» What is your objection here: that I used the word “necessary” to describe
» a dependency link in the experiment, or that you don’t believe that the
» necessity of full-thickness grafts is implied in this article?
Both.
» “Necessary” is the correct way to identify this key component of the
» experiment which is a dependency link between full thickness grafts and
» growth of strong scalp hair.
I think you inferred that from Orentreich’s study, but I don’t think Orentreich implied it.
» The experiment described in the 1959 Orentreich article was conducted
» using full-thickness skin grafts. I did not quote him. When I quote text I
» use quotation marks, just as you do. I rather explained in my own language
» what Orentriech did and I have tried to evaluate the experiments and
» summarize and emphasize what I considered important in the study, as his
» scientific statement in my own words. In the section you quoted from the
» article there is a clear dependency link between growth of strong scalp
» hair and full- thickness grafts: ”growth of strong scalp hair or of
» baldness lie within the local skin tissues of a full-thickness graft”. This
» means that, for the purpose of this experiment, a full thickness graft was
» understood as a requirement for the growth of strong scalp hair; this is
» why it is mentioned repeatedly in the article (read also the Methods
» section where “full thickness circular incisions were made”). The article
» is about an experiment with full-thickness grafts and it would not have
» been done that way if the experimenters have not considered that
» significant to the success of the experiment.
No. I think Orentreich was just being careful to state carefully what it is he actually did in his experiments. I certainly don’t think he meant that a full-thickness graft was essential to successful hair transplanting. Again, you’re INFERRING things that he didn’t IMPLY.
» You would be right to say,
» whatever this article says, that full skin grafts have been shown not to be
» necessary for a successful implant; that is also what I say, and indeed
» successful individual follicle transplants prove that.
Exactly.
» However,
» Orentrieich’s opinion about the importance of full-thickness grafts was
» expressed quite explicitly in this 1959 article; indeed in time some
» statements in the article have been proven somewhat erroneous or at least
» in need of additional evaluation, but that doesn’t alter the fact of their
» inclusion in the article.
I do think you’re misinterpreting what Orentreich said in that article, but what exactly is the point of dwelling on this one issue in the first place? Isn’t it a moot point?
» This study was carried out using full skin grafts and, in any experiment,
» what is done rules. This means that how the experiment is conducted is more
» important than how it is phrased in being written up and even how readers
» interpret it. After an experiment is conducted it is no longer in the
» experimenters’ domain nor under the authority of the experimenters, and
» every one else’s understanding of the results is as legitimate as that of
» the experimenters. It is however, in respect to the experimenters that what
» they say about their own work is discussed and emphasized. In my opinion
» this experiment with its use of full size skin grafts never gave any chance
» for the “recipients’ dominance” theory to even be tested. Full-size skin
» grafts eliminated much of what the recipient skin could offer for the
» recovery process, so it was reduced to performing mainly as a blood supply
» template for an implanted skin section. They only tested donors’ dominance
» over different blood supply templates. Only the more recent 2003
» Krajcik-Orentreich work gave a chance to test recipient dominance and
» strongly confirmed that it is a valid concept.
And again I point out that even modern “follicular unit” transplants have shown the same donor dominance that Orentreich had with his large grafts (at least by transplanting androgen-resistant hair follicles to areas of balding, if not in the other direction), so while I agree that there is some validity to your objection about relying on the evidence of such large grafts alone, modern medicine has caught up with that relatively minor limitation, and now supports the principle of donor dominance more completely.
As for the Krajcik-Orentreich study, it is so wildly contrived and so completely separate from the normal human experience, it has no bearing at all on the issue of donor dominance versus recipient dominance, and no conclusion at all can be drawn from it about that, one way or the other.
» I already commented on this before but I will just add that differences in
» sensitivity to androgens (assuming that this is even the real picture)
» within different follicles are not the same as a preset clock for the
» demise of that follicle. That is also why I have difficulty with the term
» “apoptosis” because if there are anti-apoptotic avenues that it is not true
» apoptosis. The concentration of androgens and other factors can be seen as
» environmental to the follicle. The demise of the follicle is not preset by
» some genetic vulnerability alone.
I agree with you on that. I don’t like the tendency some people have to say that balding hair follicles are “pre-ordained” (or somesuch) to go bald, as if they go bald precisely by some kind of genetic clock-work. However, sometimes it’s easy and tempting to think of it in such a simple way.
However, I’m a bit surprised that you seem to express some doubt in your first sentence above that there is a difference in the sensitivity of various hair follicles to androgens. Are you serious about that? How could there be any doubt about that at all?
» » So how do you explain the success AND donor dominance of modern
» » transplanted “follicular units”?
»
» Give me a specific example with a reference so that I can better
» understand your question.
What don’t you understand about my question?? I can’t give you a specific reference, because I don’t pay that much attention to hair transplantation, and I can’t even give you the names of those specific doctors who do that “follicular unit” transplanting. But surely you know what I’m talking about, right?? It’s all the rage nowadays for the most advanced doctors to do that “micro-grafting”, where only individual hair follicles are moved around. You referred to it YOURSELF, earlier in your post!
The fact that even such “micro-grafts” (or “follicular unit transplants” ) still show donor dominance is clear and powerful PROOF that donor dominance is valid. You don’t have to waste time talking about the size of plugs, the amount of skin tissue that gets transferred, whether or not there’s something in that neighboring skin that causes balding, etc.