Author Topic: Another Switzer neg study published today?!  (Read 3554 times)

bullybeef

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Another Switzer neg study published today?!
« on: February 22, 2011, 07:39:40 PM »
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In 2009, a newly discovered human retrovirus, xenotropic murine leukemia virus (MuLV)-related virus (XMRV), was reported by Lombardi et al. in 67% of persons from the US with chronic fatigue syndrome (CFS) by PCR detection of gag sequences. Although six subsequent studies have been negative for XMRV, CFS was defined more broadly using only the CDC or Oxford criteria and samples from the US were limited in geographic diversity, both potentially reducing the chances of identifying XMRV positive CFS cases. A seventh study recently found polytropic MuLV sequences, but not XMRV, in a high proportion of persons with CFS. Here we tested blood specimens from 45 CFS cases and 42 persons without CFS from over 20 states in the United States for both XMRV and MuLV. The majority of CFS patients (31/45, 69%) had a minimum of 6 months of post-exertional malaise and a high degree of disability, the same key symptoms described in the Lombardi et al. study. Using highly sensitive and generic DNA and RNA PCR tests, and a new Western blot assay employing purified whole XMRV as antigen, we found no evidence of XMRV or MuLV in all 45 CFS cases and in the 42 persons without CFS. Our findings, together with previous negative reports, do not suggest an association of XMRV or MuLV in the majority of CFS cases.


See: http://www.retrovirology.com/content/8/1/12
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Robyn

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Re: Another Switzer neg study published today?!
« Reply #1 on: February 22, 2011, 07:43:58 PM »
Notice Brent Satterfield as well?  He's the owner of Cooperative Diagnostics.  Sheez Looks like Fauci's employee (The Editor of Retrovirology) is at it again with the publishing.  Wonder if this was another blood drop test?  Let's see they can pump one of these  bogus studies out in less than 3 weeks with only one person having to review the paper. Now exactly how long did it take on the peer review process for the Lombardi Science paper? 
« Last Edit: February 22, 2011, 07:51:02 PM by Robyn »
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belcanto

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Re: Another Switzer neg study published today?!
« Reply #2 on: February 22, 2011, 07:45:07 PM »
Interesting.  Sounds like they're responding to cohort criticisms.  And suggesting that they have highly sensitive tests and assays.

Methinks they protest too much?   

christopher

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Re: Another Switzer neg study published today?!
« Reply #3 on: February 22, 2011, 08:00:51 PM »
Am waiting for Gerwyn's take on it re: why their methods are flawed.

asleep

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Re: Another Switzer neg study published today?!
« Reply #4 on: February 22, 2011, 08:01:32 PM »
Retrovirology: Your #1 source for special interest and policy-driven science since Oct. 2009.

rebecca

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Re: Another Switzer neg study published today?!
« Reply #5 on: February 22, 2011, 08:05:13 PM »
Surprise, surprise, another 0/0 study.

Some problems:
-19/45 "CFS" patients were not diagnosed by a physician.  Pts in Lombardi et al. and Lo et al. were all phsyician-diagnosed.
-Cohort met Fukuda, which does not require patients to have lost ≥50% of their premorbid activity level.  Both the CCC (Lombardi) and Holmes Criteria (Lo) mandate a ≥50% loss of function.
-They did not prove their assays could detect HMRV in known positive blood samples: 
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Dilutions of DNA from XMRV-infected 22Rv1 human prostate carcinoma cells were used as positive controls in this test [15].  1.0 µg of DNA (333 ng of PBMC DNA) was used in the nested pol and gag PCR tests at the CDC for which 1,000 and 10 copies of the XMRV(VP62) plasmid were used as positive controls [1, 9].
Or, perhaps they did run their tests on known positive blood samples, and didn't mention they couldn't detect HMRV!  This was the case with the first Switzer study. (Mindy wrote in August, "One of the CDC slides from last week’s Blood Safety Advisory Committee meeting showed that the CDC tested 20 samples from Chronic Fatigue Syndrome (CFS) patients that the Whittemore Peterson Institute (WPI) found to be positive for the retrovirus XMRV.  But, according to the slide, the CDC didn’t find any positives among those 20.)   >:( >:( >:(

Bel, you're right...the authors of the new study sound defensive about cohort selection, even invoking the Bell Scale.   ::)
« Last Edit: February 22, 2011, 10:05:16 PM by rebecca »

Robyn

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Re: Another Switzer neg study published today?!
« Reply #6 on: February 22, 2011, 08:06:10 PM »
Well part of the problem is that Switzer never knew how to find it to begin with, and it looks like it could be PCR again.  But I think this shows it all from their abstract: (I guess if they try to stack up enough bogus studies they think they can make it go away like they did with Elaine DeFreitas).   Trouble is there are some real scientists still left out there working on it. So what will win out science or politics? That's the question.

"Our findings, together with previous negative reports, do not suggest an association of XMRV or MuLV in the majority of CFS cases".
« Last Edit: February 22, 2011, 08:16:22 PM by Robyn »
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hatshepsut

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Re: Another Switzer neg study published today?!
« Reply #7 on: February 22, 2011, 08:14:47 PM »
It looks like they have used the same clone that all the negative studys have. VP62 is a clone Judy Mikovits have talked about earlier in this letter to editor:
 http://www.iacfsme.org/BULLETINSPRING2010/Spring2010MikovitsLetter/tabid/427/Default.aspx

She said about VP62:
"However, if any of the last three are true, single round PCR of genomic DNA isolated from PBMCs, using primers based on published sequences from using highly specific PCR based on the sequence of a single molecular clone, (VP62) might not result in the amplification of XMRV, even from an infected individual."

From todays negative Switzer study:

Dilutions of DNA from XMRV-infected 22Rv1 human prostate carcinoma cells were used as positive
controls in this test [15]. 1.0 μg of DNA (333 ng of PBMC DNA) was used in the nested pol and gag PCR
tests at the CDC for which 1,000 and 10 copies of the XMRV(VP62) plasmid were used as positive
controls [1, 9]. A subset of 48 plasma samples were tested for viral RNA sequences by RT-PCR using
primers from the nested gag assay and also by using a new quantitative RT-PCR test that generically
detects MuLV and XMRV gag sequences. Both RT-PCR tests could detect between 10 – 25 copies of
XMRV (VP62) RNA.

Gerwyn

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Re: Another Switzer neg study published today?!
« Reply #8 on: February 22, 2011, 08:21:24 PM »


Danielson and others used the same assay and proved that it does not work


they used one assay based on env which could detect a integrated copy of a provirus which did detect the virus

they then tried to detect gag sequences in the the same patients using  an assay calibrated by being able to detect VP62 in a spiked sample and could not however much DNA was used

they could not any assay based on the POL gene to work because of competition with human DNA sequences

to complex for switzer to read I guess

Tango

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Re: Another Switzer neg study published today?!
« Reply #9 on: February 22, 2011, 08:23:17 PM »
Looks to me like the CDC is trying to get itself out of this mess.


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Some studies also used the same PCR assays as the initial study or generic tests for detecting both XMRV and other variants of MuLV [6-9]

No they did not!
"I suspect there have been a number of conspiracies that never were described or leaked out. But I suspect none of the magnitude and sweep of Watergate." Woodward

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subtr4ct

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Re: Another Switzer neg study published today?!
« Reply #10 on: February 22, 2011, 08:23:51 PM »
"Our findings, together with previous negative reports, do not suggest an association of XMRV or MuLV in the majority of CFS cases".

They're blowing hard on the quantity-trumps-quality horn.  Unfortunately it sounds like a kazoo
Disclaimer: I am not a medical doctor.  This post is not medical advice.  Consult your physician before taking any action.

Tango

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Re: Another Switzer neg study published today?!
« Reply #11 on: February 22, 2011, 08:30:25 PM »
Hey Switzer didn't contaminate his own lab.  Good on ya, you twerp!

What are they calling MuLV????


Quote
All CFS patients met the 1994 research case definition and specified a minimum of 6 months of post-exertional malaise and a high degree of disability, more closely resembling persons with CFS in the Lombardi et al. report than those CFS cases in previous studies. Specifically, we used Dr. Bell’s CFS severity scale as an indicator of the degree of disability [13].

No, I don't think they can say that.
« Last Edit: February 22, 2011, 08:35:27 PM by v99 »
"I suspect there have been a number of conspiracies that never were described or leaked out. But I suspect none of the magnitude and sweep of Watergate." Woodward

"I would favor any name that does not impose (or give the appearance of imposing) taxonomic preconceptions on the nomenclature." Coffin

bullybeef

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Re: Another Switzer neg study published today?!
« Reply #12 on: February 22, 2011, 08:43:50 PM »
Seems to me they're using the Noble Lie: http://en.wikipedia.org/wiki/Noble_lie

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In politics a noble lie is a myth or untruth, often, but not invariably, of a religious nature, knowingly told by an elite to maintain social harmony. The noble lie is a concept originated by Plato as described in The Republic. A noble lie, although it may benefit all parties, is different from a white lie since a white lie does not cause discord if uncovered whereas noble lies are usually of a nature such that they would do so.

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Dr. Yes

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Re: Another Switzer neg study published today?!
« Reply #13 on: February 22, 2011, 09:07:21 PM »
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Our findings, together with previous negative reports, do not suggest an association of XMRV or MuLV in the majority of CFS cases.

Actually...

Their findings -- taken together with the CDC's own results from the Blood Working Group, in which the CDC could not find virus using the assay from the original Switzer paper in clinical positives from both the WPI and the FDA, but DID find positives from similar clinical positives using TWO DIFFERENT PCR assays, and together with the findings by Danielson et al -- suggest that the assays and/or protocols employed in this study are incapable of detecting XMRV or other MRVs in CFS patient samples.
« Last Edit: February 22, 2011, 09:10:29 PM by Dr. Yes »
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Gerwyn

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Re: Another Switzer neg study published today?!
« Reply #14 on: February 22, 2011, 09:07:44 PM »

Ok here we go

the authors refer to the study by danielson et al 2010  because they referr to the authors conclusion that a minimum of 600ng of DNA was needed

they then dont say that using VP-62 to calibrate their PCR could neither find pol or GAG sequences in patients known to be infected

they then go on to use that failed method to set their PCR conditions

having said that they realised that the amount  of DNA was crucial they then decide to use an untried RT-PCR assay

to attempt to detect XMRV  IN  Plasma.Then to make sure they did not accidentally isolate XMRV

They isolated RNA from 62ul of plasma and use 0.25ul of cDNA in their RT assay.  The likelyhood of even one viral sequence being present was negligable

They then use a serology assay which has been shown to be 400% less sensitive than PCR in detecting XMRV antibodies in the blood of healthy people(qui et al)

God this stuff is getting totally predictable

the patients were recruited via an one line survey from primary care and there was no objective evidence that they had PEM .They were not assessed by a specialist physician nor did the patients satisfy the CCC criteria