• BMB Reports
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• v.57 no.6
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• pp.273-280
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• 2024

Cancer cells metastasize to distant organs by altering their characteristics within the tumor microenvironment (TME) to effectively overcome challenges during the multistep tumorigenesis. Plasticity endows cancer cell with the capacity to shift between different morphological states to invade, disseminate, and seed metastasis. The epithelial-to-mesenchymal transition (EMT) is a theory derived from tissue biopsy, which explains the acquisition of EMT transcription factors (TFs) that convey mesenchymal features during cancer migration and invasion. On the other hand, adherent-to-suspension transition (AST) is an emerging theory derived from liquid biopsy, which describes the acquisition of hematopoietic features by AST-TFs that reprograms anchorage dependency during the dissemination of circulating tumor cells (CTCs). The induction and plasticity of EMT and AST dynamically reprogram cell-cell interaction and cell-matrix interaction during cancer dissemination and colonization. Here, we review the mechanisms governing cellular plasticity of AST and EMT during the metastatic cascade and discuss therapeutic challenges posed by these two morphological adaptations to provide insights for establishing new therapeutic interventions.

• Journal of radiological science and technology
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• v.16 no.2
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• pp.19-26
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• 1993

Magnetic Resonance Image represents three-dimensional diagnostic imaging technique using both nuclear magnetic resonance phenomenon and computer. Compared with computed tomography (CT), MRI have advantages harmless to patient's body, three-dimensional image with high resolution and disadvantages long data acquisition time because of long T1 relaxation time, relatively low signal to noise ratio, high cost of setting, also. As physiologic motion of tissue results in motion ghost in MRI, high 2.0Tesla make improve low signal to noise ratio. This study have aim to improve image quality with controling motion ghost of tissue. Supposing a moving pixel in constant frequency, one pixel make two ghosts which are same size and different anti-phase. So, this study will show adjust parameter on locational control of motion ghost. Author made moving phantom replaced by respiratory movement of human, researched change of motion frequency, FOV by location shift, and them decided optimal FOV (field of view). The results are as follows: 1. The frequency content of the motion determines how far the image always appear in phase-encoding direction, the morphology of the ghost image is characteristic of the direction of the motion and its amplitude. 2. Double FOV of fixed signal object for locational control of motion ghost is recommended. Decreasement of spatial resolution by increasing FOV can compensate on increasing of matrix in spite of scan time increasement.

• Journal of Korean Foot and Ankle Society
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• v.7 no.2
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• pp.208-217
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• 2003

Introduction: Soft-tissue impingement syndrome is now increasingly recognized as a significant cause of the chronic ankle pain. As a method to detect soft-tissue ankle impingement, a characteristic history and physical examination, routine MR imaging, and direct MR arthrography were used. The efficacy of routine MR imaging has been controversial for usefulness because of low sensitivity and specificity. Direct MR artrhography was recommaned for diagnosis because of the highest sensitivity, specificity and accuracy, but it requires an invasive procedure. The purpose of this study is to investigate the diagnostic accuracy of Fat suppressed, contrast enhanced, three-dimensional fast gradient recalled acquisition in the steady state with rediofrequency spoiling magnetic resonance imaging(CE 3D-FSPGR MRI) and to evaluate the clinical outcome of the arthroscopic treatment in assessing soft-tissue impingement associated with trauma of the ankle. Materials and Methods: We reviewed 38 patients who had arthroscopic evaluations and preoperative magnetic resonance imaging studies(3D-FSPGR MRI) for post-traumatic chronic ankle pain between January 2000 and August 2002. Among them, 24 patients had osteochondral lesion, lateral instability, loose body, malunion of lateral malleoli, and peroneal tendon dislocation. The patient group consisted of 23 men and 15 women with the average age of 34 years(16-81 years). The mean time interval from the initial trauma to the operation was 15.5 months(3 to 40 months), The mean follow-up duration of the assessment was 15.6months(12-48 months). MRI was simultaneously reviewed by two radiologists blinded to the clinical diagnosis. The sensitivity, specificity and accuracy of MRI was obtained from radiologic and arthroscopic finding. Arthroscopic debridement and additional operation for associated disease were performed. We used a standard protocol to evaluate patients before the operation and at follow-up which includes American Orthopedic Foot and Ankle Society Ankle-Hindfoot Score. Results: For the assessment of the synovitis and soft tissue impingement, fat suppressed CE 3D-FSPGR MR imaging had the sensitivity of 91.9%, the specificity of 84.4 and the accuracy of 87.5%. AOFAS Ankle-Hindfoot Score of preoperative state was 69.2, and the mean score of the last follow-up was 89.1. These were assessed as having 50% excellent(90-100) and 50% good(75-89). The presence of other associated disease didn't show the statistically significant difference(>0.05). Conclusion: Fat suppressed CE 3D-FSPGR MR imaging is useful method comparable to MR arthrography for diagnosis of synovitis or soft-tissue impingement, and arthroscopic debridement results in good clinical outcome.

• Journal of Photoscience
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• v.9 no.2
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• pp.457-459
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• 2002

Sunlight causes various types of adverse skin changes on the sun-exposed areas of the skin, in which the most hazardous one is the induction of malignant skin tumours. FT -IR spectra were obtained from specimens excised from normal skin, BCCs, SCCs, MMs, nevi, lesions of solar keratosis and Bowen's disease. Tissue samples from freshly frozen specimens were cut into 2 sections in strictly sequential order to be stained with H & E for histopathological analysis, and then to be air-dried on CaF$_2$ slide glasses for further spectral data acquisition from defined area of interest. Intra- and inter-sample variations were estimated within grouped lesion categories according to each skin component. Mean spectra for each type of tissue pathology in the 800-1800 $cm^{-1}$ / region was interpreted using the classical group frequency approach that showed the most visible differences in spectra of benign, premalignant and malignant changes directly related to protein conformation and nucleic acid bases. The relative intensity of the nucleic acid peak was increased with progression to malignancy. In addition, PCA was able to evaluate and maximise the differences in the spectra by reducing the number of variables characterizing each patient and pathology category. This type of approach to non-destructively estimate the complexity of IR-spectra of inhomogeneous samples such as skin demonstrates the advantage of FT -IR microspectroscopy to be able to observe diseased states (benign, premalignant, malignant) and distinguish them from normal against a huge background of inter- and intra-subject variability.

• Korean Journal Plant Pathology
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• v.10 no.3
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• pp.211-214
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• 1994

Paulowina witches'-broom mycoplasma-like organism (PWB-MLO) was transmitted experimentally to periwinkle (Catharanthus roseus L.) plant by tobacco leaf bug (Cyrtopeltis tenuis Reuter). Adults of the leaf bugs were allowed to feed on the witch's-broom infected paulownia (Paulownia tomentoas Steud.) trees for three weeks to insure the acquisition of PWB-MLO and then transferred to healthy seedlings of periwinkle and paulownia plants. In 25∼35 days after transfer of the viruliferous leaf bugs, six out of the ten periwinkle plants showed‘little-leaf’symptoms, while the paulowina seedlings remained symptomless. Presence of MLO in the infected periwinkle tissue was diagnosed by fluorescence microscopy and MLO particles were observed under electron microscope, confirming the transmission of PWB-MLO to periwinkle.

• Journal of Biomedical Engineering Research
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• v.8 no.2
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• pp.171-176
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• 1987

Wiener filtering method was applied to the dual energy imaging procedure in digital radiography(D.R.). A linear scanning photodiode arrays with 1024 elements(0.6mm H 1.3mm pixel size) were used to obtain chest images in 0.7 sec. For high energy image acquisition, X-ray tube was set at 140KVp, 100mA with a rare-earth phosphor screen. Low energy image was obtained with X-ray tube setting at 70KVp, 150mA. These measured dual energy images are represented in the vector matrix notation as a linear discrete model including the additive random noise. Then, the object images are restored in the minimum mean square error sense using Wiener filtering method in the transformed domain. These restored high and low energy images are used for computation of the basis image decomposition. Then the basis images are linearly combined to produce bone or tissue selective images. Using this process, we could improve the signal to noise ratio characteristics in the material selective images.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.64-67
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• 1992

To improve signal-to-noise ratio in sodium image, short echo time (2-3 ms) and long data acquisition (10-20 ms) protocols are used. Sodium in biological specimens demonstrates a bi-exponential decay of transverse magnetization and the fast decaying component of the sodium signal results in the reconstruction of images which are blurred significantly. The spatially-dependent nature of the blurs are due mainly to the presence of short local transverse relaxation values (0.7-3 ms) of sodium in tissue. We present an algorithm that corrects for object-dependent blurs due to fast-decaying T2 and improves the computational behavior of the algorithm by incorporating a relaxation parameter into the iterative process.

• BMB Reports
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• v.48 no.11
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• pp.599-608
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• 2015

Regeneration, a process of reconstitution of the entire tissue, occurs throughout life in the olfactory epithelium (OE). Regeneration of OE consists of several stages: proliferation of progenitors, cell fate determination between neuronal and non-neuronal lineages, their differentiation and maturation. How the differentiated cell types that comprise the OE are regenerated, is one of the central questions in olfactory developmental neurobiology. The past decade has witnessed considerable progress regarding the regulation of transcription factors (TFs) involved in the remarkable regenerative potential of OE. Here, we review current state of knowledge of the transcriptional regulatory networks that are powerful modulators of the acquisition and maintenance of developmental stages during regeneration in the OE. Advance in our understanding of regeneration will not only shed light on the basic principles of adult plasticity of cell identity, but may also lead to new approaches for using stem cells and reprogramming after injury or degenerative neurological diseases.

• Journal of radiological science and technology
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• v.20 no.1
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• pp.29-34
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• 1997

For radiological test in soft tissue or neighboring part with same signal intensity, proper test method and equipment shall be selected as needed. In case of female pelvic cavity, ultrasonography or computed tomography alternatively used, but MRI can be more usefully applied to design treatment method or operation plan by improving the diagnostic accuracy and careful observation of lesion characteristics. Magnetic Resonance Imaging using recently developed Enteral MRI contrast media can acquire more diagnostic information than using only intravenous contrast media. Thus this study attempted to examine the utility of anatomic structure and diagnostic acquisition by imaging the female pelvic cavity using Enteral MRI contrast media. As a result of analyzing magnetic resonance Imaging after administering Enteral MRI contrast media to pelvic cavity suspect patients, more diagnostic information media could be acquired than only using Intravenous contrast. Expecially, in the diagnosis of lesion position, shape, distinction from neighboring tissues it is thought that external Enteral MRI contrast media should be used.

• ETRI Journal
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• v.31 no.2
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• pp.237-239
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• 2009

A whole-body voxel model of a 7-year-old male volunteer was developed from 384 axial magnetic resonance images (MRIs). The MRIs were acquired with intervals of 3 mm for the entire body in a body coil. In order to reduce the MRI acquisition time for the child, the repetition and echo times under T1 weighted image were chosen to be 566 ms and 8 ms, respectively. The MRIs were classified according to 30 types of tissues with known electrical parameters. The developed voxel model was adjusted to the physical average of 7-year-old Korean boys. The body weight of the adjusted model, calculated with the mass tissue densities, is within a 6% difference from the 50th percentile weight.