Hi Sylvia--Thanks for the very interesting information about cones and the good
things that can come from them.  My husband and I are going to Fiji and have
just put out a note on the Conch-L requesting information on  how to handle
poisonous/deadly cones when we find them.  We'd like to collect some cones while
we are there, but have no idea how to pick up or otherwise handle cones that may
be dangerous to us.  Can you give us any tips?  Thanks.
 
>>> Sylvia S Edwards <[log in to unmask]> 12/20/97 10:48am >>>
I believe you are the one who wanted information on cone shells.  Here's
something you won't find on Conch-L:
 
Sylvia Edwards
Huntsville, Alabama
---------------------------------------------------------
Painkiller from the sea
 
By Graeme O'Neil
 
(Sunday Herald Sun, April 21, 1996, p. 5)
 
(transcribed and annotated by Dr. Bruce Livett)
 
The venom of some of the Pacific Ocean's cone shells, has shown
extraordinary promise in controlling chronic pain.
 
Recent experiments in the United States have shown a synthetic molecule
based on one of the paralyzing neurotoxins in the venom of the magician's
cone shell , almost magically blocks acute pain in patients who no longer
obtain relief from opiate drugs (see References below). These include
terminally ill cancer and AIDS patients with chronic pain and long-term
amputees with "phantom limbs".
 
Dr. William Brose, director of a pain clinic at Stanford University
School of Medicine in San Francisco, says the compound called SNX-111,
developed by the biopharmaceutical company Neurex, is 100 to 1000 times
more potent than morphine.
 
Cone shell venom expert Professor Jim Angus of Melbourne University's
Department of Pharmacology, describes the US research as a "tour de
force", and says Australia stands to reap a bonanza from the venoms of
its own cone shells - there are now more than 70 species on the Great
Barrier Reef and many others around the Australian coast, including
several in Victorian waters.
 
Australian researchers are doing "fantastic work" on the rich cocktail of
neurotoxins in native cone shell venoms. Prof. Angus's research team has
been studying cone shell venoms for more than five years to determine
their effect on nerves and muscles.
 
Prof. Angus's group is collaborating with the Centre for Drug Design and
Development at The University of Queensland, led by Dr. Peter Andrews, as
is Dr. Bruce Livett at the Department of Biochemistry and Molecular
Biology at Melbourne University who heads another group collaborating
with Dr. Paul Alewood and colleagues at the Centre for Drug Design and
Development in Brisbane.
 
Various Conus species paralyze and eat a wide range of marine creatures
including fish, worms and other molluscs. They extend a proboscis-like
organ with a harpoon-like tip, firing venom into their prey, inducing
paralysis and death in seconds.
 
Cone shells have killed humans who have innocently picked them up - the
geographers cone, Conus geographus , found on the Great Barrier Reef, has
killed at least 20 people in Australia and the western Pacific.
 
Western medical researchers initially became interested in conotoxins
when a medical researcher at the University of the Philippines in Manila,
 Dr. Baldomero Olivera , reported some species could paralyze fish within
seconds.
 
Prof. Angus says cone shell venoms very enormously in composition. The
venom of some species contains up to 90 different peptides - small
protein fragments - that exhibit powerful, highly selective activity on
nerves.
 
"They seem to change their peptide fingerprints almost at whim," Prof.
Angus said.
 
"From day to day, the proportion of peptides changes, and new compounds
appear while others disappear from the venom".
 
The cone shell's strategy in proving a bonanza for drug researchers
looking for new painkillers - the tiny peptide molecules have highly
specific effects on a wide range of molecular targets in nerve cells.
 
Neurex's prototype drug SNX-111 now in the final stages of clinical
testing before commercial release, is an N-type calcium channel blocker ,
omega conotoxin MVIIa [The omega conotoxin MVIIa structure, (PDB file),
can be found in the PDB, ID code 1omg. Click here for a full scientific
paper on the structure (by NMR) and related papers ].
 
[Follow these links for a scientific article about the NMR solution
structure of a related omega conotoxin conotoxin MVIIc , a 'P'-type
calcium channel blocker from Conus magus, and a molecular graphic of
conotoxin MVIIc . For a larger annotated molecular graphic (takes some
time to download), see big molecular graphic . The omega-conotoxin MVIIC
structure can be found in the PDB, ID code 1OMN, T7094 for the
coordinates T7905 for the restraints].
 
Prof. Angus says nerves are activated by an influx of calcium ions to the
cell's interior, which in turn triggers the release of compounds that
transmit signals between nerves, including the signals that carry pain.
 
The SNX-111 conotoxin molecule is just the right size and shape to block
the tiny pores in the nerve cell's membrane through which the calcium
ions flow - with the calcium channels blocked, the nerve can not transmit
pain signals and the patient is relieved.
 
Most patients with intractable pain eventually become tolerant of
powerful opiate drugs much as morphine and pethidine, even at dosages
1000 times higher than those that would kill a normal person.
 
Dr. Brose's Stanford study infused SNX-111 directly into the spine of
seven volunteers, who had suffered chronic pain for more than 35 years
after amputations or nerve damage.
 
They used a tiny pump that delivers a constant dosage of the drug. After
three days, five of the seven patients reported their pain had
disappeared.
 
The only side-effects were mild eye jitters and a slight drop in blood
pressure - patients on heavy doses of opiates are normally lethargic and
suffer impaired intellectual function.
 
One female patient was able to reduce the daily cost of her opiate drugs
from $6000 to only $100; SNX-111 seemed to reverse her tolerance of
opiates.
 
The US researches used direct-infusion because peptides tend to break
down in the digestive system.
 
Prof. Andrews' team in Brisbane is trying to develop synthetic, oral
analogues of conotoxins - drugs that mimic the action of the natural
conotoxins, but which would be absorbed through the digestive tract
without breaking down.
 
References:
 
Buchan, A. M. et al. (1994) J. Cereb. Blood Flow Metab., 14, 903-910.
 
Concar, D. (1996) "Doctor snail". New Scientist, 19 October, 278:
pp.26-28.
 
Gibbs, W.W. (1996) A new way to spell relief: V-e-n-o-m. A toxin from
killer sea snails promises a better painkiller ". Scientific American 274
(2) February (1996), 20-21.
 
Olivera BM., Cruz LJ., de Santos V., LeCheminant GW., Griffin D., Zeikus
R., McIntosh JM., Galyean R., Varga J., Gray WR., et al (1987) Neuronal
calcium channel antagonists. Discrimination between calcium channel
subtypes using omega-conotoxin from Conus magus venom. Biochemistry 26:
2086-90.
 
Smith, M. L. and Siesjo, B. K (1992) in Pharmacology of Cerebral Ischemia
(Krieglstein, J. and Oberpilcher, H., Eds) pp. 161-167,
Wissenschaftiliche Verlagsgesellschaft Stuttgart, Germany.
 
 
SNX-111 :Follow this link for a compilation of references on Conotoxin
MVIIA (SNX-111) structure and function
 
 
For more information about cone shells, their venoms, conotoxins and
actions, see:
 
Charmaine's Killer Snail Home Page , maintained by Dr. Livett at URL,
http://grimwade.biochem.unimelb.edu.au/~bgl/content.htm
 
This HomePage also contains links to other web sites of interest.