Buffering Mechanism in Aortic Arch Artery Formation and Congenital Heart Disease

BACKGROUND

The resiliency of embryonic development to genetic and environmental perturbations has been long appreciated; however, little is known about the mechanisms underlying the robustness of developmental processes. Aberrations resulting in neonatal lethality are exemplified by congenital heart disease arising from defective morphogenesis of pharyngeal arch arteries (PAAs) and their derivatives.

METHODS

Mouse genetics, lineage tracing, confocal microscopy, and quantitative image analyses were used to investigate mechanisms of PAA formation and repair.

RESULTS

The second heart field (SHF) gives rise to the PAA endothelium. Here, we show that the number of SHF-derived endothelial cells (ECs) is regulated by VEGFR2 (vascular endothelial growth factor receptor 2) and Tbx1. Remarkably, when the SHF-derived EC number is decreased, PAA development can be rescued by the compensatory endothelium. Blocking such compensatory response leads to embryonic demise. To determine the source of compensating ECs and mechanisms regulating their recruitment, we investigated 3-dimensional EC connectivity, EC fate, and gene expression. Our studies demonstrate that the expression of VEGFR2 by the SHF is required for the differentiation of SHF-derived cells into PAA ECs. The deletion of 1 VEGFR2 allele (VEGFR2SHF-HET) reduces SHF contribution to the PAA endothelium, while the deletion of both alleles (VEGFR2SHF-KO) abolishes it. The decrease in SHF-derived ECs in VEGFR2SHF-HET and VEGFR2SHF-KO embryos is complemented by the recruitment of ECs from the nearby veins. Compensatory ECs contribute to PAA derivatives, giving rise to the endothelium of the aortic arch and the ductus in VEGFR2SHF-KO mutants. Blocking the compensatory response in VEGFR2SHF-KO mutants results in embryonic lethality shortly after mid-gestation. The compensatory ECs are absent in Tbx1+/- embryos, a model for 22q11 deletion syndrome, leading to unpredictable arch artery morphogenesis and congenital heart disease. Tbx1 regulates the recruitment of the compensatory endothelium in an SHF-non-cell-autonomous manner.

CONCLUSIONS

Our studies uncover a novel buffering mechanism underlying the resiliency of PAA development and remodeling.

Hypoglossal nerve stimulation over-titration

This case report reviews worsening obstructive sleep apnea (OSA) events in a patient over-titrated with a hypoglossal nerve stimulator (HNS). A healthy 57-year-old man underwent HNS implantation for moderate OSA. During an in- laboratory HNS titration the patient had improvement of his OSA at 2.1V. However further increase of voltage resulted in worsening of obstructive events. The pathophysiology behind this finding is unknown but may result from unfavorable changes in the upper anatomy due to higher energy delivered to the hypoglossal nerve and surrounding structures. This high energy may also lead to genioglossus muscle fatigue. This finding highlights the importance of hypoglossal nerve stimulation titration with a dedicated sleep study.

Identification of novel buffering mechanisms in aortic arch artery development and congenital heart disease

Rationale

The resiliency of embryonic development to genetic and environmental perturbations has been long appreciated; however, little is known about the mechanisms underlying the robustness of developmental processes. Aberrations resulting in neonatal lethality are exemplified by congenital heart disease (CHD) arising from defective morphogenesis of pharyngeal arch arteries (PAA) and their derivatives.

Objective

To uncover mechanisms underlying the robustness of PAA morphogenesis.

Methods and Results

The second heart field (SHF) gives rise to the PAA endothelium. Here, we show that the number of SHF-derived ECs is regulated by VEGFR2 and Tbx1 . Remarkably, when SHF-derived EC number is decreased, PAA development can be rescued by the compensatory endothelium. Blocking such compensatory response leads to embryonic demise. To determine the source of compensating ECs and mechanisms regulating their recruitment, we investigated three-dimensional EC connectivity, EC fate, and gene expression. Our studies demonstrate that the expression of VEGFR2 by the SHF is required for the differentiation of SHF-derived cells into PAA ECs. The deletion of one VEGFR2 allele (VEGFR2 SHF-HET ) reduces SHF contribution to the PAA endothelium, while the deletion of both alleles (VEGFR2 SHF-KO ) abolishes it. The decrease in SHF-derived ECs in VEGFR2 SHF-HET and VEGFR2 SHF-KO embryos is complemented by the recruitment of ECs from the nearby veins. Compensatory ECs contribute to PAA derivatives, giving rise to the endothelium of the aortic arch and the ductus in VEGFR2 SHF-KO mutants. Blocking the compensatory response in VEGFR2 SHF-KO mutants results in embryonic lethality shortly after mid-gestation. The compensatory ECs are absent in Tbx1 +/- embryos, a model for 22q11 deletion syndrome, leading to unpredictable arch artery morphogenesis and CHD. Tbx1 regulates the recruitment of the compensatory endothelium in an SHF-non-cell-autonomous manner.

Conclusions

Our studies uncover a novel buffering mechanism underlying the resiliency of PAA development and remodeling.

Nonstandard Abbreviations and Acronyms in Alphabetical Order

CHD - congenital heart disease; ECs - endothelial cells; IAA-B - interrupted aortic arch type B; PAA - pharyngeal arch arteries; RERSA - retro-esophageal right subclavian artery; SHF - second heart field; VEGFR2 - Vascular endothelial growth factor receptor 2.

Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

BACKGROUND

Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation.

METHODS

WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109.

FINDINGS

Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0-4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2-6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital.

INTERPRETATION

In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates.

FUNDING

European Society of Intensive Care Medicine, European Respiratory Society.

Universal logic with encoded spin qubits in silicon

Quantum computation features known examples of hardware acceleration for certain problems, but is challenging to realize because of its susceptibility to small errors from noise or imperfect control. The principles of fault tolerance may enable computational acceleration with imperfect hardware, but they place strict requirements on the character and correlation of errors1. For many qubit technologies2-21, some challenges to achieving fault tolerance can be traced to correlated errors arising from the need to control qubits by injecting microwave energy matching qubit resonances. Here we demonstrate an alternative approach to quantum computation that uses energy-degenerate encoded qubit states controlled by nearest-neighbour contact interactions that partially swap the spin states of electrons with those of their neighbours. Calibrated sequences of such partial swaps, implemented using only voltage pulses, allow universal quantum control while bypassing microwave-associated correlated error sources1,22-28. We use an array of six 28Si/SiGe quantum dots, built using a platform that is capable of extending in two dimensions following processes used in conventional microelectronics29. We quantify the operational fidelity of universal control of two encoded qubits using interleaved randomized benchmarking30, finding a fidelity of 96.3% ± 0.7% for encoded controlled NOT operations and 99.3% ± 0.5% for encoded SWAP. The quantum coherence offered by enriched silicon5-9,16,18,20,22,27,29,31-37, the all-electrical and low-crosstalk-control of partial swap operations1,22-28 and the configurable insensitivity of our encoding to certain error sources28,33,34,38 all combine to offer a strong pathway towards scalable fault tolerance and computational advantage.

0818 Psychosis associated with sodium oxybate

Introduction

Sodium oxybate is commonly used to treat narcolepsy with cataplexy. At the approved doses, the most common side effects are typically described as nausea, vomiting, dizziness, hypersomnia, urinary disturbances, and weight loss. Cases of medication-induced psychosis have been reported in the literature but remain exceedingly rare. We present a case of rapid-onset psychosis in a patient with systemic lupus erythematosus, which added complexity to the evaluation, treatment and clinical course.

Report of Cases: The patient is a 42 year old woman with a past history of fibromyalgia, lupus and a prior diagnosis of narcolepsy evaluated for daytime hypersomnia and poor night time sleep. Prior medications included sodium oxybate which was effective; and modafinil and amphetamines which created intolerable side effects. Prior sleep studies were not available and a repeat PSG/MSLT were performed. PSG did not show sleep disordered breathing or nocturnal movements and MSLT showed an average sleep latency of 5.4 minutes and 4 SOREMs. HLA DQB10602 was positive. The patient was reinitiated on sodium oxybate and titrated to 4.5g twice nightly. A few weeks later the patient developed visual hallucinations, persecutory delusions, and insomnia for 3 days. She was admitted for an evaluation to rule out lupus cerebritis, and auto-immune vs. infectious encephalitis. MRI/MRA, lumbar puncture, as well as inflammatory markers and rheumatologic and infectious work up were unrevealing. Sodium oxybate was discontinued on the day of admission and the patient’s mentation returned to baseline over the next few days. Discharge diagnosis was psychosis secondary to sodium oxybate.

Conclusion

Psychosis is an extremely rare side effect of sodium oxybate therapy among patients treated for cataplectic narcolepsy. It remains a diagnosis of exclusion, and any alternative diagnoses must be explored prior to making the diagnosis of psychosis secondary to sodium oxybate, particularly in the medically complex patient.

Support (If Any)

None

CDK/cyclin dependencies define extreme cancer cell-cycle heterogeneity and collateral vulnerabilities

Progression through G1/S phase of the cell cycle is coordinated by cyclin-dependent kinase (CDK) activities. Here, we find that the requirement for different CDK activities and cyclins in driving cancer cell cycles is highly heterogeneous. The differential gene requirements associate with tumor origin and genetic alterations. We define multiple mechanisms for G1/S progression in RB-proficient models, which are CDK4/6 independent and elicit resistance to FDA-approved inhibitors. Conversely, RB-deficient models are intrinsically CDK4/6 independent, but exhibit differential requirements for cyclin E. These dependencies for CDK and cyclins associate with gene expression programs that denote intrinsically different cell-cycle states. Mining therapeutic sensitivities shows that there are reciprocal vulnerabilities associated with RB1 or CCND1 expression versus CCNE1 or CDKN2A. Together, these findings illustrate the complex nature of cancer cell cycles and the relevance for precision therapeutic intervention.

Knudsen et al. find that there is extensive heterogeneity in the requirement for CDK and cyclins across cancer models. Multiple biochemically distinct mechanisms drive cell division. Divergent cell-cycle states harbor distinct genetic and pharmacological vulnerabilities, suggesting that cell-cycle diversity could be exploited for a precision approach to cancer therapy.

Retrospective review of pyrocarbon radial head replacement

Background

Radial head arthroplasty is the preferred surgical management for complex, unreconstructable radial head fractures. There has been increasing use of pyrocarbon prostheses, with potential tribology and modulus advantages over metallic counterparts. This study aims to assess clinical and radiological outcomes for radial head replacement after trauma using a modular, uncemented pyrocarbon prosthesis.

Materials and Methods

Between September 2009 and March 2020, a consecutive series of 22 trauma cases were available for review. Patients underwent radial head arthroplasty using a pyrocarbon prosthesis (Ascension Modular Radial Head System, Austin, TX). Recorded outcomes included clinical assessment, radiological evaluation, and patient-reported outcome measures specific to elbow function.

Results

Twenty-two patients (7 male, 15 female) with an average age of 51 years (range 21-64) were analyzed with a minimum 12 months of follow-up. All patients had complex radial head fractures, categorized as a Mason 3 or 4 injury. At follow-up, mean elbow range of motion included flexion 130° (range 100°-150°), extension 19° (0-50°), pronation 73° (30°-90°), and supination 70° (10°-90°). The mean Mayo Elbow Performance Index score was 83 (55-100), and Disabilities of the Arm, Shoulder and Hand score was 22 (2.5-60). Radiological evaluation showed 14 patients with asymptomatic proximal neck resorption and two patients with radiological stem loosening. In total, 3 of 22 implants were revised-2 were excised, and 1 revised to a long stem for traumatic implant fracture.

Conclusion

Pyrocarbon radial head arthroplasty provided reliable functional results for patients after unreconstructable radial head fracture. The unique potential for fracture of the prosthesis should be considered in long-term follow-up, with appropriate activity advice to patients.

Abstract 1644: Targeting type I IFN-regulated secretory profiles to overcome acquired anti-PD-L1 resistance

Therapeutic inhibition of PD-L1 has led to durable benefits for many cancer patients; however, acquired resistance is common. Dysregulated type I and II interferon (IFN) signalling on tumor cells can contribute to resistance via altered expression of IFN stimulated genes (ISGs) leading to immune-suppression and tumor promotion. In this study, we examined the role of type I IFN signaling following acquired resistance to PD-L1 blockade using an EMT6 mouse breast orthotopic tumor model that was initially responsive to treatment, but that later relapsed. Following selection of PD-L1 drug resistant (PDR) tumor cells, transcriptomic and proteomic analysis was used to identify a unique signature of secreted proteins associated with IFN signaling that was then validated using published preclinical and clinical datasets. Using genetic and therapeutic approaches to block PD-L1 in vitro, we found PDR secretory signatures to be enhanced after type I IFN stimulation. In vivo, inhibition of specific ISGs (IL-6) or ISG regulators (IFNAR1) led to enhanced anti-tumor effects in PDR models, compared to parental controls. Together, these results identify a secretory profile associated with acquired resistance to PD-L1 blockade that may be modulated, in part, by a tumor-intrinsic PD-L1/IFN signaling crosstalk and suggest that selective targeting of secreted ISGs may provide benefit for patients after anti-PD-L1 treatment failure.

Citation Format: Yuhao Shi, Melissa Dolan, Michalis Mastri, James W. Hill, Kevin Eng, John M. Ebos. Targeting type I IFN-regulated secretory profiles to overcome acquired anti-PD-L1 resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1644.

Abstract 1180: A novel synthetic lethality treatment strategy for metastatic breast cancer

Breast carcinomas commonly carry mutations in the tumor suppressor p53, while therapeutic efforts to target mutant p53 were largely unfruitful. Here we present preclinical data supporting a novel combination therapy strategy for treatment of p53-deficient cancers. Genomic data revealed a high expression activity of Base-Excision Repair (BER) pathways in p53-deficient breast cancers. However, we found that BER-mediated repair was significantly dysregulated in p53-mutant cancer cells. Treatment with deoxyuridine analogues induced accumulation of DNA damage in p53-mutant cells and inhibitors of poly (ADP-ribose) polymerase (PARPi) greatly enhanced this response. In contrast, normal cells responded to PARPi with activation of the p53-p21 axis and cell cycle arrest. Inactivation of either p53 or p21/CDKN1A in p53 wild-type cells conferred the p53-mutant phenotype. Preclinical breast cancer studies revealed that the combination of deoxyuridine analogue with PARPi was more effective in inhibition of tumor growth and metastases than either drug alone. This work illustrates a novel combination therapy strategy that may improve survival rates and outcomes for thousands of breast cancer patients.

Citation Format: Justin Zonneville, Moyi Wang, Mohammed Alruwaili, Kevin Eng, Thomas Melendy, Ben Ho Park, Renuka Iyer, Christos Fountzilas, Andrei V. Bakin. A novel synthetic lethality treatment strategy for metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1180.

Non-invasive ventilation in patients with an altered level of consciousness. A clinical review and practical insights

Non-invasive ventilation has gained an increasingly pivotal role in the treatment of acute hypoxemic and/or hypercapnic respira-tory failure and offers multiple advantages over invasive mechanical ventilation. Some of these advantages include the preserva-tion of airway defense mechanisms, a reduced need for sedation, and an avoidance of complications related to endotracheal intubation. Despite its advantages, non-invasive ventilation has some contraindications that include, among them, severe encephalopathy. In this review article, the rationale, evidence, and drawbacks of the use of noninvasive ventilation in the context of hypercapnic and non-hypercapnic patients with an altered level of consciousness are analyzed.

Transcriptomic analysis of adhesive capsulitis of the shoulder

Adhesive capsulitis (AC) is a disabling condition of the shoulder joint affecting 2 to 5% of the general population. Our understanding of the molecular mechanisms is limited. The present study aimed to determine potential biomarkers of AC through transcriptomic analysis. This multi-centre study investigated patients undergoing arthroscopic capsulotomy surgery for resistant AC compared to those undergoing arthroscopic stabilization surgery for glenohumeral instability (control). Tissue samples were harvested from the anterior capsule during surgery. Total RNA was extracted and RNA-sequencing-based transcriptomics were performed. A number of genes deemed differentially expressed in RNA-sequencing analysis were validated using real-time reverse transcription polymerase chain reaction (RT-PCR). Baseline characteristics of the AC group (n = 22) were; mean age 52.7 years (SD: 10.2), 73% female, and Oxford Shoulder Score 19.6 (SD: 8.0), compared with the control group (n = 26), average age 23.9 years (SD: 5.2), 15% female, and Oxford Shoulder Score 39.0 (SD: 7.4). Transcriptomic analysis with false discovery rate correction and log₂ fold change cut-off of ±1.5 revealed 545 differentially expressed genes in AC relative to control. Bioinformatic analyses were carried out to identify biological processes and pathways enriched in this dataset. Real-time RT-PCR using two different normalization processes confirmed increased expression of matrix metallopeptidase 13 (MMP13) and platelet-derived growth factor subunit B (PDGFB), in patients with AC, while tumor necrosis factor α (TNFA) expression was reduced. These findings provide a comprehensive assessment of transcriptional changes associated with AC that give insights into the aetiology of the disease and provides a resource for molecular targets to better diagnose and treat this condition.

Percutaneous Cryoablation of Recurrent Pancreatic Mass for Life-Threatening Pancreatic VIPoma Syndrome: A Case Report

We present the case of a 73-year-old female who underwent percutaneous cryoablation for recurrent life-threatening pancreatic vasoactive intestinal polypeptide-producing tumor (VIPoma) following a pancreaticoduodenectomy and chemotherapy 5 years earlier. She presented with profuse watery diarrhea causing severe electrolyte and acid-base abnormalities, along with acute kidney injury. Cryoablation was successful in treating her profound symptoms, completely reversing her clinical course. The patient has made a successful recovery for the last 1.5 years since the procedure.

Functional Dart-Throwing Motion: A Clinical Comparison of Four-Corner Fusion to Radioscapholunate Fusion Using Inertial Motion Capture

Background  Dart-throwing motion (DTM) is an important functional arc of the wrist from radial extension to ulna flexion. An aim of partial fusion surgery of the wrist is to maintain maximal functional motion while addressing the pathology. The radioscapholunate (RSL) fusion, accompanied with partial resection of the distal scaphoid, is thought to allow better DTM than other partial wrist fusions such as the four-corner fusion (4CF). Question  Does an RSL fusion allow better functional DTM than 4CF, and how does this range compare with healthy wrists and the patient's contralateral wrist? Patients and Methods  Patients who have undergone an RSL fusion or 4CF at our tertiary center were identified and invited to present to have their DTM arc measured. To accurately measure DTM, a previously validated inertial measurement device was used. Patient's functional DTM arc was measured in both unrestrained (elbow and shoulder free to move) and restrained (elbow and shoulder immobilized) fashions. This was compared with their contralateral wrist and a group of healthy control volunteers. Results  Overall five RSL fusions, 10 4CF and 24 control patients were enrolled in the study. There was no significant difference between functional DTM when 4CF and RSL fusion were compared. Both had significantly reduced functional DTM arc than control patients. There was no significant difference between the operated wrist compared with the patient's contralateral unoperated wrist. Conclusion  RSL fusion is not significantly better at maintaining functional DTM when compared with 4CF. Both surgeries result in decreased functional DTM arc when compared with control patients. This is a cohort study and reflects a level of evidence IV. Level of Evidence  This is a Leve IV, cohort study.

Volar Scaphoid Plating for Nonunion: A Multicenter Case Series Study

Background  The volar scaphoid plate from Medartis (Medartis AG, Austrasse, Basel, Switzerland) is a variable angle titanium locking plate, preformed for the volar aspect of the scaphoid. It does not have compressive capability, and may act as a bridging device. It may provide an advantage over a compression screw where the pathoanatomy is less favorable to such a device with increased rotational stability. It may act as a buttress plate for correction of humpback deformity for example. It has been used in nonunions and with vascularized grafts. Questions  Our study aims to assess the results of our patients with scaphoid nonunion treated with scaphoid volar plating over a larger number of patients. We aim to identify techniques to increase the success of plating. Methods  Patients from our cohort were retrospectively reviewed. Operations were performed by three hand fellowship trained surgeons and in two centers. Inclusion involved a scaphoid plate procedure for a nonunion of the scaphoid with a minimum of 6 months of follow-up. Exclusions were those who had less than 6 months of follow-up. Data included demographics, patient-rated wrist evaluation (PRWE), a quick disabilities of the arm, shoulder, and hand (qDASH), visual analogue score, and range and grip. Radiology was reviewed. Results  Thirty-two eligible patients were assessed. The mean age was 25 years (range 13-46), 2 were female and 15 were smokers. Mean follow-up postsurgery was 18 months. Twenty-nine of 32 patients united (90.6%) on computed tomography scan. Clinical assessment was performed in the 25 patients. The mean qDASH score was 12.5 (range 0-42) and mean PRWE was 11 (range 0-54). The mean arc of motion was 115 degrees. The mean grip strength was 39 kg compared with 41 kg on the nonoperated side. Conclusion  We postulate that the plate acts like an internal bridging device, acting over a small distance, and inherent stability of the construct with structural graft and accurate reduction prior to plating is advantageous. Potential problems include plate impingement on the volar lip of the radius, particularly when trying to plate more proximal fractures. Ideally, it is utilized for mid to distal waist fractures.

Diaphyseal Screw Prominence in Distal Radius Volar Plating

Background  Volar plating for distal radius fractures has become common. Screw prominence on the dorsal side from long screws can lead to tendon injury. Methods for detecting screws that penetrate the far cortex involve X-ray or ultrasound. These have focused on the distal row of screws. No studies have addressed screw penetration in the diaphysis. We describe two cases where diaphyseal screws caused symptoms. We then insert screws in the diaphysis of synbones 2 mm longer than measured and determine what angle of pronation or supination was best to detect this on X-ray. Methods  Three synbones were plated using Synthes volar plate. The three diaphyseal screws were drilled perpendicular to the plate, and the depth measured. Cortical 2.4-mm screws were inserted, 2 mm longer than measured. The three synbones were then placed in a custom clamp to measure rotation. Lateral X-rays were taken at 0 degree rotation, and 5, 10, and 15 degrees of supination and pronation. The prominence of each screw was measured using the synapse digital ruler. Results  For the screws that were placed at a neutral angle (perpendicular to the plate) the maximum visualization of the prominent tips occurred around 0 degree rotation. With screws angled 15 degrees ulna, maximum visualization was between 5 and 10 degrees of pronation. With screws angled 15 degrees radial, maximum visualization was between 5 and 10 degrees of supination. Every 5 degrees of rotation changes the profile of the screw by 0.4 mm. Discussion  The diaphysis of the radius becomes approximately trapezoidal distally. Prominent screws that are placed below the "peak" of the trapezoid may appear to be the correct length. Rotating the wrist into pronation or supination to bring the relevant cortex as parallel to the X-ray beam as possible will help to identify if screws are of the correct length. Screws that are prominent in the second compartment may be particularly symptomatic as the tendons here are closely opposed to the bone. We recommend screening for 2 mm diaphyseal screw prominence in neutral, with 10 degrees of pronation and supination.

Variant phasing and haplotypic expression from long-read sequencing in maize

Haplotype phasing maize genetic variants is important for genome interpretation, population genetic analysis and functional analysis of allelic activity. We performed an isoform-level phasing study using two maize inbred lines and their reciprocal crosses, based on single-molecule, full-length cDNA sequencing. To phase and analyze transcripts between hybrids and parents, we developed IsoPhase. Using this tool, we validated the majority of SNPs called against matching short-read data from embryo, endosperm and root tissues, and identified allele-specific, gene-level and isoform-level differential expression between the inbred parental lines and hybrid offspring. After phasing 6907 genes in the reciprocal hybrids, we annotated the SNPs and identified large-effect genes. In addition, we identified parent-of-origin isoforms, distinct novel isoforms in maize parent and hybrid lines, and imprinted genes from different tissues. Finally, we characterized variation in cis- and trans-regulatory effects. Our study provides measures of haplotypic expression that could increase accuracy in studies of allelic expression.

Adhesive capsulitis of the shoulder: protocol for the adhesive capsulitis biomarker (AdCaB) study

Background

Adhesive capsulitis (AC) is a disabling and poorly understood pathological condition of the shoulder joint. The current study aims to increase our understanding of the pathogenesis, diagnosis and clinical outcomes of people with AC by investigating: 1) transcriptome-wide alterations in gene expression of the glenohumeral joint capsule in people with AC compared to people with non-inflammatory shoulder instability (controls); 2) serum and urine biomarkers to better understand diagnosis and staging of AC; and 3) clinical outcomes in people with AC compared to controls 12-months following arthroscopic capsular release or labral repair respectively.

Methods

The study is a prospective multi-centre longitudinal study investigating people undergoing arthroscopic capsulotomy for AC compared to people undergoing arthroscopic stabilization for shoulder instability. Tissue samples collected from the anterior glenohumeral joint capsule during surgery will undergo RNA-seq to determine differences in gene expression between the study groups. Gene Set Enrichment Analysis will be used to further understand the pathogenesis of AC as well as guide serum and urine biomarker analysis. Clinical outcomes regarding pain, function and quality of life will be assessed using the Oxford Shoulder Score, Oxford Shoulder Instability Score, Quick DASH, American Shoulder and Elbow Society Score, EQ-5D-5 L and active shoulder range of movement. Clinical outcomes will be collected pre-operatively and 12-months post-operatively and study groups will be compared for statistically significant differences using linear regression, adjusting for baseline demographic variables.

Discussion

This study will provide much needed information regarding the pathogenesis, diagnosis and staging of AC. It will evaluate clinical outcomes for people undergoing arthroscopic release of AC by comparing this group to people undergoing arthroscopic surgery for shoulder instability.

Trial registration

ACTRN12618000431224, retrospectively registered 26 March 2018.

Abstract A084: Towards combining androgen deprivation and immunotherapy to prevent progression to castration-resistant prostate cancer

Most prostate cancer (PCa) deaths are due to castration-resistant PCa (CRPC), following failure of androgen-deprivation therapy (ADT). ADT is the standard of care for patients with advanced PCa. However, nearly universal progression to castration-resistant prostate cancer (CRPC) occurs 2-3 years after ADT is initiated. Although there have been recent improvements in the treatment of CRPC, even the most promising therapies are still not curative. One approach to this problem is to improve the initial treatment of advanced prostate cancers, by combining complementary therapies with ADT, to prevent progression of such advanced cancers to CRPC. Immunotherapy with checkpoint inhibitors (CPIs) has not been effective in prostate cancers, perhaps because such cancers are “cold” (lacking cytolytic CD8 T-cells). Some cold tumors may be caused by infiltration of myeloid cell populations (tumor associated macrophages and myeloid-derived suppressor cells) into the tumor immune cell microenvironment (TIME). Recently, we found that in a PTEN-deficient mouse PCa model, castration induces an immunosuppressive state within the tumor that is concurrent with tumor recurrence. The response to castration/ADT is tri-phasic: a pro-apoptotic regression phase when tumor shrinks, followed by selection for a residual population of resistant tumor cells and finally recurrent growth as CRPC. Using PCa cell lines to model the first two phases of the response to ADT, we have shown that ADT induces apoptosis, thereby enriching for an ADT-resistant stem/progenitor population that we propose is the in vivo source of TNF. Mechanistically, in our model system the response to ADT is driven by the soluble mediators TNF and CCL2, which facilitate communication within the TIME. Specifically, a TNF-CCL2-CCR2 paracrine loop is induced between prostate cancer cells and non-tumor cells in the microenvironment: TNF produced by tumor cells acts on myofibroblasts to induce CCL2 production, which in turn recruits CCR2+ tumor-associated macrophages (TAMs). To investigate the ADT response within the TIME in an in vivo model of prostate cancer, we employed a prostate-specific PTEN-deficient mouse model (PbCre4 x PTENf/f). Castration caused the tumors to regress, consistent with initial phase of the response that is seen in the human disease. At late times post-castration (5-6 weeks), corresponding to the selection phase, we observed a coordinate increase in the stem/progenitor tumor cell population, as well as TNF and CCL2, within the TIME. Immunohistochemical staining of tumors 5 weeks post-castration revealed an increase in TAMs, and a decrease in CD8 T-cells, consistent with an immunosuppressive or immunoevasive state. This phenotype was reversed by a soluble receptor that binds TNF (etanercept). We also observed increased myeloid-derived suppressor cells (MDSC). Thus, following ADT, TNF derived from an ADT-resistant stem/progenitor epithelial tumor cell population promotes an immunosuppressive state via CCL2 in the TIME. Analysis of public human PCa data sets shows TNF and stem/progenitor marker expression are both increased in CRPC, consistent with our hypothesis that ADT drives the development of an immunosuppressive state via a TNF-CCL2-CCR2 axis. Our results set the stage for the future development of immunotherapies that could improve the efficacy of ADT.

Citation Format: John J. Krolewski, Kai Sha, Michalis Mastri, Dean Tang, Kevin Eng, Kent L. Nastiuk. Towards combining androgen deprivation and immunotherapy to prevent progression to castration-resistant prostate cancer [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A084.

Ultrarestrictive Opioid Prescription Protocol for Pain Management After Gynecologic and Abdominal Surgery

IMPORTANCE

Opioids are routinely prescribed for postoperative home pain management for most patients in the United States, with limited evidence of the amount needed to be dispensed. Opioid-based treatment often adversely affects recovery. Prescribed opioids increase the risk of chronic opioid use, abuse, and diversion and contribute to the current opioid epidemic.

OBJECTIVE

To evaluate whether after hospital discharge, postsurgical acute pain can be effectively managed with a markedly reduced number of opioid doses.

DESIGN, SETTING, AND PARTICIPANTS

In this case-control cohort study, an ultrarestrictive opioid prescription protocol (UROPP) was designed and implemented from June 26, 2017, through June 30, 2018, at a single tertiary-care comprehensive cancer center. All patients undergoing gynecologic oncology surgery were included. Patients undergoing ambulatory or minimally invasive surgery (laparoscopic or robotic approach) were not prescribed opioids at discharge unless they required more than 5 doses of oral or intravenous opioids while in the hospital. Patients who underwent a laparotomy were provided a 3-day opioid pain medication supply at discharge.

MAIN OUTCOMES AND MEASURES

Total number of opioid pain medications prescribed in the 60-day perioperative period, requests for opioid prescription refills, and postoperative pain scores and complications were evaluated. Factors associated with increased postoperative pain, preoperative and postoperative pain scores, inpatient status, prior opioid use, and all opioid prescriptions within the 60-day perioperative window were monitored among the case patients and compared with those from consecutive control patients treated at the center in the 12 months before the UROPP was implemented.

RESULTS

Patient demographics and procedure characteristics were not statistically different between the 2 cohorts of women (605 cases: mean [SD] age, 56.3 [14.5] years; 626 controls: mean [SD] age, 55.5 [13.9] years). The mean (SD) number of opioid tablets given at discharge after a laparotomy was 43.6 (17.0) before implementation of the UROPP and 12.1 (8.9) after implementation (P < .001). For patients who underwent laparoscopic or robotic surgery, the mean (SD) number of opioid tablets given at discharge was 38.4 (17.4) before implementation of the UROPP and 1.3 (3.7) after implementation (P < .001). After ambulatory surgery, the mean (SD) number of opioid tablets given at discharge was 13.9 (16.6) before implementation of the UROPP and 0.2 (2.1) after implementation (P < .001). The mean (SD) perioperative oral morphine equivalent dose was reduced to 64.3 (207.2) mg from 339.4 (674.4) mg the year prior for all opioid-naive patients (P < .001). The significant reduction in the number of dispensed opioids was not associated with an increase the number of refill requests (104 patients [16.6%] in the pre-UROPP group vs 100 patients [16.5%] in the post-UROPP group; P = .99), the mean (SD) postoperative visit pain scores (1.1 [2.2] for the post-UROPP group vs 1.4 [2.3] for pre-UROPP group; P = .06), or the number of complications (29 cases [4.8%] in the post-UROPP group vs 42 cases [6.7%] in the pre-UROPP group; P = .15).

CONCLUSIONS AND RELEVANCE

Implementation of a UROPP was associated with a significant decrease in the overall amount of opioids prescribed to patients after gynecologic and abdominal surgery at the time of discharge for all patients, and for the entire perioperative time for opioid-naive patients without changes in pain scores, complications, or medication refill requests.

Cementless versus cemented glenoid components in conventional total shoulder joint arthroplasty: analysis from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

Glenoid loosening is a common mode of failure after total shoulder arthroplasty (TSA). Newer cementless glenoid components have been introduced to promote biological fixation with the aim to decrease glenoid loosening. Limited data are available comparing revision rates between cemented and cementless glenoid fixation in TSA. The study aim was to compare the revision rates of cemented and cementless design glenoid components used in conventional TSA performed for the diagnosis of osteoarthritis. The secondary aim was to compare various subclasses of glenoid components.

METHODS

Data were obtained between April 16, 2004, and December 31, 2016, from the Australian Orthopaedic Association National Joint Replacement Registry. Within the study period, 10,805 primary conventional TSAs were identified. The analysis was undertaken for the diagnosis of osteoarthritis, which represented 95.8% of all conventional TSA procedures.

RESULTS

At 5 years, in patients with primary TSA procedures, those with cemented glenoids had a lower revision rate than those with cementless glenoids: 3.7% versus 17.9% (hazard ratio for entire period, 4.77). The most common revision diagnosis for primary conventional TSA with cementless glenoid fixation was rotator cuff insufficiency (4.4% for cementless vs 0.4% for cemented), instability and/or dislocation (3.8% for cementless vs 0.8% for cemented), and loosening and/or lysis (1.1% for cementless vs 1.1% for cemented).

CONCLUSIONS

Cementless glenoid components in conventional TSA had a significantly higher revision rate than cemented glenoid components. The loosening rates between cemented and cementless glenoid components were similar. Glenoid design and fixation are important considerations when selecting a prosthesis for TSA.

Abstract B55: Recurrent transcriptional remodeling events and acquired fusion RNAs in relapsed ovarian cancers

Background: The majority of ovarian cancers (OvCa) are exquisitely sensitive to primary cytoreductive surgery and platinum-based agents, yet up to 80% of late-stage disease will relapse and develop deadly resistance to subsequent therapies. Identifying molecular mediators driving this acquired resistance is essential to improve the tragic 12- to 18-month prognosis for patients with recurrent disease. We hypothesize that relapsed ovarian cancers—which are largely uncharacterized—are molecularly distinct from primary disease and acquire druggable vulnerabilities throughout their life histories. To test this hypothesis, we undertook a transcriptome-wide analysis of 19 longitudinally collected patient-matched pairs of chemotherapy-naïve and recurrent cancers.

Materials and Methods: Ilumina TruSeq Total RNA-sequencing was performed on 19 flash-frozen patient-matched pairs of primary and recurrent OvCa. Time to recurrence was up to 64 months with a median of 25 months—a shared variant analysis confirmed all paired samples were patient-matched. Adapter-trimmed RNA-sequencing reads were quantified with k-mer based lightweight-alignment (Salmon v0.8.2) and transcript-abundance estimates were collapsed to gene-level with tximport. Differentially expressed genes were determined with DESeq2 using a paired model to account for patient-matched samples. To identify gains and losses in clinically actionable genes (DGIdb 2.0), pair-specific, outlier fold-change thresholds were defined as Q1/Q3 -/+ [1.5 X IQR], using each pairs’ expression fold-change values (recurrence vs. primary) as the distribution. These discrete, longitudinal transcriptional remodeling events (LTREs) in relapsed OvCa were then assessed for recurrence across all cases. Given that OvCa is thought to be driven largely by genomic structural variation, fusion RNAs were then called with FusionCatcher v0.99.7b. Identified fusions were filtered for cancer specificity by discarding fusions detected in normal tissue (Human Protein Atlas and BodyMap). The same fusion analysis was performed on CCLE OvCa cell line RNA-seq and selected fusions were validated with RT-PCR and Sanger sequencing.

Results: A suite of genes were consistently upregulated in OvCa recurrences, the most significant being NTRK2 (adjusted p-value &lt; 0.001)—a targetable tyrosine kinase. LTREs were also common with the most shared LTRE gains in recurrences being INHBA (44%) and IGF1 (39%). 18 of 19 (95%) recurrent cancers acquired cancer-specific fusion RNAs that were undetectable in the primary lesion. An in-frame, recurrence-acquired fusion between TOP2A, a target of doxorubicin and known chemoresistance mediator, and STAU1 was confirmed with RT-PCR. Lastly, we discovered recurrent (2 of 19 cases), in-frame CCDC6-ANK3 fusions that persisted throughout therapy in both the primary and relapsed lesions, each with distinct breakpoints. A CCDC6-ANK3 fusion was also validated in the chemoresistant OVCAR3 cell line. 15 of 19 cases (79%) harbored additional preserved fusions, albeit none were shared between cases.

Conclusions: Collectively, these results define multimodal transcriptomic mechanisms of ovarian cancer evolution in late disease. Considering that some acquisitions are highly recurrent and readily druggable (NTRK2, IHBA, IGF1), further preclinical studies are demanded and currently ongoing. Lastly, we establish acquired fusions involving known chemoresistance modulators and preserved fusion transcripts—which are maintained throughout therapy—as common somatic events in OvCa. Because fusion breakpoints are cancer specific, they may serve as promising patient-specific nucleotide targets and biomarkers.

Citation Format: Nolan Priedigkeit, Sarah Taylor, Shannon Grabosch, Jahnik Kurukulasuriya, Peter C. Lucas, Silvia Liu, Ester Elishaev, Amit Lugade, Kevin Eng, Anda Vlad, George C. Tseng, Kunle Odunsi, Robert P. Edwards, Adrian V. Lee. Recurrent transcriptional remodeling events and acquired fusion RNAs in relapsed ovarian cancers. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr B55.

Long-term outcomes after infected mini-open rotator cuff repair: results of a 10-year review

BACKGROUND

Infection after rotator cuff repair (RCR) is uncommon. There are few reports in the literature regarding the management and long-term results of patients in whom deep infection of the shoulder develops after RCR. The objective of this study was to assess the long-term clinical and radiologic outcomes of these patients.

METHODS

We retrospectively reviewed a consecutive series of 764 patients after mini-open RCR in which 9 patients had postoperative infection. The demographic data, clinical and laboratory findings, risk factors, bacteriologic findings, and results of surgical management were analyzed. All patients underwent clinical and radiologic assessment at long-term follow-up of approximately 10 years after infection.

RESULTS

The mean age of the patients was 56.2 years. The mean time to presentation for infection after RCR was 16 days. All patients had pain on presentation, and 6 patients had persistent discharge from their wounds with erythema. The most common organism was Staphylococcus aureus. At final follow-up at a mean of 11.62 years after surgery, the mean Simple Shoulder Test score was 10.5 and the mean Constant score was 70. The rotator cuff was intact in 5 of 7 patients.

CONCLUSION

With appropriate treatment, eradication of infection can be achieved, and in appropriate cases, anchors can be retained. Reasonable long-term functional outcome scores can be achieved.

Hereditary association between testicular cancer and familial ovarian cancer: A Familial Ovarian Cancer Registry study

BACKGROUND

Although family history of testicular cancer is well-established as a risk factor for testicular cancer, it is unknown whether family history of ovarian cancer is associated with risk of testicular cancer.

MATERIALS AND METHODS

Using data from the Familial Ovarian Cancer Registry on 2636 families with multiple cases of ovarian cancer, we systematically compared relative frequencies of ovarian cancer among relatives of men with testicular and non-testicular cancers.

RESULTS

Thirty-one families with cases of both ovarian and testicular cancer were identified. We observed that, among men with cancer, those with testicular cancer were more likely to have a mother with ovarian cancer than those with non-testicular cancers (OR = 3.32, p = 0.004). Zero paternal grandmothers of men with testicular cancer had ovarian cancer.

CONCLUSION

These observations provide compelling preliminary evidence for a familial association between ovarian and testicular cancers Future studies should be designed to further investigate this association and evaluate X-linkage.

In-hospital cardiac arrest among patients with malignancy

e21583

Background: Malignancy is generally considered a poor prognosticator for in-hospital cardiopulmonary arrest. Recent studies have shown that overall survival in those with localized disease and fewer than two comorbidities approximates the general population, likely reflective of advances in cancer treatment and more selective use of cardiopulmonary resuscitation. The present study was conducted to evaluate whether malignancy is an independent risk factor for death before discharge following in-hospital cardiopulmonary arrest. Methods: This single-center retrospective study included consecutive in-hospital cardiac arrests for whom cardiopulmonary resuscitation was attempted between 2011-2015. Patients were identified from an inpatient cardiac arrest registry and excluded if the arrest occurred in the operating room or emergency department prior to admission. Data related to each patient’s oncologic history was obtained via manual chart review by physician investigators. The primary outcome was survival to discharge among patients according to malignancy status. Results: Over the five-year study, 532 patients experienced in-hospital arrest and met inclusion criteria. Fifteen percent (n = 81) had a known cancer diagnosis at the time of arrest; 9% of arrests (n = 46) had a cancer that was considered active (not in remission). One-fourth of all cancer diagnoses at time of arrest were hematologic malignancies. Overall post-arrest survival to discharge was 34%. Survival did not differ significantly for patients with versus without current or prior malignancy (OR 0.69, 95% CI 0.41-1.18; p = 0.17), nor with active malignancy at time of arrest (OR 0.52; 95% CI 0.25-1.07; p = 0.08). The subgroup of patients with hematologic malignancy had significantly lower survival (OR 0.21, 95% CI 0.05-0.91; p = 0.04). Conclusions: Malignancy was not associated with decreased survival to hospital discharge among patients experiencing in-hospital arrest for whom resuscitation was attempted.

Use of hematologic biomarkers during chemotherapy predicts survival in ovarian cancer patients

OBJECTIVE

The optimal strategy for combining chemotherapy with immunotherapy in ovarian cancer patients is currently under investigation. Increasing evidence indicates that the lymphopenia induced by chemotherapy may promote homeostatic proliferation and thereby enhance antitumor immunity. Furthermore, there has been much discussion and even discord over the effects of anemia and blood transfusion in the perichemnotherapy period. The goals of this retrospective study were to determine the timing of chemotherapy induced lymphopenia and to observe perichemnotherapy hemoglobin levels, and the impact of the timing and depth of lymphopenia and anemia on clinical outcomes of ovarian cancer patients.

MATERIALS AND METHODS

A chart review was performed on 115 patients identified in the electronic medical record from May 2005 until May 2011. Identified patients were only those who received at least six cycles of carboplatin and paclitaxel under the present authors' care for primary peritoneal, ovarian, or fallopian tube carcinoma. Specifically, the authors focused on lymphocyte and hemoglobin nadir and the reconstitution kinetics for this population. For each patient's lymphocyte count, nadir values were abstracted from weekly complete blood counts. They then split the population into two groups based on whether the nadir occurred at or after the nine-week mark (third cycle) for the lymphopenia data; this point was chosen because it was good for prognosis and it corresponds to patients whose trajectories bottom out. The intrachernotherapy hemoglobin levels were observed and an exploratory analysis was performed to attempt to identify a range that significantly effected patient outcomes.

RESULTS

Lymiphocytes: The nadir of absolute lymphocyte concentrations is associated with platinum status and clinical response (Figure 1A). 94/115 patients had a lymphocyte count nadir after the third cycle of chemotherapy. 71/94 (75.5%) were platinum sensitive, 21/94 (22.3%) were resistant, and 2/94 (2.1%) were refractory. Of those that experienced a nadir before three cycles, ten (47.6%) were sensitive, ten (47.6%) were resistant, and one (4.7%) was refractory (p = 0.04). Considering nadir values continuously, both overall survival (OS,p = 0:0068) and progression free survival (PFS,p = 0:0321) were strongly associated with late nadir points. Twenty-one of the 115 patients had a nadir value earlier than the third draw and this was associated with progressive disease, platinum resistance, poor over- all survival, and poor progression free survival. The effect sizes were great [median 0S533 vs. 66 months median PFS, 14 vs. 38 months, early vs. late nadir respectively (Figure 11B)]. Hemzoglobin: A mean Hb less than 12.5 is associated with both overall survival (OS) (HR = 2.11, 95% CI: 1.03-4.33; p= 0:042) and progression free survival (PFS) (HR = 1.91, 95% CI: l.02-3.56; p= 0:041), as were low Hb level at outset of chemotherapy and a decreasing Hb trend over the course of treatment. Furthermore, for each cycle of chemotherapy in which the hemoglobin was recorded at avalue less than 11, hazard increased, with OS (HR = 3.51, 95% CI: 1.63-7.54, p = 0:0Ol3), and PFS (HR = 2.20, 95% CI:1.12-4.33; p = 0:0223). Deeper analysis revealed that outcomes were significantly affected when a pa- tient had three or more cycles with Hb less than 11 with both 05 (HR = 2.34, 95% Cl: 1.37-4.01; Wald-Test p = 0:0020, Log Rank p = 0.00145) and PFS (HR =1.88, 95% CI: 1. 17-3.02; Wald-Test p = 0:009, Log Rank p = 0.00743).

CONCLUSION

The nadir of absolute lymphocyte concentrations is an independent predictor of overall survival and progression free survival. This is an easily measurable biomarker which can be utilized for identifying patients that will be likely to respond to immunomodulation. Furthermore, this evidence showing significant improvement in OS and PFS with two or less cycles with hemoglobin < 11 sheds new light on the need for further studies on growth stimulating factors and blood transfusion during this treatment period.

Optimal Lateral Row Anchor Positioning in Posterior-Superior Transosseous Equivalent Rotator Cuff Repair: A Micro-Computed Tomography Study

Background:

The optimal placement of suture anchors in transosseous-equivalent (TOE) double-row rotator cuff repair remains controversial.

Purpose:

A 3-dimensional (3D) high-resolution micro–computed tomography (micro-CT) histomorphometric analysis of cadaveric proximal humeral greater tuberosities (GTs) was performed to guide optimal positioning of lateral row anchors in posterior-superior (infraspinatus and supraspinatus) TOE rotator cuff repair.

Study Design:

Descriptive laboratory study.

Methods:

Thirteen fresh-frozen human cadaveric proximal humeri underwent micro-CT analysis. The histomorphometric parameters analyzed in the standardized volumes of interest included cortical thickness, bone volume, and trabecular properties.

Results:

Analysis of the cortical thickness of the lateral rows demonstrated that the entire inferior-most lateral row, 15 to 21 mm from the summit of the GT, had the thickest cortical bone (mean, 0.79 mm; P = .0001), with the anterior-most part of the GT, 15 to 21 mm below its summit, having the greatest cortical thickness of 1.02 mm (P = .008). There was a significantly greater bone volume (BV; posterior, 74.5 ± 27.4 mm³; middle, 55.8 ± 24.9 mm³; anterior, 56.9 ± 20.7 mm³; P = .001) and BV as a percentage of total tissue volume (BV/TV; posterior, 7.3% ± 2.7%, middle, 5.5% ± 2.4%; anterior, 5.6% ± 2.0%; P = .001) in the posterior third of the GT than in intermediate or anterior thirds. In terms of both BV and BV/TV, the juxta-articular medial row had the greatest value (BV, 87.3 ± 25.1 mm³; BV/TV, 8.6% ± 2.5%; P = .0001 for both) followed by the inferior-most lateral row 15 to 21 mm from the summit of the GT (BV, 62.0 ± 22.7 mm³; BV/TV, 6.1% ± 2.2%; P = .0001 for both). The juxta-articular medial row had the greatest value for both trabecular number (0.3 ± 0.06 mm^–1; P = .0001) and thickness (0.3 ± 0.08 μm; P = .0001) with the lowest degree of trabecular separation (1.3 ± 0.4 μm; P = .0001). The structure model index (SMI) has been shown to strongly correlate with bone strength, and this was greatest at the inferior-most lateral row 15 to 21 mm from the summit of the GT (2.9 ± 0.9; P = .0001).

Conclusion:

The inferior-most lateral row, 15 to 21 mm from the tip of the GT, has good bone stock, the greatest cortical thickness, and the best SMI for lateral row anchor placement. The anterior-most part of the GT 15 to 21 mm below its summit had the greatest cortical thickness of all zones. The posterior third of the GT also has good bone stock parameters, second only to the medial row. The best site for lateral row cortical anchor placement is 15 to 21 mm below the summit of the GT.

Clinical Relevance:

Optimal lateral anchor positioning is 15 to 21 mm below the summit of the greater tuberosity in TOE.

Abstract 3646: Highly sensitive and cost-effective detection of somatic cancer variants using single-molecule, real-time sequencing

Next-Generation Sequencing (NGS) technologies allow for molecular profiling of cancer samples with high sensitivity and speed at reduced cost. For efficient profiling of cancer samples, it is important that the NGS methods used are not only robust but also capable of accurately detecting low-frequency somatic mutations. Single Molecule, Real-Time (SMRT®) Sequencing offers several advantages, including the ability to sequence single molecules with very high accuracy (&gt;QV40) using the circular consensus sequencing (CCS) approach. The availability of genetically defined, human genomic reference standards provides an industry standard for the development and quality control of molecular assays for studying cancer variants. Here we characterize SMRT Sequencing for the detection of low-frequency somatic variants using the Quantitative Multiplex DNA Reference Standards from Horizon Diagnostics, combined with amplification of the variants using the Multiplicom Tumor Hotspot MASTR Plus assay.

First, we sequenced a reference standard containing precise allelic frequencies from 1% to 24.5% for major oncology targets verified using digital PCR. This reference material recapitulates the complexity of tumor composition and serves as a well-characterized control. The control sample was amplified using the Multiplicom Tumor Hotspot MASTR Plus assay that targets 252 amplicons (121-254 bp) from 26 relevant cancer genes, which includes all 11 variants in the control sample. We also sequenced a second sample containing a series of mixes, each with known mutations, at levels below 10% and down to 0.01%. PCR-amplified targets were sequenced and analyzed using SMRT Sequencing to identify the variants and determine the observed frequency. The random error profile and high-accuracy CCS reads make it possible to accurately detect low-frequency somatic variants.

Citation Format: Steve Kujawa, Anand Sethuraman, Kevin Eng, Primo Baybayan, Lien Heyrman, Jurgen Del Favero. Highly sensitive and cost-effective detection of somatic cancer variants using single-molecule, real-time sequencing. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3646.

Abstract 3611: SMRT® sequencing of DNA samples extracted from formalin-fixed and paraffin embedded tissues

Recent advances in next generation sequencing have led to the increased use of formalin-fixed and paraffin-embedded (FFPE) tissues for medical samples in disease and scientific research. Single Molecule Real-Time (SMRT®) sequencing offers a unique advantage in that it allows direct analysis of FFPE samples without amplification. However, obtaining ample long read information from FFPE samples has been a challenge due to the quality and quantity of the extracted DNA. DNA samples extracted from FFPE often contain damaged sites, including breaks in the backbone and missing or altered nucleotide bases, which directly impact sequencing and amplification. Additionally, the quality and quantity of the recovered DNA also vary depending on the extraction methods used.

We have evaluated the Adaptive Focused Acoustics (AFA™) system by Covaris® as a method for obtaining high molecular weight DNA suitable for SMRTbell template preparation and subsequent single molecule sequencing. Using this method, genomic DNA was extracted from normal kidney FFPE scrolls acquired from Cooperative Human Tissue Network (CHTN), University of Pennsylvania. Damaged sites present in the extracted DNA were repaired using a DNA Damage Repair step, and the treated DNA was constructed into SMRTbell libraries suitable for sequencing on the RSII System. Using the same repaired DNA, we also tested PCR efficiency of target gene regions of up to 5 kb. The resulting amplicons were constructed into SMRTbell templates for full-length sequencing on the RS II System.

We found the Adaptive Focused Acoustics (AFA™) system by Covaris® to be effective and efficient. This system is easy and simple to use, and the resulting DNA is compatible with SMRTbell™ library preparation for targeted and whole genome SMRT sequencing. The data presented here demonstrates single molecule sequencing of DNA samples extracted from tissues embedded in FFPE.

Citation Format: Primo Baybayan, Michael Weiand, Kevin Eng, Guillaume Durin, Steve Kujawa. SMRT® sequencing of DNA samples extracted from formalin-fixed and paraffin embedded tissues. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3611.

Reduced Sensitivity to Charge Noise in Semiconductor Spin Qubits via Symmetric Operation

We demonstrate improved operation of exchange-coupled semiconductor quantum dots by substantially reducing the sensitivity of exchange operations to charge noise. The method involves biasing a double dot symmetrically between the charge-state anticrossings, where the derivative of the exchange energy with respect to gate voltages is minimized. Exchange remains highly tunable by adjusting the tunnel coupling. We find that this method reduces the dephasing effect of charge noise by more than a factor of 5 in comparison to operation near a charge-state anticrossing, increasing the number of observable exchange oscillations in our qubit by a similar factor. Performance also improves with exchange rate, favoring fast quantum operations.

Abstract B10: Increased expression of EZH2 and TOP2A predicts for a poorer prognostic outcome in Genitourinary Cancers

The enhancer of Zeste homolog 2 (EZH2), a component of the Polycomb Repressive Complex 2 (PRC2), is an epigenetic silencer that is known to be highly expressed in both metastatic and primary prostate cancer (PCa). More recently, topoisomerase IIα (TOP2A), an enzyme that controls the topologic states of DNA during the cell cycle, has also been identified as being highly expressed in PCa. Both EZH2 and TOP2A have been associated with more aggressive disease and poorer prognostic outcome. During genome-wide analysis, using The Cancer Genome Atlas (TCGA), EZH2 and Top2A were found to be highly positively correlated, most noticeably in PCa and clear cell Renal Cell Carcinoma (ccRCC). As a result, we predicted increased expression of both EZH2 and TOP2A in an individual, would predict for a worse prognostic outcome than either gene being highly expressed alone. Further analysis of the TCGA and Memorial Sloan Kettering Cancer Center (MSKCC) datasets, demonstrated that increased expression of these two genes predicted for a poorer prognostic outcome in genitourinary cancers. In tumor samples with increased expression of EZH2 and TOP2A, as compared to the tumor samples that did not concurrently overexpress both EZH2 and TOP2A, patients displayed worse overall Regression Free Survival (RFS), which were associated with increase hazard ratio, and tumor staging and grades. . As these poor prognostic markers were consistent across multiple cancer subtypes, we are beginning to explore those genes that are differentially expressed in individuals with concurrent high TOP2A and EZH2 as a means of further characterizing this novel phenotype. Since these two genes are targetable by drugs such as etoposide (a TOP2 poison) and DZNep (an EZH2 inhibitor), it makes them attractive candidates for treatment in those individuals who not only have tumors that highly express these two genes, but also those individuals that have exacerbated existing treatment options.

Citation Format: Spencer Rosario, Zafardjan Dalimov, Jason Kirk, Kayla Morrell, Kevin Eng, Leigh Ellis. Increased expression of EZH2 and TOP2A predicts for a poorer prognostic outcome in Genitourinary Cancers. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Sep 24-27, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2016;76(2 Suppl):Abstract nr B10.

Docetaxel and nab-paclitaxel are safe alternative options for patients with gynecologic malignancies following hypersensitivity reaction to paclitaxel

Docetaxel and nab-paclitaxel are safe alternatives to paclitaxel after hypersensitivity reaction occurs. There was no significant difference in overall survival between those that had paclitaxel, docetaxel, and nab-paclitaxel.

Cable-Augmented, Quad Ligament Tenodesis Scapholunate Reconstruction

Maintaining reduction of the scapholunate interval after reconstruction can be difficult. The authors performed scapholunate reconstruction using tensionable suture anchors in 8 patients. The anchors provide a fixed cable that both fixes the graft, and reduces the scapholunate diastasis and maintains reduction. The flexor carpi radialis tendon graft stabilizes not only the volar scaphotrapezial ligament, and dorsal scapholunate ligament, but also the dorsal intercarpal and dorsal radiocarpal ligament. The Berger flap is closed using an ulnar advancement capsulodesis that further reinforces the dorsal intercarpal and dorsal radiocarpal ligament. The mean pain score improved from 5.8 to 2.1. Mean extension was 56° (91% of contralateral side), flexion 44° (70% of contralateral side), and grip strength was 41kg (95% of the contralateral side). The mean scapholunate angle was 71°, radiolunate angle 16° and scapholunate interval 3.0 mm. The cable augmented, quad ligament scapholunate ligament reconstruction offers theoretical advantages but long term follow up is required.

Comparing gene expression data from formalin-fixed, paraffin embedded tissues and qPCR with that from snap-frozen tissue and microarrays for modeling outcomes of patients with ovarian carcinoma

Background

Previously, we have used clinical and gene expression data from The Cancer Genome Atlas (TCGA) to model a pathway-based index predicting outcomes in ovarian carcinoma. This data were obtained from snap-frozen tissue measured with the Affymetrix U133 platform. In the current study, we correlate the data used to model with data derived from TaqMan qPCR both snap frozen and paraffin embedded (FFPE) samples.

Methods

To compare the effect of preservation methods on gene expression measured by qPCR, we assessed 18 patient and tumor sample matched snap-frozen and FFPE ovarian carcinoma samples. To compare gene measurement technologies, we correlated qPCR data from 10 patients with tumor sample matched snap-frozen ovarian carcinoma samples with the microarray data from TCGA. We normalized results to the average expression of three housekeeping genes. We scaled and centered the data for comparison to the Affymetrix output.

Results

For the 18 specimens, gene expression data obtained from snap-frozen tissue correlated highly with that from FFPE samples in our TaqMan assay (r > 0.82). For the 10 duplicate TCGA specimens, the reported microarray data correlated well (r = 0.6) with our qPCR data, and ranges of expression along pathways were similar.

Conclusions

Gene expression data obtained by qPCR from FFPE serous ovarian carcinoma samples can be used to assess in the pathway-based predictive model. The normalization procedures described control variations in expression, and the range calculated along a specific pathway can be interpreted for a patient’s risk profile.

Electronic supplementary material

The online version of this article (doi:10.1186/s12907-015-0017-1) contains supplementary material, which is available to authorized users.

Undoped accumulation-mode Si/SiGe quantum dots

We report on a quantum dot device design that combines the low disorder properties of undoped SiGe heterostructure materials with an overlapping gate stack in which each electrostatic gate has a dominant and unique function-control of individual quantum dot occupancies and of lateral tunneling into and between dots. Control of the tunneling rate between a dot and an electron bath is demonstrated over more than nine orders of magnitude and independently confirmed by direct measurement within the bandwidth of our amplifiers. The inter-dot tunnel coupling at the [Formula: see text] charge configuration anti-crossing is directly measured to quantify the control of a single inter-dot tunnel barrier gate. A simple exponential dependence is sufficient to describe each of these tunneling processes as a function of the controlling gate voltage.