• Asian-Australasian Journal of Animal Sciences
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• v.33 no.5
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• pp.704-711
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• 2020

Objective: Muscle fiber types, numbers and area are crucial aspects associated with meat production and quality. However, there are few studies of pig muscle fibre traits in terms of the detection power, false discovery rate and confidence interval precision of whole-genome quantitative trait loci (QTL). We had previously performed genome scanning for muscle fibre traits using 183 microsatellites and detected 8 significant QTLs in a White Duroc×Erhualian F₂ population. The confidence intervals of these QTLs ranged between 11 and 127 centimorgan (cM), which contained hundreds of genes and hampered the identification of QTLs. A whole-genome sequence imputation of the population was used for fine mapping in this study. Methods: A whole-genome sequences association study was performed in the F₂ population. Genotyping was performed for 1,020 individuals (19 F₀, 68 F₁, and 933 F₂). The whole-genome variants were imputed and 21,624,800 single nucleotide polymorphisms (SNPs) were identified and examined for associations to 11 longissimus dorsi muscle fiber traits. Results: A total of 3,201 significant SNPs comprising 7 novel QTLs showing associations with the relative area of fiber type I (I_RA), the fiber number per square centimeter (FN) and the total fiber number (TFN). Moreover, one QTL on pig chromosome 14 was found to affect both FN and TFN. Furthermore, four plausible candidate genes associated with FN (kinase non-catalytic C-lobe domain containing [KNDC1]), TFN (KNDC1), and I_RA (solute carrier family 36 member 4, contactin associated protein like 5, and glutamate metabotropic receptor 8) were identified. Conclusion: An efficient and powerful imputation-based association approach was utilized to identify genes potentially associated with muscle fiber traits. These identified genes and SNPs could be explored to improve meat production and quality via marker-assisted selection in pigs.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1635-1638
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• 1997

A measurement of conduction veloctiy of the action potentials along the muscle fibres has been applied to various diagnosis. When we measure muscle fiber conduction velocity, it occurs that not only change of conduction velocity but alos inclusion of mipulse component by physiological and experimental reason. So, robuster time delay estimation algorithm than general methods[1] is needed to find correct time delay form these signals. In this paper we, propose new time delay estimation algorithms, robust in impulsive noise, by using characteristic of .alpha.-stable distribution whcih defines impulsive noise well. Then we apply proposed algorthms to measure muscle fiber conduction velocity and compare them with other studies.

• Polymer(Korea)
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• v.26 no.4
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• pp.468-476
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• 2002

Oxy-PAN fiber prepared from the preoxidation and saponification of raw PAN fiber is known to elongate and contract when immersed in basic and acidic solutions, respectively. In this study, about 30% elongation in NaOH solution and 30∼50% contraction in HCl solution have been observed. In mechanical test, the mechanical properties of oxy-PAN fiber in the contracted state was stronger than that in the elongated state. These behaviors and mechanical properties are compared to those of living muscle and linear actuator. The change of length in NaOH and HCl solutions is due to switching between a hydrophilic and a hydrophobic structure. Other reasons are exchange of ion and water in/out of oxy-PAN fiber, and osmotic pressure difference associated with relevant ions. Much studies are needed to clarify the effective factors on but the oxy-PAN fiber's elongation/contraction behavior and mechanical properties, but the oxy-PAN fiber perpared in our laboratory has a sufficient potential for application as artificial muscle and linear actuator.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.301-308
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• 2018

Objective: This study compared the meat quality, muscle fiber characteristics, and fatty acids between Jinjiang yellow cattle (JJ) and F1 Simmental${\times}$Jinjiang yellow cattle (SJ) which were offered the same diet. Methods: Six JJ and six SJ individuals were reared and fattened from 10 to 26 months of age. After feeding, the highrib (HR), ribeye (RB), and tenderloin (TL) samples were taken from the carcass for meat quality evaluations. Results: The results showed that growth performance of SJ was higher than that of JJ (higher live weight and average daily gain), and the hot carcass weight of SJ was higher than that of JJ (p<0.05). pH of JJ was higher than that of SJ in TL (p<0.05); the color of $a^{\ast}$ of SJ was higher than that of JJ in TL and RB (p<0.05); the cooking loss of SJ was significantly lower than that of JJ in TL and RB (p<0.05); the shear force value was significantly lower in SJ compared to JJ (p<0.05); the muscle fiber diameter was higher and the fiber density was lower in SJ compared to JJ in HR and TL (p<0.05); compared to SJ, the muscles of JJ had higher saturated fatty acid (SFA) composition; the sum of monounsaturated fatty acid and polyunsaturated fatty acid (PUFA) were lower in the muscle of JJ; the mRNA expressions of myosin heavy chain-I (MyHC-I) and MyHC-IIa were higher in SJ compared to JJ in muscle of HR and RB; the mRNA expressions of MyHC-IIx and MyHC-IIb were lower in SJ compared to JJ in HR and RB (p<0.05). Conclusion: Meat quality and fatty acid profile differed between SJ and JJ; the muscle of SJ had higher $a^{\ast}$ and SFA; SJ had lower cooking loss, shear force and PUFA compared to the muscle of JJ. In addition, the type and development characteristics of the muscle fiber had some difference between SJ and JJ; these might be factors which caused the differences in meat quality and fatty acid profile between SJ and JJ.

• Journal of Oral Medicine and Pain
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• v.13 no.1
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• pp.61-69
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• 1988

The study of the muscle fiver composition and the muscle fiver type conversion during unilateral edentulous condition was undertaken in the rostral superficial masseter muscle of the whiter rat. 16 4-week-old male white rats weighting approximately 130gm that crowns of left upper and lower molare were cut intentionally, were divided into 4 groups (one control group and 3 experimental groups). After experimental groups were sacrificed by etherization in 6 days($E_1$), 18 days($E_2$) and 36 days($E_3$) separately, samples of the rostral superficial masseter muscle were obtained bilaterally and the proportion of type I, type IIA, type IIB, and type IIC fibers was determined and counted according to their histochemical activity of myosin ATPase (at pH 9.4, pH 4.6, and pH 4.2)and PAD staining. The obtained results were as follows : 1. The rostral superficial masseter muscle of the white rat contained approximately 47.5% type I fiber and 52.5% type II fiber. 2. Type I/ Type II ratio of molar-present side was increased significantly in the group E2 (18 days group) 3. Type IIA fiber was increased at molar-present side and decreased at molar-absent side in experimental groups.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.171-178
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• 2014

Myogenesis is the formation process of multinucleated myofiber with a contractile capacity from muscle satellite cell (MSCs) during life. This process is tightly controlled by several transcription factors such as Pax3 and Pax7 (paired box protein 3 and 7), MEF2C (myocyte enhancer factor 2) and MRFs (myogenic regulatory factors) etc. On the contrary, myostatin (MSTN) is a transforming growth factor-${\beta}$ superfamily, which functions as a negative regulator of skeletal muscle development and growth. Carnosic acid (CA) is a major phenolic component in rosemary (Rosmarinus officinalis) and have been reported various biological activities such as anticancer, antioxidant, antimicrobial and therapeutic agents for amnesia, dementia, alzheimer's disease. This study was confirmed to effects of CA on muscle cell line and muscle tissue alteration of zebrafish by intramuscular injection or feeding methods. $10{\mu}M$ CA showed a non-cytotoxic on myoblast and a complete inhibition effect against myostatin activity on luciferase assay. In intramuscular injection experiment, the total protein and triglyceride amount of $10{\mu}M/kg$ of CA injected group increased by 11% and decreased by 13% compared to these of the no injected group. In histology analysis of muscle tissues by hematoxylin/eosin staining, the number of muscle fiber of $10{\mu}M/kg$ of CA injected group decreased by 29% and fiber area increased 40% compared to these of no injected group. In feeding experiment, the total protein and triglyceride amount no significance difference compared to these of the normal feeding group. In histology analysis, the number of muscle fiber of 1% CA fed group decreased by 35% and fiber area increased 56% compared to these of normal fed group. We identified that CA have an effect on hypertrophy of muscle fiber in adult zebrafish and the results of this study are considered as the basic data that can reveal the mechanisms of muscle formation via gene and protein level analysis.

• Journal of Korean Academy of Nursing
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• v.23 no.2
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• pp.207-223
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• 1993

Inpatients are mostly occupied in bed with restricted activity, nearly all patient populations are at risk for the occurrence of skeletal muscle atrophy due to decreased level of activity. Restriction of mobility is far greater in pediatric patients compared with adult patients since almost all the activities of daily living is performed by parents or caregivers. It could be assumed that pediatric patients are more vulnerable to skeletal muscle atrophy than adult patients, however, there have been no attempts to reduce the atrophy of developing muscle. Therefore it is important to determine the effect of exercise in developing muscle during decreased activity. The purpose of this study was to determine the effect of periodic weight support during hindlimb suspension on the mass and cross-sectional area of Type I and II fibers in developing soleus(Type I ) muscle. To examine the effectiveness of periodic weight support activity in maintaining mass and fiber size. the hindlimb of young female Wistar rats was suspended(HS) and half of these rats walked on a treadmill for 45min / day(15min every 4h) at 5m / min at a 15 grade(HS-WS). After 7days of hindlimb suspension, soleus wet weight was 28. 57% smaller and relative soleus weight was 28. 21% smaller in comparison with con-trol rats (p〈0.05) Soleus wet weight and relative soleus weight increased by 67.72% and 71.43% each with periodic weight support activity during hindlimb suspension (p〈0.01, p〈0.005), moreover soleus wet weight and relative soleus weight of the HS -WS rats were greater than those of the control group. No change was observed in fiber type percentage of the developing soleus muscle after 1 week of hindlimb suspension plus weight support activity. Type I and II fiber cross-sectional areas of the developing soleus muscle were 50.45% and 43.39% lower in the HS group than in the control group (p〈0.0001), type I and II fiber cross-sectional areas of the developing soleus were 24.49% and 29.93% greater in the HS - WS group than in the HS rats (p〈0.0001), whereas Type I and II fiber cross-sectional areas of HS - WS group were less than those of the control group, The results suggest that periodic weight support activity can ameliorate developing soleus muscle atrophy induced by hindlimb suspension, even in type II fibers that would not have been expected to be recruited by this type of neuromuscular demand. Clinical experimental study is needed to deter-mine the effect of periodic weight bearing exercise on developing atrophied leg muscle based on these results.

• Journal of Korean Academy of Nursing
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• v.39 no.5
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• pp.632-640
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• 2009

Purpose: The purpose of this study was to examine the effect of DHEA (Dehydroepiandrosterone) on muscle weight and Type I and II fiber cross-sectional area of affected and unaffected hindlimb muscles in rats with neuropathic pain induced by unilateral peripheral nerve injury. Methods: Neuropathic pain was induced by ligation and cutting of the left L5 spinal nerve. Adult male Sprague-Dawley rats were randomly assigned to one of two groups: The DHEA group (n=10) had DHEA injections daily for 14 days, and the Vehicle group (n=10) had vehicle injections daily for 14 days. Withdrawal threshold, body weight, food intake and activity were measured every day. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected from the both hindlimbs. Body weight, food intake, activity, muscle weight and Type I, II fiber cross-sectional area of the dissected muscles were measured. Results: The DHEA group showed significant increases (p<.05), as compared to the vehicle group for muscle weight of the unaffected plantaris, and in Type II fiber cross-sectional area of the gastrocnemius muscle. The DHEA group demonstrated a higher pain threshold than the vehicle group whereas total diet intake and activity score were not significantly different between the two groups. Conclusion: DHEA administration for 14 days attenuates unaffected plantaris and gastrocnemius muscle atrophy.

• Journal of Korean Biological Nursing Science
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• v.10 no.1
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• pp.88-95
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• 2008

Purpose: The purpose of this study was to examine the effect of neuropathic pain by peripheral nerve injury on mass and Type I and II fiber cross-sectional areas on hindlimb muscles of the neuropathic pain model rat. Method: Adult male Sprague-Dawley rats (body weight 200-220 g) were assigned to one of two groups: a neuropathic pain group (n=7) that had a ligation of the left L5 spinal nerve, a control group (n=5), a naive rat without any procedures. Withdrawal threshold, activity, body weight and food intake were measured daily. At 8 days after neuropathic pain, all rats were anesthetized and the soleus and plantaris muscles were dissected from the both hindlimbs. Body weight, food intake, muscle weight and Type I and II fiber cross-sectional area of the dissected muscles were determined. Result: The neuropathic pain group showed a significant decreases (p<.05) as compared with the control rats, in diet intake, body weight, muscle weight and Type II fiber cross-sectional area of the left (affected side) soleus and plantaris muscles, and the right (unaffected side) muscle weight of plantaris and Type II fiber cross-sectional area of the soleus muscle. Conclusion: The hindlimb muscle atrophy occurs in both affected and unaffected side due to neuropathic pain by the peripheral nerve injury. The hindlimb muscle atrophy of the affected side is more pronounced than that of the unaffected side.

• The Journal of Korean Physical Therapy
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• v.14 no.2
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• pp.145-152
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• 2002

This study was carried out of to determine effects of high voltage pulsed galvanic stimulation on the soleus. target muscle of the sciatic nerve, of white rat two condition. The coditions included normal, and denervated muscle. The histochemical, ultrastructural observations were made. The following results were obtains. 1. The histochemical observations found the inflammatory cells between muscle bundle and muscle fiber since 1-week control group. In addition, nucleus located in the muscle fiber was frequently observed. 2. The experimental group showed a similar phenomenom to the normal muscles in terms of glycogen granules in the 1-week group, where as fiber were not distinguishable in4-weeks group which indicated that the degenerative changes had occured. 3. The NADH-TR reaction showed that the red muscle slightly increased in the 2-weeks group, and the distinguished was impossible the red fiber 4. The ultrastructures of the muscles in both groups were severely bend, and a number of vacuoles were observed due to the destruction of mitochondria..