Friday, December 4, 2009

Growing back an arm or a leg

I am amazed by how my Axolotl Sally's leg is growing back! I'm unsure how it was removed in the first place , but perhaps Xena mistook it for her favourite food - a worm!.. If only humans were able to regenerate limbs like this , I think that scientists need to keep exploring ways to make this possible for human kind!.. This has prompted me to do my own online research on the matter and well call me slow but it seems that the scientists are already on the ball with human cell regeneration but it's going to be awhile before we are able to grow back limbs..

What amazing little creatures!


Sally's Leg after about a month and the 'fingers' are forming

Sally & Xena

The Axolotl - Creature Feature

Commonly known as Mexican Walking Fish, Axolotls are actually amphibians like frogs and toads.

Amphibians usually develop from an egg into a larval form and finally into an adult. But axolotls remain in their larval form throughout their life. If they did grow to adulthood, axolotls would look just like their closest relative, the Mexican Salamander.

Salamanders live on land but axolotls are completely aquatic. They do have lungs but breathe through their gills and also through their skin.

Axolotls only need to be fed every two or three days. They eat tadpoles, soft insects, worms and even small fish but can also be fed small pieces of raw meat.

An aquarium for Axolotls should have water at least 15-20cm deep and between 14-20 degrees Celsius. Other fish shouldn't share the tank or they could be eaten and if there are too many axolotls in one tank they might fight.

Luckily, if your little axolotl loses a leg it will grow back! Axolotls are famous for their amazing healing abilities. They can regenerate almost any injured part of their body, including the limbs, tail, skin, and even major organs like the heart, liver and kidney.

The most common colours for axolotls are shades of grey and brown but there are also golden albino, white albino, black and spotted varieties.

Axolotls can grow to be as large as 20-40cm and live for as long as 10-15 years.

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A video by the Max Planck Society regarding the regeneration qualities of the Mexican salamander. The researchers believe that humans lost the ability to completely regenerate during the course of evolution. It is, however, possible that this ability has only been suppressed and could somehow be reactivated in the future.

An adult Salamander can regenerate a full leg in 10 weeks. Scientists are hoping that studying the regeneration of the axolotl they can someday apply it to humankind in helping skin or organs to heal better.


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Regeneration in amphibians (wikipedia)

In salamanders, the regeneration process begins immediately after amputation. Limb regeneration in the axolotl and newt have been extensively studied. After amputation, the epidermis migrates to cover the stump in less than 12 hours, forming a structure called the apical epidermal cap (AEC). Over the next several days there are changes in the underlying stump tissues that result in the formation of a blastema (a mass of dedifferentiated proliferating cells). As the blastema forms, pattern formation genes – such as HoxA and HoxD – are activated as they were when the limb was formed in the embryo.[2][3] The distal tip of the limb (the autopod, which is the hand or foot) is formed first in the blastema. The intermediate portions of the pattern are filled in during growth of the blastema by the process of intercalation.[1][2] Motor neurons, muscle, and blood vessels grow with the regenerated limb, and reestablish the connections that were present prior to amputation. The time that this entire process takes varies according to the age of the animal, ranging from about a month to around three months in the adult and then the limb becomes fully functional.

In spite of the historically small size of the number of researchers studying limb regeneration, remarkable progress has been made recently in establishing the axolotl (Ambystoma mexicanum) as a model genetic organism.

Regeneration of human skeleton

Finger Tips

Studies in the 1970s showed that children up to the age of 10 or so who lose fingertips in accidents can regrow the tip of the digit within a month provided their wounds are not sealed up with flaps of skin – the de facto treatment in such emergencies. They normally won't have a finger print, and if there is any piece of the finger nail left it will grow back as well, usually in a square shape rather than round.[6][7]

In August 2005, Lee Spievack, then in his early sixties, accidentally sliced off the tip of his right middle finger just above the first phalanx. His brother, Dr. Alan Spievack, was researching regeneration and provided him with powdered extracellular matrix, developed by Dr. Stephen Badylak of the McGowan Institute of Regenerative Medicine. Mr. Spievack covered the wound with the powder, and the tip of his finger re-grew in four weeks.[8] The news was released in 2007. Lee Spievack is the first documented case of an adult human regenerating fingertips;[6] however, Ben Goldacre has described this as "the missing finger that never was", claiming that fingertips regrow and quoted Simon Kay, professor of hand surgery at the University of Leeds, who from the picture provided by Goldacre described the case as seemingly "an ordinary fingertip injury with quite unremarkable healing" and as "junk science".[9]

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CBS News reports how your own stem cells can grow fingertips - and maybe whole limbs and repair organs.

They also talk in this video about spray on skin procedures. I actually had a similar procedure called 'ReCell' by Clinical Cell Culture (C3) on a scar burn from when I was little. ReCell is a Procedure that was developed by Dr Fiona Wood and was used on the bali bombing burns victims . The procedure was relatively new when I had the procedure 5 years ago and was mostly intended for putting the skin pigmentation back into the scar tissue. A small skin biopsy was taken of normal skin from my butt lol, & then put it into this little machine (see pic below) and the cells are multiplied , then basically the next part of the operation was scraping the top layer of the scar area until it bleeds to recreate a wound and spraying on the new skin cells back into the scar to make it look like normal skin when It heals. I was asleep during the process thank god ;). It improved the appearance somewhat but to be honest I was hoping for better results, but maybe these procedures have improved since then. Possibly the CellSpray Procedure would of been more beneficial, the cells are harvested in a lab & seems more intensive though whereas the ReCell Procedure the cells are created during the procedure. But there have been some good results when these treatments are applied to patients immediately after their accidents before allowing scars to form.

ReCell® is an innovative medical device for harvesting autologous skin cells. Developed as an 'off the shelf' kit, ReCell® enables a thin split thickness biopsy, taken at the time of the procedure, to be processed into an immediate cell population for delivery onto the wound surface.

more information

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Ribs

There have appeared claims that human ribs could regenerate if the periosteum, the membrane surrounding the rib, were left intact. In one study rib material was used for skull reconstruction and all 12 patients had complete regeneration of the resected rib.[10]

Regeneration of human liver

The human liver is one of the few glands in the body that has the ability to regenerate from as little as 25% of its tissue.[11] This is largely due to the unipotency of hepatocytes.[12] Resection of liver can induce the proliferation of the remained hepatocytes until the lost mass is restored, where the intensity of the liver’s response is directly proportional to the mass resected. For almost 80 years surgical resection of the liver in rodents has been a very useful model to the study of cell proliferation.[13][14]

Kidney regeneration

Regenerative capacity of the kidney remains largely unexplored. The basic functional and structural unit of the kidney is nephron, which is mainly composed of four components: the glomerulus, tubules, the collecting duct and peritubular capillaries. The regenerative capacity of the mammalian kidney is limited compared to that of lower vertebrates.

Regeneration in the mammalian kidney

In the mammalian kidney, the regeneration of the tubular component following an acute injury is well known. Recently regeneration of the glomerulus has also been documented. Following an acute injury, the proximal tubule is damaged more, and the injured epithelial cells slough off the basement membrane of the nephron. The surviving epithelial cells, however, undergo migration, dedifferentiation, proliferation, and redifferentiation to replenish the epithelial lining of the proximal tubule after injury. Recently, the presence and participation of kidney stem cells in the tubular regeneration has been shown. However, the concept of kidney stem cells is currently emerging. In addition to the surviving tubular epithelial cells and kidney stem cells, the bone marrow stem cells have also been shown to participate in regeneration of the proximal tubule, however, the mechanisms remain controversial. Recently, studies examining the capacity of bone marrow stem cells to differentiate into renal cells are emerging [15].

Regeneration in the lower vertebrate kidney

Like other organs, the kidney is also known to regenerate completely in lower vertebrates such as fish. Some of the known fish that show remarkable capacity of kidney regeneration are goldfish, skates, rays, and sharks. In these fish, the entire nephron regenerates following injury or partial removal of the kidney.

MORE ON REGENERATION FROM WIKIPEDIA

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And last a little video of my axolotls
(and Xena mistaking Sally's leg for food again!):


video

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