• The Korean Journal of Physiology
• /
• v.23 no.2
• /
• pp.351-361
• /
• 1989

The contraction of renal arterial strip by no.epineph.me (NE) or 40 mM $K^+$ were Significantly attenuated after histamine $(10^{-5}\;M)-induced$ contraction. The mechanisms of this phenomenon were investigated in the helical strips of isolated renal artery with the measurement of isometric tension. The arterial strip was immersed in the tris-buffered Tyrode's solution which was equilibrated with 100% $O_2\;at\;35^{\circ}C$. The contraction was induced by NE or 40 mM $K^+$ during the recovery from the histamine-induced contraction which lasted for 15 minutes. The contraction by NE was also attenuated in the $Ca^{2+}-free$ Tyrode's solution and the increase of contraction by addition of 2 mM $Ca^{2+}$ was attenuated as well. This attenuation phenomenon was not observed in the presence of low concentration $(3{\times}10^{-7}\;M)$ of histamine. This attenuation was not affected by destruction of endothelium, pretreatment with papaverine or propranolol. This attenuation was partially inhibited by pretreatment of ouabain or in low $K^+(0.5 mM)$ Tyrode's solution. But the attenuation in the $Ca^{2+}-free$ Tyrode's solution was not inhibited. Furthermore this attenuation was completely blocked by pretreatment of djphenhydramine $(H_1-receptor blocker)$ and potentiated by pretreatment of cimetidine $(H_2-receptor\;blocker)$. This attenuation Phenomenon was disappeared after recovery of 1 hour. From the above results, it is suggested that the attenuation phenomenon may be resulted partially from the activation of $Na^+-K^+$ exchange pump and partially from the depletion of intracellular $Ca^{2+}$ pool after the histamine-induced contraction mediated through $H_1-receptor$ function.

• Journal of Plant Biotechnology
• /
• v.39 no.3
• /
• pp.196-204
• /
• 2012

This study was carried out to develop reliable systems for somatic embryogenesis in oil palm tree (Elaeis guineensis Jacq.), and to verify the somaclonal variants by RAPD analysis. Embryogenic callus was induced successfully on modified half-strength MS medium containing $NaH_2PO_4{\cdot}2H_2O$ and casein. Embryogenic callus was further developed to somatic embryo mass (SEM), which is very hard and bonded tightly each other. Plantlets were proliferated when SEM was cultured on modified MS medium containing half strength $NH_4NO_3$, casein and L-ascorbic acid. Plantlets were transplanted into pots containing artificial soils. When RAPD analysis was conducted using randomly selected 95 in vitro plantlets and 19 random primers, somaclonal variation was detected using BNR35 primer. There was missing band around 1 kb in #22, #28, #35, and #77 plantlets. In addition, bands obtained from #28, #35, and #77 was much stronger than other normal bands. The blast results at NCBI revealed that somaclonal variation observed in this study was related to chloroplast genome of oil palm. The results also revealed that oil palm reproduction system through somatic embryogenesis is quite reliable and early detection of somaclonal variants seem to be possible at in vitro stage by RAPD analysis.

• Korean Journal of Pharmacognosy
• /
• v.37 no.4 s.147
• /
• pp.221-228
• /
• 2006

A lectin was purified from Serrognathus platymelus castanicolor larvae and named as SPL. The purification was carried out by ion-exchange chromatography on DEAE Sephadex A-50 and gel filtration chromatography on Sephadex G-200. The purity of the protein was verified by polyacrylamide gel electrophoresis and the purified lectin agglutinated erythrocytes of rabbit and human A, B, O, AB. SPL was tested it's ability to enhance the expressions of cytokines, $IL-1\alpha$, IL-2, IL-6, $TNF\alpha$ and $IFN\gamma$ by human peripheral blood mononuclear cells (PBMC) obtained from healthy donors. mRNA analyses were performed by RT-PCR at the moment of 1, 4, 8, 24, 48, 72 and 96 h after stimulation of PBMC with purified SPL. The patterns of IL-2 band were slightly expressed from 24 h and the strongest band was appeared at 96 h. The expressions of $IL-1\alpha$ and IL-6 mRNA were strong from 1 to 8 h and those of $TNF\alpha$ were from 48 to 96 h. The mRNA encoding $IFN\gamma$ were not detected. The addition of SPL for macrophage cultures induced production of nitric oxide (NO) by cells in a dose-dependent manner. NO release was partially inhibited by $TNF\alpha$ antibodies. These results suggest that SPL has the ability to enhance cytokine expressions in PBMC and to induce the NO release by TNFa in macrophage cultures from PBMC cultures.

• Korean Chemical Engineering Research
• /
• v.49 no.5
• /
• pp.633-638
• /
• 2011

Mn substituted La, Sr or Ba-hexaaluminate were prepared by $(NH_4)_2CO_3$ co-precipitate method and calcined at $1,200^{\circ}C$ for 5 h. Catalysts were characterized by X-ray diffraction and $N_2$ physisorption and scanning electron microscope (SEM). Compared to $SrMnAl_{11}O_{19}$ and $BaMnAl_{11}O_{19}$, $LaMnAl_{11}O_{19}$ in which La located at mirror plane showed better crystallinity and high surface area, 13 $m^2/g$. $LaMnAl_{11}O_{19}$ revealed well developed plate-like structure which is characteristic structure of hexaaluminate. The catalytic activity of methane combustion increased in the following order: $LaMnAl_{11}O_{19}$ > $SrMnAl_{11}O_{19}$ > $BaMnAl_{11}O_{19}$ and was dependent on surface area of catalysts. 60 wt% $CeO_2/LaMnAl_{11}O_{19}$ calcined at $700^{\circ}C$ showed enhanced methane activity and methane was oxidized completely at low temperature ($700^{\circ}C$). It was confirmed that addition of ceria seems to be effective for the low and middle temperature combustion of methane. But, after calcination at high temperature of $1,200^{\circ}C$, it lost the promoting effect of ceria due to increase of ceria particle size and it had a limit to applying to the high temperature catalytic combustion.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.4
• /
• pp.289-295
• /
• 2005

In this study, the cultural medium used for the efficient production of $\gamma$-PGA with a newly isolated Bacillus sp. RKY3 was optimized. It was necessary to supplement the culture medium with L-glutamic acid and an additional carbon source in order to induce the effective production of $\gamma$-PGA. The amount of $\gamma$-PGA increased with the addition of L-glutamic acid to the medium. The addition of 90 g/L L-glutamic acid to the medium resulted in the maximal yield of $\gamma$-PGA (83.2 g/L). The optimum nitrogen source was determined to be peptone, but corn steep liquor, a cheap nutrient, was also found to be effective for $\gamma$-PGA production. Both the $\gamma$-PGA production and cell growth increased rapidly with the addition of small amounts of $K_2HPO_4$ and $MgSO_4\cdot7H_{2}O$. Bacillus sp. RKY3 appears to require $Mg^{2+}$, rather than $Mn^{2+}$, for $\gamma$-PGA production, which is distinct from the production protocols associated with other, previously reported bacteria. Bacillus sp. RKY3 may also have contributed some minor $\gamma$-PGA depolymerase activity, resulting in the reduction of the molecular weight of the produced $\gamma$-PGA at the end of fermentation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.4
• /
• pp.587-592
• /
• 2006

This study was conducted to evaluate the effects of supplementation with bacillus-based probiotic (Bacillus subtilis, $1.0{\times}10^7CFU/g$; Bacillus coagulans, $2.0{\times}10^6CFU/g$ and Lactobacillus acidophilus, $5.0{\times}10^6CFU/g$) on finishing pigs growth performance, nutrients digestibility, blood characteristics and fecal noxious gas content and to determine the optimal addition level of this probiotic preparation. A total of forty eight pigs with an initial body weight (BW) of $90.60{\pm}2.94kg$ were allotted to three dietary treatments (four pigs per pen with four pens per treatment) according to a randomized complete block design. Dietary treatment included: 1) CON (basal diet); 2) BP1 (basal diet+bacillus-based probiotic 0.1%) and 3) BP2 (basal diet+bacillus-based probiotic 0.2%). The experiment lasted 6 weeks. Through the entire experimental period, ADG was improved by 11% (p<0.05) in pigs fed diets supplemented with 0.2% bacillus-based probiotic compared to pigs fed the basal diet. ADFI and gain/feed were not affected by the treatments (p>0.05). Supplementation of bacillus-based probiotic did not affect either DM and N digestibilities or blood characteristics (p>0.05) of pigs. Fecal ammonia nitrogen ($NH_3$-N) measured at the end of experiment was reduced (p<0.05) when pigs were fed the diet with 0.2% bacillus-based probiotic. Fecal butyric acid concentration also decreased significantly (p<0.05) whereas acetic acid and propionic acid concentrations were not affected (p>0.05) when pigs were fed diets with added bacillus-based probiotic. In conclusion, dietary supplementation of bacillus-based probiotic can increase growth performance and decrease fecal noxious gas content concentration.

• The Korean Journal of Zoology
• /
• v.29 no.2
• /
• pp.141-158
• /
• 1986

A glutathione peroxidase from white rat (Wistar strain)erythrocytes was partially purified and characterized. In addition, localization of this enzyme in the liver was studied by histochemical method. A glutathione peroxidase was purified approximately 33.5-folds by ammonium sulfate precipitation, Sephadex filtration column and DEAE-Sephadex column chromatography. The optimum temperature of the crude glutathione peroxidase was $40^\\circC$, and the optimum pH was 7.5. This crude glutathione peroxidase was most stable at $30^\\circC$ and the values of Km and Vmax were calculated to be 8.5mM and 15.6 $\\mu$moles/min for glutathione, and 40 $\\mu$M and 10.5 $\\mu$moles/min for hydrogen peroxide, respectively. The molecular weight of this enzyme was estimated by Sephadex G-200 gel filtration to be approximately 90, 000. By electron microscopic examination, histochemical reaction products were microbodies that were prominent in the peripheral parts of the lobule. The reaction products exhibited round shapes, the diameter of which varied $0.2\\sim0.7 \\muM$ and their boundary membranes were not distint.

• Applied Science and Convergence Technology
• /
• v.26 no.6
• /
• pp.218-222
• /
• 2017

This study was conducted to remove $NO_x$, which is the main cause of fine dust and air pollution as well as acid rain. $NO_x$ was tested using 3% NO (diluted in He) as a simulated gas. Experiments were sequentially carried out by oxidizing NO to $NO_2$ and absorbing $NO_2$. Especially, we focused on the changes of NO oxidation according to both oxidant ($NaClO_2$) concentration change (1~10 M) and oxidant pH change (pH = 1~5) by adding HCl. In addition, we tried to suggest a method to improve $NO_2$ absorption by conducting $NO_2$ reduction reaction with reducing agent (NaOH) concentration (40~60%). It was found that NO removal efficiency increased as both concentration of oxidant and flow rate of NO gas increased, and NO decreased more effectively as the pH of hydrochloric acid added to the oxidant was lower. The $NO_2$ adsorption was also better with increasing NaOH concentration, but the NO removal efficiency was ~20% lower than that of the selective NO reduction. Indeed, this experimental method is expected to be a new method that can be applied to the capture and removal of fine dust caused by air pollution because it is a method that can easily remove NO gas by a simple device without expensive giant equipment.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.11
• /
• pp.1507-1514
• /
• 2008

Cholesterol oxidase catalyses the conversion of cholesterol to 4-cholesten-3-one. This enzyme has been used for clinical assay of human serum cholesterol and for reduction of cholesterol level in foods and feeds. In order to search the microorganism which has a high extracellular and stable activity of cholesterol oxidase, soil microorganisms were screened. As a result, the one with the highest extracellular cholesterol oxidase activity was obtained and named as the BEN 115. The BEN 115 strain was identified as one of the Nocardia species based on our taxonomic studies. The cholesterol oxidase from this strain was shown to have two bands of extracellular proteins on SDS-PAGE and Western blot. Their molecular masses were estimated to be about 55 and 57 kDa, respectively. In addition, this cholesterol oxidase was considerably stable at the broad range of pH $3.5{\sim}9.5$ and at the temperature of $25{\sim}55^{\circ}C$. The optimum pH and temperature of this cholesterol oxidase were pH 5.5 and $35^{\circ}C$, respectively. The activity of extracellular cholesterol oxidase could be enhanced 1.6 to 2.0 folds by the addition of nonionic detergent such as Triton X-114, Triton X-100, or Tween-80 into the culturing broth. The substrate specificities against campesterol, sitosterol and stigmasterol were measured to be 50%, 50%, and 27%, respectively, compared to the cholesterol. These results suggest that Nocardia sp. BEN 115 may be useful as a microbial source of cholesterol oxidase production.

• Microbiology and Biotechnology Letters
• /
• v.17 no.3
• /
• pp.207-212
• /
• 1989

Cultural conditions for $\alpha$-D-Glucosidase Inhibitor production from Streptomyces sp. YS-221-B isolated from soil arid identified as Streptomyces flauovirens or a subspecies of it were investigated. When the strain was cultured in a flask containing 2% glucose, 0.3% asparagine, 0.0002% riboflavin, 0.05% $K_2$HPO$_4$, 0.1% MgSO$_4$.7$H_2O$, 0.05% NaCl, pH 8.0 at 3$0^{\circ}C$, maximum production of the inhibitor was obtained after 8-9 days of cultivation. Sugar alcohols such as mannitol, i-inositol, erythritol as carbon sources, asparagine and beef extract as nitrogen sources were favorable for inhibitor production. Among vitamins, riboflavin, p-aminobenzoic acid, pyridoxamine and folic acid promoted the production of inhibitor, but depressed by the addition of hesperidine, and also depressed by cobalt, lithium and ferrous salts.