Ethical boundary-work in the embryonic stem cell laboratory

Most accounts of the ethics of stem cell research are de- contextualised reviews of the ethical and legal literature. In this chapter we present a socially embedded account of some of the ethical implications of stem cell research, from the perspectives of scientists directly involved in this area. Based on an ethnography of two leading embryonic stem cell laboratories in the UK, our data form part of the findings from a larger project mapping the scientific, medical, social and ethical dimensions of innovative stem cell treatment, focusing on the areas of liver cell and pancreatic islet cell transplantation. We explore three key issues: what individual scientists themselves view as ethical sources of human embryos and stem cells; their perceptions of human embryos and stem cells; and how scientists perceive regulatory frameworks in stem cell research. We argue that these dimensions of laboratory practice are all examples of 'ethical boundary-work', which is becoming an integral part of the routine practice and performance of biomedical science. Our work adds to the relatively few sociological studies that explore ethics in clinical settings and to an even smaller body of work that explores scientists' views on the ethical issues relating to their research.     

The importance of the use of stem cells for public health

Stem cells were elected 'Breakthrough of the Year' by Science(1) magazine in 1999, having shown that stem cells from adult tissues retained the ability to differentiate into other tissue types. During the previous year, the first human embryo stem cell lines were established. Since then, the number of scientific papers on stem cells has been increasing exponentially, establishing new paradigms that are rapidly challenged by subsequent experiments. This paper reviews the stem cell research field, divided into two groups: embryo and adult stem cells. While the differentiation potential of the former is well characterized in mice and humans, their use in cell therapy and research has been hampered by histocompatibility, safety and ethical issues. In contrast, adult stem cells do not present these problems. However, the extent of their plasticity is still under investigation. Nevertheless, numerous clinical trials in humans are under way, mainly with stem cells derived from bone marrow. This paper discusses discuss the importance of working with both classes of human stem cells in order to fulfill the promise of stem cell therapies.     

International perspectives on the ethics and regulation of human cell and tissue transplantation

The transplantation of human cells and tissues has become a global enterprise for both life-saving and life-enhancing purposes. Yet current practices raise numerous ethical and policy issues relating to informed consent for donation, profit-making, and quality and safety in the procurement, processing, distribution, and international circulation of human cells and tissues. This paper reports on recent developments in the international debate surrounding these issues, and in particular on the attention cell and tissue transplantation has received in WHO's ongoing process of updating its 1991 Guiding principles on human organ transplantation. Several of the organizers of an international working group of stakeholders from a wide range of backgrounds that convened in Zurich in July 2006 summarize the areas of normative agreement and disagreement, and identify open questions regarding facts and fundamental concepts of potential normative significance. These issues must be addressed through development of common medical, scientific, legal and ethical requirements for human cell and tissue transplantation on a global basis. While guidance must accommodate the distinct ethical issues raised by activities involving human cells and tissues, consistency with normative frameworks for organ transplantation remains a prime objective.     

Stem cell research: licit or complicit? Is a medical breakthrough based on embryonic and fetal tissue compatible with Catholic teaching?

In November 1998 biologists announced that they had discovered a way to isolate and preserve human stem cells. Since stem cells are capable of developing into any kind of human tissue or organ, this was a great scientific coup. Researchers envision using the cells to replace damaged organs and to restore tissue destroyed by, for example, Parkinson's disease, diabetes, or even Alzheimer's. But, since stem cells are taken from aborted embryonic and fetal tissue or "leftover" in vitro embryos, their use raises large ethical issues. The National Institutes of Health (NIH) recently decided to fund research employing, not stem cells, but "cell lines" derived from them. The NIH has essentially made an ethical determination, finding sufficient "distance" between cell lines and abortion. Can Catholic universities sponsoring biological research agree with this finding? Probably not. In Catholic teaching, the concept of "complicity" would likely preclude such research. However, Catholic teaching would probably allow research done with stem cells obtained from postpartum placental tissue and from adult bone marrow and tissue. These cells, which lack the pluripotency of embryonic and fetal stem cells, are nevertheless scientifically promising and do not involve the destruction of human life.     

Cellular therapy--the possible future of regenerative medicine

Stem cells are a unique cell population capable of self-renewal and differentiation into different cell lines. There are two main types of stem cells: embryonic stem cells (pluripotent) and somatic/adult stem cells (multipotent cells differentiated into the specific types of the tissue they originate from). Scientists are now interested in finding the sources of cells that can be used for therapeutic cloning as a method of saving human life and a new trend in regenerative medicine. Reproductive cloning, which aims at creating genetically identical human beings, is prohibited and is subject to national legislation in each country. Mesenchymal stem cells, with their capability to elude detection by the host's immune system and their relative ease of expansion in culture, are a very promising source of stem cells for regenerative medicine. This is the vast potential of cellular therapy for treating damaged and degenerating tissues.     

Use of genomics in toxicology and epidemiology: findings and recommendations of a workshop

The sequencing of the human genome has revolutionized biology and led to an astounding variety of technologies and bioinformatics tools, enabling researchers to study expression of genes, the function of proteins, metabolism, and genetic differences within populations and between individuals. These scientific advances are making an impact in the medical research community and hold great promise for prevention, diagnosis, and treatment of diseases. This developing field also holds great promise for improving the scientific basis for understanding the potential impacts of chemicals on health and the environment. A workshop sponsored by the International Council of Chemical Associations was held to review the state of the science in the application of genomics technologies in toxicology and epidemiology. Further, consideration was given to the ethical, legal, and regulatory issues and their influence on the direction and application of genomics technologies to environmental health research. Four overarching themes emerged from the workshop: Genomics technologies should be used within a framework of toxicology and epidemiology principles and applied in a context that can be used in risk assessment; effective application of these technologies to epidemiology will require suitable biologic samples from large and diverse population groups at the relevant period of exposure; ethical, legal, and social perspectives require involvement of all stakeholder communities; and a unified research agenda for genomics technologies as applied to toxicology, epidemiology, and risk assessment is urgently needed for the regulatory and scientific communities to realize the potential power and benefits of these new technologies.     

诱导多潜能性干细胞的研究现状与临床应用前景

胚胎干细胞可作为细胞替代治疗中很好的供体细胞来源。但由于伦理学的原因,限制了胚胎干细胞在细胞替代治疗中的应用前景,而诱导多潜能性干细胞(induced pluripotent stem cell,iPS细胞)的出现则提供了一种替代胚胎干细胞的多潜能性细胞。因为iPS细胞的建立不需要卵细胞,也不破坏发育中的胚胎,所以iPS细胞不涉及伦理学问题。而且iPS细胞的建立相对简单,重复性好。因此,iPS细胞在细胞替代治疗和再生医学中有着广泛的应用前景。本文将回顾iPS细胞技术发展的历史,介绍现有的建立iPS细胞的不同方法和评估iPS细胞质量的手段,展望iPS细胞在细胞替代治疗上有待解决的问题和应用前景。     

Somatische Stammzellen Grundlagen, Konzepte und Herausforderungen

Adult stem cells are multipotent cells that have the ability to self-renew and to differentiate into highly specialized cells. Differentiation of specific cells is not limited to early embryonic development. It also takes place within the adult organism. Adult stem are found in tissues and organs showing a high turn-over rate such as blood, skin or intestine. Moreover, tissues like liver or skin are able to regenerate after injury, indicating the presence of stem cells within these organs. Whereas blood stem cells are already used in transplantation medicine, the biology and therapeutic potential of stem cells isolated from other tissues are still under investigation. Currently, research is focused on the identification and analysis of the factors regulating stem cell self-renewal and differentiation. A better understanding of stem cell biology certainly will lead to new therapeutic concepts, i.e. the use of stem cells and/or their derivatives as replacement cells to treat diseases including for example diabetes, Parkinson's disease, spinal cord injury, stroke, burns, rheumatoid arthritis.     

干细胞与环境毒理学Ё

近年来,干细胞由于其在生物医药方面的巨大应用前景而成为科学研究的新热点。干细胞具有自我更新的能力,可以在体外进行培养并持续保持未分化状态,在一定条件下能够分化为机体的各种组织器官。因此干细胞正逐渐成为研究环境毒物对机体损伤的新工具,通过建立干细胞体外模型和体内组织干细胞研究相结合的方法可以进行环境毒物的早期危险度评测,寻找新的生物标志物,明确环境中的各种物质对机体的影响机制。本文综述报道各类干细胞及其在环境毒理学研究中的应用近况。     

Therapeutic cloning in debate]

Human embryos can be conceived by cell nuclear transfer in order to isolate human embryonic stem cells (hES cells) for research into autologous cell therapy (therapeutic cloning). However, this technique broaches the major ethical problem concerning the instrumental use of human preimplantation embryos. From the viewpoint of subsidiarity, it is argued that various potential alternatives for therapeutic cloning should first be investigated further. The question as to whether therapeutic cloning should be allowed only becomes apparent when research with surplus embryos obtained in the course of in-vitro fertilization suggests that usable transplants can be obtained in vitro from hES cells, and when the potential alternatives for therapeutic cloning are either less promising or need more time for development than is currently expected.     

Health charities, unethical research and organizational integrity

Organizations, particularly Catholic hospitals, schools and social service agencies, should re-examine their relationships to health and medical charities promoting unethical research such as human embryonic stem cell research and therapeutic cloning. Part 6 of the Ethical and Religious Directives provides a helpful framework for ethical analysis and action.     

Embryonic stem cells in companion animals (horses, dogs and cats): present status and future prospects

Reproductive technologies have made impressive advances since the 1950s owing to the development of new and innovative technologies. Most of these advances were driven largely by commercial opportunities and the potential improvement of farm livestock production and human health. Companion animals live long and healthy lives and the greatest expense for pet owners are services related to veterinary care and healthcare products. The recent development of embryonic stem cell and nuclear transfer technology in primates and mice has enabled the production of individual specific embryonic stem cell lines in a number of species for potential cell-replacement therapy. Stem cell technology is a fast-developing area in companion animals because many of the diseases and musculoskeletal injuries of cats, dogs and horses are similar to those in humans. Nuclear transfer-derived stem cells may also be selected and directed into differentiation pathways leading to the production of specific cell types, tissues and, eventually, even organs for research and transplantaton. Furthermore, investigations into the treatment of inherited or acquired pathologies have been performed mainly in mice. However, mouse models do not always faithfully represent the human disease. Naturally occurring diseases in companion animals can be more ideal as disease models of human genetic and acquired diseases and could help to define the potential therapeutic efficiency and safety of stem cell therapies. In the present review, we focus on the economic implications of companion animals in society, as well as recent biotechnological progress that has been made in horse, dog and cat embryonic stem cell derivation.     

Mesenchymal stem cell; history, biology and clinical application

In the last years, stem cells have drawn the attention of various sectors of society for many reasons. From the basic point of view, stem cells represent an ideal model to study cell differentiation and self-renewal mechanisms. However, their potential in cell therapy and regenerative medicine has triggered the increasing amount of knowledge in this area. Mesenchymal stem cells belong to the select group of adult stem cells. They have differentiation potential towards mesenchymal tissues such as bone, cartilage, stroma and fat. Recently, both in vivo and in vitro reports have shown a greater plasticity of mesenchymal stem cells, showing not only a mesenchymal cell fate but also those leading to endothelial, nervous and muscular lineages. For these reasons, the study of mesenchymal stem cells has gained great interest and many articles have been published. In the present review, we have presented a global vision of this topic, including its history, biologic features, sources, isolation methods and an overview on their clinical application.     

人胚胎干细胞建系研究中的伦理管理

目的：建立国人胚胎干细胞系递交国际干细胞库,并在此基础上建立既符合中国国情又得到国际认可的相关伦理管理体系。方法：在比尔盖茨基金会的资助下,与北京大学生命科学院再生生物学实验室合作,募集胚胎建立人胚胎干细胞系,在此过程中探讨可行的符合国际伦理原则的相关伦理管理机制。结果：成功建立了国人胚胎干细胞系及相关伦理管理体系。结论：进行干细胞研究时应充分重视伦理问题,国际干细胞伦理管理与中国相关伦理原则是可以有机结合的。     

人胚胎干细胞建系研究中的伦理管理

目的：建立国人胚胎干细胞系递交国际干细胞库,并在此基础上建立既符合中国国情又得到国际认可的相关伦理管理体系。方法：在比尔盖茨基金会的资助下,与北京大学生命科学院再生生物学实验室合作,募集胚胎建立人胚胎干细胞系,在此过程中探讨可行的符合国际伦理原则的相关伦理管理机制。结果：成功建立了国人胚胎干细胞系及相关伦理管理体系。结论：进行干细胞研究时应充分重视伦理问题,国际干细胞伦理管理与中国相关伦理原则是可以有机结合的。     

Herbal medicine research and global health: an ethical analysis

Governments, international agencies and corporations are increasingly investing in traditional herbal medicine research. Yet little literature addresses ethical challenges in this research. In this paper, we apply concepts in a comprehensive ethical framework for clinical research to international traditional herbal medicine research. We examine in detail three key, underappreciated dimensions of the ethical framework in which particularly difficult questions arise for international herbal medicine research: social value, scientific validity and favourable risk-benefit ratio. Significant challenges exist in determining shared concepts of social value, scientific validity and favourable risk-benefit ratio across international research collaborations. However, we argue that collaborative partnership, including democratic deliberation, offers the context and process by which many of the ethical challenges in international herbal medicine research can, and should be, resolved. By "cross-training" investigators, and investing in safety-monitoring infrastructure, the issues identified by this comprehensive framework can promote ethically sound international herbal medicine research that contributes to global health.     

Humane embryonale Stammzellen

The remarkable capability of human embryonic stem cells (hES cells) to differentiate into all somatic cell types and tissues opens promising perspectives for the development of novel therapeutic approaches for neurological disorders. This article provides an overview on the current state of research in this field. We present strategies and results on the generation of selected neural subtypes (dopaminergic neurons, retinal progenitors, motoneurons, oligodendrocytes) and discuss problems and risks associated with a potential clinical application of this novel cell source.     

Isolation and therapeutic use of human stem cells

Nowadays, adult stem cells are the main target of biological research. Stem cell specific markers allow the extraction in enough quantity and high purity of multipotent cells from organic tissues, and their usage instead of the ethically reprehensible embryonal stem cells in experimental therapeutic purposes is also possible. The key point in the development of a new, stem-cell based therapeutic methodology is the determination of stem cell specific cell surface or cytoplasmatic antigens that makes reliable stem cell identification possible. Bone marrow derived multipotent stem cells can already be suitably identified, and other, more or less organic tissue-derived stem cell specific markers are also available. The first therapeutic interventions have been already done in diseases such as myocardial infarction or diabetes mellitus, and led to promising results.     

Air pollutants and sources associated with health effects

This paper provides four complementary perspectives on the understanding of the risk posed to health by particular sources of air pollution. These perspectives are based on contributions to a plenary session "Pollutants and Sources Associated with Health Effects" at the American Association for Aerosol Research meeting. Research that advanced understanding of source impacts is critical to the prospects for more refined air quality management that moves from the pollutant-oriented approaches in place for the "criteria pollutants" to more targeted strategies. Such research will also be needed in support of multipollutant air quality management strategies. Here, after beginning with a discussion of mobile sources (Ayala), we provide brief historical summaries of relevant research and future research directions framed around the core scientific research disciplines: exposure sciences (Brauer), toxicology (Mauderly) and epidemiology (Samet). Overall, we find that the overarching most important need is to "put the regulatory cart behind the research horse", in the sense that the focus of research, funding permitting, should not be limited to supporting existing air quality regulations. We suggest that more informative research can be carried out using increasingly sophisticated tools and drawing on advancing biological knowledge. However, these tools need to be used and managed in an appropriate framework.