• Title/Summary/Keyword: Physiological cycle

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Autophagy in Ischemic Livers: A Critical Role of Sirtuin 1/Mitofusin 2 Axis in Autophagy Induction

  • Chun, Sung Kook;Go, Kristina;Yang, Ming-Jim;Zendejas, Ivan;Behrns, Kevin E.;Kim, Jae-Sung
    • Toxicological Research
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    • v.32 no.1
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    • pp.35-46
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    • 2016
  • No-flow ischemia occurs during cardiac arrest, hemorrhagic shock, liver resection and transplantation. Recovery of blood flow and normal physiological pH, however, irreversibly injures the liver and other tissues. Although the liver has the powerful machinery for mitochondrial quality control, a process called mitophagy, mitochondrial dysfunction and subsequent cell death occur after reperfusion. Growing evidence indicates that reperfusion impairs mitophagy, leading to mitochondrial dysfunction, defective oxidative phosphorylation, accumulation of toxic metabolites, energy loss and ultimately cell death. The importance of acetylation/deacetylation cycle in the mitochondria and mitophagy has recently gained attention. Emerging data suggest that sirtuins, enzymes deacetylating a variety of target proteins in cellular metabolism, survival and longevity, may also act as an autophagy modulator. This review highlights recent advances of our understanding of a mechanistic correlation between sirtuin 1, mitophagy and ischemic liver injury.

Aging and UV Irradiation Related Changes of Gene Expression in Primary Human Keratinocytes

  • Lee, Ok Joo;Lee, Sung-Young;Park, Jae-Bong;Lee, Jae-Yang;Kim, Jong-Il;Kim, Jaebong
    • Genomics & Informatics
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    • v.3 no.2
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    • pp.66-72
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    • 2005
  • The epidermis is a physiological barrier to protect organisms against environment. During the aging process, skin tissues undergo various changes including morphological and functional changes. The transcriptional regulation of genes is part of cellular reaction of aging process. In order to examine the changes of gene expression during the aging process, we used the primary cell culture system of human keratinocytes. Since UV radiation is the most important environmental skin aggressor, causing skin cancer and other problems including premature skin aging, we examined the changes of gene expression in human keratinocytes after UV irradiation using oligonucleotide microarray containing over 10,000 genes. We also compared the gene expression patterns of the senescent and UV treated cells. Expression of the variety of genes related to transcription factors, cell cycle regulation, immune response was altered in human keratinocytes. Some of down-regulated genes are represented in both senescent and UV treated cells. The results may provide a new view of gene expression following UVB exposure and aging process in human keratinocytes.

Study on Medical Treatment by the Zang-qi-fa-shi(藏氣法時) (장기법시(藏氣法時)의 관점(觀点)으로 본 치법(治法) 연구(硏究))

  • Kim, Hyun-Jung;Kang, Jung-Soo
    • Journal of Haehwa Medicine
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    • v.16 no.2
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    • pp.99-107
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    • 2007
  • Keeping in step with four seasons, Spring, summer, autumn, and winter, the heaven and earth(天地) has been born(生), grown(長), coverted(化), gained(收), and kept(藏) by interaction of yiyang and yuqi(五氣: 木火土金水). And according to Naiching, human being is born with energy of heaven and earth(天地之氣) and is grown with the law of four seasons(四時之法). So, we now know that the human's body and nature interact each other. The oriental medical science has been studied the effect that the nature's change influences on human body. Now, I get some idea that using herb medicine and acupuncture should have hanged following the change of four seasons. We know that there is a cycle in nature. Every day sun arise and down, and every month moon gets full and new. And every year, four seasons orderly change, from spring to winter. All of this is the law of nature and human body adapts this law. Man always shows the physiological phenomena which changes under the law of nature, especially the turning of the seasons. Therefore, we should use different medical methods in different seasons.

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Evaluation of Thermal Comfort during Sleeping in Summer - Part III : About Indoor Air Temperatures Rise - (여름철 수면시 온열쾌적감 평가 - 제3보 : 실내온도 상승에 관하여 -)

  • Kim Dong-Gyu;Kum Jong-Soo;Kim Se-Hwan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.7
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    • pp.535-540
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    • 2006
  • This study was performed In evaluate sleep efficiencies and conditions for comfortable sleep based on the analysis of Physiological signals under variations in thermal conditions. Five female subjects who have similar life cycle and sleep patterns were participated for the sleep experiment. It was checked whether they had a good sleep before the night of experiment. EEGs were obtained from C3-A2 and C4-A1 electrode sites and EOGs were acquired from LOC (left outer canthus) and ROC (right outer canthus) for REM sleep detection. Sleep stages were classified, then TST (total sleep time), SWS (slow wave sleep) latency and SWS/TST were calculated for the evaluation of sleep efficiencies on thermal conditions. TST was defined as an amount of time from sleep stage 1 to wakeup. SWS latency was from light off time to sleep stage 3 and percentage of SWS over TST was calculated for the evaluation of sleep quality and comfort sleep under thermal conditions. As result, the condition which raise a room temperature provided comfortable sleep.

Lower Extremity Stiffness Characteristics in Running and Jumping: Methodology and Implications for Athletic Performance

  • Ryu, Joong Hyun
    • Korean Journal of Applied Biomechanics
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    • v.28 no.1
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    • pp.61-67
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    • 2018
  • Objective: The human body is often modelled as a spring-mass system. Lower extremity stiffness has been considered to be one of key factor in the performance enhancement of running, jumping, and hopping involved sports activities. There are several different classification of lower extremity stiffness consisting of vertical stiffness, leg stiffness, joint stiffness, as well as muscle and tendon stiffness. The primary purpose of this paper was to review the literature and describe different stiffness models and discuss applications of stiffness models while engaging in sports activities. In addition, this paper provided a current update of the lower extremity literature as it investigates the relationships between lower extremity stiffness and both functional performance and injury. Summary: Because various methods for measuring lower extremity stiffness are existing, measurements should always be accompanied by a detailed description including type of stiffness, testing method and calculation method. Moreover, investigator should be cautious when comparing lower extremity stiffness from different methods. Some evidence highlights that optimal degree of lower extremity stiffness is required for successful athletic performance. However, the actual magnitude of stiffness required to optimize performance is relatively unexplored. Direct relationship between lower extremity stiffness and lower extremity injuries has not clearly been established yet. Overall, high stiffness is potentially associate risk factors of lower extremity injuries although some of the evidence is controversial. Prospective injures studies are necessary to confirm this relationship. Moreover, further biomechanical and physiological investigation is needed to identify the optimal regulation of the lower limb stiffness behavior and its impact on athletic performance and lower limb injuries.

Occurrence and Epidemics of Bacterial Canker of Kiwifruit in Korea

  • Kim, Gyoung Hee;Jung, Jae Sung;Koh, Young Jin
    • The Plant Pathology Journal
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    • v.33 no.4
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    • pp.351-361
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    • 2017
  • Bacterial canker is the largest limiting factor in the cultivation and production of kiwifruit worldwide. Typical symptoms comprise necrotic spots on leaves, canker and dieback on canes and trunks, twig wilting, and blossom necrosis. Pseudomonas syringae pv. actinidiae (Psa), which is the causal agent of kiwifruit bacterial canker, is divided into four biovars based on multilocus sequence analysis of different genes, additional PCR testing of pathogenic genes (argKtox cluster, cfl, and various effector genes), and biochemical and physiological characterization. Bacterial canker caused by Psa biovar 2 designated Psa2 was detected for the first time on the green-fleshed kiwifruit cultivar Hayward in 1988 and the yellow-fleshed kiwifruit cultivar Hort16A in 2006 in Korea. Psa biovar 3 designated Psa3, responsible for the current global pandemics of kiwifruit bacterial canker, began to appear in Korea in 2011 and caused tremendous economic losses by destroying many vines or orchards of yellow-fleshed kiwifruit cultivars in one or several growing seasons. Bacterial canker epidemics caused by both Psa2 and Psa3 are prevalent in Korea in recent years. In this review, we summarize the symptomatology, etiology, disease cycle, diagnosis, and epidemiology of kiwifruit bacterial canker in Korea.

Regulatory Effects of Samul-tang on Axonal Recovery after Spinal Cord Injury in Rats

  • Lee, Ki-Tae;Kim, Yoon-Sik;Ryu, Ho-Ryong;Jo, Hyun-Kyeng;An, Jung-Jo;Namgung, Uk;Seol, In-Chan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.5
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    • pp.1303-1310
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    • 2006
  • In oriental medicine, Samul-tang (SMT) has been used for the treatment of cardiovascular diseases and neuronal disorders. Here, possible effects of SMT on axonal regeneration after the spinal cord injury were examined. SMT treatment induced increases in regeneration-related proteins GAP-43, cell division cycle 2 (Cdc2) and phospho-Erk1/2 in the peripheral sciatic nerves after crush injury. Increased levels of Cdc2 and phospho-Erk1/2 were observe mostly in the gray matter area and some in the dorsomedial white matter. These increases correlated with increased cell numbers in affected areas. Moreover, axons of corticospinal tract (CST) showed increased sprouting in the injured spinal cord when administrated with SMT compared with saline-treated control. Thus, the present data indicate that SMT may be useful for identifying active components and for therapeutic application toward the treatment of spinal cord disorders after injury.

Glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonists in the treatment of type 2 diabetes

  • Lee, Seungah;Lee, Dong Yun
    • Annals of Pediatric Endocrinology and Metabolism
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    • v.22 no.1
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    • pp.15-26
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    • 2017
  • The prevalence of type 2 diabetes (T2D) is increasing worldwide. Patients with T2D suffer from various diabetes-related complications. Since there are many patients with T2D that cannot be controlled by previously developed drugs, it has been necessary to develop new drugs, one of which is a glucagon-like peptide-1 (GLP-1) based therapy. GLP-1 has been shown to ameliorate diabetes-related conditions by augmenting pancreatic ${\beta}-cell$ insulin secretion and having the low risk of causing hypoglycemia. Because of a very short half-life of GLP-1, many researches have been focused on the development of GLP-1 receptor (GLP-1R) agonists with long half-lives such as exenatide and dulaglutide. Now GLP-1R agonists have a variety of dosing-cycle forms to meet the needs of various patients. In this article, we review the physiological features of GLP-1, the effects of GLP-1 on T2D, the features of several GLP-1R agonists, and the therapeutic effect on T2D.

Polyploidization of Hepatocytes: Insights into the Pathogenesis of Liver Diseases

  • Kim, Ju-Yeon;Choi, Haena;Kim, Hyeon-Ji;Jee, Yelin;Noh, Minsoo;Lee, Mi-Ock
    • Biomolecules & Therapeutics
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    • v.30 no.5
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    • pp.391-398
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    • 2022
  • Polyploidization is a process by which cells are induced to possess more than two sets of chromosomes. Although polyploidization is not frequent in mammals, it is closely associated with development and differentiation of specific tissues and organs. The liver is one of the mammalian organs that displays ploidy dynamics in physiological homeostasis during its development. The ratio of polyploid hepatocytes increases significantly in response to hepatic injury from aging, viral infection, iron overload, surgical resection, or metabolic overload, such as that from non-alcoholic fatty liver diseases (NAFLDs). One of the unique features of NAFLD is the marked heterogeneity of hepatocyte nuclear size, which is strongly associated with an adverse liver-related outcome, such as hepatocellular carcinoma, liver transplantation, and liver-related death. Thus, hepatic polyploidization has been suggested as a potential driver in the progression of NAFLDs that are involved in the control of the multiple pathogenicity of the diseases. However, the importance of polyploidy in diverse pathophysiological contexts remains elusive. Recently, several studies reported successful improvement of symptoms of NAFLDs by reducing pathological polyploidy or by controlling cell cycle progression in animal models, suggesting that better understanding the mechanisms of pathological hepatic polyploidy may provide insights into the treatment of hepatic disorders.

Experimental Study on the Expression of Hair Growth Related Factors after Bee Venom Acupuncture Therapy (봉독약침요법(蜂毒藥鍼療法)에 의한 발모관련 인자들의 발현에 대한 연구)

  • Kim, Ho-Il;Kim, Cheong-Moo;Shin, Hyun-Jong;Lee, Chang-Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.3
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    • pp.496-502
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    • 2011
  • The present study was undertaken to investigate the effect of bee venom acupuncture therapy on the hair follicle growth by macroscopic, microscopic and immunohistochemical observation of skin 10 and 17 days after treatment. The results were as follows : Macroscopic hair follicle growth of 0.2 ml S.B.V. acupuncture treated group was more prominent than those of 0.1 ml S.B.V. acupuncture treated group and control group. Microscopic observation indicated that the hair follicle growth of control group reached anagen phase IV of hair growing cycle, and that of 0.1 ml and 0.2 ml S.B.V. acupuncture treated groups reached anagen phase VI and catagen, respectively. Immunohistochemical observations of the expression of various cytokines, enzymes and receptors in association with hair follicle cycle after local treatment of S.B.V. acupuncture therapy are as follows: Expression of fibroblast growth factor was more intense in epidermis and outer root sheath in 0.2 ml S.B.V. acupuncture treated group than that of 0.1 ml S.B.V. acupuncture treated group and control group. Expression of epidermal growth factor was more intense in bulge and outer root sheath in 0.2 ml S.B.V. acupuncture treated group than that of 0.1 ml S.B.V. acupuncture treated group and control group. Expression of c-kit receptor was more intense in epidermis, bulge and outer root sheath in 0.2 ml S.B.V. acupuncture treated group than that of control group. Expression of vascular endothelial growth factor was more intense in epidermis, bulge and outer root sheath in 0.2 ml S.B.V. acupuncture treated group than that of control group. Expression of protein kinase C-${\alpha}$ was more intense in epidermis, bulge and outer root sheath in 0.2 ml S.B.V. acupuncture treated group than control group. It is concluded that bee venom acupuncture therapy promoted the expression of various cytokines, enzymes and receptors related to the hair growth cycle for hair growth. This findings indicates that bee venom acupuncture therapy is applicable to the treatment of hair loss.