Clear science for curious people
ScienceBlog.com
Writer at Science Blog

ScienceBlog.com

Contributor

Profile →

Health

Children born after assisted reproduction at greater risk of congenital malformations

Gothenburg, Sweden: Couples considering undergoing assisted reproductive technology (ART) treatment should be informed about the increased risk of congenital malformation posed by the use of ART, the annual conference of the European Society of Human Genetics will hear today (Monday). Dr. Géraldine Viot, a clinical geneticist at the Maternité Port Royal hospital, Paris, France, will say that she believed that most doctors working in ART clinics in France only told couples about such risks if they were asked specific questions. Dr. Viot and colleagues conducted a survey in 33 French centres registered for ART, around one third of the total number of clinics registered to perform ART procedures in France. All ART births from these clinics from 2003 to 2007 were included; 15 162 children in total. The study was the largest to date on this subject. Questionnaires were completed both by the parents and the paediatrician and the prevalence of malformations found compared with the data obtained from national registers and in published papers. "We found a major congenital malformation in 4.24% of the children", said Dr. Viot, "compared with the 2-3% that we had expected from previous published studies. This higher rate was due in part to an excess of heart diseases and malformations of the uro-genital system. This was much more common in boys. Among the minor malformations, we found a five times higher rate of angioma, benign tumours made up of small blood vessels on or near the surface of the skin. These occurred more than twice as frequently in girls than boys." However, the scientists say, their results are a long way from the 11% of major malformations that have been reported by some studies. "Given that our study is the largest to date, we think that our data are more likely to be statistically representative of the true picture", said Dr. Viot. The average age of the parents of children born with malformations was not statistically different from the other parents in the ART group. The origins of the malformations are probably multiple, says Dr. Viot. "We need more research in order to understand the relationship between embryo culture media, timing of embryo transfer, the effects of ovarian stimulation, the use of ICSI, where sperm is injected directly into the egg, freezing of gametes and embryos and these disorders. "We estimate that in France some 200 000 children have been born after ART and therefore a malformation rate of this magnitude is a public health issue. It is important that all doctors and also politicians are informed about this. We also need to follow up all children born after ART and to put much more effort into trying to understand which of the procedures involved is implicated in this problem." Dr. Viot and colleagues intend to follow up their work analysing a further 4000 questionnaires, from children born in 2008, and to look at the motor development of children born in 2003, who are now aged 7. "By following all these children we hope to understand more about not only what can go wrong after ART, but why it goes wrong", she said. "At a time when infertility is increasing and more and more couples need to use ART to conceive, it is vitally important that we find out as much as we can about what is causing malformations in these children, not only so that we can try to counteract the problem but also in order for health services to be able to plan for their future needs." The scientists are now trying to find out the origin of parental infertility for each child born after ART who has been affected by major malformation or epigenetic disorders. "With this knowledge, we can better establish the origin of the malformation and whether it is more likely to be related to parental infertility or the ART procedure itself", said Dr. Viot. "We already know that imprinting disorders -- where the mechanism in which gene expression depends on parental origin -- are clearly more frequent in our cohort than in the general population." Imprinting disorders are all acquired because of either a maternal or paternal deletion on a chromosome, through inheritance of both chromosomes of a pair from only one parent, through mutations in some imprinted genes, or because of loss or gain of methylation (a process which is normally removed during zygote formation and re-established through successive cell divisions during development. "The prevalence of the imprinting disorder Beckwith Wiedemann syndrome in our cohort is six times higher than we would expect in the general population, and for retinoblastoma the prevalence among ART children is 4.5 higher than in the general population", said Dr. Viot. "These results could be due to the effect of a number of different mechanisms. They could be due to the infertility itself, the ovarian stimulation for supernumerary oocyte production, the in vitro maturation of oocytes, the use of ICSI (direct injection of sperm), the culture media, the cryopreservation of gametes and embryos -- we just don't know at present. Finding this out will be a major step towards improving the health of children born after ART."

Jun 13, 2010

Earth & Environment

New CU-Boulder study indicates an ancient ocean may have covered one-third of Mars

A vast ocean likely covered one-third of the surface of Mars some 3.5 billion years ago, according to a new study conducted by University of Colorado at Boulder scientists. The CU-Boulder study is the first to combine the analysis of water-related features including scores of delta deposits and thousands of river valleys to test for the occurrence of an ocean sustained by a global hydrosphere on early Mars. While the notion of a large, ancient ocean on Mars has been repeatedly proposed and challenged over the past two decades, the new study provides further support for the idea of a sustained sea on the Red Planet during the Noachian era more than 3 billion years ago, said CU-Boulder researcher Gaetano Di Achille, lead author on the study. A paper on the subject authored by Di Achille and CU-Boulder Assistant Professor Brian Hynek of the geological sciences department appears in the June 13 issue of Nature Geoscience. Both Di Achille and Hynek are affiliated with CU-Boulder's Laboratory for Atmospheric and Space Physics. More than half of the 52 river delta deposits identified by the CU researchers in the new study -- each of which was fed by numerous river valleys -- likely marked the boundaries of the proposed ocean, since all were at about the same elevation. Twenty-nine of the 52 deltas were connected either to the ancient Mars ocean or to the groundwater table of the ocean and to several large, adjacent lakes, Di Achille said. The study is the first to integrate multiple data sets of deltas, valley networks and topography from a cadre of NASA and European Space Agency orbiting missions of Mars dating back to 2001, said Hynek. The study implies that ancient Mars probably had an Earth-like global hydrological cycle, including precipitation, runoff, cloud formation, and ice and groundwater accumulation, Hynek said. Di Achille and Hynek used a geographic information system, or GIS, to map the Martian terrain and conclude the ocean likely would have covered about 36 percent of the planet and contained about 30 million cubic miles, or 124 million cubic kilometers, of water. The amount of water in the ancient ocean would have formed the equivalent of an 1,800-foot, or 550-meter deep layer of water spread out over the entire planet. The volume of the ancient Mars ocean would have been about 10 times less than current volume of Earth's oceans, Hynek said. Mars is slightly more than half the size of Earth. The average elevation of the deltas on the edges of the proposed ocean was remarkably consistent around the whole planet, said Di Achille. In addition, the large, ancient lakes upslope from the ancient Mars ocean likely formed inside impact craters and would have been filled by the transport of groundwater between the lakes and the ancient sea, according to the researchers. A second study headed by Hynek and involving CU-Boulder researcher Michael Beach of LASP and CU-Boulder doctoral student Monica Hoke being published in Journal of Geophysical Research -- Planets -- which is a publication of the American Geophysical Union -- detected roughly 40,000 river valleys on Mars. That is about four times the number of river valleys that have previously been identified by scientists, said Hynek. The river valleys were the source of the sediment that was carried downstream and dumped into the deltas adjacent to the proposed ocean, said Hynek. "The abundance of these river valleys required a significant amount of precipitation," he said. This effectively puts a nail in the coffin regarding the presence of past rainfall on Mars." Hynek said an ocean was likely required for the sustained precipitation. "Collectively, these results support the existing theories regarding the extent and formation time of an ancient ocean on Mars and imply the surface conditions during the time probably allowed the occurrence of a global and active hydrosphere integrating valley networks, deltas and a vast ocean as major components of an Earth-like hydrologic cycle," Di Achille and Hynek wrote in Nature Geoscience. "One of the main questions we would like to answer is where all of the water on Mars went," said Di Achille. He said future Mars missions -- including NASA's $485 million Mars Atmosphere and Volatile Evolution mission, or MAVEN, which is being led by CU-Boulder and is slated to launch in 2013 -- should help to answer such questions and provide new insights into the history of Martian water. The river deltas on Mars are of high interest to planetary scientists because deltas on Earth rapidly bury organic carbon and other biomarkers of life and are a prime target for future exploration. Most astrobiologists believe any present indications of life on Mars will be discovered in the form of subterranean microorganisms. "On Earth, deltas and lakes are excellent collectors and preservers of signs of past life," said Di Achille. "If life ever arose on Mars, deltas may be the key to unlocking Mars' biological past." Hynek said long-lived oceans may have provided an environment for microbial life to take hold on Mars. The study was funded by NASA's Mars Data Analysis Program.

Jun 13, 2010

Health

OU researchers find way to prevent blindness in research model for retinitis pigmentosa

Researchers at the University of Oklahoma Health Sciences Center have found a way to use a radical new type of gene therapy to prevent blindness caused by retinitis pigmentosa, giving hope to the estimated 100,000 Americans who suffer from this debilitating disease. The study appears in the Journal of the Federation of American Societies for Experimental Biology (FASEB). The research, led by Muna Naash, Ph.D., at the University of Oklahoma Health Sciences Center, with collaborators in Cleveland and Buffalo, discovered a way to deliver known gene therapies directly to the light-sensitive cells affected by this disease. The discovery already is being used to develop new treatments for another disease -- macular degeneration, the leading cause of blindness in the United States. "I am thrilled about it. That's why we have been working so hard to get this as quickly as possible through the necessary experiments, so we can publish our findings and take it out to the patients," Naash said. "We hope the results of our study will be instrumental in generating a cure for the debilitating blindness associated with retinitis pigmentosa and other inherited and acquired retinal diseases. We want to give Oklahomans and others suffering from these diseases renewed independence and quality of life." Utilizing nanoparticle technology, scientists created a microscopic capsule capable of carrying genetic therapies to their destination inside cells of the retina. The tiny delivery vehicle is being tested with a variety of gene therapies in animal models with the potential of treating several diseases from bladder cancer to diabetes. The capsules have proven very effective, carrying therapies to the designated location in the eye within 15 minutes of delivery and spreading the genetic repair message quickly to nearby cells. "This is an incredible breakthrough in terms of being able to treat with gene therapy," said Robert E. Leonard, M.D., an ophthalmologist at the Dean McGee Eye Institute. "Outside of gene therapy, we are at a loss to be able to treat these patients, so this is incredibly important research. It's breathtaking, very exciting." Retinitis pigmentosa is an eye disease in which there is damage to the retina. The damage gets worse over time as side (peripheral) vision is gradually lost and may eventually lead to blindness. The disorder commonly runs in families and can be caused by a number of genetic defects with signs and symptoms often first appearing in childhood. Severe vision problems do not usually develop until early adulthood. The research on retinitis pigmentosa at the OU Health Sciences Center is supported by a grant from the National Eye Institute and the Foundation Fighting Blindness. For more information on retinitis pigmentosa, go online to www.nlm.nih.gov/medlineplus/ency/article/001029.htm.

Jun 11, 2010

Health

Limiting blood flow interruption during kidney surgery avoids chronic kidney disease

ROCHESTER, Minn. -- Interrupting the blood flow for more than 20 to 25 minutes during kidney cancer (http://www.mayoclinic.org/kidney-cancer/research.html) surgery leads to a greater risk for patients developing chronic kidney disease, a Mayo Clinic and Cleveland Clinic collaborative research team has found. The study was published today in the journal, European Urology. For the retrospective study, researchers analyzed outcomes of 362 patients with only one kidney who underwent surgery for renal cortical tumors at Mayo Clinic and Cleveland Clinic between 1990 and 2008. Using a technique called warm ischemia, surgeons kept the patient's kidneys at body temperature during the partial nephrectomy. Ischemia involves cutting off the blood supply to the kidney with clamps in order to control bleeding and to keep blood from obscuring the surgeon's view of the kidney. It also allows for precise closure of the urine collecting system and the surgical opening. The median ischemia time was 21 minutes in the study and the median age of patients was 62 years. Ischemia can cause tissue damage from a lack of oxygen and nutrients. Researchers found that each additional minute of warm ischemia is associated with a 5 to 6 percent increase in the odds of developing acute renal failure or reduced kidney functioning and is associated with a 6 percent increased risk of new onset Stage IV chronic kidney disease during long-term follow-up. "This is the largest evaluation of warm ischemia time in patients with a single kidney who are undergoing a partial nephrectomy, combining the experiences of the Mayo Clinic and Cleveland Clinic, both leaders in the field of kidney cancer," says R. Houston Thompson, M.D., (http://www.mayoclinic.org/bio/13623818.html) Mayo Clinic urologist and the study's primary investigator. "These results suggest that every minute counts when the renal arteries and veins are clamped. When planning for the surgery, surgeons should make efforts to minimize ischemia time, especially in situations where a person only has one kidney." "Historically, 30 minutes was considered the maximum safe duration of warm ischemia during partial nephrectomy, and other retrospective clinical studies have suggested that warm ischemia for 40 to 55 minutes is safe," says Dr. Thompson. "However, these studies included patients with two kidneys, which could mask the true effects of ischemia on renal function. "Because each additional minute of warm ischemia invites the risk for chronic kidney problems, if longer ischemic times are unavoidable, techniques such as ice slush (cold ischemia) should be considered." The researchers stress that the study's results do not have implications for patients treated with cold ischemia. Collaboration Collaborators include Brian Lane, M.D.; Amr Fergany, M.D. and Steven Campbell, M.D. with the Glickman Urological Institute, Cleveland Clinic Foundation; Christine Lohse, Bradley Leibovich, M.D., (http://www.mayoclinic.org/bio/12144681.html); Igor Frank, M.D., (http://www.mayoclinic.org/bio/12529231.html) and Michael Blute, M.D., all of Mayo Clinic; and Inderbir Gill, M.D., Keck School of Medicine, University of Southern California. To request an appointment at Mayo Clinic, please call 480-422-1490 for the Arizona campus, 904-494-6484 for the Florida campus, or 507-216-4573 for the Minnesota campus. About Mayo Clinic For more than 100 years, millions of people from all walks of life have found answers at Mayo Clinic. These patients tell us they leave Mayo Clinic with peace of mind knowing they received care from the world's leading experts. Mayo Clinic is the first and largest integrated, not-for-profit group practice in the world. At Mayo Clinic, a team of specialists is assembled to take the time to listen, understand and care for patients' health issues and concerns. These teams draw from more than 3,700 physicians and scientists and 50,100 allied staff that work at Mayo Clinic's campuses in Minnesota, Florida, and Arizona; and community-based providers in more than 70 locations in southern Minnesota, western Wisconsin and northeast Iowa. These locations treat more than half a million people each year. To best serve patients, Mayo Clinic works with many insurance companies, does not require a physician referral in most cases and is an in-network provider for millions of people. To obtain the latest news releases from Mayo Clinic, go to www.mayoclinic.org/news. For information about research and education, visit www.mayo.edu. MayoClinic.com (www.mayoclinic.com) is available as a resource for your general health information. VIDEO ALERT: A video interview with Dr. R. Houston Thompson describing the research is available on the News Blog (http://newsblog.mayoclinic.org/2010/06/11/limiting-blood-flow-interruption-during-kidney-surgery-helps-avoid-chronic-kidney-disease/).

Jun 11, 2010

Earth & Environment

New strain of bacteria discovered that could aid in oil spill, other environmental cleanup

CORVALLIS, Ore. -- Researchers have discovered a new strain of bacteria that can produce non-toxic, comparatively inexpensive "rhamnolipids," and effectively help degrade polycyclic aromatic hydrocarbons, or PAHs -- environmental pollutants that are one of the most harmful aspects of oil spills. Because of its unique characteristics, this new bacterial strain could be of considerable value in the long-term cleanup of the massive Gulf Coast oil spill, scientists say. More research to further reduce costs and scale up production would be needed before its commercial use, they added. The findings on this new bacterial strain that degrades the PAHs in oil and other hydrocarbons were just published in a professional journal, Biotechnology Advances, by researchers from Oregon State University and two collaborating universities in China. OSU is filing for a patent on the discovery. "PAHs are a widespread group of toxic, carcinogenic and mutagenic compounds, but also one of the biggest concerns about oil spills," said Xihou Yin, a research assistant professor in the OSU College of Pharmacy. "Some of the most toxic aspects of oil to fish, wildlife and humans are from PAHs," Yin said. "They can cause cancer, suppress immune system function, cause reproductive problems, nervous system effects and other health issues. This particular strain of bacteria appears to break up and degrade PAHs better than other approaches we have available." The discovery is strain "NY3" of a common bacteria that has been known of for decades, called Pseudomonas aeruginosa. It was isolated from a site in Shaanxi Province in China, where soils had been contaminated by oil. P. aeruginosa is widespread in the environment and can cause serious infections, but usually in people with health problems or compromised immune systems. However, some strains also have useful properties, including the ability to produce a group of "biosurfactants" called rhamnolipids. A "surfactant," technically, is a type of wetting agent that lowers surface tension between liquids -- but we recognize surfactants more commonly in such products as dishwashing detergent or shampoo. Biosurfactants are produced by living cells such as bacteria, fungi and yeast, and are generally non-toxic, environmentally benign and biodegradable. By comparison, chemical surfactants, which are usually derived from petroleum, are commonly toxic to health and ecosystems, and resist complete degradation. Biosurfactants of various types are already used in a wide range of applications, from food processing to productions of paints, cosmetics, household products and pharmaceuticals. But they also have uses in decontamination of water and soils, with abilities to degrade such toxic compounds as heavy metals, carcinogenic pesticides and hydrocarbons. Although the type of biosurfactant called "rhamnolipids" have been used for many years, the newly discovered strain, NY3, stands out for some important reasons. Researchers said in the new study that it has an "extraordinary capacity" to produce rhamnolipids that could help break down oil, and then degrade some of its most serious toxic compounds, the PAHs. Rhamnolipids are not toxic to microbial flora, human beings and animals, and they are completely biodegradable. These are compelling advantages over their synthetic chemical counterparts made from petroleum. Even at a very low concentration, rhamnolipids could remarkably increase the mobility, solubility and bioavailability of PAHs, and strain NY3 of P. aeruginosa has a strong capability of then degrading and decontaminating the PAHs. "The real bottleneck to replacing synthetic chemicals with biosurfactants like rhamnolipid is the high cost of production," Yin said. "Most of the strains of P. aeruginosa now being used have a low yield of rhamnolipid. But strain NY3 has been optimized to produce a very high yield of 12 grams per liter, from initial production levels of 20 milligrams per liter." By using low-cost sources of carbon or genetic engineering techniques, it may be possible to reduce costs even further and scale up production at very cost-effective levels, researchers said. The rhamnolipids produced by NY3 strain appear to be stable in a wide range of temperature, pH and salinity conditions, and strain NY3 aggressively and efficiently degrades at least five PAH compounds of concern, the study showed. It's easy to grow and cultivate in many routine laboratory media, and might be available for commercial use in a fairly short time. Further support to develop the technology is going to be sought from the National Science Foundation. "Compared to their chemically synthesized counterparts, microbial surfactants show great potential for useful activity with less environmental risk," the researchers wrote in their report. "The search for safe and efficient methods to remove environmental pollutants is a major impetus in the search for novel biosurfactant-producing and PAH-degrading microorganisms." Collaborating on this research were scientists from Xi'an University of Architecture and Technology and Nanjing Agricultural University in China. Editor's Note: A copy of the professional publication on which this story is based is available on request from OSU News and Communication Services, 541-737-0787 or [email protected]

Jun 11, 2010

Health

Directly observed HIV treatment by patient-nominated treatment supporter improves survival

When applied to HIV care, the community-based model of directly observed therapy (DOT) has no effect on virologic outcomes, but significantly improves patient survival. This is according to researchers at the Johns Hopkins Bloomberg School of Public Health, in collaboration with colleagues at University of Cape Town, South Africa, who conducted the first randomized controlled trial of patient-nominated treatment-supporters providing partial DOT in resource-limited settings. The researchers found that mortality rates were lower among DOT patients than among self-monitored antiretroviral therapy (ART). The results are featured in the June 1, 2010, issue of AIDS. Directly observed therapy (DOT) is a treatment strategy commonly used in tuberculosis control programs, in which a health care worker ensures that medication is taken by patients at health care facilities. Previous observational studies suggested the effectiveness of community health supporters (friends or family members) performing DOT antiretroviral therapy as a strategy to improve adherence, but data from randomized trials were previously lacking. "Community DOT-ART showed no effect on virologic outcomes, but was associated with greater CD4 cell count increases at 6-month follow up," said Jean B. Nachega, MD, PhD, MPH, lead author of the study, associate scientist in the Bloomberg School's Department of International Health. Nachega is also, professor of medicine and director of the Center for Infectious disease at Stellenbosch University, Cape Town, South Africa.) "More importantly, there were 20 deaths in the control group compared to 9 deaths among those who received the intervention, and mortality was independently associated with the study arm in multivariate Cox regression analyses. This survival benefit was not fully explained by improved adherence, virologic or immunologic outcomes." For the study, researchers analyzed data from 274 adult patients initiating antiretroviral therapy (ART) at a public HIV clinic in Cape Town, South Africa. Patients were randomized to treatment-supporter DOT-ART or self -administered ART. In the DOT group, patients selected someone from their own personal network such as a family member or friend to observe at least one medication dose every day and provide support. DOT-ART patients and supporters received baseline and follow-up training and monitoring. Researchers defined the primary endpoints as the number of patients with undetectable HIV viral loads (fewer than 400 copies/ml) and a mean change in CD4 cell counts at 6, 18, 12 and 24 months. Secondary endpoints were pill count adherence, new or recurrent AIDS defining illness and all-cause mortality. "The `social capital´ provided by a trusted patient-nominated treatment supporter (e.g. material and emotional support, health care utilization, etc.), may have contributed to save lives, regardless of the DOT component of our intervention" said Nachega. "Moving forward, there is a critical need to identify and assess additional community-based interventions to improve outcomes of HIV patients worldwide. We recommend these community-based DOT-ART interventions be large enough to detect meaningful clinical and public health differences that improve patients' conditions and save lives. In addition, they should target patients with documented poor adherence and collect both qualitative and quantitative outcomes." "Randomized Controlled Trial of Trained Patient-Nominated Treatment Supporters Providing Partial Directly Observed Antiretroviral Therapy" was written by Jean B. Nachega, Richard E. Chaisson, Rene Goliath, Anne Efron, Mohammad A. Chaudhary, Malathi Ram, Chelsea Morroni, Hennie Schoeman, Amy R. Knowlton and Gary Maartens. The research was supported in part by grants from the U.S. National Institute of Allergy and Infectious Diseases and by a European Developing Countries Clinical Trial Partnership Senior Fellowship Award. Media contact for Johns Hopkins Bloomberg School of Public Health: Natalie Wood-Wright at 410-614-6029 or [email protected].

Jun 11, 2010

Health

Uninsured more likely to die from trauma than patients with insurance, study finds

BUFFALO, N.Y. -- Trauma patients without insurance are more likely to die of their injuries from auto accidents and gunshot wounds than privately insured patients with similar injuries, according to findings of an analysis of 193,804 patients from 649 facilities conducted by University Buffalo emergency medicine physicians. In addition, the authors found that Medicaid patients who were injured in motor vehicle accidents had a lower death rate than those with private insurance, indicating that factors other than the level of financial remuneration for medical services are influencing trauma outcomes. Patients covered by any of the insurance plans studied -- Medicaid, Medicare, private and managed care organizations such as HMOs -- had better mortality rates for all injuries than persons without insurance, the analysis showed. Results of the study were presented June 4 at the 2010 Society for Academic Emergency Medicine Annual Meeting in Phoenix, Ariz. Dietrich Jehle, MD, UB professor of emergency medicine and first author on the study, says these findings suggest that the causes of this difference are many and probably are not based just on quality of care. "Generally we don't know a trauma patient's insurance status when we treat them initially in the emergency department, which makes us ask if there are differences in these populations other than the delivery of care," says Jehle. "This finding was a little surprising. "Both race and insurance status are independent predictors of mortality rates for trauma outcomes, and of the two, insurance status, specifically lack of coverage, is the most significant," he continues. "This is not unexpected, since uninsured adult patients in general have a 25 percent greater morality rate than insured adults for all medical conditions." Lack of insurance could influence mortality in a number of ways, notes Jehle. With no way to pay for care, persons may delay getting treatment. Those without insurance frequently are from ethnic groups who face language or literacy problems, and may be afraid to go to a hospital. Other factors could include differences in risk-taking behaviors. Studies have shown a relationship between not wearing seat belts and lack of health insurance, and that the uninsured are likely to drive older, less safe vehicles. In addition, says Jehle, people without insurance have poorer health status in general, which would lessen their ability to survive a traumatic injury, and they often are treated differently. "Research shows that, for other than trauma injuries, the uninsured may actually receive less aggressive treatment and fewer diagnostic procedures," he says. Universal health coverage could change these statistics, Jehle says. "For instance, there would be no need for patients to delay treatment with universal health coverage, and such coverage could improve the overall health status of injury victims and increase their survival rates." The study data was extracted from the National Trauma Data Bank for 2001-05. The researchers concentrated on patients between the ages of 18 and 30 to eliminate those more likely to have chronic health conditions, leaving 191,666 patients in the analysis with complete data, including 150,332 blunt trauma patients and 41,334 penetrating trauma patients. Blunt trauma patients were most commonly in motor vehicle accidents, with smaller subgroups of patients with falls or assaults. The penetrating trauma patients included all gunshot wounds, plus small subgroups of injuries from stabbings. "If health care reform progresses," says Dietrich, "it would be interesting to revisit these findings." Kris Attwood, a UB biostatistics graduate student, and Seth Gemme, a UB medical student, also contributed to the study. The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.

Jun 11, 2010

Brain & Behavior

University of Pennsylvania: Contrary to popular models, sugar is not burned by self-control tasks

PHILADELPHIA -- - Contradicting a popular model of self-control, a University of Pennsylvania psychologist says the data from a 2007 study argues against the idea that glucose is the resource used to manage self control and that humans rely on this energy source for will power. The analysis, conducted by Robert Kurzban and published in the current issue of the journal Evolutionary Psychology, shows that evidence previously presented in favor of the claim that the brain consumes extra glucose when people exert self-control shows no such thing. The new analysis contradicts results published in the Journal of Personality and Social Psychology based on "resource" models of self control, suggesting that when people exert self control -- by, for example, carefully focusing their attention -- a resource is "depleted," leaving less of it for subsequent acts of self control. This study identified glucose as this resource that gets depleted. "For this model to be correct, it obviously must be the case that performing a self-control task reduces glucose levels relative to pre-task levels," Kurzban said. "Evidence from neurophysiology research suggests that this is unlikely, and the evidence for it is mixed at best." By analyzing the portion of the data made available by prior researchers, Kurzban discovered that, in the studies reported, glucose levels did not decrease among subjects who had performed self-control tasks. In short, his reanalysis shows that the researchers' own data undermine the model they advance in their paper. Kurzban's new analysis is consistent with the neuroscience literature, which strongly implies that the marginal difference in glucose consumption by the brain from five minutes of performing a "self-control" task is unlikely in the extreme to be of any significant size. Further, research on exercise shows that burning calories through physical activity, which really does consume substantial amounts of glucose, in fact shows the reverse pattern from what the model would predict: People who have recently exercised and burned glucose are better, not worse, on the sorts of tasks used in the self-control literature. "The failure to find the effect predicted by the glucose model of self control is not surprising given what is known about brain metabolism," Kurzban said. "Even very different computational tasks result in very similar glucose consumption by the brain, which tends to metabolize glucose at similar rates independent of task." Furthermore, even if exerting self control did reduce levels of glucose, the cause of the reduction could be factors such as increased heart rate when people perform certain kinds of tasks, rather than consumption by the brain. Glucose levels are probably influenced, Kurzban said, by a cascade of physical and psychological mechanisms that mediate glucose levels throughout the body. "The weight of evidence implies that the glucose model of self control in particular -- - and perhaps the resource model in general -- - ought to be carefully rethought," he said. "From a computational perspective, a 'resource' account is the wrong kind of explanation for performance decrements to begin with. No one whose computer is performing slowly would think that the fault lies in not having sufficient electricity -- - or that running Excel for five minutes will drain the battery and so make Word slow down -- - even though no one would deny that electricity is necessary for computers." One way to put the prior data in context, according to Kurzban, is to consider the data in terms of the familiar unit of calories. The brain as a whole consumes about one quarter of one calorie per minute. Obviously, the consumption rate for just the fraction of the brain involved in "self control" must, logically, be much smaller than .25 calories per minute. A 1 percent increase across the entire brain would, over the course of a five-minute task, consume .0125 calories. If one assumes an order of magnitude greater effect, a 10-percent increase, the amount of energy consumed would still be much less than a single calorie. "Even with these extreme assumptions, potentially off by orders of magnitude, the caloric cost would still be well less than .2 calories," Kurzban said. "The brains of subjects categorized as 'depleted' in this literature, have, relative to controls, used an additional amount of glucose equal to about 10 percent of a single Tic Tac."

Jun 11, 2010

Health

Virus infection may trigger unusual immune cells to attack nerves in multiple sclerosis

A virus infection can incite the body to attack its own nerve tissue by activating unusual, disease-fighting cells with receptors for both viral and nerve proteins. The dual-receptor observation suggests a way brain and spinal cord nerve damage might be triggered in susceptible young adults afflicted with multiple sclerosis (MS). University of Washington Department of Immunology scientists Qingyong "John" Ji, Antoine Perchellet, and Joan M. Goverman conducted the study, which was published June 6 in Nature Immunology. This is thought to be the first study to reveal a mechanism for autoimmune disease that depends on destroyer immune cells expressing dual receptors for a normal protein made by the body and a pathogen. Multiple sclerosis is one of many autoimmune disorders in which the body's lines of defense become misguided and start damaging normal tissue. In the case of multiple sclerosis, the protective sheath around major nerves -- the myelin -- in the brain and spinal cord disintegrates. Like a frayed electrical cord, the nerves no longer transmit a clear signal. People with multiple sclerosis might lose their ability to see, walk, or use their arms, depending on which nerves are affected. The symptoms can appear, disappear, and re-appear. The disease is more common in women than in men. In healthy people, the immune system is kept in check to tolerate the usual proteins and cells in the body, much like an eager watch dog is put on a leash and trained to ignore friends and neighbors, yet still protect the family. "Autoimmunity is believed to arise from an accidental breakdown in this tolerance of the body's own proteins. This breakdown is triggered by something in the environment, most likely a pathogen," noted Goverman, professor and acting chair of immunology whose research concentrates on the origins of autoimmune disease. Her lab is studying mechanisms that maintain tolerance, as well as the "tripping" mechanisms that defeat it. In their most recently published study, her research team genetically engineered mice that over-produce a certain type of white blood cell from a group known as killer T cells. The normal function of killer cells is to attack tumor cells or cells infected with viruses or other pathogens. These T cells have receptors that recognize specific proteins that infected cells display to them, much like holding up a target in a window. The specific killer T cells examined in this study were CD8+ T cells. The Goverman lab engineered mice to over-produce CD8+cells that recognized myelin basic protein, a predominant protein in the myelin sheath that covers nerves. The major question investigated in the study was whether the genetically engineered mice would exhibit a disease that resembled multiple sclerosis. The researchers infected the mice with a virus that has itself been engineered to produce myelin basic protein. This infection should activate the CD8+T cells to first attack the virally infected cells making myelin basic protein to eliminate the virus, then kill other cells that make myelin basic protein to wrap around nerves. Killing those cells would destroy the myelin sheath. As expected, the mice developed a multiple sclerosis-like disease. But the researchers were surprised when viruses lacking the myelin basic protein also triggered the disease. Additional cross-breeding experiments revealed the existence of two receptors on a few of the CD8+T cells. These cells, engineered specifically to bind to myelin basic protein, also built their own receptors for viruses, and could recognize both. When exposed to cells infected with viruses, they would bind to and destroy them using one receptor. Geared up as if they were beserk, some of these double-agent cells then would head elsewhere to bind their other receptor to cells producing myelin basic protein and ruin the coats on nerve cells. "These results," the authors noted, "demonstrate a role for dual-receptor cells in autoimmunity." The study also points to why a ubiquitous viral infection could leave most people without any lasting effects, but trigger autoimmunity in genetically predisposed individuals. The findings open a new perspective on the proposal that multiple sclerosis is virally induced, despite the inability to detect infectious virus in the central nervous system of multiple sclerosis patients. Data from other studies show that CD8+T cells can cross the blood-brain barrier, and also that multiple sclerosis patients have more central nervous system protein-specific CD8+T cells, compared to healthy people. In the dual-receptor model, the autoimmune activity against nerve protein can continue after the virus is wiped out. Multiple sclerosis patients usually have high levels of antibodies indicating past infectious from several common viruses, but a live virus associated with multiple sclerosis has not been consistently observed. Therefore, to date, no specific virus has been confirmed as a causative agent for multiple sclerosis. The authors explained that it's possible that multiple viruses could influence susceptibility to multiple sclerosis. The ability of any particular virus to contribute to the disease could depend on an individual's own repertoire of other predisposing genes, exposure to other predisposing environmental factors, and the random chance that T cells had been generated that recognize a myelin protein and a pathogen. Receptors on T cells are randomly generated during their development. This observation helps explain why multiple sclerosis is partly a matter of chance. Some people with a genetic predisposition and environmental exposure develop the disease, while others with similar genetic predisposition and environmental exposure do not. It's uncertain how common these dual-receptor T cells are, according to the researchers, although there are reports that up to one-third of human T cells express dual receptors. Goverman and her group plan to test samples from multiple sclerosis patients and see how many have dual-receptor T-cells. A grant from the National Institutes of Health supported the study.

Jun 11, 2010

Earth & Environment

A high-resolution Asian monsoon record from 16.2 to 7.3 thousand years before present

Research at the School of Geographical Sciences, Southwest University (SWU) in Chongqing, China-Research, has demonstrated that the record of the Asian Summer Monsoon (ASM) covers the last deglaciation and the early Holocene (from 16.2 to 7.3 ka BP), with an average oxygen isotope resolution of 9 years (issue 53, May 2010 of SCIENCE CHINA Earth Sciences). Understanding the factors responsible for past climatic changes is a key to understand future climate change. Such climatic changes include abrupt events that take place over time scales of centuries to decades. Evidence of these rapid changes is present in the geologic record as distinctive signatures in marine sediments, ice cores, loess, lake sediments, tree rings, and cave sediments. For example, recent studies have used cave stalagmite records to study monsoon history. Nevertheless, well-dated, continuous, and high-resolution records are not common. In this work, a high-resolution (9-year intervals, on average) record of the ASM was established covering the time range from 16.2 to 7.3 ka BP. Generally speaking, a high-resolution record is important to identify the mechanisms responsible for changes in the monsoonal climate. Dr. Yang reported a record based on 33 U/Th dates and 1020 oxygen isotopes from stalagmite Y1 from Yamen Cave (107°54′E, 25°29′N), Guizhou Province, China. This region is currently influenced by both the East Asian and the Southwest Indian monsoons. The main millennial-scale deglacial events first identified in Greenland (Greenland Interstadial Events: GIS 1e through GIS 1a), and later in China, are clearly present in the stalagmite Y1 record. Analogous to earlier work, these are referred to as Chinese Interstadials (CIS): CIS A.1e to CIS A.1a. The onset of these events in Y1 δ18O records are nominally dated at: 14750±50, 14100±60, 13870±80, 13370±80, and 12990±80 a BP. The end of the CIS A.1a or the beginning of the Younger Dryas (YD) event is nominally at 12850±50 a BP, and the end of the YD dates are 11500±40 a BP. The δ18O values shift to about 3‰ during the transition into the Bølling-Allerød (BA, the onset of CIS A.1e) and at the end of the YD. Comparisons of Y1 to previously published early Holocene records show no significant phase differences. Thus, the East Asian and the Indian monsoons do not appear to have been out of phase during this interval. The Y1 record confirms earlier work suggesting that solar insolation and North Atlantic climate both affect the Asian Monsoon. "This paper not only enriches the high-resolution record of this period for paleo-climatic reconstruction, but based on this time-scale for discussion of the characteristics of climate changes, it also has important scientific significance" said one journal reviewer. "Stalagmite Y1 record has higher time resolution than others in the study region, which can be more subtle to the discussion of scientific issues, such as the phase differences of the Asian Monsoon in the past" said another reviewer. The authors are affiliated with the Laboratory of Geochemistry and Isotope (LGCI) of SWU. This laboratory is conducting research mainly in three areas: 1) Karst records for paleo-environments, 2) Uranium series dating, and 3) environmental isotopes. Funding from the National Natural Science Foundation of China (Grant Nos. 40902053 and 40772216) and the US National Science Foundation (Grant No. 052535) supported this research. Reference: Yang Y, Yuan D X, Cheng H, Zhang M L, Qin J M, Lin Y S, Zhu X Y and Edwards R L. Precise dating of abrupt shifts in the Asian Monsoon during the last deglaciation based on stalagmite data from Yamen Cave, Guizhou Province, China. Sci China Earth Sci, 2010, 53(5): 633-641 http://springerlink.com/content/24824004962442r1/?p=8e9cbbca2b4f409baf1e60b54339c0af&pi=0=doi: 10.1007/s11430-010-0025-z

Jun 11, 2010

Earth & Environment

New model is proposed to explain absence of organic compounds on surface of Mars

New Rochelle, June 10, 2010 -- The ongoing search for evidence of past or present life on Mars includes efforts to identify organic compounds such as proteins in Martian soil, but their absence to date remains a mystery. A new theory to explain what happens to these carbon-based molecules is presented in an article published in Astrobiology, a peer-reviewed journal published by Mary Ann Liebert, Inc. The article is available free online at www.liebertpub.com/ast. "There may be no 'safe haven' for these organic molecules on Mars," conclude Ilya Shkrob, Sergey Chemerisov, and Timothy Marin, from Argonne National Laboratory and Benedictine University, in Illinois, in their article entitled "Photocatalytic Decomposition of Carboxylated Molecules on Light-Exposed Martian Regolith and its Relation to Methane Production on Mars." Unlike on Earth, where plants and other organisms convert carbon dioxide and water into organic compounds via photosynthesis, the authors propose that the opposite happens on the surface of Mars. The iron oxides that make up Martian soil and give the planet its distinctive red color are photocatalysts. They use energy from ultraviolet light absorbed through the thin Martian atmosphere to oxidize carbon-containing organic molecules trapped in soil particles, converting them to carbon dioxide and gases such as methane. The authors present study data to support this model and to explain why it might not be realistic to rely on the discovery of proteins, amino acids, and other carbon-containing compounds in the upper soil layers of Mars to determine whether life forms are or have been present on the planet. "This is an interesting result and may be an important step in solving the enduring mystery of organics on Mars," says Christopher P. McKay, Senior Editor of Astrobiology and Research Scientist at NASA Ames Research Center. "We see organics in many places in the solar system but have not been able to detect them on Mars -- the planet that we think had the most Earth-like conditions. Why? Could it be our instrument approach has been wrong? Or could it be that there is some chemistry on Mars that is actively destroying organics? This work points toward this latter explanation. Mars may have a self cleaning surface. If so, we may have to dig deeply to find any organic materials." "The importance of drilling below the Martian surface for rocks and soils that might retain preserved organics is certainly on the minds of future mission scientists," says Sherry L. Cady, PhD, Editor of Astrobiology and Associate Professor in the Department of Geology at Portland State University. "The possible 2018 joint ESA-NASA mission is a case in point." Astrobiology is an authoritative peer-reviewed journal published 10 times a year in print and online. The Journal provides a forum for scientists seeking to advance our understanding of life's origins, evolution, distribution, and destiny in the universe. The complete tables of content and the full text for this issue may be viewed online at www.liebertpub.com/ast Mary Ann Liebert, Inc. (www.liebertpub.com) is a privately held, fully integrated media company known for establishing authoritative peer-reviewed journals in many promising areas of science and biomedical research. Its biotechnology trade magazine, Genetic Engineering & Biotechnology News (GEN), was the first in its field and is today the industry's most widely read publication worldwide. A complete list of the firm's 60 journals, books, and newsmagazines is available at www.liebertpub.com

Jun 10, 2010

Health

Many comets originally formed in other solar systems: Queen's University astronomer

Many of the most well known comets in history, including Halley, Hale-Bopp and McNaught, may have been born in orbit around other stars and not the Sun, according to a new study by Queen's University astronomy professor Martin Duncan and an international team of astronomers. "Anyone who has seen a long tail comet in the night sky may be looking at material from another star," says Professor Duncan. The researchers used computer simulations to show that the Sun may have captured small icy bodies from its sibling stars while it was in its birth star cluster, and this created a reservoir for observed comets. Although the Sun currently has no companion stars, it is believed to have formed in a cluster containing hundreds of closely packed stars that were embedded in a dense cloud of gas. During this time, each star formed a large number of small icy bodies (comets) in a disk from which planets formed. Most of these comets were gravitationally slung out of these prenatal planetary systems by the newly forming giant planets, becoming tiny, free-floating members of the cluster. The Sun's cluster came to an end when its gas was blown out by the hottest young stars. The researchers' computer models show that the Sun then gravitationally captured a large cloud of comets as the cluster dispersed. "The process of capture is surprisingly efficient and leads to the exciting possibility that the cloud contains a potpourri which samples material from a large number of stellar siblings of the Sun," says Professor Duncan. Evidence for the team's scenario comes from the roughly spherical cloud of comets (called the Oort cloud) which surrounds the Sun. Exactly how the Oort cloud was created has been a mystery for more than 60 years. "We have a new model of how the Oort cloud formed. We're not the first to suggest this could happen but we are the first to show it in a detailed computer simulation," adds Professor Duncan. The research team also included Hal Levison and David Kaufmann (both of Southwest Research Institute in Boulder, CO) and Ramon Brasser (Observatoire de la Cote d'Azur, France). Their findings, "Capture of the Sun's Oort Cloud from Stars in its Birth Cluster" was published today in the online journal Science Express.

Jun 10, 2010

Health

Experts identify biological control to contain fungus killer in Kenya's maize supply

Dar es Salaam, 10 June 2010 - As Kenya once again grapples with high levels of aflatoxin contamination, which has rendered at least 2.3 million bags of maize unfit for human and livestock consumption, international experts announced today that they have identified a local non-toxic form of the fungus responsible for aflatoxin that can be used to control contamination through a novel biological control approach, which is entirely safe and effective. The experts are seeking to form a public-private partnership in Kenya through which the new approach could be widely applied, reducing a major health hazard for the public and preventing huge economic losses for farmers and the government. The contamination of the country's main staple with aflatoxin, a highly poisonous cancer-causing chemical produced by a fungus scientifically known as Aspergillus flavus, was a result of poor drying and storage of the grain following heavy rainfall near harvest time. "A. flavus strains are either toxigenic (produce aflatoxin) or atoxigenic (do not produce aflatoxin). Our biocontrol technology makes use of carefully selected atoxigenic strains or the 'good guys' that can safely outcompete and virtually eliminate their toxic relative or 'the bad guys', effectively reducing contamination of the maize grains in fields," said Dr Ranajit Bandyopadhyay, a plant pathologist with the Africa-based International Institute of Tropical Agriculture (IITA), Dr Peter Cotty of the Agriculture Research Service of the United States Department of Agriculture (USDA-ARS) and Dr Bandyopadhyay have identified biocompetitive strains of the good fungus native to Kenya that can now be used to control aflatoxin contamination in the country. According to Dr Bandyopadhyay, a single application of this biopesticide 2-3 weeks before maize flowering is sufficient to prevent aflatoxin contamination throughout and beyond a cropping season and even when the grains are in storage. He says that the technology's ability to continue working even when the grain is in storage ensures the safety of maize from aflatoxin contamination. "These atoxigenic strains are also carried in the grains from the field to the stores. So, even if the grains are not stored properly or get wet during or after harvest, as is happening this year, they continue to prevent aflatoxin contamination during the postharvest period," said Dr Bandyopadhyay. Aflatoxin is a silent killer that causes liver cancer and suppresses the immune system. It also retards growth and development of children. People exposed to very high aflatoxin concentrations experience liver failure and rapid death. From 2004 to 2006, nearly 200 unsuspecting people in Kenya died in this manner after eating highly contaminated maize. Aflatoxin is a colorless chemical that is invisible and only laboratory tests can confirm its presence and contamination levels. Kenya is one of the world's hotspots for aflatoxin. Research performed by one of Dr Cotty's graduate students, Claudia Probst, has shown that in areas where aflatoxin is a persistent and serious problem, there is a very high occurrence of one of the most toxic strains of A. flavus in the world, the S strain. According to Dr Cotty, the S strain produces very high levels of aflatoxins and dominates in regions where contamination is very high, including some areas of the US. In Africa, this S strain has been only found to be dominant in the severely affected regions of Kenya. In the US, biocontrol with atoxigenics has successfully reduced its contamination. In Nigeria, IITA has obtained provisional registration of the technology under the name Alfasafe™, a mixture of four atoxigenic strains of Nigerian origin. In 2009, maize farmers in Nigeria were able to reduce aflatoxin contamination by 80% by broadcasting 10 kg/ha Aflasafe™ 2-3 weeks before maize flowering. Research has shown that Aflasafe™ treatments provide long-term benefits and that Aflasafe™ may not need to be applied every year. IITA, in partnership with the Nigerian government and the United Nations Industrial Development Organization (UNIDO), is working on obtaining full registration and identifying an entity that would mass manufacture, market, and distribute Aflasafe™ in Nigeria to save the health and income of millions of families. The researchers are now calling upon the government and the private sector in Kenya to partner with them and make this biocontrol option and other management practices available to the farmers to save their much-needed harvests from future aflatoxin contamination. Institutions involved in the initiative include IITA, USDA-ARS, African Agricultural Technology Foundation (AATF), and local partners. For more details, please contact: Ranajit Bandyopadhyay, [email protected] IITA Plant Pathologist Peter Cotty, [email protected] Agriculture Research Service, United States Department of Agriculture ( USDA-ARS), School of Plant Sciences, University of Arizona Jacob D.H. Mignouna, [email protected] Director, Technical Operations African Agricultural Technology Foundation (AATF) Catherine Njuguna, [email protected] Corporate Communications Officer (East & Southern Africa) IITA-Tanzania Jeffrey T. Oliver, [email protected] Corporate Communications Manager Communication Office IITA Headquarters Ibadan, Nigeria About IITA (www.iita.org) Africa has complex problems that plague agriculture and people's lives. We develop agricultural solutions with our partners to tackle hunger and poverty. Our award-winning research for development (R4D) is based on focused, authoritative thinking anchored on the development needs of sub-Saharan Africa. We work with partners in Africa and beyond to reduce producer and consumer risks, enhance crop quality and productivity, and generate wealth from agriculture. IITA is an international nonprofit R4D organization established in 1967, governed by a Board of Trustees, and supported primarily by the CGIAR. About ARS-USDA (http://www.ars.usda.gov/main/main.htm) ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture (USDA). This research supports the USDA priority of promoting international food security. About AATF (www.aatf-africa.org) AATF is an African-led charity designed to facilitate and promote public/private partnerships for the access and delivery of appropriate proprietary technologies with potential to increase the productivity of resource-poor smallholder farmers in Sub-Saharan Africa.

Jun 10, 2010

Health

Study shows Hodgkin lymphoma survivors lack post-treatment screening for other cancers

A population-based study of 2,071 Hodgkin lymphoma (HL) survivors over 15 years has discovered that while many survivors had multiple X-rays and CT scans years after treatment was finished, they often did not receive recommended cancer screening tests. The study, available online ahead of print publication in the July issue of the American Cancer Society journal Cancer (www.interscience.wiley.com DOI 10.1002/cncr.25053), followed the survivors for up to 15 years after their HL diagnosis by evaluating physician visits, imaging studies, and the use of routine and HL-specific cancer screening tests. Survivors had CT scans at a rate three times greater than in the general population, even 10 to 15 years after their original diagnosis. "It is not clear why the CT scans were ordered, but they certainly did not appear to be an efficient way to detect relapse, particularly this long after treatment was finished," says principal investigator David Hodgson, a radiation oncologist at the Princess Margaret Hospital Cancer Program, University Health Network, and investigator at the Institute of Clinical Evaluative Sciences. Most HL patients never experience a relapse. For those who do, they usually know something is wrong before their doctor does. It is uncommon to detect relapse with CT alone in a patient who is feeling well. "For these patients, the telephone, not the CT scanner, is the most important technology," says Dr. Hodgson. "Oncologists need to advise their patients what symptoms should prompt them to seek medical attention -- and physicians have to be able to evaluate them in a timely way to decide if imaging is needed." Despite frequent contact with both specialists and primary care providers, many survivors did not receive recommended cancer screening tests. Among those who met criteria for routine screening, 62.5% were not screened for colorectal cancer, 32.3% were not screened for breast cancer and 19.9% were not screened for cervical cancer (Pap test). "Our results indicate that the optimal follow-up care did not happen, even though most patients had visits with both a primary care provider and an oncologist in years two through five. So there are opportunities to improve post-treatment surveillance for relapse and late effects." Of particular concern is the finding that 87.1% of young women potentially at high risk of breast cancer because of prior radiation therapy were not screened. In the past decade, clinical practice guidelines have recommended that some patients start breast cancer screening before the usual starting age. Says Dr. Hodgson: "Most HL patients are cured, but they can be at risk many years later of developing secondary cancers or other late effects of their initial treatment. This is why quality of follow-up care post-treatment is so important. And, increasingly, it is also important for other survivors as cure rates for several forms of cancer improve." The research was supported by Cancer Care Ontario, who awarded Dr. Hodgson a 2008 Research Chair in Patterns of Care. Princess Margaret Hospital and its research arm Ontario Cancer Institute, which includes the Campbell Family Cancer Research Institute, have achieved an international reputation as global leaders in the fight against cancer. Princess Margaret Hospital is a member of the University Health Network, which also includes Toronto General Hospital and Toronto Western Hospital. All three are research hospitals affiliated with the University of Toronto. For more information, go to www.uhn.ca

Jun 10, 2010