• Toxicological Research
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• 제27권4호
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• pp.247-251
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• 2011

To clarify whether inhibitory effect of estrogen on liver tumor is associated with cell proliferation, we investigated its role in diethylnitrosamine (DEN)-induced rat preneoplastic lesions, with time sequenced manners. F344 male rats (n = 90) were divided into three groups at 5 weeks of age. The mini-osmotic pumps providing a continuous infusion of DEN was implanted into the abdominal cavity of each animal in group 1, 2 and 3 at 6 weeks of age. To see the effect of estrogen, pellet containing 1 or 10 ${\mu}g$ of estradiol-3-benzoate (EB) was implanted subcutaneously in the animals of groups 2 or 3, respectively, one week prior to DEN treatment. Ten animals of each group were euthanized at 10, 14 and 18 weeks after DEN treatment. Liver tissues at each time point were fixed in 10% phosphate-buffered formalin and were processed and embedded in paraffin and 5 ${\mu}g$ sections mounted on a silanized slide. Glutathione S-transferase placental form (GST-P) positive foci and 5-bromo-2-deoxyuridine (BrdU) labeling cells were detected at each time point. Area of GST-P positive foci in DEN+EB 1 or 10 ${\mu}g$ group was significantly decreased compared to DEN alone at 14 weeks (p < 0.01 or p < 0.05, respectively) an at 18 weeks (p < 0.05 or p < 0.01, respectively). BrdU index in DEN+EB 1 or 10 ${\mu}g$ groups was significantly decreased compared to DEN alone at 14 weeks and at 18 weeks (p < 0.01). Taken together, we conclude that EB treatment decrease the DEN-induced liver preneoplastic lesions and this may be associated with decrease of cellular proliferation.

• Journal of Preventive Medicine and Public Health
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• 제38권3호
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• pp.330-336
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• 2005

Objectives : The aim of this study was to investigate the effects of bisphenol A (BPA), an estrogen-like environmental endocrine disrupter, on the placental function and reproduction in rats. The mRNA levels of the placental prolactin-growth hormone(PRL-GH) gene family, placental trophoblast cell frequency and reproductive data were analyzed. Methods : The pregnancies of F344 Fisher rats ($160g{\pm}20g$) were detected by the presence of the copulatory plug or sperm in the vaginal smear, which marked Day 0 of pregnancy. Pregnant rats were divided into three groups. The control group was intraperitoneally injected with a sesame oil vehicle. The two remaining groups were injected with 50 or 500 mg/kg B.W/day of BPA, resuspended in sesame oil, on either days 7 to 11 or 16 to 20 of pregnancy, with the rats sacrificed on either day 11 or 20, respectively. The mRNA levels of PRL-GH and Pit-1a and b isotype genes were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction. The hormone concentrations were analyzed by radioimmunoassay, and the frequency of the placental trophoblast cells observed by a histochemical study. Reproductive data, such as the placental weight and litter size, were surveyed on day 20. The fetal weight was surveyed for 4 weeks after birth. A statistical analysis was carried out using the SAS program (version 8.1). Results : The mRNA levels of the PRL-GH gene family, such as placental lactogen I, Iv and II, prolactin like protein A, C and Cv, and decidual prolactin-related protein were significantly reduced due to BPA exposure. The mRNA levels of the Pit-1a and b isotype genes, which induce the expression of the PRL-GH gene family in the rat placenta, were also reduced due to BPA exposure. The PL-Iv and PL-II concentrations were reduced in the BPA exposed group. During the middle to last stage of pregnancy (Days 11-20), a high dose of BPA exposure reduced the frequency of spongiotrophoblast cells, which are responsible for the secretion of the PRL-GH hormones. Reproductive data, such as the placental and fetal weights and the litter size, were reduced, but that of the pregnancy period was extended in the BPA exposed compared to the control group. Conclusions : BPA disrupts the placental functions in rats, which leads to reproductive disorders.

• Journal of Preventive Medicine and Public Health
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• 제37권2호
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• pp.157-165
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• 2004

Objectives : This study aimed to investigate the toxic effects of chromium (VI) on the placental function and reproduction in rats. For the study, the placental prolactin-growth hormone (PRL-GH) gene expression, placental trophoblast cell differentiation and reproductive data were analyzed. Methods : The pregnancies of F344 Fisher rats were checked by the presence of a copulatory plug or sperm in the vaginal smear, which was defined as day 0 of the pregnancy. Pregnant rats were divided into the three groups. The control group was given tap water (chromium level < 0.001 ppm) and the remaining groups were given 250 or 750 ppm of chromium (VI) [as potassium dichromate], from day 7 to 19 of the pregnancy. Rats were sacrificed at days 11 and 20 of pregnancy. The mRNA levels of PRL-GH and Pit-1a and b isotype genes were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction (RT-PCR). The hormonal concentration was analyzed by radioimmunoassay, and the differentiation of placental trophoblast cells were observed by histochemical studies. Reproductive data, such as placental and fetal weights, pregnancy period, and litter size, were surveyed at day 20 of pregnancy and after birth. A statistical analysis was carried out using the SAS program (version 8.1). Results : The mRNA levels of the prolactin-growth hormone (PRL-GH) family of genes were dose dependently reduced by chromium exposure. The mRNA levels of Pit-1a and b isotype genes that induce the expression of the PRL-GH family of genes were also reduced by chromium exposure. The PRL-GH hormonal concentration in the rat placenta, fetus and maternal blood were decreased by chromium exposure. In the middle stage of pregnancy (day 11), a high dose of chromium suppressed the differentiation of spongiotrophoblast cells that secret the PRLGH hormones. In the last stage of pregnancy (day 20), a high dose of chromium induced apoptosis of placental cells. Reproductive data, such as placental and fetal weights, litter size, were reduced, but the pregnancy period was extended in the group exposed to chromium compared with the controls. Conclusion : Chromium (VI) disrupts the ordered functions of the placenta, which leads to reproductive disorders in rats.

• 한국발생생물학회지:발생과생식
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• 제13권4호
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• pp.321-327
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• 2009

망간은 정소 독성을 나타내며, 뇌기저핵에 작용하여 혈청 프로락틴의 농도를 증가시킨다. 그리고 혈청 프로락틴 농도 상승에 의한 과프로락틴혈증(hyperprolactinemia)은 정소의 정자 생성을 억제한다. 본 연구에서는 망간의 전신 노출이 흰쥐 정소의 정자 생산과 혈청 프로락틴 농도에 미치는 영향을 조사하기 위하여 실험동물을 대조군 $(0.0mg/m^3)$과 망간 노출군 (Mn $1.5mg/m^3$)으로 나누고, 노출군은 다시 노출 기간에 따라 4주와 13주 노출군 등 4군으로 분류하였다(n=10). 노출 기간에 따라 실험동물의 체중 변화와 사료 섭취량 등 일반적 소견 관찰, 혈액과 정소의 망간 농도, 정자의 수와 기형 등을 관찰하였다. 그리고 망간 노출에 따른 혈청 프로락틴 농도를 조사하여 망간 노출 조건에 따른 혈청 프로락틴 농도 변화 및 정소 독성을 조사하였다. 망간 노출 4주 및 13주군에서 노출기간에 따라 혈액 및 정소의 망간 농도가 유의하게 증가되었다. 대조군에 비하여 망간 노출군에서 노출기간에 따라 정자의 수가 감소되었으며, small head와 bent tail 등 기형 정자의 빈도는 증가하였다. 혈청 프로락틴의 농도는 망간 투여군에서 대조군에 비하여 유의하게 증가하였다. 그러나 실험동물의 체중 변화 및 사료 섭취량은 실험군간에 차이가 없었다. 이러한 결과들로 보아 $1.5mg/m^3$ 농도의 아만성 망간 노출은 흰쥐의 혈청 프로락틴 농도를 증가시키고, 정소 독성의 원인으로 추정된다. 그리고 전신 노출에 의한 망간의 흰쥐 정소 독성의 무유해영향농도(NOAEL)는 $1.5mg/m^3$ 이하로 예측된다.

• Journal of Chest Surgery
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• 제36권3호
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• pp.131-135
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• 2003

Glutaraldehyde (GA)에 보존한 이종보철편들은 생체 이식 후 석회화 변성을 보이는 문제점을 나타내므로 이 단점을 보완하기 위해 연구자는 GA 용액에 Mg염을 첨가 칼슘의 반응을 막아 석회화를 완화하며 더불어 chitosan 및 glutamate 등의 아미노산으로 후처치하여 석회화 완화를 극대화하고자 하였다. 대상 및 방법: 우심낭을 정방형 조각으로 만들어 40조각의 우심낭편은 대조군으로 MgC1$_2$6$H_2O$를 4g/L 첨가한 0.625% GA 용액에 보존하고(1군), 40조각은 이 GA 용액에 보관하다 이식 24시간 전 2% chitosan 용액에 옮겨 보존(2군), 또 다른 40조각 역시 같은 방법으로 8% glutamate 용액에 후처치(3군)하여, 이들을 40마리의 백서 복부 피하에 각각 한 조각씩 이식하여 1개월, 2개월, 3개월 및 4개월째에 적출, spectophotometry로 침착한 칼슘을 정량하였다. 결과： 이식 후 1개월 및 2개월에는 세균간의 석회화 정도에 차이가 없었으나. 3개월째에는 1군 5.45$\pm$0.42 mg/g, 2군 3.22$\pm$1.31 mg/g, 3군 4.20$\pm$0.55 mg/g의 통계적 차이를 보여, 2군에서 유의한 석회화 완화 효과가 관찰되고 있고 (p<0.05), 4개월째에는 1군 6.01$\pm$1.21 mg/g, 2군 3.78$\pm$1.82 mg/g, 3군 3.92$\pm$0.92 mg/g으로 2, 3군에서 유의한 석회화 완화 효과를 보여주고 있다(p<0.05). 결론: 즉 2% chitosan 후처치로 3개월의 시간이 경과함에 따라 피하에 이식된 보철편의 석회화가 완화되었으며 8% glutamate는 4개월에서 그 완화효과를 보여주고 있다.다. 현대의 실정 에 맞는 과학적 제조방법을 이용하여 산업화한다면 재래식으로 인해 걸리는 시간, 노력 에 걸맞은 가격, 품질 등을 유지해 나갈 수 있으리라 본다.는 음식 10위를 조사한 결과 선호음식의 경우 저체중군과 정상군의 경우 순위는 달랐지만 10위에 선별된 음식들이 주로 과 (수박, 귤, 딸기, 복숭아, 바나나, 포도, 사과)과 음료수(사이다, 환타) 등 열량밀도가 낮고 수분함량이 높은 식품인 반면 과체중군은 햄버거, 돈까스, 튀김 만두, 샌드위치, 쇠고기 및 돼지고기 구이 등이 선호음식 10위내에 포함되어 정상군이나 저체중군보다 고지방.고단백 음식들의 기호도가 과체중군에서 높음을 확인하였다., 단맛을 좋아하는 사람이 싫어하는 사람보다 열량과 당질섭취량은 유의 적으로 적게, 지방 섭취량은 유의적으로 높았다. 짠맛을 좋아하는 사람은 나트륨 섭취량이 7890 mg으로 짠맛을 싫어하는 사람 5579 mg보다 유의적 (p < 0.05)으로 많은 양을 섭취하였다.고, Ca : P 중량비가 각각 2.63$\pm$1.99, 1.79$\pm$0.39, 2.80$\pm$0.53, 8.35$\pm$12.87이었으며, Ca : Mg 중량비는 각각 11.86$\pm$540, 9.29$\pm$1.34, 9.09$\pm$2.09, 32.50$\pm$41.35이었다. 칼슘과 마그네슘의 흡수에 영향을 미치는 P : Mg 분자량비는 곡류가공품이 4.11$\pm$1.54, 라면류가 4.17$\pm$0.67, 레토르트식품은 2.58$\pm$0.45, 음료류는 2.59$\pm$2.50으로 나타났다. 위의 연구결과에서 볼 때 시료의 93.0%가 실제측정값이 표시량의 80% 이상이어야