• International Journal of Oral Biology
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• 제46권3호
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• pp.99-104
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• 2021

Associations between periodontal infection and cardiovascular disease have been documented. Porphyromonas gingivalis is a well-established periodontal pathogen, and tissue factor (TF) is a key initiator of the coagulation cascade. In this context, P. gingivalis has been reported to enhance TF expression in human endothelial cells. The present study investigated the underlying mechanisms of TF induction by P. gingivalis in human umbilical vein endothelial cells. P. gingivalis increased TF expression in a dose- and time-dependent manner. Not only live bacteria but also glutaraldehyde-fixed bacteria increased TF expression to the same extent. However, sonicates of P. gingivalis did not induce TF expression. Cytochalasin D and SMIFH2, which are inhibitors of actin polymerization and actin nucleation, respectively, inhibited the TF expression induced by P. gingivalis. Finally, TF production was decreased or increased in the presence of various signaling inhibitors, including mitogen-activated protein kinases. These results suggest that P. gingivalis induces endothelial TF expression by a bacterial internalization-dependent mechanism and through diverse signal transduction mechanisms.

• 한국방사선학회논문지
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• 제10권2호
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• pp.139-144
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• 2016

사람 피부 조직에서의 방사선 장해를 연구하는 방법은 실험동물에게 직접적으로 방사선을 노출하여 연구를 수행하게 된다. 이러한 연구방법은 방사선을 실험동물에게 노출시킨 후에 방사선에 의해 손상된 장해조직의 세포를 획득하여 분석을 하게한다. 이것은 시간적으로나 경제적으로도 많은 손실을 수반하게 된다. 이번 연구는 돼지의 피부를 사람의 피부로 가정하여 실험하였다. 돼지피부의 두께를 정하여 돼지피부를 통과한 후 피하조직 밑에서 세포가 직접적으로 받을 수 있는 방사선량을 얻어내어 수식화 하였다. 이번연구의 결과에 따르면 피부조직의 방사선 노출 후 피하조직 밑에서 발생되는 방사선량을 유추해낼 수 있다. 더 나아가 동물실험이 아닌 세포만을 가지고도 방사선에 의한 생체장해분석을 할 수 있는 데 효과적으로 사용할 수 있을 것이다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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• pp.272-278
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• 2004

Recently, Pepe et al. (2003) employed the receiver operating characteristic (ROC) approach to rank candidate genes from a microarray experiment that can be used for the biomarker development with the ultimate purpose of the population screening of a cancer, In the cancer microarray experiment based on n patients the researcher often wants to compare the tumor tissue with the normal tissue within the same individual using a common reference RNA. This design is referred to as a reference design or an indirect design. Ideally, this experiment produces n pairs of microarray data, where each pair consists of two sets of microarray data resulting from reference versus normal tissue and reference versus tumor tissue hybridizations. However, for certain individuals either normal tissue or tumor tissue is not large enough for the experimenter to extract enough RNA for conducting the microarray experiment, hence there are missing values either in the normal or tumor tissue data. Practically, we have $n_1$ pairs of complete observations, $n_2$ 'normal only' and $n_3$ 'tumor only' data for the microarray experiment with n patients, where n=$n_1$+$n_2$+$n_3$. We refer to this data set as a mixed data set, as it contains a mix of fully observed and partially observed pair data. This mixed data set was actually observed in the microarray experiment based on human tissues, where human tissues were obtained during the surgical operations of cancer patients. Pepe et al. (2003) provide the rationale of using ROC approach based on two independent samples for ranking candidate gene instead of using t or Mann -Whitney statistics. We first modify ROC approach of ranking genes to a paired data set and further extend it to a mixed data set by taking a weighted average of two ROC values obtained by the paired data set and two independent data sets.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6549-6556
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• 2013

Leukemia stem cells (LSCs) play important roles in leukemia initiation, progression and relapse, and thus represent a critical target for therapeutic intervention. Hence, it is extremely urgent to explore new therapeutic strategies directly targeting LSCs for acute myelogenous leukemia (AML) therapy. We show here that Angelica sinensis polysaccharide (ASP), a major active component in Dong quai (Chinese Angelica sinensis), effectively inhibited human AML $CD34^+CD38^-$ cell proliferation in vitro culture in a dose-dependent manner while sparing normal hematopoietic stem and progenitor cells at physiologically achievable concentrations. Furthermore, ASP exerted cytotoxic effects on AML K562 cells, especially LSC-enriched $CD34^+CD38^-$ cells. Colony formation assays further showed that ASP significantly suppressed the formation of colonies derived from AML $CD34^+CD38^-$ cells but not those from normal $CD34^+CD38^-$ cells. Examination of the underlying mechanisms revealed that ASP induced $CD34^+CD38^-$ cell senescence, which was strongly associated with a series of characteristic events, including up-regulation of p53, p16, p21, and Rb genes and changes of related cell cycle regulation proteins P16, P21, cyclin E and CDK4, telomere end attrition as well as repression of telomerase activity. On the basis of these findings, we propose that ASP represents a potentially important agent for leukemia stem cell-targeted therapy.

• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.135-143
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• 1993

The investigation was undertaken to determin the altered function and structure of granulation tissue fibroblasts. Human granulation-tissue fibroblasts were cultured from periodontal chronic inflammatory lesions (SBI index : above 3) and compared with healthy gingival connective tissues fibroblasts a control(SBI index : below 1). Granulation tissue fibroblasts proliferated with a slower growth rate and exhibited larger cell size than control cells. Total protein profile of granulation tissue fibroblasts was almost identical to that of control cells with some exception. These results support tha theory that granulation tissue fibroblasts represent a distinct phenotype of fibrotic cells.

• BMB Reports
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• 제50권6호
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• pp.285-298
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• 2017

The cancer stem cell (CSC) hypothesis has captured the attention of many scientists. It is believed that elimination of CSCs could possibly eradicate the whole cancer. CSC surface markers provide molecular targeted therapies for various cancers, using therapeutic antibodies specific for the CSC surface markers. Various CSC surface markers have been identified and published. Interestingly, most of the markers used to identify CSCs are derived from surface markers present on human embryonic stem cells (hESCs) or adult stem cells. In this review, we classify the currently known 40 CSC surface markers into 3 different categories, in terms of their expression in hESCs, adult stem cells, and normal tissue cells. Approximately 73% of current CSC surface markers appear to be present on embryonic or adult stem cells, and they are rarely expressed on normal tissue cells. The remaining CSC surface markers are considerably expressed even in normal tissue cells, and some of them have been extensively validated as CSC surface markers by various research groups. We discuss the significance of the categorized CSC surface markers, and provide insight into why surface markers on hESCs are an attractive source to find novel surface markers on CSCs.

• IMMUNE NETWORK
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• 제13권6호
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• pp.235-239
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• 2013

Encapsulation of tissue has been an area of intense research with a myriad number of therapeutic applications as diverse as cancer, tissue regeneration, and diabetes. In the case of diabetes, transplantation of pancreatic islets of Langerhans containing insulin-producing beta cells has shown promise toward a cure. However, anti-rejection therapy that is needed to sustain the transplanted tissue has numerous adverse effects, and the islets might still be damaged by immune processes. Furthermore, the profound scarcity of healthy human donor organs restricts the availability of islets for transplant. Islet encapsulation allows the protection of this tissue without the use of toxic medications, while also expanding the donor pool to include animal sources. Before the widespread application of this therapy, there are still issues that need to be resolved. There are many materials that can be used, differing shapes and sizes of capsules, and varied sources of islets to name a few variables that need to be considered. In this review, the current options for capsule generation, past animal and human studies, and future directions in this area of research are discussed.

• 약학회지
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• 제46권4호
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• pp.247-257
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• 2002

Persistent organochlorine pesticides and polychlorinated biphenyls (PCBs) have been used intensively in agriculture or industry for a long time. The occurrence of organochlorine pesticides and PCBs in the environment and subsequently in parts of the food chain, resulting in the intake of these compounds by man and animal. The measure of the levels of organochlorine pesticides and PCBs in tissues or blood of human populations are good markers in determining the extent of exposure and in the evaluating the hazards. So, most countriess have conducted initial monitoring programs to determine organochlorine pesticides and PCBs in human tissues. But a few report has been presented in Korea. In this study, $\alpha$-BHC, $\beta$-BHC, ${\gamma}$-BHC, $\delta$-BHC, p,p'-DDT, p,p'-DDD, p,p'-DDE, endrin, dieldein, aldrin and 7 marker PCBs (28, 52, 101, 118, 138, 153, 180) were determined in human blood, adipose tissue and liver tissues collected at autopsy of 10 men and 10 women, 13-79 year of age. Significant differences in the levels of organochlorine pesticides and PCBs between districts where they had lived were found in the following chemicals: total PCB in the blood : $\beta$-BHC, total BHC, p,p'-DDE and total DDT in the adipose tissue : p,p'-DDE, total DDT and PCB 118 in the liver. No significant difference was found in the levels of organochlorine pesticides and PCBs between sexes and ages. Though the levels of organochlorine pesticides and PCBs were relatively lower than that of other countries, we could know that organochlorine pesticides and PCBs have been widely distributed in Korean human body.

• Archives of Pharmacal Research
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• 제28권7호
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• pp.829-838
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• 2005

In order to investigate the residual amounts of organochlorines and polychlorinated biphenyls (PCBs) in Korean human tissues (blood, adipose tissue, liver, kidney cortex, and lung), the samples were collected from the autopsied cadavers of 40 men and 40 women (from teens to seventies of age). ${\alpha}-BHC,\;{\beta}-BHC,\;{\gamma}-BHC,\;{\delta}-BHC$, p,p'-DDT, p,p'-DDD, p,p'-DDE, endrin, dieldein, aldrin, and 7 marker PCBs (28, 52, 101, 118, 138, 153, and 180) were determined in human tissues. The levels of organochlorines and PCB congeners indicated that they have been widely distributed in Korean human body. Positive correlations in terms of age were observed for the following cases: p,p'-DDE, p,p'-DDT, ${\Sigma}-DDT$, PCB 118, PCB 138, PCB 153, and ${\Sigma}-PCB$ in the adipose tissue, and p,p'-DDE in the lung. Concentration of these compounds showed a significant age-related increase. Accumulation of these compounds in aged people revealed that these compounds were more slowly eliminated in our environment and risk assessment was necessary for further proper action. Significant differences in the levels of PCBs between genders were found for PCB 118 in the adipose tissue and PCB 138 in the liver. Positive correlation coefficients between tissues were detected with p,p'-DDE and ${\beta}-BHC$.

• 농업과학연구
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• 제48권2호
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• pp.353-365
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• 2021

Previously, we reported that tissue factor (Tf) was included in the list of differentially expressed genes as an upregulated gene in a rejected porcine heart after xenotransplantation into monkey. In this study, we analyzed that expression of Tf in aortic endothelial cells (pAEC) isolated from alpha 1,3-galactosyltransferase knockout pig in response to allogeneic porcine serum and xenogeneic human serum. The consequence was significant upregulation of Tf expression by responding to human serum compared with porcine serum. To analyze the function of Tf gene as a promoter, we constructed reporter vectors for expression of luciferase linked to 1,246 and 787 base pairs of porcine Tf (pTF1246 and pTF787), and 535 base pairs of human TF (hTF535) sequences including putative promoter regions and AP-1 biding site at the 5' end. The reporter vectors were transfected into pAEC including cytomegalovirus enhancer/chicken β-actin (CAG)-luciferase vector as a control. Luciferase assay showed that all of the promoters were insufficient to express luciferase compared with CAG promoter in basic culture conditions. Notably, pTF1246, pTF787, and hTF535 led to a significant increase of luciferase expression in response to human serum compared with porcine serum while no change of CAG. pTF1246 and pTF787 showed higher expression than hTF535. Taken together, our findings suggest that pTF1246 and pTF787 promoters could mediate target gene expression specifically at xenogeneic stress condition.