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News - Week 20 - 2009
Sleep Apnea Increases Heart Disease
Risk
Obstructive sleep apnea, or periodic interruptions in breathing throughout the night,
thickens sufferers' blood vessels. Moreover, it increases the risk of several forms of
heart and vascular disease.Emory researchers have identified the enzyme NADPH oxidase as
important for the effects obstructive sleep apnea has on blood vessels in the lung. The
results are published in the May 1 issue of the American Journal of Respiratory Cell and
Molecular Biology. C. Michael Hart, professor of medicine at Emory University School of
Medicine and Atlanta Veterans Affairs Medical Center, is senior author. Obstructive sleep
apnea is thought to affect one in every 50 women and one in every 25 men in the United
States. Standard treatment involves a mechanical application of air pressure. Anything
that blunts sleep apnea’s effects on blood vessel physiology could reduce its impact
on disease risk, Hart says. Cyclically depriving mice of oxygen – researchers call
this “chronic intermittent hypoxia” -- in a way that simulates obstructive sleep
apnea gives them pulmonary hypertension. Pulmonary hypertension, which can be life
threatening, is a condition in which the right side of the heart has trouble pumping blood
because of resistance in the lung’s blood vessels. Chronic intermittent hypoxia
forces the blood vessels in the lung to make more NADPH oxidase, Hart and his colleagues
found. Mice that lack NADPH oxidase are immune to hypoxia’s effects.
Research shows wide age gap between
possible and actual autism diagnosis
Timely identification and diagnosis of an autism spectrum disorder (ASD) can impact a
child's development and is the key to opening the door to the services and therapies
available to children with autism," says Paul Shattuck, Ph.D., assistant professor at
the George Warren Brown School of Social Work at Washington University in St. Louis.
"Unfortunately, our research shows that the average age of autism diagnosis is nearly
six years old, which is three to four years after diagnosis is possible.
Targeting tumors using tiny gold
particles
It has long been known that heat is an effective weapon against tumor cells. However, it's
difficult to heat patients' tumors without damaging nearby tissues. Now, MIT researchers
have developed tiny gold particles that can home in on tumors, and then, by absorbing
energy from near-infrared light and emitting it as heat, destroy tumors with minimal side
effects. Such particles, known as gold nanorods, could diagnose as well as treat tumors,
says MIT graduate student Geoffrey von Maltzahn, who developed the tumor-homing particles
with Sangeeta Bhatia, professor in the Harvard-MIT Division of Health Sciences and
Technology (HST) and in the Department of Electrical Engineering and Computer Science, a
member of the David H. Koch Institute for Integrative Cancer Research at MIT and a Howard
Hughes Medical Institute Investigator. Von Maltzahn and Bhatia describe their gold
nanorods in two papers recently published in Cancer Research and Advanced Materials. In
March, von Maltzahn won the Lemelson-MIT Student Prize, in part for his work with the
nanorods. Cancer affects about seven million people worldwide, and that number is
projected to grow to 15 million by 2020. Most of those patients are treated with
chemotherapy and/or radiation, which are often effective but can have debilitating side
effects because it's difficult to target tumor tissue.
Weizmann Institute Scientists Show
White Blood Cells Move like Millipedes
How do white blood cells – immune system ‘soldiers’ – get to the site
of infection or injury? To do so, they must crawl swiftly along the lining of the blood
vessel – gripping it tightly to avoid being swept away in the blood flow – all
the while searching for temporary ‘road signs’ made of special adhesion
molecules that let them know where to cross the blood vessel barrier so they can get to
the damaged tissue. In research recently published in the journal Immunity, Prof. Ronen
Alon and his research student Ziv Shulman of the Weizmann Institute’s Immunology
Department show how white blood cells advance along the length of the endothelial cells
lining the blood vessels. Current opinion maintains that immune cells advance like
inchworms, but Alon’s new findings show that the rapid movement of the white blood
cells is more like that of millipedes. Rather than sticking front and back, folding and
extending to push itself forward, the cell creates numerous tiny ‘legs’ no more
than a micron in length – adhesion points, rich in adhesion molecules (named LFA-1)
that bind to partner adhesion molecules present on the surface of the blood vessels. Tens
of these legs attach and detach in sequence within seconds – allowing them to move
rapidly while keeping a good grip on the vessels’ sides.
Hypothyroidism In Women Associated
With Liver Cancer
Women with a history of hypothyroidism face a significantly higher risk of developing
liver cancer, according to a new study in the May issue of Hepatology, a journal published
by John Wiley & Sons on behalf of the American Association for the Study of Liver
Diseases (AASLD). The article is also available online at Wiley Interscience
(www.interscience.wiley.com). Hypothyroidism is the most common thyroid disorder among
U.S. adults, affecting between 8 and 12 percent of the U.S. population, and more women
than men. The condition can cause hyperlipidemia and weight gain and may play a role in
the development of nonalcoholic steatohepatitis which can progress to more severe liver
disease. Studies have also suggested a clinical association between hypothyroidism and
hepatitis C, which is contributing to the country’s rising rate of liver cancer.
Researchers, led by Manal Hassan of Anderson Cancer Center at the University of Texas,
designed a case-control study to better understand the association between hypothyroidism
and the development of liver cancer, also known as hepatocellular carcinoma (HCC), in the
U.S.
Calorie restriction causes temporal
changes in liver metabolism
Moderate calorie restriction causes temporal changes in the liver and skeletal muscle
metabolism, whereas moderate weight loss affects muscle, according to a new study in
Gastroenterology, the official journal of the American Gastroenterological Association
(AGA) Institute. In addition, researchers found that short-term calorie restriction (CR)
with a low-carbohydrate diet caused a greater change in liver fat content and metabolic
function than short-term CR with a high-carbohydrate diet. Insulin resistance is the most
common metabolic complication associated with obesity and is associated with an increased
risk of developing non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes. Although
an energy-deficit diet is the cornerstone of therapy for obesity, the most appropriate
macronutrient composition of diet therapy needed to improve metabolic health remains
controversial. "Our data underscore the complexity of the metabolic effects of
calorie restricition with diets that differ in macronutrient composition, and demonstrate
differences among organ systems in the response to calorie restriction and subsequent
weight loss," said Samuel Klein, MD, of the Washington University School of Medicine
and lead author of the study. "Our findings help explain the rapid improvement in
glucose levels observed after low-calorie diet therapy and bariatric surgery," he
added. In the present study, 22 obese patients were randomized to a high-carbohydrate or
low-carbohydrate energy-deficit diet. A euglycemic-hyperinsulinemic clamp, muscle biopsies
and magnetic resonance spectroscopy were used to determine insulin action, cellular
insulin signaling and intrahepatic triglyceride (IHTG) content before, after 48 hours and
after ~11 wks (7 percent weight loss) of diet therapy. An euglycemic-hyperinsulinemic
clamp is a widely used experimental procedure for the determination of insulin
sensitivity. Researchers found that short-term CR caused a rapid decrease in IHTG content,
an increase in hepatic insulin sensitivity and a decrease in endogenous glucose production
rate, whereas longer-term CR and a moderate 7 percent weight loss improved skeletal muscle
insulin sensitivity in conjunction with an increase in cellular insulin signaling. The
effect of moderate CR in obese patients with either a low-fat or low-carbohydrate diet on
metabolic function is a continuum, with differential effects on specific organ systems.
Brain protein central to both
Parkinson's, drug addiction identified
Scientists have identified a protein that appears not only to be central to the process
that causes Parkinson's disease but could also play a role in muting the high from
methamphetamine and other addictive drugs. The action of the protein, known as organic
cation transporter 3 or oct3, fills a longstanding gap in scientists' understanding of the
brain damage that causes symptoms like tremor, stiffness, slowness of movement and
postural instability. While these are found mainly in patients with Parkinson's disease,
there are more than three dozen other known causes of this array of symptoms, known as
"parkinsonism."In a paper published online this week in the Proceedings of the
National Academy of Sciences, scientists at Columbia University Medical Center and the
University of Rochester Medical Center have shown that oct3, a protein that shepherds
molecules into and out of cells, plays a critical role, bringing toxic chemicals to the
doorstep of the brain cells that die in patients with Parkinson's disease. The team found
that oct3 is involved in the brain's response to addictive drugs like methamphetamine as
well. Precisely what causes Parkinson's disease remains largely a mystery. Some cases have
a known genetic basis, and most others are attributed to environmental causes or a
combination of gene-environment interactions. Doctors know that symptoms of Parkinson's
stem from the death of a very small, specialized group of brain cells known as dopamine
neurons, which produce a chemical needed by another area of the brain to help us move
freely. It's not until most of those brain cells have already died that patients begin to
show symptoms. For decades, scientists have been trying to understand why those cells die.
The latest paper supports a role for astrocytes, a type of cell that is the most common in
the brain but which has been often overlooked by scientists focused more on cells known as
neurons that send electrical signals. Astrocytes' role in Parkinson's is no surprise to
brain experts who have also identified them as a player in Alzheimer's disease,
amyotrophic lateral sclerosis, epilepsy, and other diseases.
Novel gene predicts local
recurrence in early onset breast cancer
A newly discovered gene known as DEAR1 is mutated in breast cancer and is an independent
predictor of local recurrence-free survival in early-onset breast cancer, a research team
headed by scientists at The University of Texas M. D. Anderson Cancer Center reports in
the journal PLoS Medicine. "The correlation with local recurrence is significant
because so many young women have recurrences in the breast, and cancers that do recur tend
to be more aggressive," said senior author Ann McNeill Killary, Ph.D., professor in
M. D. Anderson's Department of Genetics. "Young age has been considered a risk factor
for local recurrence and metastasis. It is important to understand the genetic mechanisms
operating in early-onset breast cancer and to determine whether there is a way to identify
young women who might be at a higher risk of recurrence." After Killary's laboratory
research discovered DEAR1 (ductal epithelium-associated ring chromosome 1) and implicated
it in breast cancer, the team examined a tumor tissue microarray from 123 women whose
breast cancer began between ages 25 and 49, all of whom advanced to invasive disease. Of
these, 56 percent lacked DEAR1 expression in their tumors, which was associated with 58
percent local recurrence-free survival 15 years after surgery. For those with DEAR1
expression, local recurrence-free survival was 95 percent at 15 years.
"Immunohistochemical staining for DEAR1 could potentially be performed in any
hospital setting, and such an assay might predict which women are at a high risk of
recurrence and potentially help guide treatment decisions" Killary said, noting the
results will need to be validated in a larger cohort of patients. Breast cancer that
develops before age 50 tends to be more aggressive and more likely to recur even in the
absence of invasion of the lymph nodes at diagnosis. "Approximately one-fourth of
women without nodal involvement will experience a recurrence up to 12 years after
surgery," Killary said. Of the 123 early-onset patients, 72 percent had no lymph node
involvement at diagnosis.
Estrogen Controls How the Brain
Processes Sound
Scientists at the University of Rochester have discovered that the hormone estrogen plays
a pivotal role in how the brain processes sounds. The findings, published in today's issue
of The Journal of Neuroscience, show for the first time that a sex hormone can directly
affect auditory function and point toward the possibility that estrogen controls other
types of sensory processing as well. Understanding how estrogen changes the brain's
response to sound, say the authors, might open the door to new ways of treating hearing
deficiencies. "We've discovered estrogen doing something totally unexpected,"
says Raphael Pinaud, assistant professor of brain and cognitive sciences at the University
of Rochester and lead author of the study. "We show that estrogen plays a central
role in how the brain extracts and interprets auditory information. It does this on a
scale of milliseconds in neurons, as opposed to days, months or even years in which
estrogen is more commonly known to affect an organism."
Elevated level of certain protein
in urine linked to increased risk for blood clots
Preliminary research suggests that higher than normal levels of the protein albumin in
urine is associated with an increased risk for blood clots in the deep veins of the legs
or lungs (venous thromboembolism; VTE), according to a study in the May 6 issue of JAMA.
The overall incidence of VTE in developed countries is about 0.15 percent per year,
varying from less than 0.005 percent in individuals younger than 15 years to as high as
0.5 percent at 80 years of age. Known risk factors for VTE include stasis (a slowing of
the normal flow) of the blood and changes in the composition of the blood. However, in as
many as 50 percent of VTE cases, none of the known risk factors are present, according to
background information in the article. Microalbuminuria (albumin in urine; 30-300 mg per
24-hour urine collection) is associated with changes in the levels of several coagulation
proteins. The effect of coagulation disorders is more evident in the development of VTE
than of arterial thromboembolism (formation of a blood clot in the arterial system).
"Hence, in theory, a link between microalbuminuria and VTE is likely; however,
research addressing this issue has yet to be conducted," the authors write. Bakhtawar
K. Mahmoodi, B.Sc., of the University Medical Centre Groningen, the Netherlands, and
colleagues conducted a study to assess whether microalbuminuria is associated with VTE.
The ongoing, community-based study, started in 1997, includes all inhabitants of
Groningen, the Netherlands, (age 28 through 75 years [n = 85,421]) who were sent a postal
questionnaire and a vial to collect a urine sample for measurement of urinary albumin
concentration. Of those who responded (40,856), a group (8,592) including more
participants with higher levels of urinary albumin concentration completed screening at an
outpatient clinic. Screening data were collected on urinary albumin excretion (UAE) and
risk factors for cardiovascular and kidney disease.
What separates dangerous blood
vessel plaques from benign ones
Researchers say they have evidence to explain what separates your average blood vessel
plaque from those that are at high risk for triggering the development of
dangerous—even fatal—blood clots. The findings in the May issue of Cell
Metabolism, a Cell Press publication, suggest that drugs designed to tackle a form of
cellular stress might be useful in treating heart disease, which is the number one killer
and getting worse, according to the researchers. "Just about everybody in our society
has atherosclerosis by the time we reach 20," said Ira Tabas of Columbia University
in New York. In atherosclerosis, lipid, inflammation and white blood cells known as
macrophages build up at various spots along blood vessel walls, he explained. The vast
majority of these lesions will never cause any problem whatsoever, but the rest—some
2 percent of all plaques—will eventually lead to the development of an acute blood
clot and to heart attack, sudden death, or stroke. "The billion dollar question is
why 98 percent cause no problem, and 2 percent do." Their report adds support to the
notion that so-called endoplasmic reticulum (ER) stress together with the body's natural
way of coping with that stress is one answer. The ER is a cellular component that serves
two major functions: it is the site where new proteins are made, folded, and transported,
and it is also the central storage depot for the cell's calcium and controls its release,
Tabas explained. When insults to the cell throw those functions off kilter, cells handle
the imbalance via a pathway known as the unfolded protein response (UPR). If times get
really tough, that pathway simply kills off the cells that are suffering. That decision to
die is commandeered by an ER stress effector known as CHOP. "When cells die, it's OK
as long as it's not en masse," Tabas said, noting that we lose billions of cells
every day. "It's a wonderful path to keep the ER in check, and by killing a cell here
and there because of uncorrectable ER stress, the pathway protects the whole organism. In
pathologies, however, this pathway gets overexuberant." Indeed, scientists are
increasingly coming to the realization that ER stress and the body's
"overexuberant" reaction to it are common features of aging, underlying
neurodegenerative disease, and diabetes, for example. In the case of atherosclerosis, ER
stress within plaques could lead to the massive death of cells—and of macrophages in
particular—leading to the generation of a structure called the "necrotic
core." Those necrotic cores are known to be a defining feature of plaques that are
vulnerable to rupture and blood clot formation. While earlier studies had suggested a
correlation between ER stress and vulnerable plaques, the new study is the first to show a
clear causal connection between the two, Tabas said. His group studied two separate
strains of mice, each carrying a specific genetic alteration that makes them especially
prone to develop atherosclerosis. The mice also lacked CHOP, disabling the prodeath branch
of the ER stress pathway.
Gene may 'bypass' disease-linked
mitochondrial defects, fly study suggests
By lending them a gene normally reserved for other classes of animals, researchers have
shown they can rescue flies from their Parkinson's-like symptoms, including movement
defects and excess free radicals produced in power-generating cellular components called
mitochondria. The gene swap also protects healthy flies' mitochondria, and to a large
extent the flies themselves, from the damaging effects of cyanide and other toxins, the
team reports in the May issue of Cell Metabolism, a Cell Press publication. The key gene
(single-subunit alternative oxidase or AOX) in essence acts as a bypass for blockages in
the so-called oxidative phosphorylation (OXPHOS) cytochrome chain in mitochondria. Howard
Jacobs, who led the study at the University of Tampere in Finland, likens that chain to a
series of waterfalls in a hydroelectric power station. Only, in the case of mitochondria,
it is electrons that flow to release energy that is captured in molecular form. "This
is the first whole organism test for the idea that you can take a gene that encodes a
single polypeptide and bypass OXPHOS where it is blocked," said Jacobs, emphasizing
that OXPHOS includes dozens of components and hundreds of proteins. "You may lose
power from one [molecular] 'turbine,' but power from the others can be restored. With a
single peptide, you can bypass two-thirds of the system. That's the beauty of the
idea." Defects in mitochondrial OXPHOS are associated with diverse and mostly
intractable human disorders, the researchers said. Therefore, there's a chance that the
strategy might also prove beneficial in mammals, including humans, which like arthropods
have also lost the AOX gene over the course of evolution. (Arthropods are represented by
insects, spiders, and crabs.) On the other hand, most plants, animals, and fungi do
possess an alternative mitochondrial respiratory chain, which can bypass the OXPHOS system
under specific physiological conditions. In plants, AOX is thought to be essential for
maintaining energy balance under daylight conditions. In fungi, AOX has been implicated in
the control of longevity and resistance to oxidative stress. In many animals, too,
including annelid worms, mollusks, and urochordates—an underwater filter-feeding
sister group to vertebrates— AOX is present and is believed to provide resistance to
oxidative stress.
Genetically engineered mice don't
get obese, but do develop gallstones
Obesity and gallstones often go hand in hand. But not in mice developed at Washington
University School of Medicine in St. Louis. Even when these mice eat high-fat diets, they
don't get fat, but they do develop gallstones. Researchers say the findings offer clues
about genetic factors related to gallstones, and they believe better understanding of
those factors may one day allow physicians to monitor people at risk and even, perhaps, to
intervene before gallstones become a serious problem. Learning more about susceptibility
to gallstones is an important public health issue, particularly in the United States.
Between 16 million and 22 million Americans have gallstones, which are deposits of
cholesterol or calcium salts that form in the gallbladder or in the bile ducts. In many
cases, people require surgery, and more than half a million undergo operations to treat
gallstones and remove the gallbladder each year.
UCSF study shows attitudes toward
tobacco industry linked to smoking behavior
A new study by UCSF researchers concludes that media campaigns that portray the tobacco
industry in a negative light and that appeal to young adults may be a powerful
intervention to decrease young adult smoking. The study sheds light on the relationship
between attitudes toward the tobacco industry and smoking behaviors of young adults aged
18 to 25 years, the age group with the highest smoking rate among any in the United
States. The study is the first to link attitudes about the tobacco industry to smoking
attitudes and behavior among a national sample of young adults, according to the research
team. To determine attitudes, the researchers asked respondents how strongly they agreed
or disagreed with three statements: Taking a stand against smoking is important to me; I
want to be involved with efforts to get rid of cigarette smoking; and I would like to see
cigarette companies go out of business. The researchers found that those who agreed with
those statements and supported action against the tobacco industry were one-third as
likely to be smokers as those who did not support action against the tobacco industry.
Among current smokers, those who had a negative attitude towards the tobacco industry were
over four times more likely to plan to quit smoking than smokers who did not support
action against the tobacco industry.
Camphor-containing Products May
Cause Seizures in Children
Inappropriate use of camphor-containing products may be a common and underappreciated
cause of seizures in young children, according to a new study by researchers at Albert
Einstein College of Medicine of Yeshiva University. The study, published in this month's
issue of Pediatrics, calls for efforts to educate communities about the hazards of camphor
and to crack down on illegally marketed camphor products. Camphor—a naturally
occurring waxy substance with a strong, aromatic odor—is found in many consumer
products. Scientists have known for some time that camphor can cause serious health
problems, including seizures. Children are particularly vulnerable to the toxic effects of
camphor, which is easily absorbed through the skin and mucous membranes. As a result, the
FDA limits the camphor content of common cold preparations, and federal and New York City
regulations require that camphor-containing products be properly labeled. Nevertheless,
camphor products without proper or complete labeling are widely available and commonly
used for medicinal, spiritual and aromatic purposes and for pest control, especially in
the Hispanic community.The Einstein researchers report on three cases of
camphor-associated seizures in children seen in the emergency department of a single New
York City hospital?Children's Hospital at Montefiore in the Bronx?over a two-week period.
In the first case, a 15-month-old Hispanic boy accidently ingested camphor cubes that his
parents were using to ward off evil spirits. In the second case, a 22-month-old Hispanic
boy ate a camphor-containing product that was placed around his apartment to control
roaches. In the third case, a three-year-old Hispanic girl had been heavily exposed to
numerous camphor-containing products, including crushed tablets spread around the house to
control roaches and an ointment that her mother had rubbed on her skin hourly for 10 hours
before her seizures began. (Interestingly, this girl and two of her siblings had a history
of seizures that may have been due to previous camphor exposure.)
Massage after exercise myth busted
by Queen’s research team
A Queen’s University research team has blown open the myth that massage after
exercise improves circulation to the muscle and assists in the removal of lactic acid and
other waste products. “This dispels a common belief in the general public about the
way in which massage is beneficial,” says Kinesiology and Health Studies professor
Michael Tschakovsky. “It also dispels that belief among people in the physical
therapy profession. All the physical therapy professionals that I have talked to, when
asked what massage does, answer that it improves muscle blood flow and helps get rid of
lactic acid. Ours is the first study to challenge this and rigorously test its
validity.” The belief that massage aids in the removal of lactic acid from muscle
tissue is so pervasive it is even listed on the Canadian Sports Massage Therapists website
as one of the benefits of massage, despite there being absolutely no scientific research
to back this up. Kinesiology MSc candidate Vicky Wiltshire and Dr. Tschakovsky set out to
discover if this untested hypothesis was true, and their results show that massage
actually impairs blood flow to the muscle after exercise, and that it therefore also
impairs the removal of lactic acid from muscle after exercise.
X-rays help predict permanent bone
damage from bisphosphonates
Breast cancer patients, individuals at risk for osteoporosis and those undergoing certain
types of bone cancer therapies often take drugs containing bisphosphonates. These drugs
have been found to place people at risk for developing osteonecrosis of the jaws (a
rotting of the jaw bones). Dentists, as well as oncologists, are now using X-rays to
detect "ghost sockets" in patients that take these drugs and when these sockets
are found, it signals that the jawbone is not healing the right way. Early detection of
these ghost sockets can help the patient avoid permanent damage to their jawbone,
according to an article in the March/April 2009 issue of General Dentistry, the Academy of
General Dentistry's (AGD) clinical, peer-reviewed journal. A ghost socket occurs when the
jawbone is not healing and repairing itself the right way. "The good news is that
even though these ghost sockets may occur, by using radiographic techniques we can see
that the soft tissue above these sockets can still heal," according to Kishore
Shetty, DDS, MS, MRCS, lead author of the report. Dr. Shetty states these findings are
important news to learn about because early prevention and detection can halt permanent
damage from happening to a patient's jawbone. In 2006, about 191 million prescriptions of
oral bisphosphonates worldwide were written. The National Osteoporosis Foundation
estimates that nearly 44 million people in the United States are at risk for developing
osteoporosis. Currently, approximately 10 million Americans suffer from the disease.
Bisphosphonates are a family of drugs used to prevent and treat osteoporosis, multiple
myeloma, Paget's disease (bone cancers), and bone metastasis from other cancers. These
drugs can bond to bone surfaces and prevent osteoclasts (cells that break down bone) from
doing their job. Other cells are still working trying to form bone, but it may turn out to
be less healthy bone leading to the ghost-like appearance on X-rays.
Vibration plate machines may aid
weight loss and trim abdominal fat
New research suggests that, if used properly, vibration plate exercise machines may help
you lose weight and trim the particularly harmful belly fat between the organs. In a study
presented on Friday at the European Congress on Obesity, scientists found that overweight
or obese people who regularly used the equipment in combination with a calorie restricted
diet were more successful at long-term weight loss and shedding the fat around their
abdominal organs than those who combined dieting with a more conventional fitness routine.
"These machines are increasingly found in gyms across the industrialized world and
have gathered a devoted following in some places, but there has not been any evidence that
they help people lose weight. Our study, the first to investigate the effects of vibration
in obese people, indicates it's a promising approach. It looks like these machines could
be a useful addition to a weight control package," said the study's leader, Dirk
Vissers, a physiotherapist at the Artesis University College and the University of Antwerp
in Belgium. Vissers and his colleagues studied the effects of the Power Plate in 61
overweight or obese people - mostly women - for a year. The intervention lasted six
months, after which the scientists advised all the volunteers to do the best they could
with a healthy diet and exercise regime on their own for another six months. Body
measurements, including CT scans of abdominal fat, were taken at the beginning of the
study and after three, six and 12 months. The researchers divided the volunteers into four
groups. One group was prescribed an individually calculated calorie restricted diet.
Dietician visits were scheduled every fortnight for the first three months and every month
for the second three months. The dieters were asked not to engage in any exercise for the
duration of the six-month intervention. A second group received the same diet
intervention, with the addition of a conventional fitness regime. They attended supervised
exercise classes twice a week for an hour and were urged to exercise on their own a third
time each week. The sessions included group cycling, swimming, running, step aerobics and
some general muscle strengthening exercises. A third group got the diet intervention plus
supervised vibration plate training instead of conventional exercise. They were asked not
to do any aerobic exercise during the six-month intervention phase. The physiotherapists
gradually increased the speed and intensity of the machine each week, as well as the
variety and duration of the exercises from 30 seconds for each of 10 exercises to 60
seconds for each of 22 exercises, such as squats, lunges, calf raises, push-ups and
abdominal crunches. The average time spent on the machine was 11.9 minutes per session in
the first three months and 14.2 minutes in the second three months. A fourth group got no
intervention. There were no significant differences between the groups in obesity and
abdominal, or visceral, fat at the start of the study. "Over the year, only the
conventional fitness and vibration groups managed to maintain a 5% weight loss, which is
what is considered enough to improve health," Vissers said.
Consumers more likely to identify
healthy food using traffic light nutrition labels
Consumers are five times more likely to identify healthy food when they see colourcoded
traffic light nutrition labels than when labels present the information numerically by
showing what percentage of the recommended daily nutrient intake each portion provides,
new research finds. Some governments are trying to improve the quality of nutrition
information that consumershave access to in supermarkets by adding labels to the front of
food packages, but there is no standard approach, not all products have labels and in many
countries several different systems are used. “Food manufacturers are currently
allowed to use any labelling system they prefer on the front of food packages. In some
countries this has led to a plethora of different systems appearing on supermarket
shelves, which only serves to confuse consumers more and does not allow them to quickly
and accurately identify healthy products,” said Bridget Kelly, whose study was
presented on Friday at the European Congress on Obesity. “The food industry tends to
favour the percentage daily intake method (known as Guideline Daily Amount in some
countries), but our research indicates that the traffic light system is the most effective
and that a consistent labelling approach across all food products is needed. This is
unlikely to be achieved without government regulation,” said Kelly, a nutritionist at
the Cancer Council, New South Wales in Australia.
Study in pregnant women suggests
probiotics may help ward off obesity
One year after giving birth, women were less likely to have the most dangerous kind of
obesity if they had been given probiotics from the first trimester of pregnancy, found new
research that suggests manipulating the balance of bacteria in the gut may help fight
obesity. Probiotics are bacteria that help maintain a healthy bacterial balance in the
digestive tract by reducing the growth of harmful bacteria. They are part of the normal
digestive system and play a role in controlling inflammation. Researchers have for many
years been studying the potential of using probiotic supplementation to address a number
of intestinal diseases. More recently, obesity researchers have started to investigate
whether the balance of bacteria in the gut might play a role in making people fat and
whether adjusting that balance could help. "The results of our study, the first to
demonstrate the impact of probiotics-supplemented dietary counselling on adiposity, were
encouraging," said Kirsi Laitinen, a nutritionist and senior lecturer at the
University of Turku in Finland who presented her findings on Thursday at the European
Congress on Obesity. "The women who got the probiotics fared best. One year after
childbirth, they had the lowest levels of central obesity as well as the lowest body fat
percentage." "Central obesity, where overall obesity is combined with a
particularly fat belly, is considered especially unhealthy," Laitinen said. "We
found it in 25% of the women who had received the probiotics along with dietary
counselling, compared with 43% in the women who received diet advice alone." In the
study, 256 women were randomly divided into three groups during the first trimester of
pregnancy. Two of the groups received dietary counselling consistent with what's
recommended during pregnancy for healthy weight gain and optimal foetal development. They
were also given food such as spreads and salad dressings with monounsaturated and
polyunsaturated fatty acids, as well as fibre-enriched pasta and breakfast cereal to take
home. One of those groups also received daily capsules of probiotics containing
Lactobacillus and Bifidobacterium, which are the most commonly used probiotics. The other
group received dummy capsules. A third group received dummy capsules and no dietary
counselling. The capsules were continued until the women stopped exclusive breastfeeding,
up to 6 months. The researchers weighed the women at the start of the study. At the end of
the study they weighed them again and measured their waist circumference and skin fold
thickness. The results were adjusted for weight at the start of the study. Central obesity
- defined as a body mass index (BMI) of 30 or more or a waist circumference over 80
centimetres - was found in 25% of the women who had been given the probiotics as well as
diet advice. That compared with 43% of the women who got dietary counselling alone and 40%
of the women who got neither diet advice nor probiotics. The average body fat percentage
in the probiotics group was 28%, compared with 29% in the diet advice only group and 30%
in the third group.
Increased food intake alone
explains the increase in body weight in the United States
New research that uses an innovative approach to study, for the first time, the relative
contributions of food and exercise habits to the development of the obesity epidemic has
concluded that the rise in obesity in the United States since the 1970s was virtually all
due to increased energy intake. How much of the obesity epidemic has been caused by excess
calorie intake and how much by reductions in physical activity has been long debated and
while experts agree that making it easier for people to eat less and exercise more are
both important for combating it, they debate where the public health focus should be. A
study presented on Friday at the European Congress on Obesity is the first to examine the
question of the proportional contributions to the obesity epidemic by combining metabolic
relationships, the laws of thermodynamics, epidemiological data and agricultural data.
"There have been a lot of assumptions that both reduced physical activity and
increased energy intake have been major drivers of the obesity epidemic. Until now, nobody
has proposed how to quantify their relative contributions to the rise in obesity since the
1970s. This study demonstrates that the weight gain in the American population seems to be
virtually all explained by eating more calories. It appears that changes in physical
activity played a minimal role," said the study's leader, Professor Boyd Swinburn,
chair of population health and director of the World Health Organization Collaborating
Centre for Obesity Prevention at Deakin University in Australia. The scientists started by
testing 1,399 adults and 963 children to determine how many calories their bodies burn in
total under free-living conditions. The test is the most accurate measure of total calorie
burning in real-life situations. Once they had determined each person's calorie burning
rate, Swinburn and his colleagues were able to calculate how much adults needed to eat in
order to maintain a stable weight and how much children needed to eat in order to maintain
a normal growth curve. They then worked out how much Americans were actually eating, using
national food supply data (the amount of food produced and imported, minus the amount
exported, thrown away and used for animals or other non-human uses) from the 1970s and the
early 2000s. The researchers used their findings to predict how much weight they would
expect Americans to have gained over the 30-year period studied if food intake were the
only influence. They used data from a nationally representative survey (NHANES) that
recorded the weight of Americans in the 1970s and early 2000s to determine the actual
weight gain over that period.
30-year follow-up study -
'Tremendous' impact of smoking on mortality and cardiovascular disease
Non-smokers live longer and have less cardiovascular disease than those who smoke,
according to a 30-year follow-up study of 54,000 men and women in Norway. Smoking, say the
investigators, is "strongly" related to cardiovascular morbidity and mortality
from various causes. The results, presented in Stockholm at EuroPRevent 2009, reflect what
many other studies have indicated, but, says investigator Professor Haakon Meyer from the
University of Oslo and Norwegian Institute of Public Health, these results provide a
picture of the long-term, absolute "real life" risk. Behind his conclusions lies
a far-reaching follow-up study which began in 1974 with an invitation to every middle aged
man and woman (aged 35-49) living in three counties of Norway to take part in a basic
cardiovascular screening examination. The invitation had a huge response, with 91%
attending for the baseline screen. Over the next three decades deaths were recorded by
linkage to the Norwegian population registry and, between 2006 and 2008, those surviving
responded to a follow-up questionnaire. This allowed division of the participants
according to their smoking status – never-smokers, ex-smokers, current smokers of 1-9
cigarettes a day, 10-19 cigarettes a day and more than 20 cigarettes a day (the last group
referred to as "heavy smokers"). Results showed that, from the original 54,075
participants, 13,103 had died by the time of follow-up. But it was a significant finding
that, of these, 45% of the heavy-smoking men had died during the 30 years, compared to
just 18% of the never-smokers. Similarly, 33% of the heavy-smoking women had died, but
only 13% of the never-smokers. "These results show what a tremendous impact smoking
has on mortality," says Professor Meyer. "We are talking about very high numbers
of people." A similar pattern was seen in the cardiovascular incidence rates reported
in the follow-up questionnaire. In men the cumulative incidence of myocardial infarction
was 10% in never-smokers and 21% in heavy smokers; in women 4% in never-smokers and 11% in
heavy smokers. There were also strong associations found between smoking and stroke and
diabetes. "What these results show is the cumulative long-term association between
smoking and death and cardiovascular risk," says Professor Meyer. "Around
two-thirds of the middle-aged heavy-smoking men and half the heavy-smoking women had died
or had a cardiovascular disease within the next 30 years. The incidence was much lower in
never-smokers and reflects the tremendously adverse effect of smoking on health and
longevity. The difference in outcome between the never-smokers and heavy smokers was
substantial. "This study underlines the public health messages about smoking. We have
seen declines in the prevalence of smoking in developed countries, but challenges still
remain. Certain population groups – young women, immigrant communities – still
have high rates of smoking, and there's more to be done here."
Job loss can make you sick, new
study finds
In the face of rising unemployment and businesses declaring bankruptcy, a new study has
found that losing your job can make you sick. Even when people find a new job quickly,
there is an increased risk of developing a new health problem, such as hypertension, heart
disease, heart attack, stroke or diabetes as a result of the job loss. The study will be
published in the May 8 issue of Demography. "In today's economy, job loss can happen
to anybody," said Kate Strully, who conducted the research as a Robert Wood Johnson
Foundation Health and Society scholar at the Harvard School of Public Health. "We
need to be aware of the health consequences of losing our jobs and do what we can to
alleviate the negative effects." Workers who are in poor health have a 40 percent
increase in the odds of being laid off or fired, but Strully's findings go beyond sicker
people being more likely to lose their jobs. She finds that "job churning,"
defined as high rates of job loss but low unemployment, has negative health consequences
for workers who were not already sick. For those who lost their job—white or blue
collar—through no fault of their own, such as an establishment closure, the odds of
reporting fair or poor health increased by 54 percent, and among respondents with no
pre-existing health conditions, it increased the odds of a new health condition by 83
percent. Even when workers became re-employed, those workers had an increased risk of new
stress-related health conditions. Unlike the results of job loss due to an establishment
closure, when health effects were analyzed based on workers who were fired or laid off,
significant differences were found based on the workers' occupations. While being fired or
laid off or leaving a job voluntarily more than doubles the odds of a fair or poor health
report among blue-collar workers, such job displacements have no significant association
with the health reports of white-collar workers. The reasons for this disparity are
unclear based on the study results. "As we consider ways to improve health in America
during a time of economic recession and rising unemployment, it is critical that we look
beyond health care reform to understand the tremendous impact that factors like job loss
have on our health," says David R. Williams, Norman Professor of Public Health at the
Harvard School of Public Health, Professor of African and African American Studies and of
Sociology at Harvard University and staff director of the Robert Wood Johnson Foundation
Commission to Build a Healthier America. "Where and how we live, work, learn and play
have a greater impact on how healthy we are than the health care we receive."
OHSU researchers study the idling
brain
Oregon Health & Science University researchers, along with scientists at Washington
University in St. Louis, are uncovering new information about the mind by studying the
brain while it is at rest. It is believed this research will one day provide new tools for
diagnosing mental health disorders and monitoring the progress of treatments. The
researchers' latest findings are published in the journal the Public Library of Science
Computational Biology. "For years, the vast majority of scientists studying human
functional brain organization have focused on how activity changes when engaged in
specific tasks," explained Damien Fair, Ph.D., a postdoctoral research scientist in
psychiatry, OHSU School of Medicine. "However now we know there are several regions
in the brain that continue to interact while a person is supposedly at rest – sort of
like a car that idles at a stoplight. Our lab is studying these interactions, or
spontaneous brain activity, while the brain is at rest. We think that this approach will
eventually help us distinguish typical function from atypical function and therefore help
more rapidly diagnose and appropriately treat mental disorders." To observe brain
function in humans, the researchers use a form of magnetic resonance imaging (MRI) called
functional connectivity MRI. Functional connectivity MRI allows the researchers to witness
real-time brain activity as it occurs in study subjects. By studying a large group of
subjects, the researchers were able to identify regions of the brain that spontaneously
activate together while the subjects were at rest. These regions operate in tandem with
one another, and group into regional networks. "After observing a large group of
study subjects between the ages of 7 and 31, we witnessed an interesting phenomenon,"
added Fair. "Communications between brain regions seem to be localized in children,
but over time, regional communication becomes distributed across the whole brain. Despite
these differences, children's brains are still very efficient. As with the adults, the
brains in the children were still organized like a 'small world.'"
Study reveals current
multi-component vaccines may need reworking
Current strategies for designing vaccines against HIV and cancers, for instance, may
enable some components in multi-component vaccines to cancel the effect of others on the
immune system, eliminating their ability to provide protection, according to an article to
be published shortly in the Proceedings of the National Academy of Sciences (PNAS). The
authors also suggest, and successfully test, techniques that offer a solution to newly
revealed mechanisms that enable some vaccine components to outcompete others. Recognizing
molecules as part one's self versus foreign invaders is the responsibility of the immune
system. The adaptive component of that system creates a great variety of immune cells on
the hope that one will be the right shape to become activated by any invader encountered.
When one of those immune cells recognizes an invader, it expands into an army of clones
specifically selected to attack that organism. In a landmark discovery, researchers
discovered that part of the immune system selects certain, small pieces of each
disease-causing entity (or pathogen) to trigger immune cell expansion, while ignoring the
rest. Those triggering protein fragments, or peptides, are termed
"immunodominant." For many years, the field has faced three questions. How does
this selectivity evolve? Does the process always focus on the peptid fragments that will
provide the strongest immune response/protection? If not, can we make changes to useful
peptides that make them the center of the immune system's attention? One workhorse of the
adaptive system is the helper T cell, a white blood cell that partners with dendritic
cells to make careful decisions about which disease-causing peptides attract attention.
Upon encountering an invader, a dendritic cell will "swallow it," cut it up, and
carry the pieces to the nearest lymph node. Once there, major histocompatibility complex
(MHC} class II proteins inside the dendritic cells present peptides on the cell's surface
for consideration by T cells gathered there. Activated T cells begin dividing, which
greatly increase their number, until they become capable of the destroying the pathogen in
question when exposed to high enough levels of the peptide representing it. Andrea Sant,
Ph.D., professor within the David H. Smith Center for Vaccine Biology and Immunology at
the University of Rochester Medical Center, published a July 2005 article in the journal
Immunity which revealed the quality that confers immunodominance on a peptide to be the
strength and lifespan (kinetic stability) of its bond to the MHC class II protein. Kinetic
stability determines whether, in the face of competing reactions, a peptide:MHC class II
complex can accumulate at the surface of the dendritic cell, and then remain intact long
enough to sustain T cell expansion. Dr. Sant's team found that immunodominant peptides
held onto to MHC molecules ten to one hundred times longer than nondominant, or
"cryptic," peptides because they fit together better. In the years since, Sant
and colleagues have determined how the kinetic stability of the MHC:peptide bond has its
effect. In 2006, she published a study in the Journal of Experimental Medicine that found
an enzyme called human leukocyte antigen-DM opens pockets on the MHC class II molecule for
a given peptide to fit into it before the complex heads to the cell's surface to recruit T
cells. Within dendritic cells (and related cell types that present peptides to immune
cells), DM was found to favor peptides with highly stable MHC interactions, a process
dubbed "DM editing." Sant's team found kinetically stable peptide-MHC complexes
arrived at the cell surface as much as 100 times more often than cryptic peptides, and
thought DM editing was solely responsible for determining immunodominance. The current
paper found, however, that the persistence of peptide-MHC Class II bonds also determines
which peptides cause a T cell expansion after the complexes have arrived at the cell
surface, as well as through DM editing inside the cell. A peptide's persistence at the
cell surface also controls the ability of CD4 T cells to continue to expand. Importantly,
this additional level of control over immunodominance by stability was only detected when
many peptides were present, and were "competing" to see which would trigger a T
cell response.
Is dephytinization from infant
cereals beneficial to the nutrition absorption?
Cereals are considered a rich plant source of carbohydrate, proteins, vitamins, and
minerals, and are therefore are usually introduced to an infant's diet between the ages of
four and six months. However, cereals are also rich in antinutrients, which can decrease
the absorption of critical nutrients such as iron, calcium, and zinc because of their high
ability to chelate and precipitate minerals. Given the importance of an adequate intake of
minerals during infancy, Dr. Carmen Frontela and her colleagues in the University of
Murcia (Spain) tested the effect of the dephytinization of three different commercial
infant cereals on iron, calcium, and zinc bioavailability. Their study will be published
on April 28, 2009 in the World Journal of Gastroenterology In this study, Both
dephytinized and non-dephytinized infant cereals were digested using an in vitro digestion
protocol adapted to the gastrointestinal conditions of infants younger than 6 mo. Mineral
cell retention, transport, and uptake from infant cereals were measured using the soluble
fraction of the simulated digestion and the Caco-2 cells. They found that Dephytinization
of infant cereals significantly increased (P <0.05) the cell uptake efficiency (from 0.66%-6.05% to 3.93%-13%), retention (from 6.04%-16.68% to 14.75%-20.14%) and transport efficiency (from 0.14%-2.21% to 1.47%-6.02%), of iron, and the uptake efficiency (from 5.0%-35.4% to 7.3%-41.6%) and retention (from 4.05%-20.53% to 14.45%-61.3%) of zinc, whereas calcium only cell uptake showed a significant increase (P < 0.05) after removing phytate from most of the samples analyzed. A positive relationship (P < 0.05) between mineral solubility and the cell uptake and transport efficiencies was observed. This study indicated that removing phytate from infant cereals had a beneficial effect on iron and zinc bioavailability when infant cereals were reconstituted with water. The studyalso demonstrated that Caco-2 cell lines are useful tools for study of mineral absorption and simultaneously to characterize the effect of some food components on mineral intestinal absorption. This research could be relevant not only for scientists in the field of human nutrition, but also for food manufacturers and consumers.
Is it reasonable to perform
polypectomy without interruption of anticoagulation?
Currently, patients taking anticoagulants to prevent stroke and blood clots are often
recommended to stop these medications in order to perform colonoscopy with removal of
polyps. However, interruption of these medications can place patients at risk of stroke
and blood clots. A group led by Shai Friedland at the VA Palo Alto hospital in California
reported their experience removing small colon polyps without interrupting
anticoagulation. Their study will be published on April 28, 2009 in the World Journal of
Gastroenterology Two hundred and twenty five polypectomies were performed in 123 patients.
Patients followed a standardized protocol that included stopping warfarin for 36 h to
avoid supratherapeutic anticoagulation from the bowel preparation. Patients with lesions
larger than 1 cm were generally rescheduled for polypectomy off warfarin. Endoscopic clips
were routinely applied prophylactically. They reported that one patient (0.8%, 95% CI:
0.1%-4.5%) developed major post-polypectomy bleeding that required transfusion. Two others
(1.6%, 95% CI: 0.5%-5.7%) had self-limited hematochezia at home and did not seek medical
attention. The average polyp size was 5.1 ħ 2.2 mm. They announced that polypectomy can
be performed in therapeutically anticoagulated patients with lesions up to 1 cm in size
with an acceptable bleeding rate.
A potential anti-ulcer herb
medicine - Rocket 'Eruca sativa'
Gastric ulcer is an illness that affects a considerable number of people worldwide.
Although the introduction of proton-pump inhibitors to the classic anti-ulcer therapy has
revolutionized treatment of peptic ulcers and other gastrointestinal disorders, there is
still no complete cure for this disease. It has been shown that long term use of these
drugs leads to various adverse and side effects. Relapses of the malady, ineffectiveness
of different drug regimens and even resistance to drugs are emerging. Thus, there is an
urgent requirement to identify more effective and safe anti-ulcer agents. In recent years,
Rocket "Eruca sativa L." (EER), a member of the Brassicacae family, has gained
greater importance as a salad vegetable and spice, especially among Middle Eastern
populations and Europeans. It is believed that plants belonging to the Brassicacae family
possess diversified medicinal and therapeutic properties including inhibition of
tumorigenesis, anti-ulcer, and hepatoprotective activities. A research team led by Dr Syed
Rafatullah from Saudi Arabia validated the gastric anti-ulcer properties of EER on
experimentally-induced gastric secretion and ulceration in albino rats. Their study will
be published on April 28, 2009 in the World Journal of Gastroenterology. In this study,
gastric acid secretion studies were undertaken using pylorus-ligated rats. Gastric lesions
in the rats were induced by noxious chemicals including ethanol, strong alkalis,
indomethacin and hypothermic restraint stress. The levels of gastric wall mucus (GWM),
nonprotein sulfhydryls (NP?SH) and malondialdehyde (MDA) were also measured in the
glandular stomach of rats following ethanol administration. The gastric tissue was also
examined histologically. The extract was used in two doses (250 and 500 mg/kg body weight)
in all experiments. They found that the ethanolic extract of EER significantly and
dose-dependently reduced the basal gastric acid secretion, titratable acidity and ruminal
ulceration. Rocket extract significantly attenuated gastric ulceration induced by
necrotizing agents (80% ethanol, 0.2 mol/L NaOH, 25% NaCl), indomethacin and hypothermic
restraint stress. The anti-ulcer effect was further confirmed histologically. On the other
hand, the extract significantly replenished GWM and NP?SH levels, as well as the MDA level
significantly reduced by extract pretreatment. They concluded that EER extract possesses
antisecretory, cytoprotective, and anti-ulcer activities against experimentally-induced
gastric lesions. The anti-ulcer effect is possibly through prostaglandinmediated activity
and/or through its anti-secretory and antioxidant properties.
Home UVB therapy for psoriasis as
effective and safe as hospital treatment
For patients with psoriasis, treatment with ultraviolet B (UVB) at home is as effective
and as safe as conventional hospital based phototherapy, concludes a study published on
bmj.com today. Patients also find home UVB therapy less of a burden and are more satisfied
with treatment, the findings show. Psoriasis is a common, chronic inflammatory skin
condition that causes significant disability to sufferers and their families. UVB
treatment is safe and effective, but few patients in the UK ever receive it because of
limited availability and time constraints (a course of treatment typically involves
attending hospital three times each week for eight to 10 weeks). Furthermore, most
dermatologists believe that home phototherapy is inferior to hospital treatment and that
it carries more risks, despite there being no evidence to support this. So a team of
researchers in the Netherlands compared the safety and effectiveness of home phototherapy
with standard hospital based phototherapy. They identified 196 patients with psoriasis
from 14 hospital dermatology departments. Patients were randomised to receive either home
UVB phototherapy or hospital based phototherapy. The home group used a phototherapy unit
in their homes, while the hospital group received the treatment at their local hospital.
Both treatment at home and at the hospital were applied according to standard routine
practice. Disease severity after treatment was measured using recognised scoring scales.
Side effects and total cumulative dose of UVB were also recorded. Both groups completed
questionnaires to assess the burden of treatment, quality of life and patient satisfaction
for the two treatment settings.
Low blood sugar - A killer for
kidney disease patients?
Low blood sugar, or hypoglycemia, poses a serious health threat for patients with chronic
kidney disease (CKD), according to a study appearing in an upcoming issue of the Clinical
Journal of the American Society Nephrology (CJASN). The findings indicate that
hypoglycemia may account for some portion of the excess heart-related deaths seen in CKD
patients. Glucose control is the key to preventing end-stage renal disease (ESRD) in CKD
patients with diabetes. However, managing diabetes in CKD patients can be complicated, as
patients' reduced kidney function can affect how they react to anti-diabetes medications.
Difficulties with managing their diabetes can predispose CKD patients to episodes of
hypoglycemia, a condition that can cause severe health complications including dizziness,
disorientation, slurred speech, convulsions, and death. Jeffrey C. Fink, MD (University of
Maryland Medical System), Maureen F. Moen (University of Maryland School of Medicine), and
their colleagues designed a study funded by the NIDDK and an ASN Student Scholar grant to
examine the incidence of hypoglycemia among CKD patients and to determine whether the
condition might contribute to CKD patients' deaths. The researchers assessed the incidence
of hypoglycemia in CKD patients relative to non-CKD patients, both with and without
diabetes, and they examined the association of hypoglycemia with subsequent near term
deaths (one day after blood glucose measurement). Analysis included information from
243,222 individuals cared for at the Veterans Health Administration. The incidence of
hypoglycemia was higher in patients with CKD versus without, both among patients with
diabetes and among those without. The risk of hypoglycemia was highest in individuals with
both CKD and diabetes. Hypoglycemia increased patients' risk of dying in the near term.
According to the authors, there was a reduced risk of near term death in individuals with
CKD relative to those without and this attenuation in the risk of death might relate to an
increased quality of care in these patients with CKD relative to diabetic patients without
CKD. "The association of hypoglycemia with one-day mortality underscores the
significance of this metabolic disturbance in patients with diabetes and chronic kidney
disease," said Dr. Fink. While details on therapy were not included in this study,
the findings are consistent with others that have shown that putting patients on intensive
glucose-lowering medications can lead to an increased incidence of hypoglycemia and does
not prolong their survival.
Study finds link between hot
flashes and lower bone density in women
UCLA researchers and colleagues analyzed data for 2,213 women between the ages of 42 and
52 who participated in the bone sub-study of the Study of Women's Health Across the Nation
to determine whether women with vasomotor symptoms (VMS) — which include hot flashes
and night sweats — had lower bone mineral density. The researchers found that
postmenopausal women with VMS had lower lumbar and total hip bone mineral density than
those without VMS. Premenopausal women and early perimenopausal women who had VMS were
found to have lower femoral neck bone mineral density than those without VMS.
UCLA scientists identify how key
protein keeps chronic infection in check
Why is the immune system able to fight off some viruses but not others, leading to
chronic, life-threatening infections like HIV and hepatitis C? A new UCLA AIDS Institute
study suggests the answer lies in a protein called interleukin-21 (IL-21), a powerful
molecule released by immune cells during chronic infection. Published May 7 in the online
edition of Science, the finding could explain how the immune system limits viral
replication, restricting a virus's spread through the body. The researchers looked at two
types of T-cells — CD4 T-cells and CD8 T-cells — which are immune cells that
play an important role in the body's response to infection. The CD4 T-cells help the
immune system by producing IL-21 during chronic infection, bolstering the CD8 T-cells'
ability to fight off the virus. "The CD4 cells are the regulators — the
generals, if you will," said principal investigator David Brooks, assistant professor
of microbiology, immunology and molecular genetics at the David Geffen School of Medicine
at UCLA. "The CD8 cells go out and kill the invaders; they're like the privates in
the field." To shed light on how CD4 T-cells help their CD8 counterparts clear
viruses, the researchers infected mice with one of two strains of a virus. They knew that
the first strain would generate a short-term infection and the second a chronic infection.
Treatment for extreme nausea,
vomiting during pregnancy
Nausea and vomiting are telltale indicators of pregnancy, affecting more than 80 percent
of future mothers. For a few moms-to-be, symptoms can become so severe that
hospitalization is required. Yet a new medication protocol, introduced by the
Sainte-Justine University Hospital Center, appears effective in improving symptoms more
quickly and provides a safer option than those previously available. The findings, which
are good news for moms and babies, are published in a recent edition of the European
Journal of Obstetrics and Gynecology and Reproductive Biology. "In 2002, we had to
quickly change the medication protocol to treat hyperemisis gravidarum (HG), or severe
nausea and vomiting of pregnancy, due to a FDA and Health Canada warnings," says
senior researcher Anick Bérard, a professor at the Université de Montréal's Faculty of
Pharmacy and director of the Research Unit on Medications and Pregnancy of the
Sainte-Justine University Hospital Center."The warning found that a previously used
anti-vomiting medication might cause adverse cardiovascular effects in mothers. We had to
quickly choose another treatment, which was safer. The current study looks back at the
data to evaluate the effectiveness of this treatment."
Cell's split personality is a major
discovery into neurological diseases
Researchers at the Université de Montreal (UdeM) and the Montreal Neurological Institute
(MNI), McGill University have discovered that cells which normally support nerve cell
(neuron) survival also play an active and major role in the death of neurons in the eye.
The findings, published this week in The Journal of Neuroscience, may lead to more
streamlined therapies for a variety of acute and chronic neurological disorders, including
glaucoma and retinal artery occlusion. In many neurodegenerative diseases, a main factor
that kills neurons is excessive levels of glutamate, the most abundant excitatory
neurotransmitter in many regions of the central nervous system (CNS). Diseases that occur
as a result of high glutamate levels include hypoxic–ischemic brain injury (stroke),
trauma, seizures, various forms of dementia and neurodegeneration. For years, the main
explanation for the toxic effects of glutamate is that it overexcites neuronal cells via
activation of glutamate receptors and thereby kills them. “The most interesting
aspect of our study and the reason we are so excited is that the pathway leading to
glutamate-induced nerve cell death involves another vital player – namely, glial
cells,” says Dr. Adriana Di Polo, neuroscientist at the UdeM. “Through careful
experimentation we now know that glutamate activates signaling pathways in glial cells
that then lead to neuronal death.”
Babies brainier than many imagine
A new study from Northwestern University shows what many mothers already know: their
babies are a lot smarter than others may realize. Though only five months old, the study's
cuties indicated through their curious stares that they could differentiate water in a
glass from solid blue material that looked very much like water in a similar glass. The
finding that infants can distinguish between solids and liquids at such an early age
builds upon a growing body of research that strongly suggests that babies are not blank
slates who primarily depend on others for acquiring knowledge. That's a common assumption
of researchers in the not too distant past. "Rather, our research shows that babies
are amazing little experimenters with innate knowledge," Susan Hespos said.
"They're collecting data all the time." Hespos, an assistant professor of
psychology at Northwestern, is lead author of the study, which will appear in the May 2009
issue of Psychological Science, a journal of the Association for Psychological Science. In
a test with one group of infants in the study, a researcher tilted a glass filled with
blue water back and forth to emphasize the physical characteristics of the substance
inside. Another group of babies looked at a glass filled with a blue solid resembling
water, which also was moved back and forth to demonstrate its physical properties. Next
all the infants were presented with test trials that alternated between the liquid or
solid being transferred between two glasses. According to the well-established
looking-time test, babies, like adults, look significantly longer at something that is
new, unexpected or unpredictable.
New evidence ties gene to
Alzheimer's
Of dozens of candidates potentially involved in increasing a person's risk for the most
common type of Alzheimer's disease that affects more than 5 million Americans over the age
of 65, one gene that keeps grabbing Johns Hopkins researchers' attention makes a protein
called neuroglobin. Adding to a growing body of evidence about the importance of this
protein for the health of the aging brain, researchers at the McKusick-Nathans Institute
of Genetic Medicine of the Johns Hopkins University School of Medicine canvassed the
genetic neighborhood of neuroglobin and, for the first time in a human population, linked
variation there with a risk for Alzheimer's. Ever so slight genetic variations between
individuals can and do influence the amounts of particular proteins that each specific
gene ultimately produces. In this case, the team has found that individuals with genetic
variations equating to less neuroglobin production have an increased risk for Alzheimer's.
"An intriguing part of this study was the high levels of neuroglobin that we found in
the Alzheimer's brain, which was exactly the opposite from what we expected," says
Dimitrios Avramopoulos, M.D., Ph.D., an associate professor in Hopkins' Institute of
Genetic Medicine and the Department of Psychiatry. Referring to data published in
Neurobiology of Aging, Avramopoulos explains that his team measured levels of gene product
in 56 different samples of human brain tissue: 30 from confirmed cases of Alzheimer's and
26 without brain disease. The scientists found that neuroglobin levels decreased with
advancing age, which, Avramopoulos points out, is consistent with risk of Alzheimer's
increasing with advancing age. They also found that levels of neuroglobin were lower in
women than in men, which is consistent with the fact that women have a slightly higher
risk of Alzheimer's. About two times as many patients in the general population with
Alzheimer's are women which, in part, can be attributed to the fact that women live longer
and therefore have more of a chance to get Alzheimer's. Having corrected for that
disparity, researchers have noted a slightly higher risk in women than in men. They were
surprised to find that neuroglobin levels were higher in the brain tissue from Alzheimer's
patients than that of the control group.
Origin of brain tumor discovered
Glioma is the most common and most serious form of brain tumors that affect adults. It has
not yet been determined which specific type of cell in the brain is the source of the
tumor, but now a research team at Uppsala University can show that glioma can start from
immature support cells. The findings are published in the scientific journal Oncogene. In
recent years it has been discussed more and more often that it is neural stem cells in the
brain that are transmuted into cancer cells and can then develop into glioma. “But
our results show that immature support cells can function as the source cells for the
tumor. We can thus establish that it does not have to be stem cells that cause
glioma,” says Nanna Lindberg, a doctoral candidate at the Department of Genetics and
Pathology, who is carrying out the study. She says that patients with malignant glioma
often die within a year of being diagnosed, since the tumor cells rapidly infiltrate
normal brain tissue and are difficult to treat. It is also common for the tumor to recur
after treatment. With a better understanding of the genesis and growth of brain tumors,
researchers will be able to identify new targets for treatment and ultimately will enhance
the chances of survival.
New clues on the link between
Heliobacter pylori and stomach cancer
Heliobacter pylori (H. pylori) infection is considered one of the most important risk
factors for stomach (or gastric) cancer with as much as 65% of all cases linked back to
the bacteria, although exactly how this occurs is not fully clear. But now researchers in
Denmark, Portugal and France, publishing in the journal Clinical Cancer Research1, show
that H. pylori infection contribution to cancer can be linked to at least three
independent molecular pathways, which, when disturbed by infection, lead to mutations in
the patients’ gastric tissues. Interestingly, this accumulation of mutations occur
only during the initial stages of infection making intervention at this stage crucial if
to prevent cancer, a particularly important information when deciding more efficient
medical approaches in those areas where antibiotic resistance and re-infection is so
widespread that question the relevance of giving treatment against infection. Despite a
drastic reduction in the number of cases, stomach cancer is still the 4th most common
cancer and the 2nd cause of cancer death in the world, with about 1 million of people
dying every year. That, only in the UK, around 8.000 new cases are diagnosed per year is
enough to reveal the magnitude of the problem. The best established risk factor for
stomach cancer is Helicobacter pylori infection with a capability to double the risk of
disease, although the more virulent H. pylori strains can push this number to as much as
30-fold. This is believed to occur because of the bacteria capacity to lead to acute
gastritis, which, if not treated, can becomes chronic and, with time, evolve to more
serious disturbances of the gastric wall as result of the chronic inflammation produced by
the infection. Still, although more than half of the world population is infected with H.
pylori only a small percentage of these individuals goes to develop cancer proving that
other factors are also important. These are known to include the environment – diet
and smoking for example – as well as the host genetic predisposition such as a
pro-inflammatory genetic profile. But despite these well recognised associations the exact
molecular mechanisms behind gastric cancer development – particularly those linked to
H. pylori infection – are far from being understood
Transistors used to detect Candida
The Nanosensors group from the URV has created a biosensor, an electrical and biological
device, which is able to selectively detect the Candida albicans yeast in very small
quantities of only 50 cfu/ml (colony-forming units per millilitre). "The technique
uses field-effect transistors (electronic devices that contain an electrode source and a
draining electrode connected to a transducer) based on carbon nanotubes and with Candida
albicans-specific antibodies", Raquel A. Villamizar, lead author of the study, tells
SINC. The Candida samples, which can be obtained from blood, serum or vaginal secretions,
are placed directly on the biosensor, where the interaction between antigens and
antibodies changes the electric current of the devices. This change is recorded and makes
it possible to measure the amount of yeast present in a sample. "Thanks to the
extraordinary charge transference properties of the carbon nanotubes, the fungus detection
process is direct, fast, and does not require the use of any marker", remarks
Villamizar, who is co-author of a study that provides details of the biosensor and was
published recently in the journal Sensors and Actuators B Chemical. To date, conventional
diagnosis of Candida has been carried out using microbial cultures, serological tests, PCR
molecular biology techniques (polymerase chain reactions used to amplify DNA), or
immunoassays such as ELISA (Enzyme Linked Inmunoabsorbent Assay). These techniques require
long analysis times and sometimes give rise to false positives and negatives. ELISA also
requires the use of markers (compounds that must be added to detect the presence of yeast
by fluorescence and other techniques). The new carbon nanotubes biosensor, however,
"makes it possible to improve some of the quality parameters of the traditional
methods, for example the speed and simplicity of measurements, and it is an alternative
tool that could be used in routine sample analysis", explains Villamizar.
A study reveals unprecedented data
on circadian rhythms
In higher organisms, such as mammals, biological or circadian rhythms are generated by a
multicellular genetic clock which is located in two regions of the hypothalamus that are
connected to each other known as suprachiasmatic nuclei (SCN), containing about 10,000
neurons each. In order to generate and regulate circadian rhythms, our biological clock
needs to use the “cooperative cell behaviour” of SCN neurones. These neurons
generate self-sustained, coherent oscillations and interact in a coupled manner
–through a genetic circuit- forming a single unique rhythm (circadian rhythm) that is
very efficiently modulated by the light-darkness alternance cycle in the 24 hours of a
day. Up until now, several studies had established that arrhythmia was associated with a
lack of coordination among the periodic expression of SCN neurone proteins: in arrhythmic
animals, the expression of SCN neurone proteins is desynchronised. It was also known that
constant light is one of the triggers of arrhythmia. Neurons are only capable of
generating self-sustained and coherent oscillations (biological rhythm) if the
illumination is sufficiently low. However, when intensity is increased, this coherent
behaviour is lost and the biological rhythm is distorted: animals become arrhythmic. The
researchers of the study looked at the possibility to restore rhythmicity in the animals
under these conditions by means of fluctuations in light intensity and decided to use
mathematical modelling techniques to simulate the genetic and cell interactions of the
neuro-physiological system that regulates the biological clock. This in silico experiment
is of extraordinary interest because it has enabled researchers to find out that light
intensity fluctuations help restore rhythmicity and coherence of circadian rhythms, and
not the contrary, that is, their distortion, as could be intuitively deduced.
Research at Columbia University
Medical Center shows why certain arterial plaques can turn deadly
A common misconception about arterial plaque is that it inevitably leads to a heart attack
or a stroke. New research at Columbia University Medical Center, however, sheds light on
why so few plaques in any given individual actually cause a problem. Furthermore, the
research has identified a key protein that may promote the conversion from benign to
dangerous plaques. While a vast majority of atherosclerotic lesions are relatively
harmless, the rest – some two percent of all plaques – eventually lead to an
acute blood clot and to heart attack, sudden death or stroke. What separates the average
blood vessel plaque from those that are at high risk for triggering the development of
dangerous – even fatal – blood clots, is the "billion dollar
question," says Columbia University Medical Center's Ira Tabas, M.D., Ph.D., whose
findings are presented in the cover story of the May issue of Cell Metabolism. Dr. Tabas
believes that the real danger from the fatty deposits lies not with their size, but with
what lies underneath the surface of the deposit. Like magma underneath a volcano,
rumblings in the core of a deposit, which contains dead cells, can break open the plaques.
Once the plaque ruptures, a blood clot in the lumen of the artery can form. "It is
this sudden clotting that restricts blood flow and can cause a heart attack, stroke, or
sudden cardiac death," Dr. Tabas says. "Just about everybody in our society has
atherosclerosis by the time we reach 20," Dr. Tabas added. "So the wave of the
future in treating atherosclerosis will be in preventing harmless lesions in young people
from becoming dangerous ones, or soothing dangerous plaques so they don't rupture as we
age." The best way to do that is unclear at the moment. Volatile plaques are
complicated, and there are likely many things that lead to instability and rupture. But a
graveyard – or necrotic core – of dead cells inside the plaque undoubtedly
contributes, Dr. Tabas says, because substances released by the dead cells tend to weaken
the cap covering the lesion and thereby trigger clot formation. The research by Dr. Tabas'
lab found that when a specific gene was deleted in two separate strains of
atherosclerosis-prone mice, the dangerous plaques were much smaller. The gene encodes a
protein that is part of a cell stress reaction that can lead to cell death. The work
raises the possibility that drugs designed to quiet this form of cellular stress might be
useful in treating heart disease, which is the number one killer in the United States and
becoming more prevalent.
Does new swine flu virus kill by
causing a 'cytokine storm'?
The swine flu outbreak that began in Mexico and continues to spread around the globe may
be particularly dangerous for young, otherwise healthy adults because it contains genetic
components of the H5N1 avian influenza virus, which can induce a "cytokine
storm," in which a patient's hyper-activated immune system causes potentially fatal
damage to the lungs. Research studies and review articles exploring the regulation of
cytokine responses in the lung and how infection-related dysregulation can cause a
cytokine storm have been published in Viral Immunology, a peer-reviewed journal published
by Mary Ann Liebert, Inc. (www.liebertpub.com/vim). A cytokine storm occurs when the
body's immune system over-reacts to an intruder, such as a virus, by producing high levels
of cytokines, which are signaling chemicals that help mobilize immune cells capable of
removing infectious agents from the body. When too many cytokines are produced, they can
stimulate an inflammatory response in which the accumulation of immune cells and fluid at
the site of infection may prevent affected tissues and organs such as the lungs from
functioning properly and may even cause death. H5N1 avian influenza virus—parts of
which are present in the Mexican H1N1 swine flu virus causing the current
outbreak—tend to cause an unusually high proportion of deaths among healthy young
adults with well-functioning immune systems who become infected, most likely due to this
cytokine storm phenomenon. The Spanish influenza pandemic of 1918, for example, was
particularly deadly for young healthy adults.
3T MRI Detects “Early”
Breast Cancer Not Seen on Mammography and Sonography
3T MRI, a powerful tool for evaluating patients with a high risk of having breast cancer,
can detect a significant number of lesions not found on mammography and sonography,
according to a study performed at the University of Toledo Medical Center, Toledo, OH. The
study included 434 women who underwent mammography, sonography and 3T MRI for the
detection of malignant breast lesions—all women were at high risk. Results showed
that 3T MRI detected 66/66 malignant lesions; mammography detected 54/66 malignant
lesions; and sonography detected 57/66 malignant lesions. “3T MRI depicted a
significantly higher number of malignant tumors of the breast than mammography and
sonography,” said Haitham Elsamaloty, MD, lead author of the study. “Our study
detected ‘early’ breast cancer (lesions as small as 4 mm) in size and also
identified malignant lesions that were only detected by MRI and confirmed by MRI guided
biopsy. These crucial findings led to a significant change in patient management in 18.2%
of the cases in our study. “Our study suggests an important role for 3T MRI in such
high risk groups for an early diagnosis of breast cancer and better accuracy in evaluating
the extent of disease—a crucial factor in appropriate therapy planning,” said
Dr. Elsamaloty.
Theory shows mechanism behind
delayed development of antibiotic resistance
Inhibiting the "drug efflux pumps" in bacteria, which function as their defence
mechanisms against antibiotics, can mask the effect of mutations that have led to
resistance in the form of low-affinity drug binding to target molecules in the cell. This
is shown by researchers at Uppsala University in a new study that can provide clues to how
the development of resistance to antibiotics in bacteria can be delayed. The introduction
of antibiotics as drugs in the treatment of bacterial infections in the post-WWII years
was a revolutionized medicine, and dramatically improved the health condition on a global
scale. Now, 60 years later, growing antibiotic resistance among pathogens has heavily
depleted the arsenal of entailed effective antibiotic drugs. Antibiotics function by
attacking vital molecules in bacteria. Bacteria, in turn, protect themselves either by
using "drug efflux pumps" for antibiotics or through mutations that reduce the
binding of the antibiotic to its target molecules inside the bacteria cell. Through these
changes, bacteria develop resistance to antibiotics. The new study is published in the
journal Proceedings of the National Academy of Sciences in the US. Professor Mċns
Ehrenberg's research team at Uppsala University has shown experimentally and theoretically
explained how the inhibition of these drug efflux pumps can completely mask the resistance
effect of mutations that reduce the affinity of antibiotics to their target molecules in
the bacteria cell. The effect of the mutations is entirely hidden when the pumps are
unable to remove the antibiotic sufficiently quickly in relation to the dilution of the
antibiotic through cell growth and cell division.
Swine flu genes dissimilar to past
pandemics
Some genetic markers of influenza infection severity have been identified from past
outbreaks. Researchers have failed to find most of these markers, described in the open
access journal BMC Microbiology, in samples of the current swine-flu strain. Jonathan
Allen and Tom Slezak from Lawrence Livermore National Laboratory, America, published their
analysis identifying 34 conserved amino acid markers from past pandemic flu strains two
weeks ago. They have since studied sequences from the new virus and found that only about
half of their 34 markers are present. Slezak said, “This lack of similarity does not
necessarily mean that the current H1N1 virus is not going to be a major problem, but it
does suggest that it lacks many of the attributes that have made previous outbreaks
deadly”. The researchers stress that, although their work appears to suggest that the
current virus may not be as dangerous as feared, more studies are required before any firm
conclusions can be drawn.
Hebrew University researchers
discover method to neutralize tumor growth in embryonic stem cell therapy
Researchers at the Hebrew University of Jerusalem have discovered a method to potentially
eliminate the tumor-risk factor in utilizing human embryonic stem cells. Their work paves
the way for further progress in the promising field of stem cell therapy. Human embryonic
stem cells are theoretically capable of differentiation to all cells of the mature human
body (and are hence defined as "pluripotent"). This ability, along with the
ability to remain undifferentiated indefinitely in culture, make regenerative medicine
using human embryonic stem cells a potentially unprecedented tool for the treatment of
various diseases, including diabetes, Parkinson's disease and heart failure. A major
drawback to the use of stem cells, however, remains the demonstrated tendency of such
cells to grow into a specific kind of tumor, called teratoma, when they are implanted in
laboratory experiments into mice. It is assumed that this tumorigenic feature will be
manifested upon transplantation to human patients as well. The development of tumors from
embryonic stem cells is especially puzzling given that these cells start out as completely
normal cells. A team of researchers at the Stem Cell Unit in the Department of Genetics at
the Silberman Institute of Life Sciences at the Hebrew University has been working on
various approaches to deal with this problem.
Lactate test made easy
Performance athletes need to know their blood lactate level. It indicates how much lactic
acid has collected in their blood as a result of physical exertion and enables conclusions
to be drawn about their fitness. Professional athletes therefore regularly have to attend
performance diagnosis sessions. As they pedal a cycle ergometer at various levels of
exertion, a doctor takes blood samples from an earlobe. A special device then measures the
concentration of lactate in the blood. Such scenarios will soon be a thing of the past.
Using a miniaturized measuring system, performance and leisure athletes will in future be
able to monitor their lactate readings themselves – including during training.
Normally the analytical devices are quite big and cost several thousand euros. “We
have found a way of miniaturizing the measurement system so that it can be accommodated in
an ear clip. The results could be radioed by the ear clip to a training wristwatch or a
cellphone,” says Thomas van den Boom, group manager at the Fraunhofer Institute for
Microelectronic Circuits and Systems IMS in Duisburg. An electrochemical method is used to
measure the lactate value. In a chemical reaction, an enzyme triggers a redox flow from
the lactate which can be measured using electrodes. The measurement system, which could be
installed for example in an ear clip, consists of two microchips: the innovative
nanopotentiostat fits on a chip measuring just two by three millimeters and costs less
than one euro. “The second chip incorporates microelectrodes which we have developed
for this purpose and which we can couple with the nanopotentiostat,” explains van den
Boom. One of the microelectrodes is coated with a thin layer of gel containing the enzyme.
There are altogether three microelectrodes on the chip, which are activated by the
nanopotentiostat. Two serve the purpose of electrochemical measurement while the third
keeps the electrochemical potential constant end thus ensures a stable voltage.
Tea for the treatment of type-2
diabetes
The researchers have harvested the ingredients for the tea in Africa, totalling
approximately fifty kilos of leaves and three hundred kilos of fruit from the wild nature
of Nigeria. Afterwards the tea has been produced exactly as local healers would do so. The
recipe is quite simple: boil the leaves, young stalks and fruit and filter the liquid.
Associate professor Per Mĝlgaard and postdoc Joan Campbell-Tofte from the Department of
Medicinal Chemistry have previously tested the tea on genetically diabetic mice. The
results of the tests showed that after six weeks of daily treatment with the African tea,
combined with a low-fat diet, resulted in changes in the combination and amount of fat in
the animals' eyes and protection of the fragile pancreas of the mice. The researchers have
recently completed a four month long clinical test on 23 patients with type-2 diabetes and
are more than satisfied with the result. 'The research subjects drank 750ml of tea each
day. The cure appears to differentiate itself from other current type-2 diabetes
treatments because the tea does not initially affect the sugar content of the blood. But
after four months of treatment with tea we can, however, see a significant increase in
glucose tolerance,' said postdoc Joan Campbell-Tofte from the University of Copenhagen.
The clinical tests show another pattern in the changes in fatty acid composition with the
patients treated in comparison with the placebo group.
Probiotics may be able to help you
keep slim
Researchers from LIFE - Faculty of Life Sciences at University of Copenhagen are working
on a promising research project that seems to indicate that probiotics have a slimming
effect. Nutrition researchers from LIFE and Chr. Hansen, a Danish biotech company, are
collaborating on a groundbreaking weight management research project dubbed
"Prosat". The objective is to investigate the use of probiotics for weight
control. "With excess body weight a growing problem around the world, weight
management is indisputably a major health issue today. This project will significantly
improve our understanding of the bacterial intestinal flora's importance in individual
weight management," says Professor Arne Vernon Astrup, MD, DMSc. An internationally
acclaimed nutrition and obesity academic, Astrup today heads up the Department of Human
Nutrition at LIFE - Faculty of Life Sciences. Initial results in a previous research
project indicate that specific probiotic derivates do have an interesting satiety effect.
It is too early to draw any conclusions " However, if this project demonstrates a
link between probiotics and satiety, consumers around the world will have a groundbreaking
new, documented means to help them maintain a healthy weight balance," explains
Professor Astrup. It is the aim of Chr. Hansen and the researchers to develop
scientifically documented probiotic solutions suitable for food and nutraceutical
applications which will trigger the consumer's feeling of fullness. In this way, food
intake is likely to be reduced, thereby contributing to a healthy weight balance. The
target population is slightly overweight to standard weight individuals who want to
maintain a healthy weight balance.
Protein intake is key to weight
management after weight loss concludes the DIOGENES 8 European country dietary
intervention study
"Protein intake holds the key to effective weight maintenance after weight
loss," stated Professor Arne Astrup of the University of Copenhagen and Co-ordinator
of the EC-funded Diogenes diet and weight regain prevention study, today at the Diogenes
Symposium (Tuesday 5th May 2009, The Netherlands). Professor Astrup continued "Taking
all 8 centres together and the results from 548 adults, we are able to see that those
subjects randomised to the higher protein diet after weight loss were able to maintain
that weight loss most successfully. Some subjects randomised to the lower glycemic index
(GI) diet also had some success with weight maintenance but it was less marked than those
on the higher protein diet.” 548 adult subjects completed the study with clinical
measurements taken on three different occasions (i) before the weight loss period (when at
least 8% of initial bodyweight had to be lost); (ii) end of weight loss and prior to
dietary intervention period and (iii) end of 6 month intervention period. The aim for the
diets was a difference in protein intake of > 10 energy% and in GI of > 10 units.
Two centres provided subjects with all foods for free using a shop system and 6 centres
provided dietary instruction only to subjects. Subjects also undertook tests that have fed
into other aspects of the Diogenes study. Professor Astrup continued "This study
confirms the view that the diet chosen after weight loss does help with weight
maintenance, contrary to other recently released studies which concluded that the diet
makes no difference. We can have confidence in our findings and conclusions as each
subject was closely monitored during the study and there was a much lower drop-out rate in
the high protein group - possibly due to successful weight management during the study
period."
New trial casts doubt on role of
zinc supplements in diarrhea treatment
Zinc supplementation can be ineffective in the treatment of diarrhea. A randomised
controlled trial published in the open access journal BMC Medicine has shown that
supplementation with either zinc or zinc and copper is no more effective than placebo.
Archana Patel, from the Lata Medical Research Foundation, India, led a team of researchers
who studied the effects of the different supplements on a group of 808 children in Nagpur,
also in India. She said, “The expected beneficial effects of zinc supplementation for
acute diarrhea were not observed. Therapeutic zinc or zinc and copper supplementation may
not have a universal beneficial impact on the duration of acute diarrhea in
children”. The authors found that neither duration of diarrhoea, total stool weight,
use of oral rehydration salts nor use of intravenous fluids were affected by
supplementation. The authors said, “There could be many reasons for the lack of
effect observed in our study. Although our study controlled for baseline serum zinc
concentrations, these are not always a reliable measure of body zinc status. As such,
baseline zinc deficiency in our subjects may have affected our results. Different diarrhea
etiologies and the impact of interactions of zinc with multi-vitamins shown in previous
studies may also explain the difference between our study and others that have shown a
positive effect.”
Iron deficiency in womb may delay
brain maturation in preemies
Iron plays a large role in brain development in the womb, and new University of Rochester
Medical Center research shows an iron deficiency may delay the development of auditory
nervous system in preemies. This delay could affect babies ability to process sound which
is critical for later language development in early childhood. The study evaluated 80
infants over 18 months, testing their cord blood for iron levels and using a non-invasive
tool -- auditory brainstem-evoked response (ABR) -- to measure the maturity of the brain's
auditory nervous system soon after birth. The study found that the brains of infants with
low iron levels in their cord blood had abnormal maturation of auditory system compared to
infants with normal cord iron levels. "Sound isn't transmitted as well through the
immature auditory pathway in the brains of premature babies who are deficient in iron as
compared to premature babies who have enough iron," said Sanjiv Amin, M.D., associate
professor of Pediatrics at the University of Rochester Medical Center and author of the
abstract presented today at the Pediatric Academic Society meeting in Baltimore. "We
suspect that if the auditory neural system is affected during developmental phase, then
other parts of the brain could also be affected in the presence of iron deficiency."
As many as 20 to 30 percent of pregnant women with lower socio-economic status are iron
deficient. Iron deficiency in pregnant woman can cause anemia, a condition in which there
are not enough red blood cells to carry oxygen around the body. Anemia can cause a range
of problems in pregnancy from exhaustion to preterm labor and low birth weight. But
physicians didn't know that an iron deficiency in a fetus may also delay auditory neural
maturation. which could lead to language problems. "We are concerned by these
findings because of its potential implications for language development," Amin said.
"More study is needed to fully understand what this delay in maturation means. This
finding at least underscores an already understood need to monitor iron levels in pregnant
women."
Hypertensive kids more likely to
have learning/attention problems
Children who have high blood pressure are more likely to have learning disabilities and
attention deficit hyperactivity disorder (ADHD) than children who are not hypertensive.
They are also more likely to have a higher body mass index (BMI), an indicator of body
fat. The University of Rochester Medical Center study, which was presented in abstract
form at the Pediatric Academic Society meeting today in Baltimore, shows that children
with hypertension are four times as likely to have a learning disability and/or ADHD.
"Clinicians should be aware that these conditions commonly occur together," said
Marc Lande, M.D., a pediatric nephrologist at the University of Rochester Medical Center
and author of the abstract. "More studies investigating the potential association
between hypertension and neurocognitive deficits are definitely needed." Lande
authored a paper in the Journal of Pediatrics earlier this year that showed children with
high blood pressure are not as good at complicated, goal-directed tasks, have more working
memory problems and are not as adept at planning as their peers without hypertension. If
they are both hypertensive and obese, they are also more likely to have anxiety and
depression. The new study followed 201 children 10 to 18 years old who were referred to
specialists for high blood pressure. Of those, 100 were diagnosed with hypertension while
101 were determined to either not have hypertension or to have white coat high blood
pressure (or normal blood pressure that shoots up when nervous in an exam room). Almost 28
percent of children with hypertension had a learning disability and 20 percent had ADHD.
Some of those children had both a learning disability and ADHD, so in total, 40 percent of
children with hypertension had a learning disability and/or ADHD. Dr. Lande points out,
"This apparent association between hypertension and learning problems is particularly
important in light of the recent increase in hypertension in children in this country that
has occurred as a result of the dramatic rise in obesity."
Cigarette smoke may rob children of
needed antioxidants
Children exposed to cigarette smoke have lower levels of antioxidants, which help the body
defend itself against many biological stresses. A University of Rochester Medical Center
study looked at the levels of antioxidants versus the amount of smoke exposure in more
than 2,000 6 and 18 years old in the 2003-2004 National Health and Nutrition Examination
Survey (NHANES). The study, which was presented at the Pediatric Academic Society Meeting
in Baltimore, shows that secondhand smoke exposure is associated with lower levels of
antioxidants in children."We don't know enough yet to say that this group of children
need supplements to make up for the antioxidants they're losing, but it's always wise to
feed children an abundance of fruits and vegetables high in antioxidants and other healthy
nutrients," said Karen Wilson, M.D., M.P.H., a senior instructor of Pediatrics at the
University of Rochester Medical Center and the study's author. Antioxidants are believed
to play an important role in protecting the body's cells against free radicals, which can
damage cells. Free radicals are produced during many body processes including when we use
oxygen and respond to infections. It is not completely understood how antioxidants work
together to neutralize free radicals, but scientists continue to discover more antioxidant
compounds, including those examined in the study – vitamins E and C, folate and
beta-carotene. Children's exposure to tobacco smoke was determined by the level of
cotinine in their blood (cotinine is a byproduct of metabolizing tobacco smoke). The
higher the level of cotinine in a child's blood, the lower the antioxidant level, after
controlling for diet and supplements. The study also looked at vitamins that were not
antioxidants and found that these compounds did not seem to be reduced with smoke
exposure.
Scientists learn why the flu may
turn deadly
As the swine flu continues its global spread, researchers from the Children's Hospital of
Philadelphia, Pennsylvania, have discovered important clues about why influenza is more
severe in some people than it is in others. In their research study published online in
the Journal of Leukocyte Biology (http://www.jleukbio.org), the scientists show that the
influenza virus can actually paralyze the immune systems of otherwise healthy individuals,
leading to severe secondary bacterial infections, such as pneumonia. Furthermore, this
immunological paralysis can be long-lived, which is important to know when developing
treatment strategies to combat the virus. According to Kathleen Sullivan, M.D., Ph.D., the
senior researcher involved in the study and Chief of the Division of Allergy and
Immunology at the Children's Hospital of Philadelphia, "We have a very limited
understanding of why some people who get influenza simply have a bad cold and other people
become very sick and even die. The results of this study give us a much better sense of
the mechanisms underlying bacterial infections arising on top of the viral
infection." Sullivan and colleagues recruited pediatric patients with severe
influenza and examined the level of cytokines, which serve as the first line initiators of
immune response, in the blood plasma. Although they found elevated levels of cytokines,
they also found a decreased response of toll-like receptors, which activate immune cell
responses as a result of invading microbes. This suggests that the diminished response of
these receptors may be responsible for the paralysis of the immune system, leading to
secondary bacterial infections. The influenza patients were compared with patients with
moderate influenza, respiratory syncytial virus, and a control group of healthy
individuals. The immune paralysis appeared to be specifically a result of influenza
infection and was not seen in patients with respiratory syncytial virus. This process
might explain why one quarter of children who die from influenza, die from a bacterial
infection occurring on top of the virus. "Despite major medical advances since the
devastating flu outbreak of 1918 and 1919, influenza virus infection remains a very
serious threat," said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte
Biology, "and the current swine flu outbreak is a grim reminder of this fact. The
work by Dr. Sullivan and colleagues brings us a step closer to understanding exactly what
goes wrong in some people who get the flu, so, ultimately, physicians can develop more
effective treatment strategies."
New data analysis shows possible
link between childhood obesity and allergies
A new study indicates there may be yet another reason to reduce childhood obesity —
it may help prevent allergies. The study published in the May issue of the Journal of
Allergy and Clinical Immunology showed that obese children and adolescents are at
increased risk of having some kind of allergy, especially to a food. The study was funded
by the National Institute of Environmental Health Sciences (NIEHS) and the National
Institute of Allergy and Infectious Diseases (NIAID), both parts of the National
Institutes of Health. "We found a positive association between obesity and
allergies," said Darryl Zeldin, M.D., acting clinical director at NIEHS and senior
author on the paper. The researchers analyzed data on children and young adults ages 2
to19 from a new national dataset designed to obtain information about allergies and
asthma. "While the results from this study are interesting, they do not prove that
obesity causes allergies. More research is needed to further investigate this potential
link," Zeldin said. The study is the first to be published using new data from the
National Health and Nutrition Examination Survey (NHANES). NHANES is a large nationally
representative survey conducted by the National Center for Health Statistics, a part of
the Centers for Disease Control and Prevention. NHANES is designed to assess the health
and nutritional status of adults and children in the United States. An allergy/asthma
component was supported by NIEHS and added to the 2005? NHANES study, making it the
largest nationally representative dataset of allergy and asthma information ever assembled
in the United States. "We have all the pieces of the puzzle in this dataset,"
said Zeldin. "The allergy and asthma component of NHANES provides allergen exposure
information, allergic sensitization information, as well as disease outcome information.
There is a wealth of knowledge we will be able to gain by analyzing these data that will
be useful to allergy and asthma sufferers."
New light shed on the enigma of
salt intake and hypertension
A high salt intake has been implicated in cardiovascular disease risk for 5000 years. But
salt-sensitive hypertension still remains an enigma. Now, investigators from Germany at
the University of Erlangen, the Max Delbrück Center for Molecular Medicine (MDC)
Berlin-Buch and Regensburg, collaborating with researchers from Finland and Austria have
shed new light on the relationship between salt intake, bodily processes, and blood
pressure regulation. Within the skin, they have detected a new storage area for salt in
the body. They also found out that if the process behind this storage is defect, animals
become hypertensive (Nature Medicine, doi 10.1038/nm.1960)*. Salt (natrium chloride, NaCl)
is required for life. Herbivores (plant-eating animals) risk their lives to go to
"salt licks" and carnivores (meat-eating animals) go to salt licks to eat
herbivores in order to obtain salt.Salt is responsible for water regulation in the body.
It is taken up by the gastro-intestinal (GI) tract and, in large part, excreted by the
kidneys. However, salt is also stored in cells and in the interstitium, the area between
cells in the body. Dr. Jens Titze and colleages, among them Dominik N. Müller, Wolfgang
Derer, and Friedrich C. Luft from the Experimental and Clinical Research Center at the
MDC, could now show that a high-salt diet in rats leads to the accumulation of salt in the
interstitium in the skin. This process is carefully regulated by special white blood
cells, the macrophages. In those macrophages, the scientists found a gene regulator
(transcription factor) called TonEBP (tonicity-responsible enhancer binding protein).
TonEBP is activated in these cells in response to high salt and turns on a gene (VEGF-C -
vascular endothelial growth factor C) that controls the production of lymphatic blood
vessels. With high-salt diet the lymphatic vessels increase. The investigators also showed
that when these macrophages are depleted or if the receptor for VEGF-C is absent, the
animals are not able to "store their salt" and become hypertensive. However,
this process and its relevance to human disease are not yet completely understood..
Unprecedented use of DDT concerns
experts
A panel of experts and citizens convened to review recent studies on the link between DDT
and human health expressed concern that the current practice of spraying the pesticide
indoors to fight malaria is leading to unprecedented - and insufficiently monitored -
levels of exposure to it. Although DDT has been largely abandoned as an agricultural
pesticide worldwide, its use to combat malaria was endorsed in 2006 by the World Health
Organization (WHO) and by officials in the President's Malaria Initiative, a program led
by the U.S. Agency for International Development, which was launched by former President
George W. Bush in 2005. According to WHO, in 2006 alone there were 247 million cases of
and 880,000 deaths from malaria. Most of the deaths were of young children in Africa. In
regions where malaria is endemic, the organochlorine pesticide is now sprayed inside
buildings and homes to repel and kill the mosquitoes that spread the disease. This is
being done despite a paucity of data on the human health impacts of DDT exposure at such
high levels in currently exposed populations, according to the experts from fields ranging
from environmental health to cancer biology. After a review of nearly 500 epidemiological
studies, to be published online Monday, May 4, ahead of print in the journal Environmental
Health Perspectives, the researchers developed a consensus statement calling for increased
efforts to reduce exposure to DDT, to understand the health effects of exposure to DDT,
and to develop alternatives to using DDT so that other methods could ultimately be relied
upon for malaria control. Examples of non-chemical measures to control malaria include the
use of bed nets, draining sources of standing water or filling them up with soil, and the
rapid diagnosis and treatment of malaria cases. "We have to put our concerns in the
context of people dying of malaria," said lead author Brenda Eskenazi, UC Berkeley
professor of epidemiology and of maternal and child health at the School of Public Health.
"We know DDT can save lives by repelling and killing disease-spreading mosquitoes.
But evidence suggests that people living in areas where DDT is used are exposed to very
high levels of the pesticide. The only published studies on health effects conducted in
these populations have shown profound effects on male fertility. Clearly, more research is
needed on the health of populations where indoor residual spraying is occurring, but in
the meantime, DDT should really be the last resort against malaria rather than the first
line of defense." The researchers noted that the majority of studies on DDT have
focused on the impact on wildlife and the environment. Of the studies published on human
health, almost all have dealt with populations exposed to low, background levels of DDT.
Nevertheless, some of those studies have suggested links between DDT and cancer risk,
diabetes, developmental problems in fetuses and in children, and decreased fertility.
"Any studies conducted up to now on the human health effects from DDT exposure may
not be relevant to the populations currently exposed to the pesticide through indoor
residual spraying," said Eskenazi, who has published research on the negative impact
of DDT exposure to a child's neurodevelopment.
Researchers surprised by similar
structures in Sanfilippo syndrome and Alzheimer's disease
Researchers seeking to understand the causes of a rare genetic lysosomal storage disease,
Sanfilippo syndrome type B, were surprised to find protein aggregates, known as
neurofibrillary tangles, that are usually seen in Alzheimer's and other forms of dementia,
according to a study published May 4 in the Proceedings of the National Academy of
Sciences. The discovery, in a study conducted at the Los Angeles Biomedical Research
Institute (LA BioMed) and the University of California, Los Angeles (UCLA), means that the
childhood dementia often seen in lysosomal storage diseases may have mechanisms similar to
those found in Alzheimer's disease and other age-related dementias, which are
characterized by an abnormal accumulation of the protein, P-tau. The scientists also said
these findings mean those suffering from these rare disorders could one day benefit from
the abundance of research underway for the growing numbers of Alzheimer's patients.
Imaging study finds evidence of
brain abnormalities in toddlers with autism
Toddlers with autism appear more likely to have an enlarged amygdala, a brain area
associated with numerous functions, including the processing of faces and emotion,
according to a report in the May issue of Archives of General Psychiatry, one of the
JAMA/Archives journals. In addition, this brain abnormality appears to be associated with
the ability to share attention with others, a fundamental ability thought to predict later
social and language function in children with autism. "Autism is a complex
neurodevelopmental disorder likely involving multiple brain systems," the authors
write as background information in the article. "Converging evidence from magnetic
resonance imaging, head circumference and postmortem studies suggests that brain volume
enlargement is a characteristic feature of autism, with its onset most likely occurring in
the latter part of the first year of life." Based both on its function and studies of
changes in its structure, the amygdala has been identified as a brain area potentially
associated with autism. Matthew W. Mosconi, Ph.D., and colleagues at the University of
North Carolina at Chapel Hill conducted a magnetic resonance imaging study involving 50
autistic children and 33 control children. Participating children underwent brain scans
along with testing of certain behavioral features of autism at ages 2 and 4. This included
a measure of joint attention, which involves following another person's gaze to initiate a
shared experience. Compared to control children, those children with autism were more
likely to have amygdala enlargement both at age 2 and age 4. "These findings suggest
that, consistent with a previous report of head circumference growth rates in autism and
studies of amygdala volume in childhood, amygdala growth trajectories are accelerated
before age 2 years in autism and remain enlarged during early childhood," the authors
write. "Moreover, amygdala enlargement in 2-year-old children with autism is
disproportionate to overall brain enlargement and remains disproportionate at age 4
years."
Women more vulnerable to tobacco
carcinogens, new results show
Women may be more vulnerable than men to the cancer-causing effects of smoking tobacco,
according to new results reported this week at the European Multidisciplinary Conference
in Thoracic Oncology (EMCTO), Lugano, Switzerland. Swiss researchers studied 683 lung
cancer patients who were referred to a cancer centre in St Gallen between 2000 and 2005
and found women tended to be younger when they developed the cancer, despite having smoked
on average significantly less than men. "Our findings suggest that women may have an
increased susceptibility to tobacco carcinogens," report Dr Martin Frueh and
colleagues. Dr Enriqueta Felip from Val d'Hebron University Hospital in Barcelona, Spain,
conference co-chair, notes that the results support a growing awareness that smoking
presents greater risks to women than men. "In the early 1900s lung cancer was
reported to be rare in women, but since the 1960s it has progressively reached epidemic
proportions, becoming the leading cause of cancer deaths among women in the United
States," Dr Felip said. "Lung cancer is not only a man's disease, but women tend
to be much more aware of other cancers, such as breast cancer," she said.
"Several case-control studies seem to suggest that women are more vulnerable to
tobacco carcinogens than men." On the positive side, other research presented at the
conference suggests that women tend to do better than men after surgery to remove lung
tumors. Irish researchers led by Dr Bassel Al-Alao studied 640 patients whose
non-small-cell lung cancer was surgically removed over a 10-year period, 239 of whom were
women.They found that median survival after surgery was 2.1 years for men, and 4.7 years
for women.
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