VOA标准英语2011--Spray Detects Hard-to-Find Tumors

（单词翻译）

Spray Detects Hard-to-Find Tumors

Surgeons may soon have a new tool to help locate early-stage cancerous growths; a spray that turns fluorescent¹ green when it comes into contact with tumors.

The spray is clear, but contains a non-toxic dye that almost immediately glows bright green when it reacts with enzymes² produced by cancerous tumors.

The fluorescent spray was developed by Hisataka Kobayashi, a researcher at the U.S. National Cancer Institute near Washington D.C.

The problem with many cancers, according to Kobayashi, is that their early-stage tumors are too small to be seen with the naked eye.

“The tiny, tiny cancer is very hard to see and then very hard to handle," says Kobayashi, "and very hard to see whether it’s removed from the body or not.”

Current attempts to image tumors - if they are even detectable³ - can take hours to days.

A fluorescent spray, now in development, detects early-stage cancer in mice.

Kobayashi and colleagues conducted experiments with mice in which human ovarian tumors had been induced. Within a minute of spraying the cancerous tissue inside the animals’ open abdominal⁴ cavities, researchers easily spotted⁵ the small tumors, which glowed bright green.

Kobayashi says the spray can help surgeons detect even the tiniest tumors which normally would be missed, increasing the chances for successful cancer surgery and making a recurrence⁶ of the cancer less likely.

Kobayashi says he expects the spray to be approved for human use by U.S. regulators within two to three years. His study describing the fluorescent cancer spray is published in the journal Science Translational Medicine.