• Journal of Food Hygiene and Safety
• /
• v.20 no.1
• /
• pp.7-12
• /
• 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.

• Tribology and Lubricants
• /
• v.34 no.6
• /
• pp.284-291
• /
• 2018

Ball-milling for reactant powders in advance and using an induction heating system for Ni-Al intermetallic coating process are known to enhance the reactivity of combustion synthesis. In this work, the effects of the charging weight ratio of ball to powder in ball-milling for reactant Ni-Al powders and the synthesizing temperature in induction heating on sliding wear behavior of the coating layers are investigated. Sliding wear behavior of the coating layers is examined against a tool steel using a pin-on-disc type sliding wear machine. As results, wear of the coating layer ball-milled without ball was severely worn out at the sliding speed of 2m/s, regardless of the synthesizing temperature in induction heating. However, the wear rate of the coating layers at the sliding speed was remarkably decreased with increasing the charging weight ratio of ball in ball-milling for reactant powders. This can be explained by the fact that the void in the coating layer is disappeared and the coating layer is densified by the ball-milling. The evidence showed that pitting damages were disappeared on the worn surface of ball-milled coating layer. Consequentially, the Ni-Al intermetallic coating layer could have better wear resistance at all sliding speed ranges with the ball-milling for reactant powders in advance.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.9
• /
• pp.2663-2670
• /
• 2013

The purpose of stability testing is to provide evidence about how the quality of a drug varies with time under the influence of a variety of environmental factors. In this study, erythropoietin (EPO) was analyzed under different pH (pH 3 and pH 9) and temperature ($25^{\circ}C$ and $40^{\circ}C$) conditions according to current Good Manufacturing Practice (cGMP) and International Conference on Harmonisation (ICH) guidelines. The molecular weight difference between intact EPO and deglycosylated EPO was determined by SDS-PAGE, and aggregated forms of EPO under thermal stress and high-pH conditions were investigated by size exclusion chromatography. High pH and high temperature induced increases in dimer and high molecular weight aggregate forms of EPO. UPLC-ESI-TOF-MS was applied to analyze the changed modification sites on EPO. Further, normal-phase high-performance liquid chromatography was performed to identify proposed glycan structures and high pH anion exchange chromatography was carried out to investigate any change in carbohydrate composition. The results demonstrated that there were no changes in modification sites or the glycan structure under severe conditions; however, the number of dimers and aggregates increased at $40^{\circ}C$ and pH 9, respectively.

• Biomedical Science Letters
• /
• v.19 no.3
• /
• pp.188-194
• /
• 2013

Ulcerative colitis (UC) is an inflammatory bowel disease, which is a chronic gastrointestinal disorder. Adenophorae Radix (AR) has been used as a traditional medicine for various diseases including strengthening cardiac function, allaying a fever, and easing pain and cough. However, the regulatory effects of AR in intestinal inflammation are not yet understood. This study attempted to determine the effect of AR in dextran sulfate sodium (DSS) - induced colitis in mice. The colitis mice were induced by drinking water containing 5% DSS for 7 days. The results showed that mice treated with DSS showed remarkable clinical signs, including weight loss, and reduced colon length. Administration of AR attenuated weight loss, colon shortening and inhibited the levels of interleukin (IL) - 6 in DSS - treated colon tissues. These results provide experimental evidence that AR might be a useful therapeutic medicine for patients with UC.

• Korean Journal of Pharmacognosy
• /
• v.39 no.1
• /
• pp.60-67
• /
• 2008

The subcronic toxicity of BDR-29, a herbal preparation of Cassiae Semen, Prunellae Spica, Tribuli Fructus, and Uncariae Rhamulus et Uncus, was examined in male and female Sprague-Dawley rats. Rats were treated with the test substance at a dose 5 mg/kg, 50 mg/kg and 500 mg/kg intragastrically for 13 weeks. No death and abnormal clinical signs were observed throughout the administration period. There were not significantly different from control group in net body weight gain, food and water consumption, organ weight, gross pathological findings, and urine analysis among the groups rats treated with different doses of the BDR-29. Hematological findings and biochemical examination revealed no evidence of specific toxicity related to BDR-29. From these results, no observation effect level (NOEL) of BDR-29 is 500 mg/kg/day under the condition employed in this study.

• Journal of Ecology and Environment
• /
• v.45 no.1
• /
• pp.24-39
• /
• 2021

Background: To address the lack of evidence supporting invasion by three invasive plant species (Imperata cylindrica, Lantana camara, and Chromolaena odorata) in tropical ecosystems, we compared the ecophysiological and leaf anatomical traits of these three invasive alien species with those of species native to Sempu Island, Indonesia. Data on four plant traits were obtained from the TRY Plant Trait Database, and leaf anatomical traits were measured using transverse leaf sections. Results: Two ecophysiological traits including specific leaf area (SLA) and seed dry weight showed significant association with plant invasion in the Sempu Island Nature Reserve. Invasive species showed higher SLA and lower seed dry weight than non-invasive species. Moreover, invasive species showed superior leaf anatomical traits including sclerenchymatous tissue thickness, vascular bundle area, chlorophyll content, and bundle sheath area. Principal component analysis (PCA) showed that leaf anatomical traits strongly influenced with cumulative variances (100% in grass and 88.92% in shrubs), where I. cylindrica and C. odorata outperformed non-invasive species in these traits. Conclusions: These data suggest that the traits studied are important for plant invasiveness since ecophysiological traits influence of light capture, plant growth, and reproduction while leaf anatomical traits affect herbivory, photosynthetic assimilate transport, and photosynthetic activity.

• Journal of Nutrition and Health
• /
• v.29 no.1
• /
• pp.70-76
• /
• 1996

This study was undertaken to investigate the effect on the Cd accumulation in long-term Cd poisoned rats. 40 male weaning Sprague Dawley rats weighting 80-90g were divided into 4 groups (LCuLFeCd : low Cu, Fe and Cd group, ACuLFeCd : adequate Cu, low Fe and Cd group, ACuAFeCd : adequate Cu, adequate Fe and Cd group) according to Cu and Fe levels (Cu 0.5ppm, 8.5ppm : Fe 6ppm, 40ppm) for 12 weeks. There were no significant difference in water intake, feed intake, and body weight gain according to dietary Cu and Fe consumption. But the mean food intake and body weight gain of adequate Fe groups(LCuAFeCd, ACuAFeCd) were higher than those of deficient Fe groups (ACuLFeCd, LCuFeCd)in long-term Cd poisoned rats. The mean Cd levels of serum, liver, kidney, and urine in ACuAFeCd group were lower than those of Cu and /or Fe deficient groups. But the mean fecal Cd excretion of ACuAFeCd group was higher than that of Cu and/or Fe deficient groups. And the mean Cd retention amount of ACuAFeCd group was lower than those of Cu and/or Fe deficinet groups. In conclusion, these results provide an evidence that adequate Cu and Fe intakes can decrease Cd accumulation in rats. Therefore, in the point of increasing environmental Cd contamination, adequate Cu and Fe intakes must be suggested to prevent Cd accumulations.

• The Korean Journal of Physiology and Pharmacology
• /
• v.21 no.1
• /
• pp.99-106
• /
• 2017

Obesity is a critical risk factor for the hypertension. Although angiotensin II (Ang II) in obese individuals is known to be upregulated in obesity-induced hypertension, direct evidence that explains the underlying mechanism for increased vascular tone and consequent increase in blood pressure (BP) is largely unknown. The purpose of this study is to investigate the novel mechanism underlying Ang II-induced hyper-contractility and hypertension in obese rats. Eight-week old male Sprague-Dawley rats were fed with 60% fat diet or normal diet for 4 months. Body weight, plasma lipid profile, plasma Ang II level, BP, Ang II-induced vascular contraction, and expression of regulatory proteins modulating vascular contraction with/without Ang II stimulation were measured. As a result, high fat diet (HFD) accelerated age-dependent body weight gaining along with increased plasma Ang II concentration. It also increased BP and Ang II-induced aortic contraction. Basal expression of p-CPI-17 and myosin light chain (MLC) kinase was increased by HFD along with increased phosphorylation of MLC. Ang II-induced phosphorylation of CPI-17 and MLC were also higher in HFD group than control group. In conclusion HFD-induced hypertension is through at least in part by increased vascular contractility via increased expression and activation of contractile proteins and subsequent MLC phosphorylation induced by increased Ang II.

• International Journal of Human Ecology
• /
• v.13 no.2
• /
• pp.53-67
• /
• 2012

This study uses the 1999-2009 Korean Time Use Survey to explore how mothers' employment affects parental time spent in activities that may relate to their children's weight. Specifically, it estimates two-part regression models to assess the effects of maternal employment upon the amount of time mothers spend in activities potentially related to their preschool children's eating and physical activity. The findings suggest that working mothers and those mothers who work longer hours allocate significantly less time in food preparation, eating with the child, and supervising the child's physical activity than mothers who are not employed and those who work fewer hours. The paper also finds that spouses of working mothers do not allocate more time to these activities to offset the reduction in mothers' time. Also, using local unemployment rates as instrumental variables, maternal employment is found to allow mothers to spend significantly more time on food preparation and family meals, although its effect on mothers' total childcare time is negative. Several aspects of Korean society may have made the relationship between maternal employment and childhood weight issues different from what was found in other countries.

• Toxicological Research
• /
• v.19 no.2
• /
• pp.123-131
• /
• 2003

This study was carried out to assess the combined repeated dose, reproduction and developmental toxicities of benzoyl peroxide for OECD SIDS (Screening Information Data Set) program. Male and female Sprague-Dawley rats were exposed to benzoyl peroxide at dose levels of 0, 250, 500 and 1,000 mg/kg/day for 29 days for males and for 41-51 days for females. No deaths were found in all animals including control group during exposure period. No hematological effects attributable to benzoyl peroxide were observed in all treated groups. Significant decrease in the weight of testes and epididymis were observed in males at 1,000 mg/kg/day. In females at 1,000 mg/kg/day, slight histopathological effects in uterus such as epithelial vacuolation or hyperplasia were observed. No treatment-related changes in precoital time and rate of copulation, fertility and gestation period were noted in all treated groups. There was no evidence of teratogenic effect of benzoyl peroxide, but body weight of pups at 1,000 mg/kg/day was significantly decreased. NOAEL for combined repeated dose and reproduction/developmental toxicity was 500 mg/kg/day.