• 한국동물학회:학술대회논문집
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• 한국동물학회 2001년도 한국생물과학협회 학술발표대회
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• pp.231.1-231
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• 2001

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• Integrative Medicine Research
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• 제5권3호
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• pp.176-181
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• 2016

Recent studies have focused on evidence-based interventions to prevent mobility decline and enhance physical performance in older adults. Several modalities, in addition to traditional strengthening programs, have been designed to manage age-related functional decline more effectively. In this study, we reviewed the current relevant literatures to assess the therapeutic potential of eccentric exercises for age-related muscle atrophy (sarcopenia). Age-related changes in human skeletal muscle, and their relationship with physical performance, are discussed with reference to in vitro physiologic and human biomechanics studies. An overview of issues relevant to sarcopenia is provided in the context of the recent consensus on the diagnosis and management of the condition. A decline in mobility among the aging population is closely linked with changes in the muscle force-velocity relationship. Interventions based specifically on increasing velocity and eccentric strength can improve function more effectively compared with traditional strengthening programs. Eccentric strengthening programs are introduced as a specific method for improving both muscle force and velocity. To be more effective, exercise interventions for older adults should focus on enhancing the muscle force-velocity relationship. Exercises that can be performed easily, and that utilize eccentric strength (which is relatively spared during the aging process), are needed to improve both muscle force and velocity.

• 대한정형외과 초음파학회지
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• 제7권2호
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• pp.127-131
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• 2014

인체에서 가장 큰 기관인 골격근은 통증과 기능장애를 초래할 수 있는데, 통증 유발점이라는 특징적인 병변을 가지는 근막 통증 증후군이 골격근의 가장 흔한 병적 상황 중의 하나이다. 통증 유발점은 골격근 내의 taut band라고 불리는 띠안에 존재하는 과민한 통증성 국소 병변으로 국소 통증 뿐만 아니라 연관통 및 만성적인 관절운동 제한과도 동반된다. 다양한 치료법들이 시도되었으나 통증 유발점 주사법이 가장 효율적인 치료법으로 사용되고 있으며 이 종설에서는 근막 통증 증후군의 일반적 병인과 통증 유발 주사의 방법에 대하여 소개하고자 한다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.53-53
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• 2003

Calumenin was previously identified as a high affinity Ca$\^$2+/ binding protein in mouse cardiac sarcoplasmic reticulum (SR). For the present study, a 48 kDa skeletal homologue of calumenin was identified by sucrose-density gradient of rabbit skeletal SR membranes, concanavalin A treatment, 2D-gel electrophoresis, $\^$45/Ca$\^$2+/ overlay, Stains-all staining, and MALDI-TOF analysis. We attempted to clone the skeletal calumenin by RT-PCR based on mouse cardiac and human calumenin sequences. The deduced amino acid sequence (315 residues) of the skeletal calumenin showed high identity to mouse cardiac calumenin (90％). As seen in the cardiac calumenin, the deduced sequence contains a 19 amino acid N-terminal signal sequence and a HDEF C-terminal sequence, a putative retrieval signal to ER. Also, the skeletal calumenin contains one N-glycosylation site, three PKC phosphorylation sites, eight casein kinase 2 phosphorylation sites, and 6 EF-hand domains. GST-calumenin showed a conformational change and increased mobility in the presence of Ca$\^$2+/ in SDS-PAGE. Three calumenin interacting proteins (ryanodine receptor 1, glycogen phosphorylase, and phosphofructo kinase) were identified by pull-down assay with GST-calumenin and solubilized SR. All the interactions were Ca$\^$2+/dependent. The present results suggest that calumenin plays an important role in Ca$\^$2+/ homeostasis of muscle cells.

• Journal of Periodontal and Implant Science
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• 제45권1호
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• pp.8-13
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• 2015

Purpose: The aim of this study was to evaluate the transfer of different occlusal forces in various skeletal malocclusions using finite element analysis (FEA). Methods: Three representative human cone-beam computed tomography (CBCT) images of three skeletal malocclusions were obtained from the Department of Orthodontics, Yonsei University Dental Hospital, Seoul, South Korea. The CBCT scans were read into the visualization software after separating bones and muscles by uploading the CBCT images into Mimics (Materialise). Two separate three-dimensional (3D) files were exported to visualize the solid morphology of skeletal outlines without considering the inner structures. Individual dental impressions were taken and stone models were scanned with a 3D scanner. These images were integrated and occlusal motions were simulated. Displacement and Von Mises stress were measured at the nodes of the FEA models. The displacement and stress distribution were analyzed. FEA was performed to obtain the 3D deformation of the mandibles under loads of 100, 150, 200, and 225 kg. Results: The distortion in all three skeletal malocclusions was comparable. Greater forces resulted in observing more distortion in FEA. Conclusions: Further studies are warranted to fully evaluate the impact of skeletal malocclusion on masticatory performance using information on muscle attachment and 3D temporomandibular joint movements.

• 한국운동역학회지
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• 제17권1호
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• pp.121-127
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• 2007

Muscle force produced by muscle fibers is transmitted to bones via tendinous structures(aponeuroses and tendon), resulting in joint(s) movement. As force-transmitting elements, mechanical behavior of aponeuroses and tendon are closely related with the function of muscle-tendon complex. The purpose of this study was to determine strain characteristics of aponeuroses for in-vivo human soleus muscle during submaximal voluntary contractions using an advanced medical imaging technique, velocity-encoded phase-contrast magnetic resonance imaging (VE-PC MRI). VE-PC MRI of the soleus muscle-tendon complex was acquired during submaximal isometric plantarflexion contraction-relaxation cycle (n = 7), using 3.0T Trio MRI scanner(Siemens AG, Malvern, MA). From the VE-PC MRI containing the tissue velocity in superior-inferior direction, twenty regions of interest(20 ROI; 10 on the anterior aponeurosis and 10 on the posterior aponeurosis) were tracked. During the isometric plantarflexion contraction-relaxation cycle, velocity and displacement profiles were different between the anterior and posterior aponeuroses, indicating heterogeneous strain behavior along the length of the leg. The anterior aponeurosis elongated while the posterior aponeurosis shortened during the initial phase of the contraction. Moreover, strain behavior of the posterior aponeurosis was different from that of the Achilles tendon. Possible explanation for the observed variations in strain behavior of aponeuroses was investigated with morphological assessment of the soleus muscle and it was found that the intramuscular tendinous structures significantly vary among subjects. In conclusion, the heterogeneous mechanical behavior of the soleus aponeuroses and the Achilles tendon suggests that the complexity of skeletal muscle-tendon complex should be taken into consideration when modeling the complex for better understanding of its functions.

• Journal of Yeungnam Medical Science
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• 제16권1호
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• pp.125-130
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• 1999

저자들은 최근 25세 여자 환자로 뚜렷한 가족력이 없으면서 3-4세경부터 발생한 근육의 강직현상과 현저한 근비대소견이 있는 환자를 경험하였다. 임상적으로 타진성 근긴장증을 보이고 전기생리적 검사로 새끼손가락 외향근에서의 운동과 반복신경자극에서 복합근육활동전위의 감소를 보였으며, 이두박근의 근생검 소견상 용적이 증가된 근섬유와 중심핵화현상이 관찰되었다. 환자는 mexiletin 경구 투여후 근육의 강직현상이 다소 호전되었다. 이에 문헌고찰과 함께 Becker형 선천성 근긴장증 1례를 보고하는 바이다.

• Toxicological Research
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• 제34권3호
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• pp.199-210
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• 2018

Skeletal muscle can be ultrastructurally damaged by eccentric exercise, and the damage causes metabolic disruption in muscle. This study aimed to determine changes in the metabolomic patterns in urine and metabolomic markers in muscle damage after eccentric exercise. Five men and 6 women aged 19~23 years performed 30 min of the bench step exercise at 70 steps per min at a determined step height of 110% of the lower leg length, and stepping frequency at 15 cycles per min. $^1H$ NMR spectral analysis was performed in urine collected from all participants before and after eccentric exercise-induced muscle damage conventionally determined using a visual analogue scale (VAS) and maximal voluntary contraction (MVC). Urinary metabolic profiles were built by multivariate analysis of principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA) using SIMCA-P. From the OPLS-DA, men and women were separated 2 hr after the eccentric exercise and the separated patterns were maintained or clarified until 96 hr after the eccentric exercise. Subsequently, urinary metabolic profiles showed distinct trajectory patterns between men and women. Finally, we found increased urinary metabolites (men: alanine, asparagine, citrate, creatine phosphate, ethanol, formate, glucose, glycine, histidine, and lactate; women: adenine) after the eccentric exercise. These results could contribute to understanding metabolic responses following eccentric exercise-induced muscle damage in humans.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2696-2698
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• 2002

In this study, the comparison of the contractile states change at prime mover muscle with that at synergist muscle was executed, while the muscle contracted continuously with isometric contraction. The contractile states of muscle becomes to change when the voluntary contraction of skeletal muscle is progressed continuously. Such the contractile states change is divided into three states in consideration for not only physiological change but also the psychological change by CNS(central nervous system) as "stable state", "fatigue state" and "pain state". As a result of this study, the prime mover muscle is reached "pain state" but the synergist muscle is not reached. Namely the synergist muscle is delayed state than the prime mover muscle. This result judged that although the prime mover muscle have reached a limit when contraction is continued, owing to effect of delayed state of the synergist muscle, the prime mover muscle is endured some more contraction.

• Asian-Australasian Journal of Animal Sciences
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• 제28권11호
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• pp.1649-1656
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• 2015

Gene expression profiling has offered new insights into postmortem molecular changes associated with meat quality. To acquire reliable transcript quantification, high quality RNA is required. The objective of this study was to analyze integrity of RNA isolated from chicken skeletal muscle (pectoralis major) and its capability of serving as the template in quantitative real-time polymerase chain reaction (qPCR) as a function of postmortem intervals representing the end-points of evisceration, carcass chilling and aging stages in chicken abattoirs. Chicken breast muscle was dissected from the carcasses (n = 6) immediately after evisceration, and one-third of each sample was instantly snap-frozen and labeled as 20 min postmortem. The remaining muscle was stored on ice until the next rounds of sample collection (1.5 h and 6 h postmortem). The delayed postmortem duration did not significantly affect $A_{260}/A_{280}$ and $A_{260}/A_{230}$ ($p{\geq}0.05$), suggesting no altered purity of total RNA. Apart from a slight decrease in the 28s:18s ribosomal RNA ratio in 1.5 h samples (p<0.05), the value was not statistically different between 20 min and 6 h samples ($p{\geq}0.05$), indicating intact total RNA up to 6 h. Abundance of reference genes encoding beta-actin (ACTB), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), hypoxanthine-guanine phosphoribosyltransferase (HPRT), peptidylprolylisomerase A (PPIA) and TATA box-binding protein (TBP) as well as meat-quality associated genes (insulin-like growth factor 1 (IGF1), pyruvate dehydrogenase kinase isozyme 4 (PDK4), and peroxisome proliferator-activated receptor delta (PPARD) were investigated using qPCR. Transcript abundances of ACTB, GAPDH, HPRT, and PPIA were significantly different among all postmortem time points (p<0.05). Transcript levels of PDK4 and PPARD were significantly reduced in the 6 h samples (p<0.05). The findings suggest an adverse effect of a prolonged postmortem duration on reliability of transcript quantification in chicken skeletal muscle. For the best RNA quality, chicken skeletal muscle should be immediately collected after evisceration or within 20 min postmortem, and rapidly preserved by deep freezing.