• Tuberculosis and Respiratory Diseases
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• 제76권2호
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• pp.66-74
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• 2014

Background: The increasing number of outpatients with multidrug-resistant (MDR) pathogens has led to a new category of pneumonia, termed healthcare-associated pneumonia (HCAP). We determined the differences in etiology and outcomes between patients with HCAP and those with community-acquired pneumonia (CAP) to clarify the risk factors for HCAP mortality. Methods: A retrospective study comparing patients with HCAP and CAP at Jeju National University Hospital. The primary outcome was 30-day mortality. Results: A total of 483 patients (208 patients HCAP, 275 patients with CAP) were evaluated. Patients with HCAP were older than those with CAP (median, 74 years; interquartile range [IQR], 65-81 vs. median, 69 years; IQR, 52-78; p<0.0001). Streptococcus pneumoniae was the major pathogen in both groups, and MDR pathogens were isolated more frequently from patients with HCAP than with CAP (18.8% vs. 4.9%, p<0.0001). Initial pneumonia severity was greater in patients with HCAP than with CAP. The total 30-day mortality rate was 9.9% and was higher in patients with HCAP based on univariate analysis (16.3% vs. 5.1%; odds ratio (OR), 3.64; 95% confidence interval (CI), 1.90-6.99; p<0.0001). After adjusting for age, sex, comorbidities, and initial severity, the association between HCAP and 30-day mortality became non-significant (OR, 1.98; 95% CI, 0.94-4.18; p=0.167). Conclusion: HCAP was a common cause of hospital admissions and was associated with a high mortality rate. This increased mortality was related primarily to age and initial clinical vital signs, rather than combination antibiotic therapy or type of pneumonia.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1621-1628
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• 2012

The agar-degrading bacterium GNUM-1 was isolated from the brown algal species Sargassum serratifolium, which was obtained from the West Sea of Korea, by using the selective artificial seawater agar plate. The cells were Gram-negative, $0.5-0.6{\mu}m$ wide and $2.0-2.5{\mu}m$ long curved rods with a single polar flagellum, forming nonpigmented, circular, smooth colonies. Cells grew at $20^{\circ}C-37^{\circ}C$, between pH 5.0 and 9.0, and at 1-10% (w/v) NaCl. The DNA G+C content of the GNUM-1 strain was 45.5 mol%. The 16S rRNA sequence of the GNUM-1 was very similar to those of Alteromonas stellipolaris LMG 21861 (99.86% sequence homology) and Alteromonas addita $R10SW13^T$(99.64% sequence homology), which led us to assign it to the genus Alteromonas. It showed positive activities for agarase, amylase, gelatinase, alkaline phosphatase, esterase (C8), lipase (C14), leucine arylamidase, valine arylamidase, ${\alpha}$-chymotrypsin, acid phosphatase, naphthol-AS-BI-phosphohydrolase, ${\alpha}$-galactosidase, ${\beta}$-galactosidase, ${\beta}$-glucosidase, catalase, and urease. It can utilize citrate, malic acid, and trisodium citrate. The major fatty acids were summed feature 3 (21.5%, comprising $C_{16:1}{\omega}7c/iso-C_{15:0}$ 2-OH) and C16:0 (15.04%). On the basis of the variations in many biochemical characteristics, GNUM-1 was considered as unique and thus was named Alteromonas sp. GNUM-1. It produced the highest agarase activity in modified ASW medium containing 0.4% sucrose, but lower activity in rich media despite superior growth, implying that agarase production is tightly regulated and repressed in a rich nutrient condition. The 30 kDa protein with agarase activity was identified by zymography, and this report serves as the very first account of such a protein in the genus Alteromonas.

• Transactions of the Korean Society of Automotive Engineers
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• 제15권1호
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• pp.64-70
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• 2007

Raising exhaust gas temperature during cold-start period is very crucial to improve emission performance of SI engines because it enhances the performance of catalyst in the early stage of engine start. In this study, control variables such as ignition timing, idle speed actuator(ISA) opening and fuel injection duration were extensively investigated to analyze variations in exhaust gas temperature and engine stability during cranking period. Experimental results showed that spark timing affected engine stability and exhaust gas temperature but the effects were small. On the other hand, shortened injection duration and increased ISA opening led to a significant increase in exhaust gas temperature. Under such conditions, increase in cranking time was also observed, showing that it becomes harder to start the engine. Based on these observations, a pseudo fuel-air ratio, defined as a ratio of fuel injection time to degree of ISA opening, was introduced to analyze the experimental results. In general, decrease in pseudo fuel-air ratio raised exhaust gas temperature with the cost of stable and fast cranking. On the contrary, an optimal range of the pseudo fuel-air ratio was found to be between 0.3 to 0.5 where higher exhaust gas temperatures can be obtained without sacrificing the engine stability.

• Korean Journal of Pharmacognosy
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• 제36권3호통권142호
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• pp.245-251
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• 2005

Phytochemical examination of the barks of Actinidia arguta led to the isolation of five flavonoids. Structures of compounds were elucidated as catechin (1), (-)-epicatechin (2), quercetin (3), $quercetin-3-O-{\beta}-D-glucopyranoside$ (4), $quercetin-3-O-{\beta}-D-galactopyranoside$ (5) by comparison with previously reported spectral evidences. To investigate the anti-oxidative effect and nitric oxide (NO) production inhibitory activity of these compounds, DPPH radical scavenging activity and nitric oxide production inhibitory activity in $IFN-{\gamma}$, LPS stimulated RAW 264.7 cell were examined. The $IC_{50}s$ were determinied as follows : $1\;$IC_{50}=26.61\;{\mu}g/ml$, $2\;IC_{50}=25.30\;{\mu}g/ml$, $3\;IC_{50}=20.41\;{\mu}g/ml$, $4\;IC_{50}=18.23\;{\mu}g/ml$ , $5\;IC_{50}=30.46\;{\mu}g/ml$, $6\;IC_{50}=28.0;{\mu}g/ml$, $7\;IC_{50}=27.24\;{\mu}/ml$. These NO production inhibitory effects were significantly different compared with the positive control, L-NMMA $(IC_{50}=20.77\;{\mu}g/ml)$, respectively. Compound $1\;(IC_{50}=6.19\;{\mu}g/ml)$, $2\;(IC_{50}=8.98\;{\mu}g/ml)$, $3\;(IC_{50}=7.30\;{\mu}g/ml)$ and $4\;(IC_{50}=7.64\;{\mu}g/ml)$ also showed potent antioxidative activities similar level to ascorbic acid $(IC_{50}=9.22\;{\mu}g/ml)$. These results suggest that barks of A. arguta have a potent anti-oxidative and anti-inflammatory activity.

• Preventive Nutrition and Food Science
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• 제2권2호
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• pp.121-128
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• 1997

this study was conducted to examine the atherogenic effect of high cholesterol diet (experimental diet) that influences changes of lipoprotein cholesterol metabolism and arterial wall. Seven NewZealand white rabbits were fed control diet, an the other 7 rabbits 2% cholesterol diet for 10 weeks. Results obtained from this study are as follows: 1) High cholesterol diet resulted in a gradual increase of plasma total cholesterol level, reaching upto 1422 mg/dl at the seventh week. 2) CETP (cholesteryl ester transfer protein) activity was significantly higher in high cholesterol group (64.9% at the 7th week) than control group (49.3% at the 7th week) during most of the experimental period except the 6th week. 3) The cholesterol supplementation induced fatty liver and a decrease of hepatic HMG-CoA reductase activities (2.1 moles vs. 0.3nmoles) compared to control group. 4) Bands of apo B-100 and apo E in plasma lipoprotein were thicker in high cholesterol-fed animals tan control animals as visualized by SDS-PAGE. 5) Oxidizability of plasma lipoproteins measured in vitro was greater in high cholesterol group tan control group, but vitamin E level higher in control group. 6) he effect of cholesterol feeding for 10 weeks also led to early fatty streaks in aortic intima. High cholesterol feeding was atherogenic to rabbits, an this seems to be mediated through elevated CETP activities that regulate plasma HDL cholesterol level and decrease an efficiency of reverse cholesterol transport in lipoprotein cholesterol metabolism. The enhanced oxidizability of plasma lipoproteins and lowered vitamin E level may also contribute to the formation of faaty streaks in aorta of cholesterol-fed rabbits.

• Journal of Applied Biological Chemistry
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• 제64권4호
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• pp.363-368
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• 2021

The fruits of tomato (Lycopersicon esculentum) were extracted with 70% aqueous methanol (MeOH) and the concentrates were partitioned into ethyl acetate (EtOAc), n-butanol (n-BuOH), and water (H₂O) fractions. The repeated silica gel (SiO₂) and octadecyl silica gel column chromatographies for the EtOAc fraction, whose activity was confirmed, led to isolation of one flavone compound. Nuclear magnetic resornance, infrarad spectroscopy, and mass spectroscopy (MS) revealed the chemical structure of the isolated compound, 5,7,3'-trihydroxy-6,4',5'-trimethoxyflavone (1). LC-MS/MS analysis determined the content level of compounds 1 in the MeOH extract to be 4.02±0.12 ㎍/mg and in the TME-10 fraction to be 0.96±0.03 ㎍/mg. Through this study, the antioxidantive capacity was confirmed by demonstrating that the L. esculentum extract and their fractions showing an increase in glutathione mean and a decrease in glutathione heterogeneity uniformly raises the intracellular glutathione level.

• Journal of Applied Biological Chemistry
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• 제64권3호
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• pp.263-268
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• 2021

7-Hydroxy-4-methylcoumarin (7H-4MC) inhibits hyaluronan production in multiple cell lines and tissue types both in vitro and in vivo. It is a commercially available drug approved for human use, called hymecromone, in European and Asian countries to prevent biliary spasms. Nevertheless, as the pharmacological efficacy of 7H-4MC has not yet been reported in macrophages, this study investigated its anti-inflammatory effects and mechanism of action using lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. LPS-induced RAW 264.7 cells were treated with various concentrations of 7H-4MC (62.5, 125, 250, and 500 μM). The application of 7H-4MC significantly reduced nitric oxide and prostaglandin E₂ production without cytotoxic effects. Additionally, 7H-4MC strongly decreased the expression of inducible nitric oxide synthase and cyclooxygenase. Furthermore, 7H-4MC reduced the production of proinflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. Finally, 7H-4MC exerted its potent anti-inflammatory actions via the upregulation of IκB-α production, which led to the inhibition of nuclear factor-κB (NF-κB) activity. These results, obtained in macrophage cell lines, suggest that 7H-4MC prevents inflammatory diseases via the NF-κB signaling pathway and that its use could be beneficial for human health. Ultimately, this is the first report describing the anti-inflammatory activity of 7H-4MC in a macrophage cell line.

• Journal of Applied Biological Chemistry
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• 제64권3호
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• pp.277-284
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• 2021

The emergence and rapid spread of the potentially fatal coronavirus disease 2019, caused due to infection by severe acute respiratory syndrome coronavirus-2, has led to worldwide interest in developing functional bioactive ingredients that act as immunomodulatory agents. In this study, we aimed to characterize Carica papaya extract and explore its potential as an immunomodulator by performing in vitro cell screening. Papaya leaf water extract (PLW) was found to significantly increase the levels of nitric oxide (NO) and prostaglandin E₂ (PGE₂) by upregulating inducible nitric oxide synthase and cyclo-oxygenase-2 activity, respectively. Additionally, PLW increased the production of tumor necrosis factor-α and interleukin 1β in RAW 264.7 cells. Furthermore, PLW activated the expression of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) but not that of p38 mitogen-activated protein kinase. These results indicate that PLW increased the production of NO, PGE₂, and pro-inflammatory cytokines by activating the JNK and ERK pathways in macrophages, thus demonstrating immunomodulatory properties. Finally, high-performance liquid chromatography fingerprint analysis indicated the presence of rutin, narirutin, and ρ-coumaric acid in PLW (6.30, 119.76, and 47.25 ppm, respectively). Treating cells with these compounds at non-toxic concentrations had no effect on NO production. Taken together, these results suggest that PLW may have potential as an immunity-enhancing supplement.

• Journal of Technologic Dentistry
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• 제42권4호
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• pp.355-361
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• 2020

Purpose: In this study, we added two kinds of photoinitiators (CQ and TPO) to prepare two kinds of denture base resins (Bis-GMA series and UDMA series) for three-dimensional (3D) printing to compare and analyze their mechanical and biological properties and to find the optimal composition. Methods: Control specimens were made using the mold made of polyvinyl siloxane of the same size. Light curing was performed twice for 20 seconds on both the upper and lower surfaces with LED (light emitting diode) light-curing unit (n=10). Experimental 3D printing dental resins were prepared, to which two photoinitiators were added. Digital light processing type 3D printer (EMBER, Autodesk, CA, USA) was used for 3D printing. The specimen size was 64 mm×10 mm×3.3 mm according to ISO 20795-1. The final specimens were tested for flexural strength and flexural modulus, and MTT test was performed. Furthermore, one-way analysis of variance was performed, and the post-test was analyzed by Duncan's test at α=0.05. Results: The flexural strength of both Bis-GMA+CQ (97.12±6.47 MPa) and UDMA+TPO (97.40±3.75 MPa) was significantly higher (p<0.05) in the experimental group. The flexural modulus in the experimental group of UDMA+TPO (2.56±0.06 GPa) was the highest (p<0.05). MTT test revealed that all the experimental groups showed more than 70% cell activity. Conclusion: The composition of UDMA+TPO showed excellent results in flexural strength, flexural modulus, and biocompatibility.

• Journal of Korean Neurosurgical Society
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• 제64권1호
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• pp.30-38
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• 2021

Objective : The Solitaire Platinum 4×40 mm stent retriever contains radiopaque markers with a long length. We evaluated the effect of Solitaire Platinum 4×40 mm stent retriever in Solumbra technique thrombectomy, and compared it with shorter Solitaire stent retrievers. Methods : A total of 70 patients who underwent Solumbra technique thrombectomy with equal diameter (4 mm) and different length (40 vs. 20 mm) Solitaire stent retrievers were divided into two groups : the Solitaire Platinum 4×40 mm stent (4×40) group and the Solitaire FR 4×20 mm stent or Solitaire Platinum 4×20 mm stent (4×20) group. The clinical outcomes, Thrombolysis in Cerebral Infarction score, the first pass reperfusion status, and complications were evaluated and compared between the two groups. Multivariate analysis was performed to evaluate the predictive factors for reperfusion and complete reperfusion from the first pass. Results : Higher first-pass reperfusion and complete reperfusion were achieved in the 4×40 group (68.0% and 48.0%) than in the 4×20 group (46.7% and 33.3%; p=0.004 and 0.007, respectively). In multivariate analysis, radiopaque device and longer stent retriever were correlated with first-pass reperfusion (p=0.014 and 0.008, respectively) and first-pass complete reperfusion (p=0.022 and 0.012, respectively). Conclusion : Our study demonstrated the usefulness of the Solitaire Platinum 4×40 mm stent retriever, which led to higher first-pass reperfusion and complete reperfusion rates than the Solitaire FR 4×20 mm stent or the Solitaire Platinum 4×20 mm stent, especially in Solumbra technique thrombectomy.