Publications by authors named "Jeong Woo Son"

9 Publications

  • Page 1 of 1

Feasibility of dosimetric measurements using Al2O3:C OSL dosimeter during fluoroscopy-guided procedures.

J Radiol Prot 2020 Oct 7. Epub 2020 Oct 7.

radiation oncology, Seoul National University Hospital, Seoul, Korea (the Republic of).

This study investigated the feasibility of dosimetric measurements using Al2O3:C optically stimulated luminescence (OSL) dosimeters during fluoroscopy-guided procedures. The linearity and energy dependence of Al2O3:C OSL dosimeters were evaluated, and the air kerma rate at the operator's position was measured. The response of Al2O3:C OSL dosimeters to short, repetitive irradiations was compared to that of long uninterrupted irradiation. The change in response of the Al2O3:C OSL dosimeter under automatic exposure rate control (AERC) was evaluated with the use of various thicknesses of polymethyl-methacrylate (PMMA) plates (15-30 cm). The Al2O3:C OSL dosimeters could detect 5 µGy and showed good linearity in doses of ≥ 10 µGy (R²: 0.997-0.999, p < 0.001). The relative response of the Al2O3:C OSL dosimeter normalized to that of 36.8 keV was 0.828-1.101 at the energies investigated (30.6-46.0 keV). The air kerma rate at the operator's position was estimated to be 2.61-7.17 µGy/min depending on the heights representing different body parts. Repetitive short irradiations had no significant impact on the relative response of the Al2O3:C OSL dosimeters (p > 0.05). Despite a high energy dependence on the low energy beam used in fluoroscopy, the change in relative response of the Al2O3:C OSL dosimeter under AERC was within 5.7% depending on the thickness of the PMMA plates. Dosimetric measurement using Al2O3:C OSL dosimeters for patients and operators is feasible. However, one should be cautious about high standard deviations when measuring small doses of ≤ 20 µGy using Al2O3:C OSL dosimeters. It is essential to perform intensive bleaching before measuring very small doses to minimize pre-irradiation counts.
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http://dx.doi.org/10.1088/1361-6498/abbf3aDOI Listing
October 2020

Development of peptide aptamers as alternatives for antibody in the detection of amyloid-beta 42 aggregates.

Anal Biochem 2020 11 20;609:113921. Epub 2020 Aug 20.

Department of Chemistry and Research Institute of Natural Sciences, Hanyang University, Seoul, 04763, Republic of Korea. Electronic address:

Alzheimer's disease (AD) causes cognitive impairment and serious social isolation. However, there are no effective treatments and even no established confirmatory diagnostic tools for the disease. Amyloid beta (Aβ) aggregation in the brain is the best-known pathognomonic mechanism of AD, so various methods for Aβ detection have been developed for the diagnosis of this disease. We synthesized two novel, ultra-sensitive peptide probes specialized in detecting Aβ aggregates, and examined their potential for future diagnostic application. The peptides are produced through phage high-throughput screening (HTS) and amplified through a serial process called biopanning, which is a repeating method of elution and amplification of probes. We picked phages specific for amyloid from two kinds of phage display. The synthesized peptides were confirmed to have excellent binding affinity to Aβ aggregates, by immunohistochemical staining and western blotting using the brains of 3X transgenic (Tg) AD mice at different stages (5-7, 12-17 months old) of AD severity. In the present study, it was confirmed that newly developed amyloid-binding peptides could be used as novel probes for the detection of Aβ aggregates, which can be used for clinical diagnosis of AD in the future.
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http://dx.doi.org/10.1016/j.ab.2020.113921DOI Listing
November 2020

Glia-Like Cells from Late-Passage Human MSCs Protect Against Ischemic Stroke Through IGFBP-4.

Mol Neurobiol 2019 Nov 12;56(11):7617-7630. Epub 2019 May 12.

Department of Neurology, Hanyang University College of Medicine, Gyeongchun-ro, Guri-Si, 11923, Gyeonggi-do, Republic of Korea.

Stem cell therapy is considered to be a promising future treatment for intractable neurological diseases, although all the clinical trials using stem cells have not yet shown any good results. Early passage mesenchymal stem cells (MSCs) have been used in most clinical trials because of the issues on safety and efficacy. However, it is not easy to get plenty of cells enough for the treatment and it costs too much. Lots of late passage MSCs can be obtained at lower cost but their efficacy would be a big hurdle for clinical trials. If late passage MSCs with better efficacy could be used in clinical trials, it could be a new and revolutionary solution to reduce cost and enhance easier clinical trials. In the present study, it was investigated whether late passage MSCs could be induced into glia-like cells (ghMSCs); ghMSCs had better efficacy and they protected neurons and the brain from ischemia, and insulin-like growth factor binding protein-4 (IGFBP-4) played a critical role in beneficial effect of ghMSCs. ghMSCs were induced from MSCs and treated in in vitro and in vivo models of ischemia. They effectively protected neurons from ischemia and restored the brain damaged by cerebral infarction. These beneficial effects were significantly blocked by IGFBP-4 antibody. The current study demontsrated that late passage hMSCs can be efficiently induced into ghMSCs with better neuroprotective effect on ischemic stroke. Moreover, the results indicate that IGFBP-4 released from ghMSCs may serve as one of the key neuronal survival factors secreted from ghMSCs.
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http://dx.doi.org/10.1007/s12035-019-1629-8DOI Listing
November 2019

Tracking and protection of transplanted stem cells using a ferrocenecarboxylic acid-conjugated peptide that mimics hTERT.

Biomaterials 2018 Feb 14;155:80-91. Epub 2017 Nov 14.

Department of Neurology, Hanyang University Guri Hospital, 153, Gyeongchun-ro, Guri-si, Gyeonggi-do 11923, South Korea; Department of Translational Medicine, Hanyang University Graduate School of Biomedical Science & Engineering, Seoul, 04763, South Korea. Electronic address:

In vivo tracking of transplanted stem cells has been a central aim of stem cell therapy. Although many tracking systems have been introduced, no method has yet been validated for clinical applications. We developed a novel sophisticated peptide (GV1001) that mimics hTERT (human telomerase reverse transcriptase) and analysed its ability to track and protect stem cells after transplantation. Ferrocenecarboxylic acid-conjugated GV1001 (Fe-GV1001) efficiently penetrated stem cells with no adverse effects. Moreover, Fe-GV1001 improved the viability, proliferation, and migration of stem cells under hypoxia. After Fe-GV1001-labelled stem cells were transplanted into the brains of rats after stroke, the labelled cells were easily tracked by MRI. Our findings indicate that Fe-GV1001 can be used for the in vivo tracking of stem cells after transplantation into the brain and can improve the efficacy of stem cell therapy by sustaining and enhancing stem cell characteristics under disease conditions.
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http://dx.doi.org/10.1016/j.biomaterials.2017.11.009DOI Listing
February 2018

Association between public cardiopulmonary resuscitation education and the willingness to perform bystander cardiopulmonary resuscitation: a metropolitan citywide survey.

Clin Exp Emerg Med 2017 Jun 30;4(2):80-87. Epub 2017 Jun 30.

Department of Emergency Medicine, Daegu Fatima Hospital, Daegu, Korea.

Objective: Bystander cardiopulmonary resuscitation (CPR) is an important factor associated with improved survival rates and neurologic prognoses in cases of out-of-hospital cardiac arrest. We assessed how factors related to CPR education including timing of education, period from the most recent education session, and content, affected CPR willingness.

Methods: In February 2012, trained interviewers conducted an interview survey of 1,000 Daegu citizens through an organized questionnaire. The subjects were aged ≥19 years and were selected by quota sampling. Their social and demographic characteristics, as well as CPR and factors related to CPR education, were investigated. Chi-square tests and multivariate logistic regression analyses were used to evaluate how education-related factors affected the willingness to perform CPR.

Results: Of total 1,000 cases, 48.0% were male. The multivariate analyses revealed several factors significantly associated with CPR willingness: didactic plus practice group (adjusted odds ratio [AOR], 3.38; 95% confidence interval [CI], 2.3 to 5.0), group with more than four CPR education session (AOR, 7.68; 95% CI, 3.21 to 18.35), interval of less than 6 months from the last CPR education (AOR, 4.47; 95% CI 1.29 to 15.52), and education with automated external defibrillator (AOR, 5.98; 95% CI 2.30 to 15.53).

Conclusion: The following were associated with increased willingness to perform CPR: practice sessions and automated electrical defibrillator training in public CPR education, more frequent CPR training, and shorter time period from the most recent CPR education sessions.
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http://dx.doi.org/10.15441/ceem.16.160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5511954PMC
June 2017

Surface-Based Parameters of Brain Imaging in Male Patients with Alcohol Use Disorder.

Psychiatry Investig 2016 Sep 30;13(5):511-517. Epub 2016 Sep 30.

Department of Psychiatry, Chungbuk National University College of Medicine, Cheongju, Republic of Korea.

Objective: The structural alteration of brain shown in patients with alcohol use disorder (AUD) can originate from both alcohol effects and genetic or developmental processes. We compared surface-based parameters of patients with AUD with healthy controls to prove the applicability of surface-based morphometry with head size correction and to determine the areas that were sensitive to brain alteration related to AUD.

Methods: Twenty-six abstinent male patients with AUD (alcohol group, mean abstinence=13.2 months) and twenty-eight age-matched healthy participants (control group) were recruited from an inpatient mental hospital and community. All participants underwent a 3T MRI scan. Surface-based parameters were determined by using FreeSurfer.

Results: Every surface-based parameter of the alcohol group was lower than the corresponding control group parameter. There were large group differences in the whole brain, grey and white matter volume, and the differences were more prominent after head size correction. Significant group differences were shown in cortical thicknesses in entire brain regions, especially in parietal, temporal and frontal areas. There were no significant group differences in surface areas, but group difference trends in surface areas of the frontal and parietal cortices were shown after head size correction.

Conclusion: Most of the surface-based parameters in alcohol group were altered because of incomplete recovery from chronic alcohol exposure and possibly genetic or developmental factors underlying the risk of AUD. Surface-based morphometry with controlling for head size is useful in comparing the volumetric parameters and the surface area to a lesser extent in alcohol-related brain alteration.
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http://dx.doi.org/10.4306/pi.2016.13.5.511DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5067345PMC
September 2016

Early Activation of Phosphatidylinositol 3-Kinase after Ischemic Stroke Reduces Infarct Volume and Improves Long-Term Behavior.

Mol Neurobiol 2017 09 2;54(7):5375-5384. Epub 2016 Sep 2.

Department of Neurology, Hanyang University College of Medicine, Seoul, South Korea.

Phosphatidylinositol 3-kinases (PI3Ks) have recently been implicated in apoptosis and ischemic cell death. We tested the efficacy of early intervention with a peptide PI3K activator in focal cerebral ischemia. After determining the most effective dose (24 μg/kg) and time window (2 h after MCAO) of treatment, a total of 48 rats were subjected to middle cerebral artery occlusion (MCAO). Diffusion weighted MRI (DWI) was performed 1 h after MCAO and rats with lesion sizes within a predetermined range were randomized to either PI3K activator or vehicle treatment arms. Fluid attenuated inversion recovery (FLAIR) MRI, neurological function, western blots, and immunohistochemistry were blindly assessed. Initial DWI lesion volumes were nearly identical between two groups prior to treatment. However, FLAIR showed significantly smaller infarct volumes in the PI3K activator group compared with vehicle (146 ± 81 mm and 211 ± 96 mm, p = 0.045) at 48 h. The PI3K activator group also had better neurological function for up to 2 weeks. In addition, PI3K activator decreased the number of TUNEL-positive cells in the peri-infarct region compared with the control group. Western blot and immunohistochemistry showed increased expression of phosphorylated Akt (Ser473) and GSK-3β (Ser9) and decreased expression of cleaved caspase-9 and caspase-3. Our results suggest a neuroprotective role of early activation of PI3K in ischemic stroke. The use of DWI in the randomization of experimental groups may reduce bias.
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http://dx.doi.org/10.1007/s12035-016-0063-4DOI Listing
September 2017

Activation of the phosphatidylinositol 3-kinase pathway plays important roles in reduction of cerebral infarction by cilnidipine.

J Neurochem 2015 Oct 31;135(1):186-93. Epub 2015 Aug 31.

Department of Translational Medicine, Hanyang University Graduate School of Biomedical Science & Engineering, Seoul, Korea.

Cerebral infarction causes permanent neuronal loss inducing severe morbidity and mortality. Because hypertension is the main risk factor for cerebral infarction and most patients with hypertension take antihypertensive drugs daily, the neuroprotective effects and mechanisms of anti-hypertensive drugs need to be investigated. Cilnidipine, a long-acting, new generation 1,4-dihydropyridine inhibitor of both L- and N-type calcium channels, was reported to reduce oxidative stress. In this study, we investigated whether cilnidipine has therapeutic effects in an animal model of cerebral infarction. After determination of the most effective dose of cilnidipine, a total of 128 rats were subjected to middle cerebral artery occlusion. Neurobehavioral function test and brain MRI were performed, and rats with similar sized infarcts were randomized to either the cilnidipine group or the control group. Cilnidipine treatment was performed with reperfusion after 2-h occlusion. Western blots and immunohistochemistry were also performed after 24-h occlusion. Initial infarct volume on diffusion-weighted MRI was not different between the cilnidipine group and the control group; however, fluid-attenuated inversion recovery MRI at 24 h showed significantly reduced infarct volume in the cilnidipine group compared with the control group. Cilnidipine treatment significantly decreased the number of triphosphate nick end labeling-positive cells compared to the control group. Western blot and immunohistochemistry showed increased expression of phosphorylated Akt (Ser473), phosphorylated glycogen synthase kinase-3β, and Bcl-2 and decreased expression of Bax and cleaved caspase-3. These results suggest that cilnidipine, which is used for the treatment of hypertension, has neuroprotective effects in the ischemic brain through activation of the PI3K pathway. We investigated whether cilnidipine has neuroprotective effects on ischemic stroke in an animal model. We have demonstrated that the neuroprotective effect of cilnidipine is associated with the activation of the PI3K pathway. Considering the daily use of antihypertensive drugs for patients with hypertension, cilnidipine could be beneficial for patients with ischemic stroke.
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http://dx.doi.org/10.1111/jnc.13254DOI Listing
October 2015

Learning word sense disambiguation in biomedical text with difference between training and test distributions.

Int J Data Min Bioinform 2012 ;6(2):216-37

Department of Computer Engineering, Kyungpook National University, Daegu 702-701, Korea.

Word Sense Disambiguation methods based on machine learning techniques with lexical features suffer from the discordance between distributions of the training and test documents, due to the diversity of lexical space. To tackle this problem, this paper proposes Support Vector Machines with Example-wise Weights. In this method, the training distribution is matched with the test distribution by weighting training examples according to their similarity to all test data. The experimental results show the distribution change between the training and test data is actually recognised and the proposed method which considers this change in its training phase outperforms ordinary SVMs.
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http://dx.doi.org/10.1504/ijdmb.2012.048199DOI Listing
September 2012