BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Hair

Why Does our Hair Flow the Way it Does?

Do you ever wonder why your hair always naturally parts the same way? Our hair patterns can be described as our “hair whorl.” This denotes the direction in which the hair follicles orient themselves, as well as the number of times the hair rotates in a circular pattern. This can be either a single or double whorl. While this physical characteristic maybe be obvious to the naked eye, it is unclear why these patterns initially occur.

Boy with shiny short hair and whorls, rear view

In a recent study, the National Survey of Physical Traits cohort came together to understand whether or not our hair patterns could be determined by genetic characteristics. In China, Lead Investigator Sijia Wang determined that hair whorl can be a result of four genetic variances, also known as a polygenic inheritance. These variances occur at 7p21.3, 5q33.2, 7q33, and 14q32.13, which are specific locations on a DNA sequence. These variances affect hair patterns due to both cell polarity as well as cranial neural tube closure and extension.

This relates to AP Biology due to the effect of cell polarity on the hair whorl. In class we learned that non-polar (hydrophobic) molecules will move away from polar molecules. Hair cells are classified as epithelial cells, meaning they exist on the outer-most layer of our skin’s surface. They are polarized in sheet known as the planar cell polarity (PCP). The author’s logic makes sense in that a pattern will occur in the hairline if the polar molecules are moving away from those that are non-polar, or vice versa.

Blausen 0806 Skin RootHairPlexus

Additionally, because the whorls can be associated with neural tube closures and growths, it was believed that abnormally placed or shaped whorls can be related to a neurological deficit. However, Dr. Wang’s research did not confirm whether or not this was true.

Now it’s your turn — can you find your hair whorl?

 

Hair Saving Option with Chemotherapy

Scientists have been finding a way to prevent hair loss after the painful process of cancer treatment, Chemotherapy (Chemo). Hair loss is one of the biggest feared side-effects. A recent study showed that 75% of female patients who had breast cancer feared the side effect of losing hair. Hair loss scored the highest in a Swedish nurse’s study that investigated the quality of life in patients who had breast cancer. With the help of Sung-Jan Lin, a scientist at National Taiwan University, a protein was made that could withstand the distressing effects of Chemotherapy.

There are a few other options for people receiving this treatment. Some will try to put on scalp-cooling caps to freeze the chemo drugs from entering the hair follicles. However, this process is expensive and only works for 50% of the people. The treatment could end up being longer than expected, and can cause mild to severe headaches and discomfort.

Lin describes that part of the problem is that we have such a limited knowledge of how Chemotherapy damages hair follicles.

In short, his team looked at a protein called p53. This protein functions to limit tumor growth, but also helps suppress hair growth (hair cells divide rapidly like tumor cells)

Studying P53, Lin found out that the protein was blocking a hair-promoting protein WNT3A. This stimulated his team to ask the following question. Is injecting WNT3A directly into the scalp while administering Chemo prevent hair loss?

The team decided to experiment with mice with a chemotherapy agent, and soon enough the results matched their hypothesis. One group of mice were injected with WNT3A soaked beads. And sure enough, that group sustained their hair. While the other group that was not given WNT3A loss all their hair.

Lin and his team are now working to adapt his studies on human patients. As stated by Lin it would be unsafe to inject WNT3A in bead form. As a result, they are working to create the protein in a gel or cream solution.

With this new hair saving option, the cancer treatment will seem less fearful for some patients. This treatment could be a big help for the future. Scientists are working to expand their knowledge on how to effectively provide treatment without endangering our human traits.

So after hearing all this, what do you feel about this new idea? Will the “power of proteins” eliminate other side effects provided by Chemotherapy? If so, what kinds? Let me know in the comments below.

Photo link and photographer:

www.flickr.com/photos/calliope/6025359063

Liz West

Using Hair To Fix Nerves

Keratin

Scientists at Wake Forest University have discovered that the hair protein Keratin has been shown to speed up the regeneration of nerves in mice. When nerve function is lost, the best option is to use a nerve graft from another part of the body, however this is an issue because it creates another wound site for the patient, which may not be tolerable due to ones condition. In an attempt to create another means of regenerating nerves, Dr. Mark Van Dyke and his team of researchers began to test the Keratin protein (which is found in hair follicles).

To test Keratin for its regenerative properties, Dr. Van Dyke used human hair collected from a barber shop and removed the Keratin from it. They then purified it and created a gel out of it to fill nerve guidance conduits. In order to study how effective the protein was, they studied the Schwann cells. Schwann cells are important in this experiment because they create signals that begin nerve cell regeneration. The results of this experiment showed their hypothesis to be correct, the use of Keratin greatly increased the activity of the Schwann cells. After this proved to be true, the scientists used a keratin-filled tube to try to repair a large nerve gap in mice (about 4 millimeters). The animals treated with Keratin were compared to animals treated with a nerve graft, and animals treated with a placebo. after 6 weeks, the entire keratin group showed visible regeneration, versus the placebo group who had about 50% show signs of regeneration. In addition, the speed of repair for the keratin group was much faster the other groups. 

The results of all of his tests proved his hypothesis of the uses for keratin. “The results suggest that a conduit filler derived from hair keratins can promote an outcome comparable to a grafted nerve,” said Van Dyke.

Article: http://www.sciencedaily.com/releases/2008/01/080110102341.htm

 

Blondes Unite!

Despite the ‘dumb blonde’ jokes, and Danish or Dutch teases, I have enjoyed being blonde haired. As far as hair colors go, I think being blonde is perfectly suitable. However, there are certain preconceptions about hair color and race that people have. One being that people of certain ethnicities and races cannot have naturally blonde hair. This new study proves that idea wrong.

Photo Cred: Aust Defence Force

An article in the New York Times describes the experiments done on a group of people from the Solomon Islands. For some inexplicable (but not any more!) reason, many of the dark- skinned inhabitants have naturally blonde hair. But why?

Scientists did experiments on a giant chunk of the islanders, taking saliva samples from over a thousand people. Then they looked specifically at 43 blonde, and 42 dark haired islanders. What the discovered was that the blonde haired islanders had a specific gene, now called TYRP1, that changes the pigmentation of their hair.

What is perhaps most surprising is that Europeans have no trace of the gene in their genome. This, as Carlos Bustamante says: “For me it breaks down any kind of simple notions you might have about race,”

Hopefully these scientists will continue to learn more about hair and skin pigments and the genes that cause them. Do you like your hair color? Ever wonder why certain people seem to have one type of hair color instead of another? Just remember, it can all be explained by the genes.

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