• 제목/요약/키워드: Cardiac activity

검색결과 373건 처리시간 0.023초

Nesfatin-1 as a New Potent Regulator in Reproductive System

  • Kim, Jinhee;Yang, Hyunwon
    • 한국발생생물학회지:발생과생식
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    • 제16권4호
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    • pp.253-264
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    • 2012
  • Nesfatin-1 is a recently discovered anorexigenic peptide which is distributed in several brain areas implicated in the feeding and metabolic regulation. Recently, it has been reported that nesfatin-1 is expressed not only in brain, but also in peripheral organs such as digestive organs, adipose tissues, heart, and reproductive organs. Nesfatin-1 is markedly expressed in the pancreas, stomach and duodenum. Eventually, the nesfatin-1 expression in the digestive organs may be regulated by nutritional status, which suggests a regulatory role of peripheral nesfatin-1 in energy homeostasis. Nesfatin-1 is also detected in the adipose tissues of humans and rodents, indicating that nesfatin-1 expression in the fat may regulate food intake independently, rather than relying on leptin. In addition, nesfatin-1 is expressed in the heart as a cardiac peptide. It suggests that nesfatin-1 may regulate cardiac function and encourage clinical potential in the presence of nutrition-dependent physio-pathologic cardiovascular diseases. Currently, only a few studies demonstrate that nesfatin-1 is expressed in the reproductive system. However, it is not clear yet what function of nesfatin-1 is in the reproductive organs. Here, we summarize the expression of nesfatin-1 and its roles in brain and peripheral organs and discuss the possible roles of nesfatin-1 expressed in reproductive organs, including testis, epididymis, ovary, and uterus. We come to the conclusion that nesfatin-1 as a local regulator in male and female reproductive organs may regulate the steroidogenesis in the testis and ovary and the physiological activity in epididymis and uterus.

Effects of Morphine on Somatosyrnpathetic Reflex and Arterial Blood Pressure Response Evoked by Stimulation of Peripheral Nerves

  • Huh, Min-Gang;Yan, Hai-Dun;Lim, Won-Il;Kim, Jun
    • The Korean Journal of Physiology
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    • 제29권2호
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    • pp.309-321
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    • 1995
  • In the present study, the relationship between the somatosympathetic reflexes and arterial blood pressure responses to electrical stimulation of the peripheral nerve was investigated in cats anesthetized with ${\alpha}-chloralose$. Single sympathetic postganglionic fiber activities were recorded from the hindlimb muscle and skin nerves and also from the cervical and abdominal sympathetic chains. Effects of the morphine on responses of the sympathetic nerve and arterial blood pressure to activation of the peripheral $A{\delta}-$ and C-afferent nerves were analyzed. The following results were obtained. 1) Arterial blood pressure was depressed by peripheral AS-afferent stimulation (A-response) and was elevated during C-afferent activation (C-response). 2) Intravenously administered morphine enhanced the C-response while the A-response decreased insignificantly, Only the C-response was decreased by intrathecal morphine. 3) All the ten recorded cutaneous sympathetic fibers showed periodic discharge pattern similar to respiratory rhythm and five of them also showed cardiac-related rhythm. However, most of the muscular sympathetic fibers had cardiac-related rhythm and only four fibers showed respiratory rhythm. 4) Morphine decreased the sympathetic C-reflex elicited by the peripheral C-afferent activation and the abdominal sympathetic A-reflex was also decreased by morphine. From the above results, it was concluded that supraspinal mechanisms were involved in the enhanced arterial pressor response to peripheral C-afferent activation by intravenous morphine.

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Effects of Histamine $H_2-Receptor$ Stimulation on $Mg^{2+}$ Efflux in Perfused Guinea Pig Heart

  • Kang, Hyung-Sub;Chang, Sung-Eun;Kang, Chang-Won;Chae, Soo-Wan;Kim, Jin-Sang
    • The Korean Journal of Physiology and Pharmacology
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    • 제2권1호
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    • pp.49-54
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    • 1998
  • $Mg^{2+}$ is an important regulator of many cardiac functions. However, regulation of intracellular $Mg^{2+}$ activity in the heart is not well characterized. To assess the effect of histamine $H_2$-receptor stimulation on intracellular $Mg^{2+}$ regulation, changes in extracellular $Mg^{2+}$ concentration were examined under a variety of conditions in perfused guinea pig hearts. $Mg^{2+}$ in the cardiac perfusate was measured by atomic absorbance spectrophotometry. The histamine ($10^{-6}$ M) inuced a marked $Mg^{2+}$ efflux from the heart. The $H_2$-receptor antagonists, cimetidine ($10^{-6}$ M), ranitidined ($10^{-5}$ M), but not a H1-receptor antagonist, diphenhydramine ($3{\times}10^{-6}$ M), completely blocked the histamine-induced $Mg^{2+}$ efflux. The $Mg^{2+}$ efflux could also be induced by forskolin ($3{\times}10^{-6}$ M), 8-Cl-cAMP ($2{\times}10^{-4}$ M), permeable cAMP analogue, or dimaprit, ($10^{-5}$ M). However, the carbachol ($10^{-5}$ M) considerably decreased the efflux of $Mg^{2+}$. In the presence of papaverine ($10^{-5}$ M), a phosphodiesterase inhibitor, dimaprit-induced $Mg^{2+}$ efflux was potentiated. These results suggest that a significant $Mg^{2+}$ efflux from perfused guinea pig heart by histamine can be induced by the histamine $H_2$-receptor stimulation and it is suggested that cytosolic cAMP may be linked.

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Blood Pulsation의 효과가 뇌 활성화에 미치는 영향을 알아보는 방법 (Estimation Method for Brain Activities are Influenced by Blood Pulsation Effect)

  • 이원호;구정훈;이형래;한기완;박진식;김재진;윤강준;김인영;김선일
    • 대한의용생체공학회:의공학회지
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    • 제28권3호
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    • pp.338-343
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    • 2007
  • BOLD T2*-weighted MR images reflects cortical blood flow and oxygenation alterations. fMRI study relies on the detection of localized changes in BOLD signal intensity. Since fMRI measures the very small modulations in BOLD signal intensity that occur during changes in brain activity, it is also very sensitive to small signal intensity variations caused by physiologic noise during the scan. Due to the complexity of movement of various organs associated with heart beat, it is important to reduce cardiac related noise rather than other physiological noise which could be required with relatively simple method. Therefore, a number of methods have been developed for the estimation and reduction of cardiac noise in fMRI study. But, each method has limitation. In this study, we proposed a new estimation method for brain activities influenced by blood pulsation effect using regression analysis with blood pulsation signal and the correspond slice of fMRI. We could find out that the right anterior cingulate cortex and right olfactory cortex and left olfactory cortex were largely influenced by blood pulsation effect for new method. These observed areas are mostly on the structure of anterior cerebral artery in the brain. That is convinced with that our method would be valid and our new method is easier to apply in practice and reduce computational burden than the retrospective method.

Autonomic and Frontal Electrocortical Responses That Differentiate Emotions elicited by the Affective Visual Stimulation

  • Sohn, Jin-Hun;Lee, Kyung-Hwa;Park, Mi-Kyung;Eunhey Jang;Estate Sokhadze
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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    • pp.15-25
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    • 2000
  • Cardiac, respiratory, electrodermal and frontal (F3, F4) EEG responses were analyzed and compared during to slides of International Affective Picture System (IAPS) in the study on 42 students. Physiological responses during 20s of exposure to slides intended to elicit happiness (nurturant and erotic), sadness, disgust, surprise, fear or anger emotions were quite similar and were expressed in heart rate (HR) deceleration, decreased HR variability (HRV), specific SCR, increased non-specific SCR frequency (N-SCR), and EEG changes exhibited in theta increase, alpha-blocking and increased beta activity, and frontal asymmetry. However, some emotions demonstrated variations of the response magnitudes, enabling to differentiate some paris of emotions by several physiological parameters. The profiles showed higher magnitudes of HRV and EEG responses in exciting (i.e., erotic) and higher cardiac and respiratory responses in surprise. The most different pairs were exciting-surprise (by HR, HRV, theta, and alpha asymmetry), exciting-sadness (by theta, alpha, and alpha asymmetry), and exciting-fear (by HRV, theta, F3 alpha, and alpha asymmetry). Nurturant happiness yielded the least differentiation. Differences were found as well within negative emotions, e.g., anger-sadness were differentiated by HRV and theta asymmetry, while disgust-fear by N-SCR and beta asymmetry. Obtained results suggest that magnitudes of profiles of physiological variables differentiate emotions evoked by affective pictures, despite that the patterns of most responses were featured by qualitative similarity in given passive viewing context.

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Inducibility of human atrial fibrillation in an in silico model reflecting local acetylcholine distribution and concentration

  • Hwang, Minki;Lee, Hyun-Seung;Pak, Hui-Nam;Shim, Eun Bo
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권1호
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    • pp.111-117
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    • 2016
  • Vagal nerve activity has been known to play a crucial role in the induction and maintenance of atrial fibrillation (AF). However, it is unclear how the distribution and concentration of local acetylcholine (ACh) promotes AF. In this study, we investigated the effect of the spatial distribution and concentration of ACh on fibrillation patterns in an in silico human atrial model. A human atrial action potential model with an ACh-dependent $K^+$ current ($I_{KAch}$) was used to examine the effect of vagal activation. A simulation of cardiac wave dynamics was performed in a realistic 3D model of the atrium. A model of the ganglionated plexus (GP) and nerve was developed based on the "octopus hypothesis". The pattern of cardiac wave dynamics was examined by applying vagal activation to the GP areas or randomly. AF inducibility in the octopus hypothesis-based GP and nerve model was tested. The effect of the ACh concentration level was also examined. In the single cell simulation, an increase in the ACh concentration shortened $APD_{90}$ and increased the maximal slope of the restitution curve. In the 3D simulation, a random distribution of vagal activation promoted wavebreaks while ACh secretion limited to the GP areas did not induce a noticeable change in wave dynamics. The octopus hypothesis-based model of the GP and nerve exhibited AF inducibility at higher ACh concentrations. In conclusion, a 3D in silico model of the GP and parasympathetic nerve based on the octopus model exhibited higher AF inducibility with higher ACh concentrations.

고삼이 항암제 cisplatin의 췌$\cdot$심장 부작용 감소에 미치는 영향 (Inhibitory Effects of Sophora Flavescens on the Pancreatic & Cardiac Side Effects of Chemotherapy by Cisplatin)

  • 김진철;임성철;정태영;서정철;한상원
    • 동의생리병리학회지
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    • 제19권4호
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    • pp.945-949
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    • 2005
  • The objective of this study is to investigate the inhibitor effects of an traditional oriental herb, Sophora flavescens on the pancreatic & cardiac side effects of chemotherapy were studied by using Bl6-BL6 melanoma-injected C57BL6 mouse tumor model. In this study, the effects of an traditional oriental herb, Sophora flavescens, on the side effects of chemotherapy were studied using B16 melanoma-injected C57BL6 mouse tumor model. Anticancer drugs widely used in clinical situation. Sophora flavescen has significant effect on the reduction of the side effects of chemotherapy. Water extract of Sophora flavescens significantly inhibited cisplatin-induced increase of amylase (AMY) which is a good indicator of pancreatic toxicity. Sophora flavescens extract does not decrease the anti-tumor activity of cisplatin showing that it can selectively inhibit side effects of anticancer drugs preserving beneficial effect. Theses results suggest a possibility that Sophora flavescens extract can be used for cancer patients for the reduction of the side effects and improving the quality of life during chemotherapy of cancer patients.

긴급환자 상황인식 및 분석을 위한 무선 ECG모니터링 시스템 (A Wireless ECG monitoring System for Application in Life Emergency Event Detection and Analysis)

  • ;이대석;정완영
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2006년도 춘계종합학술대회
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    • pp.421-425
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    • 2006
  • 헬스케어와 무선 기술의 접목은 새로운 생체신호 모니터링 방법과 환자의 이동성 및 편의성을 제공하며 더 나은 방법으로 환자를 돌볼 수 있으며 이러한 장점으로 인해 최근 무선기술을 이용한 ECG 모니터링 및 계측 시스템이 개발되고 있다. 본 논문에서는 중요한 생체신호 중 가장 중요한 신호의 하나인 ECG 신호를 무선센서네트워크를 이용하여 무선으로 받은 후, 이를 서버컴퓨터에서 의사, 간호사 또는 환자의 보호자에게 진단의 기초자료로 제공할 수 있게 빈맥, 서맥, 동정지와 같은 비정상적인 ECG신호를 판단하는 ECG 모니터링 시스템을 구현하였다. 신체에서 계측된 ECG신호는 무선으로 서버와 RS-232로 연결된 베이스스테이션으로 전송되고 서버는 비정상적인 ECG 신호를 검사하여 저장 및 모니터링을 위해 PC/PDA로 데이터를 전송하며, 이러한 시스템을 활용하여 의료비 절감 및 더 편리한 의료서비스를 받을 수 있을 것으로 예상된다.

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Beneficial effects of andrographolide in a rat model of autoimmune myocarditis and its effects on PI3K/Akt pathway

  • Zhang, Qi;Hu, Li-qun;Li, Hong-qi;Wu, Jun;Bian, Na-na;Yan, Guang
    • The Korean Journal of Physiology and Pharmacology
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    • 제23권2호
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    • pp.103-111
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    • 2019
  • The study is to investigate effects of andrographolide on experimental autoimmune myocarditis (EAM). Lewis rats were immunized on day 0 with porcine cardiac myosin to establish EAM. The EAM rats were treated with either andrographolide (25, 50, 100 mg/kg/day) or vehicle for 21 days. An antigen-specific splenocytes proliferation assay was performed by using the cells from control rats immunized with cardiac myosin. Survival rates, myocardial pathology and myocardial functional parameters (left ventricle end-diastolic pressure, ${\pm}dP/dt$ and left ventricular internal dimension) of EAM rats received andrographolide were significantly improved. Andrographolide treatment caused an decrease in the infiltration of $CD3^+$ and $CD14^+$ positive cells in myocardial tissue. Moreover, andrographolide treatment caused a reduction in the plasma levels of tumor necrosis factor-alpha, interleukin-17 (IL-17) and myosin-antibody, and an increase in the level of IL-10 in EAM rats. Oral administration of andrographolide resulted in the decreased expression of p-PI3K, p-Akt without any change of PI3K and Akt. Further results indicate andrographolide significantly inhibited myosin-induced proliferation in splenocytes, and this effect was inhibited by co-treatment of SC79 (Akt activator). Our data indicate andrographolide inhibits development of EAM, and this beneficial effect may be due to powerful anti-inflammatory activity and inhibitory effect on PI3K/Akt pathway.

Effects of Altered Calcium Metabolism on Cardiac Parameters in Primary Aldosteronism

  • Lim, Jung Soo;Hong, Namki;Park, Sungha;Park, Sung Il;Oh, Young Taik;Yu, Min Heui;Lim, Pil Yong;Rhee, Yumie
    • Endocrinology and Metabolism
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    • 제33권4호
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    • pp.485-492
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    • 2018
  • Background: Increasing evidence supports interplay between aldosterone and parathyroid hormone (PTH), which may aggravate cardiovascular complications in various heart diseases. Negative structural cardiovascular remodeling by primary aldosteronism (PA) is also suspected to be associated with changes in calcium levels. However, to date, few clinical studies have examined how changes in calcium and PTH levels influence cardiovascular outcomes in PA patients. Therefore, we investigated the impact of altered calcium homeostasis caused by excessive aldosterone on cardiovascular parameters in patients with PA. Methods: Forty-two patients (mean age $48.8{\pm}10.9$ years; 1:1, male:female) whose plasma aldosterone concentration/plasma renin activity ratio was more than 30 were selected among those who had visited Severance Hospital from 2010 to 2014. All patients underwent adrenal venous sampling with complete access to both adrenal veins. Results: The prevalence of unilateral adrenal adenoma (54.8%) was similar to that of bilateral adrenal hyperplasia. Mean serum corrected calcium level was $8.9{\pm}0.3mg/dL$ (range, 8.3 to 9.9). The corrected calcium level had a negative linear correlation with left ventricular end-diastolic diameter (LVEDD, ${\rho}=-0.424$, P=0.031). Moreover, multivariable regression analysis showed that the corrected calcium level was marginally associated with the LVEDD and corrected QT (QTc) interval (${\beta}=-0.366$, P=0.068 and ${\beta}=-0.252$, P=0.070, respectively). Conclusion: Aldosterone-mediated hypercalciuria and subsequent hypocalcemia may be partly involved in the development of cardiac remodeling as well as a prolonged QTc interval, in subjects with PA, thereby triggering deleterious effects on target organs additively.