雅思阅读模拟题：new weapon to fight cancer_雅思英语模拟题

雅思阅读模拟题：new weapon to fight cancer

　　7. Preliminary research on mice shows that the viruses work well on tumours resistant to standard cancer drugs. Its an interesting possibility that they may have an advantage in killing drug-resistant tumours, which could be quite different to anything weve had before.

　　8. Researchers have known for some time that viruses can kill tumour cells and some aspects of the work have already been published in scientific journals. American scientists have previously injected viruses directly into tumours but this technique will not work if the cancer is inaccessible or has spread throughout the body.

　　9. Prof Seymours innovative solution is to mask the virus from the bodys immune system, effectively allowing the viruses to do what chemotherapy drugs do - spread through the blood and reach tumours wherever they are. The big hurdle has always been to find a way to deliver viruses to tumours via the bloodstream without the bodys immune system destroying them on the way.

　　10. What weve done is make chemical modifications to the virus to put a polymer coat around it - its a stealth virus when you inject it, he said.

　　11. After the stealth virus infects the tumour, it replicates, but the copies do not have the chemical modifications. If they escape from the tumour, the copies will be quickly recognised and mopped up by the bodys immune system.

　　12. The therapy would be especially useful for secondary cancers, called metastases, which sometimes spread around the body after the first tumour appears. Theres an awful statistic of patients in the west ... with malignant cancers; 75% of them go on to die from metastases, said Prof Seymour.