• Journal of Ginseng Research
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• 제39권4호
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• pp.314-321
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• 2015

Background: Ginseng belongs to the genus Panax. Its main active ingredients are the ginsenosides. Interstitial cells of Cajal (ICCs) are the pacemaker cells of the gastrointestinal (GI) tract. To understand the effects of ginsenoside Re (GRe) on GI motility, the authors investigated its effects on the pacemaker activity of ICCs of the murine small intestine. Methods: Interstitial cells of Cajal were dissociated from mouse small intestines by enzymatic digestion. The whole-cell patch clamp configuration was used to record pacemaker potentials in cultured ICCs. Changes in cyclic guanosine monophosphate (cGMP) content induced by GRe were investigated. Results: Ginsenoside Re ($20-40{\mu}M$) decreased the amplitude and frequency of ICC pacemaker activity in a concentration-dependent manner. This action was blocked by guanosine 50-[${\beta}-thio$]diphosphate [a guanosine-5'-triphosphate (GTP)-binding protein inhibitor] and by glibenclamide [an adenosine triphosphate (ATP)-sensitive $K^{+}$ channel blocker]. To study the GRe-induced signaling pathway in ICCs, the effects of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (a guanylate cyclase inhibitor) and RP-8-CPT-cGMPS (a protein kinase G inhibitor) were examined. Both inhibitors blocked the inhibitory effect of GRe on ICC pacemaker activity. L-NG-nitroarginine methyl ester ($100{\mu}M$), which is a nonselective nitric oxide synthase (NOS) inhibitor, blocked the effects of GRe on ICC pacemaker activity and GRe-stimulated cGMP production in ICCs. Conclusion: In cultured murine ICCs, GRe inhibits the pacemaker activity of ICCs via the ATP-sensitive potassium ($K^{+}$) channel and the cGMP/NO-dependent pathway. Ginsenoside Re may be a basis for developing novel spasmolytic agents to prevent or alleviate GI motility dysfunction.

• The Korean Journal of Physiology
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• 제19권1호
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• pp.1-13
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• 1985

The influences of $Ca^{2+}-antagonists$, verapamil and $Mn^{2+}$, upon the spontaneous electrical activity and contractions were studied in guinea-pig taenia coli. Spontaneous contractions were recorded with force transducer, and spike action potentials were measured extracellularly by use of suction electrode. All experiments were performed in tris-buffered Tyrode solution Which was aerated With 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows : 1) Verapamil suppressed the frequency and amplitude of spontaneous contractions dose dependently, and blocked completely mechanical responses at the concentration of 1 mg/1. 2) The frequency of bursts of spike discharge(bursts frequency) and the number of spikes in a burst(spikes frequency) were reduced in a dose·dependent manner within the concentration range of $10^{-5}$ to $10^{-3}g/l$, and bursts frequency was affected more readily at a low concentration of $10^{-5}g/l$ verapamil. 3) The verapamil_induced suppression of spontaneous contractions in the Tyrode solution containing 1 mM $Ca^{2+}$ was completely antagonized by the addition of extra $Ca^{2+}$ to the Tyrode solution $(2\;m\;MCa^{2+})$. 4) $Mn^{2+}$ suppressed the amplitude of spontaneous contractions, whereas $Mn^{2+}$ accelerated the frequency dose-dependently within the range of low concentrations$(10^{-7}\;to\;10^{-4}\;M\;Mn^{2+})$. 5) The bursts frequency determining frequency of spontaneous contractions was increased in a dose-dependent manner, whereas the spikes frequency known to determine the contractions amplitude was reduced within the range of low concentrations. At a high concentration of 1 mM $Mn^{2+}$, however, all spontaneous contractile responses were blocked simultaneously with the disapperance of electrical activity. 6) The frequency and amplitude of spontaneous contractions altered by $Mn^{2+}$ in 1mM $Ca^{2+}$ Tyrode were increased by extra $Ca^{2+}(2mM)$.

• Annals of Clinical Neurophysiology
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• 제12권1호
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• pp.16-20
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• 2010

Background: The medial plantar nerve (MPN) is a distal branch of the posterior tibial nerve, and various methods of nerve conduction study for MPN have been introduced so far. Hemmi et al described a new method (Hemmi's method) for recording medial plantar sensory nerve action potentials (SNAPs), which is considered as a simple and reliable method for measuring medial plantar SNAPs. This study was aimed to establish the normal values for the MPN conduction study among Koreans and to compare the sensitivities of three different methods for MPN conduction study (Hemmi, Oh, and Saeed's method) in detecting evidence of peripheral neuropathy among diabetic patients. Methods: In 27 healthy subjects, MPN conduction study using Hemmi's method was performed and normal values were calculated. In 54 diabetic patients who showed normal routine nerve conduction studies, three different methods for MPN conduction study were performed and diagnostic sensitivity of each method were compared. Results: In normal subjects, the mean medial plantar SNAP amplitude and conduction velocities measured by Hemmi's method were $4.3{\pm}1.0$ uV and $38.3{\pm}6.8$ m/s respectively. Among 54 patients with diabetes who showed normal routine nerve conduction studies, medial plantar SNAP was not obtainable in 28, 31, and 6 patients by Hemmi, Oh and Saeed's method respectively. Conclusions: In terms of the diagnostic sensitivity for detecting diabetic neuropathy, there had been no significant statistical difference between three different methods. Our study suggested that MPN conduction study using Hemmi's method is simple and useful screening test for early diabetic neuropathy, and is comparable with Oh's method.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2787-2790
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• 2014

Quercetin is a major dietary flavonoid found in onions, apples, tea, and red wine, and potentially has beneficial effects on disease prevention. We carried out this study to investigate the effect of quercetin on UVB-induced matrix metalloproteinase-1 (MMP-1) expression in human keratinocyte HaCaT cells and to further understand the mechanisms of its action. The anti-inflammatory activity of quercetin was investigated and quercetin significantly suppressed the NO production in LPS-stimulated RAW264.7 mouse macrophages. Post treatment of quercetin decreased UV irradiation-induced phosphorylation of JNK, p38 MAPK, and ERK by 91%, 21%, and 17%, respectively. MMP-1 is mainly responsible for the degradation of dermal collagen during the aging process of human skin and quercetin suppressed the UVB-induced MMP-1 by 94%. Binding studies revealed that quercetin binds to p38 with high binding affinity ($1.85{\times}10^6M^{-1}$). The binding model showed that the 4'-hydroxy groups of the B-ring of quercetin participated in hydrogen bonding interactions with the side chains of Lys53, Glu71, and Asp168 and the 5-hydroxy group of the A-ring formed a hydrogen bond with the backbone amide of Met109. The major finding of this study shows that quercetin inhibits phosphorylation of JNK, p38 MAPK, and ERK pathway leading to the prevention of MMP-1 expression in human keratinocyte HaCaT cells. Therefore, our findings suggested the potentials of quercetin as a skin anti-photoaging agent.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.532-534
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• 2004

The advancement of electronics and telecommunication technologies has forced the risk management system for underground metallic structures to evolve into the remote monitoring and control system. Especially, facilities such as gas pipelines, oil pipelines and water distribution lines might make hazardous effect on human safety without continuous monitoring and control. As a result, pipeline engineers have applied cathodic protection system to prevent the degradation of their facilities by corrosion and carried out a periodic monitoring of the pipe-to-soil (P/S) potentials at numberous test boxes along their pipelines. The latter action on a road in downtowns, however, is so much dangerous that the inspectors should be ready to suffer the threatening of their lives and maintenance. In order to minimize these social costs and hazards, a stand-alone type corrosion monitoring equipment which can be installed in test box, store the P/S data for given Belied and send the data by wired/wireless telecommunications is under development. In order to obtain the exact P/S data, however, a reference electrode should be located as close to the pipeline as possible. Actually, the measured potential by a conventional portable reference electrode contain inevitably an IR drop portion caused by the current flow from the cathodic protection rectifier or the subway railroad. To minimize this error, it is recommended that the reference electrode should be buried within 10 cm from the pipeline. In this paper, we describe the design parameters for fabricating the permanent type reference electrode and the characteristics of the developed reference electrode.

• 한국물환경학회지
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• 제28권1호
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• pp.115-120
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• 2012

Different colloidal particles generally co-exist in the water and wastewater. Thus, there needs to identify practical electrokinetic characteristics of the particles, comparing with the case when each colloidal material is independently distributed. In this study, changes of overall zeta potential was examined through mixed dispersions of $TiO_{2}$ and $MnO_{2}$. The mixing ratios were classified into 3-type in order to distinguish the effects of the proportions of each particle from those of total concentration in colloidal suspensions. The types are single colloidal dispersions of $TiO_{2}$ and $MnO_{2}$ (1:0, 0:1), mixed dispersions at different ratios (0.75:0.25, 0.5:0.5, 0.25:0.75), and a mixed dispersion with doubled concentration (1:1), respectively. It showed that the overall variation of zeta potential as a function of pH was intensified in a colloidal dispersion with the ratio of 1:1. It was concerned that the double action of ion would contribute to this result. On the one hand, the zeta potentials of each colloidal dispersion commonly decreased at the state of strong acid and base under the influence of compression of the electric double layer. The changing patterns were also considered through calculating total interaction energy between colloidal particles based on DLVO theory and measuring turbidity of the colloidal dispersions.

• Restorative Dentistry and Endodontics
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• 제21권1호
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• pp.425-435
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• 1996

The effect of application of dentin bonding agent to the exposed dentin on the intradental nerve activity (INA), dentinal fluid movement and sealing of the dentinal tubules, was investigated in this study. The INA was recorded from the single pulp nerve unit dissected from the inferior alveolar nerve. And specimen of dentin was observed by SEM. Dentinal fluid 'movement through exposed dentin surface was measured before and after the application of dentin bonding agent. 1. Eight Ao-fiber units (conduction velocity: $8.0{\pm}4.0m$/sec) were identified. 4M NaCl evoked an irregular burst of action potentials which ceased immediately after washing. 2. In 4 $A{\delta}$-fiber units, appliction of All Bond 2 completely abolished the INA induced by 4M NaCl. Also, application of Scotchbond Multipurpose(SBMP) totally abolished the INA induced by 4M NaCl in 4 $A{\delta}$-fiber units. 3. Before the application of dentin bonding agent, outward dentinal fluid movement of $10.2{\pm}5.7\;pl{\cdot}s^{-1}{\cdot}mm^{-2}$ was obsered. But after the application of dentin bonding agent the movement of dentinal fluid was stopped. 4. The gap width of 2-$3{\mu}m$ was formed between exposed dentin and adhesive resin in the specimens applied with dentin bonding agents of All Bone 2 and SBMP. But the formation of hybrid layer and the penetration of resin into were dentinal tubules were not clearly observed in interface between dentin and adhesive resin.

• Asian-Australasian Journal of Animal Sciences
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• 제27권9호
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• pp.1368-1372
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• 2014

Several studies arduously reported that gayal (Bos frontalis) is an independent bovine species. The population size is shrinking across its distribution. In Bangladesh, it is the only wild relative of domestic cattle and also a less cared animal. Their body size is much bigger than Bangladeshi native cattle and has prominent beef type characters along with the ability to adjust in any adverse environmental conditions. Human interactions and manipulation of biodiversity is affecting the habitats of gayals in recent decades. Besides, the only artificial reproduction center for gayals, Bangladesh Livestock Research Institute (BLRI), has few animals and could not carry out its long term conservation scheme due to a lack of an objective based scientific mission as well as financial support. This indicates that the current population is much more susceptible to stochastic events which might be natural catastrophes, environmental changes or mutations. Further reduction of the population size will sharply reduce genetic diversity. In our recent investigation with 80K indicine single nucleotide polymorphism chip, the $F_{IS}$ (within-population inbreeding) value was reported as $0.061{\pm}0.229$ and the observed ($0.153{\pm}0.139$) and expected ($0.148{\pm}0.143$) heterozygosities indicated a highly inbred and less diverse gayal population in Bangladesh. Prompt action is needed to tape the genetic information of this semi-domesticated bovine species with considerable sample size and try to investigate its potentials together with native zebu cattle for understanding the large phenotypic variations, improvement and conservation of this valuable creature.

• 대한물리치료과학회지
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• 제9권3호
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• pp.77-87
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• 2002

The purpose of this study was to compare the changes of muscle activities in deltoid with those in supraspinatus using electromyography(EMG) while subjects abducted their shoulder to different angles with different resistance. Methods : 20 volunteers who were comprised of 10 males(mean age: $21.2{\pm}2.0$) and 10 females(mean age: $20.2{\pm}1.6$) were collected. Surface electrodes were attached on deltoid and supraspinatus muscle for recording. Each reference electrode was located 3 cm to the each recording electrode. Muscle action potentials were recorded with changing the angle of shoulder abduction, $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. This procedure was repeated with different resistance 0 pound, 2 pounds, 4.5pounds. The angle of shoulder abduction was determined by clinical goniometer. SPSS(Statistical Program for Social Science)/WIN 10.0 was used for statistics. Analysis included ANOVA, T-test. Results : The following results were obtained in this study. 1. There was significant differences during isometric shoulder abduction $30^{\circ}$, $60^{\circ}$, $90^{\circ}$ comparing muscle activity in deltoid and supraspinatus muscles at 0 pound, 2pound, 4.5pound resistance(p<0.05). 2. There was no useful significant in the deltoid and supraspinatus muscles activity EMG compared by physical condition. 3. Their was significant in the deltoid EMG compared by gender t=-5.41, P<0.01, but no difference in the supraspinatus EMG(P=0.333 >a=0.05). Conclusions: There are many previous studies on influence of shoulder angles and speeds of muscle activity. However most of them placed the focus on isotonic or isokinetic exercise, or shoulder function. But this study was done during isometric exercise, which is better for early assessment and treatment for injured patients. There is strong relationship between the shoulder angle with resistance in deltoid supraspinatus muscle activity. We conclude that it is important to apply isometric shoulder abduction exercise with correct angle and resistance especially in early stage.

• The Korean Journal of Physiology
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• 제25권2호
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• pp.147-158
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• 1991

The effects of noradrenaline on the spontaneous contraction recorded from a strip of mucosa-free antral circular muscle were studied in the guinea-pig stomach, and the changes in slow waves and membrane resistance were analyzed in order to elucidate the mechanism for the excitatory response to noradrenaline. Electrical responses of circular muscle cells were recorded using glass microelectrodes filled with 3 M KCI. Electrotonic potentials were produced to estimate membrane resistance by the partition stimulating method. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) The spontaneous contractions were potentiated dose-dependently by the application of noradrenaline. 2) Through the experiments using adrenoceptor-blockers, the strong excitatory effect via $[\alpha}-adrenoceptors$ and the weak inhibitory efffect via ${\beta}-adrenoceptors$ were noted. 3) Noradrenaline produced hyperpolarization of membrane potential, and increases in the amplitude and the maximum rate of rise of slow waves. 4) In the presence of apamin, Ca-dependent K channel blocker, the characteristic hyperpolarization was not developed. However, the excitatory effect of noradrenaline on spontaneous contraction remained. 5) Membrane resistance was reduced during the hyperpolarized state by the application of noradrenaline, and the change of membrane resistance and the hyperpolarized state were completely abolished by apamin. From the above results, following conclusions could be made: Excitatory responses to noradrenaline result from the dominant ${\alpha}-excitatory$, and the weak ${\beta}-inhibitory$ action of noradrenaline. Hyperpolarization of membrane potential by noradrenaline is due to the activation of Ca-dependent K channel.