999精品在线视频,手机成人午夜在线视频,久久不卡国产精品无码,中日无码在线观看,成人av手机在线观看,日韩精品亚洲一区中文字幕,亚洲av无码人妻,四虎国产在线观看 ?

THE 1,500 YEAR WAR

2017-09-21 07:44:38
漢語世界 2017年5期

THE 1,500 YEAR WAR

BY LIU JUE (劉玨)

Chinese scientists offer fresh hope in the long quest to eradicate malaria

千年抗瘧史的新篇章:青蒿素在非洲

professor Song Jianping started his research into tropical disease in 1998, and has since led several overseas antimalarial programs

A field of Artemisia annua in Guangxi helps provide the world with artemisinin, the raw ingredient for the latest antimalarial medicine

When Tu Youyou was awarded a Nobel prize in 2015 for her work on the antimalarial drug artemisinin, she credited a 1,500-year-old Daoist with her find. Ge Hong (葛洪) , a fourth-century physician, was searching for alchemy ingredients when he unwittingly found an alternative path to immortality. Traveling through Guangdong, Ge was invited to stay at Luofu Mountain by the local governor, where he started practicing and studying local medicine, eventually compiling The Handbook of Prescriptions for Emergencies (《肘后備急方》) .

Centuries later, a key passage in this ancient tome inspired the 2015 Nobel laureate Tu to study the sweet wormwood plant for the treatment of malaria. Her efforts eventually led to artemisinin, a drug that’s saved hundreds of thousands of lives.

Now Chinese scientists are hoping to use artemisinin-based drugs in coordination with new methods of tackling the disease, involving mass drug administration and source eradication, in a bid to wipe out the disease entirely. It has been a millenialong battle. A mosquito-borne tropical disease that still infects nearly 200 million people every year, malaria causes fever, anemia, chills, andheadaches, and can lead to organ failure and death if not treated properly. Artemisinin—a key ingredient of the compound drug Artequick—is a highly effective compound with a close to 100 percent response rate for treating malaria.

Ge’s original prescription involving the wormwood plant, known as qinghao (青蒿), was picked up from common folk remedies and incorporated into Traditional Chinese Medicine, before Tu began applying modern scientific methods to study its efficacy and develop a drug that could be produced in useful quantities to tackle malaria’s spread.

But this breakthrough was still a long way off when Tu and her team began studying the disease as part of a top-secret military research project assembled during the Vietnam War. Soldiers on both sides had built up resistance to existing remedies like quinine and chloroquine. While the United States was testing a new series of synthetic drugs, Vietnam turned to its Communist ally China for help.

The year 1967 was hardly the best time for clinical research in China—quite the opposite, in fact. Research institutes across China were in paralysis, and the Cultural Revolution was in full swing. But a direct order from Chairman Mao led to the assembly of a secret leading committee. Their first conference took place on May 23, 1967, in Beijing (hence the

mission’s codename, “523 Project”). During the next 13 years, over 60 scientific research institutes, up to 3,000 scientists, and countless local staff and personnel were mobilized to assist the 523 Project—a collective effort on a previously unimaginable scale. It led to some of the most distinguished breakthroughs in antimalarial research ever, while provoking controversy over the credit for decades to come.

Local volunteers in Comoros assist with the distribution of Artequick

With limited experience in scientific research and pharmaceutical development, the project was later compared to finding a needle in a haystack. The team was divided into several groups that studied chemical synthesis, clinical trials, transmission, immunity, TCM, and more. The Guangzhou University of Chinese Medicine (CUCM) was one of the first institutes to join. Led by Professor Li Guoqiao, the CUCM team was initially assigned to study acupuncture, which turned out to have little effect on treating malaria. But Li developed a deep understanding of the development of malarial parasites, and when Tu and her team later successfully extracted a pure form of artemisinin, Li was assigned to study its clinical trials. In 1974, he was able to confirm artemisinin’s rapid efficacy and minimal side effects.

Identifying the extract was just the first step. Developing an effective drug that could be produced in useful quantities was the CUCM team’s next goal—one that turned out to be far more complicated than previously imagined.

Artemisinin and its derivatives were mainly ineffective because the seven-day course of oral treatment was too long. Most malarial epidemic areas are poor, which means patients usually stop taking medication once symptoms fade, to avoid further costs. Many also share drugs with family members to save money, further undermining their usefulness in fully eradicating the disease from the body.

In the 1980s, CUCM began developing compound drugs to shorten the treatment to three days. Li’s team produced four generations of effective artemisinin compounds over the next two decades. In 2004, they partnered with Guangdong New South Group to found Artepharm, a pharmaceutical company developing and manufacturing artemisinin-based medication for the international market. Their products include Artequick, a compound of artemisinin and piperaquine able to cure malaria with a once-daily, two-day course.

But the overall goal is prevention, rather than cure. Traditional methods to control malaria—spray pesticides, repellent, window screens—heavily focus on eradicating or stymieing its vector, the mosquito. In 1955, encouraged by early results of the pesticide DDT, the World Health Organization (WHO) started the Global Malaria Eradication Program (GMEP). But GMEP was abandoned 14 years later, having achieved no major success in Sub-Saharan Africa, which accounts for 80 percent of malarial infections.

The director of Disease Control and prevention explains the antimalarial scheme to local volunteers in Comoros in 2013

For Song Jianping, a key CUCM professor who has led several overseas antimalarial programs in Southeast Asia and Africa, the efficiency of projects like GMEP are limited in many tropical areas.“Lots of the local houses are not fully enclosed from the outside,” explained Song, “so not even a screen or repellent at their entrances can protect the residents inside.” Even if they could, mosquitos in the wild would still pose a threat.

“The infection is fluid: When one person gets infected, even if they are treated during that period, they may have already passed it on to someone else, and that person would become a new origin of infection,” Song told TWOC. “In heavily infected areas, if the disease cannot be controlled quickly and effectively, people will continue to get sick and even die.”

China had gone down the same path, spending vast resources on controlling malaria using traditional methods, taking decades to produce results in areas along the Yangtze River, Hainan, and Yunnan provinces. The inefficiency spurred GUCM to switch their focus from mosquitos to human hosts, curing the disease while blocking further infection. This new scheme, named “Fast Elimination of Malaria by Source Eradication”(FEMSE), costs less than 100 RMB per patient and is considered by many to be ideal for heavily infected areas.

Between 2004 and 2006, Song worked with Cambodia’s State Ministry of Health and Center for Disease Control to promote FEMSE among 28,000 villagers in highly infected areas in Kampong Speu province and its peripheral area, curbing mortality rates by more than 90 percent in area where 95 percent of residents took Artequick once a month, for two months.

The biggest victory so far has been on the island nation of Comoros, in the Indian Ocean, where malaria was the archipelago’s biggest public health problem and cause of death by disease. With the approval of the National Ministry of Health and Ethics Committee, FEMSE was deployed between 2007 and 2013 using mass drug administration (MDA) on all three major Comoros islands, slashing mortality by 98 percent. In 2014, there was not a single death from malaria on Comoros.

Though similar in method to a vaccine, MDA treatment is not without critics. “People who ask ‘Why give drugs to people with no symptoms’have no idea how malaria works,”Professor Li told Guangzhou Daily, responding to complaints that one Japanese researcher had made to the WHO over Li’s methodology in Cambodia. He believes there are minimal side effects to drugs like Artequick. “With the transmission model of the disease, human vectors are also in a dynamic status. Today there could be 50 people infected and tomorrow, another 50…Only MDA can ensure the break of the infection cycle.”

Having been at the forefront of both the Cambodia and Comoros projects, Song emphasizes the importance of working with local groups to fight malaria, who can keep a close watch on the spread of the infection. His team trained over 4,000 volunteers on to work with the FEMSE program who were key to its success. “Building on decades of solid work, we now have this low-cost, safe, and effective scheme to eradicate malaria,” said Song. “The rest is beyond science.”

“WE NOW HAVE THIS LOW-cOST, SAFE, AND EFFEcTIVE ScHEME TO ERADIcATE MALARIA; THE REST IS BEYOND ScIENcE”

主站蜘蛛池模板: 国产成人啪视频一区二区三区| 在线观看欧美国产| 青青操国产视频| 国产区网址| 欧美一区二区啪啪| 亚洲水蜜桃久久综合网站| 日本精品影院| 色综合a怡红院怡红院首页| 色偷偷综合网| 四虎在线高清无码| 国产午夜无码专区喷水| 丁香婷婷综合激情| 婷婷亚洲天堂| 久久激情影院| 欧美一级在线| 国产精品一线天| 日韩在线第三页| 无码内射在线| 国产乱人伦AV在线A| 久久大香伊蕉在人线观看热2| 日韩无码黄色| 亚洲综合一区国产精品| 色老二精品视频在线观看| 国产福利一区视频| 国产婬乱a一级毛片多女| 日本欧美成人免费| www.亚洲色图.com| 亚洲精品男人天堂| 国产午夜无码专区喷水| 色综合久久无码网| 欧美性精品| 色婷婷成人网| 成人亚洲视频| аv天堂最新中文在线| 国产成人午夜福利免费无码r| 国产主播福利在线观看| 久久国产拍爱| 色婷婷天天综合在线| 国产精品hd在线播放| 欧美国产日韩在线观看| 免费国产高清视频| 国产91精品久久| 亚洲国产成人在线| 91黄视频在线观看| 国产十八禁在线观看免费| 蜜臀AV在线播放| 日韩A级毛片一区二区三区| 高清无码一本到东京热| 国产91熟女高潮一区二区| 亚洲欧洲自拍拍偷午夜色| 欧美成人二区| 亚洲伊人久久精品影院| 韩日免费小视频| 国产在线观看精品| 国产无码性爱一区二区三区| 精品人妻一区二区三区蜜桃AⅤ| 欧美日本在线| 噜噜噜综合亚洲| 欧美精品不卡| 精品一区二区久久久久网站| 亚洲综合九九| 中文字幕一区二区人妻电影| 欧美三级日韩三级| 国产精品无码影视久久久久久久| 国产网站在线看| 亚洲国模精品一区| 欧美一区二区三区国产精品| 91成人免费观看| 国产不卡在线看| 国产区网址| 波多野结衣一区二区三区AV| 国产aⅴ无码专区亚洲av综合网| 69视频国产| 无码'专区第一页| 亚洲精品中文字幕无乱码| 久久a级片| 久久精品一品道久久精品| 米奇精品一区二区三区| 欧美a网站| 欧美成人综合视频| 青青极品在线| 亚洲第一页在线观看|