Crowding induced switching of polymer translocation by the amalgamation of entropy and osmotic pressure

The translocation of polymers is omnipresent in inherently crowded biological systems. We investigate the dynamics of polymer translocation through a pore in free and crowded environments using Langevin dynamics simulation. We observed a location-dependent translocation rate of monomers showcasing counterintuitive behavior in stark contrast to the bead velocity along the polymer backbone. The free energy calculation of asymmetrically placed polymers indicates a critical number of segments to direct receiver-side translocation. For one-sided crowding, we have identified a critical crowding size revealing a nonzero probability of translocation toward the crowded-side. Moreover, we have observed that shifting the polymer toward the crowded-side compensates for one-sided crowding, yielding an equal probability akin to a crowder-free system. In two-sided crowding, a slight variation in crowder size and packing fraction induces a polymer to switch its translocation direction. These conspicuous yet counter-intuitive phenomena are rationalized by minimalistic theoretical arguments based on osmotic pressure and radial entropic forces.

A computational study on structural and functional consequences of nsSNPs in human dopa decarboxylase

The Dopa Decarboxylase (DDC) gene plays an important role in the synthesis of biogenic amines such as dopamine, serotonin, and histamine. Non-synonymous single nucleotide polymorphisms (nsSNPs) in the DDC gene have been linked with various neurodegenerative disorders. In this study, a comprehensive in silico analysis of nsSNPs in the DDC gene was conducted to assess their potential functional consequences and associations with disease outcomes. Using publicly available databases, a complete list of nsSNPs in the DDC gene was obtained. 29 computational tools and algorithms were used to characterise the effects of these nsSNPs on protein structure, function, and stability. In addition, the population-based association studies were performed to investigate possible associations between specific nsSNPs and arthritis. Our research identified four novel DDC gene nsSNPs that have a major impact on the structure and function of proteins. Through molecular dynamics simulations (MDS), we observed changes in the stability of the DDC protein induced by specific nsSNPs. Furthermore, population-based association studies have revealed potential associations between certain DDC nsSNPs and various neurological disorders, including Parkinson's disease and dementia. The in silico approach used in this study offers insightful information about the functional effects of nsSNPs in the DDC gene. These discoveries provide insight into the cellular processes that underlie cognitive disorders. Furthermore, the detection of disease-associated nsSNPs in the DDC gene may facilitate the development of tailored and targeted therapy approaches.Communicated by Ramaswamy H. Sarma.

Management of Length Unstable Femur Fractures in Children by Flexible Intramedullary Nails: A Systematic Review

PURPOSE OF THE STUDY

Surgical options for paediatric femoral fractures include fl exible intramedullary nailing (FIN), plating, and external fi xators. Length unstable fractures are usually spiral, long oblique, or comminuted and are often associated with > 2 cm of shortening. The purpose of this study was to see whether FIN is effective for managing unstable femur fractures in children.

MATERIAL AND METHODS

An electronic literature search was performed up to 25 February 2022 in Cochrane Library, PubMed, and Embase databases using a combination of MeSH search terms and keywords related to the population (e.g., "child" AND "diaphyses" AND "femur"), and intervention (e.g., "nail" OR "ESIN"). The data extracted included the study details, Demographic data, surgical details, postoperative immobilization, complications, and outcome.

RESULTS

Eight studies with a total sample size of 369 patients were reviewed. The mean operative time, blood loss, and length of stay in the hospital were 67.62±12.32 minutes, 33.82±16.82 ml, and 4.9±1.27 days, respectively. The results were excellent in 61.92% of the patients, satisfactory in 32.61%, and poor in 5.43%. 4.54% of patients had major complications requiring reoperation and 32.46% of patients had minor complications. the most common complication was nail prominence seen in 26.30% of patients. Locked Ender's nail was associated with the least reoperation, malunion, and LLD rate compared to other types of FIN.

CONCLUSIONS

FIN along with a single walking spica cast is a good choice in all forms of paediatric femoral fracture patterns allowing proper alignment and rotation. Locked Ender's nail is safe and effective for managing unstable paediatric femur fracture.

KEY WORDS

pediatric femur fracture, length unstable, fl exible intramedullary nailing, submuscular plating, Flynn criterion.

Prospective Characterization of Circulating Tumor Cell Kinetics in Patients with Localized Lung Cancer Treated with Radiotherapy or Chemoradiotherapy with Definitive Intent

PURPOSE/OBJECTIVE(S)

To characterize circulating tumor cell (CTC) kinetics in response to definitive therapy in patients with local or locoregional lung cancer and identify CTC kinetic profiles associated with favorable disease response versus progression.

MATERIALS/METHODS

In this single-institution prospective correlative biomarker study, we enrolled patients receiving definitive intent radiotherapy (RT) or chemoradiotherapy for non-metastatic lung cancer. Blood specimens were collected prior to RT (baseline), during RT and at follow up visits up to 24 months post RT. Subsequent lines of therapy were administered per standard of care. CTCs were captured and enumerated using a previously reported nanotechnology-based assay functionalized with aEpCAM, aHER-2, and aEGFR to facilitate biomimetic cell rolling and dendrimer-mediated multivalent binding. Disease status was assessed per RECIST 1.1 criteria. CTC kinetics and absolute values were analyzed to identify patterns associated with disease control versus progression.

RESULTS

We enrolled 24 patients with median follow up of 8 months corresponding to 114 CTC measurements. Seven patients (30%) had biopsy proven disease, while 17 (70%) were diagnosed based on clinical and radiographic features alone. Nineteen patients (79%) received stereotactic body radiation therapy. Median baseline CTC count was 12.6 CTCs/ml (range 0-290) and post RT decreased to median 4 CTCs/ml (0-42.7). For 95% of patients, a favorable kinetic profile (defined as stable CTC count, decreased CTC count or <24 CTCs/ml corresponding to the 80th percentile) during radiotherapy or at the time of first follow up corresponded to local control of the irradiated lesion. Five patients (20%) experienced disease progression within the follow up period. In the two patients with local progression of the irradiated lesion, the CTC count rose >10 fold prior to or at the time of radiographic detection of progression. In the three patients with systemic progression, CTC count rose 1.46-5.8-fold at the time of progression. Notably, four of the five patients with disease progression did not have initial biopsy confirmation of disease but did experience a CTC elevation at the time of progression.

CONCLUSION

Our data suggests CTCs may serve as a biomarker for response to therapy in patients being treated with RT with definitive intent for early stage or locally advanced lung cancer. This finding is of importance given important limitations in obtaining pathologic confirmation of disease in select patients and challenges distinguishing disease progression versus benign post radiotherapy radiographic changes. Further studies are needed to characterize the predictive and prognostic value of circulating biomarker levels and kinetics in lung cancer.

Comprehensive bioinformatics analysis of structural and functional consequences of deleterious missense mutations in the human QDPR gene

Quinonoid dihydropteridine reductase (QDPR) is an enzyme that regulates tetrahydrobiopterin (BH4), a cofactor for enzymes involved in neurotransmitter synthesis and blood pressure regulation. Reduced QDPR activity can cause dihydrobiopterin (BH2) accumulation and BH4 depletion, leading to impaired neurotransmitter synthesis, oxidative stress, and increased risk of Parkinson's disease. A total of 10,236 SNPs were identified in the QDPR gene, with 217 being missense SNPs. Over 18 different sequence-based and structure-based tools were employed to assess the protein's biological activity, with several computational tools identifying deleterious SNPs. Additionally, the article provides detailed information about the QDPR gene and protein structure and conservation analysis. The results showed that 10 mutations were harmful and linked to brain and central nervous system disorders, and were predicted to be oncogenic by Dr. Cancer and CScape. Following conservation analysis, the HOPE server was used to analyse the effect of six selected mutations (L14P, V15G, G23S, V54G, M107K, G151S) on the protein structure. Overall, the study provides insights into the biological and functional impact of nsSNPs on QDPR activity and the potential induced pathogenicity and oncogenicity. In the future, research can be conducted to systematically evaluate QDPR gene variation through clinical studies, investigate mutation prevalence across different geographical regions, and validate computational results with conclusive experiments.Communicated by Ramaswamy H. Sarma.

A Meta-Analysis on Comparison of Open vs Closed Reduction of Gartland Type 3 Supracondylar Humerus Fractures in Children

PURPOSE OF THE STUDY Although there are numerous studies on outcomes and comparison of open and closed reduction but there is no clarity on relationship between outcomes and complications with type of surgical intervention done for Type 3 Gartland supracondylar humerus fracture. The aim of this study is to compare the outcomes and complications of closed vs open reduction in Type 3 Gartland supracondylar humerus fractures. MATERIAL AND METHODS Electronic literature searches of Embase, MEDLINE and the Cochrane Library was conducted in February 2022 using the terms "supracondylar", "humerus", "fracture", "Gartland type 3" and synonymous. The data extracted included the study details, demographic data, procedure performed, final functional and cosmetic outcome according to Flynn criteria and complications of included studies. RESULTS Pooled data analysis revealed no significant difference in mean satisfactory outcome rate according to Flynn cosmetic criteria in open group (97%, 95% CI 95.5%-98.5%), as compared to closed group (97.5%, 95% CI 96.3%-98.7%), although a statistically significant difference in mean satisfactory rate according to Flynn functional criteria in open group (93.4%, 95% CI 90.8%- 96.1%) as compared to closed group (98.5%, 95% CI 97.5%-99.4%) was noted. On separate comparison of the two-arm studies, closed reduction favoured better functional outcomes (RR 0.92, 95% CI 0.86-0.99). CONCLUSIONS Closed reduction and percutaneous fixation have better functional outcome than open reduction with K-wire fixation. But there was no significant difference in cosmetic outcomes, overall complication rate and nerve injury with either open or closed reduction. The threshold of converting a closed reduction to an open reduction in supracondylar humerus fractures of children should be high. Key words: supracondylar humerus, open reduction, percutaneous pinning, Flynn criteria.

Kinetics of Nanomedicine in Tumor Spheroid as an In Vitro Model System for Efficient Tumor-Targeted Drug Delivery With Insights From Mathematical Models

Numerous strategies have been developed to treat cancer conventionally. Most importantly, chemotherapy shows its huge promise as a better treatment modality over others. Nonetheless, the very complex behavior of the tumor microenvironment frequently impedes successful drug delivery to the tumor sites that further demands very urgent and effective distribution mechanisms of anticancer drugs specifically to the tumor sites. Hence, targeted drug delivery to tumor sites has become a major challenge to the scientific community for cancer therapy by assuring drug effects to selective tumor tissue and overcoming undesired toxic side effects to the normal tissues. The application of nanotechnology to the drug delivery system pays heed to the design of nanomedicine for specific cell distribution. Aiming to limit the use of traditional strategies, the adequacy of drug-loaded nanocarriers (i.e., nanomedicine) proves worthwhile. After systemic blood circulation, a typical nanomedicine follows three levels of disposition to tumor cells in order to exhibit efficient pharmacological effects induced by the drug candidates residing within it. As a result, nanomedicine propounds the assurance towards the improved bioavailability of anticancer drug candidates, increased dose responses, and enhanced targeted efficiency towards delivery and distribution of effective therapeutic concentration, limiting toxic concentration. These aspects emanate the proficiency of drug delivery mechanisms. Understanding the potential tumor targeting barriers and limiting conditions for nanomedicine extravasation, tumor penetration, and final accumulation of the anticancer drug to tumor mass, experiments with in vivo animal models for nanomedicine screening are a key step before it reaches clinical translation. Although the study with animals is undoubtedly valuable, it has many associated ethical issues. Moreover, individual experiments are very expensive and take a longer time to conclude. To overcome these issues, nowadays, multicellular tumor spheroids are considered a promising in vitro model system that proposes better replication of in vivo tumor properties for the future development of new therapeutics. In this review, we will discuss how tumor spheroids could be used as an in vitro model system to screen nanomedicine used in targeted drug delivery, aiming for better therapeutic benefits. In addition, the recent proliferation of mathematical modeling approaches gives profound insight into the underlying physical principles and produces quantitative predictions. The hierarchical tumor structure is already well decorous to be treated mathematically. To study targeted drug delivery, mathematical modeling of tumor architecture, its growth, and the concentration gradient of oxygen are the points of prime focus. Not only are the quantitative models circumscribed to the spheroid, but also the role of modeling for the nanoparticle is equally inevitable. Abundant mathematical models have been set in motion for more elaborative and meticulous designing of nanomedicine, addressing the question regarding the objective of nanoparticle delivery to increase the concentration and the augmentative exposure of the therapeutic drug molecule to the core. Thus, to diffuse the dichotomy among the chemistry involved, biological data, and the underlying physics, the mathematical models play an indispensable role in assisting the experimentalist with further evaluation by providing the admissible quantitative approach that can be validated. This review will provide an overview of the targeted drug delivery mechanism for spheroid, using nanomedicine as an advantageous tool.

Does cardiac transplant protect against broken hearts?

Background

Takotsubo cardiomyopathy (TC) is a reversible stress-induced myocardial dysfunction with increased sympathetic activity caused by excessive release of catecholamines playing a central role in its pathophysiology. The occurrence of TC in transplanted hearts is rare given the complete denervation done during transplantation. However, it has been demonstrated that 40% of transplant recipients undergo sympathetic re-innervation. There have only been case reports describing TC in post-transplant recipients.

Purpose

To evaluate the incidence, baseline characteristics and outcomes of TC occurring in heart transplant recipients using Healthcare Cost and Utilization Project (HCUP) National (nationwide) Inpatient Sample (NIS) in United States from 2009 to 2014.

Methods

Using NIS data, we identified patients who underwent cardiac transplantation using ICD9 procedure codes 37.5 and 33.6. Among these patients, we identified those admitted to the hospital with diagnosis of TC based on ICD-9-CM code 429.83. We presented categorical data as percentages and continuous data as mean or median as appropriate.

Results

We identified 257 hospitalizations for TC in heart transplant recipient patients. There was an approximately 9-fold increase in admissions from 11 in 2009 to 95 in 2014. Among patients with TC, the mean age was 65.3±1.8 years and majority were female (76.6%). A majority of patients were Caucasians (63%) followed by smaller proportion of African-Americans (13.2%).

In-patient mortality in patients admitted with TC following heart transplant was 11.3% (n=29). During the hospitalization, 4.8% of patients had cardiogenic shock and 2.8% required mechanical circulatory support. The average length of stay for patients with TC was 16.6±3.3 days. The mean cost of hospitalization for these patients when adjusted for inflation were 237248±55709 dollars.

Conclusion

TC can still occur in substantially in heart transplant recipients and should be considered one of the differential diagnosis in transplant patients presenting to the hospital.

Funding Acknowledgement

Type of funding source: None

A nationwide 16 year analysis of trends and impact of arrythmias in transplant recipients

Background

Orthotopic heart transplantation is the most effective long-term therapy for end-stage heart disease. Denervation of transplanted heart with the loss of autonomic modulation, vasculopathy, utilization of immunosuppressant drugs, and risk of allograft rejection may result in change in the prevalence of arrhythmias in transplanted hearts.

Purpose

To describe the trends, distribution and the clinical impact of arrhythmias in transplanted hearts in a large nationwide population.

Methods

We queried the National Inpatient Sample with administrative codes. Cardiac transplant patients were identified using procedure ICD-9-CM codes 37.5 and 33.6. Common arrhythmias were extracted using appropriate validated ICD-9-CM codes. Statistical Analysis System (SAS) version 9.4 was used for analysis of data.

Results

There was a total of 30,020 hospitalizations of heart transplant recipients between 1999 and 2014 in the United States and 16342 (54.4%) of these had arrhythmias. The prevalence of total arrhythmias increased from 53.6% (n=1,158) in 1999 to 67.3% (n=1,575) in 2014. The most common arrhythmia was atrial fibrillation (26.83%) followed by ventricular tachycardia (22.86%) and the prevalence of individual arrhythmias is as shown in Figure 1.

Cardiogenic shock was higher in transplanted hearts with arrhythmias when compared with patients without arrhythmias (25.96% vs 18.18%; p&lt;0.001). Transplant recipients with arrhythmias were also associated with an increased use of mechanical circulatory device (18.22% vs 12.67%, p&lt;0.001). The use of implantable cardiac defibrillators and permanent pacemaker was also higher in the arrhythmia group (2.19% vs 0.63% and 40.43% vs 30.24% respectively, p&lt;0.0001). However, there was no significant difference in inpatient mortality between transplant recipients with arrhythmias and without arrhythmias (7.72% vs 6.90%, p=0.225). Further, there was no significant difference in frequency of strokes between the groups (4.98% vs 5.08%; p=0.857).

The total hospital cost when adjusted for inflation was significantly higher in the arrhythmic patients, with an average cost of about $570,415±9,590 vs $439,707±8362 in patients without arrhythmias (p&lt;0.0001). The mean length of hospitalization was 44.2±0.8 days in patients with arrhythmias compared to 33.9±0.8 days in patients without arrhythmias (p&lt;0.0001).

Conclusion

A significant proportion of patients with heart transplant have cardiac arrhythmias and are associated with worse in-hospital outcomes of cardiogenic shock, increased length of stay, and cost of hospitalization. However, they are not associated with worse inpatient mortality.

Funding Acknowledgement

Type of funding source: None

A nationwide analysis of 16 year trends in cardiac transplantation for cardiac sarcoidosis

Background

Orthotopic heart transplant (OHT) is indicated for end-stage heart failure due to cardiac sarcoidosis (CS). However, utilization of OHT for CS has been controversial due to concern for involvement of other organs by sarcoidosis affecting long term outcomes.

Purpose

Our objective was to study the trends in OHT in patients with CS in the United States using Healthcare Cost and Utilization Project (HCUP) National (nationwide) Inpatient Sample (NIS) from 1999 to 2014.

Methods

Using NIS data, we identified patients older than 18 years with cardiac sarcoidosis using codes ICD 9-CM codes of 135 and 425.8. Among these patients, we identified those who underwent cardiac transplantation using ICD 9-CM procedure codes 37.5 and 33.6. We presented categorical data as percentages and continuous data as mean or median as appropriate.

Results

A weighted total of 24231 hospitalizations for CS was extracted from 1999 to 2014 of which 248 (1.02%) CS patients underwent OHT. The trends in cardiac transplant for CS is as shown in Figure 1.

The mean age of CS patients undergoing OHT was 51.7±1.1 years and 60.4% (n=150) were males. 114 (45.9%) were Caucasians and 27.8% (n=25) were African-American. 100% of the transplants were performed at medium (n=5) or large sized (n=243) teaching hospitals and 97.9% of cardiac transplants were also done at teaching hospitals. Heart transplants were mostly done in the South (36.3%) followed by Midwest (26.2%), West (25%) and Northeast (12.5%). Private insurance was the major payor source which covered 149 (60.1%) patients followed by Medicare covering 65 (26.2%) patients.

A total of 10 (3.9%) cardiac sarcoidosis patients died during the same hospitalization for cardiac transplantation. Following OHT, 84.2% (n=209) were discharged home and 11.6% (n=29) to short term hospitalization. The mean cost of hospitalization for OHT in CS when adjusted for inflation was 535144±56060 dollars while the average length of stay for heart transplant for CS was 46.2±6.6 days.

Conclusions

Cardiac transplant trends in CS have not changed from 1999 to 2014 despite recent studies showing improved outcomes and are associated with substantial cost of hospitalization and length of stay. Majority of cardiac transplant was done in Caucasians despite cardiac sarcoidosis being more common in African-Americans.

Funding Acknowledgement

Type of funding source: None

A nationwide analysis of 16 year trends in cardiac transplantation for acute myocarditis

Background

Orthotopic heart transplant (OHT) is indicated in 1–8% of patients with myocarditis. However, national trends in the utilization of transplantation and outcomes in myocarditis across the United States are not well established.

Purpose

Our objective was to study the trends and baseline characteristic of myocarditis patients undergoing heart transplant in the United States using Healthcare Cost and Utilization Project (HCUP) National (nationwide) Inpatient Sample (NIS) from 1999 to 2014.

Methods

Using NIS data, we identified patients older than 18 years with myocarditis using codes ICD9 codes of 422.0 and 422.9. Among these patients, we identified those who underwent cardiac transplantation using ICD9 procedure codes 37.5 and 33.6. We presented categorical data as percentages and continuous data as mean or median as appropriate.

Results

We identified a total of 62,264 hospitalizations for myocarditis from 1999–2014. 430 (0.69%) myocarditis patients underwent OHT which consisted of 0.82% of all 29990 cardiac transplants identified in the same period. The trends in OHT for myocarditis is as shown in Figure 1.

The mean age was 32.9±2.4 years and 51.1% (n=219) were females. 235 (54.6%) were Caucasians and 60 (13.9%) were Hispanic. Majority of the transplants were performed at medium (16%) and large sized hospitals (80.4%). Cardiac transplants were mainly done at teaching hospitals (98.9%). Further, with regards to the geographical distribution of transplant procedure, most were done in the West (37.2%) followed by South (25.3%), Northeast (21.4%) and Mid-west (16%) of the United States. Private insurance was the major payor source which covered 245 (58%) patients followed by Medicaid covering 112 (26%) patients.

A total of 26 (6%) myocarditis patients died during the same hospitalization for OHT. In terms of discharge following OHT in myocarditis 85.8% (n=369) were discharged home and 8.1% (n=35) to short term hospitalization. The average length of stay for OHT for myocarditis was 64.3±6.3 days. Also, the mean cost of hospitalization for heart transplant in myocarditis when adjusted for inflation was 789,566±93,108 dollars.

In-patient mortality following OHT was not significantly different in large sized hospital compared to small and medium sized hospitals (7.6% vs 5.7%, p=0.54). However, the cost of hospitalization was significantly lesser in small and medium sized hospitals (588,363±154,349 vs 826,864±106,110 dollars, p&lt;0.0001).

Conclusions

Only a small percentage of OHT is done for myocarditis with high proportion done in female when compared to OHT for other etiologies. Further studies need to be done to compare long term outcomes of heart transplant in myocarditis.

Funding Acknowledgement

Type of funding source: None

P1500Effects of empagliflozin on cardiac function in patients with type 2 diabetes mellitus: echocardiographic substudy of the EMPA-HEART cardiolink-6 trial

Background

The EMPA-HEART trial showed a reduction in left ventricular (LV) mass index by cardiac MRI at 6 months in patients treated with Empagliflozin vs placebo. A secondary analysis of key echocardiographic parameters was performed to provide further insight into the mechanism of LV remodeling.

Methods

All patients enrolled prospectively underwent transthoracic echocardiography (TTE) at baseline and at 6 months. Measurements were performed according to the American Society of Echocardiography guidelines. Key outcomes of interest included changes in diastolic function and right ventricle parameters at 6 months in patients treated with Empagliflozin vs placebo.

Results

A total of 97 patients were enrolled (49 treated with Empagliflozin and 48 in the placebo group). There was no significant difference in the change in average E/E' at 6-months in the Empagliflozin group vs placebo (−0.4 vs +0.2, adjusted difference −0.2, 95% CI [−1.3 to 0.82], p=0.7) Similarly, there was no difference between the groups in secondary TTE parameters (Table 1). Subgroup analyses showed no benefit among patients with baseline LVEF >50% vs. ≤50%, and baseline LV mass index ≥60 g/m2 vs <60 g/m2.

Echocardiographic Parameter Placebo (n=48) Empagliflozin (n=49) Adjusted Difference Between Groups 95% CI P-Value Baseline 6 months Change Baseline 6 months Change LVEF (%)* 55.5 (8.7) 54.3 (8.9) −1.0 (6.5) 58.0 (7.5) 59.1 (8.57) 0.72 (5.1) 2.2 (−0.2, 4.7) 0.1 Diastolic Parameters:   Average E/e' 10.1 (3.1) 10.3 (2.5) 0.2 (3.0) 10.6 (3.0) 10.5 (3.6) −0.4 (2.5) −0.2 (−1.3, 0.8) 0.7   Medial E/e' 12.3 (3.9) 12.5 (3.6) 0.1 (3.7) 12.6 (4.2) 12.6 (5.2) −0.3 (3.3) −0.3 (−1.7, 1.1) 0.7   Lateral E/e' 8.0 (2.8) 8.2 (2.2) 0.2 (2.7) 8.7 (2.6) 8.4 (2.5) −0.4 (2.7) −0.1 (−1.0, 0.8) 0.8   E velocity (cm/sec) 68.6 (15.2) 70.6 (14.7) 1.8 (15.4) 74.4 (18.2) 71.2 (16.8) −3.2 (15.1) −2.3 (−7.9, 3.3) 0.4   A velocity (cm/sec) 74.7 (17.9) 77.9 (18.8) 2.9 (15.9) 76.2 (16.5) 75.8 (14.5) −1.4 (11.7) −3.5 (−8.9, 1.6) 0.2   LA volume index (mL/m2) 32.7 (7.9) 30.8 (8.1) −2.0 (6.7) 30.2 (6.7) 28.7 (5.5) −1.6 (6.5) −0.9 (−3.4, 1.6) 0.5 RV Parameters:   TAPSE (cm) 1.8 (0.5) 1.8 (0.4) 0.1 (0.4) 2.0 (1.2) 1.8 (0.4) −0.3 (1.4) −0.1 (−0.3, 0.1) 0.3   RV S' TDI (cm/sec) 10.9 (2.9) 10.6 (2.5) −0.1 (2.2) 10.4 (2.7) 10.2 (2.6) −0.4 (2.0) −0.3 (−1.2, 0.5) 0.4 *Measured by cardiac MRI. LA, left atrium; LVEF, left ventricular ejection fraction; RV, right ventricle; TAPSE, tricuspid annular plane systolic excursion; TDI, tissue Doppler imaging. Data expressed as mean (standard deviation).

Conclusion

This study showed no significant change in key echocardiographic parameters in patients treated with Empagliflozin, suggesting that changes in loading conditions induced by empagliflozin (i.e. preload) do not mediate the reduction in LV mass.

P5602Comparison of innominate vs axillary artery cannulation for cerebral protection on neurocognitive outcomes in aortic surgery: a pre-specified analysis of the ACE CardioLink-3 randomised trial

Background

Success after aortic surgery depends on avoidance of neurocognitive dysfunction, thus novel adjuncts to proximal aortic surgery must be evaluated for efficacy of cerebral protection during circulatory arrest. We report the primary neurocognitive results from the ACE CardioLink-3 randomised controlled trial comparing innominate to axillary artery cannulation for cerebral protection (NCT02554032).

Methods

The primary safety endpoint was the proportion of patients with new radiologically severe ischaemic cerebral lesions found on post-operative versus pre-operative diffusion weighted magnetic resonance imaging (DW-MRI). Neurocognitive outcomes were assessed using the Mini-Mental State Exam (MMSE), and the Montreal Cognitive Assessment (MoCA). Continuous and binary outcomes were analysed using ANCOVA (controlling for baseline score) and chi-square/Fisher's exact tests.

Results

Of the 111 patients randomised, 102 patients were included in the primary safety per-protocol analysis. The primary safety outcome (significant new ischaemic lesions on DW-MRI) occurred in 34% in the innominate group and 38.8% in the axillary group (OR 0.81; 0.41 to 1.60; P=0.0009 for non-inferiority). Rates of post-operative stroke/transient ischaemic attack, seizure, delirium, and encephalopathy were similar between groups. The rate of patients with a post-operative MoCA score less than 26 was 44.9% and 39.1% in the innominate and axillary groups respectively (P=0.807). A post-operative MMSE score of less than 24 was observed in 2% vs. 6.5% of the patients in the innominate and axillary groups respectively (P=0.866). A >1-point decrease in the MoCA score from pre-operatively to post-operatively was seen in 32.7% and 34.8% in the innominate and axillary groups respectively (P=0.962). A >1-point decrease in the MMSE score from pre-to post-operative was observed in 20.4% in the innominate artery group compared with 30.4% in the axillary group (P=0.346).

Conclusion

Post-operative neurocognitive dysfunction and DW-MRI incidence of severe ischaemic lesions did not differ in patients randomised to innominate artery cannulation vs, conventional axillary artery cannulation, though the burden of new severe ischaemic lesions is high in both groups.

P3753Does empagliflozin modulate the autonomic system among patients with type 2 diabetes and coronary artery disease? Insights from the Holter sub-study of the EMPA-Heart CardioLink-6 Randomised Trial

Introduction

The mechanism behind how empagliflozin, a sodium-glucose co-transporter 2 (SGLT2) inhibitor, reduces all-cause and cardiovascular mortality among patients with type 2 diabetes (T2DM) and coronary artery disease (CAD) is unknown. Autonomic tone, as reflected by changes in heart rate variability (HRV), is an established prognosticator in patients with CAD and/or heart failure.

Purpose

To assess if empagliflozin treatment changes HRV in subjects with T2DM and CAD.

Methods

In the double-blind EMPA-Heart trial, 97 subjects with T2DM and CAD were randomised to empagliflozin 10 mg/day or placebo for 6 months and underwent 24-hour Holter monitoring at baseline and 6 months. Using automated algorithms, time and frequency HRV domain measures were obtained (standard deviation of NN intervals (SDNN); SD of the average NN intervals for each 5-minute segment (SDANN); root mean square of successive RR interval differences (rMSSD); % interval differences of successive NN intervals >50 ms (pNN50); ratio of low to high frequency (LF/HF)). Changes of these HRV parameters were calculated over 6 months. Between-group differences in HRV parameters were compared using ANCOVA.

Results

Complete Holter data (baseline and 6-month) were available for 68% (n=66) of the cohort. The average heart rate (HR) at baseline/6 months was 69.5±9.8 bpm/72.8±8.1 bpm and 76±10.4 bpm/76.5±10.6 in the placebo group and empagliflozin group, respectively. Both groups had similar changes in average HR over 6 months. Key Holter data are summarised in the table. SDNN and SDANN were higher in the placebo vs. empagliflozin group at 6 months; no significant difference was noted for all other measures.

Empagliflozin 10 mg/day (n=33) Placebo (n=33) Adjusted difference between Empagliflozin and Placebo (ANCOVA) Baseline, Mean (SD) 6-month, Mean (SD) Baseline, Mean (SD) 6-month, Mean (SD) Mean, (95% CI) P-value SDNN (ms) 100.49 (43.74) 98.05 (38.86) 109.35 (30.02) 125.08 (43.83) −18.55 (−34.28, −2.82) 0.022 SDANN (ms) 86.84 (39.34) 83.76 (35.53) 94.70 (28.52) 118.28 (77.41) −20.24 (−37.27, −3.21) 0.021 rMSSD (ms) 27.00 (11.84) 27.22 (13.48) 28.00 (11.58) 27.17 (9.38) −1.23 (−6.02, 3.55) 0.608 pNN50 (%) 7.81 (7.59) 8.32 (9.51) 8.26 (7.8) 6.93 (5.35) 0.51 (−2.61, 3.62) 0.746 LF/HF ratio 1.63 (0.52) 1.65 (0.51) 1.53 (0.43) 1.83 (0.82) −0.08 (−0.38, 0.22) 0.602

Conclusions

Among subjects with T2DM and CAD, changes in HRV over 6 months were similar in the empagliflozin and placebo arms suggesting that the mortality benefit conferred by empagliflozin is not associated with positive modulation of autonomic tone.

Acknowledgement/Funding

This trial was supported by an unrestricted investigator-initiated study grant from Boehringer Ingelheim.

Wear Behavior of Graded Glass/Zirconia Crowns and Their Antagonists

Monolithic zirconia crowns have become very popular; their surface finish is considered a key factor for restoration longevity. While polishing has shown excellent results in vivo, the surface glass infiltration of zirconia may offer superior damage resistance and aesthetic advantages by using tooth-colored glasses. Thus, the purpose of this study is to evaluate the efficacy of polishing and glass infiltration on the wear behavior of monolithic zirconia crowns. The wear behavior of intact natural molar teeth was investigated as a reference. Zirconia crowns were divided into 3 groups: PolZ-sintered then polished; PolGZ-polished in the presintered state and then glass infiltrated and sintered; NoPolGZ-as machined, glass infiltrated and sintered. Crowns were adhesively bonded to a dentin-like abutment. Zirconia crowns and molar teeth ( n = 15) were subjected to contact-slide-liftoff cyclic loading (200 N, 1.25 million cycles) with a steatite sphere ( r = 3 mm) as an antagonist in water. Surface and subsurface damages were investigated with optical and scanning electron microscopies. Wear depth and volume loss were determined with micro-computed tomography. PolGZ and NoPolGZ crowns exhibited shallow wear scars, where material loss remained within the glass/zirconia layer with no visible cracks. Meanwhile, PolZ crowns presented no visible wear damage. Volume loss (mm³) in the steatite antagonist was as follows (mean ± SD): PolZ = 0.022 ± 0.007, PolGZ = 0.011 ± 0.004, and NoPolGZ = 0.014 ± 0.006. Molar teeth yielded no measurable wear on the antagonist, while the wear scar on the teeth was greater than that on zirconia crowns, ranging from 0.07 to 0.35 mm³. The combination of polishing and glass infiltration on the occlusal surface of monolithic zirconia crowns yielded reduced wear on both crown and antagonist.

A neutral wind instrument for nano-satellite platforms

Here we describe the first neutral wind sensor developed specifically for use on resource limited nano-satellite platforms. The instrument is a next generation redesign of the ram wind sensor flown on the Communications/Navigation Outage Forecasting System satellite for measurements of neutral velocity, temperature, and composition. Results of subsystem tests in vacuum conditions show low-power operation, promising design, and good resolution of measured parameters over the operational pressure and energy ranges expected in the low Earth orbit environment.

Capturing Identity and Fate Ex Vivo: Stem Cells from the Mouse Blastocyst

During mouse preimplantation development, three molecularly, morphologically, and spatially distinct lineages are formed, the embryonic epiblast, the extraembryonic primitive endoderm, and the trophectoderm. Stem cell lines representing each of these lineages have now been derived and can be indefinitely maintained and expanded in culture, providing an unlimited source of material to study the interplay of tissue-specific transcription factors and signaling pathways involved in these fundamental cell fate decisions. Here we outline our current understanding of the derivation, maintenance, and properties of these in vitro stem cell models representing the preimplantation embryonic lineages.

A versatile retarding potential analyzer for nano-satellite platforms

The design of the first retarding potential analyzer (RPA) built specifically for use on resource-limited cubesat platforms is described. The size, mass, and power consumption are consistent with the limitations of a nano-satellite, but the performance specifications are commensurate with those of RPAs flown on much larger platforms. The instrument is capable of measuring the ion density, temperature, and the ram component of the ion velocity in the spacecraft reference frame, while also providing estimates of the ion composition. The mechanical and electrical designs are described, as are the operating modes, command and data structure, and timing scheme. Test data obtained using an ion source inside a laboratory vacuum chamber are presented to validate the performance of the new design.

Measuring genetic knowledge: a brief survey instrument for adolescents and adults

Basic knowledge of genetics is essential for understanding genetic testing and counseling. The lack of a written, English language, validated, published measure has limited our ability to evaluate genetic knowledge of patients and families. Here, we begin the psychometric analysis of a true/false genetic knowledge measure. The 18-item measure was completed by parents of children with congenital heart defects (CHD) (n = 465) and adolescents and young adults with CHD (age: 15-25, n = 196) with a mean total correct score of 12.6 [standard deviation (SD) = 3.5, range: 0-18]. Utilizing exploratory factor analysis, we determined that one to three correlated factors, or abilities, were captured by our measure. Through confirmatory factor analysis, we determined that the two factor model was the best fit. Although it was necessary to remove two items, the remaining items exhibited adequate psychometric properties in a multidimensional item response theory analysis. Scores for each factor were computed, and a sum-score conversion table was derived. We conclude that this genetic knowledge measure discriminates best at low knowledge levels and is therefore well suited to determine a minimum adequate amount of genetic knowledge. However, further reliability testing and validation in diverse research and clinical settings is needed.