• Title/Summary/Keyword: Resting tension

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Changes in Nerve Excitability During Neural Stretching (신경 신장 적용 시간에 따른 신경흥분성 변화)

  • Lee, Dong-Rour;Rhee, Min-Hyung;Eom, Ju-Ri;Kim, Jong-Soon
    • PNF and Movement
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    • v.16 no.2
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    • pp.287-294
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    • 2018
  • Purpose: The neurodynamic test used to implicate symptoms arising from the nerve is proposed to selectively increase the strain of the nerve without increasing the strain of adjacent tissue, although this has not yet been established in the time of nerve tension application. This study aimed to investigate the acute effects of nerve stretching time on nerve excitability using compound nerve action potential (CNAP) analysis. Methods: Thirty healthy young adults (mean age=23.10 years) with no medical history of neurological or musculoskeletal disorder voluntarily participated in this study. Nerve excitability was assessed using the median nerve conduction velocity test. The amplitude of the CNAP was measured under three conditions: resting phase (supra-maximal stimulus, without nerve stretching), baseline phase (two-thirds of the supra-maximal stimulus, without nerve stretching), and stretch phase (two-thirds of the supra-maximal stimulus, with 1-5 minutes nerve stretching). One-way repeated measures ANOVA was conducted to compare the latency and amplitude of CNAP. A post-hoc test was analyzed using the contrast test. Results: The latency was significantly delayed after 1 min. of nerve stretching in comparison with the baseline test. However, no significant difference was found during the nerve stretching (1-5 min.). The amplitude was significantly increased by nerve stretching. Conclusion: Nerve stretching can induce nerve excitability without any nerve injury. Based on the results, more than 1 min. of nerve stretching as a neurodynamic test can be a useful method in the clinical setting.

Contractile Effects of Hemoglobin-Free Human Cerebrospinal Fluid on Isolated Porcine Cerebral Arteries

  • Baik, Yung-Hong;Kang, Seon-Young;Kook, Hyun;Chyung, Sang-Keun;Kook, Young-Johng;Kang, Sam-Suk
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.2
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    • pp.193-199
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    • 1998
  • To elucidate the mechanism involved in the cerebral vascular spasm following subarachnoid hemorrhage (SAH), the effects of the cerebrospinal fluid (CSF) obtained from the SAH patients on the resting tension and its influence on the contractile responses to various vasoactive agents and to hypoxia were investigated in isolated porcine cerebral arteries. All the CSFs containing hemoglobin (Hb) produced contraction and some Hb-free CSFs also elicited contraction. When the Hb-free CSF was separated by microfilter, the filtrate of <30,000 MW did not produce contraction, while the fraction above 30,000 MW elicited more marked contractile responses than the unfractionated CSF. The CSF contraction was significantly attenuated in the presence of indomethacin or nimodipine, whereas the contractions induced by KCl, prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$), or endothelin-1 (ET-1) were not affected by the CSF pretreatment. However, the contractile responses induced by 5-hydroxytryptamine (5-HT) and phenylephrine (PE) were markedly potentiated by the pretreatment. Hypoxia-induced vasoconstriction was significantly potentiated by the pretreatment with either unfractionated CSF or the CSF fraction of above 30,000 MW. These results suggest that unknown vasocontractile substance(s) exists in the Hb-free CSF and that the substance, with its MW above 30,000, is activated by hypoxia and acts synergistically with 5-HT and PE, and that extracellular calcium influx and cyclooxygenase are also involved in the cerebral vasoconstrictory effect of Hb-free CSF.

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Electrophysiological and Mechanical Characteristics in Human Ileal Motility: Recordings of Slow Waves Conductions and Contractions, In vitro

  • Ryoo, Seung-Bum;Oh, Heung-Kwon;Moon, Sang Hui;Choe, Eun Kyung;Yu, Sung A;Park, Sung-Hye;Park, Kyu Joo
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.6
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    • pp.533-542
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    • 2015
  • Little human tissue data are available for slow waves and migrating motor complexes, which are the main components of small bowel motility. We investigated the electrophysiological and mechanical characteristics of human ileal motility, in vitro. Ileum was obtained from patients undergoing bowel resection. Electrophysiological microelectrode recordings for membrane potential changes and mechanical tension recordings for contraction from smooth muscle strips and ileal segments were performed. Drugs affecting the enteric nervous system were applied to measure the changes in activity. Slow waves were detected with a frequency of 9~10/min. There were no cross-sectional differences in resting membrane potential (RMP), amplitude or frequency between outer and inner circular muscle (CM), suggesting that electrical activities could be effectively transmitted from outer to inner CM. The presence of the interstitial cell of Cajal (ICC) at the linia septa was verified by immunohistochemistry. Contractions of strips and segments occurred at a frequency of 3~4/min and 1~2/min, respectively. The frequency, amplitude and area under the curve were similar between CM and LM. In segments, contractions of CM were associated with LM, but propagation varied with antegrade and retrograde directions. Atropine, $N^W$-oxide-L-arginine, and sodium nitroprusside exhibited different effects on RMP and contractions. There were no cross-sectional differences with regard to the characteristics of slow waves in CM. The frequency of contractions in smooth muscle strips and ileal segments was lower than slow waves. The directions of propagation were diverse, indicating both mixing and transport functions of the ileum.

A Study on Greater yin Disease in Gangpyeong-Shanghanlun by Analyzing Four Mental Illness Cases (정신과질환 4례를 통한 강평본(康平本) 『상한론(傷寒論)』의 태음병(太陰病) 진단 고찰)

  • Ha, Hyun-yee;Yun, Hyo-joong;Lee, Sung-jun
    • 대한상한금궤의학회지
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    • v.12 no.1
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    • pp.23-48
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    • 2020
  • Objectives : This study aimed to suggest distinct signs of Greater yin disease (tàiyīnbìng, 太陰病) by researching the etymology of three terms: zi-tong (自痛), jie-ying (結硬), and yin-er (因爾), which are exclusive found only in Greater yin disease (太陰病) in Gangpyeong-shanghanlun, but not in other categories. Methods : We studied the etymologies of the three terms that are unique in Greater yin disease, then found some pathological signs that are related with them through the four mental illness cases, which include somatization, obsessive-compulsive behavior, delusion, and panic disorder. Results : Based on the definitions of each term, we diagnosed the four patients who had mental illnesses as having Greater yin disease, and we observed meaningful improvements after administering herbal medication. After Gyejigajakyak-tang administration, the Insomnia Severity Index (ISI) score decreased from 18 to 7 and the Beck's Anxiety Index (BAI) score decreased from 36 to 18 in the first case, the ISI score decreased from 27 to 16 and the BAI score decreased from 50 to 33 in the second case, and the ISI score decreased from 23 to 4 and the BAI score decreased from 34 to 5 in the third case. In the last case, the ISI and BAI scores were 16 and 22, respectively, at the first visit, and it was found that the scores had changed to 6 and 22, respectively, at the last visit. Conclusions : We found that the unique terms in Greater yin disease, including zi-tong (自痛), jie-ying (結硬), and yin-er (因爾), can be interpreted as groundless arbitrary assumption, resting strong tension, and psychological projection based on the etymological hypothesis. Therefore, we suggest these as specific signs of Greater yin disease.

Warping and porosity effects on the mechanical response of FG-Beams on non-homogeneous foundations via a Quasi-3D HSDT

  • Mokhtar Nebab;Hassen Ait Atmane;Riadh Bennai;Mouloud Dahmane
    • Structural Engineering and Mechanics
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    • v.90 no.1
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    • pp.83-96
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    • 2024
  • This paper suggests an analytical approach to investigate the free vibration and stability of functionally graded (FG) beams with both perfect and imperfect characteristics using a quasi-3D higher-order shear deformation theory (HSDT) with stretching effect. The study specifically focuses on FG beams resting on variable elastic foundations. In contrast to other shear deformation theories, this particular theory employs only four unknown functions instead of five. Moreover, this theory satisfies the boundary conditions of zero tension on the beam surfaces and facilitates hyperbolic distributions of transverse shear stresses without the necessity of shear correction factors. The elastic medium in consideration assumes the presence of two parameters, specifically Winkler-Pasternak foundations. The Winkler parameter exhibits variable variations in the longitudinal direction, including linear, parabolic, sinusoidal, cosine, exponential, and uniform, while the Pasternak parameter remains constant. The effective material characteristics of the functionally graded (FG) beam are assumed to follow a straightforward power-law distribution along the thickness direction. Additionally, the investigation of porosity includes the consideration of four different types of porosity distribution patterns, allowing for a comprehensive examination of its influence on the behavior of the beam. Using the virtual work principle, equations of motion are derived and solved analytically using Navier's method for simply supported FG beams. The accuracy is verified through comparisons with literature results. Parametric studies explore the impact of different parameters on free vibration and buckling behavior, demonstrating the theory's correctness and simplicity.

Brain-Waves Analysis according to Ego-state and OK-gram of Transactional Analysis Theory (교류분석이론의 자아상태와 인생태도에 따른 뇌파 분석)

  • Jeong, Cheon-Soo;Kim, Jung-Sam;Kim, Chong-Yeal
    • The Journal of the Korea Contents Association
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    • v.14 no.11
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    • pp.858-863
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    • 2014
  • Through this study, we found out whether to measure objectively by using Transactional Analysis(TA) evaluating their own growth and benefit of health through the change of Ego-state, the personality structure and brain waves monitoring electric signals occurring in the brain of the human biological signals. According to the results of brain-wave test, M-type is brain-waves of healthy adults and a, ${\beta}$ were dominantly observed in the occipital while not sleeping. In particular, ${\beta}$ appears widely throughout the brain during nervous or concentrating metal activities and unlike N-type experimenters, ${\beta}$ was found to be dominant in M-type experimenters even in stable condition. N-type is brain waves of healthy adults and a, ${\beta}$ were dominantly observed in the occipital while not sleeping. In particular, unlike nervous or concentrating M-type, there was no noise such as tension and blink while resting. In addition, it turned out that subjects with high levels of A ego do not return quickly to the stable state and show a lot of Blinking and swallowing saliva, noise regardless of the pattern of Egogram. And brain waves of 11 people that the difference in data of OK-gram and Ego-state is the same in all items or less than -5 showed a low amplitude of $20{\mu}V$ in general. In conclusion, this study identified that the theory of personality pattern of Transactional Analysis Theory and brain-wave findings are consistent and also found out that brain waves are also associated according to each Ego-state of Egogram.

Facilitation of serotonin-induced contraction of rat mesenteric artery by ketamine

  • Park, Sang Woong;Noh, Hyun Ju;Kim, Jung Min;Kim, Bokyung;Cho, Sung-Il;Kim, Yoon Soo;Woo, Nam Sik;Kim, Sung Hun;Bae, Young Min
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.6
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    • pp.605-611
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    • 2016
  • Ketamine is an anesthetic with hypertensive effects, which make it useful for patients at risk of shock. However, previous ex vivo studies reported vasodilatory actions of ketamine in isolated arteries. In this study, we reexamined the effects of ketamine on arterial tones in the presence and absence of physiological concentrations of 5-hydroxytryptamine (5-HT) and norepinephrine (NE) by measuring the isometric tension of endothelium-denuded rat mesenteric arterial rings. Ketamine little affected the resting tone of control mesenteric arterial rings, but, in the presence of 5-HT (100~200 nM), ketamine ($10{\sim}100{\mu}M$) markedly contracted the arterial rings. Ketamine did not contract arterial rings in the presence of NE (10 nM), indicating that the vasoconstrictive action of ketamine is 5-HT-dependent. The concentration-response curves (CRCs) of 5-HT were clearly shifted to the left in the presence of ketamine ($30{\mu}M$), whereas the CRCs of NE were little affected by ketamine. The left shift of the 5-HT CRCs caused by ketamine was reversed with ketanserin, a competitive 5-$HT_{2A}$ receptor inhibitor, indicating that ketamine facilitated the activation of 5-$HT_{2A}$ receptors. Anpirtoline and BW723C86, selective agonists of 5-$HT_{1B}$ and 5-$HT_{2B}$ receptors, respectively, did not contract arterial rings in the absence or presence of ketamine. These results indicate that ketamine specifically enhances 5-$HT_{2A}$ receptor-mediated vasoconstriction and that it is vasoconstrictive in a clinical setting. The facilitative action of ketamine on 5-$HT_{2A}$ receptors should be considered in ketamine-induced hypertension as well as in the pathogenesis of diseases such as schizophrenia, wherein experimental animal models are frequently generated using ketamine.

The characteristics of cholinergic responses in tilapia dorsal aorta (틸라피아 배대동맥의 콜린성 반응의 특성)

  • Choi, Dong-Lim;Chung, Joon-Ki
    • Journal of fish pathology
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    • v.9 no.1
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    • pp.53-63
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    • 1996
  • The present study was undertaken to investigate the physiological characteristics of the cholinergic responses in the tilapia dorsal aorta. In vessels under resting tension or precontracted with norepinephrine, acetylcholine caused only concentration-dependent vasoconstrictions. Contractile response to acetylcholine was not affected by the removal of endothelium or the application of methylene blue. Atropine, gallamine or pirenzepine shifted concentration-response curve to the right. However pirenzepine showed a similar effect on the curve only at high concentration ($1{\times}10^{-5}$M). Acetylcholine-induced vasoconstriction was not markedly influenced by indomethacin, or verapamil, but was almost abolished in the calcium-free physiological buffer solution. These results suggest that acetylcholine produces only an endothelium-independent vasoconstriction in tilapia dorsal aorta and that the contractile effect of acetylcholine is mainly mediated by the activation of $M_2$ subtype receptor, which might be associated with the extracellular calcium influx through receptor-linked calcium channel.

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Contractile Effect of Ultraviolet Light on Isolated Thoracic Aortae of Rats (흰쥐 적출 흉부대동맥근의 자외선 수축반응에 관하여)

  • Baik, Yung-Hong;Kang, Seong-Don;Kang, Jung-Chaee
    • The Korean Journal of Pharmacology
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    • v.29 no.1
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    • pp.65-72
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    • 1993
  • Ultraviolet light radiation (UVR) did not affect resting tension of isolated thoracic aortae of rats. In aortic rings contracted with phenylephrine, however, UVR produced contractile and relaxant responses in preparations with and without endothelium, respectively. The contractile response was dependent upon the duration $(10{\sim}320\;sec)$ of irradiation, while the relaxation was not. UVR-induced contractions in endothelium-intact rings were significantly potentiated by increasing the concentrations of phenylephrine from $10^{-7}M$ to $10^{-5}M$, and also by addition of $10^{-6}M$ acetylcholine, $10^{-7}M$ isoproterenol and $3.5{\times}10^{-8}M$ nitroglycerine. However, addition of $10^{-6}M$ phentolamine, or $10^{-7}M$ to $10^{-6}M$ LY83583 inhibited the contraction or reversed the contraction to a relaxation. In endothelium-removed preparations the UVR-induced relaxation was attenuated by increasing concentractions of phenylephrine, and by addition of isoproterenol, nitroglycerin, phentolamine or LY83583. These results suggest that UVR produces contractile and relaxant responses in rat thoracic aortae with and without endothelium, respectively, and that the contractile effect results from the inhibition of endothelium-derived relaxing factor (EDRF) release by UVR the inhibition of and/or is in part re-lated to some endothelium-derived contractile factors (EDCFs).

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Effect of pH Change on Vascular Smooth Muscle Contractility in Rat Superior Mesenteric Artery and Its Branches (쥐 상장간막 동맥과 그 분지에서 pH 변화가 혈관평활근 수축성에 미치는 영향)

  • Choi, Soo-Seung
    • Journal of Chest Surgery
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    • v.43 no.4
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    • pp.345-355
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    • 2010
  • Background: Extracellular and intracellular pH ($pH_o$ and $pH_i$), which can be changed in various pathological conditions such as hypoxia, affects vascular contractility. To elucidate the mechanism to alter vascular contractility by pH, the effects of pH on reactivity to vasocontracting agents, intracellular $Ca^{2+}$ influx, and $Ca^{2+}$ sensitivity in vascular smooth muscle were examined. Material and Method: Isometric contractions in rat superior mesenteric arteries (SMA) were observed. Intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) was recorded by microfluorometer using Fura-2/acetoxylmethyl ester in muscle cells. $pH_o$ was increased from 7.4 to 7.8 or decreased to 6.9 or 6.4. $pH_i$ was decreased by applying $NH_4^+$ or propionic acid or modulated by changing $pH_o$ after increasing membrane permeability using $\beta$-escin. Result: Decreases in $pH_o$ from 7.4 to 6.9 or 6.4 shifted concentration-response curve by norepinephrine (NE) or serotonin (SE) to the right and significantly increased half maximal effective concentration (EC50) to NE or SE. Increase in $pH_o$ from 7.4 to 7.8 shifted concentration-response curve by norepinephrine (NE) or serotonin (SE) to the left and significantly reduced EC50 to NE or SE. NE increased $[Ca^{2+}]_i$ in cultured smooth muscle cells from SMA and the increased $[Ca^{2+}]_i$ was reduced by decreases in $pH_o$. NE-induced contraction was inhibited by $NH_4^+$, whereas the resting tension was increased by $NH_4^+$ or propionic acid. When the cell membrane of SMA was permeabilized using ${\beta}$-escin, SMA was contracted by increasing extracellular $Ca^{2+}$ concentration from 0 to $10{\mu}M$ and the magnitude of contraction was decreased by a decrease in $pH_o$ and vice versa. Conclusion: From these results, it can be concluded that a decrease in $pH_o$ might inhibit vascular contraction by reducing the reactivity of vascular smooth muscle to vasoactive agents, $Ca^{2+}$ influx and the sensitivity of vascular smooth muscle to $Ca^{2+}$.