Asystolic donor warm ischemia time is associated with development of postreperfusion syndrome in donation after circulatory death liver transplant.

BACKGROUND: Individual events during donation after circulatory death (DCD) procurement, such as hypotensive or hypoxic warm ischemia, or circulatory arrest are all a part of donor warm ischemia time (dWIT), and may have differing effects on the outcome of the liver graft. This study aimed to identify risk factors for postreperfusion syndrome (PRS), a state of severe hemodynamic derangement following graft reperfusion, and its impact on DCD liver transplantation (LT) outcomes. METHODS: This was a retrospective analysis using 106 DCD LT. Detailed information for events during procurement (withdrawal of life support; systolic blood pressure < 80 mmHg; oxygen saturation < 80%; circulatory arrest; aortic cold perfusion) and their association with the development of PRS were examined using logistic regression. RESULTS: The overall incidence of PRS was 26.4%, occurring in 28 patients. Independent risk factors for PRS were asystolic dWIT (odds ratio (OR) 3.65, 95% confidence interval (CI) 1.38-9.66) and MELD score (OR 1.06, 95% CI 1.01-1.10). Total bilirubin was significantly higher in the PRS group at postoperative day (POD) 1 (p = .02; 5.2 mg/dL vs. 3.4 mg/dL), POD 3 (p = .049; 4.5 mg/dL vs. 2.8 mg/dL), and POD 7 (p = .04; 3.1 mg/dL vs. 1.9 mg/dL). Renal replacement therapy after LT was more likely to be required in the PRS group (p = .01; 48.2% vs. 23.1%). CONCLUSION: Asystolic dWIT is a risk factor for the development of PRS in DCD LT. Our results suggest that asystolic dWIT should be considered when selecting DCD liver donors.

The learning curve of liver procurement from donation after circulatory death donor.

PURPOSE: This study aimed to evaluate the learning curve for donation after circulatory death (DCD) liver procurement. METHODS: DCD liver procurements performed by a single surgeon (n = 36) were separated into two phases: the learning and established phases. RESULTS: A cumulative sum analysis using the operative donor warm ischemia time (oWIT) and donor hepatectomy time (dHT) showed that ten and seven cases, respectively, were needed for stable surgical procedures. The established phase (n = 26, since Case 11) was likely to have a shorter oWIT (p = 0.06; 7.5 min vs. 9 min) and dHT (p = 0.09; 32 min vs. 37 min) than the learning phase. While the hospital stay was significantly shorter and donor age was older in the established phase (p = 0.04 and p < 0.01; 12 days vs. 41 days and 38 years vs. 24 years, respectively), the incidence rates of post-transplant complications such as early allograft dysfunction (p = 0.74) and vascular complications (p = 0.53) were similar. CONCLUSIONS: The learning curve for DCD liver procurement demonstrated that 10 cases were required to establish these techniques. The oWIT and dHT for DCD liver procurement can represent markers of operative efficiency.

Decreased Utilization Rate of Grafts for Liver Transplantation After Implementation of Acuity Circle-based Allocation.

BACKGROUND: The allocation system for livers began using acuity circles (AC) in 2020. In this study, we sought to evaluate the impact of AC policy on the utilization rate for liver transplantation (LT). METHODS: Using the US national registry data between 2018 and 2022, LTs were equally divided into 2 eras: pre-AC (before February 4, 2020) and post-AC (February 4, 2020, and after). Deceased potential liver donors were defined as deceased donors from whom at least 1 organ was procured. RESULTS: The annual number of deceased potential liver donors increased post-AC (from 10 423 to 12 259), approaching equal to that of new waitlist registrations for LT (n = 12 801). Although the discard risk index of liver grafts was comparable between the pre- and post-AC eras, liver utilization rates in donation after brain death (DBD) and donation after circulatory death (DCD) donors were lower post-AC ( P < 0.01; 79.8% versus 83.4% and 23.7% versus 26.0%, respectively). Recipient factors, ie, no recipient located, recipient determined unsuitable, or time constraints, were more likely to be reasons for nonutilization after implementation of the AC allocation system compared to the pre-AC era (20.0% versus 12.3% for DBD donors and 50.1% versus 40.8% for DCD donors). Among non-high-volume centers, centers with lower utilization of marginal DBD donors or DCD donors were more likely to decrease LT volume post-AC. CONCLUSIONS: Although the number of deceased potential liver donors has increased, overall liver utilization among deceased donors has decreased in the post-AC era. To maximize the donor pool for LT, future efforts should target specific reasons for liver nonutilization.

Normothermic Regional Perfusion Can Improve Both Utilization and Outcomes in DCD Liver, Kidney, and Pancreas Transplantation.

Normothermic regional perfusion (NRP) has gained widespread adoption in multiple European countries. The aim of this study was to examine the influence of thoracoabdominal-NRP (TA-NRP) on the utilization and outcomes of liver, kidney, and pancreas transplantation in the United States. Methods: Using the US national registry data between 2020 and 2021, donation after circulatory death (DCD) donors were separated into 2 groups: DCD with TA-NRP and without TA-NRP. There were 5234 DCD donors; among them 34 donors were with TA-NRP. After 1:4 propensity score matching, the utilization rates were compared between DCD with and without TA-NRP. Results: Although the utilization rates of kidney and pancreas were comparable (P = 0.71 and P = 0.06, 94.1% versus 95.6% and 8.8% versus 2.2%, respectively), that of liver in DCD with TA-NRP was significantly higher (P < 0.001; 70.6% versus 39.0%). Among 24 liver transplantations, 62 kidney transplantations, and 3 pancreas transplantations from DCD with TA-NRP, there were 2 liver grafts and 1 kidney graft that failed within 1 y after transplantation. Conclusions: TA-NRP in the United States significantly increased the utilization rate of abdominal organs from DCD donors with comparable outcomes after transplantation. Increasing use of NRP may expand the donor pool without compromising transplant outcomes.

The impact of geographic location versus center practice on center volume in liver transplantation after the acuity circle policy.

BACKGROUND: The allocation system for livers used the acuity circles (AC) beginning in 2020. In this study, we sought to evaluate the effect of the AC policy on center transplant volumes, from geographic and center practice perspectives. METHODS: Using the US national registry data between 2018 and 2022, adult liver transplantations (LTs) were separated into two eras: before AC and after AC. RESULTS: The number of LT for Model for End-Stage Liver Disease (MELD) scores ≥29 have significantly increased by 10%, and waitlist times for those patients have been significantly shorter after AC. These benefits were not found in patients with MELD scores <29. The geographic distribution of transplant centers reveals that the majority of centers which increased their transplant volume (18 out of 25 centers) are located in high-population states while there are seven transplant centers in nonhigh-population states. The centers in the nonhigh-population states utilized more marginal donation after brain death (DBD) and donation after circulatory death (DCD) donors by 27% and 155%, respectively. MELD scores were significantly lower in the nonhigh-population states compared with those in the high-population states (p < .01). CONCLUSION: AC improved the LT access for patients with MELD scores ≥29, which benefited the high-population states. However, aggressive center practices to utilize marginal DBD and DCD donors were able to increase transplant volume and lower median allocation MELD scores.

DCD Hepatitis C Virus-positive Donor Livers Can Achieve Favorable Outcomes With Liver Transplantation and Are Underutilized.

BACKGROUND: Hepatitis C virus (HCV)-positive donors (antibody-positive [Ab + ] or nucleic acid test positive [NAT + ] donors) have been underutilized. The aim of this study was to evaluate the utilization of livers from HCV-positive with donation after circulatory death (DCD) and to assess outcomes in recipients of these grafts. METHODS: Data between 2015 and 2019 were obtained from the United Network for Organ Sharing database. The utilization rates and graft survival among 8455 DCD liver and nonliver donors and 2278 adult DCD liver transplantation (LT) recipients were reviewed on the basis of donor HCV Ab/NAT status. RESULTS: The utilization of Ab + /NAT - donors <40 y and Ab + /NAT + donors ≥40 y was low than utilization of HCV-negative donors ( P < 0.001). Multivariate analysis identified HCV status (odds ratio [OR], 1.62; 95% confidence interval [CI], 1.06-2.48 in Ab + /NAT - , and OR, 1.49; 95% CI, 1.09-2.05 in Ab + /NAT + ) as an independent predictor of nonutilization of liver grafts. The rate of significant liver fibrosis was comparable in Ab + /NAT - (3.5%; P = 0.84) but was higher in Ab + /NAT + (8.7%; P = 0.03) than that in Ab - /NAT - donors. Kaplan-Meier survival curves demonstrated comparable 3-y patient survival in recipients of HCV-positive grafts compared with recipients of HCV-negative grafts ( P = 0.63; 85.6% in Ab - /NAT - , 80.4% in Ab + /NAT - , and 88.7% in Ab + /NAT + ). CONCLUSIONS: Patient and graft survival rates are similar between HCV-positive and HCV-negative DCD LT. However, HCV-positive donors are particularly underutilized for DCD LT.

"We can work it out": positive problem solving as a mediator between perspective-taking and relationship satisfaction among college students.

Objective: The present study aimed to examine the role of positive problem solving in the relation between perspective taking and relationship satisfaction.Participants: One hundred and four college students participated in the present study, if they had been in a romantic relationship for a minimum of six months.Methods: Participants completed measures of relationship satisfaction, perspective-taking relative to romantic couples, and of positive problem-solving in couples.Results: As predicted, both perspective-taking and positive problem-solving were significantly related to relationship satisfaction. In addition, positive problem-solving emerged as a significant partial mediator of the relation between perspective-taking and relationship satisfaction.Conclusions: The benefits of skills training in the areas of perspective-taking and problem-solving in college student health and functioning are discussed.

The Implication of Center Volumes in Donation After Circulatory Death for Liver Transplantation: Donor-Recipient Selection and Outcomes.

BACKGROUND: The use of donation after circulatory death liver transplant (DCD LT) has increased and the outcomes have improved. There are little data concerning the details of centers' practice. METHODS: Using the United Network for Organ Sharing Standard Transplant Analysis and Research data, the centers were stratified into 4 quartiles: lowest-, low-, high-, and highest-volume quartiles. RESULTS: High-risk donors, defined as older donors (≥50 years) or obese donors (body mass index ≥ 30 kg/m2), linearly increased in line with the centers' volumes (P < .001), while cold ischemia time (CIT) showed an inverse correlation (P < .001). High-risk recipients, defined as those with high Model for End-stage Liver Disease score, re-LT, inpatient, or ventilator/dialysis before LT, did not show any significant difference (P = .74) except in the highest-volume quartile (P < .001). One-year graft survival showed a bimodal pattern across the 4 quartiles (P = .027): superior graft survival in the highest-volume quartile and in the low-volume quartile and inferior graft survival in the high-volume quartile and in the lowest-volume quartile. CONCLUSIONS: High-risk donors can achieve satisfactory outcomes by being matched with low-risk recipients and shortening CIT. However, high-risk recipients may not result in favorable outcomes with DCD LT even with centers' experience and shorter CIT.

Varying Utilization Rates but Superior Outcomes in Liver Transplantation From Hepatitis C-positive Donors in the United States: An Analysis of the OPTN/UNOS Database.

BACKGROUND: Liver transplantation (LT) from hepatitis C virus (HCV)-positive donors [antibody positive (Ab+) or nucleic acid test-positive (NAT+) donors] has been reported to achieve successful outcomes. However, donor and recipient selection has not been well-characterized. METHODS: Data between 2015 and 2019 were obtained from the United Network for Organ Sharing database. The utilization rates and graft survival among 35 239 potential donors and 23 780 adult LT recipients were reviewed based on donor HCV Ab/NAT status. RESULTS: The utilization of Ab+/NAT+ donors was significantly reduced compared with HCV-negative donors (66.4% versus 80.0%, P < 0.001) among donors aged between 40 and 69 y. Recipients of livers from HCV-positive donors had lower laboratory and allocation Model for End-stage Liver Disease scores (both P < 0.001). HCV-positive donors were younger ( P < 0.001). Kaplan-Meyer survival curves demonstrated significantly superior 1-y graft survival in recipients of HCV-positive grafts compared with those from HCV-negative grafts ( P = 0.004; 97.1% in Ab-/NAT+, 93.9% in Ab+/NAT-, and 93.7% in Ab+/NAT+ versus 91.8% in Ab-/NAT-). Multivariate analysis for 1-y graft survival identified donor age [hazard ratio (HR) = 1.01; 95% confidence interval (CI), 1.00-1.01] and laboratory Model for End-stage Liver Disease score (HR = 1.01; 95% CI, 1.00-1.01) as independent predictors but not donor HCV status: HR 0.77' 95% CI, 0.58-1.02 in Ab+/NAT-; HR 0.82' 95% CI, 0.66-1.03 in Ab+/NAT+; and HR 0.39' 95% CI, 0.10-1.55 in Ab-/NAT+. CONCLUSIONS: More widespread utilization of HCV-positive donors, especially Ab+/NAT+ donors of age 40-69 y, may expand the donor pool without impairing short-term outcomes after LT.

Postreperfusion syndrome in liver transplantation: Outcomes, predictors, and application for recipient selection.

BACKGROUND: This study aimed to identify risk factors for postreperfusion syndrome (PRS) and its impact on LT outcomes. METHODS: Data analysis was performed in 1021 adult patients undergoing donation after brain death (DBD) LT to identify PRS incidence, the risk factors for PRS development, and its impact on LT outcomes. RESULTS: The overall incidence of PRS was 16.1%. Independent risk factors for PRS included donor age (odds ratio (OR) 1.01, P = .02), donor body mass index (BMI) (OR 1.04, P = .003), moderate macrosteatosis (OR 2.48, P = .02), and cold ischemia time (CIT) (OR 1.06, P = .02). On multivariable analysis for 30-day graft failure, PRS (hazard ratio (HR) 3.49; P < .001) and Model for End-stage Liver Disease (MELD) score (HR 1.01; P = .05) were independent risk factors. Patients were categorized into four distinct groups based on PRS risk groups and MELD groups, which showed different 1-year graft survival (P < .001). There were comparable outcomes between low PRS risk - high MELD and high PRS risk - low MELD group (P = .33). CONCLUSIONS: Donor age, donor BMI, moderate macrosteatosis, and CIT were identified as risk factors for the development of PRS in LT using DBD grafts. PRS risk evaluation may improve donor-to-recipient matching based on their MELD scores.

Outcomes of transplantation for HBV- vs. HCV-related HCC: impact of DAA HCV therapy in a national analysis of >20,000 patients.

BACKGROUND: The development of direct-acting antiviral (DAA) therapy has revolutionized HCV management. We present a large national study comparing post-LT outcomes for HBV-HCC vs. HCV-HCC according to DAA era. METHODS: Data were collected from OPTN/UNOS Registry. Groups included pre-DAA (January 2003-October 2013) and post-DAA (November2013-January2019) eras. Outcomes for patients with HBV(n = 2000) vs. HCV(n = 18,964) were compared in each era. RESULTS: In the pre-DAA era, there were significant differences between HBV-versus HCV, including the percentage of Caucasian race, pre-LT and maximum AFP levels <20 ng/mL, MELD-score, complete tumor necrosis, and vascular invasion. In the post-DAA-era, differences were noted in wait time>9 months, the percentage of Caucasian race, pre-LT and AFP(max) levels<20 ng/mL, and MELD-score. In the pre-DAA-era, the 5-and-10 year survival rates were 80.5% and 71% for HBV-HCC, and 69% and 54.4% for HCV-HCC (p < 0.001); in the post-DAA-era, 5-year survival was 83.4% for HBV-HCC and 78.5% for HCV-HCC(p = 0.08). Independent pre-LT predictors of lower survival included recipient and donor age>50yrs, wait-time>9months, higher MELD-score (p < 0.001), AFP level>20 ng/mL, and MC at diagnosis. HCV status did not predict outcome in the post-DAA-era after adjusting for tumor characteristics. CONCLUSION: After the introduction of effective DAA-HCV therapy, results of LT for HCV-HCC are significantly improved and are no longer statistically different from results in patients with HBV-HCC.

Nominal Operating Envelope of Pod and Pen Style Electronic Cigarettes.

Many Electronic Nicotine Delivery Systems (ENDS) employ integrated sensors to detect user puffing behavior and activate the heating coil to initiate aerosol generation. The minimum puff flow rate and duration at which the ENDS device begins to generate aerosol are important parameters in quantifying the viable operating envelope of the device and are essential to formulating a design of experiments for comprehensive emissions characterization. An accurate and unbiased method for quantifying the flow condition operating envelope of ENDS is needed to quantify product characteristics across research laboratories. This study reports an accurate, unbiased method for measuring the minimum and maximum aerosolization puff flow rate and duration of seven pod-style, four pen-style and two disposable ENDS. The minimum aerosolization flow rate ranged from 2.5 to 23 (mL/s) and the minimum aerosolization duration ranged from 0.5 to 1.0 (s) across the ENDS studied. The maximum aerosolization flow rate was defined to be when the onset of liquid aspiration was evident, at flow rates ranging from 50 to 88 (mL/s). Results are presented which provide preliminary estimates for the effective maximum aerosolization flow rate and duration envelope of each ENDS. The variation in operating envelope observed between ENDS products of differing design by various manufacturers has implications for development of standardized emissions testing protocols and data reporting required for regulatory approval of new products.

Capital juror questionnaires in death-penalty cases: A study of attitudes, denials, and deceptions.

The Sixth Amendment right to an "impartial jury" should guarantee fundamental fairness that in capital cases may literally be a matter of life and death. For ecological validity, the current study focuses on capital jury questionnaires (CJQs) employed in actual death-penalty cases. Study I examined 248 undergraduates and their responses to death-penalty relevant questions. As an MTurk investigation, Study II consisted of 259 community members potentially eligible for capital trial jury trials. Misrepresentations were operationalized as either denials (concealing their true views) or outright deceptions (dissembling the opposite viewpoint). Both studies found that CJQ items were very susceptible to both types of misrepresentation, irrespective of support-life or support-death views. Nearly 30% of undergraduates openly acknowledged that they would misrepresent close to half their CJQ responses. Overall, community members were much more willing to engage in denials and outright deceptions. The discussion focuses on how CJQs could be improved to promote candor about death-penalty views.

Nanoscale electrical conductivity imaging using a nitrogen-vacancy center in diamond.

The electrical conductivity of a material can feature subtle, non-trivial, and spatially varying signatures with critical insight into the material's underlying physics. Here we demonstrate a conductivity imaging technique based on the atom-sized nitrogen-vacancy (NV) defect in diamond that offers local, quantitative, and non-invasive conductivity imaging with nanoscale spatial resolution. We monitor the spin relaxation rate of a single NV center in a scanning probe geometry to quantitatively image the magnetic fluctuations produced by thermal electron motion in nanopatterned metallic conductors. We achieve 40-nm scale spatial resolution of the conductivity and realize a 25-fold increase in imaging speed by implementing spin-to-charge conversion readout of a shallow NV center. NV-based conductivity imaging can probe condensed-matter systems in a new regime not accessible to existing technologies, and as a model example, we project readily achievable imaging of nanoscale phase separation in complex oxides.

Detection of the Emerging Picornavirus Senecavirus A in Pigs, Mice, and Houseflies.

Senecavirus A (SVA) is an emerging picornavirus that has been recently associated with an increased number of outbreaks of vesicular disease and neonatal mortality in swine. Many aspects of SVA infection biology and epidemiology remain unknown. Here, we present a diagnostic investigation conducted in swine herds affected by vesicular disease and increased neonatal mortality. Clinical and environmental samples were collected from affected and unaffected herds and were screened for the presence of SVA by real-time reverse transcriptase PCR and virus isolation. Notably, SVA was detected and isolated from vesicular lesions and tissues of affected pigs, environmental samples, mouse feces, and mouse small intestine. SVA nucleic acid was also detected in houseflies collected from affected farms and from a farm with no history of vesicular disease. Detection of SVA in mice and housefly samples and recovery of viable virus from mouse feces and small intestine suggest that these pests may play a role on the epidemiology of SVA. These results provide important information that may allow the development of improved prevention and control strategies for SVA.

Glomerular Function and Structure in Living Donors: Lessons from Single Nephron Studies.

One third of the kidney transplants performed in the USA come from living kidney donors. The long-term outcome of healthy individuals who donate kidneys is mostly excellent, although recent studies have suggested that living donation is associated with a small absolute increase in the risk of end stage renal failure. Much of our understanding about the progression of kidney disease comes from experimental models of nephron loss. For this reason, living kidney donation has long been of great interest to renal physiologists. This review will summarize the determinants of glomerular filtration and the physiology that underlies post-donation hyperfiltration. We describe the 'remnant kidney' model of kidney disease and the reasons why such progressive kidney disease very rarely ensues in healthy humans following uninephrectomy. We also review some of the methods used to determine glomerular number and size and outline their associations.

Patterned Formation of Highly Coherent Nitrogen-Vacancy Centers Using a Focused Electron Irradiation Technique.

We demonstrate fully three-dimensional and patterned localization of nitrogen-vacancy (NV) centers in diamond with coherence times in excess of 1 ms. Nitrogen δ-doping during chemical vapor deposition diamond growth vertically confines nitrogen to 4 nm while electron irradiation with a transmission electron microscope laterally confines vacancies to less than 450 nm. We characterize the effects of electron energy and dose on NV formation. Importantly, our technique enables the formation of reliably high-quality NV centers inside diamond nanostructures with applications in quantum information and sensing.

Reduced plasma-induced damage to near-surface nitrogen-vacancy centers in diamond.

Understanding plasma etch damage on near-surface nitrogen vacancy (NV) centers in diamond is essential for preserving NV emission in photonic structures and magnetometry systems. We have developed a methodology to compare the optical properties of ensemble NV centers initially 70 nm from the surface brought closer to the surface through etching with O2 plasmas in three different reactors. We employ a conventional reactive ion etcher, a barrel etcher, and a downstream etcher. We find that, irrespective of the etcher used, NV luminescence dims steadily as NVs are brought closer to the surface due to optical and surface effects. When NVs are less than 40 nm from the surface, differences in damage from the three different plasma processes affect the NV emission intensity in different ways. Diamond that is etched using the conventional etching method shows a greatly reduced NV luminescence, whereas NVs 15 nm from the surface still survive when the diamond is etched in the downstream reactor. As a result, downstream etching provides a possible alternative method for low damage etching of diamond for preservation of near surface NV properties.