• 대한치과의사협회지
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• 제12권5호
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• pp.313-316
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• 1974

The experimental female rats were ovariectomized and after 14day, they were injected intramuscullarly with estrogen of single dose, 2/100gm body weight. After hormone injection, the animals were sacrificed by ether inhalation, the salivary glands were removed for microscopic examination and the histochemical preparations were observed. The results were as followed; In the submaxillary gland of ovariectomized rats, the acinar cells have lesser PAS reactivity than control group, and-SH group reaction were slight. In the estrogen injected-ovariectomized rats, aciner cells and striated duct cells have high reactivities for PAS, and-SS and SH group reaction were more increased than control group.

• 방사선산업학회지
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• 제18권2호
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• pp.141-145
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• 2024

In Publication No. 66 of the International Commission on Radiological Protection, an activity median aerodynamic diameter (AMAD) of 5 ㎛ is considered in internal exposure dose assessment owing to inhalation of radionuclides in a workplace. However, analysis of aerosols generated during dismantling experiments, such as in the oxy-cutting of a reactor vessel conducted in Korea, revealed that the radioactive aerosols have AMAD ranging from 0.024 to 0.064 ㎛. Such extremely fine aerosols can induce internal exposure if inhaled. In particular, alpha radionuclides in aerosols can lead to significantly higher levels of radiation exposure than beta and gamma radionuclides, thus highlighting the need to establish appropriate internal exposure radiation protection programs and monitoring systems that specifically address alpha radionuclides when decommissioning nuclear power plants in Korea.

• Korean Journal of Acupuncture
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• 제34권4호
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• pp.241-250
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• 2017

Objectives : This study was performed to examine the toxicity of Aconitum ciliare Decaisne pharmacopuncture(ADP). Methods : The toxicity was evaluated for lethal dose for 50 percent kill(LD50), single dose and repeated dose for 4 weeks. Toxic symptoms, weight measurement, hematological test, blood biochemical test, visual examination and weight measurement of major organs and histopathological test were observed for 4 weeks. Dose of 300, 600, 1,200, 2,400, 3,600, 4,800, 6,000, 7,200 mg/kg in the LD50 experiment, 300, 600, 1,200 mg/kg/day in the single experiment, 150, 300, 600 mg/kg/day in 4 weeks experiments were injected into BALB/c mice. The ADP was injected into ST36 of the right leg. Normal saline solution of same volume was used for control group. In 24 hours after the last treatment, blood samples were taken after anesthesia by inhalation of ethyl ether. After that, the BALB/c mice were euthanized. Their heart, lungs, kidneys, liver and reproductive organs were removed and weighed. Histopathological evaluation was also performed. Results : ADP's LD50 was measured at 6,000 mg/kg. In both single and repeated dose toxicity test, no BALB/c mouse died during the experiments. ADP treatment for 4 weeks did not show any significant changes in toxic symptoms, weight measurement, hematological test, blood biochemical test, visual examination and weight measurement of major organs and histopathological test. Conclusions : As a result, ADP's LD50 was 6,000 mg/kg and repeated dose at a concentration of 600 mg/kg or less is considered to be not harmful for clinical treatment.

• 한국식품위생안전성학회:학술대회논문집
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• 한국식품위생안전성학회 2002년도 춘계학술발표대회 및 심포지움
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• pp.216-216
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• 2002

Generally, tobacco smoking has noxious effects such as DNA damage, lung cancer induction, coronary artery disease. Nowadays, as concerns on health and longevity increases, a huge variety of products that aim to assist to quit smoking or reduce addictive symptoms such as nicotine patches are developed and manufactured with safely evaluation, but the safety of the most recent products of interest which do not contain tobacco and nicotine, and shape cigarettes is not evaluated and guaranteed relatively. In this study, we used H-menthol(nicotine free-tobacco fine) which are widely consumed through the world to evaluate the single and repeated dose inhalation toxicity and genotoxicity of H menthol (Nicotine free-tobacco free) herbal cigarettes provided by Cigastop Ltd. in ICR mice.

• Journal of Radiation Protection and Research
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• 제27권2호
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• pp.121-126
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• 2002

본 연구는 지하수로부터 방출되어 가옥의 실내에 존재하는 라돈에 의한 체내축적량을 현실적으로 평가하는 방법을 보여준다. 먼저 지하수로부터 실내공기로 전달되는 과정을 모의하기 위해 2_구역모델을 개발하였다. 이 모델은 실내에서 발생하는 생활활동, 즉, 목욕, 세수, 세탁, 변기에서의 물사용에 의해 실내로 휘발, 이동하는 시간에 따를 라돈농도분포를 계산한다. 다음, 이 모델의 불확실성이 존재하는 입력인자들에 대해 불확실성분석을 수행하여 최종 실내라돈 농도분포를 결정하였다. 그리고 이러한 실내 라돈을 호흡하여 체내에 축적되는 양을 보다 정량적으로 모의하기 위해 PBPK 모델을 개발하였다. 불확실성이 포함된 라돈농도분포와 정량적인 체내축적모의를 위한 PBPK 모델의 결합으로 보다 현실적인 라돈의 체내축적량을 분석할 수 있다. 이러한 연구의 결과는 지하수로부터 발생하는 라돈에 의한 인체위해평가시 도움을 주리라고 판단된다.

• 한국가스학회지
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• 제18권4호
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• pp.1-7
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• 2014

화학물질로부터 근로자의 건강보호를 위해 사용량이 많으나 작업환경 및 유해성 평가 자료가 부족한 gasoline에 대해 유해성(hazards)을 조사하고 국내 취급실태 및 일부 취급 사업장의 작업환경 측정을 통해 위해성(risk assessment)을 평가하였다. 연구결과 gasoline은 생식독성 추정 및 생식세포 변이원성 물질인 1B, 그리고 IARC Group 2B, ACGIH A3 물질이었다. 작업환경 측정결과는 TLV-TWA 기준 $900mg/m^3$미만이었으며, 유해성 평가결과 발암 $RfC_{(Worker)}$는 $0.3mg/m^3$, 만성흡입독성 $RfC_{(Worker)}$는 $2.7mg/m^3$, 발달독성 $RfC_{(Worker)}$는 $2.7mg/m^3$이었다. 그리고 위험도 평가에서 발암성은 459, 만성흡입독성은 51, 발달독성은 51이었으며, 이를 토대로 한 gasoline의 위험도는 1을 초과하는 물질로 평가되었다.

• 대한치과마취과학회지
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• 제12권2호
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• pp.69-74
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• 2012

Background: The purpose of this study is to investigate the efficacy and safety of the sedation technique for implant surgery by combining the use of inhalation of nitrous oxide/oxygen with intravenous midazolam. Methods: Patients requiring surgery for the placement of dental implants were randomly allocated to two groups receiving intravenous midazolam or a combined technique using nitrous oxide/oxide and intravenous midazolam. Safety parameters, cooperation scores, anxiety scales, total amount of midazolam administered and recovery time were recorded and compared. Results: There were a statistically significant reduction in the amount of midazolam required to achieve optimal sedation (P<0.01), an overall significant reduction in recovery time (P<0.01), a significant reduction in anxiety scales (P<0.05), and a significant improvement in cooperation (P<0.05) and peripheral oxygen saturation (P<0.05) when a combined technique of inhalational $N_2O/O_2$ and midazolam was used. Conclusions: For implant surgery, this combining sedation technique could be safe and reliable, demonstrating reduction of total dose of midazolam and level of patient's anxiety and improvement in patient's recovery and cooperation.

• Asian Pacific Journal of Cancer Prevention
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• 제15권13호
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• pp.5253-5257
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• 2014

Formaldehyde (FA) is an economically important chemical, and has been found to cause various types of toxic damage to the body. Formaldehyde-induced toxic damage involves reactive oxygen species (ROS) that trigger subsequent toxic effects and inflammatory responses, which may increase risk of cancer. Therefore, in the present study, we aimed to investigate the possible toxic mechanism in bone marrow caused by formaldehyde. In accordance with the principle of randomization, the mice were divided into four groups of 6 mice per group. One group was exposed to ambient air and the other three groups were exposed to different concentrations of formaldehyde (20, 40, $80mg/m^3$) for 15 days in the respective inhalation chambers, 2h a day. At the end of the 15-day experimental period, all mice were killed. Bone marrow cells were obtained. Some of those were used for the determination of blood cell numbers, bone marrow karyote numbers, CFU-F, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content; others were used for the determination of mitochondrial membrane potential (MMP), cell cycle and Bcl-2, Bax, CytC protein expression. WBC and PLT numbers in median and high dose groups were obvious reduced, but there was no change on RBC numbers. There was also reduced numbers of bone marrow karyotes and CFU-F in the high dose group. SOD activity was decreased, but MDA content was increased. MMP and Bcl-2 expression were decreased with increasing formaldehyde concentration, while expression of Bax and Cyt C was increased. We also observed change in cell cycling, and found that there was S phase arrest in the high dose group. Our study suggested that a certain concentration of formaldehyde could have toxic effects on the hematopoietic system, with oxidative stress as a critical effect.

• Journal of Radiation Protection and Research
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• 제34권2호
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• pp.55-64
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• 2009

In a pressurized heavy water reactor (PHWR), radiation workers who have access to radiation controlled areas submit their urine samples to health physicists periodically; internal radiation exposure is evaluated by the monitoring of these urine samples. Internal radiation exposure at PHWRs accounts for approximately 20 $\sim$ 40% of total radiation exposure; most internal radiation exposure is attributed to tritium. Carbon-14 is not a dominant nuclide in the radiation exposure of workers, but it is one potential nuclide to be necessarily monitored. Carbon-14 is a low energy beta emitter and passes relatively easily into the body of workers by inhalation because its dominant chemical form is radioactive carbon dioxide ($^{14}CO_2$). Most inhaled carbon-14 is rapidly exhaled from the worker's body, but a small amount of carbon-14 remains inside the body and is excreted by urine. In this study, a method for dual analysis of tritium and carbon-14 in urine samples of workers at nuclear power plants is developed and a method for internal dose assessment using its excretion rate result is established. As a result of the developed dual analysis of tritium and carbon-14 in urine samples of radiation workers who entered the high radiation field area at a PHWR, it was found that internal exposure to carbon-14 is unlikely to occur. In addition, through the urine counting results of radiation workers who participated in the open process of steam generators, it was found that the likelihood of internal exposure to either tritium or carbon-14 is extremely low at pressurized water reactors (PWRs).

• Toxicological Research
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• 제33권4호
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• pp.305-313
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• 2017

Accumulating epidemiological evidence indicates that exposure to fine air pollution particles (APPs) is associated with a variety of adverse health effects. However, the exact physiochemical properties and biological toxicities of fine APPs are still not well characterized. We collected four types of fine particle (FP) (diesel exhaust particles [DEPs], natural organic combustion [NOC] ash, synthetic organic combustion [SOC] ash, and yellow sand dust [YSD]) and investigated their physicochemical properties and in vitro biological toxicity. DEPs were almost entirely composed of ultrafine particles (UFPs), while the NOC, SOC, and YSD particles were a mixture of UFPs and FPs. The main elements in the DEPs, NOC ash, SOC ash, and YSD were black carbon, silicon, black carbon, and silicon, respectively. DEPs exhibited dose-dependent mutagenicity even at a low dose in Salmonella typhimurium TA 98 and 100 strains in an Ames test for genotoxicity. However, NOC, SOC, and YSD particles did not show any mutagenicity at high doses. The neutral red uptake assay to test cell viability revealed that DEPs showed dose-dependent potent cytotoxicity even at a low concentration. The toxicity of DEPs was relatively higher than that of NOC, SOC, and YSD particles. Therefore, these results indicate that among the four FPs, DEPs showed the highest in vitro biological toxicity. Additional comprehensive research studies such as chemical analysis and in vivo acute and chronic inhalation toxicity tests are necessary to determine and clarify the effects of this air contaminant on human health.