• Food Science of Animal Resources
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• v.38 no.6
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• pp.1305-1314
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• 2018

To investigate relationships of electronic taste-traits with muscle fiber type composition (FTC) and contents of nucleotides, porcine longissimus lumborum (LL), psoas major (PM), and infra spinam (IS) muscles were obtained from eight castrated LYD pigs. FTC and taste-traits in these three porcine muscles were measured by histochemical analysis and electronic tongue system, respectively. IS had significantly higher proportion of type I fibers while LL had significantly higher proportion of type IIB than other muscles (p<0.05). IS had the highest inosine monophosphate (IMP) content while LL had the lowest IMP content (p<0.05). In contrast, LL had significantly higher hypoxanthine content compared to PM and IS (both p<0.05). For taste-traits, IS had significantly higher umami and richness values but lower sourness value than LL and PM (p<0.05). Sourness and astringency values of LL were significantly higher than those of IS (p<0.05). The proportion of type IIB fiber was positively correlated with sourness and astringency but negatively correlated with saltiness. These results suggest that sourness and astringency tastes are increased with increasing proportions of type IIB fibers in porcine muscles due to increase of hypoxanthine content. These results also imply that umami and richness tastes are increased with increasing contents of type I and IIA fibers because of increased IMP content in porcine muscles.

• Journal of Korean Academy of Nursing
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• v.39 no.3
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• pp.393-400
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• 2009

Purpose: The purpose of this study was to examine the effects of unilateral sciatic nerve injury on unaffected hindlimb muscles of rats. Methods: Adult male Sprague-Dawley rats were assigned to one of three groups: control(C) group(n=10) that had no procedures, sham(S) group(n=10) that underwent sham left sciatic nerve transection, and sciatic nerve transection(SNT) group(n=9) that underwent left sciatic nerve transection. At 15 days rats were anesthetized, and the soleus, plantaris and gastrocnemius muscles were dissected. Results: Muscle weight of the unaffected plantaris muscle in the SNT group was significantly lower than in the other two groups. Type II fiber cross-sectional areas of the unaffected plantaris and gastrocnemius muscles in the SNT group were significantly smaller than in the other two groups. The decrease of muscle weights and Type I, II fiber cross-sectional areas of the unaffected three muscles in the SNT group were significantly less than that of the affected three muscles. Conclusion: Hindlimb muscle atrophy occurs in the unaffected side after unilateral sciatic nerve injury, with changes in the plantaris and gastrocnemius muscle being more apparent than changes in the soleus muscle. These results have implications for nursing care, in the need to assess degree of muscle atrophy in unaffected muscles as well as affected muscles.

• Herbal Formula Science
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• v.24 no.4
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• pp.311-321
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• 2016

Chronic or acute alcohol abuse often leads to liver injury associated with alcoholic hepatitis, liver fibrosis, cirrhosis, and liver cancer. In addition to the liver, alcohol abuse also induces a variety of other tissue injuries including pancreatitis, cardiomyopathy, neurotoxicity and muscle loss. Chronic skeletal muscle myopathy, independent of peripheral neuropathy, is well recognised in alcoholic patients. Several mechanisms may be involved in the pathogenesis of alcoholic myopathy. Ethanol is a potent inhibitor of muscle protein synthesis. Gastrocnemius and plantaris muscles are Type II fiber-predominant and usually considered representative of the musculature as a whole. Whereas, soleus muscle is Type I fiber predominant. Shihosogan-san is a traditional Korean medicine that is widely employed to treat indigestion and liver diseases. Muscle diseases are often related to liver diseases and conditions. We therefore tested the hypothesis that treatment with Shihosogan-san could ameliorate the ethanol-induced changes in muscle protein synthesis. Young male Sprague-Dawley rats were orally given 25% ethanol (5ml/kg, body weight) daily with Ethanol for 28 days. Normal group was similarly administrated with saline. In Shihosogan-san treated group, rats were orally administrated Shihosogan-san extract, and rats of EtOH group were given with the vehicle only. After 4 week, the morphology of gastrocnemius and plantaris muscles were assessed by hematoxylin and eosin staining. For comparative purposes, liver function was also investigated. The muscles from rats of EtOH group displayed a significant reduction in average cross section area compared to Normal group. Shihosogan-san treated group had increased fiber compared to the EtOH group. Moreover, Shihosogan-san treated group compared with EtOH group showed significantly decreased pro-apoptotic BAX expression and increased anti-apoptotic Bcl-2 expression. In conclusion, Shihosogan-san extract showed ameliorating effects on chronic alcohol toxicity in skeletal muscle.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.710-722
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• 2024

Extracellular matrix (ECM) proteins play a crucial role in culturing muscle stem cells (MuSCs). However, there is a lack of extensive research on how each of these proteins influences proliferation and differentiation of MuSCs from livestock animals. Therefore, we investigated the effects of various ECM coatings-collagen, fibronectin, gelatin, and laminin-on the proliferation, differentiation, and maturation of porcine MuSCs. Porcine MuSCs, isolated from 14-day-old Berkshire piglets, were cultured on ECM-coated plates, undergoing three days of proliferation followed by three days of differentiation. MuSCs on laminin showed higher proliferation rate than others (p<0.05). There was no significant difference in the mRNA expression levels of PAX7, MYF5, and MYOD among MuSCs on laminin, collagen, and fibronectin (p>0.05). During the differentiation period, MuSCs cultured on laminin exhibited a significantly higher differentiation rate, resulting in thicker myotubes compared to those on other ECMs (p<0.05). Also, MuSCs on laminin showed higher expression of mRNA related with maturated muscle fiber such as MYH1 and MYH4 corresponding to muscle fiber type IIx and muscle fiber type IIb, respectively, compared with MuSCs on other ECM coatings (p<0.05). In summary, our comparison of ECMs revealed that laminin significantly enhances MuSC proliferation and differentiation, outperforming other ECMs. Specifically, muscle fibers cultured on laminin exhibited a more mature phenotype. These findings underscore laminin's potential to advance in vitro muscle research and cultured meat production, highlighting its role in supporting rapid cell proliferation, higher differentiation rates, and the development of mature muscle fibers.

• Animal Bioscience
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• v.35 no.6
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• pp.847-857
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• 2022

Objective: The effects of maternal undernutrition during midgestation on muscle fiber histology, myosin heavy chain (MyHC) expression, methylation modification of myogenic factors, and the mammalian target of rapamycin (mTOR) signaling pathway in the skeletal muscles of prenatal and postnatal goats were examined. Methods: Twenty-four pregnant goats were assigned to a control (100% of the nutrients requirement, n = 12) or a restricted group (60% of the nutrients requirement, n = 12) between 45 and 100 days of gestation. Descendants were harvested at day 100 of gestation and at day 90 after birth to collect the femoris muscle tissue. Results: Maternal undernutrition increased (p<0.05) the fiber area of the vastus muscle in the fetuses and enhanced (p<0.01) the proportions of MyHCI and MyHCIIA fibers in offspring, while the proportion of MyHCIIX fibers was decreased (p<0.01). DNA methylation at the +530 cytosine-guanine dinucleotide (CpG) site of the myogenic factor 5 (MYF5) promoter in restricted fetuses was increased (p<0.05), but the methylation of the MYF5 gene at the +274,280 CpG site and of the myogenic differentiation (MYOD) gene at the +252 CpG site in restricted kids was reduced (p<0.05). mTOR protein signals were down-regulated (p<0.05) in the restricted offspring. Conclusion: Maternal undernutrition altered the muscle fiber type in offspring, but its relationship with methylation in the promoter regions of myogenic genes needs to be elucidated.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.352-355
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• 1998

A musculotendon model is investigated to show muscle fatigue under the repeated functional electrical stimulation (FES). The normalized Hill-type model can predict the decline in muscle force. It consists of nonlinear activation and contraction dynamics including physiological concepts of muscle fatigue. A muscle fatigue as a function of the intracellular acidification, pHi is inserted into contraction dynamics to estimate the force decline. The computer simulation shows that muscle force declines in stimulation time and the change in the estimate of the optimal fiber length has an effect only on muscle time constant not on the steady-state tetanic force.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.639-644
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• 2005

The aim of this study was to investigate the effect of the myosin light chain (MLC) isoforms on the muscle fiber characteristics and meat quality traits in porcine longissimus muscle. Pale, soft, exudative (PSE) samples had a lower content of essential light chain (ELC) 1S isoforms and a higher proportion of the fiber type IIB than the reddish-pink, firm, non-exudative (RFN) samples. These compositions suggest that the PSE pork has a higher glycolytic and a lower oxidative capacity than the RFN pork. Therefore, these characteristics of PSE pork might affect the metabolic rate and meat quality traits, including protein solubility. In addition, the indicator traits of the postmortem metabolic rate were related to the ELC 1F/3F ratio ($pH_{45\;min}$: r = -0.43, P < 0.001; R-value: r = 0.53, P < 0.001). These results suggest that the MLC isoform composition can affect the postmortem metabolic rate and meat quality traits.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.12
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• pp.20-28
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• 2007

• Food Science of Animal Resources
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• v.38 no.4
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• pp.711-717
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• 2018

Myogenic factor 5 (MYF5) plays an important role in regulating skeletal muscle fiber characteristics, consequently affecting meat production and quality. We identified a novel p.A41P mutation in exon1 of the porcine MYF5 gene by direct sequencing. The mutation was predicted to be destabilizing in protein structure based on the resultant amino acid substitution. We estimated the significant substitution effect of p.A41P on the energy stabilization of Myf5 protein structure. Then, we demonstrated that the mutation in Yorkshire population significantly affected muscle fiber type I composition (p<0.05), loin-eye area of lean meat content (p<0.05) and filter-fluid uptake of meat quality (p<0.01). Furthermore, dominant effects significantly influenced total muscle fiber number (p<0.05). This study suggests that the novel p.A41P mutation in porcine MYF5 may be a valuable genetic marker to affect the muscle fiber characteristics and consequently improve meat production quality and quantity.

• Korean Journal of Cleft Lip And Palate
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• v.12 no.2
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• pp.47-56
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• 2009

The orbicularis oris muscle (OOM) is a very important muscle that originate from the second branchial arch and is innervated by the facial nerve. The aim of this study was to elucidate distribution types of two muscle fibers that composing OOM by using enzyme-histochemical examinations and tried to make a basis for a clinical application. The fresh frozen tissues from the superior and inferior portions of the OOM were taken from post mortem 65-year-old Korean male adult. Total five different sagittal sections were used on the midline of the philtrum, the middle portion of lower lip, the mouth corner, and each midlateral side of upper and lower mouth. We used enzyme-histochemical staining such as Periodic Acid-Schiff (PAS), Succinic Dehydrogenase (SDHase), reduced Nicotinamide Adenine Dinucleotide-Tetrazolium Reductase (NADH-TR), Adenosine Triphosphatase (ATPase) in pH 9.4, 4.6 and 4.3, and Modified Gomori Trichrome. There were about 30.24 % type 1 muscle fiber and 65.40 % type 2 muscle fiber in the midline of the philtrum (p < 0.05). Enzyme-histochemical staining is very useful and innovative method to elucidate characteristics of muscle fibers. We expect that chiloplasty and reconstruction of the lip portions for cleft lip patients, based on these results, are better to recovery function and aesthetic. However, we have some problems as an intramuscular variability and the inter-individual variation etc. Therefore we have to make progress these studies continuously to overcome these problems.