• Journal of the korean society of oceanography
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• 제34권1호
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• pp.49-57
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• 1999

A red tide organism, Amphidinium carterae was incubated under different iron/chelator and nitrate concentrations to investigate the factors controlling the growth. The chelation capacity played a critical role in regulating the nitrate reductase (NR) activity and in vivo fluorescence of this organism. However, there was a significant difference between the NR activity and in vivo fluorescence in response to trace metals and chelator treatments. In vivo fluorescence was the highest in FeEDTA 10 ${\mu}$M treatments and the lowest in DTPA 10 ${\mu}$M treatments. This indicates that the availability of the trace metal is important in regulating the in vivo fluorescence of this photosynthetic microalgae In contrast, NR activity showed the highest values in trace metal enriched treatments, and trace metal + DTPA treatments showed fairly high NR activities. This suggests that DTPA treatment did not hinder the NR activity as much as it did in vivo fluorescence. In vivo fluorescence and NR activity increased with nitrate concentration of up to 50 ${\mu}$M and remained relatively constant or the rate of increase decreased above that concentration, indicating that initial nitrate concentration of higher than a certain level would not accelerate the growth of A. carterae. Further investigation is needed to elucidate the reason for the difference in timing sequence between the NR and in vivo fluorescence in response to different metal treatments and chelation capacity.

• Journal of Applied Biological Chemistry
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• 제55권4호
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• pp.263-266
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• 2012

면실박으로부터 단백질을 추출한 후 단백질 가수분해효소인 Flavourzyme으로 가수분해를 실시하여 면실박 단백질 가수분해물을 얻었고, 가수분해 정도는 trinitrobenzenesulfonic acid 방법과 Sodium dodecyl sulfate-polyacrylamide gel electrophoresis를 통해 측정하였다. 면실박 단백질 가수분해물은 한외여과에 의하여 3 kDa 이하로 cut-off하였고, Q-Sepharos fast flow, Sephadex G-15, reversed-phase high performance liquid chromatography를 이용하여 Fe, Ca-binding 펩타이드를 분리하였다. 그 결과 철분과 칼슘 결합력이 가장 높은 분획 51을 얻을 수 있었고, 이렇게 얻어진 Fe, Ca-binding 펩타이드는 향후 기능성 식품 소재로써 활용될 수 있다고 판단된다.

• BLOOD RESEARCH
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• 제53권4호
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• pp.314-319
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• 2018

Background Iron overload is a risk factor affecting all patients with thalassemia intermedia (TI). We aimed to determine whether there is a relationship of serum ferritin (SF) and alanine aminotransferase (ALT) with liver iron concentration (LIC) determined by R2 magnetic resonance imaging (R2-MRI), to estimate the most relevant degree of iron overload and best time to chelate in patients with TI. Methods In this cross-sectional study, 119 patients with TI (mean age years) were randomly selected and compared with 120 patients who had a diagnosis of thalassemia major (TM). Correlations of LIC, as determined by R2-MRI, with SF and ALT levels, were assessed in all participants. A P-value <0.05 was considered statistically significant. Results SF and LIC levels were lower in patients with TI than in those with TM; only ferritin values were significant. We found a statistically significant relationship between SF and LIC, with cut-off estimates of SF in patients with TI who had splenectomy and those who entered puberty spontaneously (916 and 940 ng/mL, respectively) with LIC >5 mg Fe/g dry weight (P<0.0001). A significant relationship was also found for patients with TI who had elevated ALT level (63.5 U/L), of 3.15 times the upper normal laboratory limit, using a cut-off for LIC ${\geq}5mg\;Fe/g\;dry\;weight$. Conclusion We determined the cut-off values for ALT and SF indicating the best time to start iron chelation therapy in patients with TI, and found significant correlations among iron overload, SF, and ALT.

• Journal of Dairy Science and Biotechnology
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• 제38권3호
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• pp.134-141
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• 2020

Oxidative stress is a cascade reaction characterized by a significant increase in the amount of oxidized components. Free radicals produced by oxidative stress are one of the common features in several experimental models of disease, and contribute to wide range of neurodegenerative diseases, including Alzheimer's disease. Iron (II) species can participate in the Fenton, and Fenton-like reactions, to react with hydrogen peroxide and generate hydroxyl radical. As iron accumulation and oxidative stress are associated with the pathological progression of neurodegenerative diseases, iron chelation and antioxidant therapies have become strategies to combat these diseases. Due to the complexity of the redox system in vivo, a multifaceted approach may be an attractive therapeutic strategy. Further investigations are highly expected for the prevention and treatment of neurodegenerative diseases in future.

• 대한임상검사과학회지
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• 제49권4호
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• pp.495-497
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• 2017

Thalassemia major is a genetic disorder with a defective synthesis of either the alpha or the beta chain of hemoglobin A. Blood transfusion is crucial for the survival in these patients. Unfortunately, endocrine dysfunction is a very common complication in these patients and is principally due to excessive iron overload as a result of frequent blood transfusions. Although regular blood transfusion may increase life expectancy, disturbances in growth and pubertal development, abnormal gonadal functions, impaired thyroid, parathyroid and adrenal functions, diabetes, and disorderly bone growth are common side effects. We hereby present a case of a 23-year-old, unmarried woman with beta thalassemia major presenting with primary amenorrhea, poor development of secondary sexual character, and short stature. Thorough history, clinical examination, and laboratory investigation, including dynamic function test (insulin tolerance test) were conducted. These tests confirmed that she had multiple endocrinopathies, including hypogonadotropic hypogonadism, growth hormone deficiency, and subclinical adrenal insufficiency, which were caused by iron overload. She required hormone replacement therapy. Early recognition of possible deficiencies in hypothalamo-pituitary-end organ hormones caused by iron overload in thalassemia patients that undergo frequent blood transfusion procedures is essential. Appropriate treatments, including transfusion regimen and chelation therapy, as well as specific treatment of each complication are the crucial for the successful management and improvement of quality of life these patients.

• Journal of Applied Biological Chemistry
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• 제53권3호
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• pp.174-178
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• 2010

탈지 미강으로부터 미강단백질을 추출하고 상업용 단백분해 효소로 가수분해하고 한외여과하여 얻어진 미강단백질 가수분해물을 Sephadex G-15로 분리하여 얻어진 peptide fraction에 칼슘, 철분을 binding하여 칼슘, 철분 함유 peptide를 제조하였다. 추출된 탈지 미강 단백질의 분자량은 10~66 kDa에 분포하고 있었다. 추출된 단백질을 Flavourzyme으로 가수분해 시, 최적 가수분해 시간은 6시간이었으며, 5kDa 이하로 한외여과 하여 얻어진 peptide를 Sephadex G-15로 분획한 결과 4개의 major peak를 얻었는데, 각 fraction의 칼슘, 철분을 binding한 결과 Ca/peptide는 FI에서, Fe/peptide는 F2에서 가장 많은 함량을 나타내었다. 본 연구 결과 얻어진 칼슘, 철분 binding peptide는 biomineral 기능성 식품의 소재로써 식품산업에 활용될 수 있다고 판단된다.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.651-661
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• 2019

Targeting the pathogen viability using drugs is associated with development of drug resistance due to selective pressure. Hence, there is an increased interest in developing agents that target bacterial virulence. In this study, the inhibitory effect of ciclopirox, an antifungal agent with iron chelation potential, on the microbial virulence factors was evaluated in 26 clinical MDR Pseudomonas aeruginosa isolates collected from Alexandria Main University Hospital, a tertiary hospital in Egypt. Treatment with 9 ㎍/ml ciclopirox inhibited the hemolytic activity in 70% isolates, reduced pyocyanin production, decreased protease secretion in 46% isolates, lowered twitching and swarming motility, and decreased biofilm formation by 1.5- to 4.5-fold. The quantitative real-time PCR analysis revealed that treatment with ciclopirox downregulated the expression levels of alkaline protease (aprA) and pyocyanin (phzA1). Ciclopirox is used to treat hematological malignancies and the systemic administration of ciclopirox is reported to have adequate oral absorption with a satisfactory drug safety profile. It is important to calculate the appropriate clinical dose and therapeutic index to reposition ciclopirox from a topical antifungal agent to a promising virulence-modifying agent agent against P. aeruginosa, a problematic Gram-negative pathogen.

• 한국축산식품학회지
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• 제33권2호
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• pp.170-180
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• 2013

This study was conducted to evaluate the antioxidant activity of oven-dried ($60^{\circ}C$) tomato powder (TP) as affected by water solubility and to evaluate the effects of TP on the physico-chemical properties, and antioxidant and antimicrobial activities of emulsified pork sausages with two levels of TP (1% and 2 %). After fresh tomatoes were homogenized and dried at $60^{\circ}C$ oven, they were extracted by stirring with water. Then, the aqueous solution was filtered, and water soluble and insoluble tomato powders were obtained with freeze drying. In experiment I, total phenolic contents in oven-dried tomato powder, water soluble and insoluble powder were more than 2 g/100 g. The radical scavenging activity and iron-chelation ability of the water-insoluble extracts were higher than those of dried TP and water-soluble extracts. In experiment II, pH values and Hunter L values of pork sausages formulated with TP were reduced. However, hunter a and b values were higher than those of the control, and those effects were increased with increased levels of TP. 2-Thiobarbituric acid reactive substance values of pork sausages containing TP were lower than that of the control during refrigerated storage, regardless of the TP level. These results indicated that TP could be used as a natural color agent and antioxidant in meat products without defects.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.905-909
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• 2010

Magnetic beads (Dynabeads$^{(R)}$) embedded in ~1 micron size polystyrene beads bearing surface carboxylic acid groups were modified with aminobenzyl ethylenediaminetetraacetic acid (ABEDTA) to concentrate or separate metal ions using pH gradients on micro and nano scales. The immobilization of ABEDTA was achieved by amide formation. The presence of the metal chelating functional group in the fully deprotonated form was confirmed by FT-IR. The chelation efficiency of beads was tested by determining metal ions in supernatant using GFAAS when pH gradients from 3 to 7. Mixtures of Cu and Mg and of Cd and Mn (at 10 ng/mL of metal) were separated as the difference in formation constant with the functional group of ABEDTA. The separation was repeated twice with relative standard deviation of <18%. A polydimethylsiloxane (PDMS) microchip column packed with EDTA-coated magnetic beads was optimized to concentrate metal ion for practical applications by eluting a Cu solution of micro scale at pH 3.

• Applied Biological Chemistry
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• 제18권4호
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• pp.194-202
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• 1975

이 연구(硏究)는 도시유기폐물(都市有機廢物)을 이용(利用)한 유기질비료(有機質肥料)로서 활성오니(活性汚泥) 및 진개퇴비(塵芥堆肥)를 킬레이트화 물질로서 利用(利用)하기 위(爲)해서 이들 물질(物質)의 특성(特性)을 조사(調査)하였다. 철(鐵)킬레이트화에 관여(關與)하는 수용성물질(水溶性物質)을 분자체 분획법(分劃法)으로 분리(分離)하여 자외선(紫外線)및 적외선분광(赤外線分光) 스펙트럼에 의해서 그 구조(構造)를 조사(調査)하였고 이들 킬레이트의 안정도상수(安定度常數)를 이온교환평형법(交換平衡法)으로 측정(測定)하여 이들을 킬레이트 물질로 사용(使用)하했을때 그 안정성(安定性)을 검사(檢討)하였다. 진개퇴비(塵芥堆肥)에서 추출(抽出)된 유기물질(有機物質)은 Sephadex G-25에 의(依)해 4개분획(個分劃)으로 분리(分離)되었고 이중 철(鐵)과 킬레이트를 이루고 있던 분획(分劃)은 분자량(分子量)이 $5000{\sim}10,000$ 사이에 있었고 Polyphenol구조(構造)의 산소군(酸素群)이 킬레이트화(化)에 관여(關與)하고 있었다. 활성오니중(活性汚泥中) 가용성(可溶性) 물질(物質)은 Sephadex G-25에 의(依)해 6개(個)의 분획(分劃)으로 분리(分離)되었고 이중 킬레이트를 이루고 있던 분획(分劃)은 $5000{\sim}10,000$ 또는 5000에 약간 미달(未達)하는 분자량(分子量)을 가지고 있고 Polypeptide의 amide기(基)가 킬레이트화에 관여(關與)하였다. 이들의 안정도상수(安定度常數)도 합성(合成)킬레이트 물질의 안정도상수(安定度常數)와 큰 차이(差異)가 없을 정도(程度)로 안정(安定)하였다.