• Korean Journal of Health Education and Promotion
• /
• v.3 no.1
• /
• pp.113-128
• /
• 2001

The purpose of this study is to examine the prevalence and correlates of three types of risk-taking behavior among high school students in Korea in a cross-sectional national sample. A sample of 636 male and 622 female high school students is analyzed using descriptive statistics and logistic regression. Three types of risk-taking behavior are examined: drinking alcohol, smoking, and premarital sex. The results are as follows: Forty-three percent of students in the sample have ever drunk alcohol, 32% have ever smoked, 11% have experience premarital sex. Risk-taking behavior is more prevalent among boys than among girls. Boys and girls in Seoul are much more likely to have experienced three types of risk-taking behavior. Not having two parents in the family and having lived away from immediate family increase the likelihood of some risk-taking behavior. Students who have a friend with premarital sexual experience are much more likely to have experienced premarital sex themselves. Among sexually active students, having multiple sexual partners is common and prevalence of condom use is low. Reproductive health education at school has no effect on students' sexual behavior. The prevalence of risk-taking behavior among adolescent in Korea is likely to rise in the future. Substantial proportion of adolescents are exposed to the risks of STDs and substantial proportion of adolescent girls risk premarital pregnancy. Current health education programs are inadequate in protecting students from risk-taking behavior. Students whose families do not include both parents and students who live away from their immediate families need special programs to protect them from risk-taking behavior.

• Journal of Food Hygiene and Safety
• /
• v.21 no.4
• /
• pp.258-262
• /
• 2006

To investigate additive effects of endocrine disruptors, we have histopathologically studied the exchanges of the reproductive organ to ovariectomized ICR mice. Female ICR mice were ovariectomized and then treated with endocrine disruptors after two weeks. Macroscopic exchanges, which were body weight, feed and water intake, of all groups were not seen during experiment period. Histopathological changes of uterine epithelial cells, vaginal epithelial cells, mammary glands and the diameter in uterine tubles were observed. In the results, the histopathological sensitivity to endocrine disruptors effect was more seen to the vaginal epithelial cell height than others. The additive estrogenic effects of endocrine disruptors, which were combinations of DEHP, DBP and BPA, were seen with E2 and BPA treatments. These results offers a sysmatic and mechanistically informative approach to assessing estrogenicity. It provides a useful profile of activity using a reasonable amount of resources and is compatible with the study of individual chemicals as well as the investigation of interactions among combinations of chemicals.

• BMB Reports
• /
• v.52 no.2
• /
• pp.157-162
• /
• 2019

Our previous study found that two novel cancer-related genes, PRR11 and SKA2, constituted a classic gene pair that was regulated by p53 and NF-Y in lung cancer. However, their role and regulatory mechanism in breast cancer remain elusive. In this study, we found that the expression levels of PRR11 and SKA2 were upregulated and have a negative prognotic value in breast cancer. Loss-of-function experiments showed that RNAi-mediated knockdown of PRR11 and/or SKA2 inhibited proliferation, migration, and invasion of breast cancer cells. Mechanistic experiments revealed that knockdown of PRR11 and/or SKA2 caused dysregulation of several downstream genes, including CDK6, TPM3, and USP12, etc. Luciferase reporter assays demonstrated that wild type p53 significantly repressed the PRR11-SKA2 bidirectional promoter activity, but not NF-Y. Interestingly, NF-Y was only essential for and correlated with the expression of PRR11, but not SKA2. Consistently, adriamycin-induced (ADR) activation of endogenous p53 also caused significant repression of the PRR11 and SKA2 gene pair expression. Notably, breast cancer patients with lower expression levels of either PRR11 or SKA2, along with wild type p53, exhibited better disease-free survival compared to others with p53 mutations and/or higher expression levels of either PRR11 or SKA2. Collectively, our study indicates that the PRR11 and SKA2 transcription unit might be an oncogenic contributor and might serve as a novel diagnostic and therapeutic target in breast cancer.

• Toxicological Research
• /
• v.35 no.2
• /
• pp.119-129
• /
• 2019

As the use of cosmetics has greatly increased in a daily life, safety issues with cosmetic ingredients have drawn an attention. Drometrizole [2-(2'-hydroxy-5'-methylphenyl)benzotriazole] is categorized as a sunscreen ingredient and is used in cosmetics and non-cosmetics as a UV light absorber. No significant toxicity has been observed in acute oral, inhalation, or dermal toxicity studies. In a 13-week oral toxicity study in beagle dogs, No observed adverse effect level (NOAEL) was determined as 31.75 mg/kg bw/day in males and 34.6 mg/kg bw/day in females, based on increased serum alanine aminotransferase activity. Although drometrizole was negative for skin sensitization in two Magnusson-Kligman maximization tests in guinea pigs, there were two case reports of consumers presenting with allergic contact dermatitis. Drometrizole showed no teratogenicity in reproductive and developmental toxicity studies in which rats and mice were treated for 6 to 15 days of the gestation period. Ames tests showed that drometrizole was not mutagenic. A long-term carcinogenicity study using mice and rats showed no significant carcinogenic effect. A nail product containing 0.03% drometrizole was nonirritating, non-sensitizing and non-photosensitizing in a test with 147 human subjects. For risk assessment, the NOAEL chosen was 31.75 mg/kg bw/day in a 13-week oral toxicity study. Systemic exposure dosages were 0.27228 mg/kg bw/day and 1.90598 mg/kg bw/day for 1% and 7% drometrizole in cosmetics, respectively. Risk characterization studies demonstrated that when cosmetic products contain 1.0% of drometrizole, the margin of safety was greater than 100. Based on the risk assessment data, the MFDS revised the regulatory concentration of drometrizole from 7% to 1% in 2015. Under current regulation, drometrizole is considered to be safe for use in cosmetics. If new toxicological data are obtained in the future, the risk assessment should be carried out to update the appropriate guidelines.

• Journal of Preventive Medicine and Public Health
• /
• v.54 no.4
• /
• pp.275-283
• /
• 2021

Objectives: The workplace is an ideal place for encouraging health-promoting behaviors. Therefore, the aim of the present study was to determine the effect of an empowerment program on the health-promoting behaviors of women workers. Methods: This randomized clinical trial was conducted with 80 women workers employed at a food packaging facility in 2020. The subjects were selected using convenience sampling and were classified into intervention and control groups using block randomization. An empowerment program for women workers was conducted across 6 sessions based on an empowerment model. Data collection tools included a demographic questionnaire and the Health Promoting Lifestyle Profile-II, which participants completed both before the program and 8 weeks after the last session. Data analysis was performed in SPSS version 16 using descriptive analysis and inferential statistics. Results: There were no significant differences between the 2 groups in various health-promoting behaviors before the program. However, the intervention group's scores for nutrition (34.92±1.09 vs. 27.87±4.23), physical activity (24.40±2.94 vs. 17.40±5.03), stress management (26.35±2.60 vs. 23.05±4.27), spiritual growth (34.02±3.00 vs. 30.22±5.40), interpersonal relationships (30.82±2.38 vs. 27.60±4.61), and health responsibility (31.60±2.71 vs. 28.22±4.59) were significantly higher than the control group's 8 weeks after the program had ended. Moreover, there was a significant difference in the total score of health-promoting behaviors for the intervention group compared to the control group (179.00±9.22 vs. 151.42±20.25, p=0.001). Conclusions: An empowerment program for women workers led to significant improvements in the health-promoting behaviors of the participants. Similar programs can ultimately improve women's health in the workplace.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.17 no.3
• /
• pp.206-218
• /
• 1984

The gonadal development and gametogenesis of shad, Konosirus, punctatus (TEMMINCK et SCHLEGEL) were studied by comparing with various quantitative indices, such as seasonal changes of gonadosomatic index, fatness, egg-diameter composition, first maturing size, and by comparing with histological changes of gonad and gonadotrophs(GTH) in pituitary. The materials were monthly sampled from Dadaepo at the estuary of the Nakdong river in Korea from September, 1982 to October, 1983. The ovary of shad is a pair of sac-shaped organs revered with a fibromuscular capsule and consisting of numerous sacs. The type of testicular structure is lobular type with development of germ cells, mesenchymal tissue on the lobuli. The gonadosomatic index (GSI) is rather low till March, but increases in April and reaches to peak in June in females and May in males. And it suddenly falls in July. The gonads become active on the increase of water temperature and spawning season ends before high water temperature. After spawning, the small oocytes continue to remain as they are untill the growing period next year. The reproductive cycle includes the successive stages of growing from March to April, mature from April to May, ripe and spawning in June, and recovery and resting from July to February next year. In egg-diameter composition of an ovary taken in the spawning season, 2-3 modes were recognized with some batches shown in an ovary. An individual shad spawns twice or more in a month-spawning season. The individual spawning interval is estimated to be ten days or less. Changes of fatness are corelated with those of water temperature that affect on the condition of feeding, but less corelated with spawning. The percentage of mature of female and male fish, are $50\%$ in 17.0-18.0 cm and $100\%$ in 18.0-19.0 cm. GTH cells are activated from growing period and decrease their activity at pre-spawning season with peak activity for mature period.

• Reproductive and Developmental Biology
• /
• v.36 no.4
• /
• pp.261-267
• /
• 2012

The technique of SCNT is now well established but still remains inefficient. The in vitro development of SCNT embryos is dependent upon numerous factors including the recipient cytoplast and karyoplast. Above all, the metaphase of the second meiotic division (MII) oocytes have typically become the recipient of choice. Generally high level of MPF present in MII oocytes induces the transferred nucleus to enter mitotic division precociously and causes NEBD and PCC, which may be the critical role for nuclear reprogramming. In the present study we investigated the in vitro development and pregnancy of White-Hanwoo SCNT embryos treated with caffeine (a protein kinase phosphatase inhibitor). As results, the treatment of 10 mM caffeine for 6 h significantly increased MPF activity in bovine oocytes but does not affect the developmental competence to the blastocyst stage in bovine SCNT embryos. However, a significant increase in the mean cell number of blastocysts and the frequency of pregnant on 150 days of White-Hanwoo SCNT embryos produced using caffeine treated cytoplasts was observed. These results indicated that the recipient cytoplast treated with caffeine for a short period prior to reconstruction of SCNT embryos is able to increase the frequency of pregnancy in cow.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.1
• /
• pp.77-82
• /
• 2014

The study aimed to evaluate the potential effects of feeding with phytase transgenic corn (PTC) on organ weight, serum biochemical parameters and nutrient digestibility, and to determine the fate of the transgenic DNA in laying hens. A total of 144 50-week-old laying hens were grouped randomly into 2 treatments, with 8 replicates per treatment and 9 hens per replicate. Each treatment group of hens was fed with diets containing 62.4% non-transgenic conventional corn (CC) or PTC for 16 weeks. The phytase activity for CC was 37 FTU/kg of DM, whereas the phytase activity for PTC was 8,980 FTU/kg of DM. We observed that feeding PTC to laying hens had no adverse effect on organ weight or serum biochemical parameters (p>0.05). A fragment of a poultry-specific ovalbumin gene (ov) was amplified from all tissues of hens showing that the DNA preparations were amenable to PCR amplification. Neither the corn-specific invertase gene (ivr) nor the transgenic phyA2 gene was detected in the breast muscle, leg muscle, ovary, oviduct and eggs. The digestibility data revealed no significant differences between the hens that received the CC- and PTC-based diets in the digestibility of DM, energy, nitrogen and calcium (p>0.05). Phosphorus digestibility of hens fed the PTC-based diet was greater than that of hens fed the CC-based diet (58.03% vs 47.42%, p<0.01). Based on these results, it was concluded that the PTC had no deleterious effects on the organ weight or serum biochemical parameters of the laying hens. No recombinant phyA2 gene was detected in muscle tissues and reproductive organs of laying hens. The novel plant phytase was efficacious in improving the phosphorus digestibility of laying hens.

• Korean Journal of Environmental Biology
• /
• v.27 no.4
• /
• pp.323-333
• /
• 2009

Parabens are alkyl esters of p-hydroxybenzoic acid, which are widely used in foods, cosmetics, and pharmaceutic products as preservatives. Absorbed parabens are metabolized fastly and excreted. Actually human body is exposed to complex mixture of parabens. Safety assessment at various toxicological end points revealed parabens have a little acute, subacute and chronic toxicities. Some reports have argued that as parabens have estrogenic activity, they are associated with the incidence of breast cancer through dermal absorption by cosmetics. There is an inference that antiandrogenic activity of parabens may give rise to a lesion of male reproductive system, but also there is an contrary. At cellular level, parabens may inhibit mitochondrial function of sperms and androgen production in testis, but also there is an contrary. Parabens seem to have little or no toxicity in embryonic development. Parabens can cause hemolysis, membrane permeability change in mitochondria and apoptosis, suggesting cellular toxicity of parabens. Parabens evoked endocrine disruption in several fish species and have toxic effect on small invertebrates and microbes. Therefore, the toxicity of parabens should be considered as a potentially toxic chemical in the freshwater environment. In conclusion, though parabens may be considered as a low toxic chemical, more definite data are required concerning the endocrine disrupting effect of parabens on human body and aquatic animals according to route and term of exposure as well as the residual concentration of parabens.

• Korean Journal of Veterinary Research
• /
• v.34 no.4
• /
• pp.873-880
• /
• 1994

Progesterone catabolizing enzyme, the enzyme $20{\alpha}$-hydroxysteroid deltydrgenase($20{\alpha}$-HSD) is pivotal in the regulation of ovarian function in rodents, which catabolizes progesterone into biologically inactive $20{\alpha}$ hydroxypregn-4-en-3-one($20{\alpha}$-OHP). In this study was carried out the influence of $20{\alpha}$-HSD activity to ovarian function and regulation such as ovulation, formation of corpus luteum, maintenance of estrous cycles and pregnancy, we investigated changes in activities of the splenic macrophages and ovarian histological findings in rat. During the estrous cycles, the ratious of phagocytotic macrophage in splenic adherent cells were highest on the proestrous, but they were lowest on metestrous. During the pregnancy, the ratious of phagocytotic macrophages in splenic adhrent cells were lowest by 1 day and then significantly increased toward the pregnancy, which were highest pregnancy on day 12. On histological findings in rat ovary, the mean number of growing, antral and mature follicles were 15.9(72.9%), 3.4(15.9%), and 2.4(11.2%), respectively. Growing follicles reached to lowest number at diestrus and mature follicle reached to lowest number at metestrus. The numbers of corpus luteums per tissue section of the ovary were 14.4 and the number of normal and atretic follicles were 11.0(76.4%) and 3.4(23.6%), respectively. The number of corpus luteum with vacolated cell were 1.7(11.8%). In this study suggests splenic macrophages are as a source of the substance which maintainer progesterone secretion from luteal cells, and are recognized pass the vessels and reside in the fresh corpora lutea soon after ovulation via inflammatory reactions, and these macrophages are felt to have a stimulatory effect on the formation of cropora lutea. In view of the results include previous report, ovarian $20{\alpha}$-hydroxysteroid dehydrogenase enzyme and splenic macrophages consider play central role in the control and maintenance of estrous cycles and pregnancy, and also applicable to both clinical and research in a wide variety such as control of reproductive system.