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Title: Real-time ultrasonic assessment of progressive proteoglycan depletion in articular cartilage
Authors: Wang, Qing
Zheng, Yong-Ping
Qin, Ling
Huang, Qing-Hua
Lam, Wai Ling
Leung, Gina
Guo, Xia
Lu, Hong-Bin
Subjects: Articular cartilage
Proteoglycan depletion
Trypsin digestion
Issue Date: Jul-2008
Publisher: Elsevier for the World Federation for Ultrasound in Medicine and Biology
Source: Ultrasound in medicine and biology, July 2008, v. 34, no. 7, p. 1085-1092.
Abstract: The loss of proteoglycan (PG) is regarded as one of the early signs of osteoarthritis (OA), thus observing the progress of PG loss would be useful for the early detection of OA. In this study, high-frequency ultrasound was used to monitor and analyze the trypsin-induced progressive degeneration in articular cartilage. Full thickness cartilage-bone specimens (n = 10) prepared from normal bovine patellae were digested using 0.25% trypsin solution for different periods of time to evaluate the dynamics of the digestion process. The trypsin penetration front was observed in M-mode image, which was acquired using a nominal 50 MHz focused transducer. The transient speed of the digestion process was estimated from the image. The digestion fraction, which represents the ratio of the digestion depth to the total cartilage thickness, was estimated from ultrasound data and histology sections. With ultrasound, the digestion fraction observed in the 10 specimens ranged from 64% to 99% and was correlated to that measured by histology (R² ≥ 0.63, p < 0.05). It was found that the digestion speed decreased nonlinearly with depth from 0.61 ± 0.16 μm/s (mean ± SD) in the superficial zone to 0.04 ± 0.02 μm/s in a region located at 70% of the cartilage thickness in depth. The relationship between the digestion depth and the exposure duration in trypsin could be described using a third order polynomial function. The full thickness of digested and undigested tissues was also measured using caliper, estimated from ultrasound data and histology sections, and compared. These findings indicate that ultrasound could provide useful information about the trypsin-induced progressive PG depletion in articular cartilage. Therefore, ultrasound represents a useful tool to evaluate the dynamics of models of OA in vitro in cartilage specimens in a research environment and this would ultimately help the in vitro examination of articular cartilage for research related to model of OA from the early stages of tissue degradation.
Rights: Ultrasound in Medicine & Biology © 2008 World Federation for Ultrasound in Medicine & Biology. The journal web site is located at
Type: Journal/Magazine Article
DOI: 10.1016/j.ultrasmedbio.2007.12.006
ISSN: 0301-5629
Appears in Collections:HTI Journal/Magazine Articles
RS Journal/Magazine Articles

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