Friday, 1 May 2015

Genetic engineering.

Genetic engineering

Genetic engineering is the process by which a functional gene is introduced into a new tissue or organ in order for it to express a new characteristic or feature. Genetic engineering started in the early 1990's by a river of attempts in many fields of medicine. 



You are going to see if there is any disease which could be cured by applying this type of engineering. We have chosen the following and common diseases:
  • Diabetes
  • Hemophilia
  • Cancer
  • Alzheimer
  • Aids 

Diabetes.

Diabetes is a group of metabolic diseases in which there are high blood sugar levels over a prolonged period.
  • How diabetes appears?
Diabetes is a disorder of metabolism. The digestive tract breaks down carbohydrates into glucose, which enters to the bloodstream. With the help of the hormone insulin, cells throughout the body absorb glucose and use it for energy. Diabetes develops when the body doesn't make enough insulin or is not able to use insulin effectively, or both.

  • How could genetic engineering cure diabetes?
Investigators in type 1 diabetes precipitated in this promising area. Sadly, the reality of genetic engineering did not match its promise, and scientific research in this area declined dramatically in recent years relative to a decade ago. However, progress in other medical disciplines over the same time period has recently turning back on interest in this otherwise promising concept. More recently, in an attempt to overcome the limitation of insufficient insulin due to a lack of beta cells within the body, investigators have sought to restore the this ability in type 1 diabetes patients via genetic reprogramming of various form of cells into insulin producing cells. This list would include turning both adult stem cells as well as embryonic stem cells (ESC) into insulin-producing cells.


Another approach involves the introduction of the insulin gene into target tissues. Finally, the concept of improving existing beta (islet) cells by genetic engineering has also been attempted; this, involving the introduction of genes into islets that would make them resistant to immune destruction. While advances in each of these approaches have occurred over the years, a successful means for using genetic engineering to allow for avoidance of exogenous insulin replacement is not currently available, thereby remaining a hope for the future.



Hemophilia.

Hemophilia is an inherited genetic disorder that disrupts blood clotting.

  • How appears hemophilia? 
Hemophilia appears differently depending on the type it is. There are two types:

-Hemophilia A is caused by a deficiency in clotting factor VIII; it is the most common type. The treatment of choice is viral attenuated or recombination Factor VIII concentrate. The most recent preparations, unlike previous products, do not use the blood protein albumin as an ingredient; this should completely eliminate the former potential risk for transfusion of any blood-borne infectious agents.


-Hemophilia B is produced by a deficiency in clotting factor IX. The European Commission approved a plasma-derived Factor IX concentrate, for continuous intravenous infusion which will help patients maintain a minimum and predictable level of Factor IX. Factor concentrates are either produced from the plasma in blood donations, or synthetically by recombination genetic engineering. The treatment is a highly purified viral inactivated Factor IX concentrate. Nowadays, with the introduction of recombination factor therapies, this risk has become a theoretical one.


  • How could genetic engineering cure hemophilia?
Genetically engineered clotting factor that controls hemophilia in animals offers a potential treatment for human hemophilia. In the recent study some researchers have genetically engineered coagulation factor into an alternative that shows promise as a treatment for hemophilia and other bleeding problems.
Rodney A. Camire was in charge of this project with the help of some professionals. During their research they infused the new treatment that consisted on rediscover factor Xa (coagulation factor which in its normal shape is not very effective as therapy); they infused it into mice that suffered the disease, their engineered factor Xa was triumphant in lowering blood loss and restoring blood clotting ability.
They also designed differing alters the shape of Xa to make it more safe; when this variant changes it interacts with another clotting factor and this increases the functioning of the protein which helps in stopping the bleeding.





Cancer.

Cancer, to begin with, is a combination of many diseases. In all the types of cancer, some cells of a part of the body start to divide without control and disseminate in the surrounding areas. It can be suffered in almost every part of the body, formed by trillion of cells. Normally, these cells grow; reproduce and when they are damaged or dead, the new cells replace them. But when cancer affects a part of the body, this process is uncontrolled. Cells become abnormal, and old and damaged cells who are supposed to dead, survive; and new and unnecessary cells are created. These cells keep reproducing without control and this create tumors. 
  • How cancer appears?
Cancer is a genetic disease, i.e.: it is caused because of changes in the genes that control the way our cells work, more accurately, the way they grow and divide.



In each person, cancer has a different combination of genetic changes and when the cancer is still growing, this combination keeps changing. And even in the same tumor, genetic changes can vary, and this is why it is such a complicated disease.
  •  How could genetic engineering cure cancer?
Before genetic engineering, cancer was tried to be cured with the destruction of cancer cells with chemotherapy, radiation or surgery, but genetic engineering is another strategy that has reduced tumors in a significant percentage. Some methods are: 

  1.  Immunologic therapy: Based on the ability of the immune system to fight against cancer. For this, antigens are introduced into tumor cells allowing immune cells to recognize tumor cells.
  2.  Introduction of drug activator genes or suicide gene therapy: Consists on the selective introduction of genes in tumor cells and not in the rest of the cells, what makes drug substances to be toxic. This combined with enzymes, makes tumor cells to die.
  3. Standardization of the cell cycle: Consists on the deactivation of mutated oncogenes, or the activation of anti-oncogenes or suppressor genes of inactive tumors. The bad thing of this method is the need of great quantities of the virus. 



Alzheimer.
               
Alzheimer’s disease is a chronic neurodegenerative disease. It is characterized by the memory loss and other metal capacities as neurons are damaged and die. It usually affects people from 65 years old and older.

  • How Alzheimer appears?

Alzheimer disease has been obstructed by the lack of information about the biology of this. Only recently have scientists confirmed that amyloid plaques are associated with the disease, and they still debate whether they are causative or symptomatic. Experts agree that in the vast majority of cases, Alzheimer's, like other common chronic conditions, probably develops as a result of complex interactions among multiple factors, including age, genetics, environment, lifestyle, and coexisting medical conditions.


  • How could genetic engineering cure Alzheimer?


It is said to be an incurable disease but experts have improved a technique of interference of ARN which deactivates the genes that are responsible for this disorder. This technique was tested with mice, and a 80% of them were cured. Also, neurosurgeons, have implanted cells modified genetically directly into the patient’s brain. It takes several years to see the final result, if there has been an improvement. Scientists affirm, there is a possibility to cure this disease.
Mostrando alzheimer_terapia_genica.jpg



AIDS.

What we know as AIDS is the human immunodeficiency virus infection and acquired immune deficiency syndrome, a spectrum of conditions caused by infection with the HIV.

Resultado de imagen de aids


  • How does AIDS appears?

AIDS appears, after the infection, as an influenza-like illness, followed by a period without symptoms, and then starts to interfere with the immune system, making the patient a person that easily has diseases as infections, tumors or tuberculosis. The last stage, the one referred to as AIDS, is when infections in the lung (pneumocystis pneumonia), severe weight loss, cancer (Kaposi’s sarcoma) or other AIDS diseases appear.

  • How could genetic engineering cure AIDS?
Knowing how the mechanisms that rule the function of genes work is the key to solve or correct some modifications in the DNA, which are the origin of many diseases, like for example, the HIV infection. The genetic engineering consists on introducing genes that correct that modifications. There are two types:
  1. Somatic engineering; in this therapy the changed genes are only for the patient of this therapy and you can only add genetic material or substitute.
  2. Germ engineering; in this therapy the changes in the patient are transmitted to the descendants and you do the same than in the first type, add or substitute virus, retrovirus, adenenovirus, etc.





To sum up, not every mentioned disease can be cured definitively using genetic engineering, such as Alzheimer’s or Diabetes’ ones but they can be treated in order to reduce the causes of the illness to make the minor damage.  For example in hemophilia, the main goal is achieved, stopping the bleeding; and in AIDS, the patient has more possibilities of having a life closer to their old normal lives. Genetic engineering can be very useful and is going to be one of the main factors in the discovery of new medicines and the end of many diseases.

Javier Cuenca, Patricia Ordóñez, Johann Cosme, Cristina Larrea, 4ºA.


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