• Title/Summary/Keyword: Stimulation duration

검색결과 258건 처리시간 0.029초

Dopamine이 토끼 유두근의 수축력과 활동전압에 미치는 영향 (Effects of Dopamine on the Contractility and Action Potential of the Rabbit Papillary Muscle)

  • 허인회;박종완
    • 약학회지
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    • 제32권6호
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    • pp.402-414
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    • 1988
  • In order to clarify the receptor types and mechanisms underlying the positive inotropic effect of dopamine on the mammalian ventricular myocardium, the action potential, its first derivatives and isometric contraction of the rabbit papillary muscle were recorded using a force transducer and glass capillary microelectrodes filled with 3M KCl. The results were as follows; (1) In normal Tyrode solution, the contractile force was increased and duration of action potential was shortened with increments of dopamine concentration ($10^{-6}-10^{-4}M$). (2) The dose-response curve was markedly shifted to the right by pretreatment with reserpine (5mg/kg i.p., 24hrs prior to the experiment). (3) In 19mM $K^+-Tyrode$ solution, the duration of action potential, maximum rate of rise (V_{max}) of action potential and overshoot were significantly increased with increments of dopamine concentration ($10^{-6}-10^{-4}M$). (4) The inotropic effect of dopamine on the rabbit papillary muscle pretreated with reserpine was antagonized by atenolol ($10^{-6}M$), but not by phentolamine ($3{\times}10^{-6}M$). (5) In rabbit papillary muscle partially depolarized by 19mM $K^+-Tyrode$ solution, slow electrical response (calcium mediated action potential) as well as contraction were restored by dopamine ($10^{-4}M$); this restoration was blocked by calcium antagonists ($3{\times}10^{-5}M$ $LaCl_3{\cdot}6H_2O$, $3{\times}10^{-6}M$ diltiazem) or ${\beta}-adrenoceptor$ antagonist ($3{\times}10^{-6}M$ atenolol), but not affected by ${\alpha}-adrenoceptor$ antagonist ($10^{-5}M$ phentolamine, $3{\times}10^{-6}M$ yohimbine) or vascular dopaminergic receptor antagonist ($10^{-5}M$ haloperidol). The above results may be interpreted as that the positive inotropic effect of dopamine through both direct and indirect action are caused by increase in slow inward current ($Ca^{2+}$ influx into themyocardial cell), and the direct action is mainly due to the stimulation of ${\beta}-adrenoceptors$ in the rabbit papillary muscle.

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급성 및 아급성 천막상 허혈성 뇌졸중에서 발생하는 말초신경 흥분성 변화 (Altered Peripheral Nerve Excitability Properties in Acute and Subacute Supratentorial Ischemic Stroke)

  • 서정화;지기환;정은주;김상진;김응규;팽성화;배종석
    • Annals of Clinical Neurophysiology
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    • 제14권2호
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    • pp.64-71
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    • 2012
  • Background: It is generally accepted that upper motor neuron (UMN) lesion can alter lower motor neuron (LMN) function by the plasticity of neural circuit. However there have been only few researches regarding the axonal excitability of LMN after UMN injury especially during the acute stage. The aim of this study was to investigate the nerve excitability properties of the LMNs following an acute to subacute supratentorial corticospinal tract lesion. Methods: An automated nerve excitability test (NET) using the threshold tracking technique was utilized to measure multiple excitability indices in median motor axons of 15 stroke patients and 20 controls. Testing of both paretic and non-paretic side was repeated twice, during the acute stage and subacute stage. The protocols calculated the strength-duration time constant from the duration-charge curve, parameters of threshold electrotonus (TE), the current-threshold relationship from sequential sub-threshold current, and the recovery cycle from sequential supra-threshold stimulation. Results: On the paretic side, compared with the control group, significant decline of superexcitablity and increase in the relative refractory period were observed during the subacute stage of stroke. Additionally, despite the absence of statistical significance, a mildly collapsing in ('fanning in') of the TE was found. Conclusions: Our results suggest that supratentorial brain lesions can affect peripheral axonal excitability even during the early stage. The NET pattern probably suggests background membrane depolarization of LMNs. These features could be associated with trans-synaptic regulation of UMNs to LMNs as one of the "neural plasticity" mechanisms in acute brain injury.

류마티스 관절염 환자에서 Conserved T 세포 수용체의 CDR3 motif를 표현하는 제2형 콜라겐 특이 T세포주의 형성과 유지 (Generation and maintenance of type II collagen-specific T-cell line expressing conserved TCR-CDR3 motifs among patients with rheumatoid arthritis)

  • 김승훈;조미라;윤지희;박성환;조철수;황수연;김호연
    • IMMUNE NETWORK
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    • 제1권1호
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    • pp.61-69
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    • 2001
  • Background: To determine the molecular structure of type II collagen-specific T-cell receptors associated with rheumatoid arthritis (RA). Methods: We generated CII-specific T-cell lines of 8 RA patients by prolonged in vitro culture with bovine CII (bCII) and the immunogenic peptide (256-270) of human CII. The proliferation response towards CII stimulation was measured from the uptake of 3H-thymidine. Changes in the secretion of Th 1 and Th2 cytokines in the culture supernatent were measured by ELISA. The TCR clonotypes of these T-cells were examined by RT-PCR/SSCP analyses of all 22 $V_{\beta}$ chains. Results: T-cells from patients' tissue exhibited strong proliferation index upon CII stimulation, which was maintained up to 6 months in the culture. The secretion of INF-$\gamma$from these T-cells increased along with the duration of culture time, while the amount of IL-4 production did not show significant changes. The SSCP band patterns of patients' T-cells appear as discrete bands unlike the smeary streak produced from normal samples. Some SSCP bands, each representing selected expansion of a TCR containing certain subtype of $V_{\beta}$ peptides, appeared to be identical in more than one patients. Among these, the expansion of SSCP band representing the $V_{\beta}$ 14 CDR3 region persisted after switching the antigen to the immunogenic human peptide (256-270). Conclusion: CII-reactive T-cells expressing distinct CDR3 motifs are selectively expanded in the peripheral blood and synovial fluid of RA patients, and their persistent proliferation upon CII stimulation, as well as the production Th 1-type cytokines, may play pivotal roles in RA pathogenesis.

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Chronological Changes of C-Reactive Protein Levels Following Uncomplicated, Two-Staged, Bilateral Deep Brain Stimulation

  • Kim, Jae-hun;Ha, Sang-woo;Choi, Jin-gyu;Son, Byung-chul
    • Journal of Korean Neurosurgical Society
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    • 제58권4호
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    • pp.368-372
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    • 2015
  • Objective : The occurrence of acute cerebral infection following deep brain stimulation (DBS) is currently being reported with elevation of C-reactive protein (CRP) level. The aim of the present study was to establish normal range of the magnitude and time-course of CRP increases following routine DBS procedures in the absence of clinical and laboratory signs of infection. Methods : A retrospective evaluation of serial changes of plasma CRP levels in 46 patients undergoing bilateral, two-staged DBS was performed. Because DBS was performed as a two-staged procedure involving; implantation of lead and internal pulse generator (IPG), CRP was measured preoperatively and postoperatively every 2 days until normalization of CRP (post-lead implantation day 2 and 4, post-IPG implantation day 2, 4, and 6). Results : Compared with preoperative CRP levels ($0.12{\pm}0.17mg/dL$, n=46), mean CRP levels were significantly elevated after lead insertion day 2 and 4 ($1.68{\pm}1.83mg/dL$, n=46 and $0.76{\pm}0.38mg/dL$, n=16, respectively, p<0.001). The mean CRP levels at post-lead implantation day 2 were further elevated at post-IPG implantation day 2 ($3.41{\pm}2.56mg/dL$, n=46, respectively, p<0.01). This elevation in post-IPG day 2 rapidly declined in day 4 ($1.24{\pm}1.29mg/dL$, n=46, p<0.05) and normalized to preoperative value at day 6 ($0.42{\pm}0.33mg/dL$, n=46, p>0.05). Mean CRP levels after IPG implantation were significantly higher in patients whose IPGs were implanted at post-lead day 3 than those at post-lead day 5-6 ($3.99{\pm}2.80mg/dL$, n=30, and $2.31{\pm}1.56mg/dL$, n=16, respectively, p<0.05). However, there was no difference in post-IPG day 2 and 4 between them (p>0.05). Conclusion : The mean postoperative CRP levels were highest on post-IPG insertion day 2 and decreased rapidly, returning to the normal range on post-IPG implantation day 6. The duration of post-lead implantation period influenced the magnitude of CRP elevation at post-IPG insertion day 2. Information about the normal response of CRP following DBS could help to avoid unnecessary diagnostic and therapeutic efforts.

골반근육강화훈련이 산후 비뇨생식기 회복, 성생활 및 일상생활 불편감에 미치는 효과 (Effects of Intensive Pelvic Floor Muscle Exercise on Recovery of Genitourinary System, Sexual Life and Daily Life after Normal Delivery)

  • 최의순;박재순;이인숙;오정아
    • 여성건강간호학회지
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    • 제8권3호
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    • pp.412-423
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    • 2002
  • This study was designed to evaluate the effect of pelvic floor muscle exercise using biofeedback and electrical stimulation after normal vaginal delivery. The data were collected from November 1999 to April 2000 at a university hospital located in Seoul, Korea. Out of 49 women with normal vaginal delivery, 25 of experimental group(with exercise) and 24 of control group(without exercise) were questioned about lower urinary symptoms, discomfort during sexual intercourse and daily life. The maximum pressure of pelvic floor muscle contraction(MPPFMC) and duration of pelvic floor muscle contraction(DPFMC) were measured at pre-treatment, the end of treatment and 8 weeks after a treatment program. The pelvic floor muscle exercise program(using biofeedback and electrical stimulation) was applied to the experimental group twice a week for 4 weeks at the incontinence clinic and the pelvic floor muscle exercise at home for that time and more 8 weeks. Data were analyzed by t-test, $x^2$-test, Fisher's exact test and the repeated measures ANOVA. The results were as follows; 1) MPPFMC(p=0.000) and DPFMC(p=0.021) were significantly increased in the experimental group. 2) In the lower urinary symptoms, daily frequency(p=0.001), nocturia(p=0.002), incontinence episode(p=0.016), stress incontinence(p=0.012), quantity of incontinence(p=0.026), straining(p=0.041), and strength of stream(p=0.009) were significantly decreased in the experimental group. 3) Discomfort during sexual intercourse had not a significant difference between the two groups, which was not significantly decreased as time passed. 4) In the discomfort during daily life, activity restriction(p=0.042), exercise restriction (p=0.008), interpersonal relationship restriction(p=0.046), and discomfort of general life(p=0.027) showed a significant difference between the two groups, which were not significantly decreased as time passed. In conclusion, it is suggested that the pelvic floor muscle exercise using biofeedback and electrical stimulation might be a safer and more effective program for the improvement of postpartum pelvic muscle contraction.

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전침 자극이 정상 성인의 심박변동에 미치는 영향 (Effect of Electroacupuncture Stimulation on Heart Rate Variability in Healthy Adults)

  • 김민수;곽민아;장우석;이기태;정기삼;정태영;서정철;서해경;안희덕
    • Journal of Acupuncture Research
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    • 제20권4호
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    • pp.157-169
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    • 2003
  • Objective : The effects of electroacupuncture(EA) stimulation on heart rate variability(HRV) for healthy adults are investigated with power spectrum analysis(PSA) of HRV. Methods : The HRVs of every 10 minute for 22 healthy volunteers(13 men and 9 women) were measured for an hour with SA-3000P(Medicore Co., Ltd., Korea). The median age with arithmetic range of 13 men and 9 women was 26.00 years with 22.75~27.00 years. The initial 20 minutes were defined as baseline period(pre-EA period), the following 20 minutes as the EA period and the last 20 minutes as the post-EA period. In each EA periods, volunteers received EA(2Hz, 0.6~0.8ms duration, maximal tolerated stimulation without discomfort) on the right Zusanli(ST36), Shangjuxu(ST37) acupoints while supine, resting. Results : Heart rate of volunteers at post-EA period was significantly decreased compare to that of pre-EA period, while SDNN at post-EA period was significantly increased. Heart rate at EA period was significantly decreased compare to that of pre-EA period, but Ln(LF) and LF/HF at EA period were significantly increased. Ln(HF) at post-EA period was significantly decreased compare to that of EA period, while the other variables were not significantly changed. Conclusions : The results suggest that EA in healthy adults is associated with changed activity in the sympathetic and parasympathetic nervous system. Further study is needed for investigating the effects of EA on HRV and autonomic nervous system.

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침진통(鍼鎭痛) 작용에 있어서 시상 후방 층판내핵(속방핵)의 역할 (Role of Posterior Intralaminar Thalamic Nuclei in Acupuncture Analgesia in Rats)

  • 노식;민병일;윤상협
    • 대한한의학회지
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    • 제20권3호
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    • pp.36-44
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    • 1999
  • Objectives: It has been well known that electroacupuncture(EA) has an analgesic effect and there is a pain control system in the central nervous system(CNS). The pain control system is composed of three major nuclei, which are periaqueductal gray(PAG), raphe nuclei, and the pain inhibitory complex located in the spinal cord. It has been suggested that the analgesic effect of EA might be the result of activation of the pain control system in the CNS. However, there may be a possibility that other nuclei are also involved in this pain modulation. Thus, we investigated whether the posterior intralaminar thalamic nuclei (PTIN) are involved in the pain modulation. Methods: To measure the level of pain, the jaw opening reflex (JOR) was used as a pain index. The magnitude of JOR is estimated by averaging the area of 10 successive responses. JOR was evoked by tooth-pulp stimulation with bipolar electrode carrying stimulus with the following parameters: intensity ranging from 420uA to 680ulA, 0.3ms duration of square pulse, and 0.5 Hz. Hapkog($LI_4$) and Taechung ($LR_3$) were the chosen acupoints. The Hapkog point was stimulated ipsilaterally at 5V, 3 Hz, for 15min in total, and the Taechung was stimulated at 2-3 V, 3 Hz, and for a total of 15 or 30 minutes. Different intensities of stimulation were given the PITN; one was given at $300{\mu}A$ and the other was at 500uA. The position stimulated in these nuclei by Paxinos Atlas was AP; from bregma $-4.0{\sim}-4.3mm,\;L; 0.5{\sim}1.8mm,\;D;\;4.8{\sim}6.3mm$. Results: The Hapkog point had a significant analgesic effect (P<0.05). However, the Taechung point had no effect. Both types of stimulation in the PITN did not reveal any analgesic effects. Conclusions: From these results, it was suggested that the posterior intralaminar thalamic nuclei are not involved in the modulation of pain.

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The Effects of Dynamic Functional Electrical Stimulation With Treadmill Gait Training on Functional Ability, Balance Confidence and Gait in Chronic Stroke Patients

  • Cho, Young-Ki;Ahn, Jun-Su;Park, Yong-Wan;Do, Jung-Wha;Lee, Nam-Hyun;Kwon, Oh-Yun
    • 한국전문물리치료학회지
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    • 제21권4호
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    • pp.23-33
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    • 2014
  • The aim of this study was to evaluate the effects of walking on a treadmill while using dynamic functional electrical stimulation (Dynamic FES) on functional ability and gait in chronic stroke patients. This was a prospective, randomized controlled study. Twelve patients with chronic stroke (>24 months) who were under grade 3 in dorsiflexor strength with manual muscle test were included and randomized into intervention (Dynamic FES) ($n_1$=7) and control (FES) ($n_2$=5). Both the Dynamic FES group and FES group were given a neuromuscular development treatment. The Dynamic FES group has implemented a total of 60 minutes of exercise treatment and gait training with Dynamic FES application. The FES group, with the addition of applying FES while sitting, has also implemented a total of 90 minutes of gait training on treadmill after the exercise treatment. Both two groups accomplished the program, twice a week, for a total of 24 times in a 12-week period. Exercise treatment, gait training on treadmill, and both Dynamic FES and FES were implemented for 30 minutes each. Korean version activities-specific balance confidence scale (K-ABC) was measured to determine self-efficacy in balance function. Timed up and go (TUG) test was performed to evaluate the physical performance. K-ABC, TUG, Berg balance scale (BBS), modified physical performance test (mPPT) and G-walk were evaluated at baseline and at 12 weeks. After 12 weeks, statistically significant differences (p<.05) were apparent in the Dynamic FES group in the changes in K-ABC and BBS. mPPT, TUG, gait speed, stride length and stance phase duration (%) were compared with the FES group. K-ABC had higher correlation to BBS, along with mPPT to TUG. Our results suggest that walking with Dynamic FES in chronic stroke patients may be beneficial for improving their balance confidence, functional ability and gait.

고전압맥동전류자극에 의한 생검 건의 세포 이동 및 증식 증진 (Enhance of Migration and Proliferation of Cells from Tendon Biopsies by High Voltage Pulsed Current Stimulation)

  • 이재형;제갈승주;박래준
    • The Journal of Korean Physical Therapy
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    • 제14권2호
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    • pp.162-171
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    • 2002
  • 본 연구는 고전압맥동전류자극이 생검 건의 세포 이동 및 증식의 증진 여부를 규명하기 위하여 시행하였다. 닭의 심지굴근건을 적출하고 직경 2mm의 생검하여 배양하였다. 생검 건에 100 pps, 50V로 30분간 음극으로 고전압맥동전류자극한 후 생검 건을 피브린로 피복하고 6일간 배양한 후 세포의 이동거리를 측정하고 7일 후 세포증식능을 측정하였다. 대조군과 고전압맥동전류자극군의 세포 이동 거리 및 흡광도를 t-검정한 결과 고전압맥동전류자극군의 세포 이동 거리가 유의하게 증가하였으며 (t=-2.675, p<0.05), 흡광도도 유의하게 증가하였다 (t=-2.136, p<0.05). 이러한 결과는 고전압맥동 전류자극이 생검 건 섬유모세포의 성장과 증식을 유발시키고 있음을 보여주고 있으며, 이러한 결과는 고전압맥동전류자극이 섬유모세포의 세포반응을 활성화시켰음을 시사하고 있어 고전압맥동전류자극의 건손상 치유 기전의 일부를 제시하였다.

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개에서 Isoflurane 마취시 SP-6 혈위의 전침자극시간이 최소폐포농도 및 심맥관계에 미치는 영향 (Effect of Electroacupuncture at SP-6 with Different Durations on Minimum Alveolar Concentration and the Cardiovascular System under Isoflurane Anesthesia in Dogs)

  • Jeong, Seong-Mok
    • 한국임상수의학회지
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    • 제19권3호
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    • pp.283-289
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    • 2002
  • 본 연구에서는 개에서 전침술이 isoflurane 마취시의 MAC 및 심맥관계에 미치는 영향 및 전침처치시간에 따른 차이에 대하여 조사하였다. 임상적으로 건강한 19개월령, 수컷 비글견 8두를 사용하였다. 대조군, 비혈위 전기자극군, 30분간 전침군(SP-6) 및 연속 전침군(SP-6C)으로 나누어 군 당 5두씩 무작위로 최소 7일간의 휴약기를 두며 실험에 사용하였다. 전침처치는 SP-6 혈위에 2-4V 20Hz로 30분간(SP-6)또는 MAC의 측정이 끝날 때 까지 연속적으로(SP-6C) 실시하였다. SP-6C군에서의 전침자극시간은 70-90분이었다. Isoflurane으로 마취를 유도한 후 전침을 실시하고 MAC와 cardiovascular parameters를 측정 하였다. 전침 후 MAC는 SP-6 및 SP-6C 군에서 각각 21.3$\pm$8.0% 및 16.1$\pm$4.6% 씩 유의적으로 저하되었으나(p<0.05) 전침시간에 따른 유의성은 없었다. 그러나 대조군과 비혈위 전기자극군에 비해서는 유의적으로 저하되었다(p<0.05). 전침처치 후 심맥관계에는 유의성 있는 변화가 인정되지 않았다. 이상의 결과로 보아, SP-6혈위에 대한 전침은 개에서 심맥관계의 부작용을 최소화하면서isoflurane의 MAC을 유의성 있게 감소시켰으며, 이러한 효과는 30분간의 전침자극으로 충분하다고 사료된다.