• Journal of Convergence Korean Medicine
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• v.2 no.1
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• pp.13-22
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• 2021

Objectives: Atopic dermatitis (AD) is an easily recurrent inflammatory skin disease. Since AD has complex pathology, people have been investigating it on different aspects with various experimental models. One of them is in vivo model which has spontaneously developed AD-like skin lesions by various inducers. Methods: In this study, two kinds of mouse species were applied in the experiment; BALB/c and C57BL/6 mice. We compared features among the animal species making AD mouse model with protein allergen, ovalbumin. AD-like skin lesions were induced by ovalbumin on two kinds of scheme and were evaluated with the histological results and size of spleen which is a critical immunological organ. Also, we measured the level of immunoglobulin E in serum. In addition, we investigated the results of ovalbumin induced-AD-like skin lesions along with obesity. Results and Conclusion: We evaluated weight of organs and thickness of epidermis. These results suggest the possibility of the appropriate in vivo experimental model for AD or the comorbidity with obesity.

• Korean Journal of Computational Design and Engineering
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• v.15 no.4
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• pp.297-305
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• 2010

Medical image acquisition techniques such as CT and MRI have disadvantages in that the numerous time and efforts are needed. Furthermore, a great amount of radiation exposure is an inherent proberty of the CT imaging technique, a number of side-effects are expected from such method. To improve such conventional methods, a number of novel methods that can obtain 3D medical images from a few X-ray images, such as algebraic reconstruction technique (ART), have been developed. Such methods deform a generic model of the internal body part and fit them into the X-ray images to obtain the 3D model; the initial shape, therefore, affects the entire fitting process in a great deal. From this fact, we propose a novel method that can generate a 3D vertebraic generic model based on the statistical database of CT scans in this study. Moreover, we also discuss a method to generate patient-tailored generic model using the facts obtained from the statistical analysis. To do so, the mesh topologies of CT-scanned 3D vertebra models are modified to be identical to each other, and the database is constructed based on them. Furthermore, from the results of a statistical analysis on the database, the tendency of shape distribution is characterized, and the modeling parameters are extracted. By using these modeling parameters for generating the patient-tailored generic model, the computational speed and accuracy of ART can greatly be improved. Furthermore, although this study only includes an application to the C1 (Atlas) vertebra, the entire framework of our method can be applied to other body parts generally. Therefore, it is expected that the proposed method can benefit the various medical imaging applications.

• Advances in biomechanics and applications
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• v.1 no.3
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• pp.169-185
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• 2014

Computational multibody models of the elbow can provide a versatile tool to study joint mechanics, cartilage loading, ligament function and the effects of joint trauma and orthopaedic repair. An efficiently developed computational model can assist surgeons and other investigators in the design and evaluation of treatments for elbow injuries, and contribute to improvements in patient care. The purpose of this study was to develop an anatomically correct elbow joint model and validate the model against experimental data. The elbow model was constrained by multiple bundles of non-linear ligaments, three-dimensional deformable contacts between articulating geometries, and applied external loads. The developed anatomical computational models of the joint can then be incorporated into neuro-musculoskeletal models within a multibody framework. In the approach presented here, volume images of two cadaver elbows were generated by computed tomography (CT) and one elbow by magnetic resonance imaging (MRI) to construct the three-dimensional bone geometries for the model. The ligaments and triceps tendon were represented with non-linear spring-damper elements as a function of stiffness, ligament length and ligament zero-load length. Articular cartilage was represented as uniform thickness solids that allowed prediction of compliant contact forces. As a final step, the subject specific model was validated by comparing predicted kinematics and triceps tendon forces to experimentally obtained data of the identically loaded cadaver elbow. The maximum root mean square (RMS) error between the predicted and measured kinematics during the complete testing cycle was 4.9 mm medial-lateral translational of the radius relative to the humerus (for Specimen 2 in this study) and 5.30 internal-external rotation of the radius relative to the humerus (for Specimen 3 in this study). The maximum RMS error for triceps tendon force was 7.6 N (for Specimen 3).

• Journal of mucopolysaccharidosis and rare diseases
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• v.4 no.1
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• pp.26-36
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• 2018

Mucopolysaccharidosis IIIA is a heritable neurodegenerative disorder resulting from the dysfunction of the lysosomal hydrolase sulphamidase. This leads to the primary accumulation of the complex carbohydrate heparan sulphate in a wide range of tissues and CNS degeneration. Characterization of animal model is the beginning point of the therapeutic clinical trial. Mouse model has a limitation in that it is not a human and does not have all of the disease phenotypes. Therefore, delineate of the phenotypic characteristics of MPS IIIA mouse model prerequisite for the enzyme replace treatment for the diseases. We designed 6-month duration of phenotypic characterization of MPS IIIA mouse biochemically, behaviorally and histologically. We compared height and weight of MPS IIIA mouse with wild type from 4 weeks to 6 months in both male and female. At 6 months, we measured GAG storage in urine kidney, heart, liver, lung and spleen. The brain GAG storage is presented with Alcian blue staining, immunohistochemistry, and electron-microscopy. The neurologic phenotype is evaluated by brain MRI and behavioral study including open field test, fear conditioning, T-maze test and Y-maze test. Especially behavioral tests were done serially at 4month and 6month. This study will show the result of the MPS IIIA mouse model phenotypic characterization. The MPS IIIA mouse provides an excellent model for evaluating pathogenic mechanisms of disease and for testing treatment strategies, including enzyme or cell replacement and gene therapy.

• Journal of Digital Contents Society
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• v.17 no.6
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• pp.603-611
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• 2016

Generally, the doctors manually delineated the prostate boundary seeing the image by their eyes, but the manual method not only needed quite much time but also had different boundaries depending on doctors. To reduce the effort like them the automatic delineating methods are needed, but detecting the boundary is hard to do since there are lots of uncertain textures or speckle noises. There have been studied in SVM, SIFT, Gabor texture filter, snake-like contour, and average-shape model methods. Besides, there were lots of studies about 2 and 3 dimension images and CT and MRI. But no studies have been developed superior to human experts and they need additional studies. For this, this paper proposes a method that delineates the boundary predicting its texture features and its average distribution on the prostate image. As result, we got the similar boundary as the method of human experts.

• Journal of Biomedical Engineering Research
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• v.29 no.2
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• pp.99-106
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• 2008

To improve $B_1$ homogeneity in high field MRI, the RF power is applied to the transmit array coil elements sequentially in the time-multiplexed way. Since only a single coil element is activated in a time-multiplexing slot, the global standing wave formation in the human body is greatly suppressed. The time-multiplexing slot width is on the order of micro seconds, hence, high-order-harmonic slices can be placed far from the transmit coil and simultaneous multiple slice selection can be avoided. The $B_1$ homogeneities of a birdcage coil and an eight-channel transmit array coil have been compared through finite difference time domain simulations. The simulation results indicate that the proposed technique can reduce the peak-to-peak $B_1$ inhomogeneity down to one fourth of the transmission with a birdcage coil on the central plane of the human head model at 3 T. The mimicking experiments at 3 T, eight separate experiments with a single coil element activated and image reconstruction by combining the eight images, also show promising results. It is expected that the proposed technique has some advantages over other $B_1$ improving methods in real practice since simple RF switching circuitries are only necessary and electromagnetic coupling between the coil elements is out of concern in its realization.

• Korean Journal of Cognitive Science
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• v.18 no.4
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• pp.399-415
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• 2007

Many objects are always present in a visual scene. Since the visual system has limited capacity to process multiple stimuli at a time, how to cope with this informational overload is one of the important problems to solve in visual perception. This study investigated the suppressive interactions among multiple stimuli when attention was directed to either one of the stimuli or all of them. The results indicate that suppressive interactions among multiple circles were reduced in V4 when subjects paid attention to one of the four locations, as compared to the unattended condition. However, suppressive interactions were not reduced when they paid attention to all four items as a set, in order to compute their mean size. These results suggest that whereas focused attention serves to later out irrelevant information, distributed attention provides an average representation of multiple stimuli.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.517-523
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• 2011

Anterior cruciate ligament (ACL) injuries are treatedwith surgical reconstruction. Although ACL consists of two functional bundles, only the anteromedial bundle is surgically reconstructed, and the effect of the reconstruction of the posterolateral bundle is unknown. The purpose of this study is to investigate the role of the posterolateral bundle and the effect of double-bundle reconstruction during single-leg landing. A 3D dynamic knee with various ACL reconstructed models was created using MRI, and single-leg landing motion was simulated using in-vivo human experimental data. The results showed that the lateral shift of the tibial insertion of the anteromedial bundle and the posterolateral bundle of the ACL constrain the tibial internal rotation more efficiently than a single anteromedial bundle can. In addition, double-bundle ACL reconstruction is less sensitive to inaccuracies in the tibial tunnel placement.

• Journal of Ginseng Research
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• v.31 no.3
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• pp.159-174
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• 2007

Pharmacology of Korean Red ginseng gives us unique possibility to develop new class of antiepileptic drugs today and to improve one's biological activity. The chemical structures of ginsenosides (GS) have some principal differences from well-known antiepileptic new generation drugs. The antiepileptic effect of GS was also demonstrated in all models of epilepsy in rats (young and adult), which have studied, in all models of epilepsy including status epilepticus (SE), induced by lithium - pilocarpine. In our experiments in rats new evidences on protective effects were exerted as a result of premedication by GS. Pre-treatment of several GS could induce decrease of the seizures severity and brain structural damage (by MRI), neuronal degeneration in hippocampus. Wave nature of severity of motor seizures during convulsive SE was observed during lithium-pilocarpine model of SE in rats (the first increase of seizures was 30 min after the beginning of SE and the second - 90 min after. The efficacy of treatment on SE by ginsenoside as expected was observed after no less 3 weeks by daily GS i.p. administration. It is blocked SE or significantly decrease the severity of seizures during SE. The implication of presented data is that combination of ginsenosides from Korean Red ginseng and ginseng cell culture Dan25 that could be applied for prevention of epileptical status development. However, a development of optimal ratio of different ginsenosides $(Rb_1$ Rc, Rg, Rf,) should consummate in the new antiepileptic drug development.

• Investigative Magnetic Resonance Imaging
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• v.25 no.2
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• pp.118-128
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• 2021

Purpose: To investigate the value of MR textural analysis, including use of diffusion-weighted imaging (DWI) to differentiate malignant from benign soft-tissue tumors on 3T MRI. Materials and Methods: We enrolled 69 patients (25 men, 44 women, ages 18 to 84 years) with pathologically confirmed soft-tissue tumors (29 benign, 40 malignant) who underwent pre-treatment 3T-MRI. We calculated MR texture, including mean, standard deviation (SD), skewness, kurtosis, mean of positive pixels (MPP), and entropy, according to different spatial-scale factors (SSF, 0, 2, 4, 6) on axial T1- and T2-weighted images (T1WI, T2WI), contrast-enhanced T1WI (CE-T1WI), high b-value DWI (800 sec/mm²), and apparent diffusion coefficient (ADC) map. We used the Mann-Whitney U test, logistic regression, and area under the receiver operating characteristic curve (AUC) for statistical analysis. Results: Malignant soft-tissue tumors had significantly lower mean values of DWI, ADC, T2WI and CE-T1WI, MPP of ADC, and CE-T1WI, but significantly higher kurtosis of DWI, T1WI, and CE-T1WI, and entropy of DWI, ADC, and T2WI than did benign tumors (P < 0.050). In multivariate logistic regression, the mean ADC value (SSF, 6) and kurtosis of CE-T1WI (SSF, 4) were independently associated with malignancy (P ≤ 0.009). A multivariate model of MR features worked well for diagnosis of malignant soft-tissue tumors (AUC, 0.909). Conclusion: Accurate diagnosis could be obtained using MR textural analysis with DWI and CE-T1WI in differentiating benign from malignant soft-tissue tumors.