雅思閱讀模擬題:New weapon to fight cancer

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為大家準備了雅思閱讀模擬題:New weapon to fight cancer。雅思模擬試題在雅思備考過程中所起的作用不可小覷,通過模擬練習題,我們可以很直接地了解到自己的備考狀況,從而可以更有針對性地進行之后的復習。希望以下內容能夠對大家的雅思備考有所幫助!更多雅思報名的最新消息,最專業(yè)的雅思備考資料,將為大家發(fā)布。
    Alok Jha, science correspondent
    Thursday January 11, 2007
    The Guardian1. British scientists are preparing to launch trials of a
    radical new way to fight cancer, which kills tumours by infecting them with
    viruses like the common cold.
    2. If successful, virus therapy could eventually form a third pillar
    alongside radiotherapy and chemotherapy in the standard arsenal against cancer,
    while avoiding some of the debilitating side-effects.
    3. Leonard Seymour, a professor of gene therapy at Oxford University, who
    has been working on the virus therapy with colleagues in London and the US, will
    lead the trials later this year. Cancer Research UK said yesterday that it was
    excited by the potential of Prof Seymour's pioneering techniques.
    4. One of the country's leading geneticists, Prof Seymour has been working
    with viruses that kill cancer cells directly, while avoiding harm to healthy
    tissue. "In principle, you've got something which could be many times more
    effective than regular chemotherapy," he said.
    5. Cancer-killing viruses exploit the fact that cancer cells suppress the
    body's local immune system. "If a cancer doesn't do that, the immune system
    wipes it out. If you can get a virus into a tumour, viruses find them a very
    good place to be because there's no immune system to stop them replicating. You
    can regard it as the cancer's Achilles' heel."
    6. Only a small amount of the virus needs to get to the cancer. "They
    replicate, you get a million copies in each cell and the cell bursts and they
    infect the tumour cells adjacent and repeat the process," said Prof Seymour.
    7. Preliminary research on mice shows that the viruses work well on tumours
    resistant to standard cancer drugs. "It's an interesting possibility that they
    may have an advantage in killing drug-resistant tumours, which could be quite
    different to anything we've 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 Seymour's innovative solution is to mask the virus from the body's
    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 body's immune system destroying them on the way.
    10. "What we've done is make chemical modifications to the virus to put a
    polymer coat around it - it's 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 body's 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. "There's an awful statistic of patients in the west ... with malignant
    cancers; 75% of them go on to die from metastases," said Prof Seymour.
    13. Two viruses are likely to be examined in the first clinical trials:
    adenovirus, which normally causes a cold-like illness, and vaccinia, which
    causes cowpox and is also used in the vaccine against smallpox. For safety
    reasons, both will be disabled to make them less pathogenic in the trial, but
    Prof Seymour said he eventually hopes to use natural viruses.
    14. The first trials will use uncoated adenovirus and vaccinia and will be
    delivered locally to liver tumours, in order to establish whether the treatment
    is safe in humans and what dose of virus will be needed. Several more years of
    trials will be needed, eventually also on the polymer-coated viruses, before the
    therapy can be considered for use in the NHS. Though the approach will be
    examined at first for cancers that do not respond to conventional treatments,
    Prof Seymour hopes that one day it might be applied to all cancers.