• Title/Summary/Keyword: dose-rate

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Change of Pulmonary Artery Hemodynamics and Pulmonary Vascular Resistance in Experimental Pulmonary Embolism (실험적 급성 폐색전증에서 폐동맥혈역학 및 폐혈관저항의 변화)

  • Chung, Hee-Soon;Lee, Jae-Ho;Kim, Cheol-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.6
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    • pp.913-922
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    • 1995
  • Background: When we define the pressure of pulmonary vasculature in which a recruitment of blood flow occurs as $P_I$ and the proportion of change in pulmonary artery to that in cardiac output as IR and then we compare PI and IR with pulmonary vascular resistance, we would find some problems in pulmonary vascular resistance. In other words, it is the theory that, IR should be increased mainly in pulmonary embolism in which decreases the cross sectional area of pulmonary vasculature. But there are many contradictory reports resulted from various researches and the fact is known widely that any difference exists between PVR and PI, IR. For this reason, the purpose of this study is to observe how PI and IR change at the time of the outbreak and during treatment of the pulmonary embolism, and to find out the meaning of these new indicators and the difference from the pulmonary vascular resistance used generally when we subdivide the pulmonary vascular resistance into PI and IR. Method: After making AV fistula in experimental dog, we controlled cardiac output at the intervals of 15 minute in case of three kinds(all AV fistula are obstructed, only one of fistula is open and all of fistula is open), and after evoking massive pulmonary embolism with radioactive autologous blood clots, we measured the mean pulmonary artery pressure, and calculated PI and IR. We observed the pattern of change in PI and IR, without giving the control group any specific treatment and with injecting intravenously rtPA in the Group 1 and Group 2 at the dose of 1mg per kg, for 15 minutes fot the former and 3 hours for the latter. Result: 1) Pulmonary vascular resistance showed a change similar to that of pulmonary artery pressure and in all three group, PVR increased significantly, but group 1 and group 2 showed tendency that PVR keeps on decreasing after treatment, and the rate of decrease in group 1 is more rapid than group 2 significantly. 2) Both intersection(PI) and degree(IR) are proved statistically significant, in view of the straight line relationship between cardiac output and pulmonary artery pressure, calculated by minimal regression method. 3) PI changed similarly to pulmonary vascular resistance, while in the IR which is theoretically more similar to PVR, there was no significant difference or change after rtPA infusion. Conclusion: In the pulmonary embolism, Both change in IR which means real resistance of pulmonary vasculature and PI which was developed due to secondary vasoconstriction by pulmonary embolism are reflected same time.

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Apoptotic Effects and Cell Cycle Arrest Effects of Extracts from Cnidium monnieri (L.) Cusson through Regulating Akt/mTOR/GSK-3β Signaling Pathways in HCT116 Colon Cancer Cells (HCT116 대장암세포에서 AKT/mTOR/GSK-3β 신호경로 조절을 통한 벌 사상자 추출물(CME)의 apoptosis 및 cell cycle arrest 효과)

  • Lim, Eun Gyeong;Kim, Guen Tae;Kim, Bo Min;Kim, Eun Ji;Ha, Sung Ho;Kim, Sang-Yong;Kim, Young Min
    • Journal of Life Science
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    • v.26 no.6
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    • pp.663-672
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    • 2016
  • The Cnidium monnieri (L.) Cusson is an annual plant distributed in China and Korea. The fruit of C. monnieri is used as a medicinal herb that is effective for the treatment of carbuncle and pain in female genitalia. However, the anti-cancer effects of CME have not yet been reported. In this study, we assessed the apoptotic effects and cell cycle arrest effects of ethanol extracts from C. monnieri on HCT116 colon cancer cells. The results of an MTT assay and LDH assay demonstrated a decrease in cell viability and the cytotoxic effects of CME. In addition, the number of apoptotic body and the apoptotic rate were increased in a dose-dependent manner through Hoechst 33342 staining and Annexin V-PI double staining. In addition, cell cycle arrest occurred at the G1 phase by CME. Protein kinase B (Akt) plays an important role in cancer cell survival, growth, and division. Akt down-regulates apoptosis-mediated proteins, such as mammalian target of rapamycin (mTOR), p53, and Glycogen Synthase kinase-3β (GSK-3β). CME could regulate the expression levels of p-Akt, p-mTOR, p-GSK-3β, Bcl-2 family members, caspase-3, and PARP. Furthermore, treatment with CME, LY294002 (PI3K/Akt inhibitor), BIO (GSK-3β inhibitor), and Rapamycin (mTOR inhibitor) showed that apoptotic effects occurred through the regulation of the AKT/mTOR/GSK-3β signaling pathway. Our results demonstrated CME could induce apoptosis and cell cycle arrest in HCT116 colon cancer cells.

Effect of Thyroid Hormone on the Electrical Activity of Rabbit Heart (토끼심장의 전기적 활동에 대한 갑상선 호르몬의 영향)

  • Hong, Seong-Geun;Kwun, Jong-Kuk;Chung, Soon-Il
    • The Korean Journal of Physiology
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    • v.20 no.1
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    • pp.17-29
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    • 1986
  • The present study was carried out to observe the effect of triiodothyronine on heart, one of the target organ of thyroid hormone. There are many reports that tachycardia, arrythmia, and agumentation of sodium, potassium pump activity are caused in hyperthyroid animal. To examine these cardiac positive chronotropic effects on sinoatrial (SA) node and atrial muscle, hyperthyroid state was induced experimentally by the injecion of 3,3',5-1-triiodothyronine $(T_3)$ in $3{\sim}6$ month-old rabbits. Then intracellular recordings by inserting glass microelectrode into cell were obtained in SA node and atrial muscle. The results can be summarized as follows : 1) Heartbeat was increased from $169.6{\pm}28.0\;to\;264.2{\pm}18.0$ beats per minute, while body weight was decreased to 68f of the initial body weight (Day 1). 2) In experimental group, the duration of action potential at 80% repolarization was decreased from $148.0{\pm}29.1\;to\;107{\pm}13.6msec$. This suggested the increase heartbeat. 3) The firing rate in hyperthyroid group markedly reduced under the 15 mM potassium Tyrode (p<0.005). 4) In hyperthyroid group, depolarization of atrial muscle cell was lowered significantly in 15 mM (p<0.05), 20 mM (p<0.05) potassium Tyrode solution. 5) Sodium-potassium pump activities in experimental group were higher than those in control group in both SA node (p<0. 1) and atrial muscle (p<0.025). 6) In lower concentration of $MnCl_2$, the excitability of SA node in hyperthyroid group was decreased more than that in control group. Effective inhibitory dose $(ID_{50})$ as 0.6 mM in hyperthyroid statd and 1.1 mM in control group.

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Effects of Dietary Taurine on the Lipid Metabolism in Laying Hens (사료내 타우린 첨가가 산란계의 지방대사에 미치는 영향)

  • 박강희
    • Korean Journal of Poultry Science
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    • v.29 no.2
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    • pp.95-100
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    • 2002
  • Two experiments were conducted to investigate the effect of taurine supplementation on lipid metabolism in laying hens. In experiment 1, 19-wk-old laying hens were given one of four taurine supplemented diets (0 (control), 0.4, 0.8, and 1.2% taurine) fur 10 weeks. Abdominal fat weight was lower in the 1.2% diet by 29.2% compared to the control. Serum concentrations of triacylglycerol and HDL-cholesterol were not different among the treatments. However, seam concentration of total cholesterol was higher by 22.4% in the 1.2% diet compared to the control. Concentration of triacylglycerol or total cholesterol in the liver were decreased by 26.1% or 26.4% and 28.2% or 26.4%, respectively in the 0.8% and 1.2% diets compared to the control. The concentration of HDL-cholesterol in liver was also lower by 33.9% in the 1.2% diet compared to the control. In experiment 2, 81-wk-old laying hens were allocated to one of three taurine supplemented diets (0 (control), 1 and 2% taurine) fur 6 weeks. Abdominal fat weight was lower by 25% in 1% taurine supplementation compared to the control. Serum concentrations of triacylglycerol, total cholesterol and HDL-cholesterol of hens fed with 1% diet were not different from those of control group. However, sew concentrations of triacylglycerol and total cholesterol were lower by 44.0% and 19.8%, respectively in the 2% diet compared to the control. Furthermore, serum concentration of HDL -cholesterol in the 2% diet was higher by 75% compared to the control. Concentrations of triacylglycerol and total cholesterol in the liver in the 2% diet were decreased in the 1% diet by 36.8 and 23%, respectively, but increased by 78.4% and 70%, respectively, compared to the control. The concentration of HDL-cholesterol in the liver was not different between the 1% diet and the control, but higher by 62.8% in the 2% diet compared to the control. These results indicated that taurine supplementation decreased the fat storage in abdominal cavity, which was accompanied by the changes in triacylglycerol and cholesterol metabolisms of laying hens.

Treatment Outcome of Thymic Epithelial Tumor: Prognostic Factors and Optimal Postoperative Radiation Therapy (흉선상피종의 치료 성적: 예후 인자 및 방사선치료 방법에 대한 연구)

  • Oh Dong Ryul;Ahn Yong Chan;Kim Kwan Min;Kim Jhingook;Shim Young Mog;Han Jung Ho
    • Radiation Oncology Journal
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    • v.23 no.2
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    • pp.85-91
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    • 2005
  • Purpose : This study was conducted to analyze treatment outcome and prognostic significance of World Health Organization (WHO)-defined thymic epithelial tumor (TET) subtype and to assess optimal radiation target volume in patients receiving surgery and adjuvant radiation therapy with TET. Materials and Methods: The record of 160 patients with TET, who received surgical resection at the Samsung medical Center, from December 1994 to June 2004, were reviewed. 99 patients were treated with postoperative radiation therapy (PORT). PORT was recommended when patients had more than one findings among suspicious Incomplete resection or positive resection margin or Wasaoka stage $II\~IV$ or WHO type $B2\~C$. PORT peformed to primary tumor bed only with a mean dose of 54 Gy. The prognostic factor and pattern of failure were analyzed retrospectively. Results : The overall survival rate at 5 years was $87.3\%$. Age (more than 60 years $77.8\%$, less than 60 years $91.1\%$; p=0.03), Wasaoka stage (I $92.2\%$, II $95.4\%$, III $82.1\%$, IV $57.5\%$; p=0.001), WHO tumor type (A-Bl $96.0\%$, B2-C $82.3\%$; p=0.001), Extent of resection (R0 resection $92.3\%$, R1 or 2 resection $72.6\%$, p=0.001) were the prognostic factors according to univariate analysis. But WHO tumor type was the only significant prognostic factor according to multivariate analysis. Recurrence was observed in 5 patients of 71 Masoka stage I-III patients who received grossly complete tumor removal (R0, R1 resection) and PORT to primary tumor bed. Mediastinal recurrence was observed In only one patients. There were no recurrence within irradiation field. Conclusion : WHO tumor type was the important prognostic factor to predict survival of patients with TET. This study suggest that PORT to only primary tumor bed was optimal. To avoid pleura- or pericardium-based recurrence, further study of effective chemotherapy should be investigated.

Understanding the Response Characteristics of X-ray Verification Film (X-선 Verification 필름의 반응 특성에 관한 연구)

  • Yeo Inhwan;Seong Jinsil;Chu Sung Sil;Kim Gwi Eon;Suh Chang Ok;Burch Sandra E.;Wang Chris K.
    • Radiation Oncology Journal
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    • v.16 no.4
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    • pp.505-515
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    • 1998
  • Purpose : This study is intended to understand the sensitometric characteristics and the emulsion properties of the commercially available CEA TVS film in comparison with the Kodak X-Omat V film. Materials and Methods : For this purpose, we have formulated an analytic expression of the characteristic curves for x-ray film exposed to mixed radiation of electrons, photons, and visible light. This mathematical expression was developed based on reaction-rate and target-hit theories. Unlike previous expressions. it relates optical density to emulsion properties such as grain size and silver bromide content We have also developed a quantity which characterizes the film response to visible light relative to that to photons and electrons. This quantity could be expressed as a function of grain area. Thus, we have developed mathematical expressions and quantities with which the emulsion properties of the films can be revealed based on the sensitometric characteristics. Demonstrating the use of this analytical study, we exposed CEA and Kodak verification films to the mixed radiation of electrons, photons, and visible light, and interpreted the experimental results accordingly. Results : We have demonstrated that: (1) the saturation density increases as the silver bromide content increases, (2) the time required to reach the threshold dose (to which the film begins to respond) when films are exposed to visible light decreases as the grain size increases, and (3) the CEA film contains more silver bromide. whereas the Kodak film contains larger grains. These findings were supported by the data provided by the manufacturers afterward. Conclusion : This study presented an analytical and experimental basis for understanding the response of X-ray film with respect to the emulsion properties.

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Incidence and Risk Factors of Recurrent Urinary Tract Infections during Antibiotic Prophylaxis in Children with Primary Vesicoureteral Reflux (일차성 방광요관역류 소아에서 항생제 예방요법 중에 발생한 재발성 요로감염의 빈도와 위험인자)

  • Cho Su-Jin;Kim, Hyun-Jin;Lee Jeong-Won;Lee Seung-Joo
    • Childhood Kidney Diseases
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    • v.9 no.1
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    • pp.46-55
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    • 2005
  • Purpose : Recurrent urinary tract Infection(UTI) in primary vesicoureteral reflux(VUR) may lead to serious renal scarring, a major cause of childhood hypertension and end-stage renal disease. To prevent recurrent UTI, low-dose long--term antibiotic prophylaxis has been recommended. However, recurrent UTI still develops during antibiotic prophylaxis, the efficacy of which is now being disputed. The emergence of resistant bacteria has also raised concerns. To evaluate the effect of antibiotic prophylaxis, we investigated recurrent UTI during prophylactic antibiotic use in children with primary VUR Materials : The incidence and risk factors of recurrent UTI were retrospectively evaluated in ninety-one children with primary VUR on trimethoprim- sulfamethoxazole(TMP/SMX) prophylafis during the year following their index febri]e UTI. Results : Recurrent UTI occurred in 31.9%(29/91) children and comprised 0.32 episodes/patient year. Febrile UTI was 0.26 episode/patient year and afebrile UTI was 0.07 episodes/patient year. The recurrent rate of UTI in male patients with phimosis was 37.2%(19/51), which was significantly higher than in males without phimosis 0%(0/5)(P=0.025). In the logistic regression analysis for recurrent UTI, renal scar was the significant risk factor for recurrent UTI [RR 3.8(95% CI 1.0-14.1) P=0.04]. For other well-known risk factors such as sex, age, degree of VUR, APN, and voiding dysfunction, the differences were not significant. Conclusion : TMP/SMX prophylaxis did not prevent recurrent UTI in children with primary VUR. Phimosis and renal scars were the risk factors for recurrent UTI but the grade of primary VUR was not. In VUR without phlmosis and renal scar, a randomized controlled study without antibiotic prophylaxis is required. (J Korean Soc Pediatr Nephrol 2005;9:46-55)

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Presence of Leukemia-maintaining Cells in Differentiation-resistant Fraction of K562 Chronic Myelogenous Leukemia (만성 골수성 백혈병 K562세포의 분화 내성 분획에서 백혈병 유지 세포의 동정)

  • Lee, Hong-Rae;Kim, Mi-Ju;Ha, Gahee;Kim, So-Jung;Kim, Sun-Hee;Kang, Chi-Dug
    • Journal of Life Science
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    • v.23 no.2
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    • pp.197-206
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    • 2013
  • The present study investigated whether leukemia-maintaining cells reside in a differentiation-resistant fraction using a megakaryocytic differentiation model of K562 cells. Treatment with phorbol-12-myristate-13-acetate (PMA) significantly inhibited the colony-forming efficiency of the K562 cells. At a PMA concentration of 1 nM or higher, colony was not formed, but approximately 40% of K562 cells still survived in soft agar. Approximately 70% of colony-forming cells that were isolated following the removal of PMA after exposure to the agent were differentiated after treatment with 10 nM PMA for 3 days. The differentiation rate of the colony-forming cells was gradually increased and reached about 90% 6 weeks after colony isolation, which was comparable to the level of a PMA-treated K562 control. Meanwhile, imatinib-resistant variants from the K562 cells, including K562/R1, K562/R2, and K562/R3 cells, did not show any colony-forming activity, and most imatinib-resistant variants were CD44 positive. After 4 months of culture in drug-free medium, the surface level of CD44 was decreased in comparison with primary imatinib-resistant variants, and a few colonies were formed from K562/R3 cells. In these cells, Bcr-Abl, which was lost in the imatinib-resistant variants, was re-expressed, and the original phenotypes of the K562 cells were partially recovered. These results suggest that leukemia-maintaining cells might reside in a differentiation-resistant population. Differentiation therapy to eliminate leukemia-maintaining cells could be a successful treatment for leukemia if the leukemia-maintaining cells were exposed to a differentiation inducer for a long time and at a high dose.

The Development of Filter for Environmental Improvement in Land Based Seawater Fish Farm III. Purification Efficiency of Rearing Seawater by Screen Filter and Ultraviolet (필터의 개발을 통한 해수 육상수조식 양식장의 환경개선에 관한 연구 III. 스크린필터 및 자외선 등의 운행에 따른 사육수의 정화효과)

  • KANG Ju-Chan;PARK Soo-Il;KIM Seoung-Gun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.4
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    • pp.501-506
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    • 1999
  • This study was conducted to evaluate the purification efficiency in rearing water of the land based fish farm by screen filter and ultra violet (UV) irradiation. Purification efficiency for rearing seawater has been examined with screen filter of 60 $\mu$m pore size and UV irradiation at dose of 0.5 $mWS/cm^2$ for 5 months. Purification efficiency by changing of temperature, salinity, pH, DO, total bacteria and Vibrio species in rearing seawater by filtering and UV irradiation were not significant during 5 months, However, the removing rate of suspended solid and turbidity of rearing seawater were $43.8\~45.6\%$ (average, $44,7\%$) and $29.2\~33.2\%$ (average, $31,3\%$) by filtering, respectively. Also, Purification efficiency for the $NO_3^{-}-N,\;NO_2^{-}-N,\;NH_4^{+}-N$ and $PO_4^{3-}-P$ were $21.3\~21.9\%$ (average, $21.6\%$), $24.1\~25.2\%$ (average, $24.7\%$), $17.6\~17.8\%$ (average, $17.7\%$) and $19.0\~20.4\%$ (average, $19.7\%$) respectively by the system used on this study.

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Effect of Pimpinella brachycarpa Extract on Lipid Metabolism in Rats Fed High Cholesterol Diet (참나물이 고콜레스테롤식이를 섭취한 흰쥐의 지질대사에 미치는 영향)

  • Lee, Jae-Joon;Choo, Myung-Hee;Lee, Myung-Yul
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.9
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    • pp.1151-1158
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    • 2006
  • This study was performed to investigate the effect of ethanol extract of Pimpinella brachycarpa (PB) on serum and liver lipid metabolism in rats. Male Sprague Dawley rats were administered 1% cholesterol and 0.25% sodium cholate to induce hypercholesterolemia. PB ethanol extract (200 mg/kg/day or 400 mg/kg/day) was also administered orally to rats with high cholesterol diet for 6 weeks. We divided 40 rats into five groups; normal diet group (NC), high cholesterol diet group (HC), normal diet and PB ethanol extract (200 mg/kg) administered group (NC-PB), high cholesterol diet and PB ethanol extract (200 mg/kg) administered group (HC-PBL), and high cholesterol diet and PB ethanol extract (400 mg/kg) administered group (HC-PBH). The growth rate and liver weight of the high cholesterol diet group was higher than those of the normal diet group, whereas those of the groups administered PB ethanol extract were gradually decreased. There was a signigicant increase in the activities of serum alanine aminotransferase (ALT), asparate aminotransferase (AST) and alkaline phosphatase (ALP) in the high cholesterol diet group. The administration of PB ethanol extract decreased serum ALT, AST and ALP activities in a dose-dependent manners. The high cholesterol diet group showed increased serum triglyceride, total cholesterol, free cholesterol and LDL-cholesterol levels, and decreased atherogenic index, HDL-cholesterol and phospholipid levels as compared with the normal diet group. PB ethanol extract administrated groups showed increased HDL-C/T-C, HDL-cholesterol and phospholipid levels, and decreased serum triglyceride, total cholesterol, free cholesterol, and LDL-cholesterol levels as compared with the high cholesterol diet group. There were no differences in the concentrations of serum triglyceride, phopholipid, LDL-cholesterol, HDL-cholesterol and free cholesterol between normal diet groups. The hepatic concentrations of total cholesterol and triglyceride were also lower in PB ethanol extract administrated groups than in the high cholesterol diet group. These results suggest that ethanol extract of PB exerts hypocholesterolemic effect by reducing serum and liver cholesterol contents.