Search Results

You are looking at 1 - 10 of 52 items

  • Author: J. A. van den Berg x
Clear All Modify Search
in Europe.

Summary

Suberin from extractive-free cork from Quercus suber L. was depolymerised by methanolysis using different sodium methanolate (NaOMe) concentrations. 1% and 3% NaOMe completely removed suberin from cork (54%–56% of extractive-free cork), but for lower concentrations there was incomplete solubilisation; with 0.05% NaOMe, only approximately 80% of total suberin was removed. The monomeric composition of the extracts differed significantly: for the 0.05% NaOMe, only alkanoic acids and diacids were found; the yield of v-hydroxy acids increased with reactant concentration, as well as alkanols and ferulic acid.

Results from light scattering, SEC and MALDI-MS showed that soluble oligomeric fragments containing suberinic acids were present in the methanolysis mixture. The molecular weight of these oligomeric fragments decreased with higher sodium methanolate concentrations.

Abstract

Background: Determination of the length of sedimentation reaction in blood (LSRB) is frequently used in daily practice to assess disease intensity. Recently, a micro-sedimentation method was introduced (TEST 1™) that uses EDTA anti-coagulated blood samples. The aim of this study was to characterize this method by comparing it to a conventional Westergren method (Sedimatic 100). Furthermore, correlation between fibrinogen and the LSRB and the influence of M-proteins on the LSRB was investigated.

Methods: Unselected paired samples were used for comparison between the TEST 1 and Sedimatic 100 methods (n=733); fibrinogen was measured in EDTA samples (n=765) using a turbidimetric method. Furthermore, LSRB was measured in 29 EDTA samples in paired serum tubes from patients in whom an M-protein was detected.

Results: TEST 1 showed excellent correlation with the Sedimatic 100 method (y=1.00x; n=733; r=0.92, 95% CI 0.90–0.93; p<0.0001), and had no significant bias (0.15mm/h, 95% CI –0.48 to 0.75mm/h). Furthermore, TEST 1 LSRB showed satisfactory correlation with the fibrinogen content (y=3.13+0.06x; n=765; r=0.78, 95% CI 0.75–0.80; p<0.0001). In samples containing M-proteins, satisfactory correlation between the M-protein content and TEST 1 LSRB was found (y=0.69+0.22x; n=29; r=0.71, 95% CI 0.45–0.85; p<0.0001), while excellent correlation was found when only M-proteins of the IgM type were taken into account (y=–0.95+0.23x; n=9; r=0.93, 95% CI 0.71–0.99; p<0.0002).

Conclusions: The results confirm previous reports that TEST 1 is a reliable method to measure the LSRB, and shows for the first time the quantitative relationship between TEST 1 LSRB and M-proteins, particularly those of the IgM type.

Clin Chem Lab Med 2006;44:904–6.