• Restorative Dentistry and Endodontics
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• v.10 no.1
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• pp.31-42
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• 1984

The toxic effect of adhesive resins on the dog's pulp tissue was studied with 70 teeth from 5 dogs. The experimental materials were Clearfil, a mixture of Clearfil with calcium hydroxide powder, Panavia-EX, and a mixture of Panavia-EX with calcium hydroxide powder. As a control group, calcium hydroxide powder was used. Each material was placed on the pulpotomized tissue surface. After 3 days, 1, 2,4, and 6 weeks, the teeth and apical tissue were processed routinly and stained with hematoxylin and eosin. Pathological tissue changes due to the toxicity of adhesive resins were observed by light microscope, and the pH of Panavia-EX and the Bonding agent of Clearfil were measured. Following were the results; 1. In the group of calcium hydroxide powder, slight inflammatory change was observed in the pulpotomized surface and adjacent pulp tissue on 3 day. 1 week case showed incomplete dentin bridge. The remaining pulp tissue was normalized according to the days elapsed. 2. In the group of Clearfil, early inflammatory change revealed in the superificial portion of the remaining pulp tissue on 3 day. The inflammation spreaded over the total pulp tissue and partial necrosis was observed in 1 week and 2 week cases. Total necrosis of pulp tissue and moderate inflammatory change at the apical tissue was noticed in 4 week and 6 week cases. 3. In the group of Panavia-EX, moderate inflammatory change appeared in the superficial pulp tissue on 3 day, and severe inflammatory change over all pulp tissue found in 1 week case. Pulp necrosis was obvious in 2 week case. 4 week and 6 week cases were totally necrotized up to the periapical tissue. 4. In the groups of mixtures with calcium hydroxide powder, the pulp tissue destruction was retarded, compared with the groups of Clearfil and Panavia-EX. 5. Panavia-EX was more destructive than Clearfil. 6. The acidity of freshly mixed Bonding agent of Cleafil was pH 4.0, and that of Panavia-EX was pH 2.0.

• Journal of Labour Economics
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• v.37 no.2
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• pp.49-78
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• 2014

This paper examines the impacts of introducing Five-day school week in South Korean on adolescents' time use. Exploiting the exogenous variation in the adolescents' time at school on Saturday, I estimate the causal effect of change of adolescents' discretion time on their time use. The main findings are as follows. The introduction of the five day school week increased the adolescents' discretion time and their time spent on sleeping, passive leisure(mainly watching television). A one-minute decrease in the adolescents' time at school increase their sleeping time by 0.46 minute and passive leisure time by 0.26 minute.

• Toxicological Research
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• v.19 no.3
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• pp.173-180
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• 2003

The present study was conducted to investigate the single and 2-week repeated dose toxicity of red ginseng acidic polysaccharide (RGAP) in Sprague-Dawley rats. The test article was administered orally to rats at dose levels of 0, and 2000 mg/kg/day for single dose toxicity study and at dose levels of 0, 250, 500, and 1000 mg/kg/day for repeated dose toxicity study. In both studies, there were no treatment-related effects on mortality, clinical signs, food and water consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, necropsy findings and organ weights of all animals treated RGAP. Based on these results, it was concluded that the 2-week repeated oral dose of RGAP may have no toxic effect in rats at a dose level of 1000 mg/kg/day. In the condition of this study, the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg/day for both sexes.

• Korean Journal of Biological Psychiatry
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• v.5 no.1
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• pp.114-121
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• 1998

Bethanechol, a cholinergic agonist, has been recommended for the management of peripheral anticholinergic side effects during the treatment of antipsychotic medications. But there have been few studies which have evaluated the drug interactions of antipsychotics and bethanechol, even the treatment effects of bethanechol on anticholinergic side effects. So the authors have evaluated whether psychopathology and plasma haloperidol and reduced haloperidol concentrations are significantly changed or not when bethanechol was administrated with maintained doses of haloperidol and other coadministrated drugs(such a benztropine). Also we have evaluated the abating effects of bethanechol on anticholinergic side effects during the treatment with haloperidol. Fifteen schizophrenics with higher than 5 of total score of anticholinergic side effects of 'Rating scale for side effect' were assigned to two groups, and bethanechol 30mg/day and 60mg/day were applied on each group for 4 weeks. The daily haloperidol dosages were fixed before 2 weeks of study. We assessed anticholinergic side effects by 'Rating scale for side effect' and psychopathology by BPRS, and plasma haloperidol and reduced haloperidol concentrations by HPLC at baseline, 2nd week and 4th week. The results were as followed, 1) there was no significant change of plasma haloperidol and reduced haloperidol concentration, 2) at baseline, the dosage of haloperidol showed significant correlation with the total score of anticholinergic side effect, but not at 2nd week and 4th week, 3) in 60mg/day group, dry mouth and the total score of anticholinergic side effects were significantly improved, but not in 30mg/day group, 4) there was no significant change of BPRS except withdrawal at 2nd week. These results suggest that coadministration of bethanechol influenced neither on psychopathology nor on plasma haloperidol and reduced haloperidol concentrations and that improved dry mouth and total score of anticholinergic side effects at 60mg/day.

• Toxicological Research
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• v.31 no.1
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• pp.77-88
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• 2015

Lithospermum erythrorhizon has long been used in traditional Asian medicine for the treatment of diseases, including skin cancer. The oral toxicity of a hexane extract of Lithospermum erythrorhizon root (LEH) was investigated in Beagle dogs by using single escalating doses, two-week dose range-finding, and 4-week oral repeat dosing. In the single dose-escalating oral toxicity study, no animal died, showed adverse clinical signs, or changes in body weight gain at LEH doses of up to 2,000 mg/kg. In a 2 week dose range-finding study, no treatment-related adverse effects were detected by urinalysis, hematology, blood biochemistry, organ weights, or gross and histopathological examinations at doses of up to 500 mg LEH/kg/day. In the 4 week repeat-dose toxicity study, a weight loss or decreased weight gain was observed at 300 mg/kg/day. Although levels of serum triglyceride and total bilirubin were increased in a dose dependent manner, there were no related morphological changes. Based on these findings, the sub-acute no observable adverse effect level for 4-week oral administration of LEH in Beagles was 100 mg/kg/day.

• Biomolecules & Therapeutics
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• v.2 no.3
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• pp.260-269
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• 1994

This study was performed to determine the toxic effect of DA-3030(granulocyte-colony stimulating factor, G-CSF) in beagle dogs. DA-3030(G-CSF) was injected intravenously at doses of 115 $\mu\textrm{g}$/kg/day, 11.5 $\mu\textrm{g}$/kg/day and 1.15 $\mu\textrm{g}$/kg/day seven days per week for 28 days. After completion of the treatments, the dog were necropsied. The number of dead animal was zero in all groups. No specific clinical sign was found, either. In hematological results, WBC was significantly increased dose-dependently in treated groups. In histopathological findings, megakaryocyte and rubricyte were found in the liver and spleen at the dose of 115 $\mu\textrm{g}$/kg/day. Therefore, we could find the extramedullary hematopoiesis was increased. Megaka yocyte and rubricyte were increased in bone marrow, too. In conclusion, those signs were estimated the pharmacological effect of DA-3030(G-CSF). According to the results, non toxic dose of DA-3030(G-CSF) was higher than 115 $\mu\textrm{g}$/kg/day.

• Safety and Health at Work
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• v.6 no.3
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• pp.240-248
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• 2015

Background: Recovery from fatigue is important in maintaining night workers' health. This study compared the course of self-reported recovery after 2-week 12-hour schedules consisting of either night shifts or swing shifts (i.e., 7 night shifts followed by 7 day shifts) to such schedules consisting of only day work. Methods: Sixty-one male offshore employees-20 night workers, 16 swing shift workers, and 25 day workers-rated six questions on fatigue (sleep quality, feeling rested, physical and mental fatigue, and energy levels; scale 1-11) for 14 days after an offshore tour. After the two night-work schedules, differences on the $1^{st}$ day (main effects) and differences during the follow-up (interaction effects) were compared to day work with generalized estimating equations analysis. Results: After adjustment for confounders, significant main effects were found for sleep quality for night workers (1.41, 95% confidence interval 1.05-1.89) and swing shift workers (1.42, 95% confidence interval 1.03-1.94) when compared to day workers; their interaction terms were not statistically significant. For the remaining fatigue outcomes, no statistically significant main or interaction effects were found. Conclusion: After 2-week 12-hour night and swing shifts, only the course for sleep quality differed from that of day work. Sleep quality was poorer for night and swing shift workers on the $1^{st}$ day off and remained poorer for the 14-day follow-up. This showed that while working at night had no effect on feeling rested, tiredness, and energy levels, it had a relatively long-lasting effect on sleep quality.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.245.1-245.1
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• 2003

DA-8159 is a new PDEV (Phosphodiesterase V) inhibitor, synthesized by Dong-A Pharm., as an oral agent to treat male erectile dysfunction. To make a selection of the dosage of oral administration in carcinogenic studies, we studied preliminarily the pharmacokinetics of DA-8159 after single (at the 1$\^$st/ day) and 1-week (at the 7$\^$th/ day) oral administrations of the drug at doses of 15, 50 and 150 mg/kg/day, to male ICR mice. In 15mg/kg single and 1-week repeated oral administration groups, the concentrations of DA-8159 and DA-8164(the main metabolite of DA-8159) were below the limit of quantitation(LOQ:50ng/ml). (omitted)

• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.226-235
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• 1993

DA-125, a new anthracycline antitumor antibiotic, was administered to Sprague-Dawley rats intravenously for 4 weeks to investigate the repeated dose toxicity Focal alopecia was noted in three female rats receiving 1.0mg/kg/day. In rats receiving 1.0 mg/kg/day, weight gain decreased in both sexes after first or second week. Hematological examination revealed lower counts of total leukocyte and increased numbers of platelet after second week. At terminal necropsy, atrophy of thymus and spleen was observed. Lymphocytic depletion of thymus and atrophy of white pulp in spleen were observed microscopically. A decrease in the number of hematopoietic cells in the bone marrow and degeneration of germinal epithelia in testes were also observed. These treatment-related effects were mainly confined to rats receiving 1.0 mg/kg/day. And toxic effects with microscopic changes were not observed in rats receiving 0.2 mg/kg/day or 0.04 mg/kg/day.

• Proceedings of KHEA Conference
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• 2002.10a
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• pp.3-10
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• 2002