been since July 1974. The firm believes that demand for engineers and scientists will strengthen still more in the first quarter of this year. In addition, C&EN's employment index for chemists and chemical engineers (based oh the volume of classified job advertising in each issue) stands at the highest point in four years.
Salaries generally are up too, but not by much. In the scientific disciplines, for example, average salaries gained 2 to 5% from last year. The highest average salary offer that the council survey found was for petroleum engineers with bachelor's degrees: $1508 per month ($18,000 per year). D
Unusual DNA recombina tion in nature While the merits of continuing recombinant DNA research are being debated (see page 23), suggestions that nature dabbles with its own recombinant technology are emerging. For instance, a certain bacterium, Pseudomonas maltophilia, not only has a receptor for a mammalian hormone, but also secretes a molecule that behaves like that hormone. "This may be an example of natural recombinant DNA," Dr. Robert J. Ryan of the department of molecular medicine at Mayo Medical School, Rochester, Minn., said at a National Institutes of Health endocrinology conference last week. If recombinant events take place naturally, some worries over scientists' proceeding with recombinant DNA research might be quelled. But, adds Ryan, who is collaborating with Dr. Nancy D. Richert, although the bacteria-hormone story has a beginning, "I haven't got the slightest idea what the end of it will be." Certainly, those findings present some puzzles. For instance, the bacterial receptor binds the hormone human chorionic gonadotropin (HCG) tightly and specifically. Also, the bacteria secretes a molecule resembling HCG. But HCG has no detectable effect on the pseudomonad, Ryan says. It's difficult to imagine why it should. One of four human glycoprotein hormones, HCG is important during the early stages of pregnancy. Produced by the placenta, it helps maintain part of the ovary called the corpeus luteum that produces progesterone until the placenta takes over. Thus HCG is a molecule with highly specific functions—and hence seems rather out of place in a bacterium. However, says Ryan, neither the HCG-like molecule nor its receptor is found in many bacteria. Besides the pseudomonad mentioned. Ryan and Richert find the receptor in Brucella suis, a species that causes infectious abortions in swine. There, Ryan speculates, the bacteria's binding of HCG might be responsible for abortions. Other scientists have found HCG-like molecules in bacteria. For example, a strain called Progenitor 8
C&EN March 21, 1977
I cryptocoides, which was isolated from cancer patients, reportedly secretes an HCG-like molecule, though Ryan cannot repeat those results. However, Dr. Herman Cohen and Dr. Alice Strampp at Princeton Laboratory Products Co. in New Jersey also have found a bacterium that produces a HCG-like molecule. Finding a purpose for the HCG-like molecule and its receptor in bacteria is a long-range problem. Right now, attention focuses on whether the bacteria acquired mammalian genes to make these molecules. For several reasons, Ryan is skeptical that natural genetic recombination is involved. For example, HCG, which is a glycoprotein of about 40,000 molecular weight, contains two subunits that are not covalently linked. Possibly the two are made by separate genes, Ryan says, meaning that several recombinant events would have been needed. Ryan and Richert plan to answer such questions by hybridization studies, comparing mammalian RNA for HCG to bacterial DNA. For now, however, Ryan is cautious, saying that his "gut reaction" is that natural recombination won't explain these findings. D
Molten charge chrome is tapped from furnace at Carbide's Steelpoort plant
Sen. Harry F. Byrd Jr. (I.-Va.), rescinding the ban, based on the argument that the U.S. vitally needed the high-grade Rhodesian chrome for industrial and defense uses. At the time, industry vigorously supported the Byrd amendment. However, its repeal has produced no alarm among chrome users. Two chemical companies potentially affected by the renewed boycott are Airco and Union Carbide, which are big producers of the leading chrome ore product, ferrochrome, used in making stainless steel. At Union Carbide, a spokesman says that the company is concerned at losing an important source of highchromium-content ore. However, he adds that there will be little practical disruption from Congress' move. Perhaps 80 to 90% of users of high-chromium-content materials probably can switch to low-chromium alloy. This alloy is made with chemical- or lower-grade chromium ore in plants such as Carbide's new 120,000 ferrochrome plant in Congress bars imports ton-per-year Steelpoort, South Africa, which is near most of the world's known reof Rhodesian chrome serves of chemical-grade ore. One Congress has decided to restore U.S. reason for this conversion capability participation in the 1969 United Na- to lower-chromium alloys is stainless tions embargo on chromium imports steel makers' widespread adoption of from Rhodesia. President Carter, who Carbide's own argon oxygen decarrequested the legislation, is expected burization process, which takes excess to sign it in short order. Specifically, carbon out of stainless steel made the bill prohibits importation into the with low-chromium ferrochrome. Other reasons for chrome users' U.S. of steel mill products containing Rhodesian chromium in any form, calm include a big inventory (about and it establishes an enforcement 17 months' worth) of chrome ore and mechanism which requires a certifi- ferroalloys at private companies and cate of origin for such products. the U.S. government. Further, a However, the President would be massive switch in chrome ore sources permitted to reopen trade with Rho- and processing locations in the past desia if he thought it would encourage 20 years has greatly reduced U.S. meaningful negotiations toward ma- dependence on Rhodesian supply. In 1976, Rhodesia supplied just 3% of jority rule. The U.S. participated in the UN U.S. chrome ore imports and 22% of boycott until 1971 when Congress imported ferrochromium alloys, acpassed an amendment, sponsored by cording to the State Department. D
