Remember that I said that I'd try to get a hold of the adrenal study done
in the Netherlands?  Did so.  Also, figured that it pays to have those
which extremely strong backgrounds look at the numbers and the plots since
that is where many of the complaints arose.  (Hope thing like doctorates in
math and high energy physics satisfy folks for that.) Comments received
were all bad and ranged from: "The sample is too small to tell anything."
to "Someone wanted to see something so badly he convinced himself it was
there." to something I'm not repeating about redoing math classes.  So,
basically the math from that isn't illustrative as it stands.  I won't
repeat considerations discussed by people in past letters; you know of
those.
 
Thought it might be useful to clarify some things in relation to what the
study approached or said.  Here are some quotes:
 
1. "Because hyperadrenocortism is most often detected in neutered ferrets.
it has been suggested that early neutering may contribute to the high
prevalence ... in ferrets." Note that this statement is in relation to
neutered vs.  whole, not early neuters vs.  later ones.  Note the uses of
"suggested", and "may contribute".
 
2. This one is very interesting.  I have NOT seen the studies referenced,
but can see where they might be of interest in relation to rates among
neutered ferrets.  "This theory is based on results of studies in certain
strains of mice that develop nodular hyperplasia or adrenocortical tumors
in 1 or both adrenal glands after neutering at an early age." Studies are
the authors' numbers 6-8: Feke E, Woolley G, Little CC.  Histological
changes following ovariectomy in mice, J Exp Med 1941;74:1-7; Murthy ASK,
Brezak MA, Baez AG.  Postcastrational adrenal tumors in two strains of
mice: morphologic, histochemical, and chromatographic studies.  J Natl
Cancer Inst 1970;45:1211-1222; Sharawy MM, Liebelt AG, Dirksen TR, et al.
Fine structural study of postcastrational adrenocortical carcinomas in
female CE-mice.  Anat Rec 1980; 198:125-133.  These are all old studies.  I
MIGHT be able to get the Anatomical Record one through some people I used
to work for, but don't know if I even have time to try.
 
3. "The objective of the study reported here was to determine the
prevalence of hyperadrenocorticism in the Dutch ferret population, in
which neutering at an early age is not a common practise ..."
 
 
The last half of the last paragraph had an interesting breakdown of some
of the hormonal feedback mechanisms postulated to possibly be related if
neutering does actually contribute to adrenal hyperplasia.  In case anyone
wants to track these down they are resources numbers 1, 4, 10, 11, and
pers.  com a: Johnson-Delaney CA, Washington Regional Primate Center,
U of WA, Seattle: pers com 1999; Lipman NS, Marini RP, Murphy JC, et al.
Estradiol -17-B secreting adrenocortical tumor in a ferret.  J Am Vet Med
Assoc 1993; 203:1552-1555  (Note that I do not know how to do "beta"
properly -- sigh.); Rosenthal KL, Peterson ME, Quesenberry KE, et al.
Hyperadrenocorticism associated with adrenocortical tumor or nodular
hyperplasia of the adrenal gland in ferrets: 50 cases (1987-1996).  J Am
Vet Med Assoc 1993; 203:271-275; Donovan BT, Ter Haar MB.  Effects of
luteinizing hormone releasing hormone on plasma follicle-stimulating
hormone and luteinizing hormone levels in the ferret.  J Endocrinol 1977;
73:37-52; Pabon JE, Li ZM, et al.  Novel presence of luteinizing hormone
releasing hormone/chorionic gonadotropin receptors in human adrenal glands.
J Clin Endocrinol Metab 1996;81:2397-2400.
 
(If that premise hold up there might be preventative medical approaches
worth consideration in the far(?) future.  That's my own personal hope
rather than something the authors mentioned, and I do NOT have a background
in endrocrinology which goes beyond part of a senior course so adjust the
realism of my hopes for that factor.)
 
Anyway, I promised so here's what little there was to add.  It would pay
to take this in conjunction with the earlier multiple posts by multiple
individuals on the topic rather than as a stand-alone.  Take into account
that I am exhausted, old, and rusty, please.  Hope this helps.
[Posted in FML issue 2963]