JUST A SPOONFUL OF ... ROUND-UP? Gardeners may have more invested in pesky weeds than a bad back. For anybody infected with Toxoplasma or Cryptosporidium, a dose of the herbicide glyphosate (a.k.a. Round-UpTM), or something similar, may be just what the doctor ordered, according to a team of scientists led by Rima McLeod of the University of Chicago (F. Roberts et al., Nature, 393:801-5, June 25,1998). The organisms, which cause serious opportunistic infections in AIDS patients, are apicomplexan protists containing the remnants of chloroplasts perhaps inherited from photosynthetic ancestors. Since plant chloroplasts house the shikimic acid pathway, the starting point for synthesis of essential folic acid and aromatic amino acids, McLeod's team wondered if apicomplexans do the same thing (hints were already in the literature). If so, they may be sensitive to agents such as glyphosate, which block shikimate pathway enzymes. Since humans lack these enzymes, the therapeutic possibilities are obvious. The researchers detected three shikimate enzyme activities in Toxoplasma gondii, including glyphosate's target, EPSP synthase, and a gene for chorismate synthase, the next enzyme in the pathway; their location in the vestigial chloroplast is, however, still uncertain. Not surprisingly, glyphosate and other drugs that target folate synthesis inhibited apicomplexans (including Plasmodium, which causes malaria) in vitro, and synergistically protected infected mice. While glyphosate's future in human health is far from proven, the results open the way for development of new drugs. "There are already other active compounds and other ways such as fluorinated substrates and antisense to target the pathway," according to McLeod. And what does Round-Up's manufacturer, Monsanto Co., think of the work? Spokesperson Lisa Drake says that the company will monitor progress in "an attempt to gain more information."
SERTOLI PATENTS A few body parts escape immune surveillance, such as the eye and the testis. Based on the discovery of how the testis remains "immunoprivileged," Sertoli Technologies Inc. of Tucson, Ariz., is putting these sperm nurse cells to work here--such as with pancreatic islet cells to treat diabetes. In 1993, Helena Selawry, then at the University of Tennessee in Memphis, found that Sertoli cells knit the tight walls of the seminiferious tubules and secrete a smorgasbord of growth factors plus biochemicals that destroy T cells (H. Selawry, D. Cameron, Cell Transplantation, 2:123-9, 1993). "Sertoli cells produce an amazing array of proteins that include growth and immunosuppressive factors," says Shaun Kirkpatrick, vice president at the company. Selawry wondered if Sertoli cells might protect transplanted cells too. So she placed pancreatic islets in the testes of diabetic rats. The islets escaped immune detection, but they did not function, because the temperature in the testis is a few degrees below that of the abdomen. "Dr. Selawry moved a testis implanted with islets from the scrotal position to the abdomen, and the diabetic animal became cured," Kirkpatrick adds. The company, awarded patents on the technology in March and June, has two types of projects planned. In vivo work will team Sertoli cells with cells to treat diabetes, Parkinson's disease, osteoporosis, and other conditions. Plus, the rich broth left behind by the busy cells, called "Sertoli cell-conditioned media," is a powerful boost to cell cultures.
GRANTS, GRANTS, GRANTS The 1998 edition of Oryx Press's Directory of Research Grants catalogs more research grants than the average scholar could ever use. The 1,200-page book features the listings of 6,000 research funding programs that "offer nonrepayable research funding for projects in medicine, the physical and social sciences, the arts and humanities, and education." Also included are the Internet listings of more than 400 sponsoring institutions. The publisher claims to have improved the book with 400 new entries, a better cross-referenced subject index, and an updated Guide to Proposal Planning and Writing written by grants expert Lynn E. Miner. Directories are available at public and university libraries and sponsored research offices. Interested parties can also purchase a copy for $135.00 by contacting Oryx Press at (602) 265-2651 or by accessing the publisher's Web site at www.oryxpress.com. A CD-ROM version of the directory, updated bimonthly, is also available for $1,500 per year with CD-ROM drive, or $850 per year without. This October, Oryx plans to launch a Web version of the directory complete with an E-mail service to notify subscribers of revisions.
NEW PLANT RESEARCH CENTER Are plants the key to alleviating disease and hunger? Five institutions are banking on it. On July 31, the Missouri Botanical Garden, the University of Missouri-Columbia, the Monsanto Co., the University of Illinois at Champaign-Urbana, and Washington University in St. Louis announced the formation of the independent, not-for-profit Donald Danforth Plant Science Center. Slated to open in St. Louis by August of the year 2000, the 190,000-square-foot complex, is being billed as one of the world's largest and most advanced research facilities dedicated to basic plant science; it will include laboratories, greenhouses, a library, and seminar and meeting facilities. Early estimates suggest that the physical structure and labs will cost $45 million, greenhouses and equipment another $15 million. Having received a $146.4 million commitment from Monsanto and the Danforth Foundation of St. Louis, the facility, which will have an initial annual operating budget of approximately $10.5 million, has already raised enough money to stay in business for 15 to 20 years. "Plant sciences is woefully under resourced by the federal government and by philanthropic and other sources," says Sam Fiorello , the assistant to the president of Monsanto. "There's a lot of plant science strength in St. Louis and in the region, but we really would like to see a catalyst ... a new entity with a critical mass in plant sciences." According to Fiorello, the specific initiatives of the Center will be left to the founding director, Roger N. Beachy , the head of the Division of Plant Biology at Scripps Research Institute in La Jolla, Calif., since 1991. Fiorello does, however, emphasize that one of the Center's primary goals will be to implement a technology transfer with researchers from developing countries.
CORRECTION In a Notebook story on the General Motors Cancer Research Foundation awards ( The Scientist, 12:31, July 6, 1998), the name of the winner of the Charles F. Kettering Medal, Rodney Withers, a professor of radiation oncology at the University of California, Los Angeles--was misspelled.