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Week 41
Nanoparticle-based battlefield pain
treatment moves step closer
University of Michigan scientists have developed a combination drug that promises a safer,
more precise way for medics and fellow soldiers in battle situations to give a fallen
soldier both morphine and a drug that limits morphine’s dangerous side effects. They
use nanotechnology to devise ultra-small polymer particles capable of carrying the drugs
into the body. The development of the combination drug makes possible a precise feedback
system that can safely regulate release of the drugs aboard the nanoparticles.
Use It or Lose It? Study Suggests
the Brain Can Remember a “Forgotten” Language
Many of us learn a foreign language when we are young, but in some cases, exposure to that
language is brief and we never get to hear or practice it subsequently. Our subjective
impression is often that the neglected language completely fades away from our memory. But
does “use it or lose it” apply to foreign languages? Although it may seem we
have absolutely no memory of the neglected language, new research suggests this
“forgotten” language may be more deeply engraved in our minds than we realize.
Psychologists Jeffrey Bowers, Sven L. Mattys, and Suzanne Gage from the University of
Bristol recruited volunteers who were native English speakers but who had learned either
Hindi or Zulu as children when living abroad. The researchers focused on Hindi and Zulu
because these languages contain certain phonemes that are difficult for native English
speakers to recognize. A phoneme is the smallest sound in a language—a group of
phonemes forms a word. The scientists asked the volunteers to complete a background
vocabulary test to see if they remembered any words from the neglected language. They then
trained the participants to distinguish between pairs of phonemes that started Hindi or
Zulu words.
New Paper from Internists Calls for
Increased Role for FDA
A new policy paper that calls for broader authority and increased funding for the Food and
Drug Administration (FDA) was released today by the American College of Physicians (ACP).
Improving FDA Regulation of Prescription Drugs offers a half-dozen recommendations about
how to improve the agency’s ability to approve and monitor new drugs. The paper notes
that the FDA has been chronically underfunded, has limited regulatory authority, and
insufficient organizational structure to effectively undertake the complex task of
regulating the safety and effectiveness of new and approved drugs. This regulating
includes reviewing proposals for conducting clinical drug trials, evaluating drug
applications and proposed drug labeling, and monitoring drugs once they are approved and
marketed. “The FDA is critical in assuring the prescription drugs available in this
country are safe and effective,” said Joseph W. Stubbs, MD, FACP, president of ACP.
“Unfortunately they have not historically been given the support and structure
necessary to be optimally effective.”
New study shows mobile infants have
established neural pathways to see looming danger
Do infants only start to crawl once they are physically able to see danger coming? Or is
it that because they are more mobile, they develop the ability to sense looming danger?
According to Ruud van der Weel and Audrey van der Meer, from the Norwegian University of
Science and Technology in Trondheim, infants’ ability to see whether an object is
approaching on a direct collision course, and when it is likely to collide, develops
around the time they become more mobile. Their findings1 have just been published online
in the Springer journal Naturwissenschaften. An approaching object on a collision course
projects an expanding image on the retina, providing information that the object is
approaching and how imminent the danger is. Looming stimuli create waves of neural
activity in the visual cortex in adults. The authors investigated how, and where, the
infant brain extracts and processes information about imminent collision.
Vitamin D deficiency in younger
women is associated with increased risk of high blood pressure in mid-life
Vitamin D deficiency in premenopausal women may increase the risk of developing systolic
hypertension 15 years later, according to research reported at the American Heart
Association’s 63rd High Blood Pressure Research Conference. Researchers examined
women enrolled in the Michigan Bone Health and Metabolism Study and analyzed data from 559
Caucasian women living in Tecumseh, Mich. The ongoing study began in 1992 when the women
were 24 to 44 years old with an average age of 38 years. Researchers took blood pressure
readings annually throughout the study. They measured vitamin D blood levels once in 1993,
and then compared their systolic blood pressure measurements taken in 2007. Premenopausal
women who had vitamin D deficiency in 1993 had three times the risk of developing systolic
hypertension 15 years later compared to those who had normal levels of vitamin D,
researchers said. “This study differs from others because we are looking over the
course of 15 years, a longer follow-up than many studies,” said Flojaune C. Griffin,
M.P.H., co-investigator of the study and a doctoral candidate in epidemiology at the
University of Michigan School of Public Health in Ann Arbor, Mich. “Our results
indicate that early vitamin D deficiency may increase the long-term risk of high blood
pressure in women at mid-life.”
Marshall research shows safe
dosages of common pain reliever may help prevent muscle loss and other conditions related
to aging
Recent studies conducted by Dr. Eric Blough and his colleagues at Marshall University have
shown that use of the common pain reliever acetaminophen may help prevent age-associated
muscle loss and other conditions. Their study examined how acetaminophen may affect the
regulation of protein kinase B (Akt), an enzyme known to play an important role in
regulation of cellular survival, proliferation and metabolism. The researchers’ data
indicates that aging skeletal muscles experience a decrease in the proper functioning of
the enzyme and that acetaminophen intervention in aged animals could be used to restore
Akt activity to a level comparable to that seen in young animals. In turn, this
improvement in Akt activity was associated with improvements in muscle cell size and
decreased muscle cell death. “Using a model that closely mimics many of the
age-associated physiological changes observed in humans, we were able to demonstrate that
chronic acetaminophen treatment in a recommended dosage is not only safe but might be
beneficial for the treatment of the muscle dysfunction many people experience as they get
older,” said Blough, an associate professor in the university’s Department of
Biological Sciences. The lab’s work, which was published in the July 29 issue of the
international research journal PLoS One, is the first study to show that acetaminophen
ingestion, at least in animals, can be safely used for the treatment of age-related muscle
loss. This finding could have far-reaching implications, given the fact that people age 65
and older make up the fastest-growing segment of the U.S. population.
Caltech scientists get detailed
glimpse of chemoreceptor architecture in bacterial cells
Using state-of-the-art electron microscopy techniques, a team led by researchers from
Caltech has for the first time visualized and described the precise arrangement of
chemoreceptors—the receptors that sense and respond to chemical stimuli—in
bacteria. In addition, they have found that this specific architecture is the same
throughout a wide variety of bacterial species, which means that this is a stable,
universal structure that has been conserved over evolutionary time. Their research, which
was published this week in the online early edition of the Proceedings of the National
Academy of Sciences (PNAS), may help scientists better understand the complex signaling
pathways that are at the core of many biological processes. Bacteria swim using flagella
to propel themselves. But it's not as simple as that, explains Grant Jensen, associate
professor of biology at Caltech and an investigator with the Howard Hughes Medical
Institute (HHMI), who led the team. After all, they need to decide where to swim.
"They tend to swim toward a favorable environment, and away from a harsh
environment," Jensen says. How do they know which is which? Enter the chemoreceptors,
tiny protein molecules found at the front of the bacterium, near the flagella. "It's
like a protein antenna that protrudes from the bacterial cell body, through the membrane,
and out onto the surface," says Jensen. "It binds to nutrients and other
chemical stimuli." While swimming in a single direction, a bacterium such as
Escherichia coli may encounter some nutrients, which then bind to the chemoreceptors.
"This transmits a signal to the inside of the cell saying that things are good,"
says Jensen. "So the bacterium will keep swimming in the same direction. But if there
are no good nutrients, the cell will do something called 'tumbling,' in which it stops and
randomly flips over in the fluid, then starts swimming again in a random direction in a
search for better conditions."
How mitochondrial gene defects
impair respiration, other major life functions
Researchers are delving into abnormal gene function in mitochondria, structures within
cells that power our lives. Mitochondria are the place where energy is generated from the
most basic molecules of food. Because this function is essential to life, defects in
mitochondria may affect a wide range of organ systems in humans and animals. Some names of
mitochondrial disorders are Leigh's disease, MELAS syndrome and complex I deficiency.
These are often severe and progressive conditions that attack brain, muscles and numerous
other parts of the body. Mitochondrial diseases are individually very rare, but because
hundreds of them exist, they collectively have a large impact, affecting at least 1 in
5,000 people, and perhaps more, who often remain undiagnosed. In addition to a wide array
of diseases originating in the mitochondria itself, malfunctioning mitochondria also
contribute to complex disorders like Parkinson's disease, Alzheimer's disease, epilepsy
and diabetes, among others. For such crucial biological actors, much remains unknown about
exactly how mitochondria function. A new study, published Aug. 12 in the online journal
PLoS One, sheds light on mitochondrial biology. Using genetic engineering, researchers
interrupted the activity of individual genes directly involved in the production of energy
within mitochondria. "If we knock down the function of specific system components,
what happens?" said study leader Marni J. Falk, M.D., who directs the
Mitochondrial-Genetics Disease Clinic at The Children's Hospital of Philadelphia.
"Our ultimate goal is to translate the knowledge into targeted therapies, that is,
effective ways to intervene. But first we need to understand the underlying disease
mechanisms." Falk's team made use of a simple model organism often studied in
biology, Caenorhabditis elegans, which is a small worm called a nematode. Because
mitochondria arose very early in evolution and play such fundamental roles in
multicellular organisms, learning the details of how mitochondria function in C. elegans
provides useful clues to understanding their function in humans. Falk and colleagues
studied a biological pathway that occurs within mitochondria, called the respiratory
chain. They specifically focused on the largest component of that chain, complex I, which
contains 45 subunits and is the most common culprit in human mitochondrial disease.
Shedding light on cancer cells
Scientists label cells with coloured or glowing chemicals to observe how basic cellular
activities differ between healthy and cancerous cells. Existing techniques for labelling
cells are either too slow or too toxic to perform on live cells. Now, a study reviewed by
Philip Dawson, a member of Faculty of 1000 Biology and leading authority in chemistry and
cell biology, describes a novel labelling technique that uses a chemical reaction to make
live cancer cells light up quickly and safely. Researchers at Massachusetts General
Hospital developed a two-step process to specifically tag cancer cells. First, chemically
modified antibodies home in on cancer cells. Then a chemical reaction called cycloaddition
transfers a dye onto the antibody making the cancer cells glow when viewed through a
microscope. The novel cycloaddition reaction is fast, very specific, and requires minimal
manipulation of the cells. Dawson comments that, in combining antibody binding with the
cycloaddition, "low signal-to-noise ratios are achieved". This new labelling
technique could be used to track the location and activity of anti-cancer drugs, the
location of cancer-specific proteins within the cell, or to visualize cancer cells inside
a living organism. Dawson concludes that cycloaddition will allow scientists to observe
live cancer cells in the body, leading to a better understanding of cancer's basic
processes.
Study finds nontuberculous
mycobacteria lung disease on the rise in the United States
Nontuberculous mycobacteria (NTM) are environmental organisms found in both water and soil
that can cause severe pulmonary (lung) disease in humans. Pulmonary NTM is on the rise in
the United States, according to a large study of people hospitalized with the condition. A
research team led by epidemiologists from the National Institute of Allergy and Infectious
Diseases, part of the National Institutes of Health, analyzed hospital discharge records
of patients in 11 states whose combined total population represents 42 percent of the
country. They reviewed database records spanning 1998 to 2005, and identified more than
16,475 hospitalizations associated with pulmonary NTM in people without AIDS. Before the
widespread availability of combination antiretroviral therapy, pulmonary NTM disease was a
common opportunistic infection among people with AIDS infection; in this study, the
researchers limited their analysis to non-AIDS NTM disease. Of the 11 states studied,
Florida, New York and California had 62 percent of the pulmonary NTM hospitalizations. The
scientists chose these states to compare trends by geographic area. They found the annual
prevalence of disease increased significantly among men and women in Florida (3.2 percent
per year for men and 6.5 percent per year for women) and among women in New York (4.6
percent per year). There were no significant changes in California. Whether these
geographic differences in prevalence are a result of exposure to NTM, or increased
concentrations of mycobacterium in certain environments, or both, is not clear. However,
previous studies have found high disease prevalence in the southeastern United States,
particularly along the coastal regions of the Atlantic and Gulf coasts. Study results show
pulmonary NTM has increased in certain geographic areas of the United States, and while
overall prevalence is higher in women, prevalence increases for both sexes in the fifth or
sixth decade of life. Further research is needed to define the prevalence of the disease
in nonhospitalized people in regions throughout the United States and to determine risk
factors for disease susceptibility, including genetic and environmental factors.
Scientists Identify Genetic Cause
of Previously Undefined Primary Immune Deficiency Disease
Researchers at the National Institutes of Health have identified a genetic mutation that
accounts for a perplexing condition found in people with an inherited immunodeficiency.
The disorder, called combined immunodeficiency, is characterized by a constellation of
severe health problems, including persistent bacterial and viral skin infections, severe
eczema, acute allergies and asthma, and cancer. The team that made the discovery was led
by Helen Su, M.D., Ph.D., at the National Institute of Allergy and Infectious Diseases
(NIAID), and included collaborators from NIAID and the National Cancer Institute (NCI).
The research is reported in this week’s New England Journal of Medicine. “NIH
clinicians have cared for people with unusual and difficult-to-treat immune disorders for
decades,” says NIAID Director Anthony S. Fauci, M.D. “This study exemplifies
their commitment to improving the lives of people with these diseases by trying to uncover
the causes of these disorders and thereby better understanding how to treat them.”
University Hospitals Case Medical
Center to test gammaglobulin treatment for Alzheimer's disease
Researchers from the Memory and Cognition Center at University Hospitals Case Medical
Center will begin testing an intriguing new approach to slowing down the progression of
Alzheimer's Disease (AD) using Intravenous Immune Globulin (IGIV), also known as
gammaglobulin. IGIV is traditionally used to treat primary immunodeficiency disorders, but
is not currently approved for treating AD, which is one of the leading causes of dementia
in the elderly. Initial research in experimental models and patients suggests that
immunotherapy targeting beta amyloid (the protein that forms the core of plaques in the
brain) may provide a more effective way to treat AD. Antibodies that bind to beta amyloid
are present in IGIV, which is made from the blood of several thousand healthy adults. One
of the hallmarks of AD pathology is an abundance of beta-amyloid deposits in the brain.
While it is not yet known if beta amyloid plaques cause AD or are a byproduct of the
disease, scientists are interested in finding ways to reduce the toxic effects of beta
amyloid on the brain. Antibodies against beta amyloid may do so by binding to toxic forms
of beta amyloid, thereby neutralizing them and/or promoting their elimination. "We
are investigating whether IGIV, which contains naturally occurring human anti-amyloid
antibodies, will defend the brain of AD patients against the damaging effects of beta
amyloid. If it does, giving IGIV to patients with mild to moderate Alzheimer's may
potentially slow the rate of progression of the disease," says Alan Lerner, M.D.,
principal investigator for the study in Cleveland and director of the Memory and Cognition
Center. "In our initial studies in AD patients, IGIV provided significant cognitive
benefits, improved brain metabolism and reduced beta amyloid levels in the spinal
fluid," says Norman Relkin, M.D., project director and director of the Weill Cornell
Alzheimer's Disease and Memory Disorders Program. In a Phase II trial at Weill Cornell,
Dr. Relkin reported that participants undergoing several months of continuous IGIV therapy
also demonstrated improvement in their activities of daily living. He added, "These
findings, as well as IGIV's long established record of safe use for treating other
diseases, provide a strong rationale for further study in AD patients on a larger
scale."
The EU must allocate fewer emission
allowances and stop making free allocations
EU emissions trading has put a price on something that used to be free – the right to
pollute the atmosphere. But prices are low, allowances are allocated free of charge, and
as a precaution and for fear of harming industry, the EU has set a generous cap on
emissions. – Allocating free allowances creates problematic expectations among
companies; "If we emit a lot today, we’ll be given a large number of emission
allowances tomorrow.” This runs completely counter to the idea of encouraging
emission reductions, says the researcher Markus Wråke.Markus Wråke is a researcher at
IVL Swedish Environmental Research Institute Ltd, and in his doctoral thesis he examines
European energy and climate policy, in particular emissions trading. He believes that the
academic discussion on emissions trading made a relatively deep impression on the European
Commission and the Swedish Government when the revisions of the EU ETS that will apply
from 2013 were drawn up. "It was disappointing that the negotiations between the
Member States and the European Parliament then resulted in a somewhat watered-down
decision. I nevertheless feel that my research is contributing to making the system
better. It is worse that while I and other researchers identified shortcomings in the
trading system early on, back in 2004, no serious changes will be made until 2013.
Do your children push the
boundaries? It may be a sign of future leadership abilities
Children whose parents use a firm parenting style that still allows them to test the rules
and learn from it are more likely to assume leadership roles as adults according to a new
study published in a recent edition of The Leadership Quarterly. Researchers used data
from a long-term Minnesota study of twins. They found that children raised with an
“authoritative” parenting style – where parents set clear limits and
expectations while also being supportive of their children – assumed more leadership
roles at work and in their communities later in life. While these children were also less
likely to engage in serious rule-breaking, children who did engage in serious
rule-breaking were less likely to assume leadership roles. Good parenting may better
prepare children for future leadership roles if the children happen to challenge the
boundaries set out by their parents. This gives the children an opportunity to learn why
the rules are in place and then learn from their parents how to achieve their goals
without breaking the rules. “Some of these early examples of rule-breaking behaviour,
more the modest type, don’t necessarily produce negative outcomes later in life
– that was fairly intriguing,” says Maria Rotundo, a professor at the Rotman
School of Management. “It doesn’t mean all children of authoritative parents are
going to become leaders, but they are more likely to.”
Mayo Clinic Researchers Find Few
Side Effects from Radiation Treatment Given After Prostate Cancer Surgery
The largest single-institution study of its kind has found few complications in prostate
cancer patients treated with radiotherapy after surgery to remove the prostate. Men in
this study received radiotherapy after a prostate-specific antigen (PSA) test following
surgery indicated their cancer had recurred. Researchers say the findings from Mayo
Clinic's campuses in Florida and Minnesota suggest that patients and their physicians
should not overly worry about toxicity and side effects from the treatment, known as
salvage external beam radiotherapy. The study findings will be published in the October
issue of Radiotherapy and Oncology. "There is a general fear of this kind of
radiation treatment on the part of some patients and their physicians, but this study
shows that it not only effectively eradicates the recurrent cancer in a substantial number
of patients, but that there are few serious side effects," says the study's lead
investigator, Jennifer Peterson, M.D., from the Department of Radiation Oncology at Mayo
Clinic in Florida.
Lack of Social Support Tied to
Parental Depression
The latest research from Family Relations shows that parents in low-income environments
are more prone to depression when there is a lack of social support. This is especially
prevalent in rural regions, where mental health and social resources can be deficient.
Social support mechanisms such as community groups, churches, and school or sports-related
activities, can act as a barrier against negative thinking and allow parents who are prone
to depression, in order to make better, more positive choices and engage in healthy
parental practices. The findings support a holistic care plan for families in need,
combining skill-based interventions with social recommendations. These measures may help
to decrease the detrimental effects of economic stress on individual and family
functioning.
Gut worms may protect against
house-dust mite allergy
A study conducted in Vietnam has added further weight to the view that parasitic gut
worms, such as hookworm, could help in the prevention and treatment of asthma and other
allergies. Led by Dr Carsten Flohr, a Clinical Scientist from The University of
Nottingham, and Dr Luc Nguyen Tuyen from the Khanh Hoa Provincial Health Service in
central Vietnam, the study is the largest double-blind placebo controlled clinical trial
to date looking at the potential links between hookworm and other gut worm infections and
allergic conditions such as asthma and eczema. Thanks to improved hygiene practices
parasitic worms have been mostly eradicated among human populations living in developed
countries. However, experts believe that over millions of years of co-evolution worms have
found methods to dampen down host immune responses to prolong their own survival inside
humans. This relationship seems to have become so intertwined that without gut worms or
other parasites, our immune system can become unbalanced, which in turn could contribute
to the development of asthma and other allergies. At the same time, it is important to
remember that gut parasites can cause severe disease and are a major cause of
iron-deficiency anaemia in developing countries.
Precedent for America's move toward
restitution for human rights abuses
A growing global movement to apologize and make restitution to victims of human rights
abuses is now gathering steam in the United States, but it won't be a first for the
country, says the president of The Western History Association."In reviewing the
history of reconciliation in the American West, I've found three examples of government
restitution — where we acknowledge we've participated in human rights abuses and
offered either an apology, restitution, reparation or all three," says Sherry Smith,
associate director of the Clements Center for Southwest Studies at SMU and an SMU history
professor.The state of Montana granted posthumous pardons to Germans and Austrians
convicted and imprisoned under repressive sedition laws during World War I; the U.S.
government paid reparations to the heirs of Japanese Americans relocated to incarceration
camps during World War II; and in a landmark native-lands case, Arizona returned 6,000
acres to the Hualapai tribe in the 1940s and the U.S. government set up the Indian Claims
Commission. "These are tiny steps considering the magnitude of the problem. But they
helped turn the corner of deep injustice," Smith says. "It's never too late to
do the right thing."
U of T led research team uncovers
evolutionary origins of prion disease gene
A University of Toronto-led team has uncovered the evolutionary ancestry of the prion
gene, which may reveal new understandings of how the prion protein causes diseases such as
bovine spongiform encephalopathy (BSE), also known as "mad cow disease."
Diseased prion proteins are responsible for the fatal neurodegenerative Creutzfeldt-Jakob
disease (CJD) in humans, and BSE, scrapie and chronic wasting disease (CWD) in livestock.
Overall, this work holds promise for efforts to reveal the physiological function of
members of the prion protein family and may provide insights into the origins and
underlying constraints of the conformational changes associated with prion diseases. The
study was published today, September 28, 2009, in the online journal PLoS ONE. Principal
investigator Gerold Schmitt-Ulms (Centre for Research in Neurodegenerative Diseases;
Department of Laboratory Medicine and Pathobiology, U of T) and his graduate student
Sepehr Ehsani teamed up with Holger Wille and Joel Watts (University of California, San
Francisco) and David Westaway (University of Alberta) for this project. "The prion
protein was discovered over twenty years ago and has been studied intensively. Nobody,
however, knew its evolutionary origin and much confusion surrounds its physiological
function," says Prof. Schmitt-Ulms. The team's analysis suggests that the prion gene
is descended from the more ancient ZIP family of metal ion transporters. Members of the
ZIP protein family are well known for their ability to transport zinc and other metals
across cell membranes. The U of T laboratory initially demonstrated the physical proximity
of two metal ion transporters, ZIP6 and ZIP10, to mammalian prion proteins in living
cells. As with the normal cellular prion protein, ZIP6 and ZIP10 exhibit widespread
expression in biological tissues with high transcript levels in the brain. Schmitt-Ulms
then made the startling discovery that prion and ZIP proteins contain extensive stretches
of similar amino acid sequence. The researchers next documented that the respective
segments within ZIP and prion proteins are computationally predicted to acquire a highly
similar three-dimensional structure. Finally, the team uncovered multiple additional
commonalities between ZIP and prion proteins which led them to conclude these molecules
are evolutionarily related.
Penn studies point to strategies
for reducing painful breast cancer drug side effects
Aromatase inhibitors, the same drugs that have buoyed long-term survival rates among
breast cancer patients, also carry side effects including joint pain so severe that many
patients discontinue these lifesaving medicines. New University of Pennsylvania School of
Medicine research, however, has uncovered patterns that may help clinicians identify and
help women at risk of these symptoms sooner in order to increase their chances of sticking
with their treatment regimen. In a study published recently in the journal Cancer,
researchers at Penn's Abramson Cancer Center found that estrogen withdrawal may play a
role in the onset of joint pain, also known as arthralgia, during treatment: Women who
stopped getting their menstrual periods less than five years before starting breast cancer
treatment were three times more likely to experience these pains than those who reached
menopause more than a decade earlier. In a separate study published in the journal
Integrative Cancer Therapies, the Penn researchers found that among women experiencing
these symptoms during treatment with aromatase inhibitors (AI), those who received
electro-acupuncture – a technique that combines traditional acupuncture with electric
stimulation – reported a reduction in joint pain severity and stiffness. Those women
also said they suffered less fatigue and anxiety. "We are fortunate today to have
many effective treatments for breast cancer. Unfortunately, many of these treatments have
troublesome and debilitating side effects that can last for months or years after
treatment, and really harm the quality of life and productivity of women who receive
them," says lead author Jun J. Mao, MD, MSCE, an assistant Professor of Family
Medicine and Community Health. "These findings are just a first step in our
comprehensive research program aimed at understanding the nature of treatment-related
symptoms, who is likely to get them, the mechanisms by which they occur, and how best to
treat them." Toxicity issues and side effects among patients taking aromatase
inhibitors – drugs used in post-menopausal women to prevent recurrence of breast
cancer following initial treatment, by reducing the amount of estrogen the body makes
– lead as many as 20 percent of patients to miss prescription refills or discontinue
their therapy altogether. Patients in the new study were taking aromatase inhibitors
including Arimidex, Femara or Aromasin. Of the 300 patients enrolled in the study, 139
reported AI-related pain, with 75 percent of those reporting symptoms that began within
the first three months of the therapy. Women most commonly had pain in their wrists,
hands, and knees, though more than half said they also had pain in their backs and ankles
or feet. Women who had their last menstrual period within the five years prior to
beginning AIs appeared to be three times more likely to have these symptoms than women
whose periods had stopped 10 or more years earlier. The authors say this finding indicates
that women who entered menopause more recently may have higher levels of residual
circulating estrogen in their bodies, which combined with exposure to AIs may cause a
steeper, quicker drop in estrogen levels, leading to worse symptoms.
Researchers believe hormone therapy
should not be stopped prior to mammograms
Researchers from Boston University School of Medicine (BUSM) are recommending that
menopausal women on hormone therapy (HT) continue their treatment prior to having their
annual mammogram screenings. These recommendations appear as an editorial in the current
on-line issue of Journal of the North American Menopause Society. Annual mammography
screening is credited with a significant reduction in breast cancer mortality in women
older than 50, and is considered a pillar of routine healthcare maintenance in most
populations. Sensitivity, specificity, and optimal performance of mammography depend on a
number of variables including breast density. While subjective and objective increases in
mammographic breast density have been reported in up to 30 percent of postmenopausal women
taking HT, the majority of women in this age group have low breast densities to start with
and the magnitude of the increase with HT is small in most. Furthermore, improvements in
screening technologies (digital mammography) have shown promise in overcoming hindrances
in denser breasts. It is thus extremely unlikely that a minor increase in density is going
to mask the mammographic detection of any early breast cancer if present. "We do not
believe everyone on HT should consider stopping treatment one to two months prior to their
mammogram," said lead author Raja Sayegh, MD, an associate professor of obstetrics
and gynecology at BUSM. "Such a practice is likely to precipitate the recurrence of
nuisance symptoms for which most menopausal women take HT nowadays, wih no convincing
evidence of improved screening accuracy. While there may be other good reasons to consider
stopping HT, improving the mammographic detection of early cancers should not be one of
them," he added. Instead, the researchers recommend that health care providers should
alert their HT patients to the possibility of an augmented mammographic density, or other
artifacts, that may require additional evaluation. "This should become part of the
office routine, as it has become part of mammography reporting routine. Women who have
thus been alerted, are less likely to be ridden with fear and anxiety when they receive a
recall notice from the mammography department," said Sayegh.
UCLA study identifies 2 chemicals
that could lead to new drugs for genetic disorders
UCLA scientists have identified two chemicals that convince cells to ignore premature
signals to stop producing important proteins. Published in the Sept. 28 edition of the
Journal of Experimental Medicine, the findings could lead to new medications for genetic
diseases, such as cancer and muscular dystrophy, that are sparked by missing proteins.
"When DNA changes, such as nonsense mutations, occur in the middle rather than the
end of a protein-producing signal, they act like a stop sign that tells the cell to
prematurely interrupt protein synthesis," explained Dr. Richard Gatti, professor of
pathology and laboratory medicine and human genetics at the David Geffen School of
Medicine at UCLA. "These nonsense mutations cause the loss of vital proteins that can
lead to deadly genetic disorders." Gatti's lab specializes in studying
ataxia-telangiectasia (A-T), a progressive neurological disease that strikes young
children, often killing them by their late teens or early 20s. For four years, the UCLA
Molecular Shared Screening Resources Center of the campus' California NanoSystems
Institute has screened 35,000 chemicals, searching for those that ignore premature stop
signals.First author Liutao Du developed the screening technology in Gatti's laboratory.
Diabetes weakens your bones
Current research suggests that the inflammatory molecule TNF-? may contribute to delayed
bone fracture healing in diabetics. The related report by Alblowi et al, "High Levels
of TNF-? Contribute to Accelerated Loss of Cartilage in Diabetic Fracture Healing"
appears in the October 2009 issue of the American Journal of Pathology. Diabetes, a
condition where the body either does not produce enough, or respond to, insulin, affects
at least 171 million people worldwide, a figure that is likely to double by 2030.
Long-term complications of diabetes include cardiovascular disease, chronic renal failure,
retinal damage that may lead to blindness, nerve damage, and blood vessel damage, which
may cause erectile dysfunction and poor wound healing. Diabetic patients often experience
low bone density, which is associated with increased risk of bone fractures and delayed
fracture repair. To examine how diabetes affects bone, Dr. Dana Graves and colleagues of
the University of Medicine and Dentistry of New Jersey and the Boston University School of
Medicine explored bone repair in a mouse model of diabetes. They observed increased levels
of inflammatory molecules, including TNF-? , during fracture healing. The diabetic animals
had rapid loss of cartilage in the healing bones, which was due to increased numbers of
osteoclasts, cells that remove bone and cartilage. Factors that stimulate osteoclast
formation were regulated by both TNF-? and a downstream mediator, FOXO1. These results
suggest that diabetes-mediated increases in TNF-? and FOXO1 may underlie the impaired
healing of diabetic fractures. Alblowi et al suggest that "TNF-? dysregulation plays
a prominent role in the recently identified catabolic events associated with diabetic
fracture healing." In future studies, Dr. Graves and colleagues plan to "examine
the effect of FOXO1 on mineralized tissue to examine how it may regulate factors that
control bone resorption and osteoclastogenesis, in addition to effects it may have on
osteoblastic cells."
Air Pollutants From Abroad a
Growing Concern, Says New Report
Plumes of harmful air pollutants can be transported across oceans and continents -- from
Asia to the United States and from the United States to Europe -- and have a negative
impact on air quality far from their original sources, says a new report by the National
Research Council. Although degraded air quality is nearly always dominated by local
emissions, the influence of non-domestic pollution sources may grow as emissions from
developing countries increase and become relatively more important as a result of
tightening environmental protection standards in industrialized countries. "Air
pollution does not recognize national borders; the atmosphere connects distant regions of
our planet," said Charles Kolb, chair of the committee that wrote the report and
president and chief executive officer of Aerodyne Research Inc. "Emissions within any
one country can affect human and ecosystem health in countries far downwind. While it is
difficult to quantify these influences, in some cases the impacts are significant from
regulatory and public health perspectives." The report examines four types of air
pollutants: ozone; particulate matter such as dust, sulfates, or soot; mercury; and
persistent organic pollutants such as DDT. The committee found evidence, including
satellite observations, that these four types of pollutants can be transported aloft
across the Northern Hemisphere, delivering significant concentrations to downwind
continents. Ultimately, most pollutants' impacts depend on how they filter down to the
surface. Current limitations in modeling and observational capabilities make it difficult
to determine how global sources of pollution affect air quality and ecosystems in downwind
locations and distinguish the domestic and foreign components of observed pollutants. Yet,
some pollutant plumes observed in the U.S. can be attributed unambiguously to sources in
Asia based on meteorological and chemical analyses, the committee said. For example, one
study found that a polluted airmass detected at Mt. Bachelor Observatory in central Oregon
took approximately eight days to travel from East Asia.
Sugar + weed killer = potential
clean energy source
A spoonful of herbicide helps the sugar break down in a most delightful way. Researchers
at Brigham Young University have developed a fuel cell – basically a battery with a
gas tank – that harvests electricity from glucose and other sugars known as
carbohydrates. The human body’s preferred energy source could someday power our
gadgets, cars or homes. “Carbohydrates are very energy rich,” said BYU chemistry
professor Gerald Watt. “What we needed was a catalyst that would extract the
electrons from glucose and transfer them to an electrode.”
A Pet in Your Life Keeps the Doctor
Away
Lowers blood pressure, encourages exercise, improves psychological health— these may
sound like the effects of a miracle drug, but they are actually among the benefits of
owning a four-legged, furry pet. This fall, the University of Missouri College of
Veterinary Medicine Research Center for Human-Animal Interaction (ReCHAI) will explore the
many ways animals benefit people of all ages during the International Society for
Anthrozoology and Human-Animal Interaction Conference in Kansas City, Mo., on Oct. 20-25.
“Research in this field is providing new evidence on the positive impact pets have in
our lives,” said Rebecca Johnson, associate professor in the MU Sinclair School of
Nursing, the College of Veterinary Medicine and director of ReCHAI. “This conference
will provide a unique opportunity to connect international experts working in human-animal
interaction research with those already working in the health and veterinary medicine
fields. A wonderful array of presentations will show how beneficial animals can be in the
lives of children, families and older adults.” Earlier this year, the Eunice Kennedy
Shriver National Institute of Child Health and Human Development (NICHD), one of the
National Institutes of Health (NIH), co-hosted two workshops with The WALTHAM® Centre for
Pet Nutrition, a division of Mars Incorporated, bringing together leading experts to
discuss the benefits of human-animal interaction in childhood. With support from a grant
from NICHD and sponsorship from WALTHAM®, the conference will continue this discussion.
Study shows more corn for biofuels
would hurt water
More of the fertilizers and pesticides used to grow corn would find their way into nearby
water sources if ethanol demands lead to planting more acres in corn, according to a
Purdue University study. The study of Indiana water sources found that those near fields
that practice continuous-corn rotations had higher levels of nitrogen, fungicides and
phosphorous than corn-soybean rotations. Results of the study by Indrajeet Chaubey, an
associate professor of agricultural and biological engineering, and Bernard Engel, a
professor and head of agricultural and biological engineering, were published in the early
online version of The Journal of Environmental Engineering. "When you move from
corn-soybean rotations to continuous corn, the sediment losses will be much greater,"
Chaubey said. "Increased sediment losses allow more fungicide and phosphorous to get
into the water because they move with sediment." Nitrogen and fungicides are more
heavily used in corn crops than soybeans, increasing the amounts found in the soil of
continuous-corn fields. Sediment losses become more prevalent because tilling is often
required in continuous-corn fields, whereas corn-soybean rotations can more easily be
no-till fields, Engel said.
Study Suggests Link Between
Psychosis and Creativity
Vincent van Gogh cut off his ear. Sylvia Plath stuck her head in the oven. History teems
with examples of great artists acting in very peculiar ways. Were these artists simply mad
or brilliant? According to new research reported in Psychological Science, a journal of
the Association for Psychological Science, maybe both. In order to examine the link
between psychosis and creativity, psychiatrist Szabolcs Kéri of Semmelweis University in
Hungary focused his research on neuregulin 1, a gene that normally plays a role in a
variety of brain processes, including development and strengthening communication between
neurons. However, a variant of this gene (or genotype) is associated with a greater risk
of developing mental disorders, such as schizophrenia and bipolar disorder. In this study,
the researchers recruited volunteers who considered themselves to be very creative and
accomplished. They underwent a battery of tests, including assessments for intelligence
and creativity. To measure creativity, the volunteers were asked to respond to a series of
unusual questions (for example, “Just suppose clouds had strings attached to them
which hang down to earth. What would happen?”) and were scored based on the
originality and flexibility of their answers. They also completed a questionnaire
regarding their lifetime creative achievements before the researchers took blood samples.
LSUHSC researcher identifies new
target to prevent fatal flu lung complication
Research led by Dr. Jay Kolls, Professor and Chairman of Genetics at LSU Health Sciences
Center New Orleans, has identified a therapeutic target for acute lung injury resulting in
acute respiratory distress syndrome, a highly fatal complication of influenza infection.
The research, which will be published in The Journal of Immunology in October, is
currently available in the Next in the JI section. Interleukin-17 (IL-17), an immune
system cell involved in proinflammatory response, is a potent regulator of neutrophils
(white blood cells). Following infection, IL-17 uses a signaling receptor called IL-17RA
to direct large numbers of neutrophils to the infection. Neutrophils play a key role in
the development of acute lung injury because they rapidly infiltrate the lung and are an
important source of cytokines (immunomodulating agents), a byproduct of which is swelling,
fluid in the lungs, and low levels of oxygen in the blood. The research team wanted to
determine whether blocking IL-17RA signaling would protect against acute lung injury
following influenza infection. Using an influenza model in control and knockout mice
(genetically engineered without IL-17RA), they worked to identify a pathway to control the
function of IL-17RA and the migration and action of neutrophils. They found decreased
levels of illness and death among the IL-17RA knockout mice, despite a higher viral load.
The researchers found that the knockout mice had fewer neutrophils in the lung, thus lower
levels of inflammation and less lung injury. Comparing their results to studies of IL-17RA
knockout mice in other models of viral infection, the researchers conclude that
therapeutic regulation of IL-17 signaling may be beneficial not only in acute lung injury,
but also in treating viral infections of other organs.
Study highlights HIV/AIDS challenge
in American prison system
HIV/Aids is up to five times more prevalent in American prisons than in the general
population. Adherence to treatment programs can be strictly monitored in prison. However,
once prisoners are released, medical monitoring becomes problematic. A new study by Dr.
Nitika Pant Pai – an Assistant professor of Medicine and a medical scientist at the
Research Institute of the MUHC – suggests the majority (76%) of inmates take their
antiretroviral treatment (ART) intermittently once they leave prison, representing a
higher risk to the general population. "Over a period of 9 years, we studied 512 HIV
positive repeat offender inmates from the San Francisco County jail system," says Dr.
Pant Pai. "Our results show that only 15% continuously took their ART between
incarcerations or after their release." According to the study, published in the
journal PLoS one, these figures highlight a lack of effectiveness on the part of medical
monitoring services for these people outside prison. "Taking ART intermittently is a
problem because it depletes the CD4 count - the immunizing cells that fight infection
– and increases the probability of developing resistance to the virus," says Dr.
Pant Pai. "The risk for rapid disease progression becomes higher and presents a risk
for public health transmission of HIV to their partners." According to the study
those on intermittent therapy were 1.5 times more likely to have higher virus load than
those on continuous therapy; those who never received therapy were 3 times more likely to
have a higher VL. "The optimal solution for treating patients and controlling the
HIV/Aids epidemic in the USA is to ensure continuous therapy," explains Dr. Milton
Estes, medical director of Forensic AIDS Project, San Francisco. "To achieve this we
must work on various aspects of the prisoner's lives, such as marginalization, psychiatric
problems and drug use, both before and after their departure from prison." According
to Dr. Jacqueline Tulsky, senior author of the study, "This research highlights the
need to examine ART policies inside and outside correctional settings with a view to
establishing effective life long management of HIV in prisoners."
Oleocanthal may help prevent, treat
Alzheimer's
Oleocanthal, a naturally-occurring compound found in extra-virgin olive oil, alters the
structure of neurotoxic proteins believed to contribute to the debilitating effects of
Alzheimer's disease. This structural change impedes the proteins' ability to damage brain
nerve cells. "The findings may help identify effective preventative measures and lead
to improved therapeutics in the fight against Alzheimer's disease," said study
co-leader Paul A.S. Breslin, PhD, a sensory psychobiologist at the Monell Center. Known as
ADDLs, these highly toxic proteins bind within the neural synapses of the brains of
Alzheimer's patients and are believed to directly disrupt nerve cell function, eventually
leading to memory loss, cell death, and global disruption of brain function. Synapses are
specialized junctions that allow one nerve cell to send information another. "Binding
of ADDLs to nerve cell synapses is thought to be a crucial first step in the initiation of
Alzheimer's disease. Oleocanthal alters ADDL structure in a way that deters their binding
to synapses," said William L. Klein, PhD, who co-led the research with Breslin.
"Translational studies are needed to link these laboratory findings to clinical
interventions." Klein is Professor of Neurobiology & Physiology, and a member of
the Cognitive Neurology and Alzheimer's Disease Center, at Northwestern University. Klein
and his colleagues identified ADDLs in 1998, leading to a major shift in thinking about
the causes, progression and treatment of Alzheimer's disease. Also known as beta-amyloid
oligomers, ADDLs are structurally different from the amyloid plaques that accumulate in
brains of Alzheimer's patients. Reporting on a series of in vitro studies, the team of
Monell and Northwestern researchers found that incubation with oleocanthal changed the
structure of ADDLs by increasing the protein's size. Knowing that oleocanthal changed ADDL
size, the researchers next examined whether oleocanthal affected the ability of ADDLs to
bind to synapses of cultured hippocampal neurons. The hippocampus, a part of the brain
intimately involved in learning and memory, is one of the first areas affected by
Alzheimer's disease.
Researchers find a key mechanism in
the development of nerve cells
Chaos brews in the brains of newborns: the nerve cells are still bound only loosely to
each other. Under the leadership of Academy Research Fellow Sari Lauri, a team of
researchers at the University of Helsinki has been studying for years how a neural network
capable of processing information effectively is created out of chaos. The team has now
found a new kind of mechanism that adjusts the functional development of nerve cell
contacts. The results were published in early September as the leading article of the
esteemed Journal of Neuroscience. The work carried out by Lauri's team and its partners at
the Viikki campus sheds light on a development path that results in some of the large
number of early synapses becoming stronger. The researchers found out hat the BDNF growth
factor of nerve cells triggers a functional chain which promotes the release of the
neurotransmitter glutamate. BDNF enables the release of glutamate by prohibiting the
function of kainate receptors which slow down the development of the preforms of the
synapses. The activity of the kainate receptors restricts the release of glutamate and the
development of synapses into functional nerve cell contacts. It is noteworthy that the
brain of a newborn itself seems to organise its own development. The electrical activity
of the waking brain triggers the series of events controlled by the BDNF protein, as a
result of which kainate receptor activity disappears in some synapses. The development is
based on the considerable plasticity of the developing neural network: it can reshape its
structureand function to a large extent. According to Lauri, the new research results help
understand how central nervous system diseases originating in early development are
established. The finding also provides researchers with the opportunity to obtain
information about the different aspects of endogenous activity of the brain. At the same
time, it could be possible to develop new kinds of pharmaceuticals for the treatment of
childhood epilepsy, for example. Lauri's team conducted the research in co-operation with
the research teams of Eero Castren and Tomi Taira from the Neuroscience Centre, and the
research team of Jari Yli-Kauhaluoma from the Faculty of Pharmacy.
New perspectives on cancer surgery
Instead of the classic scalpel, surgeons can also operate with an electroscalpel. A
significant advantage to this technique is that while a cut is being made, blood vessels
are closed off and hemorrhaging eliminated. Now another advantage may be added as well: a
German-Hungarian research team has developed a mass-spectrometry-based technique by which
tissues can be analyzed during a surgical procedure. As the team led by Zoltán Takáts
reports in the journal Angewandte Chemie, it may be possible to distinguish between
malignant tumor cells and the surrounding healthy tissue in real time during cancer
surgery. Until now, precise histological examination of the removed tissue has followed
after tumor surgery, and has required several days. If it reveals that the tumor has not
been completely removed, a second operation is needed. The new method may spare patients
this second surgery in the future. In electrosurgery, tissue is locally exposed to
high-frequency electrical current in order to guide a cut, remove tissue, or halt
bleeding. The tissue being treated becomes very hot and is partially vaporized. The
electrical current also generates electrically charged molecules during the vaporization.
The team of scientists from the University of Giessen, the Budapest firm Massprom,
Semmelweis University, and the National Research Institute for Radiobiology and
Radiohygiene, also in Budapest, made use of this process for their new method called rapid
evaporation ionization mass spectrometry, or REIMS. They equipped an electrosurgical
instrument with a special pump that sucks the vaporized cell components up through a tube
and introduces the charged molecules into a mass spectrometer. It turns out that mainly
lipids, the components of cell membranes, are registered by the mass spectrometer.
"Different tissue types demonstrate characteristic differences in their lipid
composition," explains Takáts. "Tumor tissue also differs from healthy
tissue." The scientists were able to develop a special algorithm to unambiguously
identify and differentiate between types of tissue.
Is trash the solution to tackling
climate change?
Converting the trash that fills the world's landfills into biofuel may be the answer to
both the growing energy crisis and to tackling carbon emissions, claim scientists in
Singapore and Switzerland. New research published in Global Change Biology: Bioenergy,
reveals how replacing gasoline with biofuel from processed waste could cut global carbon
emissions by 80%. Biofuels produced from crops have proven controversial because they
require an increase in crop production which has its own severe environmental costs.
However, second-generation biofuels, such as cellulosic ethanol derived from processed
urban waste, may offer dramatic emissions savings without the environmental catch.
"Our results suggest that fuel from processed waste biomass, such as paper and
cardboard, is a promising clean energy solution," said study author Associate
Professor Hugh Tan of the National University of Singapore. "If developed fully this
biofuel could simultaneously meet part of the world's energy needs, while also combating
carbon emissions and fossil fuel dependency." The team used the United Nation's Human
Development Index to estimate the generation of waste in 173 countries. This data was then
coupled to the Earthtrends database to estimate the amount of gasoline consumed in those
same countries. The team found that 82.93 billion litres of cellulosic ethanol could be
produced from the world's landfill waste and that by substituting gasoline with the
resulting biofuel, global carbon emissions could be cut by figures ranging from 29.2% to
86.1% for every unit of energy produced. "If this technology continues to improve and
mature these numbers are certain to increase," concluded co-author Dr. Lian Pin Koh
from ETH Zürich. "This could make cellulosic ethanol an important component of our
renewable energy future."
Institute for Aging Research study
links high-heels to heel and ankle pain
Women should think twice before buying their next pair of high-heels or pumps, according
to researchers at the Institute for Aging Research of Hebrew SeniorLife in a new study of
older adults and foot problems. The researchers found that the types of shoes women wear,
specifically high-heels, pumps and sandals, may cause future hind-foot (heel and ankle)
pain. Nearly 64 percent of women who reported hind-foot pain regularly wore these types of
shoes at some point in their life. "We found an increased risk of hind-foot pain
among women who wore shoes, such as high-heels or pumps, that lack support and sound
structure," says lead author Alyssa B. Dufour, a graduate student in the Institute's
Musculoskeletal Research Program. Published in the October issue of the journal Arthritis
Care & Research, the study is one of the first to examine the association between shoe
wear—beyond just high-heel use—and foot pain. The researchers, who analyzed
foot-examination data from more than 3,300 men and women in The Framingham Study, say past
shoe wear among women is a key factor for hind-foot pain. They found no significant link
between foot pain and the types of shoes men wear. While foot pain is a common complaint
in the U.S. adult population—foot and toe symptoms are among the top 20 reasons for
physician visits among those 65 to 74 years of age—relatively little is known about
the causes of foot pain in older adults. Women are more likely than men to have foot pain;
however, it is not known if this is due to a higher prevalence of foot deformities,
underlying disease, shoe wear, or other lifestyle choices. From a list of 11 shoe types,
study participants were asked about the one style of shoe they currently wear on a regular
basis, what they regularly wore during five age periods in the past, and if they
experience pain, aching or stiffness in either foot on most days. Nearly 30 percent of
women and 20 percent of men reported generalized foot pain, which is in line with other
foot-pain studies. Ms. Dufour's team, however, found a significant association in women
who reported hind-foot pain and past shoe wear that included high-heels and pumps.
Study suggests obesity alone does
not cause knee osteoarthritis in mice
In 2005 the World Health Organization (WHO) estimated that globally 400 million adults
were obese, defined by a body mass index (BMI) of 30 kg/m2 or greater. WHO projects that
by 2015 there will be more than 700 million obese adults worldwide. Obesity is considered
to be one of the greatest risk factors for osteoarthritis, a progressive musculoskeletal
disorder that is characterized by loss of joint cartilage. Researchers from Duke
University, supported by a grant for the National Institutes of Health (NIH), studied
leptin-deficient mice to determine the role of obesity in developing knee osteoarthritis
(OA). Researchers believed that obesity caused by a leptin deficiency would result in a
higher incidence of knee OA. Mice with a disruption of leptin signaling showed a 3-fold
increase in body mass and 10-fold increase in body fat, but surprisingly did not display
effects of knee OA. The findings of this study are published in the October issue of
Arthritis & Rheumatism, a journal of the American College of Rheumatology. The Duke
Researchers compared leptin-deficient and leptin receptor-deficient female mice with
wild-type mice to further understand the role this deficiency may play in increasing risk
of knee OA. At 10-12 months of age mice were measured for body fat content and blood
samples were taken to determine the level of inflammation in the animals. Knee joints were
analyzed to determine bone thickness and to look for degenerative changes in the lateral
femur, lateral tibia, medial femur, and medial tibia. Leptin is a protein hormone that is
produced by fat cells and responsible for regulating appetite and metabolism. The amount
of leptin in the body increases as body fat increases with obese people having high
concentrations of the hormone circulating in their bodies. Though higher levels of leptin
are present in obese individuals, it appears they have a resistance to the effects of the
hormone where the body does not receive the signal it is full after eating.
Social isolation worsens cancer
Using mice as a model to study human breast cancer, researchers have demonstrated that a
negative social environment (in this case, isolation) causes increased tumor growth. The
work shows—for the first time—that social isolation is associated with altered
gene expression in mouse mammary glands, and that these changes are accompanied by larger
tumors. "This interdisciplinary research illustrates that the social environment, and
a social animal's response to that environment, can indeed alter the level of gene
expression in a wide variety of tissues, not only the brain," said Suzanne D. Conzen,
MD, associate professor of medicine at the University of Chicago and senior author of the
study, to be published on September 30, 2009, in Cancer Prevention Research. "This is
a novel finding and may begin to explain how the environment affects human susceptibility
to other chronic diseases such as central obesity, type 2 diabetes, hypertension,
etc." The research began six years ago when cancer specialist Conzen joined forces
with biobehavioral psychologist Martha McClintock, PhD, professor of psychology and
founder of the Institute for Mind and Biology at the University of Chicago, who has long
been interested in the result of social isolation in aging, to study behavior and cancer
in a mouse model. The University of Chicago scientists took mice that were genetically
predisposed to develop mammary gland (breast) cancer and raised them in two environments:
in groups of mice and isolated. After the same amount of time, the isolated mice grew
larger mammary gland tumors. They were also found to have developed a disrupted stress
hormone response. "I doubted there would be a difference in the growth of the tumors
in such a strong model of genetically inherited cancer simply based on chronic stress in
their environments, so I was surprised to see a clear, measurable difference both in
mammary gland tumor growth and interestingly in accompanying behavior and stress hormone
levels," Conzen said. The researchers then turned their attention to how the chronic
social environment affected the biology of cancer growth. In other words, they sought to
discover the precise molecular consequences of the stressful environment.
Chronic pain treatments work better
together, says Queen's anesthesiologist
People who suffer from debilitating neuropathic pain may get more relief and sleep better
by combining two commonly-prescribed drugs. A new, federally-funded study by Queen's
University researchers has found that taking the drugs together is a more effective
treatment than taking either of them individually. When given both an anti-seizure drug
(gabapentin) and an antidepressant (nortriptyline), patients suffering from neuropathic
pain caused by nerve damage or disease experienced less pain than when they took one or
the other individually, reports Ian Gilron, director of Clinical Pain Research for Queen's
Departments of Anesthesiology, and Pharmacology & Toxicology, and an anesthesiologist
at Kingston General Hospital. "It was also exciting to discover the effect of this
combination on sleep interference," adds Dr. Gilron, noting that people rated sleep
interference with the combined drugs as 1.0 on a scale of 10, compared to 2.2 when they
took each drug individually. "That's a very important issue for this group of
patients, whose debilitating, unrelenting pain often interferes with normal sleep."
Less than half of medical students
understand health care system
Less than half of graduating medical students in the U.S. say they received adequate
training in understanding health care systems and the economics of practicing medicine,
according to a study conducted by the University of Michigan Medical School. The national
survey of more than 58,000 medical students from 2003-2007 showed an overwhelming majority
were confident about their clinical training. But when it came to understanding health
economics, the health care system, managed care, managing a practice or medical
record-keeping, 40 percent to 50 percent of students reported feeling inadequately
prepared.
Physician-assisted suicide does not
increase severity of depression, grief among family members
Unlike other forms of suicide, physician assisted death does not cause substantial regret,
or a sense of rejection among surviving family members. In addition, the prevalence and
severity of depression and grief among family members whose loved ones received aid in
dying is no different than family members whose loved ones did not pursue physician
assisted suicide. These findings are the result of a study conducted by researchers at
Oregon Health & Science University and published online this week in the Journal of
Pain and Symptom Management."Grief following the death of a loved one can be
persistent, painful and debilitating," said Linda Ganzini, M.D., a professor of
psychiatry and medicine in the OHSU School of Medicine and lead author of the research
paper. "Prior studies on suicides indicate high levels of shame, guilt, stigma and
sense of rejection in surviving family members. However, until now, little was known about
mental health outcomes in the family members of a patient who receives physician aid in
dying. Based on our research, we know that family members of loved ones who pursue
physician assisted suicide do not have different prevalence and severity of depression and
prolonged grief compared to the general population." To conduct the study,
researchers surveyed 95 family members whose loved ones requested aid in dying through
Oregon's Death with Dignity Act. This group included 59 family members whose loved one
received a lethal prescription and 36 whose loved one died by lethal ingestion. The
researchers compared this information with responses received from 63 family members whose
loved one had died from cancer or amyotrophic lateral sclerosis (Lou Gehrig's disease) and
had not requested aid in dying.In comparing survey results, the researchers found that the
rate of grief and depression between these two groups was nearly identical. However,
family members of loved ones who requested a lethal prescription indicated they felt more
prepared for and more accepting of the death.
Denial of service denial
A way to filter out denial of service attacks on computer networks, including cloud
computing systems, could significantly improve security on government, commercial, and
educational systems. Such a filter is reported in the Int. J. Information and Computer
Security by researchers from Auburn University in Alabama. Denial of Service (DoS) and
distributed Denial of Service (DDoS) attacks involve an attempt to make a computer
resource unavailable to its intended users. This may simply be for malicious purposes as
is often the case when big commercial or famous web sites undergo a DDoS attack. However,
it is also possible to exploit the system's response to such an attack to break system
firewalls, access virtual private networks, and to access other private resources. A DoS
attack can also be used to affect a complete network or even a whole section of the
Internet. Commonly, attack involves simply saturating the target machine with external
internet requests. In the case of a DDoS attack the perpetrator recruits other unwitting
computers into a network and uses a multitude of machines to mount the attack. The result
is that the resource, whether it is a website, an email server, or a database, cannot
respond to legitimate traffic in a timely manner and so essentially becomes unavailable to
users. Methods for configuring a network to filter out known DoS attack software and to
recognize some of the traffic patterns associated with a mounting DoS attack are
available. However, current filters usually rely on the computer being attacked to check
whether or not incoming information requests are legitimate or not. This consumes its
resources and in the case of a massive DDoS can compound the problem.
Teen attitudes toward smoking
linked to likelihood of drinking and using drugs
New research by Weill Cornell Medical College researchers looks at the specific ways
parents and peers influence teenagers to smoke, drink and use marijuana in combination.
Among their findings: attitudes toward smoking influenced teenagers' use of multiple drugs
(smoking, drinking and marijuana), and that this manifested itself differently in boys and
girls. For girls, friends were shown to be central. Ambivalent or permissive attitudes
within their social group toward smoking were associated with poly-drug use -- defined as
two or more of the following behaviors: smoking, drinking and marijuana use. This wasn't
the case with boys, whose poly-drug use was instead predicted by the extent to which they
perceived smoking to be prevalent in their larger age group -- not just among their
friends. "If a teenager feels smoking is socially acceptable and widely practiced,
they are much more likely not only to smoke, but to also drink and possibly use
marijuana," says lead author Dr. Jennifer A. Epstein, assistant professor of public
health in the Division of Prevention and Health Behavior at Weill Cornell Medical College.
"While the differences between how boys and girls are influenced by these social
factors are subtle, they could help us develop new gender-specific educational tactics for
preventing these behaviors." The study also revealed several factors that were the
same for boys and girls. When their friends drank alcohol or smoked or when their parents
had permissive or ambivalent attitudes toward drinking, both teenage boys and girls were
more likely to report poly-drug use. Other major variables included teenagers' inability
to refuse drugs and achieve goals through their own efforts.
Getting plants to rid themselves of
pesticide residues
Scientists in China have discovered that a natural plant hormone, applied to crops, can
help plants eliminate residues of certain pesticides. The study is in the current issue of
ACS' Journal of Agricultural and Food Chemistry, a bi-weekly publication. Jing Quan Yu and
colleagues note that pesticides are essential for sustaining food production for the
world's growing population. Farmers worldwide use about 2.5 million tons of pesticides
each year. Scientists have been seeking new ways of minimizing pesticide residues that
remain in food crops after harvest — with little success. Previous research suggested
that plant hormones called brassinosteroids (BRs) might be an answer to the problem. The
scientists treated cucumber plants with one type of BR then treated the plants with
various pesticides, including chloropyrifos (CPF), a broad-spectrum commercial
insecticide. BR significantly reduced their toxicity and residues in the plants, they say.
BRs may be "promising, environmentally friendly, natural substances suitable for wide
application to reduce the risks of human and environmental exposure to pesticides,"
the scientists note. The substances do not appear to be harmful to people or other
animals, they add.
Taking sharper aim at stomach ulcer
bacteria
Scientists are reporting discovery of a much sought after crack in the armor of a common
microbe that infects the stomachs of one-sixth of the world's population, causing stomach
ulcers and other diseases. They identified a group of substances that block a key chemical
pathway that the bacteria need for survival. Their study, which could lead to new, more
effective antibiotics to fight these hard-to-treat microbes, is scheduled for the October
16 issue of ACS Chemical Biology, a monthly journal. Javier Sancho and colleagues note in
the new study that Helicobacter pylori ( H. pylori ) bacteria infect the stomach lining
and can cause gastritis and ulcers. Treatment with broad-spectrum antibiotics can cure H.
pylori infections. However, an estimated one billion people remain infected worldwide
because of the cost of existing antibiotics and the emergence of antibiotic resistant
strains of the bacteria, the researchers say. The scientists knew from past research that
blocking flavodoxin, a key protein that H. pylori needs for survival, could be the key to
developing narrow-spectrum antibiotics that specifically target H. pylori. Sancho's team
screened 10,000 chemicals for their ability to block flavodoxin and identified four that
showed promise. They then showed that three of the four substances killed H. pylori in
cell cultures and did not have any apparent toxic effects in lab animals. "These new
inhibitors constitute promising candidates to develop new specific antibiotics against H.
pylori," the study states.
A potential new imaging agent for
early diagnosis of most serious skin cancer
Scientists in Australia are reporting development and testing in laboratory animals of a
potential new material for diagnosing malignant melanoma, the most serious form of skin
cancer. Their study is scheduled for the September 10 issue of the ACS' Journal of the
Medicinal Chemistry, a bi-weekly publication. Ivan Greguric and colleagues working within
the Cooperative Research Consortium for Biomedical Imaging Develop, an Australian
Government funded research group, note that about 130,000 new cases of malignant melanoma
occur each year worldwide. Patients do best with early diagnosis and prompt treatment. The
positron emission tomography (PET) scans sometimes used for diagnosis sometimes miss small
cancers, delaying diagnosis and treatment. The scientists' search for better ways of
diagnosis led them to a new group of radioactive imaging agents, called
fluoronicotinamides, which they tested in laboratory mice that had melanoma. The most
promising substance revealed melanoma cells with greater accuracy than imaging agents now
in use, the scientists note. As a result, this substance could become a
"superior" PET imaging agent for improving the diagnosis and monitoring the
effectiveness of treatment of melanoma, they say. Clinical trials with this new agent are
now scheduled for 2010.
A new chemical method for
distinguishing between farmed and wild salmon
Wild salmon and farmed salmon can now be distinguished from each other by a technique that
examines the chemistry of their scales. Dr Clive Trueman, who is based at the National
Oceanography Centre, Southampton said "Salmon farming is a big, intensive business.
In 2006, around 130,000 tonnes of salmon were farmed in Scotland for the table. Wild
populations of Atlantic salmon are in serious decline across their whole range and the
total wild population returning to Scottish rivers in the same year is estimated at less
than 5000 tonnes. Wild fish are rare and expensive so there is a strong incentive for
fraudulent labelling. Farmed fish also escape into rivers, harming the wild population.
Unfortunately, it can be difficult to distinguish between farmed and wild fish"The
new work which was done in collaboration with the Scottish Association for Marine Science
(SAMS), Oban, will help crack this problem. Fish scales are formed from the same chemicals
as bones and teeth and grow like tree rings, preserving a chemical record of the water the
fish lived in throughout its whole life. Scales are easy to collect, and can be removed
from fish without harming them – which is important when studying an endangered
population. The team discovered that levels of the trace metal manganese were always much
higher in fish of farmed origin.
Study in Spain and Romania confirms
radon as second leading cause of lung cancer
Exposure to radon gas in homes is the second leading cause of lung cancer after smoking,
according to a study carried out by researchers from the University of Cantabria and the
Babes-Bolyai University in Romania. The team has studied data on exposure to this element
in a uranium mining area in Transylvania and in an area of granite in Torrelodones,
Madrid. Numerous studies worldwide have shown that radon, a natural radioactive gas that
seeps into homes in some regions, is the second leading factor (after smoking) in causing
people to develop lung cancer. This has now also been confirmed by a study carried out in
Torrelodones, Madrid, and Stei, in Romania, by researchers from the University of
Cantabria and the Romanian Babes-Bolyai University, and which has been published recently
in the journal Science of the Total Environment. The authors estimated the death rate due
to lung cancer attributable to radon and smoking in the areas studied between 1994 and
2006, using population data from the National Statistics Institute (INE), and data on
radon exposure conditions and related risks taken from European epidemiological studies.
The result was double that which would have been expected based on a relative risk report
produced in 2006 for the whole of Europe on cancer incidence and mortality. "The
study shows that radon is the second leading cause of lung cancer, after smoking, as has
also been shown by many other studies carried out over the years in various parts of the
world", Carlos Sainz, co-author of the study and a researcher for the Ionizing
Radiation Group at the University of Cantabria, tells SINC.
Research puts a 'Fas' to the cause
of programmed cell death
Walter and Eliza Hall Institute researchers have put an end to a 10-year debate over which
form of a molecular messenger called Fas ligand is responsible for killing cells during
programmed cell death (also called apoptosis). Apoptosis is an important process in human
biology as it removes unwanted and dangerous cells from our bodies, protecting us against
cancer development and diseases where the immune system attacks the body's own tissues,
such as in lupus or insulin-dependent diabetes. This cell death process can be activated
by proteins on the surface of cells. The most prominent of these cell surface proteins is
Fas ligand, which exists in two forms – membrane-bound or secreted – and binds
to a surface receptor called Fas. Professor Andreas Strasser, co-head of the institute's
Molecular Genetics of Cancer division (with Professor Jerry Adams), has been looking to
settle a decade-long scientific debate by investigating whether membrane-bound Fas ligand,
secreted Fas ligand, or both, cause cell death. "There has been a lot of debate among
the scientific community over which of the forms causes cell death but also which of the
forms may induce an inflammatory response," Professor Strasser said. "What we
have shown is that it is the membrane-bound Fas ligand that is essential for cell death
and is therefore the body's guardian against lymphadenopathy (the swelling of lymph
nodes), autoimmunity and cancer." Professor Strasser's research, done in
collaboration with Dr Lorraine O'Reilly and Ms Lin Tai from the Molecular Genetics of
Cancer division and Dr Lorraine Robb from the Cancer and Haematology division, has been
published in today's issue of the international journal Nature.
Malaria research wins Jake Baum a
Young Tall Poppy award
“Malaria parasites use a unique actin-myosin motor that enables them to literally
glide across cell surfaces and enter host cells,” Dr Baum said. “The components
of this gliding motor are well established yet we still know almost nothing about how
motility is regulated.”
Scientists discover clues to what
makes human muscle age
A study led by researchers at the University of California, Berkeley, has identified
critical biochemical pathways linked to the aging of human muscle. By manipulating these
pathways, the researchers were able to turn back the clock on old human muscle, restoring
its ability to repair and rebuild itself. The findings will be reported in the Sept. 30
issue of the journal EMBO Molecular Medicine, a peer-reviewed, scientific publication of
the European Molecular Biology Organization. "Our study shows that the ability of old
human muscle to be maintained and repaired by muscle stem cells can be restored to
youthful vigor given the right mix of biochemical signals," said Professor Irina
Conboy, a faculty member in the graduate bioengineering program that is run jointly by UC
Berkeley and UC San Francisco, and head of the research team conducting the study.
"This provides promising new targets for forestalling the debilitating muscle atrophy
that accompanies aging, and perhaps other tissue degenerative disorders as well."
Previous research in animal models led by Conboy, who is also an investigator at the
Berkeley Stem Cell Center and at the California Institute for Quantitative Biosciences
(QB3), revealed that the ability of adult stem cells to do their job of repairing and
replacing damaged tissue is governed by the molecular signals they get from surrounding
muscle tissue, and that those signals change with age in ways that preclude productive
tissue repair. Those studies have also shown that the regenerative function in old stem
cells can be revived given the appropriate biochemical signals. What was not clear until
this new study was whether similar rules applied for humans. Unlike humans, laboratory
animals are bred to have identical genes and are raised in similar environments, noted
Conboy, who received a New Faculty Award from the California Institute of Regenerative
Medicine (CIRM) that helped fund this research. Moreover, the typical human lifespan lasts
seven to eight decades, while lab mice are reaching the end of their lives by age 2.
Consciousness is the brain's Wi-Fi,
resolving competing requests, study suggests
Your fingers start to burn after picking up a hot plate. Should you drop the plate or save
your meal? New research suggests that it is your consciousness that resolves these
dilemmas by serving as the brain's Wi-Fi network, mediating competing requests from
different parts of the body. Published today in the journal Emotion, the study also
explains why we are consciously aware of some conflicting urges but not others. "If
the brain is like a set of computers that control different tasks, consciousness is the
Wi-Fi network that allows different parts of the brain to talk to each other and decide
which action 'wins' and is carried out," said San Francisco State University
Assistant Professor of Psychology Ezequiel Morsella, lead author of the study. The study
finds that we are only aware of competing actions that involve skeletal muscles that
voluntarily move parts of the body, the bicep for example, rather than the muscles in the
digestive tract or the iris of the eye. In lab experiments, participants were trained to
identify and report changes in their awareness, or the feeling of being about to make a
mistake, while in a state of readiness to perform simple exercises. The results
demonstrated that merely preparing to perform an incompatible action, for example
preparing to move simultaneously left and right, triggered stronger changes in awareness
than preparing to perform a compatible action or experiencing a conflict that does not
engage the muscles that move our bodies. Participants rated changes in their awareness on
an eight-point scale and reported an average rating of 4.5 when mentally preparing to
perform an incompatible action and an average rating of two for compatible actions.
Sexually satisfied women have
better general well-being and more vitality
Pre- and post-menopausal women who self-rated themselves as being sexually satisfied had a
higher overall psychological well-being score and scores for "positive
well-being" and "vitality," compared with sexually dissatisfied women in a
study of 295 women sexually active more than twice a month. The study, published today in
The Journal of Sexual Medicine, also uncovered a positive association between age and
well-being, but a negative association for general health. The most commonly reported
sexual problems in the area of consensual sexuality in women relate to sexual desire and
interest, pleasure and satisfaction, and for most women these are part of the overall
sexual experience, and are inextricably related. In contrast to studies of interventions
for male erectile dysfunction, benefit of treatment in women with sexual dysfunction
cannot be measured simply by the frequency of sexual events, as women frequently continue
to be sexually active despite a high level of sexual dissatisfaction. Thus the frequency
of self-reported satisfactory sexual events has been used as the primary outcome in recent
studies. To assess whether there was a correlation between sexual satisfaction and
well-being, the team of Australian researchers recruited women from the community aged
20-65 who self-identified as being satisfied or dissatisfied with their sexual function.
Participants were also asked questions which identified whether they were pre- or post
menopausal, with recruitment closed when there was an equal number of women in each of the
four subgroups. "We wanted to explore the links between sexual satisfaction and
wellbeing in women from the community, and to see if there was any difference between pre-
and postmenopausal women," said lead author Dr Sonia Davison, of the Women's Health
Program at Monash University, Australia. "We found that women who were sexually
dissatisfied had lower well-being and lower vitality. This finding highlights the
importance of addressing these areas as an essential part of women's healthcare, because
women may be uncomfortable discussing these issues with their doctor."
Putting the squeeze on sperm DNA
In the quest for speed, olympic swimmers shave themselves or squeeze into high-tech
super-suits. In the body, sperm are the only cells that swim and, as speed is crucial to
fertility, have developed their own ways to become exceptionally streamlined. Scientists
at the European Molecular Biology Laboratory (EMBL) in Heidelberg and Grenoble, the
Institut de Biologie Structurale (IBS) and the Institut Albert Bonniot, both also in
Grenoble, have been studying the secrets of speedy sperm. Their work, published today in
Nature, shows how a protein only found in developing sperm cells, Brdt, directs tight
re-packaging of sperm DNA. Because it is such a long and unwieldy molecule, our DNA is
packaged for convenience into a complex structure called chromatin: long DNA strands are
wound around proteins called histones. In sperm, however, this package has become even
more compact, reducing the size of the sperm head and making it more hydrodynamic. The
nature of chromatin – how open or compact it is – is intricately regulated.
Histones are marked with different chemical tags, often several per histone, that act as a
code to direct changes in chromatin structure. Different proteins bind to the tags, the
combination of which deciphers the code. Until now, scientists thought that these proteins
bind using one or more modular 'domains', with each domain docking to just one tag.
However, this new study reports the discovery of an extra level of sophistication. The
researchers studied histone binding of a protein called Brdt, finding that it binds most
strongly to a histone with two of a particular tag (in this case, acetyl groups) –
and, contrary to expectations, uses just one protein domain to do so. "We were very
surprised," explains Christoph Müller of EMBL. "We looked at the structure and
saw that the domain forms a pocket, binding both tags at once."
Can strep throat cause OCD,
Tourette syndrome?
New research shows that streptococcal infection does not appear to cause or trigger
Tourette syndrome or obsessive-compulsive disorder (OCD). The research is published in the
September 30, 2009, online issue of Neurology®, the medical journal of the American
Academy of Neurology. "These results do not confirm other, smaller studies done in
the US, which found an association between strep infection and these brain
disorders," said study author Anette Schrag, MD, of the University College London in
the United Kingdom. "Streptococcal infection has previously also been linked to
other, much rarer neuropsychiatric disorders." OCD is an anxiety disorder
characterized by unwanted thoughts or obsessions and repetitive behaviors. Tourette
syndrome is a neurologic disorder characterized by repetitive, involuntary sounds and
movements called tics. The study involved 255 people between the ages of two and 25 from a
large, unselective population in the United Kingdom. Of those, 129 were diagnosed with OCD
and 126 with Tourette syndrome or tics. Scientists compared the two groups with 4,519
people of similar ages without these disorders.
Australian study sheds light on
kidney repair and disease
A study by Monash University researchers has shed new light on the microscopic antennas in
the kidney that are involved in the organ's repair process. The work may be a crucial step
towards a cure for polycystic kidney disease, a potentially fatal disease that affects
more than one in 1000 people. The study, led by Dr James Deane a researcher at the Centre
for Inflammatory Disease at the Monash Medical Centre, showed how kidney repair processes
are controlled and helps explain the cause of polycystic kidney disease. The findings have
appeared in the latest edition of world's leading kidney research publication, the Journal
of the American Society of Nephrology. "We have shown for the first time that the
hair-like structures on kidney cells, called cilia, change their length in response to
injury in human patients, growing up to four times their original length in the later
stages of kidney repair," Dr Deane said. "These hair-like structures are
antennas and the increases in their length amplify the signals they send to kidney cells
at vital stages of repair. We think this is how they turn off the repair process when it
is complete and allow the kidney to start working normally again" Dr Deane said that
if the switching on and off the repair process is not properly controlled, rapidly
reproducing cells will distort the tubes of the kidney and prevent them from functioning
properly, which is what appears to happen in people that have polycystic kidney disease, a
condition which is currently untreatable. "Our research helps put a logical framework
behind what is happening in polycystic kidney disease, as the mutations that cause the
disease can damage the hair-like structures of kidneys cells," Dr Deane said.
Calcium scans may be effective
screening tool for heart disease
A simple, non-invasive test appears to be an effective screening tool for identifying
patients with silent heart disease who are at risk for a heart attack or sudden death.
Coronary artery calcium scans can be done without triggering excessive additional testing
and costs, according to the multi-center EISNER (Early Identification of Subclinical
Atherosclerosis by Noninvasive Imaging Research) study, led by investigators at the
Cedars-Sinai Heart Institute. The findings appear in today's issue of the Journal of the
American College of Cardiology. Coronary artery calcium scans that detect plaque in the
coronary arteries have been shown to be more effective than standard cholesterol and blood
pressure measurements in identifying patients who are most vulnerable to heart disease.
Currently, these scans are not covered by private insurance carriers, in part because of
concerns that detection of low levels of cardiovascular disease will result in unnecessary
and expensive further testing, including exercise imaging and invasive cardiac
catheterization procedures. "Over half of patients who suffer heart attacks have no
warning that they have heart disease until the heart attack occurs. If we knew the
patients were at risk, current treatments could prevent the majority of these unnecessary
events. We had to address the concerns about unnecessary testing and costs related to this
potentially lifesaving procedure," said Daniel S. Berman, M.D., the study's principal
investigator and chief of Cardiac Imaging at Cedars-Sinai's S. Mark Taper Foundation
Imaging Center in Los Angeles. In the EISNER study, supported by The Eisner Foundation,
researchers performed coronary calcium scans on 1,361 volunteers at intermediate risk for
coronary artery disease, and followed them over a four-year period, from May 2001 to June
2005. The objective was to determine the relationship between coronary artery calcium
scores and subsequent cardiac events and to evaluate the performance of additional cardiac
diagnostic testing. Coronary artery calcium scores of 0 indicate no plaque, 1-9 minimal,
10-99 mild, 100-399 moderate, 400-999 extensive, and 1,000 or more very extensive plaque.
Stem cell success points to way to
regenerate parathyroid glands
In early laboratory success is taking University of Michigan researchers a step closer to
parathyroid gland transplants that could one day prevent a currently untreatable form of
bone loss associated with thyroid surgery. The scientists were able to induce embryonic
stem cells to differentiate into parathyroid cells that produced a hormone essential to
maintaining bone density. The laboratory results in live cell cultures, published in Stem
Cells and Development, need to be tested in further pre-clinical studies. Parathyroid
glands, four glands each the size of a rice grain that lie next to the thyroid in the
neck, are easily damaged when surgeons operate on patients with cancerous or benign
thyroid tumors. Without their calcium-regulating hormone, patients can develop
osteomalacia, a severe form of bone loss similar to rickets that affects tens of thousands
of people in the United States with muscle cramps and numbness in the hands and feet.
"We used human embryonic stem cells as a model for ways to work out the recipe to
make parathyroid cells," says Gerard M. Doherty, M.D., chief of endocrine surgery and
Norman W. Thompson Professor of Endocrine Surgery at U-M Medical School. The research
illustrates the payoff of rapidly increasing knowledge about how embryonic stem cells give
rise to other kinds of cells. That knowledge can be the springboard for influencing other
cells to regenerate damaged parts of the body.
Metabolic syndrome linked to liver
disease in obese teenaged boys
Researchers studying a large sample of adolescent American boys have found an association
between metabolic syndrome, which is a complication of obesity, and elevated liver enzymes
that mark potentially serious liver disease. The link between metabolic syndrome and the
suspected liver disease did not appear in adolescent girls, said study leader Rose C.
Graham, M.D., a pediatric gastroenterologist at The Children's Hospital of Philadelphia.
There were ethnic differences among the boys as well, she added, between Hispanic and
non-Hispanic males. The study appears in the October 2009 print edition of the Journal of
Pediatric Gastroenterology and Nutrition. Metabolic syndrome is of concern as a risk
factor for cardiovascular disease and type 2 diabetes, and is estimated to occur in 22
percent of U.S. adults and 4 percent of U.S. adolescents. It is defined by insulin
resistance, increased waist circumference, high blood pressure, and abnormal measures of
high density lipoprotein ("good cholesterol") and triglycerides in the blood.
The criteria are similar for pediatric metabolic syndrome, although there is some dispute
over details of the definition. In adults, researchers have shown an association between
metabolic syndrome and a group of diseases called nonalcoholic fatty liver disease
(NAFLD), which at its most severe, may progress to irreversible liver damage. The purpose
of the current study was to investigate to what extent metabolic syndrome in adolescents
was associated with elevated levels of the liver enzyme alanine aminotransferase (ALT), a
marker of NAFLD. Graham and colleagues analyzed a nationally representative sample of
1,323 U.S. adolescents, aged 12 to 19, from the National Health and Nutrition Examination
Survey. They found a strong association between metabolic syndrome and elevated ALT levels
in adolescent males, but not in adolescent females.
LSUHSC researcher identifies new
target to prevent fatal flu lung complication
Research led by Dr. Jay Kolls, Professor and Chairman of Genetics at LSU Health Sciences
Center New Orleans, has identified a therapeutic target for acute lung injury resulting in
acute respiratory distress syndrome, a highly fatal complication of influenza infection.
The research, which will be published in The Journal of Immunology in October, is
currently available in the Next in the JI section online. Interleukin-17 (IL-17), an
immune system cell involved in proinflammatory response, is a potent regulator of
neutrophils (white blood cells). Following infection, IL-17 uses a signaling receptor
called IL-17RA to direct large numbers of neutrophils to the infection. Neutrophils play a
key role in the development of acute lung injury because they rapidly infiltrate the lung
and are an important source of cytokines (immunomodulating agents), a byproduct of which
is swelling, fluid in the lungs, and low levels of oxygen in the blood. The research team
wanted to determine whether blocking IL-17RA signaling would protect against acute lung
injury following influenza infection. Using an influenza model in control and knockout
mice (genetically engineered without IL-17RA), they worked to identify a pathway to
control the function of IL-17RA and the migration and action of neutrophils. They found
decreased levels of illness and death among the IL-17RA knockout mice, despite a higher
viral load. The researchers found that the knockout mice had fewer neutrophils in the
lung, thus lower levels of inflammation and less lung injury. Comparing their results to
studies of IL-17RA knockout mice in other models of viral infection, the researchers
conclude that therapeutic regulation of IL-17 signaling may be beneficial not only in
acute lung injury, but also in treating viral infections of other organs. "Each year,
more than 200,000 people are hospitalized with flu-related complications in the United
States," notes Dr. Kolls. "A number of those who have died from H1N1 flu this
year have had lung damage different than we typically see with seasonal flu. These cases
have been marked by deep lung infections with diffuse damage to the alveoli – the
structures that deliver oxygen to the blood. Advancing our findings has the potential to
benefit both."
Most would refuse emergency use
H1N1 vaccine or additive
A majority of Americans would not take an H1N1 flu vaccine or drug additive authorized for
emergency use by the Food and Drug Administration, according to a University of Pittsburgh
Graduate School of Public Health and University of Georgia study. The study, available
online today in Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and Science,
found that fewer than 10 percent of those surveyed said they would be willing to take such
a vaccine or drug and nearly 30 percent remained undecided. The passage of the Project
Bioshield Act in 2004 created the emergency use authorization (EUA) giving the FDA the
ability to use experimental or "off label" drugs in the event of an actual or
potential emergency. To date, four vaccines against H1N1 virus have been approved under
the same process used by the FDA for the seasonal flu vaccine. Also, several drug
additives, or adjuvants – sometimes added to vaccines to strengthen the immune
response and stretch the quantity of available vaccines in the event of a pandemic –
have been ordered and stockpiled by the federal government in case they may be needed. But
adding them to H1N1 vaccines would trigger an EUA, which is one of the reasons the federal
government has chosen not to use them. "Although the U.S government has held off on
including an adjuvant in H1N1 vaccines for now, American officials may need to reconsider
this decision as the pandemic unfolds," said study author Sandra Quinn, Ph.D.,
associate dean for Student Affairs and Education and associate professor at the University
of Pittsburgh Graduate School of Public Health. "There also remains a significant
shortage of the vaccines in many countries around the world. Given this, our finding that
few people would accept a new but not yet fully approved H1N1 vaccine or drug is very
worrisome," she said. The study was based on a survey that focused on attitudes
toward H1N1 and willingness to accept flu vaccines and drugs not officially approved by
the FDA, but authorized for emergency use. Of the 1,543 adults questioned in June 2009, 46
percent of people surveyed said they were concerned about getting swine flu. However,
nearly 86 percent said they thought it was unlikely or very unlikely that they themselves
would become ill.
Protein inhibitor helps rid brain
of toxic tau protein
Inhibiting the protein Hsp70 rapidly reduces brain levels of tau, a protein associated
with Alzheimer's disease when it builds up abnormally inside nerve cells affecting memory,
neuroscientists at the University of South Florida found. The study is reported online
today in the Journal of Neuroscience. "Now that we've discovered that targeting the
chaperone protein Hsp70 can clear tau, it could be helpful in finding more effective drugs
for Alzheimer's disease," said the study's senior author Chad Dickey, PhD, assistant
professor of molecular medicine who works out of the Byrd Alzheimer's Institute at USF
Health "The therapeutic strategy may also be applicable to other neurodegenerative
diseases involving Hsp70, such as Huntington disease, amyotrophic lateral sclerosis (ALS),
and some cancers." Hsp70 is a one of several "chaperone" proteins that
supervises the activity of tau inside nerve cells. The normal function of tau is to
support the structure of nerve cells, much like the skeleton provides a scaffold to
support the body. Tau is inside nerve cells, while another hallmark protein associated
with Alzheimer's, beta amyloid, is outside the neurons. Working with researchers at the
University of Michigan, the USF team tested the effects of several compounds on Hsp70 in
cell models and brain tissue from mice genetically modified to develop the memory-choking
tau tangles. Some compounds activated Hsp70, and others were Hsp70-inhibitors. One of the
more effective Hsp70-inhibitor drugs the researchers discovered was a derivative of
methylthioninium chloride, or Rember™, the first experimental medication reported to
directly attack the tau tangles in patients with Alzheimer's disease. Rember™ was
heralded as a major development in the fight against Alzheimer's when results in early
clinical trials were announced last year at the International Conference on Alzheimer's
disease.
Women fare better than men with
metastatic colorectal cancer -- are hormones helping?
Younger women with metastatic colorectal cancer lived longer than younger men. However,
this survival advantage disappeared with age, suggesting a benefit from estrogen or other
hormones, according to results of a study published in Clinical Cancer Research, a journal
of the American Association for Cancer Research. "We've known for a while that
estrogen prevents colorectal cancer, but this is the first study to suggest it may improve
outcomes once you have colorectal cancer," said Heinz-Josef Lenz, M.D., co-director
of gastrointestinal oncology and colorectal cancer at the University of Southern
California/Norris Comprehensive Cancer Center, Keck School of Medicine. Using the
Surveillance, Epidemiology and End Results registry, Lenz and colleagues screened 52,882
patients who had metastatic colorectal cancer between 1988 and 2004.
Lack of Social Interaction Affects
Health Outcomes of Breast Cancer
Social environment can play an important role in the biology of disease, including breast
cancer, and lead to significant differences in health outcome, according to results of a
study published in Cancer Prevention Research, a journal of the American Association for
Cancer Research. “This study uses an elegant preclinical model and shows that social
isolation alters expression of genes important in mammary gland tumor growth,” said
the journal’s Deputy Editor Caryn Lerman, Ph.D. “It further elucidates the
molecular mechanisms linking environmental stress with breast cancer development and
progression.” These findings suggest novel targets for chemoprevention, and future
studies should evaluate whether these molecular processes can be reversed by
chemopreventive agents, according to Lerman, who is the Mary W. Calkins professor of
psychiatry and scientific director of the Abramson Cancer Center at the University of
Pennsylvania, Philadelphia. Previous results from clinical studies have indicated that
social support can improve the health outcome of patients with breast cancer.
Epidemiological studies have suggested that social isolation increases the mortality risk
from several chronic diseases.
Orgasms, sexual health and
attitudes about female genitals
An Indiana University study published in the September issue of the International Journal
of Sexual Health found that women who feel more positively about women's genitals find it
easier to orgasm and are more likely to engage in sexual health promoting behaviors, such
as having regular gynecological exams or performing vulvar self-examinations. "These
are important findings about body image," said Debby Herbenick, associate director of
the Center for Sexual Health Promotion in the School of Health, Physical Education and
Recreation. "Our culture often portrays women's genitals as dirty and in need of
cleaning and grooming. Some women may have had greater exposure to such negative messages
or may be more susceptible to their impact." Herbenick's study created a scale for
measuring men's and women's attitudes toward women's genitals. Such a scale, she wrote in
the study, could be useful in sex therapy, in medical settings to help better understand
decision-making that goes into gynecological care and treatment, and in health education
settings involving women and their sexual health. The study also found that men had more
positive attitudes about women's genitals than women. "Women are often more critical
about their own bodies -- and other women's bodies -- than men are," Herbenick said.
"What we found in this study is that men generally feel positive about a variety of
aspects of women's genitals including how they look, smell, taste and feel."
Most would refuse emergency use
H1N1 vaccine or additive
A majority of Americans would not take an H1N1 flu vaccine or drug additive authorized for
emergency use by the Food and Drug Administration, according to a University of Pittsburgh
Graduate School of Public Health and University of Georgia study. The study, available
online today in Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and Science,
found that fewer than 10 percent of those surveyed said they would be willing to take such
a vaccine or drug and nearly 30 percent remained undecided. The passage of the Project
Bioshield Act in 2004 created the emergency use authorization (EUA) giving the FDA the
ability to use experimental or "off label" drugs in the event of an actual or
potential emergency. To date, four vaccines against H1N1 virus have been approved under
the same process used by the FDA for the seasonal flu vaccine. Also, several drug
additives, or adjuvants – sometimes added to vaccines to strengthen the immune
response and stretch the quantity of available vaccines in the event of a pandemic –
have been ordered and stockpiled by the federal government in case they may be needed. But
adding them to H1N1 vaccines would trigger an EUA, which is one of the reasons the federal
government has chosen not to use them. "Although the U.S government has held off on
including an adjuvant in H1N1 vaccines for now, American officials may need to reconsider
this decision as the pandemic unfolds," said study author Sandra Quinn, Ph.D.,
associate dean for Student Affairs and Education and associate professor at the University
of Pittsburgh Graduate School of Public Health. "There also remains a significant
shortage of the vaccines in many countries around the world. Given this, our finding that
few people would accept a new but not yet fully approved H1N1 vaccine or drug is very
worrisome," she said. The study was based on a survey that focused on attitudes
toward H1N1 and willingness to accept flu vaccines and drugs not officially approved by
the FDA, but authorized for emergency use. Of the 1,543 adults questioned in June 2009, 46
percent of people surveyed said they were concerned about getting swine flu. However,
nearly 86 percent said they thought it was unlikely or very unlikely that they themselves
would become ill.
Universal screening lowers risk of
severe jaundice in infants
Screening all newborns for excessive bilirubin in the blood can significantly decrease the
incidence of severe jaundice which, in extreme cases, can lead to seizures and brain
damage, according to researchers at UCSF Children's Hospital and Kaiser Permanente's
Division of Research in Oakland, CA. The study, one of the first to examine the
effectiveness of universal screening for hyperbilirubinemia, appears in the current issue
of "Pediatrics," the official journal of the American Academy of Pediatrics. The
study is one of six in this issue to explore the topic of bilirubin and
hyperbilirubinemia. Hyperbilirubinemia is caused by an elevation of a bile pigment, called
bilirubin, in the blood. Bilirubin is made when the body breaks down old red blood cells,
and high levels can cause jaundice, a condition that makes the newborn's skin and the
white part of the eyes look yellow. The researchers explain that most newborns have a rise
in bilirubin in the days following birth. However, very high blood levels can be toxic to
the nervous system. Monitoring these levels in babies with jaundice is important so that
treatment can be started before levels become excessive, explain the researchers. They add
that high bilirubin levels can be treated with light therapy, which converts the bilirubin
into a form that the body can remove. "While we know that early identification of
bilirubin levels before reaching toxic levels is important, bilirubin screening has not
been universal, as physicians have decided which infants to screen based upon their degree
of jaundice and clinical risk factors," said Michael Kuzniewicz, MD, MPH, the lead
author of the study and a neonatologist at UCSF Children's Hospital. "This study
provides evidence that universal screening during the birth hospitalization is a more
effective method for monitoring bilirubin levels in order to prevent them from rising to a
point that can damage an infant's brain."
Swiss study finds income affects
prostate cancer patients' survival
Prostate cancer patients of low socioeconomic status are more likely to die than patients
with higher incomes. That is the finding of a new study from Swiss researchers to be
published in the December 1, 2009 issue of Cancer, a peer-reviewed journal of the American
Cancer Society. The study's findings indicate that poor prostate cancer patients receive
worse care than their wealthier counterparts. Many of the previous studies on
socioeconomic status (SES) and prostate cancer mortality are from North America,
particularly from the United States. Researchers wanted to know how disparities affected
prostate cancer mortality in Switzerland, a country with an extremely well developed
health care system and where healthcare costs, medical coverage, and life expectancy are
among the highest in the world, Elisabetta Rapiti, M.D., MPH, of the University of Geneva
and her colleagues conducted a population-based study that included all residents of the
region who were diagnosed with invasive prostate cancer between 1995 and 2005. The
analysis included 2,738 patients identified through the Geneva Cancer Registry. A patient
with prostate cancer was classified as having high, medium, or low socioeconomic status on
the basis of his occupation at the time of diagnosis. The investigators compared patient
and tumor characteristics, as well as treatments among the different socioeconomic groups.
Compared with patients of high socioeconomic status, those of low socioeconomic status
were less likely to have their cancer detected by screening, had more advanced stages of
cancer at diagnosis, and underwent fewer tests to characterize their cancer. These
patients were less likely to have their prostates removed and were more likely to be
managed with watchful waiting, or careful monitoring.
New study resolves the mysterious
origin of Merkel cells
A new study resolves a 130-year-old mystery over the developmental origin of specialized
skin cells involved in touch sensation. The findings will appear in the October 5, 2009
issue of the Journal of Cell Biology (online September 28). First described in 1875,
Merkel cells are neuroendocrine cells that reside in the vertebrate epidermis, passing
mechanical stimuli on to sensory neurons. In mice, they are mainly found in the paws and
around the whiskers but, because they express proteins characteristic of both epithelial
and neuronal cells, scientists have long debated whether Merkel cells develop from the
epidermis or neural crest. Van Keymeulen et al. traced the lineage of Merkel cells by
fluorescently labeling cells derived from either epidermal or neural crest progenitors.
This revealed that Merkel cells originally emerge from the embryonic epidermis. In
addition, epidermal stem cells in adult mouse skin replenish the Merkel cell population as
they slowly die off over time. The researchers also found that a transcription factor
called Atoh1 is required for epidermal progenitors to differentiate into Merkel
cells—mice lacking Atoh1 in their skin failed to develop any of the
mechanotransducing cells.
Women with diabetes at increased
risk for irregular heart rhythm
Diabetes increases by 26 percent the likelihood that women will develop atrial
fibrillation (AF), a potentially dangerous irregular heart rhythm that can lead to stroke,
heart failure, and chronic fatigue. These are the findings of a new Kaiser Permanente
study, published in the October issue of Diabetes Care, a journal of the American Diabetes
Association. While other studies have found that patients with diabetes are more likely to
have AF, this is the first large study—involving nearly 35,000 Kaiser Permanente
patients over the course of seven years—to isolate the effect of diabetes and
determine that it is an independent risk factor for women. “The most important
finding from our study is that women with diabetes have an increased risk of developing
this abnormal heart rhythm,” said the study’s lead author, Greg Nichols, PhD,
investigator at the Kaiser Permanente Center for Health Research in Portland, Ore.
“Men with diabetes are also at higher risk, but the association between the two
conditions is not as strong. For men, obesity and high blood pressure are bigger risk
factors from diabetes.” “AF is the most common arrhythmia in the world, and
diabetes is one of the most common and costly health conditions. Our study points out that
there is a connection between these two growing epidemics—one we should pay closer
attention to, especially among women,” says Sumeet Chugh, MD, co-author and associate
director of the Cedars-Sinai Heart Institute in Los Angeles. “The gender differences
need to be looked at more closely because they could have significant implications for how
we treat diabetes in men and women.”
McMaster researchers discover a new
antibacterial lead
Antibiotic resistance has been a significant problem for hospitals and health-care
facilities for more than a decade. But despite the need for new treatment options, there
have been only two new classes of antibiotics developed in the last 40 years. Now a
promising discovery by McMaster University researchers has revealed an ideal starting
point to develop new interventions for resistant infections. Eric Brown, a professor and
chair of the Department of Biochemistry and Biomedical Sciences, and a team of researchers
from the Michael G. DeGroote Institute for Infectious Disease Research have identified a
novel chemical compound that targets drug-resistant bacteria in a different way from
existing antibiotics. The discovery could lead to new treatments to overcome antibiotic
resistance in certain types of microorganisms. The findings were published September 27 in
the science research journal Nature Chemical Biology.
U of T researchers create microchip
that can detect type and severity of cancer
UofT researchers have used nanomaterials to develop a microchip sensitive enough to
quickly determine the type and severity of a patient's cancer so that the disease can be
detected earlier for more effective treatment. Their groundbreaking work, reported Sept.
27 in Nature Nanotechnology heralds an era when sophisticated molecular diagnostics will
become commonplace. "This remarkable innovation is an indication that the age of
nanomedicine is dawning," says Professor David Naylor, president of the University of
Toronto and a professor of medicine. "Thanks to the breadth of expertise here at U of
T, cross-disciplinary collaborations of this nature make such landmark advances
possible." The researchers' new device can easily sense the signature biomarkers that
indicate the presence of cancer at the cellular level, even though these biomolecules
– genes that indicate aggressive or benign forms of the disease and differentiate
subtypes of the cancer – are generally present only at low levels in biological
samples. Analysis can be completed in 30 minutes, a vast improvement over the existing
diagnostic procedures that generally take days. "Today, it takes a room filled with
computers to evaluate a clinically relevant sample of cancer biomarkers and the results
aren't quickly available," says Shana Kelley, a professor in the Leslie Dan Faculty
of Pharmacy and the Faculty of Medicine, who was a lead investigator on the project and a
co-author on the publication. "Our team was able to measure biomolecules on an
electronic chip the size of your fingertip and analyse the sample within half an hour. The
instrumentation required for this analysis can be contained within a unit the size of a
BlackBerry."
Key to subliminal messaging is to
keep it negative, study shows
Subliminal messaging is most effective when the message being conveyed is negative,
according to new research funded by the Wellcome Trust. Subliminal images – in other
words, images shown so briefly that the viewer does not consciously 'see' them – have
long been the subject of controversy, particularly in the area of advertising. Previous
studies have already hinted that people can unconsciously pick up on subliminal
information intended to provoke an emotional response, but limitations in the design of
the studies have meant that the conclusions were ambiguous. Today, the journal Emotion
publishes a study by a UCL team led by Professor Nilli Lavie, which provides evidence that
people are able to process emotional information from subliminal images and demonstrates
conclusively that even under such conditions, information of negative value is better
detected than information of positive value. In the study, Professor Lavie and colleagues
showed fifty participants a series of words on a computer screen. Each word appeared
on-screen for only a fraction of second – at times only a fiftieth of a second, much
too fast for the participants to consciously read the word. The words were either positive
(e.g. cheerful, flower and peace), negative (e.g. agony, despair and murder) or neutral
(e.g. box, ear or kettle). After each word, participants were asked to choose whether the
word was neutral or 'emotional' (i.e. positive or negative), and how confident they were
of their decision. The researchers found that the participants answered most accurately
when responding to negative words – even when they believed they were merely guessing
the answer.
Metallic glass for bone surgery
It is possible that broken bones will in the near future be fixed using metallic glass.
Materials researchers at ETH Zurich have developed an alloy that could herald a new
generation of biodegradable bone implants. Their results have been published in the online
edition of Nature Materials. When bones break, surgeons need screws and metal plates to
fix the broken bones in place. These supports are usually made of stainless steel or
titanium. Once the bones have healed, the metal parts have to be removed from the body via
further surgery. In order to reduce the burden on patients, materials re-searchers have
taken up the task of producing implants from bioabsorbable metals. These implants should
stabilize the bones only for as long as they need to heal. The metal dissolves in the body
over time, rendering removal surgery unnecessary. Implants made of magnesium-based alloys
are proving particularly promising. Magnesium is mechanically stable and degrades
completely by releasing ions which are tolerated by the body. However, all magnesium
alloys have one major drawback: when they dissolve they produce hydrogen (H2), which can
be harmful to the body. Around the magnesium implants gas bubbles develop which hinder
bone growth and thus the healing process, and potentially cause infection.
Nanoparticles - toxic or harmless?
At SINTEF scientist both exploit the benefits of the nanotechnology and try to discover
how tiny particles could behave hazardous in nature. Andy Booth, SINTEF scientist and
environmental chemist is interested in what nanotechnology is doing to the marine
environment. A couple of years ago, he began to be interested in whether nanoparticles
could be hazardous. Now, Booth is leading a project called “The environmental fate
and effects of SINTEF-produced nanoparticles”. The scientists will study both how the
particles behave and how they affect organisms when they are released into the marine
environment. One of the goals of the project is to find out whether nanoparticles are
toxic to marine organisms such as small crustaceans and animal plankton. Further down the
road, the ability of cod larvae and other large organisms to tolerate nanoparticles will
also be studied. “Our experiments will tell us whether these tiny particles will be
excreted or remain inside organisms, and if they do, how they will behave there,”
explains Booth, who wants to make it clear that not all nanoparticles are necessarily
dangerous. Many types of nanoparticles occur naturally in the environment, and have
existed ever since the Earth was formed. For example, ash is a material that contains
nanoparticles.
Super bed sheet absorbs waste and
fluids
Astrid Skreosen has worked for many years as an auxiliary nurse in the maternity ward in
Skien Hospital. She became fed up with the little mats which were supposed to lie under
women who were giving birth, and were intended to soak up waste products and fluids.
“Restless women in labour and unstable mats made problems for everyone. None of these
underlays fitted the delivery beds, and we were wading in foetal fluids and blood. I was
just as irritated by people who said that we shouldn’t complain, but just make the
best of things,” says Skreosen, who decided to do something about the problem
herself.
Certain colours more likely to
cause epileptic fits
Researchers have discovered that epileptic brains are more ordered than non-epileptic ones
and also that certain flicking colours seem more likely to cause fits. In 1997, more than
seven hundred children in Japan suffered an epileptic attack while watching an episode of
Pokemon cartoon. This was later diagnosed as a case of photosensitive epilepsy (a kind of
epilepsy caused by visual stimulus) triggered by a specific segment of the cartoon
containing a colourful flickering stimulus. Recently in 2007, the animated video footage
promoting the 2012 London Olympics faced similar complaint from the viewers. Because of
the widespread usages of television and video games, it is important to detect the crucial
visual parameters in triggering an epileptic attack. Common guidelines are available on
specific visual parameters of the stimuli like spatial/temporal frequency, stimulus
contrast, patterns etc. However, despite the ubiquitous presence of colourful displays and
materials, very little is known about the relationship between colour-combinations
(chromaticity) and photosensitivity. Further it is also not precisely known how the
patients' brain responses differ from healthy brains against such colourful stimuli. In a
study published in the PLoS ONE on September 25, researchers led by Joydeep Bhattacharya
at Goldsmiths, University of London, investigated brain rhythms of photosensitivity
against combinational chromatic flickering in nine adult controls, an unmedicated patient
suffering from photosensitive epilepsy, two age-matched controls, and another medicated
patient.
Enzyme is key to clogged arteries
Scientists at Queen Mary, University of London have made an important discovery in
understanding what causes arteries to clog up. They have discovered that an enzyme called
matrix metalloproteinase-8 plays a crucial role in raising blood pressure and causing
abnormal build-up of cells in the arteries – both of which increase the risk of heart
disease. Heart disease is the number one cause of death in the UK. The scientists say that
their research could lead to new drugs for treating high blood pressure and preventing
heart disease. Shu Ye, Professor of Molecular Medicine and Genetics at Queen Mary,
University of London led the study. He explained: "Our research tells us that this
enzyme plays a crucial role in the build-up of fatty deposits in the arteries which causes
heart disease. "Many patients with high blood pressure or heart failure are currently
treated with ACE inhibitor drugs. However, some patients do not respond sufficiently to
ACE inhibitors alone. We hope that what we've found here could be the basis for new drugs
that can enhance the effects of ACE inhibitors, which would reduce deaths from heart
disease." The researchers studied mice which were genetically altered so they could
not produce the MMP8 enzyme. The mice were fed on a Western-style diet high in fat and
cholesterol and compared to normal mice fed on the same diet. The mice which lacked the
enzyme had clearer arteries and lower blood pressure. The researchers also studied 2,000
patients who were being tested for clogs in arteries leading to their hearts with a test
called a coronary angiogram. They found that around 25 per cent of these patients had a
slightly different version of the gene for MMP8 and their arteries were more clogged than
other patients.
Pancreatic cancer - Researchers
find drug that reverses resistance to chemotherapy
For the first time researchers have shown that by inhibiting the action of an enzyme
called TAK-1, it is possible to make pancreatic cancer cells sensitive to chemotherapy,
opening the way for the development of a new drug to treat the disease. Dr Davide Melisi
told Europe's largest cancer congress, ECCO 15 – ESMO 34 [1], in Berlin today
(Thursday 24 September) that resistance to chemotherapy was the greatest challenge to
treating pancreatic cancer."Pancreatic cancer is an incurable malignancy, resistant
to every anti-cancer treatment. Targeting TAK-1 could be a strategy to revert this
resistance, increasing the efficacy of chemotherapy," said Dr Melisi, who until the
start of September was a Fellow at the M.D. Anderson Center in Houston (Texas, USA); he
has now moved to a staff position at the National Cancer Institute in Naples (Italy).
"During the past few years we have been studying the role played by a cytokine or
regulatory protein called Transforming Growth Factor beta (TGFbeta) in the development of
pancreatic cancer. Recently we focused our attention on a unique enzyme activated by
TGFbeta, TAK-1, as a mediator for this extreme drug resistance." Dr Melisi and his
colleagues investigated the expression of TAK-1 (TGFbeta-Activated Kinase-1) in pancreatic
cell lines and developed a drug that was capable of inhibiting TAK-1. They tested the
activity of the TAK-1 inhibitor on its own and in combination with the anti-cancer drugs
gemcitabine, oxaliplatin and SN-38 (a metabolite of the anti-cancer drug irinotecan) in
cell lines, and the activity of the TAK-1 inhibitor combined with gemcitabine against
pancreatic cancer in mice. "The use of this TAK-1 inhibitor increased the sensitivity
of pancreatic cells to all three chemotherapeutic drugs. By combining it with classic
anti-cancer drugs, we were able to use doses of drugs up to 70 times lower in comparison
with the control to kill the same number of cancer cells. In mice, we were able to reduce
significantly the tumour volume, to prolong the mice survival, and to reduce the toxicity
by combining the TAK-1 inhibitor with very low doses of a classic chemotherapeutic drug,
gemcitabine, that would have been ineffective otherwise," said Dr Melisi. The use of
gemcitabine on its own against the cancer in mice was ineffective because of the drug
resistant nature of the disease. However, once it was combined with the TAK-1 inhibitor,
Dr Melisi and his colleagues saw a 78% reduction in tumour volumes. "The median
average survival for the control, TAK-1 inhibitor, gemcitabine on its own, or TAK-1
inhibitor combined with gemcitabine was 68, 87, 82 and 122 days respectively," he
said.
Sleep loss linked to increase in
Alzheimer's plaques
Chronic sleep deprivation in a mouse model of Alzheimer's disease makes Alzheimer's brain
plaques appear earlier and more often, researchers at Washington University School of
Medicine in St. Louis report online this week in Science Express. They also found that
orexin, a protein that helps regulate the sleep cycle, appears to be directly involved in
the increase. Neurodegenerative disorders like Alzheimer's disease and Parkinson's disease
often disrupt sleep. The new findings are some of the first indications that sleep loss
could play a role in the genesis of such disorders. "Orexin or compounds it interacts
with may become new drug targets for treatment of Alzheimer's disease," says senior
author David M. Holtzman, M.D., the Andrew and Gretchen Jones Professor and chair of the
Department of Neurology at the School of Medicine and neurologist-in-chief at
Barnes-Jewish Hospital. "The results also suggest that we may need to prioritize
treating sleep disorders not only for their many acute effects but also for potential
long-term impacts on brain health." Holtzman's laboratory uses a technique called in
vivo microdialysis to monitor levels of amyloid beta in the brains of mice genetically
engineered as a model of Alzheimer's disease. Amyloid beta is a protein fragment that is
the principal component of Alzheimer's plaques. Jae-Eun Kang, Ph.D., a post-doctoral
fellow in Holtzman's lab, noticed that brain amyloid beta levels in mice rose and fell in
association with sleep and wakefulness, increasing in the night, when mice are mostly
awake, and decreasing during the day, when they are mostly asleep. A separate study of
amyloid beta levels in human cerebrospinal fluid led by Randall Bateman, M.D., assistant
professor of neurology and a neurologist at Barnes-Jewish Hospital, also showed that
amyloid beta levels were generally higher when subjects were awake and lower when they
slept. To confirm the link, Kang learned to use electroencephalography (EEG) on the mice
at the Sleep and Circadian Neurobiology Laboratory at Stanford University with researchers
Seiji Nishino, M.D., Ph.D., and Nobuhiro Fujiki, M.D., Ph.D. The EEG readings let
researchers more definitively determine when mice were asleep or awake and validated the
connection: Mice that stayed awake longer had higher amyloid beta levels.
Environmental chemicals found in
breast milk and high incidence of testicular cancer
A comparison of breast milk samples from Denmark and Finland revealed a significant
difference in environmental chemicals which have previously been implicated in testicular
cancer or in adversely affecting development of the fetal testis in humans and animals.
This finding is published today in the International Journal of Andrology. In recent years
a worldwide increase in testicular cancer has been noticed, but the cause remains unknown.
In some countries, such as Denmark the prevalence of this disease and other male
reproductive disorders, including poor semen quality and congenital genital abnormalities
is conspicuously high; while in Finland, a similarly industrialized Nordic country, the
incidences of these disorders are markedly lower. In the UK, almost 2,000 men are
diagnosed with testicular cancer every year, and in the US this number is over 8,000.
There is a wide variation in incidence rates of testicular cancer around the globe, and
the reasons behind the observed trends are unexplained. Environmental endocrine disrupting
chemicals (EDCs) are commonly found in fatty foods, paints, plasticizers, pesticides, and
the byproducts of industrial processes, and in recent studies an association has been
shown between some of these agents and male reproductive problems. To investigate whether
EDCs could be related to such great differences in reproductive disorders between closely
related countries, Konrad Krysiak-Baltyn and colleagues from Denmark, Finland, and Germany
measured levels of 121 chemicals in 68 breast milk samples from Denmark and Finland to
compare exposure of mothers to EDCs. With so many chemicals, they used sophisticated,
bioinformatics tools to interpret the complex data, and the results showed a clear
distinction between the countries. "We were very surprised to find that some EDC
levels, including some dioxins, PCBs and some pesticides, were significantly higher in
Denmark than in Finland," said Professor Niels Skakkebaek, a senior member of the
research team, based at the University Department of Growth and Reproduction,
Rigshospitalet, Denmark. "Our findings reinforce the view that environmental exposure
to EDCs may explain some of the temporal and between-country differences in incidence of
male reproductive disorders." "In spite of the findings, I would strongly urge
women, including Danish mothers, to continue with breast feeding, which has many
beneficial effects for the child," added Skakkebaek.
Cracking the brain's numerical code
By carefully observing and analyzing the pattern of activity in the brain, researchers
have found that they can tell what number a person has just seen. They can similarly tell
how many dots a person has been presented with, according to a report published online on
September 24th in Current Biology, a Cell Press publication. These findings confirm the
notion that numbers are encoded in the brain via detailed and specific activity patterns
and open the door to more sophisticated exploration of humans' high-level numerical
abilities. Although "number-tuned" neurons have been found in monkeys,
scientists hadn't managed to get any farther than particular brain regions before now in
humans. "It was not at all guaranteed that with functional imaging it would be
possible to pick this up," said Evelyn Eger of INSERM in France. "In the monkey,
neurons preferring one or the other numerosity appear highly intermixed among themselves
as well as with neurons responding to other things, so it might seem highly unlikely that
with fMRI [functional magnetic resonance imaging] at 1.5 mm resolution—where one
voxel contains many thousands of neurons—one would be able to detect differences in
activity patterns between individual numbers. The fact that this worked means that there
is probably a somewhat more structured layout of preferences for individual numbers that
has yet to be revealed by neurophysiological methods." The researchers presented ten
study participants with either number symbols or dots while their brains were scanned with
fMRI. They then used a multivariate analysis method to devise a way of decoding the
numbers or number of dots people had observed. Although the brain patterns corresponding
to number symbols differed somewhat from those for the same number of objects, the
numerosity of dot sets can be predicted above chance from the brain activation patterns
evoked by digits, the researchers show. That doesn't work the other way around, however.
Researchers identify new brain
pathway for regulating weight and bone mass
Contrary to the prevailing view, the hormone leptin, which is critical for normal food
intake and metabolism, appears to regulate bone mass and suppress appetite by acting
mainly through serotonin pathways in the brain, according to a recent study published in
Cell by Yale School of Medicine researchers and colleagues at Columbia University. This
new finding contradicts the view that leptin acts primarily in the hypothalamus. "Our
study challenges the view that the hypothalamus is the critical brain site where leptin
acts directly to alter neuronal circuit function to suppress appetite and bone
metabolism," said Yale researcher and study co-author Tamas Horvath. "We've now
found a novel explanation for how leptin can act on the brain." Horvath is chair and
professor of comparative medicine and professor of neurobiology and obstetrics &
gynecology at Yale School of Medicine. Food intake is influenced by signals that travel
from the body to the brain. Leptin is one of the molecules that signal the brain to
modulate food intake. It is produced in fat cells and informs the brain of the metabolic
state. If animals are missing leptin, or the leptin receptor, they eat too much and become
severely obese. To determine whether leptin regulates bone mass through serotonin
pathways, Horvath and his colleagues analyzed multiple lines of mice that were genetically
altered to remove serotonin in the brain. "We found that when the serotonin pathway
is turned off by leptin, the mice ate less, lost weight and their bones became weak. When
the pathway is turned on, the mice ate more, gained weight and had more bone mass,"
said Horvath. "This might be why obese people tend to have much lower incidences of
osteoporosis." The study was designed by Gerard Karsenty of Columbia University as a
follow-up to his groundbreaking work on the relationship between leptin and bone
metabolism. Yale researchers provided a neurobiological framework for the study.
"This study modifies the map of leptin signaling in the brain and identifies a
molecular basis for the common regulation of bone and energy metabolisms," said
Horvath, who is also director of the recently established Program on Cell and Neurobiology
of Energy Metabolism at Yale.
Novel 'on-off switch' mechanism
stops cancer in its tracks
A tiny bit of genetic material with no previously known function may hold the key to
stopping the spread of cancer, researchers at Yale School of Medicine and Sichuan
University in Chengdu, China report in two papers in the September 7-11 issue of
Proceedings of the National Academy of Sciences. In the papers, Alan Garen of the
Department of Molecular Biophysics & Biochemistry at Yale and his colleague Xu Song
explain how cancer may overcome an organism's natural "stop sign" for cell
division. During early development, stem cells give rise to other cells that differentiate
into all types of tissue. New cell division and proliferation stop as the organism
matures. However, cancer can hijack this process and trigger the uncontrolled cell
division that produces cancer tumors. One mechanism that stops cell proliferation is a
family of tumor-suppressor proteins (TSP) that bind to and block the function of
proto-oncogenes, or genes that have the potential to trigger cancer. Garen's team working
with mice found that an RNA molecule from an area of the genome that does not produce
proteins prevents a type of TSP from inactivating these incipient cancer genes. The TSP
protein they studied, called PSF, is virtually identical in mice and humans, he said. The
Yale team succeeded in preventing the formation of tumors in mice by either increasing the
amount of PSF or decreasing the amount of the non-coding RNA in a cell.
Yale Researchers Explain Why Hunger
Triggers Infertility
Scientists have long known that calorie restriction increases longevity in animals but at
an evolutionary cost – the animals become infertile. Yale University researchers
report in the September 7 to 11 issue of the Proceedings of the National Academy of
Sciences that they have discovered the molecular switch in the brain that turns off the
reproductive system in times of severe hunger. The same molecule also may play a key role
in obesity, drug addiction and depression. The scientists found that a peptide active in
the hypothalamus called melanin-concentrating hormone or MCH can inactivate the
reproductive system in times of hunger. “Brain neurons that make MCH are quiet most
of the time, but when the body is in negative energy balance, MCH neurons become active
and can shut down reproduction, said Meenakshi Alreja, senior author the paper and
Associate Professor of Psychiatry and Neurobiology at the Yale School of Medicine. The
Yale team found that MCH prevents a key reproductive molecule called kisspeptin from
acting. Kisspeptin triggers puberty and helps maintain fertility. Hunger or excessive
exercise activates the MCH system and delays puberty by blocking kisspeptin.
New study finds way to stop
excessive bone growth following trauma or surgery
A recent United States Army study found that excessive bone growth, also known as
heterotopic ossificiation (HO), affects up to 70 percent of soldiers who are severely
wounded during combat. A much smaller percentage of the civilian population also suffers
from HO following trauma or invasive surgery. The excessive bone forms within muscles and
other tissues causing severe pain, reduced mobility and even local paralysis if untreated.
A new study by Thomas Jefferson University researchers found a way to prevent HO in animal
models by shutting the process off in its early stages. The study, reported in September's
Journal of Orthopaedic Research, is expected to lead to clinical trials and may hopefully
provide a new, effective and safe treatment for HO. "This is a major breakthrough in
HO research," said Primary Investigator Maurizio Pacifici, Ph.D, director of
Orthopedic Research at Jefferson Medical College of Thomas Jefferson University. "We
are able to largely prevent formation and progression of HO lesions. We presented our
initial results at a recent U.S. Army Extremity War Injuries Symposium in Washington D.C.
and they were very well-received and have elicited great hope on the part of military
physicians to finally have a way to stop HO in troops wounded in war zones." In the
ongoing study sponsored by the U.S. Army, Jefferson scientists were able to prevent HO by
disrupting a series of cellular changes that are needed to produce HO. Following a trauma
or invasive surgery, the condition begins when progenitor and stem cells are recruited to
the injured site and give rise to cartilage tissue that then turns to bone. This
multi-step process is regulated by several factors. One of these factors is a protein in
the nucleus of the progenitor cells that is called the retinoid alpha receptor. This
receptor must be turned off before the progenitor cells can form cartilage tissue. The
Jefferson scientists, using a pharmacological agent, an alpha agonist, kept the receptors
active, stifling the initiation of the disease in its tracks. "The agonist we used in
this case is an experimental drug that is not on the market yet, but is being tested in
Phase II human trials for another disease. We tested whether the drug could work to
prevent HO, thereby looking for another application for the drug," said Pacifici.
M. D. Anderson examines use of toad
venom in cancer treatment
Huachansu, a Chinese medicine that comes from the dried venom secreted by the skin glands
of toads, has tolerable toxicity levels, even at doses eight times those normally
administered, and may slow disease progression in some cancer patients, say researchers
from The University of Texas M. D. Anderson Cancer Center. The results from the Phase I
clinical study, a collaborative research project between M. D. Anderson and Fudan
University Cancer Hospital in Shanghai, are reported in the online Early View feature of
the journal Cancer. The study marks the first time a formal clinical trial has examined
the relationship between huachansu dose and toxicity, although the drug is common in China
and approved by the Chinese Food and Drug Administration. Huachansu is widely used to
treat patients with liver, lung, colon and pancreatic cancer at oncology clinics in China.
Chinese clinical trials conducted since the 1970s have demonstrated the anti-cancer
properties of huachansu, citing total response rates of 10 percent and 16 percent observed
in patients with advanced hepatocellular carcinoma and lung cancer, respectively1,2.
"Studying traditional Chinese medicine such as huachansu is new to American research
institutions, which have been skeptical and slow to adopt these complementary treatments.
However, it is important to understand its potential role in treating cancer," says
Lorenzo Cohen, Ph.D., one of the paper's authors and director of the Integrative Medicine
Program at M. D. Anderson. "We wanted to apply a Western medicine-based approach to
explore the role of the toad venom compound in cancer patients and test if it is possible
to deliver a more potent dose without raising toxicities or side effects."
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