• Journal of Life Science
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• v.22 no.4
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• pp.447-455
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• 2012

Akt plays an important role in a variety of cellular physiologies such as growth, proliferation, and differentiation. In skeletal muscle, Akt has been implicated in regulating regeneration, hypertrophy, and atrophy. In this study, the role of Akt has been examined during skeletal muscle differentiation. Culturing C2C12 myoblasts under low serum (1% horse serum) and high density converted cell morphology from a round shape to an elongated and multi-nucleated shape. Morphological changes were initiated from day 2 of differentiation. In addition, the expression of both myogenin G and myogenin D was elevated from day 2 of differentiation. Skeletal muscle differentiation was abolished by silencing Akt1 or Akt2, but was significantly enhanced by the over-expression of either Akt1 or Akt2. The activation of Akt was observed from day 2 of differentiation and disappeared after day 7. The expression of kruppel-like factor 4 was observed from day 6 of differentiation. Moreover, this expression was blocked in cells silencing either Akt1 or Akt2. In addition, the promoter activity of kruppel-like factor 4 was significantly reduced in cells silencing Akt1 or Akt2. These results suggest that Akt regulates skeletal muscle differentiation through the regulation of kruppel-like factor 4 expression.

• Journal of Nutrition and Health
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• v.44 no.5
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• pp.355-365
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• 2011

This study investigated how dietary fat affects muscle atrophy and lipid metabolism in various muscles during hindlimb immobilization in rats. Twenty-four male Sprague?Dawley rats had their left hindlimb immobilized and were divided into four groups by dietary fat content and composition. The contralateral hindlimb (control) was compared with the immobilized limb in all dietary groups. Rats (n = 6/group) were fed a 4% corn oil diet (CO), 2.6% corn oil + 1.4% fish oil diet (FO), 30% corn oil diet (HCO), or a 30% beef tallow diet (HBT)after their hind limbs were immobilized for 10 days. Data were collected for the gastrocnemius, plantaris and soleus muscles. Muscle atrophy was induced significantly after 10 days of hindlimb immobilization, resulting in significantly decreased muscle mass and total muscle protein content. The protein levels of peroxisome proliferator activated receptor ${\delta}$ (PPAR${\delta}$) in the plantaris, gastrocnemius, and soleus increased following hindlimb immobilization irrespective of dietary fat intake. Interestingly, the PPAR${\delta}$ mRNA level in the plantaris decreased significantly in all groups and that in the FO group was lower than that in the other groups. The soleus PPAR${\delta}$ mRNA level decreased significantly following hindlimb immobilization in the FO group only. Muscle carnitine palmitoyl transferase 1 (mCPT1) mRNA level was not affected by hindlimb immobilization. However, the mCPT1 mRNA level in the FO group was significantly lower in the plantaris but higher in the soleus than that in the other groups. The pyruvate dehydrogenase kinase 4 (PDK4) mRNA level in the plantaris decreased significantly, whereas that in the soleus increased significantly following hindlimb immobilization. The plantaris, but not soleus, PDK4 mRNA level was significantly higher in the FO group than that in the CO group. The increased PPAR${\delta}$ protein level following hindlimb immobilization may have suppressed triglyceride accumulation in muscles and different types of dietary fat may have differentially affected muscle atrophy according to muscle type. Our results suggest that ${\omega}$-3 polyunsaturated fatty acids may suppress muscle atrophy and lipid accumulation by positively affecting the expression level and activity of PPAR${\delta}$ and PPAR${\delta}$-related enzymes, which are supposed to play an important role in muscle lipid metabolism.

• Clinics in Shoulder and Elbow
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• v.13 no.2
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• pp.237-243
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• 2010

Purpose: In arthroscopic rotator cuff repair, the crucial step is secure fixation of Anchor to bone. However, osteoporosis of the tuberosity is frequently encountered in old patients, and can cause insecure fixation of anchors. The Aim of our study was to introduce a technique for anchor hole augmentation with bone cement when fixation failure of an anchor occurs, and to investigate the outcome. Materials and methods: Among 223 rotator cuff repairs performed between 2005 and 2009, anchor hole augmentation with polymethylmethacrylate was performed in 15 cases (all females; mean age of 65 years: range 49~77). Bone cement was injected into the anchor hole in a thick fluid state and the procedure was repeated to make a pot-like cement mantle. The anchor was inserted into the cement mantle while the cement hardened. The outcome was investigated, on average, at 16 months (6~32). Results: Radiographs showed cystic changes of the tuberosity. On follow-up radiographs and MRI, a change in the cement mantle was not noted. The final average UCLA score was 31 (28~35); 6 had excellent, 8 good and 1 fair results (p=0.008). Age-sex matched Constants score was 90 (74~98) (p=0.008). Conclusion: Anchor hole augmentation with bone cement is useful when fixation failure of an anchor is encountered due to bone atrophy. Anchor hole augmentation with bone cement does not negatively influence the outcome.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.199-206
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• 2009

Purpose: Our goal for this study was to prospectively evaluate the functional & structural outcomes, by means of CT arthroscopy, of arthroscopic double-row fixation for treating rotator cuff tear. We also attempted to determine the variants that affect the functional & structural outcomes. Materials and Methods: Twenty seven consecutive patients underwent arthroscopic rotator cuff repair with double-row fixation. The average age at the time of the operation was fifty six years. The preoperative and postoperative examinations consisted of determining the Constant score, the score for the visual analogue scale for pain, the UCLA score, the American Shoulder and Elbow Surgeons (ASES) score, as well as a full physical examination of the shoulder. Preoperative MR arthrography was used to evaluate the integrity and atrophy of the rotator cuff. We measured the intraoperative tear size in the sagittal and coronal planes. Postoperative CT arthrography was used at one year postoperatively to evaluate the integrity and atrophy of the repaired tendons and muscles. Results: Preoperative MR arthrography revealed an average 29.22 mm tear size in the sagittal plane and an average 22.72 mm tear size in the coronal plane. Twelve cases of supraspinatus muscle atrophy and two cases of infraspinatus atrophy were observed on the preoperative MR arthrography. The average clinical outcome scores all significantly improved at the time of follow-up. At a mean of one year postoperatively, CT arthrography revealed 48.1% of the shoulders had healed, 11.1% showed incomplete healing and 40.7% showed retear of the repaired tendon. Conclusion: Arthroscopic double-row repair can result in improved clinical outcomes and good patient satisfaction. However, the problems about how to enhance healing of the repaired tendon still remain.

• Journal of Life Science
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• v.29 no.2
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• pp.215-222
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• 2019

Muscle dysfunction may arise from skeletal muscle atrophy caused by aging, injury, oxidative stress, and hereditary disease. Powdered heat-killed Enterococcus faecalis (EF-2001) has anti-allergy, anti-inflammatory, and anti-tumor effects. However, its antioxidant and anti-atrophy effects are poorly characterized. In this study, we examined the effects of EF-2001 on muscle atrophy. To determine the protective effect of EF-2001 on oxidative stress, C2C12 myoblasts were treated with $H_2O_2$ to induce oxidative stress. This induced cell damage, which was reduced by treatment with EF-2001. The mechanism of EF-2001's effect was examined in response to oxidative stress. Treatment with EF-2001 reversed the expression of HSP70 and SOD1 proteins. Also, mRNA levels of Atrogin-1/MAFbx and MuRF1 increased under oxidative stress conditions but decreased following EF-2001 treatment. To evaluate muscle volume, two and three dimensional models of the muscles were analyzed using micro-CT. As expected, muscle volume decreased after sciatic denervation and recovered after oral administration of EF-2001. Therefore, EF-2001 is a candidate for the treatment of muscular atrophy, and future discovery of the additional effects of EF-2001 may yield further applications as a functional food with useful activities in various fields.

• Journal of Korean Academy of Nursing
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• v.27 no.1
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• pp.96-108
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• 1997

The purpose of this study was to determine the effect of endurance training prior to occurrence of muscle atrophy on the mass, myofibrillar protein content and fiber crossectional area of atrophied hindlimb muscles of rats. Adult female Wistar rats were trained prior to occurrence of muscle atrophy induced by hindlimb suspension. Training began on the 1st day for 10min /day at 15m /min on a 0% grade, training exercise increased daily in time and intensity so that by the 4th week rats were running 60min /day, at 34m /min on a i3.5% grade. Wet weight and relative weight of soleus, plantaris and gastrocnemius muscle decreased significantly after seven days of hindlimb suspension. Wet weight and relative weight of soleus tended to increase and that of plantaris and gastrocnemius tended to decrease in the exercise group as compared to the control group. Myofibrillar protein content of soleus and gastrocnemius tended to increase and that of plantaris tended to decrease in the endurance trained group as compared to the control group. Fiber crossectional area of Type I, II fiber in soleus and plantaris muscle tended to increase in the exercise group as compared to the control group. Wet weight and relative weight of soleus. plantaris and gastrocnemius decreased significantly, myofibrillar protein content of soleus, plantaris and gastrocnemius increased in hindlimb suspended rats following endurance training as compared to the control group. There was no change in fiber type percentage and crossectional area of type I and II fiber in soleus muscle and that of type I and IIfiber in plantaris muscle decreased in the hindlimb suspended rats following endurance training as compared to the control group. Wet weight and relative weight of soleus and plantaris tended to increase, that of gastrocnemius increased significantly, myofibrillar protein content of soleus and plantaris muscle increased significantly and that of gastrocnemius tended to increase in the hindlimb suspended rats following endurance training as compared to sedentary rats following endurance training. Crossectional area of type I fiber of soleus muscle tended to increase. that of type I fiber of plantaris muscle increased significantly and that of type II fiber tended to increase in hindlimb suspended rats following endurance training as compared to sedentary rats following endurance training. The results suggest that endurance training prior to occurrence of muscle atrophy can attenuate the decrease of mass, myofibrillar protein content and fiber crossectional area induced by hindlimb suspension.

• Journal of Korean Academy of Nursing
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• v.39 no.3
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• pp.321-328
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• 2009

Purpose: The purpose of this study was to determine the effect of Dehydroepiandrosterone(DHEA) administration alone or exercise combined with DHEA before steroid treatment on rat hindlimb muscles. Methods: Male Sprague-Dawley rats were assigned to one of three groups: a steroid group(S, n=10) that had no treatment for 7 days before steroid treatment; a DHEA-steroid group(DS, n=8) that had 0.34 mmol/kg/day DHEA injection once a day for 7 days before steroid treatment and an exercise+DHEA-steroid group(EDS, n=9) that ran on the treadmill combined with 0.34 mmol/kg/day DHEA injection for 7 days before steroid treatment. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected. Body weight, food intake, muscle weight, myofibillar protein content and cross-sectional area of the dissected muscles were determined. Results: The DS group showed significant increases(p<.05) as compared to the steroid group in body weight, and muscle weight of gastrocnemius muscles. The EDS group showed significant increases(p<.05) as compared to the S group in body weight, muscle weight, myofibrillar protein content, and Type II fiber cross-sectional area of soleus, plantaris and gastrocnemius muscles. Conclusion: Exercise combined with DHEA administration before steroid treatment prevents steroid induced muscle atrophy, with exercise combined with DHEA administration being more effective than DHEA administration alone in preventing muscle atrophy.

• Journal of Korean Academy of Nursing
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• v.44 no.4
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• pp.371-380
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• 2014

Purpose: The purpose of this study was to examine the effects of Cu/Zn SOD on reduction of hindlimb muscular atrophy induced by cisplatin in rats. Methods: Forty-two rats were assigned to three groups; control group, Cisplatin (CDDP) group and cisplatin with Cu/Zn SOD (CDDP-SOD) group. At day 35 hindlimb muscles were dissected. Food intake, activity, withdrawal threshold, muscle weight, and Type I, II fiber cross-sectional area (CSA) of dissected muscles were measured. Relative SOD activity and expression of MHC and phosphorylated Akt, ERK were measured after dissection. Results: Muscle weight and Type I, II fiber CSA of hindlimb muscles in the CDDP group were significantly less than the control group. Muscle weight and Type I, II fiber CSA of hindlimb muscles, food intake, activity, and withdrawal thresholds of the CDDP-SOD group were significantly greater than the CDDP group. There were no significant differences in relative SOD activities of hindlimb muscles between the CDDP-SOD and CDDP groups. MHC expression and phosphorylated Akt, ERK of hindlimb muscles in the CDDP-SOD group were significantly greater than the CDDP group. Conclusion: Cu/Zn SOD attenuates hindlimb muscular atrophy induced by cisplatin through increased food intake and activity. Increment of phosphorylated Akt, ERK may relate to attenuation of hindlimb muscular atrophy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.819-828
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• 2011

Due to emergence of large discount mart and on-line shopping, and the resulting shrinkage of market share, traditional market that is typically having operational disadvantages is facing a predicament. However, considering the total sales volume and the consumer traffic, it is true that traditional market still plays an important role. In this context, traditional market should be vitalized through an improved management system as well as restructuring, and seek a balanced growth in the distribution industry. In order to provide competitiveness to the local traditional market of Jeung-Pyung Province and to vitalize the local economy, an analysis was preformed for the local market environment, and the vitalization plans, which can be referenced in determining the local economic policies, are suggested in this paper.

• The Journal of the Korean bone and joint tumor society
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• v.8 no.2
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• pp.39-42
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• 2002

We present a case of the patient with early detection of entrapment of inferior branch of the suprascapular nerve caused by multiple ganglion cysts at the spinoglenoid notch of the scapula, recovering from hypotrophy of the infraspinatus muscle and treating successfully after surgical removal of the cysts, and decompression of the nerve.