Science

NIAID MEDIA AVAILABILITY

Identified: Switch that Turns On the

Allergic Response in People

WHAT:		A new study in human cells has singled out a molecule that specifically directs immune cells to develop the capability to produce an allergic response. The signaling molecule, called thymic stromal lymphopoietin (TSLP), is key to the development of allergic diseases such as asthma, atopic dermatitis (eczema), and food allergy. The study team, led by Yong-Jun Liu, M.D., Ph.D., at the University of Texas M.D. Anderson Cancer Center, Houston, focused on dendritic cells, immune cells that initiate the primary immune response. Dendritic cells come into contact with other immune cells known as T cells, causing them to develop into different subsets of T cells, including helper 1 (Th1) and helper 2 (Th2) cells. These T-cell subsets are involved in protective immune responses, but the Th2 cells can also drive an allergic response. Until now, it was not known how dendritic cells induced T cells to become Th2 cells. The investigators used dendritic cells isolated from the blood of healthy donors and found that the binding of TSLP to these cells activates a distinct set of signaling pathways within the cells. As a result, the dendritic cells produce messenger molecules that act on the T cells, causing them to develop into Th2 cells. The study identifies TSLP as a switch that causes the development of the allergic response in people and suggests that this molecule may be a potential therapeutic target to treat and prevent allergic diseases. Dr. Liu and his colleagues are supported by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. The investigators are with the Asthma and Allergic Diseases Cooperative Research Centers program, now in its fourth decade of continuous funding as the cornerstone of NIAID’s asthma and allergy research portfolio.
ARTICLE:		K Arima et al. Distinct signal codes generate dendritic cell functional plasticity. Science Signaling. DOI: 10.1126/scisignal.2000567 (2010).
WHO:		Marshall Plaut, M.D., Chief, Allergic Mechanisms Section, Asthma, Allergy and Inflammation Branch, NIAID Division of Allergy, Immunology and Transplantation, is available to comment on this article.
http://humancells-dobi.blogspot.com/science

Science

New Study Examines Best Ways to Prevent Mother-to-Child HIV Transmission and Preserve Maternal and Infant Health

An estimated 430,000 children worldwide became infected with HIV in 2008, mostly through birth or breastfeeding from an HIV-infected mother. Many regions of the world are gaining increased access to complex antiretroviral drug regimens for preventing HIV transmission from a mother to her child. However, these strategies have not yet been directly compared with simpler antiretroviral drug regimens in terms of their safety, efficacy, feasibility and cost-effectiveness.

On January 15, a large, multinational clinical trial began to determine how best to reduce the risk of HIV transmission from infected pregnant women to their babies during pregnancy and breastfeeding while preserving the health of these children and their mothers.

The PROMISE (“Promoting Maternal-Infant Survival Everywhere”) study aims to enroll 7,950 HIV-infected women who are pregnant or have recently given birth and 5,950 HIV-exposed infants of these women. The participants will come from as many as 18 countries whose levels of resources range from high to low. The International Maternal Pediatric Adolescent AIDS Clinical Trials network is conducting the study with funding from the National Institute of Allergy and Infectious Diseases and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, both part of the National Institutes of Health. Led by protocol chair Mary Glenn Fowler, M.D., M.P.H., of the Makerere University–Johns Hopkins University Research Collaboration in Kampala, Uganda, the study team expects results in five to six years.

The HIV-infected women eligible to participate in PROMISE do not yet qualify for treatment—that is, their CD4+ T cell count, a measure of immune health, exceeds the level (350 cells per cubic millimeter of blood) at which highly active antiretroviral therapy (HAART) generally is recommended. HAART consists of a potent combination of three or more antiretroviral drugs.

The study addresses four distinct research questions. Most volunteers will participate in multiple components of the study to answer these questions. The first component will examine which of two proven strategies is safer and more effective at preventing mother-to-child HIV transmission before and during delivery: giving HIV-infected pregnant women a three-antiretroviral-drug regimen beginning as early as 14 weeks of gestation, or giving them the antiretroviral drug zidovudine beginning as early as 14 weeks of pregnancy and a single dose of the antiretroviral drug nevirapine during labor. The regimen of zidovudine and nevirapine is the standard of care in many countries for women who do not yet require treatment for their HIV infection. Some 4,400 women will be assigned at random to receive either one of these two interventions.

The second component of the PROMISE study will compare the safety and efficacy of two methods of preventing mother-to-child HIV transmission during breastfeeding. The study team will assign 4,650 mother-infant pairs at random either to receive a daily dose of infant nevirapine or to have the mothers take a three-antiretroviral-drug regimen throughout breastfeeding.

The third component of the PROMISE study will examine the effects of short-term use of a three-antiretroviral-drug regimen during pregnancy and breastfeeding to prevent mother-to-child HIV transmission on the health of HIV-infected mothers who do not yet need treatment. For such women, it remains unclear whether stopping the three-drug regimen after giving birth or ceasing to breastfeed would compromise their health. Although past studies have shown that interrupting treatment with antiretroviral drugs has a negative effect, the conditions in those studies are different enough from the conditions of the PROMISE study to make extrapolating the results difficult, according to the study investigators.

The 4,675 women participating in this third component of PROMISE will be assigned at random either to stop the three-antiretroviral-drug regimen after giving birth or weaning, or to continue the drug regimen indefinitely. The health of these two groups will be compared. In addition, the women who receive the time-limited three-drug regimen will be compared with the women who participated in the first component of PROMISE and did not receive the three-drug regimen, but rather took zidovudine during pregnancy and single-dose nevirapine during labor.

The last component of the PROMISE study involves protecting the health of HIV-exposed but uninfected infants. In resource-limited settings, it is standard to give the antibiotic cotrimoxazole once daily to infants exposed to HIV at birth until the infant has stopped breastfeeding and is known to be HIV-uninfected. While cotrimoxazole prophylaxis improves the survival rate of HIV-infected infants, it is not known whether continuing to administer the drug after weaning similarly would benefit HIV-exposed but uninfected children.

In this fourth component of the PROMISE study, nearly 2,290 HIV-exposed but uninfected, weaned infants under one year old will be assigned at random either to continue receiving cotrimoxazole or to receive a placebo through age 18 months. Neither the mothers of the infants nor the study team will know which infants are in which group. The study will determine whether continuing cotrimoxazole prophylaxis in HIV-exposed, uninfected infants from the time they stop breastfeeding through age 18 months decreases their risk of illness and death without causing side effects or generating bacterial resistance to cotrimoxizole.

http://HIV-exposed-dobi.blogspot.com/science

Science

Soy Infant Formula

Information

On December 18, an independent scientific panel that advises the National Toxicology Program released its evaluation of research on soy infant formula.

Over the next few months, the National Institute of Environmental Health Sciences (NIEHS) and the National Toxicology Program will review the outside panel's conclusions which expressed “minimal concern” for adverse development effects in infants fed soy infant formula.

In the meantime we know that some parents may have questions regarding soy infant formula. The best place parents can get advice about their child's specific nutritional needs is by speaking with their child’s health care provider.

General Information

• What is soy infant formula?
  Soy formula is an infant food made using soy protein and other components. It is fed to infants as a supplement or replacement for human milk or cow milk.

• Are infants affected differently than toddlers or adults who eat soy?
  An infant’s diet is virtually 100% milk and/or formula. Infants who are fed only soy formula, have a much higher soy exposure level than do toddlers or adults who consume a variety of foods and less soy as a percentage of their diets.

• What should concerned parents do?
  The best place parents can get advice about their child's specific nutritional needs is by speaking to their doctor.

• Are there alternatives to soy formula if infants cannot tolerate animal milk?
  According to the American Academy of Pediatrics (AAP), the alternatives are amino acid formulations. Amino acids are the building blocks of pure protein, and these formulas omit all the other ingredients that are components of animal milk.
  
  The AAP promotes the use of human milk as the ideal source of infant nutrition. The 2008 AAP revised clinical report states there are few indications for the use of soy protein-based formula in place of cow milk-based formula in infants. The only real indications for soy formula use are for infants with congenital galactosemia, for use by families who are strict vegans, or infants who are truly lactose intolerant.
  
  For more information, read AAP’s May 2008 statement on the Use of Soy Protein-Based Formulas in Infant Feeding.
  http://pediatrics.aappublications.org/cgi/content/full/121/5/1062

• What portion of U.S. infants consumes soy formula?
  Based on 2009 market data, sales of soy formula in the United States represent about 12 percent of the total dollar sales for infant formula – almost a 50 percent decrease from 1999.

Alternatives

• Breastfeeding is not only an alternative, but an important health choice with many benefits for mothers and babies.

• For more information on breastfeeding: http://www.womenshealth.gov/breastfeeding/index.cfm and http://www.cdc.gov/breastfeeding/index.htm

• Parents can also get advice from their doctor about alternatives to soy formula.

U.S. Department of Agriculture’s Women, Infant and Children’s Program (WIC)

• The USDA’s Women, Infant and Children’s (WIC) Program provides Federal grants to States for supplemental foods, health care referrals, and nutrition education for low-income pregnant, breastfeeding, and non-breastfeeding postpartum women, and to infants and children up to age five who are found to be at nutritional risk
  
• WIC promotes and supports breastfeeding as the optimal source of nutrition for infants.
• When breastfeeding is not an option for a woman, iron-fortified infant formula is provided as the next best source of nutrition for infants.
  
• For more information on WIC: http://www.fns.usda.gov/wic/

Conclusions of the Independent Panel’s Evaluation of Soy Infant Formula

• During December 16 – 18, 2009, a 14-member, independent, scientific panel reviewed and evaluated the available scientific data on the consumption of soy infant formula as a risk to human development and identified research needs and data gaps.
  
• The expert panel, whose role it is to advise the National Toxicology Program, was convened by the Department of Health and Human Services National Toxicology Program (NTP) and the Center for the Evaluation of Risks to Human Reproduction (CERHR) of the National Institute of Environmental Health Sciences (NIEHS).
  
• The expert panel expressed “minimal concern” for adverse development effects in infants fed soy infant formula.
  
• The National Toxicology Program will review the expert panel’s conclusions and solicit public comment. The NTP will use the expert panel report, public comments, and any new scientific literature deemed relevant to the evaluation to prepare its report. The NTP anticipates issuing its final report by early summer 2010.

http://scientific panel-dobi.blogspot.com/science

Science

Black Liver Cancer Patients Face Worst Odds

Study found they had lower survival rates than those of other races.

MONDAY, Jan. 25 (HealthDay News) -- Even though they receive equal treatment, black patients with liver cancer have lower survival rates than patients of other races, a new U.S. study finds.

Researchers analyzed data from 20,920 patients in the Surveillance, Epidemiology and End Results (SEER) registry who were diagnosed with liver cancer between 1973 and 2004. The researchers also examined data from 4,735 United Network for Organ Sharing (UNOS) liver cancer patients who had liver transplantation between 1987 and 2008.

Over time, survival for liver cancer patients in all racial, ethnic and income groups has improved due to advances in screening, diagnosis and treatment. Among patients in the SEER registry, black and low-income liver cancer patients had the poorest long-term survival. Compared to whites, black patients had a 15 percent increased risk of death, while Asians had a 13 percent reduced risk, the researchers found.

The study findings are published online Jan. 25 in the journal Cancer.

The reasons for the survival disparities aren't clear, but may be due to differences in patients' underlying disease and in access to appropriate care, study author Dr. Joseph Kim, of City of Hope in Duarte, Calif., said in a news release from the journal. But even when the researchers adjusted for the type of therapy received by patients, blacks did worse than patients of other races.

Among patients who had liver transplants, blacks had poorer survival than all other groups of patients. This shows that racial and ethnic survival disparities can't be explained by differences in access to care alone. Further investigation is needed to identify other factors, the researchers said.

http://liver cancer-dobi.blogspot.com/science

Science

Discrimination May Lead

to Smoking in Boys

Stress felt by minority teens can lead to unhealthy behaviors, researchers say.

FRIDAY, Jan. 22 (HealthDay News) -- Minority teen boys smoke more when they suffer discrimination, but that's not the case for minority teen girls, a U.S. study finds.

Perceived discrimination had no effect on smoking rates among minority girls aged 12 to 15 and was associated with lower rates of smoking among minority teen girls aged 16 to 19.

"Our findings in girls, especially in the older girls, really surprised us," study first author Dr. Sarah Wiehe, an assistant professor of pediatrics at the Indiana University School of Medicine, said in a news release from the school. "We do not know why older girls who perceived discrimination were less likely to smoke, but there may be a possibility that they perceived discrimination because they were pregnant and also that they did not smoke due to pregnancy."

The study included 2,561 black and Hispanic teens, aged 12 to 19, living in low-income households in Baltimore, Boston, Chicago, Los Angeles and New York. About 25 percent of the teens reported discrimination within the previous six months, and 12 percent said they'd smoked within the previous 30 days.

Increased smoking by boys who suffer higher levels of discrimination may be caused by increased stress from male-specific targeting by police and business, the study concluded.

"Boys and girls may experience discrimination differently due to where they spend their time and that may account for the differences in whether discrimination was associated with smoking," Wiehe said. "In other words, the context of discrimination matters. We need to be aware that discrimination is a public health problem for adolescents -- one related to major health issues like smoking -- and need to actively work to reduce these occurrences."

The study appears online and in the March print issue of the American Journal of Public Health.

http://smoking-dobi.blogspot.com//science

Science

Environment Crucial

to Boosting Child's

Reading Skills

While genes matter, teacher/parent input is key, researchers find.

FRIDAY, Jan. 22 (HealthDay News) -- Environment plays an important role in the growth of young children's reading skills, a new study finds.

"We certainly have to take more seriously genetic influences on learning, but children who come into school with poor reading skills can make strides with proper instruction," lead author Stephen Petrill, a professor of human development and family science at Ohio State University, said in a university news release.

"The findings support the need for sustained efforts to promote reading development in children that take both genetic and environmental influences into account," he added.

The study included 135 identical twins and 179 same-sex fraternal twins who were enrolled in kindergarten or grade 1, and their reading skills were assessed annually for the next two years. The researchers compared how the twins scored on the reading tests and then used a statistical analysis to determine how much genetics and environment influenced their progress.

Environmental factors included instruction in school, nutrition, how much the children were read to, and how they were cared for by their parents.

The researchers concluded that when children begin to read, both genetics and environment play a role in the development of skills, but to different degrees. In word and letter identification, environment explained about two-thirds of the test results, while genetics explained one-third. For vocabulary and sound awareness, genetics and environment had equal influence. Genetics accounted for 75 percent of results on reading speed tests, they noted.

However, when Petrill and colleagues measured the children's growth in reading skills, environment became a much more important influence. Environment is almost completely responsible for the growth of reading skills that are taught, such as words and letters, and 80 percent responsible for growth in awareness of sounds in reading.

"Regardless of where children start as far as reading skills, and the impact that genetics and environment had on their initial skills, we found that their environment had an impact on how fast or how slowly those reading skills developed," Petrill said in the news release.

The study findings are published in the online edition of the Journal of Child Psychology and Psychiatry.

http://reading skills-dobi.blogspot.com/science

Science

Adding Fish Oil to IV

May Speed Sepsis Recovery

Omega-3 fatty acids in the solution reduce inflammation, researchers note.

TUESDAY, Jan. 19 (HealthDay News) -- Adding fish oil to intravenous solutions proved beneficial for intensive care patients with the potentially lethal blood infection known as sepsis, a new study finds.

The study, published Jan. 19 in the journal Critical Care, compared 13 patients who received fish oil in the normal IV nutrient solution given to patients with sepsis, and 10 patients who received traditional solutions. The patients who received the fish oil had lower levels of inflammatory chemicals in their blood, achieved better lung function, and had a shorter hospital stay.

"This is the first study of this particular fish oil solution in septic patients in the ICU. The positive results are important since they indicate that the use of such an emulsion in this group of patients will improve clinical outcomes, in comparison with the standard mix," researcher Philip Calder, of the University of Southampton in England, said in a news release.

"Recently, there has been increased interest in the fat and oil component of vein-delivered nutrition, with the realization that it not only supplies energy and essential building blocks, but may also provide bioactive fatty acids," Calder said.

"Traditional solutions use soybean oil, which does not contain the omega-3 fatty acids contained in a fish oil that act to reduce inflammatory responses. In fact, soybean oil is rich in omega-6 acids that may actually promote inflammation in an excessive or unbalanced supply," he explained.

http://fish oil-dobi.blogspot.com/science

Science

Compulsive Dogs Yield

Clues to Human OCD, Autism

Repetitive flank-sucking in Dobermans and hand-washing in humans could share similar DNA, researchers say

By Amanda Gardner
HealthDay Reporter

TUESDAY, Jan. 19 (HealthDay News) -- A study of obsessive-compulsive Dobermans might someday help explain similar repetitive behaviors in humans.

Scientists have identified a region on chromosome 7 in obsessive-compulsive dogs that may correlate to the human version of the psychiatric disorder.

The gene is the same in humans, said Dr. Nicholas Dodman, first author of the study, which appears as a letter to the editor in the January issue of Nature Molecular Psychiatry. In humans it resides on chromosome 18, the same chromosome which holds all of the psychiatric genes identified thus far, he said.

"It's certainly true we have basically the same gene in us, so it's an intriguing lead, but there's a lot more work that has to be done to see if this particular finding is relevant to human health and obsessive compulsive disorder [OCD]," added Dr. Michael Slifer, an assistant professor of human genetics and genomics at the University of Miami Miller School of Medicine.

"But even if this particular finding is not directly relevant, it still gives us clues as to the pathways and processes that may be going on in humans as well as some possible targets for intervention and treatment," he added.

And, Slifer cautioned, "This gene probably does not have as robust an effect in humans as it does in dogs because we haven't found it yet in humans [in relation to OCD]. This one would have come out already. But that doesn't mean it might not still be relevant in a small subset [of people with OCD]."

Some 2 to 3 percent of humans suffer from OCD, marked by repetitive thoughts and behaviors, such as repeated hand-washing.

Canine compulsive disorder seems to affect certain breeds, notably bull terriers, which can have a tendency to maniacally chase their tails, and Dobermans, which will compulsively suck on blankets or on themselves.

"These are not just funny things," said Dodman, professor of clinical sciences at Tuft University's Cummings School of Veterinary Medicine in North Grafton, Mass. "It's a physically injurious and life-threatening disease and can seriously impair the relationship between owner and dog, which can lead to euthanasia."

"There [has been] no explanation for it and it's clearly genetically driven," added Dodman, who is also the author of several well-known animal behavior books.

Up to 70 percent of puppies in certain Doberman litters can be afflicted, he said. One German shepherd bit his tail so badly that he bled to death, he added.

"While we have known the flank-sucking in Dobermans had to have a genetic component because it occurred in certain bloodlines, this study confirms it and identifies where the trait is carried," said Bonnie Beaver, professor in the department of small animal clinical sciences at the College of Veterinary Medicine and Biomedical Sciences of Texas A&M University in College Station. "It provides a starting place to look at genetic relationships of other compulsive disorders and . . . might help the understanding of compulsive human disorders and be able to differentiate the genetic ones from the environmental ones."

Chromosome 7 appears within the cadherin-2 gene (CDH2), which is involved in communication among neurons in the brain.

And cadherins, proteins that enable cells to adhere or stick to each other, are also involved in human obsessive-compulsive disorders. Recently, cadherins were linked to autism spectrum disorder, also characterized by compulsive behaviors, such as repetitive head-banging.

The Tufts researchers teamed up with the Program in Medical Genetics at the University of Massachusetts and the Broad Institute at the Massachusetts Institute of Technology to test Doberman blood samples that the Tufts staff had collected and stored for more than a decade.

Dobermans who (in this case) compulsively sucked on their flanks or on blankets, were more likely to have this gene sequence than healthy dobermans.

Beaver said the findings were "exciting" and that "the number of dogs used in the study places good confidence levels on the findings."

http://Dobermans-dobi.blogspot.com/science

Science

Novice Poker Players

Don't Know When

to Walk Away

Analysis finds luck usually runs out for those who don't understand risk.

SATURDAY, Jan. 16 (HealthDay News) -- Play more online poker and you'll get better and win, right?

Wrong, says a new study of gambling behavior that suggests players -- especially beginners -- win less money the more hands they play.

The findings, which came from a study of 27 million online poker hands, suggest that small stakes translate to more wins, while playing longer means you'll lose, occasionally by a whole lot.

According to Cornell University sociology doctoral student Kyle Siler, the findings show that "people overweigh their frequent small gains vis-a-vis occasional large losses, and vice versa."

The study, released online in advance of publication in an upcoming print issue of the Journal of Gambling Studies, also reports that pairs of small-numbered cards -- from twos to sevens -- are more valuable than pairs of eights, nines, 10s and Jacks for small-stakes players.

"This is because small pairs have a less ambiguous value, and medium pairs are better hands but have more ambiguous values that small-stakes players apparently have trouble understanding," Siler said.

Siler, a poker player himself, analyzed hands of No-Limit Texas Hold'em. "Riskiness may be profitable, especially in higher-stakes games, but it also increases the variance and uncertainty in payoffs," he said. "Living one's life, calibrating multiple strategies and managing a bankroll is particularly challenging when enduring wild and erratic swings in short-term luck and results."

http://online poker-dobi.blogspot.com/science

Science

Girls' Soccer Injuries Plummet After Exercise Program

Specially designed training sessions bring less trauma to knees, researchers say.

FRIDAY, Jan. 15 (HealthDay News) -- A soccer-specific exercise program can help prevent injuries in young female players, says a new study.

The program features strengthening exercises aimed at improving motion patterns, to help reduce strain on the knee joint. The training sessions were integrated into regular soccer practices, and a seminar to increase awareness of injury risk was held for players, team leaders and parents.

The Swedish study included 777 girls, ages 13 to 19, from 48 teams that participated in the program, as well as a control group of 729 players from 49 teams.

Three knee injuries, including one non-contact injury (not involving another player), occurred in girls taking part in the program, compared with 13 knee injuries and 10 non-contact injuries among the players in the control group.

That means the program resulted in a 77 percent reduction in the incidence of knee injuries and a 90 percent reduction in the incidence of non-contact knee injuries, said Dr. Ashkan Kiani, of Uppsala Primary Care, Uppsala County Council and colleagues.

"The rate of injury was not only lower among teams participating in the preventive program but the injuries that did occur were also less severe," the study authors wrote. While all three injuries in the intervention group were major, all three players were fully active within six months. In the control group, most injuries were severe and only four of the 13 injured players were fully active within six months.

The study is published in the Jan. 11 issue of the journal Archives of Internal Medicine.

http://training sessions-dobi.blogspot.com/science

Science

Faster Heart Rate May Raise Risk of Heart Attack Death

But for women, exercise cuts that risk significantly, study finds.

TUESDAY, Jan. 12 (HealthDay News) -- For women under age 70, every 10-beat-per-minute increase in resting heart rate boosts the risk of dying from a heart attack by 18 percent, a new study has found.

Norwegian researchers tracked the health of about 50,000 healthy adults, aged 20 and older, for an average of 18 years. During that time, 6,033 men and 4,442 women died. Heart attack and stroke accounted for more than 58 percent of male deaths and more than 41 percent of deaths among women.

The higher a person's resting pulse, the greater their risk of death from cardiovascular disease, particularly from ischemic heart disease (heart attack and angina). Men with a pulse of 101 beats per minute or more were 73 percent more likely to die of ischemic heart disease than those with a rate of 61 to 72 beats per minute -- the normal healthy range.

Women with a resting heart rate of 101 beats per minute were 42 percent more likely to die of ischemic heart disease than those with a normal pulse. This was particularly true among women younger than 70 with a high resting heart rate -- they were more than twice as likely to die of a heart attack, the study found.

But the study also found that women with higher levels of physical activity had a lower risk of dying from ischemic heart disease, even if they had a high resting heart rate.

Physically inactive women with a resting heart rate of 88 beats per minute or higher were more than twice as likely to die of a heart attack than those with a lower heart rate. But women with a heart rate of 88 beats per minute or higher who did frequent and intensive exercise were only 37 percent more likely to die of a heart attack. However, this protective effect of exercise wasn't seen in men with high heart rates.

The study was published online Jan. 12 in advance of print publication in the Journal of Epidemiology and Community Health.

http://exercise cuts-dobi.blogspot.com/science

Science

Why You Eat for the Joy of It

A hunger hormone may drive the impulse to chow down even when full, researchers say.

MONDAY, Jan. 11 (HealthDay News) -- Why do people keep eating when they already feel full? New research in mice suggests it may have something to do with a hunger hormone that tells you to keep chowing down.

"What we show is that there may be situations where we are driven to seek out and eat very rewarding foods, even if we're full, for no other reason than our brain tells us to," Dr. Jeffrey Zigman, an assistant professor of internal medicine and psychiatry at the University of Texas Southwestern Medical Center and co-senior author of the new study, said in a news release from the school.

The researchers studied the hormones by experimenting with mice to determine whether they changed their food preferences after getting doses of the hormone, known as ghrelin.

In one experiment, mice who received ghrelin wanted to hang out in a room where they'd previously gotten high-fat food. Other mice weren't concerned about the room.

"We think the ghrelin prompted the mice to pursue the high-fat chow because they remembered how much they enjoyed it," study author Dr. Mario Perello, a postdoctoral researcher in internal medicine, said in the same news release. "It didn't matter that the room was now empty; they still associated it with something pleasurable."

According to the researchers, the brains of humans and mice handle pleasure in similar ways. They next want to figure out how the brain regulates the actions of the hormone.

The study appears online and in a future edition of the journal Biological Psychiatry..

http://research in mice-dobi.blogspot.com/science

Science

Power Really May Lead

to Moral Hypocrisy

As people reach the top, they become more critical of others, less critical of themselves, study finds.

SUNDAY, Jan. 10 (HealthDay News) -- Why do so many people in top positions fail to follow the ethical rules that they promote? New research suggests that power makes people more strict about other people's actions, but less strict about their own.

"According to our research, power and influence can cause a severe disconnect between public judgment and private behavior, and as a result, the powerful are stricter in their judgment of others while being more lenient toward their own actions," Adam Galinsky, co-author of the new study and the Morris and Alice Kaplan Professor of Ethics and Decision in Management at Northwestern University's Kellogg School, said in a news release from the Association for Psychological Science.

The study authors simulated the moral choices made by powerful people by assigning study participants to various roles. Some served as "prime minister" while others were "civil servants." The researchers then asked the participants to cope with moral questions related to issues regarding traffic rules, taxes and stolen property.

Various experiments showed that those with the most power were more hypocritical in their own behavior but stricter about judging others. Those who didn't feel they were entitled to their power were harder on themselves than others, a phenomenon the study authors called "hypercrisy."

"Ultimately, patterns of hypocrisy and hypercrisy perpetuate social inequality. The powerful impose rules and restraints on others while disregarding these restraints for themselves, whereas the powerless collaborate in reproducing social inequality because they don't feel the same entitlement," Galinsky explained.

The study will be published in an upcoming issue of the journal Psychological Science.

http://research suggests-dobi.blogspot.com/science

Sience

Coffee Cuts Liver

Scarring in Hepatitis C

Other sources of caffeine don't have same effect, study shows.

FRIDAY, Jan. 8 (HealthDay News) -- Caffeine in coffee reduces the severity of liver fibrosis in patients with chronic hepatitis C virus, a new study has found.

Liver fibrosis (scarring of the liver) is the second stage of liver disease during which liver function declines because of accumulated connective tissue.

The new U.S. National Institutes of Health study included 177 patients, mean age 51, whose daily consumption of caffeine from food and beverages was tracked for two years.

Patients who consumed more than 308 milligrams of caffeine from coffee per day had milder liver fibrosis than other patients. The daily amount of caffeine intake found to be beneficial is equivalent to 2.25 cups of regular coffee. For each 67-milligram increase in caffeine consumption (about one half cup of coffee), there was a 14 percent decrease in the odds of advanced fibrosis for patients with hepatitis C virus.

Other sources of caffeine -- such as soft drinks, tea, caffeine-fortified drinks and caffeine pills -- didn't have the same helpful effect, according to the study published in the January issue of the journal Hepatology.

The researchers said further research is needed to determine whether the protective effects of coffee/caffeine increase at levels beyond normal daily intake.

http://liver fibrosis-dobi.blogspot.com/science

Sience

Common Radio Frequency

Tag Readers Might Trouble

Pacemakers

Found in store security tags, hotel keycards, toll booth sensors, researchers say.

FRIDAY, Jan. 8 (HealthDay News) -- A new study from the U.S. Food and Drug Administration and pacemaker manufacturers confirms that emissions from readers of ubiquitous radio frequency identification devices (RFIDs) can interfere with pacemakers, although that risk is small.

RFID tags are tiny, cheap electronic identifiers found in store security tags, hotel room keycards, automated toll booth sensors and other devices. Electronic readers can spot and "read" the information in the tags.

The new study, published in the January issue of the HeartRhythm Journal, examined the vulnerability to RFID reader electromagnetic interference in 15 pacemakers and 15 implanted cardioverter-defibrillators (ICDs).

The researchers concluded that the devices could cause disturbances in pacemakers and ICDs at low frequencies. "While modern pacemakers and ICDs use filters to minimize susceptibility to higher-frequency signals, there is limited filtering of low-frequency signals due to the design constraints of both pacemakers and ICDs," the Heart Rhythm Society explained in a news release.

Studies conducted in the laboratory (the devices were not implanted) found that 67 percent of pacemakers and 47 percent of ICDs displayed some reaction to RFID readers. The risk for some sort of device reaction rose with the increasing proximity of the RFID reader to the pacemaker or ICD, the team noted.

Reactions included "pacing inhibition, inappropriate pacing, noise reversion mode, changed pacing rates, inappropriate delivery of antitachycardia pacing, inappropriate high-voltage shocks and device programming change," according to the Heart Rhythm Society. They noted that, so far, the FDA has not received any reports from patients and their doctors of electromagnetic interference linked to an RFID system.

"We do not believe the current situation reveals an urgent public health risk," study author Seth J. Seidman, a research electrical engineer for the FDA's Center for Devices of Radiological Health, said in a news release from the society. "However, we are concerned that the continued proliferation of RFID without taking electromagnetic interference into consideration could cause clinically significant events for patients."

The new study echoes a report published in 2008 in the Journal of the American Medical Association, in which Dutch researchers found that RFID devices might throw off medical equipment in hospitals.

http://pacemaker-dobi.blogspot.com/science

Science

Slim Risk of Death After Joint Replacement

Mortality risk highest within first 26 days after hip or knee surgery, study finds.

THURSDAY, Jan. 7 (HealthDay News) -- Patients who undergo knee or hip replacement surgery have a slightly increased risk of death for only 26 days after the procedure, claims a study that challenges earlier findings.

"Previous studies suggesting that increased mortality exists for as long as 60 or 90 days post hip or knee replacement surgery may be wrong. We believe the risk is tied to a much shorter duration," study author Stein Atle Lie, a professor in the surgical sciences department at the University of Bergen in Norway, said in a news release.

The researchers analyzed data on 81,856 Australian and Norwegian patients who underwent total knee replacement and 106,254 patients who had total hip replacement. The risk of death for 26 days after surgery was 0.1 percent. After that, the increased risk of death was negligible.

Male patients and those older than 70 had the highest risk of death within 26 days after knee or hip replacement, according to the study published in the January issue of the Journal of Bone and Joint Surgery.

"We conducted this study to help people contemplating hip or knee replacement. As with all surgeries, there is some increased risk of postoperative mortality. However, we were pleased to find the mortality rate is so minimal -- less than 1 percent -- following hip and knee replacements," Lie said.

http://knee surgery-dobi.blogspot.com/science

Science

Lower Vitamin D Levels

in Blacks May Up

Heart Risks

Darker skin reduces absorption of sunlight, researchers explain.

By Ed Edelson
HealthDay Reporter

WEDNESDAY, Jan. 6 (HealthDay News) -- New research indicates that the darker skin of blacks may increase their risk of heart disease and stroke because it reduces production of vitamin D, which is made during exposure to sunlight.

Several studies have associated low levels of vitamin D with an increased risk of cardiovascular disease and "the biggest source of vitamin D levels is sunlight," said Dr. Kevin Fiscella, a professor of family medicine and community and preventive medicine at the University of Rochester, and co-author of a paper in the January/February issue of the Annals of Family Medicine. "People with dark skin who live at higher latitudes, where the intensity of sunlight is less, may be at greater risk."

But the issue abounds with unanswered questions, starting with whether there is a real cause-and-effect relationship of vitamin D levels and cardiovascular risk, and ending with whether supplements that increase blood levels of the vitamin lower that risk, Fiscella said.

"We don't truly know the answer," Fiscella said. "That is the really pivotal question, what happens to cardiovascular risk if you correct blood levels of vitamin D. We do know that small supplements for middle-aged people don't seem to have any effect."

In the study, Fiscella and Dr. Peter Franks of the University of California, Davis, looked at data on more than 15,000 U.S. adults in a national nutritional study. They found that overall, the 25 percent of adults with the lowest levels of vitamin D had a 40 percent higher risk of cardiovascular death. When they singled out blacks, the report found a 38 percent higher incidence of such deaths than among whites. Most of that difference was related to lower levels of vitamin D.

"The first issue is clarifying whether vitamin D is truly an independent risk factor for cardiovascular disease," Fiscella said. There are reasons to believe that it is, since too-low levels of the vitamin are associated with development of high blood pressure, kidney disease and diabetes, he said, but the case is not proven.

A second issue concerns the proper level of intake of the vitamin. "A consensus is evolving that the current levels recommended are too low, and those with darker skin need higher levels," Fiscella said.

The current recommendation is a daily intake of 400 International Units (IUs) for most adults, and 600 IU for those over 70. Fiscella declined to make a recommendation.

There was no such hesitation on the part of Dr. James O'Keefe Jr., director of preventive cardiology at the Mid America Heart Institute in Kansas City, who has done his own studies of vitamin D and the heart.

"I recommend for most people 2,000 IU a day," O'Keefe said. "African-Americans probably need closer to 4,000 or 5,000."

Too few Americans have their vitamin D levels checked regularly, "so I tell people to get their vitamin D levels checked," O'Keefe said. "Three out of four Americans will need a vitamin D supplement."

While it hasn't been proven that raising vitamin D levels reduces cardiovascular risk, studies now underway will answer that question, O'Keefe said. Meanwhile, he said, "vitamin D supplements are very cheap" and it is difficult to overdose on the vitamin, although bone problems can develop with a daily intake of 10,000 or more IU, he said.

Fiscella is much more cautious. "I don't think we have great data on what happens at very high levels," he said. "If you recommend very high doses, some people will develop very high blood levels, and we don't have good enough data to say on the population level what the impact of very high levels would be."

http://vitamin d -dobi.blogspot.com/science

Science

Genetic Clues May

Point to Better Lymphoma

Treatments

Findings could help those with a type of non-Hodgkin's lymphoma, researchers say.

WEDNESDAY, Jan. 6 (HealthDay News) -- New research into the genetic causes of a form of non-Hodgkin's lymphoma could lead to novel treatments, suggest researchers from the U.S. National Institutes of Health.

Their new study reports on how lymphoma cancer cells manage to survive. The type of cancer in question, known as diffuse large B-cell lymphoma, develops in B cells, which are part of the immune system and help the body fend off attackers.

Diffuse large B-cell lymphoma accounts for about a third of newly diagnosed non-Hodgkin's lymphoma cases, the researchers noted in a news release from the U.S. National Cancer Institute.

The research, published Jan. 7 in Nature, pinpoints how signaling pathways work within lymphoma cells to allow them to survive. The researchers also explored genetic mutations that play a role in the process.

"This study opens up a wealth of therapeutic opportunities for this type of lymphoma and may eventually lead to clinical trials testing agents that target components of the B-cell receptor signaling pathway," the study's senior author, Dr. Louis M. Staudt, of the National Cancer Institute's Center for Cancer Research, said in the news release.

The researchers suggested that dasatinib, a drug that has been approved for treatment of chronic myelogenous leukemia, could turn off the signaling process.

http://research-dobi.blogspot.com/science

Science

Sinus Surgery

Brings Relief to Many

Study found 76% of sinusitis sufferers felt better afterwards.

By Amanda Gardner
HealthDay Reporter

FRIDAY, Jan. 1 (HealthDay News) -- Three-quarters of patients undergoing surgery for stubborn sinusitis saw significant improvements in their quality of life, new research shows.

Most of the remaining 25 percent also saw some improvement, just not as dramatic, said Dr. Timothy Smith, lead author of a study appearing in the January issue of Otolaryngology -- Head and Neck Surgery.

"Certainly this reinforces our belief that sinus surgery increases the quality of life of patients, and I see that clinically as well as scientifically," added Dr. Jordan S. Josephson, a sinus and allergy specialist at Lenox Hill Hospital in New York City. "Previous studies have been single-center studies, and this is a bigger study using multiple centers and using a fairly large population, so it further says sinus surgery is a really good thing to do if you need it."

Chronic rhinosinusitis (CRS) affects a sizable minority -- 14 percent to 16 percent -- of U.S. residents. The condition, marked by symptoms such as sinus pain and pressure, headache, stuffy nose and sneezing, can compromise quality of life more than even congestive heart failure, back pain or chronic obstructive pulmonary disease, the study authors said.

Endoscopic sinus surgery has been performed in the United States since the mid-1980s, said Smith, who is director of the Oregon Sinus Center at Oregon Health & Science University in Portland.

"It's a minimally invasive type of surgery performed with a telescope that goes into the nostril," then basically snips away abnormal and interfering tissue while leaving normal tissue behind, Smith explained.

Smith and his co-authors studied 302 patients with CRS from three academic medical centers, following them for an average of a year and a half after their surgery.

"These were patients who have chronic sinusitis so, by definition, they have at least three months of symptoms and they have evidence of an ongoing inflammation or infection of their nose and sinuses on either a CT scan or an examination of the nose and sinuses," Smith said.

Following the surgery, about 76 percent of patients had "clinically significant" improvement in quality of life, as measured by various validated scales.

Patients with worse disease at the outset seemed to fare the best after the procedure, as did those undergoing surgery for the first time. This second finding is probably explained by the fact that people going for second or further surgeries were probably sicker to begin with, Josephson said.

None of which is to say that patients shouldn't try medical therapies first, he added.

"I don't think it means everyone with CRS should consider surgery. They should try medical therapy, and if medical therapy fails and the surgeon feels that part of the problem is anatomic, then surgery would be a good tool for them to use," Josephson said. "Some people with stage 1 and 2 diseases may even get cured. This is a wonderful renewed hope of feeling better."

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Science

Procedure Boosts Outcomes

in Implantable Defibrillator

Patients

Catheter-based cardiac tissue clearing cuts recurrence of a dangerous heart arrhythmia, study finds.

THURSDAY, Dec. 31 (HealthDay News) -- Heart patients with a dangerous rapid heartbeat called ventricular tachycardia often get implantable cardiac defibrillators to help control the condition, and a new study suggests that they will have fewer recurrences of the abnormality if they undergo a procedure called catheter ablation before they receive the device.

Reporting Dec. 31 in The Lancet, researchers at Asklepios Klinik St. Georg in Hamburg, Germany, looked at 107 patients aged 18 to 80, all of whom had had a previous heart attack, an episode of stable ventricular tachycardia and reduced left-ventricular function.

Participants were assigned to receive implantable defibrillators either alone or along with catheter ablation, a procedure that destroys faulty tissue within the heart linked to irregular heartbeats.

The patients' outcomes were followed for an average of close to two years.

On average, patients went longer -- an average of 19 months versus six months -- without a recurrence of ventricular fibrillation or ventricular tachycardia if they had undergone ablation, the team found.

In a commentary accompanying the report, doctors at Brigham and Women's Hospital in Boston wrote that the study suggests "that ablation be considered early, in selected patients who are receiving an implantable cardioverter defibrillator for stable ventricular tachycardia, in whom recurrences of a ventricular tachycardia are likely." However, they added that "evidence of a positive effect on survival, subsequent hospital admissions, or quality of life is needed before this strategy can be recommended for routine use."

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