More damning Tyler stuff

Robert Chung Wrote:
You're saying 6% is too low to be detected using FACS?

Definitely not. 6% of cells being different antigenically would be
detected. However, that seems to be more for twin-twin transfusions.
Post-transfusion micro-chimerism I am sure would be much less than 6%.


I guess this just sways things to the side of micro-chimerism being
incredibly rare.

1. What makes you think it would be easy for anyone other than an
approvedlab to do?

It is not hard to test for. Many labs could do it and Phonak could
easily approach any number of these. It just isn't frequently tested
for because generally there isn't reason to.


--
patch70

"Stewart Fleming" wrote in message
...

Tom Kunich wrote:

"Stewart Fleming" wrote in message
...

Curtis L. Russell wrote:


Well, its a good thing that the Scottish Parliamentary Building
doesn't have to float. That money could have put a fleet on the ocean.
And it has to put a hole in at least one stereotype in the U.S. - the
stingy Scot.

Andrew Carnegie.

Great AMERICAN.

Which state is Dunfermline, Fife in again?

Would you be supposing that the land where a man is born somehow infuses him
with a sort of magic that makes him succeed where other's fail?

Or that the land where he grew and prospered offered him the education and
the chance he might not have gotten anywhere else.?

Carnegie was the quintessential American.

"Mike Murray" wrote in message
news:Xx4Ad.292924$HA.226787@attbi_s01...
There is an issue that has been missed in this discussion. Even if the
test does work well to detect small amounts of antigenicallly dissimilar
RBCs in a sample, which it likely does as this has been the use of the
test in other settings, I don't think anyone knows what the incidence of
having this is in the absence of transfusion. Suppose that having a small
number of heterogeneous RBCs without transfusion is relatively common, say
1 in 10,000 it would require running a few 100 thousand tests before this
would be evident. I am not aware that this issue has ever been looked at
before. In other words, the test may work technically but may have an
unacceptable number of false positives when used to determine whether
blood has been transfused.

My thoughts as well Dr. Murray.

patch70 wrote:
Robert Chung Wrote:
You're saying 6% is too low to be detected using FACS?

Definitely not. 6% of cells being different antigenically would be
detected. However, that seems to be more for twin-twin transfusions.

Boom. Game's over. You've just admitted that there would be a non-zero
rate of false positives using this technique, which is the only thing I've
been arguing. Thanks a lot for playing.

"Robert Chung" wrote in message
...
patch70 wrote:
Robert Chung Wrote:
You're saying 6% is too low to be detected using FACS?

Definitely not. 6% of cells being different antigenically would be
detected. However, that seems to be more for twin-twin transfusions.

Boom. Game's over. You've just admitted that there would be a non-zero
rate of false positives using this technique, which is the only thing I've
been arguing. Thanks a lot for playing.

I think it's been clear to most intelligent readers of r.b.r. that "patch70"
lost this game a long time ago - he just wasn't smart enough to realize it.

Andy Coggan

Robert Chung Wrote:
Boom. Game's over. You've just admitted that there would be a non-zero
rate of false positives using this technique, which is the only thing
I've been arguing. Thanks a lot for playing.

Wow! You really are stupider than you seem. I didn't think that would
be possible. You too Andy Coggan.

Can you please show me any test for anything that has a zero false
positive rate? Of course not. There are none. It is just the rate that
varies depending on sensitivity, specificity and pre-test prior
probability.

What do you think is the probability of Tyler, Santi or any other elite
cyclist being a chimer? Very, very low. What is the probability that two
pro cyclists from the same team are using the same doping technique? A
lot higher than the chance that they are the only two chimers
accidentally picked up by this test.

I wonder if you guys would be arguing so passionately about the
possible flaws of a good test if it were Santi Perez & Andreas Kloden
who were caught??? Of course not.


--
patch70

Andy Coggan Wrote:
I think it's been clear to most intelligent readers of r.b.r. that
"patch70" lost this game a long time ago - he just wasn't smart enough
to realize it.

Andy Coggan

Sorry for making it too complicated for you to understand. If you need
it simpler, just ask.


--
patch70

"Andy Coggan" wrote in message
ink.net...
"Robert Chung" wrote in message
...
patch70 wrote:
Robert Chung Wrote:
You're saying 6% is too low to be detected using FACS?

Definitely not. 6% of cells being different antigenically would be
detected. However, that seems to be more for twin-twin transfusions.

Boom. Game's over. You've just admitted that there would be a non-zero
rate of false positives using this technique, which is the only thing
I've
been arguing. Thanks a lot for playing.

I think it's been clear to most intelligent readers of r.b.r. that
"patch70" lost this game a long time ago - he just wasn't smart enough to
realize it.

Come on Andy. Patch is a doctor and as such plays the odds. The chances of
Hamilton and Santi BOTH on the same team and testing positive and no one
else on all of the teams testing positive and there being chimerics involved
in both cases is vanishingly small.

The odds are really long and in favor of Patch.

The rest of us are just hoping for a miracle and you know it.

"patch70" wrote:
"Given that all your red cells come from the same stem cells, why would one
have a heterogeneous population?"

It would occur if there was a heterogeneous stem cell population or if there
was an acquired change in the antigenic profile of some of the red cells,
either due to an acquired change in some of the stem cells or due to an
antigenic change to the RBCs themselves. I have no idea if this occurs or
not. Has it been investigated?

"patch70" also wrote:
"The old microchimerism is back again.
(1) How common is it in healthy, male elite athletes? (ie people without
autoimmune conditions or those who've had stem cell transplants - either way
would not be doing grand tours. Also, mainly reported in women following
pregnancies.) Answer - It is rarer than hen's teeth."

Do you have any references of that being investigated? I agree that it
would be expected to be very unlikely but has anyone looked at a significant
number of "normals"?

One of the previously posted references included the satement:
" studies also indicate microchimerism is not uncommon in other human
conditions and in healthy individuals."

Many of the autoimmune syndromes would not preclude participation in grand
tours and are quite common.

I agree that the most probable explanation is that Tyler had a transfusion
but without actually looking at a significant number of normals any
statement about how probable is just a guess.

One would expect that cellular gender chimerism or mosaicism would be pretty
rare in elite level athletes too, which it is, but it has turned up in the
past gender testing at the Olympics.

Mike Murray

Tom Kunich wrote:

Patch is a doctor and as such plays the odds.

Part of the reason why there is variability in health care is because some
physicians play the odds while others treat the patients. That said, I'm
not always sure which produces the best quality of care.

The chances of Hamilton and Santi BOTH on the same team and testing
positive [...] is vanishingly small.

Perhaps, but the chance that there is one false positive among the two is
(roughly) twice as high as the chance of one.

The rest of us are just hoping for a miracle and you know it.

This isn't about Hamilton or Perez. It's about the test.