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Unwanted cells and how to get rid of them
无用的细胞及其清除
There are three main classes of cells that
accumulate in the body during aging to a supernumerary degree: fat cells,
senescent cells and certain types of immune cells. 在老化期间有三个主要类型的细胞过分积累于身体中：脂肪细胞、衰老细胞和某些类型的免疫细胞。 Fat cells tend to grow and/or proliferate to
replace the muscle mass that we tend to lose with age. Interestingly, the
most conspicuous fat -- under the skin, or subcutaneous -- seems to be
relatively harmless in terms of increasingly our susceptibility to life-threatening
diseases, unless of course it gets to the stage known as "morbidly
obese" in which its sheer weight and the strain it puts on the heart are
decidedly life-threatening. 脂肪细胞倾向于生长和／或增生来置换肌群，我们倾向于随龄失去肌群。有趣的是，最显著的脂肪Ñ在皮肤之下，或称为皮下脂肪Ñ根据我们对威胁生命的疾病日益敏感，它似乎相对无害，当然，除非它搞到称为"病态肥胖"的阶段，在这个阶段脂肪所加于心脏的纯重和压力绝对威胁生命。 There is also a tendency, however, to accumulate
"visceral" fat -- fat within the abdominal cavity -- and this fat
seems to be really bad for us, because it promotes the progressive loss of
our ability to respond to nutrients coming in from the stomach. In
particular, it causes us to develop insulin resistance -- a diminished
ability of insulin to signal our muscle and other cells to absorb and store
sugar from the circulation -- and this eventually leads to Type II diabetes.
So, we really should try to get rid of the excess visceral fat cells. 然而，也有一种倾向性：积累"内脏的"脂肪Ñ腹腔内的脂肪Ñ这种脂肪似乎对我们坏到了家，因为它促进我们累进性丧失对来自胃肠营养的反应能力。特别是它引起我们发生了胰岛素抗性Ñ减低了胰岛素发信号给我们的肌肉和其他细胞从循环系统吸收和储存糖的能力Ñ最终导致II型糖尿病。因此，我们确实应该清除过剩的内脏脂肪细胞。 The second type of supernumerary cells, senescent
cells, accumulate in quite large numbers in one tissue,
the cartilage in our joints. They also accumulate elsewhere, but in much
smaller numbers; however, these may still be important by being actively
toxic. They aren't able to divide when they should, and they also secrete
abnormally large amounts of some proteins. 第二类的过多细胞是衰老细胞，大量积累于一个组织Ñ我们关节的软骨。它们也积累于其他地方，但数量少得多；然而，这些细胞可能仍然很重要，因为很有毒性。它们应当分裂时无力分裂，它们也异常地大量分泌某些蛋白质。 The third type, immune cells, is much more
complicated. In brief, the total number of white blood cells in our bodies
seems not to change very much with age, but some subsets of them become more
numerous and others less. 第三类（免疫细胞）要复杂得多。简单地说，我们身体中白血细胞的总数似乎没有太大随龄变化，但它们的某些亚群变多，而其他亚群变少。 Of particular interest are "memory cytotoxic T
cells", because people infected with certain viruses, especially
cytomegalovirus (which most of us have, in fact), accumulate a huge number of
this type of immune cell that is specifically reactive against proteins
encoded by that virus. 特别有趣的是"记忆细胞毒T细胞"，因为被某些病毒感染的人，特别是被细胞巨化病毒感染的人（实际上我们大部分人都被它感染），大量积累特异地起反应来抗击该病毒编码的蛋白质的此类免疫细胞。 Interestingly, it
seems that most of these cells aren't actually working very well anyway --
they have become dysfunctional, a bit like senescent cells mentioned above
(and possibly for the same reason, stopping themselves from dividing
uncontrollably as cancers). 有趣的是，似乎这些细胞大部分实际上都不干活了--变得功能障碍，有点像上述的衰老细胞（并可能因同样原因而阻止它们自己像癌症那样不受控制地分裂）。 Hence, it is
important to bring these cells down in number in order to leave room in the
"immunological space" for others to expand as needed; we probably
don't need to worry that this would allow the virus to harm us (though it
would certainly be good to get rid of the virus too if we can, and work is
intensive on this, because people with a compromised immune system, such as
AIDS sufferers, often experience serious symptoms from these viruses). 因此，重要的是把这些细胞的数目降下来，把"免疫学空间"留给需要的免疫细胞类型去扩展；我们也许不必担心这会让病毒伤害我们（虽然，如果我们能够，也把病毒清除掉，那敢情好，在这方面研究工作正在紧张进行，因为有危及安全的免疫系统的人，如艾滋病患者，常常因这些病毒而经受严重的症状）。 Certain other
types of immune cell seem also to become dysfunctional during aging, and
again this may be because they've divided often enough that DNA damage
responses are kicking in to stop them dividing much more. You might think
that the sensible thing for a cell to do in such circumstances is just to
die, but that might cause other, similar cells to divide more and incur more
DNA damage, so there may be an advantage to the organism to have the cell
hang around taking up space even if it can't do its proper job. 在老化期间，免疫细胞的某些其他类型似乎也变得功能障碍，这可能又是因为它们分裂太频繁，以致DNA损伤反应正在起作用来停止它们分裂更多。您可能会认为，在这种情况下，一个细胞所做的明智事情就是死亡，但这可能引起其他类似细胞分裂更多，招致更多的DNA损伤，因此，把该细胞留在附近以占据空间，即使它不能合适地工作，可能对该有机体也有好处。 Getting rid of cells is a much simpler job than
most of the other things we have to do as part of SENS. In the case of fat,
it's possible to use simple surgery, but that's unnecessarily invasive. There
are two main other ways: we can inject something that makes the unwanted
cells commit suicide but doesn't touch other cells, or we can stimulate the
immune system to kill the target cells. 比起作为SENS的一部分、我们必须去做的大部分其他事情，除去细胞是简单得多的工作。在脂肪的场合，可以利用简单的外科手术，但这是不必要地挨刀子的。有两个主要的其他方法：我们可以注射某些东西，使无用的细胞注定要自杀但又不触及其他细胞，也可以刺激免疫系统来杀死靶细胞。 Both approaches involve making use of distinctive
molecules on the surface of the target cells: luckily, different cell types
tend to have different things on their surface, so this shouldn't be too
hard. But it hasn't been done yet, and not enough people are working on it --
it needs much more attention. 这两种方法都涉及到利用靶细胞表面的不同分子：所幸的是，不同细胞类型倾向于在其表面有不同的东西，所以，这不会太困难。但这还不曾被做过，没有多少人进行这方面研究Ñ它需要更多的关注。 The immune case may in fact not need to be
addressed directly, because it may be done automatically as a simple
side-effect of my preferred anti-cancer therapy, WILT. WILT involves, among
many other things, the genetic manipulation of blood stem cells, the cells
that give rise to T cells. Thus, T cells can be made more controllable in
terms of their willingness to die on demand, by additional genetic
manipulations done to the stem cells. 免疫的例子实际上可能不需要直接提出，因为它可以作为我所首选抗癌疗法（WILT）的简单副作用而自动地进行。WILT在很多方面涉及产生T细胞的血液干细胞的遗传操作。这样，T细胞可以更加受控，可按要求使它们自动死亡，这需要对干细胞进行额外的遗传操作。 |
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