Modulation of Osteogenic Differentiation of Adipose-Derived Stromal Cells by Co-Treatment with 3, 4’-Dihydroxyflavone, U0126, and N-Acetyl Cysteine

Background and Objectives@#Flavonoids form the largest group of plant phenols and have various biological and pharma-cological activities. In this study, we investigated the effect of a flavonoid, 3, 4’-dihydroxyflavone (3, 4’-DHF) on osteogenic differentiation of equine adipose-derived stromal cells (eADSCs). @*Methods@#and Results: Treatment of 3, 4’-DHF led to increased osteogenic differentiation of eADSCs by increasing phosphorylation of ERK and modulating Reactive Oxygen Species (ROS) generation. Although PD98059, an ERK inhibitor, suppressed osteogenic differentiation, another ERK inhibitor, U0126, apparently increased osteogenic differentiation of the 3, 4’-DHF-treated eADSCs, which may indicate that the effect of U0126 on bone morphogenetic protein signaling is involved in the regulation of 3, 4’-DHF in osteogenic differentiation of eADSCs. We revealed that 3, 4’-DHF could induce osteogenic differentiation of eADSCs by suppressing ROS generation and co-treatment of 3, 4’-DHF, U0126, and/or N-acetyl cysteine (NAC) resulted in the additive enhancement of osteogenic differentiation of eADSCs. @*Conclusions@#Our results showed that co-treatment of 3, 4’-DHF, U0126, and/or NAC cumulatively regulated osteo-genesis in eADSCs, suggesting that 3, 4’-DHF, a flavonoid, can provide a novel approach to the treatment of osteoporosis and can provide potential therapeutic applications in therapeutics and regenerative medicine for human and companion animals.

A Case of Achieving Complete Remission with Stereotactic Body Radiation Therapy in Patients with Hepatocellular Carcinoma with Macrovascular Invasion after Repeated Transarerial Chemoembolization

Transarterial chemoembolization (TACE) is the worldwide procedure performed for patients with various stage hepatoceullar carcinoma (HCC), but is not yet considered as curative treatment because of relatively high local recurrence rate. Moreover, many clinicians frequently experience treatment failure (incomplete necrosis or stage progression etc.) after repeated TACE, but no clear guidelines have been recommended about salvage treatment modalities for this situation. Recently, studies for combination of radiation therapy and TACE for HCC with TACE refractoriness have been tried and reported better therapeutic efficacy. Based on above suggestions, we herein offer our experience of a patient with macrovascular invasion developed after repeated TACE that achieve complete remission by stereotactic body radiation therapy. Further study, maybe regarding a combination of locoregional and systemic therapy, is necessary on how to manage HCC patients with TACE refractoriness.

A Case of Achieving Complete Remission with Combination of Stereotac-tic Body Radiation Therapy and Transarterial Chemoemoblization in Pa-tients with 4.8 cm Sized Infiltrative Hepatocellular Carcinoma with Arte-riovenous Shunt

Infiltrative hepatocellular carcinoma (HCC) patients have a poor prognosis because most patients present with advanced disease. Although tumor size is small, ablation therapy is difficult because it is difficult to delineate tumor boundary and tumor often combined vascular invasion. Therefore many clinicians still try locoregional therapy (LRT) such as transarterial chemoembolization (TACE), radiation therapy (RT), or combination with LRT and sorafenib in this situation. Stereotactic body radiation therapy (SBRT) is new technology providing very highly conformal ablative radiation dose and is expected to salvage modality for HCC showed incomplete response of TACE due to combined arteriovenous (AV) shunts. Based on above suggestions, we herein offer our experience of a complete remission of tumor by combination of SBRT and TACE in a patient with infiltrative HCC. Further study, maybe regarding a combination of locoregional and systemic therapy is necessary on how to manage infiltrative HCC with AV shunts.

Feasibility Study of Vertical Multileaf Collimator for Determination of Irradiation Size / 의학물리

The purpose of this study was to evaluate feasibility of Vertical Multileaf Collimator for determination of irradiation size using Vertical Multileaf Collimator and lead block to determine 4 different irradiation shape in case of Co-60 gamma-ray and 6 MV X-ray. We chose ion chamber, glass dosimeter and EBT chromic film to compare with Vertical Multileaf Collimator results and lead block results. In case of Co-60 gamma-ray and 6 MV X-ray, the central axis point dose normalized at reference field of lead block with ion chamber results for Vertical Multileaf Collimator were estimated higher than lead block about 5.1%, 4.2%. In case of Co-60 gamma-ray, the central axis point dose normalized at reference field of lead block with glass dosimeter results for Vertical Multileaf Collimator were estimated higher than lead block about 2.2%, 7.8%, 7.2%, 4.0% for reference, circle, triangle, cross field, respectively. In case of 6 MV X-ray, the central axis point dose normalized at reference field of lead block with glass dosimeter results for Vertical Multileaf Collimator were estimated higher than lead block about 6.7%, 6.2%, 3.8%, 6.2% for reference, circle, triangle, cross field, respectively. The results of EBT chromic film, Vertical Multileaf Collimator of penumbra size for all irradiation shape was smaller than lead block of those size that 2.0~3.5 mm for Co-60 gamma-ray, 0.5~1.0 mm for 6 MV X-ray. The results from this study, radiation treatment volume that results in shielding block can be minimized. In addition, during radiation treatment for 2, 3-dimensional radiation therapy using a Vertical Multileaf Collimator of this survey can be used to determine variety of irradiation fields.