科學家探索用“冷凍法”挽救生命或開啟人類冬眠生存模式

1、科學家探索用“冷凍法”挽救生命 或開啟人類冬眠生存模式張鐵城 2016、2、22發(fā)送這篇的內(nèi)容并不十分新穎，但是還是一個科研的大進展。請多關心。張鐵城下載110 No.24參考消息2016/2/22科學家探索用“冷凍法”挽救生命 或開啟人類冬眠生存模式美國石英財經(jīng)網(wǎng)站：Researchers are “freezing” patients to avoid death COLD CASES Olivia Goldhill Quartz February 16, 2016參考消息譯文：【美國石英財經(jīng)網(wǎng)站2月16日報道】去年2月，賈斯廷·史密斯被發(fā)現(xiàn)臉沖下躺在1英尺（約合0.3

2、米）深的雪里。被發(fā)現(xiàn)時，他已經(jīng)沒了呼吸，脈搏和血壓也都消失了。他的體溫低于20攝氏度。如果從關鍵體征來看，史密斯已經(jīng)算是臨床死亡，且死亡時間已有12個小時之久。Extreme cold brings both risks and medical benefits. (Reuters/ Danish Ishmail)Last February, Justin Smith was found lying face down in a foot of snow. He wasnt breathing, had no pulse or blood pressure, and his body temp

3、erature was below 20 degrees Celsius. According to the vital signs, Smith was clinically deadand had been for 12 hours.But when paramedics at the scene called to Dr. Gerald Coleman, from Lehigh Valley Hospital-Hazleton, they was told to start CPR. Colemantold Standard Speaker, “My clinical thought i

4、s very simple: You have to be warm to be dead.”Smith was given CPR for 15 hours, pumped with warm oxygenated blood, and woke from his coma two weeks later. Less than six weeks after Smith was found “dead,” he was released from hospital. He lost his toes and pinkie fingers to frostbite, but was other

5、wise unharmed.This is not the first time someone has gone into hypothermia, lost all signs of life, and survived. Reduced body temperature means that the bodys cells have a slower metabolic rate, and so they need less energy and can survive without the breathing and blood flow usually

6、 needed to live.“Hypothermia suppresses metabolism. If it happens rapidly and significantly enough, the brain doesnt suffer irreversible damage,” H. Craig Heller, biology professor at Stanford University tells Quartz. “But if its not enough or happens too slowly, then the brain can get to the point

7、of no return.”Putting hypothermia to use in medicineThese cases of accidental hypothermia and miraculous-sounding survival stories have inspired doctors to embrace the potential life-saving benefits of cooling down.Currently, doctors reduce body temperature slightly (by a few degrees, nowhere near a

8、s extreme as in accidental hypothermia) to treatpremature babies and brain injury.But after animal trials, where pigs were cooled to 10 Celsius and survived, researchers are conducting experiments on therapeutic hypothermia for humans. The trial, which began in 2014 and is currently being

9、conducted in the University of Pittsburgh Medical Center, is used on patients who have suffered severe trauma such as gunshot wounds. Patients are cooled to give doctors more time to treat their wounds and suspend the dying process. And, in order to make the cooling process as quick as possible, the

10、 patients blood is pumped out and replaced with a cold saline solution.“The only reason we use cold saline is that we found its the fastest way to cool the brain and other organs,” Samuel Tisherman, the surgeon leading the trial, tells Quartz. “The patients have already lost more than half their blo

11、od volume because of trauma before we start the saline.” “When do you declare a person deadis it brain death, is it heart death?” Once the injuries are treated, the saline solution is then again replaced with blood and the patient is warmed up. The trial can only be conducted on patients w

12、ho are expected to die, which means it takes longer than usual to collect definitive results. Tisherman says the trial results are unlikely to be published for at least another two years.But such work has potential implications for how to determine whether someone is “dead.” Tisherman is unphilosoph

13、ical about this. “Patients are dead when we have run out of ways to save them and we declare them dead,” he says.But others acknowledge that its increasingly difficult to draw a stark line between life and death. “When do you declare a person deadis it brain death, is it heart death?” says Heller. “

14、In actuality were measuring cellular death. But were talking about trillions of cells in humans. What percentage has to die for someone to be dead?”Using hypothermia to induce long-term hibernationHypothermia is likely to become increasingly used in medicine over the coming years. But over the comin

15、g decades, scientists have an even more ambitious goal: To induce a long-term state of regulated hypothermia, or torpor, to allow humans to hibernate.Hibernation essentially allows mammals, many of which have similar body temperatures to humans, to massively reduce their body temperatures and surviv

16、e. And human hibernation has attracted the interest of the European Space Agency, which has long-term hopes of putting astronauts into hibernation for lengthy space travel.“We see the science has advanced enough to put some of the science fiction into the realm of science reality,” Leopold Summerer,

17、 head of advanced concepts team of the European Space Agency, told the Washington Post.ESA is currently working with scientists around the world to investigate the potential for hibernation in humans. But first scientists have to figure out the detailed mechanisms behind hibernation.“Hibernatio

18、n is a very complex, well-integrated physiological response that we would hope to be able to mimic with drugs in humans,” Kelly Drew, a biochemist at the University of Alaska at Fairbanks tells Quartz. “Were a long way off from understanding that complete suite of control.” “The more that we un

19、derstand what happens in hibernation, the better well be able to mimic some of these phases.” Drew has published research showing that adenosine receptors in the brain have to be stimulated for Arctic ground squirrels to reach the low body temperatures of hibernation. But Drew and her

20、 colleagues are uncertain about the natural molecular triggers, and how to replicate the effect using drugs. “The more that we understand what happens in hibernation, the better well be able to mimic some of these phases,” she says.Meanwhile Matteo Cerri, assistant professor of physiology at the Uni

21、versity of Bologna, who is also collaborating with ESA, is working on inducing torpor in pigs by inhabiting the area in the hypothalamus that controls energy levels. The trial is ongoing, but Cerri tells Quartz he hopes to have concrete results to discuss by summerand certainly within the year.Altho

22、ugh other scientists are doubtful that humans will ever be able to survive hypothermia and hibernate for extended period of time, Cerri is confident that month-long hibernations will be feasible. “An educated guess would be 40 or 50 years,” he says “But within 100 years I would definitely say yes.”I

23、nducing hypothermia in humans alone is a complicated task, and long-term hibernation is far more complex. But with the interest and funding behind this research, its possible that such farfetched-sounding hopes will become a reality.參考消息譯文：【美國石英財經(jīng)網(wǎng)站2月16日報道】去年2月，賈斯廷·史密斯被發(fā)現(xiàn)臉沖下躺在1英尺（約合0.3米）深的雪里。被發(fā)

24、現(xiàn)時，他已經(jīng)沒了呼吸，脈搏和血壓也都消失了。他的體溫低于20攝氏度。如果從關鍵體征來看，史密斯已經(jīng)算是臨床死亡，且死亡時間已有12個小時之久?？茖W家探索用"冷凍法" 或開啟人類冬眠生存模式2016-02-22 11:25:00 來源：參考消息網(wǎng) 責任編輯：雷璟核心提示：歐洲航天局正在與全世界的科學家們合作，研究讓人進入冬眠狀態(tài)的可能性。不過，科學家首先必須搞清楚冬眠背后的復雜機制。參考消息網(wǎng)2月22日報道 去年2月，賈斯廷·史密斯被發(fā)現(xiàn)臉沖下躺在1英尺（約合0.3米）深的雪里。被發(fā)現(xiàn)時，他已經(jīng)沒了呼吸，脈搏和血壓也都消失了。他的體溫低

25、于20攝氏度。如果從關鍵體征來看，史密斯已經(jīng)算是臨床死亡，且死亡時間已有12個小時之久。據(jù)美國石英財經(jīng)網(wǎng)站2月16日報道，當?shù)诌_現(xiàn)場的醫(yī)護人員打電話給美國利哈伊瓦利醫(yī)院黑澤爾頓分院的醫(yī)生杰拉爾德·科爾曼時，他們被告知應對病人進行心肺復蘇?？茽柭Q，當時之所以作此判斷是因為他的臨床思維十分簡單：身體須是溫熱的才會死亡。報道稱，醫(yī)護人員給史密斯做了15個小時的心肺復蘇，向其體內(nèi)注入了溫熱的氧合血。兩周后，史密斯從昏迷中蘇醒了過來。他康復出院之時距離被發(fā)現(xiàn)“死亡”僅過了不到六周時間。像這樣體溫過低、所有生命體征均消失，之后又活過來的事情并非首例。肌體溫度降低意味著身體細胞代謝率減緩，細胞需要的能量減少，并可在通常而言維系生命所必須的呼吸和血流均停止的情況下存活。美國斯坦福大