Composite Tissue Allotransplantation: Current Challenges
ABSTRACT Composite tissue allotransplantation (CTA) in the clinic is taking firm root. Success at hand, face, knee, trachea, and laryngeal transplantation has led to widespread interest and increasing application. Despite this, skepticism is common, particularly in the realm of reconstructive surgeons. The risks of immunosuppression remain a barrier to the advancement of the field, as these are perceived by many to be prohibitive. Significant progress in the field require the development of newer immunosuppressive agents with less toxicity and methods to achieve donor specific tolerance. This review focuses on the current state of CTA-both in the clinic and the laboratory. A thorough understanding of the immunology of CTA will allow the widespread application of this promising field.
- SourceAvailable from: Kadiyala V Ravindra
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- "The majority of patients undergoing VCA have received T-cell depleting induction therapy . Despite this aggressive immunosuppressive therapy, episodes of acute rejection have been recorded in 85% of hand and 54.5% of face transplant recipients in the first year after the transplant   . Thus the incidence of acute rejection following VCA transplantation is significantly higher than that seen currently with solid organ transplantation—the overall incidence of acute rejection within the first year after renal transplantation is now less than 15% . "
ABSTRACT: Successful hand and face transplantation in the last decade has firmly established the field of vascularized composite allotransplantation (VCA). The experience in VCA has thus far been very similar to solid organ transplantation in terms of the morbidity associated with long-term immunosuppression. The unique immunological features of VCA such as split tolerance and resistance to chronic rejection are being investigated. Simultaneously there has been laboratory work studying tolerogenic protocols in animal VCA models. In order to optimize VCA outcomes, translational studies are needed to develop less toxic immunosuppression and possibly achieve donor-specific tolerance. This article reviews the immunology, animal models, mixed chimerism & tolerance induction in VCA and the direction of future research to enable better understanding and wider application of VCA.Clinical and Developmental Immunology 10/2012; 2012:438078. DOI:10.1155/2012/438078 · 2.93 Impact Factor
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ABSTRACT: Situations that highlight the healthcare team member vulnerability, present ethically laden questions, or are innovative in nature may have a long-term personal and professional impact on caregivers and, consequently, directly or indirectly affect patient care. The ethical experiences and perceptions of the healthcare team members involved in facial transplantation procedures and patient care have not been explored. The objective of this study was to explore healthcare team member experiences of caring for facial transplantation patients, using an ethical framework. This study used a qualitative descriptive design to explore the experiences of 26 multidisciplinary healthcare team members, including professional, ancillary, and support staff who have participated in facial transplantation procedures and patient care. Individual, private, semistructured interviews were conducted. Two main themes emerged: individual sense of purpose and esprit de corps. Individual sense of purpose describes the meaning of the experience that involvement in facial transplantation had for the participants and comprises three subthemes: "getting it right, "transforming a life," and "spirituality." The theme esprit de corps conveys the morale of the healthcare team members involved in facial transplantation and was expressed through three subthemes: "leadership," "teamwork," and "environment." Many potential ethical dilemmas were mitigated by an overwhelming sense of moral obligation to help patients with complex cosmetic, functional, and mechanical facial deficits. Participants in this study unanimously believed that the risk-benefit ratio of the procedure and subsequent treatment supported its implementation.Nursing research 01/2013; 62(6):372-82. DOI:10.1097/01.NNR.0000434616.93493.e2 · 1.50 Impact Factor
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ABSTRACT: The authors discuss and compare several representative modulation techniques for IM/DD (intensity modulation/direct detection) systems, focusing on their tolerance of fiber chromatic dispersion. The modulation techniques examined are direct intensity modulation of the laser diode, Mach-Zehnder interferometer external modulation, electroabsorption external modulation and direct-phase-shift and self-homodyne intensity modulation (DPSH-IM). The authors discuss the impact of these techniques on the performance of long-haul systems using optical amplifiers. A 12-Gb/s transmission experiment using an Er-doped fiber amplifier is also described. External modulation and DPSH-IM seem to be more promising than conventional direct intensity modulation for multigigabit long-span transmission systems using optical amplifiersCommunications, 1990. ICC '90, Including Supercomm Technical Sessions. SUPERCOMM/ICC '90. Conference Record., IEEE International Conference on; 05/1990