• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.368-373
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• 2009

A human tissue mimicking phantom is constructed to assess the performance of a medical ultrasound elasticity imaging system. In a human body, the tumor or cancer is stiffer than its surrounding normal tissue. A technique fur imaging the elasticity of such a tissue is referred to as elastography. Homogeneous elasticity phantoms with differing Young's moduli are constructed using a plastic hardener and softener to simulate the mechanical characteristics of a diseased human tissue. The Young's modulus of the fabricated homogeneous phantom materials were measured from 11.1 to 79.6 kPa depending on the mixing ratio of the amount of the hardener to that of the softener. An ultrasound lesion mimicking phantom was made of these materials, and ultrasound elasticity imaging was performed on it. It is confirmed in this paper that the fabricated plastic-based elasticity phantom is useful in representing the elastic characteristics of a human tissue.

• Korean Journal of Pharmacognosy
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• v.40 no.1
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• pp.6-12
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• 2009

Thirty five methanol extracts from 19 natural local plants, which have been used as traditional anti-cancer medicine, were prepared. They were analyzed the cytotoxic effects on primary fibroblast cells and carcinoma cells. The root extract of Solanum nigrum were highly toxic in both cell lines with $IC_{50}$ values of less than $0.01{\mu}g/{\mu}l$, and 26 of 35 extracts were toxic in all cells with $IC_{50}$ values of $0.1{\sim}2{\mu}g/{\mu}l$. Three extracts including the fruit extracts of Solanum nigrum and Morus alba had no cytotoxic activity in both cell lines. Five of 35 extracts were highly toxic in cancer cells than in primary cells. Because primary cells were more resistant on these extracts, the five extracts were selected for anti-cancer agent candidates. Apoptosis or programmed cell death has an essential role in chemotherapy-induced tumor cell killing. Recently, inducers of apoptosis have been used in cancer therapy. When two of 5 cancer cell-specific cytotoxic extracts (Ulmus parvifolia and Zelkova serrata) were treated in concentration of $0.02{\sim}0.1{\mu}g/{\mu}l$, apoptosis were increased at 3-5 times in cancer cell lines. Finally, the apoptotic effects of these extracts were confirmed by cleavages of both poly-(ADP-ribose)-polymerase and caspase-3 as apoptotic markers. In this report, we suggested that two of 35 medicinal herb extracts can be useful anti-cancer drug candidates inducing apoptosis in several carcinoma cell lines.

• Journal of Life Science
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• v.24 no.5
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• pp.573-587
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• 2014

Angiogenesis, the formation of new capillary blood vessels, is a tightly regulated process. Under normal physiological conditions, angiogenesis only takes place during embryonic development, wound healing, and female menstruation. Dysregulation of angiogenesis is associated with many diseases, such as cancer, rheumatoid arthritis, psoriasis, and proliferative retinopathy. The growth and expansion of adipose tissue require the formation of new blood vessels. Adipose tissue is probably the most highly vascularized tissue in the body, as each adipocyte is surrounded by capillaries, and the angiogenic vessels supply nutrients and oxygen to adipocytes. Accumulating evidence shows that capillary endothelial cells communicate with adipocytes via paracrine signaling pathways, extracellular components, and direct cell-cell interactions. Activated adipocytes produce multiple angiogenic factors, including VEGF, FGF-2, leptin, and HGF, which either alone or cooperatively stimulate the expansion and metabolism of adipose tissue by increasing adipose tissue vasculature. Recently, it was demonstrated that antiangiogenic herbal Ob-X extracts and Korean red ginseng extracts reduce adipose tissue mass and suppress obesity by inhibiting angiogenesis in obese mice. Thus, angiogenesis inhibitors provide a promising therapeutic approach for controlling human obesity and related disorders.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.471-476
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• 2007

Various active microwave imaging techniques have been developed for cancer detection for past several decades. Both the microwave tomography and the UWB radar techniques, constituting functional microwave imaging systems, use the electrical property contrast between normal tissues and malignancies to detect the latter in an early development stage. Even though promising simulation results have been reported, the understanding of the functional microwave imaging diagnostics has been relied heavily on the complicated numerical results. We present a computationally efficient and physically instructive analytical electromagnetic wave channel models developed for functional microwave imaging system in order to detect especially the breast tumors as early as possible. The channel model covers the propagation factors that have been examined in the previous 2-D models, such as the radial spreading, path loss, partial reflection and transmission of the backscattered electromagnetic waves from the tumor cell. The effects of the system noise and the noise from the inhomogeneity of the tissue to the reconstruction algorithm are modeled as well. The characteristics of the reconstructed images of the tumor using the proposed model are compared with those from the confocal microwave imaging.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.689-700
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• 2022

In the present study, iodine-131 S values (r_T ← thyroid) were calculated for 30 target organs and tissues using the most recently developed Korean reference computational phantoms. The calculated S values were then compared with those of the International Commission on Radiological Protection (ICRP) reference computational phantoms to investigate the dosimetric impact of the Korean S values against those of the ICRP reference phantoms. The results showed significant differences in the S values due to the different anatomical/morphological characteristics between the Korean and ICRP reference phantoms. Most target organs/tissues showed that the S values of the Korean reference phantoms are lower than those of the ICRP reference phantoms, by up to about 4 times (male spleen and female thymus). Exceptionally, three target organs/tissues (gonads, thyroid, and extrathoracic region) showed that the S values of the Korean reference phantoms are greater, by 1.5-3.7 times. We expect that the S values calculated in the present study will be beneficially used to estimate organ/tissue doses of Korean patients under radioiodine therapy.

• BMB Reports
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• v.42 no.6
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• pp.344-349
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• 2009

Angiogenesis is crucial for solid tumor growth. By secreting angiogenic factors, tumor cells induce angiogenesis. However, targeting these angiogenic factors for cancer therapy is not always successful, suggesting that other factors may be involved in tumor angiogenesis. This work shows that 25 protein spots were differentially expressed by two-dimensional gel electrophoretic analysis when HepG2 cells induced endothelial cell differentiation to tube in vitro, and most of them were upregulated. Twenty-one proteins were identified with MALDITOF-MS, and the other four were identified by LTQ-MS/MS. Keratins were identified as one class of these upregulated proteins. Further study indicated that the expression of keratin 17 in cultured endothelial cells is likely microenvironment regulated, because its expression can be induced by HepG2 cells and bFGF as well as serum in culture media. Increased expression of keratins in endothelial cells, such as keratin 17, may contribute to the angiogenesis induced by HepG2 cells.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1272-1274
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• 2013

• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.14-17
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• 1995

An in vitro construct of three dimensional artificial skin equivalent has been engineered using human cervical epithelial cells and human foreskin fibroblasts with a matrix of bovine type I collagen. Two cell lines were established from cervical uteri cancer tissues which have the HPV(human papillomavirus)18 genome. These two cell lines came from the same origin but have slight differencies in growth rate and tumorigenicity. The organotypic raft culturing of epithelial cells were accomplished at air-liquid interface. The differentiation related characteristics were examined by immunohistochemistry using monoclonal antibodies against EGFreceptor, cytokeratin 5/6/18 as proliferation markers and against filaggrin, involucrin, and cytokeratin 10/13 as differentiation marker. We have obtained the stratification and the differentiation in the artificial skin equivalent, and differentiation-related proteins were expressed more in the C3-artificial skin, and proteins of proliferation were expressed more in the C3N-artificial skin, relatively. We found that reconstituted artificial skin have the same characteristics of differentiation proteins of original tissue or cells of human body.

• International Journal of Stem Cells
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• v.17 no.1
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• pp.15-29
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• 2024

The development and differentiation of endothelial cells (ECs) are fundamental processes with significant implications for both health and disease. ECs, which are found in all organs and blood vessels, play a crucial role in facilitating nutrient and waste exchange and maintaining proper vessel function. Understanding the intricate signaling pathways involved in EC development holds great promise for enhancing vascularization, tissue engineering, and vascular regeneration. Hematopoietic stem cells originating from hemogenic ECs, give rise to diverse immune cell populations, and the interaction between ECs and immune cells is vital for maintaining vascular integrity and regulating immune responses. Dysregulation of vascular development pathways can lead to various diseases, including cancer, where tumor-specific ECs promote tumor growth through angiogenesis. Recent advancements in single-cell genomics and in vivo genetic labeling have shed light on EC development, plasticity, and heterogeneity, uncovering tissue-specific gene expression and crucial signaling pathways. This review explores the potential of ECs in various applications, presenting novel opportunities for advancing vascular medicine and treatment strategies.

• Progress in Medical Physics
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• v.30 no.1
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• pp.7-13
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• 2019

Purpose: To compare the dosimetrical and radiobiological parameters among various volumetric modulated arc therapy (VMAT) techniques using restricted and continuous arc beams for left-sided breast cancer. Materials and Methods: Ten patients with left-sided breast cancer without regional nodes were retrospectively selected and prescribed the dose of 42.6 Gy in 16 fractions on the planning target volume (PTV). For each patient, three plans were generated using the $Eclipse^{TM}$ system (Varian Medical System, Palo Alto, CA) with one partial arc 1pVMAT, two partial arcs 2pVMAT, and two tangential arcs 2tVMAT. All plans were calculated through anisotropic analytic algorithm and photon optimizer with 6 MV photon beam of $VitalBEAM^{TM}$. The same dose objectives for each plan were used to achieve a fair comparison during optimization. Results: For PTV, dosimetrical parameters such as Homogeneity index, conformity index, and conformal number were superior in 2pVMAT than those in both techniques. $V_{95%}$, which indicates PTV coverage, was 91.86%, 96.60%, and 96.65% for 1pVMAT, 2pVMAT, and 2tVMAT, respectively. In most organs at risk (OARs), 2pVMAT significantly reduced the delivered doses compared with the other techniques, excluding the doses to contralateral lung. For the analysis of radiobiological parameters, a significant difference in normal tissue complication probability was observed in ipsilateral lung while no difference was observed in the other OARs. Conclusions: Our study showed that 2pVMAT had better plan quality and normal tissue sparing than 1pVMAT and 2tVMAT but not for all parameters. Therefore, 2pVMAT could be considered the priority choice for the treatment planning for left breast cancer.