• Journal of Chest Surgery
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• v.40 no.3 s.272
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• pp.168-179
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• 2007

Background: The recent trend of an increasing number of patients with acute cardiogenic shock or chronic congestive heart failure following myocardial infarction, as well as the considerable number who can not be weaned from cardiopulmonary bypass after open heart surgery, call for immediate efforts to develop affordable ventricular assist devices that are suitable for the Korean physique. Recently, a pneumatic pulsatile ventricular assist device (VAD), named DKUH-75, has been developed by the Department of Biomedical Engineering, in collaboration with the Department of Thoracic and Cardiovascular Surgery of Dankook University College of Medicine. The feasibility of the DKUH-75 VAD was evaluated on the bases of common hemodynamic variables and echocardiographic measurements in pigs, which are subjected to an acute cardiogenic shock state following myocardial infarction, using a novel coronary artery ligation method employing the ischemic preconditioning concept. Material and Method: Acute cardiogenic shock was induced in 10 Yorkshire Landrace Duroc strain pigs by ligating the left anterior descending coronary artery via an ischemic preconditioning process. The hemodynamic variables were monitored, with epicardial echocardiographic measurements performed before and one hour after the ligation. The DKUH-75 VAD was implanted into 5 pigs one hour after the onset of the shock. The hemodynamic variables and echocardiographic measurements were taken one hour after installation of the VAD. Result: The systolic, diastolic and mean systemic arterial pressures were significantly decreased in all the experimental animals one hour after the ligation. The systolic, diastolic and mean pulmonary arterial pressures were increased (Eds note: this completely contradicts the preceding statement? However, if you mean the non-experimental animals this should be stated?). The left ventricular end diastolic pressure (LVEDP) was increased, but the cardiac index decreased, An increase in the left ventricular end systolic dimension and decreases in the fractional shortening and ejection fraction were observed all animals one hour after the coronary artery ligation. In all 5 of the VAD implanted pigs, the systolic and mean systemic arterial pressures were increased, and the pulmonary arterial pressures decreased one hour after the implantation; the LVEDP decreased, but the cardiac index was significantly increased, In the echocardiographic measurements, the left ventricular end systolic dimension decreased after the implantation of the VAD, but the fractional shortening and ejection fraction significantly increased. Conclusion: Significant improvements in the hemodynamic variables and echocardiographic measurements were observed in the 5 VAD implanted animals one hour after installation, which had been subjected to an acute cardiogenic shock state by ligation of the coronary artery, indicating that the DKUH-75 VAD could help in the recovery of the myocardial function. This suggests that the DKUH-75 VAD is feasible in the short term in relation to an acute cardiogenic shock state due to myocardial infarction.

• Tuberculosis and Respiratory Diseases
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• v.60 no.1
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• pp.65-71
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• 2006

Background : Hemoptysis, when massive and untreated, has a mortality rate of over 50 percents, is considered as one of most dreaded of all respiratory emergencies and can have a variety of underlying causes. Bronchial artery embolization (BAE) has become an established procedure in the management of massive and recurrent hemoptysis, and its efficacy is widely documented thereafter by number of articles. However, the long-term success rate of BAE is known to be unfavorable. Risk factors influencing that control failure are inevitably needed. Materials and methods : Seventy-five patients underwent bronchial artery embolization due to massive hemoptysis in Severance Hospital from Jan. 2000 to Jan. 2005. Nine patients' data were not available and could not be contacted with. Finally 66 patients' (48 males, 18 females) medical records were analyzed retrospectively during a mean follow up period of 20.4 months (ranging from 1 month to 54 months). Results : Among 66 patients whose data were available, 23(34.9%) patients had recurrent major hemoptysis. Patients' age, sex, underlying disease, previous intervention history, and number of feeding vessels had no statistical validity as risk factors of recurred major hemoptysis. But bilaterality of lesion, amount of hemoptysis, and pleural thickening were revealed as meaningful factors for predicting relapse (p = 0.008, 0.018, and 0.001, respectively). Conclusion : According to our series, patients presenting with larger amount of hemoptysis, pleural thickening of chest radiography and bilateral lesion are associated with increased risk of major hemoptysis in patients treated with BAE.

• Radiation Oncology Journal
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• v.29 no.1
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• pp.44-52
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• 2011

Purpose: To evaluate the outcomes and prognostic factors of postoperative radiotherapy (PORT) for patients with pathological stage III non-small-cell lung cancer (NSCLC) at a single institution. Materials and Methods: From 2000 to 2007, 88 patients diagnosed as having pathologic stage III NSCLC after curative resection were treated with PORT. There were 80 patients with pathologic stage IIIA and eight patients with pathologic stage IIIB in the AJCC 6th staging system. The majority of patients (n=83) had pathologic N2 disease, and 56 patients had single station mediastinal LN metastasis. PORT was administered using conventional technique (n=76) or three-dimensional conformal technique (n=12). The median radiation dose was 54 Gy (range, 30.6 to 63 Gy). Thirty-six patients received chemotherapy. Radiation pneumonitis was graded by the Radiation Therapy Oncology Group system, and other treatment-related toxicities were assessed by CTCAE v 3.0. Results: Median survival was 54 months (range, 26 to 77 months). The 5-year overall survival (OS) and disease free survival (DFS) rates were 45% and 38%, respectively. The number of metastatic lymph nodes was associated with overall survival (hazard ratio, 1.037; p-value=0.040). The 5-year locoregional recurrence free survival (LRFS) and distant metastasis free survival (DMFS) rates were 88% and 48%, respectively. Multiple stations of mediastinal lymph node metastasis was associated with decreased DFS and DMFS rates (p-value=0.0014 and 0.0044, respectively). Fifty-one relapses occurred at the following sites: 10 loco-regional, 41 distant metastasis. Grade 2 radiation pneumonitis was seen in three patients, and symptoms were well tolerated with anti-tussive medication. Grade 2 radiation esophagitis was seen in 11 patients. There were no grade 3 or more severe complications associated with PORT. Conclusion: Our retrospective data show that PORT for pathological stage III NSCLC is a safe and feasible treatment and could improve loco-regional control. The number of metastatic lymph nodes and stations of mediastinal lymph node metastasis were analyzed as prognostic factors. Furthermore, efforts are needed to reduce distant metastasis, which is a major failure pattern of advanced stage NSCLC.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.3
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• pp.71-76
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• 2017

The electrical behavior and flexibility of the screen printed Ag circuits were investigated with infrared radiation sintering times and sintering temperatures. Electrical resistivity and radio frequency characteristics were evaluated by using the 4 point probe measurement and the network analyzer by using cascade's probe system, respectively. Electrical resistivity and radio frequency characteristics means that the direct current resistance and signal transmission properties of the printed Ag circuit. Flexibility of the screen printed Ag circuit was evaluated by measuring of electrical behavior during IPC sliding test. Failure mode of the Ag printed circuits was observed by using field emission scanning electron microscope and optical microscope. Electrical resistivity of the Ag circuits screen printed on Pl substrate was rapidly decreased with increasing sintering temperature and durations. The lowest electrical resistivity of Ag printed circuit was up to $3.8{\mu}{\Omega}{\cdot}cm$ at $250^{\circ}C$ for 45 min. The crack length arisen within the printed Ag circuit after $10{\times}10^4$ sliding numbers was 10 times longer than that of after $2.5{\times}10^4$ sliding numbers. Measured insertion loss and calculated insertion loss were in good agreements each other. Insertion loss of the printed Ag circuit was increased with increasing the number of sliding cycle.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.553-558
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• 2004

Avoiding cardiopulmonary bypass (CPB) in coronary artery bypass grafting (CAB G) has been known to reduce early mortality and morbidity. Diabetes Mellitus is a significant risk factor for adverse early and late outcomes after CABG. We compared the clinical results of off-pump CABG versus on-pump CABG in diabetes patients. Material and Method: 682 patients (424 off-pump CABG and 258 on-pump CABG) underwent isolated coronary artery bypass grafting between January 2001 and June 2003. Data were collected 242 patient who had diabetes. Among them, 154 patients underwent off-pump CABG and 90 patients underwent on-pump CABG. We analyzed the preoperative risk factors and postoperative results between 2 groups. Result: Two groups did not show statistical differences in age, sex, coronary and operative risk factors. Operative time was significantly shorter in off-pump CABG, however, number of grafts was fewer in off-pump CABG. Postoperative inotropic usage was lower in off-pump CABG. Postoperative CK-MB level was lower in off-pump CABG, and ICU stay and ventilation time was significantly shorter in off-pump CABG. However, there was no statistical difference between 2 groups in operative mortality, reoperation rate, perioperative myocardial infarction, wound infection, renal failure, neurological complications and hospital stay. Conclusion: Off-pump CABG group showed less myocardial damage and early recovery. We concluded that off-pump CABG is the more reasonable technique in diabetes patients although two techniques showed good results. The long-term follow up and prospective study may be warranted.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.4
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• pp.330-333
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• 2009

Alveolar bone resorption after extraction impairs the necessary bone volume and complicates the case for implant surgery and aesthetic implant prosthesis. Immediate implant surgery after extraction decreases the number of surgical procedures and the duration of treatment, while allowing minimum alveolar bone resorption and preserving the residual bone volume. Although immediate implant holds many advantages such as preservation of hard and soft tissue around the extraction socket, greater implant survival rate and higher patient satisfaction, various complications and high failure rate are discouraging factors for the clinicians. In this case report, severe alveolar bone resorption with soft tissue changes were predicted after the extraction of prolonged retained deciduous incisors and impacted maxillary canines and thus decided on immediate implant procedure. Immediate implant surgery after extraction was carried out with minimal bone reduction and tapered wide-neck implant to establish initial stability. Simultaneous bone graft was done by filling the defect area with iliac cancellous bone with additional onlay-type bone graft and absorbable membrane on the labial bone for upper lip support. A stable and esthetic result was obtained with shortened treatment period.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6267-6272
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• 2015

Background: Extra nodal lymphoma (ENL) constitutes about 33 % of all non-Hodgkin's lymphoma. 18-28% develops in the head and neck region. A multimodality treatment with multi-agent chemotherapy (CT) and radiotherapy (RT) is considered optimum. Materials and Methods: We retrieved the treatment charts of patients of HNENL treated in our institute from 2001-2012. The charts were reviewed and the demographic, treatment details and outcome of HNENL patients were retrieved using predesigned pro-forma. Results: We retrieved data of 75consecutive patients HNENL. Median age was 47years (Range: 8-76 years). Of the 75 patients 51 were male and 24 were female. 55patients were evaluable. The patient and tumor characteristics are summarized in Table 1. All patients were staged comprehensively with contrast enhanced computed tomography of head, neck, thorax, abdomen, pelvis and bone marrow aspiration and biopsy 66 patients received a combination multi-agent CT with CHOP being the commonest regimen. 42 patients received 4 or lesser number of cycles of chemotherapy whereas 24received more than 4 cycles chemotherapy. Post radiotherapy, 41 out of 42 patients had a complete response at 3 months. Only 21patients had a complete response after chemotherapy. All patients received radiation (mostly involved field radiation) as a part of the treatment. The median radiation dose was 45 Gray (Range: 36 Gray-50 Gray). The radiation was planned by 2D fluoro simulation based technique in 37cases and by 3 Dimensional conformal radiation therapy (3DCRT) in 36 cases. Two patients were planned by the intensity modulated radiation therapy (IMRT) technique. IMRT was planned for one thyroid and one nasal cavity primary. 5 patients experienced relapse after a median follow up of 19 months. The median survival was not reached. The estimated two and three year survival were 92.9% (95%CI- 68.6- 95.35) and 88% (95%CI- 60.82 - 92.66) respectively. Univariate analysis revealed higher stage and poorer baseline performance status to be significantly associated with worse progression free survival. 5 patients progressed (relapse or primary disease progression) after treatment. Of the 5 patients, two patients were primary orbital NHL, two patients had NHL nasal cavity and one was NHL thyroid. Conclusions: Combined modality treatment in HNENL confers excellent disease control with acceptable side effects.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.1
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• pp.45-50
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• 2012

Thoracolumbar orthosis has been used for the rehabilitation of the patients with senile kyphosis. Recently, a number of different thoracolumbar orthosis designs have been introduced but its biomechanical effectiveness still remain unknown. In this study, we compared the pressure distribution on the surface of the trunk and stresses on the orthosis in relation to changes in connecting frame designs (Type 1, one-connecting frame type; Type 2, two-connecting frame type; Type 3, all-in-one type) using finite element (FE) models under different motions of the trunk. The results showed that Type 3 distributed the pressure on the trunk most evenly followed by Type 2 and Type 1 and the difference between Type 1 and Type 2 was negligible. ROM was limited most effectively by Type 3 ($8.5{\sim}9.4^{\circ}$), followed by Type 2 ($11.3{\sim}13.9^{\circ}$) and Type 1 ($12.1{\sim}15.4^{\circ}$). The ratio between the peak von Mises stress and yield strength of each material remained less than 20% regardless of orthosis type indicating low likelihood of component failure. In conclusion, our study found that all-in-one type of orthosis was the most effective design for the conservative treatment of spinal deformity in terms of function and comfort.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.217-223
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• 2005

The term 'impaction teeth' is used to designate a tooth which remains unerupted in jaw beyond the time at which it should normally be erupted. Most cases of impacted teeth reported in the literature are permanent teeth. The impaction of primary teeth occur rarely whereas impaction of second primary molars is more numerous than all other impactions. Failure of eruption of primary teeth may cause a number of complications, such as interference with development and eruption of successive permanent teeth, malocclusion, cystic change of tooth follicle. The clinican should consider the various treatment option available (a) No treatment and observation, (b) surgical extraction (c) space regainer. Proper treatment plan should be established after thought consideration of impacted tooth and it's relation with successive permanent tooth.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.588-592
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• 2012

To examine the reason of empty samara production of Chinese elm, Ulmus parviflora, twenty two planted trees in Wonju-si were monitered for three years in terms of their flowering, pollinatiom system and samara characteristics. Inflorescences with bisexual flowers of Chinese elm are developed in the leaf axils on the twigs. Dichogamous flowers are varied with protogynuous and protandrous flower, and stamens in some bisexual flowers are developed in seperated time on a inflorescence or a tree. It is revealed newly that the flower of Chinese elm is out-crossed and partially insect(Apis mellifera) pollinated. The ratios of sound samara are significantly differed among years, the heighest values 65.5% were shown in 2009, lowered 42.9% in 2010, and the lowest 37.5% in 2011. This result might be affected by mean daily precipitation and number of rainy days during the flowering date, and lower temperature during the floral initiation stage, especially in 2011. These findings suggest that Chinese elm has self-incompatibility strategy and much pollination failure resulted in a production of much empty samaras. Further researches on the empty-seed production strategies and pollination system of major tree species might be needed.