• Annals of Clinical Neurophysiology
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• v.18 no.1
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• pp.18-20
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• 2016

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron degenerative disease that clinically manifests both upper and lower motor neuron signs. However, it is unknown where and how the motor neuron degeneration begins, and conflicting hypotheses have been suggested. Recent advanced radiological techniques enable us to look into ALS neuropathology in vivo. Herein, we report a case with upper motor neuron-predominant ALS in whom the results of brain magnetic resonance imaging (MRI) and myelin water fraction MRI suggest axonal degeneration.

• Journal of Korean Neurosurgical Society
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• v.61 no.4
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• pp.434-440
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• 2018

Objective : The purpose of this study was to find an optimal delivery route for clinical trials of intrathecal cell therapy for spinal cord injury in preclinical stage. Methods : We compared in vivo distribution of Cy5.5 fluorescent dye in the spinal cord region at various time points utilizing in vivo optical imaging techniques, which was injected into the lateral ventricle (LV) or cisterna magna (CM) of rats. Results : Although CM locates nearer to the spinal cord than the LV, significantly higher signal of Cy5.5 was detected in the thoracic and lumbar spinal cord region at all time points tested when Cy5.5 was injected into the LV. In the LV injection Cy5.5 signal in the thoracic and lumbar spinal cord was observed within 12 hours after injection, which was maintained until 72 hours after injection. In contrast, Cy5.5 signal was concentrated at the injection site in the CM injection at all time points. Conclusion : These data suggested that the LV might be suitable for preclinical injection route of therapeutics targeting the spinal cord to test their treatment efficacy and biosafety for spinal cord diseases in small animal models.

• International Journal of Stem Cells
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• v.16 no.1
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• pp.93-107
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• 2023

Background and Objectives: Chronic periodontitis can lead to alveolar bone resorption and eventually tooth loss. Stem cells from exfoliated deciduous teeth (SHED) are appropriate bone regeneration seed cells. To track the survival, migration, and differentiation of the transplanted SHED, we used super paramagnetic iron oxide particles (SPIO) Molday ION Rhodamine-B (MIRB) to label and monitor the transplanted cells while repairing periodontal bone defects. Methods and Results: We determined an appropriate dose of MIRB for labeling SHED by examining the growth and osteogenic differentiation of labeled SHED. Finally, SHED was labeled with 25 ㎍ Fe/ml MIRB before being transplanted into rats. Magnetic resonance imaging was used to track SHED survival and migration in vivo due to a low-intensity signal artifact caused by MIRB. HE and immunohistochemical analyses revealed that both MIRB-labeled and unlabeled SHED could promote periodontal bone regeneration. The colocalization of hNUC and MIRB demonstrated that SHED transplanted into rats could survive in vivo. Furthermore, some MIRB-positive cells expressed the osteoblast and osteocyte markers OCN and DMP1, respectively. Enzyme-linked immunosorbent assay revealed that SHED could secrete protein factors, such as IGF-1, OCN, ALP, IL-4, VEGF, and bFGF, which promote bone regeneration. Immunofluorescence staining revealed that the transplanted SHED was surrounded by a large number of host-derived Runx2- and Col II-positive cells that played important roles in the bone healing process. Conclusions: SHED could promote periodontal bone regeneration in rats, and the survival of SHED could be tracked in vivo by labeling them with MIRB. SHED are likely to promote bone healing through both direct differentiation and paracrine mechanisms.

• Journal of Sensor Science and Technology
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• v.21 no.3
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• pp.217-222
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• 2012

Optical coherence tomography(OCT) is a noninvasive optical imaging tool for biomedical applications. OCT can provide depth resolved two/three dimensional morphological images on biological samples. In this paper, we integrated an OCT system that was composed of an SLED(Superluminescent Light Emitting Diode, ${\lambda}_0$=1305 nm bandwith= 141 nm), a reference arm adopting a rapid scanning optical delay line(RSOD) to get high speed imaging, and a sample arm that used a micro electro mechanical systems(MEMS) scanning mirror. The sample arm contained a compact probe for imaging dental structures. The performance of the system was evaluated by imaging in-vivo human teeth with dental calculus, and the results indicated distinct appearance of dental calculus from enamel, gum or decayed teeth. The developed probe and system could successfully confirm the presence of dental calculus with a very high spatial resolution($6{\mu}m$).

• Investigative Magnetic Resonance Imaging
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• v.22 no.1
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• pp.37-49
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• 2018

Purpose: The effect of global inhomogeneity on quantitative susceptibility mapping (QSM) was investigated. A technique referred to as Simultaneous Unwrapping Phase with Error Recovery from inhomogeneity (SUPER) is suggested as a preprocessing to QSM to remove global field inhomogeneity-induced phase by polynomial fitting. Materials and Methods: The effect of global inhomogeneity on QSM was investigated by numerical simulations. Three types of global inhomogeneity were added to the tissue susceptibility phase, and the root mean square error (RMSE) in the susceptibility map was evaluated. In-vivo QSM imaging with volunteers was carried out for 3.0T and 7.0T MRI systems to demonstrate the efficacy of the proposed method. Results: The SUPER technique removed harmonic and non-harmonic global phases. Previously only the harmonic phase was removed by the background phase removal method. The global phase contained a non-harmonic phase due to various experimental and physiological causes, which degraded a susceptibility map. The RMSE in the susceptibility map increased under the influence of global inhomogeneity; while the error was consistent, irrespective of the global inhomogeneity, if the inhomogeneity was corrected by the SUPER technique. In-vivo QSM imaging with volunteers at 3.0T and 7.0T MRI systems showed better definition in small vascular structures and reduced fluctuation and non-uniformity in the frontal lobes, where field inhomogeneity was more severe. Conclusion: Correcting global inhomogeneity using the SUPER technique is an effective way to obtain an accurate susceptibility map on QSM method. Since the susceptibility variations are small quantities in the brain tissue, correction of the inhomogeneity is an essential element for obtaining an accurate QSM.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1890-1894
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• 2012

Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) have been implicated in the pathogenesis of rheumatoid arthritis, which is angiogenesis dependent. Antibody-based molecular imaging improves targeting, and antibody radiolabeling is useful for monitoring biological events $in$ $vivo$ $via$ PET or SPECT. We investigated the potential of molecular imaging to diagnose arthritis with VEGFR-2 $in$ $vivo$. The $^{123}I$-VEGFR-2 antibody was prepared by the iodogen tube method. The radioligand was injected into arthritic mice, and micro SPECT/CT was performed. The arthritic mice were examined by 4.7-T MRI and immunohistochemistry. The $^{123}I$-VEGFR-2 antibody showed high uptake in the arthritic region at 1 h postinjection on SPECT/CT but no uptake in the control animals after radioligand injection. In MR images, the arthritic tissue of the mice was correlated with regions labeled by the $^{123}I$-VEGFR-2 antibody. Immunohistochemical localization showed markedly increased expression of VEGFR-2 in the endothelial cells, fibroblasts, and macrophages of the arthritic mice.

• Journal of the Optical Society of Korea
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• v.15 no.1
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• pp.61-67
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• 2011

The confocal laser scanning microscopy and two-photon microscopy was implemented based on a single laser source and an objective lens. We imaged and compared the morphology of identical sites of ex vivo human skin using both microscopes. The back-scattering emission from the sample provided the contrast for the confocal microscopy. The intrinsic autofluorescence and the second harmonic generation were used as the luminescence source for the two-photon microscopy. The wavelength of the Ti:Sapphire laser was tuned at 710 nm, which corresponds to the excitation peak of NADH and FAD in skin tissue. The various cell layers in the epidermis and the papillary dermis were clearly distinguished by both imaging modalities. The two-photon microscopy more clearly visualized the intercellular region and the nucleus of the cell compared to the confocal microscopy. The fibrous structures in the dermis were more clearly resolved by the confocal microscopy. Numerous cells in papillary dermal layer, as deep as $100\;{\mu}m$, were observed in both CLSM and two-photon microscopy. While most previous studies focused on fibrous structure imaging (collagen and elastin fiber) in the dermis, we demonstrated that the combined imaging with the CLSM and two-photon microscopy can be applied for the non-invasive study of the population, distribution and metabolism of papillary dermal cells in skin.

• The Korean Journal of Nuclear Medicine
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• v.18 no.2
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• pp.77-85
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• 1984

Monoclonal antibodies have become widely investigated in the Nuclear Oncology, especially in the radioimmunosassay of tumor markers and in vivo radioimmunoimaging of cancer. However, there are numerous factors as to whether radioimmunoimaging will ultimately successful. For imaging of tumors, metallic radionuclides such as In-111, Ga-67, Tc-99m have favorable nuclear properties than widely used I-131. These radioistopes have characteristics of the useful radiation for imaging, convenient short half-lives and the simple and rapid radiolabeling of monoclonal antibodies by using bifunctional chelaing agents. The obtained chelate-tagged antibodies are quite stable both in vitro and in vivo, without interfering antibody activities and animal experiments provided a good basis for its clinical applicability for the radioimmunoimaging of cancer. Much attention has also been given to the possibility, only beginning to be exploited, of the specific treatment of malignant neoplasms with these agents. Although specific antibody has not been developed that is uniquely specific for cancer alone and there are still many questions to be answered and problems to be overcome before radioimmunoimaging can be successfully used in ptients with cancer, these methods can be applied to the coupling of monoclonal antibodies with anti-neoplastic drugs or radionuclides suitable for internal radiation therapy of cancer.

• Current Optics and Photonics
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• v.7 no.2
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• pp.176-182
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• 2023

Optical coherence tomography (OCT) is being developed to guide various ophthalmic surgical procedures. However, the high cost of the intraoperative OCT system limits its availability mostly to the largest hospitals and healthcare systems. In this paper, we present a design and evaluation of a low-cost intraoperative common-path free-hand scanning OCT system. The lensed fiber imaging probe is designed and fabricated for intraocular use and the free-hand scanning algorithm that could operate at a low scanning speed was developed. Since the system operates at low frequencies, the cost of the overall system is significantly lower than other commercial intraoperative OCT systems. The assembled system is characterized and shows that it meets the design specifications. The handheld OCT imaging probe is tested on multilayer tape phantom and ex-vivo porcine eyes. The results show that the system could be used as an intraoperative intraocular OCT imaging device.

• Biomaterials and Biomechanics in Bioengineering
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• v.3 no.3
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• pp.129-140
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• 2016

This article reports the development of biodegradable photoluminescent polymer (BPLP)-based nanoparticles (NPs) incorporating either magnetic nanoparticles (BPLP-MNPs) or gadopentate dimeglumine (BPLP-Gd NPs), for cancer diagnosis and treatment. The aim of the study is to compare these nanoparticles in terms of their surface properties, fluorescence intensities, MR imaging capabilities, and in vitro characteristics to choose the most promising dual-imaging nanoprobe. Results indicate that BPLP-MNPs and BPLP-Gd NPs had a size of $195{\pm}43nm$ and $161{\pm}55nm$, respectively and showed good stability in DI water and 10% serum for 5 days. BPLP-Gd NPs showed similar fluorescence as the original BPLP materials under UV light, whereas BPLP-MNPs showed comparatively less fluorescence. VSM and MRI confirmed that the NPs retained their magnetic properties following encapsulation within BPLP. Further, in vitro studies using HPV-7 immortalized prostate epithelial cells and human dermal fibroblasts (HDFs) showed > 70% cell viability up to $100{\mu}g/ml$ NP concentration. Dose-dependent uptake of both types of NPs by PC3 and LNCaP prostate cancer cells was also observed. Thus, our results indicate that BPLP-Gd NPs would be more appropriate for use as a dual-imaging probe as the contrast agent does not mask the fluorescence of the polymer. Future studies would involve in vivo imaging following administration of BPLP-Gd NPs for biomedical applications including cancer detection.