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Lactoferrin Induces Tolerogenic Bone Marrow-Derived Dendritic Cells
박희원,Sun-Hee Park,Hyeon-Ju Jo,Tae-Gyu Kim,Jeong Hyun Lee,Seung-Goo Kang,장영생,김평현 대한면역학회 2020 Immune Network Vol.20 No.5
Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that initiate both T-cell responses and tolerance. Tolerogenic DCs (tDCs) are regulatory DCs that suppress immune responses through the induction of T-cell anergy and Tregs. Because lactoferrin (LF) was demonstrated to induce functional Tregs and has a protective effect against inflammatory bowel disease, we explored the tolerogenic effects of LF on mouse bone marrow-derived DCs (BMDCs). The expression of CD80/86 and MHC class II was diminished in LF-treated BMDCs (LF-BMDCs). LF facilitated BMDCs to suppress proliferation and elevate Foxp3+ induced Treg (iTreg) differentiation in ovalbumin-specific CD4+ T-cell culture. Foxp3 expression was further increased by blockade of the B7 molecule using CTLA4-Ig but was diminished by additional CD28 stimulation using anti-CD28 Ab. On the other hand, the levels of arginase-1 and indoleamine 2,3-dioxygenase-1 (known as key T-cell suppressive molecules) were increased in LF-BMDCs. Consistently, the suppressive activity of LF-BMDCs was partially restored by inhibitors of these molecules. Collectively, these results suggest that LF effectively causes DCs to be tolerogenic by both the suppression of T-cell proliferation and enhancement of iTreg differentiation. This tolerogenic effect of LF is due to the reduction of costimulatory molecules and enhancement of suppressive molecules.
HPLC를 이용한 농업용수, 논토양, 및 현미 중 metamifop의 잔류분석법 개발
박희원,문준관 한국농약과학회 2017 농약과학회지 Vol.21 No.1
An analytical method for detecting metamifop residue in paddy water, soil, and rice with high performance liquid chromatography (HPLC) was developed. Water was extracted with ethyl acetate before analyzing by HPLC. Soil residues were extracted with acetone under acidic condition and after purifying with Extrelut® NT, and silica SPE, the residue was analyzed by HPLC. For residue analysis in rice, the procedure involved extraction with acetone, purification with Extrelut® NT, partitioning between acetonitrile/hexane, purification with silica SPE cartridge, and analysis by HPLC. The limit of detection (LOD) was 1.0 ng, limit of quantitation (LOQ) was 3.0 ng, and method limit of quantitation (MLOQ) were 0.001 mg/L for paddy water, 0.01 mg/kg for rice and soil, respectively. Standard calibration curve shows linearity from 0.05 mg/kg to 5.0 mg/kg (R2 = 0.9999). The recoveries in fortified paddy water were 91.3 ± 3.5% (0.01 mg/L level) and 93.2 ± 6.3% (0.05 mg/L level). The recoveries in fortified paddy soils were 92.5 ± 4.0% (0.1 mg/kg level) and 92.7 ± 4.0% (0.5 mg/kg level) in soil A, while, 102.3 ± 4.4% (0.1 mg/kg level) and 98.9 ± 7.9% (0.5 mg/kg level) in soil B, respectively. The recoveries in fortified rice were 93.0 ± 6.9% (0.1 mg/kg level) and 85.0 ± 3.5% (0.5 mg/kg level). This method was proved to be effective and can be used to determine the metamifop residue in paddy water, paddy soil, and rice. 고성능 액체크로마토그래프(HPLC)를 이용한 농업용수, 논토양, 현미 중 잔류 metamifop을 분석하기 위한최적화한 추출법과 정제법을 조합하여 분석법을 개발하였다. 농업용수 중 잔류량은 ethyl acetate로 분배 추출, 논토양 중 잔류량은 아세톤으로 추출하고, Extrelut® NT 흡착 정제 후 실리카 SPE로 정제하여 HPLC로 분석하였다. 현미중 잔류량은 아세톤으로 추출하고, Extrelut® NT 흡착 정제과정과 acetonitrile/hexane 분배 후 실리카 SPE로 정제하여 HPLC로 분석하였다. 확립된 분석법의 검출 한계(limit of detection, LOD)는 1.0 ng이었고, 시료의 양을 고려한방법정량한계(method limit of quantitation, MLOQ)는 농업용수, 논토양과 현미 각각 0.001 mg/L, 0.01 mg/kg이었다. 표준검량선은 0.05 mg/kg 농도에서 5.0 mg/kg 범위까지 직선성을 보였고 (R2= 0.9999), 시료 중 회수율은 0.01, 0.05 mg/L 수준으로 첨가된 농업용수에서 각각 91.3 ± 3.5, 93.2 ± 6.3%이었다. 0.1, 0.5 mg/kg 수준으로 첨가한 A토양시료 중 회수율은 각각 92.5 ± 4.0, 92.7 ± 4.0%이었고, B토양시료 중 회수율은 102.3 ± 4.4, 98.9 ± 7.9%로 확인되었다. 또한, 0.1, 0.5 mg/kg 수준으로 첨가한 현미시료 중 회수율은 각각 93.0 ± 6.9, 85.0 ± 3.5%로 확립된 분석법은농업용수, 논토양, 그리고 현미중 잔류 metamifop의 분석에 적용할 수 있을 것이다.
척골운동신경전도검사에서 주관절 분절의 길이 측정에 미치는 줄자 두께의 영향
박희원,이호준,김상준,오병모,한태륜,백남종 대한근전도전기진단의학회 2008 대한근전도 전기진단의학회지 Vol.10 No.1
Objectives: We sometimes experience that a tapeline is partially folded in fully flexed elbow position, which may cause a considerable error in the measurement of across-elbow conduction velocity. This study is purposed to demonstrate the difference in distance measure of AE segment according to different widths of tapeline. Methods: We performed ulnar motor segmental conduction study with standard technique in twenty healthy subjects (average 29.8±6.35 years, male:female=13:7). Distance of AE segment was measured with three different widths (5 mm, 10 mm, 15 mm) of tapeline at two different elbow positions (90 degree and 135 degree of elbow flexion) by two separate examiners. Results: In 90 degree of elbow-flexion, distances of AE segment were 10.4±0.29, 10.7±0.34, and 10.9± 0.31 cm with 5-, 10- and 15 mm-width tapeline, which were significantly different (p<0.05). In 135 degree of elbow-flexion, distances of AE segment were 10.7±0.43, 11.0±0.45, and 11.4±0.53 cm with 5-, 10- and 15 mm-width tapeline, which were also significantly different (p<0.05). Conclusion: There is a room for considerable error (5~6%) in the measurement of AE conduction velocity according to width of a tapeline. Therefore width of a tapeline also should be considered for establishment of normative data in segmental ulnar motor conduction study.
박희원,박수경 한국정밀공학회 2013 International Journal of Precision Engineering and Vol.14 No.5
The role of push-off propulsion as a major source of energy generation to compensate for heel strike collisions has been emphasized analytically and experimentally. The predicted increase of push-off forces with gait speeds, however, may be physiologically limited by intrinsic muscle mechanics. In this study, we examined whether the contribution of push-off propulsion to step-to-step transition is restricted with gait speed. Seven healthy young subjects participated in over the ground walking experiments. Ground reaction forces (GRFs) were measured at four different gait speeds ranging from self-selected to the maximum gait speed. The results showed that the vertical push-off force showed saturation, whereas the horizontal push-off forces proportionally increased with speed. The configuration of the trailing leg showed greater forward leaning during faster gait trials, which increases the horizontal push-off force without a significant increase in the total push-off forces. In contrast, both vertical and horizontal heel strike forces increased with speed. The lack of energy supplied by push-off to counter the heel strike collision loss during the double support phase was followed by an increase in the GRF work during the single support phase. These results imply that the intrinsic muscle mechanics limit the compensatory increase in the push-off force against the heel strike collision loss at faster gait speeds, which then leads to changes in the leg configuration to guarantee horizontal propulsion so as to maintain a steady forward gait speed.