I can understand that different substances, virus fragments, etc., have
different relative physiological effect. This is a problem with some of the
SI physiological units too, notably the sievert, which measures J/kg of
radiation dose multiplied by some inscrutable "quality factor" that varies
with the substance. But at some point in the manufacturing process, the
medical industry has to measure the stuff somehow, regardless of what is in
it, and they presumably do it by mass. Surely they are not counting out the
molecules or virus fragments in every pill or dose. So couldn't we say that
the IU is indirectly a measure of mass, with various mysterious "quality
factors" multiplied in?
> -----Original Message-----
> From: Scott Clauss
> >
> Some vitamin and vaccine doses are measured by their biological activity,
> which, in turn, does not directly relate to the mass of a
> discrete compound
> per unit volume (concentration), so it is impossible to give a exact
> concentration for them in any metric units (or FFUs for that matter).
> International Units (IU) are used instead. These are based on an
> internationally agreed on biologicall effect or response. I
> don't know what
> organizations do this agreeing. Vitamins A, D and E are examples of this.
> There are various forms of these vitamins with which the body can "do its
> thing." Each has a different molecular weight so to get the same effect
> would require different concentrations of each form. The vitamins you buy
> are most likely mixtures of various forms. Vaccines are sometimes made of
> busted up bits of viruses or bacteria. Some of these bits can evoke an
> immune response, but trying to get a precise mass and therefore a precise
> concentration based on which bits cause a immune response while
> discounting
> those that do not would not be useful.
>
> In short I think that dispensing vaccine by IU/mL does not disqualify
> Australia from the fully converted side of the isle.
>
> Scott C
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
> > Behalf Of Paul Trusten
> > Sent: Friday, December 01, 2000 2:33 PM
> > To: U.S. Metric Association
> > Cc: U.S. Metric Association
> > Subject: [USMA:9489] Re: Australia not fully converted yet
> >
> >
> > I'm not sure what an international unit is vis a vis SI, but it is not
> > backward. It is a correct expression of a concentration, sayeth this
> > apothecary.
> >
> > "Carter, Baron" wrote:
> > >
> > > Australia not fully converted yet. Its Quarantine and
> > Inspection Service
> > > still quotes vaccination doses in IU/ml
> > >
> > > http://www.aqis.gov.au/docs/anpolicy/dogcatapplication.pdf
> > > <http://www.aqis.gov.au/docs/anpolicy/dogcatapplication.pdf>
> > >
> > >
> > ------------------------------------------------------------------------
> > > Name: Boomerang.gif
> > > Boomerang.gif Type: GIF Image (image/gif)
> > > Encoding: base64
> >
> > --
> > Paul Trusten, R.Ph.
> > 3609 Caldera Boulevard, Apt. 122
> > Midland TX 79707-2872 USA
> > [EMAIL PROTECTED]
> >
> >
> > "No one from the Audubon Society has yet documented the
> > finding of a modified barium swallow."
> > --Byrd Ona Wyng, Forensic Ornithologist
> >
> > "Free Billy Rubin!" ---Medical Technologists' protest cry
> >
>
>
