• 대한의용생체공학회:의공학회지
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• 제38권3호
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• pp.123-128
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• 2017

Background and aims: The KCNQ1 S140G mutation involved in $I_{ks}$ channel is a typical gene mutation affecting atrial fibrillation. However, despite the possibility that the S140G gene mutation may affect not only atrial but also ventricular action potential shape and ventricular responses, there is a lack of research on the relationship between this mutation and ventricular fibrillation. Therefore, in this study, we analyzed the correlation and the influence of the KCNQ1 S140G mutant gene on ventricular fibrillation through computer simulation studies. Method: This study simulated a 3-dimensional ventricular model of the wild type(WT) and the S140G mutant conditions. It was performed by dividing into normal sinus rhythm simulation and reentrant wave propagation simulation. For the sinus rhythm, a ventricular model with Purkinje fiber was used. For the reentrant propagation simulation, a ventricular model was used to confirm the occurrence of spiral wave using S1-S2 protocol. Results: The result showed that 41% shortening of action potential duration(APD) was observed due to augmented $I_{ks}$ current in S140G mutation group. The shortened APD contributed to reduce wavelength 39% in sinus rhythm simulation. The shortened wavelength in cardiac tissue allowed re-entrant circuits to form and increased the probability of sustaining ventricular fibrillation, while ventricular electrical propagation with normal wavelength(20.8 cm in wild type) are unlikely to initiate re-entry. Conclusion: In conclusion, KCNQ1 S140G mutation can reduce the threshold of the re-entrant wave substrate in ventricular cells, increasing the spatial vulnerability of tissue and the sensitivity of the fibrillation. That is, S140G mutation can induce ventricular fibrillation easily. It means that S140G mutant can increase the risk of arrhythmias such as cardiac arrest due to heart failure.

• Journal of Korean Biological Nursing Science
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• 제3권1호
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• pp.1-10
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• 2001

뇌손상이라고 하는 과도한 stress를 받았을 때 free cortisol의 분비되는 양과 urinary free cortisol의 circadian 리듬에 어떻게 영향을 주는지 확인하기 위하여 시도하였다. 연구대상은 대조군은 건강한 젊은 여성 6명과 실험군응 CT상 뇌에 손상을 받은 4명의 여성으로 30대 환자이었다. 담당의사와 중환자실 관리책임자의 동의하에서 시도되었으며, 실험기간은 2000년 7월 1일에서 7월 10일까지였다. 대조군과 실험군의 뇨를 채취하여 뇨중 free cortisol 농도의 circadian rhythm을 알아보기 위해 채뇨 후 분석하였다. 채뇨는 뇌손상을 받고 응급실을 통해 신경외과 중환자실에 입원한 지 5시간 이내에 해당된 환자로 24시간 유지되는 foley catherization 상태하에서 12:00부터 3일동안 72시간을 2시간 간격으로 채뇨하였고, 대조군은 오전 12시부터 24시간 동안 2시간 간격으로 채뇨하였다. 측정방법으로는 cortisol의 정량은 solid-phase radioimmuoassay 방법을 이용하였으며, 분석재료는 Coat-A-Count(R) Cortisol kit(DPC, U.S.A.)을 사용하여 DPC사의 측정방법을 따랐다. 연구대상자의 free cortisol의 총량은 대조군에서는 $42.8{\mu}g$이었고, 실험군은 1일에 $991.2{\mu}g$, 2일에 $809{\mu}g$, 3일에 $544.2{\mu}g$으로 대조군과 통계적으로 유의한 차이를 나타내(p<.05), 실험군에서 현저하게 증가된 양상을 보였고, 시간이 지나면서 점점 감소하는 경향을 나타냈다. 시간별로 t-검정으로 분석한 결과로는 모든 시간대에서 대조군과 실험군의 평균치는 통계적으로 유의한 차이를 나타냈다. Free cortisol의 circadian에서는 대조군에서는 정상인의 cortisol의 circadian의 경우와 같은 리듬을 보였으나, 손상을 받은 실험군의 경우 분비량은 현저하게 증가했음을 보여주었다. 최고치가 제1일에 18:00과 다음날 10:00에 나타나 최고치가 2회 나타났으며, 제2일에도 제1일과 마찬가지로 18:00에 나타났고, 제3일에는 24:00에 나타나 제1일보다 제2일에는 최고치가 한 번 나타난 리듬을 보여주었고, 분비량은 2일에 감소하였다. 제3일에는 최고치가 8시간 지연된 나타난 리듬의 변화를 보여주었다. 최저치는 제1일, 제2일, 제3일 모두 24:00에 나타난 리듬을 보여주었다. 이상의 결과에서 실험군인 뇌손상 환자군에서는 뇌손상이 과도한 stress로 작용하여 환자의 free cortisol 분비량과 circadian 리듬에도 영향을 주는 것으로 나타났다. 그러므로 뇌손상환자를 간호하는 간호사는 스트레스상태인 것을 인지하여 환자 개개인에 필요한 간호를 해야 할 것으로 사료된다.

• Animal cells and systems
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• 제13권2호
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• pp.119-125
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• 2009

Mammalian hibernation is a type of natural adaptation that allows organisms to avoid harsh environment and to increase the possibility of survival. To investigate the molecular link between circadian and hibernating rhythms in the greater tube-nosed bats, Murina leucogaster, we set out to identify circadian genes that are expressed in bats, with specific focus on the PAS domain by using PCR-based screens. We could isolate a eDNA clone, designated as LPAS1, that encodes a protein of 521 amino acid residues. LPAS1 is closely related with CLOCK family with the highest homology to human CLOCK. Based on RT-PCR analyses, LPAS1 transcripts are ubiquitously present in tissues from both summer active and winter dormant periods. Given that LPAS1 is a member of the bHLH-PAS protein superfamily but lacks polyglutamine transactivation domains, it is likely to function as a repressor for endogenous CLOCK to hinder its roles in promoting transcription. Our result will open a new avenue to further examine the functional interconnection between the circadian clock and the circannual clock such as mammalian hibernation.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.412.2-413
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• 2002

Purpose. To prepare polymer based physical mixtures or solid dispersions containing solubilizing compositions using a spray-dryer. Methods. Lovastatin.simvastatin.aceclofenac and cisapride were selected as poorly water-soluble drugs. Dextrin. poly(vinylalcohol). poly(vinylpyrrolidone)and polyethylene glycol were chosen as solubilizing carriers for solid dispersions. The solid dispersions containing solubilizing compositions without drug were prepared without using organic solvents or tedious changes of formulation compositions. (omitted)

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2006년도 The 6th Intermational Symposium on Developmental Biotechnology
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• pp.60-61
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• 2006

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.412.1-412.1
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• 2002

Purpose. To prepare PVP-based solid dispersions containing lovastatin (LOS) and solubilizers (sodium lauryl sulfate. Tween80. oleic acid) to enhance dissolution of practically insoluble LOS. Methods. Solid dispersions containing LOS were prepared by dissolving two different organic solvent systems (acetone/ethanol or acetonitrile/ethanol). Results. The stickiness and flowability of solid dispersion powders were dependent on the composition and ratio of the solubilizers. (omitted)

• 동의생리병리학회지
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• 제19권5호
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• pp.1154-1161
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• 2005

Yin Yang theory is the first and the last one to interpret diseases apply to treatment in oriental medicine. So it is regarded as the way of heaven and earth, the discipline of all things, the origin of change, the beginning of giving birth and death, the source of spirit. These regulatory passages are needed to compare with western medical physiology and analyzed whether it has scientific bases or not. The Yin Yang theory of traditional oriental medicine are summerized from the descriptions of Scripture of Documents, Ying Wei theory of Huangdi Neijing. Meanwhile up-to-date neurobiological and molecular genetic theories on circadian physiology are reviewed in western medicine. Sunshine is transferred through RGC to SCN, herein the central circadian rhythm is made by zeitgeber and interaction of melatonin secreted from pineal body and orexin from mp pan of hypothalamus. So HPA axis is activated and controlled under the circadian rhythm and affects peripheral tissues and cells of whole body through glucocorticoid hormones. First of all, the circadian rhythm makes the basic patterns of human life in biological and sociological meaning. It is almost same context with the record of the Scripture of Documents. Also the Ying Qi and Wei Qi is basically same with the sleep-awake mechanism, that is melatonin/orexin signal or per/clk/bmal/cry genes with circadian activation and activity of each organ's physiological function. Conclusively it can be said that Yin Yang is a priori principle of living things and the beginning of giving birth and death for activation of them biologically, as is described in Huangdi Neijing.

• The Korean Journal of Physiology and Pharmacology
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• 제25권6호
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• pp.575-583
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• 2021

Composition of the gut microbiota changes with aging and plays an important role in age-associated disease such as metabolic syndrome, cancer, and neurodegeneration. The gut microbiota composition oscillates through the day, and the disruption of their diurnal rhythm results in gut dysbiosis leading to metabolic and immune dysfunctions. It is well documented that circadian rhythm changes with age in several biological functions such as sleep, body temperature, and hormone secretion. However, it is not defined whether the diurnal pattern of gut microbial composition is affected by aging. To evaluate aging effects on the diurnal pattern of the gut microbiome, we evaluated the taxa profiles of cecal contents obtained from young and aged mice of both sexes at daytime and nighttime points by 16S rRNA gene sequencing. At the phylum level, the ratio of Firmicutes to Bacteroidetes and the relative abundances of Verrucomicrobia and Cyanobacteria were increased in aged male mice at night compared with that of young male mice. Meanwhile, the relative abundances of Sutterellaceae, Alloprevotella, Lachnospiraceae UCG-001, and Parasutterella increased in aged female mice at night compared with that of young female mice. The Lachnospiraceae NK4A136 group relative abundance increased in aged mice of both sexes but at opposite time points. These results showed the changes in diurnal patterns of gut microbial composition with aging, which varied depending on the sex of the host. We suggest that disturbed diurnal patterns of the gut microbiome can be a factor for the underlying mechanism of age-associated gut dysbiosis.

• The Journal of Korean Physical Therapy
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• 제25권6호
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• pp.374-378
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• 2013

Purpose: Human body have biological rhythmic pattern in a day, which is affected by internal and external environmental factors. We investigated whether respiratory function was fluctuated according to the influence of time-of-day (around at 9 am, 1 pm, and 6 pm) in health subjects, using pulmonary function test (PFT). Methods: Eighteen healthy volunteers (8 men, mean ages; $22.4{\pm}1.6$, mean heights; $166.61{\pm}9.60$, mean weight; $59.3{\pm}10.3$) were recruited. Pulmonary function test (PFT) was measured at three time points in day, around 9 am, 1 pm, and 6 pm in calm research room with condition of under 55dB noise level, using a spirometer (Vmax 229, SensorMecis, USA). Forced vital capacity (FVC), forced expiratory volume at one second (FEV1), FVC/FEV1, and peak expiratory flow (PEF) were acquired. Results: In comparison of raw value of PFT among three time points, subjects showed generally better respiratory function at 9 am, than at other points, although no significance was found. In comparison of distribution of ranking for respiratory function in each individual, only PEF showed significant difference. In general, distributional ratio of subjects who showed best performance of respiratory function in a day was high. Conclusion: These findings showed that circadian rhythm by diurnal pattern was not detected on respiratory function throughout all day. But, best performance on respiratory function was observed mostly in the morning, although statistical significance did not exist.

• 한국발생생물학회지:발생과생식
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• 제12권1호
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• pp.9-18
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• 2008

현존하는 생물들은 주변 환경에서 오는 반복되는 신호의 영향을 받고 있다. 그 신호는 태양 및 지구의 운동 관계에서 되풀이되어 일어나는 주기적인 변화이다. 생식 및 번식, 세포 내 각종 분자들의 작용, 발생 단계에 일어나는 다양한 변화 등등의 생리학적/행동학적 활동들은 모두 일주기든 연주기든 주기성을 띠고 있다. 일주기 리듬을 통하여 생물들은 근본적으로 주변의 외부 시간에 그 생물 자체가 적응하게 하여, 일상적으로 반복되는 환경에서 적절한 시기에 활동하도록 하는 것이다. 각종 리드미컬한 패턴 중에 편승 변환을 고찰하기 위해 제시된 한계주기궤도에 초점을 맞추어 고찰하고자 한다.