• Toxicological Research
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• 제33권4호
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• pp.333-342
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• 2017

Ethyl formate, a volatile solvent, has insecticidal and fungicidal properties and is suggested as a potential fumigant for stored crop and fruit. Its primary contact route is through the respiratory tract; however, reliable repeated toxicological studies focusing on the inhalation route have not been published to date. Therefore, the present study was conducted to investigate the safety of a 90-day repeated inhalation exposure in rats. Forty male and 40 female rats were exposed to ethyl formate vapor via inhalation at concentrations of 0, 66, 330, and 1,320 ppm for 6 hr/day, 5 days a week for 13 weeks. Clinical signs, body weights, food consumption, urinalysis, hematologic parameters, serum chemistry measurements, organ weights, necropsy, and histopathological findings were compared between the control and ethyl formate-exposed groups. Locomotor activity decreased during exposure and recovered afterward in male and female rats exposed to 1,320 ppm ethyl formate. Body weight and food consumption continuously decreased in both sexes exposed to 1,320 ppm ethyl formate from week 1 or 3 compared with the control values. The increases in adrenal weight and decreases in thymus weight were noted in both sexes exposed to ethyl formate at 1,320 ppm. Degeneration, squamous metaplasia of olfactory epithelium in the nasopharyngeal tissue, or both were noted in the male and female rats at 1,320 ppm and female rats at 330 ppm ethyl formate. Taken together, our results indicate that ethyl formate-induced changes were not observed in male and female rats at 330 and 66 ppm, respectively. This indicates that exposure to ethyl formate at concentrations below 66 ppm for 90 days is relatively safe in rats. This is the first report of a full-scale repeated inhalation toxicity assessment in rats and could contribute to controlling occupational environmental hazards related to ethyl formate.

• Tuberculosis and Respiratory Diseases
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• 제47권4호
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• pp.533-537
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• 1999

저자들은 수년동안 반복적으로 유미흉이 재발하였던 31세 여자환자에서 환자의 연령, 임상 양상 등을 고려하여 볼 때 LAM이 의심되었으나, 흉부전산화단층 촬영상 흉막비후와 흉막하 소엽간중격의 비대 소견을 보이고, 낭성병변은 보이지 않으며, 조직검사상 폐실질의 림프혈관들의 확장성 변화를 동반한 증식을 관찰하였으나 평활근의 증식은 동반되지 않았으며 면역조직화학 염색 검사상 HMB-45와 에스트로젠수용체검사에서 음성을 보여 폐림프관종증으로 진단된 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

• 의학교육논단
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• 제18권2호
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• pp.99-105
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• 2016

The purpose of this study was to inquire into the knowledge of medical students on the Middle East respiratory syndrome (MERS) and evaluate whether infection prevention education impacts students' level of knowledge and individual hygiene practices. This study also investigated the route by which medical students obtain disease-related information. The study involved a survey conducted in August of 2015 at two medical schools in Busan. In the first year to fourth year, a total of 345 students are enrolled (111 students in A school and 234 students in B school). Before the study was carried out, university A performed infection prevention education related to MERS, but B did not. We used self-developed questionnaires to survey the demographic characteristics, routes of acquisition of MERS information, degree of knowledge of MERS, educational satisfaction, and personal hygiene practices before and after education. Knowledge level differences according to gender and year in school were not statistically significant. Students obtained their information about MERS from various news media sources and the Internet, and through social network sites. Students practiced sanitary control behaviors in an average of 2.2 manners (standard deviation=0.95). The level of knowledge of MERS revealed a positive correlation with the frequency and total numbers of personal hygiene practices. This finding suggests that the infection prevention education program played a role in knowledge acquisition and personal hygiene practices for the medical students. In order to provide accurate and reliable knowledge of disease and preventive health behavior to medical students, continuous and well-planned education programs are necessary.

• 한국환경보건학회지
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• 제47권6호
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• pp.513-520
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• 2021

Background: Benzalkonium chloride (BKC) has been extensively used as a preservative in industrial products and in hygiene, medical, and cosmetic applications. Humidifier disinfectant (HD) products containing BKC have been used in South Korea. Objectives: This study was aimed to review types of products containing BKC, to summarize the regulations in the US, EU, Japan, and South Korea, and to review the health effects associated with the use of HD. Methods: We reviewed and summarized documents which were searched through PubMed and Google Scholar with the key words: BKC and asthma/contact dermatitis, humidifier disinfectant-associated lung injury (HDLI), and more. Results: Regulations in most countries including South Korea do not allow its use as disinfectants in spray-type of products for medicine, cosmetics, and household products. Two types of HD containing BKC (800~1,270 ppm) were marketed in South Korea from 1996~2003. Health effects reported from people who used products containing BKC were allergic contact dermatitis, erythema, and respiratory disease, including asthma. Two people who responded as HD users containing BKC only were confirmed to have developed asthma. HD-associated lung injury (HDLI) was reported by consumers who used both HD containing polyhexamethylene guanidine (PHMG) and HD containing BKC. Conclusions: In conclusion, the use of BKC as a biocide has to be controlled considering the route and pattern of exposure. Products containing BKC as preservatives were reviewed with exposure routes and sites in the human body such as skin, eyes, and the respiratory tract. HD containing BKC was clinically evaluated to be associated with asthma.

• Biomolecules & Therapeutics
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• 제5권1호
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• pp.12-22
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• 1997

Intravenous and oral acute toxicity tests in ICR mice and SD rats and percutaneous acute toxicity tests in SD rats and NZW rabbits were conducted to evaluate the toxicity of DA-5018 and DA-5018 cream, respectively Clinical signs observed in mice and rats after the administration of DA-5018 were similar regardless of administration route. The observed clinical signs were jumping, wild running, lacrimation, ataxia, reddening of extremities and ears, ventral or lateral recumbency, respiratory distress, cyanosis, convulsion and death. Pulmonary enlargement and hemorrhage were observed in the animals died immediately after the dosing of DA-5018. At terminal necropsy, pulmonary enlargement and hemorrhage, corneal opacity and focal scabbing and depilation around nose were seen. LD$_{50}$ Values of DA-5018 are 11.5 mg/kg (mice, male), 12.6 mg/kg (mice, female), 88.3 mg/kg (rat, male) and 73.2 mg/kg (rat, female) in oral toxicity tests and 11.0 mg/kg (mice, male), 18.7 mg/kg (mice, female), 0.12 mg/kg (rat, male) and 0.32 mg/kg (rat, female) in i.v. toxicity tests. In the percutaneous acute toxicity tests of DA-5018 cream, no deaths occured in all the tested groups during 14-day observation period. There were also no abnormalities in the general conditions, body weight changes and on necropsy findings in all groups. LD$_{50}$ values of 0.1 ~0.9% DA-5018 creams in male and female rats and rabbits are >2000 mg/kg./kg.

• 한국토양동물학회지
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• 제11권1_2호
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• pp.7-12
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• 2006

Asthma and allergic rhinitis due to outdoor spider mites are major health problems worldwide. The sensitization route to spider mites has not yet been well elucidated. We examined the microstructure of faecal pellets and silk of the two-spotted spider mite, Tetranychus urticae, using a field emission scanning electron microscope. Black and white pellets of the two-spotted spider mites faeces contain a large amount of plant pigment waste products. Black faecal pellets are strawberry-shaped. White faecal pellets are silken threads. These pellets are likely to be the source of allergens of relevant mites because desiccated faeces particles probably disintegrate and become incorporated into dust particles more readily than whole bodies or encased internal organs. We conclude that the importance of spider mites in respiratory allergy needs emphasis.

• Safety and Health at Work
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• 제11권3호
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• pp.372-377
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• 2020

Infection risks of handling specimens associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by public health laboratory services teams were assessed to scrutinize the potential hazards arising from the work procedures. Through risk assessments of all work sequences, laboratory equipment, and workplace environments, no aerosol-generating procedures could be identified except the procedures (mixing and transfer steps) inside biological safety cabinets. Appropriate personal protective equipment (PPE) such as surgical masks, protective gowns, face shields/safety goggles, and disposable gloves, together with pertinent safety training, was provided for laboratory work. Proper disinfection and good hand hygiene practices could minimize the probability of SARS-CoV-2 infection at work. All residual risk levels of the potential hazards identified were within the acceptable level. Contamination by gloved hands was considered as a major exposure route for SARS-CoV-2 when compared with eye protection equipment. Competence in proper donning and doffing of PPE accompanied by hand washing techniques was of utmost importance for infection control.

• Advances in pediatric surgery
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• 제3권2호
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• pp.152-159
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• 1997

Transhiatal gastric transposition was performed in two case of long gap esophageal atresia without tracheoesophageal fistula. The patients were a 12 months old female and an 18 months old male. Stamm type gastrostomies were performed at other hospitals in both cases. The stomach was mobilized preserving the right gastric artery, the right gastroepiploic artery and spleen. A portion of the proximal and the distal esophageal segment were excised by transcervical and transhiatal route, respectively. The mobilized stomach was pulled up to the neck through the esophageal hiatus and posterior mediastinum. The esophagogastrostomy, the only one anastomosis of this procedure, was performed in the neck. There was no clinical evidence of anastomotic leakage, stricture, regurgitation, difficulty of gastric emptying, hoarseness or respiratory problem. Transhiatal gastric transposition seems to be a safe and easy alternative surgical procedure for esophageal replacement in long gap esophageal atresia.

• 한국환경보건학회지
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• 제40권4호
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• pp.265-278
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• 2014

Microbes such as bacteria, fungi, archaea, protists, and viruses are ubiquitous and people are exposed to them continuously. Endotoxin is a component of the outer membrane of Gram-negative bacteria and a potent proinflammaotry substance. When a person is exposed to environmental endotoxin, an innate immune response is initiated upon the initial recognition and this response produces various inflammatory mediators and recruits inflammatory cells to the exposed tissues. A purified chemical form of endotoxin is called lipopolysaccharide (LPS), and the lipid A portion of the molecule is a biologically active moiety. Exposure to endotoxin may result in various complex health effects depending on time, route, and dose of exposure, as well as host susceptibility. Gene-environment interactions play important roles in health effects of endotoxin exposure, e.g. development or aggravation of asthma. To accurately assess exposure to endotoxin in environmental or epidemiologic studies, methods of sampling, extraction, and analysis must be carefully selected since the selected methods may substantially affect analytical results and there is no internationally-agreed standard method to date. The lack of a standardized method hampers the establishment of exposure-response relationships. While an internationally-agreed health-based exposure limit does not exist, the Dutch Expert Committee on Occupational Safety recently recommended $90EU/m^3$ as a health-based occupational exposure limit. The current article reviews various scientific issues on how we measure environmental endotoxin and the health effects of endotoxin exposure.

• 한국임상약학회지
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• 제15권2호
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• pp.94-99
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• 2005

The aim of this study was to evaluate the safety and efficacy of treatment of mesoglycan. This study was conducted between September 2003 and May 2004. A total of 292 patients with vascular disorders including cerebral infarction were enrolled. The patients were administered with 50-100mg of mesoglycan by an oral route everyday for eight weeks. Subjective physicians' assessments of efficacy had ratings of 'improvement', 'invariability', 'exacerbation' and 'not being able to assess'. An improvement was observed in 241 patients out of 274; 18 patients were rules out. The efficacy rate was influenced statistically significantly by the duration of therapy (p=0.0392) and daily mean drug dose (p<0.0001). The adverse events were reported in 8 patients (9 cases) out of 292 patients: skin/appendages disorders (0.7%), liver/biliary system disorders (0.7%), cardiovascular system disorders (0.7%), neurologic disorders (0.3%). respiratory disorders (0.3%) and gastrointestinal system disorders (0.3%). There showed no serious adverse events. These results indicate that mesoglycan was well tolerated and effective for the prevention of vascular disorders.