Stanley L. Twomey

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We describe a reliable and convenient double-antibody radioimmunoassay for human thyroglobulin that can be performed within two days. Analytical recoveries were quantitative and immunological equivalence between several sources of human thyroglobulin was demonstrated. Cross reactivity with either thyroxine or triiodothyronine was insignificant. The(More)
Comparison of two methods for determining a substance is a common procedure in clinical chemistry. Almost without exception, normal theory statistics are used with the tacit assumption that the data under test show gaussian distributions. Experience has led us to question this assumption for populations of differences between values obtained by two methods(More)
Previously published methods for purifying alpha1-fetoprotein are inadequate because they either do not yield a completely pure product or they cause some denaturation. We present a method that does not have these serious disadvantages, and with which alpha1-fetoprotein was purified by sequential use of concanvalin A affinity-chromatography, preparative(More)
Cells containing gonadotropin-releasing hormone (GnRH) are essential not only for reproduction but also for neuromodulatory functions in the adult animal. A variety of studies have hinted at multiple origins for GnRH-containing cells in the developing embryo. We have shown, using zebrafish as a model system, that GnRH cells originate from precursors lying(More)
The test described here was designed as a screening test to be used in conjunction with the radioimmunoassay for human thyroglobulin. Anti-thyroglobulin autoantibodies, when present even in low concentrations, interfere with thyroglobulin determination. A 30-min incubation allows binding of 125I-thyroglobulin to endogenous anti-thyroglobulin autoantibodies.(More)
We report our evaluation of a commercially available procedure and reagents for determination of ferritin in serum by enzyme-labeled immunosorbent assay (ELISA). Results by our procedure and the "Fer Iron" (Ramco Labs) procedure shows a degree of association (r) of 0.95 and a regression equation of y = 1.03x - 33. Similarly, our procedure compared to the(More)
1. A rapid radioimmunoassay (RIA) for determining serum triiodothyronine (T3) concentration has been developed. The reaction of T3 with its antibody was performed at 37 degrees C for 3 hours; precipitation of antibody bound T3 by 15% polyethylene glycol (PEG) was done at ice-bath temperatures. 2. The effects of pH on the interaction of T3 with its antibody(More)
Previously published methods for purifying a1-fetoprotein are inadequate because they either do not yield a completely pure product or they cause some denaturation. We present a method that does not have these serious disadvantages, and with which a1-fetoprotein was purified by sequential use of concanavalin A affinity-chromatography, preparative(More)