• Tuberculosis and Respiratory Diseases
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• v.61 no.4
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• pp.374-383
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• 2006

Background: Ethyl pyruvate (EP) is a derivative of pyruvate that has recently been identified by both various in vitro and in vivo studies to have antioxidant and anti-inflammatory effects. The aim of this study was to determine the effect of EP on lipopolysaccharide (LPS)-induced acute lung injury (ALI). Methods: 5 weeks old, male BALB/c mice were used. ALI was induced by an intratracheal instillation of LPS 0.5mg/Kg/$50{\mu}L$ of saline. The mice were divided into the control, LPS, EP+LPS, and LPS+EP groups. In the control group, balanced salt solution was injected intraperitoneally 30 minutes before or 9 hours after the intratracheal instillation of saline. In the LPS group, a balanced salt solution was also injected intraperitoneally 30 minutes before or 9 hours after instillation the LPS. In the EP+LPS group, 40mg/Kg of EP was injected 30 minutes before LPS instillation. In the LPS+EP group, 40mg/Kg of EP was injected 9 hours after LPS instillation. The TNF-$\alpha$ and IL-6 concentrations in the bronchoalveolar lavage fluid (BALF), and that of NF-$\kappa$B in the lung tissue were measured in the control, LPS and EP+LPS groups at 6 hours after instillation of saline or LPS, and the ALI score and myeloperoxidase (MPO) activity were measured in all four groups 24 and 48 hours after LPS instillation, respectively. Results: The TNF-$\alpha$ and IL-6 concentrations were significantly lower in the EP+LPS group than in the LPS group (p<0.05). The changes in the concentration of these inflammatory cytokines were strongly correlated with that of NF-$\kappa$B (p<0.01). The ALI scores were significantly lower in the EP+LPS and LPS+EP groups compared with the LPS group (p<0.05). In the EP+LPS group, the MPO activity was significantly lower than the LPS group (p=0.019). Conclusion: EP, either administered before or after LPS instillation, has protective effects against the pathogenesis of LPS-induced ALI. EP has potential theurapeutic effects on LPS-induced ALI.

• Tuberculosis and Respiratory Diseases
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• v.53 no.5
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• pp.485-496
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• 2002

Background : Nonsteroidal anti-inflammatory drugs (NSAIDs) are useful in the chemoprevention of colon cancers. Continuous NSAID use results in a 40% to 50% reduction in the relative risk of colorectal cancer. The precise mechanism by which NSAIDs prevent and/or cause the regression of colorectal tumors is not known. Some investigators have reported that certain NSAIDs induce apoptosis and alter the expression of the cell cycle regulatory genes in some carcinoma cells when administered at a relatively high concentration. However, the possibility of NSAIDs application as chemopreventive agents in lung cancers remains to be elucidated. To address this question, the human lung cancer cell line NCI-H1299 was used to investigate whether or not NSAIDs might induce the apoptotic death of NCI-H1299 cells. Methods : A viability test was carried out using a MTT assay. Apoptosis was measured by flow cytometric analysis and unclear staining(DAPI). The talytic activity of the caspase family was measured by the fluirigenic cleavage of biosubstrates. To define the mechanical basis of apoptosis, western blot was performed to analyze the expression of the death substrates(PARP and ICAD). Results : NaSaL significantly decreased the viability of the NCI-H1299 cells, which was revealed as apoptosis characterized by an increase in the $subG_0/G_1$ population and unclear fragmentation. The catalytic activity of caspase-3 protease began to increase after 24 Hr and reached a peak 30 Hr after treatment with 10 mM NaSaL. In contrast, caspase-6, 8, and 9 proteases did not have a significantly altered enzymatic activity. Consistent with activation of caspase-3 protease, NaSaL induced the cleavage of the protease biosubstrate. Conclusion : NaSaL induces the apoptotic death of NCI-H1299 human lung cancer cells via the activation of caspase-3 protease.

• Clinical and Experimental Pediatrics
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• v.48 no.8
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• pp.839-845
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• 2005

Purpose : Neck masses, in pediatric population, derive from a multitude of congenital, inflammatory, or neoplastic diseases. The majority of these masses represent benign conditions. However, thorough clinical evaluation is required to rule out malignant diseases. We evaluated the causes, clinical characteristics and outcomes of children with neck masses who underwent tissue biopsy. Methods : A total of 28 medical records of children with neck mass who underwent tissue biopsy at Chungnam National University Hospital, from January 2000 to March 2004 were retrospectively analyzed. The methods of biopsy were ultrasonography guided core biopsy(CB), fine needle aspiration biopsy(FNAB) and excisional biopsy. Results : Out of 28 patients, half were boys. The most common location of the mass was the posterior cervical area(N=19, 67.9%). Laboratory findings of peripheral blood and serologic studies were nonspecific. In 25(89.3%) cases, CB or FNAB was initially performed for neck masses. Among them 10 cases(40%) were reactive hyperplasia, 8(32%) inflammatory granulation tissues, 4(16%) necrotizing lymphadenitis, and 3(12%) acute suppurative inflammations. Initially, excisional biopsy was performed for diagnosis in 3(10.7%) cases. Diagnosis of these cases was thyroglossal duct cyst, dermoid cyst and lymphoblastic lymphoma, respectively. Conclusion : Most neck masses in children were benign. CB and FNAB were safe methods for tissue sampling, without need for general anesthesia.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.161-171
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• 1999

Background: Interleukin-12 (IL-12) can induce antitumor effects in vivo. This antitumor effect is associated with T cell infiltration but the effect of IL-12 on the steps of T cell migration into the tumor tissue has not been fully elucidated. This study focused on the effect of IL-12 on the tumor growth and the metastasis and on the expression of E-selectin, an adhesion molecule which is activated endothelial specific in its expression. In addition, we studied whether the expression of E-selectin is associated with the TNF-$\alpha$, a cytokine that its production is increased by IL-12 and has functions inducing a variety of adhesion molecules. Methods: Mice of C57BL/6 strain were injected with Lewis lung cancer cells followed by either IL-12, TNF-$\alpha$, or normal saline by intraperitoneal route. Twenty eight days after tumor cell inoculation, metastatic nodules of lung were enumerated and immunohistochemical staining of the subcutaneous tumors were performed with monoclonal antibodies to CD4, CD8, CD16, and E-selectin. In IL-12 treated mice, the subcutaneously implanted Lewis lung tumors were decreased in size and the metastases were also decreased in number compared to control mice. On tumor tissues, increased infiltration of CD4+, CD8+, and CD16+ cells were oberved in IL-12 treated mice compared to control mice. In control mice, E-selectin was absent on tumor vessels, but the expression of E-selectin was increased on tumor vessels of IL-12 treated mice. Administration of TNF-$\alpha$ increased not only the expression of E-selectin but also infiltrations of CD4+, CD8+, and CD16+ cells on tumor tissues. Conclusions: These results demonstrate that IL-12 inhibits tumor growth and metastases through infiltrations of inflammatory cells in mouse model of Lewis lung carcinoma and E-selectin may playa role in inflammatory cell recruitment on tumor tissue following IL-12 administration. Also, TNF-$\alpha$ may have a role as a mediator responsible for the IL-12 induced expression of E-selectin.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.172-183
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• 1999

Background: Nitric oxide is a short-lived effector molecule derived from L-arginine by the nitric oxide synthase(NOS). Nitric oxide plays a role in a number of physiologic and pathophysiologic functions including host defense, edema formation, and regulation of smooth muscle tone. Some kinds of cells including macrophage are known to produce large quantities of nitric oxide in response to inflammatory stimuli such as interleukin-$1\beta$(IL-$1\beta$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), interferon-$\gamma$(IFN-$\gamma$) and lipopolysaccharide(LPS). Reactive oxygen species are also known to be important in the pathogenesis of acute cell and tissue injury such as acute lung injury model Methods: Using the RA W264.7 cells, we have examined the ability of oxidant hydrogen peroxide($H_2O_2$) to stimulate nitric oxide production and inducible NOS mRNA expression. Also, we have examined the effects of NOS inhibitors and antioxidants on $H_2O_2$ induced nitric oxide production. Results: Stimulation of RAW264.7 cells with combinations of 100 ng/ml IL-$1\beta$, 100 ng/ml TNF-$\alpha$, and 100 U/ml IFN-$\gamma$ or 100 U/ml IFN-$\gamma$ and $1{\mu}g/ml$ LPS induced the synthesis of nitric oxide as measured by the oxidation products nitrite($NO_2^-$) and nitrate($NO_3^-$). Addition of $250 {\mu}M-2$ mM $H_2O_2$ to the cytokines significantly augmented the synthesis of $NO_2^-$ and $NO_3^-$(p<0.05). When cells were incubated with increasing concentrations of $H_2O_2$ in the presence of IL-$1\beta$, TNF-$\alpha$ and IFN-$\gamma$ at constant level, the synthesis of $NO_2^-$ and $NO_3^-$ was dose-dependently increased(p<0.05). $N^G$-nitro-L-arginine methyl ester(L-NAME), dose dependently, significantly inhibited the formation of $NO_2^-$ and $NO_3^-$ in cells stimulated with LPS, IFN-$\gamma$ and $H_2O_2$ at constant level(p<0.05). Catalase significantly inhibited the $H_2O_2$-induced augmentation of cytokine-induced $NO_2^-$ and $NO_3^-$ formation(p<0.05). But, boiled catalase did not produce a significant inhibition in comparison with the native enzyme. Another antioxidant 2-mercaptoethanol and orthophenanthroline dose-dependently suppressed $NO_2^-$ and $NO_3^-$ synthesis(p<0.05). Northern blotting demonstrated that H:02 synergistically stimulated the cytokine-induced iNOS mRNA expression in RA W264.7. Conclusion: These results suggest that $H_2O_2$ contributes to inflammatory process by augmenting the iNOS expression and nitric oxide synthesis induced by cytokines.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.462-474
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• 1994

Background : In acute lung injury, activated neutrophils play an important role in tissue damage. For neutrophils to participate in lung inflammation, chemotactic factors released from mononuclear phagocytes are needed to bring these cells to the local site of inflammation, with interleukin-8 (IL-8) being one of the most specific and important chemotactic factors for neutrophils. IL-8 also induces the expression of adhesion molecules and activates neutrophils to release various inflammatory mediators. Lipopolysaccharide(LPS) is one of the most important causes of adult respiratory distress syndrome and can cause release of many inflammatory cytokines including IL-8 leading to acute lung injury. But little is known about the regulatory mechanism of LPS-induced IL-8 gene expression in mononuclear phagocytes. Method : Human alveolar macrophages(HAM) and peripleral blood monocytes(PBMC) were isolated from healthy volunteers. Time and dose relationship of LPS-induced IL-8 mRNA expression was observed by Northern blot analysis. To evaluate the regulatory mechanism of LPS-induced IL-8 gene expression, pretreatment of actinomycin D(AD, $5{\mu}g/ml$) and cycloheximide(CHX, $5{\mu}g/ml$) was done and Northern blot analysis for IL-8 mRNA and ELISA for immunoreactive IL-8 protein in culture supernatant were performed. Results : 1) In HAM, dose and time dependent LPS-induced IL-8 mRNA expression was observed with peak mRNA level at 8 hours post-stimulation. 2) In PBMC, dose and time dependent LPS-induced IL-8 mRNA expression was also observed with peak mRNA level at 4 hours post-stimulation. 3) AD decreased expression of LPS-induced IL-8 gene expression at both mRNAand protein levels in both types of cells. 4) CHX decreased expression of LPS-induced IL-8 gene expression at protein level in both cell types but in HAM, superinduction of IL-8 mRNA was observed while decreased expression of IL-8 mRNA was observed in PBMC. Conclusion : Time and dose dependent LPS-induced IL-8 gene expression was observed in mononuclear phagocytes which is at least partly regulated pretranslationally. LPS-induced IL-8 mRNA expression in HAM needs no de novo protein synthesis and may be under the control of a labile repressor protein while de novo protein synthesis may be needed in PBMC.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.475-483
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• 1994

Background: N-acetylcysteine(ACE) is used both orally and intravenously in a variety of experimental pathologies resembling human disease states which exhibit endothelial toxicity as a result of oxidative stress, including acute pulmonary oxygen toxicity, septicemia and endotoxin shock. Despite these observations in vivo, it is not certain how this thiol drug produces its protective effects. ACE is a cysteine derivative which is able to direct1y react with oxygen radicals and may also act as a cysteine and glutathione(GSH) precursor following deacetylation. In this paper, we tried to know whether the therapeutic doses of ACE can modify the inflammatory function of the neutrophils and can increase the glutathione level of plasma in chronic obstructive pulmonary disease(COPD) patients. In addition, the effect of ACE to the purified neutrophil in terms of superoxide release and glutathione synthesis were observed. Method: Firstly, we gave 600mg of ACE for seven days and compare the release of superoxide, luminol-enhanced chemiluminescence from the neutrophils, neutrophil chemotaxis, and plasma GSH levels before and after ACE treatment in COPD patients. Secondly, we observed the dose dependent effect of ACE to the purified neutrophil's superoxide release and GSH levels in vitro. Results: 1) Usual oral therapeutic doses(600mg per day) of ACE for seven days did affect neither on the neutrophil's superoxide release, chemiluminescence, chemotaxis, nor on the plasma GSH concentration in the COPD patients. 2) ACE decreases the purified neutrophil's superoxide release and increase the GSH production in dose dependent fashion in vitro. Conclusion: Despite the fact that oral ACE treatment did not affect on the neutrophil's inflammatory function and plasma GSH concentration in COPD patients in usual therapeutic doses, it decreases the superoxide release and increases the GSH production from the isolated neutrophils in high molar concentrations. These findings suggest that to obtain an antioxidative effects of ACE, it might be needed to increase the daily dosage of ACE or therapeutic duration or change the route of adminisration in COPD patients.

• Tuberculosis and Respiratory Diseases
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• v.53 no.6
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• pp.619-634
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• 2002

Background : Many inflammatory mediators and collagenases are involved in the pathogenesis of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The increase of matrix metalloproteinase-9 (MMP-9, gelatinase-B) produced mainly by inflammatory cells was reported in many ALI models and connective tissue cells. In this study, the expression of MMP-9 in ventilator-induced lung injury (VILI) model and the effects of matrix metalloproteinase inhibitor (MMPI) on VILI were investigated. Methods : Eighteen Sprague-Dawley rats were divided into three groups: low tidal Volume (LVT, 7mL/Kg tidal volume, 3 $cmH_2O$ PEEP, 40/min), high tidal volume (HVT, 30mL/Kg tidal volume, no PEEP, 40/min) and high tidal volume with MMPI (HVT+MMPI) groups. Mechanical ventilation was performed in room air for 2 hours. The 20 mg/Kg of CMT-3 (chemically modified tetracycline-3, 6-demethyl 6-deoxy 4-dedimethylamino tetracycline) was gavaged as MMPI from three days before mechanical ventilation. The degree of lung injury was measured with wet-to-dry weight ratio and acute lung injury score. Expression of MMP-9 was studied by immunohistochemical stain with a mouse monoclonal anti-rat MMP-9 $IgG_1$. Results : In the LVT, HVT and HVT+MMPI groups, the wet-to-dry weight ratio was $4.70{\pm}0.14$, $6.82{\pm}1.28$ and $4.92{\pm}0.98$, respectively. In the HVT group, the ratio was significantly higher than other groups (p<0.05). Acute lung injury score measured by five-point scale was $3.25{\pm}1.17$, $12.83{\pm}1.17$ and $4.67{\pm}0.52$, respectively. The HVT group was significantly damaged by VILI and MMPI protects injuries by mechanical ventilation (p<0.05). Expression of MMP-9 measured by four-point scale was $3.33{\pm}2.07$, $12.17{\pm}2.79$ and $3.60{\pm}1.95$, respectively, which were significantly higher in the HVT group (p<0.05). Conclusion : VILI increases significantly the expression of MMP-9 and MMPI prevents lung injury induced by mechanical ventilation through the inhibition of MMP-9.

• Journal of Life Science
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• v.29 no.12
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• pp.1371-1377
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• 2019

Oxidative stress induced by the over-production of reactive oxygen species (ROS) in the brain is the most common cause of neurodegenerative diseases such as Alzheimer's. In the present study, we investigated the protective effects of flavonoids and their glycosides, namely kaempferol, kaempferol-3-O-glucoside, quercetin, and quercetin-3-β-D-glucoside, against H₂O₂-induced oxidative stress in the C6 glial cells. The H₂O₂-treated glial cells exhibited decreased cell viability and increased ROS production when compared with normal cells. However, cells treated with each of the four flavonoids/glycosides demonstrated significantly increased viability and suppressed ROS production when compared with the H₂O₂-treated control group. These results indicate that flavonoids/glycosides attenuate oxidative stress induced by H₂O₂ in C6 glial cells. To confirm the protective molecular mechanisms, we measured pro-inflammatory factors such as inducible nitric oxide synthase, cyclooxygenase-2, and interleukin-1β. H₂O₂ treatment was seen to elevate these factors and decrease IκB-α in the C6 glial cells, while the flavonoids/glycosides induced a down-regulation of the pro-inflammatory factors and increased IκB-α, indicating a neuroprotective effects through attenuation of the inflammation. In particular, quercetin and its glycoside showed a higher neuroprotective effect than the kaempferol treatments. These results suggest that these flavonoids and their glycosides could be promising therapeutic agents for neurodegenerative diseases via the attenuation of oxidative stress.

• Tuberculosis and Respiratory Diseases
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• v.39 no.4
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• pp.325-333
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• 1992

Background and Methods: To study the effects of corticosteroid (CS) on the parquat (PQ) induced lung injury, serial cellular analyses of bronchoalveolar lavage (BAL) fluid were done with simultaneous histopathologic examination after intraperitoneal injection of PQ on the rats. The sacrificed animals were divided into three groups; control group, PQ group received intraperitoneal injection of 20 mg/kg of PQ, and CS group received daily injection of Methylprednisolone sodium succinate (20 mg/kg) in addition to PQ. Results: 1) Cellular analyses of BAL fluid: The total cell count in the BAL fluid were increased gradually from 6 hours after PQ administration (p<0.05), and was decreased at 3 days after (p<0.05). These changes were mainly due to the effects of PQ on the neutrophil influx (p<0.05). But, the number of macrophage and the percentage of lymphocyte in total cells showed little changes. The CS administration showed the suppression of neutrophil influx in the BAL fluid (p<0.05), but could not show any significant effect on the number of macrophage and lymphocyte. 2) Histopathologic examination: In the PQ group, inflammatory changes especially with prominant neutrophil infiltration were gradually progressed over time. Those changes were found in both alveolar space and interstitium with resultant alveolar structural changes, but subsided from 3 days after. CS suppressed inflammatory changes in the alvolar space and interstitium, especially with decreased infiltration of neutrophil. Conclusion: CS suppressed neutrophil infiltration in the acute lung injury induced by PQ, those findings were ascertained by serial cellular analyses of BAL fluid and histopathologic examination.