免费日韩片_欧美成人精品一区二区男人小说_国产乱码一区二区三区四区_国产精品国产三级国产aⅴ入口_成人看的污污超级黄网站免费_欧美一级在线免费观看_成人午夜免费无码福利片_国产乱人伦偷精品视频色欲_aaa少妇高潮大片免费看_国产精品1234_亚洲精品国产suv一区88_中文字字幕在线中文无码_精品亚洲区_午夜九九九_国产av国片精品jk制服丝袜_色综合亚洲_亚洲成av人片无码bt种子下载_欧美色就色_精品少妇的一区二区三区四区_男人用嘴添女人下身免费视频

Download

This is the VOA Special English Health Report.

Last week doctors in Massachusetts announced that Senator Ted Kennedy has brain cancer.

The news came after he suffered a seizure. Doctors found a glioma, a growth in the supportive tissue of the brain. The glial tissue is where the largest percentage of brain tumors begin.

More than forty percent of growths in the brain are gliomas. But they make up almost eighty percent of cancerous growths, like the malignant glioma that Senator Kennedy has. Seizures and headaches are common first signs of a glioma.

Cancerous glial tumors generally spread in the brain the way roots spread from a plant. That makes removing the tumor more difficult. A clear border between the cancer and healthy tissue can be difficult to find.

The location of the glioma must also be considered when deciding treatment. Senator Kennedy’s tumor is in the left parietal lobe of the brain. This area is involved in some sensory understanding and spatial recognition, as well as language, reading and vision.

Removal of a glioma from this area can result in speech problems and other disabilities.

Some cancer experts believe that doctors are unlikely to operate on Senator Kennedy. They say the likely treatment is radiation and chemotherapy.

But chemical treatment for brain cancer is complex because of the protective blood-brain barrier. It stops some chemicals from entering the brain, including many chemo drugs.

Radiation treatments for brain cancer have improved a lot in recent years. New methods and equipment can permit extremely localized treatments that are less likely to damage healthy tissue.

Research into brain cancer treatment also includes drug therapy. In two thousand five, a drug called temozolomide was shown to add a few months to the lives of brain cancer patients.

And researchers are studying uses for the cancer drug Avastin. It is already used to treat breast, colon and lung cancer. It starves tumors by blocking blood flow to the growths.

The United States has about ten thousand new cancerous gliomas a year. Half of the people die within fifteen months. Malignant gliomas are more aggressive in older people.

Ted Kennedy is seventy-six years old. The senator competed Monday in the second half of a boat race in Massachusetts, finishing second in his five-boat division.

And that’s the VOA Special English Health report, written by Caty Weaver. Transcripts and MP3s of our reports are at voaspecialenglish.com. I’m Bob Doughty.

glioma:神經(jīng)膠質(zhì)瘤（腦神經(jīng)或脊神經(jīng)束上產(chǎn)生的腫瘤）

(Source: VOA 英語(yǔ)點(diǎn)津姍姍編輯)