• 농약과학회지
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• 제12권4호
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• pp.342-350
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• 2008

최근 내분비장애 추정물질의 분류를 위해 많은 시험법이 연구되고 있으며 미국 EPA와 OECD에서는 시험법을 설정하려고 노력하고 있다. 추후 기등록농약에 대한 자료요구 또는 신규 등록농약 적용 등록기준의 추가 등을 고려하여 내분비계장애 추정물질 관련 OECD와 EPA에서 권장하는 시험법을 확립하고자 본 연구를 수행하였다. 시험약제를 30일간 경구 투여하여 조사한 결과, metribuzin 투여 수컷에서 부고환, 전립선, 정낭의 중량이 증가하였고 갑상선에서는 유의한 중량변화가 나타나지 않았다. 암컷에서는 갑상선의 중량 감소가 나타난 반면에 생식장기 중량에는 유의적인 변화가 없었다. Metribuzin 투여수컷에서 testosterone이 100 mg/kg/day 처리수준에서 감소하였고 FT4가 50, 100 mg/kg 수준에서 증가하였다. 암컷에서는 T3가 50, 100 mg/kg/day 수준에서 증가하여 갑상선 호르몬에 영향이 나타나는 것을 볼 수 있었다. 시험세포를 이용한 시험결과, 시험약제를 1 nM에서 1,000 nM까지 처리하였을 때 음성대조군과 비교할 때 metribuzin은 106-122%의 영향을 나타내어 세포이용시험에서는 metribuzin이 갑상선 호르몬성 영향을 보인 것으로 나타났다. 항갑상선 호르몬성 영향 시험에서는 시험약제 100 nM과 T4의 혼합 처리시 metribuzin은 양성 대조군과 비교하여 감소하여 항갑상선 호르몬성 영향을 나타내었다. 본 시험을 통하여 OECD TG 407과 EDSTAC에서 권고하는 pubertal assay와 수의과학 검역원에서 제조한 HeLaTRE cell을 이용한 in vitro 시험이 갑상선 호르몬성 영향 검색 시험으로 활용될 가능성이 있는 것으로 사료되었다.

• 농약과학회지
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• 제12권3호
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• pp.207-214
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• 2008

내분비장애 추정물질의 분류를 위해 많은 시험법이 연구되고 있는데 추후 내분비장애 추정물질로 분류된 기등록 농약에 대한 자료요구 또는 신규 등록농약에 대한 등록기준의 추가 등을 고려하여 OECD와 EPA에서 권장하는 시험법을 확립하고자 본 연구를 수행하였다. 시험약제를 30일간 경구 투여하여 조사한 결과, alachlor 투여 수컷에서 25 mg/kg/day, 50 mg/kg/day에서 고환과 갑성선의 중량이 증가하였다. Alachlor 투여 암컷에서는 질의 중량이 25, 50 mg/kg/day에서 감소하였고 25 mg/kg/day에서 갑상선의 중량이 감소하였다. Alachlor 투여 암컷 25, 50 mg/kg/day에서 주요 갑상선 호르몬인 T4와 성호르몬 testosterone이 감소하였다. 따라서 pubertal assay 결과 alachlor는 갑상선 호르몬성 영향이 의심되었다. 시험세포를 이용한 시험 결과, 시험약제를 1 nM에서 1000 nM까지 처리하였을 때 음성대조군과 비교하여 alachlor는 100-134%의 갑상선 호르몬성 영향을 나타내었다. 따라서 세포를 이용한 시험에서는 alachlor에 의한 갑상선 호르몬성 영향이 나타나는 것으로 판단되었다. 항갑상선 호르몬성 영향 시험에서는 시험약제 100 nM과 T4의 혼합 처리시 alachlor는 항갑상선 호르몬성 영향은 나타나지 않았다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권2호
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• pp.737-740
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• 2015

Purpose: The study aim was to assess factors that impact on the outcome of radioiodine therapy in patients diagnosed with differentiated thyroid carcinoma (DTC). Materials and Methods: We performed a retrospective cohort study on 256 patients with DTC who underwent thyroidectomy and received radioiodine therapy during December 2003 to January 2012. All patients were followed up for at least 1 year. They were considered diseasefree by the criteria of the revised American Thyroid Association Management Guideline for Patients with Thyroid nodules and DTC (ATA guideline 2009). Results: On Cox univariate analysis, factors associated with disease-free status were age<45, stage I tumor, low risk group by histopathology, unifocal tumor involvement, stimulated serum Tg level at 1st dose of radioiodine therapy and no distant metastasis from 1st post-treatment WBS (post RxWBS). On multivariate analysis, stage I tumor and stimulated serum Tg level at 1st dose of radioiodine therapy < 30 ng/mL were the significant prognostic factors that increased disease-free rate by 1.73 times and 2.60 times, respectively (P-value <0.05). Conclusions: Factors affecting the outcome of radioiodine therapy in our study were age, stage, risk of recurrence by histopathology, unifocal tumor involvement and 1st postRxWBS findings. From these factors, stage I tumor and stimulated serum Tg level at 1st dose of radioiodine therapy were independent prognostic factors that substantial increase the disease-free rate.

• The Korean Journal of Pain
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• 제33권1호
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• pp.73-80
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• 2020

Background: The aim of this study was to evaluate radiation exposure to the eye and thyroid in pain physicians during the fluoroscopy-guided cervical epidural block (CEB). Methods: Two pain physicians (a fellow and a professor) who regularly performed C-arm fluoroscopy-guided CEBs were included. Seven dosimeters were used to measure radiation exposure, five of which were placed on the physician (forehead, inside and outside of the thyroid protector, and inside and outside of the lead apron) and two were used as controls. Patient age, sex, height, and weight were noted, as were radiation exposure time, absorbed radiation dose, and distance from the X-ray field center to the physician. Results: One hundred CEB procedures using C-arm fluoroscopy were performed on comparable patients. Only the distance from the X-ray field center to the physician was significantly different between the two physicians (fellow: 37.5 ± 2.1 cm, professor: 41.2 ± 3.6 cm, P = 0.03). The use of lead-based protection effectively decreased the absorbed radiation dose by up to 35%. Conclusions: Although there was no difference in radiation exposure between the professor and the fellow, there was a difference in the distance from the X-ray field during the CEBs. Further, radiation exposure can be minimized if proper protection (thyroid protector, leaded apron, and eyewear) is used, even if the distance between the X-ray beam and the pain physician is small. Damage from frequent, low-dose radiation exposure is not yet fully understood. Therefore, safety measures, including lead-based protection, should always be enforced.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.2050-2056
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• 2024

Handling of radioisotopes may cause external and internal contamination to occupational workers while using radiation for medical purposes. This research aims to monitor the internal hazard of occupational workers who handle ¹³¹I. Two methods are used: in vivo or direct method and in vitro or indirect method. The in vivo or direct method was performed by assessing thyroid intake with a thyroid uptake monitoring machine. The in vitro or indirect method was performed by assessing urine samples with the help of a gamma-ray spectroscopy practice using a High-Purity Germanium (HPGe) Detector. In this study, fifty-nine thyroid counts and fifty-nine urine samples were collected from seven occupational workers who were in charge of ¹³¹I at the National Institute of Nuclear Medicine and Allied Sciences (NINMAS), Dhaka. The result showed that the average annual effective dose of seven workforces from thyroid counts were 0.0208 mSv/y, 0.0180 mSv/y, 0.0135 mSv/y, 0.0169 m Sv/y, 0.0072 mSv/y, 0.0181 mSv/y, 0.0164 mSv/y and in urine samples 0.0832 mSv/y, 0.0770 mSv/y, 0.0732 mSv/y, 0.0693 mSv/y, 0.0715 mSv/y, 0.0662 mSv/y, 0.0708 mSv/y.The total annual effective dose (in vivo and in vitro method) was found among seven workers in average 0.1039 mSv/y, 0.0950 mSv/y, 0.0868 mSv/y, 0.0862 mSv/y, 0.0787 mSv/y, 0.0843 mSv/y, 0.0872 mSv/y. Following the rules of the International Commission on Radiological Protection (ICRP), the annual limit of effective dose for occupational exposure is 20 mSv per year and the finding values from this research work are lesser than this safety boundary.

• 동의생리병리학회지
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• 제26권5호
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• pp.714-723
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• 2012

The object of this study was to evaluate the effect of Bupleuri Radix, aqueous extracts of the root part of Bupleurum falcatum on the 6-n-propyl-2-thiouracil (PTU)-induced rat hypothyroidism. Aqueous extracts of Bupleuri Radix (BR; yield = 11.73%) were administered, once day for 42 days from 2 weeks before start of PTU treatment as an oral dose of 300 and 150 mg/kg (body weight), and hypothyroidism was induced by daily subcutaneous treatment of PTU 10 mg/kg for 28 days. The changes on the body weight, thyroid gland weights, serum thyroid hormone - thyroid stimulating hormone (TSH), triiodothyronine ($T_3$) and thyroxine ($T_4$), serum lipid profiles - total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL) and triglyceride, liver antioxidant defense system - lipid peroxidation, $H_2O_2$, superoxide dismutase (SOD) and catalase (CAT), serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were observed with histopathology of thyroid glands. Results were compared with $LevoT_4$ 0.5 mg/kg treated rats. As results of PTU treatment, marked decreases of body weights, triglyceride contents, liver CAT activities and changes of serum thyroid hormone levels were observed with increases of serum AST, HDL contents, liver $H_2O_2$ and SOD activities and thyroid gland weight. In addition, marked hyperplasia of follicular cells with decreases of follicular colloid contents and sizes were demonstrated at histopathological inspections. However, these PTU induced hypothyroidism were dose-dependently inhibited by treatment of BR extracts, and BR extracts effectively regulated the hypothyroidism related changes on the antioxidant defense system. The results obtained in this study suggest that BR extracts have favorable effects on the thyroid hormone productions with beneficial effects on the hypothyroidism mediated by the modulatory effects on the antioxidant defense system.

• 대한방사선기술학회지:방사선기술과학
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• 제46권5호
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• pp.401-408
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• 2023

Thyroid uptake measurements can be subject to measurement errors due to the scoping and positioning of the thyroid gland. To compensate for these limitations, the clinical utility of the thyroid simultaneous counting method as an alternative to thyroid uptake measurement was analyzed and evaluated experimentally through quantitative analysis of images acquired after thyroid scanning. Experimental data were obtained using a Gamma camera (GE infinia), a thyroid uptake system (KOROID 1), and a thyroid neck phantom. Based on the thyroid uptake rate of 1-5% according to the protocol of thyroid scan test (^99mTcO₄ - , 370 MBq) in normal results, ^99mTcO₄ - was set in the range of 3.7-18.5 MBq (Matrix: 256×256, Scan time: 1 min, collimator: pin hole, phantom-collimator distances: 7 cm). The acquired images were corrected for the attenuation of isotopes due to the set-up time and half-life by applying the Auto Region of interest (ROI) drawing system, and the significance of the experimental results was evaluated by Multiple linear regression analysis (SPSS, ver. 22, IBM). The thyroid uptake rate showed a significant correlation between the dose and the measured counts when using the thyroid uptake system equipment. Meanwhile, the quantitative analysis counts of phantom images using Gamma camera also showed a significant correlation. Thus confirmed that the correlation between these two experiments was statistically significant (P<0.05). The simultaneous counting protocol, which indirectly measures thyroid uptake from thyroid scans, is likely to be clinically relevant if complemented by additional studies with different variables in patients with thyroid disease.

• 대한방사선기술학회지:방사선기술과학
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• 제40권4호
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• pp.543-548
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• 2017

경추 사방향 검사에서 전후면과 후전면 자세에 따른 갑상선 표면선량을 평가하여 검사 방법의 유용성을 알아보고자 하였다. 선량 측정은 Rando phantom을 이용하여 갑상선의 위치인 경추 4~5번에 선량계를 부착 시켜 측정하였다. 연구 결과, 전후면 사방향 자세와 후전면 사방향 자세의 표면선량 값은 kVp 변화에 따라 각각 $595.08{\pm}215.01{\mu}Gy$, $64.21{\pm}33.49{\mu}Gy$이었으며, mAs 변화에 따라 각각 $445.20{\pm}230.90{\mu}Gy$, $44.51{\pm}22.77{\mu}Gy$로 나타났다. 후전면 사방향 자세는 전후면 사방향 자세에 비해 갑상선이 받는 표면선량을 약 90% 감소시킬 수 있었으며, 각각의 비교에서 통계적으로 유의한 차이를 보였다(p<0.001). 따라서 방사선 감수성이 민감한 갑상선이 조사야 내에 포함된 경추검사에서는 환자의 표면선량을 줄이는데 후전면 사방향 자세가 유용할 것으로 판단된다.

• 대한방사선기술학회지:방사선기술과학
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• 제47권3호
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• pp.205-211
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• 2024

Currently, with the development of technologies, X-ray examinations for medical examinations at hospital is increasing. This study was conducted to help reduce radiation exposure by measuring the exposure dose received by pediatric patients and the spatial dose of the X-ray room. Dosimeters were installed in the eyeball, thyroid gland, breast, gonads and 4 directions at a distance of 30 cm, 40 cm, 50 cm from the phantom. The dose was measured ten times each, before, and after the application of the bismuth shield under the examination conditions of the head, chest, and abdomen of pediatric patients. Under the condition of head examination, when a shielding was applied, the dose reduction rate was 68.58% for the eyeball, 72.88% for the thyroid, 84.2% for the breast, and 72.36% for the gonad. The chest examination showed reductions of 19.56% eyeball, 56.98% thyroid, 1.21% breast, and 0.68% gonad. The abdominal examination showed reduction rates of 2.6% eyeball, 10.67% thyroid, 19.85% breast, and 82.02% gonad. Spatial dose decreased by 62.25% at 30 cm, 61.16% at 40 cm, and 68.68% at 50 cm. When the bismuth shield was applied, there was a decrease in dose across all examinations, as well as a reduction in spatial dose. Continued research on the use of bismuth shields will help radiological technologists achieve their goal of dose reduction.

• Nuclear Medicine and Molecular Imaging
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• 제43권4호
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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.