Search This Blog

Showing posts with label Cell. Show all posts
Showing posts with label Cell. Show all posts

Thursday, March 10, 2011

Gene Therapy

A diagram explaining Gene Therapy
Imagine the treatment of a cancer patient. It is typically a long string of doctors appointments, surgeries, and medications such as chemotherapy. But what if there was a way to treat cancer with a simple injection? It seems incredible, and yet this is the aim of a new type of medical treatment called gene therapy. Not only would gene therapy treat cancer, but it could also treat cystic fibrosis, familial hypercholesterolemia, HIV/AIDS, gaucher disease, hearing loss, and could allow patients with circulatory problems in the legs to avoid amputation.

So, how would this incredible process work? It would begin on a molecular level. All of the aforementioned diseases and complications are caused by imperfections and mutations of the DNA. These are obviously very hard to treat with medications, and are typically hereditary. They can affect almost any part of the DNA. It is clearly quite hard to change a gene that is written into each and every cell in the human body, and coming up for a cure for these diseases has always been quite daunting. This is where gene therapy comes in. Gene therapy is the use of genes as treatment or prevention for diseases.

Using genes as a treatment? As fantastical as it sounds, this is the reality of gene therapy.  A "normal" gene is put into the genome in place of an "abnormal" gene which causes a disease or disfunction. This is done with several different treatments which fall under two headings: Germ-line gene therapy and somatic gene therapy. Germ-line gene therapy is when genes are introduced into reproductive cells or into embryos, so that the child will not have genetic abnormalities. On the other hand, somatic gene therapy is when therapeutic genes are inserted into cells to replace the current DNA or to make a protein/substance that is not present or not working in the patient. Most current research is developing somatic gene therapy.

Somatic gene therapy usually works via a "vector". The vector delivers the new gene to the patients cells. These vectors are almost always a virus which has had the infectious DNA replaced with the proper gene. These are either a retrovirus (such as HIV, which works well in dividing cells), an Adenovirus (such as the common cold, which works well in non-dividing cells), an Adeno-associated virus (which inserts DNA at a specific singular site on chormosome 19) or Herpes simplex virus (typically causes cold sores). There are new ways of developing gene therapy, including introducing the DNA directly to the cells, creating an artificial lipid with a water-based core which can travel directly through a cell membrane to deliver the gene, chemically linking the DNA to a molecule that attaches to the cell receptors, or even adding a 47th chromosome, which would not affect the cell in any way other than changing the defective gene.

Like any advancement in science, there are some questions and possible complications that come up when discussing gene therapy. If we put aside the omnipresent issue of "playing god", there are still a few problems. The primary problem is the use of viruses. Many scientists and researchers fear that one of the viruses injected into the DNA will go awry. Instead of being completely removed, the original virus would still retain its own DNA and begin infecting people. Although this is a justified concern, I believe that the benefits far outweigh the risks. If the makers of the injections are thorough in their testing, the company can have a product that is both safe and infinitely helpful to the modern world.

Check out this game about gene therapy!





Thursday, December 16, 2010

Cellular Respiration Video

Here is a video that Megan, Peter, and I made. It explains the process of cellular respiration using both claymation and video clips. Enjoy!

Tuesday, November 23, 2010

Allergic to your cell phone?

When you think about cell phones, what comes to mind? Texting, perhaps, the iphone, or even radiation. But an allergic reaction? In the past few years, scientists have been finding rashes on the faces of teenagers and adults, along the jawline. The cause of these rashes was a mystery, until recently. The New York Times released an article this Tuesday, which linked the rash to Nickel found in cell phone casing.

According to Web MD, "A nickel allergy is a skin reaction that develops after exposure to nickel or items containing the metal." This essentially means that a nickel allergy is caused by touching or wearing nickel for a long period of time. In America, 3% of men have this allergy and 20% of women. This is because many items of jewelry contain nickel. Therefore, the jewelry wearers are more exposed to the nickel. This is the same process that occurs with cell phone users. However, with a cell phone user it is called, "Contact dermatitis with a Nickel allergy". If a person is constantly talking on their cell phone, the face can become hypersensitive to nickel. This hypersensitivity becomes an allergy.

A nickel allergy has several, rather similar, symptoms. The most common are:

  • A rash where the nickel has touched the skin
  • Itching
  • Red areas of skin
  • Dry areas of skin (these can look like burns)
  • Blisters
This allergy can come from other objects as well. Some examples are watchbands, zippers, belt buckles, hairpin, dental fillings, prosthetics, and even the frames of glasses. People with severe nickel allergies must limit their contact with some of these objects, and avoid eating oatmeal, chocolate, nuts, beans and dried fruit; which contain small amount of nickel. 

However, it is possible to treat this allergy. Doctors recommend using steroid creams, such as cortisone, and preventing any further contact by using a headset.



Link to a brief Masher video summarizing the cell phone issue:
http://www.masher.com/player.jsp?key=0dbe76c7-a2bc-cb73-63d8-0000effb001b&adscheme=0



Sources:
http://www.nytimes.com/2010/11/23/health/23really.html?_r=1&ref=health
http://www.webmd.com/allergies/nickel-jewelry-allergy
http://www.businessweek.com/lifestyle/content/healthday/645796.html
http://www.mayoclinic.com/health/nickel-allergy/DS00826/DSECTION=symptoms
http://www.cmaj.ca/cgi/content/full/178/1/23
http://allergies.about.com/b/2008/10/16/mobile-phone-allergy.htm
http://preparednesspro.files.wordpress.com/2009/06/person-on-cell-phone.jpg


Monday, October 25, 2010

Cell Community Project - A Band!

For our Bio Blog posts this week we had to use Glogster to compare different cell components to different parts of a certain community. The community that I chose was a band. The first page is below, and clicking on the black and white labels will bring you to a page about a specific part of the cell.