• Korean Journal of Radiology
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• 제22권11호
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• pp.1749-1763
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• 2021

Coronary computed tomography angiography (CCTA) is routinely used for anatomical assessment of coronary artery disease (CAD). However, invasive measurement of fractional flow reserve (FFR) is the current gold standard for the diagnosis of hemodynamically significant CAD. CT-derived FFRCT and CT perfusion are two emerging techniques that can provide a functional assessment of CAD for risk stratification and clinical decision making. Several clinical studies have shown that the diagnostic performance of concomitant CCTA and functional CT assessment for detecting hemodynamically significant CAD is at least non-inferior to that of other routinely used imaging modalities. This article aims to review the current clinical evidence and recent developments in functional CT techniques.

• 한국미생물·생명공학회지
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• 제26권2호
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• pp.143-150
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• 1998

덱스트란수크라제는 sucrose를 이용하여 덱스트란의 합성을 촉진하는데 sucrose이외에 다른 탄수화물이 효소 반응기 중에 존재하는 경우에는 sucrose의 glucose기를 이 탄수화물에 전달하는 반응을 촉진하여 새로운 구조의 산물을 생산한다. Leuconostoc mesenteroides B-742CB로 부터 얻은 덱스트란수크라제를 이용하여 입자 전분과 호화 전분에 sucrose의 glucose를 수식함으로써 변형을 시도하였다. 사용한 전분의 종류(Small starch 또는 Potato starch)에 따라 그리고 전분의 상태(입자 혹은 호화된 상태)에 따라 이론적 수율의 46-72%(s.d.<${pm}$5)를 얻었다. 변형 전분을 ${alpha}$-amylase, isoamylase, pullulanase 그리고 endo-dextranase로 처리하여 변형 전의 전분과 가수분해 상태를 비교한 결과 변형전의 산물에 비해 이들 가수분해효소에 대해 저항성을 보였다. 변형에서 얻어진 산물들의 methylation결과 입자 전분을 이용한 변형 반응의 산물의 변형 정도가 더 컸으며, 변형입자를 SEM으로 관찰하면 불규칙한 크기의 작은 조각의 산물을 확인할 수 있었다. 변형 반응으로 sucrose의 glucose가 전분 glucose의 C3, C4, 그리고 C6 위치의 free-OH group에 수식된 새로운 구조의 변형 산물을 생산하였고 이는 iodine에 의한 염색 정도를 크게 감소시켰으며 용해성을 증가시켰다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.375-380
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• 2014

This study examined the incidence rates of cancer cases (averages for 2006-2010) and relationships with environmental radioactivity levels. Soil and water samples were collected from provincial and district centers of Van city and the outdoor gamma doses were determined using a portable gamma scintillation detector. Gross alpha and beta, (226)Ra, (232)Th, and (40)K activities were measured in both tap water and soil samples. Although high rates of stomach and esophagus cancers have been reported previously in Van the underlying reasons have not hitherto been defined. Incidences of cancers were highest in the Gurpmar (326.0) and Ozalp (377.1) counties (p<0.001). As to the results of the gross alpha and gross beta radioactivity measurements in the drinking water, these two counties also had high beta radionuclide levels: Gurpmar ($140mBq/dm^3$) and Ozalp ($206mBq/dm^3$). Even if within the normal range, a relation between the higher rate of the incidence of stomach and esophagus cancers with that of the higher rate of beta radionuclide activity was clear. On Spearman correlation analysis, the relation between higher beta radionuclide levels and cancer incidence was found to be statistically significant (p<0.01). According to the results of the analysis, Van residents receive an average 1.86 mSv/y annual dose from outdoor gamma radiation, ingestion of radionuclides in the drinking water, and indoor $^{222}Rn$ activity. Moreover, gross alpha and beta activities were found to be extremely high in all of the lakes around the city of Van, Turkey. Further investigations with long-term detailed environmental radiation measurements are needed regarding the relationship between cancer cases and environmental radioactivity in the city of Van.

• 대한약리학회지
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• 제24권1호
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• pp.43-52
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• 1988

국소마취제의 약리학적 작용기전을 탐구키 위하여 소의 신선한 대뇌피질로부터 synaptosomal plasma membrane vesicles(SPMV)를 분리한 후 그 소수성 중심부의 microviscosity에 미치는 국소마취제의 영향을 pyrene 형광 probe법으로 측정한 결과 lidocaine HCI과 procaine HCI이 microviscosity를 낮춘다는 것을 알았고 그 정도는 procaine HCI에 비하여 tidocaine.HCI이 더욱 컸다. 또 국소마취 제 가 dimyristoylphosphatidylcholine (DMPC) multilamellar liposomes의 상전 이온도를 낮추며 cooperative unit크기를 감소시킨다는 것도 시차 열량분석법으로 알게 되었다. 상전이온도와 cooperative unit 크기의 감소 정도는 dibucaine HCI>tetracaine HCI>lidocaine HCI > procaine HCI의 순이었다.

• The Korean Journal of Physiology and Pharmacology
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• 제13권1호
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• pp.61-70
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• 2009

We have examined the effects of certain mutations of the selectivity filter and of the membrane helix M2 on $Ba^{2+}$ blockage of the inward rectifier potassium channel, Kir 2.1. We expressed mutant and wild type murine Kir 2.1 in Chinese hamster ovary(CHO) cells and used the whole cell patch-clamp technique to record $K^+$ currents in the absence and presence of externally applied $Ba^{2+}$. Wild type Kir2.1 was blocked by externally applied $Ba^{2+}$ in a voltage and concentration dependent manner. Mutants of Y145 in the selectivity filter showed little change in the kinetics of $Ba^{2+}$ blockage. The estimated $K_d(0)$ was 108 ${\mu}M$ for Kir2.1 wild type, 124 ${\mu}M$ for a concatameric WT-Y145V dimer, 109 ${\mu}M$ for a WT-Y145L dimer, and 267 ${\mu}M$ for Y145F. Mutant channels T141A and S165L exhibit a reduced affinity together with a large reduction in the rate of blockage. In S165L, blockage proceeds with a double exponential time course, suggestive of more than one blocking site. The double mutation T141A/S165L dramatically reduced affinity for $Ba^{2+}$, also showing two components with very different time courses. Mutants D172K and D172R(lining the central, aqueous cavity of the channel) showed both a decreased affinity to $Ba^{2+}$ and a decrease in the on transition rate constant(${\kappa}_{on}$). These results imply that residues stabilising the cytoplasmic end of the selectivity filter(T141, S165) and in the central cavity(D172) are major determinants of high affinity $Ba^{2+}$ blockage in Kir 2.1.

• Archives of Pharmacal Research
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• 제20권1호
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• pp.1-6
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• 1997

We determined the microviscosity of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex and liposomes of total lipids (SPMTL) and phospholipids (SPMPL) extracted from SPMV. Changes in the microviscosity induced by the range and rate of lateral diffusion were measured by the intramolecular excimerization of 1, 3-di(1-pyrenyl)propane (Py-3-Py). The microviscosity values of the direct probe environment in SPMV, SPMTL and SPMPL were 38.17, 31.11 and 27.64 cP, respectively, at$37^{\circ}C$and the activation energies $(E_a)$ of the excimer formation of Py-3-Py in SPMV, SPMTL and SPMPL were 8.236, 7.448 amd 7.025 kcal/mol, respectively. Probe location was measured by polarity and polarizability parameters of the probe Py-3-Py and probe analogues, pyrene, 1-pyrenenonanol and 1-pyrenemethyl-3${\beta}$-hydroxy-22, 23-bisnor-5-cholenate (PMC), incorporated into membranes or solubilized in reference solvents. There existed a good linear relationship between the first absorption peak of the $^1_a$ band and the polarizability parameter $(n^{2}-1)/(2n^{2}+1)$.The calculated refractive index values for SPMV, SPMTL and SPMPL were close to 1.50, which is higher than that of liquid paraffin (n=l.475). The probe location was also determined by using a polarity parameter $(f-1/2f^{I})$. Here f=$({\varepsilon}-1)/(2{\varepsilon}+1)$ is the dielectric constant function and $f^I=(n^2-1)/(2n^2+1)$ is the refractive index function. A correlation existed between the monomer fluorescence intensity ratio and the solvent polarity parameter. The probes incorporated in SPMV, SPMTL, and SPMPL report a polarity value close to that of 1-hexanol $({\varepsilon}=13.29)$. In conclusion, Py-3-Py is located completely inside the membrane, not in the very hydrophobic core, but displaced toward the polar head groups of phospholipid molecules, e.g., central methylene region of aliphatic chains of phospholipid molecules.

• Molecules and Cells
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• 제20권2호
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• pp.235-240
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• 2005

Extracts of pine needles (Pinus densiflora Sieb. et Zucc.) have diverse physiological and pharmacological actions. In this study we show that pine needle extract alters pacemaker currents in interstitial cells of Cajal (ICC) by modulating ATP-sensitive $K^+$ channels and that this effect is mediated by prostaglandins. In whole cell patches at $30^{\circ}C$, ICC generated spontaneous pacemaker potentials in the current clamp mode (I = 0), and inward currents (pacemaker currents) in the voltage clamp mode at a holding potential of -70 mV. Pine needle extract hyperpolarized the membrane potential, and in voltage clamp mode decreased both the frequency and amplitude of the pacemaker currents, and increased the resting currents in the outward direction. It also inhibited the pacemaker currents in a dose-dependent manner. Because the effects of pine needle extract on pacemaker currents were the same as those of pinacidil (an ATP-sensitive $K^+$ channel opener) we tested the effect of glibenclamide (an ATP-sensitive $K^+$ channels blocker) on ICC exposed to pine needle extract. The effects of pine needle extract on pacemaker currents were blocked by glibenclamide. To see whether production of prostaglandins (PGs) is involved in the inhibitory effect of pine needle extract on pacemaker currents, we tested the effects of naproxen, a non-selective cyclooxygenase (COX-1 and COX-2) inhibitor, and AH6809, a prostaglandin EP1 and EP2 receptor antagonist. Naproxen and AH6809 blocked the inhibitory effects of pine needle extract on ICC. These results indicate that pine needle extract inhibits the pacemaker currents of ICC by activating ATP-sensitive $K^+$ channels via the production of PGs.

• 대한약리학회지
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• 제29권1호
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• pp.149-156
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• 1993

Ethanol이 암세포 증식 속도에 미치는 직접적인 영향 검색의 일환으로 배양된 mouse myeloma cell line Sp2/0-Ag14로부터 분리한 형질막 (Sp2/0-PMV) 유동성에 미치는 ethanol의 영향을 형광분석법으로 측정하였다. 그 결과 ethanol은 Sp2/0-PMV 지질 이중층 측방확산운동의 범위와 속도를 증가시켰고 회전확산운동 범위도 증가시켰다. 특히 ethanol은 Sp2/0-PMV 지질이중층 중 내부단층 (inner monolayer)에 비하여 비교적 선택적으로 외부단층 (outer monolayer)의 회전확산운동 범위를 증가시킨다는 것을 확인하였다.

• 한국미생물·생명공학회지
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• 제26권2호
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• pp.179-186
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• 1998

본 연구에서는 dextransucrase hyper-producing Leuconostoc mesenteroides B-512FMCM과 dextransucrase constitutive mutants인 B-742CB 및 B-1355C에서 얻은 dextransucrase 및 alternansucrase를 이용하여 maltose, lactose, gentiobios 및 raffinose의 수용체반응을 수행하였다. B-512FMCM의 경우 수용체로서 maltose와 gentiobiose는 설탕에 대한 농도비가 1/1이하일 때 수용체에 ${alpha}$l-6으로 D-glucose가 결합한 일련의 올리고당을 생성하였고, 9/1이상에서는 단 두 가지의 수용체산물로서 maltose의 경우에는 panose와 isomaltosyl maltose를, gentiobiose의 경우에는 6$^2$-${alpha}$-D-glucopyranosyl gentiobiose와 isomaltosyl gentiobiose만을 생성하였다. 그러나 lactose는 유일한 산물인 2$^1$-${alpha}$-D-glycopyranosyl lactose만을 생성하였다. 효소양의 변화에 대해서 maltose와 gentiobiose의 수용체반응에서 생성된 수용체산물(올리고당)의 수와 양은 효소양이 증가함에 따라 증가하였으나 lactose의 경우에는 효소양의 증가에 대해 수용체산물 양의 변화가 크지 않았다. B-742CB dextransucrase와 B-1355C alternansucrase를 사용하면 B-512FMCM dextransucrase에서는 단 한가지만의 수용체산물을 생산하였던 lactose와 raffinose를 수용체로 하여 여러 가지의 수용체산물(올리고당)을 생산하였다.

• Animal Bioscience
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• 제36권5호
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• pp.740-752
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• 2023

Objective: Dietary phytase increases bioavailability of phytate-bound phosphorus (P) in pig nutrition affecting dietary calcium (Ca) to P ratio, intestinal uptake, and systemic utilization of both minerals, which may contribute to improper bone mineralization. We used phytase to assess long-term effects of two dietary available P (aP) levels using a one-phase feeding system on gene expression related to Ca and P homeostasis along the intestinal tract and in the kidney, short-chain fatty acids in stomach, cecum, and colon, serum, and bone parameters in growing gilts and barrows. Methods: Growing pigs (37.9±6.2 kg) had either free access to a diet without (Con; 75 gilts and 69 barrows) or with phytase (650 phytase units; n = 72/diet) for 56 days. Samples of blood, duodenal, jejunal, ileal, cecal, and colonic mucosa and digesta, kidney, and metacarpal bones were collected from 24 pigs (6 gilts and 6 barrows per diet). Results: Phytase decreased daily feed intake and average daily gain, whereas aP intake increased with phytase versus Con diet (p<0.05). Gilts had higher colonic expression of TRPV5, CDH1, CLDN4, ZO1, and OCLN and renal expression of TRPV5 and SLC34A3 compared to barrows (p<0.05). Phytase increased duodenal expression of TRPV5, TRPV6, CALB1, PMCA1b, CDH1, CLDN4, ZO1, and OCLN compared to Con diet (p<0.05). Furthermore, phytase increased expression of SCL34A2 in cecum and of FGF23 and CLDN4 in colon compared to Con diet (p<0.05). Alongside, phytase decreased gastric propionate, cecal valerate, and colonic caproate versus Con diet (p<0.05). Phytase reduced cortical wall thickness and index of metacarpal bones (p<0.05). Conclusion: Gene expression results suggested an intestinal adaptation to increased dietary aP amount by increasing duodenal trans- and paracellular Ca absorption to balance the systemically available Ca and P levels, whereas no adaption of relevant gene expression in kidney occurred. Greater average daily gain in barrows related to higher feed intake.