• Communications for Statistical Applications and Methods
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• v.9 no.3
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• pp.693-701
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• 2002

When the lowest dose level compared with zero-dose control has significant difference in effect, it is referred as minimum effective dose (MED). In this paper, we discuss several nonparametric methods for finding MED using updated rank at each sequential test step in small sample size and suggest new nonparametric procedures based on placement. Monte Carlo Simulation is adapted to compare power and Familywise Error Rate(FWE) of the new procedures with those of discussed nonparametric tests for finding MED.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.2
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• pp.61-72
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• 2018

Objectives The purpose of this experiment is to evaluate 4 weeks DRF (Dose Rate Finding) and single oral dose toxicity of ChondroT in rats. Methods In 4-week DRF, male and female Sprague-Dawely rats were treated with ChondroT at oral dose of 0, 500, 1000, and 2000 mg/kg. clinical signs, body weight, food consumption, necropsy findings, organ weight, hematological and blood-chemical parameters, and histological findings were monitored for 4 weeks. Also, after single oral administration of ChondroT, mortality, clinical signs, body weight, and necropsy findings were minitored for 2 weeks. Results In 4-week DRF and single dose oral toxicity study of ChondroT in sprague-Dawley rats, ChondroT did not exhibit any toxicity under the study conditions employed. Conclusions The results suggested a no-observed adverse effects level (NOAEL) was over 2,000 mg/kg/day in SD rats after oral administration, this study could be used as basic study of the repeated dose 13-week oral toxicity study of ChondroT.

• Communications for Statistical Applications and Methods
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• v.19 no.1
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• pp.33-45
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• 2012

The primary interest of drug development studies is to estimate the smallest dose that shows a significant difference from the zero-dose control. The smallest dose is called the Minimum Effective dose(MED). In this paper, we suggest a nonparametric procedure to simultaneously find the MED of each group based on placements. The Monte Carlo simulation is adapted to estimate the power and the family-wise error rate(FWE) of the new procedures with those of discussed nonparametric tests to find MED.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.162-165
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• 2003

Uptake efficiencies of PCB 153 in fathead minnow through food chain of sediment-midge-fish were evaluated. Contaminated fish food, the midge Chironomus plumosus was prepared by exposing to sediments with PCB 153. We could harvest the midges with body PCB 153 levels of ∼ 1.0 mg/g and ∼ 10.0 mg/g, respectively, in 2 wk of exposure. PCB 153 level in fish fed with midge of 10.0 mg/g PCB 153 (high-dose group) reached its highest at 11.2 mg/g after 30 d of exposure. However, PCB level in fish fed with midge of 1.0 mg/g PCB 153 (low-dose group) kept increasing following first order rate kinetics until the end of exposure (38 d). When the fish food was changed to the uncontaminated ones, the fish body PCB levels were stabilized in ∼ 3 wk. The uptake efficiency in high-dose fish group was 37%, whereas low-dose group was 55%. Uptake efficiencies in fathead minnows were notably lower than that of pike (∼ 70%). This finding suggests that the uptake efficiency of this PCB congener may depend on the amount of the PCB in diet.

• Development and Reproduction
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• v.22 no.1
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• pp.85-94
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• 2018

Endocrine disruptors have been concerned in toxicology but now challenged as physiological point especially concerned with exposing dose and period. In this study the low-dose chronic administration of di(2-ethylhexyl) phthaltae (DEHP) during reproductive period was examined to evaluate the possible roles. Adult male and female CD-1 mice were exposed to DEHP with drinking water containing $133{\mu}g/L$ and $1,330{\mu}g/L$ DEHP in water according to OECD 433 guide line and sacrificed just after weaning. The weights of uterus and ovary were decreased by drinking of $1,330{\mu}g/L$ DEHP water. There was not adverse effects on either accumulated mating rate and mating rate depend on estrus stage, pregnancy duration, and sex ration at birth. However, the accumulated rate of successful delivery and litter size were significantly high at $1,330{\mu}g/L$ DEHP water. The number of epididymal sperm was significantly increased by drinking of $1,330{\mu}g/L$ DEHP water. In addition, the number of follicles (primary, secondary, tertiary) were more many than control at $1,330{\mu}g/L$ DEHP water drunk mother. Though further studies are needed to identify what are the mechanism of DEHP in folliculogenesis and spermatogenesis. From this study we firstly report the effect of low-dose chronic administration of DEHP with drinking could change the ovarian follicle population size and spermatogenesis rate. Put together, those finding is different from previous high-dose effects and suggest the physiological role of DEHP in gonads and uterus.

• Advances in environmental research
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• v.3 no.3
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• pp.231-251
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• 2014

The present study examines the phosphate adsorption potential and behavior of mixture of Ground Burnt Patties (GBP), a solid waste generated from cooking fuel used in earthen stoves and Red Soil (RS), a natural substance in fixed bed column mode operation. The characterization of adsorbent was done by Proton Induced X-ray Emission (PIXE), and Proton Induced ${\gamma}$-ray Emission (PIGE) methods. The FTIR spectroscopy of spent adsorbent reveals the presence of absorbance peak at $1127cm^{-1}$ which appears due to P = O stretching, thus confirming phosphate adsorption. The effects of bed height (10, 15 and 20 cm), flow rate (2.5, 5 and 7.5 mL/min) and initial phosphate concentration (5 and 15 mg/L) on breakthrough curves were explored. Both the breakthrough and exhaustion time increased with increase in bed depth, decrease in flow rate and influent concentration. Thomas model, Yoon-Nelson model and Modified Dose Response model were used to fit the column adsorption data using nonlinear regression analysis while Bed Depth Service Time model followed linear regression analysis under different experimental condition to evaluate model parameters that are useful in scale up of the process. The values of correlation coefficient ($R^2$) and the Sum of Square Error (SSE) revealed the Modified Dose Response model as the best fitted model to the experimental data. The adsorbent mixture responded effectively to the desorption and reusability experiment. The results of this finding advocated that mixture of GBP and RS can be used as a low cost, highly efficient adsorbent for phosphate removal from aqueous solution.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.57-66
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• 2003

Single and 28-day repeated dose toxicity studies of botulimnn toxin type A were carried out in ICR mice and Sprague-Dawley rats, respectively. In the single dose toxicity study, botulinwn toxin was injected intraperitoneally to male and female mice at a single dose of 40, 59, 89 133 and 200 ng/10 ml saline/kg. All animals died from 59 ng/kg group. Some clinical signs, such as decrease in locomotor activity, dyspnea, prone position and ptosis, were observed in most of both sexes from 59 ng/kg group, but no signs were seen in all animals at 40 ng/kg group. The results showed that the median lethal dose of botulinum toxin might be in the range of 40-59 ng/kg in both sexes. In the repeated dose toxicity study, the test material was administered intradermally for 28 days at doses of 0 (vehicle-treated control), 1.25, 2.5, 5.0 and $10.0ng/head/50{\mu}{\ell}$ saline in male and female rats. No test material-related changes were noted in survivals, clinical signs, food and water consumptions and gross finding in any group. Botulinum toxin treatment significantly decreased the body weight gain rate in male of 5.0 ng/head group and over and in female of 10.0 ng/head group compared to vehicle-treated control. One or more relative organ weights (i.e., spleen, thymus, liver and kidney) were increased significantly from 5.0 ng/head group compared to vehicle-treated control in both sexes. Serum biochemistry revealed increases in aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine phosphokinase, total protein and albumin in male, and increases in AST and ALT and decreases in $K^+$ and $Cl^-$ in female without dose-pendent manners. In the histopathological study, physical stimulation by needle caused slight inflammations of dennis. In addition, botulinum toxin treatment induced denervation of nerve cell and disuse of muscle, resulting in atrophy of skeletal muscle in both sexes from 2.5 ng/head group. When the antibodies to toxin were determined in all animals, a significant increase in serum antibodies was observed from 5.0 ng/head group. The results showed that the NOAEL of botulinum toxin might be 1.25 ng/head for 28-day repeated dose toxicity in rats.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.10
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• pp.45-50
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• 1971

For the purpose of finding out the effect of heat treatment on biological response and mutation rate, rice seeds were heat treated before and after gamma irradiation. 1. At a dose of 20 KR, pre-irradiation heat treatment showed reduced biological damage and increased mutation rate as compared with non-heat treatment. 2. Mutation frequency was increased in post-treatment of heat shock than in pre-irradiation heat treatment and non-heat treatment. 3. Pre-irradiation heat treatment at 6$0^{\circ}C$ for 30 minutes markedly reduced the biological damage and increased the mutation rate. 4. Mutation spectrum in heat treatment was different from non-treatment.

• Progress in Medical Physics
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• v.5 no.2
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• pp.57-68
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• 1994

Purpose : The purposes are to discuss the reason to measure dose distributions of circular small fields for stereotactic radiosurgery based on medical linear accelerator, finding of beam axis, and considering points on dosimetry using home-made small water phantom, and to report dosimetric results of 10MV X-ray of Clinac-18, like as TMR, OAR and field size factor required for treatment planning. Method and material : Dose-response linearity and dose-rate dependence of a p-type silicon (Si) diode, of which size and sensitivity are proper for small field dosimetry, are determined by means of measurement. Two water tanks being same in shape and size, with internal dimension, 30${\times}$30${\times}$30cm$^3$ were home-made with acrylic plates and connected by a hose. One of them a used as a water phantom and the other as a device to control depth of the Si detector in the phantom. Two orthogonal dose profiles at a specified depth were used to determine beam axis. TMR's of 4 circular cones, 10, 20, 30 and 40mm at 100cm SAD were measured, and OAR's of them were measured at 4 depths, d$\sub$max/, 6, 10, 15cm at 100cm SCD. Field size factor (FSF) defined by the ratio of D$\sub$max/ of a given cone at SAD to MU were also measured. Result : The dose-response linearity of the Si detector was almost perfect. Its sensitivity decreased with increasing dose rate but stable for high dose rate like as 100MU/min and higher even though dose out of field could be a little bit overestimated because of low dose rate. Method determining beam axis by two orthogonal profiles was simple and gave 0.05mm accuracy. Adjustment of depth of the detector in a water phantom by insertion and remove of some acryl pates under an auxiliary water tank was also simple and accurate. TMR, OAR and FSF measured by Si detector were sufficiently accurate for application to treatment planning of linac-based stereotactic radiosurgery. OAR in field was nearly independent of depth. Conclusion : The Si detector was appropriate for dosimetry of small circular fields for linac-based stereotactic radiosurgery. The beam axis could be determined by two orthogonal dose profiles. The adjustment of depth of the detector in water was possible by addition or removal of some acryl plates under the auxiliary water tank and simple. TMR, OAR and FSF were accurate enough to apply to stereotactic radiosurgery planning. OAR data at one depth are sufficient for radiosurgery planning.

• Journal of Yeungnam Medical Science
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• v.36 no.2
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• pp.115-123
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• 2019

Background: This study aimed to assess the in-field lymph node (LN) failure rate according to LN size and to investigate effect of LN size on the survival outcome of patients with locally advanced cervical carcinoma treated with concurrent chemoradiotherapy (CCRT). Methods: A total of 310 patients with locally advanced cervical carcinoma treated with CCRT were enrolled in retrospective study. LN status was evaluated by magnetic resonance imaging. All patients received conventional external beam irradiation and high-dose rate brachytherapy, and concurrent cisplatin-based chemotherapy. In-field LN failure rate according to LN size was analyzed. Results: The median follow-up period was 83 months (range, 3-201 months). In-field LN failure rate in patients with pelvic LN size more than 10 mm was significantly higher than that in patients with pelvic LN size less than 10 mm (p<0.001). A similar finding was observed in the infield para-aortic LN (PALN) failure rate (p=0.024). The pelvic and PALN size (${\geq}10mm$) was a significant prognostic factor of overall-survival (OS) and disease-free survival rate in univariate and multivariate analyses. The OS rate was significantly different between groups according to LN size (<10 mm vs. ${\geq}10mm$). Conclusion: A LN of less than 10 mm in size in an imaging study is controlled by CCRT. On the other hand, in LN of more than 10 mm in size, the in-field LN failure rate increase and the prognosis deteriorate. Therefore, a more aggressive treatment strategy is needed.