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G Seegan

Publications and source records attributed to G Seegan.

3 recordsLinked to original sources
PubMed1988

A sensitive radioimmunoassay for somatomedin-C/insulin-like growth-factor I based on synthetic insulin-like growth factor 57-70.

We have developed a region-specific radioimmunoassay for somatomedin-C/insulin-like growth factor-I (IGF-I) directed against IGF-I 57-70. This sequence includes part of the A region and all of the carboxyterminal D region. In addition to being highly specific, this immunoassay is sensitive to as little as 1 ng/ml of IGF-I, and has half-maximum displacement by 10 ng/ml of IGF-I. Comparison to other existent immunoassays for IGF-I shows correlation coefficients of greater than 0.95. This immunoassay has the advantage of being directed against a known region of the IGF-I molecule which is on the exterior of the 3-dimensional structure, and can use a readily available synthetic peptide as both radioligand and standard.

Antibody Specificity↗
PubMed1982

Characterization of an insulin-like growth factor-I/somatomedin-C radioimmunoassay specific for the C-peptide region.

Insulin-like growth factor-I (IGF-I) and somatomedin-C )SM-C) have been shown to be functionally identical by a number of criteria. We have synthesized the 12 amino acid C-peptide region of IGF-I (Gly-Tyr-Gly-Ser-Ser-Ser-Arg-Arg-Ala-Pro-Glu-Thr) and developed a RIA based on antibodies against this synthetic peptide. IGF-I and SM-C were indistinguishable in this RIA. No other peptides competed for this antiserum. The SM-C/IGF-I values of acid-chromatographed serum were strongly age dependent. The mean of children 1-5 yr old was 0.67 +/- 0.033 U/ml (mean +/- SD; n = 23), whereas the mean of children 12-17 yr old was 2.01 +/- 0.66 U/ml (n = 39) and the mean of 38 adults 26-85 yr old was 1.05 +/- 0.34. The SM-C/IGF-I values measured by this RIA were also growth hormone dependent. Thus, this region-specific RIA provides a clinically useful assessment of serum SM-C/IGF-I levels.

Acromegaly↗