Want to Know Your Disease Risk? Check Your Exposome A)When it comes to health, which is more important, nature or nurture? You m

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问题                Want to Know Your Disease Risk? Check Your Exposome
A)When it comes to health, which is more important, nature or nurture? You may well think your genes are a more important predictor of health and ill health. Not so fast. In fact, it transpires(得知)that our everyday environment outweighs our genetics, when it comes to measuring our risk of disease. The genome is out — welcome the exposome
B)"The exposome represents everything a person is exposed to in the environment, that’s not in the genes," says Stephen Rappaport, environmental health scientist at the University of California, Berkeley. That includes stress, diet, lifestyle choices, recreational and medicinal drug use and infections, to name a few. "The big difference is that the exposome changes throughout life as our bodies, diets and lifestyles change," he says. While our understanding of the human genome has been growing at an exponential(迅速发展的)rate over the last decade, it is not as helpful as we hoped in predicting diseases. "Genes only contribute 10 per cent to the overall disease burden," says Rappaport. "Knowing genetic risk factors can prove absolutely futile(无用的)," says Jeremy Nicholson at Imperial College London. He points to work by Nina Paynter at the Brigham and Women’s Hospital in Boston, who investigated the effects of 101 genetic markers implicated in heart disease. After following over 19,000 women for 12 years, she found these markers were not able to predict anything about the incidence of heart disease in this group.
C)On the other hand, the impact of environmental influences is still largely a mystery. "There’s an imbalance between our ability to investigate the genome and the environment," says Chris Wild, director of the International Agency for Research on Cancer, who came up with the idea of the exposome. In reality, most diseases are probably caused by a combination of the two, which is where the exposome comes in. "The idea is to have a comprehensive analysis of a person’s full exposure history," says Wild. He hopes a better understanding of exposures will shed a brighter light on disease risk factors.
D)There are likely to be critical periods of exposure in development. For example, the time from birth to 3 years of age is thought to be particularly important. "We know that this is the time when brain connections are made, and that if you are obese by this age, you’ll have problems as an adult," says Nicholson. In theory, a blood or urine sample taken from an individual could provide a snapshot of what that person has been exposed to. But how do you work out what fingerprints chemicals might leave in the body? The task is not as formidable(艰难的)as it sounds. For a start, researchers could make use of swathes of biobank information that has already been collected. "There has been a huge international funding effort in adult cohorts(一群)like the UK Biobank already," says Wild. "If we improved analysis, we could apply it to these groups."
E)Several teams are also working towards developing wearable devices to measure personal exposure to chemicals in the environment. "We can put chemicals in categories," says Rappaport. "We could start by prioritising toxic chemicals, and look for markers of these toxins in the blood, while hormones and metals can be measured directly." Rappaport is looking at albumin, a common protein in the blood that transports toxins to the liver where they are processed and broken down. He wants to know how it reacts with a range of chemicals, and is measuring the products. "You can get a fingerprint — a display of all the products an individual has been exposed to."
F)By combining this information with an enhanced understanding of how exposure affects health, the exposome could help better predict a person’s true disease risk. And we shouldn’t have to wait long — Rappaport reckons we can reap the benefits within a generation. To this end, the US National Institutes of Health has set up an exposure biology programme. "We’re looking for interactions between genes and exposure to work out an individual’s risk of disease," says David Balshaw, who manages the programme. "It would allow you to tailor(使合适)the therapeutic response to that person’s risk." An understanding of this interaction, reflected in a person’s metabolic(新陈代谢)profiles, might also help predict how they will respond to a drug. Nicholson has been looking for clues in metabolite profiles of urine samples.
G)Last year, his research group used these profiles to predict how individuals would metabolise paracetamol(扑热息痛). "It turned out that gut microbes were very important," says Nicholson. "We’ve shown that the pre-dose urinary metabolite profile could predict the metabolism of painkilling drugs, and therefore predict drug toxicity." The findings suggest that metabolic profiles of exposure could help doctors tailor therapies and enable them to prescribe personalized medicines. Justin Stebbing at Imperial College London has already shown that metabolic profiles of women with breast cancer can predict who will respond to certain therapies. It is early days, but the initial findings look promising. "We’re reaching the point where we’re capable of assessing the exposome," says Balshaw. With the implications for understanding disease causes and risks, and a real prospect of developing personalised medicine, the exposome is showing more promise than the genome already, he adds.
Bugging your biosphere
H)How does air pollution or stress leave a trace in the blood? The US National Institutes of Health in Bethesda, Maryland, is trying to find out. One group funded by the NIH and led by Nongjian Tao at Arizona State University’s Biodesign Institute in Tempre is developing wearable wireless sensors to monitor an individual’s exposure to environmental pollutants. Tao’s team started by creating software for Windows phones, but they are working on apps that could be used on any smart phone. In theory, anyone could pop on(戴)a sensor and download an app to receive real-time information on exposure to environmental pollutants. At the same time, smart phones monitoring your location can combine the level of pollution with an exact time and place. Tao presented his sensor at the Circuits and Systems for Medical and Environmental Applications Workshop in Yucatan Mexico last week.
I)"We’re now moving prototypes into human studies, and progressing those prototypes into products," says David Balshaw of the NIH. Earlier this year, Tao’s group tried out the sensor on individuals taking a stroll around Los Angeles, California. They were able to measure how exposure to pollutants changed as each person wandered near busy roads and petrol stations.
Nicholson says that one’s period from birth to the age of three is a period that forms his brain connection.

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答案D

解析 根据题干中的Nicholson,from birth to the age of three和brain connections将本题出处定位于D)段第2、3句。题干中的forms his brain connection是对该句中brain connections are made的同义转述。其中第3句this is the timewhen brain connections are maded?的this指的是前一句中的the time from birth to 3 years of age,其意思是从出生到三岁这一阶段是大脑结构形成的阶段。
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