• YAKHAK HOEJI
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• v.25 no.2
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• pp.57-64
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• 1981

The antihypertensive effect of $\alpha-Methyldopa$ administered concurrently with timolol or labetalol were studied with spontaneously hypertensive rats (SHR). Every drugs were administered orally once a day after prechecking the systolic blood pressure and heart rate of SHR. The blood pressure and heart rate of SHR were significantly decreased in groups of combination while those of non-combination groups were fallen slightly. Compared with control group, the significant changes of blood pressure was obseved in group of $\alpha-methyldopa$ with timolol(100mg+2mg/kg)and $\alpha-methyldopa$ with labetalol (100mg+12.5mg/kg). The group of $\alpha-methyldopa$ with timolo 1 (100mg + 1.0mg/kg) reduced blood Pressure in similar degree as manifested in group of $\alpha-methyldopa$ with labetalol (100mg + 50mg/kg). In the group that $\alpha-methyldopa$ was administered concurrently with timolol, the maximum antihypertensive effect and heart rate decreasing effect were appeared after 3hr and 1hr of administration respectively and those effects in group of $\alpha-methyldopa$ with labetalol were appeared after 6hr of administration. The acute oral toxicity test was performed using albino mice with $\alpha-methyldopa$ alone, $\alpha-methyldopa$ with timolol (100:1) and $\alpha-methyldopa$ with labetatol (4:1), and was found that the $LD_{50}$ of $\alpha-methyldopa$ alone was 1104 mg/kg, $\alpha-methyldopa$ with timolol (100:1) was 1115 mg/kg and $\alpha-methyldopa$ with labetalol (4:1) was 354mg/kg.

• Archives of Pharmacal Research
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• v.28 no.12
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• pp.1392-1399
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• 2005

This study evaluated the effect of $\alpha$-tocopherol ($\alpha$-TC), ischemic preconditioning (IPC) or a combination on the extent of mitochondrial injury caused by hepatic ischemia/reperfusion (I/R). Rats were pretreated with $\alpha$-TC (20 mg/kg per day, i.p.) for 3 days before sustained ischemia. A rat liver was preconditioned with 10 min of ischemia and 10 min of reperfusion, and was then subjected to 90 min of ischemia followed by 5 h or 24 h of reperfusion. I/R increased the aminotransferase activity and mitochondrial lipid peroxidation, whereas it decreased the mitochondrial glutamate dehydrogenase activity. $\alpha$-TC and IPC individually attenuated these changes. $\alpha$-TC combined with IPC ($\alpha$-TC+IPC) did not further attenuate the changes. The mitochondrial glutathione content decreased after 5 h reperfusion. This decrease was attenuated by $\alpha$-TC, IPC, and $\alpha$-TC+IPC. The significant production of peroxides observed after 10 min reperfusion subsequent to sustained ischemia was attenuated by $\alpha$-TC, IPC, and $\alpha$-TC+IPC. The mitochondria isolated after I/R were rapidly swollen. However, this swelling rate was reduced by $\alpha$­TC, IPC, and $\alpha$-TC+IPC. These results suggest that either $\alpha$-TC or IPC reduces the level of mitochondrial damage associated with oxidative stress caused by hepatic I/R, but $\alpha$- TC combined with IPC offers no significant additional protection.

• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.49-73
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• 1991

To elucidate enzymatic properties of $\alpha$-galactosidases (EC3, 2, 1, 22) from germinated soybean and Aspergillus niger changes in the enzyme activities and oligosaccharide contents during germination of soybean were determined and $\alpha$-galactosidases from germinated soybean and wheat bran culture of Aspergillus niger were purified by ammonium sulfate fractionation, ion exchange chromatography and gel filtration. Their chemical and enzymatic properties were investigated and the results obtained were summarized as follows : 1. $\alpha$-Galactosidase activity of soybean was maximized when it was germinated at $25^{\circ}C$ for 120 hours. And raffinose and stachyose in soybean were decomposed completely after 96 hours and 120 hours of germination, respectively. 2. The highest level of $\alpha$-Galactosidase activity was obtained when Aspergillus niger was grown on wheat bran medium at $30^{\circ}C$ for 96 hours. 3. Soybean $\alpha$-galactosidase was purified by 6.6 fold by ammonium slufate fractionation, ion exchange chromatography on DEAE-Cellulose and Sephadex A-50., and gel filtration on Sephadex G-150. Its specific activity was 825 units/mg protein and the yield was 2.5% of the total activity of crude extracts. 4. Aspergillus niger $\alpha$-galactosidase was purified by 23.7 fold. Its specific activity was 1,229 units/mg protein and the yield was 14% of the total activity of wheat bran culture. 5. The purified $\alpha$-galactosidases of soybean and Aspergillus niger were found to be homogeneous by polyacrylamide gel electrophoresis and by HPLC. 6. Chemical properties of the purified $\alpha$-galactosidases were : 1) The soybean $\alpha$-galactosidase was monomeric and its molecular weight was estimated to be 30,000 by SDS-PAGE whereas the Aspergillus niger $\alpha$-galactosidase was a tetrameric glycoprotein which consisted of identical subunits with molecular weight of 28,000 each.

• Kyungpook Mathematical Journal
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• v.48 no.4
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• pp.721-727
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• 2008

Let $W_{\alpha}$ be a weighted shift with positive weight sequence ${\alpha}=\{\alpha_i\}_{i=0}^{\infty}$. The semi-cubical hyponormality of $W_{\alpha}$ is introduced and some flatness properties of $W_{\alpha}$ are discussed in this note. In particular, it is proved that if ${\alpha}_n={\alpha}_{n+1}$ for some $n{\geq}1$, ${{\alpha}_{n+k}}={\alpha}_n$ for all $k{\geq}1$.

• YAKHAK HOEJI
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• v.30 no.3
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• pp.157-162
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• 1986

$\alpha$-Adrenoceptor subtypes in the isolated rat aortic strips were examined by using agonists and antagonists which have varying selectivity for $\alpha_1$- and $\alpha_2$- adrenoceptors. Norepinephrine and phenylephrine produced a similar magnitude of maximum contractions. $pA_2$ values for prazosin and yohimbine were not significantly different using norepinephrine or phenylephrine as the agonist, suggesting a single population of alpha-adrenoceptor. Contractile responses produced by alpha-agonists were antagonized more effectively by prazosin (approximately 1000 fold) than by yohimbine.

• Journal of Aquaculture
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• v.11 no.1
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• pp.119-124
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• 1998

The relative effectiveness of C21-steroids and human chorionic gonadotropin(HCG) on maturation and ovulatin was investigated in vitro using the isolated oocytes or ovarian fragments from the sea bass, Lateolabrax japonicus. ${\alpha}$-hydroxy, 20${\beta}$-dihydroprogesterone(17${\alpha}$20${\beta}$OHP : 5, 50, 500, 1000ng/ml), 17${\alpha}$-hydroxy, 20${\alpha}$-dihydroprogesterone(17${\alpha}$20${\alpha}$OHP : 5, 50, 500, 1000ng/ml) and HCG (5, 50, 500IU/ml) were effective in inducing oocyte maturation, GVM (germinal vesicle migration) or GVBD(germinal vesicle breakdown), compared to control except 17${\alpha}$20${\beta}$OHP and 17${\alpha}$20${\alpha}$OHP at 5ng/ml. 17${\alpha}$20${\beta}$OHP showed the greatest effect on oocyte maturation at 50ng/ml. A combination of 17${\alpha}$20${\beta}$OHP(50ng/ml) and HCG(500IU/ml) led to a significant increase (p<0.05) in GVBD when compared with 17${\alpha}$20${\beta}$OHP or HCG alone. These findings suggest that the two in combination acts synergistically to induce GVBD. 17${\alpha}$20${\beta}$OHP (1~1000ng/ml) and HCG(1~500IU/ml) also induced ovulation in ovarian fragments at all concentrations used ; more effective at lower concentrations(1~50ng/ml or IU/ml). It was shown that HCG was more potent in inducting ovulatin than 17${\alpha}$20${\beta}$OHP.

• The Korean Journal of Mycology
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• v.21 no.1
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• pp.23-27
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• 1993

Ion effects on $11{\alpha}-hydroxylation$ of progesterone and $5{\alpha}-reduction\;of\;11{\alpha}-hydroxyprogesterone$ by Rhizopus nigricans were investigated. Metal ions such as $Cu^{2+},\;Cd^{2+},\;Co^{2+},\;Mn^{2+},\;Zn^{2+},\;Fe^{2+},\;Mg^{2+},\;Fe^{3+}\;and\;Na^+$ reduced the $11{\alpha}-hydroxylation$ activity, while $K^+$ stimulated the same reaction. Enzyme activity for the $5{\alpha}-reduction$ of $11{\alpha}-hydroxyprogesterone$ was increased in the presence of $Fe^{2+},\;Mn^{2+},\;Mg^{2+},\;Co^{2+},\;Zn^{2+},\;Fe^{3+},\;K^+\;and\;Na^+$, whereas it was decreased in the presence of $Cd^{2+}\;and\;Cu^{2+}$. Potassium ion of $10^{-3}\;M\;$ of concentration was found to be effective for the promotion of $11{\alpha}-hydroxylation$. On the other hand, cadmium ion of $10^{-4}\;M$ was proved to suppress the $5{\alpha}-reduction$ reaction. Progesterone is reported to be transformed into $11{\alpha}-hydroxyprogesterone$ which, in turn, is converted further into $11{\alpha}-hydroxy-allopregnane-3$, 20-dione by R. nigricans. From this point of view, the highest yield of $11{\alpha}-hydroxyprogesterone$ could be obtained when potassium ion of $10^{-3}\;M$ was given initially followed by addition of cadmium ion of $10^{-4}\;M$ to limit conversion of 11{\alpha}-hydroxyprogesterone into $11{\alpha}-hydroxy-allopregnane-\;3$, 20-dione.

• Food Science of Animal Resources
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• v.22 no.2
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• pp.179-182
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• 2002

Using differential scanning calorimetry (DSC), changes underwent by a mixture of $\alpha$-lactalbumin ($\alpha$-La) and $\beta$-lactoglobulin ($\beta$-Lg) during heat treatment were studied, yielding useful information for the dairy industry. Results of the DSC showed that the heat denaturation temperature of the hobo-$\alpha$-La was higher than that of apo-$\alpha$-La, suggesting hole-$\alpha$-La‘s greater stability. The denaturation temperature of a mixture of holo-$\alpha$-La and $\beta$-Lg was also slightly lower than that of holo-$\alpha$-La alone. The denaturation temperature of an apo-$\alpha$-La and $\beta$-Lg mixture was higher than that of holo-$\alpha$-La and $\beta$-Lg, suggesting that the heat stability of apo-$\alpha$-La was increased by $\beta$-Lg. Based on these results, it is possible to conclude that a mixture of holo-$\alpha$-La and $\beta$-Lg is more intensively affected by an increase in temperature than other samples, and that free sulphydryl groups seem to take part in this heat-induced denaturation.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.483-489
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• 2002

The role of $G{\alpha}12\;and\;G{\alpha}13$ in modulating the IgE receptor-mediated histamine secretion in the streptolysin-o-permeabilized human cultured mast cell was investigated. The expression of $G{\alpha}12\;and\;G{\alpha}13$ proteins were regulated during human cultured mast cell differentiation, and a significant correlation was observed between the levels of expression of $G{\alpha}12\;and\;G{\alpha}13$ proteins and IgE receptor-mediated histamine secretion capability in human cultured mast cells. Antibodies against $G{\alpha}12\;and\;G{\alpha}13$ effectively inhibited the IgE receptor-induced histamine release, and the concentration of anti-$G{\alpha}12$ antibody used to inhibit histamine secretion was shown to also inhibit the IgE receptor-mediated elevation of intracellular $Ca^2+$. Therefore, the results suggest that $G{\alpha}12\;and\;G{\alpha}13$ play roles in modulating IgE receptor-activated $Ca^2+$ influx, thereby regulating histamine release in cultured human mast cells. This is the first report to show that $G{\alpha}12\;and\;G{\alpha}13$ are involved in the regulation of $Ca^2+$ mediated exocytosis in human cultured mast cells.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.296-302
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• 2012

A bacterial strain was isolated from soybean paste fermented in a Korean Buddhist temple as a producer of the extracellular thermostable ${\alpha}$-amylase. The isolate YB-1234 has been identified as Bacillus licheniformis on the basis of its 16S rDNA sequence, morphology and biochemical properties. A gene encoding the thermostable ${\alpha}$-amylase of B. licheniformis YB-1234 was cloned into Escherichia coli and its nucleotide sequence was determined. The deduced amino acid sequence of ${\alpha}$-amylase was very highly homologous to those of the thermostable ${\alpha}$-amylases of B. licheniformis belonging to the glycosyl hydrolase family 13. The ${\alpha}$-amylase produced by recombinant E. coli carrying the ${\alpha}$-amylase gene exhibited maximal activity at pH 6.0, identical to ${\alpha}$-amylase in the culture filtrate of B. licheniformis, while the temperature profile was somewhat different between the two. Particularly, ${\alpha}$-amylase produced from B. lcheniformis is much more thermostable than that from recombinant E. coli. The predominant products resulting from the ${\alpha}$-amylase hydrolysis were glucose, maltose and maltotriose for maltotetraose and maltohexaose.