Using essentially the same techniques that resulted in the first cloned adult animal (Dolly the sheep), scientists at Oregon Health Sciences University have cloned human cells and coaxed them into developing into human embryos. Their intent was to be able to produce cloned cell lines from the embryos strictly for therapeutic purposes. The research is published online in the journal Cell. The researchers started with eight human eggs from a single human donor, and after enucleating the eggs, joined them with human skin cells. From these they obtained five blastocysts (early-stage embryos) and ultimately produced four cloned cell lines.
So far, human embryos produced by these techniques (known as somatic cell nuclear transfer) have not been allowed to develop into full-term human babies. The cloning of humans, of course, raises some serious ethical issues. Society will have to grapple with the issue soon, because it’s now clearly within the realm of possibility.
The basic idea behind reproductive cloning research is to be able to produce human tissues that are an exact match for the human patient from which the cloned cell was taken. Tissues produced these techniques could be used to produce skin for treating burns, or perhaps heart, or liver cells to repair a damaged organ, without fear of tissue rejection.
Do the potential medical benefits outweigh the ethical concerns associated with the creation and ultimately the sacrifice of human embryos? You decide.
Monday, May 20, 2013
Sunday, May 19, 2013
The NTSB Recommends Lower Blood Alcohol Limits
The National Traffic Safety Board (NTSB) is urging all states to lower the blood alcohol concentration that constitutes drunk driving, to 0.05%. Currently, the limit is 0.08% in all 50 states. The NTSB estimates that lowering the limit to 0.05% would save nearly 1,000 lives per year.
The NTSB estimates that even at 0.05% blood alcohol there is some impairment of depth perception and other visual abilities, resulting in a 39% increase in the chances of an accident while driving. At the current level of 0.08%, the chance of an accident is increased by 100%. Most countries in Europe and also Australia already have a 0.05% limit.
However the NTSB can only recommend the change; it has no legal authority to force states to adopt new laws. The last time a reduction in blood alcohol was recommended (from 0.10 to 0.08%), it took 21 years before the last state made the change. Nevertheless, most states do pay attention to the NTSB’s recommendation and to public opinion. We can expect many states to set new limits at 0.05% by their next legislative session.
Do you know how many drinks you would probably have to consume to surpass the current 0.08% limit? It’s worth knowing if you ever drink and then drive.
Thursday, May 16, 2013
Products Containing DMAA are Still Available
General Nutrition Centers (GNC) is still selling dietary supplement products containing dimethylamylamine (DMAA), a full month after the FDA issued a health warning about the drug. DMAA is an amphetamine-like stimulant found in the workout-boosting product Jack3d.
The FDA says there have been over 80 reports of adverse health effects associated with DMAA, and urges consumers to stop using it. In addition, the FDA argues that DMAA does not qualify as a dietary supplement according to the accepted definition of a dietary supplement. The FDA has already convinced the product’s manufacturers to stop making these products. But the retailer GNC says it does not believe that DMAA is unsafe, and so it continues to sell its stock of workout products containing DMAA.
Whether DMAA qualifies as a dietary supplement may have to be decided in court, if GNC continues to push the issue. Even so, it’s unusual for a company to refuse to take a product off its shelves when it’s labeled unsafe by the FDA. Most companies would err on the side of caution by removing of the product from store shelves immediately. A company that continues to sell a product considered dangerous by the FDA would be risking future lawsuits. Indeed, there’s already one lawsuit against GNC for a death allegedly related to Jack3D.
What is GMC’s logic in continuing to sell Jack3d?!
The FDA says there have been over 80 reports of adverse health effects associated with DMAA, and urges consumers to stop using it. In addition, the FDA argues that DMAA does not qualify as a dietary supplement according to the accepted definition of a dietary supplement. The FDA has already convinced the product’s manufacturers to stop making these products. But the retailer GNC says it does not believe that DMAA is unsafe, and so it continues to sell its stock of workout products containing DMAA.
Whether DMAA qualifies as a dietary supplement may have to be decided in court, if GNC continues to push the issue. Even so, it’s unusual for a company to refuse to take a product off its shelves when it’s labeled unsafe by the FDA. Most companies would err on the side of caution by removing of the product from store shelves immediately. A company that continues to sell a product considered dangerous by the FDA would be risking future lawsuits. Indeed, there’s already one lawsuit against GNC for a death allegedly related to Jack3D.
What is GMC’s logic in continuing to sell Jack3d?!
Tuesday, May 14, 2013
Atmospheric CO2 Levels Reach a Milestone
According to the National Oceanographic and Atmospheric Administration (NOAA), atmospheric CO2 levels rose to a weekly average concentration (rounded to whole numbers) of 400 parts per million (ppm) last week. The actual weekly average for May 5th was 399.52 ppm.
Atmospheric CO2 measurements have been taken every hour of every day at the top of Mauna Loa in Hawaii since the 1950s. The accumulated data show quite convincingly that CO2 levels have risen rapidly over the past 60 years and are now higher (compared to historical averages estimated by other, indirect methods) than the levels at any time over the past three million years.
It is widely believed that the rising CO2 levels of modern times are a direct result of human activities, including especially the burning of fossil fuels (coal, oil, and gas). 400 ppm is just a number, of course; it does not necessarily signify an important level in and of itself. It’s just another signpost on the road of continuously rising CO2 concentrations. Despite all the talk over the past decade or so about the need to stop it to prevent global warming, little action has been taken so far.
So CO2 levels will probably continue to rise for awhile, until we actually get serious about doing something about it.
Atmospheric CO2 measurements have been taken every hour of every day at the top of Mauna Loa in Hawaii since the 1950s. The accumulated data show quite convincingly that CO2 levels have risen rapidly over the past 60 years and are now higher (compared to historical averages estimated by other, indirect methods) than the levels at any time over the past three million years.
It is widely believed that the rising CO2 levels of modern times are a direct result of human activities, including especially the burning of fossil fuels (coal, oil, and gas). 400 ppm is just a number, of course; it does not necessarily signify an important level in and of itself. It’s just another signpost on the road of continuously rising CO2 concentrations. Despite all the talk over the past decade or so about the need to stop it to prevent global warming, little action has been taken so far.
So CO2 levels will probably continue to rise for awhile, until we actually get serious about doing something about it.
Sunday, May 5, 2013
Morning-After Pill Ruling is Appealed
As expected, the Justice Department has appealed the ruling last month by a U.S. District Court judge that the morning-after pill should be made available to girls under the age of 17. Predictably, social conservatives and anti-abortionists are supporting the appeal.
President Obama himself is “comfortable” (now) with the pill being made available to girls as young as 15, according to an NBC news article. But he seemed to be against it back in 2011 (see this blog, Dec. 11, 2011). Perhaps his apparent change of heart was influenced by the fact that he is no longer facing an election?
The available scientific evidence supports making the morning-after pill available to all ages. The pill has proven to be safe enough that were it not a contraceptive pill, it would have been approved for younger girls long ago.
Like it or not, availability of the morning-after pill remains a political issue, not a scientific one.
President Obama himself is “comfortable” (now) with the pill being made available to girls as young as 15, according to an NBC news article. But he seemed to be against it back in 2011 (see this blog, Dec. 11, 2011). Perhaps his apparent change of heart was influenced by the fact that he is no longer facing an election?
The available scientific evidence supports making the morning-after pill available to all ages. The pill has proven to be safe enough that were it not a contraceptive pill, it would have been approved for younger girls long ago.
Like it or not, availability of the morning-after pill remains a political issue, not a scientific one.
Saturday, April 27, 2013
Autism and antidepressants
What are the reasons for the more than six-fold increase in reported cases of autism in the past 20 years? Changes in diagnostic criteria are thought to account for up to 25% of the increased number of cases. Increased awareness of the condition may also mean that more autistic children are being diagnosed as having the condition; some of these children that might have been missed in the past. And there is some evidence that parents of advanced age are more likely to have an autistic child, accounting for some of the cases. Finally, some parents continue to believe (against an overwhelming body of scientific literature) that autism may be caused by something related to childhood vaccinations, and so they refuse to have their children vaccinated. It’s as if lacking an adequate explanation, they’d rather clutch at straws rather than admit that we just don’t know yet.
Two recent studies suggest that some cases of autism may (and I stress may) be related to the mother’s use of certain antidepressant medications during pregnancy. The most recent study is out of Sweden, where national health statistics make large population studies feasible.
The results should be interpreted with caution, however. It will prove difficult to separate out whether it’s the mother’s clinical depression itself, or the drugs used to treat it, that may be increasing the risk of autism. After all, women generally don’t take antidepressants unless they’re clinically depressed. It will be some time before we have a definitive answer, if ever. In the meantime, women who are clinically depressed should discuss the risks and benefits of antidepressant drugs with their physician if they anticipate becoming pregnant.
One final note: the use of antidepressants can’t account for much of the overall rise of autism, because so few pregnant women actually need and use antidepressants. The Swedish study points out that although any woman who uses antidepressants during pregnancy may be doubling the risk of autism in her child, the use of antidepressants during pregnancy probably accounts for less than 1% of all cases of autism in the whole population.
Two recent studies suggest that some cases of autism may (and I stress may) be related to the mother’s use of certain antidepressant medications during pregnancy. The most recent study is out of Sweden, where national health statistics make large population studies feasible.
The results should be interpreted with caution, however. It will prove difficult to separate out whether it’s the mother’s clinical depression itself, or the drugs used to treat it, that may be increasing the risk of autism. After all, women generally don’t take antidepressants unless they’re clinically depressed. It will be some time before we have a definitive answer, if ever. In the meantime, women who are clinically depressed should discuss the risks and benefits of antidepressant drugs with their physician if they anticipate becoming pregnant.
One final note: the use of antidepressants can’t account for much of the overall rise of autism, because so few pregnant women actually need and use antidepressants. The Swedish study points out that although any woman who uses antidepressants during pregnancy may be doubling the risk of autism in her child, the use of antidepressants during pregnancy probably accounts for less than 1% of all cases of autism in the whole population.
Monday, April 22, 2013
FDA Blocks Generic Oxycontin
When a drug’s original patent expires, the FDA usually approves generic versions of the drug. There are winners and losers when this happens. Patients win because generics cost less than the patented drug. Generic drug manufacturers win too. The only loser is the original patent-holder, whose profits usually fall dramatically when a blockbuster drug’s patent expires. But don’t feel too bad for them; they’ve made plenty of profit from the drug already. The high profit they make while the drug is under patent protection (up to 20 years) is supposed to compensate them for the high costs of drug development and testing, which the generic drug companies don’t need to do.
That’s how it usually works. But this week the Food and Drug Administration (FDA) refused to approve a generic version of the popular pain-killing drug OxyContin, on the very day that the drug’s patent was set to expire. Why? OxyContin (a narcotic) has become an abused prescription drug, in part because the pills could be crushed and then injected or snorted, releasing high levels of narcotic all at once. The FDA feared that widespread availability of generic OxyContin would lead to even more abuse of the drug. So in an unusual move, the FDA chose instead to approve a newly-patented, reformulated version of OxyContin that is harder to abuse. When crushed, the new OxyContin becomes a jelly-like mass that can’t be injected or snorted. The potential safety benefits of the newer version were so compelling that the FDA was willing to phase out the old version.
But don't expect the old version of OxyContin to disappear just yet. It turns out that generic OxyContin has been approved for sale in Canada. Canadian pharmacies are likely to have it for sale within a month.
That’s how it usually works. But this week the Food and Drug Administration (FDA) refused to approve a generic version of the popular pain-killing drug OxyContin, on the very day that the drug’s patent was set to expire. Why? OxyContin (a narcotic) has become an abused prescription drug, in part because the pills could be crushed and then injected or snorted, releasing high levels of narcotic all at once. The FDA feared that widespread availability of generic OxyContin would lead to even more abuse of the drug. So in an unusual move, the FDA chose instead to approve a newly-patented, reformulated version of OxyContin that is harder to abuse. When crushed, the new OxyContin becomes a jelly-like mass that can’t be injected or snorted. The potential safety benefits of the newer version were so compelling that the FDA was willing to phase out the old version.
But don't expect the old version of OxyContin to disappear just yet. It turns out that generic OxyContin has been approved for sale in Canada. Canadian pharmacies are likely to have it for sale within a month.
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