• Journal of the Korean Society of Physical Medicine
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• v.18 no.3
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• pp.21-30
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• 2023

PURPOSE: The present study evaluated the occurrence, somatometric, biochemical, and behavioral characteristics of young Korean sarcopenic males aged between 30 to 39 years. METHODS: The study involved a total of 1,546 participants. These individuals were divided into two distinct groups based on their skeletal muscle mass index. Of these, 49 participants were categorized into the sarcopenia group, while the remaining 1,497 individuals were placed in the normal group. The researchers analyzed the occurrence of sarcopenia, somatometric, biochemical, and behavioral characteristics such as height, weight, body mass index (BMI), waist circumference (WC), skeletal muscle mass index, fasting glucose (FG), triglyceride and total cholesterol (TC) levels, systolic (SBP) and diastolic blood pressure (DBP), and the drinking and smoking status. A complex sampling data analysis was performed. RESULTS: The weighted occurrence of sarcopenia was found to be 3.24%, (95% confidence interval (CI) of 2.39% to 4.36%). The somatometric contributing factors were height, BMI, and WC (p < .05). Triglyceride and TC levels exhibited statistically significant differences in the biochemical variables (p < .05). The behavioral characteristics, including the drinking and smoking status, had no statistical significance (p > .05). CONCLUSION: This study identified specific occurrences of sarcopenia and contributing factors in young Korean men.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.2
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• pp.23-31
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• 2023

PURPOSE: This study examined the anthropometric and clinical risk factors and the prevalence of sarcopenia in women aged 40 to 49 years. METHODS: The study design is a cross-sectional research and a total of 2,055 participants were included. The participants were divided into two groups based on their skeletal muscle mass index score. One hundred and twenty-six individuals were assigned to a sarcopenia group, and 1,939 were assigned to a normal group. The following variables were analyzed: age, height, weight, body mass index, waist circumference, skeletal muscle mass index anthropometric measure, systolic blood pressure, diastolic blood pressure, blood laboratory tests, fasting glucose, triglyceride, total cholesterol, and smoking and drinking smoking statuses. RESULTS: The prevalence of sarcopenia was 6.5% (95% CI: 5.33-7.92). Anthropometric variables, such as height, BMI, and waist circumference, showed significance differences between the two groups (p < .05), except for weight variable (p > .05). In terms of blood pressure and blood lab tests, the systolic blood pressure, diastolic blood pressure, fasting glucose, triglyceride, and total cholesterol were all significant risk factors for sarcopenia in the two groups. (p < .05). CONCLUSION: This study identified risk factors and the prevalence of sarcopenia among community-dwelling middle-aged women.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.4
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• pp.19-27
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• 2023

PURPOSE: This investigation in the study aimed to assess to determine proportion and susceptibility makers of sarcopenia in Korean younger female aged 30 to 39 years. METHODS: To address the complex sampling design of Korea National Health and Nutrition Examination Surveys, appropriate individual weights were incorporated into the analysis. The data employed a stratified, clustered, multistage probability sampling design. A total of 2,098 participants were enrolled and categorized into two groups based on their skeletal muscle mass index scores. One hundred and twenty-four individuals were placed in the sarcopenia group, while 2,024 were allocated to a normal group. The study examined various markers as variables, including age, height, weight, body mass index waist circumference, skeletal muscle mass index, systolic and diastolic blood pressure, fasting glucose, triglyceride, and total cholesterol levels, and smoking and drinking habits. RESULTS: The study found that proportion of sarcopenia in this population was 3.78% (CI: 2.89-4.94) in sarcopenia group and 96.22% (CI: 95.06-97.11) in normal with weighed values. Several susceptibilities including height, weight, BMI, waist circumference, diastolic blood pressure, and total cholesterol levels were risk factor for sarcopenia (p < .05), exhibited significant differences between the sarcopenia and normal groups. CONCLUSION: This investigation provides the proportion of sarcopenia and identifies relevant susceptibility markers among community dwelling younger women in Korea.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.4
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• pp.57-66
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• 2023

PURPOSE: This research investigated clinical hazardous components and analyzed the proportion of sarcopenia among young Korean women. METHODS: The cross-sectional study included 1,236 women aged 20 to 29 years, categorized into two groups according to their skeletal muscle mass index (SMI). Of these, 20 participants were placed in the sarcopenia group, while 1,216 were included in the normal group. The analysis involved hazardous components including body dimensions, clinical indicators, and behavioral trait variables: height, weight, body mass index, waist circumference, skeletal muscle mass index, systolic and diastolic blood pressure, blood laboratory tests assessing fasting glucose, triglycerides, total cholesterol, as well as smoking habits and alcohol consumption. Complex sampling analysis was used to analyze the proportion and hazardous components of sarcopenia. RESULTS: The proportion of sarcopenia was at 1.76% (95% of CI: 1.08-2.83). Anthropometric measurements, such as height, BMI, and WC, exhibited significant differences between the groups (p < .05). However, there was no significant difference in weight (p > .05) between the two groups. Among the clinical indicators, SBP, DBP, FBG, serum triglycerides, and total TC found to be significant hazardous components for sarcopenia within both groups (p < .05). Smoking status as a behavioral trait was significant as well (p < .05), unlike alcohol consumption (p > .05). CONCLUSION: This study discerned both the proportion of sarcopenia and the hazardous components associated with it among community-dwelling women of a young age.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.7
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• pp.785-790
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• 2011

The goal of this study is to estimate the force acting on the knee joint in the human body by using the Hilltype muscle model based on a musculoskeletal model of the human lower extremity in the sagittal plane. For estimating the force applied, the human leg is modeled using multi-body modeling. This leg model comprises biarticular muscles acting on two joints of the upper and lower limbs, and the muscles include some of the major muscles such as the hamstring. In order to analyze the uncertainty of the applied forces acting on the knee joint, statistical distributions of human body, leg part, parameters are required and to obtain the parameter's statistical characteristic of the part sample survey method is employed. Finally, by using the sensitivity information of the parameters, the force acting on the knee joint can be estimated.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.686-690
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• 2015

The adrenergic receptor beta 2 (ADRB2) plays a role in various physiological responses of the muscle to exercise, such as contraction and relaxation. Given its important role in muscle function, we investigated the structure of the horse ADRB2 gene and its expression pattern after exercise to determine if it can serve as a putative biomarker for recovery. Evolutionary analyses using synonymous and non-synonymous mutation ratios, were compared with other species (human, chimpanzee, mouse, rat, cow, pig, chicken, dog, and cat), and revealed the occurrence of positive selection in the horse ADRB2 gene. In addition, expression analyses by quantitative polymerase chain reaction exhibited ubiquitous distribution of horse ADRB2 in various tissues including lung, skeletal muscle, kidney, thyroid, appendix, colon, spinal cord and heart, with the highest expression observed in the lung. The expression of ADRB2 in skeletal muscle was significantly up-regulated about four folds 30 minutes post-exercise compared to pre-exercise. The expression level of ADRB2 in leukocytes, which could be collected with convenience compared with other tissues in horse, increased until 60 min after exercise but decreased afterward until 120 min, suggesting the ADRB2 expression levels in leukocytes could be a useful biomarker to check the early recovery status of horse after exercise. In conclusion, we identified horse ADRB2 gene and analyzed expression profiles in various tissues. Additionally, analysis of ADBR2 gene expression in leukocytes could be a useful biomarker useful for evaluation of early recovery status after exercise in racing horses.

• Nutritional Sciences
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• v.7 no.1
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• pp.23-30
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• 2004

As a central component of a novel protein kinase cascade, the activation of the mitogen-activated protein (MAP) kinase cascade has attracted considerable attention. We sought to determine the effect of exercise and diet on the activation of the extracellular-signal regulated protein kinase (ERK) 1/2 and the p38 MAP kinase pathways in rat soleus muscle. Forty-eight Sprague-Dawley rats were assigned to one of two dietary conditions: high-carbohydrate (CHO) or high-fat (FAT). Animals having each dietary condition were further divided into one of three subgroups: a sedentary control group that did not exercise (NT), a group that performed 8 weeks of treadmill running and was sacrificed 48 h after their final treadmill run (CE), and a group that was sacrificed immediately after their final routine exercise training (AE). A high-fat diet did not have any significant effect on phosphorylated and total forms of ERK 1/2 or p38 MAP kinase. In chronically trained muscle that was taken 48 h after the last training, phosphorylated ERK 1/2 significantly increased only in the FAT but not in the CHO groups. In the case of total ERK 1/2, it increased significantly for both groups. In contrast, both phosphorylated and total forms of p38 MAP kinase decreased markedly compared to sedentary muscle. In muscle that was taken immediately after a last bout of exercise, phosphorylated ERK 1/2 increased in both groups but statistical significance was seen only in the CHO group. Total ERK 1/2 in acutely stimulated muscle increased only in the CHO-AE group even though the degree was much lower than the phosphorylated status. Muscle that was taken immediately after the routine training increased in phosphorylation status of p38 MAP kinase for both dietary conditions. However, statistical significance was seen only in the CHO group owing to a large variation with FAT. In conclusion, a high-fat diet per se did not have any notable effect versus a high-carbohydrate diet on MAP kinase pathways. However, when diet (either CHO or FAT) was combined with exercise and/or training, there was differentiated protein expression in MAP kinase pathways. This indicates MAP kinase pathways have diverse control mechanisms in slow-twitch fibers.

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.371-377
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• 2017

Muscle atrophy is characterized by a decrease in the mass of the muscle. With an increase in life expectancy and chronic illnesses, the incidence of muscle atrophy is increasing and the quality of life of patients is decreasing. Thus, reducing muscle atrophy is of high clinical and socio-economic importance. Mistletoe is a semi-parasitic plant that has been used as a traditional medicine in many countries to treat various human illnesses. It has been reported that Korean mistletoe extract (KME) has diverse biological functions including anti-tumor, anti-oxidant, anti-diabetic, anti-obesity properties, and extension of lifespan. Especially, we have recently reported that KME improves exercise endurance in mice, indicating its beneficial roles in enhancing the capacity of skeletal muscle. In this study, we investigated whether KME could activate the signaling pathway related to protein synthesis in a mouse model of muscle atrophy. Interestingly, KME efficiently activated the Akt/mTOR pathway, and Akt and mTOR are important signaling hub molecules for the acceleration of protein synthesis in muscle cells. In addition, KME also increased the activity of S6 kinase which is involved in the regulation of muscle cell size. Moreover, the ERK activity, required for transcription of ribosomal RNA for protein synthesis, was also enhanced in KME-treated mouse muscle. These data support the idea that KME increases muscle mass via increased protein synthesis. Our findings also suggest that Korean mistletoe might be a promising candidate for the development of functional foods that are beneficial for preventing muscle atrophy.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.6
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• pp.539-547
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• 2019

Anoctamin 5 (ANO5)/TMEM16E belongs to a member of the ANO/TMEM16 family member of anion channels. However, it is a matter of debate whether ANO5 functions as a genuine plasma membrane chloride channel. It has been recognized that mutations in the ANO5 gene cause many skeletal muscle diseases such as limb girdle muscular dystrophy type 2L (LGMD2L) and Miyoshi muscular dystrophy type 3 (MMD3) in human. However, the molecular mechanisms of the skeletal myopathies caused by ANO5 defects are poorly understood. To understand the role of ANO5 in skeletal muscle development and function, we silenced the ANO5 gene in C2C12 myoblasts and evaluated whether it impairs myogenesis and myotube function. ANO5 knockdown (ANO5-KD) by shRNA resulted in clustered or aggregated nuclei at the body of myotubes without affecting differentiation or myotube formation. Nuclear positioning defect of ANO5-KD myotubes was accompanied with reduced expression of Kif5b protein, a kinesin-related motor protein that controls nuclear transport during myogenesis. ANO5-KD impaired depolarization-induced $[Ca2^{+}]_i$ transient and reduced sarcoplasmic reticulum (SR) $Ca^{2+}$ storage. ANO5-KD resulted in reduced protein expression of the dihydropyridine receptor (DHPR) and SR $Ca^{2+}-ATPase$ subtype 1. In addition, ANO5-KD compromised co-localization between DHPR and ryanodine receptor subtype 1. It is concluded that ANO5-KD causes nuclear positioning defect by reduction of Kif5b expression, and compromises $Ca^{2+}$ signaling by downregulating the expression of DHPR and SERCA proteins.

• Biomedical Science Letters
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• v.13 no.4
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• pp.263-272
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• 2007

Nebulin is a giant actin binding protein (600-900 kDa) which is specific to skeletal muscle. This protein is known to regulate thin filaments length in sarcomere as a molecular template. The C-terminus of nebulin is located in the Z-disc of muscle sarcomere and is bound to other proteins such like myopalladin, titin, archvillin, and desmin. The N-terminus of nebulin binds to tropomodulin at the pointed ends of the thin filaments. In recent research, nebulin not only found in brain but also expressed in heart, stomach, and liver. So, the roles of nebulin in non-muscle tissue have been studied. However, lack of information or studies on nebulin binding proteins and nebulin function in brain are available so far. Therefore, the current study have investigated a novel binding partner of Nebulin C-terminus by using yeast two-hybrid screening with human brain cDNA library. Nebulin C-terminus, containing simple repeats, serine rich and SH3 domain, interacts with osteonectin C-terminal region. The specific interaction of nebulin and osteonectin were confirmed in vitro by using GST pull-down assay and reconfirmed in vivo by using transfected COS-7 cells with EGFP-tagged nebulin and DsRed-tagged osteonectin. Consequently, this study identified SH3 domain in nebulin C-terminus specifically binds to extracellular Ca-binding (EeC domain in osteonectin. Also, nebulin C-terminus fusion protein colocalized with osteonectin EC domain fusion protein in transfected COS-7 cells. The current study found the interaction between nebulin and osteonectin in human brain for the first time and suggested the nebulin in brain may be associated with osteonectin, as a regulator of cell cycle progression and mitosis.