Bryan's help!!a new cause of male pattern baldness?>> the sebaceus gland

[Armando Jose]

This link could be interesting:

http://www.human.cornell.edu/units/txa/ ... s3_99.html
Hair bristles are used for cosmetic and paint brushes. Pigment extracted from the human hair is used in hair and fabric dyes while hair protein, keratin, is incorporated in animal feeds. NASA is constructing hair pillows, which absorb five times their weight in oil— an idea developed by an ingenious hairdresser.

So, hair fibre adsorb oils, I think sebum is a type of oil.

Best regards
Armando

 

[S Foote.]

Firstly Bryan, it doesn't really matter `how' the sebum coats the hair, we just know that it does! In coating the hair, the sebum `supply' is being used. In male pattern baldness there is no significant amount of hair to `use' this sebum, so effectively the `supply' vastly exceeds the `demand' in male pattern baldness, thats the point.

Not much of a point, really. I think the amount of sebum that gets transferred to hair is probably relatively small compared to the total amount that's actually produced in the scalp, unless a person spends most of his day combing his hair, scratching his head, playing with his hair, etc.!

[quote="S Foote.":be25c]The other thing that strikes me about the study you quote, is again the lack of `real' context in these `in-vitro' type studies.

In-vivo, the sebaceous gland is ideally placed to `inject' sebum into the hair shaft at a low pressure constant rate. Also absent from the experiments you quote was any reference to the temperature of the tested sebum? At the `warm' normal body temperature, the flow characteristics of sebum would be better.

I guarantee you that Eberhart and Kligman took into account the viscosity of sebum at body temperature.

I don't think sebum coats hair by mechanical transfer, i think nature's a lot smarter than that 8)

You don't even believe the findings of these serious scientists?? Somehow, I'm not terribly surprised at that! :wink:

Bryan[/quote:be25c]

Oh but i `DO' believe the results of that study Bryan! I just don't think the methodology of it in any way replicates what happens in-vivo!

Remember that any in-vitro test is only really valid if it can give a `true' insight into the in-vivo situation. Many in-vitro tests just can't do this, including this one!

But we are moving off the point here Bryan. The original question was do people think there is a cause and effect relationship between excess sebum and follicle miniaturisation?

With all due respect to Armando's theory, i don't think the evidence supports this. I think the excess sebum is an associated factor, and is not directly linked to follicle miniaturisation.

So what do you think about this question Bryan?

S Foote.

 

[S Foote.]

following on from that interesting paragraph quoted by Bryan... what is the evolutionary purpose of sebum covering all your hair shafts?

The basic evolutionary purpose is to waterproof the hair. There is also the factor of lubrication that protects the hair somewhat from entanglement, and also from being too brittle.

S Foote.

 

[Bryan]

Oh but i `DO' believe the results of that study Bryan! I just don't think the methodology of it in any way replicates what happens in-vivo!

I don't understand what you mean by that. DO YOU or DO YOU NOT agree with their conclusion that sebum only gets onto hair by direct physical contact (scratching your head, combing or touching your hair, etc.)?

But we are moving off the point here Bryan. The original question was do people think there is a cause and effect relationship between excess sebum and follicle miniaturisation?

With all due respect to Armando's theory, i don't think the evidence supports this. I think the excess sebum is an associated factor, and is not directly linked to follicle miniaturisation.

So what do you think about this question Bryan?

I agree with you completely on that, Stephen, and that scares the hell out of me!

I asked Armando some pointed questions about his theory a while back on some hairloss site (don't remember if it was this one or some other one), but he didn't really respond. That didn't sit well with me. Frankly, I'm not too sure how seriously he takes his own theory...

Bryan

 

[S Foote.]

Oh but i `DO' believe the results of that study Bryan! I just don't think the methodology of it in any way replicates what happens in-vivo!

I don't understand what you mean by that. DO YOU or DO YOU NOT agree with their conclusion that sebum only gets onto hair by direct physical contact (scratching your head, combing or touching your hair, etc.)?

I don't disagree with the `observations ' they made Bryan, but i do disagree with the conclusions they reached!

As i said, the quoted experiments could not in any way be related to the `ACTUAL' in-vivo situation!

So how `safe' are the conclusions of such experiments? Not very!!

I will give you another example that is `very' rellevant to the male pattern baldness situation!

The study of hair follicle cell growth in-vitro, is `missing' a very important in-vivo factor, that `OVERULES ANY' normal cell growth of any kind!

You've guessed it Bryan, this is the recognised control of `normal' cell growth by contact inhibition!

So, if for example it is found that substance `X' increases the multiplication of male pattern baldness follicle cells in-vitro, does this mean it will work the same way in vivo? Have we found a cure????

No, not if there isn't `room' in-vivo for any increased cell multiplication!!

Because the normal growth restricting factor of contact inhibition `IN-VIVO', will `overule' ANY increased cellular growth, under such circumstances!!

This is why any in-vitro study has to be considered in terms of what we already know about `in-vivo' principles 8)

But we are moving off the point here Bryan. The original question was do people think there is a cause and effect relationship between excess sebum and follicle miniaturisation?

With all due respect to Armando's theory, i don't think the evidence supports this. I think the excess sebum is an associated factor, and is not directly linked to follicle miniaturisation.

So what do you think about this question Bryan?

I agree with you completely on that, Stephen, and that scares the hell out of me!

Don't be scared Bryan, walk towards the light, `all are welcome' :lol:

S Foote.

 

[Bryan]

I don't disagree with the `observations ' they made Bryan, but i do disagree with the conclusions they reached!

As i said, the quoted experiments could not in any way be related to the `ACTUAL' in-vivo situation!

So how `safe' are the conclusions of such experiments? Not very!!

Please explain to me why you think that the experiments they did (dipping hairs into sebum and observing that it doesn't spread along the hair shaft, etc.) aren't "related" to the in vivo situation. It all seems pretty darned straighforward and obvious to me.

Don't be scared Bryan, walk towards the light, `all are welcome' :lol:

That IS a funny line. I laughed out loud when I read that!

Bryan

 

[S Foote.]

I don't disagree with the `observations ' they made Bryan, but i do disagree with the conclusions they reached!

As i said, the quoted experiments could not in any way be related to the `ACTUAL' in-vivo situation!

So how `safe' are the conclusions of such experiments? Not very!!

Please explain to me why you think that the experiments they did (dipping hairs into sebum and observing that it doesn't spread along the hair shaft, etc.) aren't "related" to the in vivo situation. It all seems pretty darned straighforward and obvious to me.

Well as i suggested earlier Bryan, in-vivo the sebaceous glands are an integral part of the follicle structure. They are ideally placed to `inject' sebum into the hair shaft. The experiments quoted didn't, and couldn't replicate this, instead they relied upon experiments relating to capillary action.


The `big' question for me here, is if sebum is only transfered to hair by mechanical means, rubbing etc, why do hair follicles have `inbuilt' sebaceous glands? Why has this evolved?

The `integral design' of sebaceous glands and hair follicles (the philosebaceous unit), just makes a complicated structure if there is no purpose to it? Hairy mammals don't have seperate `preening' oil glands like our feathered friends! http://www.netpets.com/birds/reference/ ... ening.html

If a purely mechanical transfer of sebum to hair happened in-vivo, integral sebaceous glands in hair follicles wouldn't be necessary! Seperate more `simple' arrangements would have been made by evolution in my opinion.

S Foote.