"And he did do a study and found that of 91 autistic children, 75 had bowel disease with measlesvaccine strain virus in their gut:
http://www.ncbi.nlm.nih.gov/pubmed/11950955"
OK, let’s try this again. By citing Wakefield’s PCR work you indicate that you don’t understand either PCR or the evidence that shows in excruciating detail that Wakefield was wrong.
Wakefield was able to produce positive results even when there was NO SAMPLE in the reaction mixture. The laboratory was contaminated. The contaminant was DNA. (Measles is an RNA virus.) http://www.badscience.net/wp-content/uploads/erp_mmr.pdf
Wakefield’s reactions depended on the use of specific nucleotide sequences (PCR primers) to react with the measles sequences. Those primers, however, also reacted to HUMAN DNA to produce false-positive reactions in almost all (97%) samples from children with ASD. Wakefield did not do the necessary follow-up work to determine if the results were in fact simply false positives. When other scientists performed the necessary follow-up tests (e.g., careful examination of melting curves and/or sequencing the reaction products) they determined that the reactions produced only FALSE positive results. http://pediatrics.aappublications.org/content/118/4/1664.full.pdf+html
These primers (and also primers used by Wakefield and Kawashima) reacted with human DNA in gut biopsy samples to produce false positive results. ALL of the samples produced false-positive results with Wakefield’s primers; 10 of 41 samples produced initially positive results with the Kawashima primers, but 9 of those 10 reaction products were actually homologous to HUMAN mitochondrial DNA sequences rather than to measles virus, while the remaining initially positive sample did not correspond to measles sequences. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1954854/?tool=pubmed#ref6
(BTW, Wakefield earlier claimed to find measles virus in samples from patients with Crohn’s disease, but there, too, Wakefield was wrong because his test detected a HUMAN protein rather than measles virus.)
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"And he did do a study and found that of 91 autistic children, 75 had bowel disease with measlesvaccine strain virus in their gut:
http://www.ncbi.nlm.nih.gov/pubmed/11950955"
OK, let’s try this again. By citing Wakefield’s PCR work you indicate that you don’t understand either PCR or the evidence that shows in excruciating detail that Wakefield was wrong.
Wakefield was able to produce positive results even when there was NO SAMPLE in the reaction mixture. The laboratory was contaminated. The contaminant was DNA. (Measles is an RNA virus.) http://www.badscience.net/wp-content/uploads/erp_mmr.pdf
Wakefield’s reactions depended on the use of specific nucleotide sequences (PCR primers) to react with the measles sequences. Those primers, however, also reacted to HUMAN DNA to produce false-positive reactions in almost all (97%) samples from children with ASD. Wakefield did not do the necessary follow-up work to determine if the results were in fact simply false positives. When other scientists performed the necessary follow-up tests (e.g., careful examination of melting curves and/or sequencing the reaction products) they determined that the reactions produced only FALSE positive results. http://pediatrics.aappublications.org/content/118/4/1664.full.pdf+html
These primers (and also primers used by Wakefield and Kawashima) reacted with human DNA in gut biopsy samples to produce false positive results. ALL of the samples produced false-positive results with Wakefield’s primers; 10 of 41 samples produced initially positive results with the Kawashima primers, but 9 of those 10 reaction products were actually homologous to HUMAN mitochondrial DNA sequences rather than to measles virus, while the remaining initially positive sample did not correspond to measles sequences. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1954854/?tool=pubmed#ref6
(BTW, Wakefield earlier claimed to find measles virus in samples from patients with Crohn’s disease, but there, too, Wakefield was wrong because his test detected a HUMAN protein rather than measles virus.)
September 10, 2011 - 8:24amThis Comment
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