• The Korean Journal of Physiology and Pharmacology
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• 제16권1호
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• pp.37-42
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• 2012

The aim of the present study was to elucidate the direct effects of melatonin on bladder activity and to determine the mechanisms responsible for the detrusor activity of melatonin in the isolated rat bladder. We evaluated the effects of melatonin on the contractions induced by phenylephrine (PE), acetylcholine (ACh), bethanechol (BCh), KCl, and electrical field stimulation (EFS) in 20 detrusor smooth muscle samples from Sprague-Dawley rats. To determine the mechanisms underlying the inhibitory responses to melatonin, melatonin-pretreated muscle strips were exposed to a calcium channel antagonist (verapamil), three potassium channel blockers [tetraethyl ammonium (TEA), 4-aminopyridine (4-AP), and glibenclamide], a direct voltage-dependent calcium channel opener (Bay K 8644), and a specific calcium/calmodulin-dependent kinase II (CaMKII) inhibitor (KN-93). Melatonin pretreatment ($10^{-8}{\sim}10^{-6}M$) decreased the contractile responses induced by PE ($10^{-9}{\sim}10^{-4}M$) and Ach ($10^{-9}{\sim}10^{-4}M$) in a dose-dependent manner. Melatonin ($10^{-7}M$) also blocked contraction induced by high KCl ($[KCl]_{ECF}$; 35 mM, 70 mM, 105 mM, and 140 mM) and EFS. Melatonin ($10^{-7}M$) potentiated the relaxation response of the strips by verapamil, but other potassium channel blockers did not change melatonin activity. Melatonin pretreatment significantly decreased contractile responses induced by Bay K 8644 ($10^{-11}{\sim}10^{-7}M$). KN-93 enhanced melatonin-induced relaxation. The present results suggest that melatonin can inhibit bladder smooth muscle contraction through a voltage-dependent, calcium-antagonistic mechanism and through the inhibition of the calmodulin/CaMKII system.

• 한국인구학
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• 제31권3호
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• pp.57-84
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• 2008

본 연구는 한국 여가문화의 유형과 사회계층 변수별 차이를 규명하는 한편, 계층 변수가 여가의 객관적, 주관적 차원과 삶의 만족도에 미치는 영향을 밝히는 것을 목적으로 삼는다. 전국가구에 거주하는 1376명의 성인 남녀를 대상으로 한 연구 결과를 요약하면 다음과 같다. 첫째, 여가활동의 전반적 실태를 살펴보면 여전히 가장 많이 영위되는 여가활동은 TV/DVD/비디오 보기이고 그 밖에도 주로 집에서 할 수 있는 활동들이 선호된다. 여가 유형은 "활동형"과 "음주형", "휴식형", "관계형"으로 분류되었다. 둘째, 여가의 기능은 주로 다른 사람과의 '관계'를 강화시켜주는 것이다. 여가의 목적으로는 휴식과 재충전이 가장 중시되고, 유용한 대인관계 형성이 그 다음이다. 또한 자유시간에 일 생각을 많이 하는 등 여가에 대한 효용감이 낮다. 셋째, 관계형, 활동형, 음주형 여가에서 고학력, 고소득층의 참여 정도가 확연히 높다. 휴식형 여가에서는 교육과 소득에 따른 차이가 없다. 직업별로는 학생과 주부의 참여도가 전 여가유형에서 높은 가운데, 관리/전문직 및 사무직/준전문직이 상대적으로 다양한 여가활동을 즐기고 있다. 넷째, 여가활동의 객관적 수준을 나타내는 여가활동지수에 대한 소득, 교육, 직업의 상대적 영향력을 규명한 결과 교육수준이 높을수록, 연령이 낮을수록, 소득이 높을수록 여가활동지수가 높게 나타났다. 다섯째, 여가활동지수가 여가만족도에 가장 큰 영향력을 미치는 가운데, 남성이 여성보다, 연령이 높을수록, 소득이 높을수록 여가만족도가 높다. 직종별로는 학생이 여가만족도가 높고 판매서비스직과 생산/기능/노무직은 낮다. 동거가족수는 여가만족도와 반비례한다. 활동형 여가가 가장 여가만족도가 높고 음주형 여가가 가장 낮다. 여가활동을 다양하게 자주 즐길수록 삶의 만족도가 증가하고 활동형 여가가 삶의 만족도를 가장 크게 향상시킨다.

• Biomolecules & Therapeutics
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• 제23권3호
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• pp.233-237
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• 2015

Shikonin, a natural flavonoid found in the roots of Lithospermum erythrorhizon, has been shown to possess many biological functions. The present study was undertaken to investigate the influence of shikonin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Shikonin significantly relaxed fluoride-, thromboxane $A_2$- or phorbol ester-induced vascular contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, shikonin significantly inhibited fluoride-induced increases in pMYPT1 levels and phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving the inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1 and the inhibition of MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of shikonin on agonist-induced vascular contraction regardless of endothelial function.

• 동의생리병리학회지
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• 제16권5호
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• pp.1060-1065
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• 2002

LC20 phosphorylation and PKC α play an important role in modulation of contractile activity of smooth muscle. Besides, myosin phosphatase is also related with smooth muscle contraction in signaling pathways. We previously demonstrated that Crataegi Fructus inhibited phenylephrine-induced contraction and which might be implicated in nitrite formation(Son et al., 2002). In this study, we investigated the effects of butanol fraction of Crataegi Fructus(BFFC) on the localization of α-protein kinease C(PKC α) and myosin phosphatase subnits(MPs) in freshly isolated single ferret potal vein cells, and phosphorylation of LC20 during phenylephrine stimulation. In PKC α and MPs localization, BFFC blocked its translocation from the cytosol to the cell membrane by treatment of phenylephrine. BFFC have also dephosphorylated LC20 phosphorylation by phenylephrine stimulation under basal level, but no significant. These results indicate that the relaxation effect of BFFC is associated with inhibition of PKC α activation and MPs dissociation, and thus myosin phosphatase activity may be increased.

• Biomolecules & Therapeutics
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• 제16권3호
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• pp.249-254
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• 2008

The present study was undertaken to determine whether hypoxia influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Hypoxia significantly inhibited fluoride-induced contraction regardless of endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction suggesting that other pathway such as $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, hypoxia significantly decreased fluoride-induced increase of phospho-myosin-targeting subunit of myosin light chain phosphatase (pMYPT1). Interestingly, hypoxia didn't inhibit significantly phenylephrine-induced contraction suggesting that myosin light chain kinase (MLCK) activity or thin filament regulation is less important on the hypoxia-induced vasorelaxation in the denuded muscle than Rho-kinase activity. In conclusion, this study provides the evidence and possible related mechanism concerning the vasodilation effect of hypoxia on the agonist-specific contraction in rat aortic rings regardless of endothelial function.

• Biomolecules & Therapeutics
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• 제24권1호
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• pp.57-61
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• 2016

Fisetin, a natural flavonoid found in a variety of vegetables and fruits, has been shown to possess many biological functions. The present study was undertaken to investigate the influence of fisetin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Fisetin significantly relaxed fluoride-, thromboxane $A_2$- or phorbol ester-induced vascular contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, fisetin significantly inhibited fluoride-induced increases in pMYPT1 levels and phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving the inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1 and MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of fisetin on agonist-induced vascular contraction regardless of endothelial function.

• 대한의용생체공학회:의공학회지
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• 제29권1호
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• pp.17-24
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• 2008

The aim of this paper is to report our preliminary results of investigating the spatial focalization of Zen-meditation EEG (electroencephalograph) in alpha band (8-13 Hz). For comparison, the study involved two groups of subjects, practitioners (experimental group) and non-practitioners (control group). To extract EEG alpha rhythm, wavelet analysis was applied to multi-channel EEG signals. Normalized alpha-power vectors were then constructed from spatial distribution of alpha powers, that were classified by Fuzzy C-means based algorithm to explore various brain spatial characteristics during meditation (or, at rest). Optimal number of clusters was determined by correlation coefficients of the membership-value vectors of each cluster center. Our results show that, in the experimental group, the incidence of frontal alpha activity varied in accordance with the meditation stage. The results demonstrated three different spatiotemporal modules consisting with three distinctive meditation stages normally recognized by meditation practitioners. The frontal alpha activity in two groups decreased in different ways. Particularly, monotonic decline was observed in the control group, and the experimental group showed increasing results. The phenomenon might imply various mechanisms employed by meditation and relaxation in modulating parietal alpha.

• Journal of Radiation Protection and Research
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• 제41권2호
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• pp.173-178
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• 2016

Background: In situ gamma spectrometry has been used to measure environmental radiation, assumptions are usually made about the depth distribution of the radionuclides of interest in the soil. The main limitation of in situ gamma spectrometry lies in determining the depth distribution of radionuclides. The objective of this study is to develop a method for subsurface characterization by in situ measurement. Materials and Methods: The peak to valley method based on the ratio of counting rate between the photoelectric peak and Compton region was applied to identify the depth distribution. The peak to valley method could be applied to establish the relation between the spectrally derived coefficients (Q) with relaxation mass per unit area (${\beta}$) for various depth distribution in soil. The in situ measurement results were verified by MCNP simulation and calculated correlation equation. In order to compare the depth distributions and contamination levels in decommissioning KRR site, in situ measurement and sampling results were compared. Results and Discussion: The in situ measurement results and MCNP simulation results show a good correlation for laboratory measurement. The simulation relationship between Q and source burial for the source layers have exponential relationship for a variety depth distributions. We applied the peak to valley method to contaminated decommissioning KRR site to determine a depth distribution and initial activity without sampling. The observed results has a good correlation, relative error between in situ measurement with sampling result is around 7% for depth distribution and 4% for initial activity. Conclusion: In this study, the vertical activity distribution and initial activity of $^{137}Cs$ could be identifying directly through in situ measurement. Therefore, the peak to valley method demonstrated good potential for assessment of the residual radioactivity for site remediation in decommissioning and contaminated site.

• Physical Therapy Rehabilitation Science
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• 제9권4호
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• pp.287-294
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• 2020

Objective: This study aimed to investigate the effects of an ultrasound-based bar graph proportional to the quadriceps muscle thickness as a real-time visual feedback training tool in the elderly. Design: Cross-sectional study. Methods: Twenty-four elderly persons participated in this study and were randomly divided into three groups: oral training group (n=8, group 1), ultrasound imaging group (n=8, group 2), and graph group (n=8, group 3). In the pre condition, all participants performed maximal voluntary isometric contraction (MVIC) of the quadriceps with knee extension three times with oral training. In the post condition, group 1 performed MVIC of the quadriceps with oral training, group 2 performed MVIC of the quadriceps with real-time visual feedback using ultrasound imaging, and group 3 performed MVIC of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness, three times for all groups. Muscle thickness, activity (mean, peak), tone, stiffness, logarithmic decrement, relaxation, and creep were measured in both conditions in all participants. Results: Visual feedback with a bar graph showed significant effects on muscle thickness, mean muscle activity, and peak muscle activity compared with oral training and visual feedback with ultrasound imaging (p<0.05). Conclusions: Isometric training of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness may be more effective than other methods in improving muscle thickness and muscle activity. This study presented a tool that can help increase muscle thickness in the elderly.

• 한국응용과학기술학회지
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• 제41권2호
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• pp.498-507
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• 2024

In the field of mental health care, long-term healing programs have gained widespread recognition for their effectiveness in promoting well-being. However, the efficacy of shorter-term interventions, such as 1-night 2-day programs, remains relatively understudied. The primary objective of this initiative is twofold: firstly, to enhance the overall well-being and resilience of participants, and secondly, to investigate the program's potential to ameliorate specific mental health indicators. These indicators include physical stress levels, autonomic nervous system health, brain activity, brain stress, and concentration. A 1-night 2-day mental health healing program was implemented for 560 civil servants from Jeollanam-do (mean age 47.87 yrs). The focus was on measuring changes through baseline assessments before participation and post-program assessments upon completion. Measurements included physical stress index, autonomic nervous system health, brain activity level, brain stress, and brain concentration. There was a significant decrease in physical stress, as well as a significant decrease in autonomic nervous system health (p<0.05). Although there was no significant difference in brain activity level, there was a tendency for brain activity level to stabilize in the high-frequency range. Additionally, a significant decrease in stress levels and an improvement in concentration were observed. Incorporating 1-night 2-day relaxation programs into our daily lives offers a holistic approach to caring for both our physical and mental health, providing essential moments of rejuvenation and self-care that contribute to overall well-being and fulfillment.