Thursday, December 13, 2012

Jellyfish Stings Might Be Best Treated With Zinc

Aquatic Life


The deadly Chironex fleckeri; even mild stings are painful.

Jellyfish stings are painful and can be life-threatening. An article by Chritie Wilcox in Scientific American shows how one scientist, Angel Yanagiharabitten by jellyfish in 1997, looked to find not only how the venom within the jellyfish (Chironex ) releases its toxins,but also whether she could find an effective antidote for such painful attacks.

Wilcox writes:
When human flesh brushes up against a jellyfish tentacle, the tiny stinging cells jellies carry, called cnidocytes, can discharge their painful venom in as little as 700 nanoseconds. During the winter months, Australian waters are home to an abundance of the deadliest jellyfish in the world, the box jelly Chironex fleckeri, which has been known to kill a person in less than five minutes.
Chironex even looks scary, with a bell that can be large as a basketball and tentacles up to ten feet long carrying millions upon millions of stinging cells. But Chironex didn’t earn its title as the deadliest jellyifish in the world based on looks. Anyone who has come in contact with Chironex knows its fearsome reputation is justified, as even mild stings are excruciating. Yet despite decades of research, exactly how Chironex and other jellies deal their sometimes-fatal blows has remained a fearsome mystery.
“For over 60 years researchers have sought to understand the horrifying speed and potency of the venom of the Australian box jellyfish, arguably the most venomous animal in the world,” explains Yanagihara. It’s not that scientists have been unable to isolate any toxins. Yanagihara’s initial work discovered pore-forming toxins called porins in a related species, Carybdea alata, capable of tearing holes in blood cells, and since scientists have found similar porins in every jellyfish species they’ve looked at. The conundrum is that severe sting victims don’t suffer from profound destruction of red blood cells, seemingly counting out the porins as the cause of fatal stings. But if it’s not the porins, what in jellyfish venom is to blame? How does it act so quickly, leading to such sudden cardiovascular collapse? And is there anything we can do to slow or stop its deadly activity?
Now, in a new paper published today in PLOS ONE, Yanagihara and her colleagues from the University of Hawaii have revealed the key mechanism by which Chironexvenom—and, specifically, the overlooked porins—quickly dismantle the cardiovascular system. Armed with physiology, the team was able to find a safe treatment that could be used to improve survival in sting victims.
This treatment is zinc gluconate, which is more effective than the commercially available antivenom; in animal studies,it was twice as effective as what is now used. The article adds:
Zinc gluconate isn’t a cure-all; it won’t stop all of the excruciating pain associated with severe stings, and victims are still at risk of going into shock and cardiovascular failure. But, Yanagihara is hopeful that treatment with zinc gluconate might be effective enough at prolonging survival in severe sting victims long enough to get them to medical professionals that can save their lives, and may provide welcome relief to mild sting victims.

That would be a good thing since dozens of persons in Australia and the Philippines die each year from such jellyfish stings.

You can read the rest of the article at [Scientific American]