• 제목/요약/키워드: Mutagen

검색결과 3,108건 처리시간 0.029초

Retinopathy Induced by Zinc Oxide Nanoparticles in Rats Assessed by Micro-computed Tomography and Histopathology

  • Kim, Young Hee;Kwak, Kyung A;Kim, Tae Sung;Seok, Ji Hyeon;Roh, Hang Sik;Lee, Jong-Kwon;Jeong, Jayoung;Meang, Eun Ho;Hong, Jeong-sup;Lee, Yun Seok;Kang, Jin Seok
    • Toxicological Research
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    • 제31권2호
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    • pp.157-163
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    • 2015
  • Nanotechnology has advanced at an extremely rapid pace over the past several years in numerous fields of research. However, the uptake of nanoparticles (NPs) into the body after administration through various routes may pose a risk to human health. In this study, we investigated the potential ocular toxicity of 20-nm, negatively- charged zinc oxide (ZnO) NPs in rats using micro-computed tomography (micro-CT) and histopathological assessment. Animals were divided into four groups as control group, ZnO NPs treatment group (500 mg/kg/day), control recovery group, and ZnO NPs treatment and recovery group. Ocular samples were prepared from animals treated for 90 days (10 males and 10 females, respectively) and from recovery animals (5 males and 5 females, respectively) sacrificed at 14 days after final treatment and were compared to age-matched control animals. Micro-CT analyses represented the deposition and distribution of foreign materials in the eyes of rats treated with ZnO NPs, whereas control animals showed no such findings. X-ray fluorescence spectrometry and energy dispersive spectrometry showed the intraocular foreign materials as zinc in treated rats, whereas control animals showed no zinc signal. Histopathological examination revealed the retinopathy in the eyes of rats treated with ZnO NPs. Neuronal nuclei expression was decreased in neurons of the ganglion cell layer of animals treated with ZnO NPs compared to the control group. Taken together, treatment with 20-nm, negatively-charged ZnO NPs increased retinopathy, associated with local distribution of them in ocular lesions.

A Rapid and Sensitive Detection of Aflatoxin-producing Fungus Using an Optimized Polymerase Chain Reaction (PCR)

  • Bintvihok, Anong;Treebonmuang, Supitchaya;Srisakwattana, Kitiya;Nuanchun, Wisut;Patthanachai, Koranis;Usawang, Sungworn
    • Toxicological Research
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    • 제32권1호
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    • pp.81-87
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    • 2016
  • Aflatoxin B1 (AFB1) is produced by Aspergillus flavus growing in feedstuffs. Early detection of maize contamination by aflatoxigenic fungi is advantageous since aflatoxins exert adverse health effects. In this study, we report the development of an optimized conventional PCR for AFB1 detection and a rapid, sensitive and simple screening Real-time PCR (qPCR) with SYBR Green and two pairs of primers targeting the aflR genes which involved aflatoxin biosynthesis. AFB1 contaminated maize samples were divided into three groups by the toxin concentration. Genomic DNA was extracted from those samples. The target genes for A. flavus were tested by conventional PCR and the PCR products were analyzed by electrophoresis. A conventional PCR was carried out as nested PCR to verify the gene amplicon sizes. PCR-RFLP patterns, obtained with Hinc II and Pvu II enzyme analysis showed the differences to distinguish aflatoxin-producing fungi. However, they are not quantitative and need a separation of the products on gel and their visualization under UV light. On the other hand, qPCR facilitates the monitoring of the reaction as it progresses. It does not require post-PCR handling, which reduces the risk of cross-contamination and handling errors. It results in a much faster throughout. We found that the optimal primer annealing temperature was $65^{\circ}C$. The optimized template and primer concentration were $1.5{\mu}L\;(50ng/{\mu}L)$ and $3{\mu}L\;(10{\mu}M/{\mu}L)$ respectively. SYBR Green qPCR of four genes demonstrated amplification curves and melting peaks for tub1, afIM, afIR, and afID genes are at $88.0^{\circ}C$, $87.5^{\circ}C$, $83.5^{\circ}C$, and $89.5^{\circ}C$ respectively. Consequently, it was found that the four primers had elevated annealing temperatures, nevertheless it is desirable since it enhances the DNA binding specificity of the dye. New qPCR protocol could be employed for the determination of aflatoxin content in feedstuff samples.

Different Regulation of p53 Expression by Cadmium Exposure in Kidney, Liver, Intestine, Vasculature, and Brain Astrocytes

  • Lee, Jin-Yong;Tokumoto, Maki;Hattori, Yuta;Fujiwara, Yasuyuki;Shimada, Akinori;Satoh, Masahiko
    • Toxicological Research
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    • 제32권1호
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    • pp.73-80
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    • 2016
  • Chronic exposure to cadmium (Cd) is known to adversely affect renal function. Our previous studies indicated that Cd induces p53-dependent apoptosis by inhibiting gene expression of the ubiquitin-conjugating enzyme (Ube) 2d family in both human and rat proximal tubular cells. In this study, the effects of Cd on protein expression of p53 and apoptotic signals in the kidney and liver of mice exposed to Cd for 12 months were examined, as well as the effects of Cd on p53 protein levels and gene expression of the Ube2d family in various cell lines. Results showed that in the kidney of mice exposed to 300 ppm Cd for 12 months, there was overaccumulation of p53 proteins in addition to the induction of apoptosis, which was triggered specifically in the proximal tubules. Interestingly, the site of apoptosis was the same as that of p53 accumulation in the proximal tubules. In the liver of mice chronically exposed to Cd, gene expression of the Ube2d family tended to be slightly decreased, together with slight apoptosis without the accumulation of p53 protein. In rat small intestine epithelial (IEC-6) cells, Cd decreased not only the p53 protein level but also gene expression of Ube2d1, Ube2d2 and Ube2d4. In human brain microvascular endothelial cells (HBMECs), Cd did not suppress gene expression of the Ube2d family, but increased the p53 protein level. In human brain astrocytes (HBASTs), Cd only increased gene expression of UBE2D3. These results suggest that Cd-induced apoptosis through p53 protein is associated with renal toxicity but not hepatic toxicity, and the modification of p53 protein by Cd may vary depending on cell type.

Associations of Low Environmental Exposure to Multiple Metals with Renal Tubular Impairment in Korean Adults

  • Lim, Hyungryul;Lim, Ji-ae;Choi, Jong Hyuk;Kwon, Ho-jang;Ha, Mina;Kim, Heon;Park, Jung-duck
    • Toxicological Research
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    • 제32권1호
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    • pp.57-64
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    • 2016
  • Recently several studies reported that the renal toxicity of lead (Pb) and cadmium (Cd) may exist in even a low level exposure. In terms of the deterioration of tubular function, it affects the loss of divalent metals and leads to other complications, so renal tubular effect of heavy metals should be well managed. Considering the exposure to heavy metals in reality, it is hard to find the case that human is exposed to only one heavy metal. We designed a cross-sectional study using Korean Research Project on the Integrated Exposure Assessment (KRIEFS) data to investigate the renal effects of multiple metal exposure in general population. We used blood Pb and urinary Cd as exposure measures, and urinary N-acetyl-${\beta}$-D-glucosaminidase (NAG) and ${\beta}_2$-microglobulin (${\beta}_2$-MG) as renal tubular impairment outcome. We conducted linear regression to identify the association between each heavy metal and urinary NAG and ${\beta}_2$-MG. And then, we conducted linear regression including the interaction term. Of 1953 adults in KRIEFS (2010~2011), the geometric mean of blood Pb and urinary Cd concentration was $2.21{\mu}g/dL$ (geometric $SD=1.49{\mu}g/dL$) and $1.08{\mu}g/g\;cr$ (geometric $SD=1.98{\mu}g/g\;cr$), respectively. In urinary Cd, the strength of the association was also high after adjusting (urinary NAG: ${\beta}=0.44$, p < 0.001; urinary ${\beta}_2$-MG: ${\beta}=0.13$, p = 0.002). Finally, we identified the positive interactions for the two renal biomarkers. The interaction effect of the two heavy metals of ${\beta}_2$-MG was greater than that of NAG. It is very important in public health perspective if the low level exposure to multiple heavy metals has an interaction effect on kidney. More epidemiological studies for the interaction and toxicological studies on the mechanism are needed.

A Rapid Method for Estimating the Levels of Urinary Thiobarbituric Acid Reactive Substances for Environmental Epidemiologic Survey

  • Kil, Han-Na;Eom, Sang-Yong;Park, Jung-Duck;Kawamoto, Toshihiro;Kim, Yong-Dae;Kim, Heon
    • Toxicological Research
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    • 제30권1호
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    • pp.7-11
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    • 2014
  • Malondialdehyde (MDA), used as an oxidative stress marker, is commonly assayed by measuring the thiobarbituric acid reactive substances (TBARS) using HPLC, as an indicator of the MDA concentration. Since the HPLC method, though highly specific, is time-consuming and expensive, usually it is not suitable for the rapid test in large-scale environmental epidemiologic surveys. The purpose of this study is to develop a simple and rapid method for estimating TBARS levels by using a multiple regression equation that includes TBARS levels measured with a microplate reader as an independent variable. Twelve hour urine samples were obtained from 715 subjects. The concentration of TBARS was measured at three different wavelengths (fluorescence: ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm; ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm; and absorbance: 532 nm) using microplate reader as well as HPLC. 500 samples were used to develop a regression equation, and the remaining 215 samples were used to evaluate the validity of the regression analysis. The induced multiple regression equation is as follows: TBARS level (${\mu}M$) = -0.282 + 1.830 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm, ${\mu}M$) -0.685 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm, ${\mu}M$) + 0.035 ${\times}$ (TBARS level measured with a microplate reader at the absorbance wavelength 532 nm, ${\mu}M$). The estimated TBARS levels showed a better correlation with, and are closer to, the corresponding TBARS levels measured by HPLC compared to the values obtained by the microplate method. The TBARS estimation method reported here is simple and rapid, and that is generally in concordance with HPLC measurements. This method might be a useful tool for monitoring of urinary TBARS level in environmental epidemiologic surveys with large sample sizes.

Milk Transfer and Toxicokinetics of Valproic Acid in Lactating Cynomolgus Monkeys

  • Lee, Jong-Hwa;Yu, Wook-Joon;Jeong, Eun Ju;Chung, Moon-Koo
    • Toxicological Research
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    • 제29권1호
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    • pp.53-60
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    • 2013
  • Studies on milk transfer of drugs in non-human primates (NHPs) are among the crucial components in the assessment of peri- and postnatal toxicity because of the similarity between NHPs and humans. To evaluate the milk transfer of valproic acid (VPA) in NHPs, the toxicokinetics of VPA, an antiepileptic drug, were studied in pregnant cynomolgus monkeys. VPA was administered once daily to pregnant cynomolgus monkeys at doses of 0, 30, 90, and 270 mg/kg by oral gavage from Day 100 of gestation (GD 100) to Day 31 of lactation (LD 31). Concentrations of VPA and its metabolite, 4-ene-VPA, in the maternal plasma on GD 100, GD 140, and LD 30, and concentrations of VPA and 4-ene-VPA in the offspring plasma and milk on LDs 30 and 31, respectively, were quantified using liquid chromatography tandem mass spectrometry (LC/MS/MS). After administration of a single oral dose of VPA to pregnant monkeys on GD 100, the concentrations of VPA and 4-ene-VPA were generally quantifiable in the plasma of all treatment groups up to 24 hr after administration, which showed that VPA was absorbed and that the monkeys were systemically exposed to VPA and 4-ene-VPA. After administration of multiple doses of VPA to the monkeys, VPA was detected in the pup's plasma and in milk taken on LD 30 and LD 31, respectively, which showed that VPA was transferred via milk, and the pup was exposed to VPA. Further, the concentration of VPA in the milk increased with an increase in the dose. Extremely low concentrations of 4-ene VPA were detected in the milk and in the pup plasma. In conclusion, pregnant monkeys were exposed to VPA and 4-ene-VPA after oral administration of VPA at doses of 30, 90, and 270 mg/kg/day from GD 100 to LD 31. VPA was transferred via milk, and the VPA exposure to the pup increased with an increase in the dose of VPA. The metabolite, 4-ene VPA, was present in extremely low concentrations (< 0.5 ${\mu}g/ml$) in the milk and in the pup plasma. In this study, we established methods to confirm milk transfer in NHPs, such as mating and diagnosis of pregnancy by examining gestational sac with ultrasonography, collection of milk and pup plasma and determination of toxicokinetics, using cynomolgus monkeys.

Evaluation of Oxidative DNA Damage Using an Alkaline Single Cell Gel Electrophoresis (SCGE) Comet Assay, and the Protective Effects of N-Acetylcysteine Amide on Zearalenone-induced Cytotoxicity in Chang Liver Cells

  • Kang, Changgeun;Lee, Hyungkyoung;Yoo, Yong-San;Hah, Do-Yun;Kim, Chung Hui;Kim, Euikyung;Kim, Jong Shu
    • Toxicological Research
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    • 제29권1호
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    • pp.43-52
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    • 2013
  • Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium that are found in cereals and agricultural products. ZEN has been implicated in mycotoxicosis in farm animals and in humans. The toxic effects of ZEN are well known, but the ability of an alkaline Comet assay to assess ZEN-induced oxidative DNA damage in Chang liver cells has not been established. The first aim of this study was to evaluate the Comet assay for the determination of cytotoxicity and extent of DNA damage induced by ZEN toxin, and the second aim was to investigate the ability of N-acetylcysteine amide (NACA) to protect cells from ZEN-induced toxicity. In the Comet assay, DNA damage was assessed by quantifying the tail extent moment (TEM; arbitrary unit) and tail length (TL; arbitrary unit), which are used as indicators of DNA strand breaks in SCGE. The cytotoxic effects of ZEN in Chang liver cells were mediated by inhibition of cell proliferation and induction of oxidative DNA damage. Increasing the concentration of ZEN increased the extent of DNA damage. The extent of DNA migration, and percentage of cells with tails were significantly increased in a concentration-dependent manner following treatment with ZEN toxin (p < 0.05). Treatment with a low concentration of ZEN toxin (25 ${\mu}M$) induced a relatively low level of DNA damage, compared to treatment of cells with a high concentration of ZEN toxin (250 ${\mu}M$). Oxidative DNA damage appeared to be a key determinant of ZEN-induced toxicity in Chang liver cells. Significant reductions in cytolethality and oxidative DNA damage were observed when cells were pretreated with NACA prior to exposure to any concentration of ZEN. Our data suggest that ZEN induces DNA damage in Chang liver cells, and that the antioxidant activity of NACA may contribute to the reduction of ZEN-induced DNA damage and cytotoxicity via elimination of oxidative stress.

Biodistribution of 99mTc Labeled Integrin Antagonist

  • Jang, Beom-Su;Park, Seung-Hee;Shin, In Soo;Maeng, Jin-Soo;Paik, Chang H.
    • Toxicological Research
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    • 제29권1호
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    • pp.21-25
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    • 2013
  • The selective targeting of an integrin ${\alpha}_v{\beta}_3$ receptor using radioligands may enable the assessment of angiogenesis and integrin ${\alpha}_v{\beta}_3$ receptor status in tumors. The aim of this research was to label a peptidomimetic integrin ${\alpha}_v{\beta}_3$ antagonist (PIA) with $^{99m}Tc(CO)_3$ and to test its receptor targeting properties in nude mice bearing receptor-positive tumors. PIA was reacted with tris-succinimidyl aminotriacetate (TSAT) (20 mM) as a PIA per TSAT. The product, PIA-aminodiacetic acid (ADA), was radiolabeled with $[^{99m}Tc(CO)_3(H_2O)_3]^{+1}$, and purified sequentially on a Sep-Pak C-18 cartridge followed by a Sep-Pak QMA anion exchange cartridge. Using gradient C-18 reverse-phase HPLC, the radiochemical purity of $^{99m}Tc(CO)_3$-ADA-PIA (retention time, 10.5 min) was confirmed to be > 95%. Biodistribution analysis was performed in nude mice (n = 5 per time point) bearing receptor-positive M21 human melanoma xenografts. The mice were administered $^{99m}Tc(CO)_3$-ADA-PIA intravenously. The animals were euthanized at 0.33, 1, and 2 hr after injection for the biodistribution study. A separate group of mice were also co-injected with 200 ${\mu}g$ of PIA and euthanized at 1 hr to quantify tumor uptake. $^{99m}Tc(CO)_3$-ADA-PIA was stable in phosphate buffer for 21 hr, but at 3 and 6 hr, 7.9 and 11.5% of the radioactivity was lost as histidine, respectively. In tumor bearing mice, $^{99m}Tc(CO)_3$-ADA-PIA accumulated rapidly in a receptor-positive tumor with a peak uptake at 20 min, and rapid clearance from blood occurring primarily through the hepatobiliary system. At 20 min, the tumor-to-blood ratio was 1.8. At 1 hr, the tumor uptake was 0.47% injected dose (ID)/g, but decreased to 0.12% ID/g when co-injected with an excess amount of PIA, indicating that accumulation was receptor mediated. These results demonstrate successful $^{99m}TC$ labeling of a peptidomimetic integrin antagonist that accumulated in a tumor via receptor-specific binding. However, tumor uptake was very low because of low blood concentrations that likely resulted from rapid uptake of the agent into the hepatobiliary system. This study suggests that for $^{99m}Tc(CO)_3$-ADA-PIA to be useful as a tumor detection agent, it will be necessary to improve receptor binding affinity and increase the hydrophilicity of the product to minimize rapid hepatobiliary uptake.

카레분 및 향신료 추출물의 항 돌연변이 효과 (Antimutagenic Effects of Extracts of Curry Powder and Its Individual Spice)

  • 정승현;정명수;이진선;박기문
    • 한국축산식품학회지
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    • 제22권4호
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    • pp.352-357
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    • 2002
  • 카레분 및 카레 원료로 사용되는 주요 향신료들의 돌연변이 억제 효과를 보기 위하여 카레분 및 원료 향신료 14종의 추출물에 대한 돌연변이원성 및 항 돌연변이원성 실험을 하였다. 카레분 및 향신료 14종의 추출물에 대해 돌연변이원성 유무를 확인한 결과 돌연변이 원이 없는 것으로 확인되었다. 항 돌연변이원성 실험에서 직접 변이원 2-NF 처리 시Saimonella typhimurium TA 98에 대하여 향신료 추출물 중cinnamon(42%) 및 fenugreek(38%), fennel(32%), ginger(28%), clove(24%)는 p<0.00I 유의수준에서, 그리고 turmeric (23%) 및 celery seed(20%), coriander(16%)는 p<0.01 수준에서 항 돌연변이율을 나타냈다. 그리고 garlic(17%)이 항 돌연변이 활성을 나타냈으며 그 밖의 향신료 및 카레분 추출물은 항 돌연변이 효과가 없었다. 간접변이원 2-AT처리 시 돌연변이 수는 115.0$\pm$46.4에서 clove추출물 첨가에 의해 13.2$\pm$8.1로 감소하여 향신료 추출물 중 clove가 116%로 가장 높은 항 돌연변이율을 보였으며, celery seed(103%) 및 cardamon(100%) 역시 강한 항 돌연변이율을 나타냈다(p<0.01). 그밖에 red pepper, cinnamon, cumin, ginger, fennel, coriander, nutmeg, turmeric에서도 항 돌연변이 활성이 존재하였다(p<0.05). 간접변이원 2-AF에서는 clove추출물이 120%의 가장 높은 항 돌연변이율을 보였으며, cinnamon(113%) 역시 강한 항 돌연변이 활성을 나타냈다(p<0.001). 그리고 cardamon(93%) 및 celery seed (80%), ginger(58%), fennel(44%) 역시 항 돌연변이 활성을 보였다(p<0.05). 그밖에 coriander, black pepper는 항 돌연변이 효과가 나타나지 않았다. 카레분 추출물의 경우, 간접변이원인 2-AT와 2-AF에서 6~23%의 항 돌연변이 율을 나타냈으나 유의성이 없었으며 직접변이원인 2-NF 에서는 항 돌연변이성을 나타내지 않았다. 즉, 동일한 추출물이라도 변이원에 따라 항 돌연변이율이 다르게 확인되었으며, 카레분 및 원료 향신료의 추출물에서 항 돌연변이율은 직접변이원보다는 간접변이원에서 높게 나타났다.

가열 조리된 돼지고기의 Heterocyclic Amines 분석을 위한 Solid-phase 추출 방법의 비교 (Comparison of Different Solid-Phase Extraction Methods for the Analysis of Heterocyclic Amines from Pan-Fried Pork Meat)

  • 이재환;백유미;이광근;신한승
    • 한국축산식품학회지
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    • 제28권5호
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    • pp.637-644
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    • 2008
  • 식품 중 HCAs을 검출하기 위한 최적 전처리 방법을 확립하기 위해 가열 조리된 돼지고기 패티를 이용하여 서로 다른 4가지 SPE(solid-phase extraction)방법을 비교하였다. 4가지 전처리 방법을 통해 얻은 15가지 HCAs 회수율은 3.0%(방법 A, Tri-P-1)-74.7%(방법A, Tri-P-2)이었다. 그 중 $MeA{\alpha}C$가 평균적으로 73.4%로 가장 높은 회수율을 보였으며 Tri-MeIQx가 15.2%의 가장 낮은 회수율을 보였다. 4가지 전처리 방법 중 방법A와 방법D가 가장 높은 회수율과 검출빈도를 보였으며 방법B와 방법C는 Harman(14.8%)을 제외하고는 전혀 검출되지 않았고 회수율을 구할 수 없었다 발암 가능 물질인 IQ, $A{\alpha}C$, $MeA{\alpha}C$, Glu-P-1, Glu-P-2, MeIQ, MeIQx, PhIP 등을 검출하는 방법에는 방법A(48.7-74.6%)가 4가지 방법 중 가장 유리하다. HCAs는 극성에 따라 polar amines과 less-polar amines으로 구분할 수 있는데 방법A는 less-polar amines검출에 유리하고 방법D는 polar amines검출에 유리하다. 방법A와 방법D의 chromatogram을 비교한 결과 방법A와 방법D 모두 15가지 HCAs가 깨끗하게 분리되었지만 Tri-MeIQx 등을 검출하는데 방법A가 더욱 유리하다. SPE 전처리 방법 및 LC/MS 분석방법에 대한 유효성을 확인하기 위해 LOD(0.2-2.1 ng/mL)와 LOQ(0.8-9.7 ng/mL), 표준 편차(0.2-8.6)를 구하였다.