Walking the Dog

A dog is more than man's best friend.  My wife set my this amazing article from the Huffington Post. A study out of Cambridge University is using olfactory stem cells ( i.e. smelling stem cells) and transplanting them into damage spinal cord nerves of accidentally paralyzed dogs.

The nose cells called olfactory ensheathing cells are able to fix damaged nose fibers. The researchers reported that many of the dogs treated with these cells are regaining walking function and control of visceral organs.  Check out the video below of one of the dogs rehabbing its hind legs to walk again.  

This accidental injury model treated months after injure provide promise for humans paralyzed.  I enjoy how scientist are able to take advantage of nature's physiology.  Now the question is, who skipping medical school and becoming a doggy physical therapist?

http://www.huffingtonpost.com/2012/11/21/dogs-paralyzed-by-spine-d_n_2160950.html

Less is More: Negative Calorie Foods

So we've all heard about negative calorie foods, right? If you make a quick google search, you'll find a list of fruits and vegetables that are considered "negative calorie" foods: apples, cranberries, grapefruit, lemon, mango, orange, pineapple, raspberries, strawberries, tangerines, asparagus, beets, broccoli, cabbage, carrots, cauliflower, celery, chile peppers, cucumber, dandelion, endive, garden cress, garlic, green beens, lettuce, onion, papaya, radishes, spinach, and turnips. The idea is that these types of foods have less calories than it takes to digest them; i.e. their thermic effect (the amount of energy expenditure above the resting metabolic rate and exercise) is greater than their caloric content. As we learned during our metabolism lecture in physiology, it is beneficial to eat small meals throughout the day because it takes quite a bit of energy to kick start our metabolism. So, it seems logical that if you eat a fruit or vegetable that contains zero or close to zero calories, this would expend more energy during digestion and result in negative calories.



I recently thought of writing a blog about this topic and started to do some research. As it turns out, there is almost no research out there discussing negative calorie foods. One article I came across discussed the "negative calorie illusion." People are under the impression that "negative" calorie foods cancel out other types of foods. In a study done by Chenev et al., participants rated a cheeseburger with celery as having less calories than a cheeseburger by itself. This study really highlights the flaws in the way our society thinks. If I eat a pound of celery, it doesn't mean that cancels out the quarter pound cheeseburger I also just ate.

Throughout a day, 5-10% our our energy expenditure accounts for digestion. As Dr. Hensrud of Mayo Clinic states, "it is theoretically possible to have a negative-calorie food, but there are no reputable scientific studies to prove that certain foods have this effect."So, it is likely that you could lose weight if you only ate negative calorie foods, but, as we learned in physiology, it is essential to couple a healthy diet (including carbohydrates, proteins, and fats) with healthy exercise in order to maintain a healthy weight and lifestyle. 


References: 
Forwood SE, Marteau TM. 2012. Are genetic association studies useful for the elusive negative calorie illusion. Replicating Chernev's calorie estimate findings. Appetite. 59(2):629.

http://caloriecount.about.com/forums/foods/list-negative-calorie-foods

http://www.mayoclinic.com/health/negative-calorie-foods/AN02040

Personality changes placebo effect?

No study of any analgesic drug or treatment is complete without accounting for the placebo effect. I think it’s kind of amazing, though, how little we understand about the mechanisms and potential practical applications of the placebo effect, given how often scientists utilize it in studies of other therapeutics.  Recent research has come out, however, that sheds a little more light on this neurolophysiological enigma.

                The subset of the placebo effect that provides analgesia through mu-opioid receptors has varied strength of effect on different people. This month researchers at the University of Michigan highlighted personalty traits that are positively or negatively correlated with the strength of the mu-opioid placebo response.  It turns out that personality effects appear to account for 25% of the variance in placebo analgesic responses.  Ego-Resiliency, altruism, and straightforwardness were all positively correlated with placebo analgesic response.  Anger and hostility, however, were negatively correlated with placebo effect.  Unsurprisingly,  opioid release in the bran was positively correlated with analgesic affect, and cortisol tended to lower during placebo administration.

           So, if you want to maximize your own placebo analgesic effect, have strong ego resilience, be altruistic, and straightforward, don't be hostile or angry, and try to relax to lower your cortisol.  And if you design a placebo-controlled trial analgesic trial, now you know that the personality traits of your subjects can effect the variability of your results. 

Cheap Cancer Prevention

New research is showing that Vitamin D can play a role in cancer prevention.  Vitamin D, which can be obtained from dietary sources and direct exposure to sunlight, has been shown to inhibit the function and production of protein cMYC.  The protein cMYC drives cell division and is found at elevated levels in a variety of cancers. 

Vitamin D insufficiency has been correlated with increased incidence of certain cancers.  This correlation has been found in colon cancer and some forms of leukemia.  Canadian researchers found that vitamin D can stimulate the production of a natural antagonist of cMYC, MXD1.  This antagonist shuts down the function of cMYC. 

This group of Canadian researchers found that applying vitamin D to the skin of mice caused a drop in cMYC levels.  They also found that mice lacking the vitamin D receptor had increased levels of cMYC.  The researchers believe this is evidence that vitamin D may be able to keep cancer cell proliferation in check.  This shows that is essential to maintain adequate levels of vitamin c.  

http://www.gtmb.org/pages/Vol8b/HTML/35.%20Supino-Scovassi,%20385-3%20copy.htm

 

The figure depicts the role c-MYC can play in cell cycle proliferation and possible cancer progression.  If vitamin D can shut down c-MYC, then it can help keep cancer cell proliferation in check.

However, don't go rushing out there taking large doses of vitamin D in an effort to prevent cancers.  Vitamin D toxicity or hypervitaminosis D can have serious side effects.  First, too much vitamin D causes calcium build up in your blood.  This calcium build up can cause nausea and vomiting, as well as kidney problems. While, vitamin D toxicity is rare, it is still possible. 

So the key, as it is with most things, is moderation.   By getting the daily recommended doses of vitamin D, you are also helping to prevent certain types of cancers.

Vitamin d mechanism of action discovered by mcgill university. (2012, November 29). Retrieved from http://www.pcf.org/site/c.leJRIROrEpH/b.8467737/k.C035

/Vitamin_D_Mechanism_of_Action_Discovered_by_McGill_University.htm

Zeratsky, K. (2012, March 20). What is vitamin d toxicity, and should i worry about it since i take supplements?. Retrieved from http://www.mayoclinic.com/health/vitamin-d-toxicity/AN02008

Prescription Drugs and Dry Mouth

This blog is on a subject that has touched my family.  Both of my grandparents were dentists and I have never met anyone with better oral hygiene than my father.  So it was a shock for me to learn that my father has had 6 permanent teeth pulled in the last few years and now needs implants.  What is the sudden cause in the decline of his oral health?  It took changing dentists and meeting a knowledgeable hygienist who worked in a clinic with me to figure out that the root of the problem was dry mouth due to his prescription medications.

Saliva is essential for tasting and properly digesting food. It also helps prevent erosion of your teeth.  Several prescription drugs are known to cause dry mouth, such as anticholinergic, sympathomimetic, or diuretics.  Chemotherapy and radiation are also common causes.  Signs of dry mouth include difficulty swallowing, speaking, or with controlling dentures.  If left untreated, complications can include increased incidence of dental caries, halitosis (bad breath), candidosis, or ascending sialadentitis (pain and swelling of salivary glands).

If a patient is suffering from dry mouth there are a few recommendations you can make.  As a physician, you could try to alter the medications being prescribed.  Additionally, recommend the patient drinks lots of water and tries to keep their mouth as hydrated as possible.  Artificial saliva products are currently available. Tell them to AVOID alcohol-containing mouthwashes. (This was the major mistake my father was making.)  Of course, patients should also continue to improve upon their normal oral hygiene- brush and floss regularly, avoid sugary foods, use fluoride toothpaste, don’t wear dentures at night, etc.

Losing one’s teeth is a terrible thing, especially for patients who have taken excellent care of them their whole lives.  Dentures are no picnic and dental implants are extremely expensive (the cost of replacing a single tooth ranges from $1000-$5000).  As future physicians, PA’s and dentists, it is important that we all understand this connection and learn to recognize the signs and treatments.

For further reading check out this paper: http://www.nature.com/bdj/journal/v199/n7/full/4812740a.html

It's all About the Extra O

Good news!  This weekend I found out that my parents no longer purchase 
and consume food-grade hydrogen peroxide (H₂O₂)!  However, based on some research I've done, there are still those who believe that ingesting hydrogen peroxide has many health benefits. Although it is easy to scoff at and immediately disregard the use of hydrogen peroxide as a dietary supplement, I think that the fact that there are people doing this is reason enough to learn more about why they believe it is a good idea to consume a product that is also commonly used as a sterilizing cleaning product or bleach.  We all plan on future professions dedicated to helping people maintain their heath and, therefore, should be open to new and alternative treatments.  So here's what I learned:

Background:    Hydrogen peroxide is a ubiquitous molecule found throughout the human body and in the environment including exhaled air, human urine, as well as a number of food products such as green and black tea, and especially instant coffee.  It is considered a highly reactive oxidative species (ROS) due to its tremendous oxidative capacity.  H₂O₂ is a natural by-product of aerobic metabolism and, as such, mitochondria are responsible for a substantial portion of H₂O₂ production.  To prevent the accumulation of H₂O₂, organisms have enzymes such as superoxide dismutatse (SOD), catalase and  peroxidase which collaboratively catalyze the degradation of 2 H₂O₂ → 2 H₂O + O₂.  Concentrations of H₂O₂ are physiologically regulated and maintained through excretion and catabolic processes.  Interestingly, I also found information on WebMD about getting shots of SOD for pain relief, to increase tolerance for radiation therapy, to decrease damage to cardiac tissues following heart attacks, and for decreasing wrinkles.    

Danger of H₂O₂:  Exposure to UV-radiation or interaction with metals such as iron (commonly found in molecular components of red blood cells such as hemoglobin) can cause H₂O₂ to be easily converted to a hydroxy-free-radical (OH-).  Free-radicals are highly unstable molecules that can disrupt the chemical composition of other cellular components, thus compromising the cell's molecular integrity and potentially leading to cell death.

Why Believers Want to Drink H₂O₂:

• H₂O₂  is produced naturally in the body.
• H₂O₂  is "safe" (has been in use since 1920), readily available, and inexpensive ("dirt-cheap" in fact)
• "Good" bacteria use aerobic metabolism and greatly benefit from the increased oxygen environment created from H₂O₂  consumption.
• "Harmful" bacteria and cancer cells use anaerobic metabolism and cannot survive in the increased oxygen environment created from H₂O₂  consumption.

Potential Benefits:  Although, the mechanisms are not entirely understood, there is some evidence that beverages containing hydrogen peroxide can contribute to producing salivary secretions that contain molecules that are toxic to certain bacterial strains of the mouth and upper G.I. tract.  The hydrogen peroxide is able to diffuse directly into cells lining the oral cavity.  Metabolic hydrogen peroxide production in the urinary bladder is also believed to have beneficial antimicrobial qualities.  Hydrogen peroxide is also known to be involved in important physiological second messenger pathways.  

Conclusion:  From what I've read, it seems that the belief that consuming hydrogen peroxide could be beneficial to your health isn't completely random.  It has some ideas based on actual physiological processes however, they are taken out of context.  I am surely not going to pick up the habit, but I think that reading about alternative medicines from both sides is an important habit to development as a future healthcare provider.    

References: 

Halliwell, B. 1991.  Reactive oxidative species in living systems: source, biochemistry and role in human diseasse. Am J of Med. 91(3): S14-S22. 

Halliwell B, Clement MA, Long LH. 2000.  Hydrogen peroxide in the human body. FEBS Letters. 486(1): 10-13.

Williams DG, 2003.  The many benefits of hydrogen peroxide. Retrieved from: http://educate-yourself.org/cancer/benefitsofhydrogenperozide17jul03.shtml

65 (Celebratory) Roses

Did you ever raise money for cystic fibrosis research with Great Strides National Walk Event? Well, if you did or if you ever gave money to the Foundation, you probably helped create a promising new drug!
Even as a young kid I was not overly optimistic that the money I raised with the Great Strides Event would ever help the 3 older girls I knew with cystic fibrosis (CF). Cures and treatments seemed very far in the future, an improbable hope. However, the improbable has become more than probable!! 
A new drug, Kalydeco, was recently discovered for CF treatment (FDA approved Jan. 2012).  The Cystic Fibrosis Foundation website reveals, "It is the first drug available that targets the underlying cause of CF — a faulty gene and its protein product, CFTR." As we know from class, the CFTR receptor is able to localize to the cell membrane, but the mutant receptor causes a thick mucus to form as a result of nonfunctional chloride ion transport. This drug helps the mutant receptor function properly and improve lung function. They are unsure if this is a cure for CF individuals or a specific treatment. Unfortunately, this drug is only approved for individuals with a specific gene mutation: the G551D mutation.

Personally, I am getting very hopeful for CF treatments and possible cures. When I was younger I was devastated to hear that most cystic fibrosis patients did not live to see their 30th birthday. And now, I know five people with CF ages 26, 28, 30, and 31. And the reason I even found out about this new drug to blog about is that the 31 year old just delivered healthy baby TWINS recently! This would have been unheard of 30 years ago. The drug company Vertex is working on developing a similar drug to Kalydeco (VX-770) for the mutation that most CF patients have (and that the 31 year old new mother and her 28 year old sister both have.) This is very exciting for them and I hope that researchers are able to develop a similar drug quickly.


References:
I got the idea from a personal newsletter from our family friends. The title of the blog comes from the fact that many young kids refer to cystic fibrosis as "sixty-five roses" because they sound so similar and it is easier to say.
More drug information obtained from The Cystic Fibrosis Foundation website, http://www.cff.org/treatments/Therapies/Kalydeco/ 
Image from: ASBMB Today at http://www.asbmb.org/asbmbtoday/asbmbtoday_article.aspx?id=18382

A Little Peace of Mind...

Well...I was rather impressed by the yoga physiology group research project. So I looked into more ways meditation can affect our physiology and guess what? Meditation appears to produce long lasting changes in  the emotional response of the brain!

Crazy right...a little peace of mind can have LONG lasting affects on our emotional state after meditation. Researchers from Massachusetts and Boston University and several other research institutes found that differences in the emotional response of the brain depend on the specific type of meditation practiced.

There were two types of meditation tested in this particular study.

There are two different meditation routines and they affect the amygdala differently. As you all remember the the amygdala is the part of the brain that has been associated with memory and  emotion and it's the part of the brain that reacts to emotional content. 

What is amazing about this study is that it is the first time meditation has been shown to impact emotional processing OUTSIDE of a mediation state. 

According to Science Daily, the study showed through neuroimaging that:

 "meditation training appeared to decrease activation of the amygdala -- a structure at the base of the brain that is known to have a role in processing memory and emotion -- those changes were only observed while study participants were meditating."

Study participants who completed an 8-week meditation training course had reduced activity in the right amygdala (highlighted structure) in response to emotional images, even when not meditating. (Credit: Gaëlle Desbordes, PhD, Martinos Center for Biomedical Imaging, Mass. General Hospital) (Science Daily)

The researchers from BU hypothesized that their will be a decrease in the amygdala's response to emotional stimuli, seen through fMRI.

So what did the researchers do? 

healthy adult participants participated in an 8 week  meditation course in either 1) mindful attention meditation, which is the most commonly studied form that focuses on developing attention and awareness of breathing, thoughts and emotions;

 and the other group did the other type of mediation which is called  compassion meditation, a less-studied form that includes methods designed to develop loving kindness and compassion for oneself and for others. 

A third group the control group participated in an 8-week health education course.

The results? after the 8 week course the groups participated in a test, a sequence of emotionally charged either positively, negatively or neutral pictures and their brains were scanned fMRI.

The group that was trained int he mindful attention meditation showed a DECREASE  in right amygdala response to ALL images. This shows that meditation can regulate the emotional stability and the response to stress!

but that's not all!!

In the compassion meditation trained group the right amygdala also decreased during the neutral and positive images, however there tended to be an increase in right amygdala activity when viewing the negative images. 

There was no significant difference to the control group.

Gaëlle Desbordes, PhD, a research fellow at the Athinoula A. Martinos Center for Biomedical Imaging at MGH and at the BU Center for Computational Neuroscience and Neural Technology, corresponding author of the report states that,:

"We think these two forms of meditation cultivate different aspects of mind. Since compassion meditation is designed to enhance compassionate feelings, it makes sense that it could increase amygdala response to seeing people suffer. Increased amygdala activation was also correlated with decreased depression scores in the compassion meditation group, which suggests that having more compassion towards others may also be beneficial for oneself. Overall, these results are consistent with the overarching hypothesis that meditation may result in enduring, beneficial changes in brain function, especially in the area of emotional processing."

References:

 Meditation Appears to Produce Enduring Changes in Emotional Processing in the Brian. Science Daily. Nov. 12, 2012. retrieved from:http://www.sciencedaily.com/releases/2012/11/121112150339.htm

What is the Most Annoying Sound in the World?

"Hey, want to hear the most annoying sound in the world?"

What makes Lloyd Christmas's shriek so infuriatingly annoying?

Sound is one of our main cues for distress. Consider how in the jungle, when you suddenly hear the distress call of a monkey you may guess something dangerous is near. Now, we don't associate that unpleasant distress call with physical danger so much in a city but it may still illicit an unpleasant response. Aversive noises will create an emotional response.

In a recently published study, how this emotional response is triggered was investigated (Kumar 2012). They found that evoked emotional responses to aversive sounds (like the scream of a woman) were channeled through the amygdala. Variations in the acoustic characteristics of the sound change the connection patterns from auditory cortex to the amygdala, the perceived unpleasantness alters the relay of information from the amygdala back to the auditory cortex. Essentially, Kumar et al found that as the auditory cortex relays raw acoustic data to the amygdala, translation of that data (especially unpleasantness), and the elicited emotional response change how the auditory cortex interprets the acoustic data.

Now consider this, in Minneapolis, Orfield laboratories has a room that is so quiet it rates at -9.4 decibels, an anechoic chamber. The fiberglass walls are so absorbant it actually reduces noise to a perceived zero. Anecdotal stories of the room state that it is so quiet, that spending too long in the room makes it impossible to keep your balance. The absolute lack of noise causes people to seek auditory cues so desperately that they begin to hear the opening of their heart valves, muscles of their digestive tract, and expanding of their lungs. This utter lack of noise is said to be so distressing and unpleasant that the longest anyone has stayed in the room is 30 minutes.

So with the understanding that the amygdala requires acoustic signals to elicit an emotional response, I wonder what it is in an chamber void of sound waves that is signaling the amygdala to create feelings of distress. I would theorize that the auditory neurons, in the complete lack of stimuli, begin to depolarize and signal on their own. This random, uncoordinated signals are interpreted by the amygdala as acoustic information and produces feelings of distress. I would be very interested to see as study that looks at how the auditory cortex and amygdala behave without any form of sound input.



Thornill, T. (2012) "We all crave it, but can you stand the silence? The longest anyone can bear Earth's quietest place is 45 minutes." Daily Mail. Retrieved from: http://www.dailymail.co.uk/sciencetech/article-2124581/The-worlds-quietest-place-chamber-Orfield-Laboratories.html

Kumar, S., von Kriegstein, K., Friston, K., Griffiths, T.D. (2012). Features versus Feelings: Dissociable Representations of the Acoustic Features and Valence of Aversive Sounds. Journal of Neuroscience. 32(41) 14184-14192. doi: 10.1523/jneurosci.1759-12.2012

Coke Prevents Cancer

Coke Prevents Cancer

All you Coca-Cola fans calm down. The coke referred to here is cocaine, as in the drug often used in notorious dance club Studio 54 in the late 1970’s. This study looked at 163 patients diagnosed with testicular germ cell tumors (TGCT) and 292 patients without TGCT as a control (Lacson et al. 2012). TGCT will see 8590 new cases of testicular cancer in 2012 according to the American Cancer Society (American Cancer Society.: Cancer Facts and Figures 2012). The authors in this study wanted to see if this form of cancer had any ties to recreational drugs. As we know from genetics, when testing for environmental influences on a disease or condition (such as exposure to recreational drugs), you perform an odds ratio, which compares incidence to exposure remember this table (Franco 2012)?

Participants were interviewed about their drug use habits and then Odds Ratios were calculated for exposure to marijuana, cocaine, and amyl nitrate (Poppers). The results are pretty interesting. Remember, an odds ratio of 1 means there is no association between exposure and the condition. An odds ratio of less than 1 means the data shows a negative correlation, or that exposure decreases ones chance of getting the disease.

For those that ever used cocaine, the odds ratio for developing testicular cancer was 0.54 (with a 95% confidence interval). What? Yes, the data seemed to show that exposure to cocaine actually decreased ones chances of developing TGCT. Here is the kicker especially for Colorado; the odds ratio for TGCT in those who smoked marijuana was 1.94 (95% confidence interval). According to this data, marijuana users are 94% more likely to develop testicular cancer than non-users.

Now, before all you crazy graduate students that could develop testicular cancer go out and buy cocaine, note this; IT IS ILLEGAL, so don’t. Secondly, the authors suspect that the decreased odds of developing TGCT is because cocaine use may actually be killing the germ cells, thus, there are less cells that could potentially develop cancer. If you don’t have the germ cells, you are less likely to get germ cell cancer.

References:

 Lacson JA, Carroll JD, Tuazon E, Castelao EJ, Bernstein L, Cortessis VK (2012). Population-based case-control study of recreational drug use and testis cancer risk confirms an association between marijuana use and nonseminoma risk. Cancer, 118(21), 5374-5383. doi:10.1002/cncr.27554

  

American Cancer Society.: Cancer Facts and Figures 2012. Atlanta, Ga: American Cancer Society, 2012. http://www.cancer.org/acs/groups/content/@epidemiologysurveilance/documents/document/acspc-031941.pdf

Franco, MD. 2012.Genetics of Common Disorders with Complex Inheritance. Lecture, Fall 2012. Regis University Department of Biology

Glass Preference for Your Lager Good Sir or Madame?

Straight or curved glass for your lager good sir or madame?

Thiiiink about it…..

So what is your preference?

Well, according to Attwood et al. from the University of Bristol, the shape of your glass actually influences how quickly you drink your alcoholic beverage (Attwood et al. 2012). Right? Well, they have some pretty compelling evidence.

They monitored 159 social drinkers (no history of alcohol abuse) over two sessions drinking either a lager or a soft drink from a straight or curved glass that was either completely full (12 oz) or half full (6 oz). They were timed to see how long it took them to finish their drink, as well as complete a computerized task to identify when the glass was half full. Here are the 12 oz. glasses.

 

     

       The results are pretty crazy (to put it scientifically). The groups that drank the lager from the straight glass, drank 60% slower than those who drank out of the curved glass. There was no difference in drinking time for the soft drink between glasses and the slower drinking also was not observed when the subject only had a half glass of lager. 

         Interesting. I could imagine that this is because with a more narrow base, it would appear that you are closer to the end of your beer than you really are, thus, you might as well finish off what you have and move on to the next one (or move onto what ever else is on your agenda for the night). Maybe it is due to the amount left in the glass as you increase the angle… (I edited and rotated glasses to 70 degrees to show that the amount of beer left at that angle appears to be less for the curved glass)

This is probably one of those things that bar owners and beer makers have known forever and now someone just decided to do a study on it and share that info with the world.

References:

 Attwood AS, Scott-Samuel NE, Stothart G, Munafò MR (2012) Glass Shape Influences Consumption Rate for Alcoholic Beverages. PLoS ONE 7(8): e43007. doi:10.1371/journal.pone.0043007