Determination of specific proteins by the FIA principle

The following analytes have been investigated: urine albumin (u-albumin), plasma-transferrin (p-transferrin), p-haptoglobin, p-IgG, p-IgA, p-IgM, and p-orosomucoid. An unmodified commercial analytical system FIA Star (Tecator) with a two-channel injector (40 μl) was used. The prediluted plasma samples and antibodies are allowed to react for 33 s before the change in turbidity is measured as a Peak maximum at 405 nm. The optimal concentrations of calibrators and antibodies have been determined to secure antibody excess. Response time (i.e. delay between aspiration of a sample and presentation of the result in absorption units) is 75 s. Automatic print-out of the absorbance profile and movement of the sample rack further accounted for 21 s per sample, so the throughput is reduced to 75 determinations per 2 h. Results are available within an hour, compared to two-12 days with the present methods (electroimmunoassays). Parallel analyses with established methods/analysers show excellent agreement for u-albumin, p-transferrin and p-haptoglobin. For p-IgG, p-IgA and p-IgM the reaction time of 33 s is insufficient because their relative molecular masses (i.e. the size of the molecules) are so high, 150.000-971.000. Five minutes is a more adequate reaction time, which makes a serial analyser such as FIA Star unsuitable for larger workloads of samples of immunoglobulins. The plasma concentration of Orosomucoid is low, resulting in high sample blanks. It is therefore recommended that the reaction is followed kinetically if a serial analyser is used

Cartilage Oligomeric Matrix Protein Associates Differentially with Erosions and Synovitis and Has a Different Temporal Course in Cyclic Citrullinated Peptide Antibody (Anti-CCP)-positive versus Anti-CCP-negative Early Rheumatoid Arthritis

Objective.Cyclic citrullinated peptide antibody (anti-CCP)-positive and anti-CCP-negative rheumatoid arthritis (RA) have been suggested as 2 distinctive disease subsets with respect to disease activity and prognosis. Previously, we proposed that anti-CCP antibodies might have a chondrocyte-suppressive effect. We aimed to compare circulating cartilage oligomeric matrix protein (COMP), a marker of cartilage turnover, in untreated anti-CCP-positive and anti-CCP-negative RA, and to study the temporal pattern of COMP through 4 years of treatment, including the relationship to imaging and clinical findings.Methods.A total of 160 patients with newly diagnosed RA who were naive to disease-modifying antirheumatic drugs were included in the CIMESTRA trial. Ninety healthy blood donors served as controls. Demographic and disease measures including Disease Activity Score in 28 joints, IgM rheumatoid factor, anti-CCP, Health Assessment Questionnaire, visual analog scale scores for pain and global and physician assessment, and magnetic resonance imaging (MRI) of the nondominant hand were recorded at baseline. COMP in serum was measured by ELISA at inclusion and serially through 4 years.Results.Median baseline COMP was higher in patients with RA [9.8 U/l (interquartile range 8.96, 10.5)] compared with controls [8.3 U/l (IQR 7.84, 8.9); p &lt; 0.001] and remained elevated at 4 years [10.8 U/l (IQR 10.2, 11.7); p &lt; 0.001]. At baseline, anti-CCP-positive patients had lower COMP than anti-CCP-negative patients (p = 0.048). In anti-CCP-positive patients, COMP exhibited a parabolic course over 4 years, while COMP in anti-CCP-negative patients had an almost linear course. In anti-CCP-positive patients, COMP was associated with MRI edema and erosion score, while COMP was correlated with synovitis score in anti-CCP-negative individuals.Conclusion.Our study provides additional evidence for the existence of different disease pathways in anti-CCP-positive and anti-CCP-negative subsets of RA, and evidence that anti-CCP antibodies may be implicated in the disease process by modifying cartilage metabolism.</jats:sec

Shell we cook it? An experimental approach to the microarchaeological record of shellfish roasting

In this paper, we investigate the microarchaeological traces and archaeological visibility of shellfish cooking activities through a series of experimental procedures with direct roasting using wood-fueled fires and controlled heating in a muffle furnace. An interdisciplinary geoarchacological approach, combining micromorphology, FTIR (in transmission and ATR collection modes), TGA and XRD, was used to establish a baseline on the mineralogical transformation of heated shells from aragonite to calcite and diagnostic sedimentary traces produced by roasting fire features. Our experimental design focused on three main types of roasting procedures: the construction of shallow depressions with heated rocks (pebble cuvette experiments), placing shellfish on top of hot embers and ashes (fire below experiment), and by kindling short-lived fires on top of shellfish (fire above experiments). Our results suggest that similar shellfish roasting procedures will largely create microstratigraphic signatures of anthropogenically reworked combusted material spatially "disconnected" from the actual combustion locus. The construction of shallow earth ovens might entail an increased archaeological visibility, and some diagnostic signatures of in situ hearths can be obtained by fire below roasting activities. We also show that macroscopic visual modifications and mineralogical characterization of discarded shellfish might be indicative of specific cooking activities versus secondary burning.Max Planck Societyinfo:eu-repo/semantics/publishedVersio