| 1. |
- Choi, Hyun-Ju
(författare)
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Image analysis for quantifying microvessel density in renal cell carcinoma
- 2009
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Ingår i: Journal of Korea Society of Medical Informatics. - : The Korean Society of Medical Informatics. - 1225-8903. ; 15:2, s. 217-225
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Tidskriftsartikel (refereegranskat)abstract
- The most widely used method for quantifying new blood vessel growth in tumor angiogenesis is the determination of microvessel density, which is reported to be associated with tumor progression and metastasis, and a prognostic indicator of patient outcome. In this study, we propose a method for the determination of microvessel density by image analysis, to improve the accuracy and the objectivity of determination of the microvessel density. Four-micron-thick tissue sections of renal cell carcinoma samples were stained immunohistochemically for CD34. The regions with a high degree of vascularization were selected by an expert for digitization. Each image was digitized as a 24-bits/pixel image file with a resolution of 640×480 pixels. First, segmentation of the microvessels based on pixel classification using color features in hybrid color space was performed. After use of a correction process for microvessels with discontinuities and separation of touching microvessels, we counted the number of microvessels for the microvessel density measurement. The result was evaluated by comparison with manual quantification of the same images. The comparison revealed that our computerized microvessel quantification was highly correlated with manual counting by a pathologist. The results indicate that our method is better than the conventional computerized image analysis methods.
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| 2. |
- Jo, Ji Song, et al.
(författare)
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Anti-wrinkle activity of beta-carotene extracted & purified from recombinant Escherichia coli
- 2008
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Ingår i: KSBB Journal. - 1225-7117 .- 2288-8268. ; 23:6, s. 513-518
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Tidskriftsartikel (refereegranskat)abstract
- This paper described the extraction/purification of β-carotene from recombinant E.coli and evaluation of anti-wrinkle activity of purified β-carotene. No significant differences in extraction yields were observed when hexane or isobutyl acetate was used. However, extraction from wet-cell cake resulted in 2-fold higher amount of β-carotene than that from dry cells. Disruption of 5 g-wet cells by ultrasonic homogenizer, acetone dehydration, extraction with isobutyl acetate resulted in 36 mg of β-carotene corresponding to 61.2% of recovery. The formation and separation of ββ-carotene crystal improved the purity. 633 mg of β-carotene crystal with 93% purity was obtained from 223 g/L of wet-cell cake harvested from 2.5-L fed-batch culture broth. The cultures of normal human primary fibroblast were performed to investigate the effect of β-carotene on cytotoxicity as MTT assay and anti-wrinkle activity as collagen synthesis assays. 1.7μM of β-carotene was found to be optimal concentration at which 1.4-fold higher amount of collagen was synthesized than that in absence of β-carotene. This indicates that highly purified β-carotene can be obtained from recombinant E.coli by applying simple method with less toxic solvent and can be used in functional cosmetics as anti-wrinkle agent.
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