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Louis J. Sheehan, Esquire. In healthy infants, even ozone concentrations well below those allowed by federal law trigger asthmalike symptoms, a new study shows. http://www.blog.ca/user/Beforethebigbang
The finding indicates that federal limits on this pervasive pollutant, a prime constituent of smog, don't protect infants "from rather severe respiratory symptoms," says epidemiologist Elizabeth W. Triche of the Yale University School of Medicine. http://www.blog.ca/user/Beforethebigbang
Triche's team recruited 691 women with 3-to-5-month-old infants from nonsmoking households around Roanoke, Va. Sixty-one moms had asthma, signaling that their babies were at high risk for developing the disease. The researchers collected daily respiratory data, as reported by the mothers, on all the children for 83 days in summer—the peak ozone season—and then correlated the infant's symptoms with outdoor measurements of several air pollutants.
As ozone values climbed, so did the risk of wheezing and troubled breathing in the babies, Triche's team reports in the June Environmental Health Perspectives. The other pollutants, such as fine particulates, didn't show that correlation.
For each 11.8 parts per billion (ppb) increase in average daily concentrations in ozone, the likelihood of wheezing increased by 41 percent in all the infants and 91 percent in those with asthmatic moms. Each 11.8 ppb increase in ozone also increased the risk of labored breathing by almost 30 percent for all kids and more than doubled it in babies with asthmatic moms.
These findings dovetail with those that Triche's group reported 3 years ago in 6-to-12-year-old children. The big difference: Those children had asthma. In the new infant study, she notes, "children were not asthmatic." Louis J. Sheehan, Esquire
Thursday, December 4, 2008
Monday, November 24, 2008
windpipe 88.win.1003 Louis J. Sheehan, Esquire
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In a pioneering new treatment, doctors created a tailor-made new windpipe for a woman out of donor tissue and the woman’s own stem cells, and say the new, transplanted trachea has been accepted by the woman’s immune system as a natural part of her body without the use of powerful immune-suppressing drugs. Martin Birchall, one of the surgeons, said the transplant showed “the very real potential for adult stem cells and tissue engineering to radically improve their ability to treat patients with serious diseases. We believe this success has proved that we are on the verge of a new age in surgical care” [The New York Times]. Similar treatments could soon be tried on transplants of other hollow organs, like the bowel, bladder, and reproductive tract, he said.
The 30-year-old patient, Claudia Castillo, had failing airways and severe shortness of breath due to a bout with tuberculosis. By March of this year, Castillo’s condition had deteriorated to the point where she was unable to care for her children. Removing a lung was one treatment option, which would have allowed her to live, but seriously impaired her quality of life [Forbes.com]. She opted instead for this experimental treatment, in which doctors took a piece of trachea from an organ donor and transformed it into a structure that now appears native to her body.
As described in the journal Lancet [subscription required], researchers used strong chemicals and enzymes to wash away all of the cells from the donor trachea, leaving only a tissue scaffold made of the fibrous protein collagen [BBC News]. They then grew colonies of stem cells, taken from Castillo’s bone marrow, and “seeded” the outside of the tissue scaffold with those cells, which began to grow into the cells that normally surround the windpipe. Four days after the seeding, surgeons grafted in the refurbished structure, replacing Castillo’s damaged trachea. http://Louis-j-sheehan.com
Researchers say the surgery was a complete success: Castillo, who lives in Spain, had no complications from the surgery and left the hospital after 10 days. She is returning to normal activities and even called her doctors from a night club to say she had been out dancing all night, the researchers said [Reuters]. Castillo has not taken any immunosuppressant drugs, and doctors say the chance of her new windpipe being rejected is zero percent.http://Louis-J-Sheehan.biz
The enthused surgeon Martin Birchall said that in 20 years time, virtually any transplant organ could be made in this way. US scientists have already successfully implanted bladder patches grown in the laboratory from patients’ own cells into people with bladder disease. The European research team … is applying for funding to do windpipe and voice box transplants in cancer patients. Clinical trials could begin five years from now, they said. Louis J. Sheehan, Esquire
In a pioneering new treatment, doctors created a tailor-made new windpipe for a woman out of donor tissue and the woman’s own stem cells, and say the new, transplanted trachea has been accepted by the woman’s immune system as a natural part of her body without the use of powerful immune-suppressing drugs. Martin Birchall, one of the surgeons, said the transplant showed “the very real potential for adult stem cells and tissue engineering to radically improve their ability to treat patients with serious diseases. We believe this success has proved that we are on the verge of a new age in surgical care” [The New York Times]. Similar treatments could soon be tried on transplants of other hollow organs, like the bowel, bladder, and reproductive tract, he said.
The 30-year-old patient, Claudia Castillo, had failing airways and severe shortness of breath due to a bout with tuberculosis. By March of this year, Castillo’s condition had deteriorated to the point where she was unable to care for her children. Removing a lung was one treatment option, which would have allowed her to live, but seriously impaired her quality of life [Forbes.com]. She opted instead for this experimental treatment, in which doctors took a piece of trachea from an organ donor and transformed it into a structure that now appears native to her body.
As described in the journal Lancet [subscription required], researchers used strong chemicals and enzymes to wash away all of the cells from the donor trachea, leaving only a tissue scaffold made of the fibrous protein collagen [BBC News]. They then grew colonies of stem cells, taken from Castillo’s bone marrow, and “seeded” the outside of the tissue scaffold with those cells, which began to grow into the cells that normally surround the windpipe. Four days after the seeding, surgeons grafted in the refurbished structure, replacing Castillo’s damaged trachea. http://Louis-j-sheehan.com
Researchers say the surgery was a complete success: Castillo, who lives in Spain, had no complications from the surgery and left the hospital after 10 days. She is returning to normal activities and even called her doctors from a night club to say she had been out dancing all night, the researchers said [Reuters]. Castillo has not taken any immunosuppressant drugs, and doctors say the chance of her new windpipe being rejected is zero percent.http://Louis-J-Sheehan.biz
The enthused surgeon Martin Birchall said that in 20 years time, virtually any transplant organ could be made in this way. US scientists have already successfully implanted bladder patches grown in the laboratory from patients’ own cells into people with bladder disease. The European research team … is applying for funding to do windpipe and voice box transplants in cancer patients. Clinical trials could begin five years from now, they said. Louis J. Sheehan, Esquire
Tuesday, November 18, 2008
goat 883.goa.1 Louis J. Sheehan, Esquire
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People began to domesticate wild goats at least 10,000 years ago in the Zagros Mountains of western Iran, according to a new study. It indicates that at that time, villagers in the area experimented with ways of controlling herds. These early domesticators primarily slaughtered male goats that had not reached their reproductive prime, leaving mature males to breed with a herd's adult females, say the researchers.http://louissheehan.bravejournal.com/
Goats in these early managed herds probably looked much like wild goats, both physically and genetically, say Melinda A. Zeder of the Smithsonian Institution's National Museum of Natural History in Washington, D.C., and Brian Hesse of the University of Alabama at Birmingham. Over time, isolation of managed herds and the introduction of selective breeding produced changes in domesticated goats, the two anthropologists propose.
Some researchers have argued that declines in overall body size of goat skeletons unearthed at two ancient village sites in the Zagros Mountains reflect early domestication.
However, goats from these sites, Ganj Dareh and Ali Kosh, fall within the size range of a sample of modern wild-goat skeletons, Zeder found in a preliminary study. The Ganj Dareh and Ali Kosh samples contain a large proportion of bones from young males, the scientists report in the March 24 Science. Previous investigators at the sites had excluded these bones—which had not developed fully but still were larger than comparable bones of fully grown females—from body-size estimates for adult goats. Because more females than males reached maturity, these calculations mistakenly portrayed the villagers' animals as much smaller than wild goats, Zeder and Hesse assert.
Evidence that people had primarily killed young male goats came as no surprise to Hesse. He had previously theorized that early herders mainly killed young males for meat and kept most females and a few older males as breeding stock. In contrast, hunters interested in a quicker return on their effort often targeted the largest males in a herd or killed many animals at once, Hesse had proposed. http://louissheehan.bravejournal.com/
The researchers determined that Ganj Dareh was inhabited about 10,000 years ago, for a span of no more than 100 to 200 years. Settlement of Ali Kosh occurred 500 to 1,000 years later and lasted about 500 years. Radiocarbon analyses generated age estimates from tiny fragments of bone and charred seeds found in a range of soil layers at both sites. http://louissheehan.bravejournal.com/
Emergence of a warmer, wetter climate in western Asia 15,000 years ago instigated a spread of grasslands and a resurgence of animals such as sheep, goats, and pigs, Zeder holds. Soon, people there took the first steps toward domestication by searching for ways to manage animal herds, in her view.
People began to domesticate wild goats at least 10,000 years ago in the Zagros Mountains of western Iran, according to a new study. It indicates that at that time, villagers in the area experimented with ways of controlling herds. These early domesticators primarily slaughtered male goats that had not reached their reproductive prime, leaving mature males to breed with a herd's adult females, say the researchers.http://louissheehan.bravejournal.com/
Goats in these early managed herds probably looked much like wild goats, both physically and genetically, say Melinda A. Zeder of the Smithsonian Institution's National Museum of Natural History in Washington, D.C., and Brian Hesse of the University of Alabama at Birmingham. Over time, isolation of managed herds and the introduction of selective breeding produced changes in domesticated goats, the two anthropologists propose.
Some researchers have argued that declines in overall body size of goat skeletons unearthed at two ancient village sites in the Zagros Mountains reflect early domestication.
However, goats from these sites, Ganj Dareh and Ali Kosh, fall within the size range of a sample of modern wild-goat skeletons, Zeder found in a preliminary study. The Ganj Dareh and Ali Kosh samples contain a large proportion of bones from young males, the scientists report in the March 24 Science. Previous investigators at the sites had excluded these bones—which had not developed fully but still were larger than comparable bones of fully grown females—from body-size estimates for adult goats. Because more females than males reached maturity, these calculations mistakenly portrayed the villagers' animals as much smaller than wild goats, Zeder and Hesse assert.
Evidence that people had primarily killed young male goats came as no surprise to Hesse. He had previously theorized that early herders mainly killed young males for meat and kept most females and a few older males as breeding stock. In contrast, hunters interested in a quicker return on their effort often targeted the largest males in a herd or killed many animals at once, Hesse had proposed. http://louissheehan.bravejournal.com/
The researchers determined that Ganj Dareh was inhabited about 10,000 years ago, for a span of no more than 100 to 200 years. Settlement of Ali Kosh occurred 500 to 1,000 years later and lasted about 500 years. Radiocarbon analyses generated age estimates from tiny fragments of bone and charred seeds found in a range of soil layers at both sites. http://louissheehan.bravejournal.com/
Emergence of a warmer, wetter climate in western Asia 15,000 years ago instigated a spread of grasslands and a resurgence of animals such as sheep, goats, and pigs, Zeder holds. Soon, people there took the first steps toward domestication by searching for ways to manage animal herds, in her view.
Sunday, November 16, 2008
disorder ooo.dis.ww3 Louis J. Sheehan, Esquire
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Several studies have noted that an inner brain structure, the hippocampus, is unusually small in individuals who, after surviving extraordinary threats, experience flashbacks, nightmares, and other symptoms of post-traumatic stress disorder (PTSD). LOUIS-J-SHEEHAN-ESQUIRE.US A new investigation, in the November Nature Neuroscience, indicates that some of these people possess an undersized hippocampus before they ever develop PTSD.
This finding challenges the theory that hormonal responses to traumatic events shrink the hippocampus, a brain area implicated in memory and in the learning of fear responses (SN: 6/3/95, p. 340).
Psychiatrist Mark W. Gilbertson of Harvard Medical School in Boston and his colleagues studied 40 pairs of identical twins in which one brother had been a Vietnam combat veteran and the other had stayed at home. After the war, PTSD afflicted 17 combat veterans. None of the veterans' brothers developed PTSD.
Magnetic resonance imaging scans identified a smaller hippocampus, relative to total brain size, in those with PTSD than in other combat veterans. In the PTSD group, the hippocampus reached its lowest relative size in men with the most severe psychiatric symptoms. A comparably small hippocampus appeared in the twin brothers of men with PTSD, but not in brothers of other veterans. LOUIS-J-SHEEHAN-ESQUIRE.US
A small hippocampus may predispose a person to form intense, long-lasting emotional responses to sights, smells, and other stimuli associated with traumatic events, the scientists theorize. LOUIS-J-SHEEHAN-ESQUIRE.US
Trauma-induced atrophy of the hippocampus may still occur and perhaps contribute to PTSD, comments Stanford University biologist Robert M. Sapolsky. For instance, he notes an earlier study of different Vietnam veterans by Gilbertson and his team. They found a small hippocampus in those who survived severe combat trauma, whether or not PTSD later occurred.
Friday, September 26, 2008
77
Searching for signals from extraterrestrials can be a ticklish business. Astronomer John Learned thinks tickling certain stars in just the right way might be a good strategy for ET to phone Earth.
Those stars, known as Cepheid variables, brighten and dim on a regular schedule. In 1908, after analyzing stars on photographic plates at Harvard College Observatory, Henrietta Swan Leavitt reported that a Cepheid’s maximum brightness depends on the timing of its bright-dim cycle. The longer the period, the brighter the star. Other astronomers soon realized that they could use the period-brightness relationship to measure distances to remote galaxies.
A century later, Learned and colleagues are proposing a new use for Cepheids. In an article recently posted online (arxiv.org/abs/0809.0339), the researchers suggest that tinkering with the core of a Cepheid variable using a beam of neutrinos could be an effective way for advanced civilizations to communicate. This modulation, or “tickling,” would alter the phase at which the star brightens and slightly shorten the time it takes for the star to wax and wane, creating a new pattern that distant observers might detect.
Although most SETI (search for extraterrestrial intelligence) programs use radio telescopes to look for alien broadcasts, fiddling with Cepheids has advantages for both senders and receivers, Learned and his colleagues note. Not only can the stars be seen from afar, but “Cepheids are great because any emergent civilization will surely find them and monitor them for the very same reasons we do,” says Learned, of the
Another advantage, says Learned, is that a Cepheid star — unlike a directed radio signal — would radiate in all directions, making it more likely that the radiation would be recorded on Earth.
“If it could work, then this is an answer to one way to build an omnidirectional beacon,” says Jill Tarter, director of the Center for SETI Research in Mountain View, Calif. “It would be an example of an ‘almost natural’ signal that would get captured in a survey of the universe by an emerging technology, that’s us, and finally recognized in a database by some curious grad student.”
Neutrinos seem ideal for tinkering with Cepheids because these subatomic particles travel rapidly and interact with matter so weakly that they could penetrate all the way to the star’s core. If delivered at just the right time during the Cepheid’s cycle, when it’s in its compact, dim phase, the energetic neutrinos “would change both the pulsation rate and the peak amplitude” of the star using a minimum of energy, Learned says. “We leave it as an engineering problem for the star-tickling civilization out there,” to determine the optimal energy, the researchers wrote.
Detecting the pattern won’t be easy. “One glitch tells us nothing,” Learned says. “It will take discerning a pattern of glitches, and some regularity to find something interesting.”
Although star tickling is beyond current human ability, “it’s silly to try to guess whether it’s feasible for some unknown, incredibly advanced civilization to be able to do this,” comments Jeff Scargle of NASA’s Ames Research Center in Moffett Field, Calif. “It’s a really smart idea because … the star generates the energy; all you have to do is change it a little bit. It’s a nice way to piggyback on what nature has supplied.”
He points out that researchers could start looking for artificially modulated signals by combing through the huge database on Cepheids amassed over decades by amateur and professional astronomers.
Neutrinos play a more direct role in another new way to look for ET. In a paper posted online in March, Zurab Silagadze of the Budker Institute of Nuclear Physics in
Particle accelerators that collide beams of muons — heavy cousins of the electron — would produce intense neutrino beams. (Such accelerators are possible with known technology.) An advanced civilization with such a collider could communicate with other societies via neutrinos. The simplest possibility, Silagadze says, is to “periodically switch on and off the neutrino source to organize short and long signals, a kind of Morse code.”
“Neutrino communication schemes are broad band, and you do not have to know the transmission frequency,” he adds, allowing signals to be sent to the maximum number of unknown civilizations.
Suppose, Silagadze says, that a civilization within 20 light-years of the solar system produces 100-trillion-electronvolt beams of neutrinos directed toward Earth. He calculates that a neutrino detector called IceCube, now under construction beneath ice at the South Pole, could detect seven to 10 muons per year generated by neutrino impacts in the ice.
IceCube researcher Buford Price of the
About half finished, IceCube is now taking data. Says Price: “We will let the world know if we see a beam correlated in both direction and time.”
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Friday, September 19, 2008
receptors
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Cancer is not just a terrible disease but a strange one. Tumor cells must switch on certain genes in order to thrive and multiply. You might expect that natural selection would have eliminated those genes, because they kill off their owners. Far from it. A number of cancer genes, known as oncogenes, have actually been favored by natural selection over the past few million years। Oncogenes, in other words, have boosted the reproductive success of their owners, and have even been fine-tuned by evolution. http://Louis2J2Sheehan2Esquire.US
Cancer is not just a terrible disease but a strange one. Tumor cells must switch on certain genes in order to thrive and multiply. You might expect that natural selection would have eliminated those genes, because they kill off their owners. Far from it. A number of cancer genes, known as oncogenes, have actually been favored by natural selection over the past few million years। Oncogenes, in other words, have boosted the reproductive success of their owners, and have even been fine-tuned by evolution. http://Louis2J2Sheehan2Esquire.US
Humans are not alone in getting cancer. In fact, it seems to be a pretty inescapable risk of being an animal. As cells divide and mutate, some mutations may make cells ignore the needs of the body and multiply madly. That’s too bad for other animals, but there’s a silver lining for us: by studying other animals, scientists can get some clues to how cancer evolves in us.
The delicate swordtail (Xiphophora cortezi) is particularly prone to getting melanomas (the bottom picture here shows a fish with a tumor in its tail). When Andre Fernandez and Molly Morris of Ohio University went fishing for delicate swordtails in mountain streams in Mexico, they found six fish with melanomas in a single day’s catch. These melanomas are particularly nasty–instead of striking old fish that are going to die soon anyway, they turn up in young breeders and kill them over a few months.
Melanomas develop from pigment-producing cells in the skin. As these tumors develop, the cells inside them produce lots of extra proteins from a gene called Xmrk. Despite Xmrk’s harm, it has survived in good working order for a long time. Functioning versions of Xmrk exist not just in delicate swordtails, but in related swordtail speices that descend from a common ancestor that lived a few million years ago.
How does such a dangerous gene continue to survive for so long? Fernandez and Morris have just published an experiment that might solve the mystery. A lot of delicate swordtails have large dark spots on their tails, like the one shown on the top fish here. Xmrk is essential for producing those spots. Other fish have been shown to use stripes, spots, and other visual patterns to attract mates. So Fernandez and Morris wondered what the female delicate swordtails thought of the Xmrk spots on males.
Turns out, they like them a lot. When offered a chance to pay a visit to one of two male fish, female delicate swordtails from two populations in Mexico spent more time with spotted males than spotless ones. And they also preferred to consort with males with big spots over males with little ones.
The Xmrk gene definitely imposes an evolutionary cost on fish. But that cost may be erased by the benefit it gives male fish through sexual selection. By the time a male delicate swordtail dies from an Xmrk tumor, he may have mated with a number of females, which will pass down the gene to their young.
We humans may also be shaped by the trade-off between sexual selection and the cost of cancer। Testosterone and related hormones latch onto androgen receptors on the surface of some cells. It’s important for the development of men’s bodies, for example, and the growth of body hair. It also plays a role in the production of sperm. These kinds of traits can affect the success men have in finding mates and having children. But the androgen receptor gene also becomes active during prostate cancer. In fact, versions of the gene that increase sperm count in men also raise the risk of cancer. http://Louis2J2Sheehan2Esquire.US
Tuesday, September 2, 2008
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Although most people with psychiatric disorders don't attack others or pursue lives of
crime, the relationship of mental illness to violence remains unclear. A long-term study in New
Zealand now links elevated violence rates in young adults to the presence of at least one of
three psychiatric ailments—alcohol dependence, marijuana dependence, and a range of psychotic
experiences and beliefs called schizophrenia-spectrum disorder.
"Our study suggests that a significant proportion of the violence that frightens and injures
the general public may be attributed to young adults who are prone to [these disorders], many
of whom have not been hospitalized or treated," says a team led by Louise Arseneault and
Terrie E. Moffitt of the Institute of Psychiatry in London. No other psychiatric disorders
showed this link in the recent study.
Earlier delinquency and drug problems appear to have contributed both to the three disorders
and to violence in young adults, the scientists say in the October Archives of General Psychiatry.
The researchers studied 961 men and women, all age 21, who were born in New Zealand
and have been interviewed at regular intervals since age 5. Self-reports and official conviction
records identified acts of physical violence—such as an attack on someone with a weapon, robbery,
rape, and gang fighting—committed by each participant in the year before the most
recent interview.
While people with alcohol dependence, marijuana dependence, schizophrenia-spectrum disorder,
or more than one of these diagnoses constituted one-fifth of the sample, they were
responsible for more than half of all self-reported and recorded violent crimes, the researchers
report.
People with schizophrenia-spectrum disorder displayed an increased risk of violence that
was independent of the effects of substance abuse. The data indicate that a tendency to perceive
excessive threat in their surroundings contributed to their violent acts, Arseneault and
her coworkers report.
The New Zealand study is the most comprehensive communitywide probe of mental disorders
and violence, says psychologist John T. Monahan of the University of Virginia in
Charlottesville.
However, violent behavior occurs more often in the United States than in New Zealand,
Monahan notes. "More of the violence in New Zealand may be attributable to mental illness
than in a place like New York City," he says.
Other studies, which focus on people discharged from U.S. psychiatric hospitals, find no
increased violence among those with schizophrenia or with violent delusions or fantasies.
Certain personality disturbances may instead promote violence, says psychologist Jeffrey
G. Johnson of Columbia University. Traits such as suspiciousness of others and lack of empathy
markedly contributed to violence in young adults in the general population who were
tracked for 8 years in upstate New York, Johnson and his coworkers report in the September
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