• Toxicological Research
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• 제31권2호
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• pp.203-211
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• 2015

Trichloroacetonitrile is used as an intermediate in insecticides, pesticides, and dyes. In Korea alone, over 10 tons are used annually. Its oral and dermal toxicity is classified as category 3 according to the globally harmonized system of classification and labelling of chemicals, and it is designated a toxic substance by the Ministry of Environment in Korea. There are no available inhalation toxicity data on trichloroacetonitrile. Thus, the present study performed inhalation tests to provide data for hazard and risk assessments. Sprague-Dawley rats were exposed to trichloroacetonitrile at concentrations of 4, 16, or 64 ppm for 6 hour per day 5 days per week for 13 weeks in a repeated study. As a result, salivation, shortness of breath, and wheezing were observed, and their body weights decreased significantly (p < 0.05) in the 16 and 64 ppm groups. All the rats in 64 ppm group were dead or moribund within 4 weeks of the exposure. Some significant changes were observed in blood hematology and serum biochemistry (e.g., prothrombin time, ratio of albumin and globulin, blood urea nitrogen, and triglycerides), but the values were within normal physiological ranges. The major target organs of trichloroacetonitrile were the nasal cavity, trachea, and lungs. The rats exposed to 16 ppm showed moderate histopathological changes in the transitional epithelium and olfactory epithelium of the nasal cavity. Nasal-associated lymphoid tissue (NALT) and respiratory epithelium were also changed. Respiratory lesions were common in the dead rats that had been exposed to the 64 ppm concentration. The dead animals also showed loss of cilia in the trachea, pneumonitis in the lung, and epithelial hyperplasia in the bronchi and bronchioles. In conclusion, the no-observed-adverse-effect level (NOAEL) was estimated to be 4 ppm. The main target organs of trichloroacetonitrile were the nasal cavity, trachea, and lungs.

• 대한수의학회지
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• 제33권3호
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• pp.513-524
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• 1993

mechanisms for the hypocholesterolemic effects of $\beta$-glucan remain unclear. Rats were divided into 3 groups ; normal control group, atherogenic group(oral administration of cholesterol 40 mg/kg/day plus vit. $D_2$ 320,000 IU/kg/day), $\beta$-glucan treatment group(atherogenic treatment plus $\beta$-glucan 0.135 g/kg/day). The $\beta$-glucan treatment group showed moderate increases of serum lipids concentration compared with atherogenic group. In histopathological examination, aortas showed no critical lesions. The total fecal neutral sterols and bile acids excreted for 6 days was increased compared with both normal and atherogenic group. To compare effects of soluble fiber and insoluble fiber extracted from barley on postprandial lipemia, 5 healthy male adults ingested on separate days a low-fiber(total dietary fiber 2.61g) control meal or dietary fiber-enriched(12.61g) meals. Fasting and postprandial blood samples were obtained for 6.5h and serum lipids were analyzed. The serum total lipids, total cholesterols, LDL & VLDL-cholesterol were markedly reduced with soluble fiber-enriched meals, but no decrease with insoluble fiber-enriched meals. These results suggest that mechanisms for the hypocholesterolemic effect of $\beta$-glucan on rats were due to the inhibition of cholesterol absorption in the intestinal lumen and acceleration of cholesterol catabolism in the liver. And the soluble dietary fiber($\beta$-glucan) has the hypocholesterolemic effect by dropping serum LDL & VLDL-cholesterol in the clinical study.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.633-639
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• 2005

Frequently used for humans as a nonsteroidal anti-inflammatory drug, naproxen has been known to induce ulcerative gastric lesions. The present study was undertaken to investigate the in vivo therapeutic effect of astaxanthin, isolated from a Xanthophyllomyces dendrorhous mutant, against naproxen-induced gastric antral ulceration in rats. The rats were treated with three doses of astaxanthin [1, 5, and 25 mg/kg body weight (B.W.), respectively] once daily for 2 weeks after pretreatment of 80 mg of naproxen/kg B.W. twice daily for 3 days, while the control rats received only 80 mg of naproxen/kg B.W. twice daily for 3 days. The oral administration of astaxanthin (1,5, and 25 mg/kg B.W.) showed a curative effect against naproxen (80 mg/kg B.W.)-induced gastric antral ulcer and reduced the elevated lipid peroxide level in gastric mucosa. In addition, astaxanthin treatment resulted in significant increase in the activities of radical scavenging enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. A histologic examination clearly proved that acute gastric mucosal lesion induced by naproxen nearly disappeared after the astaxanthin treatment. These results suggest that astaxanthin eliminated the lipid peroxides and free radicals induced by naproxen and may be a potential candidate for remedy of gastric ulceration.

• Journal of Periodontal and Implant Science
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• 제27권1호
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• pp.45-59
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• 1997

Platelet-derived growth factor(PDGF) has been shown to play an important role in periodontal regeneration. The purpose of the present study was to examine the distribution of PDGF in experimentally created periodontal intrabony defects after flap surgery with various bone graft materials. Six healthy mongrel dogs were used in this study. Three-wall bony defects were created in maxillary and mandibular premolars, inflammation induced by wire ligation and injection of impression material into the defects. Eight weeks later, the experimental lesions thus obtained were treated by plain flap surgery(control group), flap surgery plus autogenous bone graft(autogenous bone group), flap surgery plus Biocoral graft(Biocoral group), or flap surgery plus bioglass graft(bioglass group), which were randomly assigned to the defects. After 4, H, and 12 weeks postoperatively, 2 dogs were sacrificed at each time and 1he specimens were taken for histological examinations and immunohistochemical examinations for PDGF. In the control defects the amount of new bone formation was minimal. In the autogenous bone and Biocoral group new bone was deposited around implanted particles and the amount of new bone was increased with time. A large number of bioglass particles exibited a central excabation and bone formation could be observed in the central excabation as well as around the particles. The expression of PDGF was low in the control group. The expression of PDGF in Biocoral group was increased at 1, H week, but decreased at 12 week. The increased PDGF expression in autogenous bone and bioglass group was maintained to the end of the experiment.

• 대한소아치과학회지
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• 제31권2호
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• pp.223-227
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• 2004

Lymphangioma는 림프관에 나타나는 양성종양으로 림프관의 증식을 특징으로 한다. 이 종양의 대부분은 출생 시에 나타나며 종양의 95%정도가 10세 이전에 나타난다. 구강내에 발생하는 경우에는 혀에서 가장 호발하며 거설증을 야기한다. 대개 양측성으로 혀의 전방 2/3부위에 나타나며 불규칙한 회색과 핑크빛을 띤 소절형태를 보인다. 본 증례 모두에서 환아들은 출생당시 혀에 lymphangioma를 지니고 태어나 거설증을 보였으며 이로 인해 개교합과 하악과 성장 양상을 나타내었다. Lymphangioma에 의한 비정상적인 혀의 비대에 의해 환아의 구강과 두개안면부의 주위조직에 대한 적응 결과로 나타난 소견을 관찰하고 관련문헌을 고찰하여 다소의 지견을 얻었기에 보고하는 바이다.

• Tuberculosis and Respiratory Diseases
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• 제50권2호
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• pp.245-251
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• 2001

저자들은 신장의 혈관근지방종을 동반한 폐임파관평활근종증 1예를 경험하였기에 폐임파관평활근종증에 대한 문헌고찰과 함께 보고하는 바이다.

• 치위생과학회지
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• 제15권2호
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• pp.238-245
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• 2015

본 연구는 지각과민처치제에 항균 물질을 첨가하여 항균실험 및 지각과민처치제의 세포독성실험을 실시하여 다음과 같은 결과를 얻었다. 항균실험에서는 Micro Prime은 항균 약물의 농도가 높을수록 항균력도 높게 나타나 각 그룹간의 항균 범위는 통계적인 유의차를 나타내었다(p<0.05). Hurri Seal에서는 gallic acid 항균 약물 농도가 높을수록 항균력이 높게 나타났지만(p<0.05), tetracycline을 함유한 desensitizer에서는 농도가 높을수록 항균효과는 떨어지는 것으로 나타났다(p<0.05). 또한 chlorhexidine과 cetylpyridinium chloride에서는 대조군에서만 차이를 나타내고(p<0.05), 각 실험군에서 차이를 나타내지 않았다. 세포독성도를 평가한 결과 Micro Prime은 미약한 세포독성을 나타냈으며, Hurri Sea은 심한 세포독성을 나타냈다. 이상의 연구결과로 지각과민처치제에 항균물질을 첨가할 경우 우수한 항균력이 나타났기 때문에 지각과민 환자의 동통을 줄여 줄 것으로 사료되며 항균성을 가진 지각과민처치제로 사용이 가능할 것으로 판단된다.

• Restorative Dentistry and Endodontics
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• 제24권3호
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• pp.495-502
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• 1999

Recently root caries is reported as an increasing oral disease Many researchers studied in vivo and in vitro enamel lesions but due to its peculiar structure and different chemical composition compared to the enamel, little effort has been made to root caries study. The purpose of this study is to compare and to evaluate the effect of pH on the progression of artificial root caries lesion. Under the constant degree of saturation, the specimens were divided into 4 groups(pH 4.3, 5.0, 5.5, 6.0). Each group was immersed in acid buffer solution for 1, 3, 5, 7 days and examined using the polarizing microscope. The results were as follows: 1. The body of the lesion in the dentin showed higher degree of positive birefringence compared to sound dentin. 2. The rate of progression of the lesion slowed as the pH increased. 3. In all groups, the lesion progressed rapidly at the initiation or the experiment but increased gradually as time elapsed. In conclusion, the study shows that the pH in the acid buffer solution influenced the rate of progression of the lesion in artificial root caries. Compared to the previous enamel study, the initial pattern of the lesion progressed rapidly and as time elapsed increased gradually.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.41-59
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• 1991

This study was performed to elucidate the distribution and correlation of immunoglobulin G subclasses with the degree of inflammation in the experimentally induced rat pulp and periapical pathoses. The pulp exposures were made in 108 mandibular 1st molars of 54 rats and the teeth were left open to the oral environment The animals were sacrified at 3, 7, 15, 30, 60 and 90 days after pulp exposure, and examined microscopically and radiographically Seventy one specimens were routinely sectioned at the thickness of 4 - $6{\mu}$ and stained with Hematoxylin - eosin for histologic examination, with toluidine blue for mast cells, and with the primary antibodies against rat IgG subclasses by using the Avidin - Biotin complex method. The following results were obtained: 1. As the degree of inflammation of rat pulp and periapeces intensified, the number of IgG subclass containing cells per unit area, especially IgG2a and IgG2c, decresased. 2. The IgG2c cells were most predominantly found in the lesions with slight inflammation, IgG1 cells in mild or severe inflammation, and IgG2a cells in moderate inflammation. 3. IgG subclass containg cells were more predominantly observed in the periapical granuloma than periapical abscess or cyst(p<0.01). 4. IgG2a containing cells were predominant in pulp inflammation, IgG1 containing cells in periapical granuloma, IgG2a cells and IgG1 cells in periapical abscess, and IgG2a cells were significantly predominant in periapical cyst. 5. The number of IgG subclass containing cells and mast cells in periapical tissue decreased with time lapse after pulp exposure. And correlation index between mast cells and IgG1, IgG2a, IgG2b was stastically high.

• Journal of Periodontal and Implant Science
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• 제26권2호
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• pp.522-530
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• 1996

Most dentists are very interested in laser therapy on the intraoral soft tissue lesions because they want to accomplish the analgesic and aseptic surgery with little or no bleeding. In order to determine the difference of pain threshold according to different gingival tissues with or without inflammation, 25 patients with inflammatory periodontal disease and 10 volunteers with good general and oral health were selected as the inflamed group and the normal group, respectively. Interdental papilla, marginal gingiva, attached gingiva, and alveolar mucosa were irradiated by the contact delivery($300{\mu]m$ fiber optic, for 5 seconds) of a pulsed Nd:YAG laser(EN.EL.EN06O, Italy). And the laser power was gradually increased from 0.5W by the increment of 0.1W. The highest laser power was recorded as the first painful power when the painful gesture was recognized at first. The difference of the first painful power of laser according to different gingival tissues with or without inflammation was statistically analyzed by paired t-test in MICROSTAT program. Following results were obtained: 1. In the comparison related with the inflammation, the first painful power was significantly lower in the inflamed group than in the normal group, regardless of interdental papilla and marginal gingiva(p<0.05). 2. In the comparison related with the tissue structure, the first painful. power was significantly lower in alveolar mucosa than in attached gingiva(p<0.05). The results suggest that, for the painless therapy by a pulsed-Nd:YAG laser irradiation, the laser surgery over 2.0W of power should be necessarily accomplished under the local anethesia, and the local anesthesia should be considered according to the degree of inflammation, the tissue structure, and the purpose of laser therapy.