Assessing the stability and sporicidal efficacy of oxidising disinfectants

The role of the healthcare environment in the transmission of clinical pathogens is well established. We investigated the chemical stability and sporicidal efficacy of oxidising disinfectant products in the presence of simulated clean and medical dirty conditions. Performance of chlorine-releasing agents (sodium dichloroisocyanurate, chlorine dioxide and hypochlorous acid) was concentration-dependent, with 1000 ppm chlorine showing reduced stability and efficacy in dirty conditions. In contrast peracetic acid product demonstrated stability and consistently achieved efficacy in dirty conditions. These results have implications for clinical practice, as ineffective environmental decontamination may increase the risk of transmission of pathogens that can cause healthcare-associated infections.

Sleep related rhythmic movement disorder: phenotypic characteristics and treatment response in a paediatric cohort

OBJECTIVE

To describe phenotypic, polysomnographic characteristics, impact, and treatment response in children with sleep related rhythmic movement disorder (SR-RMD).

BACKGROUND

There is limited research on SR-RMD. We have developed a systematic clinical evaluation of children with SR-RMD to improve understanding and treatment.

METHODS

A retrospective chart review of 66 children at a UK tertiary hospital. Baseline assessment included validated screening questionnaires to study autism spectrum characteristics, general behaviour and sensory profile. A standardised questionnaire assessed impact on sleep quality and daytime wellbeing of child and family. Polysomnography data were collated.

RESULTS

Children were aged 0.9-16.3 years (78.8% male). 51.5% had a neurodevelopmental disorder, most commonly autism spectrum disorder. High rates of behavioural disturbance and sensory processing differences were reported, not confined to children with neurodevelopmental disorders. Parents reported concerns about risk of injury, loss of sleep and persistence into adulthood. Daytime wellbeing was affected in 72% of children and 75% of other family members. Only 31/48 children demonstrated rhythmic movements during video-polysomnography, occupying on average 6.1% of time in bed. Most clusters occurred in the settling period but also arose from N1, N2 and REM sleep and wake after sleep onset. Melatonin was prescribed to 52 children, all but one were extended-release preparations. 24/27 children with available data were reported to improve with melatonin.

CONCLUSIONS

SR-RMD places a significant burden on child and family wellbeing. Our novel findings of sensory processing differences in this population and parent reported therapeutic response to extended-release melatonin offer potential avenues for future research.

Attitudes and Barriers to Planned Family Building among Professionals and Trainees in Radiation Oncology

PURPOSE/OBJECTIVE(S)

The timing of residency training often coincides with peak biological fertility. However, family building is frequently deferred and may lead to unanticipated infertility. The attitudes and barriers to family planning are not well described among medical professionals and trainees in radiation oncology (RO).

MATERIALS/METHODS

The Society for Women in Radiation Oncology (SWRO) conducted an electronic survey among practicing physicians, physicists, and residents between January and February 2023, using email and social media as recruitment tools. The survey questions queried demographics, family planning, fertility. Frequencies of responses were summarized using descriptive statistics.

RESULTS

On interim analysis, 147 responses were collected; 123 (89.8%) were SWRO members. Gender identities reported were female (136, 93.2%), male (7, 4.8%), nonbinary or gender diverse (2, 1.4%), and transgender female (1, 0.7%). 95 (64.6%) respondents were age 35 or younger. The majority were practicing physicians (72, 49.0%) followed by RO residents (45, 30.6%), medical physicists (17, 11.6%), medical students, (5, 3.4%), and medical physics residents (4, 2.7%). Most respondents agreed that their reproductive timeline had been impacted by medical training (106, 76.3%). Of those who deferred parenthood due to training or career, 40 (36.7%) were dissatisfied with their choice and 33 (30.2%) were satisfied. 129 (92.8%) reported not receiving any information about fertility preservation during training. Only 65 (47.4%) felt they had a mentor with whom they could approach to discuss family planning. Overall, 84 (60.4%) expressed concern about their fertility and 34 (24.5%) had previously undergone fertility testing. 16 (11.5%) completed at least one cycle of elective fertility preservation and 12 (8.6%) were planning to do so. 39 (28.1%) had considered elective fertility preservation but not pursued it, while 65 (46.8%) had not considered it. Among those two groups, the common reported barriers to accessing fertility services were financial burden (n = 28, 28.6%), lack of awareness of available options (n = 12, 12.2%), difficulty accessing fertility services (n = 6, 6.1%), and difficulty finding time during training (n = 4, 4.1%). Insurance coverage for elective fertility preservation was fully or partially covered by insurance for 12 (8.8%), not covered for 53 (38.7%), and 72 (52.6%) were uncertain of their coverage.

CONCLUSION

The study highlights the impact of training on family building plans of medical professionals in RO. Despite high levels of concern about fertility, few respondents received education about fertility options in training and a limited number had access to mentors to discuss this issue. Significant barriers exist to accessing fertility services, including knowledge gaps about insurance coverage, highlighting a need for further exploration of these barriers and advocacy for improved family planning support for those in RO who desire it.

A critical evaluation of physical and manufacturing properties of genuine and counterfeit rotary nickel-titanium endodontic instruments

BACKGROUND

Rotary nickel-titanium (NiTi) instruments are made to exacting standards and are costly to manufacture, and quality control is paramount. Consequently, unauthorized factories make counterfeit instruments that are less expensive and may therefore be attractive to dentists. Little information exists about the metallurgy and manufacturing quality of such instruments. There is the potential for counterfeit instruments to be at higher risk of fracture during treatment, thereby compromising clinical outcomes. The aim of this study was to evaluate physical and manufacturing properties of genuine and counterfeit ProTaper Next™ and Mtwo® rotary NiTi instruments.

METHODS

This study investigated the metallurgical properties, manufacturing quality, microhardness and number of cycles to failure of two commonly used rotary NiTi systems and compared them with counterfeit products purporting to be genuine articles.

RESULTS

Counterfeit instruments were found to be inferior in manufacturing standards and were less resistant to cyclic fatigue when compared to genuine instruments.

CONCLUSIONS

Counterfeit rotary NiTi instruments may be less efficient at preparing root canals and may be at higher risk of fracture during endodontic treatment. Dentists must be aware that, although less expensive, counterfeit instruments may be of dubious manufacturing quality and at higher risk of fracture if used in patients. © 2023 Australian Dental Association.

NBCe1-B/C-knockout mice exhibit an impaired respiratory response and an enhanced renal response to metabolic acidosis

The sodium-bicarbonate cotransporter (NBCe1) has three primary variants: NBCe1-A, -B and -C. NBCe1-A is expressed in renal proximal tubules in the cortical labyrinth, where it is essential for reclaiming filtered bicarbonate, such that NBCe1-A knockout mice are congenitally acidemic. NBCe1-B and -C variants are expressed in chemosensitive regions of the brainstem, while NBCe1-B is also expressed in renal proximal tubules located in the outer medulla. Although mice lacking NBCe1-B/C (KOb/c) exhibit a normal plasma pH at baseline, the distribution of NBCe1-B/C indicates that these variants could play a role in both the rapid respiratory and slower renal responses to metabolic acidosis (MAc). Therefore, in this study we used an integrative physiologic approach to investigate the response of KOb/c mice to MAc. By means of unanesthetized whole-body plethysmography and blood-gas analysis, we demonstrate that the respiratory response to MAc (increase in minute volume, decrease in pCO2) is impaired in KOb/c mice leading to a greater severity of acidemia after 1 day of MAc. Despite this respiratory impairment, the recovery of plasma pH after 3-days of MAc remained intact in KOb/c mice. Using data gathered from mice housed in metabolic cages we demonstrate a greater elevation of renal ammonium excretion and greater downregulation of the ammonia recycling enzyme glutamine synthetase in KOb/c mice on day 2 of MAc, consistent with greater renal acid-excretion. We conclude that KOb/c mice are ultimately able to defend plasma pH during MAc, but that the integrated response is disturbed such that the burden of work shifts from the respiratory system to the kidneys, delaying the recovery of pH.

Validation of a polygenic risk score for Frailty in the Lothian Birth Cohort and English Longitudinal Study of Ageing

Frailty is a complex trait. Twin studies and a high-powered Genome Wide Association Study (GWAS) conducted in the UK Biobank have demonstrated a strong genetic basis of frailty. The present study utilized summary statistics from this GWAS to create and test the predictive power of frailty polygenic risk scores (PRS) in two independent samples - the Lothian Birth Cohort 1936 (LBC1936) and the English Longitudinal Study of Ageing (ELSA) aged 67-84 years. Multiple regression models were built to test the predictive power of frailty PRS at five time points. Frailty PRS significantly predicted frailty at all-time points in LBC1936 and ELSA, explaining 2.1% (β = 0.15, 95%CI, 0.085-0.21) and 1.6% (β = 0.14, 95%CI, 0.10-0.17) of the variance, respectively, at age ~68/~70 years (p < 0.001). This work demonstrates that frailty PRS can predict frailty in two independent cohorts, particularly at early ages (~68/~70). PRS have the potential to be valuable instruments for identifying those at risk for frailty and could be important for controlling for genetic confounders in epidemiological studies.

Comparing gene expression in deep infiltrating endometriosis with adenomyosis uteri: evidence for dysregulation of oncogene pathways

BACKGROUND

The pathogenesis of deep infiltrating endometriosis (DIE) is poorly understood. It is considered a benign disease but has histologic features of malignancy, such as local invasion or gene mutations. Moreover, it is not clear whether its invasive potential is comparable to that of adenomyosis uteri (FA), or whether it has a different biological background. Therefore, the aim of this study was to molecularly characterize the gene expression signatures of both diseases in order to gain insight into the common or different underlying pathomechanisms and to provide clues to pathomechanisms of tumor development based on these diseases.

METHODS

In this study, we analyzed formalin-fixed and paraffin-embedded tissue samples from two independent cohorts. One cohort involved 7 female patients with histologically confirmed FA, the other cohort 19 female patients with histologically confirmed DIE. The epithelium of both entities was microdissected in a laser-guided fashion and RNA was extracted. We analyzed the expression of 770 genes using the nCounter expression assay human PanCancer (Nanostring Technology).

RESULTS

In total, 162 genes were identified to be significantly down-regulated (n = 46) or up-regulated (n = 116) in DIE (for log2-fold changes of < 0.66 or > 1.5 and an adjusted p-value of < 0.05) compared to FA. Gene ontology and KEGG pathway analysis of increased gene expression in DIE compared to FA revealed significant overlap with genes upregulated in the PI3K pathway and focal adhesion signaling pathway as well as other solid cancer pathways. In FA, on the other hand, genes of the RAS pathway showed significant expression compared to DIE.

CONCLUSION

DIE and FA differ significantly at the RNA expression level: in DIE the most expressed genes were those belonging to the PI3K pathway, and in FA those belonging to the RAS pathway.

Corneal dystrophy mutations R125H and R804H disable SLC4A11 by altering the extracellular pH dependence of the intracellular pK that governs H+(OH-) transport

Mutations in the H+(OH-) conductor SLC4A11 result in corneal endothelial dystrophy. In previous studies using mouse Slc4a11, we showed that the pK value that governs the intracellular pH dependence of SLC4A11 (pKi) is influenced by extracellular pH (pHe). We also showed that some mutations result in acidic or alkaline shifts in pKi, indicating that the pH dependence of SLC4A11 is important for physiological function. An R125H mutant, located in the cytosolic amino terminus of SLC4A11, apparently causes a complete loss of function, yet the anion transport inhibitor 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) can partially rescue SLC4A11/R125H activity. In the present study we set out to determine whether the effect of R125H is explained by an extreme shift in pKi. In Xenopus oocytes, we measured SLC4A11-mediated H+(OH-) conductance while monitoring pHi. We find that 1) the human corneal variant SLC4A11-B has a more acidic pKi than mouse Slc4a11, likely due to the presence of an NH2-terminal appendage; 2) pKi for human SLC4A11 is acid-shifted by raising pHe to 10.00; and 3) R125H and R804H mutants mediate substantial H+(OH-) conductances at pHe = 10.00, with pKi shifted into the wild-type range. These data suggest that the defect in each is a shift in pKi at physiological pHe, brought about by a disconnection in the mechanisms by which pHe influences pKi. Using de novo modeling, we show that R125 is located at the cytosolic dimer interface and suggest that this interface is critical for relaying the influence of pHe on the external face of the transmembrane domain to the intracellular, pKi-determining regions.

Safety of day-case paediatric tonsillectomy in England: an analysis of administrative data for the Getting It Right First Time programme

We used the Hospital Episodes Statistics database to investigate unwarranted variation in the rates Trusts discharged children the same day after scheduled tonsillectomy and associations with adverse postoperative outcomes. We included children aged 2-18 years who underwent tonsillectomy between 1 April 2014 and 31 March 2019. We stratified analyses by category of Trust, non-specialist or specialist, defined as without or with paediatric critical care facilities, respectively. We adjusted analyses for age, sex, year of surgery and aspects of presentation and procedure type. Of 101,180 children who underwent tonsillectomy at non-specialist Trusts, 62,926 (62%) were discharged the same day, compared with 24,138/48,755 (50%) at specialist Trusts. The adjusted proportion of children discharged the same day as tonsillectomy ranged from 5% to 100% at non-specialist Trusts and 9% to 88% at specialist Trusts. Same-day discharge was not independently associated with an increased rate of 30-day emergency re-admission at non-specialist Trusts but was associated with a modest rate increase at specialist Trusts; adjusted probability 8.0% vs 7.7%, odds ratio (95%CI) 1.14 (1.05-1.24). Rates of adverse postoperative outcomes were similar for Trusts that discharged >70% children the same day as tonsillectomy compared with Trusts that discharged <50% children the same day, for both non-specialist and specialist Trust categories. We found no consistent evidence that day-case tonsillectomy is associated with poorer outcomes. All Trusts, but particularly specialist centres, should explore reasons for low day-case rates and should aim for rates >70%.

Planned surgery in the COVID-19 pandemic: a prospective cohort study from Nottingham

PURPOSE

Globally planned surgical procedures have been deferred during the current COVID-19 pandemic. The study aimed to report the outcomes of planned urgent and cancer cases during the current pandemic using a multi-disciplinary prioritisation group.

METHODS

A prospective cohort study of patients having urgent or cancer surgery at a NHS Trust from 1st March to 30th April 2020 who had been prioritised by a multi-disciplinary COVID Surgery group. Rates of post-operative PCR positive and suspected COVID-19 infections within 30 days, 30-day mortality and any death related to COVID-19 are reported.

RESULTS

Overall 597 patients underwent surgery with a median age of 65 years (interquartile range (IQR) 54-74 years). Of these, 86.1% (514/597) had a current cancer diagnosis. During the period, 60.8% (363/597) of patients had surgery at the NHS Trust whilst 39.2% (234/597) had surgery at Independent Sector hospitals. The incidence of COVID-19 in the East Midlands was 193.7 per 100,000 population during the study period. In the 30 days following surgery, 1.3% (8/597) of patients tested positive for COVID-19 with all cases at the NHS site. Overall 30-day mortality was 0.7% (4/597). Following a PCR positive COVID-19 diagnosis, mortality was 25.0% (2/8). Including both PCR positive and suspected cases, 3.0% (18/597) developed COVID-19 infection with 1.3% at the independent site compared to 4.1% at the NHS Trust (p=0.047).

CONCLUSIONS

Rates of COVID-19 infection in the post-operative period were low especially in the Independent Sector site. Mortality following a post-operative diagnosis of COVID-19 was high.

335 Planned Surgery in the COVID-19 Pandemic: A Prospective Cohort Study from Nottingham

Introduction

Globally planned surgical procedures were deferred during the current COVID-19 pandemic. We aim to report planned urgent and cancer case outcomes during the pandemic using a multi-disciplinary prioritisation group.

Method

Prospective cohort of patients prioritised by a multi-disciplinary COVID Surgery group undergoing urgent or cancer surgery at a NHS Trust from 1^st March-30^th April 2020. 30-day post-operative rates of PCR positive and suspected COVID-19 infections, 30-day mortality and COVID-19 related deaths are reported.

Results

During the period, 597 patients underwent surgery, median age 65-years (interquartile range 54-74) of which 86% (514/597) had a cancer diagnosis. 61% (362/597) had surgery at the NHS Trust whilst 39% (234/597) had surgery at Independent Sector hospitals. The COVID-19 incidence in the East Midlands was 193.7 per 100,000 population. 30-days following surgery, 1.3% (8/597) tested COVID-19 positive with all cases at the NHS site. 30-day mortality was 0.7% (4/597). Mortality following PCR positive COVID-19 diagnosis was 25% (2/8). Including PCR positive and suspected cases 3.0% (18/597) developed COVID-19 infection, 1.3% at the independent site compared to 4.1% at the NHS Trust (p = 0.047).

Conclusions

Rates of COIVD-19 infection in the post-operative period were low especially in the Independent Sector site. Mortality following a post-operative diagnosis of COVID-19 was high.

Implementation of a fetal ultrasound telemedicine service: women's views and family costs

Background

The complexity of fetal medicine (FM) referrals that can be managed within obstetric units is dependent on the availability of specialist ultrasound expertise. Telemedicine can effectively transfer real-time ultrasound images via video-conferencing. We report the successful introduction of a fetal ultrasound telemedicine service linking a specialist fetal medicine (FM) centre and a remote obstetric unit.

Methods

Over a four-year period from October 2015, all women referred for FM consultation from the obstetric unit were seen via telemedicine, excluding cases where invasive testing, intrauterine therapy or cardiac anomalies were anticipated. The outcomes measured included the indication for FM referral; scan duration and image and sound quality during the consultation. Women’s perceptions of the telemedicine consultation and estimated costs to attend the FM centre were measured by a structured questionnaire completed following the first telemedicine appointment during the Phase 1 of the project.

Results

Overall, 297 women had a telemedicine consultation during Phase 1 (pilot and evaluation) and Phase 2 (embedding and adoption) of the project, which covered a 4 year period 34 women completed questionnaires during the Phase 1 of the study. Travel to the telemedicine consultation took a median (range) time of 20 min (4150), in comparison to an estimated journey of 230 min (120,450) to the FM centre. On average, women would have spent approximately £28 to travel to the FM centre per visit. The overall costs for the woman and her partner/ friend to attend the FM centre was estimated to be £439.

Women were generally satisfied with the service and valued the opportunity to have a FM consultation locally.

Conclusions

We have demonstrated that a fetal ultrasound telemedicine service can be successfully introduced to provide FM ultrasound of sufficient quality to allow fetal diagnosis and specialist consultation with parents. Furthermore, the service is acceptable to parents, has shown a reduction in family costs and journey times.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-020-03532-4.

Toward a uniform pathway in managing incidental lung nodules on computerised tomography [CT] coronary angiography; for a cost effective and safe outcome

Background

National Institute for Health and Care Excellence guidelines (NICE CG95) recommends computed tomography coronary angiography [CTCA] as the first line investigation for all patients with suspected typical or atypical angina irrespective of pre-test probability due to its excellent performance and cost effectiveness. However previous cost effectiveness analyses have not factored in the burden of lung nodules [LN] or extracardiac incidentalomas, which are commonly identified on CTCA.

Purpose

As we increasingly detect LN on CTCA scans, it is prudent that a uniform pathway is followed for surveillance of LN. The British Thoracic Society (BTS) has enabled evidence-based development of an algorithm for the management of LN which defines a cut off LN size of ≥5mm requiring further follow up. We aimed to assess the compliance of LN follow up in our patients according to radiology recommendation on CTCA reports and also to assess how well these recommendations adhere to BTS guidelines.

Method

117 patients who underwent CTCA as the initial diagnostic investigation were retrospectively identified from the rapid access chest pain clinic database. Data was collected during a 1 year period between January - December 2017. Data was analysed to determine whether appropriate surveillance pathway was followed for repeat imaging. According to BTS guidelines, nodules ≥5mm should have a systematic work up for surveillance and hence we have stratified our data based on the nodule size. In case of multiple nodules, the largest nodule size was considered.

Results

Out of 117 patients, 77% patients were female with average age 57.8±9.0 years. 40% patients were found to have incidental LN with an average size of 4.63±1.92mm; 44% had a history of cigarette smoking.

Among patient with nodules, 22 (19%) had CT thorax to assess interval change and interestingly 16 (73%) had persisting LN; whereas in 4 (18%), the LN resolved and only 2 (9%) showed increase in LN size. Repeat CT chest was advised for these 2 patients; 1 was advised to undergo biopsy which eventually ruled out malignancy. 6 patients (5%) from group 1 were recommended for repeat CT despite having LN size &lt;5mm.

In the remaining 25 patients (21%) with LN, 15 (60%) did not have further surveillance imaging even though this was recommended by the reporting radiologist. Of these only 3 (12%) had LN ≥5mm which qualified for surveillance CT.

Conclusion

CTCA frequently detects incidentalomas especially LN which cannot be overlooked and require further imaging irrespective of the primary presentation. Our findings also suggest a discrepancy on surveillance CT recommendation against the current BTS guidelines, with potential significant impact on the overall cost effectiveness of CTCA. A systematic approach to LN surveillance could be best achieved with a multidisciplinary team approach (e.g. referral pathway to nodule MDT) and adherence to a standard guideline.

Lung nodule surveillance following CTCA

Funding Acknowledgement

Type of funding source: None

The potential utility of abbreviated breast MRI (FAST MRI) as a tool for breast cancer screening: a systematic review and meta-analysis

AIM

To synthesise evidence comparing abbreviated breast magnetic resonance imaging (abMRI) to full-protocol MRI (fpMRI) in breast cancer screening.

MATERIALS AND METHODS

A systematic search was undertaken in multiple databases. Cohort studies without enrichment, presenting accuracy data of abMRI in screening, for any level of risk (population, moderate, high risk) were included. Level of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Meta-analyses (bivariate random effects model) were performed for abMRI, with fpMRI and histology from fpMRI-positive cases as reference standard, and with follow-up to symptomatic detection added to the fpMRI. The review also covers evidence comparing abMRI with mammographic techniques.

RESULTS

The title and abstract review retrieved 23 articles. Five studies (six articles) were included (2,763 women, 3,251 screening rounds). GRADE assessment of the evidence was very low because the reference standard was interpreted with knowledge of the index test and biopsy was not obtained for all abMRI positives. The overall sensitivity for abMRI, with fpMRI (and histology for fpMRI positives) as reference standard, was 94.8% (95% confidence interval [CI] 85.5-98.2) and specificity as 94.6% (95% CI: 91.5-96.6). Three studies (1,450 women, 1,613 screening rounds) presented follow-up data, enabling comparison between abMRI and fpMRI. Sensitivities and specificities for abMRI did not differ significantly from those for fpMRI (p=0.83 and p=0.37, respectively).

CONCLUSION

A very low level of evidence suggests abMRI could be accurate for breast cancer screening. Research is required, with follow-up to interval cancer, to determine the effect its use could have on clinical outcome.

pH dependence of the Slc4a11-mediated H+ conductance is influenced by intracellular lysine residues and modified by disease-linked mutations

SLC4A11 is the only member of the SLC4 family that transports protons rather than bicarbonate. SLC4A11 is expressed in corneal endothelial cells, and its mutation causes corneal endothelial dystrophy, although the mechanism of pathogenesis is unknown. We previously demonstrated that the magnitude of the H⁺ conductance (G_m) mediated by SLC4A11 is increased by rises in intracellular as well as extracellular pH (pH_i and pH_e). To better understand this feature and whether it is altered in disease, we studied the pH dependence of wild-type and mutant mouse Slc4a11 expressed in Xenopus oocytes. Using voltage-clamp circuitry in conjunction with a H⁺-selective microelectrode and a microinjector loaded with NaHCO₃, we caused incremental rises in oocyte pH_i and measured the effect on G_m. We find that the rise of G_m has a steeper pH_i dependence at pH_e =8.50 than at pH_e =7.50. Data gathered at pH_e =8.50 can be fit to the Hill equation enabling the calculation of a pK value that reports pH_i dependence. We find that mutation of lysine residues that are close to the first transmembrane span (TM1) causes an alkaline shift in pK. Furthermore, two corneal-dystrophy-causing mutations close to the extracellular end of TM1, E399K and T401K (E368K and T370K in mouse), cause an acidic shift in pK, while a third mutation in the fourth intracellular loop, R804H (R774H in mouse), causes an alkaline shift in pK. This is the first description of determinants of SLC4A11 pH dependence and the first indication that a shift in pH dependence could modify disease expressivity in some cases of corneal dystrophy.

Strategies to Improve Recruitment to a De-escalation Trial: A Mixed-Methods Study of the OPTIMA Prelim Trial in Early Breast Cancer

AIMS

De-escalation trials are challenging and sometimes may fail due to poor recruitment. The OPTIMA Prelim randomised controlled trial (ISRCTN42400492) randomised patients with early stage breast cancer to chemotherapy versus 'test-directed' chemotherapy, with a possible outcome of no chemotherapy, which could confer less treatment relative to routine practice. Despite encountering challenges, OPTIMA Prelim reached its recruitment target ahead of schedule. This study reports the root causes of recruitment challenges and the strategies used to successfully overcome them.

MATERIALS AND METHODS

A mixed-methods recruitment intervention (QuinteT Recruitment Intervention) was used to investigate the recruitment difficulties and feedback findings to inform interventions and optimise ongoing recruitment. Quantitative site-level recruitment data, audio-recorded recruitment appointments (n = 46), qualitative interviews (n = 22) with trialists/recruiting staff (oncologists/nurses) and patient-facing documentation were analysed using descriptive, thematic and conversation analyses. Findings were triangulated to inform a 'plan of action' to optimise recruitment.

RESULTS

Despite best intentions, oncologists' routine practices complicated recruitment. Discomfort about deviating from the usual practice of recommending chemotherapy according to tumour clinicopathological features meant that not all eligible patients were approached. Audio-recorded recruitment appointments revealed how routine practices undermined recruitment. A tendency to justify chemotherapy provision before presenting the randomised controlled trial and subtly indicating that chemotherapy would be more/less beneficial undermined equipoise and made it difficult for patients to engage with OPTIMA Prelim. To tackle these challenges, individual and group recruiter feedback focussed on communication issues and vignettes of eligible patients were discussed to address discomforts around approaching patients. 'Tips' documents concerning structuring discussions and conveying equipoise were disseminated across sites, together with revisions to the Patient Information Sheet.

CONCLUSIONS

This is the first study illuminating the tension between oncologists' routine practices and recruitment to de-escalation trials. Although time and resources are required, these challenges can be addressed through specific feedback and training as the trial is underway.

Evaluation of oats with varying hull inclusion in broiler diets up to 35 days

Use of local feed ingredients in poultry feed, such as oats, can be limited by their perceived less than ideal nutritional content. Dehulling oats is expensive, and it may be that removing hull is detrimental to the bird in terms of gastrointestinal (GI) development, therefore maintaining some of the high-fiber oat hull (OH) might reduce costs and improve potential for inclusion in poultry diets.

Male broilers were fed diets with oats replacing 30% of wheat in diets, either dehulled or with graded inclusions of OH from day of hatch until day 35. Each diet was fed to 8 pens of 8 birds and performance recorded weekly. Samples were collected at day 21 and 35 for analysis of ileal amino acid digestibility, apparent metabolizable energy (AME), and gross gut development measures.

No detrimental effect was seen on bird weight with hull inclusion, though higher inclusion levels did deleteriously effect feed intake because of increased gut fill from the fiber. Nitrogen corrected AME was also adversely effected in the highest hull inclusion diets. However, amino acid digestibility was improved with hull addition, which may be because of an increase in GI tract length, improving nutrient absorption. Gizzard development was also significantly improved, and thereby, more efficient grinding of diet may also have improved digestibility. At a lower level of hull inclusion (3% total diet) where digestibility is improved without any detrimental effects on gut fill and intake.

Oat hull is well known to improve gut development, especially of the gizzard, with resultant increases in digestibility. This is usually attributed to the mechanical effect of fiber in the gizzard having a grinding effect. However in this study, all fiber was finely ground, so the improvements seen cannot be attributed to a physical cause. Oat including diets with some hull remaining are a cost effective way of using oats as a raw material while maximizing bird performance.

Adjuvant bevacizumab for melanoma patients at high risk of recurrence: survival analysis of the AVAST-M trial

Background

Bevacizumab is a recombinant humanised monoclonal antibody to vascular endothelial growth factor shown to improve survival in advanced solid cancers. We evaluated the role of adjuvant bevacizumab in melanoma patients at high risk of recurrence.

Patients and methods

Patients with resected AJCC stage IIB, IIC and III cutaneous melanoma were randomised to receive either adjuvant bevacizumab (7.5 mg/kg i.v. 3 weekly for 1 year) or standard observation. The primary end point was detection of an 8% difference in 5-year overall survival (OS) rate; secondary end points included disease-free interval (DFI) and distant metastasis-free interval (DMFI). Tumour and blood were analysed for prognostic and predictive markers.

Results

Patients (n=1343) recruited between 2007 and 2012 were predominantly stage III (73%), with median age 56 years (range 18–88 years). With 6.4-year median follow-up, 515 (38%) patients had died [254 (38%) bevacizumab; 261 (39%) observation]; 707 (53%) patients had disease recurrence [336 (50%) bevacizumab, 371 (55%) observation]. OS at 5 years was 64% for both groups [hazard ratio (HR) 0.98; 95% confidence interval (CI) 0.82–1.16, P = 0.78). At 5 years, 51% were disease free on bevacizumab versus 45% on observation (HR 0.85; 95% CI 0.74–0.99, P = 0.03), 58% were distant metastasis free on bevacizumab versus 54% on observation (HR 0.91; 95% CI 0.78–1.07, P = 0.25). Forty four percent of 682 melanomas assessed had a BRAF^V600 mutation. In the observation arm, BRAF mutant patients had a trend towards poorer OS compared with BRAF wild-type patients (P = 0.06). BRAF mutation positivity trended towards better OS with bevacizumab (P = 0.21).

Conclusions

Adjuvant bevacizumab after resection of high-risk melanoma improves DFI, but not OS. BRAF mutation status may predict for poorer OS untreated and potential benefit from bevacizumab.

Clinical Trial Information

ISRCTN 81261306; EudraCT Number: 2006-005505-64

Latent autoimmune diabetes of adulthood (LADA) is associated with small fibre neuropathy

AIM

To assess if latent autoimmune diabetes of adulthood (LADA) is associated with small fibre neuropathy.

METHODS

Participants with LADA (n=31), Type 2 diabetes (n=31) and healthy control participants without diabetes (n=31) underwent a detailed assessment of neurologic deficits, quantitative sensory testing, electrophysiology, skin biopsy and corneal confocal microscopy.

RESULTS

The groups were matched for age (healthy control without diabetes: 53.5±9.1 vs. Type 2 diabetes: 58.0±6.5 vs. LADA: 53.2±11.6 years), duration of diabetes (Type 2 diabetes: 10.0±8.3 vs. LADA: 11.0±9.1 years) and blood pressure. However, BMI (P=0.01) and triglycerides (P=0.0008) were lower and HbA_1c (P=0.0005), total cholesterol (P=0.01) and HDL (P=0.002) were higher in participants with LADA compared with Type 2 diabetes. Peroneal motor nerve conduction velocity (P=0.04) and sural sensory nerve conduction velocity (P=0.008) were lower in participants with latent autoimmune diabetes in adults compared with Type 2 diabetes. Intra-epidermal nerve fibre density (P=0.008), corneal nerve fibre density (P=0.003) and corneal nerve branch density (P=0.006) were significantly lower in participants with LADA compared with Type 2 diabetes. There were no significant differences in the other neuropathy parameters.

CONCLUSIONS

Despite comparable age and duration of diabetes, participants with LADA demonstrate more severe neuropathy and particularly small fibre neuropathy, compared with participants with Type 2 diabetes.

Extrarenal Signs of Proximal Renal Tubular Acidosis Persist in Nonacidemic Nbce1b/c-Null Mice

BACKGROUND

The SLC4A4 gene encodes electrogenic sodium bicarbonate cotransporter 1 (NBCe1). Inheritance of recessive mutations in SLC4A4 causes proximal renal tubular acidosis (pRTA), a disease characterized by metabolic acidosis, growth retardation, ocular abnormalities, and often dental abnormalities. Mouse models of pRTA exhibit acidemia, corneal edema, weak dental enamel, impacted colons, nutritional defects, and a general failure to thrive, rarely surviving beyond weaning. Alkali therapy remains the preferred treatment for pRTA, but it is unclear which nonrenal signs are secondary to acidemia and which are a direct consequence of NBCe1 loss from nonrenal sites (such as the eye and enamel organ) and therefore require separate therapy. SLC4A4 encodes three major NBCe1 variants: NBCe1-A, NBCe1-B, and NBCe1-C. NBCe1-A is expressed in proximal tubule epithelia; its dysfunction causes the plasma bicarbonate insufficiency that underlies acidemia. NBCe1-B and NBCe1-C exhibit a broad extra-proximal-tubular distribution.

METHODS

To explore the consequences of Nbce1b/c loss in the absence of acidemia, we engineered a novel strain of Nbce1b/c-null mice and assessed them for signs of pRTA.

RESULTS

Nbce1b/c-null mice have normal blood pH, but exhibit increased mortality, growth retardation, corneal edema, and tooth enamel defects.

CONCLUSIONS

The correction of pRTA-related acidemia should not be considered a panacea for all signs of pRTA. The phenotype of Nbce1b/c-null mice highlights the physiologic importance of NBCe1 variants expressed beyond the proximal tubular epithelia and potential limitations of pH correction by alkali therapy in pRTA. It also suggests a novel genetic locus for corneal dystrophy and enamel hypomineralization without acidemia.

Abstract OT1-05-02: OPTIMA: A prospective randomized trial to validate the clinical utility and cost-effectiveness of gene expression test-directed chemotherapy decisions in high clinical risk early breast cancer

Background:Multi-parameter tumour gene expression assays (MPAs) are widely used to estimate individual patient residual risk and to guide chemotherapy use in hormone-sensitive, HER2-negative early breast cancer. The TAILORx trial supports MPA use in a node-negative population. Evidence for MPA use in node-positive breast cancer is limited. OPTIMA (Optimal Personalised Treatment of early breast cancer usIng Multi-parameter Analysis) (ISRCTN42400492) aims to validate MPAs as predictors of chemotherapy sensitivity in a largely node-positive breast cancer population where prospective RCT (Randomised Controlled Trial) evidence is lacking.

Methods: OPTIMA is a partially blinded multi-center RCT with an adaptive two-stage design. The main eligibility criteria are women and men age 40 or older with resected ER-positive, HER2-negative invasive breast cancer and up to 9 involved axillary lymph nodes. Randomisation is to standard management (chemotherapy and endocrine therapy) or to MPA-directed treatment using the Prosigna (PAM50) test. Those with a Prosigna tumour score (ROR_PT) &gt;60 receive standard management whilst those with a low score (≤60) are treated with endocrine therapy alone. Endocrine therapy for pre-menopausal women includes ovarian suppression. The co-primary outcomes are (1) Invasive Disease Free Survival (IDFS) and (2) cost-effectiveness of test-directed treatment. Secondary outcomes include IDFS in patients with low-score tumours and quality of life. An integrated qualitative recruitment study addresses challenges to consent and recruitment and will build on experience from the feasibility study that a multidisciplinary approach at sites is important for recruitment success. Tumour blocks will be banked to allow evaluation of additional MPA technologies. Recruitment of 4500 patients over 5 years will permit demonstration of 3% non-inferiority of test-directed treatment, assuming 5-year IDFS of 85% with standard management, equivalent to a HR of 1.22. Inclusion of patients from the feasibility study will increase the power to test for non-inferiority.

Results: The OPTIMA main trial opened in January 2017. Overall recruitment (including the feasibility study) will reach 1000 in August 2018. Recruitment in Norway will commence in July 2018. Characteristics of the OPTIMA main participants recruited to 31st May 2018 are shown in the table.

Main study patient characteristicsCharacteristic %Median age in years (range)57 (40-80) Menopause statusPre34 Post66 Male1Tumour size&lt;30mm58 &gt;=30mm42Node statuspN04 pN1mi(sn)7 pN1(sn)20 pN155 pN214Historic grade16 258 336

Conclusion: OPTIMA is one of two large scale prospective trials validating the use of test-guided chemotherapy decisions in node-positive early breast cancer. It is expected to have a global impact on breast cancer treatment. Experience from the preliminary study and close engagement with centres will aid trial success.

Funding: OPTIMA is funded by the UK NIHR HTA Programme (10/34/501). Views expressed are those of the authors and not those of the HTA Programme, NIHR, NHS or the DoH.

Citation Format: Stein RC, Hughes-Davies L, Makris A, Macpherson IR, Conefrey C, Rooshenas L, Pinder SE, Thomas J, Hall PS, Cameron DA, Earl HM, Naume B, Poole CJ, Rea DW, MacIntosh SA, Harmer V, Morgan A, Hulme C, McCabe C, Stallard N, Higgins H, Donovan JL, Bartlett JM, Marshall A, Dunn JA. OPTIMA: A prospective randomized trial to validate the clinical utility and cost-effectiveness of gene expression test-directed chemotherapy decisions in high clinical risk early breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-05-02.

Nitrogen and fatty acid rumen metabolism in cattle offered high or low polyphenol oxidase red clover silage

Polyphenol oxidase (PPO) in red clover (RC) has been shown to reduce both lipolysis and proteolysis in silo and implicated (in vitro) in the rumen. However, all in vivo comparisons have compared RC with other forages, typically with lower levels of PPO, which brings in other confounding factors as to the cause for the greater protection of dietary nitrogen (N) and C18 polyunsaturated fatty acids (PUFA) on RC silage. This study compared two RC silages which when ensiled had contrasting PPO activities (RC+ and RC-) against a control of perennial ryegrass silage (PRG) to ascertain the effect of PPO activity on dietary N digestibility and PUFA biohydrogenation. Two studies were performed the first to investigate rumen and duodenal flow with six Hereford×Friesian steers, prepared with rumen and duodenal cannulae, and the second investigating whole tract N balance using six Holstein-Friesian non-lactating dairy cows. All diets were offered at a restricted level based on animal live weight with each experiment consisting of two 3×3 Latin squares using big bale silages ensiled in 2010 and 2011, respectively. For the first experiment digesta flow at the duodenum was estimated using a dual-phase marker system with ytterbium acetate and chromium ethylenediaminetetraacetic acid as particulate and liquid phase markers, respectively. Total N intake was higher on the RC silages in both experiments and higher on RC- than RC+. Rumen ammonia-N reflected intake with ammonia-N per unit of N intake lower on RC+ than RC-. Microbial N duodenal flow was comparable across all silage diets with non-microbial N higher on RC than the PRG with no difference between RC+ and RC-, even when reported on a N intake basis. C18 PUFA biohydrogenation was lower on RC silage diets than PRG but with no difference between RC+ and RC-. The N balance trial showed a greater retention of N on RC+ over RC-; however, this response is likely related to the difference in N intake over any PPO driven protection. The lack of difference between RC silages, despite contrasting levels of PPO, may reflect a similar level of protein-bound-phenol complexing determined in each RC silage. Previously this complexing has been associated with PPOs protection mechanism; however, this study has shown that protection is not related to total PPO activity.

Time-resolved measurements of fast electron recirculation for relativistically intense femtosecond scale laser-plasma interactions

A key issue in realising the development of a number of applications of high-intensity lasers is the dynamics of the fast electrons produced and how to diagnose them. We report on measurements of fast electron transport in aluminium targets in the ultra-intense, short-pulse (<50 fs) regime using a high resolution temporally and spatially resolved optical probe. The measurements show a rapidly (≈0.5c) expanding region of Ohmic heating at the rear of the target, driven by lateral transport of the fast electron population inside the target. Simulations demonstrate that a broad angular distribution of fast electrons on the order of 60° is required, in conjunction with extensive recirculation of the electron population, in order to drive such lateral transport. These results provide fundamental new insight into fast electron dynamics driven by ultra-short laser pulses, which is an important regime for the development of laser-based radiation and particle sources.

Abstract OT1-06-01: OPTIMA: A prospective randomized trial to validate the predictive utility and cost-effectiveness of gene expression test-directed chemotherapy decisions in early breast cancer

Background: Multi-parameter gene expression assays (MPAs) are widely used to estimate individual patient residual risk in hormone-sensitive HER2-negative node-negative early breast cancer, allowing patients with low risk to safely avoid chemotherapy. Evidence for MPA use in node-positive breast cancer is limited. OPTIMA (Optimal Personalised Treatment of early breast cancer usIng Multi-parameter Analysis) aims to validate MPA's as predictors of chemotherapy sensitivity in a largely node-positive breast cancer population.

Methods: OPTIMA is a partially blinded multi-center, phase 3 randomized controlled trial with an adaptive two-stage design. The main eligibility criteria are women or men aged 40 or older with resected ER-positive, HER2-negative breast cancer and up to 9 involved axillary lymph nodes. Randomization is to standard management (chemotherapy and endocrine therapy) or to MPA-directed treatment. Those with a “high risk” tumor MPA score receive standard management whilst those at “low risk” are treated with endocrine therapy alone. The preliminary phase (OPTIMA prelim) evaluated the performance of several MPAs to select a test to be used in the main efficacy trial based on economic analysis, and assessed the feasibility and acceptability of a large UK trial. OPTIMA prelim used Oncotype DX as the primary discriminator; the main trial will use Prosigna (PAM50) with Prosigna Score ≤60 defined as “low-risk”. The co-primary outcomes are (1) Invasive Disease Free Survival (IDFS) and (2) cost-effectiveness of test-directed therapy. Secondary outcomes include IDFS in “low-risk” patients, quality of life and additional survival measures. An integrated qualitative recruitment study will identify and address challenges to recruitment and informed consent. Tumor blocks from all consenting participants will be banked allowing the performance of alternative MPA technologies to be evaluated. Recruitment of 4500 patients will permit demonstration of 3% non-inferiority of test-directed treatment, with 5% significance and 85% power, assuming 3 years follow-up and a control arm 5-year IDFS of at least 85%. The addition of patients from OPTIMA prelim will allow non-inferiority to be assessed with 2.5% significance.

Results: OPTIMA-prelim recruited 412 patients in 23 months from 35 sites with a 47% acceptance rate. The main study opened in January 2017. Early progress indicates that the recruitment target is achievable in the intended 46-month timescale through the participation of &gt;100 sites

Conclusion: OPTIMA, as one of two large scale prospective trials validating the use of test-guided chemotherapy decisions in node-positive early breast cancer, is expected to have a global impact on breast cancer treatment. Experience from OPTIMA prelim showed that patient advocate support and close engagement with sites will aid trial success.

Funding: The project is funded in the UK by the NIHR HTA Programme (10/34/501). Views expressed are those of the authors and not those of the HTA Programme, NIHR, NHS or the DoH.

Citation Format: Stein RC, Makris A, Hughes-Davies L, Macpherson IR, Hall PS, Cameron DA, Earl HM, Pinder SE, Poole CJ, Rea DW, McIntosh S, Harmer V, Morgan A, Rooshenas L, Conefrey C, Donovan JL, Hulme C, McCabe C, Stallard N, Campbell A, Higgins H, Bartlett JMS, Marshall A, Dunn JA. OPTIMA: A prospective randomized trial to validate the predictive utility and cost-effectiveness of gene expression test-directed chemotherapy decisions in early breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-06-01.

The role of disease-linked residue glutamine-913 in support of the structure and function of the human electrogenic sodium/bicarbonate cotransporter NBCe1-A

Mutations in the sodium bicarbonate cotransporter NBCe1 (SLC4A4) cause proximal renal tubular acidosis (pRTA). We recently described a novel pRTA mutation p.Gln913Arg (Q913R), inherited in compound heterozygous form with p.Arg510His (R510H). Q913R causes intracellular retention of NBCe1 and a 'gain of function' Cl- leak. To learn more about the importance of glutamine at position 913, we substituted a variety of alternative amino-acid residues (Cys, Glu, Lys, Leu, Ser) at position 913. Studying cRNA-injected Xenopus oocytes by voltage clamp, we find that most de novo mutants exhibit close-to-normal NBCe1 activity; only Q913K expresses a Cl- leak. Studying transiently-transfected, polarised kidney cells by fluorescence microscopy we find that most de novo mutants (except Q913E) are intracellularly retained. A 3D homology model predicts that Gln913 is located in the gating domain of NBCe1 and neighbours the 3D space occupied by another pRTA-associated residue (Arg881), highlighting an important and conformationally-sensitive region of NBCe1. We conclude that the intracellular retention of Q913R is caused by the loss of Gln at position 913, but that the manifestation of the Cl- leak is related to the introduction of Arg at position 913. Our findings will inform future studies to elucidate the nature and the consequences of the leak.

P544The importance of contractile reserve when assessing asymptomatic patients with aortic stenosis

Asymptomatic patients may exhibit symptoms during objective exercise testing, but whether symptoms are due to the obstructively of the valve (typified by the mean gradient) or underlying ventricular function remains unknown. While the mean gradient is an easy parameter to measure no consensus about the measurement of contractile reserve exists. Longitudinal abnormalities may occur in the presence of a normal ejection fraction and the augmentation of these parameters is poorly described. To obtain an objective regarding patients exercise ability is best determined using cardiopulmonary exercise testing. We therefore examined echocardiographic predictors of exercise ability during cardiopulmonary exercise testing.24 asymptomatic patients with moderate to severe or severe aortic stenosis and preserved ejection fraction underwent stress echocardiography with simultaneous cardiopulmonary exercise testing. The primary assessment of exercise ability was the VO2peak and OUES. Echocardiography was measured at rest and during maximal exercise (defined as RER > 1)OUES and VO2peak showed a poor relationship with conventional parameters of severity including peak and mean gradients, AVA and dimensionless index, resting systolic function (by EF and TDI). During exercise systolic augmentation had a good relationship with exercise ability but the exercise mean gradient and exercise LVEF did not.Longitudinal systolic function and particularly systolic augmentation is the strongest predictor of exercise ability when compared to conventional measures of severity.VO2peakOUESS' exerciseRho=0.69 (p=0.001)R= 0.71 (p=0.001)S' restRho=0.52 (p=0.01)R= 0.44 (p=ns)Rest AV max VRho= 0.09 (p=ns)R= -0.08 (p=ns)Rest AV mean PGRho= 0.34 (p=ns)R=-0.10 (p=ns)Exercise AV max VRho=0.43 (p=0.05)R=0.23 (p=ns)Exercise AVmean PGRho= 0.51 (p=0.001)R=0.26 (p=ns)Rest AVARho=0.40 (p=ns)Rho=0.46 (p=0.04)Dimensionless indexRho=0.15 (p=ns)R=0.13 (p=ns)LVEF restRho=-0.18 (p=ns)R=-0.32 (p=ns)LVEF exerciseRho=0.18 (p=ns)R=0.17 (p=ns)S' - systolic velocity; V - velocity; AV - aortic valve; AVA- aortic valve area; LVEF - left ventricular ejection fraction.

Circulating tumor DNA predicts survival in patients with resected high-risk stage II/III melanoma

Background

Patients with high-risk stage II/III resected melanoma commonly develop distant metastases. At present, we cannot differentiate between patients who will recur or those who are cured by surgery. We investigated if circulating tumor DNA (ctDNA) can predict relapse and survival in patients with resected melanoma.

Patients and methods

We carried out droplet digital polymerase chain reaction to detect BRAF and NRAS mutations in plasma taken after surgery from 161 stage II/III high-risk melanoma patients enrolled in the AVAST-M adjuvant trial.

Results

Mutant BRAF or NRAS ctDNA was detected (≥1 copy of mutant ctDNA) in 15/132 (11%) BRAF mutant patient samples and 4/29 (14%) NRAS mutant patient samples. Patients with detectable ctDNA had a decreased disease-free interval [DFI; hazard ratio (HR) 3.12; 95% confidence interval (CI) 1.79-5.47; P < 0.0001] and distant metastasis-free interval (DMFI; HR 3.22; 95% CI 1.80-5.79; P < 0.0001) versus those with undetectable ctDNA. Detectable ctDNA remained a significant predictor after adjustment for performance status and disease stage (DFI: HR 3.26, 95% CI 1.83-5.83, P < 0.0001; DMFI: HR 3.45, 95% CI 1.88-6.34, P < 0.0001). Five-year overall survival rate for patients with detectable ctDNA was 33% (95% CI 14%-55%) versus 65% (95% CI 56%-72%) for those with undetectable ctDNA. Overall survival was significantly worse for patients with detectable ctDNA (HR 2.63; 95% CI 1.40-4.96); P = 0.003) and remained significant after adjustment for performance status (HR 2.50, 95% CI 1.32-4.74, P = 0.005).

Conclusion

ctDNA predicts for relapse and survival in high-risk resected melanoma and could aid selection of patients for adjuvant therapy.

Clinical trial number

ISRCTN 81261306.