Robotic versus laparoscopic versus open nephrectomy for live kidney donors

BACKGROUND

Waiting lists for kidney transplantation continue to grow. Live kidney donation significantly reduces waiting times and improves long-term outcomes for recipients. Major disincentives to potential kidney donors are the pain and morbidity associated with surgery. This is an update of a review published in 2011.

OBJECTIVES

To assess the benefits and harms of open donor nephrectomy (ODN), laparoscopic donor nephrectomy (LDN), hand-assisted LDN (HALDN) and robotic donor nephrectomy (RDN) as appropriate surgical techniques for live kidney donors.

SEARCH METHODS

We contacted the Information Specialist and searched the Cochrane Kidney and Transplant Register of Studies up to 31 March 2024 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing LDN with ODN, HALDN, or RDN were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for eligibility, assessed study quality, and extracted data. We contacted study authors for additional information where necessary. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Thirteen studies randomising 1280 live kidney donors to ODN, LDN, HALDN, or RDN were included. All studies were assessed as having a low or unclear risk of bias for selection bias. Five studies had a high risk of bias for blinding. Seven studies randomised 815 live kidney donors to LDN or ODN. LDN was associated with reduced analgesia use (high certainty evidence) and shorter hospital stay, a longer procedure and longer warm ischaemia time (moderate certainty evidence). There were no overall differences in blood loss, perioperative complications, or need for operations (low or very low certainty evidence). Three studies randomised 270 live kidney donors to LDN or HALDN. There were no differences between HALDN and LDN for analgesia requirement, hospital stay (high certainty evidence), duration of procedure (moderate certainty evidence), blood loss, perioperative complications, or reoperations (low certainty evidence). The evidence for warm ischaemia time was very uncertain due to high heterogeneity. One study randomised 50 live kidney donors to retroperitoneal ODN or HALDN and reported less pain and analgesia requirements with ODN. It found decreased blood loss and duration of the procedure with HALDN. No differences were found in perioperative complications, reoperations, hospital stay, or primary warm ischaemia time. One study randomised 45 live kidney donors to LDN or RDN and reported a longer warm ischaemia time with RDN but no differences in analgesia requirement, duration of procedure, blood loss, perioperative complications, reoperations, or hospital stay. One study randomised 100 live kidney donors to two variations of LDN and reported no differences in hospital stay, duration of procedure, conversion rates, primary warm ischaemia times, or complications (not meta-analysed). The conversion rates to ODN were 6/587 (1.02%) in LDN, 1/160 (0.63%) in HALDN, and 0/15 in RDN. Graft outcomes were rarely or selectively reported across the studies. There were no differences between LDN and ODN for early graft loss, delayed graft function, acute rejection, ureteric complications, kidney function or one-year graft loss. In a meta-regression analysis between LDN and ODN, moderate certainty evidence on procedure duration changed significantly in favour of LDN over time (yearly reduction = 7.12 min, 95% CI 2.56 to 11.67; P = 0.0022). Differences in very low certainty evidence on perioperative complications also changed significantly in favour of LDN over time (yearly change in LnRR = 0.107, 95% CI 0.022 to 0.192; P = 0.014). Various different combinations of techniques were used in each study, resulting in heterogeneity among the results.

AUTHORS' CONCLUSIONS

LDN is associated with less pain compared to ODN and has comparable pain to HALDN and RDN. HALDN is comparable to LDN in all outcomes except warm ischaemia time, which may be associated with a reduction. One study reported kidneys obtained during RDN had greater warm ischaemia times. Complications and occurrences of perioperative events needing further intervention were equivalent between all methods.

Multi-Centre UK Analysis of Simultaneous Pancreas and Kidney (SPK) Transplant in Recipients With Type 2 Diabetes Mellitus

90% of the UK diabetic population are classified as T2DM. This study aims to compare outcomes after SPK transplant between recipients with T1DM or T2DM. Data on all UK SPK transplants from 2003-2019 were obtained from the NHSBT Registry (n = 2,236). Current SPK transplant selection criteria for T2DM requires insulin treatment and recipient BMI < 30 kg/m2. After exclusions (re-transplants/ambiguous type of diabetes) we had a cohort of n = 2,154. Graft (GS) and patient (PS) survival analyses were conducted using Kaplan-Meier plots and Cox-regression models. Complications were compared using chi-squared analyses. 95.6% of SPK transplants were performed in recipients with T1DM (n = 2,060). Univariate analysis showed comparable outcomes for pancreas GS at 1 year (p = 0.120), 3 years (p = 0.237), and 10 years (p = 0.196) and kidney GS at 1 year (p = 0.438), 3 years (p = 0.548), and 10 years (p = 0.947). PS was comparable at 1 year (p = 0.886) and 3 years (p = 0.237) and at 10 years (p = 0.161). Multi-variate analysis showed comparable outcomes in pancreas GS (p = 0.564, HR 1.221, 95% CI 0.619, 2.406) and PS(p = 0.556, HR 1.280, 95% CI 0.563, 2.911). Comparable rates of common complications were demonstrated. This is the largest series outside of the US evaluating outcomes after SPK transplants and shows similar outcomes between T1DM and T2DM recipients. It is hoped dissemination of this data will lead to increased referral rates and assessment of T2DM patients who could benefit from SPK transplantation.

Donor Liver Blood Tests and Liver Transplant Outcomes: UK Registry Cohort Study

BACKGROUND

Safely increasing organ utilization is a global priority. Donor serum transaminase levels are often used to decline livers, despite minimal evidence to support such decisions. This study aimed to investigate the impact of donor "liver blood tests" on transplant outcomes.

METHODS

This retrospective cohort study used the National Health Service registry on adult liver transplantation (2016-2019); adjusted regressions models were used to assess the effect of donor "liver blood tests" on outcomes.

RESULTS

A total of 3299 adult liver transplant recipients were included (2530 following brain stem death, 769 following circulatory death). Peak alanine transaminase (ALT) ranged from 6 to 5927 U/L (median = 45). Donor cause of death significantly predicted donor ALT; 4.2-fold increase in peak ALT with hypoxic brain injury versus intracranial hemorrhage (adjusted P  < 0.001). On multivariable analysis, adjusting for a wide range of factors, transaminase level (ALT or aspartate aminotransferase) failed to predict graft survival, primary nonfunction, 90-d graft loss, or mortality. This held true in all examined subgroups, that is, steatotic grafts, donation following circulatory death, hypoxic brain injury donors, and donors, in which ALT was still rising at the time of retrieval. Even grafts from donors with extremely deranged ALT (>1000 U/L) displayed excellent posttransplant outcomes. In contrast, donor peak alkaline phosphatase was a significant predictor of graft loss (adjusted hazard ratio = 1.808; 1.016-3.216; P  = 0.044).

CONCLUSIONS

Donor transaminases do not predict posttransplant outcomes. When other factors are favorable, livers from donors with raised transaminases can be accepted and transplanted with confidence. Such knowledge should improve organ utilization decision-making and prevent future unnecessary organ discard. This provides a safe, simple, and immediate option to expand the donor pool.

Machine perfusion in liver transplantation

BACKGROUND

Liver transplantation is the only chance of cure for people with end-stage liver disease and some people with advanced liver cancers or acute liver failure. The increasing prevalence of these conditions drives demand and necessitates the increasing use of donated livers which have traditionally been considered suboptimal. Several novel machine perfusion preservation technologies have been developed, which attempt to ameliorate some of the deleterious effects of ischaemia reperfusion injury. Machine perfusion technology aims to improve organ quality, thereby improving outcomes in recipients of suboptimal livers when compared to traditional static cold storage (SCS; ice box).

OBJECTIVES

To evaluate the effects of different methods of machine perfusion (including hypothermic oxygenated machine perfusion (HOPE), normothermic machine perfusion (NMP), controlled oxygenated rewarming, and normothermic regional perfusion) versus each other or versus static cold storage (SCS) in people undergoing liver transplantation.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 10 January 2023.

SELECTION CRITERIA

We included randomised clinical trials which compared different methods of machine perfusion, either with each other or with SCS. Studies comparing HOPE via both hepatic artery and portal vein, or via portal vein only, were grouped. The protocol detailed that we also planned to include quasi-randomised studies to assess treatment harms.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. overall participant survival, 2. quality of life, and 3. serious adverse events. Secondary outcomes were 4. graft survival, 5. ischaemic biliary complications, 6. primary non-function of the graft, 7. early allograft function, 8. non-serious adverse events, 9. transplant utilisation, and 10. transaminase release during the first week post-transplant. We assessed bias using Cochrane's RoB 2 tool and used GRADE to assess certainty of evidence.

MAIN RESULTS

We included seven randomised trials (1024 transplant recipients from 1301 randomised/included livers). All trials were parallel two-group trials; four compared HOPE versus SCS, and three compared NMP versus SCS. No trials used normothermic regional perfusion. When compared with SCS, it was uncertain whether overall participant survival was improved with either HOPE (hazard ratio (HR) 0.91, 95% confidence interval (CI) 0.42 to 1.98; P = 0.81, I2 = 0%; 4 trials, 482 recipients; low-certainty evidence due to imprecision because of low number of events) or NMP (HR 1.08, 95% CI 0.31 to 3.80; P = 0.90; 1 trial, 222 recipients; very low-certainty evidence due to imprecision and risk of bias). No trials reported quality of life. When compared with SCS alone, HOPE was associated with improvement in the following clinically relevant outcomes: graft survival (HR 0.45, 95% CI 0.23 to 0.87; P = 0.02, I2 = 0%; 4 trials, 482 recipients; high-certainty evidence), serious adverse events in extended criteria DBD liver transplants (OR 0.45, 95% CI 0.22 to 0.91; P = 0.03, I2 = 0%; 2 trials, 156 participants; moderate-certainty evidence) and clinically significant ischaemic cholangiopathy in recipients of DCD livers (OR 0.31, 95% CI 0.11 to 0.92; P = 0.03; 1 trial, 156 recipients; high-certainty evidence). In contrast, NMP was not associated with improvement in any of these clinically relevant outcomes. NMP was associated with improved utilisation compared with SCS (one trial found a 50% lower rate of organ discard; P = 0.008), but the reasons underlying this effect are unknown. We identified 11 ongoing studies investigating machine perfusion technologies.

AUTHORS' CONCLUSIONS

In situations where the decision has been made to transplant a liver donated after circulatory death or donated following brain death, end-ischaemic HOPE will provide superior clinically relevant outcomes compared with SCS alone. Specifically, graft survival is improved (high-certainty evidence), serious adverse events are reduced (moderate-certainty evidence), and in donors after circulatory death, clinically relevant ischaemic biliary complications are reduced (high-certainty evidence). There is no good evidence that NMP has the same benefits over SCS in terms of these clinically relevant outcomes. NMP does appear to improve utilisation of grafts that would otherwise be discarded with SCS; however, the reasons for this, and whether this effect is specific to NMP, is not clear. Further studies into NMP viability criteria and utilisation, as well as head-to-head trials with other perfusion technologies are needed. In the setting of donation following circulatory death transplantation, further trials are needed to assess the effect of these ex situ machine perfusion methods against, or in combination with, normothermic regional perfusion.

Fibrin-based haemostatic agents for reducing blood loss in adult liver resection

BACKGROUND

Liver resection is the optimal treatment for selected benign and malignant liver tumours, but it can be associated with significant blood loss. Numerous anaesthetic and surgical techniques have been developed to reduce blood loss and improve perioperative outcomes. One such technique is the application of topical fibrin-based haemostatic agents (FBHAs) to the resection surface. There is no standard practice for FBHA use, and a variety of commercial agents and devices are available, as well as non-FBHAs (e.g. collagen-based agents). The literature is inconclusive on the effectiveness of these methods and on the clinical benefits of their routine use.

OBJECTIVES

To evaluate the benefits and harms of fibrin-based haemostatic agents in reducing intraoperative blood loss in adults undergoing liver resection.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group (CHBG) Controlled Trials Register, CENTRAL, MEDLINE, Embase, LILACS, Science Citation Index Expanded, and Conference Proceedings Citation Index-Science up to 20 January 2023. We also searched online trial registries, checked the reference lists of all primary studies, and contacted the authors of included trials for additional published or unpublished trials.

SELECTION CRITERIA

We considered for inclusion all randomised clinical trials evaluating FBHAs versus no topical intervention or non-FBHAs, irrespective of publication type, publication status, language of publication, and outcomes reported. Eligible participants could have any liver pathology and be undergoing major or minor liver resections through open or laparoscopic surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the results of the literature search and used data extraction forms to collate the results. We expressed dichotomous outcome results as risk ratios (RRs) and continuous outcome results as mean differences (MDs), each with their corresponding 95% confidence interval (CI). We used a random-effects model for the main analyses. Our primary outcomes were perioperative mortality, serious adverse events, haemostatic efficacy, and health-related quality of life. Our secondary outcomes were efficacy as sealant, adverse events considered non-serious, operating time, and length of hospital stay. We assessed the certainty of the evidence with GRADE and presented results in two summary of findings tables.

MAIN RESULTS

We included 22 trials (2945 participants) evaluating FBHAs versus no intervention or non-FBHAs; 19 trials with 2642 participants provided data for the meta-analyses. Twelve trials reported commercial funding, one trial reported no financial support, and nine trials provided no information on funding. Below we present the most clinically relevant outcome results, also displayed in our summary of findings table. Fibrin-based haemostatic agents versus no intervention Six trials (1001 participants) compared FBHAs with no intervention. One trial was at low risk of bias in all five domains, and all other trials were at high or unclear risk of bias in at least one domain. Two trials were at high risk of bias related to blinding. It is unclear if FBHAs compared with no intervention have an effect on perioperative mortality (RR 2.58, 95% CI 0.89 to 7.44; 4 trials, 782 participants), serious adverse events (RR 0.96, 95% CI 0.88 to 1.05; 4 trials, 782 participants), postoperative transfusion (RR 1.04, 95% CI 0.77 to 1.40; 5 trials, 864 participants), reoperation (RR 2.92, 95% CI 0.58 to 14.61; 2 trials, 612 participants), or postoperative bile leak (RR 1.00, 95% CI 0.67 to 1.48; 4 trials, 782 participants), as the certainty of evidence was very low for all these outcomes. Fibrin-based haemostatic agents versus non-fibrin-based haemostatic agents Sixteen trials (1944 participants) compared FBHAs with non-FBHAs. All trials had at least one domain at high or unclear risk of bias. Twelve trials were at high risk of bias related to blinding. It is unclear if FBHAs compared with non-FBHAs have an effect on perioperative mortality (RR 1.03, 95% CI 0.62 to 1.72; 11 trials, 1436 participants), postoperative transfusion (RR 0.92, 95% CI 0.68 to 1.25; 7 trials, 599 participants), reoperation (RR 0.48, 95% CI 0.25 to 0.90; 3 trials, 358 participants), or postoperative bile leak (RR 1.15, 95% CI 0.60 to 2.21; 9 trials, 1115 participants), as the certainty of evidence was very low for all these outcomes. FBHAs compared with non-FBHAs may have little or no effect on the risk of serious adverse events (RR 0.99, 95% CI 0.95 to 1.03; 9 trials, 1176 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

The evidence for the outcomes in both comparisons (FBHAs versus no intervention and FBHAs versus non-FBHAs) was of very low certainty (or low certainty in one instance) and cannot justify the routine use of FBHAs to reduce blood loss in adult liver resection. While the meta-analysis showed a reduced risk of reoperation with FBHAs compared with non-FBHAs, the analysis was confounded by the small number of trials reporting the event and the risk of bias in all these trials. Future trials should focus on the use of FBHAs in people undergoing liver resection who are at particularly high risk of bleeding. Investigators should evaluate clinically meaningful and patient-important outcomes and follow the SPIRIT and CONSORT statements.

Early versus late removal of urinary catheter after kidney transplantation

BACKGROUND

The optimal treatment for end-stage kidney disease is kidney transplantation. During the operation, a catheter is introduced into the bladder and remains in place postoperatively to allow the bladder to drain. This decreases tension from the cysto-ureteric anastomosis and promotes healing. Unfortunately, urinary catheters can pose an infection risk to patients as they allow bacteria into the bladder, potentially resulting in a urinary tract infection (UTI). The longer the catheter remains in place, the greater the risk of developing a UTI. There is no consensus approach to the time a catheter should remain in place post-transplant. Furthermore, the different timings of catheter removal are thought to be associated with different incidences of UTI and postoperative complications, such as anastomotic breakdown.

OBJECTIVES

This review aimed to compare patients who had their catheter removed < 5 days post-transplant surgery to those patients who had their catheter removed ≥ 5 days following their kidney transplant. Primary outcome measures between the two groups included: the incidence of symptomatic UTIs, the incidence of asymptomatic bacteriuria and the incidence of major urological complications requiring intervention and treatment.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 April 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs comparing timing of catheter removal post-transplantation were eligible for inclusion. All donor types were included, and all recipients were included regardless of age, demographics or type of urinary catheter used.

DATA COLLECTION AND ANALYSIS

Results from the literature search were screened by two authors to identify if they met our inclusion criteria. We designated removal of a urinary catheter before five days (120 hours) as an 'early removal' and anything later than this as a 'late removal.' The studies were assessed for quality using the risk of bias tool. The primary outcome of interest was the incidence of asymptomatic bacteriuria. Statistical analyses were performed using the random effects model, and results were expressed as relative risk (RR) with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Two studies (197 patients) were included in our analysis. One study comprised a full-text article, and the other was a conference abstract with very limited information. The risk of bias in the included studies was generally either high or unclear. It is uncertain whether early versus late removal of the urinary catheter made any difference to the incidence of asymptomatic bacteriuria (RR 0.89, 95% Cl 0.17 to 4.57; participants = 197; I2 = 88%; very low certainty evidence). Data on other outcomes, such as the incidence of UTI and the incidence of major urological complications, were lacking. Furthermore, the follow-up of patients across the studies was short, with no patients being followed beyond one month.

AUTHORS' CONCLUSIONS

A high-quality, well-designed RCT is required to compare the effectiveness of early catheter removal versus late catheter removal in patients following a kidney transplant. At the present time, there is insufficient evidence to suggest any difference between early and late catheter removal post-transplant, and the studies investigating this were generally of poor quality.

Therapeutic donor hypothermia following brain death to improve the quality of transplanted organs

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

This review aims to examine the benefits and harms of therapeutic donor hypothermia in recipients or organs donated after brain death.

Pharmacological testing of therapeutics using normothermic machine perfusion: A pilot study of 2,4-dinitrophenol delivery to steatotic human livers

INTRODUCTION

Normothermic machine perfusion (NMP) provides a platform for drug-delivery. However, pharmacological considerations for therapeutics delivered during NMP are scarcely reported. We aimed to demonstrate the ability of NMP as a platform for pharmacological testing, using a drug which increases metabolism (2,4-dinitrophenol; DNP) as an example therapeutic.

METHODS

We performed 25 h of NMP on human livers which had been declined for transplant due to steatosis (n = 7). Three livers received a DNP bolus, three were controls, and one received a DNP infusion.

RESULTS

Toxicity studies revealed DNP delivery was safe, without hepatotoxic effects. The liver surface temperature was increased in the DNP group (p = 0.046), but no livers suffered hyperthermia-the mechanism of DNP toxicity in vivo. Pharmacokinetic studies revealed DNP elimination with first-order kinetics and 7.7 h half-life (95% CI = 5.1-15.9 hrs). The clearance of DNP in bile was negligible. As expected, DNP significantly increased oxygen consumption (p = 0.023); this increase was closely correlated with perfusate DNP concentration (r2  = 0.975; p = 0.002) and the effect was lost as DNP was eliminated by the liver. A DNP infusion rate, calculated using our pharmacokinetic data, successfully maintained perfusate DNP concentration.

DISCUSSION

Detailed pharmacological testing can be performed during NMP. Our therapeutic (DNP) is rapidly eliminated by the ex vivo liver, meaning the drug effect of increased metabolism is only transient. This demonstrates the importance of assessing pharmacokinetics when delivering therapeutics during NMP, especially for prolonged perfusion of organs with established roles in drug elimination. Rigorous pharmacological testing is needed to unlock the potential of NMP as a clinical drug-delivery platform.

Surveillance of laboratory exposures to human pathogens and toxins, Canada, 2021

Background

The Laboratory Incident Notification Canada surveillance system monitors laboratory incidents that are mandated to be reported under the Human Pathogens and Toxins Act and the Human Pathogens and Toxins Regulations. This article describes laboratory exposure incidents that occurred in Canada in 2021 and individuals affected in these incidents.

Methods

We extracted all laboratory incidents occurring in licensed Canadian laboratories in 2021 from the Laboratory Incident Notification Canada system and analyzed them using the software R. We calculated the rate of exposure incidents and performed descriptive statistics by sector, root cause, activity, occurrence type and type of pathogen/toxin. Analysis of the education level, route of exposure, sector, role and laboratory experience of the affected persons was also conducted. We conducted seasonality analysis to compare the median monthly occurrence of exposure incidents between 2016 and 2020 to monthly incidents in 2021.

Results

Forty-three exposure incidents involving 72 individuals were reported to Laboratory Incident Notification Canada in 2021. There were two confirmed laboratory-acquired infections and one suspected infection. The annual incident exposure rate was 4.2 incidents per 100 active licenses. Most exposure incidents involved non-Security Sensitive Biological Agents (n=38; 86.4%) and human risk group 2 (RG2) pathogens (n=27; 61.4%), with bacteria (n=20; 45.5%) and viruses (n=16; 36.4%) as the most implicated agent types. Microbiology was the most common activity associated with these incidents (n=18; 41.9%) and most incidents were reported by the academic sector (n=20; 46.5%). Sharps-related (n=12; 22.2%) incidents were the most common, while human interaction (e.g. workload constraints/pressures/demands, human error) (n=29, 28.2%) was the most common root cause. Most affected individuals were exposed through inhalation (n=38; 52.8%) and worked as technicians or technologists (n=51; 70.8%). Seasonality analyses revealed that the number of exposure incidents reported in 2021 were highest in September and May.

Conclusion

The rate of laboratory incidents was slightly lower in 2021 than in 2020. The most common occurrence type was sharps-related while issues with human interaction was the most cited root cause.

O030 Image-analysis algorithm to determine quality of cold perfusion in kidney transplantation

Introduction

Surgeon assessment of visual ‘quality of perfusion’ (QOP) influences kidney discard and predicts transplant outcome. However, this assessment is subjective and bias-prone.

We aimed to design an application utilising a smartphone camera to make this assessment objective and enhance decision making.

Methods

The QOP in photographs of backbench kidneys was graded from 1 (ideal) to 5 (very poor) by three independent surgeons. A training cohort was used to develop an image-analysis algorithm, which was validated in a separate cohort.

Results

Analysing surgeon scores of 174 kidney images revealed that inter-rater agreement was good for kidneys displaying the best (rated 1) and worst (rated 4 or 5) QOP. However, for intermediate scores inter-rater agreement was poor. Inter-rater agreement between surgeons decreased as they graded more images; as surgeons fatigued, their ability to classify images worsened. A training cohort (n=174 kidneys) was used for algorithm development. First, small regions within each image were mapped within the CEILAB colour-space, where well-perfused and poorly perfused areas show clear separation. To generate a score for each kidney these regions are compared with ideally flushed kidney tissue. Testing our algorithm (validation cohort - n=29 kidneys) revealed strong correlation between image-analysis QOP score and surgeon assessment, r=0.789 (0.587–0.899), P&lt;0.001.

Conclusion

Surgeon inter-rater agreement on kidney QOP is low for kidneys with borderline QOP and worsens with fatigue. We provide a QOP score utilising an image-analysis algorithm, which correlates with surgeon scoring. With additional images and training this could provide an objective, numerical, point-of-care assessment of organ quality.

Take-home message

Current visual assessment of transplant organ quality is subjective and bias-prone. This body of work attempts to create a point-of-care image-analysis application to provide an objective numeric organ quality score.

MicroRNA antagonist therapy during normothermic machine perfusion of donor kidneys

Normothermic machine perfusion (NMP) is a novel clinical approach to overcome the limitations of traditional hypothermic organ preservation. NMP can be used to assess and recondition organs prior to transplant and is the subject of clinical trials in solid organ transplantation. In addition, NMP provides an opportunity to deliver therapeutic agents directly to the organ, thus avoiding many limitations associated with systemic treatment of the recipient. We report the delivery of oligonucleotide-based therapy to human kidneys during NMP, in this case to target microRNA function (antagomir). An antagomir targeting mir-24-3p localized to the endothelium and proximal tubular epithelium. Endosomal uptake during NMP conditions facilitated antagomir co-localization with proteins involved in the RNA-induced silencing complex (RISC) and demonstrated engagement of the miRNA target. This pattern of uptake was not seen during cold perfusion. Targeting mir-24-3p action increased expression of genes controlled by this microRNA, including heme oxygenase-1 and sphingosine-1-phosphate receptor 1. The expression of genes not under the control of mir-24-3p was unchanged, indicating specificity of the antagomir effect. In summary, this is the first report of ex vivo gymnotic delivery of oligonucleotide to the human kidney and demonstrates that NMP provides the platform to bind and block detrimental microRNAs in donor kidneys prior to transplantation.

Comparing outcomes in right versus left kidney transplantation: A systematic review and meta-analysis

INTRODUCTION

Transplantation of right kidneys can pose technical challenges due to the short right renal vein. Whether this results in inferior outcomes remains controversial.

METHOD

Healthcare Database Advanced Search (HDAS) was used to identify relevant studies. Two authors independently reviewed each study. Statistical analyses were performed using random effects models and results expressed as HR or relative risk (RR) with 95% confidence intervals. Subgroup analyses were performed in kidneys from deceased donors (DD) and living donors (LD).

RESULTS

A total of 35 studies (257,429 participants) were identified. Both deceased and living donor right kidneys were at increased risk of delayed graft function (DGF; RR = 1.12[1.06-1.18] and RR = 1.33[1.21-1.46] respectively; both p < .0001). In absolute terms, for each 100 kidney pairs of DD kidneys transplanted there are 2.72 (1.67-3.78, p < .00001) excess episodes of DGF in right kidneys. Graft thromboses and graft loss due to technical failure was also significantly more likely in right kidneys, in both DD and LD settings. There was no evidence that laterality alters long term graft survival in LD or DD.

CONCLUSION

Right kidneys have inferior early outcomes, with higher rates of DGF, technical failure and graft thrombosis. However, these differences are small in absolute terms, and long-term graft survival is equivalent.

O3 Ex vivo normothermic machine perfusion facilitates gymnotic delivery of RNA interference therapeutics in donor kidneys

Introduction

Normothermic machine perfusion (NMP) of donor kidneys prior to transplantation provides a platform for delivery of novel therapeutics to optimize organ quality. This includes RNA interference (RNAi) therapeutics e.g. antisense oligonucleotides (ASO) that block detrimental microRNAs. The intracellular kinetics of RNAi therapeutics are crucial for their pharmacological effect, however, it remains poorly understood. NMP provides an ideal platform to investigate this further.

Method

During NMP, human kidneys (n = 12) were treated for 6 hours with a fluorescently-labelled ASO designed to block microRNA-24-3p activity. Biopsies were taken at 0, 2, 4, and 6 hours. Kidney sections were stained with antibodies against early endosomes (Rab5), late endosomes (Rab7), RNA-induced silencing complexes (GW182) and lysosomes (LAMP2). Confocal microscopy images were obtained and co-localisation quantified using Hugyens™ software following batch deconvolution. The global transcriptomic impact of ASO therapy was also assessed using RNA sequencing.

Result

Following 2 hours of NMP, ASO was primarily found in tubular epithelial cells. Co-localisation studies revealed ASO uptake via endocytosis and endosomal sorting occurring during NMP. This was followed by cytoplasmic escape and co-localisation of ASO with GW182 proteins. This pattern of co-localisation was not seen in scrambled sequence or cold perfusion controls. RNAseq analysis revealed a decrease in inflammatory pathways and upregulation of microRNA-24-3p targets.

Discussion

This is the first study to demonstrate NMP facilitates gymnotic ASO delivery directly into the RISC, whereby, it blocks microRNA-mediated mRNA silencing and increases bioavailability of protective targets. This study highlights the capacity of NMP to re-programme gene expression in donor kidneys using RNAi therapeutics.

Take-home Message

Ex vivo normothermic machine perfusion of donor kidneys provides a unique window of opportunity prior to transplantation when we can deliver therapies to improve the quality of the organ. Novel genetic therapies designed to protect kidneys against ischemia reperfusion injury could potentially increase organ utilisation and improve post-transplant outcomes for the many patients on the kidney transplant waiting list.

O6: EARLY ANASTOMOTIC BILIARY COMPLICATIONS AFTER LIVER TRANSPLANTATION

Introduction

Biliary leaks and anastomotic strictures are common early biliary complications (EBC) following liver transplantation. However, their impact on outcomes remains controversial and poorly described.

Method

The NHS registry on adult liver transplantation between 2006 and 2017 was retrospectively reviewed (n=8304). Multiple imputations were performed to account for missing data. Adjusted regression models were used to assess predictors of EBC, and their impact on outcomes. 35 potential variables were included, and backwards stepwise selection enabled unbiased selection of variables for inclusion in final models.

Result

EBC occurred in 9.6% of patients. Adjusted cox regression revealed that EBCs have a significant and independent impact on graft survival (Leak HR=1.325; P=0.021, Stricture HR=1.514; P=0.002, Leak plus stricture HR=1.533; P=0.034) and patient survival (Leak HR=1.218; P=0.131, Stricture HR=1.578; P&lt;0.001, Leak plus stricture HR=1.507; P=0.044). Patients with EBC had longer median hospital stay (23 versus 15 days; P&lt;0.001) and increased chance for readmission within the first year (56% versus 32%; P&lt;0.001). On adjusted logistic regression the following were identified as independent risk factors for development of EBC: donation following circulatory death (OR=1.280; P=0.009), accessory hepatic artery (OR=1.324; P=0.005), vascular anastomosis time in minutes (OR=1.005; P=0.032) and ethnicity ‘other’ (OR=1.838; P=0.011).

Conclusion

EBCs prolong hospital stay, increase readmission rates and are independent risk factors for diminished graft survival and increased mortality in liver transplantation. We have identified factors that increase the likelihood of EBC occurrence; further research into interventions to prevent EBCs in these at-risk groups is vital to improve liver transplantation outcomes.

Take-home message

Using a large registry database we have shown that early anastomotic biliary complications are independent risk factors for decreased graft survival and increased mortality after liver transplantation. Research into interventions to prevent biliary complications in high risk groups are essential to improve liver transplant outcomes.

Risk factors and impact of early anastomotic biliary complications after liver transplantation: UK registry analysis

Background

Biliary leaks and anastomotic strictures are common early anastomotic biliary complications (EABCs) following liver transplantation. However, there are no large multicentre studies investigating their clinical impact or risk factors. This study aimed to define the incidence, risk factors and impact of EABC.

Methods

The NHS registry on adult liver transplantation between 2006 and 2017 was reviewed retrospectively. Adjusted regression models were used to assess predictors of EABC, and their impact on outcomes.

Results

Analyses included 8304 liver transplant recipients. Patients with EABC (9·6 per cent) had prolonged hospitalization (23 versus 15 days; P < 0·001) and increased chance for readmission within the first year (56 versus 32 per cent; P < 0·001). Patients with EABC had decreased estimated 5-year graft survival of 75·1 versus 84·5 per cent in those without EABC, and decreased 5-year patient survival of 76·9 versus 83·3 per cent; both P < 0.001. Adjusted Cox regression revealed that EABCs have a significant and independent impact on graft survival (leak hazard ratio (HR) 1·344, P = 0·015; stricture HR 1·513, P = 0·002; leak plus stricture HR 1·526, P = 0·036) and patient survival (leak HR 1·215, P = 0·136, stricture HR 1·526, P = 0·001; leak plus stricture HR 1·509; P = 0·043). On adjusted logistic regression, risk factors for EABC included donation after circulatory death grafts, graft aberrant arterial anatomy, biliary anastomosis type, vascular anastomosis time and recipient model of end-stage liver disease.

Conclusion

EABCs prolong hospital stay, increase readmission rates and are independent risk factors for graft loss and increased mortality. This study has identified factors that increase the likelihood of EABC occurrence; research into interventions to prevent EABCs in these at-risk groups is vital to improve liver transplantation outcomes.

Novel delivery of cellular therapy to reduce ischemia reperfusion injury in kidney transplantation

Ex vivo normothermic machine perfusion (NMP) of donor kidneys prior to transplantation provides a platform for direct delivery of cellular therapeutics to optimize organ quality prior to transplantation. Multipotent Adult Progenitor Cells (MAPC^® ) possess potent immunomodulatory properties that could minimize ischemia reperfusion injury. We investigated the potential capability of MAPC cells in kidney NMP. Pairs (5) of human kidneys, from the same donor, were simultaneously perfused for 7 hours. Kidneys were randomly allocated to receive MAPC treatment or control. Serial samples of perfusate, urine, and tissue biopsies were taken for comparison. MAPC-treated kidneys demonstrated improved urine output (P = .009), decreased expression of injury biomarker NGAL (P = .012), improved microvascular perfusion on contrast-enhanced ultrasound (cortex P = .019, medulla P = .001), downregulation of interleukin (IL)-1β (P = .050), and upregulation of IL-10 (P < .047) and Indolamine-2, 3-dioxygenase (P = .050). A chemotaxis model demonstrated decreased neutrophil recruitment when stimulated with perfusate from MAPC-treated kidneys (P < .001). Immunofluorescence revealed prelabeled MAPC cells in the perivascular space of kidneys during NMP. We report the first successful delivery of cellular therapy to a human kidney during NMP. Kidneys treated with MAPC cells demonstrate improvement in clinically relevant parameters and injury biomarkers. This novel method of cell therapy delivery provides an exciting opportunity to recondition organs prior to transplantation.

Interventions for preventing thrombosis in solid organ transplant recipients

BACKGROUND

Graft thrombosis is a well-recognised complication of solid organ transplantation and is one of the leading causes of graft failure. Currently there are no standardised protocols for thromboprophylaxis. Many transplant units use unfractionated heparin (UFH) and fractionated heparins (low molecular weight heparin; LMWH) as prophylaxis for thrombosis. Antiplatelet agents such as aspirin are routinely used as prophylaxis of other thrombotic conditions and may have a role in preventing graft thrombosis. However, any pharmacological thromboprophylaxis comes with the theoretical risk of increasing the risk of major blood loss following transplant. This review looks at benefits and harms of thromboprophylaxis in patients undergoing solid organ transplantation.

OBJECTIVES

To assess the benefits and harms of instituting thromboprophylaxis to patients undergoing solid organ transplantation.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 10 November 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs designed to examine interventions to prevent thrombosis in solid organ transplant recipients. All donor types were included (donor after circulatory (DCD) and brainstem death (DBD) and live transplantation). There was no upper age limit for recipients in our search.

DATA COLLECTION AND ANALYSIS

The results of the literature search were screened and data collected by two independent authors. Dichotomous outcome results were expressed as risk ratio (RR) with 95% confidence intervals (CI). Random effects models were used for data analysis. Risk of bias was independently assessed by two authors using the risk of bias assessment tool. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We identified nine studies (712 participants). Seven studies (544 participants) included kidney transplant recipients, and studies included liver transplant recipients. We did not identify any study enrolling heart, lung, pancreas, bowel, or any other solid organ transplant recipient. Selection bias was high or unclear in eight of the nine studies; five studies were at high risk of bias for performance and/or detection bias; while attrition and reporting biases were in general low or unclear. Three studies (180 participants) primarily investigated heparinisation in kidney transplantation. Only two studies reported on graft vessel thrombosis in kidney transplantation (144 participants). These small studies were at high risk of bias in several domains and reported only two graft thromboses between them; it therefore remains unclear whether heparin decreases the risk of early graft thrombosis or non-graft thrombosis (very low certainty). UFH may make little or no difference versus placebo to the rate of major bleeding events in kidney transplantation (3 studies, 155 participants: RR 2.92, 95% CI 0.89 to 9.56; I² = 0%; low certainty evidence). Sensitivity analysis using a fixed-effect model suggested that UFH may increase the risk of haemorrhagic events compared to placebo (RR 3.33, 95% CI 1.04 to 10.67, P = 0.04). Compared to control, any heparin (including LMWH) may make little or no difference to the number of major bleeding events (3 studies, 180 participants: RR 2.70, 95% CI 0.89 to 8.19; I² = 0%; low certainty evidence) and had an unclear effect on risk of readmission to intensive care (3 studies, 180 participants: RR 0.68, 95% CI 0.12 to 3.90, I² = 45%; very low certainty evidence). The effect of heparin on our other outcomes (including death, patient and graft survival, transfusion requirements) remains unclear (very low certainty evidence). Three studies (144 participants) investigated antiplatelet interventions in kidney transplantation: aspirin versus dipyridamole (1), and Lipo-PGE₁ plus low-dose heparin to "control" in patients who had a diagnosis of acute rejection (2). None of these reported on early graft thromboses. The effect of aspirin, dipyridamole and Lipo PGE₁ plus low-dose heparin on any outcomes is unclear (very low certainty evidence). Two studies (168 participants) assessed interventions in liver transplants. One compared warfarin versus aspirin in patients with pre-existing portal vein thrombosis and the other investigated plasmapheresis plus anticoagulation. Both studies were abstract-only publications, had high risk of bias in several domains, and no outcomes could be meta-analysed. Overall, the effect of any of these interventions on any of our outcomes remains unclear with no evidence to guide anti-thrombotic therapy in standard liver transplant recipients (very low certainty evidence).

AUTHORS' CONCLUSIONS

Overall, there is a paucity of research in the field of graft thrombosis prevention. Due to a lack of high quality evidence, it remains unclear whether any therapy is able to reduce the rate of early graft thrombosis in any type of solid organ transplant. UFH may increase the risk of major bleeding in kidney transplant recipients, however this is based on low certainty evidence. There is no evidence from RCTs to guide anti-thrombotic strategies in liver, heart, lung, or other solid organ transplants. Further studies are required in comparing anticoagulants, antiplatelets to placebo in solid organ transplantation. These should focus on outcomes such as early graft thrombosis, major haemorrhagic complications, return to theatre, and patient/graft survival.

Methaemoglobinaemia Can Complicate Normothermic Machine Perfusion of Human Livers

Background: Although liver normothermic machine perfusion is increasingly used clinically, there are few reports of complications or adverse events. Many centers perform liver NMP to viability test suboptimal grafts, often for prolonged periods. In addition, several researchers are investigating NMP as a drug delivery platform, which usually necessitates prolonged perfusion of otherwise non-viable liver grafts. We describe two instances of methaemoglobinaemia during NMP of suboptimal livers.

Methods: The NMP of eight human livers rejected for transplantation is described. Methaemoglobinaeima developed in two; one perfused using generic Medtronic™ perfusion equipment and one using the OrganOx Metra®.

Results: The first liver (53 years DBD) developed methaemoglobinaemia (metHb = 2.4%) after 13 h of NMP, increasing to metHb = 19% at 16 h. Another liver (45 years DBD) developed methaemoglobinaemia at 25 h (metHb = 2.8%), which increased to metHb = 28.2% at 38 h. Development of methaemoglobinaemia was associated with large reductions in oxygen delivery and oxygen extraction. Both livers were steatotic and showed several suboptimal features on viability testing. Delivery of methylene blue failed to reverse the methaemoglobinaemia. Compared to a matched cohort of steatotic organs, livers which developed methaemoglobinaemia showed significantly higher levels of hemolysis at 12 h (prior to development of methaemoglobinaemia).

Conclusions: Methaemglobinaemia is a complication of NMP of suboptimal liver grafts, not limited to a single machine or perfusion protocol. It can occur within 13 h (a timepoint frequently surpassed when NMP is used clinically) and renders further perfusion futile. Therefore, metHb should be monitored during NMP visually and using blood gas analysis.

Cell therapy during machine perfusion

There has been increasing use of organs from extended criteria or donation after circulatory death donors to meet the demands of the transplant waiting list. Over the past decade, there has been considerable progress in technologies to preserve organs prior to transplantation to improve the function of these marginal organs. This has led to the development of normothermic machine perfusion, whereby an organ is perfused with warmed, oxygenated blood and nutrients to resume normal physiological function in an isolated ex-vivo platform. With this advance in preservation comes significant opportunities to recondition, repair and regenerate organs prior to transplantation using cellular therapies. This review aims to discuss the possibilities of machine perfusion technology; highlighting the potential for organ-directed reconditioning and the future avenues for investigation in this field.

Hypothermic machine perfusion is superior to static cold storage in deceased donor kidney transplantation: A meta-analysis

BACKGROUND

There remains a lack of consensus on the optimal storage method for deceased donor kidneys. This meta-analysis compares storage with hypothermic machine perfusion (HMP) vs traditional static cold storage (SCS).

METHODS

The Cochrane Kidney and Transplant Specialised Register was searched to identify (quasi-) randomized controlled trials (RCTs) to include in our meta-analysis. PRISMA guidelines were used to perform and write this review.

RESULTS

There is high-certainty evidence that HMP reduces the risk of delayed graft function (DGF) when compared to SCS (2138 participants from 14 studies, RR = 0.77; 0.67-0.90, P = .0006). This benefit is significant in both donation following circulatory death (DCD; 772 patients from seven studies, RR = 0.75; 0.64-0.87, P = .0002) and donation following brainstem death (DBD) grafts (971 patients from four studies, RR = 0.78; 0.65-0.93, P = .006). The number of perfusions required to prevent one episode of DGF was 7.26 and 13.60 in DCD and DBD grafts, respectively. There is strong evidence that HMP also improves graft survival in both DBD and DCD grafts, at both 1 and 3 years. Economic analyses suggest HMP is cost-saving at 1 year compared with SCS.

CONCLUSION

Hypothermic machine perfusion is superior to SCS in deceased donor renal transplantation. Direct comparisons with normothermic machine perfusion in RCTs are essential to identify optimal preservation methods in kidney transplantation.

Early versus late ureteric stent removal after kidney transplantation

BACKGROUND

Kidney transplantation is the treatment of choice for patients with end-stage kidney disease. In a previous review we concluded that the routine use of ureteric stents in kidney transplantation reduces the incidence of major urological complications (MUC). Unfortunately, this reduction appears to lead to a concomitant rise in urinary tract infections (UTI). For kidney recipients UTI is now the commonest post-transplant complication. This represents a considerable risk to the immunosuppressed transplant recipient, particularly in the era of increased immunologically challenging transplants. There are a number of different approaches taken when considering ureteric stenting and these are associated with differing degrees of morbidity and hospital cost.

OBJECTIVES

This review aimed to look at the benefits and harms of early versus late removal of the ureteric stent in kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 27 March 2017 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All RCTs and quasi-RCTs were included in our meta-analysis. We included recipients of kidney transplants regardless of demography (adults or children) or the type of stent used.

DATA COLLECTION AND ANALYSIS

Two authors reviewed the identified studies to ascertain if they met inclusion criteria. We designated removal of a ureteric stent before the third postoperative week (< day 15) or during the index transplant admission as "early" removal. The studies were assessed for quality using the risk of bias tool. The primary outcome of interest was the incidence of MUC. Further outcomes of interest were the incidence of UTI, idiosyncratic stent-related complications, hospital-related costs and adverse events. A subgroup analysis was performed examining the difference in complications reported depending on the type of ureteric stent used; bladder indwelling (BI) versus per-urethral (PU). Statistical analyses were performed using the random effects model and results expressed as relative risk (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Five studies (1127 patients) were included in our analysis. Generally the risk of bias of the included studies was judged low or unclear; they addressed the research question and utilised a prospective randomised design. It is uncertain whether early stent removal verus late stent removal improved the incidence of MUC (5 studies, 1127 participants: RR 1.87, 95% CI 0.61 to 5.71; I² = 21%; low certainty evidence). The incidence of UTI may be reduced in the early stent removal group (5 studies, 1127 participants: RR 0.49 95% CI 0.30 to 0.81; I² = 59%; moderate certainty evidence). This possible reduction in the UTI incidence was only apparent if a BI stent was used, (3 studies, 539 participants, RR 0.45 95% CI 0.29 to 0.70; I² = 13%; moderate certainty evidence). However, if an externalised PU stent was used there was no discernible difference in UTI incidence between the early and late group (2 studies, 588 participants: RR 0.60 95% CI 0.17, 2.03; I² = 83%; low certainty evidence). Data on health economics and quality of life outcomes were lacking.

AUTHORS' CONCLUSIONS

Early removal of ureteric stents following kidney transplantation may reduce the incidence of UTI while it uncertain if there is a higher risk of MUC. BI stents are the optimum method for achieving this benefit.

Abstract P2-09-02: Panel testing for familial breast cancer: Tension at the boundary of research and clinical care

Gene panel sequencing is revolutionizing germline risk assessment for hereditary breast cancer. Despite scant evidence supporting the role of many of these genes in breast cancer predisposition, results are often reported to families as the definitive explanation for their family history. We assessed the frequency of mutations in 18 genes commonly included in hereditary breast cancer panels among 2,000 index cases from breast cancer families and 1,997 population controls. Cases were predominantly breast cancer-affected women referred to specialized familial cancer centers (BRCA1 and BRCA2 wild-type). Controls were cancer-free women from the LifePool study (www.lifepool.org). Sequencing data were filtered for known pathogenic or novel loss of function mutations.

The frequency of pathogenic mutations in BRCA1 and BRCA2 in the control group was 0.2% (4 mutations) and 0.4% (8 mutations), respectively, which is consistent with previous indirect estimates for Caucasian populations but to our knowledge this the largest direct assessment of their prevalence.

Excluding 18 mutations identified in BRCA1 and BRCA2 among the cases and controls, a total of 69 cases (3.5%) and 26 controls (1.3%) were found to carry an "actionable mutation". PALB2 was most frequently mutated (22 cases, 3 controls), while no mutations were identified in PTEN or STK11. Among the remaining genes, loss of function mutations were rare with similar frequency between cases and controls.

The frequency of mutations in most breast cancer panel genes among individuals selected for possible hereditary breast cancer is low and in many cases similar or even lower than that observed among cancer-free population controls. While multi-gene panels can significantly aid in cancer risk management, they equally have the potential to provide clinical misinformation and harm at the individual level if the data is not interpreted cautiously.

Citation Format: Campbell IG, Thompson ER, Rowely SM, Li N, McInerny S, Devereux L, Wong-Brown MW, Trainer AH, Mitchell G, Scott RJ, James PA. Panel testing for familial breast cancer: Tension at the boundary of research and clinical care. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-02.

Aircraft gas turbine materials and processes

Materials and processing innovations that have been incorporated into the manufacture of critical components for high-performance aircraft gas turbine engines are described. The materials of interest are the nickel- and cobalt-base superalloys for turbine and burner sections of the engine, and titanium alloys and composites for compressor and fan sections of the engine. Advanced processing methods considered include directional solidification, hot isostatic pressing, superplastic foring, directional recrystallization, and diffusion brazing. Future trends in gas turbine technology are discussed in terms of materials availability, substitution, and further advances in air-cooled hardware.

Moral hypocrisy: appearing moral to oneself without being so

How can people appear moral to themselves when they fail to act morally? Two self-deception strategies were considered: (a) misperceive one's behavior as moral and (b) avoid comparing one's behavior with moral standards. In Studies 1 and 2 the authors documented the importance of the 2nd strategy but not the 1st. Among participants who flipped a coin to assign themselves and another participant "fairly" to tasks, even a clearly labeled coin that prevented misperception did not produce a fair result (Study 1). Inducing behavior-standard comparison through self-awareness did (Study 2). Study 3 qualified the self-awareness effect: When moral standards were not salient before acting, self-awareness no longer increased alignment of behavior with standards. Instead, it increased alignment of standards with behavior and produced less moral action. Overall, results showed 3 different faces of moral hypocrisy.

Moral hypocrisy: appearing moral to oneself without being so

How can people appear moral to themselves when they fail to act morally? Two self-deception strategies were considered: (a) misperceive one's behavior as moral and (b) avoid comparing one's behavior with moral standards. In Studies 1 and 2 the authors documented the importance of the 2nd strategy but not the 1st. Among participants who flipped a coin to assign themselves and another participant "fairly" to tasks, even a clearly labeled coin that prevented misperception did not produce a fair result (Study 1). Inducing behavior-standard comparison through self-awareness did (Study 2). Study 3 qualified the self-awareness effect: When moral standards were not salient before acting, self-awareness no longer increased alignment of behavior with standards. Instead, it increased alignment of standards with behavior and produced less moral action. Overall, results showed 3 different faces of moral hypocrisy.

Increases in number and size of osteoclasts in response to calcium or phosphorus deficiency in the rat

In this study, the two determinants of the rate of osteoclastic bone resorption, cell number and cell activity, were evaluated to characterize the response to two chronic resorptive stimuli, a calcium-deficient diet and a phosphorus-deficient diet, fed to rats for 8 days. The number of osteoclast nuclei was determined directly and the resorptive activity of osteoclasts indirectly from cell size. In our sampling site in the tibial diaphysis, there were marked increases in osteoclast layer width (i.e., cell size) and in the number of osteoclasts and osteoclast nuclei in both test groups. Also, in both test groups the increase in the number of osteoclast nuclei was greater than the increase in osteoclast width, emphasizing the importance of osteoclast stem cell activity in the resorptive response. When the data on the control and test animals were pooled, there was a strong correlation between the width of the osteoclast layer and the number of osteoclast nuclei (r = 0.87, P less than 0.001). Thus, these two resoprtive stimuli produced proportional changes in osteoclast cell number and probably activity, raising the possibility that the resorptive response is sterotyped. These results also suggest the existence of a control mechanism which coupled the proliferative activity of osteoclast stem cells and the resorptive activity of osteoclasts. Despite the fact that the rats were subjected to chronic resorptive stimuli, forming surface and the total number of osteoblasts were also increased. Moreover, in data pooled from control and test rats, there was a strong correlation between the number of osteoclast nuclei and the number of osteoblasts (r = 0.92, P less than 0.001). This implies that chronic resorptive stimuli directly or indirectly stimulate osteogenic stem cells to increase production of osteoblasts as well as osteoclasts. The observed coupling of differentiated cell number probably contributes to the established phenomenon of coupling between the rates of bone accretion and resorption.