방사선 조사선량에 따른 백서 악하선의 caspase-3 발현양상

권기정,최용석,황의환,이상래,고광준 대한구강악안면방사선학회 2006 Imaging Science in Dentistry Vol.37 No.1

Purpose : To investigate the caspase-3 expression in the acinar and ductal cells of rat submandibular glands after the irradiation of various doses. Materials and Methods: The male Sprague-Dawley rats weighing approximately 250 gm were used for this study. The experimental group was irradiated with a single absorbed dose of 2, 5, 10, and 15 Gy on the head and neck region. The rats were sacrificed on the 1st, 3rd, 7th, 14th, 21st, and 28th day after irradiation. The specimens including the submandibular gland were sectioned and observed using histopathological and immunohistochemical methods. Results : The local destruction of the acinar and ductal cells and the karyopyknotic nuclei of the acinar cells were observed in the 2 Gy and 5 Gy irradiation groups later than in the 10 Gy and 15 Gy irradiation groups. And the expression of caspase-3 was prominent only in the ductal cells in the 2 Gy and 5 Gy irradiation groups. Conclusion : This experiment suggests that radiation-induced apoptosis in the ductal cells of rat submandibular glands was induced by a low dose radiation associated with the activation of caspase-3 and radiation-induced necrosis was induced by a high dose radiation. (Korean J Oral Maxillofac Radiol 2006; 36 : 7-15)

스위치드 릴럭턴스 전동기의 토오크 리플 저감을 위한 폴 형상 최적화

최용권,윤희성,황인성,고창섭 충북대학교 컴퓨터정보통신 연구소 2006 컴퓨터정보통신연구 Vol.14 No.1

최근 스위치드 릴럭턴스 전동기(Switched Reluctance Motor)는 고효율, 안정성, 용이한 가변 속도, 그리고 유지 보수의 불필요성 등의 장점으로 인하여 산업의 많은 분야에서 사용이 증대되고 있다. 그러나 SRM은 고정자와 회전자가 모두 돌극(Saliency) 구조를 이루며 펄스 형태의 여자 방식으로 구동되기 때문에 소음과 진동의 원인이 되는 토오크 리플이 크다는 단점을 갖는다. 토오크 리플 저감을 위한 기존의 연구는 주로 턴온 각 (θ_(on))과 턴오프 각 (θ_(off))조정, 고정자 극호(β_(s)) 그리고 회전자 극호 (β_(r))를 조정하는데 초점을 두었다. 그러나 고속 구동 시에는 여자 전류의 확립을 위한 충분한 시간이 필요하므로 스위칭 각도를 조정하여 토오크 리플을 저감하는 방법에는 한계가 있다. 따라서 본 논문은 턴온 각, 턴오프 각, 고정자 극호, 그리고 회전자 극호가 고정되어 있는 경우 고정자 돌극의 형상 변화를 통한 토오크 리플 저감법을 제안하고 반응표면법(Response Surface Methodology)을 이용하여 최적화를 수행하였다. Recently the switched reluctance motor(SRM) is highly expected to have more and more growing applications because it has many advantages over the other type motors such as high torque/weight ratio, robustness, easy variable speed and less maintenance. However, the SRM has large torque ripple which is caused by the excitation method of the pulse waveform and the saliency of both the stator and the rotor. The prior researches on the reduction of torque ripple are mainly focused on optimizing the switching angle, stator pole arcs, and rotor pole arcs. In high speed operation, however, it has a limitation to control the switching angle for the reduction of torque ripple because enough time is required in the establishment of exciting current. This paper shows that the torque ripple can be successfully minimized by optimizing the shape of the stator pole without controlling the switching time, stator pole arcs and rotor pole arcs.

하지의 동맥부전증 환자에서 동반된 복부 대동맥류

문인성,박장상,고용복,김용귀,홍성곤,김승남 대한혈관외과학회 1999 Vascular Specialist International Vol.15 No.1

The early diagnosis of abdominal aortic aneurysms are difficult, especially when they are not clinically evident. Because of the generalized nature of atherosclerosis, there is reason to believe that there is a high incidence of aneurysms of the abdominal aorta in patients with peripheral vascular disease. But the screening test for hidden abdominal aortic aneurysms in patients with peripheral arterial disease has not been used for routine manner. So we retrospectively reviewed the 9 patients who had asymptomatic abdominal aortic aneurysms with symptomatic peripheral arterial disease during the last four and half-year period: among them three aneurysms were screened preoperatively by physical examination with their diameter more than 5 cm and 6 aneurysms were found intraoperatively with their mean diameter of 3.8cm. The ages ranged from 66 through 84 years with the mean age 73 years. There were 7 men and 2 women. The sites of the peripheral occlusive disease is as follows: femoral artery only in 1, iliac artery only in 2, both iliac and femoral arteries in 5, and from iliac artery through tibial artery with thrombus formation in 1. We suggest that ultrasonographic screening for the presence of hidden abdominal aortic aneurysm preoperatively in patients with lower extremity occlusive arterial disease is needed, especially when the ages of patients is older than 65 years and the site of arterial disease include iliac segment.

경피적 자궁동맥 색전술로 치료한 산후 출혈 1례

정명철,김호성,김경철,노지현,고재환,김용봉,권동일 白中央醫療院 2005 仁濟醫學 Vol.26 No.1

Postpartum hemorrhage remains one of the leading causes of maternal deaths. The major causes of postpartum hemorrhage include uterine atony, retained placental fragment, placenta accreta, and lower genital tract lacerations. Conservative treatment is based on administration of uterotonic drugs, vaginal packing, and surgical repair of genital tract lacerations. When bleeding fails to respond to conservative treatment, surgical ligation of uterine vessels or hemostatic hysterectomy is performed. We present a case of postpartum bleeding treated by selective uterine arterial embolization with a brief review of previous literatures of postpartum hemorrhage & uterine arterial embolization.

Hydrochemistry, Origin and Residence time of Deep Groundwater in the Yuseong area

Yong-Kwon Koh,Geon-Young Kim,Dae-Seok Bae,Kyung-Woo Park 한국방사성폐기물학회 2005 한국방사성폐기물학회 학술논문요약집 Vol.3 No.1

The Role of Ballooning in Patients with Post-tuberculosis Bronchial Stenosis

Kwon, Yong Soo,Kim, Hojoong,Kang, Kyung Woo,Koh, Won Jung,Suh, Gee Young,Chung, Man Pyo,Kwon, O Jung The Korean Academy of Tuberculosis and Respiratory 2009 Tuberculosis and Respiratory Diseases Vol.66 No.6

Background: In order to access the role of ballooning in patients with post-tuberculosis bronchial stenosis (PTBS), medical records of patients who underwent the procedure were reviewed. Methods: Twenty-nine PTBS patients underwent balloon dilatation between May 1999 and November 2000 at Samsung Medical Center. The median age was 28 (range 16~62 year) and most patients were female (n=27, 93%). The mean number of ballooning procedures was 2.4 (range 1~8) and the interval between ballooning procedures was 76.2$\pm$69.7 days. Results: In general, the $FEV_1$ was improved after ballooning (from 66.2.$\pm$11.9% predicted to 73.5$\pm$13.0% predicted, p=0.0004). Among 29 patients who underwent ballooning, a clinically successful outcome was observed in 16 patients (55%). Comparison between the successful and unsuccessful groups showed that favorable factors for a successful outcome were a higher pre-9ballooning $FEV_1$ (71.1$\pm$8.1 vs. 60.2$\pm$13.3% predicted), higher post-9ballooning $FEV_1$ (89.2$\pm$7.8 vs. 63.4$\pm$9.2% predicted) and absence of left upper lobe collapse. The clinical outcome was unsuccessful in all eight patients with a pre-9ballooning $FEV_1$ $\leq$57% of predicted or with complete left upper lobe collapse. Conclusion: In conclusion, ballooning appears to be helpful in patients with PTBS, especially when the pre-ballooning $FEV_1$ >57% of predicted and there is no complete left upper lobe lung collapse.

Basal Serum Cortisol Levels are not Predictive of Response to Corticotropin but Have Prognostic Significance in Patients with Septic Shock

Kwon, Yong Soo,Suh, Gee Young,Kang, Eun-Hae,Koh, Won-Jung,Chung, Man Pyo,Kim, Hojoong,Kwon, O Jung KOREAN ACADEMY OF MEDICAL SCIENCE 2007 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.22 No.3

<P>Because high levels of cortisol are frequently observed in patients with septic shock, low levels of serum cortisol are considered indicative of relative adrenal insufficiency (RAI). This study was performed to investigate whether pretest clinical characteristics, including basal serum cortisol levels, are predictive of serum cortisol response to corticotropin and whether basal cortisol levels have a prognostic significance in patients with septic shock. We performed a retrospective analysis of 68 patients with septic shock who underwent short corticotropin stimulation testing. RAI was defined as an increase in cortisol level <9 µg/dL from baseline, and results showed that 48 patients (70.6%) had this insufficiency. According to the univariate analysis, the RAI group had significantly higher simplified acute physiology score II (SAPS II) and sequential organ failure assessment (SOFA) scores than the non-RAI group. The incidence of RAI was the same regardless of the basal serum cortisol level (<I>p</I>=0.447). The hospital mortality rate was 58.8% and was not significantly different between the RAI and non-RAI groups. However, a high basal serum cortisol level (≥30 µg/dL) was significantly associated with in-hospital mortality. In conclusion, our data suggest that basal serum cortisol levels are not predictive of serum cortisol response to corticotropin but have a significant prognostic value in patients with septic shock.</P>

Geochemical evolution of groundwater of the Cheongyang area, Korea

Yong Kwon Koh,Geon Young Kim,Si-Won Yoo 대한지질학회 2007 대한지질학회 학술대회 Vol.2007 No.0

Hepatitis C Virus Infection and Hepatotoxicity During Antituberculosis Chemotherapy

Kwon, Yong Soo,Koh, Won-Jung,Suh, Gee Young,Chung, Man Pyo,Kim, Hojoong,Kwon, O. Jung American College of Chest Physicians 2007 Chest Vol.131 No.3

<P>BACKGROUND: The risk of drug-induced hepatotoxicity (DIH) during treatment for tuberculosis (TB) in patients who are seropositive for the hepatitis C virus (HCV) is not clear. We evaluated whether HCV-seropositive patients are at a higher risk of DIH than control subjects during treatment for TB with standard short-course regimens. METHODS: Fifty-four HCV-seropositive patients with newly diagnosed active TB who were treated with isoniazid, rifampin, ethambutol, and/or pyrazinamide were included in the study population. Ninety-seven HCV-seronegative patients were selected as control subjects. RESULTS: Forty HCV-seropositive patients (74%) and 82 control subjects (85%) received an initial treatment regimen that included pyrazinamide. Twenty-two HCV-seropositive patients (41%) and 19 control subjects (20%) exhibited elevated liver enzyme levels during TB treatment, including transient elevation of transaminase. DIH, defined as a liver transaminase level >/= 120 IU/L, occurred more frequently in HCV-seropositive patients (7 of 54 patients, 13%) than in control subjects (4 of 97 patients, 4%). Isoniazid and rifampin were reintroduced after the liver transaminase level returned to baseline in five HCV-seropositive patients exhibiting DIH, and all these retrials proved to be successful. CONCLUSIONS: These findings suggest that treatment for TB in HCV-seropositive patients could be pursued in the usual manner, using standard short-course regimens, with the condition that monthly liver function tests are carefully performed.</P>

The Role of Ballooning in Patients with Post-tuberculosis Bronchial Stenosis

( Yong Soo Kwon ),( Ho Joong Kim ),( Kyung Woo Kang ),( Won Jung Koh ),( Gee Young Suh ),( Man Pyo Chung ),( O Jung Kwon ) 대한결핵 및 호흡기학회 2009 Tuberculosis and Respiratory Diseases Vol.66 No.6

Background: In order to access the role of ballooning in patients with post-tuberculosis bronchial stenosis (PTBS), medical records of patients who underwent the procedure were reviewed. Methods: Twenty-nine PTBS patients underwent balloon dilatation between May 1999 and November 2000 at Samsung Medical Center. The median age was 28 (range 16~62 year) and most patients were female (n=27, 93%). The mean number of ballooning procedures was 2.4 (range 1~8) and the interval between ballooning procedures was 76.2±69.7 days. Results: In general, the FEV1 was improved after ballooning (from 66.2.±11.9% predicted to 73.5±13.0% predicted, p=0.0004). Among 29 patients who underwent ballooning, a clinically successful outcome was observed in 16 patients (55%). Comparison between the successful and unsuccessful groups showed that favorable factors for a successful outcome were a higher pre-ballooning FEV1 (71.1±8.1 vs. 60.2±13.3% predicted), higher post-ballooning FEV1 (89.2±7.8 vs. 63.4±9.2% predicted) and absence of left upper lobe collapse. The clinical outcome was unsuccessful in all eight patients with a pre-ballooning FEV1 ≤57% of predicted or with complete left upper lobe collapse. Conclusion: In conclusion, ballooning appears to be helpful in patients with PTBS, especially when the pre-ballooning FEV1 >57% of predicted and there is no complete left upper lobe lung collapse.