• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1762-1772
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• 2013

The objective of the current study was to determine the effect of pre-slaughter stress, season and breed on the activity of plasma creatine kinase (CK) and the quality of mutton. One hundred and seventy-three (173) castrated sheep from Dormer (DM), South African Mutton Merino (SAMM), Dorper (DP) and Blackhead Persian (BP) sheep breeds were used in the study. The animals were grouped according to age-groups as follows: Group 1 (6 to 8 months), Group 2 (9 to 12 months) and Group 3 (13 to 16 months). Blood samples were collected during exsanguinations using disposable vacutainer tubes for CK analysis. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL) were collected from 84 castrated sheep, of different breeds (28 per breed) 24 h after slaughter. The following physico-chemical characteristics of mutton were determined; meat pH ($pH_{24}$), color ($L^*$, $a^*$ and $b^*$), thawing and cooking losses and Warner Braztler Shear Force (WBSF). The activity of plasma CK was significantly higher (p<0.001) in summer ($1,026.3{\pm}105.06$) and lower in winter ($723.3{\pm}77.75$). There were higher values for $L^*$ ($33.7{\pm}0.94$), $b^*$ ($11.5{\pm}0.48$) and WBSF ($29.5{\pm}1.46$) in summer season than in winter season; $L^*$ ($29.4{\pm}0.64$), $b^*$ ($10.2{\pm}0.33$) and WBSF ($21.2{\pm}0.99$). The activity of plasma CK was influenced by the type of breed with Dormer having the highest (p>0.001) levels ($1,358.6{\pm}191.08$) of CK. South African Mutton Merino had higher values for $pH_{24}$ ($5.9{\pm}0.06$), $L^*$ ($34.2{\pm}0.97$), $b^*$ ($12.2{\pm}0.50$) and WBSF ($26.8{\pm}1.51$) and Blackhead Persian had higher values ($35.5{\pm}2.17$) for cooking loss (CL%) than the other breeds. Computed Principal Component Analyses (PCA) on the activity of plasma CK and physico-chemical characteristics of mutton revealed no correlations between these variables. However, positive correlations were observed between $pH_{24}$, $L^*$, $a^*$, $b^*$, CL% and WBSF. Relationships between pre-slaughter stress, CK activity and physico-chemical characteristics of mutton were also observed. It was therefore concluded that although mutton quality and creatine kinase were not related, pre-slaughter stress, season and breed affected the activity of creatine kinase and mutton quality.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.12
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• pp.959-966
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• 2013

In this study, based on P-3CK project using aging aircraft without any design information, the structural assessments of fastener holes to repair the short edge distance defects are investigated. For this purpose, the nacelle longeron which has many defects is selected and then conservative stress is calculated by performing the static analysis of 1.5ED, 1.8ED, 2.0ED defects of longeron fastener holes. This result applies to TWIST standard load spectrum to generate flight load spectrum. Then the crack growth analysis is performed by using flight load spectrum. Through this, the validity of a repaired fastener hole is evaluated. Finally, the standard of repair and the period of maintenance for a defected fastener hole are established.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.1-11
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• 2017

The purpose of the study is to develop an online measurement scale for diagnosing self-directed learning ability for students in Korea. In order to achieve the goal, literature review, case analyses, and experts interview were carried out and finalized the blended-learning based SMMIS model. A total of 1,626 elementary, middle and high school students participated in the scale survey to validate the credibility and validity. Based on these results, an online measurement tool for self-directed learning was developed. The tool can be used in blended-learning environment to maximize its effectiveness. In conclusion, we discussed about implications and strategies for the blended-learning based on self-directed learning program model for young students, and suggested future vision and further research.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.2
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• pp.127-132
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• 2013

Ginsenosides, one of the active ingredients of Panax ginseng, show various pharmacological and physiological effects, and they are converted into compound K (CK) or protopanaxatriol (M4) by intestinal microorganisms. CK is a metabolite derived from protopanaxadiol (PD) ginsenosides, whereas M4 is a metabolite derived from protopanaxatriol (PT) ginsenosides. The ${\gamma}$-aminobutyric acid $receptor_C$ ($GABA_C$) is primarily expressed in retinal bipolar cells and several regions of the brain. However, little is known of the effects of ginsenoside metabolites on $GABA_C$ receptor channel activity. In the present study, we examined the effects of CK and M4 on the activity of human recombinant $GABA_C$ receptor (${\rho}$ 1) channels expressed in Xenopus oocytes by using a 2-electrode voltage clamp technique. In oocytes expressing $GABA_C$ receptor cRNA, we found that CK or M4 alone had no effect in oocytes. However, co-application of either CK or M4 with GABA inhibited the GABA-induced inward peak current ($I_{GABA}$). Interestingly, pre-application of M4 inhibited $I_{GABA}$ more potently than CK in a dose- dependent and reversible manner. The half-inhibitory concentration ($IC_{50}$) values of CK and M4 were $52.1{\pm}2.3$ and $45.7{\pm}3.9{\mu}M$, respectively. Inhibition of $I_{GABA}$ by CK and M4 was voltage-independent and non-competitive. This study implies that ginsenoside metabolites may regulate $GABA_C$ receptor channel activity in the brain, including in the eyes.

• Journal of Ginseng Research
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• v.44 no.6
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• pp.799-807
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• 2020

Background: The skin acts as a barrier to protect organisms against harmful exogenous agents. Compound K (CK) is an active metabolite of ginsenoside Rb1, Rb2 and Rc, and researchers have focused on its skin protective efficacy. In this study, we hypothesized that increased expression of the serine protease inhibitor Kazal type-5 (SPINK5) may improve skin barrier function. Methods: We screened several ginsenosides to increase SPINK5 gene promoter activity using a transactivation assay and found that CK can increase SPINK5 expression. To investigate the protective effect of CK on the skin barrier, RT-PCR and Western blotting were performed to investigate the expression levels of SPINK5, kallikrein 5 (KLK5), KLK7 and PAR2 in UVB-irradiated HaCaT cells. Measurement of transepidermal water loss (TEWL) and histological changes associated with the skin barrier were performed in a UVB-irradiated mouse model and a 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis-like model. Results: CK treatment increased the expression of SPINK5 and decreased the expression of its downstream genes, such as KLKs and PAR2. In the UVB-irradiated mouse model and the DNCB-induced atopic dermatitis model, CK restored increased TEWL and decreased hydration and epidermal hyperplasia. In addition, CK normalized the reduced SPINK5 expression caused by UVB or DNCB, thereby restoring the expression of the proteins involved in desquamation to a level similar to normal. Conclusions: Our data showed that CK contributes to improving skin-barrier function in UVB-irradiated and DNCB-induced atopic dermatitis-like models through SPINK5. These results suggest that therapeutic attempts with CK might be useful in treating barrier-disrupted diseases.

• Journal of Microbiology
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• v.35 no.4
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• pp.284-289
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• 1997

A Gram (-), rod-shaped bacterium $2.3{\sim}2.8{\times}0.45{\mu}m$ in size which exhibited growth-inhibiting effects against a cyanobacterium (Anabaena cylindrica) was isolated from Daechung Dam Reservoir. This isolate was identified as Moraxella sp. and designated Moracella sp. CK-1. Hollow zones formed around bacterial colonies on the cyanobacterial lawn. In a mixed-culture of A. cylindrica and the isolate, each microorganism grew inverse-proportionally, and the cyanobacterial vegetative cells completely disappeared within 24 hours. On treatment with Moraxella sp. CK-1, cell walls of A. cylindrica disappeared, but sheathes remained in a more electron dense form. The unit membrane such as thylakoidal membrane was stable to bacterial lysing activity. This bacterium showed a broad action spectrum against cyanobacteria. The growth-inhibiting activity of Moracella sp. CK-1 against A. cylindrica is believed to be performed through the excretion of active substances.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.298-306
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• 2017

Background: Compound K (CK) is a bioactive derivative of ginsenoside Rb1 in Panax ginseng (Korean ginseng). Its biological and pharmacological activities have been studied in various disease conditions, although its immunomodulatory role in innate immunity mediated by monocytes/macrophages has been poorly understood. In this study, we aimed to elucidate the regulatory role of CK on cellular events mediated by monocytes and macrophages in innate immune responses. Methods: The immunomodulatory role of CK was explored by various immunoassays including cell-cell adhesion, fibronectin adhesion, cell migration, phagocytic uptake, costimulatory molecules, reactive oxygen species production, luciferase activity, and by the measurement of mRNA levels of proinflammatory genes. Results: Compound K induced cell cluster formation through cell-cell adhesion, cell migration, and phagocytic activity, but it suppressed cell-tissue interactions in U937 and RAW264.7 cells. Compound K also upregulated the surface expression of the cell adhesion molecule cluster of differentiation (CD) 43 (CD43) and costimulatory molecules CD69, CD80, and CD86, but it downregulated the expression of monocyte differentiation marker CD82 in RAW264.7 cells. Moreover, CK induced the release of reactive oxygen species and induced messenger RNA expression of proinflammatory genes, inducible nitric oxide synthase, and tumor necrosis factor-alpha by enhancing the nuclear translocation and transcriptional activities of nuclear factor kappa-B and activator protein-1. Conclusion: Our results suggest that CK has an immunomodulatory role in innate immune responses through regulating various cellular events mediated by monocytes and macrophages.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.295-298
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• 2008

Creatine kinase (CK; E.C. 2.7.3.2) is an important enzyme that catalyzes the reversible transfer of a phosphoryl group from ATP to creatine in energy homeostasis. The brain-type cytosolic isoform of creatine kinase (BB-CK), which is found mainly in the brain and retina, is a key enzyme in brain energy metabolism, because high-energy phosphates are transfered through the creatine kinase/phosphocreatine shuttle system. The recombinant human BB-CK protein was overexpressed as a soluble form in Escherichia coli and crystallized at $22^{\circ}C$ using PEG 4000 as a precipitant. Native X-ray diffraction data were collected to $2.2{\AA}$ resolution using synchrotron radiation. The crystals belonged to the tetragonal space group $P4_32_12$, with cell parameters of a=b=97.963, $c=164.312{\AA},\;and\;{\alpha}={\beta}={\gamma}=90^{\circ}$. The asymmetric unit contained two molecules of CK, giving a crystal volume per protein mass $(V_m)$ of $1.80{\AA}^3\;Da^{-1}$ and a solvent content of 31.6%.

• The Korean Journal of Food & Health Convergence
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• v.7 no.3
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• pp.25-32
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• 2021

This study examined the effects of kinesio taping on recovery from fatigue induced by an exercise of concentric contraction using an isokinetic machine. The fatigue was introduced by a mode of exercise at 60°/sec, 50 repetitions for three sessions. The changes of blood ammonia, lactate, LDH, and CK as a marker of fatigue were monitored. Eight healthy collegiate students participated in two experiments; 1) kinesio taping application condition and 2) no kinesio taping application condition. Before experiments, their physical characteristics were measured. For the experiment, blood samples were taken before and immediately after exercise, and 24hr as well as 72hr of recovery period. Window SPSS package 12.0 version was used and one-way ANOVA with repeated measures were employed. The results were as follows. 1) Blood ammonia tended to reduce along the recovery, but no differences between conditions were noticed. 2) Blood lactate tended to reduce during the recovery period, but differences between conditions were not noticed. 3) The LDH was not different between conditions and CK tended to reduce during the recovery period, but differences between conditions were not noticed. Based on the results, kinesio taping did not influence on recovery phase of blood ammonia, lactate concentration, LDH, and CK.

• Korean Journal of Exercise Nutrition
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• v.16 no.1
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• pp.19-26
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• 2012

The purpose of this study was to analyze the effects of intake of aronia, montmorency, and Prunus mume on 10 km endurance exercise by investigating changes in blood lactate, ammonia, creatine kinase (CK), and lactate dehydrogenase (LDH), and eventually to recommend them as ergogenic aids, which are effective for recovering from exercise fatigue and muscle damage. The subjects were divided into a P. mume intake group, an aronia intake group, a montmorency intake group, and a control group. Blood samples were taken from the brachial vein at rest, and at 0, 30 min, and 24 hr after running to measure recovery status. All data were analyzed by a two-way repeated-measures analysis of variance using SPSS. The results are summarized as follows: The changes in blood ammonia and LDH concentration following 10 km of running were not significantly different among the groups. However, lactate and CK recovery ratio increased significantly in the aronia and montmorency groups compared to those in the P. mume and control groups. In particular, CK concentration was significantly different in the montmorency group compared to that in the other groups. These results suggest that the effects of aronia and montmorency are associated with improved recovery from muscle fatigue and damage induced by highly intensive exercise, endurance exercise, or overtraining. In particular, montmorency is recommended as an ergogenic aid to inhibit muscle pain resulting from high-intensity endurance exercise.