• Title/Summary/Keyword: repeated dose

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Reducing Effect of Microorganism on Meat and Fish Products by Repeated γ-Irradiation at Low Dose (저선량 감마선 반복조사의 육류와 생선 중 미생물 저감효과)

  • Je, Gil-Soo;Chung, Duck-Hwa;Shim, Won-Bo
    • Journal of Food Hygiene and Safety
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    • v.30 no.1
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    • pp.92-97
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    • 2015
  • The aim of this study is to examine the removal efficiency of pathogen (Escherichia coli O157:H7 and Salmonella typhimurium) on meat and fish products (packing condition: vacuum or not and storage temperature: $4^{\circ}C$ or $-20^{\circ}C$) repeatedly exposed at low-dose gamma irradiation. In case of meat products (beef and chicken), E. coli O157:H7 was not observed at the level of 2 kGy single gamma irradiation and 0.5 kGy repeated gamma irradiation and S. Typhimurium was not observed at the level of 2 kGy single gamma irradiation and 1 kGy repeated gamma irradiation. In case of fish products, E. coli O157:H7 and S. Typhimurium were not detected at the level of 0.5 kGy single and repeated gamma irradiation. These results showed that microorganisms on fish products were more efficiently removed than those of meat products with low-dose gamma irradiation. Generally, each packing condition made no difference. However, the products (fish and meat) stored at $-20^{\circ}C$ needed more higher dose gamma irradiation than products at $4^{\circ}C$.

4 Weeks Repeated Oral Dose Toxicity Studies with LMK02-Jangwonhwan in SD Rats (LMK02의 Sprague-Dawley 랫드를 이용한 4 주간 반복 경구투여 DRF 독성시험)

  • Lyu, Yeoung-Su;Kim, Ji-Hwon;Park, Hyun-Je;Yi, Kyung-Hee;Lee, Jong-Hwa;Kang, Hyung-Won
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.6
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    • pp.1034-1041
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    • 2010
  • The oriental medicine Jangwonhwan, which is a boiled extract of 12 medicinal herbs/mushroom, has been prescribed for patients with cognitive dysfunction and it is originally from the Korean medical text, DonguiBogam(amnesia chapter). Recently, a modified recipe of Jangwonhwan (LMK02-Jangwonhwan) consisting of seven medicinal plants/mushroom, was shown to reduce ${\beta}$-amyloid deposition in the brain of Tg-APPswe/PS1dE9 mouse model of Alzheimer disease. The toxicity of LMK02 was investigated in SD rats by oral repeated adminstration for 4 weeks and we tried to determine test does for 13 weeks repeated study. Quality control of tablet form of LMK02 was established by estimating indicative components, Ginsenoside Rg3 of Red Ginseng and Decursin of Angelicagigas Nakai. The toxicity of LMK02 was investigated in 6 weeks old specific pathogen free (SPF) Sprageu-Dawley rats by oral administration. Each test group were consist of 5 male and 5 female and they received doses of 500, 1,000 and 2,000 mg/kg/day of test substance for 4 weeks. The clinical signs, death rate, body weight, food consumption, ophthalmic examination, urinalysis, hematological and serum biochemistry, organ weight and pathological changes were examined and compared with those of control group. Urinalysis : We observed increase of PRO(p<0.01), SG(p<0.01) in female rats of 1,000 mg/kg/day and 2,000 mg/kg/day(p<0.01). Also, we observed increase of pH and KET in female rats of 1,000 mg/kg/day(p<0.05) and of 2,000 mg/kg/day(p<0.01). WBC in female rats in 1,000 mg/kg/day and 2,000 mg/kg/day were on increase. Hematological test : We observed increase of MCV in male rats of 250 mg/kg/day. (p<0.05) Serum biochemistry test : We found increase of CHO in female rats of 2,000 mg/kg/day(p<0.05). During the experimental period, there were no animals dead or moribund. There were no treatment related changes of general symptom, food and water consumption, organ weight and autopsy According to the results of 4-week repeated dose range finding study, the highest dose was established as 1000 mg/kg for 13-week repeated dose toxicity study and we determined to put 2 more groups by common ratio two.

A 14-day Repeated Dose Oral Toxicity Study of HT042 in Sprague-Dawley Rats (Sprague-Dawley계 흰쥐를 이용한 HT042의 14일 반복 경구투여 독성연구)

  • Song, Jungbin;Lee, Donghun;Kim, Young-Sik;Lee, Seunggyeong;Bae, Jin-Sook;Kim, Hocheol
    • The Korea Journal of Herbology
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    • v.32 no.1
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    • pp.63-68
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    • 2017
  • Objectives : HT042 is a combination of three herbal extracts from the roots of Astragalus membranaceus, the stems of Eleutherococcus senticosus and the roots of Phlomis umbrosa, which has been demonstrated to increase longitudinal bone growth rate. The aim of this study was to assess the safety of HT042 after repeated oral administration. Methods : A 14-day repeated oral dose toxicity study was conducted using male and female Sprague-Dawley rats. HT042 was administered orally at repeated doses of 500, 1,000 and 2,000 mg/kg/day for 14 days. Clinical signs and mortality were observed daily, whereas body weight and food consumption were recorded weekly throughout the experiment. At the end of the study, blood was taken from the posterior vena cava for hematology and serum biochemistry. All organs of the body surface, subcutis, head, thoracic cavity, and abdominal cavity were observed grossly. Then, the internal organs were removed and weighed. Results : No death occurred and no significant changes in clinical sign, body weight, food consumption and serum biochemistry parameters were observed in male and female rats over the study period. Although there were some alterations in hematologic and necropsy findings, and organ weights, these changes were not considered toxicologically significant. Conclusions : These results suggest that the 14-day repeated administration of HT042 does not produce any significant oral toxicity at doses of up to 2,000 mg/kg/day in male and female rats under the present experimental conditions.

Four-Week Repeated Dose Safety Test of Rhus-II Orally Administrated to Rats (랫드에서 옻나무 추출액(Rhus-II)의 4주 반복 투여 안정성 평가)

  • Choi Changsun;Han Dong Un
    • Journal of Food Hygiene and Safety
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    • v.20 no.1
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    • pp.7-12
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    • 2005
  • The purpose of this study was to examine the four week repeated toxicity in Sprague-Dawley rats orally administrated with Rhus-II (water fraction of Rhus Veniciflua). In acute toxicity test, three groups (40 rats of both sex) were administrated different dosages of Rhus-II, 2 g/kg (high dosage group), 1 g/kg, 0.5 g/kg and one group (10 rats of both sex) were received by orally only saline according to the Regulation on Korea Food and Drug Administration, respectively. There was no difference in body weight change, feed intake and water consumption among different dose groups. There was no alteration in relative organ weight by the administration of Rhus-II. No death of abnormal clinical signs was observed during the experimental period. Between the groups orally administered Rhus-II and the control group, there was no statistical significance in urinalysis, hematological test or serum biochemical values. There were no gross findings at final sacrifice. There was no evidence of histopathological alteration mediated by four week treatment with Rhus-II. These results suggest that no observable effect level(NOEL) of the test orally administration was considered to be more than 2g/kg in rats under the conditions employed in this study.

A 4-week Repeated dose Oral Toxicity Study of Mecasin in Sprague-Dawley Rats to Determine the Appropriate Doses for a 13-week, Repeated Toxicity Test

  • Cha, Eunhye;Lee, Jongchul;Lee, Seongjin;Park, Manyong;Song, Inja;Son, Ilhong;Song, Bong-Keun;Kim, Dongwoung;Lee, Jongdeok;Kim, Sungchul
    • Journal of Pharmacopuncture
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    • v.18 no.4
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    • pp.45-50
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    • 2015
  • Objectives: In this study, we investigated the 4-week repeated-dose oral toxicity of gami-jakyak gamcho buja decoction (Mecasin) to develop safe treatments. Methods: In order to investigate the 4-week oral toxicity of Mecasin, we administered Mecasin orally to rats. Sprague-Dawley (SD) rats were divided into four groups of five male and five female animals per group: group 1 being the control group and groups 2, 3, and 4 being the experimental groups. Doses of Mecasin of 500, 1,000, and 2,000 mg/kg of body weight were administered to the experimental groups, and a dose of normal saline solution of 10 mL/kg was administered to the control group. We examined the survival rate, weight, clinical signs, and gross findings for four weeks. This study was conducted under the approval of the Institutional Animal Ethics Committee. Results: No deaths occurred in any of the four groups. No significant changes in weights or food consumption between the control group and the experimental groups were observed. Serum biochemistry revealed that some groups showed significant decrease in inorganic phosphorus (IP) (P < 0.05). During necropsy on the rats, one abnormal macroscopic feature, a slight loss of fur, was observed in the mid dosage (1,000 mg/kg) male group. No abnormalities were observed in any other rats. In histopathological findings, the tubular basophilia and cast of the kidney and extramedullary hematopoiesis of the spleen were found. However, those changes were minimal and had occurred naturally or sporadically. No other organ abnormalities were observed. Conclusion: During this 4-week, repeated, oral toxicity test of Mecasin in SD rats, no toxicity changes due to Mecasin were observed in any of the male or the female rats in the high dosage group. Thus, we suggest that the doses in a 13-week, repeated test should be 0, 500, 1,000, and 2,000 mg/kg respectively.

Renal Safety of Repeated Intravascular Administrations of Iodinated or Gadolinium-Based Contrast Media within a Short Interval

  • Chiheon Kwon;Koung Mi Kang;Young Hun Choi;Roh-Eul Yoo;Chul-Ho Sohn;Seung Seok Han;Soon Ho Yoon
    • Korean Journal of Radiology
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    • v.22 no.9
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    • pp.1547-1554
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    • 2021
  • Objective: We aimed to investigate whether repeated intravascular administration of iodinated contrast media (ICM) or gadolinium-based contrast agents (GBCAs) within a short interval was associated with an increased risk of post-contrast acute kidney injury (PC-AKI). Materials and Methods: This retrospective study included 300 patients (mean age ± standard deviation, 68.5 ± 8.1 years; 131 male and 169 female) who had undergone at least one ICM-enhanced perfusion brain CT scan, had their baseline and follow-up serum creatinine levels available, and had not undergone additional contrast-enhanced examinations 72 hours before and after a time window of interest were included. The study population was divided into three groups: single-dose group and groups of patients who had received multiple contrast administrations in the time window of interest with the minimum contrast repeat interval either within 4 hours (0-4-hour group) or between 4 to 48 hours (4-48-hour group). Multivariable logistic regression analysis was conducted to evaluate the association between AKI and repeated ICM administrations. A similar supplementary analysis was performed including both ICM and GBCA. Results: When ICM was only considered ignoring GBCA, among 300 patients, 207 patients received a single dose of ICM, 58 had repeated doses within 4 hours (0-4-hour group), and 35 patients had repeated doses between 4 to 48 hours (4-48-hour group). Most patients (> 95%) had a baseline estimated glomerular filtration rate (eGFR) of ≥ 30 mL/min/1.73 m2. AKI occurred in 7.2%, 13.8%, and 8.6% of patients in the single-dose, 0-4-hour, and 4-48-hour groups, respectively. In the 0-4-hour and 4-48-hour groups, additional exposure to ICM was not associated with AKI after adjusting for comorbidities and nephrotoxic drugs (all p values > 0.05). Conclusion: Repeated intravascular administrations of ICM within a short interval did not increase the risk of AKI in our study patients suspected of acute stroke with a baseline eGFR of ≥ 30 mL/min/1.73 m2.

Oral Toxicity Study and Skin Sensitization Test of a Cricket

  • Ryu, Hyeon Yeol;Lee, Somin;Ahn, Kyu Sup;Kim, Hye Jin;Lee, Sang Sik;Ko, Hyuk Ju;Lee, Jin Kyu;Cho, Myung-Haing;Ahn, Mi Young;Kim, Eun Mi;Lim, Jeong Ho;Song, Kyung Seuk
    • Toxicological Research
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    • v.32 no.2
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    • pp.159-173
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    • 2016
  • Crickets have been attracting considerable interest in the field of nutrition and toxicology due to the global exhaustion of food resulting from a growing population. The cricket is normally eaten in several countries after roasting, similar to the grasshopper; however, safety evaluation data on cricket powder is limited. Here, we performed general toxicity studies of cricket powder including a single, 2-week repeated dose range evaluation test, a 13-week repeated oral dose toxicity test in Sprague-Dawley rats, a single oral dose toxicity test in Beagle dogs, and a skin sensitization test in guinea pigs following the Organization for Economic Cooperation and Development test guidelines 406 and 408 in addition to Good Laboratory Practice. To investigate the NOAEL and target organs of cricket powder, Sprague-Dawley rats were allocated to 4 groups: vehicle control, 1,250 mg/kg, 2,500 mg/kg, 5,000 mg/kg dose test groups and cricket powder was administered over 13 weeks after single dose and dose range finding studies in rats based on the results of the single oral administration toxicity study in rats and Beagle dogs. The results of the study showed that the NOAEL of cricket powder was over 5,000 mg/kg for both sexes of rats without adverse effects in a 13-week repeated oral toxicity study and there was no skin hypersensitivity reaction. Therefore, our results reveal that crickets can be widely used as a new substitute food or nutrient resource.

Two-Week Repeated Inhalation Toxicity Study of Dimethyl Disulfide in Rats (랫드에서 이황화메틸의 2주 반복투여 흡입독성연구)

  • Kim Jong-Choon;Shin Jin-Young;Shin Dong-Ho;Kim Sung-Ho;Lee Sung-Bae;Han Jung-Hee;Chung Yong-Hyun;Kim Hyeon-Yeung;Park Seung-Chun
    • Toxicological Research
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    • v.20 no.3
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    • pp.273-280
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    • 2004
  • The present study was carried out to investigate the potential toxicity of dimethyl disulfide by a 2-week inhalation in F344 rats. The test article, dimethyl disulfide, was exposed by inhalation to male and female rats at dose levels of 0, 33, 100, or 300 ppm/6 hrs/day for 2 weeks. At the end of treatment period, all males and females were sacrificed. During the test period, clinical signs, mortality, body weights, food consumption, hematology, serum biochemistry, and gross findings were examined. The mean body weights of the male 300 ppm group and the female 33 ppm or higher dose groups were significantly lower than those of the control group, respectively. The mean food consumption at male 300 ppm and female 100 and 300 ppm were significantly decreased compared with the controls. Some treatment-related serum biochemical changes, including decreased alkaline phosphatase at male 300 ppm and female 100 and 300 ppm, reduced total bilirubin at male 300 ppm, and decreased alanine aminotransferase at female 300 ppm, were observed in a dose-dependent manner, but these findings were considered to be of no toxicological significance. There were no adverse effects on mortality, clinical signs, hematology, and necropsy findings in any treatment group. Based on these results, it was concluded that the 2-week repeated dose of dimethyl disulfide by inhalation resulted in suppressed body weight gain and decreased food consumption at the dose of male 300 ppm and suppressed or reduced body weight gain and decreased food consumption at the dose of female 33 ppm or higher. In the present experimental conditions, the no-observed-adverse-effect level (NOAEL) was considered to be 100 ppm/6 hrs/day for male rats and below 33 ppm/6 hrs/day for female rats.

Low-dose Radioactive I-131 Therapy after Total Thyroidectomy for Differentiated Thyroid Cancer (갑상선 분화암 수술 후 저용량 방사성 옥소(I-131)요법)

  • Choi Chung-Jin;Jung Sung-Hoo
    • Korean Journal of Head & Neck Oncology
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    • v.14 no.2
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    • pp.214-219
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    • 1998
  • Objectives: To assess the effectiveness of the low-dose(30mCi) I-131 ablation therapy for remnant thyroid tissue following total thyroidectomy for differentiated thyroid cancer. Methods: Between March 1995 and December 1997, forty-eight patients were given ablative doses(30mCi) of I-131 after total thyroidectomy for differentiated thyroid cancer in the presence of I-131 uptake in remnant thyroid tissue. Effective ablation of remnant thyroid tissue was determined by following I-131 whole body scan. if remnant thyroid tissue remained, we repeated the same management at 6 months interval. Results: Thirty-eight(79.1%) patients had papillary, 8(16.7%) follicular, 1(2.1%) medullary and 1(2.1%) Hurthle cell type cancer. Forty-eight patients underwent total thyroidectomy, among those central neck dissection was performed in 35 cases, and modified radical neck dissection in 14 cases. Postoperative complication developed in 8 cases, which included 4 cases of transient hypoparathyroidism, 1 case of permanent hypoparathyroidism, 2 cases of transient recurrent laryngeal nerve palsy, and 1 case of wound hematoma. There were significant remnant thyroid tissue in 46 cases(95.8%) of patients after total thyroidectomy, which could be ablated by low dose(30mCi) I-131. There were no statistical difference between operative procedures and number of treatment of I-131. Conclusions: These results suggested that repeated low-dose(30mCi) I-131 therapy would be needed, therefore, high -dose I-131 therapy could be considered as ablation therapy for the remnant thyroid tissue after total thyroidectomy for differentiated thyroid cancer.

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Single and Four-week Intravenous Toxicity Studies of DA-3585, a Recombinant Human Erythropoietin, in Rats (재조합 사람 적혈구 조혈인자 DA-3585의 랫드에 대한 단회 및 4주반복 정맥투여 독성시험)

  • Kim, Dong-Hwan;Cho, Hyeon;Kang, Kyung-Koo;Baik, Nam-Gi;Kim, Won-Bae
    • Biomolecules & Therapeutics
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    • v.6 no.2
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    • pp.182-190
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    • 1998
  • DA-3585 is a recombinant human erythropoietin produced by Dong-A pharmaceutical Co. Ltd. using recombinant DNA technique. Recently, recombinant human erythropoietin (rHu-EPO) has been used to treat various types of anemia. In this study, we examined acute and subacute toxicity of DA-3585 in rats. DA-3585 was intravenously administered to rats at dose levels of 0, 6,250, 12,500 and 25,000 lU/kg for single dose toxicity study and at dose levels of 0,100,500 and 2,500IU/kg daily for 4 week-repeated dose toxicity study. In the single dose toxicity study, there were no death, clinical signs and changes in body weight gain related to the treatment. Necropsy revealed no evidence of toxicity related to DA-3585, In the repeated dose toxicity study, all the rats survived throughout the study. There were no treatment-related changes in clinical signs, food and water intake, and body weight. Hematological examination showed increases in the number of erythrocytes, hemoglobin concentration, hematocrit value and mean corpuscular volume, and decrease in the number of platelet in 500 and 2,500 lU/kg dosed groups. Extramedullary hematopoiesis in the spleen and erythroid hyperplasia in the bone marrow were noted as treatment-related histological changes. Toxicologically significant changes were not observed in blood biochemistry, urinalysis, organ weights and in any other examinations. The treatment-related changes observed in this study were hematological or histological changes associated with pharmacological effects of DA-3585. On the basis of the results of this study, LD5n value of DA-3585 was above 25,000 lU/kg and the no-observed-adverse-effect-level was estimated to be 100 lU/kg.

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