Monday, December 10, 2012




Using HIV to Cure a Cancer


Jeff Swensen for The New York Times
Emma Whitehead, with her mother, Kari. Last spring, Emma was near death from acute lymphoblastic leukemia but is now in remission after an experimental treatment at the Children’s Hospital of Philadelphia. More Photos »

PHILIPSBURG, Pa. — Emma Whitehead has been bounding around the house lately, practicing somersaults and rugby-style tumbles that make her parents wince.
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Readers’ Comments

"As an M.D. I tend to cringe at the reaction to these articles. This treatment was a big gamble, and one worth taking, but all to often these decisions are judged by their (unpredictable) outcomes."
JW, NY
It is hard to believe, but last spring Emma, then 6, was near death from leukemia. She had relapsed twice afterchemotherapy, and doctors had run out of options.
Desperate to save her, her parents sought an experimental treatment at the Children’s Hospital of Philadelphia, one that had never before been tried in a child, or in anyone with the type of leukemia Emma had. The experiment, in April, used a disabled form of the virus that causes AIDS to reprogram Emma’s immune system genetically to kill cancer cells.
The treatment very nearly killed her. But she emerged from it cancer-free, and about seven months later is still in complete remission. She is the first child and one of the first humans ever in whom new techniques have achieved a long-sought goal — giving a patient’s own immune system the lasting ability to fight cancer.
Emma had been ill with acute lymphoblastic leukemia since 2010, when she was 5, said her parents, Kari and Tom. She is their only child.
She is among just a dozen patients with advanced leukemiato have received the experimental treatment, which was developed at the University of Pennsylvania. Similar approaches are also being tried at other centers, including the National Cancer Institute and Memorial Sloan-Kettering Cancer Center in New York.
“Our goal is to have a cure, but we can’t say that word,” said Dr. Carl June, who leads the research team at the University of Pennsylvania. He hopes the new treatment will eventually replace bone-marrow transplantation, an even more arduous, risky and expensive procedure that is now the last hope when other treatments fail in leukemia and related diseases.
Three adults with chronic leukemia treated at the University of Pennsylvania have also had complete remissions, with no signs of disease; two of them have been well for more than two years, said Dr. David Porter. Four adults improved but did not have full remissions, and one was treated too recently to evaluate. A child improved and then relapsed. In two adults, the treatment did not work at all. The Pennsylvania researchers were presenting their results on Sunday and Monday in Atlanta at a meeting of the American Society of Hematology.
Despite the mixed results, cancer experts not involved with the research say it has tremendous promise, because even in this early phase of testing it has worked in seemingly hopeless cases. “I think this is a major breakthrough,” said Dr. Ivan Borrello, a cancer expert and associate professor of medicine at the Johns Hopkins University School of Medicine.
Dr. John Wagner, the director of pediatric blood and marrow transplantation at the University of Minnesota, called the Pennsylvania results “phenomenal” and said they were “what we’ve all been working and hoping for but not seeing to this extent.”
A major drug company, Novartis, is betting on the Pennsylvania team and has committed $20 million to building a research center on the university’s campus to bring the treatment to market.
HervĂ© Hoppenot, the president of Novartis Oncology, called the research “fantastic” and said it had the potential — if the early results held up — to revolutionize the treatment of leukemia and related blood cancers. Researchers say the same approach, reprogramming the patient’s immune system, may also eventually be used against tumors like breast andprostate cancer.
To perform the treatment, doctors remove millions of the patient’s T-cells — a type of white blood cell — and insert new genes that enable the T-cells to kill cancer cells. The technique employs a disabled form of H.I.V. because it is very good at carrying genetic material into T-cells. The new genes program the T-cells to attack B-cells, a normal part of the immune system that turn malignant in leukemia.
The altered T-cells — called chimeric antigen receptor cells — are then dripped back into the patient’s veins, and if all goes well they multiply and start destroying the cancer.
The T-cells home in on a protein called CD-19 that is found on the surface of most B-cells, whether they are healthy or malignant.
A sign that the treatment is working is that the patient becomes terribly ill, with raging fevers and chills — a reaction that oncologists call “shake and bake,” Dr. June said. Its medical name is cytokine-release syndrome, or cytokine storm, referring to the natural chemicals that pour out of cells in the immune system as they are being activated, causing fevers and other symptoms. The storm can also flood the lungs and cause perilous drops in blood pressure — effects that nearly killed Emma.
Steroids sometimes ease the reaction, but they did not help Emma. Her temperature hit 105. She wound up on a ventilator, unconscious and swollen almost beyond recognition, surrounded by friends and family who had come to say goodbye.
But at the 11th hour, a battery of blood tests gave the researchers a clue as to what might help save Emma: her level of one of the cytokines, interleukin-6 or IL-6, had shot up a thousandfold. Doctors had never seen such a spike before and thought it might be what was making her so sick.
Dr. June knew that a drug could lower IL-6 — his daughter takes it for rheumatoid arthritis. It had never been used for a crisis like Emma’s, but there was little to lose. Her oncologist, Dr. Stephan A. Grupp, ordered the drug. The response, he said, was “amazing.”
Within hours, Emma began to stabilize. She woke up a week later, on May 2, the day she turned 7; the intensive-care staff sang “Happy Birthday.”
Since then, the research team has used the same drug, tocilizumab, in several other patients.
In patients with lasting remissions after the treatment, the altered T-cells persist in the bloodstream, though in smaller numbers than when they were fighting the disease. Some patients have had the cells for years.
Dr. Michel Sadelain, who conducts similar studies at the Sloan-Kettering Institute, said: “These T-cells are living drugs. With a pill, you take it, it’s eliminated from your body and you have to take it again.” But T-cells, he said, “could potentially be given only once, maybe only once or twice or three times.”

Sunday, December 9, 2012



Racetrack Drugs Put Europe Off U.S. Horse Meat


PARIS — For decades, American horses, many of them retired or damaged racehorses, have been shipped to Canada and Mexico, where it is legal to slaughter horses, and then processed and sold for consumption in Europe and beyond.
Christinne Muschi for The New York Times
A slaughterhouse in Saint-André-Avellin, Quebec, where meat is processed for sale in Europe.
Multimedia
Christophe Simon/Agence France-Presse — Getty Images
A horse meat butcher shop in France.
Lately, however, European food safety officials have notified Mexican and Canadian slaughterhouses of a growing concern: The meat of American racehorses may be too toxic to eat safely because the horses have been injected repeatedly with drugs.
Despite the fact that racehorses make up only a fraction of the trade in horse meat, the European officials have indicated that they may nonetheless require lifetime medication records for slaughter-bound horses from Canada and Mexico, and perhaps require them to be held on feedlots or some other holding area for six months before they are slaughtered.
In October, Stephan Giguere, the general manager of a major slaughterhouse in Quebec, said he turned away truckloads of horses coming from the United States because his clients were worried about potential drug issues. Mr. Giguere said he told his buyers to stay away from horses coming from American racetracks.
“We don’t want them,” he said. “It’s too risky.”
The action is just the latest indication of the troubled state of American racing and its problems with the doping of horses. Some prominent trainers have been disciplined for using legal and illegal drugs, and horses loaded with painkillers have been breaking down in arresting numbers. Congress has called for reform, and state regulators have begun imposing stricter rules.
But for pure emotional effect, the alarm raised in the international horse-meat marketplace packs a distinctive punch.
Some 138,000 horses were sent to Canada or Mexico in 2010 alone to be turned into meat for Europe and other parts of the world, according to a Government Accountability Office report. Organizations concerned about the welfare of retired racehorses have estimated that anywhere from 10 to 15 percent of the population sent for slaughter may have performed on racetracks in the United States.
“Racehorses are walking pharmacies,” said Dr. Nicholas Dodman, a veterinarian on the faculty of Tufts University and a co-author of a 2010 article that sought to raise concerns about the health risks posed by American racehorses. He said it was reckless to want any of the drugs routinely administered to horses “in your food chain.”
Horses being shipped to Mexico and Canada are by law required to have been free of certain drugs for six months before being slaughtered, and those involved in their shipping must have affidavits proving that. But European Commission officials say the affidavits are easily falsified. As a result, American racehorses often show up in Canada within weeks — sometimes days — of their leaving the racetrack and their steady diets of drugs.
In October, the European Commission’s Directorate General for Health and Consumers found serious problems while auditing the operations of equine slaughter facilities in Mexico, where 80 percent of the horses arrive from the United States. The commission’s report said Mexican officials were not allowed to question the “authenticity or reliability of the sworn statements” about the ostensibly drug-free horses, and thus had no way of verifying whether the horses were tainted by drugs.
“The systems in place for identification, the food-chain information and in particular the affidavits concerning the nontreatment for six months with certain medical substances, both for the horses imported from the U.S. as well as for the Mexican horses, are insufficient to guarantee that standards equivalent to those provided for by E.U. legislation are applied,” the report said.
The authorities in the United States and Canada acknowledge that oversight of the slaughter business is lax. On July 9, the United States Food and Drug Administration sent a warning letter to an Ohio feedlot operator who sells horses for slaughter. The operator, Ronald Andio, was reprimanded for selling a drug-tainted thoroughbred horse to a Canadian slaughterhouse.
The Canadian Food Inspection Agency had tested the carcass of the horse the previous August and found the anti-inflammatory drug phenylbutazone in the muscle and kidney tissues. It also discovered clenbuterol, a widely abused medication for breathing problems that can build muscle by mimicking anabolic steroids.
Because horses are not a traditional food source in the United States, the Food and Drug Administration does not require human food safety information as it considers what drugs can be used legally on horses. Patricia El-Hinnawy, a spokeswoman for the agency, said agency-approved drugs intended for use in horses carried the warning “Do not use in horses intended for human consumption.”
A New York Times examination of American horse racing showed an industry still mired in a culture of drugs and inadequate regulation and a fatal breakdown rate that remains far worse than in most of the world. The examination found that 24 horses died each week at America’s racetracks and that in one recent three-year period, more than 3,800 horses had positive drug tests, mostly for illegally high levels of prescription drugs.

Friday, December 7, 2012


Science
IMMUNOLOGY

Platelets Kill the Parasite Within

  1. Michael F. Good2
+Author Affiliations
  1. 1Queensland Institute of Medical Research, Brisbane, QLD Australia.
  2. 2Institute for Glycomics, Griffith University, Gold Coast, QLD Australia.
  1. E-mail: michael.good@griffith.edu.au

The estimated 216 million cases of malaria in 2010 resulted in about 655,000 deaths, around 86% of which were children under the age of 5 (1), mainly in sub-Saharan Africa. Most of these deaths are caused by the protozoan parasite Plasmodium falciparum. Our poor understanding of innate resistance and the development of immunity to P. falciparum is an obstacle to developing vaccines and new therapeutics. The human body has numerous defenses to protect itself against severe forms of malaria. One such strategy, previously underappreciated, involves platelets—unnucleated fragments of megakaryocytes normally thought of as being critical solely to prevent hemorrhage. On page 1348 in this issue, McMorran et al. (2) reveal a mechanism by which platelets can recognize infected red blood cells and kill the parasite within (see the figure)
Destroying P. falciparum.
(A) Activated platelets containing PF4-laden granules bind to parasitized red blood cells that express the Duffy-antigen receptor. (B) Upon binding [through CD36 on platelets and a parasite receptor on the red blood cell, possibly P. falciparum erythrocyte membrane protein 1 (PfEMP-1) (15)], PF4 is released and binds to the Duffy-antigen receptor on red blood cells. (C) The PF4–Duffy-antigen receptor complex translocates into the cell, colocalizes with intracellular parasites, and then kills the parasites.
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NATURE NEWS BLOG

Space venture plans to ferry people to the Moon

GOLDEN SPIKE
In May, SpaceX rocketed up to the space station and showed that commercial cargo was possible. In the next several years, people could start riding those rockets, and commercial crew will come into being.
Next up, says Gerry Griffin, is what you might call ‘commercial Moon’. Griffin’s startup company, called Golden Spike, after the spike used to complete the first US transcontinental railroad, was unveiled on Thursday in Washington DC. The company plans to sell regular trips to the surface of the Moon for two people for about $1.4 billion — a price that Griffin thinks is within reach for many countries and corporations. “The time is ripe for commercial human lunar exploration,” says Griffin, former director of NASA’s Johnson Space Center in Houston, Texas.
More like an airline company rather than an aircraft manufacturer, Golden Spike has not committed to specific vendors who will build the various components for the mission, though Stern acknowledged that one mission formulation could rely on SpaceX rockets. The only piece that needs to be designed from scratch is the lunar lander.
It is entirely possible that those manufacturers could compete with Golden Spike. But one of those people, Elon Musk, the founder of SpaceX, has so far been more interested in going to Mars with a space capsule called Red Dragon. “He has no interest in ‘Grey Dragon’,” says Steve Mackwell, an adviser to Golden Spike and director of the Lunar and Planetary Institute in Houston, Texas.
Another issue is whether there is a big enough market. Stern says as many as 20 nations could afford the price tag, and would do it for reasons of prestige or science. Eventually, tourism might play a part. While the first mission would cost about $8 billion, the cost to Golden Spike would quickly come down upon subsequent missions. The company also plans to make money off of media rights, naming rights, and merchandising.
Mackwell says Golden Spike needs to ensure that the missions are worthwhile scientifically, otherwise the prestige in having Golden Spike do all the work is not so high. “If all you get is a taxi ride, the number of buyers will be very limited.” But Stern points out there were plenty of nations who lined up like a “stack of pancakes” to pay the Soviet Union for rides to the Salyut and Mir space stations in the 1980s and 1990s.
Golden Spike is one in a flurry of commercial space efforts underway that have been enabled in part by the cheaper access to space that companies like SpaceX could provide. In April, a company called Planetary Resources announced plans to mine asteroids. And in June, a private foundation called B612 announced plans to launch a space telescope to spot hazardous asteroids.

Tuesday, December 4, 2012


NATURE NEWS

Graphene towers promise 'flexi-electronics'

The 3D ‘monoliths’ — grown between forming ice crystals — add elasticity to the super-strength and conductivity of graphene sheets.
The graphene towers' honeycomb structure gives it super-strength and resilience.
L. QIU, MONASH UNIVERSITY
It can support 50,000 times its own weight, springs back into shape after being compressed by up to 80% and has a density much lower than most comparable metal-based materials. A new superelastic, three-dimensional form of graphene can even conduct electricity, paving the way for flexible electronics, researchers say.
The team, led by Dan Li, a materials engineer at Monash University in Clayton, Australia, coaxed 1-centimetre-high graphene blocks or 'monoliths' from tiny flakes of graphene oxide, using ice crystals as templates. The work is published today in Nature Communications1.
Graphene, a two-dimensional form of carbon that was first isolated less than a decade ago, has exceptional mechanical strength and electrical conductivity, but making use of these properties means first finding ways to scale up from nano-sized flakes (see ‘Graphene spun into metre-long fibres’).
Li and his colleagues adapted an industrial technique called freeze casting to do just that. This involves growing layers of an oxygen-coated, soluble version of graphene called graphene oxide between forming ice crystals. On cooling the aqueous solution of graphene oxide flakes, a thin layer of the nanomaterial becomes trapped between the growing crystals, forming a continuous network that retains its structure once the ice is thawed.

In the latest study, researchers show that by partially stripping the oxygen coating before freeze casting, they could enhance the bonding between adjacent flakes in the network, producing much stronger materials.Researchers have used this method before2, but the resulting material had poor mechanical strength — a property that Li attributes to the oxygen layer that coats each flake, which weakens bonding between neighbouring flakes in the network.        
After freeze casting, the honeycomb-like network held its shape as the ice was removed. The researchers could then chemically convert the graphene oxide into graphene, strengthening inter-sheet bonding, and so the material itself, still further.

Fill the void

Li attributes the new graphene's properties to its structure: the individual graphene sheets are neatly aligned, forming an ordered network of hexagonal pores.
2D graphene sheets have exceptional properties which researchers want to scale up from nano- dimensions.
THINKSTOCK
Rodney Ruoff, a researcher in graphene assemblies at the University of Texas at Austin, says that the material “is very interesting for the extremely low density that the researchers achieve, as well as its exceptional mechanics”. He adds that the structure could be used as a scaffold for flexible battery electrodes, or form the basis of many composite materials. “It would be interesting to fill the pores with rubber materials, for example,” he says. “There is a great interest in making rubber thermally or electrically conductive without harming its elastic properties.”
Li says that the superelastic graphene has potential for use in biomedical applications. “Biomaterials people are very interested in this structure because the pore sizes match existing tissue scaffolds very well,” he says