Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.2.1.1 (ACS)
 78,556 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case is presented of a patient with stage D prostatic carcinoma, from whom a serum sample proved to be an outlier in a correlation study performed with a 2nd-generation prostate-specific antigen (PSA) assay on the Immulite system (6.4 micrograms/L) and IMx (101 micrograms/L). Clearly, the PSA result reported by Immulite was falsely low. For nine longitudinal samples, Immulite results were approximately 20-fold lower than the IMx value (range of IMx results 5-275 micrograms/L). A selection of the samples was analyzed with the ACS:180, ES-600, and IMx (all > 180 micrograms/L); Immulite, DPC Coat-A-Count IRMA, Immuno 1, AIA-pack, and Tandem-R (all <70 micrograms/L); and Immulite free PSA assay (41 micrograms/L). Gel filtration demonstrated that apart from the alpha1-antichymotrypsin (ACT) complex, no other complexes were found. However, the sample consisted of 53% free PSA (IMx). Possibly, a change of conformation of the PSA molecule resulted in a decreased binding to ACT and a reduced affinity of the antibodies used in the affected assays.
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PMID:Large discrepancy between prostate-specific antigen results from different assays during longitudinal follow-up of a prostate cancer patient. 890 99

Sensitive TSH immunoassays offer a clear advance in discriminating the TSH concentrations in serum between hyperthyroid and euthyroid individuals; they have been proposed as the best single screening test for thyroid disorders. We have developed a highly sensitive serum TSH TRFIA based on DELFIA technology. Three monoclonal antibodies (McAbs) directed against different epitopes of the TSH molecule were involved in this assay, of which, one McAb was used to coat clear microwells, and the other two were biotinylated' for signal generation after being bound by the europium labeled streptavidin. The europium label captured on the well surface was quantified by a routine dissociation-enhancement procedure. The fluorescence intensity was directly proportional to the serum hTSH concentration. The assay required two steps and could be completed within 5 h. The analytical sensitivity reached 0.002 mIU/L with a sample volume of 100 microL, the function sensitivity was 0.017 mIU/L. Measurements by the present method correlated well with that obtained by the ACS-180 chemi-luminescence immunoassay (CLIA). The discrimination of hyperthyroid patients from clinically euthyroid patients by the present method was much better than that by the routine IRMA.
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PMID:Time-resolved immunofluorometry of serum hTSH with enhanced sensitivity. 1203 43