A QUANTUM OF SCIENCE
Nanoscale metals in paint block WiFi signals - with big implications for mobile users
WiFi is everywhere these days, but less than a decade ago it was rare - and less than two decades ago it did not exist at all. Wireless technology was invented in 1991 by AT&T/Lucent (now Agere) but the current standard technology was not patented until 1996 by an Australian company called CSIRO. The Wi-Fi Alliance, a loose affiliation of over 300 companies manufacturing wireless products or services, was formed in 2000 to ensure standardization of WiFi technologies. The first fully-wireless campus was Carnegie-Mellon in 1994 and the first free-WiFi airport was Pittsburgh International in 2003. In 2005 an undergraduate communications class at the University of Washington mapped all the wireless networks in the Seattle area (5,225 at that time). But what is WiFi?
Though the term suggests "Wireless Fidelity" by analogy to Hi-Fi, the WiFi Alliance (who owns the term) officially states that the term is just a brand name and means nothing. In practice, WiFi is a short-range radio signal, an electromagnetic wave that propagates through space in all directions over a distance that decreases quadratically from its source. Depending on the power of the signal it could travel as little as 120 feet (the average home router) and as much as several kilometers using outdoor line-of-sight directional antennas. The power of the signal is limited by the FCC and is generally up to 1 Watt (compare this with an AM radio station at around 50,000 watts for a sense of scale). The frequency is set by industry standard: 2.4 gigahertz (2.4 billion waves per second) is the current standard. As a consequence, the wavelength of WiFi is in the low millimeter range.
Despite the fantastic growth in WiFi hardware and accessibility over the last decade, little attention has been given to controlling WiFi broadcasting. Some information should not be shared freely, such as for businesses who use WiFi internally but which would rather not share their internal emails with the world. This is especially true for businesses who handle confidential information, such as banks and hospitals. Governmental WiFi networks are obvious targets for WiFi hacking as well, and increasing home WiFi network prevalence makes identity theft from unsecured routers a growing concern for millions of consumers.
While many software security solutions exist to protect networks from illicit access, no system is hack-proof, so methods of preventing the propagation of wireless signals beyond a certain boundary are increasingly important. WiFi "jammers" are devices that function by transmitting a signal in the same wavelength range as WiFi (millimeter) but with opposite sign, creating destructive interference with the WiFi signal. They are illegal in many countries (including the US) nominally because they interfere with emergency-response but more likely because they could theoretically prevent law enforcement communications.
Recently, researchers at the University of Tokyo published a paper detailing their work at blocking wireless transmissions with nanoscale magnets – tiny metallic crystals that can be suspended in an oil/latex matrix (AKA paint) and coated onto walls or other surfaces. These tiny magnetic particles absorb electromagnetic energy in the millimeter wavelength (the same range as wireless signals) and a process called gyromagnetic resonance (or "natural" resonance) results, effectively dissipating the wireless signal into tiny, random magnetic resonances that block further propagation of the electromagnetic wave through space. In this case the nanoscale magnets are composed of aluminum-doped iron oxide crystals, which are unique in that they have the highest gyromagnetic coefficient recorded to date. The researchers also noted that both iron oxide and aluminum were inexpensive, non-toxic materials and thus eminently suitable for this application. Additionally, this nanomagnetic paint will block cell phone signals as well, since those operate at a lower frequency than WiFi.
One area that is not affected by this innovation is human health. The World Health Organization did a study on the impact of radiofrequency emanations on human health in 2007, with the finding that normal levels of RF permitted by most industrialized nations have no measurable impact on health or development - so don’t order a few gallons of anti-WiFi paint thinking it will protect you from cancer. Still, while movie theatres, restaurants and museums might hail this "quiet" technology as a welcome breakthrough, consumers’ ever-increasing use of wireless devices is unlikely to wane any time soon – even if some Wi-Fi hotspots will soon become No-Fi coldspots.
For more information:
Anti-Wi-Fi paint keeps your wireless signal to yourself (Yahoo Tech)
University of Washington WiFi map of Seattle (2005)
Synthesis of an Electromagnetic Wave Absorber for High-Speed Wireless Communication (Namai et al)
A Millimeter-Wave Absorber Based on Gallium-Substituted -Iron Oxide Nanomagnets (Ohkoshi et al)
World Health Organization report on Health Consequences of Wireless Networks
WiFi (Wikipedia article)
Electromagnetic interference in the 2.4GHz range (Wikipedia)
The Physics of WiFi (WiFi Forum)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Monday, October 5, 2009
Thursday, October 1, 2009
Who Killed T-Rex?
A QUANTUM OF SCIENCE
The King of the Dinosaurs may have been done in by a microscopic parasite
When paleontology researchers from major universities and museums around the world started to compare notes on the bone structures of particular specimens, they noticed something strange: cavities. In specific, Tyrannosaurus Rex cavities. Of the 61 specimens examined, 15% had significant lesions in the mandible (jaw bone), most of them occurring on both sides of the jaw. The earlier interpretation – that these were the result of intraspecies predation – was ruled out by comparison to the jaws of crocodiles, which form significant scar tissue when punctured by the teeth of other crocodiles. There was no sign of scarring, the cavities were simply eroded into the jaw bone, characteristic of a microbiological agent.
Researchers concluded that based on the similarities between the morphology and pattern of lesions in the T-rex specimens to those found in modern falcons, a protozoan known as Trichomonas gallinae was most likely responsible. The protozoan could have been transmitted either from infected prey or through violent contact between T-rex muzzles such as might be imagined in instance of either displays of dominance or outright cannibalism. Once the disease progressed to the stage found in many of the examined fossil specimens, feeding would become problematic or even impossible. In another modern equivalent, the Tasmanian Devil is actually starving itself into extinction following a face-biting behavior that spreads an oral cancer between individuals. While not conclusive in their theory that trichomonosis starved the T-rex to death, evidence is accumulating that it may have been the case for some populations of the dinosaur, and the potential exists that scientists may be able to extract DNA from these fossils and provide a more solid conclusion in the near future.
For more information:
Common Avian Infection Plagued the Tyrant Dinosaurs (Wolff et al)
Trichomonas gallinae (Wikipedia)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
The King of the Dinosaurs may have been done in by a microscopic parasite
When paleontology researchers from major universities and museums around the world started to compare notes on the bone structures of particular specimens, they noticed something strange: cavities. In specific, Tyrannosaurus Rex cavities. Of the 61 specimens examined, 15% had significant lesions in the mandible (jaw bone), most of them occurring on both sides of the jaw. The earlier interpretation – that these were the result of intraspecies predation – was ruled out by comparison to the jaws of crocodiles, which form significant scar tissue when punctured by the teeth of other crocodiles. There was no sign of scarring, the cavities were simply eroded into the jaw bone, characteristic of a microbiological agent.
Researchers concluded that based on the similarities between the morphology and pattern of lesions in the T-rex specimens to those found in modern falcons, a protozoan known as Trichomonas gallinae was most likely responsible. The protozoan could have been transmitted either from infected prey or through violent contact between T-rex muzzles such as might be imagined in instance of either displays of dominance or outright cannibalism. Once the disease progressed to the stage found in many of the examined fossil specimens, feeding would become problematic or even impossible. In another modern equivalent, the Tasmanian Devil is actually starving itself into extinction following a face-biting behavior that spreads an oral cancer between individuals. While not conclusive in their theory that trichomonosis starved the T-rex to death, evidence is accumulating that it may have been the case for some populations of the dinosaur, and the potential exists that scientists may be able to extract DNA from these fossils and provide a more solid conclusion in the near future.
For more information:
Common Avian Infection Plagued the Tyrant Dinosaurs (Wolff et al)
Trichomonas gallinae (Wikipedia)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Wednesday, September 30, 2009
Building Blocks
A QUANTUM OF SCIENCE
Geopolymers turn industrial wastes into energy-efficient super-building materials
Ordinary Portland Cement (OPC) is among the most common building materials on earth. Originating in the early British Industrial Revolution, it is used today in concrete, mortar, stucco and grout. An estimated 2.6 billion tons of it are made worldwide every year. Portland cement manufacture is a highly energy-intensive process involving high-temperature kilns, uses vast amounts of natural resources such as limestone, and produces not only considerable environmental damage in the form of alkaline run-off but also 5-8% of the total carbon emissions worldwide. But is there an alternative for this critical industrial material?
Geopolymers might just be that alternative. This new branch of industrial science explores methods for turning industrial waste products into highly energy-efficient materials with advanced properties. One of those industrial wastes is fly ash, the black powder left over from coal-burning power plants. At present, fly ash disposal is a tremendous industry problem with tremendous environmental impact. Recently, however, scientists have developed ways to use fly ash instead of limestone or other silicas and carbonates for the manufacture of concrete. These materials, known as geopolymers, not only make use of an abundant raw material but also present unique advantages for industrial use. Geopolymer concrete sets much faster than OPC, shows greater mechanical strength, shrinks less, is more resistant to corrosion and can withstand far higher temperatures without breaking down. Perhaps best of all, the production of geopolymer concrete reduces carbon emission by 90% compared to an equivalent amount of OPC.
Geopolymers are poised to provide other advantages as well. The mechanical strength and improved resistance to corrosion and heat make geopolymers ideal for sequestering environmentally harmful compounds such as arsenic, cadmium, chromium, lead, dioxins and even radioactive wastes. Challenges remain, however. Most importantly, long-term durability and stability data has yet to be generated, though ongoing tests suggest favorable performance compared to OPC. There are also existing regulations for OPC-based concrete products that would have to be modified if geopolymers are to gain acceptance and use worldwide, especially in the European Union where such regulations are strict. Still, the prospect of using industrial waste to make one of the most-used building materials on earth with improved characteristics while using less energy and adding less carbon to the planet seems an ideal solution.
For more information:
New Geopolymer Concrete Technology Created (R&D Magazine)
The role of inorganic polymer technology in the development of 'green concrete' (Duxson et al)
Geopolymerisation: A review and prospects for the minerals industry (Komnitsas et al)
Reaction mechanisms in the geopolymeric conversion of inorganic waste to useful products (Van Deventer et al)
Portland Cement (Wikipedia)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Geopolymers turn industrial wastes into energy-efficient super-building materials
Ordinary Portland Cement (OPC) is among the most common building materials on earth. Originating in the early British Industrial Revolution, it is used today in concrete, mortar, stucco and grout. An estimated 2.6 billion tons of it are made worldwide every year. Portland cement manufacture is a highly energy-intensive process involving high-temperature kilns, uses vast amounts of natural resources such as limestone, and produces not only considerable environmental damage in the form of alkaline run-off but also 5-8% of the total carbon emissions worldwide. But is there an alternative for this critical industrial material?
Geopolymers might just be that alternative. This new branch of industrial science explores methods for turning industrial waste products into highly energy-efficient materials with advanced properties. One of those industrial wastes is fly ash, the black powder left over from coal-burning power plants. At present, fly ash disposal is a tremendous industry problem with tremendous environmental impact. Recently, however, scientists have developed ways to use fly ash instead of limestone or other silicas and carbonates for the manufacture of concrete. These materials, known as geopolymers, not only make use of an abundant raw material but also present unique advantages for industrial use. Geopolymer concrete sets much faster than OPC, shows greater mechanical strength, shrinks less, is more resistant to corrosion and can withstand far higher temperatures without breaking down. Perhaps best of all, the production of geopolymer concrete reduces carbon emission by 90% compared to an equivalent amount of OPC.
Geopolymers are poised to provide other advantages as well. The mechanical strength and improved resistance to corrosion and heat make geopolymers ideal for sequestering environmentally harmful compounds such as arsenic, cadmium, chromium, lead, dioxins and even radioactive wastes. Challenges remain, however. Most importantly, long-term durability and stability data has yet to be generated, though ongoing tests suggest favorable performance compared to OPC. There are also existing regulations for OPC-based concrete products that would have to be modified if geopolymers are to gain acceptance and use worldwide, especially in the European Union where such regulations are strict. Still, the prospect of using industrial waste to make one of the most-used building materials on earth with improved characteristics while using less energy and adding less carbon to the planet seems an ideal solution.
For more information:
New Geopolymer Concrete Technology Created (R&D Magazine)
The role of inorganic polymer technology in the development of 'green concrete' (Duxson et al)
Geopolymerisation: A review and prospects for the minerals industry (Komnitsas et al)
Reaction mechanisms in the geopolymeric conversion of inorganic waste to useful products (Van Deventer et al)
Portland Cement (Wikipedia)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Monday, September 28, 2009
Prostate cancer - STD?
A QUANTUM OF SCIENCE
Mouse virus is implicated in causation of #2 male cancer killer
Prostate cancer strikes one in six American men, and is the second most likely cancer to cause death in men. New research now suggests that prostate cancer may in fact be linked to a virus that could be sexually transmitted.
The suspect is xenotropic murine leukemia-related virus (XMRV), a gammaretrovirus similar to viruses known to cause cancer in animals. Retroviruses are known cancer-causing agents because they integrate themselves into the host’s genetic material; when this takes place in or near a segment of DNA associated with a gene that controls growth, cancer – unrestricted cell growth – can result. Some retroviruses also contain cancer-causing genes of their own, such as the src gene in Rous sarcoma virus. The three most common cancer-causing viruses are human papilloma virus (HPV), Hepatitis B virus (Hep B), and the Eppstein Barr Virus (EBV).
Scientists working in collaboration between Columbia University and the University of Utah found XMRV in over 25% of prostate tissue samples, especially malignant ones. Moreover, the virus was found to be significantly more infective when present in semen. Another semen component, acid phosphatase, increased XMRV infectivity of human prostate cells by over 100-fold.
The strongest theory at present for the biology of XMRV-linked prostate cancer suggests that an infected man has viral particles present in his genital tract and deposits them in his partner when he has unprotected intercourse. The acid phosphatase in the semen activates the viral particles and makes them substantially more infective, making the partner at risk of transmitting the virus during future intercourse.
More research is needed to substantiate this theory, but this discovery could also lead to new treatments based on anti-retroviral therapies already known to medicine.
For more information:
Viral Cause For Prostate Cancer? (New Scientist)
Retroviruses (Wikipedia)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Mouse virus is implicated in causation of #2 male cancer killer
Prostate cancer strikes one in six American men, and is the second most likely cancer to cause death in men. New research now suggests that prostate cancer may in fact be linked to a virus that could be sexually transmitted.
The suspect is xenotropic murine leukemia-related virus (XMRV), a gammaretrovirus similar to viruses known to cause cancer in animals. Retroviruses are known cancer-causing agents because they integrate themselves into the host’s genetic material; when this takes place in or near a segment of DNA associated with a gene that controls growth, cancer – unrestricted cell growth – can result. Some retroviruses also contain cancer-causing genes of their own, such as the src gene in Rous sarcoma virus. The three most common cancer-causing viruses are human papilloma virus (HPV), Hepatitis B virus (Hep B), and the Eppstein Barr Virus (EBV).
Scientists working in collaboration between Columbia University and the University of Utah found XMRV in over 25% of prostate tissue samples, especially malignant ones. Moreover, the virus was found to be significantly more infective when present in semen. Another semen component, acid phosphatase, increased XMRV infectivity of human prostate cells by over 100-fold.
The strongest theory at present for the biology of XMRV-linked prostate cancer suggests that an infected man has viral particles present in his genital tract and deposits them in his partner when he has unprotected intercourse. The acid phosphatase in the semen activates the viral particles and makes them substantially more infective, making the partner at risk of transmitting the virus during future intercourse.
More research is needed to substantiate this theory, but this discovery could also lead to new treatments based on anti-retroviral therapies already known to medicine.
For more information:
Viral Cause For Prostate Cancer? (New Scientist)
Retroviruses (Wikipedia)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Lunar Oasis
A QUANTUM OF SCIENCE
Three separate space probes find spectral evidence of lunar water
In October 2008, India launched the Chandrayaan-1, its first lunar probe. The Chandrayaan-1 was designed to spend the following two years mapping the surface of the moon, but on August 31, 2009 contact with the probe was lost. Before then, however, the probe generated over 70,000 high-resolution images covering almost the entirety of the moon’s surface. Even more importantly, its sensors revealed a curious observation: ice.
Light absorbance is the characteristic interaction of different wavelengths of light with particular chemical elements. If a specific element is present in a material, it will absorb light of a characteristic wavelength. The same is true for simple compounds, such as water. With this technique, specific elements and often simple compounds can be detected even at interstellar distances, allowing scientists to deduce the chemical composition of distant stars. One compound that has a particularly characteristic absorbance spectrum is water. The Chandrayaan’s sensors reported a spectrum containing absorbance peaks consistent with water, and soon afterwards the observations were repeated by NASA’s Cassini and Deep Impact space probes.
Isn’t the moon a dry desert, though? Apollo astronauts certainly believed so when they landed on the moon in 1969, and "moon rocks" brought back from the lunar landing seemed to confirm it – except that it was assumed that any humidity found in the samples were the result of earth water contamination. Now, scientists theorize that water exists on the lunar surface in extremely thin layers just millimeters below the surface. The source and amount of water are still matters for further investigation, but scientists theorize that water on the surface of the moon might "migrate" as the moon is alternately warmed and cooled by exposure to the sun, until it ends up in deep lunar craters. These craters were recently found to be at a lower temperature than the surface of Pluto, so water ending up there would be "stuck" and accumulate over time.
The existence of water on the moon is particularly exciting not only because it was contrary to decades-old assumptions but also because it creates new possibilities. If it could be effectively harvested, lunar water could help sustain a human outpost on the lunar surface. Even more daringly, some have suggested that hydrogen and oxygen derived from electrochemically "splitting" this water could serve as rocket fuel. Rockets launched from the moon would require substantially less fuel because the moon’s gravity is so much less than that on Earth, leading to speculation that lunar launches could facilitate a new era in the exploration of the solar system, especially Mars.
For more information:
India's first lunar probe fails after less than a year (New Scientist)
Widespread water may cling to moon's surface (New Scientist)
How astronauts could 'harvest' water on the moon (New Scientist)
What Do Spectra Tell Us? (NASA)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Three separate space probes find spectral evidence of lunar water
In October 2008, India launched the Chandrayaan-1, its first lunar probe. The Chandrayaan-1 was designed to spend the following two years mapping the surface of the moon, but on August 31, 2009 contact with the probe was lost. Before then, however, the probe generated over 70,000 high-resolution images covering almost the entirety of the moon’s surface. Even more importantly, its sensors revealed a curious observation: ice.
Light absorbance is the characteristic interaction of different wavelengths of light with particular chemical elements. If a specific element is present in a material, it will absorb light of a characteristic wavelength. The same is true for simple compounds, such as water. With this technique, specific elements and often simple compounds can be detected even at interstellar distances, allowing scientists to deduce the chemical composition of distant stars. One compound that has a particularly characteristic absorbance spectrum is water. The Chandrayaan’s sensors reported a spectrum containing absorbance peaks consistent with water, and soon afterwards the observations were repeated by NASA’s Cassini and Deep Impact space probes.
Isn’t the moon a dry desert, though? Apollo astronauts certainly believed so when they landed on the moon in 1969, and "moon rocks" brought back from the lunar landing seemed to confirm it – except that it was assumed that any humidity found in the samples were the result of earth water contamination. Now, scientists theorize that water exists on the lunar surface in extremely thin layers just millimeters below the surface. The source and amount of water are still matters for further investigation, but scientists theorize that water on the surface of the moon might "migrate" as the moon is alternately warmed and cooled by exposure to the sun, until it ends up in deep lunar craters. These craters were recently found to be at a lower temperature than the surface of Pluto, so water ending up there would be "stuck" and accumulate over time.
The existence of water on the moon is particularly exciting not only because it was contrary to decades-old assumptions but also because it creates new possibilities. If it could be effectively harvested, lunar water could help sustain a human outpost on the lunar surface. Even more daringly, some have suggested that hydrogen and oxygen derived from electrochemically "splitting" this water could serve as rocket fuel. Rockets launched from the moon would require substantially less fuel because the moon’s gravity is so much less than that on Earth, leading to speculation that lunar launches could facilitate a new era in the exploration of the solar system, especially Mars.
For more information:
India's first lunar probe fails after less than a year (New Scientist)
Widespread water may cling to moon's surface (New Scientist)
How astronauts could 'harvest' water on the moon (New Scientist)
What Do Spectra Tell Us? (NASA)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Wednesday, September 16, 2009
Gene Therapy cures color-blindness in adult primates
A QUANTUM OF SCIENCE
This is the single biggest success story for gene therapy to date. Instead of reiterating, I will simply say: go read the linked articles and marvel that this could have come to pass in your lifetime.
"Looking back on this in 50 or 100 years, it will be a landmark paper even then."
-David Williams, director of the University of Rochester’s Center for Visual Science
FOR MORE INFORMATION:
Gene Therapy Cures Color-Blind Monkeys (Wired Science)
Original article: Gene therapy treatment of color blindness in adult primates (Mancuso et al)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
This is the single biggest success story for gene therapy to date. Instead of reiterating, I will simply say: go read the linked articles and marvel that this could have come to pass in your lifetime.
"Looking back on this in 50 or 100 years, it will be a landmark paper even then."
-David Williams, director of the University of Rochester’s Center for Visual Science
FOR MORE INFORMATION:
Gene Therapy Cures Color-Blind Monkeys (Wired Science)
Original article: Gene therapy treatment of color blindness in adult primates (Mancuso et al)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Antioxidants Curb Cancer's Spread
A QUANTUM OF SCIENCE
New research shows reactive oxygen breaks down cell walls and helps cancer spread
Malignant cancer tumors have a unique characteristic: they can release tumor cells into the lymphatic system and cause tumors to grow elsewhere in the body, even in tissues or organs totally unrelated to those that were the original source of the tumor. This process is called metastasis, and sometimes forces doctors to use whole-body or systemic anti-cancer treatments when a localized treatment targeting a single tumor would be both more effective and far easier on the patient. Now scientist are advancing understanding of how metastasis occurs, and how to prevent it.
Researchers at Burnham Institute for Medical Research in La Jolla, California recently reported that reactive oxygen species were key players in the cellular process of metastasis. Reactive oxygen species (ROS) include superoxide, hydrogen peroxide and other forms of oxygen generated by the body’s normal functions. Some uses of ROS are beneficial, such as when the immune system generates ROS to kill invading cells. In cancerous cells, however, ROS help form lesions and break down cell walls, aiding in the spread of tumor-forming cells. Researchers have isolated a scaffold protein called Tks5 (for Tyrosine Kinase Substrate) which is concentrated in extruded lesions of tumor cells, called podosomes (or invadopodia in some papers). Tks5-rich cells rapidly produce ROS and form lesions that facilitate the spread of tumorous cells throughout the body. In their paper, Burnham scientists show that cells lacking the gene for Tks5 production are substantially inhibited from forming metastatic tumors, and treating the tumor cells with antioxidants similar suppresses the activity of Tks5, resulting in smaller tumors, fewer lesions/podosomes and a substantial decrease in extruded (metastatic) cells.
An example of tumor size reduction in cells lacking the Tks5 gene (4.20 and 4.24):
This paper is an exciting advance in the understanding of the basic processes of malignant cancer. If podosome formation and metastasis can be reduced by either antioxidant treatments or drugs that target Tks5, huge advances can be made in reducing the mortality associated with highly-metastatic malignant cancer.
For more information:
Reactive Oxygen’s Role in Metastasis
A role for the podosome/invadopodia scaffold protein Tks5 in tumor growth in vivo (Blouw et al)
Metastasis (Wikipedia article)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
New research shows reactive oxygen breaks down cell walls and helps cancer spread
Malignant cancer tumors have a unique characteristic: they can release tumor cells into the lymphatic system and cause tumors to grow elsewhere in the body, even in tissues or organs totally unrelated to those that were the original source of the tumor. This process is called metastasis, and sometimes forces doctors to use whole-body or systemic anti-cancer treatments when a localized treatment targeting a single tumor would be both more effective and far easier on the patient. Now scientist are advancing understanding of how metastasis occurs, and how to prevent it.
Researchers at Burnham Institute for Medical Research in La Jolla, California recently reported that reactive oxygen species were key players in the cellular process of metastasis. Reactive oxygen species (ROS) include superoxide, hydrogen peroxide and other forms of oxygen generated by the body’s normal functions. Some uses of ROS are beneficial, such as when the immune system generates ROS to kill invading cells. In cancerous cells, however, ROS help form lesions and break down cell walls, aiding in the spread of tumor-forming cells. Researchers have isolated a scaffold protein called Tks5 (for Tyrosine Kinase Substrate) which is concentrated in extruded lesions of tumor cells, called podosomes (or invadopodia in some papers). Tks5-rich cells rapidly produce ROS and form lesions that facilitate the spread of tumorous cells throughout the body. In their paper, Burnham scientists show that cells lacking the gene for Tks5 production are substantially inhibited from forming metastatic tumors, and treating the tumor cells with antioxidants similar suppresses the activity of Tks5, resulting in smaller tumors, fewer lesions/podosomes and a substantial decrease in extruded (metastatic) cells.
An example of tumor size reduction in cells lacking the Tks5 gene (4.20 and 4.24):
This paper is an exciting advance in the understanding of the basic processes of malignant cancer. If podosome formation and metastasis can be reduced by either antioxidant treatments or drugs that target Tks5, huge advances can be made in reducing the mortality associated with highly-metastatic malignant cancer.
For more information:
Reactive Oxygen’s Role in Metastasis
A role for the podosome/invadopodia scaffold protein Tks5 in tumor growth in vivo (Blouw et al)
Metastasis (Wikipedia article)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Tuesday, September 15, 2009
Old Flu Drug, New Hope
A QUANTUM OF SCIENCE
When vaccines fail, antiviral drugs might make the difference between life and death
The seasonal flu vaccine is already being administered and a special vaccine targeting H1N1 will soon follow, but for some people a vaccine may not be enough. Children, the elderly and immunocompromised individuals are at high risk for complications from influenza. For those already infected a vaccine does no good, but fortunately, antiviral medications are available when the flu turns life-threatening.
The most well-known anti-influenza drug is TamiFlu (its official name is Oseltamivir). TamiFlu is taken orally, usually for a five-day course of treatment. Approved in 1999, it has been used to treat 50 million people to date. Currently, TamiFlu is usually reserved for serious, potentially life-threatening cases in an attempt to prevent the flu virus from mutating into a form resistant to the drug. Indeed, five cases of TamiFlu-resistant H1N1 have already been reported but overall the rate of resistance flu cases remains low (around 1.2%).
Recently, a drug called Peramivir has been developed and is on the fast track to approval by the FDA. This is not a new drug – it was abandoned in 2001 by Johnson and Johnson due to low oral availability – but in 2005 concerns over Avian flu caused drug-makers to reexamine the compound and begin testing it as an intravenous medication. Recent studies show a single intravenous dose of Peramivir is as effective as the full five-day course of oral treatment with TamiFlu. Additionally, adverse drug reactions were less common with Peramivir.
Both TamiFlu and Peramivir act by inhibiting the same viral enzyme, neuraminidase. This enzyme allows viral particles to escape infected cells and go out in the bloodstream where they can find new cells to infect. When TamiFlu or Peramivir inhibit the viral neuraminidase, viral particles remain trapped inside infected cells until the body’s immune system can respond, usually with macrophages (literally "big eaters") that engulf the infected cell and digest it, destroying the viral particles along with the cell.
Additional advantages of Peramivir include its single-dose effectiveness. There have been reports of individuals hoarding TamiFlu pills and threatening the supply of the drug, but that cannot happen with a drug which can only be administered intravenously.
For more information:
Study: New Drug Fights Flu as Well as TamiFlu
TamiFlu (Wikipedia article)
TamiFlu-resistant H1N1 cases reported
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
When vaccines fail, antiviral drugs might make the difference between life and death
The seasonal flu vaccine is already being administered and a special vaccine targeting H1N1 will soon follow, but for some people a vaccine may not be enough. Children, the elderly and immunocompromised individuals are at high risk for complications from influenza. For those already infected a vaccine does no good, but fortunately, antiviral medications are available when the flu turns life-threatening.
The most well-known anti-influenza drug is TamiFlu (its official name is Oseltamivir). TamiFlu is taken orally, usually for a five-day course of treatment. Approved in 1999, it has been used to treat 50 million people to date. Currently, TamiFlu is usually reserved for serious, potentially life-threatening cases in an attempt to prevent the flu virus from mutating into a form resistant to the drug. Indeed, five cases of TamiFlu-resistant H1N1 have already been reported but overall the rate of resistance flu cases remains low (around 1.2%).
Recently, a drug called Peramivir has been developed and is on the fast track to approval by the FDA. This is not a new drug – it was abandoned in 2001 by Johnson and Johnson due to low oral availability – but in 2005 concerns over Avian flu caused drug-makers to reexamine the compound and begin testing it as an intravenous medication. Recent studies show a single intravenous dose of Peramivir is as effective as the full five-day course of oral treatment with TamiFlu. Additionally, adverse drug reactions were less common with Peramivir.
Both TamiFlu and Peramivir act by inhibiting the same viral enzyme, neuraminidase. This enzyme allows viral particles to escape infected cells and go out in the bloodstream where they can find new cells to infect. When TamiFlu or Peramivir inhibit the viral neuraminidase, viral particles remain trapped inside infected cells until the body’s immune system can respond, usually with macrophages (literally "big eaters") that engulf the infected cell and digest it, destroying the viral particles along with the cell.
Additional advantages of Peramivir include its single-dose effectiveness. There have been reports of individuals hoarding TamiFlu pills and threatening the supply of the drug, but that cannot happen with a drug which can only be administered intravenously.
For more information:
Study: New Drug Fights Flu as Well as TamiFlu
TamiFlu (Wikipedia article)
TamiFlu-resistant H1N1 cases reported
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Toward Better Vaccines
A QUANTUM OF SCIENCE
Making vaccines both optimally effective and optimally safe may be an easier task in the near future
Vaccines have an overwhelming track record when it comes to preventing illness, and thanks in part to conservative rules put in place by the federal agencies regulating them vaccines have also been extremely safe. Still, there’s an unadvertised trade-off in that compromise: vaccines would be even more effective than they are today if they could be made with heat-inactivated pathogens rather than highly purified microbial proteins generated in non-toxic bacteria, but that elevates the risk of possible immune reactions and side effects in those who take the vaccine.
To help improve the effectiveness of vaccines even when not using the heat-inactivated pathogens, scientists have long used compounds known as adjuvants to "boost" the body’s immune response. In essence, adjuvants are sensitizers that tell the body to be ready for an invader; when given as part of a vaccination, adjuvants significantly increase the vaccine’s protective effects both in duration and potency. But the only adjuvant ever approved for use in humans, aluminum hydroxide (or alum), is far from the most effective compound for the job. To date the FDA has been extremely reluctant to approve other, more powerful adjuvants for use with vaccines because of concerns about toxicity and possible side-effects.
Now scientists at Oregon State University have developed an adjuvant based on lecithin, a common food product, that shows six-fold greater immune response when administered as part of a vaccine as compared to alum-based treatments. Lecithin is part of a category of food products termed "generally recognized as safe" by the FDA, meaning that it is non-toxic in almost any dosage. This could mean a fast track to approval and, very possibly, vaccines that would be more effective, for longer periods of time, with smaller doses and fewer injections.
For more information:
New adjuvant could hold future of vaccine development
Adjuvant (Wikipedia article)
Strong antibody responses induced by protein antigens conjugated onto the surface of lecithin-based nanoparticles (Sloat et al)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Making vaccines both optimally effective and optimally safe may be an easier task in the near future
Vaccines have an overwhelming track record when it comes to preventing illness, and thanks in part to conservative rules put in place by the federal agencies regulating them vaccines have also been extremely safe. Still, there’s an unadvertised trade-off in that compromise: vaccines would be even more effective than they are today if they could be made with heat-inactivated pathogens rather than highly purified microbial proteins generated in non-toxic bacteria, but that elevates the risk of possible immune reactions and side effects in those who take the vaccine.
To help improve the effectiveness of vaccines even when not using the heat-inactivated pathogens, scientists have long used compounds known as adjuvants to "boost" the body’s immune response. In essence, adjuvants are sensitizers that tell the body to be ready for an invader; when given as part of a vaccination, adjuvants significantly increase the vaccine’s protective effects both in duration and potency. But the only adjuvant ever approved for use in humans, aluminum hydroxide (or alum), is far from the most effective compound for the job. To date the FDA has been extremely reluctant to approve other, more powerful adjuvants for use with vaccines because of concerns about toxicity and possible side-effects.
Now scientists at Oregon State University have developed an adjuvant based on lecithin, a common food product, that shows six-fold greater immune response when administered as part of a vaccine as compared to alum-based treatments. Lecithin is part of a category of food products termed "generally recognized as safe" by the FDA, meaning that it is non-toxic in almost any dosage. This could mean a fast track to approval and, very possibly, vaccines that would be more effective, for longer periods of time, with smaller doses and fewer injections.
For more information:
New adjuvant could hold future of vaccine development
Adjuvant (Wikipedia article)
Strong antibody responses induced by protein antigens conjugated onto the surface of lecithin-based nanoparticles (Sloat et al)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Friday, September 11, 2009
A Weed No Longer
A QUANTUM OF SCIENCE
Latex production finds an unlikely source: dandelions
Latex is a complex emulsion of proteins, alkaloids, starches, sugars, oils, tannins, resins, and gums. In most plants, latex is white, but some have yellow, orange, or scarlet latex. Latex rubber comes from rubber trees, mostly found in South America, where industrial production of this common material has been severely impacted by fungal infections that threaten the entire industry.
The alternative? Dandelions.
The milky white juice that comes out of the stem when picked is a latex not unlike that found in rubber trees, except that it polymerizes immediately on contact with air. With some careful genetic work, scientists have developed a strain of dandelions lacking the enzyme that causes that polymerization, leading to the very real promise of industrial dandelion latex farms in the next five years. The best part of all is that latex from dandelions exhibits none of the immune rejection observed in latex rubber products, making it safe for use by hospitals and other important applications.
Dandelions: a weed no longer.
For more information:
Dandelion’s natural latex now used for rubber production
Latex (Wikipedia article)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Latex production finds an unlikely source: dandelions
Latex is a complex emulsion of proteins, alkaloids, starches, sugars, oils, tannins, resins, and gums. In most plants, latex is white, but some have yellow, orange, or scarlet latex. Latex rubber comes from rubber trees, mostly found in South America, where industrial production of this common material has been severely impacted by fungal infections that threaten the entire industry.
The alternative? Dandelions.
The milky white juice that comes out of the stem when picked is a latex not unlike that found in rubber trees, except that it polymerizes immediately on contact with air. With some careful genetic work, scientists have developed a strain of dandelions lacking the enzyme that causes that polymerization, leading to the very real promise of industrial dandelion latex farms in the next five years. The best part of all is that latex from dandelions exhibits none of the immune rejection observed in latex rubber products, making it safe for use by hospitals and other important applications.
Dandelions: a weed no longer.
For more information:
Dandelion’s natural latex now used for rubber production
Latex (Wikipedia article)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
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