發信人: mail@Lion (傳統醫學快遞), 信區: TradMedicament
標  題: [轉信]◆ 長生不死(帝釋天?)(agency)
發信站: 獅子吼站 (Sat Jun 15 00:37:43 1996)
轉信站: Lion

 作者  agency (Zoro)                                        看板  CHIME
 標題  長生不死(帝釋天?)
 時間  Mon Jun 10 22:37:13 1996
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今天我去了http://www.bio.net/ 看到這篇便又把它捉回供各位參考 我想大家都聽過
長生不死(帝釋天?)或青春永駐(慈禧太后?) 但是人卻是必老必死的 因為各式各樣細胞
有其分裂之終極次數 任你神功蓋世 當全體或部分細胞一齊罷工 你想不死就實在是有
負眾望 以下請看外國人由細胞分裂下手......
To: ageing@net.bio.net
From: public@BIOMED.MED.YALE.EDU (Public Workstation)
Subject: "Reversing Human Aging" by M. Fossel<反轉老化>
Date: 9 Jun 1996 12:47:32 -0700

Michael Fossel, MD/PhD has authored a new book on aging "Reversing
Human Aging" (William Morrow and Co., Inc, NY 1996).  Although
his book is written for primarily for laymen<門外漢>, it may be of
interest to professionals as most of the arguments are also supported by
references to scientific articles.

Fossel believes that the evidence accumulated in past five years
suggests that aging is due to telomere shortening<缺乏終止分裂素?>
<註> occuring as a result of cell division. All other theories of aging are
explaining secondary phenomena or effects, not the causes, of aging.

According to Fossel, to prevent aging, it suffices to 'cap' the
telomere<終止分裂素?> with a protein that serves a primar<引子?>
for initiating replication (see the patent(專利權) application PCT
Publication No. 93/23572).

To reverse aging, Fossel proposes three methods: (1) open delivery of
telomerase<終止分裂脢?><註> or a telomerase-like compound to cells,
<提供終止分裂脢?給細胞> (2) adding a sequence coding for telomerase to DNA
by a vector<利用載體vector將終止分裂脢密碼序列加入DNA中><僅適用於胚胎尚未分
化細胞>, and (3)unrepressing the endogeneous<生自內部的> telomerase sequence
that is not expressed in somatic(身體的) cells but is expressed in germ(幼芽
) cells<將成體內不作用的終止分裂脢基因序列解壓制, 使如在幼體時一樣表現>.
Fossel thinks that (3) is most likely to be successful (see also the posting
G.J. Griffits in March discussing these three methods).

Finally, Fossel optimistically (?) forecasts that first trials on animals
will be conducted by the end of the decade, firs clinical trials by 2005
and, by 2015, telomarase therapy should be available to most citizens in the
wealthier part of the world (i.e., G-7 countries).

Here are a few questions that the book inspired.
1. Should we take this book seriously?  Are Fossel's predictions for
the timetable of the aging research at all realistic? I hope that more
knowledgeable readers of this newsgroup and researchers in the field,
in particular, also respond to this question (if you haven't read the book,
simply address the plausibility<似合理的解釋> of the telomerase theory).

2. If cell division is used to replace worn-down cells with cells that are
capable of maintaining homeostasis<原狀穩定>, fight free radicals<抗自由基>
etc., what about cells that don't divide, such as neurons and some muscle
cells (if I remember correctly)?  Shouldn't neurons wear down eventually and
thus impose a limit to lifespan<壽命>, even if we can sustain the
immortality of other cells by a telomarase inducer<誘因>?  (I hope this is a
sensible question, though I have a feeling that I'm missing a simple point
somewhere).

3. Is it plausible<似合理的> that we will be able to engineer a narrow
'corridor'<走廊> in which we can induce enough telomarase to stop, or even
reverse, aging, but not enough to cause cancer<癌細胞為不死不分化且不斷分裂
的永生細胞> in cell?  What is the 'limiting condition' for such a corridor?
 The discussion between Jean-Pierra Issa of Johns Hopkins and Mike West of
Geron has been very useful, but I would love to see some third opinions
and/or a reiteration<重述> of the argument.

4.  For a college student (or anybody for that matter) who hopes to go
on and make a contribution in this fascinating field with massive social
implications, what type of graduate education would you recommend and why?
 Obviously, this is related to the question which theory of aging is the
correct one, but I would appreciate any mentorship<輔導> or advice.

Thank you.
Jurgen Kaljuvee
kaljuvee@fas.harvard.edu
註<telomere ; telomerase: telo終mere裂殖粒 -ase脢 姑且譯為終止分裂素;終止分
裂脢 尚期指正>
--
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