ticularly if the utility industry does not itself carry a major share of the load," he comments. No single private utility will be able to bear the cost burden alone. What will be needed, he suggests, is a cooperative program involving some 10 to 15 utility companies combining their efforts and pooling their resources. However, if such a move isn't made soon, the Government may step in. Then the power supply companies could be faced with losing some of the independence they now enjoy, Dr. Johnson warns.
Pollution-Free Source Utility company executives have been asked to consider giving financial backing to a process developed jointly by American Oil Shale Corp. and Battelle Northwest. The process promises to provide a pollution-free source of energy to drive the turbines of electrical generating stations. The plan for the process—called Plowshare—Geothermal—which was outlined by American Oil Shale, Salt Lake City, at a briefing held in Las Vegas, Nev., calls for underground detonation of nuclear devices—most probably fission "bombs"—at depths of 5000 feet or more. Critical parameters governing selection of a site, American Oil Shale's president Rod Dixon says, are the temperature of the rock formation, isolation from population centers, freedom of the formation from fissures that might result in escape of radioactivity or contamination of ground water, and adequate formation size. The closer to the surface such conditions are found, the more economical the process would be, Mr. Dixon adds. Given the proper conditions, the company's plans call for explosion of a series of fission devices to fracture dry, hot rock, creating temperatures of about 350° F. About a quarter of the heat would be supplied by energy of fission and three quarters by the inherent heat of a geothermal rock formation. Water would be piped into the fractured rock where it would be converted to steam. Captured as it flowed to the surface, the superheated steam would be piped to turbines in a conventional generating station. The steam would then be condensed and recycled. The process would be pollution-free because no fossil fuel would be used and no cooling water would be released to the environment. The Atomic Energy Commission, which, along with Battelle and AOS, is participating in a technical feasibility study scheduled for completion in February 1971, stresses that it has substantial experience with under-
ground nuclear explosions and doesn't foresee any difficulties in ensuring complete containment of the radioactivity resulting from fission. As many as 10 western states may provide proper conditions for creation of such energy wells, American Oil Shale's Dixon says. A 5-mile-square area, 5000 feet thick, he notes, offers an estimated energy potential equivalent to half that represented by known huge oil reserves on the Alaskan North Slope. American Oil Shale's project, if successful, might eventually overshadow plans to tap natural geothermal steam formations (C&EN, Aug. 17, page 12), which tend to be small and dispersed. As many as 5000 wells, for example, may have to be drilled to fully exploit naturally occurring geothermal steam in California's Imperial Valley.
THE CHEMICAL WORLD THIS WEEK
toside, a ganglioside comprising ceramide (an N-acylsphingosine) and a trisaccharide. The resulting ganglioside with a tetrasaccharide chain, as well as higher gangliosides produced by adding further saccharide residues to the tetrasaccharide, are present in lower amounts in membranes of cells transformed by polyoma virus or SV40, a virus from monkeys. Results from two other research groups, however, raise the question of
CANCER:
Enzyme Change The discovery of a missing or inactive enzyme in a culture of mouse embryo cells invaded by a tumor-causing virus was disclosed by Dr. Roscoe O. Brady at a symposium on glycosphingolipids sponsored jointly by the Division of Carbohydrate Chemistry and the Division of Agricultural and Food Chemistry at the 160th ACS National Meeting in Chicago. This is the first finding of an enzyme change that is responsible for alteration in surface properties of the cell and that is caused by incorporation of viral DNA into the cell's normal genetic apparatus, Dr. Brady says. Interest in the discovery is heightened because the enzyme, an N-acetylgalactosaminyl transferase, is involved in synthesis of glycolipids in the plasma membrane that forms the outer surface of each cell. Changes in a cell's surface may be responsible for three characteristics of a virus-transformed cell: loss of contact inhibition (the cell continues to grow and divide in spite of contact with surrounding cells), different antigenic properties (the cell is attacked by antibodies of the host animal), and ability of the transformed cell to invade other tissues. Dr. Brady and his coworkers—Dr. Federico A. Cumar, a visiting scientist from University of Cordoba, Argentina, presently in Dr. Brady's laboratory at National Institute of Neurological Diseases and Stroke, Bethesda, Md., and Dr. Peter T. Mora of the National Cancer Institute, Bethesda— sought the enzyme change after finding that certain glycolipids are present in lower amounts in virus-transformed cells than in normal ones (C&EN, Dec. 8, 1969, page 17). The transferase adds N-acetylgalactosamine to hema-
NINDS's Roscoe Brady Finding a missing enzyme
whether the ganglioside changes might occur in normal cells when going from a contact-inhibited state to a growing state, without addition of a virus. Two papers discussing reduced amounts of glycolipides, including radioactive tracer-labeled gangliosides, in growing normal cells were presented at the Chicago symposium by Dr. Senitiroh Hakomori of University of Washington, Seattle, and by Dr. Phillipf W. Robbins of Massachusetts Institute of Technology. The Washington and MIT groupshave used cell lines different from those studied by Dr. Brady's group, which makes an immediate reconciliation of results difficult. There may be further differences—of uncertain significance—in culture media, analytical methods, and susceptibility of various cultures to contact inhibition. With the cell lines studied by the Bethesda group, reduced amounts of both higher gangliosides and the transferase are found only in virus-transformed cells, Dr. Brady says, and not in contactinhibited normal cells, growing normal cells, or cells that have spontaneously— without addition of a virus—transformed to become tumerous. SEPT. 28, 1970 C&EN 13
