Category Archives: Stem Cell Videos

Constant shortage of donated corneas have led researchers in Sweden and Spain to explore the possibilities of cultivating corneas from human stem cells.

Two separate studies from the University of Navarra Hospital, Spain and Sahlgrenska Academy University of Gothenburg, Sweden, have attempted to cue in on developing the "epithelial cells" that keep the cornea in its transparent form.

While Swedish scientists have grown stem cells on human corneas, their Spanish counterparts have regenerated the corneal epithelium using cells from the healthy limbus of patients with corneal damage.

A corneal transplant is the only way to prevent total blindness. The result is that nearly 100,000 corneal implants are impacted globally each year. The process calls for replacing the damaged cornea with a healthy and transparent one, relying heavily on donors. Religious or political views have also attacked the medical outcomes of corneal implants adding to long waiting periods for donor-led corneal transplants.

Swedish Scientists Grow Cornea in the Laboratory

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In a first-time effort, scientists at the Sahlgrenska Academy have grown stem cells on human corneas which could perhaps do away with donated corneas in the long run.

The Swedish study published in the journal Acta Ophthalmologica explored ways to develop "epithelial cells" using laboratory cultures for 16 days, which were further cultured on the human cornea for another six days.

Lead scientists Charles Hanson and Ulf Stenevi used defective corneas from the ophthalmology clinic at Sahlgrenska University Hospital in Mlnda for their experiment.

"Similar experiments have been carried out on animals, but this is the first time that stem cells have been grown on damaged human corneas. It means that we have taken the first step towards being able to use stem cells to treat damaged corneas," said Hanson.

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Scientists Repair Eyesight Using Human Cornea From Stem Cells

Washington, Mar 6 : Researchers have for the first time successfully cultivated stem cells on human corneas, which may eliminate the need for donators in the long run.

The damaged and cloudy cornea that is turning the patient blind is replaced with a healthy, transparent one.

But the procedure requires a donated cornea, and there is a severe shortage of donated material. This is particularly the case throughout the world, where religious or political views often hinder the use of donated material.

Scientists at the Sahlgrenska Academy, University of Gothenburg, have taken the first step towards replacing donated corneas with corneas cultivated from stem cells.

Scientists Charles Hanson and Ulf Stenevi have used defective corneas obtained from the ophthalmology clinic at Sahlgrenska University Hospital in Molndal.

Their study shows how human stem cells can be caused to develop into what are known as 'epithelial cells'after 16 days' culture in the laboratory and a further 6 days' culture on a cornea. It is the epithelial cells that maintain the transparency of the cornea.

"Similar experiments have been carried out on animals, but this is the first time that stem cells have been grown on damaged human corneas. It means that we have taken the first step towards being able to use stem cells to treat damaged corneas," said Charles Hanson.

"If we can establish a routine method for this, the availability of material for patients who need a new cornea will be essentially unlimited. Both the surgical procedures and the aftercare will also become much more simple," said Ulf Stenevi.

The study has been published in the journal Acta Ophthalmologica. (ANI)

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Stem cells 'could repair damaged cornea'

27-02-2012 20:17 BY EMILY SPAIN You're watching multisource health/science news analysis from Newsy. Researchers might have a cure in the works for infertility in women. Scientists say they found ovary stem cells they can convert into unfertilized human eggs. WBAL has the details of the experiment. "Similar experiments in mice show transplanting the egg cells into the ovaries of infertile females produced healthy offspring. Scientists believe the same is possible in humans and are exploring the possibility of human stem cell banks." Researchers from Massachusetts General Hospital used a cell-sorting machine to find reproductive cells from the ovaries of mice and then did the same with donated human ovaries. According to the New York Times, the experiment on human ovaries had positive results. "The egg cells, when injected into mice, generated follicles, the ovarian structure in which eggs are formed, as well as mature eggs, some of which had a single set of chromosomes, a signature of eggs and sperm." The BBC talked to one doctor who called the results of the experiment "extremely significant" and "a potentially landmark piece of research." The outlet quoted him saying: "If this research is confirmed it may overturn one of the great asymmetries of reproductive biology - that a woman's reproductive pool of gametes may be renewable, just like a man's." Other researchers aren't so sure. Some question if egg-producing cells actually exist in ovaries. Director of the Center for Reproductive ...

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Stem Cells Make Human Eggs: Cure for Infertility? - Video

Study: 'Chemo brain' may not go away for cancer patients

Chemotherapy patients have long complained of the mental fog that tends to accompany treatment. Now, a new study suggests that certain combinations of chemo drugs may have long-term effects on cognition.

Researchers looked at 196 women who had been treated for early-stage breast cancer with a three-drug chemotherapy regimen. The women underwent cognition testing an average of 21 years after they had received chemo. They were compared with 1,509 healthy women who had never had cancer. The women in the study ranged in age from 50 to 80.

The women who had chemotherapy fared much worse than the control group on tests of verbal memory, cognitive processing speed, executive function, and psychomotor speed.

Previous studies suggested that "chemo brain" can persist for five years after treatment, but this study is the first to show possible permanent cognitive damage.

- Los Angeles Times

More Americans are turning to the emergency room for routine dental problems - a choice that often costs 10 times more than preventive care and offers far fewer treatment options than a dentist's office, according to an analysis of government data and dental research.

Most of those emergency visits involve trouble such as toothaches that could have been avoided with regular checkups but went untreated, in many cases because of a shortage of dentists, particularly those willing to treat Medicaid patients, the analysis said.

The number of E.R. visits nationwide for dental problems increased 16 percent from 2006 to 2009, and the report released Tuesday by the Pew Center on the States suggests the trend is continuing.

Emergency rooms generally can offer pain relief and medicine for infected gums but not much more for dental patients. And many patients are unable to find or afford follow-up treatment, so they end up back in the emergency room.

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Personal Health: Chemo brain, stem cells and more

Public release date: 5-Mar-2012 [ | E-mail | Share ]

Contact: Charles Hanson charles.hanson@obgyn.gu.se 46-313-423-572 University of Gothenburg

A new cornea may be the only way to prevent a patient going blind but there is a shortage of donated corneas and the queue for transplantation is long. Scientists at the Sahlgrenska Academy at the University of Gothenburg, Sweden, have for the first time successfully cultivated stem cells on human corneas, which may in the long term remove the need for donators.

Approximately 500 corneal transplantations are carried out each year in Sweden, and about 100,000 in the world. The damaged and cloudy cornea that is turning the patient blind is replaced with a healthy, transparent one. But the procedure requires a donated cornea, and there is a severe shortage of donated material. This is particularly the case throughout the world, where religious or political views often hinder the use of donated material.

Replacing donated corneas

Scientists at the Sahlgrenska Academy, University of Gothenburg, have taken the first step towards replacing donated corneas with corneas cultivated from stem cells. Scientists Charles Hanson and Ulf Stenevi have used defective corneas obtained from the ophthalmology clinic at Sahlgrenska University Hospital in Mlndal. Their study is now published in the journal Acta Ophthalmologica, and shows how human stem cells can be caused to develop into what are known as "epithelial cells" after 16 days' culture in the laboratory and a further 6 days' culture on a cornea. It is the epithelial cells that maintain the transparency of the cornea.

First time ever on human corneas

"Similar experiments have been carried out on animals, but this is the first time that stem cells have been grown on damaged human corneas. It means that we have taken the first step towards being able to use stem cells to treat damaged corneas", says Charles Hanson. "If we can establish a routine method for this, the availability of material for patients who need a new cornea will be essentially unlimited. Both the surgical procedures and the aftercare will also become much more simple", says Ulf Stenevi.

Few clinics conduct transplants

Only a few clinics are currently able to transplant corneas. Many of the transplantations in Sweden are carried out at the ophthalmology clinic at Sahlgrenska University Hospital, Department of Ophthalmology, Mlndal.

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Stem cells can repair a damaged cornea

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Producing More Stem Cells! (Brainstorm Ep51) - Video

An experiment that has produced human eggs from stem cells could be a boon for women desperate to have a baby, scientists claim.

New research has swept away the belief women only have a limited stock of eggs and replaces it with the theory the supply is continuously replenished from precursor cells in the ovary.

'The prevailing dogma in our field for the better part of the last 50 or 60 years was that young girls at birth were given a bank account of eggs at birth that's not renewable,' says Jonathan Tilly, director of the Vincent Center for Reproductive Biology at Massachusetts General Hospital, who led the research.

'As they become mature and become a woman, they use those eggs up (and) the ovaries will fail when they enter menopause.'

Tilly first challenged the 'bank account' doctrine eight years ago, suggesting female mammals continue producing egg-making cells into adulthood rather than from a stock acquired at birth.

His theory ran into a firestorm.

Other scientists challenged the accuracy of his experiments or dismissed their conclusions as worthless, given they were only conducted on lab mice.

But Tilly says the new work not only confirms his controversial idea, it takes it further.

In it, his team isolated egg-producing stem cells in human ovaries and then coaxed them into developing oocytes, as eggs are called.

Building on a feat by Chinese scientists, they pinpointed the oocyte stem cells by using antibodies which latched onto a protein 'handle' located on the side of these cells.

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Human eggs produced from stem cells

27-02-2012 14:16 There may be new hope for those trying to overcome infertility. Convential wisdom from the past fifty or so years holds that women are born with a finite number of egg cells for reproduction. But a newly released report suggests that rare stem cells discovered in the ovaries of young women may be key to producing new eggs. Jonathan Tilly of Harvard's Massachusetts General Hospital, led a team that used a protein to gather stem cells from healthy human ovaries donated by young Japanese women. The researchers then injected those stem cells into pieces of human ovary, and new egg cells formed within two weeks. While there's no guarantee the cells will mature into usable, quality eggs, the findings could lead to better treatments for women left infertile because of disease or age. According to Tilly, "Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs."

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: Stem Cells May Offer Fertility Hope by Helping Generate New Eggs - Video

ScienceDaily (Mar. 1, 2012) Despite the promise associated with the therapeutic use of human stem cells, a complete understanding of the mechanisms that control the fundamental question of whether a stem cell becomes a specific cell type within the body or remains a stem cell has-until now-eluded scientists.

A University of Georgia study published in the March 2 edition of the journal Cell Stem Cell, however, creates the first ever blueprint of how stem cells are wired to respond to the external signaling molecules to which they are constantly exposed. The finding, which reconciles years of conflicting results from labs across the world, gives scientists the ability to precisely control the development, or differentiation, of stem cells into specific cell types.

"We can use the information from this study as an instruction book to control the behavior of stem cells," said lead author Stephen Dalton, Georgia Research Alliance Eminent Scholar of Molecular Biology and professor of cellular biology in the UGA Franklin College of Arts and Sciences. "We'll be able to allow them to differentiate into therapeutic cell types much more efficiently and in a far more controlled manner."

The previous paradigm held that individual signaling molecules acted alone to set off a linear chain of events that control the fate of cells. Dalton's study, on the other hand, reveals that a complex interplay of several molecules controls the "switch" that determines whether a stem cell stays in its undifferentiated state or goes on to become a specific cell type, such as a heart, brain or pancreatic cell.

"This work addresses one of the biggest challenges in stem cell research-figuring out how to direct a stem cell toward becoming a specific cell type," said Marion Zatz, who oversees stem cell biology grants at the National Institutes of Health's National Institute of General Medical Sciences, which partially supported the work.

"In this paper, Dr. Dalton puts together several pieces of the puzzle and offers a model for understanding how multiple signaling pathways coordinate to steer a stem cell toward differentiating into a particular type of cell. This framework ultimately should not only advance a fundamental understanding of embryonic development, but facilitate the use of stem cells in regenerative medicine."

To get a sense of how murky the understanding of stem cell differentiation was, consider that previous studies reached opposite conclusions about the role of a common signaling molecule known as Wnt. About half the published studies found that Wnt kept a molecular switch in an "off" position, which kept the stem cell in its undifferentiated, or pluripotent, state. The other half reached the opposite conclusion.

Could the same Wnt molecule be responsible for both outcomes? As it turns out, the answer is yes. Dalton's team found that in small amounts, Wnt signaling keeps the stem cell in its pluripotent state. In larger quantities, it does the opposite and encourages the cell to differentiate.

But Wnt doesn't work alone. Other molecules, such as insulin-like growth factor (Igf), fibroblast growth factor (Fgf2) and Activin A also play a role. To complicate things further, these signaling molecules amplify each other so that a two-fold increase in one can result in a 10-fold increase in another. The timing with which the signals are introduced matters, too.

"One of the things that surprised us was how all of the pathways 'talk' to each other," Dalton said. "You can't do anything to the Igf pathway without affecting the Fgf2 pathway, and you can't do anything to Fgf2 without affecting Wnt. It's like a house of cards; everything is totally interconnected."

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Basic molecular 'wiring' of stem cells revealed

Public release date: 2-Mar-2012 [ | E-mail | Share ]

Contact: Klaus Hansen klaus.hansen@bric.ku.dk (45) 21-15-55-64 University of Copenhagen

Upon fertilisation, a single cell is formed when egg and sperm fuse. Our entire body, with more than 200 specialised cell types and billions of cells are formed from this single cell. It is a scientific mystery how the early stem cells know what cell type to become, but a precise timing of the process is crucial for correct development and function of our body. Researchers across the world chase knowledge about our stem cells, as this knowledge holds great promises for development of treatment against several major diseases. Researchers from BRIC, University of Copenhagen, have just shown that the molecule REST acts as an adapter in stem cells, coupling molecular on-off switches with neural genes and thereby times neuronal development.

"REST secure neuronal genes to be turned off in our stem cells until the correct time point in fetal life, where the molecule is lost and development of the nervous system begins. Our results are very important for the understanding of how genes are turned on and off during fetal development, but also relates to disease development such as cancer. Hopefully, our future studies of REST will contribute to the development of new types of treatments," says Associate Professor and Group Leader at BRIC, Klaus Hansen.

Genetic switches

All our cells contain the same DNA, yet they can develop into specialised cells with different shapes and functions. This ability is due to only selective genes being turned on in for example neuronal cells and other genes in liver cells and skin cells. Postdoc Nikolaj Dietrich from Klaus Hansen's laboratory has been the main driver of the investigation:

"Our results show that REST act as an adapter for the protein complexes called PRCs, connecting these complexes to neuronal genes. The PRCs are genetic switches turning off genes and therefore REST and the PRCs act in concert to shutdown neuronal genes. A similar mechanism has previously been described in fruit flies, but until now, no one has been able to identify such adapter-molecules in humans or other mammals. This has led to various biological hypotheses, but now we are able to show that this genetic mechanism has been conserved trough out evolution," says Nikolaj Dietrich.

Brain damage and brain tumors

REST and PRC are attached to neuronal genes in the early fetal stem cells, keeping neuronal genes turned off. During fetal development, REST disappears in cells that are determined to develop into neuronal cells, whereas the molecule is preserved in other cell types. REST is also preserved in special neuronal stem cells, ensuring that these cells maintain their stem cell properties. This is crucial if we experience damage to our nervous system later in life, as only the neuronal stem cells can repair the damage by giving rise to new neurons and thereby secure vital body functions. However, REST also appears to be associated with a higher risk of cancer:

"An increased amount of REST has been found in the brain tumor form called neuroblastoma. Some of our results indicate that REST may be involved in cancer, as the molecule can turn off some growth-inhibitory and cancer-protective genes called tumor suppressors. This possible action of REST is the focus of ongoing studies," says Nikolaj Dietrich.

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'REST' is crucial for the timing of brain development