3 Scientists Win Nobel Prize in Medicine for Parasite-Fighting Therapies
By LAWRENCE K. ALTMAN

Three scientists who used modern laboratory techniques to discover anti-parasitic drugs long hidden in herbs and soil won the Nobel Prize in Physiology or Medicine on Monday.

Their drug therapies “have revolutionized the treatment of some of the most devastating parasitic diseases,” the Nobel Committee of the Karolinska Institute in Stockholm said in announcing the winners. They are William C. Campbell, formerly of New Jersey, and Satoshi Omura of Japan, who share one-half of the $960,000 award; and Tu Youyou of China, who won the other half.

Dr. Campbell and Dr. Omura developed Avermectin, the parent of Ivermectin, a medicine that has nearly eradicated river blindness and radically reduced the incidence of filariasis, which can cause the disfiguring swelling of the lymph system in the legs and lower body known as elephantiasis.

Dr. Tu was inspired by Chinese traditional medicine in discovering Artemisinin, a drug that is now part of standard anti-malarial regimens and that has reduced death rates from the disease.

“These two discoveries have provided humankind with powerful new means to combat these debilitating diseases that affect hundreds of millions of people annually,” the Nobel Committee said in a statement. “The consequences in terms of improved human health and reduced suffering are immeasurable” because parasitic diseases “represent a huge barrier to improving human health and well-being.”

Parasitic diseases are a threat to an estimated one-third of the world’s population, particularly among the poor in sub-Saharan Africa, South Asia and Latin America. Insects transmit both river blindness (black flies) and malaria (mosquitoes).

Ivermectin and Artemisinin are included in the World Health Organization’s list of essential medicines and are distributed free or at low cost. The Nobel Committee said it was not aware of any active patents on the drugs. In 1987 Merck, which had profited handsomely from use of Ivermectin in domestic and farm animals, began distributing the drug free to people because those who needed it the most could not afford it.

Dr. Campbell and Dr. Omura collaborated but worked independently on different aspects of the discovery of Avermectin.

Dr. Campbell was born in Ramelton, Ireland, in 1930 and earned a Ph.D. at the University of Wisconsin. He worked for decades at the Merck Institute for Therapeutic Research before moving to Drew University in Madison, N.J., as part of a program where retired industrial scientists direct research of individual undergraduates. Five years ago he moved to North Andover, Mass.

Dr. Campbell learned of his award when a reporter awakened him. “I thought he was kidding, and when I asked how I could find out, the reporter suggested the website,” Dr. Campbell said in an interview.

Dr. Omura, who was born in 1935, earned two Ph.D.s from the University of Tokyo, in pharmaceutical sciences and chemistry. He is emeritus professor at Kitasato University in Tokyo. Dr. Omura applied what the Nobel Committee said were “extraordinary skills in developing unique methods” for scientifically characterizing natural products in Streptomyces bacteria found in soil. Bacterial cousins have yielded antibiotics like streptomycin.

At a news conference on Monday in Tokyo, Dr. Omura played down his accomplishments, saying, “I merely borrowed the power of microbes.” He said he was surprised by the recognition. “I never imagined I would win,” he said. “If I had, I’d have worn a nicer necktie.”

Dr. Omura carries a plastic bag to collect soil samples. From several thousand cultures of Streptomyces he focused on the 50 he thought showed the most promise against dangerous microbes.

After obtaining cultures from Dr. Omura, Dr. Campbell documented one that yielded a substance that was remarkably effective against parasites in domestic and farm animals. The sample came from a golf course near Tokyo. He named the purified substance Avermectin. Further chemical tests produced Ivermectin that killed parasites in infected humans. Their collective work produced a new class of powerful anti-parasitic drugs.

Dr. Tu, born in 1930, is chief professor at the China Academy of Traditional Chinese Medicine and the first Chinese scientist to win a Nobel science award. The Nobel Committee emphasized that it was not giving the award to traditional Chinese medicine but to a scientist who, inspired by it, went on to use sophisticated research methods to find a new therapy for malaria. The discovery came at a time when the parasites became resistant to more traditional drugs like quinine and chloroquine and as the number of infections surged.

Dr. Tu screened many herbal remedies in malaria-infected animals and extracted a promising agent from Artemisia annua. Because of inconsistencies in test results, she turned to ancient texts and discovered clues to identify and extract the active component of the Artemisia herb. In ancient times, people soaked the herb in water and boiled it. She realized that boiling could destroy the active ingredient and used other techniques to isolate it.

“Tu was the first to show that this component, later called Artemisinin, was highly effective against the malaria parasite, both in infected animals and humans,” the Nobel Committee said. Artemisinin combined with other anti-malarial drugs is part of standard regimens used in malaria-infected areas.

The committee said it had not been able to reach Dr. Tu and so did not know her reaction. Dr. Tu’s son-in-law, Lei Mao, who works at a pharmaceutical company in North Carolina, said she learned she won the award on television and was “very excited.”

對抗寄生蟲 中.日.愛爾蘭學者獲諾貝爾醫學獎

今年諾貝爾醫學獎五日揭曉，三位獲獎者分別來自愛爾蘭、日本和中國大陸，因發明對抗蛔蟲引起的寄生蟲疾病和瘧疾的革命性新療法，造福全球數億人而獲獎。

減少全球最貧窮人口痛苦

諾貝爾大會的頌辭指出，寄生蟲疾病影響全球最貧窮人口，成為改善他們健康和福祉的巨大障礙，獲獎者的發明「在增進人類健康與減少痛苦方面，重要性難以估計」。

八十五歲的愛爾蘭生化學家康貝爾（William Campbell）和八十歲的日本微生物學家大村智發現新藥阿維菌素（Avermectin)，大幅降低盤尾絲蟲病（又名河盲症）與淋巴絲蟲病（又名象皮病）發生率，使這兩種疾病幾乎絕跡，並有效治療其他一些寄生蟲疾病，兩人共獲八百萬瑞典克朗（約台幣三千一百萬元）獎金的一半。

大陸屠呦呦獲得一半獎金

八十四歲的大陸中醫學家屠呦呦獲得另一半獎金，她發明的青蒿素（Artemisinin）大幅降低瘧疾患者的死亡率。屠呦呦是中國大陸第一位諾貝爾醫學獎得主。

每年有近兩億人感染瘧疾，奪走逾四十五萬人性命，絕大多數為兒童。屠呦呦從中國草藥中尋找瘧疾新療法，黃花蒿是首選，但療效不一致，屠呦呦再從中國古文獻中找到從黃花蒿中提取活化物的方法，她提取的青蒿素對抗瘧疾非常有效，在感染初期就能殺死瘧原蟲，對於治療惡性瘧疾效果空前，降低逾兩成的死亡率，兒童死亡率更下降逾三成，意謂每年救了十萬多人性命。

大村智「獎獻給微生物學」

大村智研發出大規模培養細菌的獨特方法，他從土壤中培養鏈黴菌新菌株，並選出最有潛力的五十種。康貝爾發現大村智培養菌中的一種對抗寄生蟲特別有效，這種生物活化劑稱為阿維菌素，製成驅蟲藥「愛獲滅」（Ivermectin），被廣泛使用。

大村智接受日本NHK訪問表示，他懷疑自己是否值得獲獎，「我從微生物學中學到很多，我依賴微生物學，我要把獎獻給微生物學。」

康貝爾「藥廠團隊的努力」

曾在美國默克藥廠工作卅多年的康貝爾受訪表示得獎很意外，「這是默克藥廠的團隊努力」。

原文參照：
http://www.nytimes.com/2015/10/06/science/william-c-campbell-satoshi-omura-youyou-tu-nobel-prize-physiology-medicine.html

Video：William C. Campbell, Satoshi Omura and Youyou Tu received the 2015 prize for “therapies that have revolutionized the treatment of some of the most devastating parasitic diseases,” the committee said.
http://www.nytimes.com/video/science/100000003957798/nobel-prize-in-medicine-is-awarded.html

2015-10-06．聯合報．A13．聯合報．A1．要聞．編譯田思怡