In een zojuist in Science Express gepubliceerde brief stellen Silverman en Gupta dat een aantal van de monsters uit de originele XMRV CVS studie uit 2009 besmet zijn geweest. Ze trekken daarmee een deel van de originele studie in. De brief is mede ondertekend door de overige auteurs, waaronder Lombardi en Mikovitz.
http://www.sciencemag.org/content/early ... ce.1212182
Een andere studie zal ook vandaag in Science Express verschijnen en als ik het goed begrijp is die onderdeel van de Phase III van de Blood Working Group studie.
Slechts twee van de negen deelnemende laboratoria vonden XMRV, maar de resultaten kwamen niet overeen.
http://www.washingtonpost.com/blogs/the ... _blog.html
Science Express - einde XMRV?
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magnetronnie
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magnetronnie
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Science Express - einde XMRV?
Live chat nu @ http://news.sciencemag.org/sciencenow/2 ... yndro.html
Hier is de studie van de Blood Working Group:
http://www.sciencemag.org/content/early ... 1.abstract
Hier is de studie van de Blood Working Group:
http://www.sciencemag.org/content/early ... 1.abstract
En ze hebben al geantwoord;
Comment From Phil
Can't they just send blinded and mixed bloodsamples (of CFS patients and healthy people) to the WPI and see if they are able to make the distinction? Seems the easiest way to know wether XMRV is related to CFS or not.
3:18
Dr. Michael Busch:
Our study published today did involve sending blinded panels of different blood sample types (plasma, PBMC, whole blood) derived from CFS patients previously reported as XMTV/P-MLV infected to the WPI laboratory. The results inidcated their assays were inconsistent and, based on ther overall study, were false positive results.
3:19
Martin Enserink:
In other words, Phil, the Blood Working Group did what you suggested.
Comment From Phil
Can't they just send blinded and mixed bloodsamples (of CFS patients and healthy people) to the WPI and see if they are able to make the distinction? Seems the easiest way to know wether XMRV is related to CFS or not.
3:18
Dr. Michael Busch:
Our study published today did involve sending blinded panels of different blood sample types (plasma, PBMC, whole blood) derived from CFS patients previously reported as XMTV/P-MLV infected to the WPI laboratory. The results inidcated their assays were inconsistent and, based on ther overall study, were false positive results.
3:19
Martin Enserink:
In other words, Phil, the Blood Working Group did what you suggested.
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magnetronnie
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Uit de chat:
"Dr. Michael Busch:
I respect Judy, who I have met numerous times, for participating in the design and conduct of the SRWG studies including the blinded panel study just reported. She agreed with the findings and conclusions, but has argued that there are other interpretations, such as clearance of the virus or latency in tissues. This does not explain the results from her lab showing similar or higher rates of positive results in pedigreed controls vs previously positive patients replicate samples. Judy shoudl certainly continue her work on CFS/ME as well as gamma retroviruses."
Oftewel Mikovits is het eens met het resultaat van de BWG, maar gelooft nog altijd dat XMRV een rol speelt in CVS en gaat door met haar onderzoeken.
"Dr. Michael Busch:
I respect Judy, who I have met numerous times, for participating in the design and conduct of the SRWG studies including the blinded panel study just reported. She agreed with the findings and conclusions, but has argued that there are other interpretations, such as clearance of the virus or latency in tissues. This does not explain the results from her lab showing similar or higher rates of positive results in pedigreed controls vs previously positive patients replicate samples. Judy shoudl certainly continue her work on CFS/ME as well as gamma retroviruses."
Oftewel Mikovits is het eens met het resultaat van de BWG, maar gelooft nog altijd dat XMRV een rol speelt in CVS en gaat door met haar onderzoeken.
The paper published today in Science titled, “Failure to confirm XMRV/MLVs in the blood of patients with chronic fatigue syndrome: A multi-laboratory study,” by Simmons et al., finishes the work of the SRWG. Nine independent laboratories (see figure at right) using 19 optimized and highly sensitive assays were unable to reproducibly detect XMRV or MLVs in the coded panel of samples. The coded panel consisted of blood samples from five CFS patients who were positive for P-MLVs as described in the Lo et al. paper and 10 CFS patients recruited by the WPI who had previously tested positive for XMRV by at least one of a variety of test methods. Samples from six of these CFS patients were also used in the original study published in Science in 2009. The study design as described in Transfusion called for a larger panel of 30 previously-positive CFS subjects; however, Simmons et al., note that this smaller group was, “the maximum number of subjects who could be recruited by the cohort investigators.”
As noted above, the coded panel included pedigreed negative controls collected from three laboratory personnel and 12 local blood donors from Blood Centers of the Pacific, San Francisco. These negative control blood samples were processed into various blood components needed for the assays and distributed to participating laboratories for XMRV/MLV. All participating laboratories were in unanimous agreement that these controls were pedigreed negative. Finally, three experimental positive controls were prepared by spiking samples with cells or viral RNA from 22Rv1 cells to serve as an XMRV positive controls. All samples were coded and included as duplicates or triplicates in the panel.
Samples were collected, processed and prepared under stringently controlled, identical procedures. Sources of contamination of supplies and materials were carefully eliminated. All of the samples were coded and tested under blinded conditions, meaning that the laboratory personal doing the tests did not know whether they were testing samples from CFS patients, blood donors, pedigreed negatives or spiked positive controls. Each of the laboratories was able to define the assays it used to test samples. In total, there were 19 different assays used that fell into three categories: polymerase chain reaction (PCR), antibody reactivity and culture. The WPI has stated that culture is its most sensitive means of detecting XMRV and other gammaretroviruses; however, a laboratory problem with mycoplasma contamination prevented it from testing samples using this method. Dr. Francis Ruscetti’s lab at the National Cancer Institute (NCI) and Dr. Indira Hewlett’s lab at the Food and Drug Administration (FDA) used methods identical to WPI, as described in the supporting materials for the study.
Phase III results: red indicates positive results; orange reflects indeterminate results
The labs completed their work, submitted results and the code was broken by staff at the Blood Systems Research Institute in August. Only two of the nine laboratories, the WPI and Dr. Francis W. Ruscetti’s laboratory at the NCI, detected XMRV/MLV in any of the clinical samples contained in the coded panel. The remaining seven laboratories, including Dr. Lo’s FDA lab, only detected XMRV/MLV in the spiked positive controls, each with high accuracy. Only the WPI detected XMRV/MLVs in the CFS samples using PCR assays. The WPI assays were the least sensitive for detecting viral RNA as illustrated by the inability to detect RNA in 2 of 5 spiked plasma samples and 1 of 5 PBMC-spiked samples. The WPI and NCI/Ruscetti laboratories detected XMRV/MLVs at the same rate in CFS patient samples as in healthy blood donor samples. Further, even though each sample was represented in duplicate or triplicate, WPI and NCI/Ruscetti frequently only detected XMRV/MLVs in one of the duplicate or triplicate samples from the same subject. Sequence analysis of DNA amplified from the positive assays showed a high degree of similarity to XMRV derived from 22Rv1. Mouse DNA contamination was not found in any of the positive samples. Using the kappa coefficient as a statistical measure of agreement, it was found that even though both WPI and NCI/Ruscetti detected XMRV/MLV in some of the samples, the samples that were positive were often different samples, indicating there was no agreement on what could be called an XMRV/MLV positive sample.
The conclusion of this nearly two-year study is that XMRV/P-MLVs are not reproducibly detected in clinical samples (15 from individuals who had previously tested positive) using current, state-of-the art assays. The authors state, “our findings are reassuring with respect to blood safety and indicate that routine blood donor screening for XMRV/P-MLV is not warranted at this time.” Phase IV will not proceed, although there are results from studies of large numbers of blood donor samples pending publication.
With this closing statement, it appears that the blood safety community is satisfied with the scientific rigor of the SRWG study and that XMRV/P-MLVs are not a threat to the blood supply. It is remarkable to see this type of study done with government, commercial and private laboratories working in parallel to address a potentially serious public health issue. Even though the SRWG studied was designed as a blood safety study, it helped bring CFS into the light. Many of investigators on the SRWG previously knew little about CFS. Now they are familiar with the enormous suffering that CFS inflicts, the problems with the CFS case definition for research and the anger and passion that comes with an illness that has so long been in the dark shadows, unsolved.
bron: http://www.research1st.com/2011/09/22/study-summaries/
As noted above, the coded panel included pedigreed negative controls collected from three laboratory personnel and 12 local blood donors from Blood Centers of the Pacific, San Francisco. These negative control blood samples were processed into various blood components needed for the assays and distributed to participating laboratories for XMRV/MLV. All participating laboratories were in unanimous agreement that these controls were pedigreed negative. Finally, three experimental positive controls were prepared by spiking samples with cells or viral RNA from 22Rv1 cells to serve as an XMRV positive controls. All samples were coded and included as duplicates or triplicates in the panel.
Samples were collected, processed and prepared under stringently controlled, identical procedures. Sources of contamination of supplies and materials were carefully eliminated. All of the samples were coded and tested under blinded conditions, meaning that the laboratory personal doing the tests did not know whether they were testing samples from CFS patients, blood donors, pedigreed negatives or spiked positive controls. Each of the laboratories was able to define the assays it used to test samples. In total, there were 19 different assays used that fell into three categories: polymerase chain reaction (PCR), antibody reactivity and culture. The WPI has stated that culture is its most sensitive means of detecting XMRV and other gammaretroviruses; however, a laboratory problem with mycoplasma contamination prevented it from testing samples using this method. Dr. Francis Ruscetti’s lab at the National Cancer Institute (NCI) and Dr. Indira Hewlett’s lab at the Food and Drug Administration (FDA) used methods identical to WPI, as described in the supporting materials for the study.
Phase III results: red indicates positive results; orange reflects indeterminate results
The labs completed their work, submitted results and the code was broken by staff at the Blood Systems Research Institute in August. Only two of the nine laboratories, the WPI and Dr. Francis W. Ruscetti’s laboratory at the NCI, detected XMRV/MLV in any of the clinical samples contained in the coded panel. The remaining seven laboratories, including Dr. Lo’s FDA lab, only detected XMRV/MLV in the spiked positive controls, each with high accuracy. Only the WPI detected XMRV/MLVs in the CFS samples using PCR assays. The WPI assays were the least sensitive for detecting viral RNA as illustrated by the inability to detect RNA in 2 of 5 spiked plasma samples and 1 of 5 PBMC-spiked samples. The WPI and NCI/Ruscetti laboratories detected XMRV/MLVs at the same rate in CFS patient samples as in healthy blood donor samples. Further, even though each sample was represented in duplicate or triplicate, WPI and NCI/Ruscetti frequently only detected XMRV/MLVs in one of the duplicate or triplicate samples from the same subject. Sequence analysis of DNA amplified from the positive assays showed a high degree of similarity to XMRV derived from 22Rv1. Mouse DNA contamination was not found in any of the positive samples. Using the kappa coefficient as a statistical measure of agreement, it was found that even though both WPI and NCI/Ruscetti detected XMRV/MLV in some of the samples, the samples that were positive were often different samples, indicating there was no agreement on what could be called an XMRV/MLV positive sample.
The conclusion of this nearly two-year study is that XMRV/P-MLVs are not reproducibly detected in clinical samples (15 from individuals who had previously tested positive) using current, state-of-the art assays. The authors state, “our findings are reassuring with respect to blood safety and indicate that routine blood donor screening for XMRV/P-MLV is not warranted at this time.” Phase IV will not proceed, although there are results from studies of large numbers of blood donor samples pending publication.
With this closing statement, it appears that the blood safety community is satisfied with the scientific rigor of the SRWG study and that XMRV/P-MLVs are not a threat to the blood supply. It is remarkable to see this type of study done with government, commercial and private laboratories working in parallel to address a potentially serious public health issue. Even though the SRWG studied was designed as a blood safety study, it helped bring CFS into the light. Many of investigators on the SRWG previously knew little about CFS. Now they are familiar with the enormous suffering that CFS inflicts, the problems with the CFS case definition for research and the anger and passion that comes with an illness that has so long been in the dark shadows, unsolved.
bron: http://www.research1st.com/2011/09/22/study-summaries/
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verlorengezondheidman
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@Magnetronnie,
Als het besmetting zou zijn, hoe verklaren ze dan de groep reeds XMRV/MLV positief geteste ME-patienten door bijv. Prof. DML
Als het besmetting zou zijn, hoe verklaren ze dan de groep reeds XMRV/MLV positief geteste ME-patienten door bijv. Prof. DML
Een zoönose is een infectieziekte die kan worden overgedragen van dieren op mensen.
http://www.youtube.com/watch?v=wVQy9-cyL98
LyME en co's INFO-topic!
http://www.me-gids.net/index.php?name=P ... ht=#218551
http://www.youtube.com/watch?v=wVQy9-cyL98
LyME en co's INFO-topic!
http://www.me-gids.net/index.php?name=P ... ht=#218551
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magnetronnie
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)Mij ook. Het geeft echter ook aan dat de WPI nog steeds iets gevonden lijkt te hebben. Het is misschien geen XMRV, maar dan wellicht een ander (retro)virus. Vandaag spreekt Judy Mikovits als het goed is op een congres in Canada en dan horen we wellicht meer de WPI kant van dit verhaal.nijntje schreef:het feit dat een deel van de oorspronkelijke studie wordt teruggetrokken.... geeft mij toch een koude douche...