1. The ship’s captain seemed to be losing his mental balance. Fearing that he might become completely insane, the crew held a clandestine meeting to discuss what to do in that…………...
2. The new environment friendly project is intended to……………, not to replace, local authorities’ programs.
3. The doctor …………d Rick for not following her advice about switching to a low-fat diet.
4. To an allergic person, foods that are normally…………., such as milk or wheat, can cause discomfort and even serious illness.
5. Many find the thought of a masochist seeking out and enjoying suffering to be as ………….. as the idea of causing someone else to suffer.
6. At first new ideas and theories sound……………... It takes time and effort to comprehend them.
7. We all have our little……………..
8. I’ve been working at the daycare center only one week, so this suggestion may be……………., but I think the center’s program should encompass activities geared to shy children as well as ones for gregarious kids.
9. The scientist’s explanation of the greenhouse effect was so ………… that the entire audience was able to grasp it.
10. The prognosis for Dale’s arthritis is not encouraging. Her doctor didn’t equivocate but told her frankly that in time it may…………………her completely.
11. Scientists need to be …………. in their calculations.
12. Professor ……………. the released data saying that they need verification.
B Genetic Engineering
Read the article.
Full Stem Ahead
Based on the articleby Tom Jacobs
Preposterous as it may seem today, chances are someday you will need replacement tissue. More than 150,000 people worldwide are waiting for an organ. Doctors perform 3 million cardiovascular procedures a year and 2.5 million bone and plastic reconstructive surgeries. At least 200,000 people suffer from spinal-cord injury. One million have Parkinson's disease; 4.7 million experience congestive heart failure, and 400,000 to 800,000 diabetic foot ulcers, which most commonly incapacitate elderly patients, are treated annually. The conclusion derived from this brief overview is lucid: this is a market screaming for products, and demand goes up each year.
It’s only evident that meticulous research necessitating huge investments should precede before this demand is satisfied.
And what will be the prize for companies whose biotechnologies meet the need? Joseph Vacanti and Robert Langer, tissue-engineering pioneers at Harvard and MIT, respectively, put the potential market as high as $80 billion a year. But they say it is too presumptuous to evaluate financial benefits as it may take as long as three decades to move from today, when the ability to perform transplants is limited by organ availability and tissue rejection, to a time when engineered tissue and organs are widely available and perhaps even grown from a person's own cells.
Executives are betting entire companies on which technologies will succeed first and biggest. Some hope for nearer-term success in engineering artificial skin and bone using live cells. Others are developing animal tissue for routine transplant to humans. The largest payoff may go to those who ultimately engineer human growth factors to repair or regenerate tissue in humans or in the lab for transplants.
The results we have had in this sphere so far however repudiate the possibility of unlimited tissue repair and replacement organs in the near future. So before you invest in Bio-utopia, you should look at what's already here in the rapidly emerging field of biomaterials.
Artificial skin, bone and cartilage. Contrary to industry claims, the first biomaterials on the market are not living tissue but artificial products composed of some living cells. These include Organogenesis's skin substitute called Apligraf, made from neonatal foreskin cells— which is certainly repugnant to hear - and two products from Advanced Tissue Sciences, Dermagraft (not yet approved in the United States, but sold abroad) and Trans-Cyte. Both are designed to heal chronic wounds like venous ulcers and diabetic foot ulcers that persist from other causes such as infection, inadequate blood circulation or malnutrition. Curis, meanwhile, is testing and seeking approval of two other biomaterials: OP-1, to mend nonhealing fractures and speed recovery from other bone injuries; and Chrondrogel, for cartilage repair.
Animal tissue. (Warning: this section is not recommended for fans of "Charlotte's Web.") To increase the replacement-tissue supply and reduce or eliminate host rejection, Alexion Pharmaceuticals and Geron Corp. have turned to genetically engineered pigs. These animals offer fast growth, large litters and organ size similar to humans'. Geron's expertise comes from its 1999 purchase of Roslin Bio-Med, the Scottish company whose cloning techniques helped produce Dolly the sheep. Armed with that biotechnology, Geron is competing with Alexion to engineer pigs without the gene that causes human-host tissue rejection. The temporary goal: "bridge" transplants until human organs become available, especially for the 150,000 people hospitalized annually for liver disease. Also Organogenesis is lab-testing a system based on pig-liver cells that provides liver function until or instead of transplantation.
Stem cells and protein growth factors. Many companies believe that the key to restoring or regenerating tissue is to use the body's natural functions. They are trying to re-create the conditions that support the growth of cells and tissue, and harness the body's ability to repair damage caused by disease, trauma or age. To do this and to avert any contingency, they research and test stem cells and human protein growth factors.
Researchers have shown in the lab that stem cells from human embryos can differentiate into almost every kind of cell in the body, possibly enabling the generation of complete organs. The result could be relief from conditions as varied as Parkinson's disease to spinal injury. That's why the National Institutes of Health (NIH) last August announced federal funding for human embryonic stem-cell research. Because of Congress's 1996 ban on such funding where human embryos are specifically destroyed, the NIH's new guidelines require that grantees obtain specimens discarded from in vitro fertilization clinics or other private sources.
Despite continued chiding from groups opposed to embryo research—the Bush administration is reviewing the guidelines—the NIH decision turned investors' attention to companies such as Geron, which has worked for years to develop biotechnology to harvest human embryonic stem cells, grow them in sufficient quantities, urge their differentiation into particular cells from skin to heart and nerve, and make them work in the body. At the same time, Human Genome Sciences thinks it can advance stem cells' promise by isolating the signaling protein that can cause them to differentiate into the desired tissue. Curis and others are working with adult stem cells, despite the prevailing view on their foibles: they are not as powerful as those contained in embryos. But adult stem cells, found primarily in skin and bone marrow, offer two advantages: the supply is greater, and the research doesn't invite political objections which can be far from innocuous and even precipitate the halt of the project.
Therapeutic protein growth factors may offer another route to growing and repairing tissue throughout the body, complementing the previous techniques. Human Genome Sciences is moving to phase II trials of the protein repifermin, which has shown positive results in treating venous ulcers and is also being tested for mucosal tissue injuries common in chemotherapy. Joining Human Genome Sciences, companies such as biotechnology pioneer Genen-tech and privately held ZymoGenetics work hard to identify, test and patent therapeutic proteins that can repair or regenerate human tissue.
What's an investor to do in this context? Biomaterials is a complex industry, with potentially great rewards well into the future. But you need to have patience and look to the very long term. And the risks are considerable. This is not investing for the faint of heart.