Category Archives: Stem Cells

Scientists studying an aggressive form of leukaemia have discovered that rather than displacing healthy stem cells in the bone marrow as previously believed, the cancer is putting them to sleep to prevent them forming new blood cells.

The finding offers the potential that these stem cells could somehow be turned back on, offering a new form of treatment for the condition, called Acute Myeloid Leukaemia (AML). The work was led by scientists at Queen Mary, University of London with the support of Cancer Research UK's London Research Institute.

Around 2,500 people are diagnosed with AML in the UK each year, both young and old. Although AML is curable in some the majority die from this disease.

Normally, the bone marrow produces haematopoietic stem cells which mature into "adult" blood cells. In people with AML the bone marrow is invaded by leukaemic myeloid cells which aren't able to develop into normal functioning blood cells.

The result is that the body does not have enough red blood cells or platelet cells, which can cause symptoms of anaemia, such as tiredness, and increase the risk of excessive bleeding. Patients are also more vulnerable to infection as the white blood cells, which fight bacteria and viruses, are not properly formed.

Dr David Taussig, from the Barts Cancer Institute at Queen Mary, University of London, who led the research, said: "The widely accepted explanation has held that AML causes bone marrow failure by depleting the bone marrow of normal haematopoietic stem cells by killing or displacing them.

"However, we have found that samples of bone marrow in both mice models and patients with AML contain the same, or more, of these normal stem cells than usual. So the cancer isn't getting rid of them, instead it appears to be turning them off so they aren't going on to form healthy blood cells.

"If we can find out how the cancer cells are doing this, we can look at exploiting it to find ways to wake these stem cells up. This is very important as, while the cure rate for younger patients can be around 40 per cent, in older patients it is much lower. The treatments we have, such as chemotherapy and bone marrow transplants, just aren't very successful in this older patient group."

The scientists studied the levels of haematopoietic stem cells (HSC) in the bone marrow of mice transplanted with human AML. They found the numbers of normal mouse HSCs stayed the same, however what did change was that the HSCs were no longer going through the stages of development which finally results in the formation of new blood cells.

The findings were confirmed by the analysis of bone marrow from 16 patients with AML.

Read the original:
Could sleeping stem cells hold key to treatment of aggressive blood cancer?

The artificial burger will be cooked and served for the first time this week It cost in the region of 250,000 to produce the prototype The 5oz beef burger is grown from the stem cells of one cow Creator Professor Mark Post believes the development could help solve problems in the meat industry

By Jaymi Mccann and Sophie Borland

PUBLISHED: 04:44 EST, 28 July 2013 | UPDATED: 18:38 EST, 28 July 2013

687 shares

232

View comments

The worlds first test-tube burger will be served in London next week. It is made from meat grown in a laboratory, rather than cattle raised in pastures.

And its developers hope it will show how the soaring global demand for protein can be met without the need for vast herds of cattle.

The 5oz Frankenburger, which cost 250,000 to produce, is made from 3,000 tiny strips of meat grown from the stem cells of a cow.

The raw meat is said to be grey with a slippery texture similar to squid or scallop.

See the original post:
Hamburger made of test tube-grown beef from stem cells of slaughtered cow to be cooked and eaten this week

Washington, July 28 (ANI): Researchers transplanted derived functional hepatocytes from human stem cells into mice suffering from acute liver injury, and found that these liver cells functioned normally and raised survival of the treated animals.

Massoud Vosough and co-authors demonstrate a large-scale, integrated manufacturing strategy for generating functional hepatocytes in a single suspension culture grown in a scalable stirred bioreactor.

In the article 'Generation of Functional Hepatocyte-Like Cells from Human Pluripotent Stem Cells in a Scalable Suspension Culture' the authors describe the method used for scale-up, differentiation of the pluripotent stem cells into liver cells, and characterization and purification of the hepatocytes based on their physiological properties and the expression of liver cell biomarkers.

David C. Hay, MRC Centre for Regenerative Medicine, University of Edinburgh, U.K., comments on the importance of Vosough et al.'s contribution to the scientific literature in his editorial in Stem Cells and Development entitled 'Rapid and Scalable Human Stem Cell Differentiation: Now in 3D.'

The researchers 'developed a system for mass manufacture of stem cell derived hepatocytes in numbers that would be useful for clinical application,' creating possibilities for future 'immune matched cell based therapies,' Hays said.

Such approaches could be used to correct mutated genes in stem cell populations prior to differentiation and transplantation, he adds.

The findings have been published in Stem Cells and Development. (ANI)

Read more here:
Human stem cells help regenerate liver function in mice

Stem cells

Arthur Caplan, Ph.D NBC News contributor

5 hours ago

What should we think when a scientist claims to have found a cell in the human body with miraculous powers that no one before has ever seen and almost no one else can even find trying to follow his directions of where to look?

The small number of scientific proponents of the miraculous healing powers of a controversial form of stem cells called VSELSvery small embryonic-like stem cells -- are facing this very question. The usual answer is that, at best, the claim must be the product of wishful thinking, or at worst, fraud.

A just published study by the distinguished stem cell biologist Irving Weissman of Stanford Universitys School of Medicine says he and his team could not find VSELS or corroborate their alleged regenerative power. The Catholic Church, because of its opposition to embryo destruction to obtain stem cells for research, gave its blessings and money to VSELS therapy so it also now finds itself up to its miters in controversy.

A few years ago in early November 2011, I was lucky enough to be asked to attend a meeting on stem cell research at the Vatican. Key officials there had decided that worldwide battles over the ethics of using of embryonic stem cells merited a gathering of scientists and prominent Catholic theologians. To no ones surprise including mine, the meeting was designed as a celebration of the power of adult stem cellsnaturally occurring cells in your body that can regenerate damaged tissue or grow new cells including bone marrow, hair follicle cells and the lining of the gut and liver cells. The Vatican wanted these and only these kinds of cells to be used to cure now intractable diseases such as spinal cord injury, diabetes and heart disease. Those doctors and scientists who favored studying cells taken from human embryos, which meant their destruction, which also can regenerate many different kinds of cells, got little airtime and no ethical traction.

One of the strangest moments at the conference came when Polish-born researcher Mariusz Z. Ratajczak, now on the faculty at the University of Louisville, stood up and told the enthralled bishops, priests, monsignors, cardinals, theologians and the few other odd ducks like me that he had found very tiny cells residing in adult cells that behaved just like embryos. Ratajczak said they could develop into all manner of other cells, thereby acting as natural repair kits, given the right conditions and genetic tweaking.

The theologians were delighted. They were so excited that they took the unprecedented step of investing the churchs money in a company, Neostem, to help develop Ratajczaks discovery. His VSELS would provide an ethical way to use stem cells to cure disease while getting the Church out of a horrible bindcondemning embryo destruction for obtaining stem cells while so many worldwide suffered premature death and serious disability.

Weissman thinks VSELS are nothing more than cell debris and fragments from dying cells. He does not believe "that VSELs have the potentials claimed, he wrote in the study, and doubts that these cells have potential for clinical application in humans. Weissman study is now the fourth to fail to find the miracle VSELS or to be able to show any evidence of their regenerative healing power.

Read this article:
Bioethicist: Failed search for controversial form of stem cells shows danger of mixing science, religion