• Molecules and Cells
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• 제19권2호
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• pp.268-278
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• 2005

We investigated the effect of cytosolic and extracellular $Ca^{2+}$ on $Ca^{2+}$ signals in pancreatic acinar cells by measuring $Ca^{2+}$ concentration in the cytosol($[Ca^{2+}]_c$) and in the lumen of the ER($[Ca^{2+}]_{Lu}$). To control buffers and dye in the cytosol, a patch-clamp microelectrode was employed. Acetylcholine released $Ca^{2+}$ mainly from the basolateral ER-rich part of the cell. The rate of $Ca^{2+}$ release from the ER was highly sensitive to the buffering of $[Ca^{2+}]_c$ whereas ER $Ca^{2+}$ refilling was enhanced by supplying free $Ca^{2+}$ to the cytosol with $[Ca^{2+}]_c$ clamped at resting levels with a patch pipette containing 10 mM BAPTA and 2 mM $Ca^{2+}$. Elevation of extracellular $Ca^{2+}$ to 10 mM from 1 mM raised resting $[Ca^{2+}]_c$ slightly and often generated $[Ca^{2+}]_c$ oscillations in single or clustered cells. Although pancreatic acinar cells are reported to have extracellular $Ca^{2+}$-sensing receptors linked to phospholipase C that mobilize $Ca^{2+}$ from the ER, exposure of cells to 10 mM $Ca^{2+}$ did not decrease $[Ca^{2+}]_{Lu}$ but rather raised it. From these findings we conclude that 1) ER $Ca^{2+}$ release is strictly regulated by feedback inhibition of $[Ca^{2+}]_c$, 2) ER $Ca^{2+}$ refilling is determined by the rate of $Ca^{2+}$ influx and occurs mainly in the tiny subplasmalemmal spaces, 3) extracellular $Ca^{2+}$-induced $[Ca^{2+}]_c$ oscillations appear to be triggered not by activation of extracellular $Ca^{2+}$-sensing receptors but by the ER sensitised by elevated $[Ca^{2+}]_c$ and $[Ca^{2+}]_{Lu}$.

• Journal of Preventive Medicine and Public Health
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• 제44권1호
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• pp.2-8
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• 2011

Objectives: Public release of and feedback (here after public release) on institutional (clinics and hospitals) cesarean section rates has had the effect of reducing cesarean section rates. However, compared to the isolated intervention, there was scant evidence of the effect of repeated public releases (RPR) on cesarean section rates. The objectives of this study were to evaluate the effect of RPR for reducing cesarean section rates. Methods: From January 2003 to July 2007, the nationwide monthly institutional cesarean section rates data (1 951 303 deliveries at 1194 institutions) were analyzed. We used autoregressive integrated moving average (ARIMA) time-series intervention models to assess the effect of the RPR on cesarean section rates and ordinal logistic regression model to determine the characteristics of the change in cesarean section rates. Results: Among four RPR, we found that only the first one (August 29, 2005) decreased the cesarean section rate (by 0.81 percent) and continued to have an impact period through the last observation in May 2007. Baseline cesarean section rates (OR, 4.7; 95% CI, 3.1 to 7.1) and annual number of deliveries (OR, 2.8; 95% CI, 1.6 to 4.7) of institutions in the upper third of each category at before first intervention had a significant contribution to the decrease of cesarean section rates. Conclusions: We could not found the evidence that RPR has had the significant effect of reducing cesarean section rates. Institutions with upper baseline cesarean section rates and annual number of deliveries were more responsive to RPR.

• Toxicological Research
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• 제22권3호
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• pp.245-251
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• 2006

Nitric oxide(nitrogen monoxide, NO) plays important physiological roles, but excessive generation can be toxic. NO is present in cigarette smoke at up to 1,000 ppm, and probably represents one of the greatest exogenous sources of NO to which humans are exposed. We investigated whether cigarette smoking reduces the production of endogenous NO and whether it influences the action of lipopolysaccharide(LPS) to induce nitric oxide synthase activity in mouse brain. Mice(C57BL6/J) were exposed to cigarette smoke for 8 weeks. LPS was injected intraperitoneally in single or combination with the exposure to cigarette smoke. Six hours after the injection of LPS, mice were sacrificed and sera and brains were collected. Serum concentrations of nitrate and nitrite were not charged by 4-week smoke exposure, but were significantly increased by 6 and 8 weeks of smoke exposure. Interestingly, cigarette smoke reduced the elevation in serum nitrate and nitrite concentrations produced by LPS after 4-week smoking exposure. NO synthase(NOS) activity in brain was upregulated by LPS-administration. However, cigarette smoke exposure remarkably and consistently decreased the LPS-induced activity in mouse brain. This result suggests that cigarette smoking may affect against overproduction of the endogenous NO by LPS through the inhibition of NOS activity induced by LPS in brain or by modulation of the LPS action for the induction of NOS activity. We also suggest the possibility that the exogenous NO evolved in cigarette smoke enables feedback inhibition of NOS activity or other possibility that it attenuates the toxicity of endotoxin LPS in vivo by unknown mechanisms, which should be further studied.

• The Korean Journal of Physiology
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• 제24권1호
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• pp.145-159
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• 1990

Recently, it has been suggested that the endogenous adenosine may be the mediator for the intercellular communication in the regulation of tubuloglomerular feedback control and renin release. Even though two subclasses of adenosine receptors, A1 and A2, have been described, their functional roles are controversial. The present study was undertaken to clarify the role of adenosine receptors in hypertensive rabbit caused by clamping of renal artery. Experiments were done in two-kidney one clip Goldblatt hypertensive rabbits (2K1GHR) and sham-operated normotensive rabbits. Adenosine, N6-cyclohexyladenosine (CHA) and 5'-N-ethylcarboxamidoadenosine (NECA) were infused into a renal artery. The decreases in urine volume, renal blood flow, glomerular filtration rate and excreted amounts of electrolytes caused by adenosine and CHA were significantly attenuated in 2K1CHR. However, changes in renal function caused by A2 adenosine receptor agonist, NECA, tend to be accentuated in 2K1CHR. These results suggest that the attenuation of renal effect caused by adenosine and A1 adenosine receptor agonist may be due to the modification of adenosine receptor in the kidney in Goldblatt hypertensive rabbits.

• The Korean Journal of Physiology
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• 제22권2호
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• pp.319-332
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• 1988

The regulations of renal function and renin release are influenced by neural, humoral and physical factors. During the last decade, considerable progress has been made in the identification and characterization of these extrinsic renal control systems. Mechanisms intrinsic to the kidney are also important for renal function. These include the autoregulation of blood flow, and the local control of renin secretion. Fundamental questions regarding the mechanism of these intrinsic controls remain unanswered. Recently, endogenous renal adenosine has been claimed to influence the tubuloglomerular feedback control and renin release. Two subclasses of adenosine receptors $A_1{\;}and{\;}A_2$ have been described. The present experiment was carried out to evaluate the effects of $N_6-cyclohexyladenosine$ $(CHA,{\;}A_1{\;}selective)$ and 5'-N-ethylcarbox-amide adenosine $(NECA,{\;}A_2{\;}selective)$ on the renal function and renin release in the unanesthetized rabbit. Intra-renal arterial infusion of NECA $(0.3{\sim}10.0n{\;}mole/min/rabbit)$ or CHA $(0.03{\sim}10.0n{\;}mole/min/rabbit)$ caused a prompt and dose-dependent decrease in urine volume, glomerular filtration rate (GFR), renal plasma flow (RPF), filtration fraction (FF), electrolyte excretion and free water clearance $(CH_2O)$, the effect being much more profound with CHA than with NECA. The NECA infusion resulted in a profound decrease of systemic blood pressure, but the CHA infusion did not. Both NECA and GHA infusions caused a prompt and dose-dependent decrease in renin secretion rate, again the effect being greater with CHA than with NEGA. These results suggest that both $A_1{\;}and{\;}A_2$ adenosine receptors may be involved in the intrinsic control of renal function and renin release, and that the $A_1$ receptors plays a more important role than the $A_2$ receptor in the regulation of renal fnction.

• Archives of Plastic Surgery
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• 제40권4호
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• pp.304-311
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• 2013

With an increasing emphasis on microsurgery skill acquisition through simulated training, the need has been identified for standardised training programmes in microsurgery. We have reviewed microsurgery training courses available across the six continents of the World. Data was collected of relevant published output from PubMed, MEDLINE (Ovid), and EMBASE (Ovid) searches, and from information available on the Internet of up to six established microsurgery course from each of the six continents of the World. Fellowships and courses that concentrate on flap harvesting rather than microsurgical techniques were excluded. We identified 27 centres offering 39 courses. Total course length ranged from 20 hours to 1,950 hours. Student-to-teacher ratios ranged from 2:1 to 8:1. Only two-thirds of courses offered in-vivo animal models. Instructions in microvascular end-to-end and end-to-side anastomoses were common, but peripheral nerve repair or free groin flap transfer were not consistently offered. Methods of assessment ranged from no formal assessment, where an instructor monitored and gave instant feedback, through immediate assessment of patency and critique on quality of repair, to delayed re-assessment of patency after a 12 to 24 hours period. Globally, training in microsurgery is heterogeneous, with variations primarily due to resource and regulation of animal experimentation. Despite some merit to diversity in curricula, there should be a global minimum standard for microsurgery training.

• 한국콘텐츠학회논문지
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• 제12권1호
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• pp.234-243
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• 2012

본 연구는 국내 최초로 배우를 대상으로 무대불안을 극복하기 위한 체계적인 심리기술훈련 프로그램을 구성하고, 이를 바탕으로 심리상담을 실시하여 그 현장 적용의 가능성과 효과성을 분석하고자 하였다. 이를 위해 직업극단 연기자로 활동하고 있는 배우 2명을 목적적 표본추출법으로 선정하였다. 심리기술훈련 프로그램을 크게 5단계 12회기로 구성하였으며, 기초 교육, 호흡 조절법, 점진적 이완법, 집단상담, 심박수 바이오피드백훈련, 자기집중훈련, 루틴훈련, 행동수정 및 자기강화훈련, 심상훈련 등으로 내용화되었다. 무대불안 극복을 위한 심리기술훈련과 상담을 적용한 결과, 신체적 인지적 상태불안요인 모두 훈련 적용 전보다는 긍정적인 변화를 보였으며, 내적 변화 역시 긍정적으로 유발되어 무대불안을 극복하는데 도움을 준 것으로 나타났다. 또한 배우의 자기발견, 배우와 배우간의 앙상블, 배우와 관객 사이의 교감 증진에 긍정적인 변화가 있었다. 결론적으로 배우의 무대불안 극복을 위한 심리기술훈련 및 상담은 현장 적용성과 효과성이 있는 것으로 나타났다.

• 무역상무연구
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• 제13권
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• pp.1013-1032
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• 2000

At present, the scale of Electronic Commerce through internet has been rapidly increasing due to the development of information & communication technology, and aggregated to 2.4 billion dollar in America last year (1998). The market scale of worldwide electronic commerce is also presumed to be about 130 billion dollar in 2000, and to occupy more than 20% of the whole world trade in world 2020. Since the right of trademark, despite of being effective only in registered nations on the principle of territorialism, is unified on the cyber space of internet without domestic barrier or local limitation which make it easier to conduct the distribution of information rapidly through the address-internet domain name, those are very important that the systematic dispute-solving plan on problems such as decision of its Act and international jurisdiction to be established, in an effort to prevent the newly emerging dispute instances such as trademark infringement and improper competitiveness. In addition, it is natural that on the threshold of the electronic commerce age which formed with an unified area without the worldwide specific regulation, each country including us makes haste with the enactment of "electronic commerce Act" aiming at coming into force in 1999, in keeping with getting through "non-tariff law on electronic commerce" by U. S. parliament on May, 1998. In view of the properties of electronic commerce transactions through internet, there are the large curtailment of distributive channel, surmounting of restrictions on transaction area, space and time and the easy feedback with consumer and the cheap-required capital, from which the problems may arise - registration of trademark, the trademark infringement of domain name and the protection of prestigious trademark. Therefore, it is necessary to take the counter-measure, with a view of reviewing the infringement of trademark and domain name and the instances of each national precedent and to preventing the disputes. The improvement of the persistent system should be needed to propel the harmonious protection of those holding trademark right's credit and demanders' expectant profit by way of the righteous use of trademark.

• 자원ㆍ환경경제연구
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• 제24권4호
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• pp.709-725
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• 2015

본 연구에서는 벡터오차수정모형을 이용하여 양식 넙치 산지시장의 출하량 조절이 양식 넙치가격에 미치는 영향을 검토하고자 하였다. 이를 위하여 2007년 1월 1일부터 2013년 6월 30일까지의 1kg 크기에서 형성되고 있는 양식 넙치의 위판가격과 출하량 자료를 이용하였으며, 가격과 출하량 시계열의 정상성 검정, 공적분 검정, 벡터오차수정모형(VECM)의 추정결과를 포함하고 있다. 본 연구의 주요 실증결과는 다음과 같이 요약할 수 있다. 첫째, 가격과 출하량은 확률보행과정을 따르고 있으며, 1차 적분 시계열임을 확인하였다. 둘째, 가격과 출하량 간에 공적분관계가 성립하고 있음을 보여주며, 이들 변수가 밀접히 연계되어 있음을 보여주었다. 셋째, 가격과 출하량 간 일시적인 불균형이 발생했을 때, 장기적으로 출하량 조정을 통해 불균형 상황이 72.1% 정도 해소되며, 가격 변화를 통해 불균형상황이 0.5% 정도 해소되고 있음을 보여주고 있어 가격과 출하량 간 일시적인 불균형이 발생했을 때, 피드백효과가 존재하나 출하량 조정에 의해 해소되고 있음을 보여주었다. 마지막으로, 출하량 변화율이 단기적으로 가격 변화율을 선도하며, 출하량의 감소(증가)가 가격의 상승(하락)을 초래하고 있음을 확인할 수 있다.

• Molecules and Cells
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• 제37권9호
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• pp.672-684
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• 2014

The exact causes of cell death in Parkinson's disease (PD) remain unknown despite extensive studies on PD.The identification of signaling and metabolic pathways involved in PD might provide insight into the molecular mechanisms underlying PD. The neurotoxin 1-methyl-4-phenylpyridinium ($MPP^+$) induces cellular changes characteristic of PD, and $MPP^+$-based models have been extensively used for PD studies. In this study, pathways that were significantly perturbed in $MPP^+$-treated human neuroblastoma SH-EP cells were identified from genome-wide gene expression data for five time points (1.5, 3, 9, 12, and 24 h) after treatment. The mitogen-activated protein kinase (MAPK) signaling pathway and endoplasmic reticulum (ER) protein processing pathway showed significant perturbation at all time points. Perturbation of each of these pathways resulted in the common outcome of upregulation of DNA-damage-inducible transcript 3 (DDIT3). Genes involved in ER protein processing pathway included ubiquitin ligase complex genes and ER-associated degradation (ERAD)-related genes. Additionally, overexpression of DDIT3 might induce oxidative stress via glutathione depletion as a result of overexpression of CHAC1. This study suggests that upregulation of DDIT3 caused by perturbation of the MAPK signaling pathway and ER protein processing pathway might play a key role in $MPP^+$-induced neuronal cell death. Moreover, the toxicity signal of $MPP^+$ resulting from mitochondrial dysfunction through inhibition of complex I of the electron transport chain might feed back to the mitochondria via ER stress. This positive feedback could contribute to amplification of the death signal induced by $MPP^+$.