The Prolonged Masking of Temporal Acoustic Inputs with Noise Drives Plasticity in the Adult Rat Auditory Cortex.

The prolonged masking of auditory inputs with white noise has been shown to reopen the critical period for spectral tuning in the adult rat auditory cortex. Here, we argue that the masking of salient temporal inputs in particular is responsible for changes in neuronal activity that lead to this experience-dependent plasticity. We tested this hypothesis by passively exposing adult rats to 2 weeks of amplitude-modulated (AM) white noise with different modulation depths from 0% (no modulation) to 100% (strong modulation). All exposed rats displayed evidence of cortical plasticity as measured by receptive field bandwidths, tonotopic gradients, and synchronization during spontaneous activity. However, this plasticity was fundamentally different in nature for rats exposed to unmodulated noise, as a second passive exposure to pure tones elicited tonotopic reorganization in rats exposed to 0% AM noise only. Detection of c-FOS expression in excitatory and inhibitory cells through post-mortem immunohistochemistry also revealed different patterns of cellular activation depending on modulation depth. Together, these results indicate that the absence of temporal modulation promotes noise-induced plasticity in the adult auditory cortex and suggest an important and continuous role for temporally salient inputs in the maintenance of mature auditory circuits.

Successful international collaboration improves family donation conversations resulting in increased organ donation.

INTRODUCTION: Australian donation leaders recognized that to increase organ donation outcomes, health professionals conducting family donation conversations (FDCs) required support and specialist training. An international training institute with programs based on proven results was engaged to create and implement a customized training program to influence change in FDC practice and culture. The goal was to increase donation rates by developing and implementing a customized, self-sustaining training program to enhance FDC practices of health professionals. Other goals included providing training and communications skills to lead FDC, supporting families in making decisions, and influencing health professionals to adopt FDC practices. MATERIALS AND METHODS: To gain support and determine program suitability, two 1-day pilot training sessions were provided to 45 Australian donation leaders in 2011. Training was further customized with an emphasis on creating changes to achieve and sustain desired results. A comprehensive national training plan was implemented over 18 months. Twenty-six 2-day FDC training workshops were held in 8 cities (646 participants). Program evaluations and debriefings showed distinct shifts in perspectives and an enthusiasm to implement new processes. In 2012 to 2013, an instructor program was developed to transition training facilitation. The training institute remains involved in development and training to build and sustain skill and expertise. RESULTS: There was a 58% increase in organ donors in Australia from 2009 to 2013 (data reflect 2013 Australian end-of-year organ donation information). This represents a 36% increase in organ donors (2009-2011); the remaining 22% increase was achieved in the 2 years since the FDC training was implemented in Australia (2011-2013). CONCLUSIONS: Improved skills training in the conduct of FDCs seem to have contributed to improved donation outcomes in national identification, request, and consent rates. The integration of another organization's process poses distinct challenges; thoughtful collaboration, sensitive to cultural aspects and family care, communication, and donation practices, can result in successful customized training that shifts perspectives, provides new skills, and achieves and sustains an increase in organ donation rates.

Controlled non-heart-beating donor liver transplantation: a successful single center experience, with topic update.

BACKGROUND: The critical shortage of transplantable organs necessitates utilization of unconventional donors. We describe a successful experience of controlled non-heart-beating donor (NHBD) liver transplantation. METHODS: Controlled NHBDs had catastrophic head injury, prognosis for no meaningful recovery, decision to withdraw life support, and subsequent consent for donation. After stopping mechanical ventilation in the operating room, death determination by a nontransplant caregiver, and rapid aortic cannulation, liver and kidneys were recovered. RESULTS: Controlled NHBDs contributed 5% of hepatic allografts (8/164) from August 1996 through June 1999 (9% in 1998). Sixteen NHBDs afforded 8 livers and 24 kidneys. Liver donors (n=8) were 11-66 years old; half were >50 years old. Premortem alanine aminotransferase was 25-157 U/L. Arrest occurred 3-27 min after stopping ventilation. Perfusion started 3-5 min after incision, and <22 min after hypotension (mean arterial pressure: <50 mmHg). Patient and graft survivals are 100% at 18+/-12 months follow-up. There was no intraoperative complication, reperfusion syndrome, poor graft function, primary nonfunction, arterial thrombosis, biliary complication, or serious infection. Postoperative day 2 prothrombin time was 13+/-1 sec. Peak alanine aminotransferase was 980+/-601 U/L. Intensive care unit and posttransplant lengths of stay were 2+/-2 and 10+/-7 days, respectively. Soon after transplantation there was frequent temporary hyperbilirubinemia (five of eight recipients; bilirubin peak: 7-29 mg/dl, 2-3 weeks after transplantation) and rejection (4/8 recipients, <3 weeks after transplantation). CONCLUSIONS: NHBDs significantly and safely expanded our donor pool. NHBD surgeons must be capable of rapid procurement. Cautious liberalization of criteria for accepting livers from NHBDs with confounding risk factors is justified. Refined ethics guidelines would broaden approval of NHBDs.

Centralization of histocompatibility laboratories: impact on organ allocation efficiency and outcomes of cadaveric renal transplantation.

This project was undertaken to determine whether centralization of histocompatibility laboratory services for renal transplants performed within eastern Pennsylvania could improve the efficiency of allograft allocation and short-term allograft function. A nonconcurrent cohort study was performed comparing renal allografts transplanted between September 15, 1993, and September 14, 1994, to those transplanted between September 15, 1994, and September 14, 1995. All allografts were procured and allocated by the Delaware Valley Transplant Program, the organ procurement agency in eastern Pennsylvania. Cold preservation time and delayed allograft function were used to measure efficiency of allograft allocation and short term allograft function, respectively. The mean cold preservation time was reduced from 25.08 hours to 20.68 hours (P < 0.001). The percentage of delayed allograft function was 19.9 and 17.4 for the pre- and postcentralization groups, respectively (P = 0.5). Therefore, centralization of histocompatibility tissue typing was a regionally effective process intervention for reducing cold preservation time without adversely impacting short-term graft function. The magnitude of this reduction varied between individual centers. Further investigation is required to determine the effect on long-term allograft function and system wide costs.

Successful donation and transplantation of multiple organs from a victim of cyanide poisoning.

Demand for viable human organs for transplantation continues to exceed the supply. To expand supply, the criteria for identification and management of suitable donors must continue to evolve. Poisoned patients are often excluded as potential organ donors due to perceived risks of transmittable agents and/or physiologically compromised organs. In this report, a patient succumbed after an intentional ingestion of cyanide and multiple pharmaceuticals. Donor organ viability was determined by lack of significant injury beyond the central nervous system. Following standard procurement procedures, the heart, liver, corneas, 16 skin grafts and 16 bone grafts were deemed suitable and successfully transplanted. All organ recipients were doing well eight months post transplantation. The focus of procurement personnel should be on tissue injury and not on the mere presence of clinical effect of a toxic agent. With the paucity of organs available, poison centers need to be cognizant of this dilemma when faced with a toxicologically compromised potential organ donor.

Estimation and characterization of the potential renal organ donor pool in Pennsylvania. Report of the Pennsylvania Statewide Donor Study.

The Pennsylvania Statewide Donor Study evaluated deaths under the age of 66 occurring in 149 participating hospitals in 1987. After elimination of 6146 patients from 11,983 based upon ICD-9 code criteria, an on-site medical record review was performed on 5603 patients. Each patient was assessed for organ donor suitability based upon brain death and medical suitability criteria--and, after a series of eliminations, 453 patients were found to have a moderate or higher potential as acceptable organ donors. An estimation of the organ donor rate was placed between 38.3 and 55.2 donors per million population per year, depending upon the stringency of organ donor criteria. Educational efforts targeted at physicians, patient's families and transplant surgeons will be necessary, however, to attain this maximal rate.