Approaching Religious Guidelines for Chimera Policymaking

Recent developments in the use of cow egg cells to clone human somatic cells, and the grafting by researchers at several universities of human neurons into mice, bring the notion of the chimera, a mixture of several living organisms, from myth into reality. In his article “Cross‐Species Chimeras: Exploring a Possible Christian Perspective,” Neville Cobbe considers the religious arguments overlying the creation of human‐nonhuman chimeras. In my commentary I focus on the distinction between germline‐ and tissue transplant‐related chimeric techniques implicit in Cobbe's essay and argue that the former poses more serious moral difficulties than the latter if the chimeric product is brought to term. The substantive view of the imago Dei, or image of God, serves as a scaffold by which to judge the permissibility of chimera creation using stem cell and other tissue implants. While useful for judging the rights of such artificially generated beings, I argue that specific criteria such as proportion of tissue uptake, mental capacity, and adherence with the organism's telos are more appropriately considered within a composite image of the living being reflecting its unique integrality. Human co‐creativity with the Divine will inevitably prompt attempts to generate medically useful chimeras. Religious dialogue, combined with the categories of religious moral argument appearing in Cobbe's essay, will help to establish the outline of feasible policy guidelines addressing the complexities inherent in the creation of chimeras.     

Enhanced proliferation of progenitor cells following long-term potentiation induction in the rat dentate gyrus

The dentate gyrus (DG) is among the few areas in the mammalian brain where production of new neurons continues in the adulthood. Although its functional significance is not completely understood, several lines of evidence suggest the role of DG neurogenesis in learning and memory. Considering that long-term potentiation (LTP) is a prime candidate for the process underlying hippocampal learning and memory, these results raise the possibility that LTP and neurogenesis are closely related. Here, we investigated whether or not LTP induction in the afferent pathway triggers enhanced proliferation of progenitor cells in the DG. LTP was induced by tetanic stimulation in perforant path-DG synapses in one hemisphere, and the number of newly generated progenitor (BrdU-labeled) cells in the DG was quantified. Compared with the control hemisphere (stimulated with low-frequency pulses), the LTP-induced hemisphere contained a significantly higher number of newly generated progenitor cells in the dorsal as well as ventral DG. When CPP, an NMDA receptor antagonist, was administered, tetanic stimulation neither induced LTP nor enhanced progenitor cell proliferation, indicating that NMDA receptor activation, rather than tetanic stimulation per se, is responsible for enhanced progenitor proliferation in the control animal. Our results show that tetanic stimulation of perforant path sufficient to induce LTP increases progenitor proliferation in adult DG in an NMDA receptor-dependent manner.     

GOLEMS IN THE BIOTECH CENTURY

The legend of the golem, the creation of life through mystical and magical means, is the most famous postbiblical Jewish legend. After noting recent references to the golem legend in fiction, film, art, and scientific literature, I outline three stages of the development of the legend, including its relationship to the story of Frankenstein. I apply teachings about the golem in classical Jewish religious literature to implications of the legend for ethical issues relating to bioengineering, reproductive biotechnology, robotics, artificial intelligence, artificial life, and corporate ethics. The golem legend emerges as a source of prudent guidance through the minefield of ethical and spiritual problems emerging from current and expected developments in biotechnology.     

Confronting Deep Moral Disagreement: The President's Council on Bioethics,Moral Status,and Human Embryos

The report of the President's Council on Bioethics, Human Cloning and Human Dignity, addresses the central ethical, political, and policy issue in human embryonic stem cell research: the moral status of extracorporeal human embryos. The Council members were in sharp disagreement on this issue and essentially failed to adequately engage and respectfully acknowledge each others' deepest moral concerns, despite their stated commitment to do so. This essay provides a detailed critique of the two extreme views on the Council (i.e., embryos have full moral status or they have none at all) and then gives theoretical grounding for our judgment about the intermediate moral status of embryos. It also supplies an account of how to address profound moral disagreements in the public arena, especially by way of constructing a middle ground that deliberately pays sincere respect to the views of those with whom it has deep disagreements.     

Community-based Research and Technoscience Activism: A Report on the Living Knowledge 3 Conference

New medical imaging technologies enable the production of photos of human cells that are magnified to make them visible to the eye. Such cellular images have gained aesthetic as well as dramatic appeal, as they have moved out of the laboratories and become available for the public. At this stage, they are refashioned to reveal matters more clearly and pedagogically. Organic matter that might be confusing to the audience is removed and colours added to distinguish various aspects—but despite such manipulations, the result appears as images of real human cells, making them different from drawings and models. One example of this is the website of a Norwegian governmental organization for information on biotechnology and bioethics which displays images of egg and sperm cells related to techniques of assisted reproduction. These images represent cells as autonomous and independent of human gendered bodies. The process whereby cells culturally become detached and disassociated from human bodies is here referred to as a process of entification whereby the cells reappear as detachable, usable entities.     

肿瘤干细胞研究的进展及启示

肿瘤干细胞理论认为,肿瘤增长是由肿瘤中具有干细胞特性的细胞分裂增殖引起的。针对性地抑制肿瘤干细胞的增殖,能显著提高肿瘤治愈率。本文用哲学的观点对肿瘤干细胞假说的提出、验证、临床应用进行分析,对于深入认识肿瘤干细胞的本质、探索其分离方法、发现抑制其增殖的有效手段将起到积极作用。     

长柄假体置换治疗高龄粉碎性粗隆间骨折的随访研究

为了探讨长柄假体置换治疗高龄粉碎性粗隆间骨折的短期疗效,我们对31例符合要求的研究对象进行了平均22个月的随访,指标包括Charnley及Harris评分以及X-ray平片,结果最近一次X—ray观察3例出现异位骨化,无一例假体松动,Charnley分级Ⅳ级及以上90．0％,Harris评分优良率88．3％,因此长柄假体置换是治疗高龄粉碎性粗隆间骨折的理想选择之一。     

“三腿一平台”组成的“基因打靶”——评介2007年度诺贝尔医学奖

2007年度诺贝尔医学奖项目——基因打靶,由三腿和一个平台所构成。三条腿分别是转基因学、同源重组和胚胎干细胞,一个平台指的是基因敲除。除了评价这些组成部分以外,还对推迟评奖进行了质疑。     

中枢肥大细胞在脑功能和行为调节中的作用

已知肥大细胞作为免疫细胞在过敏反应和炎性疾病中发挥重要作用。肥大细胞在中枢亦有表达, 但对其作用了解不足。新近的研究发现中枢肥大细胞在脑功能和行为调节中发挥重要的内源性平衡作用。一方面, 中枢肥大细胞在维持相关脑区发育, 正常神经活动, 以及动机, 情绪和认知等多种行为中发挥保护性作用, 各种应激条件诱导的中枢肥大细胞表达和活动改变参与脑和行为的适应性反应过程。另一方面, 中枢肥大细胞过度激活或者过度抑制都可导致脑功能和行为异常, 并参与某些免疫相关心身疾病的病理过程。体外神经解剖学和功能学研究证据提示中枢肥大细胞与神经系统间存在结构性和功能性相互作用网络。肥大细胞和神经组织间通过形成类似突触的结构性联系直接影响相邻细胞的活动。肥大细胞还可以通过脱颗粒释放多种生物活性介质调节神经活动, 同时表达多种受体接受脑内免疫性和神经性分子调节。但是目前对于中枢肥大细胞-神经系统相互作用的认识主要基于体外研究, 其在脑内相互作用方式及其与特定脑区功能和行为表型的关系所知甚少, 开展相关研究可以为认识脑与行为的神经免疫调节机制提供新的视角。