• Fisheries and Aquatic Sciences
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• v.5 no.4
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• pp.263-270
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• 2002

The Pacific oysters, Crassostrea gigas, were stressed with different concentrations of benzo(a) pyrene and depurated to determine the hemocyte lysosomal membrane stability and hydrolytic enzymatic activity as a biomarker candidate to the chemical, using NRR (neutral red retention) and API ZYM System, respectively. The membrane damage measured as NRR decrease was significant with the increase of chemical concentration and exposure time (P<0.05), providing a possible tool for biomarker. Interestingly, the control showed intrinsic stress probably due to captive life in the laboratory, and a recovering trend was also found during the depuration. The benzo(a)pyrene-exposed oysters showed increased enzyme activities in alkaline phosphatase, esterase (C4), acid phosphatase, naphthol-AS-BI-phospho­hydrolase, $\beta$-galactosidase, $\beta$-glucuronidase, and N-acetyl- $\beta$-glucosaminidase. Of them, only two enzymes, acid phosphatase and alkaline phosphatase, showed some potential available for the generation of enzymatic biomarker in the oyster. The results are suggestive of the potential availability of the cellular and enzymatic properties as a biomarker. However, considering that a robust biomarker should be insensitive to natural stress coming from normal physiological variation, but sensitive to pollutants, a concept of intrinsic stress the animal possesses should be taken into consideration. This reflects the necessity of further research on the intrinsic stress affecting the cellular and enzymatic properties of the chemical­stressed oysters prior to using the data as a biomarker.

• Toxicological Research
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• v.14 no.4
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• pp.515-523
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• 1998

Oxidative stress by reactive oxygen species (ROS) damages cellular DNA, RNA, proteins, lipids and others causing various diseases such as cancer, arthritis, and heart diseases. 8-Hydroxyguanine (8-OHG) is one of the products formed from DNA or RNA damaged by ROS. Since high amounts of 8-OHG can be excreted in urine, it may serve as a potential biomarker indicating the level of oxidative damage to nucleic acids. Residents in industrial area with severe air pollution are expected to be affected by higher level of oxidative stress from pollutants like polyaromatic hydrocarbons (PAHs), etc. Smokers are also expected to be damaged by higher level of oxidative stress from cigarette smoke components like PAHs than non-smokers. To examine if the determination of the urinary concentration of 8-OHG could be used as exposure biomarker for the oxidative stress caused by air-pollutants, this study was performed to determine and compare the urinary concentrations of 8-OHG in smokers and non-smokers, or non-polluted area residents and polluted area residents. Urine samples were collected and purified by a strong cation exchange and cellulose partition column, then analyzed by HPLC with electrochemical detector at 600 ㎷ potential. Concentrations of urinary 8-OHG in non-smokers and smokers of Seoul area college male students were determined as 15.12$\pm$9.68 (ng/mg creatinine) and 34.72$\pm$11.72 (ng/mg creatinine), respectively, showing significantly higher level of 8-OHG in smokers than in non-smokers. Urine samples of elementary school students were collected from Sokcho area, which is known to be non-polluted, and 3 representative polluted areas; Yocheon industrial area, Ulsan urban and Ulsan industrial area. The concentrations of 8-OHG in these samples were 12.42$\pm$8.27 (ng/ mg creatinine, Sokcho), 22.55$\pm$9.12 (ng/mg creatinine, Yocheon), 17.41$\pm$2.30 (ng/mg creatinine, Ulsan urban), 55.04$\pm$39.73 (ng/mg creatinine, Ulsan industrial). Thus, samples from polluted area tend to have higher level of 8-OHG and the levels of Yocheon and Ulsan industrial area were significantly higher than that of Sokcho area. The results indicate that the residents of polluted industrial area or smokers are more severely exposed to oxidative stress probably caused by air pollutants like PAHs. Thus, the determination of urinary 8-OHG concentration could be used as biomarker for the extent of body exposure to oxidative stress caused by various pollutants.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2006.05a
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• pp.89-90
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• 2006

• Ocean and Polar Research
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• v.30 no.1
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• pp.109-117
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• 2008

Application of biomarkers for assessing marine environmental health risk is a relatively new field. According to the National Research Council and the World Health Organization, biomarkers can be divided into three classes: biomarkers of exposure, biomarkers of effect, and biomarkers of susceptibility. In order to assess exposure to or effect of the environmental pollutants on marine ecosystem, the following set of biomarkers can be examined: detoxification, oxidative stress, biotransformation products, stress responses, apoptosis, physiological metabolisms, neuromuscular responses, reproductions, steroid hormones, antioxidants, genetic modifications. Since early 1990s, several biomarker research groups have developed health indices of marine organisms to be used for assessing the state of the marine environment. Biomarker indices can be used to interpret data obtained from monitoring biological effects. In this review, we will summarize Health assessment Index, Biomarker Index, Bioeffect Assessment Index and Generalized Linear Model. Measurements of biomarker responses and development of biomarker index in marine organisms from contaminated sites offer great a lot of information, which can be used in environmental monitoring programs, designed for various aspects of ecosystem risk assessment.

• Tuberculosis and Respiratory Diseases
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• v.85 no.3
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• pp.221-226
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• 2022

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation due to chronic airway inflammation and destruction of the alveolar structure from persistent exposure to oxidative stress. The body has various antioxidant mechanisms for efficiently coping with such oxidative stress. The nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) is a representative system. Dysregulation of the Nrf2-ARE pathway is responsible for the development and promotion of COPD. Furthermore, COPD severity is also closely related to this pathway. There has been a clinical impetus to use Nrf2 for diagnostic and therapeutic purposes. Therefore, in this work, we systematically reviewed the clinical significance of Nrf2 in COPD patients, and discuss the value of Nrf2 as a potential COPD biomarker.

• Korean Journal of Veterinary Research
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• v.55 no.4
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• pp.247-252
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• 2015

Exercise is one of the most common stressors in horses. Although various physiological parameters such as cortisol respond to exercise, there is no reliable parameter for the measurement of exercise-induced stress in sport horses. This study was performed to discover a new biomarker with high sensitivity for exercise-induced stress. The expression of fos mRNA was increased more than 10-fold in horse blood samples collected after an hour of exercise, as compared with before the exercise. The plasma cortisol levels were also increased after the exercise, but only by about two-fold. The fos mRNA levels were well-correlated with plasma cortisol concentrations. These findings suggest that fos mRNA expression in blood may be useful for the measurement of exercise-induced stress in horses.

• Journal of Korean Academy of Nursing
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• v.48 no.2
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• pp.208-220
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• 2018

Purpose: The aim of this study was to analyze the effects of neurofeedback training for reducing stress and enhancing self-regulation in late adolescence to identify the possibility of use for nursing intervention. Methods: A nonequivalent control group pre-post quasi-experimental design was used. Participants were 78 late adolescents assigned to the experimental group (n=39) that received the neurofeedback training and the control group (n=39). Data were collected on heart rate variability (HRV) and skin conductance level (SCL) to assess stress-biomarker response. The questionnaire contained 164 items from: Positive and Negative Affect Schedule (PANAS), Symptom Checklist-90-Revised (SCL-90-R) and Self-regulatory Ability scale. The neurofeedback training was based on the general adaptation syndrome and body-mind medicine. The intervention was conducted in a total of 10 sessions for 30 minutes per session with high-beta, theta and sensory motor rhythm training on scalp at central zero. Results: There were significant difference in standard deviation of normal to normal interval (p=.036) in HRV and SCL (p=.029) of stress-biomarker response between the two groups. Negative affect (p=.036) in PANAS and obsessive compulsive (p=.023) and depression (p<.001) in SCL-90-R were statistically significant. Self-regulation mode (p=.004) in self-regulation ability scale showed a significant difference between the two groups. Conclusion: The results indicated that the neurofeedback training is effective in stress-biomarkers, psychoemotional stress response and self-regulation. Therefore, neurofeedback training using neuroscientific approach based on brain-mind-body model can be used as an effective nursing intervention for late adolescents in clinics and communities for effective stress responses.

• Journal of Preventive Medicine and Public Health
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• v.49 no.5
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• pp.260-274
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• 2016

Objectives: Previous epidemiological studies about oxidative stress and depression are limited by hospital-based case-control design, single-time measurements of oxidative stress biomarkers, and the small number of study participants. Therefore, in this study, we analyzed the association between biomarker of oxidative stress and depressive symptom scores using repeatedly measured panel data from a community-dwelling elderly population. Methods: From 2008 to 2010, a total of 478 elderly participants residing in Seoul, Korea, were evaluated three times. Participants underwent the Korean version of the Short Form Generic Depression Scale (SGDS-K) test for screening depression, and urinary malondialdehyde (MDA) levels were measured as an oxidative stress biomarker. We used a generalized estimating equation with a compound symmetry covariance structure to estimate the effects of oxidative stress on depressive symptom scores. Results: A two-fold increase in urinary MDA concentration was significantly associated with a 33.88% (95% confidence interval [CI], 21.59% to 47.42%) increase in total SGDS-K scores. In subgroup analyses by gender, a two-fold increase in urinary MDA concentration was significantly associated with increased SGDS-K scores in both men and women (men: 30.88%; 95% CI, 10.24% to 55.37%; women: 34.77%; 95% CI, 20.09% to 51.25%). In bivariate analysis after an SGDS-K score ${\geq}8$ was defined as depression, the third and the fourth urinary MDA quartiles showed a significantly increased odds ratio(OR) of depression compared to the lowest urinary MDA quartile (third quartile OR, 6.51; 95% CI, 1.77 to 24.00; fourth quartile OR, 7.11; 95% CI, 1.99 to 25.42). Conclusions: Our study suggests a significant association between oxidative stress and depressive symptoms in the elderly population.

• Perspectives in Nursing Science
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• v.11 no.2
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• pp.87-93
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• 2014

Purpose: The use of salivary biomarkers for stress research is increasing based on the convenience of collection, affordability and scientific merit. This short review provides an overview of the state of the science of salivary biomarkers utilized in research related to stress. Methods: An integrative review was conducted. Results: The trend of utilizing salivary biomarkers in stress research was reviewed, specifically, focusing on the use of endocrine and inflammatory biomarkers incorporated in previous stress research. Then, a review of sampling procedures for salivary biomarkers and the analytic methods is provided. Finally, a discussion on the strengths and areas for improvement in the use of salivary biomarkers in stress research is included. Conclusion: Salivary biomarkers as an alternative to blood biomarkers are increasingly being recognized as a legitimate source for analyzing the stress response in humans.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.25-26
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• 2003

There is increasing interest in the involvement of transcription factors, such as of the transcription factor NF-kB (nuclear factor-kB), in the pathogenesis of various diseases. The involvement ofNF-kB is especially of interest as it is activated by oxidative stress and its activation can be modulated by antioxidant compounds. (omitted)