Een mod/admin mag het het wel samenvoegen.
Ik ga het nog een keer goed bestuderen als ik me beter kan concentreren.
4 artikelen in Retrovirology tonen contaminatie XMRV aan
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magnetronnie
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4 artikelen in Retrovirology tonen contaminatie XMRV aan
Volgens Corts site is vooral het eerste artikel echt nieuw (Hue et al). Ben te moe voor geconcentreerd lezen en samenvatten, maar de draad op dat forum verklaart veel.
4 artikelen in Retrovirology tonen contaminatie XMRV aan
Raar dat men meteen vraagtekens stelt bij de link tussen XMRV en aandoeningen. Want, ook serologie toont toch antistoffen aan? Dit gaat toch alleen om PCR methoden (en die gebruik je toch niet bij serologie? of heb ik het fout?)
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Guido_den_Broeder
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4 artikelen in Retrovirology tonen contaminatie XMRV aan
Ik ben zeer benieuwd hoe men wil verklaren dat een contaminatie selectief alle monsters van de ME-patiënten vervuilt en maar een paar van de gezonde controles...
4 artikelen in Retrovirology tonen contaminatie XMRV aan
Goed punt Guido
Ik zal ook morgen ofzo nog even kijken of ik kan naslaan wat Alter hier vorige week bij de bespreking van de blood working group over heeft gezegd. Hij werd ook flink aangevallen door aanwezigen die wilde aantonen dat het allemaal contaminatie was, maar hield zich staande en is er van overtuigd dat dit niet het geval kan zijn.
Ben nu erg moe, maar ga morgen kijken of ik die argumenten van hem nog ergens kan vinden.
Overigens, natuurlijk is het belangrijk contaminatie uit te sluiten en moeten we zeker weten dat dit nooit het geval kan zijn, om te voorkomen dat straks patienten verkeerde uitslagen krijgen, maar dit is nu ook precies de zorg van de blood working group, daar zijn ze ook hard mee bezig.
Ik zal ook morgen ofzo nog even kijken of ik kan naslaan wat Alter hier vorige week bij de bespreking van de blood working group over heeft gezegd. Hij werd ook flink aangevallen door aanwezigen die wilde aantonen dat het allemaal contaminatie was, maar hield zich staande en is er van overtuigd dat dit niet het geval kan zijn.
Ben nu erg moe, maar ga morgen kijken of ik die argumenten van hem nog ergens kan vinden.
Overigens, natuurlijk is het belangrijk contaminatie uit te sluiten en moeten we zeker weten dat dit nooit het geval kan zijn, om te voorkomen dat straks patienten verkeerde uitslagen krijgen, maar dit is nu ook precies de zorg van de blood working group, daar zijn ze ook hard mee bezig.
Laatst gewijzigd door poppetje op 20 dec 2010, 20:43, 1 keer totaal gewijzigd.
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annemoontje
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Precies Guido! Dit is overigens wat Lo et al. (NIH/FDA study) in hun studie zeggen over evt. contaminatie. Lijkt me de beweringen van de 4 artikelen hierboven toch aardig overstemmen/ontkrachten..
"The Lo et al. study provides several arguments against the contamination claims. These include specific tests and steps that Lo et al. performed in order to rule out contamination.
1. Every sample in the Lo et al. study that tested MLV positive (based on gag gene sequences), was tested for traces of mouse DNA contamination. The PCR used in this MLV contamination test was designed so that it was more sensitive to registering mouse DNA than MLV gag sequences. It follow that if MLV by contamination was detected, mouse DNA would have also been detected. This PCR contamination test didn’t detect any mouse DNA in the reaction mixtures or clinical samples included in the study. Lo et al. concluded that this rules out the possibility of contamination by mouse DNA.
2. Lo et al. then assessed the likelihood that the clinical samples or assays used may have been contaminated. The blood samples used in this study were obtained from clinical laboratories that had never contained or worked with mice or retroviral vectors. The blood from these clinical samples was drawn from needles into empty vacuum tubes that were only opened for the blood drawing process. The Lo et al. laboratory in which the PCR tests were performed had also never worked with murine cells, murine blood samples or MLV vectors.
3. The MLV gag sequences that were detected in the study cohort’s blood comprised at least six distinct types of MLV sequence. Lo et al. hypothesise that if contamination is the mechanism behind results then the same sequences arise in most, if not all of the positive samples. The Lo et al. study also determined that these six plus sequences had “significant variations” when compared to all other known exogenous MLVs and viral vectors.
4. This Lo et al. study also set up 300 negative controls for the multiple PCR amplification aspect of the study. This step involved attempting to detect the MLV gag gene however all results were negative.
5. Lo et al. also strengthened their anti-contamination argument by obtaining fresh blood samples from 8 patients. These fresh samples were obtained approximately 15 years after the original drawing of the samples. Seven out of the eight patients still had MLV gag sequences detected. Lo et al. found that these newly obtained sequences were significantly varied from the original patient sequences. Lo et al. wrote that this “would be expected in retroviral infections, but not from contamination.”
Verder: The two lead study authors, Dr. Lo and Dr. Alter have publically made several statements emphasising their confidence in the result they obtained. Dr Alter made one of these comments to CFS Central, “There were no changes in the conclusions, but we added data that made the conclusions stronger…For one thing, we did some further work to feel confident that there was no contamination.” (Dr Alter is referring to the delay in publication of the Lo et al. study.) (http://www.cfscentral.com/2010/08/fdani ... thing.html)"
Als laatste is er getest op contaminatie door meerdere laboratoria, ook degenen die geen XMRV hebben kunnen vinden. Er is met verschillende pogingen te bewijzen dat het contaminatie zou zijn geen van alle gelukt contaminatie aan te tonen, nul noppes nada, 1vd vb-en: "all of the Lombardi et al. tests came back negative for contamination. Dr. Switzer, lead author of the CDC’s study that failed to detect XMRV/MLV designed his own contamination test that was performed on the Lombardi et al. samples. This test was a real time PCR assay that contained two fluorescent mouse mitochondria DNA specific probes. This test, created by Dr. Switzer failed to detect any signs of contamination amongst the Lombardi et al. samples."
Ik weet niet hoor, maar ongeacht wat ze in die artikelen precies beweren (wat ik dus niet kan volgen), contaminatie lijkt me toch niet heel waarschijnlijk als je dit ziet. Zouden ook alle laboratoria die sindsdien bij veel mensen XMRV/MLV hebben gevonden ook allemaal gecontamineerd zijn? Het lijkt mij toch echt wederom een sneue poging hun eigen onvermogen te verhullen door de succesvollen zwart te maken...
"The Lo et al. study provides several arguments against the contamination claims. These include specific tests and steps that Lo et al. performed in order to rule out contamination.
1. Every sample in the Lo et al. study that tested MLV positive (based on gag gene sequences), was tested for traces of mouse DNA contamination. The PCR used in this MLV contamination test was designed so that it was more sensitive to registering mouse DNA than MLV gag sequences. It follow that if MLV by contamination was detected, mouse DNA would have also been detected. This PCR contamination test didn’t detect any mouse DNA in the reaction mixtures or clinical samples included in the study. Lo et al. concluded that this rules out the possibility of contamination by mouse DNA.
2. Lo et al. then assessed the likelihood that the clinical samples or assays used may have been contaminated. The blood samples used in this study were obtained from clinical laboratories that had never contained or worked with mice or retroviral vectors. The blood from these clinical samples was drawn from needles into empty vacuum tubes that were only opened for the blood drawing process. The Lo et al. laboratory in which the PCR tests were performed had also never worked with murine cells, murine blood samples or MLV vectors.
3. The MLV gag sequences that were detected in the study cohort’s blood comprised at least six distinct types of MLV sequence. Lo et al. hypothesise that if contamination is the mechanism behind results then the same sequences arise in most, if not all of the positive samples. The Lo et al. study also determined that these six plus sequences had “significant variations” when compared to all other known exogenous MLVs and viral vectors.
4. This Lo et al. study also set up 300 negative controls for the multiple PCR amplification aspect of the study. This step involved attempting to detect the MLV gag gene however all results were negative.
5. Lo et al. also strengthened their anti-contamination argument by obtaining fresh blood samples from 8 patients. These fresh samples were obtained approximately 15 years after the original drawing of the samples. Seven out of the eight patients still had MLV gag sequences detected. Lo et al. found that these newly obtained sequences were significantly varied from the original patient sequences. Lo et al. wrote that this “would be expected in retroviral infections, but not from contamination.”
Verder: The two lead study authors, Dr. Lo and Dr. Alter have publically made several statements emphasising their confidence in the result they obtained. Dr Alter made one of these comments to CFS Central, “There were no changes in the conclusions, but we added data that made the conclusions stronger…For one thing, we did some further work to feel confident that there was no contamination.” (Dr Alter is referring to the delay in publication of the Lo et al. study.) (http://www.cfscentral.com/2010/08/fdani ... thing.html)"
Als laatste is er getest op contaminatie door meerdere laboratoria, ook degenen die geen XMRV hebben kunnen vinden. Er is met verschillende pogingen te bewijzen dat het contaminatie zou zijn geen van alle gelukt contaminatie aan te tonen, nul noppes nada, 1vd vb-en: "all of the Lombardi et al. tests came back negative for contamination. Dr. Switzer, lead author of the CDC’s study that failed to detect XMRV/MLV designed his own contamination test that was performed on the Lombardi et al. samples. This test was a real time PCR assay that contained two fluorescent mouse mitochondria DNA specific probes. This test, created by Dr. Switzer failed to detect any signs of contamination amongst the Lombardi et al. samples."
Ik weet niet hoor, maar ongeacht wat ze in die artikelen precies beweren (wat ik dus niet kan volgen), contaminatie lijkt me toch niet heel waarschijnlijk als je dit ziet. Zouden ook alle laboratoria die sindsdien bij veel mensen XMRV/MLV hebben gevonden ook allemaal gecontamineerd zijn? Het lijkt mij toch echt wederom een sneue poging hun eigen onvermogen te verhullen door de succesvollen zwart te maken...
Do what you feel in your heart to be right, for you'll be criticized anyway. Eleanor Roosevelt (1884-1962)
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@Guido, Dit is wat Ocean blue en Cort erover zeggen.
Originally Posted by oceanblue
As I understand it, Robert Weiss - arch-XMRV sceptic - argues that generally patient samples are handled more than negative controls that are often just water. The sample might be handled multiple times in collection, in storage, in retrieval (I think the WPI samples were frozen and drawn some time ago). And this is his explanation for why patient samples could end up with a higher positive rate than controls if contamination is the real cause. I think he's also saying that such different handling of samples and controls is quite common place, not just in the case of XMRV testing.
That is an interesting point that I had not thought of before because one thing we do know is that while some of those samples came up positive immediately Dr. Mikovits did say that they had to test others repeatedly before they came up positive - so they were handled more. We also know - it was reported both by Dr. Singh and at the BWG meeting - that nested PCR, which is what they used, is more prone to contamination because the procedure is done twice and at some point in the procedure the tubes are opened up or something like that.
Critics did point out that the WPI only tested the healthy control samples once while they tested some of the patient samples several times. This could have introduced bias in at least two ways; a) they searched harder for XMRV in the patient population and b) they, as was reported above, exposed the samples more.
I don't think (a) matters because no one has shown markedly higher levels of XMRV in the controls than the WPI did but b might.
Originally Posted by oceanblue
As I understand it, Robert Weiss - arch-XMRV sceptic - argues that generally patient samples are handled more than negative controls that are often just water. The sample might be handled multiple times in collection, in storage, in retrieval (I think the WPI samples were frozen and drawn some time ago). And this is his explanation for why patient samples could end up with a higher positive rate than controls if contamination is the real cause. I think he's also saying that such different handling of samples and controls is quite common place, not just in the case of XMRV testing.
That is an interesting point that I had not thought of before because one thing we do know is that while some of those samples came up positive immediately Dr. Mikovits did say that they had to test others repeatedly before they came up positive - so they were handled more. We also know - it was reported both by Dr. Singh and at the BWG meeting - that nested PCR, which is what they used, is more prone to contamination because the procedure is done twice and at some point in the procedure the tubes are opened up or something like that.
Critics did point out that the WPI only tested the healthy control samples once while they tested some of the patient samples several times. This could have introduced bias in at least two ways; a) they searched harder for XMRV in the patient population and b) they, as was reported above, exposed the samples more.
I don't think (a) matters because no one has shown markedly higher levels of XMRV in the controls than the WPI did but b might.
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annemoontje
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Daar is wat voor te zeggen idd Urania, punt b, maar nogmaals:
Dr. Switzer, lead author of the CDC’s study that failed to detect XMRV/MLV designed his own contamination test that was performed on the Lombardi et al. samples. This test was a real time PCR assay that contained two fluorescent mouse mitochondria DNA specific probes. This test, created by Dr. Switzer failed to detect any signs of contamination amongst the Lombardi et al. samples."
I rest my case..
Dr. Switzer, lead author of the CDC’s study that failed to detect XMRV/MLV designed his own contamination test that was performed on the Lombardi et al. samples. This test was a real time PCR assay that contained two fluorescent mouse mitochondria DNA specific probes. This test, created by Dr. Switzer failed to detect any signs of contamination amongst the Lombardi et al. samples."
I rest my case..
Do what you feel in your heart to be right, for you'll be criticized anyway. Eleanor Roosevelt (1884-1962)
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O maar annemoontje, ik ben absoluut niet aan het redeneren, veel te moe. Ik probeer een beetje informatie door te nemen en meer dan knippen/plakken kan ik niet. Ik hoop van harte dat je gelijk hebt.
@poppetje: Cort maakt een voor mij ondoorgrondelijke opmerking ove antibodies in een van de posts. Kijk naar 51-53 en dan weer vanaf 56 (als ik me goed herinner, mijn hoofd zit vol watten.
http://forums.aboutmecfs.org/showthread ... tion/page6
@poppetje: Cort maakt een voor mij ondoorgrondelijke opmerking ove antibodies in een van de posts. Kijk naar 51-53 en dan weer vanaf 56 (als ik me goed herinner, mijn hoofd zit vol watten.
http://forums.aboutmecfs.org/showthread ... tion/page6
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annemoontje
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Zo kwam het wel over he Urania? Sorry hoor, zo was het niet bedoeld.. Meer als reactie op wat Ocean Blue en Cort zeggen en dit door nog een keer te herhalen wat ik had gezegd, tevens door knip-en-plakwerk (ik heb soms de neiging gehoord te willen worden..).
).Do what you feel in your heart to be right, for you'll be criticized anyway. Eleanor Roosevelt (1884-1962)
ME & YOU, crowdfunding studie die ME op de medische kaart kan zetten! http://www.meyou.no/press-release-english/
ME & YOU, crowdfunding studie die ME op de medische kaart kan zetten! http://www.meyou.no/press-release-english/
Ik ben dol op een stevige discussie.. http://neuroskeptic.blogspot.com/2010/1 ... ounts.html
Uitleg van het onderzoek door een geïnformeerde leek, dus ietsje leesbaarder dan de teksten zelf, met aan het eind dezelfde vragen die hier ook zijn gesteld.
Uitleg van het onderzoek door een geïnformeerde leek, dus ietsje leesbaarder dan de teksten zelf, met aan het eind dezelfde vragen die hier ook zijn gesteld.
Cort is blijkbaar bezig met het analyserend samenvatten van de 4 artikelen (heeft de tweede al gepost). Dit betreft het belangrijkste artikel:
My take on the Hue paper - a very complex paper - reader beware; this is a laymen's take, of course, on a complicated issue.
WPI Demonstrates XMRV is Not a Contaminant - Demonstrating that XMRV was not likely to be a contaminant was an important of the Science paper. While the WPI was not able to conclusively prove this they provided enough convincing evidence for Science to publish the paper. This following is taken direct from the paper.
Sequences of full-length XMRV genomes from two CFS patients and a partial genome from a third patient were generated (table S1). CFS XMRV strains 1106 and 1178 each differed by six nucleotides (nt) from the reference prostate cancer strain XMRV VP2 (EF185282), and with the exception of one nt, the variant nucleotides mapped to different locations within the XMRV genome, suggesting independent infections. By comparison, prostate cancer-derived XMRV strains VP35 and VP42 differed from VP62 by 13 and 10 nt, respectively. Thus, the complete XMRV genomes in CFS patients are > 99% identical in sequence to those detected in patients with prostate cancer.
To exclude the possibility that we were detecting a murine leukemia virus (MLV) laboratory contaminant, we determined the phylogenetic relationship between endogenous (nonecotropic) MLV sequences, XMRV sequences, and sequences from CFS patients 1104, 1106 and 1178 (fig. S2). XMRV sequences from the CFS patients clustered with the XMRV sequences from prostate cancer cases and formed a distinct branch from nonecotropic MLVs common in cases of inbred mouse strains. Thus, the virus detected in the CFS patients’ blood samples is unlikely to be a contaminant.
Hue Proposes XMRV is a Contaminant - Now Hue has taken another, more comprehensive look at that question. He appears to have done much the same thing (?) but using more mouse strains.
Hue cloned and sequenced the gag and env genes from the prostate cancer cell line that produced the representative copy of XMRV. (This is the copy the WPI searched for in their initial paper.) Then he compared how closely those genes to those found in endogenous MLV genomes, some other XMRV clones, other MLV genomes and 2 samples from the WPI study.
The phylogenetic analysis suggested that, in contrast to the WPI’s findings, that everything, the XMRV from prostate cancer, the CFS patients, the endogenous MLV retrovirus, etc. grouped together; ie. they all appeared highly related to each other. Once XMRV passed into a human host it should developed its own group of viruses that cluster together; that is, in fact what the WPI’s analysis indicated. But Hues larger analysis did not - it suggested that have been no ‘outbreaks’, genetically speaking, of XMRV; instead of an XMRV branch and an endogenous MLV branch, etc. there was one big cluster.
Statistic Derivation of XMRV's origin - They then ran a Baynesian tree analysis that is designed to statistically determine which part of a group of elements is probably the origin of that group. Every one of 3000 passes of that tree suggested that the entire group was derived from a cell line; ie they are all derived from a laboratory construct.
Hue looked for XMRV’s distinctive genetic element - a deletion in the gag sequence - in 12 inbred mouse strains. The fact that he founded it in all of them suggested, I believe that they ALL carried ‘XMRV’ - a surprise in itself. He also found this ‘specific XMRV element’ in four endogenous retroviruses. Interestingly, it wasn't easy to find; it was only present in a very low-frequency - which is a little ominous because, as we know, XMRV is not easy to find.
Primers - When they looked at the primers used to screen for XMRV and he found that “primers sets as he described as XMRV specific can really amplify MLV sequences” that is, if you were to use those primers to search for XMRV in mice in which it is not found - they would tell you that XMRV was there. He seems to be stating that the specific gag deletion researchers are looking for does not necessarily pick up XMRV.
My take on the Hue paper - a very complex paper - reader beware; this is a laymen's take, of course, on a complicated issue.
WPI Demonstrates XMRV is Not a Contaminant - Demonstrating that XMRV was not likely to be a contaminant was an important of the Science paper. While the WPI was not able to conclusively prove this they provided enough convincing evidence for Science to publish the paper. This following is taken direct from the paper.
Sequences of full-length XMRV genomes from two CFS patients and a partial genome from a third patient were generated (table S1). CFS XMRV strains 1106 and 1178 each differed by six nucleotides (nt) from the reference prostate cancer strain XMRV VP2 (EF185282), and with the exception of one nt, the variant nucleotides mapped to different locations within the XMRV genome, suggesting independent infections. By comparison, prostate cancer-derived XMRV strains VP35 and VP42 differed from VP62 by 13 and 10 nt, respectively. Thus, the complete XMRV genomes in CFS patients are > 99% identical in sequence to those detected in patients with prostate cancer.
To exclude the possibility that we were detecting a murine leukemia virus (MLV) laboratory contaminant, we determined the phylogenetic relationship between endogenous (nonecotropic) MLV sequences, XMRV sequences, and sequences from CFS patients 1104, 1106 and 1178 (fig. S2). XMRV sequences from the CFS patients clustered with the XMRV sequences from prostate cancer cases and formed a distinct branch from nonecotropic MLVs common in cases of inbred mouse strains. Thus, the virus detected in the CFS patients’ blood samples is unlikely to be a contaminant.
Hue Proposes XMRV is a Contaminant - Now Hue has taken another, more comprehensive look at that question. He appears to have done much the same thing (?) but using more mouse strains.
Hue cloned and sequenced the gag and env genes from the prostate cancer cell line that produced the representative copy of XMRV. (This is the copy the WPI searched for in their initial paper.) Then he compared how closely those genes to those found in endogenous MLV genomes, some other XMRV clones, other MLV genomes and 2 samples from the WPI study.
The phylogenetic analysis suggested that, in contrast to the WPI’s findings, that everything, the XMRV from prostate cancer, the CFS patients, the endogenous MLV retrovirus, etc. grouped together; ie. they all appeared highly related to each other. Once XMRV passed into a human host it should developed its own group of viruses that cluster together; that is, in fact what the WPI’s analysis indicated. But Hues larger analysis did not - it suggested that have been no ‘outbreaks’, genetically speaking, of XMRV; instead of an XMRV branch and an endogenous MLV branch, etc. there was one big cluster.
Statistic Derivation of XMRV's origin - They then ran a Baynesian tree analysis that is designed to statistically determine which part of a group of elements is probably the origin of that group. Every one of 3000 passes of that tree suggested that the entire group was derived from a cell line; ie they are all derived from a laboratory construct.
Hue looked for XMRV’s distinctive genetic element - a deletion in the gag sequence - in 12 inbred mouse strains. The fact that he founded it in all of them suggested, I believe that they ALL carried ‘XMRV’ - a surprise in itself. He also found this ‘specific XMRV element’ in four endogenous retroviruses. Interestingly, it wasn't easy to find; it was only present in a very low-frequency - which is a little ominous because, as we know, XMRV is not easy to find.
Primers - When they looked at the primers used to screen for XMRV and he found that “primers sets as he described as XMRV specific can really amplify MLV sequences” that is, if you were to use those primers to search for XMRV in mice in which it is not found - they would tell you that XMRV was there. He seems to be stating that the specific gag deletion researchers are looking for does not necessarily pick up XMRV.
CGT helpt! - ook tegen contaminatie-denkbeelden.
Contaminatie speelde volgens mij al tijdens de Bijlmeraffaire toen Jos v.d. M. niets wilde weten van mycoplasma. Later wilde Jos niets weten van XMRV en weer was er sprake van contaminatie. Ongetwijfeld speelde dit ook bij het onderzoek van De Freitas (?) Heel toevallig overkomt het Mikovits, Lo en Alter en wellicht ook Singh. En het overkomt ook Hanson, de Merleir, Cheney, Can Ruti en de Noorse onderzoekers (Hillestrom clinic).
Contaminatie is, laten daar geen twijfel over laten bestaan, in de mode. De instandhoudende factor is bekend, maar er is hoop CGT helpt!, ook tegen contaminatie-denkbeelden.
Contaminatie is, laten daar geen twijfel over laten bestaan, in de mode. De instandhoudende factor is bekend, maar er is hoop CGT helpt!, ook tegen contaminatie-denkbeelden.
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annemoontje
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Contaminatie lijkt idd het favoriete wapen tegen ongewenste ontdekkingen American, wat helaas nog niet zegt dat het onmogelijk is. Ik was heel stellig in dat het onzin was, maar ben er niet (meer) 100% zeker van. Niets is zeker zolang alleen het contaminatiekamp van zich heeft laten horen en dit niet overtuigend is weerlegd. WPI, Lo&Alter, Singh enz. kunnen dit enkel doen, maar dit kan nog even duren ivm feestdagen. Ik ben ontzettend benieuwd.
Ik heb net voor mezelf nav wat ik gisteren (of eerder) heb gelezen hierover (vooral van mensen die vlgns mij genoeg wetenschappelijke kennis hebben) dmv weer effe checken wat erover gezegd is een overzichtje gemaakt.
Punten die contaminatie onwaarschijnlijk (zouden) maken:
-antilichamen gevonden; door iemand werd gezegd dat het menselijk lichaam geen antilichamen aan kan maken tegen een contaminant (ik weet niet of dit echt zo is, weet nl. niet of de persoon van deze opmerking voldoende wetensch. kennis heeft om dit op waarde te kunnen schatten)
-de afwijkingen die op grote schaal gevonden worden bij ME/CVS- patiënten die eng veel overeenkomen met die van symptomatische HIV-patiënten (wat overigens nog kan betekenen dat het om een ander retrovirus zou kunnen gaan of dat een retrovirus daarvoor niet nodig is?)
-contaminatie bij PCR schijnt vaker voor te komen, is zeker niet onmogelijk, maar bij co-cultuur zou dit argument niet meer opgaan (of dit waar is weet ik niet)
-mensen die in USA en Europa positief zijn getest op zowel XMRV als MLV, allemaal gevolg van contaminatie? Lijkt mij (als leek althans) niet waarschijnlijk.
-!!! Tijdens de blood working group zie Alter: “They tested the old samples and did new draws and found the same gene sequences which leads to the question how do you get the same contaminant twice 15 years apart? What are the chances of that? They are using different reagants, different sampling techniques, maybe different tubes, they are processing the sample immediately - yet the same contaminant shows up.....That would be incredible.”
-!!! Mikovits heeft een UK-study gedaan (krijgt het helaas niet gepubliceerd..): They shipped samples to the National Cancer Institute, which, of course, has - impeccable credentials and they used a lab there that had never tested for XMRV. They also used two independent labs and everything was blinded. They cultured the samples for from three to six weeks, far longer than other studies have tried….. It was a great cohort, all Canadian Criteria, 50% homebound…if XMRV was going to show up in any patients it was going to show up in these - and it did - 78% were positive for XMRV and 4% of controls (as in the first study).
Punten die contaminatie niet uitsluiten:
-mensen die negatief testen op serologie en positief op co-cultuur.. Andersom is logisch, dit niet (toch?), tenzij antilichamen te moeilijk te vinden zijn waardoor het makkelijk kan voorkomen dat ze gemist worden. Dan zou een gevoeligere test nodig zijn.
-contaminatie zou al lang voor de onderzoeken hebben plaatsgevonden (waar dat in zou hebben gezeten weet ik zo niet meer, kan het niet zo gauw terugvinden)
-er is nog altijd geen compleet virus gevonden, alleen gedeelten, een heel virus zou heel overtuigend zijn. Of het contaminatie helemaal zou weerspreken begrijp ik er nog niet uit.
-behalve door het WPI wordt geen XMRV gevonden, vooral PMLV's (Lo&Alter en Hansen) en deze moeten volgens de contaminatiekampers toch echt muis-DNA zijn (al schijnen XMLV's de meest voorkomende muisvirussen zijn en niet PMLV's)
-Alter/Lo moeten nog een virus isoleren of bewijzen dat het ingebed is in menselijk DNA
-XMRV zou extreem veel lijken op (bepaald?) muis-DNA (oid) en kan dus ten onrechte als XMRV gezien worden
Mijn info heb ik oa van een verslag Blood Working Group van vorige week
Ik heb net voor mezelf nav wat ik gisteren (of eerder) heb gelezen hierover (vooral van mensen die vlgns mij genoeg wetenschappelijke kennis hebben) dmv weer effe checken wat erover gezegd is een overzichtje gemaakt.
Punten die contaminatie onwaarschijnlijk (zouden) maken:
-antilichamen gevonden; door iemand werd gezegd dat het menselijk lichaam geen antilichamen aan kan maken tegen een contaminant (ik weet niet of dit echt zo is, weet nl. niet of de persoon van deze opmerking voldoende wetensch. kennis heeft om dit op waarde te kunnen schatten)
-de afwijkingen die op grote schaal gevonden worden bij ME/CVS- patiënten die eng veel overeenkomen met die van symptomatische HIV-patiënten (wat overigens nog kan betekenen dat het om een ander retrovirus zou kunnen gaan of dat een retrovirus daarvoor niet nodig is?)
-contaminatie bij PCR schijnt vaker voor te komen, is zeker niet onmogelijk, maar bij co-cultuur zou dit argument niet meer opgaan (of dit waar is weet ik niet)
-mensen die in USA en Europa positief zijn getest op zowel XMRV als MLV, allemaal gevolg van contaminatie? Lijkt mij (als leek althans) niet waarschijnlijk.
-!!! Tijdens de blood working group zie Alter: “They tested the old samples and did new draws and found the same gene sequences which leads to the question how do you get the same contaminant twice 15 years apart? What are the chances of that? They are using different reagants, different sampling techniques, maybe different tubes, they are processing the sample immediately - yet the same contaminant shows up.....That would be incredible.”
-!!! Mikovits heeft een UK-study gedaan (krijgt het helaas niet gepubliceerd..): They shipped samples to the National Cancer Institute, which, of course, has - impeccable credentials and they used a lab there that had never tested for XMRV. They also used two independent labs and everything was blinded. They cultured the samples for from three to six weeks, far longer than other studies have tried….. It was a great cohort, all Canadian Criteria, 50% homebound…if XMRV was going to show up in any patients it was going to show up in these - and it did - 78% were positive for XMRV and 4% of controls (as in the first study).
Punten die contaminatie niet uitsluiten:
-mensen die negatief testen op serologie en positief op co-cultuur.. Andersom is logisch, dit niet (toch?), tenzij antilichamen te moeilijk te vinden zijn waardoor het makkelijk kan voorkomen dat ze gemist worden. Dan zou een gevoeligere test nodig zijn.
-contaminatie zou al lang voor de onderzoeken hebben plaatsgevonden (waar dat in zou hebben gezeten weet ik zo niet meer, kan het niet zo gauw terugvinden)
-er is nog altijd geen compleet virus gevonden, alleen gedeelten, een heel virus zou heel overtuigend zijn. Of het contaminatie helemaal zou weerspreken begrijp ik er nog niet uit.
-behalve door het WPI wordt geen XMRV gevonden, vooral PMLV's (Lo&Alter en Hansen) en deze moeten volgens de contaminatiekampers toch echt muis-DNA zijn (al schijnen XMLV's de meest voorkomende muisvirussen zijn en niet PMLV's)
-Alter/Lo moeten nog een virus isoleren of bewijzen dat het ingebed is in menselijk DNA
-XMRV zou extreem veel lijken op (bepaald?) muis-DNA (oid) en kan dus ten onrechte als XMRV gezien worden
Mijn info heb ik oa van een verslag Blood Working Group van vorige week
Do what you feel in your heart to be right, for you'll be criticized anyway. Eleanor Roosevelt (1884-1962)
ME & YOU, crowdfunding studie die ME op de medische kaart kan zetten! http://www.meyou.no/press-release-english/
ME & YOU, crowdfunding studie die ME op de medische kaart kan zetten! http://www.meyou.no/press-release-english/