Determination and application of asphaltene property distributions for native and refined crude oils
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2012
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Abstract
Osteoarthritis is a degenerative joint disease involving the breakdown of articular cartilage, which is common after injury or with aging. Cartilage lubrication is a vital mechanism for the protection and maintenance of joints. Proteoglycan 4 (PRG4), a glycoprotein present in synovial fluid (SF), contributes to the boundary lubrication of cartilage and maintenance of the joint. PRG4 also acts synergistically with hyaluronan (HA), another molecule present in SF, as cartilage boundary lubricants. The objective of this thesis was to determine 1) PRG4 and HA concentration, 2) HA molecular weight (MW) distribution, 3) cartilage lubricating ability, and 4) the isoelectric point (pl) of PRG4 in SF from surgical sham (SHAM), anterior cruciate ligament (ACL)/medial collateral ligament (MCL) transection, and lateral meniscectomy (MEN) in a post-knee injury ovine model at 20 weeks. SHAM (n=S), ACL/MCL transection (n=6), and MEN (n=S) ovine SF ( oSF) was collected at euthanization 20 weeks after surgery, with the left joint serving as the non-operative control (CTRL). PRG4 and HA concentration in oSF was measured by a sandwich enzyme-linked immunosorbent assay (ELISA) and HA MW distribution by agarose gel electrophoresis. A cartilage-cartilage friction test under boundary lubrication conditions was used to assess the cartilage lubricating ability of oSF. The pl of PRG4 was determined by twodimensional (2D) gel electrophoresis. PRG4 and HA concentration in SHAM, ACL/MCL, and MEN oSF was similar in comparison to the contralateral CTRL oSF. The HA MW distribution in the SHAM, ACL/MCL, and MEN oSF for all ranges were similar with respect to the contralateral CTRL oSF. The kinetic coefficient of friction in phosphate buffered saline was si nificantly higher than all groups, both operated, CTRL oSF, and bovine SF in all cases, which was lower and similar. The pl of PRG4 is ~4.0-4.4 and the pl of PRG4 may have shifted to a higher pl in MEN oSF, in compared to contralateral CTRL oSF. These results suggest that lubricant composition and function was normal 20 weeks post-knee surgery in this model and 2D electrophoresis may provide insight into the structure of PRG4 glycosylations.
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Bibliography: p. 97-104
Many pages are in colour.
Many pages are in colour.
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Citation
Barrera, D. M. (2012). Determination and application of asphaltene property distributions for native and refined crude oils (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/5052