News - Week 16 - 2009
Urgent: Support the Proposed New
Law in California Requiring Doctors to Provide Patients with Information on Diabetes and
Heart Disease
Patients often receive inadequate and/or
incorrect information from their doctors on diabetes and heart disease. Last months
newsletter was on the heart disease side of this bill. Concerning type-2 diabetes, health
professionals and pharmaceutical companies disseminate incorrect and inadequate
information on these four important issues:
1) Patients are told diabetic medications
for type-2 diabetes will prolong life and prevent complications of diabetes, while
extensive scientific research says otherwise for the most commonly prescribed oral
medications.
2) Patients are told that their blood
sugars (and hemoglobin A1c levels) must be lowered as close to normal levels as possible.
However, all six major studies show intensive therapy increases the risk of heart disease,
death, and serious side effects.
3) The public receives almost no education
about the role of the rich Western diet in the cause of type-2 diabetes and about the
right way to eat to prevent this disease.
4) Patients are rarely told that changing
to a healthy, low-fat, plant-food based diet, exercise, and associated weight loss will
improve their health and often cure their type-2 diabetes.
Assembly Bill 1478 has been introduced by
California state assembly member Tom Ammiano, representing the 13th District, to require
that a physician obtain a patient's written acknowledgment confirming the receipt of
information, as specified, regarding treatment through medical nutrition therapy prior to
delivering nonemergency treatment for type-2 diabetes. My supporting letter on this matter
is provided below. Last months newsletter (March 2009) has a similar letter from me
about heart disease treatments and a request for your support.
Read more
Researchers find promotion is bad
for mental health and stops you visiting the doctor
New research by economics and psychology
researchers at the University of Warwick has found that promotion on average produces 10%
more mental strain and gives up to 20% less time to visit the Doctors. In a research paper
entitled Do People Become Healthier after Being Promoted Chris Boyce and
Professor Andrew Oswald of the University of Warwick questioned why people with higher job
status seem to have better health. A long-held assumption by researchers is that an
imprvement to a persons job status, through a promotion, will directly result in
better health due to an increased sense of life control and self-worth.
The researchers tested this. They drew upon the British Household Panel Survey data set,
collected annually between 1991 and 2005, with information on approximately 1000
individual promotions. They found no evidence of improved physical health after promotion
nor that self-assessed feelings of health declined.
Genes from tiny marine algae
suggest unsuspected avenues for new research
By sequencing the DNA of two tiny marine
algae, a team of scientists has opened up a myriad of possibilities for new research in
algal physiology, plant biology, and marine ecology. The project was led by Alexandra
Worden at the Monterey Bay Aquarium Research Institute (MBARI) and the Joint Genome
Institute (JGI). The genome analyses involved a collaborative effort between MBARI, JGI,
and an international consortium of scientists from multiple institutions, including
University of Washington, Ghent University (Belgium), and Washington University in St.
Louis. Initial discoveries from the research appear in the April 10, 2009 edition of
Science magazine. Biologists generally agree that all land plants, from tiny mosses to
giant redwoods, evolved from an ancestral green alga. Some of the closest representatives
of these ancestral green algae living today are thought to be the Prasinophytes, a group
of microscopic green algae found across the world's oceans. Microbial oceanographer
Alexandra Worden led a team of scientists that sequenced the genomes of two Prasinophytes
in the genus Micromonas. Each Micromonas cell is only about one fiftieth the width of a
human hair. However, they are widespread and may serve as important links in marine food
webs. They may also influence the amount of carbon dioxide the oceans take up from the
atmosphere. Worden's team spent four years compiling a complete list of the approximately
21 million chemical building blocks (called bases) that make up Micromonas' DNA. The
recent Science paper highlights key aspects of this genetic "Morse code." The
paper also compares Micromonas' genes with genes found in other organisms.
Study finds multidrug-resistant
gram-negative bacteria high in long-term care
The prevalence of a certain form of
drug-resistant bacteria, called multidrug-resistant gram-negative (MDRGN) organisms, far
surpassed that of two other common antimicrobial-resistant infections in long-term care
facilities, according to a study conducted by researchers at Hebrew SeniorLife's Institute
for Aging Research. Residents at long-term care facilities are one of the main reservoirs
of antimicrobial-resistant bacteria. Epidemiological studies have focused primarily on two
common antimicrobial-resistant organismsmethicillin-resistant Staphylococcus aureas
(MRSA) and vancomycin-resistant enterococci (VRE).
"Recently, it has become apparent that multidrug resistance among gram-negative
bacteria is becoming an even greater problem in these facilities, with nearly half of
long-term care facility residents harboring multidrug-resistant gram-negative
bacteria," write the researchers, led by IFAR's Erin'O'Fallon, M.D., M.P.H., in the
January issue of the Journal of Gerontology: Medical Sciences. MDRGN infection can lead to
toxins in the bloodstream that cause inflammation and destroy healthy tissue. Left
untreated, these infections can be fatal. More than 80 percent of the MDRGN cases in the
study were resistant to commonly prescribed antimicrobial medications, including
ciprofloxacin, trimethoprim-sulfamethoxazole, and amipicillin/sulbactam. By definition all
of the identified MDRGN bacteria were resistant to at least three different classes of
antimicrobial drugs, with one-third of them resistant to four.
Test quickly assesses whether
Alzheimer's drugs are hitting their target
A test developed by physician-scientists at
Washington University School of Medicine in St. Louis may help assess more quickly the
ability of Alzheimer's drugs to affect one of the possible underlying causes of
Alzheimer's disease in humans, accelerating the development of new treatments. Scientists
used the test to show that an Alzheimer's drug given to healthy volunteers reduced
production of a substance known as amyloid beta (A-beta), a normal byproduct of human
metabolism that builds to unhealthy levels forming brain plaques in Alzheimer's patients.
The drug candidate, LY450139, which is also known as semagacestat, is being studied in
clinical trials by Eli Lilly and Company.Ongoing clinical trials are studying the effect
that semagacestat may have on cognitive function and biochemical and brain imaging
biomarkers in patients with Alzheimer's disease. Washington University researchers wanted
to see whether the new measurement technique, stable isotope-linked kinetics (SILK), could
detect the study drug's impact on A-beta synthesis in healthy volunteers. "Bringing
an Alzheimer's disease drug into clinical trials from tests in animal models has always
been challenging," says study director Randall Bateman, M.D., a Washington University
neurologist who treats patients at Barnes-Jewish Hospital. "We haven't had a way to
quickly and accurately assess a drug's effects, and that meant there always had to be some
degree of educated guesswork when it came to setting the optimal dosage for humans. SILK
may help to eliminate much of that guesswork."
Scientists show how a neuron gets
its shape
Ask a simple question, get a simple answer:
When Abraham Lincoln was asked how long a mans legs should be, he absurdly replied,
Long enough to reach the ground. Now, by using a new microscopy technique to
watch the growth of individual neurons in the microscopic roundworm Caenorhabditis
elegans, Rockefeller University researchers are turning another deceptively simple
question on its head. They asked, How long should a worms neurons be?
And the worms fired back, Long enough to reach their targets. The
researchers surprising result: Rather than growing like the branches of a tree
extending outward - certain neurons work backward from their destination, dropping
anchor and stretching their dendrites behind them as they crawl away. The work, led by
Shai Shaham, head of the Laboratory of Developmental Genetics, and Maxwell Heiman, a
research associate in the lab, not only addresses an age-old question of how neurons get
their shape, but is also changing the way scientists think about the genetic program that
wires the brain and allows it to grow throughout development.
Vitamin D Deficiency Related to
Increased Inflammation in Healthy Women, MU Study Finds
According to a recent study in the Archives
of Internal Medicine, 75 percent of Americans do not get enough Vitamin D. Researchers
have found that the deficiency may negatively impact immune function and cardiovascular
health and increase cancer risk. Now, a University of Missouri nutritional sciences
researcher has found that vitamin D deficiency is associated with inflammation, a negative
response of the immune system, in healthy women. Increased concentrations of serum
TNF-?, an inflammatory marker, were found in women who had insufficient vitamin D levels.
This study is the first to find an inverse relationship between vitamin D levels and
concentrations of TNF-? in a healthy, non-diseased population. This may explain the
vitamin's role in the prevention and treatment of inflammatory diseases, including heart
disease, multiple sclerosis and rheumatoid arthritis. "The findings reveal that low
vitamin D levels negatively impact inflammation and immune response, even in healthy
women," said Catherine Peterson, assistant professor in the MU College of Human
Environmental Sciences. "Increased inflammation normally is found in people with
obesity or chronic diseases; a small decrease in vitamin D levels may aggravate symptoms
in people who are sick."
How tumor cells move
Researchers in Heidelberg discover new
protein that is suppressed in particularly aggressive cancer cells / Article in Nature
Cell Biology. If cancer cells lack a certain protein, it could be much easier for them to
penetrate healthy body tissue, the first step towards forming metastases. Scientists at
the Pharmacology Institute of the University of Heidelberg have discovered the previously
unknown cell signal factor SCAI (suppressor of cancer cell invasion), which inhibits the
movement and spread of tumor cells in laboratory tests. When the factors functioning
was disrupted, the cancer cells moved much more effectively in what are known as
three-dimensional matrix systems, which imitate some of the tissue properties of the human
body. The protein is apparently suppressed in many types of tumors, e.g. breast,
lung, or thyroid, explains Dr. Robert Grosse, head of the Emmy Noether Junior
Research Group funded by the German Research Association (DFG) at the Pharmacology
Institute. The new factor could be an interesting starting point for research into new
mechanisms for fighting cancer. The research teams results have now been published
online in the prestigious international journal Nature Cell Biology.
Scientists identify key gene that
protects against leukemia
Researchers have identified a gene that
controls the rapid production and differentiation of the stem cells that produce all blood
cell typesa discovery that could eventually open the door to more streamlined
treatments for leukemia and other blood cancers, in which blood cells proliferate out of
control. Additionally, in investigating the mechanisms of this gene, the scientists
uncovered evidence that could lead to a protocol for bone marrow transplants that could
boost the chance of a cure in some patients. The research, led by Emmanuelle Passegué,
PhD, of the University of California, San Francisco, demonstrates that the JunB gene is at
the center of a complex network of molecular and environmental signals that regulate the
proliferation and differentiation of hematopoietic stem cells, the multipotent,
self-renewing cells that give rise to all blood cell types.
Human ES cells progress slowly in
myelin's direction
Scientists from the University of
Wisconsin, USA, report in the journal Development (dev.biologists.org) the successful
generation from human embryonic stem cells of a type of cell that can make myelin, a
finding that opens up new possibilities for both basic and clinical research. The
cells the researchers made are called oligodendrocytes, which are responsible for making
myelin in the central nervous system. Myelin forms an insulating sheath that surrounds
nerve fibres, both protecting them and speeding up the transmission of nerve impulses. Its
loss or damage has serious consequences, as is seen in the condition of multiple
sclerosis, because without it nerves lose the ability to transmit impulses to each other
and to function properly. Unlike human embryonic stem (ES) cells, it's relatively easy to
persuade mouse ES cells to turn into oligodendrocytes; it's often done by exposing these
cells to a protein called Sonic Hedgehog, which produces oligodendrocytes in the spinal
cord of developing embryos. Now Su-Chun Zhang and his co-workers show in the May issue of
Development (dev.biologists.org) that treating human ES cells with this same protein also
turns them into oligodendrocytes they just take longer to do it, 14 weeks as
opposed to the 2 weeks taken by mouse ES cells. They also report another difference
between mouse and human ES cells: a growth factor called Fgf2 that promotes
oligodendrocyte development in mouse ES cells actually stalls it in human ES cells. As Dr
Zhang reveals, these findings were quite unexpected. 'This was quite a surprise given that
this is exactly how we direct mouse ES cells to become oligodendrocytes. But we have
discovered an unexpected twist in the cell's response to the same external factor',
explained Dr Zhang. 'It nevertheless explains why so many research groups have failed to
persuade human neural stem cells to become oligodendrocytes for the past decade.' As Dr
Zhang went on to discuss, these findings are also of clinical importance. 'We are now able
to generate a relatively enriched population of oligodendrocyte precursor cells that may
be used to repair lost myelin sheaths. These findings also raise awareness of the direct
translatability of animal studies to human biology. In this regard, the human
oligodendrocytes generated from human ES cells or the generation of disease-induced
pluripotent stem cells can provide a useful tool in the future for screening
pharmaceuticals directly on human cells.'
Researcher uses GPS to find asthma
causes
David Van Sickle is looking for a few
pioneering asthmatics. He wants to attach a GPS device to their inhalers before they
boldly go out into a spring world filled with allergens.His goal is to map where and when
environmental exposures trigger asthma symptoms, prompting them to puff on their
rescue inhalers, which deliver the medicine that keeps them breathing.
Vitamin D may exacerbate autoimmune
disease
Deficiency in vitamin D has been widely
regarded as contributing to autoimmune disease, but a review appearing in Autoimmunity
Reviews explains that low levels of vitamin D in patients with autoimmune disease may be a
result rather than a cause of disease and that supplementing with vitamin D may actually
exacerbate autoimmune disease. Authored by a team of researchers at the California-based
non-profit Autoimmunity Research Foundation, the paper goes on to point out that molecular
biologists have long known that the form of vitamin D derived from food and supplements,
25-hydroxyvitamin D (25-D), is a secosteroid rather than a vitamin. Like corticosteroid
medications, vitamin D may provide short-term relief by lowering inflammation but may
exacerbate disease symptoms over the long-term. The insights are based on molecular
research showing that 25-D inactivates rather than activates its native receptor - the
Vitamin D nuclear receptor or VDR. Once associated solely with calcium metabolism, the VDR
is now known to transcribe at least 913 genes and largely control the innate immune
response by expressing the bulk of the body's antimicrobial peptides, natural
antimicrobials that target bacteria. Written under the guidance of professor Trevor
Marshall of Murdoch University, Western Australia, the paper contends that 25-D's actions
must be considered in light of recent research on the Human Microbiome. Such research
shows that bacteria are far more pervasive than previously thought 90% of cells in
the body are estimated to be non-human increasing the likelihood that autoimmune
diseases are caused by persistent pathogens, many of which have yet to be named or have
their DNA characterized. Marshall and team explain that by deactivating the VDR and
subsequently the immune response, 25-D lowers the inflammation caused by many of these
bacteria but allows them to spread more easily in the long-run. They outline how long-term
harm caused by high levels of 25-D has been missed because the bacteria implicated in
autoimmune disease grow very slowly. For example, a higher incidence in brain lesions,
allergies, and atopy in response to vitamin D supplementation have been noted only after
decades of supplementation with the secosteroid. Furthermore, low levels of 25-D are
frequently noted in patients with autoimmune disease, leading to a current consensus that
a deficiency of the secosteroid may contribute to the autoimmune disease process. However,
Marshall and team explain that these low levels of 25-D are a result, rather than a cause,
of the disease process. Indeed, Marshall's research shows that in autoimmune disease, 25-D
levels are naturally down-regulated in response to VDR dysregulation by chronic pathogens.
Under such circumstances, supplementation with extra vitamin D is not only
counterproductive but harmful, as it slows the ability of the immune system to deal with
such bacteria. The team points out the importance of examining alternate models of vitamin
D metabolism. "Vitamin D is currently being recommended at historically unprecedented
doses," states Amy Proal, one of the paper's co-authors. "Yet at the same time,
the rate of nearly every autoimmune disease continues to escalate."
Acupuncture wristbands Ease Nausea
with Cancer Treatment
Cancer patients who wore acupressure
wristbands had much less nausea while receiving radiation treatment, making the bands a
safe, low-cost addition to anti-nausea medication, according to a study in the Journal of
Pain and Symptom Management by University of Rochester Medical Center researchers.
Previous research has suggested that the placebo effect essentially, an outcome
related to your body that you expect to happen might be why elastic wristbands
reduce nausea. However, the findings of the latest study do not support that notion, even
though researchers continue to believe in the minds powerful influence over
symptoms. We know the placebo effect exists, the problem is that we dont know
how to measure it very well, said Joseph A. Roscoe, Ph.D., corresponding author and
research associate professor at the James P. Wilmot Cancer Center at URMC. In this
study we attempted to manipulate the information we gave to patients, to see if their
expectations about nausea could be changed. As it turned out, our information to change
peoples expectations had no effect but we still found that the wristbands
reduce nausea symptoms. The clinical trial enrolled 88 people divided into three
groups. All had reported some degree of nausea after receiving at least two radiation
treatments for any type of cancer. Although chemotherapy is more closely linked with
producing nausea and vomiting, radiation to the intestinal tract can also cause nausea,
Roscoe said.
Gene therapy appears safe to
regenerate gum tissue
Scientists at the University of Michigan
have developed a method of gene delivery that appears safe for regenerating
tooth-supporting gum tissuea discovery that assuages one of the biggest safety
concerns surrounding gene therapy research and tissue engineering.Gene therapy is an
accepted, viable therapeutic concept, but safety is a major hurdle, said William
Giannobile, professor at the U-M School of Dentistry. The most notable incident
highlighting the safety concerns of gene therapy research and treatment occurred several
years ago when a teenager died when given the adenovirus during a gene therapy clinical
trial at the University of Pennsylvania. The U-M therapy also uses the adenovirus,
Giannobile said, but the big difference in the U-M approach lies in the local application
and much lower dose. Instead of injecting the genes into the blood vessels, where they can
then travel through the bloodstream and result in unexpected and sometimes fatal
reactions, U-M scientists put the genes on a localized area, directly on the tissue during
surgery much like a paste.
Phasic firing of dopamine neurons
is key to brain's prediction of rewards
Researchers are one step closer to
understanding the neurobiology that allows people to successfully learn motivated
behaviors by associating environmental cues with rewarding outcomes, according to a study
published yesterday in the Proceedings of the National Academy of Sciences' online Early
Edition. Carlos Paladini, assistant professor of neuroscience at The University of Texas
at San Antonio (UTSA) and UTSA graduate student Collin Lobb collaborated with researchers
at The University of Washington at Seattle to study the firing patterns of midbrain
dopamine neurons in mice during reward-based learning. "Our research findings provide
a direct functional link between the bursting activity of midbrain dopamine neurons and
behavior. The research has significant applications for the improvement of health, because
the dopamine neurons we are studying are the same neurons that become inactivated during
Parkinson's Disease and with the consumption of psychostimulants such as cocaine and
amphetamine," said Paladini, who is also a member of UTSA's Neurosciences Institute.
Midbrain dopamine neurons fire in two characteristic modes, tonic and phasic, which are
thought to modulate distinct aspects of behavior. When an unexpected reward is presented
to an individual, midbrain dopamine neurons fire high frequency bursts of electrical
activity. Those bursts of activity allow us to learn to associate the reward with cues in
our environment, which may predict similar rewards in the future. The burst of electrical
spikes observed in dopamine neurons is facilitated by a protein called the NMDA receptor,
which is expressed on the surface of the dopamine cells. In this study, researchers
removed the NMDA receptor from the dopamine cells only, leaving the dopamine neurons
unable to fire bursts. The cells would otherwise fire normally.
Is there a prospective association
between obesity and periodontal disease?
This is the question asked by a team of
investigators from the Harvard School of Public Health and the University of Puerto Rico,
reporting their findings today during the 87th General Session of the International
Association for Dental Research, convening at the Miami Beach Convention Center. The
investigators evaluated the association between different measures of obesity and risk of
periodontal disease. They analyzed data from 36,903 men from the Health Professionals
Follow-Up Study who were free of reported periodontal disease at the start of follow-up,
and we followed them for up to 16 years (1986-2002). Height was assessed at the start of
follow-up, and weight and self-reported periodontal disease data were collected at
baseline and on follow-up questionnaires mailed every two years. Measures of central
obesity were made by waist and hip circumference through self-assessed measurements and
reported in 1987 with the aid of printed instructions and a tape measure. Self-reported
periodontal disease and adiposity measures had been previously validated. They evaluated
the effect of body mass index (BMI kg/m2), waist circumference (WC), and waist-to-hip
ratio (WHR), on first report of periodontal disease diagnosis. The team observed
significant associations between all measures of obesity and periodontal disease when
accounting for age, smoking, race, dental profession, physical activity, fruit and
vegetable intake, and diabetes status at baseline. Obesity (BMI > 30 kg/m¬2) at the
beginning of follow-up and over follow-up was significantly associated with a 25% and 29%
increased risk compared with normal weight (BMI 18.5-24.9 kg/m2), respectively. Men with
WC > = 40 inches compared with < 40 inches was significantly associated with a 19%
increased risk of periodontal disease, compared with men with a WC < 40 inches. WHR
> = 0.95 compared with < 0.95 exhibited a significant 16% increased risk of
periodontal disease. When BMI was accounted for (i.e., overall obesity), the effects of WC
and WHR (i.e., central obesity) were weakened. The associations of BMI and WC were
significant even among non-diabetics and among those who had never smoked. These results
provide the first evidence following a large group of people over time with clear evidence
of obesity occurring prior to periodontal disease, and support an association between
obesity and risk of periodontal disease. Given the high prevalence of obesity and
periodontal disease, this association may be of substantial public health importance.
Resolvins have the potential to
resolve periodontal inflammation and restore tissue health
Periodontal (gum) disease is a chronic
inflammation initiated by bacteria that affect the gums and bone supporting the teeth, and
may eventually result in tissue and tooth loss. It is similar to other chronic
inflammatory diseases such as arthritis, where inflammation causes tissue damage and is
responsible for the disease. To date, the prevention of gum disease has been limited to
successful oral hygiene and regular professional care. However, despite these preventive
actions, in susceptible individuals with a high inflammatory response, plaque control is
not enough to prevent disease. Today, during the 87th General Session of the International
Association for Dental Research, scientists from Boston University are reporting on the
discovery of Resolvins, a new family of biologically active products of omega-3 fatty
acids with the therapeutic potential to resolve periodontal inflammation and restore the
gums to health. Oil from fish contains eicosapentaenoic acid (EPA) and docosahexaenoic
acid (DHA); both are omega-3 fatty acids. These omega-3 fatty acids keep blood
triglycerides in control and may inhibit the progression of atherosclerosis. EPA and DHA
also have anti-inflammatory activity and are often used to help people with various
inflammatory conditions, such as Crohn's disease and rheumatoid arthritis. The Resolvins
are natural endogenous regulators of the immune system against inflammation. Compounds
derived from EPA are designated Resolvins of the E series (RvE1), and those biosynthesized
from DHA are denoted Resolvins of the D series (RvD). The investigators have previously
shown that topical application of RvE1 in experimental gum disease provided protection
against soft tissue and bone loss associated with gum disease and, remarkably, restored
the lost soft tissue and bone to healthy levels. Since, in recent studies, DHA-derived
Resolvin D1 (RvD1) was shown to provide protection against tissue damage in several
systemic inflammation models, the Boston team conducted experiments to test the actions of
RvD1 in regulating tissue destruction and resolution of inflammation in gum disease.
Experimental gum disease characterized by tissue inflammation and bone loss was stimulated
in rabbits by the application of specific bacteria that cause human gum disease. The
results demonstrate that RVD1 is similar to the EPA-derived lipid mediator, RvE1, in
resolving periodontal inflammation and tissue regeneration. These results support the
hypothesis that both EPA- and DHA-derived Resolvins have therapeutic potential in
resolving periodontal inflammation and restoring the tissues' health.
Study finds new evidence of
periodontal disease leading to gestational diabetes
A new study by NYU dental researchers has
uncovered evidence that pregnant women with periodontal (gum) disease face an increased
risk of developing gestational diabetes even if they don't smoke or drink, a finding that
underscores how important it is for all expectant mothers even those without other
risk factors to maintain good oral health.The study, led by Dr. Ananda P.
Dasanayake, Professor of Epidemiology & Health Promotion at New York University
College of Dentistry in collaboration with the Faculty of Dental Sciences at the
University of Peradeniya, Sri Lanka, eliminated smoking and alcohol use among a group of
190 pregnant women in the South Asian island nation of Sri Lanka, where a combination of
cultural taboos and poverty deter the majority of women from smoking and drinking. The
findings support an earlier study led by Dr. Dasanayake that found evidence that pregnant
women with periodontal disease are more likely to develop gestational diabetes than
pregnant women with healthy gums. That study, which followed 256 women at New York's
Bellevue Hospital Center through their first six months of pregnancy, showed that 22 of
the women developed gestational diabetes. Those women had significantly higher levels of
periodontal bacteria and inflammation than the other women in the study. The findings were
published in the April 2008 issue of the Journal of Dental Research. More than one-third
of the women in the new study, which was conducted over the course of one year, reported
having bleeding gums when they brushed their teeth. The women were given a dental
examination and a glucose challenge test, which is used specifically to screen for
gestational diabetes. According to Dr. Dasanayake, those women found to have the greatest
amount of bleeding in their gums also had the highest levels of glucose in their blood.
Dr. Dasanayake, who presented the findings today at the annual meeting of the
International Association for Dental Research in Miami, said that he expected the final
data to show that between 20 and 30 of the women had developed gestational diabetes.
Big belly and obesity linked to
increased risk of restless legs syndrome
A new study shows both obesity and a large
belly appear to increase the risk of developing restless legs syndrome (RLS), a common
sleep disorder characterized by an irresistible urge to move your legs. The research is
published in the April 7, 2009, print issue of Neurology®, the medical journal of the
American Academy of Neurology. It is estimated that 5-10 percent of adults in the United
States have RLS and the disorder often has a substantial impact on sleep, daily activities
and quality of life. For the study, researchers questioned 65,554 women and 23,119 men,
all of whom were health professionals who took part in the Health Professionals Follow-Up
Study or the Nurses' Health Study II. None of the participants had diabetes, arthritis or
were pregnant. Of the groups, 6.4 percent of the women and 4.1 percent of the men were
identified as having RLS. The research found men and women with a body mass index (BMI)
score over 30 were nearly one-and-a-half times more likely to have RLS than people who
were not obese. In addition, people who were in the top 20 percent of the group for
highest waist circumference were more than one-and-a-half times more likely to have RLS
than the bottom 20 percent of the group with the lowest belly size. The results were the
same regardless of age, smoking, use of antidepressants or anxiety. "These results
may be important since obesity is a modifiable risk factor that is becoming increasingly
common in the U.S.," said study author Xiang Gao, MD, PhD, with the Harvard School of
Public Health in Boston. "More research is needed to confirm whether obesity causes
RLS and whether keeping a low BMI score and small waist size could help prevent RLS."
Gao says some studies suggest that obese people have lower dopamine receptor levels in the
brain. "Since decreased dopamine function is believed to play a critical role in RLS
as well, this could be the link between the two." Dopamine is a chemical naturally
produced by the body that transmits signals between nerve cells.
Gene helps protect tumor suppressor
in breast cancer
Scientists at The University of Texas M. D.
Anderson Cancer Center have discovered a gene that protects PTEN, a major tumor-suppressor
that is reduced but rarely mutated in about half of all breast cancers. The gene Rak helps
protect and regulate PTEN, which also is important in several other types of cancer, the
team reports in the April edition of Cancer Cell. Causes for diminished PTEN protein
levels in breast cancer absent a mutation of the PTEN gene have eluded researchers, who
knew for several years that a piece of the puzzle was missing. "We've clearly
discovered the missing link that explains how Rak can stabilize PTEN protein to prevent
breast cancer development," said lead author Shiaw-Yih Lin, Ph.D., an assistant
professor in the Department of Systems Biology at M. D. Anderson. "Our research
explains why PTEN is defective in breast cancer and provides important clues for the
development of effective therapy in Rak- or PTEN-defective breast cancers." In
addition to breast cancer, PTEN frequently is mutated or inactivated in glioblastoma,
melanoma, and cancers of the prostate and endometrium. The severity of PTEN irregularities
strongly correlates with the tumor stage and grade. For example, complete loss of PTEN
expression is found more frequently in metastatic cancer than in primary tumors. In the
laboratory, researchers found Rak can stabilize PTEN protein and function as a tumor
suppressor gene to prevent breast cancer development.
M. D. Anderson Study Finds
Pre-Surgical Stress Management Improves Mood, Quality of Life for Prostate Cancer Patients
Brief stress management sessions prior to
and immediately after surgery may have both short- and long-term benefit for men
undergoing a radical prostatectomy for early-stage prostate cancer, according to research
from The University of Texas M. D. Anderson Cancer Center. The study, in the current issue
of the Journal of Clinical Oncology, is the first to examine the benefits of psychosocial
intervention for prostate cancer patients prior to surgery. It found that men who
participated in the sessions experienced less short-term mood disturbance and better
long-term quality of life, compared to patients who had the procedure but did not have any
behavioral intervention. Most psychosocial interventions in cancer of any type have been
studied after patients have completed surgery, explained Lorenzo Cohen, Ph.D., the study's
senior author and professor in M. D. Anderson's Departments of Behavioral Science and
General Oncology, and director of the Integrative Medicine Program. "We know that for
men with early-stage prostate cancer, the time when they are making treatment decisions is
very stressful," said Cohen. "A radical prostatectomy is not without possible,
very personal, consequences, including urinary incontinence and erectile dysfunction.
Patients may also be worried about the uncertainty that the surgery will cure their
cancer. "From other areas of research, we know that going into a surgical setting
overly stressed may increase a patient's recovery time. With this study, we wanted to
intervene in the pre- and post-surgical setting and try to help relieve stress and
minimize mood disturbance, such as depression, anxiety and distress, both in the short-
and long-term."
For the randomized study, 159 early stage prostate cancer, radical prostatectomy patients
were assigned to receive either: two 60-90 minute sessions of pre-surgical stress
management intervention and brief booster sessions the morning of, and 48 hours following
surgery; two 60-90 minute individual supportive attention sessions and boosters similar to
the stress management group; or standard care. Assessments occurred before the sessions,
one month before, one week before, and the morning of surgery, as well as six weeks, six
and 12 months following surgery.
Is There a Seat of Wisdom in the
Brain?
Researchers at the University of
California, San Diego School of Medicine have compiled the first-ever review of the
neurobiology of wisdom once the sole province of religion and philosophy. The study
by Dilip V. Jeste, MD, and Thomas W. Meeks, MD, of UC San Diegos Department of
Psychiatry and the Stein Institute for Research on Aging, will be published in the
Archives of General Psychiatry on April 6. Defining wisdom is rather subjective,
though there are many similarities in definition across time and cultures, said
Jeste, who is the Estelle and Edgar Levi Chair in Aging, professor of psychiatry and
neuroscience and chief of geriatric psychiatry at UC San Diego. However, our
research suggests that there may be a basis in neurobiology for wisdoms most
universal traits. Wisdom has been defined over centuries and civilizations to
encompass numerous psychological traits. Components of wisdom are commonly agreed to
include such attributes as empathy, compassion or altruism, emotional stability,
self-understanding, and pro-social attitudes, including a tolerance for others
values. But questions remain: is wisdom universal, or culturally based? said
Jeste. Is it uniquely human, related to age? Is it dependent on experience or can
wisdom be taught?
Substituting water for
sugar-sweetened beverages can reduce excess calorie consumption
eplacing consumption of sugar-sweetened
beverages (SSBs) with water could eliminate an average of 235 excess calories per day
among children and adolescents, according to a study published in the April 2009 Archives
of Pediatrics & Adolescent Medicine. The study's authors conclude that such a
replacement would be a simple and effective way to reduce excess intake of calories
causing childhood overweight and obesity, as well as address dental cavities and other
health problems associated with added sugar. And they predict no detrimental effects on
nutrition. "The evidence is now clear that replacing these 'liquid calories' with
calorie-free beverage alternatives both at home and in schools represents a key strategy
to eliminate excess calories and prevent childhood obesity," said Y. Claire Wang, MD,
ScD, assistant professor of Health Policy and Management at Columbia University Mailman
School of Public Health and the study's lead author. Dr. Wang and colleagues analyzed what
children and teens reported they ate and drank on two different days, using nationally
representative data from the 2003-2004 National Health and Nutrition Examination Survey.
They then estimated the impact of substituting water for SSBs on the total energy intake
of youths ages two to 19. No data suggest that youths increase their consumption of other
foods and beverages to compensate for drinking fewer SSBs, and so every can of soda or
fruit drink that is replaced by water means a net reduction of calories. Almost 90 percent
of U.S. children and adolescents currently consume SSBs on any given day, including soda,
fruit drinks, punches, sports drinks and sweetened tea, and the calories contained in
these drinks can represent more than 10 percent of their total daily intake. There is
growing evidence that sugar-sweetened beverage consumption is an important contributor to
rising youth obesity rates in the United States.
New technique invented to reveal
pancreatic stem cells
Just like those absconders chased by police
all over the world, everybody can tell about their good deeds but none really knows how to
recognize them. Yet, as of today, thanks to a study just published in the Proceedings of
the National Accademy of Sciences (PNAS) and authored by Nobel Laureate for Medicine in
2007 Mario Capecchi and by the researcher from the Catholic University of Rome Eugenio
Sangiorgi, we now know how to reveal the stem cells camouflaged in the pancreas.A stem
cell is a cell capable of generating all the other cells constituting the same tissue
(sometimes also called "adult stem cell"). "Reading the newspapers
sometimes one would doubt it says Sangiorgi but we don't know many things
about stem cells. It might look odd, but for instance we don't have a method to
distinguish a priori between a stem cell and any other cell in the same tissue. We can
only infer that a cell really is a stem cell by observing its behaviour". In other
words, when a researcher encounters a tissue, it's not immediately possible to identify
with certainty and thus isolate a stem cell. In some case, like in the meadows, we now
know where they are located and how to single them out and hence we have been
capable of successful life saving transplants for many years. But in the case of the
pancreas, as in that of many other tissues, until some years ago we doubted that these
special cells were even present there. "Together with Professor Capecchi, we had
already designed in the past a novel way to mark the stem cells in a tissue: a sort of
little flag, capable of helping us to effectively label the cells we were looking
for", explains Sangiorgi. In order to achieve this, Capecchi and Sangiorgi used a
molecular switch, that is a piece of DNA, which activates itself once the mouse under
scrutiny takes a special drug. When the switch is "on", a special fluorescent
protein is produced (and, as a matter of fact, the study about this type of proteins won
the Nobel Prize in Chemistry last October). The luminous cells are indeed the long-sought
stem cells. "In order to understand that these are really stem cells, we need only to
wait", comments Sangiorgi. "A normal cell is sooner or later destined to die. A
stem cell, instead, retains its capacity to renew itself and replicate. Thus, if we can
still observe, many months later, that a cell is still alive, that means it is indeed a
stem cell or a cell derived directly from the division of a stem cell". In the
newly published article, Sangiorgi and Capecchi have shown with their technique that a
particular subset of the pancreatic cells, the so-called acinar cells, are indeed stem
cells. The truly interesting aspect of their results is that these cells also produce
important digestive enzymes.
Premature ejaculation spray enables
men to last 6 times longer after penetration
Men with premature ejaculation who used a
topical spray five minutes before intercourse were able to delay their orgasm six times
longer than normal, according to a study in the April issue of BJU International. Three
hundred men with clinically diagnosed lifelong premature ejaculation (PE) from 31 centres
in the UK, Czech Republic, Hungary and Poland, were randomised into two groups. Two
hundred used the PSD502 spray, which contains 7.5mg of lidocaine and 2.5mg of prilocaine,
and 100 used a placebo spray with no active ingredients. Every time they had intercourse
during the three-month study period, each couple measured the time from vaginal
penetration to ejaculation with a stopwatch. The men were asked to abstain from sexual
activity or masturbation for 24 hours before each recorded encounter. The time from
penetration to ejaculation increased from an average of 0.6 minutes to 3.8 minutes in the
medicated group and to just 1.1 minutes in the placebo group. When these figures were
adjusted to take account of any variations between the two groups, these showed that the
treatment group were able to last 6.3 times longer after penetration when they used the
spray. The placebo group lasted 1.7 times longer.
New risk variant for atopic
dermatitis identified
Scientists of the Max Delbrück Center for
Molecular Medicine (MDC) Berlin-Buch and Charité University Medical School,
Berlin, Germany, in collaboration with researchers from the Klinikum rechts der Isar of
Technical University Munich and Christian Albrecht University, Kiel, have identified a
gene variant on chromosome 11 that is associated with an increased risk of atopic
dermatitis. In a large genome-wide association study the researchers scanned the genomes
of more than 9600 participants from Germany, Poland and the Czech Republic. "Our
findings cast new light on the pathogenesis of the disease," said Professor Young-Ae
Lee (Charité / MDC). The pediatrician-researcher and her collaborators hope the study
will lead to a new approach to targeted therapy for this chronic skin disorder. (Nature
Genetics doi: 10.1038/ng.347)*. More and more people suffer from atopic dermatitis, which
is also known as atopic or infantile eczema. Atopic dermatitis is a chronic (long-lasting)
inflammatory skin disease that typically affects the large flexures such as the bend of
the elbows or the back of the knees. Patients suffer from recurrent flares of intense
itching, dryness and redness of the skin, with weeping of clear fluid in the acute stage,
and skin thickening (lichenification) in the chronic stage. Along with hay fever and
asthma, atopic dermatitis is one of the most common allergic disorders. In the
industrialized countries about 15 percent of young children are affected. Atopic
dermatitis is typically the first clinical manifestation of allergic disease. In most
cases atopic dermatitis appears within the first few years of life. For the majority of
affected children this marks the beginning of an "allergic career", which in
later years evolves into hay fever or asthma. Just what triggers the outbreak of atopic
dermatitis is not yet fully understood. However, epidemiological studies indicate that the
genetic contribution is substantial. For that reason, of the total of 9600 study
participants, the scientists decided to scrutinize the genomes of 3011 individuals more
closely. These included children and adults with atopic dermatitis, healthy controls, as
well as entire families in which at least two children have atopic dermatitis. The
researchers scanned the entire genome, searching for genetic variants that are especially
common in atopic dermatitis patients. The study demonstrates that several genes are
involved in the pathogenesis of atopic dermatitis. Most importantly, the researchers
identified a variant on chromosome 11 that is particularly common in the patients with
atopic dermatitis. This variant is located in a region containing the gene C11orf30 which
encodes the protein EMSY. The scientists suspect that a mutation in this gene is
associated with atopic dermatitis. However, the exact role of EMSY in atopic dermatitis
still needs to be investigated.
Young adults at future risk of
Alzheimer's have different brain activity, says study
Young adults with a genetic variant that
raises their risk of developing Alzheimer's Disease show changes in their brain activity
decades before any symptoms might arise, according to a new brain imaging study by
scientists from the University of Oxford and Imperial College London. The results may
support the idea that the brain's memory function may gradually wear itself out in those
who go on to develop Alzheimer's.
The research, published today in the journal Proceedings of the National Academy of
Sciences, provides clues as to why certain people develop Alzheimer's Disease (AD) and it
may be a step towards a diagnostic test that identifies individuals at risk. The
degenerative condition is the most common cause of dementia and it affects around 417,000
people in the UK. The APOE4 genetic variant is found in about a quarter of the population.
Not everyone who carries the variant will go on to develop AD, but people who inherit one
copy of APOE4 have up to four times the normal risk of developing the late-onset variety
of the disease. People who have two copies have around ten times the normal risk. The
researchers behind today's study stress that most carriers of APOE4 will not go on to
develop Alzheimer's and carriers should not be alarmed by the study's findings.
Stem cell therapy grows new blood
vessels
Research led by David Hess of the Robarts
Research Institute at The University of Western Ontario has identified how to use selected
stem cells from bone marrow to grow new blood vessels to treat diseases such as peripheral
artery disease. It's one of the severe complications often faced by people who've had
diabetes for a long time. Reduced blood flow (ischemia) in their limbs can lead to resting
pain, trouble with wound healing and in severe cases, amputation. The research is
published in Blood. Hess drew human bone marrow and simultaneously isolated three
different types of stem cells that co-ordinate together to form new blood vessels. These
are called pro-angiogenic stem cells. They were purified to remove any inflammatory or
contaminated cells, and then injected into the circulation of mice which had one of their
leg arteries ligated and removed. The researchers showed how these stem cells have a
natural ability to hone in on the area of ischemia to induce blood vessel repair and
improve blood flow. Hess says this research is clinically-applicable because they studied
the function of human stem cells in immune-deficient mice. The preclinical data from
Hess research was used by a biopharmaceutical company, Aldagen (www.aldagen.com) to
receive FDA clearance for a multi-center clinical trial involving 21 patients with
end-stage peripheral artery disease. The clinical study has been successfully completed,
and the group of treated patients experienced improvements in overall clinical status as
well as increased blood flow in the affected limb. Aldagen has also successfully completed
a 20 patient study using these pro-angiogenic stem cells in patients with end-stage
ischemic heart failure. "We can select the right stem cells from the patient's own
bone marrow and put them back in the area of ischemia to allow these cells to coordinate
the formation of new blood vessels." says Hess, a professor in physiology and
pharmacology at Western's Schulich School of Medicine & Dentistry. "These
principles could be applied not only to ischemic limbs, but to aid in the formation of new
blood vessels in ischemic tissue anywhere in the body, for example after a stroke or heart
attack."
Link between widely used
osteoporosis drugs and heart problems probed
New research at Wake Forest University
School of Medicine evaluated the link between a common class of drugs used to prevent bone
fractures in osteoporosis patients and the development of irregular heartbeat. The study's
findings appear in the current issue of Drug Safety, a publication of the International
Society of Pharmacovigilance covering the safe and proper use of medicines. "Some
trials show there could be a potential link between the use of bisphosphonates and the
development of serious heart rhythm problems, but in our study the link wasn't
conclusive," said Sonal Singh, M.D., M.P.H., an assistant professor of internal
medicine and lead investigator for the study. "So we urge that additional
investigations be conducted." Bisphosphonates, found in prescription drugs including
BonivaTM, FosomaxTM, ReclastTM and ActonelTM, inhibit the breakdown of bones, which
reduces the risk of fractures, especially those of the spine and hips in older patients.
The first such drugs were approved for use in the mid-1990s.
Early studies indicated that the use of bisphosphonates might cause problems with heart
rhythm, or atrial fibrillation, which increases the risk for stroke or heart attack. For
the study published this month, researchers analyzed the data from previous observational
studies and clinical trials to determine the link between bisphosphonate therapy and
irregular heart beat. Researchers found that bisphosphonate use was associated with a
significant increase in the incidence of "serious" heart rhythm disturbances,
classified by hospitalization, disability or death resulting from the condition. However,
when they included "non-serious" cases in their analysis, they found no overall
increased risk of atrial fibrillation, the study shows."Our findings were discordant,
with conflicting results," Singh said. "The challenge now is to figure out what
it all means."
Fat-derived inflammatory factor may
explain diseases that come with obesity
An inflammatory factor already linked to
several diseases, including pulmonary disease, lung cancer, and arthritis, may also be
responsible for the insulin resistance that comes with obesity, according to a new study
published in the April issue of Cell Metabolism, a Cell Press publication. Researchers
have found that the inflammatory chemokine known as CXCL5 rises and falls with obesity and
subsequent weight loss in humans. (Chemokines are structurally related signaling proteins
that are secreted by cells.) They found further evidence tying the inflammatory factor,
which is produced and secreted at high levels by fat tissue, to insulin resistance in
mice. What's more, they show that treatments designed to block its action improves the
animals' sensitivity to insulin. "Clearly, this finding could be a big development
for understanding the side effects of obesity," said Lluis Fajas of INSERM in France.
"It offers a new target for therapy and new hope for subjects to improve their
pathology." Fat tissue known as white adipose tissue (WAT) is primarily involved in
energy storage in the form of triglycerides and energy release in the form of free fatty
acids, Fajas' team explained. However, WAT is more than a fat storage organ; it also
secretes numerous other factors with roles in both health and disease. In the new study,
the researchers show that CXCL5 is one of those factors. The chemokine is expressed at
high levels in WAT, particularly in immune cells known as macrophages. Moreover, they
report that CXCL5 is dramatically increased in the blood of people who are obese compared
to those who are lean. Those CXCL5 levels drop when obese people lose weight and are also
lower in obese individuals that continue to respond to insulin than in those who are
insulin resistant. They further found that treatment with recombinant CXCL5 blocks
insulin-stimulated glucose uptake in the muscles of mice. What's more, treatment of obese,
insulin-resistant mice with either anti-CXCL5 neutralizing antibodies or drugs that block
the receptor it triggers (known as CXCR2) reverses those symptoms. Mice lacking the CXCL5
receptor are also protected against obesity-induced insulin resistance. Overall, the
findings show that CXCL5 produced by fat tissue "represents a link between obesity,
inflammation, and insulin resistance." Interestingly, they added, the CXCR2 receptor
is active outside of muscle, in cells that line blood vessel walls and in the lung and
intestine, for example. Therefore, increased CXCL5 circulating levels as observed in
obesity could lead to other problems, including atherosclerosis and other inflammatory
diseases."Studies aiming to elucidate the role of WAT-secreted CXCL5 in all these
obesity-related pathologies are likely to be forthcoming in the near future," they
wrote. "Inhibiting CXCL5 secretion or function in obese individuals may not only
ameliorate their insulin sensitivity, but could also decrease the risk of developing other
major obesity-related pathologies."
Too much protein, eaten along with
fat, may lead to insulin resistance
A clue about the blood chemistry of obese
people who develop insulin resistance, a precursor to diabetes, has been confirmed in
animal studies at the Duke University Medical Center. Obese people have been found to
harbor proteins called branched-chain amino acids (BCAAs) at far higher levels than
non-obese people. The suspicion has been that these amino acids, in combination with a
high-fat diet, contribute to inulin resistance. The team found that the BCAA signature in
obese humans consisted of the branched-chain amino acids themselves, plus a cluster of
several products related to the body's breakdown processes for BCAA. "In the case of
the amino acids, we also are finding increased levels of their metabolic breakdown
products, which suggests the whole system for handling the amino acid metabolic process
has been overloaded," said senior author Christopher Newgard, Ph.D., director of the
Sarah W. Stedman Nutrition and Metabolism Center and W. David and Sarah W. Stedman
Distinguished Professor at Duke. "Our rat studies show that this overload causes
changes at the cellular level that can lead to insulin resistance." To determine
whether the BCAA signature in obese humans might signal that their intake is harmful, the
scientists performed a feeding study in rats that showed an independent contribution of
BCAAs to insulin resistance. "These findings, however, would need to be confirmed in
studies with people before any dietary recommendations could be issued," said Laura
Svetkey, M.D., director of the Duke Hypertension Center, director of clinical research at
the Sarah W. Stedman Nutrition and Metabolism Center, and co-senior author of the study,
published in Cell Metabolism. "Insulin resistance occurred in animals with a diet
high in the branched-chain amino acids, but only if they were ingested along with a high
level of fat in the diet," Newgard said. Because obese humans tend to ingest high-fat
diets, the combination of high-BCAA and high-fat intake might contribute to insulin
resistance in obese humans, but additional studies are needed. BCAAs comprise as much as
25 percent of amino acids in dietary protein, and are particularly enriched in diets high
in animal (meat) proteins. "I want to be clear that our animal data suggest that
there is nothing wrong with obtaining protein from sources that are high in branched-chain
amino acids, as long as you are not eating beyond what your energy needs are," said
Newgard, who is a professor of pharmacology and cancer biology and professor of medicine
at Duke. "If you add a lot of unneeded protein to a fatty diet, perhaps that's where
you get into problems. The ancient Greeks were right: everything in moderation."
Insulin resistance happens when insulin, released by the beta cells in the pancreas,
doesn't work normally to stimulate glucose uptake into tissues. Rats on a high-fat diet
gained substantially more weight than rats that ate BCAAs with high-fat chow or those that
ate standard chow. However, the rats eating the high-fat diet with BCAA became as insulin
resistant as rats fed a high-fat only diet, even though they weren't eating as much.
Joslin study pinpoints role of
insulin on glucagon levels
Researchers at the Joslin Diabetes Center
have shown for the first time that insulin plays a key role in suppressing levels of
glucagon, a hormone involved in carbohydrate metabolism and regulating blood glucose
levels. The study helps in the understanding of why those with diabetes have high blood
glucose levels and could lead to development of a drug aimed at targeting glucagon levels.
"This is a very important finding because until now scientists have only speculated
that insulin may be involved in keeping glucagon levels in check," said Rohit N.
Kulkarni, M.D., Ph.D., Principal Investigator in the Joslin Section on Cellular and
Molecular Physiology and senior author of the study published today in the April issue of
Cell Metabolism. Produced by the alpha cells in the pancreas, glucagon acts on the liver
to help raise blood glucose when it becomes low. It has the opposite effect on the liver
as insulin, which is released from pancreatic beta cells to lower blood glucose when it is
high. In a healthy individual, the two counter each other to keep blood glucose levels
balanced. In individuals with long-standing type 1 or type 2 diabetes, inappropriate
glucagon secretion can increase the chances of hypoglycemia (low blood glucose levels) and
can interfere with insulin therapy. The finding suggests that for people with either type
1 or type 2 diabetes, a therapeutic approach could be developed to target insulin
receptors or proteins in alpha cells in order to suppress glucagon secretion. In addition,
the research may also help in the understanding of why patients with type 1 diabetes in
particular, who are required to inject insulin on a regular basis, are at risk for
hypoglycemia. It was thought that this increased risk was linked in some way to insulin
receptors in the alpha cells, an idea that today's study suggests is in fact the case, Dr.
Kulkarni explained. "This gives us some insight into the cause of hypoglycemia, the
most common complication in patients with type 1 diabetes," he said. "Injecting
insulin leads to a decrease in blood glucose. If it starts to go too low, glucagon
normally kicks in to prevent hypoglycemia. But, what happens in diabetes is the alpha
cells become desensitized by repeated insulin injections over many years and they start to
behave abnormally. We believe this is linked to insulin receptor function."
Joslin Study Identifies
Good Energy Burning Fat in Lean Adults
Researchers at the Joslin Diabetes Center
have demonstrated that adult humans still have a type of good fat previously
believed to be present only in babies and children. Unlike white fat, which stores energy
and comprises most body fat, this good fat, called brown fat, is active in burning
calories and using energy. The finding, reported in the April 9th issue of The New England
Journal of Medicine, could pave the way for new treatments both for obesity and type 2
diabetes.Scientists had thought that brown fat only existed in humans during childhood and
was mostly gone by adulthood. The paper shows that brown fat not only exists in adult
humans, but also for the first time, that the fat is metabolically active. The fact
that there is active brown fat in adult humans means this is now a new and important
target for the treatment of obesity and type 2 diabetes, said C. Ronald Kahn, M.D.,
senior author and Head of the Joslin Section on Obesity and Hormone Action and the Mary K.
Iacocca Professor of Medicine at Harvard Medical School. Obesity is a major risk factor
for type 2 diabetes. According to the researchers, the idea behind a new therapy would be
to find a way to stimulate brown fat growth to both control weight and improve glucose
metabolism. Not only did we find active brown fat in adult humans, we found
important differences in the amount of brown fat based on a variety of factors such as
age, glucose levels and, most importantly, level of obesity, said lead author Aaron
Cypess, M.D., Ph.D., a Research Associate and Staff Physician at Joslin. Not surprisingly,
the study found that younger patients were more likely to have larger amounts of brown
fat, and the brown fat was more active during colder weather, keeping with its role of
burning energy to generate heat. Brown fat was also more common in adults who were thin
and had normal blood glucose levels.
Cigarette smoke may alter immune
response in COPD exacerbations
Smoking cigarettes is not only the
principle cause of chronic obstructive pulmonary disease (COPD), but it may change the
body's immune responses to bacteria that commonly cause exacerbations of the disease,
according to new research in a mouse model. "It is well established that smoking is
the main risk factor for COPD. But our research also suggests that cigarette smoke
substantially changes the immune response to bacteria, which means that patients with COPD
who smoke are weakening their body's ability to deal effectively with bacterial invaders.
This may cause even further progression of the disease," said Martin Stämpfli,
Ph.D., an associate professor at McMaster University, the principle investigator of the
study. "We wanted to see whether and how cigarette smoke would change the
inflammatory response to the bacteria that is the culprit behind many COPD exacerbations,
nontypeable Haemophilus influenzae or NTHI." Their results were published in the
second issue of April of the American Journal of Respiratory and Critical Care Medicine.
Dr. Stämpfli and colleagues tested the effects of cigarette smoke exposure on
inflammation and immune response in mice that were exposed to cigarette smoke twice daily
five days a week for either eight weeks or four days then challenged with an intranasal
inoculation of NTHI. The cigarette smoke exposure roughly approximated that of an
"average" human smoker (within the limitations of a model with differing
metabolic processes.) Control mice were not exposed to cigarette smoke, but were
inoculated with NTHI as were the cigarette smoke-exposed mice. The researchers found that
mice that were exposed to cigarette smoke, whether for four days or for eight weeks,
showed distinct shifts in their immune-response profile, namely an increase in
inflammation of the lungs after the NTHI challenge, increased weight-loss in response to
the bacterial infection and, notably, a shift in the expression of inflammatory markers.
New, simple method identifies
preterm infants at risk of eye disease
A simple way of establishing which preterm
infants are at risk of developing the eye disease ROP is to follow their weight gain. A
new study from the Sahlgrenska Academy, University of Gothenburg, Sweden, suggests that
following weekly weight development might replace the need for considerably more expensive
ophthalmological examinations. Every year around 1000 Swedish infants are born more than
two months prematurely. Preterm infants are at increased risk of damage to several
important organs, including the brain, lungs, guts and eyes. Around 350 of these infants
develop the eye disease retinopathy of prematurity (ROP) which, if left untreated, can
threaten their sight. Ten per cent, or around one hundred, of the preterm infants need the
same treatment to prevent blindness. "In the past 50 years it has been routine for
all infants born very prematurely to be examined several times by ophthalmologists to
identify children who need treatment for ROP, but this expensive method of screening can
now perhaps be replaced by a considerably simpler and cheaper method, so that
ophthalmological examination can be avoided in most cases," says Professor Ann
Hellström of Sahlgrenska Academy. The research team has previously identified another
important link between preterm birth and vascular disease in the eye, the protein IGF-1,
which is strongly linked to the infant's weight gain. Assisted by statisticians at the
University of Gothenburg, the researchers have developed an assessment model known as
WINROP (Weight IGF-1 Neonatal ROP), which is based on weekly measurements of the infant's
weight and analyses of the serum levels of IGF-1. "However, one would prefer not to
take any blood samples from the preterm infants, and therefore we wanted to investigate
whether our surveillance model worked if we only used the infant's weight. We found that
it works extremely well," says Professor Hellström. In a review of medical records,
information on the weekly weights of 350 infants was entered into the model, and the
outcome was compared with the ophthalmological examinations performed on them. "All
infants at risk were on average identified a few months before the ophthalmologist had
seen signs of ROP requiring treatment. The method could therefore not just save money but
also make it possible for infants with eye problems to be identified earlier," says
Professor Hellström.
Altered gene can increase risk of
schizophrenia
Rutgers geneticist Linda Brzustowicz and
her colleagues have identified a specific DNA change that is likely to increase risk for
developing schizophrenia in some people. It provides a potential mechanism that may be a
point of entry for drug therapy, consistent with the growing trend of personalized
medicine. The research findings are reported in the April issue of the American Journal of
Psychiatry (AJP). An accompanying editorial highlights the significance of this work.
Brzustowicz, a professor of genetics at Rutgers, The State University of New Jersey, and
board-certified psychiatrist, said that the research has demonstrated a functional DNA
change that increases gene expression. This conclusion is based on its presence in the
genes of a Canadian study population of 24 families where multiple individuals had been
diagnosed with schizophrenia. The gene in question, NOS1AP, previously known as CAPON, is
one which Brzustowicz has been studying for six years. The paper also presents an
innovative statistical method, Posterior Probability of Linkage Disequilibrium (PPLD).
This is the work of co-author Veronica Vieland of The Research Institute at Nationwide
Children's Hospital, Columbus, Ohio. The new analytical technique quantifies the
statistical evidence for association, in this case between the altered gene and
schizophrenia. The researchers evaluated 60 variants of the gene or single nucleotide
polymorphisms (SNPs). "Our use of the PPLD was really helpful in sorting the
evidence. It showed that of the 60 SNPs we were evaluating, three had a much higher
probability of association with the illness," Brzustowicz said. "This paved the
way for our next step doing a functional analysis using cells grown in culture
which is much more labor intensive. We had reduced our 60 candidates down to a
short list of three, which greatly simplified this next step." Each of the three
candidate SNPs was introduced into separate cultures of identical cloned cells derived
from human brain tissue. The cultures differed only in which of the SNP variants was
introduced. The challenge was to measure the quantity of overexpression, that is, how much
excess protein was being produced by each of the three variants.
Oral contraceptives associated with
increased risk of lupus
The ratio of women to men with the
autoimmune disease systemic lupus erythematosus (SLE) is nine to one and the incidence
increases after puberty. Hormones secreted by the body are therefore believed to play an
important role in the origins of the disease. A new large, population-based observational
study found that the use of oral contraceptives was associated with an increased risk of
SLE, particularly among women who had recently started taking them. The study was
published in the April issue of Arthritis Care & Research
(http://www3.interscience.wiley.com/journal/77005015/home). Led by Dr. Samy Suissa of the
Centre for Clinical Epidemiology at Jewish General Hospital of McGill University in
Montreal, researchers obtained data on more than 1.7 million women ages 18-45 from the
U.K. General Practice Research Database, which contains more than 6 million people. The
women all had prescriptions for combined oral contraceptives (COCs) containing estrogen
and progestogen. During an average of eight years of follow-up, 786 women had a first-time
diagnosis of SLE. Each case was matched with up to 10 controls among women without SLE at
the time of the case's diagnosis. The results showed that the use of COCs was associated
with a significant increased risk of newly diagnosed SLE. This was mostly limited to the
first three months of use with first- and second-generation contraceptives containing
higher doses of estrogen, suggesting "an acute effect in susceptible women and
possibly a dose-response effect of estrogen on SLE onset," according to the authors.
They note that estrogen can directly modulate the immune response, which could complete
the action of some sex-linked genes and contribute to the genetic predisposition of the
disease, and it has also been shown to have an effect on the breakdown of immune tolerance
seen in SLE. Previous studies on the risk of SLE following use of oral contraceptives have
had conflicting results, but the results of the current study are consistent and
complement those of the NIH-sponsored Nurses' Health Study. "Our findings that
longer-term use of contraceptives is associated with an increased risk of incident SLE
(albeit of lower magnitude) and that current use of contraceptives with higher doses of
ethinyl estradiol is associated with an increased risk of incident SLE, suggest a possible
dose-response effect of estrogen on SLE onset, which could be an alternative or additional
mechanism to favor occurrence of the disease," the authors state. They note that the
absence of significant increased risk in third-generation contraceptives may be related to
the lower doses of estrogen compared to earlier generations.
Growth factor TGF-B helps maintain
health of retinal blood vessels
Scientists at Schepens Eye Research
Institute have found that the growth factor known as TGF-? is essential to the health of
blood vessels in the retina and that blocking it can cause retinal dysfunction. These
findings, published in the April 2 issue of PLoS ONE, may have an important impact on the
prevention and treatment of diseases such as diabetic retinopathy and macular
degeneration. "These results are significant because they add to our understanding of
the molecules that help to maintain blood vessels in a healthy state," says Patricia
D'Amore, PhD, senior scientist at Schepens and principal investigator of the study, who
adds that this information may be useful in understanding the changes that occur in the
retinal microvasculature prior to the development of proliferative diabetic retinopathy.
"Insight into the role of this growth factor may also help clinicians monitor the use
of systemic drugs targeting TGF-?, which is elevated in a number of conditions (such as
cancer and fibrotic diseases) to limit any vision problems that might occur as a side
effects." adds Tony Walshe, PhD, the first author of the study and a Postdoctoral
Fellow in the D'Amore's laboratory team. Capillaries are the smallest blood vessels in the
body and the site at which oxygen and nutrients are transferred from the blood to the
tissues. A capillary is composed of an endothelial cell, which forms the lining of the
small tube, and a pericyte, which wraps around the outside of the tube. Scientists have
long believed that communication between these two cell types is necessary to maintain
blood vessel structure and function. According to Walshe, the goal of the PLoS ONE study
was to determine if TGF-? plays a role in keeping blood vessels functioning normally. In
previous experiments using tissue cultures, the D'Amore laboratory had identified TGF-? as
a protein that results from the communication between the two cell types and which they
use to maintain the health of the small blood vessels. In the current study, the team
wanted to confirm that finding in animals.
Test predicts who will develop
end-stage renal disease
Measuring kidney function by assessing two
different factorsglomerular filtration rate (GFR) and urinary albumin
levelshelps determine which patients with chronic kidney disease (CKD) will develop
end-stage renal disease (ESRD), according to a study appearing in the May 2009 issue of
the Journal of the American Society Nephrology (JASN). This combination test could help
physicians identify patients at high risk of serious kidney trouble and allow them to
intervene at an early stage. While there is a high prevalence of CKD worldwide, relatively
few individuals with the disease develop ESRD, expected to affect 785,000 people in the
U.S. by 2020 (current annual cost: $32 billion). Physicians and researchers have looked
for ways to identify which patients will progress to ESRD in order to target patients most
in need of extensive treatment, and help establish clinical guidelines and public health
plans for treating patients with CKD. Stein Hallan, MD, PhD (St. Olav University Hospital,
Norway), and his colleagues recently conducted a study to see if combining two tests
commonly used to measure kidney function might help predict ESRD. One test measures an
individual's estimated glomerular filtration rate (eGFRa measure of the volume of
fluid filtered by the kidneys), while the other measures the amount of albumin (the
predominant protein in the blood) that is excreted in urine. A high urinary albumin level
indicates a rapid rate of kidney disease progression, and a low eGFR indicates an advanced
stage of disease. The researchers analyzed data from 65,589 adults who participated in the
population-based Nord-Trøndelag Health (HUNT 2) Study and found 124 individuals who
developed ESRD after more than 10 years of follow-up. Combining urinary albumin and eGFRs
results identified more than 65% of patients who would develop this condition. Other
factors such as hypertension, diabetes, smoking, obesity, and cardiovascular disease did
not provide any additional information that could be used to predict who would develop
ESRD. "We provide clear evidence
that reduced eGFR should always be
complemented by information on urine-albumin to yield optimal prediction of the risk of
progression to ESRD," said Dr. Hallan. He added that combining these measurements
might also help reduce the number of patients referred to specialists without losing the
ability to detect future ESRD cases.
Enzyme therapy slows kidney
function decline
For men with Fabry disease, enzyme
replacement therapy (ERT) with agalsidase alfa slows deterioration of kidney function,
reports a study in the online edition of the Journal of the American Society of Nephrology
(JASN). "The results provide further evidence that ERT with agalsidase alfa may slow
the progression of kidney disease, provided that ERT is initiated early in the disease
process," comments Michael L. West, MD (Dalhousie University, Canada). The
researchers pooled the results of three previous clinical trials of ERT with agalsidase
alfa in 108 men with Fabry diseasea rare genetic disorder. Without treatment, Fabry
disease causes progressive loss of kidney function, eventually leading to end-stage renal
disease. During treatment with an inactive placebo, kidney function declined rapidly. By
comparison, during treatment with agalsidase alfa (1 to 4.5 years), the rate of decline
slowed considerably. The response to treatment was not as good for patients with lower
initial kidney function. "This underlines the importance of prompt diagnosis and
intervention in patients with Fabry disease," adds Dr. West. The study was one of the
largest ever of men with Fabry disease and included the most accurate techniques of
measuring kidney function. The study also had important limitations: it used data from
different studies performed at different times; it represented a relatively narrow range
of patient characteristics, specifically excluding children and women; and it lacked
adequate data for full statistical analysis. While not approved for use in the US,
Agalsidase alfa is approved for use in over 40 countries including Canada, European
countries, Argentina, Australia, and Japan. A related drug called agalsidase beta is
approved in the US.
Prune juice not necessary - New
research should make bowel movements easier
If you hate prune juice and chalky fiber
supplements, just sit down and relax. Help is on the way. In a research report published
online in The FASEB Journal (http://www.fasebj.org), a team of researchers has discovered
a new way to make it a lot easier to go to the bathroom, especially when all other methods
fail. Specifically, they have found a group of nerve ending receptors which, when
stimulated, causes the bowels to pass waste, and the specific receptor needed to activate
bowel clearance. Furthermore, they tested chemicals that work with those receptors,
providing a blueprint for the development of new laxatives. "We hope that the
receptor identified by our study would be exploited more in the design of drugs to treat
constipation," said Bindu Chandrasekharan, a researcher from Emory University who was
involved in the study.
The research involved two groups of mice, focusing on a type of receptor also present on
human nerves in the gut (a type of adenosine receptor). The first group of mice had normal
adenosine receptors on these nerves and normal bowel movements. The second group of mice
completely lacked these adenosine receptors and showed familiar signs of constipation. The
researchers started with simple experiments such as comparing the wet weight, dry weight,
and water content in the stools of both groups. The mice were also made to drink a dye not
absorbed by the body to see how it passed or did not pass. In addition, the researchers
used microscopic lasers to separate the nerve cells from the bowel to determine exactly
where the receptors are located. Then they tested various chemicals that can activate or
inhibit the nerve receptors.
Blood tests reveal tobacco smoke
residues in non-smoking New Yorkers
More than half of non-smoking New Yorkers
have elevated levels of cotinine in their blood meaning that they were recently
exposed to toxic second-hand smoke in concentrations high enough to leave residues in the
body. Cotinine, a by-product of nicotine breakdown, is not harmful itself but signals
exposure to environmental tobacco smoke. A Health Department study, published online this
week in the journal Nicotine and Tobacco Research, shows that 57% of adult New Yorkers
(2.5 million) have elevated cotinine levels, compared to 45% of adults nationwide a
finding that may reflect the city's dense, urban character. Second-hand smoke contains
many harmful chemicals. It is known to cause cancer and heart disease in adults, as well
as serious health problems for children. The data come from the New York City Health and
Nutrition Examination Survey, which was conducted in 2004, one year after New York City's
smoke-free air law took effect. Although the law protects non-smokers from the dangers of
second-hand smoke at work and in some public places, this study shows that many
non-smokers are not fully protected. Creating a smoke-free home is the most important step
that New Yorkers can take to protect their families. "Tobacco smoke is a toxic
pollutant," said Dr. Thomas R. Frieden, New York City Health Commissioner. "Most
New York City non-smokers are breathing in dangerous chemicals in second-hand smoke,
potentially increasing the risk of cancer and heart disease. Households with a smoker
should set a 'no smoking' policy at home to protect the family. We encourage all New
Yorkers who smoke to quit this is the best way to protect yourself and
others."
"The study provides more evidence of the pervasiveness of second-hand smoke,"
said Jennifer Ellis, PhD, a former Health Department epidemiologist and the study's lead
author. "It's not clear why New Yorkers experience more exposure, despite the city's
relatively low smoking rate. It may be that living and working in close quarters with one
another puts us at higher risk."
Parkinson's disease medication
triggers destructive behaviors
A new study conducted at Mayo Clinic
reports that one in six patients receiving therapeutic doses of certain drugs for
Parkinson's disease develops new-onset, potentially destructive behaviors, notably
compulsive gambling or hypersexuality. The study extends findings from two Mayo case
series published in 2005 that reported a connection between dopamine agonist medications
and compulsive gambling or hypersexuality. Dopamine agonists are a class of drugs that
include pramipexole and ropinirole. They are commonly used to treat Parkinson's disease,
but low doses also are used for restless legs syndrome. They uniquely stimulate brain
limbic circuits, which are thought to be fundamental substrates for emotional, reward and
hedonistic behaviors. "The 2005 case series alerted us that something bad was
happening to some unfortunate people. This study was done to assess the likelihood that
this effect would happen to the average Parkinson's patient treated with these
agents," says J. Michael Bostwick, M.D., Mayo Clinic psychiatrist who spearheaded the
new study. It is published in the April issue of Mayo Clinic Proceedings. The researchers
analyzed the medical records of patients with Parkinson's disease residing in counties
surrounding Rochester, Minn., who received their primary neurological care at Mayo Clinic
in Rochester between 2004 and 2006. This group included 267 patients. Of those, 66 were
taking dopamine agonists for their Parkinson's disease. Of those 66, 38 were taking the
drugs in therapeutic doses (doses expected to be at least minimally beneficial). The
findings were definitive. Seven patients experiencing new-onset compulsive gambling or
hypersexuality were taking dopamine agonists in therapeutic doses. None of the other
Parkinson's disease patients developed compulsive gambling habits or hypersexuality,
including the 28 patients on subtherapeutic dopamine agonist doses or the other 201
patients not taking dopamine agonists. None of the 178 patients treated only with the
standard drug for Parkinson's disease, carbidopa/levodopa, developed these behaviors.
Music Reduces Stress in Heart
Disease Patients
Listening to music may benefit patients who
suffer severe stress and anxiety associated with having and undergoing treatment for
coronary heart disease. A Cochrane Systematic Review found that listening to music could
decrease blood pressure, heart rate, and levels of anxiety in heart patients. Living with
heart disease is extremely stressful. The uncertainties and anxieties surrounding
diagnosis and the various medical procedures involved in treatment can significantly
worsen the condition. For example, stress can increase blood pressure, leading to
increased risk of complications. Music listening may help to alleviate stress and
therefore reduce this risk. "Our findings suggest music listening may be beneficial
for heart disease patients," says Joke Bradt, who works at the Arts and Quality of
Life Research Center at Temple University in Philadelphia. "But the trials we looked
at were generally small and varied in terms of styles of music used and length of music
sessions. More research on the specifics of music listening is certainly warranted."
The researchers reviewed data from 23 studies, which together included 1,461 patients. Two
studies focused on patients treated by trained music therapists, but most did not, using
instead interventions where patients listened to pre-recorded music on CDs offered by
healthcare professionals.
Weak social ties at workplace
increase risk of burn-out
Long-term leaves of absence tied to
stress-related diagnoses are often preceded by a long period without any secure and
comforting social relations. This is shown in a recently published study in public health
science at Karlstad University in Sweden. Sickness leaves are a multifaceted problem
with consequences for the individual, the persons closest friends and relations, the
employer, and society, says Ulla-Britt Eriksson, who authored the doctoral
dissertation in public health science. Enhanced knowledge of what conditions affect
the process leading to long-term sickness leave provides a valuable platform for both
preventive and rehabilitative measures. The dissertation described how long-term
sickness leave due to burn-out and other mental diagnoses can be understood. What preceded
the sickness leave is depicted as a process in which the individual is gradually emptied
of feelings that sustain the life-giving force that provides joy and involvement and
serves as a basis for mental well-being. This force is nourished by secure and comforting
social relations with other people. Individuals on long-term sickness leave made it clear
that these preconditions were lacking in their surroundings. The overall aim of the
dissertation has been to describe and understand the processes that lead to long-term
sickness leave from the point of view of the individual taking the leave, says
Ulla-Britt Eriksson. The focus has been on sickness leaves tied to mental,
stress-related diagnoses, with a special emphasis on so-called burn-out diagnoses.
CSHL researchers explain process by
which cells 'hide' potentially dangerous DNA segments
The DNA in the 23 pairs of chromosomes in
each of the billions of cells of the human body is so tightly packed that it would measure
six feet in length if stretched end to end. A genome of this size can squeeze into a
cell's tiny nucleus because it is compressed into highly condensed chromatin fibers by
proteins called histones.All chromatin in the cell nucleus represents a massive
condensation of the genetic material. But a portion of it might well be called
super-condensed; it forms a kind of chromatin called heterochromatin. The genes contained
within these portions of the genome are effectively "silenced" because they
cannot be accessed by the cell's DNA-activating machinery. These "hidden" parts
of the genome also include highly repetitive, gene-poor, regions. Some of these, if
unpacked, would set loose DNA sequences that act like parasites able to jump around
to other areas, sometimes randomly, unleashing genetic chaos.To assemble heterochromatin,
numerous molecules participate in an elaborate series of maneuvers that have gradually
come to light. "But scientists have been a little hazy on the initial steps and
requirements that get this process going," says Professor Leemor Joshua-Tor, Ph.D.,
of Cold Spring Harbor Laboratory (CSHL). She and her research team have now brought this
process into sharper focus by identifying a critical requirement for heterochromatin to be
established in the nucleus.In a report that appears online on April 9th in the journal
Molecular Cell, they show that the assembly of heterochromatin depends on the strength
with which a protein called Chp1 binds to a specific target site located on a histone
protein that has attached to the double helix.
Small RNAs can play critical roles
in male infertility/contraception
University of Nevada School of Medicine
scientists in the Department of Physiology and Cell Biology have discovered insight into
the reproductive workings of the male sex chromosome that may have significant
implications for male infertility and contraception. This important discovery has been
published in Nature Genetics, one of the highest-ranking journals in the field of
biomedical research based upon the impact factor.
The study findings indicate that the X chromosome in developing sperm cells encodes
numerous tiny ribonucleic acids called microRNAs despite the fact that that most of genes
on the X chromosomes are suppressed. This unprecedented observation implies that these
small RNAs have critical roles in chromosome inactivation and also in sperm formation.
"The sex chromosome silencing in meiotic male germ cells is a well-known phenomenon,
which has been termed meiotic sex chromosome inactivation. I was surprised when we first
observed that numerous microRNAs were highly expressed in these cells," said Wei Yan,
M.D., Ph.D., principal investigator for the study and associate professor of physiology
and cell biology at the School of Medicine. Working in collaboration with Dr. John
McCarrey, professor of molecular biology and reproductive biology at the University of
Texas, San Antonio, Yan's research group further investigated all the known X-linked
microRNAs. Their data confirm that these X chromosome-derived microRNAs indeed escape the
silencing effects and mange to be expressed. "This finding opens a new avenue towards
understanding the role of these small RNA species in the control of sperm production.
Worldwide, one in nine couples in their reproductive age experience infertility. On the
other hand, the number of unintended pregnancy is increasing yearly. Since these small
RNAs are involved in the control of sperm formation, they can be causative factors in male
infertility and also can be used as non-hormonal male contraceptive targets," added
Yan.
Scientists identify chemical
compound that may stop deadly brain tumors
Researchers at the University of North
Carolina at Chapel Hill School of Medicine have identified a compound that could be
modified to treat one of the most deadly types of cancer, and discovered how a particular
gene mutation contributes to tumor growth. The findings and potential treatment apply to a
type of brain tumor called secondary glioblastoma multiforme (GBM). GBMs are part of a
larger group of brain tumors called malignant gliomas, which is the type of cancer Senator
Edward Kennedy suffers from. A report of the research will appear in the April 10, 2009
issue of the journal Science. In experiments with tumor cells, the researchers reversed
the effects of a mutation in a gene called isocitrate dehydrogenase-1 (IDH1) by
replenishing a compound called ?-ketoglutarate (?-KG). "When the IDH1 gene is
mutated, the level of ?-KG is reduced, which in turn contributes to tumor growth by
helping to increase the supply of nutrients and oxygen to tumor cells. When we added the
?-KG to tumor cells, the effects caused by the IDH1 mutation were reversed," said Yue
Xiong, Ph.D., William R. Kenan Jr., Distinguished Professor of Biochemistry and Biophysics
and a member of the UNC Lineberger Comprehensive Cancer Center. "If scientists can
develop ?-KG into a clinical drug, it could potentially be used for treating brain tumor
patients who have this specific gene mutation. The ?-KG compound is already there; it only
needs to be modified to be used clinically, so that may save a lot of time," Xiong
said.
New therapeutic strategy could
target toxic protein in most patients with Huntington's disease
Howard Hughes Medical Institute researchers
have designed tiny RNA molecules that shut off the gene that causes Huntington's disease
without damaging that gene's healthy counterpart, which maintains the health and vitality
of neurons. Laboratory studies suggest that a single small interfering RNA could reduce
production of the damaging Huntingtin protein in nearly half of people with the disease.
Another 25 percent of patients might benefit from one of a set of four additional small
interfering RNAs. Phillip D. Zamore, an HHMI investigator at the University of
Massachusetts Medical School in Worcester, and his colleagues reported their findings in
an article published April 9, 2009, in the journal Current Biology. There is no treatment
for Huntington's disease, which is caused by a mutant form of the Huntingtin gene.
Huntingtin is required for healthy nerve cells, but the mutant gene makes a toxic protein
that contains excess amounts of the amino acid glutamine. The key to whether the
Huntingtin gene is normal or defective lies in a kind of genetic stutter: a repetitive
sequence of the DNA triplet CAG, which codes for the amino acid glutamine. Stretches of
CAG "repeats" appear in every human being's Huntingtin gene, but the length
varies. Whereas the normal gene has a sequence of between six and 34 CAG repeats, the
abnormal gene contains many more. In fact, any stretch of DNA containing more than 40 of
these repeats ensures that its bearer will develop Huntington'sthe greater the
number of repeats, the earlier the disease strikes and the greater its ferocity. The
abnormal Huntingtin protein causes movement disorders, cognitive failure, and ultimately,
death. Children who have a parent with Huntington's disease have a 50 percent chance of
inheriting the disease themselves. Zamore studies how RNA interference can be used to
silence genes selectively. In the 1990s, he and other scientists learned they could shut
down the production of specific proteins by introducing double-stranded RNA into the cell
that is identical to the RNA they wanted to turn off. These strands of RNA, known as short
interfering RNA (siRNA), slice apart the original RNA, which the cell then destroys. But
nine years ago, when researcher Neil Aronin, who is also at UMass Medical School, proposed
using the technique to attack Huntington's, Zamore couldn't see a way. "I explained
to him that you can't," Zamore said. The problem was that the disease gene and its
healthy allele are almost identical, and Zamore told Aronin that he wouldn't be able to
distinguish between the two forms of Huntingtin. "Then, as he was leaving my office,
it occurred to me that you could," he recalled. The key was something called a single
nucleotide polymorphism or SNP.
Biological FM signal maintains
inflammation in cancer, asthma and other diseases
A study published tomorrow (10 April) in
Science examines a key player in conditions such as cancer, inflammatory bowel disease,
rheumatoid arthritis and asthma and has shown that cells use a sophisticated communication
system to coordinate responses to infection and maintain inflammation in the body. This
system is now a target for designing drugs to treat these conditions. Scientists funded by
the Biotechnology and Biological Sciences Research Council (BBSRC), the Medical Research
Council (MRC) and the Engineering and Physical Sciences Research Council (EPSRC) have
combined biological experiments and mathematics to discover the secrets of NF-kappaB
a biological machine that coordinates the setting up and maintenance of
inflammation in the body by broadcasting a signal to surrounding cells. The team from the
Universities of Liverpool, Manchester and Warwick, along with scientists from
pharmaceutical company AstraZeneca (AstraZeneca R & D, Charnwood) have used Systems
biology a multidisciplinary approach that uses a combination of experimental and
theoretical techniques to tackle biological problems to investigate the role of
NF-kappaB. Professor Michael White of the University of Liverpool, who led the research
said: "We know that successive peaks and troughs in the amount of NF-kappaB
forming a wave-like pattern over time can exert exquisite control over many
biological processes that underlie the symptoms of inflammation. Furthermore, what we now
see is that different cell processes are determined once they pick up the frequency of
peaks and troughs in the NF-kappaB signal, just like tuning in to an FM radio
signal."
ISU researcher identifies protein
that concentrates carbon dioxide in algae
Increasing levels of carbon dioxide in the
atmosphere are a concern to many environmentalists who research global warming. The lack
of atmospheric carbon dioxide (CO2) concentration, however, actually limits the growth of
plants and their aquatic relatives, microalgae. For plants and microalgae, CO2 is vital to
growth. It fuels their photosynthesis process that, along with sunlight, manufactures
sugars required for growth.
CO2 is present in such a limiting concentration that microalgae and some plants have
evolved mechanisms to capture and concentrate CO2 in their cells to improve photosynthetic
efficiency and increase growth.
An Iowa State University researcher has now identified one of the key proteins in the
microalgae responsible for concentrating and moving that CO2 into cells.
Aerosols may drive a significant
portion of arctic warming
Though greenhouse gases are invariably at
the center of discussions about global climate change, new NASA research suggests that
much of the atmospheric warming observed in the Arctic since 1976 may be due to changes in
tiny airborne particles called aerosols. Emitted by natural and human sources, aerosols
can directly influence climate by reflecting or absorbing the sun's radiation. The small
particles also affect climate indirectly by seeding clouds and changing cloud properties,
such as reflectivity. A new study, led by climate scientist Drew Shindell of the NASA
Goddard Institute for Space Studies, New York, used a coupled ocean-atmosphere model to
investigate how sensitive different regional climates are to changes in levels of carbon
dioxide, ozone, and aerosols. The researchers found that the mid and high latitudes are
especially responsive to changes in the level of aerosols. Indeed, the model suggests
aerosols likely account for 45 percent or more of the warming that has occurred in the
Arctic during the last three decades. The results were published in the April issue of
Nature Geoscience. Though there are several varieties of aerosols, previous research has
shown that two types -- sulfates and black carbon -- play an especially critical role in
regulating climate change. Both are products of human activity. Sulfates, which come
primarily from the burning of coal and oil, scatter incoming solar radiation and have a
net cooling effect on climate. Over the past three decades, the United States and European
countries have passed a series of laws that have reduced sulfate emissions by 50 percent.
While improving air quality and aiding public health, the result has been less atmospheric
cooling from sulfates. At the same time, black carbon emissions have steadily risen,
largely because of increasing emissions from Asia. Black carbon -- small, soot-like
particles produced by industrial processes and the combustion of diesel and biofuels --
absorb incoming solar radiation and have a strong warming influence on the atmosphere.
Ancient diatoms lead to new
technology for solar energy
Engineers at Oregon State University have
discovered a way to use an ancient life form to create one of the newest technologies for
solar energy, in systems that may be surprisingly simple to build compared to existing
silicon-based solar cells.The secret; diatoms. These tiny, single-celled marine life forms
have existed for at least 100 million years and are the basis for much of the life in the
oceans, but they also have rigid shells that can be used to create order in a natural way
at the extraordinarily small level of nanotechnology. By using biology instead of
conventional semiconductor manufacturing approaches, researchers at OSU and Portland State
University have created a new way to make "dye-sensitized" solar cells, in which
photons bounce around like they were in a pinball machine, striking these dyes and
producing electricity. This technology may be slightly more expensive than some existing
approaches to make dye-sensitized solar cells, but can potentially triple the electrical
output. "Most existing solar cell technology is based on silicon and is nearing the
limits of what we may be able to accomplish with that," said Greg Rorrer, an OSU
professor of chemical engineering. "There's an enormous opportunity to develop
different types of solar energy technology, and it's likely that several forms will
ultimately all find uses, depending on the situation." Dye-sensitized technology, for
instance, uses environmentally benign materials and works well in lower light conditions.
And the new findings offer advances in manufacturing simplicity and efficiency.
"Dye-sensitized solar cells already exist," Rorrer said. "What's different
in our approach are the steps we take to make these devices, and the potential
improvements they offer." The new system is based on living diatoms, which are
extremely small, single-celled algae, which already have shells with the nanostructure
that is needed. They are allowed to settle on a transparent conductive glass surface, and
then the living organic material is removed, leaving behind the tiny skeletons of the
diatoms to form a template.
Babraham researchers reveal how
immune cells can be harnessed to target melanoma
Researchers at the Babraham Institute and
the University of Catanzaro "Magna Graecia", Italy, co-ordinating an
international network of scientists and clinicians from Europe, the USA and Japan, have
identified new mechanisms through which the immune system recognises and responds to
tumours like melanomas. This discovery may offer therapeutic approaches for tackling
metastatic melanoma, an aggressive form of skin cancer responsible for around 2,000 deaths
in the UK each year. These exciting new findings, published in the online edition of the
Journal of Clinical Investigation, reveal how a type of white blood cell - Natural Killer
(NK) cells - tackles tumours, characterising for the first time the molecular interactions
that lead to melanoma destruction. This has advanced understanding of melanoma recognition
by the immune system and has the potential to open up new avenues of research into the
prevention of metastasis by harnessing NK cells natural immunity. Natural Killer
cells are found in the blood, the lymph glands and in tissues such as the liver, the lungs
and the uterus, where they participate in immune defences against infection, cancer, in
reproductive success and in transplantation. They play a key role in the immune response
that targets tumour cells, while sparing healthy cells; mouse models revealed that NK
cells prevent and control tumour growth although, in the case of melanomas, the molecular
interactions behind this and how NK cells control metastatic progression had until now
remained elusive. The team of researchers, led by Francesco Colucci, Group Leader at the
Babraham Institute and Ennio Carbone, of the University of Catanzaro "Magna
Graecia", Italy, studied both human metastatic melanomas - aggressive forms of skin
cancer that have spread to other sites - and spontaneous mouse melanomas.