>[Coordinator's note: Ordinarily, we don't accept messages from >non-subscribers, but this ] >[seems to me to be of compelling interest, and I am using my discretion to >pass it on. ] >[If anyone is upset by this, please blame me, and not the >Beeb. ] >[ >] >[If you can help them, you might want to contact them directly, and >possibly CC: the list ] >[ Steve > ] > > >Douglas Kell from Aberystwyth recommended writing to you as we are seeking >advice about an experiment we would like to conduct as part of a BBC >documentary. > >We're investigating recent claims which have been made that extremely high >(sub-molecular) dilutions of histamine can inhibit basophil activation in >the presence of anti-IgE. This effect has been claimed both through counting >stained cells and measuring CD63 using flow cytometry. > >(See for instance: > Belon P, Cumps J, Ennis M et al, Inflammation Research 1999; Res 48, Sup >1: 17-18 > Sainte-Laudy J, Belon P, Ultra Low Doses 1991; Taylor and Francis: 127-138 >) > >Clearly these results are very surprising and we would like to independently >test these claims by carrying out an experiment. > >The experiment would involve preparing the histamine dilutions and controls >(which we could do at a lab here in London). These would then be tested by >adding them to samples of human basophils, incubating with anti-IgE and >measuring their activation. The experiment would obviously need to be >performed a number of times. > >We are looking for a lab which might be able to help us perform this >analysis. Do you know of any laboratories world wide who would be able to >carry out this experiment? As at least a few readers of the Cytometry Mailing List may remember, the original work in this area (Davenas, E., F. Beauvais, J. Amara, M. Oberbaum, B. Robinzon, A. Miadonna, A. Tedeschi, B. Pomeranz, P. Fortner, P. Belon, J. Sainte-Laudy, B. Poitevin, and J. Benveniste. 1988. Human basophil degranulation triggered by very dilute antiserum against IgE. Nature 333:816) was debunked in Nature with great fanfare (Maddox, J., J. Randi, and W. W. Stewart. 1988. "High-dilution" experiments a delusion. Nature 334:287) some years ago. I am not familiar with either of the references cited in the e-mail, although I have followed Dr. Sainte-Laudy's later work on flow cytometric detection of basophil activation and degranulation based on antigen expression (e.g., Sainte-Laudy, J., C. Vallon, and J. C. Guérin. 1994. [Analysis of membrane expression of the CD63 human basophil activation marker. Applications to allergologic diagnosis]. Allerg Immunol (Paris) 26:211). The methodology of Davenas et al was fatally flawed for several reasons; one was that they counted too few basophils for there to be any statistical significance to their results. Although I remain skeptical that extremely high dilutions of anti-IgE, histamine, etc. affect basophil activation, I do believe that a properly designed experiment using flow cytometry, which can measure activation objectively and which allows sufficiently large numbers of cells to be counted, could provide the best test of the hypothesis. However, if you do manage to find a lab to do the experiment, you may run into a problem that occurs in studies of many types of cell activation, which is that cells don't always behave the same way when confronted with the same stimulus. We understand some, but not all, of the bases for variations in response. According to Maddox et al, Davenas et al lacked objective criteria for determining whether a particular experimental run was "valid", and the subjective choice of data to be included and excluded influenced the reported results. I'm not sure that anybody knows enough to design a conclusive experiment, but I'd be happy to continue the discussion. I'll be away from my lab (and my usual phones) from May 31 until June 6, and may or may not be picking up e-mail during that period; thereafter, I can be reached at 617-965-6044 (home/office) or 617-783-8392 (lab). -Howard Shapiro
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