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Fatal brain cancer tamed by gene therapy
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AXEL KOESTER/NEW YORK TIMES/EYEVINE
In brief– Words to get hat up about
Global warming and bad air go hand in hand INCREASED air pollution could make global warming an even bigger killer. A new study reveals that air pollution associated with elevated carbon dioxide levels is already responsible for around 22,000 deaths every year. When these are added to casualties from extreme weather events, it doubles the number of fatalities that can be linked to global warming. Mark Jacobson at Stanford University in California modelled the effect of CO2 levels on air pollution and estimated the resulting impact on people’s health. A rise in
CO2 increases the temperature and water vapour content of the atmosphere, which in turn accelerate ozone production and encourage particulates to hang around in the air. “Increased ozone causes respiratory illnesses, while particulate matter causes cardiovascular disease,” he says. Jacobson’s model shows that for every 1 °C rise in temperature in the US, there are 1000 additional air pollution-related deaths (Geophysical Research Letters, DOI: 10.1029/2007GL031101). Globally, he estimates that CO2-related air pollution is causing 21,600 extra deaths per year on average. Global temperatures have risen by 0.8 °C since the industrial revolution, and with CO2 emissions accelerating, the problem will get worse, says Jacobson.
Gene therapy helps rats beat tumour RATS with an aggressive form of human brain cancer have been successfully treated with gene therapy that “trains” the immune system to attack tumours. The results could pave the way for human trials early next year, say researchers who developed the system at the Cedars-Sinai Medical Center in Los Angeles. Previous attempts to treat glioblastomas with gene therapy 16 | NewScientist | 23 February 2008
failed because some tumour cells survived and regrew. The new treatment overcomes this problem by permanently priming the immune system to pick off any straggler tumour cells. A harmless virus that only infects fast-dividing cancer cells is injected directly into the brain, and used to deliver the therapeutic genes into the tumour. One gene, HSV1-TK, kills the cancer cells by
activating ganciclovir, an otherwise ineffective drug administered into the rat’s abdomen. Yet the key to the therapy’s long-term success is a second gene, Flt3L, which summons immune “dendritic” cells from the bloodstream into the brain. These cells engulf the debris and transport it back to lymph nodes, where they re-prime the immune system to attack any remaining tumour cells during and after treatment. The work will appear in Molecular Therapy (DOI: 10.1038/mt.2008.18).
SOME words really do conjure up mental images, and that can drive you to distraction – literally. Zachary Estes at the University of Warwick, UK, and his team asked students to identify a target letter appearing briefly at the top or bottom of a computer screen. Just before the letter appeared, some saw the word “hat” in the centre of the screen. Those students were slower and less accurate at identifying the target letter if it then appeared at the top of the screen (Psychological Science, DOI: 10.1111/j.14679280.2008.02051.x). Estes thinks the brain associates “hat” with the “up” position, and conjures up a mental picture of a hat high on the screen. This distracts you from identifying a letter occupying the same space. “It’s like putting two pictures on top of each other – it’s difficult to see either of them clearly,” he says.
Giant frog leaps into historic fray “THE frog from hell”, a giant fossil discovered in Madagascar, has opened a rift among researchers over when an ancient land bridge closed. The finding supports the controversial view that South America and Madagascar were linked until 80 million years ago – far more recently than has previously been thought. The 40-centimetre-long frog, Beelzebufo, resembles horned toads that are now unique to South America (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0707599105). Team member Susan Evans of University College London says the fossil casts doubt on traditional models which suggest the land connection between South America and Madagascar was lost 120 million years ago. www.newscientist.com
AXEL KOESTER/NEW YORK TIMES/EYEVINE
In brief– Words to get hat up about
Global warming and bad air go hand in hand INCREASED air pollution could make global warming an even bigger killer. A new study reveals that air pollution associated with elevated carbon dioxide levels is already responsible for around 22,000 deaths every year. When these are added to casualties from extreme weather events, it doubles the number of fatalities that can be linked to global warming. Mark Jacobson at Stanford University in California modelled the effect of CO2 levels on air pollution and estimated the resulting impact on people’s health. A rise in
CO2 increases the temperature and water vapour content of the atmosphere, which in turn accelerate ozone production and encourage particulates to hang around in the air. “Increased ozone causes respiratory illnesses, while particulate matter causes cardiovascular disease,” he says. Jacobson’s model shows that for every 1 °C rise in temperature in the US, there are 1000 additional air pollution-related deaths (Geophysical Research Letters, DOI: 10.1029/2007GL031101). Globally, he estimates that CO2-related air pollution is causing 21,600 extra deaths per year on average. Global temperatures have risen by 0.8 °C since the industrial revolution, and with CO2 emissions accelerating, the problem will get worse, says Jacobson.
Gene therapy helps rats beat tumour RATS with an aggressive form of human brain cancer have been successfully treated with gene therapy that “trains” the immune system to attack tumours. The results could pave the way for human trials early next year, say researchers who developed the system at the Cedars-Sinai Medical Center in Los Angeles. Previous attempts to treat glioblastomas with gene therapy 16 | NewScientist | 23 February 2008
failed because some tumour cells survived and regrew. The new treatment overcomes this problem by permanently priming the immune system to pick off any straggler tumour cells. A harmless virus that only infects fast-dividing cancer cells is injected directly into the brain, and used to deliver the therapeutic genes into the tumour. One gene, HSV1-TK, kills the cancer cells by
activating ganciclovir, an otherwise ineffective drug administered into the rat’s abdomen. Yet the key to the therapy’s long-term success is a second gene, Flt3L, which summons immune “dendritic” cells from the bloodstream into the brain. These cells engulf the debris and transport it back to lymph nodes, where they re-prime the immune system to attack any remaining tumour cells during and after treatment. The work will appear in Molecular Therapy (DOI: 10.1038/mt.2008.18).
SOME words really do conjure up mental images, and that can drive you to distraction – literally. Zachary Estes at the University of Warwick, UK, and his team asked students to identify a target letter appearing briefly at the top or bottom of a computer screen. Just before the letter appeared, some saw the word “hat” in the centre of the screen. Those students were slower and less accurate at identifying the target letter if it then appeared at the top of the screen (Psychological Science, DOI: 10.1111/j.14679280.2008.02051.x). Estes thinks the brain associates “hat” with the “up” position, and conjures up a mental picture of a hat high on the screen. This distracts you from identifying a letter occupying the same space. “It’s like putting two pictures on top of each other – it’s difficult to see either of them clearly,” he says.
Giant frog leaps into historic fray “THE frog from hell”, a giant fossil discovered in Madagascar, has opened a rift among researchers over when an ancient land bridge closed. The finding supports the controversial view that South America and Madagascar were linked until 80 million years ago – far more recently than has previously been thought. The 40-centimetre-long frog, Beelzebufo, resembles horned toads that are now unique to South America (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0707599105). Team member Susan Evans of University College London says the fossil casts doubt on traditional models which suggest the land connection between South America and Madagascar was lost 120 million years ago. www.newscientist.com