- Effects of Bisphenol A on the Placental Function and Reproduction in Rats.
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Chae Kwan Lee, Seog Hyun Kim, Deog Hwan Moon, Jeong Ho Kim, Byung Chul Son, Dae Hwan Kim, Chang Hee Lee, Hwi Dong Kim, Jung Won Kim, Jong Eun Kim, Chae Un Lee
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J Prev Med Public Health. 2005;38(3):330-336.
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 Abstract
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- OBJECTIVE
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 (160 g +/- 20 g) 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.
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Summary
- A study on the productivity of physicians operating clinic in Kyeongsangnamdo.
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Jeong Ho Kim, Kwi Won Jeong, Jin Ho Chun, Chae Un Lee, Ki Taek Pae, Kong Hyun Kim, Hae Rim Shin, Hyung Jong Park
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Korean J Prev Med. 1991;24(2):171-180.
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Abstract
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- Productivity analysis of physician is one of essential factors for the optimal health manpower planning. Among 690 physicians operating clinic and registered on the Kyeongsangnamdo Medical Association, 623 physicians were studied with a structural questionnaire from April 1 to May 31, 1990. This study covers the general characteristics and productivity of physicians and attempts to find relevant determinants of their productivity through stepwise multiple regression analysis based on collected data. The major results were as follows. First, physicians were more prevalent 35~44 group (38.2%) in age, male (95.8%) in sex, specialist (76.5%) in specialization, city (78.0%) in geographical location. Age group of 35-54 and specialist were more prevalent in cities than in counties, while age group of 25-44 and 55 over and general practitioner in counties (p<0.001). Second, daily outpatient load of all physician were 77.1 persons on average. Age group of 35~44 had the most outpatient load (90.3 persons) among all age group, 6~10 years group (94.2 persons) in years of duration of practice, 11 hours per day group (83.4 persons) in working hours per day. Specialists had more outpatient load (82.6 persons) than general practitioners (61.1 persons) and physicians in cities had more (80.2 persons) than physicians in counties (66.3 persons). Daily average outpatient load of physicians were significantly different by their age, speciality, number of assistants and years of practice (p<0.001) and working location (p<0.05), but not significantly different by working hours per day of physician (p>0.1). Third, the productivity of physicians operating clinic were significantly affected by the three factorsnumber of assistants of physician, age of physician and duration of practice at the current clinic. Age of physician had negative regression coefficient.
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