News 17 march 2009
Obese women play cancer roulette
Obese women may be putting themselves at
greater risk of breast cancer by not undergoing regular screening. According to new
research by Dr. Nisa Maruthur and her team from The John Hopkins University School of
Medicine in Baltimore, USA, seriously obese women are significantly less likely to say
they have undergone a recent mammography than normal weight women, especially if they are
white. Maruthur’s findings are published online this week in Springer’s Journal
of General Internal Medicine.Breast cancer is the second leading cause of cancer death
among women in the US. Mammography screening has been proven to reduce the number of
deaths from breast cancer; current guidelines recommend that women over the age of 40
undergo a mammography every couple of years. Obesity is also an important risk factor for
both the development of, and death from, postmenopausal breast cancer.
Master Molecular Switch May Prevent
the Spread of Cancer Cells to Distant Sites in the Body, According to Penn Study
Researchers at the University of
Pennsylvania School of Medicine have identified a master switch that might prevent cancer
cells from metastasizing from a primary tumor to other organs. The switch is a protein
that, when in the “on” position, maintains the normal character of cells that
line the surface of organs and body cavities. These epithelial cells are the type of cell
from which most solid tumors arise. However, when the switch is turned “off” or
absent, epithelial cells acquire characteristics of another cell type, called mesenchymal
cells, and gain the ability to migrate and move away from the primary tumor. The
researchers report their findings in this month’s issue of Molecular
Cell.Understanding how this switch works may one day lead to a drug that controls cancer
cell metastasis and tissue fibrosis. This change in cell motility is called the epithelial
to mesenchymal transition, or EMT, and is an important process during the development of
embryos. But when the transition is aberrantly reactivated in adults it can have dire
physiological consequences, leading to cancer metastasis as well as other disease
processes such as tissue fibrosis. Fibrotic tissue is a hallmark of organ failure, as in
liver cirrhosis or kidney failure.
Synthesizing the most natural of
all skin creams
Even after nine months soaking in the womb,
a newborn’s skin is smooth – unlike an adult’s in the bath. While occupying
a watery, warm environment, the newborn manages to develop a skin fully equipped to
protect it in a cold, dry and bacteria-infected world. A protective cream called Vernix
caseosa (VC), which covers the fetus and the newborn, aids in the growth of skin both
before and after birth. VC provides ‘waterproofing’ in utero, allowing skin to
grow in wet conditions, while after birth it hydrates and cleanses, even healing when
applied to ulcers. Prof. Joke Bouwstra, a specialist in the skin barrier and its synthesis
at Leiden University, and her colleague Robert Rißmann set out to study VC in detail and
has produced a synthetic version of this natural buttery ointment which shows the same
structure and unique properties. As well as helping pre-term babies develop essential
protection against temperature changes, dehydration and infection, artificial VC could
also benefit sufferers of skin disease. Like most moisturising creams, VC is mostly water.
Its outstanding properties come from the addition of just 10% each of lipid molecules and
dead skin cells (corneocytes), so the exact composition of the mixture is important. For
the lipids, X-ray diffraction measurements at the Dutch/Flemish DUBBLE beamline at the
ESRF (European Synchrotron Radiation Facility) allowed the Leiden researchers to find the
proportions of the various forms in the cream, even distinguishing between complex
molecules differing in chain length.
Researchers clone key sperm-binding
proteins
New treatments for infertility could be
closer to reality, thanks to a discovery from scientists at the Université de Montréal
and Maisonneuve-Rosemont Hospital Research Centre. According to a study published in the
journal Molecular Human Reproduction, the researchers have become the first to clone,
produce and purify a protein important for sperm maturation, termed Binder of Sperm (BSP),
which may have implications for both fertility treatments and new methods of male
contraception."We have previously isolated and characterized BSPs from many species,
such as bulls and boars," says Dr. Puttaswamy Manjunath, senior author and a
professor in the departments of medicine and of biochemistry at the Université de
Montréal and a member of the Maisonneuve-Rosemont Hospital Research Centre. "We know
from these studies that if this protein is missing or defective in these species,
fertility is compromised. We believe that BSP is equally important in humans."
Studies show that nice guys finish
first in business world
When it comes to leading a team tasked with
developing new products and bringing them to market, new research from North Carolina
State University shows that being nice and playing well with others gives you a very real
competitive advantage. One new study shows that project managers can get much better
performance from their team when they treat team members with honesty, kindness and
respect. A second study shows that product development teams can reap significant quality
and cost benefits from socializing with people who work for their suppliers. The first
study, co-authored by NC State's Dr. Jon Bohlmann, focused on cross-functional product
development teams, which bring together engineers, researchers and business personnel. The
diverse backgrounds of the team members means there is a focus on finance and marketing,
as well as design and functionality, from the beginning of the product-development
process. But that diversity also makes effective communication essential, in order to
ensure that team members are collaborating rather than working at cross-purposes. The
Bohlmann study finds that "interactional fairness perception" affects
"cross-functional communication." In other words, Bohlmann explains, "If
you think you are being treated well, you are going to work well with others on your
team." Bohlmann, an associate professor of marketing at NC State, says that the study
evaluated whether team members felt they were being well treated by their project leader.
This evaluation included questions as to whether team members felt their leader was
honest, kind and considered the viewpoints of team members. Bohlmann says the results of
the study show that if a team's leader was perceived as "basically being a nice
guy," then "team members showed a significant increase in commitment to the
team's success and to the project they were working on." This increase in commitment
is important, Bohlmann explains, because it leads to enhanced performance in meeting team
goals.
New strategy to weaken traumatic
memories
Imagine that you have been in combat and
that you have watched your closest friend die in front of you. The memory of that event
may stay with you, troubling you for the rest of your life. Posttraumatic stress disorder
(PTSD) is among the most common and disabling psychiatric casualties of combat and other
extremely stressful situations. People suffering from PTSD often suffer from vivid
intrusive memories of their traumas. Current medications are often ineffective in
controlling these symptoms and so novel treatments are needed urgently. In the February
1st issue of Biological Psychiatry, published by Elsevier, a group of basic scientists
shed new light on the biology of stress effects upon memory formation. In so doing, they
suggest new approaches to the treatment of the distress related to traumatic memories.
Their work is based on the study of a drug, RU38486, that blocks the effects of the stress
hormone cortisol. Using an animal model of traumatic memory, investigators at the Mount
Sinai School of Medicine show that treatment with RU38486 selectively reduces
stress-related memories, leaving other memories unchanged. They also found that the
effectiveness of the treatment is a function of the intensity of the initial
"trauma." Although this particular study was performed in rats, their findings
help to set the stage for trials in humans. Cristina Alberini, Ph.D., corresponding author
on this article, explains how their findings will translate into developing clinical
parameters: "First, the drug should be administered shortly before or after recalling
the memory of the traumatic event. Second, one or two treatments are sufficient to
maximally disrupt the memory. Third, the effect is long lasting and selective for the
recalled memory. Finally, the time elapsing between the traumatic experience and the
treatment seems to be an important parameter for obtaining the most efficacious
treatment."
Study tracks increasing use of CT
on pregnant women
Researchers have found that over a 10-year
period radiologic exams on pregnant women have more than doubled, according to a study
published in the online edition of Radiology. "Imaging utilization has not been
previously studied in the pregnant population," said Elizabeth Lazarus, M.D.,
assistant professor of diagnostic imaging at the Warren Alpert School of Medicine at Brown
University and a radiologist at Rhode Island Hospital in Providence, R.I. "This
population may be vulnerable to the adverse effects of radiation." Dr. Lazarus and
colleagues conducted a retrospective review of nuclear medicine, CT, fluoroscopy and
plain-film x-ray imaging examinations performed at Rhode Island Hospital and Women and
Infants' Hospital from 1997 through 2006 to determine how often these imaging exams were
performed on pregnant women and the estimated radiation dose to the fetus. Data were then
compared to the number of infant deliveries per year for that same time period. The
researchers found that from 1997 to 2006, the total number of imaging studies performed on
pregnant women at their institution increased by 10.1 percent per year, but the number of
CT exams increased by 25.3 percent per year. CT delivers a higher amount of radiation than
many other radiologic procedures. CT exams are not routinely ordered for pregnant women,
but may be necessary to detect suspected life-threatening conditions such as bleeding in
the brain, blood clots in the lungs or appendicitis. Since CT exposes the developing fetus
to radiation, concerns are often raised regarding overuse. The majority of CT examinations
(approximately 75 percent) analyzed in the study were performed in areas of the mother's
body separate from the uterus, so the fetus was not exposed to any direct radiation.
Still, low levels of radiation have been shown to carry a small risk of harm to a
developing fetus. "Women should know that imaging is generally safe during pregnancy
and is often used to detect potentially life-threatening problems," Dr. Lazarus said.
"However, this study should raise awareness about imaging trends in pregnant patients
and help us continue in our efforts to minimize radiation exposure," Dr. Lazarus
said.
Preventium is 'where the prevention
of breast and prostate cancer begins'
Dr. Ercole Cavalieri and Dr. Eleanor Rogen
of the University of Nebraska Medical Center, Eppley Institute for Research in Cancer,
located in Omaha, Nebraska, have identified the triggering mechanism by which breast and
prostate cancer cells begin. Preventium™ http://www.preventium.org is a recently
developed dietary supplement that promises to reduce people's risk for breast and prostate
cancer. Ercole Cavalieri, D.Sc. and research collaborator Eleanor Rogen, Ph.D. say:
"We have found the first step that starts a cell down the road to becoming a cancer
cell. By blocking this first step from happening, we feel we can stop the development of
breast and prostate cancer." The researchers have discovered that certain estrogen
derivates (metabolites) can react with deoxyribonucleic acid (DNA) to cause damage that
may initiate the start of breast and prostate cancer. Estrogen can initiate cancer when
natural protective mechanisms do not function properly in the body, which then allows
estrogen metabolites to react with DNA. Since both men and women have naturally occurring
estrogen, the triggering mechanism for breast and prostate cancer is identical. This
research has been funded in part by nearly $40 million in direct funding from the National
Cancer Institute and the U.S. Defense Department.
UH sociologist has different
perspective on obesity 'epidemic'
Headlines tell us the nation is getting
fatter, and that obesity has become an epidemic. But there is more to the story, according
to one University of Houston sociologist. While she acknowledges that there has been a
shift in body weight over the years, assistant sociology professor Samantha Kwan looks at
obesity from a different perspective. The term obesity was constructed by the medical
community, Kwan says. And the use of the Body Mass Index, which measures obesity, as the
main factor to define obesity, has resulted in the media greatly overstating the rise of
the condition. "This epidemic has been constructed to the benefit of the medical
industry that has in part medicalized the treatment of obesity over the years," Kwan
says. "While there may be a rise in 'obesity,' the BMI is not always accurate. Some
scholars describe this epidemic more as a moral panic. While there may be some truths to
rising rates, they have been overstated." Kwan, who has been studying gender and body
image since 2001, examines how cultural beauty messages about fat interact with other
cultural messages about fat, such as health discourses. This is summarized in her article
"Framing the Fat Body: Contested Meanings between Government, Activists and
Industry," published in February's Sociological Inquiry. "I am trying to get
students and audiences to understand that there are competing cultural meanings about the
fat body," Kwan says. "Fat does not, in itself, signify unhealthy and
unattractive. These are cultural constructions. We as a society say what it means to be
fat, and right now cultural discourses say it's ugly and unhealthy to be fat. … It's
also assumed that the body is a reflection of the psyche, including one's moral
fiber." Kwan has found that women's self-esteem is more closely tied to weight than
men's.
First sister study results
reinforce the importance of healthy living
Women who maintain a healthy weight and who
have lower perceived stress may be less likely to have chromosome changes associated with
aging than obese and stressed women, according to a pilot study that was part of the
Sister Study. The long-term Sister Study is looking at the environmental and genetic
characteristics of women whose sister had breast cancer to identify factors associated
with developing breast cancer. This early pilot used baseline questionnaires and samples
provided by participants when they joined the Sister Study. Two recent papers published in
Cancer Epidemiology Biomarkers and Prevention looked at the length of telomeres, or the
repeating DNA sequences that cap the ends of a person's chromosomes. Telomere length is
one of the many measures being looked at in the Sister Study. Telomeres protect the ends
of chromosomes and buffer them against the loss of important genes during cell
replication. Over the course of an individual's lifetime, telomeres shorten, gradually
becoming so short that they can trigger cell death. The papers show that factors such as
obesity and perceived stress may shorten telomeres and accelerate the aging process.
"Together these two studies reinforce the need to start a healthy lifestyle early and
maintain it," said Linda Birnbaum, Ph.D., the director of the National Institute of
Environmental Health Sciences (NIEHS), part of the National Institutes of Health. The
researchers who published these papers are from the NIEHS which sponsors the Sister Study.
The papers are the first findings coming out of the Sister Study. The Sister Study is just
completing its enrollment of 50,000 women aged 35-74 to prospectively study risk factors
for breast cancer. "We anticipate a wealth of information to come out of the Sister
Study," said Dale Sandler, Ph.D., chief of the Epidemiology Branch at NIEHS and
principal investigator of the Sister Study. "Not only do we hope to find out more
about the environmental and genetic factors that might lead to breast cancer, we also want
to learn more about how factors such as stress, diet and exercise might impact cancer and
other disease risks." One of the studies published this week found that women who
were obese for a long time had reduced telomere length. The researchers looked at the
relationship between various measures of current and past body size and telomere length in
647 women enrolled in the Sister Study. They found that women who had an overweight or
obese body mass index (BMI) before or during their 30s, and maintained that status since
those years, had shorter telomeres than those who became overweight or obese after their
30s. "This suggests that duration of obesity may be more important than weight change
per se, although other measures of overweight and obesity were also important," said
Sangmi Kim, Ph.D., epidemiologist and lead author on the paper. "Our results support
the hypothesis that obesity accelerates the aging process," said Kim.
Search for blood pressure secrets
reveals a surprising new syndrome
Yale researchers investigating the genetic
causes of blood pressure variation have identified a previously undescribed syndrome
associated with seizures, a lack of coordination, developmental delay and hearing loss.
The findings, published this week in Proceedings of the National Academy of Sciences,
illustrate the power of genetic studies not only to find causes of chronic ailments, but
also to identify a common cause in a seemingly unrelated set of symptoms in different
parts of the body. "Our ability to unequivocally and rapidly define new syndromes and
their underlying disease genes has progressed dramatically in recent years," said
Richard Lifton, chair of the Department of Genetics at the Yale School of Medicine and
senior author of the study. "A study like this would have taken years in the past,
but was accomplished in a few weeks by a single fellow in the lab." The discovery of
the new syndrome was made by Ute Scholl, a post-doctoral fellow in Lifton's lab, who was
conducting a genetic analysis of 600 patients for causes of salt-handling defects of the
kidney, which lead to high or low blood pressure. She identified a group of five patients
from four families in Afghanistan, Turkey, Great Britain and Canada who had, in addition
to a salt-handling defect, diverse neurologic problems. The similar clinical features of
these patients suggested that all might be caused by a single defect, and in a matter of
weeks she found that all five had inherited mutations in the gene KCNJ10, a potassium
channel that is expressed in the brain, inner ear and kidney.
Emotions can help predict future
eating disorders
A PhD thesis at the University of the
Basque Country (UPV/EHU) has analysed the role played by a number of emotional variables,
such as the way in which negative emotions are controlled or attitudes to emotional
expression, and to use these variables as tools to predict the possibility of suffering an
eating disorder. The author of the thesis, Ms. Aitziber Pascual Jimeno, presented her work
under the title, Emotions and emotional control in eating disorders: predictor role and
emotional profiles. Ms Pascual is a graduate in Psychology and carried out her thesis
under Ms Itziar Etxebarria Bilbao and Ms María Soledad Cruz Sáez, from the Department of
Basic Psychological Processes and their Development at the Faculty of Psychology of the
UPV/EHU. She is currently working as a lecturer at the University. In order to undertake
the study, 433 women took part; 143 of these suffered from some kind of eating disorder
and 145 in risk of contracting one. The results of the study show that, in general, the
majority of the variables put forward can be used as predictive of suffering an eating
disorder. The variables which, above all, alert to greater risk of developing an eating
disorder are when the emotional state of the person is excessively influenced by diet,
weight and body shape, when self-esteem is low, and when, in anxiety situations, emotions
are not expressed and the person tends to act in an impulsive manner. These results have
important implications, above all when drawing up prevention programmes for eating
disorders. With the data obtained, it can be said that many of the emotional variables
dealt with in Ms Pascual’s work should be taken into account when drawing up these
prevention programmes.
