No abstract

Betacellulin, a member of the epidermal growth factor family, has been identified in the conditioned medium of cell lines derived from mouse pancreatic beta cell tumors. Betacellulin is a 32-kilodalton glycoprotein that appears to be processed from a larger transmembrane precursor by proteolytic cleavage. The carboxyl-terminal domain of betacellulin has 50 percent sequence similarity with that of rat transforming growth factor alpha. Betacellulin is a potent mitogen for retinal pigment epithelial cells and vascular smooth muscle cells.

An Epstein-Barr virus (EBV)-producer line, designated Akata, was established from a Japanese patient with Burkitt's lymphoma. The Akata line possessed the Burkitt's-type chromosome translocation, t(8q- ; 14q+), and was derived from the tumor cell. Akata cells produced a large quantity of transforming virus upon treatment of cells with anti-immunoglobulin antibodies (Takada, 1984). Southern blot analysis of viral DNA indicated that the Akata EBV is nondefective and more representative of wild-type viruses. Akata cells should be useful as a source of EBV.

Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. Ion acceleration and direct ion heating in three-component magnetic reconnection