Dear Dr. Karlsson,
Thanks for your quick reply.
I have come across your paper, and read it. However, this Surge function is
only able to identify one Pulse. When multiple pulses exist, it will not work
unless several surge functions added (possible?), which will over-parameterize
model. Please correct me if I am wrong. I am looking for an algorithm to be
capable to identify multiple pulses.
Thank you again, and have a nice weekend,
Jian
Mats Karlsson <[EMAIL PROTECTED]> wrote: v\:*
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st1\:*{behavior:url(#default#ieooui) } Dear Jian,
We have good experience of a surge function. Surges, characterised by the
parameters SA (surge amplitude), SW (surge width), T (clock time) and Pt (peak
time), were used to define the function g(clock time) according to Eq. 4.
g(Clock time) = SA / (((T Pt) / SW)4 + 1)
(Eq.4)
This was presented by Nelamangala et al below (applied to LH surges). We
applied it to ACTH / Cortisol. It was superior to (sum of) cosine functions for
these hormones.
Best regards,
Mats
Nelamangala N, Pechstein B, Erb K, Klipping C, Hermann R, Locher M, Derendorf
H. Pharmacokinetic/Pharmacodynamic modeling of luteinizing hormone (LH)
suppression and LH surge delay by Cetrorelix after single and multiple doses in
healthy postmenopausal women. J Clin Pharmacol 2003; 43:243-251.
Lonnebo A, Grahnen A, Karlsson MO.
An integrated model for the effect of budesonide on ACTH and cortisol in
healthy volunteers.
Br J Clin Pharmacol. 2007 Feb 28; [Epub ahead of print]
Mats Karlsson, PhD
Professor of Pharmacometrics
Div. of Pharmacokinetics and Drug Therapy
Dept. of Pharmaceutical Biosciences
Faculty of Pharmacy
Uppsala University
Box 591
SE-751 24 Uppsala
Sweden
phone +46 18 471 4105
fax +46 18 471 4003
[EMAIL PROTECTED]
---------------------------------
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jian Xu
Sent: Friday, March 30, 2007 23:07
To: [email protected]
Subject: [NMusers] Modeling Growth Hormone Pulsatility
Dear everyone,
I am looking for any reference for modeling hormone pulsatility in PK
softwares.
Would you recommend some good articles to me? Or any suggestion?
Thanks in advance.
I searched PubMed, and the Pulsatility can be modeled by some statistical
models, which is not that easily to translate and implement in PK software,
such as NONMEM, or ADAPT II.
Jian
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