A new technique called adaptive statistical iterative reconstruction (ASIR) may enable radiologists to reduce patient radiation dose from computed tomography (CT) scans by up to 65 percent, according to a new study. CT scans are responsible for more than two thirds of the total radiation dose from medical imaging.

The iterative reconstruction technique enables radiologists to improve image quality, much like adjusting a TV antenna to make a “fuzzy” image sharper, while significantly reducing the radiation dose.
 
CT scans using the new ASIR method and the standard dose method were performed on a “Ëœphantom’ and on 12 patients. “We found nearly identical image quality using the reduced dose CT method with ASIR compared with the standard dose CT method without ASIR,” Amy Hara, MD, lead author of the study at Mayo Clinic Arizona in Scottsdale was quoted as saying. “In our study, patient radiation doses were reduced up to 65 percent using the low-dose IR method.”

“Finding a way to reduce radiation dose for routine body CT imaging has been an ongoing concern. Our study is significant because it shows that the low-dose ASIR method can significantly decrease the radiation dose along with the many risks associated with radiation exposure. In future studies, it will be important to not only evaluate image quality but to assess diagnostic accuracy,” said Dr. Hara. “ASIR is new to CT but in our practice it has been very successful.”

SOURCE:  American Journal of Roentgenology (AJR), September 2009

It is the job of businesses to limit the negative impact of the H1N1 influenza and seasonal flu outbreaks, officials of several U.S. agencies said Wednesday.

Officials from the U.S. Department of Health and Human Services’ Centers for Disease Control and Prevention, with input from the U.S. Department of Homeland Security, developed updated guidance for employers of all sizes to respond to the outbreak of H1N1 flu, commonly referred to as swine flu.

During an influenza pandemic, all sick people should stay home and away from the workplace, hand washing and covering coughs and sneezes should be encouraged, and routine cleaning of commonly touched surfaces should be performed regularly, the guidance said.

If severity increases, public health officials may recommend a variety of methods for increasing the physical distance between people — called social distancing — to reduce the spread of disease, such as school dismissal, child care program closure, canceling large community gatherings, canceling large business-related meetings, spacing workers farther apart in the workplace, canceling non-essential travel, and recommending work-from-home strategies for workers that can conduct their business remotely.

CDC recommends workers who appear to have an influenza-like illness be separated from other workers and be advised to go home until at least 24 hours after they are free of fever, the guidance said.

As a child progresses from one grade level to the next, there are certain behaviors parents and teachers can watch for to help recognize and rehabilitate subtle learning disabilities that could hinder the child’s long-term academic career, said a developmental pediatrician at Baylor College of Medicine (www.bcm.edu).

“When a child enters kindergarten, third grade, junior high and high school, the new learning environments add more stressors than the levels before,” said Dr. Sherry Vinson, an assistant professor of pediatrics – developmental pediatrics at BCM and chief of the developmental pediatrics service and clinic at Texas Children’s Hospital (www.texaschildrens.org). “Because of these new stressors, a subtle learning disability may be easier for the teacher and/or parent to identify.”

Vinson outlined behaviors in each grade level that may indicate the child is in need of extra help to keep up with the rest of his or her class.

KINDERGARTEN

Lack of attention in circle or story time may indicate a mild language delay, Vinson said.

“If the child is losing attention and wanting to get up and walk around while the rest of the group is intently listening to a story, he or she may not be able to connect with the story,” said Vinson. “This directly impacts his or her ability to listen, learn and follow rules.”

Another important kindergarten requirement ““ learning letters and numbers ““ can also bring out warning signs of a fine motor delay.

“If the child wants to run around and play when the rest of the children are making their letters and numbers, he or she may be visually unable to comprehend the lesson.”

Conduct grades in kindergarten should also be watched.

“Anytime the child receives a “Ëœneeds improvement’ grade in kindergarten, it may be a sign of a learning disability,” said Vinson.

THIRD GRADE

Third grade is the first grade that independence is expected in the child’s learning, said Vinson. “They go from learning to read, to reading to learn.”

Trouble focusing and/or completing worksheets and assigned readings is a classic example of a learning delay.  

Watch to see if the child is just sitting, looking around or out the window, Vinson said.

“They could have a mild reading delay and may not be able to recognize letters and smoothly decode the words,” said Vinson. “Longer reading passages are required in third grade, so a struggle may be more obvious.”  

If the child consistently makes Cs in the first and second grade, a learning disability is probable and may become more evident in third grade when more is expected of the child.

JUNIOR HIGH/MIDDLE SCHOOL

In junior high or middle school, the child’s attention faces a classic test by having to physically switch classes, go back to his or her locker and grab a book, Vinson said.

“If the child gets lost going down the hallway, gets to class without his homework, although he or she has completed it ““ these are signs of true inattentive disorganized ADHD,” said Vinson.

Consistent Cs and Ds on report cards should also be watched, especially in reading and math.

“We also see a lot of mild receptive language delay at this level,” said Vinson. “The child may be able to decode and recognize the site word, but has a reading fluency problem.”  

HIGH SCHOOL

By the time a child gets to high school, undiagnosed and unrecognized learning disabilities may be most obvious.

“A C in high school is not going to necessarily mean the child has a learning disability,” said Vinson. “There are completely new lifestyle interests and extracurricular activities. It’s going to be a challenge for the child to juggle everything.”

Vinson said consistent failing grades can mean the child has been struggling with a subtle, undiagnosed problem that needs to be addressed.

GETTING HELP

For children in public school, federal law requires that the school provide appropriate education to all children, including those with disabilities.

If a parent or teacher suspects a learning disability, the child can receive a variety of tests to confirm he or she may need extra support in reading, language and motor therapy.  

For more information about the Individuals with Disabilities Education Act visit http://www.fape.org/idea/.

“If these subtle signs go untreated or overlooked, they could pose a much larger problem for the child later in life,” said Vinson. “Parents can watch for these signs early in life to help their child achieve long-term academic success.”

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On The Net:

BCM

 As a new mother herself, Brenda Lohman admits to being shocked by the results of a new study she co-authored. It found that among nearly 1,000 low-income families in three major cities, one in four children between the ages of 11 and 16 reported having sex, with their first sexual intercourse experience occurring at the average age of 12.77.

“So if 12 years was the average age here, that meant that some kids were starting at 10 or younger,” said Lohman, an Iowa State University associate professor of human development and family studies (HDFS). “A handful of kids reported having sex as early as 8 or 9. We know from our follow-up interviews that one boy who reported having sexual intercourse for the first time at age nine had fathered four children by the time he was 18.”

“Those people who say that kids don’t have sex at that young of age should think again,” she said. “Definitely the age is the most shocking thing about this study.”

Tina Jordahl, a former Iowa State HDFS and public policy graduate student who is now a market research specialist with Hospice of Central Iowa, collaborated with Lohman on the study. It analyzes data from the “Welfare, Children and Families: A Three-City Study” — a six-year longitudinal investigation of low-income families living in Boston, Chicago and San Antonio. Their paper, titled “A biological analysis of risk and protective factors associated with early sexual intercourse of young adolescents,” was posted online in the Children and Youth Services Review and will be published in an upcoming issue of the journal.
Interview data for the study was first collected in 1999 on youth between the ages of 10 and 14, and again in 2001. Lohman says she also has data collected in 2006 from the same subjects, who were between 16 and 20 by that time.
Boys having sex earlier, more often than girls
In the study, boys reported their first sexual intercourse at younger ages (averaging 12.48) than girls (13.16). Boys also had nearly 10 percent higher frequency of intercourse than girls and were also more likely to experience sexual debut (20 percent to 14 percent) between the two years when the first two waves of data were collected.
Recent national research has found that 13 percent of girls and 15 percent of boys have had sex by the time they’re 16. Lohman says that means the rate of sex among her low-income sample is only slightly higher among the girls, but almost double among the boys
“The ages [of sexual debut] are a bit younger than the national samples, but not alarmingly so,” she said.
African Americans also had 12 percent more early sexual intercourse than whites (29 to 17 percent respectively), although racial differences did not change the age of their first intercourse.
The authors report that periods of instability in family structure and welfare use serve as risk factors for early sexual activity. They found that additional maternal education — beyond a high school level — was found to inhibit some of that activity.
“That can be for multiple reasons,” Lohman said. “It can be that mothers have better paying jobs and more stable home environment and they’re less likely to be in stressful circumstances. It could also be that mothers then have greater cognitive capacities to sort of sit down and discuss the pros and cons of waiting to have sex until you’re older.”

For that reason, the researchers propose allotting public funding to increase maternal education as a way to reduce early sexual promiscuity among their children.

Juvenile deliquency increases early sexual activity

The study also found the youths’ involvement in delinquent acts drastically increases the chances of early sexual activity.

Because of the gender differences in sexual debut, the authors also urge more gender-specific prevention programs that are implemented at earlier ages, especially among high risk populations.

“It may be that boys and girls, starting at younger ages, should have these programs that are designed separately by gender before they’re moved back together over time,” Lohman said. “And yes, they must start much, much younger than they do now. You have to start before those young kids — 10 or even younger — start becoming sexually active.”

She says the current political climate in Washington may be right for those types of programs to be developed.

“The Bush administration concentrated on abstinence education programs for all families across the spectrum of income, and Obama is definitely focusing on sexual education and prevention programs,” said Lohman. “He’s put a lot more money back into those programs that were stripped away during the Bush administration. And given his focus in other areas, he is concentrating on high-risk, low-income disadvantaged families as well.”

Lohman is currently working on research to determine the relationship between obesity and teen sexuality. She hopes to publish results from that study within the year.

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On The Net:

ISU

Drinking patterns in Spain may be changing from drinking with meals to binge drinking on weekends, a researcher in Spain says.

Binge drinkers are defined as males who drink five or more standard alcohol drinks, and females who drink four or more, on one occasion and within a two-hour interval.

Francisco Caamano-Isorna of the University of Santiago de Compostela says the traditional pattern in Spain — low intake of wine and beer during meals — may be changing.

Recent reports from the Spanish Drug Observatory suggest that the prevalence of binge drinking is increasing, he says in a statement.

The percentage of Spanish students who are binge drinkers is still low — 12.2 percent — compared to the United States — 40 percent — and other countries, Alberto Crego, a doctoral student at University of Santiago de Compostela says.

One of the reasons for this is because in Anglo-Saxon countries there is a longer tradition of drinking linked to weekend diversions and characterized by sporadic consumption of large quantities of alcohol in short periods, Crego says. While in Mediterranean countries such as Spain, alcohol consumption is traditionally more regular and linked to gastronomy.

Studies suggest that a first-of-its-kind osteoporosis drug lowers the risk of bone fractures better than some existing treatments and could soon add a more expensive but easier option to the booming market, The Associated Press reported.

Amgen Inc’s genetically engineered denosumab only requires two shots a year and could be approved for sale this fall.

Many osteoporosis patients stop taking other drugs due to side effects or frequent dosing. But doctors say denosumab’s high cost may be a drawback, due to competition with other cheaper and heavily advertised treatments currently on the market.

Dr. Sundeep Khosla, a professor and osteoporosis researcher at the Mayo Clinic, believes denosumab will find a particular niche where it will be used, but doesn’t see it taking over the market.

However, Khosla called it a “tour de force of modern molecular medicine” because it is potent and was designed specifically to block one pathway involved in the natural breakdown of bone cells.

Food and Drug Administration officials cited concerns about the drug’s increased rates of skin infections and some tumors, while outside advisers are expected to weigh the drug’s safety and effectiveness and recommend whether to approve it on Thursday.

Denosumab would have to compete against eight major types of pills and injected medicines, including estrogen and generic and brand-name Fosamax pills.

Many of the pills on the market must be swallowed once a day, week or month, the nasal spray must be inhaled daily, and one injection under the skin must be given daily.

The annual retail cost of most of those drugs can range from $385 for generic Fosamax, to roughly $1,250 for most brand-name pills, to $11,100 for injected Forteo. Genetically engineered drugs, made by altering a cell’s DNA or other genetic material, all cost more than $10,000 a year.

Data from IMS Health Global showed that sales of osteoporosis treatments, including hundreds of vitamin brands, hit nearly $8.4 billion last year among the nearly 10 million Americans living with osteoporosis.

Denosumab will pass the $1 billion annual sales threshold for blockbusters, but it’s unclear by how much, according to analyst Steve Brozak of WBB Securities.

Recent studies found denosumab caused eczema in some patients, and a dozen of the women got a serious skin infection, cellulitis, that sometimes required hospitalization for intravenous antibiotics.

All of these drugs carry some risks, said Dr. Lenore Buckley, a professor at Virginia Commonwealth University.

But Buckley said since denosumab affects the immune system, the long-term effects on cancer risk or immune function is still unknown. She expects that if the drug is approved, the FDA will require Amgen to track risks over time.

She added that the effectiveness of denosumab and existing drugs appears to plateau after two or three years.

Previous studies of osteoporosis drugs only measured changes in bone density, assumed to equate with lower fracture risk. But the newer studies also measure fracture rates.

However, independent experts say denosumab appears more effective at preventing spine fractures than three older pills – Fosamax, Actonel and Boniva – and calcitonin nasal sprays, which all use various pathways to slow down or kill cells called osteoclasts that break down bone.

Denosumab might have potential as an add-on to existing drugs to boost results, according to Dr. Jacob Warman, an osteoporosis expert at Brooklyn Hospital Center. He believes insurers who pay for multiple medicines for other conditions would cover it.

“The company has not yet set a price for the drug, but will try to keep it affordable,” said Amgen spokeswoman Kerry Beth Daly.

She added that the pricing will reflect denosumab’s twice-a-year dosing.

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On the Net:

• Amgen Inc

Don’t worry! Be happy! Optimistic women have a lower risk of developing heart disease or dying from any cause compared to pessimistic women, according to new research. Researchers also reported women with a high degree of cynical hostility “” harboring hostile thoughts toward others or having a general mistrust of people “” were at higher risk of dying, though their risk of developing heart disease was not altered.

“As a physician, I’d like to see people try to reduce their negativity in general,” Hilary A. Tindle, M.D., M.P.H., lead author of the study and assistant professor of medicine at the University of Pittsburgh was quoted as saying. “The majority of evidence suggests that sustained, high degrees of negativity are hazardous to health.”
 
In the largest study to date to examine the health effects of optimism and cynical hostility in post-menopausal women, researchers found that white and black American women’s attitudes are closely associated with their health.

Optimistic women had a 9 percent lower risk of developing heart disease and a 14 percent lower risk of dying from any cause after more than eight years of follow-up. Women with a high degree of cynical hostility, on the other hand, were 16 percent more likely to die during eight years of follow-up. “Prior to our work, the strongest evidence linking optimism and all-cause mortality was from a Dutch cohort, showing a more pronounced association in men,” Tindle said.

Tindle’s team studied 97,253 postmenopausal women (89,259 white, 7,994 black) ages 50 to 79 from the Women’s Health Initiative. The women were free of cancer and cardiovascular disease at the start of the study. Using the Life Orientation Test Revised Questionnaire to measure optimism and cynical hostility, researchers categorized scores into quartiles: high scores of 26 or more were considered optimists. Scores of 24-25 were considered mid-high; scores of 22-23 were considered mid-low; and scores below 22 were considered pessimists.
 
Optimists answered “yes” to questions like, “In unclear times, I usually expect the best.” Pessimists answered “yes” to questions like, “If something can go wrong for me, it will.”

Race also appeared to modify the relationship between optimism and death, with a stronger association seen in African-American women. Among African-American women, optimists had a 33 percent lower risk of death across eight years of follow-up, while among white women, optimists had a 13 percent lower risk of death.

Researchers found that optimists were more likely to be younger (especially among blacks), live in the Western United States, report higher education and income, be employed and have health insurance, and attend religious services at least once a week.
 
Optimists were less likely to have diabetes, high blood pressure, high cholesterol or depressive symptoms, smoke, be sedentary or have a high body mass index. However, the relationship between optimism and heart disease and death persisted even after considering all of these factors.

“This study is a very reasonable stepping stone to future research in this area,” said Tindle, “both on potential mechanisms of how attitudes may affect health, and for randomized controlled trials to examine if attitudes can be changed to improve health.”

SOURCE: Circulation: Journal of the American Heart Association, August 10, 2009

A new analysis suggests patients and physicians should rethink the pros and cons of limb-sparing surgery versus amputation for bone and soft tissue sarcomas of the lower limb.

Patients with tumors of the bone or soft tissue in their arms and legs require surgery to remove their cancer. To compare the costs and benefits of amputation compared with limb-sparing surgery in these patients, Canadian researchers Ronald Barr, M.D., M.B., Ch.B., of McMaster University and Jay Wunder, M.D., M.Sc., of the Mount Sinai Hospital and the University of Toronto, reviewed all published papers that examined limb-sparing surgery and also measured patients’ functional health and quality of life.

Their review found while limb-sparing surgery is generally as effective as amputation in ridding the patient of cancer, it tends to be associated with more complications. Surprisingly, these studies also show limb salvage does not provide a better quality of life for patients than amputation, particularly for patients with lower limb bone sarcomas.

Most studies found the differences in disability between patients who underwent amputation and those who had limb-sparing surgery are smaller than expected. In fact, many revealed no significant difference in psychological health and quality of life. However, there do appear to be greater advantages to limb-sparing surgery over amputation for surgical sites, such as the hip, that are located higher on the lower limb.

Some studies looked at the costs of amputation versus limb-sparing surgery. Surgical costs, the duration of rehabilitation, and the need for revisions are all greater for limb-sparing surgery. However, amputation carries longer term costs related to artificial limb manufacture, maintenance, and replacement.

The authors say additional research is needed to provide a thorough comparison of amputation and limb-sparing surgery in different types of patients with bone and soft tissue sarcomas. Dr. Wunder was quoted as saying, “Future studies that include function, health-related quality of life, economics, and stratification of patients by age will be useful contributions to decision-making . . . by patients, health care providers and administrators.”

SOURCE: Cancer, September 15, 2009

When it comes to raising their children, today’s parents are much more likely to show affection and to read to their children than their own parents were, according to researchers at Ohio State University who conducted a study of parenting practices across two generations.

The study found that mothers tend to follow the same practices their own mothers did, while fathers were less likely to use their own mothers as parenting role models.

The researchers looked at how often parents in the 1990s spanked, read to and showed affection to their children, and compared that to how these parents were treated by their own mothers. “We were surprised that mothers seem to learn a lot about the parenting role from their own mothers, but fathers don’t follow their mothers as much,” Jonathan Vespa, co-author of the study and doctoral student in sociology at Ohio State was quoted as saying.

“These fathers were growing up in the 70s and 80s and received much of their parenting from their mothers,” Vespa said. “Although more women were entering the workforce then, they still did the lion’s share of parenting and childcare.”

Fathers may have been more influenced by their dads, but the surveys used did not examine the fathers’ behavior. Vespa said, “We really need to learn a lot more about how fathers learn to parent.”

Vespa conducted the study with Elizabeth Cooksey, associate professor of sociology at Ohio State, and Canada Keck, a senior research associate at Ohio State’s Center for Human Resource Research.

The data came from the National Longitudinal Survey of Youth, a nationally representative survey conducted by Ohio State’s Center for Human Resource Research. Men and women aged 14 to 22 in 1979 were interviewed annually from 1979 to 1994, and once every two years from 1996 forward. A second survey followed all the children born to mothers in this original survey from birth through adulthood, as they became parents themselves.

In both generations, the researchers looked at how often parents spanked their children in the past week; how often they showed their child physical affection and praised them in the past week; and how often they read to their child in the past month.

Results showed for all three behaviors, the second generation of mothers closely followed what their mothers did. For example, mothers who were spanked at least once a week were nearly 50 percent more likely to spank their own children than mothers who weren’t spanked at all. Fathers who were spanked as children, however, were less likely to spank their own children. Only 28 percent of the second generation of fathers reported spanking their children, compared to 43 percent of mothers.

Another surprising finding was fathers who spanked their children also tended to show high levels of affection. “Some fathers might feel that being a strict disciplinarian is part of the way that fathers show affection to their children,” said Vespa. There was no such connection between affection and spanking for mothers.

Vespa said the results show some parenting practices are passed down from mother to mother ““ but only to a point. “If parents really just learned from their own parents, we wouldn’t witness such dramatic generational shifts as were seen in this study,” he said. “We need to look at the broader culture to find other sources of change that shape how parents learn to parent.”

SOURCE: Presented at the annual meeting of the American Sociological Association, San Francisco, August 9, 2009

At least one strain of the H5N1 avian influenza virus leaves survivors at significantly increased risk for Parkinson’s disease and possibly other neurological problems later in life, according to new research from St. Jude Children’s Research Hospital.

In the August 10 online early edition of the Proceedings of the National Academy of Sciences, researchers reported that mice which survived infection with an H5N1 flu strain were more likely than uninfected mice to develop brain changes associated with neurological disorders like Parkinson’s and Alzheimer’s diseases. Parkinson’s and Alzheimer’s involve loss of brain cells crucial to a variety of tasks, including movement, memory and intellectual functioning. The study revealed the H5N1 flu strain caused a 17 percent loss of the same neurons lost in Parkinson’s as well as accumulation in certain brain cells of a protein implicated in both diseases.

“This avian flu strain does not directly cause Parkinson’s disease, but it does make you more susceptible,” said Richard Smeyne, Ph.D., associate member in St. Jude Developmental Neurobiology. Smeyne is the paper’s senior author.

“Around age 40, people start to get a decline in brain cells. Most people die before they lose enough neurons to get Parkinson’s. But we believe this H5N1 infection changes the curve. It makes the brain more sensitive to another hit, possibly involving other environmental toxins,” Smeyne explained.

Smeyne noted the work involved a single strain of the H5N1 flu virus, the A/Vietnam/1203/04 strain. The threat posed by other viruses, including the current H1N1 pandemic flu virus, is still being studied.

Early indications are that the H1N1 pandemic strain carries a low neurologic risk, said Richard Webby, Ph.D., director of the World Health Organization Collaborating Center for Studies on the Ecology of Influenza in Animals and Birds, which is based at St. Jude. Webby, who is also an associate member of the St. Jude Department of Infectious Diseases, was not involved in the H5N1 study led by Smeyne.

This study also supports the theory that a hit-and-run mechanism is at work in Parkinson’s disease. The investigators believe the H5N1 infection sparks an immune response that persists long after the initial threat is gone, setting patients up for further devastating losses from a second hit, possibly from another infection, drug or environmental toxin. In this case, researchers believe the flu virus is the first hit that sets up development of Parkinson’s at a later time.

An estimated 4.1 million Americans, including 1 to 2 percent age 55 and older, have Parkinson’s. Many suspect both genetic and environmental factors play a role in its development. The disease is linked to the death of dopamine-secreting cells in an area of the midbrain known as the substantia nigra pars compacta (SNpc). Dopamine is a neurotransmitter responsible for stimulating the motor neurons that control movement. Parkinson’s is usually diagnosed after individuals lose 70 to 80 percent of the dopamine-producing cells. Treatment is available, but there is no cure.

Flu is primarily a respiratory disease, but indirect evidence dating back to 1385 links it to neurological problems, including the brain inflammation known as encephalitis. The association between flu and brain disorders like Parkinson’s was strengthened by an outbreak of encephalitic lethargic, also known as von Economo’s encephalopathy, following the 1918 Spanish flu pandemic. Some of those patients developed Parkinson’s symptoms.

St. Jude researchers launched this study nearly three years ago in response to the threat posed by avian flu. Smeyne said there was concern about possible long-term neurological risks facing H5N1 survivors.

Previous studies had isolated H5N1 in the nervous system. But this is the first to show the path the virus takes to enter the brain as well as the aftermath of the infection. Smeyne said the virus’ path from the stomach through the nervous system and into the brain is reminiscent of how Parkinson’s unfolds.

In this study, mice were infected with an H5N1 flu strain isolated in 2004 from a patient in Vietnam. Robert Webster, Ph.D., said the strain remains the most virulent of the avian flu viruses. Webster, a co-author of the study, holds the Rose Marie Thomas Chair in Infectious Diseases at St. Jude.

About two-thirds of the mice developed flu symptoms, primarily weight loss. After three weeks there was no evidence of H5N1 in the nervous systems of the mice that survived.

But the inflammation the infection triggered within the brain continued for months. It was similar to inflammation associated with inherited forms of Parkinson’s. Although the tremor and movement problems disappeared as flu symptoms eased, investigators reported that 60 days later mice had lost roughly 17 percent of dopamine-producing cells in SNpc, a structure found in the midbrain.

Researchers also found evidence that the avian flu infection led to over-production of a protein found in the brain cells of individuals with both Alzheimer’s and Parkinson’s diseases. The protein, alpha-synuclein, collected in H5N1-infected cells throughout the brain, including the midbrain where key dopamine-producing cells are located. There was little protein accumulation in the brain cells of uninfected mice.

The study marks the first time scientists were able to naturally trigger the protein build-up in an experimental Parkinson’s system. “The virus activates this protein,” Smeyne explained.

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On The Net:

St. Jude Children’s Research Hospital

A new material developed at the University of Virginia ““ an oxygen nanosensor that couples a light-emitting dye with a biopolymer ““ simplifies the imaging of oxygen-deficient regions of tumors. Such tumors are associated with increased cancer aggressiveness and are particularly difficult to treat.

Oxygen nanosensors are powerful new research tools that one day may also be used for the diagnosis and detection of diseases and for planning treatment strategies.

The new material is based on poly(lactic acid), a biorenewable, biodegradable polymer that is safe for the body and the environment, and is easy and inexpensive to fabricate in many forms, including films, fibers and nanoparticles. It is useful for medical research as well as environmental research, sustainable design and green products, too.

The versatile sensor material is the result of research combining green chemistry with nanotechnology, and is reported in the current online edition of the journal Nature Materials.

Chemists at the University of Virginia developed the material and consulted with cancer researchers at the U.Va. Cancer Center and Duke University Medical Center to determine possible applications.

Guoqing Zhang, a U.Va. chemistry doctoral candidate, working with Cassandra Fraser, a U.Va. chemistry professor, synthesized the new material by combining a corn-based biopolymer with a dye that is both fluorescent and phosphorescent. The phosphorescence appears as a long-lived afterglow that is only evident under low oxygen or oxygen-free conditions.

Zhang devised a method to adjust the relative intensities of short-lived blue fluorescence and long-lived yellow phosphorescence, ultimately creating a calibrated colorful glow that allows visualization of even minute levels of oxygen. The biomaterial displays its oxygen-sensitive phosphorescence at room or body temperature, making it ideal for use in tissues.

“We were amazed at how easy the material was to synthesize and fabricate as films and nanoparticles, and how useful it is for measuring low oxygen concentrations,” Fraser said.

“It is based on a bio-friendly material,” added Zhang. “It is safe for the body and the environment, and so we realized it could have applications not just for medical research and developing improved disease treatments, but also for new sustainable technologies.”

Cancer researchers at Duke quickly realized that the new material could be particularly useful for real-time and extended-time spatial mapping of oxygen levels in tumors. This is important because a lack of sufficient oxygen in tumors ““ called “hypoxia” ““ is a major source of resistance to radiation and chemotherapy treatment, and promotes a greater degree of malignancy.

“We have found that these nanoparticles were directly applicable to our existing tumor models,” said Greg Palmer, assistant professor of radiation oncology at Duke University Medical Center. “This technology will enable us to better characterize the influence of tumor hypoxia on tumor growth and treatment response.”

Researchers and clinicians have long sought effective ways to locate and map low-oxygen areas in the body to better understand normal and disease processes. Presently, there are no simple, easy or inexpensive methods, preclinical or clinical, for generating oxygen maps of tumors and surrounding tissues with good spatial and temporal resolution.

“The method developed here holds great promise for being able to perform measurements of tumor hypoxia cost-effectively,” said study co-author Mark Dewhirst, a professor of radiation oncology, pathology and biomedical engineering at Duke. “This kind of tool could greatly increase our knowledge about methods to eliminate tumor hypoxia, which could lead to more effective treatments.”

“Tumors that have insufficient oxygen tend to be more likely to spread from the primary site to other parts of the body,” added Michael Weber, director of U.Va.’s Cancer Center. “Despite the overall importance of tumor hypoxia, it is very difficult to measure directly and most methods that are available are very expensive.”

The new material currently is being used in preclinical studies to gain insight into cancer biology and treatment response, which could be useful for drug development and testing.

“This technology enables entirely new insights to be obtained, allowing imaging of tumor hypoxia on the scale of tumor cells and small blood vessels,” Palmer said.

Eventually the material could be used as an injectable nanosensor, potentially providing continual data on oxygen levels, biological processes and therapy responsiveness.

Hypoxia also is linked to cardiovascular disease, stroke and diabetes, so the material developed by Zhang and Fraser could have applications in several areas of medicine.

Applications for the light-emitting biomaterial beyond medicine include molecular probes for cell biology, imaging agents for visualizing fluid and aerodynamics, and oxygen sensors for food and drug packaging, tamper resistant seals, and environmental monitoring, such as measuring oxygen levels in bodies of water.

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On The Net:

University of Virginia

Primary sclerosing cholangitis (PSC) is an idiopathic chronic cholestatic inflammatory liver disease characterized by diffuse fibrosing inflammation of intra- and/or extrahepatic bile ducts, resulting in bile duct obliteration, biliary cirrhosis, and eventually hepatic failure. One of the most common symptoms at the time of presentation of PSC is mild to severe abdominal pain localized in the right upper quadrant. However, the mechanisms responsible for the abdominal pain in PSC are not fully understood.

A research team led by Karouk Said from Karolinska University Hospital addressed this question. Their study will be published on July 28, 2009 in the World Journal of Gastroenterology.

In this study, 20 patients with PSC and 10 healthy subjects were investigated. Gallbladder fasting volume, ejection fraction and residual volume after ingestion of a test meal were compared in patients with PSC and healthy controls using magnetic resonance imaging. Symptoms, thickness and contrast enhancement of the gallbladder wall and the presence of cystic duct strictures were also assessed.

Median fasting gallbladder volume in patients with PSC [67 (19-348) mL] was twice that in healthy controls [32 (16-55) mL] (P < 0.05). The median postprandial gallbladder volume in patients with PSC was significantly larger than that in healthy controls (P < 0.05). There was no difference in ejection fraction, gallbladder emptying volume or mean thickness of the gallbladder wall between PSC patients and controls. Contrast enhancement of the gallbladder wall in PSC patients was higher than that in controls; (69% ± 32%) and (42% ± 21%) (P < 0.05). No significant association was found between the gallbladder volumes and occurrence of abdominal pain in patients and controls.

This concluded that PSC patients have increased fasting gallbladder volume. Gallbladder mucosal dysfunction secondary to chronic cholecystitis, may be a possible mechanism for increased gallbladder volume. Gallbladder size or emptying does not seem to be involved in the development of abdominal pain in patients with PSC.

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On The Net:

World Journal of Gastroenterology

Blood transfusions for hospitalized cardiac patients should be a last resort because they double the risk of infection, U.S. researchers found.

The study, published in BMC Medicine, found the risk of death following cardiac blood transfusions increased four-fold.

The analysis of 30-day outcomes for nearly 25,000 Medicare coronary artery bypass graft surgery patients from 2003-2006 in 40 Michigan hospitals found transfusion practices vary substantially among hospitals.

Study co-author Dr. Neil Blumberg of the University of Rochester Medical Center in New York said the finding suggests a number of doctors may be doing what they were trained to do — avoiding anemia and helping oxygen delivery — rather than what has been clinically proven to be necessary.

Blood transfusions are certainly necessary in life-threatening situations, Blumberg says in a statement. But this study and other studies confirm they should be a last resort, not a first resort, as they often are.

Blumberg suggests when a transfusion is necessary the chances of infection and inflammation may be lowered through leukoreduction — removing the donor’s white blood cells from the blood.

A new study suggests that blood transfusions for hospitalized cardiac patients should be a last resort because they double the risk of infection and increase by four times the risk of death.

The analysis of nearly 25,000 Medicare patients in Michigan also showed that transfusion practices after heart surgery varied substantially among hospitals, a red flag that plays into the health care reform debate.

A wide variation in care is a hot-button issue, as lawmakers and health reform experts discuss the best ways to address the variations. Some experts believe the country needs a system of medical guidelines, supported by scientific evidence, to aid doctors in decision-making. In fact, the Institute of Medicine has called for a national initiative of comparing the benefits and harms of certain methods to improve the delivery of care — an effort referred to by health-care insiders as “comparative effectiveness” research.

Blood transfusion is an area that could be well served with stronger, research-based guidelines, since the current clinical practice is all over the map, said study co-author Neil Blumberg, M.D., professor of Pathology and Laboratory Medicine and director of Transfusion Medicine at the University of Rochester Medical Center.

“Doctors are simply doing what they were trained to do, but it turns out that their actions are more harmful than helpful in many cases,” Blumberg said. “This is an instance in which clinical practice got way ahead of research. And changing the liberal use of transfusions is going to be difficult despite the evidence showing it is usually not essential.”

The study was published July 31, 2009 in the journal, BMC Medicine. It was designed to assess patient outcomes as well as hospital variation in blood use.

Blumberg and lead author Mary Rogers, Ph.D., of the University of Michigan Health System, analyzed patient records in 40 hospitals, from admission to 30 days after discharge. All had received coronary artery bypass graft surgery from 2003 to 2006. They found that 30 percent of variation in transfusion practices seemed to be due to widely varied practices among hospital sites.

Also, blood use among women patients ranged from 72.5 percent to 100 percent, and blood use among men varied from about 50 percent to 100 percent. Transfusions with donor blood were associated with infections of the genitourinary system, respiratory tract, bloodstream, digestive tract and skin, the study said.

The risk of death in the hospital was nearly 5 times greater among patients who received a blood transfusion, and the risk of death in the next 30 days was nearly three times greater. Some of the risk may’ve been due to the underlying condition that led to transfusion but an increasingly convincing body of evidence demonstrates that some of the effect is almost certainly due to the transfusion itself, Blumberg said.

Blood transfusions are extremely common in the United States. Some of the typical reasons for transfusions include prevention of anemia and improving oxygen delivery in heart failure.

Blumberg has been a long-time advocate for fewer transfusions and, when they are necessary, for using blood from which the donor’s white cells have been removed. This process, called leukoreduction, is believed to diminish the chances of infection and inflammation, research has shown.

“Blood transfusions are certainly necessary in life-threatening situations,” Blumberg said. “But this study and other studies confirm they should be a last resort, not a first resort, as they often are.”

For decades the URMC has been a leader in the study of blood transfusions, and Strong Memorial Hospital at URMC was among the first in the country to begin using leukoreduced blood for all its patients.

More recently, a team at Strong began to further refine the guidelines for blood transfusion. As a result the hospital has already seen a 10 to 15 percent drop in transfusions during the past six months. The improvement program is still in its early stages, and Blumberg said they will closely monitor the use of transfusions at Strong in the coming months.

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University of Rochester Medical Center

Scientists at the University of California, San Diego School of Medicine have demonstrated the ability to correctly re-wire connections to the spinal cord after spinal cord injury.

Sensory systems of the body send axons ““ long, slender projections of the neuron that function as wires ““ into the spinal cord to convey information regarding touch, position, and pain. Many sensory axons are covered by an insulating myelin sheath, which helps these impulses travel efficiently to the brain.

In certain spinal cord injuries, the axons are severed and the myelin sheath damaged. Loss of these systems results in the inability to feel or sense the body. The axons can no longer link to their targets in the brain, which blocks the electrical impulses from reaching the central nervous system.

In the last few years, researchers have shown that the severed wires, or axons, of the spinal cord can be induced to regenerate into and beyond sites of experimental spinal cord injury. But a key question has been how these regenerating axons, on reaching the end of an injury site, can be guided to a correct cell target when faced with millions of potential targets. Further, can regenerating axons form functional, electrical connections called synapses?

“The ability to guide regenerating axons to a correct target after spinal cord injury has always been a point of crucial importance in contemplating translation of regeneration therapies to humans,” senior author Mark Tuszynski, MD, PhD, professor of neurosciences and director of the Center for Neural Repair at UC San Diego, and neurologist at the Veterans Affairs San Diego Health System was quoted as saying. “While our findings are very encouraging in this respect, they also highlight the complexity of restoring function in the injured spinal cord.”

The UC San Diego study looked at regenerating sensory axons in rat models of spinal cord injury. The researchers showed that regenerating axons can be guided to correct targets using a type of chemical hormone called a growth factor. The team utilized a nervous system growth factor called neurotrophin-3 (NT-3), to guide regenerating sensory axons to the appropriate target and to support synapse formation.

Regeneration required two other treatments at the same time: placing a cell bridge in the spinal cord injury site to support axon growth, and a “conditioning” stimulus to the injured neuron that turned on regeneration genes for new growth.

When the growth factor was placed in the correct target as a guidance cue, axons regenerated into it and formed synapses. When the growth factor was placed in the wrong target, axons still followed the growth factor and grew into that region.

Using high-resolution imaging systems, the scientists showed that regenerating axons guided to the correct cell formed synapses that were precisely on target. These axons contained rounded vesicles ““ small packets at the end of the axon, packed with the chemical messengers needed to support electrical activity in the newly formed circuit.
However, the connections were not electrically active.

Additional study revealed the likely reason for this was that the regenerating axons were not covered in myelin, the insulating material of the nervous system. “Restoring axonal circuitry is complex, requiring several concurrent therapies to achieve axonal regeneration into and beyond a spinal cord lesion site,” said Tuszynski. “But, just as an electrical circuit needs insulation so it doesn’t short-circuit, it appears that these regenerating axons require restoration of the myelin sheath to ultimately restore function.” This will be the next step in the team’s research.

SOURCE: Nature Neuroscience, August 2, 2009

Though it may seem counterintuitive, given that the most bothersome symptom of leukemia is extreme fatigue, a team of researchers has shown that physical activity can significantly improve symptoms of fatigue and depression, increase cardiovascular endurance and maintain quality of life for adult patients undergoing treatment for leukemia.

Ten patients undergoing treatment participated in the EQUAL (Exercise and Quality of Life in Leukemia/ Lymphoma Patients) study at the University of North Carolina, Chapel Hill, Department of Exercise and Sport Science and UNC Lineberger Comprehensive Cancer Center. Each patient was provided with specially-treated exercise equipment to minimize the risk of infection. Patients participated in individualized exercise sessions while in the hospital for the 3- to 5-week induction phase of leukemia treatment.

The exercise prescription included aerobic and resistance exercises, core exercises, and light stretches tailored to the patient’s level of fitness and leukemia symptoms. Upon their discharge from the hospital, each patient received an aerobic-based exercise prescription for their two-week home recovery period.

Before and after the exercise program, the researchers measured resting heart rate, blood pressure and hemoglobin, body weight and height, body composition, cardiorespiratory fitness and muscular endurance. Researchers also administered psychological tests to assess fatigue, depression and quality of life. Blood samples were taken at baseline, mid, and at the conclusion of the study, and analyzed for biomarkers of inflammation.

“We found that the patients experienced significant reduction in total fatigue and depression scores, as well as improved cardiorespiratory endurance and maintenance of muscular endurance,” Claudio Battaglini, Ph.D., assistant professor of exercise and sport science and UNC Lineberger member was quoted as saying.

“This is important because of the numerous side-effects related to cancer treatment, and particularly leukemia treatment, which requires confinement to a hospital room for 4-6 weeks to avoid the risk of infection,” he added. “We have demonstrated that these patients not only can complete an exercise program in the hospital but that they may receive both physiological and psychological benefits that could assist in their recovery.”

A follow-up study, EQUAL phase II, is now in development. This study will consist of a randomized clinical-controlled trial to assess the effects of an individualized exercise prescription in acute leukemia patients vs. a group of leukemia patients receiving treatment with no exercise component. If the results are positive, the research team will develop a multi-site research program involving other cancer centers throughout North Carolina and the United States.

SOURCE:  Integrative Cancer Therapies, August 3, 2009

Critics are saying that big spending on Tamiflu vaccines and face masks to combat the swine flu pandemic is an imbalanced fight.

Critics opposed to the spending strategy say that it is imbalanced and is only protecting the rich countries against H1N1, not the poor nations.

Others say that billions of dollars are being spent on a disease that is no more lethal than the seasonal flu. 

“It’s another example of the gap between the north and south,” said Michel Kazatchkine, executive director of the Global Fund to Fight AIDS, Tuberculosis and Malaria.

“In the (wealthy countries of the) north, vaccines are being stockpiled, antiviral drugs are being stockpiled, all with the risk that these things will not be effective,” he said in an interview with AFP.

“In the (poor countries of the) south, there are neither diagnostics nor treatment.”

According to the AFP, pharmaceutical giants are saving vaccines and antiviral drugs for poor countries under a United Nations strategy through gifts and donations.

However, UN Secretary General Ban Ki-moon and World Health Organization (WHO) chief Margaret Chan say that they are worried of a shortfall.

They say that billions are being drawn up to help poor countries have a better defense against the virus.

“Manufacturing capacity for influenza vaccines is finite and woefully inadequate for a world of 6.8 billion people, nearly all of whom are susceptible to infection by this entirely new and highly contagious virus,” Chan said on July 14.

Others question whether spending on the swine flu is morally right.

About 11,500 people are killed everyday from AIDS, malaria and TB.  Swine flu has taken about 816 lives since April, according to a WHO tally.

Marc Gentilini, a professor of infectious disease and former head of the French Red Cross, says that the swine flu is a “pandemic of indecency,” adding that rich-world politicians opened the financial gates under scrutiny of critics saying not enough was being done.

He said that France spent $1.4 billion to buy enough vaccinations for its 60 million population.

According to the AFP, the vaccine is currently undergoing testing for safety and effectiveness, and it will be available in the upcoming months.

It is still not known whether the vaccine will provide a shield if the virus mutates into a more deadly form.

“A billion euros for a vaccine with so many unknowns, it’s pure haste,” said Gentilini. “This is money that can be better used elsewhere. It’s ethically unacceptable.”

People for the big spending on the vaccine bring up the pandemics in the 20th century, which was during a time that the “Spanish flu” took millions of lives between 1918-1919.

New York microbiologists Taia Wang and Peter Palese wrote to the journal Cell a day after the WHO declared the swine flu pandemic.  They said there needs to be a sense of proportion.

They said that there were little signs that the circulating virus will cause a pandemic on the scale of the past.  They added that vaccines, antivirals and antibiotics are all weapons that doctors did not have in 1918.

“Around 80,000 children die from malaria and more than twice that number of diarrhoeal diseases worldwide in any four-week period,” they said.

“On a scale of global health crises, the current H1N1 swine influenza outbreak would seem to rank low on the list. Why, then, has this outbreak caused such alarm?”

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• Global Fund to Fight AIDS, Tuberculosis and Malaria
• WHO
• CDC

Older diabetic patients who take antipsychotic medications appear to have an increased risk of hospitalization for hyperglycemia (elevated blood glucose level), especially soon after beginning treatment, according to a new report.

The antipsychotic drugs prescribed for older adults with dementia may be associated with adverse effects, including Parkinson’s disease symptoms, stroke and diabetes. “The risk of diabetes may be partly related to chronic effects of the weight gain associated with antipsychotic agents,” the authors were quoted as saying. “However, case reports of acute hyperglycemia after the initiation of therapy with these drugs suggest that they may also be associated with acute glycemic [blood glucose level] changes.”

Lorraine L. Lipscombe, M.D., M.Sc., of the Institute for Clinical Evaluative Sciences, University of Toronto and Women’s College Research Institute at Women’s College Hospital, Toronto, Ontario, Canada, and colleagues studied 13,817 individuals age 66 and older, all diabetics who began treatment with antipsychotics between April 2002 and March 2006. Each patient who was hospitalized for hyperglycemia during the observation period was considered a case and was matched with up to 10 control patients of the same age and gender who were not hospitalized during this time period. The researchers then compared the likelihood of hyperglycemia among those who were currently taking antipsychotic medications to those who had discontinued antipsychotic medications for more than 180 days.

Of the total group, 11 percent were hospitalized for hyperglycemia. Those who were currently taking antipsychotic drugs had a higher risk of hospitalization than those who had stopped the medications for more than 180 days. The risk was highest among those who were just starting antipsychotic drug treatment.

“Our study indicates that the initiation of antipsychotic therapy represents a critical period during which seniors with diabetes are particularly vulnerable to metabolic decompensation [failure of the metabolic system to function adequately],” the authors wrote. “The new use of both atypical [newer] and typical antipsychotic drugs was associated with a significant increase in hospitalizations for hyperglycemia, which appeared independent of baseline diabetes treatment and was strikingly high during the initial period of antipsychotic therapy.”

Previous evidence suggests the neurotransmitter dopamine plays a role in regulating blood glucose levels. First-time antipsychotic users may experience an acute disruption in this system, leading to hyperglycemic episodes, the authors note. However, further studies are needed to confirm the cause and to identify the mechanisms involved.

“In the meantime, other options to manage behavioral symptoms of dementia should be considered among older persons with diabetes,” the authors conclude. “Patients and their families should be alerted to observe for signs of glycemic decompensation when treatment with an antipsychotic agent is initiated, and enhanced glucose monitoring is recommended for all patients for whom an antipsychotic drug is prescribed, particularly after treatment initiation.”

SOURCE:  Archives of Internal Medicine, July 27, 2009

The National Institutes of Health (NIH) said on Tuesday it had halted a trial of the drug sildenafil for patients with sickle cell disease, saying the drug caused serious medical problems.

The trial was testing the safety and effectiveness of sildenafil, sold by Pfizer as Viagra and Revatio, as a treatment for pulmonary hypertension in patients with sickle cell disease, said the National Heart, Lung, and Blood Institute (NHLBI).

Patients without sickle cell disease taking the sildenafil — which is approved under the Revatio brand name to treat pulmonary hypertension in otherwise healthy adults — are not at risk, the NHLBI added.

The researchers found that 38 percent of patients taking Revatio had serious adverse effects such as painful sickle cell “crises”, compared with just 8 percent of patients taking a placebo.

“The increase in sickle cell medical problems is concern enough for us to stop this clinical trial to protect the safety of our participants,” NHLBI Director Dr. Elizabeth Nabel told Reuters.

“We will continue to look into the possible causes of these preliminary results,” she added.

“In the meantime, we encourage patients with sickle cell disease who are taking sildenafil for pulmonary hypertension to talk with their physicians about the potential risks and benefits of the medication and what actions they should consider, including whether to taper off this medication and how to best manage both sickle cell disease and pulmonary hypertension.”

“No deaths have been associated with the drug in the clinical trial,” said the NHLBI said in a statement.

Pulmonary hypertension is high blood pressure within the arteries that carry blood to the lungs.  The condition can cause heart failure and death. Sildenafil treats pulmonary hypertension by relaxing the blood vessels in the lungs so the blood can flow more easily.

Roughly 30 percent of those with sickle cell disease develop pulmonary hypertension, which can cause sudden death.

The U.S. Food and Drug Administration (FDA) has not approved sildenafil to treat pulmonary hypertension in patients with sickle cell disease, so the NHLBI was conducting a small trial to see if the drug would help these patients.

Sildenafil is currently sold under the name Viagra as a treatment for erectile dysfunction or impotence.

Shares of Pfizer were down 3.55 percent on Tuesday, closing at $16.03 on the New York Stock Exchange.

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The New York City health department is urging parents to beware of illegal teething products and other illegal health remedies.

Nancy Clark, assistant commissioner for the health department’s environmental disease prevention bureau, said the warning is in response to a reported case of potassium bromide poisoning in an infant, associated with the use of a locally purchased teething product called Monell’s Teething Cordial or Cordial de Monell para la Denticion.

Potassium bromide is a potent sedative found in Cordial de Monell, a product made in the Dominican Republic.

Immediate effects from potassium bromide ingestion may include sedation, troubled breathing, low blood pressure and coma, Clark said.

The product is sold illegally in New York City and is typically used for teething discomfort, colic and gastrointestinal symptoms such as stomach pain, constipation and vomiting in infants, Clark said.

Illegal teething products can be dangerous for children, Clark said in a statement. If your child has consumed any illegal teething product, whether bought locally, brought into the United States by a family member, or purchased over the Internet, call the Poison Control Center at 212-POISONS or 212 764-7667.

A team of researchers from Case Western Reserve University School of Medicine have solved the mystery of why some children are more susceptible to malaria infection and anemia. These novel findings suggest that some children who are exposed to Plasmodium falciparum (P. falciparum) malaria before birth become tolerant to the malaria parasites, or their soluble products. This tolerance, which persists into childhood, reduces the ability of the immune system to attack and destroy parasites and increases the susceptibility of these children to develop a malaria infection. It also increases their risk for anemia. The study, published in this week’s issue of the open access journal, PLoS Medicine, is led by Indu Malhotra, Ph.D., and Christopher King, M.D., Ph.D., professor of international health, medicine, and pathology, with their colleagues at the Center for Global Health and Diseases at the Case Western Reserve University School of Medicine and their Kenyan colleagues at the Kenya Medical Research Institute and Division of Vector Borne Diseases.

“This is the first time it has been shown why some children are more susceptible to malaria and anemia than other children,” says Dr. Indu Malhotra. “This study is timely given President Obama’s Global Health Initiative to assist developing countries to control malaria, one of the ‘big three’ diseases.”

The Case Western Reserve study, entitled, “Can Prenatal Malaria Exposure Produce an Immune Tolerant Phenotype?: A Prospective Birth Cohort Study in Kenya”, investigated how prenatal malaria exposure affects anti-malaria immunity in young children and their susceptibility to subsequent malaria infections. Little is known about how immunity to malaria develops in infants, a process which researchers must understand in order to design effective vaccines for children. In particular, it is unclear how a mother’s malaria infection affects a child’s acquisition of anti-malaria immunity.

From a pool of 586 Kenyan newborn babies, the researchers identified those children who had been exposed to P. falciparum malaria in utero. The researchers looked for malaria-specific immune responses in T cells in the newborn babies’ cord blood by measuring the production of cytokines, molecules that either activate or inhibit the immune system. Finally, they examined the infants biannually for three years to monitor the children’s immune responses, susceptibility to malaria infection and risk for anemia..

“These findings could have important implications for the design of malaria vaccines for use in areas where children are often exposed to malaria before birth and for the design of strategies for the prevention of malaria during pregnancy,” says Dr. Christopher King.

The babies were classified into three groups: “sensitized” ““ those babies whose cord blood cells produce activating cytokines in response to the malaria antigens; “exposed, not-sensitized” ““ babies whose bodies did not produce activating cytokines but made an inhibitory cytokine; and “not-exposed””“ babies born to mothers with no P. falciparum malaria infection at delivery.

In their first three years of life, the “exposed, not-sensitized” group had a 60 percent greater risk of malaria infection than the “not-exposed” group and a slightly higher risk of malaria infection than the “sensitized” group. They also had lower hemoglobulin levels, a sign of anemia, than the other babies. The T cells of “exposed, not-sensitized” children were less likely to make activating cytokines in response to malaria antigens.

In a PLoS Medicine Perspective article on this study, editorial board member, Lars Hviid, states that the research by Dr. King and colleagues “adds significantly to our understanding of prenatal exposure to P. falciparum antigens” and has “obvious clinical importance.”

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