Due to the widespread use of antibiotics and antibacterial products, many bacterial strains have developed a resistance against conventional therapeutics such as the penicillins methicillin and amoxicillin. Recent outbreaks of methicillin resistant Staphylococcus aureus (MRSA) in hospitals and schools have resulted in numerous fatalities which demonstrate the urgency for developing alternative antibiotics (Appelbaum, 2006).
Author: Metcalfe David
Date: February 2008
In the age of cancer, diabetes, and heart disease, it is a bold scientist who stakes his research career on an everyday' illness like the flu. Nigel Dimmock, Emeritus Professor of Virology at the University of Warwick, is one such scientist. A virologist by training, Professor Dimmock has spent over forty years locked in combat with the influenza virus. Now, as the UN warns of a bird flu' pandemic with the potential to kill millions, Dimmock's team is poised to deliver their final strike against influenza. According to their paper published in the journal Vaccine, they have created a protecting virus' which tackles influenza within the body. Having successfully tested their virus on ferrets, the team is hoping to commence human clinical trials in the near future.
The influenza virus is a small infectious agent which can reproduce inside bird and mammalian cells. Under a powerful microscope, each virus particle can be observed as genetic material surrounded by a protective protein coat called a capsid'.
Most vaccinations work by injecting a small amount of capsid into the body. The immune system recognises the foreign capsid and creates antibodies, which destroy the foreign material. However, a small number of specific antibodies persist in the circulation even after the vaccine has eliminated their target. When the body becomes infected by a live virus, it is recognised by the remaining antibodies which set up an intense immune response and quickly end the infection. Although this vaccination strategy works for illnesses such as polio and smallpox, influenza makes many different capsids and so can evade antibody detection.
Now, scientists may have finally outsmarted influenza. Dimmock's vaccine is itself a type of influenza virus, except his strain has been genetically engineered so that it is harmless. The genes that the virus needs for replication have been removed and, as a result, the virus cannot spread through the body or infect other people.
Although unable to harm humans, Dimmock's creation can devastate other influenza infections. It does this by infecting potential host cells and lying in wait for a harmful virus to come along. When a normal influenza strain infects one of these protected' cells, it produces proteins which are required for the protecting virus to replicate. This exploits a technology known as defective interference RNA in which a tame viral strain is used to interfere with the actions of its harmful relative. In their paper the authors write "defective RNA can only replicate when the protein or proteins it is unable to synthesize are supplied . by infectious virus." As the protecting viral genome is smaller, it is produced faster than the normal strain which is unable to compete efficiently enough for resources. "Its small size", write the authors, "may confer a replication advantage over the full-length RNA, and is responsible for the interference phenomenon."
Once the harmful infection is slowed, the body has time to develop antibodies specific for the type of capsid used by the infecting strain. As a result, the protecting virus converts every new influenza infection into a vaccine against itself and so has little to fear from changes to the viral capsid.
"Because [the] interfering vaccine acts intracellularly and at a molecular level, it should be effective against all influenza A viruses regardless of subtype," wrote the authors in their paper. Furthermore, "This raises the possibility for this technology to be used against other highly mutating viruses such as HIV.
Written by David Metcalfe
Reviewed by Nira Datta, Pooja Ghatalia
Published by Pooja Ghatalia.
In his monumental book "Collapse: How Societies Choose to Fail or Succeed" published in 2004, Jared Diamond highlights spectacular cases of environmental mismanagement leading to the collapse of societies and entire civilizations. Easter Island which was once the site of a thriving society that sculpted huge stone statues facing inland (called Moai) is one famous example. It is now a sparsely resettled island with one of the worst cases of deforestation in the world. Diamond weaves together evidence from physical sciences, economics, politics, history, biogeography and others to make the compelling point that the fate of societies and civilizations depends on energy and environmental sustainability.
The first artificial mind is closer than we think: it is already here. Many researchers have built many different types of thinking machines, yet none so far have come to become the thinking, feeling, song-singing machines that we might expect. Nevertheless, scientists have given the next generation of robots new, remarkable features, the foremost being the ability to remember and to guess.
When you think about the lowly honeybee what comes to mind? Honey? Food? A little varmint that does nothing but sting you? To the average person, taking a look at this simple creature usually does not conjure up any sense of excitement or thrill. In fact, the most exciting thing about honeybees to a human may be chasing them around with a flyswatter or, better yet, spraying chemicals at them that typically leave you in worse condition than the bee.
The brain, coming from the Greek βρεχμός, for forehead, is one of the most interesting and complex components of the body. In humans, the brain contains approximately 23 billion neurons, with some connected to another 10,000 neurons. The brain also possesses an astounding variety of roles, from the management of behavior, to the control and execution of movement. However, many aspects of the brain are shrouded in mystery. One particularly interesting case involves a student from the University of Sheffield.
Dr. Judah Folkman, surgeon and researcher who pioneered the way to fight cancer by starving tumors of their blood supply, died at age 74 on January 14, 2008. Folkman was changing planes at a Denver airport while making his way to Vancouver, Canada for a conference when he succumbed to a heart attack, said family members. Where else would a man who has changed the course of modern medicine be going at his death if not to a scientific meeting?