You've seen the artificial nose that sniffs out drugs and explosives, now comes the tongue on a chip. Chemists John McDevitt and Eric Anslyn working with computer engineer Dean Neikirk at Texas University in Austin, have made a silicon chip with microscopic wells etched into its surface, which they say can act as tiny taste-buds. Each well holds a minute plastic bead coated with sensitive chemicals that change colour depending on whether molecules with a sweet, sour, salt or bitter taste touch them.
The tongue-on-a-chip could be used in medicine to taste test cholesterol in the blood or by environmental scientists to sample polluted water, according to McDevitt. The tongue could even be used to 'taste' solid rock, he adds. By using a chemical 'saliva', the tongue doesn't need to 'lick', 'We use a Q-tip to add samples to it,' he explains. The artificial tongue would be able to work longer hours than human tasters in the food and drinks industry and by connecting it to a computer via a colour video camera to detect the colour changes, the tasty information could be used to automatically control ingredients added to a batch to make sure the product tastes just right. (J. Am. Chem. Soc., 1998, 120, 6429)
A possible link between the reported increased incidence of childhood cancers, such as leukaemia near electricity power lines an high-voltage installations has been uncovered by British scientists. It turns out that the electric field itself is not to blame but its effects on pollution. Denis Henshaw of Bristol University reported the findings at a meeting of experts in the field in Bristol last autumn.
Pollution from vehicles, industry and households can be found almost everywhere as tiny aerosol particles in the atmosphere. Fortunately, our bodies can usually cope with low concentrations of such particles because we have evolved defence mechanisms to help protect us from natural pollutants, including bacterial and viral particles. Electric fields, however, attract these aerosol particles, just as dust is attracted to a TV screen. Areas around high voltage electrical equipment can have far higher levels of pollution than normal, says Henshaw.
The researchers measured aerosol particles around power lines and found that the electric field the particles to oscillate causing them to 'plate out' and making them stick to skin more easily. They also found that charged particles in the air around power lines - known as corona ions - can have three effects. First, the increased charge from the corona ions increases plate-out. Secondly, corona ions convert gaseous pollutants into ultra-fine aerosols which when inhaled are more likely to be trapped in the lungs. Henshaw believes there is a third effect too in which the ion charge increases the existing electrical charge in the aerosols so that when inhaled they will effectively stick in the lungs. Henshaw adds that corona ions can be measured as far as five miles away.
'This is not a scare story,' emphasises Henshaw, 'we believe this is the answer to the riddle of why some cancers are more common around power lines and hope it will lead to a public debate'.
A drug that fools muscle into behaving like well-exercised and toned flesh without you having to lift a finger might one day be possible, according to American scientists. Sanders Williams' team at the University of Texas Southwestern Medical Center has discovered a genetic switch that tells muscle whether to behave as 'fast strength' muscle - the type weight-lifters have or 'slow endurance' muscle, which aerobic fans get.
The researchers found that three proteins - calcineurin, NFAT and MEF2 - work together triggering special genes depending on quantity and type of exercise. The genes then boost endurance muscle proteins. 'When people go jogging, molecular events happen in the muscles they are exercising that both enhance their capability to exercise further and improve their health,' says Williams. He adds that a drug to restore endurance muscle tissue in people who cannot exercise properly such as heart patients could artificially switch on the genes to mimic the activity of the three proteins. Stimulating or reversing the protein signals would do what exercise does naturally and so change the quality of one's muscles. (Genes and Development, 1998, 12, 2499)
The US Navy has come up with something of an oxymoron - an environmentally friendly rocket fuel for missiles and ballistic weapons. The fuel is based on a hydrogen peroxide a chemical more commonly known as a household bleach and hair perming agent.
Eric Saikin and his team at the Naval Air Warfare Center Weapons Division, in China Lake, California, have used pure, concentrated hydrogen peroxide and a catalyst - which they cannot reveal, that breaks the peroxide down into water and oxygen giving off large amounts of heat at the same time. The researchers say just mixing the chemicals kicks the reaction off so they do not even need an ignition source.
Hydrogen peroxide is far less toxic than common rocket fuels such as hydrazine and breaks down without forming polluting nitrogen oxide gases or carbon dioxide. Saikin adds that the fuel would not have only military applications but is powerful enough to be used to boost satellites into orbit and with more development may even be used as a fuel for cars.
American biochemists have come up with another use for an experimental drug for cancer that might one day help patients paralysed by spinal injuries regain feeling and even walk again.
Carl Hellerqvist of the Department of Biochemistry at Vanderbilt University in Nashville, Tennnesse has found that a compound made by pharmaceutical company Carbomed Inc, Brentwood, TN and named CM101 can lead to a dramatic recovery in walking ability of experimental mice with spinal injury within 2 to 12 days ).
CM101 is a string of sugar-like molecules (GalNAc/GlcNac/Gal/Gly) and is produced naturally as a toxin by bacteria known as group B streptococci. CM101 can stop blood vessels growing in a tumour which effectively cuts off the oxygen and nutrient supply to the cancerous growth. Hellerqvist and his team reasoned that the process might also stop the growth of scar tissue that prevents nerves healing properly in the spinal cord after an accident. The early laboratory studies bode well for using CM101 to treat spinal injury and so avoid long-term paralysis. (Proc. Natl. Acad. Sci. (USA), 1998, 95, 13188)