• Title/Summary/Keyword: non-toxicity

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A Comparative Study on Adsorption of PCB Congeners in Mineral Oil by Activated Carbon (활성탄에 의한 광유내 PCB Congeners의 흡착에 관한 비교 연구)

  • Ryoo, Keon Sang
    • Journal of the Korean Chemical Society
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    • v.41 no.5
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    • pp.239-245
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    • 1997
  • The sorption kinetic was studied to evaluate feasibility of removing PCBs from mineral oil with activated carbon. Adsorption efficiency for Aroclor 1242 which is composed of lower chlorinated PCB formulations was $\geq$ 95%, whereas the adsorption efficiency for Aroclor 1260 having higher chlorinated constituents was considerably lower with the efficiency falling to 75%. The observed difference in the adsorption efficiency is attributed to the geometry of PCBs with non-planar and coplanar structure. The concentration of coplanar PCBs is appreciably higher in Aroclor 1242. Since toxicity is primarily associated with coplanar congeners, the preferential adsorption of coplanar congeners by activated carbon accounts for the fact that toxicity reduction can be achieved through this process. The efficiency of process was assessed in terms of Toxicity Equivalence Factor (TEF).

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Single-Dose Intramuscular Toxicity of Mahwangcheonoh Pharmacopuncture in a Rat Model - Toxicity of Mahwangcheonoh Pharmacopuncture in SD Rats -

  • Sung, Heejin;Lee, Eunyong
    • Journal of Pharmacopuncture
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    • v.19 no.4
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    • pp.336-343
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    • 2016
  • Objectives: This study was conducted to analyze the single-dose toxicity and the safety of Mahwangcheonoh pharmacopuncture extracts. Methods: Six-week-old Sprague-Dawley rats were used for this study. Doses of Mahwangcheonoh pharmacopuncture extracts were set at 0.25 mL (low-dose), 0.5 mL (medium-dose) and 1.0 mL (high-dose) for the test groups. A dose of 1.0 mL of normal saline solution was set for the control group. During 14 days, general symptoms, mortalities, and changes in hematology, blood biochemistry and histopathology of all rats were observed. Results: No death was observed in all test groups. Any abnormal symptom was not observed in all of the groups. No significant changes in weight between the control group and the test groups were observed. In addition, no significant differences in the hematology signs, the blood biochemistry levels and the histopathological signs related to the Mahwangcheonoh pharmacopuncture extracts injection were observed. Conclusion: The findings of this study indicate that Mahwangcheonoh pharmacopuncture at doses of 1.0 mL or less may be consider safe and non-toxic. So, it can be used for therapy of obesity sufficiently. But further studies on this subject must be performed to confirm and verify this conclusion.

Mixture Toxicity of Methylisothiazolinone and Propylene Glycol at a Maximum Concentration for Personal Care Products

  • Park, Juyoung;Lee, Handule;Park, Kwangsik
    • Toxicological Research
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    • v.34 no.4
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    • pp.355-361
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    • 2018
  • Methylisothiazolinone (MIT) has been used in combination with methylchloroisothiazolinone (CMIT) for cosmetic products such as shampoo, body lotion, and skin care products. The mixture of CMIT/MIT has been found to cause allergic contact dermatitis and is thus no longer permitted for use as a preservative in leave-on cosmetics. However, MIT itself was approved as a stand-alone preservative at a maximum concentration of 100 ppm as the toxicity was derived from CMIT rather than MIT. However, in many countries, allergic skin irritation caused by MIT remains a social concern. In this study, skin irritation was assessed for the presence of MIT, propylene glycol, and their mixture using a 3D human skin model $EpiDerm^{TM}$. Although non-diluted MIT causes serious skin toxicity, skin irritation was not observed at a concentration of 100 ppm, the maximum permissible level for cosmetics and personal care products according to European regulations. Propylene glycol, the most widely used vehicle for MIT, did not cause skin irritation in the 3D skin model. The results are expected to provide information for regulatory policies and guidelines on the use of biocides in consumer products.

Thoracic Re-irradiation for Locally Recurrent Lung Cancer

  • Aktan, Meryem;Kanyilmaz, Gul;Koc, Mehmet;Aras, Serhat
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.11
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    • pp.5041-5045
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    • 2016
  • Background: Patients with recurrent or progressive lung cancer experience a significant symptom burden, negatively affecting quality of life and reducing life expectancy. Thoracic re-irradiation can be used for palliative treatment to relieve symptoms or as a curative treatment. Methods: Using patient charts, we identified and reviewed 28 cases that had received palliative thoracic re-irradiation for recurrent lung cancer. Results: Before re-irradiation, 32% of patients had stage III non-small cell lung cancer and six had small cell lung cancer. The median interval between treatments was 18.7 months. Median follow-up was 31.2 months from the initial radiotherapy and 5 months after re-irradiation. A better performance status before re-irradiation (<80 vs >80, p=0.09) and a lower overlap 90% isodose (<70 vs >70, p=0.09) showed trends toward improved survival. Grade 1-2 toxicity from re-irradiation was recorded in 12/28 patients, and no grade 3 or 4 acute toxicity was encountered. Conclusion: The role of palliative treatment in survival is not clear but it can provide symptomatic relief in patients, with no high grade toxicity. Further studies with greater patient numbers and longer follow-up times should facilitate determination of the role of this treatment in toxicity and effects on survival.

Effect of Route of Trihalomethanes (THM) Administration on Renal Toxicity in Male Rat

  • Chung, Jin-Ho;Lee, Soo-Hwan
    • Archives of Pharmacal Research
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    • v.14 no.2
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    • pp.188-192
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    • 1991
  • Single non-lethal doses of chloroform $(CHCL_3)$ dichlorobromomethane $(CHCL_2Br)$, dibromochloromethane $(CHCIBr_2)$, or bromoform $(CHBr_3)$ were administered to male rats. Routes of exposure including single intraperitional (ip) and subcutaneous (sc) injection were used in order to permit comparison of severity of THM effects and renal toxicity was assessed at varied times following treatment. On an equimolar basis, sc administration of $CHBr_3$ (either 12 or 3 mmoles/kg) is more effective at increasing KW/BW than ip $CHCI_3$ treatment. Plasma urea nitrogen (BUN) following ip THM injections are markedly increased with all four THM at 24 hours post treatment. BUN response to $CHCL_2Br$ and $CHCIBr_3$-effected BUN levels have essentially returned to those of vehicle control. THM sc treatment results in a BUN response similar to that seen following ip treatment, with only the time course being different. With the exception of $CHCL_3$, sc and ip-treatments appear to be equally effective in evoking absolute BUN elevations. These results suggest that THM administration induce renal toxicity dependent upon the route or exposure.

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Bioaccumulation and Baseline Toxicity of Hydrophobic Chemicals: Molecular Size Cutoff, Kinetic Limitations, and Chemical Activity Cut-off (소수성화학물질의 생물축적과 기저독성: 분자크기, 반응속도, 화학적 활성도에 따른 제약)

  • Kwon, Jung-Hwan
    • Environmental Analysis Health and Toxicology
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    • v.23 no.2
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    • pp.67-77
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    • 2008
  • It has been observed that the linear relationship between the logarithm of bioconcentration factor (log BCF) of highly hydrophobic chemicals and their log $K_{ow}$ breaks when log $K_{ow}$ becomes greater than 6.0. Consequently, super hydrophobic chemicals were not thought to cause baseline toxicity as a single compound. Researchers often call this phenomenon as "hydrophobicity cutoff" meaning that bioconcentration or corresponding baseline toxicity has a certain cutoff at high log $K_{ow}$ value of hydrophobic organic pollutants. The underlying assumption is that the increased molecular size with increasing hydrophobicity prohibits highly hydrophobic compounds from crossing biological membranes. However, there are debates among scientists about mechanisms and at which log $K_{ow}$ this phenomenon occurs. This paper reviews three hypotheses to explain observed "cutoff": steric effects, kinetic or physiological limitations, and chemical activity cutoff. Although the critical molecular size that makes biological membranes not permeable to hydrophobic organic chemicals is uncertain, size effects in combination with kinetic limitation would explain observed non-linearity between log BCF and log $K_{ow}$. Chemical activity of hydrophobic chemicals generally decreases with increasing melting point at their aqueous solubility. Thus, there may be a chemical activity cutoff of baseline toxicity if there is a critical chemical activity over which baseline effects can be observed.

Acute Oral Toxicity and Pathogenicity of a Potential Probiotic Bacillus sp. A9184 Isolated from Soybean Paste

  • Lim, Jong-Hwan;Park, Byung-Kwon;Kim, Myoung-Seok;Rhee, Man-Hee;Park, Seung-Chun;Yun, Hyo-In
    • Toxicological Research
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    • v.20 no.4
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    • pp.359-363
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    • 2004
  • This study provides more information about the potential toxicological risk of Bacillus sp. A9184 isolated from soybean paste. The evaluation was based on the guidelines of acute oral toxicity/pathogenicity for microbial pesticide and was to get more comprehensive understanding on the acute toxicity of the potential probiotic in Sprgue-Dawley rats. No dead animal was observed in rats after single oral administration with bacteria ($10^8$ CFU per animal). There were neither no treatment-related changes in clinical signs, nor changes in body weight and body temperature as com-pared with the untreated group. All tested animal showed the increase in body weight with time. The results obtained in this study suggest that the potential probiotic, Bacillus sp. A9184, is non-toxic for rat.

Arsenic Toxicity in Male Reproduction and Development

  • Kim, Yoon-Jae;Kim, Jong-Min
    • Development and Reproduction
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    • v.19 no.4
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    • pp.167-180
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    • 2015
  • Arsenic is a toxic metalloid that exists ubiquitously in the environment, and affects global health problems due to its carcinogenicity. In most populations, the main source of arsenic exposure is the drinking water. In drinking water, chronic exposure to arsenic is associated with increased risks of various cancers including those of skin, lung, bladder, and liver, as well as numerous other non-cancer diseases including gastrointestinal and cardiovascular diseases, diabetes, and neurologic and cognitive problems. Recent emerging evidences suggest that arsenic exposure affects the reproductive and developmental toxicity. Prenatal exposure to inorganic arsenic causes adverse pregnancy outcomes and children's health problems. Some epidemiological studies have reported that arsenic exposure induces premature delivery, spontaneous abortion, and stillbirth. In animal studies, inorganic arsenic also causes fetal malformation, growth retardation, and fetal death. These toxic effects depend on dose, route and gestation periods of arsenic exposure. In males, inorganic arsenic causes reproductive dysfunctions including reductions of the testis weights, accessory sex organs weights, and epididymal sperm counts. In addition, inorganic arsenic exposure also induces alterations of spermatogenesis, reductions of testosterone and gonadotrophins, and disruptions of steroidogenesis. However, the reproductive and developmental problems following arsenic exposure are poorly understood, and the molecular mechanism of arsenic-induced reproductive toxicity remains unclear. Thus, we further investigated several possible mechanisms underlying arsenic-induced reproductive toxicity.

Early Life Stage Toxicity of 2,3,7,8,-Tetrachlorodibenzop-Dioxin(TCDD) in Goldfish(Carassius auratus) (금붕어 수정난의 2,3,7,8-TCDD 노출에 따른 다이옥신 관련 유전자의 발현 및 형태학적 변화)

  • Oh, Seung-Min;Ryu, Byung-Taek;Kim, Ha-Ryong;Chung, Kyu-Hyuck
    • Environmental Analysis Health and Toxicology
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    • v.24 no.1
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    • pp.1-8
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    • 2009
  • In this study, we obtained the fertilized eggs from goldfish(Carassius auratus) and observed normal developmental stage(from fertilized eggs to larvae) in non-exposed groups. Goldfish embryos at 3 h postfertilization(hpf) were statically exposed for 1 h to either dimethylsufoxide(DMSO, 0.1%, v/v) or TCDD($0.5{\mu}g/L$). Toxicity and morphological changes were characterized from 3 to 120 h postfertilization(hpf). Egg mortality($0{\sim}48$ hpf) and hatching ratio($72{\sim}83$ hpf) in TCDD-exposed group were significantly different from control groups. However, pericardial edema was first observed at 72 hpf, followed by the onset of yolk sac edema and mortality. In addition, goldfish embryos-larvae exposed to TCDD significantly increased TCDD-related gene such as CYP1A($24{\sim}72$ hpf) and AhR2(72 hpf). This is the first study about in-depth characterization of TCDD-induced developmental toxicity in goldfish(Carassius auratus).

Efficiency Estimation of Toxicity Free Eire Resistance Cable

  • Yoon, Hun-Ju;Hon, Jin-Woong
    • Transactions on Electrical and Electronic Materials
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    • v.3 no.3
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    • pp.34-38
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    • 2002
  • In this paper, efficiency estimation of toxicity fee fire resistance cable experiments was measured smoke density of toxicity free fire resistance polyolefin insulation material and electric field dependence of tree shape in low density polyethylene (LDPE). One of the most serious causes of failure in high-voltage cables, can be an electrical discharge across an internal gab or void in the insulating material. Treeing due to partial discharge is one of the main causes of breakdown in the insulating materials and reduction of the insulation life. Therefore the necessity for establishing a method to diagnose the aging of insulation materials and to predict the breakdown of insulation and research of the fire resistance character has become important. First, we have studied on electric field dependence of tree shape in LDPE about treeing phenomena occurring on the high electrical field. Second, the measurement method is the attenuation quantity of irradiation by smoke accumulating with in a closed chamber due to non-flaming heat decomposition and flaming combustion. A main cause of fire-growth and generating toxic gas when, it bums, should be dealt with great care in life. safety design. The fire gases were occurred carbon monoxide and decomposition than in polyolefin due to incomplete combustion of PVC, which has high content of carbon in chemical compound.