Copyright 2000 The Chronicle Publishing Co.
The San
Francisco Chronicle
NOVEMBER 27, 2000, MONDAY, FINAL EDITION
SECTION: NEWS; Pg. A9; SCIENCE REPORT
LENGTH: 603 words
HEADLINE:
SCIENCE REPORT
SOURCE: Chronicle News Services
BODY:
New Tests Pinpoint Where Cocaine Was Grown
Cocaine traffickers may be selling one of their secrets on the street.
In the journal Nature, scientists say they have figured out how to trace
cocaine to the region where the original coca plants were grown.
Researchers from the University of Utah in Salt Lake City and the Drug
Enforcement Administration in McLean, Va., found they could trace 96 percent of
cocaine samples to distinct regions of South America, using two chemical
measurements. The scientists collected 200 sets of leaves from plants growing
along the Andean Ridge in northwestern South America, the primary growing region
for coca. Plant extracts were analyzed for the ratio of certain forms of carbon
and nitrogen. The researchers also measured concentrations of the chemicals
trimethoxycocaine and truxilline.
By combining the two sets of
measurements, the scientists found that plants from different regions in
Colombia, Peru and Bolivia had distinct chemical signatures. Soil conditions and
humidity probably account for the difference.
The researchers said the
new method gives drug officials more options for identifying source regions and
trafficking routes.
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Ancient Sites Yield Tips To Store Nuclear Waste
In their search
to make the United States' nuclear waste safe, scientists have been going to
some pretty unlikely places.
Like great pyramids of Egypt, and French
caves with prehistoric paintings. But this work isn't a tour of the world's
ancient wonders. Rather, it aims to understand how well archaeological sites
have stood the test of time - just as one day, the proposed permanent nuclear
waste dump at Yucca Mountain, Nev., may have to.
John
Stuckless of the U.S. Geological Survey in Denver, Colo., recently described
some human accomplishments that had endured for at least 10,000 years, the
length of time Yucca Mountain must also remain safe.
Prehistoric cave paintings in southern France and Spain have remained
dry despite thousands of years of natural seepage within the cave, Stuckless
reported. One of the big questions about the controversial Yucca
Mountain dump is whether groundwater might flow around or get into the
nuclear waste canisters.
Similarly, an underground monastery in
Cappadocia, Turkey, has remained essentially dry since the second century, even
though water occasionally seeps through fractures in its walls.
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Proteins in HIV Found To Spread Infection
The AIDS virus uses a
protein complex that does housekeeping chores inside cells to spread disease to
other cells of the body, researchers say.
Studies published in the
Proceedings of the National Academy of Sciences report that a group of proteins
called proteasomes are used by HIV to assemble new viral particles and to spread
those new particles to uninfected cells.
Ulrich Schubert of the National
Institute of Allergy and Infectious Diseases said test tube studies show that
blocking the action of the proteasome proteins can reduce the spread of HIV
infection by about 98 percent.
Schubert, an author of one study,
cautioned that the research was conducted only in test tubes, and said it is not
known whether the proteasome inhibitors would work against HIV in humans.
"We would never inject this drug into an HIV-infected person, because we
do not know what would happen," Schubert said.
The proteasome inhibitors
will be tested in monkeys before any human tests are considered. The animal
studies could take months, Schubert said.
LOAD-DATE:
March 20, 2001 
