The ability of native Tibetans to tolerate high altitude is, of course, legendary. Tibetans living on the Tibetan plateau at elevations that exceed 4000 meters are exposed to an atmosphere that has oxygen concentrations that are approximately 40% lower than that which is available at sea level. From a biological perspective it is of interest to know how this has been achieved.
From the evidence accumulated by Jian Wang and his associates from the University of California at Berkeley, Tibetans have acquired a number of inherited adaptations to this extreme environment, including – higher birth weight, higher hemoglobin – the protein found in red blood cells that binds oxygen - levels, higher oxygen saturation in the blood of infants and adults following exercise when compared with a control group of Han Chinese who moved to Tibet and are genetically distinct. Tibetans have occupied the Tibetan Plateau for over 25,000 years, possibly enough time to accumulate genetic adaptations through natural selection.
In an attempt to delineate the genetic characteristics of these adaptations, the investigators analyzed the DNA from both Tibetans and the control group. There results demonstrated, in fact, a single-nucleotide polymorphism (SNP) – a single point variation in the DNA studied – from a gene that encodes for the EPAS1 protein. This protein has been shown to be involved in the body’s response to hypoxia – low oxygen environment. This change occurred at a much higher frequency in native Tibetans than in the control group of Han Chinese.
These results represent a very important finding in regards to the fact that this beneficial genetic modification occurred over a very brief interval of time as compared to previously studied human genetic adaptations.
Tuesday, August 17, 2010
Saturday, August 7, 2010
An Argument for a Dramatic Improvement in the Science Education of Our Children
The technological wonders of the modern age are quite spectacular. One of the most profound of these is the Hubble telescope. Many human lives are saved and horrific diseases are averted daily due to the great strides made in the arena of health and medicine. The additional examples that could be cited are too numerous to mention here. Technological improvements are a direct outcome of the application of scientific enquiry and discovery.
The human world is beset with many problems that demand solution – the most urgent of these being climate change. There is a growing body of scientific evidence that supports this contention, including:
•Record setting high temperatures during the last ten years
•Erratic, severe and unusual weather conditions
•Increase in the frequency and severity of forest fires
•Increased acidity in the world’s oceans that has impacted the health of coral, phytoplankton and shelled creatures especially oyster larvae
•Melting and receding of glaciers worldwide
•Melting of the ice in the Arctic Ocean during the summer months.
The science that has established the relationship between the increased concentration of carbon dioxide and methane, the so-called greenhouse gases, resulting from human activity is clear and irrefutable.
In spite of these data, there is a marked resistance in this country to accept not only the obvious implication of these observations, but the meaningfulness of the observations themselves. This, to me, is extremely disturbing, for inaction or lack of sufficient resolve to confront this issue will inevitably result in disastrous consequences for future generations.
This inability to grasp the urgency of the issues that confront us is a direct result of the failure to educate our children in the realm of science. Science has some essential characteristics that make it exceedingly well suited for problem solving. It is cooperative effort; scientific advances are a direct result of strides made by investigators in the past as well as the present. Science depends on a growing body of knowledge; it builds upon all that has been already discovered. In addition, the scientific process is open-minded; any hypothesis or law must fit the data that is accumulated through observation. If new data does not fit the interpretation then the conclusions need to be modified to accommodate the newly acquired facts. Science requires a rigorous thought process that relies on higher-order functions in the human brain.
In my judgment, it is not possible to meet the challenges we face in this technologically-driven world without a sufficiently adequate education in the sciences. We have failed abysmally in this regard in the United States. Ignorance is not bliss by any stretch of the imagination. Ignorance will inevitably lead to erroneous conclusions and ultimate disaster.
The human world is beset with many problems that demand solution – the most urgent of these being climate change. There is a growing body of scientific evidence that supports this contention, including:
•Record setting high temperatures during the last ten years
•Erratic, severe and unusual weather conditions
•Increase in the frequency and severity of forest fires
•Increased acidity in the world’s oceans that has impacted the health of coral, phytoplankton and shelled creatures especially oyster larvae
•Melting and receding of glaciers worldwide
•Melting of the ice in the Arctic Ocean during the summer months.
The science that has established the relationship between the increased concentration of carbon dioxide and methane, the so-called greenhouse gases, resulting from human activity is clear and irrefutable.
In spite of these data, there is a marked resistance in this country to accept not only the obvious implication of these observations, but the meaningfulness of the observations themselves. This, to me, is extremely disturbing, for inaction or lack of sufficient resolve to confront this issue will inevitably result in disastrous consequences for future generations.
This inability to grasp the urgency of the issues that confront us is a direct result of the failure to educate our children in the realm of science. Science has some essential characteristics that make it exceedingly well suited for problem solving. It is cooperative effort; scientific advances are a direct result of strides made by investigators in the past as well as the present. Science depends on a growing body of knowledge; it builds upon all that has been already discovered. In addition, the scientific process is open-minded; any hypothesis or law must fit the data that is accumulated through observation. If new data does not fit the interpretation then the conclusions need to be modified to accommodate the newly acquired facts. Science requires a rigorous thought process that relies on higher-order functions in the human brain.
In my judgment, it is not possible to meet the challenges we face in this technologically-driven world without a sufficiently adequate education in the sciences. We have failed abysmally in this regard in the United States. Ignorance is not bliss by any stretch of the imagination. Ignorance will inevitably lead to erroneous conclusions and ultimate disaster.
Wednesday, August 4, 2010
Dangers of Increased Acidity in the World’s Oceans as a Direct Result of Human Activity
The effect of increased carbon dioxide resulting from human activity on the oceans is quite clear. There is a direct relationship between increasing levels of carbon dioxide in the atmosphere and the increasing acidification of the oceans. The chemistry has been well documented. Carbon dioxide (CO2) when dissolved in water (H2O) forms carbonic acid (H2CO3). This acidification has been implicated in the destruction of coral. Recent evidence has also demonstrated that increased acidity in the oceans also has a deleterious impact on oyster larvae as well.
As I have reported earlier, it has been shown that increased acidity in the oceans has placed increased stress on phytoplankton, an organism that is a fundamental part of the food web in the world’s oceans. They account for one-half of all oxygen production as a result of photosynthesis on the planet.
In this article we will review the impact increased acidity is having on the world’s oceans in greater detail. Currently, human societies are collectively depositing gigatons of carbon dioxide per year into the earth’s atmosphere - a gigaton is equivalent to one billion tons. According to Lee Kump, a geochemist at Pennsylvania State University, this kind of growth in the level of carbon dioxide emissions as a direct result of human activity on the earth may be considered, “as one of the most notable, if not cataclysmic events in the history of the planet.”
It is estimated that there has been a drop of 0.1 pH unit in the global ocean since the beginnings of the industrial revolution with a .026 drop within the last fifteen years. These are disturbing data. Computer modeling predicts that if this trend continues the pH will have dropped to 7.8 from the 8.2 value in the pre-industrial age, where pH is a logarithmic measure of the concentration of hydrogen ions – a solution having a pH below 7.0 is considered to be acidic. By way of comparison, the pH of the stomach is around 2.0.
According to Richard A. Kerr in an article published in the June 18 2010 Science, decreasing pH impacts species that build shells or skeletons of calcium carbonate in the following way, “These organisms include tropical corals, echinoderms, mollusks, microscopic foraminifera floating in surface waters and certain algae. When the hydrogen ion concentration of seawater gets high enough, the calcium carbonate in these organisms begins to dissolve.”
The oceans provide much of the world’s supply of food. These data taken together with the warming effect on the earth’s oceans as a result of increased carbon dioxide in the earth’s atmosphere and its resulting effect on weather patterns, paints an alarming picture in regards to the changing natural environment and the future of humanity.
As I have reported earlier, it has been shown that increased acidity in the oceans has placed increased stress on phytoplankton, an organism that is a fundamental part of the food web in the world’s oceans. They account for one-half of all oxygen production as a result of photosynthesis on the planet.
In this article we will review the impact increased acidity is having on the world’s oceans in greater detail. Currently, human societies are collectively depositing gigatons of carbon dioxide per year into the earth’s atmosphere - a gigaton is equivalent to one billion tons. According to Lee Kump, a geochemist at Pennsylvania State University, this kind of growth in the level of carbon dioxide emissions as a direct result of human activity on the earth may be considered, “as one of the most notable, if not cataclysmic events in the history of the planet.”
It is estimated that there has been a drop of 0.1 pH unit in the global ocean since the beginnings of the industrial revolution with a .026 drop within the last fifteen years. These are disturbing data. Computer modeling predicts that if this trend continues the pH will have dropped to 7.8 from the 8.2 value in the pre-industrial age, where pH is a logarithmic measure of the concentration of hydrogen ions – a solution having a pH below 7.0 is considered to be acidic. By way of comparison, the pH of the stomach is around 2.0.
According to Richard A. Kerr in an article published in the June 18 2010 Science, decreasing pH impacts species that build shells or skeletons of calcium carbonate in the following way, “These organisms include tropical corals, echinoderms, mollusks, microscopic foraminifera floating in surface waters and certain algae. When the hydrogen ion concentration of seawater gets high enough, the calcium carbonate in these organisms begins to dissolve.”
The oceans provide much of the world’s supply of food. These data taken together with the warming effect on the earth’s oceans as a result of increased carbon dioxide in the earth’s atmosphere and its resulting effect on weather patterns, paints an alarming picture in regards to the changing natural environment and the future of humanity.
Tuesday, July 20, 2010
The Fight Against Malaria – Some Encouraging News
Malaria continues to be a scourge in many parts of the world. The problem is particularly acute in Africa. Malaria is a pervasive illness characterized by high fevers, shaking chills, flu-like symptoms, and anemia. It is caused by a parasite referred to as Plasmodium falciparum (the Asian variety is Plasmodium vivax and not as virulent). Plasmodium is carried by the Anopheles mosquito prevalent in the tropics.
The plasmodium parasite exhibits a number of stages in its life cycle. The disease progresses in the following way. Once an individual is infected, sporozoites migrate to the liver where they develop into merozoites. From there they enter the bloodstream and attack red blood cells. Within 48 to 72 hours the infected red blood cells breakdown releasing more parasites into the bloodstream.
Chloroquine is a commonly used drug against Malaria. However some strains of the anopheles mosquito have developed an immunity to this drug. In this case, quinidine or quinine plus doxycycline, tetracycline, or clindamycin; or atovaquone plus proguanil (Malarone); or mefloquine or artesunate; or the combination of pyrimethamine and sulfadoxine, are given instead.
Malaria is so pervasive that it is estimated that 300 to 500 million individuals contract the disease each year resulting in approximately 1 million deaths. This is a wholly unacceptable situation from a world health perspective.
In spite of this daunting reality, significant inroads have been made, especially in the area of prevention. Thanks in part to the mass infusion of resources from the Bill and Melinda Gates Foundation, insecticide-treated bed nets, indoor spraying of insecticides and a category of powerful drugs called artemisinin-based combination therapies (ACTs) have shown remarkably positive results in pilot studies. In addition, although many attempts at making a completely effective vaccine have failed, a vaccine that seems to be 50% effective in offering protection for the first 8 months is now under development. These efforts, taken together, offer significant hope that the spread of this horrific disease may be curtailed in not eventually eliminated.
The plasmodium parasite exhibits a number of stages in its life cycle. The disease progresses in the following way. Once an individual is infected, sporozoites migrate to the liver where they develop into merozoites. From there they enter the bloodstream and attack red blood cells. Within 48 to 72 hours the infected red blood cells breakdown releasing more parasites into the bloodstream.
Chloroquine is a commonly used drug against Malaria. However some strains of the anopheles mosquito have developed an immunity to this drug. In this case, quinidine or quinine plus doxycycline, tetracycline, or clindamycin; or atovaquone plus proguanil (Malarone); or mefloquine or artesunate; or the combination of pyrimethamine and sulfadoxine, are given instead.
Malaria is so pervasive that it is estimated that 300 to 500 million individuals contract the disease each year resulting in approximately 1 million deaths. This is a wholly unacceptable situation from a world health perspective.
In spite of this daunting reality, significant inroads have been made, especially in the area of prevention. Thanks in part to the mass infusion of resources from the Bill and Melinda Gates Foundation, insecticide-treated bed nets, indoor spraying of insecticides and a category of powerful drugs called artemisinin-based combination therapies (ACTs) have shown remarkably positive results in pilot studies. In addition, although many attempts at making a completely effective vaccine have failed, a vaccine that seems to be 50% effective in offering protection for the first 8 months is now under development. These efforts, taken together, offer significant hope that the spread of this horrific disease may be curtailed in not eventually eliminated.
Wednesday, July 7, 2010
Impact of Climate Change on Phytoplankton
There is an unambiguous relationship between increasing levels of carbon dioxide in the atmosphere as a direct result of human activity and the increasing acidification of the oceans. This results from a well known chemical principle that carbonic dioxide (CO2) when dissolved in water (H2O) forms carbonic acid (H2CO3). This acidification has been implicated in the destruction of coral.
In a recent report in the journal Science, Doctor D. Shi from the Department of Geosciences at Princeton University has established a correlation between increasing acidity in the oceans and increased stress on phytoplankton. Phytoplankton is a fundamental part of the food web in the world’s oceans and, therefore, plays a key role in the life of the oceans. In addition they account for one-half of all oxygen production as a result of photosynthesis on the planet.
Doctor Shi and his colleagues have shown that acidification of the ocean places stress on phytoplankton populations by impacting the bioavailability of Iron. Iron plays a pivotal role in the metabolism of these organisms. This particular consequence of the ever increasing level of atmospheric carbon dioxide is certainly a cause for concern.
In a recent report in the journal Science, Doctor D. Shi from the Department of Geosciences at Princeton University has established a correlation between increasing acidity in the oceans and increased stress on phytoplankton. Phytoplankton is a fundamental part of the food web in the world’s oceans and, therefore, plays a key role in the life of the oceans. In addition they account for one-half of all oxygen production as a result of photosynthesis on the planet.
Doctor Shi and his colleagues have shown that acidification of the ocean places stress on phytoplankton populations by impacting the bioavailability of Iron. Iron plays a pivotal role in the metabolism of these organisms. This particular consequence of the ever increasing level of atmospheric carbon dioxide is certainly a cause for concern.
Tuesday, June 29, 2010
New Frontiers in the Treatment of Alzheimer’s
Alzheimer’s is a devastating disease of the human brain that ordinarily displays symptoms in old age. It is an ailment that is characterized by progressive dementia that totally incapacitates the patient and ultimately ends in death.
Alzheimer’s is characterized by a gradual build up of protein fragments referred to as amyloid-beta peptides. These fragments accumulate in the intercellular spaces within the brain. The disease process ultimately leads to profound cell death. Anti-amyloid drugs and a vaccine have been developed to combat this disease. These novel therapies have so far been disappointing.
As a result of extensive research into the disease process, there is now a new understanding of disease progression. The buildup of the amyloid-beta peptides begins from 5-20 years before diagnosis. In addition a protein called, TAU that normally functions to maintain the infrastructure within nerve cells (neurons) is modified leading to disruption of normal cell function. This seems to occur 1-5 years prior to the appearance of symptoms, and finally, brain shrinkage becomes noticeable as a result of significant cell death 1-3 years before diagnosis.
On account of these findings, the current understanding is that the failure of new therapies to effect a beneficial change may be due to the fact that when treatments are initiated the brain damage is already too advanced to yield beneficial results.
In the town of Medellin, Columbia there are approximately 5000 members of 25 extended families who develop early-onset Alzheimer’s. This is a result of dominant gene that is found in less than one percent of 27 million Alzheimer’s cases worldwide (2006). Individuals of these families, therefore, allow an ideal setting to test this hypothesis. The planned trial is referred to as the Alzheimer’s Prevention Initiative (API). The overall approach is to have appropriate candidates – apparently healthy with the deleterious gene – who are around the age of forty treated with the anti-myeloid therapies as previously discussed.
If this approach yields promising results, - the treatments delay or stop the inexorable progression of the disease - this would be exciting news, especially since the U.S. population is aging.
Alzheimer’s is characterized by a gradual build up of protein fragments referred to as amyloid-beta peptides. These fragments accumulate in the intercellular spaces within the brain. The disease process ultimately leads to profound cell death. Anti-amyloid drugs and a vaccine have been developed to combat this disease. These novel therapies have so far been disappointing.
As a result of extensive research into the disease process, there is now a new understanding of disease progression. The buildup of the amyloid-beta peptides begins from 5-20 years before diagnosis. In addition a protein called, TAU that normally functions to maintain the infrastructure within nerve cells (neurons) is modified leading to disruption of normal cell function. This seems to occur 1-5 years prior to the appearance of symptoms, and finally, brain shrinkage becomes noticeable as a result of significant cell death 1-3 years before diagnosis.
On account of these findings, the current understanding is that the failure of new therapies to effect a beneficial change may be due to the fact that when treatments are initiated the brain damage is already too advanced to yield beneficial results.
In the town of Medellin, Columbia there are approximately 5000 members of 25 extended families who develop early-onset Alzheimer’s. This is a result of dominant gene that is found in less than one percent of 27 million Alzheimer’s cases worldwide (2006). Individuals of these families, therefore, allow an ideal setting to test this hypothesis. The planned trial is referred to as the Alzheimer’s Prevention Initiative (API). The overall approach is to have appropriate candidates – apparently healthy with the deleterious gene – who are around the age of forty treated with the anti-myeloid therapies as previously discussed.
If this approach yields promising results, - the treatments delay or stop the inexorable progression of the disease - this would be exciting news, especially since the U.S. population is aging.
Wednesday, June 16, 2010
Regarding Platelets
Platelets are cell-like bodies that represent an essential component of circulating blood. The role of platelets in blood clotting has long been understood. Since platelets, like red blood cells do not have nuclei and the DNA that is essential for life, it was assumed that blood-clotting was the only role for platelets.
In recent years, platelets have been shown to possess diverse functions. They have been found to release growth factors and other factors that help in the repair of damaged tissues. In addition, they help initiate the inflammatory response, alert immune cells and they have even been implicated in the attack of invading microbes in the midst of a bacterial infection. They also function as carriers, delivering serotonin to the liver which aids in the regeneration of the liver following a traumatic injury. Platelets also participate in the development of the circulatory system in newborns.
It is interesting to note that Doctor Weyrich and his colleagues from the Human Biology and Genetics Program at the University of Utah have demonstrated that platelets reproduce in spite of the fact that they lack a cell nucleus. They send out a strand with one or more bead-like bulges that eventually separate producing new platelets.
This new understanding of how platelets function will ultimately open the door to new kinds of therapies and treatment for diseases in which they are apparently implicated.
In recent years, platelets have been shown to possess diverse functions. They have been found to release growth factors and other factors that help in the repair of damaged tissues. In addition, they help initiate the inflammatory response, alert immune cells and they have even been implicated in the attack of invading microbes in the midst of a bacterial infection. They also function as carriers, delivering serotonin to the liver which aids in the regeneration of the liver following a traumatic injury. Platelets also participate in the development of the circulatory system in newborns.
It is interesting to note that Doctor Weyrich and his colleagues from the Human Biology and Genetics Program at the University of Utah have demonstrated that platelets reproduce in spite of the fact that they lack a cell nucleus. They send out a strand with one or more bead-like bulges that eventually separate producing new platelets.
This new understanding of how platelets function will ultimately open the door to new kinds of therapies and treatment for diseases in which they are apparently implicated.
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