• Mycobiology
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• v.39 no.4
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• pp.283-289
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• 2011

The wild edible mushroom, Lentinus lepideus has recently been cultivated for commercial use in Korea. While the mushroom has been widely used for nutritional and medicinal purposes, the possible anti-hyperlipidemic action is unclear. The effects of dietary L. lepideus on plasma and feces biochemical and on the liver histological status were investigated in hypercholesterolemic rats. Six-wk-old female Sprague-Dawley albino rats were divided into three groups of 10 rats each. Biochemical and histological examinations were performed. A diet containing 5% L. lepideus fruiting bodies reduced plasma total cholesterol, triglyceride, low-density lipoprotein, total lipid, phospholipids, and the ratio of low-density to high-density lipoprotein. Body weight was reduced. The diet did not adversely affect plasma biochemical and enzyme profiles. L. lepideus reduced significantly plasma ${\beta}$- and pre-${\beta}$-lipoprotein, while ${\alpha}$-lipoprotein content was increased. A histological study of hepatic cells by conventional hematoxylin-eosin and oil red O staining revealed normal findings for mushroom-fed hypercholesterolemic rats. The present study suggests that a diet supplemented with L. lepideus can provide health benefits by acting on the atherogenic lipid profile in hypercholesterolemic rats.

• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.357-366
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• 2004

We studied the effect of propofol (PPF) on the endothelium-dependent vascular responses in isolated rat thoracic aorta. In aortic rings with endothelium, PPF inhibited the phenylephrine (PE)-induced contraction in a concentration-dependent manner. In PE-precontracted preparations, PPF attenuated the endothelium-dependent relaxation by acetylcholine but not by A23187. And PPF did not attenuate the endothelium-independent relaxation by sodium nitroprusside (SNP). The relaxation induced by acetylcholine in PE-precontracted aortic rings was significantly augmented by zaprinast, a cGMP-specific phosphodiesterase inhibitor, and this augmentation was inhibited by PPF. Although SNP-induced relaxation was significantly augmented by zaprinast, this augmentation was not inhibited by PPF. In preparations preconstricted with PE, the PPF-induced relaxation was inhibited by atropine. In addition, PPF attenuated the vasorelaxation by phosphodiesterase inhibitors (IBMX, Ro20-1724 or zaprinast except milrinone). In vivo, the infusion of acetylcholine and SNP showed decreased arterial blood pressure in rats. The pre-injection of PPF inhibited the acetylcholine-induced blood pressure lowering, but not the SNP-induced blood pressure lowering. These results suggest that PPF can attenuate in part the acetylcholine-induced vasorelaxation and blood pressure lowering through the inhibition of the acetylcholine receptor-mediated endothelium-derived relaxing factor by acting on endothelium. It is considered that the inhibitory effect of PPF on the vasorelaxation is due to the decreased level of cGMP which can be attributed to the inhibition of the muscarinic receptor and/or receptor-G-protein interaction.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.168-173
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• 1998

A single administration of cocaine (CO), morphine (MOR) and methamphetamine (MA) showed hyperactivity in mice. Ginseng total saponin (GTS), ginsenosides Rbl and Rgl inhibited the hyperactivity induced by the drugs. The repeated administration of CO, MOR and MA showed the development of psychological dependence showing a.: the development of conditioned place preference (CPP) in mice and the development of dopamine (DA) receptor supersensitivity showing as sensitization of the drugs. GTS and Rgl inhibited the development of not only psychological dependence but also of DA receptor supersensitivity induced by CO and MA Rbl prevented also the development of psychological dependence and DA receptor supersensitivity induced by CO and MA but not by MOR. These results suggest that the development psychological dependence induced by the drugs is closely related with the development of DA receptor supersensitivity since both phenomena were inhibited by them. Apomorphine induced climbing behavior was also inhibited by G75 but not by both of Rbl and Rgl, indicating that GTS modulate dopaminergic action at both of pre and postsynaptic sites, but both of Rbl and Rgl , only at the presynaptic site. These results suggest that active components acting at the postsynaptic site exist in GTS. In this study, it was found that GTS, ginsenosides Rbl and Rgl inhibited tyrosine hydroxylase (TH) and these components exerted inhibitory effects on both Cal' currents and $\Delta$ Cm in rat adrenal chromaffin cells. These results suggest that G75 and ginsenosides regulate catecholamine synthesis and secretion. Meanwhile, it has been demonstrated that Rbl, at high doses has more powerful inhibition of cartecholamine secretion at the presynaptic site than Rbl. Therefore, it was presumed that inhibition of morphine induced psychological dependence by Rgl, but not by Rbl results from differences in the extent of this inhibitory action on dopaminergic synthesis and secretion.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.4
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• pp.73-81
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• 1987

Dynamic analysis of tethers and platforms of tension leg platforms(TLP's) subjected to wave forces is presented in this paper. The efficient platform analysis model which can adequately include the dynamic characteristics of tethers is proposed, and the platform motion analyses are mainly carried out using this model. Also, the tether analyses are performed utilizing the finite element method with geometric stiffnesses due to the pre-tension in tethers. Two different. TLP's located in 1000 ft and 3000 ft waters are chosen as example structures. For the purpose of comparison, analyses are also carried out by two different models. One is the conventional model in which the tethers are idealized as weightless springs. The other is the coupled model of platform and tethers. A comparison has been made between the results obtained by three different models mentioned above. Also, effects of the conventional stiffnesses of tethers and the wave exciting forces acting on tethers for the tether responses are examined.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.582-588
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• 2007

Since the turnout system in railroad restricts the train speed, the KNR (Korean National Railroad) provides the specification for the speed (130km/h) of the train when the train passes the turnout system. Therefore, the turnout system in pre-existing railroad is necessary to be improved to speed-up for the train. In this study, the dynamic wheel-load field tests have been performed to evaluate the track performance and the roadbed bearing capacity has been examined using numerical analysis at the turnout crossing in the conventional and improved turnout system. The impact factor is estimated using the data sets achieved from the dynamic wheel-load field tests in the conventional and improved turnout system. The stress acting on the roadbed for the improved turnout system is substantially decreased compare to that for the conventional turnout system.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.419-426
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• 2019

Mosapride accelerates gastric emptying by acting on 5-hydroxytryptamine type 4 ($5-HT_4$) receptor and is frequently used in the treatment of gastrointestinal (GI) disorders requiring gastroprokinetic efficacy. We tested the effect of mosapride on 5-hydroxytryptamine type 3 ($5-HT_3$) receptor currents because the $5-HT_3$ receptors are also known to be expressed in the GI system and have an important role in the regulation of GI functions. Using the whole-cell voltage clamp method, we compared the currents of the $5-HT_3$ receptors when 5-HT was applied alone or was co-applied with mosapride in cultured NCB-20 cells known to express $5-HT_3$ receptors. The $5-HT_3$ receptor current amplitudes were inhibited by mosapride in a concentration-dependent manner. Mosapride blocked the peak currents evoked by the application of 5-HT in a competitive manner because the $EC_{50}$ shifted to the right without changing the maximal effect. The rise slopes of $5-HT_3$ receptor currents were decreased by mosapride. Pre-application of mosapride before co-application, augmented the inhibitory effect of mosapride, which suggests a closed channel blocking mechanism. Mosapride also blocked the opened $5-HT_3$ receptor because it inhibited the $5-HT_3$ receptor current in the middle of the application of 5-HT. It accelerated desensitization of the $5-HT_3$ receptor but did not change the recovery process from the receptor desensitization. There were no voltage-, or use-dependency in its blocking effects. These results suggest that mosapride inhibited the $5-HT_3$ receptor through a competitive blocking mechanism probably by binding to the receptor in closed state, which could be involved in the pharmacological effects of mosapride to treat GI disorders.

• Molecules and Cells
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• v.42 no.6
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• pp.470-479
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• 2019

Interstitial cells of Cajal (ICCs) are pacemaker cells that exhibit periodic spontaneous depolarization in the gastrointestinal (GI) tract and generate pacemaker potentials. In this study, we investigated the effects of ghrelin and motilin on the pacemaker potentials of ICCs isolated from the mouse small intestine. Using the whole-cell patch-clamp configuration, we demonstrated that ghrelin depolarized pacemaker potentials of cultured ICCs in a dose-dependent manner. The ghrelin receptor antagonist [D-Lys] GHRP-6 completely inhibited this ghrelin-induced depolarization. Intracellular guanosine 5'-diphosphate-${\beta}$-S and pre-treatment with $Ca^{2+}$-free solution or thapsigargin also blocked the ghrelin-induced depolarization. To investigate the involvement of inositol triphosphate ($IP_3$), Rho kinase, and protein kinase C (PKC) in ghrelin-mediated pacemaker potential depolarization of ICCs, we used the $IP_3$ receptor inhibitors 2-aminoethoxydiphenyl borate and xestospongin C, the Rho kinase inhibitor Y-27632, and the PKC inhibitors staurosporine, Go6976, and rottlerin. All inhibitors except rottlerin blocked the ghrelin-induced pacemaker potential depolarization of ICCs. In addition, motilin depolarized the pacemaker potentials of ICCs in a similar dose-dependent manner as ghrelin, and this was also completely inhibited by [D-Lys] GHRP-6. These results suggest that ghrelin induced the pacemaker potential depolarization through the ghrelin receptor in a G protein-, $IP_3$-, Rho kinase-, and PKC-dependent manner via intracellular and extracellular $Ca^{2+}$ regulation. In addition, motilin was able to depolarize the pacemaker potentials of ICCs through the ghrelin receptor. Therefore, ghrelin and its receptor may modulate GI motility by acting on ICCs in the murine small intestine.

• Asia Marketing Journal
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• v.17 no.2
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• pp.39-62
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• 2015

Relatively little studies have investigated employee recovery from internal service failure, especially from the employees' perspective. When handling customer complaints, employees must not only deal with legitimate customer demands after a service failure, such as providing an apology, rectifying the problem, and offering compensation, but they must also manage illegitimate dysfunctional customers, who may yell, threaten, and even physically harm the employee. These negative experiences can have strong effects, and employees can exhibit higher levels of stress such as burnout and emotional labor, which have been linked to dissatisfaction, tension and anxiety, reduced performance and effectiveness, and a greater propensity to leave the firm, ultimately leading to negative financial consequences for the firm. These conditions result in internal service failure and create the need to recover employees-in other words, internal service recovery. However, little research has examined this issue so far. The purpose of the current study, therefore, is to investigate the relationship between internal service recovery and employee outcomes. A pre-test, post-test between-subjects experimental design was developed. Participants were 166 part-time students who were working full-time. The average age of the participants was 36.74 years, and 57.50% of them were female. The average length of employment was 13 years. Participants were randomly assigned to one of four groups of approximately equal size. Three of the groups were subjected to an experimental situation involving an internal service failure, while one group was not exposed to failure, thereby acting as a control group. This study contributes to the service marketing literature in several ways. First, the study extends service failure and/or recovery research by examining recovery in an employee context. Second, this study attempts to measure internal service recovery and to empirically demonstrate its relationship to employee outcomes. Third, this investigation emphasizes the managerial importance of internal service recovery. For example, understanding the nature of the relationships between internal service recovery and its consequences can improve the effectiveness and efficiency of managers' resource allocation decisions.

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.157-162
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• 2013

Methoxychlor (MXC) was developed to be a replacement for the banned pesticide DDT. HPTE [2,2-bis (p-hydroxyphenyl)-1,1,1-trichloroethane], which is an in vivo metabolite of MXC, has strong oestrogenic and anti-androgenic effects. MXC and HPTE are thought to produce potentially adverse effects by acting through oestrogen and androgen receptors. Of the two, HPTE binds to sex-steroid receptors with greater affinity, and it inhibits testosterone biosynthesis in Leydig cells by inhibiting cholesterol side-chain cleavage enzyme activity and cholesterol utilisation. In a previous study, MXC was shown to induce Leydig cell apoptosis by decreasing testosterone concentrations. I focused on the effects of MXC on male mice that resulted from interactions with sex-steroid hormone receptors. Sex-steroid hormones affect other organs including the kidney and liver. Accordingly, I hypothesised that MXC can act through sex-steroid receptors to produce adverse effects on the testis, kidney and liver, and I designed our experiments to confirm the different effects of MXC exposure on the male reproductive system, kidney and liver. In these experiments, I used pre-pubescent ICR mice; the puberty period in ICR mice is from postnatal day (PND) 45 to PND60. I treated the experimental group with 0, 100, 200, 400 mg MXC/kg b.w. delivered by an intra-peritoneal injection with sesame oil used as vehicle for 4 weeks. At the end of the experiment, the mice were sacrificed under anaesthesia. The testes and accessory reproductive organs were collected, weighed and prepared for histological investigation. I performed a chemiluminescence immune assay to observe the serum levels of testosterone, LH and FSH. Blood biochemical determination was also performed to check for other effects. There were no significant differences in our histological observations or relative organ weights. Serum testosterone levels were decreased in a dose-dependent manner; a greater dose resulted in the production of less testosterone. Compared to the control group, testosterone concentrations differed in the 200 and 400 mg/kg dosage groups. In conclusion, I observed markedly negative effects of MXC exposure on testosterone concentrations in pre-pubescent male mice. From our biochemical determinations, I observed some changes that indicate renal and hepatic failure. Together, these data suggest that MXC produces adverse effects on the reproductive system, kidney and liver.

• Korean Journal of Ichthyology
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• v.12 no.1
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• pp.38-45
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• 2000

Depending on the fish species the vascular tone is distinctively regulated by numerous vasoactive substances. In most fish species the regulatory role of autonomic neurotransmitters and other vasoactive substances are not well defined. This research was designed to delineate the regulatory role of various endogenous autonomic neurotransmitters known to be important in mammalian vascular systems on isolated Israeli carp ventral aorta. Acetylcholine(ACh) contracted the aorta regardless of the pre-existing level of vascular tone, and the contraction was almost completely abolished by a cholinergic-muscarinic antagonist atropine. Endogenous, multiple receptor ($\alpha$ and $\beta$)-acting adrenergic agonist epinephrine (Epi) relaxed the vessel in the presence and absence of the pre-existing tones. Another endogenous multiple receptoracting agonist norepinephrine (NE) weakly contracted the aorta in non-preconstrcted state, but the response was reversed to relaxation when preconstricted. Isoproterenol, ${\alpha}\;{\beta}$ adrenergic receptor agonist, was a potent vasodilator whereas an ${\alpha}_1$ agonist phenyephrine was a contractor. The ${\alpha}_2$ adrenergic receptor agonist clonidine has not any significant effect in altering the vascular tone. The vasorelaxing action of Epi, NE and isoproterenol was significantly attenuated by $\beta$ receptor antagonist propranolol. These results imply that ACh may primarily play a contractor role via muscarinic receptor activation while adrenergic agonists, Epi and NE, are relaxants through activation of $\beta$ adrenergic receptors in vivo.