• Toxicological Research
• /
• v.34 no.2
• /
• pp.173-182
• /
• 2018

Valproic acid (VPA) plays a role in histone modifications that eventually inhibit the activity of histone deacetylase (HDAC), and will affect the expressions of genes Pdx1, Nkx6.1, and Ngn3 during pancreatic organogenesis. This experiment was designed to study the effect of VPA exposure in pregnant rats on the activity of HDAC that controls the expression of genes regulating the development of beta cells in the pancreas to synthesize and secrete insulin. This study used 30 pregnant Sprague-Dawley rats, divided into 4 groups, as follows: (1) a control group of pregnant rats without VPA administration, (2) pregnant rats administered with 250 mg VPA on day 10 of pregnancy, (3) pregnant rats administered with 250 mg VPA on day 13 of pregnancy, and (4) pregnant rats administered with 250 mg VPA on day 16 of pregnancy. Eighty-four newborn rats born to control rats and rats administered with VPA on days 10, 13, and 16 of pregnancy were used to measure serum glucose, insulin, DNA, RNA, and ratio of RNA/DNA concentrations in the pancreas and to observe the microscopical condition of the pancreas at the ages of 4 to 32 weeks postpartum with 4-week intervals. The results showed that at the age of 32 weeks, the offspring of pregnant rats administered with 250 mg VPA on days 10, 13, and 16 of pregnancy had higher serum glucose concentrations and lower serum insulin concentrations, followed by decreased concentrations of RNA, and the ratio of RNA/DNA in the pancreas. Microscopical observations showed that the pancreas of the rats born to pregnant rats administered with VPA during pregnancy had low immunoreaction to insulin. The exposure of pregnant rats to VPA during pregnancy disturbs organogenesis of the pancreas of the embryos that eventually disturb the insulin production in the beta cells indicated by the decreased insulin secretion during postnatal life.

• The Korean Journal of Pesticide Science
• /
• v.12 no.4
• /
• pp.357-362
• /
• 2008

In order to survey the residual characteristics of pesticides and assess their safeties in the agricultural products from markets, the agricultural products were purchased from the wholesale and traditional markets in Cheongju and Jeonju and analyzed the pesticide residues in them. No pesticide residues were found in samples from Cheongju, whereas, in case of samples collected from Jeonju, 3 pesticides including chlorothalonil were detected from 5 samples such as eggplant from wholesale market and 3 pesticides including azoxystrobin were found in tomato and grape from traditional market. Pesticide residues were detected from 10.9% of the total samples and detection levels were less than their maximum residue levels. Their estimated daily intakes ranged from 0.00102 to 0.03616% of their acceptable daily intakes, representing residue levels of the pesticides detected were evaluated to be safe.

• Journal of Food Hygiene and Safety
• /
• v.7 no.2
• /
• pp.121-132
• /
• 1992

Pesticides are regarded as one of indispensable materials used in agriculture to protect pests and to keep the agricultural productions steadily. However, food contamination arisen from their application has brought about public concerns for safety suspicion to human health. A brief presentation is given in this paper on what has been conducted against pesticide residues to evaluate and ensure the safety of agro-porducts. The commonest countermeasures to keep safety would be tile establishment of MRls and safe-use guidelines of pesticides according to good agricultural practices. Korean MRls have been established on 38 chemicals with 56 commodities and in the case of safe-use guidelines 344 formulation items have been done by the government On the other hand, no satisfactory information is still available to evalute the actual residue levels in domestic agro-products, but a cautious proposal could be suggested through the fragmentary monitoring data of pesticide residues, so that the current residue levels would be far from potent hazard enough to cause chronic impact on human. The most important thing is to have the farmers keep safe use guidelines at pesticide application for the production of safe agricultural commodities.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
• /
• 1992.07a
• /
• pp.21-32
• /
• 1992

Pesticides are regarded as one of indispensable materials used in agriculture to protect pests and to keep the agriculture productions steadily. However, food contamination arisen from their application has brought about public concerns for safety suspicion to human health. A brief presentation is given in this paper on what has been conducted against pesticide residues to evaluate and ensure the safety of agro-products. The commonest countermeasures to keep safety would be the establishment of MRLs and safe-use guidelines of pesticides according to good agricultural practices. Korean MRLs have bun established on 38 chemicals with 56 commodities and in the case of safe-use guidelines 344 formulation items have been done by the government. On the other hand, no satisfactory information is still available to evalute the actual residue levels in domestic agro-products, but a cautious proposal could be suggested through the fragmentary monitoring data of pesticide residues, so that the current residue levels would be far from potent hazard enough to cause chronic impact on human. The most important thing is to have the farmers keep safe use guidelines at pesticide application for the production of safe agriculture commodities.

• The Korean Journal of Pesticide Science
• /
• v.20 no.1
• /
• pp.23-29
• /
• 2016

This study was carried out to survey residual characteristics of pesticide in fresh ginsengs collected from 45 markets at 15 regions in Korea using multiresidue analysis with a GC-MS/MS and an LC-MS/MS. After residue analysis was performed, the pesticides detected from ginsengs were quantitated using their analytical methods validated by recovery tests with a GC-ECD/NPD. As a results of analysis of pesticide residue, cypermethrin, fenitrothion, fludioxonil, thifluzamide, and tolclofos-methyl were detected from 16 samples among 45 samples in total, indicating detection rate was 35.6%. Tolclofos-methyl was found to be highest in detection frequency in ginseng. Fenitrothion that has not established maximum residue limit and pre-harvest interval for ginseng was detected. The amounts of all pesticides detected were less than their MRLs. Ratios of estimated daily intakes to acceptable daily intakes of the detected pesticides in ginseng were found to be from 0.03 to 16.67%.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.6
• /
• pp.2597-2606
• /
• 2014

Background: There is a scarcity of information about the proportion of the adult Saudi population that meet the recommended guidelines of physical activity (PA) to reduce cancer risk. Moreover, their awareness about the role of PA in cancer prevention is unclear. Objectives: This cross-sectional study aimed at estimating the proportion of adult Saudis meeting the PA guidelines, specifically those recommended by American Cancer Society (ACS) for cancer prevention, and to assess the public awareness about the role of PA in cancer prevention. Materials and Methods: Using a multistage sampling method, 2,127 adult Saudis of both genders were recruited from 6 urban and 4 rural primary health care centers in Al Hassa, Saudi Arabia. Participants were personally interviewed to gather information about their sociodemographic characteristics, searching activity about PA and cancer, and the time spent in leisure time PA (moderate and vigorous)/week using the Global Physical Activity Questionnaire with show cards. Finally, items about the role of PA in cancer risk reduction were inquired. Results: Of the included participants, 11.6% met the recommendations for cancer prevention (${\geq}45$ minutes of moderate-vigorous PA activity/${\geq}5$ days/week or 225 minutes/week). Multivariate regression showed that being male (AOR=1.49, CI=1.09-2.06), <20 years of age (AOR=3.11, CI=2.03-4.76), and unemployed (AOR=2.22, CI=1.57-3.18) were significant predictors for meeting PA recommendations for cancer prevention. Only 11.4% of the sample indicated correctly the frequency and duration of PA required for an average adult to be physically active and while >70% of them indicated the role of PA in prevention of hypertension, coronary heart disease and lowering elevated blood cholesterol, only 18.6% and 21.7% correctly mentioned the role of PA in reducing colon and breast cancer risk, respectively. Poor knowledge was found among those with less than college education and aged ${\geq}50$ years. The level of knowledge was significantly positively correlated with total leisure time PA of the participants. Conclusions: A minority of adult Saudis in Al Hassa was aware about the role of PA in cancer prevention and engaged in sufficient LTPA for cancer risk reduction benefits, highlighting the need for public health actions to include policies and programs that address factors deterring their participation in LTPA and increasing their awareness with remedies to manage the prevalent misconceptions.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.21 no.3
• /
• pp.153-160
• /
• 2010

Objectives: The purpose of this study was to evaluate the prenatal, perinatal, and infancy history of children with autism spectrum disorder (ASD) as compared to unaffected siblings (SIB) and typically developing children (TC). Methods: Subjects with ASD, their SIB, and TC were recruited. All subjects were assessed using both the Korean version of Autism Diagnostic Interview-Revised (K-ADI-R) and the Korean version of Autism Diagnostic Observation Schedule (K-ADOS) and were subsequently identified as affected or unaffected. Prenatal, perinatal, and infancy history was obtained from the primary caregivers and each facet was compared in those with ASD, the SIB, and the TC groups using SPSS ver. 17.0 (p<.05). Results: 70 individuals with ASD (63 males, 87.94${\pm}$37.8months), 53 SIB (27 males, 85.4087.94${\pm}$48.06 months), and 32 TC (19 males, 104.1987.94${\pm}$23.409 months) were analyzed. The ASD group showed significantly higher rates of insufficient vaccination as they aged age ($x^2$=15.54, p=.000). Among the scheduled vaccinations, the DPT vaccination ($x^2$=10.08, p=.006) was insufficient in ASD groups. The ASD group also showed higher rates of sleep disturbances from infancy. Differences in maternal/paternal age at conception, gestational age, and growth parameters at birth were not significantly difference among the three groups. Conclusion: These results do not support the previous controversies regarding the relationship between prenatal/perinatal complications and ASD. However, these results indicate that perinatal and prenatal factors may contribute to the development of ASD.

• Korean journal of applied entomology
• /
• v.17 no.2 s.35
• /
• pp.115-123
• /
• 1978

Present status on the pesticides production, supply, manufacture and pests control in Korea are summarized. The data in the past several years (1971-76) are analyzed to find out the problems and solutions for the further development of plant protection and pesticide industry in Korea. Since the acreages of crop plantation and the quantities of pesticides uses are already near to the stage of plateau, pesticide formulation with imported technical grade should be modified by local synthesis with imported quality. The government pesticides management act and regulations must be modernized urgently in connection with the synthesis. formulation, tests, registration, quality control. price and supply system as well as the safety use of pesticides. Recommendation concerning acceptable daily intakes(ADI) and residue limits must be established for the strengthning pesticide safety use and plant protection activities as soon as possible. The use of fungicide-insectide mixture in dust formulation must be authorized and practiced immediately for the labor saving and one-hit cooperative mass control of rice disease and insect pests, especially. At present, serious considerations on pesticide safety use and integrated pest control are strongly urged to help the farmers, to save the industries and to keep the nature as it is required.

• Journal of The Korean Association For Science Education
• /
• v.35 no.4
• /
• pp.691-707
• /
• 2015

This study aims to develop biology teachers' education program based on argumentation activity about core concepts of evolution and to analyze the characteristics of core concepts of evolution learned during the program. The eight core concepts of evolution in this study were variation, heritability of variation, competition, natural selection, adaptation, differential reproductive rate of individuals, changes in genetic pool within a population, and macroevolution. The performances of teachers participating in the program were compared before and after argumentation activities; consisting of seven sessions on the eight core concepts of evolution. The process of the program was specially designed by learning cycle model for teacher education, consisting of seven phases: identification of the task, production of a tentative argument, small group's written argument, share arguments with the other groups, reflective discussion, final written argument, and organization by an instructor. Participants in the study were two pre-service biology teachers and four in-service biology teachers. The results suggest that biology teachers reduced the teleological explanation for biological evolution and improve its adequacy after the intervention. Teachers lacked the opportunity to discuss variation, heritability of variation, competition, and macroevolution because science textbooks lack information on the concepts of biological evolution. The results of this study suggest that because the argumentation program developed for teachers helps to improve understanding the concepts of evolution and to reduce inadequate conceptions in biology, teacher education programs using argumentation activity and eight core concepts of evolution will play a role for efficient evolution education for biology teachers.

• The Korean Journal of Pesticide Science
• /
• v.13 no.2
• /
• pp.79-86
• /
• 2009

In order to elucidate the residual characteristics of the insecticides, bifenthrin and imidacloprid, the pesticides were sprayed onto the squash and their residues were analyzed with GC-ECD and HPLC. Detection limits of the pesticides were $0.005\;mg;kg^{-1}$ and recoveries of bifenthrin and imidacloprid in squash were from 100.87 to 104.31 and from 79.71 to 92.54%, respectively. Half-lives of bifenthrin and imidacloprid in squash were from 1.8 to 2.9 and from 1.5 to 2.5 days, respectively. Initial concentration of bifenthrin and imidacloprid sprayed at the recommended rate and double rate of recommendation were less than their MRLs. And also, residueal concentrations of the pesticides were rapidly decreased in squash with time. At harvest, estimated daily intakes (EDIs) of the pesticides were less than 0.6% of their acceptable daily intakes (ADIs).