New Drug Shows Promise Against Worm Disease

New Drug Shows Promise Against Worm Disease
Experts worry that the parasite that causes schistosomiasis could become resistant to an existing treatment. Transcript of radio broadcast:
25 March 2008

This is the VOA Special English Health Report.

Scientists think they are a step closer to a new drug to treat schistosomiasis. More than two hundred million people suffer from this parasitic worm disease. Most live in developing nations in tropical climates. About ten percent of victims become seriously disabled from internal bleeding, iron loss, organ damage or other effects.

A team in the United States found that chemical compounds known as oxadiazoles can target an enzyme needed for the survival of Schistosoma. This is the group of flatworms that cause schistosomiasis.

The scientists tested oxadiazoles on laboratory mice. They found that one compound killed the parasite at every level of development – from larva to adult. The study also showed that the compound was active against all three major species of Schistosoma worms that infect humans.

The National Institutes of Health supported the research. Scientists from Illinois State University and the Chemical Genomics Center at N.I.H. reported their findings in the journal Nature Medicine.

Biology professor David Williams led the research. He says the Schistosoma parasite needs oxygen to survive. Oxygen use produces oxygen-free radicals that can destroy an organism. The worm has a protective enzyme. But Professor Williams says the experimental drug disables this enzyme, causing the worm to self-destruct.

Since the nineteen eighties, doctors in more than seventy tropical nations have used one main drug to treat schistosomiasis. Public health experts worry that the worms will become resistant to this drug, praziquantel.

Each year, two hundred eighty thousand people die of schistosomiasis, also known as bilharzia or snail fever. The microscopic worms infect snails, which in turn lay infected eggs. Humans become infected when they enter fresh water where the snails live.

The worms dig through skin to enter the body. They move into blood vessels that supply the intestinal and urinary systems. Then, if worm eggs in human waste enter fresh water, more snails and people become infected.

More studies are needed on the experimental new drug. The scientists say the results in mice were better than all the targets set by the World Health Organization for new schistosomiasis compounds. They hope the drug will be ready for testing in humans in four to five years.

And that’s the VOA Special English Health Report, written by Jill Moss. Transcripts, MP3s and podcasts of our reports are at voaspecialenglish.com. I’m Steve Ember.

----------------------------Google Translate

新的药物表明承诺对地那龙线虫病
专家担心，这种寄生虫造成血吸虫病有可能成为抗现有的待遇。全文电台广播：
2008年3月25日

这是美国之音特别英语卫生报告。

科学家认为，他们是一支接近了一步一个新的药物治疗血吸虫病。超过2.0亿人患有这种寄生虫病。大部分生活在发展中国家，在热带气候。大约10 ％的受害者成为严重伤残的，从内部出血，铁损，脏器损伤或其他的影响。

一队，在美国发现的化合物称为二唑能够针对一种酶需要为生存血吸虫。这是该集团的flatworms造成血吸虫病。

科学家测试二唑对实验小鼠。他们发现，其中一个化合物杀死寄生虫，在每个层次的发展-从幼虫到成虫。这项研究还表明，该化合物是积极反对一切三大种血吸虫蠕虫感染人类。

美国国家卫生研究院的支持研究工作。科学家从伊利诺斯州立大学及化学基因组学中心，在全国卫生研究所报，他们的研究结果在Nature杂志上药。

生物学教授戴维威廉斯率领研究。他说，血吸虫寄生需要氧气生存。氧气使用产生的氧自由基，它可以摧毁一个有机体。该蠕虫具有保护酶。但威廉斯教授说，实验性药物停用这种酶，从而导致蠕虫进行自我破坏。

自19 80年代，医生在七十多热带国家都采用的一个主要药物，以治疗血吸虫病。公共卫生专家担心，该蠕虫将成为抗拒这种药物，吡喹酮。

每年有28.0万人死于血吸虫病，又称为裂体血吸虫或蜗牛热。微观蠕虫感染性钉螺，从而奠定感染的鸡蛋。人类感染的时候，他们进入淡水如蜗牛活。

该蠕虫挖通过皮肤进入人体。他们搬进血管供应肠道和泌尿系统。那么，如果蠕虫卵在人类排泄物进入淡水，更蜗牛和人受到感染。

还需进行更多实验对实验性新药。科学家说，研究结果在小鼠体内均优于所有确定的目标是由世界生组织为血吸虫病新化合物。他们希望该药将准备作测试，人体在4时56年。

这也是该美国之音特别英语卫生报告，以书面，由吉尔苔。誊本， MP3和播客我们的报告是在voaspecialenglish.com 。我史蒂夫Ember公司。