Multiscale Imaging to Monitor Functional SHED-Supported Engineered Vessels

Regeneration of orofacial tissues is hampered by the lack of adequate vascular supply. Implantation of in vitro engineered, prevascularized constructs has emerged as a strategy to allow the rapid vascularization of the entire graft. Given the angiogenic properties of dental pulp stem cells, we hereby established a preclinical model of prevascularized constructs loaded with stem cells from human exfoliating deciduous teeth (SHED) in a 3-dimensional-printed material and provided a functional analysis of their in vivo angiogenesis, vascular perfusion, and permeability. Three different cell-loaded collagen hydrogels (SHED-human umbilical vein endothelial cell [HUVEC], HUVEC with SHED-conditioned medium, and SHED alone) were cast in polylactic acid (PLA) grids and ectopically implanted in athymic mice. At day 10, in vivo positron emission tomography (PETscan) revealed a significantly increased uptake of radiotracer targeting activated endothelial cells in the SHED-HUVEC group compared to the other groups. At day 30, ex vivo micro-computed tomography imaging confirmed that SHED-HUVEC constructs had a significantly increased vascular volume compared to the other ones. Injection of species-specific lectins analyzed by 2-photon microscopy demonstrated blood perfusion of the engineered human vessels in both prevascularized groups. However, in vivo quantification showed increased vessel density in the SHED-HUVEC group. In addition, coinjection of fluorescent lectin and dextran revealed that prevascularization with SHED prevented vascular leakage, demonstrating the active role of SHED in the maturation of human-engineered microvascular networks. This preclinical study introduces a novel PLA prevascularized and implantable construct, along with an array of imaging techniques, to validate the ability of SHED to promote functional human-engineered vessels, further highlighting the interest of SHED for orofacial tissue engineering. Furthermore, this study validates the use of PETscan for the early detection of in vivo angiogenesis, which may be applied in the clinic to monitor the performance of prevascularized grafts.

Balanced anesthesia in pigeons (Columba livia): a protocol that ensures stable vital parameters and feasibility during long surgeries in cognitive neuroscience

In neuroscience, numerous experimental procedures in animal models require surgical interventions, such as the implantation of recording electrodes or cannulas before main experiments. These surgeries can take several hours and should rely on principles that are common in the field of research and medicine. Considering the characteristics of the avian respiratory physiology, the development of a safe and replicable protocol for birds is necessary to minimize side effects of anesthetic agents, circumvent technical limitations due to the insufficient availability of patient monitoring, and to maintain stable intraoperative anesthesia. Through the consistent and responsible implementation of the three R principle of animal welfare in science ("Replace, Reduce, Refine"), we aimed to optimize experimental methods to minimize the burden on pigeons (Columba livia) during surgical procedures. Here, surgeries were conducted under balanced anesthesia and perioperative monitoring of heart rate, oxygen saturation, body temperature, and the reflex state. The protocol we developed is based on the combination of injectable and inhalative anesthetic drugs [ketamine, xylazine, and isoflurane, supported by the application of an opiate for analgesia (e.g., butorphanol, buprenorphine)]. The combination of ketamine and xylazine with a pain killer is established in veterinary medicine across a vast variety of species. Practicability was verified by survival of the animals, fast and smooth recovery quantified by clinical examination, sufficiency, and stability of anesthesia. Independent of painful stimuli like incision or drilling, or duration of surgery, vital parameters were within known physiological ranges for pigeons. Our approach provides a safe and conservative protocol for surgeries of extended duration for scientific applications as well as for veterinary medicine in pigeons which can be adapted to other bird species.

Differences in Discounting Behavior and Brain Responses for Food and Money Reward

Most neuroeconomic research seeks to understand how value influences decision-making. The influence of reward type is less well understood. We used functional magnetic resonance imaging (fMRI) to investigate delay discounting of primary (i.e., food) and secondary rewards (i.e., money) in 28 healthy, normal-weighted participants (mean age = 26.77; 18 females). To decipher differences in discounting behavior between reward types, we compared how well-different option-based statistical models (exponential, hyperbolic discounting) and attribute-wise heuristic choice models (intertemporal choice heuristic, dual reasoning and implicit framework theory, trade-off model) captured the reward-specific discounting behavior. Contrary to our hypothesis of different strategies for different rewards, we observed comparable discounting behavior for money and food (i.e., exponential discounting). Higher k values for food discounting suggest that individuals decide more impulsive if confronted with food. The fMRI revealed that money discounting was associated with enhanced activity in the right dorsolateral prefrontal cortex, involved in executive control; the right dorsal striatum, associated with reward processing; and the left hippocampus, involved in memory encoding/retrieval. Food discounting, instead, was associated with higher activity in the left temporoparietal junction suggesting social reinforcement of food decisions. Although our findings do not confirm our hypothesis of different discounting strategies for different reward types, they are in line with the notion that reward types have a significant influence on impulsivity with primary rewards leading to more impulsive choices.

Health-Related Quality of Life after Combined External Beam and Either High Dose Rate (HDR) or Low Dose Rate (LDR) Brachytherapy: Does the Rectal Dose from the LDR Brachytherapy Make a Difference?

PURPOSE/OBJECTIVE(S)

The recently reported randomized Phase III trial comparing health related quality of life (HRQOL) after combined external beam radiation therapy (EBRT) and either HDR or LDR brachytherapy (BT) found a significant decline in the EPIC Bowel domain HRQOL score at 24- 48 months after treatment in the LDR arm of the trial. As all patients in the trial received the same EBRT dose, and HDR rectal dose was strictly controlled to be <9.5 Gy to 1cc of rectal wall (RD1cc), we investigated whether the variable rectal dose from the LDR component of treatment was related to the decline in Bowel HRQOL for these patients.

MATERIALS/METHODS

A total of 195 men with upper tier intermediate or high-risk prostate cancer were assigned by a random number generator to receive either an HDR (15 Gy, n = 108) or LDR (110Gy, n = 87) brachytherapy boost combined with 46Gy/23 fractions EBRT. All LDR patients had 1 month post implant quality assurance using CT-MRI fusion. The Expanded Prostate Cancer Composite (EPIC) questionnaire was used to evaluate HRQOL at baseline, q3 mo for 1 year, q6mo for 3 yr and then annually. A multivariate linear regression model was used to investigate the dose-response relationship between EPIC bowel domain score at 24- 48 months and RD1cc.

RESULTS

With a median follow up of 48 months, the previous analysis confirmed the expected time course of acute bowel/urinary symptoms, with LDR showing more prolonged decline in HRQOL bowel domain at 3 and 6 months, but equivalence to HDR by 12 months. HRQOL urinary domain remained equivalent from 12-60 mo. The decline in the HRQOL bowel domain observed for LDR patients from 24-48 mo was analyzed for the 79 patients with sufficient data. The mean baseline HRQOL bowel domain score was 92 and fell on average to 85 at 24-48 mo. Mean RD1cc for the LDR patients was 82Gy (SD 22 Gy), with a maximum value of 129 Gy. In this range of rectal doses, a 20Gy increase in RD1cc, was associated on average with a 1.5-point decrease in EPIC HRQOL bowel domain score (p = 0.21).

CONCLUSION

The rectal dose received by the LDR patients showed a non-significant dose-response with the EPIC Bowel domain HRQOL score. This confirms the accepted rectal dose constraints for LDR brachytherapy but does not explain the observed decline in bowel scores from 24-48 months.

Evidence of Antineutrinos from Distant Reactors Using Pure Water at SNO

The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240 km away in Ontario, Canada. This analysis uses events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5σ.

The feasibility and effectiveness of a novel online mental health literacy course in supporting university student mental health: a pilot study

BACKGROUND

There is a need for effective universal approaches to promote and support university student mental health that are scalable and sustainable. In this pilot study we assess the feasibility and acceptability of a fully-digitalized, comprehensive mental health literacy course co-created with and tailored to the needs of undergraduate students. We also explore preliminary associations with mental health and positive behaviour change.

METHODS

An accredited online mental health literacy course was developed using state-of-the-art pedagogical principles and a reverse mentorship approach. The course was offered as an interdisciplinary undergraduate elective. Students completed an online survey before and after the 12-week course that collected demographic information and assessed mental health knowledge, emotional self-awareness, mental health, stigma, and health-related behaviors using validated measures. Dependent group t-tests were used to compare pre- and post-course levels of knowledge, mental health, sleep quality and substance use. Mental health outcomes of students who completed the course were compared to an age and sex-matched sample of students not enrolled in the course and who completed the same survey measures over the same academic year. Multivariable linear regression was used to examine the effect of course participation on outcomes at follow-up.

RESULTS

The course had good uptake and was positively reviewed by participants. Specifically, students found the course engaging, relevant, and applicable, and agreed they would recommend it to their peers. Among course participants there was improvement in mental health knowledge (p < 0.001) and emotional self-awareness (p = 0.02) at course completion. Compared to the matched comparison group, taking the course was associated with reduced alcohol (β = - 0.41, p = 0.01) and cannabis use (β = - 0.35, p = 0.03), and improved sleep quality (β = 1.56, p = 0.09) at the end of the term.

CONCLUSIONS

Findings suggest that delivering mental health literacy as an online accredited course may be an acceptable and effective way of promoting university student mental health through improved knowledge, emotional self-awareness, and healthy lifestyle choices. As the course is expanded to larger and more diverse student cohorts we will be able to further examine the short and long-term effectiveness of the course in supporting student mental health and the underlying mechanisms.

Shear viscosity at finite baryon densities

We use the excluded volume Hadron Resonance Gas (HRG) model with the most up-to-date hadron list to calculate ηT/w at low temperatures and at finite baryon densities ρB. This ηT/w is then matched to a QCD-based shear viscosity calculation of the QGP for different profiles of ηT/w across T,μB including cross-over and critical point transitions. When compared to ideal hydrodynamic trajectories across T,μB, we find that the ηT/w(T,μB) profiles would require initial conditions at much larger baryon density to reach the same freeze-out point.

Proactive Construction of an Annotated Imaging Database for Artificial Intelligence Training

Artificial intelligence (AI) holds much promise for enabling highly desired imaging diagnostics improvements. One of the most limiting bottlenecks for the development of useful clinical-grade AI models is the lack of training data. One aspect is the large amount of cases needed and another is the necessity of high-quality ground truth annotation. The aim of the project was to establish and describe the construction of a database with substantial amounts of detail-annotated oncology imaging data from pathology and radiology. A specific objective was to be proactive, that is, to support undefined subsequent AI training across a wide range of tasks, such as detection, quantification, segmentation, and classification, which puts particular focus on the quality and generality of the annotations. The main outcome of this project was the database as such, with a collection of labeled image data from breast, ovary, skin, colon, skeleton, and liver. In addition, this effort also served as an exploration of best practices for further scalability of high-quality image collections, and a main contribution of the study was generic lessons learned regarding how to successfully organize efforts to construct medical imaging databases for AI training, summarized as eight guiding principles covering team, process, and execution aspects.

Receipt of Next-generation Genomic Sequencing among Patients with Metastatic Colorectal Cancer (mCRC) in a Real-World Cohort

Purpose of the Study: Disparities in genomic precision medicine approaches, through molecular profiling or next- generation sequencing (NGS), by race/ethnicity, insurance, and poverty have been identified in lung cancer, but not mCRC. Our goal was to examine disparities in receipt of NGS in patients with mCRC. Methods: We used all-payer electronic health record (EHR)-derived de-identified data from the Flatiron Health database generated from routine clinical care across the United States. Our study population included 26,524 patients with mCRC during the years 2013–2020. In addition to date of NGS testing, the FH-EHR data include demographics (age, sex, and race/ethnicity), payer type, and Eastern Cooperative Oncology Group (ECOG) performance status. We conducted descriptive analyses and multivariable logistic regression analysis to identify correlates of receipt of NGS within 6 months of metastatic diagnosis. Results: Among the 26,524 people with mCRC, 45% (n = 11,946) were women, 48% (n = 12,732) had a Commercial Health Plan, and the majority were seen in a community practice (92%) vs academic hospitals. Over 70% of the patients were White, 12% Black or African-American (AA), and 14% Other. Thirty-three percent (n = 8,821) of patients had documentation in the EHR of having received NGS. After simultaneously adjusting for other factors in the model, older age (ORper year increase: 0.97, 95% CI: 0.96–0.98) and Black/AA race (OR: 0.74, 95% CI: 0.68–0.81), compared to White, was associated with lower odds of receiving NGS testing. Conversely, female sex, better ECOG performance status, later calendar year, being seen in an academic practice, and having a Commercial Health Plan were associated with greater odds of receiving NGS. Conclusions: Our findings indicate that NGS is not received uniformly by all patients with mCRC. Future analyses will incorporate receipt of individual molecular biomarker tests, as recommended by professional societies, as well as their results (e.g., KRAS, NRAS, BRAF, MMR/MSI), treatment information, and survival.

Clinical profiles and incident heart failure in cardiomyopathies: a population-based linked electronic health record cohort study

Background

Cardiomyopathies frequently cause heart failure (HF), however their prevalence in the general population and the natural history of incident HF across the spectrum of cardiomyopathy phenotypes is poorly understood. Improved understanding will help guide rational selection of diagnostic tests and accelerate the recognition of underlying causes of HF.

Purpose

To estimate the prevalence of cardiomyopathies using electronic health records; to compare clinical characteristics between patients with cardiomyopathy phenotypes; and to describe the temporal relationship between diagnosis of cardiomyopathy and incident HF.

Methods

A population-based cohort of patients with cardiomyopathy (n=4058) was provided by the UK Clinical Practice Research Datalink (CPRD) from a denominator sample of ∼9 million individuals. Patients were phenotyped into groups according to ESC criteria: hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), arrhythmogenic right ventricular cardiomyopathy (ARVC) and restrictive cardiomyopathy (RCM). An additional group of transthyretin amyloid cardiomyopathy (ATTR-CM) was reported separately. Point prevalence was estimated for each cardiomyopathy subtype and clinical characteristics defined. An index date at first diagnosis of HF was determined for each patient and the time from/to first diagnosis of cardiomyopathy calculated relative to the index date and presented graphically.

Results

DCM was the most common cardiomyopathy phenotype among women and men with 3.4 and 7.7 cases per 10,000 population, respectively. The 2-fold increase in prevalence among men was consistent across DCM, HCM and RCM; the reverse trend was observed for ARVC which was found in 2.3 per 10,000 women and 1.1 per 10,000 men. At the time of first diagnosis of cardiomyopathy, most patients with ATTR-CM (73.5%), DCM (71.0%) and RCM (71.3%) had pre-existing HF though this proportion fell to 41.0% in ARVC and 31.0% in HCM. In relation to incident HF, a diagnosis of HCM and DCM were recorded earliest at a mean −2.2 years (SE 0.2) and −0.6 years (SE 0.1), respectively. We observed a clustering of diagnoses of RCM (mean −0.2 years, SE 0.4) and ARVC (mean 0.1 years, SE 0.1) around the time of onset of heart failure, whereas a diagnosis of ATTR-CM was first recorded at a mean of 0.9 years (SE 0.2) following the onset of heart failure.

Conclusions

Most diagnoses of ATTR-CM, DCM and RCM were preceded by clinical expression of HF whereas most people with ARVC or HCM developed HF after their cardiomyopathy diagnosis. Our findings in ARVC and HCM suggest a more indolent course with respect to cardiac function or better recognition in an asymptomatic phase. The clustering of a diagnosis of heart failure around the time of diagnosis of cardiomyopathy highlights a need for greater awareness of specific aetiologies of heart failure in routine practice and suggests opportunities for presymptomatic or earlier diagnosis.

Temporality of HF in cardiomyopathies

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Pfizer

Hypertrophic cardiomyopathy MYH7 mutation R723G alters mRNA secondary structure

Point mutation R723G in the MYH7 gene causes hypertrophic cardiomyopathy (HCM). Heterozygous patients with this mutation exhibit a comparable allelic imbalance of the MYH7 gene. On average 67% of the total MYH7 mRNA are derived from the MYH7^R723G-allele and 33% from the MYH7^WT allele. Mechanisms underlying mRNA allelic imbalance are largely unknown. We suggest that a different mRNA lifetime of the alleles may cause the allelic drift in R723G patients. A potent regulator of mRNA lifetime is its secondary structure. To test for alterations in the MYH7^R723G mRNA structure we used selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) analysis. We show significantly different SHAPE reactivity of wild-type and MYH7^R723G RNA, which is in accordance with bioinformatically predicted structures. Thus, we provide the first experimental evidence for mRNA secondary structure alterations by the HCM point mutation. We assume that this may result in a prolonged lifetime of MYH7^R723G mRNA in vivo and subsequently in the determined allelic imbalance.

P909 Diagnostic evaluation of rheumatic heart disease in aborigonal population

Background

Among Indigenous Australians, rates of Acute Rheumatic Fever (ARF) continue to be among the highest in the world. Diagnosis remains a clinical decision based on identification of major and minor manifestations of the illness. Treatment involves lengthy prophylaxis and should continue for a minimum of 10 years.

ARF can cause permanent damage to the heart known as rheumatic heart disease (RHD).

We therefore utilised echocardiography as a diagnostic tool incorporating Tissue Quantification Backscatter expressed in decibels (dB) and global LV work efficiency estimated from left ventricle (LV) pressure-strain loops to identify rheumatic changes of the Mitral Valve and help improve early diagnosis of RHD.

Method

Data from patients with suspected RHD (n = 14), and age matched controls (n = 10) underwent Mitral Valve Backscatter Analysis (MVBS). MVBS was expressed as a ratio % (MVBS ratio %) by dividing the average MVBS and the average blood pool value expressed in decibels (dB). Furthermore LV function was utilised via 2D longitudinal strain and indices of myocardial work were derived.

Result

MVBS ratio % was significantly higher in the control group as compared to the RHD group (p = 0.001) (fig1). Of the RHD group echocardiography parameters showed there were no significant mitral valve stenosis or regurgitation. Correlates of LV function included: Global work Index (GWI), Global longitudinal Strain (GLS) and Global work efficiency (GWE). Of the above correlates the control group showed Backscatter vs GLS (r= -0.89, p = 0.001), the RHD group: Backscatter vs GLS (r = 0.52. p = 0.12). Within the RHD group the ratio vs GWE (r= 0.57, p = 0.09) these results showed a trend to significance.

Conclusions

Currently diagnosis of RHD remains a clinical decision based on the identification of major and minor manifestations. In addition treatment involves prophylaxis injections for a minimum of ten years. Of this group there were no significant echocardiography changes, rather clinical manifestation to derive RHD.

This study shows that calibrated MVBS ratio % and determinants of myocardial work may be a promising quantitative tool to detect early manifestation of RHD potentially aiding an early treatment plan and thus reducing the clinical burden of monthly penicillin injections for a ten year period.

Abstract P909 Figure. RHD and Myocardial correlates

Liquid Chromatographic Determination of Maleic Hydrazide in Technical and Formulated Products: Collaborative Study

Fourteen collaborating laboratories assayed maleic hydrazide (MH), 6-hydroxypyridazin-3(2H)-one, in technical and formulated products by reversed-phase liquid chromatography (LC) with sulfanilic acid as an internal standard. The active MH in the samples (6 lots) ranged from 16% (expressed as the potassium salt) to 98% (MH in the technical). A small amount of 1 M KOH was added to the technical MH and analytical standards to create the potassium salt of the analyte which is soluble in water. Test samples and standards were extracted with water containing the internal standard before analysis by LC on a C8 column with an ion-pairing eluting solution and UV detection at 254 nm. The concentration of MH was calculated by comparing the peak area response ratios of the analyte and the internal standard with those in the analytical standard solution. Eleven laboratories weighed each test sample twice with single analysis. Three laboratories weighed each sample once and made duplicate injections on the LC system. The data were analyzed using the 11 laboratories' results. A second data analysis was done including all laboratory results using a Youden pair approach, selecting one of 2 duplicate assay values randomly for each laboratory and sample. In the first data analysis, the repeatability standard deviation ranged from 0.07 to 1.39%; reproducibility standard deviation ranged from 0.22 to 1.39%. In the second data analysis (using all laboratory data), repeatability standard deviation ranged from 0.09 to 0.86%; reproducibility standard deviation ranged from 0.22 to 1.31%.

Complex regional pain syndrome: a narrative review for the practising clinician

Complex regional pain syndrome (CRPS) is a life-altering condition that usually affects the extremities after a trauma or nerve injury. The physiologic changes that occur as a result of the inciting injury are complex, as the name of the syndrome implies. The pain and disability associated with CRPS often lead to psychological co-morbidities that create a vicious cycle of pain, isolation, and depression. We review recent developments in the understanding of CRPS and advancements in management of this syndrome. Further research in targeting specific mechanisms involved in the pathophysiology of CRPS should lead to prevention of this condition.

Influence of impaired selective motor control on gait in children with cerebral palsy

PURPOSE

Spastic cerebral palsy (CP) is characterized by four neuromuscular deficits: weakness, short muscle-tendon unit, muscle spasticity and impaired selective motor control (SMC). We examined the influence of impaired SMC on gait in children with bilateral spastic CP. Delineating the influence of neuromuscular deficits on gait abnormalities can guide surgical and therapeutic interventions to reduce long-term debilitating effects of CP.

METHODS

The relationship between impaired SMC and gait was assessed using multivariate linear regression analysis of Selective Control Assessment of the Lower Extremity (SCALE) in relation to stance phase knee flexion and temporal-spatial gait parameters calculated using 3D kinematics for 57 children with bilateral spastic CP, ages seven to 11 years.

RESULTS

Mean SCALE values were 5.8 (0 to 10, sd 3.0) and 5.7 (0 to 10, sd 2.9) for right and left legs, respectively. Multivariate linear regression models, including right and left SCALE and height, significantly predicted right and left knee flexion at initial contact (R = 0.479, p = 0.003; R = 0.452, p = 0.007, respectively) and right and left knee flexion in midstance (R = 0.428, p = 0.013; R = 0.407, p = 0.022, respectively). The model significantly predicted right and left step length (R = 0.645, p = 0.000; R = 0.523, p = 0.001, respectively) and predicted gait velocity (R = 0.444, p = 0.008). The model including SCALE did not predict step width.

CONCLUSION

Results indicate impaired SMC predicts increased knee flexion at initial contact, and reduces step length and velocity. Understanding the influence of impaired SMC on gait can inform decisions regarding therapy and surgery, such as hamstring lengthening.

LEVEL OF EVIDENCE

Level II Retrospective Study.

Dietary factors and pediatric multiple sclerosis: A case-control study

BACKGROUND

The role of diet in multiple sclerosis (MS) is largely uncharacterized, particularly as it pertains to pediatric-onset disease.

OBJECTIVE

To determine the association between dietary factors and MS in children.

METHODS

Pediatric MS patients and controls were recruited from 16 US centers (MS or clinically isolated syndrome onset before age 18, <4 years from symptom onset and at least 2 silent lesions on magnetic resonance imaging). The validated Block Kids Food Screener questionnaire was administered 2011-2016. Chi-squared test compared categorical variables, Kruskal-Wallis test compared continuous variables, and multivariable logistic regression analysis was performed.

RESULTS

In total, 312 cases and 456 controls were included (mean ages 15.1 and 14.4 years). In unadjusted analyses, there was no difference in intake of fats, proteins, carbohydrates, sugars, fruits, or vegetables. Dietary iron was lower in cases ( p = 0.04), and cases were more likely to consume below recommended guidelines of iron (77.2% of cases vs 62.9% of controls, p < 0.001). In multivariable analysis, iron consumption below recommended guidelines was associated with MS (odds ratio = 1.80, p < 0.01).

CONCLUSION

Pediatric MS cases may be less likely to consume sufficient iron compared to controls, and this warrants broader study to characterize a temporal relationship. No other significant difference in intake of most dietary factors was found.

An Anatomic Index for the Severity of Ocular Injuries

Ocular injuries are a frequent cause of monocular blindness and cause disfigurement and discomfort. We developed a measure of severity for eye injuries using a multi-attribute utility (MAU) model. The severity index scoring was applied to eye injuries that presented at hospitals in Wisconsin, U.S.A. The resulting distribution of severities was compatible with that seen by general eye care physicians. A severity scale provides a means of comparing the severity of injuries from a wide variety of traumatic sources (e.g. automobile crashes, combat injuries, occupational accidents, etc.) and is useful in evaluating preventive and public health measurements.