June 21, 1997

Microbial Trigger for Autoimmunity?

The body's initial immune response to an infection, an outpouring of the compound interleukin-12, may trigger autoimmune disease by activating immune cells that recognize the body's own molecules.

References:

Segal, B., et al. 1997. Microbial products induce autoimmune disease by an IL-12 dependent pathway. Journal of Immunology 158(June 1):5087.

Ringing up a microscopic light switch

Researchers have fabricated a tiny optical device called a resonator, which can channel photons from one path to another.

References:

Rafizadeh, D., et al. In press. Waveguide-coupled AlGaAs/GaAs microcavity ring and disk resonators with high finesse and 21.6-nm free spectral range. Optics Letters.

Further Readings:

Chu, D.Y., and S.-T. Ho. 1993. Spontaneous emission from excitons in cylindrical dielectric waveguides and the spontaneous-emission factor of microgravity ring lasers. Journal of the Optical Society of America B 10(February):381.

Jewell, J.L., J.P. Harbison, and A. Scherer. 1991. Microlasers. Scientific American (November):86.

Peterson, I. 1995. Lasing in a photonic wire. Science News 147(June 10):367.

Zhang, J.P., et al. 1995. Photonic-wire laser. Physical Review Letters 75(Oct. 2):2678.

Molecular ball bearings lube metal parts

Microscopic spheres of tungsten disulfide show promise as a solid lubricant for machine parts.

References:

Rapoport, L., et al. 1997. Hollow nanoparticles of WS2 as potential solid-state lubricants. Nature 387(June 19):791.

Further Readings:

1996. Buckyball additives improve lubrication. Science News 150(Aug. 31):139.

Pennisi, E. 1992. Fullerene-like molecules without carbon. Science News 142(Dec. 5):389.

Lowly status proves infectious in monkeys

Macaque monkeys at the bottom of the social pecking order are especially susceptible to a coldlike viral infection.

References:

Coe, C. 1997. Sociality and immunological health revisited. Psychosomatic Medicine 59(May/June):222.

Cohen, S., et al. 1997. Chronic social stress, social status, and susceptibility to upper respiratory infections in nonhuman primates. Psychosomatic Medicine 59(May/June):213.

Further Readings:

Bower, B. 1992. Social ties boost immune function. Science News 142(Oct. 10):237.

______. 1991. Emotional stress linked to common cold. Science News 140(Aug. 31):132.

On a roll: Robot attempts desert voyage

A semi-autonomous rover embarks on a 200-kilometer trip across Chile's Atacama Desert.

References:

Information on the Nomad robot is available at the following addresses: http://img.arc.nasa.gov/Nomad/nomad.html and http://www.ri.cmu.edu/atacama-trek/.

Further Readings:

Monastersky, R. 1992. The inferno revisted. Science News 141(June 6):376.

Young, P. 1993. Kinked cable crimps Dante's Erebus debut. Science News 143(Jan. 9):22.

Hubble images capture colliding supernovas

Astronomers have for the first time detected supernova remnants that are colliding.

References:

Blair, W.P., R.A. Fesen, and E.M. Schlegel. 1997. Meeting of the American Astronomical Society. Winston-Salem, N.C.

Further Readings:

Cowen, R. 1992. Honeycomb structure found in galaxy nearest us. Science News 142(Nov. 21):342.

Skin cancer makes unexpected reappearance

Melanoma sometimes lies dormant in a person for decades before reemerging.

References:

Rigel, D. 1997. Malignant melanoma: Incidence issues and their effect on diagnosis and treatment in the 1990s. Mayo Clinic Proceedings 72(April):367.

Swerlick, R., and S. Chen. 1997. The melanoma epidemic: More apparent than real? Mayo Clinic Proceedings 72(June):559.

Tsao, H., A. Cosimi, and A. Sober. 1997. Ultra late recurrence (15 years or longer) of cutaneous melanoma. Cancer 79(June 15):2361.

Further Readings:

Crowley, N., and H. Seigler. 1990. Late recurrence of malignant melanoma: Analysis of 168 patients. Annals of Surgery 212(August):173.

Fackelman, K. 1992. Skin cancer's return: How big a threat? Science News 141(June 27):421.

Harrington, F. 1993. Study finds new risk factors for melanoma. Cancer News 47(Summer):4.

Rivers, J. 1996. Melanoma. Lancet 347(March 23):803.

Weighing hormone therapy's benefits

Estrogen replacement therapy has been linked to a reduced risk of Alzheimer's disease, and a large study suggests that it reduces deaths from heart disease.

References:

Davidson, M.H., et al. 1997. A comparison of estrogen replacement, pravastatin, and combined treatment for the management of hypercholesterolemia in postmenopausal women. Archives of Internal Medicine 157(June 9):1186.

Grodstein, F., et al. 1997. Postmenopausal hormone therapy and mortality. New England Journal of Medicine 336(June 19):1769.

Kawas, C., et al. 1997. A prospective study of estrogen replacement therapy and the risk of developing Alzheimer's disease: The Baltimore longitudinal study of aging. Neurology 48(June):1517.

Further Readings:

Brinton, L.A., and C. Schairer. 1997. Postmenopausal hormone-replacement therapy -- Time for a reappraisal? New England Journal of Medicine 336(June 19):1821.

Fackelmann, K. 1995. Forever smart. Science News 147(Feb. 4):74.

______. 1995. Alzheimer's link to estrogen. Science News 147(Feb. 4):75.

______. 1993. Heart findings support hormonal therapy. Science News (Apr. 17):246.

Raloff, J. 1997. Alzheimer's: E-longating survival and function. Science News Online (April 26).

______. 1997. Hormone therapy: Issues of the heart. Science News 151(March 8):140.

______. 1996. Boning up on postmenopausal hormones. Science News 150(Nov. 9):293.

______. 1996. Vanishing flesh. Science News 150(Aug. 10):90.

Seachrist, L. What risk hormones? Science News 148(Aug. 5):94.

Sternberg, S. 1996. Estrogen cuts risk of Alzheimer's. Science News 150(Sept. 7):154.

Research Notes:

Biology

Brewing up a double genome

Brewers yeast may once have had more than double the number of genes it has today.

References:

Wolfe, K., and D. Shield. 1997. Molecular evidence for the ancient duplication of the entire yeast genome. Nature 387(June 12):387.

Protein of cancer enzyme identified

Researchers have finally identified a protein component of the enzyme telomerase essential to its activity in tumors.

References:

Lingner, J., et al. 1997. Reverse transcriptase motifs in the catalytic subunit of telomerase. Science 276(April 23):561.

Further Readings:

Travis, J. 1995. End games. Science News. 148(Nov. 25):362.

How much human DNA can mice hold?

Researchers have created mice whose genome contains functioning fragments of human chormosomes, some containing about 1,000 genes.

References:

Tomizuka, K., et al. 1997. Functional expression and germline transmission of a human chromosome fragment in chimeric mice. Nature Genetics 16(June):133.

Further Readings:

Rastan, S. 1997. Of mice and men. Nature Genetics 16(June):113.

Biomedicine

Cow protein may help eye inflammation

A purified protein derived from cow eyes may enable those suffering from uveitis to reduce their dependence on steroids.

References:

Nussenblatt, R.B., et al. 1997. Treatment of uveitis by oral administration of retinal antigens: Results of a Phase I/II ramdomized masked trial. American Journal of Ophthalmology (May). Available at http://www.ajo.com/.

Corneal dystrophy genes mapped

Genetic mutations in either of two genes are responsible for an eye disease known as Meesmann's corneal dystrophy.

References:

McLean, W.H.I., et al. 1997. Mutations in cornea-specific keratin K3 or K12 genes cause Meesmann's corneal dystrophy. Nature Genetics 16(June):184.

Environment

Need 'greener' solvents? Go to PARIS

A new software package could shave months to years off the time it takes to identify environmentally benign solvents.

References:

1997. PARIS -- finding solvent alternatives. Hypotenuse 35(May/June):10.

Zhao, R., et al. 1997. A computer program for assisting the design and replacement of environmentally objectionable solvents. Annual spring conference of the Pollution Prevention Round Table. Denver, Colo.

Further Readings:

1994. Spray fabric dye linked to pneumonia. Science News 146(Sept. 10):175.

Lipkin, R. 1996. Carbon dioxide can help dissolve proteins. Science News 149(Feb. 3):71.

Raloff, J. 1996. Bug sprays may bug you, too -- for a day. Science News 150(Aug. 3):69.

______. 1995. Pesticides' noxious companions. Science News 147(March 18):175.

Superfund sites and birth defects

The federal program is slow to evaluate and clean up hazardous waste sites, while new data links birth defects to living within a quarter mile of a site.

References:

Croen, L.A., et al. 1997. Maternal residential proximity to hazardous waste sites and risk for selected congenital malformations. Epidemiology 8(July):347.

Tice, R.J., et al. 1997. Superfund: Times to complete the assessment and cleanup of hazardous waste sites. U S. General Accounting Office Report RCED-97-20 (March 30).

Further Readings:

Committee on Transportation and Infrastructure, U.S. House of Representatives. 1996. 'Reinventing' Superfund: An assessment of the Clinton adminstration's Superfund reform efforts.

Congressional Budget Office. 1994. The total costs of cleaning up nonfederal Superfund sites. Study Report No. ISBN 0-16-043071-2.

DeLong, J.V. 1995. Privatizing Superfund: How to clean up hazardous waste. Cato Institute Policy Analysis Report No. 247. Washington, D.C.

Wisnoski, E., et al. 1997. Superfund: Stronger EPA-state relationship can improve cleanups and reduce costs. U S. General Accounting Office Report RCED-97-77.

Physics

Diffusing to forget

In a demonstration of short-term memory, a mathematical model representing a type of diffusion shows an ability to remember, then forget a sequence of impulses.

References:

Coppersmith, S.N., et al. 1997. Self-organized short-term memories. Physical Review Letters 78(May 26):3983.

Plasma sparks from a hot gas bubble

Computer simulations of a partially ionized plasma in a collapsing gas bubble reveal that accelerated electrons produce the brilliant flash characteristic of an effect called sonoluminscence.

References:

Crumm, L.A., and T.J. Matula. 1997. Shocking revelations. Science 276(May 30):1348.

Moss, W.C., D.B. Clarke, and D.A. Young. 1997. Calculated pulse widths and spectra of a single sonoluminescing bubble. Science 276(May 30):1398.

Further Readings:

Kaiser, J. 1995. Inferno in a bubble. Science News 147(April 29):266.

Peterson, I. 1996. Glimpses inside a tiny, flashing bubble. Science News 150(Oct. 5):214.

Articles:

Shaping Synthetic Metals

Dendrimers branch out into the electronic world

Polymer molecules with branches emanating from a central core can be fabricated into magnets, light-emitting diodes, liquid crystals, lasers, and antennas.

References:

Kopelman, R., et al. 1997. Spectroscopic evidence for excitonic localization in fractal antenna supermolecules. Physical Review Letters 78(Feb. 17):1239.

Miller, L.M., et al. 1997. Electrically conducting dendrimers. Journal of the American Chemical Society 119(Feb. 5):1005.

Further Readings:

1996. Treelike molecules branch out. Science News 149(Jan. 13):31.

Dagani, R. 1996. Chemists explore potential of dendritic macromolecules as functional materials. Chemical and Engineering News 74(June 3):30.

Pennisi, E. 1991. Buckyballs still charm. Science News 140(Aug. 24):120.

Peterson, I. 1993. From surface scum to fractal swirls. Science News 143(Jan. 23):53.

_____. 1992. Quantum dot to dot. Science News 141(April 4):222.

Tomalia, D.A. 1995. Dendrimer molecules. Scientific American (May):62.

Guardians of the Genome?

Two breast cancer genes may safeguard DNA

Researchers now suspect that the BRCA1 and BRCA2 genes play a role in a cell's ability to detect or repair damaged DNA .

References:

Hakeem, R., et al. 1996. The tumor suppressor gene BRCA1 is required for embryonic cellular proliferation in the mouse. Cell 85(June 28):1009.

Ludwig, T., et al. 1997. Targeted mutations of breast cancer susceptibility gene homologs in mice: Lethal phenotypes of BRCA1, BRCA2, BRCA1/BRCA2, BRCA1/p53, BRCA2/p53 nullizygous embryos. Genes and Development 11:1253.

Rajan, J., et al. 1997. Developmental expression of BRCA2 colocalizes and is associated with proliferation and differentiation in multiple tissues. Developmental Biology 184:385.

Scully, R., et al. 1997. Association of BRCA1 with Rad51 in mitotic and meiotic cells. Cell 88(Jan. 24):265.

Sharan, S., et al. 1997. Embryonic lethality and radiation hypersensitivity mediated by RAD51 in mice lacking BRCA2. Nature 386(April 24):804.

Suzuki, A., et al. 1997. BRCA2 is required for embryonic cellular proliferation in the mouse. Genes and Development 11:1242.

Further Readings:

Kinzler, K., and B. Vogelstein. 1997. Gatekeepers and caretakers. Nature 386(April 24):781.

Travis, J. 1996. Breasts may secrete tumor suppressor. Science News. 149(March 2):132.

______. 1995. Breast cancer protein gets lost. Science News. 148(Nov. 18):334.