• Journal of Life Science
• /
• v.25 no.1
• /
• pp.101-112
• /
• 2015

A type of cell junction that is formed between different parts within the same cell is called autotypic cell junction. Autotypic junction proteins form tight junctions found between membrane lamellae of a cell, especially in myelinating glial cells. Some of them have postsynaptic density-95/disks large/zonula occludens-1 (PDZ) domains, which interact with the carboxyl (C)-terminal PDZ-binding motif of other proteins. PDZ domains are protein-protein interaction modules that play a role in protein complex assembly. The PDZ domain, which is widespread in bacteria, plants, yeast, metazoans, and Drosophila, allows the assembly of large multi-protein complexes. The multi-protein complexes act in intracellular signal transduction, protein targeting, and membrane polarization. The identified PDZ domain-containing proteins located at autotypic junctions include zonula occludens-1 (ZO-1), ZO-2, pals-1-associated tight junction protein (PATJ), multi-PDZ domain proteins (MUPPs), membrane-associated guanylate kinase inverted 2 (MAGI2), and protease-activated receptor (PAR)-3. PAR-3 interacts with atypical protein kinase C and PAR-6, forming a ternary complex, which plays an important role in the regulation of cell polarity. MAGI2 interacts with ${\alpha}$-amino-3-hydroxyl-5-methyl-4-isoxazole propionate (AMPA) receptor at excitatory synapses. PATJ is detected in paranodal loops associated with claudin-1. On the other hand, MUPP1 is found in mesaxons and Schmidt-Lanterman incisures with claudin-5. ZO-1, ZO-2, and PAR-3 are found at all three sites. Different distributions of PDZ domain-containing proteins affect the development of autotypic junctions. In this review, we will describe PDZ domain-containing proteins at autotypic tight junctions in myelinating Schwann cells and their roles.

• Journal of Life Science
• /
• v.30 no.4
• /
• pp.343-351
• /
• 2020

Sorbus commixta Hedl. has traditionally been used as a remedy for cough, asthma, and other bronchial disorders. In this study, three major triterpenoids-lupeol, β-sitosterol, and ursolic acid and a coumarin, scopoletin, were isolated from a CHCl₃-soluble fragment of the bark of S. commixta. Their structures were identified by spectroscopic analyses, including mass spectrometry (MS), 1D-, and 2D- nuclear magnetic resonance spectroscopy (NMR), as well as by comparing the data with data reported in the literature. Scopoletin was isolated from this plant for the first time. It is a nutraceutical compound contained in many plants that has been reported to exert diverse biological activities, including anti-inflammatory effects. This study examined the inhibitory effect of scopoletin on TNF-α-induced vascular endothelial inflammation. Unlike the marginal impact of other compounds against low-density lipoprotein (LDL) oxidation and vascular endothelial inflammation, scopoletin showed remarkable activity on LDL oxidation (IC₅₀ = 10.2 μM) and exerted vascular anti-inflammatory effects in EA.hy926 human endothelial cells activated by TNF-α. It suppressed the expression of adhesion molecules, such as ICAM-1, VCAM-1, and E-selectin, and blocked the adhesion between THP-1 monocytes and EA. hy926 endothelial cells. It also inhibited TNF-α-induced NF-κB translocation from the cytosol to the nucleus. Moreover, IκBα phosphorylation, which was increased by TNF-α treatment, was reduced after treatment with scopoletin. Thus, scopoletin inhibited TNF-α-induced vascular inflammation in endothelial cells by suppressing the NF-κB signaling pathway. These results demonstrate that owing to its anti-inflammatory activity in the vascular endothelium, scopoletin has the potential to inhibit atherosclerosis development.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.9 no.4
• /
• pp.207-217
• /
• 2011

In this study the complex formation reactions between uranium(VI) and 2,6-dihydroxybenzoate (DHB) as a model ligand of humic acid were investigated by using UV-Vis spectrophotometry and time-resolved laser-induced fluorescence spectroscopy (TRLFS). The analysis of the spectrophotometric data, i.e., absorbance changes at the characteristic charge-transfer bands of the U(VI)-DHB complex, indicates that both 1:1 and 1:2 (U(VI):DHB) complexes occur as a result of dual equilibria and their distribution varies in a pH-dependent manner. The stepwise stability constants determined (log $K_1$ and log $K_2$) are $12.4{\pm}0.1$ and $11.4{\pm}0.1$. Further, the TRLFS study shows that DHB plays a role as a fluorescence quencher of U(VI) species. The presence of both a dynamic and static quenching process was identified for all U(VI) species examined, i.e., ${UO_2}^{2+}$, $(UO_2)_2{(OH)_2}^{2+}$, and $(UO_2)_3{(OH)_5}^+$. The fluorescence intensity and lifetimes of each species were measured from the time-resolved spectra at various ligand concentrations, and then analyzed based on Stern-Volmer equations. The static quenching constants (log $K_s$) obtained are $4.2{\pm}0.1$, $4.3{\pm}0.1$, and $4.34{\pm}0.08$ for ${UO_2}^{2+}$, $(UO_2)_2{(OH)_2}^{2+}$, and $(UO_2)_3{(OH)_5}^+$, respectively. The results of Stern-Volmer analysis suggest that both mono- and bi-dentate U(VI)-DHB complexes serve as groundstate complexes inducing static quenching.

• Pediatric Infection and Vaccine
• /
• v.11 no.2
• /
• pp.183-191
• /
• 2004

Purpose : The purpose of this study was to compare the clinical features of staphylococcal scalded skin syndrome(SSSS) isolated methicillin-resistant Staphylococcal aureus(MRSA) with those of SSSS isolated methicillin-sensitive Staphylococcal aureus(MSSA) in children. Methods : We retrospectively reviewed the medical records and microbiological results of 36 cases of SSSS who were admitted to the Pediatric Department of Ulsan Dong-Kang General Hospital from Jan. 1999 to Dec. 2003. Results : Among 36 cases, there were 7 generalized types, 1 abortive type in MRSA group and 5 generalized types, 6 abortive types in MSSA group. The peak incidence of age was between 2 and 5 years in both groups. SSSS were diagnosed with increasing frequency. Most of MRSA group were diagnosed in 2003(6/8). The peak seasonal incidence was fall and winter in both groups. Facial lesion was observed in all cases followed by flexural lesion in both groups. Staphylococci were isolated from the skin and throat most frequently in both groups. Upper respiratory illness and conjunctivitis were most common preceding infections in both groups. Among 8 cases of MRSA group, 4 cases were treated completely with ampicillin-sulbactam. There was no significant difference of mean duration of admission between MRSA group and MSSA group. Conclusion : There was no significant difference of clinical features between MRSA group and MSSA group although generalized types of SSSS were more common in MRSA group than in MSSA group.

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.3
• /
• pp.312-317
• /
• 1985

Growth response and nutrients uptake of tobacco grown on mulched and non mulched plots were investigated during the growing period. 1. The whole growing time was about 25 days shorter and relative growth rate was faster in the mulched plot than in the non mulched plot. 2. Nitrate content of leaf in the latter stage of tobacco grown on the non mulched plot was more continuously increased compared with mulched plot. As a result in the latter stage of tobacco leaf nitrate form of nitrogen level was much higher on non mulched plot than on mulched plot. 3. Reducing sugar content in cured leaves of tobacco grown on the non mulched plot was lower that of the mulched plot. This difference in reducing sugar content was remarkable in the bottom leaves that nitrate content was highest. 4. Tobacco growing on nonmulched soil may cause to be low quality owing to increasing of nitrogen compound and decreasing of reducing sugar content in cured leaves. 5. As distributions of nitrate and potassium content in leaves at different stalk position was similar each other, nitrate and potassium ion considered to be counter ion in absorption and translocation through the tobacco plant.

• The Korean Journal of Nuclear Medicine
• /
• v.29 no.1
• /
• pp.41-47
• /
• 1995

Tc-99m-MIBI(Sestamibi) myocardial SPECT along with T1-201 tomographic imaging has demonstrated wide application and high image qualify sufficient for the diagnosis of myocardial perfusion defect, which consequently reflects regional myocardial blood flow, The qualitative values of myocardial SPECT with Tc-99m-MIBI as well as the quantitative cases depend in some degree on the reconstruction techniques of multiple projections. Filtered backprojection(FBP) is the common standard for reconstruction rather than the complicated and time-consuming arithmetic methods. In FBP it Is known that the distribution of radioactivity in reconstructed transverse slices varies with the selected filter parameters such as cutoff frequencies and order(Butterworth case). The cutoff frequencies basically remove and decrease the true radioactive distribution and alter the pixel counts, which lead to underestimation of true counts in specific myocardial regions. In this study, we have investigated the effect of cutoff frequencies of reconstruction filter on the artifactually induced perfusion defects, which are often demonstrated near inferior and/or inferoseptal cardiac walls due to the intense hepatic uptake of Tc-99m-MIBI. A computerized method for identifying the relative degree of artifactual perfusion defect and for comparing those degrees along with the relative amount of hepatic uptake to myocardium was developed and patient images were studied to observe the quantitative degree of underestimation of myocardial perfusion, and to propose some reasonable thresh-old of cutoff frequency in the diagnosis of perfusion defect quantitatively. We concluded that from the quantitative viewpoint cutoff frequencies may be used as high as possible with the sacrifice of homogeneity of image quality, and those frequencies lower than the common 0.3 Nyquist frequency would reveal severe degradation of radio-active distribution near inferior and/or Inferoseptal myocardium when applying Butterworth or low pass filter.

• The Korean Journal of Nuclear Medicine
• /
• v.29 no.1
• /
• pp.73-78
• /
• 1995

[ $^{99m}Tc$ ]-MDP bone scan was performed in 31 patients with primary malignant bone tumors, 22 patients with osteogenic sarcoma, 5 patients with chondrosarcoma and 4 patients with Ewing's sarcoma. The findings were classified by isotope intensity of accumulation in tumor as grade 1 to 3, overall pattern of isotope distribution in tumor as grade 1 to 3, and distortion of bony outline as grade 1 to 3. Histologic classifications were cor related with scan findings in 22 patients with osteogenic sarcoma. The results were as follows 1) In 22 patients with osteogenic sarcoma, markedly increased isotope intensity higher than sacroiliac joint with patchy areas of decreased intensity and severe bony distortion were found in 16 patients. The correlations between histologic classification and scan findings were not discovered. 2) In 5 patients with chondrosarcoma, mildly increased isotope Intensity with patchy areas of increased intensity and mild bony distortion were found in 4 patients.. 3) In 4 patients with Ewing's sarcoma, markedly increased homogenous intensity with moderate bony distortion were found in 3 patients. Conclusively there were common findings in each 3 primary malignant bone tumors and $^{99m}Tc$-MDP bone scan was complemented with radiologic studies in differentiating primary malignant bone tumors.

• The Korean Journal of Nuclear Medicine
• /
• v.30 no.1
• /
• pp.112-117
• /
• 1996

Objective: Standard stress/rest Tc-99m MIBI and T1-201 myocardial perfusion study have some limitations such as stress/rest image overlap for Tc-99m-MIBI, low energy for T1-201 and long period of study time for two separate studies. Separate acquisition rest T1-201/stress Tc-99m MIBI dual isotope study is a potentially efficient myocardial perfusion imaging protocol that combines the high resolution of Tc-99m for stress perfusion assessment and T1-201 for viability assessment. This study assessed the usefulness and diagnostic accuracy for this new approach. Methods: We tried to evaluate sensitivity and specificity of dual isotope separate acquisition protocol in 67 patients. Immediately after resting T1-201 SPECT data was acquired, dipyridamole stress Tc-99m MIBI myocardial perfusion study was performed. Visual analysis was carried out qualitatively with 0 to 3 scoring system for 17 segments of left ventricle in the reconstructed horizontal long axis and short axis slices. Results: Total study was completed within 3 hours. In angiographic correlation, dual isotope SPECT demonstrated high sensitivity(85%) and in a small group of patients, high specificity was also observed (100%). Conclusion: Combined thallium-201/stress Tc-99m MIBI SPECT displayed similiar diagnostic accuracy to protocol using stress/rest Tc-99m MIBI SPECT. This protocol was completed in shorter period than the previous protocols and therefore enhance laboratory throughput and patients convenience.

• The Korean Journal of Nuclear Medicine
• /
• v.30 no.4
• /
• pp.484-492
• /
• 1996

To detect ischemic tissue in experimental model of cerebral ischemia made by middle cerebral artery(MCA)-occlusion, we acquired triple image of $^{99m}Tc$-glucarate, [$^{18}F$]fluoro-deoxyglucose (FDG), and 2,3,5- triphenyltetrazolium (TTC) staining. We made cerebral infarction either with reperfusion (after occlusion of 2 hours) or without reperfusion in 10 Sprague-Dawley rats by inserting thread to MCA through internal carotid artery. After 22 hours, we injected 740 MBq of $^{99m}Tc$-glucarate and 55.5 MBq of [$^{18}F$]FDG through tail vein. Each 1 mm slice of rat brains was frozen and exposed to imaging plate for 20 minutes in freezer to get an [$^{18}F$]FDG image. After 20 hours enough to fade radioactivity of [$^{18}F$]FDG, the slices were again imaged by BAS1500 for $^{99m}Tc$-glucarate uptake. Finally, these brain tissues were stained with TTC. Semi-quantitative visual analysis was done by grading 0 to 3 points according to the degree of uptakes($^{99m}Tc$-glucarate) and decreased uptakes([$^{18}F$]FDG and TTC). Ten rats survived with neurologic symptoms. TTC staining confirmed the development of infarction. The size of the infarction was relatively larger in the group without reperfusion. [$^{18}F$]FDG images were similar to TTC-stained images. However, we found regions with intermediate uptake which were not stained with TTC. We found regions with intermediate [$^{18}F$]FDG uptake where TTC staining was normal. $^{99m}Tc$-glucarate uptake was round only in TTC non-stained region. In the TTC stained regions, there were no uptake of $^{99m}Tc$-glucarate. We could not find clear relation between $^{99m}Tc$-glucarate uptake with [$^{18}F$]FDG uptake. This was partly because percent uptake of $^{99m}Tc$-glucarate was so small (less than 1 percent of injected dose) and because there were quite heterogeneity of patterns of [$^{18}F$]FDG uptake and TTC. With these findings, we could conclude that $^{99m}Tc$-glucarate were taken up only in part of ischemic tissues which were proven to be nonviable. The establishment of MCA-occluded rat model with or without reperfusion and triple imaging for $^{99m}Tc,\;^{18}F$ and TTC helped the characterization of $^{99m}Tc$-glucarate uptakes. Further work is needed to clarify the meaning or diversities or [$^{18}F$]FDG and TTC and their relation with $^{99m}Tc$-glucarate.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.14 no.2
• /
• pp.142-149
• /
• 2014

Purpose: There are 15 types of Glycogen storage disease (GSD) that have been identified, and GSD type Ia is the most common type. There are several studies of Korean GSD type Ia patients' long-term complications. The aim of this study to find out clinical symptoms and prognosis of GSD type Ia patients. Methods: We performed clinical, biochemical and genetic analysis retrospectively on five patients diagnosed with GSD type Ia in a Soonchunhyang University Hospital from July 2002 to July 2014. Results: All patients had hepatomegaly at diagnosis, and they were all confirmed to have fatty liver at abdomen USG. They had no developmental delay, but two of them had growth retardation. Elevated blood lactate, triglyceride, and uric acid levels can find out all patients, but only one patient had hypoglycemia. They are diagnosed with GSD through gene analysis, and by gene analysis, they have c.648G>T (homozygote, splicing mutation), c.122G>A/c.648G>T, c.248G>A/c.648G>T mutations. Treatment with three times meals, three times snacks and four to six times use of uncooked constarch for all patients. Following the progress, one of them resulted in hypothyroidism, other one had renal stones. A patient diagnosed at 16 years old had liver cirrhosis and started having hemodialysis for ESRD. Conclusion: GSD type Ia patients had hepatomegaly, hyperlipidemia, hyperuricemia, and lactacidemia. Therefore patients who have such these symptoms are recommended gene analysis. A patient diagnosed at 16-years-old had liver cirrhosis and ESRD in progress, early diagnosis and treatment are important for GSD type Ia patients.