• Title/Summary/Keyword: Functional activation

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PDTC Inhibits $TNF-{\alpha}-Induced$ Apoptosis in MC3T3E1 Cells

  • Chae, Han-Jung;Bae, Jee-Hyeon;Chae, Soo-Wan
    • The Korean Journal of Physiology and Pharmacology
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    • v.7 no.4
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    • pp.199-205
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    • 2003
  • Osteoblasts are affected by TNF-${\alpha}$ overproduction by immune cells during inflammation. It has been suggested that functional $NF-{\kappa}B$ sites are involved in TNF-${\alpha}$-induced bone resorption. Thus, we explored the effect of pyrrolidine dithiocarbamate (PDTC), which potently blocks the activation of nuclear factor $(NF-{\kappa}B)$, on the induction of TNF-${\alpha}$-induced activation of JNK/SAPK, AP-1, cytochrome c, caspase and apoptosis in MC3T3E1 osteoblasts. Pretreatment of the cells with PDTC blocked TNF-${\alpha}$-induced $NF-{\kappa}B$ activation. TNF-${\alpha}$-induced activation of AP-1, another nuclear transcription factor, was suppressed by PDTC. The activation of c-Jun N-terminal kinase, implicated in the regulation of AP-1, was also down regulated by PDTC. TNF-${\alpha}$-induced apoptosis, release of cytochrome c and subsequent activation of caspase-3 were abolished by PDTC. TNF-${\alpha}$-induced apoptosis was partially blocked by Ac-DEVD-CHO, a caspase-3 inhibitor, suggesting that caspase-3 is involved in TNF-${\alpha}$-mediated signaling through $NF-{\kappa}B$ in MC3T3E1 osteoblasts. Thus, these results demonstrate that PDTC, has an inhibitory effect on TNF-${\alpha}$-mediated activation of JNK/SAPK, AP-1, cytochrome c release and subsequent caspase-3, leading to the inhibition of apoptosis. Our study may contribute to the treatment of TNF-${\alpha}$-associated immune and inflammatory diseases such as rheumatoid arthritis and periodontal diseases.

Joint Position Effects on Biceps Femoris and Peroneal Muscle Activation and Ankle Evertor Strength

  • Do-eun Lee;Jun-hee Kim;Seung-yoon Han;Oh-yun Kwon
    • Physical Therapy Korea
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    • v.31 no.2
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    • pp.114-122
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    • 2024
  • Background: The peroneus longus (PL) and peroneus brevis (PB) function as the primary muscles of eversion, a movement closely associated with tibial external rotation for ankle mortise stability. Ankle motion and tibial rotation vary based on different ankle and knee positions. Objects: This study aimed to investigate the PL, PB, and biceps femoris (BF) muscle activation and eversion strength during side-lying isometric eversion exercise based on different ankle positions (neutral [N] and plantarflexion [PF]) and knee positions (90° flexion [KF] and extension [KE]). Methods: Thirty healthy adults with an Ankle Joint Functional Assessment Tool score of ≥ 22 were recruited (mean age = 24.8 ± 3.1 years). Maximal isometric eversion strength and submaximal muscle activation of the PL, PB and BF were measured during isometric eversion exercise in side-lying. A 2 × 2 repeated measures analysis of variance was performed to investigate differences in muscle activation and strength. Results: The PL and PB muscle activation showed significant main effects with the knee and ankle positions (p < 0.05); activation was greater in the KE and PF positions than in the KF and N positions. The BF muscle activation showed a significant interaction effect with knee and ankle positions, which was greater in knee extension and ankle plantarflexed (KEPF) position than in knee flexion and ankle plantarflexed (KFPF) position (p < 0.05). Eversion strength showed a significant main effect only in ankle position (p < 0.05) and was greater in the N position than in the PF position. Conclusion: The results of this study indicate that the KEPF position can be recommended to facilitate contraction of the PL and PB during side-lying eversion exercise. Furthermore, the effects of the knee-ankle positions should be considered for measuring ankle eversion strength and implementing the isometric submaximal side-lying eversion exercise.

Somatotopic Mapping of the Supplementary Motor Area (부운동영역의 뇌지도화)

  • Han Young Min;Jeong Su-Hyun;Lee Heon;Jin Gong Yong;Lee Sang Yong;Chung Gyung Ho
    • Investigative Magnetic Resonance Imaging
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    • v.8 no.1
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    • pp.9-16
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    • 2004
  • Purpose : The purpose of this study was to assess supplementary motor area (SMA) activation during motor, sensory, word generation, listening comprehension, and working memory tasks using functional magnetic resonance imaging (fMRI). Materials and Methods : Sixteen healthy right-handed subjects (9M, 7F) were imaged on a Siemens 1.5T scanner. Whole brain functional maps were acquired using BOLD EPI sequences in the axial plane. Each paradigm consisted of five epochs of activation vs. the control condition. The activation tasks consisted of left finger complex movement, hot sensory stimulation of the left hand, word generation, listening comprehension, and working memory. The reference function was a boxcar waveform. Activation maps were thresholded at an uncorrected p=0.0001. The thresholded activation maps were placed into MNI space and the anatomic localization of activation within the SMA was compared across tasks. Results : SMA activation was observed in 16 volunteers for the motor task, 11 for the sensory task, 15 for the word generation task, 5 for the listening comprehension task, and 15 for the working memory task. The rostral aspects of the SMA showed activity during the word generation and working memory tasks, and the caudal aspects of the SMA showed activity during the motor and sensory tasks. Right (contralateral) SMA activation was observed during the motor and sensory tasks, and left SMA activation during the word generation and memory tasks. Conclusion : Our results suggest that SMA is involved in a variety of functional tasks including motor, sensory, word generation, and working memory. The results obtained also support the notion that functionally specific subregions exist within the region classically defined as the SMA.

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Comparison of Brain Activation Images Associated with Sexual Arousal Induced by Visual Stimulation and SP6 Acupuncture : fMRI at 3 Tesla (시각자극과 삼음교 자침으로 유발된 성적 흥분의 대뇌 활성화 영상의 비교 : 3 테슬라 기능적 자기공명영상법)

  • Choi, Nam-Gil;Han, Jae-Bok;Jang, Seong-Joo
    • Journal of radiological science and technology
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    • v.32 no.2
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    • pp.183-194
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    • 2009
  • Purpose : This study was performed not only to compare the brain activation regions associated with sexual arousal induced by visual stimulation and SP6 acupuncture, but also to evaluate its differential neuro-anatomical mechanism in healthy women using functional magnetic resonance imaging (fMRI) at 3 Tesla (T). Subjects and methods : A total of 21 healthy right-handed female volunteers (mean age 22 years, range 19 to 32) underwent fMRI on a 3T MR scanner. The stimulation paradigm for sexual arousal consisted of two alternating periods of rest and activation. It began with a 1-minute rest period, 3 minutes of stimulation with either of an erotic video film or SP6 acupuncture, followed by 1-minute rest. In addition, a comparative study on the brain activation patterns between an acupoint and a shampoint nearby GB37 was performed. The fMRI data were obtained from 20 slices parallel to the AC-PC line on an axial plane, giving a total of 2,000 images. The mean activation maps were constructed and analyzed by using the statistical parametric mapping (SPM99) software. Results : As comparison with the shampoint, the acupoint showed 5 times and 2 times higher activities in the neocortex and limbic system, respectively. Note that brain activation in response to stimulation with the shampoint was not observed in the regions including the HTHL in the diencephalon, GLO and AMYG in the basal ganglia, and SMG in the parietal lobe. In the comparative study of visual stimulation vs. SP6 acupuncture, the mean activation ratio of stimulus was not significantly different to each other in both the neocortex and the limbic system (p < 0.05). The mean activities induced by both stimuli were not significantly different in the neocortex, whereas the acupunctural stimulation showed higher activity in the limbic system (p < 0.05). Conclusions : This study compared the differential brain activation patterns and the neural mechanisms for sexual arousal, which were induced by visual stimulation and SP6 acupuncture by using 3T fMRI. These findings will be useful to understand the theory of traditional acupuncture and acupoint channel in scientific point of view.

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Differences between 20s and 40s in Activation of the Parietal and Frontal Areas during Visuospatial Task (공간 과제 수행 시 20대와 40대의 두정엽과 전두엽에서의 활성화 차이)

  • You, Ji-Hye;Hong, Yong-Pyo;Lee, Hang-Woon;Lee, Soo-Yeol;Chung, Soon-Cheol
    • Journal of Biomedical Engineering Research
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    • v.27 no.6
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    • pp.318-322
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    • 2006
  • The purpose of this study is to examine differences between 20s and 40s in visuospatial performance and brain activation areas using functional Magnetic Resonance Imaging (fMRI). Eight male college students in their twenties ($21.5{\pm}2.3$ years old) and six male adults in their forties ($45.7{\pm}2.6$ years old) who were graduated from college participated in the study. A visuospatial task was presented while brain images were acquired by a 3T fMRI system. Compared to the 20s the 40s showed lower visuospatial performance. There were more activations observed at the parietal and superior frontal areas at 20s compared to 40s. There were more activations observed at the middle frontal and occipital areas at 40s compared to 20s. The results of this study show that the lowering of visuospatial performance with aging was correlated to the decrease of activation area at the parietal lobe and the change of activation area at the frontal lobe.

Effects of Proprioceptive Neuromuscular Facilitation Leg Patterns on Activity of Gluteus Medius at Opposite Side (PNF 하지 패턴이 반대측 중둔근의 활성도에 미치는 영향)

  • Park, In-Suk;Lee, Sang-Yeol
    • PNF and Movement
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    • v.14 no.3
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    • pp.195-202
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    • 2016
  • Purpose: This study investigates the influence of applying proprioceptive neuromuscular facilitation (PNF) leg patterns on the activation of three types of mesogluteal fibers at the opposite side. Methods: The target subjects of this study were 19 healthy men who voluntarily agreed to participate in the program. For all subjects, the following four PNF leg patterns were applied while they were in a standing position, and then, the activation of the gluteus medius at the opposite side was measured: (1) flexion abduction internal rotation pattern, (2) flexion adduction external rotation pattern, (3) extension abduction internal rotation pattern, and (4) extension adduction external rotation pattern. In each position, a pattern was executed three times in 5 s, and the average of each measurement was used for the statistics. Results: Among the PNF leg patterns, the activation of the mesogluteal fibers at the opposite side was most significant under the application of the extension abduction internal rotation pattern. The activation of the back muscular fiber was significantly high under the application of the flexion abduction internal rotation pattern. Conclusion: Selective application of PNF leg patterns can improve the functional activity of each mesogluteal fiber.

Cortical Activation in the Human Brain induced by Transcranial Direct Current Stimulation (경두개 직류전류 자극이 대뇌피질의 뇌 활성도에 미치는 영향)

  • Kwon, Yong-Hyun;Kim, Chung-Sun;Jang, Sung-Ho
    • The Journal of Korean Physical Therapy
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    • v.21 no.4
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    • pp.73-79
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    • 2009
  • Purpose: Recently, neurostimulation studies involving manipulation of cortical excitability of the human brain have been increasingly attempted. We investigated whether transcranial direct current stimulation (tDCS) applied to the underlying cerebral cortex, directly induces cortical activation during fMRI scanning. Methods: We recently recruited five healthy subjects without a neurological or psychiatric history and who were right-handed, as verified by the modified Edinburg Handedness Inventory. fMRI was done while constant anodal tDCS was delivered to the underlying SM1 area?? immediately after the pre-stimulation for eighteen minutes. Results: Group analysis yielded an averaged map that showed that the SM1 area and the superior parietal cortex in the ipsilateral hemisphere were activated. The voxel size and peak intensity were, respectively, 82 and 5.22 in the SM1, and 85 and 5.77 in the superior parietal cortex. Conclusion: Cortical activation can be induced by constant anodal tDCS of the underlying motor cortex. This suggests that tDCS may be an effective therapeutic device for enhancing? physical motor function by modulating neural excitability of the motor cortex.

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A Quantitative Analysis of Activation Pattern of Active Elbow Muscles (주관절 근육의 활성화 유형에 대한 정량적 분석)

  • Lee, Du-Hyoung;Lee, Young-Seock;Lee, Jin;Kim, Sung-Hwan
    • Journal of Biomedical Engineering Research
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    • v.18 no.4
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    • pp.413-420
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    • 1997
  • In this paper, we analyzed the contraction patterns of active elbow muscles during isometric, concentric and eccentric contraction. The analysis parameters consist of frequency domain parameters (mean frequency, median frequency, peak frequency, peak power, skewness, kurtosis) and time domain paraseters (zero crossing, positive maxima, integrated EMG). The results of this study were as follows; The BR/BB of isometric contraction appeared to be Venter as the elbow joint was more extended. The BR /BB during concentric and eccentric contraction tended to increase with more extension of the elbow joint angle, but there was no significant difference between concentric and eccentric contraction. Further, the EMG power spectrum due to the type of contraction were different betwen eccentric and concentric contraction. According to the results, it was found that the activation pattern in elbow flexor muscles was different during three different muscle contraction pattern. Therefore, elbow flexor muscles should not be considered a single functioning unit. Especially, at the time domain analysis, IEMG is a dominant parameter for analysis of activation patterns, and the skewness kurtosis can be useful parameters in functional recognition for prosthesis control purpose.

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