Sunday, January 31, 2010
Despite the common association of "right" with life, correctness, positiveness and good things, and "left" with death, clumsiness, negativity and bad things, recent research show that most left-handed people hold the opposite association. Thus, left-handers become an interesting case in which conceptual associations as a result of a sensory-motor experience, and conceptual associations that rely on linguistic and cultural norms, are contradictory.
These are the conclusions derived from various studies compiled by professor Julio Santiago de Torres, from the Department of Experimental Psychology and Behavioural Physiology at the University of Granada, who has conducted a bibliographic review on the subject, published in Ciencia Cognitiva: Revista Electrónica de Divulgación.
One of the latest works on this subject was undertaken by researcher Daniel Casasanto (Stanford University), who found out that left-handers tend to associate the left with nice and good things and the right with ugly and bad things, which goes against the enormous power of cultural context in which they live and the language they use.
Good things and bad things
In one of his experiments, Casasanto presented participants a diagram that depicts a character who was planning a trip to the zoo, and who loves zebras and thinks they are good, but dislikes pandas and thinks they are bad. The participant had to draw a zebra in the box that best represented good things and a panda in the box that best represented bad things.
Most of right-handed people located good things in the box on the right while left-handers placed them in the box on the left. Interestingly, only 14% of participants thought that his election had to do with what his dominant hand was.
Then, to see whether the left or right location could affect rating dimensions on abstract personality, he asked another group of participants to rate pairs of objects depicted in another drawing, indicating which of the two seemed more intelligent, more honest, more attractive and happier. And in a final experiment, participants were asked to assess which candidate would they chose for a job, or what product would they buy in a store.
In all tasks, right-handers tended to evaluate the object on the right better, while left-handers favoured the one on the left. Therefore, UGR professor says, "these results demonstrate that perceptuomotor experiences, in this case the greater ease and fluidity of interaction with one or another side of space, are sufficient to generate stable associations between specific dimensions, such as space, and concepts of a high degree of abstraction, such as kindness, intelligence or honesty."
These data provide one of the first clear demonstrations that sensory-motor experience can exert a powerful influence on the conceptualization of even our most abstract ideas.
A wrong world
As professor Santiago explains, "a left-handed person has often the feeling of having been born in a wrong world. From scissors to computer keyboards designs, everything is projected for right-handers. The fact that left-handed people are able to adapt quite well to these manual controls that are contrary to their nature, indicates a first interesting fact that it is often overlooked: undoubtedly, there is a difference in motor ability between the dominant and the non-dominant hand, but it is far from being a great difference."
In fact, the researcher points out, "speed and accuracy differences between the right and the left hand that are usually found, do not go beyond 10%. In addition, the left hand can be trained to high levels of implementation, as in the case of musicians or typists. In contrast with the intensive use of the right hand that characterizes an average right-handed person in over 90% of the tasks.
Julio Santiago recalls in his article that association between right and left with the symbolic systems of the world cultures "is deep, and reaches almost every aspect of life. Thus, right and left are respectively associated with aristocratic and common people, male and female, sacred and profane, good and bad. Eventually, these partnerships control aspects of life as varied as the position in which dead are buried, distribution of space in homes and churches, positions in which men and women sit at the table or in the temple and the hand chosen for saluting, swearing, eating or bathing."
Moreover, Santiago points out, "even vocabulary is also full of similar facts such as, for example, the word "siniestro," which derives from sinister, "izquierda" in Latin.
Young women and teenage girls often face efforts by male partners to sabotage birth control or coerce pregnancy -- including damaging condoms and destroying contraceptives -- and these efforts, defined as "reproductive coercion," frequently are associated with physical or sexual violence, a study by a team of researchers led by UC Davis has found.
Published online in the January issue of the journal Contraception, the study, "Pregnancy Coercion, Intimate Partner Violence and Unintended Pregnancy," also found that among women who experienced both reproductive coercion and partner violence, the risk of unintended pregnancy doubled. The study is the first quantitative examination of the relationship between intimate partner violence, reproductive coercion and unintended pregnancy, the authors say.
"This study highlights an under-recognized phenomenon where male partners actively attempt to promote pregnancy against the will of their female partners," said lead study author Elizabeth Miller, an assistant professor of pediatrics in the UC Davis School of Medicine and a practitioner at UC Davis Children's Hospital. "Not only is reproductive coercion associated with violence from male partners, but when women report experiencing both reproductive coercion and partner violence, the risk for unintended pregnancy increases significantly."
Conducted between August 2008 and March 2009 at five reproductive health clinics in Northern California, the study involved approximately 1,300 English- and Spanish-speaking 16- to 29-year-old women who agreed to respond to a computerized survey about their experiences with relationships and pregnancy.
Study participants were asked questions about birth-control sabotage, pregnancy coercion and intimate partner violence to assess their experience of pregnancy coercion and birth control sabotage. Questions included:
- "Has someone you were dating or going out with ever told you not to use any birth control" or "… said he would leave you if you would not get pregnant?"
- "Has someone you were dating or going out with ever taken off the condom while you were having sex so that you would get pregnant?"
Approximately one in five young women said they experienced pregnancy coercion and 15 percent said they experienced birth control sabotage. Over half the respondents -- 53 percent -- said they had experienced physical or sexual violence from an intimate partner. More than a third of the women who reported partner violence -- 35 percent -- also reported either pregnancy coercion or birth control sabotage.
"We have known about the association between partner violence and unintended pregnancy for many years," said Jay Silverman, the study's senior author and an associate professor of society, human development and health in the Harvard School of Public Health. "What this study shows is that reproductive coercion likely explains why unintended pregnancies are far more common among abused women and teens."
The study authors said the research underscores the importance of educating women seeking care about reproductive coercion, and ensuring that women who are seeking reproductive health services are offered counseling on ways to prevent pregnancy that are less vulnerable to partner interference, as well as connected to domestic violence-related services. The study also highlights the importance of working with young men to prevent both violence against female partners and coercion around pregnancy.
"This study confirms that women experiencing partner violence are more likely to have greater need for sexual and reproductive health services," Miller said. "Thus, clinical settings that offer reproductive health services likely offer the greatest opportunity to identify women experiencing partner violence and to ensure that women receive the counseling and support they may need." Comprehensive assessment in clinical settings for pregnancy coercion, birth control sabotage and intimate partner violence should be considered a priority in the context of family planning services. Moreover, public health efforts to reduce unintended pregnancy should ensure that discussions of reproductive coercion are included in pregnancy prevention programs, she said.
Pregnancy Coercion, Intimate Partner Violence and Unintended Pregnancy,
Elizabeth Miller, Michele R. Decker, Heather L. McCauley, Daniel J. Tancredi, Rebecca R. Levenson, Jeffrey Waldman, Phyllis Schoenwald, Jay G. Silverman
Contraception article in press
Link to Contraception abstract
Saturday, January 30, 2010
It is well known that smokers damage their health by directly inhaling cigarette smoke. Now, research published in BioMed Central's open access journal Environmental Health has shown that they are at additional risk from breathing environmental tobacco smoke, contrary to the prevailing assumption that such risks would be negligible in comparison to those incurred by actually smoking.
Maria Teresa Piccardo worked with a team of researchers from the National cancer Research Institute, Genoa, Italy, to study the exposure of newsagents in the city to harmful cigarette smoke.
She said, "Newsagents were chosen because they work alone in small newsstands, meaning that any tobacco smoke in the air they breathe is strictly correlated to the number of cigarettes smoked by that newsagent. We studied the contribution environmental tobacco smoke made to carcinogen exposure in 15 active smokers."
The researchers found that environmental tobacco smoke may have a significant impact on smokers' health. For someone who smokes 14 cigarettes a day, their own second hand smoke resulted in exposure the equivalent of smoking an extra 2.6 cigarettes.
According to Piccardo, "Both active and passive smoking contributions should always be considered in studies about health of active smokers."
Is the smokers exposure to environmental tobacco smoke negligible?
Maria Teresa Piccardo, Anna Stella and Federico Valerio.
Environmental Health, 2010, 9:5doi:10.1186/1476-069X-9-5
Link to EH abstract
Here's a piece of research that might leave you tickled: laughter is a universal language, according to new research.
The study, conducted with people from Britain and Namibia, suggests that basic emotions such as amusement, anger, fear and sadness are shared by all humans.
Everybody shares the vast majority of their genetic makeup with each other, meaning that most of our physical characteristics are similar. We all share other attributes, too, such as having complex systems of communication to convey our thoughts, feelings and the intentions of those around us, and we are all able to express a wide range of emotions through language, sounds, facial expressions and posture. However, the way that we communicate is not always the same -- for example, people from different cultures may not understand the same words and phrases or body language.
In an attempt to find out if certain emotions are universal, researchers led by Professor Sophie Scott from UCL (University College London) have studied whether the sounds associated with emotions such as happiness, anger, fear, sadness, disgust and surprise are shared amongst different cultures. The results of their study, funded by the Wellcome Trust, Economic and Social Research Council, University of London Central Research Fund and UCL, are published in the Proceedings of the National Academy of Sciences. They provide further evidence that such emotions form a set of basic, evolved functions that are shared by all humans.
Dr Disa Sauter, studied people from Britain and from the Himba, a group of over 20,000 people living in small settlements in northern Namibia as part of her PhD research at UCL. In the very remote settlements, where the data for the present study were collected, the individuals live completely traditional lives, with no electricity, running water, formal education, or any contact with people from other groups.
Participants in the study listened to a short story based around a particular emotion, for example, how a person is very sad because a relative of theirs had died recently. At the end of the story they heard two sounds -- such as crying and of laughter -- and were asked to identify which of the two sounds reflected the emotion being expressed in the story. The British group heard sounds from the Himba and vice versa.
"People from both groups seemed to find the basic emotions -- anger, fear, disgust, amusement, sadness and surprise -- the most easily recognizable," says Professor Scott, a Wellcome Trust Senior Research Fellow. "This suggests that these emotions -- and their vocalizations -- are similar across all human cultures."
The findings support previous research which showed that facial expressions of these basic emotions are recognized across a wide range of cultures. Despite the considerable variation in human facial musculature, the facial muscles that are essential to produce the basic emotions are constant across individuals, suggesting that specific facial muscle structures have likely evolved to allow individuals to produce universally recognizable emotional expressions.
One positive sound was particularly well recognized by both groups of participants: laughter. Listeners from both cultures agreed that laughter signified amusement, exemplified as the feeling of being tickled.
"Tickling makes everyone laugh -- and not just humans," says Dr Disa Sauter, who tested the Himba and English participants. "We see this happen in other primates such as chimpanzees, as well as other mammals. This suggests that laughter has deep evolutionary roots, possibly originating as part of playful communication between young infants and mothers.
"Our study supports the idea that laughter is universally associated with being tickled and reflects the feeling of enjoyment of physical play."
Previous studies have shown that smiling is universally recognized as a signal of happiness, raising the possibility that laughter is the auditory equivalent of smiles, both communicating a state of enjoyment. However, explains Professor Scott, it is possible that laughter and smiles are in fact quite different types of signals, with smiles functioning as a signal of generally positive social intent, whereas laughter may be a more specific emotional signal, originating in play.
Not all positive sounds were easily recognizable to both cultures, however. Some, such as the sound of pleasure or achievement appear not to be shared across cultures, but are instead specific to a particular group or region. The researchers believe this may be due to the function of positive emotions, which facilitate social cohesion between group members. Such bonding behavior may be restricted to in-group members with whom social connections are built and maintained. However, it may not be desirable to share such signals with individuals who are not members of one's own cultural group.
Cross-cultural recognition of basic emotions through nonverbal emotional vocalizations
Disa A. Sauter, Frank Eisner, Paul Ekman, and Sophie K. Scott
PNAS published online before print January 25, 2010, doi:10.1073/pnas.0908239106
Link to PNAS abstract
Lemelson-MIT Program press release(January 28, 2010)
2010 Lemelson-MIT Invention Index Reveals Ways To Enhance Teens’ Interest In Science, Technology, Engineering And Mathematics In The Classroom And Beyond
Survey Shows Need for Creative Activities, Strong Educators and Mentors
Many believe the key to strengthening the U.S. economy and competing globally lies in fostering an innovative culture and educating America's youth in science, technology, engineering and mathematics (STEM). According to this year's Lemelson-MIT Invention Index , an annual survey that gauges Americans' perceptions about invention and innovation, teens are enthusiastic about these subjects, with 77 percent interested in pursuing a STEM career.
Hands-On Learning Approach Needed
The positive findings of this year's survey come on the heels of President Obama's introduction of Educate to Innovate, a campaign designed to increase interest and improve performance of U.S. students in STEM. The focus of Educate to Innovate is on hands-on activities outside the classroom, which the Lemelson-MIT Invention Index revealed is one of the most effective ways to engage youth ages 12 through 17.
Teens listed activities such as field trips to places where they can learn about STEM (66 percent) and access to places outside the classroom where they can go to build things and conduct experiments (53 percent) as the best ways to get them interested in these subjects. Highlighting the need for non-traditional learning regardless of setting, two-thirds of teens chose hands-on individual projects and hands-on group projects as the types of classroom-based educational methods they enjoy most. This finding aligns with recent reported trends on an increasing interest in tinkering and hands-on work.
"Increasing teen's exposure to STEM through hands-on activities will result in a more positive perception of these important subjects," said Leigh Estabrooks, invention education officer with the Lemelson-MIT Program, a non-profit organization that recognizes outstanding inventors and inspires young people to pursue creative lives and careers through invention. "It's encouraging that the White House and large corporations are taking a vested interest in STEM education. Supporting teens and giving them the resources to pursue these fields is vital."
Power of Teachers, Mentors in STEM Education
The survey also found that while in the classroom, educators play a powerful role in exciting teens about STEM -- more than half of teens (55 percent) would be more interested in STEM simply by having teachers who enjoy the subjects they teach. The 2009 Lemelson-MIT Invention Index found that mentorship plays an important role in teens' motivations; 43 percent said that role models in STEM fields would increase their interest in learning about these areas.
An overwhelming amount of respondents wishing they knew more about STEM in order to create or invent something (85 percent); however, a majority might be discouraged from pursuing professions in these areas due to a lack of understanding of the subjects or what people in these fields do, and not knowing anyone who works in these fields (51 percent). In addition, with less than one-fifth of respondents feeling scientists contribute most to society's well-being, and even fewer selecting engineers (5 percent), many teens may lack a full understanding of the societal impact that STEM professionals have, further exposing the need for teachers and mentors in these areas.
Fostering Needs of Future Innovators
The Lemelson-MIT InvenTeam initiative is one way teens can get direct access to hands-on learning and STEM professionals. InvenTeams are teams of high school students, teachers and mentors that receive grants up to $10,000 each to invent technological solutions to real-world problems. InvenTeam projects this year include a portable, human-powered UV water filtration device, a physical therapy chair designed to reduce muscular atrophy, and a temperature-sensitive color-changing roof to combat global warming.
Joshua Schuler, executive director of the Lemelson-MIT Program, says, "Despite the need for more hands-on educational programs, it's encouraging to know that today's teens do have aspirations to invent and innovate. Schools and companies need to continue to facilitate access to STEM tools and mentors, and encourage teens to pursue their inventive passions." Schuler adds, "Introducing students to STEM at a young age helps them connect the dots between everyday invention and careers that can improve society and the U.S. economy."
About the Lemelson-MIT Program: celebrating innovation, inspiring youth
The Lemelson-MIT Program recognizes the outstanding inventors and innovators transforming our world, and inspires young people to pursue creative lives and careers through innovation.
Jerome H. Lemelson, one of U.S. history’s most prolific inventors, and his wife Dorothy founded the Lemelson-MIT Program at the Massachusetts Institute of Technology in 1994. It is funded by The Lemelson Foundation and administered by the School of Engineering. The Lemelson Foundation uses its resources to inspire, encourage and recognize inventors, innovators and entrepreneurs to support invention-led economic, social and environmentally sustainable development. It has donated or committed more than $150 million in support of its mission to improve lives through invention in the U.S. and developing countries.
Friday, January 29, 2010
A paper by a University of Hertfordshire academic published today (29 January 2010), reports that excess ecstasy-related death rates in young users is a cause for concern.
Professor Fabrizio Schifano at the University’s School of Pharmacy, is lead author for a paper entitled Overview of Amphetamine-Type Stimulant Mortality Data – UK, 1997 – 2007, which is published in Neuropsychobiology online.
The researchers reviewed stimulant-related deaths for the whole of the UK from the National Programme on Substance Abuse Deaths (np-SAD) database and from the British Crime Survey 2001-2007 results and found that identified 832 amphetamine and methylamphetamine-related deaths and 605 ecstasy-related deaths.
What was of more concern to Professor Fabrizio and the researchers was the fact that the fatalities from ecstasy during that period were typically identified in victims who were young and healthy.
The report, which covered an 11-year, UK-wide analysis of mortality from these drugs, noted that deaths seemed to have dropped in 2000 to peak once again over the following years and then after a drop again in 2003, it increased again over the following years.
Commenting on the findings, Professor Schifano said: “These data seem to support the hypothesis that young individuals seem to suffer extreme consequences after excessive intake of ecstasy. This is an issue of public health concern which deserves further studies.”
Overview of Amphetamine-Type Stimulant Mortality Data – UK, 1997–2007
Fabrizio Schifano, John Corkery, Vinesha Naidoo, Adenekan Oyefeso, Hamid Ghodse
Neuropsychobiology 2010;61:122-130 (DOI: 10.1159/000279302)
Link to Neuropsych abstract
HIV-positive women using progestogen-only hormonal contraception may be at increased risk for negative metabolic outcomes, warned researchers in a recent article in the Journal of Acquired Immune Deficiency Syndromes.
Their longitudinal study of an ethnically diverse United States cohort found that HIV-positive women who took progestogen-only hormonal contraception (HC) had lower fasting high-density lipoprotein (HDL) and higher levels of insulin resistance than HIV-positive women who took the combined contraceptive pill.
This finding is of particular concern because women using progestogen-only contracaptive methods may have chosen this option because they already have risk factors for heart disease.
Progestogen-only contraceptive methods may be chosen by women for whom combined contraceptive pills containing both oestrogen and progestogen (also known as progestin in the US) might not be suitable. These include women with a history of blood clots, smokers aged over 35, women with high blood pressure, breastfeeding women and migraine sufferers.
But hormonal contraception is already known to have undesirable metabolic effects in the general population. However, HIV-positive women’s metabolic responses to hormonal contraception have not been closely studied, despite the fact that untreated HIV infection is associated with lower level of 'good' HDL cholesterol, the high rates of raised lipids, diabetes and insulin resistance in people with HIV and the indications of elevated cardiovascular risk in people with HIV.
An additional concern is that two contraceptive methods that lack interactions with antiretrovirals from the non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor drug classes are progestogen-only products, and therefore more likely to be considered suitable for women with HIV.
Hormonal contraception and metabolic outcomes in women with or at risk for HIV infection.
Womack, Julie A CNM, APRN, PhD; Scherzer, Rebecca PhD; Cole, Stephen R PhD; Fennie, Kristopher MPH, PhD; Williams, Ann B RN, EdD; Grey, Margaret RN, DrPH; Minkoff, Howard MD; Anastos, Kathryn MD; Cohen, Mardge H MD; Tien, Phyllis C MD
JAIDS Journal of Acquired Immune Deficiency Syndromes: December 2009 - Volume 52 - Issue 5 - pp 581-587 doi: 10.1097/QAI.0b013e3181b9e5ee.
Link to JAIDS abstract
Using cells from mice, scientists from Iowa and Iran have discovered a new strategy for making embryonic stem cell transplants less likely to be rejected by a recipient's immune system. This strategy, described in a new research report appearing in the February 2010 print issue of The FASEB Journal, involves fusing bone marrow cells to embryonic stem cells.
Once fused, the hybrid cells have DNA from both the donor and recipient, raising hopes that immune rejection of embryonic stem cell therapies can be avoided without drugs.
"Our study shows that transplanted bone marrow cells fuse not only with bone marrow cells of the recipient, but with non-hematopoietic cells, suggesting that if we can understand the process of cell fusion better, we may be able to target certain organ injuries with the patient's own bone marrow cells and repair the tissues," said Nicholas Zavazava, M.D., Ph.D., a University of Iowa researcher involved in the work.
Although the study holds great promise for future embryonic stem cell therapies, the results may be even more far reaching. Zavazava and colleagues used two different mouse strains, one as the donor and the other as the recipient. When bone marrow cells were engrafted into the recipient, they tested for the presence of both donor and recipient cells and found three different types of cells: donor cells, recipient cells, and fused cells that had DNA from the donor and recipient.
They then discovered that these cells could fuse with many different types of cells in addition to embryonic stem cells, including those from the liver, kidney, heart, and gut. Although more work is necessary to determine the exact clinical outcomes, the discovery raises the possibility that bone marrow cells could be fused to transplant organs to reduce the likelihood of rejection. They could also be fused to failing organs to support regeneration.
"Unlike machines where the same part can be used for several different makes and models, each of us is custom built, and our immune system does the quality control," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "As a result, human replacement parts, or organs, need to closely match the tissue of the recipient. This research uses bone marrow cells to fuse with a patient tissues so that nothing transplanted is rejected by our immune systems, and brings universal graft survival closer to reality."
Cell fusion of bone marrow cells and somatic cell reprogramming by embryonic stem cells.
Sabrina Bonde, Mehrdad Pedram, Ryan Stultz, and Nicholas Zavazava.
The FASEB Journal, 2010; 24 (2): 364 DOI: 10.1096/fj.09-137141
Link to FASEB abstract
Researchers from University Hospital in Umea, Sweden, have identified several cytokines, cytokine-related factors, and chemokines that increase significantly prior to rheumatoid arthritis (RA) disease onset. These findings confirm those of earlier studies which suggest that the risk of developing RA can be predicted and disease progression may be prevented.
Complete findings of this study are published in the February issue of Arthritis & Rheumatism, a journal of the American College of Rheumatology.
Rheumatoid arthritis is a chronic autoimmune disease characterized by joint inflammation involving the synovial (lubricating fluid of the joints) tissue and eventually leading to destruction of cartilage and bone. The cause leading to disease development and progression is not completely understood, although various cells of the immune system and of synovial origin are suggested to be involved. Numerous cytokines are expressed and are functionally active in the synovial tissue once the disease has developed. Now a research team led by Solbritt Rantapää-Dahlqvist, M.D. has found that several of these cytokine levels spike as much as several years prior to the development of arthritic symptoms.
An early and accurate diagnosis of RA is crucial. According to the American College of Rheumatology, RA can be difficult to diagnose because it may begin with only subtle symptoms, such as achy joints or early morning stiffness. Many diseases including lupus, osteoarthritis and fibromyalgia, especially early on, mimic the symptoms of RA making diagnosis more difficult. Studies have shown that people who receive early treatment for RA feel better sooner and more often, are more likely to lead an active life, and are less likely to experience the type of joint damage that leads to joint replacement.
To determine whether cytokines, cytokine-related factors, and chemokines are up-regulated prior to the development of RA, and which ones are involved, the team conducted a nested case-control study within the Medical Biobank of Northern Sweden. Blood samples were analyzed from 86 individuals before the appearance of symptoms of RA (pre-patients), from 69 of the pre-patients after the onset of RA, and from 256 matched control subjects (1:3 ratio). A consecutive time-dependent involvement of the immune system in disease development and progression was evaluated. The plasma levels of 30 cytokines, related factors, and chemokines were measured using a multiplex system. Individuals in whom RA subsequently developed were discriminated from control subjects mainly by the presence of Th1 cell-, Th2 cell-, and Treg cell-related cytokines, while chemokines, stromal cell-derived cytokines, and angiogenic-related markers separated patients after the development of RA from individuals before the onset of RA.
"We observed a clear relationship between cytokines related not only to Th1, Th2, and Treg cells but also to Th17 and the presence of anti-CCP antibodies, thereby supporting the concept that the immune system was already stimulated and disease was developing toward RA," explains Dr. Rantapää-Dahlqvist. Researchers found that blood samples obtained from individuals had elevated concentrations of proinflammatory cytokines, cytokine-related factors, and chemokines, indicating immune system activation prior to any symptoms of joint involvement. "Our findings present an opportunity for better predicting the risk of developing RA and possibly preventing disease progression," concluded Dr. Rantapää-Dahlqvist.
Up-regulation of cytokines and chemokines predates the onset of rheumatoid arthritis.
Heidi Kokkonen, Ingegerd Söderström , Joacim Rocklöv, Göran Hallmans, Kristina Lejon, Solbritt Rantapää Dahlqvist
Arthritis & Rheumatism, 2010; Volume 62 Issue 2, Pages 383 - 391 DOI: 10.1002/art.27186
Link to A&R abstract
The discovery of a major player in the body's regulation of iron levels should provide a new target for drugs that prevent common iron deficiency as well as rare, potentially deadly iron overload, researchers said.
Medical College of Georgia researchers noted in the online edition of Blood that the protein neogenin, a receptor that aids in neural development, is also part of the body's interwoven regulatory process for iron. The receptor, located on the cell surface, should be an easy target for drug development to help increase or decrease iron levels as needed, said Dr. Wen-Cheng Xiong, the study's corresponding author and a developmental neurobiologist at the Medical College of Georgia Schools of Medicine and Graduate Studies.
Iron, an essential nutrient in foods such as meats, beans and spinach, is used by all cells but primarily helps red blood cells deliver oxygen throughout the body. However, in some individuals, low levels cause iron deficiency-anemia while genetic diseases such as juvenile hemochromatosis or blood transfusions can result in toxic levels of iron in the body.
In the brain, neogenin works with other molecules to heard neurons in the right direction. One of those molecules, repulsive guidance molecules, or RGMs, are already known to help regulate iron levels, which led MCG researchers to suspect neogenin had a role as well.
Studies in mice showed neogenin inhibits secretion of an RGM gene called hemojuvelin. That reduces the signaling of a protein that reduces expression of hepcidin, a hormone released by the liver to control circulating iron levels by storing it in the spleen until it is needed and directing the intestines on how much iron to absorb or eliminate. In cells in culture, researchers consistently found that increased expression of hemojuvelin increases hepcidin expression while suppression decreases it.
Next steps include determining whether neogenin expression is up or down in patients with iron-related issues such as anemia or juvenile hemochromatosis.
"If that is verified, drugs to stimulate or inhibit neogenin would be useful," Dr. Xiong said. She predicts that neogenin expression will be increased in patients with iron deficiency anemia and decreased in iron-overload conditions.
Neogenin inhibits HJV secretion and regulates BMP induced hepcidin expression and iron homeostasis
D-H. Lee, L-J Zhou, Z. Zhou, J-X. Xie, J-U. Jung, Y. Liu, C-X. Xi, L. Mei, and W-C. Xiong
Blood, prepublished online January 11 2010; doi:10.1182/blood-2009-11-251199
Link to Blood abstract
Science Daily (January 28, 2010) —
In an acute viral infection, most of the white blood cells known as T cells differentiate into cells that fight the virus and die off in the process. But a few of these "effector" T cells survive and become memory T cells, ensuring that the immune system can respond faster and stronger the next time around.
Scientists have identified a molecule that defines which cells are destined to become memory T cells just a few days after a viral infection begins. The finding could guide the development of more effective vaccines for challenging infections such as HIV/AIDS and also cancer.
The results were published online this week by the journal Immunity. The senior author is Rafi Ahmed, PhD, director of the Emory Vaccine Center, a Georgia Research Alliance Eminent Scholar and a member of the National Academy of Sciences.
Working with Ahmed, postdoctoral fellows Vandalia Kalia and Surojit Sarkar tracked memory T cell formation in mice infected with lymphocytic choriomeningitis virus, a virus that causes an acute infection. They observed that a few days after infection begins, T cells separate into two groups: one with high levels of the molecule CD25 on their surfaces and one with low levels of CD25. Later on, all T cells reduce their levels of CD25 and the differences disappear as the infection is cleared.
"The outstanding question in our field has been: when do T cells commit to becoming memory cells," Kalia says. "This is one of the earliest points where we have been able to see these groups of cells with distinct fates."
CD25 is a molecule on the outside of cells that allows them to respond more sensitively to interleukin 2 (IL2), a growth factor that stimulates T cells. IL2 regulates immune activation. The most commonly used drugs to control the immune systems of transplant patients tamp down production of IL2.
During viral infection, cells with more CD25 respond to IL2 more strongly and produce more battle-ready progeny, but they don't stick around. Cells with low levels of CD25 are five times more able to persist long-term, and they also acquire the ability to travel throughout the body's lymph nodes -- key properties of memory T cells compared to effector cells.
"Apparently, cells that receive prolonged IL-2 signals are pushed further down the effector path and hence exhibit decreased potential to form long-lived memory cells," Sarkar says. "It may be beneficial that not all of the T cells burn themselves out fighting the virus so that memory-fated cells can conserve resources for the next encounter."
When mice are given extra IL2, T cells exhibit more pronounced effector characteristics. Sarkar says the results will be instructive for researchers developing vaccines because, combined with previous observations in the field, they show that both too much IL2 and its absence can be detrimental to the development of immunological memory. Because IL-2 is a key regulator of the immune system, some clinical studies have examined whether IL2 can boost immune responses against HIV and cancer, for example.
The differences between the groups of T cells may arise because not all T cells get the same level of stimulation as the infection progresses, Kalia says. "In this situation, a spectrum of effector cells with a range of differentiation states and memory potential likely develops," she says.
Researchers from Loma Linda University, Dana-Farber Cancer Institute and Cornell University also contributed to the paper.
The research was supported by the National Institutes of Health, the Bill and Melinda Gates Foundation and the Elizabeth Glaser Pediatric AIDS Foundation.
Prolonged interleukin-2Ra expression on virus-specific CD8 T cells favors terminal effector differentiation in vivo.
Vandana Kalia, Surojit Sarkar, Shruti Subramaniam, W. Nicholas Haining, Kendall A. Smith, Rafi Ahmed
Immunity, Volume 32, Issue 1, 91-103, 21 January 2010 doi 10.1016/j.immuni.2009.11.010
Link to Immunity abstract
— Researchers at MIT and Rockefeller University have successfully grown hepatitis C virus in otherwise healthy liver cells in the laboratory, an advance that could allow scientists to develop and test new treatments for the disease.
To develop better treatments, researchers need to test them in laboratory experiments in liver cells, but it has been difficult to create a suitable tissue model because healthy liver cells tend to lose their liver functions when removed from the body.
Previously, researchers have been able to induce cancerous liver cells to survive and reproduce outside the body, but those cells are not sufficient for studying hepatitis C because their responses to infection are different from those of normal liver cells.
Now, Bhatia, in collaboration with Charles Rice of the Rockefeller University, has developed a way to maintain liver cells for four to six weeks by precisely arranging them on a specially patterned plate. The cells can be infected with hepatitis C for two to three weeks, giving researchers the chance to study the cells' responses to different drugs.
The new model, described in the Proceedings of the National Academy of Sciences, could allow researchers to test the effectiveness of various combinations of drugs, including interferon, a common current treatment, and experimental antibodies that may block the virus from entering cells.
The researchers used healthy liver cells that had been cryogenically preserved and grew them on special plates with micropatterns that direct the cells where to grow. The liver cells were strategically interspersed with other cells called fibroblasts that support the growth of liver tissue.
"If you just put cells on a surface in an unorganized way, they lose their function very quickly," says Bhatia. "If you specify which cells sit next to each other, you can extend the lifetime of the cells and help them maintain their function."
The current system may already be suitable to screen drugs against the strain of hepatitis C used in this work; however, this strain, which was derived from a Japanese patient with fulminant hepatitis is the only strain ever successfully grown in a laboratory environment. The researchers hope to modify the system so they can grow additional strains, such as those more common in North America, which would allow for more thorough drug testing.
Persistent hepatitis C virus infection in microscale primary human hepatocyte cultures.
Ploss, A, Khetani, SR, Jones, CT, Sydera, AJ, Trehan, K, Gaysinskaya, VA, Mua, K, Ritola, K, Rice, CM, and Bhatia, SN
Proceedings of the National Academy of Sciences, 2010; (in press)
Thursday, January 28, 2010
The presumption that children need both a mother and a father is widespread. It has been used by proponents of Proposition 8 to argue against same-sex marriage and to uphold a ban on same-sex adoption.
On the other end of the political spectrum, Barack Obama endorsed the vital role of fathers in a 2008 speech: "Of all the rocks upon which we build our lives, we are reminded today that family is the most important. And we are called to recognize and honor how critical every father is to that foundation."
The lead article in the February issue of Journal of Marriage and Family challenges the idea that "fatherless" children are necessarily at a disadvantage or that men provide a different, indispensable set of parenting skills than women.
"Significant policy decisions have been swayed by the misconception across party lines that children need both a mother and a father. Yet, there is almost no social science research to support this claim. One problem is that proponents of this view routinely ignore research on same-gender parents," said sociologist Timothy Biblarz of the USC College of Letters, Arts and Sciences.
Extending their prior work on gender and family, Biblarz and Judith Stacey of NYU analyzed relevant studies about parenting, including available research on single-mother and single-father households, gay male parents and lesbian parents. "That a child needs a male parent and a female parent is so taken for granted that people are uncritical," Stacey said.
In their analysis, the researchers found no evidence of gender-based parenting abilities, with the "partial exception of lactation," noting that very little about the gender of the parent has significance for children's psychological adjustment and social success.
As the researchers write: "The social science research that is routinely cited does not actually speak to the questions of whether or not children need both a mother and a father at home. Instead proponents generally cite research that compares [heterosexual two-parent] families with single parents, thus conflating the number with the gender of parents."
Indeed, there are far more similarities than differences among children of lesbian and heterosexual parents, according to the study. On average, two mothers tended to play with their children more, were less likely to use physical discipline, and were less likely to raise children with chauvinistic attitudes. Studies of gay male families are still limited.
However, like two heterosexual parents, new parenthood among lesbians increased stress and conflict, exacerbated by general lack of legal recognition of commitment. Also, lesbian biological mothers typically assumed greater caregiving responsibility than their partners, reflecting inequities among heterosexual couples.
"The bottom line is that the science shows that children raised by two same-gender parents do as well on average as children raised by two different-gender parents. This is obviously inconsistent with the widespread claim that children must be raised by a mother and a father to do well," Biblarz said.
Stacey concluded: "The family type that is best for children is one that has responsible, committed, stable parenting. Two parents are, on average, better than one, but one really good parent is better than two not-so-good ones. The gender of parents only matters in ways that don't matter."
How Does the Gender of Parents Matter?
Timothy J. Biblarz, Judith Stacey
Journal of Marriage and Family Volume 72, Issue 1, Date: February 2010, Pages: 3-22 doi 10.1111/j.1741-3737.2009.00678.x
Link to JMF abstract
Ideal Families and Social Science Ideals
Timothy J. Biblarz, Judith Stacey
Journal of Marriage and Family Volume Volume 72, Issue 1, Date: February 2010, Pages: 41-44 doi 10.1111/j.1741-3737.2009.00682.x
Link to JMF abstract
Even Superman needed to retire to a phone booth for a quick change. But now scientists at the Stanford University School of Medicine have succeeded in the ultimate switch: transforming mouse skin cells in a laboratory dish directly into functional nerve cells with the application of just three genes. The cells make the change without first becoming a pluripotent type of stem cell — a step long thought to be required for cells to acquire new identities.
The finding could revolutionize the future of human stem cell therapy and recast our understanding of how cells choose and maintain their specialties in the body.
“We actively and directly induced one cell type to become a completely different cell type,” said Marius Wernig, MD, assistant professor of pathology and a member of Stanford’s Institute for Stem Cell Biology and Regenerative Medicine. “These are fully functional neurons. They can do all the principal things that neurons in the brain do.” That includes making connections with and signaling to other nerve cells — critical functions if the cells are eventually to be used as therapy for Parkinson’s disease or other disorders.
Although previous research has suggested that it’s possible to coax specialized cells to exhibit some properties of other cell types, this is the first time that skin cells have been converted into fully functional neurons in a laboratory dish. The change happened within a week and with an efficiency of up to nearly 20 percent. The researchers are now working to duplicate the feat with human cells.
Wernig, Vierbuchen and graduate student Austin Ostermeier amassed a panel of 19 genes involved in either epigenetic reprogramming or neural development and function. They used a virus called a lentivirus to infect skin cells from embryonic mice with the genes, and then monitored the cells’ response. After 32 days they saw that some of the former skin cells now looked like neural cells and expressed neural proteins.
The researchers used a mix-and-match approach to winnow the original pool of 19 genes down to just three. They also tested the procedure on skin cells from the tails of adult mice. They found that about 20 percent of the former skin cells transformed into neural cells in less than a week. That may not, at first, sound like a quick change, but it is vast improvement over iPS cells, which can take weeks. What’s more, the iPS process is very inefficient: Usually only about 1 to 2 percent of the original cells become pluripotent.
In Wernig’s experiments, the cells not only looked like neurons, they also expressed neural proteins and even formed functional synapses with other neurons in laboratory dish.
“We were very surprised by both the timing and the efficiency,” said Wernig. “This is much more straightforward than going through iPS cells, and it’s likely to be a very viable alternative.” Quickly making neurons from a specific patient may allow researchers to study particular disease processes such as Parkinson’s in a laboratory dish, or one day to even manufacture cells for therapy.
The research suggests that the pluripotent stage, rather than being a required touchstone for identity-shifting cells, may simply be another possible cellular state. Wernig speculates that finding the right combination of cell-fate-specific genes may trigger a domino effect in the recipient cell, wiping away restrictive DNA modifications and imprinting a new developmental fate on the genomic landscape.
“It may be hard to prove,” said Wernig, “but I no longer think that the induction of iPS cells is a reversal of development. It’s probably more of a direct conversion like what we’re seeing here, from one cell type to another that just happens to be more embryonic-like. This tips our ideas about epigenetic regulation upside down.”
Direct conversion of fibroblasts to functional neurons by defined factors
Thomas Vierbuchen, Austin Ostermeier, Zhiping P. Pang, Yuko Kokubu, Thomas C. Südhof & Marius Wernig
Nature advance online publication 27 January 2010 doi:10.1038/nature08797
Link to Nature abstract
Researchers at the University of Illinois at Chicago and Israel's Weizman Institute of Science have found that two antibiotics working together might be more effective in fighting pathogenic bacteria than either drug on its own.
Individually, lankacidin and lankamycin, two antibiotics produced naturally by the microbe streptomyces, are marginally effective in warding off pathogens, says Alexander Mankin, professor and associate director of the UIC Center for Pharmaceutical Biotechnology and lead investigator of the portion of the study conducted at UIC.
Mankin's team found that when used together, the two antibiotics are much more successful in inhibiting growth of dangerous pathogens such as MRSA (methicillin-resistant Staphylococcus aureus) and possibly others.
Lankacidin and lankamycin act upon the ribosomes, the protein-synthesizing factories of the cell. A newly-made protein exits the ribosome through a tunnel through the ribosome body. Some antibiotics stave off an infection by preventing the ribosome from assembling proteins, while others bind in the tunnel and block the protein's passage.
Through the use of X-ray crystallography, which determines the arrangement of atoms in biological molecules, the Israeli team, led by Ada Yonath, a 2009 Nobel Prize winner, discovered the exact binding site of lankacidin in the ribosome. Mankin's group demonstrated that lankacidin prevents the ribosome from assembling new proteins.
However, when researchers realized that streptomyces also manufactures lankamycin, they became curious whether the two drugs might help each other. Biochemical analysis and molecular modeling showed that lankamycin binds in the ribosomal tunnel right next to lankacidin.
"What we found most amazing is that the two antibiotics appeared to help each other in stopping pathogens from making new proteins and in inhibiting bacterial growth," Mankin said.
Today, many companies are attempting to make individual drugs better, Mankin said. What the research suggests is that in some cases, it is a "much better strategy not to improve individual drugs, but the combinations of drugs that can act together."
The structure of ribosome-lankacidin complex reveals ribosomal sites for synergistic antibiotics
Tamar Auerbach, Inbal Mermershtain, Chen Davidovich, Anat Bashan, Matthew Belousoff, Itai Wekselman, Ella Zimmerman, Liqun Xiong, Dorota Klepacki, Kenji Arakawa, Haruyasu Kinashi, Alexander S. Mankin, and Ada Yonath
Proceedings of the National Academy of Sciences published online before print January 11, 2010, doi:10.1073/pnas.0914100107
Link to PNAS abstract
Keith Alcorn for Aidsmap January 28, 2010
A genetic marker associated with atherosclerosis and oxidative stress in mice and humans is strongly associated with the incidence of cardiovascular disease, metabolic syndrome and poorer immune recovery in people with HIV, Spanish researchers report in the February 15th edition of the Journal of Infectious Diseases.
If proven in larger studies and different populations the finding could lead to the use of genetic screening to differentiate patients with HIV at higher risk of cardiovascular disease, or to identify patients who may benefit from antioxidant therapy and lipid-lowering drugs to modify their risk, even when their cholesterol levels are near-normal.
Paraoxanase-1 gene haplotypes are associated with metabolic disturbances, atherosclerosis and immunologic outcome in HIV-infected patients
Sandra Parra, Judit Marsillach, Gerard Aragonés, Raúl Beltrán, Manuel Montero, Blai Coll, Bharti Mackness, Michael Mackness, Carlos Alonso-Villaverde, Jorge Joven, and Jordi Camps
The Journal of Infectious Diseases 2010 201: 627 – 634 DOI: 10.1086/650312
Link to JID abstract
WOM AGAINST HIV
Word Of Mouth is a virtual as well as a real photographic exhibit in which
everyone can be spokesperson of the HIV prevention cause.
With the intention of spreading the cause, we put the cause on everyone’s mouth.
The mouth gives us the possibility to let our voice be heard.
Wednesday, January 27, 2010
Female elementary school teachers who are anxious about math pass on to female students the stereotype that boys, not girls, are good at math. Girls who endorse this belief then do worse at math, research at the University of Chicago shows.
These findings are the product of a year-long study on 17 first- and second-grade teachers and 52 boys and 65 girls who were their students. The researchers found that boys' math performance was not related to their teacher's math anxiety while girls' math achievement was affected.
"Having a highly math-anxious female teacher may push girls to confirm the stereotype that they are not as good as boys at math, which in turn, affects girls' math achievement," said Sian Beilock, Associate Professor in Psychology and the Committee on Education at the University of Chicago, lead author of a paper, "Female Teachers' Math Anxiety Affects Girls' Math Achievement" published in the January 11 issue of the Proceedings of the National Academy of Sciences. Beilock is an expert on anxiety and stress as they relate to learning and performance.
More than 90 percent of elementary school teachers in the country are women and they are able to get their teaching certificates with very little mathematics preparation, according to the National Survey of Science and Mathematics Education. Other research shows that elementary education majors have the highest rate of mathematics anxiety of any college major.
The potential of these teachers to impact girls' performance by transmitting their own anxiety about mathematics has important consequences. Teachers' anxiety might undermine female students' confidence in learning mathematics throughout their years of schooling and also decrease their performance in other subjects, such as science and engineering, which are dependent on mathematical understanding.
To determine the impact of teachers' mathematics anxiety on students, the team assessed teachers' anxiety about math. Then, at both the beginning and end of the school year, the research team also tested the students' level of mathematics achievement and the gender stereotypes the students held.
To assess stereotypes, the students were told gender neutral stories about students who were good at mathematics and good at reading and then asked to draw a picture of a student who was good at mathematics and one that was good at reading. Researchers were interested in examining the genders of the drawings that children produced for each story.
At the beginning of the school year, student math achievement was unrelated to teacher math anxiety in both boys and girls. By the end of the school year, however, the more anxious teachers were about math, the more likely girls, but not boys, were to endorse the view that "boys are good at math and girls are good at reading." Girls who accepted this stereotype did significantly worse on math achievement measures at the end of the school year than girls who did not accept the stereotype and than boys overall.
Girls who confirmed a belief that boys are better in math than girls scored six points lower in math achievement than did boys or girls who had not developed a belief in the stereotype (102 for the girls who accepted the stereotype, versus 108 for the other students).
Other research has shown that elementary school children are highly influenced by the attitudes of adults and that this relationship is strongest for students and adults of the same gender. "Thus it may be that first- and second-grade girls are more likely to be influenced by their teachers' anxieties than their male classmates, because most early elementary school teachers are female and the high levels of math anxiety in this teacher population confirm a societal stereotype about girls' math ability," Beilock said.
The authors suggest that elementary teacher preparation programs could be strengthened by requiring more mathematics preparation for future teachers as well as by addressing issues of math attitudes and anxiety in these teachers.
Female teachers’ math anxiety affects girls’ math achievement
Sian L. Beilock, Elizabeth A. Gunderson, Gerardo Ramirez, and Susan C. Levine
Proceedings of the National Academy of Sciences PNAS published online before print January 25, 2010, doi:10.1073/pnas.0910967107
Link to PNAS article [pdf]