In line with the recent article “Are viruses alive?” I would like to further explore the general nature of viruses. One question that I was recently asked was “does a virus move?” Being that viruses are not technically alive in the sense that we know it they also cannot move in a self-directed manner. This is in stark comparison to some other microbes such as Schistosoma cercariae, a parasitic worm, which is capable of burrowing through intact human skin and gaining access to the vascular system within 5 minutes1. Thankfully viruses cannot do this, much to our benefit. Because of their very nature viruses cannot mechanically move in a self-directed manner and are subject to movement solely based upon environmental interactions. Essentially, they are not only hijackers who take over cellular processes for their own good, but environmental hitchhikers as well. Continue reading
Monthly Archives: April 2012
The Importance of the Human Element
As a young woman working in microbiology I often think about the field of HPV (human papillomavirus) and its impact on women. Thanks to decades of research we have discovered that HPV is a causative agent of cervical cancer (and others, but that’s another article). Even more impressive is that there is now a vaccine designed to elicit immunity against the types that most commonly cause cancer, serotypes 16 and 18. This is great news for a generation of young women who will not have to know the torture of cervical cancer and losing their ability to bear children that their mothers and grandmothers faced. Even my own family has been touched by this disease and I am very thankful that, thanks to modern diagnostics and surgery, my loved one is still here with me. Incredibly, all of these advances can be tracked to one woman who unwittingly changed the face of medicine: Henrietta Lacks. Continue reading
Filed under Book Review, HeLa, Social Outreach
Are Viruses Alive?
Česky: 3D virus chřipky English: 3D model of an influenza virus. (Photo credit: Wikipedia)
What exactly is a virus? It its most basic form, a virus is a piece of genetic material (RNA or DNA) wrapped in a protein coat called a capsid as small as a few nanometers. Some may have an extra layer of membranous envelop outside this protein shell studded with viral proteins. That’s it. Viruses are extremely simple when compared to bacteria or eukaryotic cells such as mammals or plants. They don’t have nuclei, mitochondria, or any of the other subcellular components we are used to thinking about. They don’t divide like cells, don’t generate their own energy, and are fully dependent on host cells and their proteins to replicate. In a sense, they are molecular hijackers bent on subverting host defenses, taking over host cells nucleic acid and protein processing functions, and making copies of themselves to go out and infect more cells. However, since they can’t accomplish many of the major of functions of life on their own outside of the host cell it has been debated for many years whether viruses are “alive.” Continue reading
Filed under General
The Problem with Polio
Child receiving polio vaccine. (Photo credit: Wikipedia)
Polio is a disease that has seemed to fade away in the United States since the introduction of the polio vaccine in 1955. However, this disease is alive and well outside of the US despite a strong push by international agencies such as the WHO to eradicate polio through vaccination in the last few decades. In fact, in 1988 the WHO pledged to eradicate polio by 2000, but this dream has yet to reach reality. Why is the eradication of polio less successful than the effort to eradicate Smallpox, a goal achieved in the 1970’s? These difficulties come from the nature of polio itself and the special challenges it poses. Continue reading
