• Journal of Biomedical and Translational Research
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• v.19 no.4
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• pp.110-115
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• 2018

Transient ischemic attack (TIA) indicates high risk for major stroke and is considered a medical emergency. Diffusion-weighted imaging (DWI) enables detection of acute ischemic lesions. The clinical significance of DWI positive lesions in TIA is obscure and its prevalence, clinical features are not established. Therefore, we performed a clinical, etiological and prognostic analysis through a cross-sectional analysis of 235 TIA patients, grouped according to presence of DWI lesion. Clinical features, underlying risk factors for stroke, outcome and rate of recurrence were analyzed. 3 months follow-up of modified Rankin Scales (mRS) were done with telephone survey. DWI positive lesions were present in 14.0% of patients. Etiological factors significantly associated with DWI lesions in TIA patients were male sex (p = 0.038), stroke history (p = 0.012) and atrial fibrillation (p < 0.001). Presence of at least one medium or high risk of cardioembolism from TOAST classification were not associated with lesions when excluding association to atrial fibrillation (p = 0.108). Clinical features showed no significant difference. Whether the patients had lesion-positive DWI was not related to an increase in mRS score during the hospital stay or at the 3-month follow-up after discharge. Future studies should include multi-center samples with large numbers, considering each unique medical environment. Routine acquisition of follow-up DWI for proper evaluation of the tissue-based definition of TIA should also be considered.

• Clinical Endoscopy
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• v.56 no.3
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• pp.367-374
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• 2023

Background/Aims: Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) using oblique-view EUS in patients with a surgically altered anatomy (SAA) of the upper gastrointestinal tract is limited because of difficult scope insertion due to the disturbed anatomy. This study aimed to investigate the efficiency of forward-view (FV)-EUS in performing FNA in patients with a SAA. Methods: We retrospectively investigated 32 patients with a SAA of the upper gastrointestinal tract who visited Aichi Cancer Center Hospital in Nagoya, Japan, between January 2014 and December 2020. We performed upper gastrointestinal EUS-FNA using FV-EUS combined with fluoroscopic imaging to confirm tumor recurrence or to make a decision before chemotherapy or after a failure of diagnosis by radiology. Results: We successfully performed EUS-FNA in all studied patients (100% technical success), with the specificity, sensitivity, and accuracy of 100%, 87.5%, and 87.8%, respectively, with no complications. Conclusions: EUS-FNA using FV-EUS combined with fluoroscopic imaging is an effective and safe technique for tissue acquisition in patients with a SAA.

• Journal of Cardiovascular Imaging
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• v.31 no.2
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• pp.71-82
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• 2023

BACKGROUND: Cardiac magnetic resonance fingerprinting (cMRF) enables simultaneous mapping of myocardial T1 and T2 with very short acquisition times. Breathing maneuvers have been utilized as a vasoactive stress test to dynamically characterize myocardial tissue in vivo. We tested the feasibility of sequential, rapid cMRF acquisitions during breathing maneuvers to quantify myocardial T1 and T2 changes. METHODS: We measured T1 and T2 values using conventional T1 and T2-mapping techniques (modified look locker inversion [MOLLI] and T2-prepared balanced-steady state free precession), and a 15 heartbeat (15-hb) and rapid 5-hb cMRF sequence in a phantom and in 9 healthy volunteers. The cMRF_5-hb sequence was also used to dynamically assess T1 and T2 changes over the course of a vasoactive combined breathing maneuver. RESULTS: In healthy volunteers, the mean myocardial T1 of the different mapping methodologies were: MOLLI 1,224 ± 81 ms, cMRF_15-hb 1,359 ± 97 ms, and cMRF_5-hb 1,357 ± 76 ms. The mean myocardial T2 measured with the conventional mapping technique was 41.7 ± 6.7 ms, while for cMRF_15-hb 29.6 ± 5.8 ms and cMRF_5-hb 30.5 ± 5.8 ms. T2 was reduced with vasoconstriction (post-hyperventilation compared to a baseline resting state) (30.15 ± 1.53 ms vs. 27.99 ± 2.07 ms, p = 0.02), while T1 did not change with hyperventilation. During the vasodilatory breath-hold, no significant change of myocardial T1 and T2 was observed. CONCLUSIONS: cMRF_5-hb enables simultaneous mapping of myocardial T1 and T2, and may be used to track dynamic changes of myocardial T1 and T2 during vasoactive combined breathing maneuvers.

• Journal of radiological science and technology
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• v.29 no.4
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• pp.249-255
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• 2006

Purpose: The diagnostic utility of fluorine-18 2-deoxy-D-glucose positron emission tomograhpy ($^{18}F-FDG $PET) for the non-invasive differentiation of focal lung lesions originated from cancer or inflammation disease by combined visual image interpretation and semi-quantitative uptake value analysis has been documented. In general, Standardized Uptake Value(SUV) is used to diagnose lung disease. But SUV does not contain dynamic information of lung tissue for the glucose. Therefore, this study was undertaken to hypothesis that analysis of dynamic kinetics of focal lung lesions base on $^{18}F-FDG$ PET may more accurately determine the lung disease. So we compared Time Activity Curve(TAC), Standardized Uptake Value-Dynamic Curve(SUV-DC) graph pattern with Glucose Metabolic Rate(MRGlu) from Patlak analysis. Methods: With lung disease, 17 patients were examined. They were injected with $^{18}F-FDG$ over 30-s into peripheral vein while acquisition of the serial transaxial tomographic images were started. For acquisition protocol, we used twelve 10-s, four 30-s, sixteen 60-s, five 300-s and one 900-s frame for 60 mins. Its images were analyzed by visual interpretation TAC, SUV-DC and a kinetic analysis(Patlak analysis). The latter was based on region of interest(ROIs) which were drawn with the lung disease shape. Each optimized patterns were compared with itself. Results: In TAC patterns, it hard to observe cancer type with inflammation disease in early pool blood area but over the time cancer type slope more remarkably increased than inflammation disease. SUV-DC was similar to TAC pattern. In the result of Patlak analysis, In time activity curve of aorta, even though inflammation disease showed higher blood activity than cancer, at first as time went by, blood activity of inflammation disease became the lowest. However, in time activity curve of tissue, cancer had the highest uptake and inflammation disease was in the middle. Conclusion: Through the examination, TAC and SUV-DC could approached the results that lung cancer type and inflammation disease type has it's own difference shape patterns. Also, it has outstanding differentiation between cancer type and inflammation in Patlak and MRGlu analysis. Through these analysis methods, it will helpful to separation lung disease.

• Progress in Medical Physics
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• v.12 no.1
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• pp.51-58
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• 2001

Synchrotron radiation (SR) has several advantages over convetional x-rays, including its phase, collimation, and high flux. A synchrotron radiation beamline 5C1 at Pohang Light Source (PLS) was recently built for imaging applications. We have shown that a SR imaging system is useful in imaging microscopic structures. SR with broad-band energy spectrum were adjusted to an object by Si wafers and their energy were approximately ranging from 6 keV to 30 keV. SR were passed through an object and finally transformed into visible lights by CdWO$_4$ scintillator screen. The visible lights which were reflected at an angle of 90 degrees by gold plated mirror were detected by a CCD camera and the image data were acquired using image acquisition system. A high-resolution phantom, capacitor, adult tooth, child tooth, cancerous breast tissue, and mouse lumbar vertebra were imaged with SR imaging system. The Objects were rotated within the field of view of the CCD detector, and their projection image data were obtained at 250 steps over 180 degrees rotation. Image reconstructions were carried out in a PC by using IDLTM(Research systems, Inc., US) program. The spatial resolution of the images acquired by the SR imaging system was measured with a high-resolution chart manufactured for several micrometer resolution. The specimens were also imaged with conventional x-ray radiography system to compare the image quality of radiography obtained with the SR imaging system. The results showed more structural details and high contrast images with SR imaging system than conventional x-ray radiography system. The SR imaging system may have a potential for imaging in biological researches, material applications, and clinical radiography.

• The Korean Journal of Blood Transfusion
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• v.23 no.2
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• pp.115-126
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• 2012

Background: Umbilical cord (UC) is a promising source of mesenchymal stromal cells (MSCs). We compared the characteristics of MSCs from cryopreserved UC with those from fresh tissues, and demonstrated the possibility of UC cryopreservation for acquisition of MSCs from cryopreserved UC. Methods: Each UC was sliced into two types ($1{\sim}2mm^3$ vs. 0.5 cm), and cryopreserved in liquid nitrogen using different media (autologous cord blood plasma, aCBP vs. RPMI 1640). A fresh aliquot of $1{\sim}2mm^3$-sized UC was used as control tissue. After one week, the cryopreserved tissues were thawed and cultured. For the 0.5 cm UC, a slicing step into $1{\sim}2mm^3$ was needed. Cell count, viability, proliferative activity, and surface antigens were determined from harvested MSCs. Several growth factors (EGF, IGF-1, PDGF, TGF-${\beta}$, bFGF, and VEGF), were measured from the culture supernatant. Results: Eleven UC were enrolled in the study. Efficiencies of obtaining MSCs were higher in cryopreserved UC using RPMI 1640, compared with use of aCBP; the same result was observed for 0.5 cm sized UC, compared with $1{\sim}2mm^3$ sized UC. No difference in proliferative activity was observed between MSCs from fresh and cryopreserved UC. The amount of growth factors in culture supernatant using RPMI 1640 was larger than that of fresh tissues. Conclusion: We obtained growth factors from the supernatant as well as MSCs from cryopreserved UC. As with a cord blood bank, in the future, cryopreservation of UC for acquisition of both MSCs and growth factors would be possible in a time of need.

• Tuberculosis and Respiratory Diseases
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• v.75 no.3
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• pp.95-103
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• 2013

Background: Small cell lung cancer (SCLC) transformation during epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in lung cancer has been suggested as one of possible resistance mechanisms. Methods: We evaluated whether SCLC transformation or neuroendocrine (NE) differentiation can be found in the cell line model. In addition, we also investigated its effect on responses to conventional chemotherapeutic drugs of the SCLC treatment. Results: Resistant cell lines to various kinds of EGFR-TKIs such as gefitinib, erlotinib, CL-387,785 and ZD6474 with A549, PC-9 and HCC827 lung adenocarcinoma cell lines were established. Among them, two resistant cell lines, A549/GR (resistant to gefitinib) and PC-9/ZDR (resistant to ZD6474) showed increased expressions of CD56 while increased synaptophysin, Rb, p16 and poly(ADP-ribose) polymerase were found only in A549/GR in western blotting, suggesting that NE differentiation occurred in A549/GR. A549/GR cells were more sensitive to etoposide and cisplatin, chemotherapeutic drugs for SCLC, compared to parental cells. Treatment with cAMP and IBMX induced synaptophysin and chromogranin A expression in A549 cells, which also made them more sensitive to etoposide and cisplatin than parental cells. Furthermore, we found a tissue sample from a patient which showed increased expressions of CD56 and synaptophysin after development of resistance to erlotinib. Conclusion: NE differentiation can occur during acquisition of resistance to EGFR-TKI, leading to increased chemosensitivity.

• Journal of Korean Neurosurgical Society
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• v.61 no.3
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• pp.363-375
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• 2018

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal age-adjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.

• The Journal of Advanced Prosthodontics
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• v.6 no.5
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• pp.379-386
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• 2014

PURPOSE. These days, mesenchymal stem cells (MSCs) have received worldwide attention because of their potentiality in tissue engineering for implant dentistry. The purpose of this study was to evaluate various growth inducing factors in media for improvement of acquisition of bone marrow mesenchymal stem cells (BMMSCs) and colony forming unit-fibroblast (CFU-F). MATERIALS AND METHODS. The mouse BMMSCs were freshly obtained from female C3H mouse femur and tibia. The cells seeded at the density of $10^6$/dish in media supplemented with different density of fetal bovine serum (FBS), $1{\alpha}$, 25-dihydroxyvitamin (VD3) and recombinant human epidermal growth factor (rhEGF). After 14 days, CFU-F assay was conducted to analyze the cell attachment and proliferation, and moreover for VD3, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was additionally conducted. RESULTS. The cell proliferation was increased with the increase of FBS concentration (P<.05). The cell proliferation was highest at the density of 20 ng/mL rhEGF compared with 0 ng/mL and 200 ng/mL rhEGF (P<.05). For VD3, although the colony number was increased with the increase of its concentration, the difference was not statistically significant (P>.05). CONCLUTION. FBS played the main role in cell attachment and growth, and the growth factor like rhEGF played the additional effect. However, VD3 did not have much efficacy compare with the other two factors. Improvement of the conditions could be adopted to acquire more functional MSCs to apply into bony defect around implants easily.

• Journal of Plant Biotechnology
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• v.37 no.1
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• pp.12-24
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• 2010

Plant metabolomics is a research field for identifying all of the metabolites found in a certain plant cell, tissue, organ, or whole plant in a given time and conditions and for studying changes in metabolic profiling as time goes or conditions change. Metabolomics is one of the most recently developed omics for holistic approach to biology and is a kind of systems biology. Metabolomics or metabolite fingerprinting techniques usually involves collecting spectra of crude solvent extracts without purification and separation of pure compounds or not in standardized conditions. Therefore, that requires a high degree of reproducibility, which can be achieved by using a standardized method for sample preparation and data acquisition and analysis. In plant biology, metabolomics is applied for various research fields including rapid discrimination between plant species, cultivar and GM plants, metabolic evaluation of commercial food stocks and medicinal herbs, understanding various physiological, stress responses, and determination of gene functions. Recently, plant metabolomics is applied for characterization of gene function often in combination with transcriptomics by analyzing tagged mutants of the model plants of Arabidopsis and rice. The use of plant metabolomics combined by transcriptomics in functional genomics will be the challenge for the coming year. This review paper attempted to introduce current status and prospects of plant metabolomics research.