News 19 juni 2009
Research Uncovers Clues to
Virus-Cancer
In a series of recently-published articles, a research team from the University of North
Carolina at Chapel Hill Lineberger Comprehensive Cancer Center has uncovered clues to the
development of cancers in AIDS patients.In an April article published in the journal PLoS
Pathogens, Dirk Dittmer, Ph.D., associate professor of microbiology and immunology at UNC’s
School of Medicine, demonstrated that the Kaposi sarcoma associated herpesvirus (KSHV) is
not only present in every tumor cell, but that the cells also transcribe microRNAs (miRNA)
from the virus. This represents a collaborative effort between UNC researchers and
clinicians at Beth Israel Hospital, the University of Miami and the Federal University in
Bahia, Brazil. MicroRNAs are small molecules that regulate gene expression. Scientists
have hypothesized that viruses can cause cancer through a mechanism where the viral genes
take over the cell and induce cancerous growth through alteration of cell miRNA, since
certain kinds of miRNA are responsible for putting the ‘brakes’ on uncontrolled
cell growth. Dittmer’s team examined samples of tissue provided with the consent of
Kaposi’s sarcoma patients and found that specific miRNA biomarkers accurately
identify stages of tumor progression. They found that certain miRNAs were lost as the
tumors progressed, effectively accelerating the cancer’s growth. More aggressive
tumor stages expressed higher levels of KSHV miRNA.
New Cortex Study Uncovers How We
Recognize What is True and What is False
A recent neuroimaging study reveals that the ability to distinguish true from false in our
daily lives involves two distinct processes. Previous research relied heavily on the
premise that true and false statements are both processed in the left inferior frontal
cortex. Carried out by researchers from the Universities of Lisbon and Vita-Salute, Milan,
the June Cortex study found that we use two separate processes to determine the subtle
distinctions between true and false in our daily lives. Deciding whether a statement is
true involves memory; determining one is false relies on reasoning and problem-solving
processes.
The bitter side of sweeteners
Sewage treatment plants fail to remove artificial sweeteners completely from waste water.
What's more, these pollutants contaminate waters downstream and may still be present in
our drinking water. Thanks to their new robust analytical method, which simultaneously
extracts and analyses seven commonly used artificial sweeteners, Marco Scheurer,
Heinz-Jürgen Brauch and Frank Thomas Lange from the Water Technology Center in Karlsruhe,
Germany, were able to demonstrate the presence of several artificial sweeteners in waste
water. Their findings are published online this week in Springer's journal Analytical and
Bioanalytical Chemistry. A range of artificial sweeteners are commonly used in food and
drinks, as well as drugs and sanitary products. The potential health risks of artificial
sweeteners have been debated for some time. Until now, only sucralose has been detected in
aquatic environments. Through the use of a new analytical method, the researchers were
able to look for seven different artificial sweeteners (cyclamate, acesulfame, saccharin,
aspartame, neotame, neohesperidin dihydrochalcone and sucralose) simultaneously, and show,
for the first time, that a number of commonly used artificial sweeteners are present in
German waste and surface water.
We have discovered the first genes
intervening in brain metastasis
Joan Massagué (Barcelona, Spain, 1953) is the first winner of the BBVA Foundation
Frontiers of Knowledge Awards in the Biomedicine category. The Frontiers of Knowledge
Awards are intended to recognize and promote research of excellence. The breadth of
disciplines addressed and their monetary amount – a combined purse of 3.2 million
euros spread over eight prize categories – place them among the world’s foremost
award schemes. Massagué is Spain’s most widely cited working scientist, with his
papers referred to on more than 62,000 occasions. His studies, with great potential for
clinical application, are opening up fundamental new pathways in the fight against cancer.
He has conducted pioneering research into the genetic and cellular bases of metastasis and
remains an acknowledged leader in this field. His group’s latest findings, published
in the May edition of Nature, explain how tumor cells manage to enter the brain and form a
new tumor. Until now, scientists were baffled as to how cancer cells were able to breach
the blood-brain barrier which normally protects the brain from harmful substances.
Massagué has identified three genes that intervene in the process, but the list will go
on and work will continue to determine which is most important in each type of cancer.
Protein in the envelope enclosing
the cell nucleus - a new piece of the puzzle in research on cancer and stem cells?
A research team led by Professor Einar Hallberg at the Department of Life Sciences at
Södertörn University in Sweden has discovered a new protein in the inner membrane of the
cell nucleus. This protein may play an important role in cell division and now provides a
new piece of the puzzle to study in cancer research. All living organisms are made up of
cells. The cell consists of different "compartments" that have different
functions. In one of the compartments, the cell nucleus, there is genetic information
about how the organism's proteins should look like, and when they should be produced. The
cell nucleus is enclosed by a double lipid membrane that is called the nuclear envelope.
All transports in and out of the nucleus take place through pores in the nuclear envelope.
It is estimated that there are some 100 different proteins in the nuclear envelope, but
today scientists do not yet know precisely how they function.
How much chronic depression with
medical disorders affect work performance?
A group of Australian researchers investigated in medical disorders the effects of
comorbid dysthymic disorder as compared to major depressive disorder (MDD) on
health-related quality of life (HR-QoL) and disability days in the general population. In
a population-based study 4,181 individuals were assessed for the presence of dysthymic
disorder and depression, utilizing the Composite International Diagnostic Interview. Each
participant received a thorough medical examination to assess the presence of comorbid
somatic conditions. HR-QoL was evaluated using the Medical Outcomes Survey Short-Form 36
(SF-36) and disability days were provided by self-report. Descriptive statistics, analysis
of variance and multivariable logistic regression were used. Comorbidity with illnesses
from a maximum of 6 somatic disease groups was more prevalent in persons with dysthymic
disorder (78.7%) than in those with MDD (70.4%). Persons with dysthymic disorder had a
significantly lower mental health summary score in the SF-36 and more disability days than
those with MDD. The physical health summary scores were not significantly different
between participants with dysthymic disorder and MDD (after Bonferroni correction),
suggesting that limitations in physical functioning due to comorbid medical conditions
were similar in both affective disorder groups.
Histamine affects alcohol-related
behaviour
The histamine-3 receptor is important in terms of alcohol-related behaviour, and a drug
affecting that receptor may have qualities that alter alcohol-related behaviour. This
appears in the study headed by Pertti Panula entitled “Tuberomamillary nucleus
neurons, histamine and H3 receptor in hypothalamic regulation of alcohol addiction”
which is part of the Substance Use and Addictions research programme of the Academy of
Finland. “Whether these histamine-3 receptor drugs help in the treatment of human
alcoholism will probably be clear when the results of the currently ongoing clinical
trials become public. The drugs are currently being tested for the treatment of conditions
such as observation disorders, sleep disorders and narcolepsy,” says Professor
Panula. In addition to the well-known dopamine and serotonin, neurotransmitters that are
important to the functioning of the brain also include histamine, which is better known
for the regulation of allergies and stomach functioning. The histamine system of the brain
is important in the regulation of the sleep-waking rhythm. There is also an extensive
histamine system in the human brain.
What the Immune System Reveals
about Breast Cancer
Researchers working with Dr Marcus Schmidt in the Department of Obstetrics and Gynecology
at the University Medical Center Mainz have unlocked the key to the immune system's
significance in cases of breast cancer, thus identifying its long-neglected role in the
prognosis of the disease. Their research results, published in the renowned Cancer
Research journal, show that patients with certain breast tumors have a better prognosis
when more immune cells are present in the tumor. These results permitted the scientists to
extend the "coordinate system" in case of breast tumors to include the immune
system as the third important reference point for the prognosis of this disease, in
addition to the long-established prognostic factors of estrogen receptor expression and
proliferative activity (Cancer Research, 1 July 2008; Cancer Research, 1 April 2009).
Farmed fish may pose risk for mad
cow disease
University of Louisville neurologist Robert P. Friedland, M.D., questions the safety of
eating farmed fish in today’s Journal of Alzheimer’s Disease, adding a new worry
to concerns about the nation’s food supply. University of Louisville neurologist
Robert P. Friedland, M.D., questions the safety of eating farmed fish in the June issue of
the Journal of Alzheimer’s Disease, adding a new worry to concerns about the nation’s
food supply. Friedland and his co-authors suggest farmed fish could transmit Creutzfeldt
Jakob disease--commonly known as mad cow disease--if they are fed byproducts rendered from
cows. The scientists urge government regulators to ban feeding cow meat or bone meal to
fish until the safety of this common practice can be confirmed. “We have not proven
that it’s possible for fish to transmit the disease to humans. Still, we believe that
out of reasonable caution for public health, the practice of feeding rendered cows to fish
should be prohibited,” Friedland said. “Fish do very well in the seas without
eating cows,” he added.
Disclosing your feelings may help
the course of rheumatoid arthritis
The health and physiological effects of an intervention which facilitates the opening of
feelings are described in a paper published in the current issue of Psychotherapy and
Psychosomatics. The efficacy of emotional disclosure in alleviating psychological and
physical stress has been well documented in controlled laboratory studies. A next step is
to evaluate its clinical utility in 'real world' settings. A group of Dutch investigators
adapted the emotional disclosure intervention for use in home-based settings by
stimulating the suggested effective ingredients of cognitive-emotional processing, and
evaluated its psychological and clinical effectiveness. Reviews indicated the need to
examine the physiological changes brought about by emotional disclosure, which may be
particularly relevant in immune-mediated diseases. This study was the first to examine
neuroendocrine and immune changes after emotional disclosure in patients with rheumatoid
arthritis. Sixty-eight patients were randomly assigned to four weekly oral emotional
disclosure or time management sessions.
Roux-en-Y weight loss surgery
raises kidney stone risk
The most popular type of gastric bypass surgery appears to nearly double the chance that a
patient will develop kidney stones, despite earlier assumptions that it would not, Johns
Hopkins doctors report in a new study. The overall risk, however, remains fairly small at
about 8 percent. As rates of morbid obesity have climbed in recent years, so has the
popularity of various weight-loss operations, with more than 200,000 patients expected to
have one of these procedures this year. The most common type of weight loss, or bariatric,
surgery, called Roux-en-Y in a nod to the Y-shape of the surgical connections that go
around part of the bowel, accomplishes weight loss by decreasing the size of the stomach
and allowing food to bypass part of the small intestine. While other bariatric procedures
have been shown to decrease calcium absorption and increase the risk of kidney stones,
doctors have long assumed that the Roux-en-Y procedure did not. To test the assumption,
researchers led by Brian Matlaga, M.D., assistant professor of urology at the Johns
Hopkins University School of Medicine and director of stone diseases and ambulatory care
at Hopkins' James Buchanan Brady Urological Institute, used an insurance claims database
to identify 4,639 patients who had undergone Roux-en-Y surgery between 2002 and 2006. The
researchers identified a second set of 4,639 patients who had similar characteristics—including
age, gender, and body mass indices that indicate obesity—but not the surgery. Using
medical information encoded in the database for both patient populations, the researchers
looked to see which patients were either diagnosed with kidney stones or had treatment for
this condition. Their results showed that while only 8 percent of the Roux-en-Y patients
developed kidney stones, they were nearly twice as likely to get this condition as the
patients with similar characteristics who didn't have weight loss surgery. The researchers
published these findings in the June Journal of Urology. "Our study is not an
indictment of bariatric surgery—the benefits of this surgery are well known,"
says Matlaga. "Rather, we'd like to help physicians understand that their bariatric
patients could be at risk for kidney stones, a condition that could be avoidable with
proper preventative care."
Study supports validity of test
that indicates widespread unconscious bias
In the decade since the Implicit Association Test was introduced, its most surprising and
controversial finding is its indication that about 70 percent of those who took a version
of the test that measures racial attitudes have an unconscious, or implicit, preference
for white people compared to blacks. This contrasts with figures generally under 20
percent for self report, or survey, measures of race bias. A new study published this week
validates those findings, showing that the Implicit Association Test, a psychological
tool, has validity in predicting behavior and, in particular, that it has significantly
greater validity than self-reports in the socially sensitive topics of race, gender,
ethnicity, sexual orientation and age. The research, published in the Journal of
Personality and Social Psychology, is an overview and analysis of 122 published and
unpublished reports of 184 different research studies. In this analysis, 85 percent of the
studies also included self-reporting measures of the type generally used in surveys. This
allowed the researchers, headed by University of Washington psychology Professor Anthony
Greenwald, to compare the test's success in predicting social behavior and judgment with
the success of self-reports.
'Life force' linked to body's
ability to withstand stress
Our ability to withstand stress-related, inflammatory diseases may be associated, not just
with our race and sex, but with our personality as well, according to a study published in
the July issue of the journal Brain, Behavior and Immunity. Especially in aging women, low
levels of the personality trait extraversion may signal that blood levels of a key
inflammatory molecule have crossed over a threshold linked to a doubling of risk of death
within five years. An emerging area of medical science examines the mind-body connection,
and how personality and stress contribute to disease in the aging body. Long-term exposure
to hormones released by the brains of people under stress, for instance, takes a toll on
organs. Like any injury, this brings a reaction from the body's immune system, including
the release of immune chemicals that trigger inflammation in an attempt to begin the
healing process. The same process goes too far as part of diseases from rheumatoid
arthritis to Alzheimer's disease to atherosclerosis, where inflammation contributes to
clogged arteries, heart attacks and strokes. The current study found that that extroverts,
and in particular those high "dispositional activity" or engagement in life,
have dramatically lower levels of the inflammatory chemical interleukin 6 (IL-6). Swiss
psychiatrist Carl Jung defined extroverts as focused on the world around them and most
happy when active and surrounded by people. Introverts looked inward and were shy. The
definitions of extraversion and other personality traits were refined by American
psychologist Gordon Allport beginning in the 1930s. He reviewed all adjectives in the
dictionary used to describe personality, and attempted to group them into clusters. Over
the next several decades, researchers statistically analyzed these dictionary terms and
discovered that they tended to cluster into five general dimensions: extraversion vs.
introversion, emotional stability vs. neuroticism, openness vs. closed-minded, agreeable
vs. hostile, and conscientiousness vs. unreliability. These dimensions, known as the
"Five Factor Model" of personality, served to organize hundreds of specific
traits like "activity" for psychologists, similar to the way the Periodic Table
organizes elements for physicists.
Wrong type of help from parents
could worsen child's OCD
For most parents, soothing a child's anxiety is just part of the job. But for a parent
whose child has obsessive-compulsive disorder, soothing anxiety and helping with behaviors
linked to the disease could lead to more severe symptoms, University of Florida
researchers say. Often, parents of children with OCD will help their children complete
rituals related to their obsessions and compulsions, such as excessive bathing or checking
things like door locks, according to findings recently published in the Journal of
Consulting and Clinical Psychology. These accommodations can be anything that makes the
symptoms of OCD less impairing, from reassuring a child that his hands are clean and his
baby brother is OK to even doing his homework for him or buying objects that make the
child feel safe. "Parents do that because that is what a parent whose child doesn't
have OCD would do," said Lisa Merlo, Ph.D., a UF assistant professor of psychiatry
and the lead author of the study. "If your child is upset, you try to comfort them.
But what we know is, for patients with OCD, if they get an accommodation, that reinforces
the OCD to them.
Structures from the human immune
system's oldest branch shed light on a range of diseases
How molecules of the oldest branch of the human immune system have interconnected has
remained a mystery. Now, two new structures, both involving a central component of an
enzyme important to the complement system of the immune response, reveal how this system
fights invading microbes while avoiding problems of the body attacking itself. The
structures may pave the way to more efficient therapeutics for such complement-mediated
diseases as age-related macular degeneration, rheumatoid arthritis, or systemic lupus
erythematosus, as well as give insight into the pathogenesis of other immune and
inflammatory diseases. The complement system, an evolutionarily old arm of the immune
system, comprises a network of proteins that "complement" the work of antibodies
in destroying foreign invaders. They serve as a rapid defense mechanism in most species,
from primitive sponges to humans. When complement proteins are triggered into action by a
microbe, the proteins ultimately form a complex enzyme called C3 convertase, initiating a
cascade of immune and inflammatory reactions. In order to avoid self-attack, regulatory
proteins such as factor H bind with C3b, a central component of C3, to help the immune
system recognize the body's own tissue and keep complement in check. Researchers at the
University of Pennsylvania School of Medicine, in collaboration with colleagues at Utrecht
University in the Netherlands, have determined the structure of C3 convertase and of the
C3b fragment in complex with factor H. The work appears this month in two companion papers
in Nature Immunology.
Jumping Genes Discovery “Challenges
Current Assumptions,” Say Penn Researchers
Jumping genes do most of their jumping, not during the development of sperm and egg cells,
but during the development of the embryo itself. The research, published this month in
Genes and Development, “challenges standard assumptions on the timing of when mobile
DNA, so-called jumping genes, insert into the human genome,” says senior author Haig
H. Kazazian Jr., MD, Seymour Gray Professor of Molecular Medicine in Genetics at the
University of Pennsylvania School of Medicine.
Europeans target better pesticide
protection
With the annual spread of some 80 000 tonnes of pesticides, farmers are bound to get hit.
However, the context for pesticide spraying has changed considerably over the years, and
Europe has outlined new requirements related to the safety of operators, the general
public, and the environment.In 2005 alone, a total of 800 000 French farmers were exposed
to pesticides. French public research institute Cemagref's Technologies for Farm-Equipment
Safety and Performance Research unit is working to gain knowledge on the exposure of
operators to phytosanitary products. The latest project is building on a 2006 experimental
study that centred on apple tree orchards needing some 30 phytosanitary treatments every
year. The main objectives of the study were to obtain data on the phytosanitary exposure
and contamination of operators, and to enhance the performance of protection cabs used
during the spraying process. For this study, Sonia Grimbuhler, the project manager, and
her team evaluated 250 apple farmers on their use of pesticides, and assessed their
perception of the risks involved. According to a number of typologies already identified,
Ms Grimbuhler established scenarios by considering the most common practices and those
resulting in the highest number of contaminations. The researchers were innovative in
their approach in that they took measurements that were as physically close as possible to
the operator's actual exposure to products: through contact and inhalation.
SSRIs Prescribed for Autistic
Children Make Them Worse
Despite the fact the U.S. Food and Drug Administration (FDA) has not approved any
prescription medications to treat the symptoms of autism and related disorders, drugs are
frequently -- and increasingly -- being given to autistic children, according to a study
in the June issue of Archives of General Psychiatry. An especially popular medication for
autistic kids is the antidepressant citalopram, sold under the brand name Celexa, a
selective serotonin reuptake inhibitor (SSRI), which interferes with the way the brain
regulates the neurotransmitter serotonin.
|
|
|
|