Environmental issues effect every life on this planet from the smallest parasite to the human race. The reason for this is simple. A single disruption in the Earth?s delicate balance can mean certain destruction of the very place that cradles the lives of many species. What is not so simple is finding alternatives to the now dangerous and confronting acts of planet degradation that have been afflicted on the planet over recent years. One such issue that requires consideration is deforestation. Trees have been or are being cut down at increasingly high rates. If this is not stopped many unfavorable side effects could result.
Why Trees Matter
To understand why deforestation is such a pressing and urgent issue, forests must first be given credit for what they bring to global ecosystems and the quality of life that all species maintain. Tropical Rainforests presently give a place to call home for 50% - 90% of all organisms, 90% of our relatives, the primates, and 50 million creatures that can live no place but the rich rainforests (World Rainforest Movement 16). Not only are other species at risk, but the human race also benefits from what the trees give. From something as minor as the spices that indulge food to life giving medicines, the rainforests amplify and save lives. According to the World Rainforest Movement, 25% of medicines come from the forests (28). This is a number that does not do justice to all the cures that have yet to be discovered or that have been destroyed. The forests give life, not only to other species, but they help to prolong the human race. The forests have global implications not just on life but on the quality of it. Trees improve the quality of the air that species breath by trapping carbon and other particles produced by pollution. Trees determine rainfall and replenish the atmosphere. As more water gets put back in the atmosphere, clouds form and provide another way to block out the sun?s heat. Trees are what cool and regulates the earth?s climate in conjunction with other such valuable services as preventing erosion, landslides, and making the most infertile soil rich with life. Mother earth has given much responsibility to trees.
Population Growth an Deforestation
So this leads into a very confusing question of the 20th century. Why are these trees being torn down? The World Wide Forest Report found that when the Roman Empire was in control of Europe 90% of the continent was forested. Today 500,000 hectors vanish in a single week ("Logging is the Major Cause of Global Deforestation" 1). There is no one easy answer as there are many causes at the root of deforestation. One is overpopulation in cities and developing countries. Population is continually growing in the third world. Some had land until increases in population forced them off it and they became landless peasants that are forced to look for land in the untouched forests. This movement to the forests is in some ways a result of government pressures. In place of implementing programs to help the poor these governments concentrate on the cheapest, easiest, way to keep poverty out of sight and give the poor no other choice but to force other species out and themselves in. According to Norman Myers, bad land tenure, a shortage of modern agricultural tools, and government neglect of subsistence farmers have put an influx of human interference in the forests. (37) The poor are pushed in further and further and destroy more every time they must move on.
What the poor do in the forests is the most devastating. In attempts to settle farmland, the poor become "shifted cultivators" and resort to using slash and burn methods of tree removal. Slashing and burning involves what its name implies, trees are cut down and the remains are burned. The ash is used as a fertilizer and the land is then used for farming or cattle grazing, however, the soil that is cleared in slash and burn is left infertile, the nutrients in the soil are quickly absorbed by surrounding organisms ("Deforestation" 1). The farmers must move on sometimes to other areas and repeat this process and worthy land and trees become scarce. For farmers in places like Brazil, slash and burn methods are the only way to effectively clear land of parasites and unwanted organisms; chemical means contaminate water and soil and farmers continue to turn to slashing and burning ("Slash and Burn Agriculture" 1). It has become so much a dilemma that a leading researcher, Myers, sees it of all the causes of deforestation, to be the number one cause (Myers 32).
Logging and Deforestation
The small farmer plays a big role, but it is modern industry that too cuts down the trees. The logging industry is fueled by the need for disposable products. 11 million acres a year are cut for commercial and property industries (Entity Mission 1). Peter Heller found that McDonald?s needs 800 square miles of trees to make the amount of paper they need for a year?s supply of packaging, Entity Mission found that British Columbia manufactures 7, 500,000 pairs of chopsticks a day, and the demand for fuel wood is so high that predictions say that there will be a shortage by the year 2000. Logging does too have its repercussions. The logging industry not only tries to accomplish all this but it even indirectly helps the "shifted cultivators" and others to do more damage. The roads that the loggers build to access the forests and generate hydroelectric power create an easy way for many people to try to manipulate the forest resources. The amount of damage that this adds to the forests can not be measured nor can that of the illegal logging. Some importers may even be buying illegally logged wood and not even have known it ("Logging is the Major Cause of Global Deforestation ? New WWF Report" 2).
Cattle Grazing and Deforestation
Another of the more devastating forces behind deforestation is cattle grazing. With the international growth of fast food chains this seems to be an evident factor in the clearing of trees today. Large corporations looking to buy beef for hamburger and even pet food seek cheap prices and are finding them with the growth of cattle grazing (Heller 3). In the Amazon region of South America alone there are 100,000 beef ranchers (Heller 3). As the burger giants of industrialized society are making high demands for more beef, more forests are being torn down. Statistics from less than a decade ago, 1989, indicate that 15,000 km squared of forests are used expressly for the purpose of cattle grazing (Myers 32). Once the trees are gone the land is often overgrazed. In some places the government wants this to happen. Cattle grazing is big profit that can?t be turned down.
Other Causes
Beyond the major causes of deforestation lie some supplementary ones that too stack the odds against forests around the globe. Acid rain and the building of dams have their share of harmful effects. The race to produce cash crops such as fruit, spices, sugar tobacco, soap, rubber, paper, and cloth has given cause to many to try to farm them by using soil and other products that can be retrieved by destroying the forests. Even those in industrialized countries may participate in the destruction of forests in the 3rd world. The need for products in industrialized countries drives production in other poorer, less developed countries. This production is at the cost of the trees and the services that they provide.
The Effects
Deforestation presents multiple societal and environmental problems. The immediate and long-term consequences of global deforestation are almost certain to jeopardize life on Earth, as we know it. Some of these consequences include: loss of biodiversity; the destruction of forest-based-societies; and climatic disruption.
What is Lost
Deforestation is causing a loss of biological diversity on an unprecedented scale. Although tropical forests cover only six percent of Earth?s land surface, they happen to contain between 70% and 90% of all of the world?s species (Myers, 12). As a result of deforestation, we are losing between 50 and 100 animal and plant species each day (Myers 12). Inevitably, the loss of species entails a loss of genetic resources. Many of these species now facing the possibility of extinction are of enormous potential to humans in many areas; especially medicine. As of 1991, over 25% of the world?s pharmaceutical products were derived from tropical plants (Myers). By contributing to the extinction of multiple species of plants and animals, we might be destroying the cures for many of the diseases that plague the human race today.
The world?s forests, particularly tropical rainforests, are home to over 10 million members of the "last surviving intimately resource-based cultures" (GFF 3). Given the importance of forest products to the daily lives of forest peoples, the destruction of tropical forests entails the destruction of tribal populations as a whole. Aboriginal people world-wide have had their land literally stolen from them by governments and industries, whose intent is to turn "natural capital into hard currency" (Dudley 11). As the Global Futures Foundation states, "there have been more extinctions of tribal peoples in this century than any other?Even in the rare cases when forest dwellers are compensated for this loss, the changes visited upon their cultures by the inexorable expansion of industrial culture are devastating." Without a doubt, deforestation has had a profound effect on cultural diversity throughout the forest regions, and ultimately, the world.
Erosion
The lushness of the world?s tropical forests is somewhat deceptive. Although these forests assume to be lush and full, the underlying soils are very poor, almost all the nutrients being bound up in the vegetation. The problem is that once forests have been cut down, essential nutrients are washed out of the soil all-together. This leads to soil erosion. As of now, about 80% of the soils in the humid tropics are acidic and infertile (Dudley 21). When there are no trees to keep the soil in place, the soil becomes ripe for erosion. It dries and cracks under the sun?s heat. Once the soil temperature exceeds 25 degrees centigrade, volatile nutrient ingredients like nitrogen can be lost, further reducing the fertility of the remaining soil (Myers 14). Furthermore, rainfall washes remaining nutrients into rivers. This means that replanting trees will not necessarily help to solve the problems of deforestation; by the time the trees have matured, the soil might be completely stripped of essential nutrients. Eventually, cultivation in the forest regions will be impossible, and the land will be useless. The soil erosion will lead to permanent impoverishment of huge land areas.
The social impact of soil erosion can be quite severe. Those who settle into the forest regions are forced to move every year or so due to soil erosion. They find areas where they can cultivate. When those areas are no longer good for growing, they move to another region.
Flooding
Flooding is a quite serious consequence of deforestation. Clearing the forest dramatically increases the surface run-off from rainfall, mainly because a greater proportion of the rain reaches the ground due to a lack of vegetation which would suck up the excess rainfall. "Tropical forests can receive as much rain in an hour as London would expect in a wet month, and a single storm has been measured as removing 185 tonnes of topsoil per hectare" (Dudley 21). In tropical regions where the forests are dense, flooding is not as serious a problem because there is vegetation to absorb the rainfall. It is in areas where there is little vegetation that there is a problem. Hence, to avoid the disastrous effects of flooding, tropical forests need to remain dense and lush.
Climate Change
Although all consequences of deforestation are potentially serious, perhaps the most serious consequence is that of climate change due to the loss of trees. Earth has an atmosphere which contains a variety of gases, all in a delicate balance, to ensure life on Earth. One of these gases in Earth?s atmosphere is carbon dioxide; a gas which helps moderate heat loss to outer space. Insulating gases such as carbon dioxide are called "greenhouse gasses because their function is much like that of the glass in a greenhouse: they allow solar heat into the system, but discourage its escape" (GFF 3). Other greenhouse gases include methane, chlorofluorocarbons, nitrous oxide, and ozone. If there are additional greenhouse gases, there will be a gradual increase in temperature on Earth?s surface. This could lead to changes in weather patterns, sea levels, and other cycles in nature that directly affect life on Earth (GFF 3). The process of greenhouse gas increase is quite simple. Carbon dioxide levels increase for a number of reasons; but one of the main factors contributing to the increase of carbon levels is decay of woody material. The only way to help moderate the levels of carbon dioxide in the atmosphere is through plant life. Alive plants and trees absorb the carbon dioxide from decaying plants and trees. With a decrease in trees and plant life (due to deforestation) it is much harder to moderate these levels. Ultimately, the amount of carbon will increase due to a lack of plant life present to keep the carbon dioxide levels in check. This whole process leads to an "albedo effect which reflects more heat and light back into the atmosphere than would be the case if the sun shone on green trees?" (Dudley 23). The bottom line is that the increase in the carbon level and other greenhouse gas levels into the atmosphere leads to an increase in temperature, and eventually a change in climate
Discussion
We as human beings may not understand the severity of the possible consequences that deforestation poses. Since deforestation has had no severe effect on us yet, we ignore the problem. Everywhere you go, you see pieces of paper on the ground, people using multiple tissues to wipe their noses, and countless people pulling excessive amounts of brown paper out of the paper towel dispensers in lavatories. These are just few of the sources of paper that we use each day, without any thought whatsoever.
What we must realize is that the paper products we use daily could have been a part of a forest which functioned to enrich and hold soil, absorb carbon dioxide, collect and recycle water, release oxygen, and regulate climate. Some companies do plant trees to produce the kinds of the products needed by industry to spare the older forests but many do not. By wasting paper products, we are wasting forests. The simple fact is that the more paper we use, the more forests need to be cut down to serve our paper needs.
Many people might not consider the possible consequences of deforestation serious. They might say, "What if: a few people lose their homes; we experience a little flooding here and there; the temperature rises a little bit; we miss out on a few new medicines; we kill off a few species which we never knew existed in the first place; the soil loses its nutrients." Ignorant people like these do not realize the severity of these consequences.
By destroying people?s homes, we are cheating ourselves out of having a more diverse world. Flooding will cause billions upon billions of dollars in repairs; and those repairs will most likely be done by the good old U.S., with our tax dollars. If the temperature rises a bit, this will throw mother nature totally off course. It will affect farming, the tourism industry, travel, sea levels, and much more. If what Myers found is correct and 25% of medicines come form the rain forests, then there is a big change that with modern technologies that many more could be found. Without knowing what is being destroyed, we might not be missing out on just a few new medicines. We might be killing our chances of finding the cures for diseases such as Cancer, Aids, Multiple Sclerosis, or a multitude of others. And if by chance we lose all of the nutrients in the soil because of soil erosion, cultivation will be next to impossible. After thinking about these consequences, try convincing anyone that the ramifications of deforestation will not prove to be quite disastrous.
Forests were put on Earth for a reason; they help to maintain a delicate balance between all of nature?s elements. By destroying forests through ranching, logging, farming, industrial practice, etc., we are putting this delicate balance in jeopardy.
There is no cure for deforestation. Sure, many people talk of reforestation; however that is just not a true solution. Although replanting the forests that have been destroyed seems like a good idea, it actually does no good. Often times the new trees are not the same species as the originals. Also, by the time the trees grow and mature, the soil has already lost much of the nutrients it once had. Old forests and new forests are not the same and it is the old forest that need to be protected.
The only way to ensure that we will not encounter any of the consequences of deforestation is to stop destroying the forests all together. We would have to stop cutting down all trees, no matter what our needs were. Since this is totally impractical as of now, the only thing we can do is use forest products in moderation. However this idea of moderation needs to be put into practice immediately. We as people should take care of this problem before it gets to the point where we can no longer fix it. Instead of putting the problem on the back burner until we can no longer ignore it, how about we remedy it now so it never threatens us to begin with. The sad fact is that once the forests are gone, we won?t be able to fix the damage which we have caused.
Conclusion
So where can we go from here? There is no one easy solution as deforestation is caused by many things. One option is decreasing the need for the amount of products that are harvested from the rainforests. If all countries, especially developed ones, enforced programs that used recycling, the need for disposable products would be diminished and the loggers would not have a business. If the demand is cut off, there is no need for the supply. Other solutions involve money. One that could help to alleviate deforestation is providing aide to foreign countries so they give homes to those who are at high risk of becoming "shifted cultivators". The trick is convincing tax payers to reach into their pockets. Another would be to appeal to the American public to settle for higher prices on the cash crops that are imported to this country for cheap prices especially that burger at the local fast food joint. If Americans are willing to pay more, corperations such as those in the fast food industry can stop petitioning other countries to farm the rainforests for the manufacture of the materials they need to make their products.
The immediate effects of deforestation may not yet be felt, but if this generation doesn?t feel it the next generation and their children will be the ones to suffer. It is the actions of the human race that can make or break the future of the planet. In the end everyone loses unless a solution can be reached. This is easier said than done but the choices that lie ahead on this matter carry severe consequences that will forever change they way that all things live if they are able to live at all.
Terms to Know
Aboriginal People ? People who were the original inhabitants of the land. Atmosphere ? The outer layer of gases that surround a planet. Biodiversity ? The variation in life forms that exists on the planet. Developing/3rd World Nations ? Countries that do not have the economic resources that other, more economically powerful nations possess. Ecosystems ? Collection of life forms, the way they live and interact with each other. Erosion ? Land that becomes barren of nutrients and the soil literally "erodes" and is swept away by the elements. Evapotranspiration ? Water is removed from the environment by transpiration and evaporation, transpiration being the taking in of water by leaves on trees. Global Warming ? The temperature increase in the earth?s climate that is caused by an increased number of gases such as methane, carbon dioxide, and nitrous oxide that retain heat in the earth?s atmosphere. Greenhouse Gasses ? Gasses that trap heat and hold it in the Earth?s atmosphere, helping to contribute to global warming. Industrialized Countries ? Powerful countries that have economic and technological resources that other countries do not have. Shifted Cultivators ? People forced off their land who resort to making homes and farms in the tropical forests.
Jocelyn Stock Andy Rochen
Saturday, June 20, 2009
Deforestation causes global warming
Most people assume that global warming is caused by burning oil and gas. But in fact between 25 and 30 percent of the greenhouse gases released into the atmosphere each year – 1.6 billion tonnes – is caused by deforestation. About 200 experts, mostly from developing countries, met in Rome last week to address this issue in a workshop organized by the United Nations Framework Convention on Climate Change (UNFCCC) and hosted by FAO. “We are working to solve two of the key environmental issues – deforestation and global warming – at the same time,” said FAO Senior Forestry Officer Dieter Schoene.Trees are 50 percent carbon. When they are felled or burned, the C02 they store escapes back into the air. According to FAO figures, some 13 million ha of forests worldwide are lost every year, almost entirely in the tropics. Deforestation remains high in Africa, Latin America and Southeast Asia.Readiness to actDelegates of the 46 developing countries present at the Rome workshop signalled their readiness to act on deforestation, 80 percent of which is due to increased farmland to feed growing populations. Part of the solution is to increase agricultural productivity so that there is less demand to convert forests into farmland.But they also stressed that they needed financial help from the developed world to do the job. A major flow of capital from north to south – under new instruments still waiting to be negotiated -- would be required to help the developing nations conserve their forests. Such incentives could come in the form of carbon credits as further action under the Kyoto Protocol, which governs greenhouse gas emissions from industrial sources in developed countries. It could also come directly under the Climate Change Framework Convention, or from bilateral agreements between donors and developing countries on country-wide forest conservation projects. Such questions are subject of ongoing international negotiations, which will continue later this year in Nairobi.The Rome workshop was supported by FAO and the Governments of Italy, Australia, Finland, the Netherlands and New Zealand.
Industry examines waste water management
The Textile Processors Association today held a training programme on ‘Wastewater Management in Textile Dyeing, Printing and Finishing industry’ today.
Speaking on the occasion, Krishan Kumar Sharma, president, Textile Processors Association said, “Being small in size, it is difficult for the industry to address environment issues. This problem is challenging and overburdening individual units. ” The aim of the programme, he said, is to train textile manufacturers about how they can control water consumption at source.
Dr Akepati S Reddy of Thapar Technology Campus noted that the industry is both water and energy intensive. He added that the options before the textile manufacturers are reduction of water consumption at source, re-cycling of water, re-use and treatment of polluted water and disposal. “Waste water management advocates a ‘cradle to grave’ approach, for ensuring cost effective and consistent compliance with the environmental requirements,” he added
Speaking on the occasion, Krishan Kumar Sharma, president, Textile Processors Association said, “Being small in size, it is difficult for the industry to address environment issues. This problem is challenging and overburdening individual units. ” The aim of the programme, he said, is to train textile manufacturers about how they can control water consumption at source.
Dr Akepati S Reddy of Thapar Technology Campus noted that the industry is both water and energy intensive. He added that the options before the textile manufacturers are reduction of water consumption at source, re-cycling of water, re-use and treatment of polluted water and disposal. “Waste water management advocates a ‘cradle to grave’ approach, for ensuring cost effective and consistent compliance with the environmental requirements,” he added
Friday, June 19, 2009
'Weedy' Bird Species May Win As Temperatures Rise
Climate change is altering North American winter bird communities in ways that models currently favored by ecologists fail to predict.
Based on patterns of animals found in different climate zones today, ecologists would expect that as habitats warm, numbers of species found there will increase, and that those species will be smaller in size and restricted to narrower geographic ranges. Ecologists at the University of California, San Diego have found that only one of those three predictions has held for North American birds over the past quarter century.
Instead, their analysis has revealed that warmer weather has favored "weedy" species, those that are adapted to a wide range of habitats and therefore easily extend their ranges. Larger birds, which are typically better disperses than smaller species, seem to have gained an advantage, they report in the early online edition of the Proceedings of the Royal Society B June 10.
"The changes, at least initially, are likely to favor generalist species, those in the best position to respond to changes," said Frank La Sorte, a post-doctoral fellow at UC San Diego and first author of the paper. "It's going to be difficult using existing spatial ecological patterns to predict the outcome of climate change."
The team based their assessment on the annual Christmas Bird Count, an event organized by the National Audubon Society in which volunteers note which birds are present within a 24 kilometer wide circle in their communities over a 24-hour period in early winter, relying on either sight or sound to identify the species.
The team found 404 sites throughout North America where birders surveyed every year between 1975 and 2001. Over that period of time, the average annual temperature of these communities increased by nearly one degree Celsius.
As spatial models predict, the numbers of species counted at each site grew as temperature climbed. But that increase could be attributed to larger and more widespread species becoming more common, a pattern not reflected by differences between ecological communities found in warmer versus cooler parts of the world.
The observation suggests that weedy species may win in a warmer world, at least initially. But it also warns ecologists that they may need to revise their models when planning conservation in the face of global climate change.
"Biodiversity is under severe threat from climate change, and the lack of long-term data makes accurate forecasting of likely impact notoriously difficult," said Walter Jetz, associate professor of biology at UC San Diego and senior author of the paper. "Our study illustrates the limitations of using spatial relationships that were established over millennia to model the ecological consequences of current climate change, which is proceeding at a very rapid rate. Rigorous assessment will require much more extensive, long-term monitoring of ecological communities."
Based on patterns of animals found in different climate zones today, ecologists would expect that as habitats warm, numbers of species found there will increase, and that those species will be smaller in size and restricted to narrower geographic ranges. Ecologists at the University of California, San Diego have found that only one of those three predictions has held for North American birds over the past quarter century.
Instead, their analysis has revealed that warmer weather has favored "weedy" species, those that are adapted to a wide range of habitats and therefore easily extend their ranges. Larger birds, which are typically better disperses than smaller species, seem to have gained an advantage, they report in the early online edition of the Proceedings of the Royal Society B June 10.
"The changes, at least initially, are likely to favor generalist species, those in the best position to respond to changes," said Frank La Sorte, a post-doctoral fellow at UC San Diego and first author of the paper. "It's going to be difficult using existing spatial ecological patterns to predict the outcome of climate change."
The team based their assessment on the annual Christmas Bird Count, an event organized by the National Audubon Society in which volunteers note which birds are present within a 24 kilometer wide circle in their communities over a 24-hour period in early winter, relying on either sight or sound to identify the species.
The team found 404 sites throughout North America where birders surveyed every year between 1975 and 2001. Over that period of time, the average annual temperature of these communities increased by nearly one degree Celsius.
As spatial models predict, the numbers of species counted at each site grew as temperature climbed. But that increase could be attributed to larger and more widespread species becoming more common, a pattern not reflected by differences between ecological communities found in warmer versus cooler parts of the world.
The observation suggests that weedy species may win in a warmer world, at least initially. But it also warns ecologists that they may need to revise their models when planning conservation in the face of global climate change.
"Biodiversity is under severe threat from climate change, and the lack of long-term data makes accurate forecasting of likely impact notoriously difficult," said Walter Jetz, associate professor of biology at UC San Diego and senior author of the paper. "Our study illustrates the limitations of using spatial relationships that were established over millennia to model the ecological consequences of current climate change, which is proceeding at a very rapid rate. Rigorous assessment will require much more extensive, long-term monitoring of ecological communities."
Key Found To How Tumor Cells Invade The Brain In Childhood Cancer
Despite great strides in treating childhood leukemia, a form of the disease called T-cell acute lymphoblastic leukemia (T-ALL) poses special challenges because of the high risk of leukemic cells invading the brain and spinal cord of children who relapse.
Now, a new study in the June 18, 2009, issue of the journal Nature by scientists at NYU School of Medicine reveals the molecular agents behind this devastating infiltration of the central nervous system. The finding may lead to new drugs that block these agents and thus lower the risk of relapse.
T-ALL, a blood-borne cancer in which the bone marrow makes too many lymphocytes, or white blood cells, strikes several hundred children and adolescents in the U.S. annually. While greater than 90% percent go into remission through a combination of chemotherapy and radiation, up to one third of this group end up relapsing. These patients are at particular risk for tumor cells to invade the brain and spinal cord, and to prevent this all patients receive chemotherapy injections into the central nervous system and in some cases cranial irradiation—approaches that cause dangerous side effects, including secondary tumors and potentially permanent cognitive and developmental deficits.
“In general, T-cell acute lymphoblastic leukemia is treatable with chemotherapy and radiation,” said Ioannis Aifantis, PhD, associate professor of pathology and co-director of the Cancer Stem Cell Program at the NYU Cancer Institute, who led the new study. “But you have a very high rate of relapse. And after the relapse, it is not treatable because the cancer occurs in tricky places like the central nervous system,” said Dr. Aifantis, who is also an Early Career Scientist at the Howard Hughes Medical Institute.
“We are very proud of this research and very excited about the potential implications for new therapeutic approaches to prevent or reduce the spread of leukemic cells into the central nervous system,” said Vivian S. Lee MD, PhD, MBA, the vice dean for science, senior vice president and chief scientific officer of NYU Langone Medical Center.
In the new study, Dr. Aifantis and his colleagues found that a key protein receptor embedded on the outer surface of leukemic cells is responsible for infiltrating the brain and spinal cord. “What we have found is that leukemic cells over-express this receptor.” said Dr. Aifantis, “If you knock out this receptor, these cells will not go to the brain under any circumstances.”
Previous research had strongly implicated a famous gene regulator called Notch1 in the progression of T-ALL. The Notch1 gene (a mutated version gives fruit flies notched wings) is an oncogene, or cancer-causing gene, in humans. Certain kinds of mutations in this gene have been found in nearly half of all T-ALL patients, and current estimates suggest that the gene’s regulatory influence might be implicated in nearly 90 percent of all T-ALL cases.
For their new study, Dr. Aifantis and his colleagues first introduced overactive forms of Notch1 into mice. As a result, the mice developed leukemia and the leukemic cells efficiently infiltrated the inner layers of the membrane covering the brain. “What happens is that the leukemic cells get into the cerebrospinal fluidthat protects our brain and spine, where they fill up the space and they can affect brain function, either by secreting chemicals and toxic factors or even by simple pressure,” Dr. Aifantis said.
His team then examined an array of other mouse genes to identify candidates that might fall under the regulatory spell of Notch1 to promote the brain and spinal cord infiltration. The screen revealed a promising gene for a protein named CCR7, which is embedded on the surface of lymphocytes. This chemokine receptor, as it’s known, normally senses and responds to small chemical attractants called chemokines, which act like recruitment signals for lymphocytes to converge on a specific site during the body’s response to infection or injury. In leukemia, however, these lymphocytes proliferate abnormally.
CCR7 was already known as a key player in normal lymphocyte migration and as a binding partner of two chemokines named CCL19 and CCL21. Previous studies had implicated these protein interactions in the metastasis of other tumors such as melanomas and breast cancers. Dr. Aifantis’s team also discovered that the gene for CCR7 was overactive in four of five T-ALL cell lines derived from human patients, bolstering suspicions that it played a central role in the disease. Conversely, a mutation that knocked out Notch1 also led to dramatically reduced CCR7 levels.
To characterize CCR7’s potential role in T-ALL, the researchers used two sets of mice: one in which the receptor was turned on, and a second in which it was turned off. When the team delivered an identical number of human-derived leukemic cells to both sets of mice, those with the CCR7 chemokine receptor turned off lived almost twice as long. Using bioluminescent imaging, the researchers quickly understood why: animals with the active CCR7 receptor had many more tumors. Tellingly, the T-ALL cells had infiltrated the brain and spinal cord of those mice.
Further experiments suggested that when healthy mice received leukemic cells in which the gene for CCR7 had been turned off, the cells could not migrate to the brain even though they reached other body tissues. As a result, the mice survived significantly longer than counterparts with an active copy of the gene. On the other hand, introducing a normal version of the same gene to mice otherwise lacking it was enough to recruit leukemic cells to the brain and spine.
“We wanted to determine whether CCR7 by itself was sufficient for entry into the central nervous system and that’s what this experiment shows,” Dr. Aifantis said. “By changing one specific gene, you now have your function back.”
Finally, the researchers identified the small protein that acted as the “come hither” signal for the CCR7 protein receptors. One candidate, CCL21, was undetectable in leukemic mice. But a second, CCL19, appeared in tiny veins of the brain near the infiltrating tumor cells. When the researchers introduced leukemic cells carrying a gene for CCR7 to mice that naturally lacked the CCL19 chemokine, the mice survived longer, suggesting that their increased life spans might be due to a disrupted interaction of the two proteins. The leukemic cells had no trouble infiltrating other tissue like the lymph nodes, but were completely incapable of infiltrating the brains of CCL19-deficient mice, the researchers report.
“Perhaps there are antibodies or small molecules that can block the interaction between these two proteins or reduce their interactions,” Dr. Aifantis said, “and hopefully that could be used as a type of prophylactic treatment to prevent a relapse in the central nervous system among patients who have already been treated for leukemia.” Such a treatment, he said, could prove a good alternative to the intensive and often poorly tolerated radiation and chemotherapy now used to try to block such a relapse.
The study was led by Dr. Silvia Buonamici, a post-doctoral fellow in the laboratory of Dr. Aifantis in the Department of Pathology and the NYU Cancer Institute, and in the Helen L. and Martin S. Kimmel Stem Cell Center at NYU Langone Medical Center. Other study investigators are; Thomas Trimarchi, Maria Grazia Ruocco, Linsey Reavie, Severine Cathelin, Yevgeniy Lukyanov, Jen-Chieh Tseng, Filiz Sen, Mengling Li, Elizabeth Newcomb, Jiri Zavadil, Daniel Meruelo, Sherif Ibrahim, David Zagzag, and Michael L. Dustin from NYU Langone Medical Center; Brenton G. Mar, Apostolos Klinakis, and Argiris Efstratiadis from Columbia University Medical Center; Eric Gehrie and Jonathan S. Bromberg from Mount Sinai School of Medicine; and Martin Lipp from the Max Delbrück Center for Molecular Medicine in Berlin.
The study was supported by grants from the National Institutes of Health, the American Cancer Society, the Dana Foundation, The Chemotherapy Foundation, the Alex’s Lemonade Stand Foundation, the Lauri Strauss Leukemia foundation, the G&P Foundation, an NYU School of Medicine Molecular Oncology and Immunology training grant, the American Society of Hematology, the Juvenile Diabetes Research Foundation, the National Cancer Institute, a gift from the Berrie Foundation, and a fellowship from the Jane Coffin Childs Memorial Fund for Medical Research.
Now, a new study in the June 18, 2009, issue of the journal Nature by scientists at NYU School of Medicine reveals the molecular agents behind this devastating infiltration of the central nervous system. The finding may lead to new drugs that block these agents and thus lower the risk of relapse.
T-ALL, a blood-borne cancer in which the bone marrow makes too many lymphocytes, or white blood cells, strikes several hundred children and adolescents in the U.S. annually. While greater than 90% percent go into remission through a combination of chemotherapy and radiation, up to one third of this group end up relapsing. These patients are at particular risk for tumor cells to invade the brain and spinal cord, and to prevent this all patients receive chemotherapy injections into the central nervous system and in some cases cranial irradiation—approaches that cause dangerous side effects, including secondary tumors and potentially permanent cognitive and developmental deficits.
“In general, T-cell acute lymphoblastic leukemia is treatable with chemotherapy and radiation,” said Ioannis Aifantis, PhD, associate professor of pathology and co-director of the Cancer Stem Cell Program at the NYU Cancer Institute, who led the new study. “But you have a very high rate of relapse. And after the relapse, it is not treatable because the cancer occurs in tricky places like the central nervous system,” said Dr. Aifantis, who is also an Early Career Scientist at the Howard Hughes Medical Institute.
“We are very proud of this research and very excited about the potential implications for new therapeutic approaches to prevent or reduce the spread of leukemic cells into the central nervous system,” said Vivian S. Lee MD, PhD, MBA, the vice dean for science, senior vice president and chief scientific officer of NYU Langone Medical Center.
In the new study, Dr. Aifantis and his colleagues found that a key protein receptor embedded on the outer surface of leukemic cells is responsible for infiltrating the brain and spinal cord. “What we have found is that leukemic cells over-express this receptor.” said Dr. Aifantis, “If you knock out this receptor, these cells will not go to the brain under any circumstances.”
Previous research had strongly implicated a famous gene regulator called Notch1 in the progression of T-ALL. The Notch1 gene (a mutated version gives fruit flies notched wings) is an oncogene, or cancer-causing gene, in humans. Certain kinds of mutations in this gene have been found in nearly half of all T-ALL patients, and current estimates suggest that the gene’s regulatory influence might be implicated in nearly 90 percent of all T-ALL cases.
For their new study, Dr. Aifantis and his colleagues first introduced overactive forms of Notch1 into mice. As a result, the mice developed leukemia and the leukemic cells efficiently infiltrated the inner layers of the membrane covering the brain. “What happens is that the leukemic cells get into the cerebrospinal fluidthat protects our brain and spine, where they fill up the space and they can affect brain function, either by secreting chemicals and toxic factors or even by simple pressure,” Dr. Aifantis said.
His team then examined an array of other mouse genes to identify candidates that might fall under the regulatory spell of Notch1 to promote the brain and spinal cord infiltration. The screen revealed a promising gene for a protein named CCR7, which is embedded on the surface of lymphocytes. This chemokine receptor, as it’s known, normally senses and responds to small chemical attractants called chemokines, which act like recruitment signals for lymphocytes to converge on a specific site during the body’s response to infection or injury. In leukemia, however, these lymphocytes proliferate abnormally.
CCR7 was already known as a key player in normal lymphocyte migration and as a binding partner of two chemokines named CCL19 and CCL21. Previous studies had implicated these protein interactions in the metastasis of other tumors such as melanomas and breast cancers. Dr. Aifantis’s team also discovered that the gene for CCR7 was overactive in four of five T-ALL cell lines derived from human patients, bolstering suspicions that it played a central role in the disease. Conversely, a mutation that knocked out Notch1 also led to dramatically reduced CCR7 levels.
To characterize CCR7’s potential role in T-ALL, the researchers used two sets of mice: one in which the receptor was turned on, and a second in which it was turned off. When the team delivered an identical number of human-derived leukemic cells to both sets of mice, those with the CCR7 chemokine receptor turned off lived almost twice as long. Using bioluminescent imaging, the researchers quickly understood why: animals with the active CCR7 receptor had many more tumors. Tellingly, the T-ALL cells had infiltrated the brain and spinal cord of those mice.
Further experiments suggested that when healthy mice received leukemic cells in which the gene for CCR7 had been turned off, the cells could not migrate to the brain even though they reached other body tissues. As a result, the mice survived significantly longer than counterparts with an active copy of the gene. On the other hand, introducing a normal version of the same gene to mice otherwise lacking it was enough to recruit leukemic cells to the brain and spine.
“We wanted to determine whether CCR7 by itself was sufficient for entry into the central nervous system and that’s what this experiment shows,” Dr. Aifantis said. “By changing one specific gene, you now have your function back.”
Finally, the researchers identified the small protein that acted as the “come hither” signal for the CCR7 protein receptors. One candidate, CCL21, was undetectable in leukemic mice. But a second, CCL19, appeared in tiny veins of the brain near the infiltrating tumor cells. When the researchers introduced leukemic cells carrying a gene for CCR7 to mice that naturally lacked the CCL19 chemokine, the mice survived longer, suggesting that their increased life spans might be due to a disrupted interaction of the two proteins. The leukemic cells had no trouble infiltrating other tissue like the lymph nodes, but were completely incapable of infiltrating the brains of CCL19-deficient mice, the researchers report.
“Perhaps there are antibodies or small molecules that can block the interaction between these two proteins or reduce their interactions,” Dr. Aifantis said, “and hopefully that could be used as a type of prophylactic treatment to prevent a relapse in the central nervous system among patients who have already been treated for leukemia.” Such a treatment, he said, could prove a good alternative to the intensive and often poorly tolerated radiation and chemotherapy now used to try to block such a relapse.
The study was led by Dr. Silvia Buonamici, a post-doctoral fellow in the laboratory of Dr. Aifantis in the Department of Pathology and the NYU Cancer Institute, and in the Helen L. and Martin S. Kimmel Stem Cell Center at NYU Langone Medical Center. Other study investigators are; Thomas Trimarchi, Maria Grazia Ruocco, Linsey Reavie, Severine Cathelin, Yevgeniy Lukyanov, Jen-Chieh Tseng, Filiz Sen, Mengling Li, Elizabeth Newcomb, Jiri Zavadil, Daniel Meruelo, Sherif Ibrahim, David Zagzag, and Michael L. Dustin from NYU Langone Medical Center; Brenton G. Mar, Apostolos Klinakis, and Argiris Efstratiadis from Columbia University Medical Center; Eric Gehrie and Jonathan S. Bromberg from Mount Sinai School of Medicine; and Martin Lipp from the Max Delbrück Center for Molecular Medicine in Berlin.
The study was supported by grants from the National Institutes of Health, the American Cancer Society, the Dana Foundation, The Chemotherapy Foundation, the Alex’s Lemonade Stand Foundation, the Lauri Strauss Leukemia foundation, the G&P Foundation, an NYU School of Medicine Molecular Oncology and Immunology training grant, the American Society of Hematology, the Juvenile Diabetes Research Foundation, the National Cancer Institute, a gift from the Berrie Foundation, and a fellowship from the Jane Coffin Childs Memorial Fund for Medical Research.
Diesel engines clean up their act
Some good news for a change.
A new study shows that 2007 diesel engines are belching out 90% less pollution than 2004 models when it comes to many toxic emissions. Some say the improvements will save lives.
The report by the Coordinating Research Council, a nonprofit research group, found that emissions of fine particulate matter, a dangerous pollutant that can get into people's lungs, has decreased by 99%. That's 89% lower than 2007 EPA standards.
Smog-producing hydrocarbons and carbon monoxide emissions also passed EPA standards with flying colors, dropping more than 90%, according to the study. Nitrogen oxides, another culprit in smog production, went down 70%, or 10% below required levels.
The improvements will save lives.
EPA's standards apply only to new diesel engines. California remains the only state to force truckers to clean up existing diesel engines, through controversial rules adopted in December 2009.
A new study shows that 2007 diesel engines are belching out 90% less pollution than 2004 models when it comes to many toxic emissions. Some say the improvements will save lives.
The report by the Coordinating Research Council, a nonprofit research group, found that emissions of fine particulate matter, a dangerous pollutant that can get into people's lungs, has decreased by 99%. That's 89% lower than 2007 EPA standards.
Smog-producing hydrocarbons and carbon monoxide emissions also passed EPA standards with flying colors, dropping more than 90%, according to the study. Nitrogen oxides, another culprit in smog production, went down 70%, or 10% below required levels.
The improvements will save lives.
EPA's standards apply only to new diesel engines. California remains the only state to force truckers to clean up existing diesel engines, through controversial rules adopted in December 2009.
EPA targets cement industry emissions
Environmentalists and industry representatives pleaded their case with federal regulators Tuesday over rules that would slash toxic emissions from cement kilns, the top source of mercury emissions in California.The Environmental Protection Agency issued proposed regulations for Portland cement kilns earlier this year, after more than a decade of pressure from environmental groups. The rules aim to reduce the industry's mercury emissions by an estimated 81% to 93% annually, as well as cut emissions of hydrocarbons, particulate matter and hydrochloric acid.The EPA projects that the changes could save billions of dollars and hundreds of lives a year, but cement industry officials say they will drive up the price of cement, and possibly drive the industry to countries that have lower pollution standards. The rules would "undermine the stability of the domestic cement industry, endangering thousands of jobs and the supply of a basic construction material for uncertain environmental benefits," Andy O'Hare, a spokesman for the Portland Cement Assn., told EPA officials at the hearing in downtown Los Angeles."This regulation will help all Californians breathe easier, particularly the dozens of California communities neighboring cement kilns," Otana Jakpor, a Riverside high school student speaking for the American Lung Assn., told the EPA panel. "It will reduce hundreds of thousands of tons of toxic chemicals that harm young people. And it will do so with technology that already exists. . . . As a young person who lives in an area with some of the worst air pollution in the country, I feel especially passionate about this."
Portland cement kilns, which produce the key ingredient in concrete, account for 90% of the state's airborne mercury, which can affect the nervous system, cognitive function and kidneys, and can cause respiratory failure and death at high exposures, according to the EPA. Cement kilns emit hazardous chemicals as they burn coal, petroleum coke or industrial waste to heat raw materials including limestone ore, which also can contain mercury and other elements. The process produces "clinker," which is cooled, ground and mixed with gypsum. In 2008, high levels of the toxic carcinogen hexavalent chromium were traced to piles of clinker outside the TXI Riverside cement plant, which has since shut down. "We think of California as not having coal-fired power plants, but we really do," said Miriam Rotkin-Ellman, a scientist with the Natural Resources Defense Council. "We have these cement kilns that basically operate as small coal-fired power plants, and some of them aren't so small."California is the nation's largest producer of cement, and houses 11 of the nation's 163 Portland cement plants, including the Lehigh Southwest plant in Tehachapi, which has historically been one of the industry's worst mercury polluters.The EPA is accepting public comments on the proposed rules through Sept. 4. A second hearing will take place in Dallas today and a third in Washington on Thursday
Portland cement kilns, which produce the key ingredient in concrete, account for 90% of the state's airborne mercury, which can affect the nervous system, cognitive function and kidneys, and can cause respiratory failure and death at high exposures, according to the EPA. Cement kilns emit hazardous chemicals as they burn coal, petroleum coke or industrial waste to heat raw materials including limestone ore, which also can contain mercury and other elements. The process produces "clinker," which is cooled, ground and mixed with gypsum. In 2008, high levels of the toxic carcinogen hexavalent chromium were traced to piles of clinker outside the TXI Riverside cement plant, which has since shut down. "We think of California as not having coal-fired power plants, but we really do," said Miriam Rotkin-Ellman, a scientist with the Natural Resources Defense Council. "We have these cement kilns that basically operate as small coal-fired power plants, and some of them aren't so small."California is the nation's largest producer of cement, and houses 11 of the nation's 163 Portland cement plants, including the Lehigh Southwest plant in Tehachapi, which has historically been one of the industry's worst mercury polluters.The EPA is accepting public comments on the proposed rules through Sept. 4. A second hearing will take place in Dallas today and a third in Washington on Thursday
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