Venetoclax, alone and in combination with the BH3 mimetic S63845, depletes HIV-1 latently infected cells and delays rebound in humanized mice

HIV-1 persists indefinitely in people living with HIV (PLWH) on antiretroviral therapy (ART). If ART is stopped, the virus rapidly rebounds from long-lived latently infected cells. Using a humanized mouse model of HIV-1 infection and CD4+ T cells from PLWH on ART, we investigate whether antagonizing host pro-survival proteins can prime latent cells to die and facilitate HIV-1 clearance. Venetoclax, a pro-apoptotic inhibitor of Bcl-2, depletes total and intact HIV-1 DNA in CD4+ T cells from PLWH ex vivo. This venetoclax-sensitive population is enriched for cells with transcriptionally higher levels of pro-apoptotic BH3-only proteins. Furthermore, venetoclax delays viral rebound in a mouse model of persistent HIV-1 infection, and the combination of venetoclax with the Mcl-1 inhibitor S63845 achieves a longer delay in rebound compared with either intervention alone. Thus, selective inhibition of pro-survival proteins can induce death of HIV-1-infected cells that persist on ART, extending time to viral rebound.

Adaptation of Droplet Digital PCR-Based HIV Transcription Profiling to Digital PCR and Association of HIV Transcription and Total or Intact HIV DNA

In most people living with HIV (PLWH) on effective antiretroviral therapy (ART), cell-associated viral transcripts are readily detectable in CD4+ T cells despite the absence of viremia. Quantification of HIV RNA species provides insights into the transcriptional activity of proviruses that persist in cells and tissues throughout the body during ART ('HIV reservoir'). One such technique for HIV RNA quantitation, 'HIV transcription profiling', developed in the Yukl laboratory, measures a series of HIV RNA species using droplet digital PCR. To take advantage of advances in digital (d)PCR, we adapted the 'HIV transcription profiling' technique to Qiagen's dPCR platform (QIAcuity) and compared its performance to droplet digital (dd)PCR (Bio-Rad QX200 system). Using RNA standards, the two technologies were tested in parallel and assessed for multiple parameters including sensitivity, specificity, linearity, and intra- and inter-assay variability. The newly validated dPCR assays were then applied to samples from PLWH to determine HIV transcriptional activity relative to HIV reservoir size. We report that HIV transcriptional profiling was readily adapted to dPCR and assays performed similarly to ddPCR, with no differences in assay characteristics. We applied these assays in a cohort of 23 PLWH and found that HIV reservoir size, based on genetically intact proviral DNA, does not predict HIV transcriptional activity. In contrast, levels of total DNA correlated with levels of most HIV transcripts (initiated, proximally and distally elongated, unspliced, and completed, but not multiply spliced), suggesting that a considerable proportion of HIV transcripts likely originate from defective proviruses. These findings may have implications for measuring and assessing curative strategies and clinical trial outcomes.

Adaptation of the intact proviral DNA assay to a nanowell-based digital PCR platform

Quantification of intact proviruses is a critical measurement in HIV cure studies both in vitro and in vivo. The widely adopted 'intact proviral DNA assay' (IPDA), designed to discriminate and quantify genetically intact HIV proviruses based on detection of two HIV sequence-specific targets, was originally validated using Bio-Rad's droplet digital PCR technology (ddPCR). Despite its advantages, ddPCR is limited in multiplexing capability (two-channel) and is both labor- and time intensive. To overcome some of these limitations, we utilized a nanowell-based digital PCR platform (dPCR, QIAcuity from Qiagen) which is a fully automated system that partitions samples into nanowells rather than droplets. In this study we adapted the IPDA assay to the QIAcuity platform and assessed its performance relative to ddPCR. The dPCR could differentiate between intact, 5' defective and 3' defective proviruses and was sensitive to single HIV copy input. We found the intra-assay and inter-assay variability was within acceptable ranges (with coefficient of variation at or below 10%). When comparing the performance of the IPDA in ex vivo CD4⁺ T cells from people with HIV on antiretroviral therapy, there was a strong correlation in the quantification of intact (rs = 0.93; p < 0.001) and 3' defective proviruses (rs = 0.96; p < 0.001) with a significant but less strong correlation for 5' defective proviruses (rs = 0.7; p = 0.04). We demonstrate that the dPCR platform enables sensitive and accurate quantification of genetically intact and defective proviruses similar to the ddPCR system but with greater speed and efficiency. This flexible system can be further optimized in the future, to detect up to 5 targets, enabling a more precise detection of intact and potentially replication-competent proviruses.

73 Computed Tomography Imaging to Determine Reduction in Intracrainal Pressure Before & After Posterior Vault Expansion in Apert Syndrome

Introduction

Apert syndrome is an autosomal dominant malformation syndrome, accounting for 4.5% of all craniosynostoses. Raised intracranial pressure (ICP) in Apert syndrome has a multifactorial aetiology, with an incidence of up to 45% if left untreated [1, 2]. Raised ICP can be determined clinically, with non-invasive and invasive methods. In this study, we want to assess whether the use of CT scans is reliable in identifying changes in ICP.

Method

Pre and postoperative CT scans for 13 Apert syndrome patients who had posterior vault expansion were assessed and graded for severity of intracranial pressure (ICP). The grading system used was departmental specific and the assessment was carried out by a single clinician on different brain structures. This process was repeated on the same patients, using the same CT scans, 4 months later to determine consistency and repeatability. The relationship between the pre and postoperative scans was explored using the chi squared test. Intra-observer variability was assessed using Kappa statistics [SS1].

Results

There was no statistically significant difference between the pre and postoperative CT scan grading. Across instances, only one assessed structure had a p-value &lt;0.05. The Kappa interobserver reliability test did not identify a strong agreement in the comparison of the two instances of data analysis.

Conclusions

Assessment of CT scans is not a reliable method to determine changes in intracranial pressure in Apert syndrome patients who have had a posterior vault expansion.

1173 Airway and Breathing Problems in Pierre Robin Sequence: A Systematic Review Protocol

Aim

The primary aim is to systematically review the specific airway and/or breathing problems which have been reported in Pierre Robin Sequence (PRS). Secondary aims are to understand the prevalence and severity of these airway and breathing problems, and options for screening, assessment, and monitoring.

Method

A search strategy will be designed to search the following databases: MEDLINE, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials(CENTRAL) including a grey literature search, to identify publications on airway and/or breathing problems in Pierre Robin Sequence patients. Airway or breathing problems to be included are defined upper airway conditions (e.g., sleep apnoea) or clinically or objectively defined airway/breathing problems (e.g., increased respiratory rate, polysomnography). Screening will exclude non-English articles, abstracts, letters, editorials, expert opinions and breathing problems not anatomically related to craniofacial underdevelopment.

Results

This systematic review has been successfully registered on the PROSPERO International Prospective Register of Systematic Reviews (CRD42020210572)

Conclusions

PRS is a rare craniofacial condition which presents at birth, consisting of micrognathia, glossoptosis and airway problems, and is usually, but not always, associated with a cleft palate. There is no consensus on the type of airway problems that affect patients with PRS. The findings of this systematic review will help to develop a consensus on the airway and breathing problems in PRS and options for assessment and monitoring of the airway and breathing problem. This data may also contribute to development of a standardized guideline for management of airway and breathing problems in PRS.

Parametrizing the genioplasty: a biomechanical virtual study on soft tissue behavior

Purpose

Sliding genioplasty is used to surgically correct a retruded or misaligned chin: in this procedure, an osteotomy is performed and the bony segment is repositioned. In this study we investigate the effect of surgical parameters (bony segment movement, osteotomy design) on postop soft tissue changes in a patient cohort.

Methods

Seven patients were retrospectively recruited. Cone beam computed tomography data were obtained and soft tissue and bone shape reconstructions were performed. 3D models were created and surgical cuts were replicated according to postop scans. Each model was imported in ANSYS 2019R1 (Ansys Inc, USA) for simulation: the effect of variation in osteotomy plane as well as extent of bony segment movement were assessed by means of design of experiment: surgical parameters were varied in a surgically acceptable range and the soft tissue predictions were evaluated as displacement output of five craniometric landmarks.

Results

Simulation results show the overall changes of the lower third of the face are sensitive to changes in horizontal and vertical displacement of the bony segment as well as segment rotation. No significant changes in the soft tissue response were to attribute to the osteotomy design.

Conclusions

Our results are consistent with experimental findings reported in the literature: when planning genioplasty in orthognathic surgery, particular focus on the segment movement (horizontal translation, vertical translation and rotation), rather than on the design of the osteotomy itself, should be considered.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

0143 Vigilance Declines Following Sleep Deprivation are Associated with Two Previously Identified Dynamic Connectivity States

Introduction

Dynamic functional connectivity (DFC) analysis of resting-state fMRI data has been successfully used to track fluctuations in arousal in the human brain. Changes in DFC have also been reported with acute sleep deprivation. Here, we demonstrate that dynamic connectivity states (DCS) previously related to arousal are reproducible, and are associated with individual differences in sustained attention declines after one night of total sleep deprivation.

Methods

32 participants underwent two counterbalanced resting-state fMRI scans: during rested wakefulness (RW) and following total sleep deprivation (SD). They also completed the Psychomotor Vigilance Test (PVT), a sustained attention task that is highly sensitive to the effects of sleep loss. SD vulnerability was computed as the decrease in response speed (∆RS) and increase in lapses (∆lapse) in SD compared with RW.

Dynamic functional connectivity analysis was conducted on rs-fMRI data. Connectivity matrices were clustered to obtain 5 prototypical DCS. We calculated the proportion of time participants spent in each of these DCS, as well as how often participants transitioned between DCSs. Relationships between SD vulnerability and connectivity metrics were then correlated.

Results

We recovered two DCS that were highly similar (ρ = .89-.91) to arousal-related DCS observed in previous work (high arousal state (HAS); low arousal state (LAS)).

After sleep deprivation, the proportion of time spent in the LAS increased significantly (t29=3.16, p=.0039), while there was no significant change in HAS (t29=-1.43, p=.16). We observed significantly more state transitions in RW compared with SD. Change in LAS and HAS across sleep conditions correlated significantly with SD vulnerability (ΔLASxΔRS: r=-0.64, p&lt;.0001; ΔLASxΔlapse: r=0.43, p=.018; ΔHASxΔRS; r=0.43, p=.019; ΔHASxΔlapse; r=-0.39, p=.033). Finally, Δ%transitions was correlated with ΔRS but not Δlapse.

Conclusion

This study adds to the evidence that two specific reproducible DCS are robust markers of arousal and attention, and may be useful indicators of SD vulnerability.

Support

This work was supported by the National Medical Research Council, Singapore (STaR/0015/2013), and the National Research Foundation Science of Learning (NRF2016-SOL002-001).

0092 A Daytime Nap Restores Hippocampal Function and Improves Declarative Learning

Introduction

Daytime naps have been shown to improve learning outcomes. One theory underlying enhanced encoding following a nap is via the synaptic downscaling of neurons potentiated during wake - a process facilitated by slow oscillations. In this study, we sought to investigate neural mechanisms underlying enhanced encoding following a nap compared to a waking period using a combination of PSG and fMRI methods.

Methods

40 healthy undergraduates (M=23.3y, SD=2.96y; 10 males) who slept normally the previous night encoded word pair lists across 2 runs in an MRI scanner at 1PM and 4.30PM. In between encoding sessions, participants either stayed awake and watched a documentary (Wake group; N=20), or napped for 90-min while undergoing polysomnography (Nap group; N=20). Approximately 40min after each encoding session, memory of these word lists were assessed in a cued-recall fashion. Performance in each session was measured by percentage of correct responses.

Results

There were no baseline differences in encoding performance. However, a Session x Group interaction effect (p&lt;0.001) was observed whereby performance significantly improved only in the Nap group in the second encoding session (Nap:20±19% vs. Wake:-1±13%). Concurrent to this, fMRI analyses revealed a Session x Run x Group interaction effect in the hippocampus (p=0.002) whereby hippocampal activation during encoding of the word lists increased only in the Nap group. In addition, although there was no association between degree of performance improvement in the nap group with duration of sleep or the various sleep stages (N1,N2,N3,REM), spindle count (12-15Hz) in the Nap group correlated significantly with both performance improvement (rs=0.46) and increase in hippocampal activation (rs=0.46).

Conclusion

These results confirm the benefit of a nap on encoding processes. Hippocampal activation also increased following the nap, which could indicate renewed hippocampal capacity to store new information. While we hypothesized that slow wave sleep would aid in this transfer, we instead found a relationship between spindle count and both degree of performance improvement and increase in hippocampal activation. The interplay between NREM sleep oscillations, hippocampal downscaling and encoding performance could be more complex than originally thought.

Support

National Medical Research Council, Singapore (NMRC/STaR/015/2013) and the Far East Organization.

0519 Mindfulness Based Therapy for Insomnia Improves Objective Markers of Sleep in the Elderly: Preliminary Data from the Mindfulness Sleep Therapy (MIST) Study

Introduction

Mindfulness-based treatment for insomnia (MBTI) is a viable intervention for improving poor sleep. We report preliminary data from an ongoing pre-registered, randomized controlled trial which investigates the effect of MBTI on elderly adults.

Methods

Participants above 50 years old with PSQI ≥ 5 were recruited and randomised into either MBTI or an active control group (Sleep hygiene education and exercise program, SHEEP) in sequential cohorts with about 20 participants per cohort (10 per group). Before and after the intervention, 1 night of portable polysomnography (PSG) and 1 week of actigraphy (ACT) and sleep diary (DIARY) data were collected. We report the ACT and DIARY results of the first 3 cohorts (n = 46, male = 23, mean age = 62.3, std = 6.3) and PSG data of the first 2 cohorts (n = 29, male = 12, mean age = 62.5, std = 5.7). Time in bed (TIB), total sleep time (TST), sleep onset latency (SOL), wake after sleep onset (WASO), and sleep efficiency (SE) were analysed with mixed-model repeated-measures ANOVA.

Results

We observed increases in TIBDIARY (F1,44 = 5.151, p &lt; .05) and SEDIARY (F1,44 = 22.633, p &lt; .0001), and significant reductions in SOLDIARY (F1,44 = 7.031, p &lt; .05) and WASODIARY (F1,39 = 7.411, p &lt; .05). In the actigraphy data, we found a significant interaction in SOLACT (F1,39 = 4.273, p &lt; .05) with an increase in SHEEP SOLACT (t18= 2.36, p &lt; .05). Significant reductions were also observed in WASOACT (F1,44 = 16.459, p &lt; .0001) Finally, we observed a reduction in SOLPSG (F1,26 = 5.037, p &lt;. 05). All other tests were non-significant.

Conclusion

Preliminary results suggest that both interventions lead to improvements in sleep with more pronounced effects in subjective sleep reports. Objective sleep data suggest that improvements in sleep is a result of improved sleep quality and not simply extending sleep opportunity. These preliminary data shows that MBTI may be a promising intervention for elderly individuals with sleep difficulties.

Support

This study was supported by an award from the 7th grant call of the Singapore Millennium Foundation Research Grant Programme

A 24-month cost and outcome analysis comparing traditional fronto-orbital advancment and remodeling with endoscopic strip craniectomy and molding helmet in the management of unicoronal craniosynostosis: A retrospective bi-institutional review

Introduction

Endoscopic strip craniectomy with helmeting (ESCH) has been shown to be a safe and efficacious alternative to fronto-orbital remodeling (FOR) for selected children with craniosynostosis. In addition to clinical factors, there may be economic benefits from the use of ESCH instead of FOR.

Methods

A retrospective review of 23 patients with nonsyndromic unicoronal craniosynostosis (UCS) treated with FOR was carried out at Great Ormond Street Hospital (GOSH) for Children in London, UK. Secondary data were used for the ESCH cohort from a paper published by Jimenez and Barone (2013). Data were collected on surgical time, transfusion rates, length of hospital stay, adverse event rates, reintervention rates, and overall costs. Costs were categorized and then assigned to the appropriate data sets.

Results

The mean age of patients undergoing FOR (vs. ESCH) was 17.4 mo (vs. 3.1 mo) with a mean surgical time of 234 min (vs. 55 min), mean transfusion volume of 221.6 mL (vs. 80.0 mL), mean transfusion rate of 14/23 (vs. 2/115), and a total immediate overnight stay of 3.13 days (vs. 97% next-day discharge). The FOR group had a higher adverse event rate (5/23 vs. 4/115, p=<0.005) and a higher number requiring extraocular muscle surgery (4/23 vs. 7/109, p=0.16). There was a substantial difference in overall costs between the two groups. Total variance cost for the FOR group was £7436.5 vs. £4951.35, representing a cost difference of £2485.15 over the 24-month study period.

Conclusion

ESCH, in comparison to FOR, appears as a more economical method in the management of USC patients, as well as having clinical benefits including reduced adverse event rate and improved ophthalmic outcomes.

P847 Echocardiographic imaging in primary cardiac tumour-leiomyosarcoma

Funding Acknowledgements

N.A

Primary cardiac tumours are rare entities with an incidence rate of 0.0017% to 0.019% of which 25% are malignant. Leiomyosarcomas, a form of primary cardiac sarcoma, accounts for 8-9% of all the cardiac sarcomas (1). Primary cardiac sarcomas typically present late with either quite advanced local cardiac symptoms or non-specific symptoms arising from metastasis (2). We herein report a rare presentation of leiomyosarcoma in a sixty-seven year old female Caucasian female, originally suspected following transthoracic echocardiogram.

A large mass filling the Left Atrium(L.A) with a degree obstruction to the Mitral Valve (M.V) was firstly noted on transthoracic echocardiogram. This mass had a broad base, appeared to be originating from the pulmonary veins and was not encapsulated. A small circumferential pericardial effusion was noted. Overall biventricular function was preserved and there was no evidence of pulmonary hypertension. A contrast-enhanced computed tomography scan of the chest, abdomen and pelvis was performed for staging which in addition to known cardiac mass revealed widespread bony metastases. A core biopsy of one of the lumbar paravertebral metastatic deposit was carried out to establish the diagnosis.

We hope to add to the pool of increasing overall understanding of primary cardiac sarcomas and share our fascinating echocardiogram findings. In addition, we believe this case supports our recommendation for general practitioners in the United Kingdom to have open access to requesting echocardiograms in order to identify such aggressive cardiac malignancies at an earlier stage, with the hope to improve prognosis.

Abstract P847 Figure. Depicting LA mass occupying the whole of

Marked TGF-β-regulated miRNA expression changes in both COPD and control lung fibroblasts

COPD is associated with disturbed tissue repair, possibly due to TGF-β-regulated miRNA changes in fibroblasts. Our aim was to identify TGF-β-regulated miRNAs and their differential regulation and expression in COPD compared to control fibroblasts. Small RNA sequencing was performed on TGF-β-stimulated and unstimulated lung fibroblasts from 15 COPD patients and 15 controls. Linear regression was used to identify TGF-β-regulated and COPD-associated miRNAs. Interaction analysis was performed to compare miRNAs that responded differently to TGF-β in COPD and control. Re-analysis of previously generated Ago2-IP data and Enrichr were used to identify presence and function of potential target genes in the miRNA-targetome of lung fibroblasts. In total, 46 TGF-β-regulated miRNAs were identified in COPD and 86 in control fibroblasts (FDR < 0.05). MiR-27a-5p was the most significantly upregulated miRNA. MiR-148b-3p, miR-589-5p and miR-376b-3p responded differently to TGF-β in COPD compared to control (FDR < 0.25). MiR-660-5p was significantly upregulated in COPD compared to control (FDR < 0.05). Several predicted targets of miR-27a-5p, miR-148b-3p and miR-660-5p were present in the miRNA-targetome, and were mainly involved in the regulation of gene transcription. In conclusion, altered TGF-β-induced miRNA regulation and differential expression of miR-660-5p in COPD fibroblasts, may represent one of the mechanisms underlying aberrant tissue repair and remodelling in COPD.

Does the gene matter? Genotype-phenotype and genotype-outcome associations in congenital melanocytic naevi

Background

Genotype–phenotype studies can identify subgroups of patients with specific clinical features or differing outcomes, which can help shape management.

Objectives

To characterize the frequency of different causative genotypes in congenital melanocytic naevi (CMN), and to investigate genotype–phenotype and genotype–outcome associations.

Methods

We conducted a large cohort study in which we undertook MC1R genotyping from blood, and high‐sensitivity genotyping of NRAS and BRAF hotspots in 156 naevus biopsies from 134 patients with CMN [male 40%; multiple CMN 76%; projected adult size (PAS) > 20 cm, 59%].

Results

Mosaic NRAS mutations were detected in 68%, mutually exclusive with BRAF mutations in 7%, with double wild‐type in 25%. Two separate naevi were sequenced in five of seven patients with BRAF mutations, confirming clonality. Five of seven patients with BRAF mutations had a dramatic multinodular phenotype, with characteristic histology distinct from classical proliferative nodules. NRAS mutation was the commonest in all sizes of CMN, but was particularly common in naevi with PAS > 60 cm, implying more tolerance to that mutation early in embryogenesis. Facial features were less common in double wild‐type patients. Importantly, the incidence of congenital neurological disease, and apparently of melanoma, was not altered by genotype; no cases of melanoma were seen in BRAF‐mutant multiple CMN, however, this genotype is rare.

Conclusions

CMN of all sizes are most commonly caused by mutations in NRAS. BRAF is confirmed as a much rarer cause of multiple CMN, and appears to be commonly associated with a multinodular phenotype. Genotype in this cohort was not associated with differences in incidence of neurological disease in childhood. However, genotyping should be undertaken in suspected melanoma, for guidance of treatment.

What's already known about this topic?

Multiple congenital melanocytic naevi (CMN) have been shown to be caused by NRAS mosaic mutations in 70–80% of cases, by BRAF mosaicism in one case report and by inference in some previous cases.

There has been debate about genotypic association with different sizes of CMN, and no data on genotype–outcome.

What does this study add?

NRAS mosaicism was found in 68%, BRAF in 7% and double wild‐type in 25% of cases of CMN.

NRAS was the commonest mutation in all sizes of CMN, but was nearly universal in projected adult size > 60 cm.

BRAF is often associated with a distinct multinodular clinical/histological phenotype.

Adverse outcomes did not differ between genotypes on current numbers.

https://doi.org/10.1111/bjd.18747 available online

WPI-13 Lack of association of cranial lacunae with intracranial hypertension in children with crouzon syndrome and apert syndrome: a 3D morphometric quantitative analysis

Objectives

Cranial lacunae on CT is equivalent to the plain X-ray ‘copper beating’ seen in craniosynostosis. Copper beating has not been shown to correlate to intracranial hypertension (IH). However it is a purely quantitative assessment – can qualitative measurement of CT cranial lacunae more accurately predict IH in children with craniosynostosis?

Design

Retrospective cohort study.

Subjects

18 consecutive children with Crouzon and 17 with Apert syndrome were identified.

Methods

Patients were divided into IH and non-IH groups defined on an intention to treat basis. 3D software was used to analyse% of calvarial lacunae.

Results

Mean age at CT scan was 380 days (range 6–1778). Of the 35 children, 21 required surgery for raised ICP (17 posterior vault expansion 2 ventriculo-peritoneal shunts (VPS), 1 spring-assisted cranioplasty and 1 fronto-orbital advancement) at mean age of 512 days (range 38–1710). Of the 21 children with raised ICP, 15 had lacunae with mean lacuna/calvarium percentage of 3% (0%–28%). Of the 14 non-raised ICP children, 8 had lacunae with mean lacuna/calvarium percentage of 2% (0%–8%). T-test demonstrated no significant difference between the 2 groups. For both groups, parietal bones were most likely to show lacunae (IH 14/21, non-IH 9/14), followed by occipital (IH 8/21, non-IH 3/14), followed by frontal (IH 6/21, non-IH 2/14).

Conclusions

Results suggest that cranial lacunae, measured using quantitative 3D methods, do not predict IH, in agreement with evidence from qualitative plain skull radiograph studies.

Factors influencing patient decision-making between simple mastectomy and surgical alternatives

Background

Despite similar survival rates, breast‐conserving therapy (BCT) remains a distant second choice after simple mastectomy for patients with early‐stage breast cancer in Singapore. Uptake of reconstruction after mastectomy is also low (18 per cent). The aim of this study was to explore the factors influencing a patient's choice for mastectomy when eligible for BCT, and why patients decline reconstruction after mastectomy.

Methods

Patients from the National Cancer Centre Singapore, who were eligible for BCT but chose mastectomy without reconstruction, between December 2014 and December 2015 were included. An interviewer‐administered questionnaire focusing on patients' reasons for choosing mastectomy over BCT and not opting for immediate breast reconstruction after mastectomy was used. Tumour characteristics were retrieved from medical records. Spearman's rank correlation coefficient, Mann–Whitney U and Kruskal–Wallis tests were used to analyse the correlation between the patient's self‐rated influential factors and variables. Statistical significance was taken as P < 0·050.

Results

Ninety‐one patients were included (90·1 per cent response rate). The main reasons for choosing mastectomy over BCT were: fear of cancer recurrence (considered very important in 74 per cent), the perception that health outweighs breast retention (49 per cent) and the possibility of second surgery for margins (40 per cent). Key factors for rejecting immediate reconstruction after mastectomy were: patient‐perceived ‘old age’ (very important in 53 per cent), concern about two sites of surgery (42 per cent) and financial cost (29 per cent). Given a second chance, 19·8 per cent of patients would undergo BCT instead of mastectomy.

Conclusion

This study has identified the considerations that women in Singapore have when deciding on breast cancer surgery. Some perceptions need to be addressed for women to make a fully informed decision, especially as one‐fifth regret their initial choice.

A smoking cessation programme for current and recent ex-smokers following diagnosis of a potentially curable cancer

BACKGROUND

Cancer patients who quit smoking have improved survival rates. The time of diagnosis provides a 'teachable moment' when healthcare providers can offer smoking-cessation treatment.

AIMS

To assess the impact on quit rates of a tailored smoking-cessation intervention for patients diagnosed with a potentially curable cancer.

METHODS

A prospective, one-arm cohort study of current smokers and recent quitters (<30 days) who had commenced treatment for a potentially curable cancer was performed. Intervention involved an initial motivational interview, regular follow up and pharmacotherapy when appropriate. Quit rates were measured at 1, 3, 6 and 12 months by self-reported abstinence and biochemical confirmation. The primary end point was prolonged abstinence at 12 months. Changes in quality of life parameters and distress were also assessed.

RESULTS

Seventy-one patients were recruited, with a median age of 56 years. Forty-one patients (58%) had a smoking-related cancer. The prolonged abstinence rate at 12 months was 24% (95% confidence interval 14-36%). Factors associated with successful quitting included being in the preparation or action phase of readiness to change at study entry (P = 0.012) and having complications of treatment requiring hospitalisation (P = 0.024). Between baseline and 12 months, quitters reported improvement in self-control (P < 0.001) and reduced levels of distress (P = 0.03) compared to non-quitters.

CONCLUSION

Patients who continue to smoke after being diagnosed with cancer require intensive support to quit. An individualised behavioural and pharmacological intervention can be successful in helping patients quit smoking, with quality of life improvements seen amongst successful quitters. Population measures to stop people starting smoking remain essential.

Safety, efficacy and pharmacokinetics of rVIII-SingleChain in children with severe hemophilia A: results of a multicenter clinical trial

Essentials rVIII-SingleChain is a novel recombinant factor VIII with covalently bonded heavy and light chains. Efficacy, safety and pharmacokinetics were studied in pediatric patients with severe hemophilia A. Across all prophylaxis regimens, the median annualized spontaneous bleeding rate was 0.00. rVIII-SingleChain showed excellent hemostatic efficacy and a favorable safety profile.

SUMMARY

Background rVIII-SingleChain is a novel B-domain truncated recombinant factor VIII (rFVIII) comprised of covalently bonded FVIII heavy and light chains, demonstrating a high binding affinity to von Willebrand factor. Objectives This phase III study investigated the safety, efficacy and pharmacokinetics of rVIII-SingleChain in previously treated pediatric patients < 12 years of age with severe hemophilia A. Patients/Methods Patients could be assigned to prophylaxis or on-demand therapy by the investigator. For patients assigned to prophylaxis, the treatment regimen and dose were based on the bleeding phenotype. For patients receiving on-demand therapy, dosing was guided by World Federation of Hemophilia recommendations. The primary endpoint was treatment success, defined as a rating of 'excellent' or 'good' on the investigator's clinical assessment of hemostatic efficacy for all treated bleeding events. Results The study enrolled 84 patients (0 to < 6 years, n = 35; ≥ 6 to < 12 years, n = 49); 81 were assigned to prophylaxis and three to an on-demand regimen. Patients accumulated a total of 5239 exposure days (EDs), with 65 participants reaching > 50 EDs. In the 347 bleeds treated and evaluated by the investigator, hemostatic efficacy was rated as excellent or good in 96.3%. The median annualized spontaneous bleeding rate was 0.00 (Q1, Q3: 0.00, 2.20), and the median annualized bleeding rate was 3.69 (Q1, Q3: 0.00, 7.20) across all prophylaxis regimens. No participant developed an inhibitor. Conclusions rVIII-SingleChain is a novel rFVIII molecule showing excellent hemostatic efficacy and a favorable safety profile in a clinical study in children < 12 years of age with severe hemophilia A.

Pharmacokinetics of oxycodone after subcutaneous administration in a critically ill population compared with a healthy cohort

This study aimed to characterise and compare the absorption pharmacokinetics of a single subcutaneous dose of oxycodone in critically ill patients and healthy subjects. Blood samples taken at intervals from two minutes to eight hours after a subcutaneous dose of oxycodone in patients (5 mg) and healthy volunteers (10 mg) were assayed using high performance liquid chromatography. Data were analysed using a non-compartmental approach and presented as mean (SD). Parameters were corrected for dose differences between the groups assuming linear kinetics. Ten patients (eight male, two female) and seven healthy male subjects were included. Maximum venous concentration and area under the concentration curve were approximately two-fold lower in the patient group for an equivalent dose, suggesting either reduced bioavailability or increased clearance: maximum venous concentration 0.14 ± 0.06 vs 0.05 ± 0.02 µg/ml (P <0.0001); area under the concentration curve 19.50 ± 9.15 vs 9.72 ± 2.71 µg/ml/minute (P <0.001) respectively. However, time to maximum venous concentration and mean residence time were not different, suggesting similar absorption rates: time to maximum venous concentration 22.10 ± 18.0 vs 20.50 ± 16.10 minutes (P=0.81); mean residence time 353 ± 191 vs 291 ± 80 minutes (P=0.26). Kinetic parameters were less variable in patients than in volunteers. The patients therefore had reduced exposure to subcutaneous oxycodone. This warrants further model-based analysis and experimentation. Dose regimens for subcutaneous oxycodone developed in healthy volunteers cannot be directly translated to critically ill patients.

Diagnosing the doctors' departure: survey on sources of dissatisfaction among Irish junior doctors

There has been a significant decline in the number of applications for non-consultant hospital doctor (NCHD) posts in Ireland over the last 18 months. We conducted an online, anonymous survey of Irish NCHDs to establish levels of satisfaction, sources of dissatisfaction and the major reasons for junior doctors seeking work abroad. 522 NCHDs took the survey, including 64 (12.3%) currently working outside of the Republic. 219 (45.8%) were slightly dissatisfied and 142 (29.7%) were extremely dissatisfied with practising medicine in Ireland. Major sources of dissatisfaction included the state of the health care system, staffing cover for leave and illness, the dearth of consultant posts and the need to move around Ireland. The most important reason for NCHDs wishing to leave was to seek better training and career opportunities abroad.

Solitary caecal ulcer syndrome: our experience with this benign condition

AIM

Solitary caecal ulcer syndrome is rare. We describe our experience of 10 patients with the condition.

METHOD

A prospectively collected database of patients undergoing colonoscopy or surgery with histology reporting a solitary caecal ulcer was reviewed from 1999 to 2008. Patients with known carcinoma of the colon, cytomegalovirus infection, amoebiasis, inflammatory bowel disease, immunosuppression and history of nonsteroidal anti-inflammatory drug use were excluded.

RESULTS

Ten patients were found to have a solitary caecal ulcer. All were of Chinese ethnicity, of median age 61 years. The most common presenting symptoms were haematochezia and right-sided abdominal pain. Histological findings included ulceration sharing some features of solitary rectal ulcer syndrome, but with differences to suggest a different aetiology.

CONCLUSION

Solitary caecal ulcer syndrome should be included in the differential diagnosis of lower gastrointestinal haemorrhage, right iliac fossa pain or when computed tomography imaging demonstrates caecal wall thickening. The diagnosis can only be made on histopathological examination.

Trans-scleral dye injection during vitreous surgery to identify clinically undetectable retinal breaks causing retinal detachment

BACKGROUND/AIMS

Finding all retinal breaks is a critical step in rhegmatogenous retinal detachment (RRD) surgery in order to prevent persistent/recurrent retinal detachment (RD). We describe a technique of trans-scleral dye injection into the subretinal fluid under the detached retina in the context of recurrent/persistent RD in vitrectomized eyes, in order to determine the location of clinically unidentified (occult) retinal breaks causing RD.

METHODS

Retrospective consecutive single-surgeon case-series analysis of patients presenting with a repeat RRD after having been treated with pars plana vitrectomy (PPV) as the method of primary RRD repair. Trans-scleral injection of subretinal vision blue (TSVB) was used to help identify retinal breaks during repeat vitrectomy.

OUTCOME MEASURES

successful detection of a break; location of breaks; persistent retinal attachment; final visual acuity (VA); complications.

RESULTS

There were 395 cases of RRD during the 3-year period reviewed. TSVB was used for eight instances in seven eyes. All eight instances were repeat RRD. TSVB facilitated occult break detection in 7/8 instances of use. Breaks were at or adjacent to the previous cryo site in three instances. Persistent retinal attachment was achieved in 5/7 cases. Final VA increased in 5/7 cases. There was no evidence of complications as a result of TSVB injection.

CONCLUSIONS

TSVB coupled with indentation to vent a plume of dye through an occult break during vitreous surgery is a relatively simple technique that may facilitate the identification of occult retinal breaks and help achieve anatomical success and functional success.

Does hippotherapy improve balance in persons with multiple sclerosis: a systematic review

AIM

Multiple sclerosis (MS) leads to changes in balance due to the breakdown of a number of neurological processes. Hippotherapy utilizes the movement of the horse to provide sensory feedback and has been used as a therapeutic intervention for different neurological conditions. Little is known about the effects of hippotherapy in MS. The purpose of this study is to systematically review and examine the evidence for hippotherapy as an intervention to improve balance in persons with MS.

METHODS

Major electronic databases were searched for articles relating to hippotherapy, MS and balance. Only full length articles published in peer reviewed journals that were written in English or translated into English were included. Articles were assessed using a modified quality index that was used for descriptive purposes only and did not exclude any study from the review.

RESULTS

All studies examined in this review were either case-control or case-series. Collectively all three studies reported improvements in balance. Pre-test and post-test Berg Balance Scale scores in two studies revealed that primary progressive MS demonstrated the greatest amount of change after hippotherapy compared to other subtypes of MS.

CONCLUSION

Hippotherapy has a positive effect on balance in persons with MS and has an added benefit of enhancing quality of life. The data is limited and further research will lead to a greater knowledge base and has the potential to increase accessibility for hippotherapy to be used as a rehabilitation modality.