Machine perfusion and assessment of NHBD kidneys has been successfully introduced to the Newcastle NHBD programme. This approach, using renal transplants from largely category II donors produced a success rate of 88.4% which was significantly better than the phase II period (45.5%) of the program (p=0.023, Fisher 2 tail test).

No abstract

Chronic allograft nephropathy (CAN) is a major cause of graft loss after renal transplantation. Implicated in the pathogenesis of this complication is overproduction of the cytokine transforming growth factor beta (TGF β). In this study we measured changes in CAN's expression in stable patients early after transplantation, and studied links with established risk factors for CAN, such as delayed graft function, acute rejection, and cyclosporine exposure. We took biopsies from 40 renal allografts at time of transplantation (pre‐perfusion), and then, using ultrasound guidance, at 1 week and 6 months after transplantation. An immunofluorescence technique was used to stain sections for active TGF β. These were then assessed by semi‐quantitative scanning laser confocal microscopy. There was very little variation in active TGF‐β expression among patients in their pre‐perfusion biopsies. Expression had increased by 1 week and then very significantly by 6 months (P<0.0001). Patients who suffered delayed graft function had increased TGF‐β expression at both time points. There was no difference regarding donor type, acute rejection, and immunosuppressive drug (cyclosporine or tacrolimus). There was no correlation between the amount of TGF‐β expression at any time‐point and isotope glomerular filtration rate (GFR) at 12 months. This study demonstrated that in a group of stable renal allograft recipients, TGF‐β expression in the kidney increased after transplantation. As the study used protocol biopsies, this increase is unlikely to be due to acute events, and probably represents a genuine increase.

In recent years, integrated passive components technology has gained significant popularity in integrated drives research. An integrated drive may be considered to be a full mechanical integration of the machine, power electronic converter and passive components into a single package. This approach is important for applications such as traction motors, aerospace, electric vehicles and cars where space, mass or volume constraints are high. Incorporation of electromagnetic components, such as line filters, into electric machines can be achieved by sharing the existing machine's magnetic circuit with the filter component. In this paper part of an LCL line filter has been chosen to be integrated with a permanent magnet synchronous machine. An LCL filter has been selected as it has lower inductance compared to other input filter types such as LC and L filters. This paper also presents a several novel techniques for integrating the largest portion of LCL input power filter which is the 3-phase ac inductors located in the drive side producing a single mechanically packaged unit without significant increase in size and loss which in turn achieves high power density. Different integrated 3-phase input inductors designs have been simulated with finite element analysis to prove the effectiveness of integration of passives within the machine structure. In each case the design has been iteratively optimised to determine the optimal mass of copper and core for the integrated filter inductors targeting parity in power density when compared to a traditionally separated package. The paper demonstrates that an approach utilising a double slot machine with input filters wound into the outermost slots was the most appropriate choice in terms of power density compared to other proposed methods.

Due to a shortage of organs for transplantation, many centres use marginal grafts to increase their donor pool. As kidneys from non-heart-beating donors (NHBD) have sustained initial ischaemic damage, their viability is difficult to predict. Hypothermic pulsatile perfusion has not only been used to improve the condition of such grafts, but also allows viability assessment. Suitable systems are becoming more readily available, but they are expensive. We have used existing dialysis equipment with modified sterilised inserts to create a pulsatile hypothermic perfusion system. With this system, 41 NHBD kidneys were perfused for up to 8 h; their intravascular renal resistance (IRVR), flow characteristics as well as glutathione S transferase (GST) measurements were performed to assess viability. This hypothermic pulsatile perfusion system is now an integral component of our NHBD programme.

Chronic rejection accounts for the greatest loss of renal allografts. HLA mismatching has been minimised by organ allocation and new immunosuppressive drugs have been employed, but the average cadaveric graft survival still does not exceed 12 years. Though the aetiology is multifactorial, one contributory factor for this condition is cytomegalovirus (CMV). Detection of CMV in kidney biopsies and sera can diagnose and monitor this inflammatory event and define its role in chronic nephropathy. Twenty five biopsies taken at the time of transplantation, 10 biopsies for graft dysfunction and tissue blocks from 20 explanted kidney grafts were collected and investigated for CMV antigens by immunohistochemistry. Tissue samples were snap frozen and cryostat sections were incubated with monoclonal antibodies for CMV antigens followed by immunoperoxidase staining. In 12 out of 20 transplant nephrectomies CMV antigens were found. Only two of these patients had clinical CMV disease. Time 0 biopsies from CMV seronegative donors (n = 11) and CMV seropositive donors (n = 14) were negative for CMV antigens. The prevalence of CMV antigens in grafts lost due to chronic rejection was 60%. These antigens were not found within the time 0 biopsies, but were detected in 30% of biopsies taken at the time of clinical graft dysfunction. CMV appears to contribute to chronic rejection even without clinical disease.

No abstract

Due to a shortage of organs for transplantation, many centres use marginal grafts to increase their donor pool. As kidneys from non-heart-beating donors (NHBD) have sustained initial ischaemic damage, their viability is difficult to predict. Hypothermic pulsatile perfusion has not only been used to improve the condition of such grafts, but also allows viability assessment. Suitable systems are becoming more readily available, but they are expensive. We have used existing dialysis equipment with modified sterilised inserts to create a pulsatile hypothermic perfusion system. With this system, 41 NHBD kidneys were perfused for up to 8 h; their intravascular renal resistance (IRVR), flow characteristics as well as glutathione S transferase (GST) measurements were performed to assess viability. This hypothermic pulsatile perfusion system is now an integral component of our NHBD programme.