評論
打印
Science and Technology Stress and ageing A question of attitude
科技 壓力和老化 一個態度問題
The link between chronic stress and a marker of old age is being disentangled
科學家發現了長期壓力與一個衰老標志間的聯系
TELOMERES are to chromosomes what plastic caps are to shoelaces—they stop them fraying at the ends.
端粒（染色體終端）之于染色體，如同塑料帽之于鞋帶——它們阻止了其末端的磨損。
Unlike shoelaces, though, chromosomes replicate themselves from time to time as the cells they are in divide.
和鞋帶不同的是，隨著它們所在細胞的分裂，染色體可以不斷進行復制。
This shortens the telomere and, after 50-70 such divisions (a number known as the Hayflick limit, after its discoverer),
這種復制過程使端粒不斷縮短，并且，在經過50到70次的細胞分裂后（這個分裂數目稱之為海弗利克界限，因海弗利克的發現而得名），
a chromosome can grow no shorter and the cell it is in can divide no more.
染色體的縮短達到極限，細胞分裂活動也從此終止。
That provides a backstop against cancer. The rapidly dividing cells in a tumour soon hit the Hayflick limit and the process is brought to a screeching halt.
這一機制有助于對抗癌癥。快速分裂的細胞不久就會到達其海弗利克界限，使得該過程能夠急剎車。這是個好現象。
Which is a good thing. The bad thing is that reaching the limit is one of the markers of old age.
不利之處則是，細胞到達復制次數的極限是老化的標志之一。
You do not want it to happen too quickly, particularly in tissues that have to do a lot of dividing in order to work properly, such as those in the immune system.
人們不想讓這個過程發生的太快，尤其對于那些需要不斷分裂才能夠得以正常運作的組織而言，例如免疫系統組織。
It has been known for some time that chronic stress (caring for a child with a protracted illness, for example) causes premature shortening of the telomeres.
人們已經得知，長期的壓力（例如，照料一個疾病遷延不愈的兒童）可以使端粒的縮短提前發生。
What has not been clear is whether this is a one-way trip, with each stressful period turning the telomeric ratchet irreversibly.
然而人們對于該過程是否單向進行（即壓力時期對端粒的改變作用不可逆轉）尚不明確。
This week, though, at a meeting of the American Association for Cancer Research in Orlando, Florida, a group of researchers led by Edward Nelson of the University of California, Irvine, showed that it isn't.
然而，本周在美國癌癥研究學會于佛羅里達州奧蘭多召開的會議上，加州大學爾文分校由愛德華?尼爾森領導的研究團隊發現，這一過程是可逆的。
Their research suggests that stress management not only stops telomeres from shortening, it actually promotes their repair.
他們指出，抗壓力訓練不僅可以組織端粒縮短，也可以促進其修復。
Dr Nelson drew this welcome conclusion from a previous study that measured the impact of telephone counselling on women who had been treated for cervical cancer.
尼爾森博士通過對接受宮頸癌治療的婦女電話咨詢影響作用的研究，得出了這一可喜的結論。
The study found that such counselling worked, both mentally and physically.
他們之前的研究發現，咨詢在心理和生理上都產生了作用。
Women who had been counselled reported that the quality of their lives had improved, compared with those of a control group who had not been counselled.
接受咨詢的婦女報告其生活質量得到提高（與未接受咨詢的對照組相比）。
They also showed improvements in the strength of their immune systems.
她們還顯示出免疫系統功能的增強。
Given those benefits, Dr Nelson wondered if he could find others, and he re-examined the participants' samples to look at the lengths of the telomeres in their white blood cells (red cells have no nuclei, and therefore no chromosomes).
由于咨詢的上述益處，尼爾森博士想知道該研究是否能有更多的發現。他重新檢查了被試的血液樣本，試圖獲得白細胞端粒長度的信息（紅細胞沒有細胞核，因此沒有染色體）。
What he found surprised him. Not only did counselling stop telomere shrinkage, it actually promoted telomere growth.
研究發現令他十分驚訝：咨詢不僅阻止了端粒的縮短，同時促進了端粒的生長。
Those women for whom counselling had worked (ie, those who reported a decrease in emotional stress) had longer telomeres at the end than they did at the beginning.
那些報告咨詢產生效果的婦女（例如，報告情緒壓力降低）其咨詢后的端粒長度大于咨詢前。
Their Hayflick countdowns were being reset.
她們的海弗利克倒計時得到了重新的設置。
A single such result must, of course, be treated with caution.
當然，我們應該謹慎看待單個研究的結論。
But another study reported at the meeting, by Elizabeth Blackburn of the University of California, San Francisco (who shared the Nobel prize for the discovery of the enzyme that repairs telomeres), gave some support.
但該會議上另一個來自加州大學舊金山分校伊麗莎白?布萊克本（她由于發現了端粒的修復酶而與其他研究者共同獲得諾貝爾獎）的報告也給出了一些支持證據。
This showed that exercise has a similar effect to counselling on the telomeres of the stressed.
她們發現鍛煉和咨詢對壓力個體的端粒有相似的作用。
If Dr Nelson's work is successfully replicated, it will shine more light on the ill-understood relationship between the health of the mind and the health of the body.
如果尼爾森博士的研究得到成功的重復，將會為理解神秘復雜的身心健康關系點燃新的希望。
For, as he points out, nothing actually changed in the lives of the women in question.
就像他所指出的那樣，這些婦女的生活沒有任何變化。
They still had cancer, albeit under treatment, and they were still under stress. Nothing, that is, except their attitude.
盡管接受治療，她們仍身患癌癥，并處于壓力之中。唯一改變的，就是她們的態度。
