Courtesy EkemLast week we learned that scientists cloned human embryos using adult skin and fertile eggs from a woman donor. Now the Human Fertilization and Embryology Authority in Britain has approved creating human embryos using eggs from animals like cows or rabbits. Because the animal cell's nucleus would be removed before human DNA was added, scientists said the resulting egg would not be a chimera.
"Cow eggs seem to be every bit as good at doing this job as human eggs," said Lyle Armstrong of Newcastle University.
"We will only use them as a scientific tool and we need not worry about cells being derived from them ever being used to treat human diseases," Armstrong said.
Animal eggs are abundant and easily obtained. Researchers hope to refine their techniques by practicing first on animal eggs to producing human stem cells. Human stem cells, which have the ability to develop into any cell in the human body, show promise for understanding and healing many human ailments. The embryos would not be allowed to develop for more than two weeks.
Courtesy Thomas Matthiesen, University of Minnesota
Did you know that nearly 5 million people live with heart failure? More surprisingly, approximately 50,000 United States patients die annually waiting for a donor heart.
University of Minnesota researchers recently announced they have created a beating heart in the laboratory. It sounds like science fiction, but it is a real medical breakthrough. The researchers removed the tissue from a dead rat heart and replaced it with living cells from newborn rats. With the help of electrical signals, the entire heart began to beat.
The researchers used a detergent to remove the cells from the rat hearts. This left behind only the nonliving fibers that give the heart its shape. The result was a white, rubbery, 3-D “skeleton”. This structure, called the extracellular matrix, allows cells to attach and grow into tissue, and gives the heart muscle something to pull against. The researchers injected cells from newborn rats into the left ventricle and pumped oxygen and nutrients through the structure of blood vessels. They helped the process by sending electrical signals through the new tissue. In eight days, the hearts were pumping – some continued beating for 40 days.
The supply of donor organs is limited and the risks for infection or rejection of the transplanted organ can be high. If the technique is perfected, doctors may be able to use patients’ own stem cells to recellularize a donor heart.
The next steps
The University of Minnesota research team has successfully decellularized pig hearts, and hopes that other types of organs can be created in the future.
A paper published in the online journal, Stem Cells, yesterday titled "Development of Human cloned Blastocysts Following Somatic Cell Nuclear Transfer (SCNT) with Adult Fibroblasts" is the first documented demonstration that ordinary cells from an adult human can be used to make cloned embryos mature enough to produce stem cells
"A research team at Stemagen, a biotech company based in San Diego, California, started with skin cells donated by two men and 25 eggs, or oocytes, donated by women at a nearby fertility center. The scientists removed the DNA-containing nuclei from the eggs and replaced them with DNA from the donor skin cells. Two of the eggs became 5-day-old embryos, or blastocysts, that were clones of the male donors."Science
The next big step will be to create a human embryonic stem cell line from cloned embryos. Stem cells from cloned embryos could provide a valuable tool for studying diseases, screening drugs, and creating transplant material to treat conditions like diabetes and Parkinson's disease.
As expected, critics are raising objections. This procedure requires cutting healthy eggs out of women, then altering them to produce living embryos, which are then destroyed. Should this be allowed?
Tissue engineering has allowed a dead rat heart to be stripped of its cellular material, then after injecting the remaining scaffold material with with new cardiac cells, the cells organized themselves until the heart became alive.
A "crazy idea" at the University of Minnesota that could not get federal funding yielded "unbelievable" results after getting funding from the University of Minnesota and from the Medtronic Research Foundation.
The accomplishment gave a significant boost to medicine’s dream of growing human organs to replace damaged ones. Organ transplants usually require replacement organs that fulfill extreme compatibility issues. By using the patients own cells in the rebuilt organs scientists hope to eliminate the need for patients to take anti-rejection drugs for the rest of their lives.
The next step will be to use these techniques on pig hearts. Pig hearts are similar enough to a humans that parts from them have already been used in humans.
"Although this is only a first step requiring considerable follow-up development, the study nevertheless represents an exciting breakthrough that will eventually make the prospect of repairing damaged hearts a reality and will also be an approach that can be extended to other organs." Dr Jon Frampton Wellcome Trust Senior Fellow at the University of Birmingham
New York Times
Nature Medicine journal's Perfusion-decellularized matrix: using nature's platform to engineer a bioartificial heart (abstract)
Courtesy Pat RyanIn Great Britain it's been discovered that twins, who had been separated at birth and raised in different families somehow met in later life and married each other without knowing they were brother and sister.
The bizarre story has raised concerns of the importance of adopted children being able to find out information about their biological families.
The identity of the two people involved is being kept secret, and since the discovery their marriage has been annulled. But efforts are underway to insure that something similar doesn't happen again.
Each sibling said they felt a strong attraction to the other, something that has been seen in other separated sibling cases.
"We have a resistance, a very strong incest taboo where we are aware that someone is a biological relative," said Pam Hodgkins, of the charity Adults Affected by Adoption. "But when we are unaware of that relationship, we are naturally drawn to people who are quite similar to ourselves. And of course there is unlikely to be anyone more similar to any individual than their sibling."
Courtesy johnmukA few years back scientists in Taiwan announced that they had genetically altered three cloned pigs so that they glowed fluorescent green. The feat was accomplished by injecting porcine embryos with fluorescent green protein from jellyfish.
Pigs are often used in studying human diseases.
In the Taiwanese experiment, the altered pigs’ internal organs glowed green throughout under ultraviolet light. On the outside they emitted a light green tint, particularly around their knuckles, eyes, and snout.
This week Chinese scientists announced that one of the altered pigs has successfully passed on its glow genes to some of its progeny. Two of 11 piglets born are displaying the same glowing traits their genetically engineered mother had been given in the lab. What this proves is that the sow remained fertile despite the engineering, and was able to pass on the altered gene.
The researchers hope the process will be useful in stem cell research and the monitoring of healing tissue during human transplants and other such procedures.
At last report, the mother pig was doing fine and glowing with pride.
Courtesy AMNHNo, this isn't about making your skin brontosaurus smooth or how to remove the million year-old age spots you've noticed cropping up on the back of your hands. This is about the secrets revealed in the remains of a 100 million year-old plant-eating dinosaur that are providing new information about the anatomy of the prehistoric beasts.
The Psittacosaurus (“parrot lizard”) fossil was dug up in China by paleontologists from England and South Africa. Besides the usual bones, some of the beaked dinosaur’s skin was preserved as well, providing a rare glimpse into its skin structure.
The outer covering of the bipedal herbivore seems to have been torn open by a predator or scavenger, leaving its skin folded back to reveal a cross-section of it. Tooth marks found on the fossil add weight to that theory.
The preservation of skin and other soft tissue is a rare occurrence in the fossil record. But sometimes, unusual burial conditions can result in some uncommon and very remarkable fossils.
In the Psittacosaur’s case, the folded back skin exhibits more than 25 layers of collagen, suggesting it to be of a rugged variety like that of sharks or reptiles today. A tough hide would have been an asset against the daily rigors the Psittacosaurus no doubt faced during its lifetime in the Early Cretaceous.
The scientists also wonder if the thick skin may not have been further protected with feather or scales. Of course, all you need is a bottle of Skin-so-soft or some Vaseline.
Story on BBC.com
Cut spinal cords, destroyed brain tissue, or damaged heart muscle can be repaired by injecting stem cells into the damaged area. Embryonic stem (ES) cells are like blank cells that give rise to every type of cell and tissue in the body. Using human embryos or unfertilized human eggs as a source of stem cells raised show-stopping opposition. Now stem cells have been produced from skin.
Two separate teams of researchers announced on Tuesday they had transformed ordinary skin cells into batches of cells that look and act like embryonic stem cells -- but without using cloning technology and without making embryos.
Both teams call the new cells induced pluripotent stem (iPS) cells and say they look and act like embryonic stem cells.
The research was published online Tuesday by two journals, Cell and Science. The Cell paper is from a team led by Dr. Shinya Yamanaka of Kyoto University; the team published by Science was led by Junying Yu, working in the lab of stem-cell pioneer James Thomson of the University of Wisconsin-Madison.
Thompson said the technique is so simple that "thousands of labs in the United States can do this, basically tomorrow." In contrast, the cloning approach is so complex and expensive that many scientists say it couldn't be used routinely to supply stem cells for therapy.
where do mysteries end finally?
:are cells made up of any thing smaller?
Clam diggers in Iceland recently pulled up a specimen that proved to be the oldest living animal on Earth. Or, more accurately, had been—the clam is now deceased.
Scientists at Bangor University in Wales counted the age rings on the clam and estimate it to have been up to 410 years old. That’s almost 200 years older than the previous record-holder.
Born in 1607, the clam was a contemporary of Shakespeare, although there is no evidence the two ever met. Researchers nicknamed the clam “Ming,” in honor of the Chinese dynasty that was in power when the clam was born.
Old specimens like this help scientists reconstruct the Earth’s past. Growth rings will be thick or narrow, depending on factors such as water temperature and food supply. Chris Richardson, a professor at the University, compared the growth rings to a tape recorder, faithfully recording environmental conditions.
The clam might also shed light on the science of aging. Scientists theorize that animals that live to extremely old ages have cells that function in ways different from our own. Understanding those differences could help medicine combat the effects of aging in humans.