VOA慢速英语20061108a

HEALTH REPORT - Study Links Brain Abnormalities to Sudden Death in BabiesBy Caty Weaver¹

Broadcast: Wednesday, November 08, 2006

This is the VOA Special English Health Report.

Scientists say they have strong evidence that a biological problem could explain why


some babies die suddenly in their sleep.

Researchers from Children's Hospital Boston and Harvard Medical School examined brain tissue from forty-one babies. Thirty-one of them had died of sudden infant death syndrome², or SIDS; ten died of other causes.

The study appeared last week in the Journal of the American Medical Association. It adds to the belief that lying face down may increase the risk of SIDS as a result of pre-existing problems.

The researchers say they found abnormalities in nerve cells in the brainstems of the SIDS babies. The brainstem is involved in controlling breathing and waking from sleep. This part of the brain also controls blood pressure and body heat.

The researchers say the brainstems of the SIDS babies had far more of one kind of nerve cell than the other babies. These cells produce and release serotonin, a brain chemical believed to play an important part in controlling sleep.

Hannah Kinney of Children's Hospital Boston was a leader of the study. Doctor Kinney says normal babies will wake up, turn their head and start to breathe faster if they are not getting enough air. But if the serotonin system is bad, then a baby's brain might not get the message to react.

The scientists say that things like alcohol use and smoking when a woman is pregnant may harm the development of the brainstem.

They also found biological differences that they say may explain why SIDS happens two times as often in boys than girls.

They say the findings of their study could lead to a test for SIDS risk and possibly treatments someday. But they also note that the small size of their study represents a possible limitation of the research.

The United States records about two thousand cases of sudden infant death syndrome each year. SIDS is the nation's leading cause of death for babies between one month and twelve months of age.

But the number of cases has fallen in the past few years. This follows the launch of a campaign to urge people to place babies under one year on their back to sleep. Still, sixty-five percent of the SIDS babies in this study were found on their stomach or side.

And that's the VOA Special English Health Report, written by Caty Weaver. For more health news, with transcripts³ and MP3 files, go to www.unsv.com. I'm Steve Ember.

1 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。

2 syndrome   

n.综合病症；并存特性

参考例句：

• The Institute says that an unidentified virus is to blame for the syndrome. 该研究所表示,引起这种综合症的是一种尚未确认的病毒。
• Results indicated that 11 fetuses had Down syndrome. 结果表明有11个胎儿患有唐氏综合征。

3 transcripts   

n.抄本（ transcript的名词复数 ）；转写本；文字本；副本

参考例句：

• Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样，都是染色体DNA的转录产物。 来自辞典例句
• You can't take the transfer students'exam without your transcripts. 没有成绩证明书，你就不能参加转学考试。 来自辞典例句