전류변성기의 비오차와 위상오차의 절대 평가 기술 金潤亨(Yoon-Hyoung Kim); 鄭在甲(Jae-Kap Jung); 韓相吉(Sang-Gil Han) ...
전기학회 논문지 P권, 57(2),
2008, Letnik:
57P, Številka:
2
Journal Article
Odprti dostop
We have developed an absolute evaluation method to obtain the ratio error and phase displacement of a current transformer (CT) without any precise standard CT by measuring four parameters in a CT ...equivalent circuit. The excitation admittance in the CT equivalent circuit can be obtained by employing standard resistors with negligible reactive component. The secondary leakage impedance in the CT equivalent circuit can be measured using a universal impedance bridge. The method was applied to CTs under test with the wide current ratios in the range of 5 A / 5 A - 5,000 A / 5 A and 5 A / 1 A - 5,000 A / 1 A. The ratio error and phase displacement of the CT under test obtained in this study are consistent with those measured at the national institute in Canada using the same CT under test within an expanded uncertainty (k = 2) in the overall current ratios.
AIDS is one of the greatest infectious disease threats to human health despite the extensive efforts made since the discovery of HIV in 1983. The use of plasmid DNA vaccination to elicit humoral and ...cell-mediated immune responses against HIV infection has produced promising results in animal and in human trials. However, there are several safety concerns about the use of a DNA vaccine, which include the possibility of integration into the host genome, adverse immunopathology, and anti-DNA autoantibody induction. In this study, we examined the potential integration and distribution of GX-12, a new therapeutic vaccine for HIV infection, at various times in muscles and reproductive organs of rats. Animals of both sexes were injected with GX-12 at the dose of 400 microg/animal i.m. once a week for 4 weeks, and host genome integration and tissue distribution were examined on day 1, 5, 15, 30 and 45 days after the final injection. A PCR-based assay revealed that GX-12 was not integrated into the host genome, nor expressed in reproductive organs at any time. These findings suggest that the risk of mutation or germline transmission due to GX-12 injection is negligible.
Hyperdynamic circulation due to reduced peripheral vascular resistance and increased cardiac output, and the development of portal hypertension are the hemodynamic changes observed in patients with ...liver cirrhosis. Such hemodynamic abnormalities appear in patients with late stage liver cirrhosis. Therefore, hemodynamic indices, which represent hyperdynamic circulation and portal hypertension, are significant for the prognosis of patients with liver cirrhosis. The aim of this study was to determine the hemodynamic indices associated with the prognosis of patients with liver cirrhosis.
A total of 103 patients diagnosed with liver cirrhosis between December 1999 and June 2003, with a mean follow-up period of 73 weeks, ranging from 7 to 168 weeks, were recruited. Using Child-Pugh classification, the mean arterial pressure, heart rate and hepatic venous pressure gradient (HVPG) were measured. The indices of Doppler ultrasonography, including the portal and splenic venous flows, and the resistance of the hepatic, splenic, and renal arteries were also measured using the arterial pulsatility index (PI). The prognostic values of these indices were determined by their comparison with the patient survivals.
Significant hemodynamic indices for a bad prognosis were high HVPG (> or = 15 mmHg) and renal arterial PI (> or = 1.14)(p<0.05). A Child-Pugh score > or = 10 was important for a poor prognosis (p<0.05).
Severe portal hypertension (HVPG > or = 15 mmHg) and high renal arterial resistance (PI +/- 1.14) were valuable hemodynamic indices for the prognosis of patients with liver cirrhosis. Therefore, it was concluded that the measurement of these hemodynamic indices, in addition to the Child-Pugh classification, is helpful in the prognosis of patients with liver cirrhosis.
Deoxycholic acid (DCA), a secondary bile acid, has been implicated to promote colon cancer growth and progression. However, its molecular mechanisms are largely unknown. In this study, we ...investigated the effects of DCA on proliferation, migration, and invasiveness of colon cancer cells (HT-29).
HT-29 cells were incubated with either medium (control) only or DCA for 24-48 hours. Time courses of RT-PCR for vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF)-1alpha mRNA expression, Western blotting for VEGF and matrix metalloproteinase (MMP)-9, zymography for MMP-9 activation, and wound-migration assay were determined after various concentrations of DCA (0-80 microM) treatment. Moreover, these experiments were reassessed after pretreatments (2-6 hours) with specific inhibitors of various signal pathways.
DCA enhanced HIF-1alpha mRNA expression, VEGF mRNA and VEGF protein expression, MMP-9 protein expression/activation, and cell migration ability in a dose-related manner. DCA-induced VEGF protein expression was inhibited by pretreatment with NS-398 (COX-2 inhibitor), PDTC (NF-kappaB inhibitor), or tauroursodeoxycholic acid (TUDC). DCA-induced cell migration ability was inhibited by pretreatment of GF109203X, a protein kinase C inhibitor. DCA-induced MMP-9 protein expression/activation was inhibited by pretreatment with SB203580, U0126, or PDTC.
DCA significantly upregulates invasive and angiogenic potentials of human colon cancer cells through multiple signal transduction pathways.
관상동맥폐색질환에 따른 대장 종양의 유병률과 위험인자 석기태; Ki Tae Suk; 김현수 ...
Intestinal research,
09/2011, Letnik:
9, Številka:
2
Journal Article
Recenzirano
목적: 대장 종양과 관상동맥폐색질환은 국내에서 모두 유병율이 높아 주된 사망의 원인이 된다. 남성, 흡연, 고지혈증, 당뇨, 그리고 비만과 같은 위험인자들을 공유하고 있지만, 관상동맥폐색질환에 따른 대장종양의 유병률에 대한 보고는 거의 없다. 따라서, 저자들은 이 연구에서 대장 종양과 관상동맥폐색질환 간의 임상적 연관성을 조사하였다. 대상 및 방법: ...2003년 5월부터 2007년 12월까지 대장내시경검사 전후에 관상동맥 조영술을 시행한 176명(남자: 101명, 평균나이: 62.1±9.7세)의 환자들을 후향적으로 조사하였다. 관상동맥 폐색질환(정상, 경도의 관상동맥폐색질환, 또는 관상동맥폐색질환)의 중등도에 따른 대장내시경 검사소견(정상, 선종, 또는 암)과 임상 및 혈액학 검사자료를 비교분석하였다. 결과: 정상, 경도의 관상동맥 폐색질환, 그리고 관상동맥폐색질환 환자는 각각 36명, 40명, 그리고 100명이었다. 정상 관상동맥, 경도의 관상동맥 폐색질환 환자, 그리고 관상동맥폐색질환 환자에서 대장 종양(선종과 대장암)의 유병률은 각각 42%, 48%, 63%이어 각 군별로 통계학적으로 차이를 보였다(P＜0.05). 다변량 분석에서 고령(≥60세; P=0.03, Odds ratio 2.47)과 관상동맥 폐색질환의 존재(P=0.02, Odds ratio 4.11)는 대장 신생물의 위험인자였다. 결론: 관상동맥폐색질환의 경중도에 비례하여 대장 종양의 유병률이 증가하였다. 따라서 관상동맥 폐색질환을 가진 환자 특히, 고령의 환자에서는 대장암의 선별을 위한 대변 잠혈검사나 대장내시경검사가 우선적으로 시행되어야 한다.
Background/Aims: Both colorectal neoplasm (CN) and coronary artery obstructive disease (CAOD) are prevalent and major leading causes of death in Korea. Although CN and CAOD share similar risk factors such as male gender,smoking, hyperlipidemia, diabetes mellitus, and obesity, few studies of both CN and CAOD have been reported. In this study, we evaluated clinical correlations between CN and CAOD. Methods: Between June 2003 and December 2007, 176 patients (Male: 101, average age: 62.1±9.7 yr) who underwent colonoscopy after or before coronary angiography were retrospectively enrolled. The colonoscopic findings (normal, adenoma, or cancer) of patients as well as clinical and laboratory data according to the extent of CAOD (normal, minimal CAOD, or CAOD) were compared. Results: CAOD negative, minimal CAOD, and CAOD patients totaled 36, 40, and 100, respectively. The presence of CN (adenoma and adenocarcinoma) in CAOD negative, minimal CAOD, and CAOD cases was 42%,48%, and 63%, respectively, which was significantly different (P＜0.05). In multivariate analysis, old age (≥60yr; P=0.03, odds ratio 2.47) and the presence of CAOD (P=0.02, odds ratio 4.11) were associated with the presence of CN. Conclusions: The prevalence of CN increased in proportion to the severity of CAOD. Colorectal cancer screening by fecal occult blood tests or colonoscopy should be a priority in patients with CAOD, particularly the elderly. (Intest Res 2011;9:112-116)
Background The aim of this study was to assess the impact of more aggressive pharmacological treatment on short-term clinical outcomes in patients with acute non ST-segment elevation myocardial ...infarction (NSTEMI) who do not undergo percutaneous coronary intervention (PCI). Methods and Results The 924 NSTEMI patients treated with early conservative strategy (69.2±12.5 years, 637 males) in 50 hospitals that were high-volume centers with facilities for primary PCI were recruited to the Korean Acute Myocardial Infarction Registry (KAMIR) from November 2005 to August 2007. For all patients, the pharmacotherapy index based on the use of drugs during hospital stay was assessed (range of points 0-10). Primary endpoint was the combined in-hospital mortality and morbidity and major adverse cardiac events during 1 month of clinical follow-up. Of the patients, data from 847 who were followed-up for 1 month after discharge were analyzed. The rate of the primary endpoint decreased with an increase of the pharmacotherapy index and this result was similar in the low- and high-risk groups. In the multivariate analysis, low pharmacotherapy index (≤4 points) was an independent predictor of the primary endpoint. Conclusions More intensive pharmacological treatment may improve short-term clinical outcomes in acute NSETMI patients who do not undergo PCI. (Circ J 2008; 72: 1403 - 1409)
Background/Aims: Propranolol can prevent variceal bleeding by ameliorating portal hypertension. We conducted this study to determine the effect of propranolol on portal hypertension and the optimal ...required dose in Korean cirrhotic patients. Methods: This study prospectively evaluated 50 patients with cirrhosis who exhibited variceal bleeding. The hepatic venous pressure gradient (HVPG), portal venous flow, heart rate (HR), and blood pressure were assessed both at baseline and at 3 months after the treatment. The initial dose of propranolol (20 mg) was subsequently adjusted until the target HR was reached. Patients in whom HVPG reduced by ＞20% or to less than 12 mmHg were defined as responders. Results: Propranolol significantly (p＜0.01) reduced the HVPG (-21±26%, mean±standard deviation), portal venous flow (-25±21%), HR (-20±13%), and blood pressure (-3±13%). Twenty-nine patients were responders, and the optimal required dose was 154.4 mg. The main complication was dizziness (24%), but this was not serious enough to require medication withdrawal. Conclusions: Propranolol is safe and effective at reducing portal pressure in Korean cirrhotic patients. An effective improvement in portal hypertension requires the dose to be increased until the target HR is reached. (Gut and Liver 2007;1:159-164)
Background/Aims: Propranolol can prevent variceal bleeding by ameliorating portal hypertension. We conducted this study to determine the effect of propranolol on portal hypertension and the optimal ...required dose in Korean cirrhotic patients. Methods: This study prospectively evaluated 50 patients with cirrhosis who exhibited variceal bleeding. The hepatic venous pressure gradient (HVPG), portal venous flow, heart rate (HR), and blood pressure were assessed both at baseline and at 3 months after the treatment. The initial dose of propranolol (20 mg) was subsequently adjusted until the target HR was reached. Patients in whom HVPG reduced by ＞20% or to less than 12 mmHg were defined as responders. Results: Propranolol significantly (p＜0.01) reduced the HVPG (-21±26%, mean±standard deviation), portal venous flow (-25±21%), HR (-20±13%), and blood pressure (-3±13%). Twenty-nine patients were responders, and the optimal required dose was 154.4 mg. The main complication was dizziness (24%), but this was not serious enough to require medication withdrawal. Conclusions: Propranolol is safe and effective at reducing portal pressure in Korean cirrhotic patients. An effective improvement in portal hypertension requires the dose to be increased until the target HR is reached. (Gut and Liver 2007;1:159-164)
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