October 17, 2006, 4:53 AM CT
Listening To The Sound Of Skin Cancer
Scientists at the University of Missouri-Columbia can now detect the spread of skin cancer cells through the blood by literally listening to their sound. The unprecedented, minimally invasive technique causes melanoma cells to emit noise, and could let oncologists spot early signs of metastases -- as few as 10 cancer cells in a blood sample -- before they even settle in other organs. The results of the successful experimental tests appear in the Oct. 15 issue of the journal Optics Letters, published by the Optical Society of America.
The team's method, called photoacoustic detection, combines laser techniques from optics and ultrasound techniques from acoustics, using a laser to make cells vibrate and then picking up the characteristic sound of melanoma cells. In a clinical test, doctors would take a patient's blood sample and separate the red blood cells and the plasma. In a healthy person, the remaining cells would be white blood cells, but in a melanoma patient the sample may contain cancer cells. To find out, doctors would put the sample in saline solution and expose it to rapid-fire sequences of brief but intense blue-laser pulses, each lasting just five billionths of a second.
In lab tests, the Missouri-Columbia team was able to detect melanoma cells obtained from actual patients, showing that the method can spot as few as 10 cells in saline solution. The dark, microscopic granules of melanin contained in the cancer cells absorb the energy bursts from the blue-laser light, going through rapid cycles of expanding as they heat up and shrinking as they cool down. These sudden changes generate loud cracks -- relative to the granules' size -- which propagate in the solution like tiny tsunamis.........
Posted by: George Permalink Source
October 17, 2006, 4:48 AM CT
Studying Tumor Genomics
The newly established Berkeley Cancer Genome Center, led by members of the Life Sciences Division in the Department of Energy's Lawrence Berkeley National Laboratory, is one of seven Cancer Genome Characterization Centers to receive awards from the National Cancer Institute and the National Human Genome Research Institute. Earlier today the two institutes, both part of the National Institutes of Health, announced a three-year, $35 million project which will seek to identify important genetic changes involved in lung, brain, and ovary cancers through genome analysis.
The Berkeley Cancer Genome Center is a collaboration between Berkeley Lab, the University of California at Berkeley, and the University of California at San Francisco. The center's director is Joe W. Gray, who is the director of the Life Sciences Division and Berkeley Lab's Associate Laboratory Director for Life and Environmental Sciences. Computational biologist Paul Spellman of the Life Sciences Division is codirector.
"The Berkeley Cancer Genome Center will be focused on identifying changes to the populations of messenger RNA that occur in cancer," says Spellman. Such changes are indicative of different kinds of proteins produced by the altered genomes of tumor cells.
Spellman says, "The Center will use the Affymetric Exon 1.0 array platform to measure exon-specific expression" - exons are the coding sequences in a gene - "of at least 1,000 samples per year, and will use computational tools to identify those whose behavior suggests they might play a role in cancer."........
Posted by: Janet Permalink Source
October 17, 2006, 4:43 AM CT
New Hope For Children With Leukemia
Clinicians at St. Jude Children's Research Hospital have successfully demonstrated an improved technique for blood stem cell transplantations in children that shows promise for those most likely to fail standard therapy for leukemia.
The St. Jude technique allows blood stem cells to come from parents or unmatched adult siblings; and it avoids the aggressive, toxic therapys that commonly must accompany the transplant. This allows the majority of patients with leukemia or non-malignant blood disorders to receive a transplant, as per Gregory Hale, M.D., St. Jude Bone Marrow Transplantation Division interim chief. A report on this work appears in the prepublication edition of the British Journal of Haematology.
A clinical trial of this technique demonstrated that it accelerated recovery of the immune system in recipients and shortened the duration of immune deficiency during the early post-transplant period, reducing the risk of infections. The immune system recovery included not only T and B lymphocytes, the major cells genetically programmed to attack specific targets, but also natural killer cells, a critical first-response army of cells that acts as a quick-strike force against a wide variety of targets.
"The overall success of this procedure suggests it holds promise for children who are likely to fail standard therapy for leukemia because they have therapy-resistant disease and no matched donor," Hale said.........
Posted by: Janet Permalink Source
October 17, 2006, 4:29 AM CT
Broccoli's Cancer Fighting Secrets
After all these years, mom was right. She knew broccoli was good for you, she just didn't know it was this good.
"Everyone knows broccoli is good for you and that it contains compounds known to lessen the occurrence of some types of cancer. We want to know how these compounds work and what their specific targets may be," says Janet V. Cross, Ph.D., Assistant Professor of Pathology at the University of Virginia School of Medicine.
Cross and her colleague Dennis J. Templeton, M.D., Ph.D., chairman of the UVa Department of Pathology have received a $1.3 million grant from the National Cancer Institute (NCI) to study how specific nutrients in healthy vegetables like broccoli work to prevent cancer.
Cross and Templeton observed that nutrients in broccoli unexpectedly bond with a specific enzyme in cells. This enzyme had been clearly associated with inflammatory disease processes, but Cross solidified a link with cancer when she observed that mice who did not have the gene for this enzyme developed far fewer cancers when given carcinogens.
"If we can determine that this specific enzyme is the reason the compounds in broccoli work to prevent cancer, then these nutrients or similar chemicals could be turned into anti-cancer compounds," she says.........
Posted by: Janet Permalink Source
October 16, 2006, 10:20 PM CT
Chemistry To Predict The Dynamics Of Clotting
This image shows clotting occurring on a large area of vascular damage, but not small areas.
Credit: Nicolle Rager Fuller, National Science Foundation
University of Chicago chemists have shown for the first time how to use a simple laboratory model consisting of only a few chemical reactions to predict when and where blood clotting will occur. The researchers used microfluidics, a technique that allowed them to probe blood clotting on surfaces that mimic vascular damage on the micron scale, a unit of measurement much narrower than the diameter of a human hair.
Eventhough researchers understand what occurs during a number of of the 80 individual chemical reactions involved in blood clotting, a number of questions about the dynamics of the entire reaction network remain. Rustem Ismagilov, Associate Professor in Chemistry at the University of Chicago, and graduate students Christian Kastrup, Matthew Runyon and Feng Shen have now developed a technique that will enable researchers to understand the rules governing complex biological reaction networks. They will detail their technique in the online early edition of the Oct. 16-20 issue of the Proceedings of the National Academy of Sciences.
Life and death literally depend on a finely tuned blood-clotting system. "Clotting has to occur at the right place at the right time," Ismagilov said. "A strong, rapid clotting response is essential to stop bleeding at a wound, but such a clotting response at the wrong spot can block blood vessels and can be life-threatening".........
Posted by: Scott Permalink Source
October 16, 2006, 10:09 PM CT
Prescription Pain Medication Abuse On Increase
Scientists at Rush University Medical Center found prescription pain medicine (PPM) abuse is a rapidly growing problem with surprising and often unpredictable distribution patterns. The research was presented at the Annual Meeting of the American Society for Anesthesiologists in Chicago, October 13, 2006.
Mario Moric, PhD, a researcher in the department of Anesthesiology at Rush, and his colleagues used survey data from the National Survey on Drug Use and Health for 2002-04 to estimate the prevalence of drug abuse across the United States for various illicit and prescription substances.
Moric observed that PPM abuse did not follow traditional patterns. "Individual states with high levels of PPM abuse may not recognize the problem. The prevailing assumption that only those states with high levels of traditional illicit drug abuse should be vigilant is clearly misleading".
The scientists found distribution of PPM abuse across the United States varied greatly and differed from other seemingly similar drug abuse trends. PPM distribution differed substantially from inhalants, heroin and sedatives, was somewhat similar to cocaine and stimulants and was closely correlation to distribution of tranquilizers.
Furthermore, the scientists observed that states with large metropolitan areas (New York, Illinois, Texas and California) did not have a high distribution of abuse, despite the common view that drug abuse is linked to the fast-paced lifestyle of city dwellers.........
Posted by: Janet Permalink Source
October 16, 2006, 10:05 PM CT
How Ebola And Marburg Cause Disease
Scientists in the Greene Infectious Disease Laboratory at Columbia University's Mailman School of Public Health, the Centers for Disease Control and Prevention, and the Caribbean Primate Research Center have discovered a key mechanism by which the Filoviruses, Ebola and Marburg, cause disease. The identification of an amino acid sequence in Filoviruses that results in the rapid depression of immunological response is described in the December 2006 issue of The FASEB Journal. Using this information, scientists can begin to develop new drugs to stop these devastating diseases.
Filoviruses, named for their threadlike appearance in electron microscopy (filo= thread in Latin), are linked to outbreaks of fatal hemorrhagic fever in sub-Saharan Africa. Viral hemorrhagic fevers are of specific concern because they are linked to high morbidity and mortality (up to 80% mortality rates) and the potential for rapid dissemination through human-to-human transmission. The term "viral hemorrhagic fever" characterizes a severe multisystem syndrome linked to fever, shock, and bleeding caused by infection with one of many viruses, including the Filoviruses Ebola and Marburg.
Both humans and apes are susceptible to viral hemorrhagic fevers, and it is speculated that filovirus infections account at least in part for the recent decline in the gorilla and chimpanzee population in central Africa. There is no cure or approved vaccine for either Marburg or Ebola virus. Immunosuppression occurs early after infection and allows the viruses to reproduce rapidly and cause disease.........
Posted by: Mark Permalink Source
October 16, 2006, 9:56 PM CT
Asthma Linked To Soot From Diesel Trucks
Soot particles spewing from the exhaust of diesel trucks constitute a major contributor to the alarmingly high rates of asthma symptoms among school-aged children in the South Bronx, as per the results of a five-year study by scientists at New York University's School of Medicine and Robert F. Wagner Graduate School of Public Service.
Over the course of the study, asthma symptoms, especially wheezing, doubled among elementary school children on high traffic days, as large numbers attend schools in close proximity to busy truck routes because of past land-use decisions.
The South Bronx has among the highest incidences of asthma hospital admissions in New York City, and a recent city survey of asthma in the South Bronx's Hunts Point district found an asthma prevalence rate in elementary school of 21 percent to 23 percent. The South Bronx is surrounded by several major highways, including Interstates 95, 87, 278 and 895. At Hunts Point Market alone, some 12,000 trucks roll in and out daily.
The study is a collaboration of NYU School of Medicine, the Robert F. Wagner Graduate School of Public Service, and four community groups The Point Community Development Corporation, Sports Foundation, Inc., We Stay/Nos Quedamos, Inc., and Youth Ministries for Peace & Justice Inc. Endorsed by Congressman Jose E. Serrano, the aim of the study was to examine the impact of industrial emissions on air quality and to direct policy initiatives. Serrano sponsored the press conference today where the findings were discussed.........
Posted by: JoAnn Permalink Source
October 16, 2006, 9:52 PM CT
Women On Hormone Therapy
Older women on hormone treatment are more sensitive to negative events, confirming speculation that age-related estrogen loss affects the brain's ability to process emotion, an Oregon Health & Science University study shows.
But that sensitivity to negative emotional events, such as viewing a photograph of a dead person, doesn't necessarily mean women taking estrogen remember those events any better.
In the study by scientists in the Cognition & Aging Laboratory at the OHSU School of Medicine's Department of Behavioral Neuroscience, hormone treatment in women appears to reverse the age-related loss of arousal to negative emotional events experienced by the elderly. It also points to specific changes in the brain's arousal system, in the regions that process emotion, and intensification of negative emotions.
The results were presented today at Neuroscience 2006, the Society for Neuroscience's 36th annual meeting at the Georgia World Congress Center in Atlanta.
Researchers have suspected a link between sex hormones and emotion. Strengthening this theory is the fact that brain regions tuned for processing emotion and storing emotional memory - the amygdala and hippocampus - also respond to sex hormones and contain hormone receptors. Thus, changes in "emotional enhancement" people experience as they age, including a reduction in the ability to remember negative events, may be modified by age-related loss of sex hormones or hormone treatment.........
Posted by: Emily Permalink Source
October 16, 2006, 8:55 PM CT
Could Dreams Be A Mechanism To Help Us Prepare For Danger?
Dreams have been interpreted in a number of different ways through the ages: as messages from the gods, repressed sexual fantasies..... or, based on an evolutionist approach that emerged around the turn of the millennium, as a mechanism that helps us to prepare survival strategies in the face of danger.
Antonio Zadra, a professor in the Department of Psychology, likes that last theory. "Among its merits is that it lets us formulate hypotheses that can be tested quite easily," says Zadra, whose initial study tested no fewer than eight hypotheses derived from the new approach.
The theory was developed by Antti Revonsuo, Director of the Consciousness Research Group at the Centre for Cognitive Neuroscience at the University of Turku in Finland. He postulates that dreams developed in our long-ago ancestors to simulate outside threats, enabling the dreamer to put into practice or rehearse avoidance behaviours.
Pleistocene man faced constant threats from predators, rival tribes, and forces of nature. Seeking ways to avoid danger, our ancestors lived in a perpetual state of alert, and so the dream function assumed the form we see today. The theory is also based on the fact that rehearsing an action in your mind can improve the motor skills needed.
Research on dreams lends some credence to the theory. Research in the 1960s showed that 80% of dreams are negative in content, and misfortune occurs seven times more often than good fortune in dreams. In 96% of cases where there is some interaction with an animal, there is aggression. For both men and women, enemies are nearly always strangers - male strangers.........
Posted by: JoAnn Permalink Source