medical research


Dusky Gopher Frogs are one of the most endangered frogs in the US, with possibly only around 100 animals surviving in the wild. Around 1,400 tadpoles were produced by Henry Doorly Zoo, using eggs collected from one of their female frogs, and sperm collected from males at Henry Doorly Zoo and from males at Memphis Zoo.

This is the first time that sperm has been collected from frogs at one zoo, transported to a second zoo, and used to successfully produce tadpoles. Hopefully, processes like this one will be used more often to bolster the numbers of endangered amphibians in captivity.

More information on this story is available on the Omaha.com web site.

Another example of the medical miracles that frogs can reveal to make life better for humans. Full story here. An excerpt:

New research on amphibians could soon give researchers a leg up on how limbs develop in a host of organisms, and one day lead to techniques to repair injuries in humans.

Dalhousie post-doctoral researcher Ryan Kerney’s work in figuring out how a frog found in Puerto Rico’s rainforests develops its limbs has just been published in the journal Evolution and Development.

The emerging field of regenerative medicine is watching this type of research closely hoping to understand how limb development findings could be applied to humans. Regenerative medicine looks at how stem cells can be used to regrow missing structures or guide in the development of structures within an organism.

Amphibians are prominently featured in a new book that explains how a loss of biodiversity hurts medicine. The book, “Sustaining Life: How Human Life Depends On Biodiversity,” was written by Eric Chivian and Aaron Bernstein from the Center of Health and the Global Environment of the Harvard Medical School. The forward was written by Edward O. Wilson. Below are excerpts from a Reuters news story. But the bottom line is this: put these endangered species on “the ark” — the rescue program directed through Amphibian Ark — or lose more medical breakthroughs that would improve the human condition.

The book highlights many examples of potential drugs. The southern gastric brooding frog, found in Australian rainforest in the 1980s, raised their young in the female’s stomach using enzymes that preliminary studies showed could be used to treat human ulcers. But the frogs became extinct.
“The valuable medical secrets they held are now gone forever,” said Eric Chivian and Aaron Bernstein, the key authors of the book from the Center of Health and the Global Environment of the Harvard Medical School, in a statement released by the United Nations on Wednesday.
Treatments from frogs alone include toxins from the Panamanian Poison Frog that could be useful for heart disease, painkillers from the Ecuadorian Poison Frog, anti-bacterial compounds from the skin of the African Clawed Frog, and compounds from the Chinese Large-Webbed Bell Toad that dilate blood vessels and so could treat high blood pressure.
Frog glue could repair cartilage and other tissue tears in humans, but climatic changes have to led to habitat loss and mutations in frogs. The United Nations is leading talks for a new climate pact to limit emissions of heat-trapping gases.
“Amphibians are particularly sensitive,” said Achim Steiner of the U.N. Environment Programme, in a press conference at an environment summit in Singapore.

Image from Wikipedia

One of the discoverers of the lungless frog on Borneo in Indonesia says in an Associated Press story that the Barbourula kalimantanensis looks “like a squished version of Jabba the Hutt.” So, Star Wars fans, you decide! Excerpt from the story:

“These are about the most ancient and bizarre frogs you can get on the planet,” (biologist David) Bickford said of the brown amphibian with bulging eyes and a tendency to flatten itself as it glides across the water.

“They are like a squished version of Jabba the Hutt,” he said, referring to the character from Star Wars. “They are flat and have eyes that float above the water. They have skin flaps coming off their arms and legs.”

A helpful explanation from the latest story I’ve come across:

While many frogs breathe partially through their skin, the Barbourula kalimantanensis is the first to have entirely evolved away from having lungs … This runs counter to one of the key events in evolution, when animals developed primitive lungs and moved from water to land.

“Here is a frog that has reversed that trend, it has totally turned against the conventional wisdom, if you will, of millions of years of evolution,” said Bickford, a biologist at the National University of Singapore.

The frog appears to have shed its lungs over millions of years to adapt to its home in the fast-flowing cold water rivers in the island’s rainforests, Bickford said.

Cold water contains more oxygen, making it possible to breathe through skin, he added.

New to the amphibian crisis? Learn more here.

The Houston Zoo’s blog has a solid post that summarizes how and why amphibians hold the key to new medicines:

More than 200 beneficial chemicals known as alkaloids have been extracted from frog and toad skin. For the amphibians, these poisonous alkaloids serve as a natural chemical defense, affecting the muscles and nerves of predators.   Medical research, however, has uncovered numerous beneficial uses for these same substances.  One alkaloid produced by amphibian skin is a highly effective painkiller, 200 times stronger than morphine.  Yet it is not addictive like morphine. Skin secretions from the green treefrog have been shown to stimulate activity in the human pancreas and intestine, and commercial drugs are now available based on these compounds. The large parotoid glands of toads, located just behind the eyes, produce two substances that affect the adrenal and cardiovascular systems in humans. A third secretion from these same glands is a powerful hallucinogen.  Further research may very well yield new medicines from these compounds.

 

Frog skin secretions also can have powerful antibiotic properties. The skin of the African clawed frog, once again, produces protein-like chemicals called  peptides that help heal cuts and bruises, which may provide doctors with a whole new class of antibiotics in the years ahead. Research suggests that skin secretions of some frogs may also help repair human internal organs following surgery.

Frogs matter. They’re the canaries in the coal mine. And their skin is a medical marvel, possessing secrets that can lead to new drugs. Here’s excerpts from a story from BBC yesterday:

Skin secretions from a South American “shrinking” frog could be used to treat type 2 diabetes, researchers say. A compound isolated from the frog, which grows to 27cm as a tadpole before shrinking to 4cm in adulthood, stimulates insulin release. A synthetic version of the compound – pseudin-2 – could be used to produce new drugs, delegates at the Diabetes UK annual conference heard. Around two million people in the UK have type 2 diabetes. The condition, which is often associated with being overweight, develops because the body does not produce enough insulin, or when the insulin that is produced does not work properly. It means people cannot regulate their blood glucose levels properly.

Scientists from the University of Ulster and United Arab Emirates University have tested a synthetic version of pseudin-2, a compound which protects the paradoxical frog from infection…The synthetic version was better at stimulating insulin than the natural compound, opening the way for it potential development as a drug for treating diabetes.

Study leader Dr Yasser Abdel-Wahab, senior lecturer in biomedical sciences at the University of Ulster, said there had been a lot of research into bioactive molecules from amphibian skin secretions. One recently developed diabetes drug – exenatide – was developed from a hormone in the saliva of the Gila monster – a lizard found in south-western United States and northern Mexico.

Story from BBC NEWS:

http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/7270714.stm

New research is showing that the rana esculenta, or edible frog, of Europe could lead to the discovery of new classes of antibiotics, which is an urgent need in the medical industry. The abstract of the report states that the rana esculenta possesses an “attractive molecule for use in the development of new compounds for the treatment of infectious diseases.” Why this is important:

“Due to the widespread resistance of bacteria to the available drugs, the discovery of new classes of antibiotics is urgently needed, and naturally occurring antimicrobial peptides (AMPs) are considered promising candidates for future therapeutic use. Amphibian skin is one of the richest sources of such AMPs. “

Here’s great video explaining what happens with that wood frog that in the winter freezes solid, stopping its heart, and comes back to life in the spring. This is the type of medical miracle we can’t lose.

Here’s a new story about Manchester University (UK) researchers who have discovered the potential for yet more miracle drugs made possible by amphibians. Excerpt:

“Manchester University researchers are exploiting the ability of some amphibians to regrow limbs. ‘Human and amphibian proteins are very similar,’ said one of the researchers, Professor Enrique Amaya. ‘That means the lessons you learn from frogs and salamanders are applicable to humans. Their embryos – spawn – are also easier to study.’”

“The secret powers of frogs are being exploited by scientists to create drugs that will correct disfiguring facial scars and could one day help in the regrowth of amputated arms and legs.”

It’s American Diabetes Month, and it turns out the medical marvel of the frog once again has something to offer. The wood frog in Alaska may hold secrets that could create new diabetes control drugs. Here’s the story. And here’s the key excerpt:

Unlike most frogs, which spend the winter under water, in flowing streams or buried in the mud, the wood frog moves to dry land and prepares to freeze.

“They control the freezing process within their bodies,” (Carroll College biology profession Grant) Hokit said. “The problem with you or I freezing is, the water inside our cells ends up crystallizing and destroys the cells. But just before the frog freezes, it dehydrates its cells so the ice crystals end up forming between the cells and between the tissue layers.”

Insects, a handful of amphibians and fewer reptiles have the ability to survive freezing, Hokit said. Some attempt to avoid freezing by pumping their bodies full of natural antifreeze, like glucose.

The frog’s ability to manipulate its sugar metabolism is now of scientific interest.

“This frog may have a lot to teach us about how to control diabetes,” Hokit said. “There are many researchers studying this and other amphibians, trying to determine how it can flood its body full of glucose and not suffer the ill effects of that, which we see in humans.”

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