• 폴리머
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• 제33권1호
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• pp.7-12
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• 2009

PLGA미립구는 주사제형과 같은 형태로 조직공학적 응용에 이용할 수 있다. 본 연구에서는 미립구 제조시 에밀젼 형성조건에 대한 영향과 미립구 표면에 세포를 부착시키는 방법에 대하여 연구하였다. BSA를 함유하는 PLGA미립구는 수중유형(O/W)과 수중유중수형(W/O/W) 용매증발법을 이용하여 제조하였다. 미립구의 초기방출효과제어와 PLGA분해의 과정에서 발생되는 지연시간을 개선시키기 위하며 알긴산나트륨을 수상에 용해시켜 사용하였다. 미립구에 부착된 세포의 형태를 전자주사현미경(SEM)을 이용하여 분석하였고 PLGA미립구에 배양된 인간디스크세포의 증식은 MTT분석을 이용하였으며 이를 통하여 PLGA미립구 표면에 세포가 부착되었음을 확인하였다. 본 연구는 BSA가 함유된 알긴산/PLGA미립구를 이용하여 조직공학적 응용이 가능한 주사제형으로서의 가능성을 제안하였다.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.735-750
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• 2018

BACKGROUND: The major challenge of tissue engineering is to develop constructions with suitable properties which would mimic the natural extracellular matrix to induce the proliferation and differentiation of cells. Poly(${\varepsilon}$-caprolactone)-poly(ethylene glycol)-poly(${\varepsilon}$-caprolactone) (PCL-PEG-PCL, PCEC), chitosan (CS), nano-silica ($n-SiO_2$) and nano-hydroxyapatite (n-HA) are biomaterials successfully applied for the preparation of 3D structures appropriate for tissue engineering. METHODS: We evaluated the effect of n-HA and $n-SiO_2$ incorporated PCEC-CS nanofibers on physical properties and osteogenic differentiation of human dental pulp stem cells (hDPSCs). Fourier transform infrared spectroscopy, field emission scanning electron microscope, transmission electron microscope, thermogravimetric analysis, contact angle and mechanical test were applied to evaluate the physicochemical properties of nanofibers. Cell adhesion and proliferation of hDPSCs and their osteoblastic differentiation on nanofibers were assessed using MTT assay, DAPI staining, alizarin red S staining, and QRT-PCR assay. RESULTS: All the samples demonstrated bead-less morphologies with an average diameter in the range of 190-260 nm. The mechanical test studies showed that scaffolds incorporated with n-HA had a higher tensile strength than ones incorporated with $n-SiO_2$. While the hydrophilicity of $n-SiO_2$ incorporated PCEC-CS nanofibers was higher than that of samples enriched with n-HA. Cell adhesion and proliferation studies showed that n-HA incorporated nanofibers were slightly superior to $n-SiO_2$ incorporated ones. Alizarin red S staining and QRT-PCR analysis confirmed the osteogenic differentiation of hDPSCs on PCEC-CS nanofibers incorporated with n-HA and $n-SiO_2$. CONCLUSION: Compared to other groups, PCEC-CS nanofibers incorporated with 15 wt% n-HA were able to support more cell adhesion and differentiation, thus are better candidates for bone tissue engineering applications.

• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3131-3135
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• 2015

Objective: To investigate whether the expression of serum soluble neural cell adhesion molecule (sNCAM) is associated with hepatic encephalopathy (HE) in hepatocelular carcinoma (HCC) patients. Materials and Methods: The Oncomine Cancer Microarray database was used to determine the clinical relevance of NCAM expression in different kinds of human cancers. Sera from 75 HCC cases enrolled in this study were assessed for expression of sNCAM by enzyme linked immunosorbent assay (ELISA). Results: Dependent on the Oncomine Cancer Microarray database analysis, NCAM was down regulated in 10 different kinds of cancer, like bladder cancer, brain and central nervous system cancer, while up-regulated in lung cancer, uterine corpus leiomyoma and sarcoma, compared to normal groups. Puzzlingly, NCAM expression demonstrated no significant difference between normal and HCC groups. However, we found by quantitative ELISA that the level of sNCAM in sera from HCC patients with HE ($347.4{\pm}151.9ng/ml$) was significantly more up-regulated than that in HCC patients without HE ($260.3{\pm}104.2ng/ml$), the p-value being 0.008. sNCAM may be an important risk factor of HE in HCC patients, the correlation coefficients was 0.278 (P<0.05) on rank correlation analysis. Conclusions: This study highlights that up-regulated level of serum sNCAM is associated with HE in HCC patients and suggests that the high expression can be used as an indicator.

• 동의생리병리학회지
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• 제17권2호
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• pp.574-579
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• 2003

Methicillin-resistant Staphylococcus aureus (MRSA) has been emerging worldwide as one of the most important hospital and community pathogens. Therefore, new agents are needed to treat the MRSA. In the present study, we investigated antimicrobial activity of ethyl acetate, methanol, and water extracts of Curcuma longa L. (C. longa) aganist clinical isolates of MRSA. The ethyl acetate extract of C. long a demonstrated a higher antibacterial activity than the methanol extract or water extract. Since the ethyl acetate extract was more active than other extracts, we examined whether ethyl acetate extract may restore the antibacterial activity of β-lactams and alter the adhesion and invasion of MRSA to human mucosal fibroblasts (HMFs). In the checkerboard test, ethyl acetate extract of C. longa markedly lowered the MICs of ampicillin and oxacillin against MRSA. In the bacterial adhesion and invasion assay, MRSA intracellular invasion were notably decreased in the presence of 0.125 - 2 mg/ml of C. longa extract compared to the control group. These results suggest that ethyl acetate extract of C. longa may have antibacterial activity and the potential to restore the effectiveness of β-lactams against MRSA, and inhibit the MRSA adhesion and invasion to HMFs.

• IMMUNE NETWORK
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• 제2권1호
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• pp.25-34
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• 2002

Background: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial hyperplasia and joint destruction. The synovial fibroblasts express cell adhesion molecules and have a role in adhesive interation with inflammatory cells in synovial tissue. It has been suggested that hypoxic conditioins are thought to exist in arthritic joints, and several studies indicate that reactive oxygen species (ROS) produced in hypoxic condition can initiate events that lead to pro-adhesive changes via increased expression of adhesion molecules. So, this study wsa designed to examine whether antioxidant can inhibit hypoxia-induced expression of ICAM-1 in cultured human synovial fibroblasts. Methods: Synovial fibroblasts were isolated from synovial tissue in patients with RA and cultured at hypoxic condition. Antioxidant, PDTC (pyrrolidine dithiocarbamate) were pre-treated for an hour before the hypoxic culture and synovial fibroblasts were harvested at 0, 6, 12, 24, 48 hours time points. Cell surface ICAM-1 expression in synovial fibroblasts was examined by the flow cytometric analysis. To analyse the expression of ICAM-1 mRNA, reverse-transcriptase polymerase chain reaction (RT-PCR) was performed. The levels of cytokines in culture supernatants were measured by ELISA, and activation of NF-${\kappa}B$ was analysed by electrophoretic mobility shift assay. The adhesive reaction between synovial fibroblasts and lymphocytes was assayed by measurement of fluorescent intensity of BCECF-AM in lymphocytes. Results: Hypoxic stimuli up-regulated the ICAM-1 expression as well as the adhesive interaction of human synvial fibroblasts to lymphocytes in a time-dependent manner, and PDTC inhibited hpyoxia-induced ICAM-1 expression and cell-cell interaction. PDTC also inhibited the hypoxia-induced activation of intracellular transcription factor, NF-${\kappa}B$. PDTC decreased the amount of hypoxia-induced production of IL-$1{\beta}$ and TNF-${\alpha}$. Conclusion: These studies demonstrate that PDTC inhibit the hypoxia-induced expression of the adhesion molecule, ICAM-1 and activation of NF-${\kappa}B$ in cultured human synovial fibroblasts.

• The Korean Journal of Physiology and Pharmacology
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• 제24권5호
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• pp.395-402
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• 2020

This study has investigated the effect of a potent bioflavonoid, troxerutin, on diabetes-induced changes in pro-inflammatory mediators and expression of microRNA-146a and nuclear factor-kappa-B (NF-κB) signaling pathway in aortic tissue of type-I diabetic rats. Male Wistar rats were randomly divided into four groups (n = 6/each): healthy, healthy-troxerutin, diabetic, and diabetic-troxerutin. Diabetes was induced by streptozotocin injection (60 mg/kg; intraperitoneally) and lasted 10 weeks. Troxerutin (150 mg/kg/day) was administered orally for last month of experiment. Inflammatory cytokines IL-1β, IL-6, and TNF-α, as well as intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule (VCAM), cyclooxygenase-II (COX-II), and inducible-nitric oxide synthase (iNOS) were measured on aortic samples by enzyme-linked immunosorbent assay. Gene expressions for transcription factor NF-κB, interleukin-1 receptor-associated kinase-1 (IRAK-1), TNF receptor-associated factor-6 (TRAF-6), and microRNA-146a were determined using real-time polymerase chain reaction. Ten-week diabetes significantly increased mRNA levels of IRAK-1, TRAF-6, NF-κB, and protein levels of cytokines IL-1β, IL-6, TNF-α, adhesion molecules ICAM-1, VCAM, and iNOS, COX-II, and decreased expression of microRNA-146a as compared with healthy rats (p < 0.05 to p < 0.01). However, one month treatment of diabetic rats with troxerutin restored glucose and insulin levels, significantly decreased expression of inflammatory genes and pro-inflammatory mediators and increased microRNA level in comparison to diabetic group (p < 0.05 to p < 0.01). In healthy rats, troxerutin had significant reducing effect only on NF-κB, TNF-α and COX-II levels (p < 0.05). Beside slight improvement of hyperglycemia, troxerutin prevented the activation of NF-κB-dependent inflammatory signaling in the aorta of diabetic rats, and this response may be regulated by microRNA-146a.

• The Journal of Advanced Prosthodontics
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• 제12권6호
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• pp.369-375
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• 2020

PURPOSE. This study evaluated the availability of multi-directionally forged (MDF) titanium (Ti) as a component of removable partial dentures (RPDs). MDF-Ti remarkably improved the mechanical properties of RPDs due to its ultrafine-grained structure. MATERIALS AND METHODS. The wear resistance, plaque adhesion, and machinability of MDF-Ti were tested. As controls, commercially pure (CP) titanium was used for wear, plaque adhesion, and machinability tests. For wear resistance, the volume losses of the titanium teeth before and after wear tests were evaluated. Plaque adhesion was evaluated by the assay of Streptococcus mutans. In the machinability test, samples were cut and ground by a steel fissure bur and carborundum (SiC) point. An unpaired t-test was employed for the analysis of the significant differences between MDF-Ti and the control in the results for each test. RESULTS. Wear resistance and plaque adherence of MDF-Ti similar to those of CP-Ti (P>.05) were indicated. MDF-Ti exhibited significantly larger volume loss than CP-Ti in all conditions except 100/30,000 g/rpm in machinability tests (P<.05). CONCLUSION. Although the wear resistance and plaque adherence of MDF-Ti were comparable to those of controls, MDF-Ti showed better machinability than did CP-Ti. MDF-Ti could be used as a framework material for RPDs.

• 생명과학회지
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• 제22권1호
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• pp.16-24
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• 2012

Polyamine은 모든 세포의 성장과 분화에 필수적인 요소지만 그 기작은 아직 정확하게 밝혀져 있지 않다. 본 논문에서는 MCF-7세포에서 spm의 세포독성 기작을 연구하였다. MTT assay 결과 저농도의 spm (<10 ${\mu}M$) 처리시 cell viability가 증가하는 반면 고농도의 spm 처리시 처리 시간과 처리 농도에 의존적으로 감소되었으며, 이는 고농도의 spm이 MCF-7 cell에 cytotoxic한 효과를 가지고 있는 것으로 사료된다. Cell cycle 분석 결과 spm 농도에 의존적으로 sub-G1 단계의 세포 양이 증가하는 것으로 나타났으며, 이는 spm이 세포분열을 억제함으로써 세포사를 유발하는 것으로 생각된다. 또한 고농도의 spm 처리 후 2시간이 지나자 cell 표면이 움츠려 들며 rounding되기 시작하여 하루가 지난 후 거의 모든 cell이 culture dish 에서 떨어진 것을 관찰할 수 있었다. 이는 spm이 세포부착에 관여하여 세포사를 유발하는 것이라 생각되며, 세포부착을 조절하는 Integrin ${\beta}1$은 저농도의 spm에선 별다른 차이를 보이지 않다가 농도가 높아질수록 조금씩 감소하였으며, cytoskeletal protein인 actin은 농도의존적으로 감소하였다. 반면 adhesion protein인 FAK는 저농도의 spm 처리시에도 급격히 감소하였다. 이는 spm이 adhesion 및 cytoskeletal proteins의 발현을 억제하는 것으로 보이며, 특히 Integrin ${\beta}1$과 actin에 비해 FAK에 더 많은 영향을 끼치는 것으로 사료된다. 단백질들의 세포막상의 분포에 관한 연구에서, membrane 상에 위치하던 Integrin ${\beta}1$은 10 ${\mu}M$의 spm 처리시 세포 내로 약간의 위치변동이 일어났으나 그 양에는 크게 차이가 없었으며, 반면에 actin은 위치상엔 큰 변화가 일어나지는 않았지만 농도에 따라 크게 감소하는 것으로 나타났다. 세포이동과 형태조절에서 중추적인 역할을 하는 FAK는 세포막 안쪽에 위치하고 있다가 spm 처리시 세포 가운데로 이동하는 모습이 관찰되었으며 그 양도 크게 감소하였다. 이상의 실험에서 세포 내 spm의 변화는 MCF-7 cell의 adhesion protein인 Integrin ${\beta}1$과 FAK, 그리고 cytoskeletal protein인 actin의 발현을 조절하여 cell attachment를 억제함으로써 세포분열과 생장을 억제하는 것으로 분석된다.

• 치위생과학회지
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• 제8권4호
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• pp.367-373
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• 2008

천연물 황금으로부터 여러 유기용매 추출물을 얻어 치아우식증 원인균인 S. mutans 에 대한 항균활성, 배지 내 환경변화, 그리고 부착억제에 대해 알아보았다. 1. 구강 질병인 치아우식증의 대표적 원인균 S. mutans에 대한 황금 ethyl acetate 추출물 (IPK-3)의 최소억제농도는 125 mg/ml 이었다. 2. 황금 IPK-3 추출물 50 mg/ml의 농도로 S. mutans의 배지 내 투여하였을 때 균의 생장 량과 최대 생장시간은 대조군보다 지연되었다. 3. 황금 IPK-3 추출물 50 mg/ml의 농도로 S. mutans의 배지 내 투여하였을 때, pH 변화는 대조군은 18시간에서 pH 5.63으로 급격한 변화를 보였으며 황금 IPK-3 추출물이 50 mg/ml의 배지에서는 6.50이상을 유지하여 pH가 변화가 없었다. 4. 황금 IPK-3 추출물을 첨가한 배지 내 탄수화물, 단백질 및 균체 외 다당류의 변화는 대조군에 비해 매우 낮게 생산되었다. 5. 균체를 형광염료(DAPI)로 염색하여 S-HA 부착억제을 확인한 결과, 대조군은 시간이 경과함에 따라 S.mutans의 hydroxyapatite(HA)에 부착 정도가 증가되었으나, 황금 IPK-3 추출물이 첨가된 시험군에서는 S-HA에 균의 부착이 매우 적었다. 이같이 황금의 IPK-3 (ethyl acetate 추출물)이 치아우식증의 원인균인 S. mutans 에 대한 항균활성효과 뿐만아니라 hydroxyapatite에 부착 억제 효과도 있었다.

• 한국미생물·생명공학회지
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• 제48권3호
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• pp.276-286
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• 2020

Probiotics are live microorganisms that, when administered in adequate amounts, confer health benefits to the host. This study was conducted for the isolation of potential lactic acid bacteria (LAB) with probiotic properties from goat milk and yogurt. Several tests were conducted in vitro using the standard procedures for evaluating the inhibitory spectra of LAB against pathogenic bacteria; tolerance to NaCl, bile salt, and phenol; hemolytic, milk coagulation, and bile salt hydrolase activities; gastrointestinal transit tolerance; adhesion properties; and antibiotic susceptibility. Among 40 LAB strains screened according to culture characteristics, five isolates exhibited antagonistic properties. Three were identified as Pediococcus acidilactici, and two were identified as Enterococcus faecium, exploiting 16S rRNA gene sequencing. All the isolates succeeded in the gastrointestinal transit tolerance assay and successively colonized mucosal epithelial cells. Based on the results of these in vitro assays, both P. acidilactici and E. faecium can be considered as potential probiotic candidates.