• 대한핵의학회지
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• 제21권2호
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• pp.175-182
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• 1987

For measurement of ventricular performance, ejection fraction (EF) has gained wide acceptance. But EF is influenced not only by changes in muscle function but also by changes in cardiac loading conditions. In case of valvular heart disease which is variable in loading conditions, EF cannot be reliable as an index of myocardial contractility. The end systolic pressure (ESP)-end systolic volume (ESV) relation, howver, is known to represent myocardial contractility, independent of changes in loading conditions. Similar results can be obtained by using peak-systolic pressure (PSP) instead of ESP. To evaluate the utility of the peak systolic pressure-end systolic volume index (PSP-ESVI) relation as an index of myocardial function, we measured $PSP&ESVI$ in 19 partents with coronary artery disease before $(PSP_1\;&\;ESVI_1)$ and after $(PSP_2\;&\;ESVI_2)$ sublingual administration of nitroglycerin. PSP was measured with standard mercury sphygmomanometer during gated blood pool scintigraphic study. ESVI was measured by count derived method after attenuation correction. $PSP_2\;&\;ESVI_2$ measurement was started when the fall of PSP was greater than 5 mmHg after 7-14 minutes post-administration of nitroglycerin. Mean values $({\pm}S.D.)$ of $PSP_1\;&\;ESVI_1$ was $124.9({\pm}20.7)mmHg\;&\;59.4({\pm}39.9)ml/M^2$. Mean values $({\pm}S.D)$ of $PSP_2\;&\;ESVI_2$, was $113.2({\pm}19.9)mmHg\;&\;37.5({\pm}26.1)ml/M^2$. There was a significant difference between mean values of $PSP_1\;&\;PSP_2$, (p<0.01), and mean values of $ESVI_1\;&\;ESVI_2$, (p<0.01). $PSP_1-PSP_2/ESV_1-ESVI_2,\;PSP_1/ESVI_1$ and EF were in the range of 0.14-5.19 mmHg/ml/$M^2$, 0.67-7.68 mmHg/ml/$M^2$ and 10.8%-74.5% respectively. $PSP_1-PSP_2/ESVI_1-ESVI_2$, and EF showed exponential correlation (r=0.85, P<0.01). The correlation coefficient between $PSP_1/ESVI_1$ and EF was 0.73(p<0.01). With the above results, we suggest that $PSP_1-PSP_2/ESVI_1-ESVI_2$, and $PSP_1/ESVI_1$, can be used as an index of myocardial function.

• 대한핵의학회지
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• 제35권5호
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• pp.313-323
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• 2001

목적: 저선량 방사선에 의해 그 이후의 고선량 방사선에 저항이 생기는 유익한 반응을 보인다는 방사선적응반응이라는 현상이 알려져 있지만, 저선량 방사선이 어떤 기작에 의해 이런 반응을 일으키는지에 대해서는 아직 알려지지 않고 있다. 본 연구에서는 정상 인체세포주에서 저선량 $^{99m}Tc$에 의해 방사선적응반응이 유도되는지를 확인하고, 이 때 활성화되는 유전자를 찾아보고자 하였다. 대상 및 방법: 인체 정상 림프구 세포주인 NC-37 세포주 $2{\times}10^6mL$개의 세포에 $^{99m}Tc$을 148 MBq/mL로부터 148 Bq/mL의 농도가 되도록 10배씩 희석하여 첨가하고 44시간동안 배양하였다. 결과: 각각의 군에 대해 이상 염색체를 계수하여 148 KBq/mL의 $^{99m}Tc$을 첨가한 군에서 방사선적응반응이 가장 현저하게 유도되었음을 확인하였다. 이 세포군에서 mRNA를 추출하고 여기에서 cDNA를 만든 후 gene discovery array (GDA) 여과기를 이용하여 대조군에 비해 발현이 증가된 casein kinase II beta chain, immunoglobulin, HLA-B 그리고 아직 알려지지 않은 2개의 유전자 등 6개의 유전자를 찾아내었다. Representational difference analysis (RDA)법을 통해서는 대조군에 비해 발현이 증가된 유전자 클론을 20개 찾아내었다. 결론: 인체세포주 NC-37에서 저선량의 $^{99m}Tc$에 의해 방사선적응반응이 유도된다는 사실을 밝혔으며, 이때 다수의 유전자가 발현된다는 사실을 알 수 있었다.

• Nuclear Medicine and Molecular Imaging
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• 제41권6호
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• pp.546-552
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• 2007

목적: 유방암 환자에게 불필요한 액와림프절 전절제술을 예방하기 위해서는 감시림프절을 절제하여 전이 여부를 평가하는 것이 중요하다. 감시림프절 매핑을 위한 방사성교질중 antimony trisulfide colloid (ASC), tin colloid (TC), human serum albumin (HSA) 이상의 3가지 교질에 $^{99m}Tc$을 표지하여 각각에서 림포신티그라피, 감시림프절 매핑의 성적을 비교하였다. 대상 및 방법: 2001년 10월부터 2006년 12월까지 임상적으로 액와림프절 전이가 없는 조기 유방암 환자 총 397명에게 시행한 림포신티그라피와 수술 중 감시림프절 절제 동결절편 검사, 및 수술 후 병리 소견을 후향적으로 평가하였다. 림포신티그라피 영상 소견을 분석하고, 감시림프절의 발견율(identification rate)과 위음성율(false negative rate), 그리고 음성예측도(negative predictive value)를 구하여 각 군의 자료에 대해 Fisher 직접확률법으로 비교하였다. 결과: 202명에게는 $^{99m}Tc$ ASC를, 120명에게는 $^{99m}Tc$-TC를, 75명에게는 $^{99m}Tc$-HSA를 사용하였으며 평균 연령, 병기, 원발 종양의 크기 등에서는 각 군별 환자들 사이에 유의한 차이가 없었다. ASE는 59명에게는 유륜부 피내 혹은 피하주사법을 사용했으며 136명에게는 종양주위 주사를, 그리고 7명의 환자에게는 두 가지를 병용하였다. TC와 HSA를 사용한 환자들에게는 모두 피내 혹은 피하주사하였다. 액와림프절 전이는 ASE사용 군에서 33.2%, TC 사용군에서 31.7%, HSA 사용 군에서 22.7%였으며 통계적으로 유의한 차이는 없었다. 감시 림프절 발견율(IR) 과 위음성율(FNR) 그리고 음성예측도(NPV) 는 사용한 교질 ASC/TC/HSA 각각에 대해 99.0%, 21.5%, 90.5% / 96.7%, 20.5%, 90.7% / 94.7%, 17.7%, 94.7%로 사용한 교질의 종류에 따라 통계적으로 유의한 차이가 없었다. 감시림프절 매핑 성적은 방사성교질의 주사방법에 따라서 유의한 차이를 보이지 않았다. 림포신티그라피의 영상에서 감시림프절이 명확히 구분된 경우는 ASC에서 79.6%, TC 에서 92.5%, HSA에서 88.6%였다. 림프관이 관찰된 비율은 ASC에서 43.6%, TC에서 0.8%, HSA 에서 96.8%이었다. 림포신티그라피에서 관찰된 감시림프절의 개수는 HSA가 가장 많았지만 통계적으로 유의한 차이는 없었다. 결론: ASC, TC 및 HSA등의 방사성교질을 이용한 감시림프절 매핑 성적은 서로 유의한 차이를 보이지 않았다.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1997년도 7월 학술대회지
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• pp.142-143
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• 1997

The purpose of this paper is to assess the psychological status of the phoneme, syllable, and various postulated subsyllabic units in Korean by applying the Sound Similarity Judgment (SSJ) task, to compare the results with those in English, and to discuss the advantage and disadvantage of the SSJ task as a tool for linguistic research. In Experiment 1, 30 subjects listened to pairs of 56 eve words which were systematically varied from 'totally different' (e.g., pan-met) to 'identical' (e.g., pan-pan). Subjects were then asked to rate sound similarity of each pair on a 10-point scale. Not very surprisingly, there was a strong correlation between the number of phonemic segments matched and the similarity score provided by the subjects. This result was in accord with the previous results from English (e.g., Vitz & Winkler, 1973; Derwing & Nearey, 1986) and supported the assumption that the phoneme is the basic phonological unit in Korean and English. However, there were sharply contrasting results between the two languages. When the pairs shared two phonemes (e.g., pan-pat; pan-pen; pan-man), the pairs sharing the fIrst two phonemes were judged significantly more similar than the other two types of pairs. Quite to the contrary, in the comparable English experiments, the pairs sharing the last two phonemes were judged significantly more similar than the other two types of pairs. Experiment 2 was designed to conflrm the results of Experiment 1 by controlling the 'degree' of similarity between phonemes. For example, the pair pan-pam can be judged more similar than the pair pan-nan, although both pairs share the same number of phonemes. This could be interpreted either as confirming the result of Experiment 1 or as the fact that /n/ is more similar to /m/ than /p/ is to /n/ in terms of shared number of distinctive features. The results of Experiment 2 supported the former interpretation. Thus, the results of both experiments clearly showed that, although the 'number' of matched phonemes is the important predictor in judging sound similarity of monosyllabic pairs of both languages, the 'position' of the matched phonemes exerts a different influence in judging sound similarity in the two languages. This contrasting set of results may provide interesting implications for the internal structure of the syllable in the two languages.

• 대한핵의학회지
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• 제37권5호
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• pp.325-330
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• 2003

Purpose: We describe a 54-year-old woman with systemic lupus erythematosus (SLE) who suddenly presented with chorea and had positive antiphospholipid antibodies. F-18 FDG PET showed abnormally increased glucose metabolism in bilateral putamen and primary motor cotex. Tc-99m ECD SPECT also showed abnormally increased regional cerebral blood flow in bilateral putamen. She was treated with corticosteroid and aspirin after which the symptoms improved. Four months later, follow up F-18 FDG PET showed improvement with resolution of hypermetabolism in bilateral putamen. This case suggests that striatal hypermetabolism is associated with chorea in SLE.

• Journal of Pharmaceutical Investigation
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• 제41권1호
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• pp.51-57
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• 2011

The objective of this study was to enhance the utilitization of Ibuprofen (IBU) by introducing the fast-disintegrating tablet (FDT) form. Presently, IBU is being widely used as a tablet or syrup form. But in contrast to these two formulations, IBU as FDT is not only convenient but also increases the control over the time release of the drug, noted by using Alginate beads. This study was carried out with Sodium Alginate and IBU at the ratios of 1:0, 1:0.5, 1:1, and 1:2 in order to produce a series of beads with different ratios. During the drying process of the beads, talc was added in beads to compare the effects with and without the talc. The final product was scanned with SEM imaging to determine the difference in the surface of the beads. The parameters assessed were the diameter, content assay, dissolution test and effectiveness of time-release. Direct compression method was used to prepare FDT containing IBU bead. The properties of FDT, such as hardness, disintegration time, were investigated. The dissolution profiles of FDT were tested using KP dissolution apparatus 1 (basket method). The results suggest addition of talc and drying the beads made the surface smooth and less vulnerable to clutter into chunks. The size of beads was less than 300 ${\mu}m$ which did not create a sandy feeling in the mouth. Thus, the beads formulation model made the sustained release of the drug possible, the hardness of FDT (1.25~1.50 $Kg/cm^2$) was acceptable and all the values of dissolving period were less than 30 seconds. The dissolution profile of FDT was same as that of IBU bead. The efficient dissolution profile and low price of IBU bead containing Sodium Alginate, the FDT formulation prepared from IBU bead can save the expenses and can improve the convenience of application of this drug.

• Journal of Microbiology and Biotechnology
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• 제21권8호
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• pp.874-883
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• 2011

Many studies have shown that the steamed root of Rehmannia glutinosa (SRG), which is widely used in the treatment of various neurodegenerative diseases in the context of Korean traditional medicine, is effective for improving cognitive and memory impairments. The purpose of this study was to examine whether SRG extracts improved memory defects caused by administering scopolamine (SCO) into the brains of rats. The effects of SRG on the acetylcholinergic system and proinflammatory cytokines in the hippocampus were also investigated. Male rats were administered daily doses of SRG (50, 100, and 200 mg/kg, i.p.) for 14 days, 1 h before scopolamine injection (2 mg/kg, i.p.). After inducing cognitive impairment via scopolamine administration, we conducted a passive avoidance test (PAT) and the Morris water maze (MWM) test as behavioral assessments. Changes in cholinergic system reactivity were also examined by measuring the immunoreactive neurons of choline acetyltransferase (ChAT) and the reactivity of acetylcholinesterase (AchE) in the hippocampus. Daily administration of SRG improved memory impairment according to the PAT, and reduced the escape latency for finding the platform in the MWM. The administration of SRG consistently significantly alleviated memory-associated decreases in cholinergic immunoreactivity and decreased interleukin-$1{\beta}$ (IL-$1{\beta}$) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) mRNA expression in the hippocampus. The results demonstrated that SRG had a significant neuroprotective effect against the neuronal impairment and memory dysfunction caused by scopolamine in rats. These results suggest that SRG may be useful for improving cognitive functioning by stimulating cholinergic enzyme activities and alleviating inflammatory responses.

• 천문학회지
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• 제44권6호
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• pp.217-234
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• 2011

We present two large cosmological N-body simulations, called Horizon Run 2 (HR2) and Horizon Run 3 (HR3), made using $6000^3$ = 216 billions and $7210^3$ = 374 billion particles, spanning a volume of $(7.200\;h^{-1}Gpc)^3$ and $(10.815\;h^{-1}Gpc)^3$, respectively. These simulations improve on our previous Horizon Run 1 (HR1) up to a factor of 4.4 in volume, and range from 2600 to over 8800 times the volume of the Millennium Run. In addition, they achieve a considerably finer mass resolution, down to $1.25{\times}10^{11}h^{-1}M_{\odot}$, allowing to resolve galaxy-size halos with mean particle separations of $1.2h^{-1}$Mpc and $1.5h^{-1}$Mpc, respectively. We have measured the power spectrum, correlation function, mass function and basic halo properties with percent level accuracy, and verified that they correctly reproduce the CDM theoretical expectations, in excellent agreement with linear perturbation theory. Our unprecedentedly large-volume N-body simulations can be used for a variety of studies in cosmology and astrophysics, ranging from large-scale structure topology, baryon acoustic oscillations, dark energy and the characterization of the expansion history of the Universe, till galaxy formation science - in connection with the new SDSS-III. To this end, we made a total of 35 all-sky mock surveys along the past light cone out to z = 0.7 (8 from the HR2 and 27 from the HR3), to simulate the BOSS geometry. The simulations and mock surveys are already publicly available at http://astro.kias.re.kr/Horizon-Run23/.

• Molecules and Cells
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• 제24권1호
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• pp.69-75
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• 2007

Alzheimer's disease is a neurodegenerative disorder associated with progressive loss of cognitive function and memory. Amyloid beta peptide ($A{\beta}$) is the major component of senile plaques and is known to exert its cytotoxic effect mainly by producing $H_2O_2$. Vascular endothelial growth factor (VEGF) is elevated in the cerebrospinal fluid (CSF) and brain of AD patients, and $H_2O_2$ is one of the factors that induce VEGF. Therefore, we tested whether $A{\beta}$ might be responsible for the increased VEGF synthesis. We found that $A{\beta}$ induced the production of $H_2O_2$ in vitro. Comparison of the amount of $H_2O_2$ required to induce VEGF synthesis in HN33 cells and the amount of $H_2O_2$ produced by $10{\mu}M\;A{\beta}_{1-42}$ in vitro suggested that a toxic concentration of $A{\beta}$ might induce VEGF synthesis in these cells. However, toxic concentrations of $A{\beta}$ failed to induce VEGF synthesis in several cell systems. They also had no effect on antioxidant enzymes such as glutathione peroxidase, catalase, and peroxiredoxin in HN33 cells. $Cu^{2+}$, $Zn^{2+}$ and $Fe^{3+}$ are known to accumulate in the brains of AD patients and promote aggregation of $A{\beta}$, and $Cu^{2+}$ by itself induces synthesis of VEGF. However, there was no synergistic effect between $Cu^{2+}$ and $A{\beta}_{1-42}$ in the induction of VEGF synthesis and $Zn^{2+}$ and $Fe^{3+}$ also had no effect on the synthesis of VEGF, alone or in combination with $A{\beta}$.

• Archives of Pharmacal Research
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• 제28권9호
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• pp.1079-1085
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• 2005

The purpose of this study was to investigate the safety of chitosan oligosaccharide and the effects of chitosan oligosaccharide on mercury induced genotoxicity in mice using the micronuclei and chromosome aberration. The micronuclei test was performed by microscopic examination $(\times1,000,\;stained\;using\;a\;May-Grunwald\;solution)$ after administering 0.01, 0.1, and $1\%(10\;mg/mL)$ chitosan oligosaccharide for 7, 60, and 180 days ad libitum in mice. Total micronuclei of 1,000 polychromatic erythrocytes were recorded for each group. There was no difference between the untreated and experimental groups. The intake periods and concentrations of chitosan oligosaccharide did not affect the occurrence of micronuclei in bone marrow cells (P>0.05). The chromosomal aberration test was performed by microscopic examination $({\times}1,000,\;stained\;using\;a\;4\%\;Giemsa\;solution)$ after administering the same concentration of chitosan oligosaccharide to mice, in $F_1,\;F_2,\;F_3$ generations and parents. The frequency of chromosomal aberrations was defined as [Ydr=(D+R)/total number of counted lymphocytes]. Similar to the micronuclei test, there was no difference between the untreated and treated groups. These results showed that the intake periods and concentrations of chitosan oligosaccharide did not affect chromosomal aberrations in bone marrow cells (P>0.05). To investigate the effect of chitosan oligosaccharide on mercury-induced chromosome aberration, mice in each condition were supplied with $^{203}HgCl_2$ and chitosan oligosaccharide ad libitum. Chitosan oligosaccharide significantly inhibited $^{203}HgCl_2-induced$ chromosome aberration in mice. Based on the results of this study, it may be concluded that the chitosan oligosaccharide is a nontoxic material that could be used as a suppressor of heavy metal-induced genotoxicity.