• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.328-335
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• 1996

Effects of hydrogen peroxide$(H_2O_2)$ on polyphenol oxidase (PPO) in Perillae Folium were investigated. The inactivation of this enzyme was dependent on $H_2O_2$ concentration. and the initial lag period was not shown. Preincubation of Perillae Folium PPO with $H_2O_2$ in the absence of a substrate resulted in rapid loss of enzymatic activity. The inactivation of PPO by $H_2O_2$ dependents temperature and pH. OH radical scavengers such as mannitol and sodium formate did not protect the enzyme against inactivation by $H_2O_2$. Substrate analogue such as phenylalanine protected the enzyme against inactivation by $H_2O_2$. and copper chelator such as sodium azide also protected the enzyme.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.1
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• pp.24-30
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• 2011

The anti-cancer effects of Angelica keiskei ethanol extract were evaluated in human breast cancer MDA-MB-231 cells. The concentrations of extract were 1, 2, 3, 4 and 5 mg/mL. Dose-dependent reductions in the number of cells with altered cell shape and pyknotic nuclei were observed at 48 h after treatments. MTT assay also exhibited a similar dose-dependent reduction in mitochondrial reductase activity (p<0.05), in particular, with a rapid reduction in the activity of the 5 mg/mL group. Analysis of cell death with propidium iodide (PI) staining revealed only a slight increase in cell death in the 5 mg/mL group. Analysis of bromodeoxyuridine (BrdU) incorporations also showed a dose-dependent reduction in cell proliferation (p<0.05). Finally, increases in total radical oxygen species (ROS) accumulation in cells, as revealed by DCF-DA staining, were observed in the treated groups in a similar dose-dependent fashion (p<0.05). These results indicate that Angelica keiskei ethanol extract exhibiting anti-cancer effects in MDA-MB-231 cells causes multiple changes in cell shape, enzyme activity, and ROS accumulation, thereby inducing cell death.

• Development and Reproduction
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• v.3 no.1
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• pp.87-93
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• 1999

The possible role of Na$^{+}$/H$^{+}$ antiporter in both the capacitation and the acrosome reaction (AR) was examined in mouse epididymal spermatozoa. Spontaneous acrosome reaction was inhibited by dimethyl amiloride (DMA), a specific inhibitor of Na$^{+}$/H$^{+}$ antiporter, with dose dependent manner. Follicular fluid- or A23l 87-induced acrosome reaction was not inhibited by DMA. It suggests that change in pH$_{i}$ by monovalent cation transport through the Na$^{+}$/H$^{+}$ antiporter is possibly engaged in the capacitation and that agonist- as well as A23l87-induced AR in capacitated sperm might be independent from the Na$^{+}$/H$^{+}$ antiporter. Conclusively, changes in pH$_{i}$ through the Na$^{+}$/H$^{+}$ antiporter might be important for sperm capacitation and it virtually occurs upstream of the $Ca^{2+}$ influx which precedes the acrosome reaction in mouse epididymal spermatozoa.pididymal spermatozoa.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1357-1364
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• 2000

Our study was performed to evaluate the effect of leaching parameters including the physicochemical characteristics and the fractionated composition of heavy metals on the release of heavy metals in fly ash discharged from MSWI. Leaching parameters such as pH, CEC, particle size, and exchangeable fraction among the fractional composition classified by sequential extraction procedure are considered. The leaching rate of heavy metal released by KSLT method is largely dependent on the pH of fly ash. The effect of pH on the release of heavy metals is different from elements. It appears that the leaching rate of cadmium and copper decreases with increasing pH, while lead and zinc increases at the condition of neutral or strong alkali condition, which suggests that the leaching of heavy metals are limited by the solubility. It is found that the effect of CEC is similarly to that of pH, $D_{10}$ among the particle size of fly ash is negative correlated with the concentration of heavy metals leached by KSLT method. In the case of exchangeable fraction, the leaching rate of heavy metals is linearly correlated with the exchangeable fraction for the fly ash below 40 meq/l00g of CEC, but not related out of the range.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.352-367
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• 1998

Intracellular pH (pHi) plays an important role in the regulation of cellular processes by influencing the acitivity of various enzymes in cells. Therefore, almost every type of mammalian cell possesses an ability to regulate its pHi. One of the most prominent mechanisms in the regulation of pHi is $Na^+/H^+$ exchanger. This exchanger has been known to be activated when cells are stimulated by the binding of agonist to the muscarinic receptors. Therefore, the aims of this study were to compare the rates of $H^+$ extrusion through $Na^+/H^+$ exchanger before and during muscarinic stimulation and to investigate the possible existence of $HCO_3^-$ transporter which is responsible for the continuous supply of $HCO_3^-$ ion to saliva. Acinar cells were isolated from the rat mandibular salivary glands and loaded with pH-sensitive fluoroprobe, 2', 7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein(BCECF), for 30min at room temperature. Cells were attached onto the coverglass in the perfusion chamber and the changes in pHi were measured on the iverted microscope using spectrofluorometer. 1. By switching the perfusate from $HCO_3^-$-free to $HCO_3^-$-buffered solution, pHi decreased by $0.39{\pm}0.02$ pH units followed by a slow increase at an initial rate of $0.04{\pm}0.007$ pH units/min. The rate of pHi increase was reduced to $0.01{\pm}0.002$ pH units/min by the simultaneous addition of 1 mM amiloride and $100{\mu}M$ DIDS. 2. An addition and removal of $NH_4^+$ caused a decrease in pHi which was followed by an increase in pHi. The increase of pHi was almost completely blocked by 1mM amiloride in $HCO_3^-$-free perfusate which implied that the pHi increase was entired dependent on the activation of $Na^+/H^+$ exchanger in $HCO_3^-$-free condition. 3. An addition of $10{\mu}M$ carbachol increased the initial rate of pHi recovery from $0.16{\pm}0.01$ pH units/min to $0.28{\pm}0.03pH$ units/min. 4. The initial rate of pHi decrease induced by 1mM amiloride was also increased by the exposure of the acinar cells to $10{\mu}M$ carbachol ($0.06{\pm}0.008pH$ unit/min) compared with that obtained before carbachol stimulation ($0.03{\pm}0.004pH$ unit/min). 5. The intracellular buffering capacity ${\beta}1$ was $14.31{\pm}1.82$ at pHi 7.2-7.4 and ${\beta}1$ increased as pHi decreased. 6. The rate of $H^+$ extrusion through $Na^+/H^+$ exchanger was greatly enhanced by the stimulation of the cells with $10{\mu}M$ carbachol and there was an alkaline shift in the activity of the exchanger. 7. An intrusion mechanism of $HCO_3^-$ was identified in rat mandibular salivary acinar cells. Taken all together, I observed 3-fold increase in $Na^+/H^+$ exchanger by the stimulation of the acinar cells with $10{\mu}M$ carbachol at pH 7.25. In addition, I have found an additional mechanism for the regulation of pHi which transported $HCO_3^-$ into the cells.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.618-625
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• 2009

The objective of this work was to study the direct effects of daidzein on steroidogenesis in cultured mouse Leydig cells. Adult mouse Leydig cells were purified by Percoll gradient centrifugation, and the cell purity was determined using a $3{\beta}$-hydroxysteroid dehydrogenase ($3{\beta}$-HSD) staining method. The purified Leydig cells were exposed to different concentrations ($10^{-7}$ M to $10^{-4}$ M) of daidzein for 24 h under basal and human chorionic gonadotropin (hCG)-stimulated conditions. The cell viability and testosterone production were determined, and the related mechanisms of daidzein action were also evaluated using the estrogen receptor antagonist ICI 182,780 and measuring the mRNA levels of steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), and $3{\beta}$-HSD-1 involved in testosterone biosynthesis. The results revealed that daidzein did not influence cell viability. Daidzein increased both basal and hCG-stimulated testosterone production in a dose-dependent manner, and this effect was statistically significant at concentrations of $10^{-5}$ M and $10^{-4}$ M daidzein (p<0.05). ICI 182,780 had no influence on daidzein action. RTPCR results revealed that $10^{-5}$ M and $10^{-4}$ M daidzein did not exert any obvious influence on the mRNA level of P450scc in Leydig cells. However, in the presence of hCG, these concentrations of daidzein significantly increased the StAR and $3{\beta}$-HSD-1 mRNA levels (p<0.05), but in the absence of hCG, only $10^{-5}$ M and $10^{-4}$ M daidzein up-regulated the StAR and $3{\beta}$-HSD-1 mRNA expression (p<0.05), respectively. These results suggest that daidzein has direct effect on Leydig cells. Daidzein-induced increase of testosterone production is probably not mediated by the estrogen receptor but correlates with the increased mRNA levels of StAR and $3{\beta}$-HSD-1.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.18-25
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• 1996

Power input in stirred vessel is especially important in the design of mixers, as well as the evaluation of mixing processes. A type of baffles in mechanically agitated vessels and power employed are major factors that determine the stirring efficiency in a large scale, multi-step processes. In the present study, power input in the totally baffled agitated vesseles was compared systematically in connection with several previous studies and adequate power input correlation was found to be : $Np_{(pitch)}=({\theta}/90^{\circ})Np_{(90^{\circ})}$ Power number correlation was dependent upon the distance of among the impeller in the agitated vesseles, as follows : $$Np=7.09(n_p)^{0.7}(\frac{b_(double)}{d})(\frac{H}{D})^{0.18}$$, $${n_p}^{0.7}(\frac{b_{(double)}}d)$$<2 $$Np=8.73\{(n_p)^{0.7}(\frac{b_{(double)}}{d})\}^{0.7}(\frac{H}{D})^{0.18}$$, $${n_p}^{0.7}(\frac{b_{(double)}}d)$$>2.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.82-89
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• 2009

Two in vitro experiments were conducted to examine the effects of propionate precursors in the dicarboxylic acid pathway on ruminal fermentatation characteristics, $CH_4$ production and degradation of feed by rumen microbes. Fumarate or malate as sodium salts (Exp. 1) or acid type (Exp. 2) were added to the culture solution (150 ml, 50% strained rumen fluid and 50% artificial saliva) to achieve final concentrations of 0, 8, 16 and 24 mM, and incubated anaerobically for 0, 1, 3, 6, 9 and 12 h at $39^{\circ}C$. For both experiments, two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were prepared in a nylon bag, and were placed in a bottle containing the culture solution. Addition of fumarate or malate in both sodium salt and acid form increased (p<0.0001) pH of culture solution at 3, 6, 9 and 12 h incubations. The pH (p<0.0001) and total volatile fatty acids (VFA, p<0.05) were enhanced by these precursors as sodium salt at 3, 6 and 9 h incubations, and pH (p<0.001) and total VFA (p<0.01) from fumarate or malate in acid form were enhanced at a late stage of fermentation (9 h and 12 h) as the addition level increased. pH was higher (p<0.001) for fumarate than for malate as sodium salt at 3 h and 6 h incubations. Propionate ($C_3$) proportion was increased (p<0.0001) but those of $C_2$ (p<0.05) and $C_4$ (p<0.01 - p<0.001) were reduced by the addition of sodium salt precursors from 3 h to 12 incubation times while both precursors in acid form enhanced (p<0.011 - p<0.0001) proportion of $C_3$ from 6h but reduced (p<0.018 - p<0.0005) $C_4$ proportion at incubation times of 1, 3, 9 and 12 h. Proportion of $C_3$ was increased (p<0.05 - p<0.0001) at all incubation times by both precursors as sodium salt while that of $C_3$ was increased (p<0.001) from 6h but $C_4$ proportion was decreased by both precursors in acid form as the addition level increased. Proportion of $C_3$ was higher (p<0.01 - p<0.001) for fumarate than malate as sodium salt from 6 h incubation but was higher for malate than fumarate in acid form at 9 h (p<0.05) and 12 h (p<0.01) incubation times. Increased levels (16 and 24 mM) of fumarate or malate as sodium salt (p<0.017) and both precursors in acid form (p<0.028) increased the total gas production, but no differences were found between precursors in both chemical types. Propionate precursors in both chemical types clearly reduced (p<0.0001 - p<0.0002) $CH_4$ production, and the reduction (p<0.001 - p<0.0001) was dose dependent as the addition level of precursors increased. The $CH_4$ generated was smaller (p<0.01 - p<0.0001) for fumarate than for malate in both chemical types. Addition of fumarate or malate as sodium type reduced (p<0.004) dry matter degradation while both precursors in both chemical types slightly increased neutral detergent fiber degradability of feed in the nylon bag.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.268-275
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• 2004

To investigate the potential application of the single-cell gel electrophoresis (SCGE) assay to carp as an aquatic pollution monitoring technique, gill, liver, and blood cells were isolated from carp exposed to a direct-acting mutagen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), or indirect mutagen, $benzo[\alpha]pyrene$ $(B[\alpha]P)$, then the DNA strand breakage was analyzed using the assay. Based on testing 5 different cell isolation methods and 6 electrophoretic conditions, the optimized assay conditions were found to be cell isolation by filter pressing and electrophoresis at a lower voltage and longer running time (at 0.4 V/cm for 40 min). In preliminary experiments, gill and liver cells isolated from carp exposed to MNNG in vitro exhibited DNA damage signals even with 0.5 ppb exposure, which is a much higher dose than previously reported. In the gill cells isolated from carp exposed to 0.01-0.5 ppm MNNG in vivo, significant dose-and time-dependent increases were observed in the tail for 4 days. As such, the linear correlation between the relative damage index (RDI) values and time for each dose based on the initial 48-h exposure appeared to provide effective criteria for the genotoxicity monitoring of direct-acting mutagenic pollution. In contrast, the in vivo exposure of carp to 0.25-1.0 ppm of $B[\alpha]P$ for 7 days resulted in dose-and time-dependent responses in the liver cells, in which 24-h delayed responses for metabolizing activation and gradual repair after 48 h were also observed. Thus, the negative-sloped linear correlation between the RDI and time at each dose based on the initial 48 h appeared to provide more effective criteria for the genotoxicity monitoring of indirect mutagenic pollution.

• Journal of Soil and Groundwater Environment
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• v.14 no.4
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• pp.23-32
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• 2009

The sorption of europium (Eu (III)) onto kaolinite and the influence of humic acids over a range of pH 3 ~ 11 has been studied by batch adsorption experiment (V/m = 250 : 1 mL/g, $C_{Eu(III)}\;=\;1\;{\times}\;10^{-5}\;mol/L$, $C_{HA}\;=\;5{\sim}50\;mg/L$, $P_{CO2}=10^{-3.5}\;atm$). The concentrations of HA and Eu(III) in aqueous phase were measured by UV absorbance at 254nm (e.g., $UV_{254}$) and ICP-MS after microwave digestion for HA removals, respectively. Results showed that the HA sorption onto kaolinite was decreased with increasing pH and their sorption isotherms fit well with the Langmuir adsorption model (except pH 3). Maximum amount ($q_{max}$) for the HA sorption at pH 4 to 11 was ranged from 4.73 to 0.47 mg/g. Europium adsorption onto the kaolinite in the absence of HA was typical, showing an increases with pH and a distinct adsorption edge at pH 3 to 5. However in the presence of HA, Eu adsorption to kaolinite was significantly affected. HA was shown to enhance Eu adsorption in the acidic pH range (pH 3 ~ 4) due to the formation of additional binding sites for Eu coming from HA adsorbed onto kaolinite surface, but reduce Eu adsorption in the intermediate and high pH above 6 due to the formation of aqueous Eu-HA complexes. The results on the ternary interaction of kaolinte-Eu-HA are compared with those on the binary system of kaolinite-HA and kaolinite-Eu and adsorption mechanism with pH was discussed.