• Title/Summary/Keyword: citrate buffer

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Ultrafiltration and Separation Process Optimization of Hen Egg White Lysozyme as Natural Antimicrobial Enzyme (천연 항균 효소제 난백 lysozyme의 한외여과 조건 최적화)

  • Lee, Eun-Young;Woo, Gun-Jo
    • Korean Journal of Food Science and Technology
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    • v.30 no.2
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    • pp.397-406
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    • 1998
  • Hen egg white lysozyme (HEWL) is very valuable as a natural preservative in food processing due to its selective bactericidal activity. HEWL which traditionally isolated by crystallization or freeze drying was simply separated from 13 different hen egg white (HEW) proteins by a single-step ultrafiltration. Freeze dried HEW (0.25%, w/v) dissolved in a citrate-phosphate buffer (pH 4.6) was ultrafiltered with a PM30 membrane under various operating conditions, by changing concentration, temperature, transmembrane pressure $({\triangle}P_T)$, and stirring speed. Optimum separation conditions were decided when maximal flux was obtained. Under the optimum separation conditions, the effect of membrane material and fouling on flux as time passed as well as lysozyme concentration, protein concentration, specific activity (SA) in the permeate were measured. Best separation conditions of HEWL with PM30 membrane were sample concentration 0.25%, temperature $35^{\circ}C$, ${\Delta}P_T\;30\;psi$, and stirring speed 300 rpm. During the first 12 min, the flux of YM30 was higher, but at the steady-state it was lower than that of PM30. The SA of the PM30 permeate was over 2 times higher in spite of the lysozyme and protein concentration being lower than that of YM30 permeate. The flux of 5 times used PM30 decreased 30% compared to a new PM30, but both had the same tendency in flux decrease when time passed. Both of them reached a steady-state after 35 min and remained at 70% of the initial flux. In the PM30 permeate, the lysozyme concentration and SA were 110 units/mL and 2,821 units/mg protein, respectively. Therefore, PM30 membrane separation was very effective for separation of antimicrobial lysozyme.

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Effect of Heat Treatment and Antibiotics on the Growth of Cellulomonas sp. KL-6 (Cellulomonas sp. KL-6의 증식에 미치는 열처리 및 항생물질의 효과)

  • Kwon, Oh-Jin;Chung, Yung-Gun
    • Applied Biological Chemistry
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    • v.37 no.4
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    • pp.221-225
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    • 1994
  • For producing single cell protein from the agricultural waste, heat treatment and antibiotics on the growth of Cellulomonas sp. KL-6, isolated in rotting leaf and the adjacent soil mixture, were examined. The organism was able to grow until 5 min. at $65^{\circ}C$, 1 min. at $75^{\circ}C$ and 1/4 min. at $85^{\circ}C$ in gradually rising temperatures. It can be Seen that preheating the suspension at $48^{\circ}C$ results in a marked decrease in heat resistance. On heating at temperature of $55^{\circ}C$ for 30 min., strain KL-6 was more resisted in the 0.1 M phosphate buffer when such substrates as casamino acid (1%), yeast extract (1%) or xylose (5%) were added to it whereas this organism was appeared weaker resistances in 0.1 M phosphate buffer when cysteine (0.03 M), sodium citrate (1%) or casein (1%) were in fused into it. Test strain was susceptible to penicillin-G $(1.563\;{\mu}g/ml)$ and ampicillin $(3.125\;{\mu}g/ml)$, but the organism was resisted to kanamycin $(>200\;{\mu}g/ml)$. The treatment of strain KL-6 with sodium dodecyl sulfate (SDS) resulted in the elimination of R-plasmid from the host strain and the elimination rate with SDS $(10{\sim}30\;{\mu}g/ml)$ was about $9.2{\sim}31.2%$, respectively.

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Correlation between Cyclin D1, p53, Bcl-2 Protein Expression and Prognosis in Primary, Resected Stage IIIA Non-Small Cell Lung Cancer (NSCLC) (완전 절제된 제IIIA기 비소세포폐암에서 Cyclin D1, p53, Bcl-2 단백질 발현의 의의)

  • 정경영;양우익
    • Journal of Chest Surgery
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    • v.31 no.12
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    • pp.1200-1205
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    • 1998
  • Background: Lung cancer formation is a multistage process involving activation of protooncogene and inactivation of tumor suppressor genes. We evaluate the significance of cyclin D1, p53, bcl-2 gene mutations in patients with curatively resected stage IIIA non-small cell lung cancer(NSCLC). Material and Method: One hundred consecutive cases of stage IIIA lung cancers from patients operated on curatvely between 1990 and 1995 for which adequate paraffin blocks and clinical history were available. Immunohistochemical studies were performed on the representative tissue sections from each case by the labelled streptovidin- biotin method. Sections for cyclin D1, p53, Bcl-2 immunostaining were pretreated in a microwave oven for 10 to 20 minutes in citrate buffer before immunostaining. The overnight incubation with NCL-cyclin D1-GM for cyclin D1, with clone DO-7 for p53, with clone 124 for bcl-2 was done. Mean follow-up was 24.1 months (range 2-84 months) after operation. Result: One hundred cases of lung cancers were composed of 56 cases of squamous cell carcinoma, 37 cases of adenocarcinoma, 5 cases of adenosquamous cell carcinoma, and 2 cases of large cell carcinoma. The 5-year survival was 32.1%. The positive expression rate of cyclin D1 was 35%, p53 was 56%, and bcl-2 was 17%. But there were no correlation between cyclin D1, p53, Bcl-2 protein expression and survival. Conclusion: These observation indicate that cyclin D1, p53, bcl-2 protein overexpression might be implicated in the oncogenesis of non-small cell lung carcinomas but they have no usefulness as a prognostic marker.

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Determination of Aldehydes in Tap Water by Reverse Phase Liquid Chromatography (역상 액체 크로마토그래피에 의한 수도수 중 알데하이드류의 정량)

  • Choi, Yong Wook;Choi, Yun Jung
    • Journal of the Korean Chemical Society
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    • v.43 no.4
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    • pp.438-446
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    • 1999
  • The optimum analytical method of aldehydes, ozone by-products, was established by reverse phase liquid chromatography. Six aldehydes including formaldehyde, acetaldehyde, acrolein, propionaldehyde, butylaldehyde and benzaldehyde, and one ketone including acetone were selected as aldehyde test samples through preliminary experiments. Such analytical conditions as the pH of citrate buffer solution, reaction temperature, reaction time, and concentration of DNPH, the component and composition of desorption solvent were optimized. As the result, pH 3.0 of citrate buffer solution, 40$^{\circ}C$ of reaction temperature, 15 minutes of reaction time, and 0.012% of DNPH concentration were chosen as optimum conditions. Aldehydes-DNPH derivatives in water were concentrated on $C_18$ Sep-Pak cartridge and followed by elution of their derivatives fraction with THF/ACN(70/30) mixture, and showed recoveries of the range from 87 to 107%. Separation condition on Nova-Pak $C_18$ column with low pressure gradient elution from ACN/MeOH/water(30/10/60) of an initial condition to 80% ACN of a final condition was found to give a good resolution within 20 minutes of run time. 86% to 103% of recovery for aldehydes using this method was similar to that for aldehyde using EPA Method 554 which is ranged from 84% to 103%.

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Studies on Milk Protein of Korean Cattle I. Fractionation of Milk Protein on DEAE-Cellulose (한우유(韓牛乳)의 단백질(蛋白質)에 관(關)한 연구(硏究) 제(第)1보(報) DEAE-Cellulose에 의(依)한 한우유단백질(韓牛乳蛋白質)의 분별(分別))

  • Kim, Y.K.;Chang, J.I.
    • Korean Journal of Food Science and Technology
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    • v.6 no.2
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    • pp.75-78
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    • 1974
  • An experiment has been carried out in order to analyze the main components of Korean Cattles' milk, and fractionate the milk protein by DEAE-cellulose column. The results obtained were summarized as follow. 1) The average values of specific gravity, pH and acidity of Korean Cattles milk which were negative in alcohol test were 1,036, 6.4 and 0.21, respectively. 2) The average values of total solids, solids-not-fat, protein, lactose and ash contents of Korean Cattles milk were 11.61%, 9.53%, 2.08%, 3.99%, 4.76% and 0.86%, respectively. 3) Distribution of casein, whey protein, N.P.N., protein precipitated in 12% TCA, lactoglobulin and lactalbumin contents of the milk were 3.07%, 1.13%, 0.10%, 4.06%, 0.34% and 0.66%, respectively. 4) Acid casein obtained from Korean Cattles milk was fractionated into four fractions on DEAE-cellulose column with 0.005M tris-citrate buffer containing 6M urea, pH 8.6, and the ratio of the fraction I, II, III and IV was 3.24%, 52.67%, 26.22% and 17.87%, respectively. 5) Whey protein obtained from Korean Cattles milk was also fractionated into four fractions on DEAE-cellulose column with 0.04M phosphate buffer, pH 5.8, and the ratio of the fraction I, II, III and IV was 41.74%, 10.17%, 1.50% and 46.59%, respectively.

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An Electron Microscopic Study on the Main Sensory Trigeminal Nucleus in the Aging Rat Brain (노화된 흰쥐 뇌 삼차신경주감각핵에 관한 전자현미경적 연구)

  • Kim, Myung-Kook
    • Applied Microscopy
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    • v.25 no.1
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    • pp.1-14
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    • 1995
  • The purpose of this study was to investigate the main sensory trigeminal nucleus in the aging rat brain by means of electron microscope. Male Sprague-Dawley rats, two (control group) and thirty six (aging group) months of age, were used. These animals were sacrificed by perfusion fixation with 2.5% glutaraldehyde-2.0% paraformaldehyde (0.1M phosphate buffer, pH 7.4) under sodium pentobarbital. The objective area was punched out with a sharp-edged metal cylinder of 0.8 mm in diameter. These blocks of tissue were then washed in 0.1M phosphate buffer, postfixed in 2% osmium tetroxide, dehydrated in a graded series of ethyl alcohol, and embedded in Epon 812. Thin sections were cut with Super Nova ultramicrotome, pick up on grids and double stained with lead citrate and uranyl acetate, and observed in JEOL 100B electron microscope. The results were as follows: 1. In the control group, the neuronal cell body of the main sensory trigeminal nucleus was filled with nucleus, Golgi complex, Nissl substance, mitochondria, microfilaments and microtubules. However, few Nissl substances are seen in neuronal cell body. Axoaxonic synapse, axodendritic synapse, axosomatic synapse, axospinous synapse, myelinated and unmyelinated nerve fibers were well organized around cell bodies. Neurons with abnormal changes were not seen. 2. In the aging group, the neuronal cell body of the main sensory trigeminal nucleus contained large number of lipofuscin granules, dense body and swollen mitochondria. Terminal boutons contained glycogen, crystal-like vesicle and membranous indicating first signs of degeneration. The dendrites were found to be in synaptic contact with altered axon terminals. Frequently axons filled with dark axoplasn and splitted myelin sheath were noticed.

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Enantioseparation and Determination of Sibutramine in Pharmaceutical Formulations by Capillary Electrophoresis

  • Zhu, Hongmei;Wu, Enqi;Chen, Jianbo;Men, Chuvan;Jang, Yu-Seon;Kang, Won-Ku;Choi, Jung-Kap;Lee, Won-Jae;Kang, Jong-Seong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1496-1500
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    • 2010
  • Sibutramine enantiomers were separated successfully by capillary zone electrophoresis using substituted cyclodextrins as chiral selectors. The effects of cyclodextrin concentration, pH, voltage, buffer type, and electrolyte concentration on the migration time and resolution of enantiomers were examined. Separation of sibutramine enantiomers on an unmodified fused silica capillary (total length, 54 cm; effective length, 45 cm) was achieved using a mixed buffer of 20 mM phosphate/10 mM citrate containing either 5 mM methyl-${\beta}$-cyclodextrin (pH 4.3) or 5 mM carboxymethyl-${\beta}$-cyclodextrin (pH 6.5). Samples were injected with a pressure of 50 mbar for 5 s and were detected at a wavelength of 223 nm. The established method showed good precision and accuracy, with intra- and inter-day variations of less than 2.9 and 4.7%, respectively, and recoveries of 95.7 - 103.8%. The stability constants of (R)- and (S)-sibutramine demonstrated that the resolution of sibutramine enantiomers was attributable primarily to the difference in stability constants. When this optimized method was applied to the determination of sibutramine enantiomers in commercial drug formulations, it proved to be economical and convenient, affording sufficient accuracy, precision, and reproducibility as well as sensitivity and selectivity.

Effect of Bitter Melon on Plasma Blood Glucose and Cholesterol Levels in Streptozotocin Induced Diabetic Rats (당뇨 유발 흰쥐에서 여주열매 첨가 시 혈당과 콜레스테롤 수준에 미치는 영향)

  • Kim, Myung-Wha
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.6
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    • pp.704-712
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    • 2013
  • This study was designed to examine the effects of bitter melon (BM) on the plasma blood glucose and cholesterol levels in diabetic rats. Diabetes mellitus was induced in male Sprague-Dawley rats through an injection of streptozotocin (STZ) dissolved in a citrate buffer into the tail vein at a dose of 45 mg/kg of body weight. Sprague-Dawley rats were then fed for four weeks, with the experimental groups receiving a modified diet containing 5% or 10% powder derived from BM. The experimental groups were divided into 4 groups, consisting of the normal control group, STZ-control group and diabetic fed with BM 5% & 10% treated groups. The rats' body weight, blood glucose and cholesterol values were measured along with the hematocrit (Hct) values and aminotransferase activities. Body weight losses were observed in the diabetic groups, whereas the control rats gained weight. There were significant differences in kidney weight between the control group and the diabetic groups. The Hct levels of the diabetic BM-treated group were significantly higher than the STZ-control group. Aspartate aminotransferase activity was lower in the non-diabetic group compared to the diabetic experimental groups. Further, the blood glucose was significantly decreased in the 5% & 10% BM of the diabetic group. There were no significant difference in cholesterol levels among the diabetic groups. These results indicate that the supplementation of bitter melon may have a favorable influence on reducing the blood glucose level in STZ-induced diabetic rats.

Antidiabetic Effect of Glechoma hederacea LINNAEUS in Streptozotocin-Induced Diabetic Rats (Streptozotocin 유발 당뇨 흰쥐에 대한 금전초 추출물의 혈당 강하 효과)

  • Kim, Ok-Kyung
    • Korean Journal of Pharmacognosy
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    • v.35 no.4 s.139
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    • pp.300-308
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    • 2004
  • This study was done to investigate the antidiabetic effect of Glechoma hederacea LINNAEUS in Streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by intravenous injection of STZ at a dose of 45 mg/kg dissolved in citrate buffer. The methanol extract of Glechoma hederacea was orally administrated once a day for 6 days. The contents of serum glucose, triglyceride (TG), total cholesterol and Atherogenic Index (Al) were significantly decreased, but high density lipoprotein (HDL)-cholesterol and HDL-cholesterol/total cholesterol ratio (HTR) were significantly increased in Glechoma hederacea treated STZ-sample group compared to the those of STZ-control group. The content of hepatic lipid peroxide and activity of catalase were decreased, but content of glutathione as well as activities of glutathione-S-transferase and superoxide dismutase were increased in Glechoma hederacea treated STZ-sample group compared to the those of STZ-control group. The content of hepatic glycogen and activities of glucose-6-phosphate dehydrogenase, glucokinase were significantly increased, but activity of glucose-6-phosphatase was decreased in Glechoma hederacea treated STZ-sample group compared to the those of STZ-control group. These results indicated that methanol extract of Glechoma hederacea would have antidiabetic effect in STZ-induced diabetic rats.

$S^{35}$(1,2-dichloro vinyl) L-Cysteine의 소에 의(依)한 대사물(代謝物)의 분리(分離)

  • Kim, Jae-Uk
    • Applied Biological Chemistry
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    • v.2
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    • pp.36-39
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    • 1961
  • It has been ascertained that S-(1, 2-dichlorovinyl) L-cysteine (DCVC) is probably the toxic component in the trichloro-ethylene extracted soybean oil meal on the bovine. For the study of the metabolites of DCVC, the components with radioactive $S^{35}$-in the urine of the calf, to which $S^{35}$-DCVC was administrated, were separated using of cellulose powder with propanol-water (70:30 V/V) which is easily removable by evaporation. As the results followings were obtained: Peak 1, which shows fractions containing single $S^{35}$-radioactive components, whose Rf is 0.815 Peak 2, which shows fractions containing jingle $S^{35}$-radioactive component, whose Rf is 0.447 Peak 3, which shows fractions containing both $S^{35}$-radioactive components whose Rfs are 0.090 and 0.171 Peak 4, which shows fractions containing single $S^{35}$-radioactive component, whose Rf is 0.142. Peak 5, which shows fractions containing single $S^{35}$-radioactive component, whose Rf is 0.084. Besides these, two of small peak were obtained. Although, the resolving power of the cellulose powder column is not sufficient, it is applicable for the study of the components of metabolytes of DCVC conveniently with the rest of removable solvent easily. Also the components with radioactive $S^{35}$ in the feces of the calf were separated using citrate buffer gradient system of Moore and stein. As the results; three $S^{35}$-radioactive components were separated.

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