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Emergency room physicians can deliver clot-busting treatments to a wider range of stroke patients than previously thought, European researchers report in the Sept. 25 New England Journal of Medicine.

The finding could change the way stroke is treated and increase ER doctors’ ability to prevent some cases of disability caused by strokes, scientists say.

Most strokes result when a blood clot lodges in the brain, blocking blood flow to other parts of the organ. A powerful drug called tPA, or tissue plasminogen activator, can dissolve these clots. But medical dogma holds that it must be given within three hours of a stroke’s onset. Beyond that, the thinking goes, the bulk of the brain damage is done and adding the risk of internal bleeding that accompanies clot-busters seems unwise. The new study extends that window of effective tPA treatment by 90 minutes, to 4 ½ hours.

This precious extra time to dissolve a clot and restore blood flow to a starving portion of brain could benefit tens of thousands of stroke patients in the United States each year, says study coauthor Werner Hacke, a neurologist at the University of Heidelberg in Germany.

“I think this is big news because suddenly they have substantially extended the number of patients who get intravenous tPA,” says Scott Kasner, a neurologist at the University of Pennsylvania in Philadelphia.

However, many emergency room physicians are hesitant to give stroke patients clot-busting drugs at all. A landmark 1995 study found that giving the drugs within three hours of stroke onset provided benefits that outweighed the bleeding risk in most patients. But only about 4 percent of stroke patients who arrive at U.S. hospitals get tPA, says neurologist Patrick Lyden of the Veterans Affairs San Diego Medical Center and University of California, San Diego, who coauthored the 1995 report. Most stroke patients don’t receive tPA because the time of onset might be hazy, or doctors may be hesitant to risk incurring bleeding or are untrained in delivering tPA. The new data should clarify the time frame and allay some doubts about the treatment’s effectiveness, he says.

In the new study, Hacke and his colleagues identified patients who arrived at hospitals with a stroke that had begun more than three hours but less than 4 ½ hours earlier. The researchers used CT scans of the brain to rule out people with brain bleeding. The doctors also excluded those with severe strokes as indicated by the scans.

That left 730 patients, half of whom were then randomly assigned to get infusions of the tPA drug called alteplase. The others received a placebo.

After three months, roughly 52 percent of study patients treated with tPA within the extra 90 minute time window had normal daily function and were living independently, compared with 45 percent of those getting a placebo infusion. The death rate over three months was about 8 percent in both groups.

Doctors detected brain bleeding among treated patients about as often as seen in previous studies in which tPA was limited to a three hour window.

Time matters in stroke treatment, and delay is dangerous. As minutes or hours pass with a clot lodged in place, more brain tissue is starved of blood and damaged. Thus, busting a clot later into the stroke might rescue less tissue. “The [beneficial] effect of tPA decreases over time,” Hacke says.

Even so, treated patients in this study — who received tPA an average of four hours after the onset of stroke — still showed clear benefits over the placebo group.

“I think this will eventually be incorporated into clinical practice, slowly at first, and then become the standard of care,” Kasner says.

Stroke disables more adults than any other condition, yet every stroke is different. People who have a severe stroke are often rushed to a hospital with obvious problems, Hacke says. But those with milder strokes sometimes show up longer after a stroke’s onset, in part because they aren’t sure whether their symptoms are serious enough for a hospital visit, he says. These are the kinds of people most likely to benefit from the new study’s findings on delayed tPA treatment, he says.

Meanwhile, Lyden says, more hospitals need to grasp the value of tPA and have doctors on site or on call who can deliver it. “Every hospital needs to have a stroke plan,” he says. “Either have a way to give tPA, or set up a way to tell the EMS people to divert [an ambulance] to a place that can do it.”http://louis6j6sheehan.blogspot.com

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NASA has announced that in 2014 a new spacecraft called MAVEN will settle into orbit around Mars, and will get to work trying to solve the mystery inherent in the thin atmosphere of the Red Planet. Mars once had a much denser atmosphere which allowed liquid water to swill across its surface, but much of the former went awol “as part of a dramatic climate change.” Doug McCuistion, director of the Mars Exploration Program, said: “The loss of Mars’ atmosphere has been an ongoing mystery. MAVEN will help us solve it” [The Register].

The $485 million mission will be led by a team from the University of Colorado. MAVEN (which stands for Mars Atmosphere and Volatile EvolutioN mission), will be the second mission of the space agency’s Mars Scout program, a recent push by the agency for smaller, lower-cost spacecraft. The first, the Phoenix, was launched in 2007 and is operating on the surface of Mars [Denver Post].

Scientists are eager to study why Mars is such a dry and barren planet today, when geological evidence shows that it had a dense atmosphere billions of years ago that allowed for liquid water on its surface. Many planetary scientists believe the disappearance of Mars’ ancient magnetic field has been a significant factor in this. Maven will study current atmospheric “leakage”, looking closely at the role played by the charged particles streaming away from the Sun. Without the deflecting presence of a strong magnetic field, this “solar wind” will collide with atmospheric gases and slowly erode them into space [BBC News].

The planning process for the atmospheric mission has suffered through delays; NASA announced last December that a conflict of interest on the committee responsible for picking the winning team forced the agency to disband the committee and start over. That snag slowed down the entire project. The Mars Scout program had originally been scheduled for 2011 launch. But since Mars only comes close enough to Earth to launch probes every 26 months, NASA had to postpone the mission to 2013 [AP]. The science mission will also be shortened, from two years to one, because the probe will reach Mars later in the planet’s solar cycle, and after one year in orbit conditions will be less favorable for study। http://louis-j-sheehan.com

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Some people are inept at all things musical, whether it's playing an instrument or just recognizing a melody. Preliminary data suggest that these individuals' brains are, literally, out of tune.

Neuroscientists Krista L. Hyde and Isabelle Peretz, both of the University of Montreal, subjected 10 volunteers with these musical deficits to pitch shifts comparable to those that occur when someone plays one key and then the next key on a piano. None of the volunteers noticed a difference between the tones.

However, the same people—all of whom had great difficulty telling different melodies apart and remembering simple tunes—accurately tracked timed sequences of musical tones and noted slight changes in timing. Ten other volunteers with normal tone perception and musical aptitude also scored well on the timing test. This result indicates that it's pitch, not timing, that lies at the heart of severe musical ineptitude, sometimes referred to as amusia.

To Hyde and Peretz, the results suggest that the brain's capacity to perceive modest pitch changes may be impaired from birth in persons with amusia. As a result, such individuals never grasp the overall structure of musical passages.

बुइल्ड्स ००००३२१ लुईस जे. Sheehan

A new brain-imaging study indicates that a specially designed program for second and third graders deficient in reading boosts their reading skills while prodding their brains to respond to written material in the same way that the brains of good readers do. The same investigation found that the remedial instruction typically offered to poor readers in the nation's schools doesn't improve their skills and fails to ignite activity in brain areas that have been linked to effective reading.

"Good teaching can change the brain in a way that has the potential to benefit struggling readers," says pediatrician Sally Shaywitz of Yale University School of Medicine.

At least one in five U.S. grade-schoolers with average or above-average intelligence encounters severe difficulties in learning to read, researchers estimate. In 2000, a panel of educators and scientists convened by Congress concluded that reading disability stems primarily from difficulties in recognizing the correspondence between speech sounds and letters.http://louis2j2sheehan2esquire.us

Panel member Sally Shaywitz, along with Bennett A. Shaywitz, a neurologist also at Yale medical school, and their colleagues used that finding to design a brain-imaging investigation.

At the beginning and end of the school year, the investigators administered reading tests and functional magnetic resonance imaging scans to three groups of children, ages 6 to 9, attending school in New York or Connecticut. The brain scans were taken as each volunteer tried to identify written letters that matched spoken letters.

In one of the groups, 37 underachieving readers were given experimental tutoring that consisted of 50 minutes of daily, individual instruction in letters and combinations of letters that represent speech sounds called phonemes. The lessons also focused on development of fluency in reading words, oral reading of stories, and spelling.

Another 12 deficient readers received standard remedial reading and special education programs in their schools. These students didn't receive explicit instruction in learning to recognize how letters correspond to phonemes.

A third group, this one consisting of 28 good readers, received regular classroom instruction.

At the end of the school year, only poor readers in the experimental program showed marked gains in reading accuracy, speed, and comprehension, the researchers report in the May 1 Biological Psychiatry. Good readers still exhibited the strongest literacy, but the poor readers who received phonetically based instruction had closed the gap considerably.http://louis2j2sheehan2esquire.us

After poor readers completed the experimental program, their brains displayed pronounced activity in several of the same left-brain areas that are active when good readers do reading-related tasks. In an earlier study of poor readers, Sally Shaywitz and Bennett Shaywitz found that one of those neural regions remains inactive as these kids grow up. Preliminary evidence from other researchers indicates that this structure, located near the back of the brain, fosters immediate recognition of familiar written words and is thus crucial for fluent reading, Sally Shaywitz says.

Students who had completed the experimental tutoring program still displayed improved reading scores and associated left-brain activation when measured 1 year later.

Bruce D. McCandliss, a neuroscientist at Weill Medical College of Cornell University in New York City, calls the new report a "landmark study." It builds upon similar findings by other research teams that tracked much smaller numbers of poor readers given phonological instruction, he notes.

The Yale group now plans to study children who will be randomly assigned to different types of reading programs.