| 41. |
- Holten-Andersen, MN, et al.
(författare)
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Measurement of the noncomplexed free fraction of tissue inhibitor of metalloproteinases I in plasma by immunoassay
- 2002
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Ingår i: Clinical Chemistry. - 0009-9147. ; 48:8, s. 1305-1313
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Tidskriftsartikel (refereegranskat)abstract
- Background: We previously found differences in total concentrations of tissue inhibitor of metalloproteinases 1 (TIMP-1) in plasma from donors and cancer patients. Because TIMP-1 can exist in more than one molecular form, a new immunoassay to specifically detect free TIMP-1 was developed and concentrations were determined in plasma from healthy donors and colorectal cancer (CRC) patients. Methods: We established and validated an immunoassay for the specific measurement of free TIMP-1 that uses a polyclonal anti-TIMP-1 antibody for capture and a monoclonal anti-TIMP-1 antibody that binds only free TIMP-1 for detection of antigen. Plasma samples from healthy donors and CRC patients were assayed for free TIMP-1. Total TIMP-1 was measured by our previously published assay. Results: The mean (SD) concentrations of free TIMP-1 were similar in citrate [55.5 (11.5) mug/L] and EDTA plasma [58.9 (13.3) mug/L] from 76 donors (r(2) = 0.82). In 154 donors, the ratio of free TIMP-1 [mean (SD), 64.5 (18.0) mug/L] to total TIMP-1 [83.8 (19.8) mug/L] in EDTA plasma was 0.77. Plasma concentrations of free and total TIMP-1 correlated significantly to age (free, r(2) = 0.19; total, r(2) = .0.27; P < 0.0001), increasing 50% over an age span of 45 years. Free and total TIMP-1 were significantly increased in CRC patients (P < 0.0001), whereas the ratio of free to total TIMP-1 (mean, 0.58) was significantly lower than in donors. Conclusions: Most of the TIMP-1 in donor plasma is present in its free form, and free TIMP-1 increases with age. Free and total TIMP-1 are increased in CRC patient plasma, but the ratio of free to total TIMP-1 is significantly lower in these patients than in donors. (C) 2002 American Association for Clinical Chemistry.
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| 42. |
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| 44. |
- Jonsson, Magnus, et al.
(författare)
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Computer-supported detection of M-components and evaluation of immunoglobulins after capillary electrophoresis
- 2001
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Ingår i: Clinical Chemistry. - 0009-9147. ; 47:1, s. 110-117
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Electrophoresis of serum samples allows detection of monoclonal gammopathies indicative of multiple myeloma, Waldenstrom macroglobulinemia, monoclonal gammopathy of undetermined significance, and amyloidosis. Present methods of high-resolution agarose gel electrophoresis (HRAGE) and immunofixation electrophoresis (IFE) are manual and labor-intensive. Capillary zone electrophoresis (CZE) allows rapid automated protein separation and produces digital absorbance data, appropriate as input for a computerized decision support system. METHODS: Using the Beckman Paragon CZE 2000 instrument, we analyzed 711 routine clinical samples, including 95 monoclonal components (MCs) and 9 cases of Bence Jones myeloma, in both the CZE and HRAGE systems. Mathematical algorithms developed for the detection of monoclonal immunoglobulins (MCs) in the gamma- and ss-regions of the electropherogram were tested on the entire material. Additional algorithms evaluating oligoclonality and polyclonal concentrations of immunoglobulins were also tested. RESULTS: CZE electropherograms corresponded well with HRAGE. Only one IgG MC of 1 g/L, visible on HRAGE, was not visible after CZE. Algorithms detected 94 of 95 MCs (98.9%) and 100% of those visible after CZE. Of 607 samples lacking an MC on HRAGE, only 3 were identified by the algorithms (specificity, 99%). Algorithms evaluating total gammaglobulinemia and oligoclonality also identified several cases of Bence Jones myeloma. CONCLUSIONS: The use of capillary electrophoresis provides a modern, rapid, and cost-effective method of analyzing serum proteins. The additional option of computerized decision support, which provides rapid and standardized interpretations, should increase the clinical availability and usefulness of protein analyses in the future.
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| 45. |
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| 46. |
- Kakonen, S M, et al.
(författare)
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Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum
- 2000
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Ingår i: Clinical Chemistry. - 0009-9147. ; 46:3, s. 332-337
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Circulating human osteocalcin (hOC) has been used as a marker of bone formation. Our aim was to validate three immunofluorometric assays (IFMAs), measuring different forms of hOC. METHODS: The two-site IFMAs were based on previously characterized monoclonal antibodies. Assay 2 recognized intact hOC, assays 4 and 9 measured the NH(2)-terminal mid-fragment and the intact hOC. In addition, assay 9 required hOC to be gamma-carboxylated. RESULTS: A 76-79% increase of serum immunoreactive hOC was found in the postmenopausal group compared with the premenopausal group with all IFMAs. With EDTA-plasma samples, the observed increases were lower (49-65%). The hOC concentration in the postmenopausal group receiving hormone replacement therapy was 42-44% lower than that in the postmenopausal control group in both serum and EDTA-plasma samples. The depressed carboxylation in warfarin-treated patients was accompanied by lower results in assay 9. The ratio of assay 9 to assay 4 totally discriminated the warfarin-treated patients from the controls. Assay 9 showed the smallest decreases in measured hOC after storage of serum or plasma for 4 weeks at 4 degrees C, followed by assay 4 and assay 2. Results from the last assay were <17% of their initial values after 4 weeks of storage. No diurnal variation was observed with assay 9 as opposed to the two other IFMAs. CONCLUSION: The three assays with their distinct specificity profiles (intact vs fragmented and carboxylated vs decarboxylated hOC) may provide valuable tools for investigating the significance of different hOC forms in various bone-related diseases.
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