• The Korean Journal of Physiology and Pharmacology
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• 제9권5호
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• pp.291-298
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• 2005

To characterize cytosolic $Ca^{2+}$ fluctuations under metabolic inhibition, rat ventricular myocytes were exposed to $200{\mu}M$ 2,4-dinitrophenol (DNP), and mitochondrial $Ca^{2+}$, mitochondrial membrane potential (${\Delta}{\Psi}m$), and cytosolic $Ca^{2+}$ were measured, using Rhod-2 AM, TMRE, and Fluo-4 AM fluorescent dyes, respectively, by Laser Scanning Confocal Microscopy (LSCM). Furthermore, the role of sarcolemmal $Na^+$/$Ca^{2+}$ exchange (NCX) in cytosolic $Ca^{2+}$ efflux was studied in KB-R7943 and $Na^+$-free normal Tyrode's solution (143 mM LiCl ). When DNP was applied to cells loaded with Fluo-4 AM, Fluo-4 AM fluorescence intensity initially increased by $70{\pm}10$% within $70{\pm}10$ s, and later by $400{\pm}200$% at $850{\pm}45$ s. Fluorescence intensity of both Rhod-2 AM and TMRE were initially decreased by DNP, coincident with the initial increase of Fluo-4 AM fluorescence intensity. When sarcoplasmic reticulum (SR) $Ca^{2+}$ was depleted by $1{\mu}M thapsigargin plus $10{\mu}M ryanodine, the initial increase of Fluo-4 AM fluorescence intensity was unaffected, however, the subsequent progressive increase was abolished. KB-R7943 delayed both the first and the second phases of cytosolic $Ca^{2+}$ overload, while $Na^+$-free solution accelerated the second. The above results suggest that: 1) the initial rise in cytosolic $Ca^{2+}$ under DNP results from mitochondrial depolarization; 2) the secondary increase is caused by progressive $Ca^{2+}$ release from SR; 3) NCX plays an important role in transient cytosolic $Ca^{2+}$ shifts under metabolic inhibition with DNP.

• 대한두경부종양학회지
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• 제17권2호
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• pp.174-178
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• 2001

Background and Objective: Percutaneous ethanol injection therapy has been used in the treatment of the benign thyroid diseases. Although the reported side-effects of the therapy was mild and transient, some side-effects including local or radiating pain are troublesome to the patients. Radioactive iodine-131($Ra-^{131}I$) also has been effectively and safely used for management of the benign thyroid diseases. So we developed the percutaneous intranodular injection therapy of $Ra-^{131}I$ as an alternative of percutaneous ethanol injection therapy. Materials and Methods: From December 1998 to October 1999, we treated 29 outpatients (25 women and 4 men, mean age: $47{\pm}12$ years). Inclusion criteria were follows; age >30 years, cytologically benign, with normal thyroid function, cold nodule on thyroid scintigram, solid or mixed natured nodules in sonographical evaluation. Nodular volume was estimated by sonography according to the ellipsoid formula. $Ra-^{131}I$(0.1mCi/ml) was administered in a single dose injection. Follow-up studies every 3 months consisted of full history, thyroid function test, and sonography. We determined the therapeutic response is effective if the volume reduction of the nodule occurred above 30%. Results: After at least 3 months follow-up, 11 patients showed effective response, 12 patients showed minimal or unchanged response and 6 patients showed progression. Although side-effects such as injection pain, febrile reaction, and hormonal changes were absent, an infectious complication in injection site was developed from 1 case. Conclusion: Although we need a more prolonged follow-up to evaluate the delayed sequelae, we can suggest that percutaneous intranodular injection therapy of $Ra-^{131}I$ may be an attractive non-surgical treatment in selected cases of benign thyroid nodules.

• Journal of Pharmaceutical Investigation
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• 제25권3호spc1호
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• pp.7-20
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• 1995

Taurine, a ${\beta}-amino$ acid, plays an important role as a neuromodulator and is necessary for the normal development of the brain. Since de novo synthesis of taurine in the brain is minimal and in vivo studies suggest that taurine dose not cross the blood-brain barrier, we examined whether the choroid plexus, the blood-cerebrospinal fluid (CSF) barrier, plays a role in taurine transport in the central nervous system. The uptake of $[^3H]-taurine$ into ATP depleted choroid plexus from rabbit was substantially greater in the presence of an inwardly directed $Na^+$ gradient taurine accumulation was negligible. A transient in side-negative potential gradient enhanced the $Na^+-driven$ uptake of taurine into the tissue slices, suggesting that the transport process is electrogenic, $Na^+-driven$ taurine uptake was saturable with an estimated $V_{max}$ of $111\;{\pm}\;20.2\;nmole/g/15\;min$ and a $K_M\;of\;99.8{\pm}29.9\;{\mu}M$. The estimated coupling ratio of $Na^+$ and taurine was $1.80\;{\pm}\;0.122.$ $Na^+-dependent$ taurine uptake was significantly inhibited by ${\beta}-amino$ acids, but not by ${\alpha}-amino$ acids, indicating that the transporter is selective for ${\beta}-amino$ acids. Since it is known that the physiological concentration of taurine in the CSF is lower than that in the plasma, the active transport system we characterized may face the brush border (i.e., CSF facing) side of the choroid plexus and actively transport taurine out of the CSF. Therefore, we examined in vivo elimination of taurine from the CSF in the rat to determine whether elimination kinetics of taurine from the CSF is consistent with the in vitro study. Using a stereotaxic device, cannulaes were placed into the lateral ventricle and the cisterna magna of the rat. Radio-labelled taurine and inulin (a marker of CSF flow) were injected into the lateral ventricle, and the concentrations of the labelled compounds in the CSF were monitored for upto 3 hrs in the cisterna magna. The apparent clearance of taurine from CSF was greater than the estimated CSF flow (p<0.005) indicating that there is a clearance process in addition to the CSF flow. Taurine distribution into the choroid plexus was at least 10 fold higher than that found in other brain areas (e. g., cerebellum, olfactory bulb and cortex). When unlabelled taurine was co-administered with radio-labelled taurine, the apparent clearance of taurine was reduced (p<0.0l), suggesting a saturable disposition of taurine from CSF. Distribution of taurine into the choroid plexus, cerebellum, olfactory bulb and cortex was similarly diminished, indicating that the saturable uptake of taurine into these tissues is responsible for the non-linear disposition. A pharmacokinetic model involving first order elimination and saturable distribution described these data adequately. The Michaelis-Menten rate constant estimated from in vivo elimination study is similar to that obtained in the in vitro uptake experiment. Collectively, our results demonstrate that taurine is transported in the choroid plexus via a $Na^+-dependent,saturable$ and apparently ${\beta}-amino$ acid selective mechanism. This process may be functionally relevant to taurine homeostasis in the brain.

• 대한약리학회지
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• 제27권2호
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• pp.125-133
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• 1991

내피세포가 제거된 토끼의 적출 장간막 동맥에서 토끼의 대동맥 내피세포로 부터 A23187과 acetylcholine은 NO와 유사한 혈관 이완성 물질 (EDRF)을 유리한다. 이에 첨가하여 A23187은 acetylcholine과는 달리 superoxide anion에 의하여 파괴되지 않는 EDRF도 유리시킴을 확인하고 이의 특성에 대하여 연구하였다. 정상적인 생리영양액에서는 A23187과 acetylcholine의 용량-반응 곡선은 내피세포에 의존하지 않는 sodium nitroprusside의 곡선과 유사하였다. 이들은 methylene blue에 의하여 억제되었다. Hypoxanthine (HX)과 xanthine oxidase (XO)를 bath내로 투여시 phenylephrine에 의한 수축이 일과성으로 증가한 후 지속적으로 이완되었다. HX-XO 반응중에는 A23187은 장간막 동맥을 즉각적으로 이완시켰으나 acetylcholine의 이완작용은 소실되었다. A23187에 의하여 야기되는 장간막동맥의 이완은 50 mM $K^+-PSS$로 수축을 야기시켰을 때에는 나타나지 아니하였다. Superoxide dismutase를 전처치하였을 때는 HX-XO 반응중에도 acetylcholine 뿐만아니라 A23187에 의한 장간막 동맥의 수축은 이완되었다. 한편, acetylcholine에 의하여 야기되는 장간막 동맥의 이완은 A23187에 의하여 야기되는 이완에 비하여 phorbol 12-myristate 13-acetate (PMA)에 훨씬 더 민감하게 억제되었다. 내피세포의 기능과는 무관한 sodium nitroprusside에 의하여 야기되는 이완은 PMA에 의하여 영향을 받지 아니하였다. 이상의 결과로 미루어 볼때, A23187과 acetylcholine은 methylene blue에 의하여 억제되는 내피세포 의존성 이완을 야기시키고, 첨가하여 A23187은 어떤 병적 환경 아래서는 superoxide anion과 PMA에 저항성을 지닌 혈관이완성 물질을 유리하는 것으로 사료된다. 앞으로 A23187에 의하여 유리되는 혈관 이완성 물질이 superoxide anion에 의존하여 생성된 것인지에 대하여는 추후의 연구과제이다.

• Nuclear Engineering and Technology
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• 제26권3호
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• pp.440-452
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• 1994

핵연료 다발의 설계는 핵연료 표면에서의 열속이 임계열속에 도달되지 않도록 이루어져야한다. 이를 위해서는 설계된 핵연료 다발에 대한 임계열속이 정화하고 신뢰성 있게 평가되는 것이 매우 중요하다. 그러나 현재 사용되고 있는 임계열속 상관식에 관한 쟁점 대상중의 하나는 원통튜브관에서 실험적으로 얻어진 임계열속 자료가 유효직경 형태의 변수와 적당한 보정인자를 사용하여 핵연료다발 부수로 분석에 사용되고 있다는 것인데, 이러한 방법은 임계열속 예측에 있어서 불확실도 요인으로 작용하고 있다. 유효직경은 유동단면적상의 국부적 유체 특성을 제대로 표현하지 못 할 뿐만 아니라 표면구배효과 등을 고려할 수 없다. 더구나 난류유동은 오목구배면에서 보다는 볼록구배면에서 더욱 두드러진다. 즉, 횡방향 볼록구배면이 오목구배면 보다 유동의 반경방향으로의 난류 형성에 영향이 훨씬 크게 나타나는데, 이는 정화한 핵연료 임계열속 평가에 있어서 볼록구배의 영향이 반드시 고려되어야 함을 암시하는 것이다. 본 논문에서는 횡방향 구배의 유동영향에 대하여 전반적으로 심도있게 고찰하고 임계열속에 대한 영향이 논의 되었으며, 이 영향을 정량화하기 위하여 고려되어야 할 유동 모델과 향후 연구 방향이 제시되었다.

• 대한치과마취과학회지
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• 제14권3호
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• pp.157-165
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• 2014

Background: Incisional site of surgical operation become transient ischemic state and then occur reoxygenation due to vasodilatation by inflammatory reaction, the productive reactive oxygen species (ROS) give rise to many physiologic results. Apoptosis have major role on elimination of inflammatory cell and formation of granulation tissue in normal wound healing process. Remifentanil can prevent the inflammatory response and can suppress inducible nitric oxide synthase expression in a septic mouse model. After cardiopulmonary bypass for coronary artery surgery, remifentanil can also inhibit the release of biomarkers of myocardial damage. Here we investigated whether remifentanil pretreatment has cellular protective effect against hypoxia-reoxygenation in HaCaT human keratinocytes, if so, the role of apoptosis and autophagy on this phenomenon. Methods: The HaCaT human keratinocytes were exposed to various concentrations of remifentanil (0.01, 0.05, 0.1, 0.5 and 1 ng/ml) for 2 h before hypoxia (RPC/HR group). These cells were cultured under 1% oxygen tension for 24h at $37^{\circ}C$. After hypoxia, to simulate reoxygenation and recovery, the cells were reoxygenated for 12 h at $37^{\circ}C$. 3-MA/RPC/HR group was treated 3-methyladenine (3-MA), autophagy inhibitor for 1h before remifentanil treatment. Cell viability was measured using a quantitative colorimetric assay with thiazolyl blue tetrazoliumbromide (MTT, amresco), showing the mitochondrial activity of living cells. To investigate whether the occurrence of autophagy and apoptosis, we used fluorescence microscopy and Western blot analysis. Results: The viability against hypoxia-reoxygenation injury in remifentanil preconditioning keratinocytes were increased, and these cells were showed stimulated expression of autophagy 3-MA suppressed the induction of autophagy effectively and the protective effects on apoptosis. Atg5, Beclin-1, LC3-II and p62 were elevated in RPC/HR group. But they were decreased when autophagy was suppressed by 3-MA. Conclusions: Remifentanil preconditioning showed the protective effect in human keratinocytes, and we concluded that autophagy may take the major role in the recovery of wound from hypoxia-reoxygenation injury. We suggest that further research is needed about the cell protective effects of autophagy.

• 대한기계학회논문집B
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• 제39권7호
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• pp.567-578
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• 2015

Leidenfrost 온도 이상으로 가열된 벽면과 충돌하는 액적의 속도가 열전달 특성에 미치는 영향에 관한 실험 연구를 수행하였다. 동기화된 초고속 가시화 카메라와 적외선 카메라를 이용하여 벽면과 충돌하는 액적의 충돌 특성과 충돌면의 온도 분포를 측정하였다. 획득한 표면온도 분포를 충돌면의 경계 조건으로 이용하여 가열 벽면의 3차원 비정상 열전도 수치해석을 통해 표면 열유속 분포를 얻었다. 수직방향 충돌속도가 증가할수록 최대 액막 직경이 증가하고 가열 벽면과 액막 사이에 존재하는 증기막의 두께가 감소하여 열전달 효율이 증가하였다. 액적은 웨버수가 30보다 작은 경우 되튐현상이 발생하였으며, 큰 경우 작은 액적들로 분쇄되어졌다. 충돌속도에 의한 열전달량의 증가 경향이 되튐영역에서 분쇄영역에서 가면서 약화되었으며, 이는 분쇄현상에 의해 유효 열전달 면적의 확대 효과가 저감되었기 때문으로 해석된다.

• Nuclear Engineering and Technology
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• 제19권1호
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• pp.22-33
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• 1987

원자력 발전소에 있어서 정상가동 상태나 이상동작시에 핵연료 피복관의 건전성 확보와 연관하여 피복재의 항복거동은 중요한 문제이다. 급격한 출력상승 상황에서 이산화 우라늄 소결체와 피복관 사이의 노내 조사거동의 차이는 소결체와 피복관 사이에 Contact Pressure를 야기 시킨다. 만일 이 Contact Pressure가 Zircaloy 피복관의 Yield Pressure에 도달하면 피복관에는 영구변형이 일어난다. 이 변형은 원자로의 출력이 정상상태로 회복되더라도 존재하므로 소결체와 피복관 사이의 Gap을 증대시킨다. 이러한 상황을 묘사하기 위해 본 논문에서는 구리 Mandrel과 Zircaloy사이의 열팽창 차이를 이용하는 Mandrel 팽창 실험을 실행했다. 실험 결과 측정된 Zircaloy 피복관의 외경 팽창치와 본 논문에서 유도된 수학적 관계식들을 이용하여 온도에 따른 Zircaloy 피복관의 내부항복압력과 항복응력, 피복재의 항복에 따른 핵연료 소결체와 피복관 사이의 Gap 증대를 구하고, 항복 거동에 따른 온도의 영향을 보기 위해 항복과정의 활성화 에너지를 구했다. 본 실험과 분석에서 얻어진 이들 결과들은 다른 실험 결과들과 상당히 일치하였으며, 이것으로 볼 때 본 논문에서 유도된 관계식들과 Mandrel 팽창 실험이 Zircaloy 피복관의 항복거동과 Gap Expansion 측정에 신뢰성이 있음을 알 수 있었다.

• Childhood Kidney Diseases
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• 제2권2호
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• pp.133-137
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• 1998

목 적 : 1987년 정주용 면역글로불린(Intravenous immunoglobulin: IVIG)에 의한 급성신부전의 첫 증례가 보고된 이후 성인에서는 고용량의 IVIG와 관련된 신손상의 보고들이 다수 있었다. 이에 저자들은 고용량 IVIG의 사용이 보편화되어 있는 가와사끼병과 특발성 혈소판 감소성 자반증 환아에서 IVIG의 신독성 여부를 관찰하고자 하였다. 방 법 : 1996년 1월에서 8월까지 이대 부속 목동 병원에 입원하여 가와사끼병(23례)과 특발성 혈소판 감소성 자반증(7례)으로 고용량의 정주용 면역글로불린(2 g/kg)을 투여받은 환아를 대상으로 하였다. IVIG투여후 1일, 3일에 요량, BUN, 혈청 creatinine, Ccr, FENa, TRP, 24 시간뇨 ${\beta}_2$-microglobulin/cr 비 및 microalbumin/cr 비의 변화를 관찰하였다. 통계는 repeated measurement ANOVA test와 t-test를 사용하여 검정하였다. 결 과 : 고용량의 IVIG 투여후에 요량, BUN, 혈청 creatinine, Ccr, TRP, 24 시간뇨 ${\beta}_2$-microglobulin/cr 비 및 microalbumin/cr비의 유의한 변화는 없었다. IVIG투여후 1일에 일시적으로 증가한 FENa만이 유의한 변화였다. 결 론 : 소아에서 흔히 사용되는 고용량 IVIG는 정상 신기능 상태에서는 유의한 신손상을 일으키지 않았다.

• 한국임상수의학회지
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• 제22권4호
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• pp.450-452
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• 2005

A 3-year-old, 43kg, pregnant Great Pyrenese was examined for clinical signs of acute weakness and anorexia for 4 days. The dog was in lateral recumbency at referral. The rectal temperature was within reference range, and the respiratory and heart rates were 36 breaths/min and 58 beats/min, respectively. The abdomen was distended, and several puppies were palpated. The mean fetal head diameter was 2.8cm in the ultrasonographic examination. The initial complete blood count and serum biochemical examinations revealed mild dehydration, mud hyperglycemia, hypochloremia, hyperkalemia, hyponatremia, and low sodium-potassium ratio. Serum BUN and total cholesterol values were slightly high. Hypoadrenocortical crisis was suspected on the basis of signs of acute collapse, hyponatremia and hyperkalemia. Adrenal gland function was evaluated by an ACTH stimulation test. The baseline cortisol concentration was $18.6{\mu}g/dl$ and the concentration at 1 hour after administration of tetracosactrin (ACTH, Synacthen) was $8{\mu}g/dl$. The dog was treated for the correction of assumed hypoadrenocortical crisis and substantial hyperkalemia. In addition to rapid infusion with saline solution, other medications administered intravenously included sodium bicarbonate and cimetidine hydrochloride. The dog was monitored with repeated serum electrolyte examination. After clinical stabilization, cesarean section was performed. All of 13 puppies were delivered, and the dog recovered from anesthesia without complications. The values of postpartum blood tests returned to normal or within reference range. The dog remained healthily.