Tryptophan is one of eight essential amino acids in the human body.  Essential amino acids are so called not because they are more important to life than the others, but because the body does not synthesize them, making it essential to include them in one’s diet in order to obtain them.

Like other amino acids, tryptophan works as a building block for proteins.  Tryptophan is found in every protein including fish, steak, cheese and eggs.  Tryptophan is required for the synthesis of some specific organic compounds including:

• Serotonin and melatonin (neurotransmitters)
• Niacin (vitamin B3), and
• kynurenines

Serotonin (5-hydroxytryptamine) affects mood, melatonin helps regulate sleep, and kynurenines may be useful in regulating the immune system.

A drug called tranilast, available in Japan as an allergy medication, is chemically similar to kynurenines and shows promise for the treatment of certain autoimmune diseases, including multiple sclerosis.

Turkey isn’t even unusually high in tryptophan. Many foods, such as beef or soybeans, boast higher concentrations (read more and see the table comparing Turkey Tryptophan to other foods after the break).

The calories in a big Thanksgiving meal can be staggering. According to USDA’s nutrient data laboratory, the 350 calories you’ll get from six ounces of light and dark turkey meat are just trickles in a caloric waterfall. Add to that one cup each of stuffing (200 calories), giblet gravy (300 calories), mashed potatoes (350 calories), candied sweet potatoes (400 calories), egg nog (400 calories) and cranberry sauce (400 calories); with two buttered rolls (300 calories) and two glasses of wine or apple cider (300 calories); and finished off with one slice of pumpkin pie with ice cream (450 calories) and one slice of pecan pie (600 calories); and you’re potentially doubling the USDA’s recommended daily caloric intake at one sitting.

 

Related Web Sites

Calorie Tracker from LIVESTRONG- this iPod Touch / iPhone application lets you look up or track your daily caloric, fat, carbohydrate and protein intake with the click of a button. You will have access to The Daily Plate at LIVESTRONG.COM, which offers a comprehensive nutrition database of more than 450,000 food and restaurant items. Most major competitors only have 7,000 items in their database.   WebMD Calorie Counter - Find out how many calories you will expend doing any of 30+ popular physical activities, from aerobics to gardening.   Medicine Net Thanksgiving Calorie Menus   Class Calorie Tracker- Our class data from Google Docs.  See the results here.

 

In honor of Thanksgiving, I thought a good dissection post is warranted.
Mary Carmichael over at Mental Floss has prepared a very detailed photo dissection of the lesser seen parts of the turkey.

Read the entire article here.

Have a Happy Thanksgiving!

White Meat

It’s the age old question, white meat or dark meat – what’s the difference?

All parts of the bird have their benefits and the constituents of their structure is related to their function flavor.

White meat is made up of muscles with fibers that are called fast-twitch fibers.  Fast-twitch muscles are used for quick bursts of activity, such as fleeing from danger. These muscles get energy from glycogen, which is also stored in the muscles. Glycogen is a polysaccharide of glucose, an animal starch.   Animal starch is stored primarily in the liver and broken down into glucose when needed by the white muscle.

Dark Meat

Dark meat is made up of muscles with fibers that are called slow-twitch. These muscles are used for extended periods of activity, such as standing or walking, and need a consistent energy source. Dark meat has more myoglobin, an amazing protein.  (This is the red liquid that you may see coming from meat at the butcher’s section of your local supermarket.)  Like it’s cousin hemoglobin, myoglobin delivers oxygen to the mitochondria.  Muscles that are used more frequently have higher amounts of myoglobin. More myoglobin gives the darker color of the meat.

This explains why the farmed turkeys (above left) have whiter meat than wild turkeys (above right). Farmed poultry do not fly, and is whiter than the chest muscles of the flying birds; also, why the game meat is darker (wild animals move much more than the domestic ones). Different levels of myoglobin between species also explains the difference in meat colors.
When dark meat is cooked it turns the myoglobins to metmyoglobins, which is brown/gray. Metmyoglobins are very high in iron (albeit there is not that much in dark meat in the first place).  Dark meats tend to contain more zinc, riboflavin, niacin, thiamin, vitamins B6 and B12, amino acids, iron than white meat. Poultry dark meat contain vitamins A, K, B6, B12, niacin, folate, pantothenic acid, minerals as selenium, phosphorus and zinc.

Even the fats in most of the dark meats have healthy parts. They contain Omega-3, and Omega-6 fatty acids, and other ‘healthy’ fats.

It is the saturated fat content which lowers the true quality of dark meat. To reduce the saturated fat content of chicken dark meat, simply remove the skin.

Related Web Sites

The Accidental Scientist: Science of Cooking – What gives meat its color? – A brief explanation of what gives meat its color. The Accidental Scientist: Science of Cooking: Comparative Muscle Chart – A visual description of the slow and fast twitch muscles found in humans and various animals. BBC Science and Nature: Muscles- Fast and Slow Twitch – A brief explanation of the two types of muscle fiber: fast and slow twitch. An interactive body game is also provided U.S. Census Bureau – Facts_for_Features, Thanksgiving 2004. – All sorts of facts about Thanksgiving, such as number of turkeys raised in the United States, can be found here. Turkey for the Holidays – Everything you wanted to know about turkey, such as nutrition, safety, facts, history and lore, can be found on this Web site from the University of Illinois Extension Service.

Sources:
http://www.diet-blog.com/archives/2007/10/08/dark_meat_vs_white_meat_whats_the_difference.php

http://www.drdonmd.com/health_articles.cfm

http://news.softpedia.com/news/9-Things-You-Did-Not-Know-About-Muscles-74768.shtml

 

 

Why does a turkey continue to cook after it’s out of the oven? How can you be sure to thoroughly cook the dark meat without drying out the white meat? Is stuffing really a good idea? How do you make the skin golden?

This webcast at exploratorium investigates why temperature is critical, and investigates different cooking methods: roasting,deep frying, barbecuing, and smoking.

Source: http://www.exploratorium.edu/cooking/webcasts/turkey_cast.html

by Maggy P

According to an article on ABCnews.com, people are finding new ways to tell their ex-partners that they have a STD– through e-mail. A new website called Inspot.org is now offering a service (e-mails, e-postcards) to notify a former partner that they may be infected with something. The sender can choose which STD they want to notify the receiver of, and if they want to include their name or stay anonymous. Since 2004, 30,000 people have used the site to send notifications to partners.

Although this does seem like an easy way to notify someone to get tested – which is ultimately the purpose of the e-card- I’m not sure if I would want to hear from a sexual partner this way. One of the things that psychologists talked about in the article was the damage that recieving an e-mail with that kind of information could do to a person. In fact, many people who commented on the story wrote that they would rather hear it from the person they were with face-to-face. Even though I think that would definitely be the best way to tell someone that they may be infected, I think that it’s definitely better to get an e-mail that get a surprise the next time you go to the doctor, or spread it to someone else unknowingly. One thing is definite, though – I wouldn’t want that e-card to end up in my spam box!

Not everyone who came in contact with the Black Plague bacteria, which ravaged medieval Europe, died. Geneticist Steven O’Brien is interested in  why some survived when so many others died. In a PBS special, O’Brien and filmaker Steve Crohn visit a small English town that was hit by the plague in 1665.  Using historical records, town archives and modern forensic techniques, O’Brien turns the town into a medical case study that reveals some startling information about the disease.  After proving that the scourge in the town really was plague and not some other disease, he discovers that the people who managed to survive were blessed with a genetic mutation that made them immune to the effects of the bacteria. Even more startling, that same genetic mutation has now been linked to some people immunity of another deadly disease — AIDS. This program tells the story of the survivors of the devastating plague and takes viewers on a journey of investigation into the world of a deadly pandemic. 
Source: http://www.pbs.org/wnet/secrets/previous_seasons/case_plague/interview.html

(courtesy of Mr. Wolsko)

French Isabelle Dinoire, 41, a few months after her surgery (l) and a year later (r)

The concept of organ transplantation is one that, at this point in medical science, is very well known.  Look at the back of any driver’s license.  Most of the time, when we think of organ transplantation, we think of internal organs:  heart, lung, liver, and kidney being taken from one person and given to another.   Yet, the transplantation of faces, as strange as this may sound, has moved from science fiction to science fact.  In 2005, the first facial transplant (a partial one) was performed on Isabel Dinoire of France.  She was mauled by her dog as she slept; her lips and entire the bottom of her face below her nose was torn away.  Part of a suicide victim’s face was used to restore Isabal’s ability to eat and speak normally.

At the end of March 2008, the first full facial transplant was performed in France…ironically, by a team led by a doctor who said he would not perform full face transplants.

Should this surgery be continued? Tell us what you think? Is this an area medicine should be exploring?a

 

 

Related Web Sites

March 2008 – The first Full facial transplant!  Full Facial Transplant Simulation A short clip showing the possible hybrid face that might occur as a result fo a full facial transplant.    World’s Second Facial Tansplant - This article and accompanying pictures detail the world’s second facial transplant, done in response to a disfiguring bear attack.   A well documented look at facial transplantation.Good pictures, and good descriptions of facial transplantation.   Another article on face transplantation - This article has some very dramatic pictures. The first picture, I think, is the most dramatic one in terms of improving a disfigured face.

 

by Melissa F

People infected by the HIV virus have a large amount of T cells in their body.  Researchers have possibly found a way to help patients with infectious diseases within the body.  When T cells interact with a virus, they “replicate and produce virus killing chemicals”.  The only problem is that these T cells eventually become exhausted and cannot fight the virus any longer.  Researchers dug further to find the reason for this.  They found that a protein, called TIM-3 is to blame.  TIM-3 cells were found on many HIV infected T cells and inhibit the T cells from doing their job.  Researchers are not yet sure of why or how this protein is present but they believe that blocking TIM-3 proteins will most likely help T cells fight the infection.  This study could also help patients with other infections within the body.

I found this article interesting because I know of some people infected with HIV and hope that one day there will be a cure for the disease.  I think it is great that studies are still being conducted even though the disease is not a main topic (such as Cancer).  I know that HIV is still a problem in the United States but not like it is in foreign, third world countries such as Tanzania.  Obviously education is also a key to under-educated populations to understand what the disease is and how it is spread.  Even if we do find a cure, it will take a long time for the entire world to be cured of it.

Source: Science Daily.com

http://www.sciencedaily.com/releases/2008/11/081110112058.htm

A Swiss study, put male underarm secretions thought to contain pheromones under women’s noses.   Forty-nine male university students were asked to wear cotton T-shirts for two days without using any soap, deodorants, and so on. Afterward, forty-nine female university students were asked to smell six shirts each and rate them in terms of smells that may be pleasurable in a partner.

Researchers were looking to see if the women sniffed out immunity genes, called the major histocompatibility complex (MHC), which are very closely linked to pheromone-generating genes.  The different genes in the MHC are what give us immunity to disease.  They are also what could cause us to reject an orgna transplant if there is no MHC compatibiloty between the donor and the recipient.

Each woman whiffed three T-shirts from men who had dissimlar MHCs from her own and three that were similar.  The more preference women had for a T-shirt, the more dissimilar the men’s MHCs were from their own.  In other words, the women were able to detect the MHC and preferred men with different immunity genes from themselves.

It’s speculated that one reason women may naturally select men with dissimilar immunity genes is that it acts as an insurance in offspring MHC diversity,  thus providing increased immunity to parasites.