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Kenneth P. H. Pritzker – 1st expert on this subject based on the ideXlab platform
Calcium pyrophosphate dihydrate (CPPD) crystal dissolution by Alkaline Phosphatase: Interaction of Alkaline Phosphatase on CPPD crystalsJournal of Rheumatology, 1995Co-Authors: Tetsuya Shinozaki, Y Xu, T. F. Cruz, Kenneth P. H. PritzkerAbstract:
OBJECTIVE. As Alkaline Phosphatase (ALP) can dissolve calcium pyrophosphate dihydrate (CPPD) crystals, and as dissolution is facilitated when the enzyme is proximate to the crystals, we studied the mechanism of ALP interaction with CPPD crystals in vitro. METHODS. ALP was incubated with CPPD crystals in an in vitro model system. Fluorescein isothiocyanate conjugated Alkaline Phosphatase (FITC-ALP), Alkaline Phosphatase product staining of calcium pyrophosphate dihydrate (CPPD) crystals and scanning electron microscopy were used to visualize ALP-CPPD crystal interactions. RESULTS. ALP preferentially binds to the small end faces (optical 010 faces) of CPPD crystals. Etch pits indicative of dissolution were demonstrated coexistent with ALP crystal binding and ALP pyrophosphohydrolytic activity. CONCLUSION. ALP binding to CPPD crystals is preferential for the smallest end faces (optical 010 faces). As ALP crystal binding is altered by ions but not by heat inactivation of ALP, ALP-CPPD crystal binding is considered a nonenzymatic mechanism distinct from ALP pyrophosphohydrolytic activity. Our study demonstrates that ALP binds and dissolves CPPD crystals in a stereoselective manner. This suggests that the CPPD crystal dissolution rate is limited by the availability of surface area on the crystal faces most susceptible to ALP binding.
E.j. King – 2nd expert on this subject based on the ideXlab platform
Purification of placental Alkaline PhosphataseBiochimica et Biophysica Acta, 2003Co-Authors: Z. Ahmed, E.j. KingAbstract:
Abstract 1. 1. Alkaline Phosphatase has been prepared in a highly-purified form from human placental tissue. 2. 2. Two methods have been used for extracting the enzyme, i.e. the butanol extraction procedure of Morton and the acetone-toluene-ethylacetate autolysis procedures of Albers . 3. 3. The specific activity of Alkaline Phosphatase prepared by the butanol extraction method was 1150 King-Armstrong units/mg N, and that prepared by the autolysis method was 990 units. 4. 4. The highly concentrated Alkaline Phosphatase was further purified by paper electrophoresis. The resulting enzyme preparation had a Phosphatase activity of 1750 King-Armstrong units/mg N. This was less than was calculated to be present on the paper electrophoretic strip. But it was comparable with the highest activities obtained by other workers, when converted to their units by calculation. Placental tissue thus seems to have yielded as highly active a Phosphatase as other tissues previously studied. 5. 5. An attempt to purify Alkaline Phosphatase with an ion exchange resin (Dowex-2) was not successful.
Kinetics of placental Alkaline Phosphatase.Biochimica et Biophysica Acta, 2003Co-Authors: Z. Ahmed, E.j. KingAbstract:
Abstract The Alkaline Phosphatase of human placenta, prepared and purified as described in previous papers 1,2 hydrolyses β-glycerophosphate and phenyl at phosphate at nearly the same rate. The Alkaline Phosphatases of the kidney and the intestinal mucosa, on the other hand, hydrolyze phenyl phosphate much more rapidly than β-glocero-phosphate. The Michaelis-Menton constant, K m , for placental Alkaline Phosphatase is also different.
Joseph H Schwab – 3rd expert on this subject based on the ideXlab platform
prognostic value of serum Alkaline Phosphatase in spinal metastatic diseaseBritish Journal of Cancer, 2019Co-Authors: Aditya V Karhade, Quirina C B S Thio, Megna Kuverji, Paul T Ogink, Marco Ferrone, Joseph H SchwabAbstract:
Background Determination of the appropriateness of invasive management in patients with spinal metastatic disease requires accurate pre-operative estimation of survival. The purpose of this study was to examine serum Alkaline Phosphatase as a prognostic marker in spinal metastatic disease. Methods Chart reviews from two tertiary care centres were used to identify spinal metastatic disease patients. Bivariate and multivariate analyses were used to determine if serum Alkaline Phosphatase was an independent prognostic marker for survival. Results Overall, 732 patients were included with 90-day and 1-year survival of n = 539 (74.9%) and n = 324 (45.7%), respectively. The 1-year survival of patients in the first quartile of Alkaline Phosphatase (≤73 IU/L) was 78 (57.8%) compared to 31 (24.0%) for patients in the fourth quartile (>140 IU/L). Preoperative serum Alkaline Phosphatase levels were significantly elevated in patients with multiple spine metastases, non-spine bone metastasis, and visceral metastasis but not in patients with brain metastasis. On multivariate analysis, elevated serum Alkaline Phosphatase was identified as an independent prognostic factor for survival in spinal metastatic disease. Conclusion Serum Alkaline Phosphatase is associated with preoperative metastatic tumour burden and is a biomarker for overall survival in spinal metastatic disease.