PET perfusion study using Rubidium-82, evaluation of a solitary pulmonary nodule and pathologically proven non-small cell lung cancer. As of July 1999, Medicare's coverage policy expanded to include additional indications: evaluation of recurrent colorectal cancer with a rising CEA level, staging of lymphoma and detection of recurrent or metastatic melanoma. In December of 2001, National Coverage decided to expand Medicare reimbursement for broad use in 6 cancers: lung, colorecctal, lymphoma, melanoma, head and neck, and esophageal cancers; for determining revascularization in heart diseases; and for identifying epilepsy patients. In addition, PET coverage is expected to further expand to diseases affecting women, such as breast, ovarian, uterine and vaginal cancers as well as diseases like prostate cancer and Alzheimer's disease.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.2
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• pp.141-156
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• 2004

Objectives : JianTeng-Yuan(交藤圓) is said to be a prescription for preservation of health in ${\ulcorner}$HuaTuo ZhongZangJing(華陀 中藏經)${\lrcorner}$. It is known to have the effect of Bu-Shen(補腎: strengthening kidney) and Yi-Shou(益壽: prolonging the span of one's life). This study investigates whether JTY is effective on inhibition of oxidation stress. Methods : Sprague-Dawley Rats(12-week-old, weight $300{\pm}20g$) were divided into 3 groups. Normal group(n=8) was injected PBS(1ml/body, s.c) at the back neck's skin. Control group(n=8) was injected D-galactose(50mg/kg, 1ml PBS/body, s.c) to induce pathological animals. JTY group was injected the same treatment for the Control group, and fed containing JTY(10%). The whole groups were treated 1 time per day for 6 weeks. After rats were sacrificed and anti-oxidant enzyme(SOD, CAT, G-px) activity, GSH quantity of RBC and tissue(heart, liver and kidney), plasma Vit-C quantity were examined. Besides, the MDA levels of liver and kidney, lipofuscin of heart and endurance of erythrocyte membrane were measured. Results : In the JTY group, RBC's SOD activity decline was halted by 21% of the normal level, compared to the control group ; G-px activity(unit/g of Hb) increased significantly, compared to the normal group ; and the level of Vit-C in plasma increased by 16%. Heart's SOD activity was kept at the same level as that of the normal group ; and CAT activity decline was halted by 26%. Kidney's CAT and G-px activities were kept at the same level as that shown in the normal group, implying the existence of halting effect. Liver also showed a slight halting effect against the decline of anti-oxidant ability, but the effect was not significant(a=0.05). A comparison between the levels of peroxide in SD rats showed that the level of TBARS in plasma increased significantly in the control group and that it was normal in the JTY group. The livers in the JTY group, compared to those in the control group, showed 36% halting effect of the normal level while their kidney's indicated the level significantly lower than the normal level. Heart's lipofuscin increased significantly in the control group, but was alike in both the JTY and the normal groups. Endurance of erythrocyte membrane(%) decreased significantly in the control group while it was kept at the similar level in both the JTY and the normal groups, indicating the halting effect. Conclusions : This study suggests that JTY is effective to defend oxidation stress caused by D-galactose in the animals. It showed that the anti-oxidant ability was maintained and strengthened. On the other hand, it reduced the level of peroxide in animals. In sum, JTY appeared to have the equilibrium normal physiological function in SD rat.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.2
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• pp.147-161
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• 2012

This study is to assess the effect of horizontal misfit of an implant supported 3-unit fixed prosthodontics on the stress development at the marginal cortical bone surrounding implant neck. Two finite element models consisting of a three unit fixed prosthodontics and an implant/bone complex were constructed on a three dimensional basis. The three unit fixed prosthodontics were designed either shorter (d=17.8mm model) or longer (d=18.0mm model) by 0.1mm than the span of two implants placed at the mandibular second premolar and second molar areas 17.9mm apart. Fitting of the fixed prosthodontics onto the implant abutments was simulated by a total of 6 steps, that is to say, 0.1mm displacement per each step, using DEFORM 3D (ver 6.1, SFTC, Columbus, OH, USA) program. Stresses in the fixed prosthodontics and implants were evaluated using von-Mises stress, maximum compressive stress, and radial stress as necessary. The d=17.8mm model assembled successfully on to the implant abutments while d=18.0mm model did not. Regardless if the fixed prosthodontics fitted onto the abutments or not, excessively higher stresses developed during the course of assembly trial and thereafter. On the marginal cortical bone around implants during the assembly, the peak tensile and compressive stresses were as high as 186.9MPa and 114.1MPa, respectively, even after the final sitting of the fixed prosthodontics (for d=17.8mm model). For this case, the area of marginal bone subject to compressive stresses above 55MPa, equivalent of the $4,000{\mu}{\varepsilon}$, i.e. the reported threshold strain to inhibit physiological remodeling of human cortical bone, extended up to 2mm away from implant during the assembly. Horizontal misfit of 0.1mm can produce excessively high stresses on the marginal cortical bone not only during the fixed prosthodontics assembly but also thereafter.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.254-264
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• 2004

Purpose: This study was carried out to confirm clinical values and limitations of postoperative radiotherapy for hypopharyngeal carcinoma, to evaluate various prognostic factors which may affect to the treatment results and to use these results as fundamental data for making a new treatment strategy. Methods and Materials:. A retrospective analysis was peformed on 64 previously untreated patients with squamous cell carcinoma of the hypopharynx, seen between 1988 and 1999 at Pusan National University Hospital. Most of patients were treated by laryngopharyngectomy and neck dissection followed by conventional fractionated postoperative radiotherapy on surgical bed and cervical nodal areas. Results: The five-year overall survival rate and cause-specific survival rate were 42.2 percent and 51.6 percent, respectively. Univariate analysis of various clinical and pathologic factors confirmed the overall stage, TN-stage, secondary primary cancers, surgical positive margin, nodal extracapsular extension, total radiation doses as significant prognostic factors of hypopharyngeal carcinomas. But in multivariate analysis, TN-stage, surgical positive margin and extracapsular extesion were only statistically significant. Conclusion: In resectable cases of hypopharyngeal carcinoma, combined surgery and postoperative radio-therapy obtained good treatement results, even though sacrificing the function of larynx and pharynx. But in advanced and unresectable cases, with respect to survivals and qualify of life issues, we were able to confirm some limitations of combined therapy. So we recommend that comparative studies of recent various chemo-radiotherapy methods and advanced radiotherapy techniques with these data should be needed.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.25 no.2
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• pp.1-19
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• 2012

Objective : The purpose of this study is to investigate about comparison of Eastern-Western medicine on the acne. Methods : We searched Eastern and Western medicine books for acne. We analyzed these books and examined category, definition, etiology, classification, internal and external methods of treatment of acne. Results : The results were as follows. 1. In Eastern medicine, Acne belongs to the category of the Bunja(粉刺), Jwachang(痤瘡), Pyepungbunja(肺風粉刺). In Western medicine, the other name of Acne is acne vulgaris. 2. In Eastern medicine, the definition of Acne includes manual extraction of comedones and skin appearance. In Western medicine, Acne is a common skin disease during adolescence and a chronic inflammatory disease of pilosebaceous unit of self localization. It is characterized by noninflammatory, open or closed comedones and by inflammatory papules, pustules, and nodules and it affects the areas of skin with the densest population of sebaceous follicles, these areas include the face, neck, back, and the upper part of the chest. 3. In Eastern medicine, the cause and mechanism of Acne arose from the state of internal dampness-heat and spleen-stomach internal qi deficiency due to dietary irregularities and then invaded external pathogen such as wind-dampness-heat-cold-fire in lung meridian lead to qi and blood heat depression stagnation. So it appears in skin. In Western medicine, the etiology and pathogenesis of Acne is clearly not identified, but there are most significant pathogenic factors of blood heat depression stagnation. So it appears in skin. In Western medicine, the etiology and pathogenesis of Acne is clearly not identified, but there are most significant pathogenic factors of Acne; Androgen-stimulated production of sebum, hyperkeratinization and obstruction of sebaceous follicles, proliferation of Propionibacterium acnes and inflammation, abnormaility of skin barrier function, genetic aspects, environmental factors etc. 4. In Eastern medicine, differentiation of syndromes classifies clinical aspects, and cause and mechanism of disease; the former is papular, pustular, cystic, nodular, atrophic, comprehensive type; the latter is lung blood heat, intestine-stomach dampness-heat, phlegm-stasis depression, thoroughfare-conception disharmony, heat toxin type. In Western medicine, it divides into an etiology and invasion period, and clinical aspects; Acne neonatorum, Acne infantum, Acne in puberty and adulthood, Acne venenata; Acne vulgaris, Acne conglobata, Acne fulminans, Acne keloidalis. 5. In Eastern medicine, Internal methods of treatment of Acne are divided into five treatments; general treatments, the treatments of single-medicine and experiential description, the treatments depending on the cause and mechanism of disease, and clinical differentiation of syndromes, dietary treatments. In Western medicine, it is a basic principles that regulation on production of sebum, correction on hyperkeratinization of sebaceous follicles, decrease of Propionibacterium acnes colony and control of inflammation reaction. Internal methods of treatment of Acne are antibiotics, retinoids, hormone preparations etc. 6. In Eastern medicine, external methods of treatment of Acne are wet compress method, paste preparation method, powder preparation method, pill preparation method, acupuncture and moxibustion therapy, ear acupuncture therapy, prevention and notice, and so on. In Western medicine, external method of treatments of Acne are divided into topical therapy and other surgical therapies. Topical therapy is used such as antibiotics, sebum regulators, topical vitamin A medicines etc and other surgical therapies are used such as surgical treatments, intralesional injection of corticosteroids, skin dermabrasion, phototherapy, photodynamic therapy, and so on. Conclusions : Until now, there is no perfect, effective single treatment. We think that Eastern medicine approach and treatment can be helpful to overcome the limitations of acne cure.