• 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.

• Journal of radiological science and technology
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• v.37 no.1
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• pp.21-28
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• 2014

Cultured pancreatic beta cells and nerve cells, it is given normal condition of 10% FBS (fetal bovine serum), 11.1 mM glucose and hyperglycemia codition of 1% FBS, 30 mM glucose. For low LET X-ray irradiated with 0.5 Gy/hr dose-rate(total dose: 0.5 to 5 Gy). Survival rates were measured by MTT assay. When non irradiated, differentiated in the pancreatic beta cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a small reduction. However increasing the total dose of X-ray, the survival rate of normal conditions decreased slightly compared to the survival rate of hyperglycemia conditions, the synergistic effect was drastically reduced. When non irradiated, undifferentiated in the nerve cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a large reduction. As the cumulative dose of X-ray normal conditions and hyperglycemia were all relatively rapid cell death. But the rate of decreased survivals by almost parallel to the reduction proceed and it didn't show synergistic effect.

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.150-156
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• 1999

The induction of proliferation of adult rat islets was investigated under various culture conditions. The islets were isolated from male Sprague-Dawley rats and subsequently embedded in collagen gels, which mimic the in vivo three-dimensional surroundings. During the culture period, the effects of heterologous serum (fetal bovine serum, FBS), epidermal growth factor (EGF), and retinoic acid (RA) on islet growth were examined with respect to the morphological and total DNA content changes. To investigate these changes at the cellular level, whole mount immunocytochemistry using specific antibodies for insulin and glucagon was performed. The results showed that (i) collagen gels as an extracellular matrix can maintain islets in a similar way to that in vivo, (ii) heterologous serum (FBS) had stimulatory effects on islet proliferation in a dose-dependent manner, (iii) RA had inhibitory effects on islet proliferation induced by the serum in a dose-dependent manner, (iv) EGF had weak inhibitory effects on islet proliferation induced by the serum except at the concentration of 10 nM where its effect was not significant, and (v) whole mount immunocytochemistry revealed that newly proliferated islet cells were mainly $\beta$-and $\alpha$-cells.

• Biomolecules & Therapeutics
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• v.9 no.4
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• pp.311-317
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• 2001

YHB6211, a newly developed recombinant human granulocyte colonystimulating factor, was administered at dose levels of 0, 3, 15, and 75 $\mu$g/kg/day intravenously to the pregnant New Zealand White rabbits (20 rabbits per group) during the organogenetic period, days 6 to 18 of gestation. All dams were subjected to Caesarian section on day 28 of gestation and their fetuses were examined for external, visceral, and skeletal abnormalities. No abnormalities in clinical signs, body weight changes, gross findings, mortality, and external appearance were found in all dams and fetuses exposed to 0, 3, and 15 $\mu$g/kg/day of YHB6211. However, in the group treated with 75 $\mu\textrm{g}$/kg/day of YHB6211, maternal body and uterine weights, fetal body weights and length, and the number of live fetuses were significantly decreased and further fetal mortality was remarkably increased. It is suggested that YHB6211 may have no side effect up to the dose level of 15 $\mu$g/kg/day, and there would be no teratogenicity for fetuses of rabbits up to 75 $\mu\textrm{g}$/kg/day even if it may have some toxic effects over 75$\mu\textrm{g}$/kg/day for dams and fetuses of rabbits.

• Toxicological Research
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• v.17 no.3
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• pp.225-234
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• 2001

The present study was conducted to investigate the effects of Korean red ginseng water extract (KRGWE) on developmental toxicity caused by the environmental estrogen bisphenol A (BPA) in Sprague-Dawley rats. fifty males successfully mated were randomly assigned to five experimental groups, 1.e., group I (vehicle control), group II (BPA 1000mg/kg), group III (KRGWE 400mg/kg), group IV (BPA 1000mg/kg & KRGWE 200mg/kg), and group V (BPA 1000mg/kg & KRGWE 400mg/kg). The test articles were administered by gavage to mated females from gestational days (GD) 1 through 20 (sperm vaginal lavage=day O). All females were subjected to caesarean section on GD 21 and their fetuses were examined for external, visceral, and skeletal abnormalities. In the group II, significant maternal toxic effects including suppressed body weight, decreased body weight gain during pregnancy, and reduced food consumption were observed in pregnant rats. The minimal developmental toxicity including fetal ossification delay was also found in fetuses. In addition, a tendency for increased pregnancy failure, increased pre-and postimplantation loss, and decreased fetal body weight was observed. However, no fetal morpho-logical abnormalities were seen in surviving fetuses at a dose level of 1000mg BPA/kg. On the other hand, the maternal toxicity and developmental toxicity found in the groups IV and V were comparable to those of the group II. There were no adverse signs of either maternal toxicity or developmental toxicity in the group III. These results showed that administration of BPA at a dose level of 1000mg/kg to pregnant rats resulted in significant maternal toxicity and minimal developmental toxicity, and that no protective effects on BPA-induced maternal toxicity and developmental toxicity were found by concomitant gavage dosing of KRGWE.

• Toxicological Research
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• v.26 no.3
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• pp.209-216
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• 2010

Limb bud (LB) and central nerve system (CNS) cells were prepared from 12.5 day old pregnant female Crj:CD (SD) rats and treated with olaquindox and vitamin A. Cytotoxicity and inhibition on differentiation were measured in each cell. Three doses of olaquindox (4, 21 and 100 mgkg), and 0.2 and 75 mg/kg of vitamin A were administered to pregnant rat for 11 days from $6^{th}$ to $16^{th}$ of pregnancy. $IC_{50}$ values of olaquindox for proliferation and differentiation in CNS cell were 22.74 and $28.32\;{\mu}g/ml$ and 79.34 and $23.29\;{\mu}g/ml$ in LB cell and those values of vitamin A were 8.13 and $5.94\;{\mu}g/ml$ in CNS cell and 0.81 and $0.05\;{\mu}g/ml$ in LB cell, respectively. Mean body weights of pregnant rats were decreased at high dose of olaquindox (110 mg/kg) but relative ovary weight, number of corpus lutea, and number of implantation were not changed. Resorption and dead fetus were increased at high dose of olaquindox, and relative ovary weight, the number of corpus lutea and implantation, and sex ratio of male to female were not significantly changed in all dose of olaquindox. Mean fetal and placenta weights were significantly (p < 0.01) decreased in rats of high group. Seven fetuses out of 103 showed external anomaly like bent tail, and 10 out of 114 fetuses showed visceral anomalies at high group. The ossification of sternebrae and metacarpals were significantly (p < 0.01) increased by low and middle dose of olaquindox but it was significantly (p < 0.01) prohibited by high dose of olaquindox. In rats treated with vitamin A, the resorption and dead fetus were increased by high dose. Mean fetal weights were significantly (p < 0.01) increased by low dose but significantly (p < 0.01) decreased by high dose. Thirty four fetuses out of 52 showed external anomaly; bent tail (1), cranioarchschisis (14), exencephaly (14), dome shaped head (22), anophthalmia (15), brcahynathia (10) and others (19). Forty five fetuses out of 52 showed soft tissue anomaly; cleft palate (42/52) and anophthalmia (22/52) by high dose of vitamin A. Sixty one fetuses out of 61 (85.2%) showed skull anomaly; defect of frontal, partial and occipital bone (21/61), defect of palatine bone (52/61) and others (50/61). In summary, we support that vitamin A is strong teratogen based on our micromass and in vivo data, and olaquindox has a weak teratogenic potential in LB cell but not in CNS cell. We provide the in vivo evidence that a high dose of olaquindox could have weak embryotoxic potential in rats.

• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.17-27
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• 1996

The purpose of this study was to evaluate the decreasing effects of Korean garlic against the accumulation of mercury levels in maternal and fetal organs in pregnant Fischer 344 rats, based on the theory and information that neutral amino acids have protective effects against mercury poisoning and garlic contains a large of neutral amino acids. The results obtained are as follows: 1. On the 20th day of gestation, the maternal body weight in 20 mg/wt$\cdot$kg methyl mercuric chloride groups was 76.1% of those in control group, but those recovered to be 81.2% and 93.6% by treating with garlic (0.5 g/wt$\cdot$kg and 1.0 g/wt$\cdot$kg). 2. The mercury levels in maternal organs were reduced 6.2% and 47.2% (p<0.05) in kidney, 8.2% and 42.1% (p<0.05) in spleen, 9.7% and 40.9% (p<0.05) in blood, 35.6% (p<0.05) and 67.2% (p<0.05) in liver, 38.0% (p<0.05) and 57.6% (p<0.05) in brain, by treating with garlic (0.5 g/wt$\cdot$kg and 1.0 g/wt$\cdot$kg). 3. The mercury levels were reduced 22.4% and 44.3% (p<0.05) in placenta, and 34.7% (p<0.05) and 54.9% (p<0.05) in fetal body, by treating with garlic (0.5 g/wt$\cdot$kg and 1.0 g/wt$\cdot$kg). 4. The mercury levels in fetal organs were reduced 17.5% and 46.7% (p<0.05) in kidney, 15.1% and 37.0% (p<0.05) in brain, 30.2% (p<0.05) and 46.7% (p<0.05) in liver, by treating with garlic (0.5 g/wt$\cdot$kg and 1.0 g/wt$\cdot$kg). 5. Mercury levels in maternal kidney were 6.73~7.71 times higher than those in fetal kidney, but those in fetal liver and brain were 1.67~2.25 times and 1.98~2.93 times higher than those in maternal liver and brain, respectively. In conclusion, Korean garlic decrease the accumulation of mercury levels in maternal and fetal organs in pregnant Fischer 344 rats as increasing the dose.

• Communications for Statistical Applications and Methods
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• v.29 no.2
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• pp.239-250
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• 2022

In many applications, we frequently encounter correlated multiple outcomes measured on the same subject. Joint modeling of such multiple outcomes can improve efficiency of inference compared to independent modeling. For instance, in developmental toxicity studies, fetal weight and number of malformed pups are measured on the pregnant dams exposed to different levels of a toxic substance, in which the association between such outcomes should be taken into account in the model. The number of malformations may possibly have many zeros, which should be analyzed via zero-inflated count models. Motivated by applications in developmental toxicity studies, we propose a Bayesian joint modeling framework for continuous and count outcomes with excess zeros. In our model, zero-inflated Poisson (ZIP) regression model would be used to describe count data, and a subject-specific random effects would account for the correlation across the two outcomes. We implement a Bayesian approach using MCMC procedure with data augmentation method and adaptive rejection sampling. We apply our proposed model to dose-response analysis in a developmental toxicity study to estimate the benchmark dose in a risk assessment.

• Journal of Life Science
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• v.11 no.5
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• pp.447-456
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• 2001

We have recently demonstrated that the fluoroquinolone antibacterial DW-116 caused a significant developmental toxicity in rats. The present study was conducted to determine whether the development toxicity induced by DW-116 treatment was the result of malnutrition fro reduced food intake or the direct effects of test chemical on conceptuses. The test chemical was administered by gavage to pregnant rats from gestational days 6 through 16 at dose levels of 0 and 500 mg/kg/day. A pair-feeding study was also performed in which the pregnant rats received the same amount of diet consumed by the DW-116-treated pregnant rats. All dams were subjected to caesarean section on day 20 of gestation and their fetuses were examined for examined for external, visceral, and skeletal abnormalities. In this treatment group, the maternal toxicities included increased abnormal clinical signs, decreased maternal body weight, suppressed body weight gain during treatment and posttreatment periods, and reduced food intake. The significant developmental toxicities included increased fetal deaths, decreased live fetuses, reduced fetal body weight and placental weight, increased incidence of fetal abnormalities, and increased fetal ossification delay. In this pair-fed group, however, slight maternal toxicities including decreased body weight and suppressed body weight gain during treatment period were observed in comparison with the control group, and minimal development toxicities including reduced fetal and placental weights and increased fetal ossification delay were found. The number of fetal deaths and live fetuses, and the incidences of malformed fetuses and litters with affected fetuses were comparable to the control values. Based on the results, it could be concluded that the development toxicity observed in the treatment group is attributable to the direct effects of Dw-116 treatment, but not to the maternal malnutrition from reduced food consumption during pregnancy.

• YAKHAK HOEJI
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• v.42 no.5
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• pp.534-539
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• 1998

Effect of recombinant human epidermal growth factor (rhEGF, DWP401) on fetal external, visceral and skeletal malformation during organogenesis was examined. Pregnant Sprauge-Daw ley rats were administered with 0.2, 1 and 5mg/kg/day subcutaneously on gestation day 6 through 16. Dams were sacrified at 20th day of gestation. Materal body weight, food consumption and clinical observation were not changed. Significant dose-dependent increase of relative and absolute liver weight were observed in the treatment group, whereas other organ weights were not changed. Placental weight of 1 and 5mg/kg/day group and number of resorption in 5mg/kg/day treatment group were significantly increased. External and visceral malformation of fetuses were not observed with treatment. However, skeletal variations(increase of asymmetry sternebrae, decrease of dumb-bell and asymmetry sternbrae at 5mg/kg/day, and fused stemebrae at 5mg/kg/day) were observed. These results showed that rhEGF (DWP401) may not have embryo and/or fetal developmental toxicity effect in rats.