Scientists looking for easier and less-controversial alternatives to stem cells from human embryos said they found a potential source in placentas saved during childbirth, according to Reuters.
They described primitive cells found in a part of the placenta called the amnion, which they coaxed into forming a variety of cell types and which look very similar to sought-after embryonic stem cells.
With 4 million children born in the United States each year, placentas could provide a ready source of the cells, the team at the University of Pittsburgh said.
It is not yet certain that the cells they found are true stem cells, said Stephen Strom, who worked on the study. But they carry two important genes, called Oct 4 and nanog, which so far have only been seen on embryonic stem cells.
“We were just blown away when we found those two genes expressed in those cells,“ Strom said in a telephone interview.
“The presence of these two genes suggests these cells are pluripotent, which means they should be able to form any cell type in the body.“
Stem cells are the body’s master cells. So-called adult stem cells are found in the tissue and blood are a source for renewing cells.
Embryonic stem cells are found in days-old embryos. While powerful, their use is controversial because some people, President Bush among them, believe destroying an embryo is immoral and unethical.
Supporters of embryonic stem-cell research say it may provide an important path to a new field called regenerative medicine, in which diseases ranging from juvenile diabetes to paralysis could be cured using transplants of carefully cultivated stem cells.
There are moves in Congress to expand funding of embryonic stem cell research, in case it proves to be the best way forward, but also counter-measures to further restrict it.

The Sun (shown here) may have met its match in Serpens, home of the 8th-magnitude star HD 143436.

A far-off star may be the Sun’s close cousin.
A dim yellow star in the constellation Serpens may be nearly identical to the Sun, say astronomers in South Carolina and Hawaii. The star could, therefore, host a life-bearing planet like Earth.
According to astronomy.com, in 1997, astronomers in Brazil identified a solar twin in Scorpius named 18 Scorpii. The star’s properties--mass, age, spectral type, temperature, luminosity, and iron abundance--nearly match the Sun’s. Solar twins are especially interesting to astronomers who search for extraterrestrial intelligence.
Now, Jeremy King and Simon Schuler, both of Clemson University, and Ann Boesgaard of the University of Hawaii have found a star that may be just as good a solar twin as 18 Scorpii. Named HD 143436, the star shines at 8th magnitude, bright enough to see with binoculars. It is 140 light-years from Earth, located in Serpens Caput, the western section of Serpens.
King and his colleagues obtained high-resolution spectra of HD 143436 by using the Keck I Telescope in Hawaii. The star is spectral type G0, similar to the Sun’s spectral type of G2. Its absolute magnitude is 4.87 ± 0.10. This is almost the same as the Sun’s, which is 4.83. Thus, both stars emit nearly the same amount of light into space.
King’s team finds HD 143436 to be just as hot as the Sun: Its temperature is 5,768 ± 43 Kelvin, versus the Sun’s 5,777 K. Furthermore, the star’s mass is 1.01 ± 0.02 solar masses, and it has the same amount of iron as the Sun.
No one has yet discovered planets around HD 143436. But if HD 143436 has astronomers, they would see our Sun as an 8th-magnitude star in northern Eridanus.
King’s team does note one difference: The light element lithium is 6 times more abundant on HD 143436 than on the Sun. However, 18 Scorpii’s lithium level is also high--it is 4 times the Sun’s. In addition, HD 143436 may have less oxygen than the Sun.
To reduce the uncertainties, King’s team urges astronomers to study HD 143436 further, saying it “appears to hold great promise as a solar twin candidate.“ Until now, however, astronomers have neglected the star. A Google Internet search on “HD 143436“ currently turns up nothing, and a search on the star’s alternate name, HIP 78399, produces only one web page.

Women’s heart health may benefit more from hugs than men’s, a study suggests.
According to BBC News website, a team from the University of North Carolina studied the effects of hugging on both partners in 38 couples.
The study showed hugs increased levels of oxytocin, a “bonding“ hormone, and reduced blood pressure--which cut the risk of heart disease.
But, writing in the Psychosomatic Medicine, the researchers said women recorded greater reductions in blood pressure than men after their hugs.
During the study, the men and women were taken to separate rooms to test their blood pressure and levels of oxytocin, which is released during childbirth and breastfeeding, and cortisol, a stress hormone.
The couples were then reunited and asked to sit together and talk about a time when they were particularly happy.
Next, the couples were asked to hug for 20 seconds.
Both men and women were seen to have higher levels of oxytocin after the hug.
People in loving relationships were found to have higher levels of the hormone than others.
But the study also found all women had reduced levels of cortisol following the hug, as well as reporting the blood pressure benefits.
The researchers, led by psychologist Dr. Karen Grewen, wrote in Psychosomatic Medicine, “Greater partner support is linked to higher oxytocin levels for both men and women.
However, the importance of oxytocin and its potentially cardioprotective effects may be greater for women.

Rats that are fed a high-fat diet appear to lose their sensitivity to a hormone that tells the body when it’s had enough to eat--and the same could be true of humans, according to Reuters.
In experiments with rats fed either a high- or low-fat diet, researchers at Pennsylvania State University found that the fatty diet diminished the rodents’ sensitivity to a hormone called cholecystokinin, or CCK.
CCK is secreted by the small intestine to aid in the digestion of fat and protein. It is also one of the “satiety signals“ that the body produces to tell the brain that it’s time to stop eating.
In the new study, rats on a low-fat diet stopped eating a fat-filled treat when the researchers gave them a dose of CCK. Not so of the animals on the high-fat diet, who ended up eating far more of the fatty snack.
The findings suggest that consistently eating high-fat foods can desensitize the body to CCK’s signal to stop eating, according to Dr. Mihai Covasa, an assistant professor of nutritional sciences at the Penn State campus in University Park.
There is reason to believe that the findings in rats translate to humans, Covasa told Reuters Health. He pointed to a study that found that people who followed a high-fat diet for 2 weeks gradually became less satisfied from eating fatty fare--suggesting that, in the real world, they would have started eating more.
Covasa and colleague David M. Savastano report their findings in the August issue of the Journal of Nutrition.
Rats in the study were maintained on either a high-fat or low-fat diet for 3 weeks. When they were then tempted with a fatty snack, the animals that had lived on the high-fat diet ate more of the treat than those on the low-fat diet. And when the researchers injected the animals with CCK, they found that the hormone suppressed the low-fat group’s appetite over the next hour, but not that of the high-fat group.
The findings, Covasa said, underscore the importance of minding one’s fat intake, and of fitting a variety of foods and nutrients into the diet.
“You should watch how much you eat,“ he noted, “but the composition of what you eat is important too.“

Meteor impacts are often regarded as killers and the cause of mass extinctions on Earth, but researchers say meteors might have helped early life.
According to Science Daily, Canadian geologists reported Monday there’s a chance the heavy bombardment of Earth by meteors during the planet’s youth actually spurred early life on our planet.
A study of the Haughton Impact Crater on Devon Island, in the Canadian Arctic, has revealed some very life-friendly features at ground zero, researchers said. Those include hydrothermal systems, blasted rocks that are easier for microbes to inhabit, plus a protected basin created by the crater itself.
If the theory is correct, the scientists say impact craters could represent some of the best sites to look for signs of past or present life on Mars

Physicists at the University of Texas at Austin have discovered a new technique for cooling atoms and molecules that will allow them to study quantum physics more effectively with a greater variety of particles.
The researchers have found a way to use lasers to form walls that allow atoms and molecules to pass through in one direction, but do not allow them to return.
The technique could lead to advances in atomic clocks, which are used to standardize time worldwide.
Dr. Mark Raizen of the Center for Nonlinear Dynamics and his colleagues describe the one-way wall technique in Physical Review Letters and Europhysics Letters published earlier this year.
Raizen and his colleagues show that atoms and molecules can first be trapped in a box whose walls are built of laser light. The box can then be separated with an optical wall constructed of two lasers. These two lasers work in concert to allow atoms and molecules to pass through to one side of the box but block them from getting back to the other side. The box then has two distinct spaces, one filled with particles and one void of particles.
Raizen’s one-way wall extends the capabilities of laser and evaporative cooling, which have been limited to cooling a small number of atoms in the periodic table. The new method is applicable to a greater diversity of atoms and molecules and can expand the capability of researchers to test laws of quantum physics at extremely low temperatures.
Cells regulate the flow of ions through one-way channels in order to create osmotic pressure. Raizen and his colleagues illustrate it is possible to create a manmade barrier to such atomic movement.
With no increase in kinetic energy comes no increase in heat. By expanding and contracting the space that holds the trapped atoms and molecules, the temperature of this space, which Raizen calls a “quantum refrigerator,“ can be lowered until it reaches very close to Absolute Zero.
It’s at these ultra cold temperatures, -459 degrees Fahrenheit, that quantum physicists can manipulate atoms and molecules.