揽瓜阁阅读做题小分队 第176天基因治疗

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Myoblasts appear to be good candidates for use in gene therapy because of an unusual and advantageous biological property: when injected into muscle, they fuse with nearby muscle fibers and become an integral part of the muscle tissue. Moreover, since muscle tissue is generally well supplied with nerves and blood, the therapeutic agents produced by the transgene are also accessible to nerves and the circulatory system. Thus, myoblasts may not only be useful for treating muscle disorders such as muscular dystrophy, but also nonmuscle disorders such as neurodegenerative diseases and inherited hormone deficiencies.

In a series of experiments in rodents, a team of investigators has been testing neural stem cells as vehicles for cell-based gene therapy for brain tumors known as gliomas. Gliomas are virtually impossible to treat because the tumor cells readily invade the surrounding tissue and migrate extensively into the normal brain. The researchers genetically modified human neural stem cells to produce a protein, cytosine deaminase, that converts a nontoxic precursor drug into an active form that kills cancer cells. The engineered neural stem cells were then injected into the brains of mice with human-derived gliomas. Within two weeks of the gene therapy and systemic treatment with the precursor drug, the tumors had shrunk by 80 percent. The animal studies also revealed that neural stem cells were able to quickly and accurately "find" glioma cells, regardless of whether the stem cells were implanted directly into the tumors, implanted far from the tumors (but still within the brain), or injected into circulating blood outside the brain.

Another cell-based gene therapy system under investigation involves the use of osteoblasts. In a recent preliminary study examining a gene therapy approach to bone repair and regeneration, researchers genetically engineered osteoblasts to produce a bone growth factor. The osteoblasts were added to a biodegradable matrix that could act as a "scaffold" for new bone formation. Within a month after the cell-impregnated scaffold was implanted into mice, new bone formation was detectable. Although this work is in the very early stages, it offers hope of an effective alternative to conventional bone-grafting techniques.

1. Why does the author mention that muscle tissue is generally well supplied with nerves and blood in the second sentence of the first paragraph?
(A) to offer further proof that the advantageous biological properties of myoblasts distinguish them from osteoblasts
(B) to elaborate upon the hypothesis that myoblasts can be used to treat coronary heart disease
(C) to describe how myoblasts are able to deliver therapeutic agents for the treatment of muscular dystrophy
(D) to provide evidence that myoblasts are truly integrated into the actual fibers of a recipient muscle
(E) to explain how a transgene that binds to muscle fibers can affect — other bodily systems

2. The author of this passage would most likely agree with which of the following statements?
(A) Most cell-based gene therapy systems have only been proven to work on mice and are years away from human trials.
(B) Recent research indicates that cell-based gene therapy may provide new methods of treating multiple disorders and diseases in humans.
(C) There are no gene therapy treatment methods that have been shown to be truly effective in combating gliomas.
(D) Osteoblasts, as indicated by their name, are used exclusively in the treatment of bone injuries and disorders.
(E) Nontoxic precursor drugs generally do not cause significant side effects in recipients.

3. The author suggests that neural stem cells exhibit which of the following traits?
I. the ability to consume gliomas
II. the ability to distribute themselves via the circulatory system
III. the ability to treat brain tumors
(A) I ONLY
(B) II ONLY
(C) I and II ONLY
(D) II and III ONLY
(E)I, II and III

4. The content of the passage leads most naturally to which of the following conclusions?
(A) Myoblast ‘scaffolding’ offers hope to patients currently facing painful bone-grafting operations.
(B) While neural stem cell research may appear promising, ethical debate surrounding it will likely hamper future applications of this new system
(C) Cytosine deaminase effectively reduces brain tumors formed by gliomas.
(D) Researchers are studying several methods of delivering cell-based gene therapy.
(E) Myoblasts offer the most promising mechanism for cell-based gene therapy.

参考答案：EBDD

黄富贵1926

BBDA? 10min, 1介绍了M治疗法2讲了个挺成功的试验3讲了一个还在试验阶段的涉及o的基因治疗

Titi1126

Mark一下！               

clairettt

m的基因治疗（肌肉），特性，可治疗的疾病
神经干细胞的基因治疗（脑瘤），研究的治疗过程，结果有效
o的基因治疗（骨再生），治疗过程
CBBD

123ffff

3种cell-based gene therapy
gene therapy用于M-M和muscle tissue融为一体
利用netrual stem cells治疗gliomas
oste
BBBD

zyycn

主要介绍三种基因疗法。

P1：M很适合基因疗法，一是因为它可以和肌肉长在一起，二是可以和神经、血液循环系统适配。所以M或许可以适用于肌肉disorder以及非肌肉disorder的病症。

P2：科学家研究神经干细胞治愈脑肿瘤G。G很难治愈因为肿瘤细胞侵犯周围组织，而神经干细胞可以产生某种蛋白质杀死这些癌细胞。介绍老鼠实验，确实减小了肿瘤。实验表明神经干细胞可以快速准确找到肿瘤细胞，不管是在脑肿瘤内、脑肿瘤外还是脑外。

P3：介绍O在骨头修复中的作用，像脚手架一样，且动物实验也成功了。因此O疗法未来可能会成为骨头嫁接技术的替代。

CBDD

大月亮cyn

Day176
文章大概结构：Gene therapy 1. Myoblasts 2. Neural stem cells 3. Osteoblasts
Gene therapy 1. Myoblasts --> muscle (nerves & blood) --> nerves & circulatory system --> treat muscle disorders & nonmuscle disorders
Gene therapy 2. Neural stem cells --> CY converts drug active kill cancer --> find G cells + treat brain tumors (G)
Gene therapy 3. Osteoblasts -->added to B matirix act as new bone formation --> treat bone repair & regeneration

1. E 解释M能treat nonmuscle disorders ; nerves and circulatory system = other bodily systems
2. B new methods of treating multiple disorders and diseases in humans 文章讲了三个
3. D I 不是neural stem cell consume G ；是CY刺激drug active kill G
4. D 三个cell-based gene therapy

断了的弦

BBEC

斯麦尔糖

cbbd

Alan-Endless

看一下！