Links, articles, obesity, cancer and more, just dig in…
Scientists discover new genetic marker of ovarian cancer risk
Science codex
http://www.sciencecodex.com/yale_scientists_discover_new_genetic_marker_of_ovarian_cancer_risk
A team of Yale researchers have identified a genetic marker that can help predict the risk of developing ovarian cancer, a hard to detect and often deadly form of cancer.
Reporting online in the July 20 edition of the journal Cancer Research, the team showed that a variant of the KRAS oncogene was present in 25 percent of all ovarian cancer patients. In addition, this variant was found in 61 percent of ovarian cancer patients with a family history of breast and ovarian cancer, suggesting that this marker may be a new marker of ovarian cancer risk for these families, said the researchers.
‘For many women out there with a strong family history of ovarian cancer who previously have had no identified genetic cause for their family’s disease; this might be it for them,’ said Joanne B. Weidhaas, associate professor of therapeutic radiology, researcher for the Yale Cancer Center and co-senior author of the study. ‘Our findings support that the KRAS-variant is a new genetic marker of ovarian cancer risk.’
Weidhaas and co-senior author Frank Slack. also of Yale, first searched for the KRAS-variant among ovarian cancer patients and found that one in four had the gene variant, compared to 6 percent of the general population. To confirm that the KRAS-variant was a genetic marker of ovarian cancer risk, they studied women with ovarian cancer who also had evidence of a hereditary breast and ovarian cancer syndrome. All these women had strong family history of cancer, but only half in their study had known genetic markers of ovarian cancer risk, BRCA1 or BRCA2 mutations.
Six out of 10 women without other known genetic markers of ovarian cancer risk had the KRAS-variant. Unlike women with BRCA mutations who develop ovarian cancer at a younger age, women with the KRAS-variant tend to develop cancer after menopause. Because ovarian cancer is difficult to diagnose and thus usually found at advanced stages, finding new markers of increased ovarian cancer risk is critical, note the researchers.
Genetic tests for the KRAS-variant are currently being offered to ovarian cancer patients and to women with a family history of ovarian cancer by MiraDX, a New Haven-based biotechnology company that has licensed the Yale discoveries.
The study was funded by the National Institutes of Health. Weidhaas and Slack have a financial interest in MiraDX.
According to some: The 10 most influential psychiatrists in the world (Even though if some were not psychiatrists)
Top 10 Most Influential Psychiatrists
Psychology has, historically, been considered the ugly stepchild of science. There are some legitimate reasons for this. First of all, the average person associates psychology with the kooky antics on on-screen therapists in various movies and T.V. shows. Second, everyone considers him or herself an ‘amateur’ psychologist. While most of us don’t have direct experiences with black holes, DNA or atoms, we all have experienced and generated behavior, emotions and thoughts. Finally, few understand that, historically, there were attempts to shape psychology as a science of human nature, along the lines of physics or chemistry. Unfortunately, modern psychology is an incredibly fractured discipline with many components, some of more value than others. The ten individuals I’ve selected, in my semi-educated opinion, are those who had the greatest impact on the shaping of psychology into the field it is today (both for good and ill).
Karl Lashley
1890-1958
Karl Lashley is a debatable choice for the tenth spot. I selected him because he was one of the first psychologists to try to understand the physiological underpinnings of behavior. Lashley was an American psychologist who initially worked with John Watson. However, Watson was never very interested in the brain-behavior relationship and Lashley eventually went his own direction. He conducted a series of studies with rats where he attempted to locate the ‘engram’ or the physiological seat of memory. Lashley trained his rats to run a maze, systematically removed portions of their brains, and observed any effect it had on their ability to run the maze afterwards. Lashley found, to his astonishment, that it didn’t matter. What did matter is how much of the brain was removed. Lashley would go on to train, and mentor, a number of psychologists and physiologists who built upon his early work linking brain and behavior. Currently, much of the work in modern experimental psychology is focusing on this topic.
B.F. Skinner
1904-1990
B.F. Skinner is one of the few psychologists with name recognition outside the field. Much of this had to do with his charismatic personality, excellent writing ability (he originally wanted to be a novelist), and confrontational style. Skinner was convinced that his approach to psychology was the only reasonable one, and had little patience with opposing views. Arrogance aside, few men in history can claim to have created the vocabulary for an entire discipline. In psychology, when we speak of ‘operant conditioning’, ‘positive reinforcement’, and ‘shaping’ these are terms introduced and popularized by Skinner. But his ideas go beyond terminology. Skinner was instrumental in making his notion of psychology (called ‘behaviorism’) a dominant force in the discipline. In fact, in America, between the years 1930 and 1950, behaviorism WAS psychology. Much of this had to do with the compelling nature of Skinner’s ideas; a few simple principles based on the interaction of the organism and environment, that can explain a multitude of behaviors without invoking ideas like ‘thought’, or ‘emotion’ or ‘unconsciousness’.
Jean Piaget
1896-1980
My first cheat: Piaget was not a psychologist. His training was as a natural scientist. As a young man growing up in Switzerland, he was interested in fossils, shells and birds. However, after finishing his degree, he became interested in developing an ‘embryology’ of intelligence. Piaget initially planned to spend only a few years on this. He ended up spending 60 years observing children and their abilities, and formulating his highly influential theory of cognitive development. His ideas had a huge impact on developmental psychology, educational psychology and cognitive psychology. Ironically, Piaget, perhaps due to his own unusual childhood, while intellectually interested in the children he studied, never really engaged with them emotionally.
Abraham Maslow
1908-1970
Maslow, an American psychologist, was familiar with the two dominant forces in psychology during the mid-twentieth century: namely, psychoanalysis and behaviorism. Maslow felt that neither of these approaches adequately explained human experience. Behaviorism was founded on animal research which Maslow felt couldn’t have any real relevance to humans. Psychoanalysis seemed to focus on psychotic individuals and not healthy personalities. Maslow, by nature shy and reserved, felt strongly enough about this to lead the development of a new approach to psychology he called ‘third-force’ psychology. His psychology discarded research as not relevant to human beings, focused on what it takes to become mentally healthy, and paved the way for a number of approaches to therapy, developed in the sixties and seventies, of dubious utility. Depending on your perspective, Maslow either increased the scope of psychology or reduced its overall validity.
Max Wertheimer
1880-1943
Wertheimer was a German psychologist, fascinated by fact that what we often see is not what is present. For example, when we watch movies, we are actually watching several still pictures presented quickly in sequence. What we see is movement up on the screen. Wertheimer believed that our minds do something to the perceived image to create this apparent movement. His curiosity in this phenomenon led to the development of Gestalt psychology, and its focus on perception, cognitive insight and learning and dynamic social systems. Wertheimer had to leave Germany because of the rise of Nazism, and when he came to America, presented the only real competitor to the ideas of behaviorism that were so dominant at the time. The principles of Gestalt psychology were instrumental in the founding of social psychology and cognitive psychology. While it no longer exists as a separate discipline, many Gestalt principles have been integrated into other subfields of psychology.
Alfred Binet
1857-1911
During the late 1800s, ‘intelligence’ was conceptualized as a psychological quality passed on from one generation to another. What was needed was a way to successfully measure this particular quality. Binet was a French psychologist, approached by the French government to assist in developing a number of tests to discriminate between children of normal ability and children who needed extra educational assistance. In 1905, Binet and a colleague, Theodore Simon, developed their first attempt, called the Binet-Simon Test of Intelligence. It was based on a brilliant but simple idea. If you want to know if a child is ‘less intelligent’ than another, first see what a ‘normal’ child does and then observe how many of those tasks the child you’re evaluating can accomplish. This is the basic principle that all modern intelligence tests follow. Binet’s simple test was brought over to America and eventually revised to become the Stanford-Binet Test of Intelligence that is still being published and used today. But more importantly, Binet introduced the concept of successfully measuring psychological qualities that led to an absolute testing mania in the United States and other parts of the world. Few people have not been touched, for good or ill, by testing. Ironically, Binet would probably be appalled by the direction that testing has gone.
Wilhelm Wundt
1832-1920
Wundt is probably the most influential psychologist that no one has ever heard of. His influence did not lay in his ideas of psychology (his goal was to discover the ‘elements of thought’), or his methods of studying psychology (his one original contribution to methodology was probably ‘introspection’, which involved having subjects, somewhat subjectively, report their mental responses to different kinds of stimuli). No, Wundt is considered the founder of psychology. He was the first individual to call himself a psychologist, and to recognize that the work he was doing was part of a new discipline that hadn’t been labeled. Wundt was serving as the chair of the department of philosophy at the University of Leipzig, in Germany, when he began conducting his first psychological experiments, probably around 1879. His program of study was so successful that Germany became the center of psychology for a time (until a couple of world wars occurred). During the late 1800s, if you wanted to study psychology, there was no question that you must go to Germany, and many of the early psychologists traced their intellectual genealogy back to Wundt.
John Watson
1878-1958
Few famous men have started out so ignominiously. John Watson was the son of a drunkard who abandoned his family, and an extremely pious woman who made Watson promise to become a minister. Unfortunately, as a young man growing up in South Carolina, Watson was well on his way to juvenile delinquency. For some odd reason, (perhaps in the interest of pleasing his mother) Watson suddenly decided to go to college. Eventually, he graduated from the University of Chicago with its first PhD in psychology. Watson was dissatisfied with the current trends in psychology and believed only that which was directly observable could, and should, be studied. In 1912, Watson presented his ideas to the psychology community and in one broad stroke, swept away the old methodologies and presented his own. B.F. Skinner, as influential as he was, built his success on the foundation of Watson’s ideas. Watson is also well-known for his notorious ‘little Albert’ study and, even more notoriously, for carrying on an affair with his assistant in that work, Rosalie Raynor. The affair cost Watson his academic position in 1920 (times being what they were) and, like any good behavior modifier, he worked in advertising for the rest of his life.
Sigmund Freud
1856-1939
Here he is: the most well-known psychologist in history, and another cheat. Freud was not a psychologist; he was a psychiatrist (and, yes, there is a difference between the two). It is difficult to overestimate the influence that Freud’s ideas had over psychology and culture. His terms ‘ego’, ‘id’, ‘libido’ and others have entered everyday language, and his very name is synonymous with probing techniques that reveal the damage that your parents did to you when you were young, and dreams that are superficial covers for surging, uncontrollable desires. What may be perplexing to the layperson is that in modern psychology, Freud’s ideas are not taken very seriously. Most acknowledge that his ideas have little basis in reality, and were more the product of Freud’s highly creative and innovative imagination. So why is he so well-known? Whole books have been written on this subject but I would say his place on the list is due to a very basic, but at his time, completely new idea. This was the notion that mental disorders could be treated psychologically. Before Freud, doctors considered mental disorders to be the product of some physical aberration (and many of them are). Freud provided compelling anecdotal evidence for the psychological origin and treatment of many of these problems.
William James
1842-1910
James was an American psychologist who disliked the label. Morton Hunt, the science writer, described him as the psychologist malgre lui or the reluctant psychologist. James fancied himself more as a philosopher than a psychologist, and did very little experimentation in psychology. He was not impressed with the work of Wilhelm Wundt, and towards the end of his life focused on matters of religion and spiritualism. However, I place him in the number one position for one reason: in 1890, he wrote a book called ‘Principles of Psychology’ which is still in print today. It contains some apparently very modern ideas of psychology. In fact, a naïve reader would probably assume the book had been written in the last couple of decades not over 100 years ago. James essentially outlined modern psychology in this book. Wundt had proposed a psychology that focused, primarily, on the senses and perception. He rejected the notion that psychology could concern itself with some of the higher-order processes, like learning or problem-solving. James disagreed and outlined in his ‘Principles’ the idea that psychology could concern itself with issues like: emotions, habits, consciousness, self, adaptation and learning. Behaviorism has many of its roots in James’ ideas, as does concepts like ‘self-esteem, self-concept, clinical psychology, biopsychology’ and others. There are few topics in psychology that James didn’t anticipate, in one form or another. Interestingly, James was unsatisfied with the book. He wrote to the publishing company and described it as ‘a loathsome, distended, tumefied, bloated, dropsical mass, testifying to nothing but two facts: 1st, that there is no such thing as a science of psychology, and 2nd, that W. J. is an incapable’.
Observations
This list is highly biased and debatable. Of course, we assume the reader can discern the differences between the disciplines of psychiatry and psychology.
More here:
The List Universe
Avoiding Breast-Cancer Mistakes
How to make sure your diagnosis of early cancer is correct.
Damian Dovarganes MSNBC.com
Ductal carcinoma in situ (DCIS), the precursor to breast cancer, is identified much more often today, thanks to advances in imaging technology. But getting this diagnosis exactly right remains difficult. It’s not always easy for even expert pathologists to differentiate between normal cells and the tiny precancerous cells that may cluster in a woman’s milk ducts. These noninvasive cells represent such an early warning of cancer that they are known as stage zero.
That’s why, as an article on the front page of The New York Times reported yesterday, too often, women mistakenly diagnosed with DCIS have undergone disfiguring surgery and radiation to treat a cancer they never actually had.
So what’s the take-away message for women who want to avoid similar mistakes?
Understand that it can be challenging, even for experts in breast pathology, to get a DCIS diagnosis precisely correct. Cancer develops along a continuum that stretches from normal cells to aggressively invasive cells. ‘It’s not like you’re crossing a railroad track and the bar is either down or it’s not,’ says Dr. Charles Loprinzi, professor of breast-cancer research and a coauthor of the Mayo Clinic Guide to Women’s Cancers. ‘There are shades of gray.’
Even when doctors have correctly diagnosed DCIS, they often disagree about the kind it is because of very subtle differences in the patterns and structures the cells form. Pathologists like Dr. Ira Bleiweiss of Mount Sinai Medical Center in New York City, who specializes in breast cancer and does hundreds of consultations a year, says that about 40 to 60 percent of the time, he doesn’t agree entirely with the initial diagnosis. But, he adds, the difference of opinion is usually relatively minor and the treatment recommendation typically remains the same (such as removal of some more breast tissue). However, he says, in perhaps 10 percent of the cases, the difference is big enough to result in a different treatment strategy, and in less than 5 percent of cases, he sees a blatant error and changes a malignant diagnosis to a benign one (or vice versa).
To reduce the odds that you’re misdiagnosed, start by asking about the credentials of the pathologist who first reviewed your results, and whether he or she is a breast specialist. The College of American Pathologists is preparing to certify pathologists who review at least 250 breast biopsy results a year.
Proceed slowly. While quick action is sometimes required for a breast-cancer diagnosis, women who are told they have DCIS usually have at least a few weeks to double-check that the diagnosis is accurate before they have to make further decisions. ‘There are a lot of women who hear this diagnosis and say ‘I want you to take it out right away. I have a 2-year old who I want to see grow up,’’ Loprinzi said. But there is usually no reason to rush toward surgery or radiation.
Get a second opinion on your initial biopsy results from the best-qualified expert you can find. There are a limited number of pathologists who specialize in giving second opinions on breast cancer. Find one. Many are at medical centers affiliated with major academic institutions or large diagnostic centers. National and local breast-cancer support groups can help you find good referrals.
If there is no such specialized pathologist in your area, pathology slides can be mailed. To help the pathologist make the most accurate diagnosis possible, it’s a good idea to send a copy of the radiologist’s report as well as the X-ray he or she took of the core specimen after the biopsy. Some pathologists also like to review the mammogram films. Looking at all the data is sometimes necessary to get the diagnosis precisely right, says Bleiweiss, who is a professor of both pathology and oncological sciences, as well as chief of surgical pathology.
While some women diagnosed with DCIS will never go on to develop invasive breast cancer, there is currently—and, unfortunately—no reliable way to determine who will and who won’t, or how quickly it will progress. What doctors do know is that there are multiple types of DCIS, including low grade, intermediate, and high grade. If low-grade DCIS evolves into cancer, it will likely be low-grade invasive, and may never be deadly. But high-grade DCIS is likely to become the more dangerous high-grade invasive over time. Knowing what kind you have, and considering things like your age and other medical conditions, will help you make an informed decision about treatment.
Talk to several specialists before you decide on the type of surgery, the need for radiation, and follow-up care. While the standard way of proceeding is to remove the abnormal cells, radical surgery is rarely recommended in these cases.
In the meantime, research continues. There’s hope that in the future, drugs may be able to suspend or stop further progression of these cells and surgery will become less common. But in the short run, it would be extremely helpful if more pathologists were trained to be specialists in this area—and funding such fellowships should be a priority for breast-cancer philanthropies.
Frans de Waal on the human primate: Is it ‘behavioral sink’ or resource distribution?
By Frans B. M. de Waal Scientific American
http://www.scientificamerican.com/
Editor’s Note: This post is the second in a four-part series of essays for Scientific American by primatologist Frans de Waal on human nature, based on his ongoing research. (The first post, on our sense of fairness, can be read here.) De Waal and other researchers appear in a series of Department of Expansion videos focusing on the same topic.
In the 1960s Jack Calhoun placed an expanding rat population in a crammed room and observed how the animals killed, sexually assaulted and, eventually, cannibalized one another. The magnetism of the crowd and the behavioral deviancy led Calhoun to coin the phrase ‘behavioral sink.’
In no time popularizers were comparing politically motivated street riots with rat packs, inner cities to behavioral sinks, and urban areas to zoos. Warning that society was heading for either anarchy or dictatorship, Robert Ardrey, a popular science journalist and author of African Genesis, remarked in 1970 on the voluntary nature of human crowding and its ill effects. These views entered mainstream thinking: The negative impact of crowding became a central tenet of the voluminous literature on aggression.
In extrapolating from rodents to people, however, these writers were making a giant leap. Compare, for instance, the per capita murder rates with the number of people per square kilometer in different nations. If things were straightforward the two ought to vary in tandem, but there is in fact no statistically meaningful relation. Among free-market nations the U.S. is an anomaly by having the highest homicide rate despite a low population density. Some seek the explanation in U.S. gun laws, but this issue remains largely taboo.
To see how other primates respond to being packed together, we compared rhesus monkeys in crowded cages with those roaming free on Morgan Island in South Carolina. We also compared chimpanzees in indoor enclosures with those living on large forested islands. Nothing like the expected crowding effects could be found. If anything, primates become more sociable in captivity, grooming each other more—probably in an effort to counter the potential of conflict, which is greater the closer they live together. Primates are excellent at conflict resolution.
For the future of the world this means that crowding by itself is perhaps not the problem it is made it out to be. Resource distribution seems the real issue. This was already true for Calhoun’s rats, the violence among them could be explained by concentrated food sources and competition. Also for humans, I would worry more about sustainability and resource distribution than population density.
For more on this topic, see: Coping with Crowding by Frans de Waal, Filippo Aureli and Peter Judge; May 2000; Scientific American.
ABOUT THE AUTHOR
Frans de Waal, PhD, is a Dutch-American primatologist known for his popular books, such as Chimpanzee Politics: Power and Sex among Apes (1982) and The Age of Empathy: Nature’s Lessons for a Kinder Society (2009). He teaches at Emory University in Atlanta where he directs the Living Links Center at the Yerkes National Primate Research Center. He has been elected to the National Academy of Sciences and the Royal Netherlands Academy of Arts and Sciences.
The views expressed are those of the author and are not necessarily those of Scientific American.
Video credit: Department of Expansion
Snakes in the MRI Machine: A Study of Courage
What courage looks like in the brain–in real time
By Daniela Schiller Mind Matters
Scientific American
http://www.scientificamerican.com/
You are on a plane, thirty thousand feet above ground. Four hundred and fifty snakes crawl into the passenger cabin. You think this is terrifying? Hollywood producers certainly gambled on that when they released the 2006 summer blockbuster ‘Snakes on a Plane.’ Israeli scientists, however, have come up with an even creepier scenario.
You are in an MRI machine. Your head is fixed in a round cage. Your body is rolled into a narrow tube. Magnetic pulses are beamed into your brain. A meter-and-a-half-long snake is strapped with Velcro atop a small box on a conveyor belt just inches behind your head. Your eyes meet the snake’s beady gaze through a tiny mirror above your head. You can’t move.
Why would Uri Nili and Yadin Dudai, two scientists from the Weizmann Institute of Science in Rehovot, Israel, want to put a snake in the MRI scanner with you? Obviously, not to scan the snake’s brain (although this might be an interesting possibility). They wanted to scan your brain while you perform an act of courage. They wanted to push research on fear one step further – from understanding how we passively react to fear, through actively avoiding it, to actually confronting it.
FBI agent Neville Flynn (Samuel L. Jackson) could have been an ideal candidate for the experiment. Grabbing and fighting the snakes on the plane with his bare hands, Flynn came to the rescue of the passengers on red-eye flight 121. But there was no FBI or Mossad agent at the Weizmann Institute. The participants in the experiment had to face the snake on their own. All they had were two buttons. Pressing one would roll the snake closer. Pressing the other would slide it away. ‘Advance’ or ‘Retreat’, were their two options. They could choose either one, instructed only to do their best in pulling the snake toward their heads. ( See the video here.)
‘Courage,’ wrote Mark Twain, ‘is resistance to fear, mastery of fear, not absence of fear.’ And so, the participants who chose to ‘Advance’ the snake closer and closer to the backs of their heads did it despite being afraid. They were now scientifically courageous and their courage was quantitative and measurable (in ‘Snake-Advance’ units).
With those courage units in hand, Nili and colleagues thoroughly scrutinized the participants who were sliding the snake back and forth. They measured their brain activation with the MRI scanner, hooked them up with electrodes to measure how much they were sweating, and gave them questionnaires to fill out about how fearful and anxious they felt.
The results, reported in Neuron, revealed an interesting dissociation between fear reactions, a sort of internal disagreement paving the way to courageous acts.
Fear of the snake manifests itself in two ways – either you simply say, ‘I’m afraid,’ or your body says it for you, with sweat. When Nili and colleagues analyzed the questionnaires (in which participants rated their level of fear) and the electrical resistance of the skin (indicating how much they sweated), they realized that the two facets of fear do not always go together.
You could say that you are not afraid but sweat a lot, or say that you are freaked out and sweat not at all. But here is the interesting thing: as long as these two disagree, you would act courageously. It is only when you scored high on both, sweat and fear, that you would succumb to cowardice. It is as if you have two brakes. Release either one, and you could drive on.
Where is this driver in the brain? Imagine you stick a pencil straight into the bridge of your nose between your eyes. You push it in and stop right before the line between your ears. There it is, a brain region called the subgenual anterior cingulate cortex (sgACC, to make it short).
The sgACC was the only part of the brain whose activation went hand in hand with courageous acts. Bringing the snake closer to the head strongly activated the sgACC. The more the participants were afraid but did not succumb to fear, the more active was their sgACC, as if more ‘mental effort’ was required to act in the face of fear.
When they did succumb to fear, another region came into play: the amygdala, an area known as a seat of primitive fear, among other things. (To find it, now imagine you take two pencils, stick one in your eye and the other in your ear; the amygdala is where the pencils meet). Only a strongly active sgACC silenced the amygdala.
The mechanics of courage in the brain, it seems, involves a competition. When fear reaches a certain threshold, pushing both your subjective feeling of it and your bodily sweat, you would succumb. Your amygdala drives that fear, but internal disagreement overcomes it. The agent behind this disagreement is the sgACC. It acts to control and suppress bodily fear responses, and sends nerve projections into the amygdala that shut it down.
Why should we care about this? Of course there is a ‘brain correlate’ to whatever we say, think, or do. So what? Well, every car can break down and so does our brain. Sometimes the brakes in the brain are stuck and you are perpetually petrified. Knowing how the brain works up the courage to confront fear could help. Perhaps someday, to help people with anxiety disorders, we could inject drugs, insert electrodes, or just train the brain to act differently. With this knowledge, perhaps, eventually, fear will not prevail.
Does finding a basis for courage in the brain cast a shadow on the great heroes of history? Were they merely men of great and powerful sgACCs? Such a conclusion would be way overboard. There is no evidence for actual genetic, anatomical or physiological differences between the sgACCs of the brave and the fearful. Perhaps any sgACC could work up enough courage. We don’t know. But more importantly, do we really care?
What matters is that we have seen courage at work in the brain, and we all have the same basic neural equipment. From this point on, it’s up to us. Perhaps one day there will be a ‘courage pill’ or maybe we could electrically stimulate the sgACC to boost up our courage. Whether we choose to do this or not is a matter of broader social and ethical debate over our growing ability to fiddle with the plasticity of the brain. At least, if we choose to try to enhance courage, we now know where to begin.
Oh, and one final note: no snakes were harmed in the course of the experiment.
Further Reading
Challenging Cancer: A Stressful Lifestyle Reduces Tumor Growth in Mice
Vaccines Derived from Patients’ Tumor Cells Are Individualizing Cancer Treatment
Slick Solution: How Microbes Will Clean Up the Deepwater Horizon Oil Spill
Recommended: The Encyclopedia of Weather and Climate Change: A Complete Visual Guide
How Breastfeeding Benefits Mothers’ Health
Dual screening pinpoints cancer in women
Posted By Megan Fellman-Northwestern
Combining a common colon cancer screening test with novel optical technology may allow doctors to more accurately detect the presence of colon cancer, particularly in women.
Researchers combined a polarization-gating optical probe alongside traditional flexible sigmoidoscopy to measure the early increase in blood supply in rectal tissue as a marker for colon cancer.
Details appear published this month in the journal Cancer Prevention Research.
Flexible sigmoidoscopy is a widely available screening technique that is approved by major guideline organizations. During a flexible sigmoidoscopy exam, doctors use a thin, flexible tube to examine the lower third of the colon.
The procedure is an attractive screening mechanism for colon cancer because the test is quick and affordable, can be conducted by a primary care physician and requires simpler bowel preparation than that of a colonoscopy.
However, the test isn’t as widely used for colon cancer screening because it only examines a third of the colon, compared to the full colon examination conducted during colonoscopy.
While colon cancer strikes roughly as many women as men, there are significant differences in how the disease presents itself, researchers say.
Women are more likely to have cancerous lesions in the proximal colon, the section of the colon furthest away from the rectum—and the part of the colon that isn’t examined during flexible sigmoidoscopy.
Due to this discrepancy, previous studies found that flexible sigmoidoscopy alone detected only one-third of colon cancer in women.
A 2009 study in the Annals of Internal Medicine called into question the effectiveness of colonoscopy in detecting proximal colon cancer, which raises concern about the disparity between the effectiveness of colon cancer screening techniques for men and women.
Given women’s proclivity toward proximal tumors—the hardest to detect using current technologies—researchers are seeking to develop even stronger screening techniques for women.
‘Because women are particularly likely to develop cancer in the proximal colon—the hardest to detect—there is a disparity in screening for colorectal cancer in women,’ says Hemant Roy, director of gastroenterology research at NorthShore University HealthSystem.
‘This study is one of several efforts to apply new technologies to improve our ability to detect cancer, specifically in women.’
The researchers hoped that combining the test with an optic probe that measures how light scatters through tissue would provide a way to measure very subtle changes in the tissue that can indicate the presence of cancer in the organ.
The technology makes use of a biological phenomenon known as the ‘field effect,’ a hypothesis that suggests the genetic and environmental milieu that results in a neoplastic lesion in one area of an organ should be detectable throughout the organ and even in neighboring tissue.
‘Using these optical techniques, we can identify very subtle changes in tissue that appears to be normal when examined using traditional techniques,’ says Vadim Backman, professor of biomedical engineering at Northwestern University. [3]
‘This increased level of detail allows us to discover new markers for disease, which we hope will provide new methods to identify cancer in its earliest stages.’
In the study of 366 male and female patients, researchers found the performance characteristics of the test to be very promising. The technique identified with 100 percent accuracy each person who had a neoplasia in the proximal colon.
Some people were identified who did not have a tumor; it is uncertain whether this is a false finding or if it means those people could be at risk for developing cancer and need to be watched closely.
When comparing the results for each gender, researchers found that the early increase in blood supply was a particularly robust marker for proximal neoplasia in women, providing hope that the technique could provide a mechanism to improve possible discrepancies in the accuracy of colon cancer screening between men and women.
‘Our hope is not to replace the colonoscopy, but to develop better screening techniques to determine who needs a colonoscopy,’ says Backman.
‘If we can develop something that can be used by a primary care physician, we can vastly increase the number of people who are screened, and ultimately treated, for this disease.’
The National Institutes of Health supported the research.
More news from Northwestern University:
www.northwestern.edu/newscenter/index.html
Skull tells tale of the lost primates of the Caribbean
PITY the mammals living on lush Caribbean islands. Over the last 12,000 years, they have suffered the highest extinction rates of any on Earth. Now, a primate skull found in an underwater cave on Hispaniola underscores what we have lost – a fauna so primitive and strange that the archipelago has been likened to Madagascar.
Today, there are no primates in the Caribbean, and it wasn’t until 1952 that palaeontologists accepted that the islands had once been home to monkeys.
The new find – the first well-preserved skull from Hispaniola (see picture) – confirms that this monkey was related to a group of primates still found in Central and South America that includes capuchins and squirrel monkeys. But although the skull is only a few thousand years old – too young to be called a fossil – the rear of its braincase is unlike that of any modern monkey. Instead, it most resembles a monkey that lived 16 million years ago in modern-day Argentina (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2010.1249).
Such ‘undercurrents of primitiveness’ in a recently extinct monkey suggest parallels with Madagascar, says Alfred Rosenberger at the City University of New York, whose team described the new skull.
Madagascar’s lemurs belong to the strepsirrhines, a group of primates now relatively rare in Africa. Just as they reveal what the archaic strepsirrhines of Africa would have looked like long ago, the recently extinct Hispaniola monkey (Antillothrix) could be a window onto South America’s ancient monkey fauna, says Rosenberger.
Because they have been isolated from mainland Africa for so long, many of Madagascar’s primates have famously evolved bizarre features. Rosenberger says that the same is true of the Caribbean’s lost monkeys. The extinct Jamaican monkey (Xenothrix), for instance, can ‘loosely’ be compared to the Aye-aye, a peculiar Madagascan primate with rodent-like incisors and a long finger for extracting insects from beneath bark.
And the limbs of the Cuban monkey (Paralouatta) suggest it spent at least part of its life on the ground, not in the canopy, says Rosenberger – something no living New World monkey does.
Ross MacPhee at the American Museum of Natural History, New York, says the Hispaniola skull is an important discovery. He used to think that a single monkey species, likely an ancestor of modern Titis, reached the Caribbean by chance, giving rise to all of the region’s monkeys. The morphology of the new skull doesn’t support this scenario, so he now agrees several species crossed the ocean to reach the Caribbean from South America.
In fact, he has geological evidence to suggest that around 33 to 35 million years ago, a thin land bridge called Gaarlandia would have offered ancient primates a dry route into the region (see map, right). If so, then the monkeys arrived in the Caribbean 10 million years earlier than the oldest fossils yet found.
When this article was first posted, the first sentence of the sixth paragraph read: ‘Because they have been isolated from mainland Africa for so long, many of Madagascar’s monkeys have famously evolved bizarre features.’
IN THE WILD AND IN THE LAB, OCTOPUSES EXHIBIT REMARKABLE BEHAVIOR THAT HINTS AT SOPHISTICATED INTELLIGENCE. SHOULD THEY BE TREATED DIFFERENTLY FROM OTHER ANIMALS?
By Dave Munger Seed Magazine
http://seedmagazine.com/content/print/are_octopuses_smart/
Imagine being trapped in a small pressurized underwater chamber (like a diving bell) where you were fed once a day by an octopus that tossed food in from the opening in the floor. Each day an octopus also reached in to poke you gently with a stick. Suppose this went on for two weeks. Do you think you’d be able to figure out that there were actually two octopuses—one ‘poker’ and one ‘feeder’? Would you be able to tell the difference between the two?
Octopuses are so different from humans that it might actually be rather difficult for you to tell them apart—especially since you would only be able to see them through the distorting lens of the water. On the other hand, if you did manage to figure out which octopus was which, you might be able to get out of the way of the stick when the ‘poker’ showed up. You also might be able to demonstrate to the octopuses that you were ‘intelligent,’ perhaps inspiring them to treat you better while in captivity.
Obviously this is just a thought experiment, and the real research was done in reverse, but hopefully this example gives you some sense of how difficult the problem of octopus intelligence really is. Because octopus brains evolved independently from human brains, their anatomical structure is very different from our own, so understanding whether octopuses are ‘intelligent’ is not a simple task. How would you tell if an eight-legged alien from another planet was intelligent?
Earlier this month, Mike Lisieski, a student at the University of Buffalo who blogs about octopuses and other cephalopods, discussed an attempt to assess octopus intelligence that was published in this month’s edition of the Journal of Applied Animal Welfare Science. Eight wild octopuses were fed or gently poked by one of two identically-clad researchers at the Seattle Aquarium, and after two weeks, the octopuses responded differently to the ‘feeder’ and the ‘poker’ when they approached the tank without food or sticks. This suggests that octopuses can recognize different humans. Although Lisieski points out that the task isn’t very authentic and could have been made more difficult by clothing the humans differently each day, nonetheless it’s quite impressive that octopuses can do it at all. Wouldn’t it be easier to shrink away from any approaching human, on the chance that it might turn out to be a harasser?
And octopuses have other impressive abilities that appear to signal intelligence. Texas biologist Zen Faulkes discussed a report published last year in Cell, in which researchers observed octopuses carrying coconut shells around, then later using them as hiding places. This seems to be an example not only of tool use, but anticipatory tool use, which has long been believed to be a mark of intelligence. Faulkes has worked with Jennifer Mather, who is known for research on cephalopod consciousness (PDF link). Mather has observed octopuses modifying their dens in a similar fashion, so there’s converging evidence that octopuses are relatively smart. That said, even ants and bees make complex homes for themselves, so that behavior alone may not be enough to qualify as ‘intelligence.’
Large octopuses have relatively large brains, with hundreds of millions of neurons. That doesn’t put them in league with humans, with perhaps 100 billion, but octopuses also have a tremendous number of neurons in their tentacles—more than in their brains, says biology researcher Hannah Waters. If an octopus’s nervous system is so radically different from ours, then isn’t it possible that octopus ‘intelligence’ is different from human intelligence as well?
More on Cephalopod Intelligence from ResearchBlogging.org:
Zen Faulkes asks whether Octopuses.
Alistair Dove gives the lowdown on cephalapod vision—how good is an octopus’s eyesight?
Neil O’Connell discusses the case of Paul the ‘Psychic’ octopus, and what.
Waters points out that octopuses have been observed doing a number of ‘intelligent’ things, like opening screw-top jars, crawling from one tank to another to get a snack, or being trained to solve puzzles. Psychology graduate student Jason Goldman adds that octopuses have sophisticated visual navigation strategies. Does that make them ‘intelligent?’ After all, ants have great navigation skills, too.
Like other cephalopods, octopuses respond to polarized light—and they produce polarized light patterns by changing their skin pigmentation, says Lisieski. Does this mean they might actually communicate with each other using skin-pigment changes? We don’t know. But even if they do communicate with skin pigment, that doesn’t demonstrate that they are any smarter than birds communicating with songs, or dogs communicating with growls and barks.
In short, at this point the evidence of octopus intelligence doesn’t show that we should treat them differently from many other creatures that many humans routinely kill and serve for dinner. Yet the fact that octopuses are so different from us also opens a world of questions: What does ‘intelligence’ mean to a cephalopod? Nearly everyone agrees that we shouldn’t kill or eat apes; are there other creatures that are equally deserving of our mercy? Is intelligence the key element in how we should treat other animals, or do other rules apply? Maybe any creature with consciousness—and by some definitions, this includes not only cephalopods, but every mammal that has been tested—should be given some rights. Lisieski is sympathetic to many arguments in favor of animal rights, but he’s not sure the search for ‘intelligence’ will ultimately offer any insight. If we accorded rights for every clever act, and removed them for every stupid one, many humans might not qualify for rights most of us believe are fundamental.
Dave Munger is editor of ResearchBlogging.org, where you can find thousands of blog posts on this and myriad other topics. Each week, he writes about recent posts on peer-reviewed research from across the blogosphere. See previous Research Blogging columns »
Some links
|
|
|
Health News Headlines |
|
|
• Most Kids With ADHD Take Medicine |
|
|
In the Spotlight |
|
|
• The Loneliness of Living With a Chronic Illness |
|
|
From the WebMD Network |
|
|
• Could Ovarian Cysts Lead to Ovarian Cancer? |
|
|
From Our Sponsors |
|
|
• Help Protect Your Preteen by Learning About These 4 Diseases Social web: The great tipping point testMark Buchanan New Scientist Editorial: Don’t fear the tweeter: your data trail is doing good Your online traces are helping fuel a revolution in the understanding of human behavior – one that’s revealing the mathematical laws of our lives EVERY move you make, every twitter feed you update, somebody is watching you. You may not think twice about it, but if you use a social networking site, a cellphone or the internet regularly, you are leaving behind a clear digital trail that describes your behavior, travel patterns, likes and dislikes, divulges who your friends are and reveals your mood and your opinions. In short, it tells the world an awful lot about you. Now, as any researcher will tell you, good data is gold dust. Its absence leaves theories in the realm of speculation, and worse, poor data can lead you down blind alleys. Physics was the first science to be transformed by accurate information, first with telescopes that revealed the heavens and culminating in massive modern-day experiments like the Large Hadron Collider at CERN, near Geneva, Switzerland. Biology was next, with genome sequencing throwing up so much of the stuff that genetics has turned partly into an information science. Now the study of human behavior is heading the same way. Social scientists have long had to rely on crude questionnaires or interviews to gather data to test their theories; methods marred by reporting bias and small survey sizes. For decades, the field has been looked down upon by some as a poor cousin to the hard sciences. The digital age is changing all that - practically overnight, the study of human behavior and social interactions has switched, from having virtually no hard data to drowning in the stuff. As a result, an entirely different approach to social science has emerged, and studies based on it are appearing with increasing frequency. The impact has been remarkable. ‘The data revolution is here for social science,’ says Albert-László Barabási of Northeastern University in Boston. ‘For the first time, scientists have a chance to study what humans do in real time and in an objective way. It’s going to fundamentally change all fields of science that deal with humans.’ The data revolution is here for social science. For the first time we can study what humans do in real time It is becoming possible to tackle fundamental problems previous generations have thought largely untouchable. As with every other data-rich science, Barabási and his ilk ultimately hope to discover mathematical laws that describe human behavior, and which could be used to predict what people will do. Sociologists have been hunting for such laws about human interactions and social networks for decades, says Duncan Watts of Yahoo Research in New York, ‘but the far-reaching implications of their theories have been effectively impossible to test. The measurement technology simply didn’t exist’. That’s changing. Watts was among the first to realize the potential of the digital trail we leave behind. In 2006, with his colleague Matthew Salganik, now at Princeton University, he designed a web-based experiment to examine how much social influence determines the popularity of music. When a new song goes straight to number 1, it’s hard to know if its success has come from the song’s inherent appeal, or instead from the herd-like behavior of many people buying songs they think are already popular. The music industry has had little success in predicting which songs will do well and which won’t, suggesting that a lot might be down to chance. To examine what made some songs more successful than others, Watts and Salganik created a project called Music Lab. It featured a website where more than 14,000 people listened to any of 48 songs by relatively unknown bands, rated them, and downloaded them if they wanted. These options provided a measure of quality (the average rating given) and popularity (the number or downloads). Crucially, the duo were also able to control whether listeners could see how many times other people had downloaded any particular song, or instead had to rely solely on their own judgment. In this way, they could effectively compare outcomes with the power of social influence turned on or off. They also grouped the socially influenced participants into eight independent ‘worlds’ so that they could explore how the outcomes - the popularity rankings of the various tunes, based on downloads - might change if the tape of history could be rewound and run again. The results strongly support the idea that human influence has a huge effect in making some songs more popular than others. This factor also makes it much harder to predict what will happen, and which songs will do well. The worlds in which social influence was operating had much higher inequality - with popular songs going up and unpopular songs going down to an even greater extent than in the worlds lacking social influence. With social influence turned on, song popularities fluctuated wildly between one world to the next. So, like it or not, it seems like many of us follow the herd. Watts and Salganik concluded that so-called experts fail to predict successes not because they are incompetent or misinformed, but because social influences multiply chance effects into lasting differences. Accidents determine the song at the top of the chart as much as true quality. Though quality does count, Salganik points out. The songs rated as the best rarely did poorly, and those rated as the worst rarely did well, but any other result was possible. These kinds of experiments are making routine the types of experimental studies which were once thought impossible, says Salganik. ‘With the vast increase in computing power and the almost limitless pool of participants now available via the internet, we can conduct laboratory-style experiments involving thousands, or even millions, of participants,’ he says. Indeed, Jukka-Pekka Onnela and Felix Reed-Tsochas at the University of Oxford’s Saïd Business School are now using Facebook and its 400-million-plus users as a living laboratory to examine how ideas and behaviors spread through human groups. Watts and Salganik showed that when it comes to music preference, we behave like sheep. Social scientists have long wondered whether other social transformations - including everything from the popularity of a politician to a change in behavior to mitigate climate change - arise through independent, individual choice, as many people simultaneously come to similar decisions, or instead through influence, as people copy others’ behaviors. Onnela and Reed-Tsochas realized that analogous changes take place in Facebook, on which people share their profiles with their online friends. Facebook users can also choose to install applications - software components that personalize their Facebook page. If one person adopts an app, their friends are automatically notified, and they can also see the apps their friends are using. Facebook users also have access to a list of popular applications, akin to a best-sellers list. So far, so high-street bookstore, but there’s one huge difference: the data stored on Facebook makes it possible to analyze the growth in popularity of individual applications in unprecedented detail. Onnela and Reed-Tsochas analyzed the popularity of several thousand applications in 2007, shortly after those apps were introduced, and then studied how other users adopted them over time. They looked to see if the sequence of adoptions for each app followed an essentially random pattern - indicating that each ‘adoption event’ was independent of other previous adoptions - or whether previous adoptions by a participant’s friends influenced the likelihood of their subsequent adoption of an app. Explosive growth The results showed that both independent thinking and copying behavior play a role, reinforcing conclusions reached by conventional survey methods. However, the study also indicated there are two very different processes in action. On the one hand, their analysis shows, at first, when a new app appears it is adopted by users independently of their friends’ opinion. But if the popularity of an app crosses a threshold, its very popularity then seems to draw many people to adopt it, and its growth can become explosive. Just as Watts and Salganik found in their Music Lab experiment. ‘We found very distinct regimes in which individual or collective behavior dominates. The change from one to the other is a sharp on/off process,’ says Reed-Tsochas. They don’t yet know whether tipping points of this kind might influence real-world processes beyond the web, such as shifts in political opinions or the popularity of books. ‘It’s certainly possible,’ says Reed-Tsochas, ‘but we’ll need to wait for equally good data in those areas to find out.’ Some say the raw information for analysis of real-world behavior is already there in the burgeoning online social networks, and have even shown how it can be used to predict social outcomes. For example, one of the most popular techniques for predicting anything from presidential elections to the box-office success of new movies is by using artificial markets. The Hollywood Stock Exchange (hsx.com) enables movie fans to buy and sell virtual shares in celebrities and in forthcoming or recently released films. This virtual market, which operates with a virtual currency called Hollywood dollars, incorporates the views of millions of people into a stock rating for each film, reflecting the aggregate view on its popularity, or likely popularity. ‘This is currently the gold standard in the industry for predicting likely box office receipts,’ says Bernardo Huberman at Hewlett Packard Laboratories in Palo Alto, California. Huberman and his colleague Sitarum Asur wondered if it might be possible to do even better by exploiting the enormous volume of opinion expressed through social media such as Facebook and Twitter. Opinions voiced in these media, they reasoned, should have strong predictive power because they actually play a role in determining which films do well. ‘What gets discussed through these media often ends up setting trends,’ says Huberman. In an attempt to mine these opinions, they studied the chatter on the microblogging site Twitter. They started from the supposition that movies that get talked about a lot - that generate a lot of buzz - should end up being more popular. To measure the buzz for each film, they looked at the rate at which it generated tweets immediately following its release. They used this as a predictor of the ultimate film sales. The results show that the rate at which movie tweets were generated can provide accurate predictions of box-office revenue, more accurate even than the Hollywood Stock Exchange. In the end, predicting successful movies may only be of interest to film companies and investors. But Asur and Huberman reckon this is just the beginning, and that their technique should be able to predict social outcomes of many kinds. ‘When properly tapped, social media express a collective wisdom which can yield an extremely powerful and accurate indicator of future outcomes,’ says Asur. Huberman says such analyses could soon help predict many other events, such as election outcomes, or quickly gauge public reactions to major events, just as long as we have evidence reflecting peoples’ views on the relevant issue. ‘Twitter and texting in general were influential in the election of Barack Obama and some businesses are already analyzing these kinds of data to assess the likely success of their products,’ says Huberman. The ocean of digital information about us isn’t limited to opinions. Though it’s still controversial, and difficult to get hold of, some teams are accessing much more personal details. For example, Barabási and his colleagues at Northeastern University used cellphone data to analyze human movements - how we move about over hours, days, weeks and months by walking, driving and public transport in all its forms. Detailed data on the scale now available never existed before cellphones became commonplace. Now millions of people carry a de facto tracking device with them all day that automatically logs their every move. You’re so predictable The dataset the team used covered the movements of about 50,000 people over three months. Surprisingly, the team found that, despite our myriad individual differences and diverse daily routines, the overall statistics of our movements follow a mathematical pattern - and we’re far more predictable than you might think. What’s more, they found that analysis of past data on movements can be used to predict where an individual will be - to within 1 kilometer of a cellphone tower - even during the more variable parts of their day, with an accuracy of over 90 per cent (Science, vol 327, p 1018). ‘We found the same high level of predictability across all users,’ says Barabási. That’s perhaps not so surprising as for most of the day, most of our movements are pretty routine, moving from home to work and back, however, this ability to predict your location holds true even for those people who move around more than just the typical home-work-home commute. This study builds on earlier work in which Barabási and colleagues used cellphone data to explore the patterns of human movements (Nature, vol 453, p 779). There they found that individuals generally travel lots of relatively small distances, but occasionally take long excursions that move us to very different territory. The precise details of the statistics of such movements follow a mathematical pattern - known as a Levy flight - which turns out to be closely linked to the ways animals such as deer, bumble bees and birds forage for food. Mathematically speaking, our movements turn out to be strikingly like those of other organisms. So we’re not so special, at least in this regard. ‘There are a lot of details that make us different,’ says Barabási, who has found convincing evidence that most of our actions are driven by laws, patterns and mechanisms that rival the reproducibility and predictive power of those encountered in the natural sciences. It’s the discovery of underlying patterns of this kind that has excited so many scientists. Given the undeniable complexity of individual human beings, it’s not as if social science is going to become like physics, grounded in eternal and general laws, but access to data on human events makes it possible to identify the patterns that do exist and these can be useful for demystifying the social world. However, as with some developments in physics and biology, the social data explosion also brings with it new risks, says Barabási. ‘Anyone involved in this kind of research increasingly faces a dilemma - how do we avoid contributing to the creation of a surveillance state?’ Such worries are, perhaps, another sign that social science is finally coming of age. Just as the discovery of nuclear fission raised moral dilemmas for physicists, and genetic modification is now doing for biologists, so the ability to predict human behavior is presenting new quandaries for social scientists. As ever, with great power, comes great responsibility. Mark Buchanan is a science writer based in France |
Si le ha gustado esta entrada, por favor considere dejar un comentario o suscríbase al feed y reciba las actualizaciones regularmente.
Comentarios
14 respuestas a “Links, articles, obesity, cancer and more, just dig in…”Trackbacks
- Links, articles, obesity, cancer and more, just dig in… | Sistema … edu university
- Latest Breast Cancer Articles Auctions | Uncategorized | Informative Articles about Cancer!
- Twitter Trackbacks for Links, articles, obesity, cancer and more, just dig in… | Sistema Limbico [monografias.com] on Topsy.com
- Colon Cancer Can Be Beaten | Acai Berry Colon Cleanse
- What’s so funny about breast cancer? | Breast cancer Blog
- Mental Disorders 101
- Healthiness For Life » fat guy on bike
- How to Tackle Breast Cancer Successfully? | Breast Implant Procedure
- Men feel like Arnie, but are really Homer
- Links of London – Links of You and Me | 1 Day Wristbands
- Foot Problems 101
- Asbestos Cancer Lawyer San Diego – Treatment Information | Cancer information Blog
- World Wide News Flash
- How To Loose Body Weight – Burn Fat – How To Lose Belly Fat And Get Abs | tea house
Deje su comentario
Debe iniciar sesión para dejar un comentario.
