Effects of Revaprazan, a Novel Acid Antagonist, on Endocrine Function in Healthy Male Volunteers

손지홍 대한임상약리학회 2005 Translational and Clinical Pharmacology Vol.13 No.2

생동성시험 임상의 운영 사례

손지홍 한국에프디시규제과학회(구 한국에프디시법제학회) 2011 한국에프디시법제학회 학술대회 Vol.2011 No.1

무선통신 환경에서 등화기 성능 개선

손지홍,황찬호,김기만 한국ITS학회 2014 한국ITS학회 학술대회 Vol.2014 No.10

유전자 알고리즘을 이용한 결정 궤환 등화기의 탭 길이 최적화

손지홍,김기만,Son, Ji-hong,Kim, Ki-man 한국정보통신학회 2015 한국정보통신학회논문지 Vol.19 No.8

수중음향통신 채널은 다중 경로 전달이 주요 장애 요인이 되며, 일반적으로 이러한 문제점을 극복하기 위해 등화기가 적용된다. 본 논문에서는 결정 궤환 등화기의 탭 길이를 유전자 알고리즘을 통해 최적화하는 방법을 제안하였다. 유전자 알고리즘의 유전 정보를 전방향 필터와 후방향 필터의 길이로 입력받은 후, 목적함수에 따라 훈련 신호 구간에서의 BER(bit error rate)을 계산하여 필터 길이를 최적화한다. 목적함수는 결정 궤환 등화기, BER 계산으로 설정되었다. 실험 결과, 수심 25 m에 배치된 수신기에 수신된 신호에 훈련 신호만을 이용하였을 때, BER이 0.0355로 나타났다. 모든 데이터를 목적함수 내의 BER계산에 이용하였을 때, BER이 0.0215로 나타났다. In the underwater acoustic communication channels, multipath reflection become the cause of obstacle. Generally, equalizer has been applied to overcome these problems. In this paper, the method was proposed to optimize tap-length of decision feedback equalizer using genetic algorithm. After inputting feed-forward filter length and feed-back filter length as genetic information of the genetic algorithm, it optimize tap-length using BER(bit error rate) calculation in accordance with object function. The object function consist of decision feedback equalizer and BER calculation. For the purpose of BER calculation in the object function, the method was proposed to optimize the tap-length of decision feedback equalizer with genetic algorithm using preamble signals. As a result of experiments, the optimized BER is 0.0355 for signals which were received through a 25m receiver and which were applied to calculate BER merely using preamble signals in object function. When all data were used to calculate BER in object function, the optimized BER is 0.0215.

신장이식 환자에서 Rifampin과 Cyclosporine의 약동학적 상호작용

손지홍,윤영란,김경아,박지영,차인준,김양욱,김영훈,신재국,Shon, Ji-Hong,Yoon, Young-Ran,Kim, Kyoung-Ah,Park, Ji-Young,Cha, In-June,Kim, Yang-Wook,Kim, Young-Hoon,Shin, Jae-Gook 대한임상약리학회 2000 臨床藥理學會誌 Vol.8 No.1

Background: We present a case whose plasma cyclosporine concentrations were markedly decreased after adding antituberculosis medications. To assess the effect of rifampin on this pharmacokinetic interaction, we evaluated the pharmacokinetic changes of cyclosporine in kidney-transplanted patients with tuberculosis before and after withdrawing rifampin. Methods : Two separate full pharmacokinetic studies of cyclosporine were performed in four kidney recipients with tuberculosis before and one month after withdrawing rifampin from antituberculosis medications. Multiple blood samples were repeatedly drawn after morning oral dose of cyclosporine, and cyclosporine concentrations were determined by HPLC method. Pharmacokinetic parameters were estimated from noncompartmental method using $WinNonlin{\circledR}$ Results : After withdrawing rifampin, changing patterns of all pharmacokinetic parameters were consistent in all 4 subjects. Corrected Cmax and AUC estimated on the same 100mg dose basis were significantly increased from $291.1{\pm}54.1$ ng/ml to $950.7{\pm}174.7$ ng/ml and from $1483.1{\pm}92.0$ ng/ml ${\cdot}$ h to $6047.2{\pm}666.6$ ng /ml ${\cdot}$ hr, respectively (p<O.Ol). Total oral clearance (Cl/F) estimated during administration of rifampin ($19.8{\pm}3.5$ L/kg) was decreased to $6.0{\pm}0.9$ L/kg after withdrawing rifampin. However, the prolongation of halflife was not statistically significant $(6.1{\pm}1.7 hour vs)$ $10.6{\pm}1.1)$. Conclusions : These results strongly suggest that rifampin markedly decrease the plasma concentration of cyclosporine coadministered through pharmacokinetic interaction, and careful dose readjustment should be considered from frequent monitoring of plasma cyclosporine concentrations in patients taking both cyclosporine and antituberculosis medications including rifampin.

청소년 쇼트트랙 스피드 스케이트 선수의 복합기능 트레이닝이 전문체력에 미치는 영향

손지홍,안나영 한국코칭능력개발원 2023 코칭능력개발지 Vol.25 No.1

본 연구의 목적은 청소년 쇼트트랙 스피드 스케이트 선수에게 복합기능 트레이닝이 전문체력에 미치는 영향을 분석하는데 있다. 연구대상자는 D광역시 소재 쇼트트랙 스피드 스케이트 선수 6명을 대상으로 전국대회 상위입상경력을 기준으로 상위그룹(3명)과 하위그룹(3명)으로 구분하였다. 연구방법은 8주간 주 4회 1일 60분씩 복합 트레이닝을 실시하였으며, 신체구성, 기초체력, 전문체력을 측정 및분석하였다. 연구결과 복합 트레이닝 프로그램 수행 후 전문체력의 사이드 스텝에서 운동 전 그룹 간의 비교에서 상위그룹이 하위그룹보다 유의하게(p<.05) 높은 것으로 나타났으며, 운동 후 그룹 간의 비교에서도 상위그룹이 하위그룹보다 유의하게(p<.05) 높은 것으로 나타났다. 협응성(에러 횟수)는 운동 전 그룹 간의 비교에서 상위그룹이 하위그룹보다 낮은 것으로 나타났다. 그러나 두 그룹 모두반복 점프, 제자리멀리뛰기, 서전트 점프, 반응속도-소리, 협응성(소요시간)에서 유의차가 나타나지 않았다. 이와 같은 결과 청소년 쇼트트랙 스피드 스케이트 선수의 복합 트레이닝 프로그램 구성 시 경기력 향상을 위한 연령에 따른 고려가 필요할 것이다.

건강한 피험자에서 감초 수성추출물 복용이 midazolam의 약동 / 약력학에 미치는 효과

손지홍 대한임상약리학회 2005 Translational and Clinical Pharmacology Vol.13 No.1

Background : Licorice, a core traditional herbal medicine, is frequently coadministered with the conventional medications in Korea. Several reports suggested that the licorice treatment induced the cytochrome P450 (CYP) in rats, especially for CYP3A isoform. However, no report has been addressed to the effect of licorice on midazolam, CYP3A substrate, in human. This study was performed to evaluate the effect of licorice on the disposition and pharmacodynamic effects of midazolam in human. Methods : One gram of freeze dried water extract of licorice (extraction ratio ; 25%) or placebo were orally administered divided in two times to 10 healthy male subjects for 7 days as one blind randomized crossover manner with 2 weeks washout. On the day after completion of 7 days pretreatment, multiple blood samples were drawn and urine was collected for 24 hours after oral dose of 7.5 mg midazolam. Psychomotor performance tests including digit span test and digit symbol substitution test were conducted for 4 hours after midazolam administration on each phase of midazolam treatment and before pretreatment of placebo or licorice extract. The plasma concentration of midazolam and 1-hydroxymidazolam were determined with using HPLC and pharmacokinetic parameters were estimated by noncompartmental method. Results : After 1 week treatment of licorice extract, the plasma clearance of midazolam was significantly increased (1.15+0.50 vs 1.59+0.81 L/min, p<0.05) and the half-life was shortened ( 2.07+0.74 vs 1.34+0.60 hr, p<0.05) compared to those obtained after placebo treatment. Mean AUC of midazolam was decreased from 102.13+28.84 ng/ml·hr to 85.06+48.51 ng/ml·hr after licorice treatment, but not significantly different (p=0.11). There was no significant changes in AUC and urinary amount of 1-hydroxymidazolam by licorice pretreatment. The changes in the score of psychomotor performance tests (DST and DSST) measured after midazolam dosing were not significantly different between placebo and licorice pretreatment . Conclusions : Licorice water extract seems to affect the disposition of midazolam in human, but it is suggested that the CYP3A4 induction is not the major mechanism of the interaction. Further studies are remained to evaluate the mechanism of the pharmacokineitc interaction between midazolam and licorice water extract.

적정약물요법을 위한 약동학/약력학적 개념

손지홍,신재국 大韓臨床藥理學會 2000 臨床藥理學會誌 Vol.8 No.1

수중음향통신을 위한 훈련 신호 구간의 비트 오차율에 기반한 레이크 수신기

손지홍,김기만,Son, Ji-hong,Kim, Ki-man 한국정보통신학회 2016 한국정보통신학회논문지 Vol.20 No.5

수중음향통신 채널은 다중 경로 전달이 주요 장애 요인이 되며, 이러한 문제점을 해결하기 위해 레이크 수신기를 이용하여 이를 통해 시간 다이버시티 효과를 얻을 수 있다. 그러나 수중음향통신 채널은 시변동성이 높은 채널로써 적합하지 못한 경로의 신호를 복조에 이용하게 될 우려가 있다. 이를 방지하기 위해 본 논문에서는 훈련 신호의 오차율에 기반을 두어 경로 선택 및 가중치 할당하는 레이크 수신기를 제안한다. 호수 실험을 통해 제안된 레이크 수신기와 기존의 레이크 수신기, 레이크 방법을 사용하지 않은 일반 수신기를 이용하여 성능을 분석하였다. 분석 결과, 전송비트 512개 중에서 제안된 레이크 수신기는 8개, 기존의 레이크 수신기는 45개, 그리고 레이크 수신기를 사용하지 않은 일반 수신기는 72개의 비트오류가 발생하였다. In the underwater acoustic communication channels, a multipath reflection becomes the cause of obstacle. To solve this problem, a rake receiver has been required for which one could take the time diversity. However, there is a concern about using incorrect path to recover signals with a high weighting value as underwater acoustic communication channels have severe time-variant property. In order to prevent these problem, a rake receiver is proposed which is based on BER(bit error rate) train sequence duration. The performance is evaluated through lake trials; there are three methods that are a proposed rake receiver, a conventional rake receiver, and a non-rake receiver. As a result, the number of bit errors in the proposed rake receiver, that of bit errors in the conventional rake receiver, and that of bit errors in the non-rake receiver is 8, 45, and 72, respectively.

MDR1 C3435T 및 G2677T 유전적 다형성에 따른 Fexofenadine의 약동학 및 약력학적 분석

손지홍 대한임상약리학회 2004 Translational and Clinical Pharmacology Vol.12 No.1

Background : Multi-drug resistance 1 (MDR1) gene encoded P-glycoprotein(Pgp) contributes to the disposition of many substrate drugs. Recently, many reports have been described for the single nucleotide polymorphisms (SNPs) of MDR1 gene and their functional significances in vitro and in vivo. This study is to evaluate the effect of MDR1 C3435T/G2677T genetic polymorphism on the pharmacokinetics (PK) and pharmacodynamics (PD) of fexofenadine, a known Pgp substrate, in Korean healthy subjects. Methods : Fifteen male subjects whose MDR1 C3435T/G2677T genotype was determined using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) method were enrolled (8 subjects with CC for 3435 and GG for 2677 ; 7 subjects with TT for 3435 and TT for 2677). After single oral dose of 120 mg fexofenadine, blood samples were serially drawn upto 24 hours. Histamine induced wheal and flare reaction test was also conducted for 3 hours after dosing to measure pharmacodynamic effect of fexofenadine. Concentrations of fexofenadine were analyzed with HPLC using fluorescence detector. Kinetic parameters were calculated by fitting the data to noncompartmental PK models using WinNonlin program. Results : The plasma concentrations of fexofenadine were higher, especially in absorptive phase, in subjects with 3435T/2677T haplotype than those in subjects with 3435C/2677G wild haplotype. Although there was no significant difference of pharmacokinetic parameters between genotype groups, area under the plasma concentration from 0 to 6(AUC6hr) showed significant differences between genotype groups(p<0.05). The time course of wheal and flare suppression showed no statistical difference between genotype groups, but subjects with 3435T/2677T haplotype showed higher antihistamine effect that those with 3435C/2677G wild haplotype. Conclusions : These results suggest that MDR1 C3435T/G2677T genetic polymorphism seem likely to be associated with fexofenadine disposition, implying that SNPs at 2677 and 3435 may have an effect on Pgp expression or activity in the intestinal epithelium.