• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.203-203
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• 2002

The present study was conducted to investigate the potential embryo-fetal toxicity of 2-bromopropane(2-BP) in rats. The test agent was subcutaneously administered to pregnant rats from gestational day 6 to 19 at dose level of 0, 500, 1000, 1500 mg/kg.(omitted)

• 대한방사선기술학회지:방사선기술과학
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• 제14권2호
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• pp.37-44
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• 1991

The combined effect of radiation and ultrasound has been studied in mouse embryos. Radiation and/or ultrasound were adminstered to ICR mice on day 8 of gestation. Intrauterine death, gross malformation, and fetal body weight were selected as indicators of effects. Does of whole-body ${\gamma}-irradiation$ were 0.5 to 2.5 Gy and those of ultrasound were $0.5\;W/cm^2$ to $3\;W/cm^2$. Intrautrine mortality increased with increasing radiation dose ; this trend was more remarkable in combination with ultrasound. Gross malformations such as exencephaly and anophthalmia/microphthalmia appeared frequently in the fetuses treated with both radiation and ultrasound. Decreased fetal weight was observed even in mice treated with 1.5 Gy of radiation or $1\;W/cm^2$ of ultrasound. There was a linear relationship between dose and reduction of fetal weight. The fetal weight was sensitive, precise and easy-to-handle indicator for the effects of growth retardation. Intrauterine mortality and frequencies of exencephaly and anophthalmia/microphthalmia were higher than the sum of those induced by radiation and by ultrasound. The results indicatied that the combined action of radiation and ultrasound on intrauterine death and malformations was synergistic.

• Toxicological Research
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• 제19권3호
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• pp.227-234
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• 2003

2-Bromopropane (2-BP), a halogenated propane analogue, is a substitute for chlorofluorocarbones (CFCs) which have a great potential to destroy the ozone layer and to warm the earth's environment. The present study was undertaken to evaluate the potential adverse effects of 2-BP on pregnant dams and embryo-fetal development after maternal exposure during the gestational days (GD) 6 through 17 in ICR mice. The test chemical was administered subcutaneously to pregnant mice at dose levels of 0, 313, 625 or 1,250 mg/kg/day. All dams were subjected to caesarean section on GD 18 and their fetuses were examined for external, visceral and skeletal abnormalities. In the 1,250 mg/kg group, maternal toxicity included an increase in the incidence of abnormal clinical signs and a decrease in the maternal body weight, body weight gain, and corrected body weight. Developmental toxicity included a decrease in the fetal body weight, a reduction in the placental weight, an increase in the fetal skeletal variation and ossification delay. There were no adverse effects on either pregnant dams or embryo-fetal development in the 313 and 625 mg/kg groups. These results suggest that a 12-day subcutaneous dose of 2-BP is embryotoxic at a maternally toxic dose (i.e., 1,250 mg/kg/day) in ICR mice. In the present experimental condition, the no-observed-adverse-effect level of 2-BP is considered to be 625 mg/kg/day for dams and embryo-fetuses, respectively.

• Animal cells and systems
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• 제1권2호
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• pp.337-340
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• 1997

The purpose of this study is to evaluate whether water soluble chitosan, a natural nontoxic chelator, can reduce fetal contamination of radiostrontium in pregnant mice. Various forms of water soluble chitosans (10% or 1% powder, or 1% solution) were given to pregnant mice before or after contamination of 0.005 uCi/B.W(g) Sr-85. Transplacental transfer of Sr-85 to fetus was $6.8{\pm}2.7%$ of injected dose, when Sr-85 was administered at the 20th day of pregnancy. Fetal radioactivity was significantly reduced when mother mice were treated with water soluble chitosan before contamination of Sr-85. Water soluble chitosans of 10% or 1% powder, or 1% solution significantly reduced fetal retention of Sr-85 to $2.3{\pm}0.7%$, $2.7{\pm}0.8%$, and $2.0{\pm}0.9%$, respectively. However, fetal contamination was not reduced, when water soluble chitosans of 10% or 1% powder, or 1% solution were administered after maternal contamination of Sr-85. From these data we can conclude that water soluble chitosan could reduce fetal contamination of radiostrontium in pregnant mice, when given before the pregnant mice were exposed to radiostrontium.

• 생약학회지
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• 제28권4호
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• pp.286-292
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• 1997

We studied the screening condition for immune regulatory responsor. We focused on the T-lymphocytes leer this purpose. Mouse fetal thymic organ culture (FTOC) system and flow cytometric analysis were mainly used in this experiment. Even if FTOC is carried out in vivo condition, the pattern of thymic development in the condition of FTOC is similar to that of in vivo condition. In this regard, FTOC system might be very powerful tool to screen the immune regulator, especially concerning on T cells. To establish the optimum condition of FTOC to screen the Immune regulator, we focused on the optimum amount of dose and culture period. The cell number and surface antigens on T cells were also analysed by using hemacytometer and flow cytometer. To monitor the differentiation event, anti-CD3, anti-CD4 and anti-CD8 antibodies were used. Alkoxyglycerol and Phellodendri Cortex were used fur positive and negative control, respectively. Astragalus membranceus was used as test sample. From our analysis, we reached to conclusions that the best dose of extract is $50\;{\mu}g/ml$ of culture medium, the best culture period is for 9 days, and ethanol used as solvent has no toxicity to FTOC.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 춘계학술대회 논문집
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• pp.45-45
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• 2003

The present study was conducted to investigate the potential embryo-fetal toxicity of Artesunate, an antimalarial drug, in Sprague-Dawley rats. The test item was orally administered by gavage to pregnant rats (22 females per group) from days 6 through 15 of gestation at dose levels of 0, 2, 4 and 8 mg/kg/ day. (omitted)

• Biomolecules & Therapeutics
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• 제6권2호
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• pp.151-158
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• 1998

Aspalatone, a new antithrombotic agent, was administered orally to pregnant Sprague-Dawley rats during the organogenetic period at dose levels of 0, 20, 100 and 500 mg/kg/day. All dams were subjected to caesarean section on day 20 of pregnancy. Effects of test substance on dams and embryonic development of F1 fetuses were examined There were treatment-related decreases in body weight and food consumption in the 500 mg/kg group. There was a increase in the spleen weight in the 100 and 500 mg/kg groups. Develo-pmental toxicity was evident as decreased fetal body weights and increased fetal malformations in the 500 mg/ kg group. External and skeletal malformations of fetuses occurred at an incidence of 1 and 8.2%, respectively. In addition, there was a delay in ossification of sternebrae and sacrocaudal vertebrae in the 500 mg/kg group. The results show that the no observed adverse effect dose level (NOAEL) for maternal toxicity was 20 mg/kg/ day and for developmental toxicity was 100 mg/kg/day.

• Journal of Radiation Protection and Research
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• 제21권4호
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• pp.273-284
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• 1996

착상전기(着床前期}의 태아(胎兒)는 방사선(放射線)을 비롯한 많은 환경요인(環境要因)에 대하여 감수성(感受性)이 높은 개체(個體)임에도 불구하고 특히 이 시기는 임신부(姙娠婦)가 자각(自覺)적으로 임신을 감지할 수 없는 시기이기에 이러한 여러 환경유해요인으로부터 의도적으로 피할 수가 없다. 그러므로 착상전기의 영향을 충분히 검토한 후에 의료행위를 취할 것이며 이에 대한 방어(防禦)대책도 검토할 필요가 있다. 종래 까지 방사선에 대한 태아영향에 관한 많은 연구결과에 의하면 방사선 및 그 외의 유해요인에 대한 착상전기의 영향은 배사망(胚死亡)(유산(流産))만이 일어나며 기형(奇形)은 유발(誘發)하지 않는다고 하여 발생학(發生學)등 여러 교과서에서 기형은 기관형성기(器官形戚期)만이 국한(局限)해서 일어나는 영향이라고 단정되어 왔었다. 그러나 이 연구결과 착상전기에 있어서도 기형이 유발하여 오히려 기관형성기((器官形成期)보다도 감수성이 높다는 것이다. 또한 착상전기에서도 기형유발의 시기특이성을 가지며 여러 종류의 기형이 발생한다는 것이 본 연구로부터 밝혀졌다. 실험동물은 ICR Mouse를 사용했다. ICR Mouse는 일반적으로 태아사망 및 기형실험에 널리 사용되는 것이다. 사육조건은 Conventional 한 조건하에서 사육했으며 Mating 방법(方法)은 Female 마우스의 발정기(Sexual Excitement period)에 있는 mouse 질(膣)을 육안 적으로 관찰하여 $AM 6:00{\sim}AM 9:00$시까지 3시간만 mate시켰다. AM9:00시에 Vaginal Plug를 관찰하여 임신을 확인했다. Plug가 확인 된 마우스는 AM8:00시에 수정(Conception)된 것으로 가정하고 이 시점을 임신 0일 0시로 수정 난의 태아연령을 산정했다. 방사선조사는 $^{135}Cs\;{\gamma}-$선을 사용하였으며 임신 마우스의 전신조사를 실시하고 조사한 시기는 각 2, 48, 72, 96hpc이며 조사한 방사선 선량 군은 $0.1{\sim}2.5Gy$이다. 태아영향 관찰지표는 태아 연령은 mate일 오전 8:00시를 임신 0일 0시로 환산하여 태아연령 18일에 임신마우스를 Cervical vertebral dislocation에 의해 도살했다. 도살 후 해부하여 각 임신 마우스별로 관찰했다. 착상 율을 관찰하기 위하여 황체수를 세었고, 태아사망과 생존태아를 구별했다. 자궁 내 사망의 분류는 태아사망을 1) preimplantation death 2) Embryonic death 3) Fetal death로 분류했다. 착상전사망은 수정후 $0{\sim}4.5$일(1세포기${\sim}$배반포후기 부화까지)까지의 사망으로써 난소의 황체수(배란 수)와 착상태아(생존태아, 착상흔, 태반유잔, 흡수태아, 침연태아의 합계)로부터 구할 수 있다. Embonic death는 수정 후 $4.5{\sim}13$일까지의 사망으로써 Implantation sites, Placental remnants, Resorption of fetus로 관찰된 것이다. Fetal death는 수정후 $14{\sim}18$일까지의 사망으로써 Maceration of fetus로 관찰되는 것이다. 통계학적 분석은 각 Group의 착상 을과 자궁 내 사망 율을 산출할 때에는 각 임신마우스에 따라 발생빈도가 크게 다르기 때문에 통계처리에는 Non parametric 검정인 Kluskal Wallis 검정을 사용하여 분석하였다. 또한 개체 Level 영향인 착상을, 태아사망, 기형의 threshold dose의 산정에 대해서는 SAS-Logistic 검정에 따라 통계 분석을 하여 $5%(Ld_5,\;ED_5)$ 및 $10%{\times}2/3$점을 threshold dose로 판단했다. 태아체 중에 대해서는 parametric검정인 t-test검정에 의하여 분석했다. 그 결과 착상전기에서도 기형이 유발하며 특히 시기에 따라 일어나는 때와 일어나지 않는 때가 있음을 본 연구로부터 밝혀졌다. 또한 착상전기의 영향으로써 유발되는 기형은 여러 종류의 기형이 발생함이 밝혀졌다. 특히 이시기는 착상전 사망 및 배(胚)사망은 방사선 선량에 따라 크게 일어나나 태아사망(Fetal death) 및 태아체중은 유의차(有意差)가 없었다.

• Neonatal Medicine
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• 제28권1호
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• pp.59-63
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• 2021

An important, albeit rare, cause of fetal bradycardia is long QT syndrome (LQTS). Congenital LQTS is an ion channelopathy caused by mutations in genes encoding cardiac ion channel proteins. Fetal onset of LQTS imposes high risk of life-threatening tachyarrhythmias and sudden cardiac death. Here, we report the case of a female newborn with fetal onset of bradycardia and a 2:1 atrioventricular (AV) block. After birth, a 12-lead electrocardiogram (ECG) revealed bradycardia with QT prolongation of a corrected QT (QTc) interval of 680 ms and pseudo 2:1 AV block. Genetic testing identified a heterozygous Gly402Ser (c.1204G>A) mutation in CACNA1C, confirming the diagnosis of LQTS type 8 (LQT8). The patient received propranolol at a daily dose of 2 mg/kg. Mexiletine was subsequently administered owing to the sustained prolongation of the QT interval and pseudo 2:1 AV block. One week after mexiletine inception, the ECG still showed QT interval prolongation (QTc, 632 ms), but no AV block was observed. There were no life-threatening tachyarrhythmias in a follow-up period of 13 months.

• The Korean Journal of Physiology
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• 제18권1호
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• pp.1-8
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• 1984

In order to determine the extent of the placental transfer of Lithium ion, pregnant rabbits at $27{\sim}29$ days of gestation, which has hemochorial placenta similar to the human placenta, received 2 mM/Kg of $Li^+$ in the form of LiCl intravenously. Maternal arterial blood, placental sinus blood, fetal blood, amniotic fluid and maternal urine were drawn two hours after the single dose of LiCl. Concentrations of $Li^+$, $Na^+$, $K^+$ and osmolarity were measured in plasma of collected bloods, amniotic fluid and urine. Followings are the results obtained. 1) Evident level of $Li^+$ was detected in fetal blood, although fetal plasma concentration of $Li^+$ found to be almost one third of maternal plasma. 2) Plasma concentration of $Li^+$ in placental sinus blood was higher than that in fetal plasma but lower than that in maternal plasma. It means that downward concentration gradient of $Li^+$ from mother to fetus was still remarkable two hours after the injection. 3) Significant level of $Li^+$ was also detected in amniotic fluid. It seemed likely that $Li^+$, at least in part, excreted by the fetal urinary tract. 4) There were no differences in $Na^+$ and osmolar concentration between fetal and maternal blood. 5) From above results, it was concluded that $Li^+$ may transfer across the placenta but limited passage capacity through placental barrier for $Li^+$ is significant, beacause net transfer assumed to be going on even at two hours, at which time maternal equlibrium has been reached.