• Journal of The Korean Society of Inherited Metabolic disease
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• v.2 no.1
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• pp.77-79
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• 2002

The urea cycle, consisting of a series of six enzymatic reactions, plays key roles to prevent the accumulation of toxic nitrogenous compound and synthesize arginine de novo. Five well characterized diseases have been described, resulting from an enzymatic defect in the biosynthesis of one of the normally expressed enzyme. This presentation will focus on two representative diseases; ornithine transcarbamylase(OTC) deficiency and citrullinemia(argininosuccinate synthetase deficiency). OTC deficiency is one of the most common inborn error of urea cycle, which is inherited in X-linked manner. We identified 17 different mutations in 20 unrelated Korean patients with OTC deficiency; L9X, R26P, R26X, T44I, R92X, G100R, R141Q, G195R, M205T, H214Y, D249G, R277W, F281S, 853 del C, R320X, V323M and 10 bp del at nt. 796-805. These mutations occur at well conserved nucleotide sequences across species or CpG hot spot. The L9X and R26X lead to the disruption of leader sequences, required for directing mitochondrial localization of the OTC precursor. Their phenotypes are severe, and neonatal onset. The G100R, R277W and V323M mutations were uniquely identified in patients with late onset OTC deficiency. The other genotypes are associated with neonatal onset. Out of 20 patients with OTC deficiency, only 6 patients are alive; two were liver transplanted, and normal in growth and development at 2, 4 years after transplantation respectively. Citrullinemia is an autosomal recessive disease, caused by the mutations in the argininosuccinate synthetase(ASS) gene. We identified in 3 major mutations in 11 unrelated Korean patients with citrullinemia; G324S, $IVS6^{-2}$ A to G, and 67 bp ins at nt 1125-1126. Among these, the 67 base pair insertion mutation is novel. The allele frequency of each mutation is; G324S(45%), IVS6-2 A to G(32%), and 67 base pair insertion(14%). All patients are diagnosed at neonatal or infantile age. Interestingly, two patients presented with stroke like episode. Out of 11 patients, 5 patients died. Among 6 patients alive, one patient was successfully liver transplanted.

• Archives of Pharmacal Research
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• v.26 no.1
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• pp.70-75
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• 2003

The objective of the present study was to investigate the uptake process of 4-Phenylazobenzoxycarbonyl-Pro-Leu-Gly-Pro-D-Arg (Pz-peptide), a hydrophilic and collagenase-labile pentapeptide, by isolated hepatocytes. For comparison, the uptake of Pz-peptide by Caco-2 cells and colonic cells, two known paracellular routes of Pz-peptide, was also evaluated. A simple and sensitive reversed-phase HPLC assay method using UV detection has been developed. The coefficient of variation for all the criteria of validation were less than 15%. The method was, therefore, considered to be sutable for measuring the concentration of Pz-peptide in the biological cells. Pz-peptide was extensively uptaked into hepatocytes. The initial velocity of Pz-peptide uptake assessed from the initial slope of the curve was plotted as Eadie-Hofstee plots. The maximum velocity ($V_{max}$) and the Michaelis constant ($K_m$) were 0.190$\pm$0.020 $nmol/min/10^6$ cells and 12.1$\pm$3.23 $\mu$M, respectively. The permeability-surface area product ($PS{influx}$) was calculated to be 0.0157 ml/min/10^6$ cells. $V_{max}$ and $K_m$ values for Caco-2 cells were calculated to be 6.22$\pm$0.930 pmol/min/10^6$ cells and 82.8$\pm$8.37 $\mu$M, respectively, being comparable with those of colonocytes (6.04$\pm$1.03 pmol/min/10^6$ cells and 87.8$\pm$13.2 $\mu$M, respectively). $PS_{influx}$ values for Caco-2 cells and colonocytes were calculated to be 0.0751 $\mu$l/min/10^6$ cells and 0.0688 $\mu$l/min/10^6$ cells, respectively. The more pronounced uptake of Pz-peptide by hepatocytes, when compared with Caco-2 cells and colonocytes, is probably due to its specific transporter. In conclusion, Pz-peptide, a paracellularly transported pentapeptide in the intestine and ocular epithelia, was uptaked into hepatocytes extensively. Although Pz-peptide is able to be uptaked into the Caco-2 cells and colonocytes, it is less pronounced when compared with hepatocytes. $PS_{influx}$ values of Caco-2 cells and colonocytes for unbound Pz-peptide under linear conditions were less than 0.4% when compared with that of hepatocytes.

• Korean Journal of Plant Taxonomy
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• v.50 no.1
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• pp.27-55
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• 2020

We investigated the flora of Ibamsan Mt. and Baekamsan Mt., and discuss here important vascular plants found on these mountains. We created a plant list using voucher specimens collected from Ibamsan Mt. and Baekamsan deposited at CNU. There are 769 taxa in Ibamsan Mt. and Baekamsan Mt., consisting of 116 families, 403 genera, 687 species, 16 subspecies, 58 varieties, and 8 forms. Twenty-four endemic plants of Korea were found, including Coreanomecon hylomeconoides Nakai and Eranthis byunsanensis B. Y. Sun. There are 15 rare plants on Ibamsan Mt. and Baekamsan as designated by the Korea Forest Service, including Iris koreana Nakai and Chamaegastrodia shikokiana Makino & F. Maek., as well as 14 red-list plants as designated by the Ministry of the Environment, including Lycoris chinensis var. sinuolata K. Tae & S. C. Ko ex K. Tae & S. C. Ko and Cymbidium macrorhizon Lindl. In total, there are 133 taxa of floristic regional indicator plants, including four level V taxa, such as Iris koreana Nakai; ten level IV taxa, such as Lindera sericea (Siebold & Zucc.) Blume; 28 level III taxa, such as Botrychium japonicum (Prantl) Underw.; 22 level II taxa, including Hylomecon vernalis Maxim.; and 69 level I taxa, including Dryopteris erythrosora (D. C. Eaton) Kuntze. There are 37 invasive plants, including Rumex acetosella L. and Symphyotrichum pilosum (Willd.) G. L. Nesom.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.559-565
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• 2003

An analytical method the determination of benzo(a)pyrene (BaP) and its hydroxylated metabolites, 1-hydroxybenzo(a)pyrene (1-OHBaP), 3-hydroxybenzo(a)pyrene (3-OHBaP), benzo(a)pyrene-4,5-dihydrodiol (4,5-diolBaP) and benzo(a)pyrene-7,8-dihydrodiol (7,8-diolBaP), in rat urine and plasma has been developed by HPLC/FLD and GC/MS. The derivatization with alkyl iodide was employed to improve the resolution and the detection of two mono hydroxylated metabolites, 1-OHBaP and 3-OHBaP, in LC and GC. BaP and its four metabolites in spiked urine were successfully separated by gradient elution on reverse phase ODS $C_{18}$ column (4.6 mm I.D., 100 mm length, particle size 5 ㎛) using a binary mixture of MeOH/H₂O (85/15, v/v) as mobile phase after ethylation at 90 ℃ for 10 min. The extraction recoveries of BaP and its metabolites in spiked samples with liquid-liquid extraction, which was better than solid phase extraction, were in the range of 90.3- 101.6% in n-hexane for urine and 95.7-106.3% in acetone for plasma, respectively. The calibration curves has shown good linearity with the correlation coefficients (R²) varying from 0.992 to 1.000 for urine and from 0.996 to 1.000 for plasma, respectively. The detection limits of all analytes were obtained in the range of 0.01-0.1 ng/mL for urine and 0.1-0.4 ng/mL for plasma, respectively. The metabolites of BaP were excreted as mono hydroxy and dihydrodiol forms after intraperitoneal injection of 20 mg/kg of BaP to rats. The total amounts of BaP and four metabolites excreted in dosed rat urine were 3.79 ng over the 0-96 hr period from adminstration and the excretional recovery was less than 0.065% of the injection amounts of BaP. The proposed method was successfully applied to the determination of BaP and its hydroxylated metabolites in rat urine and plasma for the pharmacokinetic studies.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.203-210
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• 2023

Ferimzone Z is a fungicide for effectively controlling rice blast. Under light irradiation conditions, it undergoes a rapid conversion to its E-stereoisomer. Given the importance of isomers in risk assessments of residues in crops, an analytical method was developed for individual isomer quantification. A comparative analysis performed using two columns in HPLC-MS/MS demonstrated that the isomers were successfully separated using the Cadenza column. For the brown rice sample preparation, 5 g of the homogenized sample was saturated with 7 mL of water. The sample was then extracted with a 10 mL mixed solvent of acetonitrile and ethyl acetate (1:1, v/v) that contained 0.1% formic acid, and it was subsequently partitioned with magnesium sulfate and sodium chloride. The upper layer was purified using dSPE containing C₁₈ and PSA sorbents. The established method was subjected to method validation, and it showed recovery rates of 90.6-98.8% (RSD ≤ 3.9%) at concentrations of 0.01, 0.1, 2 mg/kg, with a soft matrix effect (%ME) ranging from -3.1% to +6.5%. This method can be employed in monitoring studies of brown rice to determine the conversion ratio from the Z isomers to the E isomers.

• Childhood Kidney Diseases
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• v.13 no.2
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• pp.189-196
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• 2009

Purpose : The pathophysiologic mechanism of nephrotic syndrome is not yet known clearly. At least in some cases, certain 'circulating factors' are thought to increase the glomerular protein permeability. Considering the systemic effect of the circulating factor on peritoneal membrane, we evaluated the loss of protein through peritoneal membrane in patients on peritoneal dialysis due to the end stage renal disease (ESRD) caused by steroid resistant nephrotic syndrome (SRNS). Methods : We retrospectively reviewed the medical records of 26 pediatric patients on peritoneal dialysis ensued during the period from 2001 to 2007 at our clinic. Twelve patients had SRNS, while 14 patients had ESRD caused by the congenital anomalies of urinary system. Results : While the other parameters including nPNA indicating the adequacy of protein intake were similar between the two groups, serum albumin was lower in SRNS patients than the non-SRNS patients ($3.7{\pm}0.3$ g/dL vs. $4.0{\pm}0.4$ g/dL, P=0.021). Peritoneal protein loss was higher in SRNS patients than in non-SRNS patients ($3,044.4{\pm}837.6\;mg/m^2$/day vs. $1,791.6{\pm}1,244.0\;mg/m^2$/day, P=0.007). The protein permeability of the peritoneal membrane measured by the ratio of total protein concentration in dialysate to plasma was twice as high in SRNS patients as the non-SRNS ($1.06{\pm}0.46%$ vs. $0.58{\pm}0.43%$, P=0.010). After 1 year, peritoneal protein loss increased in both patient groups, but to a significantly greater degree in non-SRNS patient (P=0.023). Conclusion : The results of our study support the notion that in nephrotic syndrome there are some 'circulating factors' with the systemic effect. Since the greater protein loss through peritoneal membrane in SRNS was confirmed in this study, more meticulous nutritional support and close monitoring on the nutrition are required in these patients.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.194-201
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• 1995

In order to make clear the resistance of bag nets, the resistance R of bag nets with wall area S designed in pyramid shape was measured in a circulating water tank with control of flow velocity v and the coefficient k in $R=kSv^2$ was investigated. The coefficient k showed no change In the nets designed in regular pyramid shape when their mouths were attached alternately to the circular and square frames, because their shape in water became a circular cone in the circular frame and equal to the cone with the exception of the vicinity of frame in the square one. On the other hand, a net designed in right pyramid shape and then attached to a rectangular frame showed an elliptic cone with the exception of the vicinity of frame in water, but produced no significant difference in value of k in comparison with that making a circular cone in water. In the nets making a circular cone in water, k was higher in nets with larger d/l, ratio of diameter d to length I of bars, and decreased as the ratio S/S_m$ of S to the area $S_m$ of net mouth was increased or as the attack angle 9 of net to the water flow was decreased. But the value of ks15m was almost constant in the region of S/S_m=1-4$ or $\theta=15-90^{\circ}$ and in creased linearly in S/S_m>4 or in $\theta<15^{\circ}$ However, these variation of k could be summarized by the equation obtained in the previous paper. That is, the coefficient $k(kg\;\cdot\;sec^2/m^4)$ of bag nets was expressed as $$k=160R_e\;^{-01}(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for the condition of $R_e<100$ and $$k=100(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for $R_e\geq100$, where $S_n$ is their total area projected to the plane perpendicular to the water flow and $R_e$ the Reynolds' number on which the representative size was taken by the value of $\lambda$ defined as $$\lambda={\frac{\pi d^2}{21\;sin\;2\varphi}$$ where If is the angle between two adjacent bars, d the diameter of bars, and 21 the mesh size. Conclusively, it is clarified that the coefficient k obtained in the previous paper agrees with the experimental results for bag nets.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.69-74
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• 1994

The relationship of thyroid status and certain blood biochemical constituents with body weight gains (ADG) and age (13 to 96 weeks) was studied in Holstein Friesian ${\times}$ Hariana ($1/2F{\times}1/2H$) crossbred male calves by assessing their plasma triiodo thyronine ($T_3$), Thyroxine ($T_4$), sodium, potassium, total proteins and cholesterol level at two energy levels. Body weight gains (ADG) were higher during the 50 to 72 weeks of age and declined thereafter, the plasma $T_3$ conc. was aignificantly (p < 0.01) higher during this period compared to all other periods. There was no significant variation due to energy level. Overall mean plasma $T_3$ conc. was $1.19{\pm}0.12ng/ml$. Plasma $T_4$ conc. did not show any significant variation either between the different age periods or between the two energy levels. The mean plasma $T_4$ conc. was $37.34{\pm}1.32ng/ml$. The plasma sodium and potassium concentration did not vary significantly due to energy levels. But amongst the different age periods, sodium concentration was highest ($147.70{\pm}2.29mEq/L$) during 49-60 weeks of age and lowest ($134.70{\pm}1.78mEq/L$) during 13-24 weeks, where as for potassium concentration changes were nonsignificant. There was very little variation amongst other periods. Plasma protein level was higher at 100% energy level than at 75%. Amongst the different age period, it was significantly lower ($6.44{\pm}0.36$) during 13 to 24 weeks of age than at 37 to 48 weeks of age ($7.14{\pm}0.11$). Plasma cholesterol values were higher for 75% energy level than that of 100%. Between the periods it was highest during 61 to 72 weeks of age and the difference amongst the age period were highly significant.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.4
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• pp.273-279
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• 2012

Busulfan is an antineoplastic agent with a narrow therapeutic window. A post-hoc population pharmacokinetic analysis of a prospective randomized trial for comparison of four-times daily versus once-daily intravenous busulfan was carried out to search for predictive factors of intravenous busulfan (iBu) pharmacokinetics (PK). In this study the population PK of iBu was characterized to provide suitable dosing recommendations. Patients were randomized to receive iBu, either as 0.8 mg/kg every 6 h or 3.2 mg/kg daily over 4 days prior to hematopoietic stem cell transplantation. In total, 295 busulfan concentrations were analyzed with NONMEM. Actual body weight and sex were significant covariates affecting the PK of iBu. Sixty patients were included in the study (all Korean; 23 women, 37 men; mean [SD] age, 36.5 [10.9] years; weight, 66.5 [11.3] kg). Population estimates for a typical patient weighing 65 kg were: clearance (CL) 7.6 l/h and volume of distribution (Vd) 32.2 l for men and 29.1 L for women. Inter-individual random variabilities of CL and $V_d$ were 16% and 9%. Based on a CL estimate from the final PK model, a simple dosage scheme to achieve the target $AUC_{0-inf}$ (defined as median AUC0-inf with a once-daily dosage) of 26.18 $mg/l{\cdot}hr$, was proposed: $24.79{\cdot}ABW^{0.5}mg$ q24h, where ABW represents the actual body weight in kilograms. The dosing scheme reduced the unexplained interindividual variabilities of CL and Vd of iBu with ABW being a significant covariate affecting clearance of iBU. We propose a new simple dosing scheme for iBu based only on ABW.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.35-39
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• 2016

To conduct a kinetic study of paraquat (PQ), we investigated 9 patients with acute PQ intoxication. All of them ingested more than 20 ml of undiluted PQ herbicide to commit suicide and arrived at our hospital early, not later than 7 h after PQ ingestion. The urine dithionite test for PQ in all of the nine patients was strongly positive at emergency room. Blood samples were obtained every 30 min for the first 2~3 h and then every 1 or 2 h, as long as the clinical progression was stable among the patients for 30 h after PQ ingestion. The area under the plasma concentration-time curve ($AUC_{inf}$), which was extrapolated to infinity, was calculated using the trapezoidal rule. Toxicokinetic parameters, such as the terminal elimination half-life, apparent oral clearance, and apparent volume of distribution ($V_d/F$) were calculated. The maximum PQ concentration ($C_{max}$) and the time to reach maximum PQ concentration ($T_{max}$) were also obtained. Plasma PQ concentrations in nine patients were well described by a bi-exponential curve with a mean terminal elimination half-life of $13.1{\pm}6.8h$. $C_{max}$ and $AUC_{inf}$ were $20.8{\pm}25.7mg/l$ and $172.5{\pm}160.3h{\cdot}mg/l$, respectively. Apparent volume of distribution and apparent oral clearance were $50.9{\pm}61.3l/kg$ and $173.4{\pm}111.2l/h$, respectively. There were a significant correlation (r=0.84; p<0.05) between the PQ amount ingested and $C_{max}$. $AUC_{inf}$ also showed a significant correlation (r=0.83; p<0.05) with the PQ amount ingested. These correlations provide evidence that PQ has dose-linear toxicokinetic characteristics.