2.Since the start of the deadly AIDS epidemic in the 1980s,scientists have been working towards a cure.Now,they may be close to finding one.
Researchers have developed a method to cut the viral (病毒) DNA from a person's infected cells.It is called CRISPR/Cas9and it means the person could be virus-free.
DNA is a substance that carries genetic information in the cells of animals and plants.
This gene-editing took place in a scientific lab,but has not been tested on humans yet.
"It's a big step,"said Kamel Khalili,Ph.D.He is lead researcher and chair at the Department of Neuroscience at Temple University in Philadelphia,Pennsylvania.He and his team made the discovery.
But more tests have to be done to know if it will be a cure for the millions of patients infected with the HIV virus,which causes AIDS.
Antiretroviral drugs have been doing a good job of keeping the AIDS virus from reproducing.Such a good job that levels of HIV are just about undetectable in infected people who take the medicine.
But even with the drugs,the virus stays in the body's"T-cells,"which are T-lymphocytes.AIDS damages the immune system,hurting the body's ability to fight off disease.
So the drugs are kind of a"Band-Aid solution,"Khalili explained.They keep the virus from growing.But they do not remove the memory of the virus from the cells.
And,the moment antiretroviral drugs are stopped,the HIV comes back to life and begins making more HIV,which is the AIDS virus.
Khalili and his team of scientists appear to have found a way to cut this viral DNA from infected people's cells.
In their lab,they took cells from people infected with the HIV virus.They removed the part of the cell that was holding the virus.
He said they had"in some cases,near 90percent of the virus replication (復制) or production dropped in the patient samples after treatment in the laboratory."
Khalili and his team have not actually cured any patients yet.However,he believes this gene-editing technology could possibly cure AIDS.
"Removal of the virus can lead to the cure."He said,"it's an exciting time,and the reason is the technologies are available and the methods are in place and our knowledge has increased."
"And hopefully,there will be funding to take us toward this exciting moment for developing the cure strategy by getting rid of viral DNA using editing techniques."
62.The newly found way is intended to cure AIDS byB.
A.doing damage to the immune system
B.removing viral DNA from infected cells
C.doing research into antiretroviral drugs
D.taking cells from those infected with the HIV virus
63.What can we know about antiretroviral drugs from the passage?C
A.They are likely to make more AIDS virus.
B.They can help body to fight against disease.
C.They are unable to cure people of their HIV virus.
D.Virus will disappear from T-cells because of them.
64.Kamel Khalili's words in the last two paragraphs indicate thatD.
A.his new method is bound to be a perfect cure for AIDS
B.antiretroviral drugs will be dropped in the near future
C.their discovery has made great contributions to human beings
D.they will succeed curing AIDS if they aren't lacking in money.