• Herbal Formula Science
• /
• v.28 no.2
• /
• pp.169-177
• /
• 2020

Objectives : This experiment was designed to assess the single oral toxicity of Ethanol Extract Inulae Flos (IF) ethanol extracts. IF is one of the important herbs to remove phlegmy which is the viscous turbid pathological product that can accumulate in the body, causing a variety of diseases. Nevertheless, there has been a lack of research on the pharmacology toxicity of IF. Methods : In this study, IF was orally administered to 5 weeks ICR mice as an oral dose of 2,000 or 3,000 or 5,000 mg/kg. The condition of the mice was observed for 14 days and their weights were measured every two days. Results : None of the mice died for 14 days. The abnormal clinical symptoms and anatomical signs of toxicity were not found in any treatment groups. The gain of net body weight was observed. There was also no significant difference in the organ weight. The serum biochemistry and hematological analysis showed a decrease in BUN, red blood cells, white blood cells and platelets although within the normal ranges. Conclusions : These results suggest that the 50% lethal dose of IF is more than 5,000 mg/kg. This could be thought that IF is a safe drug without acute toxicity and side effects. However, IF showed some weight loss and change in blood test, so it will need to be careful when using it for high doses.

• Imaging Science in Dentistry
• /
• v.48 no.2
• /
• pp.103-109
• /
• 2018

Purpose: To analyze cone-beam computed tomography (CBCT) use, indications, and exposure parameters in San $Jos{\acute{e}}$, Costa Rica. Materials and Methods: A cross-sectional study was performed. All CBCT examinations over a period of 6 months at 2 radiological centers in San $Jos{\acute{e}}$, Costa Rica were evaluated. The examinations were performed with Veraview EPOC X550 and Veraviewepocs 3D R100 equipment. The patients' age and sex, clinical indication for CBCT, region of interest (ROI), repeat examinations, specialty of the referring dentist, field-of-view (FOV), tube voltage (kV), tube current (mA), and radiation dose (${\mu}Gy$) were evaluated. Patients were classified by age as children (${\leq}12years$), adolescents(13-18 years), and adults(${\geq}19years$). Results: The mean age of the 526 patients was 49.4 years. The main indications were implant dentistry and dental trauma. The most frequent ROIs were posterior, while anterior ROIs were much less common. The highest percentage of repeat examinations was in children. Fifty-six percent of the referring dentists were specialists. The most commonly used FOV was small. The mean tube voltage and current were 79.8 kV and 7.4 mA for Veraview EPOC X550 and 89.9 kV and 6 mA for Veraviewepocs 3D R100, respectively. The mean doses for children, adolescents, and adults were $6.9{\mu}Gy$, $8.4{\mu}Gy$, and $7.8{\mu}Gy$, respectively. Conclusion: Although CBCT was most commonly used in adults for implant dentistry, most repeat examinations were in children, and the highest mean dose was in adolescents. Additional dose optimization efforts should be made by introducing low-dose protocols for children and adolescents.

• YAKHAK HOEJI
• /
• v.58 no.1
• /
• pp.62-70
• /
• 2014

A 28-day repeated-dose oral toxicity test was performed to determine the no-observed-effect level (NOEL) and establish an optimum dose of the highly toxic Aconiti Ciliare Tuber (ACT) used as a folk remedy. Repeated oral doses of 1,250, 2,500, and 5,000 mg/kg/day of the hot water extract of ACT were administered to five male and five female Sprague-Dawley rats in each group for 4 weeks. The indicators for toxicity included results of examination of common symptoms and changes in weight and feed intake, eye test, urinalysis, hematological and serum biochemical analyses, and post-mortem weight measurement of organs, and visual inspections. All animals survived at the end of the experiment; in addition, we observed no specific test substance-mediated symptoms. We observed no test substance-mediated changes in body weight and feed intake. We observed statistically significant changes in male OB and pH levels (p<0.05). Further, the biochemical test showed statistically significant changes in the IP value of male rats and $CL^-$valueoffemalerats (p<0.05). However, all changes were within historical data. The post-mortem examinations showed no test substance-mediated changes. Moreover, statistically significant changes under the test conditions were confirmed to have been caused by factors other than the test substance. Thus, the maximum NOEL of ACT extract in rats was estimated to be 5,000 mg/kg/day.

• Restorative Dentistry and Endodontics
• /
• v.29 no.3
• /
• pp.239-248
• /
• 2004

The purpose of this study was to investigate the influence of NK1 receptor antagonists on the pulpal blood flow (PBF) when applied iontophoretically through the dentinal cavity of the teeth in order to understand whether iontophoretically applied NK1 receptor antagonists can control the pulpal inflammation. Eleven cats were anesthetized with alpha-chloralose and urethane, and substance P (SP) was administered to the dental pulp through the catheterized lingual artery in doses that caused PBF change without the influence of systemic blood pressure. NK1 receptor antagonists were applied iontophoretically to the prepared dentinal cavity of ipsilateral canine teeth of the drug administration, and PBF was monitored. Data were analyzed statistically with paired t-test. PBF increase after iontophoretic application of the NK1 receptor antagonists followed by the intra-arterial administration of SP was significantly less than PBF increase after iontophoretic application of the 0.9% saline followed by the intra-arterial administration of SP as a control (p < 0.05). Iontophoretic application of the NK1 receptor antagonists (0.2~3.4 mM) following the intra-arterial administration of SP resulted in less increase of PBF than the iontophoretic application of the 0.9% saline following the intra-arterial administration of SP as a control (p < 0.05). Therefore. the results of the present study provide evidences that the iontophoretic application is an effective method to deliver drugs to the dental pulp. and that iontophoretically applied NK1 receptor antagonists block SP-induced vasodilation effectively. The above results show the possibility that the iontophoretical application of NK1 receptor antagonists can control the neurogenic inflammation in the dental pulp.

• Korean Journal of Clinical Laboratory Science
• /
• v.44 no.2
• /
• pp.59-65
• /
• 2012

Previous studies have shown that modified Je-Ho-Tang (MJHT) has anti-platelet effects. Je-Ho-Tang (JHT), a Korean court beverage, is a traditional Korean herbal medicine that has been used for the treatment of a disease attended by great thirst, and for prevention of illness in hot summers. We made MJHT from JHT by excluding honey. The present study was performed to determine the acute oral toxicity of crude extract of MJHT in male and female ICR mice. We investigated the in vivo single dose acute toxicity of MJHT hot-water extraction. This test was orally administered once by gavage to 20 mice of each sex received doses of 0 (control group), 1250, 2500 and 5000 mg/kg body weight. Mortalities, clinical findings, autopsy findings and body weight changes were monitored daily for 14 days following the administration. We observed survival rates, general toxicities, changes of body weight, and autopsy. No significant lethality was observed after single oral administration of MJHT at the different dosages. Autopsies on the animals revealed no gross abnormalities. Therefore, the LD50 value of MJHT for ICR mice was estimated more than 5000 mg/kg by the oral route. These results suggest that no toxic dose level of MJHT in mice is considered to be more than 5000 mg/kg. Consequently, it was concluded that MJHT have no effect on acute toxicity and side effect in ICR mice.

• Toxicological Research
• /
• v.35 no.4
• /
• pp.295-301
• /
• 2019

In this review, we describe the absorption rates (Caco-2 cell permeability) and hepatic/plasma pharmacokinetics of 53 diverse chemicals estimated by modeling virtual oral administration in rats. To ensure that a broad range of chemical structures is present among the selected substances, the properties described by 196 chemical descriptors in a chemoinformatics tool were calculated for 50,000 randomly selected molecules in the original chemical space. To allow visualization, the resulting chemical space was projected onto a two-dimensional plane using generative topographic mapping. The calculated absorbance rates of the chemicals based on cell permeability studies were found to be inversely correlated to the no-observed-effect levels for hepatoxicity after oral administration, as obtained from the Hazard Evaluation Support System Integrated Platform in Japan (r = -0.88, p < 0.01, n = 27). The maximum plasma concentrations and the areas under the concentration-time curves (AUC) of a varied selection of chemicals were estimated using two different methods: simple one-compartment models (i.e., high-throughput toxicokinetic models) and simplified physiologically based pharmacokinetic (PBPK) modeling consisting of chemical receptor (gut), metabolizing (liver), and central (main) compartments. The results obtained from the two methods were consistent. Although the maximum concentrations and AUC values of the 53 chemicals roughly correlated in the liver and plasma, inconsistencies were apparent between empirically measured concentrations and the PBPK-modeled levels. The lowest-observed-effect levels and the virtual hepatic AUC values obtained using PBPK models were inversely correlated (r = -0.78, p < 0.05, n = 7). The present simplified PBPK models could estimate the relationships between hepatic/plasma concentrations and oral doses of general chemicals using both forward and reverse dosimetry. These methods are therefore valuable for estimating hepatotoxicity.

• Journal of Radiation Protection and Research
• /
• v.48 no.1
• /
• pp.15-19
• /
• 2023

Background: Cone beam computed tomography (CBCT) is a specialized medical equipment and plays a significant role in the diagnosis of oral and maxillofacial diseases and abnormalities; however, it is attributed to risk of exposure of ionizing radiation. The aim of the study was to estimate and determine the amount of scattered radiation dose to the thyroid gland in dental CBCT during maxilla and mandible scan. Materials and Methods: The average scattered radiation dose for i-CAT 17-19 Platinum CBCT (Imaging Sciences International) was measured using a Multi-O-Meter (Unfors Instruments), placed at the patient's neck on the skin surface of the thyroid cartilage, with an exposure parameter of 120 kVp and 37.07 mAs. The surface entrance dose was noted using the Multi-O-Meter, which was placed at the time of the scan at the level of the thyroid gland on the anterior surface of the neck. Results and Discussion: The surface entrance dose to the thyroid from both jaws scans was 191.491±78.486 µGy for 0.25 mm voxel and 26.9 seconds, and 153.670±74.041 µGy from the mandible scan, whereas from the maxilla scan the surface entrance dose was 5.259±10.691 µGy. Conclusion: The surface entrance doses to the thyroid gland from imaging of both the jaws, and also from imaging of the maxilla and mandible alone were within the threshold limit. The surface entrance dose and effective dose in CBCT were dependent on the exposure parameters (kVp and mAs), scan length, and field of view. To further reduce the radiation dose, care should be taken in selecting an appropriate protocol as well as the provision of providing shielding to the thyroid gland.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.27 no.2
• /
• pp.129-134
• /
• 2001

Since NNK is one of the most abundant tobacco-specific alkaloids and a strong carcinogenic nitrosamine, it has been used for evaluating a potential of carcinogenicity in the animal models. The present study has attempted to examine the potential of carcinogenicity of NNK in human epithelial cells, from which the cell type the most of cancers including oral cancer and nasal cavity cancer are originated. The cellular model used for the study is a human keratinocyte cell system immortalized by Ad12-SV40 hybrid virus. The cellular system has successfully been used for the carcinogenicity studies because of its limitless life span, epithelial morphology and nontumorigenicity. When cells were treated with a variety of NNK concentrations, levels of saturation density and soft agar colony formation were increased in a dose-dependent fashion. Colonies of large cell aggregates were above 5 at the higher doses. The results indicate that exposure of human cells with NNK induced loss of contact inhibition and increases of anchorage independence and cellular adhesion, which are typical characteristics of the neoplatically transformed cells. When cells were exposed with 100uM NNK for 2hr, mRNA levels of IL-1 and PAI-2 were increased in a dose-dependent manner, but expression of TGF- 1 was not affected. While expression of growth regulatory factors were altered with a short-term exposure, there was no alteration of these factors in the NNK-transformed cells. However, mRNA levels of fibronectin were increased both in the short-term treatment and in the transformation. The results suggest that altered expression of extracellular matrix such as fibronectin following short-term exposure might be fixed in the genome and these altered properties be continuously transfered throughout the cell division. Western blot analysis showed a translocation of PKC- from cytosolic fraction to the particulate fraction, indicating a possible role of NNK in the signal transduction pathway. The present study provided an evidence that NNK in the smoking may be associated with epithelial origin cancer such as oral and nasal cavity cancers. In addition, this study suggested that altered expression of extracellular matrix and PKC may play an important role in the carcinogenic mechanism of NNK.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.31 no.4
• /
• pp.287-293
• /
• 2009

Long-term treatment with glucocorticoid leads to the development of osteoporosis and osteonecrosis. In contrast to the marked inhibitory effect of pharmacological doses of glucocorticoids on bone formation, the relationship between physiological concentrations of glucocorticoids and osteoprogenitor cell proliferation and phenotypes has not been elucidated yet. In addition, the effects of dexamethasone treatment on the proliferation and osteoblastic differentiation of osteoprogenitor cells are also controversial. The purpose of this study was to examine the effects of dexamethasone on the proliferation and osteoblastic differentiation of periosteal-derived cells. Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the cells were further cultured for 21 days in the osteogenic induction medium with different dexamethasone concentrations of 0, 10, and 100 nM. The proliferation and osteoblastic phenotypes of periosteal-derived cells were promoted in dexamethasone-treated cells than in untreated cells. Among the dexamethasone-treated cells, cell proliferation was slightly greater in 10 nM dexamethasone-treated cells than in 100 nM dexamethasone-treated cells. Histochemical staining and the bioactivity of alkaline phosphatase (ALP) were higher in 100 nM dexamethasone-treated cells than in 10 nM dexamethasone-treated cells. Similarly, von Kossa-positive mineralization nodules and calcium content were also more evident in 100 nM dexamethasone-treated cells than in 10 nM dexamethasone-treated cells. These results suggest that dexamethasone enhances the in vitro osteoblastic differentiation of periosteal-derived cells. The present study also demonstrates that higher dexamethasone concentrations reduce the in vitro proliferation of periosteal-derived cells.

• Journal of the Korean Society of Radiology
• /
• v.5 no.6
• /
• pp.343-349
• /
• 2011

This study was aimed to evaluate the absorbed dose in brain of dental radiography. For radiographic exposure, PLD(photoluminescence dosimetry) chips placed in Rando phantom to measurement the absorbed dose to pituitary gland, orbit, maxillary sinus and submandibular glands, thyroid gland, esophagus. Equipments were used Kodak 2200, Kodak 8000C dental radiographic systems and computed tomography(Lightspeed VCT). The absorbed doses were measured at the same exposure parameters and distance by the clinical factor(kV, mA, sec). The result were as follows ; The absorbed dose for intra-oral radiography were 0.02~2.47cGy, the greatest absorbed dose was 2.47cGy for thyroid gland in maxillary right molar projection. the lowest adsorbed dose was 0.02cGy for submandibular glands in lower anterior projection. The absorbed dose for extra-oral radiography were 0.36~3.44cGy of cephalometric method, 0.14~12.82cGy of panoramic method, 8.17~253.63cGy of computed tomography, the greatest adsorbed dose was 253.63cGy for submandibular glands in maxillary CT scan. the lowest adsorbed dose was 0.14cGy for orbit in panoramic method. As a result, extra-oral radiography was measured more than intra-oral radiography. In particular, method which used computed tomography was measured more than 100 times than intra-oral radiography highly. Therefore, you must show a guideline in extra-oral radiography and an effort to reduce absorbed dose is demanded.