doctor frogs

Doctor Frog to the Rescue!

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Scientists are finding new ways to treat sick people by studying frogs!
This is yet another good reason to be concerned about the fate of our worlds frogs since every day so many frogs are threatened by environmental problems! For example, scientists found a way to make a new drug painkiller from the toxins in a frog's skin. The frog (Epibpedobates tricolor) is found in Ecuador. Poison in its skin protects it from predators. They couldn't use the poison itself for humans because it's too powerful (isn't that amazing?), but researchers took the frog poison (its structure) as a model for this new drug.

Frog-Skin Poison Could Yield New Painkiller (article from 1997) WASHINGTON (Reuters) - A lethal poison in the skin of an Ecuadorean frog could lead to a painkiller that may be stronger than morphine but without morphine's side-effects, researchers reported Friday. The new drug, known as ABT-594, would target the same kinds of severe pain now treated by morphine, including pain associated with some cancers and traumatic injury. The compound, developed by researchers at Abbott Laboratories, has shown promise for pain relief in rats and mice, and is currently being tested on humans in Europe to determine its safety, Dr. Michael Williams of Abbott said in a telephone interview. The compound is similar to substances found in the skin of an Ecuadorean frog, which relieves pain but also causes hypertension, neuromuscular paralysis and seizures. The researchers were able to isolate the pain-relieving properties without including the deadly ones. Williams stressed that research into the new painkiller was at an early stage, with preliminary human trials currently proceeding in Europe and no estimate of when such a drug might get to market. However, he said that in tests on animals, there was no sign of addiction, an important advantage over morphine. Some 30 million to 40 million Americans use morphine to relieve pain, despite serious side effects including respiratory depression, dangerous constipation and addiction, according to the journal Science, which published the research.

Scientists are also studying the mysterious Wood Frog, which can freeze during the winter, to find clues that might help develop new tools for safer human organ transplants.

Frozen Frog May Give Docs Jump on Human Transplants Brian Handwerk for National Geographic News March 1, 2005 The common wood frog displays a rare trait called freeze tolerance. When the mercury falls, the animal becomes, to the eye and touch, a frog- shaped ice cube. The way it does this may eventually be copied to aid human organ transplants. "Two-thirds of their body water, or more, freezes," explained Jack Layne, a biologist at Slippery Rock University of Pennsylvania. "The heart stops, the breathing stops. For all practical purposes you'd assume that it was dead." In reality, the frog's metabolism slows to a crawl, and its body temperature drops to between 21� and 30� Fahrenheit (�6� and �1� Celsius). The amphibian's heart and brain cease to function. Frozen frog experts, such as biochemists Ken and Janet Storey of Carleton University in Ottawa, Canada, believe the animals acquired their ability to withstand a deep freeze about 15,000 years ago, during ice age evolution. During winter hibernation, the common wood frog stops its heart and brain and freezes into what looks and feels like a frog-shaped ice cube. Researchers are studying this uncommon ability to gain insights that may aid the process of human organ transplants. Photograph courtesy Slippery Rock University of Pennsylvania Freeze tolerance allows common wood frogs (Rana sylvatica) to live in harsh climates as far north as the Arctic Circle�the only frogs to do so. But they can also be found as far south in the United States as Georgia. The amphibians cannot survive if their body temperature drops below about 20� Fahrenheit (�6� Celsius). But snow pack and other natural insulators can keep the frogs sufficiently warm during their winter hibernation. A key to their survival is a natural antifreeze that prevents the amphibians' cells from dehydrating excessively during the freezing process. Frozen Brains, Hearts During this process, about two-thirds of the frog's body water freezes. The remainder, including water inside cells, remains liquid. Glucose produced by the amphibian's liver lowers the tissue freezing point (in the same way that ammonia lowers the freezing temperature of a car's windshield wiper fluid, which is mostly water.) The glucose limits ice formation in the body and binds water molecules within the frog's cells. This curbs the damage caused by cell shrinkage, which is common with freezing. "Normally under those freezing conditions, without glucose, the cells would dehydrate completely," said Boris Rubinsky, an engineer at the University of California at Berkeley. In a recent issue of Discover magazine Rubinsky published images of temperature scanning electron micrographs (a sort of heat-based CT scan) of frozen common wood frogs. A cross section of a frog's liver illustrates how water remains in the cells. Rubinsky said he has used other imaging technology to study the frogs. "We've done MRIs of frogs. And without harming the animal, we were able to observe the entire process of [the] freezing of a live animal as it happens in nature," he said. "When it thaws, it thaws from the interior out. � [T]he heart begins to thaw first and then the brain and, only at the end, the limbs." In nature and in the lab, the thawing process takes places of a period of several hours. When complete, the amphibians restart their hearts and hop away unscathed. The process is remarkable but not unique. "There are a number of insect species whose body fluids will freeze quite substantially," said Layne, the Slippery Rock University biologist. He added that about six North American frog species, one European lizard, and a handful of North American turtles also withstand deep-freezing. He suspects the ability may also one day be observed in a number of Asian animal species. Other animals use a variety of mechanisms to deal with cold, from hibernation to migration. So why do frogs freeze? Layne believes that in the case of the wood frogs, freezing is somehow related to reproductive strategy. "Most freeze-tolerant [species] like to breed early in the spring," he said. "They lay eggs in ephemeral ponds that develop from snow melt. [The frogs] have to get into those ponds quickly when they get a good melt, because [the ponds] dry up in summer, and that could result in a lost generation." Frogs in nonfrozen deep hibernation, such as on a pond bottom, take longer to emerge from hibernation to answer the call of the spring mating season. While common wood frogs put their freeze tolerance to good use, many scientists are pondering what use humans might make of the process. Better Organ Transplants? "These frogs and turtles are vertebrate animals and share a lot of things in common with mammals, like organ and tissue structures," explained Jon Costanzo from the Laboratory for Ecophysiological Cryobiology at Miami University in Oxford, Ohio. "It begs the question: If a frog can withstand the freezing of all of its organs at the same time, how can we apply that to humans?" One avenue of particular interest to Rubinsky, the Berkeley engineer, and other researchers is the field of organ transplants. "Fifty thousand people in the United States are waiting for a heart transplant, but only about 3,000 will get one," Rubinsky said. Time is a major constraint. In the case of a human heart transplant, doctors have only five or six hours from the time the donor organ is harvested until it must be implanted in the living recipient. The logistics of quickly moving a matched organ from donor to recipient�who are often separated by considerable distance�make many transplants impossible. But slowing the metabolism of the donated organ via techniques like freezing is a possible solution. "It's the kind of problem in which small improvements could make a big difference," Rubinsky noted. "For instance, having 24 hours instead of 6 could provide a lot more organs to a lot more people." Rubinsky has had some success. In 1999 he and colleagues preserved rat livers in a partially frozen state, then thawed and implanted the organs in "recipient" rats�one of which survived for five days. More recently Rubinsky and colleagues at Sheba Medical Center in Israel have made some progress in freezing rat hearts. But the road ahead will be a difficult one. "When it comes to more complicated structures [researchers] just haven't been making much progress," said Costanzo, the Miami University researcher. He believes science would benefit by trying to more closely mimic nature. "I think, in the past, people used techniques that were very different from what the animals are doing," he said. "The animals are cooling very slowly, and the temperature they remain at is really quite high. Just a few degrees below 0� Celsius [32� Fahrenheit]." The cryoprotectants (additives used to preserve frozen tissue) now routinely used for embryo and sperm preservation were unheard-of a half century or so ago. So who knows where future research may lead? Noting the common wood frog, Layne, the Slippery Rock University biologist, said, "You've got an animal here that experiences total cardiac arrest. Its heart stops. When it comes to things like a [human] stroke, this parallels that in a way. You have a cessation of blood flow and then it starts again. "There's always a medical debate about restoring blood flow after blockage," he said. "These frogs start everything back up, and they don't have the injury. The model might [give] some insight when it comes to conditions like heart attack and stroke." Of course, some eye the frogs and ponder the ultimate human application�life preservation by freezing entire bodies of the deceased. While no door is closed, most scientists agree that success in this arena, if possible, is many years down the road. As Layne noted, "Even nature has not evolved a freeze-tolerant mammal."

Frog Groups

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A group of fish is called a School of Fish.
A group of geese is called a Gaggle of Geese.
A group of sea gulls is called a Flock of Sea gulls.
A bunch of cows and bulls is called a Herd of Cattle.But what do you call a group of frogs? Answer: An ARMY of Frogs! And what do you call a group of toads? Answer: An KNOT of Toads!

It's Raining Frogs!

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Throughout history, there have been tales of raining frogs. These stories, as crazy as they may seem, are actually real events! From Biblical tales of Egyptian storms to British towns suddenly finding themselves covered with frogs falling from the sky, such events are caused when a wind storm passes over a pond or lake teaming with frogs, picking them up and dumping them elsewhere!One recent story, from the Press Democrat news services, was in June of 1997.

"CULIACAN, Mexico- It rained toads in the town of Villa Angel Flores.
A small tornado whirled up a cluster of toads from a local body of water Saturday night and dropped them all the town in the Pacific coast state of Sineloa, the newspaper El Debate reported Tuesday.
Motorists reported the amphibians dropping from the sky around 11 p.m."

But these stories are not uncommon - there was a story as recently as June of 2005 when a Belgrade paper reported a similar incident in Serbia.

Thousands of tiny frogs rained on a town in north-western Serbia, Belgrade daily Blic reported on Tuesday.
Strong winds brought storm clouds over Odzaci, 120km north-west of Belgrade, on Sunday afternoon, but instead of rain, down came the tiny amphibians, witnesses said.
"I saw countless frogs fall from the sky," said Odzaci resident Aleksandar Ciric.
The frogs, different from those usually seen in the area, survived the fall and hopped around in search of water.
Belgrade climatologist Slavisa Ignjatovic described the phenomenon as "not very unusual".
"A wind resembling a tornado can suck in anything light enough from the surface or shallow water. Usually it's just dust, but sometimes also larger objects," Ignjatovic told Blic. - Sapa-DPA

Frogs and Myth

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Lots of different cultures have all kinds of interesting myths pertaining to Frogs.

Frogs and Weather Frogs have been associated with weather in a lot of ancient cultures. I guess this really makes a lot of sense if you consider that they tend to make a lot of noise before rain storms. Some Australian aborigines and Native American groups believed that frogs were the bringers of rain. In India, frogs were believed to personify thunder in the sky. Even the word for "frog" also meant "cloud" in Sanskrit! In China, they see the "TOAD", not the "man" of the moon. The toad is also considered "one of the five poisons of yin." They say that eclipses happen when the "toad in the moon" tries to swallow the moon itself!

Frogs and Luck Sometimes, cultures associated frogs with good and bad fortune. In Japan, frogs are the symbols of Good Luck. One myth I read dealt with the idea that bullfrogs are descended from a great ancestor who could suck all the mosquitoes out of a whole room in a single breath! Some myths are less favoring to frogs and toads. Some folklorists* have claimed that "If the first frog that you see in the spring is sitting on dry ground, it signifies that during the same year you will shed as many tears as the frog would require to swim away in." If, on the other hand, the first frog of spring jumps into the water, you'll experience misfortune all year! However, if the springs' first "hoptoad" come jumping in your direction, you will have many friends; if it jumps away from you, you will lose some. (sounds to me like it's best not to run into the first spring frog!) Some less enlightened people associate frogs, and Toads in particular, as evil incarnations of demons or devils!

Frogs and Warts Some say that you get warts from touching frogs and toads. You get warts from human viruses, not from frogs and toads! Frogs have slimy skin to stay moist when it is dry, and toads have bumpy skin to help camouflage them in their habitat. Some frogs and toads have paratoidal glands which secrete poisons as protection which can cause skin irritations and may be poisonous to some species of animals, but warts have nothing at all to do with the frogs themselves!

The French and the Frogs For some reason, the French have been given the nickname Frogs...There are many different theories about how this came to be... The story I had always heard was that the nickname dates waaay back to sometime around the 18th century, when Paris was surrounded by many swamps...The French nobility that would visit Versailles apparently tended to refer to Parisians as frogs because of the swampy surroundings...and only later did the term get picked up to describe the French in general. Another story I've heard was that American soldiers adopted the nickname for the French during the World War II because they ate frog legs and hid well when camouflaged. I've also heard that a frog used to be on the French Flag, before the Fleurs de Lis was adopted when King Clovis took the throne....

Frogs, Toads and Phobias Batrachophobia- Fear of amphibians, such as frogs, newts, salamanders, etc. Ranidaphobia- Fear of frogs. Bufonophobia- Fear of toads.

Jurassic Frog

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The earliest known frog appeared during the late Jurassic period, about 190 million years ago! Scientists believe that the oldest frogs developed jumping legs to avoid being eaten by dinosaurs.
Specimens on the first known frogs have been found on Navajo Indian reservations in Arizona. Fossils of meat-eating fish and reptiles such as dinosaurs have also been found at the same site.
These fossils show that the skeletal shape and body plan of the frog has remained almost unchanged over the last 190 million years. In addition, frogs had the added advantage of being small enough to be able to hop away to avoid the many predators which habitated its surroundings."

Strange Breeding

Surinam Toad

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The Surinam toad, an aquatic South American toad (family Pipidae), is about 20 cm (8 inches) long. It has small eyes, a flat, squarish body, and a flat head with loose flaps of skin on the face. Its "fingers" have little star-shaped appendages that help them find food.

Photo sent in by J. Powers of Bloomington, Indiana

These bizarre creatures are well known for their weird brooding habits.
They mate in the water, and as the eggs are released the male fertalizes them and presses them to the back of the female.
In the next several hours, the skin grows around the eggs to enclose them in a cyst with a horny lid.
After about 80 days, the eggs develop, and the young emerge out of the back of this toad as a bunch of tiny froglets!

Darwin's Frog

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Another strange frog is the Darwin's frog (Rhinoderma darwinii).
This is a small (1 in./3 cm. in length) frog, species of the (small) family Rhinodermatidae. It got it's name after the fact that Charles Darwin discovered it on his world voyage.
This frog lives in the cool forest streams of South America, mostly in Argentina and Chile.
This frog also has odd brooding habits. The female lays about 30 eggs and then the male guards them for about 2 weeks. Then the male picks up all the survivors and carry around the developing young in their vocal pouch. The tadpoles develope in their baggy chin skin, feeding off their egg yolk. When they are tiny froglets (about half an inch) they hop out and swim away!
Weird!

Gastric Brooding Frog

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Yep...that's a baby frog coming out of a tiny mama frogs' mouth.
This species of frog, called the Gastric Brooding Frog, incubates its' young inside it's tummy...then the frogs come hopping out of the mouth when they develop past the tadpole stage. Scientists were most intrigued by how this species manages to "Turn off" production of hydrochloric acid (the digestive juices) when brooding the froglets.
The Gastric Brooding Frog was found in Australia. Sadly, not long after their discovery they dissapeared and are now believed to be extinct. Also- Yes! That is a thumb you see behind the frog, to show how tiny even the mama is.

dry region frogs

Frogs and Weather

Desert Frogs

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The Catholic frog (Notaden bennetti) is a yellow or greenish Australian myobatrachid which gets to be about 4 cm (1.5 inches) long. It was named for the dark, crosslike pattern on its back, and it lives in dry regions. The way it copes with drought is to live underground, emerging from its burrow after a heavy rain.

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Another desert dweller is the Flat-headed frog (Chiroleptes platycephalus) which is also an Australian myobatrachid. It, too, lives in burrows and is noted for its' ability to store enough water in its body to take on a ball-like shape. *bloat*

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Another dry-region dweller, the Rheoba trachus Silus, swallows its eggs and broods them in its stomach since there aren't any ponds available!!! *YUM!*