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Biological treatment-MPD
Date: Sun, 26 Jan 1997 16:11:45 -0500
From: Norm Freeburg <nfreeburg@CYBERUS.CA>
Subject: Re: Anegrelide
Hello, Amy!!!
I'm not a chemist or pharmacist (!!!!), but I think a fair
definition of chemotherapy is "treatment of disease by chemicals." Not all
medicine or drugs are considered chemicals. Drugs may be chemical, but also
may be biological (or hormonal), even radiation therapy can be administered
in the form of a drug (radioactive phosphorus- P32). Usually when the
treatment of cancer is considered - the possibilities are chemical
(chemotherapy), biological,and hormonal (plus surgery, radiation).
Anagrelide, hydroxyurea (Hydrea), alkylating agents, all fit into the
chemical category. (HU acts by blocking DNA synthesis in formation of cells
- I think - while anagrelide disrupts or prevents the maturation of the
megakaryocytes - sort of further down the line.)
The big breakthru in biological/hormonal treatment came in 1973
(actually it wasn't quite that sudden) with recombinant gene technology
(genetic engineering). Bacteria cells were "programmed" with alternate
genes to reproduce certain proteins that they normally wouldn't make. For
the first time, substances (hormones, proteins) that previously were only
made in our bodies could now be produced in the laboratory. This meant, for
example, that kids deficient in human growth hormone could now have the
hormone readily available. Interferon was one of the first proteins to be
reproduced in the lab this way. Since then - many more are available -
erythropoietin, interleukins, growth factors, etc.
So biological treatment includes the cytokines (proteins normally
produced in our bodies - not considered chemicals). Interferon,
interleukins, some growth factors, are all cytokines. The idea is that your
own body, using material normally made in your body, is going to fight your
disease.
Hormones are also normally produced in our bodies (in endocrine
glands - kidney, thyroid, reproductive, etc.,) and they act as messengers
moving through our bodies via the bloodstream to regulate another area of
our body.
Erythropoietin (hormone that stimulates blood production) can now be made in
the lab. Various steroids also fit into hormonal therapy. There is a little
overlap here as cytokines are also considered protein hormones, but for
therapy purposes - the cytokines are usually considered biological treatment.
The University of Texas M.D. Anderson Cancer Centre has a Dept.
of Clinical Immunology and Biologoical Therapy. They have published some
interesting stuff on biological response modifiers (another way of saying
biological therapy).
Forgive me, Amy, for getting carried away! I have always found
this stuff fascinating - even before Norm got PV.
Very best to you,
Ruth