I also made a big point about different cohorts.
I am not convinced about that at all, but if it is true you can respectfully point them out.That would be fine leaves, but he has a certain knack for making "errors" that undermine Mikovits and the WPI
Although three MLVs were found one MLV dominated the rest, infecting 86% of the CFS patients. One of the MLVs was found also in one healthy control. They are talking about gag gene sequences.
What is going with XMRV itself is not as important as it was before the Alter paper
Are you kidding?
While the WPIs overall thesis was confirmed we still have two disparate findings; the WPI found XMRV and no other MLVs while the Lo/Alter group found no XMRV and several other MLVs. Researchers abhor impasses like this and they must eventually be cleared up. That the virus is exceedingly tricky is clear.
you just don't get it, do you
Its possible but hardly likely that both findings are correct. Its more likely, I would guess, based on the swarm thesis, that the problem lies with the WPI findings rather than Dr. Alters.
Wow!!!! Both findings are likely correct. Alter has completely vindicated the WPI, what are you trying to do Cort? This is way out of order.
Dr. Lo in the Press Conference did not say anything about this - and neither did the FDA response which I noted was what I was referring to. Dr. Alter repeatedly referred to the fact that CFS is a spectrum disorder."Indeed, it is possible that the PCR primers used in various studies may have different sensitivity in detecting the diverse group of MLV-related virus gag gene sequences that we found in the clinical samples. The 5′ gag leader sequence of previously described XMRVs represents the most divergent segment of the XMRV genome in comparison with the genomes of the other MLVs (4). In particular, there is evidently a unique 15-nt deletion in the 5′ gag leader region in all of the XMRVs previously identified in patients with prostate cancer and CFS (3, 4). To detect XMRVs in human samples with better sensitivity and specificity, some studies used a PCR primer spanning this unique deletion as the “XMRV-specific” primer (6). However, none of the viral gag gene sequences amplified from the blood samples of CFS patients and blood donors in our study has this particular deletion (Fig. S1). As a consequence, such primers might have been insensitive in detecting the MLV-related gag gene sequences that we have identified." Lo et al.
However you have a good point. My thought was that sample preparation was a simple factor but it turns out that its not. In any case I am committed to getting to the bottom of this.10. How are the differences between the CDC and FDA study results being evaluated?
Differences in the results could reflect differences in the patient populations that provided the samples. Alternatively, undefined differences in the method of sample preparation could be contributing to the discordant test results. All of the scientists involved are working collaboratively to design experiments to quickly answer this scientifically puzzling question. An independent investigator at the National Heart, Lung, and Blood Institute (NHLBI) set up a test set of 36 samples, including known positives and presumed negatives. Both the FDA/NIH and CDC labs participated in this test, and the results showed that both labs were able to detect XMRV present at low levels in blinded samples. Additionally, the CDC laboratory provided 82 samples from their published negative study to FDA, who tested the samples blindly. Initial analysis shows that the FDA test results are generally consistent with CDC, with no XMRV-positive results in the CFS samples CDC provided (34 samples were tested, 31 were negative, 3 were indeterminate).
Fine. A critical point......
The Alter/Lo group did not do that, citing the difficulty of having to wade through from hundreds to 1,000’s of cells in order to find the one infected with MLV’s. (Yes, it is very rare in the blood!).
That's is not accurate. I cannot find the source right now, but that makes them sound lazy. They only believed that there was no reason to delay the paper.
I didn't say it didn't. Where did I say that?This study was a big breakthrough. It demonstrates that there are most likely problems with the other studies
Basically it comes down to this:
all the CDC patients in the Switzer et al study are empiric criteria patients. Within any study that uses the empiric criteria, there may well be patients who satisfy the Fukuda criteria. But patients were chosen using the empiric criteria.
I think it's quite possible that the cohort was the issue with the CDC study. Indeed we have the statement that the FDA team (Lo etc) couldn't find XMRV/MLVs in the samples from that study: http://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/ucm223232.htmYes, but you said the problem was not the methods.
And the problem WAS in large part the methods because if their methods had been good, they would not have found NOTHING.
10. How are the differences between the CDC and FDA study results being evaluated?
Differences in the results could reflect differences in the patient populations that provided the samples. Alternatively, undefined differences in the method of sample preparation could be contributing to the discordant test results. All of the scientists involved are working collaboratively to design experiments to quickly answer this scientifically puzzling question. An independent investigator at the National Heart, Lung, and Blood Institute (NHLBI) set up a test set of 36 samples, including known positives and presumed negatives. Both the FDA/NIH and CDC labs participated in this test, and the results showed that both labs were able to detect XMRV present at low levels in blinded samples. Additionally, the CDC laboratory provided 82 samples from their published negative study to FDA, who tested the samples blindly. Initial analysis shows that the FDA test results are generally consistent with CDC, with no XMRV-positive results in the CFS samples CDC provided (34 samples were tested, 31 were negative, 3 were indeterminate).
Disagree. I would like to point out that Cort has made some objective observations that make sense. Maybe you don't agree with all of them, or they are not what you want them to be, but his analysis makes sense based on the limited knowledge we actually have.
I think it's quite possible that the cohort was the issue with the CDC study. Indeed we have the statement that the FDA team (Lo etc) couldn't find XMRV/MLVs in the samples from that study: http://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/ucm223232.htm
I'm exactly sure what you are saying.My question is how much does it matter?They picked patients then that met both the empiric and the Fukuda criteria. Everyone on this board probably meets the Empirical criteria and the Fukuda criteria and the Canadian criteria. So long as they had Fukuda patients in that subset (which, as I pointed out is not necessarily true) then the fact that they almost met a weaker criteria is not that relevant to me.
http://www.forums.aboutmecfs.org/sh...-Paper-Arrives&p=115948&viewfull=1#post115948 - I praised and thanked you, etc.Some of the CDC samples also came from people meeting the Empirical definition which increased prevalence rates dramatically and ushered in a new breed of ‘CFS’ patient.
They found gag gene sequences, not more than that as you imply.Although three MLVs were found one MLV dominated the rest, infecting 86% of the CFS patients. One of the MLVs was found also in one healthy control.
What is going with XMRV itself is not as important as it was before the Alter paper
They found sequences, they would not have been looking if it were not for the 'Science' paper. You are jumping to conclusions about XMRV. It will most likely be found to also be mutating. You haven't thought this through. They also found three different types of MLV-related virus gag gene sequences in patients, and one in a control. XMRV is then another relative. That makes 5No, not at all. Since they have now found 4 MLV's one of which is XMRV - then the singular fact that XMRV is present is not as important as it was before the paper. The most salient fact is that there are a swarm of MLV's present in CFS. Which part of that don't you get?
While the WPIs overall thesis was confirmed we still have two disparate findings; the WPI found XMRV and no other MLVs while the Lo/Alter group found no XMRV and several other MLVs. Researchers abhor impasses like this and they must eventually be cleared up. That the virus is exceedingly tricky is clear.
Well firstly Harvey Alter disagrees with that. He says they are not 'disparate findings'. The finding of other MLV sequences supports the finding of XMRV. It's that simple. It all fits, if they are mutating.I don't V99 - those are the facts. Did Alter find XMRV? No.......Does that mean that at some point the two findings have to be reconciled? Yes, do you disagree with that? (How can you disagree with that??)
Its possible but hardly likely that both findings are correct. Its more likely, I would guess, based on the swarm thesis, that the problem lies with the WPI findings rather than Dr. Alters.
Again I will direct you to Alter & Lo's comments. How on earth would finding similar MLV sequences rub out the existence of XMRV? because that is what you are saying. I'm saying what they have been saying, that they are finding them also. Cort, what problem are you talking about? There is no problem. Both studies back each other up. You have no idea what you are talking about. Your making it up.I almost feel like we are different planets reading different papers. Are you saying that the WPI group does not have other MLV's in it? And that the ALter group does not have XMRV? Actually I will change that sentence to the problem probably lies in both groups. XMrV and MLV's are probably present in both groups. A complete vindication would be Alter findings XMRV in his samples. That would have set the research world afire. We'll know when that happens.
I don't know if I can bear to read the rest of it. I wouldn suggest you don't bother ever again. You are doing a disservice to every patient with the disease by posting nonsense like this.
The FDA response did not, interestingly, suggest that they believed other problems with methodology played a role.
The genetic sequences Lo and Alter looked for were the same as the genetic sequences that all the other studies looked for. The Lombardi (WPI), Groom, McClure and Switzer (CDC) papers all looked for gag sequences identified by primer #s 419F/1154R. (Dr. Racaniello noted that everyone had tried to duplicate the WPIs results by looking for the same sequence and they did.)
No, if you read the sentence I am clearly saying that you are misleading people into thinking that these were replication studies, and you should have expanded on this to explain why the method employed can still be wrong.I didn't make the statement that they are looking at the same genetic sequence
Yes they did, here:
"Indeed, it is possible that the PCR primers used in various studies may have different sensitivity in detecting the diverse group of MLV-related virus gag gene sequences that we found in the clinical samples. The 5′ gag leader sequence of previously described XMRVs represents the most divergent segment of the XMRV genome in comparison with the genomes of the other MLVs (4). In particular, there is evidently a unique 15-nt deletion in the 5′ gag leader region in all of the XMRVs previously identified in patients with prostate cancer and CFS (3, 4). To detect XMRVs in human samples with better sensitivity and specificity, some studies used a PCR primer spanning this unique deletion as the “XMRV-specific” primer (6). However, none of the viral gag gene sequences amplified from the blood samples of CFS patients and blood donors in our study has this particular deletion (Fig. S1). As a consequence, such primers might have been insensitive in detecting the MLV-related gag gene sequences that we have identified." Lo et al.
Dr. Lo in the Press Conference did not say anything about this - and neither did the FDA response which I noted was what I was referring to. Dr. Alter repeatedly referred to the fact that CFS is a spectrum disorder.
If something has a 1% chance of happening, the chances of it not happening in 104 goes is (.99)^104=0.3516.I agree that cohort was a big part of the problem, but the methods were also bad. Cohort definition had nothing to do wih finding ZERO in their controls, when we now have peer reviewed papers showing a possible prevalence of 1.7% in Japan, almost 3% in Northern Germany, the WPI's 4% and Alter's 6.8%. If their methods had been good, they would have found something.
I put the following:
You replied
That's because it is from the PNAS paper, Lo et al. The one you should have read.
They also found 4 MLV's, not 3, and even that is misleading
You're the one that's interpreting that as "lazy'. I interpret that as having not enough time - and it is accurate.
And are now saying:This study was a big breakthrough. It demonstrates that there are most likely problems with the other studies
Do you even remember what you have read? or copied?I didn't say it didn't. Where did I say that?
Well, excuse me. You always have the opportunity to write the right paper.
They found gag gene sequences, not more than that as you imply.
They found sequences, they would not have been looking if it were not for the 'Science' paper. You are jumping to conclusions about XMRV. It will most likely be found to also be mutating. You haven't thought this through. They also found three different types of MLV-related virus gag gene sequences in patients, and one in a control. XMRV is then another relative. That makes 5
Well firstly Harvey Alter disagrees with that. He says they are not 'disparate findings'. The finding of other MLV sequences supports the finding of XMRV. It's that simple. It all fits, if they are mutating.
Again I will direct you to Alter & Lo's comments. How on earth would finding similar MLV sequences rub out the existence of XMRV? because that is what you are saying. I'm saying what they have been saying, that they are finding them also. Cort, what problem are you talking about? There is no problem. Both studies back each other up. You have no idea what you are talking about. Your making it up
No, if you read the sentence I am clearly saying that you are misleading people into thinking that these were replication studies, and you should have expanded on this to explain why the method employed can still be wrong.
So????They found sequences, they would not have been looking if it were not for the 'Science' paper.
They obviously did not confirm the presence of XMRV....If they didn't do that do you suggest that I act as if they did?They did in the most important sense; the Alter/Lo study (Lo was the principal investigator) confirmed the major finding of the original Science paper- that retroviruses are highly prevalent in people with CFS and are found in much lower levels of the general population. After all the zeros and null findings of the previous studies, the Alter findings were remarkably consistent with the WPI's original findings (86% of CFS patients vs 68% and 7% of controls vs 4%). The fact that two accomplished researchers using their own samples and their own techniques duplicated the finding of mouse retroviruses in chronic fatigue syndrome was enormously beneficial.
No, if you read the sentence I am clearly saying that you are misleading people into thinking that these were replication studies, and you should have expanded on this to explain why the method employed can still be wrong.
The genetic sequences Lo and Alter looked for were the same as the genetic sequences that all the other studies looked for. The Lombardi (WPI), Groom, McClure and Switzer (CDC) papers all looked for ‘gag’ sequences identified by primer #’s 419F/1154R. (Dr. Racaniello noted that everyone had tried to duplicate the WPI’s results by looking for the same sequence and they did.)