News - Week 51 - 2008
Princeton-led team finds secret
ingredient for the health of tropical rainforests
A team of researchers led by Princeton University scientists has found for the first time
that tropical rainforests, a vital part of the Earth's ecosystem, rely on the rare trace
element molybdenum to capture the nitrogen fertilizer needed to support their wildly
productive growth. Most of the nitrogen that supports the rapid, lush growth of
rainforests comes from tiny bacteria that can turn nitrogen in the air into fertilizer in
the soil.
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Study reveals effects of
unconscious exposure to advertisements
Fads have been a staple of American pop culture for decades, from spandex in the 1980s to
skinny jeans today. But while going from fad to flop may seem like the result of fickle
consumers, a new study suggests that this is exactly what should be expected for a highly
efficient, rationally evolved animal.
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Lazy eye treatment times could be
drastically reduced, new research shows
Treatment times for amblyopia — more commonly known as ‘lazy eye’ —
could be drastically reduced thanks to research carried out at The University of
Nottingham. Amblyopia is thought to affect up to 2.5 per cent of people and accounts for
around 90 per cent of all children’s eye appointments in the UK. Occlusion therapy
— patching the normal eye for lengthy periods to ‘train’ the affected eye
— is the main treatment for amblyopia. However, this method can be distressing to
children, is unpopular with parents and can adversely effect educational development. This
type of therapy has been used in various forms since 1743 and has long been considered to
only be effective up until late childhood.
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Hepatitis C Treatment Reduces the
Virus but Liver Damage Continues
Treating patients who have chronic hepatitis C and advanced liver disease with long-term
pegylated interferon significantly decreased their liver enzymes, viral levels and liver
inflammation, but the treatment did not slow or prevent the progression of serious liver
disease, a study finds. These findings come from the clinical trial, Hepatitis C Antiviral
Long-Term Treatment Against Cirrhosis (HALT-C) and are reported in the Dec. 4 issue of the
New England Journal of Medicine. HALT-C was funded by the National Institutes of Health
(NIH) with additional support from Hoffmann-La Roche Inc. "The results from HALT- C
show without question that maintenance therapy with peginterferon does not prevent
progression of liver disease among patients who have failed prior treatments," said
James Everhart, M.D., project scientist for HALT-C in the Division of Digestive Diseases
and Nutrition, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK),
the principal sponsor of HALT-C at NIH. "These findings heighten the incentive to
develop more effective drugs for patients with severe liver disease due to hepatitis
C."
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here
Production line for artificial skin
A fully automated process is set to improve the production of artificial tissue: medical
scientists can perform transplants with skin produced in the laboratory. This tissue is
also suitable for testing chemicals at a low cost without requiring animal experiments.
Some patients wish they had a second skin – for instance because their own skin has
been burnt in a severe accident. But transplanting skin is a painstaking task, and a
transplant that has to cover large areas often requires several operations. Medical
scientists have therefore been trying for a long time to grow artificial tissue. This
“artificial skin” would allow them to treat these patients better and faster.
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article here
Statin warning for pregnant women
Pregnant women or those hoping to start or extend a family should avoid using the
cholesterol-lowering drugs statins, say scientists. Current clinical guidelines already
recommend that women who are pregnant should stop taking statins but the advice is based
on the knowledge that cholesterol is essential for normal fetal development. Indeed, a
2007 study examining the risk of congenital anomalies in children of pregnant women using
statins suggested that the detrimental effects of the drugs may be restricted to
fat-soluble or 'lipophilic' statins only. But new research from The University of
Manchester has shown that even water-soluble or 'hydrophilic' statins, such as
pravastatin, can affect placental development leading to worse pregnancy outcomes.
"The rapid rise in obesity and type-2 diabetes is a major health issue and affected
individuals are often treated with statins to lower circulating cholesterol levels and
reduce the risk of heart disease," said Dr Melissa Westwood, a Senior Lecturer in
Endocrinology based at the Maternal and Fetal Health Research Centre at St Mary's
Hospital, Manchester."Given the evolving demographic profile of these conditions,
such drugs are increasingly prescribed to women of reproductive age but the actions of
statins are not limited to the regulation of cholesterol levels, as they can affect the
production of other chemicals in the body too.
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UK kidney cancer patients face
toxic, out-dated treatments with little hope of change
The body that advises the UK Department of Health is likely to rule out four kidney cancer
drugs on cost grounds, despite the fact that they represent the biggest breakthrough in
treatment of the disease in the last 25 years. Professor Eisen of Cambridge University
points out that without them there is no effective treatment for 90 percent of patients
with the disease. The only drugs currently available are toxic, barely effective and
outdated, he adds
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Rice University study finds
possible clues to epilepsy, autism
Rice University researchers have found a potential clue to the roots of epilepsy, autism,
schizophrenia and other neurological disorders. While studying the peripheral nerves of
the Drosophila, aka the fruit fly, Rice doctoral student Eric Howlett discovered an
unanticipated connection between glutamate – an amino acid and neurotransmitter in
much of the food we eat – and phosphoinositide 3-kinase (PI3K), an enzyme that,
Howlett found, regulates the activity of neurons. Howlett and his colleagues, graduate
student Curtis Chun-Jen Lin, research technician William Lavery and Michael Stern, a
professor of biochemistry and cell biology, discovered that negative feedback mediated by
PI3K regulates the excitability of neurons, an issue in a number of ailments that include
neurofibromatosis, and that a mutation in a glutamate receptor gene common to both the
fruit fly and humans has the ability to disrupt that regulatory mechanism. Howlett found
the Drosophila’s metabotropic glutamate receptor (DmGluRA) gene, when mutated,
increased the excitability of the neuron by preventing PI3K from doing its job.
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article here
Harm-reduction cigarettes are more
toxic than traditional cigarettes, UC Riverside study finds
A study by University of California, Riverside researchers shows that smoke from
harm-reduction cigarettes retains toxicity and that this toxicity can affect prenatal
development. The smoke is toxic to pre-implantation embryos and can retard growth or kill
embryonic cells at this stage of development. The researchers found, too, that mainstream
smoke and sidestream smoke from these harm-reduction cigarettes are more potent than the
corresponding smoke from traditional brands of cigarettes.
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here
Heart regenerates after infarction
-- first trials with mice
Up until today scientists assumed that the adult heart is unable to regenerate. Now,
researchers and cardiologists from the Max Delbrück Center for Molecular Medicine (MDC)
Berlin-Buch and the Charité – Universitätsmedizin Berlin (Germany) have been able
to show that this dogma no longer holds true. Dr. Laura Zelarayán and Assistant Professor
Dr. Martin W. Bergmann were able to show that the body`s own heart muscle stem cells do
generate new tissue and improve the pumping function of the heart considerably in an adult
organism, when they suppress the activity of a gene regulator known as beta-catenin in the
nucleus of the heart cells. (PNAS, online December 10, 2008, doi:
10.1073/pnas.0808393105)*. The gene regulator beta-catenin plays an important role in the
development of the heart in embyros. Dr. Zelarayán and Dr. Bergmann could now show that
beta-catenin is also important for the regeneration of the adult heart. They suppressed
this factor in the nucleus of the heart cells in mice. This way they activated heart
precursor cells (stem cells) to turn on the regeneration of heart in adult mice. Four
weeks after blocking beta-catenin, the pumping function of the heart of the animals had
improved and the mice survived an infarction much better than those animals with a
functioning beta-catenin gene. An important contribution to this project has been a
transgenic mouse line generated by Professor Walter Birchmeier`s (MDC) laboratory.
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Low-carb diets can affect dieters'
cognition skills
A new study from the psychology department at Tufts University shows that when dieters
eliminate carbohydrates from their meals, they performed more poorly on memory-based tasks
than when they reduce calories, but maintain carbohydrates. When carbohydrates were
reintroduced, cognition skills returned to normal."This study demonstrates that the
food you eat can have an immediate impact on cognitive behavior," explains Holly A.
Taylor, professor of psychology at Tufts and corresponding author of the study. "The
popular low-carb, no-carb diets have the strongest potential for negative impact on
thinking and cognition."
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Women's magazines downplay
emotional health risks of cosmetic surgery
While the emotional health implications of cosmetic surgery are still up for scientific
debate, articles in women's magazines such as the Oprah Magazine and Cosmopolitan portray
cosmetic surgery as a physically risky, but overall worthwhile option for enhancing
physical appearance and emotional health, a UBC study has found. The study, published in
Women's Health Issues journal, is the first to examine how women's magazines portray
cosmetic surgery to Canadians.
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UBC Researchers Discover Gene
Mutation that Causes Eye Cancer
A University of British Columbia geneticist has discovered a gene mutation that can cause
the most common eye cancer -- uveal melanoma. Catherine Van Raamsdonk, an assistant
professor of medical genetics in the UBC Faculty of Medicine and a team of researchers,
have discovered a genetic mutation in a gene called GNAQ that could be responsible for 45
per cent of the cases of uveal melanoma. The findings, published today in Nature, will
allow researchers to develop therapeutic interventions against some melanomas. “We
discovered that GNAQ regulates melanocyte survival,” says Van Raamsdonk. “When
the GNAQ gene is mutated it leads to unregulated growth of melanocytes. Since cancer is a
disease of unregulated cell growth, our findings led us to the discovery that a genetic
mutation of the GNAQ gene causes uveal melanoma.” Uveal melanoma is a cancer arising
from melanocytes located in the uveal tract. The uveal tract is one of the three layers
that make up the wall of the eye. A melanoma is unregulated growth of melanocytes.
Melanocytes are also found in the skin and are cells linked to a life-threatening form of
skin cancer.
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Gene therapy effective treatment
against gum disease
Scientists at the University of Michigan have shown that gene therapy can be used to
successfully stop the development of periodontal disease, the leading cause of tooth loss
in adults. The findings will be published online Dec 11 in advance of print publication in
Gene Therapy. Using gene transfer to treat life threatening conditions is not new, but the
U-M group is the first known to use the gene delivery approach to show potential in
treating chronic conditions such as periodontal disease, said William Giannobile,
professor at the U-M School of Dentistry and principal investigator on the study.
"Gene therapy has not been used in non-life threatening disease. (Periodontal
disease) is more disabling than life threatening," said Giannobile, who also directs
the Michigan Center for Oral Health Research and has an appointment in the U-M College of
Engineering. "This is so important because the next wave of improving medical
therapeutics goes beyond saving life, and moves forward to improving the quality of
life." The preclinical study offers was a collaboration with the Seattle-based
biotechnology company Targeted Genetics. In July, Targeted Genetics released human trial
results that showed the same gene therapy approach used to stop periodontal disease had
positive affects in human patients with rheumatoid arthritis, another chronic, non-life
threatening, disabling condition. The company tested 127 human subjects and showed a 30
percent improvement in pain relief, and gain of function, among other enhancements using
the gene treatment.
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Exercise Suppresses Appetite By
Affecting Appetite Hormones
A vigorous 60-minute workout on a treadmill affects the release of two key appetite
hormones, ghrelin and peptide YY, while 90 minutes of weight lifting affects the level of
only ghrelin, according to a new study. Taken together, the research shows that aerobic
exercise is better at suppressing appetite than non-aerobic exercise and provides a
possible explanation for how that happens. This line of research may eventually lead to
more effective ways to use exercise to help control weight, according to the senior
author, David J. Stensel of Loughborough University in the United Kingdom. The study,
“The influence of resistance and aerobic exercise on hunger, circulating levels of
acylated ghrelin and peptide YY in healthy males,” appears in the online edition of
The American Journal of Physiology-Regulatory, Integrative and Comparative Physiology,
published by The American Physiological Society. The authors are David R. Broom, James A.
King and David J. Stensel of Loughborough University, and Rachel L. Batterham of
University College, London.
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Late preterm births present serious
risks to newborns
More than half a million babies are born preterm in the United States each year and
preterm births are on the rise. Late preterm births, or births that occur between 34 and
36 weeks (approximately 4 to 6 weeks before the mother's due date), account for more than
70 percent of preterm births. A new study and an accompanying editorial soon to be
published in the Journal of Pediatrics investigate the serious neurological problems
associated with late preterm births.
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Light shines for potential early
cancer diagnosis technique
A Northwestern University-led research team has developed a new optical technique that
holds promise for minimally invasive screening methods for the early diagnosis of cancer.
The researchers have shown for the first time that nanoscale changes are present in cells
extremely early on in carcinogenesis. Their simple yet sensitive technique can detect
subtle abnormal changes in human colon cancer cells even when those same cells appear
normal using conventional microscopy.
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Prevalence of disordered eating
behaviors in diabetics probed
Children with diabetes are at an increased risk for developing eating disorders and
researchers want to know if it's their disease or treatment that's to blame.
"Diabetes treatment prescribes obsessive food behavior, such as carbohydrate
restriction," said Dr. Deborah Young-Hyman, pediatric psychologist in the Medical
College of Georgia's Georgia Prevention Institute. "We want to know if those
prescribed behaviors contribute to disordered eating and/or whether there are
physiological mechanisms which prevent children with diabetes from controlling their
eating behavior. For example, treatment with insulin makes you hungry and can cause you to
gain weight."
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Cellular 'brakes' may slow memory
process in aging brains
University of Florida researchers may have discovered why some brain cells necessary for
healthy memory can survive old age or disease, while similar cells hardly a hairsbreadth
away die. The discovery, published online ahead of print in the Nature publication Cell
Death & Differentiation, could help scientists understand and find solutions for
age-related memory loss. Scientists with UF's Evelyn F. and William L. McKnight Brain
Institute describe how they analyzed two neighboring regions of a tiny brain structure
called the hippocampus in rats of varying ages. They found that a recently discovered
enzyme known as PHLPP, pronounced "flip," may be silencing a vital cell-survival
protein in the region where neurons are most susceptible to damage and death. "The
question is why does one set of brain cells live and another set die when they are only
millimeters apart in the same small brain structure?" said Travis C. Jackson, a
graduate student working with Thomas C. Foster, Ph.D., the Evelyn F. McKnight chair for
research on aging and memory at UF. "We looked at an important signaling pathway that
tells cells to stay alive or die, and the enzymes that regulate that pathway. Implicated
in all this is a new protein that before a couple of years ago no one actually knew much
about." The scientists focused on the hippocampus, an anatomical region shaped
something like a curved kidney bean in mammals. The structure is widely believed to be
central to the formation of memories, as well as an important component of motivation and
emotions. A portion of it is known to be especially vulnerable to decreased cerebral blood
flow, which can occur because of stroke or circulatory problems. The same area is also one
of the earliest brain regions to show pathology associated with Alzheimer's disease.
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Scans show immune cells
intercepting parasites
Researchers may have identified one of the body's earliest responses to a group of
parasites that causes illness in developing nations. In a paper published online in Public
Library of Science Pathogens, scientists report that they tracked immune cells as they
patrolled the second-shallowest layer of the skin in an animal model. Injections of a
genetically modified form of the parasite Leishmania major caused the immune cells to turn
from their patrols and move to intercept the parasites. The same parasites are now
infecting U.S. soldiers on patrol in Iraq and Afghanistan, where sand flies, the insects
whose bites spread Leishmania, are endemic. The infections normally do not cause symptoms,
but the parasite can reactivate and cause complications during pregnancy or if the immune
system weakens, including skin sores, fever, damage to the spleen and liver and anemia.
"This is one of our most detailed looks so far at how a first responder in the immune
system scouts out pathogens," says co-author Stephen Beverley, Ph.D., the Marvin A.
Brennecke Professor and head of the Department of Molecular Microbiology at Washington
University School of Medicine in St. Louis. "Determining how the immune system reacts
is critically important for efforts to develop vaccines that protect against these
parasites." According to Beverley, what researchers learn from Leishmania also may
have applications for controlling more harmful parasites from the same family of microbes,
the trypanosomes. These include Trypanosomiasis, the cause of African sleeping sickness,
which disrupts the lymph, circulatory and nervous systems and is fatal if untreated, and
Chagas disease, which can damage the heart and the intestine in long-term infections.
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here
A special type of collagen may help
protect the brain against Alzheimer's disease
Scientists from the Gladstone Institute of Neurological Disease (GIND), UCSF, and Stanford
have discovered that a certain type of collagen, collagen VI, protects brain cells against
amyloid-beta (A? ) proteins, which are widely thought to cause Alzheimer's disease (AD).
While the functions of collagens in cartilage and muscle are well established, before this
study it was unknown that collagen VI is made by neurons in the brain and that it can
fulfill important neuroprotective functions. The team of investigators led by GIND
director Lennart Mucke, MD, reported in a recent edition of the journal Nature
Neuroscience, that collagen VI is increased in brain tissues of Alzheimer's patients.
"We first noticed the increase in collagen VI in the brain of AD mouse models, which
inspired us to look for it in the human condition and to define its role in the
disease," said Dr. Mucke. The Gladstone team had profiled changes in gene expression
using DNA microarrays, which provides an unbiased method for identifying key biological
pathways. By comparing all of the genes that are active in disease and normal tissue, one
can get valuable information on new pathways and potential therapeutic targets. The
researchers looked at the dentate gyrus, a specific area of the brain that is critical to
memory and particularly vulnerable in AD, and compared the genes that were turned on and
off in normal mice and a mouse model of AD. This analysis revealed the striking increase
in collagen VI in the brains of mice that model AD. Building on this initial finding, the
team examined brain tissue from AD patients and normal non-demented humans and found that
collagen VI expression was also higher in the AD patients. They further discovered that
the cellular source of the collagen VI in the brain was neurons, the very cells that the
disease attacks and that we all need to think and remember.
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full article here
Transplanted fat cells restore
function after spinal cord injury
Fat cells, plentiful and easily obtained from adipose tissues without discomfort and grown
under culture conditions as de-differentiated fat cells (DFAT), have been for the first
time shown to successfully differentiate into neuronal cells in in vivo tests. DFAT, with
none of the features of adipocytes, have shown potential to differentiate into
endothelial, neuronal or glial lineages, thus demonstrating their potential for a source
for cell replacement therapy to treat central nervous system disorders.
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full article here
Lack of vitamin D causes weight
gain and stunts growth in girls
Insufficient vitamin D can stunt growth and foster weight gain during puberty, according
to a new study published in the Journal of Clinical Endocrinology & Metabolism. Even
in sun-drenched California, where scientists from the McGill University Health Centre
(MUHC) and the University of Southern California conducted their study, vitamin D
deficiency was found to cause higher body mass and shorter stature in girls at the peak of
their growing spurt. While lack of vitamin D is common in adults and has been linked to
diseases such as osteoporosis, cancer and obesity, until this study, little was known
about the consequences of insufficient vitamin D in young people. The research team
measured vitamin D in girls aged 16 to 22 using a simple blood test (25-hydroxy vitamin
D). They also assessed body fat and height to determine how vitamin D deficiency could
affect young women's health. "The high prevalence of vitamin D insufficiency in young
people living in a sun-rich area was surprising," says study lead author, Richard
Kremer, co-director of the Musculoskeletal Axis of the MUHC. "We found young women
with vitamin D insufficiency were significantly heavier, with a higher body mass index and
increased abdominal fat, than young women with normal levels."
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here
Poor Sleep Quality Linked to
Postpartum Depression
Postpartum depression (PPD) can lead to poor sleep quality, recent research shows. A study
published in the current issue of the Journal of Obstetric, Gynecologic, & Neonatal
Nursing shows that depression symptoms worsen in PPD patients when their quality of sleep
declines. Sleep deprivation can hamper a mother’s ability to care for her infant, as
judgment and concentration decline. Sleep-deprived mothers also may inadvertently
compromise their infants’ sleep quality because infants often adopt their
mothers’ circadian sleep rhythms.
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Women Who Are Perceived As
Confident in Job Interviews Also Seen as Lacking Social Skills
A new study in Psychology of Women Quarterly finds that women who present themselves as
confident and ambitious in job interviews are viewed as highly competent but also lacking
social skills. Women who present themselves as modest and cooperative, while well liked,
are perceived as low on competence. By contrast, confident and ambitious male candidates
are viewed as both competent and likable and therefore are more likely to be hired as a
manager than either confident or modest women. Julie E. Phelan, Corinne A. Moss-Racusin,
and Laurie A. Rudman of Rutgers University taped both male and female applicants
interviewing to be a computer lab manager. All applicants presented themselves as
competent, but also as either confident and ambitious or modest and cooperative.
Participants then evaluated the applicants’ competence, social skills, and
hirability.
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Hot drinks help fight cold and flu
A hot drink may help reduce the symptoms of common colds and flu, according to new
research by Cardiff University’s Common Cold Centre. New research at the Centre has
found that a simple hot drink of fruit cordial can provide immediate and sustained relief
from symptoms of runny nose, cough, sneezing, sore throat, chilliness and tiredness.
Published in the December 2008 edition of the clinical journal Rhinology, the research
compared the effects of a commercially produced cordial apple and blackcurrant drink
either 'hot' or at room temperature in 30 volunteers with common cold symptoms.
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Irritable Bowel Syndrome can have
genetic Causes
Irritations of the bowel can have genetic causes. Researchers at the Institute of Human
Genetics at Heidelberg University Hospital have discovered this correlation. The causes of
what is known as irritable bowel syndrome (IBS), one of the most common disorders of the
gastrointestinal tract, are considered unclear – making diagnosis and treatment
extremely difficult. The results from Heidelberg, which were published in the prestigious
journal “Human Molecular Genetics”, improve the outlook for an effective
medication against a disease that is frequently played down as a func-tional disorder. In
Germany, approximately five million people are affected by IBS, women about twice as often
as men. But only around 20 percent of these people even consult a physician. Many patients
suffer from constipation, others from severe diarrhea, or a combination of both. The
illness affects the general condition and quality of life of these patients and often
lasts for months or even years.
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The dark chocolate version of
Father Christmas is most filling
New research at the Faculty of Life Sciences at the University of Copenhagen shows that
dark chocolate is far more filling than milk chocolate, lessening our craving for sweet,
salty and fatty foods. In other words, eating dark chocolate may be an efficient way to
keep your weight down over Christmas.
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Federal Plan to Study Risks Posed
by Nanomaterials Is Inadequate
A new report from the National Research Council finds serious weaknesses in the
government's plan for research to determine any health and environmental risks posed by
nanomaterials, which are increasingly being used in consumer goods and industry. An
effective national plan for identifying and managing potential risks is essential to the
development of and public acceptance of nanotechnology-enabled products, says the report,
which outlines what is necessary to frame a successful national strategy.
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Experienced pilots may be at risk
of DNA damage from ionizing radiation
Airline pilots who have flown for many years may be at risk of DNA damage from prolonged
exposure to cosmic ionising radiation, suggests a study published ahead of print in
Occupational and Environmental Medicine. The research team compared the rate of
chromosomal (DNA) abnormalities in blood samples taken from 83 airline pilots and 50
university faculty members from the same US city. The two groups were matched for age (35
to 56), sex (male), and smoking habit (light or non-smokers). Age and smoking are known
risk factors for cumulative DNA damage. Fifty eight of the pilots (70%) had served in the
military, and they had undertaken significantly more personal air travel than the
university staff. Both these factors would have exposed them to more ionising radiation.
The researchers were looking in particular for the number of times pairs of chromosomes
had changed places (translocations), expressed as a score per 100 cell equivalents (CE).
Chromosome translocations are a reliable indicator of cumulative DNA damage associated
with radiation exposure as they are not rapidly eliminated from the blood like other forms
of chromosomal abnormality.
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Living in multigenerational
households triples women's heart disease risk
Living in a household with several generations of relatives triples a woman's risk of
serious heart disease, suggests research published ahead of print in the journal Heart.
The researchers assessed the long term impact on health of domestic living arrangements
among almost 91,000 Japanese men and women aged between 40 and 69. None of the study
participants had been diagnosed with any serious illness, such as cancer, heart disease,
or stroke at the start of the study in 1990-4. They were quizzed about their personal and
family medical histories, perceived stress, occupation, personality, and lifestyle
factors, such as diet and exercise. They were also asked about their domestic living
arrangements and the family structure of their households. During the monitoring period,
which ended in 2004, 671 people were newly diagnosed with coronary artery disease, 339
died of coronary heart disease, and 6255 died from other causes.
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full article here
Sugar can be addictive, Princeton
scientist says
A Princeton University scientist will present new evidence today demonstrating that sugar
can be an addictive substance, wielding its power over the brains of lab animals in a
manner similar to many drugs of abuse. Professor Bart Hoebel and his team in the
Department of Psychology and the Princeton Neuroscience Institute have been studying signs
of sugar addiction in rats for years. Until now, the rats under study have met two of the
three elements of addiction. They have demonstrated a behavioral pattern of increased
intake and then showed signs of withdrawal. His current experiments captured craving and
relapse to complete the picture. "If bingeing on sugar is really a form of addiction,
there should be long-lasting effects in the brains of sugar addicts," Hoebel said.
"Craving and relapse are critical components of addiction, and we have been able to
demonstrate these behaviors in sugar-bingeing rats in a number of ways." At the
annual meeting of the American College of Neuropsychopharmacology in Scottsdale, Ariz.,
Hoebel will report on profound behavioral changes in rats that, through experimental
conditions, have been trained to become dependent on high doses of sugar. "We have
the first set of comprehensive studies showing the strong suggestion of sugar addiction in
rats and a mechanism that might underlie it," Hoebel said. The findings eventually
could have implications for the treatment of humans with eating disorders, he said. Lab
animals, in Hoebel's experiments, that were denied sugar for a prolonged period after
learning to binge worked harder to get it when it was reintroduced to them. They consumed
more sugar than they ever had before, suggesting craving and relapse behavior. Their
motivation for sugar had grown. "In this case, abstinence makes the heart grow
fonder," Hoebel said.
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full article here
1 diabetes and celiac disease
linked
Type 1 (juvenile) diabetes and celiac disease appear to share a common genetic origin,
scientists at the University of Cambridge and Barts and the London School of Medicine and
Dentistry have confirmed.
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Panic attacks linked to higher risk
of heart attacks and heart disease, especially in younger people
eople who have been diagnosed with panic attacks or panic disorder have a greater risk of
subsequently developing heart disease or suffering a heart attack than the normal
population, with higher rates occurring in younger people, according to research published
in Europe’s leading cardiology journal, the European Heart Journal [1] today
(Thursday 11 December).
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Government survey shows 38 percent
of adults and 12 percent of children use complementary and alternative medicine
Approximately 38 percent of adults in the United States aged 18 years and over and nearly
12 percent of U.S. children aged 17 years and under use some form of complementary and
alternative medicine (CAM), according to a new nationwide government survey.* This survey
marks the first time questions were included on children's use of CAM, which is a group of
diverse medical and health care systems, practices, and products such as herbal
supplements, meditation, chiropractic, and acupuncture that are not generally considered
to be part of conventional medicine. The survey, conducted as part of the 2007 National
Health Interview Survey (NHIS), an annual study in which tens of thousands of Americans
are interviewed about their health- and illness-related experiences, was developed by the
National Center for Complementary and Alternative Medicine (NCCAM), a part of the National
Institutes of Health (NIH) and the National Center for Health Statistics (NCHS), a part of
the Centers for Disease Control and Prevention (CDC). The survey included questions on 36
types of CAM therapies commonly used in the United States—10 types of provider-based
therapies, such as acupuncture and chiropractic, and 26 other therapies that do not
require a provider, such as herbal supplements and meditation. "The 2007 NHIS
provides the most current, comprehensive, and reliable source of information on Americans'
use of CAM," said Josephine P. Briggs, M.D., director of NCCAM. "These
statistics confirm that CAM practices are a frequently used component of Americans' health
care regimens, and reinforce the need for rigorous research to study the safety and
effectiveness of these therapies. The data also point out the need for patients and health
care providers to openly discuss CAM use to ensure safe and coordinated care." The
2007 survey results, released in a National Health Statistics Report by NCHS, are based on
data from more than 23,300 interviews with American adults and more than 9,400 interviews
with adults on behalf a child in their household. The 2007 survey is the second conducted
by NCCAM and NCHS—the first was done as part of the 2002 NHIS.**
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Decreased levels of binding gene
affect memory and behavior
Reducing the activity of a gene called FKBP12 in the brains of mice affected
neuron-to-neuron communication (synapse) and increased both fearful memory and obsessive
behavior, indicating the gene could provide a target for drugs to treat diseases such as
autism spectrum disorder, obsessive-compulsive disease and others, said researchers from
Baylor College of Medicine in Houston in a report in the current issue of the journal
Neuron. The protein FKBP12 regulates several important cell signaling pathways, and
decreasing its activity enhances long-term potentiation in the hippocampus, said Dr. Susan
Hamilton, chair of molecular physiology and biophysics at BCM and a senior author of the
report. (Long-term potentiation means the enhancement of the synapse or communication
between neurons.) It accomplishes this by fine-tuning a particular pathway called mTOR
signaling (mammalian target of rapamycin). The mice in whose brains the activity of the
gene was reduced had longer memories and were more likely to exhibit repetitive behaviors
than normal mice.
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Popular class of diabetes drugs
doubles risk of fractures in women
New findings out of Wake Forest University School of Medicine and the University of East
Anglia show that long-term use of a popular class of oral diabetic drugs doubles the risk
of fractures in women with type 2 diabetes. The findings appear online today on the Web
site for the Canadian Medical Association Journal and will appear in the January 6 issue.
"We knew going into this study that there was an association between
thiazolidinediones and fracture risk, however the magnitude of risk had not been
evaluated," said Sonal Singh, M.D., M.P.H., an assistant professor of internal
medicine and a co-researcher for the study. "This study shows that these agents
double the risk of fractures in women with type 2 diabetes, who are already at higher risk
before taking the therapy."In absolute terms, Singh said, if thiazolidinediones
(TZDs) are used by elderly, postmenopausal women (around 70 years) with type 2 diabetes
for one year, one additional fracture would occur among every 21 women. Among younger
women (around 56 years), use of the drugs for one year or longer would result in one
additional fracture for every 55 women. TZDs are oral medications given to control
diabetes by lowering blood sugar. The two currently available drugs in this class are
rosiglitazone, marketed as AvandiaTM by GlaxoSmithKline, and pioglitazone, marketed as
ActosTM by Takeda Pharmaceuticals.
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High Phosphorus Linked to Coronary
Calcification in Chronic Kidney Disease
For patients with moderate chronic kidney disease (CKD), higher levels of phosphorus in
the blood are associated with increased calcification of the major arteries and heart
valves—which may contribute to the increased risk of cardiovascular disease in
patients with CKD, reports a study in the Journal of the American Society of Nephrology
(JASN). "Previous studies have found that a very high level of phosphorus in the
blood can lead to cardiovascular disease and vascular calcification in dialysis
patients," comments Bryan Kestenbaum, MD, of the University of Washington in Seattle,
Washington, one of the authors of the new study. "We are now recognizing that even a
mild increase in the serum phosphorus level is associated with cardiovascular events in
people with CKD who are not on dialysis."
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Brain deletion of FK506-binding
protein enhances repetitive behaviors in mice
A new study reveals a link between dysregulation of a common signaling pathway and
repetitive behaviors similar to those associated with multiple neurological and
neurodegenerative disorders including, autism spectrum disorders, obsessive compulsive
disorder, schizophrenia and Huntington's disease. The research, published by Cell Press in
the Dec. 11 issue of the journal Neuron, identifies a critical role for a molecule linked
to immunosuppression in learning, memory and repetitive behavior and may lead to the
development of new treatments for perseverative behaviors.
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here
Overweight Siblings of Children
With Type 2 Diabetes Likely to Have Abnormal Blood Sugar Levels
Overweight siblings of children with type 2 diabetes are four times more likely to have
abnormal glucose levels compared to other overweight children. Because abnormal glucose
levels may indicate risk for diabetes or diabetes itself, these children could benefit
from screening tests and diabetes prevention education.
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Fructose metabolism more
complicated than was thought
A new University of Illinois study suggests that we may pay a price for ingesting too much
fructose. According to lead author Manabu Nakamura, dietary fructose affects a wide range
of genes in the liver that had not previously been identified. Chances are you consume
quite a bit of fructose. Most Americans do—in refined sugars such as sucrose or table
sugar (which is half fructose) and in high-fructose corn syrup, used in products as
diverse as soft drinks, protein bars, and fruit juice. But many scientists believe that
high dietary fructose contributes to the development of metabolic syndrome, a group of
risk factors that predict heart disease and Type 2 diabetes. "For this reason, it's
important for scientists to understand exactly how consuming high amounts of fructose
affects human health," said Nakamura, a U of I associate professor of food science
and human nutrition.Nakamura's lab is continuing to study the metabolism of fructose with
an eye to making recommendations about its dietary use. His study shows that the
metabolism of fructose is more complex than the data had indicated. "Our
gene-expression analysis showed that both insulin-responsive and insulin-repressive genes
are induced during this process. Our bodies can do this, but it's complicated, and we may
pay a price for it," he said. According to the scientist, most carbohydrates are
handled fairly simply by our bodies. They are converted quickly to glucose and used for
energy or stored as fat. "When we are eating, blood sugar--and insulin
production--goes up. When we sleep or fast, it goes down," he said. The process is
not so simple with fructose, he noted. "In order for fructose to be metabolized, the
body has to create both fasted and fed conditions. The liver is really busy when you eat a
lot of fructose."
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Penn Research Probes Genetic
Underpinnings of Nicotine Addiction
A new study from the Abramson Cancer Center and Department of Psychiatry in the University
of Pennsylvania School of Medicine shows that smokers who carry a particular version of a
gene for an enzyme that regulates dopamine in the brain may suffer from concentration
problems and other cognitive deficits when abstaining from nicotine – a problem that
puts them at risk for relapse during attempts to quit smoking. The findings, newly
published in the journal Molecular Psychiatry, pave the way to identify novel medications
to treat nicotine addiction.
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Genetic markers identified for
alcohol response in UCSF Gallo study
Researchers at the UCSF Ernest Gallo Clinic and Research Center have identified a region
on the human genome that appears to determine how strongly drinkers feel the effects of
alcohol and thus how prone they are to alcohol abuse. The researchers found that a DNA
sequence variation, known as a single nucleotide polymorphism (SNP), on chromosome 15 is
significantly associated with the level of response to alcohol and could signal the
genetic factors that affect alcohol abuse, according to findings published in the Dec. 8
online edition of the “Proceedings of the National Academy of Sciences.”
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Honey adds health benefits, is
natural preservative and sweetener in salad dressings
Antioxidant-rich honey is a healthy alternative to chemical additives and refined
sweeteners in commercial salad dressings, said a new University of Illinois study.
"To capitalize on the positive health effects of honey, we experimented with using
honey in salad dressings," said Nicki Engeseth, a U of I associate professor of food
chemistry. "We found that the antioxidants in honey protected the quality of the
salad dressings for up to nine months while sweetening them naturally." Engeseth's
study substituted honey for EDTA, an additive used to keep the oils in salad dressings
from oxidizing, and high-fructose corn syrup, used by many commercial salad-dressing
producers to sweeten their salad dressing recipes. "We chose clover and blueberry
honeys for the study after an analysis of the sweetening potential, antioxidant activity,
and phenolic profiles of 19 honeys with varying characteristics," said the scientist.
The dressings were also compared to a control dressing that contained ingredients found in
current commercial salad dressings, she said.
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Asthma - Commonly used medication
shows no clear benefits in children
There are no clear benefits to using long-acting beta2-agonists for treatment of asthma in
children, a new study concludes. In an overview of recent Cochrane reviews, Child Health
Field researchers report that there is currently insufficient evidence to suggest the
drugs, which are recommended to relieve the symptoms of asthma, offer any additional
benefit to conventional preventative medications.
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Anti-clotting drug thins risk to
pregnancy and surgery patients with blood disorder
Pregnancy and surgery patients with a serious blood disorder that causes excessive
clotting have responded well to treatment with a man-made anti-clotting protein. Results
from a study by researchers at Yale School of Medicine and other institutions were
presented December 6 at the Annual Meeting of the American Society of Hematology (ASH) in
San Francisco. The phase III, multi-center clinical trial focused on patients with the
blood disorder known as hereditary antithrombin deficiency. Those who received the protein
recombinant human antithrombin reported no excessive clotting during treatment or seven
days after treatment. "This is a remarkable technologic feat," said study
investigator Michael Paidas, M.D., associate professor in the Department of Obstetrics,
Gynecology & Reproductive Sciences, and director of the Women and Children's Center
for Blood Disorders at Yale. "We've shown that this genetically engineered protein
can prevent complications linked to antithrombin deficiency. Ours is the first team in the
United States to use the protein in a clinical trial with pregnant patients."
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Lab mice that exercise control may
be more normal
Purdue University scientists found that mice raised in cages may relieve stress with
behaviors associated with mice in the wild. And for researchers using lab mice, this may
mean that by allowing mice to express these behaviors they can conduct research with
animals that act and respond more naturally, hopefully making research data more reliable.
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Key to 'curing' obesity may lie in
worms that destroy their own fat
A previously unknown mutation discovered in a common roundworm holds the promise of new
treatments for obesity in humans, McGill University researchers say. Their study was
published Dec. 3 in the journal Nature, and was funded by the Canadian Cancer Society and
the Canadian Institutes of Health Research. In lean times, a normal Caenorhabditis elegans
worm goes into a form of suspended animation called "dauer" that slows its
metabolism and allows it to survive for extended periods without food. "When they go
into dauer, these worms radically alter their metabolism," said Dr. Richard Roy, a
cancer researcher at McGill's Department of Biology specializing in the control of cell
division. "They shut down everything energy-consuming, which includes foraging, cell
division and reproduction." Unlike other "hibernating" organisms, C.
elegans maintains a degree of mobility during dauer by stocking up on energy in the form
of fats – or lipids – which they store in special cells or reserves. "This
allows them to live up to six months without eating, instead of the two weeks they would
otherwise have," Roy explained. A worm with the newly discovered mutation, however,
will usually die within a week of going into dauer "These mutants somehow cannot shut
down the process of cell division, which is why we noticed them in the first place,"
Roy said. "However, that's not what kills them. They cannot adjust their metabolism
correctly. They store up their six-month lipid reserves, but as soon as they shift into
dauer they use them up within a few days. This is because they lack an enzyme that blocks
the activity of a very important triglyceride lipase. Without this regulation the lipase
burns up all the fat it encounters and destroys the worm's energy reserves."
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article here
Vitamin B1 could reverse
early-stage kidney disease in diabetes patients
Researchers at the University of Warwick have discovered high doses of thiamine –
vitamin B1 – can reverse the onset of early diabetic kidney disease. Kidney disease,
or diabetic nephropathy, develops progressively in patients with type 2 diabetes. Early
development of kidney disease is assessed by a high excretion rate of the protein albumin
from the body in the urine, known as microalbuminuria. The research is led by Dr Naila
Rabbani and Professor Paul J Thornalley at Warwick Medical School, University of Warwick,
in collaboration with researchers at the University of Punjab and Sheik Zaid Hospital,
Lahore, Pakistan. The team has discovered taking high oral doses of thiamine can
dramatically decrease the excretion of albumin and reverse early stage kidney disease in
type 2 diabetes patients.
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Study sheds light on cause of bowel
disease
Scientists have uncovered vital clues about how to treat serious bowel disorders by
studying the behaviour of cells in the colon. Researchers at the University of Edinburgh
believe a chemical messenger that is essential for developing a baby's gut in the womb
could hold the key to new treatments for inflammatory bowel disease (IBD), a condition
which affects 1 in 250 people in the UK. The team studied a chain of chemical reactions
inside colon cells, called the Hedgehog signalling pathway, which controls the way it
behaves and communicates with other cells. The researchers found that some patients with
IBD inherit a defective copy of one of the important links in this chain, a gene called
GLI1. This defective GLI1 is only half as active as normal. Additionally, the Hedgehog
pathway itself signals at lower levels than normal when the large bowel is inflamed.
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Cellular stress causes fatty liver
disease in mice
A University of Iowa researcher and colleagues at the University of Michigan have
discovered a direct link between disruption of a critical cellular housekeeping process
and fatty liver disease, a condition that causes fat to accumulate in the liver. The
findings, published in the Dec. 9 issue of the journal Developmental Cell, might open new
avenues for understanding and perhaps treating fatty liver disease, which is the most
common form of liver disease in the Western world and may affect as many as one in three
American adults. Although fatty liver itself does not necessarily cause illness, it is
associated with serious conditions like diabetes, metabolic syndrome, cirrhosis of the
liver and liver failure. The study, led by Thomas Rutkowski, Ph.D., assistant professor of
anatomy and cell biology at the UI Roy J. and Lucille A. Carver College of Medicine, and
Randal Kaufman, Ph.D., professor of biological chemistry and internal medicine at the
University of Michigan Medical School, shows that disrupted protein folding causes fatty
liver in mice. The finding is the first to demonstrate a direct link between this form of
cellular stress and abnormal fat metabolism.
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An Achilles Heel in Cancer Cells
A protein that shields tumor cells from cell death and exerts resistance to chemotherapy
has an Achilles heel, a vulnerability that can be exploited to target and kill the very
tumor cells it usually protects, researchers from the University of Illinois at Chicago
show in a new study published in the Dec. 9 issue of Cancer Cell. Akt is a signaling
protein, called a kinase, that is hyperactive in the majority of human cancers. "Akt
is perhaps the most frequently activated oncoprotein (cancer-promoting protein) in human
cancer," says Nissim Hay, professor of biochemistry and molecular genetics at the UIC
College of Medicine. Pharmaceutical companies have been trying to find ways to inhibit Akt
to improve cancer therapy, he said, but most candidate drugs have acted too broadly and
proved toxic. "One of Akt's major functions in tumor cells is promoting cell
survival," Hay said. "Tumor cells with hyperactive Akt are not only resistant to
the external stresses that can induce cell death but also to chemotherapy."
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Protein levels indicate risk of
death in some colorectal cancer patients
A pair of proteins may help explain why people with surgically removed colorectal cancer
and who are overweight, physically inactive, and follow a Western-pattern diet may have an
increased risk of dying of the disease or other causes, Dana-Farber Cancer Institute
scientists report in a new study. The researchers found that in people who have undergone
surgery for colorectal cancer, the levels of two insulin-related proteins in their blood
before diagnosis predicted their chances of dying from the cancer or other conditions.
Patients with high prediagnosis levels of insulin-like growth factor binding protein-1
(IGFBP-1) were more than half as likely to succumb to the disease; while those with high
levels of C-peptide were nearly twice as likely to die. The results are being published
online by the Journal of Clinical Oncology on Dec. 8 The study was the first to consider
whether proteins whose blood levels are influenced by lifestyle factors can be a gauge of
a patient's chances of surviving stage I-III colorectal cancer. It was designed to explore
why people with certain characteristics -- namely, obesity, physical inactivity, and an
unhealthy diet -- have an increased risk of colon cancer, cancer recurrence, and death.
Such lifestyle factors can lead to high levels of circulating insulin, a hormone that may
bind directly to colon cancer cells and spur their growth. High insulin levels also lead
to lead to numerous alterations in other blood proteins, which may influence cancer cell
growth.
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Researchers find brain cells that
are a key to learning
More than a century after Ivan Pavlov's dog was conditioned to salivate when it heard the
sound of a tone prior to receiving food, scientists have found neurons that are critical
to how people and animals learn from experience. Using a new imaging technique called Arc
catFISH, researchers from the University of Washington have visualized individual neurons
in the amygdalas of rat brains that are activated when the animals are given an
associative learning task. Associative, or Pavlovian, conditioning is a fundamental form
of learning throughout the animal kingdom and is a widely researched model for studying
plasticity, or how the circuits in the brain can change as a result of experience, said
Ilene Bernstein, senior author of a new study and a UW professor of psychology.
View full article here
Einstein researchers discover
protein that contributes to cancer spread
In an important finding published online in Developmental Cell, researchers at Albert
Einstein College of Medicine of Yeshiva University, along with collaborators at
Massachusetts Institute of Technology, have identified a protein likely responsible for
causing breast cancer to spread. Metastatic cancer occurs when cancer cells from the
original tumor travel to distant sites via the blood system. Most cancer deaths are due to
cancer that has spread to other organs. Trying to stop cancer before it metastasizes is
the main goal of cancer treatments. Upon diagnosis, 6 out of 10 breast cancer patients
have cancer that is still in its primary location making the potential discovery of a
marker for invasive cancer of tremendous value that could better inform treatment options.
Until now, early markers of metastatic breast cancer have been hard to find. However, in
the Einstein-led study, researchers have identified a protein that is a promising
candidate for a metastatic breast cancer marker.
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Selenium may prevent high
risk-bladder cancer
A study published in the December issue of Cancer Prevention Research, a journal of the
American Association for Cancer Research, suggests that selenium, a trace mineral found in
grains, nuts and meats, may aid in the prevention of high-risk bladder cancer. Researchers
from Dartmouth Medical School compared selenium levels in 767 individuals newly diagnosed
with bladder cancer to the levels of 1,108 individuals from the general population.
Findings showed an inverse association between selenium and bladder cancer among women,
some smokers and those with p53 positive bladder cancer. In the entire study population,
there was no inverse association between selenium and bladder cancer, but women (34
percent), moderate smokers (39 percent) and those with p53 positive cancer (43 percent)
had significant reductions in bladder cancer with higher rates of selenium.
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article here
Alzheimer’s disease
breakthrough
In a paper published in the latest edition of the Journal of Alzheimer’s Disease,
folate is shown to be beneficial in the screening system. Lead author, CSIRO’s Dr Ian
Macreadie says folate is already well known to have a protective effect against
Alzheimer’s disease which is believed to be caused by the loss of neurons in the
brain due to a process whereby toxic multimers of a small protein called A? are formed.
“However, a team of scientists working within CSIRO’s Preventative Health
Flagship has discovered a rapid screening system to identify inhibitors of this process.
Compounds that inhibit the formation of the toxic multimers may lead to the prevention or
delay of the disease,” Dr Macreadie says. “Although many other research groups
and drug companies around the world are trying to find compounds that act in the same way,
the advance by the Flagship team involves using live yeast with the A? protein fused to a
green fluorescent protein that comes from jellyfish.
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here
Low blood pressure in preterm
infants
Scientists from Monash University, Melbourne have shown that infants born prematurely have
lower blood pressure during sleep in the first six months of life, compared to healthy,
full-term infants. Scientists at the Ritchie Centre for Baby Health Research, Monash
Institute of Medical Research, believe this may be one reason premature infants are at an
increased risk of Sudden Infant Death Syndrome (SIDS). Chief Investigator, Associate
Professor Rosemary Horne, said that previous studies have shown that prematurely-born
babies are at a significantly increased risk of SIDS; approximately 20 percent of all SIDS
cases occur in preterm babies, though preterm babies comprise only 8-10 percent of infants
born. "It has been hypothesised that the underlying mechanism of SIDS involves a fall
in blood pressure during sleep combined with a failure of the baby to arouse from sleep
which would normally restore blood pressure," Associate Professor Horne said.
"Our study has now provided evidence as to why preterm babies are at a higher risk
for SIDS."
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Food can affect a cell in the same
way hormones do
VIB researchers connected to the Katholieke Universiteit Leuven have discovered an
important new mechanism with which cells can detect nutrients. This happens in the same
way ? and with the same effects – as when cells receive a message from a hormone.
This finding can teach us more about how food affects our body; and, furthermore, it can
form the basis for new candidate targets for medicines. Every living thing is composed of
cells ? and, via receptor proteins on their outer surface, cells communicate with each
other and with the outside world. Receptors are found on skin cells (pain and pressure
receptors, for example) as well as on the cells of other tissues and organs. By binding
with certain substances, such as hormones, the receptors pick up signals from outside the
cell. They transmit the signal to the interior of the cell, where it can induce all kinds
of reactions. Receptors can be stimulated or blocked to evoke or prevent a certain effect.
Foreign substances, such as medicines, can also bind to a receptor and cause a particular
effect. For some time now, scientists have suspected that cells can also detect the
presence of food via one or another receptor ? but no one has known how that happens.
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Discovery of new gene associated
with diabetes risk suggests link with body clock
A connection between the body clock and abnormalities in metabolism and diabetes has been
suggested in new research by an international team involving the University of Oxford, the
Wellcome Trust Sanger Institute and the MRC Epidemiology Unit in Cambridge. The
researchers have identified a gene involved in the way the body responds to the 24 hour
day-night cycle that is strongly linked to high blood sugar levels and an increased risk
of type 2 diabetes. The results of the genome-wide association scan are published in
Nature Genetics. "We have extremely strong, incontrovertible evidence that the gene
encoding melatonin receptor 1B is associated with high fasting glucose levels and
increased risk of type 2 diabetes," says Professor Mark McCarthy of the Oxford Centre
for Diabetes, Endocrinology and Metabolism at the University of Oxford. Melatonin is a
hormone that is strongly tied to control of our sleep-wake cycles, with concentrations in
the blood peaking at night-time and dipping during the day. As a result, melatonin is
implicated in conditions like jetlag and sleep disorders.
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here
Progression of retinal disease
linked to cell starvation
Rods and cones coexist peacefully in healthy retinas. Both types of cells occupy the same
layer of tissue and send signals when they detect light, which is the first step in
vision. The incurable eye disease Retinitis Pigmentosa, however, reveals a codependent
relationship between the two that can be destructive. When flawed rods begin to die,
otherwise normal cones follow them to the grave, leading to blindness. A new study might
explain why. Data published online in Nature Neuroscience Dec. 7 suggest the cones are
starving to death. As rods disappear, the structure of the retina breaks down. This might
disrupt the connections between the cones and their source of nutrients. "This is the
first study linking cone death in Retinitis Pigmentosa to a metabolic problem that
suggests starvation," says senior author Constance Cepko, an HMS professor and
investigator with Howard Hughes Medical Institute. "If we can find a way to supply
nutrients to the cones, we might be able to preserve daylight vision in patients."
Active in bright light, cones allow us to perceive color and fine details. Conversely,
rods allow us to see in dim light. The untrained eye cannot distinguish between the two
types of cells, which grow side-by-side. Both rods and cones have a protrusion that has
many membranous discs, resembling a stack of cookies. A cone stack is half the height of a
rod stack. Stacks emanating from both types of cells get clustered together, like Oreos on
a plate. The entire plate gets covered in "plastic," with the flexible plastic
reaching down to touch each stack. In the eye, this plastic consists of a giant retinal
pigment (RPE) cell, which supplies nutrients to the rods and cones on its plate.
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