• Journal of Microbiology and Biotechnology
• /
• 제25권8호
• /
• pp.1307-1314
• /
• 2015

Leukemia inhibitory factor (LIF) is a member of the IL-6 cytokine family, having pleiotropic actions such as maintaining stem cell pluripotency and enabling blastocyst implantation. Because the action of LIF is mediated by a ligand-receptor interaction with the LIF receptor (LIF-R), an antagonist for LIF-R has been developed to inhibit LIF-induced signaling. In this study, we present a novel method for the production and purification of an antagonist to human LIF-R (hLA). His-tagged hLA was expressed in E. coli, and simple purification methods without any endopeptidase cleavage were designed. In addition, we determined the optimal temperature conditions for enhancing the production of soluble hLA. Finally, the bioactivity of His-tagged hLA was examined using STAT3 phosphorylation and receptivity of human endometrial ECC-1 cells. Our strategy provides a rapid and efficient method to produce biologically active recombinant hLA.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2004년도 춘계종합학술대회
• /
• pp.500-504
• /
• 2004

본 연구에서는 EPDM 고분자애자의 염무량 변화(salt:l0g, 25g, 50g, deionized water: 1000g)에 따른 표면방전과 환경적인 변화(salt fog 및 clean fog 그리고 raim)에 대한 누설전류 파형의 결과를 알아보았다. 기본파 및 3고조파 그리고 5고조파의 변화양상을 과전초기로부터 섬락시에 이르기까지 나타내었다. 표면열화의 진단기법을 개발하기위해서 누설전류파형의 주파수 스펙트럼을 이용하였고, 고분자애자의 표면열화에대한 환경적인 영향(clean fog, salt fog, rain)을 연구 하였다. 염분량의 변화시 기본파에 대한 저주파 고조파인 3고조파 및 5고조파에 대한 백분율(왜곡도)의 변화를 이용하여 표면 열화상태 및 정도를 정량화(a standard capacity)하여 나타내었다. 기본파에 대한 고조파 백분율인 왜곡율은 고분자 애자의 표면조건을 평가하는데 필요한 지시자라는 사실을 알 수 있었다.

• Archives of Pharmacal Research
• /
• 제21권5호
• /
• pp.549-554
• /
• 1998

Tissue factor (TF), a principal initiator of the veertebrate coagulation cascade, is expressed in organ tissues, cells and blood. TF is konwn to be induced in endothelial cells, monocytes and macrophages by inflammatory stimuli and in many pathologic conditions. By using the modified method for in vido TF activity assay, we found that turpentine oil injection as an inflamatory stimulus also induced the TF activity in lung and brain tissues of rats. And the age-related increase in Tf activity was observed in healthy rat brain tissue.

• 한국약용작물학회지
• /
• 제21권1호
• /
• pp.1-6
• /
• 2013

Buckwheat (Fagopyrum esculentum) has been known for having strong anti-oxidant, anti-mutagenic, and anti-carcinogenic activities. The free radical theory of aging, also known as the oxidative stress theory of aging, claims that cellular oxidative damage accumulated with time is a major causal factor of aging. In the present study, we investigated the effect of buckwheat extracts on resistance to oxidative stress and aging using Caenorhabditis elegans as a model system. Survival under an oxidative-stress condition induced by paraquat increased markedly following 500mg/L buckwheat extracts treatment, suggesting lower cellular oxidative damage by buckwheat extracts. A lifespan assay also revealed that treatment of buckwheat extracts significantly extended both the mean and maximum lifespan in C. elegans. Interestingly, this lifespan-extension by buckwheat extracts was not accompanied by reduced fertility. These findings suggest that buckwheat extracts can confer longevity phenotype to C. elegans through its strong anti-oxidant activity and support the aging theory which emphasizes a pivotal role of oxidative stress during aging.

• The Korean Journal of Physiology and Pharmacology
• /
• 제22권5호
• /
• pp.467-479
• /
• 2018

The aging process induces a plethora of changes in the body including alterations in hormonal regulation and metabolism in various organs including the heart. Aging is associated with marked increase in the vulnerability of the heart to ischemia-reperfusion injury. Furthermore, it significantly hampers the development of adaptive response to various forms of conditioning stimuli (pre/post/remote conditioning). Aging significantly impairs the activation of signaling pathways that mediate preconditioning-induced cardioprotection. It possibly impairs the uptake and release of adenosine, decreases the number of adenosine transporter sites and down-regulates the transcription of adenosine receptors in the myocardium to attenuate adenosine-mediated cardioprotection. Furthermore, aging decreases the expression of peroxisome proliferator-activated receptor gamma co-activator 1-alpha ($PGC-1{\alpha}$) and subsequent transcription of catalase enzyme which subsequently increases the oxidative stress and decreases the responsiveness to preconditioning stimuli in the senescent diabetic hearts. In addition, in the aged rat hearts, the conditioning stimulus fails to phosphorylate Akt kinase that is required for mediating cardioprotective signaling in the heart. Moreover, aging increases the concentration of $Na^+$ and $K^+$, connexin expression and caveolin abundance in the myocardium and increases the susceptibility to ischemia-reperfusion injury. In addition, aging also reduces the responsiveness to conditioning stimuli possibly due to reduced kinase signaling and reduced STAT-3 phosphorylation. However, aging is associated with an increase in MKP-1 phosphorylation, which dephosphorylates (deactivates) mitogen activated protein kinase that is involved in cardioprotective signaling. The present review describes aging as one of the major confounding factors in attenuating remote ischemic preconditioning-induced cardioprotection along with the possible mechanisms.

• 동의생리병리학회지
• /
• 제24권4호
• /
• pp.533-542
• /
• 2010

Skin aging is a natural phenomenon. There are internal and external factors of skin aging. The internal factor of skin aging is from the wearing down of the body over time. The external factors are more noticeable from habits such as smoking, excessive alcohol, malnutrition, and extended exposure to UV rays. Completely stopping skin from aging is impossible but one can slow down and treat external signs of skin aging. In western medicine, the following methods are used to reduce the appearance of skin aging: applying lotions and creams containing ingredients such as fruit acid, antioxidants, plant exracts, depigmentation, moisturizer, retinoids, and sun block; botulinum toxin injections; chemical peels, laser and other painful methods remove the top layer of skin to promote new skin growth; fillers are injected to increase soft tissue growth; surgery. In oriental medicine, the following methods are used: acupuncture into facial muscles which stimulates acupuncture point; applying topical treatments and cosmetics containing herbs are effective of preventing skin aging and wrinkles. Above all thing, medicine that helps maintain essence and blood in the skin can be fundamental.

• Journal of Veterinary Science
• /
• 제21권1호
• /
• pp.7.1-7.13
• /
• 2020

Aging triggers cellular and molecular alterations, including genomic instability and organ dysfunction, which increases the risk of disease in mammals. Recently, due to the markedly growing number of aging dogs in the world, as much as 49% in total number of pet dogs, it is necessary to improve and maintain their quality of life by understanding of the biological effects of aging. Therefore, the aim of this study was to determine specific biomarkers in aging dogs as a means of defining a set of hematological/biochemical biomarkers that influence the aging process. Blood samples were collected from younger (1-3 years) and older (7-10 years) dogs of middle/large size. The hematological/biochemistry analysis was performed to evaluate parameters significantly associated with age. Enzyme-linked immunosorbent assay was used to target growth hormone (GH)/insulin growth factor-1 (IGF-1), one of the main regulators of the aging process. Declining levels of total protein and increased levels of glucose in young dogs was observed regardless of their body size. Notably, a significantly high concentration of GH and IGF-1 in the younger dogs compared to the older dogs was found in middle/large-sized dogs. GH and IGF-1 were also found at significantly high levels in large-sized dogs compared to middle-sized dogs, suggesting a similar trend to that of elderly humans. Consequently, glucose, total protein, GH, and IGF-1 were identified as potential biomarkers for regulating the aging process in large/middle-sized dogs. These findings provide an invaluable insight into the mechanism of aging for the field of aging research.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.710-713
• /
• 2003

The wall charge is major factor to determine the discharge characteristics. The minimum sustain voltage related to the wall charge decay were investigated as a function of aging time in AC plasma display panel. For the long time scale, the wall charge decay time is dependent on the aging time. The inverse time scale of the wall charge decay has the maximum value at around 3 hours aging time and then fell down.

• KIEE International Transactions on Power Engineering
• /
• 제5A권1호
• /
• pp.40-45
• /
• 2005

Substation facilities have become extremely large and complex parts of electric power systems. The development of condition monitoring and diagnosis techniques has been a very significant factor in the improvement of substation transformer security. This paper presents a method to analyze the cause, the degree, and the aging process power transformers by the Self Organizing Map (SOM) method. Dissolved gas data were non-linearly transformed by the sigmoid function in SOM that works much the same way as the human decision making process. The potential for failure and the degree of aging of normal transformers are identified by using the proposed quantitative criterion. Furthermore, transformer aging is monitored by the proposed criterion for a set of transformers. To demonstrate the validity of the proposed method, a case study is performed and its results are presented.

• Biomolecules & Therapeutics
• /
• 제30권6호
• /
• pp.490-500
• /
• 2022

Aging is defined as physiological dysfunction of the body and a key risk factor for human diseases. During the aging process, cellular senescence occurs in response to various extrinsic and intrinsic factors such as radiation-induced DNA damage, the activation of oncogenes, and oxidative stress. These senescent cells accumulate in many tissues and exhibit diverse phenotypes, such as resistance to apoptosis, production of senescence-associated secretory phenotype, cellular flattening, and cellular hypertrophy. They also induce abnormal dysfunction of the microenvironment and damage neighboring cells, eventually causing harmful effects in the development of various chronic diseases such as diabetes, cancer, and neurodegenerative diseases. Thus, pharmacological interventions targeting senescent cells, called senotherapeutics, have been extensively studied. These senotherapeutics provide a novel strategy for extending the health span and improving age-related diseases. In this review, we discuss the current progress in understanding the molecular mechanisms of senotherapeutics and provide insights for developing senotherapeutics.