On Tuesday, I had knee surgery. To be more specific, I had an arthoscopic procedure intended to help repair an old injury which had gotten very much out of hand.
To detail the situation, my left knee's lateral meniscus was out of place, folded on top of itself, and torn. There was also bone damage, and some of the remaining cartelage had become detached. While the meniscus wasn't salvageable, the remaining damage was successfully repaired... although there was a bone graft involved.
Needless to say, I am not enjoying the recovery. Among other things, vicodin has a very strong negative impact on my ability to follow the peer-reviewed literature. This is a major annoyance to me (frankly, more of one than the fact that I'm now way behind on my e-mails).
Oh, and bone grafts really, really hurt... even with major narcotics. Attempting physical therapy activities with a knee that's swollen to the literal size of a grapefruit isn't very pleasant, either.
In summary, I don't have much energy (or attention span) available for blogging right now. Sorry about that.
Saturday, February 6, 2010
Friday, January 29, 2010
A Quick Note
As I write this, I'm at the 17th Annual CARD Conference in Lake Mary, Florida, waiting for the poster sessions to open. I brought a copy of Ioannidis, 2008 for leisure reading, and was struck by the following quote:
This description seems... awfully familiar. <sarcasm>I wonder just what field I'm thinking of.</sarcasm>
On the other hand, research in a field with small studies, strong conflicts of interest, intense competition for generating 'positive' results and prior documentation of publication bias should have high prior odds of bias before doing the meta-analysis [25]. Even if no signal is shown in statistical tests for bias, the odds of bias remain high.
This description seems... awfully familiar. <sarcasm>I wonder just what field I'm thinking of.</sarcasm>
Thursday, January 28, 2010
On Highly Misleading News Articles
Catching up on a newsfeed, I came across this article. Suffice it to say I wasn't impressed -- at all.
In essence, the article reports data from the National Birth Defect Registry and notes that "over 60%" of autistic children entered into their database had some form of structural birth defect as well as an autism diagnosis. I was pretty surprised at this news -- just not by the fact that the number was so high.
My surprise was at two things: One, that they considered this news... and, two, that the number was so low.
You see, the registry relies on parents to input data on their children. Specifically, it requires parents to register their children with birth defects.
Obviously, this means that not every child with a birth defect gets entered. More importantly, parents will only enter their children if they believe that said children have birth defects.
Now... how many parents of autistic children consider autism a birth defect?
The news story suggests that the answer is higher than I thought. Of course, it may just be that some of the remaining 40% have other issues. I don't know -- I haven't seen the data.
This, of course, is what is known as selection bias. More specifically, it's a blatant case of sampling bias.
In other words -- why the heck is this news?
The answer: media sensationalism. Frankly, publication of this article fails pretty much any accepted standard of journalistic ethics, specifically because of accuracy standards and the harm limitation principle. On the other hand, that's never stopped the publication of countless other sensationalized articles...
In essence, the article reports data from the National Birth Defect Registry and notes that "over 60%" of autistic children entered into their database had some form of structural birth defect as well as an autism diagnosis. I was pretty surprised at this news -- just not by the fact that the number was so high.
My surprise was at two things: One, that they considered this news... and, two, that the number was so low.
You see, the registry relies on parents to input data on their children. Specifically, it requires parents to register their children with birth defects.
Obviously, this means that not every child with a birth defect gets entered. More importantly, parents will only enter their children if they believe that said children have birth defects.
Now... how many parents of autistic children consider autism a birth defect?
The news story suggests that the answer is higher than I thought. Of course, it may just be that some of the remaining 40% have other issues. I don't know -- I haven't seen the data.
This, of course, is what is known as selection bias. More specifically, it's a blatant case of sampling bias.
In other words -- why the heck is this news?
The answer: media sensationalism. Frankly, publication of this article fails pretty much any accepted standard of journalistic ethics, specifically because of accuracy standards and the harm limitation principle. On the other hand, that's never stopped the publication of countless other sensationalized articles...
Thursday, January 21, 2010
Restraint & Seclusion Legislation National Call-In Day
Today is Restraint & Seclusion Legislation National Call-In Day. Lacking the energy to do a proper write-up, I'm just going to copy ASAN's announcement on the topic.
I've made one minor alteration, by removing a text-based spelling out of a URL and replacing it with a link.
I've made one minor alteration, by removing a text-based spelling out of a URL and replacing it with a link.
Dear Friends, Advocates and Community Members,
In one week, Congress will come back in session. The Autistic Self Advocacy Network (ASAN), in conjunction with the Alliance to Prevent Restraint, Aversive Interventions and Seclusion (APRAIS), is asking you to join us in a National Call-In Day on Thursday, January 21st to tell your members of Congress to support the Preventing Harmful Restraint and Seclusion in Schools Act (H.R. 4247/S.2860) introduced last month by Representatives George Miller (D-CA) and Cathy McMorris-Rodgers (R-WA) and Senator Chris Dodd (D-CT). This legislation would provide students with and without disabilities vital protections against abuse in schools. We are providing details on how to contact your members of Congress -- please distribute this announcement widely.
WHAT YOU CAN DO:
Please call this coming Thursday and encourage your friends, family and coworkers to participate by dialing the Capitol Switchboard at 202-224-3121 and asking for your Congressional representative to Co-Sponsor H.R. 4247, and your senators to Co-Sponsor S. 2860.
• To find out the names of your US Senators and Representative, click here
• Ask for the offices of your US Senators and Representative
• Ask to speak to the person working on education issues
• Identify yourself as a constituent and the organization that you represent (if any)
Message: " I am calling to urge (Senator y) to cosponsor S.2860, legislation preventing harmful use of restraint and seclusion in schools."
Message: "I am calling to urge (Representative z) to cosponsor HR 4247, legislation preventing harmful use of restraint and seclusion in schools."
Thanks for your advocacy. Increasing congressional support for these bills will help move them through the legislative process towards enactment. Please call on January 21, 2010 and tell your friends and family to join you. If you are interested in doing more, please e-mail us at info@autisticadvocacy.org for information about how you can arrange a meeting with your representatives to explain why this bill is essential or visit www.tash.org/aprais to learn more.
Regards,
The Autistic Self Advocacy Network and the APRAIS Coalition
Saturday, January 9, 2010
On Exhaustion, Part Two
I have memory issues -- pretty significant ones, at that. Without the extensive use of mnemonic devices and various external memory aids, I wouldn't be able to make it through the day. Despite this, my memory significantly outperforms most people's in many respects. It's one of the many ironic aspects of my life.
When I'm especially tired, however, another aspect of this pops up. My memory issues get worse and worse as I sink into exhaustion. As if this wasn't bad enough, however, when my exhaustion passes a certain point, I start to actually misremember various things. While this starts with minor details, it progresses if I don't get some desperately-needed rest.
I passed that point yesterday.
This is very much not a good thing. Fortunately, I detected what was going on pretty early and excused myself from an ongoing advocacy case to get the rest I needed. I won't be doing any direct work in that for a while.
When I'm especially tired, however, another aspect of this pops up. My memory issues get worse and worse as I sink into exhaustion. As if this wasn't bad enough, however, when my exhaustion passes a certain point, I start to actually misremember various things. While this starts with minor details, it progresses if I don't get some desperately-needed rest.
I passed that point yesterday.
This is very much not a good thing. Fortunately, I detected what was going on pretty early and excused myself from an ongoing advocacy case to get the rest I needed. I won't be doing any direct work in that for a while.
Wednesday, December 30, 2009
A Few Things You Probably Didn't Know About Hyperbaric Oxygen Therapy
As with megavitamin "therapy", hyperbaric oxygen as a "treatment" for autism can be accurately classed as too much of a good thing.
In medicine, too much of a good thing can be a very bad thing, and the research reflects this. Essential nutrients can easily become poisons if you consume too much of them, and many of today's common medical problems can be laid at the feet of too much consumption of essential macronutrients... and macronutrients are generally far better tolerated than the micronutrients which are used to excess in "megavitamin therapy".
In fact, hyperbaric oxygen chambers allow for a greater exposure to oxygen than would normally be theoretically possible. Put into more technical language, a hyperbaric chamber allows for partial pressures of oxygen within the lung that wouldn't be possible without active pressurization.
While this isn't the only mechanism of action for HBOT (for instance, the increased overall pressure has therapeutic value when treating decompression sickness), it's the main one, and the one which most of the various explanations of HBOT as an autism treatment hinge upon. Specifically, increased partial pressure is increased effective in-lung exposure to oxygen, and this is supposed to increase oxygen content in the bloodstream, increase oxygen flow to the brain, etc., etc.
Oxygen qualifies as a drug when used this way. As with vitamins, it's quite possible to overdose on it. This is known by a variety of names, but the most common of these are "oxygen toxicity" (for the phenomenon) and "oxygen poisoning" (for the medical condition).
Frankly, oxygen poisoning can be nasty. At lower levels, oxygen is a very good thing. At higher levels... it isn't. In fact, oxygen has neurotoxic properties at high enough doses, and these doses are acheivable even without a hyperbaric chamber.
So, if that's the case, why is it that that we don't see autistic children vomitting, suffering from tunnel vision and shortness of breath, convulsing, twitching, and generally showing the symptoms of oxygen poisoning after HBOT? The answer is actually rather simple -- and says a lot about the people peddling HBOT for autism.
The partial pressure of a gas within a mixture is equal to the percentage of the mix formed of that gas times the total pressure of the gas. So, for instance, the partial pressure of oxygen in a gas mixture which contains 20% oxygen and is held at 1 bar (normal atmospheric pressure) is .2 bar. Doubling either the percentage of gas or the overall pressure of the mix will also double the partial pressure of oxygen, yielding a partial pressure of .4 bar.
It's worth noting that a partial pressure of up to about one bar (depending on altitude, weather patterns, and just about anything else that effects atmospheric pressure) is achievable without pressurization -- 1 bar is the partial pressure of oxygen in a pure oxygen "mix" at normal atmospheric pressure. Keep that in mind as I continue.
A recent paper, using fairly typical practice for HBOT treatment for autism, used a 24% oxygen mix at 1.3 bar of pressure. Doing the math, this yields a partial pressure of about .31 bar... or roughly equivalent to what could be acheived by using a 31% oxygen mix without the hyperbaric chamber. It's actually pretty trivial to go to a SCUBA supply shop and buy a tank full of a mix that's richer in oxygen than that.
Of course, typical air is roughly 21% oxygen, meaning that the gas they used was only trivially different from room air in terms of oxygen content; the increase in partial pressure was almost entirely achieved by a raise in pressure.
While this sort of level is typical in practice, however, it's worth noting that I've seen documentation of much more "intense" regimens, ranging up to 100% oxygen at 1.5 bar. Caveat emptor -- and beware oxygen poisoning.
Finally, I suppose I should also mention that there's a second theorized action mechanism, involving gas transport via blood plasma (as opposed to the hemogloboin-based transport of red blood cells), which is increased substantially under hyperbaric conditions. This mechanism is equally implausible for reasons which are much harder to explain, but I should probably mention it in the interest of fairness.
Still -- 1.3 bar isn't enough pressure to make much of a difference there, either.
In medicine, too much of a good thing can be a very bad thing, and the research reflects this. Essential nutrients can easily become poisons if you consume too much of them, and many of today's common medical problems can be laid at the feet of too much consumption of essential macronutrients... and macronutrients are generally far better tolerated than the micronutrients which are used to excess in "megavitamin therapy".
In fact, hyperbaric oxygen chambers allow for a greater exposure to oxygen than would normally be theoretically possible. Put into more technical language, a hyperbaric chamber allows for partial pressures of oxygen within the lung that wouldn't be possible without active pressurization.
While this isn't the only mechanism of action for HBOT (for instance, the increased overall pressure has therapeutic value when treating decompression sickness), it's the main one, and the one which most of the various explanations of HBOT as an autism treatment hinge upon. Specifically, increased partial pressure is increased effective in-lung exposure to oxygen, and this is supposed to increase oxygen content in the bloodstream, increase oxygen flow to the brain, etc., etc.
Oxygen qualifies as a drug when used this way. As with vitamins, it's quite possible to overdose on it. This is known by a variety of names, but the most common of these are "oxygen toxicity" (for the phenomenon) and "oxygen poisoning" (for the medical condition).
Frankly, oxygen poisoning can be nasty. At lower levels, oxygen is a very good thing. At higher levels... it isn't. In fact, oxygen has neurotoxic properties at high enough doses, and these doses are acheivable even without a hyperbaric chamber.
So, if that's the case, why is it that that we don't see autistic children vomitting, suffering from tunnel vision and shortness of breath, convulsing, twitching, and generally showing the symptoms of oxygen poisoning after HBOT? The answer is actually rather simple -- and says a lot about the people peddling HBOT for autism.
The partial pressure of a gas within a mixture is equal to the percentage of the mix formed of that gas times the total pressure of the gas. So, for instance, the partial pressure of oxygen in a gas mixture which contains 20% oxygen and is held at 1 bar (normal atmospheric pressure) is .2 bar. Doubling either the percentage of gas or the overall pressure of the mix will also double the partial pressure of oxygen, yielding a partial pressure of .4 bar.
It's worth noting that a partial pressure of up to about one bar (depending on altitude, weather patterns, and just about anything else that effects atmospheric pressure) is achievable without pressurization -- 1 bar is the partial pressure of oxygen in a pure oxygen "mix" at normal atmospheric pressure. Keep that in mind as I continue.
A recent paper, using fairly typical practice for HBOT treatment for autism, used a 24% oxygen mix at 1.3 bar of pressure. Doing the math, this yields a partial pressure of about .31 bar... or roughly equivalent to what could be acheived by using a 31% oxygen mix without the hyperbaric chamber. It's actually pretty trivial to go to a SCUBA supply shop and buy a tank full of a mix that's richer in oxygen than that.
Of course, typical air is roughly 21% oxygen, meaning that the gas they used was only trivially different from room air in terms of oxygen content; the increase in partial pressure was almost entirely achieved by a raise in pressure.
While this sort of level is typical in practice, however, it's worth noting that I've seen documentation of much more "intense" regimens, ranging up to 100% oxygen at 1.5 bar. Caveat emptor -- and beware oxygen poisoning.
Finally, I suppose I should also mention that there's a second theorized action mechanism, involving gas transport via blood plasma (as opposed to the hemogloboin-based transport of red blood cells), which is increased substantially under hyperbaric conditions. This mechanism is equally implausible for reasons which are much harder to explain, but I should probably mention it in the interest of fairness.
Still -- 1.3 bar isn't enough pressure to make much of a difference there, either.
Monday, December 21, 2009
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