Modified Aloe Polysaccharide Restores Chronic Stress-Induced Immunosuppression in Mice

Lee, Youngjoo,Im, Sun-A,Kim, Jiyeon,Lee, Sungwon,Kwon, Junghak,Lee, Heetae,Kong, Hyunseok,Song, Youngcheon,Shin, Eunju,Do, Seon-Gil,Lee, Chong-Kil,Kim, Kyungjae MDPI 2016 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.17 No.10

<P>Chronic stress generally experienced in our daily lives; is known to augment disease vulnerability by suppressing the host immune system. In the present study; the effect of modified Aloe polysaccharide (MAP) on chronic stress-induced immunosuppression was studied; this Aloe compound was characterized in our earlier study. Mice were orally administered with MAP for 24 days and exposed to electric foot shock (EFS; duration; 3 min; interval; 10 s; intensity; 2 mA) for 17 days. The stress-related immunosuppression and restorative effect of MAP were then analyzed by measuring various immunological parameters. MAP treatment alleviated lymphoid atrophy and body weight loss. The numbers of lymphocyte subsets were significantly normalized in MAP-treated mice. Oral administration of MAP also restored the proliferative activities of lymphocytes; ovalbumin (OVA)-specific T cell proliferation; antibody production; and the cell killing activity of cytotoxic T lymphocytes. In summary; oral administration of MAP ameliorated chronic EFS stress-induced immunosuppression.</P>

LC-MS/MS를 이용한 Mecoprop 잔류분석법 확립

이정학 ( Junghak Lee ),이종화 ( Jonghwa Lee ),김은혜 ( Eunhye Kim ),신용호 ( Yongho Shin ),이지호 ( Jiho Lee ),정민우 ( Min Woo Jung ),백수진 ( Sujin Baek ),김정한 ( Jeong-han Kim ) 한국환경농학회 2016 한국환경농학회 학술대회집 Vol.2016 No.-

Mecoprop (MCPP)는 phenoxycarboxylic acid계 제초제로서 광엽잡초 방제에 쓰이는 농약이다. 본 연구에서는 LC-MS/MS를 이용하여 현미, 대두, 고추, 감귤, 감자에서의 mecoprop에 대한 잔류 분석법을 확립 하고자 하였다. 기기분석은 Shimadzu LC-MS 8040과 Kinetex C18 (2.1 × 100 mm, 2.6 μm)를 이용하였고, 이온화를 위하여 Electrospray Ionization negative mode에서 수행하였다. 확립된 전처리법으로 20 g의 분쇄된 시료에 이온억압을 위하여 1% 초산이 함유된 acetonitrile 100 mL로 10분간 추출하였다. salting-out을 위해 15 g의 NaCl를 첨가하여 10 분간 원심분리(3,000 rpm)하고, 상층액(유기용매 층) 20 mL를 감압농축 후 Ion-exchange Solid Phase Extraction (SPE, HLB)를 통해 정제하였다. 최종 잔류물을 질소 농축하여 1 mL의 methanol로 정용하고 matrix effect를 보정하기 위해 matrix matched calibration (1:1 희석)을 이용하여 확인하였다. 분석정량한계(MLOQ)는 5 ng/mL였고, 확립된 분석법의 검증을 위하여 무처리 시료에 각 표준용액을 1, 10, 50배의 3수준 3반복으로 처리하여 회수율을 산출하였다. 그 결과, 현미에서는 MLOQ, 10 MLOQ, 50 MLOQ에서 각각 107.9% ± 3.0, 79.1% ± 4.5, 95.9% ± 4.9였고, 대두에서 74.3% ± 6.3, 86.3 ± 3.3, 103.9% ± 2.3, 고추에서는 86.8% ± 5.8, 95.5% ± 3.2, 99.0% ± 6.4, 감귤은 85.2% ± 7.3, 87.1% ± 6.8, 103.7% ± 5.3, 감자는 85.1% ± 2.1, 102.8% ± 2.6, 94.1% ± 3.7 의 회수율을 확인하였다. 본 연구에서 확립한 방법은 농산물 중 mecoprop의 잔류분석으로 활용이 가능한 시험방법으로 판단된다.

Surgical Safety of Bilateral Axillo-Breast Approach Robotic Completion Thyroidectomy

JungHak Kwak,Su-Jin Kim,Zhen Xu,Keunchul Lee,Jong-hyuk Ahn,Hyeong Won Yu,Young Jun Chai,June Young Choi,Kyu Eun Lee 대한외과학회 2020 대한외과학회 학술대회 초록집 Vol.2020 No.11

A rapid, simultaneous and quantitative analysis of 26 ginsenosides in white and red Panax ginseng using LC–MS/MS

Lee Junghak,Han Heeju,Yuan Xiu,Park Eunyoung,Lee Jonghwa,Kim Jeong-Han 한국응용생명화학회 2021 Applied Biological Chemistry (Appl Biol Chem) Vol.64 No.1

A quantitative analysis of ginsenoside is very important for ginseng studies because each ginsenoside shows different medical activity and metabolic pathway. In this study, a rapid, simultaneous, and quantitative analysis of 26 ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg2(R), Rg2(S), Rg3(S), Rg3(R), Rg5, Rg6, Rh1(R), Rh1(S), Rh2(R), Rh2(S), F1, F2, F3, F4, K, Mc, PPT(S), XVII, and Y) in white, and red Panax ginseng was established using multiple reaction monitoring (MRM) mode on ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC–MS/MS). The mobile phase of water and methanol containing 0.1% formic acid and HSS T3 C18 analytical column was used for the chromatographic separation. The four sets of stereoisomers were successfully separated within a 26-min run time, eluting the S-isomer faster than the R-isomer with higher concentration. The ginseng extract was diluted by 100, 400 and 8000 times to fit in the calibration range and quantitated by the standard addition method. Matrix matched calibration by mixing 64 μL of the ginseng extract with 16 μL of the standard solution was used for compensating the matrix effect. Such quantitation methodology using dilution, standard addition and matrix matching resulted in precise and unambiguous quantitation of 26 ginsenosides in ginseng products. Major ginsenosides were observed at relatively higher concentrations in red Panax ginseng and the Mc was detected and quantitated for the first time in this study. The comprehensive quantitation system established in this study will contribute to quality evaluation, breeding and culturing, and quantitative metabolomics study of ginseng.

Rapid and Simultaneous Analysis of 360 Pesticides in Brown Rice, Spinach, Orange, and Potato Using Microbore GC-MS/MS

Lee, Jonghwa,Kim, Leesun,Shin, Yongho,Lee, Junghak,Lee, Jiho,Kim, Eunhye,Moon, Joon-Kwan,Kim, Jeong-Han American Chemical Society 2017 Journal of agricultural and food chemistry Vol.65 No.16

<P>A multiresidue method for the simultaneous and rapid analysis of 360 pesticides in representative agricultural produce (brown rice, orange, spinach, and potato) was developed using a modified QuEChERS procedure combined with gas chromatography tandem mass spectrometry (GC-MS/MS). Selected reaction monitoring transition parameters (e.g., collision energy, precursor and product ions) in MS/MS were optimized to achieve the best selectivity and sensitivity for a wide range of GC-amenable pesticides. A short (20 m) microbore (0.18 mm i.d.) column resulted in better signal-to-noise ratio with reduced analysis time than a conventional narrowbore column (30 m X 0.25 mm i.d.). The priming injection dramatically increased peak areas by masking effect on a new GC liner. The limit of quantitation was <0.01 mg/kg, and the correlation coefficients (r(2)) of matrix-matched standards were >0.99 within the range of 0.0025-0.1 mg/kg. Acetonitrile with 0.1% formic acid without additional buffer salts was used for pesticide extraction, whereas only primary secondary amine (PSA) was used for dispersive solid phase extraction (dSPE) cleanup, to achieve good recoveries for most of the target analytes. The recoveries ranged from 70 to 120% with relative standard deviations of <= 20% at 0.01 and 0.05 mg/kg spiking levels (n = 6) in all samples, indicating acceptable accuracy and precision of the method. Seventeen real samples from local markets were analyzed by using the optimized method, and 14 pesticides in 11 incurred samples were found at below the maximum residue limits.</P>

Clinical Outcomes of Partial Adrenalectomy in Bilateral Pheochromocytoma

JungHak Kwak,Sang Gab Yoon,Hyein Kang,Zhen Xu,Keunchul Lee,Jong-hyuk Ahn,Sung-Hye Kong,Hyeong Won Yu,Jung Hee Kim,Su-jin Kim,Young Jun Chai,June Young Choi,Moon-Woo Seong,Kyu Eun Lee 대한외과학회 2020 대한외과학회 학술대회 초록집 Vol.2020 No.11

Validation protocol for whole-body dosimetry in an agricultural exposure study

Lee, Jiho,Kim, Eunhye,Shin, Yongho,Lee, Jonghwa,Lee, Junghak,Maasfeld, Wolfgang,Kim, Jeong-Han The Korean Society for Applied Biological Chemistr 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.1

Agricultural workers exposed to pesticides can experience adverse health impacts depending on toxicity and exposure amount. Whole-body dosimetry (WBD) is the most reliable, practical, and realistic method for measuring exposure. Since validation of analytical and experimental methodologies is critical for quantitative determination of exposure, we conducted a validation procedure to design an essential protocol for WBD exposure studies. Using the fungicide kresoxim-methyl, matrixmatched standards were prepared with various matrices including outer cloth, inner cloth, washing solution for gloves and hands, gauze, and glass fiber filter (IOM sampler) to determine the instrumental limit of quantitation for high-performance liquid chromatography (HPLC) (2 ng) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) (10 pg). Method limits of quantitation (MLOQ) were also set for HPLC (0.1 mg/L) and LC-MS/MS (0.005 mg/L). We observed good analysis repeatability (coefficient of variation < 6%), and the linearity of the calibration curves was reasonable ($r^2$ > 0.998) in the range of 0.001-10 mg/L in various matrices. Recovery tests were carried out at three levels of concentration (MLOQ, 10 MLOQ, and 100 MLOQ) and resulted in good recoveries (72.7-105.6%). We did not observe breakthrough of the compound in tests of holding capacity for glass fiber pesticide filters. The procedures established in the present study are applicable as an essential, comprehensive protocol for exposure assessment studies using WBD.

Simultaneous analysis of 310 pesticide multiresidues using UHPLC-MS/MS in brown rice, orange, and spinach

Lee, Jonghwa,Shin, Yongho,Lee, Junghak,Lee, Jiho,Kim, Byung Joon,Kim, Jeong-Han Elsevier 2018 CHEMOSPHERE - Vol.207 No.-

<P><B>Abstract</B></P> <P>In this study, we developed a multiresidue method for the analysis of 310 pesticides in representative agricultural produce (brown rice, orange, and spinach) using ultra high performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) combined with a modified QuEChERS procedure. The optimal mobile phase composition (Methanol containing 5 mM ammonium formate and 0.1% formic acid) produced high sensitivity and reliable results. Also, the relationship between injection volume and repeatability of peak area was investigated. Most of the target pesticides had a limit of quantitation under 10 ng g<SUP>−1</SUP>, and correlation coefficients (<I>r</I> <SUP>2</SUP>) > 0.99 in matrix-matched standards within the range of 1–100 ng g<SUP>−1</SUP>. To validate the optimized method, recovery tests were performed with each of the crops at 10 and 50 ng g<SUP>−1</SUP> spiking levels (<I>n</I> = <I>5</I>). Satisfactory recoveries were achieved showing that 86.8–88.7% (at 10 ng g<SUP>−1</SUP>) and 91.9–96.1% (at 50 ng g<SUP>−1</SUP>) of the pesticides met the validation criteria (recoveries in the range of 70–120% and relative standard deviation ≤ 20%). Fifteen compounds were found to show a loss of recovery due to adsorption by primary and secondary amine or graphite carbon black. In the case of brown rice, 86.1% of pesticides showed an insignificant matrix effect (<±20%), while 35.2% and 41.6% of pesticides in orange and spinach were in that range, respectively. Sixteen apple samples from local markets were analyzed to evaluate the applicability of the optimized method. Nineteen pesticides were detected, of which the concentrations were lower than the maximum residue limit.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The protocol can analyze large number of pesticides (310 analytes) with modified QuEChERS and LC-MS/MS. </LI> <LI> A relationship between injection volumes and repeatability in LC-MS/MS analysis. </LI> <LI> Mobile phase compositions were compared for best sensitivity in LC-MS/MS. </LI> <LI> The method is reproducible and sensitive. </LI> <LI> It was successfully used to determine pesticide residues in market samples. </LI> </UL> </P>

어음청각검사용 한국어 기준음압의 표준화

이정학(Lee Junghak),김진숙(Kim Jinsook) 표준인증안전학회 2014 표준인증안전학회지 Vol.4 No.1

The reference sound pressure level (RSPL) for speech audiometry is established based on the speech recognition threshold (SRT) measured by standardized words and procedures (ISO 8253-3-2012). The aim of this study was to obtain the basic data for standardization of the reference sound pressure level (RSPL) for Korean speech audiometry which was defined as the reference speech recognition threshold level (RSRTL) regarding O dB HL at the audiometer. Subjects consisted of 230 adults with normal hearing sensitivity aged between 18 and 25 years from 5 universities. Puretone thresholds were obtained in 2 dB steps at each octave band. The newly developed Korean bisyllabic words were used for SRT test. SRTs were measured by the descending method described in ISO 8253-3 only at the better ear based on the PTA or right ear if PTAs were equal using 36 bisyllabic words which consist of 3 sets and each set has 12 test items. Retest of SRT was performed for the same subject about an hour after the first test. The RSPL was determined by the median of all subjects SRTs. Correlation analysis, paired t-test and confidence interval (CI) were used for test-retest reliability. Results suggest that the test-retest reliability of SRT be high and the RSPL for Korean speech aiudiometry be 23 dB SPL.

심층 학습 기반 정지 영상 분류와 행동 인식을 이용한 음란 동영상 탐지

이원재(Wonjae Lee),김정학(Junghak Kim),이남경(Nam Kyung Lee) 한국통신학회 2020 한국통신학회 학술대회논문집 Vol.2020 No.8