Distribution of cells expressing myc proteins in human colorectal epithelium, polyps, and malignant tumors.

The myc gene family encodes nuclear phosphoproteins that are thought to play a role in the control of cellular proliferation and differentiation. We have undertaken an immunohistochemical study assessing the expression of myc gene family proteins in individual cells of normal colonic mucosa, colorectal polyps, and colorectal adenocarcinomas. We screened a panel of mouse monoclonal antibodies that we raised against recombinant human c-myc and N-myc proteins for recognition of myc proteins in paraffin tissue sections.

Elevated plasma platelet-derived growth factor B-chain levels in cancer patients.

Platelet-derived growth factor (PDGF) is produced by a variety of normal and tumor cells in vitro. We have developed an enzyme-linked immunosorbent assay for the detection of the B-chain of PDGF. This assay can reliably detect 0.

Monoclonal antibodies to hepatitis A virus.

This paper describes the development of monoclonal antibodies generated against hepatitis A virus (HAV). Monoclonal antibodies (MCABs) from two murine hybridoma cell lines were found to bind to an epitope recognized in the sera of patients recovering from infection with HAV. Ascites fluids containing MCABs from one hybridoma (H1 C19) inhibited a maximum of 70% of the 125I-labeled polyclonal human anti-HAV from binding to HAV-antigen in a competitive radioimmunoassay, indicating that the MCAB recognizes a major epitope of HAV.

Starch-synthesizing Enzymes in the Endosperm and Pollen of Maize.

Two mutations, amylose-extender and waxy, which affect the proportion of amylose and amylopectin of starch synthesized in the endosperm of maize (Zea mays L.) seeds, are also expressed in the pollen. However, most mutations that affect starch synthesis in the maize endosperm are not expressed in the pollen.

Effects of dextran on the molecular structure and tensile behaviour of human fibrin.

Characteristic changes induced by dextran during the conversion of fibrinogen to fibrin have previously been shown to be associated with profound alterations in morphology of fibrin. However, whether dextran is incorporated into the fibrin molecule and whether morphological changes are associated with alterations in mechanical behaviour of formed fibrin was unclear. The investigations described show that the fibrin made in the presence of dextran has a shortened syneresis time, a lowered modulus of elasticity, an increased elongation and diminished ultimate strength at break.