• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.69-71
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• 1989

Effects of SDS and temperature on the conformational changes of bacteriorhodopsin were studied using a, b, c bands of bacteriorhodopsin. In the SDS denaturation, bacteriorhodopsin in purple membrane was more labile than bacteriorhodopsin reconstituted into PC vesicles. These rather interesting results may be understood by effective SDS concentration in lipid layer.

• Membrane Journal
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• v.21 no.3
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• pp.222-228
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• 2011

Poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) graft copolymer was synthesized via atom transfer radical polymerization (ATRP) and used as an electrolyte for electrochromic device. Plasticized polymer electrolytes were prepared by the introduction of propylene carbonate (PC)/ethylene carbonate (EC) mixture as a plasticizer. The effect of salt was systematically investigated using lithium tetrafluoroborate ($LiBF_4$), lithium perchlorate ($LiClO_4$), lithium iodide (LiI) and lithium bistrifluoromethanesulfonimide (LiTFSI). Wide angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) measurements showed that the structure and glass transition temperature ($T_g$) of polymer electrolytes were changed due to the coordinative interactions between the ether oxygens of POEM and the lithium salts, as supported by FT-IR spectroscopy. Transmission electron microscopy (TEM) showed that the microphase-separated structure of PVC-g-POEM was not greatly disrupted by the introduction of PC/EC and lithium salt. The plasticized polymer electrolyte was applied to the electrochromic device employing poly(3-hexylthiophene) (P3HT) conducting polymer.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.4
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• pp.297-305
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• 2014

Flavonoids have an ability to suppress various ion channels. We determined whether one of flavonoids, cyanidin-3-glucoside, affects adenosine 5'-triphosphate (ATP)-induced calcium signaling using digital imaging methods for intracellular free $Ca^{2+}$ concentration ([$Ca^{2+}$]i), reactive oxygen species (ROS) and mitochondrial membrane potential in PC12 cells. Treatment with ATP ($100{\mu}M$) for 90 sec induced [$Ca^{2+}$]i increases in PC12 cells. Pretreatment with cyanidin-3-glucoside ($1{\mu}g/ml$ to $100{\mu}g/ml$) for 30 min inhibited the ATP-induced [$Ca^{2+}$]i increases in a concentration-dependent manner ($IC_{50}=15.3{\mu}g/ml$). Pretreatment with cyanidin-3-glucoside ($15{\mu}g/ml$) for 30 min significantly inhibited the ATP-induced [$Ca^{2+}$]i responses following removal of extracellular $Ca^{2+}$ or depletion of intracellular [$Ca^{2+}$]i stores. Cyanidin-3-glucoside also significantly inhibited the relatively specific P2X2 receptor agonist 2-MeSATP-induced [$Ca^{2+}$]i responses. Cyanidin-3-glucoside significantly inhibited the thapsigargin or ATP-induced store-operated calcium entry. Cyanidin-3-glucoside significantly inhibited the ATP-induced [$Ca^{2+}$]i responses in the presence of nimodipine and ${\omega}$-conotoxin. Cyanidin-3-glucoside also significantly inhibited KCl (50 mM)-induced [$Ca^{2+}$]i increases. Cyanidin-3-glucoside significantly inhibited ATP-induced mitochondrial depolarization. The intracellular $Ca^{2+}$ chelator BAPTA-AM or the mitochondrial $Ca^{2+}$ uniporter inhibitor RU360 blocked the ATP-induced mitochondrial depolarization in the presence of cyanidin-3-glucoside. Cyanidin-3-glucoside blocked ATP-induced formation of ROS. BAPTA-AM further decreased the formation of ROS in the presence of cyanidin-3-glucoside. All these results suggest that cyanidin-3-glucoside inhibits ATP-induced calcium signaling in PC12 cells by inhibiting multiple pathways which are the influx of extracellular $Ca^{2+}$ through the nimodipine and ${\omega}$-conotoxin-sensitive and -insensitive pathways and the release of $Ca^{2+}$ from intracellular stores. In addition, cyanidin-3-glucoside inhibits ATP-induced formation of ROS by inhibiting $Ca^{2+}$-induced mitochondrial depolarization.

• International Journal of Oral Biology
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• v.33 no.1
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• pp.33-43
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• 2008

In the process of bone remodeling, mineral phase of bone is dissolved by osteoclasts, resulting in elevation of calcium concentration in micro-environment. This study was performed to explore the effect of high extracellular calcium ($Ca{^{2+}}_e$) on mineralized nodule formation and on the expression of progressive ankylosis (Ank), plasma cell membrane glycoprotein-1 (PC-1) and osteopontin by primary cultured mouse calvarial cells. Osteoblastic differentiation and mineralized nodule formation was induced by culture of mouse calvarial cells in osteoblast differentiation medium containing ascorbic acid and ${\beta}$-glycerophosphate. Although Ank, PC-1 and osteopontin are well known inhibitors of mineralization, expression of these genes were induced at the later stage of osteoblast differentiation during when expression of osteocalcin, a late marker gene of osteoblast differentiation, was induced and mineralization was actively progressing. High $Ca{^{2+}}_e$(10 mM) treatment highly enhanced mRNA expression of Ank, PC-1 and osteopontin in the late stage of osteoblast differentiation but not in the early stage. Inhibition of p44/42 MAPK activation but not that of protein kinase C suppressed high $Ca{^{2+}}_{e^-}$induced expression of Ank, PC-1 and osteopontin. When high $Ca{^{2+}}_e$(5 mM or 10 mM) was present in culture medium during when mineral deposition was actively progressing, matrix calcifiation was significantly increased by high $Ca{^{2+}}_e$. This stimulatory effect was abolished by pyrophosphate (5 mM) or levamisole (0.1-0.5 mM), an alkaline phosphatase inhibitor. In addition, probenecid (2mM), an inhibitor of Ank, suppressed matrix calcification in both control and high $Ca{^{2+}}_{e^-}$treated group, suggesting the possible role of Ank in matrix calcification by osteoblasts. Taken together, these results showed that high $Ca{^{2+}}_e$ stimulates expression of Ank, PC-1 and osteopontin as well as matrix calcification in late differentiation stage of osteoblasts and that p44/42 MAPK activation is involved in high $Ca{^{2+}}_{e^-}$induced expression of Ank, PC-1 and osteopontin.

• The Journal of Korean Society of Virology
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• v.30 no.1
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• pp.83-99
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• 2000

A defective HIV-1 helper virus DNA, pHyPC, was assembled by deleting the RNA packaging signal, env, nef and the 3'LTR sequences. HIV-1 like virus particles that carry the HIV-1 receptor, CD4 were generated by co expression of pHyPC and plasmid DNAs encoding different chimeric CD4 proteins. The CD4 particles, sharing the CD4 ectodomain, precisely fused to different membrane anchors. CD4(+) particles specifically bound to HIV-1 Env expressing cells, but any signs of infection into these cells were not detected. Binding was only partially blocked by either polyclonal anti-CD4 antibodies or by high concentrations of soluble CD4. Surprisingly, CD4(+) particles also adsorbed to HeLa, CHO, NIH3T3 and COS-7 cells in the absence of HIV-1 Env expression. Adsorption was comparable in strength and speed to the highly specific CD4-Env interaction. CD4(-) particles exhibited only background levels of binding. Cell binding was CD4. dependent, but it was independent of the cell type from which the CD4(+) particles originated. Interestingly, CD4-dependent/Env-independent binding was only found when CD4 was present on virus particles. This suggests that the micro-environment of CD4 on virus particles uniquely expose this new cell binding activity. Its high affinity could explain in part why infection of Env(+) cells by CD4(+) particles was not detected. Further experiments will be required to evaluate whether this strong membrane interaction could represent one step in the multiple-step viral entry process.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1309-1314
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• 2003

We examined the effects of Oak Smoke Flavoring (OSF, Holyessing) on the cell proliferation of DU145 and PC3 human prostate carcinoma cell line. OSF treatment resulted in a concentration-dependent inhibition of the cell viability in both DU145 and PC3 cell lines. The anti-proliferative effects by OSF treatment in DU145 and PC3 cells were associated with morphological changes such as membrane shrinking and cell rounding up. DNA flow cytometric histograms showed that population of S phase of the cell cycle was increased by OSF treatment in a dose-dependent manner. Western blot analysis revealed that cyclin B1 and cdc2 proteins were reduced by OSF treatment in DU145 cells, whereas cyclin A was markedly inhibited in PC3 cells. Furthermore, we observed an increase of Cdk inhibitor p16 and p27 protein, and an inhibition of phosphorylation of pRB by OSF treatment in a dose-dependent manner. The present results indicated that OSF-induced inhibition of human prostate carcinoma cell proliferation is associated with the blockage of S phase progression.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.785-791
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• 2014

Crude extracts or phytochemicals obtained from some plants have potential anti-cancer properties. Teucrium persicum is an Iranian endemic plant belonging to the Lamiaceae family which has traditionally been used to relieve abdominal pains. However, the anti-cancer properties of this species of the Teucrium genus have not been investigated previously. In this study, we have used a highly invasive prostate cancer cell line, PC-3, which is an appropriate cell system to study anti-tumor properties of plants. A methanolic extract obtained from T persicum potently inhibited viability of PC-3 cells. The viability of SW480 colon and T47D breast cancer cells was also significantly decreased in the presence of the T persicum extract. Flow cytometry suggested that the reduction of cell viability was due to induction of apoptosis. In addition, the results of wound healing and gelatin zymography experiments supported anti-cell invasion activity of T persicum. Interestingly, sublethal concentrations of T persicum extract induced an epithelial-like morphology in a subpopulation of cells with an increase in E-Cadherin and ${\beta}$-Catenin protein levels at the cell membrane. These results strongly suggest that T persicum is a plant with very potent anti-tumor activity.

• Journal of Nutrition and Health
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• v.29 no.2
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• pp.192-198
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• 1996

This experiment was conducted to examine the effects of fish oil supplementation with low does on the lipid concentration and fatty acid composition of plasma and the fatty acid composition of plasma phospholipid and erythrocyte of infants. Among 18 breast-fed infants, 6 were in control group and 12 were in fish oil groups. The subjects in fish oil groups were nursed by their mothers who supplemented with fish oil 1.96g/d or 3.92g/d, respectively for 2 weeks from 10 to 12 weeks postpartum. The nursing mothers consumed their usual diets at home. Blood samples were collected at the final day of experiment. There were no significant changes in daily intakes of total lipid, triglyceride, free fatty acid, phospholipid and cholesterol of infants by fish oil supplementation. However, the content of EPA (eicosapentaenoic acid)increased and that of ARA (arachidonic acid) decreaed significantly in plasma PC(phophatidylchline). And also, there were tendencies to increase triglyceride concentration and to decrease cholesterol and phopholipid concentrations of plasma. As the above results, atherogenic index (AI) showed a tendency to decrease, but not significant. DHA (docosahexaenoic acid) and EPA contents in plasma PC and PE (phosphatidylethanolamin) as well as those of erythrocyte tended to increase. In these results, we concluded that fish oil supplementation with low dose to lactating women does not obviously affect of the plasma lipid concentrations and fatty acid composition of plasma PC and PE as well as erythrocyte. However the increase of EPA content of plasma PC and the tendency to increase DHA and EPA contents of plasma as well as erythrocyte membrane indicate that there may be some beneficial effect on infant lipid metabolism of fish oil intake of nutsing mother were increased.

• Journal of Ginseng Research
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• v.45 no.4
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• pp.473-481
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• 2021

Background: Mitochondrial dysfunction is one of the significant reasons for Alzheimer's disease (AD). Ginsenosides, natural molecules extracted from Panax ginseng, have been demonstrated to exert essential neuroprotective functions, which can ascribe to its anti-oxidative effect, enhancing central metabolism and improving mitochondrial function. However, a comprehensive analysis of cellular mitochondrial bioenergetics after ginsenoside treatment under Aβ-oxidative stress is missing. Methods: The antioxidant activities of ginsenoside Rb₁, Rd, Re, Rg₁ were compared by measuring the cell survival and reactive oxygen species (ROS) formation. Next, the protective effects of ginsenosides of mitochondrial bioenergetics were examined by measuring oxygen consumption rate (OCR) in PC12 cells under Aβ-oxidative stress with an extracellular flux analyzer. Meanwhile, mitochondrial membrane potential (MMP) and mitochondrial dynamics were evaluated by confocal laser scanning microscopy. Results: Ginsenoside Rg₁ possessed the strongest anti-oxidative property, and which therefore provided the best protective function to PC12 cells under the Aβ oxidative stress by increasing ATP production to 3 folds, spare capacity to 2 folds, maximal respiration to 2 folds and non-mitochondrial respiration to 1.5 folds, as compared to Aβ cell model. Furthermore, ginsenoside Rg1 enhanced MMP and mitochondrial interconnectivity, and simultaneously reduced mitochondrial circularity. Conclusion: In the present study, these results demonstrated that ginsenoside Rg₁ could be the best natural compound, as compared with other ginsenosides, by modulating the OCR of cultured PC12 cells during oxidative phosphorylation, in regulating MMP and in improving mitochondria dynamics under Aβ-induced oxidative stress.

• Interaction and multiscale mechanics
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• v.2 no.1
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• pp.69-89
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• 2009

Reinforced and prestressed concrete (RC and PC) thin walls are crucial to the safety and serviceability of structures subjected to shear. The shear strengths of elements in walls depend strongly on the softening of concrete struts in the principal compression direction due to the principal tension in the perpendicular direction. The past three decades have seen a rapid development of knowledge in shear of reinforced concrete structures. Various rational models have been proposed that are based on the smeared-crack concept and can satisfy Navier's three principles of mechanics of materials (i.e., stress equilibrium, strain compatibility and constitutive laws). The Cyclic Softened Membrane Model (CSMM) is one such rational model developed at the University of Houston, which is being efficiently used to predict the behavior of RC/PC structures critical in shear. CSMM for RC has already been implemented into finite element framework of OpenSees (Fenves 2005) to come up with a finite element program called Simulation of Reinforced Concrete Structures (SRCS) (Zhong 2005, Mo et al. 2008). CSMM for PC is being currently implemented into SRCS to make the program applicable to reinforced as well as prestressed concrete. The generalized program is called Simulation of Concrete Structures (SCS). In this paper, the CSMM for RC/PC in material scale is first introduced. Basically, the constitutive relationships of the materials, including uniaxial constitutive relationship of concrete, uniaxial constitutive relationships of reinforcements embedded in concrete and constitutive relationship of concrete in shear, are determined by testing RC/PC full-scale panels in a Universal Panel Tester available at the University of Houston. The formulation in element scale is then derived, including equilibrium and compatibility equations, relationship between biaxial strains and uniaxial strains, material stiffness matrix and RC plane stress element. Finally the formulated results with RC/PC plane stress elements are implemented in structure scale into a finite element program based on the framework of OpenSees to predict the structural behavior of RC/PC thin-walled structures subjected to earthquake-type loading. The accuracy of the multiscale modeling technique is validated by comparing the simulated responses of RC shear walls subjected to reversed cyclic loading and shake table excitations with test data. The response of a post tensioned precast column under reversed cyclic loads has also been simulated to check the accuracy of SCS which is currently under development. This multiscale modeling technique greatly improves the simulation capability of RC thin-walled structures available to researchers and engineers.