当异常半球中的神经元在成熟之前经历过多的细胞分裂时，就会发生这种罕见的疾病，即大脑一侧长得比另一侧大得多。
The rare disorder, in which one side of the brain grows substantially larger than the other, occurs when neurons in the abnormal hemisphere undergo too many cell divisions before they mature.
疾病的早期诊断能够在严重的损伤发生之前给你机会采取行动。
Early diagnosis of diseases can give you a chance to take action before severe damage is done.
甚至在此之前，他们已经在寻找特定基因与不同的疾病的关系，发现可能导致乳腺癌和其他疾病的各种基因突变。
And even before that, they were linking particular genes to different diseases, finding all kinds of mutations that could lead to breast cancer and other ailments.
事实上，他在屈服于一种不相关的疾病之前生活了长达20年的时间。
In fact, he lived another 20 years before succumbing to an unrelated illness.
最近对老鼠的研究发现，在得流感之前只需一段时期的锻炼，就可以减少疾病的传染，当然，事先就有的规律性锻炼效果更好。
A recent study in mice found just a single session of exercise before catching flu reduced disease severity, although regular exercise beforehand worked even better.
比起在90岁之前的人，那些人都很少有慢性疾病。
There was no less chronic illness among survivors than among those who died before 90.
后来我们得知在之前的几个星期毛患上了一系列严重的心肺疾病，行动艰难。
We learned later that he had suffered a debilitating series of heart and lung ailments in the weeks before and that he had difficulty moving.
H1N1表明容易人际间传播并且从美国的报告提出，某些病例可以很轻微并且在之前未察觉，而疾病却进一步传播。
H1N1 appears to be passed easily from person to person, and reports from the United States suggest that some cases may be mild and therefore may go undetected, allowing the disease to spread further.
这一改变源于一个目前较为流行的观点，那就是阿尔茨海莫氏病属于神经退行性疾病的范围，在症状表现出来之前的几年就有可能发生神经系统方面的损伤。
The change reflects a modern view that Alzheimer's is a spectrum of mental decline, with damage that can start many years before symptoms appear.
“我们的目标是在某人患上老年痴呆病之前，对他的脑部进行扫描，从而预先告知他们是否处于较高疾病风险或情况开始恶化，”她说。
“The goal is to do a scan on someone before they get the disease and be able to tell if they’re at higher risk or starting to deteriorate, ” she said.
这就允许在很短时间内进行诊断，那么病人将在他们离开医生办公室之前就知道他们没有眼睛疾病或者他们需要与视网膜专家做进一步治疗。
This allows diagnoses to be made in seconds so patients will know before they leave the doctor’s office if they have no eye disease or if they need to follow up with a retinal specialist.
幸运的是，我们已有时间而且还有时间为下一次全球疾病大流行做准备，因为在疾病暴发之前已可看到它所需的条件。
By good fortune we have had time — and still have time — to prepare for the next global pandemic, because the conditions for it have appeared before the outbreak itself.
我们的母性祖先在成长过程中已经习惯性地看到许多子女(或许高达一半)在还没有机会生育子女之前便死于各种疾病、饥饿、战乱以及其它灾祸。
Our female ancestors grew accustomed to watching many of their children - perhaps as many as half - die of various diseases, starvation, warfare and so on before being able to have kids of their own.
在美国约有13%的存活产婴儿是早产，这意味着在婴儿是怀孕37周之前出生的，根据美国疾病控制和预防中心的一项调查显示。
About 13 percent of all live births in the United States are preterm, meaning the baby is born before the 37th week of pregnancy, according to the Centers for Disease Control and Prevention.
在使用这些疗法之前，特别是如果你现有一种疾病，或怀孕了或在哺乳期，要征询医生的意见。
Before using any of these remedies, especially if you have an existing medical condition, or are pregnant or breast-feeding, check with your physician.
在墨西哥，半数人群没有基础疾病；在加拿大，70%的人之前都没有重病。
In Mexico, half had no underlying health problems; in Canada 70 per cent had no major illness beforehand.
在开始任何减肥食谱之前，你要和自己的医生或者健康保健提供者确认，尤其是自己患有某些健康疾病时，包括糖尿病。
Check with your doctor or health care provider before starting any weight-loss diet, especially if you have any health conditions, including diabetes.
我们明白，试图在全世界范围内将其消灭之前，我们必须首先降低人类疾病负担。
We know that we must first reduce the human disease burden before attempting worldwide eradication.
这个结果出来以后(研究人员)便认识到了他带来的益处，研究人员也试图找到一个实时的方法，可以在疾病开始传播之前，能够提供疾病爆发的警告信号。
As this result came with the benefit of hindsight, the researchers tried to come up with a real-time measure that could potentially provide an early warning sign of an outbreak as it began to spread.
千万不要等着有眼部疾病的症状出现的时候再去就医，某些致盲的眼疾在使你视力模糊之前是不会有任何症状的征兆的。
No, it's not okay to wait for symptoms to appear. Some blinding eye diseases have few warning signs before they've taken away your vision.
尽管如此，根据疾病控制和预防中心的数据，一半以上的美国婴儿在4个月之前断奶，或是根本不进行母乳。
However, in the U.S. about half of babies are breastfed for less than 4 months, or not breastfed at all, according to the Centers for Disease Control and Prevention.
首先，在刚过去这一年，世卫组织建议，在使用抗疟药物之前，先用诊断测试法对所有疑似疟疾病例进行确诊。
First, this past year, WHO recommended that all suspected cases of malaria be confirmed by a diagnostic test before antimalarial drugs are administered.
在此之前，他已在本组织工作20余年，最初是在南太平洋岛屿防治麻风病，随后处理疫苗可预防的疾病，包括脊髓灰质炎。
Before that, he had worked for more than 20 years for the Organization, first battling leprosy in the South Pacific islands, then tackling vaccine preventable diseases including polio.
在本次暴发之前，未将安哥拉考虑为属于这一罕见疾病暴发和散在病例的地理“热区”。据认为，它在中部和东部非洲。
Prior to the present outbreak, Angola was not considered to fall within the geographical “hot zone”, thought to be in central and eastern Africa, for outbreaks and sporadic cases of this rare disease.
根据这些估计情况，男性在60岁之前死于非传染性疾病的比例可能会高达67%。
According to these estimates, the proportion of men dying under the age of 60 from NCDs can be as high as 67%.
世卫组织建议在治疗之前对所有疑似疟疾病例进行寄生虫学诊断测试(使用显微镜或快速诊断测试)予以确诊。
WHO recommends that all cases of suspected malaria be confirmed using parasite-based diagnostic testing (either microscopy or rapid diagnostic test) before giving treatment.
世卫组织建议在治疗之前对所有疑似疟疾病例进行寄生虫学诊断测试(使用显微镜或快速诊断测试)予以确诊。
WHO recommends that all cases of suspected malaria be confirmed using parasite-based diagnostic testing (either microscopy or rapid diagnostic test) before giving treatment.
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