http://www.genengnews.com/news/bnitem.aspx?name=47611410
EUREKALERT
Contact: Andrew Baird
Andrew.Baird@jcu.edu.au
61-040-028-9770
ARC Centre of Excellence in Coral Reef Studies
Claims that coastal tree barriers can halt the might of a tsunami are false and dangerous, a team of international marine scientists said today.
There are many reasons for preserving the world's dwindling stocks of mangroves, but protecting people from tsunamis is not one of them, they say.
On the eve of the anniversary of the devastating 2004 Boxing Day Tsunami, which claimed nearly a quarter of a million lives around the eastern Indian Ocean, researchers have issued a strong warning against coastal communities and governments putting their trust in mangrove and tree barriers erected as a means of protection from earthquake-driven tidal waves.
"Following the Boxing Day Tsunami scientific studies were released which claimed that the damage to coastal communities had been less in places where there was a barrier of trees or coastal vegetation," explains Dr Andrew Baird of the ARC Centre of Excellence for Coral Reef Studies and James Cook University.
"As a result there has been a lot of tree planting in coastal areas affected by the tsunami, in the hope it will protect coastal communities in future from such events.
"However these studies looked only at the presence or absence of vegetation and the extent of damage and did not take account of other important variables, like the distance of a village from the shore, the height of the village above sea level or the shape of the seabed in concentrating the tsunami's power."
The study by Dr Alexander Kerr of the University of Guam, Dr Baird, Ravi Bhalla and V. Srinivas of the Foundation for Ecological Research, Advocacy and Learning India concludes there is, as yet, no evidence that coastal tree belts can provide meaningful protection against a tsunami or, for that matter storm surges produced by cyclones, such as the surge that followed Cyclone Nargis in Myanmar early this year which killed over 150,000 people.
As a result it would be extremely dangerous to rely on tree planting alone to shield coastal communities in the event of future tsunami or storm surges, they warn and doing so could lead to further tragedies.
The team's analysis of the pattern of damage of the Boxing Day 2004 tsunami shows that many variables were at work in determining how the force of the water affected people and structures on land, and these all need to be taken into account not just a few of them.
The findings have major implications for civil defence and emergency planning, the cost of restoring affected regions and in minimizing the death and destruction suffered by some of the poorest communities in the world, the team says.
"The idea that planting 'green belts' can both protect coastal communities and enhance their environment has been widely accepted," Dr Baird explains. "As a result a number of governments, aid agencies and scientists have been promoting it enthusiastically.
"However this could place the communities shielded in this way at future risk. Mangroves should be protected for their conservation value, and for the goods and services they provide to people even if they don't protect coastal dwellers from extreme events."
"In my own visits to the tsunami-ravaged areas, I saw places where quite heavy vegetation had provided absolutely no protection at all against the force of the ocean, and this led us to investigate the assumption more deeply. It turns out it was not well founded."
To fully explore what drives the flooding following tsunami like the Boxing Day Tsunami, and storm surges, like those that could accompany any of the many cyclones that hit northern Australia each year, an extensive, statistically-sound analysis needs to be carried out of all the factors which may act on the force of the waves driving inland.
These include the height of the settlement above the sea, its distance, the shape of the sea bottom and local land uses. These make the difficulty of accurately predicting tsunami damage much harder and a problem requiring rigorous analysis for multiple factors and their interaction.
In the meantime, there is much that can be done to limit the loss of life in future tsunami, in particular, early warning systems need to be installed, the population must be educated to recognise the signs of an imminent tsunami and evacuation plans need to put in place and practised. All these preparations are current in Japan, and should serve as an example to the rest of the world.
Their research report Roles of coastal bio-shields and their putative role in protecting coasts from large weather related disturbance events is soon to be published by the United Nations Environment Program.
Saturday, December 27, 2008
Trees won't stop tsunamis, scientists warn
Wednesday, November 19, 2008
Stem cell
http://en.wikipedia.org/wiki/Stem_cell
Stem cell
From Wikipedia, the free encyclopedia
Mouse embryonic stem cells with fluorescent marker.
Human Embryonic Stem cell colony on mouse embryonic fibroblast feeder layer.Stem cells are cells found in most, if not all, multi-cellular organisms. They are characterized by the ability to renew themselves through mitotic cell division and differentiating into a diverse range of specialized cell types. Research in the stem cell field grew out of findings by Canadian scientists Ernest A. McCulloch and James E. Till in the 1960s.[1][2] The two broad types of mammalian stem cells are: embryonic stem cells that are found in blastocysts, and adult stem cells that are found in adult tissues. In a developing embryo, stem cells can differentiate into all of the specialized embryonic tissues. In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing specialized cells, but also maintain the normal turnover of regenerative organs, such as blood, skin or intestinal tissues.
As stem cells can now be grown and transformed into specialized cells with characteristics consistent with cells of various tissues such as muscles or nerves through cell culture, their use in medical therapies has been proposed. In particular, embryonic cell lines, autologous embryonic stem cells generated through therapeutic cloning, and highly plastic adult stem cells from the umbilical cord blood or bone marrow are touted as promising candidates.[3]
Contents [hide]
1 Properties of stem cells
1.1 Potency definitions
1.2 Identifying stem cells
2 Embryonic stem cells
3 Adult stem cells
4 Lineage
5 Treatments
6 Controversy surrounding human embryonic stem cell research
7 Key stem cell research events
8 Stem cell funding & policy debate in the US
9 See also
10 References
11 External links
Properties of stem cells
The classical definition of a stem cell requires that it possess two properties:
Self-renewal - the ability to go through numerous cycles of cell division while maintaining the undifferentiated state.
Potency - the capacity to differentiate into specialized cell types. In the strictest sense, this requires stem cells to be either totipotent or pluripotent - to be able to give rise to any mature cell type, although multipotent or unipotent progenitor cells are sometimes referred to as stem cells.
Potency definitions
Pluripotent, embryonic stem cells originate as inner mass cells within a blastocyst. The stem cells can become any tissue in the body, excluding a placenta. Only the morula's cells are totipotent, able to become all tissues and a placenta.Potency specifies the differentiation potential (the potential to differentiate into different cell types) of the stem cell.
Totipotent stem cells are produced from the fusion of an egg and sperm cell. Cells produced by the first few divisions of the fertilized egg are also totipotent. These cells can differentiate into embryonic and extraembryonic cell types.
Pluripotent stem cells are the descendants of totipotent cells and can differentiate into cells derived from any of the three germ layers.
Multipotent stem cells can produce only cells of a closely related family of cells (e.g. hematopoietic stem cells differentiate into red blood cells, white blood cells, platelets, etc.).
Unipotent cells can produce only one cell type, but have the property of self-renewal which distinguishes them from non-stem cells (e.g. muscle stem cells).
Identifying stem cells
The practical definition of a stem cell is the functional definition - the ability to regenerate tissue over a lifetime. For example, the gold standard test for a bone marrow or hematopoietic stem cell (HSC) is the ability to transplant one cell and save an individual without HSCs. In this case, a stem cell must be able to produce new blood cells and immune cells over a long term, demonstrating potency. It should also be possible to isolate stem cells from the transplanted individual, which can themselves be transplanted into another individual without HSCs, demonstrating that the stem cell was able to self-renew.
Properties of stem cells can be illustrated in vitro, using methods such as clonogenic assays, where single cells are characterized by their ability to differentiate and self-renew.[4][5] As well, stem cells can be isolated based on a distinctive set of cell surface markers. However, in vitro culture conditions can alter the behavior of cells, making it unclear whether the cells will behave in a similar manner in vivo. Considerable debate exists whether some proposed adult cell populations are truly stem cells.
Embryonic stem cells
Main article: Embryonic stem cell
Embryonic stem cell lines (ES cell lines) are cultures of cells derived from the epiblast tissue of the inner cell mass (ICM) of a blastocyst or earlier morula stage embryos.[6] A blastocyst is an early stage embryo—approximately four to five days old in humans and consisting of 50–150 cells. ES cells are pluripotent and give rise during development to all derivatives of the three primary germ layers: ectoderm, endoderm and mesoderm. In other words, they can develop into each of the more than 200 cell types of the adult body when given sufficient and necessary stimulation for a specific cell type. They do not contribute to the extra-embryonic membranes or the placenta.
Nearly all research to date has taken place using mouse embryonic stem cells (mES) or human embryonic stem cells (hES). Both have the essential stem cell characteristics, yet they require very different environments in order to maintain an undifferentiated state. Mouse ES cells are grown on a layer of gelatin and require the presence of Leukemia Inhibitory Factor (LIF).[7] Human ES cells are grown on a feeder layer of mouse embryonic fibroblasts (MEFs) and require the presence of basic Fibroblast Growth Factor (bFGF or FGF-2).[8] Without optimal culture conditions or genetic manipulation,[9] embryonic stem cells will rapidly differentiate.
A human embryonic stem cell is also defined by the presence of several transcription factors and cell surface proteins. The transcription factors Oct-4, Nanog, and SOX2 form the core regulatory network that ensures the suppression of genes that lead to differentiation and the maintenance of pluripotency.[10] The cell surface antigens most commonly used to identify hES cells are the glycolipids SSEA3 and SSEA4 and the keratan sulfate antigens Tra-1-60 and Tra-1-81. The molecular definition of a stem cell includes many more proteins and continues to be a topic of research.[11]
After nearly ten years of research[12], there are no approved treatments or human trials using embryonic stem cells. ES cells, being pluripotent cells, require specific signals for correct differentiation - if injected directly into another body, ES cells will differentiate into many different types of cells, causing a teratoma. Differentiating ES cells into usable cells while avoiding transplant rejection are just a few of the hurdles that embryonic stem cell researchers still face.[13] Many nations currently have moratoria on either ES cell research or the production of new ES cell lines. Because of their combined abilities of unlimited expansion and pluripotency, embryonic stem cells remain a theoretically potential source for regenerative medicine and tissue replacement after injury or disease.
Adult stem cells
Main article: Adult stem cell
Stem cell division and differentiation. A - stem cell; B - progenitor cell; C - differentiated cell; 1 - symmetric stem cell division; 2 - asymmetric stem cell division; 3 - progenitor division; 4 - terminal differentiationThe term adult stem cell refers to any cell which is found in a developed organism that has two properties: the ability to divide and create another cell like itself and also divide and create a cell more differentiated than itself. Also known as somatic (from Greek Σωματικóς, "of the body") stem cells and germline (giving rise to gametes) stem cells, they can be found in children, as well as adults.[14]
Pluripotent adult stem cells are rare and generally small in number but can be found in a number of tissues including umbilical cord blood.[15] A great deal of adult stem cell research has focused on clarifying their capacity to divide or self-renew indefinitely and their differentiation potential.[16] In mice, pluripotent stem cells are directly generated from adult fibroblast cultures. Unfortunately, many mice don't live long with stem cell organs [17]
Most adult stem cells are lineage-restricted (multipotent) and are generally referred to by their tissue origin (mesenchymal stem cell, adipose-derived stem cell, endothelial stem cell, etc.).[18][19]
Adult stem cell treatments have been successfully used for many years to treat leukemia and related bone/blood cancers through bone marrow transplants.[20] Adult stem cells are also used in veterinary medicine to treat tendon and ligament injuries in horses.[21] The use of adult stem cells in research and therapy is not as controversial as embryonic stem cells, because the production of adult stem cells does not require the destruction of an embryo. Additionally, because in some instances adult stem cells can be obtained from the intended recipient, (an autograft) the risk of rejection is essentially non-existent in these situations. Consequently, more US government funding is being provided for adult stem cell research.[22]
Lineage
Main article: Stem cell line
To ensure self-renewal, stem cells undergo two types of cell division (see Stem cell division and differentiation diagram). Symmetric division gives rise to two identical daughter cells both endowed with stem cell properties. Asymmetric division, on the other hand, produces only one stem cell and a progenitor cell with limited self-renewal potential. Progenitors can go through several rounds of cell division before terminally differentiating into a mature cell. It is possible that the molecular distinction between symmetric and asymmetric divisions lies in differential segregation of cell membrane proteins (such as receptors) between the daughter cells.[23]
An alternative theory is that stem cells remain undifferentiated due to environmental cues in their particular niche. Stem cells differentiate when they leave that niche or no longer receive those signals. Studies in Drosophila germarium have identified the signals dpp and adherins junctions that prevent germarium stem cells from differentiating.[24][25]
Main article: Induced Pluripotent Stem Cell
The signals that lead to reprogramming of cells to an embryonic-like state are also being investigated. These signal pathways include several transcription factors including the oncogene c-Myc. Initial studies indicate that transformation of mice cells with a combination of these anti-differentiation signals can reverse differentiation and may allow adult cells to become pluripotent.[26] However, the need to transform these cells with an oncogene may prevent the use of this approach in therapy.
Treatments
Main article: Stem cell treatments
Medical researchers believe that stem cell therapy has the potential to dramatically change the treatment of human disease. A number of adult stem cell therapies already exist, particularly bone marrow transplants that are used to treat leukemia.[27] In the future, medical researchers anticipate being able to use technologies derived from stem cell research to treat a wider variety of diseases including cancer, Parkinson's disease, spinal cord injuries, Amyotrophic lateral sclerosis and muscle damage, amongst a number of other impairments and conditions.[28][29] However, there still exists a great deal of social and scientific uncertainty surrounding stem cell research, which could possibly be overcome through public debate and future research, and further education of the public.
Stem cells, however, are already used extensively in research, and some scientists do not see cell therapy as the first goal of the research, but see the investigation of stem cells as a goal worthy in itself.[30]
Controversy surrounding human embryonic stem cell research
Main article: Stem cell controversy
There exists a widespread controversy over human embryonic stem cell research that emanates from the techniques used in the creation and usage of stem cells. Human embryonic stem cell research is controversial because, with the present state of technology, starting a stem cell line requires the destruction of a human embryo and/or therapeutic cloning. However, recently, it has been shown in principle that adult stem cell lines can be manipulated to generate embryonic-like stem cell lines using a single-cell biopsy similar to that used in preimplantation genetic diagnosis that may allow stem cell creation without embryonic destruction.[31] It is not the entire field of stem cell research, but the specific field of human embryonic stem cell research that is at the centre of an ethical debate.
Opponents of the research argue that embryonic stem cell technologies are a slippery slope to reproductive cloning and can fundamentally devalue human life. Those in the pro-life movement argue that a human embryo is a human life and is therefore entitled to protection.
Contrarily, supporters of embryonic stem cell research argue that such research should be pursued because the resultant treatments could have significant medical potential. It is also noted that excess embryos created for in vitro fertilization could be donated with consent and used for the research.
The ensuing debate has prompted authorities around the world to seek regulatory frameworks and highlighted the fact that stem cell research represents a social and ethical challenge.
Key stem cell research events
1908 - The term "stem cell" was proposed for scientific use by the Russian histologist Alexander Maksimov (1874-1928) at congress of hematologic society in Berlin. It postulated existence of haematopoietic stem cells.
1960s - Joseph Altman and Gopal Das present scientific evidence of adult neurogenesis, ongoing stem cell activity in the brain; their reports contradict Cajal's "no new neurons" dogma and are largely ignored.
1963 - McCulloch and Till illustrate the presence of self-renewing cells in mouse bone marrow.
1968 - Bone marrow transplant between two siblings successfully treats SCID.
1978 - Haematopoietic stem cells are discovered in human cord blood.
1981 - Mouse embryonic stem cells are derived from the inner cell mass by scientists Martin Evans, Matthew Kaufman, and Gail R. Martin. Gail Martin is attributed for coining the term "Embryonic Stem Cell".
1992 - Neural stem cells are cultured in vitro as neurospheres.
1997 - Leukemia is shown to originate from a haematopoietic stem cell, the first direct evidence for cancer stem cells.
1998 - James Thomson and coworkers derive the first human embryonic stem cell line at the University of Wisconsin-Madison.[32]
2000s - Several reports of adult stem cell plasticity are published.
2001 - Scientists at Advanced Cell Technology clone first early (four- to six-cell stage) human embryos for the purpose of generating embryonic stem cells.[33]
2003 - Dr. Songtao Shi of NIH discovers new source of adult stem cells in children's primary teeth.[34]
2004-2005 - Korean researcher Hwang Woo-Suk claims to have created several human embryonic stem cell lines from unfertilised human oocytes. The lines were later shown to be fabricated.
2005 - Researchers at Kingston University in England claim to have discovered a third category of stem cell, dubbed cord-blood-derived embryonic-like stem cells (CBEs), derived from umbilical cord blood. The group claims these cells are able to differentiate into more types of tissue than adult stem cells.
August 2006 - Rat Induced pluripotent stem cells: the journal Cell publishes Kazutoshi Takahashi and Shinya Yamanaka, "Induction of Pluripotent Stem Cells from Mouse Embryonic and Adult Fibroblast Cultures by Defined Factors".
October 2006 - Scientists at Newcastle University in England create the first ever artificial liver cells using umbilical cord blood stem cells.[35][36]
January 2007 - Scientists at Wake Forest University led by Dr. Anthony Atala and Harvard University report discovery of a new type of stem cell in amniotic fluid.[5] This may potentially provide an alternative to embryonic stem cells for use in research and therapy.[37]
June 2007 - Research reported by three different groups shows that normal skin cells can be reprogrammed to an embryonic state in mice.[38] In the same month, scientist Shoukhrat Mitalipov reports the first successful creation of a primate stem cell line through somatic cell nuclear transfer[39]
October 2007 - Mario Capecchi, Martin Evans, and Oliver Smithies win the 2007 Nobel Prize for Physiology or Medicine for their work on embryonic stem cells from mice using gene targeting strategies producing genetically engineered mice (known as knockout mice) for gene research.[40]
November 2007 - Human Induced pluripotent stem cells: Two similar papers released by their respective journals prior to formal publication: in Cell by Kazutoshi Takahashi and Shinya Yamanaka, "Induction of Pluripotent Stem Cells from Adult Human Fibroblasts by Defined Factors", and in Science by Junying Yu, et al., from the research group of James Thomson, "Induced Pluripotent Stem Cell Lines Derived from Human Somatic Cells": pluripotent stem cells generated from mature human fibroblasts. It is possible now to produce a stem cell from almost any other human cell instead of using embryos as needed previously, albeit the risk of tumorigenesis due to c-myc and retroviral gene transfer remains to be determined.
January 2008 - Robert Lanza and colleagues at Advanced Cell Technology and UCSF create the first human embryonic stem cells without destruction of the embryo[41]
January 2008 - Development of human cloned blastocysts following somatic cell nuclear transfer with adult fibroblasts[42]
February 2008 - Generation of Pluripotent Stem Cells from Adult Mouse Liver and Stomach: these iPS cells seem to be more similar to embryonic stem cells than the previous developed iPS cells and not tumorigenic, moreover genes that are required for iPS cells do not need to be inserted into specific sites, which encourages the development of non-viral reprogramming techniques. [43][44]
March 2008-The first published study of successful cartilage regeneration in the human knee using autologous adult mesenchymal stem cells is published by Clinicians from Regenerative Sciences[45]
October 2008 - Sabine Conrad and colleagues at Tübingen, Germany generate pluripotent stem cells from spermatogonial cells of adult human testis by culturing the cells in vitro under leukemia inhibitory factor (LIF) supplementation. [46]
Stem cell funding & policy debate in the US
1993 - As per the National Institutes of Health Revitalization Act, Congress and President Bill Clinton give the NIH direct authority to fund human embryo research for the first time.[47]
1995 - The U.S. Congress passes an appropriations bill attached to which is the Dickey Amendment which prohibited federally appropriated funds to be used for research where human embryos would be either created or destroyed. This predates the creation of the first human embryonic stem cell lines. The bill is signed into law by President Clinton.
1999 - After the creation of the first human embryonic stem cell lines in 1998 by James Thomson of the University of Wisconsin, Harriet Rabb, the top lawyer at the Department of Health and Human Services, releases a legal opinion that would set the course for Clinton Administration policy. Federal funds, obviously, could not be used to derive stem cell lines (because derivation involves embryo destruction). However, she concludes that because human embryonic stem cells "are not a human embryo within the statutory definition," the Dickey-Wicker Amendment does not apply to them. The NIH was therefore free to give federal funding to experiments involving the cells themselves. President Clinton strongly endorses the new guidelines, noting that human embryonic stem cell research promised "potentially staggering benefits." And with the guidelines in place, the NIH begins accepting grant proposals from scientists.[47]
02 November, 2004 - California voters approve Proposition 71, which provides $3 billion in state funds over ten years to human embryonic stem cell research.
2001-2006 - U.S. President George W. Bush signs an executive order which restricts federally-funded stem cell research on embryonic stem cells to the already derived cell lines. He supports federal funding for embryonic stem cell research on the already existing lines of approximately $100 million and $250 million for research on adult and animal stem cells.
5 May, 2006 - Senator Rick Santorum introduces bill number S. 2754, or the Alternative Pluripotent Stem Cell Therapies Enhancement Act, into the U.S. Senate.
18 July, 2006 - The U.S. Senate passes the Stem Cell Research Enhancement Act H.R. 810 and votes down Senator Santorum's S. 2754.
19 July, 2006 - President George W. Bush vetoes H.R. 810 (Stem Cell Research Enhancement Act), a bill that would have reversed the Dickey Amendment which made it illegal for federal money to be used for research where stem cells are derived from the destruction of an embryo.
07 November, 2006 - The people of the U.S. state of Missouri passed Amendment 2, which allows usage of any stem cell research and therapy allowed under federal law, but prohibits human reproductive cloning.[48]
16 February, 2007 – The California Institute for Regenerative Medicine became the biggest financial backer of human embryonic stem cell research in the United States when they awarded nearly $45 million in research grants.[49]
04 November, 2008 - The people of the U.S. state of Michigan passed Proposal 08-2, allowing Michigan researchers to make embryonic stem cell cultures from excess embryos donated from fertility treatments.[50]
See also
The American Society for Cell Biology
California Institute for Regenerative Medicine
Genetics Policy Institute
Cancer stem cells
Induced Pluripotent Stem Cell (iPS Cell)
Odontis
Meristem
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External links
General
Tell Me About Stem Cells: Quick and simple guide explaining the science behind stem cells
Stem Cell Basics
Nature Reports Stem Cells: Introductory material, research advances and debates concerning stem cell research.
Understanding Stem Cells: A View of the Science and Issues from the National Academies
Scientific American Magazine (June 2004 Issue) The Stem Cell Challenge
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World first as woman gets organ made from stem cells
http://news.scotsman.com/latestnews/World-first-as-woman-gets.4706821.jp
Date: 19 November 2008
By TANYA THOMPSON
A WOMAN has become the first patient in the world to receive an organ created in a laboratory, in a pioneering operation that could change transplant surgery, doctors said yesterday.
Claudia Castillo's body part was grown using her own stem cells harvested from bone marrow.
Professor Anthony Hollander, part of the team behind the breakthrough, described it as an example of "stem cell science becoming stem cell medicine".
UADVERTISEMENTsing Ms Castillo's stem cells to create a new airway for her means there are none of the tissue-rejection problems that are a major issue for transplant surgery and which usually mean recipients have to take powerful drugs for the rest of their lives.
Researchers from the UK, Italy and Spain worked together in the extraordinarily complex procedure to grow tissue from the 30-year-old mother of two to fashion a new bronchus – a branch of the windpipe – and carry out the transplant operation.
Scientists believe the same approach will be used in years to come to create engineered replacements for other damaged organs. In five years, they hope to begin clinical trials in which laboratory-made voice boxes are implanted into patients with cancer of the larynx.
Professor Martin Birchall, a member of the team from the University of Bristol, said: "What we're seeing today is just the beginning. This is the first time a tissue-engineered whole organ has been transplanted into a patient.
"I reckon in 20 years' time, it will be the commonest operation surgeons will be doing. I think it will completely transform the way we think about surgery, health and disease."
He predicted the technique could be applied to other hollow organs similar in structure, such as the bowel, bladder and reproductive tract.
Colombian-born Ms Castillo, from Barcelona, Spain, had suffered a serious tuberculosis infection that ravaged her airways, leaving her short of breath and unable to carry out the simplest tasks.
Disease had caused her windpipe, or trachea, to collapse at the point where it entered her left lung.
A series of complex steps pushing the boundaries of medical science led to the transplant operation, performed on 12 June by Professor Paolo Macchiarini at the Hospital Clinic of Barcelona.
A section of windpipe was taken from a female donor who had died and the trachea was stripped of its cells, leaving only connective tissue. Stem cells from Ms Castillo's bone marrow were then grown in the laboratory. Next, the donor trachea had to be "seeded" with two different kinds of cells – those made in the laboratory and those derived from tissue taken from Ms Castillo's nose and healthy airways.
The trachea graft was placed into a rotating "bioreactor" and the machine allowed the cells to migrate to the correct locations, where they began to grow naturally.
Finally the trachea, now covered in cartilage and lined with cells all bearing the patient's own genetic hallmark, was cut to shape and slotted into place. Without the pioneering operation, the lung would have had to be removed.
Today, Ms Castillo is living an active, normal life, and is once again able to look after her children, Johan, 15, and Isabella, four. Yesterday, she said: "I was scared at the beginning because I was the first patient but had confidence and trusted the doctors. I am now enjoying life and am very happy that my illness has been cured."
So far, doctors have seen no sign of her immune system rejecting the transplanted organ, even though she received no immunosuppressive drugs.
Prof Birchall admitted the decision to turn to tissue engineering to help Ms Castillo had been a "leap of faith" and the same procedure had only been attempted on pigs before.
Details of the transplant were described in a online edition of The Lancet journal.
Prof Macchiarini said: "We are terribly excited by these results. Just four days after transplantation, the graft was almost indistinguishable from adjacent, normal bronchi."
Dr Allan Kirk, from the American Society of Transplantation, said: "They have created a functional, biological structure that can't be rejected."
However, Dr Josh Brickman, from the Institute for Stem Cell Research in Edinburgh, urged caution. "It is fantastic that they have been able to do this with her own stem cells, which means there is no risk of auto-immune rejection. However, the application to other organs could be difficult," he said.
Sue Pearson, from the Transplant Trust, said: "This is great news, but we don't want to give false hope to people who are waiting for organs. We're sure that this will come to fruition in the future. In the meantime, we would encourage people to sign on to the organ donor register and talk to their next of kin."
Scientists are already looking to the future and seeking European Union funding and commercial sponsors for the more ambitious larynx trials.
Up to 60,000 people a year are diagnosed with cancer of the larynx in Europe, about half of whom may be suitable for tissue engineering transplants.
Since the larynx is a complex organ containing the vocal cords, engineering one from stem cells will be a major challenge. But Prof Birchall said the first trials could take place in about five years.
Professor Martin Birchall - 'I think it will completely transform the way we think about surgery, health and disease'
How the procedure works
1 A section of windpipe, or trachea, was taken from a 51-year-old woman donor who had died, to provide the scaffold or "matrix" around which the new bronchus would be built.
2 Using a pioneering technique involving detergent and enzymes, the trachea was stripped of its cells, leaving connective tissue. The process removed almost all the material that could trigger an adverse immune reaction.
3 Stem cells from the patient's own bone marrow were then grown and multiplied in the laboratory, and treated with "growth factor" chemicals to turn them into cartilage cells called chondrocytes.
4 Stem cells are immature cells with the ability to develop into many kinds of tissue given the right chemical instructions.
5 The 7cm-long donor trachea had to be "seeded" with two kinds of cells – the chondrocytes made in Bristol and specialised epithelial cells derived from tissue taken from the patient's nose and healthy airways. The epithelial cells line the inside of the tracheal tube and carry tiny hairs or cilia for moving debris out of the airway.
6 The seeding process was carried out by placing the trachea graft into a rotating "bioreactor" developed at the Polytechnic of Milan in Italy. The machine allowed the cells to migrate to the right locations, where they began to grow naturally.
7 Finally the trachea, now covered in cartilage and lined with epithelial cells all bearing the patient's genetic hallmark, was cut to shape and slotted into the gap left by the diseased and collapsed bronchus.
Overcoming the problems of immune rejection by using a patient's own cells is a major breakthrough
THIS work is important because it demonstrates how tissue engineers can work together with stem-cell biologists to produce material from a patient's own cells that will not be rejected by their immune system.
To produce something that can be surgically implanted and – so far as we know – not suffer any complications is really quite remarkable.
To get over the problem of immune rejection by being able to use the patient's own cells is a major breakthrough in its own right in terms of transplant.
At the moment, this cannot be used on a huge scale because it is such a patient-specific treatment, but it is a wonderful demonstration of the fact that stem cells can be used in this way and to the benefit of patients.
I can see a time when a treatment like this will be used on the NHS in specific disease cases.
The research is a major step forward to realising regenerative medicine. It is certainly important and one more step along the way. We are not yet where we aim to be in regenerative medicine, but this is helping us get there.
In terms of the developments being made in stem-cell research at the moment, we have a number of clinical trials using treatments based on adult stem cells under way in the UK. There are even more under way in the United States.
The theory has always been there to use adult stem cells and expand them into more than just blood stem cells.
It will lead to potentially more surgeons trying this sort of surgery and using tissue engineers alongside stem-cell biologists to create parts of organs that can be transplanted. This is a procedure that is risky. It does not have any guarantees, and no doubt this patient has been very bold and gone through with it because she has confidence in the doctors and the surgeons.
Patients who are suffering from chronic conditions should be able to look at this piece of work and make their own mind up based on the risk.
If they see in the longer term, as I hope it turns out, that this patient has improved quality of life and for a long period of time, then that ought to encourage others to try this sort of surgery through their own doctors.
It is always important that we have patients who are willing to take part in clinical trials.
One issue in progressing with stem-cell research is having the patients who will enter into this kind of work. This is one of the issues that the network will be discussing at a meeting in London next week.
Though we may be cautious while we await the longer-term results, all the signs are there that this is a tremendous piece of research and surgery.
I think it is a major advance and hugely encouraging in our aim to develop regenerative medicine further.
• Ben Sykes is co-ordinator of the UK National Stem Cell Network.
Wednesday, November 5, 2008
Japanese clone mouse from frozen cell, aim for mammoths
Japanese clone mouse from frozen cell, aim for mammoths
by Kyoko Hasegawa Kyoko Hasegawa – Tue Nov 4, 3:31 am ET AFP – This handout picture, released by Japan natural science research center shows a cloned mouse (left) created … TOKYO (AFP) – Japanese scientists said Tuesday they had created a mouse from a dead cell frozen for 16 years, taking a step in the long impossible dream of bringing back extinct animals such as mammoths.
Scientists at the government-backed research institute Riken used the dead cell of a mouse that had been preserved at minus 20 degrees Celsius (minus 4 degrees Fahrenheit) -- a temperature similar to frozen ground.
The scientists hope that the first-of-a-kind research will pave the way to restore extinct animals such as the mammoth.
The findings were published in the Proceedings of the National Academy of Sciences in the United States.
The scientists extracted a cell nucleus from an organ of the dead mouse and planted it into an egg of another mouse which was alive, leading to the birth of the cloned mouse, the researchers said.
"The newly developed technology of nucleus transfer greatly improved the possibility of reviving extinct animals," the research team led by Teruhiko Wakayama said in a statement.
"Even though reviving extinct animals is often described in films and novels -- such as in Michael Crichton's 'Jurassic Park' -- it had in reality been impossible," they said.
Cells from dead bodies have previously been useless as they are ruined in the freezing process. But Wakayama's team discovered a way to extract a nucleus intact from a frozen cell by grinding cell tissues into multiple pieces.
The cloned mouse was able to reproduce with a female mouse, it added.
But the researchers said tough challenges remain ahead in terms of how to restore extinct animals, which would require breeding with animals that are still alive.
To revive a mammoth, researchers would need to find a way to implant a cell nucleus of a mammoth into the egg of an elephant and then implant the embryo into an elephant's uterus, it said.
The elephant is the closest modern relative of the mammoth, a huge woolly mammal believed to have died out with the Ice Age.
But Akira Iritani, a mammoth expert at Kinki University in Osaka, said it was only a matter of time before researchers could find a mammoth for a resurrection project.
"I have high hopes that we will be able to find a fine sample," he told public broadcaster NHK.
"It's said that there are more than 10,000 mammoths lying underneath Siberia," he said.
Even if it is impossible to recreate a whole animal, the process could create cloned embryonic stem cells for extinct species, giving a boost to research on evolution and zoology, he said.
Cloning can be controversial in terms of both bioethics and, if the animals are eaten, food safety.
Earlier this year, a report by the European Union warned that cloning can threaten the health of livestock.
South Korea's parliament has passed a law to regulate research into cloning, following a scandal in which a now-disgraced expert falsely claimed to have made the first human clone stem cells.
Wednesday, October 22, 2008
Internet use 'good for the brain'
http://news.bbc.co.uk/2/hi/health/7667610.stm
Areas activated by reading a book in the brain of an experienced web user
For middle-aged and older people at least, using the internet helps boost brain power, research suggests.
A University of California Los Angeles team found searching the web stimulated centres in the brain that controlled decision-making and complex reasoning.
The researchers say this might even help to counteract the age-related physiological changes that cause the brain to slow down.
The study features in the American Journal of Geriatric Psychiatry.
A simple, everyday task like searching the web appears to enhance brain circuitry in older adults
Professor Gary Small
University of California Los Angeles
As the brain ages, a number of changes occur, including shrinkage and reductions in cell activity, which can affect performance.
It has long been thought that activities which keep the brain active, such as crossword puzzles, may help minimise that impact - and the latest study suggests that surfing the web can be added to the list.
Web use stimulates much more activity in the same brain
Lead researcher Professor Gary Small said: "The study results are encouraging, that emerging computerised technologies may have physiological effects and potential benefits for middle-aged and older adults.
"Internet searching engages complicated brain activity, which may help exercise and improve brain function."
The latest study was based on 24 volunteers aged between 55 and 76. Half were experienced internet users, the rest were not.
Compared with reading
Each volunteer underwent a brain scan while performing web searches and book-reading tasks.
Both types of task produced evidence of significant activity in regions of the brain controlling language, reading, memory and visual abilities.
However, the web search task produced significant additional activity in separate areas of the brain which control decision-making and complex reasoning - but only in those who were experienced web users.
Brain activity in web newcomers: similar for reading and internet use
The researchers said that, compared to simple reading, the internet's wealth of choices required people to make decisions about what to click on in order to get the relevant information.
However, they suggested that newcomers to the web had not quite grasped the strategies needed to successfully carry out a web search.
Professor Smith said: "A simple, everyday task like searching the web appears to enhance brain circuitry in older adults, demonstrating that our brains are sensitive and can continue to learn as we grow older."
Rebecca Wood, chief executive of the Alzheimer’s Research Trust, said: "These fascinating findings add to previous research suggesting that middle-aged and older people can reduce their risk of dementia by taking part in regular mentally stimulating activities.
"Older web users - 'silver surfers' - are doing precisely this.
"Frequent social interactions, regular exercise and maintaining a balanced diet can also reduce dementia risk."
Dr Susanne Sorensen, head of research at the Alzheimer's Society, said: "Use it or lose it may well be a positive message to keep people active but there is very little real evidence that keeping the brain exercised with puzzles, games or other activities can promote cognitive health and reduce the risk of dementia."
Sunday, September 28, 2008
China astronauts return after historic mission
Photo: AFP
BEIJING (AFP) - Three astronauts who conducted China's first-ever space walk landed safely back on Chinese soil on Sunday, bringing an end to the latest historic mission by the country's young space programme.
The descent capsule of the Shenzhou VII spacecraft drifted down to a soft landing in northern China's Inner Mongolia region in footage broadcast live on state-run CCTV.
BEIJING (AFP) - Three astronauts who conducted China's first-ever space walk landed safely back on Chinese soil on Sunday, bringing an end to the latest historic mission by the country's young space programme.
The descent capsule of the Shenzhou VII spacecraft drifted down to a soft landing in northern China's Inner Mongolia region in footage broadcast live on state-run CCTV.
Within minutes, technicians reached the capsule by car and began helping Zhai and fellow crew members Liu Boming and Jing Haipeng out.
"I feel proud for the nation," commander Zhai Zhigang told a television crew that arrived at the site.
The trio were then quickly whisked away for medical checks.
Their return came a day after Zhai conducted the spacewalk, making China just the third country to perform the feat after the United States and the former Soviet Union four decades ago.
The mission has been hailed in China as a landmark in the country's quest to become a space power.
Under China's fledgling space programme, two more unmanned craft will be launched by 2010, as well as another manned spaceship with a crew of three to start work on building a lab or space station, according to state media.
After China sent its first man into space in 2003, it followed up with a two-man mission in 2005.
Thursday, September 25, 2008
Explosion rattles Yangon amid tight security
The Associated Press
Thursday, September 25, 2008
YANGON, Myanmar: An explosion went off in Myanmar's main city Thursday amid tight security to mark the one-year anniversary of the junta's crackdown on pro-democracy protesters.
Three people appeared to have been lightly wounded by the morning blast near Yangon's City Hall, said witnesses who spoke on condition of anonymity fearing reprisals from the junta.
The explosion occurred at a bus stop near City Hall, which was central to street protests led by Buddhist monks a year ago
Riot police poured into the area and sealed it off with yellow tape, adding to the already-tight security in place around the city since late August.
"The explosion shook my building and made a very loud noise," said Thein Myint, who owns a stationary shop about 100 yards (meters) from where the blast went off.
The junta, which has been in power since 1962, sparked global outrage last year when it showed it would kill its own people in order to maintain power.
At least 31 people were killed when troops fired on protesters Sept. 26-27, 2007, violently crushing the peaceful uprising against the military government. The anti-government protests were the biggest demonstrations in the country in 20 years.
China plans first spacewalk
http://www.usatoday.com/tech/science/space/2008-09-24-chinaspace_N.htm?csp=34
Yahoo! Buzz Digg Newsvine Reddit FacebookWhat's this?By Calum MacLeod, USA TODAY
BEIJING — From a secretive desert town in China's northwest, the country will launch its third manned spaceflight Thursday, which will feature the nation's first spacewalk.
Chinese television will broadcast the takeoff from the Jiuquan satellite launch center in Gansu province, as well as the spacewalk, for the public to view another milestone soon after last month's Olympic Games in Beijing.
Russian technicians will provide support for the spacewalk during the Shenzhou 7 mission, according to the state-run Xinhua News Agency.
Two of the three "taikonauts" on board will suit up, but only one will step into space for about 40 minutes, 213 miles above Earth. The spacewalk could be Friday or Saturday.
"We are confident, determined and able to take the first step of Chinese people in space," astronaut Jin Haipeng told reporters Wednesday. Jin and the two other astronauts — including Zhai Zhigang, who is likely to make the spacewalk — are fighter pilots, all age 42, and have lived and trained together for the past decade.
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China's "Divine Vessel" spacecraft, powered by China's Long March rockets, will blast off at around 9 a.m. Thursday ET (9 p.m. in China), weather permitting, for a mission that will last three to five days.
The Shenzhou 7 is scheduled to land in the central area of Inner Mongolia in northern China.
The spacewalk marks a milestone in China's fast-developing space program, a multimillion-dollar, military-backed operation that has excited this nation of 1.3 billion people, and whose secrecy has worried NASA and China's Asian neighbors.
Chinese officials deny any military purpose to its space program.
"So far, China's manned space program hasn't carried out a single military task," said Cui Jijun, director of the Jiuquan center, according to Xinhua. Cui said the manned space program is scientific exploration that could boost technology and innovation.
In the 1950s, Chairman Mao Zedong complained that China could not even shoot a potato into space, but the nation has caught up quickly in recent years.
In 2003, China became the third nation after the United States and Russia to send a man into space. China sent two astronauts up in 2005 for its second spaceflight.
Top Chinese scientists have openly discussed long-term plans to land a man on the moon and to build a space station.
NASA chief Mike Griffin told a U.S. congressional hearing in February that China is becoming a more serious competitor in manned spaceflight.
The spacewalk "is a big technical step forward," said Joan Johnson-Freese, an expert on China's space program at the U.S. Naval War College in Newport, R.I. "If they show it live (on TV), that shows a marked increase in their own confidence."
The payoffs can be considerable, Johnson-Freese said.
The Chinese "basically studied our Apollo program playbook and want those multiple benefits," she said. China's space program "gives the communist government great prestige and credit from its people, just like the Olympic Games. Economically, it shows the rest of the world that if you can do space technology, you can do a lot more than knock off designer clothing."
The spacewalk is being closely watched at Beijing University of Aeronautics and Astronautics, where one-third of the 23,000 students are directly involved in aerospace.
"Some people may say that China still has many poor people and the space program is expensive, but we need all-round development," says student Chen Shichun, 21. "Space can help develop technologies that boost the economy for everyone."
One example is the "space vegetable" experiment, in which scientists sent plant seeds into space, then cultivated them into super-large vegetables on Earth.
This latest mission will release a communication satellite to film the spacewalk and could be used for a future space station.
The Chinese spacecraft borrows heavily from the Soviet Soyuz design, and Chinese astronauts have trained in Russia.
In the future, China may train foreign astronauts, said Chen Shanguang, the head of the China Astronaut Research and Training Center, according to Xinhua.
"International cooperation is an inevitable trend in manned space flights, which are large-scale projects with complex technologies and huge investment," he said.
The United States remains far ahead of China's program. "What China is doing is pretty spartan and prudent," Johnson-Freese said.
Wednesday, September 10, 2008
Massive particle collider passes first key tests
Massive particle collider passes first key tests
By ALEXANDER G. HIGGINS, Associated Press Writer
3 minutes ago
GENEVA - The world's largest particle collider passed its first major tests by firing two beams of protons in opposite directions around a 17-mile (27-kilometer) underground ring Wednesday in what scientists hope is the next great step to understanding the makeup of the universe.
After a series of trial runs, two white dots flashed on a computer screen at 10:26 a.m. (0826 GMT) indicating that the protons had traveled clockwise along the full length of the 4 billion Swiss franc (US$3.8 billion) Large Hadron Collider — described as the biggest physics experiment in history.
"There it is," project leader Lyn Evans said when the beam completed its lap.
Champagne corks popped in labs as far away as Chicago, where contributing and competing scientists watched the proceedings by satellite.
Five hours later, scientists successfully fired a beam counterclockwise.
Physicists around the world now have much greater power to smash the components of atoms together in attempts to learn about their structure.
"Well done, everybody," said Robert Aymar, director-general of the European Organization for Nuclear Research, to cheers from the assembled scientists in the collider's control room at the Swiss-French border.
The organization, known by its French acronym CERN, began firing the protons — a type of subatomic particle — around the tunnel in stages less than an hour earlier, with the first beam injection at 9:35 a.m. (0735 GMT).
Eventually two beams will be fired at the same time in opposite directions with the aim of recreating conditions a split second after the big bang, which scientists theorize was the massive explosion that created the universe.
"My first thought was relief," said Evans, who has been working on the project since its inception in 1984. "This is a machine of enormous complexity. Things can go wrong at any time. But this morning has been a great start."
He didn't want to set a date, but said that he expected scientists would be able to conduct collisions for their experiments "within a few months."
The collider is designed to push the proton beam close to the speed of light, whizzing 11,000 times a second around the tunnel.
Scientists hope to eventually send two beams of protons through two tubes about the width of fire hoses, speeding through a vacuum that is colder and emptier than outer space. The paths of these beams will cross, and a few protons will collide. The collider's two largest detectors — essentially huge digital cameras weighing thousands of tons — are capable of taking millions of snapshots a second.
The CERN experiments could reveal more about "dark matter," antimatter and possibly hidden dimensions of space and time. It could also find evidence of the hypothetical particle — the Higgs boson — which is sometimes called the "God particle" because it is believed to give mass to all other particles, and thus to matter that makes up the universe.
The supercooled magnets that guide the proton beam heated slightly in the morning's first test, leading to a pause to recool them before trying the opposite direction.
The start of the collider came over the objections of some who feared the collision of protons could eventually imperil the Earth by creating micro-black holes, subatomic versions of collapsed stars whose gravity is so strong they can suck in planets and other stars.
"It's nonsense," said James Gillies, chief spokesman for CERN.
CERN was backed by leading scientists like Britain's Stephen Hawking , who declared the experiments to be absolutely safe.
Gillies told the AP that the most dangerous thing that could happen would be if a beam at full power were to go out of control, and that would only damage the accelerator itself and burrow into the rock around the tunnel.
Nothing of the sort occurred Wednesday, though the accelerator is still probably a year away from full power.
The project organized by the 20 European member nations of CERN has attracted researchers from 80 nations. Some 1,200 are from the United States, an observer country that contributed US$531 million. Japan, another observer, also is a major contributor.
Some scientists have been waiting for 20 years to use the LHC.
The complexity of manufacturing it required groundbreaking advances in the use of supercooled, superconducting equipment. The 2001 start and 2005 completion dates were pushed back by two years each, and the cost of the construction was 25 percent higher than originally budgeted in 1996, Luciano Maiani, who was CERN director-general at the time, told The Associated Press.
Maiani and the other three living former directors-general attended the launch Wednesday.
Smaller colliders have been used for decades to study the makeup of the atom. Less than 100 years ago scientists thought protons and neutrons were the smallest components of an atom's nucleus, but in stages since then experiments have shown they were made of still smaller quarks and gluons and that there were other forces and particles.
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On the Net:
CERN: http://www.cern.ch
The U.S. at the LHC: http://www.uslhc.us/
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