Cures and Clones.doc_第1页
Cures and Clones.doc_第2页
Cures and Clones.doc_第3页
Cures and Clones.doc_第4页
全文预览已结束

下载本文档

版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领

文档简介

Cures and Clones: Stem Cells in the Newsby Chana Palmer, Stanford University For millions of people around the world, stem cells offer the only glimmer of hope for a cure to their disease. Stem cells are a special type of cell that many scientists believe may one day be able to help correct many conditions previously thought incurable from leukemia to paralysis to Parkinsons. In fact, some types of stem cells are already being used successfully to help treat children with certain rare diseases. Illustration by Sue Medaris/UW-Madison University Communications.Courtesy of UW-Madison, Embryonic Stem Cells homepageIf stem cells have such potential to relieve suffering, why are so many people so upset about their use? The reason is that the most powerful type of stem cell embryonic stem (ES) cells can only be obtained from human embryos. Many people think that its wrong to create and destroy human embryos to treat disease. What makes a stem cell so special and so powerful? There are two important ways in which stem cells are different from other cells in your body. The first is that they are unspecialized this means that they dont have a specific job yet, and can take on any one of many specialized jobs later in their life. In this way, stem cells are like high school students who have yet to decide on their career and have the potential to be anything, whereas the rest of the cells in your body are already professionals. The second important quality of stem cells is that they can keep growing and making copies of themselves for many years. Here, again, stem cells are like teenagers they can have many children over many years - whereas most cells in the body are like middle-aged adults with only a few fertile years left. Are all stem cells the same? No, in fact there are several quite different types of stem cells. The types differ by where they are in the body and by what they can become. The most important distinction to make is between adult stem cells and embryonic stem cells. Adult stem cells are found in adults and children while embryonic stem cells (not surprisingly) are found ONLY in embryos. Embryonic stem cells are the most flexible and potentially useful type of stem cell. Unlike adult stem cells, which have a limited range of careers available to them, embryonic stem cells can turn into almost any cell type: blood, heart, liver, bone ES cells are child prodigies! Unfortunately, ES cells are also the most difficult to obtain both practically and ethically. Below are two articles describing current advances in stem cell research. One of the articles tells a success story in the US for the use of umbilical cord stem cells in treating heart disease and the other reports an advance by South Korean scientists in cloning a human embryo and obtaining human ES cells.More Information To learn more about stem cellsStem cells proven to treat heart damageFor the first time ever, scientists were able to show that stem cells from a healthy donor babys blood can transform into the specialized cell type that a patient needs. The patient was a four-year old boy with Sanfilippo Syndrome B, a rare disease which, when left untreated, results in liver, heart and brain failure. The boy was given healthy stem cells from the blood of a baby girl in the hopes that once inside the boys body, the healthy stem cells would keep his vital organs from failing. Even though the boy eventually died from infection (one of the common risks associated with transplants), doctors were able to show for the first time that some of the girls healthy cells had settled in the boys heart and transformed themselves into fully functional heart cells.Notably, blood stem cells have been used for years to treat children with liver, brain and heart problems. It was suspected that donor stem cells were transforming themselves into the needed cell types, but until this study, this phenomenon had never been proven. The study was conducted by a team or researchers at the Duke Comprehensive Cancer Center. Kirsten Crapnell, Ph.D will present the teams findings at the International Association of Bone Marrow Transplantation Research meeting Feb. 12-17 in Orlando, Florida. More Information Cord Blood Cells Proven to Differentiate Into Heart Muscle, Brain CellsHuman embryo created by cloningSay it aint so, Joe! Or should I say Hwang Woo Suk? Unfortunately, the results we talk about in this part of the article have been shown to be false. Investigations are currently ongoing to see if the data was deliberately falsified.The ideas still stand and one day scientists will do what Hwang Woo Suk has claimed he has done. It will be just a matter of timethank goodness science is self correcting!Scientists in South Korea announced the creation of the first cloned human embryos, an exciting but scary advance in human cloning technology. The embryos are genetically identical to their mother/donor and were created for the sole purpose of using their embryonic stem cells for medical research and therapy. Embryonic stem cells can only be found in embryos and, because they can transform themselves into just about any cell type, have the potential to treat or cure many different human diseases. This type of cloning therapeutic cloning should not be confused with reproductive cloning the creation of cloned embryos to be grown into full term babies. The embryos were created by removing the nucleus (DNA) from eggs of volunteering women, and injecting the nucleus (DNA) from one of their adult cells back into their egg. This procedure has

温馨提示

  • 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
  • 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
  • 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
  • 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
  • 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
  • 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
  • 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

评论

0/150

提交评论