Abstract& We used fMRI to explore the neural substrates involved in the unconscious evaluation of Black and White social groups. Specifically, we focused on the amygdala, a subcortical structure known to play a role in emotional learning and evaluation. In Experiment 1, White American subjects observed faces of unfamiliar Black and White males. The strength of amygdala activation to Black-versus-White faces was correlated with two indirect (unconscious) measures of race evaluation (Implicit Association Test [IAT] and potentiated startle), but not with the direct (conscious) expression of race attitudes. In Experiment 2, these patterns were not obtained when the stimulus faces belonged to familiar and positively regarded Black and White individuals. Together, these results suggest that amygdala and behavioral responses to Black-versus-White faces in White subjects reflect cultural evaluations of social groups modified by individual experience. &

We examined the neural substrates involved when subjects encountered an event linked verbally, but not experientially, to an aversive outcome. This instructed fear task models a primary way humans learn about the emotional nature of events. Subjects were told that one stimulus (threat) represents an aversive event (a shock may be given), whereas another (safe) represents safety (no shock will be given). Using functional magnetic resonance imaging (fMRI), activation of the left amygdala was observed in response to threat versus safe conditions, which correlated with the expression of the fear response as measured by skin conductance. Additional activation observed in the insular cortex is proposed to be involved in conveying a cortical representation of fear to the amygdala. These results suggest that the neural substrates that support conditioned fear across species have a similar but somewhat different role in more abstract representations of fear in humans.

A national conference on organ donation after cardiac death (DCD) was convened to expand the practice of DCD in the continuum of quality end-of-life care.This national conference affirmed the ethical propriety of DCD as not violating the dead donor rule. Further, by new developments not previously reported, the conference resolved controversy regarding the period of circulatory cessation that determines death and allows administration of pre-recovery pharmacologic agents, it established conditions of DCD eligibility, it presented current data regarding the successful transplantation of organs from DCD, it proposed a new framework of data reporting regarding ischemic events, it made specific recommendations to agencies and organizations to remove barriers to DCD, it brought guidance regarding organ allocation and the process of informed consent and it set an action plan to address media issues. When a consensual decision is made to withdraw life support by the attending physician and patient or by the attending physician and a family member or surrogate (particularly in an intensive care unit), a routine opportunity for DCD should be available to honor the deceased donor's wishes in every donor service area (DSA) of the United States. Key words: Deceased organ donation Received 25 July 2005, revised and accepted for publication 24 October 2005A national conference on organ donation after cardiac death (DCD) was convened in Philadelphia on April 7 and 8, 2005, to address the increasing experience of DCD and to affirm the ethical propriety of transplanting organs from such donors. Participants represented the broad spectrum of the medical community, including neuroscientists, critical care professionals and distinguished bioethicists (Appendix 1).Six work groups were assembled to address specific DCD issues and fulfill the conference objectives: (i) determining death by a cardiopulmonary criterion, (ii) assessing medical criteria that predict DCD candidacy following the withdrawal of life support, (iii) reviewing protocols for successful DCD organ recovery and subsequent transplantation, (iv) initiating DCD in donation service areas (DSAs), (v) discussing the allocation of DCD organs for transplantation and (vi) examining perceptions of DCD held by the media and the public. Work Group 1: Determining Death by a Cardiopulmonary CriterionA prospective organ donor's death may be determined by either cardiopulmonary (DCD) or neurologic criteria (donation after brain death [DBD]) (1). The term donation after cardiac death (DCD) clearly indicates that death precedes donation. Death determination in the DCD patient mandates the use of a cardiopulmonary criterion to prove the absence of circulation. The cardiopulmonary criterion may be used when the donor does not fulfill brain death criteria. The ethical axiom of organ donation necessitates adherence to the dead donor rule: the retrieval of organs for transplantation should not cause the death of a donor (2).In clinical situations that fulfill either brain death criteria ...

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This document was developed through the collaborative efforts of the Society of Critical Care Medicine, the American College of Chest Physicians, and the Association of Organ Procurement Organizations. Under the auspices of these societies, a multidisciplinary, multi-institutional task force was convened, incorporating expertise in critical care medicine, organ donor management, and transplantation. Members of the task force were divided into 13 subcommittees, each focused on one of the following general or organ-specific areas: death determination using neurologic criteria, donation after circulatory death determination, authorization process, general contraindications to donation, hemodynamic management, endocrine dysfunction and hormone replacement therapy, pediatric donor management, cardiac donation, lung donation, liver donation, kidney donation, small bowel donation, and pancreas donation. Subcommittees were charged with generating a series of management-related questions related to their topic. For each question, subcommittees provided a summary of relevant literature and specific recommendations. The specific recommendations were approved by all members of the task force and then assembled into a complete document. Because the available literature was overwhelmingly comprised of observational studies and case series, representing low-quality evidence, a decision was made that the document would assume the form of a consensus statement rather than a formally graded guideline. The goal of this document is to provide critical care practitioners with essential information and practical recommendations related to management of the potential organ donor, based on the available literature and expert consensus.