DNAJB1-PRKACA fusion neoantigens elicit rare endogenous T cell responses that potentiate cell therapy for fibrolamellar carcinoma

Fibrolamellar carcinoma (FLC) is a liver tumor with a high mortality burden and few treatment options. A promising therapeutic vulnerability in FLC is its driver mutation, a conserved DNAJB1-PRKACA gene fusion that could be an ideal target neoantigen for immunotherapy. In this study, we aim to define endogenous CD8 T cell responses to this fusion in FLC patients and evaluate fusion-specific T cell receptors (TCRs) for use in cellular immunotherapies. We observe that fusion-specific CD8 T cells are rare and that FLC patient TCR repertoires lack large clusters of related TCR sequences characteristic of potent antigen-specific responses, potentially explaining why endogenous immune responses are insufficient to clear FLC tumors. Nevertheless, we define two functional fusion-specific TCRs, one of which has strong anti-tumor activity in vivo. Together, our results provide insights into the fragmented nature of neoantigen-specific repertoires in humans and indicate routes for clinical development of successful immunotherapies for FLC.

Abstract 3570: Preservation of cellular heterogeneity in 3D and 2D cultures of pediatric solid tumors

Over the past 10 years, we have developed and characterized over 280 orthotopic patient derived xenografts (O-PDXs) representing 23 different types of pediatric solid tumors. The O-PDXs have undergone comprehensive characterization including genomics, transcriptomics, epigenomics, histologic review and analysis of cellular heterogeneity. All data, tissue samples and cryopreserved O-PDXs are freely available with no obligation to collaborate through the Childhood Solid Tumor Network (CSTN) at www.stjude.org/CSTN/. While these in vivo models are useful for preclinical testing of drugs and immunotherapy, researchers are limited by throughput, expense and expertise. High throughput ex vivo culture systems that more faithfully recapitulate the cellular heterogeneity and arrested differentiation in the patient tumors are urgently needed to test new drug combinations. Solid tumor cell lines have undergone extensive selection and adaptation in culture, and most have lost the cellular heterogeneity found in patient tumors. In order to overcome this barrier in the field, we have developed a 3D-to-2D workflow. Previous attempts to produce 2D ex vivo cultures from patient tumors or O-PDXs have had limited success because most cells die upon initial plating, they are difficult to cryopreserve for future studies and they lose key cell populations found in the patient tumors. Our new workflow was designed to overcome two sources of stress when adapting patient tumors or O-PDXs to culture. The first source of stress is transitioning from the in vivo environment to ex vivo in culture medium. The second source of stress is the transition from extensive 3D cell-cell contacts in vivo to a more limited cell-cell contact ex vivo. To overcome these two sources of stress, we adapted cultures to 2D in a stepwise manner. First, we dissociate O-PDX tumors into single cell suspension and then rapidly re-aggregate them in 3D spheres for ex vivo culture. After the spheres have grown for 7 days, they are transitioned to 2D by seeding cells in culture dishes coated with extracellular matrix components. Importantly, the 3D and 2D cultures preserve the cellular heterogeneity of the O-PDX and patient tumor and they can be cryopreserved. When injected back into immunocompromised mice, they recapitulate the molecular and cellular features of the original tumors. We have shown that the 3D and 2D cultures can be genetically manipulated using lentiviral vectors and can be used for high-throughput drug screening. Matched 3D and 2D cryovials are now available to the international biomedical research community for rhabdomyosarcoma through the CSTN. Neuroblastoma, osteosarcoma, Ewing sarcoma and retinoblastoma are expected to be available in late 2023. We anticipate this will accelerate the testing of oncology drugs for pediatric solid tumors in response to the RACE act through the PIVOT program.

Citation Format: Justina D. McEvoy, Melody Allensworth, Mariajose Franco, Natalie McDonald, Brittney Gordon, Anand Patel, Elizabeth Stewart, Michael Dyer. Preservation of cellular heterogeneity in 3D and 2D cultures of pediatric solid tumors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3570.

Universal Precautions Plus: Physician-Directed Strategies for Improving Patient Health Literacy in the Emergency Department

Working on the frontlines with safety-net populations, emergency physicians are uniquely positioned to take on a greater role in addressing the current health literacy crisis and specific barriers that may exist. Here, we review the concept of universal health literacy precautions and explore the application of these universal precautions in conjunction with other patient-centered strategies. More specifically, to improve patient understanding and outcomes, emergency physicians can pair universal health literacy precautions with strategies including multiple learning techniques, dual-code theory, empowerment counseling, family buy-in, and hands-on practice. We provide two examples of emergency department encounters where this combined approach was used differently yet successfully and efficiently. Ultimately, we aim to highlight the value of emergency physicians being equipped with basic skills in health literacy educational strategies.

Predictors of long term tricuspid regurgitation after pulmonary valve replacement: a single center study on the cohort of significant preoperative tricuspid regurgitation

Background

Almost one-third of repaired tetralogy of Fallot (TOF) and pulmonary stenosis (PS) patients referred for pulmonary valve replacement (PVR) have at least moderate tricuspid regurgitation (TR). Predictors of long term TR in this population are not well defined and the role of Tricuspid Annuloplasty (TA) in addition to PVR in this setting is controversial.

Purpose

Patients with preoperative severe TR or moderate TR with dilated tricuspid annulus (>40mm) undergo TA at the time of PVR as per protocol in our instititution. The aim of this observational study was to evaluate the long term results of this approach and to identify predictors of significant TR at the end of follow-up.

Material and methods

We retrospectively reviewed 35 repaired TOF and PS patients who underwent surgical PVR with (n=17, group 1) or without (n=18, group 2) TA in a single tertiary hospital between June-2009 and June-2021. Pre- and postoperative echocardiographic and cardiac magnetic resonance data were assessed for TR severity and right ventricle size and systolic function. Baseline and clinical follow up data were collected. Uni- and multivariable tests were used to analyze predictors of at least moderate TR after PVR.

Results

Mean age at PVR and baseline image parameters were comparable between groups, except for TR grade (p 0.006), tricuspid annulus size (p 0.018) and right ventricle outflow tract diameter (p 0.04) which were greater in group 1. TA did not confer and increased risk of surgical and peroperative complications. Intensive care unit (p 0.94) and total hospital admission days (p 0.59) did not differ among groups. At one year, TR grade significantly improved regardless of TA. At the end of follow-up (5.29±2.9 years), the degree of TR increased in both groups with no differences between groups (p 0.38) (see table 1). In univariable analysis, two independent predictors of at least moderate TR at end of follow-up were identified; mixed TR mechanism (OR 12.5, p 0.006) and severe preoperative TR grade (OR 10.21, p 0.003). Mixed TR mechanism (OR 15.78, p 0.01) and a right ventricle ejection fraction below 45% (OR 1.47, p 0.01) were identified as risk factors of significant TR in multivariable analysis (see Table 2).

Conclusions

TA seems a reasonable approach at the time of PVR in patients with severe TR or moderate TR with dilated annulus. Mixed TR mechanism and a worse right ventricular function have been identified as independent predictors factors of long term significant postoperative TR in our study cohort.

Funding Acknowledgement

Type of funding sources: None.

The myokine Fibcd1 is an endogenous determinant of myofiber size and mitigates cancer-induced myofiber atrophy

Decline in skeletal muscle cell size (myofiber atrophy) is a key feature of cancer-induced wasting (cachexia). In particular, atrophy of the diaphragm, the major muscle responsible for breathing, is an important determinant of cancer-associated mortality. However, therapeutic options are limited. Here, we have used Drosophila transgenic screening to identify muscle-secreted factors (myokines) that act as paracrine regulators of myofiber growth. Subsequent testing in mouse myotubes revealed that mouse Fibcd1 is an evolutionary-conserved myokine that preserves myofiber size via ERK signaling. Local administration of recombinant Fibcd1 (rFibcd1) ameliorates cachexia-induced myofiber atrophy in the diaphragm of mice bearing patient-derived melanoma xenografts and LLC carcinomas. Moreover, rFibcd1 impedes cachexia-associated transcriptional changes in the diaphragm. Fibcd1-induced signaling appears to be muscle selective because rFibcd1 increases ERK activity in myotubes but not in several cancer cell lines tested. We propose that rFibcd1 may help reinstate myofiber size in the diaphragm of patients with cancer cachexia.

The myogenesis program drives clonal selection and drug resistance in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a pediatric cancer with features of skeletal muscle; patients with unresectable or metastatic RMS fare poorly due to high rates of disease recurrence. Here, we use single-cell and single-nucleus RNA sequencing to show that RMS tumors recapitulate the spectrum of embryonal myogenesis. Using matched patient samples from a clinical trial and orthotopic patient-derived xenografts (O-PDXs), we show that chemotherapy eliminates the most proliferative component with features of myoblasts within embryonal RMS; after treatment, the immature population with features of paraxial mesoderm expands to reconstitute the developmental hierarchy of the original tumor. We discovered that this paraxial mesoderm population is dependent on EGFR signaling and is sensitive to EGFR inhibitors. Taken together, these data serve as a proof of concept that targeting each developmental state in embryonal RMS is an effective strategy for improving outcomes by preventing disease recurrence.

The chemotherapeutic CX-5461 primarily targets TOP2B and exhibits selective activity in high-risk neuroblastoma

Survival in high-risk pediatric neuroblastoma has remained around 50% for the last 20 years, with immunotherapies and targeted therapies having had minimal impact. Here, we identify the small molecule CX-5461 as selectively cytotoxic to high-risk neuroblastoma and synergistic with low picomolar concentrations of topoisomerase I inhibitors in improving survival in vivo in orthotopic patient-derived xenograft neuroblastoma mouse models. CX-5461 recently progressed through phase I clinical trial as a first-in-human inhibitor of RNA-POL I. However, we also use a comprehensive panel of in vitro and in vivo assays to demonstrate that CX-5461 has been mischaracterized and that its primary target at pharmacologically relevant concentrations, is in fact topoisomerase II beta (TOP2B), not RNA-POL I. This is important because existing clinically approved chemotherapeutics have well-documented off-target interactions with TOP2B, which have previously been shown to cause both therapy-induced leukemia and cardiotoxicity-often-fatal adverse events, which can emerge several years after treatment. Thus, while we show that combination therapies involving CX-5461 have promising anti-tumor activity in vivo in neuroblastoma, our identification of TOP2B as the primary target of CX-5461 indicates unexpected safety concerns that should be examined in ongoing phase II clinical trials in adult patients before pursuing clinical studies in children.

Frequency and outcomes of gastrointestinal symptoms in patients with Corona Virus Disease-19

OBJECTIVES

To characterize the frequency and association of gastrointestinal (GI) symptoms with outcomes in patients with corona virus disease 2019  (COVID-19) admitted to the hospital.

METHODS

Records were retrospectively collected from patients admitted to a tertiary care center in Washington, D.C., with confirmed COVID-19 from March 15, 2020  to July 15, 2020. After adjusting for clinical demographics and comorbidities, multivariate logistic regression analysis was performed.

RESULTS

The most common  presenting symptoms of COVID-19 in patients that were admitted to the hospital were cough (38.4%), shortness of breath (37.5%), and fever (34.3%), followed by GI symptoms in 25.9% of patients. The most common GI symptom was diarrhea (12.8%) followed by nausea or vomiting (10.5%), decreased appetite (9.3%), and abdominal pain (3.8%). Patients with diarrhea were more likely to die (odds ratio [OR] 2.750; p = 0.006; confidence interval [CI] 1.329-5.688), be admitted to the intensive care unit (ICU) (OR 2.242; p = 0.019; CI 1.139-4.413), and be intubated (OR 3.155; p = 0.002; CI 1.535-6.487). Additional outcomes analyzed were need for vasopressors, presence of shock, and acute kidney injury. Patients with  diarrhea  were 2.738 (p = 0.007; CI 1.325-5.658), 2.467 (p = 0.013; CI 1.209-5.035), and 2.694 (p = 0.007; CI 1.305-5.561) times more likely to experience these outcomes, respectively.

CONCLUSIONS

Screening questions should be expanded to include common GI symptoms in patients with COVID-19. Health care providers should note whether their patient is presenting with diarrhea due to the potential implications on disease severity and outcomes.

Clinical features and outcomes of adult patients with single ventricle physiology not undergoing Fontan repair

Background

Adult patients with single ventricle (SV) physiology who had not undergone Fontan palliation are uncommon. Little is known about their clinical features and outcomes.

Objective

This study aims to describe the clinical features, cardiovascular outcomes and long-term survival of patients with SV physiology without Fontan palliation.

Methods

Data were collected retrospectively from SV physiology patients followed in adult congenital heart disease (ACHD) units of five tertiary referral centers. None of them had Fontan palliation. Baseline data were recorded on the first visit at ACHD unit. Death was considered as main endpoint. Other outcomes such as atrial or ventricular arrhythmias, endocarditis, ICD or pacemaker implantation, admission for heart failure and heart transplant were also collected and analyzed. Association between clinical/analytical baseline variables and death was also evaluated by univariate Cox regression.

Results

128 patients were included. On the first visit, mean age was 32.3±10.9 years, being the most common defect double inlet left ventricle (63p, 49.2%). The single ventricle had left morphology in 106 cases (82.8%). At baseline mean heaemglobin was 19.1±2.8 g/dl, mean O2 Sat 83±6.9% and 46 patients (36%) had a NYHA status III or IV. 4 different groups were found: a) Unrestricted pulmonary flow with Eisenmenger physiology (24p, 18.8%); b) Restricted forward pulmonary flow with or without pulmonary banding (46p, 35.9%); c) Aortopulmonary shunts as a source of pulmonary flow (20p, 15.5%) and d) cavopulmonary shunt (Glenn) as a definitive palliation (38p, 29.7%). After 7.3±4.1 years follow-up, mortality was 22.7% (29 patients), being sudden death (9p, 7%) the most frequent cause. Survival rate at 5 and 10 years of follow-up were 85% and 76% respectively (Figure 1). About of the rest of the outcomes, highlighting a high rate of atrial tachycardia (38.3%), admission for heart failure (23.4%), stroke (17.2%), endocarditis (9.4%), pacemaker/ICD implantation (11.8%). Baseline variables associated with higher mortality were: older age (HR=1.1 [1.004–1–087]); NYHA III or IV (HR=5.5 [2.4–12.4]); thrombocytopenia (HR=1.01 [1.001–1.003]); anticoagulant treatment (HR=2.6 [1.7–3.9]); glomerular filtration rate below 60 ml/min (HR=3.77 [1.5–9.6]); QRS width (HR=1.03 [1.01–1.05]); atrial arrhythmias (HR=3.1 [1.5–6.5]); moderate or severe AV valve regurgitation (HR=1.5 [1.15–1.97]) and ventricular ejection fraction (HR=0.94 [0.91-0.97]).

Conclusions

Adults survivors with SV physiology without Fontan palliation have a high mortality and frequently suffer from serious cardiovascular events. Several clinical (NYHA status, previous atrial arrhythmias, anticoagulant treatment), analytical (renal function, thrombocytopenia), ECG (QRS width) and echocardiography (AV valve regurgitation and EF) factors can identify patients at higher risk of death.

Figure 1. Survival curve

Funding Acknowledgement

Type of funding source: None

Abstract 6149: An innovative integrated cloud-based data portal for orthotopic patient-derived xenografts (O-PDX) available through the Childhood Solid Tumor Network (CSTN)

Despite making significant advances over the past 25 years in our understanding of the most common adult solid tumors, much less is known about childhood solid tumors. We have previously described a protocol to produce orthotopic patient-derived xenografts (O-PDX) at diagnosis, recurrence and autopsy. These O-PDX models provide both in vivo and in vitro systems to study mechanisms of disease origin, tumor progression and preclinical testing. Here, we present an innovative cloud-based all-in-one data portal to explore various biological features of these pediatric O-PDX models. The vast diversity of the collected childhood solid tumors is represented in 166 O-PDX models, consisting of 21 diagnoses including Neuroblastoma, Osteosarcoma, Rhabdomyosarcoma, and a large number of rare solid tumors including Ewing Sarcoma, Desmoplastic Small Cell Round Tumor, Fibrosarcoma, High Grade Sarcoma, Liposarcoma, Retinoblastoma, Rhabdoid Tumor and Synovial Sarcoma. The O-PDX models have been characterized and compared to the original patient tumor using various methods and assays including histology, electron microscopy, short tandem repeat DNA profiling, chemical compound screening as well as genomic sequencing (whole genome sequencing, whole exome sequencing, and RNA Sequencing) and clonal analysis to determine the clonal population in the O-PDX. Somatic genetic mutations as well as clonal architecture is retained in the majority of O-PDX tumors. The data on O-PDX models can now be visualized and compared in our web-based CSTN data portal on St Jude Cloud (www.stjude.cloud). The user-friendly interface allows both gene and sample level search and visualization. For genomics variations, the presence or absence of a particular variant can be observed through interactive heatmaps. In addition to genomic and transcriptomic profiles, some of these models have extensive epigenomic and proteomic profiling which are integrated into the portal. We have also included chemical sensitivity heatmaps and dose response curves for common oncology drugs using primary cultures of the O-PDXs and cell lines. Importantly, the raw genomics sequencing data is also available from St Jude Cloud, following a straightforward application and approval process for access. In summary, the integration of data from multi-omics and beyond at the CSTN data portal provides a rich resource for both academic and industrial research community to find the appropriate models to advance the knowledge and therapeutic solutions to the catastrophic childhood solid tumors. *co-first #co-corresponding

Citation Format: Asa Karlstrom, Ti-Cheng Chang, Darrell Gentry, Xin Zhou, Elizabeth Stewart, Brittney Gordon, Sara M. Federico, Rachel Brennan, Michael R. Clay, Sharon Frase, Armita Bahrami, Xiang Chen, Anang A. Shelat, Nathaniel R. Twarog, Daniel Alford, Anthony Woodard, Edgar Sioson, Irina McGuire, Cynthia Williams, Nedra Robison, Brandon McMahan, Ashok K. Boddu, Swapnali Mohite, Kirby Birch, Clay McLeod, Michael Rusch, Alberto Pappo, Keith Perry, Gang Wu, Ed Suh, Michael A. Dyer. An innovative integrated cloud-based data portal for orthotopic patient-derived xenografts (O-PDX) available through the Childhood Solid Tumor Network (CSTN) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6149.

Abstract 6155: Pediatric rhabdomyosarcomas recapitulate the transcriptomic and epigenomic development of skeletal myogenesis

Rhabdomyosarcoma (RMS), is a pediatric tumor that histologically mimics developing skeletal muscle. Importantly, RMS tumors feature heterogeneous expression of the skeletal muscle transcription factor myogenin (MYOG). However, the degree by which RMS tumors model the development of normal skeletal muscle remains unclear. Here, we have utilized droplet-based single-cell RNA-sequencing (scRNA-seq) of 158,070 cells or nuclei isolated from 20 patient RMS tumors (14 embryonal RMS [ERMS], 6 alveolar RMS [ARMS]). Surprisingly, we found that cells from ERMS tumors recapitulate the entire developmental hierarchy of muscle development, with a subset of cells expressing the presomitic mesoderm homeobox gene, MEOX2. In contrast, cells from ARMS tumors were more narrowly restricted to expression of the myoblast- and myocyte-specific transcription factors MYF5 and MYOG. We extended this observation using a developmental indexing approach that leverages single-nuclear transcriptomic data from the Mouse Organogenesis Cell Atlas. By identifying latent cellular states within developing non-malignant embryonal muscle and projecting those latent states onto malignant cells, our developmental index estimates the equivalent myogenic developmental state of each individual malignant cell. ERMS tumors consistently displayed a broad diversity of development indices, even in relapsed tumors; alveolar RMS tumors, however, were restricted to late myoblast and myocyte developmental states. We applied our developmental index to an additional 310,937 cells isolated from 19 orthotopic patient-derived xenografts (O-PDXs), which preserved the developmental diversity of their originating tumor. Next, we used lentiviral barcoding with a high-complexity library to demonstrate that developmental states are interrelated rather than isolated subclones. Additionally, we transduced O-PDX cell suspensions with RFP-encoding retrovirus to lineage trace proliferative cells to show that ERMS tumors transition from immature to mature myogenic states in a unidirectional manner. Finally, we utilized single-cell assay of transposase-accessible chromatin with sequencing (scATAC-seq) in combination with scRNA-seq to show that core regulatory circuit superenhancer accessibility is heterogeneously specific to developmental state within both ERMS and ARMS. Taken together, our findings reveal that pediatric RMS consist of transformed cells that recapitulate the transcriptomic and epigenomic diversity of embryonic muscle.

Citation Format: Anand G. Patel, Xiang Chen, Michael Clay, Brittney Gordon, Jim Houston, Asa Karlstrom, Jackie Norrie, Elizabeth Stewart, Michael Dyer. Pediatric rhabdomyosarcomas recapitulate the transcriptomic and epigenomic development of skeletal myogenesis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6155.

Tau positron emission tomography imaging in C9orf72 repeat expansion carriers

BACKGROUND AND PURPOSE

AV-1451 (18 F-AV-1451, flortaucipir) positron emission tomography was performed in C9orf72 expansion carriers to assess tau accumulation and disease manifestation.

METHODS

Nine clinically characterized C9orf72 expansion carriers and 18 age- and gender- matched cognitively normal individuals were psychometrically evaluated and underwent tau positron emission tomography imaging. The regional AV-1451 standard uptake value ratios from multiple brain regions were analyzed. Spearman correlation was performed to relate the AV-1451 standard uptake value ratio to clinical, psychometric and cerebrospinal fluid measures.

RESULTS

C9orf72 expansion carriers had increased AV-1451 binding in the entorhinal cortex compared to controls. Primary age-related tauopathy was observed postmortem in one patient. AV-1451 uptake did not correlate with clinical severity, disease duration, psychometric performance or cerebrospinal fluid markers.

CONCLUSION

C9orf72 expansion carriers exhibited increased AV-1451 uptake in entorhinal cortex compared to cognitively normal controls, suggesting a propensity for primary age-related tauopathy. However, AV-1451 accumulation was not associated with psychometric performance in our cohort.

Identification of Therapeutic Targets in Rhabdomyosarcoma through Integrated Genomic, Epigenomic, and Proteomic Analyses

Personalized cancer therapy targeting somatic mutations in patient tumors is increasingly being incorporated into practice. Other therapeutic vulnerabilities resulting from changes in gene expression due to tumor specific epigenetic perturbations are progressively being recognized. These genomic and epigenomic changes are ultimately manifest in the tumor proteome and phosphoproteome. We integrated transcriptomic, epigenomic, and proteomic/phosphoproteomic data to elucidate the cellular origins and therapeutic vulnerabilities of rhabdomyosarcoma (RMS). We discovered that alveolar RMS occurs further along the developmental program than embryonal RMS. We also identified deregulation of the RAS/MEK/ERK/CDK4/6, G₂/M, and unfolded protein response pathways through our integrated analysis. Comprehensive preclinical testing revealed that targeting the WEE1 kinase in the G₂/M pathway is the most effective approach in vivo for high-risk RMS.

Hearing threshold shifts among military pilots of the Israeli Air Force

Background

Military aviators are potentially at risk for developing noise-induced hearing loss. Whether ambient aircraft noise exposure causes hearing deficit beyond the changes attributed to natural ageing is debated. The aim of this research was to assess changes in hearing thresholds of Israeli Air Force (IAF) pilots over 20 years of military service and identify potential risk factors for hearing loss.

Methods

A retrospective cohort analysis was conducted of pure-tone air conduction audiograms of pilots, from their recruitment at 18 years of age until the last documented medical check-up. Mean hearing thresholds were analysed in relation to age, total flight hours and aircraft platform. Comparisons were made to the hearing thresholds of air traffic controllers (ATCs) who were not exposed to the noise generated by aircraft while on duty.

Results

One hundred and sixty-three pilots were included, with flying platforms ranging from fighter jets (n=54), combat helicopters (n=27), transport helicopters (n=52) and transport aircraft (n=30). These were compared with the results from 17 ATCs. A marked notch in the frequency range of 4–6 kHz was demonstrated in the mean audiograms of all platforms pilots, progressing with ageing. Hearing threshold shifts in relation to measurements at recruitment were first noted at the age of 30 years, particularly at 4 kHz (mean shift of 2.97 dB, p=0.001). There was no statistical association between flying variables and hearing thresholds adjusted for age by logistic regression analysis.

Conclusions

The audiometric profile of IAF pilots has a pattern compatible with noise exposure, as reflected by characteristic noise notch. However, no flight variable was associated with deterioration of hearing thresholds, and no significant difference from non-flying controls (ATCs) was seen.

Effect of Microwave Heating on the Crystallization of Glutathione Tripeptide on Silver Nanoparticle Films

Effect of microwave heating on the crystallization of glutathione (GSH) tripeptide using the metal-assisted and microwave-accelerated evaporative crystallization (MA-MAEC) technique is reported. GSH crystals were grown from supersaturated solutions of GSH (300-500 mg/mL) on the iCrystal plates with silver nanoparticle films (SNFs) and without SNFs in three different microwave systems operating at 2.45 GHz: conventional (multimode, fixed power at 900W), industrial (monomode, variable power up to 1200 W), and the iCrystal system (monomode, variable power up to 100 W). The efficacy of the MA-MAEC technique, in terms of improvement in the crystallization time, crystal size and quality of GSH, was compared between the three microwave systems and the crystallization at room temperature (no microwave heating, a control experiment). Optical microscopy was used to visualize and quantify the growth of GSH crystals during and after microwave heating. Powder X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy data showed that GSH crystals had identical crystal structure to those grown at room temperature and microwave heating did not alter the chemical structure of GSH molecules during microwave heating, respectively. Using the MA-MAEC technique, the iCrystal system yielded high quality GSH crystals in a rapid manner.

Sex differences in the association between body mass index and hypertension - a cross-sectional study in 717 812 adolescents

In order to examine sex-specific differences in the association of body mass index (BMI) and hypertension, we conducted a retrospective, cross-sectional study of 717 812 (402 914 men and 314 898 women) Israeli Jewish adolescents aged 16.0-19.99 years medically screened for military service. A diagnosis of hypertension was established per history or if a mean of 10 separate blood pressure measurements exceeded 140/90, following an initial measurement higher than 140/90. Weight and height were measured. Prevalence of hypertension was 0.42% in men and 0.05% in women. In men, BMI was significantly associated with hypertension from the third decile (odds ratio [OR] 1.67, 1.06-2.65) up to the 10th decile (OR 30.17, 20.83-43.69). In women, we observed a significantly increased risk for hypertension in the ninth decile (OR 3.82, 1.42-10.22) and in the 10th decile (OR 18.92, 7.7-46.51), with no visible trend in lower deciles. BMI effects on hypertension prevalence are different in male and female adolescents.

De-crystallization of Uric Acid Crystals in Synovial Fluid Using Gold Colloids and Microwave Heating

In this study, we demonstrated a unique application of our Metal-Assisted and Microwave-Accelerated Evaporative Crystallization (MA-MAEC) technique for the de-crystallization of uric acid crystals, which causes gout in humans when monosodium urate crystals accumulate in the synovial fluid found in the joints of bones. Given the shortcomings of the existing treatments for gout, we investigated whether the MA-MAEC technique can offer an alternative solution to the treatment of gout. Our technique is based on the use of metal nanoparticles (i.e., gold colloids) with low microwave heating to accelerate the de-crystallization process. In this regard, we employed a two-step process; (i) crystallization of uric acid on glass slides, which act as a solid platform to mimic a bone, (ii) de-crystallization of uric acid crystals on glass slides with the addition of gold colloids and low power microwave heating, which act as “nano-bullets” when microwave heated in a solution. We observed that the size and number of the uric acid crystals were reduced by >60% within 10 minutes of low power microwave heating. In addition, the use of gold colloids without microwave heating (i.e. control experiment) did not result in the de-crystallization of the uric acid crystals, which proves the utility of our MA-MAEC technique in the de-crystallization of uric acid.

Targeting the DNA repair pathway in Ewing sarcoma

Ewing sarcoma (EWS) is a tumor of the bone and soft tissue that primarily affects adolescents and young adults. With current therapies, 70% of patients with localized disease survive, but patients with metastatic or recurrent disease have a poor outcome. We found that EWS cell lines are defective in DNA break repair and are sensitive to PARP inhibitors (PARPis). PARPi-induced cytotoxicity in EWS cells was 10- to 1,000-fold higher after administration of the DNA-damaging agents irinotecan or temozolomide. We developed an orthotopic EWS mouse model and performed pharmacokinetic and pharmacodynamic studies using three different PARPis that are in clinical development for pediatric cancer. Irinotecan administered on a low-dose, protracted schedule previously optimized for pediatric patients was an effective DNA-damaging agent when combined with PARPis; it was also better tolerated than combinations with temozolomide. Combining PARPis with irinotecan and temozolomide gave complete and durable responses in more than 80% of the mice.

Population-based trends in overweight and obesity: a comparative study of 2,148,342 Israeli male and female adolescents born 1950-1993

BACKGROUND

The epidemic of obesity has been identified as a major source of morbidity, not just in developed countries but globally, in adults as well as at younger ages.

OBJECTIVE

The aims of this study were to describe trends in obesity and overweight in Israeli adolescents and observe temporal changes and association by risk factors.

METHODS

The research analyzed records of 2,148,342 Jewish adolescents, over a span of 44 years and included data for individual body measurements, place of residence, area of origin and education levels. Body mass index (BMI) was measured by professionals, calculated and categorized as overweight or obesity according to age- and gender-specific BMI curves established in recent years. We processed the data in multinomial logistic regression model and calculated odds ratios for various risk factors.

RESULTS

Obesity and overweight are on the rise for male and female adolescents born from the mid-1960s onwards, and especially for men from the 1980s onwards. Risk factors for male adolescents include lower socioeconomic status, inferior education levels and Western origins (vs. Asian, African or Israeli origins). Risk modifiers for women were similar, except for African origins, which were associated with increased risk rather than decreased risk. Asian and Israeli origins were protective for both genders, and education was more strongly associated with obesity for women.

CONCLUSIONS

We recommend stronger preventive efforts directed at adolescents as a whole, and particularly vulnerable groups with lower education levels and poverty, or those with specific geographical origins. Gender disparities are evident and should be considered in these efforts and in further research.

Effects of 5-fluorouracil chemotherapy on fatigue: role of MCP-1

Chemotherapy has been known to cause severe side effects, including fatigue. While the mechanisms for chemotherapy induced fatigue (CIF) are likely to be multi-factorial in origin, it is thought that inflammation and anemia may play a role. The purpose of this study was to examine the effect of chemotherapy on fatigue in mice, and further, to begin to determine if inflammation and anemia may contribute to this response. For experiment 1, C57BL/6 mice were assigned to: vehicle (PBS), low (20 mg/kg), medium (40 mg/kg), or high (60 mg/kg) doses of 5-fluorouracil (5-FU). Voluntary physical activity (PA) was measured throughout the treatment period (day 1-5) as well as during the recovery period (day 6-14). In experiment 2, we examined the effects of 5-FU (60 mg/kg) on the inflammatory mediator MCP-1 and on markers of anemia (RBC, Hct and Hb). Finally, using MCP-1(-/-) mice we examined the role of MCP-1 on CIF (experiment 3). 5-FU reduced voluntary PA in a dose response manner (p<0.05). Plasma MCP-1 was increased following 5-FU treatment on both days 5 (p=0.10) and 14 (p<0.05). In addition, RBCs, Hct and Hb were reduced with 5-FU on days 5 and 14 (p<0.05). Both C57BL/6 and MCP-1(-/-) mice saw similar decrements in PA through the duration of the treatment period (days 1-5), however the MCP-1(-/-) mice recovered much earlier than wildtype mice. This study provides evidence of the dose response effect of a standard chemotherapy agent on fatigue and demonstrates a potential role of MCP-1 and presumably inflammation, and anemia.

Evaluation of the effect of TRU-016, an anti-CD37 directed SMIP in combination with other therapeutic drugs in models of non-Hodgkin's lymphoma

8571

Background: TRU-016, a single chain anti-CD37 Fc fusion molecule has been shown to display pro-apoptotic and Fc-dependent cellular cytotoxicity activities against primary CLL cells and NHL cell lines. The pro-apoptotic signal generated by TRU-016 binding to CD37 on CLL cells has been shown to be caspase-independent and distinct from the signal generated by many other therapeutics including rituximab. We have tested drug combinations using the mantle cell lymphoma line Rec-1 and diffuse large B-cell lymphoma line SU-DHL-6 in vitro and extended these results to in vivo settings using the follicular lymphoma cell line DOHH2 treated with the combination of TRU-016 and bendamustine. Methods: To determine TRU-016 interactions with the established therapeutics rituximab, doxorubicin, rapamycin, and bendamustine, drugs were tested alone or in combination with TRU-016 and the anti-proliferative effects on cell lines measured after 96 hours. Combination index analysis was performed for drug combinations over the 20–90% effect levels using the Calcusyn software package. To determine if in vitro synergy could be recapitulated in vivo, SCID mice were implanted with DOHH2 cells and therapeutic treatment was initiated when tumor volumes reached 200 mm3. Treatments consisted of TRU-016, bendamustine, or the combination of TRU-016 and bendamustine. Results: Combination index analyses determined that TRU-016 is synergistic with rituximab, bendamustine, or rapamycin and additive with doxorubicin in NHL models. In vivo results show that treatment with the combination of TRU-016 and bendamustine resulted in increased efficacy compared to the efficacy attained with the individual drugs. This demonstrates that the in vitro synergy results were extendable to a more complex in vivo disease model. Conclusions: TRU-016 in combination with rituximab, rapamycin, or bendamustine increases cell killing of NHL cells. Furthermore, the combination of TRU-016 and bendamustine displayed greater in vivo anti-tumor activity than either agent alone against a follicular lymphoma tumor model.

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Serum uric acid and brain ischemia in normal elderly adults

BACKGROUND

Uric acid (UA) has antioxidant properties yet when elevated is associated with vascular disease and stroke. Further, even high normal UA is associated with increased risk of mild cognitive dysfunction in elderly adults.

METHOD

In this cross-sectional, observational study, we examined the relationship between serum UA and aggregate volume of white matter hyperintense (WMH) signals observed on proton density and T2-weighted brain MR images in a community sample of 177 adults ages 20 to 92. Using logistic regression, we tested whether participants with UA concentrations in the highest quartile of the sample--but still normal--would have increased WMH volumes.

RESULTS

Compared with those with low to moderate levels, participants with high normal serum UA were more likely to fall in the highest quartile of WMH volume. The odds ratios (95% CIs) of increased WMH were 2.6 (1.2 to 5.4) for total, 2.5 (1.2 to 5.1) for periventricular, and 2.8 (1.4 to 5.9) for subcortical WMH volume. After controlling for age, sex, race, education, body mass, hypertension, and diabetes, the multivariate-adjusted odds of large total and subcortical WMH volumes remained elevated. Finally, high normal UA increased the odds of having excessive ischemic burden four- to fivefold in adults ages 60 and older.

CONCLUSIONS

These findings demonstrate that mildly elevated serum uric acid is associated with increased burden of cerebral ischemic pathology, particularly in older adults. We outline the potential pathogenesis of this association. A clinical trial of antihyperuricemic medication to treat or prevent chronic brain ischemia might be warranted.

The NCI pediatric central institutional review board (PedCIRB) initiative: Progress and impact

6632

NCI has developed a central IRB (PedCIRB) to review NCI-sponsored pediatric clinical trials conducted by the Children's Oncology Group (COG). COG comprises ∼200 U.S. medical institutions and protocol activation traditionally requires separate protocol review by each local IRB (LIRB) and, subsequently, a review of each protocol amendment and significant adverse event. The PedCIRB model seeks to increase patient protection by improving the expertise of protocol reviewers and making their review available to all PedCIRB participating institutions. The PedCIRB consists of experts in pediatric oncology, pediatric medicine, nursing, pharmacy, bioethics, biostatistics, as well as patient advocates and childhood cancer survivors. The PedCIRB model also eliminates redundant reviews, reduces administrative burdens on local COG investigators and LIRBs, and can accelerate the pace of local protocol activation, thus increasing the availability of clinical trials to children with cancer. The PedCIRB conducts a full board protocol review that is available via a confidential website to participating LIRBs. LIRBs can choose to perform a facilitated review, using PedCIRB materials, that focuses on local concerns, rather than a full LIRB protocol review. If the LIRB accepts the PedCIRB review, the PedCIRB becomes the IRB of record for that protocol and takes responsibility for the review of subsequent protocol amendments, adverse events and continuing reviews. Since starting in November 2004, the PedCIRB has reviewed 59 protocols. Initial reviews resulted in 44 approvals pending modification and 15 protocols being tabled for further information. The time from protocol submission to final approval by the PedCIRB has ranged from 3 to 28 weeks with an average time of 16.9 weeks during year one and 12.7 weeks during year two of the project. As of November 2006, 117 of a possible 197 U.S. COG institutions (59%) have signed on to the PedCIRB initiative and 70% of the participating institutions have conducted facilitated reviews (total 750) for the 30 protocols available on the PedCIRB website. The PedCIRB's influence on protocol development and patient accrual timelines will be discussed.

No significant financial relationships to disclose.