• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.635-640
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• 1992

Two cases of lingual masses were observed among 500 Fischer 344 (F344) rats which were used as control and treated animals in a 2 year carcinogenicity study in Toxicology Research Center, Korea Research Institute of Chemical Technology. The masses grossly appeared as tan, pedunculated, fungiform on the dorsal aspect of the base of the tongues. They were approximately $1.5{\times}1.2{\times}0.3cm$ in size. The microscopic features consisted of acanthosis, hyperkeratosis, papillary projection with connective tissue cores and multifocal chronic active inflammation with hair shafts. The results observed support the epigenetic mechanism of tumorigenesis which is caused by Physical stimuli of foreign bodies. Both of the masses were diagnosed as papillomas with the incidence rate of 0.4%(1/250) in each sex on the basis of the gross and microscopic features.

• Korean Journal of Veterinary Pathology
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• v.1 no.2
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• pp.107-118
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• 1997

The anticarcinogenic effects of allyl methyl trisulfide(AMT) and methyl propyl disulfide(MPD) were studied in a 28 weeks rat multi-organ carcinogenesis model. Tumor incidence rate was decreased by AMT or MPD treatment comparing with the positive control. AMT treatment significantly decreased the incidence of neoplastic and preneoplastic lesions in the kidney thyroid gland urinary bladder alimentary tract lung and Zymbal's gland. MPD also inhibited incidence of noplastic and preneoplastic lesions in the liver kidney urinary bladder alimentary tract lung and Zymbal's gland but increased that in the thyroid gland. GST-p positive foci in the liver were slightly decreased by AMT or MPD. There was no significant histopathological lesions in AMT or MPD treated group without pretreatment of carcinogens.

• Korean Journal of Veterinary Research
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• v.45 no.1
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• pp.29-37
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• 2005

13-week orally repeated dose toxicity was investigated to ascertain the toxic effects of Aristolochiae radix in F344 rats at dose levels of 0, 1 (0.003 AA, aristolochic acid, mg/kg), 5 (0.014 AA mg/kg), 25 (0.068 AA mg/kg), 125 (0.34 AA mg/kg), and 500mg/kg (AA 1.36 mg/kg). No mortalities were found in any of the dose groups including vehicle control groups of both sexes during the study period. Hematologic and serum biochemical examinations revealed no changes related to the test item in any of the dose groups of both sexes. However, gross findings at necropsy implicated thickening of the stomach wall. In histopathological examinations, prominent findings related to the test item treatment were observed in the stomach and urinary bladder. There were squamous cell papilloma, squamous cell hyperplasia, ulceration and erosion observed in the non-glandular stomach. Squamouse cell hyperplasia was observed at dose levels of more than 125 mg/kg in both sexes and squamous cell papilloma was observed at dose level of 500 mg/kg in both sexes. The incidence and severity of these proliferating lesions including squamous cell hyperplasia and squamous cell papilloma increased with dose dependency. Transitional cell hyperplasia was also observed in the urinary bladder at dose levels of more than 25 mg/kg in both sexes and the incidence and severity of the lesion increased with dose dependency. In conclusion, the toxic changes related to the test item treatment were observed in the stomach and urinary bladder, and the no-observed-adverse-effect level (NOAEL) was estimated to be 5 mg/kg/day for both males and females in F344 rats.

• Korean Journal of Mathematics
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• v.29 no.2
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• pp.333-344
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• 2021

In the present paper, we study three-dimensional f-Kenmotsu manifolds admitting the Schouten-Van Kampen connection. We study the concircular curvature tensor of a three-dimensional f-Kenmotsu manifold with respect to the Schouten-Van Kampen connection. Finally, we have cited an example of a three-dimensional f-Kenmotsu manifold admitting Schouten-Van Kampen connection which verify our results.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2002.11a
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• pp.12-20
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• 2002

1. 질병명 : Interstitial pneumonia 2. 본질명의 개요 역사 및 역학 Michael R Elwell, Joel F Mahler, G N Rao: “ Have You Seen This\ulcorner" ; Inflammatory Lesions in the Lungs of Rats. Toxicologic Pathology, 25: 529-531, 1997. Male and female F344 rats, approximately 19 weeks old, from prechronic toxicity studies performed for NTP/NIEHS over a period of several years at different laboraories located throughout the US. The rats were supplied by 2 different production colonies located in the eastern and western areas of the US. Gross findings ㆍ In some rats the lesions were noted as pale or tan foci in the lungs Microscopic findings ㆍ A prominent increase in perivascular lymphocytes ㆍ A variable increase in the amount of peribronchiolar lymphoid tissues ㆍ Frequently an inflammatory cell exudate within the alveolar spaces ㆍ Focal hyperplasia of alveolar type 2 cells Similar lung lesions were not observed in B6C3F1 mice concurrently on study with affected rats. Similar lung lesions were not observed in F344 rats at the end of 2-year NTP studies. Virus, mycoplasma, bacterial serology, bacterial culture, protozoal identification: negative EM: ㆍ No virus particles were identified. ㆍ Rod shaped bacteria were observed in the alveolar spaces. ㆍ Bacteria were not observed in the bronchi/ bronchioles of rats with alveolar organism. (omitted)

• Nutrition Research and Practice
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• v.4 no.6
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• pp.470-476
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• 2010

The resistant dextrin NUTRIOSE$^{(R)}$, developed from starch, is expected to act as a prebiotic. The aim of this study was to determine the effects of NUTRIOSE$^{(R)}$ on cecal parameters, short-chain fatty acid (SCFA) concentrations, and fecal excretion in rats. In an initial experiment, twenty-four male Fischer F344 rats were randomly assigned to one of the following four treatments for 14 days: G0 (control diet), G2.5 (control diet+2.5% of dextrin), G5 (control diet + 5% of dextrin), and G10 (control diet + 10% of dextrin). After 14 days, total cecal weight, cecal content, and cecal wall weight were significantly increased in G5 and G10 compared to G0. At the same time, cecal pH was significantly lower in G10 compared to G0. Total SCFA concentration was significantly higher in G10 than in G5, G2.5, and G0, and significantly higher in G5 than in G0. Acetate, butyrate, and propionate concentrations were significantly increased in G5 and G10 compared to the controls. In a second trial based on a similar design, eighteen male Fischer F344 rats were treated with a control diet supplemented with 5% of dextrin or 5% of fructo-oligosaccharide. The results obtained with NUTRIOSE$^{(R)}$ were similar to those obtained with the fructo-oligosaccharide. In a third experiment, two groups of 5 Fischer F344 rats were orally treated with 100 and 1,000 mg/kg NUTRIOSE$^{(R)}$, respectively, and from 18% to 25% of the dextrin was excreted in the feces. The results of these three studies show that the consumption of NUTRIOSE$^{(R)}$, by its effects on total cecal weight, cecal content, cecal wall weight, pH, and SCFA production, could induce healthy benefits since these effects are reported to be prebiotic effects.

• Korean Journal of Pharmacognosy
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• v.49 no.2
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• pp.124-131
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• 2018

Phytolaccae Radix has long been used as a traditional indigenous medicine to cure edema and rheumatism. However, there is insufficient background information on toxicological evaluation of Phytolaccae Radix extract to support the safe use. Therefore, we conducted a series of standardized, OECD and KFDA guidelines compliant in vivo study, to find a dose levels for the 13 weeks toxicity study. The extract of Phytolaccae Radix was administered orally to F344 rats at dose levels of 0, 500, 1000 and 2000 mg/kg/day for 2 weeks. Each group was composed to five male and five female rats. In the result, there were no test article-related adverse changes in clinical signs, body weight, food consumption, ophthalmology, hematology, clinical chemistry, gross finding at necropsy and organ weight examination. Therefore, we recommend that 2000 mg/kg/day is a highest treatment group in 13-week exposure study.

• Journal of Korean Public Health Nursing
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• v.29 no.2
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• pp.344-353
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• 2015

Purpose: The objective of this study is to identify factors associated with perceived health status of married immigrant women. Methods: Data were collected from 65 married immigrant women. The measurements were Symptom checklist-48, Acculturative Stress Scale, Parenting Stress Index(PSI), and Personal Resource Questionnaire(PQR). Descriptive, T-test, ANOVA test, Pearson correlation and multiple regression analyses were used. Results: There were significant differences in perceived health status according to satisfaction with the married life(F=8.819, p=0.000), and help from husband(F=6.308, p=.003). There was also a significant relationship between perceived health status and perceived economic status (F=8.006, p=.001), acculturative stress (r=.560, p<.01), parenting stress (r=.662, p<.01) and social support (r=-.289, p<.05). The result of multiple regression analysis showed a significant association of parenting stress with perceived health status of married immigrant women (${\beta}=0.397$, p=0.037). Conclusion: Comprehensive interventions designed to enhance the health of married immigrant women, including prevention of acculturative stress, parenting stress and improving social support may be helpful in mitigating health in married immigrant women.

• Toxicological Research
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• v.14 no.4
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• pp.577-585
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• 1998

Cadmium is an important industrial and environmental pollutant and has adverse effects on cell growth and metabolism, although the mechanisms of its cellular toxicity are still unclear. This study was performed to elucidate the cytotoxic mechanism of cadmium in the viewpoint of oxidative stress and cytoskeleton alterations in WB-F344 rat liver epithelial cells. 200 $\mu\textrm{M}$ $CdCl_2$ caused a severe disassembling of microtubule and micro filament and an apparent cell retraction under an observation with fluorescence micoscope. (equation omitted)-tubulin and F-actin protein were highly thiolated at 20 min and then disappeared from 1 hour after the treatment of 200 $\mu$M CdCl$_2$in the immunoblot analysis. Intracellular GSH was decreased from 1hr to 24 hrs by 66.6 or 200 $\mu\textrm{M}$ of $CdCl_2$. Intracellular protein thiol was also decreased by 22.2, 66.6 and 200 $\mu\textrm{M}$ of $CdCl_2$ at 1 hour after its treatment. The product of lipid peroxidation (malondialdehyde) was increased from 4 hrs by 66.6 and 200$\mu\textrm{M}$ of $CdCl_2$. These data indicate that cadmium induces oxidative stress involving disassembling of microtubule and micro filament, thiolation of (equation omitted)-tubulin and actin protein, depletion of GSH and protein thiol, and increase of lipid peroxidation.

• Korean Journal of Veterinary Research
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• v.48 no.3
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• pp.337-345
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• 2008

There are accumulating evidences that high levels of dietary iron may play a role in colon carcinogenesis. Elevated iron status has been associated with oxidative stress. Phytic acid (PA) functions as an antioxidant by chelating divalent cations and prevents formation of reactive oxygen species responsible for cell injury and carcinogenesis. The protective effect of PA was investigated on formation of aberrant crypt foci (ACF) induced by azoxymethane (AOM) in iron-overloaded male F344 rats. After acclimation with AIN-93G purified diet (35 ppm Fe, normal control diet) for one week, animals were fed iron-overloaded diet (350 ppm Fe) and PA (0.5% or 2% PA in water) for 8 weeks. Animals received two (1st and 2nd week) injections of AOM (15 mg/kg b.w.) to induce colonic ACF. The colonic mucosa was examined for the total numbers of aberrant crypt (AC) and ACF after staining with methylene blue. The blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. Iron-overloaded diet increased the concentration of iron in liver of the rats. But iron-related parameters in blood were not changed among experimental groups. The numbers of ACF per colon and AC per colon were $178.8{\pm}33.2$ and $448.4{\pm}110.2$ in the iron-overloaded F344 rats. The total AC was significantly increased, compared with normal-diet AOM control group (p < 0.05). The treatments of PA at the dose of 0.5% slightly decreased the number of ACF and AC per colon to $153.6{\pm}29.5$ and $396.3{\pm}107.5$. However, there were no significant differences in the total numbers of ACF and AC between the AOM control group and PA (0.5% or 2%)-treated groups. These results suggest that PA may not affect the formation of ACF or AC induced by AOM in ironoverloaded F344 rats.