• Title/Summary/Keyword: repeated exposure

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An Analysis of Consumers' Problematic Complaining Behaviors and Firms' Reactions (소비자의 악성불평행동 분석 및 기업의 대처행동 조사 연구)

  • Huh, Kyung-Ok
    • Journal of Families and Better Life
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    • v.30 no.6
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    • pp.167-181
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    • 2012
  • This study analyzed consumer's harsh complaining behaviors and firm's reactions toward consumers' harsh complaining behavior, and investigated the differences in the firms' reactions according to the characteristics of counselors and customer service centers. In addition, this study attempted to find a strategy and provide guidance regarding consumer's harsh complaining behaviors. The results of this study are discussed below. First, consumer's harsh complaining attitudes were expressed by crude language, violent language, threats, personal attacks, and claims of a high-ranking social position. Consumer's directive, complaining behaviors were repeated on the telephone, and threats of prosecution or disclosure to the public, exposure of habitual product returns, and requests for interviews with superiorsat the representative firm were made. Second, a firm typologies according to its reaction style toward a consumer's harsh complaining behaviors were as follows: Group 1, having a neutral attitude toward consumers and preparation thoroughly regarding their demands; Group 2, having a negative attitude toward consumers and some degree of preparation toward consumers' demands; and finally, Group 3, having a positive attitude toward consumers but offering insufficient reparation regarding consumers' demands. Third, female counselors, counselors having a certified counselor's license, and those much experience working in labor work were more likely to be in Group 3. Male counselors, part-time counselors, and those having experience of many years were more likely to be in Group 2. Group 1 were more likely to have large number of workers at customer service centers, male counselors, and to have large numbers of educational training programs related to the reactions of consumers in the form of dissatisfaction, complaints, how to offer compensation for injuries to consumers, and issues related to PL(product liability). In addition, Group 1 also had more firm level welfare policies related to hight stress levels of consumer counselors and extra types of support regarding harsh consumers. However, Group 2 members were more likely to provide excessive compensation and rewards to harsh consumers. Finally, to react to consumer's harsh complaint efficiently, it was suggested that firms should not treat consumers as harsh consumers, should react to consumers' complaints sincerely, and should take precautionary management efforts as regards consumer dissatisfaction based on better quality control of products. In addition, it was deemed necessary to formulate a management strategy to train competent consumer counselors with a high quality of counselor skill, having standardized and consistent reaction guidance toward consumer complaints and thorough knowledge of compensation rules for consumer injuries and subsequent guidance.

Treatment of Multiple Pulmonary Arteriovenous Fistulas with Therapeutic Embolization in Osler-Rendu-Weber Syndrome (Osler-Rendu-Weber 증후군 환자에서 색전요법을 이용한 다발성 폐동정맥루 치험 1예)

  • Kim, Jae-Hag;Choi, Taek-Hee;Nam, Seung-Mo;Chang, Jae-Jin;Park, Yeon-Hee;Hur, Nam-Hyun;Choe, Du-Hwan;Lee, Byung-Hee;Kim, You-Cheoul;Lee, Choon-Taek
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.4
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    • pp.914-921
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    • 1997
  • Hereditary hemorrhagic telangiectasia(Osler-Rendu-Weber Syndrome) is characterized by telangiectasia of the skin and mucous membranes and intermittent bleeding from vascular abnormalities. About 20% of patients with this syndrome have pulmonary arteriovenous fistulas. Pulmonary arteriovenous fistula is uncommon malformation which has an abnormal connection between the pulmonary capillary bed, in which venous blood in the pulmonary artery is shunted through the fistula into the pulmonary vein without exposure to alveolar oxygen and result in unoxygenated, desaturated systemic arterial blood, polycythemia, cyanosis and clubbing. Death often results from cerebral abscess and rupture of the malformation with massive hemorrhage. Therapeutic intervention is recommended for all symptomatic patients because of the risk of those serious complications. Treatment options include surgery and transcatheter obliteration with steel coils or detachable balloons. Therapeutic embolization has the advantages that multiple bilateral pulmonary arteriovenous fistulas can be occluded and also that the procedure can be repeated if necessary. Recently we experienced a case of the multiple bilateral pulmonary arteriovenous fistulas associated with telangiectatic change of hepatic artery and multiple angiodysplasia on the gastric mucosa in 41 years old female patient who had mild dyspnea of exertion(NYHA class II). clubbing finger, severe iron deficiency anemia. She was treated with embolization technique using steel coils and iron replacement. After the therapeutic embolization. significant improvement of dyspnea of exertion with disappearance of multiple pulmonary nodule on follow-up simple chest x-ray was noted. During the subsequent six months follow-up period, she had the improvement of symptoms and iron deficiency anemia.

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Effect of Dang Gui Bo Hyul-tang on fatigue types of Mibyeong (피로형 미병에 대한 당귀보혈탕의 효과)

  • Park, Sun Haeng;Sung, Yoon-Young;Jang, Seol;Lee, Siwoo;Kim, Hong Jun;Kim, Ho Kyoung
    • Journal of Society of Preventive Korean Medicine
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    • v.20 no.3
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    • pp.55-65
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    • 2016
  • Objectives : Mibyeong is a korea medicine have original concept of the disease. However, no previous report has effect of mibyeong herbal medicine in fatigue types of mibyeong. This study investigated the question of whether Dang Gui Bo Hyul-tang(DGBHT) of effect on fatigue types of Mibyeong. Methods : C57BL/6 mice were randomaly divided into three group (n=10). The mice were then group (1) Nocontrol, (2) Restraunt stress(veh), (3) Dang Gui Bo Hyul-tang 200mg/kg. The administered Dang Gui Bo Hyul-tang 200mg/kg or distilled water (orally) 1 hr prior to daily exposure to repeated restraint stress (2 h) for 15 days. The performed behavior test (Mechanical hyperalgesia test,, Open-field test, Forced swimming test, Sucrose preference test and immunostaining and biochemical measured in serum. Results : Stress fatigue induced mices significantly increased lethargic, hyperalgesia through behavior test (Mechanical hyperalgesia test (decrease 43%), Open-field test ($4,809{\pm} 226.13cm$ vs. $3121{\pm}226.64cm$), Forced swimming test ($11.45{\pm}3.96$ vs. $79.10{\pm}8.12sec$), Sucrose preference test (decrease 58%)). In addition, chronic fatigue model evidently increased corticosterone level ($122.54{\pm}18.88$ vs. $186.94{\pm}18.26ng/ml$), AST level ($46.22{\pm}3.23$ vs. $31.40{\pm}3.86U/L$), ALT level ($38.78{\pm}5.72$ vs. $17.60{\pm}1.30$), liver necrosis, lateral ventricle size. These alterations were significantly ameliorated by DGBHT. DGBHT significantly attend the elevated serum concentrations of corticosterone ($155.90{\pm}6.29ng/ml$), AST ($31.40{\pm}3.86U/L$), ALT ($17.60{\pm}1.30U/L$). Moreover, DGBHT improved lethargic, hyperalgesia when compared the stress fatigue (Mechanical hyperalgesia test (improve 28%), Open-field test ($4,038{\pm}615.81cm$), Forced swimming test ($7.56{\pm}1.88sec$), Sucrose preference test (increase 21%) Conclusions : Theses result suggest that DGBHT have improved lethargic, hyperalgesia and fatigue-associated hormone and liver protective on stress fatigue model. It will be necessary to research to present evidences on benefits and effects of Korean medical treatment for Mibyeong through clinical researches based on benefits and effects of those animal models.

Reduced Effect of kV-CBCT Dose by Use of Shielding Materials in Radiation Therapy (방사선 치료 시 차폐물질 사용에 따른 kV-CBCT 선량감소 효과)

  • Jo, Hyeonjong;Park, Euntae;Kim, Junghoon
    • Journal of the Korean Society of Radiology
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    • v.12 no.4
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    • pp.467-474
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    • 2018
  • CBCT is useful for improving the accuracy of the treatment site, but Repeated use increases the exposure dose. In this study, we aimed to provide basic data for dose reduction in CBCT implementation by dataization the simulating and dose reduction effect using shielding substance. Material in this study, Analyzation the photon beam by simulate the CBCT Through MCNPX and then calculate the absorption dose of body organ at shooting moment of thoracic abdominal position as target UF-Revise simulated body. At this time. Dose reduction effects at this time were evaluated according to the texture of materials and presence of shielding materials( lead, antimony, barium, sulfate, tungsten, bismuth). When CBCT was taken without shielding, the dose was calculated to be high in the breast and spine, and the dose in the esophagus and lung was calculated to be low. The doses according to the shield material were calculated as barium sulfate, antimony, bismuth, lead, and tungsten. The shielding rate was the highest in the thymus (73.6%) and the breast (59.9%) compared with the dose reduction according to presence or absence of the shield. However, it showed the lowest shielding rate in lung (2.1%) and spine (12.6%).

Teratogenicity Study of tert-Butyl Acetate in Rats (랫드에서 초산 제3부틸의 최기형성 시험)

  • Ahn, Tai-Hwan;Yang, Young-Su;Lee, Jong-Chan;Kang, Seong-Soo;Bae, Chun-Sik;Kim, Sung-Ho;Kim, Jong-Choon;Kim, Hyeon-Yeong;Chung, Yong-Hyun
    • Toxicological Research
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    • v.23 no.2
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    • pp.151-158
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    • 2007
  • tert-Butyl acetate is an organic solvent used for coatings, industrial cleaning, and surface treatment applications. This study investigated the potential adverse effects of tert-butyl acetate on pregnant dams and embryo-fetal development after maternal exposure on gestational days 6 through 19 in rats. The test chemical was administered to pregnant rats by gavage at dose levels of 0, 500, 1,000, 1,500, and 2,000 mg/kg/day. All dams were subjected to a caesarean section on day 20 of gestation and their fetuses were examined for any external, visceral, and skeletal abnormalities. At 2,000 mg/kg, treatment-related clinical signs, including piloerection, abnormal gait, decreased locomotor activity, loss of fur, reddish tear, anorexia, nasal discharge, vocalization and coma, were observed in a dose-dependent manner. All dams died between the 2nd day and 5th day of treatment due to a severe systemic toxicity. At 1,500 mg/kg, minimal maternal toxicity including an increase in the incidence of decreased locomotor activity and loss of fur, and an increase in the weights of adrenal glands and liver was observed. On the contrary, no significant adverse effect on the embryo-fetal development was detected. There were no adverse effects on either pregnant dams or embryo-fetal development at <1,000 mg/kg. These results show that a 14-day repeated oral dose of tert-butyl acetate in rats caused a minimal maternal toxicity including increases in the incidence of clinical signs and the weights of adrenal glands and liver, but no embryotoxicity and teratogenicity at 1,500 mg/kg/day. Under these experimental conditions, the no-observed-adverse-effect level (NOAEL) of tert-butyl acetate is estimated to be 1,000 mg/kg per day for dams and 1,500 mg/kg per day for embryo-fetal development.

Effects of Hypobaric Conditions on Apoptosis Signalling Pathways in HeLa Cells

  • Arican, Gul Ozcan;Khalilia, Walid;Serbes, Ugur;Akman, Gizem;Cetin, Idil;Arican, Ercan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.12
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    • pp.5043-5047
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    • 2014
  • Nowadays increasing effectiveness in cancer therapy and investigation of formation of new strategies that enhance antiproliferative activity against target organs has become a subject of interest. Although the molecular mechanisms of apoptosis can not be fully explained, it is known that cell suicide program existing in their memory genetically is activated by pathophysiological conditions and events such as oxidative stress. Low pressure (hypobaric) conditions that create hypoxia promote apoptosis by inhibiting cell cycling. In this study, determination of the effects of fractional hypobaric applications at different times on HeLa cells at cellular and molecular levels were targeted. Experiments were carried out under hypobaric conditions (35.2 kPa) in a specially designed hypobaric cabin including 2% $O_2$ and 98% N. Application of fractional hypobaric conditions was repeated two times for 3 hours with an interval of 24 hours. At the end of the implementation period cells were allowed to incubate for 24 hours for activation of repair mechanisms. Cell kinetic parameters such as growth rate (MTT) and apoptotic index were used in determination of the effect of hypobaric conditions on HeLa cells. Also in our study expression levels of the Bcl-2 gene family that have regulatory roles in apoptosis were determined by the RT-PCR technique to evaluate molecular mechanisms. The results showed that antiproliferative effect of hypobaric conditions on HeLa cells started three hours from the time of application and increased depending on the period of exposure. While there was a significant decrease in growth rate values, there was a significant increase in apoptotic index values (p<0.01). Also molecular studies showed that hypobaric conditions caused a significant increase in expression level of proapoptotic gene Bax and significant decrease in antiapoptotic Bfl-1. Consequently fractional application of hypobaric conditions on HeLa cell cultures increased both antiproliferative and apoptotic effects and these effects were triggered by the Bax gene.

Altered Vascular Calcium Regulation in Hypertension

  • Kim, Won-Jae;Lee, Jong-Un;Park, Yong-Hyun;Nam, Sang-Chae
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.5
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    • pp.529-535
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    • 1997
  • The present study was aimed at investigating whether the vascular calcium regulation is altered in hypertension. Two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension were made in rats, and their thoracic aortae were taken 4 weeks later. The isometric contractile response and calcium uptake of the endothelium-denuded aortic preparations were determined. Caffeine ($0.1{\sim}35\;mmol/L$) induced a greater contraction in 2K1C and DOCA-salt hypertension than in normotensive control. When the vascular calcium store was functionally-depleted by a repeated exposure to caffeine, it took longer to reload the store and to resume the initial contraction force in response to caffeine in both 2K1C and DOCA-salt hypertension. The vascular $^{45}Ca$ uptake following the functional depletion of the cellular store was also greater in both models of hypertension than in control. Ryanodine, calcium channel activator of the sarcoplasmic reticulum, attenuated the restoration of caffeine-induced vascular contraction, which was not affected by either 2K1C or DOCA-salt hypertension. Nifedipine, an L-type $Ca^{2+}$ channel blocker, attenuated the restoration of caffeine-induced contraction, which was not affected by DOCA-salt hypertension, but was more pronounced in 2K1C hypertension. Nifedipine also diminished the vascular $^{45}Ca$ uptake, which was not affected by DOCA-salt hypertension, but was more pronounced in 2K1C hypertension. Ouabain, a $Na^+,\;K^+-ATPase$ inhibitor, increased the caffeine-induced contraction by a similar magnitude in control and 2K1C hypertension, which was, however, markedly attenuated in DOCA-salt hypertension. Ouabain enhanced the vascular $^{45}Ca$ uptake, the degree of which was not affected by 2K1C hypertension, but was markedly attenuated in DOCA-salt hypertension compared with that in control. Cyclopiazonic acid, a selective inhibitor of $Ca^{2+}-ATPase$ of the sarcoplasmic reticulum, attenuated the restoration of caffeine-induced contraction, which was not affected by 2K1C hypertension, but was more marked in DOCA-salt hypertension. These results suggest that the increased vascular calcium storage may be attributed to an enhanced calcium influx in 2K1C hypertension, and to an impaired $Na^+-K^+$ pump activity of the cell membrane and subsequently increased calcium pump activity of the cellular store in DOCA-salt hypertension.

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Spontaneous bone regeneration after surgical extraction of a horizontally impacted mandibular third molar: a retrospective panoramic radiograph analysis

  • Kim, Eugene;Eo, Mi Young;Nguyen, Truc Thi Hoang;Yang, Hoon Joo;Myoung, Hoon;Kim, Soung Min
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.41
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    • pp.4.1-4.10
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    • 2019
  • Background: The mandibular third molar (M3) is typically the last permanent tooth to erupt because of insufficient space and thick soft tissues covering its surface. Problems such as alveolar bone loss, development of a periodontal pocket, exposure of cementum, gingival recession, and dental caries can be found in the adjacent second molars (M2) following M3 extraction. The specific aims of the study were to assess the amount and rate of bone regeneration on the distal surface of M2 and to evaluate the aspects of bone regeneration in terms of varying degree of impaction. Methods: Four series of panoramic radiographic images were obtained from the selected cases, including images from the first visit, immediately after extraction, 6 weeks, and 6 months after extraction. ImageJ software® (NIH, USA) was used to measure linear distance from the region of interest to the distal root of the adjacent M2. Radiographic infrabony defect (RID) values were calculated from the measured radiographic bone height and cementoenamel junction with distortion compensation. Repeated measures of analysis of variance and one-way analysis of variance were conducted to analyze the statistical significant difference between RID and time, and a Spearman correlation test was conducted to assess the relationship between Pederson's difficulty index (DI) and RID. Results: A large RID (> 6 mm) can be reduced gradually and consistently over time. More than half of the samples recovered nearly to their normal healthy condition (RID ≤ 3 mm) by the 6-month follow-up. DI affected the first 6 weeks of post-extraction period and only showed a significant positive correlation with respect to the difference between baseline and final RID. Conclusions: Additional treatments on M2 for a minimum of 6 months after an M3 extraction could be recommended. Although DI may affect bone regeneration during the early healing period, further study is required to elucidate any possible factors associated with the healing process. The DI does not cause any long-term adverse effects on bone regeneration after surgical extraction.

Placenta Transfer and Toxicokinetics of Valproic Acid in Pregnant Cynomolgus Monkeys

  • Jeong, Eun-Ju;Yu, Wook-Joon;Kim, Choong-Yong;Chung, Moon-Koo
    • Toxicological Research
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    • v.26 no.4
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    • pp.275-283
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    • 2010
  • Placenta transfer study in non-human primate (NHP) is one of the crucial components in the assessment of developmental toxicity because of the similarity between NHP and humans. To establish the method to determine placenta transfer in non-human primate, toxicokinetics of valproic acid (VPA), a drug used to treat epilepsy in pregnant women, were determined in pregnant cynomolgus monkeys. After mating, pregnancy-proven females were daily administered with VPA at dose levels of 0, 20, 60 and 180 mg/kg by oral route during the organogenesis period from gestation day (GD) 20 to 50. Concentrations of VPA and its metabolite, 4-ene-VPA, in maternal plasma on GDs 20 and 50, and concentrations of VPA and 4-ene-VPA in placenta, amniotic fluid and fetus on GD 50 were analyzed using LC/MS/MS. Following single oral administration of VPA to pregnant monkeys, concentrations of VPA and 4-ene-VPA were generally quantifiable in the plasma from all treatment groups up to 4-24 hours post-dose, demonstrating that VPA was absorbed and the monkeys were systemically exposed to VPA and 4-ene-VPA. After repeated administration of VPA to the monkeys, VPA was detected in amniotic fluid, placenta and fetus from all treatment groups, demonstrating that VPA was transferred via placenta and the fetus was exposed to VPA, and the exposures were increased with increasing dose. Concentrations of 4-ene-VPA in amniotic fluid and fetus were below the limit of quantification, but small amount of 4-ene-VPA was detected in placenta. In conclusion, pregnant monkeys were exposed to VPA and 4-ene-VPA after oral administration of VPA at dose levels of 20, 60 and 180 mg/kg during the organogenesis period. VPA was transferred via placenta and the fetus was exposed to VPA with dose-dependent exposure. The metabolite, 4-ene VPA, was not detected in both amniotic fluid and fetus, but small amount of 4-ene-VPA was detected in placenta. These results demonstrated that proper procedures to investigate placenta transfer in NHP, such as mating and diagnosis of pregnancy via examining gestational sac with ultrasonography, collection of amniotic fluid, placenta and fetus after Caesarean section followed by adequate bioanalysis and toxicokinetic analysis, were established in this study using cynomolugus monkeys.

Molecular Mechanism of Tetrabromobisphenol A (TBBPA)-induced Target Organ Toxicity in Sprague-Dawley Male Rats

  • Choi, Jae-Seok;Lee, Young-Jun;Kim, Tae-Hyung;Lim, Hyun-Jung;Ahn, Mee-Young;Kwack, Seung-Jun;Kang, Tae-Seok;Park, Kui-Lea;Lee, Jae-Won;Kim, Nam-Deuk;Jeong, Tae-Cheon;Kim, Sang-Geum;Jeong, Hye-Gwang;Lee, Byung-Mu;Kim, Hyung-Sik
    • Toxicological Research
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    • v.27 no.2
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    • pp.61-70
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    • 2011
  • Brominated flame retardants (BFRs) are present in many consumer products ranging from fabrics to plastics and electronics. Wide use of flame retardants can pose an environmental hazard, which makes it important to determine the mechanism of their toxicity. In the present study, dose-dependent toxicity of tetrabromobisphenol A (TBBPA), a flame retardant, was examined in male prepubertal rats (postnatal day 18) treated orally with TBBPA at 0, 125, 250 or 500 mg/kg for 30 days. There were no differences in body weight gain between the control and TBBPA-treated groups. However, absolute and relative liver weights were significantly increased in high dose of TBBPA-treated groups. TBBPA treatment led to significant induction of CYP2B1 and constitutive androstane receptor (CAR) expression in the liver. In addition, serum thyroxin (T4) concentration was significantly reduced in the TBBPA treated group. These results indicate that repeated exposure to TBBPA induces drug-metabolising enzymes in rats through the CAR signaling pathway. In particular, TBBPA efficiently produced reactive oxygen species (ROS) through CYP2B1 induction in rats. We measured 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage, in the kidney, liver and testes of rats following TBBPA treatment. As expected, TBBPA strongly induced the production of 8-OHdG in the testis and kidney. These observations suggest that TBBPA-induced target organ toxicity may be due to ROS produced by metabolism of TBBPA in Sprague-Dawley rats.