Category Archives: Medicine

Learning from Mistakes

Posted on March 14, 2012 by | 2 comments
Image from learnforeverblog.blogspot.com

Image from learnforeverblog.blogspot.com

“We learn more from our failures than from our successes.” You probably have heard of that phrase more than once in your life. And you may have even thought of the phrase as untrue. We make little mistakes repeatedly all the time: forgetting to put soap into the dishwasher, not thinking before we speak, eating too many sweets. We don’t always learn from those mistakes. Rather, we often repeat them.

But mistakes can separated into many categories: From stupid mistakes, like stubbing your toe; to simple mistakes, like missing the bus. There are also more complicated mistakes that may result from sequences of mistakes building upon each other, leaving you with relationships that fail, a negative outcome to a significant event, or a poor grade in school.

Researchers from the University of Exeter have found that we do learn more from our failures than from our successes, especially when it comes to more involved and complex mistakes.

Complex mistakes often result from errors in predictive judgement. In other

Image from science.ca

words, every decision we make is predictive of the final outcome. Good judgement results in success, while poor judgement may leave us with failure. The study done at the University of Exeter used electrophysiological measurements (electrodes) to monitor the brain activity of volunteers when a prediction was made on a computerized task, and after new information was introduced, which make their predictions incorrect. The volunteers needed to learn from the incorrect prediction in order to stop repeating the error. A strong brain signal was measured in the lower temporal region of the brain every time the volunteer was presented with visual that had previously cause them to make an error, and before there was time to consciously make a better decision. This early “warning signal” immediately alerts us of our previous mistake and prevents us from repeating it.

Researchers from Michigan State University have also found that the brain reacts differently when one thinks that they can learn from a mistake verses someone who doesn’t think that they can learn from a mistake. When one believes that they can learn from an accepted mistake, the brain is tuned to pick up on mistakes faster.

 

 

References:

http://research.msu.edu/stories/learning-our-mistakes-hardwired

University of Exeter. “Why We Learn From Our Mistakes.” ScienceDaily, 2 Jul. 2007. Web. 14 Mar. 2012.

Wills, A.J.,Lavric, A, Croft, G. and Hodgson, T.L (2007). Predictive learning, prediction errors and attention: Evidence from event-related potentials and eye-tracking. Journal of Cognitive Neuroscience. 19, 843-854.

 

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Posted in Biological Sciences, Medicine, Science in the News

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Is Vitamin C better than other cancer treatments?

Posted on March 5, 2012 by | 1 comment

There are many existing cancer treatments such as removing tumors by surgery, chemotherapy, and radiation therapy. However, all the treatments mentioned above have high risks in damaging patients’ health in the process of  killing or removing the tumors.

There have been ongoing discussions about the intravenous treatment of vitamin C as an alternative  cancer treatment by reducing tumours for cancer patients. One of the first researches on the effect of vitamin C on cancer patients was done by Nobel laureate Linus Pauling about 40 years ago. Even though his experiment was later criticized for being faulty and biased, the idea of  vitamin C’s benefits for cancer patients was further investigated.

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Vitamin C is one of the antioxidants that can prevent cancer. Antioxidants inhibit oxidation in human body. Substances such as oxygen which can oxidize into free radical molecule and damage cells’ DNA or cause cell death. Vitamin C is also known to improve our immune system, and prevent illnesses such as common colds.

However, this same vitamin C, also known as ascorbic acid, is shown to reduce the tumour size in cancer patients. This is when the ascorbic acid is absorbed intravenously(IV) and in high dosage.

One of the many research papers on the effects of ascorbic acids shows decreased growth rate of mesothelioma cells, which is cancerous tumor cells. Since the growth and the spread of tumors with defects in its DNA are the crucial risk of cancer, the results of decrease in growth of tumor cells are significant improvement for cancer treatments. Another research article states that vitamin C is toxic to certain cancer cells, but not to normal cells.

The ascorbic acid is put into our body in the sodium ascorbate form to decrease the pH difference of the vitamin C and human blood. Therefore, if we consume too much ascorbic acid orally, it could cause acidic stomach.

Despite all the benefits of vitamin C, there are some critiques about vitamin C treatments that it only kills certain types of cancer cells, and  an excessive amount of vitamin C can affect absorption of Copper  and Selenium.

However, even with these minor concerns, trying the intravenous treatments of ascorbic acid for reducing tumor growth could be considered beneficial for cancer patients. Also, further researches and developments on the ascorbic acid treatment for cancer patients could improve the use of treatments for the future.

 

References

http://www.jamiesonvitamins.com/node/74

http://pdn.sciencedirect.com/science?_ob=MiamiImageURL&_cid=272308&_user=1022551&_pii=S0006291X10002123&_check=y&_origin=article&_zone=toolbar&_coverDate=02-Apr-2010&view=c&originContentFamily=serial&wchp=dGLzVlk-zSkWA&md5=232d451371f7652e84e112edc22aff87/1-s2.0-S0006291X10002123-main.pdf

http://www.sciencedaily.com/releases/2007/09/070910132848.htm

http://www.quackwatch.org/01QuackeryRelatedTopics/Cancer/c.html

http://content.ebscohost.com/pdf17_20/pdf/2006/04J/28Mar06/20225740.pdf?T=P&P=AN&K=16567755&S=R&D=mnh&EbscoContent=dGJyMMvl7ESeprM4y9fwOLCmr0qeqK9Ssqi4SLaWxWXS&ContentCustomer=dGJyMPGrtE%2Bwp7dMuePfgeyx44Dt6fIA

http://www.orthomed.com/civprep.htm

 

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Posted in Biological Sciences, Issues in Science, Medicine

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The Neurological Basis of Williams Syndrome

Posted on February 28, 2012 by | 1 comment

Williams Syndrome is a rare non-fatal congenital condition in which affected children are mildly to moderately retarded and score below average on IQ tests. They usually read and write poorly and struggle with simple arithmetic,  yet they display unique abilities in other areas of intelligence, especially emotional intelligence involving socializing and empathy. The disorder affects males and female from all racial backgrounds at an equal probability.

The disorder is caused by deletion of a tiny piece from one of the two copies of chromosome 7 present in every cell of the body. Twenty-give or more genes are deleted and loss of one in particular (ELN) which codes for elastin, a connective protein gives rise to cardiovascular problems.

Such cardiovascular problems include heart murmurs and narrowing of major blood vessels, and supravalvular aortic stenosis, a constriction of the aorta. Babies may have difficulty feeding or suffer from stomach pains and hernias.  As they develop, they show delayed physical and mental development with unsteady voices. They walk awkwardly for the rest of their lives and fine motor control is impaired. They are also highly sensitive to noise, grow to a  shorter height than average and seem to have gray hair and wrinkles earlier. Lifespan for Williams patients is shorter than average due to the complications from these medical problems, but not from the Syndrome itself.

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Williams patients usually have vocabularies larger than expected for their mental age and tend to be more expressive than normal children. However, they typically do poorly on tasks involving visual processing such as coloring and copying drawings. The brain anatomy of Williams syndrome patients is normal, but the total volume is slightly reduced. The areas that seem to be unaffected include the frontal lobes and a part of the cerebellum called the neocerebellum, as well as parts of the temporal lobes known as the limbic area, and the primary auditory area.

Study of this syndrome has shown that low IQ scores can indeed cover the existence of other skills and capacities. And it thus serves as an example that other so-called mentally disabled individuals could have lots of potential waiting to be discovered if only researchers and society take the time to look for and nuture them.

References:

Hemizygosity at the Elastin Locus in a Developmental Disorder: Williams Syndrome. A.K. Ewart et al. in Nature Genetics, Vol. 5, No. 1, pages 11-16; September 1993.

http://children.webmd.com/williams-syndrome-11011

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Posted in Biological Sciences, Medicine, Science Communication

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Treat your cavity before you feel the pain

Posted on February 6, 2012 by | 2 comments

Toothaches caused by cavities can be painful, and the treatment of drilling and filling can be even more painful. As one who fears tooth-aches, using the frequency-domain photothermal radiometry (PTR)  and modulated luminescence technology (LUM) in treating cavities before it causes pain is eye-catching. Recently, Health Canada  approved  a version of this technology to be used in dental offices.

When  bacteria in our mouth digest carbohydrates from the foods consumed, they produce acids that demineralize  the tooth enamal which causes lesions known as caries, and lead to cavities. YouTube Preview ImageFor previous and many current treatments of cavities, dentists drill the cavities out and fill the hole with Amalgam, Gold, special plastic material, or other filling material. X-rays are often used to detect progressed cavities for drilling and filling treatment

Dr. Andreas Mendelis and his research team found a way to distinguish the area affected by the lesions before it causes the pain. Lesions have different characteristics compared to healthy teeth enamel in optical and thermal properties. The research team scanned teeth with low-power diode laser energy, and the distinctive luminescence and emitted heat of lesions were detected by an infrared camera. Measuring the reflected light and heat absorbed by the tooth can detect lesions in up to 5mm in depth of the tooth. From then on, reminerlizing solutions, such as flouride is used to restore the lost enamel as stated in Mendelis’ research.

When the laser is shone onto the tooth, the absorbed fraction of the photon after  migrating and scattering creates oscillatory temperature field. The oscillatory temperature field is then detected by the photothermal radiometry. Then, the different temperature of lesions and healthy enamel are observed.  The modulated luminescence(LUM) is added in detecting  lesions. There variation in the lifetime of decaying and healthy part of the tooth, which helps in detecting the lesions.

Laser light being shown onto the tooth. Image from thecanarysystem.com

The difference of this new photothermal radiometry and traditional X-ray is that photothermal radiometry detects lesions in early stages where remineralizing solution can be used, instead of the drilling and filling. Many more benefits come from PTR and LUM treatments, including more accurate results and less painful procedure.

Reference:

http://www.magazine.utoronto.ca/leading-edge/andrea-mandeli-photo-thermal-imaging-radar-detecting-tooth-decay-quantum-dental-technology/

http://scitation.aip.org.ezproxy.library.ubc.ca/getpdf/servlet/GetPDFServlet?filetype=pdf&id=JBOPFO000013000003034025000001&idtype=cvips&doi=10.1117/1.2942374&prog=normal

http://scitation.aip.org.ezproxy.library.ubc.ca/getpdf/servlet/GetPDFServlet?filetype=pdf&id=PSISDG00685600000168560B000001&idtype=cvips&doi=10.1117/12.763807&prog=normal

http://thecanarysystem.com/pdfs/Publications/2011_March_5_drbicupsid_on_IADR_Meeting.pdf

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Posted in Biological Sciences, Medicine

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Immune Cells from Healthy Donors May Help Fight Cancer Cells in Patients

Posted on February 6, 2012 by | Leave a comment

 

Image from University of Oslo : Professor Johanna Olweus and her research team

Today, it is estimated that 2 out of 5 Canadians develop some type of cancer during their lifetime. Cancer rates are increasing around the world and is becoming a major concern. Professor Johanna Olweus and her research team at the University of Oslo have recently come up with a new method to treat certain types of cancer. The treatment involves using immune cells from donors to attack cancers cells in the patient. They claim that this approach has potential to eradicate cancer forever.

 

Image from Wikipedia by Fvasconcellos : General structure of an antibody

There is no known “cure” for cancer at present, but it is managed in several different ways. Immunotherapy treatments have been quite successful for several cases. Immunotherapy for cancer usually involves introducing antibodies or performing bone marrow transplants. Antibodies are proteins produced by white blood cells that recognize specific pathogenic cells, molecules, or the infected host cells. By tagging the infected cells, antibodies allow the body’s immune system to attack only those cells and prevent further damage. However, antibody-mediated treatments are not always effective because due to its high specificity, antibody targeted against one type of cancer cell is not effective for others.

 

Image from Flickr by Microbe World : T cell (center)

Bone marrow transplants are performed for patients with leukemia or lymphatic cancer. It involves transferring the bone marrow, which produces new blood cells, and T cells from the donor. T cells are important immune cells that, like antibodies, target specific cells and perform immune responses. Host T cells do not recognize cancer cells as foreign or harmful, however, since cancer cells are in fact host’s own cells that grow and replicate uncontrollably. The added T cells recognize cancer cells both as foreign and harmful, and act quickly to eliminate them. The treatment is effective but also very dangerous at the same time; new T cells can attack normal, uninfected cells of other intestines, causing serious damage or even death.

 

Professor Olweus attempts to combine the effectiveness of the transplant treatment with the accuracy of the antibody treatment. She was able to select donated T cells that targeted cells found only in specific organs. The injected T cells killed both healthy and infected target cells, preventing the tumor from spreading any further. This could be a powerful tool for people with types of cancer such as breast or liver cancer, which affect organs that people can live without, or that can be replaced with transplants. Another advantage is that T cells are more effective in detecting abnormalities in a cell. Antibodies only scan the cell surface but T cells can analyze both inside and outside of cells, providing a higher level of accuracy.

 

The study has promising aspects, but obviously has limitations. The method doesn’t seem to work for cancers such as lung cancer where we can’t manage to live without the organ. Most people would still prefer to live with their organs intact, and it would be ideal if only the infected cells were targeted. With further research, hopefully we will be able to overcome such limitations.

 

References :

http://www.cancer.ca/quebec/about%20cancer/cancer%20statistics/cancer%20statistics%20in%20quebec.aspx

http://www.wsws.org/articles/2003/apr2003/canc-a26.shtml

http://www.sciencedaily.com/releases/2012/02/120203091815.htm

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No more wires! Vital Signs monitored by Electronic Tattoos

Posted on February 6, 2012 by | 4 comments

The new patch that will revolutionise a patient's medical monitoring system. Image from John Rogers (University of Illinois)

The future looks bright for electronic monitoring, as temporary tattoos could revolutionise how the medical system keeps tabs on it’s patients.  The old, bulky devices that have been seen in hospitals, may now be replaced by the new, state-of-the-art temporary tattoo vital sign monitors.  Imagine the option of being monitored medically without the sticky gels and electrodes hooking you up to a machine; it sounds ideal to me! 

Electrodes; Image from Flickr: quinn.anya

Composition

John Rogers of the University of Illinois, termed this patch and it’s functions as “Epidermal Electronics.”    It takes the chemical components of larger electrodes (such as diodes, transmitters etc) that are found in the medical monitors of today, and builds them into wires only nanometers in size.  Rubber is then placed underneath this framework of wires which are placed on a water-soluble patch that resembles the structure of a rub-on tattoo and is only 40 micrometers in size (see Picture #1)!   The patch is flexible enough to expand and contract with the movement of the skin.  Application of the device is very similar to that of a rub-on tattoo, where it can be applied with a wet cloth and then a plastic shield is removed to reveal the vital-sign monitor.

 How it works
 
 How does this electronic device stick onto the skin of a person without falling off?  The chemistry of van der waals forces come into play, where the device touches the skin and they create an electric attraction between molecules.  This allows them to bend and form together with the two forces interacting to prevent the patch from falling off. 
If a patient is concerned with how the device appears, there is always the option of concealing it with a temporary tattoo that has a different design.  The video below from Youtube and NewScientist explains the monitor using a rub-on tattoo to hide the actual device: 

 YouTube Preview Image

Rogers and his team of researchers were able to determine that the chip was affective using a study of volunteers.  These people were able to place the minature monitor on their necks and any electrical changes from muscle movement throughout their body was sent through a computer that determined the participant’s vitals.

 What does this mean?

This device seems to be very beneficial for patients that need to be monitored for a few days in a clinical environment, however nowadays as our world is becoming more electronic we may be able to do this ourselves one day. The more options we will have for microscopic wireless devices in our everyday lives will rise. For example, iphones are currently creating applications to determine things like blood pressure, which is just a step in the direction of having vital signs monitored by our own cellphones!  The result could then be forwarded to a doctor electronically: no hassle, no fuss!

References:

NewScientist:
http://www.newscientist.com/article/dn20787-electronic-tattoos-to-monitor-vital-signs.html

Article in The New York Times:
http://www.nytimes.com/2011/09/04/technology/wireless-medical-monitoring-might-untether-patients.html

 John Rogers of the University of Illinois:
http://chemistry.illinois.edu/faculty/John_Rogers.html

 

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Posted in Biological Sciences, Issues in Science, Medicine, Science in the News, Uncategorized

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The Neuropsychology Behind Rubbing that Stubbed Elbow

Posted on February 3, 2012 by | Leave a comment

Everyone has experienced it at least once, where a slip or misjudgement quickly led to a painful stubbing of your elbow or toe. Usually when this happens though, there’s a near reflexive behavior we exhibit: we begin to rub the injured area instinctively-thinking this will help the pain! Could there be an actual biological purpose behind this? Well according to a 20th century theory from Neuroscientists Ronald Melzack and David Wall, pain and touch may actually compete for perception from your elbow to the brain. This  concept is known as the Gate Control Theory of Pain, and is still a dominant theory of the interactions of touch and pain today.

So how could rubbing your whacked elbow dull out the pain? The theory is based on the pathways of two receptors: mechanoreceptors, which transmit touch as changes in pressure, vibration and movement on the skin; and nociceptors, which transmit pain from damage or potential damage to the skin. Both receptors send nerve signals through different pathways to a region of the spinal cord known as the Substantia Gelatinosa (SG), which is full of transmission cells that send pain and touch signals to the brain.

Though both pain and touch nerve fibres leave the skin and arrive at the SG, the speeds at which they get there are drastically-different. Touch sensations reach the spinal cord through A-beta fibres, which are very fast due to their wide, myelinated axons. The sharp pain of nociception travels through slightly-slower myelinated A-delta fibres, and that dull, throbbing pain we feel occurs from a separate, slower C fibre.

The three theoretical states of the Pain Control gate. Via HowStuffWorks.com (References)

What Melzack and Wall’s Gate Control Theory proposes is that if touch and pain meet together in the SG, then touch will have an inhibitory effect on the transmission of the sensation of pain (left). So relating this back to that painfully-stubbed elbow, at first you’d may remember feeling a sharp A-delta pain followed by a dull C-fibre one (S). However, if you rub at the injured area afterwards, then the fast A-beta touch fibres (L) may cause an overwhelming inhibitory effect on the pain transmission through the SG, exchanging the perception as touch instead! So perhaps rubbing that elbow really does make a difference in the end. Worth noting though is there is a reason this theory has received scrutiny; it is a rather simple theory to explain an entire range of somatosensation we experience, and recent physiological work has shown that the transmission of pain and touch is more complicated than what the Pain Control Gate theory suggests. Regardless, it may be the only somatosensory theory that can explain the many observed interactions between pain and touch, including why rubbing the skin of that stubbed elbow seems to mask the pain so well.

References

Wolfe, J. M., Kluender, K. R., Levi, D. M., Bartoshuk, L. M., et al. (2009). Sensation and Perception. (2nd ed.). Sinauer Associates, Inc.

http://www.drgordongadsby.talktalk.net/page13.htm

http://science.howstuffworks.com/environmental/life/human-biology/pain4.htm

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