• Journal of The Korean Society of Clinical Toxicology
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• v.18 no.1
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• pp.26-33
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• 2020

Purpose: Agent Orange (AO) is a herbicide and defoliant used by the United States and its military allies during the Vietnam War. Pneumonia is a common cause of death among Vietnam veterans in our hospital. There have been no previous studies researching any association between AO exposure and the prognosis for pneumonia. The primary objective of this study was to investigate associations between AO exposure and 30-day mortality due to pneumonia. The secondary objective was to examine the clinical factors associated with therapeutic outcomes in veterans with pneumonia, and to assess the prevalence of combined diseases in AO-exposed veterans. Methods: This study retrospectively included veteran patients diagnosed with pneumonia in the emergency department and hospitalized between February 2014 and March 2018. The enrolled patients were grouped according to their defoliant exposure history, and the clinical information of defoliant-exposed and non-defoliant-exposed groups were compared. Patients were divided according to 30-day mortality, and significant factors influencing mortality were evaluated by using univariate analysis and multivariate analysis. The final multivariate model revealed the effect of AO exposure on therapeutic outcomes of pneumonia. Results: A total of 1006 patients were analyzed. Of these, 276 patients had a history of AO exposure, whereas 730 patients had not been exposed. Factors positively associated with 30-day mortality were malignancy, respiratory rate, blood urea nitrogen, and albumin which was negatively associated with mortality. Conclusion: Exposure to defoliant is not associated with 30-day mortality in patients with pneumonia. However, veterans with defoliant exposure are associated with a high prevalence of diabetes mellitus, hypertension, cerebrovascular accident, malignancy, and chronic kidney disease.

• Clinical and Experimental Pediatrics
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• v.64 no.7
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• pp.341-346
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• 2021

Background: The results differ among published studies regarding exposure to meconium and the risk of developing autism spectrum disorders (ASDs). Purpose: The present study pooled all of the epidemiologic studies retrieved from broader databases on the association between meconium exposure and risk of developing ASD in children. Methods: The Web of Science, PubMed, Scopus, and Google Scholar databases were searched without language restrictions for articles published between their inception to February 20, 2020, using relevant keywords. The pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated as random-effect estimates of the associations among studies. A subgroup analysis was conducted to explore any potential sources of heterogeneity among studies. Results: The pooled estimate of OR reported a weakly significant association between meconium exposure and ASD development in children (OR, 1.13; 95% CI, 1.03-1.24). There was low heterogeneity among the articles reporting risk for ASD among children (I²=19.3%; P=0.259). The results of subgroup analysis based on meconium exposure showed a significant association between a meconium-stained neonate and ASD development (OR, 1.18; 95% CI, 1.11-1.24). Couclusion: Meconium exposure was weakly associated with an increased risk of ASD. However, more evidence based on large prospective cohort studies is required to provide conclusive evidence about whether meconium exposure is associated with an increased risk of ASD development.

• Journal of radiological science and technology
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• v.21 no.2
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• pp.26-30
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• 1998

We tried to study in order to furnish the data for medical exposure dose and scattered ray in radiography. As the tables(from 1 to 3) show, we can presume, by means of a concrete numerical value, the amount of results affected by patient radiation exposure dose and somatic effect in radiography. However, there are many difficulties in the difference of exposure factor in each hospital, the accuracy of measuring by tracebility, shortage of exposure dose data especially in the area of children, and portable radiography, etc. In the radiation examination, it is considered if the gained benefit to the patient due to radiation is more than the risk of radiation, then the medical exposure is thought to be justified. Therefore, the radiotechnologists should continually make an effort to develop and study new techniques so as to reduce patient exposure dose.

• Safety and Health at Work
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• v.12 no.3
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• pp.396-402
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• 2021

Background: Styrene is one of the aromatic compounds used in acetonitrile-butadiene-styrene (ABS) producing petrochemicals, which has an impact on health of workers. Therefore, this study aimed to investigate the health risks of styrene emitted from the petrochemical industry in Iran. Methods: Air samples were collected based on NIOSH 1501 method. The samples were analyzed by the Varian-cp3800 gas chromatograph. Finally, risk levels of styrene's health effects on employees were assessed by the quantitative method of the U.S. Environmental Protection Agency (U.S. EPA) and the semiquantitative way by the Singapore Occupational Safety and Health Association. Results: Based on the results, the employees had the highest average exposure to styrene vapors (4.06 × 10^-1mg.(kg - day)^-1) in the polybutadiene latex (PBL) unit. Therefore, the most top predictors of cancer and non-cancer risk were 2.3×10^-4 and 7.26 × 10^-1, respectively. Given that the lowest average exposure (1.5 × 10^-2mg.(kg - day)^-1) was in the dryer unit, the prediction showed a moderate risk of cancer (0.8 × 10^-6) and non-cancer (2.3 × 10^-3) for the employees. The EPA method also predicted that there would be a definite cancer risk in 16% and a probable risk in 76% of exposures. However, according to the semiquantitative approach, the rate of risk was at the "low" level for all staff. The results showed that there was a significant difference (p < 0.05) between the units in exposure and health risk of styrene (p < 0.05). Conclusion: Given the high risk of styrene's health effects, appropriate control measures are required to reduce the exposure level.

• Journal of Photoscience
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• v.9 no.2
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• pp.430-432
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• 2002

The changes in expression of copper-zinc superoxide dismutase (CuZn-SOD), manganese superoxide dismutase (Mn-SOD) and glutathione peroxidase (GPX) in light-damaged rat retinas were examined. Sprague-Dawley rats (male, 6-weeks-old) were maintained on a cyclic photoperiod (12 hours light and 12 hours darkness) for 2 weeks. The illumination intensity during the light period was 80 lux. To induce light damage to the retina, a high-intensity illumination (3000-lux) was applied to the animals for 24 hours. After light exposure, the animals were returned to cyclic lighting. Eyes were enucleated 12 and 24 hours after light exposure started or 1,3, and 7 days after light exposure ended. Eyes were fixed and embedded in paraffin wax. Tissues were cut into 4${\mu}{\textrm}{m}$-thick sections. Sections were immunostained using antibody against CuZn-SOD, Mn-SOD, GPX and 8-hydroxy-deoxyguanocine (8-OHdG) as oxidative stress marker. 8-OHdG was observed in the outer nuclear layer (ONL) and retinal pigment epithelium (RPE) during light exposure. In light-damaged retinas CuZn-SOD labeling was up regulated in the ONL and RPE. Mn-SOD labeling was up regulated in rod inner segments (RIS) during light exposure and that in the RPE was up regulated after exposure. GPX labeling was observed in rod outer segments (ROS) during light exposure. GPX labeling was also observed in the RPE during and after light exposure. All three enzymes were observed in the outer retina, which suffered light damage, but occurred in defferent layers except within the RPE, in which case all three were expressed. These enzymes may play complementary roles as protective factors in light-damaged retinas.

• Molecular & Cellular Toxicology
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• v.5 no.2
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• pp.165-171
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• 2009

Biomarkers indicating past exposure to radiation have not yet been entirely satisfactory. In this study, we validated several genes reported as radiation response genes, as biomarkers to detect past exposure to radiation in occupationally exposed workers, especially workers in the medical field. A total of 54 radiation workers in hospital were investigated for radiation exposure dose. Their average radiation dose of recent one year was 1.09 mSv ($\pm$1.63) with a 10.63 mSv ($\pm$12.91) cumulative dose. The results of the multiple regression analysis for the various variables indicate that the Hsc70 (P=0.0292) and ORAL (P=0.0045) may be candidate biomarkers for the recent 1 year radiation exposure in radiation workers, whereas AEN (P=0.0334) and PGAMI (P=0.0003) might be for cumulative exposure.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.10
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• pp.4251-4256
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• 2015

Background: Exposure to cigarette may affect human health and increase risk of a wide range of diseases including pulmonary diseases, such as chronic obstructive pulmonary disease (COPD), asthma, lung fibrosis and lung cancer. However, the molecular mechanisms of pathogenesis induced by cigarettes still remain obscure even with extensive studies. With systemic view, we attempted to identify the specific gene modules that might relate to injury caused by cigarette smoke and identify hub genes for potential therapeutic targets or biomarkers from specific gene modules. Materials and Methods: The dataset GSE18344 was downloaded from the Gene Expression Omnibus (GEO) and divided into mouse cigarette smoke exposure and control groups. Subsequently, weighted gene co-expression network analysis (WGCNA) was used to construct a gene co-expression network for each group and detected specific gene modules of cigarette smoke exposure by comparison. Results: A total of ten specific gene modules were identified only in the cigarette smoke exposure group but not in the control group. Seven hub genes were identified as well, including Fip1l1, Anp32a, Acsl4, Evl, Sdc1, Arap3 and Cd52. Conclusions: Specific gene modules may provide better understanding of molecular mechanisms, and hub genes are potential candidates of therapeutic targets that may possible improve development of novel treatment approaches.

• Journal of Yeungnam Medical Science
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• v.39 no.4
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• pp.309-313
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• 2022

Background: Because premed students do not take courses related to medicine during their first 2 years, they cannot establish their identity as students at medical schools, making it difficult for them to set goals as future doctors. We conducted an early clinical and basic laboratory exposure program for premed students and studied the effects of the program and student satisfaction levels. Methods: We performed an early clinical and basic laboratory exposure program for premed students for 2 days and evaluated the effects of the program and student satisfaction with it. The program consisted of two types: type 1, where two to four students formed a group, which was assigned to a particular department to participate and make observations during ward rounds, outpatient clinics, examinations, procedures, and surgeries (in the case of basic laboratory work, the students partook in experimental observations); and type 2, where one student followed a medical school professor to observe the professor's day. After the program ended, an online survey was conducted to investigate the effects on students, their thoughts, and satisfaction levels. Results: In total, 114 students (91.2%) responded to the survey. Approximately 94% of them were satisfied with the program. They found that the program would be useful for deciding on future career paths, gaining knowledge about a department of interest, studying for a medical program after premedical studies, and befriending residents and professors in certain departments. Conclusion: Early clinical and basic laboratory exposure programs are recommended for premedical students.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.259-279
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• 2009

Radioiodine ablation therapy has been considered to be a standard treatment for patient with differentiated thyroid cancer after total thyroidectomy. Patients may need to be hospitalized to reduce radiation exposure of other people and relatives from radioactive patients receiving radioiodine therapy. Medical staffs, nursing staffs and technologists sometimes hesitate to contact patients in radioiodine therapy ward. The purpose of this paper is to introduce radiation dosimetry, estimate radiation dose from patients and emphasize the safety of radiation exposure from patients treated with high dose radioiodine in therapy ward. The major component of radiation dose from patient is external exposure. However external radiation dose from these patients treated with typical therapeutic dose of 4 to 8 GBq have a very low risk of cancer induction compared with other various risks occurring in daily life. The typical annual radiation dose without shielding received by patient is estimated to be 5 to 10 mSv, which is comparable with 100 to 200 times effective dose received by chest PA examination. Therefore, when we should keep in mind the general principle of radiation protection, the risks of radiation exposure from patients are low and the medical personnel are considered to be safe from radiation exposure.

• Progress in Medical Physics
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• v.27 no.3
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• pp.146-155
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• 2016

As the probability of exposure to radiation increases due to an increase in the use of radioisotopes and radiation generators, the importance of a radiation safety management field is being highlighted. We intend to help radiation workers with exposure management by identifying the degree of radiation exposure and contamination to determine an efficient method of radiation safety management. The personal exposure doses of the radiation workers at the Korea Institute of Radiological & Medical Sciences measured every quarter during a five-year period from Jan. 1, 2011 till Dec. 31, 2015 were analyzed using a TLD (thermoluminescence dosimeter). The spatial dose rates of radiation-controlled areas were measured using a portable radioscope, and the level of surface contamination was measured at weekly intervals using a piece of smear paper and a low background alpha/beta counter. Though the averages of the depth doses and the surface doses in 2012 increased from those in 2011 by about 14%, the averages were shown to have decreased every year after that. The exposure dose of 27 mSv in 2012 increased from that in 2011 in radiopharmaceutical laboratories and, in the case of the spatial dose rate, the rate of decrease in 2012 was shown to be similar to the annual trend of the whole institute. In the case of the surface contamination level, as the remaining radiation-controlled area with the exception of the I-131 treatment ward showed a low value less than $1.0kBq/m^2$, the annual trend of the I-131 treatment ward was shown to be similar to that of the entire institute. In conclusion, continuous attention should be paid to dose monitoring of the radiation-controlled areas where unsealed sources are handled and the workers therein.