Improved colorimetric determination of high-molecular weight hyaluronic acid from synovial fluids

1989 ◽  
Vol 333 (8) ◽  
pp. 810-817 ◽  
Author(s):  
Horst Kutsch ◽  
Christine Schleich
1992 ◽  
Vol 57 (10) ◽  
pp. 2151-2156 ◽  
Author(s):  
Peter Chabreček ◽  
Ladislav Šoltés ◽  
Hynek Hradec ◽  
Jiří Filip ◽  
Eduard Orviský

Two methods for the preparation of high molecular weight [3H]hyaluronic acid were investigated. In the first one, hydrogen atoms in the molecule were replaced by tritium. This isotopic substitution was performed in aqueous solution using Pd/CaCO3 as the catalyst. In the second method, the high molecular weight hyaluronic acid was alkylated with [3H]methyl bromide in liquid ammonia at a temperature of -33.5 °C. High-performance gel permeation chromatographic separation method was used for the isolation and characterization of the high molecular weight [3H]hyaluronic acid. Molecular weight parameters for the labelled biopolymers were Mw = 128 kDa, Mw/Mn = 1.88 (first method) and Mw = 268 kDa, Mw/Mn = 1.55 (second method). The high molecular weight [3H]hyaluronic acid having Mw = 268 kDa was degraded further by specific hyaluronidase. Products of the enzymatic depolymerization were observed to be identical for both, labelled and cold biopolymer. This finding indicates that the described labelling procedure using [3H]methyl bromide does not induce any major structural rearrangements in the molecule.


2016 ◽  
Vol 8 (3) ◽  
pp. 19
Author(s):  
Choaping Ng ◽  
Felicity J Rose ◽  
Sahar Keshvari ◽  
Marina M Reeves ◽  
Goce Dimeski ◽  
...  

<p>Adiponectin is a beneficial adipocyte-secreted hormone, which circulates in a variety of multimeric forms termed low and high molecular weight (LMW/HMW). Effectiveness of clinical therapeutic trials which target adiponectin rely on accurate determination of circulating total and HMW adiponectin levels but the accuracy may be influenced by variations in sample handling processes. The aim of this pilot study was to investigate the effects of delayed processing of blood samples on the concentration of total and HMW adiponectin.</p><p>Materials and Methods: Fasting blood samples were collected for analysis of total and HMW adiponectin concentrations in EDTA plasma and serum from eight healthy participants.  Samples were centrifuged post 15 min storage at 4<sup>o</sup>C as the comparative ‘ideal’ method or after up to 72 h of refrigerated storage or 6 h at room temperature. Total and HMW adiponectin concentrations were measured by ELISA.</p><p>Results: Under ideal handling conditions measurements of total and HMW adiponectin concentrations were significantly higher in serum than in plasma (mean difference: -1.3 µg/mL [95% CI: -1.6, -1.0], p&lt;0.001; and, -0.6 µg/mL [95% CI: -0.7, -0.5], p&lt;0.001, respectively).  Storage of blood samples at 4<sup>o</sup>C for 72 h resulted in significant reductions in concentration of total adiponectin in serum (mean difference: -1.4 µg/mL [95% CI: -2.0, -0.8], p=0.001) and HMW adiponectin in plasma (mean difference: -0.6 µg/mL [95%CI: -0.9, -0.2], p=0.007), compared with ideal conditions.  Further analysis of serum samples showed a significant decrease in total adiponectin concentration after 6 h storage at 4<sup>o</sup>C (mean difference: -1.4 µg/mL [95% CI: -2.0, -0.8], p=0.001) compared with ideal conditions.</p><p>Conclusions: Delayed processing of samples may have differential effects on the concentration of total and HMW adiponectin in serum or plasma. Larger studies are warranted for clinical intervention trials.</p>


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