World's first medical networking and resource portal

News & Highlights
Please make use of the search function to browse preferred content
Medical News & Updates
Apr 23
Eating berries may help protect against mental decline
A new study has found that berries seem to promote autophagy, the brain`s natural housekeeping mechanism, thereby reducing the toxic accumulation.

The protective effect of berries against inflammation has been documented in many studies. Diets supplemented with blueberries and strawberries have also been shown to improve behaviour and cognitive functions in stressed young rats.

To evaluate the protective effects of berries on brain function, specifically the ability of the brain to clear toxic accumulation, researchers from the Human Nutrition Research Center on Aging at Tufts University and University of Maryland Baltimore County recently fed rats a berry diet for 2 months and then looked at their brains after irradiation, a model for accelerated aging.

All of the rats were fed berries 2 months prior to radiation and then divided into two groups- one was evaluated after 36 hours of radiation and the other after 30 days.

"After 30 days on the same berry diet, the rats experienced significant protection against radiation compared to control," said investigator Shibu Poulose, PhD.

"We saw significant benefits to diets with both of the berries, and speculate it is due to the phytonutrients present," he noted.

The researchers looked at neurochemical changes in the brain, in particular what is known as autophagy, which can regulate the synthesis, degradation and recycling of cellular components. It is also the way in which the brain clears toxic accumulations.

"Most diseases of the brain such as Alzheimer`s and Parkinson`s have shown an increased amount of toxic protein. Berries seem to promote autophagy, the brain`s natural housekeeping mechanism, thereby reducing the toxic accumulation," said Poulose.

The researchers are currently conducting a human study in older people ages 60-75.

"We have a lot of animal work that suggests these compounds will protect the aged brain and reverse some of behavioral deficits. We are hoping it will translate to human studies as well," said Dr. Barbara Shukitt-Hale, the lead investigator conducting the human study.

Apr 23
Aspirin may help slow breast cancer growth: Study
A new study by scientists including one of an Indian origin has found that aspirin slowed the growth of breast cancer cell lines in the lab and significantly reduced the growth of tumours in mice.

The age-old headache remedy also exhibits the ability to prevent tumour cells from spreading.

Results of the study by researchers at the Veterans Affairs Medical Center in Kansas City, Mo., and the University of Kansas Medical Center, suggested that regular use of low-dose aspirin might prevent the progression of breast cancer in humans.

Anecdotal evidence indicated that breast cancer was less likely to return in women who took aspirin to lower their risk of heart attack or stroke. But the science behind this relationship is not well understood.

The VA study found that aspirin might interfere with cancer cells` ability to find an aggressive, more primordial state. In the mouse model the researchers used, cancer cells treated with aspirin formed no or only partial stem cells, which are believed to fuel the growth and spread of tumours.

Senior author Sushanta Banerjee, director of the cancer research unit and a professor at the University of Kansas Medical Center in Kansas City, Kan, said that first-line chemotherapy treatments do not destroy stem cells.

Eventually, the tumour will grow again. "If you don`t target the stemness, it is known you will not get any effect. It will relapse," said Banerjee, a professor of medicine in division of hematology and oncology.

In lab tests, aspirin blocked the proliferation of two different breast cancer lines. One of the lines tested is often called triple-negative breast cancer, a less common but more difficult treat form of the disease. "We are mainly interested in triple negative breast cancer, because the prognosis is very poor," Banerjee stated.

Triple-negative breast cancers, which will be addressed in a special thematic program at the ASBMB annual meeting, lack receptors for estrogen, progesterone and Her2. Aspirin also may improve the effectiveness of current treatments for women whose breast cancers are hormone-receptor positive.

In the team`s study, aspirin enhanced the effect of tamoxifen, the usual drug therapy for hormone-receptor positive breast cancer.

Aspirin is used in the treatment of a number of different conditions. Banerjee said its ability to attack multiple metabolic pathways is what makes it potentially useful in the fight against cancer.

Aspirin is a medicine with side effects, including gastrointestinal bleeding. Researchers will continue to explore if the positive effects of regular use of the drug outweigh the risks.

The lead author of the study, Gargi Maity, a postdoctoral fellow who works in the cancer research unit at the VA Medical Center, presented the team`s findings at the annual meeting of the American Society for Biochemistry and Molecular Biology, which is being held in conjunction with the Experimental Biology 2013 conference in Boston.

Apr 22
Good diet, exercise may help stave off dementia
Living a healthy lifestyle not only protect against heart disease and stroke, it also helps keep Alzheimer`s at bay, according to a new research.

Swedish scientists have found that the risk of dementia has declined over the past 20 years, in contrast to what had been assumed.

And they put it down to lower rates of heart disease, which results from people living more healthily and keeping fit and active.

A balanced diet, being careful about weight, stopping smoking and keeping blood pressure normal have been shown to bolster the brain.

Studies have found risk factors for heart disease in middle age speed up decline of brain function in older adults. They also showed medicines such as statins and aspirin taken for heart conditions could be key to slashing dementia rates.

The latest research from Sweden - published in the journal Neurology - offers hope that drugs with a proven safety record could be used to stave off and treat the brain disease.

Patients could routinely be given them to protect long-term against Alzheimer`s.

Chengxuan Qiu of the Ageing Research Centre, established by the Karolinska Institute and Stockholm University, said that health check-ups and cardiovascular disease prevention have improved significantly, and they now see results of this improvement reflected in the risk of developing dementia.

But the centre`s director Laura Fratiglioni warned that the reduction of dementia risk is a positive phenomenon, but it is important to remember that the number of people with dementia will continue to rise along with the increase in life expectancy.

Apr 22
More women suffer from heart diseases than men
More young women suffer from cardiovascular problems than men, heart experts have revealed.

According to British Heart Foundation (BHF) research, there are 710,000 women across the UK, aged 16-44, living with heart disease compared to 570,000 men, the Independent reported.

Professor Peter Weissberg, BHF medical director, said clear signs of heart complaints are going unnoticed by women.

"There's a great tendency for women to ignore symptoms because they think of it as a man's problem. Women are affected by heart disease and sometimes more than men," he said.

Doctors believe the higher rates among women are due in part to their susceptibility to certain rarer diseases, such as coronary artery dissection, where around eight out of ten cases are women.

They warn these rare conditions are going seriously under-researched.

Amongst the conditions which young women are prone to - and which experts say need more research - are valvular heart disease, dissection of the coronary artery and heart complications associated with lupus.

The number of young women living with cardiovascular disease has remained higher than men for several years.

In 2006 there were 760,000 women living with heart conditions, compared to 580,000 men.

It is estimated that one in every four men and one in every six women die from heart disease.

Almost 180,000 people die every year from circulatory system failures in the UK - and 91,550 of them are women.

This higher number of women is not thanks to the younger cohort, however, but largely because of the high number of fatal strokes in women over-75.

Dr Martin Landray, an epidemiologist at Oxford University, says that one reason for a knowledge gap between the sexes is that drug trials and medical research into heart conditions still struggle to include as many women as men.

Apr 20
Hookah 'not safe alternative to cigarette smoking'
Many people believe that smoking tobacco through a hookah is less harmful than smoking cigarettes.

But in a new study at UC San Francisco, researchers measuring chemicals in the blood and urine have concluded that hookah smoke contains a different - but still harmful - mix of toxins.
UCSF research chemist Peyton Jacob III, PhD, and UCSF tobacco researcher Neal Benowitz, MD, both based at San Francisco General Hospital and Trauma Center, said hookah use exposes smokers to higher levels of carbon monoxide, especially hazardous to those with heart or respiratory conditions, and to higher levels of benzene, long associated with leukemia risk.

"People want to know if it is a lesser health risk if they switch from cigarettes to smoking a water pipe on a daily basis. We found that water-pipe smoking is not a safe alternative to cigarette smoking, nor is it likely to be an effective harm-reduction strategy," Jacob said.

And compared to non-smokers, Benowitz said, "If you are smoking from a hookah daily, you are likely to be at increased risk for cancer."

Jacob said, "In addition to delivering toxic substances from the charcoal and tobacco, the heat causes chemical reactions in the mixture which produce toxic volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). Some PAHs are highly carcinogenic and can cause lung cancer."

Intake of nicotine, the addictive component of tobacco, was less with water pipe use.

The findings are published in Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.

Apr 20
Depression risk factor could be `contagious
A particular style of thinking that makes people vulnerable to depression can actually "rub off" on others, increasing their symptoms of depression six months later, a study has found.

Studies had shown that people, who respond negatively to stressful life events, interpreting the events as the result of factors they can`t change and as a reflection of their own deficiency, are more vulnerable to depression.
This "cognitive vulnerability" is such a potent risk factor for depression that it can be used to predict which individuals are likely to experience a depressive episode in the future, even if they`ve never had a depressive episode before.

Individual differences in this cognitive vulnerability seem to solidify in early adolescence and remain stable throughout adulthood, but psychological scientists Gerald Haeffel and Jennifer Hames of the University of Notre Dame predicted that it might still be malleable under certain circumstances.

The researchers hypothesized that cognitive vulnerability might be "contagious" during major life transitions, when our social environments are in flux. They tested their hypothesis using data from 103 randomly assigned roommate pairs, all of whom had just started college as freshmen.

Within one month of arriving on campus, the roommates completed an online questionnaire that included measures of cognitive vulnerability and depressive symptoms. They completed the same measures again 3 months and 6 months later; they also completed a measure of stressful life events at the two time points.

The results revealed that freshmen who were randomly assigned to a roommate with high levels of cognitive vulnerability were likely to "catch" their roommate`s cognitive style and develop higher levels of cognitive vulnerability; those assigned to roommates who had low initial levels of cognitive vulnerability experienced decreases in their own levels. The contagion effect was evident at both the 3-month and 6-month assessments.

Most importantly, changes in cognitive vulnerability affected risk for future depressive symptoms: Students who showed an increase in cognitive vulnerability in the first 3 months of college had nearly twice the level of depressive symptoms at 6 months than those who didn`t show such an increase.

The findings provide striking evidence for the contagion effect, confirming the researchers` initial hypothesis.

Based on these findings, Haeffel and Hames suggested that the contagion effect might be harnessed to help treat symptoms of depression.

According to the researchers, the results of this study indicate that it may be time to reconsider how we think about cognitive vulnerability.

The research has been published in Clinical Psychological Science, a journal of the Association for Psychological Science.

Apr 18
Male circumcision reduces bacterial infection
Removing the foreskin causes a significant shift in the bacterial community or microbiome of the penis, a new study has revealed.

Male circumcision reduces the abundance of bacteria living on the penis and might help explain why circumcision offers men some protection against HIV, according to a study led by the Translational Genomics Research Institute (TGen).
This international collaboration focused on 156 men in Rakai, Uganda - part of the world`s largest randomized-controlled trial on male circumcision.

Researchers showed that men who were circumcised as part of the study had 33.3 percent less bacteria on their penis than those who remained uncircumcised one year after the study began.

Researchers further showed that the decrease was primarily found in 12 types of bacteria, most of which were intolerant to oxygen.

Past studies have shown that circumcision reduces female-to-male HIV transmission, among other benefits.

This study suggests a possible mechanism for HIV protection - the shift in the number and type of bacteria living on the penis.

Further studies will have to be done to demonstrate that a change in the penis microbiome can help reduce the risk of HIV transmission, according to the authors.

At the same time, understanding the mechanisms that underlie the benefits of male circumcision could help to identify new intervention strategies for decreasing HIV transmission, especially for populations with high HIV prevalence and in places where male circumcision is culturally less acceptable, the study says.

"We know that male circumcision can prevent HIV and other diseases in heterosexual men, but it is important to know why," Dr. Lance Price, the Director of TGen Center for Microbiomics and Human Health and the study`s senior author said.

"We think that these dramatic changes in the penis microbiome may explain, at least in part, why male circumcision is protective," he said.

The study is published online in the journal mBio.

Apr 18
Prostate screening 'could predict nearly half of death risk'
Researchers suggest that early prostate cancer testing on men in their late forties can predict nearly half of all prostate cancer deaths.

The study was carried out by researchers from Memorial Sloan-Kettering Cancer Center, New York, where they studied the medical records of 21,277 Swedish men aged 27 to 52 over a 30 year period.

They found that 10 percent of men who had the highest level of a protein known as prostate specific antigen (PSA), levels between the ages of 45 and 49 went on to account for 44 percent of all deaths from the disease.

The findings suggest that the use of this test, under which a doctor routinely test men for warning signs of prostate cancer by monitoring levels of PSA is still unreliable and conflicting because it does not directly detect cancer and can lead to patients receiving needless treatment.

Despite the uncertainties, the study shows that PSA screening programmes can "reduce the risk of over-diagnosis whilst still enabling early cancer detection for men at highest risk of death from prostate cancer", researchers reported in the British Medical Journal.

Whether PSA screening a good idea to can save lives is the important question, but further research is needed to provide the answer.

Apr 17
Junk DNA may be behind devastating neurological diseases
UC San Francisco scientists have revealed that specific DNA once dismissed as junk plays an important role in brain development and might be involved in several devastating neurological diseases.

Their discovery in mice is likely to further fuel a recent scramble by researchers to identify roles for long-neglected bits of DNA within the genomes of mice and humans alike.

While researchers have been busy exploring the roles of proteins encoded by the genes identified in various genome projects, most DNA is not in genes. This so-called junk DNA has largely been pushed aside and neglected in the wake of genomic gene discoveries, the UCSF scientists said.

In their own research, the UCSF team studies molecules called long noncoding RNA (lncRNA, often pronounced as "link" RNA), which are made from DNA templates in the same way as RNA from genes.

"The function of these mysterious RNA molecules in the brain is only beginning to be discovered," said Daniel Lim, MD, PhD, assistant professor of neurological surgery, a member of the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research at UCSF, and the senior author of the study.

Alexander Ramos, a student enrolled in the MD/PhD program at UCSF and first author of the study, conducted extensive computational analysis to establish guilt by association, linking lncRNAs within cells to the activation of genes.

Ramos looked specifically at patterns associated with particular developmental pathways or with the progression of certain diseases. He found an association between a set of 88 long noncoding RNAs and Huntington`s disease, a deadly neurodegenerative disorder. He also found weaker associations between specific groups of long noncoding RNAs and Alzheimer`s disease, convulsive seizures, major depressive disorder and various cancers.

Unlike messenger RNA, which is transcribed from the DNA in genes and guides the production of proteins, lncRNA molecules do not carry the blueprints for proteins. Because of this fact, they were long thought to not influence a cell`s fate or actions.

Nonetheless, lncRNAs also are transcribed from DNA in the same way as messenger RNA, and they, too, consist of unique sequences of nucleic acid building blocks.

Evidence indicates that lncRNAs can tether structural proteins to the DNA-containing chromosomes, and in so doing indirectly affect gene activation and cellular physiology without altering the genetic code. In other words, within the cell, lncRNA molecules act "epigenetically" - beyond genes - not through changes in DNA.

The brain cells that the scientists focused on the most give rise to various cell types of the central nervous system. They are found in a region of the brain called the subventricular zone, which directly overlies the striatum. This is the part of the brain where neurons are destroyed in Huntington`s disease, a condition triggered by a single genetic defect.

Ramos combined several advanced techniques for sequencing and analyzing DNA and RNA to identify where certain chemical changes happen to the chromosomes, and to identify lncRNAs on specific cell types found within the central nervous system. The research revealed roughly 2,000 such molecules that had not previously been described, out of about 9,000 thought to exist in mammals ranging from mice to humans.

In fact, the researchers generated far too much data to explore on their own. The UCSF scientists created a website through which their data can be used by others who want to study the role of lncRNAs in development and disease.

The study was published online in the journal Cell Stem Cell.

Apr 17
How 'bad cholesterol' ups risk of Alzheimer's and heart disease
High levels of blood cholesterol increase the risk of both Alzheimer`s disease and heart disease, but it has been unclear exactly how cholesterol damages the brain to promote Alzheimer`s disease and blood vessels to promote atherosclerosis.

Using insights gained from studying two much rarer disorders, Down Syndrome and Niemann Pick-C disease, researchers at the Linda Crnic Institute for Down Syndrome and the Department of Neurology of the University of Colorado School of Medicine found that cholesterol wreaks havoc on the orderly process of cell division, leading to defective daughter cells throughout the body.

In a new study, Antoneta Granic, PhD, and Huntington Potter, PhD, showed that cholesterol, particularly in the LDL form, called `bad cholesterol`, causes cells in both humans and mice to divide incorrectly and distribute their already-duplicated chromosomes unequally to the next generation.

The result is an accumulation of defective daughter cells with the wrong number of chromosomes and therefore the wrong number of genes. Instead of the correct two copies of each chromosome, and thus two copies of each gene, some cells acquired three copies and some only one.

Granic and Potter`s study of the effects of cholesterol on cell division included a prominent finding of cells carrying three copies of the chromosome that encodes the amyloid peptide that is the key component of the neurotoxic amyloid filaments that accumulate in the brains of Alzheimer patients.

Human trisomy 21 cells are significant because people with Down syndrome have trisomy 21 in all of their cells from the moment of conception, and they all develop the brain pathology and many develop the dementia of Alzheimer`s disease by age 50. Earlier studies by Granic, Potter and others have shown that as many as 10 percent of cells in an Alzheimer patient, including neurons in the brain, have three copies of chromosome 21 instead of the usual two.

Thus, Alzheimer`s disease is, in some ways, a form of acquired Down syndrome. Furthermore, mutant genes that cause inherited Alzheimer`s disease cause the same defect in chromosome segregation as does cholesterol, thus indicating the presence of a common cell division problem in both familial and `sporadic` (non-familial) Alzheimer`s disease.

The new research also found trisomy 21 neurons in the brains of children with what, until now, was thought to be an unrelated neurodegenerative disease (Niemann Pick type C), caused by a mutation affecting cholesterol physiology. This result suggests that neurodegeneration itself might be linked to chromosome missegregation.

Such a model is supported by the finding of Thomas Arendt, MD, and colleagues at the University of Leipzig that 90 percent of the neuronal cell death observed at autopsy in Alzheimer patients is due to the creation and selective loss of neurons with the wrong number of chromosomes.

Identifying the specific problem caused by cholesterol will lead to completely new approaches to therapy for many human diseases, including Alzheimer`s disease, atherosclerosis and possibly cancer, all of which show signs of defective cell division.

Granic and Potter already have found a potentially simple approach to preventing cholesterol from causing cells to distribute their chromosomes unequally into their new daughter cells.

Specifically, when cells in culture were first treated with ethanol, the subsequent exposure to bad cholesterol was without effect on cell division: Each daughter cell received the correct number of chromosomes.
The new study was published this week in the on-line journal PLOS ONE.

Browse Archive