Think tank

By Graeme O'NeillNovember 14, 2005
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It's early days, but baby boomers approaching the high-risk age for Alzheimer's might keep an eye on an experimental drug being developed by Melbourne company Prana Biotechnology.
Healthy young human volunteers in a just-completed phase I trial in Holland showed no adverse reaction to Prana's PBT2. Also, the drug enters the brain more readily - by a factor of 20 - than Prana's first-generation compound, the discarded antibiotic clioquinol.
Early tests with clioquinol showed the metal-chelating molecule traps and removes the copper and zinc ions that cause a toxic protein, beta amyloid, to aggregate in brain tissues. It quenches the oxidising reactions that kill neurons en masse.
Clioquinol dramatically improved the performance of transgenic mice with Alzheimer's in maze tests. It also reduced serum levels of beta amyloid in humans with advanced Alzheimer's and markedly slowed their cognitive decline - a first for any AD drug.
Excuse me!
Intense selection for desirable physical and production traits is still driving rapid evolution in modern livestock breeds, in surprising ways. Hamilton, New Zealand company Dexcel is trying to reduce methane from dairy herds. The average NZ Holstein-Friesian dairy cow belches 35 litres of the potent greenhouse gas daily, produced by microbial fermentation in the rumen, the large foregut chamber in all ruminants.
Dexcel researcher Dr Gary Waghorn says halving this loss of dietary energy could increase milk yield by up to 8 per cent.
Waghorn recently discovered why NZ's Holstein-Friesians eclipse their northern hemisphere progenitors in milk production. Farmers and breeders, through intense selection for fast eaters and high productivity, unwittingly doubled the breed's rumen capacity and changed its behaviour. Rather than eat and digest on the fly, Kiwi cows pack it away by day, and sleep on it.