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G A Harff

Publications and source records attributed to G A Harff.

7 recordsLinked to original sources
PubMed1990

Radial immunodiffusion and immunoelectrophoresis compared for identifying autoantibodies to lactate dehydrogenase in human serum.

Variant electrophoretic patterns of lactate dehydrogenase isoenzymes were studied. By radial immunodiffusion and immunoelectrophoresis, immunoglobulin and light chain class of autoantibodies to lactate dehydrogenase were identified in nine sera: seven of these sera demonstrated IgG (5 lambda, 2 kappa) autoantibodies to lactate dehydrogenase, the other two demonstrated IgA (both kappa) autoantibodies to lactate dehydrogenase, the other two demonstrated IgA (both kappa) autoantibodies to lactate dehydrogenase. We conclude that radial immunodiffusion and immunoelectrophoresis are equally effective for identifying auto-antibodies to lactate dehydrogenase in serum. Radial immunodiffusion, however, is easier to perform than immunoelectrophoresis.

Autoantibodies↗
PubMed1989

Autoantibodies to lactate dehydrogenase in serum identified by use of immobilized protein G and immobilized jacalin, a jackfruit lectin.

In this method for identifying autoantibodies to lactate dehydrogenase (anti-LDs) in serum, we used immobilized Protein G to bind IgG-complexed LD and immobilized jacalin to bind IgA-complexed LD, leaving non-complexed LD in solution. The non-complexed LD and total LD were kinetically measured. We report results as LD bound to immobilized Protein G and LD bound to immobilized jacalin. Using sera demonstrating IgG and IgA anti-LDs by immunoelectrophoresis (IEP), respectively, we optimized the method for incubation time and concentration of binding agents. We demonstrated concomitant binding of LD and greater than or equal to 98% of IgG and of LD and greater than or equal to 92% of IgA. For LD bound to immunobilized Protein G the detection limit was 10 U/L, within- and between-run CVs ranged from 2.9% to 9.1%, and values for normal sera were less than or equal to 3% of total LD. Results for LD bound to immobilized jacalin were similar. We tested 10 sera displaying aberrant LD electrophoretograms: In seven, LD bound to immobilized Protein G was increased (range: 26-99% of total LD), indicating IgG-complexed LD. This was confirmed by IEP, demonstrating IgG1,2, or IgG3 anti-LDs in these sera. In the other three sera, LD bound to immobilized jacalin was increased (range: 38-72% of total LD), indicating IgA-complexed LD. This was confirmed by IEP, demonstrating IgA anti-LDs in these sera. Evidently this method is an alternative to IEP for identifying anti-LDs in serum.

Autoantibodies↗
PubMed1987

Evaluation of the Hitachi 704 automatic analyzer.

We evaluated the analytical performance of the Hitachi 704 automatic analyzer. The spectrophotometer showed a linearity of response at 340 nm up to 2.8 A. Photometric imprecision measured bichromatically at 340 and 376 nm was 0.49% at 0.16 A, 0.14% at 0.46 A, and 0.17% at 0.76 A. Imprecision of the sample probe was 0.4% for 5, 10, and 20 microL, and the volume delivered deviated -2.4%, -4.4%, and -4.2% from these preset volumes, respectively. Imprecision of the reagent probe over the range 50 to 500 microL ranged from 0.14% to 0.29%; volume delivered deviated from +1.7% to +4.4%). At equilibrium, the temperature in the cuvets was 29.8 (SD 0.05) degree C as measured by cresol red spectrophotometry. No sample carryover was detected. Reagent carryover was detected when a bilirubin assay was preceded by a total protein assay and when lactate dehydrogenase was measured after alanine aminotransferase. Imprecision for nine tests at three concentrations ranged from 1.1% to 4.4%. Comparison of methods with the SMAC II as reference method showed good results. Precision was better than reported for the Hitachi 705 automatic analyzer.

Autoanalysis↗
PubMed1985

Rate-nephelometric determination of fibronectin in plasma.

We describe a kinetic immunonephelometric method for the determination of fibronectin in human plasma, used with the Beckman ICS rate nephelometer. The method is rapid and cost-effective. Two commercially available controls stated by the manufacturer to contain 200 and 295 mg/L were found to contain 198 and 290 mg/L, respectively. Mean analytical recovery was 104%. Within-run precision (CV) for normal samples was 3.8%, between-day precision 5.1%. For samples containing subnormal concentrations of fibronectin, these figures were 3.8% and 6.7%, respectively. Results by the method described here agreed and correlated well with those by a commercially available turbidimetric assay. With appropriately diluted samples, the range of measurement is 40 to 1000 mg/L. Normal values for women and men were 286 (SD 84) and 340 (SD 55) mg/L, respectively, in good agreement with values published by others.

Animals↗