• Journal of Chest Surgery
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• v.40 no.3 s.272
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• pp.180-192
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• 2007

Background: As determined from the recent investigations of discordant cardiac xenotransplantation, hyperacute rejection occurs mainly at the endothelial cells in donor microvascular systems, but this does not occur at cardiac valve leaflets or at medium-to-large caliber vessels. On the basis of this background, this study was performed to look into the biocompatibility for transplantation of a middle or large diameter xenogenic blood vessel by conducting xenogenic arterial transplantation with the carotid artery in a pig-to-goat model. Material and Method: The experimental group was composed of 10 pairs of pig-to-goat combinations. They were divided into each period of 1 week, and 1, 3, 6 and 12 months. Four carotid artery grafts obtained through collection of the bilateral carotid arteries from two pigs were preserved at $-70^{\circ}C$ without other treatment, and then they were transplanted into the bilateral carotid arteries of two goats. Doppler ultrasonography was done on a periodic basis after transplantation to evaluate the patency of the grafted blood vessel. At the ends of a predetermined period, the grafts were explanted from the goats and they underwent gross examination. Hematoxylin-eosin and Masson's trichrome staining were conducted. In addition, in order to examine the immunological rejection of the grafted xenogenic blood vessel, immunohistochemical staining was conducted with T-lymphocyte indicator and von Willebrand factor. Result: Two goats at the each one-week period and the one-year period died during the experimental period because of a reason unrelated to the experimental procedure, and the remaining 8 goats survived until the end of each experiment period. On Doppler ultrasonography, unilateral carotid artery occlusion was found in a goat, whose period was specified as 3 months, among the 8 survived goats. However, the vascular patency was maintained well and there was no graft that formed aneurysms in the other goats. On gross examination, the region of vascular anastomosis was preserved well, and calcification of the grafted blood vessel was not shown. Histologically, the endothelial cells of the graft disappeared one week after transplantation, and then there was progressive spread of the recipients' endothelial cells from the anastomotic site. The reendothelialization occurred over the whole graft at one month after transplantation. The neointimal thickening and adventitial inflammation became severe by 3 months after transplantation, but this lessened at 6 months and 12 months, respectively. The rate of CD3 positive cells was very low among the infiltrated inflammatory cells. Conclusion: The fresh-frozen xenogenic artery kept its patency without being greatly influenced by xenogenic immune reaction.

• Korea journal of population studies
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• v.28 no.2
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• pp.33-62
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• 2005

This study aims to explain the current upheaval in marriage that many young Korean men and women postpone or deny their marriage. In order to explain the delayed marriage, we need to understand the taste by which men and women choose their partners, the opportunity by which they find their ideational half in reality, and the context in which these values and opportunities of marriages intersect. This study examines the way in which the value and opportunities of marriage among Korean men and women have intersected differently in the changing economic conditions. Using KLIPS(Korea Labor Income Panel Survey, 1998-2002), differential effects of education and occupational status on marital time according to marriage cohort and gender are analyzed. Results find that the opportunity of marriage among men turns out to have been stratified significantly according to their educational achievement and labor status since the 1990s. For women, education and economic activities are likely to influence marriage decision in a discordant way; during the period of 1990-997, highly educated women are more likely than their counterparts to be married earlier while there is no significant difference according to economic activities. This implies that status homogamy has been intensified since the 1990s and many women with high motivation for social status are able to achieve a vicarious social status through marriage in a prosperous economy. For women married after 1998, however, the educational effect is insignificant but economic activity contributes to delaying marriage. This suggests that under the economic restructuring since the late 1990s, the constraint of opportunities finding decent jobs particularly for men results in the contingent change in women's perception about family roles and economic activities by reducing their expectation to achieve a vicarious status through marriage, but increasing their motive for their own economic activities.

• Journal of Chest Surgery
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• v.38 no.2 s.247
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• pp.132-138
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• 2005

Background: Mitral valve repair (MVP) is the optimal procedure for mitral regurgitation (MR), however, failure and subsequent reoperations are the limitations. The current study assessed the procedure in relation to the primary valve related causes of recurrent MR. Material and Method: MR was treated in 493 patients undergoing MVP from January of 1994 to January of 2002. The causes of MR were degenerative $(n=252,\;51.5\%),$ rheumatic $(n=156,\; 31.6\%),$ and others $(n=85,\; 16.9\%).$ Surgery comprised 446 ring annuloplasties $(90.5\%),$ 227 new chordae formations $(46\%),$ 125 quadriangular resections $(25.3\%),$ 28 chordae transfers $(5.7\%),$ and 8 Alfieri's stitches $(1.6\%).$ The mean follow up was $29.04\pm22.81$ months. Result: There were 5 early $(1.01\%)$, and 5 late deaths $(1.01\%).$ The reoperation rate was $1.42\%$. There were 45 $(9.1\%)$ recurrent MR (grade III or IV). Of these, 24 were procedure related including incomplete repair (n=14), discordant new chordae length (n=8) and others (n=2). In 21 patients, the cause was valve related including rheumatic disease progression (n=10), recurrent chordae elongation or prolapse (n=5) and others (n=6). Severe MR was higher after incomplete repair (p < 0.001), and valve related failure strongly correlated with rheumatic progression (p < 0.05). Conclusion: Since completeness of operation is the prime risk factor that determine the repair durability, intra-operative assessment of the initial repair with trans-esophageal echocardiography is essential.

• Journal of Chest Surgery
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• v.37 no.5
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• pp.391-400
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• 2004

Xenotransplantation in discordant species results in immediate and irreversible hyperacute rejection due to natural antibodies, IgM. With this, antibody depletion is one option to reduce hyperacute rejection, we investigated the effect of PCPP (postcentrifugal plasmapheresis) on the depletion of natural antibodies and the effect of antibody titer on xenograft survival. Material and Method: Outbred swines (n=4) weighing 10∼20 kg were used as donors and mongrel dogs (n=4) weighing 25∼30 kg were used as recipients. Recipient canines underwent plasmapheresis (COBE TPE Laboratories, Lakewood. CO, USA). Pre-transplantation PCPP was peformed on day －2 and day 0. There were three groups (Group 0: no PCPP, Group 1: 1 pla sma-volume (PV) at day －2 and 2 PV at day 0, Group 2: 2 PV at day －2 and 2 PV at day 0). A swine heart was heterotopically transplanted into a recipient's abdominal infrarenal aorta and inferior vena cava. Mean percent depletion of total IgM and IgG in plasma of the recipients was calculated. Serum albumin, electrolyte, complement activity and coagulation factors were measured. Histopathologic examination of heart specimens was performed. Result: Mean percent depletion of IgM and IgG were 95.7$\pm$1.2%, 80.5$\pm$2.4% in the group 2 at the end of PCPP. The percent depletion of serum albumin concentration was decreased from 2.8 to 1.4 g/㎗ in the group 1 and 3.0 to 1.5 g/㎗ in the group 2. Complement hemolytic activity was decreased in group 1 and 2, but returned to normal level within 24 hours. Complement hemolytic activity was reduced to 10% of pre-PCPP level in group 2. Serum fibrinogen decreased to 20% or less and was recovered within 24 hours in group 2. Antithrombin III decreased but less than fibrinogen. PT and aPTT were sometimes but not always prolonged during plasmapheresis. After plasmapheresis, PT and aPTT were prolonged beyond the measurable level. D-dimer was not found during PCPP, but appeared and maintained from 10 minutes after trasplantation. Graft Survival time was 5 min in group 0, and it was 90$\pm$0 min in the group 2. Histopathologic changes were more typically characterized by edema, hemorrhages, thrombosis in all groups at the end of experiment. Conclusion: PCPP effectively removed immuoglobulins and reduced the titer of natural antibodies, as a result, significantly prololonged swine heart xenograft survival.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.21-25
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• 2005

Purpose: $^{14}C$-urea breath test (UBT) is a non-invasive and reliable method for the diagnosis of Helicobacter pylori (HP) infection. In this study, we evaluated the diagnostic performance of a new and rapid $^{14}C$-UBT (Heliprobe method), which was equipped with $Geiger-M\ddot{u}ller$ counter and compared the results with those obtained by using the conventional method. Materials and Methods: Forty-nine patients with dyspepsia underwent gastroduodenoscopy and $^{14}C$-UBT. A 37 KBq $^{14}C$-urea capsule was administered to patients and breath samples were collected. In Heliprobe method, patients exhaled into a Hellprobe BreathCard for 10 min. And then the activities of the BreathCard were countered using Heliprobe analyzer. In the conventional method, results were countered using liquid scintillation counter. During gastroduodenoscopy, 18 of 49 patients were underwent biopsies. According to these histologic results, we evaluated the diagnostic performance of two different methods and compared them. Also we evaluated the concordant and disconcordant rates between them. Results: In all 49 patients, concordant rate of both conventional and Heliprobe methods was 98% (48/49) and the discordant rate was 2% (1/49). Thirteen of 18 patients to whom biopsies were applied, were found to be HP positive on histologic results. And both Heliprobe method and conventional method classified 13 of 13 HP-positive patients and 5 of 5 HP-negative patients correctly (sensitivity 100%, specificity 100%, accuracy 100%). Conclusion: The Heliprobe method demonstrated the same diagnostic performance compared with the conventional method and was a simpler and more rapid technique.