Scientific American

Stem Cells Help Heal Broken Hearts

Tue, 14 Feb 2012 19:19:08 EST

Valentine's Day can lead to plenty of broken hearts. But for cardiac wounds that time alone won't heal, science has made some major advances. When it comes to heart attack, for example, a big development is emerging from a tiny source. Stem cells are coming of age.

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Baby Monkeys with 6 Genomes Are Scientific First

Fri, 06 Jan 2012 19:00:00 EST

They look like ordinary baby rhesus macaques , but Hex, Roku and Chimero are the world's first chimeric monkeys, each with cells from the genomes of as many as six rhesus monkeys.

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November 2011 Advances Section Additional Resources

Fri, 11 Nov 2011 11:00:00 EST

The Advances section of Scientific American 's November issue took readers into the air with the world's highest flying geese, back in time with an unlikely ancestor, into space to rendezvous with some garbage, to the Internet for a new way of conducting clinical trials, and beyond. For readers interested in learning more about the developments described in this section, a list of further background material follows:

"On the Trail of Space Trash" [More]

You Say Embryo, I Say Parthenote

Fri, 04 Nov 2011 08:00:00 EST

U.S. stem cell scientists breathed a sigh of relief this July when a federal judge upheld the Obama administration’s expansion of stem cell research. He ruled that work on existing embryonic stem cell lines derived outside federally funded labs did not violate a ban on the destruction of embryos. Despite the legal victory, however, many investigators remain frustrated that a newer method for creating stem cells remains off-limits for funding.

Human embryonic stem cells typically come from fertilized eggs. In 2007, however, scientists at International Stem Cell, a California-based biotech firm, reported the first successful creation of human stem cell lines from unfertilized eggs. They used a process called parthenogenesis, in which researchers use chemicals to induce the egg to begin developing as if it had been fertilized. The egg--called a parthenote--behaves just like an embryo in the early stages of division. Because it contains no genetic material from a father, however, it cannot develop into a viable fetus.

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Mississippi to Vote on "Personhood" of Fertilized Eggs

Tue, 01 Nov 2011 15:20:00 EST

"When do you believe life begins?" Johnny DuPree, Democratic candidate for governor of Mississippi, asked during a public debate on October 14. The question was rhetorical, and DuPree's answer--not a surprise in one of the most socially conservative US states--was the same as that of his Republican opponent: "I believe life begins at conception." [More]

Preliminary Human Experiments to Test Safety of Nerve Cell Transplants for Spinal Cord Paralysis

Wed, 19 Oct 2011 12:25:00 EST

ROCKVILLE, Md.--A new experiment aimed at achieving actor Christopher Reeve's dream of finding an effective treatment for spinal paralysis was announced this week at an international meeting of scientists and people with spinal cord injury sponsored by the United 2 Fight Paralysis Foundation. The approach, which already is shown to be promising in animals and avoids the need for patients to take immunosuppressive drugs, has not yet been proved effective in humans. Nonetheless, patients are excited to see this advance as they have been frustrated waiting for the first human trials of the new approach.

W. Dalton Dietrich, scientific director of The Miami Project to Cure Paralysis at the University of Miami Miller School of Medicine, announced here that his research team has submitted an application to the U.S. Food and Drug Administration (FDA) for permission to begin new "phase I" experiments on humans to treat paralysis using the new cell transplantation technique. (Phase I trials have nothing to do with efficacy. They are only to test safety and typically a nontherapeutic dose is used at the outset of the safety studies.) With the new technique, rather than using cells derived from embryonic stem cells , the patient's own mature cells are harvested from a nerve in the leg and grown in large numbers in the laboratory, then transplanted back into the injured spinal cord to repair damage. This approach avoids the problems of immunological rejection and the controversy that can arise from using cells derived from embryonic stem cells for treating neurological injury and disease. Typically, patients receiving an organ or tissue transplant from a donor must be given immunosupressant drugs to prevent their immune systems from attacking the foreign tissue.

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10 Unsolved Mysteries in Chemistry (preview)

Mon, 10 Oct 2011 07:05:00 EST

1 How Did Life Begin? The moment when the first living beings arose from inanimate matter almost four billion years ago is still shrouded in mystery. How did relatively simple molecules in the primordial broth give rise to more and more complex compounds? And how did some of those compounds begin to process energy and replicate (two of the defining characteristics of life)? At the molecular level, all of those steps are, of course, chemical reactions, which makes the question of how life began one of chemistry.

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Could Stem Cells Rescue an Endangered Species?

Mon, 05 Sep 2011 15:10:00 EST

From Nature magazine

Fatu, a female northern white rhinoceros who lives in a Kenyan conservation park, is one of just seven of her kind left in the world. But millions of her stem cells, stored in a freezer in California, might one day help boost her population's ranks. [More]

Endurance Exercise Has Stem Cells Make Bone over Fat

Fri, 02 Sep 2011 15:28:08 EST

Hi. I’m running. I’m also telling some of my stem cells what to do right now. Well, I probably am, based on a new study with mice.

We have what are called mesenchymal stem cells. This type of stem cell goes on to become either fat or bone. Researchers found out that endurance exercise triggers the stem cells to preferentially mature into bone. And having more bone cells means improved blood production, which means a higher oxygen carrying capacity, and better immune reaction and better wound clotting. The research appears in the Journal of the Federation of American Societies for Experimental Biolog y, commonly known as the FASEB Journal . [J. M. Baker, Michael De Lisio and Gianni Parise, " Endurance exercise training promotes medullary hematopoiesis "]

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Studying Mental Illness in a Dish

Tue, 09 Aug 2011 07:00:00 EST

No organ in the human body is as resistant to study as the brain. Whereas researchers can examine living cells from the liver, lung and heart, taking a biopsy of the brain is, for many reasons, more problematic.

The inability to watch living human brain cells in action has hampered scientists in their efforts to understand psychiatric disorders. But researchers have identified a promising new approach that may revolutionize the study and treatment of conditions such as schizophrenia, autism and bipolar disorder. A team led by researchers at the Salk Institute for Biological Studies in La Jolla, Calif., took skin cells from a patient with schizophrenia, turned them into adult stem cells and then grew those stem cells into neurons. The resulting tangle of brain cells gave neuroscientists their first real-time glimpse of human schizophrenia at the cellular level. Another team, from Stanford University, converted human skin cells directly into neurons without first stopping at the stem cell stage, potentially making the process more efficient. The groups published their results recently in Nature ( Scientific American is part of Nature Publishing Group).

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How Do Tumors Grow?

Thu, 04 Aug 2011 08:00:00 EST

On a sweltering August evening in 2009 Pat Elliott noticed that her feet seemed swollen. Because she had been standing for hours while teaching a workshop in Phoenix, she was not surprised. “I thought it was the heat,” she says. But her feet hurt, too, so Elliott decided to play it safe and called her doctor, who suggested she come in for some tests. Days later the marketing professional learned that she had developed an uncommon form of blood cancer called chronic myelogenous leukemia (CML).

Elliott’s cancer is the result of a genetic change that arose in one or more stem cells in her bone marrow. (Normally these stem cells give rise to various blood cells in the body.) The defect caused the stem cells and their progeny to produce an abnormal enzyme known as Bcr-Abl. This enzyme signals the marrow to produce too many immature white blood cells and allows them to persist longer than they should. The proliferating blood cells then crowd out healthy cells, damage the bone marrow and allow infections to take hold. Once these abnormal cells enter the bloodstream, they can also cause the spleen to swell and damage other organs. The pain and swelling in Elliott’s feet most likely resulted from kidney problems caused by her disease. CML usually starts off being fairly innocuous, especially if treated. It can, however, become aggressive and lethal if left untreated.

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Skirting Steak: The Case for Artificial Meat

Tue, 17 May 2011 17:39:08 EST

Journalist Jeffrey Bartholet talks about his June Scientific American magazine article on the attempts to grow meat in the lab, and Editor in Chief Mariette DiChristina talks about the cover piece in the May issue on radical energy solutions. Web sites related to this episode include "Inside The Meat Lab " and "7 Radical Energy Solutions".

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When Will Scientists Grow Meat in a Petri Dish?

Tue, 17 May 2011 08:00:00 EST

Editor's note: This article appears in print with the title "Inside the Meat Lab."

It is not unusual for visionaries to be impassioned, if not fanatical, and Willem van Eelen is no exception. At 87, van Eelen can look back on an extraordinary life. He was born in Indonesia when it was under Dutch control, the son of a doctor who ran a leper colony. As a teenager, he fought the Japanese in World War II and spent several years in prisoner-of-war camps. The Japanese guards used prisoners as slave labor and starved them. “If one of the stray dogs was stupid enough to go over the wire, the prisoners would jump on it, tear it apart and eat it raw,” van Eelen recalls. “If you looked at my stomach then, you saw my spine. I was already dead.” The experience triggered a lifelong obsession with food, nutrition and the science of survival.

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