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Aim: Normal individuals are risk averse for decisions framed as gains but risk taking for decisions framed as losses. This framing effect is supposed to be attenuated in Alzheimer's disease (AD) patients. We investigated the effects of highlighting rewards versus highlighting punishments on the risky decision-making of AD patients. Method: Fourteen mild to moderate AD patients (Mini-Mental Status Examination score, 11–23; Clinical Dementia Rating, 1–2) and 16 healthy volunteers were recruited for the study. Subjects completed a computerized task on risky decision-making in which mathematically equivalent dilemmas were presented in terms of opportunities to gain monetary rewards (‘positive frame’) or avoid suffering losses (‘negative frame’). Results: As expected, AD patients chose more risky options under the positive frame than the negative frame, contrary to the control group (Z =−2.671, P= 0.007). The normal difference in the distribution of risky choices between positively and negatively framed dilemmas was significantly reduced in the AD group after we adjusted for years of education, mean age and depression (F= 5.321, P= 0.030). Deliberation time did not differ significantly between the two groups. Conclusion: These results suggest that AD patients making high-risk choices is associated with attenuated sensitivity to the emotional frames that highlight rewards or punishments, possibly reflecting altered evaluations of prospective gains and losses.

Mast cells are the principal effector cells involved in the allergic response, through the release of histamine. We investigated the effect of eriodictyol, derived from the painted maple and yerba santa, on mast cell degranulation and on an allergic response in an animal model. We also investigated its effect on the expression of the ceramide kinase (CERK) involved in calcium-dependent degranulation, and on ceramide activation by multiple cytokines. Eriodictyol suppressed the release of beta-hexosaminidase, a marker of degranulation, and the expression of interleukin (IL)-4 mRNA. It inhibited the expression of CERK mRNA, reduced the ceramide concentration in antigen-stimulated mast cells, and suppressed the passive cutaneous anaphylaxis (PCA) reaction in mice in a dose-dependent manner. These results suggest that eriodictyol can inhibit mast cell degranulation through inhibition of ceramide kinase, and that it might potentially serve as an anti-allergic agent.

Mast cells, the central effector cells involved in the allergic response, release histamine, arachidonic acid, and proinflammatory cytokines. We investigated the effect of the ethyl acetate fraction (EA), derived from Korean rice wine lees, on RBL-2H3 cell degranulation and passive cutaneous anaphylaxis in an animal model. The EA fraction suppressed the release of beta-hexosaminidase, a marker of degranulation, and the mRNA expression of interleukin-3 (IL-3) and IL-13. EA also successfully suppressed the passive cutaneous anaphylaxis (PCA) reaction in mice in a dose-dependent manner. These results suggest that EA can inhibit mast cell degranulation through the inhibition of IL-3 and IL-13 mRNA expression, and that EA may potentially serve as an anti-allergic agent.

Ceramide 1-phosphate (C1P) is a novel bioactive sphingolipid formed by ceramide kinase (CERK)-catalyzed phosphorylation of ceramide. It has been implicated in the regulation of such vital pathophysiological functions as phagocytosis and inflammation, but there have been no reports ascribing a biological function to CERK in vascular disorders. Here the potential role of CERK/C1P in neointimal formation was investigated using rat aortic vascular smooth muscle cells (VSMCs) in primary culture and a rat carotid injury model. Exogenous C8-C1P stimulated cell proliferation, DNA synthesis, and cell cycle progression of rat aortic VSMCs in primary culture. In addition, wild-type CERK-transfected rat aortic VSMCs induced a marked increase in rat aortic VSMC proliferation and [(3)H]-thymidine incorporation when compared to empty vector transfectant. C8-C1P markedly activated extracellular signal-regulated kinase 1 and 2 (ERK1/2) within 5min, and the activation could be prevented by U0126, a MEK inhibitor. Also, K1, a CERK inhibitor, decreased the ERK1/2 phosphorylation and cell proliferation on platelet-derived growth factor (PDGF)-stimulated rat aortic VSMCs. CERK expression and C1P levels were found to be potently increased during neointimal formation using a rat carotid injury model. However, ceramide levels decreased during the neointimal formation process. These findings suggest that C1P can induce neointimal formation via cell proliferation through the regulation of the ERK1/2 protein in rat aortic VSMCs and that CERK/C1P may regulate VSMC proliferation as an important pathogenic marker in the development of cardiovascular disorders.

Most living organisms exhibit circadian rhythms in physiology and behavior. These oscillations are generated by an endogenous circadian clock and control many biological processes. Ceramide has attracted attention as a signal mediator in diverse cell processes including cell death and differentiation. The relationships between ceramide expression levels and the circadian clock have not previously been investigated. To determine if there are circadian variations in the content of ceramide, we measured ceramide concentrations in the livers of wild-type (WT) and mPer1/mPer2 double knockout (DKO) mice. The ceramide concentration in WT mice was dramatically increased at Zeitgeber Time 9 (ZT9; 9 h after lights-on time) and ZT21 but no rhythmicity in ceramide expression was seen in DKO mice. Because ceramide can be generated by the hydrolysis of sphingomyelin via sphingomyelinase (SMase), or by ceramide synthase (CerS)-mediated synthesis, we assayed the expression patterns of ceramide-related genes using real-time PCR. CerS2 expression levels showed a biphasic pattern of expression in WT mice but no rhythmicity in DKO mice. While the neutral SMase (nSMase) and acidic SMase (aSMase) mRNA in WT mice were expressed in a circadian manner, the correlation between the expression levels of these SMases with times of day was weak in DKO mice. Collectively, our findings suggest that both SMases and CerS2 mRNA expression are regulated by the presence of mPer1/mPer2 circadian clock genes in vivo, and imply that ceramide may play a vital role in circadian rhythms and physiology.

Skin aging is related to genetic and environmental factors (e.g ., gene mutation and UV radiation re- spectively). To develop a new anti-wrinkle cosmetic or function al food by using Korean rice wine cake, we examined the effects of Korean rice wine cake, a brewery byp roduct, on antioxidant effect, collagen synthesis and expression of MMP-1. Interestingly, we found that Korean rice wine cake has the ability to promote scavenging activity of DPPH radical. We also found that the cell proliferation and synthesis of collagen in HS27 cells was increased by Korean rice wine cake in a concentration-dependent manner. However, elastase inhibitory activity was not changed. In addit ion, the expression of MMP-1 was in- hibited by Korean rice wine cake in a concentration-dependent m anner. All these results suggest that Korean rice wine cake can be effectively used for the prevention of wrinkles in human skin.

Muscle disorders, such as muscular dystrophy, are associated with an increase in oxidative stress. Proposed treatments for muscular dystrophy, some in clinical trials, include gene therapy and muscle cell transplantation. In this study, we investigated the effects of idesolide, isolated from the fruits of Idesia polycarpa, on changes that occur in muscle disuse atrophy. We noted protective effects on oxidative stress response and HSP70 regulation. Pre-treatment with idesolide for 24 h maintained cell viability and decreased apoptosis in H(2)O(2)-treated C(2)C(12) muscle cells. The idesolide pretreatment also increased intracellular HSP70 protein. Our results suggest that idesolide inhibits cell death through induction of HSP70 in C(2)C(12) muscle cells. This work is the first to report that idesolide can regulate the decrease in HSP70 that occurs during skeletal muscle atrophy.

This article examines the impact of knowledge sharing on individual work performance by analyzing perceptions of 323 public employees in South Korea. An analytical model is drawn from an extensive review of literature on knowledge management and sharing from which nine exogenous variables are identified as antecedents of knowledge sharing that affect individual work performance. The results indicate that four exogenous variables—employee training, reward systems, support from the top management, and openness in communication—are perceived to have a positive influence on employees' knowledge sharing, which, in turn, improved individual work performance. Perceived trustworthiness between individuals involved in knowledge sharing has also positively influenced both knowledge sharing and individual work performance. These results imply that individual work performance may be dependent on the effective use of knowledge sharing.

We report on two additional cases of metformin-associated encephalopathy in patients with end-stage renal disease (ESRD) undergoing hemodialysis. Two patients were seen at our hospital with abnormal neurological signs and symptoms. Magnetic resonance imaging (MRI) revealed the same pattern of high signal intensity in both basal ganglia in T2-weighted images in the two patients. The two patients had started taking metformin 5 and 6 weeks earlier at the same dose of 1000 mg per day. Metformin was immediately stopped, and regular hemodialysis was conducted. Their signs and symptoms resolved completely after these measures. The high signal intensity in both ganglia in T2-weighted MRI also disappeared. We should suspect metformin-induced encephalopathy and withdraw the drug when presented with diabetic patients with chronic kidney disease and neurological signs and symptoms of unknown cause.