• 제목/요약/키워드: Co-Contraction

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Immediate Effect of Neuromuscular Electrical Stimulation on Balance and Proprioception During One-leg Standing

  • Je, Jeongwoo;Choi, Woochol Joseph
    • Physical Therapy Korea
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    • v.29 no.3
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    • pp.187-193
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    • 2022
  • Background: Neuromuscular electrical stimulation (NMES) is a physical modality used to activate skeletal muscles for strengthening. While voluntary muscle contraction (VMC) follows the progressive recruitment of motor units in order of size from small to large, NMES-induced muscle contraction occurs in a nonselective and synchronous pattern. Therefore, the outcome of muscle strengthening training using NMES-induced versus voluntary contraction might be different, which might affect balance performance. Objects: We examined how the NMES training affected balance and proprioception. Methods: Forty-four young adults were randomly assigned to NMES and VMC group. All participants performed one-leg standing on a force plate and sat on the Biodex (Biodex R Corp.) to measure balance and ankle proprioception, respectively. All measures were conducted before and after a training session. In NMES group, electric pads were placed on the tibialis anterior, gastrocnemius, and soleus muscles for 20 minutes. In VMC group, co-contraction of the three muscles was conducted. Outcome variables included mean distance, root mean square distance, total excursion, mean velocity, 95% confidence circle area acquired from the center of pressure data, and absolute error of dorsi/plantarflexion. Results: None of outcome variables were associated with group (p > 0.35). However, all but plantarflexion error was associated with time (p < 0.02), and the area and mean velocity were 37.0% and 18.6% lower in post than pre in NMES group, respectively, and 48.9% and 16.7% lower in post than pre in VMC group, respectively. Conclusion: Despite different physiology underlying the NMES-induced versus VMC, both training methods improved balance and ankle joint proprioception.

EXISTENCE OF SOLUTION OF DIFFERENTIAL EQUATION VIA FIXED POINT IN COMPLEX VALUED b-METRIC SPACES

  • Mebawondu, A.A.;Abass, H.A.;Aibinu, M.O.;Narain, O.K.
    • Nonlinear Functional Analysis and Applications
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    • v.26 no.2
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    • pp.303-322
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    • 2021
  • The concepts of new classes of mappings are introduced in the spaces which are more general space than the usual metric spaces. The existence and uniqueness of common fixed points and fixed point results are established in the setting of complete complex valued b-metric spaces. An illustration is given by establishing the existence of solution of periodic differential equations in the framework of a complete complex valued b-metric spaces.

Examination of trunk muscle co-activation during prolonged sitting in healthy adults and adults with non-specific chronic low back pain based on the O'Sullivan Classification System

  • Alameri, Mansoor;Lohman, Everett III;Daher, Noha;Jaber, Hatem
    • Physical Therapy Rehabilitation Science
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    • v.8 no.4
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    • pp.175-186
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    • 2019
  • Objective: Non-specific chronic low back pain (NS-CLBP) has been related to abnormal trunk muscle activations, but literature reported considerable variability in muscle amplitudes of NS-CLBP patients during prolonged sitting periods. Therefore, the purpose of this study was to examine the differences among homogenous NS-CLBP subgroups in muscle activity, using muscle co-contraction indices as a more objective approach, and their roles on pain development during a 1-hour period of prolonged sitting. Design: Cross-sectional study. Methods: Twenty NS-CLBP subjects with motor control impairment (MCI) [10 classified as having flexion pattern disorder, and 10 with active extension pattern disorder], and 10 healthy controls participated in the study. Subjects followed a 1-hour sitting protocol on a standard office chair. Four trunk muscle activities including amplitudes and co-contraction indices were recorded using electromyography over the 1-hour period. Perceived back pain intensity was recorded using a numeric pain rating scale every 10 minutes throughout the sitting period. Results: All study groups presented with no significantly distinctive trunk muscle activities at the beginning of sitting, nor did they change over time when pain increased to a significant level. Both MCI subgroups reported a similarly significant increase in pain behavior through mid-sitting (p<0.001). However, after mid-sitting, they significantly differed from each other in pain (p<0.01) but did not differ in the levels of muscle activation. Conclusions: This study was the first to highlight the similarities in trunk muscle activities among homogenous NS-CLBP patients related to MCI and compared them to healthy controls while sitting for an extended period of time, and the significant increase in pain over the 1-hour sitting might not be attributed to trunk muscle activation.

Anti-inflammatory effect of remifentanil in lipopolysaccharide-stimulated amniotic epithelial cells

  • Kim, Cheul-Hong;Jeong, Seong Soon;Park, Soon Ji;Choi, Eun-Ji;Kim, Yeon Ha;Ahn, Ji-Hye
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.19 no.5
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    • pp.253-260
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    • 2019
  • Background: Sometimes general anesthesia is required for dental surgery in pregnant women. Facial bone fractures or neck abscess should be treated immediately. Dental surgery, however, creates a stressful situation that can cause inflammation. Inflammatory responses are a well-known major cause of preterm labor and preterm birth. Here we demonstrate the effects of remifentanil on the factors related to preterm labor and its mechanism of action on amniotic-derived epithelial cells (WISH cells). Methods: WISH cells were exposed to lipopolysaccharide (LPS) for 24 h and co-treated with various concentrations of remifentanil. MTT assays were performed to measure cell viability. To explain the effects of remifentanil on the factors related to inflammation in WISH cells, activation of nuclear factor kappa B ($NF-{\kappa}B$) and p38 and the expression of interleukin $(IL)-1{\beta}$, tumor necrosis factor $(TNF)-{\alpha}$, cyclooxygenase (COX)2, and prostaglandin E $(PGE)_2$ were quantified using western blotting and RT-PCR, respectively. Results: Remifentanil did not affect WISH cell viability. In western blot analysis, co-treatment with remifentanil resulted in decreased phosphorylation of $NF-{\kappa}B$, and expression of COX2 and $PGE_2$ in LPS-induced inflammation, but the results were statistically significant only at low concentrations. Reduction of $IL-1{\beta}$ and $TNF-{\alpha}$ expression was also observed with RT-PCR. Conclusion: Co-treatment with remifentanil does not affect the viability of WISH cells, but reduces the expression of the factors related to inflammation, which can induce uterine contraction and preterm labor. These findings provide evidence that remifentanil may inhibit uterine contraction and preterm labor in clinical settings.

Effects of Insamjungchuntang on the Respiratory System in Experimental Animals (인삼정천탕(人蔘定喘湯)이 호흡기계(呼吸器系)에 미치는 영향(影響))

  • Kim, Ho-Soon;Shin, Jo-Young
    • The Journal of Internal Korean Medicine
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    • v.19 no.1
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    • pp.409-427
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    • 1998
  • Insamjungchuntang has been used in Korea for many centuries as a treatment for respiratory disease. The effect of Insamjungchuntang on tracheal smooth muscle is not known. The purpose of the present study is to determine the effect of Insamjungchuntang on histamine and acetylcholine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig (500 g, male) and Sprague Dawley rats (200 g, male) were killed by $CO_2$ exposure and a segment (8-10 mm) of the thoracic trachea from each rat and guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5 g loading tension. The dose of histamine (His) and acetylcholine (Ach) which evoked 50% of maximal response $(ED_{50})$ was obtained from cumulative dose response curves for histamine and acetylcholine$(10^{-7}{\sim}10^{-4}\;M)$. Contractions evoked by His ($ED_{50}$) and Ach $(ED_{50})$ were inhibited significantly by Insamjungchuntang. In guinea pig tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $38.58\(p<0.05)\;after\;10{\mu}l/ml$ Insamjungchuntang, $90.75\(p<0.01)\;after\;30{\mu}l/ml$. Insamjungchuntang and $133.17\(p<0.01)\;after\;100{\mu}l/ml$ Insamjungchuntang. In rat tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $10.0\(p<0.05)\;after\;10{\mu}l/ml$ Insamjungchuntang, $80.71\(p<0.01)\;after\;30{\mu}/ml$ Insamjungchuntang and $118.29\(p<0.01)\;after\;100{\mu}l/ml$ Insamjungchuntang. Also, in guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $45.5\(p<0.01)\;after\;10{\mu}l/ml$ lnsamjungchuntang, and $93.17\(p<0.01)\;after\;30{\mu}l/ml$. lnsamjungchuntang $134.50\(p<0.01)\;after\;100{\mu}l/ml$ Insamjungchuntang. In rat tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $37.83\(p<0.01)\;after\;10{\mu}l/ml$ lnsamjungchuntang, $90.5\(p<0.01)\;after\;30{\mu}l/ml$ Insamjungchuntang and $135.17\(p<0.01)\;after\;100{\mu}l/ml$ Insamjungchuntang. Propranolol $(10^{-7}\;M)$ slightly but significantly attenuated the inhibitory effects of Insamjungchuntang. Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$. Insamjungchuntang fell to 46.42% in guinea pig induced by acetylcholine contraction and by $100{\mu}l/ml$ Insamjungchuntang fell to 5.43% (p<0.05) in rat induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Insamjungchuntang fell to 49.0% in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Insamjungchuntang fell to 48.6% (p<0.05) in rat induced by histamine contraction. Indomethacin and methylene blue $(10^{-7}\;M)$ did not significantly alter the inhibitory effect of lnsamjungchuntang. Also, I could find the effects of lnsamjungchuntang and Insamjungchuntanggamorphine on the tracheal smooth muscle in guinea pig and rat did not change significantly. These results indicate that Insamjungchuntang can relax histamine and acetylcholine-induced contraction of guinea pig and rat tracheal smooth muscle, and that this inhibition involves sympathetic effects.

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High-pressure synchrotron X-ray diffraction study of tremolite and actinolite in various fluids

  • Kong, Mihye;Vogt, Thomas;Lee, Yongjae
    • Current Applied Physics
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    • v.18 no.11
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    • pp.1218-1224
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    • 2018
  • Pressure-dependent structural and morphological changes of two amphibole minerals, tremolite and actinolite, were investigated up to 7.0 GPa using synchrotron X-ray powder diffraction underthree different pressure transmission media (PTM): water (W), $CO_2$ and silicone oil (SI). The elastic response of tremolite and actinolite are found to be dependent on the PTM used. When using water (W) as PTM, tremolite and actinolite show normal volume contractions with bulk moduli of 74(1) and 78(1) GPa, respectively. When using $CO_2$ as PTM, we observe the formation of calcite from tremolite above 3.8(1) GPa, whereas actinolite did not show any carbonation reaction. Under silicone oil PTM, we observe modulated volume contraction behaviors in both samples, compared to water and $CO_2$ PTM, with bulk moduli in the order of 90(1) and 94(4) GPa for tremolite and actinolite, respectively.

Role of Dopamine upon Spontaneous Contraction of Isolated Rat Uterus in Diestrus State (Dopamine이 흰쥐 자궁의 자발적 수축에 미치는 영향)

  • Park, Hyoung-Jin;Sim, Yeo-Rim;Jo, Yang-Hyeok
    • The Korean Journal of Physiology
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    • v.17 no.2
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    • pp.103-107
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    • 1983
  • This experiment was undertaken to see whether dopamine has any effect on a uterine function and whether the uterus has a dopamine receptor. We used 14 female rats in the diestrus state which was identified by a vaginal smear. Under ether anesthesia, 3 pieces(1 cm length) from each side of the uterus were dissected out and mounted in 3 tissue chambers (4 cm diameter, 10 cm height) that contained Krebs-Ringer solution. The solution was continuously aerated with 95% $O_2$ containing 5% $CO_2$ and kept $37^{\circ}C$ consistantly during the whole experimental period. The spontaneous contractile activity of the isolated uterus was recorded using a force transducer. After a recovery period of 15 min in the chamber, the following experiments were carried out. In 7 rats, each piece of the uterus was received dopamine at concentrations of $10^{-4}$, $10^{-5}$ or $10^{-6}\;M$ for 10 min and then followed by domperidone at a concentration of $10^{-5}\;M$. In another 7 rats, each piece was received domperidone, a specific peripheral dopamine receptor antagonist, was administered at a concentration of $10^{-5}\;M$ for 5 min prior to dopamine at concentrations of $10^{-4}$, $10^{-5}$, or $10^{-6}\;M$. Dopamine inhibited the spontaneous uterine contraction dose-dependently (r=0.99, p<.01). The inhibited contractility by dopomine was significantly (P<.05) resumed by post-treatment of domperidone. Pre-treatment of domperidone also blocked significantly(p<.05) the inhibitory effect of dopamine. It is concluded from these results that dopamine has inhibitory role upon the spontaneous uterine contraction of the rat in the diestrus state and domperidone antagonized the inhibitory effect of dopamine. These results suggest strongly that dopamine may exert the inhibitory effect via the dopamine receptor in the rat uterus.

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Bridging Basic Knowledge and Clinical Practice in the Education of Traditional Korean Medicine: A case of Pubescent Angelica usages in Internal Bodily Elements section, Treasured Mirror of Eastern Medicine (동의보감·내경편 독활(獨活)의 용법을 통해 본 한의학 기초와 임상의 연계 교육 방안)

  • Hong, Jiseong;Kang, Inhye;Lee, Youngmi;Lee, Hoon-Yeon;Kang, Yeonseok
    • The Journal of Korean Medical History
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    • v.33 no.1
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    • pp.1-9
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    • 2020
  • Pubescent Angelica is generally used in musculoskeletal diseases of lower extremity, itching, external contraction (外感) and furuncle, with the effect of dispelling wind, draining dampness, dispersing the external (解表) and stopping pain. The disease parts of Treasured Mirror of Eastern Medicine (東醫寶鑑) contain 121 examples of the usage of Pubescent Angelica. Cases of musculoskeletal diseases and itching are mainly in the External Bodily Elements section (外形篇), and those of external contraction and furuncle are mainly in the Miscellaneous Disorder section (雜病篇). Internal Bodily Elements section (內景篇) has 10 prescriptions that involve Pubescent Angelica, in Dreams (2), Voice (1), Uterus (4), Parasites (1), and Feces (2) chapters. Their specific symptoms are insomnia and sleep paralysis (Dreams), loss of voice due to external contraction (Voice), uterine hemorrhage (Uterus), phthisis (Parasites), and constipation and diarrhea (Feces). It is not easy for students beginning their clinical training to link the effects of Pubescent Angelica and its actual usage, especially in the area of internal medicine. By Analyzing the whole cases of Pubescent Angelica in the Treasured Mirror, we found various usages out of reach of basic knowledge of the herb. Such method can be utilized not only in developing herbal knowledge-based products, but also in improving Korean medicine education, by enhancing the occupational competency bridging basic and clinical knowledge.

Effect of Acetylcholine on Electrical Activity of Cat Stomach (자율신경계에 작용하는 약물이 위장 전기도에 미치는 영향)

  • Kim, Myung-Suk;Park, Hyoung-Jin;Bai, Sun-Ho;Choi, Hyun;Kim, Chul
    • The Korean Journal of Physiology
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    • v.14 no.2
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    • pp.21-28
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    • 1980
  • In order to investigate the effect of cholinergic substance on the electrical and the mechanical activities of the stomach muscle, 10 isolated cat stomachs were studied. At various sites of a stomach muscle preparation, the electrical activity was monopolarly recorded by using capillary electrodes containing chlorided silver wires, and the isometric contractile activity was recorded simultaneously at the terminal portion of the antrum in Krebs solution$(36^{\circ}C)$ which was aerated with a gas mixture consisting of 95% $O_2$ and 5% $CO_2$. The recording of these activities were performed before (control period) and after acetylcholine$(10^{-5}M)$ and atropine $(10^{-6}M)$ administrations serially. Following results were obtained: 1) The mean frequency of the slow wave was $4.36{\pm}0.22\;cycles/min$ at all the various sites of the cat stomach. The slow wave was propagated caudad in sequence and its velosity of propagation increased as the slow wave approached the pylorus in normal Krebs solution. 2) After acetylcholine administration, the frequency of the slow wave increased transiently and the increase of slow wave frequency was followed by the isometric contraction of antral muscle in association with the second potential which succeeded the slow wave. 3) By atropine administration, the stimulatory effect of acetylcholine on the antral muscle contraction was abolished completely, and the frequency of the slow wave decreased significantly compared with that of the control period, which tendency was more prominent in the antrum. The above results suggest that the transient increase in the frequency of gastric slow wave by acetylcholine may have some influence upon the contraction mechanism of the cat antral muscle.

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A Magnetic Stimulator Adopting a Low-Frequency Fly-Back Switching Circuit (저주파 플라이백 스위칭회로를 이용한 고성능 자기자극기)

  • Yi, Jeong-Han;Kim, Hyung-Sik;Hur, Moon-Chang;Kim, Jung-Hoe
    • Journal of Biomedical Engineering Research
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    • v.27 no.6
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    • pp.343-350
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    • 2006
  • Medical magnetic stimulator generates strong magnetic field pulses. Clinical applications of the magnetic pulse are the stimulation of nervous system and the contraction of muscle. The unique source of the strong magnetic pulse is a capacitor-inductor resonator and this inductor generates a strong sinusoidal magnetic pulse by discharging the capacitor with high initial voltage. Continuous muscle contraction needs sequential generation of the magnetic pulses. However, to keep the magnitude of sequential pulses identical, an expensive high-voltage power supply have to support voltage drop of the capacitor between the pulses. A protection circuit between the supply and the resonator is necessary to protect the supply from reverse current caused by capacitor voltage reversal. In this paper, a new circuit structure of the magnetic stimulator adopting a low-frequency fly-back switching is proposed. The new circuit supports sequential pulse generation and allows the reverse current without damage. Performance of the new circuit is examined and a low-cost magnetic stimulator for urinary incontinence therapy is being developed using the presented method.