Evaluation of Renal Toxicity by Combination Exposure to Melamine and Cyanuric Acid in Male Sprague-Dawley Rats

Son, Ji Yeon,Kang, Yoon Jong,Kim, Kyeong Seok,Kim, Tae Hyung,Lim, Sung Kwang,Lim, Hyun Jung,Jeong, Tae Cheon,Choi, Dal Woong,Chung, Kyu Hyuck,Lee, Byung Mu,Kim, Hyung Sik Korean Society of ToxicologyKorea Environmental Mu 2014 Toxicological Research Vol.30 No.2

Melamine-induced nephrotoxicity is closely associated with crystal formation in the kidney caused by combined exposure to melamine (Mel) and cyanuric acid (CA). However, there are few dosage-finding studies for toxicological evaluation of chronic co-exposure to Mel and CA. The objective of this study was to investigate the possible mechanism by which a Mel and CA mixture lead to renal toxicity in rats. Mel and CA were co-administered to rats via oral gavage for 50 days. Nephrotoxicity was determined by measuring blood urea nitrogen (BUN) and serum creatinine (sCr) levels. Relative kidney weights were significantly increased in rats after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg) mixtures. BUN and sCr levels were significantly increased after Mel and CA co-exposure. Taken together, significant increase in KIM-1, NGAL, and calbindin levels were observed in the urine of rats exposed to Mel+CA (63/6.3 or 630/6.3 mg/kg) compared with the corresponding control group. Histological analysis revealed epithelial degeneration and necrotic cell death in the proximal tubules of the kidney after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg). Our data suggest that Mel-mediated renal toxicity may be influenced by CA concentrations in Mel-contaminated milk or foods.

Evaluation of Renal Toxicity by Combination Exposure to Melamine and Cyanuric Acid in Male Sprague-Dawley Rats

Ji Yeon Son,Yoon Jong Kang,Kyeong Seok Kim,Tae Hyung Kim,Sung Kwang Lim,Hyun Jung Lim,Tae Cheon Jeong,Dal Woong Choi,Kyu Hyuck Chung,Byung Mu Lee,Hyung Sik Kim 한국독성학회 2014 Toxicological Research Vol.30 No.2

Melamine-induced nephrotoxicity is closely associated with crystal formation in the kidney caused by combined exposure to melamine (Mel) and cyanuric acid (CA). However, there are few dosage-finding studies for toxicological evaluation of chronic co-exposure to Mel and CA. The objective of this study was to investigate the possible mechanism by which a Mel and CA mixture lead to renal toxicity in rats. Mel and CA were co-administered to rats via oral gavage for 50 days. Nephrotoxicity was determined by measuring blood urea nitrogen (BUN) and serum creatinine (sCr) levels. Relative kidney weights were significantly increased in rats after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg) mixtures. BUN and sCr levels were significantly increased after Mel and CA co-exposure. Taken together, significant increase in KIM-1, NGAL, and calbindin levels were observed in the urine of rats exposed to Mel+CA (63/6.3 or 630/6.3 mg/kg) compared with the corresponding control group. Histological analysis revealed epithelial degeneration and necrotic cell death in the proximal tubules of the kidney after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg). Our data suggest that Mel-mediated renal toxicity may be influenced by CA concentrations in Mel-contaminated milk or foods.

총수담관결찰이 백서 신세뇨관의 S-100 면역반응에 미치는 영향

金天浩,李永浩,朴景蘭,申台均,金源式 충남대학교 의과대학 지역사회의학연구소 1991 충남의대잡지 Vol.18 No.1

For the study on the changes of S-100 reactivity at the renal tubular epithelium of rats(SpragueDawley, b.w. 250± 20gm. male), the common bile duct ligation was performed under ether anesthesia. At 1st, 3rd, 5th and 7th day after operation, the S-100 immunoreactivity were compared with control rats. The results were as followings; 1. In the control rat, S-100 positive reactions were observed at the collectiong tubule, Henle's loop, distal tubule(partly) and renal papilla. 2. In common bile duct ligated rats, S-100 positive reactions were observed at the proximal convoluted tubule in the rats 1 day after operation, and at the collecting tubule and proximal convoluted tubule in the 3 days after operation.

Harmonious그래프와 Graceful그래프의 연관 관계에 대한 연구

김대식,이천희 청주대학교 산업과학연구소 1987 産業科學硏究 Vol.5 No.-

In this paper, we give an overview of harmonious graphs and graceful graphs, identify the simply sequential and survey graceful graphs of wheels. Finally, we describe β-valuation of wheels which can be used in graceful graphs.

기업의 배당정책 결정요인에 대한 실증연구 : -중국 상해증권거래소의 상장기업을 대상으로-

김천희, 최창훈, 우춘식 숭실대학교 2009 숭실경영연구 Vol.1 No.1

본 연구에서는 1998년부터 2007년까지의 기간에서 중국 상해증권거래소의 상장기업 중에서 표본의 선정방법에 따라 A주 기업 208개를 선정하여 어떤 재무요인이 배당정책의 결정에 영향을 미치는가를 분석하는데 연구의 목적을 두었다. 연구결과를 요약하면 다음과 같다. 첫째, 수익성을 대변하는 변수인 주당순이익의 회귀계수가 배당의 유형과 관계없이 유의한 양(+)의 값을 보임으로써 수익성이 배당정책에 양(+)의 영향을 미치는 것으로 나타났다. 둘째, 기업의 투자기회와 성장기회를 대변하는 변수인 M/B비율과 총자산증가율이 A주의 주식배당과 혼합배당정책에 유의한 양(+)의 영향을 미치는 것으로 나타났다. 투자기회가 많고 성장성이 높은 기업에서 많은 배당을 지급한다는 가설을 지지하는 증거를 발견할 수 있었다. 셋째, 전기배당률의 회귀계수가 A주의 현금배당과 혼합배당에서 유의한 양(+)의 값을 보임 으로써 배당의 안정성이 배당정책에 의미 있는 영향을 미치는 것으로 나타났다. 넷째, 배당의 잔여이론을 대변하는 부채비율과 가처분현금흐름 비율이 부분적으로 배당정책에 영향을 미치는 것으로 나타났다. 다섯째, 소유구조를 대변하는 국유주 비율, 법인주 비율과 유통주 비율에서는 일관된 결론을 얻을 수 없었다. 따라서 소유권구조가 배당정책에 의미 있는 영향을 미친다고 보는 데는 한계가 있는 것으로 판단된다. The purpose of this study was to analyze which financial factors had an affect on deciding divided policy. According to some sampling criteria, in the purpose of this study 208 firms from A shares are selected and the dividend and financial data from the Shanghai Stock Exchange were used. A multiple regression analysis were adopted to empirically test the major purpose of this study with cash dividend ratio, stock dividend ratio and mixed dividend ratio as dependent variables and with the identified some determinant variables as explanatory variables. The results are summarized as follows. First, the empirical tests showed that the earning per share had significantly positive relationship with dividend policy. The regression coefficient of the earning per share had positive value in all type of dividend group. According to this results, the companies with more profit tend to distribute more dividend. Second, M/B ratio and growth rate of total assets, representing firm's investment and growth opportunities significantly affected stock dividend policy from A shares firm. It was supported the residual theory of dividend policy was supported. Company had more investments and growth opportunities, the more dividend was paid. Third, the former dividend ratio has significantly positive relationship with cash dividend policy and mixed dividend policy in sample firms of A shares. It indicates that the stability of dividend has significant influence on dividend policy. Keywords: cash dividend, stock dividend, mixed dividend, residual theory of dividend stability of dividend

새열기형의 임상적 고찰

김장묵,김대식,백승혁,한동렬,김희중,백병준,오천환 순천향의학연구소 2000 Journal of Soonchunhyang Medical Science Vol.6 No.2

Background and Objectives : Branchial cleft anomalies are encountered rarely in clinical practice. We reviewed medical records of branchial cleft anomalies according to age and sex distribution, site distribution, characteristics of mass on physical examination, location of mass, preoperative diagnosis, type of branchial cleft cyst and report our experience with 25 cases of branchial cleft anomalies. Materials and Methods : A review of medical records was performed on 25 cases of branchial cleft anomalies diagnosed in pathologic report from January, 1990 to March, 2000. Result : Sex distribution was 11 male and 14 female, age distribution was most common in third decade which was 8 cases(32%). Site distribution was predominant in left side(13 cases), and in physical examination, the characteristics of the mass was nontender(76%), mobile(60%), soft(80%). The lesion site was submandibular area in 2 cases, upper 1/3 portion of sternocleidomastoid muscle(SCM) in 2 cases, middle 1/3 portion of SCM in 20 cases and parotid area in 1 case. The preoperative diagnosis was branchial cleft cyst in 16 cases, cervical lymphadenitis in 3 cases, tuberculous lymphadenitis in 3 cases, branchial cleft fistula in 1 case, dermoid cyst in 1 case and parotid mass in 1 case. Among 25 cases, first branchial cleft cyst was seen in 4 cases, second branchial cleft cyst in 20 cases and second branchial cleft fistula in 1 case. Conclusion : The clinical history of recurrent neck inflammatory episodes in young patients and nontender, mobile, soft neck mass should raise the suspicion of this entity. Investigation using CT scanning in combination with aspiration is useful. Treatment of all branchial cleft anomalies is complete surgical excision because there is lack of spontaneous regression, a high rate of recurrent infection, the possibility of other diagnosis, and rare malignant degeneration. Complete removal without complications depends on a good understanding of regional embryogenesis, a knowledge of the surrounding structure, and awareness of the different anatomical presentation.

Ethyoene Oxide 폭로 근로자의 말초 임파구 자매염색분체 교환에 관한 연구

황천현,박종태,장성훈,김대성,이원진,김청식,김영환 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.4

Operators of hospital sterilizers who use ethylene oxide(EtO) were studied to determine the exposure of EtO level and the frequency of sister chromatid exchanges(SCEs) from June 12 to July 20, 1997. To evaluate SCEs in the peripheral blood cells, we selected 22 workers at the central supply room of 4 university hospitals and 22 unexposed workers at the same hospitals according to match sex, age, and smoking habit and also did questionnaires. The mean air concentrations(8-hr TWA) of EtO at 4 university hospitals were less than 1 ppm. The SCE frequencies in exposed workers to EtO and controls were normally distributed. The SCE frequencies in exposed workers to EtO and controls were 6.42±0.63, 5.86±0.69, respectively and their differences were statistically significant(p=0.0093). But there were no statistically significant differences in smoking, alcohol intake, coffee drinking. Especially smokers who exposed to EtO were increased SCE statistically significant than the exposed group who did not smoke.

Original Article : Evaluation of Renal Toxicity by Combination Exposure to Melamine and Cyanuric Acid in Male Sprague-Dawley Rats

( Ji Yeon Son ),( Yoon Jong Kang ),( Kyeong Seok Kim ),( Tae Hyung Kim ),( Sung Kwang Lim ),( Hyun Jung Lim ),( Tae Cheon Jeong ),( Dal Woong Choi ),( Kyu Hyuck Chung ),( Byung Mu Lee ),( Hyung Sik Ki 영남대학교 약품개발연구소 2014 영남대학교 약품개발연구소 연구업적집 Vol.24 No.0

Melamine-induced nephrotoxicity is closely associated with crystal formation in the kidney caused by combined exposure to melamine (Mel) and cyanuric acid (CA). However, there are few dosage-finding studies for toxicological evaluation of chronic co-exposure to Mel and CA. The objective of this study was to investigate the possible mechanism by which a Mel and CA mixture lead to renal toxicity in rats. Mel and CA were co-administered to rats via oral gavage for 50 days. Nephrotoxicity was determined by measuring blood urea nitrogen (BUN) and serum creatinine (sCr) levels. Relative kidney weights were significantly increased in rats after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg) mixtures. BUN and sCr levels were significantly increased after Mel and CA co-exposure. Taken together, significant increase in KIM-1, NGAL, and calbindin levels were observed in the urine of rats exposed to Mel+CA (63/6.3 or 630/6.3 mg/kg) compared with the corresponding control group. Histological analysis revealed epithelial degeneration and necrotic cell death in the proximal tubules of the kidney after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg). Our data suggest that Mel-mediated renal toxicity may be influenced by CA concentrations in Mel-contaminated milk or foods.

Influences of Thiopurine Methyltransferase Genotype and Activity on Thiopurine-induced Leukopenia in Korean Patients With Inflammatory Bowel Disease: A Retrospective Cohort Study

Kim, Jae Hak,Cheon, Jae Hee,Hong, Seong Soo,Eun, Chang Soo,Byeon, Jeong-Sik,Hong, Sung Yi,Kim, Bo-Young,Kwon, Soon-ho,Kim, Seung Won,Han, Dong Soo,Yang, Suk-Kyun,Kim, Won Ho Lippincott WilliamsWilkins, Inc. 2010 Journal of clinical gastroenterology Vol.44 No.10

BACKGROUND AND AIM: Myelotoxicity has been shown to be very common in Korean patients with inflammatory bowel disease (IBD) during azathioprine (AZA) or 6-mercaptopurine (6–MP) treatment. The purpose of this study was to investigate the relative risk of the thiopurine methyltransferase (TPMT) and inosine triphosphate pyrophosphatase (ITPA) genotypes and TPMT activity for the development of leukopenia in Korean IBD patients during AZA/6-MP treatment. METHODS: We retrospectively analyzed 286 Korean patients with IBD who had been treated with AZA/6-MP for at least 6 months between June 1996 and September 2006. Common TPMT mutations, including TPMT*1, *2, *3A, *3B, and *3C, and ITPA mutations, including 94C>A and IVS2+21A>C, were determined using a high-performance liquid chromatography method. TPMT activity was measured using liquid chromatography with coupled mass spectrometry/mass spectrometry. RESULTS: Leukopenia occurred in 118 cases (41.3%). TPMT *1/*3C was detected in 7 cases (2.4%), and ITPA 94 C>A was detected in 66 cases (23.1%), including 63 heterozygotes (22.1%) and 3 homozygotes (1.0%). The median TPMT activity was 9.3 U/mL (interquartile range 10.4, range 2.1 to 76.2). Cox regression analysis revealed that patients with heterozygous *3C type TPMT had a higher probability of leukopenia than those with wild type TPMT (P=0.02). Patients with intermediate TPMT activity had a lower probability of leukopenia than those with low activity (P=0.01). However, the ITPA genotype did not affect the risk of leukopenia. CONCLUSIONS: Our data showed that it could be helpful to examine TPMT genotypes and to measure TPMT activity in Korean patients taking AZA/6-MP to predict the development of leukopenia.

소장종양의 임상적 고찰

김해경,김병식,김진천,홍원선,남승우,민영일,정훈용,김해련,하현권,양석균,이재균,최재원,오성태 대한소화기학회 1998 대한소화기학회지 Vol.31 No.1

Background/Aims: Small bowel tumors are uncommon accounting for only 3 to 6% of all gastrointestinal tumors. The diagnosis of small bowel tumors has been usually made at an advanced stage because of the infrequency and absence of symptoms specific for early diagnosis, resulting in poor prognosis. This study was conducted to investigate the clinical features of small bowel tumors in Korea. Methods: We reviewed and analyzed clinical manifestations, laboratory results and survivals in 63 patients with small bowel tumors diagnosed at the Asan Medical Center between June 1989 and January 1996. Results: Among 63 tuors reviewed, 58 were malignant tumors and 5 were benign tumors. The malignant tumors consisted of 25 adenocarcinomas, 15 malignant lymphomas, 12 leiomyosarcomas and 6 metastatic carcinomas. Adenocarcinomas were located mainly in the duodenum and malignant lymphomas in the ileum or duodenum, while leiomyosarcomas were evenly distributed. Clinical symptoms of these patients included abdominal pain (71.4%), palpable mass (12.7%), weight loss (10.0%) and bleeding (8.0%). Anemia and positive stool occult blood test were found in 55.0% and 46.7%, respectively. The median duration of symptoms before the diagnosis was 4 weeks in malignant tumors and 36 weeks in benign tumors. Twenty-seven of 30 patients (90.0%) with duodenal tumors were diagnosed by duodenoscopy, while small bowel series and CT scans detected 9 of 11 (82.0%) and 25 of 35 (71.4%) small bowel tumors, respectively. The incidence of metastasis to regional lymph nodes and distant organs was higher in adenocarcinoma and malignant lymphoma than leiomyosarcoma. The 2-year survival rates for patients with adenocarcinomas, malignant lymphomas, and leiomyosarcomas were 23, 57, and 60%, respectively. Conclusions: These results suggest that small bowel tumors should be considered in patients having unexplained abdominal pain, anemia, and/or positive stool occult blood test.