APPE unreadiness - The other side of the coin.

INTRODUCTION: Student readiness for Advanced Pharmacy Practice Experiences (APPEs) has not been explicitly defined in literature or standards. Readiness for APPEs is a programmatic requirement of all schools and colleges of pharmacy (schools), leaving schools to determine their own assessments of APPE readiness. Current literature provides no consensus on the definition of APPE readiness nor the assessments or benchmarks used to evaluate APPE readiness. Schools have an opportunity to improve efforts to identify students at risk for poor APPE performance and provide early intervention. COMMENTARY: Due to a lack of consensus, it may be easier to describe students who are not ready for APPEs than it is to describe students who are APPE ready. APPE unreadiness is defined by the authors as those who require significant preceptor instruction on foundational competencies such as knowledge, skills, and/or attitudes and therefore are unable to meaningfully engage in application-based patient care activities. By adding focus to APPE unreadiness within APPE readiness programs, pharmacy schools may be able to more readily identify and remediate students who are at risk of failing one or more APPE rotations. IMPLICATIONS: We provide four recommendations for schools to consider. These are focused on assessing APPE readiness to qualify and quantify APPE unready students. By assessing APPE unreadiness, schools can make continuous quality improvement to ensure that preceptors, sites, students, and faculty can have the ongoing confidence that APPE students are all ready to meaningfully engage on rotation.

Combining Oxygenated Cold Perfusion With Normothermic Ex Vivo Perfusion Improves the Outcome of Donation After Circulatory Death Porcine Kidney Transplantation.

BACKGROUND: Ex vivo machine perfusion is a novel preservation technique for storing and assessing marginal kidney grafts. All ex vivo perfusion techniques have advantages and shortcomings. The current study analyzed whether a combination of oxygenated hypothermic machine perfusion (oxHMP) followed by a short period of normothermic ex vivo kidney perfusion (NEVKP) could combine the advantages of both techniques. METHODS: Porcine kidneys were exposed to 30 min of warm ischemia followed by perfusion. Kidneys underwent either 16-h NEVKP or 16-h oxHMP. The third group was exposed to 16-h oxHMP followed by 3-h NEVKP (oxHMP + NEVKP group). After contralateral nephrectomy, grafts were autotransplanted and animals were followed up for 8 d. RESULTS: All animals survived the follow-up period. Grafts preserved by continuous NEVKP showed improved function with lower peak serum creatinine and more rapid recovery compared with the other 2 groups. Urine neutrophil gelatinase-associated lipocalin, a marker of kidney injury, was found to be significantly lowered on postoperative day 3 in the oxHMP + NEVKP group compared with the other 2 groups. CONCLUSIONS: A short period of NEVKP after oxHMP provides comparable short-term outcomes to prolonged NEVKP and is superior to oxHMP alone. A combination of oxHMP with end-ischemic NEVKP could be an attractive, practical strategy to combine the advantages of both preservation techniques.

Transition Metal ß-Diketonate Adhesion Promoters in Epoxy-Anhydride Resin.

Epoxy to copper adhesion supports the reliability of numerous structures in electronic packaging. Compared to substrate pre-treatment, processing and cost considerations are in favor of adhesion promoters loaded in epoxy formulations. In this work, first row transition metal ß-diketonates present such a compelling case when added in epoxy/anhydride resins: over 30% (before moisture aging) and 50% (after moisture aging) enhancement in lap shear strength are found using Co(II) and Ni(II) hexafluoroacetylacetonate. From extensive X-ray photoelectron spectroscopy (XPS) analyses on the adhesively failed sample surfaces, increased population of oxygen-containing functional groups, especially esters, is linked to the adhesion improvement. Assisted by XPS depth profile on the fractured epoxy side and in situ Fourier-transform infrared spectroscopy (FTIR), the previously discovered latent cure characteristics endowed by the metal chelates interacting with phosphine catalysts are regarded pivotal for pacing the anhydride consumption and allowing interfacial esterification reactions to occur. Further examinations on the XPS binding energy shifts and dielectric properties of the doped epoxy also reveal metal-polymer coordination that contribute to the adhesion and moisture resistance properties. These findings should stimulate future research of functional additives targeting at cure kinetics control and polar group coordination ideas for more robust epoxy-Cu joints.

Corrigendum to: A novel fully automated MRI-based deep-learning method for classification of 1p/19q co-deletion status in brain gliomas.

[This corrects the article DOI: 10.1093/noajnl/vdaa066.].

Dynamic Metabolic Changes During Prolonged Ex Situ Heart Perfusion Are Associated With Myocardial Functional Decline.

Ex situ heart perfusion (ESHP) was developed to preserve and evaluate donated hearts in a perfused beating state. However, myocardial function declines during ESHP, which limits the duration of perfusion and the potential to expand the donor pool. In this research, we combine a novel, minimally-invasive sampling approach with comparative global metabolite profiling to evaluate changes in the metabolomic patterns associated with declines in myocardial function during ESHP. Biocompatible solid-phase microextraction (SPME) microprobes serving as chemical biopsy were used to sample heart tissue and perfusate in a translational porcine ESHP model and a small cohort of clinical cases. In addition, six core-needle biopsies of the left ventricular wall were collected to compare the performance of our SPME sampling method against that of traditional tissue-collection. Our state-of-the-art metabolomics platform allowed us to identify a large number of significantly altered metabolites and lipid species that presented comparable profile of alterations to conventional biopsies. However, significant discrepancies in the pool of identified analytes using two sampling methods (SPME vs. biopsy) were also identified concerning mainly compounds susceptible to dynamic biotransformation and most likely being a result of low-invasive nature of SPME. Overall, our results revealed striking metabolic alterations during prolonged 8h-ESHP associated with uncontrolled inflammation not counterbalanced by resolution, endothelial injury, accelerated mitochondrial oxidative stress, the disruption of mitochondrial bioenergetics, and the accumulation of harmful lipid species. In conclusion, the combination of perfusion parameters and metabolomics can uncover various mechanisms of organ injury and recovery, which can help differentiate between donor hearts that are transplantable from those that should be discarded.

Heart Failure and Drug Therapies: A Metabolic Review.

Cardiovascular disease is the leading cause of mortality globally with at least 26 million people worldwide living with heart failure (HF). Metabolism has been an active area of investigation in the setting of HF since the heart demands a high rate of ATP turnover to maintain homeostasis. With the advent of -omic technologies, specifically metabolomics and lipidomics, HF pathologies have been better characterized with unbiased and holistic approaches. These techniques have identified novel pathways in our understanding of progression of HF and potential points of intervention. Furthermore, sodium-glucose transport protein 2 inhibitors, a drug that has changed the dogma of HF treatment, has one of the strongest types of evidence for a potential metabolic mechanism of action. This review will highlight cardiac metabolism in both the healthy and failing heart and then discuss the metabolic effects of heart failure drugs.

The Effects of Participation in a Transitions of Care Simulation on Pharmacy Students' Empathy.

Objective. To assess the effects of a transitions of care simulation on the empathy of pharmacy students.Methods. Pharmacy students volunteered to complete a four-hour transitions of care simulation. Students were "discharged" from a simulation hospital by trained actors posing as health care providers and provided with a discharge packet, prescriptions, bus route, and bus pass. Students navigated public transportation to obtain discharge medications at a community pharmacy and then returned "home" to debrief with study investigators. Demographics were analyzed using descriptive statistics. The Kiersma-Chen Empathy Scale (KCES) was administered pre- and post-simulation, along with open-ended questions.Results. Median composite empathy scores on the KCES increased significantly from 92 to 98 following completion of the simulation. Significant increases were seen on four of the 15 questionnaire items on which themes largely involved taking patients' feelings into account when making therapeutic decisions. These four items were: "I will not allow myself to be influenced by someone's feelings when determining the best treatment," "I have difficulty identifying with someone else's feelings," "It is necessary for a health care practitioner to be able to view the world from another person's perspective," and "A health care practitioner should not be influenced by someone's feelings when determining the best treatment."Conclusion. Results of this pilot study demonstrated a significant increase in pharmacy students' overall empathy. Replicating this experiment on a larger scale may provide further insight regarding the impact of participating in simulations on transitions of care on pharmacy students' empathy.

Echocardiographic assessment of left ventricular function in ex situ heart perfusion using pump-supported and passive afterload working mode: a pilot study.

Ex situ heart perfusion (ESHP) has been developed to decrease cold ischemia time and allow metabolic assessment of donor hearts prior to transplantation. Current clinical ESHP systems preserve the heart in an unloaded condition and only evaluate the cardiac metabolic profile. In this pilot study we performed echocardiographic functional assessment using two alternative systems for left ventricular (LV) loading: pump supported afterload working mode (SAM) and passive afterload working modes (PAM). Six hearts were procured from male Yorkshire pigs. During cold ischemia, hearts were mounted on our custom made ESHP circuit and a 3D-printed enclosure for the performance of echocardiography with a standard TEE probe. Following perfusion with Langherdorf mode of the unloaded heart, the system was switched into different working modes to allow LV loading and functional assessment: pump supported (SAM) and passive (PAM). Echocardiographic assessment of left ventricular function in the donor hearts was performed in vivo and at 1 h of ESHP with SAM, after 4.5 h with PAM and after 5.5 h with SAM. We obtained good quality epicardial echocardiographic images at all time points allowing a comprehensive LV systolic assessment. All indices showed a decrease in LV systolic function throughout the trial with the biggest drop after heart harvesting. We demonstrated the feasibility of echocardiographic functional assessment during ESHP and two different working modes. The expected LV systolic dysfunction consisted of a reduction in EF, FAC, FS, and strain throughout the experiment with the most significant decrease after harvesting.

Redo sternotomy versus left ventricular assist device explant as risk factors for early mortality following heart transplantation.

OBJECTIVES: There is an increasing proportion of patients with a previous sternotomy (PS) or durable left ventricular assist device (LVAD) undergoing heart transplantation (HT). We hypothesized that patients with LVAD support at the time of HT have a lower risk than patients with PS and may have a comparable risk to patients with a virgin chest (VC). METHODS: This is a single-centre retrospective cohort study of all adults who underwent primary single-organ HT between 2002 and 2017. Multivariable Cox regression analyses were performed to compare 30-day and 1-year mortality between transplanted patients with a VC (VC-HT), a PS (PS-HT) or an LVAD explant (LVAD-HT). RESULTS: Three hundred seventy-nine patients were analysed (VC-HT: 196, PS-HT: 94, LVAD-HT: 89). A larger proportion of patients in the LVAD-HT group were males (83%), had blood group O (52%), non-ischaemic aetiology (70%) and sensitization (67%). The PS-HT group had a higher frequency of patients with congenital heart disease (30%) and PSs compared to LVAD-HT patients (P < 0.001). PS-HT and LVAD-HT patients required a longer bypass time (P < 0.001) and showed a greater estimated blood loss (P < 0.001). Postoperatively, LVAD-HT required haemodialysis more frequently than the VC-HT group (P = 0.031). Multivariable analyses found that PS-HT patients had increased 30-day mortality compared to VC-HT [hazard ratio (HR) 2.63, 95% confidence interval (CI) 1.15-6.01; P = 0.022] while LVAD-HT did not (HR 2.17, 95% CI 0.96-4.93; P = 0.064). At 1-year, neither PS-HT nor LVAD-HT groups were significantly associated with increased mortality compared to VC-HT. CONCLUSIONS: Transplants in recipients with PS-HT demonstrated increased early mortality compared to VC-HT patients. Although LVAD explant is often technically challenging, this population demonstrated similar mortality compared to those VC-HT patients. The chronic and perioperative support provided by the LVAD may play a favourable role in early patient outcomes compared to other redo sternotomy patients.

Neurological emergencies associated with COVID-19: stroke and beyond.

Novel coronavirus disease (COVID-19) was declared a global pandemic on March 1, 2020. Neurological manifestations are now being reported worldwide, including emergent presentation with acute neurological changes as well as a comorbidity in hospitalized patients. There is limited knowledge on the neurologic manifestations of COVID-19 at present, with a wide array of neurological complications reported, ranging from ischemic stroke to acute demyelination and encephalitis. We report five cases of COVID-19 presenting to the ER with acute neurological symptoms, over the course of 1 month. This includes two cases of ischemic stroke, one with large-vessel occlusion and one with embolic infarcts. The remainders of the cases include acute tumefactive demyelination, isolated cytotoxic edema of the corpus callosum with subarachnoid hemorrhage, and posterior reversible encephalopathy syndrome (PRES).

Comparing Donor Heart Assessment Strategies During Ex Situ Heart Perfusion to Better Estimate Posttransplant Cardiac Function.

BACKGROUND: Ex situ heart perfusion (ESHP) limits ischemic periods and enables continuous monitoring of donated hearts; however, a validated assessment method to predict cardiac performance has yet to be established. We compare biventricular contractile and metabolic parameters measured during ESHP to determine the best evaluation strategy to estimate cardiac function following transplantation. METHODS: Donor pigs were assigned to undergo beating-heart donation (n = 9) or donation after circulatory death (n = 8) induced by hypoxia. Hearts were preserved for 4 hours with ESHP while invasive and noninvasive (NI) biventricular contractile, and metabolic assessments were performed. Following transplantation, hearts were evaluated at 3 hours of reperfusion. Spearman correlation was used to determine the relationship between ESHP parameters and posttransplant function. RESULTS: We performed 17 transplants; 14 successfully weaned from bypass (beating-heart donation versus donation after circulatory death; P = 0.580). Left ventricular invasive preload recruitable stroke work (PRSW) (r = 0.770; P = 0.009), NI PRSW (r = 0.730; P = 0.001), and NI maximum elastance (r = 0.706; P = 0.002) strongly correlated with cardiac index (CI) following transplantation. Right ventricular NI PRSW moderately correlated to CI following transplantation (r = 0.688; P = 0.003). Lactate levels were weakly correlated with CI following transplantation (r = -0.495; P = 0.043). None of the echocardiography measurements correlated with cardiac function following transplantation. CONCLUSIONS: Left ventricular functional parameters, especially ventricular work and reserve, provided the best estimation of myocardial performance following transplantation. Furthermore, simple NI estimates of ventricular function proved useful in this setting. Right ventricular and metabolic measurements were limited in their ability to correlate with myocardial recovery. This emphasizes the need for an ESHP platform capable of assessing myocardial contractility and suggests that metabolic parameters alone do not provide a reliable evaluation.

African Americans experience disproportionate neurodegenerative changes in the medulla and upper cervical spinal cord in early multiple sclerosis.

OBJECTIVE: To compare the temporal changes in the 3-dimensional (3D) structure of the medulla-upper cervical spinal cord region in African American (AA) and white multiple sclerosis (MS) patients to identify early patterns of anatomical change prior to progressive symptom development. METHODS: Standardized 3-Tesla 3D brain MRI studies were performed at two time points on AA and white MS patients along with controls. Longitudinal changes in volume, surface area, tissue compliance, and surface texture measured in total and within ventral and dorsal compartments were studied. Independent regression models were constructed to evaluate differences between groups. RESULTS: Thirty-five individuals were studied, 10 AA with MS (female (F): 8; median age [IQR]=33.8 years (y) [10.9], median disease duration: 11.8y [11.3]), 20 white MS patients (F: 10; 35.6y [17.4], 7.23y [8.83], and 5 controls (F: 2, 51.8y [10.2]). Expanded Disability Status Scale scores were 0.0 at baseline and at the second MRI time point. Within the medulla-upper cervical spinal cord, AA versus white MS patients exhibited greater rates of atrophy in total (p<0.0001) and within the ventral (p<0.0001) and dorsal (p<0.0001) compartments, reduced surface area (p<0.0001), and reduced tissue compliance in the ventral (p=0.002) and dorsal (p=0.0005) compartments. The rate of change at the dorsal surface, but not the ventral surface, between MRI time points was also greater in AA relative to white MS patients (p<0.0001). CONCLUSION: Structural changes in distinct anatomical regions of the medulla-upper cervical spinal cord may be reflective of early and disproportionate neurodegeneration in AA MS as compared to whites.

A novel fully automated MRI-based deep-learning method for classification of 1p/19q co-deletion status in brain gliomas.

BACKGROUND: One of the most important recent discoveries in brain glioma biology has been the identification of the isocitrate dehydrogenase (IDH) mutation and 1p/19q co-deletion status as markers for therapy and prognosis. 1p/19q co-deletion is the defining genomic marker for oligodendrogliomas and confers a better prognosis and treatment response than gliomas without it. Our group has previously developed a highly accurate deep-learning network for determining IDH mutation status using T2-weighted (T2w) MRI only. The purpose of this study was to develop a similar 1p/19q deep-learning classification network. METHODS: Multiparametric brain MRI and corresponding genomic information were obtained for 368 subjects from The Cancer Imaging Archive and The Cancer Genome Atlas. 1p/19 co-deletions were present in 130 subjects. Two-hundred and thirty-eight subjects were non-co-deleted. A T2w image-only network (1p/19q-net) was developed to perform 1p/19q co-deletion status classification and simultaneous single-label tumor segmentation using 3D-Dense-UNets. Three-fold cross-validation was performed to generalize the network performance. Receiver operating characteristic analysis was also performed. Dice scores were computed to determine tumor segmentation accuracy. RESULTS: 1p/19q-net demonstrated a mean cross-validation accuracy of 93.46% across the 3 folds (93.4%, 94.35%, and 92.62%, SD = 0.8) in predicting 1p/19q co-deletion status with a sensitivity and specificity of 0.90 ± 0.003 and 0.95 ± 0.01, respectively and a mean area under the curve of 0.95 ± 0.01. The whole tumor segmentation mean Dice score was 0.80 ± 0.007. CONCLUSION: We demonstrate high 1p/19q co-deletion classification accuracy using only T2w MR images. This represents an important milestone toward using MRI to predict glioma histology, prognosis, and response to treatment.

A Fully Automated Deep Learning Network for Brain Tumor Segmentation.

We developed a fully automated method for brain tumor segmentation using deep learning; 285 brain tumor cases with multiparametric magnetic resonance images from the BraTS2018 data set were used. We designed 3 separate 3D-Dense-UNets to simplify the complex multiclass segmentation problem into individual binary-segmentation problems for each subcomponent. We implemented a 3-fold cross-validation to generalize the network's performance. The mean cross-validation Dice-scores for whole tumor (WT), tumor core (TC), and enhancing tumor (ET) segmentations were 0.92, 0.84, and 0.80, respectively. We then retrained the individual binary-segmentation networks using 265 of the 285 cases, with 20 cases held-out for testing. We also tested the network on 46 cases from the BraTS2017 validation data set, 66 cases from the BraTS2018 validation data set, and 52 cases from an independent clinical data set. The average Dice-scores for WT, TC, and ET were 0.90, 0.84, and 0.80, respectively, on the 20 held-out testing cases. The average Dice-scores for WT, TC, and ET on the BraTS2017 validation data set, the BraTS2018 validation data set, and the clinical data set were as follows: 0.90, 0.80, and 0.78; 0.90, 0.82, and 0.80; and 0.85, 0.80, and 0.77, respectively. A fully automated deep learning method was developed to segment brain tumors into their subcomponents, which achieved high prediction accuracy on the BraTS data set and on the independent clinical data set. This method is promising for implementation into a clinical workflow.

Advanced MRI techniques for transcranial high intensity focused ultrasound targeting.

Magnetic resonance guided high intensity focused ultrasound is a novel, non-invasive, image-guided procedure that is able to ablate intracranial tissue with submillimetre precision. It is currently FDA approved for essential tremor and tremor dominant Parkinson's disease. The aim of this update is to review the limitations of current landmark-based targeting techniques of the ventral intermediate nucleus and demonstrate the role of emerging imaging techniques that are relevant for both magnetic resonance guided high intensity focused ultrasound and deep brain stimulation. A significant limitation of standard MRI sequences is that the ventral intermediate nucleus, dentatorubrothalamic tract, and other deep brain nuclei cannot be clearly identified. This paper provides original, annotated images demarcating the ventral intermediate nucleus, dentatorubrothalamic tract, and other deep brain nuclei on advanced MRI sequences such as fast grey matter acquisition T1 inversion recovery, quantitative susceptibility mapping, susceptibility weighted imaging, and diffusion tensor imaging tractography. Additionally, the paper reviews clinical efficacy of targeting with these novel MRI techniques when compared to current established landmark-based targeting techniques. The paper has widespread applicability to both deep brain stimulation and magnetic resonance guided high intensity focused ultrasound.

Comparison of Heart Transplantation Outcomes: Adult Congenital Heart Disease vs Matched Cardiac Patients in a Quaternary Reference Centre.

BACKGROUND: The number of transplantations performed for adult congenital heart disease (ACHD) patients is increasing. We sought to compare survival and post-transplantation complications, including graft failure, rejection, dialysis, and use of a right ventricular assist device, between ACHD and a cohort of dilated (DCM) and ischemic (ICM) cardiomyopathy patients matched by age and year of transplantation. METHODS: We retrospectively reviewed our single-institution heart transplantation database and selected all patients who had surgery from 1988 to 2017. In our primary analysis, we looked at survival and post-transplantation complications across cardiomyopathy groups. Our secondary analysis was matched to mitigate era effects as well as differences in age at transplant. RESULTS: We analyzed a cohort consisting of 303 heart transplant patients with cardiomyopathy due to either 1) ACHD (n = 38), 2) ICM (n = 110), or 3) DCM (n = 155). Kaplan-Meier analysis and a multivariable Cox proportional hazard regression model were used for all-cause mortality, and cause-specific hazard regression for cause-specific mortality and morbidity. There was no statistically significant survival difference across groups. The 1-year survival was 68.5% for ACHD, 85.4% for ICM, and 85.5% for DCM. In multivariable analysis, ICM and DCM patients showed a 66% lower risk of death relative to the ACHD group. The matched analysis showed no significant difference in survival across groups. CONCLUSIONS: ACHD patients represent a growing high-risk patient cohort referred for transplantation. To improve survival outcomes we need to address modifiable risk factors.

Human leukocyte antigen-G donor-recipient matching of the 14-base pair polymorphism protects against cancer after heart transplant.

BACKGROUND: After a transplant, cancer is a leading cause of morbidity and mortality. Human leukocyte antigen-G (HLA-G)-an immune checkpoint molecule-reduces allograft rejection by dampening host immune responses. Reports suggest malignant cells utilize HLA-G to evade the immune system and promote cancer development. Our objective was to evaluate HLA-G donor-recipient polymorphism matching and development of cancer after a heart transplant. METHODS: Recipients (n = 251) and corresponding donors (n = 196) were genotyped retrospectively to identify HLA-G polymorphisms in the 5' regulatory (-725, -201), 3' untranslated (+3,197, +3,187, +3,142, 14-base pair insertion-deletion polymorphism [14-bp indel]) and coding regions (Haplotypes I-VI). Associations between donor-recipient polymorphism matching and development of cancer were assessed through multivariate proportional hazard regression models. RESULTS: Recipient and donor (48.2 ± 12.1 and 35.5 ± 14.3 years, respectively) mean follow-up was 7.2 ± 4.6 years. Overall, 42 (16.7%) recipients developed de novo post-transplant cancer. 14-bp polymorphism matching significantly reduced the proportion of cancer, revealing an independent protective effect (hazard ratio [95% CI]: 0.26 [0.10-0.75]; p = 0.012). Recipients with the 14-bp insertion sequence, whether homozygous or heterozygous, had a lower proportion of cancer (p > 0.008), matching the INS sequence (INS/INS and INS/DEL) protected against cancer (p = 0.002). No differences were seen between matched vs unmatched cohorts regarding all donor-recipient pre-transplant and post-transplant characteristics. No other polymorphisms showed significant associations. CONCLUSIONS: We investigated donor-recipient HLA-G polymorphism matching and development of cancer following a heart transplant. Donor-recipient 14-bp matching was an independent protective factor against cancer development. HLA-G may have a role in therapeutic and diagnostic strategies against cancer. Identifying relevant HLA-G polymorphisms may warrant alterations in immunotherapy to reduce post-transplant cancer risk.

Intramedullary Neurocysticercosis Mimicking Cord Tumor.

Isolated spinal intramedullary involvement by neurocysticercosis is extremely rare. We report a case of a Hispanic female with right-sided weakness, magnetic resonance imaging showing cervical intramedullary lesion. Surgery was performed due to the progressive nature of symptoms. The cervical cord lesion was completely removed; pathology was consistent with degenerated cysticercosis. Progressive clinical improvement with physiotherapy was achieved. Although rare, especially in the absence of intracranial lesions, the diagnosis should be considered in appropriate patient population as it usually presents a peripherally enhancing cystic lesion.

HLA-G +3196 polymorphism as a risk factor for cell mediated rejection following heart transplant.

BACKGROUND: Rejection is a leading cause of mortality following heart transplantation. Human leukocyte antigen-G (HLA-G) is an immune checkpoint which dampens the immune response. Reports suggest elevated HLA-G expression is associated with reduced allograft rejection. Our objective was to evaluate HLA-G polymorphisms and cell mediated rejection (CMR) development. METHODS: Recipients (n = 123) were genotyped to identify relevant HLA-G polymorphisms in the 5'regulatory (-725, -201), 3'untranslated (+3197, +3187, +3142, 14-bp indel) and coding regions (haplotypes 1-6). CMR was evaluated via endomyocardial biopsy (grade ≥ 2R). Univariate/adjusted analyses were conducted via Kaplan Meier and proportional hazard models. RESULTS: Mean recipient age was 48 (±12) years, with a median time to CMR of 4.6 years. 55 (45%) recipients had a biopsy grade ≥ 2R. Adjusted analysis revealed the +3196 G allele as a risk factor for CMR (p = 0.03). Compared to the minor GG genotype, CG had a 47.2% reduction in CMR risk (HR[95% CI] = 0.528 [0.235, 1.184]), while CC had a 66.9% reduction (0.331 [0.144, 0.761]). The recessive effect significantly increased CMR likelihood (2.388 [1.128, 5.059], p = 0.02). CONCLUSION: The HLA-G +3196 G allele was identified as a risk factor for CMR diagnosis. HLA-G may have a role in therapeutic/diagnostic strategies against transplant rejection.

The Implementation of an Adjustable Afterload Module for Ex Situ Heart Perfusion.

PURPOSE: Windkessel impedance analysis has proven to be an effective technique for instituting artificial afterload on ex situ hearts. Traditional fixed parameter afterload modules, however, are unable to handle the changing contractile conditions associated with prolonged ex situ heart perfusion. In this paper, an adjustable afterload module is described comprising of three fully adjustable sub-components: a systemic resistor, a proximal resistor and a compliance chamber. METHODS: Using a centrifugal pump, the systemic resistor and compliance chamber were subjected to testing across their operating ranges, whereby the predictability of resistance and compliance values was evaluated. The components were then assembled, and the full module tested on three separate porcine hearts perfused for 6 h with success defined by the ability to maintain physiological systolic and diastolic aortic pressures across flow rate variability. RESULTS: For both the systemic resistor and compliance chamber, experimental measurements agreed with their theoretical equivalents, with coefficients of determination of 0.99 and 0.97 for the systemic resistor and compliance chamber, respectively. During ex situ perfusion, overall 95% confidence intervals demonstrate that physiological systolic (95-96.21 mmHg) and diastolic (26.8-28.8 mmHg) pressures were successfully maintained, despite large variability in aortic flow. Left ventricular contractile parameters, were found to be in line with those in previous studies, suggesting the afterload module has no detrimental impact on functional preservation. CONCLUSIONS: We conclude that due to the demonstrable control of our afterload module, we can maintain physiological aortic pressures in a passive afterload working mode across prolonged perfusion periods, enabling effective perfusion regardless of contractile performance.