干细胞研究及其伦理学问题

干细胞是动物体内一种独特的基本细胞类型。干细胞分化时,有些成为特殊类型的细胞,另一些仍维持干细胞,准备替代机体衰老和损伤的细胞。这些干细胞本身能够复制,以供机体终生组织更新的需要。最基本的多能干细胞存在于早期胚胎中,科学家们成功分离和培育干细胞的报告,为退行性疾病主损伤甚至致合性疾病的治疗带来了新的希望,然而,与此同时也引起了世界范围的关于使用人类胚胎和死亡胎儿进行研究的伦理大争论。     

Rescuing Human Embryonic Stem Cell Research: The Blastocyst Transfer Method

Despite the therapeutic potential of human embryonic stem (HES) cells, many people believe that HES cell research should be banned. The reason is that the present method of extracting HES cells involves the destruction of the embryo, which for many is the beginning of a person. This paper examines a number of compromise solutions such as parthenogenesis, the use of defective embryos, genetically creating a “pseudo embryo” that can never form a placenta, and determining embryo death, and argues that none of these proposals are likely to satisfy embryoists, that is, those who regard the embryo as a person. This paper then proposes a method of extracting HES cells, what might be called the Blastocyst Transfer Method, that meets the ethical requirements of embryoists, and it considers some possible concerns regarding this method. It concludes by encouraging future HES cell research to investigate this method.     

“Show Me” Bioethics and Politics

Missouri, the “Show Me State,” has become the epicenter of several important national public policy debates, including abortion rights, the right to choose and refuse medical treatment, and, most recently, early stem cell research. In this environment, the Center for Practical Bioethics (formerly, Midwest Bioethics Center) emerged and grew. The Center's role in these “cultural wars” is not to advocate for a particular position but to provide well researched and objective information, perspective, and advocacy for the ethical justification of policy positions; and to serve as a neutral convener and provider of a public forum for discussion. In this article, the Center's work on early stem cell research is a case study through which to argue that not only the Center, but also the field of bioethics has a critical role in the politics of public health policy.     

Towards a Global Human Embryonic Stem Cell Bank

An increasingly unbridgeable gap exists between the supply and demand of transplantable organs. Human embryonic stem cell technology could solve the organ shortage problem by restoring diseased or damaged tissue across a range of common conditions. However, such technology faces several largely ignored immunological challenges in delivering cell lines to large populations. We address some of these challenges and argue in favor of encouraging contribution or intentional creation of embryos from which widely immunocompatible stem cell lines could be derived. Further, we argue that current immunological constraints in tissue transplantation demand the creation of a global stem cell bank, which may hold particular promise for minority populations and other sub-groups currently marginalized from organ procurement and allocation systems. Finally, we conclude by offering a number of practical and ethically oriented recommendations for constructing a human embryonic stem cell bank that we hope will help solve the ongoing organ shortage problem.     

The Potentiality of the Embryo and the Somatic Cell

Recent arguments on the ethics of stem cell research have taken a novel approach to the question of the moral status of the embryo. One influential argument focuses on a property that the embryo is said to possess—namely, the property of being an entity with a rational nature or, less controversially, an entity that has the potential to acquire a rational nature—and claims that this property is also possessed by a somatic cell. Since nobody seriously thinks that we have a duty to preserve the countless such cells we wash off our body every day in the shower, the argument is intended as a reductio ad absurdum of the claim that the embryo should be afforded the same moral status as a fully developed human being. This article argues that this argument is not successful and that it consequently plays into the hands of those who oppose embryonic stem cell research. It is therefore better to abandon this argument and focus instead on the different argument that potentiality, as such, is not a sufficient ground for the creation of moral obligations towards the embryo.     

The Therapeutic Promise of Pluripotency and its Political use in the Italian Stem Cell Debate

Stem cell research is considered one of the most promising branches of contemporary biomedicine. The capacity to develop into almost any cell type of the mature organism—pluripotency—is associated with human embryonic stem cells (hESCs) and is regarded as having great therapeutic potential. Harvesting stem cells destroys the human embryo, however; so research on embryonic stem cells has provoked controversies. In some countries such as Italy, the use of human embryos for research and therapeutic purposes is strictly forbidden. The Italian restrictive regulation has been explained by structural–cultural factors such as religion, but a better explanation lies in the policy dramaturgies deployed in the Italian debate. It was a struggle between two research trajectories—research on hESCs and on adult stem cells—for monopoly over the most credible therapeutic promise. Each was linked to different views of the Italian social order; each was epistemically legitimized by discourses on pluripotency and on the therapeutic potential of different stem cell types. Catholic actors articulated epistemic discourses on the therapeutic promises of different stem cell sources. The battle to define the social order—between a secular and a confessional view—became a struggle between two research trajectories for monopoly over the most credible therapeutic promise. The restrictive regulatory framework resulted from successfully transforming a policy dramaturgy into a new regulatory order. Thus structural–cultural variables such as religiosity matter only through the agency of institutional actors in local political cultures.     

对颌骨骨折坚固内固定术患者心身感受的质性研究

了解颌骨骨折坚固内固定术患者不同阶段的心理和躯体感受,以便为其提供人性化的人文护理服务,使患者满意,使优质护理服务得到落实。采用立意取样法选取研究对象,对选取的31例颌骨骨折坚固内固定术患者采用质性研究中的现象学方法进行深度访谈,并对资料进行整理和分析。结果发现患者在三个阶段中的护理问题如下：（1）手术前;自我形象紊乱、功能障碍和焦虑。（2）手术后：舒适受到影响和愧疚感等。（3）出院时：渴求信息。本研究能规范颌骨骨折坚固内固定术患者人文护理的具体内容,改善其护理问题。     

干细胞制备过程中伦理风险的系统性综述

通过检索国内外6个文献数据库以获取2010年1月~2020年7月干细胞制备伦理风险的文献,并对不同类型干细胞制备过程中存在的伦理风险进行系统性综述。对64篇与干细胞制备伦理风险相关的纳入文献进行分析后发现,干细胞制备过程的伦理风险不仅涉及生物材料供体和组织来源的选择,还涉及干细胞制备各个环节的安全性。鉴于目前干细胞的制备技术尚未成熟,建议干细胞制备过程中应严格控制生物材料供体和组织来源,不断改进制备工艺,控制制备过程质量,以确保人体移植的安全性。

     

肿瘤干细胞与肿瘤治疗

肿瘤可看作是由功能异质性的细胞群体所组成的,具有不定增殖能力的异常器官。最近提出的肿瘤干细胞学说认为肿瘤起源于干细胞,肿瘤生长是肿瘤组织中极少量具有特殊细胞表面标志的肿瘤干细胞增殖的结果。因此治疗的关键应是针对肿瘤干细胞,通过靶向肿瘤干细胞及其异常调节的信号转导通路来治疗肿瘤。这对传统的治疗方式提出了巨大挑战,也为有效地根治肿瘤开辟了新的思路。     

干细胞技术应用于口腔医学的希望与困惑

骨髓干细胞、胚胎干细胞已开始应用于口腔医学领域 ,有关牙髓干细胞、牙周干细胞、牙胚干细胞等研究也取得了一系列重要的进展 ,为治疗口腔疾病开辟了一个新的途径 ,但同时也面临着需要进一步探讨的技术和伦理等方面的问题。