Friday, September 16, 2005

Please Stand By...

Your regularly scheduled blog has been temporarily interrupted while the blogger is off on a retreat for new graduate students. In the event of an emergency or a critical need for skeptical analysis of current pseudoscience or quackery, please contact the blogger on-call:

Autism Diva
Kevin Leitch's Left Brain / Right Brain
Orac's Respectful Insolence

Or you can seek skeptical care at your local Skeptic Ring blog.

Have a safe and skeptical week!


Thursday, September 15, 2005

Outside the Box or Around the Bend?

Many of the more sincere pseudoscience and "alternative" medicine supporters continually exhort those of us who are more skeptical to be "more open-minded", saying that we need to "think outside the box". I submit that there is a fine line between "thinking outside the box" and "going around the bend".

A few years ago, in a university far, far away, our department chairman decided that the staff needed a motivational "retreat". So, he hired a motivational speaker and forced the entire department faculty to leave their comfortable homes and trek to a distant scenic resort. The motivational speaker, a perky thirty-something man by the name of Gerry ("Call me Gerry!"), started off by telling the assembled staff that "Nothing is impossible if you believe you can do it!"

Right off, it was clear that Gerry had a lot to learn about reality. I was silently wishing that Gerry would get it in his head to believe that he could fly and would thus end our torment while he learned some important points about gravity. But that was not to be.

Gerry called his particular brand of nonsense "thinking outside the box". He told us that we needed to not be stopped by "the way things are done" and come up with novel, "solution-oriented" ways of doing "our core business". It rapidly became apparent that Gerry hadn't a clue what our "core business" was.

In the end, I learned about thirty minutes of useful information. Unfortunately, it took over sixteen hours for Gerry to impart that information. On the "feedback" form that Gerry asked us to complete, I listed a number of "solution-oriented" ideas for Gerry to apply to his "core business". I expect that he thought they were too "outside the box" for him to use.

Too often, people coming into a field that is new to them will see rules and procedures that appear clumsy or overly restrictive and want to eliminate them. They feel that their newcomer status allows them to "think outside the box" and are usually frustrated when people who have been in the field longer insist that they adhere to the same clunky, burdensome rules and procedures. If they stay in the field long enough, they almost always come to discover why those rules and procedures are the way they are.

One of the more burdensome and clunky rules that science has had to put up with for the past two centuries or more is the rule that hypotheses are not "fact" (or theory) until they have been successfully tested. This rule has stymied thousands (if not millions) of would-be scientists who are so convinced of their ideas that they feel that testing them is a pointless waste of time and effort.

For these expansive thinkers, this is especially irksome because their new ideas are so obviously correct that anyone who understands them should see their truth immediately. The demands for data and testing seem, to them, merely a distraction - a way for the entrenched old fossils in science to mask their inability to understand. If people would only be more "open-minded" - if they would only "think outside the box" - they would immediately comprehend the beauty and truth of it all.

From the perspective of one of the "entrenched old fossils", a lot of the "thinking outside the box" looks like "not understanding the underlying principles of the field". This sort of error is not limited to the scientific novice, either. Linus Pauling, Nobel Laureate in Chemistry (and recipient of the Nobel Peace Prize) made almost laughable mistakes when he strayed into biology and medicine. In his article "Orthomolecular Psychiatry" (will need JSTOR access - see here and here, as well) and the book of the same name, he showed clearly that he hadn't a grasp of the probabilistic nature of biology when he dismissed concerns that his results were not statistically significant.

If a winner of the Nobel Prize in chemistry could be so wrong when he strayed "across the hall" into a somewhat related field, what are we to make of the lesser mortals who disregard the principles of science because they are "thinking outside the box"?

Not all ex box thinking is suspect, however. Much of it is very useful and even insightful - if it stays within the realm of the possible. People who take Gerry's advice (remember "Call me Gerry!"?) too seriously are likely to end up wondering why people won't listen to them.

The best kind of "outside the box" thinking is guided by a thorough knowledge of the field - either from the "out of the box" thinker or from someone they are working with. As an example, interdisciplinary projects (when done right) are marvelous ways to "think outside the box". Members of the team come from different fields and can contribute not only their own particular expertise, but also their field's unique methods and experiences.

This is very different from what Linus Pauling did - he stormed into the fields of biology and medicine with the attitude that he knew more than anyone else. Those that agreed with him were "visionaries" and those that disagreed were simply unable to see his brilliance. In the end, he surrounded himself with like-thinking people and became more and more marginalized. A sad end for a man who thought that he was "thinking outside the box" and was really going "around the bend".

Regrettably, Linus Pauling was not the only Nobel Laureate to trip over his medal. Those things should come with warning labels: "CAUTION! DOES NOT GRANT SUPERHUMAN MENTAL POWERS!".

In 1973, for instance, Nikolaas Tinbergen shared the Nobel Prize in Medicine with Karl von Frisch and Konrad Lorenz for his contributions to animal behavior (ethology). In his Nobel lecture, Tinbergen - freshly hung with his Nobel wreath - ventured to explain autism as a response to environmental stress, ala Kanner and Bettleheim.

In doing so, he not only hopped on the "Refrigerator Mother" hypothesis of autism as it was sinking, but he also managed to set a nearly unbeatable record for shortest time between receiving the Nobel Prize and saying something really stupid about a field in which the recipient had little experience. Tinbergen thought that his experience - and it was vast experience - in animal behavior gave him special insight into autism. It might have, but it didn't.

So, all you mavericks out there who feel that your lack of education and experience in a field gives you a unique ability to see what those who have labored long and hard cannot, remember these two "cautionary tales". And try to keep an open mind about why the people who have been in the field for years and years may not be receptive to your startling insights. When they brush you off or ignore your input, try to think outside the box of "conspiracy and stubborness" and consider a truly novel idea:
You might be wrong.


Friday, September 09, 2005

The Coming Gold Rush

From the "Evidence of Harm" Yahoo group:

"With the news articles about the possibility of gold helping children with autism I wonder if something like this might help my grandson. I would like to know if anyone has given this to their child with autism."

Which was in response to a story by - who else! - Dan Olmsted, UPI's senior autism-mercury editor. In his story, Mr. Olmsted has tracked down one of the patients in Leo Kanner's landmark article on autism, Autistic Disturbances of Affective Contact (1943).

This man, identified as Donald T., is now 72 years old and experienced a significant, if not dramatic, improvement in his autistic behaviors at age 14 (or 12 - the story contradicts itself on this point) after receiving injections of gold salts as treatment for life-threatening rheumatoid arthritis (RA). Mr. Olmsted and - since the article - a growing number of parents of autistic children, postulate that the gold injections were the cause of his improvement. Puberty is another event that happened at about the same time, but was discounted.

Mr. Olmsted's understanding of how gold might help autism is - as you might expect - tied in with the autism-mercury hyposthesis. In his article, Mr. Olmsted explains it thusly, in a quote from JB and Lisa Handley of "Generation Rescue":
"It is no surprise that gold salts improved Donald T.'s 'autism.' As gold miners as far back as the Roman Empire would tell you, gold and mercury have a strong binding affinity for each other, and the gold salts likely acted as a rudimentary chelator to help Donald T. detoxify. (Mercury is used in gold mining to separate small particles of gold from sand.) "

Yes, mercury was (and still is) used to separate gold from its ore - metallic mercury. The gold dissolves (amalgamates) in the mercury. This reaction can only occur when both the gold and the mercury are in the metallic state.

The gold used to treat Donald T's RA was a salt - the gold was an ion and not able to amalgamate with metallic mercury. In addition, mercury in animal tissue is also either ionized or chemically bonded with organic groups (e.g. methyl, ethyl, phenyl...) and also not able to form an amalgam.

None of this seems to have stopped the speculation that gold may be either the next "cure" for autism or, at the least, a vindication of the much-battered chelation therapy.

Clearly, the current state of our knowledge of the chemistry of gold and mercury does not support the "chelation hypothesis". And the prospect of gold becoming the next "cure" for autism is very ominous.

I could go on and on about the potential toxicity of gold treatment, but I think that a 2001 study in the Annals of the Rheumatic Diseases said it the best:
"GST [gold sodium thiomalate] is more toxic than MTX [methotrexate] but it remains an effective alternative in patients in whom MTX may not be tolerated..."

Gold sodium thiomalate is injected gold and methotrexate is a cancer chemotherapeutic agent that is often used in more severe autoimmune diseases (of which RA is one).

In the right hands, with proper monitoring and for a disorder in which it is known to work, gold therapy is a useful - if not first line - treatment. However, our only indication that gold might help autism is a single case from the 1940's.

This rather slim reed of evidence is made even slimmer by the fact that gold therapy has continued in used to the present time. Gold therapy is used in severe cases of juvenile rheumatoid arthritis (JRA) often enough that at least a few autistic children with JRA must have been treated with gold.

Yet the first we hear of this startling new therapy option is from a case that occurred nearly sixty years ago.

Before embarking on this 21st Century Gold Rush, I hope that someone will bother to look and see if any autistic children receiving gold for JRA or other autoimmune disorders have reported the same sort of improvement.

Lives may be in the balance.

Injectible and oral gold are much more toxic - and have the potential for much longer-lasting toxicity - than almost any of the other therapies currently advocated for autism.

Let's look before we leap.


Tuesday, September 06, 2005

Locked-In and Threw Away the Key

Against the advice of my physician, I have gone over some of the posts sent to me from the "Evidence of Harm" group on Yahoo. This has probably done irreparable harm to my stomach, but I hope it was worth it.

Here is one of the bits of unreason sent to me - the data is apparently the date it was posted. My commentary is in italic.

1 Sept 2005

Dr. Buttar is a polarizing figure. Why?

My thoughts:

1. He sat in front of Congress and said a very high number of kids recovered using TD-DMPS. But, he has never published anything, videotaped anything, or has shown us these kids. In a world where everyone has been burnt by a "cure", this will make parents very suspicious.

My thoughts exactly.

2. He apparently has a financial interest in TD-DMPS. I don't know if these means he gets $50 a year in royalties or $500,000 a year, but it makes him seem like a profiteer.

If he's only getting $50 a year, he's being cheated - his cream would have to be 36% gold (at 6 Sept 2005 spot prices) to cost $160 an ounce to produce.

3. He is a bull-in-a-china-shop personality. This guy is a formerArmy officer, a former bouncer, physically imposing, who happens to also be very smart. He suffers fools poorly and lacks a bit of the diplomacy that someone in his position may need to navigate these times.

In my experience, people who bluster and posture generally do so because they don't have the data to support their position.

4. Because of all of the above, it is a natural human behavior to project our intense frustration over what has happened to our children (and our respective lives) because of autism onto him. He is a very easy target.

So, the guy is polarizing. But, there is another side:

1. As someone who sees every email Generation Rescue receives, TD-DMPS is the overwhelming choice of parents reporting gains in their kids. Could this change? Absolutely. But, that's today's reality.

A very biased sample - I doubt that people who aren't chelating their children are going to report this to Generation Rescue.

2. We use 4 different Doctors to get advice about treating my son. After a long wait, we got a chance to speak with Dr. Buttar. My wife and I think we are pretty knowledgeable about our son. Buttar taught us things no other Doctor has. He knows his stuff. Period.

Buttar either taught them things they didn't know or things that weren't so - take your choice. He may know his stuff, but what is "his stuff"? How to maximize his bottom line?

3. If you spend time with him, most people quickly realize he is a God-loving Southerner who loves kids and wants, intensely, for them to get better.
Being charismatic is not the same as being competent - or even ethical. And Edgar Ray Killen is a "God-loving Southerner who loves kids" - let's hope this isn't what the author meant.

4. A film crew doing a documentary wanted to film Buttar and his recovered patients. I set up the visit. Buttar produced the families with the recovered kids. It's on tape.
Film of "recovered children" is just a testimonial on video. The plural of anecdote is not "data".

5. A Doctor has been out to review Buttar's records and claims. I know this for certain. This Doctor claims it is all true, I know this, too. Is that a peer-reviewed study? Hell no, but I'm not waiting.
Come on, "a Doctor"? Name? Purpose of the review? Good thing you're not waiting for Dr. Buttar to publish his findings - it would be like waiting for Godot.

6. If you can't find, on your own, the scientific proof that DMPS actually chelates mercury, you aren't trying. The only question is whether DMPS works in a transdermal form. Here are some thoughts:

- What doesn't the skin absorb that it comes in contact with? Isn't that part of the whole problem? Isn't that why my son has antimonypouring out of his body, because he absorbed it from his pajamas,matress, and car seat? It's our largest fu%%ing organ!!!
While the skin is the largest organ, it doesn't absorb MOST things it comes in contact with. If it did, we'd be in the same situation as the amphibians. Oh, and only a very small part of the skin is involved in "fu%%ing".

- If you think TD-DMPS doesn't work, here's a simple idea. Do a challenge dose on yourself. Just put 80 drops on your skin and seewhat happens. I try everything we put on or in my son. I did this. Just do it, then report back.
I'll bite - what happens? What happens when a neurotypical adult uses transdermal DMPS? Did you become less autistic? That's the REAL question, isn't it?

Leave Buttar alone. If you are venting at him, look inside yourself.If you don't believe in TD-DMPS, don't use it. Write to GenerationRescue and explain that you tried and it did not work. Don't roach other people's buzz because it did not work for you. Oh, and if you gave it less than 18 months, that may not have been enough time. Yes, that is a brutal paradox - we are running out of time!!! But, the sad reality is chelation takes a long time. If someone says, "I tried TD-DMPS for 3 months and it did not work" - that is not credible.
What?!?!? Chelating for less than 18 months isn't enought time!? Eighteen WEEKS is more than enough time, if you're using a competent chelating agent.

I might also point out that 18 months in the life of a young child is an EXTREMELY long time. Think of all the development that occurs in "typical" children in that time. My niece went from being able to say only a few fragmentary words to speaking in full sentences in that amount of time. Without TD-DMPS.

And I understand that Dr. Buttar wants parents to commit to a full two years of TD-DMPS treatment. At $160 a month (assuming you use an ounce a month), that's $3840 for two years. Add in the $800 an hour consultations, lab tests and travel expenses and you're talking about some real money.

And it seems odd to tell people that don't get any results from TD-DMPS to not "roach other people's buzz" - by which I assume the author means to keep quiet and not disturb other people with the possibility that TD-DMSP is a placebo. The phrase used is surprisingly apt - it suggests that the good feelings parents get from using TD-DMPS are as illusory as a marijuan "high". Very apt, indeed.

As you can see, the autism-mercury movement is not exactly in touch with reality as we know it. In this one post (authored by a prominent member of the autism-mercury movement), we see the following:

[1] Excusing a person who is clearly profiteering from the parents of autistic children because he is "on our side".

[2] Accepting the unsupported (by anything!) "word" of a man that the cream he makes and sells at exorbitant cost is the only treatment that will cure the mercury poisoning that he diagnoses in children during an $800 consultation. You'll note that Dr. Buttar is very clear that parents should "accept no substitutes!" (see here).

[3] "It works because I say it works!" - even the author could not explain how they knew that the TD-DMPS was absorbed, other than to say that they tried it on themselves and "knew".

[4] Discouraging people from discussing treatment failures. Both the "if you gave it less than 18 weeks, that may not have been enough time" and the apt "[d]on't roach other people's buzz" comments encourage the "proper" mindset - if the treatment fails, it's your fault and "we don't want any negative thinking".

So, uncritical acceptance of information from "our" people and actively discouraging a frank and open discussion of the limitations and failures of the treatment advocated. Sounds like Scientology, not science.


(Next: More from the EoH garbage bag).

Sunday, September 04, 2005

Locked-In Syndrome

Locked-in Syndrome, according to the National Institute of Neurological Disorders and Stroke (NINDS):

"Locked-in syndrome is a rare neurological disorder characterized by complete paralysis of voluntary muscles in all parts of the body except for those that control eye movement."

However, there appears to be another type of "locked-in syndrome", one caused by overdosing on autism-mercury rhetoric. In this form of locked-in syndrome, there is paralysis of the faculties of reason, rather than the voluntary muscles.

My source of clinical material for this new syndrome has come from the "Evidence of Harm" (EoH) group on Yahoo. This group has attracted the leaders of this movement and is a sort of "nerve-center" for dissemination of autism-mercury material.

A good example of the EoH "group-think" is this poll they have on their site (spacing edited for clarity, emphasis added):

This poll has two parts. Assuming that mercury in vaccines is responsible for a large fraction of autism spectrum disorders, and that mercury began to be removed from vaccines in 1999 in the USA: When do you expect autism rates to substantially decrease?

The second part of the question is: If autism rates have not begun to substantially fall at the date you choose in the first part, please explain why that would not have happened. You may choose more than one reason.

[] Autism rates should already have fallen substantially in the first half of 2005
[] Autism rates should fall substantially in the last half of 2005
[] Autism rates should fall substantially in the first half of 2006
[] Autism rates should fall substantially in the second half of 2006
[] Autism rates should fall substantially in 2007
[] Autism rates should fall substantially in 2008
[] Autism rates should begin to fall, but I don't think they will fall substantially until 2009 or later

[] If rates don't fall, it would mean that mercury from other sources, e.g. atmospheric, is responsible
[] If rates don't fall, it would mean that trace amounts of mercury in vaccines continue to be responsible
[] If rates don't fall, it would mean that big pharma is lying about the mercury content of vaccines
[] If rates don't fall, it would mean that children are becoming more sensitve to mercury poisoning
[] If rates don't fall, it would mean that the autism-mercury hypothesis is incorrect
[] If rates don't fall, it would mean that some other reason, other than mentioned above is responsible

Your vote is shown above. You can change your vote until the poll is closed.

Anyone want to guess what the results were when my informant checked it? Any guesses what the "big winners" were? The use of the term "big pharma" is a big red flag here - and I don't mean that it's May Day.

[] Autism rates should already have fallen substantially in the first half of 2005 [4 votes, 3 %]
[] Autism rates should fall substantially in the last half of 2005 [5 votes, 4%]
[] Autism rates should fall substantially in the first half of 2006 [8 votes, 6%]
[] Autism rates should fall substantially in the second half of 2006 [10 votes, 8%]
[] Autism rates should fall substantially in 2007 [10 votes, 8%]
[] Autism rates should fall substantially in 2008 [4 votes, 3%]
[] Autism rates should begin to fall, but I don't think they will fall substantially until 2009 or later [9 votes, 7%]

[] If rates don't fall, it would mean that mercury from other sources, e.g. atmospheric, is responsible [6 votes, 5%]
[] If rates don't fall, it would mean that trace amounts of mercury in vaccines continue to be responsible [12 votes, 10%]
[] If rates don't fall, it would mean that big pharma is lying about the mercury content of vaccines [26 votes, 22%]
[] If rates don't fall, it would mean that children are becoming more sensitve to mercury poisoning [6 votes, 5%]
[] If rates don't fall, it would mean that the autism-mercury hypothesis is incorrect [6 votes, 5%]
[] If rates don't fall, it would mean that some other reason, other than mentioned above is responsible [12 votes, 10%]

Unfortunately, 85% of survey takers felt that, even if the autism rates don't fall, autism is still caused by mercury - either environmental, "trace" amounts or deception by "big pharma". In other words, 85% were "locked-in" to the idea that mercury is the cause of autism - forever and always, world without end, Amen.

I don't see any reason to try to convince the autism-mercury believers of the error of their ways - I don't go in for pointless effort or hopeless causes. Even if we had incontrovertible proof, they would pass it off as "biased", "flawed" or "corrupt". Yet they continually bleat that they want "more studies". Why? They haven't believed the ones so far.

Yet, we cannot give up the struggle against ignorance because there are still people out there who are looking for answers (the autism-mercury movement has found their answer) and they need a rational counterbalance against the autism-mercury dogma.


Saturday, September 03, 2005

A Little Math Test for Generation Rescue

According to the Generation Rescue website's self-serving explanation of the death of Abubakar Tariq Nadama, who was killed when he received chelation with EDTA for either lead or mercury toxicity (but actually for autism), the number of children receiving chelation for autism is about 10,000. Actual quote:
"We estimate there are 10,000 autistic children today receiving some form of chelation therapy, up from a handful five years ago."

QUESTION: With 10,000 children receiving the treatment and one (1) death, what is the mortality rate per million children treated?

ANSWER: 100 deaths per million treated.

QUESTION: If the actual number of children being chelated is less than 10,000, will the number of deaths per million treated go up, go down or stay the same?

ANSWER: Go up.

QUESTION: Since the smallox vaccine is considered to be one of the most dangerous modern vaccines - so much so that plans to vaccinate medical and emergency response personnel were scrapped despite concerns that smallpox would be a good biological terror agent - what is the mortality rate for smallpox vaccine?

ANSWER: 3.5 deaths per million treated.

QUESTION: What is the mortality rate for childhood vaccines?

ANSWER: Less than 1 per million treated.

QUESTION: Which number is largest: 1, 3.5 or 100?

ANSWER: 100.

Please be sure that your name is on your test paper and hand them in before the end of class.


Friday, September 02, 2005

String of Pearls

In my relatively short tenure as a blogger, I have posted a fair bit about autism and mercury. This is not necessarily by design - I have simply followed where the current led. During this time, I have had a number of people try to show me the error of my ways - that there is data supporting the hypothesis that mercury causes autism.

These people have been, in turn, collegial, insulting, threatening and accusing. A few have even been comical, although I don't think that was their intent. The majority of them (at least, those that tried to use reason) have presented a series of studies and other findings which they believe show that mercury causes autism.

What they are doing is known by a number of different names - the name I am most familiar with is data chaining. In mathematics, this is a solid theorum - if A = B and B = C, then it follows that A = C. In the biological sciences, this is not always so straighforward, but it can be deduced that if A causes B and B results in C, then A can cause C (although A may not be the only cause of B or C).

In biology, the use of data-chaining has led some investigators to make claims they later regretted, usually because they failed to consider the following caveats:

[1] Even if A causes B, it may not be the only cause.
[2] If A and B occur together, one is not necessarily the cause of the other.
[3] Biology is probabilistic, not stochastic. (In other words, organism vary, even within a sub-species)
[4] A biological organism - even the simplest - is a complex of interconnected systems that are only partially known.

The autism-mercury supporters tend to use data-chaining in a very cavalier way, as in the following simplistic example:

[1] Mercury is known to cause brain injury. true
[2] Autism is a brain disorder. also true
[3] Children are exposed to mercury in the form of thimerosal in vaccines. was true, is less true now
[4] Ergo, autism is caused by mercury.

Now, this is admittedly a very easy "chain" to break, but it is also a widely quoted one, so the example is valid. To "break" this chain, all you have to do is note the lack of solid connection between the data used. In this example, it is true that mercury causes brain injury, but the injuries documented over the past hundred years or so have not looked like autism. Some of the individual symptoms or signs may share a certain similarity to autism, but the presentations as a whole are vastly different.

By showing the lack of connection between the "facts" used in this data-chain, it becomes apparent that what we actually have is a series of separate "facts" with an implied connection, something that another writer called a "string of pearls". A "string of pearls" is a beautiful group of data without any visible connection.

Another string of pearls appears in Dr. Hornig's presentations to autism groups. She found that different strains of mice had different susceptibilities to thimerosal. Not suprisingly, a strain that was known to be susceptible to autoimmune disorders did poorly - although they did not specifically look for signs of autoimmune disorders. Curious.

This is her string of pearls - it's a bit more complex:

[1] Children get thimerosal-containing vaccines at ages 2, 4, 6 and 12 month.
they used to, not any more

[2] The developmentally-equivalent ages in mice are 7, 9, 11 and 15 days.
true for certain aspects of development - human infant brain development is much different from that of a mouse in many ways

[3] Giving infant mice thimerosal at ages 7, 9, 11, and 15 days is equivalent in timing to giving thimerosal to infant humans at 2, 4, 6, and 12 months.
only in timing - the metabolism and elimination of thimerosal has not been shown to be equivalent

[4] Humans are genetically diverse.

[5] The SJL/J, C57BL6/J, and BALB/cJ strains of mice are genetically different.
true, but not in ways that are necessarily equivalent to human genetic diversity

[6] Some autistic humans show decreased interest in their environment.

[7] The SJL/J (autoimmune disorder susceptible) mice treated with thimerosal showed decreased locomotion and exploration of their environment - this is similar to what is seen in autistic humans ([6]).
this is a pretty big assumption - a better explanation for the decreased locomotion and exploration is that the SJL/J mice were ill from autoimmune disorders that were not tested for

[8] Some autistic humans are averse to novel situations.

[9] Thimerosal-exposed SJL/J mice showed increased exploration in a novel environment.
it is hard to see how this can be seen as an analogue to [8], but that was the implication

[10] Self-injurious behavior is seen in some autistic humans.

[11] Some of the thimerosal-exposed mice repeatedly bit their tails.
this is also seen in partial denervation in mice and rats and may simply be a sign of mercury toxicity. Humans do not bite partially denervated limbs

In the final analysis, Dr. Hornig has found out that SJL/J strain mice - who are known to be susceptible to autoimmune disorders - also react poorly to mercury. The other mouse strains in this study did not. She also - and I know I'm being repetitive here - did not test the SJL/J mice for signs of autoimmune disorders. That could have explained many of the results.

Interestingly, it appears that the SJL/J strain of mice has a much lower ability to excrete mercury, which would then lead to a higher tissue level. It's a pity Dr. Hornig didn't get hair and blood samples from these mice - we would then have a chance to see if the string of pearls proposed by Holmes et al (and here) has any validity. Oh, well.

So, the next time somebody says that they have "incontrovertible proof" of something based on a study that shows A causes B and B is seen in cases of C, look for the string connecting the pearls. It may not be there.