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WASHINGTON, July 13 (Xinhua) -- Human neural stem cells are capable of helping people regain learning and memory abilities lost due to radiation treatment for brain tumors, a University of California, Irvine (UCI) study suggests.Research with rats found that stem cells transplanted two days after cranial irradiation restored cognitive function, as measured in one- and four-month assessments. In contrast, irradiated rats not treated with stem cells showed no cognitive improvement."Our findings provide solid evidence that such cells can be used to reverse radiation-induced damage of healthy tissue in the brain," said Charles Limoli, a UCI radiation oncology professor.Study results will appear Friday in Cancer Research, a journal of the American Association for Cancer Research.Radiotherapy for brain tumors is limited by how well the surrounding tissue tolerates it. Patients receiving radiation at effective levels suffer varying degrees of learning and memory loss that can adversely affect their quality of life."In almost every instance, people experience severe cognitive impairment that's progressive and debilitating," Limoli said. " Pediatric cancer patients can experience a drop of up to three IQ points per year."For the UCI study, multipotent human neural stem cells were transplanted into the brains of rats that had undergone radiation treatment. They migrated throughout the hippocampus -- a region known for the growth of new neurons -- and developed into brain cells.Researchers assessed the rats one month and four months after transplantation, noting enhanced learning and memory abilities at both intervals.Additionally, they found that transplanting as few as 100,000 human neural stem cells was sufficient to improve cognition after cranial irradiation. Of cells surviving the process, about 15 percent turned into new neurons, while another 45 percent became astrocytes and oligodendrocytes -- cells that support cerebral neurons.Most notably, Limoli said, he and his colleagues discovered that about 11 percent of the engrafted cells expressed a behaviorally induced marker of learning, indicating the functional integration of those cells into memory circuits in the hippocampus."This research suggests that stem cell therapies may one day be implemented in the clinic to provide relief to patients suffering from cognitive impairments incurred as a result of their cancer treatments," Limoli said.

THE HAGUE, June 1(Xinhua) -- Five people in the Netherlands have been sickened with an unusual strain of the E. coli bacteria, the institute for public health (RIVM) reported Wednesday.Of the five patients, four also suffered from intestinal problems and renal failure. The five who are infected all had recently been in Germany.The patients were infected with enterohaemorrhagic E.coli, or EHEC, a particularly deadly strain of the common bacteria found in the digestive systems of cows, humans and other mammals.The outbreak has hit at least eight European countries but virtually all of the sick people either live in Germany or recently traveled there.Medical authorities appeared no closer to discovering either the source of the infection or the mystery at the heart of the outbreak: why the unusual strain of the E. coli bacteria appears to be causing so many cases of hemolytic uremic syndrome, which attacks the kidneys and can cause seizures, strokes and comas.Earlier this week German researchers showed that Dutch cucumbers were not the cause of the contamination."It is essential to quickly find the source, as long as that is not found, the contamination can spread. It's a very aggressive bacteria and many people are seriously ill," a RIVM spokesman said.

WELLINGTON, July 26 (Xinhua) -- Children born early are less likely to develop serious behavioral problems than previously thought because previous studies may have relied too much on the opinions of "sensitive" parents, according to a controversial New Zealand research.The study by the Child Development Research Group at the University of Canterbury looked at the emotional and behavioral adjustment of children born very preterm (VPT).It showed that by age 6 children born very preterm (less than 33 weeks) were at an increased risk of emotional and attentional problems when compared with their full term peers, said a statement from the university.However, the findings suggested the risks may be lower than previous studies had suggested, because previous studies primarily relied on parents to provide information on their children's conditions, said lead author Samudragupta Bora."While parents are an important source of information about their child, it is also important to gather information from other significant people in the child's life such as their classroom teacher," said Bora.Bora and other members of the research team, found that parents reported higher rates of emotional and attention problems in their children than teachers did."Having a baby born prematurely is an extremely stressful experience for parents. During their baby's stay in the neonatal unit most parents will have been alerted to the possibility of their child developing problems such as behavioral difficulties in the future due to being born too early. Therefore, very understandably, many parents of these children are very sensitive to the possibility of developmental problems," he said."The use of multiple informants - parents, teachers and clinical observation - to assess VPT children's well-being is important to minimize the effects of report source bias and the over or under-identification of adjustment problems in children born VPT," said Bora."This is controversial because it shows that reliance on parents or teachers alone can lead to data validity issues."Although children born VPT were at higher risk of showing emotional and attentional problems, the risks of more severe problems were relatively modest, said Bora.The findings have been published the Journal of Paediatrics and Child Health.

WASHINGTON, June 2 (Xinhua) -- When humans see red, their reactions become both faster and more forceful, according to a new study published this week in the U.S. bimonthly journal Emotion.The findings may have applications for sporting and other activities in which a brief burst of strength and speed is needed, such as weightlifting. But the authors caution that the color energy boost is likely short-lived.The study measured the reactions of students in two experiments. In the first, 30 fourth-through-10th graders pinched and held open a metal clasp. Right before doing so, they read aloud their participant number written in either red or gray crayon. In the second experiment, 46 undergraduates squeezed a handgrip with their dominant hand as hard as possible when they read the word "squeeze" on a computer monitor. The word appeared on a red, blue, or gray background.In both scenarios, red significantly increased the force exerted, with participants in the red condition squeezing with greater maximum force than those in the gray or blue conditions. In the handgrip experiment, not only the amount of force, but also the immediacy of the reaction increased when red was present.The colors in the study were precisely equated in hue, brightness, and chroma (intensity) to insure that reactions were not attributable to these other qualities of color."Red enhances our physical reactions because it is seen as a danger cue," explains coauthor Andrew Elliot, professor of psychology at the University of Rochester and a lead researcher in the field of color psychology. "Humans flush when they are angry or preparing for attack," he explains. "People are acutely aware of such reddening in others and it's implications."But threat is a double-edged sword, argue Elliot and coauthor Henk Aarts, professor of psychology at Utrecht University, in the Netherlands. Along with mobilizing extra energy, "threat also evokes worry, task distraction, and self-preoccupation, all of which have been shown to tax mental resources," they write in the paper.In earlier color research, exposure to red has proven counterproductive for skilled motor and mental tasks: athletes competing against an opponent wearing red are more likely to lose and students exposed to red before a test perform worse.

SAN FRANCISCO, Sept. 2 (Xinhua) -- A late-season potato blight has been detected on farms in Alaska, only the fourth time the disease appear in the U.S. state since 1995, local media reported on Friday.The disease was found this week in the fields of potato producers in cities of Delta Junction and Palmer, according to the Fairbanks Daily News-Miner, Alaska's second largest daily newspaper.Farmers in both fields are working to prevent the spread of the blight, a fungus-like disease that can kill plants in the field or cause potatoes to rot in storage, the newspaper reported.Growers have been asked to kill all affected plants within 100 feet, and plant samples from both sites will be examined to identify what type of late blight is involved.Experts said that blight can be controlled through the use of fungicides, but the cool, damp weather this summer in the areas has created an ideal environment for the disease to spread.Although Alaska's potato crop is tiny compared to other U.S. states, it has been viewed as a possible global source of seed potatoes in recent years because it is largely free of disease.A local university has explored partnerships with Chinese growers to export certified seed potatoes, noted the Fairbanks Daily News-Miner report.

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