Cancer: Stem Cells In Reaction to Heat

In an attempt to treat cancer, doctors usually use radiation to "zap" tumors. However, this procedure may not always go according to plan. The tumor may originally shrink, but if cells inside of the tumor survive the radiation, they can come back even stronger than before. Researchers have found one solution to this. By heating the tumor prior to the operation the resistance by the stem cells can be drastically lowered. This technique is called hyperthermia. It has only been used to fight breast cancer, but it is possible that it could be effective on other types of cancer as well. Researchers based this technique off one from 5,000 years ago. An ancient Egyptian papyrus shows heat being used to fight breast cancer. However, heating alone with out other techniques has shown to be ineffective. A similar technique was attempted back in the 1970's and 80's, but it proved to be ineffective. Today's success is, in part, due to the technological advancements that have been made. With today's technology we are able to heat the tumors directly and more precisely. Scientists believe that the heat, when applied to the tumor, disrupts the stem cells, thus causing it to become more sensitive to radiation. When researchers used radiation on mice, that had human breast tumors transplanted into them, they found that the amount of cancer stem cells in the tumor had greatly increased. However, after, when they used hyperthermia on the tumor, heating it to approximately 108 degrees F, the amount of cancer stem cells ceased to increase and in most cases began to decrease. It is believed that cancer stem cells lost their ability to repair damage caused by the radiation. Researchers hope to set up clinical trials in the Texas Medical Center soon, although similar techniques are being used elsewhere.

Sources:

http://www.hhmi.org/news/atkinson20101102.html

http://drugdiscoveryopinion.com/tag/cancer-stem-cells/

Create your own video slideshow at animoto.com.

Do Fish Feel Pain?

Do fish feel pain? This topic has been debated by scholars for decades. Some people believe that fish are incapable of experiencing pain, while others believe that they are indeed capable. Some people believe they do not have very complex nervous systems and therefore do not feel pain to the extent that we do or perhaps even not at all. However, this idea is not completely accurate.  There has been some research that indicates that fish have the same kinds of specialized nerve fibers that mammals and birds use to identify tissue damage and thus pain. From all the information I have gathered I personally believe that fish can feel pain. Experiments show that fish respond when they are hurt, and pain relievers cause there behavior to change drastically. I would like to state that I am not against fishing what so ever, I realize that fish are an essential part to modern day civilization. What I do think, however, is that fish should be treated in a more humane manner.  For instance there have been fortifications put in place in order to protect birds and mammals, that do not include fish.  I believe this is largely due to the identity fish have. They are viewed differently than animals like cows, and chickens. In my opinion this doesn't make any sense, they are no less an animal and therefore deserve to be treated accordingly.






Sources:

1) http://www.biologynews.net/archives/2010/11/17/researcher_explores_whether_fish_feel_pain.html<script 
2) http://www.daviddarling.info/encyclopedia/V/vertebrate_nervous_system.html
3) http://www.bishops.k12.nf.ca/wells/vfish/projects/nervous/SENSES.html

Osmoregulation in Freshwater Fish

Freshwater fish absorb water passively and release it actively. Meaning they acquire water using no energy, but in order to release it they need to use energy. This process is due to fish's kidneys.  Their kidneys gain water osmotically. Meaning they absorb water by osmosis, which as I touched on before, is a type of passive transport. Fish's kidneys also produce dilute urine in order to get rid of waste matter.  Fish are in a constant state of osmosis, because they are hypertonic. This is not good because water continues to diffuse into fish, creating a very high concentration of water in their system. Fish deal with this problem with their kidneys. Fish's kidneys have a big surface area which enables them to reduce the concentration of water in their blood. However in order to do so they need to release important ions out of their bloodstreams, making it necessary to absorb ions such as salt back in. These two functions require energy meaning they use active transport.

Sources:
1) http://www.biology-online.org/5/1_animal_water_regulation.htm
2) http://www.cartage.org.lb/en/themes/sciences/zoology/animalphysiology/osmoregulation/osmoregulation.htm
3) http://en.wikipedia.org/wiki/Fish
4) Image http://www.incikefali.net/uremegocu-en.htm