Study: Breaking Blood-Brain Barrier to Treat Brain Diseases

 

From VOA Learning English, this is the Health & Lifestyle report.

Our brains are protected by our skull¹. But that is not the only protection it has.

A natural barrier around our brains prevents germs and other damaging substances in the blood from entering the brain. Doctors call this protection the "blood-brain barrier."

However, it does more than protect.

This barrier also stops medicines from entering the brain. Doctors have trouble using drugs to treat brain tumors, Alzheimer’s and other diseases affecting the brain. So researchers have been trying to find safe ways to get drugs through the barrier.

Research on mice

At Imperial College, London, researchers have been performing experiments with mice. Doctor James Choi is a leader of this research effort. He describes the blood-brain barrier as a secure entry point -- what he calls border patrol. This keeps out harmful germs or pathogens. But it also keeps out good things.

"You can think of it as a kind of gateway³, or border patrol that is saying the brain needs glucose⁴, that's allowed in. All the foreign pathogens -- you're stopped at the door. You're not allowed to come into the brain."

He and other researchers have shown that high frequency sound waves can help open parts of the blood-brain barrier. For this to work, the sound waves must pass through a thick substance or gel. The researchers say the method is much like ultrasound imaging tests used on pregnant women.

First, researchers injected very small bubbles into the bloodstream. Then they added soundwaves to make the bubbles vibrate. This caused cells in the blood vessel⁵ walls to stretch, enabling drugs to reach the brain.

Research on humans

Similar experiments are being performed at Sunnybrook Health Sciences Centre in Toronto, Canada.

Back in 2015, researchers at Sunnybrook became the first to break the blood-brain barrier to treat a brain tumor².

In late July 2018, Sunnybrook reported on the latest research. The New York Times newspaper reports that Dr. Nir Lipsman led the study. In the statement, Lipsman described the project as a "major goal of neuroscience” for years adding that it is "exciting."

Six Alzheimer's patients were part of a small test at Sunnybrook. Lipsman and his team wanted to see if targeted sound waves could break a hole in the blood-brain barrier for a brief period.

Dr. Sandra Black worked with Lipsman on this trial. She says the experiment showed that the barrier opened. It let some harmless fluid flow in, and then it closed back up.

"It just took two ultrasound treatments to show that the blood-brain barrier can be opened. It's very exciting, I feel quite emotional about it because there's a lot riding on this, and it's a whole new world of possibilities. But we have to take one step at a time, we have to make sure it's safe."

The researchers add that as the technology improves, doctors will be able to target very small areas of the brain. They hope to target only the areas that need treatment.

Dr. James Choi adds that this kind of targeting will be an important part of future treatments.

"We can make large beams, small beams. We can steer⁶ the beam to any location in the brain. So the technology's so advanced at this point where we can actually deliver the drug to any region of the brain."

It may be a long time before doctors can use this form of treatment. However, as Alzheimer's cases increase around the world, scientists are trying every way possible to help patients.

I'm Anna Matteo.

Words in This Story

skull – n. the structure of bones that form the head and face of a person or animal

glucose – n. a type of sugar that is found in plants and fruits

high frequency – n. a radio frequency between very high frequency and medium frequency

ultrasound medical noun : a method of producing images of the inside of the body by using a machine that produces sound waves which are too high to be heard

inject – v. to force a liquid medicine or drug into someone or something by using a special needle — often + into

bubble – n. a tiny, round ball of air or gas inside a liquid

vibrate – v. to move back and forth⁷ or from side to side with very short, quick movements

a lot riding on (something) – phrase to be depending on the successful outcome or development of something

beam – n. a line of energy, particles, etc., that cannot be seen

steer – v. to control the direction in which something (such as a ship, car, or airplane) moves

1 skull   

n.头骨；颅骨

参考例句：

• The skull bones fuse between the ages of fifteen and twenty-five.头骨在15至25岁之间长合。
• He fell out of the window and cracked his skull.他从窗子摔了出去，跌裂了颅骨。

2 tumor   

n.（肿）瘤，肿块(英)tumour

参考例句：

• He was died of a malignant tumor.他死于恶性肿瘤。
• The surgeons irradiated the tumor.外科医生用X射线照射那个肿瘤。

3 gateway   

n.大门口，出入口，途径，方法

参考例句：

• Hard work is the gateway to success.努力工作是通往成功之路。
• A man collected tolls at the gateway.一个人在大门口收通行费。

4 glucose   

n.葡萄糖

参考例句：

• I gave him an extra dose of glucose to pep him up.我给他多注射了一剂葡萄糖以增强他的活力。
• The doctor injected glucose into his patient's veins.医生将葡萄糖注入病人的静脉。

5 vessel   

n.船舶；容器，器皿；管，导管，血管

参考例句：

• The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
• You should put the water into a vessel.你应该把水装入容器中。

6 steer   

vt.驾驶，为…操舵；引导；vi.驾驶

参考例句：

• If you push the car, I'll steer it.如果你来推车，我就来驾车。
• It's no use trying to steer the boy into a course of action that suits you.想说服这孩子按你的方式行事是徒劳的。

7 forth   

adv.向前；向外，往外

参考例句：

• The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。