일주기리듬의 조절이상이 양극성장애의 핵심 발병 기전일까?

이헌정(Heon-Jeong Lee) 대한신경정신의학회 2018 신경정신의학 Vol.57 No.4

Circadian rhythm is a periodic and continuous change in physiological, behavioral, and mental characteristics that occurs in most organisms on the Earth, because the Earth rotates in a 24-hour cycle. The circadian system regulates daily rhythms of physiology and behavior, such as the sleep/wake cycle, body temperature, hormonal secretion, and mood. The influence of circadian rhythm is very powerful, but limited research has addressed its effects. However, many recent studies have shown that circadian dysregulation may play an important role in the pathogenesis of bipolar disorder. This review study examined current and noteworthy studies, including the authors’ own works, and proposes a possible clinical application of bipolar disorder based on evidence that circadian rhythm dysregulation in bipolar disorder may be a key pathogenetic mechanism.

흡입제 남용에서 시작된 정신병 1례

이헌정(Heon-Jeong Lee),조방현(Bang-Hyun Cho):정인과(In-Kwa Jung) 한국중독정신의학회 2001 중독정신의학 Vol.5 No.1

A 18 year-old male patient visited hospital due to psychotic symptoms. He had been sniffing volatile inhalants since 3 years ago, but he had quit sniffing 10 months ago. However he has reexperienced visual and auditory hallucinations without sniffing inhalant since 8 months ago. He had no family history of schizophrenia. The psychiatric examination revealed that he had positive symptoms of schizophrenia, such as visual hallucination, auditory hallucinations, delusion of being controlled, delusional perception, and somatic hallucination/delusion, but did not show negative symptoms. It was difficult to diagnose this case as schizophrenia or inhalant-induced psychotic disorder. This case may suggest that the positive symptoms are important manifestations of psychotic disorder due to volatile inhalant abuse. We also suggest that the psychotic symptoms of chronic inhalant abuse are serious and potentially irreversible.

안정성해석을 이용한 유체동압베어링의 동특성 최적설계

하헌정(Heon Jeong Ha),이지훈(Ji Hoon Lee),장건희(Gun Hee Jang),이경호(Kyung Ho Lee) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

The study about metal artifact reduction by using Tin-Filter in CT scan

Sang-Heon Jeong(정상헌),Seong-Ju Lee(이성주),Hyeong-Min Jin(진형민),Jong-Hyo Kim(김종효),Heon-Jung Jeong(정헌정),Dong-Seong Kim(김동성) 대한CT영상기술학회 2019 대한CT영상기술학회지 Vol.21 No.1

목적: 본 논문에서는 CT 검사 시 Tin-Filter 적용에 따라 metal artifact를 감소시킬 수 있는지에 초점을 맞추고 연구를 진행하였다. 대상 및 방법: CT장비는 SIEMENS사의 Somatom Force를 사용하였다. IM Nail을 이용하여 자체 제작한 팬텀과 AAPM 팬텀을 CTDIvol 10 mGy을 기준으로 80 kV부터 150 kV까지 10 kV단위로 스캔하여 Noise와 SNR을 구하였으며 Tin-Filter는 150 kV에 적용되었다. 정밀도를 측정하기 위한 척도로 RMSE 기법이 사용되었고, PH5 팬텀의 Liver nodule, Portal vein 두 부분을 이용하여 리커트 척도로 정성적 평가를 실시하였다. 결과 값들은 통계프로그램 SPSS를 사용하여 분산분석(ANOVA)을 진행하였다. 결과: 자체제작 팬텀 및 AAPM 팬텀을 이용한 Noise 및 SNR 평가에서 kV가 올라감에 따라 Noise가 감소하는 경향을 보였으며 특히 Tin-Filter를 적용했을 때 52.3~79.9%까지 대폭 감소하였다(P<0.01). RMSE값은 140 kV에서 최댓값인 34.27, Tin-Filter가 적용된 Tin150 kV에서 최솟값인 5.95의 값을 보였다. 리커트 척도를 이용한 정성적 평가에서도 kV 그룹 간에는 통계적으로 차이가 없어 영상의 시각적 평가에서는 차이가 없는 것으로 나타났다(p=0.792). 결론: Tin-Filter를 적용하여 검사를 진행하였을 때 선량의 증가 없이 영상의 전체적인 질은 유지하면서 metal artifact를 감소시킬 수 있는 것으로 사료된다. Purpose: In this study, we focused on whether we can reduce the metal artifact by using Tin-Filter in CT scan Somatom Force(SIEMENS,Germany) was used for the CT equipment. Materials & Method: Noise and SNR were obtained by scanning the self-produced phantom using IM Nail and AAPM phantom in units of 10 kV from 80 kV to 150 kV based on CTDIvol 10 (mGy). Tin-Filter was applied to 150 kV.RMSE was used to measure the precision, and qualitative assessment was performed by using the Likert scale on liver noduleand portal vein of PH5 phantom. Result values were analyzed by ANOVA Test using statistical program SPSS. Noise and SNR evaluation using self-produced phantom and AAPM phantom showed a tendency of noise reduction with increasing kV. Result: Especially, when Tin-Filter was applied, it decreased 52.3%~79.9% (P<0.01). The maximum value of RMSE was 34.27 at 140 kV, and the minimum value of RMSE was 5.95 at the Tin150 kV with the Tin-Filter. In the case of qualitative assessment, there was no statistically significant difference in image evaluation (p=0.792). Conclusion: As a result, it is considered that the metal artifact can be reduced without degrading the overall quality of the image and increasing the Dose, if the scan is performed using the Tin-filter.

전수면박탈이 정상인의 청각 사건관련전위에 미치는 영향

이헌정,전호석,김린,서광윤,Lee, Heon-Jeong,Chun, Ho-Seok,Kim, Leen,Suh, Kwang-Yoon 대한수면의학회 2003 수면·정신생리 Vol.10 No.2

목 적:본 연구는 청각 사건관련 전위를 이용하여 전수면박탈이 인간의 신경생리에 미치는 영향을 알아보고자 시행되었다. 방 법:고려대학교 재학생 중 건강한 자원자 24명을 대상으로 하여 총 38시간의 수면박탈을 시행하였고 2일간 아침, 저녁으로 총 네 차례 청각 사건관련 전위를 실행하였다. 결 과:P300과 N200의 잠복기가 유의하게 길어졌으며(p<0.001) 진폭도 수면박탈의 결과로 유의하게 감소하였다(p<0.05). 수면박탈에 따라서 P200의 진폭이 유의한 증가를 보였다. 그러나 N100에서는 수면박탈에 따라서 유의한 변화가 나타나지 않았다(p<0.05). 결 론:청각 사건관련전위중 P300과 N200가 수면박탈 상태를 반영하는 표지자로 생각된다. 향후 수면박탈이 사건 관련전위에 미치는 영향의 신경생리학적 기전에 관한 추가적인 연구가 필요할 것으로 생각된다. Objectives: The purpose of this study is to investigate the psychophysiological effects of total sleep deprivation by using auditory event-related potentials. Methods: Twenty four healthy college students (18 men, 6 women) participated in this study. The subjects remained awake for 37 hours under continuous surveillance. In the morning and the evening of two consecutive study days, auditory event-related potentials were checked. Results: The latencies of P300 and N200 were significantly prolonged (p<0.001) and their amplitudes decreased (p<0.05) as a consequence of sleep deprivation. The amplitude of P200 was significantly increased during sleep deprivation (p<0.05). However, there was no significant change in the latency and amplitude of N100. Conclusion: Among the components of auditory event-related potentials, P300 and N200 are good indicators of sleep-deprived status. Further investigation is necessary to elucidate the neurophysiological mechanisms of these findings.

수면박탈에 의한 P300 잠복기 연장과 성격요소와의 연관성

이헌정,전혜연,김용구,서광윤,김린,Lee, Heon-Jeong,Jeon, Hye-Yeon,Kim, Yong-Ku,Suh, Kwang-Yoon,Kim, Leen 대한수면의학회 2003 수면·정신생리 Vol.10 No.1

목 적:수면박탈은 인지기능의 저하를 가져오며 이는 신 경생리학적 변화인 P300의 잠복기 연장과 진폭의 저하를 가져온다고 보고된다. 또한 이러한 수면박탈에 의한 변화 정도에 개인의 특성이 영향을 줄 수 있다고 알려져 있다. 본 연구는 수면박탈에 의한 P300의 잠복기 연장 정도와 성격 특성의 관련성에 관하여 살펴보고자 하였다. 방 법:18명의 피험자에게 37시간 동안 수면박탈이 시행되었으며, 2일간의 실험기간동안 아침 7시와 저녁 7시에 총 4차례 P300 검사를 시행하였다. 또한 첫날 10시경에 MMPI와 STAI-T 검사를 시행하였다. 총 4회의 P300의 변화 중 아침, 저녁의 검사 결과끼리 paired t-test를 시행하였다. 이 결과에 기초하여 수면박탈에 의하여 P300의 잠복기 연장이 심하지 않은 군(n=9)(Group A)과 심한 군(n=9) (Group B), 두 군으로 나누었으며, 두 군의 MMPI의 각 척도 점수와 STAI-T 점수를 t-test 통하여 비교하였다. 결 과:수면박탈에 의하여 유의한 P300 잠복기의 연장이 있었다(p<0.005). 그러나 진폭에 있어서는 저녁시간에만 유의한 진폭의 감소가 있었다(p<0.005). 잠복기 연장이 심한 경우(Group B)와 심하지 않은 경우(Group A)를 나누어 MMPI 각 척도 값들을 t-test 시행한 결과, Group B가 Group A에 비하여 Mf척도(t=-2.16, df=16, p=0.046)와 Pa척도(t=-2.61, df=16, p=0.019)에서 유의하게 점수가 높았으며, F척도는 통계적으로 유의한 정도는 아니지만 Group B가 Group A보다 점수가 높았다(t=-2.11, df=16, p=0.052). 결 론:MMPI 소척도 중 F, Mf, Pa 척도가 높은 사람이 P300의 변화로 표현되는 수면박탈에 의한 정보처리 효율성의 저하에 취약한 것으로 보인다. 즉, F 상승으로 표현되는 주관적인 심리적 호소가 많음, Mf의 상승으로 표현되는 예민, 수동, 의존적인 면 그리고, Pa척도의 상승으로 나타나는 예민하고 투사 및 외향화하는 성격이 수면박탈에 취약하다고 추정할 수 있겠다. Objectives: The purpose of this study is to investigate the relationship between the extent of prolongation in P300 latency by sleep deprivation and personality variables. Methods: Eighteen healthy male college students participated in this study. Subjects remained awake for 37 hours under continuous surveillance. In the morning and evening of two consecutive study days, P300 was checked four times. MMPI and STAI-T were checked in the morning of the first day. The 18 subjects were divided into two groups according to their extent of P300 prolongation by sleep deprivation: Group A consisted of short P300 latency prolonged subjects, and group B of long latency prolonged subjects. The MMPI profiles and STAI-T scores of these two groups were compared. Results: Group B showed significantly higher scores in the Mf subscale (t=-2.16, df=16, p=0.046) and Pa subscale (t=-2.61, df=16, p=0.019) than group A. Group B also showed higher F subscale scores at a marginally significant level (t=-2.11, df=16, p=0.052). Conclusion: These results suggest that subjects with higher scores in F, Mf, and Pa subscales tend to have delayed cognitive process and decreased efficiency of mental process by sleep deprivation. It can be hypothesized that individuals who are sensitive, passive, dependent, and easily projecting are susceptible to the deterioration of cognitive function by total sleep deprivation.

Period3 유전자다형성과 기분 및 행동 계절성 변동의 연관성

이헌정,강승걸,김린,Lee, Heon-Jeong,Kang, Seung-Gul,Kim, Leen 대한수면의학회 2006 수면·정신생리 Vol.13 No.1

Circadian rhythms have been observed to be disturbed in mood disorders, especially seasonal affective disorder (SAD). Clock related gene variants also have been suggested to be associated with seasonality (seasonal variations in mood and behavior). This study tested the potential association between a length polymorphism of Period3 gene and seasonal variations in mood and behavior. 297 Korean college students were genotyped for the Period3 polymorphism and were for evaluated the seasonal variation by Seasonal Pattern Assessment Questionnaire (SPAQ). The genotype frequencies were 0.76 for 4R/4R, 0.22 for 4R/5R and 0.013 for 5R/5R. The global seasonality score was not different among Period3 gene variants (4R/4R, 4R/5R and 5R/5R) except for 'sleep length' subscore. The 5R/5R genotype showed the higher 'sleep length' subscore than others (p=0.024). The comparison between seasonals (syndromal plus subsyndromal SAD determined by SPAQ) and non-seasonals did not show any significant difference in frequencies of genotypes. These findings suggest that there is a possibility that the investigated Period3 polymorphism may play a partial role in the susceptibility of seasonal variations in a Korean population.

임상에서 시간약물학

이헌정,김린,Lee, Heon-Jeong,Kim, Leen 대한수면의학회 2004 수면·정신생리 Vol.11 No.2

Circadian rhythm is a global phenomenon, the control mechanisms of which are manifested at every level of biological organization, from genes and intracellular mechanisms to networks of cell populations, and to all central neuronal systems at the organismic level. In pharmacotherapy, the pharmacokinetic parameters such as drug absorption and distribution, drug metabolism, and renal elimination show diurnal variations. The symptoms and signs in diseases like asthma, myocardiac infarction, angina pectoris, hypertension and stroke also show diurnal fluctuations. These observations require drug treatment considering the circadian rhythm of body function and disease. Circadian time has to be taken into account as an important variable influencing a drug's pharmacokinetics and/or its effects or side effects in clinical practice.

만성수면부족의 사회적 영향

이헌정,김린,Lee, Heon-Jeong,Kim, Leen 대한수면의학회 2003 수면·정신생리 Vol.10 No.2

Industrialization has brought great changes in human life. Human sleep patterns have also been much influenced by industrialization and the invention of electricity and the light bulb. Insufficient sleep is a common problem with considerable health, social, and economical impacts on modern society. In this review, we will outline the present state of insufficient sleep in our society, especially catastrophic accidents related with chronic sleep insufficiency. We will discuss the effect of sleep deprivation on human performance by reviewing the literature. We will also emphasize the role of sleep specialists in this issue and highlight the areas in which the principles of sleep medicine can constructively improve public policy and public health.

아침형 & 저녁형 인간, 유전자로 결정된다

이헌정,Lee, Heon-Jeong 한국과학기술단체총연합회 2006 과학과 기술 Vol.39 No.5