Ethical Issues in Limb Transplants

On one view, limb transplants cross technological frontiers but not ethical ones; the only issues to be resolved concern professional competence, under the assumption of patient autonomy. Given that the benefits of limb transplant do not outweigh the risks, however, the autonomy and rationality of the patient are not necessarily self-evident. In addition to questions of resource allocation and informed consent, limb, and particularly hand, allograft also raises important issues of personal identity and bodily integrity. We present two linked schemas for exploring ethical issues in limb transplants. The first, relying on conventional concepts in biomedical ethics, asks whether the procedure is research or therapy, whether the costs outweigh the benefits, and whether it should be up to the patient to decide. The second introduces more speculative and theoretically challenging questions, including bodily integrity, the argument from unnaturalness, and the function of the hand in expressing personal identity and intimacy. We conclude that limb transplants are not ruled out a priori , unlike some procedures that are prima facie wrong to perform, such as amputation of healthy limbs to relieve body dysmorphic disorders. However, their legitimacy is not proven by appeals to the interests of scientific research, cost-benefit, or patient autonomy.     

Facial Transplants in Xenopus laevis Embryos

Craniofacial birth defects occur in 1 out of every 700 live births, but etiology is rarely known due to limited understanding of craniofacial development. To identify where signaling pathways and tissues act during patterning of the developing face, a ''face transplant'' technique has been developed in embryos of the frog Xenopus laevis. A region of presumptive facial tissue (the "Extreme Anterior Domain" (EAD)) is removed from a donor embryo at tailbud stage, and transplanted to a host embryo of the same stage, from which the equivalent region has been removed. This can be used to generate a chimeric face where the host or donor tissue has a loss or gain of function in a gene, and/or includes a lineage label. After healing, the outcome of development is monitored, and indicates roles of the signaling pathway within the donor or surrounding host tissues. Xenopus is a valuable model for face development, as the facial region is large and readily accessible for micromanipulation. Many embryos can be assayed, over a short time period since development occurs rapidly. Findings in the frog are relevant to human development, since craniofacial processes appear conserved between Xenopus and mammals.     

From Legal Transplants to Sustainable Transition

Extended producer responsibility (EPR), which assigns significant responsibility to producers to take back their end‐of‐life products to create incentives for redesign of products with lower life cycle environmental impacts, has come to a crossroad facing a trade‐off between the original innovation‐oriented regime design and the cost‐efficiency challenges in practice. This is particularly true in its implementation in non‐Organization for Economic Co‐operation and Development (OECD) countries as they are trying to transplant the “best practices” from OECD countries, for there is increasing skepticism as to whether EPR is suitable for developing countries at all. As an important producer of electronic products and destination of electronic waste (e‐waste) flows in the world, China has been expected to play a vital role in the evolution of global governance based on the idea of EPR, either to create new ways for producers to perform their end‐of‐life strategies, or to reshape the mode of production and consumption with its fast‐growing market. However, the establishment of EPR in China has been long and full of difficulties. This article reviews the status and trends in the establishment of an EPR system for waste electrical and electronic equipment (WEEE) management in China. We use the framework of a multilevel perspective of transition theory in our analysis to characterize the complex interactions among various agents in the evolution of the Chinese system from initial innovation‐oriented design to the current efficiency‐oriented version. An ongoing research framework for evaluation of the EPR program in China is outlined as the research agenda in coming years.     

防止肌腱粘连及促进其愈合的研究进展

随着对肌腱愈合研究的不断深入和发展,预防肌腱粘连以及促进其愈合的方法越来越多。通过改进缝合方法、修复腱鞘或采用替代品、置入药物或药物薄膜及早期康复等治疗来有效预防肌腱粘连;通过重建腱鞘、药物、生长因子、基因干预等促进肌腱愈合。本文就近年来防止肌腱粘连及促进其愈合方面的研究予以综述。     

NADPH-Diaphorase-Positive Nerve Cells in Heterotopic Spinal Cord Transplants

The method of ectopic transplantation of embryonic CNS rudiments makes it possible to study the mechanisms underlying adaptation of the transplanted embryonic rudiments. The production of nitric oxide by cells is considered as one of such mechanisms. NADPH-diaphorase is an index of the presence of nitric oxide synthase in cells. It was shown that the nerve cells of rat embryonic spinal cord transplants preserved their capacity to express NADPH-diaphorase after transplantation in the sciatic nerve of an adult animal for six months. The dynamics of NADPH-diaphorase-positive neurons of rat embryonic spinal cord developing after transplantation and in situwere studied. In spinal cord neck region, small bipolar NADPH-diaphorase-positive neurons were visualized on day 17 of prenatal development. After transplantation of the embryonic (day 15) spinal cord in the nerve, NADPH-diaphorase-positive neurons were formed later than in situ: within seven days. The results of histochemical studies carried out within six months after the operation suggest a protective role of NADPH-diaphorase in the neurons of allotransplants developing under the conditions of altered microenvironment and insufficient innervation and also suggest that nitric oxide can cause the death of neurons in long surviving transplants.     

Biological Healing of Large Diaphyseal Deep-frozen Allograft Transplants

The biological healing of large, deep-frozen, diaphyseal allografts was studied in 24 cats. Deep-frozen allograft stored at –80°C was used to replace a large defect, at least two-thirds of the cat's tibial diaphysis. Intra-medullary rod fixation was used. The healing was studied at observation periods of 4, 6, 8, 12, 16, 24 and 36 weeks. Biological parameters studied included microangiography for revascularisation and fracture healing, bone resorption, new bone formation and callus encasement. Deep-frozen allografts united without difficulty by 12 weeks. However, minimal revascularisation of the allograft occurred even at 9 months. Likewise, minimal biological repair activity was seen even at 9 months as shown by the parameters of bone resorption, cortical new bone formation and callus encasement. Biologically, deep-frozen cortical allografts remained inert for a long period of time in the adult cat.