发信人: mail@Lion (传统医学快递), 信区: TradMedicament
标  题: [转信]◆ 长生不死(帝释天?)(agency)
发信站: 狮子吼站 (Sat Jun 15 00:37:43 1996)
转信站: Lion

 作者  agency (Zoro)                                        看板  CHIME
 标题  长生不死(帝释天?)
 时间  Mon Jun 10 22:37:13 1996
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今天我去了http://www.bio.net/ 看到这篇便又把它捉回供各位参考 我想大家都听过
长生不死(帝释天?)或青春永驻(慈禧太后?) 但是人却是必老必死的 因为各式各样细胞
有其分裂之终极次数 任你神功盖世 当全体或部分细胞一齐罢工 你想不死就实在是有
负众望 以下请看外国人由细胞分裂下手......
To: ageing@net.bio.net
From: public@BIOMED.MED.YALE.EDU (Public Workstation)
Subject: "Reversing Human Aging" by M. Fossel<反转老化>
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<门外汉>, 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<缺乏终止分裂素?>
<注> 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<终止分裂素?> with a protein that serves a primar<引子?>
for initiating replication (see the patent(专利权) application PCT
Publication No. 93/23572).

To reverse aging, Fossel proposes three methods: (1) open delivery of
telomerase<终止分裂□?><注> or a telomerase-like compound to cells,
<提供终止分裂□?给细胞> (2) adding a sequence coding for telomerase to DNA
by a vector<利用载体vector将终止分裂□密码序列加入DNA中><仅适用於胚胎尚未分
化细胞>, and (3)unrepressing the endogeneous<生自内部的> telomerase sequence
that is not expressed in somatic(身体的) cells but is expressed in germ(幼芽
) cells<将成体内不作用的终止分裂□基因序列解压制, 使如在幼体时一样表现>.
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<似合理的解释> of the telomerase theory).

2. If cell division is used to replace worn-down cells with cells that are
capable of maintaining homeostasis<原状稳定>, 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<寿命>, even if we can sustain the
immortality of other cells by a telomarase inducer<诱因>?  (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<癌细胞为不死不分化且不断分裂
的永生细胞> 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<辅导> or advice.

Thank you.
Jurgen Kaljuvee
kaljuvee@fas.harvard.edu
注<telomere ; telomerase: telo终mere裂殖粒 -ase□ 姑且译为终止分裂素;终止分
裂□ 尚期指正>
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