Category Archives: Medicine and Health

Medicine and Health News

Neuroscientists Make Declaration On Animal Consciousness

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Scientists have officially acknowledged that birds have consciousness, and can experience emotions.

On 7/7/2012 a group of prominent neuroscientists signed a declaration supporting the view that non-human animals experience consciousness. The statement claims to be a ‘re-evaluation of previously held preconceptions’. It states that:

‘Convergent evidence indicates that non-human animals have the neuroanatomical, neurochemical and neurophysiologial substrates of conscious states, along with the capacity to exhibit intentional behaviours‘.

Unfortunately the declaration doesn’t define clearly what exactly the ‘consciousness’ they are referring to is. Instead the text switches between referring to different elements of conscious experience, such as arousal (e.g. levels of sleep and attentiveness), conscious decision making, perceptual distortions (e.g. hallucinations) and the experience of emotional states. As the concept of consciousness is a notoriously difficult one to define, the lack of an operational definition makes the declaration somewhat difficult to interpret.

A further peculiarity of the declaration is that it states something which I suspect the vast majority of scientists working in the fields of neuroscience, psychology and animal behaviour have believed for some time. Indeed I suspect a significant proportion of the ‘general public’ would accept that most animals have some level of conscious understanding, especially mammals. The declaration isn’t therefore heralding a breakthrough in scientific understanding, even if it does contradict certain religious and philosophical standpoints that propose consciousness as a uniquely human characteristic.

Despite these reservations, the declaration may prove to be of importance. It focuses on the commonalities between different animals in the neural structures supporting various conscious experiences, and discusses the implications this may have for understanding the development of consciousness through evolution. It represents an official acknowledgement that a larger range of animals experience consciousness that many may have previously believed, based off the proposition that absence of a cerebral cortex does not preclude conscious thought. Those animals considered ‘conscious’ can therefore include non-mammalian creatures such as insects and cephalopods. The declaration may hopefully lead to greater discussion of both the nature of consciousness, and the relationship between humans and other animals.  More importantly it may facilitate political changes to ensure the more humane treatment of animals.

A full text of the declaration can be found at http://fcmconference.org/img/CambridgeDeclarationOnConsciousness.pdf

Scientists discover bees that can reverse brain aging

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By Maria Panagiotidi

Scientists at Arizona State University have discovered that older honey bees can reverse brain aging when they take on nest responsibilities typically handled by much younger bees.

This finding could provide alternative interventions for the treatment of age-related dementia. Current research focuses mainly on potential new drug treatments.

The study was published in the scientific journal Experimental Gerontology by a team of scientists from ASU and the Norwegian University of Life Sciences, led by Gro Amdam. The researchers found that tricking older, foraging bees into doing social tasks inside the nest causes changes in the molecular structure of their brains.

Previous research on honey bees has found that bees that stay in the nest and take care of larvae – the baby bees – remain mentally competent. However, after a period of nursing, bees fly out looking for food and begin aging very quickly. The effects of aging are visible after two weeks in the appearance of the foraging bees (worn wings, hairless bodies) and more importantly, in their brain function. Specifically, these bees lose the ability to learn new things.

Influenced by recent studies on brain plasticity, Amdam and colleagues wanted to see what would happen if the foraging bees returned to the nest and took care of the larval babies again.

The results of the experiment were fascinating. After 10 days, about 50 percent of the older bees caring for the nest and larvae had significantly improved their ability to learn new things.

The change observed in the older bees was not just behavioural but also physiological; Amdam and colleagues discovered a change in proteins in the bees’ brains. After comparing the brains of the bees that improved to those that did not, they found that two proteins had noticeably changed: Prx6 and “chaperone” protein. Both proteins have been previously found to protect the brain against diseases such as Alzheimer’s.

This finding could lead to the development of a drug that could help older people maintain brain function. However, many years of basic research and trials will be needed before such a drug becomes commercially available.

For now, Amdam and colleagues propose that social interventions might help our brains stay younger. Since the proteins being researched in people are the same as those found in bees, it is possible that these proteins may be able to respond to specific social experiences. Further research is needed on mammals in order to confirm that the same molecular changes occur on other species’ brains.

 

Reference

Nicholas Baker, Florian Wolschin, Gro V. Amdam. Age-related learning deficits can be reversible in honeybees Apis mellifera. Experimental Gerontology, 2012; DOI: 10.1016/j.exger.2012.05.011

Coffee consumption associated with lower risk of death in older adults

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By Maria Panagiotidi

Older adults who drank coffee — caffeinated or decaffeinated — had a lower risk of death overall than others who did not drink coffee, according a study by researchers from the National Cancer Institute (NCI), part of the National Institutes of Health, and AARP. The  results of the study were published in the May 17, 2012 edition of the New England Journal of Medicine.

Coffee is one of the most widely consumed beverages worldwide, but the association between coffee consumption and the risk of death remains unclear. Neal Freedman and his colleagues examined this relationship in 229,119 men and 173,141 women who participated in the NIH-AARP Diet and Health Study. The ages of the participants varied from 50 to 71.

 

After adjusting for tobacco-smoking, alcohol consumption, and other potential confounders, the researchers found that coffee drinkers were less likely to die from heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections. No difference was found in the case of cancer. Heavier coffee intake among men was associated with increased risk of cancer death. The association, however, was only marginally statistically significant.

The researchers found that the association between coffee and reduction in risk of death increased with the amount of coffee consumed. The participants who consumed three or more cups of coffee per day had approximately a 10 percent lower risk of death. The findings were similar for caffeinated and decaffeinated coffee consumption.

It should be noted that the current study does not allow us to infer a causal relationship between coffee drinking and lower risk of death. Examining the exact nature of this relationship will be the subject of future studies.

 

Reference

Neal D. Freedman, Yikyung Park, Christian C. Abnet, Albert R. Hollenbeck, Rashmi Sinha. Association of Coffee Drinking with Total and Cause-Specific Mortality. New England Journal of Medicine, 2012; 366 (20): 1891 DOI:10.1056/NEJMoa1112010

Eating smelly foods could aid weight loss

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By Holly Rogers

Strongly scented foods encourage people to take smaller bites, a method commonly thought to help dieters with portion control, say researchers from Wageningen University, Netherlands.

Participants in the study were given control of how much custard they were served by pushing a button, as they were repeatedly exposed to different scents. The study showed that people would eat as much as 10% less pudding when they were presented with stronger or more unfamiliar smells.

“Bite size was associated with the aroma presented for that bite, and also for subsequent bites (especially the second to last bite),” said Dr Rene A de Wijk, project leader.

Generally, people will take smaller bites if a food is unfamiliar or unpleasant, to keep the amount of flavour they are exposed to as small as possible.

“Perhaps [...] there is an unconscious feedback loop using bite size to regulate the amount of flavour experienced,” said Dr de Wijk.

Previous research has shown the brain associates smaller bites with food that needs to be chewed more thoroughly, and can reduce how much is eaten in a single meal.

Understanding how altering the smell of food could fool the brain into believing the stomach is full would be a bonus for those trying to reduce their fat intake. Combined with healthy eating, it could even be worked into a plausible diet plan.

The team’s research has been published in the newly launched, open access journal, Flavour.

Reference

R. A. De Wijk, I. A. Polet, W. Boek, S. Conraad and J. H. F. Bult, Food aroma affects bite size, Flavour  (in press)

You can download the article from here: http://www.flavourjournal.com/content/1/1/3

Turmeric could help ward off Parkinson’s disease

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By Holly Rogers

Curcumin, found in turmeric, has been shown to prevent protein clumping in the brain. This clumping has been recognised as an early stage of Parkinson’s disease.

Scientists at Michigan State University have used lasers to watch proteins being rescued by curcumin, building on research released earlier this year into the mechanism of clumping.

“Our research shows that curcumin can rescue proteins from aggregation, the first steps to many debilitating diseases,” said Lisa Lapidus, co-author of the study.

KurkuminaProteins are needed to carry out most of the work done by cells, and are built through a process known as folding. If the protein does not fold fast enough, it begins to clump and bind to other proteins around it. Curcumin not only stops this binding from happening, but speeds up the folding process, lowering the chances of it starting again. However, there is still more research to be done before curcumin becomes a routine treatment.

“Curcumin’s usefulness as an actual drug may be pretty limited since it doesn’t go into the brain easily,” said Professor Lapidus. “But this kind of study showcases the technique of measuring reconfiguration and opens the door for developing drug treatments.”

Curcumin is being currently investigated for possible benefits in various clinical conditions such as Alzheimer’s disease, and some types of cancer.

Reference:

B. Ahmad and L. J. Lapidus, Curcumin Prevents Aggregation in α-synuclein by Increasing the Reconfiguration Rate, Journal of Biological Chemistry, 2012.

You can find the original article here: http://www.jbc.org/content/287/12/9193.abstract

 

Anxiety enhances sense of smell

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By Maria Panagiotidi

Anxious people have a heightened sense of smell, when it comes to sniffing out a threat, according to a new study by Elizabeth Krusemark and Wen Li from the University of Wisconsin-Madison in the US. The results of their study will be published online in the journal Chemosensory Perception.

The sense of smell is an essential tool for survival in animals. It allows them to detect, locate and identify predators in the surrounding environment. In fact, the olfactory-mediated defence system is so important in animals, that the mere presence of predator odours can evoke potent fear and anxiety responses.

Smells also evoke powerful emotional responses in humans. Krusemark and Li hypothesized that in humans, detection of a particular bad smell may signal danger of a noxious airborne substance, or a decaying object that carries disease. Also, they speculated that the level of response to the above could underlie phobias or anxiety related disorders.

The researchers tested their hypotheses by combining assessment of state-level anxiety, psychophysical testing, and functional magnetic resonance imaging (fMRI) techniques.  They recruited 14 young adult participants who were exposed to three types of odours: neutral pure odor, neutral odor mixture, and negative odor mixture. The participants were asked to detect the presence or absence of an odour in an MRI scanner. During scanning, the researchers also measured skin conductance response (a measure of arousal level), and monitored the subjects’ breathing patterns. After completing the odour detection task, the participants were asked to rate their current level of anxiety using a standardised clinical test.

The authors found that as anxiety levels rose, so did the subjects’ ability to discriminate negative odours accurately – suggesting a ‘remarkable’ olfactory acuity to threat in anxious subjects. The same pattern was found in the skin conductance results which showed that anxiety also heightened emotional arousal to smell-induced threats.

Krusemark and Li uncovered amplified communication between the sensory and emotional areas of the brain in response to negative odours, particularly in anxiety. This increased connectivity could be responsible for the heightened arousal to threats.

These findings could help researchers elucidate the aetiology of the unfortunate and debilitating symptoms that perpetuate anxiety disorders.

 

Reference:

Krusemark EA & Li W (2012). Enhanced olfactory sensory perception of threat in anxiety: an event-related fMRI study. Chemosensory Perception. DOI 10.1007/s12078-011-9111-7

You can find the article here: http://www.springerlink.com/content/a268t518p1x59v68/

Cholesterol treatment used in treatment of hepatitis C?

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By Kathryn Higgins

A molecule that is known to take up cholesterol into a cell has recently been identified to allow entry of the hepatitis C virus (HCV) into liver cells. This may lead the way for new therapies to be developed.

Hepatitis C is a disease that primarily affects the liver. It is caused by HCV, which is spread by blood-to-blood contact. Once infected, HCV can persist in the liver causing scarring and ultimately leading to liver failure or cancer. The World Health Organisation (WHO) estimates that three per cent of the world’s population (about 170 million) have hepatitis C, and although treatment is available, more effective therapies are needed. Liver transplantation is one such treatment, but infected patients find the virus attacks the new liver.

Previous studies have shown the involvement of cholesterol in HCV infection, thus it was hypothesised by researchers at the University of Illinois at Chicago that a cell surface molecule (a receptor) called Niemann-Pick C1-like 1 (NPC1L1), which is known to facilitate the uptake of cholesterol into the cell, may also be involved in trafficking the virus into the cell.

The research team headed by Susan Uprichard, assistant professor of Medicine, Microbiology and Immunology, conducted experiments to determine the role of NPC1L1 on viral uptake. Experiments involved blocking the receptor and reducing expression by using knock-out models. The results demonstrated that blockade or knock-out of NPC1L1 impaired liver cell infection with HCV.

To confirm these studies further, an inhibitor of NPC1L1 called ezetimibe, which is clinically used to lower cholesterol levels, was also tested. Results validate previous findings showing blockade of HCV uptake into the cells and preventing infection.

Current drugs used to treat hepatitis C are known to be toxic, and cannot be used by transplant patients, therefore ezetimibe may provide a solution as a new anti-hepatitis agent. Therapy with ezetimibe alone or in combination with current drugs may improve patient treatment by targeting the receptor NPC1L1 and preventing HCV entry into liver cells.

Reference:
Sainz et al, (2012) Identification of the Niemann-Pick C1-like 1 cholesterol absorption receptor as a new hepatitis C virus entry factor. Nature Medicine. Ahead of print.

The paper can be found at: http://www.nature.com/nm/journal/vaop/ncurrent/pdf/nm.2581.pdf

Transparent tissues offer a window into the brain

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By Kathryn Higgins

 

A revolutionary reagent has been developed that can literally turn biological tissues transparent. Researchers from the RIKEN Brain Science Institute in Japan have developed a reagent which allows 3D imaging of the neuronal network deep inside a mouse brain.

Imaging and labelling of cell populations deep within tissue has been a challenge for scientists for many years. Although advances have been made in cell imaging there are still many obstacles to overcome. Tissues often have to be sliced 1mm thick for viewing under a microscope to dissect networks since imaging within deep tissues leads to many problems due to the lack of transparency of the tissue. Several clearing solutions have been developed but these have disadvantages such as expense and quenching of fluorescently labelled proteins that are often used in cell research to visualise the structures.

A research team led by Atsushi Miyawaki, however, have recently developed a reagent, after a chance observation, which may revolutionise deep tissue imaging by obtaining 3D images that are valuable for improving our understanding of biological organisms and how they function.

The reagent, called ScaleA2, is a highly effective clearing reagent, greatly improving the transparency of tissues, and stabilising fluorescently labelled proteins. This allows imaging to be done at a much greater depth than currently possible, providing detailed 3D visualisation of neuronal networks within the brain than has ever been managed before.

Current research using ScaleA2 was done using dead embryo tissue for imaging neurones and blood vessels deep inside the mouse brain. Miyawaki and his research team, however, believe that the scope for using ScaleA2 in other tissues and organisms is not limited, and are currently trying to optimise the reagent for use in live tissue. This would open the door to experiments that have never before been possible.

 

Image shows two murine embryos. The left embryo was placed in PBS, whilst the embryo on the right was incubated for 2 weeks in ScaleA2 solution.

 

 

Reference:

Hama et al, (2011) Scale: a chemical approach for fluorescence imaging and reconstruction of transparent mouse brain. Nature Neuroscience. Ahead of print.

The paper can be found at:

http://www.nature.com/neuro/journal/vaop/ncurrent/pdf/nn.2928.pdf

A Sweet Way to Heal Wounds

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By Kathryn Higgins

 

We’ve all heard the term rubbing salt into the wounds, but using sugar instead may be a new treatment for wound healing and reducing pain.

Moses Murandu, a Senior Lecturer in Adult Nursing at the School of Health and Well Being at the University of Wolverhampton, Birmingham, has just been awarded a £25,000 grant to continue a study in the effect of sugar on wounds and cuts.

Originally raised in Zimbabwe, Moses grew up following traditional African remedies, one of which involved treating wounds with cane sugar. Trained as a senior nurse, Moses was surprised to find that this was not common practise when he came to the UK stating “when I was a child, my father used sugar or salt and I grew up without realising that something that works is not widely used”.

Leading a study at Selly Oak Hospital in Birmingham, involving 21 patients whose wounds had not responded to conventional treatment, Moses poured granulated sugar onto bed sores, leg ulcers or amputations before the wound was dressed. However, he did point out that the sugar used was not taken straight off the supermarket shelves, but was certified, sterile sugar direct from the manufacturer.

The study found that a solution of 25% sugar was effective in not only reducing pain associated with wounds, but also improved healing. The sugar solution works by drawing water out of the wound into the dressing. Bacteria need water to survive so when sugar is added bacteria are killed leading to healing of the wound and reducing pain.

An abstract of this work was submitted by Mr Murandu to the Fondation Le Lous, and was awarded the Fondation Le Lous Research Innovation Award and £25,000 to continue his research for a further two years.

This innovative practise would save the NHS millions of pounds a year, with treatment costing about £1.49 each time compared to hundreds of pounds to hire equipment to drain wounds.

 

For further details of the study see:

http://www.wlv.ac.uk/default.aspx?page=24330

http://wlv.ac.uk/default.aspx?page=21067

 

Blood Groups Could Become a Thing of the Past

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Written by Matt Farley

 

New research from McGill University in Canada could do away with the need to classify blood by ‘type’, following a new technique to prevent mismatched blood from being rejected after a transfusion.

Along with the well-known A, B and O blood groups, there are a further 26 different blood types which have to be matched carefully when carrying out a blood transfusion – a mismatch can lead to the donated blood being rejected by the body which can be fatal. The ideal situation is for a ‘universal’ blood type which would be compatible with any recipient blood type.

Rejection occurs when the antigens on the surface of the donor red blood cells are of a different type to those on the recipient’s cells – previous attempts at avoiding this have focused on either removing the surface antigens from the donated blood using enzymes, or producing the blood outside the body from stem cells. These techniques have shown some success, but are hindered by their expense and complexity. The latest method, presented by Dr. Maryam Tabrizian and colleagues, instead aims to cover up the antigens and hide them from the host immune system – known as ‘immunocamouflage’.

Red blood cells from a selection of volunteers were coated in a layer of polyelectrolytes – small repeating units which self-assemble on the cell surface. Previous attempts at coating cells in this way using yeast and E.coli had shown promise, but it remained to be seen whether the delicate red blood cells would be able to withstand the process.

After coating, the cells were exposed to their opposite antibody and observed for any agglutination, or clumping of cells, that occurred. The coated cells were shown to remain free after addition of the antibody, suggesting that the antibodies had failed to recognise and bind the cell surface antigens. This was in contrast to the uncoated cells, which clumped together in the manner normally seen when mismatched blood samples are mixed.

Perhaps most importantly, the red blood cells showed no significant reduction in their ability to take up oxygen, implying that they would still be able to carry out their function within the body. The cells were also seen to produce ATP, an energy carrier – a good sign that metabolism was also functioning as normal.

It remains to be seen whether the technique will be as effective when tested in a living organism, but the results obtained so far appear promising. If effective, future blood transfusions could become a lot easier, and a lot less dangerous.

The paper accompanying this article is available online:

http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/bm101200c

Red blood cells