Curation and expansion of the Human Phenotype Ontology for systemic autoinflammatory diseases improves phenotype-driven disease-matching

Introduction

Accurate and standardized phenotypic descriptions are essential in diagnosing rare diseases and discovering new diseases, and the Human Phenotype Ontology (HPO) system was developed to provide a rich collection of hierarchical phenotypic descriptions. However, although the HPO terms for inborn errors of immunity have been improved and curated, it has not been investigated whether this curation improves the diagnosis of systemic autoinflammatory disease (SAID) patients. Here, we aimed to study if improved HPO annotation for SAIDs enhanced SAID identification and to demonstrate the potential of phenotype-driven genome diagnostics using curated HPO terms for SAIDs.

Methods

We collected HPO terms from 98 genetically confirmed SAID patients across eight different European SAID expertise centers and used the LIRICAL (Likelihood Ratio Interpretation of Clinical Abnormalities) computational algorithm to estimate the effect of HPO curation on the prioritization of the correct SAID for each patient.

Results

Our results show that the percentage of correct diagnoses increased from 66% to 86% and that the number of diagnoses with the highest ranking increased from 38 to 45. In a further pilot study, curation also improved HPO-based whole-exome sequencing (WES) analysis, diagnosing 10/12 patients before and 12/12 after curation. In addition, the average number of candidate diseases that needed to be interpreted decreased from 35 to 2.

Discussion

This study demonstrates that curation of HPO terms can increase identification of the correct diagnosis, emphasizing the high potential of HPO-based genome diagnostics for SAIDs.

Measurement of Dark Ice-Ablator Mix in Inertial Confinement Fusion

We present measurements of ice-ablator mix at stagnation of inertially confined, cryogenically layered capsule implosions. An ice layer thickness scan with layers significantly thinner than used in ignition experiments enables us to investigate mix near the inner ablator interface. Our experiments reveal for the first time that the majority of atomically mixed ablator material is "dark" mix. It is seeded by the ice-ablator interface instability and located in the relatively cooler, denser region of the fuel assembly surrounding the fusion hot spot. The amount of dark mix is an important quantity as it is thought to affect both fusion fuel compression and burn propagation when it turns into hot mix as the burn wave propagates through the initially colder fuel region surrounding an igniting hot spot. We demonstrate a significant reduction in ice-ablator mix in the hot-spot boundary region when we increase the initial ice layer thickness.

In-depth characterisation of a cohort of individuals with missense and loss-of-function variants disruptingFOXP2

Background

Heterozygous disruptions ofFOXP2were the first identified molecular cause for severe speech disorder: childhood apraxia of speech (CAS), and yet few cases have been reported, limiting knowledge of the condition.

Methods

Here we phenotyped 28 individuals from 17 families with pathogenicFOXP2-only variants (12 loss-of-function, five missense variants; 14 males; aged 2 to 62 years). Health and development (cognitive, motor, social domains) were examined, including speech and language outcomes with the first cross-linguistic analysis of English and German.

Results

Speech disorders were prevalent (23/25, 92%) and CAS was most common (22/25, 88%), with similar speech presentations across English and German. Speech was still impaired in adulthood, and some speech sounds (eg, ‘th’, ‘r’, ‘ch’, ‘j’) were never acquired. Language impairments (21/25, 84%) ranged from mild to severe. Comorbidities included feeding difficulties in infancy (10/27, 37%), fine (13/26, 50%) and gross (13/26, 50%) motor impairment, anxiety (5/27, 19%), depression (6/27, 22%) and sleep disturbance (11/15, 44%). Physical features were common (22/27, 81%) but with no consistent pattern. Cognition ranged from average to mildly impaired and was incongruent with language ability; for example, seven participants with severe language disorder had average non-verbal cognition.

Conclusions

Although we identify an increased prevalence of conditions like anxiety, depression and sleep disturbance, we confirm that the consequences ofFOXP2dysfunction remain relatively specific to speech disorder, as compared with other recently identified monogenic conditions associated with CAS. Thus, our findings reinforce thatFOXP2provides a valuable entry point for examining the neurobiological bases of speech disorder.

OA30 Genetic analysis of whole exome sequencing in a cohort of children with refractory JIA reveals genetic risk factors for rare juvenile diseases

Introduction/Background

Juvenile idiopathic arthritis (JIA) encompasses a group of heterogeneous rheumatic diseases of childhood onset. JIA can result in long term disability and remission is the main goal of treatment. However refractory disease can occur, which is defined as the absence of response to a standard disease therapy. A genetic basis for refractory disease has yet to explored, where deleterious rare variants complicate diagnosis or treatment outcome. This study aimed to investigate, through genetic analysis, whether children with JIA that is refractory carry rare genetic risk factors in genes linked to monogenic diseases.

Description/Method

Whole exome sequencing of 99 children with JIA was performed with the Agilent SureSelect Human All ExonV6 kit. All quality control, variant filtering and annotation was performed in Varseq (version 2.2.1). Variants with a read depth <30 and genotype quality <80 were removed. Rarity and pathogenicity filters were then applied to remove variants with an allele frequency >1% (based on ExAC, gnomAD, gnomAD exome, NHLBI and 1KGp phase 3), classified as benign or likely benign on ClinVar, with a CADD PHRED score <15 and a REVEL score >0.7. Variants were annotated if they appeared in a gene from the primary immunodeficiency PanelApp (Martin et al., 2019), in a gene associated with an arthritis phenotype or in a gene that appeared on a paediatric monogenic gene list. The variants were then classified using ACMG guidelines (Richards et al., 2015) and benign, or likely benign, classified variants were removed.

Discussion/Results

A total of 470 variants were identified and we found that 20 out of the 99 children screened were heterozygous for at least one recognised variant in a gene linked to a monogenic disease. Five of these children carried more than one recognised variant linked to monogenic genes. Here we provide a number of illustrative examples: three genes, ADAR, ATP7B and MVK, were prioritised based on prior evidence of associated disease. The variant p.Pro193Ala (gnomAD allele frequency (GAD) 2.2x10-3) of ADAR has previously been deemed pathogenic in a homozygous or compound heterozygous state for Aicardi-Goutières syndrome. Adenosine deaminases (ADARs) catalyse the hydrolytic deamination of adenosine to inosine in dsRNA and is suggested to act as a suppressor of type 1 interferon-stimulated genes. Within ATP7B, two distinct variants were detected; p.Gln1142His (GAD 1.6x10-5) and p.Ile1148Thr (GAD 4.0x10-5) have previously been reported as pathogenic, in combination with a third variant, for Wilson’s disease and were carried by one individual in this cohort. ATP7B encodes copper-transporting ATPase 2, which supplies copper to ceruloplasmin. Variant p.Val377Ile (GAD 1.6x10-3) of MVK was detected in eight individuals in this cohort, interestingly five of these individuals also carried at least one HLA-DRB1 stop-gained variant. This MVK mutation has been confirmed as pathogenic in a homozygous or compound heterozygous state for mevalonate kinase deficiency. MVK converts mevalonic acid into mevalonate-5-phosphate in the cholesterol synthesis pathway. Additionally, two stop-gained loss of function HLA-DRB1 variants, p.Tyr107Ter and p.Gln125Ter, were detected in five and 20 individuals, respectively, in this cohort. HLA-DRB1 is a recognised susceptibility locus for JIA.

Key learning points/Conclusion

Screening of a cohort of 99 children with JIA that have refractory disease has revealed that individuals carry deleterious variants in genes linked to monogenic forms of disease. These results highlight that the genetic basis for refractory disease needs to be further investigated. Carrying additional genetic risk factors to disease may complicate disease outcome and genetic screening of children with refractory JIA may improve treatment outcome in the future.

POS0164 GENETIC ANALYSIS OF WHOLE EXOME SEQUENCING IN A COHORT OF CHILDREN WITH REFRACTORY JIA REVEALS GENETIC RISK FACTORS FOR RARE JUVENILE DISEASES

Background

Juvenile idiopathic arthritis (JIA) encompasses a group of heterogeneous rheumatic diseases of childhood onset. JIA can result in long term disability and remission is the main goal of treatment. However refractory disease can occur, which is defined as the absence of response to a standard disease therapy. A genetic basis for refractory disease has yet to be explored, where deleterious rare variants can complicate diagnosis or treatment outcome.

Objectives

To investigate, through genetic analysis, whether children with JIA that is refractory carry rare genetic risk factors in genes linked to monogenic diseases.

Methods

Whole exome sequencing of 99 children with JIA was performed with the Agilent SureSelect Human All ExonV6 kit. All quality control, variant filtering and annotation was performed in Varseq (version 2.2.1). Variants with a read depth <30 and genotype quality <80 were removed. Rarity and pathogenicity filters were then applied to remove variants with an allele frequency >1% (based on ExAC, gnomAD, gnomAD exome, NHLBI and 1KGp phase 3), classified as benign or likely benign on ClinVar, with a CADD PHRED score <15 and a REVEL score >0.7. Variants were annotated if they appeared in a gene from the primary immunodeficiency PanelApp (Martin et al., 2019), in a gene associated with an arthritis phenotype or in a gene that appeared on a paediatric monogenic gene list. The variants were then classified using ACMG guidelines (Richards et al., 2015) and benign, or likely benign, classified variants were removed.

Results

A total of 628 variants were identified and we found that 20 out of the 99 children screened were heterozygous for at least one recognised variant in a gene linked to a monogenic disease. Five of these children carried more than one recognised variant linked to monogenic genes. Here we provide a number of illustrative examples: three genes, ADAR, ATP7B and MVK, were prioritised based on prior evidence of associated disease. The variant p.Pro193Ala (gnomAD allele frequency (GAD) 2.2x10-3) of ADAR has previously been deemed pathogenic in a homozygous or compound heterozygous state for Aicardi-Goutières syndrome. Adenosine deaminases (ADARs) catalyse the hydrolytic deamination of adenosine to inosine in dsRNA and is suggested to act as a suppressor of type 1 interferon-stimulated genes. Within ATP7B, two distinct variants were detected; p.Gln1142His (GAD 1.6x10-5) and p.Ile1148Thr (GAD 4.0x10-5) have previously been reported as pathogenic, in combination with a third variant, for Wilson’s disease and were carried by one individual in this cohort. ATP7B encodes copper-transporting ATPase 2, which supplies copper to ceruloplasmin. Variant p.Val377Ile (GAD 1.6x10-3) of MVK was detected in eight individuals in this cohort, interestingly five of these individuals also carried at least one HLA-DRB1 stop-gained variant. This MVK mutation has been confirmed as pathogenic in a homozygous or compound heterozygous state for mevalonate kinase deficiency. MVK converts mevalonic acid into mevalonate-5-phosphate in the cholesterol synthesis pathway. Additionally, two stop-gained loss of function HLA-DRB1 variants, p.Tyr107Ter and p.Gln125Ter, were detected in five and 20 individuals, respectively, in this cohort. HLA-DRB1 is a recognised susceptibility locus for JIA.

Conclusion

Screening of a cohort of 99 children with JIA that have refractory disease has revealed that individuals carry deleterious variants in genes linked to monogenic forms of disease. These results highlight that the genetic basis for refractory disease needs to be further investigated. Carrying additional genetic risk factors to disease may complicate disease outcome and genetic screening of children with refractory JIA may improve treatment outcome in the future.

Acknowledgements

I would like to acknowledge the CLUSTER consortium.

Disclosure of Interests

None declared

Further delineation of phenotypic spectrum of SCN2A-related disorder

SCN2A-related disorders include intellectual disability, autism spectrum disorder, seizures, episodic ataxia, and schizophrenia. In this study, the phenotype-genotype association in SCN2A-related disorders was further delineated by collecting detailed clinical and molecular characteristics. Using previously proposed genotype-phenotype hypotheses based on variant function and position, the potential of phenotype prediction from the variants found was examined. Patients were identified through the Deciphering Developmental Disorders study and gene matching strategies. Phenotypic information and variant interpretation evidence were collated. Seventeen previously unreported patients and five patients who had been previously reported (but with minimal phenotypic and segregation data) were included (10 males, 12 females; median age 10.5 years). All patients had developmental delays and the majority had intellectual disabilities. Seizures were reported in 15 of 22 (68.2%), four of 22 (18.2%) had autism spectrum disorder and no patients were reported with episodic ataxia. The majority of variants were de novo. One family had presumed gonadal mosaicism. The correlation of the use of sodium channel-blocking antiepileptic drugs with phenotype or genotype was variable. These data suggest that variant type and position alone can provide some predictive information about the phenotype in a proportion of cases, but more precise assessment of variant function is needed for meaningful phenotype prediction.

141 New Guidelines to Reduce Unnecessary Blood Tests, Delayed Discharge and Costs Following Robot Assisted Radical Prostatectomy

Objectives

Routine postoperative blood tests (POBT) following robot assisted radical prostatectomy (RARP) are used to evaluate the impact of surgery on pre-existing co-morbidities and to detect early complications. This practice dates back to an era of open surgery, when blood loss and complication rates were higher. We propose new guidelines to improve the specificity of POBT.

Method

The cases of 1040 consecutive patients who underwent a primary or salvage RARP at two large tertiary urology centres in the United Kingdom were retrospectively reviewed to form new guidelines. The new guidelines were prospectively validated in a sample of 300 patients.

Results

Derivation Dataset: 3% and 5% had intra- and post-operative Clavien-Dindo complications, respectively. 15% had clinical concerns postoperatively. 0.9% required perioperative transfusion. 78% had routine blood tests without clinical concerns, none of whom developed a complication. 98% of complications were suspected by clinical judgement. 6% of patients had a discharge delay of ≥ 1 day due to delayed or incomplete blood tests. Validation Dataset: No significant difference existed in complication, clinical concern or transfusion rates between the derivation and validation datasets. Number of POBT requested reduced by 73% (p &lt; 0.001). The new guidelines improved POBT sensitivity for complications from 98% to 100% and specificity from 0% to 74%. Discharge delays reduced from 6% to 0% (p = 0.008). Cost savings were £178 per patient.

Conclusions

Postoperative complications and transfusion following RARP are rare. Routine POBT without clinical indication are unnecessary and inefficient. A guideline-based approach to POBT can reduce costs and optimise discharge without compromising patient safety or care.

283 Salvage Versus Primary Robot-Assisted Radical Prostatectomy: A Propensity-Matched Comparative Effectiveness Study from A High-Volume Tertiary Centre

Aim

Salvage Robot-Assisted Radical Prostatectomy (sRARP) is a potential treatment option for locally recurrent Prostate Cancer after non-surgical primary treatment. There are minimal data comparing outcomes between propensity-matched salvage and primary Robot-Assisted Radical Prostatectomy (RARP). We compare perioperative, oncological, and functional outcomes of sRARP with primary RARP and between sRARP post-whole and focal gland therapy.

Method

1:1 propensity-matched comparison of 146 sRARP with primary RARP from a cohort of 3,852 consecutive patients from a high-volume tertiary centre.

Results

There were no significant differences in patient characteristics between the salvage and primary RARP groups. Grade III-V Clavien-Dindo complication rates were 1.3% and 0% in the salvage and primary groups, respectively (p = 0.310). Median (IQR) follow-up was 16 (10,30) and 21 (13,33) months in the salvage and primary groups, respectively. BCR rates were 30.8% and 13.7% in the salvage and primary groups, respectively (p &lt; 0.001). Pad-free continence rates were 79.1% and 85.4% at two years in the salvage and primary groups, respectively (p = 0.160). ED rates were 95.2% and 77.4% in the salvage and primary groups, respectively (p &lt; 0.001). Comparing the whole gland and focal gland groups, BCR rates were 33.3% and 29.1%, respectively (p = 0.687), pad-free continence rates were 66% and 89.3%, respectively (p = 0.001), and ED rates were 98.3% and 93%, respectively (p = 0.145).

Conclusions

SRARP has similar perioperative but inferior oncological outcomes to primary RARP. Continence rates are similar to primary RARP, but potency is worse. Perioperative and oncological outcomes of sRARP after focal gland therapy are similar but continence outcomes are superior compared to sRARP after whole gland therapy.

O50 New guidelines to reduce unnecessary blood tests, delayed discharge and costs following robot assisted radical prostatectomy

Introduction

Routine postoperative blood tests (POBT) are used to evaluate the impact of surgery on pre-existing co-morbidities and to detect early complications. This practice dates back to an era of open surgery, when blood loss and complication rates were higher. We propose new guidelines to improve the specificity of POBT.

Method

The cases of 1040 consecutive patients who underwent a primary or salvage RARP at two large tertiary urology centres in the United Kingdom were retrospectively reviewed, and new guidelines were designed. The guidelines were prospectively validated in a cohort of 300 patients.

Result

Derivation Dataset 3% and 5% had intra- and post-operative Clavien-Dindo complications, respectively. 15% had clinical concerns postoperatively. 0.9% required perioperative transfusion. 78% had routine blood tests without clinical concerns, none of whom developed a complication. 98% of complications were suspected by clinical judgement. 6% of patients had a discharge delay of ≥ 1 days due to delayed or incomplete blood tests.

Validation Dataset No significant difference existed in complication, clinical concern or transfusion rates between the derivation and validation datasets. New guidelines improved sensitivity for complications from 98% to 100% and specificity from 0% to 74%. The number of blood tests requested reduced by 73% (P &lt; 0.001). Discharge delays reduced from 6% to 0% (P = 0.008). Cost savings were £178 per patient.

Conclusion

Postoperative complications and transfusion following RARP are rare. Routine POBT without clinical indication are unnecessary and inefficient. A guideline-based approach to POBT can reduce costs and optimise discharge without compromising patient safety or care.

Take-home Message

Routine postoperative blood tests following robot assisted radical prostatectomy are often unnecessary. A guideline-based approach can reduce costs and optimise patient care.

236 Novel Guidelines to Avoid Routine Blood Tests After Robotic Assisted Radical Prostatectomy (RARP)

Introduction

Patients undergoing RARP commonly require routine post-operative blood tests. This practice dates from an era of open surgery, with increased blood loss and complications. We aim to improve specificity of blood test requests with novel guidelines.

Method

1039 consecutive RARP patients at two tertiary urology centres in the UK were audited. Novel guidelines constructed based on risk stratified evidence from the initial audit were used to prospectively audit 133 patients.

Results

16% had clinical concerns post-operatively. 1% and 4% had an intra- and post-operative complication. Intra- or post-operative clinical judgement flagged post-operative complications in 99.9%. 80% had routine blood tests with no clinical concerns. 6% had delayed discharge due to delayed processing of blood tests. 0.9% received a peri-operative transfusion.

Re-Audit Novel guidelines reduced the number of blood tests requested from 100% to 36%. Specificity in diagnosing a complication improved from 0% to 67%. Discharge delays reduced from 6% to 0% and no post-operative complications were missed (sensitivity 100%).

Conclusions

Routine blood tests, without an indication, did not flag any additional post-operative complications. Blood transfusion is rare for RARP. Novel guidelines to request post-operative blood tests will reduce costs and discharge delays whilst maintaining appropriate patient safety and care.

The experiences of NHS hospital acute medicine departments in England during the first wave of the COVID-19 pandemic

We conducted a survey exploring the experiences of NHS hospital acute medicine services in England during the 1st wave of the COVID-19 pandemic. Responses were collected from 26th May to 8th July 2020. The results of 91 sites are presented. The total number of patients referred to the medical take for assessment and admitted from the medical take decreased from pre-pandemic levels compared to peak COVID-19 activity. The total number of acute medical beds decreased, however critical care beds increased by 162%. We report the median timeline from first admission of COVID-19 to when baseline critical care capacity was reached. We found regional variation across the results. These findings can assist healthcare leaders prepare for future pandemics.

Dual local drug delivery of vancomycin and farnesol for mitigation of MRSA infection in vivo - a pilot study

Surgical site infections after orthopaedic surgery using fracture fixation devices or endosseous implants create major surgical challenges with severe adverse effects, such as osteomyelitis. These infections are frequently caused by Staphylococcus aureus, often with high resistance to antibiotics, such as methicillin-resistant Staphylococcus aureus (MRSA). Due to the formation of impenetrable biofilms on implant surfaces, systemic antibiotic treatment has become exceedingly difficult. New solutions are pursued by combining several drugs using a controlled delivery system from specifically engineered implant surfaces. A sol-gel coating on titanium implants was previously developed with 20 wt % vancomycin and 30 wt % farnesol, with suppression of MRSA in vitro. The present study investigated the efficacy of sol-gel film coatings for controlled dual local delivery over 4 weeks utilising a rat infection model. The findings confirmed the viability of this new concept in vivo based on the differences observed between coatings containing vancomycin alone (SGV) and the dual-drug-containing coating with vancomycin and farnesol (SGVF). While both the SGVF and SGV coatings facilitated excellent preservation of the osseous microarchitecture, SGVF coating displayed a slightly higher potency for suppressing MRSA infiltration than SGV, in combination with a lower reactive bone remodelling activity, most likely by disturbing biofilm formation. The next step for advancing the concept of dual-drug delivery from sol-gel coatings to the clinic and confirming the promising effect of the SGVF coatings on reactive bone remodelling and suppressing MRSA infiltration is a study in a larger animal species with longer time points.

Techniques and Outcomes of Salvage Robot-Assisted Radical Prostatectomy (sRARP)

BACKGROUND

Salvage Robot-Assisted Radical Prostatectomy (sRARP) has been described as feasible treatment for the management of localised prostate cancer (PCa) recurrence after primary treatment. However, no large reports have published cancer and quality outcomes.

OBJECTIVE

To report perioperative, functional and oncologic outcomes of sRARP in patients with localised PCa recurrence.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively evaluated 106 patients with local recurrence eligible for sRARP.

SURGICAL PROCEDURE

Surgery was performed using the DaVinci Si system similar to the standard approach but with adaptation to the primary treatment.

MEASUREMENTS

Peri-operative outcomes included 90-day complication rate. Functional outcomes included rates of incontinence and erectile dysfunction. Oncological outcomes included tumour staging, margin rate and recurrence.

RESULTS AND LIMITATIONS

Primary treatment was High Intensity Focused Ultrasound (HIFU) in 59 (56%) patients, 27 (25%) radiotherapy, 10 (9%) seed brachytherapy, 8 (8%) solitary androgen deprivation therapy (ADT), one (1%) cryotherapy and one (1%) electroporation / Nanoknife. Median follow-up was 2.1 years. 90-day complication rate was 8%. At two years or more, 50% were fully continent and 33% were socially continent. Continence rates tended to be better after focal compared to whole-gland treatments. Erectile dysfunction was present in 95%. Positive surgical margin rate was 39%. Biochemical recurrence occurred in 13% and local or metastatic recurrence in 11%.

CONCLUSIONS

sRARP is technically more challenging but is a feasible option in high-volume centres for treatment of recurrent PCa. Patients should be counselled that functional outcomes are inferior to primary RARP. Adjustment of surgical technique according to the primary treatment is key for good surgical outcomes.

PATIENT SUMMARY

We report our experience with sRARP for the management of localised PCa recurrence after primary treatment. This represents a feasible approach with acceptable peri-operative complications and cancer outcomes. Functional outcomes are inferior to RARP in the primary setting.

Osteomimetic matrix components alter cell migration and drug response in a 3D tumour-engineered osteosarcoma model

Osteosarcoma management continues to lack the appropriate prognostic tools to assign personalised treatment. This leaves non-responders to standard care vulnerable to recurring disease and pulmonary metastases. Developing 3D in vitro disease models to serve as a test bed for personalised treatment is a promising approach to address this issue. This study describes the generation of 3D osteosarcoma models termed "tumouroids", which are geometrically compartmentalised to reproduce the bone cancer mass and its surrounding. Although the tumour microenvironment impacts osteosarcoma in many ways, this model focussed on interrogating the influence of a biomimetic matrix on tumour cell behaviour. The 3D matrix was supplemented with the bone-marrow proteins laminin, fibronectin and NuOss® bone granules. This led to increased invasion of osteosarcoma cell aggregates from within the bone-like matrix into the surrounding acellular bone marrow-like ECM. The presence of bone granules also yielded an atypical molecular profile of osteosarcoma cells, suggesting malignant metabolic reprogramming. Changes include decreased MMP-9 (p < 0.05) and increased PTEN (p < 0.05), MCP-1 (p < 0.01) and MCT-4 (p < 0.05) gene expression. This complex 3D biomimetic composition also changed cellular responses to doxorubicin, a common chemotherapeutic agent used to treat osteosarcoma, and reproduced key issues of in vivo treatment like drug penetrance and doxorubicin-induced bone toxicity. This work highlights the importance of a biomimetic matrix in 3D osteosarcoma models for both basic and translational research. STATEMENT OF SIGNIFICANCE: This study describes the generation of 3D osteosarcoma models termed "tumouroids", which are geometrically compartmentalised to reproduce the bone cancer mass and its environment. Utilising this novel model, specific parameters of osteosarcoma growth and invasion were investigated. Osteosarcoma cell lines proliferate at a slower rate, exhibit malignant metabolic reprogramming, and respond to drug intervention at lower concentrations of doxorubicin hydrochloride in matrix-complex compared to basic tumouroids. As such, this study provides evidence that the tumour microenvironment impacts osteosarcoma in many ways. The osteosarcoma tumouroid described herein may form the basis of a personalised-medicine strategy, which will allow the testing of drug effectiveness similar to that used for antibiotic selection for pathogenic bacteria.

Augmenting the osseointegration of endoprostheses using laser-sintered porous collars: an in vivo study

AIMS

Massive endoprostheses rely on extra-cortical bone bridging (ECBB) to enhance fixation. The aim of this study was to investigate the role of selective laser sintered (SLS) porous collars in augmenting the osseointegration of these prostheses.

MATERIALS AND METHODS

The two novel designs of porous SLS collars, one with small pores (Ø700 μm, SP) and one with large pores (Ø1500 μm, LP), were compared in an ovine tibial diaphyseal model. Osseointegration of these collars was compared with that of a clinically used solid, grooved design (G). At six months post-operatively, the ovine tibias were retrieved and underwent radiological and histological analysis.

RESULTS

Porous collars provided a significantly greater surface (p < 0.001) for the ingrowth of bone than the standard grooved design. Significantly greater extracortical pedicle formation was seen radiologically around the grooved design (length p = 0.002, thickness p < 0.001, surface area p = 0.002) than around the porous collars. However, the ingrowth of bone occurred from the transection site into the porous structure of both types of collar. A fivefold increase in integration was seen with the SP and a threefold increase in the LP design when compared with G (p < 0.001).

CONCLUSION

SLS porous collars allow the direct ingrowth of more bone and are better than current designs which rely on surface ongrowth and ECBB. Cite this article: Bone Joint J 2017;99-B:276-82.

Parathyroid hormone 1-34 and skeletal anabolic action: The use of parathyroid hormone in bone formation

Intermittently administered parathyroid hormone (PTH 1-34) has been shown to promote bone formation in both human and animal studies. The hormone and its analogues stimulate both bone formation and resorption, and as such at low doses are now in clinical use for the treatment of severe osteoporosis. By varying the duration of exposure, parathyroid hormone can modulate genes leading to increased bone formation within a so-called 'anabolic window'. The osteogenic mechanisms involved are multiple, affecting the stimulation of osteoprogenitor cells, osteoblasts, osteocytes and the stem cell niche, and ultimately leading to increased osteoblast activation, reduced osteoblast apoptosis, upregulation of Wnt/β-catenin signalling, increased stem cell mobilisation, and mediation of the RANKL/OPG pathway. Ongoing investigation into their effect on bone formation through 'coupled' and 'uncoupled' mechanisms further underlines the impact of intermittent PTH on both cortical and cancellous bone. Given the principally catabolic actions of continuous PTH, this article reviews the skeletal actions of intermittent PTH 1-34 and the mechanisms underlying its effect.

CITE THIS ARTICLE

L. Osagie-Clouard, A. Sanghani, M. Coathup, T. Briggs, M. Bostrom, G. Blunn. Parathyroid hormone 1-34 and skeletal anabolic action: The use of parathyroid hormone in bone formation. Bone Joint Res 2017;6:14-21. DOI: 10.1302/2046-3758.61.BJR-2016-0085.R1.

Knee surgery and its evidence base

INTRODUCTION

Evidence driven orthopaedics is gaining prominence. It enables better management decisions and therefore better patient care. The aim of our study was to review a selection of the leading publications pertaining to knee surgery to assess changes in levels of evidence over a decade.

METHODS

Articles from the years 2000 and 2010 in The Knee, the Journal of Arthroplasty, Knee Surgery, Sports Traumatology, Arthroscopy, the Journal of Bone and Joint Surgery (American Volume) and the Bone and Joint Journal were analysed and ranked according to guidelines from the Centre for Evidence-Based Medicine. The intervening years (2003, 2005 and 2007) were also analysed to further define the trend.

RESULTS

The percentage of high level evidence (level I and II) studies increased albeit without reaching statistical significance. Following a significant downward trend, the latter part of the decade saw a major rise in levels of published evidence. The most frequent type of study was therapeutic.

CONCLUSIONS

Although the rise in levels of evidence across the decade was not statistically significant, there was a significant drop and then rise in these levels in the interim. It is therefore important that a further study is performed to assess longer-term trends. Recent developments have made clear that high quality evidence will be having an ever increasing influence on future orthopaedic practice. We suggest that journals implement compulsory declaration of a published study's level of evidence and that authors consider their study designs carefully to enhance the quality of available evidence.

Physical functioning, pain and quality of life after amputation for musculoskeletal tumours

Patients who have limb amputation for musculoskeletal tumours are a rare group of cancer survivors. This was a prospective cross-sectional survey of patients from five specialist centres for sarcoma surgery in England. Physical function, pain and quality of life (QOL) outcomes were collected after lower extremity amputation for bone or soft-tissue tumours to evaluate the survivorship experience and inform service provision.

Of 250 patients, 105 (42%) responded between September 2012 and June 2013. From these, completed questionnaires were received from 100 patients with a mean age of 53.6 years (19 to 91). In total 60 (62%) were male and 37 (38%) were female (three not specified). The diagnosis was primary bone sarcoma in 63 and soft-tissue tumour in 37. A total of 20 tumours were located in the hip or pelvis, 31 above the knee, 32 between the knee and ankle and 17 in the ankle or foot. In total 22 had hemipelvectomy, nine hip disarticulation, 35 transfemoral amputation, one knee disarticulation, 30 transtibial amputation, two toe amputations and one rotationplasty. The Toronto Extremity Salvage Score (TESS) differed by amputation level, with poorer scores at higher levels (p < 0.001). Many reported significant pain. In addition, TESS was negatively associated with increasing age, and pain interference scores. QOL for Cancer Survivors was significantly correlated with TESS (p < 0.001). This relationship appeared driven by pain interference scores.

This unprecedented national survey confirms amputation level is linked to physical function, but not QOL or pain measures. Pain and physical function significantly impact on QOL. These results are helpful in managing the expectations of patients about treatment and addressing their complex needs.

Cite this article: Bone Joint J 2015;97-B:1284–90.

Management of vesico-urethral anastomosis disruption after radical prostatectomy

BACKGROUND/AIMS

Disruption of vesico-urethral anastomosis is a complication which can have dramatic results on the post-operative quality of life of the patient who has had radical prostatectomy. We present our own experience of this complication and discuss the aetiology, treatment and outcome with reference to published data on the subject. We suggest means by which to prevent this complication.

METHODS

A retrospective notes review was performed on our own series of 4 patients with disruption of the vesico-urethral anastomosis after radical prostatectomy. A literature review was performed on the subject.

RESULTS

We explore ways of managing this complication based on our own series and the published data. We find that urethral disruption is most often significant if a blind attempt at catheter reinsertion by an inexperienced doctor is made. Replacement over a guide-wire using a flexible cystoscope is reasonable provided a significant distraction injury has not already occurred.

CONCLUSIONS

Replacement of the urethral catheter which has fallen out/is blocked should be done using cystoscopic guidance, if it needs to be replaced at all. We find that outcome, in terms of urinary continence, is better if, having sustained a significant disruption of the anastomosis, immediate surgical revision of anastomosis is performed.

A correlation between the timing of biopsy after autologous chondrocyte implantation and the histological appearance

Autologous chondrocyte implantation is an option in the treatment of full-thickness chondral or osteochondral injuries which are symptomatic. The goal of surgery and rehabilitation is the replacement of damaged cartilage with hyaline or hyaline-like cartilage, producing improved levels of function and preventing early osteoarthritis. The intermediate results have been promising in terms of functional and clinical improvement.

Our aim was to explore the hypothesis that the histological quality of the repair tissue formed after autologous chondrocyte implantation improved with increasing time after implantation.

In all, 248 patients who had undergone autologous chondrocyte implantation had biopsies taken of the repair tissue which then underwent histological grading. Statistical analysis suggested that with doubling of the time after implantation the likelihood of a favourable histological outcome was increased by more than fourfold (p < 0.001).

A comparison of augmentation techniques for reconstruction of the extensor mechanism following proximal tibial replacement in an experimental animal model

We used an in vivo model to assess the use of an autogenous cancellous bone block and marrow graft for augmenting tendon reattachment to metallic implants. We hypothesised that augmentation of the tendon-implant interface with a bone block would enable retention of the graft on the implant surface, enhance biological integration, and result in more consistent functional outcomes compared with previously reported morcellised graft augmentation techniques.

A significant improvement in functional weight-bearing was observed between six and 12 weeks. The significant increase in ground reaction force through the operated limb between six and 12 weeks was greater than that reported previously with morcellised graft augmented reconstructions. Histological appearance and collagen fibre orientation with bone block augmentation more closely resembled that of an intact enthesis compared with the morcellised grafting technique. Bone block augmentation of tendon-implant interfaces results in more reliable functional and histological outcomes, with a return to pre-operative levels of weight-bearing by 24 weeks.

Clinical and molecular phenotype of Aicardi-Goutieres syndrome

Aicardi-Goutieres syndrome (AGS) is a genetic encephalopathy whose clinical features mimic those of acquired in utero viral infection. AGS exhibits locus heterogeneity, with mutations identified in genes encoding the 3'-->5' exonuclease TREX1 and the three subunits of the RNASEH2 endonuclease complex. To define the molecular spectrum of AGS, we performed mutation screening in patients, from 127 pedigrees, with a clinical diagnosis of the disease. Biallelic mutations in TREX1, RNASEH2A, RNASEH2B, and RNASEH2C were observed in 31, 3, 47, and 18 families, respectively. In five families, we identified an RNASEH2A or RNASEH2B mutation on one allele only. In one child, the disease occurred because of a de novo heterozygous TREX1 mutation. In 22 families, no mutations were found. Null mutations were common in TREX1, although a specific missense mutation was observed frequently in patients from northern Europe. Almost all mutations in RNASEH2A, RNASEH2B, and RNASEH2C were missense. We identified an RNASEH2C founder mutation in 13 Pakistani families. We also collected clinical data from 123 mutation-positive patients. Two clinical presentations could be delineated: an early-onset neonatal form, highly reminiscent of congenital infection seen particularly with TREX1 mutations, and a later-onset presentation, sometimes occurring after several months of normal development and occasionally associated with remarkably preserved neurological function, most frequently due to RNASEH2B mutations. Mortality was correlated with genotype; 34.3% of patients with TREX1, RNASEH2A, and RNASEH2C mutations versus 8.0% RNASEH2B mutation-positive patients were known to have died (P=.001). Our analysis defines the phenotypic spectrum of AGS and suggests a coherent mutation-screening strategy in this heterogeneous disorder. Additionally, our data indicate that at least one further AGS-causing gene remains to be identified.

Kystes anévrismaux des phalanges et des métacarpiens. À propos de six cas et revue de la littérature

Aneurysmal bone cysts arising from tubular bones of the hand occur very rarely and require particular diagnostic and therapeutic management techniques. The authors report the diagnostic and surgical management of a monocentric case series of six aneurysmal bone cysts involving the phalangeal and metacarpal bones. In addition to hightlighting the use of diagnostic MRI and biopsy prior to surgical intervention, the authors describe the favourable outcome of curetage with and without the use of bone graft. An aggressive treatment approach such as cryotherapy or resection with reconstruction should only be used in cases when the articular surface is involved, when full bone invasion of the phalanx or metacarpal has occurred, or in case of more than one recurrence.

Development of a clinically feasible molecular assay to predict recurrence of Dukes’ B colon cancer

20110

Background: The 5-year survival rate of Dukes’ B colon cancer patients is approximately 75%. In our earlier genome-wide measurements of gene expression we have identified a 23-gene signature that sub-classifies Dukes’ B tumors and may provide better means of risk assessment on an individual basis for these colon cancer patients. The aim of this study is to validate this gene signature in an independent and more diverse group of patients, and further develop this prognostic signature into a clinical feasible test using formalin-fixed paraffin-embedded (FFPE) tissue samples. Methods: Using Affymetrix U133a GeneChip we analyzed the expression of the 23 genes in total RNA of frozen tumor samples from 123 Dukes’ B patients who did not receive adjuvant systemic treatment. Furthermore, we developed a quantitative RT-PCR assay for this gene signature in order to perform the test with standard clinical FFPE samples. Results: In the independent validation set of 123 patients, the gene signature proved to be informative in identifying patients who would develop distant metastasis (hazard ratio, HR 2.56; 95% confidence interval CI, 1.01–6.48), even when corrected for the traditional prognostic factors in multivariate analysis (HR, 2.73; 95% CI, 0.97–7.73). The RT-PCR assay developed for this gene signature was also validated in an independent set of 114 patients as a strong prognostic factor for the development of distant recurrence (HR, 6.38; 95% CI, 2.88–14.2) in univariate analysis and in multivariate analysis (HR, 13.3; 95% CI, 5.13–34.4). Conclusions: Our data provide not only a validation of the pre-defined prognostic gene signature for Dukes’ B colon cancer patients but also a clear feasibility of testing the gene signature using RT-PCR with standard FFPE specimens. The ability of such a test to identify patients that have an unfavorable outcome demonstrates potential clinical importance that could lead clinicians to choose a more aggressive therapeutic option for the high-risk patients.

[Table: see text]

Retraining: Can do, will do? A practical guide to process and pitfalls

This article reports the lessons learnt from a period of retraining and from discussion with others who have been involved in a similar process. The conclusions are that retraining should only be undertaken once there is full agreement between all parties involved that it is necessary and feasible. There must also be agreement in advance of the criteria which will constitute successful retraining, and the actions which will be taken to ensure the rapid return of the retrainee to the type of practice which is being offered and has been accepted. The process of retraining requires especially close supervision and is very stressful for the retrainee. It is likely that this should only be undertaken in units specially staffed and funded to accommodate this type of work.

A histomorphological study of tendon reconstruction to a hydroxyapatite-coated implant: regeneration of a neo-enthesis in vivo

The attachment of tendons and ligaments to massive endoprostheses remains a clinical challenge due to the difficulty in achieving a soft tissue implant interface with a mechanical strength sufficient to transmit the forces necessary for locomotion. We have used an in vivo animal model to study patellar tendon attachment to an implant surface. The interface generated when the patellar tendon was attached to a hydroxyapatite (HA) coated implant was examined using light microscopy and a quantitative histomorphological analysis was performed. In the Autograft Group, the interface was augmented with autogenous cancellous bone and marrow graft, and at six weeks an indirect-like insertion was observed. At twelve weeks, the interface was observed to be a layered neo-enthesis, whose morphology was similar to a normal direct tendon insertion. In the HA Group, the tendon-implant interface was not augmented, and the implant was enveloped by a dense collagenous fibrous tissue. This study shows that a tendon-implant neo-enthesis can develop in situ by employing a suitable implant surface in association with biological augmentation.

Single center experience of a new intensive induction therapy for ewing's family of tumors: feasibility, toxicity, and stem cell mobilization properties

PURPOSE

To examine the feasibility, tolerability, and toxicity of an intensified induction regimen (vincristine, ifosfamide, doxorubicin, and etoposide [VIDE]) in patients with newly diagnosed Ewing's family of tumors (EFT); to assess ability to maintain dose-intensity, and predictability of peripheral-blood stem cell mobilization.

PATIENTS AND METHODS

Thirty patients were treated with vincristine 1.4 mg/m2 (maximum 2 mg) on day 1, doxorubicin 20 mg/m2, ifosfamide 3 g/m2 plus mesna and etoposide 150 mg/m2 on days 1 to 3. Cycles were given every 21 days for up to six cycles.

RESULTS

One-hundred and seventy cycles of VIDE were given. The median treatment interval was 21 days (21 to 42) and nadir count: hemoglobin 8.3 (6.3 to 11.9), neutrophils 0.045 (0.0 to 2.1), and platelets 45 (3 to 343). There were 96 episodes of infection requiring hospitalization (56%). Growth factor support reduced infectious complications by 34%. Etoposide dose was reduced, or omitted, in 24% of cycles. Four patients did not complete six cycles due to unacceptable toxicity and one patient progressed on treatment. Twenty patients underwent peripheral-blood stem cell harvesting, 15 after cycle 3, and five after cycle 4. Median CD34+ yield was 4.6 x 106/kg per patient (1.8 to 14.5). Overall response to treatment, measured in 24 patients, was 88%. Seven of 11 patients undergoing surgery achieved greater than 90% necrosis of tumor (64%).

CONCLUSION

VIDE is an effective induction regimen with substantial but acceptable toxicity that allows predictable mobilization of stem cells. Maintenance of dose-intensity is feasible in the majority of patients. Growth factors play a role in maintaining dose-intensity and reduce infectious complications.

Transcriptional repression by neuron-restrictive silencer factor is mediated via the Sin3-histone deacetylase complex

A large number of neuron-specific genes characterized to date are under the control of negative transcriptional regulation. Many promoter regions of neuron-specific genes possess the repressor element repressor element 1/neuron-restrictive silencing element (RE1/NRSE). Its cognate binding protein, REST/NRSF, is an essential transcription factor; its null mutations result in embryonic lethality, and its dominant negative mutants produce aberrant expression of neuron-specific genes. REST/NRSF acts as a regulator of neuron-specific gene expression in both nonneuronal tissue and developing neurons. Here, we shown that heterologous expression of REST/NRSF in Saccharomyces cerevisiae is able to repress transcription from yeast promoters engineered to contain RE1/NRSEs. Moreover, we have taken advantage of this observation to show that this repression requires both yeast Sin3p and Rpd3p and that REST/NRSF physically interacts with the product of the yeast SIN3 gene in vivo. Furthermore, we show that REST/NRSF binds mammalian SIN3A and HDAC-2 and requires histone deacetylase activity to repress neuronal gene transcription in both nonneuronal and neuronal cell lines. We show that REST/NRSF binding to RE1/NRSE is accompanied by a decrease in the acetylation of histones around RE1/NRSE and that this decrease requires the N-terminal Sin3p binding domain of REST/NRSF. Taken together, these data suggest that REST/NRSF represses neuronal gene transcription by recruiting the SIN3/HDAC complex.

Attitudes of carers and the elderly occupants of residential homes to antimicrobial chewing gum as an aid to oral health

OBJECTIVE

The aim of this study was to investigate the attitudes of elderly residents to using an antimicrobial chewing gum as an aid to oral health, and the opinion of their carers on such a procedure.

DESIGN

A cross-sectional, multi-centre survey using a structured interview/questionnaire conducted with elderly residents and their carers.

SETTING

In January 1998, 9 residential/nursing homes were chosen at random from all the homes in West Hertfordshire, 207 residents were asked to chew two pieces of gum twice daily for 7 days.

SUBJECTS

The participants, 148 women and 59 men, were aged between 53-100 years (mean age 82.23 +/- 9.62 years). 47 carers, all female, were involved in distributing and collecting the gum.

RESULTS

122 residents (58.9%) were edentulous and 85 (41%) of the participants were partially dentate. Of those with teeth 23 (27%) had 21 teeth or more. 73 (35.2%) residents found that chewing the gum was difficult with 37 (17.9%) of this group being unable to chew (P < 0.0001 for those residents with no teeth/dentures or dentures unopposed by teeth or other dentures). 32 (18.6%) subjects disliked the flavour of the gum. Of the 170 residents who chewed the gum 99 (57.2%) found it reduced oral dryness and 78 (45.1%) reported it made their mouth feel healthy. 34 (53.6%) of the dentate and 47 (40.9%) of the edentate residents wished to keep using the gum (P < 0.05). 35 (74.5%) of the carers found it easy to distribute the gum and 29 (61.7%) thought that chewing gum was an acceptable method of maintaining oral health for residents.

CONCLUSION

The antimicrobial gum investigated in this study was acceptable to many elderly occupants and their carers, significantly improving perceived oral health and oral dryness of residents.

A computer generated interactive transurethral prostatic resection simulator

PURPOSE

We developed a computer generated model of the prostate gland and an interactive simulator for use in training urologists in transurethral resection of the prostate.

MATERIALS AND METHODS

Software was developed on a standard personal computer which allowed images of the lumen of the prostatic urethra and resectoscope loop to be generated and interacted with using a magnetic position sensor input device attached to a dummy resectoscope.

RESULTS

An anatomically accurate computer model of the prostate was generated at low cost which permitted user interaction and which simulated key elements of transurethral prostatic resection.

CONCLUSIONS

Although not a substitute for learning transurethral prostatic resection on patients, the simulator enabled the user to become familiar with the technique of transurethral prostatic resection in the absence of time constraints and without risk to patients. The simulator may become an important tool in training and assessing surgeon competency, and may reduce the costs of training. Further development is needed to refine the transurethral prostatic resection simulator and expand its surgical range.

Hazard of ionizing radiation to trauma surgeons: reducing the risk

A study aimed to establish the level of radiation exposure to orthopaedic surgeons involved in the care of injured patients; parts of the body most at risk, and to establishing whether surgeon control of X-ray image intensification reduced the risk. This was conducted on five orthopaedic surgeons regularly involved in musculoskeletal care. Radiation dosage (in millisieverts (mSv) to the body, neck, eyes and hands, was measured by means of dosimeters applied to these areas, before and after surgeon-controlled use of X-ray image intensification. Although all doses measured were within current safety guidelines (1.25 mSv total body dose/month, 3.75 mSv eye dose/month and 12.5 mSv extremity dose/month), the hands were most at risk (maximum recorded dosage 3.95 mSv/month). Control by the surgeons of X-ray image intensification significantly reduced exposure of the hands (P < 0.05).

Notes: a suitable case for audit

The increasing emphasis on management responsibilities and audit led us to investigate the state of surgical notes in our hospital. Twelve criteria were evaluated regarding information that should be contained in the notes and the absence of this important information was documented. Deficiencies were revealed in all criteria selected. Until hospital patients files are well kept and maintained, retrospective audit whether financial or medical will not be valid. A significant injection of resources is required to redress the situation. Hospitals which have not carried out detailed studies into the contents of their notes need to do so as a matter of urgency.

Patients' satisfaction with care received in teaching settings

Voluntary psychiatric patients (N=118) on a teaching ward were asked to identify their medical personnel and rate their satisfaction with the care they received. The patients were proficient in distinguishing between psychiatrists, psychiatric residents, and medical students and were highly satisfied with the care they received. Patients over 35 were better at identifying residents than younger patients and also rated the quality of care pro-vided by psychiatrists more highly. Patients with adjustment reaction with depressed mood rated the quality of care provided by psychiatrists lower than did patients with major depression, bipolar affective disorder, or psychosis. Female patients rated their psychiatrists more highly than did male patients.

Lipolysis of serum-activated triacylglycerol at the surface of J774.1 macrophages. A biochemical--electron-microscopic study

Cultured mouse (J774.1) macrophages accumulated triacylglycerol, but no cholesteryl ester or cholesterol, when incubated in albumin-poor medium with serum-activated lipid particles containing 84 mol% trioleoylglycerol and 9 mol% cholesteryl oleate. Accumulation of triacylglycerol by cells was associated with hydrolysis of particulate triacylglycerol to fatty acid and glycerol. Both acyl and glyceryl moieties of particulate triacylglycerol were recovered in cellular triacylglycerol with a molar ratio of 3.6. The cells also accumulated fatty acid and monoacylglycerol. Whether acylglycerol was taken up as a single molecular species, such as monoacylglycerol, or as several species can not be determined by the present findings. Macrophages incubated with lipid particles for 24 h had many lipid particles attached to cell surfaces and numerous intracellular lipid droplets. The surface film of attached particles was continuous with the outer leaflet of plasma membrane of the cells. Particles partially depleted of core triacylglycerol and collapsed surface films were found attached to surfaces of macrophages. There was no morphological evidence that lipid particles were taken up intact by cells, through endocytosis or phagocytosis. Macrophages incubated with lipid particles also contained intracellular lamellar structures. They varied in size and shape, and were located in the periphery of cells, sometimes near lipid droplets and endoplasmic reticulum. Only 3% of the lamellar structures were associated with lysosomes, indicating they probably were not of lysosomal origin. Lipid particles attached to cells decreased in size and number, and lamellar structures developed at the surface of particles, or replaced the particles, when glutaraldehyde-fixed specimens were incubated at 25 degrees C, demonstrating lipolytic activity at the surface of macrophages. Our findings suggest that particulate triacylglycerol was hydrolyzed by lipoprotein lipase at the surface of macrophages, and that fatty acid and monoacylglycerol formed by lipolysis were transported directly into the cells to be reesterified. When lipolytic products were taken up faster than they could be utilized, they accumulated as lamellar structures in the cells.