Robert L. Peters

Supravalvular Aortic Stenosis Clinical, Hemodynamic and Pathologic Observations

In 3 patients obstruction to left ventricular outflow was shown to be due to a localized narrowing of the aortic root at the point of insertion of the aortic leaflets. The site of obstruction was localized by left heart catheterization and selective angiography. The pathologic findings in 2 patients are described and the problem of the surgical management of this unusual form of aortic stenosis is discussed.

Murine C-type RNA virus from spontaneous neoplasms: in vitro host range and oncogenic potential.

Strain BALB/c mice harbor at least two host range variants of marine leukemia virus. One variant, which is host-cell tropic, is the predominant isolate from neoplastic tissues and produced lymphoreticular neoplasms when injected into BALB/c newborn mice. A second variant, whicht is isolated throughout life, grows poorly in host embryonic cells in culture and was not associated with lymphoreticular neoplasm induction when injected into newborn BALB/c mice.

Cordycepin inhibition of 3-methylcholanthrene-induced transformation in vitro.

Summary Cordycepin (3-deoxyadenosine), an inhibitor of poly (a) synthesis, was found to inhibit the induction of the endogenous type “C” RNA virus by 5-iodo-2′-deoxyuridine in a line of Fischer rat embryo cells (H43) grown in vitro, and when continuously incorporated into the medium at those same concentrations, it was found to protect the cells from transformation by the chemical carcinogen 3-methylcholanthrene. The authors are deeply grateful to Drs. Aaron E. Freeman, Mina Lee Vernon, and Janet Hartley for their advice in the preparation of this manuscript, and to Dr. Bernard Sass for the pathological diagnosis of the tumors.

Inconsistency of cell-mediated immunological assays when viral reagents contain endotoxin.

Summary Endotoxin in concentrations of 5-2500 ng per mg of virus protein, was found in type-C RNA virus reagents. Cell-mediated immune responses induced with these endotoxin-contaminated reagents were evaluated by the lymphocyte transformation assay and the footpad swelling assay. The presence of even subnanogram concentrations of endotoxin altered assay results. Both immunoenhancement and immunosuppression was observed.