• Title/Summary/Keyword: Defects

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Mineralogical Characterization of the Chuncheon Nephrite: Mineral Facies, Mineral Chemistry and Pyribole Structure (춘천 연옥 광물의 광물학적 특성 : 광물상, 광물 화학 및 혼성 격자 구조)

  • Noh, Jin Hwan;Cho, Hyen Goo
    • Journal of the Mineralogical Society of Korea
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    • v.6 no.2
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    • pp.57-79
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    • 1993
  • Chuncheon nephrite, which was formed by the polymetasomatic alteration of dolomitic marble, can be classified into pale green, green, dark green, and grey types on the basis of their occurrence, mineralogical and textural characteristics. The nephrites consist obiefly of fibrous or hairlike(length/width ratio>10) cryptocrystalline(crystal width < $2{\mu}m$) tremolite, and include less amounts of micro-crystalline diopside, calcite, clinochlore, and sphene as impurities. The oriented and rather curved crystal aggregate, of nephritic tremolite are densely interwoven, resulting in a massive-fibrous texture which may explain the characteristic toughness of nephritic jade. The characteristic greenish color of the nephrite may be preferably related to Fe rather than Cr and Ni. However, the variation of color and tint in the Chuncheon nephrite also depends on the mineralogical and textural differences such as crystallinity, texture, and impurities. The chemical composition of the nephritic tremolite is not stoichiometric and rather dispersed especially in the abundances of Al, Mg, and Ca. Al content and Mg/Ca ratio for the nephritic tremolite are slightly increased with deepening in greenish color of the nephrite. Fe content in the nephritic tremolite is generally very low, but comparatively richer in the dark green nephrite. In nephritic tremolite, wide-chain pyriboles are irregularly intervened between normal double chains, forming a chain-width disorder. Most nephritic tremolites in the Chuncheon nephrite show various type of chain-width defects such as triple chain(jimthompsonite), quintuple chain (chesterite), or sometimes quadruple chain in HRTEM observations. The degree of chain-width disorder in the nephritic tremolite tends to increase with deepening in greenish color. Triple chain is the most common type, and quadruple chain is rarely observed only in the grey nephrite. The presence of pyribole structure in the nephritic tremolite is closely related to the increase of Al content and Mg/Ca ratio, a rather dispersive chemical composition, a decrease of relative intensity in (001) XRD reflection, and an increase in b axis dimension of unit cell. In addition, the degree and variation of chain-width disorder with nephrite types may support that an increase of metastability was formed by a rapid diffusion of Mg-rich fluid during the nephrite formation.

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The effect of chitosan/ACS on bone regeneration in rat calvarial defects (백서두개골 결손부에서 키토산/흡수성 콜라겐 전달체의 골재생)

  • Kim, Soo-Kyoung;Suk, Hun-Joo;Kim, Chang-Sung;Cho, Kyoo-Sung;Chai, Jung-Kiu;Kim, Chong-Kwan;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • v.33 no.3
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    • pp.457-474
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    • 2003
  • The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal of tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can he used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region, For an experimental model, a calvarial defect of rat m s selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted was conducted with by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and his tometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogensis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1%, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.

DIFFERENT WAYS OF SURGICAL MANAGEMENT FOR CHILDREN WITH CONFOUND ODONTOMA IN THE MANDIBLE (아동의 하악골에 발생한 복합 치아종의 외과적 처치에 관한 증례보고)

  • Chung, Woo-Sung;Choi, Yeong-Chul;Lee, Keung-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.26 no.3
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    • pp.499-506
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    • 1999
  • The odontoma is relatively a common benign odontogenic tumor and caused by overgrowth of odontogenic tissues. The recent classification by World Health Organization divides odontoma into 2 groups such as compound odontoma and complex odontoma. Compound odontoma comprises dental tissues, resembling the morphology of a tooth and has predilection for the anterior maxilla. In contrast, complex odontoma has unorganized mass, not resembling the normal tooth and has predilection for the posterior mandible. The etiology of odontoma is unknown and almost asymptomatic. So, it usually is found in routine radiographic examination, and most common presenting symptom is impacted or unerupted permanent teeth and retained primary teeth. It can occurs almost anywhere in jaws. It is desirable that odontoma should be removed by surgical enucleation including follicle and surrounding soft tissues. Considering the age and behavioral cooperation of patient, the development of permanent dentition, the location of odontoma in jaw, the need for the concomitant operative dentistry, operation is performed in outpatient department with/without sedation or under general anesthesia with endotracheal intubation. In this case report, 2 patients with compound odontoma were treated by surgical enucleation including follicle and surrounding soft tissues. One patient, about 5 years old, was treated under general anesthesia and concomitant operative dentistry was performed. The other patient, about 11 years old, was treated under local anesthesia in outpatient department. In 2 cases, after 4 months, surgical defects were filled with new bone and normalization of eruption path of impacted permanent teeth was observed.

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FABRICATION OF MYOMUCOSAL FLAP USING CULTURED ORAL EPITHELIUM IN RABBIT MODEL (가토모델에서 배양 구강상피를 이용한 근-점막 피판의 형성에 관한 연구)

  • Shin, Young-Min;Chung, Hun-Jong;Ahn, Kang-Min;Park, Hee-Jung;Sung, Mi-Ae;Kim, Soung-Min;Hwang, Soon-Jung;Kim, Myung-Jin;Jahng, Jeong-Won;Kim, Sung-Po;Yang, Eun-Kyung;Song, Kye-Yong;Lee, Jong-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.27 no.3
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    • pp.226-237
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    • 2005
  • Purpose : Extensive defect of oral and maxillofacial area is usually reconstructed with composite flap including skin paddle. However, if the defects are lined with only skin components, the mucosa's role in mastication and texture are not restored. Furthermore, stiffness and hair-growing prevent denture rehabilitation and good oral hygiene. This study was performed to overcome the disadvantages of composite soft tissue flaps including the skin and to make a model for myo-mucosal flaps. Materials and methods : Buccal mucosa sized $0.5\times1.0\;cm^2$ from New Zealand rabbit (around 1.5kg) was harvested and cultivated by the modification of Rheinwald and Green's keratinocyte culture method. Cultured mucosa was grafted on the fascia of latismus dorsi as form of mucosal sheet. After 7, 10, 14 days, the myomucosal flap was excised and evaluated under light microscope with H & E and immunohistochemical staining. As control group, harvested buccal mucosa from rabbit was transplanted to gracilis muscle(n=6). Results : From 7 days after prelamination, the basal layer of the grafted mucosa resembled that of normal mucosa. As control group, transplanted mucosa had original shape but there's slight inflammatory reaction. Prelaminated mucosa has 19.8$\pm$4.59 cell layers and some samples have more than 20 layers. The expression rate of PCNA was relatively strong (42.9%$\pm$14.1) at the basal layer of grafted mucosa and the laminin was found at the basal layer. On the contrary, prelaminated mucosa at 10 days showed moderate expression rate of PCNA(32.4%$\pm$4.62). We found the mucosal layer was somehow disappeared and there is strong inflammatory reaction. After 14 days prelamination, the grafted oral keratinocytes were almost disappeared and expression of PCNA was not observed. Conclusion : We can make 75 fold large mucosal($3850mm^2$) sheet from small samples of mucosa $(50mm^2)$. Epithelial sheet that grafted on the fascia of muscle underwent differentiation and proliferation. But after 10, 14 days, there was strong inflammatory reaction and the grafted mucosa was destroyed from surface layer. In rabbit model, transfer of fascio-mucosal flap should be done from 7 to 10 days after prelamination.

A STUDY ON THE EXTRACELLULAR MATRIX IN THE ARTIFICIALLY CHEATED CLEFT LIP WOUND HEALING OF RABBIT FETUSES (토끼 태자에 형성시킨 구순열상의 치유과정에서 세포외기질 분포에 관한 연구)

  • Yang, Won-Sik;Baek, Seung-Hak
    • The korean journal of orthodontics
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    • v.28 no.1 s.66
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    • pp.1-15
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    • 1998
  • Adult wound healing is accompanied with inflammation and eventual scar formation, whereas fetal wounds heal rapidly by mesenchymal proliferation without significant inflammatory cell participation and with minimal or no scar formation. The cellular mechanisms underlying these differing forms of wound healing are unknown but the extracellualr matrix through its effects on cell function, may play a key role. Therefore the purpose of this study is to investigate the spatial and temporal deposition of several component of extracellular matrix, which are known to be involved with scar formation, in the artificially created cleft lip wound healing of fetuses. The author had undergone hysterotomy and created cleft lip-like defects on fetuses of New Zealand White Rabbit in mid-third trimester(24 days). Fetuses were divided into the repaired group, the unrepaired group and the sham-operated control group. At 1, 2, 3, 5, 7 days after procedure, fetuses were obtained by Caeserem section. After documenting the viability of fetuses, they were photographed to compare size and facial morphology and sectioned for histological examination by H & E stain and spatial and temporal deposition of collagen typeI, III, IV, V and fibronectit laminin by immunohistochemical method. The findings are summarized as follows 1. There were lack of inflammation in the repaired and the unrepaired group during experimental periods. 2. The reepithelialization of the unrepaired group was slower than that of the repaired group. 3. Collagen I, III, V were found from post-op. third day. There were no difference of distribution in the control, the repaired and the unrepaired group. Collagen types I, III, V were present in all groups with restoration of the normal collagen pattern in the fetus. This implies that lack of scarring in fetal wounds is due to the difference of collagen organization pattern within wound and not simply lack of collagen formation. 4. Collagen IV was slightly increased at post-op. third day and decreased after post-op. fifth day. Eventually there were no differences in the control, the repaired and the unrepaired group. Lminin was found at post-op. fifth day and maintained staining density until post-op. seventh day. There were no differences in the control, the repaired and the unrepaired group. According to staining of laminin and collagen type IV in epithelial basement membrane, formation of epithelial basement membrane was not completed until reepithelialization was finished. 5. According to staining of laminin and collagen type IV, there were no increase of neovascularity in the repaired and the unrepaired group. 6. Fibronectin was increased until post-op. third day at fibrin clot, wound base and margin and decreased after post-op. fifth day. Eventually, there were no differences in the control, the repaired and the unrepaired group. So it implies fibronectin plays a role as provisional matrix for fetal wound healing.

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Maternal Folate Status and Its Influencing Factors in Early Pregnancy (임신초기 모체의 엽산영양상태와 동 영향인자)

  • 이정아;이종임;임현숙
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.2
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    • pp.331-338
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    • 2004
  • Folate nutrition in early pregnancy is crucial in order to prevent neural tube defects (NTDs) in the fetus and maternal folate deficiency in late pregnancy If the influencing factors on maternal folate status are identified we may be able to detect the women at most risk of folate deficiency. This study intends to determine folate intakes, assess the levels of serum folate, erythrocyte folate, and plasma homocysteine, and reveal theinfluencing factors on maternal folate status in early pregnancy. A total of 151 healthy women in their first trimester volunteered for this study. The average length of gestation period was 9.1$\pm$ 2.3 weeks and seventy subjects were primipara. They consumed 1599$\pm$589 ㎉/day of energy and 230.8$\pm$145.2 $\mu\textrm{g}$/day of folate. This represented 72.5% and 46.2% of the Korean RDA respectively for pregnant women in the first half of Pregnancy. Results show that they consume less folate and energy due to morning sickness. Morning sickness correlated negatively with the intakes of energy, folate, ana Kimchi also. Their levels of serum folate, erythrocyte folate, and plasma homocysteine were 5.5$\pm$1.9 ng/mL, 266.6$\pm$75.0 ng/mL, and 7.0$\pm$1.8 $\mu$mol/L, respectively. Results indicate that 7.8% were deficient and 60.3% were borderline deficient in serum folate, 4.3% were deficient in erythrocyte folate, however, all had normal levels of plasma homocysteine. Results indicate that the folate status was not poor Contributing factors influencing serum folate concentrations ($R^2$= 0.724, p = 0.0001) were self-reported health status (+), folate intake (+), age (-), length of gestation (-), and homocysteine levels (-). Factors influencing erythrocyte folate concentrations ($R^2$ = 0.570, p = 0.0029) were the infant birth height of the last pregnancy (+), energy intake (+), age (-), plasma homocysteine concentration (-), and education level (-). Factors influencing plasma homocysteine concentrations ($R^2$= 0.450, p = 0.0051) were income level (+), prepregnancy weight (+), serum folate concentration (-), and the infant birth weight of the last pregnancy (-). These results indicate that pregnant women are likely to have a folate deficiency if they are in poor health status, having a history of delivering small infant and low energy and/or folate intake, and/or are older. And folate status is likely to decline as pregnancy progresses.

Clinical Study of the Patients, in Whom Pulmonary Embolism was Suspected by Lung Perfusion Scan (폐 관류주사검사상 폐동맥 색전증 소견을 보인 환자의 임상적 고찰)

  • Lee, Gwi-Lae;Kim, Jae-Yeol;Park, Jae-Suk;Yoo, Chul-Gyu;Kim, Young-Whan;Shim, Young-Soo;Han, Sung-Koo
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.4
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    • pp.889-898
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    • 1997
  • Pulmonary Embolism can develop in variable conditions, and presents with nonspecific symptoms and signs. If diagnosis is delayed, it can be resulted in catastrophic results. Therefore, early diagnosis and adequate treatment is crucial in Pulmonary Embolism. Lung Perfusion Scan is useful screening test. Negative result can exclude pulmonary embolism. But, perfusion defects don't always mean pulmonary embolism. To find the better methods of interpretation of lung perfusion scan and To evaluate the clinical course and outcomes of the patients, in whom pulmonary embolism was suspected by lung perfusion scan, we reviewed the clinical records of 49 cases suspected by lung perfusion scan at Seoul National University Hospital during the period of January, 1995 to July, 1996. The results are as follows. First impression of cases in which PE was present at time of admission were pulmonary embolism (63%), heart diseases (26%), and pneumonia (11%) in orders. Underlying diseases of cases in which PE developed during admission were malignancy (36.5%), ICH (22.7%), sepsis (13.7%), and SLE (9.1%) in orders. The predisposing factors were operation (20%), cancer (16%), immobility (16%), connective tissue disease (16%), heart dis. (10%), old age (10%), and preg/pelvic dis. (8%) The results, of lung perfusion scan were HPPE 40 cases(26.8 %), IPPE 21 cases(14.1%), LPPE 88 cases (59.1%), and cases(%) of treatment in these cases were HPPE 34 cases(85%), IPPE 9 cases(42.9%), LPPE 0 case(0.0%). Treatments were heparin and warfarin (69.5%), heparin alone (8.2%), warfarin alone (2.0%), embolectomy (4.1%), thrombolytics (2.0%), IVC filter (2.0%), and no treatment (12.2%) In 34 cases (69.4%), follow up could be done, and 5 cases were recurred (10.2%). The causes of recurrence was incomplete anticoagulant therapy (3 cases) and recurrence of predisposing factor (2 cases). Expired case due to pulmonary embolism was one who was expired just before trial of thrombolytic therapy. Conclusion : Efforts should be made to shorten the interval from onset of Sx to Dx, ie, high index of suspision.

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A study for Developing Performance Assessment Model of Technology Entrepreneurship Education Based on BSC - A Case Study to Graduate School of Entrepreneurial Management - (BSC(Balanced Scorecard) 기반의 기술창업교육 성과평가모형 개발 연구 - 창업대학원 성과평가지표 분석과 개선방안도출을 중심으로 -)

  • Yang, Young Seok
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.8 no.2
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    • pp.129-139
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    • 2013
  • This paper is targeted on proposing ameliorating alternative to performance assessment method of GSEM through evaluating the current one, which is initiated by SMBA to induce fair competition among 5 GSEM across the country and accommodate the quality improvement of entrepreneurship education since 2005 after beginning the SMBA support, from the perspective of BSC(Balanced Scorecard) tool. Ultimately, it complements the policy defects of SMBA over GSEM, in particular, in the process of performance assessment and management. This paper carries out two studies as follow. First, throughout reviewing the previous studies relating to BSC applications to non-profit organization, it set out the direction of introducing BSC in assessing performance of GSEM in order to enhance its effectiveness. Second, it evaluate the rationality of performance assessing tools apllied to GSEM by SMBA on the basis of BSC application over non-profit organization, especially in education institution. Research results shows the following implications. First, the current evaluation system over GSEM is just merely assessment itself and not much contributions for the post performance management. Second, The annual evaluation just remains to check up whether the policy goals are met or not. Third, the current evaluation puts much emphasis just on financial inputs and hardware infra, not considering human resources and utilization of government policy and institution. Fourth, the policy goals are unilaterally focused on entrepreneurs. Fifth, the current evaluation systems do not contain any indexes relating to learning and growth perspectives for concerning sustainable and independent growing up. However, lack of empirical testing require this paper to need the further study in the future.

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Scintigraphic Evaluation of Inhalation Injury in Fire Victims (화재사고시 흡입에 의한 기도손상의 핵의학적 평가)

  • Chun, Kyung-Ah;Cho, Ihn-Ho;Won, Gyu-Jang;Lee, Hyung-Woo;Shin, Kyung-Chul;Jeong, Jin-Hong;Lee, Gwan-Ho
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.1
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    • pp.28-32
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    • 2006
  • Purpose: Conventional chest X-ray and pulmonary function test cannot sensitively detect inhalation injury. Bronchoscopy is known to be the gold standard but it is invasive method. We evaluated whether lung inhalation/perfusion scans can sensitively detect inhalation injury of fire victims. Materials and Methods: Nineteen patients (male 9, female 10, mean age 31.6 yr) of fire victims were enrolled in this study. Inhalation lung scan was performed 2 days later after inhalation injury with $^{99m}Tc$-technegas. Perfusion lung scan was performed 4 days later with $^{99m}Tc$- MAA (macroaggregated albumin). Follow up lung scans were performed 16 and 18 days later for each. Chest X-ray was performed in all patients and bronchoscopy was performed in 17 of 19 patients at the same period. Pulmonary function test was performed in 9 patients. Results: Four of 19 patients showed inhalation and perfusion defects and one showed inhalation defect but, normal perfusion scan findings. These five patients with abnormal scan findings showed abnormal bronchoscopic findings and severe respiratory symptoms. On chest X-ray, 2 of them had pulmonary tuberculosis and one of them showed pulmonary congestion. FEV1 /FVC was abnormal in 3 patients. On the follow up scan, all patients with abnormal initial scan findings showed improved findings and they had improved clinical state. Conclusion: Inhalation/perfusion lung scans can detect inhalation burn injury noninvasively in early stage and may be useful in therapeutic decision making and follow up of patients.

Controversial issues in the legal restriction for prenatal genetic testing in Korea (산전검사 대상 질환에 대한 법적 규제의 문제점에 대한 고찰)

  • Choi, Ji-Young;Jeong, Seon-Yong;Kim, Hyon-J.
    • Journal of Genetic Medicine
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    • v.4 no.2
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    • pp.186-189
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    • 2007
  • More than 6,000 rare disorders including genetic diseases have been reported. Of them, 1,500 diseases (1,211 for clinical diagnosis and 289 for research only) are technically possible for genetic testing. In Korea, since 2005, only 63 genetic diseases is permitted for prenatal genetic testing by the "Bioethics and Biosafety Law". The article 25 in the law prescribes 63 genetic diseases without clear indication for its selection and inclusion criteria. In EU, USA, and other foreign countries, however, there is no provision in the statute on prenatal genetic testing; it is not restricted by a law. Recently, a woman (Mrs. L, 38y) who is a carrier for Menkes disease made an appeal to a government for an amendment of the "Bioethics and Biosafety Law" prohibiting the prenatal diagnosis of her pregnancy at risk for Menkes disease. Menkes disease (MNK) is an X-linked recessive disorder characterized by neurodegeneration, connective tissue defects and hair abnormalities, and no effective treatment is available yet. The prevalence rate of MNK is one in about 250,000 live births. Menkes syndrome patients fail to absorb copper from the gastrointestinal tract in quantities adequate for meeting nutritional needs. These needs seem particularly acute during the initial 12 month of life, when the velocity of brain growth and motor neurodevelopment. Most of pts. die around 3yrs. of age. Mrs. L had a boy with Menkes disease who died at 2y.o. in 2001. Subsequent pregnancy in 2003, she was able to have prenatal genetic testing for mutation of the Menkes (ATP7A) gene and delivered a healthy baby boy. Now, She is pregnant again and wants to have prenatal diagnosis. however, this time, she was not allowed to have any more because Menkes disease is not included in 63 genetic diseases permitted by the law for prenatal genetic testing, in spite of the fact that she is a Menkes disease carrier and her pregnancy is at risk to have an affected baby. This case shows the practical problem of the legal restriction for prenatal genetic testing in Korea. In this study, we report a arguable case and discuss the controversial issues in the legal restriction for prenatal genetic testing in Korea.

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