• Journal of Yeungnam Medical Science
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• v.8 no.1
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• pp.127-135
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• 1991

Successful middle ear surgery requires the availability of al safe, effective bonding material. Side effect caused by synthetic materials have led to the use of biologic adhesive. However, they carry the risk of transmission of infectious diseases if they are prepared from pooled human blood. The adhesive strength of ammonium sulfate fibrin adhesive produce an adhesive strength that is half that of the homologous commercial product. It is, however, good enough for use in several otolaryngological operations, tympanoplasty, facial nerve repair, reconstruction of ossicles, reconstruction of posterior wall of ear canal and obliteration of frontal sinus and mastoid antrum using bone dust.

• The Korean Society of Law and Medicine
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• v.10 no.2
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• pp.455-492
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• 2009

(Background) Recent biotechnological breakthroughs are shedding new lights on various ethical and legal issues about human biological material. Since Rudolph Virchow, a German pathologist, had founded the medical discipline of cellular pathology, issues centering around human biological materials began to draw attention. The issues involving human biological materials were revisited with more attention along with series concerns when the human genome map was finally completed. Recently, with researches on human genes and bioengineering reaping enormous commercial values in the form of material patent, such changes require a society to reassess the present and future status of human tissue within the legal system. This in turn gave rise to a heated debate over how to protect the rights of material donors: property rule vs. no property rule. (Debate and Cases) Property rule recognizes the donors' property rights on human biological materials. Thus, donors can claim real action if there were any bleach of informed consent or a donation contract. Donors can also claim damages to the responsible party when there is an infringement of property rights. Some even uphold the concept of material patents overtaking. From the viewpoint of no property rule, human biological materials are objects separated from donors. Thus, a recipient or a third party will be held liable if there were any infringement of donor's human rights. Human biological materials should not be commercially traded and a patent based on a human biological materials research does not belong to the donor of the tissues used during the course of research. In the US, two courts, Moore v. Regents of the University of California, and Greenberg v. Miami Children's Hospital Research Institute, Inc., have already decided that research participants retain no ownership of the biological specimens they contribute to medical research. Significantly, both Moore and Greenberg cases found that the researcher had parted with all ownership rights in the tissue samples when they donated them to the institutions, even though there was no provision in the informed consent forms stating either that the participants donated their tissue or waived their rights to ownership of the tissue. These rulings were led to huge controversy over property rights on human tissues. This research supports no property rule on the ground that it can protect the human dignity and prevent humans from objectification and commercialization. Human biological materials are already parted from human bodies and should be treated differently from the engineering and researches of those materials. Donors do not retain any ownership. (Suggestions) No property rule requires a legal breakthrough in the US in terms of donors' rights protection due to the absence of punitive damages provisions. The Donor rights issue on human biological material can be addressed through prospective legislation or tax policies, price control over patent products, and wider coverage of medical insurance. (Conclusions) Amid growing awareness over commercial values of human biological materials, no property rule should be adopted in order to protect human dignity but not without revamping legal provisions. The donors' rights issue in material patents requires prospective legislation based on current uncertainties. Also should be sought are solutions in the social context and all these discussions should be based on sound medical ethics of both medical staffs and researchers.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.679-690
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• 2008

Purpose: The aim of this study was to investigate the effects of EMD on demineralized root surface using human periodontal ligament cells and compare the effects of root conditioning materials(tetracycline(TCN), EDTA). Material and Methods: Dentin slices were prepared from the extracted teeth and demineralized with TCN and EDTA. Demineralized dentin slices were incubated at culture plate with 25, 50 and $100{\mu}g/ml$ concentration of EMD. Cell attachment, alkaline phosphatase activity test, protein synthesis assay and scanning electronic microscopic examination were done. Results: Cells were attached significantly higher in EMD treated group at 7 and 14 days. Cell numbers were significantly higher in EMD treated group. Alkaline phosphatase activity was significantly higher in EMD treated group at 7 and 14 days. Protein synthesis was significantly higher in EMD treated group at 7 and 14 days. Conclusion: Enamel matrix derivatives enhance the biologic activities of human periodontal ligament cells on demineralized root surface and its effects are dependent on the concentration of EMD.

• Korean Journal of Head & Neck Oncology
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• v.25 no.1
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• pp.28-32
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• 2009

Background : The most frequently reported risk factors for head and neck suamous cell carcinoma are smoking and alcohol. But in a recent overview, human papilloma virus(HPV) infection was revealed the important carcinogenic factor in oropharyngeal cancer. We aimed to clarify whether HPV directly effects on the oncogenesis and biologic behavior of hean and neck squamous cell carcinoma by comparison with infection prevalence, and physical status of virus. Material and Method : We used HPV genotyping DNA chip(Biocore, Korea, Seoul) arrayed by multiple oligonucleotide probes of L1 sequence of 26 types of HPV and HPV genotypes are identified by fluorescence scanner. The copy numbers of HPV E2 and E6 open reading frames(ORF) were assessed using a TaqMan-based 5'-exonuclease quantitative real-time PCR assay. The ratio of E2 to E6 copy numbers was calculated to determine the physical status of HPV-16 viral gene. Results : We observed a significant difference in HPV prevalence between tonsillar cancer group and control group(73.1% vs. 11.6%), and most of the HPVs were type 16(87.2%) and integrated(94.1%) state. In terms of oral tongue cancer, we demonstrate that 30.5% has integrated HPV-16 in cancer tissue. But Glottic cancer only 1% is related to HPV-16 integration. Conclusion : This study revealed significant relationship of HPV prevalence with oropharyngeal and oral tongue squamous cell carcinoma. Most of HPV were 16 type and integrated or mixed, HPV-16 integration could be directly related to the carcinogenesis.

• Korean Journal of Head & Neck Oncology
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• v.23 no.1
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• pp.21-25
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• 2007

Background：Squamous cell carcinoma(SCC)of the palatine tonsils represents approximately 15-23% of all intraoral SCC. The most frequently reported risk factors for oropharyngeal cancer are smoking and alcohol. In a recent overview of HPV and tonsillar squamous cell carcinoma(TC), 51% contained HPV DNA, and HPV-16 being the most frequent type. We aimed to clarify whether HPV directly effects on the oncogenesis and biologic behavior of TC by comparison with infection prevalence, and physical status of virus. Material and Method：We used HPV genotyping DNA chip(Biocore, Korea, Seoul) arrayed by multiple oligonucleotide probes of L1 sequence of 26 types of HPV and HPV genotypes are identified by fluorescence scanner. The copy numbers of HPV E2 and E6 open reading frames(ORF) were assessed using a TaqMan-based 5'-exonuclease quantitative real-time PCR assay. The ratio of E2 to E6 copy numbers was calculated to determine the physical status of HPV-16 viral gene. Results：We observed a significant difference in HPV prevalence between 52 TCs and 69 CFTs(73.1% vs. 11.6%), and most of the HPVs were type 16(87.2%)and non-episomal(94.1%) state. Conclusions：This study regarding HPV infection prevalence and mechanism in the largest population of palatine tonsillar squamous cell carcinoma with chronic follicular tonsillitis revealed significant difference pf HPV prevalence between TC and CFT. Most of HPV were 16 type and integrated or mixed, HPV-16 integration could be directly related to tonsillar carcinogenesis.

• Journal of the Korean Society of Radiology
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• v.12 no.4
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• pp.481-489
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• 2018

In MRI examination, when irradiating the human body with RF Pulse to acquire images, the portion of the irradiated RF Pulse energy is absorded into the human body, and this will affect the temperature of the human body. If a metal is inserted into the human body even if the same RF Pulse energy is applied, the SAR value increases and the body temperature changes due to the increase in the electromagnetic wave conductivity of the metal. So we measure and compared with the change in the SAR and temperature in the implant material of the dental implant in Brain MRI examinations. Experiments were performed on a human head model using a 64MHz and 128 MHz RF Pulse frequency generated by a 3.0 Tesla MRI apparatus. And then changed material of dental implants to Titanium and $Al_2O_3$. Using the XFDTD program, the changes in SAR and body temperature around the head were examined. When with Titanium the SAR value and temperature of Brain increased, but with $Al_2O_3$ showed lower SAR and temperature as compared with Titanium. The dental implants were low in SAR and temperature of the head in $Al_2O_3$, which are electrical insulators with low electrical conductivity, compared to Titanium, which is an electrical conductor. It is necessary to study the biologic effect of patient with brain MRI when titanium dental implant material is inserted in the future. Because the maximum value of SAR is much higher than the limit when dental implant material is Titanium. In addition, it is necessary to use an implant of $Al_2O_3$ material to reduce the SAR value and temperature of the Brain in Brain MRI examination.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.1
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• pp.95-104
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• 2007

I. Objective The primary requirement of an endodontic root canal sealer is the biologic compatibility, because they remain in close contact with living periapical tissues over a long period of time. The aim of this study was the evaluation of cytotoxicity and genotoxicity of resin-based root canal sealers, AH 26 and ADSEAL. II. Material & Methods In this study, human periodontal ligament cells, human oral cancer cells (KB) and mouse osteoblasts (MC-3T3-E1) were used. Specimens of AH26, ADSEAL were eluted with culture medium for 1, 3, 5 and 7 days. Cytotoxicity was evaluated by using tetrazolium bromide reduction assay (MTT assay) for mitochondrial enzyme activity and cell viability. Genotoxicity was evaluated by using alkaline single cell gel electrophoresis assay (Comet assay). Also cell apoptosis induced by AH 26 was detected by Hoechst33258 staining. III. Results AH 26 and ADSEAL exhibited cytotoxic effects in all investigated cell groups. Genotoxicity was also noted for both sealers in mouse osteoblasts (MC-3T3-E1). But, ADSEAL presented significantly low cytotoxicity and genotoxicity compared with AH 26. Cytotoxicity and genotoxicity induced by AH 26 resulted in apopotosis. IV. Conclusion Our results clearly indicate that the recently invented ADSEAL has better biocompatibility than another resin based root canal sealer, AH 26. However ideal root canal sealer should have not only biocompatibility but also satisfactory physico-chemical properties such as sealing ability and stability. Thus continuous studies and developments should follow.

• Korean Journal of Head & Neck Oncology
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• v.15 no.1
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• pp.3-8
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• 1999

Objective: The expression of Ki67, a proliferation marker, and p27, a cyclin dependent kinases(CDKs) inhibitor, has been studied in various human neoplasms. This study was carried out to determine whether these markers are useful in distinguishing benign from malignant lesions of the thyroid or predicting biologic behavior of malignant lesions. Material and Methods: Using immunohistochemical techniques with monoclonal antibodies to Ki67 and p27, we analyzed the expression of Ki67 and p27 in various thyroid disorders(25 follicular adenomas, 47 follicular carcinomas, 16 papillary carcinomas, 20 adenomatous goiters and 40 normal thyroid tissues). The labeling indices(LIs) were determined by counting cells expressing these markers in 1000 cells per immunostained slide. Results: Neoplastic thyroid diseases showed higher expression of Ki67 and lower expression of p27 than non-neoplastic diseases(p<0.05). The expression of p27 was significantly different between follicular adenomas($LI=55.4{\pm}5.7$) and follicular carcinomas($LI=23.2{\pm}10.2$). There was, however, no significant correlation between the degree of Ki67 and p27labeling indices and types of carcinoma or clinical aggressiveness of diseases. Conclusion: The degree of Ki67 and p27 expression was useful in distinguishing between benign from malignant thyroid lesions, particulary between follicular adenoma and follicular carcinoma, but was not directly proportional to the tumor aggressiveness.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.9 no.1
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• pp.15-37
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• 2003

Objective: We are aimed to identify anti-tumor effects of Curcuma longa L. on the stomach cancer cells through molecular biologic methods. Material & Methods: We used AGS as human stomach cancer cells obtained from American Type Culture Collection. The boiled extract of Curcuma longa L. $5{\mu}l$ (Sample I), $10{\mu}l$ (Sample II) was treated to cultural media(ml) for 0, 6, 12, 24, 48 hours. We measured the killing effect on stomach cancer cells through Trypan blue exclusion test and the suppressive effect on viability of stomach cancer cells via MTT assay. For identification of its anticancer mechanism, the revelation of Bcl-2, Bcl-XL, and Bax which are genes related to apoptosis using the quantitative RT-PCR, change of mitochondria membrane permeability and membrane potential via flow cytometry, the cycle of cell mitosis, caspase cleavage and annexin V staining were examined. Results: 1. showed significant killing effect on stomach cancer cell than the control group with a time(6 hours later) and density dependent manner, which was statistical significance. 2. Extract of Curcuma longa L. showed suppressive effect on viability of stomach cancer cells that each test groups had more suppressive effects on viability of stomach cancer cells than the control group with a time(6 hours later), which was statistical significance.(p<0.05) 3. In the test about the revelation of genes related to apoptosis, the revelation of Bcl-2 and Bcl-XL decreased with a density manner which was statistical significance. but the revelation of Bax was not changed with statistical significance. 4. Extract of Curcuma longa L. caused apoptosis by decreasing the absorbance of mitochondria with statistical significance, and also induced apoptosis by decreasing the membrane potential of mitochondria. 5. Extract of Curcuma longa L. destructed the cell cycle of cell mitosos. 6. Cell apoptosis was induced by extract of Curcuma longa L. certificated by method of caspase cleavage and annexin V staining. Conclusion: This experiment showed that Curcuma longa L. has anti-tumor effect with statistical significance. This is in vitro experiment and basic experiment on Curcuma longa L.. We hope more progressive research on Curcuma longa L. will go on and its anti-tumor effects will be more practically identified.

• The Journal of Internal Korean Medicine
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• v.24 no.2
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• pp.290-299
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• 2003

Background : Nowadays many researches about it s cure are going on world widely since cancer is one of the most human health threatening diseases. In Chinese and North Korean medicine, Duchesnea india(Audra.) Foche. is practically used to treat many kinds of cancer, but in Korea it is rarely used. So, we need to scientifically identify anti-tumor effects of Duchesnea india(Audra.) Foche. Objective : We are aimed to identify anti-tumor effects of Duchesnea india(Audra.) Foche. on the stomach cancer cells through molecular biologic methods. Material & Methods : We used AGS as stomach cancer cells from American Type Culture Collection. We added the boiled extract of Duchesnea india(Audra.) Foche. $5{\mu}l$(Sample I), $10{\mu}l$(Sample II) to cultural media(ml)for 0,6, 12, 24, 48 hours. We measured the killing effect on stomach cancer cells through Tryphan blue exclusion test and the suppressive effect on viability of stomach cancer cells via MTT assay. the quantitative RT-PCR was used to examine their effect on the revelation of Bcl-2, Bcl-XL, and Bax, which are genes related to apoptosis. We measured change of mitochondria membrane permeability and membrane potential via flow cytometry. Result : 1. The killing effect on stomach cancer cells showed that each test groups killed more stomach cancer cells than the control group with a time(6 hours later) and density dependent manner, which was statistical significance. 2. The suppressive effect on viability of stomach cancer cells showed that each test groups had more suppressive effects on viability of stomach cancer cells than the control group with a time(6 hours later), which was statistical significance. 3. In the test about the revelation of genes related to apoptosis, the revelation of Bcl-2 and Bcl-XL decreased with a density manner which was statistical significance. but the revelation of Bax was not changed with statistical significance. 4. As a result of this test, Duchesnea india(Audra.) Foche. caused apoptosis by decreasing the absorbance of mitochondria with statistical significance. and also induced apoptosis by decreasing the membrane potential of mitochondria. Conclusion : This experiment showed that Duchesnea india(Audra.) Foche. has anti-tumor effect with statistical significance. This is in vitro experiment and basic experiment on Duchesnea india(Audra.) Foche. We hope more progressive researchs on Duchesnea india(Audra.) Foche. will go on and its anti-tumor effects will be more practically identified.