• Journal of fish pathology
• /
• v.35 no.1
• /
• pp.77-92
• /
• 2022

Aquaculture development is based on the ideas of increasing production while reducing economic losses. Bacterial diseases are the leading source of fish cases. Citrobacter freundii has been linked to septicemia and mortality all over the world. In the current study, the cause of mortality in O. niloticus was C. freundii MW279218. External hemorrhages were seen on the affected fish, as well as paleness in the liver and kidney congestion. C. freundii MW279218 had a median lethal dosage of 1.5×10⁵ CFU/mL. Zinc oxide and zinc oxide nanoparticles (ZnO-NPs) were tested for their biocidal effectiveness against C. freundii MW279218. The lethal effect of ZnO-NPs for C. freundii MW279218 was 100% when compared to zinc oxide compound, and the inhibition zone width was 2.31.1mm at the highest tested concentrations (70 mg/L) compared to the lowest (35 and 45 mg/L, respectively). Fish were fed three different diets for 28 days: diet 1 (no additives), diet 2 (100 mg of ZnO-NPs/kg of feed), and diet 3 (200 mg of ZnO-NPs/kg of feed). Organs were also collected for histopathology 96 hours after injection (P<0.05). In the groups given 200 mg of ZnO-NPs, there was 10% mortality and 80% RPS. The group fed 100 mg of ZnO-NPs/kg, on the other hand, had 20% mortality and 60% RPS, compared to 50% mortality in the control positive group. Histopathological examinations demonstrated significant alterations in the control positive group and mild lesions in the hepatopancreas of the groups administered 100 mg ZnO-NPs/kg of feed. The groups fed 200 mg of ZnO-NPs/kg diet, on the other hand, showed no histological alterations. ZnO-NPs were found to be effective in the up regulation of both IL-10 and complement 5 immune-related genes.

• The Journal of Korean Society for School & Community Health Education
• /
• v.17 no.1
• /
• pp.59-73
• /
• 2016

Objectives: The working environment affects employees' physical and mental aspects, and has a deep associations with depression. The purposes of this study are to investigate how hazardous environment working experience impacts on depression, to provide rationale and practical implications for reducing depression and drinking. Methods: This study targeted 215 dental hygiene students from 3 universities located in Gyeonggi-do from November 30 to December 4, 2015. We analyzed the data with frequency analysis, descriptive statistics, t-test. One-way ANOVA, Pearson correlation coefficient, Regression analysis by using SPSS. Results: This study showed that experience working in hazardous environments increased depression and alcohol drinking, on the other hand alcohol drinking reduced depression. In addition, experience working in hazardous environments effected on depression indirectly through mediating of drinking, subjective health had not role of Moderating Effects between experience working in hazardous environments and depression. Conclusions: In order to reduce workers' depression and alcohol, the improvements of harmful environment are needed. For this governments and local governments should efforts to support enhancing workplace environment, to develop model of standard work environment, and to change employers' awareness on the harmful environment.

• Journal of Korean society of Dental Hygiene
• /
• v.17 no.1
• /
• pp.49-62
• /
• 2017

Objectives: This study was conducted to suggest the necessity of education about toothpaste usage to infants, preschoolers, and their parents. Also, another purpose is to provide basic data that is necessary for oral health education about accurate cognition and usage of toothpaste. Methods: From October to December 2015, we conducted a survey on parents of 0~4 years old infants and preschoolers about toothpaste usage based on the data of a questionnaire with a total of 505 subjects. The survey questions were composed of general characteristics of infants, preschoolers and their parents, and toothpaste usage. Results: Usage frequency of toothpaste for infants and preschoolers increased with age (p<0.001), and infants and preschoolers in homes with monthly income under 4 million won showed high frequency of toothpaste usage (p<0.001). Toothpaste mouth rinsing of infants and preschoolers increased with age (p<0.001), while on the other hand, toothpaste swallowing decreased (p<0.001). Conclusions: In this study, it was shown that the factors that effect toothpaste usage in infants and preschoolers were age and average monthly income of the family. This suggests the necessity of oral health education to parents about usage of toothpaste in infants and preschoolers.

• Journal of Korean society of Dental Hygiene
• /
• v.17 no.3
• /
• pp.449-463
• /
• 2017

Objectives: The objective of this study was to identify the relationship between emotional labor and occupational stress of the dental hygienists, and the effects of emotional labor on their occupational stress and health problems including depression, anxiety and sleep. Methods: The survey was conducted using the questionnaires about dental hygienists' working in medical institutions in Busan, Gyeongsangnam-do from August 19th and October 7th, 2016. Total of 225 participants were selected for data analyses. Frequency analysis, t-test, ANOVA, Pearson's correlation coefficient analysis, and regression analysis were conducted using SPSS Windows ver. 21.0 program(SPSS Inc., Chicago, IL. USA). Results: The analysis of the factors affecting emotional labor, occupational stress, anxiety, and sleep by participants' characteristics showed that those with higher education level, work position and annual salary had higher emotional labor. In addition, participants who worked 5 days every other week and were responsible for patient consultation had higher emotional labor. The analysis of correlations among emotional labor occupational stress, anxiety, and sleep showed positive correlations between emotional experience and emotional expression, occupational stress and emotional expression, and anxiety and emotional expression. On the other hand, negative correlation was found between anxiety and emotional experience. Regression analysis was conducted to examine the effect of emotional labor on job stress. Emotional labor was a factor affecting job stress and anxiety. Conclusions: In order to improve emotional control and vulnerability to stress among dental hygienists, intra-organizational training opportunities and mental health care strategies are needed. Additional broad-based studies are required to identify the factors affecting the occupational stress and emotional labor and to develop relevant intervention measures.

• Journal of Food Hygiene and Safety
• /
• v.31 no.4
• /
• pp.294-298
• /
• 2016

Natural products are attractive as the source of new drug development. Especially, numerous unknown marine bioresources are an object of attention because the ocean occupies three fourth of the earth. Survival of marine bioresources in extreme environment may induce the production of biological active compounds. As previous study, we examined over 40 specimens of marine sponges collected from Micronesia and screened their anti-proliferative activities in various cancer cell lines. Among them, we investigated Coscinoderma sp.'s activity and mechanism in human colon carcinoma HCT116 and RKO cells. Furthermore, we also used the p53-knockout of HCT116 cells and the p53 loss of RKO cells for elucidating the role of p53. Coscinoderma sp. inhibited cellular viability independently of the p53 status. Therefore, we compared the expression level of cell death-related proteins by Coscinoderma sp. in HCT16 and in HCT116 p53KO cells. Coscinoderma sp. increased p53 level and NOXA levels and induced apoptosis under the condition of p53 existence. On the other hand, Coscinoderma sp. increased p21 and mTOR levels in HCT116 p53KO cells. These results suggest that Coscinoderma sp. induced anti-proliferation effect through different pathway depending on p53 status.

• Toxicological Research
• /
• v.14 no.3
• /
• pp.321-328
• /
• 1998

This study was performed to evaluate the effect of liver damage on toluene metabolism in rats pretreated with carbon tetachloride. Liver damage in rats was induced by administration of 0.1ml of carbon tetrachloride per 100g of body wight intraperitoneally every day for four weeks except the last day before sacrifice. One day before sacrifice, toluene was administered to the animals instead of carbon tetrachloride. Rats were sacrificed at the 1st, the 2nd, the 3rd and the 4th week after the first administration of carbon tetachloride. Based on the histopathological findings, liver weight and serum alanine aminotransferase, the $CCl_4$-preteated group was found to have gradual severe liver damage. Especially the degree of liver injury became increasingly severe throughout the whole course of the experiment. The contnts of hippuric acid in urine lower in the all groups pretreated with $CCl_4$than that of the control. The contents of hepatic cytochrome P450(CYP), benzylalcohol dehydrogenase and benzaldehyde dehydrogenase activities were decreased in $CCl_4$-pretreated rats than those of the control. The $CCl_4$treated animals showed the gradual decreased activities of these enzyme as injection times elapsed. Km values of the benzylalcohol dehydrogenase in pooled liver samples from $CCl_4$-pretreated or control groups were similar. On the other hand, Vmax values of the $CCl_4$-pretreated group was lower than of the control. Therefore, it can be concluded that reduction of the toluene metabolism in damaged rat liver induced with $CCl_4$was due to the inhibition of CYP content, bezylalcohol and benzaldehyde dehydrogenase activities which related with toluene metabolic enzyme system.

• Child Health Nursing Research
• /
• v.4 no.2
• /
• pp.255-264
• /
• 1998

Disease prevention and health promotions are basically needed to be healthy, health education is the most useful mean to accomplish them. Preschool children are being developped, their health problem can effect their health status through their lives. This study was attempted to survey for status of health education of kindergarten for preshoolers and to provide the basic precious data for nursing intervention. The subjects were 51 kidergarten teachers. The data were collected by the questionaires, which consiste of 25 items concerning daily life habits of children and 1 item concerning the problems of health education for preschoolers. The data were analyzed by SAS program. The results of this study are as folleowed ; 1. The most frequently educated subjects were 'adequate and safe play' and 'hand washing', 'walking and running straightly', 'oral hygiene or tooth brushing', 'walking staires'. 2. The most frequently used teaching method was the explaining. 3. The most frequently used instructional method was the pictures. The slide films and OHP was seldomly used media. 4. The most effective teaching method which perceived by the kindergarten teachers was role play . Discuss ion and compensation/reinforcement were comparatively effective method also. 5. The most effective instructional media which perceived by the kindergarten teachers was a real object/model. 6. The problems of health education for preschoolers were 'deficiency of developped health educational programs' and 'inconsistency between parents' education and kindergarten teachers' education', 'deficiency of instructional media'. The other problems were' the knowledge deficit of teachers themselves' and 'the difficulty of measure the effect of education', 'time deficit'. Conclusionally, we have to realize the health of children is the future of our health, and reinforce the health education for preschoolers to accomplish the disease prevention and health promotion.

• Speech Sciences
• /
• v.14 no.2
• /
• pp.43-53
• /
• 2007

The purpose of this study was to observe the effect of eating a raw egg by professional or nonprofessional voice users on their voice quality and the duration of the effect. 20 professional voice users and 20 nonprofessional voice users participated in the experiment and they had gone through stroboscopy to have no vocal or laryngeal diseases. The voice exam was performed three times: before eating a raw egg (1st period), right after eating it (2nd period), and 10 minutes later (3rd period). By using Multi-dimensional Voice Program which is a software of Computerized Speech Lab 4500 as a voice analysis instrument, the authors checked the F0, Jitter, Shimmer, Noise to harmonic ratio (NHR), and Voice Range Profile (VRP). Results showed as follows: Firstly, vocal hygiene was good in 57.5% of the total subjects and was poor in 42.5%. 40% of professional voice users and 75% of nonprofessional voice users hand good quality. 77.5% of the total subjects had the vocal fatigue while 22.5% of the subjects did not. 95% of the professional voice users and 60% of nonprofessional voice users complained the vocal fatigue. 60% of the total subjects reported a subjective vocal symptom. 65.0% professional voice users and 70.0% of nonprofessional voice users reported a voice symptom. From the results above, we suggest that eating a raw egg may lead to imporve voice quality of the professional voice users.

• Journal of the Korea Convergence Society
• /
• v.9 no.12
• /
• pp.81-88
• /
• 2018

Human gingival fibroblast (HGF) is the main cell type existed in periodontium and produces a variety of inflammatory mediators by external stimuli. In this study, the anti-inflammatory activity of Porphyra yezoensis ethanol extract (PYEE) on LPS-PG lipopolysaccharide from Porphyromonas gingivalis activated HGF-1 cell. Up-regulated iNOS and COX-2 expressions by LPS-PG were significantly attenuated by PYEE treatment in a dose-dependent manner. In addition, activated nuclear factor $(NF)-{\kappa}B$ was also dose-dependently inhibited by PYEE treatment. Among upstream signaling molecules, PYEE treatment inhibited phosphorylation of c-Jun $NH_2$-terminal kinase (JNK) but did not give any effect on other molecules. On the other hand, one of phase II enzymes, NAD(P)H:quinone dehydrogenase (NQO)-1, was analyzed due to its anti-inflammatory activity, which was upregulated by PYEE treatment. Consequently, PYEE could be candidates for the prevention and treatment of periodontal diseases.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.5 no.1
• /
• pp.59-67
• /
• 1995

Blood lead assay by $D_2$ lamp background correction method of atomic absorption spectrophotometer(AAS) with wavelength of 283.3 nm is most popular in occupational health practice in Korea. On the other hand, $D_2$ lamp background correction method with wavelength of 217.0 nm is also often used in general chemical analysis for lead assay in general purpose. But both methods have some weakness of background correction which brought direct effect on the results of analysis. Recently blood lead assay with polarized Zeeman effect of AAS was introduced and is now preferred in many laboratory than $D_2$ correction method in blood lead analysis. But still AAS with $D_2$ lamp are widely used in the field of occupational health in Korea. This study compared blood lead assay data with $D_2$ correction methods(283.3 and 217.0 nm) and with that of polarized Zeeman effect correction method to evaluate the validity of 02 correction methods. The results obtained were as follows; 1. Taking the value of polarized Zeeman effect method as reference value of 1.00, the mean relative value of $D_2$ correction method with wavelength of 217.0 nm was 0.92 and that with wavelength of 283.3 nm was 0.90 respectively in the analysis of blood lead whose value were below $20.0{\mu}g/dl$(p<0.001). Both mean values were statistically smaller than polarized Zeeman effect correction method. But in the analysis of blood whose value were between 20.0 to $20.0{\mu}g/dl$, the mean relative value of $D_2$ correction method was 0.96 in both wavelength and did not differ from polarized Zeeman effect method(p<0.001). There was no difference of blood lead between $D_2$ correction method and polarized Zeeman effect method in the analysis of blood lead whose value were over $40.0{\mu}g/dl$. 2. The variations of background correction value in polarized Zeeman effect method were not changed by increase of blood lead, but those in $D_2$ correction methods were increased by the increase of blood lead. While then relative standard deviation(RSD) of data measured by Zeeman effect method were decreased by the increase of blood lead, those by $D_2$ methods were nol differed by the increase of blood lead.