Perception of and attitude toward ethical issues among Korean occupational physicians.

BACKGROUND: Occupational physicians (OPs) have complex relationships with employees, employers, and the general public. OPs may have simultaneous obligations towards third parties, which can lead to variable conflicts of interests. Among the various studies of ethical issues related to OPs, few have focused on the Korean OPs. The aim of the present survey was to investigate the ethical contexts, the practical resolutions, and the ethical principles for the Korean OPs. METHODS: An email with a self-administered questionnaire was sent to members of the Korean Society of Occupational and Environmental Medicine, comprising 150 specialists and 130 residents. The questionnaire was also distributed to 52 specialists and 46 residents who attended the annual meeting of the Korean Association of Occupational and Environmental Clinics in October 2015, and to 240 specialists by uploading the questionnaire to the online community 'oem-doctors' in February 2016. The responses to each question (perception of general ethical conflicts, recognition of various ethical codes for OPs, core professional values in ethics of occupational medicine, and a mock case study) were compared between specialists and residents by the chi-squared test and Fisher's exact test. RESULTS: Responses were received from 80 specialists and 71 residents. Most participants had experienced ethical conflicts at work and felt the need for systematic education and training. OPs suffered the most ethical conflicts in decisions regarding occupational health examination and evaluation for work relatedness. Over 60% of total participants were unaware of the ethical codes of other countries. Participants thought 'consideration of worker's health and safety' (26.0%) and 'neutrality' (24.7%) as the prominent ethical values in professionality ofoccupational medicine. In mock cases, participants chose beneficence and justice for fitness for work and confidential information acquired while on duty, and beneficence and respect for autonomy in pre-placement examinations. CONCLUSIONS: This study evaluated the current perception of and attitude toward ethical issues among the Korean OPs. These findings will facilitate the development of a code of ethics and the ethical decision-making program forthe Korean OPs.

Blood lead concentration and related factors in Korea from the 2008 National Survey for Environmental Pollutants in the Human Body.

This study evaluated blood lead concentrations in the Korean general population and the correlation between various exposure sources using data from the 2008 Korea National Survey for Environmental Pollutants in the Human Body (National Institute of Environmental Research, Korea). The general and occupational characteristics were gathered from 5136 participants who were 20 years of age and older using a structured questionnaire. Blood lead concentrations were analyzed using an atomic absorption spectrophotometer. Statistical analysis was performed using multiple linear regressions of the log lead concentrations to the independent variables such as age, gender, smoke, herbal medication and drug consumption, drinking water, and living area. Geometric mean (GM) blood lead concentrations in Korean adults were 19.7 µg/l. The blood lead concentrations increased with age; the highest concentrations were found in the 50-69-year age group (p<0.001). Males were higher than in females (p<0.001). Current smokers and drinkers had higher concentrations than nonsmokers (p<0.001) and nondrinkers (p<0.001), respectively. People who took herbal medication and drug consumption were higher than those who did not (p<0.001). Education level was negatively associated with blood lead concentration (p<0.001). People living in or around industrial areas had elevated blood lead concentration (p<0.001). Family income was also negatively associated with lead concentration, but not significantly. For drinking water, the underground water (spring or well water) drinking group had higher concentrations than other types of water drinking groups, but not significantly (p=0.063). The blood lead concentrations by occupation were significant (p<0.034): the highest was in laborer and Agricultural-Fishery-Forestry and the lowest in office workers. In women, blood lead concentrations tended to decrease with increasing delivery times, but not significantly. The blood lead concentration (GM) of the general adult population in Korea has decreased over time from 45.8 µg/l (1999) to 19.7 µg/l (2008). Although it is still higher than in other countries such as the United States and Canada, it is rapidly decreasing. Gender, age, smoking and alcohol drinking status, herbal medication and drug consumption, education level, living area and occupation were significantly related to the blood lead concentrations in Korea.

Effects of manganese exposure on dopamine and prolactin production in rat.

Although manganese (Mn) has been shown to increase prolactin (PRL) by decreasing dopamine (DA) in the hypothalamus, the mechanism of Mn-induced regulation of the hypothalamic-hypophyseal-pituitary axis is unclear. We assessed the effects of inhaled Mn on hypothalamic DA and pituitary PRL production and evaluated the role of pituitary-specific transacting factor 1 (Pit-1), a transacting factor of PRL gene, in Mn-induced changes in PRL secretion in the rat brain. Male rats exposed to Mn for 4 or 13 weeks (1.5 mg/m3, 6 h/day, 5 days/week) showed a progressive and significant decrease in hypothalamic DA, whereas PRL and Pit-1 mRNA levels increased in response to Mn exposure. These results suggest that exposure to Mn decreases hypothalamic DA and promotes the production of PRL in the pituitary and that Pit-1 might be a regulator of DA and PRL.

Munc18 plays an important role in the regulation of glutamate release during female puberty onset.

Munc18, a mammalian homolog of C. elegans Unc, is essential for neurotransmitter release. The aim of this study was to identify estrogen-dependent expression of Munc18-1 and its role in the regulation of glutamate release for puberty onset. Hypothalamic munc18-1 mRNA levels were significantly increased by estrogen treatment in ovariectomized, immature female rats. During pubertal development, the munc18-1 mRNA levels dramatically increased between the juvenile period and the anestrous phase of puberty. Intracerebroventricular administration of an antisense oligodeoxynucleotide against munc18-1 mRNA significantly decreased glutamate release and delayed the day of puberty onset. These results suggest that Munc18-1, expressed in an estrogen-dependent manner, plays an important role in the onset of female puberty via the regulation of glutamate release.

Gastrodia elata blume and an active component, p-hydroxybenzyl alcohol reduce focal ischemic brain injury through antioxidant related gene expressions.

Ischaemic stroke is a leading cause of death and long-lasting disability. Gastrodia elata blume (GEB) is a Chinese herb that is widely used to treat convulsive disorders, such as epilepsy, and p-hydroxybenzyl alcohol (HBA) is the active ingredient in GEB. The present study was conducted to evaluate the effects of GEB and HBA on the brain damage and transcriptional levels of Protein disulfide isomerase (PDI) and 1-Cys peroxiredoxin (1-Cys Prx) genes known to play a role in antioxidant systems after transient focal ischemia in the rat brain. Focal ischemia was induced in rats by middle cerebral artery occlusion (MCAO). All animals underwent ischemia for 1 h, followed by 24 h of reperfusion. Coronal brain slices were stained with 2,3,5-triphenyltetrazolium chloride or total RNA was extracted for the analysis of gene expression. Histopathologic analysis revealed a significant (p<0.05) decrease in infarct size in the ipsilateral brain with GEB extracts or HBA. Moreover, the levels of PDI and 1-Cys Prx transcription were significantly increased in the GEB extract- or HBA-treated group compared with the untreated group (p<0.05). This study therefore indicated that GEB and HBA provide neuroprotection by preventing brain damage through the increased expression of genes encoding antioxidant proteins after transient focal cerebral ischemia and may be effective as neuroprotective agents at the cellular and molecular levels in the brain.

Effects of Chromium (VI) Exposure on the Placental Function and Reproduction in Rats.

OBJECTIVE: 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 transcriptionpolymerase 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. CONCLUSIONS: Chromium (VI) disrupts the ordered functions of the placenta, which leads to reproductive disorders in rats.