• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.887-897
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• 2000

Background : Since the exact pathogenesis of sepsis-induced ARDS has not been elucidated, the mechanisms of enhanced neutrophilic respiratory burst were probed in endotoxin primed neutrophils associated with the roles of phospholipase A2(PLA2), platelet activating factor(PAF) and apoptosis. Methods : In isolated fresh human neutrophils, effects of the inhibition of PLA2 and PAF on the apoptosis were examined by the method of Annexin-FITC/dual PIflow cytometry. The roles of PLA2 and PAF on the neutrophilic respiratory burst were also examined by measuring oxidant generation in cytochrome-c reduction assay. Activities of the PLA2 and lysoPAF acetyltransferase (lysoPAF AT) of the neutrophils were determined to understand the effect of endotoxin on these enzymatic activities which may be related to the neutrophilic respiratory burst and apoptosis. In addition, the role roles of PLA2 and PAF in neutrophilic adhesion to bovine endothelial cells were examined in vitro by neutrophil adhesion assay. To investigate the effect of oxidants on pulmonary surfactant, cytochemical ultrastructural microscopy was performed. To inhibit PLA2 and PAF, non-specific PLA2 inhibitor mepacrine (100 nM) and WEB 2086 (100 nM) or ketotifen fumarate (10 ${\mu}g$/ml) were used respectively in all in vitro experimental sets. WEB 2086 is PAF receptor antagonist, and ketotifen fumarate is a lyso PAF AT inhibitor. Results: The mapacrine treatment, provided and the endotoxin (ETX) treatment, resulted in increased apoptosis of neutrophils (p<0.001) while treatments of WEB 2086 and ketotifen did not. The inhibition of PLA2 and PAF decreased (p<0.001) production of oxidants from PMA-stimulated neutrophils. While endotoxin increased the PLA2 activity of neutrophils (p<0.01), mepacrine supressed (p<0.001) the activity, provided after treatment of ETX. The lyso PAF actyltransferase activity (lyso PAF AT) increased (p<0.01) after treatment of ETX. In contrast, mepacrine, WEB 2086 and ketotifen showed a tendency of decreasing the activity after treatment of ETX. The treatment of ETX incresed (p<0.001) neutrophil adhesion to endothelial cells, which was reversed by inhibition of PLA2 and PAF (p<0.01). The binding of oxidants to pu1monary surfactant was identified histologically. Conclusions : The enhanced neutrophilic respiratory burst by ETX plays a pivotal role in the pathogenesis of ARDS in terms of oxidayive oxidative stress. Increased production of oxidants from neutrophils is mediated by the activations of PLA2 and lyso PAF AT.

• Implantology
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• v.18 no.2
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• pp.120-138
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• 2014

Purpose: The purpose of this study was to review the outcomes of a series of studies on tissue regeneration conducted in multiple institutions including the Department of Periodontology, College of Dentistry, Yonsei University. Materials and Methods: Studies were performed divided into the following three subjects; 1) Development of three-dimensional nano-hydroxyapatite (n-HA) scaffold for facilitating drug release and cell adhesion. 2) Synergistic effects of bone marrow-derived mesenchymal stem cells (BMMSC) application simultaneously with platelet-rich plasma (PRP) on HA scaffolds. 3) The efficacy of silk scaffolds coated with n-HA. Also, all results were analyzed by subjects. Results: Hollow hydroxyapatite spherical granules were found to be a useful tool for the drug release and avidin-biotin binding system for cell attachment. Also, BMMSC simultaneously with PRP applied in an animal bone defect model was seen to be more synergistic than in the control group. But, the efficacy of periodontal ligament cells and dental pulp cells with silk scaffolds could not be confirmed in the initial phase of bone healing. Conclusion: The ideal combination of three elements of tissue engineering-scaffolds, cells and signaling molecules could be substantiated due to further investigations with the potentials and limitations of the suggested list of studies.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.539-544
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• 2005

Purpose : The aim of this study was to investigate the pathophysiologic role of serum E-selectin, vascular endothelial growth factor(VEGF)-induced cell adhesion mollecule in Kawasaki disease(KD) and to look for the evidence of direct relationship between the plasma levels of soluble E-selectin and the incidence of coronary artery lesion(CAL). Methods : Changes in plasma levels of sE-selectin(n=98) over time were measured by enzyme-linked immunosorbent assay(ELISA) in 23 patients with acute KD and 25 age-matched febrile children. Results : Compared with control values, the peak levels of plasma sE-selectin were significantly elevated($mean{\pm}S.E$. : $22.89{\pm}12.53ng/mL$ vs $10.65{\pm}3.42ng/mL$, P=0.01) in KD. 5 patients with CAL, plasma sE-selectin levels before treatment were higher than in 18 patients without CAL($mean{\pm}S.E$. : $39.43{\pm}15.08ng/mL$ and $19.00{\pm}8.32ng/mL$, respectively; P=0.01). Plasma sE-selectin declined rapidly in the majority of KD patients regardless of the presence of CAL. Plasma sE-selectin levels after treatment and convalesent period were similar in KD patients with and without CAL. The plasma levels sE-selectin were correlated with those of white blood cell count(r=0.299, P<0.05), CRP(r=0.430, P<0.05), serum albumin(r=-0.483, P<0.05), serum protein(r=-0.502, P<0.05) and hemoglobin(r=-0.372, P<0.05) not with those of ESR, platelet, or duration of fever. There were significant differences in the initial level of serum sE-selectin between KD with and without CAL($mean{\pm}S.E$. : $39.44{\pm}15.08ng/mL$ vs. $19.00{\pm}17.18ng/mL$) in multivariated linear tests. Conclusion : Plasma sE-selectin levels were significantly higher in KD than in other febrile illness. Higher plamsa levels of sE-selectin may have potential as a predictor of CAL in patients with KD.

• Tuberculosis and Respiratory Diseases
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• v.50 no.5
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• pp.557-567
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• 2001

Background : Tumor angiogenesis is required for tumor growth and metastasis. In this study, we investigated the correlation between the intensity of angiogenesis and stage, nodal status, histologic type, metastasis and survival rate of non-small cell lung cancer. Method : Formalin fixed, paraffin embedded surgical specimens of 45 patients who had surgically resected primary non-small cell lung cancers without pre or post operative adjuvant chemotherapy or radiotherapy were examined. The microvessel count(MVC) was demonstrated by immunohistochemical staining for CD31(platelet endothelial cell adhesion molecule, PECAM). Results : Microvessel counts(MVCs) in stage IIIA and IIIB were higher than in stage I and II(p<0.05). The MVC in patients with lymph node metastasis was higher than that in patients without lymph node metastasis, although the difference was not statistically significant(p>0.05). However, in adenocarcinoma, the MVC in patients with lymph node metastasis was significantly higher than that seen in patients without lymph node metastasis(p<0.05). The MVC in adenocarcinoma was higher than that in squamous cell carcinoma(p<0.05). The difference between the MVCs of adenocarcinoma and squamous cell carcinoma was not statistically significant in stage I and II or N0 stage(p>0.05). However, in stage IIIA and IIIB or N1~3 stage, the MVC in adenocarcinoma was higher than that in squamous cell carcinoma(p<0.05). MVC was more increased when metastasis developed within 12 months. In the same histologic type and stage, the duration of survival time in patients with high MVC was shorter than in patients with low MVC, however the difference was not statistically significant(p>0.05). The survival rate in patients with high MVCs was lower than that in patients with low MVCs(P<0.05). Conclusion : In non-small cell lung cancer, MVC correlated relatively well with pathologic stage, nodal status(limited in patients with adenocarcinoma), histologic type, postoperative metastasis and survival rate. However, in the same histologic type and stage, MVC was not significantly related to the duration of survival. Therefore the assessment of the intensity of angiogenesis in non-small cell lung cancer may be helpful in predicting prognosis and in selecting patients for systemic adjuvant therapy of potential metastasis according to the results.

• 한국유가공학회:학술대회논문집
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• 2007.09a
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• pp.49-58
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• 2007

Inflammatory process leads to the well-known mucosal damage and therefore a further disturbance of the epithelial barrier function, resulting abnormal intestinal wall function, even further accelerating the inflammatory process[1]. Despite of the records, etiology and pathogenesis of IBD remain rather unclear. There are many studies over the past couple of years have led to great advanced in understanding the inflammatory bowel disease(IBD) and their underlying pathophysiologic mechanisms. From the current understanding, it is likely that chronic inflammation in IBD is due to aggressive cellular immune responses including increased serum concentrations of different cytokines. Therefore, targeted molecules can be specifically eliminated in their expression directly on the transcriptional level. Interesting therapeutic trials are expected against adhesion molecules and pro-inflammatory cytokines such as TNF-${\alpha}$. The future development of immune therapies in IBD therefore holds great promises for better treatment modalities of IBD but will also open important new insights into a further understanding of inflammation pathophysiology. Treatment of cytokine inhibitors such as Immunex(Enbrel) and J&J/Centocor(Remicade) which are mouse-derived monoclonal antibodies have been shown in several studies to modulate the symptoms of patients, however, theses TNF inhibitors also have an adverse effect immune-related problems and also are costly and must be administered by injection. Because of the eventual development of unwanted side effects, these two products are used in only a select patient population. The present study was performed to elucidate the ability of TNF-${\alpha}$ antibodies produced in sheep colostrums to neutralize TNF-${\alpha}$ action in a cell-based bioassay and in a small animal model of intestinal inflammation. In vitro study, inhibitory effect of anti-TNF-${\alpha}$ antibody from the sheep was determined by cell bioassay. The antibody from the sheep at 1 in 10,000 dilution was able to completely inhibit TNF-${\alpha}$ activity in the cell bioassay. The antibodies from the same sheep, but different milkings, exhibited some variability in inhibition of TNF-${\alpha}$ activity, but were all greater than the control sample. In vivo study, the degree of inflammation was severe to experiment, despite of the initial pilot trial, main trial 1 was unable to figure out of any effect of antibody to reduce the impact of PAF and LPS. Main rat trial 2 resulted no significant symptoms like characteristic acute diarrhea and weight loss of colitis. This study suggested that colostrums from sheep immunized against TNF-${\alpha}$ significantly inhibited TNF-${\alpha}$ bioactivity in the cell based assay. And the higher than anticipated variability in the two animal models precluded assessment of the ability of antibody to prevent TNF-${\alpha}$ induced intestinal damage in the intact animal. Further study will require to find out an alternative animal model, which is more acceptable to test anti-TNF-${\alpha}$ IgA therapy for reducing the impact of inflammation on gut dysfunction. And subsequent pre-clinical and clinical testing also need generation of more antibody as current supplies are low.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1265-1276
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• 1998

Background : Nitric oxide(NO) is an endogenously produced free radical that plays an important role in regulating vascular tone, inhibition of platelet aggregation and white blood cell adhesion to endothelial cells, and host defense against infection. The highly reactive nature of NO with oxygen radicals suggests that it may either promote or reduce oxidant-induced cell injury in several biological pathways. Oxidant injury and interactions between pulmonary vascular endothelium and leukocytes are important in the pathogenesis of acute lung injury, including acute respiratory distress syndrome(ARDS). In ARDS, therapeutic administration of NO is a clinical condition providing exogenous NO in oxidant-induced endothelial injury. The role of exogenous NO from NO donor or the suppression of endogenous NO production was evaluated in oxidant-induced endothelial injury. Method : The oxidant injury in cultured rat lung microvascular endothelial cells(RLMVC) was induced by hydrogen peroxide generated from glucose oxidase(GO). Cell injury was evaluated by $^{51}$chromium($^{51}Cr$) release technique. NO donor, such as S-nitroso-N-acetylpenicillamine(SNAP) or sodium nitroprusside(SNP), was added to the endothelial cells as a source of exogenous NO. Endogenous production of NO was suppressed with N-monomethyl-L-arginine(L-NMMA) which is an NO synthase inhibitor. L-NMMA was also used in increased endogenous NO production induced by combined stimulation with interferon-$\gamma$(INF-$\gamma$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), and lipopolysaccharide(LPS). NO generation from NO donor or from the endothelial cells was evaluated by measuring nitrite concentration. Result : $^{51}Cr$ release was $8.7{\pm}0.5%$ in GO 5 mU/ml, $14.4{\pm}2.9%$ in GO 10 mU/ml, $32.3{\pm}2.9%$ in GO 15 mU/ml, $55.5{\pm}0.3%$ in GO 20 mU/ml and $67.8{\pm}0.9%$ in GO 30 mU/ml ; it was significantly increased in GO 15 mU/ml or higher concentrations when compared with $9.6{\pm}0.7%$ in control(p < 0.05; n=6). L-NMMA(0.5 mM) did not affect the $^{51}Cr$ release by GO. Nitrite concentration was increased to $3.9{\pm}0.3\;{\mu}M$ in culture media of RLMVC treated with INF-$\gamma$ (500 U/ml), TNF-$\alpha$(150 U/ml) and LPS($1\;{\mu}g/ml$) for 24 hours ; it was significantly suppressed by the addition of L-NMMA. The presence of L-NMMA did not affect $^{51}Cr$ release induced by GO in RLMVC pretreated with INF-$\gamma$, TNF-$\alpha$ and LPS. The increase of $^{51}Cr$ release with GO(20 mU/ml) was prevented completely by adding 100 ${\mu}M$ SNAP. But the add of SNP, potassium ferrocyanate or potassium ferricyanate did not protect the oxidant injury. Nitrite accumulation was $23{\pm}1.0\;{\mu}M$ from 100 ${\mu}M$ SNAP at 4 hours in phenol red free Hanks' balanced salt solution. But nitrite was not detectable from SNP upto 1 mM The presence of SNAP did not affect the time dependent generation of hydrogen peroxide by GO in phenol red free Hanks' balanced salt solution. Conclusion : Hydrogen peroxide generated by GO causes oxidant injury in RLMVC. Exogenous NO from NO donor prevents oxidant injury, and the protective effect may be related to the ability to release NO. These results suggest that the exogenous NO may be protective on oxidant injury to the endothelium.