Jaewoo Kim - Academia.edu (original) (raw)

Papers by Jaewoo Kim

Journal of Nuclear Materials, 2012

In this study, the nanocomposites are prepared which used polyamide 6 (PA6) composite as matrix, ... more In this study, the nanocomposites are prepared which used polyamide 6 (PA6) composite as matrix, melamine cyanurate (MCA) as fire retardant and attapulgite (AT) as synergistic agent. The mathematical model between MCA content, AT content, and limited oxygen index (LOI) is established by multiple linear regression fitting. The polymer materials are characterized using Fourier transform infrared spectroscopy, X-ray diffraction, Thermogravimetric Analysis, and scanning electron microscopy. Through response surface methodology, the important variables (polymerization time, the content of MCA, and the content of AT) affecting the mechanical strength of composites are modeled. Results demonstrate that when the t is 0.6 h, the AT content is 6.2%, and the MCA content is 11.5%, the mechanical properties of the PA6/MCA/AT composite are up to 44.81 MPa, and the sample passes the UL-94 V-0 flammability rating, and the LOI reaches 27.9%. Therefore, polymers with highly effective flame retardancy and optimal mechanical properties are prepared.

2008 Tenth IEEE International Symposium on Multimedia, 2008

Page 1. Energy-Aware Interval Caching for Mirrored Video Servers Minseok Song, Jaewoo Kim and Bum... more Page 1. Energy-Aware Interval Caching for Mirrored Video Servers Minseok Song, Jaewoo Kim and Bumsun Lee School of Computer Science and Engineering, Inha University, Incheon, Korea mssong@inha.ac.kr, sprix@naver.com, mrbumm@gmail.com Abstract ...

Journal of Neurochemistry, 2003

Previously, we found that amyloid b-protein (Ab)1-42 exhibits neurotoxicity, while Ab1-40 serves ... more Previously, we found that amyloid b-protein (Ab)1-42 exhibits neurotoxicity, while Ab1-40 serves as an antioxidant molecule by quenching metal ions and inhibiting metal-mediated oxygen radical generation. Here, we show another neuroprotective action of nonamyloidogenic Ab1-40 against Ab1-42-induced neurotoxicity in culture and in vivo. Neuronal death was induced by Ab1-42 at concentrations higher than 2 lM, which was prevented by concurrent treatment with Ab1-40 in a dosedependent manner. However, metal chelators did not prevent Ab1-42-induced neuronal death. Circular dichroism spectroscopy showed that Ab1-40 inhibited the b-sheet transformation of Ab1-42. Thioflavin-T assay and electron microscopy analysis revealed that Ab1-40 inhibited the fibril formation of Ab1-42. In contrast, Ab1-16, Ab25-35, and Ab40-1 did not inhibit the fibril formation of Ab1-42 nor prevent Ab1-42-induced neuronal death. Ab1-42 injection into the rat entorhinal cortex (EC) caused the hyperphosphorylation of tau on both sides of EC and hippocampus and increased the number of glial fibrillary acidic protein (GFAP)-positive astrocytes in the ipsilateral EC, which were prevented by the concurrent injection of Ab1-40. These results indicate that Ab1-40 protects neurons from Ab1-42induced neuronal damage in vitro and in vivo, not by sequestrating metals, but by inhibiting the b-sheet transformation and fibril formation of Ab1-42. Our data suggest a mechanism by which elevated Ab1-42/Ab1-40 ratio accelerates the development of Alzheimer's disease (AD) in familial AD.

Journal of Mathematical Analysis and Applications, 2010

We present some regularity conditions for suitable weak solutions of the Navier-Stokes equations ... more We present some regularity conditions for suitable weak solutions of the Navier-Stokes equations near the curved boundary of a sufficiently smooth domain. Our extend the work that was results established near a flat boundary by Gustafson, Kang and Tsai (2006) [6].

Genetics Selection Evolution, 2011

Background Genomic selection is a recently developed technology that is beginning to revolutioniz... more Background Genomic selection is a recently developed technology that is beginning to revolutionize animal breeding. The objective of this study was to estimate marker effects to derive prediction equations for direct genomic values for 16 routinely recorded traits of American Angus beef cattle and quantify corresponding accuracies of prediction. Methods Deregressed estimated breeding values were used as observations in a weighted analysis to derive direct genomic values for 3570 sires genotyped using the Illumina BovineSNP50 BeadChip. These bulls were clustered into five groups using K-means clustering on pedigree estimates of additive genetic relationships between animals, with the aim of increasing within-group and decreasing between-group relationships. All five combinations of four groups were used for model training, with cross-validation performed in the group not used in training. Bivariate animal models were used for each trait to estimate the genetic correlation between der...

Clinical Therapeutics, 2012

Both mirodenafil, a phosphodiesterase type 5 inhibitor for the treatment of erectile dysfunction,... more Both mirodenafil, a phosphodiesterase type 5 inhibitor for the treatment of erectile dysfunction, and tamsulosin, a selective α(1A)-adrenergic receptor antagonist for the treatment of benign prostatic hyperplasia, have mild vasodilational effects. The aim of this study was to investigate the effect of mirodenafil on the hemodynamics of healthy volunteers who were administered tamsulosin. Healthy, Korean normotensive male volunteers were enrolled in a randomized, placebo-controlled, double-blind, 2-sequence, 2-period crossover study. Mirodenafil 100 mg or placebo was administered orally after pretreatment with tamsulosin 0.2 mg once daily for 7 days in each period, with a 1-week washout period. Blood pressure (BP) and pulse rate (PR) in supine and standing positions were measured repeatedly before and until 24 hours after the administration of mirodenafil or placebo. The mean differences from the baseline values of the maximum changes of BP and PR, which were measured at 4 and 24 hours, were analyzed by using a mixed-effects model. Eighteen subjects (mean [SD] age, 26.8 [3.9] years; weight, 65.5 [7.0] kg) were administered any trial medication, and 16 of them completed the study. For 4 hours/24 hours after mirodenafil administration, the mean maximal changes from baseline versus placebo in supine systolic BP, diastolic BP, and PR were -1.0 mm Hg (95% CI, -4.2 to 2.2) (P = 0.53)/-1.2 mm Hg (95% CI, -5.3 to 2.9) (P = 0.56), -2.1 mm Hg (95% CI, -4.6 to 0.4) (P = 0.10)/-1.1 mm Hg (95% CI, -3.9 to 1.6) (P = 0.39), and 7.2 beats/min (95% CI, 4.7 to 9.6) (P < 0.05)/4.8 beats/min (95% CI, 1.4 to 8.1) (P < 0.05), respectively. Those changes in a standing position were -4.0 mm Hg (95% CI, -8.9 to 0.9) (P = 0.10)/-4.3 mm Hg (95% CI, -10.0 to 1.5) (P = 0.13), -1.1 mm Hg (95% CI, -4.9 to 2.7) (P = 0.54)/-1.9 mm Hg (95% CI, -5.5 to 1.7) (P = 0.27), and 10.7 beats/min (95% CI, 4.4 to 16.9) (P < 0.05)/6.0 beats/min (95% CI, 0.7 to 11.3) (P < 0.05), respectively. A total of 33 adverse events (AEs) were reported in 9 of 18 subjects. The number of subjects with AEs (P = 0.13) and the number of AEs (P = 0.26) were not significantly different between the 2 groups. The most common AEs were vasodilational symptoms, such as nasal congestion, headache, and flushing. The coadministration of mirodenafil 100 mg did not induce a significant decrease in BP when associated with an increase in PR in these healthy male Korean volunteers administered tamsulosin 0.2 mg compared with placebo. (Clinical Trial Registry, http://cris.cdc.go.kr/cris/en/: KCT0000117).

Clinical Therapeutics, 2011

Background: The biosimilar is a recombinant dimeric tumor necrosis factor receptor (TNFR) under d... more Background: The biosimilar is a recombinant dimeric tumor necrosis factor receptor (TNFR) under development for the treatment of rheumatoid arthritis. Objective: The aim of this study was to compare the pharmacokinetics and/or tolerability of branded etanercept and its biosimilar in healthy Korean men before investigating the clinical efficacy of the biosimilar in subjects. Methods: Etanercept (reference, 25 mg) or its biosimilar (test, 25 mg) was subcutaneously injected to the periumbilical area of healthy volunteers in a randomized, open-label, single-dose, active-controlled, two-sequence, crossover study. Plasma concentrations of TNFR in serial blood samples for 480 hours after dosing were measured by ELISA. The primary outcome, pharmacokinetic characteristics, was assessed via geometric mean ratios (GMRs) of the log-transformed pharmacokinetic parameters. The second outcome, tolerability, was evaluated using physical examinations, electrocardiograms, clinical laboratory tests, vital sign measurements, and adverse events (AEs) by unmasked investigators. Results: Twenty-three men of mean age (%CV) 25.8 years (17.1%) and weight 70.5 kg (12.8%) were administered study medication. Four subjects dropped out after the first period; their data were included in the analysis. Both test and reference drugs were absorbed with a median T max of 72 (range, 36-144) hours and eliminated with mean (%CV) t ½ of 92.7 (20.9%) and 87.4 (16.6%) hours, respectively. The GMRs (90% CIs) of the test to reference drug for C max , AUC 0-t , and AUC 0-ϱ were 0.99 (0.83-1.17), 0.95 (0.79-1.13), and 0.95 (0.80-1.13), respectively. Eleven of 21 (52.4%) and 8 of 21 (38.1%) subjects administered the test and reference drugs reported 22 and 21 AEs, respectively. Common AEs were headache (14.3%), throat irritation (8.5%), and epistaxis (9.5%). Three serious AEs related to a traffic accident (back, neck, and musculoskeletal pain) were reported in a test drug-treated subject. Conclusions: In this select group of Korean healthy male volunteers, the reference drug and the test biosimilar met the standard criteria for assuming bioequivalence as defined by Korean regulatory authorities. Because the reference drug is a biological product, further trials for assessment of its efficacy are still required by Korean authorities.

Clinical Therapeutics, 2009

Background: Mirodenafil is a phosphodiesterase type 5 (PDE-5) inhibitor developed for the treatme... more Background: Mirodenafil is a phosphodiesterase type 5 (PDE-5) inhibitor developed for the treatment of erectile dysfunction. Mirodenafil has the possibility of being administered with alcohol. Objective: This study assessed the hemodynamic effects and pharrnacokinetic properties of mirodenafil administered with alcohol. Methods: This single-dose, randomized-sequence, open-label, crossover study was conducted in healthy male volunteers at the Clinical Trials Center, Seoul

British Journal of Clinical Pharmacology, 2008

• The only existing study of CYP2D6*10-associated alterations in flecainide pharmacokinetics was ... more • The only existing study of CYP2D6*10-associated alterations in flecainide pharmacokinetics was retrospective. • Paroxetine has been known as a strong inhibitor of CYP2D6. WHAT THIS STUDY ADDS • This study reports that the extent of drug interaction between flecainide and paroxetine is influenced by the CYP2D6*10 allele in healthy subjects, which is frequent in Asians. AIMS The objectives were to evaluate the effect of CYP2D6 genetic polymorphism on the pharmacokinetics of flecainide, and also on the extent of drug interaction with paroxetine as a CYP2D6 inhibitor after a single oral administration in healthy subjects. METHODS An open-label, two-period, single-sequence, cross-over study was performed in 21 healthy Korean male volunteers (seven for CYP2D6*1/*1 or *1/*2, group 1; seven for CYP2D6*1/*10, group 2; seven for CYP2D6*10/*10 or *10/*36, group 3). Subjects were administered 200 mg of flecainide on day 1. After a 7-day wash-out period, subjects were administered 20 mg of paroxetine from day 8 to 14, and 200 mg of flecainide on day 15. Blood sampling was performed up to 72 h after flecainide administration. RESULTS Terminal elimination half-life and mean residence time (MRT) were significantly different among three genotype groups after a single oral administration of flecainide (P = 0.021, 0.011, respectively). Area under the concentration-time curve, terminal elimination half-life and MRT increased significantly after paroxetine co-administration only in groups 1 and 2. CONCLUSIONS This study reports that the extent of drug interaction between flecainide and paroxetine is influenced by the CYP2D6*10 allele in healthy subjects, which is frequent in Asians.

Brain Research, 2005

Niemann-Pick disease type C (NPC) is characterized by progressive neurodegeneration and arises fr... more Niemann-Pick disease type C (NPC) is characterized by progressive neurodegeneration and arises from mutations in the NPC1 gene. Cholesterol has received most attention in the pathogenesis of NPC, but normalizing lipid levels in humans or mouse does not prevent neurodegeneration. In NPC mouse, neuronal degeneration in the cerebellum is the most commonly detected change, and thus previous studies have tended to focus on the cerebellum, especially Purkinje cells. Although numerous peptides have been found in the mammalian central nervous system, little data on neurotransmitters in NPC are available, and information on neurotransmitter system abnormalities could explain the complex and characteristic deficits of NPC. Thus, we performed an immunohistochemical study on NPC mouse cortices to compare cell numbers exhibiting vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and substance P (SP) immunoreactivity. In terms of VIP and NPY-immunoreactive (ir) cell numbers in the cerebral cortex, SP-ir cells were significantly reduced by about 90% in NPC (À/À) versus NPC (+/+) mouse, and were also mildly decreased in frontal and parietal NPC (+/À) versus NPC (+/+) mouse cortex. This study demonstrates for the first time, reduced number of SP-ir cells in the NPC mouse cortex.

Applied Optics, 2005

We have developed a 756 nm, 3 W single-frequency cw Ti:sapphire laser by using the technique of i... more We have developed a 756 nm, 3 W single-frequency cw Ti:sapphire laser by using the technique of injection locking. A cw Ti:sapphire laser in a ring-type configuration was forced to lase unidirectionally by use of an optical diode to prevent a high-power backward laser from disturbing the injection laser. A master laser was amplified by a broad-area laser diode and coupled into a single-mode fiber to generate a 50 mW injection laser with a Gaussian beam profile, which was enough to lock the Ti:sapphire laser at full power of 3 W. Such a high-power single-frequency Ti:sapphire laser enables a watt-level blue or near-ultraviolet single-frequency laser to be generated by frequency doubling.

Journal of Nuclear Materials, 2012

In this study, the nanocomposites are prepared which used polyamide 6 (PA6) composite as matrix, ... more In this study, the nanocomposites are prepared which used polyamide 6 (PA6) composite as matrix, melamine cyanurate (MCA) as fire retardant and attapulgite (AT) as synergistic agent. The mathematical model between MCA content, AT content, and limited oxygen index (LOI) is established by multiple linear regression fitting. The polymer materials are characterized using Fourier transform infrared spectroscopy, X-ray diffraction, Thermogravimetric Analysis, and scanning electron microscopy. Through response surface methodology, the important variables (polymerization time, the content of MCA, and the content of AT) affecting the mechanical strength of composites are modeled. Results demonstrate that when the t is 0.6 h, the AT content is 6.2%, and the MCA content is 11.5%, the mechanical properties of the PA6/MCA/AT composite are up to 44.81 MPa, and the sample passes the UL-94 V-0 flammability rating, and the LOI reaches 27.9%. Therefore, polymers with highly effective flame retardancy and optimal mechanical properties are prepared.

2008 Tenth IEEE International Symposium on Multimedia, 2008

Page 1. Energy-Aware Interval Caching for Mirrored Video Servers Minseok Song, Jaewoo Kim and Bum... more Page 1. Energy-Aware Interval Caching for Mirrored Video Servers Minseok Song, Jaewoo Kim and Bumsun Lee School of Computer Science and Engineering, Inha University, Incheon, Korea mssong@inha.ac.kr, sprix@naver.com, mrbumm@gmail.com Abstract ...

Journal of Neurochemistry, 2003

Previously, we found that amyloid b-protein (Ab)1-42 exhibits neurotoxicity, while Ab1-40 serves ... more Previously, we found that amyloid b-protein (Ab)1-42 exhibits neurotoxicity, while Ab1-40 serves as an antioxidant molecule by quenching metal ions and inhibiting metal-mediated oxygen radical generation. Here, we show another neuroprotective action of nonamyloidogenic Ab1-40 against Ab1-42-induced neurotoxicity in culture and in vivo. Neuronal death was induced by Ab1-42 at concentrations higher than 2 lM, which was prevented by concurrent treatment with Ab1-40 in a dosedependent manner. However, metal chelators did not prevent Ab1-42-induced neuronal death. Circular dichroism spectroscopy showed that Ab1-40 inhibited the b-sheet transformation of Ab1-42. Thioflavin-T assay and electron microscopy analysis revealed that Ab1-40 inhibited the fibril formation of Ab1-42. In contrast, Ab1-16, Ab25-35, and Ab40-1 did not inhibit the fibril formation of Ab1-42 nor prevent Ab1-42-induced neuronal death. Ab1-42 injection into the rat entorhinal cortex (EC) caused the hyperphosphorylation of tau on both sides of EC and hippocampus and increased the number of glial fibrillary acidic protein (GFAP)-positive astrocytes in the ipsilateral EC, which were prevented by the concurrent injection of Ab1-40. These results indicate that Ab1-40 protects neurons from Ab1-42induced neuronal damage in vitro and in vivo, not by sequestrating metals, but by inhibiting the b-sheet transformation and fibril formation of Ab1-42. Our data suggest a mechanism by which elevated Ab1-42/Ab1-40 ratio accelerates the development of Alzheimer's disease (AD) in familial AD.

Journal of Mathematical Analysis and Applications, 2010

We present some regularity conditions for suitable weak solutions of the Navier-Stokes equations ... more We present some regularity conditions for suitable weak solutions of the Navier-Stokes equations near the curved boundary of a sufficiently smooth domain. Our extend the work that was results established near a flat boundary by Gustafson, Kang and Tsai (2006) [6].

Genetics Selection Evolution, 2011

Background Genomic selection is a recently developed technology that is beginning to revolutioniz... more Background Genomic selection is a recently developed technology that is beginning to revolutionize animal breeding. The objective of this study was to estimate marker effects to derive prediction equations for direct genomic values for 16 routinely recorded traits of American Angus beef cattle and quantify corresponding accuracies of prediction. Methods Deregressed estimated breeding values were used as observations in a weighted analysis to derive direct genomic values for 3570 sires genotyped using the Illumina BovineSNP50 BeadChip. These bulls were clustered into five groups using K-means clustering on pedigree estimates of additive genetic relationships between animals, with the aim of increasing within-group and decreasing between-group relationships. All five combinations of four groups were used for model training, with cross-validation performed in the group not used in training. Bivariate animal models were used for each trait to estimate the genetic correlation between der...

Clinical Therapeutics, 2012

Both mirodenafil, a phosphodiesterase type 5 inhibitor for the treatment of erectile dysfunction,... more Both mirodenafil, a phosphodiesterase type 5 inhibitor for the treatment of erectile dysfunction, and tamsulosin, a selective α(1A)-adrenergic receptor antagonist for the treatment of benign prostatic hyperplasia, have mild vasodilational effects. The aim of this study was to investigate the effect of mirodenafil on the hemodynamics of healthy volunteers who were administered tamsulosin. Healthy, Korean normotensive male volunteers were enrolled in a randomized, placebo-controlled, double-blind, 2-sequence, 2-period crossover study. Mirodenafil 100 mg or placebo was administered orally after pretreatment with tamsulosin 0.2 mg once daily for 7 days in each period, with a 1-week washout period. Blood pressure (BP) and pulse rate (PR) in supine and standing positions were measured repeatedly before and until 24 hours after the administration of mirodenafil or placebo. The mean differences from the baseline values of the maximum changes of BP and PR, which were measured at 4 and 24 hours, were analyzed by using a mixed-effects model. Eighteen subjects (mean [SD] age, 26.8 [3.9] years; weight, 65.5 [7.0] kg) were administered any trial medication, and 16 of them completed the study. For 4 hours/24 hours after mirodenafil administration, the mean maximal changes from baseline versus placebo in supine systolic BP, diastolic BP, and PR were -1.0 mm Hg (95% CI, -4.2 to 2.2) (P = 0.53)/-1.2 mm Hg (95% CI, -5.3 to 2.9) (P = 0.56), -2.1 mm Hg (95% CI, -4.6 to 0.4) (P = 0.10)/-1.1 mm Hg (95% CI, -3.9 to 1.6) (P = 0.39), and 7.2 beats/min (95% CI, 4.7 to 9.6) (P < 0.05)/4.8 beats/min (95% CI, 1.4 to 8.1) (P < 0.05), respectively. Those changes in a standing position were -4.0 mm Hg (95% CI, -8.9 to 0.9) (P = 0.10)/-4.3 mm Hg (95% CI, -10.0 to 1.5) (P = 0.13), -1.1 mm Hg (95% CI, -4.9 to 2.7) (P = 0.54)/-1.9 mm Hg (95% CI, -5.5 to 1.7) (P = 0.27), and 10.7 beats/min (95% CI, 4.4 to 16.9) (P < 0.05)/6.0 beats/min (95% CI, 0.7 to 11.3) (P < 0.05), respectively. A total of 33 adverse events (AEs) were reported in 9 of 18 subjects. The number of subjects with AEs (P = 0.13) and the number of AEs (P = 0.26) were not significantly different between the 2 groups. The most common AEs were vasodilational symptoms, such as nasal congestion, headache, and flushing. The coadministration of mirodenafil 100 mg did not induce a significant decrease in BP when associated with an increase in PR in these healthy male Korean volunteers administered tamsulosin 0.2 mg compared with placebo. (Clinical Trial Registry, http://cris.cdc.go.kr/cris/en/: KCT0000117).

Clinical Therapeutics, 2011

Background: The biosimilar is a recombinant dimeric tumor necrosis factor receptor (TNFR) under d... more Background: The biosimilar is a recombinant dimeric tumor necrosis factor receptor (TNFR) under development for the treatment of rheumatoid arthritis. Objective: The aim of this study was to compare the pharmacokinetics and/or tolerability of branded etanercept and its biosimilar in healthy Korean men before investigating the clinical efficacy of the biosimilar in subjects. Methods: Etanercept (reference, 25 mg) or its biosimilar (test, 25 mg) was subcutaneously injected to the periumbilical area of healthy volunteers in a randomized, open-label, single-dose, active-controlled, two-sequence, crossover study. Plasma concentrations of TNFR in serial blood samples for 480 hours after dosing were measured by ELISA. The primary outcome, pharmacokinetic characteristics, was assessed via geometric mean ratios (GMRs) of the log-transformed pharmacokinetic parameters. The second outcome, tolerability, was evaluated using physical examinations, electrocardiograms, clinical laboratory tests, vital sign measurements, and adverse events (AEs) by unmasked investigators. Results: Twenty-three men of mean age (%CV) 25.8 years (17.1%) and weight 70.5 kg (12.8%) were administered study medication. Four subjects dropped out after the first period; their data were included in the analysis. Both test and reference drugs were absorbed with a median T max of 72 (range, 36-144) hours and eliminated with mean (%CV) t ½ of 92.7 (20.9%) and 87.4 (16.6%) hours, respectively. The GMRs (90% CIs) of the test to reference drug for C max , AUC 0-t , and AUC 0-ϱ were 0.99 (0.83-1.17), 0.95 (0.79-1.13), and 0.95 (0.80-1.13), respectively. Eleven of 21 (52.4%) and 8 of 21 (38.1%) subjects administered the test and reference drugs reported 22 and 21 AEs, respectively. Common AEs were headache (14.3%), throat irritation (8.5%), and epistaxis (9.5%). Three serious AEs related to a traffic accident (back, neck, and musculoskeletal pain) were reported in a test drug-treated subject. Conclusions: In this select group of Korean healthy male volunteers, the reference drug and the test biosimilar met the standard criteria for assuming bioequivalence as defined by Korean regulatory authorities. Because the reference drug is a biological product, further trials for assessment of its efficacy are still required by Korean authorities.

Clinical Therapeutics, 2009

Background: Mirodenafil is a phosphodiesterase type 5 (PDE-5) inhibitor developed for the treatme... more Background: Mirodenafil is a phosphodiesterase type 5 (PDE-5) inhibitor developed for the treatment of erectile dysfunction. Mirodenafil has the possibility of being administered with alcohol. Objective: This study assessed the hemodynamic effects and pharrnacokinetic properties of mirodenafil administered with alcohol. Methods: This single-dose, randomized-sequence, open-label, crossover study was conducted in healthy male volunteers at the Clinical Trials Center, Seoul

British Journal of Clinical Pharmacology, 2008

• The only existing study of CYP2D6*10-associated alterations in flecainide pharmacokinetics was ... more • The only existing study of CYP2D6*10-associated alterations in flecainide pharmacokinetics was retrospective. • Paroxetine has been known as a strong inhibitor of CYP2D6. WHAT THIS STUDY ADDS • This study reports that the extent of drug interaction between flecainide and paroxetine is influenced by the CYP2D6*10 allele in healthy subjects, which is frequent in Asians. AIMS The objectives were to evaluate the effect of CYP2D6 genetic polymorphism on the pharmacokinetics of flecainide, and also on the extent of drug interaction with paroxetine as a CYP2D6 inhibitor after a single oral administration in healthy subjects. METHODS An open-label, two-period, single-sequence, cross-over study was performed in 21 healthy Korean male volunteers (seven for CYP2D6*1/*1 or *1/*2, group 1; seven for CYP2D6*1/*10, group 2; seven for CYP2D6*10/*10 or *10/*36, group 3). Subjects were administered 200 mg of flecainide on day 1. After a 7-day wash-out period, subjects were administered 20 mg of paroxetine from day 8 to 14, and 200 mg of flecainide on day 15. Blood sampling was performed up to 72 h after flecainide administration. RESULTS Terminal elimination half-life and mean residence time (MRT) were significantly different among three genotype groups after a single oral administration of flecainide (P = 0.021, 0.011, respectively). Area under the concentration-time curve, terminal elimination half-life and MRT increased significantly after paroxetine co-administration only in groups 1 and 2. CONCLUSIONS This study reports that the extent of drug interaction between flecainide and paroxetine is influenced by the CYP2D6*10 allele in healthy subjects, which is frequent in Asians.

Brain Research, 2005

Niemann-Pick disease type C (NPC) is characterized by progressive neurodegeneration and arises fr... more Niemann-Pick disease type C (NPC) is characterized by progressive neurodegeneration and arises from mutations in the NPC1 gene. Cholesterol has received most attention in the pathogenesis of NPC, but normalizing lipid levels in humans or mouse does not prevent neurodegeneration. In NPC mouse, neuronal degeneration in the cerebellum is the most commonly detected change, and thus previous studies have tended to focus on the cerebellum, especially Purkinje cells. Although numerous peptides have been found in the mammalian central nervous system, little data on neurotransmitters in NPC are available, and information on neurotransmitter system abnormalities could explain the complex and characteristic deficits of NPC. Thus, we performed an immunohistochemical study on NPC mouse cortices to compare cell numbers exhibiting vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and substance P (SP) immunoreactivity. In terms of VIP and NPY-immunoreactive (ir) cell numbers in the cerebral cortex, SP-ir cells were significantly reduced by about 90% in NPC (À/À) versus NPC (+/+) mouse, and were also mildly decreased in frontal and parietal NPC (+/À) versus NPC (+/+) mouse cortex. This study demonstrates for the first time, reduced number of SP-ir cells in the NPC mouse cortex.

Applied Optics, 2005

We have developed a 756 nm, 3 W single-frequency cw Ti:sapphire laser by using the technique of i... more We have developed a 756 nm, 3 W single-frequency cw Ti:sapphire laser by using the technique of injection locking. A cw Ti:sapphire laser in a ring-type configuration was forced to lase unidirectionally by use of an optical diode to prevent a high-power backward laser from disturbing the injection laser. A master laser was amplified by a broad-area laser diode and coupled into a single-mode fiber to generate a 50 mW injection laser with a Gaussian beam profile, which was enough to lock the Ti:sapphire laser at full power of 3 W. Such a high-power single-frequency Ti:sapphire laser enables a watt-level blue or near-ultraviolet single-frequency laser to be generated by frequency doubling.