Human brain tumor-associated urinary high molecular weight transforming growth factor: a high molecular weight form of epidermal growth factor.

Urinary protein obtained from a patient with a highly malignant brain tumor (astrocytoma, grade IV) was adsorbed to trimethylsilyl controlled-pore glass beads and selectively eluted with acetonitrile to yield a high molecular weight (HMW) human transforming growth factor (hTGF). This HMW hTGF promoted clonogenic cell growth in soft agar and competed for membrane receptors with mouse epidermal growth factor. After surgical resection of the tumor, no HMW hTGF was found in urine.

Rapid radioimmunoassay for corticotropin in unextracted human plasma.

This RIA for corticotropin (ACTH) involves use of a commercially available antiserum and permits measurement of immunoreactive ACTH in unextracted plasma. The assay takes 2.5 days, detects as little as 5 pg/mL of plasma, and is specific: structurally and (or) biosynthetically related peptides do not cross react.

Epidermal growth factor in human milk: daily production and diurnal variation during early lactation in mothers delivering at term and at premature gestation.

Epidermal growth factor is a polypeptide that stimulates proliferation and differentiation of a variety of cell types, including the developing intestinal epithelium; it is the agent in human milk that induces mitosis in human fibroblast culture. We systematically evaluated the EGF content of milk from 20 women delivering prematurely and from 11 women delivering at term. In preterm mothers, the concentration of EGF was 70 +/- 5 ng/ml (mean +/- SEM), with no significant change during seven weeks of lactation.

Proopiolipomelanocortin peptides in normal pituitary, pituitary tumor, and plasma of normal and Cushing's horses.

Using RIAs for six regions within proopiolipomelanocortin (proOLMC), gel filtration, and electrophoresis, we studied pituitary peptides in a normal horse and one with Cushing's disease caused by a pars intermedia adenoma. Almost all immunoreactive (IR) ACTH (78%) was 4,500 mol wt (4.5K) ACTH in normal pars distalis, but it was almost 100% corticotropin-like intermediate lobe peptide (CLIP) in normal pars intermedia.

Human placental immunoreactive corticotropin, lipotropin, and beta-endorphin: evidence for a common precursor.

The concentrations and molecular sizes of immunoreactive corticotropin (ACTH), lipotropin (LPH, beta LPH plus gamma LPH), gamma LPH, and beta-endorphin (beta END) were determined in human placental extracts. Serial dilutions of a water extract of placenta generated competitive binding curves parallel with that of the standard in each assay. The concentrations of ACTH, LPH, gamma LPH, and beta END were 3.