• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.403-409
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• 2010

Saccharomyces cerevisiae Hsp30 is a plasma membrane heat shock protein that is induced by various environmental stress conditions. However, the functional role of Hsp30 during diverse environmental stressors is not presently known. To gain insight into its function during thermal stress, we have constructed and characterized a ${\Delta}hsp30$ strain during heat stress. $BY4741{\Delta}hsp30$ cells were found to be more sensitive compared with BY4741 cells, when exposed to a lethal heat stress at $50^{\circ}C$. When budding yeast is exposed to either heat shock or weak organic acid, it inhibits Pma1p activity. In this study, we measured the levels of Pma1p in mutant and Wt cells both during optimal temperature and heat shock temperature. We observed that $BY4741{\Delta}hsp30$ cells showed constitutive reduction of Pma1p. To gain further insights into the role of Hsp30 during heat stress, we compared the total protein profile by 2D gel electrophoresis followed by identification of differentially expressed spots by LC-MS. We observed that contrary to that expected from thermal-stress-induced changes in gene expression, the ${\Delta}hsp30$ mutant maintained elevated levels of Pdc1p, Trx1p, and Nbp35p and reduced levels of Atp2p and Sod1p during heat shock. In conclusion, Hsp30 is necessary during lethal heat stress, for the maintenance of Pma1p and a set of thermal stress response functions.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1045-1059
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• 2021

Various abiotic stressors like drought, salinity, temperature, and heavy metals are major environmental stresses that affect agricultural productivity and crop yields all over the world. Continuous changes in climatic conditions put selective pressure on the microbial ecosystem to produce exopolysaccharides. Apart from soil aggregation, exopolysaccharide (EPS) production also helps in increasing water permeability, nutrient uptake by roots, soil stability, soil fertility, plant biomass, chlorophyll content, root and shoot length, and surface area of leaves while also helping maintain metabolic and physiological activities during drought stress. EPS-producing microbes can impart salt tolerance to plants by binding to sodium ions in the soil and preventing these ions from reaching the stem, thereby decreasing sodium absorption from the soil and increasing nutrient uptake by the roots. Biofilm formation in high-salinity soils increases cell viability, enhances soil fertility, and promotes plant growth and development. The third environmental stressor is presence of heavy metals in the soil due to improper industrial waste disposal practices that are toxic for plants. EPS production by soil bacteria can result in the biomineralization of metal ions, thereby imparting metal stress tolerance to plants. Finally, high temperatures can also affect agricultural productivity by decreasing plant metabolism, seedling growth, and seed germination. The present review discusses the role of exopolysaccharide-producing plant growth-promoting bacteria in modulating plant growth and development in plants and alleviating extreme abiotic stress condition. The review suggests exploring the potential of EPS-producing bacteria for multiple abiotic stress management strategies.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.682-688
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• 2012

This study investigates the stressors of dental hygienists and student hygienists during the bedside training by the medical center type. The survey is based on some dental hygienists who are working for dental college hospitals, general hospitals, dental hospitals and dental clinics in Seoul and Gyeonggi area which the Clinical Practice of dental hygienics students is under way in. Included are the students who are studying dental hygienics at Kyungbok University and have taken the bedside training in dental college hospitals, general hospitals, dental hospitals and dental clinics. A statistical analysis shows the following results using SPSS program. By medical center type, dental hygienists described the clinical practice of students as relatively satisfying. It also found that there is a positive correlation between stress zones, and they feel most stressed in the "Role and Activity" zone. Student hygienists felt relatively satisfied with the bedside training, and there is a positive correlation between stress zones except "Practice". It found students, who have taken the bedside training in all types of medical centers except dental clinics, felt most stressed in "Environment". It also found that students who have taken the bedside training in dental clinics felt most stressed in "Role and Activity". In conclusion, most of the dental hygienists are satisfied with students' clinical practice by pattern of hospital. Positive correlation was shown between stress factors. Behavior and attitude and ideal and value are high in stress in college dental hospitals, role and activity and treatment fields are high in stress in dental hospital, and interpersonal relationships are high in stress in dental clinics.

• Research in Community and Public Health Nursing
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• v.10 no.2
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• pp.387-399
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• 1999

The purpose of this study is to identify the relationships of job stressor. coping strategies. and stress responses of manufactoring workers. Data were collected through self-reported questionnaires from 262 of the manufacturing workers in a local electronic company from July to August. 1999. For data analysis. Cronbach's a. Factor Analysis. Descriptive statistics. ANOVA. and Pearson's correlation coefficient with SPSS/PC+ 7.5 version program were used. The results were as follows: 1. Regard to the stress responses and coping strategies by sociodemographic variables. 'the overall stress responses' showed significant differences by sex. age. marrital state. The use of 'control coping strategy' showed significant differences by sex and the type of work. The use of 'avoid coping strategy' showed significant differences by sex. age. married state. year of career. and income. 2. The average scores of 'the job characteristics and participation in decision making factor'. 'the physical environmental factor'. and 'the role and leadership factor' were 2.66. 2.59. 2.59 in order. The average scores for 'the avoid coping strategy' and 'the control coping strategy' were 3.03. 2.97. The average scores for 'the overall. psychosoical. and physical stress responses' were 2.18. 2.18. 2.23. 3. The 'control coping strategy' was negatively related to 'the job characteristics and participation in decision making factor'. 'the role and leadership factor'. 'the psychosocial stress responses'. and 'the overall responses'. 'The control coping strategy' was positively related to all of 'the job stressors'. 'the physical stress responses', and' the overall stress responses'. 'The physical environment factor' was positively related to all of 'the stress reponses'. 'the role and leadership factor'. and 'the job characteristics and participation in decision making factor'. According to the results of this study, the suggestions were as follows: 1. The coping strategies of manufacturing workers in the specific job stress situation should be considered to future studies. 2. In order to applying the stress management program in the workplace. The organizational intervention focused on 'the job characteristics and participation in decision making' will be needed. 3. To support and use of 'control coping strategy' of the workers. the organizational efforts should be required.

• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.450-458
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• 2015

The heat shock proteins (Hsps), one of the most highly conserved groups of proteins, play crucial roles in protecting cells against environmental stressors, such as temperature, salinity, heavy metals and pathogenic bacteria. The glutathione S-transferases (GST) have important role in detoxification of oxidative damage, environmental chemicals and environmental stress. The purpose of this study is to investigate the gene expression of Hsp70 and GST on change of temperature and salinity in Mytilus coruscus. The M. coruscus was cultured in incubator of separate temperature and salinity (8, 20, $30^{\circ}C{\times}20$‰, 25‰, 30‰) for 28 days. Ten individuals in each group were selected after each 14 and 28 days exposure. Results that the expression of Hsp70 mRNA was no significant changed in M. coruscus exposed to temperature ($8^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$) and salinity (20‰, 25‰, 30‰) for 14 days. Whereas the expression of Hsp70 mRNA was increased in exposure to temperature $30^{\circ}C$ and salinity (20‰, 25‰, 30‰) for 28 days. The expression of GST mRNA was increased in exposure to temperature $30^{\circ}C$, salinity (25‰, 30‰) for 14 days and temperature ($8^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$), salinity (20‰, 25‰, 30‰) for 28 days. These results suggest that Hsp70 and GST were played roles in biomarker gene on the thermal and salinity stress.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.477-486
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• 2017

This review provides an overview of dietary nucleotides as an alternative to in-feed antibiotics for weaning pigs. Dietary nucleotides are composed of DNA or RNA molecules and are normally contained in protein-rich feed ingredient, brewer's yeast, yeast extract, and milk. Weaning pigs are suffering from several stresses, such as environmental challenges (i.e. crowding, transportation, and feeding). Such stressors can damage the intestinal epithelium and cause an invasion by Escherichia coli, secondary inflammatory responses, and post weaning diarrhea. To overcome weaning disorder, people often use antibiotics which reduce symptoms and boost growth performance. However, since antibiotics were banned due to concerns of antibiotic resistant bacteria, researchers are studying alternative materials to antibiotics. Dietary nucleotides are one of the alternative materials for replacing antibiotics and can be used in abnormal conditions, such as weaning diarrhea, low digestibility, and disease condition. Nucleotides have substances that have important roles in cell division and cell growth, affecting growth performance, intestinal condition, and immunological effect at the weaning stage. However, nucleotides' composition is very different between sources and this aspect makes it difficult to utilize nucleotides at the weaning stage. Therefore, this review paper focuses on i) the characteristics and functions of dietary nucleotides and ii) the effect of dietary nucleotides on the growth performance and immune system of pigs.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2005.04a
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• pp.53-60
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• 2005

Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting $1\%$ of the population above the age of 65 and is characterized by a selective loss of dopaminergic neurons in the substantia nigra pars compacta. Although the underlying cause of dopaminergic cell death or the mechanism by which these cells degenerate is still not clearly understood, oxidative stress, mitochondrial dysfunction, and protein misfolding are thought to play important roles in the dopaminergic degeneration in PD. Tetrahydrobiopterin (BH4) is synthesized exclusively in the monoaminergic, including dopaminergic, cells and serves as an endogenous and obligatory cofactor for syntheses of the potential oxidative stressors dopamine and nitric oxide. In addition to its contribution toward the syntheses of these two potentially toxic molecules, BH4 itself can directly generate oxidative stress. BH4 undergoes oxidation during the hydroxylation reaction as well as nonenzymatic autooxidation to produce hydrogen peroxide and superoxide radical. We have previously suggested BH4 as an endogenous molecule responsible for the dopaminergic neurodegeneration. BH4 exerts selective toxicity to dopamine-producing cells via generation of oxidative stress, mitochondrial dysfunction, and apoptosis. BH4 also induces morphological, biochemical, and behavioral characteristics associated with PD in vivo. BH4 as well as enzyme activity and gene expression of GTP cyclohydrolase I, the rate-limiting enzyme in BH4 synthesis pathway, are readily upregulated by cellular changes such as calcium influx and by various stimuli including stress situations. This points to the possibility that cellular availability of BH4 might be increased in aberrant conditions, leading to increased extracellular BH4 subsequent degeneration. The fact that BH4 is specifically and endogenously synthesized in dopaminergic cells, Is readily upregulated, and generates oxidative stress-related cell death provides physical relevance of this molecule as an attractive candidate with which to explain the mechanism of pathogenesis of PD.

• Journal of Plant Biotechnology
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• v.31 no.4
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• pp.313-317
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• 2004

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases produced by a variety of cell type, and have a fundamental role in the degradation and remodeling of extracellular matrix. In this study, we screened the secretion of MMPs in leaves of different developmental stages and in response to environmental stress using tobacco. Compare with fully maturing leaves and older leaves, the rate of MMPs activity was high in expanding and younger leaves. It is tempting to speculate that MMPs may be involved in tissue modeling, which must occur during leaf expansion. The MMPs activity in tobacco leaves grown in the presence of stressors showed a significantly increase at salinity treatment and pathogen infection. The MMPs activity in salinity and pathogen treatment increased respectively, by 1.2- and 1.5-fold with respect to the control. These results suggest that MMPs may be involved in plant defence against adverse environment and pathogenic infection.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.1
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• pp.33-37
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• 2013

Autophagy is a degradation process that acts in response to environmental stressors. Recently, autophagy has been detected in normal term, preeclamptic and intrauterine growth-restricted placentas. The object of this work was to investigate the presence of autophagy in first trimester voluntary interruption of pregnancy placental villi by the expression of autophagy-related proteins, light chain 3 (LC3), and Beclin-1. In first trimester placental villi laser scanning confocal microscopy (LSCM) analysis revealed LC3 and Beclin-1 immunoreactivity prevalently located in villous cytotrophoblasts. Using LSCM, LC3, and Beclin-1 were localized to the cytoplasm of the trophoblast layer in human full-term placentas. Beclin-1 expression and LC3 activation were confirmed by western blotting. These data emphasize that autophagy activation is different among cytotrophoblasts and syncytiotrophoblasts depending on the gestational age and thus we speculate that autophagy might play a prosurvival role throughout human pregnancy.

• Journal of Korean Home Economics Education Association
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• v.24 no.3
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• pp.209-223
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• 2012

The purpose of this study is to investigate the influential factors which is related to stress among the children from marrried-immigrant families. The cultural adjustment factor explored as the most affective factor to the children from multi-cultural families. Associated stress with the cultural adjustment, stress which is related to Korean ability presented as the most problematic one. As the conflict related to internalized problems increased as the stress also increased. However, as social support increased as the degree of stress seems to be decreased. For those children, schools work as the safe place compare to the other social environment. Therefore, it would be beneficial to redirect the role and the function of schools for the children from the married-immigrnat families. Various educational opportunity, which is not limited to teach Korean and Korean culture, should be offered to the children as to improve his/her self-esteem.