• Microbiology and Biotechnology Letters
• /
• v.17 no.2
• /
• pp.115-120
• /
• 1989

For the purpose of obtaining microorganisms which produced an extracellular pepsin inhibitor, screening test was carried out. One strain of Actinomycetes (GF 155-2) isolated from soil samples showed a high inhibitory activity against porcine pepsin. The morphological, physiological and cultural characteristics of the strain GE 155-2 on various culture media were studied according to ISP methods and Bergey's manual of determinative bacteriology (8th ed.). This Actinomycetes GE 155-2 was found to be similar to the genus Microtetraspora.

• Journal of Electrochemical Science and Technology
• /
• v.7 no.2
• /
• pp.153-160
• /
• 2016

The inhibition ability of N,N-bis(2,4-dihydroxyhydroxybenzaldehyde)-1,3-Propandiimine (DHBP) as a schiff base against the corrosion of API-5L-X65 steel in 1 M HCl solution was evaluated by electrochemical impedance spectroscopy, potentiodynamic polarization and scanning electron microscopy. Electrochemical impedance studies indicated that DHBP inhibited corrosion by blocking the active corrosion sites. The inhibition efficiency increased with increasing inhibitor concentrations. EIS data was analysed to equivalent circuit model and showed that the charge transfer resistance of steel increased with increasing inhibitor concentration whilst the double layer capacitance decreased. The adsorption of this compound obeyed the Langmuir adsorption isotherm. Gibbs free energy of adsorption was calculated and indicated that adsorption occurred through physical and spontaneous process. The corrosion inhibition mechanism was studied by potential of zero charge. Polarization studies indicated that DHBP retards both the cathodic and anodic reactions through adsorption on steel surface. Scanning electron microscopy was used to study the steel surface with and without inhibitor.

• Korean Journal of Bronchoesophagology
• /
• v.16 no.2
• /
• pp.97-104
• /
• 2010

Gastroesophageal reflux disease (GERD) is a common disorder caused by the reflux of gastric contents into the esophagus. According to the recent classification, GERD can elicit esophageal and extraesophageal syndromes. Laryngopharyngeal reflux (LPR) is defined as laryngeal symptoms with laryngeal inflammation caused by the acid reflux. The prevalence of GERD and LPR is increasing during the past decades in Korea and management of GERD and LPR is a challenging issue in clinical practice. Proton pump inhibitor is the most effective drug in the treatment of GERD. Most patients with LPR are given a 2-month trial of a proton pump inhibitor (PPI), however, there is still little evidence on the diagnosis or the treatment of LPR. During the last years concern have been raised regarding the risk of averse events related to long-term use of PPI. We review the recent update on medical treatment of GERD/LPR.

• Journal of Microbiology and Biotechnology
• /
• v.6 no.6
• /
• pp.445-450
• /
• 1996

Gelatinase A is a member of the matrix metalloproteinases that play an important role in cancer invasion and metastasis. In the course of screening gelatinase A inhibitors from microbial sources, a fungal strain PT-262 showed a strong inhibitory activity. The strain was identified as Chaunopycnis alba on the basis of its morphological characteristics. The inhibitor was isolated from acetone extract of mycelial cake by sequential chromatographies on MCI-gel, Sephadex LH-20, and a reverse-phase HPLC column. The purified inhibitor was identified as pyridoxatin by its physico-chemical properties and spectroscopic analysis. Pyridoxatin is not a peptide analog and has cyclic hydroxamic acid moiety. It inhibited activated gelatinase A with an $IC_{50}$ value of 15.2 ${\mu}M$ using fluorescent synthetic peptide. It also had a strong cytotoxicity against human cancer cell lines in vitro. Furthermore, this compound inhibited DNA synthesis with an $IC_{50}$ value of 2.92 ${\mu}M$ in PC-3 prostate cancer cells by [$^3H$]thymidine incorporation assay.

• Applied Chemistry for Engineering
• /
• v.20 no.2
• /
• pp.172-176
• /
• 2009

In this research, we defined the basic structure of soft etching material as $H_2SO_4/H_2O_2$, and used additives as inhibitor, surfactant, and stabilizer. By analyzing influence to surface roughness and change of etching rate related to type and density of additives, we research to develop soft etching material having the same adhesiveness as existing etching material. As a result of research, it is estimated that after densities of $H_2O_2$ and $H_2SO_4$ are 3%, 4% respectively, 500 ppm of amine type 5-Azol, as inhibitor, and 600 ppm of PEI, as surfactant, and 10 ppm of phosphoric acid, as stabilizer, are added, is the most reasonable surface roughness and etching rate. As result of solder test, it is estimated that solder resist ink did not peel away or curl up and have reliable adhesiveness.

• Korean Journal of Microbiology
• /
• v.50 no.4
• /
• pp.381-383
• /
• 2014

In the course of screening for ${\alpha}$-glucosidase inhibitor produced by microorganism, the active compound was isolated from the culture filtrate of Bacillus sp. SKU31-1 using a series of chromatography procedures. The structure of the active compound was elucidated as 5-amino-1-hydroxymethyl-1, 2, 3, 4-cyclohexanetetrol on the basis of spectroscopic evidence obtained and comparison with data from the literature. The active compound showed potent inhibitory activity against ${\alpha}$-glucosidase with an $IC_{50}$ value of $1.9{\mu}M$ for maltose and 4.9 mM for sucrose. A Lineweaver-Burk plot indicated that its inhibition of ${\alpha}$-glucosidase was competitive, with a $K_i$ value of 0.15 mM.

• Journal of Korean Neurosurgical Society
• /
• v.50 no.1
• /
• pp.1-5
• /
• 2011

Objective : There is no proven regimen to reduce the severity of stroke in patients with acute cerebral infarction presenting beyond the thrombolytic time window. Ozagrel sodium, a selective thromboxane A2 synthetase inhibitor, has been known to suppress the development of infarction. The antiplatelet effect is improved when aspirin is used together with a thromboxane synthetase inhibitor. Methods : Patients with non-cardiogenic acute ischemic stroke who were not eligible for thrombolysis were randomly assigned to two groups; one group received ozagrel sodium plus 100 mg of aspirin (group 1, n=43) and the other 100 mg of aspirin alone (group 2, n=43). Demographic data, cardiovascular risk factors, initial stroke severity [National Institute of Health Stroke Scale (NIHSS) and motor strength scale] and stroke subtypes were analyzed in each group. Clinical outcomes were analyzed by NIHSS and motor strength scale at 14 days after the onset of stroke. Results : There were no significant differences in the mean age, gender proportion, the prevalence of cardiovascular risk factors, stroke subtypes, and baseline neurological severity between the two groups. However, the clinical outcome for group 1 was much better at 14 days after the onset of stroke compared to group 2 (NIHSS score, p=0.007, Motor strength scale score, p<0.001). There was one case of hemorrhagic transformation in group 1, but there was no statistically significant difference in bleeding tendency between two groups. Conclusion : In this preliminary study, thromboxane A2 synthetase inhibitor plus a low dose of aspirin seems to be safe and has a favorable outcome compared to aspirin alone in patients with acute ischemic stroke who presented beyond the thrombolytic time window.

• Biomolecules & Therapeutics
• /
• v.28 no.1
• /
• pp.98-103
• /
• 2020

Marfan syndrome (MFS), a connective tissue disorder caused by mutations in the fibrillin-1 (Fbn1) gene, has vascular manifestations including aortic aneurysm, dissection, and rupture. Its vascular pathogenesis is assumed to be attributed to increased transforming growth factor β (TGFβ) signaling and blockade of excessive TGFβ signaling has been thought to prevent dissection and aneurysm formation. Here, we investigated whether galunisertib, a potent small-molecule inhibitor of TGFβ receptor I (TβRI), attenuates aneurysmal disease in a murine model of MFS (Fbn1^C1039G/+) and compared the impact of galuninsertib on the MFS-related vascular pathogenesis with that of losartan, a prophylactic agent routinely used for patients with MFS. Fbn1^C1039G/+ mice were administered galunisertib or losartan for 8 weeks, and their ascending aortas were assessed for histopathological changes and phosphorylation of Smad2 and extracellular signal-regulated kinase 1/2 (Erk1/2). Mice treated with galunisertib or losartan barely exhibited phosphorylated Smad2, suggesting that both drugs effectively blocked overactivated canonical TGFβ signaling in Fbn1^C1039G/+ mice. However, galunisertib treatment did not attenuate disrupted medial wall architecture and only partially decreased Erk1/2 phosphorylation, whereas losartan significantly inhibited MFS-associated aortopathy and markedly decreased Erk1/2 phosphorylation in Fbn1^C1039G/+ mice. These data unexpectedly revealed that galunisertib, a TβRI inhibitor, showed no benefits in aneurysmal disease in MFS mice although it completely blocked Smad2 phosphorylation. The significant losartan-induced inhibition of both aortic vascular pathogenesis and Smad2 phosphorylation implied that canonical TGFβ signaling might not prominently drive aneurysmal diseases in MFS mice.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.04a
• /
• pp.253-257
• /
• 2011

Vortex generation mechanism by inhibitor in a solid rocket motor have been investigated by 3D Large Eddy Simulation turbulent model. Most of the result of the present study are in good agreement with experimental data and previous numerical calculation. Vortex generation and breakdown behind inhibitor are periodically observed between inhibitor and nozzle head by flow-acoustic coupling mechanism. Vortex generation frequency is the same as the second-mode frequency in the motor. The roll shape vortex generation behind inhibitor induces non-uniform flow field at the nozzle entrance and its throat.

• Genomics & Informatics
• /
• v.18 no.4
• /
• pp.37.1-37.11
• /
• 2020

BET inhibitor, as an epigenetic regulator inhibitor, reduces the expression of oncogenes such as Myc and Bcl-2, which affects cancer growth and development. However, it has modest activity because of the narrow therapeutic index. Therefore, combination therapy is necessary to increase the anti-tumor effect. Paclitaxel, an anti-mitotic inhibitor, is used as second-line therapy for gastric cancer (GC) as a monotherapy or combination. In this study, we performed RNA sequencing of GC cells treated with iBET-151 and/or paclitaxel to identify the differentially expressed genes associated with possible mechanisms of synergistic effect. We also performed Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses to determine the most enriched terms and pathways of upregulated and downregulated genes. We found 460 genes in which iBET-151 and paclitaxel combination treatment changed more than single-treatment or no-treatment. Thus, additional functional studies are needed, but our results provide the first evidence of the synergistic effect between iBET-151 and paclitaxel in regulating the transcriptome of GC cells.