关于阴茎移植的伦理问题

随着医学科学的发展,器官移植日趋成熟,不仅使患者延长了生命,更大大提高了生活质量.阴茎移植是器官移植和免疫学发展的结晶,是异体器官移植领域内新的突破,为阴茎缺失的患者带来了新生,对患者心理、家庭和社会有着重大影响.但目前异体阴茎移植刚刚起步,技术尚不成熟,且阴茎是一特殊器官,涉及到的伦理道德问题很多,我们试图从受者、供者、医生和法律等方面讨论阴茎移植所面临的伦理道德问题,希望阴茎移植能真正造福于人类.     

关于阴茎移植的伦理问题

随着医学科学的发展,器官移植日趋成熟,不仅使患者延长了生命,更大大提高了生活质量。阴茎移植是器官移植和免疫学发展的结晶,是异体器官移植领域内新的突破,为阴茎缺失的患者带来了新生,对患者心理、家庭和社会有着重大影响。但目前异体阴茎移植刚刚起步,技术尚不成熟,且阴茎是一特殊器官,涉及到的伦理道德问题很多,我们试图从受者、供者、医生和法律等方面讨论阴茎移植所面临的伦理道德问题,希望阴茎移植能真正造福于人类。     

诱导多能干细胞技术的生命伦理分析

诱导多能干细胞(induced pluripotent stem cells,iPSCs)是通过向分化的体细胞转入特定的外源转录因子进行重编程,从而获得具有自我更新能力和多能性的细胞.iPSCs具有形成体内所有细胞类型的潜能,尤其是能以患者自身体细胞制备iPSCs,可用于特定疾病的治疗,规避了异体移植引发的免疫排斥风险以及伦理和法律冲突等问题,在基础研究和临床应用都有广阔的应用前景.目前,在重编程体细胞为iPSCs的过程中,由于细胞来源不同,所采用的基因组合以及转基因方式各不相同,获得的iPSCs具有潜在的致癌性等安全隐患,导致iPSCs的临床应用面临新的生命伦理挑战.     

31例眼睑恶性肿瘤切除后Ⅰ期修复的总结

眼睑恶性肿瘤切除术后,眼睑修复时机的选择,对保持眼睑功能和美容的效果起着十分重要的作用,术式的选择是决定手术成功关键.采用眼睑全层缺损行异体巩膜片移植,替代睑板、滑行球结膜瓣前徙替代睑结膜的眼睑再造术,对31例眼睑恶性肿瘤切除,同时进行眼睑再造术.术后无排斥反应,眼睑闭合良好,外形满意.结论认为,较大范围的眼睑恶性肿瘤切除的患者,采用异体巩膜片移植、滑行结膜瓣前徙眼睑再造术能达到保持眼睑功能和美容的效果,是理想的眼睑恶性肿瘤切除后Ⅰ期修复临床决策.     

从受体角度审视同种异体脸面移植的伦理问题

异体脸面移植已经成为治疗面部损伤的一种新兴的、有效的方式,对于提高面部损伤患者的生命尊严与质量具有重要意义,脸面移植的伦理辩论也应随着移植技术的进步不断更新。本文从受体角度分析了异体脸面移植存在的四个核心伦理问题,即移植资源的公平分配、成本效益比不确定、知情同意权的深入贯彻以及医疗赞助诱发的问题,提出了完善移植纳入排除标准,明确移植先后顺序、降低手术风险,提高手术安全性、保证足够考虑时间,进行知情同意评估、建立立体的费用支持体系,积极面对媒体的对策建议,旨在从伦理道德角度保障异体脸面移植患者的合理权益。     

诱导多能干细胞技术的生命伦理分析

诱导多能干细胞(induced pluripotent stem cells,iPSCs)是通过向分化的体细胞转入特定的外源转录因子进行重编程,从而获得具有自我更新能力和多能性的细胞。iPSCs具有形成体内所有细胞类型的潜能,尤其是能以患者自身体细胞制备iPSCs,可用于特定疾病的治疗,规避了异体移植引发的免疫排斥风险以及伦理和法律冲突等问题,在基础研究和临床应用都有广阔的应用前景。目前,在重编程体细胞为iPSCs的过程中,由于细胞来源不同,所采用的基因组合以及转基因方式各不相同,获得的iPSCs具有潜在的致癌性等安全隐患,导致iPSCs的临床应用面临新的生命伦理挑战。     

31例眼睑恶性肿瘤切除后Ⅰ期修复的总结

眼睑恶性肿瘤切除术后,眼睑修复时机的选择,对保持眼睑功能和美容的效果起着十分重要的作用,术式的选择是决定手术成功关键。采用眼睑全层缺损行异体巩膜片移植,替代睑板、滑行球结膜瓣前徙替代睑结膜的眼睑再造术,对31例眼睑恶性肿瘤切除,同时进行眼睑再造术。术后无排斥反应,眼睑闭合良好,外形满意。结论认为,较大范围的眼睑恶性肿瘤切除的患者,采用异体巩膜片移植、滑行结膜瓣前徙眼睑再造术能达到保持眼睑功能和美容的效果,是理想的眼睑恶性肿瘤切除后Ⅰ期修复临床决策。     

换脸术几个问题的理性思考

换脸术是目前国内外争论的一个焦点,是异体器官移植领域内新的突破,为严重毁容患者带来了重新获得美容的希望.但是目前还有很多问题需要进一步.在远期疗效尚未肯定的情况下,作为医务工作者,我们需要加强自身修养和伦理道德教育,做出正确的决定,并不断进行相关研究,最终广泛应用于临床,造福于人类.     

干细胞移植技术离临床治疗应用到底还有多远

骨髓细胞移植是一种早期的干细胞移植性治疗方式.干细胞分离纯化技术的革命,尤其是干细胞移植在各种临床疾病治疗中近期疗效的不断报道促成了干细胞移植技术的推广迅猛发展.胚胎干细胞或成体干细胞如何分化形成指定的有恰当功能的组织器官一直是发育生物学家和干细胞移植科学家们关注的重大研究课题.实际上,干细胞移植治疗既存在理论性困惑,又存在技术性问题,因此干细胞移植技术的实际应用前途是光明的,但道路是曲折的.     

我国开展活体小肠移植的现实和前景

1　我国开展活体小肠移植的必要性1.1　小肠移植是指将异体的一段小肠通过血管吻合、肠道重建的方式移植给由于各种原因而切除或损毁了大部或全部小肠患者的一门外科技术。小肠移植的适应症为各种原因引起的短肠综合征或肠功能不全 ,因经济或医疗问题 (出现并发症或已没有可输液的静脉 )而不能进行肠外营养 (ＴＰＮ )的患者。目前在我国虽然尚无确切的统计资料说明有多少患者需要进行小肠移植 ,但是根据Ｓｔｅｐｈｅｎ[1] 1997年对英国的统计依据推算 :在英国 ,每年每百万人口中有 1至 2人需要进行长期的肠外营养来维持生命 ,其中有近 1/2的…     

手近效应：研究内容、影响因素与神经机制

把手放在刺激旁边,会对知觉、记忆、语义和执行控制等认知加工产生影响,这类现象被称为手近效应。手近效应反映了身体与环境的互动对认知的塑造作用,为具身认知提供了新证据。本文从手近效应的内容,影响因素,及其认知、神经机制等方面对相关研究进行梳理。并从手近效应的神经机制,应用研究,以及动作意图和人际社会因素的调节作用等方面探讨当前手近效应还未解决的问题。     

The Rubber Hand Illusion: two's a company, but three's a crowd

On the one hand, it is often assumed that the Rubber Hand Illusion (RHI) is constrained by a structural body model so that one cannot implement supernumerary limbs. On the other hand, several recent studies reported illusory duplication of the right hand in subjects exposed to two adjacent rubber hands. The present study tested whether spatial constraints may affect the possibility of inducing the sense of ownership to two rubber hands located side by side to the left of the subject's hand. We found that only the closest rubber hand appeared both objectively (proprioceptive drift) and subjectively (ownership rating) embodied. Crucially, synchronous touch of a second, but farther, rubber hand disrupted the objective measure of the RHI, but not the subjective one. We concluded that, in order to elicit a genuine RHI for multiple rubber hands, the two rubber hands must be at the same distance from the subject's hand/body.     

Hand–foot motor priming in the presence of temporary inability to use hands

To verify if the link between observed hand actions and executed foot actions found in aplasics is essentially induced by the constant use of foot substituting the hand, we investigated if the vision of a grasping hand is able to prime a foot response in normals. Participants were required to detect the time-to-contact of a hand grasping an object either with a suitable or a less suitable movement, an experimental paradigm known to induce a priming effect. Participants responded either with the hand or the foot, while having free or bound hands. Results showed that for hand responses motor priming effect was stronger when the hands were free, whereas for foot responses it was stronger when the hands were bound. These data are interpreted as a further evidence that a difficulty to move affects specific cognitive functions and that the vision of a grasping hand may prime a foot response.     

Hand-foot motor priming in the presence of temporary inability to use hands

To verify if the link between observed hand actions and executed foot actions found in aplasics is essentially induced by the constant use of foot substituting the hand, we investigated if the vision of a grasping hand is able to prime a foot response in normals. Participants were required to detect the time-to-contact of a hand grasping an object either with a suitable or a less suitable movement, an experimental paradigm known to induce a priming effect. Participants responded either with the hand or the foot, while having free or bound hands. Results showed that for hand responses motor priming effect was stronger when the hands were free, whereas for foot responses it was stronger when the hands were bound. These data are interpreted as a further evidence that a difficulty to move affects specific cognitive functions and that the vision of a grasping hand may prime a foot response.     

Effects of posture on tactile localization by 4 years of age are modulated by sight of the hands: evidence for an early acquired external spatial frame of reference for touch

Adults show a deficit in their ability to localize tactile stimuli to their hands when their arms are in the less familiar, crossed posture. It is thought that this ‘crossed‐hands deficit’ arises due to a conflict between the anatomical and external spatial frames of reference within which touches can be encoded. The ability to localize a single tactile stimulus applied to one of the two hands across uncrossed‐hands and crossed‐hands postures was investigated in typically developing children (aged 4 to 6 years). The effect of posture was also compared across conditions in which children did, or did not, have visual information about current hand posture. All children, including the 4‐year‐olds, demonstrated the crossed‐hands deficit when they did not have sight of hand posture, suggesting that touch is located in an external reference frame by this age. In this youngest age group, when visual information about current hand posture was available, tactile localization performance was impaired specifically when the children's hands were uncrossed. We propose that this may be due to an early difficulty with integrating visual representations of the hand within the body schema.     

Determinants of hand attractiveness--a study involving digitally manipulated stimuli

Although attractiveness of the human hand is of significance in the social and mating context, thus far it has attracted little scientific interest. In this study, young women and men were presented with pairs of digitally manipulated images of opposite-sex hands and asked to indicate the hand perceived to be the more attractive in each pair. The hands within a pair differed from one another by a single feature: shape averageness, femininity, finger length, second-to-fourth-digit ratio, or skin smoothness. All these features, with the exception of the digit ratio, were shown to increase hand attractiveness in each sex in both dorsal and ventral views. Skin smoothness was preferred more strongly in female than in male hands. Women also tended to prefer medium degrees of shape femininity and skin smoothness in male hands compared to both high and low levels. Adaptive and non-adaptive (related to perceptual bias) mechanisms underlying these preferences are discussed.     

Asymmetric division of labor in human skilled bimanual action: the kinematic chain as a model

This article presents a tentative theoretical framework for the study of asymmetry in the context of human bimanual action. It is emphasized that in man most skilled manual activities involve two hands playing different roles, a fact that has been often overlooked in the experimental study of human manual lateralization. As an alternative to the current concepts of manual preference and manual superiority-whose relevance is limited to the particular case of unimanual actions-the more general concept of lateral preference is proposed to denote preference for one of the two possible ways of assigning two roles to two hands. A simple model describing man's favored intermanual division of labor in the model are the following. 1) The two hands represent two motors, that is, decomplexity is ignored in the suggested approach. 2) In man, the two manual motors cooperate with one another as if they were assembled in series, thereby forming a kinematic chain: In a right-hander allowed to follow his or her lateral preferences, motion produced by the right hand tends to articulate with motion produced by the left. It is suggested that the kinematic chain model may help in understanding the adaptive advantage of human manual specialization.     

Differential effect of one versus two hands on visual processing

Hand position in the visual field influences performance in several visual tasks. Recent theoretical accounts have proposed that hand position either (a) influences the allocation of spatial attention, or (b) biases processing toward the magnocellular visual pathway. Comparing these accounts is difficult as some studies manipulate the distance of one hand in the visual field while others vary the distance of both hands, and it is unclear whether single and dual hand manipulations have the same impact on perception. We ask if hand position affects the spatial distribution of attention, with a broader distribution of attention when both hands are near a visual display and a narrower distribution when one hand is near a display. We examined the effects of four hand positions near the screen (left hand, right hand, both hands, no hands) on both temporal and spatial discrimination tasks. Placing two hands near the display compared to two hands distant resulted in improved sensitivity for the temporal task and reduced sensitivity in the spatial task, replicating previous results. However, the single hand manipulations showed the opposite pattern of results. Together these results suggest that visual attention is focused on the graspable space for a single hand, and expanded when two hands frame an area of the visual field.     

Integration of hand and finger location in external spatial coordinates for tactile localization

Tactile stimulus location is automatically transformed from somatotopic into external spatial coordinates, rendering information about the location of touch in three-dimensional space. This process is referred to as tactile remapping. Whereas remapping seems to occur automatically for the hands and feet, the fingers may constitute an exception in that some studies have implied purely somatotopic coding of touch to the fingers. When participants judge the order of two tactile stimuli, they often err when the stimulated body parts (usually the two hands) are crossed, presumably because somatotopic and external coordinates are in conflict in crossed postures. Using this task, we investigated, first, whether the fingers are unlike other limbs with regard to spatial coding, by testing whether crossing effects, indicative of external coding, were observable when stimulating two fingers, either on the same or on different hands. Second, we investigated the interaction of hand and finger posture in tactile localization of finger stimuli. Crossing effects emerged when fingers and hands were crossed, suggesting external coding for all body parts. Crossing effects were larger when both hand and finger were located in the hemifield opposite to their body side, and smaller when only hand or finger lay in the opposite hemifield. We suggest that tactile location is estimated by integrating the external location of all relevant body parts, here of a finger and its belonging hand, and that such integrative coding may represent a general principle for body part processing as well as for tool use.     

Music during learning of a tactual-spatial task affects later response generalization

Equal numbers of men and women learned a finger maze, with half of the subjects initially using their right hands and the other half using their left hands. To reach criterion, subjects receiving music in the ear ipsilateral to the hand used required more trials than did those receiving no music. Furthermore, when the right hand ran the maze, music played to the ipsilateral ear also delayed learning, compared with music played contralaterally. Binaural music delayed learning when the left hand was used but not when the right hand was used. Possible causes of these effects are suggested. When subjects switched hands and relearned the maze, the number of trials to criterion depended on the group subjects were in during initial learning and not on the group they were in during the hand reversal (response generalization) trials. Although the music condition used determined the effect of music on initial learning and on response generalization, some evidence is presented that indicates that the two effects are not entirely interdependent and that they may even involve different mechanisms.