Author Archives: Kate Ahn

Beauty No Longer Asleep : 30, 000 Year Old Flower Regenerated

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Video from Press TV Global News : Images of Silene stenophylla

Resurrecting ancient organisms has always been a subject of fascination for many scientists. Although it sounds like something out of a science fiction novel, this idea is becoming more and more realistic with the recent achievement of David Gilichinsky and his colleagues from the Institute of Cell Biophysics of the Russian Academy of Sciences. In February 2012, they announced that they were able to regenerate Silene stenophylla from fruits that were found in ice age squirrels’ burrows in Siberia.

Image from Flickr by jimmywayne : Arctic Tundra

S. stenophylla is a  small flowering plant that grows in the Arctic tundra of eastern Siberia and the mountains of Northern Japan. It can be found in its habitat even today, although the fruits and seeds from the burrow  are estimated to be around 30,000 years old.

 

The regeneration process took several trials and errors. Researchers initially attempted to germinate the seeds but had no success. Then they turned to the placental tissues recovered from the fruits. The placental tissue of a plant refers to the region where the eggs are fertilized and develop into seeds. With this method the scientists were able to grow more than 30 specimens which were fully viable and even able to produce new seeds upon fertilization. The regenerated plants are almost identical to S. stenophylla found today, with only slight differences in flower shape and rate of germination.

Image from Flickr by Brian Landis : Squirrel and Its Burrow

Although it is not entirely clear how the tissues stayed viable for such a long period of time, the researchers have some possible explanations. The burrows were found deep under the surface of the ground at the level of permafrost. Permafrost refers to soil that is below the freezing temperature of water for several years. Researchers hypothesized that the seeds and fruits have frozen immediately after burial and never thawed since then, thus protecting the tissue from deterioration. The seeds also had high sugar content, which could have acted as preservative to protect the seeds and provided nutrients during germination.

This is not the first time that scientists were able to revive plants from old tissues. Before this discovery, date palm plants that germinated from 2, 000 year old seeds in Israel used to be the oldest regenerated plants. A team of American researchers were also able to grow 500 year old lotus seeds into seedlings.

The work on S. stenophylla is even more astounding because it shows that tissues can stay viable for over tens of thousands of years. This means extinct plant species or even animal species could potentially be resurrected if the tissues are preserved well enough. Does this mean that we will be able to see ice age plants and mammoths in the future? This Jurassic Park idea is definitely very exciting and scientists will have to work vigorously to make it into reality.

 

References and Further Readings :

http://www.theglobeandmail.com/news/technology/science/ice-age-plant-regenerated-after-30000-years-in-fossilized-squirrel-burrow/article2344028/

http://zipcodezoo.com/Plants/S/Silene_stenophylla/

http://en.wikipedia.org/wiki/Placentation

http://en.wikipedia.org/wiki/Permafrost

http://news.bbc.co.uk/2/hi/science/nature/1843356.stm

http://www.wnd.com/2008/06/67006/

Immune Cells from Healthy Donors May Help Fight Cancer Cells in Patients

 

Image from University of Oslo : Professor Johanna Olweus and her research team

Today, it is estimated that 2 out of 5 Canadians develop some type of cancer during their lifetime. Cancer rates are increasing around the world and is becoming a major concern. Professor Johanna Olweus and her research team at the University of Oslo have recently come up with a new method to treat certain types of cancer. The treatment involves using immune cells from donors to attack cancers cells in the patient. They claim that this approach has potential to eradicate cancer forever.

 

Image from Wikipedia by Fvasconcellos : General structure of an antibody

There is no known “cure” for cancer at present, but it is managed in several different ways. Immunotherapy treatments have been quite successful for several cases. Immunotherapy for cancer usually involves introducing antibodies or performing bone marrow transplants. Antibodies are proteins produced by white blood cells that recognize specific pathogenic cells, molecules, or the infected host cells. By tagging the infected cells, antibodies allow the body’s immune system to attack only those cells and prevent further damage. However, antibody-mediated treatments are not always effective because due to its high specificity, antibody targeted against one type of cancer cell is not effective for others.

 

Image from Flickr by Microbe World : T cell (center)

Bone marrow transplants are performed for patients with leukemia or lymphatic cancer. It involves transferring the bone marrow, which produces new blood cells, and T cells from the donor. T cells are important immune cells that, like antibodies, target specific cells and perform immune responses. Host T cells do not recognize cancer cells as foreign or harmful, however, since cancer cells are in fact host’s own cells that grow and replicate uncontrollably. The added T cells recognize cancer cells both as foreign and harmful, and act quickly to eliminate them. The treatment is effective but also very dangerous at the same time; new T cells can attack normal, uninfected cells of other intestines, causing serious damage or even death.

 

Professor Olweus attempts to combine the effectiveness of the transplant treatment with the accuracy of the antibody treatment. She was able to select donated T cells that targeted cells found only in specific organs. The injected T cells killed both healthy and infected target cells, preventing the tumor from spreading any further. This could be a powerful tool for people with types of cancer such as breast or liver cancer, which affect organs that people can live without, or that can be replaced with transplants. Another advantage is that T cells are more effective in detecting abnormalities in a cell. Antibodies only scan the cell surface but T cells can analyze both inside and outside of cells, providing a higher level of accuracy.

 

The study has promising aspects, but obviously has limitations. The method doesn’t seem to work for cancers such as lung cancer where we can’t manage to live without the organ. Most people would still prefer to live with their organs intact, and it would be ideal if only the infected cells were targeted. With further research, hopefully we will be able to overcome such limitations.

 

References :

http://www.cancer.ca/quebec/about%20cancer/cancer%20statistics/cancer%20statistics%20in%20quebec.aspx

http://www.wsws.org/articles/2003/apr2003/canc-a26.shtml

http://www.sciencedaily.com/releases/2012/02/120203091815.htm

Will SAV001 Save Us from AIDS?

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Video from University of Ontario : Media Conference on FDA Approval for SAV001

Acquired immune deficiency syndrome, better known as AIDS, was introduced to human race only a few decades ago but has since become a worldwide problem. Our society faces an AIDS pandemic. Millions of lives were taken by the disease, and more are to be lost if nothing is done to help. Vigorous researches attempt to develop a better understanding of the disease and ways to fight it. Recently, Professor Chil-Yong Kang and his colleagues at the University of West Ontario announced that they have come up with SAV001, a promising vaccine for HIV, and was approved by the FDA to proceed to human testing. Although this is enlightening news, some remain skeptical as HIV vaccines did not turn out successful in the past.

To understand why HIV vaccines are so hard to design, one must understand the mechanisms of vaccines and the nature of the HIV virus.

Image from Wikipedia by Fvasconcellos : Lock and Key Mechanism of Antibody and Antigen

Vaccines promote production of antibodies by white blood cells. Antibodies physically attach to antigens, foreign, potentially harmful molecules, or cells infected by antigens. This allows the immune system to target the tagged cells and destroy them to prevent further spread and damage. Antibodies allow such high level of specificity by recognizing epitopes which are unique and characteristic parts of antigens. In short, vaccines  introduce harmless epitopes and the body produces antibodies which can be used if the real disease infects the individual later on.

 

 

Image from National Institute of Health : Mature and Immature HIV

The difficulty associated with designing an HIV vaccine is related to the fact that the epitope for this virus is very variable. There are many subtypes of HIV and a vaccine designed for specific one of them is not likely to be effective for another. The virus also has a high rate of mutation, meaning that it is possible for a virus that has been genetically modified to be harmless to mutate back to a harmful form. For such reasons previous HIV vaccine candidates either had low efficacy or actually increased the rate of infection in some of their subjects.

 

Dr. Kang explained that SAV001 works by infecting cells with HIV to produce more virus, collecting them, and purifying them with chemicals and radiation. The dead virus as a whole is injected to elicit antibody production and activation of associated immune responses. If all goes well, the vaccine may be commercialized within a few years.

Human testing consists of 3 phases where the vaccine is tested for its safety and efficacy. Phase I for SAV001 is to begin in January 2012. Will SAV001 turn out to be a success or leave us in another disappointment? Whatever the result may be research for AIDS prevention and cure must continue. It is not likely that SAV001 will be effective for all people and subtypes of the virus. And will it be accessible in terms of cost and availability for all the people who need it? Probably not. More work needs to be done to fully fight off the disease and the misery it brings throughout the world.

 

Further Reading :

http://www.vancouversun.com/health/Canadian+researchers+start+clinical+trials+vaccine+January/5887090/story.html

References :

http://communications.uwo.ca/media/hivvaccine/

http://en.wikipedia.org/wiki/Hiv_vaccine

http://www.fiercebiotech.com/topics/fda_approval_process.asp