Hematopoietic stem cell transplantation is a widely accepted practice in the United Kingdom (UK). The relatively liberal UK law permits donation both within families and from strangers, and even allows the creation of “saviour siblings” who are brought into being with the specific intent of having them donate stem cells to save other members of their family. This chapter describes the regulation of HSCT in the UK and highlights some ethical issues related to discrimination against some (...) categories of potential donors, the accuracy of the information provided to potential donors, and the controversy concerning saviour siblings. (shrink)

Hematopoiesis unfolds within the bone marrow niche where hematopoietic stem cells (HSCs) play a central role in continually replenishing blood cells. The hypoxic bone marrow environment imparts peculiar metabolic characteristics to hematopoietic processes. Here, we discuss the internal metabolism of HSCs and describe external influences exerted on HSC metabolism by the bone marrow niche environment. Importantly, we suggest that the metabolic environment and metabolic cues are intertwined with HSC cell fate, and are crucial for hematopoietic (...) processes. Metabolic dysregulation within the bone marrow niche during acute stress, inflammation, and chronic inflammatory conditions can lead to reduced HSC vitality. Additionally, we raise questions regarding metabolic stresses imposed on HSCs during implementation of stem cell protocols such as allo‐SCT and gene therapy, and the potential ramifications. Enhancing our comprehension of metabolic influences on HSCs will expand our understanding of pathophysiology in the bone marrow and improve the application of stem cell therapies. (shrink)

Background: Hematopoietic stem cell transplantation is a potential cure for a range of life-threatening diseases, but is also associated with a high mortality rate. Nurses encounter a variety of situations wherein they are faced with discussing bad news with hematopoietic stem cell transplantation patients. Research objective: The aim of this study was to explore the experiences and strategies used by Iranian nurses related to truth-telling and communicating bad news to hematopoietic stem (...) class='Hi'>cell transplantation patients. Research design: A qualitative approach using content analysis of interview data was conducted. Participants and research context: A total of 18 nurses from the main hematopoietic stem cell transplantation center in Iran participated in semi-structured interviews. Ethical considerations: The Institutional Review Board of the Tabriz University of Medical Sciences and the Hematology-Oncology and Stem Cell Transplantation Research Center affiliated with the Tehran University of Medical Sciences approved the study. Findings: In the first main category, not talking about the disease and potential negative outcomes, the nurses described the strategies of not naming the disease, talking about the truth in indirect ways and telling gradually. In the second main category, not disclosing the sad truth, the nurses described the strategies of protecting patients from upsetting information, secrecy, denying the truth and minimizing the importance of the problem. The nurses used these strategies to minimize psychological harm, avoid patient demoralization, and improve the patient’s likelihood of a fast and full recovery. Discussion: The priority for Iranian hematopoietic stem cell transplantation nurses is to first do no harm and to help patients maintain hope. This reflects the Iranian healthcare environment wherein communicating the truth to hematopoietic stem cell transplantation patients is commonly considered inappropriate and avoided. Conclusion: Iranian nurses require education and support to engage in therapeutic, culturally appropriate communication that emphasizes effective techniques for telling the truth and breaking bad news, thereby potentially improving patient outcomes and protecting patient rights. (shrink)

Fanconi anemia (FA) is generally classified as a DNA repair disorder, conferring a genetic predisposition to cancer and prominent bone marrow failure (BMF) in early childhood. Corroborative human and murine studies point to a fetal origin of hematopoietic stem cell (HSC) attrition under replicative stress. Along with intriguing recent insights into non‐canonical roles and domain‐specific functions of FA proteins, these studies have raised the possibility of a DNA repair‐independent BMF etiology. However, deeper mechanistic insight is critical as (...) current curative options of allogeneic stem cell transplantation and emerging gene therapy have limited eligibility, carry significant side effects, and involve complex procedures restricted to resource‐rich environments. To develop rational and broadly accessible therapies for FA patients, the field will need more faithful disease models that overcome the scarcity of patient samples, leverage technological advances, and adopt investigational clinical trial designs tailored for rare diseases. (shrink)

The behavior of somatic stem cells is regulated by their niche. Interaction between hematopoietic stem cells (HSCs) and their niches are a representative model to understand stem cell‐niche interplay. Here, we provide an overview of crosstalk between HSCs and their niches in bone marrow and extramedullary organs following the life journey of HSCs from emergence, development, maturation until aging. We highlight the unique differences of HSC niches in different life stages within various organs focusing on (...) recent literature to propose new speculations and hypotheses. (shrink)

Epistemology of science is currently polarized. Descriptive accounts of the social aspects of science coexist uneasily with normative accounts of scientific knowledge. This tension leads students of science to privilege one of these important aspects over the other. I use an episode of recent immunology research to develop an integrative account of scientific inquiry that resolves the tension between sociality and epistemic success. The search for the hematopoietic stem cell by members of Irving Weissman’s laboratory at Stanford (...) University Medical Center exhibits both the goal-oriented character of contemporary immunology and the importance of social interactions in successful achievement of those goals. This episode includes three kinds of epistemic success: characterization of HSC, formation of new interdisciplinary interfaces, and reconciliation of apparently incompatible models. All three depend on coordinating the work of diverse participants via social interactions. Together, they reveal the crucial role of social interactions within and between research groups in producing epistemic success. These features of the search for the HSC generalize to immunology as a whole, and plausibly to other disciplines. This account thus resolves the polarizing tension in epistemology of science, and complements individualistic accounts of scientific knowledge and rationality. (shrink)

BackgroundBeta thalassemia major is a severe inherited form of hemolytic anemia that results from ineffective erythropoiesis. Allogenic hematopoietic stem cell transplantation (HSCT) remains the only potentially curative therapy. Unfortunately, the subgroup of adult thalassemia patients with hepatomegaly, portal fibrosis and a history of irregular iron chelation have an elevated risk for transplantation-related mortality that is currently estimated to be about 29 percent.DiscussionThalassemia patients may be faced with a difficult choice: they can either continue conventional transfusion and iron (...) chelation therapy or accept the high mortality risk of HSCT in the hope of obtaining complete recovery.Throughout the decision making process, every effort should be made to sustain and enhance autonomous choice. The concept of conscious consent becomes particularly important. The patient must be made fully aware of the favourable and adverse outcomes of HSCT. Although it is the physician's duty to illustrate the possibility of completely restoring health, considerable emphasis should be put on the adverse effects of the procedure. The physician also needs to decide whether the patient is eligible for HSCT according to the "rule of descending order". The patient must be given full details on self-care and fundamental lifestyle changes and be fully aware that he/she will be partly responsible for the outcome.SummaryOnly if all the aforesaid conditions are satisfied can it be considered reasonable to propose unrelated HSCT as a potential cure for high risk thalassemia patients. (shrink)

A couple may have a child to provide stem cells for another child. They may also use preimplantation testing—even, troubling though it is, prenatal testing and selective abortion—to ensure a close tissue match.

With a view to addressing the moral concerns about the use of donor siblings, the Policy Statement of the American Academy of Pediatrics - Children as Hematopoietic Stem Cell Donors (the Policy) has laid out the criteria upon which tissue harvest from a minor would be permissible.

The informed consent process is the legal embodiment of the fundamental right of the individual to make decisions affecting his or her health., and the patient’s permission is a crucial form of respect of freedom and dignity, it becomes extremely important to enhance the patient’s understanding and recall of the information given by the physician. This statement acquires additional weight when the medical treatment proposed can potentially be detrimental or even fatal. This is the case of thalassemia patients pertaining to (...) class 3 of the Pesaro classification where Allogenic hematopoietic stem cell transplantation remains the only potentially curative treatment. Unfortunately, this kind of intervention is burdened by an elevated transplantation-related mortality risk , equal to 30% according to published reports. In thalassemia, the role of the patient in the informed consent process leading up to HSCT has not been fully investigated. This study investigated the hypothesis that information provided by physicians in the medical scenario of HSCT is not fully understood by patients and that misunderstanding and communication biases may affect the clinical decision-making process. (shrink)

BackgroundSocial support plays an important role for health outcomes. Support for those living with chronic conditions may be particularly important for their health, and even for their survival. The role of support for the survival of cancer patients after receiving an allogeneic hematopoietic cell transplant is understudied. To better understand the link between survival and support, as well as different sources and functions of support, we conducted two studies in alloHCT patients. First, we examined whether social support is (...) related to survival. Second, we examined who provides which support and which specific support-related functions and tasks are fulfilled by lay caregivers and healthcare professionals.MethodsIn Study 1, we conducted a retrospective chart review of alloHCT patients and registered availability of a dedicated lay caregiver and survival. In Study 2, we prospectively followed patients after alloHCT from the same hospital, partly overlapping from Study 1, who shared their experiences of support from lay caregivers and healthcare providers in semi-structured in-depth interviews 3 to 6 months after their first hospital discharge.ResultsPatients with a dedicated caregiver had a higher probability of surviving to 100 days than patients without a caregiver, OR = 2.84, p = 0.042. Study 2 demonstrated the importance of post-transplant support due to patients’ emotional needs and complex self-care regimen. The role of lay caregivers extended to many areas of patients’ daily lives, including support for attending doctor’s appointments, managing medications and financial tasks, physical distancing, and maintaining strict dietary requirements. Healthcare providers mainly fulfilled medical needs and provided informational support, while lay caregivers were the main source of emotional and practical support.ConclusionThe findings highlight the importance of studying support from lay caregivers as well as healthcare providers, to better understand how they work together to support patients’ adherence to recommended self-care and survival. (shrink)

Recent research highlights that inflammatory signaling pathways such as pattern recognition receptor (PRR) signaling and inflammatory cytokine signaling play an important role in both on‐demand hematopoiesis as well as steady‐state hematopoiesis. Knockout studies have demonstrated the necessity of several distinct pathways in these processes, but often lack information about the contribution of specific cell types to the phenotypes in question. Transplantation studies have increased the resolution to the level of specific cell types by testing the necessity of inflammatory (...) pathways specifically in donor hematopoietic stem and progenitor cells (HSPCs) or in recipient niche cells. Here, we argue that for an integrated understanding of how these processes occur in vivo and to inform the development of therapies that modulate hematopoietic responses, we need studies that knockout inflammatory signaling receptors in a cell‐specific manner and compare the phenotypes caused by knockout in individual niche cells versus HSPCs. (shrink)

Robust ex vivo expansion of umbilical cord blood (UCB) derived hematopoietic stem and progenitor cells (HSPCs) should enable the widespread use of UCB as a source of cells to treat hematologic and immune diseases. Novel approaches for HSPC expansion have recently been developed, setting the stage for the production of blood stem cell derived products that fulfill our current best known criteria of clinical relevance. Translating these technologies into clinical use requires bioengineering strategies to overcome challenges (...) of scale‐up, reproducibility, and product quality assurance. Clinical‐scale implementation should also define criteria and targets for cost‐effective cell manufacturing. As production strategies become more effective, new opportunities in the therapeutic use of ex vivo expanded hematopoietic cell products will emerge. Herein we examine key technological milestones that need to be met in order to move ex vivo expanded HSPC therapies from the bench‐top to the bedside in a robust and reliable manner. (shrink)

Stem cells and their malignant counterparts require the support of a specific microenvironment or “niche”. While various anti‐cancer therapies have been broadly successful, there are growing opportunities to target the environment in which these cells reside to further improve therapeutic efficacy and outcome. This is particularly true when the aim is to target normal or malignant stem cells. The field aiming to target or use the niches that harbor, protect, and support stem cells could be designated as (...) “nichotherapy”. In this essay, we provide a few examples of nichotherapies. Some have been employed for decades, such as hematopoietic stem cell mobilization, whereas others are emerging, such as chemosensitization of leukemia stem cells by targeting their niche. (shrink)

Stem cells isolated from adult mammalian tissues may provide new approaches for the autologous treatment of disease and tissue repair. Although the potential of adult stem cells has received much attention, it has also recently been brought into question. This article reviews the recent work describing the ability of non‐hematopoietic stem cells derived from adult bone marrow to form neural derivatives and their potential for brain repair. Earlier transplantation experiments imply that grafted adult stem cells (...) can differentiate into neural derivatives. Recent reports suggest, however, that such findings may be misleading and grafted cells acquiring different identities may merely be explained by their fusion with host cells and not the result of radical changes to their program of cellular differentiation. Nonetheless, in vitro studies have shown that neural development by bone‐marrow‐derived stem cells also appears possible. Understanding the molecular mechanisms that specify the neural lineage will lead to the development of tools for the targeted production of neural cell types in vitro that may ultimately provide a source of material to treat specific neurological deficits. BioEssays 24:708–713, 2002. © 2002 Wiley Periodicals, Inc. (shrink)

Stem cell science, using both embryonic and a variety of tissue-specific stem cells, is advancing rapidly and offers promise to improve medical care in the future. Yet, with the notable exception of hematopoietic stem cell transplantation, a long-established approach to treating certain cancers of the blood system, this promise is long term and most stem cell research focuses on basic scientific questions or the collection of pre-clinical data. Although some clinical trials are (...) underway, most are focused on safety, and novel effective therapy is likely a long way off. Despite the preliminary nature of most stem cell research, however, numerous clinics around the world offer stem cell “therapies” to patients today outside the context of a clinical trial. Although the number of patients who have received these stem cell-based interventions is unknown, anecdotal reports suggest a substantial population of patients is willing to try them, despite unresolved questions about their safety and efficacy. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Kennedy Institute of Ethics Journal 14.1 (2004) 47-54 [Access article in PDF] Ethical Guidelines for Human Embryonic Stem Cell Research*(A Recommended Manuscript) Adopted on 16 October 2001Revised on 20 August 2002 Ethics Committee of the Chinese National Human Genome Center at Shanghai, Shanghai 201203 Human embryonic stem cell (ES) research is a great project in the frontier of biomedical science for the twenty-first century. Be- (...) cause the research involves the use of human embryos, it triggers serious debate on ethical issues. Opponents consider the embryo to be an early form of human life that should be respected and not destroyed. However, the majority of scientists support embryonic stem cell research, believing that it offers good prospects for the treatment of diseases that have remained incurable until now and so will benefit humankind. The Ethics Committee of the Department of Ethical, Legal, and Social Implications of the Chinese National Human Genome Center at Shanghai seriously discussed the ethical debate initiated by embryonic stem cell research. We concluded that we should support the scientists of our country in actively carrying out human embryonic stem cell research for the noble cause of "medicine being a beneficent art." For the healthy and orderly development of human embryonic stem cell research in our country, we put forward the following recommended Ethical Guidelines for Human Embryonic Stem Cell Research as a reference for leaders, administrative departments, and related scientists. Preface Article 1. Human embryonic stem cells are the primitive cells that play the main role in the growth and development of a human body. These [End Page 47] primitive cells have the potential for infinite proliferation, self-renewal, and multi-directional differentiation. If scientists can discover the mechanism of differentiation of human embryonic stem cells, it will be possible to induce differentiation of human embryonic stem cells to form various types of human cells for clinical cell therapy. If human embryonic stem cell research can be integrated with modern biomedical engineering techniques, it also will be possible to make repair and replacement of human tissues and organs a reality. Article 2. There are two ways to classify human embryonic stem cells. One way is to classify them according to their potential for differentiation. There could be three kinds of stem cells: totipotent stem cells, pluripotent stem cells, and unipotent stem cells.A totipotent stem cell has the potential to develop into a whole individual. It can differentiate into the more than 200 cell types in the whole body, construct any tissue or organ of the body, and finally develop into a whole individual. The fertilized egg and the cleavage cells at the very early stage of embryonic development are totipotent stem cells.A pluripotent stem cell has the potential to differentiate into many cell types derived from the three embryonic layers. However, it has lost the capacity to develop into a complete organism.A unipotent stem cell is derived from the further differentiation of the pluripotent stem cell. It can differentiate only into one cell type such as a hematopoietic stem cell, neural stem cell, and others.The other way is to classify human stem cells according to their source. There could be two kinds of human stem cells: embryonic stem cells and tissue stem cells (also called adult stem cells). The former involves experimentation with embryos, which has serious ethical implications. Ethical issues associated with the latter are mainly expressed in the various opinions regarding the allocation of health resources. Article 3. Human embryonic stem cells are the group of cells called the blastocyst inner cell mass during the early stage of embryonic development. They are the main source of totipotent stem cells, and hence the focal and hot point in stem cell research. Studies on the clinical application of embryonic stem cells probably will involve use of the somatic cell nucleus transfer (SCNT) technique, which destroys the early human embryo. At present, the ethical and moral debate is very serious in human embryonic stem cell research regarding whether the research will develop... (shrink)

Once hematopoiesis is established in the bone marrow, a continuous egress of hematopoietic stem cells (HSCs) to the periphery occurs at a low frequency. It has been proposed that this phenomenon is part of a regenerative homeostatic mechanism that ensures the maintenance of hematopoiesis through the life of the individual. The administration of certain cytotoxic drugs or cytokines can enhance the mobilization of hematopoietic progenitors to the periphery. During the past 15 years, granulocyte‐colony stimulating factor (G‐CSF) has (...) been used as a standard cytokine for mobilization protocols in experimental models and in humans. Despite extensive efforts by multiple groups, a definitive mechanism explaining its role in mobilization has not been provided. In a recent paper, Katayama et al.,1 through a series of clever associations supported by well‐defined experimental systems, proposed that signals through the sympathetic nervous system modify the activity of the hematopoietic niche, acting as regulators of the mobilization of hematopoietic progenitors. This surprising finding adds a new level of complexity to the cellular milieu responsible for generation and maintenance of the hematopoietic niche. BioEssays 28: 687–691, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

Bone marrow is the main site for hematopoiesis in adults. It acts as a niche for hematopoietic stem cells (HSCs) and contains non‐hematopoietic cells that contribute to stem cell dormancy, quiescence, self‐renewal, and differentiation. HSC also exist in resting spleen of several species, although their contribution to hematopoiesis under steady‐state conditions is unknown. The spleen can however undergo extramedullary hematopoiesis (EMH) triggered by physiological stress or disease. With the loss of bone marrow niches in aging (...) and disease, the spleen as an alternative tissue site for hematopoiesis is an important consideration for future therapy, particularly during HSC transplantation. In terms of harnessing the spleen as a site for hematopoiesis, here the remarkable regenerative capacity of the spleen is considered with a view to forming additional or ectopic spleen tissue through cell engraftment. Studies in mice indicate the potential for such grafts to support the influx of hematopoietic cells leading to the development of normal spleen architecture. An important goal will be the formation of functional ectopic spleen tissue as an aid to hematopoietic recovery following clinical treatments that impact bone marrow. For example, expansion or replacement of niches could be considered where myeloablation ahead of HSC transplantation compromises treatment outcomes. (shrink)

Clinical success with human hematopoietic stem cell (HSC) transplantation establishes a paradigm for regenerative therapies with other types of stem cells. However, it remains generally challenging to therapeutically treat tissues after engineering of stem cells in vitro. Recent studies suggest that stem and progenitor cells sense physical features of their niches. Here, we review biophysical contributions to lineage decisions, maturation, and trafficking of blood and immune cells. Polarized cellular contractility and nuclear rheology are separately (...) shown to be functional markers of a hematopoietic hierarchy that predict the ability of a lineage to traffic in and out of the bone marrow niche. These biophysical determinants are regulated by a set of structural molecules, including cytoplasmic myosin‐II and nuclear lamins, which themselves are modulated by a diverse range of transcriptional and post‐translational mechanisms. Small molecules that target these mechanobiological circuits, along with novel bioengineering methods, could prove broadly useful in programming blood and immune cells for therapies ranging from blood transfusions to immune attack of tumors. (shrink)

Clonal disease is often regarded as almost synonymous with cancer. However, it is becoming increasingly clear that our bodies harbor numerous mutant clones that are not tumors, and mostly give rise to no disease at all. Here we discuss three somatic mutations arising within the hematopoietic system: BCR‐ABL, characteristic of chronic myeloid leukemia; mutations of the PIG‐A gene, characteristic of paroxysmal nocturnal hemoglobinuria; the V617F mutation in the JAK2 gene, characteristic of myeloproliferative diseases. The population frequencies of these three (...) blood disorders fit well with a hierarchical model of hematopoiesis. The fate of any mutant clone will depend on the target cell and on the fitness advantage, if any, that the mutation confers on the cell. In general, we can expect that only a mutation in a hematopoietic stem cell will give long‐term disease; the same mutation taking place in a cell located more downstream may produce just a ripple in the hematopoietic ocean. (shrink)

The extent to which normal (nonmalignant) cells of the body can evolve through mutation and selection during the lifetime of the organism has been a major unresolved issue in evolutionary and developmental studies. On the one hand, stable multicellular individuality seems to depend on genetic homogeneity and suppression of evolutionary conflicts at the cellular level. On the other hand, the example of clonal selection of lymphocytes indicates that certain forms of somatic mutation and selection are concordant with the organism-level fitness. (...) Recent DNA sequencing and tissue physiology studies suggest that in addition to adaptive immune cells also neurons, epithelial cells, epidermal cells, hematopoietic stem cells and functional cells in solid bodily organs are subject to evolutionary forces during the lifetime of an organism. Here we refer to these recent studies and suggest that the expanding list of somatically evolving cells modifies idealized views of biological individuals as radically different from collectives. (shrink)

T cells, which are derived from hematopoietic stem cells (HSCs), are the most important components of adaptive immune system. Based on the expression of αβ and γδ receptors, T cells are mainly divided into αβ and γδ T cells. In the thymus, they share common progenitor cells, while undergoing a series of well‐characterized and different developmental processes. N6‐Methyladenosine (m6A), one of the most abundant modifications in mRNAs, plays critical roles in cell development and maintenance of function. Recently, (...) we have demonstrated that the depletion of m6A demethylase ALKBH5 in lymphocytes specifically induces an expansion of γδ T cells through the regulation of Jag1/Notch2 signaling, but not αβ T cells, indicating a checkpoint role of ALKBH5 and m6A modification in the early development of γδ T cells. Based on previous studies, many key pathway molecules, which exert dominant roles in γδ T cell fate determination, have been identified as the targets regulated by m6A modification. In this review, we mainly summarize the potential regulation between m6A modification and these key signaling molecules in the γδ T cell lineage commitment, to provide new perspectives in the checkpoint of γδ T cell development. (shrink)

Two enzymes involved in the synthesis of pyrimidine and purine nucleotides, CTP synthase (CTPS) and IMP dehydrogenase (IMPDH), can assemble into a single or very few large filaments called rods and rings (RR) or cytoophidia. Most recently, asymmetric cytoplasmic distribution of organelles during cell division has been described as a decisive event in hematopoietic stem cell fate. We propose that cytoophidia, which could be considered as membrane‐less organelles, may also be distributed asymmetrically during mammalian cell (...) division as previously described for Schizosaccharomyces pombe. Furthermore, because each type of nucleotide intervenes in distinct processes (e.g., membrane synthesis, glycosylation, and G protein‐signaling), alterations in the rate of synthesis of specific nucleotide types could influence cell differentiation in multiple ways. Therefore, we hypothesize that whether a daughter cell inherits or not CTPS or IMPDH filaments determines its fate and that this asymmetric inheritance, together with the dynamic nature of these structures enables plasticity in a cell population. (shrink)

Advance care planning (ACP) is a process that seeks to elicit patients’ goals, values, and preferences for future medical care. While most commonly employed in adult patients, pediatric ACP is becoming a standard of practice for adolescent and young adult patients with potentially life-limiting illnesses. The majority of research has focused on patients and their families; little attention has been paid to the perspectives of healthcare providers (HCPs) regarding their perspectives on the process and its potential benefits and limitations. Focus (...) groups were conducted with 15 physicians as part of a larger study of adolescent and young adult ACP in hematopoietic stem cell transplant (HSCT) patients. This study identified two categories important to the utility of ACP in pediatric HSCT patients; (1) the temporal context of ACP and decision making and (2) the limitations of pediatric ACP, with subcategories identified as (a) embodied and witnessed knowing, (b) the impact of clinical cascades—when the treatment of one organ system creates complications in another system that needs to be treated—and a creation of a “new normal” following complications of illness and its treatment in the pediatric intensive care unit (PICU), (c) the balancing of adolescents’ autonomy with their capacity to make informed medical decisions, and (d) the epistemological frames that differ between HCP and patients and their families. These findings support ACP in adolescent and young adult HSCT patients, with a number of implications for practice as this process becomes more common. (shrink)

One of the more controversial uses of preimplantation genetic diagnosis (PGD) involves selecting embryos with a specific tissue type so that the child to be born can act as a donor to an existing sibling who requires a haematopoietic stem cell transplant. PGD with HLA tissue typing is used to select embryos that are free of a familial genetic disease and that are also a tissue match for an existing sibling who requires a transplant. Preimplantation HLA tissue typing (...) occurs when parents select embryos that are not at risk of a familial genetic disease to be a match for an existing sibling who requires a transplant. In Victoria, Australia, applications to use PGD with HLA tissue typing are reviewed by the Infertility Treatment Authority on a case by case basis. Preimplantation HLA tissue typing is prohibited prima facie because the embryo to be tested would not be at risk for a genetic abnormality or disease. Arguments for or against the use of PGD/HLA tissue typing are based on several key issues including the commodification and welfare of the donor child. This essay aims to show that that the same arguments apply to both PGD with HLA tissue typing and Preimplantation HLA tissue typing, and that the policy distinction between the two procedures is therefore ethically inconsistent. (shrink)

Preimplantation genetic diagnosis is a technique which was originally developed as an alternative to prenatal diagnosis for couples at high risk of transmitting a genetic defect. It allows scientists to check specific genetic defects of the embryo obtained through in vitro fertilization so that only embryos not affected by the tested disease or balanced for the tested chromosomes can be replaced. Recently, case reports reveal that clinicians applying PGD are increasingly confronted with requests by parents with an affected child whishing (...) for PGD not only to test IVF-created embryos for genetic disease but also to test for a nondisease trial related to immune compatibility with a child in the family in need of a hematopoietic stem cell transplant. Only embryos HLA matched with an existing sibling in need of a compatible donor of haematopoietic stem cells would be transferred. In this article, our main objective is not to answer the question of the ethical permissibility of this technique. We rather want to clarify some anthropological options underpinning this technique, which have to be taken into account for an ethical evaluation. By virtue of its very being, the human person is multidimensional: open to itself, to another and to society. This multidimensional character of the human person is a real challenge in the field of human genetics and medically assisted reproduction: a couple never decides solely for itself, but its decision has an enormous impact on their offspring; the physician is a necessary third person in the decision making process; a parental decision is influenced by and ma y change the public support of PGD. First we have to evaluate the request of the couple to use PGD in order to create a donor sibling. The main ethical argument against this kind of request is the instrumentalization of the future child. The child becomes an instrument to cure another child. One of the fundamental rules underlying Western moral thinking is the Kantian imperative. The second formulation of the categorical imperative goes as follows: ‘Act in such a way that you always treat humanity, whether in your own person or the person of any other, never simply as a means, but always at the same time as an end’. From this perspective we advance the ethical requirement to surpass the apparent discrepancy between the need of the parents to produce a healthy child and the desire of parents to have a child. Second, the physician should take into account the fact that a technological innovation may have such a compelling character that human reproductive freedom will be restricted rather than enlarged. Thus the physician should be guarded from engaging in so-called medical futile acts. Third, the experience of the donor child will be discussed. It could be argued that a heavy burden is placed on the donor child. The transplantation may fail and this may give the child a fundamental sense of unworthiness and deficiency and a feeling of not being able to live up to the expectations. The psychological impact of stem cell donation among siblings should indeed not be underestimated. Finally, on societal level, the need for instant success has contributed to ever more invasive reproductive technologies. We question however that reproductive success does not necessarily depends on the invasiveness of the techniques. Parents should be given time to put meaning on their lack of reproductive omnipotence. (shrink)

BackgroundThe Act Regarding the Promotion of the Appropriate Supply of Hematopoietic Stem Cells for Transplant regulates only how public banks store and provide umbilical cord blood for research or transplantation. Japan had no laws to regulate how the private banks manage the procedures, harvesting, preparation, and storage of such blood. As a result, the status of UCB distribution remains unknown. We conducted a survey to investigate the current status of UCB storage and provision to private biobanks by Japanese (...) institutions that handle childbirth.MethodsQuestionnaire forms were mailed to 3,277 facilities handling childbirth that were registered in the Japan Council for Quality Health Care website.ResultsOf the 1,192 institutions handling childbirth that participated in the survey, 34.4% responded that they currently provide UCB to private biobanks, while 16.1% of facilities did so in the past. Moreover, some institutions currently provide or formerly provided UCB to medical treatment facilities, research institutions, companies, or overseas treatment facilities, research institutions, or companies. A certain number of institutions handling childbirth did not even provide explanations or obtain consent when the UCB was harvested from private bank users.ConclusionsThis is the first study to determine the status of UCB provision to private banks by Japanese institutions handling childbirth. Future studies will need to examine in detail how institutions handling childbirth provide explanations to private bank users and UCB providers as well as how these institutions obtain consent. (shrink)

Hematopoiesis is the complex developmental process through which undifferentiated, pluripotent, hematopoietic stem cells come to generate mature, functional blood cells. This process is regulated in large part by specific transcription factors that control expression of genes necessary for the developmental sequence. Leukemias represent one form of disruption of this normal developmental process, and studies over the past few years have shown that many of the genes that underlay leukemogenesis are also essential for normal hematopoiesis. In an interesting recent (...) example, Song et al.(1) demonstrate that haploinsufficiency of the AML1 gene is the genetic basis of a form of familial thrombocytopenia which predisposes the affected individuals to the development of acute myeloid leukemia. Here we summarize Song's paper and current information describing the interesting dosage effects of this gene and other members of its gene family. BioEssays 22:214–218, 2000. © 2000 John Wiley & Sons, Inc. (shrink)

Ascorbic acid is a redox regulator in many physiological processes. Besides its antioxidant activity, many intriguing functions of ascorbic acid in the expression of immunoregulatory genes have been suggested. Ascorbic acid acts as a co‐factor for the Fe+2‐containing α‐ketoglutarate‐dependent Jumonji‐C domain‐containing histone demethylases (JHDM) and Ten eleven translocation (TET) methylcytosine dioxygenasemediated epigenetic modulation. By influencing JHDM and TET, ascorbic acid facilitates the differentiation of double negative (CD4−CD8−) T cells to double positive (CD4+CD8+) T cells and of T‐helper cells to different (...) effector subsets. Ascorbic acid modulates plasma cell differentiation and promotes early differentiation of hematopoietic stem cells (HSCs) to NK cells. These findings indicate that ascorbic acid plays a significant role in regulating both innate and adaptive immune cells, opening up new research areas in Immunonutrition. Being a water‐soluble vitamin and a safe micro‐nutrient, ascorbic acid can be used as an adjunct therapy for many disorders of the immune system. (shrink)

The case presents a teenage girl, Sam*, in the end stages of a rare disease, with no proven therapeutic options and an investigational hematopoietic stem cell transplant has been offered thr...

The hematopoietic system consists of more than ten differentiated cell types, all of which are derived from a single type of hematopoietic stem cell. The accessibility and interest of this system have made it a model for understanding normal and abnormal differentiation of mammalian cells. Newer techniques have generated a mass of data that requires integrative approaches for analysis and interpretation. The traditional view of the differentiation program holds that a small number of regulators are (...) involved in each stage of cell specification. However, this may not be the case. Recent analyses have shown that almost all substantial subsets of genes, including the set of broadly expressed transcription factors, are expressed in patterns that are unique for each lineage. Further, much of this difference between lineages can be captured in two‐dimensional graphs. Understanding the biologic significance, mechanisms and constraints underlying these differences is a challenge for experimentalists and computational biologists alike. BioEssays 26:1276–1287, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

This book explores the ethical and governance concerns of stem cell technology, taking a comparative approach between countries of differing socio-economic status. The book provides a typology of different stem cell types and discusses key ethical issues surrounding the use of human stem cells in research. Topics covered include the moral status of human embryos, various religious perspectives, and the challenges posed by unproven stem cell interventions. The book also examines the existing governance (...) frameworks in the UK, Singapore, and Malaysia, identifying the laws, guidelines, and advisory bodies established to address the identified ethical issues. Applicable lessons on establishing robust regulatory frameworks, fostering public trust, and ensuring responsible research practices are outlined. By providing a comparative analysis of the interplay between ethics, governance, and the socio-economic contexts of these three commonwealth countries, this book will interest health law, research ethics and bioethics scholars. (shrink)

If stem cell-based therapies are developed, we will likely confront a difficult problem of justice: for biological reasons alone, the new therapies might benefit only a limited range of patients. In fact, they might benefit primarily white Americans, thereby exacerbating long-standing differences in health and health care.

While the clinical promise of much stem cell research remains largely theoretical, patients are nonetheless pursuing unproven stem cell therapies in jurisdictions around the world—a phenomenon referred to as “stem cell tourism.” These treatments are generally advertised on a direct-to-consumer basis via the Internet. Research shows portrayals of stem cell medicine on such websites are overly optimistic and the claims made are unsubstantiated by published evidence. However, anecdotal evidence suggests that parents are (...) pursing these “treatments” for their children, despite potential physical and financial risk. Physicians are in a unique position as they can be expected to be involved in, or privy to, such decisions. In this paper, we consider what duties physicians may have toward minor patients whose parents/guardians wish to engage in stem cell tourism on their behalf. We use the Canadian perspective to address the broadly relevant issues raised by this trend. (shrink)

Self‐renewal and differentiation of stem cells are tightly regulated processes subject to intrinsic and extrinsic signals. Molecular chaperones and co‐chaperones, especially heat shock proteins (Hsp), are ubiquitous molecules involved in the modulation of protein conformational and complexation states. The function of Hsp, which are typically associated with stress response and tolerance, is well characterized in differentiated cells, while their role in stem cells remains unclear. It appears that embryonic stem cells exhibit increased stress tolerance and concomitant high (...) levels of chaperone expression. This review critically evaluates stem cell research from a molecular chaperone perspective. Furthermore, we propose a model of chaperone‐modulated self‐renewal in mouse embryonic stem cells. (shrink)

The paper looks in detail at patients that were treated at one of the most discussed companies operating in the field of untried stem cell treatments, Beike Biotech of Shenzhen, China. Our data show that patients who had been treated at Beike Biotech view themselves as proactively pursuing treatment choices that are not available in their home countries. These patients typically come from a broad variety of countries: China, the United Kingdom, the United States, South Africa and Australia. (...) Among the patients we interviewed there seemed to be both an awareness of the general risks involved in such experimental treatments and a readiness to accept those risks weighed against the possible benefits. We interpret this evidence as possibly reflecting the emergence of risk-taking patients as ‘consumers’ of medical options as well as the drive of patients to seek treatment options in the global arena, rather than being hindered by the ethical and regulatory constraints of their home countries. Further, we found that these patients tend to operate in more or less stable networks and groups in which they interact and cooperate closely and develop opinions and assessments of available treatment options for their ailments. These patients also perform a multiple role as patients, research subjects, and research funders because they are required to pay their way into treatment and research activities. This new social dynamics of patienthood has important implications for the ethical governance of stem cell treatments. (shrink)

Adult stem cell populations must coordinate their own maintenance with the generation of differentiated cell types to sustain organ physiology, in a spatially controlled manner and over long periods. Quantitative analyses of clonal dynamics have revealed that, in epithelia, homeostasis is achieved at the population rather than at the single stem cell level, suggesting that feedback mechanisms coordinate stem cell maintenance and progeny generation. In the central nervous system, however, little is known of (...) the possible community processes underlying neural stem cell maintenance. Recent work, in part based on intravital imaging made possible in the adult zebrafish, conclusively highlights that homeostasis in neural stem cell pools may rely on population asymmetry and long‐term spatiotemporal coordination of neural stem cell states and fates. These results suggest that neural stem cell assemblies in the vertebrate brain behave as self‐organized systems, such that the stem cells themselves generate their own intrinsic niche. (shrink)

This paper examines a case of failed interdisciplinary collaboration, between experimental stem cell research and theoretical systems biology. Recently, two groups of theoretical biologists have proposed dynamical systems models as a basis for understanding stem cells and their distinctive capacities. Experimental stem cell biologists, whose work focuses on manipulation of concrete cells, tissues and organisms, have largely ignored these proposals. I argue that ‘failure to communicate’ in this case is rooted in divergent views of explanation: (...) the theoretically-inclined modelers are committed to a version of the covering-law view, while experimental stem cell biologists aim at mechanistic explanations. I propose a way to reconcile these two explanatory approaches to cell development, and discuss the significance of this result for interdisciplinary collaboration in systems biology and beyond. (shrink)

We review recent progress in the stem cell biology of the respiratory system, and discuss its scientific and translational ramifications. Several studies have defined novel stem cells in postnatal lung and airways and implicated their roles in tissue homeostasis and repair. In addition, significant advances in the generation of respiratory epithelium from pluripotent stem cells (PSCs) now provide a novel and powerful platform for understanding lung development, modeling pulmonary diseases, and implementing drug screening. Finally, breakthroughs have (...) been made in the generation of decellularized lung matrices that can serve as a scaffold for repopulation with respiratory cells derived from either postnatal or PSCs. These studies are a critical step forward towards the still distant goal of stem cell‐based regenerative medicine for diseases of lung and airways. (shrink)

Pike, Gregory K The various levels at which misunderstanding exist with regards to stem cell research are discussed. The mismatch that exists between public perception and reality with regards to the same is highlighted.

Cascades of transcriptional regulation are the common source of the forward drive in all developmental systems. Increases in complexity and specificity of gene expression at successive stages are based on the collaboration of varied combinations of transcription factors already expressed in the cells to turn on new genes, and the logical relationships between the transcription factors acting and becoming newly expressed from stage to stage are best visualized as gene regulatory networks. However, gene regulatory networks used in different developmental contexts (...) underlie processes that actually operate through different sets of rules, which affect the kinetics, synchronicity, and logical properties of individual network nodes. Contrasting early embryonic development in flies and sea urchins with adult mammalian hematopoietic development from stem cells, major differences are seen in transcription factor dosage dependence, the silencing or damping impacts of repression, and the impact of cellular regulatory history on the parts of the genome that are accessible to transcription factor action in a given cell type. These different features not only affect the kinds of models that can illuminate developmental mechanisms in the respective biological systems, but also reflect the evolutionary needs of these biological systems to optimize different aspects of development. (shrink)

Various cell types cooperate to create a highly organized and dynamic micro-environmental niche in the bone marrow. Over the past several years, the field has increasingly recognized the critical roles of the interplay between bone marrow environment and hematopoietic cells in normal and deranged hematopoiesis. These advances rely on several new technologies that have allowed us to characterize the identity and roles of these niches in great detail. Here, we review the progress of the last several years, list (...) some of the outstanding questions in the field and propose ways to target the diseased environment to better treat hematologic diseases. Understanding the extrinsic regulation by the niche will help boost hematopoiesis for regenerative medicine. Based on natural development of hematologic malignancies, we propose that combinatory targeting the niche and hematopoietic intrinsic mechanisms in early stages of hematopoietic malignancies may help eliminate minimal residual disease and have the highest efficacy. The bone marrow is the home for blood-forming hematopoietic stem and progenitor cells. Normal generation of blood and immune cells depends on highly regulated interactions between these stem and progenitor cells with their surrounding environment. Emerging evidence suggests that therapeutic interventions directed at these cellular interdependencies can help boost hematopoiesis and eradicate malignant hematopoietic cells. (shrink)

The possibility of obtaining stem cells from human embryos has given rise to an intensive legal and ethical debate. In this paper, attention is paid to the normative disparity and ambiguity in Europe. An argument for the need for a minimal legal harmonization is made; and a prudent and flexible way to reach this successfully is suggested. Establishing a common legal framework seems to be the only way to guarantee true competitiveness for the European scientific community.

This paper queries why we are more reluctant to perform stem cell research on human than on nonhuman embryos, given their remarkable similarities together with the former's greater promise for addressing human illnesses. I begin by examining two leading arguments for prohibiting stem cell research on human embryos. The first type of argument suggests that we should not interfere with the potential for human life. This argument, advanced in different ways by both utilitarians and religious believers, (...) inadequately grapples with the moral complexities raised by current technologies, such as IVF and cloning. Moreover, it fails to address the significant adverse effects of human overpopulation to both human and nonhuman well-being. The second line of argument addressed here suggests that we are morally prohibited from "playing God." This argument overlooks the various ways in which we do—indeed, we must—make life and death decisions. Further, the argument rests on an undefended assumption that we are only prohibited from making such decisions with regard to human life, while remaining free to make such decisions with regard to animals without apparent moral qualms. On the contrary, I argue that, from a fully ethical Darwinian standpoint, we must treat both human and nonhuman life with respect. Far from requiring us to abstain from difficult moral decision making, an attitude of respect toward all life requires human willingness to take responsibility for making difficult—indeed, sometimes excruciating—moral decisions. (shrink)

Robert Sparrow has recently raised the possibility that stem cell technology could in the future be used to create multiple generations of embryos in the laboratory before transferring one embryo to a woman’s womb to create a pregnancy. Sparrow argues that any children produced in this way would be genetic orphans—they would lack living genetic parents—and explores the possible moral implications of this. A number of other authors have raised objections to Sparrow’s moral claims, but his descriptive claim (...) remains unchallenged. In this chapter, we challenge it, arguing that Sparrow’s imagined technology could be performed in such a way that the children produced would have living genetic parents. (shrink)