• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.191-208
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• 2024

The peptide-type hepatotoxins microcystins (MCs) and nodularin (NOD) are secondary metabolites produced by cyanobacteria. MCs and NOD can bioaccumulate in agricultural products through toxin-contaminated water, soil, and manure and can cause human health risks through the consumption of agricultural products. As interest in the contamination of agricultural products by MCs or NOD has recently emerged, occurrence studies based on various analysis methods for agricultural products have been conducted. However, studies on agricultural products are still insufficient compared to research on drinking water and seafood. In addition, research is primarily conducted on agricultural products grown in areas where green algae occur, but not on marketed products. In the present study, we review the physicochemical properties, toxicity, analysis methods, occurrence studies, and management status of MCs and NOD in agricultural products to build a foundation for systematic monitoring and safety management.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.2 s.30
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• pp.137-145
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• 1989

The purpose of this study was to investigate the effect of the permenent pleats finish on the cystine contents and the physical properties of wool fabrics. Monoethanolamine Sulfite (MEAS) was used as a reducing agent. Cystine contents of the fabrics were determined after the fabric was treated with various MEAS concentrations and steamset time. The cystine contents were increase as the MEAS concentrations were increased. The cystine contents were also increased with steamset time. As the settability showed close relationship with the cystine contents, breakdown and rebuilding of the cystine linkage was thought to play an important role for the settability. Physical properties such as shrink resistance, crease recovery angle and tensile strength were increased as the MEAS concentration was increased. As the stramset time was increased, shrink resistance and crease recovery angle were in creased.

• 대한예방의학회:학술대회논문집
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• 2002.10a
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• pp.463-463
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• 2002

• Analytical Science and Technology
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• v.13 no.3
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• pp.399-402
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• 2000

To determine the concentrations of microcystins present in lake water or in tap water using high performance liquid chromatography, it is necessary to concentrate a large volume of water samples (about 20 L) into very small volume (0.1-0.3 mL). Concentration can be conveniently done when disc type solid phase extraction (SPE) apparatus is used. Using this apparatus we have investigated the recovery rates of three kinds of microcystins, RR, YR, LR. The recovery rates were relatively low and the reproducibilities were not good either. It is expected, however, that the appropriate selection of the disc conditioning and eluting solvents and reproducible reconcentration process after SPE will improve both the recovery rates and the reproducibilities.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.11 no.1
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• pp.103-105
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• 2011

고호모시스틴혈증(hyperhomocysteinemia)은 호모시스테인과 메티오닌의 대사과정에 관여하는 여러 효소들의 결핍에 의해 발생할 수 있으며, 대표적인 효소 결핍으로는 cysthathione beta-synthase (CBS) 결핍증, Methionine synthase (MS) 결핍증, methylenetetrahydrofolate reductase (MTHFR) 결핍증이 있다. 이들은 고호모시스테인혈증을 보이나 임상증상, 메티오닌의 동반 상승, 거대적아구성빈혈, 메칠말로닌산뇨증등의 동반 여부등을 토대로 감별진단에 도움을 받을 수 있다. 본 연자는 뇌혈전증과 뇌졸중을 동반하는 고호모시스테인혈증의 원인으로 MTHFR 유전자의 돌연변이를 발견한 증례를 경험하였기에 이를 보고하는 바이다.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.169-175
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• 1996

The reactivity of the sulfhydryl (thiol) group of homocysteine has been associated with an Increased risk of atherosclerosis, thrombosis and stroke. Thiols also react with nitric oxide (NO, an endothelium-derived relaxing factor (EDRF) ), forming S-nitrosothiols that have been reported to have potent vasodilatory and antiplatelet effects and been expected to decrease adverse vascular effects of homocysteine. The present study was aimed to Investigate whether the S-nitrosation of homocysteine modulates the neurotoxic effects of homocysteine. An 18 hour-exposure of cultured rat cortical neurons to homocysteine ( >1 mM) resulted in a significant neuronal cell death. At comparable concentrations ( <10 mM), however, S-nitrosohomocysteine did not induce neuronal cell death. Furthermore, S-nitrosohomocysteirle partially blocked NMDA-mediated neurotoxicity. S-nitrosohomocysteine also decreased NMDA-mediated increases in intracellular calcium concentration. The present data indicate that in brain nitric oxide produced from neuronal and nonneuronal cells can modulate the potential, adverse properties of homocysteine.

• Monthly Duck's Village
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• s.114
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• pp.46-51
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• 2012

세계적으로 오리고기 생산량은 꾸준히 증가하고 있으며, 이에 따라 최적의 생산성을 이끌어 내기 위한 영양소 요구량 설정과 배합표 작성이 필요하다. 그러나 육지새와 물새의 해부학적, 생리학적, 대사적 차이점에도 불구하고 오리 연구 데이터가 희귀하다보니 오리사료 배합을 위해 육계의 자료를 참고하는 경우가 많다. 최근의 연구결과에 따르면 현재 오리 21일령까지 아미노산 권장수준은 라이신 1.16%, 메티오닌 0.76%, 메티오닌+시스틴 0.76%(Evonik, 2010)인데 이는 0~14일령 오리의 요구량에 가깝다. 15~35일령의 오리의 경우 증체를 위해서는 현 권장수준보다 다소 높은, 메티오닌 0.54%, 총 함황아미노산(TSAA) 0.84% 이상의 요구량을 필요로 할 것으로 보인다. 하지만 36~49일령 비육말기 오리 실험에서는 각각 0.35%, 0.59%로써 기존 추정량보다 낮은 것으로 나타났으며 35일령 이후에 보다 완만한 성장을 한 결과를 확인시켜주었다. 페킨종 오리의 생산성 향상을 위해서는 아미노산 요구량과 소화율에 대한 보다 심도 있고 추가적인 연구가 필요할 것이다.

• Journal of Nutrition and Health
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• v.42 no.5
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• pp.423-433
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• 2009

Folate and vitamin $B_{12}$ are essential cofactors for homocysteine (Hcy) metabolism. Homocysteinemia has been related with cardiovascular and neurodegenerative disease. We examined the effect of folate and/or vitamin $B_{12}$ deficiency on biomarkers of one carbon metabolism in blood, liver and brain, and analyzed the correlation between vitamin biomarkers in mild and moderate homocysteinemia. In this study, Sprague-Dawley male rats (5 groups, n = 10) were fed folatesufficient diet (FS), folate-deficient diet (FD) with 0 or 3 g homocystine (FSH and FDH), and folate-/vitamin $B_{12}$-deficient diet with 3 g homocystine (FDHCD) for 8 weeks. The FDH diet induced mild homocysteinemia (plasma Hcy 17.41 ${\pm}$ 1.94 nmol/mL) and the FDHCD diet induced moderate homocysteinemia (plasma Hcy 44.13 ${\pm}$ 2.65 nmol/mL), respectively. Although liver and brain folate levels were significantly lower compared with those values of rats fed FS or FSH (p < 0.001, p < 0.01 respectively), there were no significant differences in folate levels in liver and brain among the rats fed FD, FDH and FDHCD diet. However, rats fed FDHCD showed higher plasma folate levels (126.5 ${\pm}$ 9.6 nmol/L) compared with rats fed FD and FDH (21.1 ${\pm}$ 1.4 nmol/L, 22.0 ${\pm}$ 2.2 nmol/L)(p < 0.001), which is the feature of "ethyl-folate trap"by vitamin $B_{12}$ deficiency. Plasma Hcy was correlated with hepatic folate (r = -0.641, p < 0.01) but not with plasma folate or brain folate in this experimental condition. However, as we eliminated FDHCD group during correlation test, plasma Hcy was correlated with plasma folate (r = -0.581, p < 0.01), hepatic folate (r = -0.684, p < 0.01) and brain folate (r = -0.321, p < 0.05). Hepatic S-adenosylmethionine (SAM) level was lower in rats fed FD, FDH and FDHCD than in rats fed FS and FSH (p < 0.001, p < 0.001 respectively) and hepatic S-adenosylhomocysteine (SAH) level was significantly higher in those groups. The SAH level in brain was also significantly increased in rats fed FDHCD (p < 0.05). However, brain SAM level was not affected by folate and/or vitamin $B_{12}$ deficiency. This result suggests that dietary folate- and vitamin B12-deficiency may inhibit methylation in brain by increasing SAH rather than decreasing SAM level, which may be closely associated with impaired cognitive function in nutritional homocysteinemia.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.246-254
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• 2017

Microcystin-LR (MC-LR) is one of most abundant microcystins, and is derived from blue-green algae bloom. Advanced oxidation processes (AOPs) are effective process when high concentrations of MC-LR are released into a drinking water treatment system from surface water. In particular, UV-based AOPs such as UV, $UV/H_2O_2$, $UV/O_3$ and $UV/TiO_2$ have been studied for the removal of MC-LR. In this study, UV-LED was applied for the degradation of MC-LR because UV lamps have demonstrated some weaknesses, such as frequent replacements; that generate mercury waste and high heat loss. Degradation efficiencies of the MC-LR (initial conc. = $100{\mu}g/L$) were 30% and 95.9% using LED-L (280 nm, $0.024mW/cm^2$) and LED-H (280 nm, $2.18mW/cm^2$), respectively. Aromatic compounds of natural organic matter changed to aliphatic compounds under the LED-H irradiation by LC-OCD analysis. For application to raw water, the Nak-dong River was sampled during summer when blue-green algae were heavy bloom in 2016. The concentration of extracellular and total MC-LR, geosmin and 2-MIB slightly decreased by increasing the LED-L irradiation; however, the removal of MC-LR by UV-LED (${\lambda}=280nm$) was insufficient. Thus, advanced UV-LED technology or the addition of oxidants with UV-LED is required to obtain better degradation efficiency of MC-LR.

• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.745-752
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• 2005

Purpose : Adolescent obesity is known to be associated with complications such as hypertension, coronary artery disease and insulin resistance. We measured the common carotid artery by ultrasound as a predictor of atherosclerosis, and investigated the relationship between carotid artery parameters and serum cytokines in obese adolescents. Methods : Twenty-nine obese adolescents(16-17 years old, obesity index>130 percent) and twentyseven normal controls were included. Obesity index and body mass index were calculated from their height and weight. Skin fold thickness was measured at the triceps, and fat mass and fat distribution by bioelectrical impedence analysis. Blood pressure was measured at resting state and serum lipid, insulin, and homocysteine levels after a 12-hour fasting period. Intimal wall thickness, systolic and diastolic diameters of the common carotid artery were measured by ultrasound, and compliance and distensibility calculated by equation. Results : Systolic and diastolic diameters of the carotid artery significantly correlated with arm circumference, body mass index, fat distribution and fat mass. The higher systolic blood pressure was, the larger systolic and diastolic diameter. The higher diastolic blood pressure was, the larger carotid intimal thickness. Insulin levels had positive correlations with systolic, diastolic diameters and serum homocysteine level with intimal thickness. Conclusion : The carotid artery diameter significantly increased with the degree of obesity and blood pressure. The carotid intimal wall thickness significantly correlated with diastolic blood pressure. Measurement of carotid artery thickness, insulin and homocysteine levels might be useful to predict the development of coronary artery disease.