首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Every year, 2,000 American lives are saved by the selflessness of others. These are the bone marrow donors who give the gift of
Every year, 2,000 American lives are saved by the selflessness of others. These are the bone marrow donors who give the gift of
admin
2010-04-24
47
问题
Every year, 2,000 American lives are saved by the selflessness of others. These are the bone marrow donors who give the gift of life to patients fighting deadly diseases such as leukemia, lymphoma, and aplastic anemia. That’s the good news. The bad news is that thousands more die each year because not enough people have signed on to the registries that would help the ill find a suitable match for a transplant.
Bone marrow or stem-cell transplants are usually a last resort, intended for those whose illnesses have not responded to traditional treatments such as chemotherapy or radiation. How do they work? We all store a special type of cell in our bone marrow called stem cells. These primitive cells give rise to the three types of blood cells: red, white and platelets. Everyone’s stem cells have certain genetic characteristics or markers that make them unique from others. Despite this uniqueness, there are some shared characteristics between people. This is important, because a patient’s immune system will reject blood or organs received from someone else if they do not share sufficient similarities.
Family members, especially siblings, are always the first to be considered as donors, because there’s a greater chance that the genetic markers on their cells will have enough in common to prevent rejection after transplantation. In many cases, however, a familial match can’t be found and then the search begins for an unrelated donor. These donors typically come from a pool of people who have already signed up on a donor registry in the event that their cells match a needy recipient.
Once the lab has verified a match between donor and recipient, the next phase starts. The patient is given radiation or chemotherapy to kill the unhealthy cells. Healthy cells are harvested from the donor — either extracted from the pelvic bones or taken from the arm in a way that is similar to having blood drawn — and prepared in a laboratory. Once they’re ready, they’re given to the patient through a vein — the same way as one would receive a blood transfusion. Once these transplanted donor cells get settled within the patient’s bone marrow, they make the healthy red blood cells, white blood cells and platelets necessary to support life.
One of the major problems currently faced by transplant centers is that while bonemarrow transplants can cure more than 70 different diseases, there aren’t enough donors on the registry to treat the more than 3,000 patients awaiting transplants. The National Marrow Donor Program, the largest registry in the country, has approximately 4.8 million adult volunteer donors, but that isn’t nearly enough for the thousands who need transplants.
Why isn’t a pool of more than 4 million donors isn’t enough to cover 3,000 needy patients? Here’s the reason: in the vast-majority of cases, finding a suitable match isn’t easy. Because we are unique individuals with a variety of ancestral backgrounds and integration patterns, finding someone similar to us is a major task. In the end, it comes down to a numbers game — the more potential donors listed on the registry, the greater a chance of finding a match, especially for those with unusual genetic characteristics.
The healthy cells of donors will be transplanted to the patient through ______.
选项
A、pelvic bones
B、arms
C、vein
D、artery
答案
C
解析
细节题。如上题中所述培养好的骨髓会通过静脉注入病人体内,故C正确。
转载请注明原文地址:https://kaotiyun.com/show/7C2K777K
0
专业英语四级
相关试题推荐
Thereseemsnevertohavebeenacivilizationwithouttoys,butwhenandhowtheydevelopedisunknown.Theyprobablycameabout
Itisrefreshingtoseeaninternationalorganizationnotonlysubjectingitselftocriticismbutalsopublishingtheresults.A
TheBigIssuelookslikeageneralinterestpublication.Thiscolourfulfortnightlymagazineisnoordinarymagazine.Itissold
OldAmericansareextremelyreluctanttobuyon______andlikelytosaveasmuchmoneyaspossible.
Venus,oneofthefourinnerplanetsofoursolarsystem,istheclosestbodyintheskyapartfromtheMoon,sometimescomingo
Sincewearesocialbeings,thequalityofourlivesdependsinlargemeasureonourinterpersonalrelationships.Onestrengtho
Americansareproudoftheirvarietyandindividuality,yettheyloveandrespectfewthingsmorethanauniform,whetheritis
Itisusualtoclassifytypesofproductionasjobproduction,batchproductionandflowproduction.Injobproduction,products
随机试题
心肾阳虚型缓慢性心律失常的治疗方法是
痹证与痿证的鉴别,应以下列哪项症状为主
对丙咪嗪作用的叙述哪项是错误的
上能通阳散结以治痰浊胸痹,下能行气导滞以治痢疾里急后重的是
根据《药品说明书和标签管理规定》规定,运输、储藏包装标签没有要求标示
海关审结电子数据报关单后,进出口货物收发货人或其代理人应当自接到海关“现场交单”或“放行交单”通知之日起15日内,持打印的纸质报关单,备齐规定的随附单证并签名盖章,到货物所在地海关提交书面单证并办理相关海关手续。
下列对有效市场假说描述正确的是()。Ⅰ.在市场上的每个人都是理性的经济人,金融市场上每只股票所代表的各家公司都处于这些理性人的严格监视之下Ⅱ.股票的价格反映了这些理性人的供求的平衡,想买的人正好等于想卖的人Ⅲ.股票的价
下列选项中,不属于市场秩序的是()。
2,5,14,29,86,()
Scientistssaytheyhave【B1】______evidencethatjoggingisgoodforpeople.ThislatestEuropeanresearch【B2】______headline-maki
最新回复
(
0
)