• Toxicological Research
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• 제20권3호
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• pp.281-292
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• 2004

The purpose of this study was to assess the single and 5 week oral dose toxicity of calcitriol and alendronate combination (1 : 10,000) treatment for osteoporosis or Paget's disease in male and female rats. In single dose oral toxicity study, the values of $LD_{50}$ of calcitriol and alendronate mixture were 750.075 mg/kg in male rats and 775.0775 mg/kg in female rats, respectively. Body weight and food consumption were continuously increased after adminstration of calcitriol and alendronate mixtures, and there was no significant changes in body weight and food consumption in all groups. In five-week oral toxicity study of calcitriol and alendronate mixture at a dose of 0.2 $\mu\textrm{g}$ + 2 mg, 1 $\mu\textrm{g}$ + 10 mg, 5 $\mu\textrm{g}$ + 50 mg and 25 $\mu\textrm{g}$ + 250 mg, respectively, there was no mortality, abnormal behavior and appearance in all groups throughout the administration period (5 weeks) and recovery period (2 weeks). Dose-dependent changes in parameters of urinalysis and hematological analysis were not observed in male and female rats treated with calcitriol and alendronate mixtures. All the values of the parameters appeared to be in the normal range. These data indicate that both calcitriol and alendronate are drugs having low toxicity in rats. NOAEL of calcitriol and alendronate mixtures were 50.005 mg/kg in 5-week oral toxicity.

• Toxicological Research
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• 제26권1호
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• pp.29-35
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• 2010

The present study was conducted to investigate the antimutagenic potential of the methanolic extract from the leaves of sweet potato (Ipomea batatas, IB) with the SOS chromotest (umu test) and Salmonella typhimurium TA 98 and TA 100. The anticarcinogenic effects were also studied by calculation of the $IC_{50}$ on human cancer cell lines and investigating the function of gap junction in rat liver epithelial cells. The IB extract inhibited dose-dependently the ${\beta}$-galactosidase activity induced spontaneously at concentration of more than 200 mg/ml in S. typhimurium TA 1535/pSK 1002, and decreased significantly (p < 0.01) the ${\beta}$-galactosidase activities induced by mutagen 6-chloro-9-[3-(2-chloroethylamino)proylamino]-2-methoxyacridine dihydrochloride (ICR) at dose of more than 0.4 mg/0.1 ml. The IB extract showed no effect on the spontaneous reversions of S. typhimurium TA 98 and 100 but benzo(${\alpha}$)pyrene (BaP)-stimulated reversions were decreased dose-dependently (p < 0.01) at the concentration of more than 100 mg/ml. The $IC_{50}$ value of stomach cancer cells was lower than that of normal rat liver epithelial cells, but the values of colon and uterine cancer cell lines were similar to those of normal rat liver epithelial cells. The transfer of dye through gap junctions was not affected by treatment of the IB extracts at any concentration during treatment periods. The simultaneously treatment of IB extract and 12-O-tetradecanoylphorbol-13-acetate (TPA) effectively prevented the inhibition of dye transfer induced by TPA 1 hour after treatment at all exposed concentrations. The number of gap junctions was significantly (p < 0.01) increased by the treatment with IB extract at concentrations of more than 40 ${\mu}g$/ml. The inhibition of the expression of gap junction proteins by TPA (0.01 ${\mu}g$/ml) was recovered dose dependently by the simultaneous treatment of IB extracts. Our data suggest that Ipomea batatas has antimutagenic and anticarcionogenic activity in vitro.

• Toxicological Research
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• 제30권2호
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• pp.83-90
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• 2014

An increasing number of recent studies have focused on the impact of particulate matter on human health. As a model for atmospheric particulate inhalation, we investigated the effects of inhaled carbon black nanoparticles (CBNP) on mice with bleomycin-induced pulmonary fibrosis. The CNBPs were generated by a novel aerosolization process, and the mice were exposed to the aerosol for 4 hours. We found that CBNP inhalation exacerbated lung inflammation, as evidenced by histopathology analysis and by the expression levels of interleukin-6 protein, fibronectin, and interferon-${\gamma}$ mRNAs in lung tissues. Notably, fibronectin mRNA expression showed a statistically significant increase in expression after CBNP exposure. These data suggest that the concentration of CBNPs delivered (calculated to be $12.5{\mu}g/m^3$) can aggravate lung inflammation in mice. Our results also suggest that the inhalation of ultrafine particles like PM 2.5 is an impactful environmental risk factor for humans, particularly in susceptible populations with predisposing lung conditions.

• Toxicological Research
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• 제32권4호
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• pp.337-343
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• 2016

We determined the toxicity of mixtures of ethyl acetate (EA), isopropyl alcohol (IPA), methyl ethyl ketone (MEK), toluene (TOL) and xylene (XYL) with half-maximal effective concentration ($EC_{50}$) values obtained using human hepatocytes cells. According to these data, quantitative property-activity relationships (QPAR) models were successfully proposed to predict the toxicity of mixtures by multiple linear regressions (MLR). The leave-one-out cross validation method was used to find the best subsets of descriptors in the learning methods. Significant differences in physico-chemical properties such as boiling point (BP), specific gravity (SG), Reid vapor pressure (rVP) and flash point (FP) were observed between the single substances and the mixtures. The $EC_{50}$ of the mixture of EA and IPA was significantly lower than that of contained TOL and XYL. The mixture toxicity was related to the mixing ratio of MEK, TOL and XYL (MLR equation $EC_{50}=3.3081-2.5018{\times}TOL-3.2595{\times}XYL-12.6596{\times}MEK{\times}XYL$), as well as to BP, SG, VP and FP (MLR equation $EC_{50}=1.3424+6.2250{\times}FP-7.1198{\times}SG{\times}FP-0.03013{\times}rVP{\times}FP$). These results suggest that QPAR-based models could accurately predict the toxicity of polar and nonpolar mixtures used in rotogravure printing industries.

• Toxicological Research
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• 제32권4호
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• pp.289-300
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• 2016

Non-genotoxic carcinogens are substances that induce tumorigenesis by non-mutagenic mechanisms and long term rodent bioassays are required to identify them. Recent studies have shown that transcription profiling can be applied to develop early identifiers for long term phenotypes. In this study, we used rat liver expression profiles from the NTP (National Toxicology Program, Research Triangle Park, USA) DrugMatrix Database to construct a gene classifier that can distinguish between non-genotoxic carcinogens and other chemicals. The model was based on short term exposure assays (3 days) and the training was limited to oxidative stressors, peroxisome proliferators and hormone modulators. Validation of the predictor was performed on independent toxicogenomic data (TG-GATEs, Toxicogenomics Project-Genomics Assisted Toxicity Evaluation System, Osaka, Japan). To build our model we performed Random Forests together with a recursive elimination algorithm (VarSelRF). Gene set enrichment analysis was employed for functional interpretation. A total of 770 microarrays comprising 96 different compounds were analyzed and a predictor of 54 genes was built. Prediction accuracy was 0.85 in the training set, 0.87 in the test set and increased with increasing concentration in the validation set: 0.6 at low dose, 0.7 at medium doses and 0.81 at high doses. Pathway analysis revealed gene prominence of cellular respiration, energy production and lipoprotein metabolism. The biggest target of toxicogenomics is accurately predict the toxicity of unknown drugs. In this analysis, we presented a classifier that can predict non-genotoxic carcinogenicity by using short term exposure assays. In this approach, dose level is critical when evaluating chemicals at early time points.

• Molecular & Cellular Toxicology
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• 제5권1호
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• pp.58-66
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• 2009

The 2-year rodent carcinogenicity test involves long-term, repetitive dosing of animals that is both time consuming and expensive. Alternative approaches have been attempted using specific transgenic or knockout mice or toxicogenomics to predict carcinogenicity without conducting a 2-year rodent test. In addition, toxicogenomic analysis of carcinogen-treated animals could also enhance our understanding of molecular mechanisms and aid in the diagnosis of acute toxicity induced by carcinogens. Therefore, we investigated transcription profiles after administering the carcinogens 4,4-dimethylformamide (DMF) and 4-biphenylamine (ABP). BALB/c male mice were treated once with DMF (650 mg/kg i.p.) or ABP (120 mg/kg p.o.). Standard blood biochemistry and histological changes were observed. Gene expression profiles in the livers of mice treated with either vehicle or the carcinogens were analyzed using the Affymetrix $GeneChip^{(R)}$ assay. In all, 1,474 differentially expressed genes in DMF- or ABP-treated mice were identified as being either up- or down-regulated over 1.5-fold (P< 0.01), and these genes were analyzed using hierarchical clustering and Ingenuity Pathways Analysis. Of these, 107 genes were consistently regulated in both carcinogen-treated groups. Genes associated with cancer were upregulated (Por, S100a10, Tes, Ctcf, Ddx21, Eapp, Nel, and Pa2g4) or downregulated (Cbs and Gch1). Toxicological function analysis also identified genes involved in organ toxicity, including hepatotoxicity. These data may help to identify molecular markers for acute hepatotoxicity induced by carcinogens.

• 대한임상독성학회지
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• 제3권1호
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• pp.33-39
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• 2005

Purpose: Nowadays the Korean society is in the center of time of the social change. Because of dissociation of traditional family, IMF (International Monetary Fund) crisis and economic recession, the mortality rate of suicidal attempts are increasing annually. The majority of suicidal attempts were by poisoning considering the characteristics of korean society. Therefore we studied to find out the characteristics of suicidal poisoning before and after social economic stress, and to suggest the direction for the proper management. Methods: We reviewed medical records of 547 patients of suicide by poisoning who visited the emergency medical centers of St. Mary's hospitals from 1997 to 2004. For the annual trends analysis, we analyzed the demographic and toxicologic data of these patients compared with before and after IMF crisis (1998) and the economic recession ($2003\~2004$). Results: At the time of IMF and the economic recession, the number of suicidal poisoning increased, especially in fifth decade. The refusal rate of toxicological emergency treatment increased. Also the mortality rate and the admission rate to ICU (Intensive Care Unit) increased during the same period. In the result of the comparison analysis, clinical severity and mortality of social problem group were higher. However they couldn't be treated appropriately because of financial problem and the family indifference. Conclusion: At the economic recession period, the severity of suicidal poisoned patients was high. But the refusal rate of toxicologic treatment also increased, so the patients had lost the chance for proper toxicologic treatment. Therefore they would be supported by medical institution and public health.

• 한국산업보건학회지
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• 제16권1호
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• pp.54-67
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• 2006

This study was performed to deduct the extension possibility of the standards establishment for $NO_2$, $O_3$, Asbestos, Radon, total volatile organic compounds (TVOC) excluded in the indoor air part of Industrial Safety Acts in Korea. The air pollutants were sampled for 30 office buildings from August to September, 2005 in the metropolitan area. The airborne concentrations of $NO_2$, $O_3$, Radon and TVOC were 0.0092 ppm, 0.0035 ppm, 0.57 pCi/L and $423{\mu}g/m^3$, respectively. The management plan and reduction methods is required in the aspect of indoor air quality(IAQ) because the emission sources of those also exist in indoor as well as outdoor even though those were not exceeded the standards of the Ministry of Environment in Korea. The standard for TVOC in the new and remodeling office has to be established based on the risk assessment when hazard index exceeded "1" in the worst case scenario. In the state of art, the management of each volatile organic compounds has a difficulty due to not enough data for toxicological reference. Therefore, it is suggested that first of all, the standard for TVOC be established and then expanded to each materials for decision-making of improvement of IAQ in office.

• Toxicological Research
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• 제16권3호
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• pp.211-219
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• 2000

The therapeutic effect of AS2-006A, a derivative of asiaticoside, has been studied and is being developed as a new wound-healing agent. In the present study, the general pharmacological effects on 1) central nervous system, 2) autonomic nervous system, 3) respiratory system, 4) gastrointestinal system. 5) cardiovascular system. and 6) urinary system were assessed in experimental animals and in in vitro models. 1. In vivo animal study: External applications of the 1 % gel ointment of AS2-006A to rats at the doses of 200. 600 or 2000 mg/kg body weight showed no observable pharmacological effects. The effects on the central nervous system were assessed by observation of behavior, hexobarbital-induced sleeping time, pentetrazole-induced convulsion assay, body temperature measurements, and observations on spontaneous activity and catalepsy. The gel ointment exhibited no effects on the cardiovascular system (i.e. blood pressure and heart rate), renal physiology (i.e. urine volume and electrolytes excretion) and gas-trointestinal physiology (i.e. intestinal charcoal propulsion and gastric mucosal irritation). 2. In vitro experiments: The effects of AS2-006A on the physiology of smooth and cardiac muscles were assessed. Muscle contractions were isotonically and isometrically measured in organ chambers using a physiograph. Cumulative additions of AS2-006A (10$^{-9}$ -10$^{-5}$ M) induced no changes in the tension of isolated guinea pig ileum and tracheal muscles. AS2-006A only slightly increased contractility of rat atrial and papillary muscles at 10$^{-2}$ M, which was not statistically different from control. These data showed that the gel ointment of AS2-006A could be externally applied as a wound-healing agent with no potential side effects.

• Toxicological Research
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• 제24권3호
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• pp.201-206
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• 2008

Exposure to formaldehyde(FA) is closely associated with adverse health effects such as irritation, inflammation, and squamous cell carcinomas of the nasal cavities. Owing to its rapid metabolism and elimination, exposure to FA does not always result in an increased concentration in blood or urine of animals and humans. Therefore, the development of biomarkers for FA exposure is necessary for risk assessment. In the present study, the effects of FA were investigated on the expression of genes involved in the MAPK pathway in vitro and results confirmed in rats exposed to FA by inhalation. Treatment of Hs 680.Tr human tracheal epithelial cells with FA induced gene expression for PDGFA, TNFSF11, SHC1, and HRAS. HRAS expression was also increased in tracheas of rats exposed to FA. In addition, FA exposure induced the expression of RASSF4, a member of the Rasassociation domain family of Ras effectors, in rat tracheas. In conclusion, data showed FA-inducible expression of genes involved in the MAPK pathway occurred and increased expression of HRAS and RASSF4 was noted in rat tracheas subchronically exposed to FA by inhalation. These genes may serve as molecular targets of FA toxicity facilitating the understanding of the toxic mechanism.