1 . Desperately ill and seeking a miracle, David Bennett Sr. took the last bet on Jan. 7. when be became the first human to be successfully transplanted with the heart of a pig. “It creates the beat; it creates the pressure; it is his heart,” declared Bartley Griffith, director of the surgical team that performed the operation at the University of Maryland Medical Center.
Bennett, 57, held on through 60 tomorrows, far longer than any previous patient who’d received a heart from another species. His remarkable run offered new hope that such procedures, known as xenotransplantation (异种移植), could help relieve the shortage of replacement organs, saving thousands of lives each year.
The earliest attempts at xenotransplantation of organs, involving kidneys from rabbits, goats, and other animals, occurred in the early 20th century, decades before the first successful human-to-human transplants. Rejection, which occurs when the recipient’s body system recognizes the donor organ as a foreign object and attacks it, followed within hours or days. Results improved after some special drugs arrived in the 1960s, but most recipients still died after a few weeks. The record for a heart xenotransplant was set in 1983, when an infant named Baby Fae survived for 20 days with an organ from a baboon (狒狒).
In recent years, however, advances in gene editing have opened a new possibility: re-edit some genes in animals to provide user-friendly spare parts. Pigs could be ideal for this purpose, because they’re easy to raise and reach adult human size in months. Some biotech companies. including Revivicor, are investing heavily in the field. The donor pig was offered by Revivicor from a line of animals in which 10 genes had been re-edited to improve the heart’s condition. Beyond that, the pig was raised in isolation and tested regularly for viruses that could infect humans or damage the organ itself.
This medical breakthrough provided an alternative for the 20% of patients on the heart transplant waiting list who die while waiting or become too sick to be a good candidate.
1. What does the underlined word “run” in paragraph 2 refer to?| A．Donating his heart to a patient. |
| B．Performing the heart operation. |
| C．Living for 60 days after the operation. |
| D．Receiving a new heart from a pig. |
| A．Its history. | B．Its procedure. | C．Its consequence. | D．Its significance. |
| A．Their growth rate and health condition. |
| B．Their life pattern and resistance to viruses. |
| C．Their easiness of keeping and rapid growth. |
| D．Their investment value and natural qualities. |
| A．It introduced new medications to prevent organ rejection. |
| B．It proved the potential for using organs from various animals. |
| C．It guaranteed a sufficient supply of donor pigs for transplants. |
| D．It offered a prospect of replacement organs through gene editing. |
2 . Researchers reported a blind man who had received a gene of a light-sensing protein can now see and touch objects with the help of special goggles(护目镜).
His vision gains are modest—he cannot see colors or distinguish faces or letters. But if the treatment helps other study participants, it may offer advantages over other vision technologies for severely blind people. For scientists, the result is a milestone: the first published report of using a relatively new technology called optogenetics(光遗传学) to treat a disease in people. “It’s not the kind of vision people dream of, but it’s a big step,” said Jean Bennett of the University of Pennsylvania.
Optogenetics uses light to control neurons. Scientists add the gene to a light-sensitive protein called opsin(视蛋白) from algae or bacteria and then shine light on the cell to cause the opsin to change shape, which switches the neuron’s activity on or off. Since it was developed nearly 20 years ago, optogenetics has mostly been used as a tool to treat animals, brain diseases. But researchers hope it can one day treat diseases such as Parkinson’s disease and blindness.
“The eye is the simplest place to start because it is small and easy to access,” said Botond Roska, a physician-scientist at the University of Base.
The patients in the study have lost the retinal photoreceptor cells(视网膜感光细胞) that use human opsins to turn light into electrical signals relayed to the brain. But their eyes still have the cells that route these signals to the brain via the optic nerve. That means the patients could potentially gain vision by giving these cells a new kind of opsin.
1. What can we know about the result from paragraph 2?| A．It has shortcomings but is important. |
| B．It can be used to treat blind people now. |
| C．It is the conclusion of previous research. |
| D．It is a way to help people become modest. |
| A．New goggles. | B．Suitable opsin. |
| C．Natural proteins. | D．Retinal photoreceptor cells. |
| A．It can benefit both humans and animals. |
| B．Scientists have never focused on it before. |
| C．If has been used to treat animals’ blindness. |
| D．Patients should know something about it. |
| A．A Report on a New Protein |
| B．Ways to Help Patients Stay Healthy |
| C．Researchers Find Blindness Can Be Cured |
| D．A Treatment Helps Blind Men Regain Some Vision |
